UDK:54+66+502/504 ISSN 2232-755X GLASNIK HEMIČARA, TEHNOLOGA I EKOLOGA REPUBLIKE SRPSKE -Vanredno izdanje- BANJALUKA BOSNA I HERCEGOVINA NOVEMBAR, 2013. Glasnik hem. teh. i ek. RS GHTERS 2013 UDK:54+66+502/504 ISSN 2232-755X GLASNIK HEMIČARA, TEHNOLOGA I EKOLOGA REPUBLIKE SRPSKE -Vanredno izdanje- BANJALUKA BOSNA I HERCEGOVINA NOVEMBAR, 2013. Glasnik hem. teh. i ek. RS GHTERS 2013 Glasnik hemičara, tehnologa i ekologa Republike Srpske Gazette of Chemists, Technologists and Environmentalists of Republic of Srpska Izdavač- Publisher Tehnološki fakultet, Univerzitet u Banjaluci Faculty of Technology, University of Banjaluka Za izdavača – For Publisher Prof.dr Miloš Sorak – Dekan (Dean) Glavni i odgovorni urednik - Editor-in-Chief Prof.dr Ljiljana Vukić, Sekretar – Secretary Jovanka Todiić Lektor engleskog jezika - Copy editor for English Sanja Josifović-Elezović MeĎunarodni ureĎivački odbor – International Editorial Board Prof.dr Slavko Mentus, Univerzitet u Beogradu, Fakultet za fizičku hemiju, Beograd, Srbija, Prof.dr Sonja Đilas, Univerzitet u Novom Sadu, Tehnološki fakultet, Novi Sad, Srbija, Prof.dr Milan Matavulj, Univerzitet u Novom Sadu, Prirodno-matematički fakultet, Novi Sad, Srbija, Prof.dr Miodrag Lazić, Univerzitet u Nišu, Tehnološki fakultet, Leskovac, Srbija, Prof.dr Branko Bugarski, Univerzitet u Beogradu, Tehnološko-metalurški fakultet, Beograd, Srbija, Doc.dr Tatjana Rijavec, Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Ljubljana, Slovenia, Doc.dr Simona Jevšnik, Univerza v Ljubljani, Akademija za dizajn, Ljubljana, Slovenia, Prof.dr Todor Vasiljević, Victoria University, School of Biomedical and Health Sciences, Melburn, Australia. UreĎivački odbor iz BiH - Editorial Board from B&H Dr Branko Škundrić, akademik, Prof.dr Jasminka Sadadinović, Prof.dr Midhat Jašić, Prof.dr Miloš Sorak, Prof.dr Jelena Penavin-Škundrić, Prof.dr Nedeljko Čegar, Prof.dr Mihajlo Ristić, Prof.dr Miloš Šolaja, Prof.dr Miroslav Grubačić, Prof.dr Radana ĐuĎić, Prof.dr Zora Popović, Prof.dr Milorad Maksimović, Prof.dr Dušanka Stojanović, Prof.dr Asima Davidović, Prof.dr Zoran Kukrić, Prof.dr Slavica Grujić, Prof.dr Slavica Sladojević, Prof.dr Ljiljana Topalić-Trivunović, Doc.dr Snjeţana Mandić, Doc.dr Svjetlana Janjić, Kompjuterska priprema – Computer preparing Mr Saša Papuga Tiraţ - Copy 200 primjeraka Adresa redakcije – Address of Editorial Office Tehnološki fakultet Ul.Vojvode Stepe Stepanovića 73 78 000 Banjaluka e-mail. glasnik@tfbl.org http://glasnik.tfbl.org This special edition has been published on the occasion of the 50th anniversary of the Faculty of Technology in Banja Luka. It is dedicated to the 10th Symposium of chemists, technologists and environmentalists of Republic of Srpska. It includes plenary lectures and panel sessions lectures. Editorial Board Ovaj broj časopisa je objavljen povodom 50 godina od osnivanja Tehnološkog fakulteta u Banjoj Luci. Posvećen je X Savjetovanju hemičara, tehnologa i ekologa Republike Srpske i sadrţi plenarna i sekcijska predavanja Redakcija SADRŢAJ TABLE OF CONTENTS Slavko Mentus: CONTEMPORARY RESEARCH OF LITHIUM BATTERIES САВРЕМЕНА ИСПИТИВАЊА ЛИТИЈУМСКИХ БАТЕРИЈА 1 Baltić Ţ. Milan, Đurić Jelena, Mandić Snjeţana, Pećanac Biljana, Lončina Jasna: CONSUMERS AND FOOD SAFETY POTROŠAČI I BEZBEDNOST HRANE 11 Miroslav Gojo, Tomislav Cigula: CHEMICAL PROCESSES IN PRINTING TECHNOLOGY KEMIJSKI PROCESI U GRAFIČKOJ TEHNOLOGIJI 19 Elvis Ahmetović , Nidret Ibrić, Zdravko Kravanja: SUSTAINABLE WATER, WASTEWATER, AND ENERGY MANAGEMENT IN THE PROCESS INDUSTRIES 25 ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Bjørg Egelandsdal, Milena Bjelanovic, Mamta Khatri and Erik Slinde RECENT ACHIEVEMENTS IN MEAT COLOR 37 NOVIJA ISTRAŢIVANJA O BOJI MESA Jelka Geršak: CLOTHING DESIGN AND FIT COMFORT BASED ON BODY MOTION 43 Драгољуб Новаковић, Игор Карловић: САВРЕМЕНИ ТРЕНДОВИ ГРАФИЧКИХ ТЕХНОЛОГИЈА MODERN TRENDS IN GRAPHIC TECHNOLOGIES 51 PLENARY LECTURES PLENARNA PREDAVANJA Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 1-9, -Vanredno izdanje- CONTEMPORARY RESEARCH OF LITHIUM BATTERIES Slavko Mentus University of Belgrade, Faculty of Physical Chemistry, Studentski trg 12, 11185 Belgrade, Serbia e-mail : slavko@ffh.bg.ac.rs ISSN 2232-755X DOI: 10.7251/GHTE13VI001M UDC 621.352.035.211 Since ~90ties the expectaions arose that batteries may replace fossil fuels as main energy suppliers in automobiles. The classic lead-acid and nickel-cadmium batteries would be unsuitable for such purposes due to their own mass (low specific energy) and toxicity. Up to 2010th the solution was sought in hydrogen energetics, but in the last several years the attention was paid to lithium power sources. Initially, the technological solutions taken from the Li-ion cells for mobile phones were considered, with LiCx as anode and LiNiO2 or LiCoO2 as cathode materials, however, today primarily LiFePO4 – based materials are considered, thanks to its lower price and environmental friendliness. In this contribution the overview of characteristics of both classic and contemporary batteries is done. This overview illustrates how the introduction of Li-ion batteries together with recent nanotechnologies provided considerable progress in specific energy, and offered the perspective of battery powered cars. Key words: classical batteries, electrode materials, lithium-ion batteries, specific energy 1. INTRODUCTION TO BATTERIES; THEORETICAL VERSUS PRACTICAL CAPACITY AND ENERGY Batteries are devices composed of two metal conductors –electrodes- dipped into ionic conductor –electrolyte, enabling the oxidation reaction on the one (anode), and accompanying reduction reaction on the other (cathode) metal/electrolyte boundary. The electrons deliberated on anode travel through the load to the cathode where they are consumed, while the movement of ions through electrolyte closes the circular flow of the electricity. The sum of oxidation and reduction reactions presents the chemical reaction of a battery. Fig 1. Battery cell on discharge Fig 2. The cross section of a rechargeable battery for automobile purposes: the pockets of electrode materials packed within plate-like current collectors, dipped in common electrolyte solution, in a common plastic container. The running force of a battery is the tendency of the chemical reaction to proceed spontaneously, which may be quantitatively expressed as a change in Gibbs free energy (G). It is simultaneously equal to a maximal electric work released. Per one mole of reactants it amounts to: -G = nF where nF is the charge deliberated by one mole of electrode materials (nF = n 96500 C, n is the change in oxidation number of reactants, F= 96500 C mol-1, Faraday constant If discharged battery may be charged to its initial state by help of an outer power supply, it is called rechargeable or secondary battery. In opposite case, one deals with a primary battery (for single use only). Among various characteristics significant for practical use, capacity and energy are of primary significance. 1 S. Mentus: CONTEMPORARY RESEARCH OF LITHIUM BATTERIES Capacity is the amount of electricity available when the battery is completely charged. It may be derived from molar capacity of either cathode or anode materijal: QM = nNAe = nF = n·96500 C = n·96500 As = n·96500/3600 Ah = n·26.8 Ah (NA is the Avogadro number, e is the charge of one electron). Specific capacity may be calculated if molar capacity (Ah) is multiplied by number of moles in one kg (Q m /Ah kg-1) or in one dm3 (Qv /Ah dm-3) Theoretical specific capacity of a battery may be calculated by dividing the capacity of catode or anode material (they are always adjusted to be identical) by the mass (or volume) of both electrode materials and electrolyte, if it participates in chemical reaction. Practical specific capacity of a battery may be calculated by dividing the capacity of cathode or anode material by total mass of the battery. Practical specific capacity may be several times lower than theoretical one. This is due to the presence of various other materials in the construction of a battery, which enable its practical use. They are electronically conductive additives to low-conducting electrode materials, plastic binders, current collectors, separators, electrolyte and container. An additional latent capacity loss arises when battery is in use. Namely, no construction provides full utilization of electrode material, and moreover, it decreases with the increase of charging/discharging rate. The energy of a battery is the product of capacity and voltage. The unit of energy is Joule (1J= 1 C x 1 V = 1As x 1V = 1Ws ). For practic purposes 3600 times greater unit is used, called wat hour (1Wh = 1Ahx 1V ). Theoretical specific energy is the product of theoretical capacity and voltage, while practical specific energy is the product of practical capacity and voltage. Practical specific energy is lower than theoretical one due to the same factors causing the lowering of practical relative to theoretical capacity. Table 1. Molar mass (M), theoretical coulombic capacity per mole (QM ), specific capacity (Qm), density (), and volume capacity (Qv ) of some classic anode and cathode materials cathode PbO2 NiOOH AgO MnO2 O2 anode Pb Cd Zn Li H2 LaNi5H6 M (kg mol-1) 0.239 0.0917 0.1238 0.0869 0.032 M (kg mol-1) 0.2072 0.1124 0.0654 0.00694 0.002 0.4384 M-1 (mol kg-1) 4.18 10.9 8.08 11.5 31.25 QM (Ah mol-1 ) 53.6 26.8 26.8 26.8 107.2 QM (Ah mol-1 ) 53.6 53.6 53.6 26.8 53.6 160.8 M-1 (mol kg-1) 4.83 8.90 15.3 144.1 500 2.28 Qm (Ah kg-1) 224 292 216.5 308.4 3350 Qm (Ah kg-1) 259 477 819.6 3862 26800 367 (kg dm -3) 9.375 7.4 7.44 5 0.00143 (kg dm -3) 11.4 8.65 7.14 0.534 0.0000893 7.95 Qv (Ah dm-3) 2100 2161 1610.6 1542 4.79 Qv (Ah dm-3) 2951 4126 2925 2062 2.39 2917 The unit of specific energy is Wh kg-1, or Wh dm-3. It is also called energy density. Many factors influence the practical usability of an electrode materials (aggregate state, corrosivity, toxicity, price, cyclability of electrode materials), thus only few batteries experinced long term practical use, the mostly used will be described in continuation. 2. CHARACTERISTICS OF SOME CLASSIC BATTERIES The lead acid battery was dicovered in 1859 (Plante) [1]. Its anode consists of powdered lead and cathode of lead dioxide. The powders are fastened by means of binders within the lead grids serving as mechanic support and current collectors. The plate-formed electrodes are placed in sulfuric acid solution. The discharging assumes the following cathodic reaction: PbO2 + HSO4- + 3H+ + 2e- = PbSO4 + 2H2O, and the followi Pb + HSO4- = PbSO4 +H+ + 2ewhile chemical reaction of the battery reads: PbO2 + Pb + 2H2SO4 = 2PbSO4 + 2H2 2 + 1.690 – (-0.358 V) = 2.048V) Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 1-9, -Vanredno izdanje- So called Ni-Cd rechargeable battery was discovered in 1900.[1]. The cathodic material is NiOOH and the anodic material is powdery Cd. The electrolyte is concentrated KOH solution, which is not the reactant. The chemical reaction during discharging is Cd + 2NiOOH + 2H2O = Cd(OH)2 + 2Ni(OH)2 ( = 1.35 V) In 1866 Leclanché invented a primary battery consisting of a zinc anode and MnO2 cathode dipped in a jar of ammonium chloride solution. The chemical reaction in the Leclanche cell is: 2Zn + 4NH4Cl + 4MnO2 ZnCl2 + Zn(NH3)4Cl2 + 4MnOOH It provided 1.4 volts, and was not rechargeable. Table 2: Electrode materials, electrolyte, voltage, theoretical and practical energy density and practically achieved energy density of various batteries. Battery System Negative Electrode Positive Electrode Electrolyte Nominal Voltage (V) 2.0 1.2 Theoretical Specific Energy (Wh kg-1) 252 244 Practical Specific Energy (Wh kg-1 ) 35 50 Practical Energy Density (Wh l-1) 70 75 Pb/PbO2 Cd-Ni Pb Cd PbO2 NiOOH H2SO4 KOH Zn-AgO Zn AgO KOH 1.9 524 100 180 Ni-H2 H2 NiOOH KOH 1.2 434 55 60 Ni- MH H (as MH) NiOOH KOH 1.2 80 170 Zn O2 KOH 1.1 278 – 800 (depends on MH) 1320 Zn- Air 110 80 Table 1 shows molar and specific capacities of some classic (Pb, PbO2, Cd, NiOOH, Zn, MnO2, AgO) and some light (H2, Li) electrode materials. They illustrate that low density materials possess high specific capacity, and thus enable high specific capacity and specific energy of batteries, as evidenced in Table 2. Hovewer, their use in rechargeable batteries became technologically possible just in last three decades. 3. HYDROGEN AS ELECTRODE MATERIAL: Ni-MH BATTERY Since 1990ties the mobile telephony experineced explosive growth. Also, the oil crisis came back the idea of electrically powered cars. This forced extensive research of power sources of high energy density. High specific capacity of hydrogen attracted the care from 80ties. However, its very low energy density per volume unit presented a significant limiting factor for commercial use. Some authors proposed the battery of compressed hydrogen as anode and NiOOH as cathode in KOH solution, in a high pressure container of steel, however this battery did not experience mass production. Wide practical use found the hydrogen absorbing alloys, so called hydride alloys. Their origin was the hydride LaNi5H6 (Fig. 3) where hydrogen possesses the density close to the one of solid hydrogen, however the elements La and Ni carried practically whole mass of the electrode material [2]. It suffered from very slow diffusion coefficeint of hydrogen. The replacement of Ni by some other metals enabled faster diffusion of H atoms, lower corrosion ability and higher cycle life. Instead of pure lantanum, which is expensive, equal results were obtained with the much cheaper mixture lantanides called Mishmetal Mm, (typically composed of 50-55 % Ce, 18-28 % La, 1218 % Nd, 4-6 % Pr) [3,4.]) Typical commercially used alloys of AB5 type consisted of at least six elements for example Mm(Ni3.6Mn0.4Al0.3Co0.7)1.00. To shorten diffusion path, the alloy is used as micron sized powder, glued to a nickel or stainless steel grid. Fig 3. Hexagonal elemental cell of intermetallic compound LaNi5. Hydrogen atoms are placed in positions 3f i 6m [2]. 3 S. Mentus: CONTEMPORARY RESEARCH OF LITHIUM BATTERIES The reactions of charging and discharging of Ni-MH battery are: charging M + xNi(OH)2 MHx + xNiOOH dischaging The mean voltage of this battery is 1.2 V. Its energy was shown in Table 2, and one can see a significatly better characteristic in relation to lead acid and NiCd batteries. Hydride materials were used mostly between 1980 i 1995, for mobile thelepones. However, they have stepped back from market since a new and strong systems came into sight, Liion batteries. In another way, hydrogen was planned to be used in pair with oxygen in fuel cells. Due to the slow kinetics of oxygen and hydrogen electrode reactions, fuel cells require the use of catalyst based on nanodispersed platinum. However, the idea with fuel cells is temporarily stepped back, not only due to the limited resources of platinum, but primarily due to a weak hope that the problem of the supply of roads by hydrogen may be solved in near future. 3. Li-ION BATTERIES According to the Table 1, lithium possess high specific capacity, and accordingly, may provide high battery energy. Its first use originated in 70-ties in a form of primary batteries, since elementary lithium was unsuitable for secondary batteries, due to passivation, reactivity toward electrolyte and dendrite development on cycling. The earliest primary lithium battery was Li/MnO2 in organic solution of Li salt, with the voltage 3 V [5, 6]. Since late 80ties the materials able to accept and release lithium revesibly were published. Such behavior displayed solid materials of layered crystal structure, called hosts, with strong ionic bond inside layer, and weak Van-der-Vaals bond between layers. Lithium or other chemical species, called guest, inserted between host lattice layers, under consumption of equivalent charge needed to keep electric neutrality. The compounds of this type have been known in inorganic chemistry as insertion or intercallation compounds. The intercalate materials LiCoO2, [7] LiNiO2 and LiMn2O4, displayed excellent electrochemical cyclability, high electrode potential of 4 V against Li/Li + reference electrode (Table 3), and high electronic conductivity, being thus suitable to serve as cathodes. However, the problem of anode was more serious. Lithium metal was unsuitable due to the limited cycle life to several cycles only. Just in 1989 Japanese electrochemists published that graphite can be electrochemically intercalated with lithium (Fig 4). The intercalate with maximum lithium content, LiC6, displayed electrode potential very close to that of lithium metal, and the electrochemical intercalation was reversible [8, 9]. Carbon host prevented the appearance of dendrites on cathodic deposition, and several hundred of lithiation/delithiation cycles became attainable. Due to the participation of carbon, the specific capacity of lithiated graphite is roughly 10 times smaller (about 370 Ah kg-1) than that of metallic lithium (3862 Ah kg-1), however his cycling reversibility and long cycle life, provided its dominant application in secondary lithium batteries and enabled a rapid expansion of lithium batteries in practice. Only few years after the publications of carbon lithiation, three companies started the commercial production of secondary lithium batteries for mobile electronic devices in which both anode and cathode were intercalate compounds: Moli Energy Ltd. (C/LiNiO2), Bell Communication Research (Bellcore) (C/LiMn2O4) and Sony Energytec. Inc., (C/LiCoO2). Fig 4 The scheme of the LixC crystal lattice 4 Fig. 5 . The scheme of a Li-ion rechargeable cell. The direction of charge movement on charging is presented Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 1-9, -Vanredno izdanje- Typically, lithium-ion battery is composed of graphite anode, lithiated manganese, cobalt or nickel oxide as cathode, and electrolyte solution, usually LiPF6 dissolved in a solvent mixture ethylene carbonate + dimethyl carbonate. The work principle of a Li-ion cell is shown in Fig. 5. The active electrode materials, attached by means of polymeric binder as thin layers on metallic collectors, usually copper foil serving as anode and aluminum foil as cathode collector. The nanoporous polypropylene membrane separates anode and cathode, and allow the transport of electrolyte. Graphite and completely lithiated oxide present discharged anode and cathode stages. During the charging, lithium ions insert into graphite under consumption of electrons, according to the reaction: 6C + Li+ + e- = LiC6 And this is accompanied by the shift of potential toward the one of metallic lithium. At the same time, on the other electrode, delithiation occurs under electrons deliberation, according to the equation (if, for instance, LiCoO2 presents the cathode material): LiCoO2 = Li(1-x)CoO2 + xLi+ + xe- (0 ≤ x ≤ 1) and simultaneously the potential shifts toward more than 4 V versus lithiated graphite. Table 3. Molar mass (M), theoretical coulombic capacity per mole (QM ), specific capacity (Qm), density (), and volume capacity (Qv ) of anode and cathode materials of lithium-ion batteries. Anode LiC6 Cathode LiFePO4 LiCoO2 LiNiO2 LiMn2O4 M (kg mol-1) 0.072 QM (Ah mol-1 ) 26.8 M-1 (mol kg-1) 13.9 Qm (Ah kg-1) 372 (kg dm -3) 2.25 Qv (Ah dm-3) 837 M (kg mol-1) 0.158 0.0979 0.0976 0.181 QM (Ah mol-1 ) 26.8 26.8 26.8 26.8 M-1 (mol kg-1) 6.33 10.2 10.2 5.53 Qm (Ah kg-1) 169.6 137 192 148 (kg dm -3) 3.60 5.16 4.78 4.28 Qv (Ah dm-3) 610.6 706 919 634 Table 4. Li-ion battery type, voltage, theoretical and practical specific energy Battery System Negative Electrode Positive Electrode Electrolyte Nominal Voltage (V) Theoretical Specific Energy (Wh kg -1) Practical Specific Energy (Wh kg-1 ) Practical Energy Density (Wh dm-3 ) Li-ion LiC6 LixCoO2 PC or DMC + LiPF6 3.7 580 120 ~200 Li-ion LiC6 LiMn2O4 PC or DMC + LiPF6 3.7 390 200 ~200 Li-ion LiC6 LiFePO4 PC or DMC + LiPF6 3.2 390 >120 ~200 Therefore, during charging, summary chemical reaction is: 6C + LiCoO2 = LixC6 + Li(1-x)CoO2 and the charging should be finished when the potential difference reaches about 4.5 V. Lithium does not exist as metal but travels between electrode materials through electrolyte as Li ion. This explains the name Li-ion battery. A Li-ion battery never attains 100% of the theoretical capacity being 372 Ah kg -1 for LiC6. Namely, on changing from fully intercalated LiC6 to Li0.4C6 and below, the voltage of the battery falls by up to 0.3V. Thus nominal LiC 6 capacity rounds about 180 Ah kg-1, Moreover, the theoretical capacity of a cell holds at very low currents. As soon as a measurable current is drawn from a cell it loses voltage and thus the capacity (see Fig 7). The theoretical specific energy of a LiIon battery amounts between 400 and 450 Wh/kg. The actual specific energy achieved is between 70 and 120 Wh/kg. However, this is still always much higher than classic lead acid and Ni/Cd batteries, and one should not forget a much higher environmental friendliness important in gross use. Relatively high capacity and energy density, flexibility in design enabled the substitution of conventional secondary batteries. Li-ion batteries are now prevailingly used in portable electronic devices, mobile phones (57 %), notebook computers (31.5%) and cameras (7.4%). Their application has also been extended to electric vehicles, space application, military vehicles etc. 5 S. Mentus: CONTEMPORARY RESEARCH OF LITHIUM BATTERIES 3.1. LiFePO4, A NEW CATHODE MATERIAL The compound of olivine structure LiFePO4 was reported in 1997 [10] Thanks to its high theoretical capacity of 170 Ah kg-1, a very flat plateau (3.5 V vs. Li+/Li) with the iso-structure phase transition LiFePO4 = FePO4 on charging (Fig 6), environmental appropriateness and low cost compared to LiCoO2, it presents a very desirable cathodic material for Li ion batteries [10]. In pioneering studies, its low conductivity of nearly 10-9 S cm-1 acted rather discouraging in sense of its practical use [10,11]. Later, various ways were applied to overcome this drawback: coating the particles with electronically conductive agent such as carbon [12-18] or Fe2P [19-21], particle size reduction [12, 22], doping with supervalent cations [23-28], and doping by anions [29, 30]. Fig 8 illustrates how the synthesis of nanoparticles of LiFePO4 of ~70 nm in diameter, coated by thick carbon layer displayed acceptable capacity loss on enlarging discharging rate. The C layer enables unrestricted encounter of electrons and lithium ions whenever they cross the C/electrolyte border. Wang et al. [31] reported the way to apply homogeneous thin C layer by polymerization of polyaniline over olivine particles and subsequent carbonization of polymer shell. The PANI layer prevented the LiFePO 4 particles to grow over 20-40 nm. The composite delivered 168 mAhg-1 (~theoretical capacity) at the discharging rate 0.6 C, and 90 mAhg-1 at 60C, and only 5% capacity fade after 1100 charging/discharging cycles [31]. A particular improvement in the rate capability and capacity retention of LiFePO4/C composite was achieved by vanadium doping [25-28]. Fig. 6. Crystal structure of (a) LiFePO4 and (b) FePO4 Fig 7. The dependence of capacity of LiFePO4/C composite, with particle size ~70 nm, on discharging rate (1C = 170 mA g-1) [15] 6 Fig 8 Core-shell structure of LiFePO4 nanoparticles enwrapped homogeneously by carbon layer [31]. Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 1-9, -Vanredno izdanje- 3.2 THE SEARCH FOR NEW ANODE MATERIALS From 1970ties the reports appeared in the literature that metals or semi-metallic elements alloy with lithium at room temperature on cathodic deposition from non-aqueous electrolyte, displaying high theoretical capacity, 900 Ah kg-1 and above, [32] compared to graphite which has a theoretical capacity of 372 Ah kg -1. The alloys between Si and Li of the composition Li22Si5, delivered a theoretical capacity of 4200 Ah kg-1. However, a huge volume change during charging (up to 250%) was an obstacle for their use in lithium-ion batteries. If we consider the available empty volume in the cell, compared to the volume expansion of graphite (less than 20%), the Si volume expansion cannot be tolerated unless reduced below 40%. As a solution, composites of Si nanoparticles and graphite have been investigated [33] with the capacity over 1000 Ah kg -1 however, the capacity retention was rather weak. Parallel to silicone, SiO anodes have been widely investigated, under the assumption that it consists of amorphous Si domains and amorphous SiO2 domains, being both reactive with lithium according to the equations [34]: Si + xLi + + x e_= LixSi, and SiO2 + yLi+ + ye = Li2O + Li silicates. The Li2O and lithium silicates serve as the amorphous matrix. Accordingly, the volume-expansion ratio is expected to be reduced, compared with Si. 4. THE PERSPECTIVE OF USE OF Li-JON BATRERIES IN ELECTRIC CARS The idea of electric car is very old. For instance, in 1900 a model of electric car was exposed with the electric motors in the wheels. Hovewer, due to the small autonomy range it did not withstand the competition of cheap fossil fuels. After the oil crisis in ~90ties the expectations arose that fossil fuel in automobiles may be replaced by emerging type batteries. Just several years ago, Lithium-ion (Li+) batteries came in focus after fuel cells. Li-ion batteries just revolutionized the portable electronics market as they offer high energy density, long shelf life, and a wider temperature of operation over conventional aqueous electrolyte-based battery systems. To estimate the chance of development of electric cars powered by Li-ion batteries, one should assume that an average European car consumes 8.6 l petroleum per 100 km, which, considering the mean heat of combustion of gasoline/diesel fuel (of ~ 33.8 MJ dm-3 ~ 9400 kWh dm-3) with roughly 25% efficiency of engine, corresponds to roughly 20000 Wh of mechanical energy, or 100000 Wh for 500 km of autonomy. Although theoretical specific energy in today’s Li-ion batteries is 400-450 Wh kg-1, the storage of electricity is in praxis limited to 200 Wh kg−1 or 200000 Wh m−3. Assuming full efficiency of the electric work to mechanical work conversion, battery required for a 500 km driving range would have a weight of 500 kg, a volume of 2.5m3 and would cost 50 000 Euro (accounting with the today’s price of nearly 500 Euro per 1 kWh). If such amount of energy one tries to obtain from lead acid batteries, about 3000 kg batteries would be required. This is approx. 3 times the mass of a middle empty car (1000 kg). Fig. 9. Estimated course of the prices of Li-ion batteries per 1KWh in the future The bar segments from top downward: other costs, maintenance costs, utility costs, material costs, labour costs and investment costs [35] Since the difference between the theoretical and todays practical energy, together with oversized initial production costs, leaves the space for further economization, the planners predicted the decreasing trend of price per one kWh of energy of Li-ion batteries shown in Fig 9. In 2018 one should expect relatively economic electric cars, equivalent to today’s cars with internal-combustion engines [35]. Since car powered by Li-ion batteries is not far from reality, many automobile companies develop their own models, which do not differ in size and appearance from today’s standard cars. Acknowledgements: The Ministry of Education and Science of Serbia supported this study through the project III 450104. Serbian Academy of Sciences and Arts supported the study through the project F1190. 7 S. Mentus: CONTEMPORARY RESEARCH OF LITHIUM BATTERIES REFERENCES [1]. S. Mentus, Elektrohemija, University of Belgrade, Faculty of Physical Chemistry 2008, [2] M. Okada, T.Kuriiwa, A.Kamegawa, H.Takamura, Role of intermetallics in hydrogen storage materials, Mater. Sci. . Eng., A 239-331 (2002) 305-312 [3]. H. Ogawa, M. Ikoma, H. Kawano, I. Matsumoto, Power Sources 12, in T.Keily and B.W. Baxter (Eds.) Int. Power Sources Syrup. Committee (1989) 393 [4] M.Matsuoka M. Terashima, C. Iwakura, Effect of alloy composition on charge and discharge characteristics of the negative electrode for nickel-hydrogen batteries, Electrochim. Acta 38 (1993) 1087-1092 [5] H. Ikeda, T. Saito, H. Tamaru, Lithium-Manganese Dioxide Cell 1., Denki Kagaku 45 (1977) 314-3 [6] H. Ikeda, S. Uena, T. Saito, S. Nakaido, H. Tamaru, Lithium-Manganese Dioxide Cell 2, Denki Kagaku 45 (1977) 391-395. [7]. J.J. Auborn, J.J. 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Ahn, New approach for synthesis of carbon-mixed LiFePO4 cathode materials, Electrochim. Acta 50 (2004) 421. [13] D. Jugović, D.Mitrić, N.Cvjetićanin, B.Jančar, S.Mentus, D.Uskoković, Synthesis and characterization of LiFePO4 /C composite obtained by sonochemical method Solid State Ionics 179 (2008) 415-419. [14 ] I. Belharouak, C. Johnson, K. Amine, Synthesis and electrochemical analysis of vapor-deposited carbon-coated LiFePO4, Electrochem. Commun. 7 (2005) 983. [15] M. Vujković, I. Stojković, N. Cvjetićanin, S. Mentus, Gel-combustion synthesis of LiFePO4/C composite with improved capacity retention in aerated aqueous electrolyte solution, Electrochim. Acta, 92 (2013) 248-256 [16 ] J. Wang, X. Sun, Understanding and recent development of carbon coating on LiFePO4 cathode materials for lithium-ion batteries, Energ. Environ. Sci. 5 (2012) 5163 [17] D. Jugović, D. Uskoković, A review of recent developments in the synthesis procedures of lithium iron phosphate powders, J. Power Sources 190 (2009) 538, [18] L. Su, Y. Jing, Z. Zhou, Li ion battery materials with core–shell nanostructures, Nanoscale 3 (2011) 3967 [19] P.S. Herle, B. Elis, N.Coombs, L.F. Nazar, Nano-network electronic conduction in iron and nickel olivine phosphates, Nat.Mater.3 (2004) 147. [20] Y.-H. Rho, L.F. Nazar, L. Perry, D. Ryan, Surface chemistry of LiFePO4 Studied by Mossbauer and X-ray photoelectron spectroscopy and its effect on electrochemical properties, J. Electrochem. Soc. 154 (2007) A283. [21] Md M. Rahman, J.Z. Wang, R. Zeng, D. Wexler, H.K. Liu, LiFePO4-Fe2P-C composite cathode: An environmentally friendly promising electrode material for lithium-ion battery, J. Power Sources 206 (2012) 259. [22] Z.Liu, C.Cao, Enhanced electrochemical performance of nano-sized LiFePO4/C synthesized by an ultrasonic assisted co-precipitation method, Electrochim. Acta 55 (2010) 4694. [23] S.-Y. Chung, J.T. Bloking, Y.-M. Chiang, Electronically conductive phospo-olivines as lithium storage electrodes, Nat. Mater. 1 (2002) 123. [24] D.Y. Wang, H. Li, S.Q. Shi, X.J. Huang, L.Q. Chen, Improving the rate performance of LiFePO4 by Fe-site doping, Electrochim. Acta 50 (2005) 2955. [25] J.F. Ni, N.H. Zhou, J.T. Chen, X.X. Zhang, LiFePO4 doped with ions prepared by co-precipitation method, Mater. Lett. 59 (2005) 2361. [26] J. Hong, C.S. Wang, X. Chen, S. Upreti, and M.S. Whittingham Vanadium modified LiFePO4 cathode for Li-ion batteries, Electrochem. Solid-State Lett.12 (2009) A33-A38. [27]. M. Vujković, D. Jugovic, M. Mitric, I. Stojković, N. Cvjetićanin, S. Mentus, The LiFe(1-x)VxPO4 /C composite synthesized by gel-combustion method, with improved both rate capability and cycle life in aerated aqueous solutions, Electrochim. Acta, in press, DOI:10.1016/j.electacta.2013.07.219 [28 ] L.-L. Zhang, G. Liang, A. Ignatov, M. C. Croft, X.-Q. Xiong, I-M. Hung, Y.-H. Huang, X.-L. Hu, W.-X. Zhang, Y.-L. Peng, Effect of Vanadium Incorporation on electrochemical Performance of LiFePO4 for Lithium-Ion Batteries, J. Phys. Chem. C 115 (2011) 13520 [29] X.-Z. Liao, Y.-S. He, Z.-F. Ma, X.-M. Zhang, L. Wang, Effects of fluorine-substitution on the electrochemical behavior of LiFePO4/C cathode materials, J. Power Sources 74 (2007) 720 [30] C.S. Sun, Y. Zhang, X.J. Zhang, Z. Zhou, Structural and electrochemical properties of Cl-doped LiFePO4/C, J. Power Sources 195 (2010) 3680 [31] Y. Wang, Y. Wang, E. Hosono, K. Wang, H. Zhou, The design of a LiFePO4 / carbon nanocomposite with a core– shell structure and its synthesis by an in situ polymerization restriction method, Angew.Chem.Int.Ed. 47 (2008) 74617465. 8 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 1-9, -Vanredno izdanje[32] M. R. Palacin, Recent advances in rechargeable battery materials: a chemists perspective, Chem. Soc. Rev. 38 (2009) 2565 – 2575 [33] K. T. Lee, J. Cho, Roles of nanosize in lithium reactive nanomaterials for lithium ion batteries, Nano Today 6 (2011) 28 – 41; [34] H. S. Choi, K.H. Yew, K.Y. Lee, M. Sung, H. Kim, S.S.Kim, Effect of fluoroethylene carbonate additive on interfacial properties of silicon thin-film electrode, J. Power Sources 161 (2006) 1254-1259 [35]. M&V Group, brochure, http://donar.messe.de/exhibitor/hannovermesse/2011/C11229/m-w-group-presentationmodular-factory-for-li-ion-batteries-eng-134529.pdf САВРЕМЕНА ИСПИТИВАЊА ЛИТИЈУМСКИХ БАТЕРИЈА Славко Ментус Универзитет у Београду, Факултет за физичку хемију, Студентски трг 12, 11185 Београд, Србија, e-mail : slavko@ffh.bg.ac.rs Од ~90-тих интезивирана су очекивања да батерије могу да замене фосилна горива за погон аутомобила. Класичне оловне и Ni-Cd батерије су непогодне за то због превисоке властите масе (мале специфичне енергије) и токсичности. До 2010-тих решење је тражено у водоничним горивним ћелијама али последњих неколико година пажња је сконцентрисана на литијумске батерије. У почетку, техничка решења батерија за мобилне телефоне пресликавана су на батерије за погон аутомобила, са анодом од LiCx и катодом од LiNiO2 ili LiCoO2, међутим данас се разматра скоро искључиво композит на бази LiFePO4 – због ниске цене и еколошке прихватљивости. У овом раду направљен је преглед карактеристика класичних и савремених батерија. Овај преглед илуструје како је увођење литијум-јонских батерија заједно са савременом нанотехнологијом обезбедило скоковит напредак у достизању високе специфичне енергије, довољан да омогући прелазак са мотора са унутрашњим сагоревањем на електричне моторе у аутомобилима. Кључне речи: класичне батерије, електродни материјали, литијум-јонске батерије, специфична енергија, 9 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 11-16, --Vanredno izdanje-- POTROŠAČI I BEZBEDNOST HRANE Baltić Ţ. Milan1*, Đurić Jelena1, Mandić Snjeţana2, Pećanac Biljana3, Lončina Jasna1 Univerzitet u Beogradu, Fakultet veterinarske medicine Beograd, Srbija, http://www.vet.bg.ac.rs/ 2 Univerzitet u Banjoj Luci, Tehnološki fakultet, RS, BiH, http://www.tfbl.org 3 JU Veterinarski institut Republike Srpske‖Dr Vaso Butozan‖ Banja Luka, RS,BiH, http://www.virsvb.com 1 ISSN 2232-755X DOI: 10.7251/GHTE13VI011B UDC 006.4:[663/664:658.562 Bezbednost i kvalitet hrane, u današnje vreme, igraju značajnu ulogu u odrţavanju zdrаvlja potrošača, kao krajnje karike u lancu ishrane. Bolesti prenosive hrаnom predstаvljаju problem svakog pojedinca, аli su od posebnog znаčаjа zа decu, stаrije osobe i imunokompromitovane osobe. Iаko je široko prihvаćena teorija od strаne stručnjаkа za hranu dа se mnogi slučаjevi bolesti prenosivih hranom jаvljаju kаo posledicа neprаvilnog rukovаnjа i pripreme hrane od strаne potrošаčа, sаmi potrošаči i dаlje nisu svesni ove činjenice. Ličnа higijenа je dobro poznat nаčin na koji ljudi mogu dа smаnje rizik od ovih bolesti. MeĎutim, mаlo se znа o stvаrnoj primeni lične higijene i sаnitаrnih ponаšаnjа u kući. Zadatak mnogih istraţivanja jeste da se procene znanja potrošača u vezi sa bezbednošću hrane i utvrdi dа li znаnje odgovara primenjenoj praksi. Ovаkve informаcije mogu biti od velike pomoći profesionalcima koji se bave edukacijom potrošača o bezbednosti hrаne, a sve u cilju dа potrošаči postanu svesni svoje kritične uloge u smаnjenju rizika bolesti prenosivih hranom. Ključne riječi: potrošači, rizik, bezbednost hrane UVOD Zdrav ţivot je termin koji se javlja sredinom 20. veka i kao termin se ne pominje u Larusovoj enciklopediji, a označava nastojanje da se prema sebi i svome telu, načinu ishrane i ţivotu uopšte, odnosimo maksimalno higijenskim u skladu sa znanjima jednog vremena, običajima koji vaţe u datom društvu i u datom vremenu (1). Briga za zdravlje prati čoveka od njegovog postanka. Do danas svima poznate, i naučno dokazane, veze izmeĎu ishrane i zdravlja čovek je iskustveno došao još dok je bio lovac i sakupljač plodova prirode. Ova veza je i dalje predmet bojnih istraţivanja koja daju, ne tako retko, oprečne rezultate i zaključke. Rezultati ovih istraţivanja realizuju se različitim preporukama u ishrani, odnosno dijetama. Nesporno je da su dijete delotvorne u brojnim slučajevima, ali i tu ima pogrešnih koraka. Kada se govori o hrani, treba znati da je hrana pored onog najvaţnijeg nutritivnog aspekta, čoveku i zadovoljstvo. Hedonski pristup ishrani vodi ka njenoj jednoličnosti, neizbalansiranosti i neminovno do narušavanja zdravlja. Osnov pravilne ishrane je u raznovrsnosti hrane i umerenosti kada je u pitanju količina hrane (1). Čuvari tradicije, najverniji i najbolji su porodice, porodična domaćinstva. To je njihova identifikacija sa rodnim tlom. Tu tradiciju oni nose sa sobom ma gde ţiveli. Za Srbiju kao seljačku zemlju primarni cilj seoske ekonomije bilo je direktno odrţanje seoske porodice. Porodica je bila osnovna ekonomska i potrošačka jedinica. Najveći deo tradicionalnih proizvoda proizvodi se na zanatski način, u malim objektima, a dobar deo njih u porodičnim domaćinstvima. Značajan deo te proizvodnje namenjen je za sopstvenu, porodičnu potrošnju (2). Priroda je, konfiguracijom zemljišta, njegovom pedološkom strukturom i klimom omogućila Srbiji da ima velike i raznolike mogućnosti poljoprivredne proizvodnje. U toj proizvodnji stočarstvo ima posebnu ulogu, s obzirom na dugu tradiciju gajenja svinja, ovaca i goveda. Za stočarsku proizvodnju vezuje se i izrada stočarskih proizvoda, posebno hrane, meĎu kojima su i tradicionalni proizvodi od mesa (goveĎeg, ovčjeg, svinjskog). Očuvanje tradicije u izradi proizvoda od mesa vezuje se, pre svega, za proizvodnju u domaćinstvima i male proizvodne subjekte. Pri tome, bez obzira gde se proizvode i koliko imaju dugu tradiciju, ovi proizvodi moraju da budu bezbedni po zdravlje ljudi. To se postiţe, pre svega, poštovanjem principa dobre proizvoĎačke i dobre higijenske prakse i primenom HACCP sistema. U manjim proizvodnim pogonima primena HACCP sistema zahteva izvesne modifikacije. Za one koji tradicionalne proizvode pripremaju u domaćinstvima treba doneti posebne propise po ugledu na zemlje Evropske Unije i neke susedne zemlje, a koji bi ovim proizvoĎačima omogućili da se sa svojim proizvodima naĎu na trţištu (2). * Korespodentni autor: Milan Ţ. Baltić, 1Univerzitet u Beogradu, Fakultet veterinarske medicine Beograd, Srbija, email: baltic@vet.bg.ac.rs 11 M.Ţ. Baltić i sar.:POTROŠAČI I BEZBEDNOST HRANE Razume se da mondijalizaciju i industrijalizaciju prehrambenih proizvoda prati i potreba standardizacije i ujednačenja kvaliteta proizvoda, ali i savremeni pristup bezbednosti hrane koji podrazumeva i potpunu kontrolu proizvodnog procesa u celom lancu proizvodnje („od njive do trpeze―). Propisi o bezbednosti hrane i «politika kvaliteta» treba čoveku da obezbede hranu koja neće zbog prisustva bioloških, hemijskih i fizičkih opasnosti, iznad propisanih nivoa (za neke postoji i nulta tolerancija), ugroziti zdravlje potrošača. Nema sumnje, da standardizacija proizvoda olakšava promet hrane, ali je doprinela i nekim ograničenjima. To se, pre svega, odnosi na neke nacionalne i regionalne specijalitete kad je u pitanju gotova hrana. Činjenica je da sve što je namenjeno ishrani ljudi mora biti i bezbedno za njihovo zdravlje (2). Zbog sve veće zabrinutosti potrošača, ali i drţavnih organa za bezbednost hrane usledile su aktivnosti koje su vodile ka pooštravanju zakonske regulative i uvoĎenjem standarda koji treba da unaprede upravljanje bezbednošću hranom. Svi standardi polaze od činjenice da subjekti u lancu hrane posluju u skladu sa lokalnom zakonskom regulativom uz uvaţavanje meĎunarodno usvojenih pravila. Tako se moţe govoriti o nekoliko nivoa primene različitih pravila: a) Globalna – smernice svetske zdravstvene organizacije (WHO) i Codex Alimentarius Commission (CAC); b) Regionalna – EC No. 178/2002 (Regulation of the european parliament and of the councilof 28 January 2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety); c) nacionalna regulativa – Zakon o bezbednosti hrane d) ISO standardi i drugi standardi iz oblasti bezbednosti hrane – ISI 22000:2005 Food Safety Management System; e) Interni standardi velikih korporacija – npr McDonalds Food Safety System i dr. (3). Primena pomenutih standarda u proizvodnji hrane je poţeljna i neophodna u proizvodnji bezbednog proizvoda. Kod nas ovi standardi su prihvaćeni, a na njihovom uvoĎenju u praksu još uvek se radi. BEZBEDNOST HRANE Pod bezbednom hranom podrazumeva se hrana koja neće škoditi potrošaču, kada se priprema i/ili konzumira u skladu sa namenom. Kvalitet hrane moţe da se definiše na različite načine. Pod kvalitetom, u širem smislu, a sa stanovništva propisa koji regulišu ovu materiju, podrazumeva se higijenska ispravnost (bakteriološka i parazitološka ispravnost, prisustvo štetnih materija, organoleptička ispravnost) i kvalitet u uţem smislu pod kojim se podrazumevaju hemijske, fizičke i ogranoleptičke osobine. Granice izmeĎu higijenske ispravnosti i kvaliteta ne treba meĎutim postavljati, jer to često nije moguće. Za higijensku ispravnost i kvalitet namirnica odgovorni su drţavni organi, proizvoĎači (vlasnici) i potrošači. Danas se bezbednost hrane zasniva na dobroj proizvoĎačkoj praksi (GMP), dobroj higijenskoj praksi (GHP) i HACCP sistemu u kome se od proizvoĎača traţi da identifikuje opasnosti (hazarde) koji ugroţavaju bezbednost proizvoda i da ih eliminiše ili kontroliše (4). Vrednost savremenog pristupa bezbednosti hrane ogleda se u tome što je on primenljiv na sve segmente (karike) u njenoj proizvodnji ili, kako se to uobičajno kaţe, primenjuje se od ‖farme do trpeze‖. Poslednji kontrolisani segment u lancu hrane je maloprodaja hrane ili mesto gde hrana postaje dostupna potrošaču (restorani npr.). MeĎutim, apsolutnu bezbednost hrane, ma koliko sistem bio dobar, funkcionalan, kontrolisan i proveravan nije moguće obezbediti i garantovati (5). Razumevanje bezbednosti hrane je koncept koji se odnosi na tehnologije i propise, proizvoĎače i potrošače. Danas, naročito u razvijenim zemljama, je sve zastupljenija ishrana izvan kuće (brza hrana), kao i upotreba u kući potpuno ili delimično pripremljene hrane. To nije rezultat popularnosti, već logičan rezultat koji proizilazi iz specifičnog problema nedostatka vremena potrošača i njihove organizacije svakodnevnog ţivota (1). Stanovništvo SAD-a troši 40-50% prihoda namenjenih ishrani na tzv. brzu hranu, odnosno ishranu izvan kuće, dok ljudi u Evropi troše oko 26% svojih prihoda. Tradicionalno shvatanje nabavke namirnica se stalno menja. Učestalost i vrsta alimentarnih infekcija se, takoĎe, menja. Istraţivanjima je utvrĎeno povećanje virusnih infekcija u odnosu na klasične bakterijske infekcije (6). Za pravilno razumevanje termina bezbednosti hrane potrebna je jasna koordinacija i edukacija u lancu hrane. Kada je bezbednost hrane u pitanju, i potrošač i proizvoĎač moraju „govoriti istim jezikom―, odnosno moraju se razumeti. To znači da se moraju da razmotre propisi i naučni i tehnički principi kako bi se osigurali bezbednost sirovina, ambalaţe, i drugih sporednih materijala koji se koriste u proizvodnji hrane i njenom prometu. Nepaţnja, nemar, greške ili neoprezne aktivnosti tokom rada mogu biti fatalne za potrošače (6). BOLESTI PRENOSIVE HRANOM Bolesti prenosive hranom (definisane kao „bolesti infektivne ili toksične prirode uzrokovane, ili one za koje se misli da su uzrokovane, konzumiranjem hrane i vode) postale su jedan od najrasprostranjenijih javno-zdravstvenih problema u svetu danas. Bolesti prenosive hranom u vezi sa mikrobiološkim patogenima, biotoksinima i hemijskim kontaminentima u hrani predstavljaju ozbiljnu opasnost po zdravlje miliona ljudi (7). 12 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 11-16, --Vanredno izdanje-- U najvećem broju slučajeva bolesti prenosive hranom nisu retkost i vezane su, pre svega, za biološke opasnosti, odnosno bakterije. Ako su ova oboljenja ljudi epidemijskog karaktera, razumljivo je da ona privlače veliku medijsku paţnju i izazivaju zabrinutost potrošača. Bolesti prenosive hranom ne predstavljaju samo opasnost po zdravlje i ţivot ljudi, već prouzrokuju ogromne ekonomske gubitke (bolovanja, lečenja). Pravu učestalost pojava bolesti prenosivih hranom je teško utvrditi, jer se slučajevi bolesti retko prijavljuju. Iako bolesti prenosive hranom mogu biti ozbiljne i fatalne, blaţi slučajevi često nisu otkriveni kroz rutinski nadzor. Veruje se da je većina (95%) slučajeva bolesti prenosivih hranom sporadična. Ovi slučajevi, kao i male epidemije koje potiču iz domaćinstava, po pravilu uključuju pojedince ili mali broj ljudi i samim tim je manja mogućnost da će biti identifikovane od strane nadleţnih organa za javno zdravstvo. Dakle, stvarni odnos epidemija izazvanih hranom i pojedinačnih slučajeva poreklom iz domaćinstava verovatno je mnogo veći nego što je to prijavljeno (8). Tokom protekle decenije više od 87% prijavljenih bolesti prenosivih hranom u Velikoj Britaniji, Evropi, Australiji, Novom Zelandu, Sjedinjenim Drţavama i Kanadi bile su u vezi sa hranom koja se priprema ili konzumira kod kuće (grafikon 1). Istorijski gledano, najčešći uzrok prijavljenih epidemija bolesti prenosivih hranom u vezi sa domaćinstvima izazvane su salmonelama. Epidemiološke studije su pokazale da sporadični slučajevi ili male epidemije u domovima čine većinu incidenata trovanja hranom. Procenjeno je da privatna domaćinstva u Velikoj Britaniji čine više epidemija oboljenja hranom nego sva ostala prijavljena mesta zajedno (7, 8). 60 % 50 40 30 20 10 0 a sk le g En el iV s ka us c an Fr ka ač m Ne ka Irs ja ni a Šp aj Šv ka rs a c D SA Grafikon 1. Prijavljeni slučajevi pojave bolesti prenosivih hranom u vezi sa pripremom hrane u domaćinstvima (8) Graph 1. Reported cases of foodborne diseases associated with the preparation of food in the households (8) Oboljenjа koja nastaju konzumiranjem kontaminirane hrаne predstavljaju pretnju po zdrаvlje i dobrobit potrošаčа, uključujući velike ekonomske gubitke pojedinacа. Iаko većina potrošača imа tendenciju dа se oboljenja vezana za hranu povezuju sa ishranom izvаn kuće, istrаţivаnjа pokаzuju dа se mnogi slučаjevi trovаnjа hrаnom javljaju upravo pri pripremi hrane u domaćinstvima. Mnogi od ovih slučаjevа su u vezi sа nаjčešćim greškаmа u primeni higijenske prаkse pri pripremi hrane kod kuće (9). Sprečavanje bolesti prenosivih hranom podrazumeva saradnju u svim fazama lanca ishrane. Nijedna faza ne nosi isključivo krivicu ili odgovornost. Efektivne strategije bezbednosti hrane u cilju smanjenja rizika od kontaminacije patogenima zahtevaju dvostruki pristup integrisanja edukacije i propisa. Na meĎunarodnom planu prioritet ima implementacija propisa u svim sektorima različitih prehrambenih industrija i razvoj edukativne svesti potrošača. U Velikoj Britaniji, primarni ciljevi Organa zaduţenih za bezbednost hrane obuhvataju zaštitu javnog zdravlja i interesa potrošača. Slično tome, u Sjedinjenim Američkim Drţavama, sistem bezbednosti hrane se zasniva na interakciji izmeĎu saveznih organizacija, kao što su Departman za agrikulturu, Ministarstvo za hranu i lekove, Sluţba za inspekciju i bezbednost hrane, Departman za ljudsko zdravlje i usluge, Agencija za zaštitu ţivotne sredine i Inspekcijska sluţba za zdravlje ţivotinja i bilja. U Australiji i Novom Zelandu, nezavisna organizacija poznata kao ANZFA (Australia and New Zealand Food Authority) saraĎuje sa drugim organima za zaštitu zdravlja i bezbednosti ljudi kroz odrţavanje bezbednosti hrane u lancu snadbevanja (10). Kako nije moguće obezbediti i garantovati apsolutnu bezbednost, neophodno je započeti edukaciju potrošača. Zakon nikada u potpunosti ne moţe da zaštiti društvo. 13 M.Ţ. Baltić i sar.:POTROŠAČI I BEZBEDNOST HRANE SVESNOST I INFORMISANOST POTROŠAČA Kontrola bezbednosti hrane prestaje praktično onog momenta kada hrana dospe u korpu potrošača. Ključni razlozi velike učestalosti bolesti prenosivih hranom vezani za domaćinstvo odnose se na znanja i informisanost potrošača. Današnji potrošač treba da poznaje, odnosno da bude informisan o opasnostima u hrani, odrţavanju higijene radnog prostora i lične higijene, putevima kontaminacije, rukovanju hranom (uslovi čuvanja i rok odrţivosti), načinom pripreme hrane, kao i čuvanju pripremljene hrane (11). Znаčаj dobre prаkse pri pripremi hrane u domaćinstvima u vezi sa bolestima prenosivih hrаnom podrţаn je odgovarajućim epidemiološkim podаcimа. Nedavne epidemije bolesti prenosivih hranom i smrtni slučajevi u vezi sa komercijalnom pripremom hrane privukle su veliku paţnju medija i javnosti (12). Kao rezultat toga, potrošači pokazuju povećanu zabrinutost u vezi sa komercijalno pripremljenom hranom. MeĎutim, većina potrošača nije svesna da najmanje 60% slučajeva trovanja hranom nastaje usled pripreme hrane kod kuće, verujući da je uzrok takvih trovanja sam proizvoĎač hrane ili ishrana u restoranima (13). TakoĎe, istraţivanja su pokazala da su glavni faktori koji utiču na pojavu epidemija uzrokovanih trovanjem hranom uglavnom neodgovarajuće skladištenje, neadekvatno kuvanje ili podgrevanje i unakrsna kontaminacija. TakoĎe, ustanovljeno je da je uzrok u 25% prijavljenih epidemija bolesti izazvanih hranom neadekvatno rukovanje hranom od strane potrošača, kao i loša praksa pripreme hrane u domaćinstvima (14). Iаko je široko prihvаćena teorija od strаne stručnjаkа za hranu dа se mnogi slučаjevi bolesti prenosivih hranom jаvljаju kаo posledicа neprаvilnog rukovаnjа i pripreme hrane od strаne potrošаčа, sаmi potrošаči i dаlje nisu svesni ove činjenice (11). Dobra praksa u domaćinstvima zastupa sve higijenske principe i tehnike od kupovine namirnica za pripremu hrane kod kuće pa sve do utroška hrane pripremljene u domaćinstvu. Najčešći problemi koji se javljaju jesu pogrešno stečene i ustaljene porodične (lične) navike. U svim dobrim prаksama, osim u Dobroj praksi u domaćinstvima, nalaze se elementi HACCP sistema, koji čine HACCP sistem glаvnim sistemom u prаksi hrаne dаnаs. Dobra prаksа u domaćinstvima je i dаlje zаnemаrenа uprkos znаtnom broju bolesti prenosivih hranom koje se jаvljаju u toku pripreme hrаne u domaćinstvima. U klаsičnoj strаtegiji lаncа ishrаne sve relevаntne аktivnosti su preduzete u cilju dobrobiti čoveka, аli, izuzimajući ga izvаn sistemа, kаo potrošаčа (15). Potrošači moraju biti informisani na koji način nastaju unakrsne kontaminacije. Patogeni mikroorganizmi se kontinuirano unose u kućno okruţenje, naročito putem hrane, ljudi i kućnih ljubimaca. Pored toga, radne površine, naročito ruke i površine u kontaktu sa hranom, su glavni putevi prenosa patogena (16). Broj bakterija kao što su E. coli, Clostridium difficile i Schigella mogu da preţive mesecima na suvim površinama, i još duţe na vlaţnim površinama (17). U novije vreme sve je veće interesovanje potrošača vezano za dobre prakse u domaćinstvima. To je posledicа saznanja, odnosno svesti potrošača, dа postoji vezа izmeĎu kontаminirаnih površinа, prenosa i nastanka oboljenjа u kućnom okruţenju, kao što je npr. kuhinja. U kuhinjama je pronaĎen veliki broj pаtogenih bаkterijа, a odreĎena mesta su visoko kontаminirаna. Higijenska praksa u domaćinstvima, naročito korišćenje vlаţnih sunĎera, krpa, i dţogera mogu doprineti daljem širenju bаkterija nа radne površine ili direktno nа ruke, što dovodi do unаkrsne kontаminаcije bаkterijаmа i predstavlja potencijаlnu opasnost dа se bаkterije naĎu u nаmirnicаma. Značaj adekvatne prakse rukovanja hranom od strane potrošača je široko priznat. Sproveden je veliki broj istraţivanja u procesima proizvodnje, prerade i distribucije u prehrambenoj industriji. MeĎutim, potrošač je, i dalje, najmanje proučavana karika u lancu ishrane, a takoĎe, i informacije o potrošaču se smatraju u velikoj meri nepouzdanim. U domaćinstvima se priprema značajna količina hrane tako da su istraţivanja i edukacija potrošača u pogledu rizika usled nebezbedne prakse rukovanja hranom suštinski element za sprečavanje bolesti prenosivih hranom (18). Informacije o načinu rukovanja hranom u domaćinstvima dolaze iz dva glavna izvora: analize pojave epidemija trovanja hranom i istraţivanja zasnovana na proučavanju potrošača. Istraţivanja zasnovana na proučavanju potrošača sprovode se kako bi se procenila primena načina bezbednog rukovanja hranom od strane potrošača. Usvojeni su različiti pristupi istraţivanja, uključujući upitnike i intervjue, diskusije u ciljnim grupama, kao i opservaciona istraţivanja. Epidemiološke studije daju kvantitativne podatke o doprinosu nebezbednog rukovanja hranom koji rezultira pojavom slučajeva trovanja hranom. MeĎutim, retrospektivna analiza trovanja hranom daje ograničene informacije o ponašanju potrošača u vezi sa bezbednošću hrane. Tačnost i dostupnost podataka su ograničeni, jer je ljudima često teško da se prisete tačnih detalja u vezi sa potrošnjom hrane i praksom rukovanja hranom koji mogu imati velikog udela pri pojavi bolesti (19). Svrha ispitivanja potrošača je da se utvrdi koliki je udeo pojave bolesti prenosivih hranom usled nepravilnog rukovanja hranom u domaćinstvima i da se utvrdi šta potrošači znaju o bezbednosti hrane i zašto se neke prakse bezbednog rukovanja hranom primenjuju, a neke ne (20). Procene znanja potrošača, njegovih stavova i ponašanja mogu da obezbede osnovu za formulisanje propagandnih programa o zdravlju samih potrošača. Samo kada su potrošači upoznati sa praksom vezanom za bezbednost hrane, moguće je planirati efikasne strategije za podsticanje i jačanje poţeljnog ponašanja potrošača u vezi sa pripremom 14 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 11-16, --Vanredno izdanje-- hrane u domaćinstvima. Upotreba modela socijalnih saznanja za zdravstvene probleme je omogućila identifikaciju odnosa izmeĎu stavova, verovanja i ponašanja, kao i promena ponašanja (20). U sklаdu sа nаvedenim nаglаskom nа proizvodnju hrane, prerаdu i mаloprodаju, relаtivno mаlo istraţivanja izvršeno je u cilju ispitivanja znanja potrošača o bezbednosti hrаne, znаnjа i primeni dobrih praksi pri pripremi hrane u domaćinstvima. Potrebno je izvršiti istraţivanja kako bi se utvrdile prаznine u znаnju potrošаčа o bezbednosti hrаne i higijenskim greškama koje se nаjčešće jаvljаju u domаćim kuhinjаmа, kаko bi obrаzovni progrаmi mogli biti prilаgoĎeni tаko dа odgovore nа ovа pitаnjа. Većina istraţivanja o bezbednosti hrane protekle decenije obavljena su u Velikoj Britaniji i Severnoj Irskoj, kao i u Sjedinjenim Američkim Drţavama. Ankete (upitnici i intervjui), su najčešći način prikupljanja podataka, a korišćeni su u 75 % ispitivanja. TakoĎe su korišćene ciljne grupe, kao i opservaciona ispitivanja. Sakupljene su ograničene informacije o navikama potrošača i načinima u vezi sa bezbednim rukovanjem hranom. Postoji značajan broj informacija o znanju potrošača i samostalnom iskustvu pri pripremi hrane. Značajan broj potrošača često sprovodi nebezbednu praksu rukovanja hranom. Znanje, navike, načini i samostalna iskustva ne odgovaraju uočenom ponašanju, što ukazuje da su opservaciona ispitivanja bolji pokazatelj higijenskih uslova pri pripremi hrane u domaćinstvima. Poboljšanje načina rukovanja hranom u domaćinstvima bi trebalo da smanji rizik i učestalost pojave bolesti prenosivih hranom. Stalna su nastojanja za razvoj i implementaciju strategija o edukaciji potrošača vezanih za bezbednost hrane u cilju poboljšanja specifičnih ponašanja koja doprinose smanjenju učestalosti pojave bolesti prenosivih hranom (21). Mere bezbednosti potrošača imaju ključnu ulogu u prevenciji bolesti izazvanih hranom, jer one čine konačan korak u procesu pripremanja hrane. Bezbedno rukovanje hranom od strane potrošača u domaćinstvima smatra se ''poslednjom linijom odbrane '' (15). ZAKLJUČAK Globalna bezbednost hrane će biti ostvarena tek kada svaka karika u lancu ishrane u potpunosti (u unutrašnjoj i spoljašnjoj sredini) postane svoj gospodar u odreĎenoj oblasti. Na taj način biće osigurano da će aktivnosti koje prethode i slede u krugu bezbednosti hrane "od njive do trpeze", ne ignorišući potrošača, doprineti proizvodnji bezbedne hrane. Potrošač treba i dalje da bude svestan potencijalnih rizika, da pravilno rukuje i priprema hranu da bi osigurao svakodnevno bezbedan i uravnoteţen obrok. Potrebno je dodatno obrazovanje potrošača u pogledu bezbednosti hrane i oboljenja vezanih za hranu. TakoĎe, bilo bi korisno posvetiti više paţnje obrazovanju potrošača o manje poznatim patogenima. Ključnu ulogu imala bi edukacija potrošača javnim putem u oblasti bezbednosti hrane i njene pripreme. Razvoj novih tehnika i metoda će sigurno pomoći u smanjenju pojedinih opasnosti i odrţavanju kvaliteta ţivota. Napomena Ovaj rad je finansiran sredstvima projekta broj TR 31034 Ministarstva prosvete, nauke i tehnološkog razvoja Republike Srbije. LITERATURA Baltić, Ţ.M., D.Nedić, Jelena Đurić, Mirjana Dimitrijević, N. arabasil, Nataša Kilibarda: Hrana i večna briga za zdravlje, Veterinarski ţurnal Republike Srpske X (1) (2010) 5-9. Baltić, Ţ.M., Jelena Đurić, N. Karabasil, Mirjana Dimitrijević, Radmila Marković, Nataša Kilibarda: Tradicionalni proizvodi od mesa u duhu dobre proizvoĎačke prakse, Simpozijum tradicija i budućnost stočarstva u brdsko-planinskom području sa posebnim osvrtom na Sjeničko-peštersku visoravan, Zbornik radova Sjenica 23-25. jun 2010., str. 86-107. Bunčić, S.: Vodič za razvoj i primenu preduslovnih programa i principa HACCP u proizvodnji hrane, MPŠV, Uprava za veterinu, Beograd (2009). Baltić, Ţ.M.: Odgovornost za kvalitet namirnica, Tehnologija mesa, Beograd XIV(3) (1998) 138–147. 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Goutam: General outbreaks of infectious intestinal diseases linked with private residences in England and Wales 1992–9: questionnaire study. Br. Med. J. 323 (2001) 1097–1098. 15 M.Ţ. Baltić i sar.:POTROŠAČI I BEZBEDNOST HRANE Grunert, K.G.: Future trends and consumer lifestyles with regard to meat consumption. Meat Science, 74 (2006)149– 160. Baltić, Ţ.M., Jelena Đurić, N. Karabasil, Jelena Ivanović, Jasna Lončina: Food safety and quality at consumer level, Biological Food Safety and Quality, Belgrade, 4-5 Octobet 2012., pp. 49-51. Bielaszewska, Martina, A. Mellmann, W. Zhang, R. Köck, Angelika Fruth, А. Bauwens, G. Peters, Helge Karch: Characterisation of the Escherichia coli strain associated with an outbreak of haemolytic uraemic syndrome in Germany, 2011: a microbiological study, Lancet infect diseases, 11 (9) (2011) 671-676. Worsfold, D. and C. Griffith: Food safety behaviour in the home. British Food Journal, 93(3) (1997) 97–104. McCabe-Sellers, B.J. and S. Beattie: Food safety: Emerging trends in foodborne illness surveillance and prevention. Journal of the American Dietetic Association, 104(11) (2004) 1708-1717. Raspor, P.: Total food safe safety: how good practices can contribute? Trends in Food Science and Technology, 19 (2008) 405-412. Kramer, A., I. Schwebke, G. Kampf: How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infectious Diseases, 6 (2006) 130. Beumer, R., S.F. Bloomfield, M. Exner, G.M. Fara, J.N. Kumar, E. Scott: International scientific forum on home hygiene procedure in the home and their effectiveness: a review of the scientific evidence base (2002). Available at: http://www.ifh-homehygiene. org/2003/2public/IFHrecommends.pdf. Konecka-Matyjek, E., H. Turlejska, U. Pelzner and L. Szponar: Actual situation in the area of implementing quality assurance system GMP, GHP and HACCP in Polish food production and processing plants. Food Control, 16 (2005) 1–9. Marklinder, I.M., M. Lindblad, L.M. Eriksson, A.M. Finnson, R. iLindqvist, Home storage temperatures and consumer handling of refrigerated foods in Sweden. J. Food Prot., 67 (2004) 2570–2577. Tucker, M., S.R. Whaley and J.S. Sharp: Consumer perception of food-related risks. Int. J Food Sci. & Technol., 41 (2006) 135–146. Redmond, E.C.: Food handling risks in the home: development, application and evaluation of social marketing food safety education initiative. Ph.D. thesis. University of Wales, Cardiff, UK (2002). CONSUMERS AND FOOD SAFETY Baltić Ţ. Milan1, Đurić Jelena1, Mandić Snjeţana2, Pećanac Biljana3, Lončina Jasna1 Belgrade University, Faculty of Veterinary Medicine, Srbija, http://www.vet.bg.ac.rs/ 2 University of Banja Luka, Faculty of Technology, Republic of Srpska, Bosnia and Herzegovina, http://www.tfbl.org 3 JU Veterinary institute of Republic of Srpska "Dr Vaso Butozan" Banja Luka, Republika Srpska, Bosnia and Herzegovina, http://www.virsvb.com 1 Today, food safety and quality have a key role in maintaining the health of consumers, as the ultimate link in the food chain. Foodborne diseases represent a problem to every individual, but are particularly important for children, the elderly and immunocompromised individuals. Although it has been widely accepted by food experts that many cases of foodborne diseases occur as a result of improper food handling and preparation by consumers, the consumers themselves are still not aware of this fact. Personal hygiene is a well known way by means of which people can reduce the risk of these diseases. However, little is known of actual implementation of personal hygiene and sanitation behaviors at home. The task of many studies is to assess the knowledge of consumers in relation to food safety and to determine whether that knowledge is in accordance with the applied practice. Such information can be of great help to professionals who deal with education of consumers about food safety, with the aim of making consumers become aware of their critical role in reducing the risk of foodborne diseases. Key words: consumers, risk, food safety 16 PANEL SESSIONS LECTURES SEKCIJSKA PREDAVANJA 17 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 19-23, -Vanredno izdanje- CHEMICAL PROCESSES IN PRINTING TECHNOLOGY Miroslav Gojo, Tomislav Cigula University of Zagreb, Faculty of Graphic Arts, Zagreb, Getaldiceva 2, Republic of Croatia 1 ISSN 2232-755X DOI: 10.7251/GHTE13VI019G UDC 543:66.017/.018 One of the most commonly used printing technique today is lithography. The printing plate, which is composed of printing (accept printing ink) and nonprinting (must not accept printing ink) areas is a highly important factor for all printing processes. Selective ink adsorption on printing plates is usually achieved by geometrical difference between printing and nonprinting areas, but in lithography it is achieved by their different physical-chemical properties. Printing areas are oleophilic (hydrophobic) while nonprinting areas are hydrophilic (oleophobic). In the first step of the printing process, on the printing plate comes fountain solution (water and additives), which is adsorbed only by the nonprinting areas. Printing ink is applied in the second step and it is adsorbed only by the nonprinting areas (not covered with fountain solution). The printing plates are mainly built of aluminium strips that are mechanically, chemically and electrochemically processed in order to make thin and porous film of aluminium oxide (nonprinting areas) and then coated with photoactive layer (printing areas). The plate making process is by aluminium printing plates, composed of exposure and developing which remove photoactive layer from nonprinting areas. The aim of this paper is to present the plate making processes and plate parameters’ measuring methods, for example contact angle measurement, determination of the roughness parameters and electrochemical impedance spectroscopy (EIS). In addition, as printing plate-fountain solution interaction is influential for the printing quality, one should define fountain solution’s optimal chemical composition, for which measurements of pH value, electrical conductivity and surface tension are needed. Keywords: Graphic technology, printing plate, physical-chemical processes, offset printing INTRODUCTION Offset printing is the main representative of lithography. It is characterised by two main features, first the difference between printing and nonprinting areas on the printing plate is achieved by their opposite physical-chemical properties. The printing areas are oleophilic (hydrophobic), while nonprinting areas are hydrophilic (oleophobic). Secondly, the printing ink is from the printing plate to the printing substrate transferred by offset cylinder [1]. These facts make offset printing a very complex process where all production parameters must be set in a narrow interval in order to make imprints of high quality. In the printing process the printing plate is first covered with fountain solution (water with additives), which is adsorbed only by hydrophilic surfaces – the nonprinting areas. The surface then comes into a contact with the inking rollers. The printing ink is adsorbed on surface which is not covered with fountain solution – the printing areas. The printing ink and the fountain solution are transferred from the printing plate to the offset cylinder and from there to the printing substrate which comes between offset and printing cylinder as presented in Figure 1 [1]. As printing substrates are usually papers and paperboards one should use fountain solution as little as possible, in order to avoid deterioration of the substrate’s mechanical properties. Figure 1. Offset printing unit Korespodentni autor: Miroslav Gojo, University of Zagreb, Faculty of Graphic Arts, Zagreb, Getaldiceva 2, Republic of Croatia, e-mail: mgojo@grf.hr 19 M.Gojo i T. Cigula: KEMIJSKI PROCESI U GRAFIČKOJ INDUSTRIJI MATERIALS The printing plates are mainly made of aluminium foils which have to be processed in order to enrich them with needed surface properties. The processing of the aluminium foils usually consists of several steps: cleaning/degreasing, roughening, anodic oxidation, finishing, coating with photoactive layer and in the end cutting to wanted dimension. Roughening of the aluminium surface and forming of thin aluminium oxide film are necessary for a number of reasons: it enlarges the functional properties of the surface and causes better fountain solution adsorption, better adsorption of the photosensitive coating, causes better ink adhesion, during the reproduction process it increases stability of the fountain solution and printing ink on the nonprinting and printing surfaces, respectively. It ensures better mechanical properties of the printing plates and thus, longer print runs with the plates [2]. The functional properties of the printing plate are highly influenced by the surface structure and its characteristics, making the topography characterization very important for many applications since the roughness of the surface is a significant engineering factor (Figure 2) [3]. Post anodic treatments differ between manufacturers, but generally serve to improve the hydrophilic properties of non-printing areas [4, 5]. Photoactive coating enables image transfer on the printing plate by changing its solubility when irradiated by defined electromagnetic irradiation. Figure 2. Micrograph of the aluminium foil’s surface after roughening and anodic oxidation Besides the printing plate, for a stable printing process one should also take into account the interaction between nonprinting areas and the fountain solution as complete coverage of the nonprinting areas with a thin film of the fountain solution is essential in achieving high printing quality. Besides its main role (covering completely nonprinting areas), fountain solution also has to improve cleaning the printing plate of printing ink, ensure fast and complete spreading on the printing plate surface in a thin film, decrease friction between printing plate and rubber blanket, emulsify in wanted portion with printing ink. Therefore, fountain solution must be precisely composed of water and additives which will enhance its performances [6]. PLATE MAKING PROCESS After preparing aluminium foil to have needed surface characteristics in order to build nonprinting areas (thin and porous aluminium oxide layer) and printing areas (photoactive coating) one should transfer the image on the printing plate and make it ready for printing. The plate making process usually consists of two major steps, exposure and developing. In exposure, the coated aluminium foil is irradiated with defined light source which irradiates wave lengths compatible with the sensitivity of the photoactive coating. The goal of the exposure is to cause certain chemical changes in the photoactive layer which will make it soluble (positive working photoactive layers) or insoluble (negative working photoactive layers) in a defined solvent. Older plate making systems used a positive or negative film as a mask which enabled only some parts of the photoactive coating to be irradiated. This plate making system is still present in today’s plate making systems, but not so often in the plate making process for lithography, then for 20 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 19-23, -Vanredno izdanjeflexography. In lithography the exposure of the plates is mostly conducted in a platesetter which uses laser as a light source. The wanted areas of the photoactive layer are directly irradiated with a laser beam. One could there distinguish two groups of photoactive layers, heat-mode layers, which are sensitive to infra-red (IR) irradiation and photo-mode layers, which are sensitive to the visible light irradiation. Developing process is present in almost all plate making processes. The role of developing is to remove soluble parts of the photoactive layer after exposure. Majority of the photoactive layers use a highly alkaline solution as the developer. This fact makes it very important to conduct developing in strict conditions as after dissolving photoactive layer, developer could impair surface of the aluminium oxide as it is soluble in base and acid solutions [7]. MEASURING METHODS IN CONTROL OF THE PLATE MAKING PROCESS As previously mentioned, the plate making process is very complex and one must optimize this process in order to get the high quality result, which significantly influences the quality of the final product. The most used methods in characterisation of the printing plate’s surface properties, which have direct influence on the printing process, are measurement of the contact angle, calculation of the surface energy and its components, determination of the roughness parameters, electrical impedance spectroscopy (EIS) and optical and scanning electron microscopy. Measurement of the contact angle is a method based on the fact than one could determine wetting characteristics of a solid surface by examination of the liquid drop on a solid or liquid (if these two do not mix) surface. The contact angle is defined as the angle between two tangents in a point where all three phases (vapour, solid and liquid) come in contact, one is tangent on the liquid drop and the other is tangent on the solid surface (Figure 3) [8]. Figure 3. Contact angle determination Contact angle is described in Young equation: lv cos sv sl (1) where γlv is interfacial energy liquid-vapour, γsv is interfacial energy solid-vapour, γsl is interfacial energy solid-liquid and Θ is the contact angle. The contact angle of the printing plate could give information about the printing plate making process, for example duration of the exposure, duration and composure of the developer solution, influence of the printing process on the printing plate’s surface etc. [9, 10]. Surface energy and its components can be calculated by measuring contact angles of referent liquids on the investigated solid surface. In the printing plate investigation one could use the Owens-Wendt-Rabel and Kaelble (OWRK) analysis method. This method is developed from Young equation and the fact that surface tension can be divided on the polar and dispersive part [11, 12]. (2) where σs is surface tension of the solid, σl is the surface tension of the liquid, σD dispersive part of surface tension, σP polar phase of surface tension [12]. As fountain solution (water based) must have good spreading on the nonprinting areas, it is of higher interest to see behaviour of the polar component of the surface energy when changes in the printing plate making process occurs [13]. Electrical impedance spectroscopy is an electrochemical analytical method suitable for measurement of nonconductive layers on a conductive base, such as varnishes, colour on a metal surface, metal oxides etc. [14]. Electrical impedance is a resistance in an AC electrical circuit. The electrical impedance is sum of real and imaginary part (3). 21 M.Gojo i T. Cigula: KEMIJSKI PROCESI U GRAFIČKOJ INDUSTRIJI Z* = Z' – jZ'' (3) where Z* is the electrical impedance, Z' is real part of the electrical impedance Z'' is imaginary part of the electrical impedance and j = 1 [15]. Measuring electrical impedance while changing the frequency of the voltage source one could determine changes on the printing plate surface as the formed aluminium oxide layer and the aluminium base create a double layer which could be simulated by an electrical circuit [16]. The parameters of the circuit elements imply the change of the aluminium oxide surface [17 - 19]. CONTROL OF THE FOUNTAIN SOLUTION CHARACTERISTICS The printing plate-fountain solution interaction has a very important role in the printing process. One must define properties of the fountain solution to determine its optimal composition. On the other hand, fountain solution could get contaminated in a printing process, and therefore must be constantly observed and if needed corrected with additives to keep its function in a wanted boundaries. The parameters which are usually measured during printing process are pH value and electrical conductivity. pH value must be between 4.5 and 5.5 as this is interval in which aluminium oxide is stable [7], but also this value leads to the better drying of the printing ink. The electrical conductivity value is not defined as it depends on the various fountain solution compositions, but it is a parameter which gives signal if some particles of paper, varnish etc. have mixed with fountain solution and could cause problems in the wetting process. CONCLUSION This paper presents an overview of some chemical processes and measuring methods which are used in graphic industry connected with the printing plate processing. One could see that the plate making process is full of chemical processing. Because of their bad ecological impact, investigations are made to develop processes with lower use of chemicals, but for now they are not keeping up with the needed quality level or durability. Therefore, another way of improving these processes and lowering negative ecological impact is by defining more precisely energy and chemical consumption by optimized current processes. Usage of precise measuring methods which enable greater precision in characterization of the materials and definition of their properties in relation to the chemical processing must be included in that process. REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 22 Wilson, D. G., (2005), Lithography primer, Pittsburg: GATFPress Brinkman, H.J., Kernig, B. (2003) Aluminium for lithographic applications // ATB Metallurgie R&D Hydro Aluminium. 43(1-2), pp. 130-135 Dimogerontakis, Th., Van Gils, S., Ottevaere, H., Thienpont H., Terryn, H. (2006) Quantitative topography characterisation of surfaces with asymmetric roughness induced by AC-graining on aluminium // Surface Coating Technology. 201, pp. 918-926. Lin, C.S., Chang C.C., Fu, H.M. (2001) AC electrograining of aluminum plate in hydrochloric acid // Materials Chemistry and Physics 68 pp. 217-224. Urano, T., Kohori, K., Okamoto, H. Photosensitive Lithographic Printing Plate and Method for making a Printing Plate, Patent No.: US 6,689,537 B2, 2004. Kipphan, H., (2001), Handbook of Print Media, Berlin: Springer. Pourbaix, M., (1966), Atlas of Electrochemical Equilibria in Aqueous Solutions, Oxford, London, Paris, Toronto, New York, Frankfurt: Pergamon Press. Atkins, P. W., (1998), Physical Chemistry, 6th Ed., Oxford University Press Baracic, M., Cigula, T., Tomasegovic, T., Zitinski Elias, P. Y., Gojo, M., (2009), Influence of plate making process and developing solutions on the nonprinting areas of offset printing plates, Proceedigs of the 20th DAAAAM Symposium "Inteligent Manifacturing & Automation : Focus on Theory, Practice and Education", ed. Katalinić, Branko, Viena : DAAAAM International. Mahovic Poljacek, S., Cigula, T., Pintar, N., Gojo, M., (2010), Quality of the Printing Plates as a Function of Chemical Processing, Annals of DAAAM for 2010 & Proceedings of the 21st International DAAAAM Symposium "Inteligent Manifacturing & Automation: Focus on Interdisciplinary Solutions", ed. Katalinic, Branko, Viena : DAAAM International. Owens, D.K., Wendt, R.C. (1969) Estimation of the surface free energy of polymers // Journal of Applied Polymer Science, v.13., pp. 1741-1747 Van Oss, C. J.; Giese, R. F.; Li, Z.; Murphy, K.; Norris, J.; Chaudhury, M. K., Good, R. J. (1993) Contact Angle, Wettability and Adhesion, K. L. Mittal (Ed.), VSP, Utrecht, The Netherlands. Cigula T. (2011), Kvalitativna analiza slobonih površina tiskovnih formi, PhD thesis, Grafički fakultet, zagreb Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 19-23, -Vanredno izdanje14. Mansfeld, F., (1999), Analysis and Interpretation of EIS Dana for Metals and Alloys, Technical report 26, Solartron Limited. 15. Monk, P., (2005), Fundamentals of electroanalytical electrochemistry, Chichester: John Wiley&sons Ltd. 16. FOGRA Project No. 22.024, Electrochemische Untersuchungen def Oberfläche von Offsetdruckplatten zur Aufklärung der Ursachen von Farbannahmeerscheinungen an bildfreien Stellen, Report 2006. 17. Cigula, T., Fuchs-Godec, R., Gojo, M., Slemnik, M. (2012) Electrochemical Impedance Spectroscopy as a tool in the plate making process optimization // Acta Chimica Slovenica 59 3, pp. 513-519 18. Hitzig, J., Jüttner, K., Lorenz, W. J., Paatsch, W., (1984) AC-Impedance Measurements on Corroded Porous Aluminum Oxide Films, Corrosion Science, 24 (11/12), pp. 945-952. 19. Risovic, D., Mahovic Poljacek, S. Gojo, M., (2009) On correlation between fractal dimension and profilometric parameters in characterization of surface topographies, Applied Surface Science, 255 (7); pp. 4283-4288. KEMIJSKI PROCESI U GRAFIČKOJ TEHNOLOGIJI Miroslav Gojo1, Tomislav Cigula Sveučilište u Zagrebu, Grafički fakultet, Zagreb, Getaldićeva 2, Republika Hrvatska Jedna od najzastupljenijih tehnika otiskivanja u suvremenom tisku je tehnika plošnog tiska. Osnova za sve tehnike tiska je tiskovna forma koja se sastoji od tiskovnih (prihvaćaju bojilo) i slobodnih površina (ne smije prihvatiti bojilo). Na većini tiskovnih formi je selektivno prihvaćanje bojila postignuto geometrijskom razlikom, no u plošnom tisku se tiskovne i slobodne površine razlikuju po svojim fizikalno kemijskim svojstvima, odnosno hidrofilnosti i oleofilnosti kao površinskim pojavama. Tiskovne površine moraju biti izrazito oleofilne (hidrofobne), dok slobodne površine moraju imati izrazito hidrofilna (oleofobna) svojstva. U procesu tiska se prvo nanosi otopina za vlaţenje (voda s dodatcima) te se prihvaća samo na slobodne površine. U sljedećem koraku se nanosi bojilo s uljnim otapalima te se ono prihvaća samo na površine koje nisu prekrivene otopinom za vlaţenje (tiskovne površine). Aluminijski lim od kojeg se najčešće izraĎuje tiskovna forma, mora se površinski obraditi mehaničkim, kemijskim i elektrokemijskim postupcima kako bi se na njoj dobila tanka, porozna prevlaka aluminijevog oksida (slobodne površine) koja se na kraju oslojava fotoaktivnim slojem (tiskovne površine). Izrada takve tiskovne forme se sastoji od osvjetljavanja i razvijanja, čime se sa slobodnih površina uklanja fotoaktivni sloj. Cilj rada je prezentirati kemijske procese izrade ofsetnih tiskovnih formi, te primjena različitih metoda kojima se pratite i optimiziraju ti procesi: mjerenja kuta kvašenja, parametara hrapavosti i elektrokemijske impedancijske spektroskopije (EIS). Nadalje, kako je za proces tiska od izuzetne vaţnosti interakcija otopine za vlaţenje koja se koristi i tiskovne forme, potrebno je odrediti njen optimalni kemijski sastav prateći pH vrijednost, električnu provodljivost, te napetost površine. KLJUČNE RIJEČI: Grafička tehnologija, tiskovna forma, fizikalno-kemijski procesi, ofsetni tisak 23 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 25- 36 , -Vanredno izdanje- ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Elvis Ahmetović1,3, Nidret Ibrić1, Zdravko Kravanja2 Univerzitet u Tuzli, Tehnološki fakultet, Tuzla, Bosna i Hercegovina 2 Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo, Maribor, Slovenija 1 ISSN 2232-755X DOI: 10.7251/GHTE13VI025A UDC 628.3:005.642.2 Voda i energija su značajni prirodni resursi koji se obično koriste u velikim količinama u procesnoj industriji. U zadnje dvije decenije su predloţeni i implementirani različiti pristupi u cilju minimizacije korištenja svjeţe vode, generisanja otpadne vode i potrošnje energije. Ranije studije su se odnosile na istraţivanje različitih strategija za minimizaciju svjeţe i otpadne vode u izotermskim mreţama vode (ponovno korištenje vode, prečišćavanje otpadne vode i njeno recikliranje), ali u skorašnjim pristupima je razmatrana i minimizacija energije zajedno sa minimizacijom svjeţe i otpadne vode. U ovom radu je predstavljena optimizacija superstrukture kao jedna od metoda za simultanu sintezu ukupnih mreţa vode, otpadne vode, i energije. U cilju ilustriranja primjenjivosti predloţenog pristupa korišten je literaturni primjer. Prvo je prezentiran osnovni slučaj problema sinteze mreţe vode. Nakon toga sintetizirane su mreţe vode korištenjem simultane optimizacije. Dobijeni rezultati su isti ili bolji od rezultata publiciranih u literaturi. Predstavljena je optimalna neizotermska mreţa vode, koja ima optimalnu potrošnju svjeţe vode, nastajanje otpadne vode, potrošnju energije i investicije, za slučaj kada su tokovi izmeĎu procesnih jedinica uzeti u obzir za integraciju topline. Ključne riječi: odrţiva industrija, integracija vode, integracija energije, simultana sinteza, optimizacija superstrukture. 1. UVOD Globalna potrošnja svjeţe vode i energije u svijetu je u stalnom porastu i taj trend će se najvjerovatnije nastaviti i u budućnosti. U generalnom se moţe reći da je prosječna globalna potrošnja svjeţe vode u poljoprivredi 70%, industriji 20% dok se za potrebe stanovništva koristi oko 10% vode (1). Navedena raspodjela moţe da bude raznolika u zavisnosti od toga da li se radi o razvijenim zemljama ili zemljama u razvoju. Tako npr. u industrijski razvijenim zemljama (Kanada, Njemačka, Francuska, Amerika) industrijska potrošnja vode je znatno veća (46-80%) dok je u tim zemljama potrošnja vode za potrebe poljoprivrede znatno manja (8-42%). Industrijski sektor učestvuje u ukupnoj potrošnji energije u svijetu sa oko 51% (2). Pored velike potrošnje vode i energije u industrijskom sektoru (hemijska, prehrambena, petrohemijska, farmaceutska industrija, industrija proizvodnje papira, itd.) se generišu i velike količine otpadnih tokova koji se iz procesa ispuštaju u okolinu. U prošlosti procesna industrija je bila usmjerena uglavnom samo na povećanje profita. U zadnje vrijeme zbog uvoĎenja okolišnih regulativa i strogih ograničenja na ispuštanje otpadnih tokova iz industrijskih procesa u okolinu, procesna industrija pored profitabilnosti mora zadovoljavati i načela odrţivosti procesa (3-5). U skladu s navedenim, studije odrţivog upravljanja vodom, otpadnom vodom i energijom u industriji predstavljale su aktuelni istraţivački problem u zadnjih par decenija i jedan su od glavnih fokusa istraţivanja u narednom periodu (3-10). Cilj tih istraţivanja je bio minimizirati potrošnju svjeţe vode i energije (topline) u industrijskim procesima kao i količinu otpadnih tokova koji se iz procesa ispuštaju u okolinu. Ta istraţivanja spadaju u oblast procesne sinteze (sinteze procesa) i procesne integracije (integracije procesa) koja predstavlja jednu od ključnih oblasti procesnog sistemskog inţenjerstva (PSE). Cilj procesne sinteze i procesne integracije je istraţiti cijeli proces i razviti strategije za integraciju mase i energije pri čemu se minimiziraju ukupni troškovi kao i nastajanje otpadnih tokova koji ispuštaju u okolinu. Za postizanje navedenog cilja mogu se koristiti sistemske metode kao što su pinch tehnologija i matematičko programiranje. Pinch tehnologija se prvo primjenjivala za integraciju topline (7) a nakon toga za integraciju vode (3-5). U generalnom ona se sastoji od dvije faze. Kod integracije topline, u prvoj fazi se vrši odreĎivanje minimalne potrošnje energenata (ogrijevne pare i rashladne vode) prije detaljnog dizajna. Ta procedura je poznata pod terminom "targeting". U drugoj fazi se dizajnira mreţa izmjenjivača topline za utvrĎenu minimalnu potrošnju energenata utvrĎenu u prvoj fazi. Kod integracije vode pinch tehnologija se prvo primjenjivala za sintezu mreţe vode koja se sastoji od procesa u kojima se koristi voda a glavni cilj je bio odrediti minimalnu potrošnju svjeţe vode i minimalnu količinu nastale otpadne vode prije detaljnog dizajna mreţe vode. Nakon utvrĎivanja minimalne potrošnje vode i minimalnog generisanja otpadne vode izvršena je sinteza i dizajn mreţe vode. Metoda matematičkog programiranja se bazira na optimizaciji superstrukture (11). U generalnom superstrukturna metoda se sastoji od tri koraka. U prvom koraku se vrši razvoj svih fizički mogućih alternativa koje se inkorporiraju u 3 Korespodentni autor: Elvis Ahmetović, Univerzitet u Tuzli, Tehnološki fakultet, Univerzitetska 8, 75000 Tuzla, Bosna i Hercegovina. Tel.: +387 35 320756; Faks: +387 35 320741, e-mail: elvis.ahmetovic@untz.ba. 25 E. Ahmetović i sar.: ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI superstrukturu. Ovdje je bitno naglasiti da ukoliko se neke konfiguracije procesnih alternativa ne inkorporiraju u superstrukturu kao rezultat se moţe imati rješenje koje nije optimalno. U drugom koraku se vrši formulacija optimizacijskog modela na osnovu sintetizirane superstrukture. Model se sastoji od funkcije cilja i ograničenja. Funkcija cilja npr. moţe da predstavlja maksimizaciju profita ili minimizaciju ukupnih troškova. Ograničenja mogu da budu tipa jednakosti i nejednakosti. Pri formulaciji modela koriste se cjelobrojne (obično binarne 0-1 variable) i kontinuirane varijable. Cjelobrojne varijable omogućavaju odabir procesnih alternativa. Tako npr. ukoliko je odabrana vrijednost binarne varijable jedan tada je odabrana procesna alternativa, a ukoliko je njena vrijednost nula tada procesna alternativa nije odabrana u rješenju. Kontinuirane varijable sluţe za odreĎivanje vrijednosti procesnih parametara (protoci, koncentracije, temperature, itd.). U slučaju da je problem nelinearan i da sadrţi diskretne i kontinuirane varijable tada se model formuliše kao problem miješanog cjelobrojnog nelinearnog programiranja (MINLP). U trećem koraku se vrši rješavanje optimizacijskog modela u cilju pronalaţenja optimalnog rješenja sa stanovišta procesne konfiguracije i procesnih parametara. Cilj ovog rada je predstaviti osnove korištenja vode u procesnoj industriji, koncept sinteze mreţa vode, otpadne vode i energije u procesu i na primjeru primjeniti metodu matematičkog programiranja u cilju minimizacije potrošnje svjeţe vode, otpadne vode i energije. 2. KORIŠTENJE VODE I ENERGIJE U PROCESU Na slici 1 je predstavljen opšti prikaz korištenja vode u procesu (12, 13). Sirova voda se prije uvoĎenja u proces obično prečišćava u sistemu za tretman vode. Nakon toga, svjeţa voda se moţe koristiti u procesu kao procesna voda (za operacije pripreme/pranja sirovina, separacije, apsorpcije, ekstrakcije, itd.), voda za generisanje energenata (ogrijevna para, električna energija) i voda za hlaĎenje (rashladna voda) ili pak za druge namjene. Nakon korištenja vode u procesu nastaje otpadna voda, koja se obično prečišćava u sistemu za tretman otpadne vode prije ispuštanja u okolinu. S obzirom da skoro svaki proces ima potrebu za energijom (ogrijevna para, električna energija) ili rashladnom vodom onda je on u direktnoj vezi sa sistemom za generisanje energije i sa sistemom recirkulacije rashladne vode. Ukoliko su upotrebe svjeţe vode, ogrijevne pare i rashladne vode u procesu veće od minimalnih potreba tada se ima i veća ukupna potrošnja vode u procesu i veća ukupna količina otpadne vode koja se ispušta u okolinu. U tom slučaju će biti i veća potrošnja goriva u sistemu za generisanje energije, te takoĎer električne energije potrebne za transport vode u ukupnom sistemu. Na taj način potrošnja prirodnih resursa (npr. vode, goriva za generisanje energije, ogrijevne pare i električne energije, iz vode) potrebnih za funkcionisanje procesa je veća. TakoĎer, veća je i količina otpadnih tokova (npr. otpadna voda, isparena voda u rashladnim tornjevima sistema za recirkulciju rashladne vode, otpadni plinovi, itd.) koji se iz procesa ispuštaju u okolinu. Takav slučaj funkcionisanja procesa nije ekonomičan a takoĎer ni ekološko odrţiv. 26 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 25- 36 , -Vanredno izdanje- Slika 1. Tipično korištenje vode u hemijskoj procesnoj industriji (12, 13). Figure 1. Typical water uses in the chemical process industries (12, 13). U cilju postizanja ekonomsko efikasnih i ekološko odrţivih procesa potrebno je smanjiti potrošnju prirodnih resursa potrebnih za funkcionisanje procesa kao i količinu otpadnih tokova koji se iz procesa ispuštaju u okolinu što predstavlja osnovni koncept procesne integracije (14). Potrebe procesa za procesnom vodom, energijom (npr. ogrijevna para, električna energije) i rashladnom vodom će biti manje ukoliko se ima integracija vode i energije u procesnom sistemu. Cilj integracije vode je smanjiti potrošnju svjeţe vode i generisane otpadne vode a cilj integracije energije je smanjiti potrošnju energije (topline) u procesu. Integracija vode u mreţi komponovanoj od procesnih i regeneracijskih (tretman) jedinica se moţe postići ukoliko se ima ponovno korištenje vode, regeneracija i ponovno korištenje vode, regeneracija i recirkulacija vode (slika 2). TakoĎer, izmjenama opreme u procesu moţe se smanjiti potreba procesa za vodom. Na primjer, rashladni tornjevi koji koriste vodu mogu se zamijenjeni sa hladnjacima koji koriste zrak, ili u slučaju procesa pranja moţe se povećati broj stepeni (10, 15). Svjeţa voda se koristi u procesnim operacijama u kojima se na tok vode prenosi maseno opterećenje kontaminanata i nastala otpadna voda se ispušta iz procesnih operacija (slika 2a). Otpadni tok vode iz jedne procesne operacije se moţe ponovo koristiti u drugim procesnim operacijama (slika 2b) ukoliko je sadrţaj kontaminanata u toku manji od maksimalnog dozvoljenog sadrţaja kontaminanata na ulazu u druge procesne operacije ( ponovno korištenje vode). 27 E. Ahmetović i sar.: ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Slika 2. Ponovno korištenje vode, regeneracija i ponovno korištenje i regeneracija i recikliranje vode (13). Figure 2. Water reuse, regeneration and water reuse, regeneration and water recycling (13). TakoĎer tok otpadne vode iz jedne procesne operacije moţe se miješati sa tokom otpadne vode iz druge operacije i/ili sa tokom svjeţe vode. Pod ponovnim korištenjem vode se podrazumijeva da se tok vode iz jedne procesne jedinice moţe usmjeriti prema ostalim procesnim operacijama. U slučaju kada se tok vode iz jedne procesne operacije uvodi u istu procesnu operaciju tada se ima lokalna recirkulacija vode oko procesne jednice. Lokalna recirkulacija moţe smanjiti ukupnu potrošnju vode. MeĎutim, u nekim slučajevima uslijed lokalne recirkulacije vode moţe se imati nagomilavanje kontaminanata u procesu pa je u tom slučaju ona nepoţeljna. Otpadni tokovi vode iz procesnih jedinica se obično usmjeravaju u sistem regeneracije (tretman jedinice) u kome se vrši regeneracija otpadne vode odnosno djelimično uklanjanje kontaminanata. Nakon toga se prečišćena voda moţe ponovo koristiti u procesu (slika 2c), ali ne u procesnim operacijama u kojima je bila prethodno korištena ( regeneracija i ponovno korištenje vode). Pored navedenog regenerirana voda, iz koje su uklonjeni kontaminanti, moţe se reciklirati i koristiti (slika 2d) u svim procesnim operacijama (regeneracija i recikliranje vode). Navedeni slučajevi predstavljaju osnovne načine minimizacije svjeţe i otpadne vode koji se koriste pri sintezi mreţa vode u procesima. Integracija energije (topline) u procesu se moţe postići ukoliko se topli i hladni tokovi integriraju u mreţi izmjenjivača topline (7) tako da samo ukoliko se ne mogu postići ciljne temperature tih tokova vrši se dodatno grijanje sa ogrijevnom parom i hlaĎenje sa rashladnom vodom. U skladu s navedenim, u narednom dijelu su predstavljene osnove koncepta sinteze mreţa vode, otpadne vode i energije. 3. SINTEZA MREŢA VODE, OTPADNE VODE I ENERGIJE Jedan od osnovnih ciljeva procesne sinteze i procesne integracije predstavlja smanjivanje potrošnje svjeţe vode, nastajanja otpadne vode i potrošnje energije u procesu. U skladu s navedenim, neke od značajnih oblasti procesne sinteze su sinteza mreţe izmjenjivača topline (7), sinteza mreţa vode i otpadne vode (3-6, 16) odnosno sinteza kombinovanih mreţa izmjenjivača topline i mreţa vode (2, 17-23). Jedan od ciljeva ovog rada je istaknuti značaj navedenih mreţa u sintezi i dizajniranju ekološko odrţivih industrijskih procesa. Počeci intenzivnijih istraţivanja u oblasti sinteze mreţe izmjenjivača topline i integracije topline su vezani za porast cijene energije a datiraju iz 1970 i 80-tih godina (24-32). Navedena istraţivanja su još uvijek popularna jer se 28 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 25- 36 , -Vanredno izdanjeintegracijom topline smanjuje potreba za pogonskim sredstvima (ogrijevna para, rashladna voda) u procesu i zadovoljava princip odrţivosti procesa. Mreţa izmjenjivača topline se sastoji od izmjenjivača topline, grijača i hladnjaka te njihovih meĎusobnih konekcija. U mreţu izmjenjivača topline se uvode topli i hladni procesni tokovi i pogonska sredstva (energenti). Cilj sinteze je dizajnirati mreţu izmjenjivača topline u kojoj se ima maksimalna rekuperacija topline, koja se ostvaruje integracijom topline izmeĎu toplih i hladnih tokova. U slučaju da se na taj način ne mogu dostići ciljne temperature toplih odnosno hladnih tokova vrši se dodatno hlaĎenje ili grijanje tokova sa energentima (rashladna voda, ogrijevna para). Detaljan prikaz publiciranih radova u vezi sinteze mreţe izmjenjivača topline je raspoloţiv u preglednom radu (7). Pored istraţivačkih studija u oblasti minimiziranja potrošnje topline i sinteze mreţe izmjenjivača topline u procesima, fokus istraţivača je bio usmjeren i na minimiziranje potrošnje svjeţe vode koja se koristi u procesu, minimiziranju količine otpadne vode koja se iz procesa ispušta u okolinu, te dizajniranju sistema mreţe vode i otpadne vode. Prve studije i novi sistemski pristupi u toj oblasti datiraju iz početka 1980-tih godina (33) dok veći interes u ovoj oblasti se javlja sredinom 1990-tih godina (10, 15). U tim studijama razmatrane su opcije ponovnog korištenja vode, regeneracije i ponovnog korištenja vode, regeneracije i recikliranja vode, te uvoĎenja izmjena u procesu koje bi kao rezultat imale smanjenje potrošnje vode i nastajanja otpadne vode. U početku istraţivanja su prvo separatno studirane mreţe vode (mreţe procesnih jednica u kojima se koristi voda) i mreţe otpadne vode (mreţe tretman jedinica u kojima se prečišćava otpadna voda). Nakon toga su mreţe procesnih i tretman jedinica integrirane u jednu integralnu mreţu i problem minimizacije svjeţe vode i otpadne vode je riješen za integralnu mreţu. Takav integralni pristup je omogućio pronalaţenje boljih rješenja u odnosu na sekvencijsko rješavanje problema mreţe vode i mreţe otpadne vode. Navedena istraţivanja su još uvijek aktuelna i veliki broj radova je publiciran u ovoj oblasti. S obzirom da u procesu postoje uzajamne interakcije izmeĎu potrošnje energije i vode, daljnja istraţivanja su bila usmjerena na studiranje veza izmeĎu vode i energije u procesu jer je na takav način moguće istovremeno smanjiti potrošnju vode i potrošnju energije u procesu. Prva studija u toj oblasti datira iz 1998. godine (34). U tim istraţivanjima mreţa vode (mreţa procesnih jedinica u kojima se koristi voda) je studirana sa mreţom izmjenjivača topline. Ta istraţivanja su postala jako aktuelna u periodu nakon 1998. godine (2, 4, 6, 17-23, 35-55). Za sintezu kombinovanih mreţa vode i izmjenjivača topline korištene su sistemske metode (pinch tehnologija i matematičko programiranje) i sekvencijske i simultane strategije rješavanja problema sinteze ukupne mreţe. Pri sekvencijskoj strategiji rješavanja ukupnog problema prvo je riješena mreţa vode a nakon toga mreţa izmjenjivača topline, dok su u simultanoj strategiji obije mreţe rješavane istovremeno. Prednost sekvencijske strategije je u hijerarhijskoj dekompoziciji ukupnog problema sinteze na manje probleme, koje je jednostavnije riješiti, a nedostatak što najbolji kompromis izmeĎu potrošnje vode, potrošnje energije i investicija se ne moţe utvrditi. Prednost simultane strategije je u integralnom rješavanju problema i sistemskom istraţivanju svih interakcija izmeĎu navedenih mreţa, a nedostatak je povećana kompleksnost problema i njegovo teţe rješavanje. Daljni fokus u sintezi toplinsko integriranih mreţa vode bio je usmjeren na studiranje kombinovane mreţe komponovane od mreţe vode, mreţe otpadne vode i mreţe izmjenjivača topline. MeĎutim do sada je objavljeno samo nekoliko radova (19, 20, 42, 56) u toj oblasti, i najvjerovatnije to će biti fokus daljnih istraţivanja u ovoj oblasti. Simultana optimizacija takvih integralnih mreţa omogućava istovremenu optimizaciju potrošnje svjeţe vode, nastajanja otpadne vode i potrošnje energije u procesu. U narednom dijelu predloţen je i opisan novi konceptualni prikaz takve mreţe (slika 3). Ukupna mreţa se sastoji od mreţe procesnih jedinica, mreţe izmjenjivača topline, mreţe tretman jedinica i njihovih meĎusobnih konekcija. Svjeţa voda se moţe direktno uvoditi u mreţu procesnih jedinica ili grijati i/ili hladiti u mreţi izmjenjivača topline. U mreţi procesnih jedinica sa procesnog toka na tok vode se prenosi maseno opterećenje kontaminanata pri čemu nastaje otpadna voda. S obzirom da se procesne jedinice eksploatišu na odreĎenim temperaturama tokovi vode na izlazu iz mreţe procesnih jedinica mogu da budu topli i/ili hladni. Ti tokovi se uvode u mreţu izmjenjivača topline u cilju integracije topline da bi se zadovoljila temperaturna ograničenja u ukupnoj mreţi. U slučaju da se integracijom topline nisu postigle ciljne temperature u mreţi tada se vrši dodatno grijanje i hlaĎenje sa raspoloţivim energentima ili pogonskim sredstvima (ogrijevna para, rashladna voda). TakoĎer u mreţi procesnih jedinica je moguće ponovno korištenje vode iz jedne procesne jedinice u drugoj procesnoj jedinici ukoliko su time zadovoljena ograničenja na sadrţaj kontaminanata i temperaturu u drugoj procesnoj jedinici. Pored navedenog, tokovi otpadne vode iz mreţe procesnih jedinica mogu da budu usmjereni u mreţu tretman jedinica u cilju tretmana otpadne vode i njenog ponovnog korištenja i recikliranja. Tokovi vode na izlazu iz tretman jedinica mogu da budu topli i/ili hladni i oni se uvode u mreţu izmjenjivača topline u cilju integracije topline, te ako nisu dostignute ciljne temperature tokova vrši se dodatno grijanje i/ili hlaĎenje sa energentima. TakoĎer, tokovi vode na izlazu iz tretman jedinica mogu da budu usmjereni u mreţu za tretman otpadne vode u cilju regeneracije i ponovnog korištenja odnosno regeneracije i recikliranja vode (vidi sliku 2 c, d) ili kao tok efluenta ispušteni u okolinu pri čemu mora biti zadovoljeno ograničenje u odnosu na maksimalan sadrţaj kontaminanata u toku i temperaturu toka koji se ispušta u okolinu. TakoĎer, istraţivanje integriranosti mreţe procesnih jednica, tretman jedinica i mreţe izmjenjivača topline (slika 3) sa procesnom mreţom u kojoj se ima reakcijski i separcijski sistem bi moglo da bude fokus budućih istraţivanja u ovoj oblasti. 29 E. Ahmetović i sar.: ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Slika 3. Koncept integralne mreţe procesnih jedinica, mreţe izmjenjivača topline i mreţe za tretman otpadne vode. Figure 3. The concept of an integrated process units network, heat exchangers network, and wastewater treatment network. 4. ILUSTRATIVNI PRIMJER U ovoj sekciji rada je na konkretnom primjeru prikazana primjena metode matematičkog programiranja koja se bazira na optimizaciji superstrukture. U cilju ilustriranja primjenjivosti navedenog pristupa korišten je literaturni primjer (2, 20). Za navedeni primjer prvo je predstavljena konvencionalna izotermska mreţa procesnih jedinica u kojima se koristi samo svjeţa voda i nastaje otpadna voda. Nakon toga je dizajnirana izotermska mreţa procesnih jedinica u kojoj se ima ponovno korištenje vode i utvrĎena je minimalna potrošnja vode. MeĎutim, u praksi procesne jedinice se eksploatišu na odreĎenim radnim temperaturama, svjeţa voda koja se usmjerava prema procesnim jedinicama je odreĎene temperature i postavljena su ograničenja na temperaturu otpadne vode koja se ispušta u okolinu. Iz toga je očigledno da u procesu postoji veza izmeĎu potrošnje vode i potrošnje energije tako da je u narednom dijelu rada predstavljen dizajn neizotermske toplinsko integrirane mreţe vode koji je dobijen simultanom optimizacijom mreţe procesnih jedinica i mreţe izmjenjivača topline. 4.1. FORMULACIJA PROBLEMA Mreţa procesnih jedinica u kojima se koristi voda se sastoji od tri procesne jedinice čiji su podaci za maseno opterećenje kontaminanata koje se prenosi na vodu, maksimalnu koncentraciju kontaminanta u ulaznom i izlaznom toku iz procesne jedinice dati u tabeli 1. Na bazi tih podataka izračunat je granični protok za procesne jedinice. Procesne jedinice se eksploatišu na radnim temperaturama kako je predstavljeno u tabeli 1. 30 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 25- 36 , -Vanredno izdanje- Tabela 1. Podaci za procesne jedinice. Table 1. Process units data. Procesna jedinica LPU cinmax Process unit (ppm) (g/s) max cout (ppm) Granični protok vode Temperatura Limiting water flowrate Temperature (kg/s) (°C) 1 5 50 100 100 100 2 30 50 800 40 75 3 50 800 1100 166.7 100 LPU ‒ Maseno opterećenje kontaminanta/Mass load of contaminant (g/s); cinmax ‒ Maksimalna ulazna max koncentracija kontaminanta/Maximum inlet contaminant concentration (ppm); cout ‒ Maksimalna izlazna koncentracija kontaminanta/Maximum outlet contaminant concentration (ppm) Izvor svjeţe vode je bez kontaminanata i temperature 20°C. Voda koja se ispušta u okolinu je temperature 30°C. Toplo pogonsko sredstvo koje je na raspolaganju je vodena para temperature 120°C. Rashladno pogonsko sredstvo predstavlja rashladnu vodu čija je ulazna temperatura 10°C i izlazna temperatura 20°C. Cijena svjeţe vode je 0.375 $/t dok je cijena toplog i hladnog pogonskog sredstva 377 $/(kW∙y) odnosno 189 $/(kW∙y). Ukupni koeficijent prenosa topline iznosi 0.5 kW/(m2∙K). Investicijski troškovi za izmjenjivače topline sa cijevnim snopom i plaštom su procijenjeni prema jednačini 8000+1200·A0.6 pri čemu je A površina izmjenjivača topline (m2). Investicijski troškovi za izmjenjivače topline su svedeni na godišnji nivo. Pretpostavljeno je da se mreţa eksploatiše 8000 h/y, i da je specifični toplinski kapacitet vode konstantan i iznosi 4.2 kJ/(kg∙K). Potrebno je prvo dizajnirati izotermsku mreţu procesnih jedinica u kojoj se ima minimalna potrošnja vode i nastale otpadne vode. Nakon toga predstaviti optimalnu neizotermsku toplinsko integriranu mreţu u kojoj se ima minimalna potrošnja svjeţe vode i energije, te minimalno generisanje otpadne vode. 4.2. KONVENCIONALNI PRIKAZ IZOTERMSKE MREŢE VODE Konvencionalni prikaz mreţe procesnih jedinica (slika 4) predstavlja osnovni slučaj kada sve procesne jedinice koriste samo svjeţu vodu. U procesnim jedinicama se na tok vode prenosi fiksno maseno opterećenje kontaminanata tako da izlazna voda iz procesnih jedinica predstavlja otpadnu vodu. TakoĎer u ovom slučaju je razmotrena izotermska mreţa vode pri čemu temperature svjeţe vode, procesnih jedinica i otpadne vode nisu uzete u obzir. Minimalna potrošnja svjeţe vode u procesnoj jedinici je postignuta kada voda ulazi u procesnu jedinicu sa koncentracijom kontaminata 0 ppm a napušta procesnu jedinicu sa maksimalno dozvoljenom koncentracijom. Koristeći podatke iz tabele 1 i uzimajući pretpostavku da je isti protok vode na ulazu i izlazu iz procesnih jedinica odreĎena je minimalna potrošnja vode (132.955 kg/s) koja je jednaka protoku toka otpadne vode koji se ispušta u okolinu. Konvencionalni dizajn mreţe vode je prikazan na slici 4. 31 E. Ahmetović i sar.: ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Slika 4. Svjeţa voda je korištena u svim procesnim jedinicama. Figure 4. Freshwater used in all process units. 4.3. OPTIMALNI DIZAJN MREŢE VODE SA PONOVNIM KORIŠTENJEM VODE U PROCESU Voda na izlazu iz jedne procesne jedinice se moţe ponovo koristiti u drugoj procesoj jedinici ako je zadovoljeno ograničenje na maksimalno dozvoljenu koncentraciju kontaminanta u ulaznom toku vode u drugoj procesnoj jedinici. U tom slučaju se moţe smanjiti potrošnja svjeţe vode i nastale otpadne vode u procesu. Optimizacijom modela superstrukture potrebno je dobiti optimalnu alternativu sa stanovišta minimalne potrošnje svjeţe vode. U cilju dobijanja optimalne mreţe sa ponovnim korištenjem vode u procesu korišten je optimizacijski model (16) a dobijeni dizajni mreţe u kome se ima minimalna potrošnja vode (77.273 kg/s) su predstavljeni na slici 5. U tim mreţama tok vode na izlazu iz procesne jedinice 1 (PU1) je ponovno korišten u procesnim jedinicama PU 2 i PU3, a tok vode na izlazu iz procesne jedinice PU2 je ponovno korišten u procesnoj jedinici PU3. Dizajn mreţe na slici 5b je jednostavniji jer ima manje jednu konekciju u odnosu na dizajn prikazan na slici 5a. Kao rezultat ponovnog korištenja vode, potrošnja svjeţe vode i količina generirane otpadne vode je smanjena za oko 41.9 % (sa 132.955 na 77.273 kg/s). a) b) Slika 5. Optimalni dizajni mreţe vode sa ponovnim korištenjem vode. Figure 5. Optimal designs of water network with water reuse. 32 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 25- 36 , -Vanredno izdanje- 4.4. OPTIMALNI DIZAJN NEIZOTERMSKE TOPLINSKO INTEGRIRANE MREŢE VODE U većini realnih situacija u mreţi vode se pored zadovoljavanja ograničenja na sadrţaj kontaminanata moraju zadovoljiti i ograničenja u odnosu na temperature. U takvim slučajevima se mreţa vode i mreţa izmjenjivača topline trebaju razmotriti zajedno u cilju minimizacije potrošnje svjeţe vode i pogonskih sredstava (ogrijevna para, rashladna voda). Ukoliko se integracijom topline u mreţi izmeĎu toplih i hladnih tokova nisu dostigle ciljne temperature tokova potrebno je vršiti dodatno grijanje i/ili hlaĎenje tokova koristeći pogonska sredstva (ogrijevna para, rashladna voda) u cilju zadovoljenja postavljenih temperaturnih ograničenja. U prethodnom slučaju superstruktura mreţe vode je optimirana za izotermske uslove pri čemu je u dizajnu mreţe (slika 5) minimalna potrošnja svjeţe i nastale otpadne vode bila 77.273 kg/s. S obzirom da se u ovom slučaju pored ograničenja na sadrţaj kontaminanata u toku koji se uvodi u procesne jedinice moraju zadovoljiti i ograničenja temperatura potrebno je izvršiti simultanu optimizaciju superstrukture mreţe procesnih jedinica, u kojoj se vrši integracija vode, i mreţe izmjenjivača topline, u kojoj se vrši integracija topline. Optimizacijom modela superstrukture (21, 55, 57) potrebno je odabrati optimalnu alternativu sa stanovišta minimalnih ukupnih troškova mreţe koji se sastoje od troškova svjeţe vode, troškova pogonskih sredstva (ogrijevna para, rashladna voda) i investicijskih troškova izmjenjivača topline. U ovom slučaju simultanom optimizacijom se istraţuje dizajn mreţe u kome se ima najbolji kompromis izmeĎu navedenih troškova. Rezultati optimizacije za scenarije superstrukture mreţe (slučajevi 1-4) su predstavljeni u tabeli 2 (55). Optimalna potrošnja vode, količina nastale otpadne vode, i ukupni godišnji troškovi u slučajevima 2-4 su manji od istih rezultata za slučaj 1. Na slici 6 je predstavljen optimalni dizajn toplinsko integrirane mreţe vode (slučaj 4) u kome se imaju dva izmjenjivača topline i dva grijača. Ukupna potrošnja toplog pogonskog sredstva je 3245.5 kW. Najniţi ukupni godišnji troškovi toplinsko integrirane mreţe vode su postignuti sa najsloţenom superstrukturom i iznose 2 422 531.7 $/y. Table 2. Komparacija različitih dizajna toplinsko integrirane mreţe vode Table 2. Comparison of different designs of heat-integrated water networks. Slučaj 1 Slučaj 2 Slučaj 3 Slučaj 4 Case 1 Case 2 Case 3 Case 4 87.2 77.273 77.273 77.273 3671.4 3245.5 3245.5 3245.5 305 913.3 396 966.3 389 679.8 364 449.9 2 631 805.4 2 455 048.1 2 447 761.7 2 422 531.7 Potrošnja svjeţe vode Freshwater consumption (kg/s) Potrošnja toplog energenta Hot utility consumption (kW) Godišnja investicija Annual investment ($/a) Ukupni troškovi Total annual cost ($/a) Slučaj 1. Rezultati iz (20); Case 1. Results from (20); Slučaj 2. Tokovi između procesnih jedinica nisu uzeti u obzir za toplinsku integraciju (57); Case 2. Process-to-process streams were not taken into account for heat integration (57); Slučaj 3. Neizotermsko miješanje nakon izmjene topline i tokovi između procesnih jedinica nisu uzeti u obzir za toplinsku integraciju; Case 3. Non-isothermal mixing after matches and process-to-process streams were not taken into account for heat integration; Slučaj 4. Procesni tokovi su uzeti u obzir za toplinsku integraciju; Case 4. Processto-process streams are taken into account for HI. 33 E. Ahmetović i sar.: ODRŢIVO UPRAVLJANJE VODOM, OTPADNOM VODOM I ENERGIJOM U PROCESNOJ INDUSTRIJI Slika 6. Optimalni dizajn toplinsko integrirane mreţe vode kada su tokovi izmeĎu procesnih jedinica uzeti u obzir za toplinsku integraciju (55). Figure 6. Optimal design of heat-integrated water network when process-to-process streams are taken into account for heat integration (55). 5. ZAKLJUČCI U ovom radu je istaknut značaj primjene sistemskih metoda, pinch tehnologije i matematičkog programiranja, u dizajniranju ekonomsko efikasnih i ekološko odrţivih procesa odnosno njihova primjena u odrţivom upravljanju vodom, otpadnom vodom i energijom u procesnoj industriji. Predstavljen je opšti koncept korištenja vode u industrijskim procesima i istaknut je značaj ponovnog korištenja vode, regeneracije i ponovnog korištenja vode i regeneracije i recikliranja vode u cilju smanjenja potrošnje svjeţe vode kao i nastajanja otpadne vode. Nakon toga je diskutovana suština sinteze mreţa izmjenjivača topline, vode i otpadne vode i predstavljen je novi koncept sinteze kombinovanih mreţa izmjenjivača topline, vode i otpadne vode i date su smjernice za moguća buduća istraţivanja u toj oblasti. Na kraju je na konkretnom primjeru prikazana primjena metode matematičkog programiranja, koja se bazira na optimizaciji superstrukture, i predstavljeni su rezultati za izotermsku i neizotermsku mreţu vode. U prvom slučaju dobijeni rezultati su isti kao rezultati u literaturi, dok su u slučaju neizotermskih toplinsko integriranih mreţa prikazani poboljšani rezultati sa stanovišta integriranosti mreţe i ukupnih godišnjih troškova. ZAHVALE Autori se zahvaljuju podršci od strane EM JoinEU-SEE, EM2-STEM i CEEPUS programa za finansijsku podršku u vezi mobilnosti, sticanja novih znanja i usavršavanja, te za finansijsku podršku od strane Slovenske agencije za istraţivanje (Program broj: P2-0032). LITERATURA 1.Davé, B. 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Chemical Engineering Transactions, 29 (2012), 1015-20. SUSTAINABLE WATER, WASTEWATER, AND ENERGY MANAGEMENT IN THE PROCESS INDUSTRIES Elvis Ahmetović1, Nidret Ibrić1, Zdravko Kravanja2 University of Tuzla, Faculty of Technology, Tuzla, Bosnia and Herzegovina 2 University of Maribor, Faculty of Chemistry and Chemical Engineering, Maribor, Slovenia 1 Water and energy are important natural resources which are usually used in significant quantities in the process industries. Different approaches have been proposed and implemented over the last two decades in order to minimize freshwater usage, wastewater generation, and energy consumption, within water networks. Earlier studies only addressed the investigating of various strategies for water and wastewater minimization within isothermal water networks (water reuse, wastewater treatment and water recycling), whilst more recent approaches have also considered energy minimization together with freshwater and wastewater minimization. In this work a superstructure optimization is presented as an approach for the simultaneous synthesis of overall water, wastewater, and energy networks. An example from literature is used in order to illustrate the applicability of the proposed approach. A base case is first presented for the water network synthesis problem. Then the water networks are synthesized using simultaneous optimization. The obtained results are the same or better than those reported in the literature. An optimal non-isothermal water network featuring optimal freshwater usage, wastewater generation, energy consumption, and investment is realized when finally process-to-process streams are taken into account for heat integration. Key words: sustainable industry, water integration, energy integration, simultaneous synthesis, superstructure optimization 36 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 37-42 , -Vanredno izdanje- RECENT ACHIEVEMENTS IN MEAT COLOR Bjørg Egelandsdal4, Milena Bjelanovic, Mamta Khatri and Erik Slinde Department of Chemistry, Biotechnology and Food Science, University of Life Science, Postbox 5003, N-1432-Ås ISSN 2232-755X DOI: 10.7251/GHTE13VI037E UDC 637.13.05+637.5.05 Meat color is an important quality variable that affects consumers’ willingness to purchase and re-purchase meat. The importance of meat color has called for extensive research into the mechanism of colour stability. In many cases only color measurements that relate to how a sample is seen by the human eye, is needed. However, in other situations it is necessary to know the actual states of myoglobin on meat surfaces. Calculation of myoglobin states is not straightforward, neither are the principles used for preparing pure myoglobin states; a prerequisite for making the predictive models. In this presentation, we will discuss the methods used for preparing pure myoglobin states, plus the most common method used to calculate myoglobin states. In addition, we will introduce a new method of calculating myoglobin states. This new method uses the complete reflection spectrum instead of just selected wavelengths as used in the most common method for calculation ofmyoglobin states. The new method gives improved accuracy. Key words: meat, meat color, myoglobin INTRODUCTION Meat color is an important quality variable that affects consumers’ willingness to purchase and re-purchase meat. The importance of meat color has called for extensive research into the mechanism of color stability. Colorimeters (like the more common Minolta versions) will only measure tristimulus values (CIE L*a*b*, 1976). Such instruments are easy to use and will in many cases provide relevant, objective measurements regarding how a surface is seen by the human eye. The technique quantifies color by measuring three color components which are seen by the human eye specifically, red, green and blue (also referred to as ―RGB‖). a b c Figure 1. Left(a) is a picture of Konica Minolta CM 700D with spectral option from 400 - 700nm (resolution 10 nm). The equipment measures reflection of a surface plus the tristimulus values (CIE L*a*b*). In the middle (b) is the 40 x 40mm2 optiprobe TM system (23 x 23mm illumination area) to be attached to FOSS NIRSystems Model 6500- here pictured with another remote sensor (c). The probe (b) measures reflectance spectra from 400-1100 nm. The exact penetration depth of light for these two systems was not measured. FOSS NIRSystems Model 6500 was used to get reflectance spectra in the papers by Khatri et al. (2012) and Bjelanovic et al. (2013). The image in panel c was provided by Bjørg Narum Nilsen Spectrophotometers are more complex instruments that supply spectral analysis with different degrees of resolution. Spectrophotometers are necessary if one aims at quantifying myoglobin states. Two instruments that can both measure reflectance spectra are shown below (Figure 1). 4 Bjørg Egelandsdal , Department of Chemistry, Biotechnology and Food Science, University of Life Science, Postbox 5003, N-1432-Ås, e-mail: bjorg.egelandsdal@umb.no 37 B. Egelandsdal et al.:RECENT ACHIEVEMENTS IN MEAT COLOR PREPARING PURE MYOGLOBIN STATES In order to calculate the three states of deoxymyoglobin (DMb), oxymyoglobin (OMb) and metmyoglobin (MMb) from reflectance measurements in the visible range (400 -700 nm), an instrumental calibration is required where pure states (i .e. DMb, OMb and MMb) are produced and measured with the type of sample, packaging material and instrumentation to be used in the main experiment. In the main experiment unknown samples are then measured. All laboratories doing these types of myoglobin state determinations should set up their own calibration before they can calculate the states of myoglobin of unknown samples. Adding the chemicals sodium dithionite and potassium ferricyanide (Wilson, Ginger, Schweigert and Aunan, 1959) is known to produce DMb and MMb, respectively. OMb is readily formed by flushing the surface DMb of meat with 100% oxygen. Alternatively, meat with DMb, MMb and OMb can be produced with modified atmosphere packaging by adjusting the partial pressure of oxygen (O2) to zero, low or high concentrations, respectively (Taylor, Down, & Shaw, 1990; Hunt, Sørheim, & Slinde 1999). No matter which calculation principle will be used later for calculation of myoglobin state, careful and correct production of pure states are necessary. Table 1 shows the preparation methods that were recommended in the recent, revised AMSA Meat Color Measurement Guidelines that were released in 2012. Included in Table 1 are the preparation principles that have been used by Khatri et al. (2012) and Bjelanovic et al. (2013). Their preparation methods were largely based on the first issue of the AMSA guidelines as well as some amendments that we found relevant to carry out. Table 1 is not exhaustive and we strongly recommend the readers to consult the actual references for details about how the preparations were carried out (e.g. packing materials and similar). CALCULATING PRINCIPLES OF MYOGLOBIN STATES In order to calculate myoglobin states surface reflection measurements in the visible range 400-700 nm (or 470-610 nm) must be available for the more common method where transformation of reflectance measurements to K/S values are used. This transformation is used to improve on linearity and reduce the contribution from scattering and, in essence, to make the spectra look more like transmission spectra. Table 1 Comparison of recent preparation methods to prepare 100% pure myoglobin states. State Prep. IA -Intact meat– IB- Intact meat method (AMSA, 2012)* (Khatri et al., 2012) Immerse in 1.0% potassium ferricyanide for 1 min, drain, blot surface, package in oxygen-permeable film, store at 2 - 4°C in 1% oxygen for 48 hours. Immersed in 1% potassium ferricyanide for 1 min, drained, blotted dry, packed in oxygen-permeable film, stored at 2 - 4°C for 12 hours. Four days old meat. Chemical Met Packing Comminuted Measure in oxygenpermeable film. Use older meat. Stored meat at initial O2 level of 1.5 % added 60 % CO2/40 % N2 Stored to day 7 at 4°C, (gas: meat= 30 :1). Examined in oxygenpermeable film. Four days old meat II Bmeat Comminuted (AMSA, 2012) (Bjelanovic 2013) Not commented on. Immersed in 1% potassium ferricyanide for 1 min, drained, blotted dry, packed in oxygen-permeable film, stored at 2 - 4°C for 16 hours. Examined in oxygenimpermeable film. Six to thirteen days old meat. Flatten it with roller, pack in 1% O2 and 99% nitrogen. After 48 hours at 4°C, repack and measure in oxygen-permeable film Not examined Use older meat. Store meat in an oxygen-impermeable bag with an atmosphere of 1% oxygen and 99% nitrogen at room temperature (20°C) for 6 hours; (gas: meat > 3 :1), keep at > 48 hours at 4°C. 38 IIAmeat et al., Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 37-42 , -Vanredno izdanje- Not commented on Packing Chemical Oxy Chemical Deoxy Expose samples at 0 2°C in a high-oxygen atmosphere (70 100%), store 24-48 hours at 0 - 2°C,(gasto-meat volume > 3 to 1). Immerse samples in 0.15% dithionite about 20°C, 1 -2 minutes, drain, blot surface, vacuum package, and allow to reduce for 1- 2 hours at 20°C. Repackage in oxygen-permeable, scan immediately. 1) Make a fresh-cut surface on the sample’s interior surface, scan immediately. Packing 2) Vacuum samples in impermeable bag, store hours at 4°C. package oxygenvacuum 24 -48 Meat at 2°C was flushed with 100% oxygen for 10 minutes. Examined in oxygen-permeable film. Four days old meat. Packed in 75 % O2/ 25 % CO2,, 4°C, and measured after 24 hours, C, (gas: meat= 30:1). Examined in oxygenpermeable film. Four days old meat. Not commented on. Not examined Immersed 10% dithionite for 2 min, drained, blotted dry and vacuum packaged to reduce for 2 hours at room temperature. Repackaged in oxygen-permeable, scanned immediately. Four days old meat. Samples were vacuum-packaged and kept at 2-4°C for 48 hours, C, (gas: meat= 30:1). Ground product can be For ground product, package layer. in a thin supported using screen in a beaker Packed in 100 % O2 and measured after 45 min, at 4°C.Examined in oxygenimpermeable film. Three to thirteen days old vacuum-packed meat was used. Not examined. a Not commented on. Samples were vacuumpackaged and kept at 4°C for 0-13 days. Measured after 3 days. No re-packing. Repackaged in oxygen-permeable, scanned immediately. Four days old meat. Holding the samples at 20°C for at least 50% of the time speeds up reduction time. Scan through the vacuum packaging film. * More details will be found in the references; the table is just to outline some major differences. Then convert reflectance percentages to K/S values the following equation is used: K/S = (1 − R)2 ÷ (2R) (eq. 1) where R = % reflectance. The values obtained from the pure states enter the calculation as shown in the equation below: (eq. 2) Using this equation the fraction of OMb is calculated using the reflectance spectra of pure metmyoglobin and oxymyoglobin. The deoxymyoglobin state can be calibrated from the reflectance spectra of pure deoxymyoglobin and oxymyoglobin (AMSA). More equations can be found in AMSA guidelines (2013). 39 B. Egelandsdal et al.:RECENT ACHIEVEMENTS IN MEAT COLOR And finally metmyoglobin can be calculated from the difference: % MMb = 1 - % OMb - %DMb (eq. 3) Khatri et al. (2012) used this method where K/ S values, at selected wavelengths (SW), were used to predict myoglobin states on unknown samples. She compared it with a method where the complete absorbance (A) spectra were corrected using extended multiplicative scatter correction (EMSC(A)) before the partial least square regression models was built. EMSC is a pre-processing technique used to isolate and remove complicated multiplicative and additive effects, such as those caused by light scattering in reflectance spectroscopy (Gallagher, et al., 2005). Partial least squares regression (PLS regression) is a statistical method used to find the fundamental relations between two matrices (X and Y, here spectra and myoglobin states), i.e. a latent variable approach to modelling the covariance structures in these two spaces (Martens H, & Næs, T., 1989). PLS regression is particularly suited when the matrix of predictors (here absorbance values at many different values) has more variables than observations, and when there is multicollinearity among X values. This is also the case here as many readings at the different wavelengths are correlated. Method 1 SW K/S Method 2 EMSC (A) A PLS Post-transformation Figure 2.The steps in the 2 different mathematical treatments of data used to calculate myoglobin states. Method 1 and 2 were used in the paper by Khatri et al. (2013); Method 2 was used in the paper by Bjelanovic et al. (2013). After calculations of states from the PLS regression (Method 2), a post-transformation was carried out where the sum of states was normalized to 1.0 or 100%. This is necessary since we calculated all 3 states (OMb, MMb and DMb) independently of each other. Therefore, their sum may not be zero since there are errors in the determination of the states. This problem does not occur if eq. 3 is used. The hypothesis behind this new approach was that the use of single wavelengths based on isobestic points would be risky on scattering material (Khatri et al., 2012). This means that we in general question the relevance of isobestic points on such material as meat. Table 2. Comparison of predictability of states using different preparation method and regression techniques Root mean square error of prediction for myoglobin fractions (scale 0-1)* State Prep. IB- intact meat (Khatri et al., 2012) II B- Comminuted meat (Bjelanovic et al., 2013) Method 1 Method 2 Method 2 method MMb OMb DMb Chem 0.079 0.029 0.045 Packing 0.28 0.039 Not tested Chem 0.16 0.080 Not tested Packing 0.12 0.041 0.055 Chem 0.18 0.081 Not tested Packing 0.26 0.042 0.051 * 1 means 100 % pure 40 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 37-42 , -Vanredno izdanje- PREDICTABILITY OF MYOGLOBIN STATES USING VARIOUS CALCULATION METHOD The recent AMSA guidelines (2012) do not give any indication of the analytical error to be expected. Khatri et (2012) showed that the use of four so-called isobestic wavelength (474 nm, 525 nm, 572 nm and 610 nm) cannot compete with Method 2 that used all spectral values from 400 -1100 nm, every second nanometer). It was only the prediction of MMb that was relatively reliably predicted. This suggests that the preparation method used was good, but also that the wavelengths picked out for quantification of MMb in by Method 1 were useful. DMb is difficult to prepare and calculations according to Method 1 would not be useful for this difficult state. A part of the error could reflect repacking and the fact that DMb quickly picks up oxygen, so that a pure state is never prepared if there is access to oxygen during measurements of this state. However, our results suggested that it is also more difficult to measure on comminuted meat than on intact meat. The advice given by AMSA regarding supporting the mince during measurements (Table 1) is worth being tested. It is necessary to remember that all calibration models for meats must ultimately be validated by applying it to new, but similar meats. The oxygen preparation method with packing in high oxygen for 24 hrs in the cold seems to be a good principle, but our results suggested that shorter incubation times may work as well (Table 1 and 2). WHAT SORT OF INSTRUMENT IS REQUIRED FOR PREDICTING MYOGLOBIN STATES? As stated above we do not recommend using only 4 wavelengths for predicting myoglobin states even if the best possible preparation method for each state is used. Both Bjelanovic et al. (2013) and Khatri et al. (2012) used the wavelength from 400 to 1100 nm. Bjelanovic et al. (2013) gave the regression coefficients at all wavelengths: Regression coefficients may give some indication about the importance of higher (700 nm – 1100 nm) wavelengths. From this we can deduce that the most important region for prediction myoglobin states is between 400-700 nm. However, we do not know how much the predictability seen in Table 2 will be reduced by constraining the wavelength region to 400 - 700 nm. The instrument shown in Figure 1 (Minolta CM 700D) returns reflectance readings between 400 - 700 nm (every 10 nm) and at least for MMb it should give good predictions since this state seems the least dependent of the number of wavelengths used. Also for OMb, it may be possible to get a reasonable estimate. The DMb state is difficult both to prepare and analyze so it would be mere speculation how the predictability may be using Minolta CM 700D. Another issue that is very difficult to handle is the fact that every instrument has different abilities to penetrate the meat matrix. If penetration is significant this may be an advantage for quantification of DMb state quantification, but a disadvantage for the 2 other states. The advice is to optimize the routines for preparation of states and measuring so that the error is minimized. CONCLUSION Recent results regarding quantification of surface myoglobin states on a meat matrix can only be done accurately for metmyoglobin using a 4 wavelength regression model. More wavelengths and multivariate regression methods in combination with optimal preparation methods for pure states are needed for the OMb and DMb states. Both our experiments (with intact and comminuted meat) give very good results in validation of models, but there will always be a need to adapt the preparation methods for the 100% pure states to the instrument used. Acknowledgements The work was supported by grant no. NFR184846/I10 from the Research Council of Norway and from HERD project ―Comparison of lamb Carcass and meat quality of Breeds in Western Balkan and Norway achieving improved palatability, sale and sustainability‖. 41 B. Egelandsdal et al.:RECENT ACHIEVEMENTS IN MEAT COLOR REFERENCES 1. American Meat Science Association , AMSA Meat Color Measurement Guidelines from American Meat Science Association (2012) web information at: information@meatscience.org http://www.meatscience.org American Meat Science Association. (1991). Guidelines for Meat Color Evaluation (AMSA). (M. Hunt, Acton, J., Benedict, R., Calkins, C., Cornforth, D., Jeremiah, I. et al., Eds. Proceedings of the Reciprocal Meat Conference, 117. Bjelanovic, M., Sørheim, O., Slinde, E., Puolanne, E., Isaksson†, T. & Egelandsdal, B. (2013). Determination of the myoglobin states in ground beef using non-invasive reflectance spectrometry and multivariate regression analysis. Meat Science, 451-457. CIE (Commission Internationale de l’E’clairage) (1976). Recommendation on uniform color space-color difference equations, psychometric color terms. Suppl. 2 to CIE, Publication No. 15 (E-1.3.1) 1971/(TC-1-3), Paris, France Gallagher, N. B., Blake, T. A., & Gassman, P. L. (2005). Application of extended inverse scatter correction to midinfrared reflectance spectra of soil. Journal of Chemometrics, 19, 271-281. Khatri, M., Phung, V. T., Isaksson, T., Sørheim, O., Slinde, E., & Egelandsdal, B. (2012). New procedure for improving precision and accuracy of instrumental color measurements of beef. Meat Science, 223-231. Martens H, & Næs, T. (1989). Multivariate Calibration. John Wiley and Sons, Chichester, United Kingdom. Taylor, A., Down, N., & Shaw, B. (1990). A comparaison of modified atmosphere and vacum skin packing for the storage of red meats. International Journal of Food Science & Technology, 98-109. Wilson, G. D., Ginger, I. D., Schweigert, B. S., & Aunan, W. J. (1959). A Study of the Variations of Myoglobin Concentration in ''Two-Toned'' Hams. Journal of Animal Science, 1080-1086. 2. 3. 4. 5. 6. 7. 8. 9. NOVIJA ISTRAŢIVANJA O BOJI MESA Bjørg Egelandsdal, Milena Bjelanovic, Mamta Khatri and Erik Slinde Department of Chemistry, Biotechnology and Food Science, University of Life Science, Postbox 5003, N1432-Ås Boja mesa je veoma vaţna kvalitativna varijabla koja utiče na spremnost potrošača da kupe meso ili na odluku da ga ne kupe. Značaj boje mesa je uticao na opseţna istraţivanja o mehanizmu stabilnosti boje. U mnogim slučajevima samo mjerenje boje mesa nam da je informaciju kako tu boju vidi ljudsko oko i takva mjerenja su naravno potrebna. MeĎutim, u drugim slučajevima neophodno je poznavati trenutno stanje mioglobina na površini mesa. Proračun stanja mioglobina nije jednostavan, kao što nisu jednostavne metode pripreme stanja čistog mioglobina; to su preduslovi za buduće modele. U ovoj prezentaciji diskutovaćemo o metodama koje se koriste za pripremu stanja čistog mioglobina, i o uobičajenoj metodi za proračun stanja mioglobina. Dodatno, predstavićemo novu metodu za proračun stanja mioglobina. U ovoj novoj metodi se koristi kompletan refleksioni spektar umjesto samo probranih talasnih duţina, kako je to bilo uobičajeno u proračunima stanja mioglobina. Nova metoda povećava preciznost mjerenja stanja mioglobina. Ključne riječi: meso, boja mesa, mioglobin 42 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 43-49, -Vanredno izdanje- CLOTHING DESIGN AND FIT COMFORT BASED ON BODY MOTION Jelka Geršak University of Maribor, Faculty of Mechanical Engineering, Maribor, Slovenia jelka.gersak@um.si ISSN 2232-755X DOI: 10.7251/GHTE13VI043G UDC 688.721:640.46 The clothing quality, which meets the demands and expectations of customers, depends on one hand on the aesthetic appearance and the quality of the material used. This can be regarded as concrete measurements of customers. On the other hand, clothing quality depends on the properties of produced clothing, which seems to be the crucial criterion of the end product. Applicable properties of clothing are reflected through the wearing comfort and clothing behaviour during wearing, i.e. adaptation to body motion and clothing resistance against acting dynamic loading. This contribution provides an overview of the ease allowance adopted to provide comfort during body motion. For this purpose the interaction between body motion and clothing as shell are explained. The contribution then discusses the fit and allowance for comfort and wearability, and also includes a grounded model development and detailed overview of various kinds of ease allowance for comfort. Key words: body shape, clothing, ease allowance, fit, wearing-comfort INTRODUCTION Clothing is apparently something basic to civilization (1). It is a term referring to a covering that is worn to cover the body or to keep warm. It is exclusively a human characteristic and is a feature of nearly all human societies. The kind and type of clothing worn depends on functional considerations (such as the need for warmth or protection from the elements) and social considerations (2). Clothing quality is not only defined through its aesthetic and functional properties, but also as mechanical and physiological of wear, e.g. the feeling of well-being in wearing, its proper drape and fit (3). While constructing highquality clothing, such as those that have to satisfy the requirements of individuality, e.g. in fulfilling high standards of comfort in wearing, it is necessary to pay special attention to obtain high-quality appearance (clothing form), as well as to fit the clothing to the anatomic part of the human body in question. The last two factors as performance attributes are directly linked to the investigations of fabric mechanics, meaning its ability to the processed from twodimensional cutting patterns to a three-dimensional form of an article of clothing, and requirements for ease allowance for comfort and wearability. These performance attributes are very complex. No theory can be developed without the knowledge of experimentally defined basic constants and a comprehensive verification against existing experimental data. Theoretical and experimental investigation must always go hand-in-hand to provide important interacting support. Starting points for qualitative evaluation of clothing appearance quality are the study of the influence of fabric mechanical properties on the assurance of clothing appearance quality level, as well as definition of the elements for qualitative evaluation of the quality of clothing appearance (3). The quality elements of a clothing visual appearance are defined on the basis of evaluation of clothing drape quality, resp. clothing fall (fall of the front/back part and sleeves, adjustment of different components and materials), assurance of 3D shape (quality of a form, its spatial characteristic, fullness, for instance of the front part, voluminal adjustment, shoulder and sleeve form etc.), quality of clothing fit (fit of the shoulder to the contour of the body, fit of the front part and collar, etc.) and visual appearance of the quality of produced seems, such as seam puckering, seam flotation, shear-deformed seam, and so on, Fig. 1 (3, 4). 43 J. Geršak.: CLOTHING DESIGN AND FIT COMFORT BASED ON BODY MOTION Fig. 1 The elements of the qualitative evaluation of clothing appearance quality In addition to the quality of the clothing appearance, wearing comfort requires a special attention. Wearing comfort is one of the key features of any article of clothing. Human body is in a constant motion. During this motion, the parts of the body undergo dynamic change, meaning that the ability to move is determined and limited by more than just the static dimensions of the body. Considering the comprehension of issues, in this work we will present fit and allowance for comfort and wearability, where design criteria for fit and ease allowance for comfort and wearability must be unequivocally specified. It must also be noted that wearing comfort can only be realistically planned on the basis of the role and function of the clothing, which can affect the extent of body motion and the resulting changes on the surface of the body. These changes play a role in determining the requirements for ease allowances and also affect the loads that act on clothing during wearing. STUDY OF INTERACTION BETWEEN BODY MOTION AND CLOTHING AS SHELL It is well known that dynamic anthropometrics variables, which refer to the different working postures of human body, are important information about movement amplitude in the joints, reach field of the hand, as well as about muscular strength. When the human body is bent by different working postures the body tissue is stretched (5). The more body tissue is stretched the further the distance to the axis of the bending. Changes in body shape during motion and/or work and the behaviour of individual parts are determined by the type of activity being undertaken. Some typical positions used to assess mobility are shown in Fig. 2. Fig. 2 Typical positions of the body 44 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 43-49, -Vanredno izdanjeDetermining the extent of dynamic loading acting on clothing during wearing is a complex problem, and requires an understanding of the interaction between changes in body posture, body surface measurements during motion, and the deformation of clothing. The analysis of dynamic loading acting on a clothing during wearing showed that the changes of dimensions of the body surface directly affect loaded garment parts. The acting loading was shown as clothing deformation, or fabric extension, Table 1, respectively (6). Table 1 The average values of measurement of stretching force F and deformation different body movements (6) Body posture Contracted arms on shoulder specific extension for jacket at Stretch force Specific extension F /N /% On sleeve 38.0 2.24 On shoulder blade 52.5 2.92 In the middle of the back 62.5 3.42 On sleeve 48.5 2.72 In the middle of the back 25.5 1.65 Measuring position Bending Resulting clothing deformations depend on the body posture at the moment of the movement, respectively, on the resulting changes of body surface, number of cyclic repetitions of the movements and fabric properties. On the other hand, the intensity of acting dynamic loading depends on body constitution and clothing style. These insights are important for designing clothing fit and allowance for comfort, and wearability. Clothing should be designed to be able to adapt to this type of changes. A key criterion of wearability can therefore be defined as the ability to move in the clothing without effort, or clothing must take account of the activities of the human body, and not interfere with movements such as walking, sitting, standing, bending, stretching. In addition, they must also permit the body to perform normal physiological activity. This means the blood must circulate, the body must sweat and breathe. This freedom of motion of clothed persons is dependent on both the fabric used and the construction of the clothing. Clothing must able to stretch to the same degree as skin. If clothing is not in direct contact with the skin it must allow greater extension. FIT AND ALLOWANCE FOR COMFORT AND WEARABILITY In view of interaction between body motion and clothing as a shell, it can be seen that changes in body position during motion reflected as dimensional changes of body surface, which act on the clothing in a form of stretching load. Different types of clothing adapt to resulted changes of dimensions of body surface during the motion in very different ways. These changes depend on body constitution, as well as on kind and fastness of a movement. Knitwear, for example, is able to adapt very well to dimension changes of body surface, thanks to its elastic structure; under loading condition, the force is transferred from the clothing to the material - knitted fabric. In contrast, clothing produced from ordinary woven fabric does not adapt so easily to these changes, therefore it must be achieved through the ease allowances for movement or allowances for comfort, i.e. suitable looseness and possible gliding along the body. In terms of clothing adaptation to dimensional changes of body surface it is important that the fabric used for clothing must be able to cope with the difference between the changing dimensions of the surface of the body and the dimensions of the clothing as a shell. This can be achieved through appropriate ease allowances, which allow clothing to slide over the surface of the body when dimensional changes occur. This means that clothing is able to adapt to new dimensions and should fit the body smoothly with enough space to move easily, i.e. provide the wearer with the required level of comfort and mobility. Fit of the clothing with body is an important factor that needs to be taken into account in the design of comfortable and functional clothing. Clothing fit is a complex property, determined by a combination of ease, line, grain and balance (7, 8). It is also influenced by fashion and style, clothing size variation, and by perception of the individual. 45 J. Geršak.: CLOTHING DESIGN AND FIT COMFORT BASED ON BODY MOTION GROUNDED MODEL DEVELOPMENT Wearing comfort is one of the key properties of any article of clothing. It depends not only on body measurements and construction of the clothing, but on mechanical and structural properties of the selected fabric and importantly also on the allowance for comfort. Allowance for comfort, called also ease allowance for movement, is the amount of ease allowance of clothing, defined as the difference in space between the clothing and the body, resp. between the measurement of the pattern or clothing in a given area and the measurement of the body. It can be considered in the pattern by increasing the area along its outline. The amount of ease allowance required depends on the clothing type, design, the fabric, the body type, the function of clothing as well as on personal preference (9). In terms of function, it can be considered at two levels, namely: - ease allowance that is added to achieve improved comfort and wearability, and - design ease allowance that is added by the designer to create a particular style or look. The first type is employed to enable the wearer to move, bend, breathe, sit, raise the arms and walk without the clothing being over pulled, pinched, bent, stretched, or strained beyond a natural relaxed position (10). Contrary to this, the design ease allowance is based on the aesthetic considerations and personal preferences, and represents ease allowance added by creating different styles or look according to fashion trends and personal preference. A successful design should include the following steps in order to identify basic requirement for comfort and wearability: a) b) c) problem recognition, problem definition, objective set-up, defining the style, type of fit, personal preference and functional requirements of the clothing, defining the level of mobility, defining the degree of free movement, defining the additional requirement for wearing comfort, including the physiological and psychological aspects on one hand, and the mechanical and ergonomic on the other, d) design ease allowance / technical solution, the choice of materials, defining the structural and mechanical properties of materials, defining of an adequate garment pattern construction, defining the seam performance and position on clothing, defining the clothing position on body, defining the kind and amount of ease allowances for comfort, e) ease allowance for comfort – selection guidelines, including: design specification, prototype construction, prototype development, f) evaluation / modification, g) checking the kinetic and ergonomic features of clothing – comfort wear test / testing in actual use, h) evaluation of the final solution and implementation of ease allowance for comfort within clothing. A schematic representation of the ease allowance within the clothing design process can be seen in Fig. 3. It is obvious that these complex requirements should be met when designing wearing comfort from the point of ease allowance, material characteristics, design, seam performance and clothing position on body. In practice, there are actually four types of the ease allowance for comfort and wearability (10-14): 46 standard ease allowance, dynamic ease allowance, mechanical ease, also called fabric ease allowance, and ergonomic ease allowance. Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 43-49, -Vanredno izdanje- Fig. 3 Ease allowance within the clothing design process Standard ease allowance, based on the standard human body shape for a standing posture or sitting posture, is the difference between the maximal and minimal perimeter of the wearer’s body (11). Dynamic ease allowance, sometimes referred to as kinetic comfort, is defined as the ability to allow wearers to move (extreme movements and postures). It provides sufficient space to the wearer, so in the case of non-standard body shapes (thin, fat, big hip, etc.) as during their movement as walking, jumping, running, sprinting, and so on (15). Mechanical ease allowance, also called fabric ease, which refers to the mechanical comfort for wear, takes into account the influence of mechanical properties of fabrics used in the clothing. Mechanical comfort is expressed by a limited range of mechanical parameters of fabric tensile and shear deformation, such as fabric tensile strain in warp EMT1 and weft EMT2 direction measured with KES-FB standard condition (16), the relation between fabric tensile strain in the weft and warp direction α (α = EMT2/EMT1), linearity LT, tensile resilience RT, shear rigidity G and shear hysteresis 2HG5 (13, 17). Ergonomic ease allowance is expressed by constructive solution of clothing as lightweight clothing system that will allow unhindered movement and work, and involves the adjustment of the design, structure and construction of the clothing. The clothing should be ergonomically designed, in accordance with the dynamic anthropometric conditions of use and functionality, while still allowing wearing comfort and a high degree of free movement, as well as uninterrupted and safe work activities. All possible conditions of use must be taken into account, for example carrying tools, devices, and so on (14). 47 J. Geršak.: CLOTHING DESIGN AND FIT COMFORT BASED ON BODY MOTION In addition to the mentioned ease allowance, clothing positioning on body concerning the gradual order of the clothing to be worn plays a significant role in designing comfortable and functional clothing. F. Burgo (18), who studied the impact of different elements on ease allowance, concluded that the value of the wideness determining ease allowance was variable in function with three elements: the line of the clothing (the line determines the style of the pattern), which can be: the classic line – able to satisfy the taste and practice of a modern woman, the fitted line – characteristically hugs the body, loose fitting line – asks for more ease allowance and can be fitted with gathers, pleats or flaring; b) degree of clothing (in gradual order of the clothing to be worn); c) thickness of the material (thick or less thick, the fabric in the seam allowance occupies space and reduces ease allowance). From the point of gradual order that the clothing is worn, F. Burgo (18) described the following degrees of clothing: a) zero degree – clothing worn directly in contact with the skin, such as underwear and bathers, first degree – clothing worn directly on top of the underwear, second degree – clothing worn on top of the first degree of clothing, third degree – very heavy weighty clothing, and fourth degree – clothing with lining, such as fur or quilting. An example of the values for individual degree ease allowance according to the clothing positioning on the body, suggested by Burgo (18) is shown in Tab. 2. Table 2. Ease allowance according to the clothing positioning on body (18) Ease allowance /cm Control dimension Zero degree First degree 2nd degree 3rd degree 4th degree Chest girth from -4 to 0 from 2 to 6 from 6 to 12 from 12 to 16 from 16 to 24 Bust girth from -4 to 0 from 2 to 6 from 6 to 12 from 12 to 16 from 16 to 24 Waist girth from -4 to 0 from 2 to 6 from 6 to 12 from 12 to 16 from 16 to 24 Hip girth from -4 to 0 from 2 to 6 from 6 to 12 from 12 to 16 from 16 to 24 Shoulder width from -4 to 0 from 1 to 3 from 1 to 3 from 4 to 6 from 4 to 6 Breast distance from -0.5 to 0 from 0.25 to 0.75 from 0.75 to 1.5 from 1.5 to 2 from 2 to 3 Lowering arm hole from -1 to 0 from 0.25 to 1.5 from 1.5 to 3 from 3 to 4 from 4 to 8 Neck-opening from -0.25 to 0 from 0.25 to 0.75 from 0.75 to 1 from 1 to 2 from 2 to 3 CONCLUSION AND FUTURE TRENDS The contribution gives an overview of the body shape variation, interaction between body motion and clothing as shell, the role of ease allowance, and shows the grounded model development of the ease allowance for comfort and wearability. Ease allowance, as the difference in space between the clothing and the body, is an important criterion of wearing-comfort. Fashion threads affect the accepted amount of wearing ease, however, regardless of the design, the finely balanced ease allowance is imperative for clothing to fit and hang well on the body, and to allow necessary comfort and mobility to the wearer. Comprehensive investigations have been carried out in the field of anthropometry and in garment construction and design, and extensive results obtained, permitting the development of efficient methods for determining the required ease allowance for suitable comfort. However, advanced 3D computerised technologies and rapid development in virtual simulation in the garment industry (where not only the 3D shape of the garment is presented but also the mechanics of fabric behaviour), combined with an increase in the producing of made-to-measure garment, require still more flexible and precise methods of garment planning and determining adequate values for the ease allowance for comfort. New methods will have to be aimed at optimising garment design with precisely defined values of the ease allowance for comfort. They will have to be flexible enough and easily adaptable to human body morphology, which has changed considerably in the course of the last century, but they should also follow the requirement of the contemporary clothing market. 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Ng,, R., Yu, W., Cheung, L.F.: Single Parameter Model of Minimal Surface Construction for Dynamic Garment Pattern Design, Journal of Information and Computing Science, 2 (2) (2007b), 145-152. Kawabata, S.: The Standardization and Analysis of Hand Evaluation, 2nd Edition, The Hand Evaluation and Standardization Committee, Textile Machinery Society of Japan, Osaka Science & Technology Center Bld., Osaka, July 1980. Kawabata, S.: Kawabata, S., Niwa, M., Yamashita, Y. A Guide Line for Manufacturing Ideal Fabrics’, Proceedings of the 27th Textile Research Symposium at Mt. Fuji, Shizuoka, (1998), 349-355. Burgo, F.: Il Modellismo – Tecnica del modello sartoriale e industrial donna – uomo – bambino/a, Milano, Burgo Istituto professionale per la mode, 1998. 49 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 51-56, -Vanredno izdanje- САВРЕМЕНИ ТРЕНДОВИ ГРАФИЧКИХ ТЕХНОЛОГИЈА Драгољуб Новаковић5, Игор Карловић Факултет техничких наука, Графичко инжењерство и дизајн, Нови Сад ISSN 2232-755X DOI: 10.7251/GHTE13VI051N UDC 655.1/.3:621.9 Графичке технологије су изузетно пропулзивне технологије које прате савремене информатичке промене. Подручја развоја су везана за изузетно софистицирана истраживања од подручја нано технологија до савремених информатичких технологија. Интернет технологије у последњих неколико година развиле су нове трендове штампе која ће донети промене у индустрији штампе. Овим се мењају трендови и начин на који компаније послују од дизајна до штампе и завршних операција обраде. Светска економска криза утиче додатно на штампу и медије, посебно у традиционалним медијима (новине и комерцијална штампа), а отвара нове медијске канале за дистрибуцију. Графичка индустрија има посебан задатак у односу на све индустријске гране јер их промовише а у одређеним подручјима као што је графичка амбалажа даје им и најзначајнију компоненти – изглед. Дигитализација је мегатренд са великим могућностима за штампање амбалаже. У подручју развоја штампе прелази се из микро у нано подручје штампе. То само доказује да су иновације и технолошки продор и главна покретачка снага за економски раст и решавања проблема. Такође, постоји јасан тренд где се на писане речи све више репродукују кроз дигиталне мултимедијалне уређаје као што су таблети, а са друге стране штампа се све више користи за израду модела, са електронским штампаним колима и 3Дштампом.У раду ће сумирати најважније нови трендови и промене у графичким технологијама. Кључне речи: дигитална штампа, дигитализација, трендови УВОД Иновације и технолошки промене су главна покретачка снага за економски расти решавања проблема на нивоу држава. Технолошке промене се могу имплементирати у граничне оквире али оно што треба посебно нагласити је процес глобализације који захтева одређена структурна прилагођавања. Процеси се могу глобално посматрати на нивоу различитих индустријских грана које су међусобно технолошки повезане посебно развојем информатичких технологија. Једна посебна специфичност се везује за графичку индустрију као индустријску грану која је значајна за велики број различитих индустријских грана. Нпр. она амбалажом "облачи" производе дајући им њихов финални изглед који је често пресудан у пласману производа. Појава дигиталне штампе као нове технике штампе ствара нове могућности преноса информација и постаје техника за производњу роба и специфичнихпроизвода, и отвара нови сегмент штампе на готово свим физичким подлогама.Појава нових преносних уређаја као што су мобилни телефони, дигиталних уређаја за електронско издаваштво додатно проширује медијско тржиште, и омогућује дигитализују и пренос различитих врста података. Штампа амбалаже има изузетно стабилан и захтеван раст и развој уз примену нових технологија штампе, уз употребу тзв паметних технологија које дају информације о производима као што је активна и интелигентна амбалажа.За подручје амбалаже која прати производе, технике штампе и обликовања - дизајна, ће се усавршавати и мењати али дугорочно посматрано са аспекта процеса штампе само ће се још више проширивати због трендова потребе пласмана производа и проширења тржишта. Дизајн производа и захтеви који се пред њега постављају су увек добар показатељ шире и дубље промене у развоју производа и графичких процеса који су неминовни пратилац. Графичка индустрија је увек била покретач развоја почев од проналаска штампе која је омогућила ширење писмености до развоја нових амбалажних материјала као што је таласасти картон. Појавом интернета и нових информатичких технологија често се говорило о смањењу обима штампе, међутим трендови утрошка папира и графичких материјала у процесима штампе говоре супротно. То се догађало у свим преломним тренуцима појавом нових медија од проналаска радија, телевизије, рачунара, интернета. Подлоге за штампу су и даље остале дуготрајни и поуздан чувар записа. Развојем нових технологија брже су се развијали графички процеси али они се нису имплементирали значајнијом динамиком из разлога што су одређене технике штампе пратиле високовредне машине за чије замене су биле потребне значајније инвестиције што је успоравало процес промена. У временима економске кризе која погађа индустрију проблеми се преносе посебно на пратећу индустрију у смислу смањеног инвестирања, што се одражава и на графичку индустрију. Са овим је одвија и директан утицај на развој посебновисоковредних машина. У тим процесима долази и до смањења одређених потреба што утиче 5 Korespodentni autor: Dragoljub Novaković, Факултет техничких наука, Графичко инжењерство и дизајн, Нови Сад, e-mail: novakd@uns.ac.rs 51 Драгољуб Новаковић, Игор Карловић: САВРЕМЕНИ ТРЕНДОВИ ГРАФИЧКИХ ТЕХНОЛОГИЈА на развој машина погодних за мање тираже као што су машине дигиталне штампе и дигитализацију. Криза је значајно убрзала тренд консолидације графичке индустрије уиндустријски развијеним земљама. Доста се улажеу оптимизацију укупних процеса посебно развојем софтвера заснованих на праћењу свих радних токова. Одређена истраживања као што су истраживања Британске истраживачке асоцијације за графичку индустрију (1) највећи тренд раста имају амбалажни производи (слика 1) уз претпоставку трендова у наредном периоду. Слика 1. Процене прираштаја графичких производа према врсти производа Figure 1. Estimates of growth of graphic products by product type За очекивати је да ће доћи и до промена одређених техника штампе које ће пратити пораст одређених производа (слика 2). Процене указују на пораст потреба за амбалажом што ће резултирати значајнијим уделом флексо технике штампе. Слика 2. Удео и процене примене техника штампе Figure 2. Share and assessment of the implementation of printing techniques Значајан показатељ трендова развоја графичких технологија се представља на највећем светском сајаму графичке индустрије ДРУПА који се одржава сваке четврте године (последњи је одржан у мају 2012. године). У оквиру последње манифестације посебну пажњу је изазвао тренд ка примени нано технологија у графичким процесима. Технологија која је највише привукла пажњу је Ланда компаније (слика3). 52 Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 51-56, -Vanredno izdanje- Слика 3. ЛандаS10 nanographic штампа(Copiright HSPRmediji) Figure 3. LandaS10 nanographic print (Copyright HSPRmediji) Основа наноштампе је тзв. LandaNanoInk™ нанос боје који се састоји се од честица пигмента величине само неколико десетина нанометара који показују посебна својства у односу на светлост која омогућује процес виђења боје. Landa Nanographic процес штампе карактеришу ултра-оштре растерске тачкице значајно високе униформности, високог сјаја и верности упалети процесних боја. Добијена слика се преноси на одређене врсте подлога, премазане или непремазне подлоге, као и на амбалажне подлоге без потребе за претходном припремом.Nano Inkбоја се тренутно везује за површину, формирајући чврст,отпоран слој боје без потребе за додатним сушењем. Наравно да је ово нови изазов за развој и поређење квалитета отисака добијених одређеним техникама штампе посебно приказа које ова компанија упоређује техникама које су највише у употреби компарирањем растерске структуре отисака (слика 4). Слика4. Растерско поређење Nanographi и других техника штампања Figure 4. Raster comparison of Nanography and other printing techniques Трендови развоја графичких технологија могу се повезати са одређеним процесима свеукупног друштвеног развоја. Овај развој је условљен развијеношћу друштва у којем се разматра стање графичких технологија и графичке индустрије. Графичка индустрија дели судбину укупног друштвеног стања у којем је основна претпоставка друштвени напредак. Развој ће бити диктиран низом захтева који ће бити условљени одређеним претпоставкама које се могу синтетизовати кроз спиралу развоја (слика 5) у којој се могу извести одређене предпоставке: рашће стандард људи и са тим потребе за различитим графичким производима, рашће потребе за различитим производима а самим тим и конкуренција, потреба за различитошћу производа условиће развој производних система ка системима високе флексибилности, доминантну улогу у графичким системима ће преузети нове технологије, нове технологије ће захтевати нове високо образоване стручњаке, нови стручни људи ће донети нове идеје и наставити раст и развој. 53 Драгољуб Новаковић, Игор Карловић: САВРЕМЕНИ ТРЕНДОВИ ГРАФИЧКИХ ТЕХНОЛОГИЈА Слика 5: Претпоставке трендова развоја графичке производње у будућности Figure 5: The assumptions of the trends of graphic production development in the future Праћење и анализа тренутних економских интереса код инвестирања у нову опрему је важан корак који ће умногоме утицати на способност фирме у графичкој индустрији да остане конкуретна у брзим савременим тржишним условима. Препознавање нових трендова и технологија као стратешка одлука позиционирања мора да укључује добру одлуку о технолошкој инвестицији, пошто лош одабир технологије или чекање на неку технологију која је тек у развоју може да уназади пословање. Једно од решења је да се производ на тренутак измести из фокуса пажње, и да се она преусмери на произвођача опреме. Индентификација апликације која је потребна за профитабилну производњу, треба да садржи анализу произвођача опреме и њихов приступ тржишту и начину пословања. Важно је одабрати произвођача опреме који континуирано улаже у своје машине и који прави производе који подупиру реалне, а не пројектоване или замишљене тржишне потребе, и који може да пружи пуну подршку за дату апликацију. Последњих неколико година може се констатовати да је графичка индустрија претрпела доста промена од којих се могу издвојити: ДТП (Desk Top Publisching или стоно издаваштво) технологија је постала много софистициранија, Филм је доста брзо нестао са тржишта са развојем ЦтП (Computer to Plate или од компјутера до штампе), технологија, Офсетне машине постижу бржа припремна и производна времена, Дигиталне технологије штампе и уређаји су имали динамичан развој и пораст квалитета отисака, ДИ (DirectImage или директно осликавање) технологије су се развиле и усавршиле, Интернет револуција у графичкој индустрији је унапредила процесе, са настављањем убрзаног развоја, Пораст је тзв.онлине трговине и аутоматизације процеса, Порастао је утрошак папира за потребе штампе без обзира на раст електронских медија. У графичким процесима је присутна свеопшта компјутеризација графичке производње, са дигитализацијомскоро свих сегмената графичког процеса. Поред ове свеопште дигитализације неколико трендова је могуће индентификовати како за аналогне тако и за дигиталне технологије и то: 54 Напуштање стандардних формата штампе, Дигитално штампање из ролне са широком лепезом дигитланих техологија, Висока аутоматизација и интегрисани системи за завршну графичку обраду, Развој технологија за сушење отисака и предности додатногоплемењивања, Оптимизација решења у премедијима и штампарским радним токовима. Инкјет технологија добија нови замах са бројним побољшањима. Glasnik hemičara,tehnologa i ekologa Republike Srpske, (2013) 51-56, -Vanredno izdanjeКористи се у многим различитим графичким процесима, штампи амбалаже и индустријских производа од веома различитих врстао преме и материјала. Дигитална штампа којој припада и Инкјет, може бити корисна у заштити посебно на штампаној амбалажи, уз употребу УВ флуоресцентних компоненти које се стављају у боје. Графичка индустрија јеу потрази за новим могућностима. Штампа електронских кола и РФИД технологијасе постепено претварау аутентичну и поуздану опцију за идентификацију производа. 3Д штамп ашири своје могућности примене посебно у изради модела за доста широк спектар различитих производа. Електронско издаваштво публикација са развојем нових медија отвара нове корисничке навике. Са појавом мобилних уређаја и таблета, уз електронска издања класичних књига и часописа долазе нове промене. Продаја електронских књига је у порасту. Развој комуникационе технологије се креће ка повезаном свету путем рачунара. ДИСКУСИЈА Графичка индустрија у свакој развијеној земљи има значајно место у профиту који остварује. У земљама које пролазе транзициони период за очекивати јепозитиван тренд развоја и раста. Свака држава која жели бити на развијеном тржишту мора посветитипажњу развоју графичке индустрије јер је она са својим производима главни репрезент производаосталих индустријских грана.У примени графичких технологија за очекивати је интензивније инвестирање у нове технологије усвим фазама графичке производње од припреме, штампе и завршне графичке обраде.У свим фазама графичке производње до изражаја ће доћи стандардизација процеса. Наставиће серазвој формата штампе изван тзв. стандардних формата. Дигитална штампа ће наставити тренд примене и развоја посебно у подручју тиража којима ће се узимати део тржишта које сада припада неким другим техникама штампе. Иновације и истраживања у техникама штампе ће се продубити у подручју нано технологија са интеграцијом у информатичком развоју и аплицирању у процесе и машине. Примена ЦтП технологија ће постати доминантна. У завршојграфичкој обради ће се наставити интензивна аутоматизација ових система. Са развојем материјалаза оплемењивање отисака развијаће се нови уређаји и технике. Стандардизација у графичким процесима, радним токовима ће значајније ући у примену и даље развојне токове. Снага технологија и иновација указује на позитивне развојне трендовеграфичке индустрије. ЗАХВАЛНИЦА Истраживања представљена у раду су сегмент истраживања која се реализују у оквиру пројекта број 35027 "Развој софтверског модела за унапређење знања и производње у графичкој индустрији" које финансира Министарство просвете и науке Републике Србије. LITERATURА [1]AccuVal Associates: Industry Factors Weaken Printing Equipment’s Secondary Market (Online) Доступно на http://www.accuval.net/insights/featuredarticle/ detail.php?ID=65. (1.6.2013) [2]European Commission: EU Manufacturing Industry:What are the Challenges and Opportunities for the Coming Years? (Online) Доступно на http://ec.europa.eu/enterprise/policies/industrial-competitiveness/economic crisis/files/eu_manufacturing_challenges_and_opportunities_en.pdf (4.6.2013) [3]Flood A.:Huge rise in ebook sales offsets decline in printed titles , (Online) Доступно на http://www.guardian.co.uk/books/2012/may/02/rise-ebook-sales-decline-print-titles. (14.6.2013) [4]Messe Dusseldorf: drupa 2012 sends out Trendsetting Impulses for the Print Sector, press realase 16.05.2012 (Online) Доступно на http://www.drupa.de/cgi-in/md_drupa/custom/pub/content.cgi?lang= 2&oid=16479&ticket=g_u_e_s_t&ca_page=en%2F1410_4639.htm. (1.7.2013) [5]Nanowerk :Landa's Breakthrough Nanographic Printing Press Changes the Face of Mainstream Print Markets with Versatility of Digital and Qualities of Offset‖ (Online) Доступно на http://www.nanowerk.com/news/newsid=25272.php (4.7.2013) [6]Smyth S.:The Future of Inkjet Printing – post drupa review (Online) Доступно на http://whattheythink.com/articles/58279-future-inkjet-printing-post-drupa-review/. (4.7.2013) 55 Драгољуб Новаковић, Игор Карловић: САВРЕМЕНИ ТРЕНДОВИ ГРАФИЧКИХ ТЕХНОЛОГИЈА MODERN TRENDS IN GRAPHIC TECHNOLOGIES Dragoljub Novaković, Igor Karlović University of Novi Sad, Faculty of Technical Sciences, Department of Graphic Engineering and Design, Novi Sad Graphic technologies are highly propulsive technologies that accompany modern information changes. Areas of development are related to the highly sophisticated research areas, from nano technology to modern information technologies. Internet technology in recent years have developed new printing trends that will bring about changes in the press industry. These trends are also changing the way companies do business, from design to printing and final processing operations. The world economic crisis additionally affects the printing and the media, particularly in the traditional media (newspaper and commercial printing), and opens new media distribution channels. Printing industry has a special task in relation to all industries because it promotes them, and in certain areas such as the graphic packaging also gives them the most important component - appearance. Digitization is a mega trend with great possibilities for packaging printing. In the field of printing development we go from micro to nano print area. This only proves that innovations are both technological breakthroughs and a major driving force for the economic growth and problem solving. Also, there is a clear trend where the written word becomes increasingly reproduced by digital multi media devices such as tablets, and on the other hand, the press is being increasingly used for developing models, with electronic printed circuits and 3D printing. This paper will summarize the most important new trends and changes in graphic technologies. Keywords: digital printing , digitizing , trends 56 UPUTSTVO AUTORIMA 1. Glasnik hemičara, tehnologa i ekologa RS objavljuje radove koji podlijeţu recenziji i svrstavaju se u sljedeće kategorije: originalni naučni radovi kratka saopštenja prethodna saopštenja pregledni radovi stručni radovi izlaganja sa naučnih skupova Autori predlaţu kategoriju svojih radova, ali konačnu odluku o tome donosi Uredništvo na osnovu mišljenja recenzenata. Originalni naučni radovi sadrţe rezultate izvornih istraţivanja. Naučne informacije u radu moraju biti obraĎene i izloţene tako da se mogu eksperimenti ponoviti i provjeriti analize i zaključci na kojima se rezultati zasnivaju. Kratka saopštenja sadrţe rezultate kratkih ali završenih istraţivanja ili opise izvornih laboratorijskih tehnika. (metoda, aparata itd) Prethodno saopštenje sadrţi naučne rezultate čiji karakter zahtijeva hitno objavljivanje, ali ne mora da omogući provjeru i ponavljanje iznesenih rezultata. Pregledni rad predstavlja cjelovit pregled nekog područja ili problema na osnovu već publikovanih materijala koji je u pregledu sakupljen, analiziran i raspravljen Stručni rad predstavlja koristan prilog iz područja struke, a čija problematika nije vezana za izvorna istraţivanja. Stručni rad se odnosi na provjeru ili reprodukciju poznatih istraţivanja i predstavlja koristan materijal u smislu širenja znanja i prilagoĎavanja izvornih istraţivanja potrebama nauke i prakse. Kategorizacija naučnih i stručnih radova data je prema preporukama UNESKO-a Radovi svrstani u ove kategorije podlijeţu ocjenjivanju dvaju recenzenata. Recenzije su dvosmjerno anonimne, odnosno recenzentima se ne otkriva identitet autora i obratno. Rad će se objaviti jedino na osnovu pozitivnih recenzija , o čemu će Uredništvo obavjestiti autora. Recenzenti se biraju meĎu stručnjacima u neposrednom području istraţivanja na koja se odnosi rad predloţen za objavljivanje. U pravilu recenzent ne moţe biti autorov saradnik niti pretpostavljeni. 2. Glasnik hemičara, tehnologa i ekologa RS objavljuje radove koji ne podlijeţu recenziji: mišljenja i komentari prikazi i saopštenja iz prakse u obliku dopisa ili prevoda stranih članaka 3. Glasnik hemičara, tehnologa i ekologa RS moţe uključivati dodatke sa kongresa, savjetovanja ili simpozijuma. 4. Autor je u potpunosti odgovoran za sadrţaj rada. Uredništvo pretpostavlja da su autori prije podnošenja rada regulisali pitanje objavljivanja sadrţaja rada saglasno pravilima ustanove ili preduzeća u kojem rade. 5. Brzina kojom će se rad objaviti zavisiće o tome koliko rukopis (tekst) odgovara uputama. Radovi koji zahtijevaju veće prepravke ili dopune biće vraćeni autoru na preradu prije recenzije. UPUTSTVO ZA PISANJE RADOVA 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Rad se dostavlja Uredništvu časopisa elektronski (e-mailom ili na CD-u poštom) s tekstom pripremljenim isključivo pomoću programa za obradu teksta Microsoft Word. Ukoliko se rad šalje poštom, ispis rada zajedno sa CD-om poslati na adresu: Uredništvo "Glasnika hemičara, tehnologa i ekologa RS" Tehnološki fakultet, Vojvode Stepe Stepanovića 73, 51000 Banjaluka. Rad treba da ima najviše 10 strana i da sadrţi sljedeće dijelove na jednom od jezika Bosne i Hercegovine ili na nekom od priznatih evropskih jezika: naslov, spisak autora i ustanova, saţetak, uvod, materijal i metode rada, rezultati i diskusija, zaključak, literatura, naslov na engleskom jeziku, spisak autora i rezime na engleskom jeziku. Naslov rada pisati centrirano i velikim slovima (Times New Roman, 14 pt, bold, Caps Lock), autore pisati centrirano bez titule i sa nazivom ustanove (Times New Roman, 10 pt, normal). Podnaslove pisati centrirano, (Times New Roman, 12 pt, bold). Ostale dijelove rada treba pisati sa obostranim ravnanjem redova (Times New Roman, 12 pt), jednostranim proredom sa jednim praznim redom iznad, izmeĎu podnaslova i izmeĎu pasusa, sa marginama od 2.54 cm (1"). Početak pasusa kucati od početka reda. Saţetak treba da ima 100-250 riječi, a stoji izmeĎu zaglavlja rada (koji čini naslov rada, i podaci o autorima) i ključnih riječi, nakon kojih slijedi tekst rada. Ukoliko je rad napisan na maternjem jeziku, saţetak na engleskom jeziku se daje u proširenom obliku, kao tzv. rezime i treba da sadrţi do 500 riječi. Tabele uraditi u WORD-u, a grafike u EXCEL-u izuzev posebnih slučajeva kada to tehnički nije moguće, i treba da budu jasne, što jednostavnije i pregledne. Naslov, zaglavlja (tekst) i podtekst u tabelama i grafikama treba da budu napisani fontom Times New Roman – normal, Font Size 10 pt. Tabele se stavljaju na odreĎeno mjesto u tekstu. Tabele ne bi smjele sadrţavati više od deset okomitih kolona i više od petnaest vodoravnih redova. Ukoliko autor ocjenjuje da podatke mora prikazati u većem broju kolona i redova, potrebno je sadrţaj tabele podijeliti u dvije ili više manjih tabela ili je dostaviti u posebnom prilogu. Moraju se izraditi prema kompjutorskom predlošku (Insert Table), a ne pomoću razmaka, tački i tabulatora. Jednačine pisati u grafičkom editoru za jednačine, isključivo u Microsoft Equation i postaviti je na početak teksta. Na desnom rubu teksta, u redu na kojem je pisana jednačina, u zagradi treba naznačiti njen broj, počevši od broja 1. Fotografije moraju biti pripremljene za crno-bijelu štampu tj. ako je izvorna slika u bojama koje se u crno bijeloj štampi ne razlikuju, boje se moraju zamijeniti ―rasterom‖ tj. različitim grafičkim znakovima koje je potrebno objasniti u legendi. U slike se unosi samo najnuţniji tekst potreban za razumijevanje kao što su mjerne varijable s njihovim dimenzijama, kratko objašnjenje na krivuljama i sl. Ostalo se navodi u legendi ispod slike. Maksimalna veličina slike je 13 cm x 17 cm. Fotografije, crteţe, sheme (izvorni format faila - TIF, JPG sa 300 dpi, ili vektorski format sa slovima pretvorenim u krive – CDR) i grafikone, osim u tekstu na predviĎenom mjestu, dati i u posebnom prilogu. Radi uspješnog uključivanja radova objavljenim na jednom od jezika Bosne i Hercegovine u meĎunarodne informacione tokove, dijelove rukopisa treba pisati na jeziku autora i na engleskom jeziku, i to: tekst u tablicama , slikama, dijagramima i crteţima , njihove naslove i oznake. Pri slanju rada navesti i punu sluţbenu adresu, telefon i e-mail svih autora i naglasiti autora s kojim će Uredništvo saraĎivati. Ove obavjesti priloţiti na posebnom listu. Eksperimentalna tehnika i ureĎaji opisuju se detaljno samo onda ako znatno odstupaju od opisa već objavljenih u literaturi. Ukoliko su tehnike i ureĎaji poznati navodi se samo izvor potrebnih obavjesti. Simbole fizičkih veličina treba pisati kurzivom (Times New Roman, 12 pt. – italik), a mjerne jedinice uspravnim slovma, npr. V, m, p, t, T, ali m3, kg, Pa, 0C, K. Veličine i mjerne jedinice se moraju upotrebljavati u skladu sa MeĎunarodnim sistemom jedinica (SI). Literaturne citate numerisati onim redom kojim se pojavljuju u tekstu. Citati se u tekstu označavaju arapskim brojevima u zagradi ( ). Kratice za časopise moraju biti strogo u skladu sa kraticama kako ih navodi Chemical Abstract. Literaturu treba citirati na sljedeći način: Primjer citiranja naučnog časopisa: Moreno, S., T. Scheyer, C.S. Romano, A.A. Vojnov: Antioxidant and antimicrobial activities of rosemary extracts linked to their polyphenol composition. Free Radical Research, 40 (2) (2006) 223–231. Primjer citiranja knjige: Banks, W., and C.T. Greenwood: Starch and its Components, Edinburgh University Press, Edinburgh (1975) p. 98. Primjer citiranja poglavlja u knjizi: Fogarty, W. and C. Kelly: Pectic enzymes, in Microbial Enzyme and Biotechnology. Eds. Fogarty, W. Applied Science Publishers, London (1983) pp. 131-182. Primjer citiranja rada u zborniku: Ţabić, M., i Z. Kukrić: : Inhibicija aktivnosti tripsina ferocenom i njegovim derivatima, VIII Savjetovanje hemičara i tehnologa Republike Srpske, zbornik radova, Banjaluka, 27. i 28. novembar 2008., str. 75-84. Primjer citiranja magistarskih radova i disertacija: Petrović, R.: Dehidratacija etera na mordenitnim katalizatorima. Magistraski rad, Univerzitet u Banjaluci, Tehnološki fakultet, Banja Luka, 2001. Primjer citiranja patenta: Ehrenfreund J.: (Ciba Geigy A.–G.): Eur.Pat.Appl. 22748, 21 Jan (1981) 7078 Primjer citiranja web stranice: Environment Agency: Leachte Treatment (Online). Dostupno na: http://www.environment-agency.gov.uk/business/sectors/37063.aspx (19. 09. 2011.) Obavezno navesti datum citiranog podatka Neobjavljeni rezultati: Citiraju se sa jednim od sljedećih komentara "u štampi"; "neobjavljen rad"; "lična komunikacija" Radovi, koji nisu napisani striktno po ovom uputstvu, neće biti prihvaćeni za štamp
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