• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.635-638
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• 1999

The effect of proteolytic enzyme on the unhairing process has been studied. this enzyme significantly changed the physical properties of pelt for leather shoes. A SEM was used to examine physical properties of the pelt. Even though bio-tech treatment using proteolytic enzyme slightly reduced the degree of unhairing compared to chemical treatment. Physical property of the pelt is better and this method is environmentally favorable. $H_{2}S$ gas produced in the chemical treatment was not detected and the value of COD and BOD for waste water after the unhairing process were reduced to 939 mg/L and 5268 mg/L, respectively. We found that a process with 0.4~0.5% proteolytic enzyme for 20 h at $29{\sim}30^{\circ}C$ is most suitable for the unhairing process.

• Journal of Adhesion and Interface
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• v.6 no.2
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• pp.6-12
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• 2005

The plasma generally, ionized gas state, is the 4th material state composed the universe. Generating the plasma artificially has been studied by spending energy and it has a lot of applications in human's life. There are several merits to modify the surface of polymer using plasma. Above all, plasma maintains the property of polymer because of it changes the property of surface only. Also, it doesn't use a organic solvent and it is the environment friendship because of there are no waste under processing. Furthemore, in case of high-pressure plasma, it is possible that automated-processing continuously. In this study, we tried the reforming of surface to rise the adhesive strength between the material of polymer, experimented the rising of adhesive strength through a experiment of peel strength by virtue of processing time and using gas, confirmed the change of polymer's surface through measuring the surface contact angle analyzer and scanning electron microscopy (SEM).

• Journal of Fashion Business
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• v.20 no.2
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• pp.124-133
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• 2016

Currently the fashion industry is developing to create a novel culture due to the very sensitive and knowledge-oriented advancement of the IT industry. With fast turnover of information, consumers have come to have a more diverse desire for purchasing. Cubical expression techniques, which empathizes formativeness, can be a creative expression method adjusting into the trend of this era. Along with functional aspects of consumers, even in a textile manufacturing sector, new materials are required to meet sensitive and emotional aspects. Consumers' desire for new and creative designs and the development and adoption of new materials are essential to meet their emotions. The IT industry and fashion industry are forced to combine and a 3D apparel CAD system has been developed, enabling virtual clothing to be represented within a computer virtual space. All processes such as design, pattern creation, sewing and simulation are possible in 3D level. Digital clothing can shorten the production process time and is very effective in that it can reduce clothing waste generated during the sample production. This paper reviewed the works of Dutch designer, Iris van Herpen, who has developed formative designs. She tries to build, construct, and sculpt employing diversified materials other than soft textile materials, as shown in her series of fashion shows. The materials include films, 3D printed polymers, stiff and sheer organza, and artificial leather textiles. A few characteristics of her works have been selected in order to prepare patterns exhibiting the traits. The paper further focused on the physical features of the textile materials used to express similar techniques and its various forms were reviewed.

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.140-145
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• 2019

In view of environmental considerations, the control of carbon dioxide (CO₂) and volatile organic compounds (VOCs) is one of important issues in the film and coating industries. Therefore, UV-curable system has been developed due to minimize emissions of VOCs and reduce CO₂ emission due to low energy consumption from fast curing. Also, biodegradable polymers economically are attractive because of environmental and economic concerns associated with huge waste plastics. In this study, UV-curable polyurethane acrylates with different compositions of biodegradable polylactide (PLA) diol and poly(ethylene glycol) as diols were synthesized and curing reaction of their end-capped acrylates was performed by UV exposure. Tensile strength, elongation, and Tg of the UV-cured polyurethane acrylates increased with PLA diol content in the diol while their hydrophilicity and thermal stability increased with the PEG content. These results indicated a property of UV-cured polyurethane acrylates could be controlled by environment-friendly diols.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.70-79
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• 2022

Biodiesel production has attracted attention as a sustainable source of fuel and is a competitive alternate to diesel engines. The glycerol that is produced as a by-product is generally discarded as waste and can be converted to green chemicals such as acetins to increase bio-diesel profitability. Acetins find application in fuel, food, pharmaceutical and leather industries. Batch experiments and analysis have been previously conducted for synthesis of acetins using glycerol esterification reaction aided by sulfated metal oxide catalysts (SO₄^2-/CeO₂-ZrO₂). The aim of this study was to optimize process parameters: effects of mole ratio of reactants (glycerol and acetic acid), catalyst concentration and reaction temperature to maximize glycerol conversion/acetin selectivity. The optimum conditions for this reaction were determined using response surface methodology (RSM) designed as per a five-level-three-factor central composite design (CCD). Statistica software 10 was used to analyze the experimental data obtained. The optimized conditions obtained were molar ratio - 1:12, catalyst concentration - 6 wt.% and temperature -90 ℃. A packed bed reactor was fabricated and column studies were performed using the optimized conditions. The breakthrough curve was analyzed.

• Membrane Journal
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• v.33 no.3
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• pp.87-93
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• 2023

Electrodialysis (ED) is essential in separating ions through an ion exchange membrane. The disposal of brine generated from seawater desalination is a primary environmental concern, and its recycling through membrane separation technology is highly efficient. Alkali is produced by several chemical industries such as leather, electroplating, dyeing, and smelting, etc. A high concentration of alkali in the waste needs treatment before releasing into the environment as it is highly corrosive and has a chemical oxygen demand (COD) value. The concentration of calcium and magnesium is almost double in brine and is the perfect candidate for carbon dioxide adsorption, a major environmental pollutant. Sodium hydroxide is essential for the metal carbonation process which, is easily produced by the bipolar membrane electrodialysis process. Various strategies are available for its recovery, like reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and ED. This review discusses the ED process by ion exchange membrane for alkali recovery are discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.274-279
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• 2007

The toxicitiy of organic sludge such as municipal sewage sludge (MSS), industrial sewage sludge (ISS), alcohol fermentation processing sludge (AFPS) and leather processing sludge (LPS) were evaluated with three environmental biomarkers as acetylcholinesterase, cytochrome P450, and heat shock protein 70 extracted from earthworm (Eisenia fetida). Their toxicities were compared with those of pig manure compost (PMC). MSS, ISS, LPS, and AFPS did not significantly affect the acetylcolinesterase activity, whereas only the elutriate of PMC slightly was increased the activity. MSS, AFPS, and PMC tended to slightly inhibit the cytochrome $P_{450}$ activity, but ISS and LPS showed significantly the inhibitory effect on cytochrome $P_{450}$. The hsp70 expression began to increase after treatments and showed high induction at 6 hour, followed by zero level at around 12 hour. The quantity of the hsp70 expressed by elutriate treatments of PMC, AFPS, MSS, ISS, and LPS was 1.9, 3.0, 3.3, 4.4, and 4.7 fold higher than that of distilled water. These results indicate that in toxicity tests of five organic waste materials, four kinds of sludge materials appeared more toxic than PMC. Results of AChE, P450, and hsp70 of earthworm might be useful for expecting or assessing an effect by exposure of organic wastes to earthworms in soil.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.3
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• pp.13-22
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• 2022

In order to improve water quality of the water system contaminated with dyes, biochars prepared using discarded waste resources were applied in this study. Biochars with a large specific surface area were manufactured using street tree pruning products or waste wood, and were applied to remove an organic dye in synthetic water. Biochars were made by pyrolysis of typical street tree porch products (Platanas, Ginkgo, Aak) and waste wood under air-controlled conditions. Methylene blue (MB), which is widely used in phosphofibers, paper, leather, and cotton media, was selected in this study. The adsorption capacity of Platanas for MB was the highest and the q_max value obtained using the Langmuir model equation was 78.47 mg/g. In addition, the adsorption energy (E) (kJ/mol) of MB using the Dubinin-Radushkevich (D-R) model equation was 4.891 kJ/mol which was less than 8 kJ/mol (a criteria distinguishing physical adsorption from chemical adsorption). This result suggests a physical adsorption with weak interactions such as van der Waals force between the biochar and MB. In addition, the physical adsorption may resulted from that Platanas-based biohar has the largest specific surface area and pore volume. The ∆G value obtained through the adsorption experiment according to temperature variation was -3.67 to -7.68, which also suggests a physical adsorption. Considering these adsorption results, the adsorption of MB onto Platanas-based biochar seems to occur through physical adsorption. Overall, it was possible to suggest that adsorption capacity of the biochr prepared from this study was equal to or greater than that of commercial activated carbon reported in other studies.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.339-344
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• 2006

A lot of organic wastes have been produced from diverse industries, they must be tested by the regulation of fertilizer control act if reuse the organic wastes for agricultural utilization. The regulation has had only two criteria; the content of organic matter and 8 heavy metals. This study was conducted to evaluation trace element (boron, cobalt, molybdenum, and selenium) and distribution of organic compounds with different classification for complement the regulation in 16 organic waste materials(62 samples) collected from different regions and industries. Contents of boron(leather industry sludge, $154.2mg\;kg^{-1}$; food company sludge, $57.1mg\;kg^{-1}$), cobalt(industrial area sewage sludge, $95.2mg\;kg^{-1}$; metropolitan sewage sludge, $22.9mg\;kg^{-1}$), molybdenum(metropolitan sewage sludge, $40.1mg\;kg^{-1}$; food company sludge, $16.8mg\;kg^{-1}$), selenium (fiber industry sludge, $28.1mg\;kg^{-1}$; leather industry sludge, $16.9mg\;kg^{-1}$; food company sludge, $15.9mg\;kg^{-1}$) were highest compare to the other organic wastes. Total PAHs contents were the highest in paper-mill manufacture($3,462ug\;kg^{-1}$), and among the 16 PAHs, naphthalene, phenanthrene, pyrene, fluoroanthene, Anthracene and acenaphthene were detected more clearly than others in all kinds of organic resources.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.160-167
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• 2006

Harpacticoid copepod Tigriopus japonicus is widely distributed in coastal waters of Korea and plays important role in marine trophic structure as a first consumer. In this study, a series of experiment were conducted to test the potential of the species as a standard test species for marine bioassay. Tolerance on salinity and pH, sensitivity on the reference materials(copper sulfate and cadmium chloride) and response on the ocean dumping materials(waste sludge) we re tested to identify if the species satisfy the basic criteria as standard species for marine bioassay. The nauplius of the species($100{\sim}200{\mu}m$) showed wide tolerance on salinity with >90.0% survival rates exposed to $5.0{\sim}35.0psu$ for 48 h. Wide adaptability on pH's were also observed from 6.3 to 8.2 with >90.0% survival rates during the test. $LC_{50}$ values for copper sulfate and cadmium chloride were $3.6{\pm}0.7ppm,\;1.7{\pm}0.8ppm$, respectively. The variations in mortality between replicates were less than 10.0%. Comparison of $LC_{50}$ values indicated that T. japonicus nauplius was lower sensitive to copper sulfate than the most marine crustaceans included copepods, however, the sensitivity of test animal to cadmium chloride higher than the adults of copepod T. japonicus, Paracalanus parvus, and marine rotifer Brachinonus plicatilis. There were significant concentration-response relationship in the mortality of T. japonicus nauplius using the elutriates of three ocean dumping materials(industrial waste sludge). 48 h $LC_{50}$ values we re $31.1{\pm}1.1%$ for the elutriate of sludge from leather processing company and $54.4{\pm}15.1%$ for that of dye production company. Based on the above experimental results, bioassay using benthic harpacticoid T. japonicus nauplius must be a good estimation tool for marine ecotoxicological assessment of waste or chemicals. Wide tolerance on the salinity and pH, and significant linear relationship between concentration and response(mortality) supported the high potential of the species as a standard test species.