• Korean journal of food and cookery science
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• v.28 no.2
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• pp.111-121
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• 2012

The purpose of this study was to investigate the quality characteristics of Garaedduk with regard to the amount of added whole soybean curd (Chun-Tofu). Whole soybean curd was added in amounts of 0, 3, 6 and 9%. Whole soybean curd Topokki dduk was stored at room temperature for 48 hours. The moisture contents had no significant difference for increases in the amount of whole soybean curd. The L value and b values of Garaedduk increased significantly with increases in the amount of whole soybean curd. Texture characteristics of Garaedduk measured with a texture analyzer revealed that hardness and cohesiveness decreased significantly for different amounts of whole soybean curd, and hardness increased significantly and cohesiveness and chewiness decreased with increase of storage time. As for sensory characteristics, samples with 9% added whole soybean curd rated higher in overall acceptability compared with other samples. In regard to cooking properties, water absorption increased and solid contents decreased with increases in the amount of whole soybean curd. Therefore, Garaedduk containing 9% whole soybean curd was most preferable.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.73-79
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• 2017

Maleic anhydride (MAH) grafted polypropylene (PP-g-MAH) copolymers were prepared by changing MAH and styrene monomer (SM) content, using a twin screw extruder at $190^{\circ}C$. The grafting degree was measured by non-aqueous back titration method. The grafting degree of PP-g-MAH-SM copolymer was higher than that of PP-g-MAH at the same MAH content. PP-g-MAH-SM/kenaf fiber (KF) composites were also prepared by using a PP-g-MAH as a matrix at $200^{\circ}C$ and the KF content was fixed at 20 wt%. Based on the degradation temperature investigated by TGA, the thermal stability of PP-g-MAH-SM/KF composites was more enhanced than that of PP-g-MAH only. Mechanical properties of the composites were also improved when MAH and SM applied together. The adhesion degree between the copolymer and KF was confirmed by both SEM pictures of the fractured surface and contact angles.

• Polymer(Korea)
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• v.33 no.4
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• pp.358-363
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• 2009

Maleic anhydride-grafted polypropylene has been widely used to improve the interfacial interaction between the components in PP/polar polymer blends and PP/filler composites and to maximize the physical properties and thermal properties. In this paper. the maleic anhydride (MAH)-grafted polypropylene (co-PP) was fabricated through reactive extrusion process with di-cumyl peroxide (DCP) as an initiator. The grafting degree of MAH depending on the contents of DCP and MAH was investigated by FT-IR spectra and chemical titration. The grafting degree increased with increasing MAH concentration and also showed maximum value at 0.06 wt% of DCP concentration. Melt flow index (MFI) of the grafted copolymer was increased with increasing the contents of MAH. The DSC and TGA analysis data indicate the melting temperature and thermal degradation of PP depending on the grafting degree of MAH.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.115-123
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• 1993

Mechanically deboned chicken meat(MDCM ) from necks and backs was blended with 0.1% oleoresin rosemary, 0.1% oleoresin sage and 0.05% rosemary combined with 0.05% sage to evaluate retardation of oxidative rancidity during storage at$3^{\circ}C$ and $-25^{\circ}C$, respectively. 1. Moisture content of MDCM was 66.3%. protein 17.6%, fat 15.0% and ash 1.10%. Several types of bone particles such as angular and needle like shape in MDCM were observed by light microscope. 2. Lipid oxidation of MDCM started to increase after 2 day and increase rapidly after 6 day of storage at $3^{\circ}C$. Oleoresin sage and rosemary apparently retarded oxidative rancidity of MDCM during refrigerated and frozen storage, TBA and total carbonyl values demonstrated that sage was more effective antioxidant than rosemary, and sage /rosemary combination was the most effective antioxidant among them. 3. The oxidative rancidity of MDCM apparently accelerated after 50 days of storage at $-25^{\circ}C$. The addition of oleoresin sage and rosemary inhibited oxidizing changes stored for 100 days at -$25^{\circ}C$.

• Membrane Journal
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• v.22 no.1
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• pp.8-15
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• 2012

Tubular $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ membranes with $La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$ porous coating layer were prepared by extrusion and dip coating technique. XRD and SEM result showed the tubular membrane possessed the perovskite structure and porouscoating layer (thickness= about $2{\mu}m$) in surface. The oxygen permeation test was measured at condition of ambient air (feed side) and vacuum (permeate side) in the temperature range from 750 to $950^{\circ}C$. The oxygen permeation flux of $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ tubular membrane with $La_{0.6}Sr_{0.4}Ti_{0.3}Fe_{0.7}O_{3-{\delta}}$ porous coating layer reached maximum $3.2mL/min{\cdot}cm^2$ at $950^{\circ}C$ and was higher than non-coated $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ tubular membrane. Long-term stability test result indicated that the oxygen permeation flux was quite stable during the 11 day.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.1
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• pp.51-57
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• 2023

Because of the global pollution caused by plastic disposal, demand for eco-friendly transformation in the packaging industry is increased. As part of that, the utilization of polylactic acid (PLA) as a food packaging material is increased. However, it is necessary to improve the crystallinity of PLA by adding nucleating agents or to improve the modulus by adding fillers because of the excessive brittleness of the PLA matrix. Thus, the cellulose nanofiber (CNF) was fabricated and dried to obtain a powder form and applied to the CNF/PLA nanocomposite. The effect of CNF on the morphological, thermal, rheological, and dynamic mechanical properties of the composite was analyzed. We can confirm the impregnated CNF particle in the PLA matrix through the field emission scanning electron microscope (FE-SEM). Differential scanning calorimetry (DSC) analysis showed that the crystallinity of not annealed CNF/PLA nanocomposite was increased approximately 2 and 4 times in the 1st and 2nd cycle, respectively, with the shift to lower temperature of cold crystallization temperature (T_cc) in the 2nd cycle. Moreover, the crystallinity of annealed CNF/PLA nanocomposite increased by 13.4%, and shifted T_cc was confirmed.

• Composites Research
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• v.36 no.2
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• pp.126-131
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• 2023

Growing environmental concerns regarding pollution caused by conventional plastics have increased interest in biodegradable polymers as alternative materials. The purpose of this study is to develop a 100% biodegradable nanocomposite material by introducing organic nucleating agents into the biodegradable and thermoplastic resin, poly(lactic acid), to improve its properties. Accordingly, cellulose nanofibers, an eco-friendly material, were adopted as a substitute for inorganic nucleating agents. To achieve a uniform dispersion of cellulose nanofibers (CNFs) within PLA, the aqueous solution of nanofibers was lyophilized to maintain their fibrous shape. Then, they were subjected to primary mixing using a twin-screw extruder. Test specimens with double mixing were then produced by injection molding. Differential scanning calorimetry was employed to confirm the reinforced physical properties, and it was found that the addition of 1 wt% CNFs acted as a reinforcing material and nucleating agent, reducing the cold crystallization temperature by approximately 14℃ and increasing the degree of crystallization. This study provides an environmentally friendly alternative for developing plastic materials with enhanced properties, which can contribute to a sustainable future without consuming inorganic nucleating agents. It serves as a basis for developing 100% biodegradable green nanocomposites.

• Korean Journal of Legislative Studies
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• v.26 no.3
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• pp.125-159
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• 2020

Amid global pandemic of covid-19, Korean government's response has drawn wide attention among social scientists as well as medical studies. The role of Korean state and civil society has attracted particular attention among others. Yet, this paper criticizes extant studies on Korean case which focus on the extensive intervention of the strong state and subjective attitude of Korean citizens in coping with covid-19. The concept of the strong state lacks social scientific specification and subjective citizens do not match with Korean realities. This article argues that Korean state's capacity in collecting and mobilizing digital data may offer better understanding for the successful responses to the pandemic. First, Korean state is the ultimate coordinator in collecting, analyzing and applying big data about the expansion of covid-19 with its huge network of dataveillance. Also, such role has been largely based upon relevant legal framework and well prepared manuals and cooperation with civic actors and companies. In other words, Korean digital dataveillance had demonstrated its transparency and cooperative governance. Second, such dataveillance capacity has deep roots in the long-term development of Korean state's big data management. Korean state has evolved about thirty years while enhancing digital data network within governments, companies and private sectors. Third, the relationship between Korean state's dataveillance and civil society can be characterized as a state centered push model. This model demonstrates highly effective governmental responses to covid-19 crisis but fall short of building social consensus in balancing individual freedom, human rights and effective containment policies. It means communitarian solidarity among citizens has not been a major factor in Korea's successful response yet.

• Food Science and Preservation
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• v.30 no.5
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• pp.875-884
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• 2023

In this study, the quality characteristics of texturized vegetable proteins (TVP) produced from defatted soy flour (DSF) were analytically compared with those of texturized vegetable proteins produced with isolated soy protein (ISP) and non-defatted soy flour (SF). The base raw material formulation consisted of 50% soy proteins, 30% gluten, and 20% corn starch. A cooling die-equipped extruder was used with a barrel temperature set at 190℃ and screw rotation speed of 250 rpm. With respect to the hardness of isolate soy proteins, that of soy flour and defatted soy flour was 22.4% and 68.8%, respectively, and gumminess was 17.6% and 44.3%, respectively. Defatting increased chewiness, shear strength, and springiness. Moisture content was higher in soy flour than in defatted soy flour, while there were no significant differences in terms of water absorption and turbidity. The pH was higher with soy flour than with defatted soy flour. Concerning color, the L and b values were higher with soy flour, while the a value was higher with defatted soy flour. These results suggest that defatting soybeans can improve the quality of plant-based proteins. Further research is needed to address the quality differences from those of isolated soy proteins.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.65-71
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• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.