• Journal of Adhesion and Interface
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• v.3 no.3
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• pp.15-21
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• 2002

The modified polyethylene(m-PE) films were prepared from aqueous dispersions which were synthesized by reacting poly(ethylene-co-methylacrylate) with aqueous KOH and ammonia solution to attach -COOK, $CONH_2$, and COOH as pendent groups in the polyethylene backbones. Thermal, tensile and heat-seal properties were measured to investigate the effect of the pendent groups. Endothermic peaks on DSC curves were affected by the thermal history of the samples and a melting peak was observed at around $86^{\circ}C$ on the second heating curve while three melting peaks were shown on the first heating curve. A minimum value of tensile strength was shown at 70 mole% of COOK based on pendent groups. Tensile modulus increased with increasing the amide content in pendent groups. The m-PE films were heat-sealed at lower temperature than LDPE films and showed a minimum heat seal strength at around 70 mole% COOK content in pendent groups.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.206-210
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• 1984

Heat penetration pattern of canned oyster mushroom(Pleurotus astreatus) was monitored for processing variables-can size, heating temperature and solid fill fraction, and its effects on sterilization condition was reviewed. The $f_h$ value decreased sharply with decrease of solid fill fraction and then became stable from certain solid fill fraction unique to can size. Heat penetration was a little faster at higher heating temperature with lower $f_h$ value. As viewed from $f_h$ value, convection started at higher solid fill fraction with higher length/diameter ratio, and $f_h$ values decreased to about 1.0 with decrease of solid fill fraction. From standpoint of overall cost, retorting time and energy consumption, solid fill fraction of 3/5 was optimum for all can sizes considered.

• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.65-71
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• 2009

In this study, performance and economic analysis of natural gas/syngas fueled 100 MWth chemical-looping combustion (CLC) combined cycle plant were performed. Net efficiency of both cases was 53~54%, corresponding to previous research. We used Chemical Engineering Plant Cost Index and Guthrie method to evaluate plant cost. For syngas fueled CLC combined cycle plant, the plant cost was higher since lower heating value(LHV) of syngas was lower than that of natural gas and cost of electricity(COE) was also higher since the cost of syngas was higher than that of natural gas. By sensitivity analysis, it was shown that the cost of syngas should be less than 5.3 $/GJ in order to make COE lower than 5.8 ¢/kWh which was COE of natural gas fueled CLC combined cycle plant.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.527-532
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• 2015

This study was performed to investigate the phyico-chemical characteristics of breast meat from spent hens (SP) in comparison with the same part from the broilers (BR). The moisture and crude protein contents for SP were 72.56% and 24.26%, which were lower than 75.87% and 24.64% for BR. Crude fat and crude ash contents in SP were 0.45% and 1.00%, which were higher than the BR contents of 0.41% and 0.51%. The respective L, a and b value for SP were 48.61, 2.40 and 2.42, which were lower than the BR values of 49.41, 1.45 and 3.06 respectively. The pH for SP was 5.89, which was higher than pH 5.79 for BR. The WHC for SP was 50.29%, which was lower than that of BR at 62.31%. SP scored 28.04% in the heating loss test, which was significantly higher than 19.09% for BR. The shear forces for SP and BR were 4.86 kg and 1.36 kg respectively, which meant that the texture of SP was much tougher than that of BR. Hardness for SP was 8.89 kg while that of BR was 3.92 kg indicating that the SP texture is firmer than that of BR. Oleic acid was most abundant fatty acid in both samples and was at 44.15% in SP and 27.68% in BR.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.649-660
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• 2005

The effects of Lactobacillus buchneri 40788 and buffered propionic acid on preservation, intake and digestibility of alfalfa (Medicago sativa) and timothy (Phleum pratense) hay were investigated. During baling, forages were treated with L. buchneri 40788 (1.2${\times}$10$^6$ CFU/g) as a liquid (LLB) or as a granular preparation (GLB), with buffered propionic acid (10 mL/kg, BPA), or left untreated (control). Triplicate 500 kg round bales of each treatment were put up at two moisture levels for each forage: 17%${\pm}$0.33% and 20%${\pm}$0.30% for timothy and 17%${\pm}$0.20% and 19%${\pm}$0.27% for alfalfa (mean${\pm}$SD). Bales were sampled for chemical and microbiological analyses after 0, 30 and 60 d of storage. Compared to controls, all preservatives reduced (p<0.05) heating of both forages at all moisture levels with the exception of alfalfa baled at 19% moisture. After 60 d of storage, GLB reduced (p<0.05) moulds in 17% timothy hay as compared to other treatments, but at 20% moisture, moulds were reduced in LLB- and BPA-treated timothy as compared to controls. In alfalfa at 17% moisture, total bacteria were lower (p<0.05) in GLB-treated bales than LLB or control bales, but yeast and total bacteria were only reduced in BPA-treated alfalfa at 19% moisture. In situ DM disappearance of timothy (both moisture levels) and alfalfa (19% moisture level) increased (p<0.05) with LLB treatment compared to control. Digestibility of both forages did not differ (p>0.05) among treatments, however, voluntary DM intake of LLB-treated timothy (1.32 kg/d) was 22.3% higher (p<0.05) than control, and 14.1% higher than BPA-treated timothy. Treating timothy and alfalfa hay with L. buchneri 40788 or buffered propionic acid may improve the nutritive value of the hay when baled at 17 to 20% moisture.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.2
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• pp.53-61
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• 2023

Most of the sewage sludge is organic waste containing a large amount of organic substances decomposable by microorganisms by biological treatment. As for existing sewage sludge treatment methods, reduction and fuel conversion are being carried out using technologies such as drying, incineration, torrefaction, carbonization. However, the disadvantage of high energy consumption has been pointed out as latent heat of 539 kcal/kg is consumed based on drying. Therefore, in this study, we intend to produce solid fuel through hydrothermal carbonization(HTC), which is a thermochemical treatment. To evaluate the value of solid fuel, the characteristics of carbonization and fuel ratio were analyzed. As a result, as the hydrothermal carbonization reaction temperature increased, the lower heating value also increased by about 500 kcal/kg due to the increase in the degree of carbonization. H/C, O/C, ratio showed a decreasing trend from 1.78, 0.46 to 1.57, 0.32. When the ratio of ash to combustible content (fixed carbon + volatile) of dry sludge was 0.25 or more, it was derived that the degree of carbonization and calorific value did not increase even when hydrothermal carbonization was performed.

• Food Science and Preservation
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• v.11 no.2
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• pp.195-200
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• 2004

Microbial lethal value and nutrient retention of sous vide processed spinach were evaluated with mathematical model prediction and experimental trial for different package sizes and pasteurization temperatures. The package size covers 500 g, 1 kg and 2 kg, while the pasteurization temperature includes 80, 90 and 97$^{\circ}C$. The basic process scheme consists of filling blanched spinach into barrier plastic film pouch, sealing under vacuum, pasteurization in hot water with over pressure and final cooling to 3$^{\circ}C$. Pasteurization condition was designed based on attainment of 6 decimal inactivation of Listeria monocytogenes at geometric center of the pouch package by heating cycle, which was determined by general method. Heat penetration property of the package and thermal destruction kinetics were combined to estimate the retention of ascorbic acid and chlorophyll. Smaller packages with shorter pasteurization time gave better nutrient retention, physical and chemical qualities. Larger package size was estimated and confirmed experimentally to give higher pasteurization value at center, lower ascorbic acid and chlorophyll contents caused by longer heat process time. Lower pasteurization temperature with longer process time was predicted to give lower pasteurization value at center and lower ascorbic acid, while chlorophyll content was affected little by the temperature. Experimental trial showed better retention of ascorbic acid and chlorophyll for smaller package and higher pasteurization temperature with shorter heating time. The beneficial effect of smaller package and higher pasteurization temperature was also observed in texture, color retention and drip production.

• Fibers and Polymers
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• v.7 no.4
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• pp.333-338
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• 2006

Silk fibroin (SF) fiber from the Antheraea pernyi silkworm was treated with a 1.23 N iodine-potassium iodide ($I_2-KI$) aqueous solution, and the structure and physical properties were investigated to clarify the effects of the iodine treatment. The noticeably high weight gain value of SF fiber, about 25 wt% was attributed to the absorption of polyiodide ions in the form of $I_3{^-}\;and\;I_5{^-}$. Fourier transform infrared spectroscopy and X-ray diffraction measurements suggested that polyiodide ions mainly entered the amorphous region. In addition, a new sharp reflection on the meridional direction, corresponding to a period of $7.0{\AA}$, was observed and indicated the possibility of the formation of mesophase structure of ${\beta}$-conformation chains. Dynamic viscoelastic measurements showed that the damping tan ${\delta}$ peak at $270^{\circ}C$ gradually shifted to lower temperature in the iodinated SF fibers, suggesting an enhancement of the molecular motion of the fibroin chains induced by the presence of polyiodide ions. With heating above $254^{\circ}C$, the iodine component introduced intermolecular cross-linking of SF, and the melt flow of the sample was inhibited. The thermal decomposition stability of fibroin molecules was greatly enhanced by iodine treatment.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.59-61
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• 2001

Electrostatically actuated test devices were designed to evaluate the elastic modulus of single crystalline Si (100) materials for MEMS device. Elastic modolus was calculated from resonant frequency by applying Rayleigh's energy method. Temperature effect on elastic properties was evaluated by detecting the resonant frequency change with increasing temperature to $600^{\circ}C$. The elastic modulus was decreased with heating and then increased with cooling, but specimen with thermal cycle showed a permanent change which is lower than the initial value. This phenomenon was explained by the change of interatomic force and the formation of $SiO_2$ layer on Si. The thickness of oxide layer was estimated by considering the change of mass and stiffness, and the formation of oxide layer was observed by the SEM photograph.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.113-117
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• 1994

The effect if heat treatment (autoclave) in amino acid digestibility of winged bean determined using intact cockerels had been investigated. The winged beans were autoclaved at $120^{\circ}C$ for 45 or 90 min, respectively, and the soybean were autoclaved for 45 min. The treated winged bean and soybean were fed to 3 intact cockerels, which had been previously starved for 24 h. Excreta were collected individually for 49 h. The amino acids contained in the diets and excreta were determined to measure the digestibility values. Apparent and true digestibilities of all amino acids except histidine of unheated winged bean were significantly (P < 0.05) lower than those of heated winged bean and soybean. Heat treatment significantly (p < 0.05) improved amino acid digestibility of winged bean, However, over heating (90 min if autoclaving) destroyed lysine, cystine and arginine of winged bean. The true digestibility values of all amino acids of winged bean heated for 90min were the same as those values of treated soybean. However, true digestibilities of glycine, alannine, phenylalanine and lysine of treated soybean were significantly (p < 0.05) higher than those of winged bean heated for 45 min.