• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.77-83
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• 2014

The purpose of this study was to figure out the impacts of iron oxide types and dosages to bloating when producing artificial lightweight aggregates by utilization of recycled resources such as bottom-ash, reject-ash and dredgedsoil. In order to figure out chemical characteristics of raw materials, XRD and XRF analyses were performed. 50 wt% of dredged-soil, 15 wt% of bottom-ash and 35wt.% of reject-ash were mixed, then the amount of iron oxide was varied at 5 to 30 wt% with intervals of 5 wt% with $Fe_2O_3$ and $Fe_3O_4$ respectively. As molded aggregates were sintered by rapid sintering in intervals of $40^{\circ}C$ from $1060^{\circ}C$ to $1180^{\circ}C$, specific gravity and water absorption were measured. As a result, the artificial lightweight aggregate with iron oxide of 10~15 vol% showed the lowest specific gravity, and it was identified that the more iron oxide vol% increases, the more specific gravity increases because of liquid phase sintering.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.199-204
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• 2015

In this study, prevention methods of radial cracks generated inside of artificial lightweight aggregate made of reject ash and dredged soil were investigated. The reject ash and dredged soil had mixed with weight ratio of 7 : 3 and formed to spheric shape of 5~20 mm diameter, then, the aggregates were manufactured using flash sintering method at $1200^{\circ}C$ for 10 min. The formation of radial cracks in the aggregates were suppressed as the size of specimen decreased. Also, the addition of silica to aggregates had prevented generation of the radial cracks. As the size and the amount of silica powder added increased, the development of radial cracks was constrained. Therefore the artificial lightweight aggregate manufactured in this study expected to be applicable to many fields such as construction and environmental usages. Also it is expected to contribute greatly to increase the recycling rate of reject ash and dredged soil.

• Journal of Life Science
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• v.24 no.8
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• pp.851-859
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• 2014

The present study was designed to investigate whether ethanol extracts of Sophora flavescens (GS), Glycyrrhiza uralensis (GC), Dictamnus dasycarpus (BSP), and their mixtures (GGB-1, -2, -3, and -4) inhibit 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in a mouse model. DNCB was topically applied on the dorsal surface of Balb/c mice to induce AD-like skin lesions. The pathological phenotypes of AD, such as erythema, ear thickness, edema, scabs, and discharge, were significantly decreased in the GGB (DNCB + GS:GC:BSP = 3:1:1 mixture)-1-treated groups compared with the other treated groups. The weight of the spleen in immune organs was significantly decreased in the GGB-1-treated groups, whereas the weight of the liver in a control group was similar to that of the groups treated with the samples. Furthermore, toluidine blue staining analysis, a method used to specifically identify mast cells, showed that master cell infiltration into the dermis of the GGB-1-treated group was significantly decreased. The immunoglobulin E concentration was lower in the GGB-1-treated group. In addition, the levels of inflammatory cytokines (interferon-${\gamma}$, interleukin-1, 4, 5, 6, and 13, $1{\beta}$, and tumor necrosis factor-${\alpha}$) were also significantly reduced in the GGB-1-treated group. Taken together, these results suggest that a mixture of GS, GC, and BSP in a proportion of 3:1:1 (GGB-1) may contribute to the relief of AD symptoms and may be considered an excellent candidate for an AD therapeutic drug.

• Journal of Life Science
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• v.12 no.6
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• pp.661-668
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• 2002

We investigated the effect of tea fungus/kombucha beverage(TF) on the body weights, the blood glucose levels, lipid and protein concentrations, and enzyme activities in diabetic female rats. Sprague-Dawley rats were fed drinking water supplemented with 20% or 40% TF groups, respectively for 7 weeks. The female rats (mean weight 155.5$\pm$9.3 g) were assigned to one control and three diabetic groups. Diabetic groups were divided into diabetic control (TF free water), 20% or 40% TFD groups (20% or 40% TF in water) according to the levels of TF supplementation. Diabetes was experimentally induced by intraperitonially administration of streptozotocin in citrate buffer(pH 4.3) after 2 weeks feeding of four experimental water. Animals were sacrificed at the 5 weeks of diabetic state. The diabetic groups showed significantly decrease of body weight(6.8-7.5 g) compared with the control group(48.3 g). The hepatic, kidney and pancreatic weights of 20% or 40% TFD groups were not significantly different with D-control group. The fasting serum glucose level were higher in all diabetic groups than that of the control group. The concentrations of serum triglyceride in 40% TFD group and serum LDL-cholesterol in 20% TFD group were significantly decreased compared with the D-control group. The concentrations of serum total cholesterol and HDL-cholesterol, HDL-cholesterol/total cholesterol ratio, and atherogenic index in 20% or 40% TFD groups were similar to those in D-control group. The concentrations of hepatic triglyceride in 20% or 40% TFD groups were significantly decreased compared with the D-control group, but the concentrations of hepatic cholesterol and phospholipid were similar to all diabetic groups. The concentrations of serum and hepatic total protein, serum albumin, and the activities of GOT, GPT and LDH in the serum were the same levels of all diabetic groups.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1999.06a
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• pp.97-117
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• 1999

This study was performed to investigate the effect of pork on the cadmium detoxification in rats. Ninety male Sprague-Dawley rats weighing $125.3{\pm}1.4g$ were divided into five groups based on cadmium treatment(0, 25, 50, 100, 250ppm) and five levels of Cd in AIN-76 purified diet had been fed for 8 weeks. Cadmium was supplemented with a form of $CdCl_2$.. During following 8 weeks of intoxication, casein was replaced by pork and the effect of pork on cadmium- detoxification was compared with casein. After 8 weeks of Cd intake had resulted in apparent cadmium intoxication; reduced growth rate, enlarged kidney and testis, decreased hematocrit value and hemoglobin content in response to the supplemented Cd levels in the diets. Discontinuing cadmium feeding, the body weights were relieved. Pork-fed groups seemed to have higher body weight than casein-fed groups. Hemoglobin content and hematocrit value became normal range at detoxification stage. The weights of liver, kidney, and testis were decreased along with cadmium intake. However, organ weight ratio was not affected by cadmium. Cadmium accumulation in liver and kidney showed a tendency to increase in the cadmium-exposed groups. The levels of metallothionein were also significantly elevated in the tissues of liver in response to the levels of Cd supplemented(p<0.05). Cadmium concentration in kidney was two times higher than that in liver. Cadmium removal rate of liver was higher than that of kidney. Cadmium accumulation of the pork-fed group was lower than that of casein. Especially, the factors which affected the cadmium contents in kidney were $Cd^{***}$ and $Cd{\times}pork^{***}$. Metallothionein(MT) was increased with cadmium, and MT was not likely to be affected by pork. Based on the findings from gross lesion, rats fed 250ppm of Cd were externally emaciated, had exposed penis and observed atrophies of kidney and testis. Histopathological observation seemed that the liver of groups feeding Cd supplemented diets showed cellular degeneration and accumulation of eosinophilic materials in the capillaries. In kidney, rats fed Cd diets had shown tubular epithelium degeneration and lesions of basophilic materials, while testis were weakened in numbers of spermatid and sporadically enlarged of giant cells. But the rats administered cadmium-detoxified diet supplemented pork for 7 weeks were shown individually decreased lesions compared with the rats supplied with casein diet.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.332-338
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• 2000

This experiment was conducted to investigate the effects of feeding with MS (miraculous soil-bacteria)-fermented food waste on feeding efficiency and meat quality of mallard. Twenty one heads of 12 weeks-old mallards were fed with three different mixing rates of MS-fermented food waste (0, 20 and 50 %) with 7 replicates. After 6 weeks of feeding, weight gain and feed intake were measured to estimate feeding efficiency, moreover physico-chemical characteristics, amino acids and fatty acids of the fresh slaughtered mallards were analyzed to determine meat quality. The feeding efficiency of 0 % fermented food waste (control) was significantly (p<0.05) higher than other treatments. Water holding capacity and pH were not significantly differed. The color value in lightness of control meat was higher, while in redness was lower than that of the plots mixed with fermented food waste. Total content of amino acids in thigh meat was relatively lower in control, but that in breast meat showed a reverse trend. The amount of unsaturated fatty acids in both thigh and breast meat was the highest in the 50 % mixed plot. Considering economic and environmental aspects for mallard feeding, this results indicated that MS fermented food waste could be a useful resources for mallard feed.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.80-86
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• 2009

In this study, binderless zeolite BaX granule, an effective adsorbent for the separation of p-xylene was made. This adsorbent which has a sufficient strength, high specific surface area and selectivity to p-xylene was prepared by various steps, such as granulation process, calcination, binderless treatment, ion-exchange, and activation. In the granulation, the concentration of colloidal silica solution was controlled in order to confirm the effect of $SiO_2$ contents after binderless treatment. As a result, we confirmed that the compressive strength of granule after binderless treatment was increasing with increasing proportion of $SiO_2$ in the granule. And then Na-ion in granule was exchanged with Ba-ion by successive batch ion-exchange process. And then prepared adsorbents were tested for p-xylene separation by batch adsorption at $90^{\circ}C$. As a results of batch adsortion test, we confirmed that prepared adsorbents have a high selectivity to p-xylene. Also, it could be conformed that the prepared binderless zeolite BaX has a sufficient compressive strength (0.450 kgf), high specific surface area $(647.57m^2/g)$, high crystallinity (98.5% compared with zeolite NaX powder), and selectivity to p-xylene.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.346-346
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• 2007

압전세라믹 재료는 현재 압전 변압기, actuator, transducer, sensor, speaker 등에 광범위하게 이용이 되고 있다. 이 중에서 압전세라믹 소결체를 이용한 스피커의 제조는 가공이 까다롭고, 대형의 크기로 제작 시 소자가 깨지는 등의 많은 제약을 받고 있으며, 저음 특성이 떨어져 응용 범위가 한정되어 있다. 따라서 최근에는 이러한 단점을 극복하기 위하여 세라믹/고분자 복합체를 이용한 필름 스피커를 제작하고자 시도하고 있다. 이러한 세라믹/고분자 0-3형 압전 복합체를 이용할 경우, 제품의 경량화를 실현할 수 있고, 크기나 환경의 영향을 거의 받지 않으므로, 고기능성 스피커로의 응용에 적합할 것으로 보인다. 따라서 본 연구에서는 PZT계의 세라믹와 PVDF, PVDF-TrFE, Polyester, acrylic resin 등의 여러 고분자 물질과의 복합체를 제조하여 압전특성을 평가하였다. 본 실험은 먼저 $(Pb_{1-a-b}Ba_aCd_b)(Zr_xTi_{1-x})_{1-c-d}(Ni_{1/3}Nb_{2/3})_c(Zn_{1/3}Nb_{2/3})_dO_3$ (이하 PZT라 표기)의 최적화 조성을 선택하여, $1050^{\circ}C$에서 소결된 분말을 48시간 ball milling방법 로 약 $1{\mu}m$ 크기로 분쇄하였다. 고분자 물질들은 알맞은 용제들을 선택하여 녹였다. 그 다음 소결된 PZT분말과 고분자를 50:50, 60:40, 65:35, 70:30등의 무게 분율로 혼합하고, 분산제, 소포제 등을 첨가하여 3단 roll mill을 이용하여 충분히 분산시켜 페이스트 (Paste)를 제조하였다. 제조된 페이스트를 ITO가 코팅된 PET필름 위에 스크린 프린팅 법을 사용하여 인쇄하여 $120^{\circ}C$에서 5분간 건조하였다. 코팅된 복합체의 두께는 약 $80{\mu}m$ 정도로 측정되었다. Ag 페이스트를 이용한 상부 전극 형성에도 스크린 프린팅 법을 적용하였다. 이를 $120^{\circ}C$에서 4 kV/mm의 DC 전계로 분극 공정을 수행한 후 전기적 특성을 평가하였다. 유전특성을 조사하기 위해서 LCR meter (EDC-1620)를 사용하였고, 시편의 결정구조는 XRD (Rigaku; D/MAX-2500H)을 통해 분석하였으며, 전자현미경(SEM)을 이용하여 미세구조를 분석하였다. 압전 전하상수$(d_{33})$ 값은 APC 8000 모델을 이용하여 측정하였다. PZT의 혼합비가 증가할수록 비유전율 및 압전 전하 상수 등의 전기적 특성이 증가되었다. 또 여러 고분자 물질 중에서 PVDF-TrFE 수지가 가장 우수한 특성을 보였다. 이는 PVDF-TrFE 수지가 압전성을 나타내기 때문인 것으로 판단되었다.

• The Korean Journal of Soil Zoology
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• v.7 no.1_2
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• pp.17-21
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• 2002

Food waste which had been mixed with night soil sludge and composted for 21 days (mixing ratio = food waste/paper mill sludge : 1, w/w) was supplied to the 5 g of Eisenia fetida popualtion at various temperatures (5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 31, 32, 33, 34, 35$^{\circ}C$). The biomass of earthworms one month after feeding at 20-32$^{\circ}C$ was about two times more than that of the introduced earthworms, increasing rate of which was much higher than them at the other tested temperatures . There were decreases at temperatures below 7$^{\circ}C$, and less increases at temperatures of 8-10$^{\circ}C$ in biomass. Earthworms could not survive at temperatures at 34$^{\circ}C$ and 35$^{\circ}C$. Feeding rates of earthworms were much higher at 20-32$^{\circ}C$ than them at the other tested temperatures, and there were no differences among them at temperatures of 20-32$^{\circ}C$. But at 3 months after feeding, the biomass and feeding rate of earthworms decreased severely even at 20$^{\circ}C$ and 30$^{\circ}C$, which was supposed to be due to the long term effect of salts, especially sodium chloride (NaCl) in the food wastes.

• Korean Journal of Poultry Science
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• v.18 no.2
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• pp.97-119
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• 1991

Effect of Streptococcus faecium(SF) and an antibiotic, Colistin(Col), supplemented to diets singly or in combination, on the performances and changes of intestinal population of microflora of broiler chicks studied. A total of 252, day-old chicks(Arbor Acre) of mixed sex(M：F＝1：1) were alloted into six groups. A diet with no Col and SF was referred as a control diet. The basal diets were added with two levels of SF, 0.04 and 0.08%, singly or in combination with Col 10ppm Another diet was prepared by adding only Col 10 ppm. Numbers of the microorganism in diets added with SF 0.04% and 0.08% were 7$\times$10$^{4}$ and 1.4$\times$10$^{5}$ /g diet respectively The diets consisting of corn and soybean meal as major ingredients were fed for a period of seven weeks . During the feeding trial, fresh excreta were sampled at the end of every week in a sterilized condition to count microbial changes from each dietary group. Microbial changes of large intestine were also measured from nine birds sacrificed at the end of the 4th and 7th weeks each time per dietary group. Excreta from all the groups were also collected quantitatively at the end of 3rd and 6th weeks to measure digestibility of the diets, At the end of 7th week, nine birds from each group were also sacrificed to measure weight changes of gastrointestinal tracts . Average body weight gains of broilers fed the diets added with SF 0.08% (2.37kg) or SF 0. 08%+col 10ppm(2.34kg) were significantly larger than that of the control(2.18kg). The weight gains of the other groups were not statistically different from that of the control Feed/gain ratios of the supplemental groups were better than that of control (P＜0.05) except that of birds fed the diet added only with SF 0.04%. Digestibilities of nutrients such as dry matter, crude protein, crude fat and total carbohydrates were not altered by the consumption of the diets added with SF and/or Col throughout the whole feeding period. As expected, the numbers of Streptococci in the excreta from birds fed diets added with SF increased significantly with a statistical difference between groups with SF 0.04% and SF 0.08% most of the time. However. addition of Colistin to the diets supplemented with SF did not give any effects on the number of the microorganism. Numbers of coliforms in the excreta were apparently reduced by feeding the diets added with SF and/or Col(P＜0.05). There were, however, no additive effects observed between the two feed additives in this regard when supplementing Col to the SF diets. Distributions of intestinal microflora exhibited exactly the same pattern as those of the excreta. Length of small intestine of the birds fed diets added with SF 0.08% with or without Col 10 ppm became significantly longer with a range of about 10% than those of the birds fed diets without SF. However, the empty weight of the small inestine of the former group was lighter than that of control These changes resulted in a significant reduction in weight/unit length of the intestine of the birds fed diets supplemented with Col and SF singly or in combination. In overall conclusion, diet added with SF 0.08% appeared most effective in improving broiler performances. Colistin added at a level of 10ppm was not beneficial at all in itself or in combination with SF in terms of broiler performances or changes of intestinal microflora population. The efficacy of SF and Col could be attributed to the changes of wall thickness of the small intestine.