• Title/Summary/Keyword: heat-freeze

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Hydrological Study of the Freezing in Summer Season at the Ice Valley, Korea (얼음골의 하계 결빙현상에 관한 수문학적 연구)

  • 배상근
    • Water for future
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    • v.23 no.4
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    • pp.459-466
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    • 1990
  • In the Ice Valley, it freeze in summer season. However, there is no ice during winter. In order to clarify the phenomenon of unusual temperature, numerical experiments were conducted using the coupled equations of fluid flow and heat transfer. The results demonstrated that temperature inversion in the Ice Valley is primarily due to delay of the groundwater temperature. Also, the results of the simulation suggest that major factors affecting the delay are the topographical configuration, geological factors and groundwater flow system, combined with groundwater recharge and discharge systems.

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Development of Separating Techniques on Quercetin-Related Substances in Onion(Allium cepa L.) 2. Optimal Extracting Condition of quercertin-Related Substances in Onion (양파의 Quercetin 관련 물질의 분리 기술 개발 2. 양파의 Quercetin 물질의 최적 추출조건)

  • 강성구;김용두;현규환;김영환;서재신;박양균
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.687-692
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    • 1998
  • To use onion(Allium cepa L.) residue as raw materials of food product, yields of onion-juice according to various extracting methods and optimal extracting condition of quercetin and its related glycosides were carried out. Onion juices gained by the methods of pressing, rotary crushing, freeze pressing and enzyme treatment. The yield by the method of enzyme treatment was higher than others. The yields of juice from fresh onion and heat-treated onion(8$0^{\circ}C$/10min) by pressing were 66% and 83%, respectively. Ethanol extraction of onion was efficient at 75$^{\circ}C$ and acetic acid extraction was proper at 3% concentration for 3 hours at 11$0^{\circ}C$. The onion extract was fractionated in the order of hexane, chloroform, ethylacetate and butanol to test flavonoids. The highest abundant flavonoids were found in ethylacetate and butanol fraction.

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Microporous Polystyrene Membranes Produced via Thermally Induced Phase Separation (열적으로 유도된 상 분리에 의해 제조된 폴리스티렌 미세 다공성 막)

  • Song, Seung-Won;Torkelson, John M.
    • Membrane Journal
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    • v.5 no.3
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    • pp.119-128
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    • 1995
  • The effects of coarsening on microstructure formation in polystyrene-cyclohexane solutions and membranes made from them were studied by scanning electron miccoscopy(SEM). Thermal analysis of the polymer solutions was carried out with a differential scanning calorimeter and the binodal curve was determined from the onset temperature of the heat of demixing peak. Using thermally induced phase separation(TIPS) and a freeze drying technique, it was demonstrated that polymer membrane microstructure can be changed significantly by controlling coarsening time and quench route. For systems undergoing phase separation by spinodal decomposition, resulting in a well interconnecmd, microporous structure with nearly uniform pore sizes, it was found that extending the phase separation time prior m freezing and solvent removal can result in a significant increase in pore or cell size which is highly dependent on both quench depth and coarsening time. Also this study has revealed the important role of polymer concentration in dictating the material continuity of the membranes.

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Conservation of Bamboo Slips excavated from Mado Shipwreck No.1 (마도1호선에서 출수된 죽찰의 보존처리)

  • Yoon, Yong Hee;Kim, Eung Ho;Cha, Mi Young
    • 보존과학연구
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    • s.37
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    • pp.17-26
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    • 2016
  • Mado shipwreck No.1 is where a total of 57 bamboo slips were discovered. Bamboo slips first excavated in the sea. It treated low concentration PEG vacuum freeze drying treatment refer to the method that research finding consolidation about waterlogged bamboo before. PEG 2000 and PEG 4000 used to consolidation materials but some bamboo slips that treated PEG 4000 surface color have been darken using heat gun at surface treatment. So the residual PEG on object's surface was remove steam iron. Bonding used to put 100% PEG 2000 the rayon paper in the surface for stabilization and giving a strength.

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Utilization and Isolation of new active substances from Sericulture Related MaterialsII. Development of an oral antihyperglycemic agent from silkworm powder

  • Ryu, Kang-Sun;Lee, Heui-Sam;Choue, Ryo-Won;Chung, Sung-Hyun
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 1997.06a
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    • pp.133-158
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    • 1997
  • Since 1992, Sericulture & Entomology Research Institute(NSERI) and Kyung Hee University group screened an activity of lowering blood-glucose levels with silkworm related materials such as silkworm larvae powder, dried feces, pupae and silkworm moth in other to guide laymans to rational and educated utilization of silkworm-related materials for the treatment of diabetes mellitus. In experiments examining several silkworms in different stages and prepared in different conditions, a freeze dried silkworm powder of 5th instar 3rd day showed a higher glucose lowering activity about 20% than heat dried matured silkworm powder. Among the three dosage of 500mg, 830mg and 1,160mg in ate preliminary clinical trial, the 830mg exhibited a significant effect on postprandial blood glucose level and did and did not cause any hypoglycemic side effect. In the blood glucose lowering activity of mulberry and silkworm varieties, the Yongcheonppong and Samkwangjam showed the highest activity for lowering blood glucose levels. In experiments to see the difference in blood-glucose lowering activity between either male and female or larvae and pupae, activity of larvae was higher than that of pupae and the male was higher than female. The heating dry and artificial diet showed lower than mulberry diet and normal freeze dry of the 5th instar 3rd day. Among the sericultural products, larvae showed the highest activity. We find out the fact that effect of silkworm powder attributed to the inhibition of ${\alpha}$-glucohydrolase catalyzed reaction in the small intestine.

Effect of γ-Aminobutyric Acid-producing Lactobacillus Strain on Laying Performance, Egg Quality and Serum Enzyme Activity in Hy-Line Brown Hens under Heat Stress

  • Zhu, Y.Z.;Cheng, J.L.;Ren, M.;Yin, L.;Piao, X.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.1006-1013
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    • 2015
  • Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high ${\gamma}$-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens. Hy-Line brown hens (n = 1,164) at 280 days of age were randomly divided into 4 groups based on the amount of freeze-dried GABA-producer added to the basal diet as follows: i) 0 mg/kg, ii) 25 mg/kg, iii) 50 mg/kg, and iv) 100 mg/kg. All hens were subjected to heat-stress treatment through maintaining the temperature and the relative humidity at $28.83{\pm}3.85^{\circ}C$ and 37% to 53.9%, respectively. During the experiment, laying rate, egg weight and feed intake of hens were recorded daily. At the 30th and 60th day after the start of the experiment, biochemical parameters, enzyme activity and immune activity in serum were measured. Egg production, average egg weight, average daily feed intake, feed conversion ratio and percentage of speckled egg, soft shell egg and misshaped egg were significantly improved (p<0.05) by the increasing supplementation of the dietary GABA-producer. Shape index, eggshell thickness, strength and weight were increased linearly with increasing GABA-producer supplementation. The level of calcium, phosphorus, glucose, total protein and albumin in serum of the hens fed GABA-producing strain supplemented diet was significantly higher (p<0.05) than that of the hens fed the basal diet, whereas cholesterol level was decreased. Compared with the basal diet, GABA-producer strain supplementation increased serum level of glutathione peroxidase (p = 0.009) and superoxide dismutase. In conclusion, GABA-producer played an important role in alleviating heat-stress, the isolated GABA-producer strain might be a potential natural and safe probiotic to use to improve laying performance and egg quality in heat-stressed hens.

Analysis of In-situ Temperature Measurement at Gonjiam Cold Storage Cavern (곤지암 지하암반 저장고 온도계측 결과 분석)

  • Lee Gyu-Sang;Lee Chung-In
    • Tunnel and Underground Space
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    • v.15 no.3 s.56
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    • pp.169-176
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    • 2005
  • The decreasing pattern of underground temperature measured at 'Gonjiam cold storage cavern' during 7 years which was the first commercial scale underground food storage cavern in Korea was analyzed. The variation of energy consumption was discussed by comparing the consumed energy at the initial operation stage with that at later stage, when the temperature distribution reached a stabilized condition. The point to be considered at the design stage was also discussed by comparing the required refrigerator capacity at the initial operation stage with that at later stage. The extra energy to freeze the groundwater contained in pore space was discussed by analyzing the changing pattern of the rock temperature. The variation of measured rock temperature was compared with the estimated temperature using a numerical code, FLAC. The accuracy of the numerical estimation was discussed by comparing the heat flux measured by the operation time of the refrigerator with that estimated numerically.

Preparation and Characterization of High Absorptive Cellulose Film Derived from Styela Clava Tunic for Wound Dressing (흡수성이 우수한 창상치료용 미더덕껍질 셀룰로오스필름의 제조 및 특성 분석)

  • Seong, Keum-Yong;Koh, Eun-Kyoung;Lee, Seunghyun;Kwak, Moon Hwa;Son, Hong Joo;Lee, Hee Seob;Hwang, Dae Youn;Jung, Young Jin
    • Textile Coloration and Finishing
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    • v.27 no.1
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    • pp.70-79
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    • 2015
  • To establish the optimal conditions for the manufacture of high absortive cellulose film(CF) originated from Styela clava tunic(SCT), the physicochemical properties included absorption was measured in CFs prepared under the various conditions. The highest absorption was observed for SCT-CF20 prepared from the cellulose solution dissolved at $80^{\circ}C$ for 20min, although the filtration treatment did not induce any significance alteration. Also, the absorption was higher in SCT-CF20-F prepared by the freeze drying than SCT-CF20-N(ambient air drying) and SCT-CF20-H(heat drying). The addition of porogen($NaHCO_3$) induced an increase of absorption in SCT-CF20-PF relative to SCT-CF20-F, while the number of interconnected porous structures was enhanced in SCT-CF20-PF. Furthermore, a high level of SK-MEL-2 cells viability was observed in SCT-CF20-PN and SCT-CF20-PF cultured group. These results show that SCT-CF may have high absorption and biocompatibility when prepared from SCT cellulose solution dissolved at $80^{\circ}C$ for 20min after addition of porogen and then subjected to freeze drying.

Effect of Heat Treatment on the In Vitro Protein Digestibility and Trypsin Indigestible Substrate (TIS) Contents in Some Seafoods (수산단백질(水産蛋白質) 소화화(消化華)에 미치는 가열처리(加熱處理)의 영향(影響))

  • Ryu, Hong-Soo;Lee, Kang-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.1
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    • pp.1-12
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    • 1985
  • In an attempt todetermine the optimum heat treatment, the changes in TIS content and in vitro protein digestibility of squid, shrimp, oysterand pollock under various heating conditions were studied. The effect of drying method and cold storage on the in vitro digestibility and TIS content were also studied. Optimal boiling conditions were 1 min, for squid, 0.5min. for oyster(eviscerated), 1 min. for whole oyster, and 5 min. for pollock. Steaming times that yieled products with the highest in vitro digestibility value were: 1 min. at $100^{\circ}C$ for squid, 1 min, at $88^{\circ}C$ for oyster and $1{\sim}2.5min$. at $100^{\circ}C$ for pollock. All of freeze dried samples showed the highest in vitro digestibility value and sundried one were comparble to freeze dried samples except high fat level or noneviscerated samples. Fat content was the nain inhivbitory factor of the seafood enzymic digestion during processing and storage. The multi-enzyme assay, used to predict the quality change of dried seafoods stored in a cold room for long periods of raw seafoods treated with various heating methods, offers many advantages over the convetional methods of determining protein quality.

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Antioxidant and Anticancer Activities of Extracts from Styela clava According to the Processing Methods and Solvents (가공방법 및 용매에 따른 미더덕 추출물의 항산화 및 항암효과)

  • Kim, Jin-Ju;Kim, Sun-Jung;Kim, Sun-Hee;Park, Hae-Ryong;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.3
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    • pp.278-283
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    • 2006
  • Styela clava was processed by four different kinds of method including FR (fresh S. clava), H1 (heat treated S. clava at $110^{\circ}C$ for 15 min) H2 (heat treated S. clava at $120^{\circ}C$ for 5 min), and FD (freeze dried S. clava). Each S. clava sample was treated with methanol, ethanol, acetone, and water, then antioxidant and anticancer activities of the extracts were evaluated. In extracts from non-dried S. clava (FR, H1, and H2), total extract yield decreased with increasing treated temperature. The extraction yield was in the order of ethanol>methanol>water>acetone among treated solvents. In case of dried S. clava (FR), the extraction yield was lower than non-dried samples, and was in the order of methanol>ethanol>water>acetone. The radical scavenging activity (RSA) of non-dried S. clava (FR, H1, and H2) was in the order of acetone>ethanol>methanol and heat treatment also decreased RSA. RSA of FD was the highest in ethanol extract, while acetone and water extracts did not show RSA. When antioxidant activity was determined by reducing power (RD), methanol extract of FR showed the highest values and heat treatment decreased RD, too. RD of FD was in the order of methanol>ethanol>water>acetone. The acetone extracts from FD showed significant anticancer activity against human colon cancer cell line HT-29. These results indicated that extraction yield and properties of extracts from S. clava were dependent on processing temperature, solvent and/or physicochemical state. The appropriate extraction process should provide some valuable bioactive materials from S. clava.