• 제목/요약/키워드: temperature descending

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Preliminary Characterization of Keratinolytic Enzyme of Aspergillus flavus K-03 and Its Potential in Biodegradation of Keratin Wastes

  • Kim, Jeong-Dong
    • Mycobiology
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    • 제31권4호
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    • pp.209-213
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    • 2003
  • Aspergillus flavus K-03 isolated from poultry forming soil in Korea was studied for its ability to produce extracellular proteases on basal medium containing 2%(w/v) chicken feathers. The fungus was observed to be a potent producer of such enzymes. Keratinolytic enzyme secretion was the best at 15 days of incubation period at pH 9 and temperature $40^{\circ}C$. No relationship existed between the enzyme yield and increase of biomass. Enzyme production was suppressed by exogenous sugars in descending order arabinose>maltose>mannose>fructose. But glucose did not influence the enzyme activity. The keratinolytic enzyme released by the fungus demonstrated the ability to decompose keratin substrates as chicken feather when exogenous glucose was present. The keratinolytic activity was inhibited by $HgCl_2$ and serine-protease inhibitors such as phenymethylsulfonyl fluoride(100%), chymostain(88%), crystalline soybean trypsin inhibtor(80%), antipain(45%) and aprotinin(40%), and was not by cystein-protease and aspartyl-protease inhibitors. The enzyme activity is only partially inhibited by metallo-protease inhibitor. Thus, the enzyme secreted by A. flavus K-03 belongs to the alkaline serine-type protease.

AN EXPERIMENTAL STUDY ON THE FORMATION OF SMOKE LAYER IN COMPARTMENT FIRE

  • Hur, Man-Sung
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.477-483
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    • 1997
  • Experiments have been performed to investigate the formation of smoke layer in case of several furniture fires such as trashcan, chair, carpet, sofa, mattress, and wardrobe in a residential room. As a result of the present investigation, the uniformly distributed fire of carpet showed that the ignition and the initial growth period were relatively short while the fully developed period was considerably long. The concentrated fires such as mattress and wardrobe showed that the ignition and the initial growth period were relatively long. The descending time of the interface heights was within 1-3 minutes to reach around 1m. However, the interface height was lowered to 0.25-0.75m above the floor at the time of the maximum temperature.

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스틸 커튼월의 단열성능 및 결로방지성능 평가 (Evaluation of the Thermal Performance and Condensation Resistance of a Steel Frame Curtain Wall System)

  • 김선숙;조봉호
    • 한국태양에너지학회 논문집
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    • 제33권3호
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    • pp.51-57
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    • 2013
  • Metal curtain wall systems are widely used in high-rise commercial and residential buildings. While aluminum is the most frequent used frame material, steel framing is also reemerging as a high-performance material in glazed curtain walls due to less thermal conductivity and design flexibility. The purpose of this study is to evaluate thermal performance of a steel frame curtain wall system by comparing with a aluminum frame curtain wall system. The thermal transmittance was measured according to KS 2278, and condensation resistance was calculated by the test results according to KS F 2295. The steel framing test specimen showed lower thermal transmittance and temperature descending factor compared to the aluminum framing test specimen.

대두의 침지중 고형물의 용출속도에 미치는 침지온도의 영향 (Temperature Dependence of Leaching Rate of Soluble Solids during Soaking of Soybeans)

  • 이영헌;이종욱;조상준
    • 한국식품과학회지
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    • 제18권6호
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    • pp.497-502
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    • 1986
  • 새알, 광교, 단엽의 3가지 대두품종을 시료로 하여 그들의 침지과정중 고형물의 용출에 따르는 침지온도의 영향을 비교 검토하였다. 고형물용출량은 침지온도와 침지시간에 높은 의존성을 나타내었으며 $C=k{\cdot}{\sqrt{t}}$의 관계식으로부터 고형물용출속도상수값을 구한 결과 $10{\sim}33mg/min$의 범위에서 대체로 온도가 높아지면 용출속도가 커짐을 알 수 있었다. 이 때의 총괄물질이동계수값은 새알의 경우 실온에서 $67.7mg/m^2{\cdot}h$으로 다른 품종에 비해 그 값이 높았으며 활성화에너값은 4026cal/mole이었다. 일정량의 고형물이 용출될때까지의 Z값을 비교해 보면 용출량이 많아지면서 Z값은 낮아지는 경향을 보이고 있다.

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신품종 느타리버섯의 생육온도에 따른 호흡특성 비교 (Comparison of respiration characteristics on the new variety of oyster mushroom according to the growth temperature)

  • 장명준;하태문;주영철
    • 한국버섯학회지
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    • 제5권2호
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    • pp.65-70
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    • 2007
  • 생육온도가 증가함에 따라 $CO_2(ppm/hr/m^3$/병)농도는 증가하였고, 생육단계별로는 생육후기에 가장 높은 경향을 나타내고 있으며, 품종별로 춘추2호<수한2호<청풍<진미<흑백 순으로 호흡량이 많은 경향을 나타내었다. 또한 생육 온도가 높아짐에 따라 $O_2(ppm/hr/m^3$/병)소비량은 증가하는 경향이었으며, 생육단계별로 생육후기에 가장 많이 소비되는 경향을 보이고 있고, 품종별로 춘추2호<수한2호<청풍<진미<흑백 순으로 소비된 $O_2$량이 많아지는 경향이었다. 그리고 느타리버섯의 생육적정 온도인 $15^{\circ}C$에서의 호흡지수는 춘추2호가 500일 때, 수한2호 528, 청풍 573, 진미 617, 흑백 634로 신품종의 호흡지수는 춘추2호 보다 높은 경향을 나타내었다.

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열전대(thermocouple)를 이용한 Buchanan Plugger 표면의 온도상승 분석 (ANALYSIS OF TEMPERATURE RISE ON THE SURFACE OF BUCHANAN PLUGGER USING THERMOCOUPLE)

  • 조진숙;황윤찬;김선호;황인남;최보영;정영진;정우남;오원만
    • Restorative Dentistry and Endodontics
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    • 제28권4호
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    • pp.334-340
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    • 2003
  • This study was performed to evaluate the actual temperature rise on the surface of Buchanan plugger using thermocouple. The heat carrier system 'System B Heatsource'(Model 1005, Analytic Technologies, Redmond, WA, USA) and the Buchanan pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200^{\circ}C on digital display and the power level on it was set to 10. Five thermocouples were placed in direct contact with the surface of each size of Buchanan's pluggers at 1 mm increments from the tip to the 4 mm length of shank. The heat control spring was touched for 5 seconds. and the temperature rise on the surface of the pluggers were measured at 1 sec intervals for more than 5 seconds with an accuracy of 0.01 using Data Logger. The data were statistically analyzed by one-way ANOVA. The results were as follows. 1. The position at which the temperature peaked was approximately at 1~2 mm far from the tip of Buchanan plugger (p<0.01). 2. The peak temperature was $215.25{\pm}2.28^{\circ}C$ in F plugger. $185.94{\pm}2.19^{\circ}C$ in FM plugger, $169.51{\pm}9.12^{\circ}C$ in M plugger, and 160.79{\pm}1.27^{\circ}C in ML plugger and the peak temperature was highest in F plugger and followed by. in descending order. FM plugger. M plugger. ML plugger showed the lowest peak temperature (p<0.01). 3. The temperature on the plugger was decreased with the increase of touching time. This results suggest that the actual temperature on the surface of the pluggers does not correlate well with the temperature set on digital display. Heat concentrates around the tip. The larger plugger reveals lower temperature rise relatively.

산림휴양지 유형에 따른 피톤치드(모노테르펜) 농도 비교 (Comparison of Phytoncide (monoterpene) Concentration by Type of Recreational Forest)

  • 이용기;우정식;최시림;신은상
    • 한국환경보건학회지
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    • 제41권4호
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    • pp.241-248
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    • 2015
  • Objectives: This study was conducted to provide scientific and effective information on phytoncides, which are associated with forest healing, and to activate recreational forests. Methods: The target sites were natural recreation forests, a forest park and an arboretum, and the control sites were three urban parks. The samples were collected at a volume of 6.0 L and a flow rate of 0.1 L/min for one hour using a low volume pump and the solid adsorbent sampling method. The phytoncide compounds adsorbed in the Tenax TA tube were analyzed by a automatic heat desorption unit and GC-MS. Results: By type of recreational forest, the annual concentrations of phytoncide (monoterpene) for the forest park showed the highest concentration with $1.450{\mu}g/m^3$, while those for the arboretum showed the lowest concentration at $0.892{\mu}g/m^3$, and thus the concentration of the forest park was approximately 1.6 times higher than the arboretum. The season showing the highest concentration of phytoncides was summer (June) and the forest park was the highest among the recreational forests. The concentrations of major components for phytoncide showed in descending order: ${\alpha}-pinene$, ${\beta}-pinene$, camphene, 3-carene and limonene. The seasonal concentration of ${\alpha}-pinene$, camphene and ${\beta}-pinene$ by type of recreational forest increased in April, which is characterized by low temperature and humidity, and the seasonal concentration of camphene decreased with higher humidity. The meteorological factors which had the high correlation with the concentration of total terpene were temperature and humidity. $CO_2$ and $O_2$ showed an inverse correlation. Conclusion: The major components of phytoncide were ${\alpha}-pinene$, ${\beta}-pinene$, camphene, 3-carene and limonene in descending order of concentration. Further and systematic study on the chemical nature of individual phytoncides, and on the effect of phytoncides on humans needs to be performed.

열전에너지 수확 의류를 위한 인체표면 온도분포의 기초적 고찰 (A study on skin temperature distribution of the human body as fundamental data for developing heat energy harvesting clothing)

  • 양진희;조현승;박선형;이주현
    • 감성과학
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    • 제14권3호
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    • pp.435-444
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    • 2011
  • 유비쿼터스 헬스케어 기술 및 휴대용 전자기기의 발전은 지속적으로 전원을 공급하기 위한 새로운 에너지원을 요구하고 있으며, 이러한 점에서 의류를 통한 인체 에너지 수확 시스템의 연구가 요청되고 있다. 인체에너지를 수확하는 방식의 하나인 열전은 인체와 주위 환경간의 온도차이로부터 에너지를 수확하는 방식으로, 본 연구에서 의복을 통한 열전에너지 수확의 기초자료를 확보하기 위하여 인체표면 온도의 분포를 실증적으로 고찰하였다. 이를 위해 체표 구간을 설정하고 구간별 온도분포를 분석하였다. 분석 결과, 상체의 체표온도가 하체에 비해 높았고 특히 심장과 가깝고 혈류량이 많은 몸통 부위의 체표온도가 높았다. 뒷목과 등, 허리의 후면 부위 체표온도가 앞면에 비해 높았으며, 팔 부위의 경우 위쪽 부위의 체표온도가 아래쪽 부위보다 높고 팔 후면이 정면과 측면에 비해 온도가 낮게 나타났다. 체표 구간별 평균 온도와 환경온 간의 차이값이 가장 높아 열전 수확 기능구조 설치에 가장 적합한 위치는 뒷목 부위로 나타났고, 등과 허리 부위, 측면 어깨부위, 가슴 부위, 정면 위팔 부위, 배 부위가 그 뒤를 이었다. 이러한 인체표면 온도분포 결과를 토대로, 본 연구에서는 열에너지 수확의류 개발을 위한 기본 지침을 도출하였다.

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A Study on Evacuation Safety of Trainingship HANBADA using FDS & maritimeEXODUS

  • KIM, Won-Ouk;HAN, Ki-Young;KIM, Dae-Hee
    • 해양환경안전학회지
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    • 제23권3호
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    • pp.266-272
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    • 2017
  • In this study, it was simulated and analyzed the evacuation safety to identify the cadets' evacuation time by using maritimeEXODUS which is applied IMO MSC.1/Circ.1238 theory as well as the trim and heel which are the major factor of reducing the ship evacuation speed. In addition, this study carried out a simulation through the special program for fire analysis - FDS (Fire Dynamics Simulator) in order to find the effective evacuation time, i.e. life survival time. Particularly, this study did comparative analysis of the influence on the survival of cadets based on the collected simulation data by fire size and sort. As a result of the analysis, It was analyzed the Evacuation Allowable Limit Temperature $60^{\circ}C$ and resulted that there is no influence in evacuation by temperature. As a result of the analysis on visibility evacuation limit 5 m, it was found that the only one evacuation rallying point could not meet the evacuation safety. However, it derived the perfect evacuation safety under the condition of two rallying points available on wood fire. In case of Kerosene, it was satisfied the evacuation safety if the heeling was under $10^{\circ}$. Moreover, it could not meet the evacuation safety by evacuating through upper deck although there were two evacuation rallying points. When it was set by the lifeboat descending maximum angle-$20^{\circ}heel$ and $10^{\circ}trim$ which was described in SOLAS regulation, it was simulated that the wood fire having two evacuation rallying points in the center of the ship satisfied the evacuation safety.

건물화재시 개구부의 흐름계수에 관한 연구 (A Study on the Flow Coefficient of Compartment Fire)

  • 허만성
    • 한국화재소방학회논문지
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    • 제10권4호
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    • pp.19-27
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    • 1996
  • 상층부의 온도, 경계면 높이 및 흐름형태를 연구하기 위하여 쓰레기통, 의자, 카페트, 소파, 매트리스 및 장농화재 실험을 실제 건물에서 수행하였다. 상부층의 온도와 경계면의 높이는 사각 쓰레기통의 경우 개구부의 흐름계수가 0.65∼0.8, 원형 쓰레기통 및 의자의 경우는 0.65∼0.9, 카페트, 소파, 매트리스 및 장농의 경우는 0.7∼O.9일 때 실험치와 비교적 잘 일치하였다. 경계면의 높이는 가구화재시 1[m] 근처에서 정상상태를 유지하였다. 다만, 최대온도를 나타내는 시간에는 경계면 높이가 바닥에서 0.25[m]∼0.75[m]까지도 내려왔다. 개구부의 흐름형태는 분산화재의 경우는 filling과 buoyant흐름이 나타났고, 집중화재의 경우는 filling에서 바로 flow로 가고 또 flow기간도 길게 나타났다. 경계면 높이가 내려오는 속도는 가구의 가연성 및 공기와의 접촉면적에 비례하여 경계면 높이가 1[m] 근처까지 내려오는데 소요되는 시간은 1분∼3분 이내로 나타났다.

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