• Title/Summary/Keyword: 온도별

Search Result 3,278, Processing Time 0.037 seconds

Effect of Heating Temperature on Viscosity of Starch Dough (전분반죽의 점도에 미치는 가열온도의 영향)

  • Lee, Boo-Yong;Lee, Chang-Ho;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.27 no.4
    • /
    • pp.593-597
    • /
    • 1995
  • To measure theological properties of the starch dough, an Extrusion Capillary Viscometer(ECV) cell was self-made and attached to Instron machine(Model 1140). Apparent viscosities of corn and waxy corn starch doughs were measured and their gelatinization degrees were determined by enzymatic analysis. The effects of heating temperature on the viscosity of starch dough with $36{\sim}52%$ moisture contents were examined in terms of Arrhenius equation. The activation emergy(Ea) of the dough viscosity from the effect of heating temperatures changed from negative(-) to positive(+), as the moisture content increased from 44% to 48% in the corn starch dough and from 44% to 44% in the waxy corn starch dough.

  • PDF

Effects of Mold Temperatures on Physical Properites of Injection Molded Thermoplastic Polyurethanes (사출성형 열가소성 폴리우레탄의 물리적 성질에 미치는 금형 온도 영향)

  • Lee, Dai-Soo;Kim, Seong-Geun;Nguyen, Vinh-Khanh;Lee, Wing-Ji;Pang, Su-Jin
    • Elastomers and Composites
    • /
    • v.39 no.4
    • /
    • pp.286-293
    • /
    • 2004
  • Ester- and ether-based thermoplastic polyurethanes of different hardness were injection molded at different mold temperatures and effects of mold temperature on the physical properties of TPUs were investigated. Glass transition temperatures of soft segments of TPUs were hardly changed by mold temperatures. The phase separation of soft and hard segments of injection molded TPUs were affected little by mold temperatures. However, crystallinity of hard segments, temperature range of rubbery plateau, and tensile strength of injection molded TPUs decreased with increasing mold temperatures for TPUs of high hardness. However, injection molded TPUs of low hardness showed increases of crystallinity of hard segments, temperature range of rubbery plateau, and tensile strength with increasing mold temperatures. Different physical properties of injection molded TPUs depending on mold temperatures were attributed to different crystallization and physical crosslinking effects of hard segments.

Developmantal Characteristics and Host Preference of Parasitic Natural Enemy, Binodoxys communis (Gahan) (Hymenoptera: Braconidae) (기생성 천적 쌍꼬리진디벌(Binodoxys communis Gahan)의 발육 특성 및 기주선호성)

  • Park, Bueyong;Lee, Sang-Guei;Kim, Gil-Hah
    • Korean journal of applied entomology
    • /
    • v.60 no.3
    • /
    • pp.277-286
    • /
    • 2021
  • The natural enemy was identified as a parasitic wasp, Binodoxys communis Gahan. B. communis taxonomically belongs to the family braconidae, subfamily aphidinae, and genera binodoxys. It develops normally at 17.5 to 32.5℃, and not at 35℃. Depending on the temperature, the longest development period of B. communis was 21.9 days at 17.5℃, and shortest was 6.46 days at 32.5℃. The effective accumulated temperature was 175.44 DD for females as well as males; however, the developmental threshold temperature was 10.87℃ and 10.74℃ for females and males, respectively. This parasitic wasp was found to prefer cotton aphids and soybean aphids as its prey.

Prediction of Temperature and Degree of Cure of Carbon Fiber Composites Considering Thermal Chemical Reaction (화학 반응열을 고려한 탄소 섬유 복합재 온도와 경화도 예측)

  • Jae-Woo Yu;Wie-Dae Kim
    • Composites Research
    • /
    • v.36 no.5
    • /
    • pp.315-320
    • /
    • 2023
  • In the manufacturing process of thermosetting carbon fiber composite materials using an autoclave, the internal temperature changes according to the set temperature cycle. This temperature change causes the resin in the composite material to cure. Heat is generated through the chemical reaction of the resin, which can result in a difference between the temperature inside the autoclave and the temperature of the composite material. Previous research assumed that the temperatures of the composite material and the autoclave were the same and analyzed to predict the residual stress and thermal deformation after manufacturing. However, these stresses and deformations depend on the temperature and degree of cure of the composite material. Therefore, this study verifies a thermal-chemical model analysis technique that takes into account the heat generated by the chemical reaction of the resin to accurately calculate the temperature and degree of cure. Additionally, case studies were conducted for different thicknesses to investigate whether this model exhibits similar trends across varying thicknesses.

Forced Ventilation Number of Air Changes to Set Point of Inside Air Temperature in Summer Glasshouse (여름철 유리온실의 목표온도 유지를 위한 강제환기 회수)

  • 우영회;이정명;남윤일
    • Journal of Bio-Environment Control
    • /
    • v.4 no.2
    • /
    • pp.223-231
    • /
    • 1995
  • Judicious control of high temperature is the most important task for a successful intensive - cultivation in greenhouses during the hot summer. Therefore, the climatological data at 31 locations in Korea were calculated using the modified model equation for ventilated in glasshouses during summer. Furthermore, the adequate number of air- changes or frequency of ventilation was estimated based on temperature settings, which is considered to be more active means of controlling summer glasshouse temperatures, was investigated. The major results can be summarized as follows: Forced ventilation of one air change per minutes was effective in maintaining the maximum air temperature below 35$^{\circ}C$ in the glasshouse haying 40% shading. It was impossible, however, to maintain air temperature below 3$0^{\circ}C$ in 40% shaded glasshouse with forced ventilation only.

  • PDF

A Study of assessment criteria and lifetime prediction for power supply of electrodeless fluorescent lamp (무전극형광램프용 전원장치의 평가기준 및 수명예측)

  • Ham, Jung-Keol;Shin, Jong-Wook
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2004.11a
    • /
    • pp.25-30
    • /
    • 2004
  • This paper gives an assessment criteria and average failure lifetime prediction for power supply of electrodeless fluorescent lamp. The paper present electric appliance safety standard and performance standard for power supply of electrodeless fluorescent lamp. also, It presents the Failure Rate or Mean Time To Failure(MTTF) for power supply of electrodeless fluorescent lamp. We suggest the assessment criteria and improve methods of the reliability on the design basis for the electrodeless fluorescent system.

  • PDF

Luminous Characteristics of Urban Street Between Day and Night (도시가로의 주.야간 빛환경 특성 분석에 관한 연구)

  • Shim, In-Bo;Kim, Bong-Kyun;Kim, Jeong-Tai
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2005.05a
    • /
    • pp.194-201
    • /
    • 2005
  • 도시에서의 빛의 연출은 도시의 축을 부각시키고, 가로의 아이덴티티를 연출함으로서 도시의 인지도를 향상시킬 수 있다. 또한 야간의 경관은 인공조명을 이용한 빛의 연출로 주간과는 다른 빛환경 경관을 연출할 수 있다. 이에 본 연구는 도시 가로 중에서 상업가로와 주거가로를 대상으로 주 야간의 빛환경 특성을 분석하여, 가로의 용도에 따른 주야간의 빛환경 차이를 고찰하였다. 이를 위하여 두 가로의 일정길이에 대하여 수평면조도, 스칼라 조도, 휘도 및 색온도를 측정하였으며 측정결과를 용도별, 주 야별로 비교하여 분석하였다. 측정한 결과를 정리하면 다음과 같다. (1)수평면조도의 측정 결과, 주간의 주거가로에 비하여 상업가로가 28.8[%] 높게 나타났으며 야간의 경우 87.2[%] 높게 나타났다. (2) 스칼라조도의 측정결과, 스칼라조도의 특성상 전반적으로 균일한 분포를 보이며, 수평면 조도와 마찬가지로 주간에 비하여 야간에 84[%] 높은 값이 측정되었다. (3) 휘도의 측정 결과, 주간 배경에 대한 대상의 휘도비는 상업과 주거가로가 1:2이하로 나타나 조화로운 가로경관을 연출하며, 야간배경에 대한 대상의 휘도비는 상업가로는 1:17로 활기 있는 경관을 연출하고 주거가로는 1:5로 가로경관 이미지에 적당한 강조효과가 나타났다. (4) 색온도의 측정 결과, 주간의 배경은 맑은 하늘의 색온도를 나타냈으며 대상은 상쾌하고 활동적인 이미지의 색온도를 나타내었다. 또한 야간의 경우 상업가로와 주거가로 모두 나트륨 등의 영향을 받아 전반적으로 따뜻한 느낌의 색온도가 연출되었다.

  • PDF

A Study of assessment criteria and reliability improvement for power supply of electrodeless fluorescent lamp (고효율 무전극형광등용 전원장치의 평가기준 및 신뢰성향상 연구)

  • 함증걸;신종욱
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.17 no.2
    • /
    • pp.34-40
    • /
    • 2003
  • This paper gives an assessment criteria and reliability improvement for high frequency power supply of high efficacy electrodeless fluorescent lamp. The electrodeless fluorescent lamp system consist of electrodeless fluorescent lamp, high frequency power supply and lighting fixtures. The high frequency power supply has a shortest life at the system. Therefore It is need th assess the Failure Rate or mean Time To Failure(MTTF) for the high frequency power supply of electrodeless fluorescent lamp system and improve the reliability at design. We suggest the assessment criteria and improve methods of the reliability on the design basis for the electodeless fluorescent system.

Properties of Capacitance components depending on Frequency in Organic Light-Emitting Diodes by Temperatures (주파수 변화에 따른 유기발광소자의 온도별 용량성분 특성)

  • Ahn, Joon-Ho;Shin, Eun-Chul;Lee, Eun-Hye;Chung, Yong-Hwan;Jang, Kyung-Uk;Lee, Won-Jae;Seo, Dae-Shik;Kim, Tae-Wan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2006.04a
    • /
    • pp.76-77
    • /
    • 2006
  • 유기발광소자의 주파수 응답 특성은 계면에서의 특성을 파악하는데 유요한 도구이다. 온 연구는 유기발광소자의 재료로 널리 알려진 $Alq_3$를 이용하여 소자를 제작한 후, 주파수 응답 특성을 이용하여 $Alq_3$의 등가회로를 해석하였다. 또 온도에 따른 용량성분을 분석하여 $Alq_3$에 인가된 전압에 따라 용량성분의 변화를 살펴보았다. 용량성분의 변화는 낮은 주파수 영역에서는 나타나지 않다가, 높은 주파수 영역에서 온도에 따라 미묘하게 감소하는 것을 볼 수 있다. 이는 낮은 주파수 영역에서 높은 주파수 영역으로 변화하면서 소자 내의 주된 성분이 저항성분에서 용량성분으로 변화하는 것을 의미하며 높은 주파수에서 온도에 따른 용량성분의 변화를 찾을 수 있었다.

  • PDF

A Study on the Decision of the Interface Height in Compartment Fire (건물화재시 경계면 선정에 관한 연구)

  • 허만성
    • Fire Science and Engineering
    • /
    • v.11 no.2
    • /
    • pp.11-17
    • /
    • 1997
  • The objective of this research is to study on the decision of the interface height in a room in case of trashcan, chair, carpet and sofa as a fire starter in a residential room by performing the experimental studies. For the decision of the interface height, the temperatures of various positions in fire room are measured and the averaged temperatures are calculated from these measured temperatures every time and height. The temperatures of all positions in fire room are obtained as the basis of the measured temperatures and the middle point of the highest temperature slope is decided as the interface point. The interface heights were distinct and were around 1[m] maintaining constant state. However, at the time of the maximum temperature, the interface height was lowered to 0.25[m]-0.75[m] from the floor.

  • PDF