• Title/Summary/Keyword: air temperature factors

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Development of the Numerical Model for Temperature Prediction of Fruits (청과물의 품온예측모델 개발)

  • 김의웅;김병삼;남궁배;정진웅;김동철;금동혁
    • Journal of Biosystems Engineering
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    • v.20 no.4
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    • pp.343-350
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    • 1995
  • In order to design efficient and effective pressure cooling system for fruits and vegetables, a numerical model for temperature prediction of fruits was developed. This model was extended to study the various factors affecting product cooling time, such as product depth, approach air temperature, entering air velocity and initial product temperature. Also, selection of these factors were examined with respect to the efficiency of the pressure cooling system, the overall precooling cost and the final quality of the product. When designing a pressure cooling system for a particular product, the range of the factors must be selected carefully according to the thermal and physiological properties.

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Analysis of Climatic Factors during Growing Period of High-Quality Oak Mushroom(Lentinus edodes(Berk) Sing) (고품질 표고 생산 지역의 버섯 생산기간중 기후 분석)

  • 손정익;최원석
    • Journal of Bio-Environment Control
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    • v.9 no.2
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    • pp.115-119
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    • 2000
  • Oak mushroom(Lentinus edoes(Berk) Sing) is one of the most important edible mushrooms, and its production has been rapidly increased due to nutritional and medicinal effects. In this study, climatic factors during the growing period of high-quality oak mushroom were analyzed and environmental factors affecting the quality of oak mushroom were discussed. Three places(Changheung, Puyo and Wonj) as mass producing areas of high-quality oak mushrooms and the 15 days of the growing period in 1997-1998 were selected. Major climatic factors for analysis were average air temperature, average relative humidity, ranges of daily air temperature, relative humidity, and wind speed. During the period, th daily average air temperature was $7~20^{\circ}C$ with the diurnal air temperature($7~20^{\circ}C$) and nocturnal air temperature($0~-2^{\circ}C$). The relative humidity ranged between 50 and 70% with the range of daily relative humidity(40~60%). Wind velocity was 1~4m.$s^{-1}$, From the results, it is concluded that the growing environmental conditions for high-quality oak mushroom differed from the optimum conditions for the high productivity of oak mushroom; environmental conditions such as wide ranges of air temperature and relative humidity, low humidity and wind speed might affect the emergence of high-quality oak mushroom.

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Sleep and Temperature (수면과 온도)

  • Kim, Hye-Geum;Seo, Wan Seok
    • Sleep Medicine and Psychophysiology
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    • v.23 no.2
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    • pp.47-52
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    • 2016
  • Changes in core body temperature are closely related to initiation and maintenance of sleep, and are influenced by various factors such as air temperature, room temperature, clothing, human activities, and medications. These factors are closely related to sleep fragments, insomnia and other sleep disorders. Understanding the effect of the temperature related to human surroundings on the core body temperature and sleep, will be useful for understanding the physiology of sleep and to treat sleep disorders.

Investigation of influence of linear diffuser in the ventilation of operating rooms

  • Keshtkar, Mohammad Mehdi;Nafteh, Maryam
    • Advances in Energy Research
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    • v.4 no.3
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    • pp.239-253
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    • 2016
  • Air quality in hospitals has always concerned hospitals' health officials due to its dangerous particles and gases. Because of the importance of air conditioning in the operating room, a system must be embedded in operating rooms to direct the contaminated air outside, and inject fresh filtered air from outside back into the room. In this study, laminar flow air conditioning system is implemented in the operating room by slot linear diffusers and with the help of air curtain. For this, stimulation Computational Fluid Dynamic (CFD) was used due to its efficiency. The aim of the present study was to find a proper solution to overcome the unfavorable factors, namely, contamination, humidity, and also temperature, velocity and pressure inside the room. These factors were implemented with different values and then stimulated through FLUENT software program. Results showed that the aforementioned factors can be overcome using air curtain and slot linear diffusers.

An experimental study on emission control of HC and CO due to oxidizing catalyst (산화촉매에 의한 자동차 배출가스중 HC 및 CO의 정화에 관한 실험적 연구)

  • 한영출;최규훈
    • Journal of the korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.46-53
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    • 1981
  • This paper describes emission control of hydrocarbon and carbon-monoxide due to oxidizing catalyst. The experiment was performed on a precious metal pelleted catalyst(Pt). The factors of the efficiency for purification due to oxidizing catalyst are space velocity, temperature, composition of exhaust gas and supplementary air. The experiment was carried out to control the factors of efficiency for purification. The results of experimental study show that temperature of catalytic converter, supplementary air and space velocity affected the efficiency for purification of hydrocarbon and carbon monoxide.

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Influencing Factors that Affect the Biological Monitoring of Workers Exposed to N,N-Dimethylformamide in Textile Coating Factories (섬유코팅업종사 근로자에서 디메틸포름아미드의 폭로에 의한 생물학적 모니터링에 영향을 미치는 인자)

  • Chung, In-Sung;Kim, Jong-Ghan;Choi, Sang-Kug;Bae, Jong-Youn;Lee, Mi-Young
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.2
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    • pp.171-176
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    • 2006
  • Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

Temporal Variation of Air Temperature in Ice-Valley at Milyang in Association with Ice Formation

  • Lee, Soon-Hwan;Hwang, Soo-Jin
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.598-602
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    • 2007
  • A long-term in situ observation was carried out in the Ice-valley at Milyang in order to explain the factors and processes associated with the summertime ice formation. The variation of temperature inside Ice-valley in relation with ice formation in summer time was found to depend on precipitation rate in spring and cold air sinking in autumn and winter. The rate of temperature rising tends to correspond to sensible heat release depending on the precipitation amount at the freezing location. The reason of the cold air accumulation in a talus in the Ice-valley is the cold air sinking over the surface of talus due to the occurrence of outside clod air mass and the accumulated cold air from autumn to spring flow outside at the bottom of talus. The out-flowing cold air can result in the ice formation in the hot summer.

Effect of Temperature and Immersion Time on the Environmental Adhesive Strength of Adhesively Bonded Joints of Rolled Steel Sheet (압연강판 접착제 접합부의 환경 접합강도에 미치는 온도 및 침수시간의 영향)

  • Song, Jun-Hee;Lee, Hee-Jae;Lim, Jae-Kyoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.12
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    • pp.2662-2669
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    • 2002
  • Recently structural applications of adhesive bonding method have been increased extensively in automobile industry. Adhesively-bonded joints which are used in automobile field are exposed to various environmental conditions. In this study, several environmental factors were concerned to evaluate their effects on the adhesive strength such as air temperature, water temperature, exposed time in water. The specimens are exposed for 1, 10 and 100 hours at various air temperatures to evaluate the effects of the air and water temperature on the adhesive strength. It is proved that the adhesive strength decrease with rising the air and water temperature, and the adhesive strength decrease steeply at the higher temperature with increasing the exposure time in water.

Moisture Content Change of Korean Red Pine Logs During Air Drying: I. Effective Air Drying Days in Major Regions in Korea (소나무 원목의 천연건조 중 함수율 변화: I. 국내 주요지역의 유효천연건조일수 조사)

  • HAN, Yeonjung;EOM, Chang-Deuk;LEE, Sang-Min;PARK, Yonggun
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.6
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    • pp.721-731
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    • 2019
  • Air drying depends on species, density, dimension of wood, the geographical location of the air drying yard, and the meteorological factors of air drying site. If there are four seasons with large difference in temperature and humidity like in Korea, the research of the meteorological factors is required in air drying site. In this study, effective air drying days (EADD) of 24 regions in Korea were calculated by using the average monthly temperature, relative humidity, and wind speed. The EADD in 24 regions in Korea was ranged from 239 days to 291 days, with an average 265 days. This result is 5 days increased compared to the average of EADD calculated using the meteorological factors from 1955 to 1984. The results of multiple regression analysis on the EADD and meteorological factors showed that EADD affected in the order of temperature, relative humidity, and wind speed. As a result of dividing Korea into 4 zones of EADD, the zones of EADD were moved northward compared to previous study due to global warming. As basic data for predicting the moisture content (MC) distribution of Korean red pine logs during air drying conducted in Seoul, the average monthly temperature, relative humidity and wind speed for three years from 2016 to 2018 were presented, and the corresponding changes of the equilibrium MC were analyzed.

Effect of Temperature Conditions on Electrochemical Properties for Zinc-Air Batteries (온도조건에 따른 아연-공기 전지의 전기화학적 특성)

  • Lee, Ju Kwang;Jo, Yong Nam
    • Korean Journal of Materials Research
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    • v.30 no.12
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    • pp.687-692
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    • 2020
  • A zinc-air battery consists of a zinc anode, an air cathode, an electrolyte, and a separator. The active material of the positive electrode is oxygen contained in the ambient air. Therefore, zinc-air batteries have an open cell configuration. The external condition is one of the main factors for zinc-air batteries. One of the most important external conditions is temperature. To confirm the effect of temperature on the electrochemical properties of zinc-air batteries, we perform various analyses under different temperatures. Under 60 ℃ condition, the zinc-air cell shows an 84.98 % self-discharge rate. In addition, high corrosion rate and electrolyte evaporation rate are achieved at 60 ℃. Among the cells stored at various temperature conditions, the cell stored at 50 ℃ delivers the highest discharge capacity; it also shows the highest self-discharge rate (65.33 %). On the other hand, the cell stored at 30 ℃ shows only 2.28 % self-discharge rate.