• Title/Summary/Keyword: High temperature and high humidity

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The Effects of Micro-Environmental Factors on the House Dust Mite

  • Jo, Wan-Je;Sohn, Jang Yeul
    • Architectural research
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    • v.9 no.2
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    • pp.37-45
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    • 2007
  • The proliferation of the House Dust Mite(HDM) is affected by temperature, humidity, ventilation, etc. Measuring temperature and humidity was performed at the very location where dust samplings take place and where they live in reality together with temperature and humidity of the ambient of the room. There has been discussion over the key environment factor of HDM survival; absolute humidity or relative humidity. It seems that relative humidity is the more important determinant for the mite's survival through the analysis of previous studies. Temperature, humidity, ventilation rate and Der P1 were measured in 4 flats in London. Mite allergen was detected in every house. Levels of Der P1 varied between <100ng/g and 22,778ng/g. Flats with high relative humidity(>50%) and poor ventilation(<0.5ach) showed higher levels of mite allergen than flats with lower humidity and adequate air change rate. Questionnaire survey was conducted and the result helped to confirm the findings from monitoring of environmental factors and the dust sampling.

Effects of Humidity and Sliding Speed on the Wear Behavior of Silicon Nitride Ceramics (습도 및 미끄럼속도가 질화규소의 마멸거동에 미치는 영향에 관한 연구)

  • 이기현;김경웅
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2597-2605
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    • 1994
  • The wear behavior of two types of $Si_3N_4$ exposed to high and low humidity was examined at various sliding speeds, using bearing steel as disk material under pin-on-disk type sliding conditions. Higher wear rates were obtained at a high humidity than at a low humidity. As the sliding speed was increased, the wear rates were decreased and the effect of humidity on the wear rates of $Si_3N_4$ was reduced. The result that the $Si_3N_4$ pin showed higher wear rate under the high humidity condition was explained by the decrease in microhardness of $Si_3N_4$ due to the chemisorbed moisture on the pin and plowing action by the hard particles of $Fe_2O_3$ from the disk. An increase in the sliding speed is supposed to reduce the effect of humidity on the wear rate of $Si_3N_4$ by raising the average temperature of the disk surface and the local temperature at pin-disk contact point.

Changes of the Physical Properties of Corrugated Fiberboard Boxes for Fruit and Vegetable Packaging by Preservation Temperature and Relative Humidity (과채류 포장용 골판지 상자의 저장온도와 습도에 따른 물리적 특성 변화)

  • Lee, Myung-Hoon;Cho, Jung-Yeon;Shin, Jun-Seop
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.34 no.1
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    • pp.46-53
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    • 2002
  • This study was carried out to analyze the effects of preservation temperature and relative humidity to the physical properties of corrugated fiberboard boxes for fruit and vegetable packaging. The preservation temperature did not affect severely to physical properties of corrugated fiber-board. Relative humidity was a major cause of corrugated fiberboard box quality deterioration. The burst and compressive strengths of experimental boxes measured with Mullen high pressure tester and tong crush tester were decreased gradually as relative humidity increased from 55% to 75%. But, the strength properties slightly decreased relative humidity at 75% or higher. This tendency was the greater for single wall (SW) corrugated fiberboard box than that for double wall (DW). It is suggested that development of the water-resistant corrugated fiberboard and box be needed that can be used under the condition of low temperature and high moisture content, which are being employed in the cold chain system.

A study of the Possibility of the Charcoal as Desiccant (흡착제로서 숯의 이용 가능성에 대한 연구)

  • Kim, Jong-Ryeol
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.5
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    • pp.1083-1089
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    • 2014
  • The aims of this study are to find out the possibility of the charcoal as a desiccant. The only humidity control under high temperature and high humidity environment can be provided to the thermal comfort at indoor environment. Functionality of charcoal is known to be deodorization, antiseptic effect, filtering effect and humidity control. But research related to humidity control in the country not yet. Thus, the dehumidification capacity of the charcoal experimental results to see the results were as follows : 1) Entering the experimental humidification is 148.02 g/h, 161.05 g/h and 243.2 g/h when air velocity was changed 1.5 m/s, 1.7 m/s and 2.0 m/s. 2) When the basis weight of the charcoal 2.0 m/s air velocity to obtain the largest number of adsorption capacity. 3) Dru bulb temperature and dew point temperature ware measured at front and rear of the charcoal. Absolute humidity is calculated from the measured Dry bulb temperature and dew point temperature. The quantity of dehumidification is calculated from absolute humidity is the largest 129.6 g/h at the air velocity 2.0 m/s.

Effect of Reserve Air-Drying of Korean Pine Heavy Timbers on High-temperature and Low-humidity Drying Characteristics (예비천연건조가 잣나무 중목구조부재의 고온저습건조 특성에 미치는 영향)

  • Lee, Chang-Jin;Lee, Nam-Ho;Park, Moon-Jae;Park, Joo-Saeng;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.49-57
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    • 2014
  • The pre-air-drying of Korean pine before the high-temperature and low-humidity drying was shown to be effective in uniform moisture content distribution and prevention of surface check. Our results suggest that initial moisture content of the timber also plays important role in high-temperature and low-humidity drying method. The pre-air-drying also helps in the reduction of surface checks in Korean pine when compared to the Korean pine dried by only high-temperature and low-humidity. End-coating was not effective in the prevention of twist, shrinkage, case hardening and internal checks. The pre-air-drying reduces the internal tension stresses which occur during high-temperature and low-humidity drying thus decreasing case hardening and also preventing internal checks. The pre-air-drying decreases the moisture content and causes shrinkage which leads to increased twist in the Korean pine.

Excellent toluene removal via adsorption by honeycomb adsorbents under high temperature and humidity conditions

  • Cho, Min-Whee;Kim, Jongjin;Jeong, Jeong Min;Yim, Bongbeen;Lee, Hyun-Jae;Yoo, Yoonjong
    • Environmental Engineering Research
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    • v.25 no.2
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    • pp.171-177
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    • 2020
  • Removal through adsorption is the most widely used and effective treatment method for volatile organic compounds (VOCs) in exhaust gases. However, at high temperatures and humidity, adsorption is competitive due to the presence of moisture and unsmooth physical adsorption thereby deteriorating adsorption performance. Therefore, water adsorption honeycomb (WAH) and VOCs adsorption honeycomb (VAH) were prepared to improve VOCs adsorption at high temperatures and humidity. Adsorbed toluene amounts on single honeycomb (SH), containing only VAH, and combined honeycomb (CH), containing WAH and VAH, were determined. Further, the toluene adsorption rates of honeycomb adsorbents mounted on rotary systems, VAH-single rotor (SR) and WAH/VAH-dual rotor (DR) were determined. Toluene adsorption by WAH/VAH-CH (inlet temperature: 40-50℃; absolute humidity: 28-83 gH2O/kg-dry air) was 1.6 times that by VAH-SH, and the water adsorption efficiency of WAH/VAH-CH was 1.7 times that of VAH-SH. The adsorption/removal efficiency of the WAH/VAH-DR (inlet temperature: 45℃; absolute humidity: 37.5 gH2O/kg-dry air) was 3% higher than that of VAH-SR. This indicates that the WAH at the rotor inlet selectively removed water, thereby improving the adsorption efficiency of the VAH at the outlet.

The Influences of Temperature and Humidity in Storage Room, Moisture Content and Packing Weight of Leaf on the Carbonization of Processed Flue-cured Leaf Tobacco (저장실의 온습도, 제통수분함량 및 제통중량이 황색종 가공엽의 탄화에 미치는 영향)

  • 김상범;안동명;이윤환;김용규;복진영
    • Journal of the Korean Society of Tobacco Science
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    • v.23 no.1
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    • pp.19-30
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    • 2001
  • This study was carried out to investigate the influences of environmental condition in storage room, moisture content and packing weight of leaf on the carbonization of processed flue-cured leaf tobacco, and find out a regression model able to pre-estimate the degree of carbonization. The influence of temperature and humidity in storage room on the carbonization was high,, while that of packing weight was relatively low, However, high moisture content and packing weight of leaf accelerated the carbonization under the high temperature and humidity condition. Thus the leaf tobacco under the condition of 4$0^{\circ}C$, 7$0^{\circ}C$ R.H. in storage room, 16% moisture content and 286 kg/box of packing weight could be carbonized within one month. The pH, total sugar content, lightness(L) and yellowness(b) of leaf were closely related to carbonization of leaf during storage. There were significant regression and yellowness of leaf. It is considered that the certification and/or pre-estimation of carbonization during storage may be possible by applying the regression equation.

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SPAES/Silicate Hybrid Membranes for High-Temperature and Low-Humidity Proton Exchange Membrane Fuel Cells (고온-저습용 연료전지를 위한 SPAES/Silicate 복합막)

  • So, Soon Yong;Kim, Tae Ho;Kim, Sung Chul;Hong, Young Taik
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.147-147
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    • 2010
  • An electrolyte membranes for high temperature/low humidity is a demand for the proton exchange membrane fuel cells (PEMFCs). In this work, we prepared hybrid membranes, which have novel glass content in the hydrophilic and hydrophobic part of sulfonated poly(arylene ether sulfone) (SPAES) by in-situ sol-gel synthesis of various functional silane. The effect of silicate from functional silane content on the proton conductivity, water uptake of the hybrid membranes under high temperature and low humidity was quantitatively identified. The silicate content contributed to the enhancement of not only proton conductivity, but also water retention ability for PEMFCs operation.

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High Temperature and High Humidity Test for MEMS Devices (MEMS 디바이스의 고온고습 신뢰성시험)

  • Lee, Y.G.;Park, B.H.;Jang, J.S.
    • Journal of Applied Reliability
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    • v.5 no.4
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    • pp.487-500
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    • 2005
  • MEMS devices usually have micro actuators contained in a cavity, If the pressure level of testing chamber is higher than that of cavity, moisture will ingress into the cavity, which may cause critical failure such as stiction of the moving parts. To design an accelerated life test based on high temperature and high humidity, such a phenomena should be considered. In this study, a throughput model that can estimate the amount of moisture ingress is used to decide the testing time and conditions of a high temperature and high humidify test.

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Humidity and Temperature Response Characteristics of Optical Fiber Dislocation Fusion Sensor Coated with Graphene Quantum Dots

  • Dailin Li;Xiaodan Yu;Ning Wang;Wenting Liu;Shiqi Liu;Liang Xu;Dong Fang;Huapeng Yu
    • Current Optics and Photonics
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    • v.7 no.5
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    • pp.504-510
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    • 2023
  • An optical fiber dislocation fusion humidity sensor coated with graphene quantum dots is investigated. A Mach-Zehnder interferometer is fabricated with three dislocated single-mode fibers with graphene quantum dots coating humidity-sensitive materials. Humidity response experiments showed a good linear response and high sensitivity with easy fabrication and low-cost materials. From 22% to 98% RH, the humidity response sensitivity of the sensor is 0.24 dB/% RH, with 0.9825 linearity. To investigate the cross-response of humidity and temperature, temperature response experiments are conducted. From 30 ℃ to 70 ℃, the results showed 0.02 dB/℃ sensitivity and 0.9824 linearity. The humidity response experimental curve is compared with the temperature experimental curve. The big difference between humidity sensitivity and temperature sensitivity is very helpful to solve the cross-response of humidity and temperature. The influence of temperature fluctuations in humidity measurements is not obvious.