• Title/Summary/Keyword: humidity condition

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A Study on the Heat and Moisture Transport Properties of Vapor-Permeable Waterproof Finished Fabrics for Sports Wear (스포츠웨어용 투습방수직물의 열·수분이동 특성에 관한 연구)

  • Son, Bu Hun;Kim, Jin-A;Kwon, Oh Kyung
    • Fashion & Textile Research Journal
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    • v.2 no.3
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    • pp.220-226
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    • 2000
  • This study was to determine the characteristics of vapor-permeable waterproof finished fabric by the coating method. 4 different kinds of coating fabrics (A : wet, porous, polyurethane, B : dry, no porous, polyurethane, C : shape memory polyurethane and D : dry, porous polyurethane) were used, which were developed recently With this sample, moisture transport rate ($40^{\circ}C$, 45%RH & $40^{\circ}C$, 95%RH), changes of coating side's shape by washing times, water repellency rate, contracted length, qmax, heat conductivity, heat keeping rate, heat keeping rate with cotton, heat keeping rate on humidity temperature and humidity within clothing etc. were checked. And it was done in a climate chamber under $20{\pm}2^{\circ}C$, $65{\pm}5%RH$. The results of this study were as follow; In the moisture vapor transmission of sample B and C increased on high temperature and high humidity while sample A and D decreased, on this condition. Qmax rate had high relation with ground fabric's surface properties and the order was A>C>D>B. Heat conductivity had high relation with thickness and surface properties. Heat keeping rates on sweat condition showed around half percents of heat keeping rates on normal condition, but had no relation with moisture vapor transport rate. Changes of the fabric's properties by washing times were different in accordance with the construction of fabrics and the coating resin. Sample C had tow heat keeping rate on the high temperature and humidity and high heat keeping rate on the low temperature and humidity Moisture transport rate of vapor-permeable waterproof finished fabrics had high relation with the properties of ground fabrics on low humidity condition, but on the high humidity condition, it was highly related with the properties of coating resin.

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Forest Stratification Effect of Air Temperature and Humidity in the Green Space (수림의 계층구조가 녹지내의 기온 및 습도에 미치는 영향)

  • Yoon, Yong-Han
    • Korean Journal of Environmental Biology
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    • v.21 no.2
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    • pp.120-125
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    • 2003
  • For this study grasp coverage condition and forest stratification to various green space, observed air temperature and relative humidity. With this data, coverage condition and air temperature, relative humidity distribution, analyzed relationship of forest rate and air temperature or relative humidity, tree numbers and green volume and humidity by revolution analysis. In this result, higher none is formed artificiality and barren area, lower zone did fores and water area. Relative humidity have corresponding type of air temperature distribution. lower Tone was higher humidity. Different of Idlest type or water area, surround of forest showed relatively higher humidity. Increasing tree numbers or green volume effect higher humidity and this efficiency order of an arbor, subarbor, shrub.

The preliminary study of developing strong corrugated box board against aggravated service condition(I) (환경변화에 강한 골판지 개발을 위한 기초연구(제1보))

  • 서영범;오영순
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.1
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    • pp.29-43
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    • 1998
  • This study was to investigate the effect of .compressive load and cyclic humidity(2$0^{\circ}C$, 65% and 90% RH) on the physical and mechanical properties of corrugated board. Corrugated boards in the study were under compressive load and under cyclic humidity, and their properties were compared to those without load. Results were summarized as follows ; 1 Statistically significant correlation was shown between the ring crush of the boards and the compressive strength of cylinder specimen made from the boards. So we could study the compressive behavior of board with cylinder specimen. 2. The boards under the compressive load increased their moisture content and thickness much more than those without load both in constant and in cyclic RH. 3. The compressive and tensile strength of board samples were inversely and closely proportional to the sheet moisture content regardless of their load and humidity history. 4. The moisture content did not show any significant proportionality to the change of burst strength of boards within this experiment. 5. Board reconditioning in standard condition led to the recovery of the strength loss that had occurred under various load and humidity condition. 6. The handsheets prepared from the boards that had experienced compressive load and cyclic humidity, and those with no-load and 65% RH did not show any significant difference in strength properties. No physical damage or load-carrying properties of the wood fiber were observed by the compressive load and cyclic humidity history.

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Electro-Active-Paper Actuator Made with LiCl/Cellulose Films: Effect of LiCl Content

  • Wang, Nian-Gui;Kim, Jae-Hwan;Chen, Yi;Yun, Sung-Ryul;Lee, Sun-Kon
    • Macromolecular Research
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    • v.14 no.6
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    • pp.624-629
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    • 2006
  • The cellulose-based, Electroactive Paper (EAPap) has recently been reported as a smart material with the advantages of lightweight, dry condition, biodegradability, sustainability, large displacement output and low actuation voltage. However, it requires high humidity.. This paper introduces an EAPap made with a cellulose solution and lithium chloride (LiCl), which can be actuated in room humidity condition. The fabrication process, performance test and effect of LiCl content of the EAPap actuator are illustrated. The bending displacement of the EAPap actuators was evaluated with actuation voltage, frequency, humidity and LiCl content changes. At a LiCl/ cellulose content of 3:10, the displacement output was maximized at a room humidity condition. Even though the displacement output was less than that of a high humidity EAPap actuator, the mechanical power output was not reduced due to the increased resonance frequency, which is promising for developing EAPap actuators that are less sensitive to humidity.

A Study on Performance of Thermo-Humidity Indicator Card for Measuring Thermo-Humidity of Work Surface (자재 시공면의 온습도 측정을 위한 간이 온.습도 측정지의 성능 연구)

  • Heo, Jung-Yong;Choi, Chang-Ho;Lee, Yun-Gyu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.4
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    • pp.236-242
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    • 2009
  • In finishing work, defects are often taken place by many factors. One of them is the thermo-humidity condition on the work surface as coating and anointing adhesives. Thus, the condition of thermo-humidity on work surface should be checked prior to the finishing work. However, many construction companies show a tendency to overlook it because not only are measurement tools so expensive but they don't have skilled hands about those tools. Therefore, we propose the measurement method that makes it easy to recognize surface thermo-humidity condition so as to reduce constructional flaws. And then we test this product. The test progresses to four stages with various conditions. We evaluate its usefulness and application possibility of this product in the field.

A study on indoor environmental elements of the granite model dome in different envelope materials during summer season (하절기, 석재 모형돔의 외피 유형별 실내환경 요소에 관한 연구)

  • 공성훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.6
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    • pp.898-902
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    • 1999
  • During summer season, the weather condition of Korea is hot and humid. So humidity elements are very important relating to building envelope condition. The purpose of this investigation is to measure and analyze characteristics of summer's environmental elements such as relative humidity, dry bulb temperature and air velocity in the clay/cement envelope materials using a granite dome model. According to the variation of exterior humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

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Effects of the Electrical Characteristics of Capacitive Relative Humidity Sensor by Polyimide Film and Upper Electrode Grain by Sputtering Method (폴리이미드 박막과 스퍼터링 방법으로 증착한 상부금속 그레인이 용량형 습도센서의 전기적 특성에 미치는 영향)

  • Lee, Jin-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.3
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    • pp.224-228
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    • 2011
  • This research, integratable capacitive relative humidity sensor was produced using polyimide on glass substrate. Also, at the time of upper electrode formation, upper electrode grain size was affected by giving changes to sputtering condition. Through this analyzing electrical characteristics affect from capacitive relative humidity sensor was possible. Capacitance of capacitive relative humidity sensor was 330 pF, linearity of 0.6%FS and it showed less than 3% of low hysterisis. Specially, hysterisis was affected more from interface than interstitial. Also was affected by the grain size which is one of the formation condition of upper electrode.

Development of a Refrigeratory-Based Dehumidifier for Humidity Environment Control in Greenhouse (시설원예 습도환경 제어를 위한 냉각식 제습기 개발)

  • Kang, G.C.;Yon, K.S.;Ryou, Y.S.;Kim, Y.J.;Kang, Y.K.;Paek, Y.
    • Journal of Biosystems Engineering
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    • v.32 no.4
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    • pp.247-255
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    • 2007
  • During the winter season in Korea, the relative humidity of greenhouse at night often exceeds 90% because air temperature inside the greenhouse is usually controlled using a heater with all of windows closed to minimize heat loss, thereby requiring the use of a dehumidifier that can maintain optimum humidity levels of $70{\sim}80%$ to provide a good growth condition of crops. Also, such a high humid condition can cause the development of a pest, such as insects, fungi or diseases. However, the use of most conventional dehumidifiers for low temperature dehumidification is limited because their performance is degraded due to frost accumulation on the evaporator coil. This study was carried out to develop a refrigeratory-based dehumidifier suitable for low temperature dehumidification in greenhouse cultivation. The developed dehumidifier consists of a condenser and an evaporator installed separately so that relative and absolute humidity levels can be reduced when air passed through the condenser and evaporator, respectively. The prototype dehumidifier showed a dehumidification capacity of $5{\sim}7kg/h$ when air with a temperature of $15{\sim}25^{\circ}C$ and a relative humidity of $70{\sim}95%$ came into the dehumidifier. Under the condition that either temperature or relative humidity was fixed, the amount of condensed water was proportional to the levels of both temperature and relative humidity.

An Experimental Study of Verification for PEMFC's 1-Dimensional Simulation (PEMFC 1차원 시뮬레이션 검증을 위한 실험적 연구)

  • Moon, Cheor-Eon;Ahn, Seong-Yool;Yang, Jang-Sik;Choi, Gyung-Min;Kim, Duck-Jool
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.191-195
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    • 2007
  • In this study, we estimated the performance of PEMFC's unit cell as changing operating temperature in different inlet humidity condition at cathode side but anode dry, and tried to match experimental results with 1-dimensional simulation. We used $Nafion^{\circledR}112$ membrane and a self-manufactured PEMFC with active area of $25cm^{2}$ was used in this study. The range of operating temperature was $40{\sim}70^{\circ}C$ and oxygen through bubbled humidity chamber was supplied $0{\sim}80$% humidity condition as changing water temperature in humidity chamber. For figuring out governing equations, represent water contents in electrolyte membrane, the linear forward difference method was applied about time progress and quadratic central difference method was used about space progress. It was assumed that pressure terms were linearly changed due to thin electrolyte membrane. In low operating temperature condition, $40{\sim}60^{\circ}C$, increasing temperature rarely effected cell performance but we can see performance drop at $70^{\circ}C$. By modifying Henrry's constant and/or diffusion coefficient, the modified one-dimensional model was accomplished for calculation.

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A Survey on the Sanitary Condition of Kitchens in School Food-service Programs (일부 학교급식소 조리실의 위생관리에 관한 조사연구)

  • 김종규
    • Journal of Environmental Health Sciences
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    • v.29 no.2
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    • pp.87-93
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    • 2003
  • A survey including an inspection was conducted to assess the sanitary condition of kitchens in the school food-service programs and to prepare background data for improving the safety of school meals. The survey was carried out over a two-month period (September-October, 2001). A self-administered questionnaire recommended by the Korea Ministry of Education & Human Resources Development (MOEHRD) was offered to a random sample of dieticians of twenty-five elementary schools in one region of Korea about food, sanitation, and safety inspection of their kitchens. Air temperature, relative humidity, and airborne microbes in the kitchens were monitored during preparation, cooking, and service. The inspection results showed their sanitary rendition met the level B of the recommendation of the Korea MOEHRD. The range of air temperature of the kitchens was 21.4~22.4$^{\circ}C$. and the range of relative humidity was 62.4~69.6%. The microbiological evaluation of kitchen samples indicated aerobic plate count levels from 22..5 to 26.5 CFU/15 minutes. Although the results of inspection show that the levels of sanitary condition of kitchens in the schools were good, they are not satisfactory for safe food-servile because the temperature and humidity levels are high. This study indicates that the school kitchens should be monitored and strict inspection is necessary. The legal standards for school food-service should include standards for kitchen air temperature, relative humidity, and airborne microbes.