• Title/Summary/Keyword: thermal humidity

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Evaluation of Indoor Air Quality in the Railroad Electric Rolling Stock - Focused on Temperature and Humidity - (철도 전동차내의 실내공기질 평가 - 온도 및 습도를 중심으로 -)

  • Park Duck-Shin;Bae Sang-Ho;Jung Woo-Sung
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.610-615
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    • 2003
  • Electric rolling stock is one of major public transportation because of an increase in population and heavy traffic problems. The passengers under the influenced of indoor air quality such as air temperature, relative humidity and air velocity. Ventilation system on passenger cars should be designed for the health and comfort of the passengers. One of the main aim is to create an acceptable thermal environment without draught problems. The draught sensation increases when the air temperature decreases and the air velocity increases. Airflow in passenger cars is turbulent. Lateral temperature and humidity gradients in the electric rolling stock have been studied. And, the difference in the mean temperature and relative humidity measured at 0.7, 0.9, 1.2, 1.7 m above from the floor.

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Change in flame velocity and combustion with inlet air humidity on the spark ignition engine (스파아크 점화기관의 흡기습도에 대한 화염속도 및 연소의 변화)

  • 김문헌;이성열
    • Journal of the korean Society of Automotive Engineers
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    • v.5 no.4
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    • pp.41-46
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    • 1983
  • The influence of inlet air humidity on the flame velocity and combustion of the spark ignition engine were described experimentally by means of the flame velocity measuring apparatus using ion-current. The flame velocity are greatly influenced air fuel ratio and engine speed, and linealy decrease according to the increasing of inlet air humidity. The flame travell curve is very similar to the rate of mass burned and combustion progressive is estimated mostly by only the rate of mass burned curve. The decreasing of the mean flame velocity is about 0.4m/s for increasing of 0.001 specific humidity and we think the reason is mainly decreasing of thermal conductivity.

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Thermal and Humidity Sensing Properties of Heat Resistant Polyimide Thin Film Manufactured by Dry Process (건식법에 의해 제조된 내열성 폴리이미드박막의 열적특성 및 습도감지특성)

  • Lim, Kyung-Bum;Kim, Ki-Hwan;Hwang, Sun-Yang;Kim, Jong-Yoon;Hwang, Myung-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.1080-1086
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    • 2007
  • The aim of this paper is to establish the optimum fabrication condition of specimens, using the Vapor Deposition Polymerization Method(VDPM), which is one of modesto prepare functional organic thin films using a dry process, and to develop a thin film type humidity sensor which has good humidity sensitive characteristics. The inner part of the film became denser and roughness of the film surface eased as curing temperature increased so that thickness of the film could be made uniform. This also shows the appropriate curing temperature was $250^{\circ}C$. The basic structure of the humidity sensor is a parallel capacitor which consists of three layers of Aluminum/Polyimide/Aluminum. The result of SEM and AFM measurement shows that the thickness of PI thin films decreased and the refraction increased as curing temperature increased, which indicates that a capacitance-type humidity sensor utilizing polyimide thin film is fabricated on a glass substrate. The characteristics of fabricated samples were measured under various conditions, and the samples had linear characteristics in the range of 20-80 %RH, independent of temperature change, and low hysteresis characteristic.

Effect of Phenolic Resin According to Relative Humidity on Submerged Entry Nozzle with ZrO2-C System in Fabrication Process (ZrO2-C계 침지노즐 제조시 상대습도에 따른 바인더용 페놀수지의 영향)

  • Yoon, Sang-Hyeon;Kim, Jang-Hoon;Kim, Ju-Young;Lee, Hee-Soo;Koo, Young-Seok
    • Journal of the Korean Ceramic Society
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    • v.48 no.4
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    • pp.293-297
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    • 2011
  • The thermodynamic behavior of phenolic resin was investigated to verify the relation between the properties of porous ceramics with $ZrO_2$-C system for submerged entry nozzle and the characteristics of phenolic resin with various relative humidity. The green and the sintered density were decreased between 25% and 50% relative humidity, whereas they were gradually enhanced above 50% relative humidity. The highest value of apparent porosity was 20.1% and the minimum compressive strength was 69MPa in the specimen using the powder exposed to 50% relative humidity. As a result of thermal analysis for phenolic resin, the shift of endothermic peak to low temperature and the reduction of exothermic peak were observed, and the peaks corresponded to melting and curing of phenolic resin, respectively. The melting and the curing of phenolic resin generate the change of green density, and it can affect the properties of submerged entry nozzle.

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.

Preparation of New Polyelectrolyte/ Silver Nanocomposites and Their Humidity-Sensitive Properties

  • Park, Min-Su;Lim, Tae-Ho;Jeon, Young-Min;Kim, Jong-Gyu;Gong, Myoung-Seon;Joo, Sang-Woo
    • Macromolecular Research
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    • v.16 no.4
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    • pp.308-313
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    • 2008
  • A simple strategy was developed based on polyelectrolyte/silver nanocomposite to obtain humidity-sensitive membranes. The major component of a humid membrane is the polyTEAMPS/silver nanocomposite obtained by thermal heating the mixture of a polyelectrolyte and silver isopropylcarbamate complex. Humidity sensors prepared from polyTEAMPS/silver (w/w=100/0 and 100/6) nanocomposites had an average impedance of 292, 8.83 and $0.86\;k{\Omega}$, and 5,327, 140 and $0.93\;k{\Omega}$ at 30,60 and 95% relative humidity (RH), respectively. Hysteresis, temperature dependence and response time were also measured. Activation energies and complex impedance spectroscopy of the various components of the polyelectrolyte/silver nanocomposite films were examined for the humidity-sensing membrane.

A Study on Thermal Behavior and Reliability Characteristics of PCBs with a Carbon CCL (카본 CCL이 적용된 PCB의 열거동 및 신뢰성 특성 연구)

  • Cho, Seunghyun;Kim, Jeong-Cheol;Kang, Suk Won;Seong, Il;Bae, Kyung Yun
    • Journal of the Microelectronics and Packaging Society
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    • v.22 no.4
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    • pp.47-56
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    • 2015
  • In this paper, the Thermal behavior and reliability characteristics of carbon CCL (Copper Claded Layer), which can be used as the core of HDI (High Density Interconnection) PCB (Printed Circuit Board) are evaluated through experiments and numerical analysis using CAE (Computer Aided Engineering) software. For the characterization of the carbon CCL, it is compared with the conventional FR-4 core and Heavy Cu core. From research results, the deformation amount of the flexure strength of PCB is the highest with pitch grade carbon and thermal behavior of PCB is lowest as temperature increases. In addition, TC (Thermal Cycling), LLTS (Liquid-to-Liquid Thermal Shock) and Humidity tests have been applied in the PCB with carbon core and the reliability of PCB with carbon core is confirmed through reliability tests. Also, possibility of uneven surface of the via hole and wear of the drill bit due to the carbon fibers are analyzed. surface of the via hole is uniform, the surface of the drill bit is smooth. Therefore, it is proved that the carbon CCL has the drilling workability of the same level as conventional core material.

Studies on the Thermal Insulation Effect of Bedding ( I ) - Warmth Retaining Property of Filling Material - (이부자리의 보온력에 관한 연구( I ) -충전물의 보온성 -)

  • Lee Song-Ja;Sung Su-Kwang
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.3 s.43
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    • pp.251-256
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    • 1992
  • As a basic expriment to find out the thermal insulation effect of bedding KES-F7 was used to measure. The warmth retaining ratio of the six kinds of filling materials as cotton, wool , silk, down, cotton/polyester was measured, and the infleunce on the warmth retaining ratio of the warmth retaining ratio and humidity by the material was investigated. The results obtained are as follows: 1. The warmth retaining ratio of each filling material was shown to range from $70\%$ to $77\%$ . The warmth retaining ratio of each material preyed to be high in order down> polyester> cotton/polyester>cotton>silk>wool fiber. 2. The warmth retaining ratio of each filling material decreased with the inclose of the humidity The effective reduction rate by filling fiber's was high in order wool>cotton>cotton/polyester>silk>down>polyester material. 3. The warmth retaining ratio of each filling material was shown to be in counter-correlation with the humidity, and the correlation coefficient (r=0.94-0.98) proved to be highly signi-ficant.

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A Study on the Estimation of Temperature, Humidity and Cooling Load (온도, 습도 및 냉방부하 예측에 관한 연구)

  • Yoo, Seong-Yeon;Han, Seung-Ho;Lee, Je-Myo;Han, Kyou-Hyun;Noh, Kwan-Jong
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.80-85
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    • 2006
  • The peak demand of electricity in summer season mainly comes from the day time cooling loads. Ice thermal Storage System (ITSS) uses off-peak electricity at night time to make ice for the day time cooling. In order to maximize the use of cold storage in ITSS, the estimation of day time cooling load for the building is necessary. In this study, we present a method of cooling load estimation using 5 years of normalized outdoor temperature, relative humidity, and the building construction data. We applied the hourly-based estimation to a general hospital building with relatively less sudden heat exchange and the results are compared with the measured cooling load of the building. The results show that the cooling loads estimation depends on the indoor cooling design temperature of the building.

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Effects of the mosture and thermal annealing on CLBO crystal

  • Mori, Yusuke;Sasaki, Takatomo
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.06a
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    • pp.125-129
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    • 1997
  • The effects of the moisture and thermal annealing on CLBO crystal have been investigated. CLBO has hydrated at high humidity condition, resulting in 5B$_2$O$_3$$.$Cs$_2$O$.$8H$_2$O. The surface hydration seems to induce the cracking and the refractive index change in CLBO. The thermal annealing is effective to restore the changed index.

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