• Title/Summary/Keyword: humidity condition

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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.

Implications of Temperature and Humidity on the Moulting Patterns and Moulting Survival in the Silkworm, Bombyx mori L.

  • Lakshminarayana, P.;Naik, S.Sanker;Reddy, N.Sivarami
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.1
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    • pp.21-25
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    • 2003
  • The implications of temperature $(25, 30 and 35{\times}1^{\circ}C)$ and relative humidity $(60, 70 and 80{\times}2%)$ on the moulting pattern, moulting duration and moulting survival were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB$_4$D$_2$and their hybrid, $PM{\times}NB_{4} D_{2}$ were reared under experimental conditions under natural day photoperiodic (LD 12:12) condition. Two developmental marker events in the fourth moulting, settling for moult (SM) and completion of moult (CM) occurred at or around the middle of the photophase. The computed mean vector (equation omitted), based on the circular statistics also confirmed the above. Temperature and humidity did not alter the moulting rhythmicity much. However, extreme temperature and humidity conditions reduced moulting survival in PM and $PM {\times}NB_{4} D_{2}$. Further, moulting survival reduced below the economic level in $NB_{4} D_{2}$. The temperature and humidity together seem to exert synergic impact on the moulting survival of the silkworm Bombyx mori, at least in $NB_{4} D_{2}$.

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.

Influence of Temperature and Relative Humidity in Infection of Nosema bombycis (Microsporidia: Nosematidae) and Cross-infection of N. mylitta on Growth and Development of Mulberry Silkworm, Bombyx mori

  • Chakrabarti, Satadal;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.173-180
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    • 2008
  • The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

Implications of Temperature and Humidity on Pupation Patterns in the Silkworm, Bombyx mori L.

  • Lakshminarayana, P.;Naik, S.Sankar;Reddy, N.Sivarami
    • International Journal of Industrial Entomology and Biomaterials
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    • v.5 no.1
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    • pp.67-71
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    • 2002
  • The implications of temperature (25,30 and 35$^{\circ}C$) and relative humidity (60, 70 and 80%) on the pupation patterns were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB4D2 and their hybrid, PM ${\times}4 NB4D2 were reared under experimental conditions under natural day photoperiodic (LD 12: 12) condition. The three developmental marker events viz., larval ripening, pharate pupal formation and pupal formation occurred at or around the beginning of the photo-phase. The computed of mean vector (equation omitted), based on the circular statistics, also confirmed the above. However, the length of mean vector, r and the mean vector angular variance, s varied according to temperature and humidity conditions imposed; the variations being non-significant. Extreme temperature and humidity conditions, however, resulted in reduction in pupation rate (%) for PM and PM ${\times}4 NB4D2. On the other hand, in NB4D2 pupation percentage reduced below the economic level. The temperature and humidity together seems to exert synergic impact on the pupation rate at least in the silkworm Bombyx mori, L.

Temperature and humidity effects on behavior of grouts

  • Farzampour, Alireza
    • Advances in concrete construction
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    • v.5 no.6
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    • pp.659-669
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    • 2017
  • Grouts compared to other material sources, could be highly sensitive to cold weather conditions, especially when the compressive strength is the matter of concern. Grout as one the substantial residential building material used in retaining walls, rebar fixation, sidewalks is in need of deeper investigation, especially in extreme weather condition. In this article, compressive strength development of four different commercial grouts at three temperatures and two humidity rates are evaluated. This experiment is aimed to assess the grout strength development over time and overall compressive strength when the material is cast at low temperatures. Results represent that reducing the curing temperature about 15 degrees could result in 20% reduction in ultimate strength; however, decreasing the humidity percentage by 50% could lead to 10% reduction in ultimate strength. The maturity test results represented the effect of various temperatures and humidity rates on maturity of the grouts. Additionally, the freeze-thaw cycle's effect on the grouts is conducted to investigate the durability factor. The results show that the lower temperatures could be significantly influential on the behavior of grouts compared to lower humidity rates. It is indicated that the maturity test could not be valid and precise in harsh temperature conditions.

Temperature Dependency and Dielectric Properties of Humid XLPE sheet with (계면을 갖는 흡습된 XLPE시료에서의 유전특성과 온도의존성)

  • Kim, Dong-Shick;Lee, Jong-Bok;Hwang, Bo-Seung;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1636-1638
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    • 1999
  • In this paper, humidity and temperature were carried out on XLPE sheet and XLPE/semi sheet. We measured voltage, temperature dependency and dielectric properties of humid dielectric materials. Dielectric losses of XLPE(A,B)/semi with and without humidity were $4.2{\times}10^{-4}$ and $3.6{\times}10^{-4},\;2.8{\times}10^{-4}$ and $3.2{\times}10^{-4}$, respectively, at room temperature. On the condition that humidity and semiconductors exist, we confirmed that dielectric properties had been influenced on semiconductor and humidity.

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Electrostatic Electrification Relaxation Properties of Polyester Rayon Non-woven Fabric due to Weight Variation (중량변화에 의한 폴리에스터 레이온 부직포의 정전기 대전 완화특성)

  • Lee, Sung-Ill;Park, Yong-Soon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.12
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    • pp.977-981
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    • 2011
  • Non-wovens polyester rayon samples were manufactured, and the electrification properties of electrostatics were measured for three different samples (15 g/$m^2$, 25 g/$m^2$, and 40 g/$m^2$) with the environmental settings of temperature (20~40$^{\circ}C$) and humidity (40~90%). The conclusions are as follows. Heavy sample generated more static electricity when the temperature was constant. The static electricity decreased slowly when the humidity is less than 70%, while it sharply decreased over 70% humidity condition. For non-woven polyester rayon, static charge decreased as temperature and humidity increased. As the weight increased, less time were taken for the electrification voltage to drop to the half.

Experiment of frost growth on the parallel plates in the condition of laminar and low humidity (층류유동 저습도 조건에서의 평행평판형 냉각판 서리성장 실험)

  • 한흥도;노승탁
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.4
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    • pp.440-447
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    • 1999
  • The frosting characteristics on the vertical parallel plates with three cooling plates were experimentally investigated. The experimental parameters were the cooling plate temperature, the air humidity, the air temperature, the air Reynolds number, and the location. The frosting conditions were limited to air temperatures from 10 to $15^{\circ}C$ , air Reynolds numbers from 1600 to 2270, air humidity ratios from 0.00275 to 0.0037kgw/kga and cooling plate temperatures from -10 to $-20^{\circ}C$. Frost growth and density toward the front of the plate were more thick and dense than toward the rear. Frost growth increased with decreasing plate temperature and increasing humidity. In the conditions of the laminar flow, dew point below $0^{\circ}C$and non-cyclic frosting period, frost thickness increased with increasing air temperature. The reason of increasing frost thickness with increasing air temperature was sublimation-ablimation process. The average growth thickness along the locations showed little dependence on the Reynolds numbers.

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Effects of Temperature and Humidity on the Friction and Wear Properties of DLC Film on the Hard Disk (하드디스크 DLC 필름의 마찰 마모특성에 대한 온도와 습도의 영향)

  • Ahn, J.Y.;Kim, D.E.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.876-881
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    • 2001
  • DLC(Diamond-like carbon) films possess high hardness, low friction coefficient, and good wear resistance. Due to these properties, DLC films have been used extensively in magnetic hard disk industry. The objective of the present study was to investigate the influence of environmental condition on the tribological behavior of DLC coated hard disk. It is found that the tribological characteristics of DLC films are strongly affected by relative humidity and temperature. Specifically, the friction coefficient increases with increase in temperature at relative humidity of 50%. However, at 20% and 85% RH the effect of temperature was not significant. Also, the degree of wear could be observed using an AFM.

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