• Title/Summary/Keyword: humidity effect

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A Study on the Effect of Polyetherimide Surface Treatment on the Adhesion and High Temperature/High Humidity Reliability of MCM-D Interface (Polyetherimide 접착제의 표면 처리에 따른 MCM-D 계면 접착력 및 고온고습 신뢰성 변화에 관한 연구)

  • Yoon, Hyun-Gook;Ko, Hyoung-Soo;Paik, Kyung-Wook
    • Korean Journal of Materials Research
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    • v.9 no.12
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    • pp.1176-1180
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    • 1999
  • The adhesion strength and high temperature/high humidity reliability of polyetherimide (PEI) adhesive on silicon wafer after being treated by each reactive ion etching (RIE) Aluminum (Al)-chelate adhesion promoter were investigated. 180$^{\circ}$ peel test and <85$^{\circ}C$ 85%> humidity test were performed for the initial adhesion strength and high temperature/high humidity reliability, respectively. For investigating surface effect scanning electron microscope (SEM), atomic force microscope (AFM), deionized (DI)-water contact angle studies were carried out. To investigate RIE effect, PEI was treated with $^O_2$ RIE, and then laminated. The initial peel strength increased slightly from 1.6 kg/cm for the first 2 minutes, and then decreased. High temp/high humid resistance decreased rapidly by RIE etching. RIE treatment on PEI affected on both of roughness and hydrophilicity increase. Aluminum-chelate adhesion promoter was coated by spinning on silicon wafer. The initial peel strength showed no effect of adhesion promoter treatment, but high temp/high humidity resistance increased remarkably. Al-chelate adhesion promoter did not affect the roughness but increased hydrophilicity.

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Control of relative humidity in the static bag emission test method by adding water and its effect on formaldehyde emission intensity (백을 이용한 정적 방출시험 방법에서 수분공급을 통한 상대습도조절과 포름알데하이드의 방출강도에 미치는 영향)

  • Park, Cheol-Soon;Yoo, Ji-Ho;Kim, Man-Goo
    • Analytical Science and Technology
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    • v.24 no.4
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    • pp.282-289
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    • 2011
  • Rapid screening method for the determination of the emissions of pollutants from vehicle interior parts and materials have been developed as ISO 12219-2 which is using bag and based on a static condition. The method was not controlled humidity in the test bag, so it is not suitable test method for formaldehyde emission test which is highly related to humidity condition. In this study, possibility of control humidity in the static test bag by adding extra water and the effect of humidity condition for formaldehyde emissions have been investigated. The relative humidity in the test bag was affected not only amount of water added also material of test bag and test specimen. The emission intensity of formaldehyde was increased according to increasing relative humidity in test bag. But excessively supplied water was condensed on the inner surface of test bag and surface of sample specimen that were sorption formaldehyde and were reduced its emission intensity.

A Study of Humidification Method in PEMFC (고분자전해질형 연료전지의 가습 방법에 대한 연구)

  • Hyun, Deok-Su;Kim, Jun-Bom
    • Journal of the Korean Electrochemical Society
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    • v.6 no.3
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    • pp.212-216
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    • 2003
  • The humidification measurement system designed in laboratory was used to measure relative humidity and temperature of reaction gases passing through internal or external humidifier which was used in proton exchange membrane fuel cell test station. The relative humidity of gases was stabilized after $10\~20$ minutes and thus credibility of data could be assured. The effect of relative humidity on fuel cell performance could be analyzed by humidity measurement system. Extreme caution was needed to avoid humidity sensor mal-function or failure which is probable in experiment of high humidity condition near $100\%$. The amount of water carried by gas through humidifier was increased along the flow rate of gas. However, the extent of increase was lowered at high gas flow rate. These phenomena could be analyzed as residence time effect of gas in humidifier.

A Study on Buffering Effect of Silicagel to Control Relative Humidity in Air-tight Case (밀폐장내(密閉欌內) 실리카겔의 습도조절(濕度調節) 효과(效果) 연구(硏究))

  • Kim, Myoung-nam;Yu, Hei-sun
    • Conservation Science in Museum
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    • v.2
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    • pp.77-82
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    • 2000
  • The purpose of this study is to evaluate the effect of ART-SORB which is commonly used in museums and galleries at home and abroad including National Museum of Korea, so as to collect useful information to control micro-environment. Experiment was conducted in air-tight condition in order to evaluate only the effect of ART-SORB excluding any influence from outside factors. A certain amount of ART-SORB considering the case size and ART-SORB in cassette type were used to evaluate the humidity controlling capability. The result showed that target humidity was reached in 10~17 hours in case of using corresponding amount of ART-SORB to the cubic volume and in 5~6 hours in case of excessive use of cassette type ART-SORB. And it also showed that humidity can be controlled in the range of RH 50~70%. In addition, ART-SORB was excellent at raising humidity at low humidity and poor at high humidity. Therefore, ART-SORB turned out to be an effective humidity buffer for controlling micro-environment of such artifacts as wooden ware, lacquer ware and paintings, which require high humidity. However, unfortunately, there are some difficulties in applying this result to real condition, given the fact that this study was conducted under firm air-tight case. Therefore, ART-SORB can be fully effective only in firm air-tight case.

A study on the Characteristics of Urban Dryness in Busan (부산의 도시건조화 특성에 관한 연구)

  • Park, Myung-Hee;Lee, Joon-Soo;Suh, Young-Sang;Han, In-Seong;Lee, Hye-Hyun;Kim, Hae-Dong;Bae, Hun-Kyun
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1851-1862
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    • 2014
  • It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and the water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period(1961~2013) in Busan and Daegu. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Busan is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon.

Study on size distribution and characteristics of particulate matter suspension in indoor space depending on relative humidity (상대습도에 따른 비산 미세먼지의 크기 분포 및 특성 분석)

  • Minjeong Kim;Jiwon Park
    • Particle and aerosol research
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    • v.20 no.2
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    • pp.25-33
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    • 2024
  • Suspension of particulate matter (PM) in indoor spaces, which increases risk of negative impact on occupants' health from exposure to PM, is influenced by humidity level in the indoor environment. The goal of this study is to investigate the property of size-resolved PM suspension in accordance with the relative humidity through simulation chamber experiments which reflect the indoor environmental characteristics. The relative humidity of simulation chamber is adjusted to 35%, 55% and 75% by placing it inside a real-size environmental chamber which allows artificial control of climatic conditions (e.g., temperature, humidity). At the respective humidity conditions, PM suspension concentration caused by occupant walking is analyzed by particle size (0.5-0.8, 0.8-1.0, 1.0-2.5, 2.5-3.5, 3.5-4.5, 4.5-5.5, 5.5-8.0, and 8.0-10 ㎛). Irrespective of the particle size, the suspension concentration reveals a decreasing tendency as the relative humidity increases. Furthermore, a one-way analysis of variance (one-way ANOVA) test statistically verifies that the suspension concentration has a significant difference depending on the indoor relative humidity level. In addition, as the relative humidity increases, a proportion of the suspended particles with 0.5-2.5 ㎛ diameter decreases, while that with 2.5-3.5 ㎛ diameter increases. The reason is considered that the humidity has an effect on adhesion and coagulation forces of the particles.

Dynamic Simulation of a Dedicated Outdoor Air-conditioning System (외기 전용 공조기의 동특성 시뮬레이션)

  • Kim, Jung-Min;Kim, Young-Il;Chung, Kwang-Seop;Park, Seung-Tae
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.322-327
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    • 2007
  • Dedicated outdoor air-conditioning(DOA) system that utilizes pre-cooling and desiccant dehumidification can be superior to conventional cooling and reheating system with respect to energy consumption and indoor thermal comfort. In this work, simulation has been conducted to study various factors that affect the performance of DOA. Dynamic simulation shows the transient variation of temperature and humidity as the on/off control logic is imposed. Exit humidity of process air and flow rate are varied to study the effect on exit temperature of process air, dehumidification quantity, required regeneration temperature and exit humidity of regeneration air. For an outdoor air condition of $28.5^{\circ}C$ temperature, 16 g/kg humidity ratio and 2000 cmh flow rate, the dehumidification efficiency is increased by 4.6% as the flow rate is doubled.

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Effects of Smokehouse Humidities on Quality Characteristics of Canadian Bacon (훈연상대습도가 Canadian Bacon 품질특성에 미치는 영향)

  • Park, Tae-Kyu;Lee, Keun-Taik
    • Korean Journal of Food Science and Technology
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    • v.21 no.5
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    • pp.662-668
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    • 1989
  • The effect of four different humidities during smokehouse processing on cured color development color intensity, pH, residual nitrite, phenol deposition, TBA value and product yield of Canadian bacon was determined. High humidity resulted in high pigment conversion and lower pH. As the humidity was lowered, more residual nitrite remained, The highest humidity had the highest phenol deposition and TBA value. The lowest humidity had the highest yield.

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Characteristics of SAW humidity sensor using nanocrystalline ZnO films

  • Hong, Hoang-Si;Chung, Gwiy-Sang
    • Journal of Sensor Science and Technology
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    • v.19 no.5
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    • pp.337-341
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    • 2010
  • In this work, the nanocrystalline ZnO/polycrystalline(poly) aluminum nitride(AlN)/ Si-layered structure was fabricated for humidity sensor applications based on surface acoustic wave(SAW). The ZnO film was used as a sensitive material layer. The ZnO and AlN(0002) were deposited by a sol-gel process and a pulse reactive magnetron sputtering, respectively. The ZnO sensitive films coated on AlN have a hexagonal wurtzite structure after the thin films annealed at $400^{\circ}C$, $500^{\circ}C$ and $600^{\circ}C$. The surface of the film exhibits sponginess and a nanometer particle size(below 50 nm). The largest shift in the frequency response was at approximately 200 kHz(the relative humidity: 10 %~90 %) for the structure annealed at $400^{\circ}C$. The effect of the change in the environmental temperature on the frequency response of the SAW humidity sensor was also investigated.

A spectroscopic study of the effect of humidity on the atmospheric pressure helium plasma jets

  • Han, Duksun
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1375-1380
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    • 2018
  • Atmospheric-pressure plasma has a great potential in many applications due to its simplicity rather than low pressure plasmas. In material processing, biomedical applications, and many other applications, the input power, gas flow rate, and the geometry of electrode have been mainly considered and studied as important external parameters of atmospheric-pressure plasma control. Besides, since the atmospheric-pressure plasmas are typically generated in an open air, the relative humidity is difficult to control and can change day by day. Therefore, the relative humidity cannot be ignored for plasmas. Thus, in this work, the atmospheric-pressure plasma jet was characterized by changing relative humidity, and it was found that the increase in electron density and OH radicals are due to Penning ionization between helium metastable and water vapors at higher humidity condition.