• Title/Summary/Keyword: engineering room

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An ITO/Au/ITO Thin Film Gas Sensor for Methanol Detection at Room Temperature

  • Jeong, Cheol-Woo;Shin, Chang-Ho;Kim, Dae-Il;Chae, Joo-Hyun;Kim, Yu-Sung
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.2
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    • pp.77-80
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    • 2010
  • Indium tin oxide (ITO) films with a 5 nm thick Au interlayer were prepared on glass substrates. The effects of the Au interlayer on the gas sensitivity for detecting methanol vapors were investigated at room temperature. The conductivity of the film sensor increased upon exposure to methanol vapor and the sensitivity also increased proportionally with the methanol vapor concentration. In terms of the sensitivity measurements, the ITO film sensor with an Au interlayer shows a higher sensitivity than that of the conventional ITO film sensor. This approach is promising in gaining improvement in the performance of ITO gas sensors used for the detection of methanol vapor at room temperature.

The Study of Relationship on Bio-Aerosol with Indoor Temperature Difference (실내 온도차에 따른 부유세균과의 상관관계 연구)

  • Park, Jin-Young;Kim, Sam-Uel;Yun, Jung-Ki
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.737-741
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    • 2008
  • The indoor environment has an effect on heath of human in indoor room that they live largely. We will know Bio-Aerosol that causes illness, such as a flu, an asthma and an atopy etc. and see a relationship between Bio-Aerosol and temperature as an experiment in Air-Conditioned room. In the future, this data can use a basic data for an effect of Bio-Aerosol on indoor environment.

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Room Temperature Chemical Vapor Deposition for Fabrication of Titania Inverse Opals: Fabrication, Morphology Analysis and Optical Characterization

  • Moon, Jun-Hyuk;Cho, Young-Sang;Yang, Seung-Man
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2245-2248
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    • 2009
  • This paper demonstrates room temperature chemical vapor deposition (RTCVD) for fabricating titania inverse opals. The colloidal crystals of monodisperse polymer latex spheres were used as a sacrificial template. Titania was deposited into the interstices between the colloidal spheres by altermate exposures to water and titanium tetrachloride (Ti$Cl_4$) vapors. The deposition was achieved under atmospheric pressure and at room temperature. Titania inverse opals were obtained by burning out the colloidal template at high temperatures. The filling fraction of titania was controlled by the number of deposition of Ti$Cl_4$ vapor. The morphology of inverse opals of titania were investigated. The optical reflection spectra revealed a photonic band gap and was used to estimate the refractive index of titania.

Effect of Room Temperature Ionic Liquids Adsorption on Electromechanical Behavior of Cellulose Electro-Active Paper

  • Mahadeva, Suresha K.;Yi, Chen;Kim, Jae-Hwan
    • Macromolecular Research
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    • v.17 no.2
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    • pp.116-120
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    • 2009
  • The cellulose smart material called electro-active paper (EAPap) is made by regenerating cellulose. However, the actuator performance is degraded at low humidity levels. To solve this drawback, EAPap bending actuators were made by activating wet cellulose films in three different room-temperature ionic liquids: l-butyl-3-methylimidazolium hexaflurophosphate ($BMIPF_6$), 1-butyl-3-methylimidazolium chloride (BMICL) and 1-butyl-3-methylimidazolium tetrafluroborate ($BMIBF_4$). In the results, the actuator performance was dependent on the type of anions in the ionic liquids, in the order of $BF_4$>Cl>$PF_6$. The BMIBF 4-activated actuator showed the maximum displacement of 3.8 mm with low electrical power consumption at relatively low humidity. However, the BMICL-activated actuator showed a slight degradation of actuator performance. Further performance and durability improvement will be possible once various ionic liquids are blended with cellulose.

A Study on the Room Acoustics in Churches (교회 건축물의 실내음향 특성에 관한 연구)

  • 주진수
    • Journal of KSNVE
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    • v.9 no.4
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    • pp.681-686
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    • 1999
  • In a church, speech intelligibility is very important together with the reverberance for musical activities. In order to obtain the primary data of a acoustical design for churches records were refereed and churches were measured in Europe and Japan. And in the base of measurements, those were judged by subjective hearing test. As some results, it has been found that the room acoustics of churches were different in a country and the reverberation time was perferred two seconds for speech intelligibility. However, although personal deviations were admitted, more long echoes were preferred for the music.

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Numerical Simulation on Flows inside an Engine Room with Radiator and Cooling Fan Models (방열기 및 냉각팬을 고려한 엔진룸 내부유동 해석)

  • Kim S. L.;Lee S. C.;Lee K. H.;Hur N.
    • 한국전산유체공학회:학술대회논문집
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    • 1995.10a
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    • pp.70-75
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    • 1995
  • Recently, for the thermal system design in an engine room, the importance of the numerical analysis on the heat and fluid flow has been recognized. In the present study, the flow inside an engine room with complex geometry was analysed by use of TURBO-3D program being developed in KIST. Radiator and Cooling fan were simulated by porous media and momentum sources, and the result shows a good agreement with our expectation.

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Electrochemical properties of PEO-based solid polymer electrolytes blended with different room temperature ionic liquids

  • Kim, Y.H.;Cheruvally, G.;Choi, J.W.;Ahn, J.H.;Kim, K.W.;Ahn, H.J.;Song, C.E.;Choi, D.S.
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.276-276
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    • 2006
  • The incorporation of room temperature ionic liquids (IL) in poly (ethyleneoxide)-lithium salt (PEO-LiX) based solid polymer electrolytes is presently being studied as an effective means of enhancing the room temperature ionic conductivity of these electrolytes to acceptable levels for use in lithium batteries. In the present study, $PEO_{20}-LiTFSI$ solid polymer electrolyte was blended with three different ionic liquids, namely 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMIMTFSI), 1-butyl-3-methylimidazolium tetraflouroborate (BMIMBF4) and 1-butyl-3-methylimidazolium trifluromethanesulfonate ($BMIMCF_{3}SO_{3}$). The incorporation of all these ILs resulted in the enhancement of ionic conductivity, the effect being more pronounced at lower temperatures. Electrochemical properties of the blended electrolytes were studied by cyclic voltammetry, linear sweep voltammetry and interfacial resistance measurements. The optimum results were obtained with the blending of BMIMTFSI in the solid polymer electrolyte.

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Room Temperature Catalytic Ozonation of Methyl Ethyl Ketone over Mesoporous MnOx/Al2O3 Catalysts

  • Reddy, Kannapu Hari Prasad;Park, Youna;Song, JiHyeon;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.32 no.4
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    • pp.483-486
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    • 2021
  • Catalytic ozonation of methyl ethyl ketone (MEK) has been examined over mesoporous MnOx/Al2O3 (MA) catalysts developed by a solvent deficient method using two different manganese precursors including manganese chloride (C) and manganese sulfate (S) at room temperature. The maximum catalytic activities of MA with C (MEK removal efficiency and ozone decomposition of 98.4 and 93.7%, respectively) were higher than those of MA with S (MEK removal efficiency and ozone decomposition of 96 and 68%, respectively). Also the catalytic stability of MA with C was much higher than that of MA with S. The physico-chemical properties of catalysts are well correlated with the activity results, which confirmed that fine dispersion of MnOx species with high ratios of Mn3+/Mn4+ and more acid sites are attributed to the higher catalyst stability for the MA-C catalyst.

A Study on the Phenomena of Dust Removal by the Layout Changes in the Turbulent Type Clean Room (난류형 클린룸내의 Layout 변화에 따른 분진제거 특성에 관한 연구)

  • Kim, Yeon-Hui
    • Journal of the Korea Construction Safety Engineering Association
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    • s.41
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    • pp.80-87
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    • 2007
  • The purpose of this paper is to investigate the removal efficiency of fine dusts as the configuration condition of machinery and equipments in Clean Room and to analyze the flowing behaviors of fine dusts as the layout of Clean Room. The layout of the Clean Room was classified into side layout type, 2 center line type and center concentration type layout, and the flow rates used in this research were 0.22m/s, 0.44m/s and0.80m/s. Dust removal efficiency as layout change was decreased 37% for side layout type, 31% for 2 centerline type and 20% for center concentration type layout at the flow rate of 0.22m/s, compared with the state without machinery and equipments in Clean Room. The efficiency was decreased 42% for side layout type,22% for 2 center line type and 8% for center concentration type layout at the flow rate of 0.44m/s, and decreased 20% for side layout type, 18% for 2 center line type and 10% for center concentration type layout at the flow rate of 0.80m/s. According to the result of dust removal behavior, $0.3\mum$, $1\mum$and $3\mum$dust except for $5\mum$showed the higher change of the behavior in side layout type than in center concentration type layout due to the change of air flow. It was confirmed that removal behavior depends on the layout of machinery and equipments as the dust size decreases.

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An experimental study on the multiple parameter switching control for floor heating system (바닥 난방공간의 다인자 제어에 관한 실험적 연구)

  • Cho, S.H.;Tae, C.S.;Jang, C.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.4
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    • pp.472-483
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    • 1997
  • An experimental facility consisting of two $3{\times}4.4{\times}3.8m$ rooms identical in construction is built. Each room has a control system and storage tank supplying hot water to the radiant floor heating system. The facility enables simultaneous comparision of two different control stratigies each implemented in a separate room. The operating performance of three kinds of flow control scheme is tested and compared in this study : (i) conventional on-off control based on feedback from room air temperature (ii) TPSC(two parameter switching control) (iii) TPOC(two parameter on-off control). Results show that TPSC and TPOC using room air and surface temperature sequentially as feedback signal to control hot water supply is the better temperature regulation scheme than conventional control based on feedback from only room air temperature. They are good candidates for the room with radiant floor heating system under continuous and intermittent heating mode.

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