• Title/Summary/Keyword: Room Constant

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A Study for Automatic Temperature Control of the Heating-Cooling System with Heat Pump (히트펌프 냉·난방 시스템의 온도 자동제어에 관한 연구)

  • Koo, Chang-Dae
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.4
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    • pp.143-149
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    • 2011
  • The experiment has been investigated the room temperature change under adjusting 4-way valve which was installed for cooling and heating switch. Beside, the temperature of heat pump was controlled automatically for autonomously adjusting temperature and maintaining a constant room temperature. As results, Inlet & outlet temperature differences of compressor are $95^{\circ}C$ in cooling condition and $57^{\circ}C$ in heating condition. Therefore, Compression efficiency of cooling effect is higher than heating effect. In addition, Heat exchange effect of Cooling system condition is higher than heating system. This results can be used for studying about automatic temperature control of cooling and heating system with heat pump and 4way valve.

A Study of BaTiO3 Synthesis by Direct Wet Process (BaTiO3의 습식 직접 합성(I))

  • 이경희;이병하;이희승
    • Journal of the Korean Ceramic Society
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    • v.21 no.4
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    • pp.323-326
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    • 1984
  • In this study we are going to develop the process of a synthesis about BaTiO3 at the room temperature. We use BaTiO3 as a high dielectric constant in many dielectric materials and more stable in the temperature, We need high temperature over 1300$^{\circ}C$ for the synthesis of BaTiO3 by the process of industrials and there are difficulty which synthesize a final products not to have a intermediate composition. So we studied to synthesize a pure BaTiO3 from the room temperature to 90$^{\circ}C$ and also to develop the process of synthesis which can control the particle size and which has the final product not to have a intermediate composition.

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Comparison of Warm Deep Drawability of Stainless Sheet Between Crank Press and Hydraulic Press (크랭크 프레스와 유압 프레스에서 스테인리스 강판의 온간 드로잉성 비교)

  • 김종호;최치수;나경환
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1995.03a
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    • pp.178-185
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    • 1995
  • Warm deep drawing for optimum forming conditions to give the maximum drawing depth is investigated and compared with the results at room temperature. Experiments which draw square cups of STS 304 stainless steel sheet under the constant lubrication condition of teflon film made both in a crank and hydrqulic press for two kinds of specimens . The maximum drawing depth at warm forming condition reaches 1.4 times the drawing depth at room temperature in a crank press, whereas 1.6 times in a hydrqulic press, and also more uniform distribution of thickness in case of warm deep drawn cup is observed. The effects of other factors on formability , such as forming temperature, speed of press and cooling of punch are examinnied and discussed.

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Comparison of Warm Deep Drawability of Stainless Steel Sheet Between Crank Press and Hydraulic Press (크랭크 프레스와 유압 프레스에서 스테인리스 강판의 온간 드로잉성 비교)

  • Kim, Jong-Ho;Choi, Chi-Soo;Na, Kyoung-Hoan
    • Transactions of Materials Processing
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    • v.4 no.4
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    • pp.345-352
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    • 1995
  • Warm deep drawing for optimum forming conditions to give the maximum drawing depth is investigated and compared with the results from experiments performed at room temperature. Experiments which draw square cups of STS 304 stainless steel sheet under the constant lubrication condition of teflon film are made both in a crank and hydraulic press for two kinds of specimens. The maximum drawing depth at warm forming condition reaches 1.4 times the drawing depth at room temperature in a crank press, whereas 1.6 times in a hydraulic press, and also more uniform distribution of thickness in case of warm deep drawn cup is observed. The effects of other factors on formability, such as forming temperature, speed of press and cooling of punch are examined and discussed.

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Effects of Gamma-Irradiation on Cooking Property of Black Soybeans (검정콩의 조리특성에 관한 감마선조사의 영향)

  • 김종군
    • Journal of the Korean Home Economics Association
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    • v.30 no.3
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    • pp.119-129
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    • 1992
  • Black soybeans were gamma-irradiated at dost levels of 0, 2., 5, 10 and 20 kGy, and stored at room temperature for the experiments associated with cooking quality. The degree of cooking of soybeans in boiling water at 98-10$0^{\circ}C$ has been determined by measuring the maximum cutting force of cotyledon. The cutting force to reach a complete cooking was about 120~130g/g. Irradiation at 2.5~20kGy caused the reduction of cooking time in black soybeans by 30~60% compared to the nonirradiated control, and the cooking rate constant of the irradiated samples was higher than that fo the nonirradiated control sample. These results were similarly found in the stored samples for one year at room temperature after irradiation. Color characteristics of cooked samples showed no significant difference between the nonirradiated control and 5 kGy-irradiated sample. After complete cooking of black soybeans, there were not significant in the organoleptic qualities between the nonirradiated and irradiated samples.

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A Study of Flow Characteristics through the Speed Control and Flow Resistance (유로저항에따른 속도제어를 통한 Zone별 유량특성 연구)

  • Oh, Byung-Kil;Kim, Hway-Suh
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.11
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    • pp.762-768
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    • 2011
  • We use floor radiant heating system in the house of commons in winter Floor radiant heating system, which transfer heat by radiation, is one of the energy efficient and comfortable systems that. Floor radiant heating system is configured to be controlled by the room for energy-saving. Proper flow rate to a comfortable heating in the room is important. However, Using a constant speed circulation pump in separate rooms, heating system may cause an imbalance because of the difference of length of coil when operating in the rooms. In this study, our Research team examined heating imbalance due to the variation length through the coil length changes and flow control of the circulation pump.

Fabrication and characterization of $SnO_2$ anode thin film for thin film secondary battery (박막형 2차전지용 $SnO_2$음극 박막의 제작 및 특성 평가)

  • 이성준;신영화;윤영수;조원일
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.571-574
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    • 2000
  • In this study, Tin oxide thin film for secondary battery was deposited on Pt/Ti/Si(100). It was fabricated by r.f. reactive sputtering with Tin metal target. At constant power (130W), pressure (Base 5$\times$10$^{-6}$ Torr, working 5$\times$10$^{-3}$ Torr) and at room temperature, it was fabricated by Ar/O2 gas ratio. After deposition, we got AFM & SEM to investigated surface of thin films and had XRD to find crystalline of thin films. Charge/discharge characteristics were carried out in 1M LiPF$_{6}$ , EC:DMC = 1:1 liquid electrolyte using lithium metal at room temperature.

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Analysis of Electro-magnetic Wave radiating from an Ignition Plug and High-voltage Cable inside an Engine Room (자동차의 점화 플러그와 고압 케이블에서 발생하는 전자파에 대한 해석)

  • 최광제;조시기;정원락;장성국;강신한
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.209-215
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    • 2004
  • This paper presents the frequency range and an analysis method to find the dominant source of electro-magnetic wave which originates from a spark ignition in engine room. Applying the distributed constant equivalent circuit theory the radiation of probable electro-magnetic wave around an ignition plug and a high voltage cable is studied analytically. Experimental studies are also conducted by measuring the frequency spectrum to obtain the radiating characteristics of electro-magnetic wave. Results from both analytical and experimental studies confirm that an ignition plug and a high voltage cable are dominant sources of electro-magnetic wave and that the radiating frequency is ranged from 1.3[GHz] to 2[GHz] band.

Fabrication and electrochemical characterization of amorphous vanadium oxide thin films for thin film micro-battery by reactive r.f. sputtering (반응성 r.f. 스퍼터링에 의한 마이크로 박막 전지용 산화바나듐 박막의 제작 및 전기화학적 특성 평가)

  • 전은정;신영화;남상철;윤영수;조원일
    • Journal of the Korean Vacuum Society
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    • v.9 no.1
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    • pp.42-47
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    • 2000
  • The amorphous vanadium oxide thin films for thin-film rechargeable lithium batteries were fabricated by r.f. reactive sputtering at room temperature. As the experimental parameter, oxygen partial pressure was varied during sputtering. At high oxygen partial pressures(>30%), the as-deposited films, constant current charge/discharge characteristics were carried out in 1M $LiPF_6$, EC:DMC+1:1 liquid electrolyte using lithium metal as anode. The specific capacity of amorphous $V_2O_5$ after 200cycles of operation at room temperature was higher compared to crystalline $V_2O_5$. The amorphous vanadium oxide thin film and crystalline film showed about 60$\mu$Ah/$\textrm{cm}^2\mu\textrm{m}$ and about 38$\mu$Ah/$\textrm{cm}^2\mu\textrm{m}$, respectively. These results suggest that the battery capacity of the thin film vanadium oxide cathode strongly depends on the crystallinity.

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The Isoflurane Concentration of Precision Vaporizer Goldman Vaporizer According to Room Temperature and Carrier Gas Flow Rate (온도 및 유량에 따른 흡입 마취제 전용 기화기와 Goldman 기화기의 isoflurane 농도 변화)

  • 김성미;장화석;이정선;최치봉;임희란;최준철;김휘율
    • Journal of Veterinary Clinics
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    • v.21 no.3
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    • pp.270-275
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    • 2004
  • Anesthetic machines may be equipped with either a precision or nonprecision vaporizer. A precision vaporizer is designed to deliver an exact concentration of anesthetic agent. Goldman vaporizer is a low-flow, closed-circle circuit with a low resistance vaporizer, in circuit. Vaporizers used within circle system(VIC) are not usually temperature compensated and this is generally thought to be a disadvantage. As the volatile agent is vaporized, heat is extracted from the liquid and temperature decreases. This cooling of the liquid leads to a decrease in concentration of the anaesthetic agent delivered by the vaporizer. The purpose of this study is to examine the mechanical consistency of the delivery of isoflurane from Goldman vaporizer and precision vaporizer at various gas flow rates and temperatures. And we first studied isoflurane concentration according to room temperature changes delivered by a Goldman vaporizer and precision vaporizer using different gas flow. The room temperature of $15^{\circ}C,$ $20^{\circ}C,$ $28^{\circ}C$ and fresh gas flow rates of 0.5, 1.0, 1.5, 2.0, 3.0 l/min were used. The inspired agent concentration was measured using a Datex-Ohmeda multigas analyzer. As rose in room temperature, the isoflurane concentration of precision vaporizer approximated the dial setting. On the other hand, at a dial setting concentration of 5.0 percent the delivered isoflurane concentration of precision vaporizer was more than the dial setting in high temperature. The isoflurane concentration of precision vaporizer remained constant despite the increase in temperature. The isoflurane concentration of Goldman vaporizer was increased with rise in room temperature and decreased with rise in gas flow.