• Title/Summary/Keyword: Discharge of cold

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Characteristics of Storage Tank on Harvest Type Ice Storage System (하베스트형 빙축열시스템의 축열조 특성)

  • Choi, In-Su;Lee, Ho-Saeng;Moon, Choon-Geun;Kim, Jae-Dol;Yoon, Jung-In
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.210-215
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    • 2000
  • A fundamental study on the under water harvest-type ice storage system and its temperature characteristics in ice storage system was performed experimentally. The experiments were conducted by changing the inlet refrigerant temperature of an evaporator to analyzing the thermal fluid motion inside the ice storage tank. From the experimental results, the cold storage characteristics were investigated by measuring the axial and radial temperature variations inside the ice storage tank with respect to the inlet and outlet refrigerant temperatures of an evaporator. In case of the under water harvest-type ice storage system, thermal fluid motion inside the ice storage tank was shown differently in comparison with that of other ice storage systems. During the cooling storage process, there was no supercooling phenomenon in the ice storage tank. These results show the characteristic of this system and the possibility of application to other fields.

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Experimental Study on the Performance Characteristic in Underwater Harvest-Type Ice Storage System (수중 빙제조형 빙축열시스템의 성능특성 특성)

  • Jang, Yong-Sik;Lee, Ho-Saeng;Choi, In-Su;Kim, Jae-Dol;Kim, Eun-Pil;Yoon, Jung-In
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.298-303
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    • 2001
  • A fundamental study on the under water harvest-type ice storage system and its temperature characteristics in ice storage system was performed experimentally. The experiments were conducted by changing the inlet refrigerant temperature of an evaporator to analyzing the thermal fluid motion inside the ice storage tank. From the experimental results, the cold storage characteristics were investigated by measuring the axial and radial temperature variations inside the ice storage tank with respect to the inlet and outlet refrigerant temperatures of an evaporator. In case of the under water harvest-type ice storage system, thermal fluid. motion inside the ice storage tank was shown differently in comparison with that of other ice storage systems. During the cooling storage process, there was no supercooling phenomenon in the ice storage tank. These results show the characteristic of this system and the possibility of application to other fields.

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A Study on the Effect of Roughness of Rolling Roll in the Paintabilility of Strip (압연롤의 조도가 박판의 도장성에 미치는 영향에 관한 연구)

  • 김순경
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.7
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    • pp.36-43
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    • 1998
  • Surface roughness of cold rolled steel sheet as well as the coating technique itself is quite important in obtaining high image clarity of electronic products and car outer panels. Especially, surface characteristics of steel sheet have acquired increasing attention from the steel and automotive industries. While the influence of such characteristics on paintability formability and painted surface appearance is important in defining steel surface requirements for automotive industries. Therefore this paper is dedicated primarily to the issue of paint appearance and reviews for improvement of roughness and peak count about the surface of work roll for the actual temper mill. The conclusions were obtained as follows ; 1) Roughness and peak count about the surface of steel sheet is strongly affected by surface condition of work roll. 2) The electro-discharge textured roll has more uniform roughness distribution than shot blasted roll and it's painted appearance of steel sheet has more improvement than that of the shot blasted because it has more harmonic wave roughness, and the higher peak count of surface roughness.

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Study of Partial Discharge Influence on AC Breakdown Strength of Laminated Ploypropylene Paper(PPLP) at Liquid Nitrogen (액체 질소에서의 반합성지 AC 파괴 강도에 미치는 부분 방전의 영향)

  • 안드레프;김수연;이인호;김도운;신두성;김상현
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.105-109
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    • 2002
  • The short-term AC breakdown strength of laminated polypropylene insulating Paper (PPLP) has been studied for cold dielectric of high temperature superconductivity power cables. The design and operating conditions of the electrode system for studying of short-term breakdown strength of one-layer and multi-layer PPLP samples are discussed in liquid nitrogen(LN2) state. The influence of various operating factors (geometry and dimension of electrodes, speed of tested voltage, thickness of test sample) on the value of short-term AC breakdown strength at cryogenic temperature has been established.

A Study on Electrostatic Charging Characteristics in Vehicle Fuel Systems (차량 연료시스템에서의 정전기 축적특성 연구)

  • Seo, Joon-Ho;Na, Byung-Chul;Kim, Jin-Young
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2157-2162
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    • 2004
  • As the friction between two mated materials generates electrostatic voltage, vehicles especially in the cold climate has been accumulated an electrostatic voltage by the reason of fuel flow in the fuel line, air flows out side of vehicle, etc. In this study, investigations of electrostatic discharge characteristics has been carried out in the fuel systems of gasoline engines depending on the environment temperature. For the experiment, conventional fuel filters(paint coated steel case) and specially made testing equipment are prepared. The experimental results shows, an accumulation speed of electrostatic voltage depends on the environmental temperature and new methods of testing procedures are required compare to SAE standards.

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A Study on Application of Radix Asari Main Blended Prescription From Dongeubogam (동의보감(東醫寶鑑) 중(中) 세신(細辛)이 주약(主藥)으로 배오(配伍)된 방제(方劑)의 활용(活用)에 대한 고찰(考察))

  • Jeon Ho-Cheol;Rho Euy-Joon;Kim Hyung-Rul;Yun Young-Gab
    • Herbal Formula Science
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    • v.12 no.2
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    • pp.57-76
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    • 2004
  • This report describes the remedial fields, symptoms, pathology, dosage, prescriptional constitution of 69 studies related to the use of Radix Asari main blended prescriptions from Dongeubogam. The following conclusions were reached through investigations on the prescriptions that use Radix Asari as a key ingredient. Radix Asari blended prescriptions are utilized for 14 therapeutic purposes, for example, in symptoms of tooth, eye, paralysis, ear-nose, skin infection and carbuncle. In particular, 14.49% of the prescriptions appear in the chapter of tooth, and 10.14% of those appear in the chapter of eye. Prescriptions that utilize Radix Asari as the main ingredient are used in the treatment of dental disease, othalmology, nose and ear disease, throat disease, common cold, dermothology, paralysis, musculoskeletal disease, disease of the head, asthma, genital disease, the injury of the cuts and they are also used for treating 50 different types of diseases. Radix Asari is used in Six pathogenic factors such as wind, wind-cold, wind-heat, wind-dampness heat, wind-dampness, dampness, paralysis, cold-chill, cold, dryness, in visceral pathogenic factors such as stomach, kidney, liver-kidney, liver and in chi-blood pathogenic factors such as chi-blood deficiency, chi-blood stagnation and in extravasated blood pathogenic factors such as impact injury, an injury such as cuts, blood accumulation as well as weakness-cold and parasites. The actual amount of Radix Asari blended has ranged at a wide variety of amounts from 2.5pun(about 0.94gram) to 3don(about 11.25gram). 26.09% of the prescriptions used 1don(about 3.75gram). The function of Radix Asari is to calm down, to get the consciousness back, to bore through, to warm up the meridians and to run it smoothly, to discharge of phlegm from the combination of drugs and prescriptions.

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Temporal and spatial fluctuation characteristics of sea surface temperature in Yeosu Bay, Korea (여수해만 수온의 시공간적 변동특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.4
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    • pp.322-339
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    • 2020
  • Temporal and spatial fluctuations of surface water temperature in Yeosu Bay for the period from 2010 to 2011 were studied using the data from temperature monitoring buoys deployed at 32 stations in the south coast of Korea. Temperatures in the northern part of the bay are higher in summer and lower in winter than in the southern part of the bay. The lowest and highest temperature of the annual mean are found at the eastern coast of POSCO and at the west of Dae Island, respectively. Cold water masses appear at estuarine area when the discharge of Sumjin river is affluent. Amplitude of temperature fluctuation whose period is less than semi-diurnal is largest at Hadong coast and around Dae Island. Spectral analysis of surface water temperature shows a significant peak at a periodic fluctuation of 0.5 to 24 days and about 15-day period of predominant fluctuation is most frequent in Yeosu Bay. From the cross-correlation analysis of temperature fluctuations, Yeosu Bay can be classified into six areas; the south area affected by South Sea of Korea, the mixed area in the center of the bay, the estuarine area affected by river discharge at the north of the bay, the hot waste water area near Hadong coast, the area around Dae Island and the area near Noryang Channel affected by the water in Jinju Bay, respectively.

A Development of the Low Energy Large Aperture Electron Beam Generator (저에너지 대면적 전자빔 발생장치 개발(II))

  • Woo, Sung-Hun;Lee, Kwang-Sik;Lee, Dong-In;Cho, Chu-Hyun;Choi, Young-Wook;Lee, Hong-Sik;Abroyan, M.
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1767-1769
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    • 1998
  • We have established a pulsed electron beam generation system with an energy of 200[keV], pulse repetition rate of 200[Hz], and several tens of [${\mu}s$] pulse width. The system is characterized by a cold cathode that is simpler than the hot cathode. Target object does not need to be scanned because of large aperture electron beam of 300[$cm^2$]. Electron source is secondary electrons that are generated when the ions from the glow discharge collide on the cathode surface. In this paper, the discharge current characteristics are investigated experimentally as a function of He gas pressure in order to obtain stable glow discharge. And computer simulations are carried out as a preliminary study for the development of low energy large aperture electron beam generator. The variation of electon beam current is investigated as a function of rising time of high voltage when 20[kV] potential is applied in 20[mTorr] pressure.

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A Study on the Electro Discharge Texturing Characteristics of the work Roll for Cold Rolling and Surface Roughgness of Steel Strip (냉간압연용 작업롤의 방전 조도가공 특성과 판 조도에 관한 연구)

  • Kim, Soon-Kyung;Jeon, Eon-Chan;Jun, Tae-ok
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.5
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    • pp.69-76
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    • 1995
  • This paper describes characteristics of EDT(Electro Discharge Texturing) and that the strip surface has influence on the paintability. The pulse mode and the capacitor mode of recently developed EDT method were investigated about the peak shape and the roughness of strip surface. And EDT method compared the above-mentioned contents with the SBT(Shot Blast Texturing) method. The peak count of the pulse mode is more than that of the capacitor mode. But the lower roughness below the Ra 3.2 .mu. m of the strip surface, the texturing time of the pulse mode is longer than the capacitor mode. In SBT method, the peak shape is similar to capacitor mode. But the EDT roll has more uniformity than the SBT roll and has more peak count than that of SBT roll. Therefore, in the painted steel sheet, EDT roll gives better surface of clarity image than the SBT roll.

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An Experimental Study on Flow Characteristics of Cavitation Venturi (캐비테이션 벤츄리의 유동 특성에 대한 실험적 연구)

  • Yoon, Wonjae;Ahn, Kyubok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.4
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    • pp.1-7
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    • 2015
  • A cavitation venturi is a device that allows a liquid flow rate to be fixed or locked independent of a downstream pressure and has been successfully used in a liquid rocket engine system which requires a stable propellant flow rate. In the present research, four cavitation venturis which have same dimensions except for converging inlet angle and diverging outlet angle, were designed and manufactured. Flow rates through each venturi and upstream/downstream pressures were measured by changing the pressures. From the experimental data, the discharge coefficients and critical pressure ratios were calculated for each venturi. It was found that the inlet and outlet angles of the cavitation venturi affected the discharge coefficient, and the outlet angle influenced on the critical pressure ratio.