• Title/Summary/Keyword: latent capacity

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Energy and Mass Balance of Snowpack - Rapid snowmelt during Fohn events in the Takada plain -

  • ;Shinichi Takami
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.E
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    • pp.88-94
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    • 1990
  • Several models physically based to predict the evolution of the snowpack have been proposed. Validity of these models for hourly estimation is, however, questionable, since they have been tested only on a daily basis. A computational model to predict the amount of snowpack on an hourly basis in terms of snowload from a set of meterological measurements was developed and investigated the rapid snowmelt conditions during Fohn events in the Takada plain.

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Running Characteristics for On-Line Test of Railway Vehicle

  • Han, Young-Jae;Kim, Seog-Won;Seo, Sung-Il;Mok, Jin-Yong;Lee, Su-Gil;Kim, Young-Mo
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1347-1350
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    • 2005
  • Recently, as the road capacity reaches a limit and environmental problems become serious, there exists a gradual increasing need for railway vehicles that are environment-friendly, punctual, reliable and safe. Accordingly, in addition to conventional railroad vehicles, lots of vehicles are being newly developed. Using the developed installed measurement system, the performance characteristics of railway vehicle could be monitored precisely. After recording the input real time data of each signal from railway vehicle to the network line, we could acquire the needed information through post processing program. We could verify the running performances of railway vehicle using this system. As a result, many latent defects have been found and corrected in the prototype train. The measurement systems have contributed to dramatic reduction of the developing period.

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A Study on Human Error for safety improvement in railway industry (철도산업에서 안전성 제고를 위한 인적오류 연구)

  • Heo, Eun-Mee;Byun, Seong-Nam
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.2040-2047
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    • 2010
  • Railway system which has latent loss of lives and property by big accident with that human error such as locomotive driver, manager, signaller, and the others involved. So human error management is needed to control this complex system and to confirm safety of it. Rail human error research for managing human resource has grown rapidly in both quantity and quality of output over the past few years. The continual influences of safety concerns, new technical system opportunities, reorganization of the business, needs to increase effective, reliable and safe use of capacity, and increased society, media and government interest have now accelerated rail human factors research programmes in several countries. The objective of this research is to improve safety and to reduce accidents in korean railway system, through the application of research results to the investigation of requirement for human error.

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Behavior of cryogenic gases in a closed space (밀폐된 공간에서 초저온 액화가스의 거동)

  • 이현철;강형석;박두선;손무룡
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2000.02a
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    • pp.48-51
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    • 2000
  • The behavior of cryogenic liquid stored in a closed cryogenic tank has been studied at various liquid levels, as a function of pressure and temperature on time, assuming heat leak(NER) is 0.7%/day. The pressure depends, as expected, on the liquid-vapor ratio in a tank. The calculation shows that if liquid level is as high as 90%,much higher than the critical volume ration, in a closed tank of designed pressure 11 bar, it takes 5.4 to 15days for the entire volume of the tank to be filled with liquid and 11 to 22 days for the tank to be exploded. If a closed tank is full of liquid, it is extremely dangerous because of abrupt pressure increase so that the safety devices are necessary to vent out pressurized gas. These phenomena can be explained with the liquid heat capacity, latent heat and compressibility.

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Theoretical Analysis on the Heat and Mass Transfer in a Sorption Cool Pad (흡습 냉각 패드에서의 열 및 물질전달에 관한 연구)

  • 황용신;이대영;박봉철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.2
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    • pp.167-174
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    • 2004
  • A sorption cool pad brings cooling effect without any pre-cooling, nor any external energy supply. It uses evaporative cooling effect stimulated by the desiccative sorption. In this paper, heat and mass transfer in the sorption cool pad are investigated theoretically. The evaporative cooling process caused by the desiccant is modeled and analyzed considering the sorption characteristics of the desiccant. Two nondimensional parameters are found to dominate the cooling process: one is related to the psychrometric characteristics and the other is to the sorption capacity of the desiccant. The former decides the time to reach the lowest temperature and the later controls the time duration of the cooling effect being sustained.

Two-Phase Flow Characteristics in an Adiabatic Horizontal Tube (단열 수평관내 이상류의 유동특성)

  • Choi, B.H.
    • Journal of Power System Engineering
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    • v.8 no.1
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    • pp.36-40
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    • 2004
  • Two-phase loop systems using the latent heat capacity of their working fluids can meet the increasing power requirements and are well suited to thermal management systems of future large applications, due to its abilities to handle large heat loads and to provide them at uniform temperatures regardless of the changes in the heat loads. Therefore some experiments on the effect of the gas and liquid superficial velocities, $j_G,\;j_L$ on flow pattern transition, void fraction and frictional pressure loss were performed on a co-current air-water flow in an adiabatic horizontal tube. The flow patterns were depended on the superficial velocity of each phase. It snowed that the increasing $j_L$, resulted in a significant increase in the frictional pressure loss for all flow patterns, at a constant $j_G$. The experimental results were also evaluated with some of existing models and correlations.

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Growth of Ice Crystal with Concentration of Surfactant in Water Solution (계면활성제 농도가 빙결정의 입자크기에 미치는 영향)

  • ;稻葉英男
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.2
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    • pp.240-247
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    • 2002
  • Recently, a thermal energy storage system has been developed actively fur the purpose of saving energy and reducing the peak electrical demand. Especially, ice slurry is a promising working fluid for low temperature energy storage systems. A flow of ice crystals has a large cooling capacity as a result of the involvement of latent heat. However, there are still problems related to the recrystallization of ice crystals for realizing long term storage and long distance transportation. To find improvements fur this, a method for the creation of ice crystals resistant to recrystallization has been proposed and researched by the use of an antifreeze protein (AFP) solution etc. In the present study, it has been investigated the growth of ice crystal in several kinds of water solution added non-ionic surfactant. The results shows that size of ice crystal was smaller with increasing in added surfactant. And ice crystal was not increased with added surfactant.

Big Data Analysis of Weather Condition and Air Quality on Cosmetics Marketing

  • Wang, Zebin;Wu, Tong;Zhao, Xinshuang;Cheng, Shuchun;Dai, Genghui;Dai, Weihui
    • Journal of Information Technology Applications and Management
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    • v.24 no.3
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    • pp.93-105
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    • 2017
  • Demands of cosmetics are affected not only by the well-known elements such as brand, price, and customer's consumption capacity, but also by some latent factors, for example, weather and air environment. Due to complexity and dynamic changes of the above factors, their influences can hardly be estimated in an accurate way by the traditional approaches such as survey and questionnaires. Through modeling and statistical analysis of big data, this article studied the impacts of weather condition and air quality on customer flow and sales of the cosmetics distributors in China, and found several hidden influencing factors. It provided a big-data based method for the analysis of unconventional factors on cosmetics marketing in the changing weather condition and air environment.

Rx for Tissue Restoration: Regenerative Biology and Medicine

  • Stocum, David L.
    • Animal cells and systems
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    • v.5 no.2
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    • pp.91-99
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    • 2001
  • Vertebrates regenerate tissues in three ways: proliferation of cells that maintain some or all of their differentiated structure and function, redifferentiation of mature cells followed by proliferation and redifferentiation into the same cell type or transdetermination to another cell type, and activation of restricted lineage stem cells, which have the ability to transdetermine to different lineages under the appropriate conditions. The behavior of the cells during regeneration is regulated by growth factors and extracellular matrix molecules. Some non-regenerating tissues are now known to harbor stem cells which, though they form scar tissue in vivo, are capable of producing new tissue-specific cells in vitro, suggesting that the injury environment inhibits latent regenerative capacity. Regenerative medicine seeks to restore tissues via transplantation of stem cell derivatives, implantation of bioartificial tissues, or stimulation of regeneration in vivo. These approaches have been partly successful, but several research issues must be addressed before regenerative medicine becomes a clinical reality.

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The Effects of Additives on the Thermal Properties of a Clathrate Compound(I) -The Case of Ethanol- (포접화합물의 열물성에 미치는 첨가제의 효과(I) -TMA 물계 포접화합물에 Ethanol을 첨가한 경우-)

  • 김진흥;정낙규;김석현;김창오;강승현
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.3
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    • pp.258-264
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    • 2004
  • The ice thermal storage system is to use consolation latent heat of water. But, supercooling phenomenon of water during phase change is to increase the cooling capacity and to decrease COP of the refrigerator. Furthermore, this causes the operation cost of system to increase and the efficiency of energy to decrease. Therefore, the better thermal storage material than the water is required. The purpose of this study is to improve supercooling characteristics and thermal properties of TMA 30wt% clathrate by using Ethanol.