• Title/Summary/Keyword: flow accumulation

Search Result 351, Processing Time 0.022 seconds

A Study on Mechanism about Contaminant Accumulation of Insulator Surface (애자표면의 오손물 누적에 관한 메커니즘 연구)

  • Park, Jae-Jun
    • The Journal of Information Technology
    • /
    • v.8 no.2
    • /
    • pp.85-91
    • /
    • 2005
  • We studied a pollution mechanism for simulation of contamination environment in industrial concentrated area of around a metropolitan that made to circulated flow in the chamber. In case of the virgin both side of EPDM or Silicon insulator, we confirmed that the pollution to much more than service insulator in the field. Also contamination of initial state of the virgin didn't falling in spite of physical outside factor easily. This study confirmed to that the silicon was too much accumulated pollution contrast to EPDM insulator from scatter(spray) point to regular interval position use the Kaolin contaminant in the chamber. There are effected to the hydrophobicity of polymer insulator due to the pollution. In ceramic insulator, we get to know that pollution is much more at the Post insulator with vertical than with horizontal setup insulator.

  • PDF

User industry and accumulation of technological capabilities of producers-Finnings from the Korean machine tool industry

  • 임채성
    • Proceedings of the Technology Innovation Conference
    • /
    • 2001.06a
    • /
    • pp.71-95
    • /
    • 2001
  • This study reveals that the user industry has a limited role as a source of technological capability in the case of the machine tools in Korea where the user industry is relatively mope advanced than other capital goods industry. The study examined the sources of technological capability in terms of migration of workforce and flow of product design information. Although the capital goods sector is generally regarded as being the sector where the user producer interaction is important the user industry failed to be the seed-bed of technological capability to develop machines. This study argues that this finding could have implications to the specificity of capital goods in a developing country.

  • PDF

Study on Heat Storage and Transportation System for Recovering Non-using Low-temperature Heat (폐열회수 증대를 위한 열운송 축열 시스템 특성 연구)

  • Oh, Changyong;Im, Hongseop;Kim, Insu
    • New & Renewable Energy
    • /
    • v.10 no.4
    • /
    • pp.29-35
    • /
    • 2014
  • Non-used waste heat has recently been paid special attention due to several global warming regulation and energy cost rising. In this study, therefore, thermal energy storage system which uses a solid type heat media has been investigated about the possibility of heat accumulation and heat release for thermal energy storage system. 35kWh of bench-scale thermal storage system was used to investigate the characteristics of the solid type heat media. From the result, it is shown that a solid type heat media should be divided to supply constant heat to the customers' side. It is also shown the flow direction should be considered to reduce temperature difference between top and bottom sides in the thermal storage system.

A NUMERICAL SIMULATION OF HYDROGEN DIFFUSION FOR THE HYDROGEN LEAKAGE FROM FCV IN UNDERGROUND PARKING LOT (지하주차장 내 수소연료 자동차의 수소 누설로 인한 수소 확산에 대한 수치해석 연구)

  • Choi, J.;Hur, N.;Lee, E.D.;Lee, K.B.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.477-482
    • /
    • 2011
  • In the present study, the diffusion process of hydrogen leaking from a FCV (Fuel Cell Vehicle) in an underground parking lot was analyzed by numerical simulations in order to assess the risk of a leakage accident. The temporal and spatial changes of the hydrogen concentration as well as the flammable region in the parking lot were predicted numerically. The effects of the leakage flow rate and an additional ventilation fan were investigated to evaluate the ventilation performance in the parking lot to relieve the accumulation of the leaked hydrogen gas. The present numerical analysis can provide useful information such as the distribution of the leaked hydrogen concentration for safety of various hydrogen applications.

  • PDF

A Case of Hepatic Hydrothorax (간수흉 1예)

  • Hong, In-Soo;Yang, Hak-Suk;Sung, Ki-Joon;Kim, Myung-Soon
    • The Korean Journal of Nuclear Medicine
    • /
    • v.26 no.2
    • /
    • pp.392-395
    • /
    • 1992
  • Hepatic hydrothorax is defined as the presence, in a cirrhotic patient, of a large pleural effusion in the absence of primary pulmonary or cardiac disease. Pleural effusions occur in 5% to 10% of patients with cirrhosis of the liver. The effusions are usually right-sided, but may be bilateral or left-sided. The precise mechanism of fluid accumulation is not clear. We reported a case of right hepatic hydrothorax occuring in the liver cirrhosis with ascites. Diagnosis was confirmed by the intraperitoneal and intrapleural injection of radioisotope $^{99m}Tc-tin$ colloid that demonstrated the one-way transdiaphragmatic flow of fluid from the peritoneal to pleural cavities.

  • PDF

Biobarrier를 이용한 유기오염물질의 생물학적분해모의를 위한 수치모델개발

  • 왕수균
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2003.04a
    • /
    • pp.137-140
    • /
    • 2003
  • This study presents a mathematical model for simulating the fate and transport of a reactive organic contaminant degraded through cometabolism in dual-porosity soils during the in situ bioaugmentations. To investigate the effect of dual-porosity on transport and biodegradation of organic hydrocarbons, a bimodal approach was incorporated into the model. Modified Monod kinetics and a microcolony concept [Molz et at., 1986〕 were employed to represent the effects of biodegrading microbes on the transport and biodegradation of an organic contaminant. The effect of permeability reduction due to biomass accumulation on the flow field were examined in the simulation of a hypothetical field-scale in situ bioaugmentation. Simulation results indicate that the presence of the immobile region can decrease the bioavailablity of biodegradable contaminants and that the placement of microbes and nutrients injection wells should be considered for an effective in situ bioaugmentation scheme.

  • PDF

FEM Analysis for Optimization of Hot Forging Process of Piston Crown (피스톤크라운의 열간단조공정 최적화를 위한 유한요소해석)

  • Min, K.Y.;Lim, S.J.;Choi, H.J.;Choi, S.O.;Park, Y.B.
    • Transactions of Materials Processing
    • /
    • v.18 no.6
    • /
    • pp.444-447
    • /
    • 2009
  • Piston crown to the hot forge a unified nature of the product has a shape with multi-level step forging process, so if you are not a mechanical professional, this process could lead to a significant loss to the material. Therefore, material technology in minor terms; continue to improve the collection rate that undamaged the product material. The piston crown and the manufacturing products such as marine diesel engines are being forged to reduce costs and to improve mechanical properties. Piston crown molding is a hot forging process that works in large volume forging products. Because of the size of the hard plastic material flow process for improving the design and actual field experience through advanced plastic technology, it is important to interpret the results. Also for many experimental plastic procedures, the accumulation of results is very important.

Quantitative Evaluation of Liver Function with Hepatic Receptor Scintigraphy using Tc-99m Galactosylated Serum Albumin (GSA) (Tc-99m Galactosylated Serum Albumin (GSA)을 이용한 정량적 간수용체 영상술)

  • Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
    • /
    • v.32 no.4
    • /
    • pp.305-313
    • /
    • 1998
  • The reduction in the amount of asialoglycoprotein (ASGP) receptor, which resides exclusively on the plasma membrane of functioning mammalian hepatocytes, as a consequence of hepato-cellular damage has been demonstrated in various pathologic conditions of the liver. Galac-tosylated human serum albumin (GSA) is a newly developed receptor-binding agent, specific for the ASGP receptor. Tc-99m GSA binds quantitatively to liver ASGP receptors and the rate of accumulation in the liver is dependent on hepatic function represented as the amount of receptor, as well as the amount of ligand injected, its affinity to the receptor and the hepatic blood flow. The findings of Tc-99m GSA scintigraphy were reported to reflect the hepatic function of the patients with large hepatic tumors, obstructive jaundice, acute and chronic liver disease. Tc-99m GSA scintigraphy is an easy and reliable test and has the clinical potentials to evaluate the liver function in the patients with hepatic disorders.

  • PDF

FEM Analysis for Optimization of Hot Forging Process of Piston Crown (피스톤크라운의 열간단조공정 최적화를 위한 유한요소해석)

  • Min, K.Y.;Lim, S.J.;Choi, H.J.;Choi, S.O.;Park, Y.B.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.05a
    • /
    • pp.98-101
    • /
    • 2009
  • Piston crown to the hot forge a unified nature of the product has a shape with multi-level step forging process, so if you are not a mechanical process that can be a significant loss is material. Therefore, minor in terms of material technology; continue to improve the collection rate should be. The Piston crown and the manufacturing of products such as marine diesel engines, reducing costs and to improve mechanical properties of the method are being forged. Piston crown molding hot forging process the large volume forging products handling because of the size of the size of the hard plastic material flow process for improving the design and actual field experience through advanced plastic technology, and it is important to interpret the results and for many experimental plastic The accumulation of results is very important.

  • PDF

Temporal Variation of Air Temperature in Ice-Valley at Milyang in Association with Ice Formation

  • Lee, Soon-Hwan;Hwang, Soo-Jin
    • Journal of the Korean earth science society
    • /
    • v.28 no.5
    • /
    • pp.598-602
    • /
    • 2007
  • A long-term in situ observation was carried out in the Ice-valley at Milyang in order to explain the factors and processes associated with the summertime ice formation. The variation of temperature inside Ice-valley in relation with ice formation in summer time was found to depend on precipitation rate in spring and cold air sinking in autumn and winter. The rate of temperature rising tends to correspond to sensible heat release depending on the precipitation amount at the freezing location. The reason of the cold air accumulation in a talus in the Ice-valley is the cold air sinking over the surface of talus due to the occurrence of outside clod air mass and the accumulated cold air from autumn to spring flow outside at the bottom of talus. The out-flowing cold air can result in the ice formation in the hot summer.