• Title/Summary/Keyword: Barrier free

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Vapor Bubble Nucleation : A Microscopic Phenomenon

  • Kwak, Ho-Young
    • Journal of Mechanical Science and Technology
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    • v.18 no.8
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    • pp.1271-1287
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    • 2004
  • In this article, vapor bubble nucleation in liquid and the evaporation process of a liquid droplet at its superheat limit were discussed from the viewpoint of molecular clustering (molecular cluster model for bubble nucleation). For the vapor bubble formation, the energy barrier against bubble nucleation was estimated by the molecular interaction due to the London dispersion force. Bubble nucleation by quantum tunneling in liquid helium under negative pressure near the absolute zero temperature and bubble nucleation on cavity free micro heaters were also presented as the homogenous nucleation processes.

A study of fabricating catalyst free copper plating layer using electroless copper plating solution (무전해 구리 도금액을 이용한 무촉매 구리 도금층 형성에 관한 연구)

  • Heo, Jin-Yeong;Lee, Hong-Gi;Im, Yeong-Saeng
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2013.05a
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    • pp.133-134
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    • 2013
  • 본 연구는 비전도성 소재 상에 무전해 동도금(Electroless Copper)시 수행되는 씨앗층이나 촉매공정 없이 직접 구리 석출물을 얻는 방법 중 하나에 관한 연구이다. 실리콘 웨이퍼상에 확산방지를 위한 Ta 금속확산방지(Metal barrier)막층 형성 후 무전해 동도금에 침지 후 최소한의 전류를 인가한 결과 균일한 구리피막을 얻을 수 있었으며, 표면 및 단면 조직 분석결과 이를 확인할 수 있었다.

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The comparison of blood-brain barrier permeability of free radical scavengers, PBN and its derivatives in rat

  • Lee, Na-Young;Kang, Young-Sook
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.92-92
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    • 2001
  • ICAP법을 이용하였을 때 뇌내 약물량은 SS20-0098은 PBN보다 4.5배 큰 값을 나타내었고 정맥투여 후 2시간에서의 뇌내 약물량은 SS20-0098과 PBN이 거의 유사한 값을 나타내었다. PBN과 SS20-0098은 octanol partition 계수(log P)가 각각 1.23, 2.26로 지용성인 큰 SS20-0098이 혈액 내에서 대사를 저지시키는 방법으로 투여되었을 때는 비교적 더 많은 양이 뇌로 이행되고 있음을 알 수 있었다.

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매립지 침출수의 효과적인 제거를 위한 반응성 차수재 개발

  • 이현주;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.395-398
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    • 2003
  • Geosynthetic Clay Liners(GCLs) have been widely used as hydraulic barrier in landfills and remediation projects of contaminated sites. The aim of this research is to modify GCLs for effective removal of contaminants. We perform the free swell test, hydraulic conductivity test, and contaminants (TCE, hexavalent chromium, and nitrate) removal test on the bentonite-ZVI mixture with various ZVI content. As the ZVI content increased, contaminants removal efficiencies and swell volume increased, and hydraulic conductivity decreased.

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Changes in Free Oscillation Mode in Isahaya Bay Due to a Barrier

  • Park, Byung-Ho;Yuk, Jin-Hee
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.259-269
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    • 2003
  • The necessary of predicting changes in tidal regime that would caused by large coastal engineering developments has been led to increased numerical modeling of tides on the continental shelf since 1970s (Flather, 1976; Choi, 1978; Greenberg, 1979). (omitted)

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A Study on Design Guide-lines for the Handicapped People (장애인 편의시설 설계지침 개발에 관한 연구)

  • Kang, Byoung-Keun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.6 no.11
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    • pp.7-16
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    • 2000
  • This study shows the 'design guide-line' for the handicapped people who uses certain buildings or facilities, for Barrier Free. It has the object that they are able to utilize the facilities in the variable buildings basically and to approach to informations without difficulties. So, it can be used as 'design guide-line' for the handicapped people through several architectural criterions.

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Synthesis of Selenoflavonoids

  • Kim, Dong-Myung;Jeong, Jin-Hyun
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.182.1-182.1
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    • 2003
  • Flavonoids with oxygen atoms are known to have potent biological effect.They have been studied long as major antioxidants which protect cell membranes. Recent medical surveys show that increased intake of selenium decreases the risk of breast, colon, lung and prostrate cancer by preventing free radical generation. The flavonoids, isoflavonoids, and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through BBB(Brain Blood Barrier)The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. (omitted)

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Dynamics of Pore Growth in Membranes and Membrane Stability

  • W. Sung;Park, P. J.
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.15-15
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    • 1998
  • Pores can form and grow in biomembranes because of factors such as thermal fluctuation, transmembrane electrical potential, and cellular environment. We propose a new statistical physics model of the pore growth treated as a non-Markovian stochastic process, with a free energy barrier and memory friction from the membrane matrix treated as a quasi-two-dimensional viscoelastic and dielectric fluid continuum.(omitted)

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The Height of Fall as a Predictor of Fatality of Fall (추락 후 사망 예측인자로서의 추락 높이)

  • Suh, Joo Hyun;Eo, Eun Kyung;Jung, Koo Young
    • Journal of Trauma and Injury
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    • v.18 no.2
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    • pp.101-106
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    • 2005
  • Purpose: The number of the deceased from free-fall is increasing nowadays. Free-fall comes to a great social problem in that even the survivor will be suffering for cord injury or brain injury, and so on. We analyzed the cases of free-fall patients to find out whether the injury severity is mainly correlated with the height of fall. Methods: We retrospectively investigated the characteristics of patients, who fall from the height above 2m from January 2000 to August 2004. We excluded the patients who transferred to other hospital, transferred from other hospital, and not known the height of fall. 145 patients were evaluated. Variables included in data analysis were age, height of fall, injury severity score (ISS), the being of barrier, and the survival or not. To find out the correlation between height of fall and death, we used receive operating characteristics (ROC) curve analysis. Results: The mean age of patients was $36.5{\pm}19.4$ years old. 110 were male and 35 were female. Mean height of fall was $11.1{\pm}8.5m$. 51 patients (35.2%) were died and 30 patients of them (58.9%) got emergency room on dead body. The mean height of fall is $8.9{\pm}5.8m$ for 94 survivors and $15.2{\pm}11.0m$ for the 51 deceased (p<0.001). The area under the ROC curve was 0.646, which means the height of fall was not adequate factor for predicting for death. At 13.5m, as cut?off value, sensitivity is 52.9%, specificity is 86.2%, positive predictive value is 67.5% and negative predictive value is 77.1%. There were statistical differences in mortality rate and ISS between 'below 13.5m group' and 'above 13.5m group', but there was not statistical difference in head and neck AIS. Conclusion: The height of fall is not adequate factor for prediction of death. So other factors like intoxication or not, the being of barrier or protection device need to be evaluated for predicting of free-fall patient's death.