• Title/Summary/Keyword: wilson

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Measurement and Prediction of Flash Points of Acetic Acid-Formic Acid System using Cleveland Open Cup Apparatus (Cleveland 개방식 장치를 이용한 Acetic acid+Formic acid 계의 인화점 측정과 예측)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Institute of Gas
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    • v.17 no.6
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    • pp.67-72
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    • 2013
  • The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. The flash point is a major physical property used to analyse the fire and explosion hazards of a flammable liquid solution. The flash point data for pure components are easily available in several literature. But the flash points of the flammable binary solutions appear to be scarce in the literature. The objective of this study is to measure and estimate the flash point of acetic acid-formic acid system. Cleveland open cup tester was used to measure the flash point. The experimental data were compared with the values estimated by the Raoult's law and the optimization methods based on van Laar and Wilson equations. As a result, the estmated values by optimization methods were found to be better than those based on the Raoult's law.

The Measurement and Prediction of Flash Point for Binary Mixtures of Methanol, Ethanol, 2-Propanol and 1-Butanol at 101.3 kPa (Methanol, Ethanol, 2-Propanol 그리고 1-Butanol 이성분 혼합계에 대한 101.3 kPa에서의 인화점 측정 및 예측)

  • Oh, In Seok;In, Se Jin
    • Fire Science and Engineering
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    • v.29 no.5
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    • pp.1-6
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    • 2015
  • Flash point is one of the most important variables used to characterize fire and explosion hazard of liquids. The lower flash point data were measured for the binary systems {methanol + 1-butanol}, {ethanol + 1-butanol} and {2-propanol + 1-butanol} at 101.3 kPa. Experiments were performed according to the standard test method (ASTM D 3278) using a SETA closed cup flash point tester. The measured flash points were compared with the predicted values calculated using the following activity coefficient models: Wilson, Non-Random Two Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC). The measured FP data agreed well with the predicted values of Raoult's law, Wilson, NRTL and UNIQUAC models. The average absolute deviation between the predicted and measured lower FP was less than 1.14 K.

Wilson's Disease in Bangladeshi Children: Analysis of 100 Cases

  • Rukunuzzaman, Md.
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.18 no.2
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    • pp.121-127
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    • 2015
  • Purpose: To evaluate clinical and laboratory profile of Wilson's disease (WD) in children. Methods: This cross sectional study was conducted at Bangabandhu Sheikh Mujib Medical University Hospital. Bangladesh, over a period of 3 years. One hundred consecutive children of WD between 3 to 18 years of age were evaluated. Results: Mean age was $8.5{\pm}1.5years$. Male female ratio was 2:1. Ninety-one percent of patients were Muslim and 9% Hindu. A total of 53% cases of hepatic WD presented between 5 to 10 years of age and most of the neurologic WD manifested in 10-15 years age group. Sixty-nine children presented only with hepatic manifestations, 6 only with neurological manifestations, 14 with both hepatic and neurological manifestation, 10 children was asymptomatic and 1 patient presented with psychiatric features. WD presented as chronic liver disease (CLD) in 42%, CLD with portal hypertension in 34%, acute hepatitis in 20% and fulminant hepatic failure in 4% cases. Stigmata of CLD were found in 18% patients. Keiser-Fleischser ring was found in 76% total patients. Elevated serum transaminase was found in 85% cases, prolonged prothrombin time in 59% cases and hypoalbuminaemia in 53% cases. A total of 73% patients had low serum ceruloplasmin, basal urinary copper of >$100{\mu}g/day$ was found in 81% cases and urinary copper following penicillamine challenge of >$1,200{\mu}g/day$ was found in 92% cases. Conclusion: Majority of studied WD children presented with hepatic manifestation of which 76% presented with CLD. Any child presented with jaundice after the age of 3 years should be investigated for WD.

The Measurement of Lower Flash Point for tert-Pentanol+n-Decane System Using Tag Open-Cup Tester (Tag 개방식 장치를 이용한 tert-Pentanol+n-Decane 계의 하부인화점 측정)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Institute of Gas
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    • v.16 no.5
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    • pp.41-46
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    • 2012
  • The flash point the lowest temperature at which the concentration of vapor of the substance in the air reaches the lower flammability limit(LFL), and is one of the most important physical properties used to determine the potential for fire and explosion hazards of industrial materials. The most published flash point data was for pure components and the flash points of the binary solutions that have flammable components, appear to be scarce in the literature. In the present study, the flash points of tert-pentanol+n-decane system were measured by Tag open-cup tester. The measured data were compared with the values calculated by the Raoult's law and the optimization methods based on the Wilson and NRTL equations. The calculated values by optimization methods were found to be better than those based on the Raoult's law.

The Farnesyl Protein Transferase Inhibition Activity of Chalcone Derivatives (Chalcone 유도체의 Farnesyl Protein Transferase 저해활성)

  • Yu, Seong-Jae;Myung, Pyung-Keun;Kwon, Byung-Mok;Lee, Seung-Ho;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.42 no.3
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    • pp.252-255
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    • 1999
  • Inhibition activities$(pI_{50})$ of chalcone derivatives as substrate with farnesyl protein transferase(FPTase) were determined in vitro. The structure activity relationships(SAR) between the activity and physicochemical parameters of X & Y-substituents on the phenyl groups were analyzed by Free-Wilson and Hansch method. X-substituents on the benzoyl group have the more important role to inhibition activity than Y-substituents on the styryl group. Among them, none substituent, 8 showed the highest FPTase inhibition activity$(pI_{50}=4.30)$. Particularly, the SAR equation could be formulated, showing a parabolic relationship between the activity and hydrophobicity(logP) where the optimal value$({\Sigma}logP)_{opt}$ was 3.915. And also the activity depends on the steric effect(Es > 0) with X-substituent and the resonance effect(R < 0) with electron donating Y-substituents. Based on the results of SAR analyses, the interactions between substrates and receptor, FPTase, could be assumed.

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Flow Boiling Heat Transfer Characteristics of R22 Alternative Refrigerants in a Horizontal Smooth Tube (R22 대체냉매의 수평원관내 흐름비등 열전달 특성)

  • 한재웅;김신종;정동수;김영일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.4
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    • pp.242-251
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    • 2001
  • Flow boiling heat transfer coefficients (HTCs) of R22, R134a, R407C, and R410A were measured for a horizontal plain tube. The test section was made of a copper tube of 8.8mm inner diameter and 1000mm length respectively. The refrigerant was heated by passing hot water through an annulus surrounding the test section. All tests were performed at a fixed refrigerant saturation temperature of $5^{\circ}C$ with mass fluxes of 100~300 kg/$m^2$,/TEX>s. HTCs were measured by two methods: the direct wall temperature measurement method and the indirect Wilson plot method. Experimental results showed that the Wilson plot method was affected greatly by the external test conditions and yielded inconsistent results. For the mass flux of 100kg/$m^2$,/TEX>s, HTCs were almost constant regardless of the quality for a given refrigerant HTCs of R134a and R407C were similar to those of R22 while those of R410A were 60% higher than those of R22. For the mass fluxes of 200 and 300kg/$m^2$,/TEX>s, HTCs of R407C were almost the same as those of R22, while HTCs of R134a and R410A were 12-13% and 20~23% higher than those of R22 respectively. For pure refrigerant, Shah\`s correlation yielded a good agreement with the measured data both qualitatively and quantitatively.

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