The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Sam Fong Yau Li - One of the best experts on this subject based on the ideXlab platform.
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supercritical fluid extraction and chromatography of steroids with Freon 22
Journal of Chromatography A, 1990Co-Authors: Sam Fong Yau LiAbstract:Abstract The use of Freon-22 in supercritical fluid extraction and chromatography was investigated. For the extraction of steroids, the extraction efficiency with supercritical Freon-22 was found to be significantly better than that with supercritical carbon dioxide and the extraction time required was much shorter. Preliminary results for the chromatographic analysis of steroids also indicated that polar compounds could be eluted much more easily with Freon-22 than carbon dioxide as the mobile phase.
Shyam Sunder - One of the best experts on this subject based on the ideXlab platform.
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development of mixture composition maldistribution in a distillation column with structured packing
Theoretical Foundations of Chemical Engineering, 2010Co-Authors: Aleksandr N. Pavlenko, Shyam Sunder, Yu V Chekhovich, N. I. Pecherkin, V. E. Zhukov, Patrick Alan HoughtonAbstract:The distribution of the composition of a mixture of Freons R-114 and R-21 over the cross section of a distillation column filled with structured packing is experimentally studied. Results on the efficiency of Freon mixture separation, the pressure drop in the packing, and the distribution of the local concentration of the low-boiling component throughout the cross section and height of the structured packing are presented. The vapor phase load factor was varied over a wide range up to hydraulic flooding. According to the experimental results, the large-scale maldistribution of the mixture composition occurs inside the packing over the column cross section, even though the overall separation performance of the column is excellent. Maldistribution is observed throughout the total height of the column. The location of the large zones of maldistribution significantly depends on the liquid and vapor flow rates.
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Experimental study of the effect of maldistribution at the structured packing inlet on the Freon mixture separation efficiency
Theoretical Foundations of Chemical Engineering, 2009Co-Authors: Aleksandr N. Pavlenko, N. I. Pecherkin, Vladimir Chekhovich, V. E. Zhukov, Shyam SunderAbstract:The results of an experimental study of the effect of the initial maldistribution over a structured packing on the separation efficiency of a binary Freon mixture are considered. The study was performed in a distillation column 0.9 m in diameter on a mixture of R114 and R21 Freons. The results on the efficiency of Freon mixture separation, the pressure drop on the packing, and the distribution of the local liquid flow rate under the packing are presented. The experimental results showed that the rotation angle of structured packed layers have a significant effect on the efficiency of mixture separation in the case of maldistribution.
Aleksandr N. Pavlenko - One of the best experts on this subject based on the ideXlab platform.
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development of mixture composition maldistribution in a distillation column with structured packing
Theoretical Foundations of Chemical Engineering, 2010Co-Authors: Aleksandr N. Pavlenko, Shyam Sunder, Yu V Chekhovich, N. I. Pecherkin, V. E. Zhukov, Patrick Alan HoughtonAbstract:The distribution of the composition of a mixture of Freons R-114 and R-21 over the cross section of a distillation column filled with structured packing is experimentally studied. Results on the efficiency of Freon mixture separation, the pressure drop in the packing, and the distribution of the local concentration of the low-boiling component throughout the cross section and height of the structured packing are presented. The vapor phase load factor was varied over a wide range up to hydraulic flooding. According to the experimental results, the large-scale maldistribution of the mixture composition occurs inside the packing over the column cross section, even though the overall separation performance of the column is excellent. Maldistribution is observed throughout the total height of the column. The location of the large zones of maldistribution significantly depends on the liquid and vapor flow rates.
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Experimental study of the effect of maldistribution at the structured packing inlet on the Freon mixture separation efficiency
Theoretical Foundations of Chemical Engineering, 2009Co-Authors: Aleksandr N. Pavlenko, N. I. Pecherkin, Vladimir Chekhovich, V. E. Zhukov, Shyam SunderAbstract:The results of an experimental study of the effect of the initial maldistribution over a structured packing on the separation efficiency of a binary Freon mixture are considered. The study was performed in a distillation column 0.9 m in diameter on a mixture of R114 and R21 Freons. The results on the efficiency of Freon mixture separation, the pressure drop on the packing, and the distribution of the local liquid flow rate under the packing are presented. The experimental results showed that the rotation angle of structured packed layers have a significant effect on the efficiency of mixture separation in the case of maldistribution.
Pengyuan Yang - One of the best experts on this subject based on the ideXlab platform.
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Zeolite-modified microcantilever gas sensor for indoor air quality control
Sensors and Actuators B: Chemical, 2003Co-Authors: Jia Zhou, Po Li, Yingcai Long, Song Zhang, Yiping Huang, Pengyuan Yang, Feng Zhou, Minhang BaoAbstract:To control indoor air quality, a novel Freon gas sensor of piezoelectric microcantilever coated with zeolite has been developed in this paper. Excited by an ac voltage, the microcantilever is employed to detect the concentration of sample Freon-12 gas ranged from 0 to 100ppm by the effect of the specific MFI zeolite modification. High selectivity and sensitivity combined with excellent repeatable and reversible performances are shown. The relationship between the frequency shift in percent and the concentration of Freon gas is linear. The minimum mass changing of 3.5 × 10-9g and the sensitivity of -0.0024%/ppm are determined from the experimental results. © 2003 Elsevier Science B.V. All rights reserved.
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Quantitative determination of Freon gas using an electronic nose
Analyst, 2002Co-Authors: Liangyi Zhang, Feng Zhou, Yu Lu, Pengyuan YangAbstract:This paper reports a quantitative electronic nose (enose) for the quantitative determination of Freon gas within the concentration range 0–1000 ppm in the presence of interfering gases such as water, lubricant and petrol vapours. This quantitative enose is a new type of Freon detection system, composed of an array of four sensors. The artificial neural network (ANN) and fuzzy logic type of ANN (FNN), in combination with the relative error concept in analytical chemistry, are integrated for both quantification and discrimination. The predicted results are satisfied with a pass rate of >80% within the permitted relative errors. The results show that the Freon enose developed in this study is reliable for both the qualitative and quantitative determination of Freon gas and exhibits the merits of high sensitivity, anti-interference and accuracy.
E G Danilenko - One of the best experts on this subject based on the ideXlab platform.
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coexistence curve scaling equations of the alternative refrigerant hfc 125 and refrigerant f 113 near the critical point
Journal of Molecular Liquids, 2001Co-Authors: E T Shimanskaya, E G DanilenkoAbstract:Abstract The statistical analysis of experimental data presented in paper [1] for alternative Freon HFC-125 and in [2] for Freon F-113 is carried out using the technique [3,4]. For both substances the effective values of temperature dependencies of exponents and amplitudes of the leading terms of symmetric and asymmetric parts of the coexistence curve are investigated. The limiting values of the exponent β o and of the diameter singularity exponent β 1 are determined. It is shown that the alternative Freon HFC-125 and Freon F-113 behave similarly near the critical point.