Browsing by Author "Chen, Chung-Jen"

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Effects of a porous medium on forced convection of a reciprocating curved channel
(2014-11-01)
Fu, Wu-Shung
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Chen, Chung-Jen
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Lai, Yu-Chih
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Huang, Shang-Hao
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機械工程學系
Enhancement of heat transfer rates of a reciprocating curved channel partially installed by a porous medium is investigated numerically. The distribution of heat transfer rates on the heat surface of the reciprocating curved channel is rather non-uniform that easily causes a thermal damage to destroy the channel. A method of using the porous medium to enhance heat transfer rates of the channel is then developed to solve the thermal damage. The arbitrary Lagrangian-Eulerian method is firstly modified for treating a moving boundary problem of the porous medium. Main parameters of Reynolds numbers, porosities, frequencies and amplitudes are examined. The results show that the enhancements of heat transfer rates of most porous medium situations are achieved. However, heat transfer rates of a few porous medium situations are unexpectedly inferior to those of without porous medium situations. (C) 2014 Elsevier Ltd. All rights reserved.
Enhancement of mixed convection heat transfer in a three-dimensional horizontal channel flow by insertion of a moving block
(2012-01-01)
Fu, Wu-Shung
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Chen, Chung-Jen
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Wang, Yuan-Ying
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Huang, Yun
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機械工程學系
Enhancement of mixed convection heat transfer rate of a heat surface in a three dimensional horizontal channel with insertion of a moving block is studied numerically. Bossinique assumption is not adopted, then methods of Roe scheme, preconditioning, and dual time stepping are needed to solve the governing equations. Contributions of important parameters of Gr/Re-2 and moving block velocity to the heat transfer rate are validated. Due to the consideration of natural convection, under situations of large magnitude of Gr/Re-2 a counter-effect for promotion of heat transfer rate is observed. Oppositely, under situations of small magnitude of Gr/Re-2, the enhancement of heat transfer rate is remarkably achieved. (C) 2011 Elsevier Ltd. All rights reserved.
Experimental investigation for effects of a reciprocating motion on mixed convection of a curved vertical cooling channel with a heat top surface
(2011-11-01)
Fu, Wu-Shung
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Chen, Chung-Jen
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Liu, I-Chou
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Hou, Liang-Ying
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機械工程學系
An experimental work is conducted to investigate effects of a reciprocating motion on mixed convection of a curved vertical cooling channel with a heat top surface, and numerical work is executed simultaneously to validate the experimental results auxiliarily. The experimental apparatus are composed of three main parts of a cooling channel, reciprocating movement and heating control. The working fluid is air and data runs are performed for Reynolds numbers, frequencies, amplitudes and temperature differences. Heat transfer rates are affected by cooling fluid flowing and reciprocating motion mutually. The enhancement of heat transfer rate is definite and the most achievement is about 50% in this work. Comparisons of both experimental and numerical results have good agreements. (C) 2011 Elsevier Ltd. All rights reserved.
Systemic Investigation of Promoter-wide Methylome and Genome Variations in Gout
(2020-07-01)
Tseng, Chia-Chun
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Wong, Man Chun
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Liao, Wei-Ting
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Chen, Chung-Jen
;
Lee, Su-Chen
Current knowledge of gout centers on hyperuricemia. Relatively little is known regarding the pathogenesis of gouty inflammation. To investigate the epigenetic background of gouty inflammation independent of hyperuricemia and its relationship to genetics, 69 gout patients and 1455 non-gout controls were included. Promoter-wide methylation was profiled with EPIC array. Whole-genome sequencing data were included for genetic and methylation quantitative trait loci (meQTL) analyses and causal inference tests. Identified loci were subjected to co-methylation analysis and functional localization with DNase hypersensitivity and histone marks analysis. An expression database was queried to clarify biologic functions of identified loci. A transcription factor dataset was integrated to identify transcription factors coordinating respective expression. In total, seven CpG loci involved in interleukin-1 beta production survived genetic/meQTL analyses, or causal inference tests. None had a significant relationship with various metabolic traits. Additional analysis suggested gouty inflammation, instead of hyperuricemia, provides the link between these CpG sites and gout. Six (PGGT1B, INSIG1, ANGPTL2, JNK1, UBAP1, and RAPTOR) were novel genes in the field of gout. One (CNTN5) was previously associated with gouty inflammation. Transcription factor mapping identified several potential transcription factors implicated in the link between differential methylation, interleukin-1 beta production, and gouty inflammation. In conclusion, this study revealed several novel genes specific to gouty inflammation and provided enhanced insight into the biological basis of gouty inflammation.