• Title/Summary/Keyword: heat sensitivity

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Design Sensitivity Analysis and Topology Optimization of Thermal Systems Considering Convection Heat Transfer (대류를 고려한 열전달 시스템의 민감도 해석 및 위상 최적 설계)

  • Moon, Hee-Gon;Wang, Se-Myung;Shim, Ho-Kyung
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1053-1057
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    • 2004
  • This paper presents the adjoint variable design sensitivity analysis for thermal systems considering both conduction and convection heat transfer. Both nodal temperature and total heat flow are considered to be objective functions and design sensitivity formulas are derived for each case. For the case of convection heat transfer, the adjoint analysis is carefully proceeded to obtain a precise result. A topology optimization example is examined for a simple planar square plate in order to design a heat exchanger as verification.

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A Study on Calibration of Heat Flux Sensor by using Convective Heat Transfer (대류방식을 이용한 열유속센서의 검정에 관한 연구)

  • Yang, Hoon-Cheul;Song, Chul-Hwa;Kim, Moo-Hwan
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1358-1363
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    • 2004
  • The objective of this work is to propose calibration facility in which a thin film type heat flux sensor can be calibrated under convective flow condition by using a small wind tunnel with the constant temperature plate condition. A small wind tunnel has been built to produce a boundary layer shear flow above a constant temperature copper plate. 12-independent copper blocks, thin film heaters, insulators and temperature controllers were used to keep the temperature of flat plate constant at a specified temperature. Three commercial thin film-type heat flux sensors were tested. Convective calibrations of these gages were performed over the available heat flux range of $1.4{\sim}2.5kW/m^2$. The uncertainty in the heat flux measurements in the convective-type heat flux calibration facility was ${\pm}2.07%$. Non-dimensional sensitivity is proposed to compare the sensitivity calibrated by manufacturer and that of experiment conducted in this study.

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Topology Design Optimization of Heat Conduction Problems using Adjoint Sensitivity Analysis Method

  • Kim, Min-Geun;Kim, Jae-Hyun;Cho, Seon-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.6
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    • pp.683-691
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    • 2010
  • In this paper, using an adjoint variable method, we develop a design sensitivity analysis(DSA) method applicable to heat conduction problems in steady state. Also, a topology design optimization method is developed using the developed DSA method. Design sensitivity expressions with respect to the thermal conductivity are derived. Since the already factorized system matrix is utilized to obtain the adjoint solution, the cost for the sensitivity computation is trivial. For the topology design optimization, the design variables are parameterized into normalized bulk material densities. The objective function and constraint are the thermal compliance of structures and allowable material volume respectively. Through several numerical examples, the developed DSA method is verified to yield very accurate sensitivity results compared with finite difference ones, requiring less than 0.25% of CPU time for the finite differencing. Also, the topology optimization yields physical meaningful results.

Functional roles of glutamic acid E143 and E705 residues in the N-terminus and transmembrane domain 7 of Anoctamin 1 in calcium and noxious heat sensing

  • Choi, Jonghyun;Jang, Yongwoo;Kim, Haedong;Wee, Jungwon;Cho, Sinyoung;Son, Woo Sung;Kim, Sung Min;Yang, Young Duk
    • BMB Reports
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    • v.51 no.5
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    • pp.236-241
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    • 2018
  • Anoctamin 1 (ANO1) is an anion channel that is activated by changes in cytosolic $Ca^{2+}$ concentration and noxious heat. Although the critical roles of ANO1 have been elucidated in various cell types, the control of its gating mechanisms by $Ca^{2+}$ and heat remain more elusive. To investigate critical amino acid residues for modulation of $Ca^{2+}$ and heat sensing, we constructed a randomized mutant library for ANO1. Among 695 random mutants, reduced $Ca^{2+}$ sensitivity was observed in two mutants (mutant 84 and 87). Consequently, the E143A mutant showed reduced sensitivity to $Ca^{2+}$ but not to high temperatures, whereas the E705V mutant exhibited reduced sensitivity to both $Ca^{2+}$ and noxious heat. These results suggest that the glutamic acids (E) at 143 and 705 residues in ANO1 are critical for modulation of $Ca^{2+}$ and/or heat responses. Furthermore, these findings help to provide a better understanding of the $Ca^{2+}$-mediated activation and heat-sensing mechanism of ANO1.

Sensitivity Analysis on Design Factor of Ground Heat Exchanger for Optimum Design of Vertical Ground Source Heat Pump System (수직밀폐형 지중열교환기의 최적설계를 위한 설계인자 영향도 분석)

  • Bae, Sangmu;Kim, Hongkyo;Nam, Yujin
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.3
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    • pp.87-93
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    • 2018
  • Ground source heat pump(GSHP) system is one of the high efficiency heat source systems which utilizes the constant geothermal energy of a underground water or soil. However, the design of conventional GSHP system in the domestic market is dependent on the experience of the designer and the installer, and it causes increase of initial installation cost or degradation of system performance. Therefore, it is necessary to develop a guideline and the optimal design method to maintain stable performance of the system and reduce installation cost. In this study, in order to optimize the GSHP system, design factors according to ground heat exchanger(GHX) type have been examine by simulation tool. Furthermore, the design factors and the correlation of a single U-tube and a double U-tube were analyzed quantitatively through sensitivity analysis. Results indicated that, the length of the ground heat exchanger was greatly influenced by grout thermal conductivity for single U-tube and pipe spacing for double U-tube.

Heat-Shocked Drosophila Kc Cells Have Differential Sensitivity to Translation Inhibitors

  • Han, Ching-Tack
    • BMB Reports
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    • v.30 no.1
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    • pp.55-59
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    • 1997
  • The heat shock response is a universal stress response observed in all organisms and cultured cells. The response is regulated at both the transcriptional and translational level. Heat shocked Drosophila melanogaster Kc cells are used as the system for the study of translational regulation. In this system non-heat shock messages are associated with polysome but are not translated in a heat shocked condition. To figure out the change in the translation machinery. the effects of translation elongation inhibitors were tested on Kc cells. The result showed that the sensitivity of translation to these drugs changed in heat shocked cells. The significant changes were the decreased inhibition of heat shock protein synthesis by cycloheximide, emetine. and puromycin. and the increased inhibition of heat shock protein synthesis by verrucarin A. implying that the translation elongation mechanism in heat shocked cells changed.

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Studies on Heat Sensitivity of Egg Albumen II. Effects of pH and/or the Addition of Metal ions on Heat Sensitivity of Egg Albumen (난백의 숙감수성에 관한 연구 II. 금속염의 첨가와 pH가 난백의 열감수성에 미치는 영향)

  • 유익종;이성기;김영붕
    • Korean Journal of Poultry Science
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    • v.16 no.1
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    • pp.17-22
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    • 1989
  • In order to dull heat sensitivity of egg albumen, metal ions (aluminium, ferric, ferrous, copper) were added and functional properties or egg albumen were determined before and after heat treatment at $60^{\circ}C$ for 5 minutes. Effect of pH on heat sensitivity of aluminium salt added egg albumen was also determined. Addition of metal ions increased turbidity of egg albumen before and after the heat treatment. Changes of the turbidity were minimized by addition of aluminium salt. The foaming power was markedly increased by addition of ferric salt before the heat treatment and increased by addition of aluminium, ferric and copper salt after the heat treatment. Before the heat treatment the foam was stable by addition of ferric and ferrous salt but after the heat treatment it was stable by addition of aluminium and ferric salt. The turbidity and foaming property of the egg albumen with aluminium salt were not largely changed after the heat treatment at pH range 7 to 8.5. Over pH 9 the turbidity and foaming power were not decreased, but the foam stability was increased before and after the heat treatment. Salmonella typhimurium ATCC 14028 (10$^{6}$ cells/$m\ell$) inoculated in egg albumen at pH range 7 to 8.5 was destructed by the heat treatment.

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A Sensitivity Analysis of Design Factors of Air-Conditioning System with Slab Thermal Storage (슬래브축열 시스템 설계인자의 감도해석)

  • Jung, Jae-Hoon
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.590-595
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    • 2008
  • In this paper, the sensitivity analysis was examined about the main factors that compose an air-conditioning system with slab thermal storage by using the analytic solution. Those factors are the insulation performance of floor slab surface, the slab thickness, the heat capacity of floor slab, the air change rate, and the insulation performance of the wall. The slab thickness and heat capacity of floor slab that minimize heating loads was gained by sensitivity analysis. It is became clear that the insulation performance of slab surface, high airtightness and high heat insulation are important design factors in air conditioning system with slab thermal storage.

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Studies on Heat Sensitivity of Egg Albumen I. Effects of Heating Time and Temperature, pH and NaCl Concentration on Heat Sensitivity of Egg Albumen (난백 의 열감수성 에 관한 연구 I. 가열온도와 시간, pH 및 NaCl농도가 난백의 열감수성에 미치는 영향)

  • 유익종
    • Korean Journal of Poultry Science
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    • v.15 no.1
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    • pp.39-44
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    • 1988
  • This study was undertaken to find out the effect of heating time and temperature, pH and NaCl concentration on heat sensitivity of egg albumen during heat treatment. Sharp increase of the turbidity and rapid decrease of the foaming power were observed when egg albumen was heated at above $60^{\circ}C$. Egg albumen became opaque when it was heated at $60^{\circ}C$ for above 13 minutes or at $65^{\circ}C$ for above 5 minutes. The turbidity was markedly increased at below pH 7 and the foaming power was largely decreased at around pH 4.0 by the heat treatment ($60^{\circ}C$, 5 min). The foam stability was slightly decreased at alkaline pH range by the heat treatment (60t, 5 min). The addition of NaCl up to 0.3M decreased the turbidity. There was no effect of NaCl addition on the foaming power, but the foam stability was decreased by the addition of NaCl at above 0.2M before and after the heat treatment ($60^{\circ}C$, 5 min).

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