The local time-dependent surface heat transfer coefficients for plate finned-tube heat exchangers are estimated in a three-dimensional inverse heat conduction problem. The inverse algorithm utilizing the Steepest Descent Method (SDM) and a general purpose commercial code CFX4.4 is applied successfully in this study in accordance with the simulated measured temperature distributions on the fin s...

Heat production serves as the standard measurement for the determination of energy expenditure and efficiency in animals. Estimations of metabolic heat production have traditionally focused on gas exchange (oxygen uptake and carbon dioxide production) although direct heat measurements may include an anaerobic component particularly when carbohydrate is oxidized. Stoichiometric interpretations o...

We evaluate Rényi entropy flows from generic quantum heat engines (QHE) to a weakly coupled probe environment kept in thermal equilibrium. We show that the flows are determined not only by heat flow but also by a quantum coherent flow that can be separately measured in experiment apart from the heat flow measurement. The same pertains to Shannon entropy flow. This appeals for a revision of the ...

The natural convection flow phenomena that occur inside an enclosed space are very interesting examples of complex fluid systems that may yield to analytical, empirical and numerical solutions, and many reports have looked into this basic problem. In the present study, heat transfer and fluid flow for natural convection in a horizontal rectangular container with a free surface are investigated ...

We present an improved methodology for a thermal transient method enabling simultaneous measurement of thermal conductivity and specific heat of nanoscale structures with one-dimensional heat flow. The temporal response of a sample to finite duration heat pulse inputs for both short (1 ns) and long (5 ls) pulses is analyzed and exploited to deduce the thermal properties. Excellent agreement has...

The exchange of trace gases such as carbon dioxide or methane between the atmosphere and the ocean plays a key role for the climate system. However, the investigation of air–sea gas exchange rates lacks fast and accurate measurement techniques that can also be used in the field, e.g., onboard a ship on the ocean. A promising way to overcome this deficiency is to use heat as a proxy tracer for g...

This paper presents the heat transfer coefficients measured during HC-290 (Propane) vaporisation inside a brazed plate heat exchanger: the effects of heat flux, saturation temperature (pressure) and outlet conditions are investigated. The heat transfer coefficients show weak sensitivity to saturation temperature (pressure) and great sensitivity to heat flux and outlet conditions. The saturated ...

background : necessity of evaluating heat stress in the workplace, require validation of indices and selection optimal index. the present study aimed to assess the precision and validity of some heat stress indices and select the optimum index for using in heavy work activities in hot and dry climates. methods: it carried out on 184 workers from 40 brick kilns workshops in the city of qom, cent...

Loop thermosyphon is a simple and reliable device providing several times higher heat transfer than convectional coolers used in cooling electronic. The paper deals with the cooling of power electronic component by means of this device. The main object of the paper is design and construction of the device to provide heat removal from the electronic component. Paper describes function principle ...

ten solanum tuberosum cultivars and accessions from 11 wild solanum species were evaluated for their tolerance to salt (200 mm nacl or 100 mm na2so4), drought (35% peg), cold (-4ºc) and heat (37ºc). evaluation was based on electrolyte leakage from de-tached leaves of in vitro plantlets. testing involved a rinsing treatment with three changes of distilled water to remove electrolytes from leaf a...