Visual Study on Flow and Operational Characteristics of Flat Plate Closed Loop Pulsating Heat Pipes

This paper presents an experimental study including visualization on a flat plate closed loop pulsating heat pipes.It consists of a total of 40 channels with square cross section(2 mm×2 mm,165 mm long) machined directly on an aluminum plate(180 mm×120 mm×3 mm) covered by a transparent plate.The working fluid employed is ethanol.As a result,various flow patterns and their transitions are observed and found to be related to the fluid fill ratio,input heat load and the device orientation.Also the operational c...     

Regional variation in copper content of arterial wall

Résumé La teneur en cuivre dans l'aorte et les artères pulmonaire, rénale, illiaque et carotide a été déterminée. Une corrélation inverse entre le degré d'athérosclérose et celui du cuivre a été observée. La cause de ce phénomène reste à ètre établie.     

Ultrastructural changes in rat liver cells after intramuscular implantation of a Walker tumor

Résumé L'implantation i.m. de la tumeur de Walker chez les rats provoque une dilatation, une désorganisation et une dégranulation progressives du réticulum endoplasmique granuleux des hépatocytes. Ces changements, qui s'accompagnent en même temps d'une prolifération du réticulum endoplasmique lisse, représenteraient les manifestations ultrastructurales d'une insuffisance microsomale démontrée biochimiquement dans le foie des rats affectés par la tumeur de Walker.

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This work was supported in part by the Ministère des Affaires Sociales, Québec, the Medical Research Council of Canada (Block Term Grant No. MT-1829), the Cancer Research Society Inc., and was undertaken as a special project of the Council for Tobacco Research, USA, and the Canadian Tobacco Industry.     

Two-Phase Flow Modeling in a Single Closed Loop Pulsating Heat Pipes

Mathematical modeling of pulsating heat pipes through 'first’ principles is a contemporary problem which remains quite elusive. Simplifications and assumptions made in all the modeling approaches developed so far render them unsuitable for engineering design. In this paper, a more realistic modeling scheme is presented which provides considerable try for thought toward the next progressive step. At high enough heat flux level, closed loop pulsating heat pipes experience a bulk internal unidirectional fluid circulation. Under such a condition, conventional two-phaseflow modeling in capillary tubes may be applied. This has been attempted for single-loop PHPs. A homogeneous model and a separated two-fluid flow model based on simultaneous conservation of mass, momentum and energy, have been developed for an equivalent 'open flow' system. The model allows prediction of two-phase flow parameters in each subsection of the device thereby providing important insights into its operation. The concept of 'void fraction constraint'in pulsating heat pipe operation is introduced and its relevance to future modeling attempts is outlined.