Thermoregulatory processes have long been implicated in initiation of human sleep. The purpose of this study was to evaluate the role of heat loss in sleep initiation, under the controlled conditions of a constant-routine protocol modified to permit nocturnal sleep. Heat loss was indirectly measured by means of the distal-to-proximal skin temperature gradient (DPG). A stepwise regression analys...

Thermal diffusivity values of molten germanium and silicon were measured by a laser flash method. Simple but useful sample cell systems were developed to keep the molten germanium and silicon shape uniform for a given thickness. In the present experimental condition, it is necessary to consider the effect of not only the radiative heat loss but also the conductive heat loss at the interface bet...

We establish existence of travelling fronts in thermo-diffusive systems of the KPP type in a shear flow with an arbitrary Lewis number and a positive heat-loss at the boundary. We then prove that the leftover concentration behind the front is positive, and that it is small when the heat-loss is small. On the other hand, when the heat-loss approaches a critical value, the temperature becomes uni...

In this paper a new control method is introduced for the minimization of heat loss in CNC motors. This method is based on an open-architecture of a dynamic control to optimize the input current in order to dissipate the minimal heat loss. An algorithm for the dynamic torque control is given and a simulation is carried out using this algorithm for a two axis CNC cutting system with two-guider ba...

There are heat losses during the cycle of real engine that are neglected in ideal air-standard analysis. In this paper, the effect of heat transfer on the net output work is shown and thermal efficiency of the air-standard Atkinson and the Dual combustion cycles are analyzed. Comparison of performances of the air-standard Atkinson and the Dual combustion cycles with heat transfer considerations...

Heat exchangers are widely used in power engineering and industrial applications, many techniques such as coiled tube, surface tension devices, rough surfaces, extended surfaces have been investigated to enhancethermal performance and to minimize the cost and size of the heat exchanger equipment. One of the most important techniques is tube insert. In general,tube inserts can be classified into...

Pretorius, Thea, Gerald K. Bristow, Alan M. Steinman, and Gordon G. Giesbrecht. Thermal effects of whole head submersion in cold water on nonshivering humans. J Appl Physiol 101: 669–675, 2006. First published April 13, 2006; doi:10.1152/japplphysiol.01241.2005.— This study isolated the effect of whole head submersion in cold water, on surface heat loss and body core cooling, when the confoundi...

Despite smaller physiological variations (circadian changes, ovulatory cycle, exercise, etc.), deep body temperature is relatively stable (depending on species) due to regulatory processes (Fig. 1). Core temperature is one of the components of milieu intérieur, similarly to other components it contributes to the stability of physiological functions. The basic physiological regulation is determi...

This study isolated the effect of whole head submersion in cold water, on surface heat loss and body core cooling, when the confounding effect of shivering heat production was pharmacologically eliminated. Eight healthy male subjects were studied in 17 degrees C water under four conditions: the body was either insulated or uninsulated, with the head either above the water or completely submerse...

INTRODUCTION It is generally agreed that man’s adaptations to the heat are well developed, conversely when naked in the cold his physiological adjustment very poor. It could also be argued that humans are historically tropical as: They rely on physiological adjustment in the heat but behavioral adjustments in the cold. The thermo-neutral ambient temperature for nude humans and the temperature n...