Animal life requires hard work but the ability to endure such workload appears be limited. Heat dissipation limit (HDL) hypothesis proposes that capacity dissipate excess of body heat during may sustained energy use. Experimental facilitations loss rate via feather-clipping in free-living birds seem support HDL testing through laboratory experiments under controlled conditions is not reported. ...

Overheating is one of the main factors limiting physical activity. During running, thermoregulatory metabolism, which keeps core temperature steady at rest, is adjusted through a body temperature independent mechanism to compensate for the exertional heat generation. The colder the environment, the higher the metabolism at rest, and the more complete the compensation is. As a marathoner, one of...

Wearable computers and PDA’s are physically close to, or are in contact with, the user during most of the day. This proximity would seemingly limit the amount of heat such a device may generate, conflicting with user demands for increasing processor speeds and wireless capabilities. However, this paper explores significantly increasing the heat dissipation capability per unit surface area of a ...

Several techniques and metrics based on the Second Law of Thermodynamics have been used in the past for the analysis of heat exchangers. The terms used for these techniques include irreversibility analysis, entropy generation minimization, exergy analysis and thermodynamic efficiency. Entransy is a recently developed concept reflecting the heat transfer potential, rather than the ability to con...

The entropy generation analysis of fully turbulent convective heat transfer to nanofluids in a circular tube is investigated numerically using the Reynolds Averaged Navier–Stokes (RANS) model. The nanofluids with particle concentration of 0%, 1%, 2%, 4% and 6% are treated as single phases of effective properties. The uniform heat flux is enforced at the tube wall. To confirm the validity of the...

A method is described for measuring the heat and water vapor dissipation characteristics of wheelchair cushions and seating systems while under simulated loading conditions. Thermal interaction between the body and seating surfaces can result in elevated tissue temperature and moisture build-up, which may increase the risk of pressure ulcers associated with prolonged ischemia or due to macerati...

To overcome the imbalance between spindle heat generation and dissipation caused 11 by existed spindle cooling strategies, this paper develops a power matching based cooling 12 strategy for motorized spindle unit. Firstly, heat generation, conduction and dissipation are 13 considered for the modeling of spindle structural heat exchange. This modeling methodology 14 conveys that an operating mot...

At high temperature (greater than 40°C) endotherms experience reduced passive heat dissipation (radiation, conduction and convection) and increased reliance on evaporative heat loss. High temperatures challenge flying birds due to heat produced by wing muscles. Hummingbirds depend on flight for foraging, yet inhabit hot regions. We used infrared thermography to explore how lower passive heat di...