Mold heat conductance as drive force for tuning freeze-casted nanocellulose foams microarchitecture

2018 ◽  
Vol 225 ◽  
pp. 167-170 ◽  
Author(s):  
Marcos Mariano ◽  
Juliana da Silva Bernardes ◽  
Mathias Strauss
Keyword(s):  
Heat Conductance ◽  
Drive Force

Skinfolds and resting heat loss in cold air and water: temperature equivalence

1975 ◽  
Vol 39 (1) ◽  
pp. 93-102 ◽  
Author(s):  
R. M. Smith ◽  
J. M. Hanna
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Heat Loss ◽  
Air Temperature ◽  
Indirect Calorimetry ◽  
Cold Water ◽  
Heat Conductance ◽  
Air Temperatures ◽  
Body Core ◽  
Male Subjects

Fourteen male subjects with unweighted mean skinfolds (MSF) of 10.23 mm underwent several 3-h exposures to cold water and air of similar velocities in order to compare by indirect calorimetry the rate of heat loss in water and air. Measurements of heat loss (excluding the head) at each air temperature (Ta = 25, 20, 10 degrees C) and water temperature (Tw = 29–33 degrees C) were used in a linear approximation of overall heat transfer from body core (Tre) to air or water. We found the lower critical air and water temperatures to fall as a negative linear function of MSF. The slope of these lines was not significantly different in air and water with a mean of minus 0.237 degrees C/mm MSF. Overall heat conductance was 3.34 times greater in water. However, this value was not fixed but varied as an inverse curvilinear function of MSF. Thus, equivalent water-air temperatures also varied as a function of MSF. Between limits of 100–250% of resting heat loss the followingrelationships between MSF and equivalent water-air temperatures were found (see article).

Tuning the thermoelectric properties of a single-molecule junction by mechanical stretching

2015 ◽  
Vol 17 (7) ◽  
pp. 5386-5392 ◽  
Author(s):  
Alberto Torres ◽  
Renato B. Pontes ◽  
Antônio J. R. da Silva ◽  
Adalberto Fazzio
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Single Molecule ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Heat Conductance ◽  
Molecule Junction ◽  
Electronic Heat ◽  
Single Molecule Junction ◽  
Mechanical Stretching

We theoretically investigate, as a function of the stretching, the behaviour of the Seebeck coefficient, the electronic heat conductance and the figure of merit of a molecule-based junction composed of a benzene-1,4-dithiolate (BDT) molecule coupled to Au(111) surfaces at room temperature.

Highly Regulatable Heat Conductance of Graphene–Sericin Hybrid for Responsive Textiles

2022 ◽  
pp. 2111121
Author(s):  
Xiaoping Liang ◽  
Aoran Fan ◽  
Zhen Li ◽  
Ning Wei ◽  
Wei Fan ◽  
...  
Keyword(s):  
Heat Conductance

scholarly journals Possibilities of improving the wheel tractor drive force transmission to soil

2016 ◽  
Vol 61 (Special Issue) ◽  
pp. S37-S42
Author(s):  
R. Abrahám ◽  
R. Majdan ◽  
R. Drlička
Keyword(s):  
Soil Moisture ◽  
Moisture Level ◽  
Force Transmission ◽  
Wheel Slip ◽  
Drive Force ◽  
Base Position ◽  
Drive Axle ◽  
Moisture Conditions ◽  
Drawbar Pull

The possibility of increasing maximal drawbar pull of tractor working on the soil was evaluated. The increase in drawbar pull occurred due to special wheels mounted on the drive axle. The special wheels were equipped with auto-extensible blades and designed at the Slovak University of Agriculture in Nitra. The main advantage of the special wheels is an automatic extension of steel blades to increase the drawbar pull during a wheel slip and automatic return to the base position to allow the transport of tractor by the route. The testing operation points at the decrease of wheel slip resulted in the increase of drawbar pull. The drawbar pull of tractor equipped with standard tyres and special wheels was compared in different soil moisture conditions. The higher increase in drawbar pull was measured during the tractor operation on the soil with higher moisture in comparison to the soil with lower moisture level.

Role of skin and of core temperatures in man's temperature regulation

1965 ◽  
Vol 20 (1) ◽  
pp. 31-36 ◽  
Author(s):  
C. H. Wyndham
Keyword(s):  
Skin Temperature ◽  
Rectal Temperature ◽  
Temperature Regulation ◽  
Passive Control ◽  
Sweat Rate ◽  
Heat Conductance ◽  
Response Characteristics ◽  
Highly Nonlinear ◽  
The Right ◽  
Skin Temperatures

The response characteristics have been studied of the curves relating heat conductance and sweat rate to change in rectal temperature at different levels of skin temperature, and vice versa. The increase in these responses with deviation in rectal temperature from the “neutral” setting is highly nonlinear; the neutral point and the curve shift to the right and the slope decreases with lowering of skin temperature and vice versa when it is raised. With further deviation of rectal temperature these responses reach maximum values, i.e., become “saturated.” All of these features are analogous to servomechanisms with negative feedback, giving sensitive and stable control. Control of these responses by skin temperature is more linear, characterizing passive control systems which are insensitive and less stable. Quantitatively, the effect at skin temperature of 26 C of 1 C rise in rectal temperature on heat conductance and sweat rate is 10 times greater than the same rise in skin temperature; at a neutral skin temperature of 33–34 C, a rise of 1 C in rectal temperature is 6–7 times greater; at a high skin temperature of 36 C, a rise in rectal temperature of 1 C is 4–5 times greater. relationship between heat conductance and a change in either rectal or skin temperatures; relationship between sweat rate and a change in either rectal or skin temperatures; response characteristics of curves relating heat conductance to change in either rectal or skin temperatures; response characteristics of curves relating sweat rate to change in either rectal or skin temperatures; assessment of the contribution of skin and rectal temperatures to man's temperature regulation Submitted on October 22, 1963

Simulation and Analysis of Metal Microfluidic Heatsinks

2006 ◽  
Author(s):  
Alireza Motieifar ◽  
C. Shafai ◽  
H. M. Soliman
Keyword(s):  
Thermal Resistance ◽  
Cross Section ◽  
Fluid Velocity ◽  
The Body ◽  
Silicon Substrates ◽  
Channel System ◽  
Heat Conductance ◽  
Fem Method ◽  
Rectangular Channels ◽  
Electroplated Copper

Microfluidic heatsinks are usually fabricated in silicon substrates using micromachining methods. Fabrication of microfluidic heatsinks in metals is captivating due to the potential of higher heat conductance of many metals compared to silicon. In this work, metallic microfluidic structures fabricated of copper, silicon, and nickel are simulated and analyzed using the FEM method. The parametric dependence of the overall thermal resistance on the heatsink material, fluid velocity, and channel geometry is examined. Their performance is compared based on the shape and size of the microchannels, their separating distance from each other, and the flow rate. Simulations were done using FEMLAB v.3.2 (Comsol Multyphysics). The length of the microchannels considered is 1cm. Their cross section is rectangular. Simulated heatsinks are covered with 50 μm of the same material as the body and the total area of the heat sink is 1cm × 1cm. Water is used as the coolant with an input temperature of 300 K. These simulations show that most of the thermal resistance in the heatsink occurs in the fluid region. For the constant and uniform input heating power of 100 W/cm2 the performance of the structure is studied at steady state with the fluid velocity varied from 1 to 14m/s. Finally, experimental fabrication of an electroplated copper micro-channel system with rectangular channels is shown.

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