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FWIW, "boron doping to a nominal level of 10^20 atoms/cm3 increases the expansion coefficient of Si over the range 293–550 K by 1.1×10^-8/K" (Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films (Volume:9 , Issue: 4, p. 2231)(1991). I don't know about phosphorus-doped silicon, but probably CTE change due to doping at your level is also ...


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Several things are happening here that may make the sensations of touching metal and touching water similar when they are at room temperature (~ 25 C), although the thermal conductivities are a couple of orders of magnitude different. The sensation of coldness comes from the loss of heat from the part of your body contacting the material. The rate of heat ...


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The parts of your body that generate heat and that can sense temperature and the loss of heat are insulated from the environment by a layer of dead skin cells. The total thermal conductivity to the environment is the thermal conductivity of the materials that you touch in series with the thermal conductivity of this layer of skin. Since this layer has a ...


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I strongly suspect that if you want your bath water to cool slowly, you want the least thermally conductive material you can get. Acrylic or any plastic will be better than steel will be better than copper. Let's assume you fill the tub over a time span of a few minutes and regulate the temperature to be perfect just as the tub gets as full as you like it. ...


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The thermal diffusivity can indeed be spatially dependent--consider the case you present: an iron bar fixed to a cool copper bar with one end being heated, clearly there is a disjoint in the value at the joining point. Now extend that idea to say 100 alternating blocks of iron & copper and you have a nice clear spatially dependent coefficient. ...



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