# Tagged Questions

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### Is perfect thermal insulation possible?

Supposing someone says they have a sample of insulanium with the following properties: If you make a thermos out of insulanium, it will keep a drink hot or cold forever. If you put your hand on a ...
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### Is it possible for an object to have low specific heat capacity and low thermal conductivity?

As I see, there are many examples of object with low specific heat capacity and high thermal conductivity and vice versa. Since they are different properties of matter and their definitions are not ...
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### Finding effective thermal conductivity multi-layer cylinder

How does one find the effective thermal conductivity of a cylindrical body made of multiple layers? E.g. Copper core (k1), insulator 1 (k2) and insulator 2 (k3). I need the effective properties for ...
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### Work done in adiabatic reversible process

I was solving a problem on turbine.the steam works on turbine adiabatic reversibly .Is change in enthalpy or is it change in internal energy which equal this work?
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### Calculating new temperature of an object when air temperature changes

I'm trying to calculate the new temperature of an object when the air temperature around it changes, given a period of time. Basically I get periodic readings from an air temperature sensor in a ...
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### thermal fatigue and thermal conductivity

Today I argued that heating and cooling a metal many times will affect its thermal conductivity. My idea is that heating and cooling, ie. thermal fatigue, will affect longterm the the microstructure ...
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### Kubo formula for thermopower (seebeck coefficient)

I have a long-standing puzzle about the Kubo formula relating to the thermopower defined as S=L_{21}/L_{11}. Here L_{ij} are elements a 2 × 2 matrix of transport coefficients, with J_E=L_{11} E - L_{...
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### How do you go from the heat equation to calculate the steady state heat transfer to the end of a rod?

Heat equation: $$k\nabla \cdot \nabla T + \dot{q} = \rho C_p\frac{\partial T}{\partial t}$$ I want to know given a rod or a cylinder of material, but lets start simply with a rectangular rod, and ...
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### Activation energy as a function of defects

Electrical conductivity has a form of Arrhenius equation. It is assumed that activation energy decreases with defect density in the insulating state and becomes zero in the conducting state. Can one ...
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### How water and honey behave with increasing pressure?

Is there any relation between pressure and viscosity of water and honey? I hardly found the topic. Is it related to the Laplace law?
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### Thermal conductivity in vacuum

It is my assumption that material objects preserve/gain heat via: 1) material contact (air or other touching material/object) and/or 2) absorbing radiation / electromagnetic waves So, imagine that ...
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### Thermal conductivity in gases

I've been musing about thermal conductivity and came upon the following question. Heat is transported through matter by molecules passing their kinetic energy onto other molecules, or simply by the ...