Energy & Green Tech

Scientists reduce all-solid-state battery resistance by heating

All-solid-state batteries are now one step closer to becoming the powerhouse of next-generation electronics, as researchers from Tokyo Tech, National Institute of Advanced Industrial Science and Technology (AIST), and Yamagata ...

Energy & Green Tech

New smart-roof coating enables year-round energy savings

Scientists have developed an all-season smart-roof coating that keeps homes warm during the winter and cool during the summer—without consuming natural gas or electricity. Research findings reported in the Dec. 17 edition ...

Energy & Green Tech

Recycled factory heat benefits industries and the environment

Industrial processes account for more than a fourth of Europe's primary energy consumption and produce a tremendous amount of heat. EU funded research is closing the circle with novel systems that recover waste heat and return ...

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In physics and thermodynamics, heat is the process of energy transfer from one body or system to another due to a difference in temperature. In thermodynamics, the quantity TdS is used as a representative measure of the (inexact) heat differential δQ, which is the absolute temperature of an object multiplied by the differential quantity of a system's entropy measured at the boundary of the object.

A related term is thermal energy, loosely defined as the energy of a body that increases with its temperature. Heat is also loosely referred to as thermal energy, although many definitions require this thermal energy to actually be in the process of movement between one body and another to be technically called heat (otherwise, many sources prefer to continue to refer to the static quantity as "thermal energy"). Heat is also known as "Energy".

Energy transfer by heat can occur between objects by radiation, conduction and convection. Temperature is used as a measure of the internal energy or enthalpy, that is the level of elementary motion giving rise to heat transfer. Energy can only be transferred by heat between objects - or areas within an object - with different temperatures (as given by the zeroth law of thermodynamics). This transfer happens spontaneously only in the direction of the colder body (as per the second law of thermodynamics). The transfer of energy by heat from one object to another object with an equal or higher temperature can happen only with the aid of a heat pump, which does work.

This text uses material from Wikipedia, licensed under CC BY-SA