Engineering

A supra-photothermal catalyst inspired by the greenhouse effect

Over the past few decades, scientists worldwide have developing a variety of techniques and technologies that can convert carbon dioxide (CO2) into fuel using solar energy. This would ultimately be highly valuable, as it ...

Energy & Green Tech

Green roof or solar? It turns out both is best

The benefits of combining solar panel installations with green roofs has been confirmed by new research, which demonstrates significant improvements in energy production, stormwater filtration and most surprisingly, a major ...

Energy & Green Tech

Energy renovation: First sort, then refurbish

Heating and cooling of buildings is a major contributor to CO2 emissions in all industrialized countries. To achieve the Swiss government's climate targets—net zero by 2050—Switzerland's building stock must thus also ...

Energy & Green Tech

The Basque Country's industrial waste heat could be reusable

Many traditional industrial processes generate heat that is normally released into the atmosphere but that could be reused. In production processes such as smelting, iron and steel, paper or cement, between 35 and 50 percent ...

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Heat

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