Energy & Green Tech

See-through film rejects 70 percent of incoming solar heat

To battle the summer heat, office and residential buildings tend to crank up the air conditioning, sending energy bills soaring. Indeed, it's estimated that air conditioners use about 6 percent of all the electricity produced ...

Engineering

Engineering team designs technology for smart materials

University of Virginia mechanical engineers and materials scientists, in collaboration with materials scientists at Penn State, the University of Maryland and the National Institute of Standards and Technology, have invented ...

Engineering

'Artificial blubber' protects divers in frigid water

When Navy SEALs carry out dives in Arctic waters, or when rescue teams are diving under ice-covered rivers or ponds, the survival time even in the best wetsuits is very limited—as little as tens of minutes, and the experience ...

Energy & Green Tech

Dandelion wants to play a role in home geothermal

Not familiar with residential geothermal heating? No surprise. Chris Martin in Bloomberg explained that "Residential geothermal heating is uncommon, in part because the expense and effort to dig the wells make them costly ...

Consumer & Gadgets

Raspberry Pi 3 Model B+ is latest member with same affordable price

Say hello to the new Raspberry Pi 3 Model B+. "Alongside a 200MHz increase in peak CPU clock frequency, we have roughly three times the wired and wireless network throughput, and the ability to sustain high performance for ...

Energy & Green Tech

Firebricks offer low-cost storage for carbon-free energy

Firebricks, designed to withstand high heat, have been part of our technological arsenal for at least three millennia, since the era of the Hittites. Now, a proposal from MIT researchers shows this ancient invention could ...

Energy & Green Tech

Self-powered system makes smart windows smarter

Smart windows equipped with controllable glazing can augment lighting, cooling and heating systems by varying their tint, saving up to 40 percent in an average building's energy costs.

Energy & Green Tech

Researchers plant seeds to make renewable energy more efficient

Greg Barron-Gafford kneels amid chard, kale, cabbage and onions growing lush beneath a solar panel. An iPad in hand, he checks and records the plants' carbon dioxide uptake and the soil's moisture. He makes note of the plants' ...

Energy & Green Tech

Americans use more clean energy in 2016

Americans used more renewable energy in 2016 compared to the previous year, according to the most recent energy flow charts released by Lawrence Livermore National Laboratory. Overall, energy consumption was nearly flat.

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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