| conservation of energy | The principle that the total amount of energy in a closed system remains always the same, none being lost or created in any chemical or physical process or in the conversion of one kind of energy into another, within that system. (05 Mar 2000) |
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| conservation of energy resources | Planned management, use, and preservation of energy resources. (12 Dec 1998) |
| potential energy | <chemistry> Energy due to position, it is stored energy which can be used to do work. (09 Jan 1998) |
| primary energy | <radiobiology> Energy before conversion. For instance, the United States uses about 30,000 megajoules of electricity per capita per year, but electricity is generally obtained by converting other forms of energy (primarily chemical/heat) at an efficiency of around 30%, so the U.S. Consumes 90,000 megajoules of primary energy per capita for electrical use. (Total U.S. Primary energy consumption is 300,000 megajoules per capita.) (09 Oct 1997) |
| Helmholtz energy | Energy equivalent to the internal energy minus the entropy contribution (TS). (05 Mar 2000) |
| protein-energy malnutrition | The lack of sufficient energy or protein to meet the body's metabolic demands, as a result of either an inadequate dietary intake of protein, intake of poor quality dietary protein, increased demands due to disease, or increased nutrient losses. (12 Dec 1998) |
| high energy compounds | Classically, a group of phosphoric esters whose hydrolysis takes place with a standard free energy change of -5 to -15 kcal/mol (or, -20 to -63 kJ/mol) (in contrast to -1 to -4 kcal/mol or, -4 to -17 kJ/mol) for simple phosphoric esters like glucose-6-phosphate or alpha-glycerophosphates), thus being capable of driving energy-consuming reactions in living cells or reconstituted cell-free systems; adenosine 5'-triphosphate, with respect to the beta-and gamma-phosphates, is the best known and is regarded as the immediate energy source for most metabolic syntheses. The general types are acid anhydrides, phosphoric esters of enols, phosphamic acid (R-NH-PO3H2) derivatives, acyl thioesters (e.g., of coenzyme A), sulfonium compound's (R3-S+), and aminoacyl esters of ribosyl moieties. See: high energy phosphates. (05 Mar 2000) |
| high energy particle generating unit | A machine capable of providing highly energised radiation for the purposes of radiotherapy treatment. (16 Dec 1997) |
| high energy phosphates | Those phosphate's that, on hydrolysis, yield an unusually large amount of energy; e.g., nucleotide polyphosphates such as ATP, enol phosphate's such as phosphoenolpyruvate. See: high energy compounds. Synonym: energy-rich phosphates. (05 Mar 2000) |
| high-energy shock waves | Compression waves of large amplitude, across which density, pressure, and particle velocity change drastically. (12 Dec 1998) |
| psychic energy | In psychoanalysis, a hypothetical mental force, analogous to the physical concept of energy, which enables and vitalises an individual's psychological activity. See: libido. Synonym: psychic force. (05 Mar 2000) |
| short rotation energy plantation | Plantings established and managed under short-rotation intensive culture practices. (05 Dec 1998) |
| small scale energy loan program | (SELP) A low-cost loan and technical assistance program administered by the Oregon Department of Energy. (05 Dec 1998) |
| solar energy | Energy transmitted from the sun in the form of electromagnetic radiation. (12 Dec 1998) |
| nuclear binding energy | <physics> The difference between the total energy (= mc^2) of the bound nucleus, and the energies of the individual constituent particles (= sum of masses c^2). The nuclear binding energy per nucleon is a maximum for iron. Fusion releases energy because light nuclei are less tightly bound than medium-weight nuclei, and thus energy is liberated when they become more tightly bound after fusing. Fission releases energy for the same reason - heavy nuclei are also less tightly bound than medium-weight nuclei, and energy is liberated when heavy nuclei split into lighter nuclei. (09 Oct 1997) |