| HF | Hageman factor; haplotype frequency; hard filled [capsule]; hay fever; head of fetus; head forward; ... |
|---|---|
| HPLC | high-performance liquid chromatography; high-power liquid chromatography; high-pressure liquid chrom... |
| HT | Hashimoto thyroiditis; hearing test; hearing threshold; heart; heart transplantation, heart transpla... |
| HEI | Health Effects Institute; high-energy intermediate; homogenous enzyme immunoassay; human embryonic i... |
| HEIR | health effects of ionizing radiation; high-energy ionizing radiation |
energetics
| bioelectric energy sources | Implantable devices which convert biological energy (chemical energy of the metabolism of continuously regenerating body fluids or mechanical energy of periodic movements) to electrical energy. The sources include biogalvanic cells, biofuel cells, and ionic concentration cells. (12 Dec 1998) |
|---|---|
| biomass energy | See Bioenergy. (05 Dec 1998) |
| bond dissociation energy | This is the energy needed to break the bonds between two linked atoms. (09 Oct 1997) |
| bond energy | The energy needed to break a molecular bond. (09 Oct 1997) |
| calcium compound | Inorganic compounds that contain calcium as an integral part of the molecule. (12 Dec 1998) |
| carbamino compound | Any carbamic acid derivative formed by the combination of carbon dioxide with a free amino group to form an N-carboxy group, -NH-COOH, as in haemoglobin forming carbaminohemoglobin. (05 Mar 2000) |
| carbocyclic compound | See: cyclic compound. (05 Mar 2000) |
| radiant energy | Energy contained in light rays or any other form of radiation. (05 Mar 2000) |
| radiography, dual-energy scanned projection | A method of producing a high-quality scan by digitizing and subtracting the images produced by high- and low-energy X-rays. (12 Dec 1998) |
| Parallel Electron Energy Loss Spectroscopy | <technique> Electron energy loss spectroscopy analyses the inelastically scattered electrons present in the beam after it has been transmitted through the sample. An electron energy loss spectrum typically consists of a monatomic decreasing background on which are superimposed a number of peaks. Each peak is characteristic of the scattering process that has occurred in the sample. The peaks can be used to obtain information about the chemical composition and electronic structure of the sample. Electron energy loss spectra are acquired typically in a magnetic sector spectrometer located under the camera chamber of the transmission electron microscope. Spatial resolution is typically limited by the minimum probe diameter of the microscope. Electron energy loss spectroscopy tends to be complimentary to EDS in that it can be used to analyse very thin samples of low Z materials. Acronym: PEELS (05 Aug 1998) |
| genetic compound | In medical genetics, the presence of two different mutant alleles at the same loci. Synonym: genetic compound. (05 Mar 2000) |
| geothermal energy | Energy derived from the natural heat of the Earth contained in hot rocks, hot water, hot brines or steam. (05 Dec 1998) |
| mass energy absorption coefficient | <physics> The mass energy absorption coefficient, uen/p of a material for uncharged ionising particles is the product of the mass energy transfer coefficient, utr/p and (1 - g) where g is the fraction of the energy of secondary charged particles that is lost to bremsstrahlung in the material. (16 Dec 1997) |
| Gibbs energy of activation | The Gibbs energy that must be added to that already possessed by a molecule or molecules in order to initiate a reaction. (05 Mar 2000) |
| gibbs free energy | The total amount of energy which is either used up or released during a chemical reaction. Gibbs free energy (delta G) = (delta H) - t (delta s): where (delta H) is the change in enthalpy, calculated by adding up the amount of energy released or used up to break or form chemical bonds during the reaction, t is the temperature at which the reaction took place, and (delta S) is the change in entropy, or amount of disorder, that occurs in the molecules involved during the reaction. (09 Oct 1997) |