Measurement of energy

Ensher J R, Jin D S, Mathews M R, Weman C E and Cornell E A 1996 Bose-Einstein condensation in a dilute gas measurement of energy and ground-state occupation Phys. Rev. Lett. 77 4984-7... 

Barker J R 1984 Direct measurement of energy transfer in rotating large molecules in the electronic ground state J. Chem. Phys. 88 11... 

Cavanagh R R, Fleilweil E J and Stephenson J C 1994 Time-resolved measurements of energy-transfer at surfaces Surf. Sc/. 300 643-55... 

Kim Y R, Share P, Pereira M, Sarisky M and Hoohstrasser R M 1989 Direot measurements of energy-transfer between identioal ohromophores in solution J. Chem. Rhys. 91 7557-62... 

Several additional terms related to the absorption of x-radiation require definition energy of a x-ray photon is properly represented in joules but more conveniently reported in eV fluence is the sum of the energy in a unit area intensity or flux is the fluence per unit time and the exposure is a measure of the number of ions produced in a mass of gas. The unit of exposure in medicine is the Rn ntgen, R, defined as the quantity of radiation required to produce 2.58 x C/kg of air. The absorbed dose for a tissue is a measure of energy dissipated per unit mass. The measure of absorbed dose most... 

The magnitude of shocks and vibrations caused by an earthquake is the measure of energy released (E) at the focal point in the form of seismic waves. It is measured on a Richter scale. An American seismologist called... 

Around the beginning of this century, cancer and illness was associated with excessive use of X-rays. Watch dial painters got mouth cancer from radium in the paint. It soon was realized that radiation has health effects. The measures of energy deposition concepts introduced... 

Measurements of energy are made in terms of absolute joules, but engineering practice has persistently retained the thermochemical calorie as the unit of energy. The two are related by the definition ... 

Sound intensity is a measure of energy, and its units are watts per meter. Intensity is proportional to the square of pressure ... 

Whereas heat capacity is a measure of energy, thermal diffusivity is a measure of the rate at which energy is transmitted through a given plastic. It relates directly to processability. In contrast, metals have values hundreds of times larger than those of plastics. Thermal diffusivity determines plastics rate of change with time. Although this function depends on thermal conductivity, specific heat at constant pressure, and density, all of which vary with temperature, thermal diffusivity is relatively constant. 

Schoeller, D.A. 1988 Measurement of energy expenditure in free-living humans by using doubly labeled water. Journo/of Nutrition 118 1278-1289. 

Energy Requirements Are Estimated by Measurement of Energy Expenditure... 

Fantozzi, F. Bartocci, P. D Alessandro, B. Testarmata, F. Fantozzi P. Carbon footprint of truffle sauce in central Italy by direct measurement of energy consumption of different olive harvesting techniques. J. Clean. Prod. 2015, 87,188-196. 

The energy involved in chemical reactions is often as important as the chemical products. For example, the fuel used in home furnaces and in automobiles is used solely for their energy content, and not for the chemical products of their combustion. The measurement of energy is discussed in Sec. 18.2, heat capacity is discussed in Sec. 18.3, the energy involved in changes of phase is treated in Sec. 18.4, and the energy involved in physical and chemical processes is taken up in Sec. 18.5. 

Calorimetry is the measurement of energy changes accompanying chemical or physical changes. We usually want to know how much energy is liberated or consumed per unit mass or mole of... 

A summary of the electrochemical formulae developed above is provided in Table 7.3. AG, pe, E, and K contain virtually the same thermodynamic information. While is the quantity that is analytically measured, pe is preferred by marine chemists as it is temperature independent and numerically easier to work with. AG is often used to compare the relative stability of species because it provides a measure of energy yields in units of calories or joules. A comparison of the three electrochemical scales at 25°C is given in Figure 7.3. The merits of each thermodynamic parameter will become evident in the next section of the chapter where the energetics of some marine redox processes are considered. 

Quantitative studies of energy metabolism and fuel utilisation in very prolonged physical activity were performed by Mike Stroud during his Antarctic expedition with Ranulph Fiennes in 1992. One part of the study was measurement of energy expenditure by the dual isotope techniques (Chapter 2). Calculated over the whole expedition, the average daily energy expenditure of Stroud and Fiennes was 29 MJ but on particularly arduous days it increased to... 

In practice, animal calorimetry is quite complicated because of the inherent difficulty of accurate heat measurements, uncertainties about the amount of food stored, and the necessity of corrections for AHc of the waste products. However, the measurement of energy metabolism has been of considerable importance in nutrition and medicine. Indirect methods of calorime-tery have been developed for use in measuring the basal metabolic rate of humans. For a good discussion see White et al.u... 

Bond Energy. A measure of energy reqd to disrupt a chemical bond. The definitions as used in phvs chem axe discussed in Refs 1 2 Refs 1)H.A.Skinner H.D.Springall,Nature 162, 343-44(1948) 2)L.H.Long, Nature 162,344-45(1948)... 

The problem of quenching alkali resonance radiation in E-VR energy-transfer collisions with simple molecules is important as a model case for basic processes in photochemistry and serves its own right for a variety of practical applications, such as in laser physics. It has been studied for many years in the past, but only recent progress has led to information of the final internal energy of the molecule. In particular, crossed-beam experiments with laser-excited atoms allow a detailed measurement of energy-transfer spectra. There can be no doubt that the curve-crossing... 

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