Efficiency number

Section 3.4, Table 3-3, provides some insight as to where the major losses occur and to what degree. The losses highlighted in that table are for the basic PWM switching power supply without much effort placed into making them more efficient. These efficiency numbers, therefore, can be seen as the baseline... 

Column efficiency (number of theoretical plates) As in batch chromatography, one needs to determine the efficiency of the column in order to evaluate the dispersion of the fronts due to hydrodynamics dispersion or kinetics limitations. The relationship of N proportional to L can be expressed in terms of the equation for height equivalent to a theoretical plate (HETP) as ... 

Between 1923 and 1927, the concepts of quantum efficiency (number of photons emitted divided by number of photons absorbed by a sample) and quantum yield (fraction of excited molecules that emit) had been defined and values determined for many compounds by Vavilov (34). The quantum yield indicates the extent that other energy loss mechanisms compete with emission in an excited molecule. Although the quantum yield is influenced by the molecular environment of the emitter, for a given environment it depends on the nature of the emitting compound and is independent of concentration and excitation wavelength, at least at low concentrations (35). Tlius, it serves as another measurable parameter that can be used to identify the compounds in a sample and also, because of its sensitivity to the surroundings of the luminophore, to probe the environment of the emitter. 

The literature is less extensive on the use of protoplasts in stress-tolerance investigations however, some applications have been attempted. For example, in one study protoplasts were isolated from the leaves of a wild relative of tomato shown to be salt tolerant and from a salt-sensitive, cultivated species (Rosen Tal, 1981). In the presence of NaCI the plating efficiency (number of surviving cells/number of cells applied to the plate) of the wild relative was greater than the cultivated, sensitive cultivar. Proline, when added to the culture media, was found to enhance the plating efficiency of the salt-sensitive cultivar but not the wild, salt-tolerant relative. These results suggest that traits related to salt tolerance are expressed by the isolated protoplasts and that the response of protoplasts to environmental stress can be manipulated, i.e. the proline response. 

The overall process performance, as measured by photon efficiency (number of incident photon per molecule reacted, like the incident photon to current conversion efficiency, or IPCE, for PV cells), depends on the chain from the light absorption to acceptor/donor reduction/oxidation, and results from the relative kinetic of the recombination processes and interfacial electron transfer [23, 28]. Essentially, control over the rate of carrier crossing the interface, relative to the rates at which carriers recombine, is fundamental in obtaining the control over the efficiency of a photocatalyst. To suppress bulk- and surface-mediated recombination processes an efficient separation mechanism of the photogenerated carrier should be active. 

After the wash cycle, the spiked container is evaluated by suitable testing to determine the amount of residual contaminant. The before and after numbers can be compared to establish an efficiency number based on the original level of contaminant. 

Mechanical shock applied in ambient noble gas atmospere also emplaces substantial amount of noble gases into target material. Wiens and Pepin (1988) studied the effects of mechanical shock (20-60 GPa) applied to rock specimens (basalt disk and powder 63-125 pm in size) in ambient air. They found that emplacement efficiencies (number densities in shocked samples/number densities in ambient gases)... 

H2A analysis was used to predict hydrogen production costs as shown in Table 2. These results are based on the use of solar power tower as the heat source and also include assumptions that have yet to be validated. Work is ongoing in these areas. Nevertheless, the preliminary hydrogen production costs as well as the preliminary efficiency numbers indicate that the Cu-CI cycle has promise and that further R D is justifiable. 

ATPase reconstituted in vesicles of different lipid composition [26], Pumping efficiency (number of Ca2+ ions transported per molecule of ATP hydrolyzed) increased with the mole fraction of lipids that prefer Hn-phase formation. However, no such correlation was observed with dioleoylphosphatidylcholine or digalactosyldiglyc-eride, which do not form low-temperature H n phases. It is important to note that it is not the chemical similarity but the phase preference of the phospholipid that is decisive. 

Mercury him electrode Micro-total analytical system Molecularly imprinted polymer Multiple linear regression Multiwall carbon nanotube Collection efficiency Number of electrons transferred Normal pulse... 

The quantity in parentheses represents the dimensionless efficiency number E (which is a measure of mass-transfer rate per unit power input). The experiments indicate that... 

The design of pressure vessels must also take into consideration weld efficiency, number and size of openings, and also add additional thickness to allow for controlled corrosion over time and use. 

It is interesting to note that the bromine concentration in the electrolyte increases practically linearly with electrolysis time. A total of 49.3 g of bromine was produced during electrolysis from the electrolyte initially containing 55 g/L bromide. The current efficiency for overall electrolysis of the eluate was over 60%, which agrees well with current efficiency numbers for the tests using synthetic sodium bromide solutions. 

Kits for the preparation of diphosphonate complexes contain the lyophilized ingredients in a multidose vial. Labeling with Tc-pertechnetate is performed by adding 2-10 ml of sterile Tc eluate by aseptic techniques. When calculating the amount of radioactivity to be added, the labeling efficiency, number of patients, time of injection and radioactive decay must be taken into account. Activities corresponding to 6.6-18.5 GBq... 

Since typical biological mixtures are exceedingly complex, adequate chromatographic resolution is imperative for both identification and quantitation purposes. Improved resolution is feasible through either increasing the column efficiency (number of theoretical plates), or phase selectivity. Alternatively, a combination of both can be practiced. The number of theoretical plates, required for adequate resolution of two adjacent peaks (98% separation of the peak areas) is related to the column selectivity (relative retention, a) and to the capacity ratio, k, according to the well-known equation derived by Purnell [70] ... 

Determine the column diameter, tray efficiency, number of actual trays, and column height for the distillation column of Example 12.11 or 15.2 if perforated trays are used. 

The amount of aldehyde groups is usually used for evaluation of the intensity and efficiency (number of chain scissions per molecule of reacted ozone) of ozone degradation of elastomers. In this case, it should be taken into account that the dominant route of degradation leads to the formation of 1 mole of aldehyde from 1 mole of ozone [32]. 

Together with the equation to calculate resolution, shown above, another expression is used for poorly resolved peaks that relies on the efficiency (number of plates, Ath), the capacity, and the selectivity ... 

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