Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Parameters absolute

Thus, recording and analysis of EPR spectra of lattice metal ions in their paramagnetic state, changes of the spin-Hamiltonian parameters, absolute and relative concentration of the species as a result of influence of external conditions such as heat treatment, light irradiation, chemical reactions, gas evaporation, etc., provide a valuable information about the structure and properties of oxide semiconductor materials. The results of the EPR studies of On and NxOy radicals will be discussed below. [Pg.209]

It should be noted that the correct substitution for the pressure terms in the above equations is always the absolute pressure. Physical laws follow the natural measures of the parameters. Absolute pressures, absolute temperatures, and the like are natural measures of these parameters. Gage pressures and the temperature measurements of Celsius and Fahrenheit are expedient or relative measures. This is unfortunate, since oftentimes, it causes too much confusion however, these relative measures have their own use, and how they are used must be fully understood, and the results of the calculations resulting from their use should be correctly interpreted. If confusion results, it is much better to use the absolute measures. [Pg.236]

Applying first principles to measurements of the ESR signal and to all pertinent instrumental parameters, absolute numbers of spins can be determined. However, this is rarely done since the number of variables to be controlled is considerable and the labor involved is disproportionate. Relative concentrations of species with the same spectral shape and line widths can be determined simply by comparing peak heights of the normal first-derivative curve under identical conditions, i.e.. [Pg.379]

Element k,l of the variance-covariance matrix for the polynomial parameters absolute temperature boundary temperature critical temperature... [Pg.10]

MAXIMUM ABSOLUTE VALUE OF PARAMETER CHANGES WHEN LMP EQUAL 2... [Pg.229]

Restoring of SD of parameters of stress field is based on the effect of acoustoelasticity. Its fundamental problem is determination of relationship between US wave parameters and components of stresses. To use in practice acoustoelasticity for SDS diagnosing, it is designed matrix theory [Bobrenco, 1991]. For the description of the elastic waves spreading in the medium it uses matrices of velocity v of US waves spreading, absolute A and relative... [Pg.250]

The usual experimental situation is that of a sessile drop and, as with the pendant drop, it is necessary to determine a shape parameter and some absolute length. Thus /3 may be determined by profile fitting, and Ze measured, where Ze is the distance from the plane at = 90 to the apex. If the drop rests with... [Pg.28]

In general the width of the coexistence line (Ap, Ax, or AM) is proportional to an order parameter s, and its absolute value may be written as... [Pg.639]

The relative simplicity of tlie method and the penetrative nature of the x-rays, yield a technique that is sensitive to elements with Z > 10 down to a few parts per million (ppm) and can be perfonued quantitatively from first principles. The databases for PIXE analysis programs [21, 22 and 23] are typically so well developed as to include accurate fiindamental parameters, allowing the absolute precision of the technique to be around 3% for major elements and 10-20% for trace elements. A major factor m applying the PIXE teclmique is that the bombardmg energy of the... [Pg.1841]

Quack M, Sutcliffe E, Hackett P A and Rayner D M 1986 Molecular photofragmentation with many infrared photons. Absolute rate parameters from quantum dynamics, statistical mechanics, and direct measurement Faraday Discuss. Chem. Soc. 82 229-40... [Pg.2152]

The question of determination of the phase of a field (classical or quantal, as of a wave function) from the modulus (absolute value) of the field along a real parameter (for which alone experimental determination is possible) is known as the phase problem [28]. (True also in crystallography.) The reciprocal relations derived in Section III represent a formal scheme for the determination of phase given the modulus, and vice versa. The physical basis of these singular integral relations was described in [147] and in several companion articles in that volume a more recent account can be found in [148]. Thus, the reciprocal relations in the time domain provide, under certain conditions of analyticity, solutions to the phase problem. For electromagnetic fields, these were derived in [120,149,150] and reviewed in [28,148]. Matter or Schrodinger waves were... [Pg.104]

The viscosity average molecular weight is not an absolute value, but a relative molecular weight based on prior calibration with known molecular weights for the same polymer-solvent-temperature conditions. The parameter a depends on all three of these it is called the Mark-Houwink exponent, and tables of experimental values are available for different systems. [Pg.42]

It is extremely difficult to know values for all of these parameters precisely. Therefore, absolute quantitation is almost never attempted. The determination of relative atomic ratios is an inherently more tractable approach, however. This method is best illustrated by consideration of a binary material composed exclusively of atoms A and B that is perfectiy homogeneous up to the surface. In this case, independent equations can be developed relating the number of atoms sampled to the xps intensity for each atom as follows ... [Pg.278]

Activation Parameters. Thermal processes are commonly used to break labile initiator bonds in order to form radicals. The amount of thermal energy necessary varies with the environment, but absolute temperature, T, is usually the dominant factor. The energy barrier, the minimum amount of energy that must be suppHed, is called the activation energy, E. A third important factor, known as the frequency factor, is a measure of bond motion freedom (translational, rotational, and vibrational) in the activated complex or transition state. The relationships of yi, E and T to the initiator decomposition rate (kJ) are expressed by the Arrhenius first-order rate equation (eq. 16) where R is the gas constant, and and E are known as the activation parameters. [Pg.221]

In drafting a patent appHcation, proceeding methodically through the several steps necessary to produce the type of disclosure legally and technically sufficient to satisfy the requirements of the laws of the United States is absolutely essential to a successful granting of the patent. A first step is to outHne those elements of the invention which are absolutely essential to its practice. A body of disclosure should be outlined for each of the essential elements of the claim. This disclosure should describe each element in terms of its function, as weU as the parameters that are relevant to the essential nature of the individual element. For example, if a chemical mixture has a component which acts so as to thicken the mixture, it is appropriate to outHne the family of constituents that can serve this function. At the same time, a full outHne of the disclosure of this individual element will include mention of those chemicals that are preferred for use within the mixture so as to perform the desired thickening function. [Pg.34]

The transient current, derivable from equation 1, is given in equations 2 and 3 where T is the transit time and I is the absorbed photon flux. The parameter a can be further derived as equation 4 (4), where Tis the absolute temperature and is the distribution width (in units of kT) of a series of exponential traps. In this context, the carrier mobdity is governed by trapping and detrapping processes at these sites. [Pg.411]

A viscoelastic material also possesses a complex dynamic viscosity, rj = rj - - iv( and it can be shown that r = G jiuj-, rj = G juj and rj = G ju), where CO is the angular frequency. The parameter Tj is useful for many viscoelastic fluids in that a plot of its absolute value Tj vs angular frequency in radians/s is often numerically similar to a plot of shear viscosity Tj vs shear rate. This correspondence is known as the Cox-Merz empirical relationship. The parameter Tj is called the dynamic viscosity and is related to G the loss modulus the parameter Tj does not deal with viscosity, but is a measure of elasticity. [Pg.178]

The critical parameters of steam sterilization are temperature, time, air elimination, steam quaUty, and the absence of superheating. Temperature and time are interrelated, as shown in equation 8. The success of steam sterilization is dependent on direct steam contact which can be prevented by the presence of air in the chamber. The abiUty of steam to heat a surface to a given temperature is considerably reduced by the presence of air. Air elimination, therefore, is regarded as an absolute parameter. If the required amount of air has not been eliminated from the chamber and the load, no combination of time and temperature results in complete sterilization. [Pg.408]

Much can be predicted from these parameters. Linear correlations have been estabhshed between the R value and the drawabhity parameter, LDR. Thus higher R values are associated with better deep drawabhity. AR, on the other hand, predicts the height and location of ears. Eor example, larger absolute values of AR predict higher ears during deep drawing cup shapes. [Pg.223]

The absolute pressure may have a significant effect on the vapor—Hquid equiHbrium. Generally, the lower the absolute pressure the more favorable the equiHbrium. This effect has been discussed for the styrene—ethylbenzene system (30). In a given column, increasing the pressure can increase the column capacity by increasing the capacity parameter (see eqs. 42 and 43). Selection of the economic pressure can be faciHtated by guidelines (89) that take into consideration the pressure effects on capacity and relative volatiHty. Low pressures are required for distillation involving heat-sensitive material. [Pg.175]


See other pages where Parameters absolute is mentioned: [Pg.473]    [Pg.155]    [Pg.60]    [Pg.591]    [Pg.354]    [Pg.473]    [Pg.155]    [Pg.60]    [Pg.591]    [Pg.354]    [Pg.222]    [Pg.318]    [Pg.755]    [Pg.27]    [Pg.148]    [Pg.753]    [Pg.1283]    [Pg.1583]    [Pg.2369]    [Pg.235]    [Pg.189]    [Pg.499]    [Pg.158]    [Pg.83]    [Pg.660]    [Pg.260]    [Pg.67]    [Pg.101]    [Pg.171]    [Pg.350]    [Pg.515]   
See also in sourсe #XX -- [ Pg.204 ]




SEARCH



Absolute Arrhenius parameters

Absolute Arrhenius parameters rate constants

Absolute Configuration and Detailed Structural Parameters

Absolute Hardness Parameters

Absolute rate activation parameters

© 2024 chempedia.info