Static condenser method

Fig. 16. Example of a A s.p. = f(t) relation, manifesting surface potential changes in a nickel-hydrogen system as a function of time and amount of hydrogen introduced onto a surface of a nickel film deposited at liquid nitrogen temperature hydrogen-nickel film interactions were studied by Tompkins-Eberhagen static condenser method at liquid nitrogen temperature. After Dus (60). Each dose of H2 — 2.5 X 10 molecules.

A glass adsorption cell used for the static condenser method is shown in Fig. 14. The condenser is formed from two concentric cylinders separated by a 2 mm gap. 

Fig. 14. Cell for the measurement of contact potential difference by the static condenser method.

When adsorption and condensation can be avoided, both dynamic and static sampling methods can be used. Often rinsing the sampling apparatus or even the whole olfactometer with odorous air is necessary to reduce adsorption. Before using the static method a comparative study should be carried out if possible. On the other hand extreme fluctuating emissions can only be sampled statically. 

In all the DD methods described in this section, no reduction in the total number of degrees of freedom is made. Therefore, the error associated with static condensation of component mode synthesis where a set of degrees of freedom is eliminated firom the calculation does not appear here. However, approximations arise from usage of iterative solvers. The main goal here is to reduce the total computational cost by distributing the total computational burden among a... 

Static fatigue is the slow growth of a crack under ambient stress and environmental conditions. The static fatigue failure in oxide materials can be accelerated by moisture or hydrogen, which weaken the chemical bonds at the crack tip. This moisture can be supplied by breathing on the films to condense moisture. This moisture condensation method is an easy way to quickly determine if the residual film stresses are high or the adhesion is poor, and the nature (compressive or tensile stress) of the stresses in a film. This moisture condensation is the basis of the bad breath adhesion test (Sec. 12.5.2). 

The main difficulty in the static method is to obtain the liquid in a sufficiently pure state. The test of this is the constancy of vapour pressure when the liquid is evaporated, or the vapour condensed, since impurities usually divide themselves unequally between liquid and vapour. 

Although the procedure described utilizes metal vessels for ease of treating the cesium fluoride and to avoid the formation of large amounts of silicon tetrafluoride, glass may be used. This procedure has been used for preparation of up to 0.015 mole of CF2(0F)2 at a time with the aid of liquid nitrogen to condense excess fluorine into the vessel. The method is analogous to that used in the preparation of pentafluorosulfur hypofluorite by the static, catalytic fluorination of thionyl fluoride in the presence of cesium fluoride. ... 

Polymeric fluids are the most studied of all complex fluids. Their rich rheological behavior is deservedly the topic of numerous books and is much too vast a subject to be covered in detail here. We must therefore limit ourselves to an overview. The interested reader can obtain more thorough presentations in the following references a book by Ferry (1980), which concentrates on the linear viscoelasticity of polymeric fluids, a pair of books by Bird et al. (1987a,b), which cover polymer constitutive equations, molecular models, and elementary fluid mechanics, books by Tanner (1985), by Dealy and Wissbrun (1990), and by Baird and Dimitris (1995), which emphasize kinematics and polymer processing flows, a book by Macosko (1994) focusing on measurement methods and a book by Larson (1988) on polymer constitutive equations. Parts of this present chapter are condensed versions of material from Larson (1988). The static properties of flexible polymer molecules are discussed in Section 2.2.3 their chemistry is described in Flory (1953). 

Other vapor pressures for CoCl2(cr, t) have been measured by static ( ) and transpiration (5, 6) methods. In all three studies the presence of a small amount of dimer in the saturated vapor was not considered. JANAF pressures based on (a) selected values of the heats of sublimation and vaporization for the monomer and dimer, (b) the mass spectrometric value of 2A j H(monomer)- Agy H(dimer) - -38.99 kcal mol" (see Co2Cl (g) table) at 298.15 K, and (c) adopted entropies for the condensed and gaseous species are compared with the observed total pressures in the table given below. 

Molecular polarizabilities and hyperpolarizabilities are now routinely calculated in many computational packages and reported in publications that are not primarily concerned with these properties. Very often the calculated values are not likely to be of quantitative accuracy when compared with experimental data. One difficulty is that, except in the case of very small molecules, gas phase data is unobtainable and some allowance has to be made for the effect of the molecular environment in a condensed phase. Another is that the accurate determination of the nonlinear response functions requires that electron correlation should be treated accurately and this is not easy to achieve for the molecules that are of greatest interest. Very often the higher-level calculation is confined to zero frequency and the results scaled by using a less complete theory for the frequency dependence. Typically, ab initio studies use coupled-cluster methods for the static values scaled to frequencies where the effects are observable with time-dependent Hartree-Fock theory. Density functional methods require the introduction of specialized functions before they can cope with the hyperpolarizabilities and higher order magnetic effects. 

In conclusion we present various experimental schemes for overcoming dephasing, in order to study the intrinsic decoherence of BEC. Using some of these methods, we quantify nontrivial decoherence mechanisms both for weak excitations in BEC and in strongly excited condensates. We calculate the effects of a stronger inter-atomic interaction, namely, the appearance of a peak in the static structure factor of the system. Matter wave interference spectra are shown to be a highly sensitive probe of condensate response, with the sensitivity of this method approaching the few excitation limit. 

The most straightforward method for vapor-pressure measurement is the static method, in which the pressure of the vapor above a pure liquid is measured directly with a manometer, pressure gauge, or pressure transducer. All parts of the apparatus must be maintained at a temperature at least as high as that of the sample in order to avoid condensation. Static techniques may be used at high temperatures and pressures with appropriate apparatus construction, but they become difficult at low vapor pressures due to the difficulty of pressure measurement and the effects of impurities. With good equipment and procedures, the accuracy of static vapor pressure measurements can be on the order of 0.1%. 

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