Low-pressure regime

As data of the binary diflfiision coefficient Dam(P> tne not available in many cases, one has to resort to taking the solvent self-diflfiision coefficient Dy p,T) which requires rescaling in the low-pressure regime according to... 

Equation (A3.13.54) legitimates the use of this semi-classical approximation of the molecule-field interaction in the low-pressure regime. Since /7j(t) is explicitly time dependent, the time evolution operator is more... 

Figure 4.15. Shock pressure versus specific volume for calcia and fused quartz indicating three regimes fused quartz, low-pressure regime is fused quartz, mixed phase regime, and high-pressure regime representing stishovite. In the case of calcia, the low-pressure phase is the B1 structure, mixed phase is indicated, and the high-pressure phase regime is in the B2 structure.

The density-pressure relationship for powder compaction at room temperature typically increases from the apparent density at zero pressnre to values that approach the theoretical density at high pressures, as illustrated in Figure 7.16. A compact with 100% theoretical density would indicate that it contains no porosity. Soft powders are more easily densified than hard powders at a given pressnre, and irregularly shaped powders have lower densities than spherical powders in the low-pressure regime. 

The dissociation of larger molecules such as benzene (C6H6) is often at the high-pressure limit, even at atmospheric pressure, whereas small molecules remain in the low-pressure regime at comparatively high pressures. 

The upper pressure limit of the Low-Pressure regime is estimated around 10-15 Torr, because it corresponds to the pressure for which one may observe... 

LP-CVD ZnO In contrast to AP-CVD processes, LP-CVD processes are kinetically limited, i.e., the growth rate of the film depends mainly on the rate of reactions at the growing surface. These reactions become the limiting factor, because the transport time necessary to carry the reactant from the gas inlet to the growing surface is strongly reduced by choosing the low pressure regime. 

High resolution studies by conventional spectroscopy are genuinely hampered by Doppler-broadening of the rotation-vibration lines in the low pressure regime. Individual Doppler-shifted frequencies contribute to the (normalized) Doppler-broadened line shape, due to the distribution of molecular velocities along the direction of observation... 

Figure 15.29 Effect of anode magnetron on the breakdown voltage of DC discharge of Ar in low-pressure regime.

The primary glow discharge reactor in this configuration could be used for plasma coating in a low-pressure regime, in principle however, in consideration of flow pattern in such a multiple shelves reactor and electrical field in multiple electrodes, it is difficult to achieve uniform coatings in such a mode of operation. 

This ester resembles its methyl homologue in possessing three modes of decomposition [131]. It also supports a self-decomposition flame, the multiple reaction zones of which are clearly separated at low pressures [122, 123, 125]. Temperature and composition profiles in the low-pressure decomposition flame have been measured [133]. The products include formaldehyde, acetaldehyde and ethanol with smaller amounts of methane and nitromethane. The activation energy derived from the variation of flame speed with final flame temperature was 38 kcal. mole", close to the dissociation energy of the RO—NO2 bond. The controlling reaction is believed to be unimolecular in its low pressure regime, and the rate coefficient calculated from the heat-release profile is... 

III the limiting low-pressure regime, a mixed-order rate law is expected, viz. 

The detailed kinetics and energetics of the reactions in the rf-ion trap can be understood by considering that the total pressure inside the ion trap is on the order of 1 Pa, which means that the experiment is operating in the kinetic low-pressure regime. Therefore, a Lindemann-t3rpe mechanism has to be considered for each reaction step, and the reaction rates depend on the buffer gas pressure [187, 188]. As a consequence, the obtained pseudo first order rate constant k contains the termolecular rate constant as well as the concentrations of the helium buffer gas and of the reactants in the case of the adsorption reaction of the first CO molecule (1.1) ... 

As the experiment is operating in the kinetic low-pressure regime, the decomposition rate constant can consequently be considered to be much larger than the stabilization rate constant term k fcs[He]. This leads to a simplified expression for the termolecular rate constant, which can be applied to the experimental conditions present in the ion trap experiment... 

At high pressures, sulfur undergoes several phase transitions towards close-packing. In the low pressure regime (<20 GPa), the phase transitions observed by Raman and X-ray studies are complicated due to photo-induced transformations which have to be attributed to the pressure-tuned red-shift of the optical edge of sulfur. At higher pressures (around 90 GPa), metallization and superconducting states have been observed. 

A versatile route for the gas-phase synthesis of various gold(I) complexes is provided by the reaction of Au+ with hexafluorobenzene. While IE F ) = 9.91 eV is large enough to prevent ET, C6F6 has a sufficient number of rovibronic states to allow for efficient formation of the Au(C6F6)+ complex via radiative stabilization in the low-pressure regime according to Reaction (7.5) (Schroder et al. 1995) ... 

The experiments were carried out in small stainless steel autoclaves having an internal volume of 700 mL. The autoclaves, having been charged with a particular catalyst solution and gas mixture of interest, were mounted vertically in electrically heated ovens. The factors affecting the rate of the reaction are partial pressure of carbon monoxide, partial pressure of ethylene, catalyst concentration, temperature, base concentration/pH, and the nature of the base. Carbon monoxide has an inhibitory effect upon the reaction. The rate of reaction increases linearly with ethylene pressure in the low-pressure regime but exhibits saturation at ethylene pressures exceeding 17 atm. The reaction is second order with respect to catalyst concentration. The nature of the base used deter-... 

A high-density decoupled plasma is most important to make this approach work, first to achieve sufficient sidewall passivation in a comparatively low-pressure regime, second to obtain a high fluorine concentration and thus high etch rates, and third to achieve a low plasma potential, close to ground potential. With a plasma potential close to ground, ion energy flow to the wafer surface is con-... 

The relative affinity series 24 was found for bare Au+ ions binding with various molecules M, to yield complex ions [AuM]+. This took place in the low-pressure regime of a Fourier transform ion cyclotron resonance MS. The absolute bond dissociation energies were evaluated by means of ab initio MO calculations at the MP2 level of theory255. 

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