Kinetic energy, pump system

Impingement separators, 246, 257 Chevron style, 248, 255 Efficiencies, 246 Knitted wire mesh, 246 York-vane efficiencies, 248 Inertial centrifugal separators, 266, 268 Kinetic energy, pump system, 187 Lamella plate classifiers, 239 Line sizing work sheet, 107... 

In actual experiments we do not usually observe directly the desorbed amount, but rather the derived read-out quantities, as is the time dependence of the pressure in most cases. In a closed system, this pressure is obviously a monotonously increasing function of time. In a flow or pumped system, the pressure-time dependence can exert a maximum, which is a function of the maximum desorption rate, but need not necessarily occur at the same time due to the effect of the pumping speed S. If there are particles on the surface which require different activation energies Ed for their desorption, several maxima (peaks) appear on the time curve of the recorded quantity reflecting the desorption process (total or partial pressure, weight loss). Thereby, the so-called desorption spectrum arises. It is naturally advantageous to evaluate the required kinetic parameters of the desorption processes from the primarily registered read-out curves, particularly from their maxima which are the best defined points. 

The result of a molecular dynamics simulation is a time dependent wavefunction (quantum dynamics) or a swarm of trajectories in a phase space (classical dynamics). To analyze what are the processes taking the place during photodissoeiation one can directly look at these. This analysis is, however, impractical for systems with a high dimensionality. We can calculate either (juantities in the time domain or in the energy domain, fn the time domain survival probabilities can be measured by pump-probe experiments [44], in the energy domain the distribution of the hydrogen kinetic energy can be experimentally obtained [8]. 

Spectroscopic observations confirm the existence of a vibrational temperature T = 2000 K greater than the translational one (Tg = 800 K) and show that NH is an important intermediate. The decomposition follows a zero order kinetics in analogy with the results reported in Sect. 4.2. Values of the rate constants are again several orders of magnitude larger than those observed in thermal decomposition and do not differ appreciably from those derived for hydrocarbons under similar discharge conditions. The reaction scheme is similar to that proposed in Sect. 4.2. The slow step involves the rupture of a N-H bond and the final step is NH + NH— N2 + H2. The presence of a mechanism of dissociation which makes use of the energy pumped into the vibrational manifold of NH3 has been invoked for this system as well. 

These reactions develop additional kinetic energy, which is converted into blanket heat. Most of the energy of the fusion process appears therefore in the hot blanket. If the blanket is in the form of molten lithium metal or salt, it can be pumped through a heat exchanger, which, in a the secondary circuit, produces steam for a turbine. Although the melting point of Li metal is only 186°C the Li temperature in the system will probably be around 1000°C. The tritium produced must be recovered for recycling as fuel. 

Two types of time resolved experiments can be carried out on such a system. The less ambiguous approach is that employed in the stilbene—He study (fig. 10.5) in which a second laser, time delayed from the pump laser, is used to excited the state. Smith and Knee (1993) have used picosecond time resolved TPES spectroscopy in which zero-energy electrons are collected as a function of the probe laser wavelength. [Laser based TPES has also been called zero kinetic energy (ZEKE) electron spectroscopy or pulsed field ionization (PFI) (Muller-Dethlefs and Schlag, 1991)]. Figure... 

Hydraulic power systems include both hydroelectric and pumped storage hydroelectric plants. In both cases, water is directed from a dam through a series of tapering pipes to rotate turbines and create electricity. In principle, the potential energy held in the dam converts into kinetic energy when it flows through the pipes (Fig. 3.23). 

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