Minimum energy requirements

The work fiinction (di) is defined as the minimum work that has to be done to remove an electron from tlie bulk of the material to a sufficient distance outside the surface such that it no longer experiences an interaction with the surface electrostatic field [43, 44 and 45]. In other words, it is the minimum energy required to remove an electron from the... 

Faraday s law states that 96,487 coulombs (1 C = 1 A-s) are required to produce one gram equivalent weight of the electrochemical reaction product. This relationship determines the minimum energy requirement for chlorine and caustic production in terms of kiloampere hours per ton of CI2 or NaOH... 

This ty pe of cavitation is also called inadequate NPSHa cavitation. To prevent this ty pe of cavitation, the NPSHa in the system (the available energ) in the system), must be higher than the NPSHr of the pump (the pump s minimum energy requirement). 

For a spark to be felt, it must have an energy of at least 1 mJ. The minimum energy required to ignite a flammable mixture is 0.2 mJ, so a spark that can be felt is certainly capable of causing ignition if flammable vapor is present. 

Sufficient to cause damage to process equipment Minimum energy required to ignite wood at indefinitely long exposures... 

Minimum energy required for piloted ignition of wood, melting of plastic tubing... 

What is the minimum energy required to synthesize one mole of nitric oxide, NO, from the elements ... 

The work function, O, of a solid surface (in eV) is the minimum energy required to extract an electron from that (neutral) surface.9 10,16 23 The parameter O/e (in V) is usually called the extraction potential. 

In terms of the two-phase system which comprises dispersions of solids in liquids, the minimum energy requirement is met if the total interfacial energy of the system has been minimized. If this requirement has been met, chemically, the fine state of subdivision is the most stable state, and the dispersion will thus avoid changing physically with time, except for the tendency to settle manifest by all dispersions whose phases have different densities. A suspension can be stable and yet undergo sedimentation, if a true equilibrium exists at the solid-liquid interface. If sedimentation were to be cited as evidence of instability, no dispersion would fit the requirements except by accident—e.g., if densities of the phases were identical, or if the dispersed particles were sufficiently small to be buoyed up by Brownian movement. 

Activation energy The minimum energy required to start a chemical reaction. 

Quanta The plural of quantum. It is the minimum energy required to change certain properties such as the energy of an electron in an atom. 

The appearance potential (AP) of an ion refers to the experimentally determined minimum energy required to produce that specific ion from the ground state of the neutral atom. The appearance potentials of ions of specific types, such as the fragment ions, have been listed by Franklin et al. (1969). Some common appearance potentials of ions are given in Table 4.2. 

We have already mentioned the threshold behavior of photodetachment. Morrison (1957) postulated the rule that at or near threshold, the cross section for a process should vary as cr°c( - ) , where is the energy transferred, 0 is the minimum energy required for the process, and n equals the number of outgoing electrons minus 1. Thus, as shown schematically in Figure 4.4, the threshold cross section should vary linearly with energy for... 

Figure 2.73(a) shows the X-ray absorption spectrum of copper. The K edge is the minimum energy required to ionise an electron from the Is orbital ... 

The energy barrier E t is the minimum energy requirement for reaction. If only this amount of energy is available, only one orientation out of all the possible collision orientations is successful. The probability of success rises rapidly if extra energy is... 

To remove any possible confusion, we further refine the definition of ionization energy, and say that 7 is the minimum energy required to ionize 1 mol of a gaseous element. The ionization energy 7 relates to process (2) process (1) is additional. 

Minimum Energy Requirements. Except for bolting materials, the applicable minimum energy requirements for carbon and low alloy steels with specified minimum tensile strengths less than 656 MPa (95 ksi) shall be those shown in Table GR-2.1.3(e). 

A—flic free energy is the minimum energy required for a non-spontaneous reaction and the maximum energy available for a spontaneous reaction. 

The adiabatic ionization energy of any molecule AB (mono-, di-, or polyatomic), represented by ) (AB), is the minimum energy required to remove an electron from the isolated molecule at 0 K ... 

The appearance energy (formerly known as appearance potential) is a widely used concept in threshold mass spectrometry experiments, which involve measuring the minimum energy required to cause a certain process. However, there are a number of theoretical and practical problems associated with the determination of reliable values of H o(A+/AB). In the following paragraphs we summarize the discussion of this subject made by the groups of Traeger for photoionization [64,65] and Holmes for electron impact [66]. 

The use of these expressions is effectual only in cases where there is no extensive deviation in the system behavior due to charge transfer overpotential or other kinetic effects.(l) The calculated threshold or thermodynamic energy requirement (2 ) (AG in the previous equation) is often much lower than actually encountered, but is still useful in estimating an approximate or theoretical minimum energy required for electrolysis. Part of the difficulty in applying thermodynamics to many systems of industrial interest may reside in an inability to properly define the activities or nature of the various species involved in the... 

The minimum energy requirement for treating separated pig slurry to control odour was 110 Wh pig place-1 day-1, assuming an aerator efficiency of 1kg 02/kWh input. 

Since Eo, the minimum energy required for E in order to react, is usually quite large compared to the vibrational spacing in the reactant, the spacing between the active levels in A is small and it makes sense to employ the density of states function p(Ev ) for A (i.e. instead of attempting to sum discrete individual states). For... 

Q2 is the partition function for molecules with energy larger than Eo, the minimum energy required for reaction. 

The orientation of water molecules at the interface is an important ingredient in understanding the properties of the surface region. A large body of data is available on the stmcture of water at metal surfaces measured under ultrahigh vacuum (UHV) conditions, but it is expected that the orientation of water molecules under the conditions that exist at the electrode/electrolyte interface is very different. As mentioned earlier, the fact that the minimum energy required to eject an electron from the surface (the work function) is lower when the metal is in contact with water... 

The ionization energy (IE) defines the minimum energy required for ionization of the neutral concerned. Most molecules have lEs in the 7-15 eV range (Chap. 2.2, Tab. 2.1). If an impacting electron carrying just an amount of energy equal to IE would quantitatively transfer it when colliding with the neutral, ionization would... 

Table 1. Minimum energy requirements for each arrangement, Btu/h...

Obviously, no solvent satisfies all these requirements, and the selection of a desirable solvent involves a compromise between these and other factors. When a preliminary selection has been made, a secondary screening can be performed based on simplified calculations of minimum energy requirement, since the capital costs for similar process configurations will not vary too much. 

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