Thermodynamic cycle development

Weber, B.H. and Deacon (2000). Thermodynamic cycles, development systems and emergence. Cybem. Hum. Know., 7 (1), 21-43... 

Ionic lattice energies are measured experimentally by means of a thermodynamic cycle developed by Max Born and Fritz Haber. The Born-Haber cycle is an application of Hess s law (the first law of thermodynamics). It is illustrated by a determination of the lattice energy of sodium chloride, which is A for the reaction... 

Active carbons can be used in both refrigeration and heat pumping cycles, but their potential for use in these applications does not necessarily merit the development of such systems. Before devoting research and development effort into active carbon-based thermodynamic cycles, the interest in both heat-driven cycles in general, and adsorption cycles in particular, must be justified. 

The horizontal line at the bottom of the pressure-volume diagram of Figure 4 traces the other tv o strokes of the four-stroke cycle. On the exhaust stroke, from 5 to 6, the rising piston expels most of the remaining combustion products from the cylinder. On the intake stroke, from 6 to 7 (= 1), the descending piston inducts a fresh charge for repetition of the cycle. The net thermodynamic work developed in this cycle is proportional to the area enclosed by the pressure-volume diagram. In the ideal case, both the exhaust and intake strokes occur at atmospheric pressure, so they have no effect on the net output work. That justifies their exclusion from the thermodynamic representation of the ideal Otto... 

Since electrostatic effects dominate the thermodynamic cycle as shown in Figure 10-2, major development efforts have focused on the calculation of electrostatic energy for transferring the neutral and charged forms of the ionizable group from water with dielectric constant of about 80 to the protein with a low dielectric constant (see later discussions). This led to the development of continuum based models, where water and protein are described as uniform dielectric media, and enter into the linearized Poisson-Boltzmann (PB) electrostatic equation,... 

The operative concept is essentially based on the relationship between work and energy, and accounts for the reversibility of processes in thermodynamic cycles (in relation to the development of thermal engines in the 19th century, or steam age cf Kittel, 1989). 

What are the choices for chemical propulsion in this century — an engine operating on a totally different fuel, one operating on a different thermodynamic cycle, or a combination of both Of course, the choice depends upon the application. It is worthwhile to develop a new concept of engines, ensure there are no show stoppers, identify the issues, select appropriate approaches to solve the issues, and establish the fundamental understanding needed to develop the concept into a practical engine. 

For such unstable carbocations, an alternative approach to pAR can be developed, by recognizing the relationship that exists between pATR and pAa implied in Equation (15) (p. 30). For carbocations with [3-hydrogen atoms, loss of a proton normally yields an alkene. Then, as discussed by Richard, pATR and pAa form two arms of a thermodynamic cycle, of which the third is the equilibrium constant for hydration of the alkene, pAH2o, as already indicated in Scheme 1. The relationship between these equilibrium constants is shown for the t-butyl cation in Scheme 4. In the scheme the equilibria are... 

The increasing industrial applications for adsorption have stimulated a growing interest in research. The research has been advancing on several fronts thermodynamics of adsorption (particularly statistical mechanics), diffusion of pores, PSA simulation, new process and cycle development, sorbent characterization, and development of new sorbents. Significant advances have been made on all fronts during the last decade. 

For influence on a temperature range (its expansion or compression) and improvements of efficiency binary heat machines (on two hydrides) have been modified for operation in multistage modes (triple heat pumps). The choice of three of hydrides and an estimation of efficiency of thermodynamic cycles for such HHP can be determined, basing on the approaches developed in [13, 14]. 

It is impractical to calculate the complete thermodynamic cycle for the formation of self-assembled molecular systems of the size and complexity of those discussed in this review. Methods that mutate the system from one kind to another are not applicable to such large systems [134]. Surrogates for relative stabilities, therefore, must be developed. Two such methods that we have developed are the following. 

A new acidity scale has been developed based on calorimetric measurement of A-methylimidazole and A-methylpyrrole in bulk solvents.A revised version of this method was shown to give better results in some cases.Another scale of solvent acidities was developed based on the hydrogen-bond donor acidities in aqueous DMSO. It is noted that bond energies, acidities, and electron affinities are related in a thermodynamic cycle, and Kass and Fattahi have shown that by measuring two of these quantities the third can be found. " ... 

The first step in cycle development is to determine its thermodynamic feasibility. The free energies and the enthalpies for the reactions shown in the above Table were obtained by using HSC Chemistry 5.11 which contain a thermodynamic database. At the temperature indicated in the table, based on cycle stoichiometry to produce 1 mol of hydrogen, the free energy change of each reaction step is 10 kcal, except for the electrochemical step, which has AG of 14.50 kcal/mol at 30°C. The current research of... 

An engine that utilizes a more efficient thermodynamic cycle of operation that consumes less fuel and is simple and capable of operation at both subsonic and supersonic speeds would be an attractive alternative for future propulsion systems. Pulse Detonation Engines (PDE), in principle, can provide higher efficiency [5] and better performance over a wide range of operating conditions, with fewer moving parts. The following seven fundamental issues in the development of PDEs have been identified [6] ... 

Further developments of these ideas took place in computational structural biology, where nonphysical local transformations were implemented within the framework of thermodynamic cycles. These nonphysical transformations were introduced in 1981 by Warshel, who studied ionization in acidic residues in proteins pK calculations). Although the cycle included nonphysical transformations, they were not carried out by the perturbation technique. A year later Warshel used the perturbation method together with umbrella sampling to study the solvation free energy contribution to an electron transfer reaction coordinate, using two spheres for donor and acceptor in water the perturbation, however, was performed along a physical path. Warshel also modeled some enzymatic reactions that involve nonphysical processes. ... 

A.A. Tager [110] determined the change of AG k by producing thermodynamic cycles using static sorption of solvent vapors on the polymeric specimens. However, in solution the polymer compatibihty is influenced by the difference of the thermodynamic interaction parameters of the common solvent with each indvidual polymer. Additionally, compatibility in solution does not always correspond to that in the solid state (without a solvent). These shortcomings limit the applicability of the AG ix estimation method that Tager developed. 

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