Adiabatic

The current legislation imposes tighter restrictions in order to reduce the impact of chemical process industry on the environment. In this context, this study presents the dynamic model, simulation and optimization results for an industrial sulfuric acid plant. The dynamic model, implemented in PSE gPROMS includes a catalytic reactor (five pass converter), heat exchangers such as economizers and feed-effluent heat exchangers, mixers, splitters and reactive absorption columns. The kinetic parameters were fitted to the real plant data, while the remaining model parameters were estimated using classical correlations. The modeling results agree very well with the real plant data.The model implemented in gPROMS is useful for evaluating the dynamic behavior of the plant and for minimization of the total amount of SOx emissions. The SOx emissions could be significantly reduced by over 40% by optimizing operating parameters such as air feed flow rates or split fractions. However, only minor increases in energy production can be achieved due to the plant already operating near full capacity. The simulations also show that operational problems may occur when the process is disturbed due to production rate changes or catalyst deactivation, the non-linear response of the plant leading to sustained oscillations. Besides controllability, operability and optimization studies the gPROMS plant model is also useful for operator training and various scenario assessments.

In this paper we find a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules, composing an ideal gas. In such a gas, the motion of each individual molecule can be considered independently on all other molecules, and thus the macroscopic parameters of ideal gas, like pressure P and temperature T, can be introduced as a result of simple averaging over all individual motions of molecules. It is shown that for an ideal gas enclosed in a macroscopic cubic box of volume V, the constant, in the classical law of adiabatic expansion, i.e. PV^5/3=const, can be derived, based on quantum mechanics. Physical implications of the result we disclose are discussed. In any case, our finding proves, seemingly for the first time, a macroscopic manifestation of a quantum mechanical behavior, and this in relation to classical thermodynamics. (https://arxiv.org/abs/0805.4494)

This article mainly consists in the quantum mechanical study of an adiabatically compressed particle, in an infinitely high well, which we conjecture, can be considered as the basis of an ideal gas. Thus we prove that, all the compression energy is, as may be expected, transformed into extra kinetic energy of the particle. This result frames a quantum mechanical definition

In this paper, a connection between the long lasting macroscopic classical laws of gases and the quantum mechanical description of non-interacting particles confined in a box was found, thus constituting an ideal gas. In such a gas, the motion of each individual molecule can be considered to be independent of all other molecules, and the macroscopic parameters of an ideal gas, mainly, pressure P and temperature T, can be defined as simple average quantities based on individual motions of all molecules in consideration. It is shown that for an ideal gas enclosed in a macroscopic box of volume V, the constant γ γ γ γ appearing in the classical law of adiabatic expansion law, that is, t cons PV tan = γ , can be derived based on quantum mechanics. Physical implications of the result we disclose are discussed.

In this paper we find a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules, composing an ideal gas. In such a gas, the motion of each individual molecule can be considered independently on all other molecules, and thus the macroscopic parameters of ideal gas, like pressure P and temperature T, can be introduced

The present scope of work deals with a novel low power logic. We have demonstrated a new adiabatic switching logic. This new logic has good power and speed performance. This is known as 2-phase drive adiabatic logic. It is dynamic energy recovery logic and can have only evaluation and hold phases. The simulations have been done in Cadence design tools. The power dissipation and propagation delays have been estimated and compared with conventional adiabatic dynamic logic. Moreover, energy saving factor and power-delay product have also been estimated. Behavior of 2PADCL has been examined with the help of 2PADCL based adder. The comparison results with the variation of frequency, voltage and temperature have been presented.

The nonlinear behavior of the heat-integrated plug-flow reactor, consisting of a feed-effluent heat exchanger (FEHE), furnace, adiabatic tubular reactor, and steam generator is studied, considering a first-order, irreversible, exothermic, adiabatic reaction. Bifurcation theory is used to analyze the relationships among design, reaction thermodynamics and kinetics, and state multiplicity and stability. Hysteresis, isola and boundary-limit varieties are computed, and the influence of the activation energy, reaction heat and FEHE efficiency on the multiplicity region is studied. The double-Hopf and double-zero bifurcation points divide parameter space in regions with different dynamic behavior. State multiplicity, isolated branches, and oscillatory behavior may occur for realistic values of model parameters. A design procedure is proposed to ensure a desired multiplicity pattern and a stable point of operation and to avoid high sensitivity. The procedure was applied to three reaction systems with different kinetic and thermodynamic characteristics.

Abstract—Working with low frequency Universal Charge Recovery Logic (CRL) based NAND gate given in [1], the leakage current results in gradual charge up of the output node resulting in an incorrect output. A better implementation of the same circuit which increases the ...

The present scope of work deals with a novel low power logic. We have demonstrated a new adiabatic switching logic. This new logic has good power and speed performance. This is known as 2-phase drive adiabatic logic. It is dynamic energy recovery logic and can have only evaluation and hold phases. The simulations have been done in Cadence design tools. The power dissipation and propagation delays have been estimated and compared with conventional adiabatic dynamic logic. Moreover, energy saving factor and power-delay product have also been estimated. Behavior of 2PADCL has been examined with the help of 2PADCL based adder. The comparison results with the variation of frequency, voltage and temperature have been presented.

This article mainly consists in the quantum mechanical study of an adiabatically compressed particle, in an infinitely high well, which we conjecture, can be considered as the basis of an ideal gas. Thus we prove that, all the compression energy is, as may be expected, transformed into extra kinetic energy of the particle. This result frames a quantum mechanical definition of an ideal gas. It further helps the elucidation of a paradox. (http://arxiv.org/abs/0902.2636)

Previously, we established a connection between the macroscopic classical laws of gases and the quantum mechanical description of molecules of an ideal gas (T. Yarman et al. arXiv:0805.4494). In such a gas, the motion of each molecule can be considered independently on all other molecules, and thus the macroscopic parameters of the ideal gas, like pressure P and temperature T, can be introduced as a result of simple averaging over all individual motions of the molecules. It was shown that for an ideal gas enclosed in a macroscopic cubic box of volume V, the constant, arising along with the classical law of adiabatic expansion, i.e. PV5/3=constant, can be explicitly derived based on quantum mechanics, so that the constant comes to be proportional to h^2/m; here h is the Planck Constant, and m is the relativistic mass of the molecule the gas is made of. In this article we show that the same holds for a photon gas, although the related setup is quite different than the previous ideal gas setup. At any rate, we come out with PV5/3 hc=constant, where c is the speed of light. No matter what the dimensions of the constants in question are different from each other, they are still rooted to universal constants, more specifically to h2 and to hc, respectively; their ratio, i.e. V1/3 h/mc, interestingly pointing to the de Broglie relationship's cast. Comment: 7 pages (http://arxiv.org/abs/0906.1045)