How Flexible Is the Concept of Local Thermodynamic Equilibrium?

It has been demonstrated by using generalized phenomenological irreversible thermodynamic theory (GPITT) that by replacing the conventional composition variables {xk} by the quantum level composition variables {x˜k,j} corresponding to the nonequilibrium population of the quantum states, the resultant description remains well within the local thermodynamic equilibrium (LTE) domain. The next attempt is to replace the quantum level composition variables by their respective macroscopic manifestations as variables. For example, these manifestations are, say, the observance of fluorescence and phosphorescence, existence of physical fluxes, and ability to register various spectra (microwave, IR, UV-VIS, ESR, NMR, etc.). This exercise results in a framework that resembles with the thermodynamics with internal variables (TIV), which too is obtained as a framework within the LTE domain. This TIV-type framework is easily transformed to an extended irreversible thermodynamics (EIT) type framework, which uses physical fluxes as additional variables. The GPITT in EIT version is also obtained well within the LTE domain. Thus, GPITT becomes a complete version of classical irreversible thermodynamics (CIT). It is demonstrated that LTE is much more flexible than what CIT impresses upon. This conclusion is based on the realization that the spatial uniformity for each tiny pocket (cell) of a spatially non-uniform system remains intact while developing GPITT and obviously in its other versions

Study of combustion of coal with magnegas as additive for improved combustion efficiency: A review of present scenario and future scope1) A combustion/deposition entrained reactor for high-temperature/pressure studies of coal and coal minerals The future

Articles you may be interested in Abstract. Fossil fuels are contributing the largest share in meeting up energy demands of urban lifestyle across the globe. May it be gasoline or coal, all sort of fossil fuels are drilled out of earth crust to burn on the earth surface creating huge burden on air quality. Incomplete combustion of fossil fuels cause pollution of carbon monoxide and other gases. It also eats away the breathable oxygen from atmosphere. Rampant use of coal in power sector causes above problems adding to the global warming phenomenon. Magnecules and magnehydrogen are seen to be best additives to fossil fuels which can effectively enhance the combustion efficiency of fossil fuels. Present paper discusses the enhancement in combustion efficiency of fossil fuels in terms of increased utility of carbon and improved quality of emission reducing the amount of obnoxious gases

Thermodynamic Stability Theories of Irreversible Processes and the Fourth Law of Thermodynamics

Three approaches for determining the thermodynamic stability of irreversible processes are described in generalized formulations. The simplest is the Gibbs–Duhem theory, specialized to irreversible trajectories, which uses the concept of virtual displacement in the reverse direction. Its only drawback is that even a trajectory leading to an explosion is identified as a thermodynamically stable motion. In the second approach, we use a thermodynamic Lyapunov function and its time rate from the Lyapunov thermodynamic stability theory (LTS, previously known as CTTSIP). In doing so, we demonstrate that the second differential of entropy, a frequently used Lyapunov function, is useful only for investigating the stability of equilibrium states. Nonequilibrium steady states do not qualify. Without using explicit perturbation coordinates, we further identify asymptotic thermodynamic stability and thermodynamic stability under constantly acting disturbances of unperturbed trajectories as well as of nonequilibrium steady states. The third approach is also based on the Lyapunov function from LTS, but here we additionally use the rates of perturbation coordinates, based on the Gibbs relations and without using their explicit expressions, to identify not only asymptotic thermodynamic stability but also thermodynamic stability under constantly acting disturbances. Only those trajectories leading to an infinite rate of entropy production (unstable states) are excluded from this conclusion. Finally, we use these findings to formulate the Fourth Law of thermodynamics based on the thermodynamic stability. It is a comprehensive statement covering all nonequilibrium trajectories, close to as well as far from equilibrium. Unlike previous suggested “fourth laws”, this one meets the same level of generality that is associated with the original zeroth to third laws. The above is illustrated using the Schlögl reaction with its multiple steady states in certain regions of operation

Unraveling the Solvation Behavior of Levocetirizine Dihydrochloride: Insights from Volumetric, Acoustic, Viscometric, and Electronic Absorption Studies in Aqueous l‑Proline and l‑Valine Solutions

The present article delves into the solvation behavior of levocetirizine dihydrochloride (LCTZ) in aqueous environments, thoroughly examining its interactions with two primary amino acids, l-proline and l-valine. This study spans the entire human body temperature range of 288.15–318.15 K, shedding light on the molecular dynamics and properties of LCTZ in the presence and absence of these amino acids. The investigation explores the volumetric, acoustic, viscometric, and electronic absorption properties of the system, along with extensive calculations of various thermodynamic and transport parameters of significance. The preponderance of hydrophobic associations of LCTZ with the water structure along with the dominant amino acid–LCTZ interaction surfaces out of the volumetric analysis, wherein viscometric and compressibility studies offer further support to the speculation. In the same vein, the sign of the temperature derivative of the B coefficient as well as that of Hepler’s constant underscores the chaotropic trait of studied molecules. The research thus contributes to a comprehensive understanding of intricate associations between LCTZ and the amino acids, unveiling the plausible intermolecular phenomenon for potential applications in drug delivery platforms. In this investigation, an attempt has been made to fill the gap in the existing literature, opening avenues for further research in this area