Quantum Approach to Classical Thermodynamics and Optimization

2010 ◽  
pp. 1-20 ◽  
Author(s):  
R.D. Somma ◽  
G. Ortiz
Keyword(s):  
Quantum Approach ◽  
Classical Thermodynamics

General Cluster Sorption Isotherm

2020 ◽  
Author(s):  
Christoph Buttersack
Keyword(s):  
Density Functional ◽  
Capillary Condensation ◽  
Cluster Formation ◽  
Full Range ◽  
Full Description ◽  
Cross Sectional ◽  
Macroporous Silica ◽  
Isotherm Equation ◽  
Type Iv ◽  
Classical Thermodynamics

<p>Adsorption isotherms are an essential tool in chemical physics of surfaces. However, several approaches based on a different theoretical basis exist and for isotherms including capillary condensation existing approaches can fail. Here, a general isotherm equation is derived and applied to literature data both concerning type IV isotherms of argon and nitrogen in ordered mesoporous silica, and type II isotherms of disordered macroporous silica. The new isotherm covers the full range of partial pressure (10<sup>-6</sup> - 0.7). It relies firstly on the classical thermodynamics of cluster formation, secondly on a relationship defining the free energy during the increase of the cluster size. That equation replaces the Lennard-Jones potentials used in the classical density functional theory. The determination of surface areas is not possible by this isotherm because the cross-sectional area of a cluster is unknown. Based on the full description of type IV isotherms, most known isotherms are accessible by respective simplifications. </p>

Temperature and its measurement

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Thermal Equilibrium ◽  
Isotope Fractionation ◽  
Thermodynamic Temperature ◽  
The Other ◽  
Deterministic Models ◽  
Triple Point Of Water ◽  
Temperature Scales ◽  
Classical Thermodynamics ◽  
The Relationship ◽  
Unit Of Temperature

Temperature is that property of a body which determines whether it gains or loses energy in a particular environment. In classical thermodynamics temperature is defined by the relationship between energy and entropy. Temperature can be defined only for a body that is in thermodynamic and thermal equilibrium; whilst organisms do not conform to these criteria, the errors in assuming that they do are generally small. The Celsius and Fahrenheit temperature scales are arbitrary because they require two fixed points, one to define the zero and the other to set the scale. The thermodynamic (absolute) scale of temperature has a natural zero (absolute zero) and is defined by the triple point of water. Its unit of temperature is the Kelvin. The Celsius scale is convenient for much ecological and physiological work, but where temperature is included in statistical or deterministic models, only thermodynamic temperature should be used. Past temperatures can only be reconstructed with the use of proxies, the most important of which are based on isotope fractionation.

scholarly journals Modification of Type B Inclusions by Calcium Treatment in High-Carbon Hard-Wire Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 676
Author(s):  
Linzhu Wang ◽  
Zuobing Xi ◽  
Changrong Li
Keyword(s):  
Inclusion Size ◽  
Type B ◽  
Calcium Treatment ◽  
High Carbon ◽  
Fine Size ◽  
Dispersed Inclusions ◽  
Wire Steel ◽  
Classical Thermodynamics ◽  
The Relationship

To investigate the modification of type B inclusions in high-carbon hard-wire steel with Ca treatment, Si-Ca alloy was added to high-carbon hard-steel, and the composition, morphology, size, quantity, and distribution of inclusions were observed. The samples were investigated by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The experimental thermal results showed that the modification effect of inclusion was better in high-carbon hard-wire steel with Al of 0.0053% and Ca of 0.0029% than that in steel with Al of 0.011% and Ca of 0.0052%, in which the inclusions were mainly spherical semi-liquid and liquid CA2, CA, and C12A7. The inclusion size decreased from 3.2 μm to 2.1 μm. The degree of inclusions segregation was reduced in high-carbon hard-wire steels after calcium treatment. The results indicate that the modification of inclusions is conducive to obtaining dispersed inclusions with fine size. The ratio of length to width decreased and tended to be 1 with the increase in CaO content in the inclusion. When the content of CaO was higher than 30%, the aspect ratio was in the range of 1 to 1.2. The relationship between the activity of aluminum and calcium and the inclusions type at equilibrium in high-carbon hard-wire steel was estimated using classical thermodynamics. The calculated results were consistent with the experimental results. The thermodynamic software Factsage was used to analyze the effect of aluminum and calcium additions on the type and quality of inclusions in high-carbon hard-wire steels. The modification law and mechanism of type B inclusions in high-carbon hard-wire steels are discussed.

scholarly journals Quantum Euler Relation for Local Measurements

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 889
Author(s):  
Akram Touil ◽  
Kevin Weber ◽  
Sebastian Deffner
Keyword(s):  
Quantum Systems ◽  
Quantum Measurements ◽  
Weak Coupling Regime ◽  
Local Quantum ◽  
Dissipation Model ◽  
Local Measurements ◽  
Euler Relation ◽  
Quantum Analog ◽  
Back Action ◽  
Classical Thermodynamics

In classical thermodynamics the Euler relation is an expression for the internal energy as a sum of the products of canonical pairs of extensive and intensive variables. For quantum systems the situation is more intricate, since one has to account for the effects of the measurement back action. To this end, we derive a quantum analog of the Euler relation, which is governed by the information retrieved by local quantum measurements. The validity of the relation is demonstrated for the collective dissipation model, where we find that thermodynamic behavior is exhibited in the weak-coupling regime.

scholarly journals H. G. WELLS, GEOLOGY, AND THE RUINS OF TIME

2017 ◽  
Vol 45 (4) ◽  
pp. 839-855
Author(s):  
David Shackleton
Keyword(s):  
Physical Science ◽  
Evolutionary Biology ◽  
Narrative Structure ◽  
Time Machine ◽  
The Social ◽  
Social Discourses ◽  
Classical Thermodynamics

H. G. Wells's The Time Machine (1895) has hitherto been read in two principal scientific contexts: those of evolutionary biology and thermodynamic physics. Numerous critics have situated the romance in the context of evolutionary biology and contemporary discourses of degeneration (McLean 11–40; Greenslade 32–41). Others have discussed it in the context of thermodynamic physics. For instance, Bruce Clarke has read The Time Machine as “a virtual allegory of classical thermodynamics,” and shows that its combination of physical and social entropy reflects a wider transfer within the period of concepts and metaphors from physical science to social discourses of degeneration (121–26). Neatly linking these scientific contexts with issues of form, Michael Sayeau has argued that the social and physical entropy that are themes of the romance are reflected in its narrative structure, which manifests a type of narrative entropy, and thereby raises the spectre of the end of fiction (109–46).

Integrating Computational Chemistry into a Course in Classical Thermodynamics

2015 ◽  
Vol 92 (7) ◽  
pp. 1201-1203 ◽  
Author(s):  
Sheridan R. Martini ◽  
Cynthia J. Hartzell
Keyword(s):  
Computational Chemistry ◽  
Classical Thermodynamics
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