Evaluation of thermodynamic functions relative to cavity formation in liquids: uses and misuses of Scaled Particle Theory

1981 ◽  
Vol 59 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Nicole Morel-Desrosiers ◽  
Jean-Pierre Morel
Keyword(s):  
Experimental Data ◽  
Enthalpy Of Formation ◽  
Thermodynamic Functions ◽  
Enthalpy Of Vaporization ◽  
The Other ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Particle Theory ◽  
The Enthalpy Of Formation ◽  
Good Agreement

The Scaled Particle Theory (SPT) is probably the most powerful theory presently available, that enables the calculation of the thermodynamic functions relative to the formation of cavities in liquids. We give the general relationship between the enthalpy of vaporization and the enthalpy of formation of a molecular cavity in a pure normal liquid; the good agreement with the experimental data constitutes one of the strongest arguments justifying the application of SPT to real liquids. However, we show that SPT can lead to uncertain cavity terms if the molecular diameters of the studied liquids are not well-known. We compare, on the other hand, the cavity terms (G and H) calculated from Sinanoglu's theory, since this theory has been used to that end recently, with those obtained from SPT.

Entall - Thermodynamic Database of Alloys

2013 ◽  
Vol 58 (4) ◽  
pp. 1147-1148 ◽  
Author(s):  
A. Dębski
Keyword(s):  
Experimental Data ◽  
Thermodynamic Property ◽  
Enthalpy Of Formation ◽  
Thermodynamic Functions ◽  
Intermetallic Phases ◽  
Metal Alloy ◽  
Thermodynamic Database ◽  
Property Data ◽  
The Enthalpy Of Formation ◽  
Alloy Systems

Abstract Li-Si, Ag-Ca, B-Li, Ca-Li and Al-Li belong to the group of application alloys. The Entall database includes experimental data on the enthalpy of formation of the intermetallic phases belonging to the mentioned systems, as well as software for the calculation of other thermodynamic functions. The presented Entall database is the first proposal of a thermodynamic property data, which will be gradually extended by new metal alloy systems. It is a free database, available at www.entall.imim.pl.

scholarly journals Use of scaled-particle theory in the assessment of the Ph4As+/Ph4B− assumption for single ions

1979 ◽  
Vol 57 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael H. Abraham ◽  
Asadollah Nasehzadeh
Keyword(s):  
Free Energy ◽  
Recent Work ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Energy Term ◽  
Free Energies ◽  
Particle Theory ◽  
Novel Method ◽  
Energy Of Interaction ◽  
Solvent Molecules

A novel method for the assessment of the Ph4As+/Ph4B− assumption for free energies of transfer of single ions has recently been suggested by Treiner, and used by him to deduce that the assumption is not valid for transfers between water, propylene carbonate, sulpholane, dimethylsulphoxide, N-methyl-2-pyrrolidone, and perhaps also dimethylformamide. The basis of the method is the estimation of the free energy of cavity formation by scaled-particle theory, together with the hypothesis that the free energy of interaction of Ph4As+ (or Ph4B−) with solvent molecules is the same in all solvents, ΔGt0(int) = 0. It is shown in the present paper that (a) whether or not the Ph4As+/Ph4B− assumption applies to transfer to a given solvent depends on which other solvent is taken as the reference solvent in Treiner's method, (b) the calculation of the cavity free energy term by scaled-particle theory and by the theory of Sinanoglu – Reisse – Moura Ramos (SRMR) yields values so different that the method cannot be considered reliable, (c) the calculation of cavity enthalpies and entropies for Ph4As+ or Ph4B− by scaled-particle theory yields results that are chemically not reasonable, (d) the hypothesis that ΔGt0(int) = 0 conflicts with SRMR theory, and (e) the conclusions reached by Treiner are not in accord with recent work that in general supports the Ph4As+/Ph4B− assumption for solvents that are rejected by Treiner.

APPLICATION OF A NEW HAMILTONIAN OF INTERACTION TO THREE-DIMENSIONAL STRUCTURES

2004 ◽  
Vol 18 (09) ◽  
pp. 1351-1368
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Experimental Data ◽  
Cohesive Energy ◽  
Noble Gases ◽  
Three Dimensional ◽  
The Other ◽  
Ionic Crystals ◽  
Coupling Constant ◽  
Good Agreement

Using a new Hamiltonian of interaction we have calculated the cohesive energy in three-dimensional structures. We have found the news dependences of this energy on the distance between the atoms. The obtained results are in a good agreement with experimental data in ionic, covalent and noble gases crystals. The coupling constant γ between the interacting field and the atoms is somewhat smaller than unity in ionic crystals and is some larger than unity in covalent and noble gases crystals. The formulae found by us are general and may be applied, also, to the other types of interactions, for example, gravitational interactions.

Heat capacities and volumes of some non-electrolytes in N,N-dimethylformamide at 298.15 K

1987 ◽  
Vol 65 (12) ◽  
pp. 2810-2814 ◽  
Author(s):  
Henryk Piekarski
Keyword(s):  
Ethylene Glycol ◽  
Heat Capacities ◽  
Scaled Particle Theory ◽  
Partial Molal Volume ◽  
Cavity Formation ◽  
Particle Theory ◽  
Molal Volume ◽  
Analogous Data ◽  
Other Substances ◽  
Apparent Molal Heat Capacities

Heat capacities and densities of dilute solutions of formamide, acetone, tetrahydrofuran, ethylene glycol, 2-methoxyethanol, and 2-ethoxyethanol in N,N-dimethylformamide were determined at 298.15 K. Apparent molal heat capacities and volumes for these solutes in DMF were calculated and compared with the analogous data for other substances in DMF solution as well as with the data concerning solutions in methanol and water. Heat capacities of cavity formation (ΔCcav) in DMF were calculated on the basis of the Scaled Particle Theory. ΔCcav appeared to be linearly correlated with the standard partial molal volume of corresponding solutes in DMF. Similar dependences were also found for aqueous and methanolic solutions of the non-electrolytes.

Solubility of nonpolar gases in 2-methylcyclohexanone between 273.15 and 303.15 K at 101.32 kPa partial pressure of gas

1989 ◽  
Vol 67 (5) ◽  
pp. 809-811 ◽  
Author(s):  
Maria Asuncion Gallardo ◽  
Maria del Carmen Lopez ◽  
Jose Santiago Urieta ◽  
Celso Gutierrez Losa
Keyword(s):  
Partial Pressure ◽  
Thermodynamic Functions ◽  
Solution Process ◽  
Pair Potential ◽  
Scaled Particle Theory ◽  
Sphere Diameter ◽  
Gas Solubility ◽  
Particle Theory ◽  
Potential Parameters ◽  
Solubility Of Nonpolar Gases

Solubility measurements of several nonpolar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, CH4, C2H4, C2H6, CF4, SF6, and CO2) in 2-methylcyclohexanone at 273.15–303.15 K and a partial pressure of gas of 101.32 kPa are reported. Thermodynamic functions (Gibbs energy, enthalpy, and entropy) for the solution process at 298.15 K and 101.32 kPa partial pressure of gas are evaluated. Use is made of the Scaled Particle Theory applied to gas solubility for determining Lennard-Jones (6, 12) pair-potential parameters and temperature dependence of the effective hard-sphere diameter of the solvent. The values that this theory predicts for the solution thermodynamic functions are also calculated. Keywords: 2-methylcyclohexanone, gas solubility, thermodynamic functions of solution, Henry coefficient, scaled particle theory.

Numerical Simulation of Twin-Parachute Inflation Process for Aircraft Ejection Escape

2020 ◽  
Author(s):  
Liwu Wang ◽  
Mingzhang Tang ◽  
Sijun Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Model ◽  
Physical Models ◽  
The Other ◽  
Arbitrary Lagrangian Eulerian ◽  
Safe Distance ◽  
Structure Interaction ◽  
Parachute Inflation ◽  
Good Agreement

Abstract In order to study the safe distance between twin-parachute during their inflation process for fighter ejection escape, the fighter was equipped with two canopies and two seats, two types of parachute were used to numerically simulate their inflation process, respectively. One of them is C-9, the other a slot-parachute (S-P). Their physical models were built, then the meshes inside and around both parachutes were generated for fluid-structure interaction (FSI) simulation. The penalty function and the arbitrary Lagrangian-Eulerian (ALE) method were employed in the FSI simulation. To validate the numerical model for FSI simulation, at first the single parachute of the twin-parachute was used for the FSI simulation, the predicted inflation times for both types of parachute were compared with the experimental data. The computed results are in good agreement with experimental data. As a result, the inflation times were predicted with twin-parachute for both kinds of parachute. On the basis of the locations of ejected seats after the separation of seat and pilot, the initial locations and orientations of twin-parachute were also obtained. The numerical simulations for both kinds of parachute were performed by the FSI method, respectively. Our results illustrate that when the interval time for two seats ejected is greater than 0.25s, two pilots attached the twin-parachute are safe, and the twin-parachute would not interfere each other. Moreover, our results also indicate that the FSI simulation for twin-parachute inflation process is feasible for engineering applications and have a great potential for wide use.

Spektroskopische Untersuchungen, IX./Spectroscopic Investigations, IX.

1975 ◽  
Vol 30 (3-4) ◽  
pp. 259-262 ◽  
Author(s):  
Jürgen Martens ◽  
Klaus Praefcke ◽  
Helmut Schwarz
Keyword(s):  
Enthalpy Of Formation ◽  
Aromatic Compounds ◽  
Product Distribution ◽  
Mass Spectrometric ◽  
The Other ◽  
Spectrometric Investigation ◽  
Mass Spectrometric Investigation ◽  
Neutral Particles ◽  
Ortho Effect ◽  
The Enthalpy Of Formation

The mass-spectrometric investigation of esters and thiolesters of benzoic, thiobenzoic, salicylic and thiosalicylic esters shows that an analytical distinction with aid of the ortho effect is only possible under certain conditions between 1,2-disubstituted aromatic compounds and the other constitutional isomers. Absent or small intensive signals of rearrangement-ions do not exclude such a constitution. The apparent anomalous behaviour of the S-methyl, S-tolyl and O-tolyl esters is rationalized by energy considerations. The influence of the enthalpy of formation of the neutral particles on the product distribution (α-cleavage/ortho effect) is discussed.

EFFECT OF NON-MAGNETIC IMPURITIES (Zn, Li) ON THE STRIPED STATE OF A SPIN-FERMION MODEL FOR CUPRATES

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3610-3616
Author(s):  
A. Moreo
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
The Other ◽  
Hole Doping ◽  
Magnetic Impurities ◽  
High Tc ◽  
Fermion Model ◽  
Monte Carlo Techniques ◽  
High Tc Cuprates ◽  
Good Agreement

The presence of stripes and the effect of adding non-magnetic impurities (NMI), such as Zn or Li, to high-Tc cuprates is studied applying Monte Carlo techniques to a spin-fermion model. It is observed that adding Li is qualitatively similar to diping with equa percentages of Sr and Zn. The mobile holes (MH) are trapped by the NMI and the system remains insulating and commensurate with antiferromagnetic (AF) correlations. This behavior persists in the region % NMI >% MH . On the other hand, when % NMI <% MH magnetic and charge incommensurabilities are observed. The vertical or horizontal holerich stripes, present when % NMI =0 upon hole doping, are pinned by the impurities and tend to become diagonal, surrounding finite AF domains. The % MH -% NMI plane is investigated. Good agreement with experimental results is found in the small portion of this diagram where experimental data are available. Predictions about the expected behavior in the remaining regions are made.

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