Excess thermodynamic quantities of D2O water calculated from its Raman O−D stretching spectra

Open Physics ◽  
2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Mircho Georgiev ◽  
Nikolay Goutev ◽  
Zhorro Nickolov ◽  
Georgi Georgiev
Keyword(s):  
Melting Point ◽  
Excess Enthalpy ◽  
Excess Heat Capacity ◽  
Thermodynamic Quantities ◽  
Calorimetric Data ◽  
Good Correspondence ◽  
Excess Thermodynamic Quantities ◽  
Excess Thermodynamic Functions ◽  
Latent Heat Of Melting ◽  
Comparison Of The Results

AbstractExcess thermodynamic functions of D2O water have been calculated from the vibrationally decoupled O−D stretching spectra of very dilute solutions of HOD in H2O. Comparison of the results with reference calorimetric data for water showed a good correspondence for excess heat capacity above the melting point of ice. The excess enthalpy at the melting point also coincides well with latent heat of melting.

On Temperature Dependence of Excess Gibbs Energy

1999 ◽  
Vol 64 (7) ◽  
pp. 1093-1099 ◽  
Author(s):  
Ivona Malijevská ◽  
Anatol Malijevský
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Temperature Dependence ◽  
Excess Gibbs Energy ◽  
Excess Enthalpy ◽  
Excess Heat Capacity ◽  
Wilson Equation ◽  
Excess Heat ◽  
Energy Excess ◽  
Wilson And Nrtl Equations

Temperature dependence of GE is discussed for three widely used equations linear and nonlinear in parameters. It is shown that the Wilson equation predicts always positive excess heat capacity regardless of values of its parameters. Several temperature modifications of the Redlich-Kister, Wilson and NRTL equations are discussed with respect to the sign of the excess Gibbs energy, excess enthalpy and excess heat capacity.

scholarly journals Non-Specific Adsorption of Hydrocarbons on Microporous Surfaces: A Comprehensive Molecular-Statistical/Chromatographic Approach

1992 ◽  
Vol 9 (2) ◽  
pp. 54-71 ◽  
Author(s):  
E.V. Aksenenko ◽  
Yu. I. Tarasevich
Keyword(s):  
Statistical Methods ◽  
Computational Methods ◽  
Short Range ◽  
Statistical Approach ◽  
Adsorption Properties ◽  
Specific Adsorption ◽  
Thermodynamic Quantities ◽  
Good Correspondence ◽  
Symmetry Properties ◽  
Adsorption Systems

The results are presented of a series of investigations concerning the application of the molecular-statistical approach to the calculation of thermodynamic quantities for the adsorption of molecules in the Henry region on adsorbent surfaces possessing certain surface symmetry properties, and in particular for systems characterized by dispersion and polarization attraction and short-range atom-atom repulsion. Computational methods have been developed and the results for particular adsorption systems are presented with emphasis on the adsorption properties of layer silicates. Good correspondence between the calculated results and chromatographic data for a number of adsorbents strongly supports the view that the combination of chromatographic and molecular-statistical methods provides a powerful tool for the investigation of the structural and adsorption-selective characteristics of surface-porous adsorbents.

A DILATOMETRIC STUDY OF SOLID METHANOL-d

1956 ◽  
Vol 34 (9) ◽  
pp. 1243-1248 ◽  
Author(s):  
D. W. Davidson
Keyword(s):  
Melting Point ◽  
Molar Volume ◽  
The Other ◽  
Gradual Transition ◽  
Calorimetric Data ◽  
Volume Changes ◽  
First Order ◽  
Dilatometric Study

With isopentane as the dilatometric liquid, CH3OD was examined between 120 °K. and the melting point. There is evidence of two transitions within the solid: one, in the vicinity of 158 °K., appears to be a gradual transition, the other, at 163 °K., a first-order one. The corresponding molar volume changes are 0.04 and 0.43 ml. A further change of volume of 2.67 ml./mole occurs at the melting point. These results are compared with recent dilatometric results for CH3OH and discussed with reference to the available calorimetric data. The molar volume of CH3OD is slightly greater than that of CH3OH in both liquid and solid forms.

Thermodynamic Properties of Binary Liquid Acid–Base Mixtures

1975 ◽  
Vol 53 (9) ◽  
pp. 1258-1262 ◽  
Author(s):  
Horacio N. Sólimo ◽  
Roque Riggio ◽  
Franco Davolio ◽  
Miguel Katz
Keyword(s):  
Propionic Acid ◽  
Excess Volume ◽  
Excess Enthalpy ◽  
Refractive Indices ◽  
Molar Free Energy ◽  
Acid Base ◽  
Excess Viscosity ◽  
Binary Liquid ◽  
Free Energy Of Activation ◽  
Excess Thermodynamic Functions

Viscosities, densities, refractive indices, and enthalpies at 25 °C were determined for the systems: propionic acid + aniline (PA + A ), propionic acid + N,N-dimethylaniline (PA + DMA ), and propionic acid + pyridine (PA + P). From the experimental results the excess volume, excess viscosity, excess molar free energy of activation, and excess enthalpy were calculated. The deviations from ideality for the excess thermodynamic functions are more important for the systems PA + A and PA + P than for PA + DMA. There is evidence for complex formation between propionic acid and aniline in the following molar relation: 2CH3CH2COOH·C6H5NH2.

Specific heat below 3 °K, melting point, and melting heat of rubidium and cesium

1970 ◽  
Vol 48 (11) ◽  
pp. 1327-1339 ◽  
Author(s):  
Douglas L. Martin
Keyword(s):  
Thermal Analysis ◽  
Melting Point ◽  
Low Temperature ◽  
Specific Heat ◽  
Alkali Metals ◽  
Effective Masses ◽  
Debye Temperatures ◽  
Latent Heat Of Melting ◽  
Specific Heat Coefficient ◽  
Limiting Value

Specific heat measurements were made between 0.4 and 3.0 °K. For rubidium (nominal purity 99.9%, actual purity probably ~ 99.99%) the electronic specific heat coefficient γ is 624.6 ± 6.5 μcal/°K2 g atom and the low temperature limiting value of the Debye temperature (ΘOoc) is 56.5 ± 0.2 °K. For cesium (nominal purity 99.99%, actual purity probably ~ 99.97%) γ is 950 ± 20 μcal/°K2 g atom and ΘOoc is 40.5 ± 0.3 °K. These Debye temperatures are in fair agreement with ΘOoc1 values calculated from low temperature elastic constant measurements. Electron effective masses (calculated from γ) are 1.37 ± 0.01 for Rb and 1.80 ± 0.04 for Cs. Thermal effective masses for all the alkali metals are compared with recent theoretical results. Sample purities were checked by an independent spectrographic analysis and by making a thermal analysis in the melting region on the actual specific heat samples. These thermal analysis results led to a review of earlier work on the melting of these metals and the following revised values of melting point and latent heat of melting were obtained: Rb: 312.47 ± 0.02 °K, 524.3 ± 1.0 cal/g atom; Cs: 301.67 ± 0.13 °K, 501.0 ± 1.0 cal/g atom.

scholarly journals The age-stratified analytical model for the spread of the COVID-19 epidemic

2021 ◽  
Author(s):  
Felix Mairanowski ◽  
Denis Below
Keyword(s):  
Analytical Model ◽  
High Intensity ◽  
Age Groups ◽  
Observation Data ◽  
Age Group ◽  
Epidemic Spread ◽  
Intensity Of Infection ◽  
Good Correspondence ◽  
Contact Patterns ◽  
Comparison Of The Results

The previously developed ASILV model for calculating epidemic spread under conditions of lockdown and mass vaccination was modified to analyse the intensity of COVID-19 infection growth in the allocated age groups. Comparison of the results of calculations of the epidemic spread, as well as the values of the seven-day incidence values with the corresponding observation data, shows their good correspondence for each of the selected age groups. The greatest influence on the overall spread of the epidemic is in the 20-40 age groups. The relatively low level of vaccination and the high intensity of contact in these age groups contributes to the emergence of new waves of the epidemic, which is especially active when the virus mutates and the lockdown conditions are relaxed. The intensity of the epidemic in the 90+ age group has some peculiarities compared to other groups, which may be explained by differences in contact patterns among individuals in this age group compared to others. Approximate ratios for estimating mortality as a function of the intensity of infection for individual age groups are provided. The proposed stratified ASILV model by age group will allow more detailed and accurate prediction of the spread of the COVID-19 epidemic, including when new, more transmissible versions of the virus mutate and emerge.

scholarly journals Application of the Pippard Relations to Cyclohexane near the Melting Point

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Hamit Yurtseven
Keyword(s):  
Experimental Data ◽  
Melting Point ◽  
Organic Compound ◽  
Critical Exponent ◽  
Power Law ◽  
Thermal Expansivity ◽  
Second Order ◽  
Order Transition ◽  
Thermodynamic Quantities ◽  
Second Order Transition

The Pippard relations are verified near the melting point for cyclohexane. The experimental data for the thermal expansivity is analyzed according to a power-law formula using the critical exponent and the thermodynamic quantities are calculated close to the melting point for this molecular organic compound. This applies to those compounds showing a second order transition prior to melting.

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