Concentration and temperature dependence of heats of mixing of 1-butanol, 2-butanol, and 2-methyl-2-propanol with cyclohexane

1983 ◽  
Vol 48 (12) ◽  
pp. 3482-3494 ◽  
Author(s):  
František Veselý ◽  
Vladimír Dohnal ◽  
Miriam Valentová ◽  
Jiří Pick
Keyword(s):  
Entire Range ◽  
Experimental Error ◽  
Binary Systems ◽  
Enthalpy Of Mixing ◽  
Excess Enthalpies ◽  
Heats Of Mixing ◽  
Maximum Value ◽  
Concentration Dependences ◽  
System 2 ◽  
Isothermal Calorimeter

The concentration dependences of excess enthalpies were measured in an isothermal calorimeter within the range of 25-50 °C at six temperatures for the binary systems 1-butanol-cyclohexane and 2-butanol-cyclohexane and at five temperatures for the system 2-methyl-2-propanol-cyclohexane. A conspicuous temperature and concentration dependence of the maximum value of enthalpy of mixing was found for the latter system. Heats of mixing of all three systems were correlated by the SSF equation. The results of correlation are comparable with the experimental error (0.5%) in the entire range of mole fractions of alcohols.

Heats of mixing of cyclohexane with 1-propanol and 2-propanol

1979 ◽  
Vol 44 (10) ◽  
pp. 2869-2881 ◽  
Author(s):  
František Veselý ◽  
Petr Uchytil ◽  
Milan Zábranský ◽  
Jiří Pick
Keyword(s):  
Interaction Parameter ◽  
Binary Systems ◽  
Specific Interaction ◽  
Quantitative Description ◽  
Quantitative Character ◽  
Heats Of Mixing ◽  
Excess Gibbs Energies ◽  
Concentration Dependences ◽  
Temperature Dependences ◽  
Isothermal Calorimeter

The concentration dependences of excess enthalpies of the binary systems cyclohexane-1-propanol and cyclohexane-2-propanol were measured in an isothermal calorimeter at six temperatures in the range of 25-50°C. For the quantitative description of the concentration and temperature dependences of heats of mixing, the Liebermann-Wilhelm model of associated solution was used extended by the assumption of polynomial temperature dependence of the interaction parameter. It follows from the comparison of chemical and physical contribution to the excess enthalpy that heats of mixing in the system with 1-propanol are given mostly by a specific interaction of hydrogen bond. The excess Gibbs energies were estimated using an interaction parameter calculated from heats of mixing. The values obtained are systematically higher and have rather semi-quantitative character.

Heats of mixing of butanone and chloroform with alkanes: Binary systems

1978 ◽  
Vol 43 (3) ◽  
pp. 829-836 ◽  
Author(s):  
Ján Biroš ◽  
Antonín Živný ◽  
Julius Pouchlý
Keyword(s):  
Binary Systems ◽  
Heats Of Mixing

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Concentration Dependence ◽  
Experimental Error ◽  
Binary Systems ◽  
Experimental Studies ◽  
Study Results ◽  
Component Systems ◽  
Minimum Depth ◽  
Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

scholarly journals Difficulties in parentage analysis: the probability that an offspring and parent have the same heterozygous genotype

2001 ◽  
Vol 78 (2) ◽  
pp. 163-170 ◽  
Author(s):  
A. C. FIUMERA ◽  
M. A. ASMUSSEN
Keyword(s):  
Random Mating ◽  
Parentage Analysis ◽  
Mixed Mating ◽  
Heterozygous Genotype ◽  
Heterozygous Parent ◽  
Mendelian Segregation ◽  
Maximum Value ◽  
Potential Applicability ◽  
System 2 ◽  
Increasing Function

Parentage studies often estimate the number of parents contributing to half-sib progeny arrays by counting the number of alleles attributed to unshared parents. This approach is compromised when an offspring has the same heterozygous genotype as the shared parent, for then the contribution of the unshared parent cannot be unambiguously deduced. To determine how often such cases occur, formulae for co-dominant markers with n alleles are derived here for Ph, the probability that a given heterozygous parent has an offspring with the same heterozygous genotype, and Pa, the probability that a randomly chosen offspring has the same heterozygous genotype as the shared parent. These formulae have been derived assuming Mendelian segregation with either (1) an arbitrary mating system, (2) random mating or (3) mixed mating. The maximum value of Pa under random mating is 0·25 and occurs with any two alleles each at a frequency of 0·5. The behaviour with partial selfing (where reproduction is by selfing with probability s, and random mating otherwise) is more complex. For n [les ] 3 alleles, the maximum value of Pa occurs with any two alleles each at a frequency of 0·5 if s < 0·25, and with three equally frequent alleles otherwise. Numerically, the maximum value of Pa for n [ges ] 4 alleles occurs with n* [les ] n alleles at equal frequencies, where the maximizing number of alleles n* is an increasing function of the selfing rate. Analytically, the maximum occurs with all n alleles present and equally frequent if s [ges ] 2/3. In addition, the potential applicability of these formulae for evolutionary studies is briefly discussed.

Manifestation of Сoncentration Quenching of Fluoroaluminate Glasses Doped with Erbium

2019 ◽  
Vol 822 ◽  
pp. 871-877
Author(s):  
Victor Klinkov ◽  
Aleksander Semencha ◽  
Evgenia Tsimerman ◽  
Artem Osipov ◽  
Margarita G. Dronova
Keyword(s):  
Quantum Yield ◽  
Decay Curve ◽  
Emission Spectra ◽  
Luminescence Spectra ◽  
Ion Energy ◽  
Maximum Value ◽  
Absolute Quantum Yield ◽  
Concentration Dependences ◽  
Yield Values ◽  
Absolute Quantum

Fluoroaluminate glasses of the composition 2Ва (РО3)2–98MgCaSrBaYAl2F14-xErF3, where x=0, 0.1, 0.5, 1.0 mol. % have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. Measured transmission spectra indicate the high practical relevance of the composition of glasses under investigation for photonics and optoelectronics products. In the region of 500–700 nm, luminescence spectra with peaks at about 522, 550, and 665 nm were obtained. The positions of the luminescence bands have been described using an erbium ion energy scheme. The concentration dependences of the absolute quantum yield values for the series of Er3+-doped fluoroaluminate glasses were also established. The maximum value of absolute quantum yield was found for a sample with Er3+ concentration 0.21∙1020 сm-3. The main reason for reducing the values of absolute quantum yield is concentration quenching.

The Concentration Dependences of the Binary Diffusion Coefficients of the Systems H2–Ne, D2–Ne, H2–N2, D2–N2, H2–Ar, and D2–Ar at 1 Atm Pressure and 300 K

1972 ◽  
Vol 50 (14) ◽  
pp. 1644-1647 ◽  
Author(s):  
K. R. Harris ◽  
T. N. Bell ◽  
Peter J. Dunlop
Keyword(s):  
Mole Fraction ◽  
Diffusion Coefficients ◽  
Experimental Error ◽  
Similar Data ◽  
Enskog Theory ◽  
Intermolecular Potentials ◽  
Binary Diffusion ◽  
Concentration Dependences ◽  
Binary Diffusion Coefficients

Binary diffusion coefficients have been measured as a function of concentration for the systems H2–Ne, D2–Ne, D2–N2, H2–Ar, and D2–Ar at 1 atm pressure and 300 K. Similar data have already been presented for the system H2–N2. As predicted by the Chapman–Enskog theory, the concentration dependences of the diffusion coefficients for the systems containing deuterium are somewhat less than for the corresponding systems containing hydrogen. The data for the systems containing Ne and N2 indicate that there may be differences between the parameters required to describe the assumed spherical intermolecular potentials for the systems H2–Ne and D2–Ne, and also for the systems H2–N2 and D2–N2. The concentration dependences of the diffusion coefficients of all six systems are, within the estimated experimental error of ±0.2%, linear in the mole fraction of the heavier component in each system, x2.

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