Experimental data and modeling for excess enthalpies of 2-Pentanol with n-alkanes (C7–C9) at T = (293.15, 298.15 and 303.15) K

2020 ◽  
Vol 28 (6) ◽  
pp. 1661-1669
Author(s):  
Dongwei Wei ◽  
Mengying Li ◽  
Jing Ma ◽  
Baohe Wang
Keyword(s):  
Experimental Data ◽  
Excess Enthalpies

Excess enthalpies of aqueous solutions of biuret at 25 °C. Interaction with urea

1981 ◽  
Vol 59 (8) ◽  
pp. 1257-1260 ◽  
Author(s):  
Guido Barone ◽  
Pasquale Cacace ◽  
Giuseppina Castronuovo ◽  
Vittorio Elia
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Empirical Relation ◽  
Interaction Coefficient ◽  
Excess Enthalpies ◽  
Flow Microcalorimetry ◽  
Heats Of Mixing ◽  
Heats Of Dilution ◽  
The Cross ◽  
First Time

The heats of dilution in water of biuret and the heats of mixing of biuret with urea have been determined by flow microcalorimetry at 25 °C. The excess enthalpies obtained from the experimental data can be expressed as virial expansions of the molalities.The value of the cross interaction coefficient hUB is compared to that calculated through the empirical relation hUB2 = (hUUhBB). The agreement between the two values outlines the strict analogy in the behaviour of these two solutes. The cited combining rule, verified up to now for pairs of solutes having both hii, hjj > 0, is here applied for the first time to a pair having hii, hjj < 0.

Article

1999 ◽  
Vol 77 (3) ◽  
pp. 299-307
Author(s):  
J García ◽  
M J Comuñas ◽  
L Lugo ◽  
E R López ◽  
J Fernández
Keyword(s):  
Experimental Data ◽  
Infinite Dilution ◽  
Excess Molar Volumes ◽  
Excess Enthalpies ◽  
Group Contributions ◽  
Characteristic Parameters ◽  
Molar Volumes ◽  
Gibbs Energies ◽  
Excess Gibbs Energies ◽  
Group Contribution Model

Excess molar volumes at 298.15 K for the binary mixtures of a 1-bromoalkane with a n-alkane are reported. The VE values were obtained from measurements of the density with an Anton Paar densimeter. Literature data of excess Gibbs energies, excess enthalpies, excess volumes, and activity coefficients at infinite dilution for this kind of mixtures together with molar volumes and vaporization enthalpies of pure bromoalkanes were used to calculate the characteristic parameters of the Nitta-Chao group contribution model. With the obtained parameters, this model consistently describes the experimental data of the 1-bromoalkane + n-alkane mixtures. Furthermore, we have determined the energetic parameters for the Larsen version of the UNIFAC model.Key words: liquids, mixtures, thermodynamics, group contributions.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

On the Meta-Analysis of Nonrandom, Quasi-Experimental Data

2010 ◽  
Author(s):  
Richard N. Landers
Keyword(s):  
Experimental Data ◽  
Meta Analysis ◽  
Quasi Experimental

Excess enthalpies of some aromatic amine + benzene mixtures

1979 ◽  
Vol 76 ◽  
pp. 381-382 ◽  
Author(s):  
Inmaculada Velasco ◽  
Santos Otín ◽  
Celso Gutiérrez-Losa
Keyword(s):  
Aromatic Amine ◽  
Excess Enthalpies

A fuzzy neural network approach for modeling the growth kinetics of FeB and Fe2B layers during the boronizing process

2018 ◽  
Vol 106 (6) ◽  
pp. 603 ◽  
Author(s):  
Bendaoud Mebarek ◽  
Mourad Keddam
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Fuzzy Neural Network ◽  
Treatment Time ◽  
Calculation Model ◽  
Average Error ◽  
Network Approach ◽  
Neural Network Approach ◽  
Fuzzy Neural ◽  
Kinetics Of

In this paper, we develop a boronizing process simulation model based on fuzzy neural network (FNN) approach for estimating the thickness of the FeB and Fe2B layers. The model represents a synthesis of two artificial intelligence techniques; the fuzzy logic and the neural network. Characteristics of the fuzzy neural network approach for the modelling of boronizing process are presented in this study. In order to validate the results of our calculation model, we have used the learning base of experimental data of the powder-pack boronizing of Fe-15Cr alloy in the temperature range from 800 to 1050 °C and for a treatment time ranging from 0.5 to 12 h. The obtained results show that it is possible to estimate the influence of different process parameters. Comparing the results obtained by the artificial neural network to experimental data, the average error generated from the fuzzy neural network was 3% for the FeB layer and 3.5% for the Fe2B layer. The results obtained from the fuzzy neural network approach are in agreement with the experimental data. Finally, the utilization of fuzzy neural network approach is well adapted for the boronizing kinetics of Fe-15Cr alloy.

Use of Posterior Probabilities to Evaluate Methods of Discriminant Analysis

1981 ◽  
Vol 20 (04) ◽  
pp. 207-212 ◽  
Author(s):  
J. Hermans ◽  
B. van Zomeren ◽  
J. W. Raatgever ◽  
P. J. Sterk ◽  
J. D. F. Habbema
Keyword(s):  
Experimental Data ◽  
Discriminant Analysis ◽  
Posterior Probabilities

By means of a case study the choice between several methods of discriminant analysis is presented. Experimental data of a two-groups problem with one or two variables is analysed. The different methods are compared according to posterior probabilities which can be computed for each subject and which are the basis of discriminant analysis. These posterior probabilities are analysed graphically as well as numerically.

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