The Effect of Temperature and Solvent upon the Addition of 4-Chlorobenzenesulfenyl Chloride to cis- and trans-1-Phenylpropene

1972 ◽  
Vol 50 (15) ◽  
pp. 2465-2469 ◽  
Author(s):  
George H. Schmid ◽  
Valeria M. Csizmadia
Keyword(s):  
Thermodynamic Parameters ◽  
Effect Of Temperature ◽  
Kinetic And Thermodynamic Parameters ◽  
Product Composition ◽  
Kinetically Controlled ◽  
The One ◽  
Cis And Trans

The effect of temperature upon the product composition of the addition of 4-chlorobenzenesulfenyl chloride to cis- and trans-1-phenylpropene in 1,1,2,2-tetrachloroethane has been studied. The kinetically controlled product in both cases is the adduct with Markownikoff orientation while the thermodynamically controlled product is the one with the anti-Markownikoff orientation. Kinetic and thermodynamic parameters have been determined for the isomerization of the threo as well as the erythro adducts. The effect of different solvents on the product composition has been studied at 25°. The regioselectivity towards Markownikoff product parallels the increasing acidity and anion solvating ability of the solvent.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

scholarly journals Effect of Temperature on the Corrosion Inhibition of Trans-4-Hydroxy-4′-Stilbazole on Mild Steel in HCl Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ayssar Nahlé ◽  
Ideisan I. Abu-Abdoun ◽  
Ibrahim Abdel-Rahman
Keyword(s):  
Weight Loss ◽  
Double Bond ◽  
Adsorption Isotherm ◽  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Thermodynamic Parameters ◽  
The Other ◽  
Effect Of Temperature ◽  
Temkin Adsorption Isotherm ◽  
Hcl Solution

The inhibition and the effect of temperature and concentration of trans-4-hydroxy-4′-stilbazole on the corrosion of mild steel in 1 M HCl solution was investigated by weight loss experiments at temperatures ranging from 303 to 343 K. The studied inhibitor concentrations were between  M and  M. The percentage inhibition increased with the increase of the concentration of the inhibitor. The percentage inhibition reached about 94% at the concentration of  M and 303 K. On the other hand, the percentage inhibition decreased with the increase of temperature. Using the Temkin adsorption isotherm, the thermodynamic parameters for the adsorption of this inhibitor on the metal surface were calculated. Trans-4-hydroxy-4′-stilbazole was found to be a potential corrosion inhibitor since it contained not only nitrogen and oxygen, but also phenyl and pyridine rings that are joined together with a double bond (–C=C–) in conjugation with these rings.

Kinetic and thermodynamic parameters for oxygen binding to the allosteric states of panulirus interruptus hemocyanin

1983 ◽  
Vol 18 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Eraldo Antonini ◽  
Maurizio Brunori ◽  
Alfredo Colosimo ◽  
Harm A. Kuiper ◽  
Lello Zolla
Keyword(s):  
Thermodynamic Parameters ◽  
Oxygen Binding ◽  
Panulirus Interruptus ◽  
Kinetic And Thermodynamic Parameters

scholarly journals Kinetic and Thermodynamic Analysis of Two Carboxymethylcellulases from Macrotermes subhyalinus Little Soldier

2017 ◽  
Vol 9 (4) ◽  
pp. 17
Author(s):  
Jean B. Fagbohoun ◽  
Mankambou J. Gnanwa ◽  
Fankroma M. T. Kone ◽  
S. Dabonne ◽  
Patrice L. Kouame
Keyword(s):  
Thermodynamic Parameters ◽  
Thermal Inactivation ◽  
Molecular Conformation ◽  
Residual Activity ◽  
Degradation Kinetic ◽  
Macrotermes Subhyalinus ◽  
Kinetic And Thermodynamic Parameters ◽  
Technology Applications ◽  
Kinetic And Thermodynamic Analysis ◽  
Increasing Temperature

Optimization of thermal processes relies on adequate degradation kinetic models to warrant food safety and quality. The knowledge on thermal inactivation of enzymes is necessary to allow their proper utilization in food industry and technology applications, enabling the reduction of heating times and optimization of heating temperatures. In this work, the kinetic of thermal inactivation was studied for the previously characterized carboxylmethylcellulases Ab-CX1 and Ab-CX2 from Macrotermes subhyalinus little soldier. Samples of carboxymethylcellulases were treated at different time-temperature combinations in the range of 5-60 min at 50-65°C and the kinetic and thermodynamic parameters for carboxymethylcellulases were calculated. Results showed that inactivation followed a first-order reaction with k-values between 0.0103 ± 0.0003 to 0.1217 ± 0.0005 and 0.0149 ± 0.0007 to 0.0416 ± 0.0003 min-1 for Ab-CX1 and Ab-CX2, respectively. At high temperatures, Ab-CX2 was less resistant, with a significant decrease in residual activity compared to Ab-CX1. The D- and k-values decreased and increased, respectively, with increasing temperature, indicating faster inactivation of carboxymethylcellulases. Activation energy (Ea) and Z-values were estimated to 76.74 ± 1.98 kJ.mol-1 and 24.21 ± 1.92 °C for Ab-CX1, 62.80 ± 2.05 kJ.mol-1 and 33.33 ± 2.78 °C for Ab-CX2. Thermodynamic parameters (ΔH#, ΔS# and ΔG#) were also calculated. The high value obtained for the variation in enthalpy of activation indicates that a high amount of energy is required to initiate denaturation, probably due to the molecular conformation of carboxymethylcellulases. All results suggest that both carboxymethylcellulases are relatively resistant to long heat treatments up to 50°C.

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