The catalytic isomerization of allylbenzene in the presence of palladium(II) chloride

1966 ◽  
Vol 19 (5) ◽  
pp. 815 ◽  
Author(s):  
B Cruikshank ◽  
NR Davies
Keyword(s):  
Acetic Acid ◽  
Palladium Complex ◽  
Zero Order ◽  
Small Extent ◽  
Isomerization Reaction ◽  
Methyl Derivative ◽  
Initial Formation ◽  
First Order ◽  
Catalytic Isomerization ◽  
Cis Isomer

Allylbenzene has been shown to isomerize rapidly in the presence of palladmm(11) chloride in acetic acid, mainly to trans-β-methylstyrene but to a small extent to the cis isomer. The reaction is not simple. The initial formation of an olefin complex is succeeded by a further slow reaction involving the palladium complex before isomerization takes place. The isomerization reaction itself is zero order with respect to allylbenzene except nearing completion when it becomes first order in allylbenzene concentration. The reaction is first order with respect to catalyst. Rates have been measured by a technique involving N.M.R. spectrometry. Substitution in allylbenzene inhibits isomerization in the case of 2-bromoallylbenzene but not entirely in the case of the corresponding methyl derivative. The mechanism is discussed in the light of an intermediate hydrido complex.

Catalysis by hydrogen halides in the gas phase. XV. Trimethylacetic acid, isopropanol, and hydrogen bromide

1968 ◽  
Vol 21 (3) ◽  
pp. 701 ◽  
Author(s):  
JTD Cross ◽  
VR Stimson
Keyword(s):  
Acetic Acid ◽  
Gas Phase ◽  
High Pressures ◽  
Hydrogen Bromide ◽  
Zero Order ◽  
Hydrogen Halides ◽  
First Order ◽  
Low Alcohol

Isopropanol decomposes to propene and water in the presence of trimethyl-acetic acid and hydrogen bromide at 407� via isopropyl trimethylacetate. This takes place by isopropanol reacting with an intermediate in the hydrogen bromide catalysed decomposition of trimethylacetic acid. The reaction is first order in each of the acids and first order in the alcohol at low alcohol pressures and zero order at high pressures.

Evaluation of Kinetic Parameters at the Transport of Indole-3-acetic Acid Through Bulk Liquid Membranes

2017 ◽  
Vol 68 (5) ◽  
pp. 903-907
Author(s):  
Ecaterina Anca Serban ◽  
Ioana Diaconu ◽  
Elena Ruse ◽  
Georgiana Ileana Badea ◽  
Adriana Cuciureanu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Kinetic Parameters ◽  
Trioctylphosphine Oxide ◽  
Bulk Liquid ◽  
Transport Parameters ◽  
Kinetics Parameters ◽  
First Order ◽  
Phase Concentration ◽  
Feed Phase ◽  
Indole 3 Acetic Acid

Indole-3-acetic acid is a growth phytohormone considered the most important representative of auxin class. This paper presents the assessment of some kinetic parameters in the process of transport of indole-3-acetic acid taking into consideration the kinetic model of consecutive irreversible first order reactions. It was pursued the influence upon the process of parameters such as: feed phase concentration, stripping phase concentration in the presence of two type carriers: tributyl phosphate (TBP) and trioctylphosphine oxide (TOPO). Depending on these transport parameters were calculated kinetics parameters such as: pseudo-first-order apparent membrane entrance and exit rate constants, the maximum flux at the entrance and exit out of the membrane. The highest values of the transport flux is obtained in the presence of carrier trioctylphosphine oxide (TOPO) at the concentration in the feed phase of 10-4 mol/L indole-3-acetic acid and a concentration of 10--2mol/L NaOH in the stripping phase.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

Area-based speciation kinetic analysis of the multipollutant removal in Constructed Wetlands to enhance its treatment efficiency

2021 ◽  
Author(s):  
Manoj Kumar ◽  
Rajesh Singh
Keyword(s):  
Wastewater Treatment ◽  
Kinetic Analysis ◽  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Zero Order ◽  
Pollutant Removal ◽  
Municipal Wastewater Treatment ◽  
Treatment Efficiency ◽  
First Order ◽  
Present Study Area

In the present study area-based, pollutant removal kinetic analysis was considered using the Zero-order, first-order decay and efficiency loss (EL) models in the constructed wetlands (CWs) for municipal wastewater treatment....

scholarly journals Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

1985 ◽  
Vol 40 (11) ◽  
pp. 1128-1132
Author(s):  
Y. Riad ◽  
Adel N. Asaad ◽  
G.-A. S. Gohar ◽  
A. A. Abdallah
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Main Product ◽  
Reaction Medium ◽  
Aqueous Dioxane ◽  
Proton Abstraction ◽  
First Order ◽  
Water Media ◽  
Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

Supercritical Fluid Deposition of Ruthenium Thin Films: A Kinetic Study

2007 ◽  
Vol 992 ◽  
Author(s):  
Christos F. Karanikas ◽  
James J. Watkins
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Deposition Temperature ◽  
Zero Order ◽  
Measurable Effect ◽  
Deposition Rates ◽  
Reaction Pressure ◽  
Deposition Kinetics ◽  
First Order ◽  
Kinetics Of

AbstractThe kinetics of the deposition of ruthenium thin films from the hydrogen assisted reduction of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II), [Ru(tmhd)2cod], in supercritical carbon dioxide was studied in order to develop a rate expression for the growth rate as well as to determine a mechanism for the process. The deposition temperature was varied from 240°C to 280°C and the apparent activation energy was 45.3 kJ/mol. Deposition rates up to 30 nm/min were attained. The deposition rate dependence on precursor concentrations between 0 and 0.2 wt. % was studied at 260°C with excess hydrogen and revealed first order deposition kinetics with respect to precursor at concentrations lower then 0.06 wt. % and zero order dependence at concentrations above 0.06 wt. %. The effect of reaction pressure on the growth rate was studied at a constant reaction temperature of 260°C and pressures between 159 bar to 200 bar and found to have no measurable effect on the growth rate.

A Stable Mixed Element Method for the Biharmonic Equation with First-Order Function Spaces

2017 ◽  
Vol 17 (4) ◽  
pp. 601-616 ◽  
Author(s):  
Zheng Li ◽  
Shuo Zhang
Keyword(s):  
Biharmonic Equation ◽  
Two Dimensions ◽  
Zero Order ◽  
Helmholtz Decomposition ◽  
Numerical Verification ◽  
Order Function ◽  
First Order ◽  
Mixed Element ◽  
New Formulation ◽  
Element Method

AbstractThis paper studies the mixed element method for the boundary value problem of the biharmonic equation {\Delta^{2}u=f} in two dimensions. We start from a {u\sim\nabla u\sim\nabla^{2}u\sim\operatorname{div}\nabla^{2}u} formulation that is discussed in [4] and construct its stability on {H^{1}_{0}(\Omega)\times\tilde{H}^{1}_{0}(\Omega)\times\bar{L}_{\mathrm{sym}}^% {2}(\Omega)\times H^{-1}(\operatorname{div},\Omega)}. Then we utilise the Helmholtz decomposition of {H^{-1}(\operatorname{div},\Omega)} and construct a new formulation stable on first-order and zero-order Sobolev spaces. Finite element discretisations are then given with respect to the new formulation, and both theoretical analysis and numerical verification are given.

scholarly journals Kinetika Slow Release Pupuk Urea Berlapis Chitosan Termodifikasi

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
YC Danarto ◽  
Anggita Nugrahey ◽  
Sela Murni Noviani
Keyword(s):  
Water Retention ◽  
Slow Release ◽  
Zero Order ◽  
Release Profile ◽  
Nitrogen Release ◽  
Diffusion Kinetic ◽  
Urea Fertilizer ◽  
First Order ◽  
Modified Chitosan ◽  
Urea Content

<p>During this time, the use of urea is not efficient, because about 40-70% of nitrogen in the fertilizer is not absorbed by plants. In order to increase the effectivity of nitrogen release in urea fertilizer, it needs to be coated with modified chitosan as slow releasing agent to form a hydrogel material by forming a cross linking with glutaraldehyde cross-linker.The aims of this research is to study the mechanism and the appropriate kinetic model of nitrogen release in slow releasing fertilizer of modified chitosan. This research was conducted by analyzing the ability of bio-hydrogel by calculating the percentage of swelling ratio and water retention of hydrogel and the nitrogen release in slow releasing fertilizer both in the soil and water. The experiments were conducted by varying the amount of urea used which  30 gram, 40 gram, 50 gram, 60 gram and 70 gram of urea fertilizer. The The release profile is then plotted on several models of diffusion kinetic such as zero order, first order, higuchi and korsmeyer peppas. The appropriate model of diffusion kinetic is chosen by the largest correction factor (R2).The results showed that nitrogen release of the slow releasing fertilizer in the soil with 50% urea content  and  the  water  followed  korsmeyer  peppas  model  with  fickian  mechanism. Nitrogen release in the soil with urea content of 30%, 40%, 60%, and 70% followed the korsmeyer peppas model with nonfickian mechanism.</p>

scholarly journals Akinetic model for the consumption of stabilizer in single base gun propellants

2002 ◽  
Vol 67 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Ljiljana Jelisavac ◽  
Milos Filipovic
Keyword(s):  
Life Time ◽  
Order Reaction ◽  
Zero Order ◽  
Final Phase ◽  
Single Base ◽  
First Order ◽  
Low Concentrations ◽  
Zero Order Reaction ◽  
High Concentrations ◽  
Gun Propellants

A suitable kinetic model for the consumption of stabilizer (diphenylamine) in single base gun propellants was investigated and successfully verified. The model assumes that a reaction of shifting order can be applied for the consumption of diphenylamine in single base gun propellants. It was found that the experimental data were well evaluated by a first-order reaction at high concentrations of diphenylamine in the propellant, but by a zero-order reaction at low concentrations during the final phase of the propellant life time. The mechanism of diphenylamine depletion was discussed with relation to the model and the ageing behavior of the propellants. The kinetic parameters of this model, which permit the calculation of the time up to complete consumption of the diphenylamine, were determined. The results were compared with the kinetic data obtained by a widely accepted model, which combines formally reactions of first and zero order, designated as an "exponential and linear" model. All comparisons gave satisfactory agreement.

Simplified estimation of forage degradability in the rumen assuming zero-order degradation kinetics

2008 ◽  
Vol 147 (3) ◽  
pp. 225-240 ◽  
Author(s):  
M. S. DHANOA ◽  
S. LÓPEZ ◽  
R. SANDERSON ◽  
J. FRANCE
Keyword(s):  
Reference Values ◽  
Incubation Time ◽  
Lag Time ◽  
Zero Order ◽  
Regression Equations ◽  
Order Model ◽  
First Order ◽  
Simplified Procedure ◽  
The Impact ◽  
Time Point

SUMMARYIn the present paper, a simplified procedure using few in situ data points is derived and then evaluated (using a large database) against reference values estimated with the standard nylon bag first-order kinetics model. The procedure proposed involved a two-stage mathematical process, with a statistical prediction of some degradation parameters (such as lag time) and then a kinetic model derived by assuming degradation follows zero-order kinetics to determine effective degradability in the rumen (E). In addition to the estimation of washout fraction and discrete lag, which is common to both procedures, the simplified procedure requires measurement of dry matter losses at one incubation time point only. Thus, interference of the animal rumen will be much reduced, which will lead to increased capacity for feed evaluation. Calibration of the zero-order model against the first-order model showed that suitable estimates of E can be obtained with disappearance at 24, 48 or 72 h as the single incubation end time point. The strength of the calibration is such that an end incubation time point as low as 24 h may be sufficient, which may reduce substantially the total incubation time required and thus the impact on the experimental animal. Relevant regression equations to predict reference values of parameters such as lag time or E are also developed and validated.

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