Rate of Reaction of Nitrogen Atoms with Ethylene

1960 ◽  
Vol 33 (4) ◽  
pp. 1273-1274 ◽  
Author(s):  
John T. Herron
Keyword(s):  
Rate Of Reaction

Notizen: Effect of Magnetic Field on Ascorbic Acid Oxidase Activity, I

1986 ◽  
Vol 41 (3) ◽  
pp. 355-358 ◽  
Author(s):  
V. S. Ghole ◽  
P. S. Damle ◽  
W. H.-P. Thiemann
Keyword(s):  
Magnetic Field ◽  
Ascorbic Acid ◽  
Homogeneous Magnetic Field ◽  
Acid Oxidase ◽  
High Substrate Concentration ◽  
Ascorbic Acid Oxidase ◽  
Rate Of Reaction ◽  
Substrate Concentrations ◽  
Burk Plot

A homogeneous magnetic field of 1.1 T strength exhibits a significant influence on the activity of the enzyme ascorbic acid oxidase in vitro. A Lineweaver-Burk plot of the reaction shows the typical pattern of a mixed-type inhibition, i.e. a larger rate of reaction at low substrate concentrations and a smaller rate of reaction at high substrate concentration than that of the control without magnetic field applied.

Green synthesized Ag-TiO2 for degradation of organic dye through visible light driven photo-reactor and its kinetics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Titikshya Mohapatra ◽  
Sakshi Manekar ◽  
Vijyendra Kumar Sahu ◽  
Ashwini Kumar Soni ◽  
Sudip Banerjee ◽  
...  
Keyword(s):  
Visible Light ◽  
Mangifera Indica ◽  
Band Gap Energy ◽  
Photo Degradation ◽  
X Ray ◽  
Green Approach ◽  
Vis Spectroscopy ◽  
Rate Of Reaction ◽  
Visible Light Driven ◽  
Modification Of Titanium

Abstract This study reports a green approach for the modification of titanium dioxide (TiO2) nanoparticles with immobilization of silver nanoparticles. One of the natural sources i.e., Mangifera indica leaf extract was utilized as reducing and capping agent for the fabrication of Ag-TiO2 nanocatalyst. Further, the surface morphology and band-gap energy of prepared Ag-TiO2 were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and UV–Vis spectroscopy. Also, it was characterized by X-ray Powder Diffraction (XRD) which provides the information regarding the crystallinity of the Ag-TiO2. Subsequently, photo activity of Ag-TiO2 was investigated for the degradation of methylene blue (MB) dye wastewater through visible light driven photoreactor. The Ag-TiO2 provided highest (68%) of photo-degradation efficiency within 110 min for 7.81 × 10−5 mol/L initial MB concentration at pH 8 by using 0.19 g/L photocatalyst. Further, addition of 10 mM H2O2 boost up the MB photodegradation to 74%. The kinetic study confirmed the MB degradation followed first order rate of reaction.

THE ALKALINE CLEAVAGE OF o-NITROBENZYLTRIMETHYLSILANE SOLVENT EFFECTS IN THE DIOXANE–WATER SYSTEM

1963 ◽  
Vol 41 (6) ◽  
pp. 1525-1530 ◽  
Author(s):  
H. R. Allcock
Keyword(s):  
Transition State ◽  
Solvent Effects ◽  
Water System ◽  
Solvent Polarity ◽  
High Water ◽  
Aqueous Dioxane ◽  
Alkaline Cleavage ◽  
Rate Of Reaction ◽  
Kinetics Of

The kinetics of alkaline cleavage of o-nitrobenzyltrimethylsilane were examined in aqueous dioxane media. At high water concentrations, increases in solvent polarity retard the cleavage, as required by a mechanism involving charge dispersion in the transition state. At high dioxane concentrations, solvent polarity increases are accompanied by increases in the rate of reaction, a result which may reflect association between the solvent components.

Oxidation of hydrocarbons in the liquid phase: n-dodecane in a borosilicate glass chamber at 200 °C

1969 ◽  
Vol 47 (22) ◽  
pp. 4175-4182 ◽  
Author(s):  
B. D. Boss ◽  
R. N. Hazlett
Keyword(s):  
Liquid Phase ◽  
Borosilicate Glass ◽  
Current Knowledge ◽  
Reaction Chamber ◽  
Cyclic Ethers ◽  
Reaction Products ◽  
Isomer Distribution ◽  
Oxidation Of Hydrocarbons ◽  
Volatile Products ◽  
Rate Of Reaction

The 5-h oxidation of n-dodecane at 200 °C by air at 1 atm is reported for experiments in a borosilicate glass reaction chamber equipped with a gas bubbler. The rate of reaction was limited by the rate of oxygen diffusion from the gas phase due to the rapid reaction of dissolved oxygen. The reaction products were analyzed in aliquots taken periodically from the reaction chamber. Chemical analyses, gas–liquid phase chromatography (g.l.p.c.), tandem g.l.p.c.-mass spectroscopy, infrared, and ultraviolet were used to identify products accounting for 98% of the oxygen reacted. The isomer distribution of the dodecenes, dodecanols, and dodecanones formed, as well as the distribution of carboxylic acids, were determined. Three classes of intramolecular reaction products, cyclic ethers, cyclic hydrocarbons, and lactones, were detected. Many volatile products were detected. A filterable precipitate obtained after 10 h of oxidation was studied using infrared attenuated total reflectance techniques. A reaction mechanism is discussed based on current knowledge of other systems, the products identified, and the stoichiometry of the reaction.

scholarly journals Extracellular α-Galactosidase from Trichoderma sp. (WF-3): Optimization of Enzyme Production and Biochemical Characterization

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Aishwarya Singh Chauhan ◽  
Arunesh Kumar ◽  
Nikhat J. Siddiqi ◽  
B. Sharma
Keyword(s):  
Enzyme Activity ◽  
Enzyme Assay ◽  
Biochemical Characterization ◽  
Catalytic Efficiency ◽  
Culture Conditions ◽  
Significant Loss ◽  
Trichoderma Sp ◽  
Rate Of Reaction ◽  
Higher Temperature ◽  
Substrate Concentrations

Trichoderma spp. have been reported earlier for their excellent capacity of secreting extracellular α-galactosidase. This communication focuses on the optimization of culture conditions for optimal production of enzyme and its characterization. The evaluation of the effects of different enzyme assay parameters such as stability, pH, temperature, substrate concentrations, and incubation time on enzyme activity has been made. The most suitable buffer for enzyme assay was found to be citrate phosphate buffer (50 mM, pH 6.0) for optimal enzyme activity. This enzyme was fairly stable at higher temperature as it exhibited 72% activity at 60°C. The enzyme when incubated at room temperature up to two hours did not show any significant loss in activity. It followed Michaelis-Menten curve and showed direct relationship with varying substrate concentrations. Higher substrate concentration was not inhibitory to enzyme activity. The apparent Michaelis-Menten constant (Km), maximum rate of reaction (Vmax), Kcat, and catalytic efficiency values for this enzyme were calculated from the Lineweaver-Burk double reciprocal plot and were found to be 0.5 mM, 10 mM/s, 1.30 U mg−1, and 2.33 U mg−1 mM−1, respectively. This information would be helpful in understanding the biophysical and biochemical characteristics of extracellular α-galactosidase from other microbial sources.

The gas phase reactivity of the dimethylchloronium ion with alkylbenzenes

1981 ◽  
Vol 59 (15) ◽  
pp. 2412-2416 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin ◽  
Jeffrey Varah
Keyword(s):  
High Pressure ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Aromatic Hydrocarbons ◽  
Relative Rate ◽  
Ion Source ◽  
Nucleophilic Displacement ◽  
Rate Of Reaction ◽  
Displacement Reactions ◽  
Bonded Complexes

The reactivity of the dimethylchloronium ion with a series of aromatic hydrocarbons has been studied in a high pressure mass spectrometer ion source using the technique of reactant ion monitoring. Benzene is unreactive but all others, from toluene to mesitylene, react by CH3+ transfer to yield σ-bonded complexes. The relative rate of reaction increases with increasing exothermicity in line with current theories of nucleophilic displacement reactions.

scholarly journals Kinetics of thiamin cleavage by sulphite

1969 ◽  
Vol 113 (4) ◽  
pp. 611-615 ◽  
Author(s):  
J. Leichter ◽  
M. A. Joslyn
Keyword(s):  
Aqueous Solutions ◽  
Rate Constant ◽  
Sulphur Dioxide ◽  
First Order ◽  
Ph Values ◽  
Rate Of Reaction ◽  
Kinetics Of

Results are presented on the rate of thiamin cleavage by sulphite in aqueous solutions as affected by temperature (20–70°), pH(2·5–7·0), and variation of the concentration of either thiamin (1–20μm) or sulphite (10–5000μm as sulphur dioxide). Plots of the logarithm of percentage of residual thiamin against time were found to be linear and cleavage thus was first-order with respect to thiamin. At pH5 the rate was also found to be proportional to the sulphite concentration. In the pH region 2·5–7·0 at 25° the rate constant was 50m−1hr.−1 at pH5·5–6·0, and decreased at higher or lower pH values. The rate of reaction increased between 20° and 70°, indicating a heat of activation of 13·6kcal./mole.

The mechanism of the oxidation of thiocyanate ion by peroxomonosulphate in aqueous solution. II. Kinetics of the reaction

1966 ◽  
Vol 19 (8) ◽  
pp. 1365 ◽  
Author(s):  
RH Smith ◽  
IR Wilson
Keyword(s):  
Aqueous Solution ◽  
Initial Rate ◽  
Stopped Flow ◽  
Thiocyanate Ion ◽  
First Order ◽  
Conductance Method ◽  
Rate Of Reaction ◽  
Kinetics Of

Initial rates of reaction for the above oxidation have been measured by a stopped-flow conductance method. Between pH 2 and 3.6, the initial rate of reaction, R, is given by the expression R{[HSO5-]+[SCN-]} = {kb+kc[H+]}[HSO5-]0[SCN-]20+ka[H+]-1[HSO5]20[SCN-]0 As pH increases, there is a transition to a pH-independent rate, first order in each thiocyanate and peroxomonosulphate concentrations.

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