scholarly journals Mechanistic study of CBT-Cys click reaction and its application for identifying bioactive N-terminal cysteine peptides in amniotic fluid

2017 ◽  
Vol 8 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Zhen Zheng ◽  
Peiyao Chen ◽  
Gongyu Li ◽  
Yunxia Zhu ◽  
Zhonghua Shi ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Rate Constant ◽  
Reaction Rate ◽  
Click Reaction ◽  
Condensation Reaction ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Mechanistic Study ◽  
Second Order Reaction ◽  
Wide Applicability

CBT-Cys click condensation reaction has a high second-order reaction rate constant and has found wide applicability in recent years.

Effect of Ozone Oxidation on the Molecular and Kinetic Properties of Effluent Organic Matter

2008 ◽  
Vol 11 (3) ◽  
Author(s):  
Fernando L. Rosario-Ortiz ◽  
Stephen P. Mezyk ◽  
Eric C. Wert ◽  
Devin F. R. Doud ◽  
Manu K. Singh ◽  
...  
Keyword(s):  
Organic Matter ◽  
Hydroxyl Radical ◽  
Rate Constant ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Kinetic Properties ◽  
Second Order Reaction ◽  
Effluent Organic Matter ◽  
Ozone Oxidation

AbstractThe effect of ozone oxidation on the second order reaction rate constant between effluent organic matter (EfOM) and hydroxyl radical (

scholarly journals Determination of exothermic batch reactor specific model parameters

2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků
Keyword(s):  
Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Specific Model ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
First Order Reaction ◽  
Model Parameters ◽  
Reactor Model ◽  
First Order

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

scholarly journals Kinetic and Mechanistic Study of Rhodamine B Degradation by H2O2 and Cu/Al2O3/g-C3N4 Composite

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 317 ◽  
Author(s):  
Chunsun Zhou ◽  
Zhongda Liu ◽  
Lijuan Fang ◽  
Yulian Guo ◽  
Yanpeng Feng ◽  
...  
Keyword(s):  
Rate Constant ◽  
Rhodamine B ◽  
Active Sites ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Mechanistic Study ◽  
Al2o3 Composite ◽  
Degradation Rates ◽  
Wide Range ◽  
Alkaline Conditions

The classic Fenton reaction, which is driven by iron species, has been widely explored for pollutant degradation, but is strictly limited to acidic conditions. In this work, a copper-based Fenton-like catalyst Cu/Al2O3/g-C3N4 was proposed that achieves high degradation efficiencies for Rhodamine B (Rh B) in a wide range of pH 4.9–11.0. The Cu/Al2O3 composite was first prepared via a hydrothermal method followed by a calcination process. The obtained Cu/Al2O3 composite was subsequently stabilized on graphitic carbon nitride (g-C3N4) by the formation of C−O−Cu bonds. The obtained composites were characterized through FT-IR, XRD, TEM, XPS, and N2 adsorption/desorption isotherms, and the immobilized Cu+ was proven to be active sites. The effects of Cu content, g-C3N4 content, H2O2 concentration, and pH on Rh B degradation were systematically investigated. The effect of the catalyst dose was confirmed with a specific reaction rate constant of (5.9 ± 0.07) × 10−9 m·s−1 and the activation energy was calculated to be 71.0 kJ/mol. In 100 min 96.4% of Rh B (initial concentration 20 mg/L, unadjusted pH (4.9)) was removed in the presence of 1 g/L of catalyst and 10 mM of H2O2 at 25 °C, with an observed reaction rate constant of 6.47 × 10−4 s−1. High degradation rates are achieved at neutral and alkaline conditions and a low copper leaching (0.55 mg/L) was observed even after four reaction cycles. Hydroxyl radical (HO·) was identified as the reactive oxygen species by using isopropanol as a radical scavenger and by ESR analysis. HPLC-MS revealed that the degradation of Rh B on Cu/Al2O3/CN composite involves N-de-ethylation, hydroxylation, de-carboxylation, chromophore cleavage, ring opening, and the mineralization process. Based on the results above, a tentative mechanism for the catalytic performance of the Cu/Al2O3/g-C3N4 composite was proposed. In summary, the characteristics of high degradation rate constants, low ion leaching, and the excellent applicability in neutral and alkaline conditions prove the Cu/Al2O3/g-C3N4 composite to be a superior Fenton-like catalyst compared to many conventional ones.

An Investigation into the Conversion of Propylene Glycol to 2,4-dimethyl-1,3-dioxolane over an Acid Catalyst Using Gas Chromatography

2013 ◽  
Vol 850-851 ◽  
pp. 82-85
Author(s):  
Zuo You Zhang ◽  
Hui Chen ◽  
Xia Li ◽  
Zhao Hui Yang ◽  
Bao Chen Liang
Keyword(s):  
Aqueous Solution ◽  
Reaction Rate ◽  
Acid Catalyst ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Gas Chromatograph ◽  
Second Order Reaction ◽  
Operational Parameters

In the presence of an acid catalyst, PG react reversibly with acetaldehyde to form 2,4-dim-ethyl-1,3-dioxolane (24DMD). The effects of different operational parameters on PG conversion had been analyzed in paper, parameters included temperature, reaction time, amount of catalyst and aqueous acetaldehyde/PG molar ratio. Under optimal condition, 85% conversion of PG in aqueous solution was achieved within 180 min of reaction. The analysis of PG was conducted by gas chromatograph. Furthermore, reaction followed the second-order reaction kinetics, and the reaction rate constant was found to be 29.68min-1.

Photochemical reaction of superoxide radicals with 1-naphthol

2021 ◽  
Author(s):  
Ying Liu ◽  
Mengyu Zhu ◽  
Yadong Hu ◽  
Yijun Zhao ◽  
Chengzhu Zhu
Keyword(s):  
Photochemical Reaction ◽  
Reaction Rate ◽  
Surface Reaction ◽  
Atmospheric Model ◽  
Bulk Water ◽  
Reaction Rate Constant ◽  
Photochemical Reactions ◽  
Order Reaction ◽  
Reaction Pathways ◽  
Second Order Reaction

he photochemical reactions between 1-naphthol (1-NP) and superoxide anion radical (O2•−) were investigated in detail by using 365 nm UV irradiation. The results showed that the conversion rate of 1-naphthol decreased with the increase of the initial concentration of 1-naphthol, while the raising pH and riboflavin concentration accelerated the photochemical reaction. The second-order reaction rate constant was estimated to be (3.64 ± 0.17) × 108 L mol−1 s−1. The major photolysis products identified by using gas chromatography-mass spectrum (GC-MS) were 1, 4-naphquinone and 2, 3-epoxyresin-2, 3-dihydro-1, 4-naphquinone, and their reaction pathways were also discussed. An atmospheric model showed that both bulk water reaction and heterogeneous surface reaction deserved attentions in atmospheric aqueous chemistry.

Pyrolysis Modeling in a Woodstove

2008 ◽  
Author(s):  
Rajesh Gupta
Keyword(s):  
Rate Constant ◽  
Empirical Model ◽  
Reaction Rate ◽  
Packed Bed ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Simple Empirical Model

A simple empirical model for predicting the pyrolysis rate of fuel packed bed of a woodstove has been presented. The thermolytic behavior of the fuel bed has been approximated by a pseudo-first order reaction. The reaction rate constant has been determined as function of temperature. The effect of orientation of twigs in the fuel bed arrangement and twig diameter on the reaction rate constant has been analyzed. It has been concluded that the effect of twig orientation is insignificant while the peak magnitude of reaction rate constant increased with increasing twig diameter.

Kinetics of the reaction of methyl iodide with sulfite and thiosulfate ions in aqueous solution

1969 ◽  
Vol 47 (24) ◽  
pp. 4537-4541 ◽  
Author(s):  
R. A. Hasty ◽  
S. L. Sutter
Keyword(s):  
Activation Energy ◽  
Methyl Iodide ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Kcal Mole ◽  
Rate Of Reaction ◽  
Kinetics Of ◽  
Sulfite Ion

The rate of reaction of methyl iodide with sulfite ion is determined. In addition, the rate of reaction of methyl iodide with thiosulfate ion is reexamined and the rate of reaction of methyl iodide with bisulfite ion is estimated. A pronounced effect of ionic strength on the reaction rate in the methyl iodide – sulfite ion system is observed, this effect does not occur in the methyl iodide – thiosulfate ion system. The second order reaction rate constant and activation energy for the reaction of methyl iodide with the respective nucleophiles are: SO32−, 4.4 × 10−2M−1 s−1, 18.6 kcal mole−1; HSO3−, 1 × 10−3M−1 s−1, 18.4 kcal mole−1; and S2O32− 3.1 × 10−2M−1 s−1, 19.4 kcal mole−1.

scholarly journals Virtual Instrument for Determining Rate Constant of Second-Order Reaction bypXBased on LabVIEW 8.0

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Hu Meng ◽  
Jiang-Yuan Li ◽  
Yong-Huai Tang
Keyword(s):  
Rate Constant ◽  
Virtual Instrument ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Second Order Reaction ◽  
Processing Data ◽  
Testing Data ◽  
Manual Processing ◽  
Data Acquiring ◽  
Conditioning Circuit

The virtual instrument system based on LabVIEW 8.0 for ion analyzer which can measure and analyze ion concentrations in solution is developed and comprises homemade conditioning circuit, data acquiring board, and computer. It can calibrate slope, temperature, and positioning automatically. When applied to determine the reaction rate constant bypX, it achieved live acquiring, real-time displaying, automatical processing of testing data, generating the report of results; and other functions. This method simplifies the experimental operation greatly, avoids complicated procedures of manual processing data and personal error, and improves veracity and repeatability of the experiment results.

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