Urokinase Activation of Plasminogen and Spontaneous Inactivation of the Plasmin Formed

1968 ◽  
Vol 19 (01/02) ◽  
pp. 145-160 ◽  
Author(s):  
W Berg
Keyword(s):  
Order Reaction ◽  
Zero Order ◽  
Inactivation Rate ◽  
First Order Reaction ◽  
Activity Levels ◽  
First Order ◽  
Activation Rate ◽  
Zero Order Reaction ◽  
High Concentrations ◽  
Kinetics Of

SummaryThe kinetics of the activation of plasminogen into plasmin with urokinase and the inactivation rate of the plasmin formed are studied.As a first order reaction is obtained with low plasminogen concentrations and a zero-order reaction is obtained with high concentrations, the activation seems to follow the Michaelis-Menten’s law. The reaction does not go to completion, however. Different activity levels, which are dependent on the urokinase concentration, can be observed.The activation rate increases with temperature. A maximum can be seen at about 42° C.Between 4° C and 15° C, the inactivation of the plasmin formed is minimal, but it increases rapidly at higher temperatures. The inactivation follows approximately a first order reaction with respect to time. If the plasminogen concentration is low, the over-all reaction will be that of two consecutive first order reactions.

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.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

1993 ◽  
Vol 28 (2) ◽  
pp. 135-144 ◽  
Author(s):  
S. Matsui ◽  
R. Ikemoto Yamamoto ◽  
Y. Tsuchiya ◽  
B. Inanc
Keyword(s):  
Sulfate Reduction ◽  
Fluidized Bed ◽  
Kinetic Equations ◽  
Fluidized Bed Reactor ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Glucose Decomposition ◽  
Reaction Equations ◽  
Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

The Characteristics and Kinetics of 4-CP with Pb2+ Biodegradation by Fusarium sp.

2013 ◽  
Vol 726-731 ◽  
pp. 2506-2509
Author(s):  
Xiao Xiao Wang ◽  
Xiao Qin Yu ◽  
Jun Ya Pan ◽  
Ji Wu Li
Keyword(s):  
Carbon Source ◽  
Kinetic Equations ◽  
Order Reaction ◽  
Zero Order ◽  
Biodegradation Rate ◽  
Reaction Equation ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Additional Carbon Source

The effects of Pb2+concentration, pH and additional carbon source on biodegradation of 4-chlorophenol (4-CP) byFusariumsp. were investigated, and the characteristic and kinetic of 4-CP biodegradation were analyzed. It was concluded that 4-CP biodegradation rate byFusariumsp. decreased a little at concentration of Pb2+0.20 mg/L and 4-CP 50 mg/L. The suitable biodegradation pH was range from 6 to 7. Additional carbon source (phenol) might increase the rate of 4-CP biodegradation. The kinetic equations of 4-CP biodegradation were well accord with the zero order reaction equation at different concentration of Pb2+.

Direct Method for Determining Inorganic Phosphate in Serum with the "CentrifiChem"

1972 ◽  
Vol 18 (3) ◽  
pp. 263-265 ◽  
Author(s):  
John A Daly ◽  
Gerhard Ertingshausen
Keyword(s):  
Inorganic Phosphate ◽  
Direct Method ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Kinetics Of ◽  
A Direct Method

Abstract A direct method was developed for determining inorganic phosphate in serum, which requires only a single reagent addition. The method quantitates the unreduced phosphomolybdate heteropolyacid at 340 nm and is linear to at least 10 mg of phosphate per 100 ml. Only 10 µl of serum is required. The unique blanking capabilities of centrifugal analyzers permit the "on run" elimination of serum and reagent background absorbances, which are automatically subtracted. Data on precision, correlation, and recovery are presented. Kinetics of the reaction were studied, and theoretical limits of automatic blanking when applied to a first-order reaction are discussed.

Development of Torrefaction Kinetics for British Columbia Softwoods

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Jianghong Peng ◽  
Xiaotao T. Bi ◽  
Jim Lim ◽  
Shabab Sokhansanj
Keyword(s):  
British Columbia ◽  
Weight Loss ◽  
Kinetic Model ◽  
Residence Time ◽  
Order Reaction ◽  
First Order Reaction ◽  
Chemical Components ◽  
First Order ◽  
One Step ◽  
Kinetics Of

Torrefaction is a thermal treatment without air or oxygen in the temperature range of 473-573 K. The pyrolysis kinetics of three chemical components (cellulose, hemicelluloses, and lignin) and wood at low temperatures of relevance to torrefaction conditions have been reviewed. A series of thermogravimetric (TG) experiments have been carried out to study the intrinsic torrefaction kinetics of major chemical components and British Columbia (BC) softwoods. The weight loss during BC softwood torrefaction was found to be mainly associated with the decomposition of hemicelluloses, although there was also certain degree of decomposition of cellulose and lignin. The weight loss of the BC softwoods during torrefaction could be approximately estimated from the chemical composition of wood species and the weight loss data for torrefaction of pure cellulose, hemicelluloses, and lignin, respectively. Based on the fitting of the TG curves of BC softwoods and three chemical components, two different torrefaciton models were proposed. The simple one-step (single-stage) kinetic model with the first order reaction can predict the reaction data reasonably well over the long residence time, with the final sample weight being strongly related to the torrefaction temperature. A two-component and one-step first order reaction kinetic model, on the other hand, gave improved agreement with data over short residence time, and can be used to guide the design and optimization of torrefaction reactors over the weight loss range of 0 to 40% at the temperature range of 533-573 K, which covers the typical range of industrially relevant operations.

Kinetics of Cs adsorption/desorption on granite by a pseudo first order reaction model

2007 ◽  
Vol 275 (3) ◽  
pp. 555-562 ◽  
Author(s):  
Shih-Chin Tsai ◽  
Tsing-Hai Wang ◽  
Yuan-Yaw Wei ◽  
Wen-Chun Yeh ◽  
Yi-Lin Jan ◽  
...  
Keyword(s):  
Reaction Model ◽  
Order Reaction ◽  
First Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Adsorption Desorption ◽  
Kinetics Of

Synthesizes and Properties Research of a Photochromic Diarylethene Bearing a Hexatomic Ring

2013 ◽  
Vol 830 ◽  
pp. 278-281
Author(s):  
Zhi Yuan Sun ◽  
Wei Wei Geng ◽  
Shou Zhi Pu
Keyword(s):  
Reaction Kinetics ◽  
Fluorescence Intensity ◽  
Uv Light ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Solid Films ◽  
Kinetics Of

A new photochromic diarylethene compound 1-(2-cyan-3-phenyl)-2-[5-(4-cyanobenzene) -2-methyl-3-thienyl] perfluorocyclopentene was synthesized. And their properties inculding photochromis, fluorescence in both hexane and solid films, reaction kinetics of cyclization and cycloreversion were studied. And its absorption maxima were observed at 539 nm in hexane and at 552 nm in PMMA films, respectively, upon irradiation with 313 nm UV light. The fluorescence intensity of diarylethene decreased upon irradiation with 313 nm UV light. Besides, the cyclization and cycloreversion processes of the compound were determined to be the zeroth and first order reaction by UV-Vis spectra, respectively.

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