scholarly journals THERMAL DISAPPEARANCE KINETICS OF RADICALS FORMED DURING RADIOLYSIS IN POLYCRYSTALLINE SOLID STATE OF SODIDM WOLFRAMATE DIHYDRATE

2010 ◽  
Vol 18 (18) ◽  
pp. 49-64
Author(s):  
Mihail Contineanu ◽  
Adina-Elena Stanciu ◽  
Iulia Contineanu ◽  
Ana Neacsu
Keyword(s):  
Solid State ◽  
Gamma Irradiation ◽  
Kinetic Study ◽  
Thermal Annealing ◽  
Kinetic Data ◽  
Room Temperature ◽  
Paramagnetic Centers ◽  
Polycrystalline Solid ◽  
Kinetics Of ◽  
Disappearance Kinetics

A kinetic study of the WO4- radical, formed by gamma irradiation of polycrystalline Na2 WO4.2H2O UCB at room temperature has been performed using the EPR technique. A suitable mechanism for the formation of paramagnetic centers by irradiation and thermal annealing is proposed. The mechanism agrees well with the experimental kinetic data.

Kinetic Study on Crude Laccase of Marasmius sp. from Solid State Fermentation

2020 ◽  
Vol 840 ◽  
pp. 131-136
Author(s):  
Hendro Risdianto ◽  
Susi Sugesty
Keyword(s):  
Solid State ◽  
Kinetic Study ◽  
Solid State Fermentation ◽  
Sulfonic Acid ◽  
Room Temperature ◽  
Maximum Activity ◽  
Cold Temperatures ◽  
Fermentation Method ◽  
Optimum Ph ◽  
Kinetics Of

Crude laccase was produced by using the fermentation method of solid state fermentation and employed fungus Marasmius sp and rice straw as support media. The kinetics of laccase was investigated by using the substrate of 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Laccase exhibits the maximum activity (Vm) of 1.45 mM/min and Michaelis-Menten (Km) constant value of 4.11 mM. The effect of pH and temperature has also been evaluated. The results showed that this enzyme had an optimum pH of 4.6 and temperature of 60 °C. Decreased stability of laccases is found to be faster when stored at room temperature than cold temperatures.

Investigation of thermal annealing by gamma irradiation at room temperature in LiNbO3 crystals

2001 ◽  
Author(s):  
Andrzej L. Bajor ◽  
Slawomir M. Kaczmarek ◽  
Izabella Pracka ◽  
Marek Swirkowicz ◽  
Teresa Wronska
Keyword(s):  
Gamma Irradiation ◽  
Thermal Annealing ◽  
Room Temperature

On N-acetylcysteine. Part II. Oxidation of N-acetylcysteine by hydrogen peroxide: kinetic study of the overall process

1994 ◽  
Vol 72 (10) ◽  
pp. 2102-2107 ◽  
Author(s):  
Zohreh Abedinzadeh ◽  
Jlil Arroub ◽  
Monique Gardès-Albert
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Study ◽  
Oxidation Kinetics ◽  
Reaction Mechanisms ◽  
Kinetic Data ◽  
Concentration Ratio ◽  
Low Concentration ◽  
Neutral Ph ◽  
Kinetics Of ◽  
Concentration Ratios

The oxidation kinetics of N-acetylcysteine (RSH) by hydrogen peroxide has been studied at neutral pH at different concentration ratios from 0.2 to 20 (4 × 10−4 mol L−1 ≤ [RSH]0 ≤ 2 × 10−2 mol L−1, 10−4 mol L−1 ≤ [H2O2]0 ≤ 10−2 mol L−1). In all the cases studied, N-acetylcystine (RSSR) is the only oxidized product formed. Our kinetic data have focused on the importance of the concentration ratio to reach the stoichiometric oxidation of N-acetylcysteine by hydrogen peroxide. Indeed non-stoichiometric oxidation of RSH occurs at relatively low concentration ratios (R < 2.5) whereas stoichiometric oxidation is observed when R > 2.5. Moreover, it has been shown that in the first minutes of the reaction there is the formation of a complex between RSH and H2O2, the stoichiometry of the complex being RSH concentration-dependent for a given R (R > 2.5). Reaction mechanisms have been quantitatively established and the k values of each step determined.

scholarly journals Effect of gamma irradiation on NaVO3 in polycrystalline solid state

2020 ◽  
Vol 2 (1) ◽  
pp. 124-131
Author(s):  
Ana Neacsu ◽  
◽  
Adina-Elena Stanciu ◽  
Mihail Contineanu ◽  
Daniela Gheorghe ◽  
...  
Keyword(s):  
Solid State ◽  
Gamma Irradiation ◽  
Polycrystalline Solid

scholarly journals False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

2016 ◽  
Vol 7 ◽  
pp. 1434-1446 ◽  
Author(s):  
Anastassia Kanavarioti
Keyword(s):  
Solid State ◽  
Dna Sequencing ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Degradation Products ◽  
False Positives ◽  
False Negatives ◽  
Base Calling ◽  
Alpha Hemolysin ◽  
Kinetics Of

Osmium tetroxide 2,2’-bipyridine (OsBp) is known to react with pyrimidines in ssDNA and preferentially label deoxythymine (T) over deoxycytosine (C). The product, osmylated DNA, was proposed as a surrogate for nanopore-based DNA sequencing due to OsBp’s “perfect” label attributes. Osmylated deoxyoligos translocate unassisted and measurably slow via sub-2 nm SiN solid-state nanopores, as well as via the alpha-hemolysin (α-HL) pore. Both nanopores discriminate clearly between osmylated and intact nucleobase; α-HL was also shown to discriminate between osmylated T and osmylated C. Experiments presented here confirm that the kinetics of osmylation are comparable for short oligos and long ssDNA and show that pyrimidine osmylation is practically complete in two hours at room temperature with less than 15 mM OsBp. Under the proposed labeling conditions: deoxyoligo backbone degradation measures less than 1/1,000,000; false positives such as osmylated deoxyadenine (A) and osmylated deoxyguanine (G) measure less than 1/100,000; false negatives, i.e., unosmylated C measure less than 1/10,000; and unosmylated T must measure substantially lower than 1/10,000 due to the 27-fold higher reactivity of T compared to C. However, osmylated C undergoes degradation that amounts to about 1–2% for the duration of the labeling protocol. This degradation may be further characterized, possibly suppressed, and the properties of the degradation products via nanopore translocation can be evaluated to assure base calling quality in a DNA sequencing effort.

A Kinetic Study of the Oxidative Addition of Substituted Benzenethiols Towards trans-Halocarbonylbis(triphenylphosphine)iridium(I)

1972 ◽  
Vol 50 (12) ◽  
pp. 1868-1873 ◽  
Author(s):  
J. R. Gaylor ◽  
C. V. Senoff
Keyword(s):  
Kinetic Study ◽  
Kinetic Data ◽  
Spectroscopic Data ◽  
Oxidative Addition ◽  
Second Order ◽  
Rate Of Reaction ◽  
Inductive Effects ◽  
Principal Factors ◽  
Kinetics Of ◽  
Activated Complex

The kinetics of the oxidative addition of a series of para-substituted benzenethiols, HSC6H4Y, where Y = 4-NO2, 4-Br, 4-Cl, 4-F, 4-H, 4-CH3, or 4-CH3O towards the complexes, trans-IrX(CO)(Ph3P)2 where X = Cl, Br, or I have been studied in benzene between 15 and 45°. These reactions follow simple second order kinetics, rate = k2[IrX(CO)(Ph3P)2][HSC6H4Y]. The two principal factors which influence the rates of these reactions are the mesomeric and inductive effects of the para-substituent and the nature of the ligand, X, coordinated to iridium. The rate of reaction increases as the substituent becomes more electron withdrawing and as X varies from Cl to Br to I. The kinetic data together with spectroscopic data (i.r. and n.m.r.) suggest that oxidative addition proceeds via a three-centered activated complex to give the cis-product.

scholarly journals Kinetics of MgWO4 Formation in the Solid State Reaction between MgO and WO3

1976 ◽  
Vol 31 (6) ◽  
pp. 619-621 ◽  
Author(s):  
Giorgio Flor ◽  
Riccardo Riccardi
Keyword(s):  
Solid State ◽  
Kinetic Study ◽  
Single Crystals ◽  
Solid State Reaction ◽  
Argon Atmosphere ◽  
Conductivity Measurements ◽  
Linear Rate ◽  
Rate Law ◽  
Temperature Range ◽  
Kinetics Of

The solid state reaction of MgWO4 formation from MgO (single crystals) and WO3 was investigated in the temperature range 800 - 985 °C under both air and argon atmosphere.The techniques employed for the kinetic study (contact and thermogravimetric methods) allowed to point out that the process follows the linear rate law in the early stages and the parabolic one in the subsequent stages.From inert marker experiments, kinetic determinations under the two different atmospheres and conductivity measurements, it was possible to state that the reaction is governed by a cation counterdiffusion mechanism

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (03) ◽  
pp. 100-103 ◽  
Author(s):  
C. Schümichen ◽  
J. Waiden ◽  
G. Hoffmann
Keyword(s):  
Glomerular Filtration ◽  
Renal Clearance ◽  
Plasma Protein ◽  
Kinetic Data ◽  
Adult Rats ◽  
Compound A ◽  
Extravascular Space ◽  
Tubular Cells ◽  
Glomerular Filtrate ◽  
Kinetics Of

SummaryThe kinetic data of two different 99mTc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 5 1Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells.

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