Comparative Bioreduction of Fe(III) with Geobacter metallireducens and Bacillus infernus

A comparative study on the Fe-reducing ability of pure anaerobic strains of Geobacter metallireducens and Bacillus infernus was investigated using different sources of Fe(III). Batch tests were carried out in aqueous solutions containing a reducing agent (lactate or formate) and at a constant temperature of 37°C and 50°C respectively. The formation of biogenic compounds of Fe(II) was determined using XRD and SEM-EDX techniques. The bioreduction of magnetite was not affected by the type of bacterial strain used. The kinetics of the process, initially very fast, stopped rapidly for both types of microorganisms. Vivianite (Fe3(PO4)2.8H2O) was detected as the main biogenic compound formed during the bioreduction process.

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Hygroscopic/Hydrolytic Kinetics of Two Bulk-fill Resin Composite Restorative Materials Stored in Different Media: An inVitro Comparative Study

Egyptian Dental Journal ◽

10.21608/edj.2018.79357 ◽

2018 ◽

Vol 64 (4) ◽

pp. 3823-3831

Author(s):

Nadia Zaghloul

Keyword(s):

Comparative Study ◽

Resin Composite ◽

Restorative Materials ◽

Kinetics Of

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Effects of salts on the kinetics of oxidation of alkenes by thallic salts in aqueous solutions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19810693 ◽

1981 ◽

Vol 46 (3) ◽

pp. 693-700 ◽

Cited By ~ 1

Author(s):

Milan Strašák ◽

Jaroslav Majer

Keyword(s):

Aqueous Solutions ◽

Phase Transfer ◽

Heterogeneous Reaction ◽

Qualitative Model ◽

Kinetic Effect ◽

Tetraalkylammonium Salts ◽

Reaction Conditions ◽

Kinetics Of Oxidation ◽

Kinetics Of ◽

Heterogeneous Reaction Conditions

The kinetics of oxidation of alkenes by thallic sulphate in aqueous solutions, involving the two reaction steps-the hydroxythallation and the dethallation - was studied, and the effect of salts on the kinetics was examined; this made it possible to specify more precisely the reaction mechanism and to suggest a qualitative model of the reaction coordinate. It was found that in homogeneous as well as in heterogeneous reaction conditions, the reaction can be accelerated appreciably by adding tetraalkylammonium salts. These salts not only operate as catalysts of the phase transfer, but also exert a significant kinetic effect, which can be explained with a simplification in terms of a stabilization of the transition state of the reaction.

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Preparation and Evaluation of Skeletal Cobalt-Molybdenum Hydrodesulfurization Catalysts

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19950568 ◽

1995 ◽

Vol 60 (4) ◽

pp. 568-575

Author(s):

Karel Sporka ◽

Jiří Hanika ◽

Vladimír Jůn

Keyword(s):

Aqueous Solutions ◽

Active Component ◽

Catalyst Activity ◽

Gas Oil ◽

Gamma Alumina ◽

Molybdenum Sulfides ◽

Hydrodesulfurization Catalysts ◽

Hds Catalysts ◽

Kinetics Of ◽

Preparation And Evaluation

Preparation of skeletal Co-Mo catalysts by controlled impregnation of aluminosilicate skeletons containing deposited gamma-alumina with aqueous solutions of active component precursors has been investigated. The activity of the laboratory catalysts in gas oil hydrodesulfurization has been determined. Kinetics of impregnation of skeletal supports, the effect of their type, and the dependence of catalyst activity on the content of cobalt and molybdenum sulfides are reported. HDS skeletal catalysts prepared were compared with the extruded types. It was found that skeletal HDS catalysts show the higher activity (related to the content of alumina and Co-Mo sulfides) than the extruded ones due to the less significant effect of internal diffusion. However, if the activity is related to the same volume of catalyst bed, the activity of skeletal catalysts is only one fourth of that of the extruded types.

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Study of potential oscillations during reaction of an aluminium single crystal with an aqueous KOH solution

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19900345 ◽

1990 ◽

Vol 55 (2) ◽

pp. 345-353 ◽

Cited By ~ 4

Author(s):

Ivan Halaša ◽

Milica Miadoková

Keyword(s):

Aqueous Solutions ◽

Single Crystal ◽

Single Crystals ◽

Periodic Potential ◽

Optimum Conditions ◽

Potential Oscillations ◽

Dilute Aqueous Solutions ◽

Experimental Findings ◽

Kinetics Of

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.

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Inactivation kinetics of Bacillus cereus vegetative cells and spores from different sources by antimicrobial photodynamic treatment (aPDT)

LWT ◽

10.1016/j.lwt.2021.111037 ◽

2021 ◽

Vol 142 ◽

pp. 111037

Author(s):

Leonardo do Prado-Silva ◽

Verônica O. Alvarenga ◽

Gilberto Ú.L. Braga ◽

Anderson S. Sant’Ana

Keyword(s):

Bacillus Cereus ◽

Inactivation Kinetics ◽

Photodynamic Treatment ◽

Vegetative Cells ◽

Kinetics Of ◽

Different Sources

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Comparative Study of Chemical Stability of Two H1Antihistaminic Drugs, Terfenadine and ItsIn VivoMetabolite Fexofenadine, Using LC-UV Methods

Journal of Analytical Methods in Chemistry ◽

10.1155/2019/5790404 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Anna Gumieniczek ◽

Anna Berecka-Rycerz ◽

Rafał Pietraś ◽

Izabela Kozak ◽

Karolina Lejwoda ◽

...

Keyword(s):

Comparative Study ◽

Chemical Stability ◽

First Order ◽

First Order Kinetics ◽

Kinetics Of Degradation ◽

Effects Of Temperature ◽

High Doses ◽

Antihistaminic Drugs ◽

Kinetics Of

A comparative study of chemical stability of terfenadine (TER) and itsin vivometabolite fexofenadine (FEX) was performed. Both TER and FEX were subjected to high temperature at different pH and UV/VIS light at different pH and then quantitatively analyzed using new validated LC-UV methods. These methods were used to monitor the degradation processes and to determine the kinetics of degradation for both the compounds. As far as the effects of temperature and pH were concerned, FEX occurred more sensitive to degradation than TER. As far as the effects of UV/VIS light and pH were concerned, the both drugs were similarly sensitive to high doses of light. Using all stress conditions, the processes of degradation of TER and FEX followed the first-order kinetics. The results obtained for these two antihistaminic drugs could be helpful in developing their new derivatives with higher activity and stability at the same time.

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