Analysis of Rates of Geochemical Reactions.- Transition State Theory and Molecular Orbital Calculations Applied to Rates and Reaction Mechanisms in Geochemical Kinetics.- The Mineral-Water Interface.- Kinetics of Sorption-Desorption.- Kinetics of Mineral Dissolution.- Data Fitting Techniques with Applications to Mineral Dissolution Kinetics.- Nucleation, Growth, and Aggregation of Mineral Phases: Mechanisms and Kinetic Controls.- Microbiological Controls on Geochemical Kinetics 1: Fundamentals and Case Study on Microbial Fe(III) Oxide Reduction.- Microbiological Controls on Geochemical Kinetics 2: Case Study on Microbial Oxidation of Metal Sulfide Minerals and Future Prospects.- Quantitative Approaches to Characterizing Natural Chemical Weathering Rates.- Geochemical Kinetics and Transport.- Isotope Geochemistry as a Tool for Deciphering Kinetics of Water-Rock Interaction.- Kinetics of Global Geochemical Cycles.

Kinetics of Water-Rock Interaction

Antimicrobial activity of metal-substituted cobalt ferrite nanoparticles synthesized by sol–gel technique

Therapeutic and diagnostic potential of nanomaterials for enhanced biomedical applications.

Synthesis and characterization of metals-substituted cobalt ferrite [Mx Co(1-x) Fe2O4; (M = Zn, Cu and Mn; x = 0 and 0.5)] nanoparticles as antimicrobial agents and sensors for Anagrelide determination in biological samples

Antibacterial, antibiofilm, and photocatalytic activities of metals-substituted spinel cobalt ferrite nanoparticles.

The synthesis and characterization of silver nanoparticles (AgNPs) using natural pigments from plants as reducing agents is presented in this study. The natural pigments were extracted from Alfalfa leaves. The reduction reaction was investigated by UV–Vis and FTIR analyses. The synthesized AgNPs were characterized by UV–Vis, XRD, TEM, and DLS. UV–Vis analysis revealed that AgNPs were produced with a persistent plasmonic absorption peak at about 418 nm accompanied by consumption of pigments. The reduction is suggested to occur, mainly, by chlorophyll a and carotenes. Characterization revealed pure synthesized AgNPs with an average particle size of 25 nm. In an interesting novel experiment, the progress of reduction reaction was traced at the interface between reacting phases under UV illumination making use of fluorescence of both chlorophylls and formed Ag nano-clusters (AgNCs). The enrollment of chlorophylls in reduction was suggested depending on FTIR and fluorescence analyses. The synthesized AgNPs possessed a superior antimicrobial activity towards Staphylococcus aureus ATCC 29213; 24.0 mm ZOI, followed by Escherichia coli ATCC 25922; 17.0 mm ZOI. In addition, AgNPs were a strong antifungal agent against Candida albicans ATCC 10231; 26.0 mm ZOI.

Synthesis of silver nanoparticles using natural pigments extracted from Alfalfa leaves and its use for antimicrobial activity

Spent nuclear fuel interim dry storage; Design requirements, most common methods, and evolution: A review

Wadi El Reddah, Egypt, is mostly enclosed by scattered exposure to the chronological sequence of a metavolcanic and metagabbro-diorite complex. There are radiological impacts due to internal and external exposure to the high natural background radiation caused by 226Ra, 232Th, and 40K in the Wadi El-Reddah stream sediments. 72 samples were collected and the activity concentration was measured using a NaI(Tl) gamma-spectroscopy system. The average activity concentration of 226Ra, 232Th and 40K was 215 ± 118 Bq kg−1, 131 ± 90 Bq kg−1 and 822 ± 125 Bq kg−1, respectively. Most of the studied samples had a higher activity concentration than the world average.

Natural radioactivity levels and radiological implications in the high natural radiation area of Wadi El Reddah, Egypt

This study aims to evaluate the specific activity levels in soil and shore-sediment samples due to natural radionuclides; 238U, 232Th and 40K, and man-made 137Cs of Al–Nigella site, Marsa Matrouh g...

Analysis of natural radionuclides and 137Cs using HPGe spectrometer and radiological hazards assessment for Al-Nigella site, Egypt

Abu Garadi area is mainly represented by metasediments, alkali feldspar granites and stream sediments. The granitic mass described different degrees of hydrothermal alterations like albitization, g...

A. F. Tawfic

Papers

Synthesis of silver nanoparticles using natural pigments extracted from Alfalfa leaves and its use for antimicrobial activity

Spent nuclear fuel interim dry storage; Design requirements, most common methods, and evolution: A review

Natural radioactivity levels and radiological implications in the high natural radiation area of Wadi El Reddah, Egypt

Analysis of natural radionuclides and 137Cs using HPGe spectrometer and radiological hazards assessment for Al-Nigella site, Egypt

Uranium-series disequilibrium as a tool for tracing uranium accumulation zone in altered granite rocks