Rabie S. Farag

Speciation of organotin compounds in sediments of semi-closed areas along the Mediterranean coast of Alexandria

Organotin compounds were measured in sediments of four different semi-closed areas of the Mediterranean coast of Alexandria: the Eastern Harbour, Western Harbour, El-Max Bay, and Abu-Qir Bay. Due to the commercial trade activity inside the Western Harbour, in addition to the effect of wastes discharged from El Noubaria canal, it shows the highest concentrations of total tin (6.34 μg g−1 dry weight), dibutyl tin (1.63 μg g−1 wet weight), tributyl tin (0.33 μg g−1 wet weight) and diphenyl tin (1.06 μg g−1 wet weight) compared with other locations. The concentrations of TBT species showed the highest contents compared with DBT and DPhT compounds in all sampling areas. This trend might be due to the worldwide use of TBT not only as biocides in antifouling paints but also as preserving agents for wood, fungicides in agricultural activities, and heat and UV stabilizers of PVC, which results in a direct release of TBT into the water body, accumulation in aquatic fauna. There is also precipitation into sediments and a decrease in degradation rate into its derivatives. Variations, types, concentrations, and distribution of different organotin compounds are discussed in the areas under investigation. The study reveals a new record of organotin compounds along the Alexandria coast and makes comparisons with other surrounding areas of interest.

Some Physical Features of Glasses Synthesized from Some Environmental Wastes

New glasses based on wastes of limestone, phosphate, and cement kiln dust besides white sand were manufactured. The structure of the prepared glasses was studied by FTIR, thermal analysis, UV spectroscopy and ultrasonic techniques. The analysis revealed that increasing the content of SiO2 influences the concentrations of the structural units constituting the amorphous network. The values of the physical parameters; the density, ultrasonic velocity, the elastic moduli, the refractive index, the optical band gap and the glass transition temperature increase as the SiO2 content increases, which was attributed to the former role of SiO2 which strengthens the calcium borate network and the conversion of non-bridging oxygens into bridging oxygens. These factors increase the crosslink density and connectivity within the glass network and hence its rigidity.

Fabrication and physical characteristics of new glasses from wastes of limestone and phosphorite rocks

In this work, new glasses were synthesized from wastes of limestone and phosphate rocks besides commercial borax. The glasses were characterized by FTIR, DTA, ultrasonic techniques and UV spectroscopy. It was found that the concentration of both CaO and P2O5 increases and the concentrations of B2O3 and Na2O decrease as the content of phosphate rocks increases. Variation of the contents of the different oxides affects the concentration of the structural units constituting the glass, which was indicated by the behaviour of the fraction N4 of BO4 units in the borate matrix. The density and the refractive index of the glasses decrease as the CaO and P2O5 contents increase, which was attributed to the increase of [BO3] structural units. On the other hand, the physical parameters such as the ultrasonic velocity, the elastic moduli, the optical bandgap and the optical polarizability increased, which was attributed to the higher coordination number of CaO6 compared with the coordination of borate structural units and to the former effect of P2O5. As a result, a polymerization of the total co-ordination number of the glass, crosslink density and connectivity within the glass network will occur.

Preparation, Characterization and Antimicrobial Activity of Schiff Base of (E) - N - (4-(Thiophen-2-ylmethyleneamino) Phenylsulfonyl) Acetamide Metal Complexes

Department of Basic Science, Faculty of Engineering Science, Sinai University, North Sinai, Egypt Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129Torino, Italy Department of Chemistry, Faculty of Science, Taibah University, 41411-Al-Madinah, Saudi Arabia The Higher Institute of Optics Technology (HIOT), Heliopolis, 17361-Cairo, Egypt Department of Chemistry, Faculty of Science, Al-Azhar University, Cairo, Egypt Pharmaceutical and Medicinal Chemistry Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Cairo12622, Egypt