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  • Author or Editor: M. Amer x
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Abstract  

Radon has been recognized to be one of the major contributors to the natural radiation causing even lung cancer if it is present at enhanced levels. Its monitoring at highly confined locations such as underground caves, mines and tube-wells is very essential for finding the health related hazards among the workers. This paper reports the investigations of the levels of radon, thoron and their progeny monitored in the tube-wells of the Halls of residence at A.M.U., Aligarh, which lies in the subtropical region of Indo-Gangetic plains situated in North India. The twin cup dosimeters were fixed for exposure at a depth of 5–35 feet with a difference of 5 feet from the ground surface. The values of radon and thoron concentrations were found to vary from 6.58 to 1218.57 and 7.41–3226.61 Bq m−3, respectively. The preliminary results of this study for ‘bare mode’ detectors have been separately published and compared with the recent data.

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The direct toxicity of two essential oils,Majorana hortensis,Moench and Rosmarinus officinalis L.to adult females of the predacious mites,Amblyseius zaheri Yousef and El-Borolossy,Amblyseius barkeri (Hughes)and Typhlodromus athiasae Porath and Swirski were tested.Rosemary oil was the most toxic to fe- males of A.barkeri and the least to A.zaheri.In contrast,sweet marjoram oil was relatively toxic to T.athiasae and slightly toxic to A.barkeri.Both essential oils,decreased the food consumption rate at the concentration used for A.barkeri and A.zaheri.Females of A.barkeri and A.zaheri suffered a depression in reproduction when treated with 1% of rosemary oil.Both material used seems to be harmless to T.athiasae at 1%.

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The direct toxicity of four essential oils, Majorana hortensis Moench, Ros­marinus officinalis L., Mentha piperita L. and Lavandula officinalis Chaix, to adult females of the predacious mite Amblyseius swirskii Athias-Henriot were tested. Peppermint oil was the most toxic to females A. swiriskii while the French lavender oil was the least toxic to the pre­dator. All essential oils, at the two concentrations used, decreased the food consumption rate as well as egg laying. All four materials tested, at con­cen­tration 0.25% were considered to be safe for the predator since no mortalities had been recorded.

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The direct toxicity of the essential oil, Ocimum basilicum L. to females of six species of predacious mites of the family phytoseiidae was tested. The phytoseiid mites tested namely, Typhlodromus athiasae Porath and Swirski, Euseius yousefi Zaher and El-Borolossy, Amblyseius zaheri Yousef and El-Borolossy, Amblyseius deleoni (Muma and Denmark), Amblyseius swirskii Athias-Henriot and Amblyseius barkeri (Hughes). Sweet basil oil was highly toxic to females E. yousefi and was relatively intoxic to females A. swirskii. The essential oil has a close toxic effect for predator species, T. athiasae and A. barkeri. With the exception of A. zaheri, females of all predacious mites tested suffered a depression in reproduction and food consumption when treated with sweet basil oil at conc. 2%.

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The direct toxicity of the essential oil Lavendula officinalis Chais to egg stage and adult females of the predacious mites, Euseius yousefi Zaher and El-Borolossy, Neoseiulus barkeri (hughes), Amblyseius zaheri Yousef and El-Borolossy and Typhlodromus athiase Porth and Swirski was studied. French Lavender oil was highly toxic to both stages of E. yousefi and relatively in toxic to T. athiase. A depression on consumption was recorded on A. zaheri and E. yousefi, while a depression on reproduction was reported only in case of E. yousefi, when females treated with LC25 concentration. French Lavender oil, at concentration of (LC25) was considered to be safe for A. zaheri, N. barkeri and T. athiase, since no mortalities had been recorded.

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Thermal analysis of pharmaceutical compounds

IV. Evaluation of sulphonamides by thermal analysis

Journal of Thermal Analysis and Calorimetry
Authors: Fatma I. Khattab, M. M. Amer and Nagiba Y. M. Hassan

Some sulphonamides are evaluated by means of thermal analysis. Use is made of their characteristic endothermic DTA peaks (melting peaks), where the area changes linearly with variations in the amount of sulphonamides. The method is suitable for the determination of 30–100 mg of sulphathiazole, sulphisomidine, sulphaguanidine, sulphacetamide sodium and sulphamethoxypyridazine with reasonable accuracy. As for sulphisoxazole, two peaks are used for its determination: an endothermic one to determine 30–100 mg, and an exothermic one to determine 6–30 mg.

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Thermal analysis of pharmaceutical compounds

III. Characterization of sulphonamides by thermal analysis

Journal of Thermal Analysis and Calorimetry
Authors: F. I. Khattab, N. Y. M. Hassan and M. M. Amer

Fourteen sulphonamides have been thermally analyzed using thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). Their thermal reactions and stabilities have been thoroughly studied. It was found that the sulphonamides are first transformed into sulphanilamide. The melting points of these sulphonamides have been determined through their DTA curves and by the Kofler microscope, the results agreeing with those reported in the literature. The amount of water of crystallization has been calculated from the TG and DTG curves. Analysis of mixtures of some sulphonamides has been achieved by thermal analysis and by thin-layer chromatography using different solvent systems.

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