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A series of copper and zinc mixed oxides composed of equimolar ratio and treated with 0.05 Al 2 O 3 /mol catalyst has been prepared by coprecipitation method using their nitrates in presence of 1 M NaOH solution. The precipitation was carried out at a pH 9.5 and 50 • C. The results revealed that the bulk of various solids consisted of CuO and ZnO having ratios varying between 0.84 and 0.98. On the other hand, the values of surface concentrations of copper and zinc were bigger than those present in the bulk. The values of surface Cu/Zn ratio varied between 1.04 and 1.46 depending on the mode of preparation and calcination conditions. The mixed solids existed as nanocrystalline CuO and ZnO phases. The surface characteristics are strongly dependent on mode of coprecipitation and calcination temperature. The computed S BET values varied between 146 and 23 m 2 /g depending on mode of coprecipitation and calcination temperature. The increase of calcination temperature of different adsorbents within 300-400 • C led to a significant progressive decrease in the BET-surface area with subsequent increase in the values of mean pore radius. All adsorbents are mesoporous solids. All prepared solids showed a good catalytic activity in CO oxidation by O 2 , which proceeds via first order kinetics in all cases. The activation energy of the catalysed reaction was determined for various solids and the computed values were very small indicating the big catalytic activity of the investigated solids.On a préparé une série d'oxydes mixtes de cuivre et de zinc composés d'un rapportéquimolaire et traités avec un catalyseur de 0,05 Al 2 O 3 /mol par la méthode de la coprécipitation en utilisant leurs nitrates en présence de 1 M de solution de NaOH. La précipitation s'est effectuéeà un pH de 9,5 età une température de 50 • C. Les résultats ont révélé que la majeure partie de divers solides consistait en du CuO et du ZnO selon des rapports variant entre 0,84 et 0,98. D'un autre côté, les valeurs des concentrations superficielles de cuivre et de zincétaient supérieuresà celles présentes dans ce lot de solides. Les valeurs du rapport superficiel Cu/Zn variaient entre 1,04 et 1,46 selon le mode de préparation et les conditions de calcination. Les solides mixtes existaient sous forme de phases nanocrystallines du CuO et du ZnO. Les caractéristiques superficielles dépendent fortement du mode de coprécipitation et de la température de calcination. Les valeurs S BET calculées variaient entre 146 et 23 m 2 /g selon le mode de coprécipitation et la température de calcination. L'augmentation de la température de calcination de différents agents d'adsorption dans les limites de 300 et 400 • C a menéà une diminution progressive importante de l'aire superficielle BET, de même qu'une augmentation ultérieure des valeurs du rayon moyen des pores. Tous les agents d'adsorption sont des solides mésoporeux. Tous les solides préparés ont montré une bonne activité catalytique dans l'oxydation du CO par l'O 2 , qui suit une cinétique du premier ordre dans tous le...

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Effect of some amino phosphonates, in simulated conditions on crystallization rates of calcium oxalate monohydrate crystals (COM) was studied .In the absence of additives , it was found that, the rates of crystallization of prepared COM crystals, were directly proportional to the pH values of medium and inversely proportional to ionic strength of medium. The order of reaction was equal nearly to two and activation energy was 0.144 KJ/mol. In the presence of additives A1,A2,A3,A4 and A5, it was found they were inhibited the rates of crystallization of COM seed crystals through adsorption on the surface of the crystals. Langmuir isotherm can be applied and the calculated KL values in the presence of (A1,A2,A3,A4 and A5) were (12.5 x 10 5 , 11 x 10 5 , 7 x 10 5 , 4.167 x 10 5 , 1.714 x 10 5 ) J/mol respectively indicating strong inhibitory effects of these additives. The values of ΔG in the presence of these additives were ` ( -40.4, -40.0, -39.0,-38.5,-38.2) respectively. Crystallization of prepared COM crystals in presence of 10 -7 mol dm -3 of A1 ,indicated the adsorption of molecules of A1 on both kink and terrace sites , but favored kink sites. The percentage of total surface covered by molecules of A1 additive was 25.6 % which supported the surface-controlled mechanism. These synthesized compounds A1,A2,A3,A4 and A5, were screened for their in vitro antibacterial activity against both Gram positive and Gram negative bacteria. A1 compound showed moderate sensitivity on staph.aureus with slightly activity on klebsiella pneumon.

Exposure of Calcium phosphate affected the entomopathogenic nematode Heterorhabditis sp. differently. Survival, infectivity and penetration efficiency of Heterorhabditis sp. ((HPS1, HPS2 and HPS3) were affected by Calcium phosphate. At medium concentration (1M) of Calcium phosphate the affect on survival of Heterorhabditis sp (HPS1, HPS2 and HPS3) were 68.3, 30.2 and 33.5%, respectively. Calcium phosphate (0.2M and 2M) were less effective on survival of the three nematode strains (8.02to12.2%) and ( 2.02 to 14.6%), respectively. Entomopathogenic nematodes (HPS2) when used alone or mixed by low concentration (0.2M) unaffected on infectivity of Galleria mellonella (100%), but medium concentration affected the infectivity of G. mellonella . The penetration rate of nematode alone was better than from the nematode mixed with Calcium phosphate. Calcium phosphate at three concentrations also reduced the penetration efficiency of nematodes (HPS1, HPS2 and HPS3) (29.8, 32.7 and 27.9%) for three concentrations, respectively.