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Antar Ahmed Abdelhamid

Assistant Professor - استاذ مساعد

Faculty of science

Address: Dr.

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Publications Which contain the keyword: Temperature


Some New Cr (III)  Mononuclear Complexes encompassing Tri- and Tetra-dentate Imine Ligands: Synthesis, Spectral Characterization and High Selectivity in Catalytic Oxidation of Benzyl alcohol
IN THE PRESENT CONTRIBUTION, SOME NOVEL CR (III) COMPLEXES WERE SYNTHESIZED FROM TRI- AND TETRA-DENTATE IMINE LIGANDS DERIVED FROM 3-ETHOXYSALICYLALDEHYDE OR 2-HYDROXYNAPHTHALDEHYDE WITH 2-AMINOPHENOL OR O-PHENYLENEDIAMINE. ALL THE PREPARED LIGANDS WERE AUTHENTICATED BY 1H, 13C NMR AND IR SPECTRA. INTERACTION OF THE SYNTHESIZED LIGANDS WITH CHROMIUM NITRATE PRODUCED THREE NOVEL CR(III) COMPLEXES. THE STRUCTURE OF THE PREPARED CR (III) COMPLEXES ... Read more

High Selectivity on The epoxidation of Cyclooctene Catalyzed by Tri-and Tetra-Dentate Imine Vanadyl Chelates Using H2O2
High yield of VO(II) chelates incorporating new imine ligands were obtained by the condensation reaction between 2-hydroxynaphthaldehyde or 3-ethoxysalicylaldehyde and o-phenylenediamine s in 1:1 molar ratio. All the complexes are non– hygroscopic in nature and stable to the atmosphere. The synthesized ligands and the isolated imine chelates have been characterized various physico-chemical techniques. The results obtained from these studies and ... Read more

Effect of changes in temperature on the force–frequency relationship in the heart of catfish (Clarias gariepinus)
An isometric ventricular preparation was used to investigate the effect of changes in temperature (10, 15, 20, 25 and 30 °C) on the cardiac contractility produced by increasing of frequency in the catfish heart. The ability of the ventricular preparation to develop the cardiac force at 10 °C continued regularly until a frequency of 1.0 Hz, whereas at 15, 20, ... Read more

Temperature dependence of cardiac sarcoplasmic reticulum and sarcolemma in the ventricle of catfish (Clarias gariepinus)
The present study was undertaken to examine the relative contribution of the SR-Ca2+release and sarcolemmal Ca2+ channels in developing the cardiac force at two different temperatures (20 and 30 °C) in the catfish (_Clarias gariepinus_). The sarcolemmal Ca2+ contribution of activator Ca2+ was greater at a test temperature of 30 °C as assessed by verapamil. Whereas the SR-Ca2+ contribution was ... Read more

2018-10-06 15:35:46 Keywords Life tree, Moringaceae, Sowing, Temperature,
Evaluation of seed germination and growth characteristics of Moringa oleifera and M. peregrina under laboratory, greenhouse and field conditions
This work aimed to evaluate production of Moringa peregrina and M. oleifera, in the central region of Saudi Arabia. Seed germination using seven temperature regimes in laboratory showed that 20°C is the optimum temperature for both species allowing the germination of 87-90% of cultivated seeds within 5 days, mainly from the fourth to seventh days of sowing. Satisfied germination (80%) ... Read more

Solvent Effects on The reactivity Trends of some Coumarin Derivatives
Kinetic results, rate laws and reaction mechanisms were established for the base hydrolysis of 7-hydroxycoumarin (HC), 7-hydroxycoumarin-4-acetic acid (HCA), 6-nitrocoumarin (NC), 6-nitrocoumarin-3-carboxylic acid (NCC), 7-dimethylamino-4-methylcoumarin (DMAC), 7-diethylamino-4-methylcoumarin (DEAC) and coumalic acid (COU) in aqueous solution, water-methanol and water-acetone mixtures. The kinetics of the base hydrolysis followed a rate law with kobs= k2[OH-] for all coumarin derivatives under study except 6-nitrocoumarin-3-carboxylic ... Read more

7.	The environmental factors affecting the archaeological buildings in Egypt, Part-I
There are many monumental sites and stone buildings distributed all over Egypt especially in the contemporaneous time. These sites and stone buildings suffer from several extrinsic and intrinsic factors of deterioration which could be divided into several effects such as air temperature, relative humidity, wind erosion and air pollution. All of these factors cause a great harmful appearance that results ... Read more

Reactivity Trends and Kinetic Inspection of Hydroxide Ion Attack and DNA Interaction on Some Pharmacologically Active Agents of Fe(II)  Complexes at Different Temperatures
The reactivity of few novel high‐spin Fe(II) complexes of Schiff base ligands derived from 2‐hydroxynaphthaldehyde and some variety of amino acids with the OH− ion has been examined in an aqueous mixture at the temperature range from 10 to 40°C. Based on the kinetic investigations, the rate law and a plausible mechanism were proposed and discussed. The general rate equation ... Read more

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