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Search Results: 1 - 10 of 13186 matches for " EL-HALLAG "
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ELECTROCHEMICAL STUDIES AND EXTRACTION OF CHEMICAL AND ELECTROCHEMICAL PARAMETERS OF ZN(II) ION AT MERCURY ELECTRODE VIA CONVOLUTIVE VOLTAMMETRY AND DIGITAL SIMULATION METHODS
EL-HALLAG,I. S;
Journal of the Chilean Chemical Society , 2010, DOI: 10.4067/S0717-97072010000300023
Abstract: the electrochemical behaviour of zn(ii) ion as example of creveirr system was studied at hanging mercury drop electrode in aqueous solution in the presence of im kcl using cyclic voltammetry and convolutive voltammetry methods. digital simulation technique was used to test the chemical and electrochemical parameters of zn(ii) ion estimated experimentally as well as verifying the proposed electrode mechanism.
Cyclic voltammetry, convolutive voltammetry, chronopotentiometry and digital simulation studies of [Pt(C≡C tol)2(dppm)2Ir(CO)2]+PF 6 complex
El-Hallag S. Ibrahim
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0380-3
Abstract: The electrochemical behaviour of the heterobimetallic complex [Pt(C≡C tol)2(dppm)2-Ir(CO)2]+PF 6 was studied via cyclic voltammetry, convolutive voltammetry and chronopotentiometry at glassy carbon electrode in dichloromethane solution. The electrochemical parameters calculated from experimental data were tested and confirmed by matching the experimental cyclic voltammograms with the simulated data. It was found that convolutive voltammetry provided higher sensitivity, better resolution and more accurate method for determination of the electrochemical parameters than ordinary cyclic voltammetry.
ELECTROCHEMICAL STUDIES AND EXTRACTION OF CHEMICAL AND ELECTROCHEMICAL PARAMETERS OF ZN(II) ION AT MERCURY ELECTRODE VIA CONVOLUTIVE VOLTAMMETRY AND DIGITAL SIMULATION METHODS
I. S EL-HALLAG
Journal of the Chilean Chemical Society , 2010,
Abstract: The electrochemical behaviour of Zn(II) ion as example of CrevEirr system was studied at hanging mercury drop electrode in aqueous solution in the presence of IM KCl using cyclic voltammetry and convolutive voltammetry methods. Digital simulation technique was used to test the chemical and electrochemical parameters of Zn(II) ion estimated experimentally as well as verifying the proposed electrode mechanism.
ELECTROCHEMICAL OXIDATION OF IODIDE AT A GLASSY CARBON ELECTRODE IN METHYLENE CHLORIDE AT VARIOUS TEMPERATURES
EL-HALLAG,I.S;
Journal of the Chilean Chemical Society , 2010, DOI: 10.4067/S0717-97072010000100016
Abstract: anodic electrooxidation of iodide in 0.1 mol l-1 tbap/ ch2c12 was studied electrochemically via cyclic voltammetry, convolution transforms voltammetry, chronoamperometry and chronopotentiometry techniques at a glassy carbon electrode (gce) at various temperatures ranging from -20 °c to 21 °c. it was found that at less positive potential triiodide (i-3) is formed followed by a moderate fast chemical process, while at more positive potential, the triiodide is oxidized to iodine (i2) followed by another chemical process, i.e ec1ec2 scheme. the effect of lowering the temperature on the heterogeneous electron transfer rate constant and the diffusion coefficient was discussed. the relevant chemical and electrochemical parameters of the electrode reaction were determined. the accurate test of the parameters evaluated experimentally was verified by comparing the experimental voltammograms with the simulated one.
ELECTROCHEMICAL OXIDATION OF IODIDE AT A GLASSY CARBON ELECTRODE IN METHYLENE CHLORIDE AT VARIOUS TEMPERATURES
I.S EL-HALLAG
Journal of the Chilean Chemical Society , 2010,
Abstract: Anodic electrooxidation of iodide in 0.1 mol L-1 TBAP/ CH2C1(2) was studied electrochemically via cyclic voltammetry, convolution transforms voltammetry, chronoamperometry and chronopotentiometry techniques at a glassy carbon electrode (GCE) at various temperatures ranging from -20 °C to 21 °C. It was found that at less positive potential triiodide (I-3) is formed followed by a moderate fast chemical process, while at more positive potential, the triiodide is oxidized to iodine (I2) followed by another chemical process, i.e EC1EC2 scheme. The effect of lowering the temperature on the heterogeneous electron transfer rate constant and the diffusion coefficient was discussed. The relevant chemical and electrochemical parameters of the electrode reaction were determined. The accurate test of the parameters evaluated experimentally was verified by comparing the experimental voltammograms with the simulated one.
Electrochemical behavior of hexamethylbenzene isocloso ruthenium-borane complex at a glassy carbon electrode in non-aqueous medium
Ghoneim, M. M.;El-Hallag, I. S.;
Journal of the Brazilian Chemical Society , 2010, DOI: 10.1590/S0103-50532010000100003
Abstract: electrochemical behavior of hexamethylbenzene isocloso ruthenium-borane complex [(c6me6)-isocloso-1-rub9 h9] was investigated at a glassy carbon electrode in 0.1 mol l-1 tetrabutyl ammonium perchlorate dissolved in methylene chloride, at - 20 oc < t < 21 oc using convolutive cyclic voltammetry, chronoamperometry and chronopotentiometry techniques. the chemical and electrochemical parameters of the investigated complex have been determined and confirmed via digital simulation method. low-temperature diffusion coefficient and heterogeneous electron transfer kinetics of the complex [(c6me6)-isocloso-1-rub9 h9] were reported. on the basis of the obtained data, the electrode reaction of the complex [(c6me6)-isocloso-1-rub9 h9] was suggested and discussed.
ELECTROCHEMICAL INVESTIGATION OF CYSTEAMINE AT CARBON FIBER MICRODISK ELECTRODE
IS EL-HALLAG,A.O AL-YOUBI,A.Y OBAID,E.H EL-MOSSALAMY
Journal of the Chilean Chemical Society , 2011,
Abstract: The electrooxidation of cysteamine compound was carried out using convolutive cyclic voltammetry, linear sweep voltammetry and chronoamperomtry techniques at a carbon fiber microdisk electrode in 0. 1 M perchloric acid. The electrooxidation potential (E0'' ) of cysteamine occurs at + 0.921 V. The mechanistic pathway of electrooxidation process at carbon fiber microelectrode is loss of 1 electron per molecule. The electrode process is controlled mainly by diffusion. The chemical and electrochemical parameters of the investigated system were determined experimentally and verified theoretically via digital simulation method.
ELECTROCHEMICAL INVESTIGATION OF CYSTEAMINE AT CARBON FIBER MICRODISK ELECTRODE
EL-HALLAG,IS; AL-YOUBI,A.O; OBAID,A.Y; EL-MOSSALAMY,E.H; EL-DALY,S.A; ASIRI,A.M;
Journal of the Chilean Chemical Society , 2011, DOI: 10.4067/S0717-97072011000400003
Abstract: the electrooxidation of cysteamine compound was carried out using convolutive cyclic voltammetry, linear sweep voltammetry and chronoamperomtry techniques at a carbon fiber microdisk electrode in 0. 1 m perchloric acid. the electrooxidation potential (e0'' ) of cysteamine occurs at + 0.921 v. the mechanistic pathway of electrooxidation process at carbon fiber microelectrode is loss of 1 electron per molecule. the electrode process is controlled mainly by diffusion. the chemical and electrochemical parameters of the investigated system were determined experimentally and verified theoretically via digital simulation method.
Effect of the Number and Orientation of Fractures on the P-Wave Velocity Diminution: Application on the Building Stones of the Rabat Area (Morocco)  [PDF]
Hamid El Azhari, Iz-Eddine El Amrani El Hassani
Geomaterials (GM) , 2013, DOI: 10.4236/gm.2013.33010
Abstract: This study is focused on two types of Moroccan rocks, among the most widely used as building stones: the calcarenite of Salé (CS) and the marble of oued Akrech (MA). The two rocks, lithologically different, show a clear contrast of their P-wave velocities (Vp): 3.90 vs 5.10 km/s at dry state and 4.29 vs 5.64 km/s at saturation. The “Artificial fractures” created in the two rock types reveal that their Vp undergo diminutions which the rates vary depending of the number and the plane orientation of the fractures. In the CS, Vp shows an increasing of cumulative diminution (Dc) according to the number of fractures, but with a variable rate of unitary diminution (Du) from one fracture to the other. This defines a linear regression with a low coefficient of determination (Dc = 10.18NbFr + 10.96; r2 = 0.87). The mode of the Vp evolution would be related to the roughness of fractures surface, which itself depends upon the petrographic nature of the calcarenite (friable structure, high porosity and heterogenous composition). The MA manifested an increasing Dc with a fairly constant rate of Du from a fracture to another, giving a regression line with a high coefficient of determination (Dc = 12.17NbFr10.69; r2 = 0.99). This steady diminution of Vp would be related to the granoblastic texture and the monomineral composition of the marble, which engender smoother fracture surfaces. The rates of Vp diminution also depend on the orientation plane of the fractures relative to the direction of wave propagation. The fractures parallel (θ = 0°) amplify slightly the Vp, playing a significant role of “waveguide”. The fractures oriented at 45° lead to a diminution lower than those of fractures oriented at 25° and 90°. The same trend of diminution, but at variable rates, appears on the samples of the two types of stones at dry and saturated state. This can be explained by the compressive nature of P-waves, which obey the physic laws of the transmission of the constraints in the solid mediums.
Waterlogging in the New Reclaimed Areas Northeast El Fayoum, Western Desert, Egypt, Reasons and Solutions  [PDF]
El Sayed Ali El Abd, Maged Mostafa El Osta
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.618147
Abstract: The waterlogging in the new reclaimed areas has become a major concern in the area Northeast El Fayoum, Western Desert, Egypt. It is not only endangering the structures and properties but also causing major environmental problem affecting the health of the area, habitats, and the biotic of the land community, as well as the deteriorating of Egypt’s Pharaonic monuments (El Lahun and Hawarah pyramids). Both the daily seepage from excess irrigation water and the presence of impervious clay or limestone beds at shallow depths may represent the main contributor of ground-water rising in the shallow aquifer. This paper investigates the interplay of the hydrogeological characteristics, soil properties and recent land reclamation projects on the distribution of waterlogging and salinization within the study area. The field observations show that new reclaimed areas have been recently cultivated in distant areas from the old agricultural land. These new cultivations have developed widespread waterlogging, soil salinization and deterioration of Egypt’s Pharaonic monuments as a result of rising groundwater related problems. In this paper, the data used come from database of drillings for eleven observation wells distributed inside the whole area to measure periodic water levels. The soil litho-units are mainly composed of coarse sand, sandy clay, silt and fractured limestone underlined by impervious clay or limestone, thus limiting the downward percolation of excess irrigation water and therefore develops waterlogging. The drainage networks and suitable irrigation methods have to be considered when planning for a new cultivation in dry land to better control waterlogging and salinization hazard. It is highly recommended in this research that newly small and deep cut drainage canals network should be constructed and connected to the master drainage canal to dewater the excess irrigation water and to prevent the waterlogging in the concerned area.
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