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1.
Hamad?M.?Al-MatarEmail author Sayed?M.?Badawy 《Journal of the American Society for Mass Spectrometry》2005,16(8):1311-1315
Mass spectra of the methylated [60]fullerenes were obtained by EI mass spectrometry using “desorption” or “in-beam” technique.
The mass spectra of the methylated fullerenes, C60Men, have the molecular ion peak M+ indicating that the product is stable under the MS (EI) conditions. The appearance of an intense peak at m/z 360 was assigned to the formation of fullerene dication C60++. The remaining peaks were assigned to successive loss of methyl groups from molecular monocation and dication. 相似文献
2.
A hydralazine ion-selective PVC membrane electrode based on hydralazinium tetraphenylborate has been prepared with dioctyl phthalate as plasticizer. The electrode showed linear response with a slope factor of 57.5 mV/concentration decade at 20 degrees over the concentration range from 4 x 10(-4) to 10(-1)M hydralazine. The effects, on the electrode performance, of membrane composition, pH of the test solution and the time of soaking were studied. The electrode exhibited good selectivity for hydralazine with respect to a large number of inorganic cations and organic substances of biological importance. The standard-addition method and potentiometric titrations were used to determine hydralazine concentrations in pure solutions and in a pharmaceutical preparation, with satisfactory results. 相似文献
3.
Badawy SM 《European journal of mass spectrometry (Chichester, England)》2004,10(5):613-617
The application of low-temperature pyrolysis mass spectrometry to the identification of some commercial and synthetic polymers using a direct insertion probe and electron ionization has been studied. The polymers were analyzed directly in the solid probe of a mass spectrometer within the ion source at 70 eV electron impact. The quadrupole mass spectrometer, equipped with a gas chromatogram software and library of low molecular weight compounds, was used to characterize the polymers by measuring the chemical structure of the repeat units and the end groups, and to examine the thermal degradation pathways. The polymers investigated show different degradation pathways. Investigation of sequences and determination of composition of copolymers were studied. Total ion pyrogram and spectrum subtractions were used to separate and measure spectra of pyrolysis steps at distinctly different temperatures. 相似文献
4.
5.
Wael M. Badawy Octavian G. Duliu Marina V. Frontasyeva Hussein El Samman Arnaud Faanhof 《Isotopes in environmental and health studies》2018,54(5):535-547
The activity concentrations of natural 40K, 232Th, and 238U in 89 soil and 84 sediment samples collected over the entire Egyptian Nile River basin including the Nile delta are reported based on the results of epithermal neutron activation analysis. The average activity concentrations of 40K, 232Th, and 238U equal to 15.3?±?6.6, 15.6?±?11.1 and 220?±?31 Bq/kg, respectively, are significantly lower than those reported for the Upper Continental Crust, World Average Sediments as well as World Average Soils, suggesting the presence of a considerable portion of mafic material, most probably originating from the Ethiopian High Plateau. Their average activity concentrations are statistically the same in soil and sediments, indicating that the Nile sediments and soil material are of the same origin. The main goal of this study was not only to estimate the radiological hazards but also to show the influence of sedimentary material transportable by the Blue Nile from the Ethiopian High Plateau. The different hazard indices like the radium equivalent, gamma index, external hazard as well as the internal hazard show a low radiological exposure either on direct contact or if local mud bricks are used in the construction of dwellings. 相似文献
6.
The adsorption of Cu(II) and Cr(III) ions by pure clay mineral, vermiculite, was examined in aqueous solution with respect
to the adsorbent dose, initial metal ion concentration, pH, and contact time. The studies showed that vermiculite can be used
as an adsorbent material for the moderate removal of Cr(III) and Cu(II) from aqueous solutions. Lagergren first-order, pseudo-second-order,
and intraparticle diffusion models were used to describe the kinetic data. The kinetics of adsorption indicates that the process
fitted well the intraparticle diffusion model. 相似文献
7.
8.
O. E. Badawy M. El-Nadi S. A. El-Sharkawy M. K. Hegab M. M. Sherif 《Zeitschrift für Physik A Hadrons and Nuclei》1983,311(1-2):105-112
An analysis for 2,000 events produced by 2.1 GeV/c/n alpha particles in nuclear emulsion has been carried out. Multiplicity and angular distributions of charged secondaries have been measured and correlation among them are discussed. The presented data are compared with relevant values from proton and14N interactions with nuclei. The multiplicity distribution of showers has been tested by a modified independent nucleon-nucleus multiple scattering model (INAM) of reference [8], and by the model of reference [12]. 相似文献
9.
Ion-selective electrode for the determination of metoclopramide 总被引:2,自引:0,他引:2
10.
M.M. Badawy 《Polymer Testing》1996,15(6):507-515
The thermal properties (thermal conductivity λ, thermal diffusivity a, and specific heat Cp) as well as the dielectric constant ε′ and dielectric loss ε′ of conductive styrene butadiene rubber loaded with different concentrations of sulphur were measured. It was found that both λ and Cp increase gradually at around 1 phr of sulphur content. Meanwhile, the dielectric constant ε′, showed a pronounced peak at 2 phr of sulphur content. Moreover, the effect of hydrostatic pressure on the dielectric constant ε′ and dielectric loss ε′ was found to rise with pre-compression. 相似文献