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- Author or Editor: M. El-Dessouky x
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Abstract
Neutron activation analysis is one of the most extensively used methods for environmental studies due to its high sensitivity, precision, versatility and multielemental character. Cement factories at Helwan, south of Cairo, contribute substantially to environmental pollution. Determination of minor and trace-elements in dust particulates from the cement industrial areas has been performed to assess the air quality from an environmental and human health point of view. Soil-7 standard reference material from IAEA and SRM-1571 from NBS were used for quality assurance testing. The data obtained indicate there is an indication that the pollution could be hazardous to people living in and around the area surveyed.
Abstract
Hydrogen and methane produced during the 
-radiolysis of 2-propanol have been measured in the absence and presence of 0.1 and 0.01 M ketone (1-(2-furanyl)-1-hexanone) at different doses. In the absence of ketone at 100 kGy, the hydrogen and methane yields were found to be G(H2)=5.1 and G(CH4)=2.02. At lower ketone concentrations the hydrogen and methane yields were G(H2)=4.35 and G(CH4)=1.83, while higher concentrations decreased the above values to G(H2)=2.95 and G(CH4)=1.33, respectively. The radiolytic mechanism is discussed in detail.
Abstract
The publication describes chelation studies of cerium(III) with 1,2-bis(
-aminoethoxy)-ethane N,N,N
,N-sodium sulfonate triacetic acid (ASTA). The results showed the effectiveness of ASTA as a chelating agent by molar ratio, continuous variation and slope ratio methods. Stable 1
1 complex was formed at pH from 4 to 8. Aqueous solutions of the chelate of different mole ratios at pH and 7.5 were irradiated by 
-radiation with different doses. The results show that a decrease of absorbance with increasing absorbed dose was obtained in the dose range studied. A proposed radiolytic mechanism is discussed. The degradation of ligand was due to OH radical.
Abstract
Synergic extraction of trivalent iron and cobalt with thenoyltriflouroacetone (HTTA) and the synergic bases (B) benzylamine (BA), dibenzylamine (DBA) and tribenzylamine (TBA) was studied. The extracted adducts proved to have the general formula M(TTA)3·B for all the amines investigated. The formation constants of the mixed-ligand complexes decrease in the order DBA>TBA>BA. While equilibrium constant β3,1 for the Co(TTA)3·DBA complex is higher than the corresponding iron adduct, β3,1 for the iron adducts with BA and TBA are higher than those for cobalt.
Abstract
Empirical formulae, based upon thermo-analytical investigations, have been assigned for different cerium(IV) antimonate samples prepared under varying conditions of precipitation. Equilibria and apparent Na+-capacity measurements at different pH values were carried out to throw more light on their sorption behavior. From the general curve shape analysis of the capacity-pH curves, the possible ion exchange site acidity and site group concentration were characterized. The samples showed almost bifunctional cation exchange behavior. The results obtained are discussed in detail referring to some conclusions.
Abstract
2-Pentanoylfuran was synthesized by three different methods and the yield of each method was determined. The ketone was purified and 2-propanol was also purified from acetone. Their purities were measured by gas chromatography. Mixtures of 2-pentanoylfuran in 2-propanol with concentrations 1, 10–1, 10–2 M had been irradiated by60Co 
-rays at different doses. The percent amount and radiation yield of ketone lost were determined at different absorbed doses. The discussion was used to interpret the results obtained.
Abstract
The aminolysis of hexachlorocyclodiphosphazane with substituted or unsubstituted arylamines, led to the preparation of some new organophosphorus compounds. It was also possible to isolate some new geometrical isomers containing substituted arylamines. It has been found that the aminolysis reactions of 1,3-diaryl-2,2,2,4,4,4-hexachlorocyclodiphosphazane take place without ring cleavage of the cyclodiphosphazane ring system, leading to 1,3-diaryl-2-oxo-2,2,4-arylcyclodiphosphazanes. The structures of these aminophosphorus compounds were substantiated on the basis of microanalytical data, infrared, ultraviolet and proton NMR spectroscopic evidence. Hexachlorocyclodiphosphazane and some aminosubstituted cyclodiphosphazane compounds were irradiated by gamma-rays and the ultraviolet measurements before and after irradiation were discussed. It was observed that all the absorption bands show the highest absorptivity values at a particular irradiation integral dose for each of the irradiated compounds. From the ultraviolet results and mass spectrometric data, it may be suggested that the possible decomposition sites of the amino-substituted cyclodiphosphazanes are at the double bond between the four-membered ring and the exocyclic phenyl ring and at the double bond between the four-membered ring and the oxygen atom.
Abstract
Gamma radiolysis of 2-acetylfuran (AF) in 2-propanol, in absence of atmospheric oxygen, has been investigated. The radiation yields of hydrogen, methane at different doses as well as radiolytic products in solution were determined. The radiolytic products were determined by gas chromatography coupled with mass spectrometry. The mechanisms for formation of detected radiolytic products and the effect of (AF) concentration on hydrogen and methane yields are discussed.
The thermal conductivity, specific heat capacity and thermal diffusivity of solid and molten ammonium thiocyanate, ammonium formate, ammonium acetate and ammonium nitrate were measured in the temperature range 80–190‡C, including the solid and liquid phases, by using the AC-heated strip (wire) technique. The results indicate that the thermal conductivities depend on the type of the ammonium salt. It was found that the mechanism of heat transfer is due to phonons in the region below the melting points of the salts, while above this region the main mechanism is due to conduction.
