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Abstract  

Synergic extraction of hydrolyzable lanthanides Dy(III) and Sm(III) has been studied in the low pH range with 0.3M (HTTA-TBA) in chloroform from aqueous perchlorate media. The synergic coefficient was calculated at different pH's and was found maximum at pH 3 for both elements. The composition of the adduct was established as M(TTA)3.3TBA at pH 3. However, a mixture of the adduct of the type M(TTA)3.TBA was proposed at pH 5.9. The possible reaction mechanism at both pHs is discussed, the stability constant m,n formation constants Km,o and Km,n have been calculated.

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grains of wheat (Triticum aestivumL. cv. Raj-3077) were soaked in 0, 10-5, 10-4or 10-3 M aqueous solutions of salicylic acid (SA) for 3, 6 or 9 h. The seedlings raised from grains pre-treated with 10-5 M SA possessed significantly higher leaf number, fresh and dry mass per plant, and nitrate reductase and carbonic anhydrase activities 30 and 40 days after sowing. However, 10-3 M SA reduced all the above-mentioned parameters.

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The main aim of this study was to evaluate the appropriateness of using different diversity indices for conservation purposes in arid environments. The study was done on Mt Serbal as a case study representing mountainous arid areas. Mt Serbal is one of the richest and most diverse areas in Egypt. It was sampled by 97 stands representing different vegetation cover, land-forms and habitats. Species density and environmental factors (including altitude, slope, soil texture, hygroscopic moisture, water holding capacity, pH, EC, and soil organic matter content) were recorded or measured in each stand. The results reveal that Mt Serbal is characterised by a high diversity of plant species and the most diverse area is Shaq Sha’rany. The study recommends Margalef and species richness as the most suitable to measure the diversity at different localities, land-forms, and vegetation groups. It emphasises on the necessity of reporting on species richness in any conservational study. Meanwhile, indices that are excessively sensitive to change in sample size, gear, or handling procedures should be avoided.

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Abstract  

Different Nd-zeolites were prepared from the original NaX and NaY zeolites by ion exchange. The hydrated and thermally activated (at 550 °C) samples obtained were irradiated with -rays of 1.5 and 10.0 Mrad. The unirradiated and irradiated samples were characterized mainly by X-ray diffraction and tested for catalytic activity in cumene cracking. The X-ray diffraction patterns indicated a slight decrease of crystallinity after irradiation. However, the irradiated samples exhibited higher catalytic activities than unirradiated ones. -Irradiated hydrated zeolites were found to possess comparable activities, whereas the irradiated dehydrated samples were more active. Higher irradiation doses resulted in more active dehydrated zeolites than those irradiated with a lower dose. The observed higher activity was attributed to the formation of tricoordinate aluminium atoms in the zeolite structure, leading to increase of the number of acidic sites and consequently to a catalytic activity.

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Abstract  

Chicken and fish have been investigated for the detection of radiation treatment using thermoluminescence (TL) technique. The samples were irradiated by 60Co gamma-source at the absorbed doses of 1, 2, 3, 4 and 5 kGy. TL response of treated and untreated samples in the temperature range of 50–300 °C was measured using TL reader with a temperature profile of 10 °C/s. The results revealed that TL values increased with temperature and maximum signal were obtained at 195 °C, in each case. It was also observed that the TL intensities enhanced with the absorbed doses (1–5 kGy) and the increase was dependent on the absorbed dose. From this study it is concluded that the TL technique is a rapid, simple and promising method for identifying chicken and fish treated with gamma-irradiation.

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Studies on pollution of water and air dust of Benghazi using various analytical methods

I. The analysis of air dust samples from Benghazi for trace elements using neutron activation analysis and flameless atomic absorption

Journal of Radioanalytical and Nuclear Chemistry
Authors: A. El Hossadi, A. Alian, S. Ali, R. Farooq, A. Hamid, and Tahra Majed

Abstract  

Nondestructive neutron activation analysis has been used for the analysis of 17 out of 24 elements in 12 samples of air particulate matter collected from various localities in Benghazi. Both relative and monostandard methods were used. The neutron activation method was supplemented with graphite furnace atomic absorption, so that most toxic elements could be assayed in the same samples. Thus Cd, Cr, Cu, Mn, Ni, Pb, V and Zn could be analysed quantitatively in most of the samples. It has been found that contamination of the atmosphere of Benghazi with dust is largely due to heavy construction work in the city, action of wind on the surface of land around the city and the release of exhaust products from vehicles and airplanes. Particular contamination due to industrial activities was not noticeable. Results on samples from Benghazi were compared with those from Prague, Munich and Sendai.

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Abstract  

The proton particle induced X-ray emission (proton PIXE) technique has been employed to study the heavy element status (essential and toxic) in five different varieties of pulses commonly cultivated and consumed in Bangladesh. In this analysis, the samples were irradiated in air with 2 MeV protons having 30 nA beam intensity for characteristic X-ray excitation. For 40 C irradiations, the concentration of ten elements (K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, and Rb) was determined by comparison with a calibration obtained from the NBS orchard leaf standard, SRM 1571. In a comparative study with atomic absorption spectrophotometric (AAS) measurements of some elements in lathyrus sativus, the data were found to be in good agreement. The results obtained from the present study are discussed and compared with available data.

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Abstract

A series of CoMo/γ-Al2O3 catalysts was prepared with [Co/(Co + Mo)] ratios of 0.3, 0.4 and 0.5 while maintaining a total metal content of 19 wt%. These catalysts were tested in a batch autoclave reactor after presulfiding with the objective of studying the influence of Co/(Co + Mo) ratio on the hydrodesulfurization (HDS) pathways of benzothiophene (BT) and dibenzothiophene (DBT). The results of this study have clearly demonstrated that the Co/Co + Mo ratio has a significant influence on the overall HDS of BT and DBT as well on the direct desulfurization (DDS) pathway, but showed no influence on the hydrogenation pathway. A Co/Co + Mo ratio of 0.4 was found to be optimum for both overall HDS as well as the HDS by DDS pathway.

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Abstract

Ibuprofen (C15H18O2) is an anti-inflammatory drug. It is important to investigate its structure to know the active groups and weak bond responsible for its medical activity. Consequently in the present study, ibuprofen was investigated by mass spectrometry (MS) and thermal analyses (TAs) (TG/DTG and DTA), and confirmed by semi-empirical molecular orbital (MO) calculation using PM3 procedure, on the neutral and positively charged forms of the drug. These calculations included bond order, bond length, and bond strain, and charge distribution, heat of formation, and ionization energy. The mass spectra and thermal analysis fragmentation pathways were proposed and compared to each other to select the most suitable scheme representing the correct fragmentation pathway of the drug in both techniques. From the electron ionization (EI) mass spectra, the primary cleavage site of the charged molecule is because of the rupture of COOH group (the lowest bond order) followed by propyl group loss. The TAs of the drug revealed high response of the drug to the temperature variation with very fast rate. It decomposed in several sequential steps in the temperature range 25–360 °C. The initial thermal decomposition is similar to that obtained by MS fragmentation of the first rupture (COOH), then subsequent one of propyl loss, and finally of ethylene loss. These mass losses appear as endothermic peaks required energy values of −214.83, −895.95, and −211.10 J g−1, respectively. The order of these losses is also related to the values of the MO calculation parameters. Therefore, the comparison between MS and TA helps in the selection of the proper pathway representing the decomposition of this drug to give its metabolites in in vivo system. This comparison is also successfully confirmed by MO calculations.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: A. Qureshi, A. Sultan, A. Rashid, M. Ali, A. Waheed, S. Manzoor, M. Baloch, Matiullah, S. Batool, and H. Khan

Abstract  

Mount Arafat is a sacred place for Muslims. It has been classified as a granodiorite rock which mainly consists of feldspar and quartz, muscovite, etc. During the Hajj and Umra, Muslims visit this holly place and stay there for some time. In order to study the geology and thermal history as well as to assess the radiological hazards due to the presence of primordial radionuclides, systematic studies using petrographic, fission track dating and γ-spectrometric (HPGe) techniques were carried out. Our study yielded fission track age of 9.13 ± 1.05 Ma of the Mount Arafat granodiorite. Rifting, magmatism, volcanism and sea floor spreading that resulted in the formation of Red Sea seems may have altered the original age of the Arafat granodiorite under study to 9.13 ± 1.05 Ma. Measured radioactivity concentrations due to 226Ra, 232Th and 40K were found to be 10.75 ± 3.92, 29.21 ± 4.34 and 664.49 ± 7.45 Bq kg−1, respectively. From the measured radioactivity, gamma index (Iγ) and radium equivalent (Raeq) were calculated as 0.402 and 103.23 Bq kg−1 whereas outdoor external dose (Dout) and annual effective dose (Eout) were estimated to be 40.30 nGyh−1 and 0.045 mSvy−1 respectively. All the above mentioned values are well below the recommended limits. The Mount Arafat thus does not pose any radiological health hazard to the general public.

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