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Impact of wastewater reuse on cobalt status in Egyptian environment

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Journal of Environmental Sciences 2003年第3期15卷 388-395页

作者： m.f. Abdel-Sabour Soil and Water Research Department Nuclear Research Center Atomic Energy Authority

Cobalt is used in the manufacture of alloys, catalysts in the petroleum industry, catalytic converters, and paint pigments. Thus the potential for Co releases into the environment is highly increased. Use of waste sludges and sewage effluent to fertilize and irrigate soils has also increased soil Co concentrations. Total cobalt contents of alluvial delta soil of Egypt show considerable variation ranging from 13.1 to 64.7 ppm. The impact of either wastewater irrigation or industrial activities on soil total Co was obvious due to accumulation of organic matter and solid waste in the surface soil samples. food crops and vegetables should not be grown on soil highly contaminated by Co. It is noteworthy that the delayed neutron activation analysis(DNAA) technique could be used successfully for total Co determination due to its high sensitivity. It is quit clearly that dust samples of Cairo City contains higher Co level, as compared to Suez Canal Region(Ismailia, Port Said and El-Suez cities). The high values in Cairo City may be due to the existence of industries around the city and the intensive traffic. To minimize Co environmental hazards, waste effluents should be treated on site. Thus, levels of potentially toxic Co needs to be continuously monitored and should be removed during several treatment processes before the disposal of these wastes.

关键词： cobalt environment Egypt

CRACK GROWTH BEHAVIOR AND fRACTURE fEATURE Of GH2132 UNDER CREEP-fATIGUE CONDITIONS

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Acta metallurgica Sinica(English Letters) 1997年第6期10卷 495-500页

作者： Geng, m.f. Luoyang Ship material Research Inst Luoyang China

The superalloy GH2132 is equivalent to A286. The tests were carried out at 550°C under various cyclic frequencies (hold time) and load levels, and the fracture surfaces were examined by using a scanning electron microscope. It was shown that the fracture mode of creep-fatigue and the effect of cyclic loading on crack growth change with the growth of crack and the increase of net-section stress, and both are reversed when the net-section stress is up to the yield stress of material. When σn0.2, cracking is predominantly cyclic-dependent transgranular and cyclic loading accelerates creep crack growth, whereas when σn>σ0.2, the case is reversed.

关键词： Chromium alloys Crack propagation Creep fracture Nickel alloys Rotating disks Superalloys

Simulation of buoyancy-induced turbulent flow from a hot horizontal jet

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Journal of Hydrodynamics 2014年第1期26卷 104-113页

作者： El-AmIN m.f. SUN Shuyu SALAm Amgad Computational Transport Phenomena Laboratory (CTPL) Division of Physical Sciences and EngineeringKing Abdullah University of Science and Technology

Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Reynolds numbers are considered. Both experimental visualization and numerical computations are carried out for the same flow and thermal conditions. The realizable k-e model is used for modeling the turbulent flow while the buoyancy is modeled using the Boussinesq approximation. Polynomial approximations of the water properties are used to compare with the Boussinesq approximation. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank as well as the froude number are analyzed. The experimental visualizations are performed at intervals of five seconds for all different cases. The simulated results are compared with the visualized results, and both of them show the stratification phenomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on the case condition, the flow tends to reach a steady state.

关键词： turbulent flow realizablc k - e turbulence model heat transfer jet heat storage

Review on nanocomposites fabricated by mechanical alloying

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International Journal of minerals,metallurgy and materials 2019年第9期26卷 1047-1058页

作者： mohammed A. Taha Rasha A. Youness m.f. Zawrah Solid State Physics Department National Research CentreEl Buhouth St.Dokki 12622CairoEgypt Spectroscopy Department National Research CentreEl Buhouth St.Dokki 12622CairoEgypt Refractories Ceramics and Building Material DepartmentNational Research CentreEl Buhouth St.Dokki 12622CairoEgypt

Composites are composed of multiphase materials, where each phase has specific properties that differ from those of the other phases which can effect on the whole properties of composite. Nanocomposites are class of materials that contain at least one phase in the nanometric size range and can be produced by any suitable technique for preparing nanomaterials. Composites are an interesting class of materials that have recently been used in numerous applications, including structural, biomedical, electronics, and environmental applications. In composites, reinforcements might be fibers, particulates, or whiskers. mechanical alloying(mA) is a promising technique for producing nanocomposite materials that are difficult or impossible to prepare via conventional techniques. In this review, we provide an overview of nanocomposites prepared by the mA process. The mechanism of milling and other milling parameters are overviewed, and insights into sintering categories and parameters are also presented.

关键词： nanocomposites mechanical alloying fabrication sintering

OPTImIZATION Of THE SYNTHESIS Of ACRYLAmIDE HYDROGEL BY γ-RAY IRRADIATION

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Chinese Journal of Polymer Science 2004年第3期22卷 253-258页

作者： m.A. Chowdhury m.m. Alam m.f. mina f. Akhtar S.E. Kabir Department of Chemistry Faculty of Science Jahangir Nagar University Dhaka BangladeshNRCD INST AERE GPO Box-3787 Dhaka Bangladesh NRCD INST AERE GPO Box-3787 Dhaka Bangladesh NRCD INST AERE GPO Box-3787 Dhaka Bangladesh Department of Chemistry Faculty of Science Jahangir Nagar University Dhaka Bangladesh

Hydrogels have been synthesized from 10%, 20%, 30%, 40%, 50% and 60% aqueous solutions of acrylamide monomer by gamma radiation employing doses in the range of 0.2-30 kGy from a Co-60 source. The effect of solution concentration, γ-ray dose, pH and time was studied in order to observe the optimizing conditions in the characterization of hydrogels. Gel fraction increases with dose for all concentrations indicating hundred-percentage conversion of gel at doses 5 kGy for homogenous solutions in the range of 20%-50% concentration. On the other hand, 10% solution provides conversion less than 86% even at 30 kGy, whereas 60% monomer makes an inhomogeneous solution which stile gives about 100% gel fraction. Swelling of hydrogels under water with respect to time varies with both the doses and concentrations due to the change of crosslinking density in the gels. The maximum volume change of hydrogels during swelling and water desorption mainly occurs within 24 h. Swelling is also enhanced with the rise of pH due to change of ionic content of the solvent. Considering the amount of gel fraction and the properties of hydrogel, the samples prepared from 20% solution at 5 kGy show better results. moreover, the effect of bacteria on hydrogel was found to be nil, suggesting a prohibition of growth of microorganism in it.

关键词： Hydrogel Acrylamide γ-radiation Swelling microorganism

first-Principle Calculations of Hardness and melting Point of mo_2C

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Journal of materials Science & Technology 2009年第3期25卷 419-422页

作者： X.R. Wang m.f. Yan H.T. Chen School of materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

This paper has constructed two kinds of atomic and electronic models for hexagonal β-mo2C and orthorhombic α-mo2C. The optimized lattice parameters, elastic constant matrixes and overlap population for mo2C crystal cells have been obtained to realize the characterization of the hardness and melting point of the two structures by the first-principles plane wave pseudo potential method based on the density functional theory. The results reveal that the calculated lattice parameters of the mo2C crystal cells agree with the experimental and other calculated data. The calculated melting point/hardness are 2715 K/11.38 GPa for β-mo2C and 2699 K/10.57-12.67 GPa for α-mo2C, respectively. The calculated results from the density of states （DOS） demonstrate that the hybridization effect between mo-3d and C-2p states in α-mo2C crystal cell is much stronger than that in β-mo2C one.

关键词： first-principle mo2C Hardness melting point Density of states

Luminescence Studies on Interaction of an Isoquinoline Alkaloid with Calf Thymus DNA in Aqueous medium and on Solid Substrate

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Chemical Research in Chinese Universities 2012年第4期28卷 614-619页

作者： LI Jun-fenl SHI Wen-tao HAN Xiu-ying DONG Chuan CHOI martin m.f. School of Chemistry and Chemical Engineering Research Center of Environmental Science and Engineering Shanxi UniversityTaiyuan 030006P.R.China Department of Chemistry Hong Kong Baptist UniversityHong KongP.R.China

The interaction of calf thymus DNA（ctDNA） with berberine（Ber） was systematically investigated via UV-Vis,fluorescence and phosphorescence spectroscopies in aqueous solution and on solid *** very weak fluorescence intensity of Ber at 525 nm in aqueous solution can be greatly enhanced by *** UV-Vis spectrum shows that Ber could bind with DNA by *** addition,strong fluorescence of Ber alone could be observed on filter paper substrate and can be quenched by ctDNA effectively,and the increase of fluorescence polarization of Ber on the filter paper implies the intercalation *** emits phosphorescence at 619 nm in the presence of thallium（I） *** lifetime of Ber increased from 38.4 ms to 43.4 ms with the increase of *** increase of lifetime is possibly attributed to the increase of rigidity of Ber after its intercalating into the ctDNA base *** explanation is also augmented by the anionic quenching *** behaves as a typical intercalating agent into *** intrinsic binding constant between Ber and ctDNA is（1.84±0.12）×10^4 L/mol and n=0.16.

关键词： Berberine Calf thymus DNA UV-Vis spectroscopy Luminescence Interaction

missense mutations of the fibrillin-1 gene in two Chinese patients with severe marfan syndrome

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Chinese medical Journal 2001年第5期114卷 25-28页

作者： Ivan f.m. LO, Rosanna m.S. WONG, fanny W.f. LAm, Tony m.f. TONG and Stephen T.S. LAm Clinical Genetic Service Department of Health 3/F Cheung Sha Wan Jockey Club Clinic 2 Kwong Lee Road Shamshuipo Kowloon Hong Kong Special Administrative Region China. akyblue@***

Objective To describe two Chinese patients with severe forms of marfan syndrome and to report findings of mutational analysis of the fibrillin-1 (fBN1) *** Two Chinese patients were studied, one suffering from marfan syndrome of infantile onset and the other of neonatal onset. Their clinical features were described. mutational analysis of the fBN1 gene was performed using polymerase chain reaction (PCR) technique and direct sequencing of exons 23 - 32,where the mutational hotspots for severe forms of marfan syndrome are *** Two missense mutations were successfully identified, a G3037A transition and an A3083T transversion, the latter being an unreported *** Taking advantage of the clustering phenomenon of mutations in severe forms of marfan syndrome, one can identify fBN1 mutations in these patients by first screening the mutational hotspots,thus reducing the effort that would otherwise be much greater because of the size of the gene.

关键词： marfan syndrome fibrillin-1 mutation

Gut virome:New key players in the pathogenesis of inflammatory bowel disease

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World Journal of methodology 2025年第2期15卷 27-43页

作者： Helal f Hetta Rehab Ahmed Yasmin N Ramadan Hayam.f.thy mohammed Khorshid mohamed m mabrouk mai Hashem Department of medical microbiology and Immunology Faculty of MedicineAssiut UniversityAssiut 71515Egypt Division of microbiology Immunology and BiotechnologyFaculty of pharmacyUniversity of TabukTabuk 71491Saudi Arabia Division of microbiology Immunology and BiotechnologyDepartment of Natural Products and Alternative MedicineFaculty of PharmacyUniversity of TabukTabuk 71491Saudi Arabia Department of Internal medicine Division HepatogastroenterologyAssiut UniversityAssiut 71515Egypt Department of Clinical Research Egyptian Developers of Gastroenterology and Endoscopy FoundationCairo 11936Egypt Department of Internal medicine Faculty of Medicine.Tanta UniversityTanta 31527Egypt Department of Tropical medicine Gastroenterology and HepatologyAssiut University HospitalAssiut 71515Egypt

Inflammatory bowel disease(IBD)is a chronic inflammatory illness of the *** the mechanism underlying the pathogenesis of IBD is not fully under-stood,it is believed that a complex combination of host immunological response,environmental exposure,particularly the gut microbiota,and genetic suscept-ibility represents the major *** gut virome is a group of viruses found in great frequency in the gastrointestinal tract of *** gut virome varies greatly among individuals and is influenced by factors including lifestyle,diet,health and disease conditions,geography,and *** majority of research has focused on the significance of gut bacteria in the progression of IBD,although viral populations represent an important component of the *** conducted this review to highlight the viral communities in the gut and their expected roles in the etiopathogenesis of IBD regarding published research to date.

关键词： Inflammatory bowel disease Pathogenesis Gut virome Bacteriophage Eukaryotic viruses