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Formation region of emitted α and heavier particles inside radioactive nuclei

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Chinese Physics C 2020年第7期44卷 118-125页

作者： w.m.seif A.m.H.Abdelhady Cairo University Faculty of ScienceDepartment of Physics12613 GizaEgypt Beni-Suef University Faculty of Navigation Science and Space Technology62514 Beni-SuefEgypt

we investigate the formation distance(R0)from the center of the radioactive parent nucleus at which the emitted cluster is most probably *** calculations are performed microscopically starting with the solution to the time-independent Schr?dinger wave equation for the cluster-core system,using nuclear potentials based on the Skyrme-SLy4 nucleon-nucleon interactions and folding Coulomb potential,to determine the incident and transmitted wave functions of the *** results show that the emitted cluster is mostly formed in the pre-surface region of the nucleus,under the effect of Pauli blocking from the saturated core *** deeperα-formation distance inside the nucleus allows less preformation probability and indicates a more stable nucleus for a longer ***,theα-particle tends to be formed at a slightly deeper region inside the nuclei,with larger isospin asymmetry,and in the closed shell *** the heavy clusters,we observed that the formation distance of the emitted clusters heavier thanα-particle increased via increasing the isospin asymmetry of the formed cluster rather than by increasing its mass *** partial half-life of a certain cluster-decay mode increased with increase of either the mass number or the isospin asymmetry of the emitted cluster.

关键词： alpha-decay cluster decay Skyrme-SLy4 nucleon-nucleon interaction formation region

Constraints on the nuclear symmetry energy and its density slope from theαdecay process

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Chinese Physics C 2018年第6期42卷 79-87页

作者： w.m.seif A.S.Hashem Cairo University Faculty of ScienceDepartment of Physics12613 GizaEgypt

we study the impact of the nuclear symmetry energy and its density dependence on the α-decay *** the framework of the preformed cluster model and the energy density formalism, we use different parameterizations of the Skyrme energy density functionals that yield different equations of state（EOS）. Each EOS is characterized by a particular symmetryenergy coefficient（asym） and a corresponding density-slope parameter L. The stepwise trends of the neutron（proton） skin thickness of the involved nuclei with both asym and L do not clarify the oscillating behaviors of the α-decay half-life Tα with these quantities. we find that the change of the skin thickness after α-decay satisfactorily explains these behaviors. The presented results provide constraints on asym centered around an optimum value asym = 32 meV, and on L between 41 and 57 meV. These values of asym and L, which indicate larger reduction of the proton-skin thickness and less increase in the neutron-skin thickness after an α-decay,yield a minimum calculated half-life with the same extracted value of the α-preformation factor inside the parent nucleus.

关键词： alpha decay symmetry energy neutron-skin thickness proton-skin

Comprehensive study on the results of tension leg platform responses in random sea

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1305-1317页

作者： TABESHPOUR m.R GOLAFSHANI A.A. seif m.S Department of Civil Engineering Sharif University of Technology P.O.Box 11365-9313 Tehran Iran Department of mechanical Engineering Sharif University of Technology P.O.Box 11365-9313 Tehran Iran

Compliant offshore structures are used for oil exploitation in deep water. Tension leg platform (TLP) is a suitable type for very deep water. The nonlinear dynamic response of TLP under random sea wave load is necessary for determining the maximum deformations and stresses. Accurate and reliable responses are needed for optimum design and control of the structure. In this paper nonlinear dynamic analysis of TLP is carried out in both time and frequency domains. The time history of random wave is generated based on Pierson-moskowitz spectrum and acts on the structure in arbitrary direction. The hydrodynamic forces are calculated using the modified morison equation according to Airy’s linear wave theory. The power spectral densities (PSDs) of displacements, velocities and accelerations are calculated from nonlinear responses. The focus of the paper is on the comprehen-sive interpretation of the responses of the structure related to wave excitation and structural characteristics. As an example a case study is investigated and numerical results are discussed.

关键词： Tension leg platform (TLP) Ocean wave Stochastic Nonlinear

Experimental Study on Hysucat Vessels

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海洋工程：英文版 2004年第3期18卷 477-484页

作者： m. S. seif m. Askari Sharif University of Technology P. O. Box 11365-9567 Azadi Ave Tehran IranSharif University of Technology P. O. Box 11365-9567 Azadi Ave Tehran Iran

The paper contains the results of an experimental study on a planing catamaran. The aim of this study is resistance reduction with application of foils. Experiments are performed in different conditions and the results are compared with each other. The foils are used in different configurations and it is concluded that unsuitable design may result in larger resistance. But, it is also shown that, for a good design, the resistance may be reduced considerably.

关键词： catamaran hydrodynamic resistance

Influences of TiC Impurities on Dry-sliding wear of Polycrystalline Ceramic

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Journal of wuhan University of Technology(materials Science) 2022年第4期37卷 570-575页

作者： BENDAOUDI seif Eddine BOUNAZEF mokhtar DJEFFAL Ali Laboratory of Industrial Engineering and Sustainable Development Department of Mechanical EngineeringUniversity of RelizaneAlgeria Department of mechanical Engineering University Djillali LIABES of Sidi Bel AbbesAlgeria

The wear behavior of titanium silicon carbide mAX phase was *** of highly pure TiSiCand containing 8% of TiC,sliding dryly against Corundum counterpart,were tested at various speeds increasing from 5 to 60 m/s and under applied pressure of 0.1-0.8 *** sliding-wear tests were performed on Tribometer,at room temperature of 15℃ with a relative humidity of 10%.The expermental results show that the presence of TiC particles can be beneficial to reducing the wear rate for certain ranges of sliding speed and applied *** sliding-wear performances were expressed as a mathematical model,obtained through a modelling by the method of design of *** influence of TiC impurities on the wear behaviors was also *** is concluded that the wear mechanisms of samples are more affected by the presence of TiC under the effect of applied pressure compared with that of the sliding speed.

关键词： sliding-wear pin-on-disc design of experiments mathematical model polycrystalline ceramic

A Numerical Study on the Asymmetric water Entry of A wedge Section

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海洋工程：英文版 2004年第4期18卷 595-604页

作者： m. S. seif S. m. mousaviraad S. H. Saddathosseini Department of mechanical Engineering Sharif University of Technology Tehran Iran Department of Mechanical Engineering Sharif University of Technology Tehran Iran Department of Mechanical Engineering Sharif University of Technology Tehran Iran

The effect of the asymmetric water entry over a submerged part of a ship on the hydrodynamic impact is investigated numerically. A wedge body is considered and the problem is assumed to be two-dimensional. The results of symmetric and asymmetric impacts are compared. The effect is found significant in the numerical simulation. The maximum hydrodynamic pressure at a heel angle of 10 degrees becomes about 95% more than that of the symmetric entry. The result of the present work proves the importance of asymmetrical hydrodynamic impact loading for structural design of a ship. Besides, the numerical procedure is not limited to a wedge type cross section and it is possible to apply it for any real geometry of ships and high-speed craft.

关键词： asymmetric water entry hydrodynamic impact

Hydroxysafflor yellow A protects against thioacetamide-induced liver fibrosis in rats via suppressing proinflammatory/fibrogenic mediators and promoting hepatic stellate cell senescence and apoptosis

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Asian Pacific Journal of Tropical Biomedicine 2023年第8期13卷 348-358页

作者： Sayed H.seif el-Din Olfat A.Hammam Shahira m.Ezzat Samira Saleh marwa m.Safar walaa H.El-maadawy Naglaa m.El-Lakkany Pharmacology Department Theodor Bilharz Research InstituteWarak El-HadarImbaba P.O.Box 30Giza 12411Egypt Pathology Department Theodor Bilharz Research InstituteWarak El-HadarImbaba P.O.Box 30Giza 12411Egypt Pharmacognosy Department Faculty of PharmacyCairo UniversityCairo 11562Egypt Pharmacognosy Department Faculty of PharmacyOctober University for Modern Sciences and ArtsGizaEgypt Pharmacology and Toxicology Department Faculty of PharmacyCairo UniversityCairo 11562Egypt Pharmacology and Biochemistry Department Faculty of PharmacyThe British University in EgyptCairoEgypt

Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver ***:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 ***-intoxicated rats were given silymarin(50 mg/kg)or HSYA(5 mg/kg)orally every day for 8 *** enzymes,fibrosis markers,histological changes as well as immunohistochemistry of TNF-α,IL-6,p21,α-SmA,and caspase-3 were *** effect of HSYA on HSC-T6 activation/proliferation and apoptosis was also determined in ***:HSYA decreased liver enzymes,TNF-α,IL-6,and p21 expressions,hepatic PDGF-B,TImP-1,TGF-β1,and hydroxyproline levels,as well as fibrosis score(S2 vs.S4)compared to the thioacetamide *** also downregulatedα-SmA while increasing caspase-3 ***,at 500μg/mL,HSYA had only a slightly suppressive effect on HSC proliferation,with a 9.5%***,it significantly reduced TGF-β1,inhibitedα-SmA expression,induced caspase-3 expression,and promoted cell ***:HSYA may be a potential therapeutic agent for delaying and reversing the progression of liver *** research on HSYA at higher doses and for a longer period is warranted.

关键词： Hydroxysafflor yellow A Thioacetamide Hepatic stellate cells Inflammatory markers Liver fibrosis p21 α-SmA Apoptosis

Impact of Bee Pollination on Yield of Faba Bean (<i>Vicia faba</i>L.) Grown under Semi-Arid Conditions

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Agricultural Sciences 2018年第6期9卷 729-740页

作者： seif m. Gasim Awadalla A. Abdelmula Department of Agronomy Faculty of Agriculture University of Khartoum Shambat Sudan

The effect of honeybee (Apis mellifera carnica) on yield was investigated in open-pollinated faba bean cultivars and three inbred generations produced from them (once-selfed, twice-selfed, and thrice-selfed). All entries were grown in cages under two pollination conditions: presence of bees (cross-pollination) or absence of bees (self-pollination). The open-pollinated generations gave the highest performance in the presence and absence of bees. In the presence of bees, the open-pollinated and their inbred entries gave higher performance in all of the studied traits than in the absence of bees;the average improvement in yield and its components was 22%. The highest improvement percentage in yield performance was shown by more inbred entries (thrice-selfed > once-selfed), indicating that in faba bean populations, the performance of inbred generations was chiefly associated with the tripping of flowers, which is usually governed by successfully fertilized flowers, i.e., plants result from selfing in faba bean population needs to be visited by pollinating insects (bees) to set more seeds. It concluded that honeybee has an important role in increasing faba bean yield in semi-arid conditions;hence, it is important to provide a pollinator friendly environment for their foraging places and nesting sites to secure food supply.

关键词： Faba Bean Yield Honey Bees Pollination Self-Fertilization Cross-Fertilization Inbred-Generation

Genetic Diversity in the Semi-Arid Grown Cowpea(<i>Vigna unguiculata</i>L. walp)Accessions Using morphological and molecular Characterization

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Agricultural Sciences 2020年第8期11卷 692-706页

作者： Ahmed A. Elteib seif m. Gasim Department of Agronomy Faculty of Agriculture University of Khartoum Shambat Sudan

Assessment of genetic diversity of the indigenous crop accessions is extremely important for breeders to identify potential parents in cross-breeding programs. Fourteen cowpea accessions collected from different parts of Sudan were used for characterization at morphological and molecular levels. The seeds of the accessions were sown in the field using a randomized complete block design with three replicates. Sixteen morphological descriptors (9 qualitative and 7 quantitative) and 20 Random Amplified Polymorphic DNA (RAPD) markers were used for characterization of the accessions. The results of morphological data revealed considerable variability within and between state’s accessions. Some morphological traits revealed similarity between accessions from different states. Among the 20 RAPD markers used, 18 were polymorphic. A total of 379 polymorphic patterns were generated;polymorphic information content (PIC) ranged from 0.63 to 0.98 with an average of 0.9. The number of fragment detected ranged from 2 for OPL-11 to 51 for OPY-2 with an average of 26.06/primer and 27.07/genotype. One to five (1 - mily:Verdana;">mily:Verdana;">mily:Verdana;">5) unique fragments of different sizes were detected for particular accessions, which may provide a valuable resource for breeding superior cowpea cultivars in Sudan and other semi-arid zones. Genetic similarity was ranged from 0.02 to 0.47 with an average of 0.25. Highe

关键词： Cowpea Accessions Genetic Diversity Characterization morphological markers RADP markers Polymorphism