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Microstructural Evolution during Partial Remelting of Al—Si Alloys Containing Different Amounts of Magnesium

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Journal of Materials Science & Technology 2013年第10期29卷 971-978页

作者： A.abedi M.Shahmiri B.Amir Esgandari B.Nami Department of Mechanical Engineering Shahid Rajaee Teacher Training University (SRTTU) School of Metallurgy and Materials Science Iran University of Science and Technology (IUST)

The effect of magnesium on the microstructures of A356 aluminum alloy in as-cast and semi-solid conditions was investigated. The result showed that magnesium refined the size of primary α（Al） phase and eutectic silicon. Magnesium also modified considerably the eutectic silicon and decreased the size of globular α（Al） solid phase in the semi-solid processed alloy. Coarsening rate of the solid α（Al） phase during partial remelting at semi-solid temperature decreased by adding magnesium, probably due to the decrease of both the solid- liquid interfacial energy and inter-diffusion coefficient of solute atoms.

关键词： Al--Si alloys Magnesium Microstructure Semi-solid processing Coarsening

Sound waves in fluidized bed using CFD-DEM simulations

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Particuology 2018年第3期16卷 126-133页

作者： hassan Abbas Khawaja Process and Gas Group Department of Engineering & Safety UiT-The Arctic University of Norway 9037 Langnes Tromso Norway

The speed of sound waves in a fluidized bed is investigated using CFD-DEM numerical simulations, Appro- priate initial and boundary conditions are applied to reproduce bed phenomena. The effect of varying the height of the bed is also studied. The results of the simulations matched those from the literature. The pressure and particle velocity profiles obtained feature oscillatory behavior to which functions （based on a damped standing wave） were fitted, enabling an explicit dependence on time and space variables to be established. These fitted functions were substituted into the linearized governing equations for the two-phase flow. These solutions enabled a new relationship to be derived for the speed of sound and damping in the system. The conclusion drawn is tbat the damping in the system is governed by the effective bulk viscosity of the solid phase, which arises from the particle viscosity.

关键词： Fluidized bed Sound waves Speed of sound Damping time CFD-DEM simulations

Selecting proper sites for underground dam construction using Multi-Attribute Utility Theory in arid and semi-arid regions

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Journal of Mountain Science 2023年第1期20卷 197-208页

作者： Mohammad hassan SADEGHIRAVESH hassan KHOSRAVI Azam ABOLHASANI Department of Environment College of AgricultureTakestan BranchIslamic Azad UniversityTakestanIran Department of Reclamation of Arid and Mountainous Regions Faculty of Natural ResourcesUniversity of TehranTehranIran

Although the construction of underground dams is one of the best methods to conserve water resources in arid and semi-arid regions,applying efficient methods for the selection of suitable sites for subsurface dam construction remains a *** to the costly and time-consuming methods of site selection for underground dam construction,this study aimed to present a new method using geographic information systems techniques and decision-making *** exclusionary criteria including fault,slope,hypsometry,land use,soil,stream,geology,and chemical properties of groundwater were selected for site selection of dam construction and inappropriate regions were omitted by integration and scoring layers in ArcGIS based on the Boolean ***,appropriate sites were prioritized using the Multi-Attribute Utility *** to the results of the utility coefficient,seven sites were selected as the region for underground dam construction based on all criteria and experts’*** site of Nazarabad dam was the best location for underground dam construction with a utility coefficient of 0.7137 followed by sites of Akhavan with a utility coefficient of 0.4633 and Mirshamsi with a utility coefficient of *** study proposed a new approach for the construction of the subsurface dam at the proper site and help managers and decision-makers achieve sustainable water resources with limited facilities and capital and avoid wasting national capital.

关键词： Prioritization Geographic information system Multi-Attribute decision making Arid region

The Hochschild Cohomology of the Chinese Monoid Algebra

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Algebra Colloquium 2022年第4期29卷 619-632页

作者： hassan Alhussein Siberian State University of Telecommunications and Informatics NovosibirskRussia Novosibirsk State University of Economics and ManagementNovosibirskRussia

In this work we find the groups of Hochschild cohomologies for the Chinese monoid algebra and derive its Hilbert and Poincaré*** order to obtain this result we construct the Anick resolution via the algebraic discret... 详细信息

关键词： Hochschild cohomology Anick resolution Grobner-Shirshov basis Morse matching

The bulk viscous string cosmology in an anisotropic universe with late time acceleration

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Research in Astronomy and Astrophysics 2013年第4期13卷 387-398页

作者： hassan Amirhashchi Department of Physics Mahshahr BranchIslamic Azad University

A model of a cloud formed by massive strings is used as a source of Bianchi type II cases. We assume that the expansion （θ） in the model is proportional to the shear （σ）. To get an exact solution, we consider the equation of state of the fluid to be in the stiff form. It is found that the bulk viscosity played a very important role in the history of the universe. In the presence of bulk viscosity the particles dominate over strings whereas in the absence of it, strings dominate over the particles, which is not consistent with recent observations. Also we observe that the viscosity causes the expansion of the universe to be accelerating. Our models are evolving from an early decelerating phase to a late time accelerating phase. The physical and geometrical behaviors of these models are discussed.

关键词： cosmology: theory -- viscous fluid -- massive string

Interacting viscous dark energy in a Bianchi type-Ⅲ universe

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Research in Astronomy and Astrophysics 2014年第9期14卷 1121-1134页

作者： hassan Amirhashchi Young Researchers and Elite Club Mahshahr Branch Islamic Azad University Mahshahr Iran

We study the evolution of the equation of state of viscous dark energy in the scope of Bianchi type III space-time. We consider a case where the dark energy is minimally coupled to the perfect fluid, as well as in direct interaction with it. The viscosity and the interaction between the two fluids are parameterized by constants 40 and σ, respectively. We have made a detailed investigation of the cosmological implications of this parametrization. To differentiate between different dark energy models, we have performed a geometrical diagnostic by using the statefinder pair {s, r}.

关键词： Bianchi type-III models -- dark energy -- statefinder

Inhibitory effect of gold nanoparticles conjugated with interferon gamma and methionine on breast cancer cell line

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Asian Pacific Journal of Tropical Biomedicine 2016年第2期6卷 173-178页

作者： Nastaran Mohseni Fatemeh Salehi sarvestani Mehdi Shafiee Ardestani Fatemeh Kazemi-Lomedasht Masoud Ghorbani Biotechnology Research Center Biotechnology Department Venom and Biotherapeutics Molecules Laboratory Pasteur Institute of Iran Department of Biology Science and Research Branch Islamic Azad University Department of Radiopharmacy Faculty of Pharmacy Tehran University of Medical Sciences Research and Development Department Pasteur Institute of Iran Department of Virology University of Ottawa

Objective: To develop a gold nanoparticles complex conjugated with interferon-gamma(IFN-g) and methionine along with application of hyperthermia using near-infrared laser beams for the treatment of cancer ***: Gold nanorods(10 nm) were conjugated with IFN-g and methionine using carbodiimide family and characterized after purification by dialysis bags. Breast cancer cells were cultured and incubated with gold nanorods at different concentrations followed by irradiation with near-infrared laser beam. Samples were then evaluated for their viability in order to determine the effect of treatment and variables by MTT ***: Zetasizer results confirmed the conjugation of gold nanorods with methionine and IFN-g. The median percentage of cell viability in 0.30 mg/m L concentration of gold nanorods was 82%. The cell viability reached to 85% at the same concentration of gold nanorods, which existed in the assayed complex. The results of MTT assay showed that the 0.60 mg/m L concentration of gold nanoparticles complex was toxic on tumor cells(P < 0.05). After exposure to hyperthermia, the viability of cells at 6 min decreased to77% in 0.30 mg/m L concentration of gold nanorods ***: The size and concentration of gold nanorods was not cytotoxic. However,their presence during irradiation near-infrared laser increased the number of dead cells during the treatment of cells.

关键词： Gold nanorods Breast cancer cell line Interferon gamma Near-infrared laser

Cohomogeneity One de Sitter Space S1 n

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Acta Mathematica Sinica,English Series 2010年第10期26卷 1915-1926页

作者： P.AHMADI S.M.B.KASHANI H.abedi Department of Pure Mathematics Faculty of Mathematical SciencesTarbiat Modares University Group of Mathematics School of Sciences Bu-Ali Sina University

In this paper we study the cohomogeneity one de Sitter space S1 n. We consider the actions in both proper and non-proper cases. In the first case we characterize the acting groups and orbits and we prove that the orbit space is homeomorphic to R. In the latter case we determine the groups and consequently the orbits in some different cases and prove that the orbit space is not Hausdorff.

关键词： Cohomogeneity one Lorentzian space de Sitter space

Pollen morphology of the family Cistaceae in Egypt and its systematic significance

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Journal of Systematics and Evolution 2011年第4期49卷 362-371页

作者： Nasr M.hassan Botany Department Faculty of ScienceAssiut University

The pollen morphology of 11 species (including two subspecies and two varieties) belonging to two genera (Helianthemum and Fumana) of the family Cistaceae in Egypt was studied using light and scanning electron *** grains of the studied taxa were found to be radially symmetrical and *** size,shape,apertures,and exine ornamentation characteristics were valuable parameters among the studied *** largest pollen size was recorded in *** and the smallest one observed in *** ***- *** shape in the Egyptian taxa varied from (sub-)prolate to prolate spheroidal,but *** is different in having sub-oblate *** pollen data confirm that *** and *** are very closely related *** sculpture was useful in distinguishing between *** *** and *** *** main pollen types of exine ornamentation were recognized: retipilate;reticulate to verrucate;and *** on palynological data,a key for the studied taxa is suggested.

关键词： Cistaceae exine sculpture palynology scanning electron microscopy.