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Investigation ofmodified zinc borate glasses doped with BaO as a nuclear radiation-shieldingmaterial

Radiation Detection Technology and Methods 2018年第2期2卷 101-107页

作者： h.A.Saudi S.u.El-Kameesy Department of Physics Faculty of Science(Girls’Branch)Al-Azhar UniversityCairoEgypt Department of Physics Faculty of ScienceAin Shams UniversityCairoEgypt

Background Radiation protection and detection have been a main interest for *** prepared glass samples were subjected to experimental investigations to evaluate their mechanical and attenuation *** a consequence,the values of the mass attenuation coefficient,total electronic cross section,the effective atomic number and an effective electron number were determined and utilized to assess the shielding effectiveness of the investigated glass *** mass attenuation coefficients of these samples were cal.ulated theoretically using WinXcom *** Preparation of glass of borate with zinc and barium can withstand shock,heat and corrosion to be used as a radiation *** Glass samples were prepared by melt quenching *** and molar volume measurements were obtained by applying the Archimedes *** hardness was measured by using a microhardness tester(leco AMh 100,uSA)for sample *** thermal behavior of the glass samples was investigated by differential scanning calorimetry(DSC).Also,by using a scintillator detector(1.5″×1.5″NaI(Tl))exposed to ^(232)Th,^(137)Cs and ^(60)Co gamma ray sources with accuracy range 0.12%.Results The investigated glasses have relatively good gamma ray attenuation properties,water resistance ability and thermal stability with increasing barium ***,they can be used in containers for keeping radioactive waste and radioactive *** The changes in the molar volume and density show approximately opposite linear ***,μm is dependent on the chemical compositions of glass samples and energy of gamma *** agreement between the experimentally obtained mass attenuation coefficient values and the corresponding theoretical predictions based on the known WinXcom program was ***,the effect of gamma irradiation on this glass is minor because its impact on the hardness values and dissolution rate is extremely small.

关键词： Borate glasses Shielding properties hardness Durabil

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In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels

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Regenerative Biomaterials 2019年第5期6卷 249-258页

作者： u.D’Amora A.Ronca M.G.Raucci S.M.Dozio h.lin Y.Fan X.Zhang l.Ambrosio Institute of Polymers Composites and BiomaterialsNational Research CouncilNaplesItaly Institute of Science and Technology for Ceramics National Research CouncilFaenzaItaly School of Advanced Study“G.D’Annunzio” University of Chieti-PescaraChieti Italy National Engineering Research Center for Biomaterials Sichuan UniversityChengduChina

The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid(hA)followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable hA polymers through sol-gel *** this way,it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer *** this aim,methacrylated and maleated hA,synthesized with similar degree of substitution(DS)were compared in terms of mechanical and physico-chemical *** success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric ***,mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with *** swelling behavior resulted to be correlated with filler ***,the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over cul.ure time was observed,highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties.

关键词： hyaluronic acid derivatives photocrosslinking sol-gel nanocomposites

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General investigation for longitudinal wave propagation under magnetic field effect via nonlocal elasticity

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Applied Mathematics and Mechanics(English Edition) 2015年第10期36卷 1305-1318页

作者： u.GVEN Department of Mechanical Engineering Yildiz Technical University

In this paper, the propagation of longitudinal stress waves under a longitu- dinal magnetic field is addressed using a unified nonlocal elasticity model with two scale coefficients. The analysis of wave motion is mainly based on the love rod model. The effect of shear is also taken into account in the framework of Bishop＇s correction. This analysis shows that the classical theory is not sufficient for this subject. however, this unified nonlocal elasticity model solely used in the present study reflects in a manner fairly realistic for the effect of the longitudinal magnetic field on the longitudinal wave propagation.

关键词： Rayleigh-Bishop rod nonlocal elasticity magnetic field wave propagation

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Phytochemically Functionalized Cu and Ag Nanoparticles Embedded in MWCNTs for Enhanced Antimicrobial and Anticancer Properties

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Nano-Micro letters 2016年第2期8卷 120-130页

作者： S.Yallappa J.Manjanna B.l.Dhananjaya u.Vishwanatha B.Ravishankar h.Gururaj P.Niranjana B.S.hungund Department of Industrial Chemistry Kuvempu University Department of Chemistry Rani Channamma University Toxicology and Drug Discovery Centre for Emerging Technologies Jain University SDM Centre for Research in Ayurveda and Allied Sciences Department of Electronics Kuvempu University Department of Biochemistry Kuvempu University Department of Biotechnology B.V.B.College of Engineering & Technology

Nanomedicine is an emerging field concerned with the use of precision engineered nanomaterials, which leads to the development of novel remedial and diagnostic modalities for human use. In this study, Cu(NO_3)_2 and Ag NO_3 precursors were reduced to copper nanoparticles(Cu NPs) and silver nanoparticles(Ag NPs) using Terminalia arjuna bark extracts under microwave irradiation in the presence of well-dispersed multi-walled carbon nanotubes(MWCNTs) in aqueous medium. The formation of Cu NPs or Ag NPs and their functionalization with MWCNTs via bioactive molecules of plant extract were evidenced from uV–Vis spectra, XRD, FTIR, FESEM, EDX, and TEM images. The phytochemically functionalized Cu-MWCNTs and Ag-MWCNTs nanomaterials showed enhanced biocide activity, and the inhibitory activity for bacteria was higher than that of fungus. Furthermore, these biohybrid nanomaterials are non-toxic to normal epithelial cells(Vero), whereas they are highly toxic for tested human cancer cells of MDA-MB-231, he la, Si ha, and hep-G2. The cell viability was found to decrease with the increasing dose from 10 to 50 lg m l^(-1), as well as incubation time from 24 to 72 h. For instance, the cell viability was found to be *91 % for normal Vero cells and *76 % for cancer cells for lower dose of 10 lg m l^(-1).

关键词： Cu-MWCNTs Ag-MWCNTs Terminalia arjuna bark extract Antimicrobial activity Anticancer activity

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Physico-chemical characterization of a farmland affected by wastewater in relation to heavy metals

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2008年第3期9卷 366-372页

作者： Emmanuel.u. ONWEREMADu Department of Soil Science and Technology Federal.university of Technology PMB 1526 Owerri Nigeria

This study investigated selected properties of soils affected by wastewater and its relationship with some heavy metals. A free survey technique involving target sampling was used in siting soil profile pits. Soil samples were collected based on horizon differentiation and analyzed using routine and special analytical techniques. Soil data were subjected to correlation analysis using SAS program. Results show that all heavy metals studied had values above critical limits in the pol.uted soils using known standards and that these biotoxic metals decreased with soil depths. highly significant (P=0.01 and 0.05) relationships were established between investigated heavy metals and some soil properties, especially soil ph and organic matter. Further studies involving more edaphic properties, biotoxic metals and their bioaccessibility in crops growing on wastewater soils will surely enhance knowledge and management of these highly anthropogenically influenced soils of the study site.

关键词： Bioavailability Characterization heavy metals Soil pol.ution Wastewater

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The spin-isospin decomposition of the nuclear symmetry energy from low to high density

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Chinese Physics C 2020年第5期44卷 114-118页

作者： Wenmei Guo M.Colonna V.Greco u.lombardo h.-JSchulze Department of Physics Anhui Normal UniversityWuhu 241000China laboratori Nazionali del Sud(INFN) Via S.Sofia 6295123 CataniaItaly Dipartimento di Fisica e Astronomia Via S.Sofia 6495123 CataniaItaly INFN Sezione di CataniaVia S.Sofia 6295123 CataniaItaly

The energy per particle BA in nuclear matter is cal.ulated up to high baryon density in the whole isospin asymmetry range from symmetric matter to pure neutron *** results,obtained in the framework of the Brueckner-hartree-Fock approximation with two-and three-body forces,confirm the well-known parabolic dependence on the asymmetry parameterβ=(N?Z)/A(β^2 law)that is valid in a wide density *** investigate the extent to which this behavior can be traced back to the properties of the underlying interaction,aside from the mean field approximation,the spin-isospin decomposition of BA is *** indications suggest that theβ^2 law could be violated at higher densities as a consequence of the three-body *** raises the problem that the symmetry energy,cal.ulated according to theβ^2 law as a difference between BA in pure neutron matter and symmetric nuclear matter,cannot be applied to neutron *** should return to the proper definition of the nuclear symmetry energy as a response of the nuclear system to small isospin imbalance from the Z=N nuclei and pure neutron matter.

关键词： symmetry energy nuclear interaction spin-isospin decomposition nuclear matter

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Semi-solid near-net shape rheocasting of heat treatable wrought aluminum alloys

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1719-1724页

作者： u.A.C uRlE Materials Science and Manufacturing Council for Scientific and Industrial Research

Flexibility of the CSIR-RCS, induction stirring with simultaneous air cooling process, in combination with high pressure die casting is successfully demonstrated by semi-solid rheocasting of plates performed on commercial 2024, 6082 and 7075 wrought aluminum alloys. Tensile properties were measured for the above mentioned rheocast wrought aluminum alloys in the T6 condition. The results showed that tensile properties were close to or even in some cases exceeded the minimum specifications. The yield strength and elongation of rheocast 2024-T6 exceeded the minimum requirements of the wrought alloy in the T6 condition but the ultimate tensile strength achieved only 90% of the specification because the Mg content of the starting alloy was below the commercial alloy specification. The strengths of rheocast 6082-T6 exceeded all of the wrought alloy T6 strength targets but the elongation only managed 36% of the required minimum due to porosity, caused by incipient melting during solution heat treatment, and the presence of fine intermetallie needles in the eutectic. The yield strength of rheocast 7075 exceeded the required one and the ultimate tensile strength also managed 97% of the specification; while the elongation only reached 46% of the minimum requirement also due to incipient melting porosity caused during the solution heat treatment process.

关键词： high pressure die casting (hPDC) aluminum alloys as-cast condition T6 treatment incipient melting

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Wavelet analysis of stagnation point flow of non-Newtonian nanofluid

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1211-1226页

作者： M.hAMID M.uSMAN R.u.hAQ4 Z.h.KhAN Wei WANG School of Mathematical Sciences Peking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Department of Electrical Engineering Bahria UniversityIslamabad 44000Pakistan State Key laboratory of hydraulics and Mountain River Engineering College of Water Resource & HydropowerSichuan UniversityChengdu 610065China Key laboratory of Advanced Reactor Engineering and Safety Ministry of Education Tsinghua UniversityBeijing 100084China

The wavelet approach is introduced to study the influence of the natural convection stagnation point flow of the Williamson fluid in the presence of thermophysical and Brownian motion effects. The thermal radiation effects are considered along a permeable stretching surface. The nonlinear problem is simulated numerically by using a novel algorithm based upon the Chebyshev wavelets. It is noticed that the velocity of the Williamson fluid increases for assisting flow cases while decreases for opposing flow cases when the unsteadiness and suction parameters increase, and the magnetic effect on the velocity increases for opposing flow cases while decreases for assisting flow cases. When the thermal radiation parameter, the Dufour number, and Williamson’s fluid parameter increase, the temperature increases for both assisting and opposing flow cases. Meanwhile, the temperature decreases when the Prandtl number increases. The concentration decreases when the Soret parameter increases, while increases when the Schmidt number increases. It is perceived that the assisting force decreases more than the opposing force. The findings endorse the credibility of the proposed algorithm, and could be extended to other nonlinear problems with complex nature.

关键词： Williamson nanofluid heat and mass transfer stagnation point flow assisting and opposing flow Chebyshev wavelet method

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Effects of an Intense laser Field and hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

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Chinese Physics letters 2011年第7期28卷 254-257页

作者： u.Yesil.ul F.ungan E.Kasapoglu h.Sari I.Sökmen Department of Physics Cumhuriyet University58140 SivasTurkey Department of Physics Dokuz Eylül University35160 IzmirTurkey

We have cal.ulated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic *** cal.ulations are performed within the effective mass approximation,using a variational *** conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum *** to the results obtained from the present work,it is deduced that(i)the binding energies of donor impurity decrease as the laser field increase,(ii)the binding energies of donor impurity increase as the hydrostatic pressure increase,(iii)the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases,(iv)the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field *** is hopeful that the obtained results will provide important improvements in device applications.

关键词： method hydrostatic donor

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Dual solutions in MhD stagnation-point flow of Prandtl fluid impinging on shrinking sheet

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Applied Mathematics and Mechanics(English Edition) 2014年第7期35卷 813-820页

作者： N.S.AKBAR Z.h.KhAN R.u.hAQ S.NADEEM Department of Basic Science & humanities College of Electrical & Mechanical Engineering(CEME) National University of Sciences and Technology Islamabad 46000 Pakistan School of Mathematical Sciences Peking University Department of Mathematics University of Malakand Khyber Pakhtunktwo 18800 Pakistan Department of Mathematics Quaid-i-Azam University Islamabad 44000 Pakistan

The present article investigates the dual nature of the solution of the magneto- hydrodynamic （MhD） stagnation-point flow of a Prandtl fluid model towards a shrinking surface. The self-similar nonlinear ordinary differential equations are solved numerically by the shooting： method. It is found that the dual solutions of the flow exist for cer- tain values of tile velocity ratio parameter. The special case of the first branch solutions （the classical Newtonian fluid model） is compared with the present numerical results of stretching flow. The results are found to be in good agreement. It is also shown that the boundary layer thickness for the second solution is thicker than that for the first solution.

关键词： stagnation-point flow shrinking sheet Prandtl fluid magnetohydrody-namic (MhD) dual solution shooting method

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