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Cracking in orthotropic half-plane with a functionally graded coating under anti-plane loading

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Acta mechanica Solida Sinica 2015年第2期28卷 210-220页

作者： m. m. monfared m. Ayatollahi Faculty of Engineering University of Zanjan

This investigation evaluates, by the dislocation method, the dynamic stress intensity factors of cracked orthotropic half-plane and functionally graded material coating of a coating- substrate material due to the action of anti-plane traction on the crack surfaces. First, by using the complex Fourier transform, the dislocation problem can be solved and the stress fields are obtained with Cauchy singularity at the location of dislocation. The dislocation solution is utilized to derive integral equations for multiple interacting cracks in the orthotropic half-plane with functionally graded orthotropic coating. Several examples are solved and dynamic stress intensity factors are obtained.

关键词： orthotropic half-plane multiple cracks functionally graded coating

SWELLING BEHAVIOR OF ACRYLAmIDE HYDROGEL IN DIFFERENT SOLVENTS AND pHs

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Chinese Journal of Polymer Science 2005年第3期23卷 269-274页

作者： m.F.mina m.m.Alam Institute of Nuclear Science and Technology Atomic Energy Research EstablishmentGPO Box-3787Dhaka-1000BangladeshInstitute of Nuclear Science and TechnologyAtomic Energy Research EstablishmentGPO Box-3787Dhaka-1000Bangladesh

Swelling property of acrylamide hydrogels,prepared from aqueous solutions of acrylamide monomer havingconcentrations in the range of 10-60 wt% by ray irradiation method using a Co-60 gamma radiation source at dosesranging 1-30.0 kGy,has been investigated under various swelling *** swelling media were basically solvents(solutions),produced by dissolving methanol,ethanol,glucose,sucrose,sodium chloride and sodium persulfate individuallywith distilled water,and solutions prepared with pHs=3,7 and *** investigation was performed in order to observe theeffect of these solvents and pHs as well as the influence of monomer concentrations,radiation doses and times on swellingbehavior of *** values were found higher for hydrogels prepared with lower monomer concentrations(ca.20 wt%)and radiation doses(ca.5 kGy)and showed a leveling off tendency within 24 *** glucose solvent and the buffersolution of pH=10 revealed significant increase of swelling of hydrogels as compared to other *** areexplained based on crosslinking density in hydrogel,polymer-solvent/polymer-polymer interactions in solutions,permeability of molecules in solutions and ionization capacity of hydrogel in pH.

关键词： Acrylamide Hydrogel Co-60 gamma radiation source Swelling.

Plasma Treatment of Natural Jute Fibre by RIE 80 plus Plasma Tool

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Plasma Science and Technology 2010年第3期12卷 325-329页

作者： m.m.mORSHED m.m.ALAm S.m.DANIELS National Centre for Plasma Science and Technology Dublin City University Nanomaterials Processing Laboratory School of Electronic EngineeringDublin City University

Plasma treatment can be used to modify the structure of natural fibre like jute for a variety of applications. Environmentally friendly jute fibre was treated with argon and oxygen plasma. The treated samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and optical microscope. The macromolecular and microstructural changes in cellulose confirmed the change by plasma treatment. The XRD results confirmed that the crystal size and the crystallinity of the plasma treated fibre increased. Argon plasma treated fibre had a smooth and compact surface, compared to oxygen plasma treated fibre. The maximum stain （i.e. stress） concentrated in the oxygen plasma treated fibre. Optical micrographs showed the oxygen plasma treated fibre tended to rupture due to higher strain （i.e., stress） compared to fibre with argon plasma treatment. FTIR results also provided the evidence of change in the chemical constituents with plasma treatment.

关键词： natural jute fibre plasma treatment crystallinity chemical composition

Interactions of ion acoustic multi-soliton and rogue wave with Bohm quantum potential in degenerate plasma

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Chinese Physics B 2017年第9期26卷 301-309页

作者： m S Alam m G Hafez m R Talukder m Hossain Ali Department of Applied mathematics University of RajshahiRajshahi-6205Bangladesh Plasma Science and Technology Lab Department of Applied Physics and Electronic EngineeringUniversity of RajshahiRajshahi-6205Bangladesh Department of mathematics Chittagong University of Engineering and TechnologyChittagong-4349Bangladesh

This work investigates the interactions among solitons and their consequences in the production of rogue waves in an unmagnetized plasmas composing non-relativistic as well as relativistic degenerate electrons and positrons, and inertial non-relativistic helium ions. The extended Poincare′–Lighthill–Kuo（PLK） method is employed to derive the two-sided Korteweg–de Vries（KdV） equations with their corresponding phase shifts. The nonlinear Schrodinger equation（NLSE） is obtained from the modified Kd V（mKdV） equation, which allows one to study the properties of the rogue waves. It is found that the Fermi temperature and quantum mechanical effects become pronounced due to the quantum diffraction of electrons and positrons in the plasmas. The densities and temperatures of the helium ions, degenerate electrons and positrons, and quantum parameters strongly modify the electrostatic ion acoustic resonances and their corresponding phase shifts due to the interactions among solitons and produce rogue waves in the plasma.

关键词： wave-wave interaction rogue waves degenerate plasmas Bohm potential

Band gap engineered polymeric-inorganic nanocomposite catalysts:Synthesis, isothermal stability, photocatalytic activity and photovoltaic performance

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Journal of materials Science & Technology 2017年第6期33卷 547-557页

作者： Umair Baig m.A.Gondal A.m.Ilyas m.m.Sanagi Laser Research Group Physics Department & Center of Excellence in Nanotechnology King Fahd University of Petroleum and Minerals Center of Excellence for Scientific Research Collaboration with mIT King Fahd University of Petroleum and Minerals Deparment of Chemistry Faculty of Science Universiti Technologi Malaysia

Polymeric-inorganic nanocomposite catalysts were synthesized by facile one-pot chemical polymerization of pyrrole in the presence of titanium dioxide nanoparticles. The electrical, optical, photovoltaic performance of dye sensitized solar cell（DSSC） and visible light driven photocatalytic activities of the nanocomposite were investigated. The prepared nanocomposite displays excellent photo-activity, attaining 100% degradation of methyl orange dye in 60 min under visible light source while 55% for pure TiO_2 under similar experimental conditions. The photovoltaic performance of the polypyrrole-titanium dioxide（PPy-TiO_2） nanocomposite has a 51.4% improvement with a photo-conversion efficiency of 8.07% as compared to pure TiO_2 based DSSC. By comparing the physical mixture of the PPy-TiO_2 nanocomposite and pristine TiO_2, the enhanced activity of the PPy-TiO_2 nanocomposite can be attributed to the reduced charge transfer resistance, outstanding electrical conductance of the PPy, the nano-sized structure of TiO_2 and their synergetic effect. Furthermore, the PPy-TiO_2 nanocomposite shows excellent electrical conductivity and isothermal stability under ambient conditions below 110？C.

关键词： Nanocomposite Electrical conductivity Isothermal stability Visible light active Photo-degradation

Quantum pseudodots under the influence of external vector and scalar fields

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Chinese Physics B 2018年第8期27卷 109-117页

作者： m Eshghi S m Ikhdairt Department of Physics Imam Hossein Comprehensive UniversityTehranIran Department of Physics Faculty of ScienceAn-Najah National UniversityNablusPalestine Department of Electrical Engineering Near East UniversityNicosiaNorthern CyprusMersin 10Turkey

We study the spherical quantum pseudodots in the Schr6dinger equation by using the pseudo-harmonic plus harmonic oscillator potentials considering the effect of the external electric and magnetic fields. The finite energy levels and the wave functions are calculated. Furthermore, the behavior of the essential thermodynamic quantities such as, the free energy, the mean energy, the entropy, the specific heat, the magnetization, the magnetic susceptibility, and the persistent currents are also studied by using the characteristic function. Our analytical results are found to be in good agreement with the other works. The numerical results on the energy levels as well as the thermodynamic quantities have also been given.

关键词： Schr6dinger equation harmonic oscillator pseudo-harmonic potential thermodynamic quantities quantum pseudo-dots characteristic function

Removal of organic pollutants by lanthanide-doped mIL-53(Fe) metal-organic frameworks:Effect of dopant type in magnetite precursor

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Journal of Rare Earths 2023年第1期41卷 140-148页

作者： Shimaa m.Ali Khadija m.Emran Fedaa m.m.Alrashedee Department of Chemistry Faculty of ScienceCairo University.Giza12613Egypt Department of Chemistry Faculty of ScienceTaibah UniversityMadinah30002Saudi Arabia

A series of undoped and lanthanide doped mIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(mOFs) were prepared by the solvothermal *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET) measurements,scanning electron microscopy(SEm),and thermal *** and FT-IR results ascertain the successful mOF formation for all prepared ***-53(Fe)/La-Fe_(3)O_(4) has the smallest particle size of 8.6 nm,the largest BET surface area of 54.2 m^(2)/g,and the highest *** and different lanthanide doped mIL-53(Fe) we re employed as sorbents for the removal of methylene blue(mB)dye from aqueous solutions to examine the doping benefit and the effect of the dopant size on the sorption *** causes mOFs to act as pH-independent sorbents,which make it applicable at any *** follows pseudo-second-order kinetic model,and doped sorbents attain equilibrium *** isotherms are followed,except for mIL-53(Fe)/La-Fe_(3)O_(4).The adsorption capacity increases with increasing the dopant ion size,100.5 mg/g for La-doped mOF,which is about four times higher than that of undoped *** adsorption mechanism involves chemical interactions between Lewis acid in magnetite mIL-53(Fe) series and Lewis base in mB.

关键词： Lanthanide metal organic framework Adsorption Doping Organic dyes Rare earths

Dye-sensitized solar cells based on Cr-doped TiO2 nanotube photoanodes

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Rare metals 2017年第11期36卷 865-871页

作者： m. m. momeni Department of Chemistry Isfahan University of TechnologyIsfahan 84156-83111 Iran

The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEm）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.

关键词： Dye-sensitized solar cell Photoanodes Nanotubes Anodization

New ordered mAX phase mo_2 TiAlC_2: Elastic and electronic properties from first-principles

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Chinese Physics B 2016年第10期25卷 323-329页

作者： m A Hadi m S Ali Department of Physics University of Rajshahi Department of Physics Pabna University of Science and Technology

First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered mAX phase carbide mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new mAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional mo–C–mo covalent bonding associated with a relatively weak Ti–C *** calculated Fermi surface is due to the low-dispersive mo 4d-like bands, which makes the compound a conductive *** hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.

关键词： new ordered mAX phase density functional theory calculations Debye temperature Vickers hardness