Materials physics and mechanics

RAR RUS 101-109 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

7003559440 0000-0003-2192-0386 Institute for Problems of Mechanical Engineering RAS Skiba Nikolai nikolay.skiba@gmail.com

St. Petersburg, Russia

Competition between nanoscale plastic deformation and fracture processes near triple junctions of grain boundaries in nanoceramics A theoretical model is suggested that describes competition between nanoscale plastic deformation and fracture processes in the situation with dislocation emission from grain boundaries and nanocrack generation at grain boundary disclinations in plastically deformed nanocrystalline materials. In the exemplary case of nanocrystalline silicon carbide (SiC) mechanically loaded at high temperatures, it is theoretically revealed that emission of Shockley dislocations from grain boundaries represents an energetically favorable process in certain ranges of parameters specifying defect structure. We compared the energy characteristics of the competing dislocation emission and nanocrack generation processes in stress fields of disclination dipoles. It is shown that emission of Shockley partials from grain boundaries in certain conditions serves as an effective channel for relaxation of the stress fields of disclination dipoles, in which case the emission process suppresses the nanocrack generation and thereby enhances ductility of nanocrystalline materials. nanoceramics; failure; grain boundary sliding; dislocations https://mpm.spbstu.ru/article/2012.23.1/ MPM_2012_14_2_P01.pdf

RAR RUS 110-128 Université de Sidi Bel Abbes Daouadji

Sidi Bel Abbes, Algérie

Université de Sidi Bel Abbes Tounsi

Sidi Bel Abbes, Algérie

Université de Sidi Bel Abbes Hadji

Sidi Bel Abbes, Algérie

Université de Sidi Bel Abbes Henni

Sidi Bel Abbes, Algérie

Université de Sidi Bel Abbes Abbes

Sidi Bel Abbes, Algérie

A theoretical analysis for static and dynamic behavior of functionally graded plates Theoretical formulation, Naviers solutions of rectangular plates based on a new higher order shear deformation model are presented for the static and dynamic analysis of functionally graded plates (FGPs). This theory enforces traction free boundary conditions at plate surfaces. Shear correction factors are not required because a correct representation of transverse shearing strain is given. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Numerical illustrations concern flexural behavior of FG plates with MetalCeramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fraction profiles, aspect ratios and length to thickness ratios. Results are verified with available results in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static and dynamic behavior of functionally graded plates. functionally graded material; power law index; volume fraction; higher-order shear deformation theory; Navier solution https://mpm.spbstu.ru/article/2012.23.2/ MPM_2012_14_2_P02.pdf

RAR RUS 129-136 Shri Sant Gadge Maharaj College Ravangave

India

Kumar Swami College Misal

India

Mahatma Basweshwar College Biradar

India

Dayanand Science College Rothod

India

Comparative study of structural, morphological and optical characterization of CdS, CdAlS and CdAlS annealed thin films Chemical Bath Deposition (CBD) technique was used for preparation of CdS, and Al doped CdS thin films. Al doped CdS films were annealed at different temperatures in air. CdS, as- deposited Al doped CdS and annealed Al doped CdS films were characterized using XRD, Scanning Electron Microscopy (SEM) and UV-Visible spectrophotometer. XRD study revealed the hexagonal phase of CdS and Al doped CdS material in the thin films. The XRD study shows that the hexagonal structure of CdS is not much affected with respect to Al doping. Al doped films annealed above 473 K crystalline phase of CdS transform into polycrystalline. The variations of lattice parameters and grain size with annealing temperature were investigated from XRD data. The % transmittance and optical band gap were investigated from optical data. The optical band gap of Al doped CdS films annealed at 473 K and 573 K is increased as compare to CdS (2.42 eV). Chemical Bath Deposition; CdS thin films; doping; optical band gap https://mpm.spbstu.ru/article/2012.23.3/ MPM_2012_14_2_P03.pdf

RAR RUS 137-144 Physics Research Centre, Mahatma Gandhi College Betkar

India

Physics Research Centre, Mahatma Gandhi College Bagde

India

Effect of complexing agent on spray deposited EuS thin films Complexing agent ethelene-diamine tetra acetic acid (EDTA) (sodium salt) is added in the aqueous solution of Europium chalcogenide (EuS) to deposit thin films on non-conductive glass substrates using spray pyrolysis technique at different substrate temperatures. The films synthesized were studied by XRD, SEM, EDAX and UV-Visible spectrometry. The effect of complexing agent was studied on morphological and optical properties. The XRD studies reveal that the material formed on glass substrates is europium sulphide, films are of polycrystalline in nature. The size for the deposited material is about 200 μm. The SEM studies show that total substrate surface uniformly covered by the film along with cracks. EDTA; EuS; spray pyrolysis; thin films; XRD https://mpm.spbstu.ru/article/2012.23.4/ MPM_2012_14_2_P04.pdf

RAR RUS 145-151 Anna University Suresh

India

Theoretical studies of solid state dielectric parameters of hydroxyapatite This paper deals with the theoretical study on the density of the hydroxyapatite (HAp). The solid state dielectric properties such as valence electron, plasma energy, Penn gap and Fermi energy were also evaluated for the HAp using the empirical relation. These estimated values were utilized to report the electronic polarizability and dielectric susceptibility of the HAp. Fermi energy; plasma energy; electronic polarizability; dielectric susceptibility https://mpm.spbstu.ru/article/2012.23.5/ MPM_2012_14_2_P05.pdf

RAR RUS 152-158 Anna University Suresh

India

Optical and transport properties of NLO Meta nitroaniline single crystals Single crystals of Meta nitroaniline (mNA) were grown successfully by slow evaporation technique. The as-grown crystal was clear, transparent and the size of the crystal attained was 8 x 4 x 3 mm3 within a period of 3 weeks. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their orthorhombic system. An attempt was made to calculate polarizability by Penn analysis and compare with the traditional method and results are tabulated. The optical properties of the grown crystal were calculated from UV-transmission spectrum analysis. Dielectric constant studies were carried out at different temperatures and frequencies. The second harmonic generation efficiency of the grown crystal was confirmed by Kurtz and Perry powder technique. solution growth; single crystal XRD; optical transmission; dielectric studies https://mpm.spbstu.ru/article/2012.23.6/ MPM_2012_14_2_P06.pdf

RAR RUS 159-180 59122315900 0000-0002-1572-2108 Kurukshetra University Kumar Rajneesh

Kurukshetra, India

Kurukshetra University Gupta

India

Reflection and transmission of plane waves at the interface of an elastic half-space and a micropolar thermoelastic half-space with fractional order derivative The problem of reflection and transmission due to longitudinal and transverse waves incident obliquely at a plane interface between uniform elastic solid half-space and micropolar thermoelastic solid half-space with fractional order derivative has been studied. It is found that the amplitude ratios of various reflected and transmitted waves are functions of angle of incidence, frequency of incident wave and are influenced by the fractional order and micropolar thermoelastic properties of media. The expressions of amplitude ratios and energy ratios have been computed numerically for a particular model. The variations of energy ratios for different fractional orders with angle of incidence for Lord-Shulman [1] and Green- Lindsay [2] theories of thermoelasticity are shown graphically for insulated boundary. The conservation of energy at the interface is verified. fractional calculus; micropolar thermoelasticity; elastic waves; reflection; transmission; amplitude and energy ratios https://mpm.spbstu.ru/article/2012.23.7/ MPM_2012_14_2_P07.pdf

RAR RUS 181-185 Anna University Suresh

India

Hindustan Institute of Technology Koteeswari

India

Loyola College Mani

India

Growth, mechanical, dielectric and photoconducting properties of bisglycine hydrobromide NLO single crystal Single crystals of Bisglycine Hydrobromide (BGHB) have been grown by slow evaporation technique. The unit cell dimensions and morphology of the grown crystals are confirmed by single crystal X-ray diffraction. The grown crystals were also subjected to microhardness. The microhardness studies indicate that the Vickers hardness number of the crystal decrease with the increase in applied load. Dielectric constant and dielectric loss measurements were carried out at different temperatures and frequencies. The photoconductivity studies confirm that the title compound has negative photoconductivity nature. solution growth; single crystal XRD; dielectric studies; photoconductivity studies https://mpm.spbstu.ru/article/2012.23.8/ MPM_2012_14_2_P08.pdf