Materials Literature
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This paper aims to explain the size-effect in the Primary Deformation Zone (PDZ) in machining using strain gradient plasticity theory. Considering a parallel-sided shear zone configuration, models are formulated for the evaluation of strain gradient, density of geometrically necessary dislocations, shear strength and…
We have studied the interactions in the solid phase between a blue-light-emitting organic conjugated polymer {poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(9,ethyl-3,6-carbazole)]} and colloidal CdSe∕ZnS core shell quantum dots. We demonstrate by time resolved photoluminescence measurements that efficient Förster energ…
We report the synthesis and characterization of ferroelectric lead zirconate titanate Pb(Zr0.53Ti0.47)O3 (PZT) nanowires. The PZT nanowires, with diameters of about 45nm and lengths of about 6μm, were fabricated by means of a sol-gel method utilizing nanochannel alumina templates. After postannealing at 700°C, the PZT…
Biodegradable nanocomposites were successfully fabricated from cellulose acetate (CA) plasticized with triethyl citrate (TEC), and combined with Cloisite 30B organoclay, using maleic anhydride grafted cellulose acetate butyrate (CAB- g -MA) as the compatibilizer. The nanostructure of the nanocomposites was investigate…
The formation of pure single crystalline silicon nanoparticles by microwave induced decomposition of silane in a low pressure flow reactor is reported. The morphology and crystal structure of the particles are characterized in situ by particle mass spectrometry (PMS) and ex situ by means of X-ray diffraction, high res…
We study ground state properties of the double-exchange model on triangle chain in the classical limit on $t_{2g}$ spins. The ground state is determined by a competition among the kinetic energy of the $e_g$ electron, the antiferromagnetic exchange energy between the $t_{2g}$ spins, and frustration due to a geometric…
Absolute negative refraction regions for both polarizations of electromagnetic wave in two-dimensional photonic crystal have been found through both the analysis and the exact numerical simulation. Especially, absolute all-angle negative refraction for both polarizations has also been demonstrated. Thus, the focusing…
We present a tight-binding based GW approach for the calculation of quasiparticle energy levels in confined systems such as molecules. Key quantities in the GW formalism like the microscopic dielectric function or the screened Coulomb interaction are expressed in a minimal basis of spherically averaged atomic orbitals…
We present a theoretical formulation of the one-electron problem constrained on the surface of a cylindrical tubule with varying diameter. Because of the cylindrical symmetry, we may reduce the problem to a one-dimensional equation for each angular momentum quantum number $m$ along the cylindrical axis. The geometrica…
Anharmonicity of the interatomic potential is taken into account for the quantitative simulation of the conduction and valence band offsets for strained semiconductor heterostructures. The anharmonicity leads to a weaker compressive hydrostatic strain than that obtained with the commonly used quasiharmonic approximati…
Abstract To avoid the complex core surface functionalization or pretreatment that is necessary in order to coat latex and silica colloids with a uniform, complete metal shell, the solvent‐assisted route has been explored to prepare a complete metal (Ag or Au) shell with controlled thickness on polystyrene (PS) colloid…
Abstract It is thought that morphologies of bacterial carbonates can be used to identify microbial fossils and/or precipitates in sediments and rocks. This study shows that calcite and vaterite formed in a gel medium in the presence of Myxococcus xanthus display a range of morphologies that depend on whether the bacte…
The Peierls stress of the a/2⟨110⟩ screw dislocation belonging to the shuffle set is calculated for silicon using density functional theory. We have checked the effect of boundary conditions by using two models, the supercell method where one considers a periodic array of dislocations, and the cluster method where a s…
The diffusion length of minority carriers L p,n is an important characterisation parameter in semiconductor materials and is of particular interest when constructing devices such as solar cells (Hovel 1975), double hetero junction lasers (Casey and Panish 1978) and bipolar transistors. Their efficiency depends primari…
An ab initio pseudopotential calculation using density functional theory within the local density approximation has been performed to investigate the electronic properties of TlSe, which is of chainlike crystal geometry. The energy bands and effective masses along high symmetry directions, the density of states, and v…
Fe 3+ /ΣFe ratios were determined from Mössbauer spectra recorded for a series of 17 anorthitediopside eutectic glasses containing 1 wt% 57 Fe 2 O 3 quenched from melts equilibrated over a range of oxygen fugacities from f O₂ ~ 10 5 bars (Fe 3+ /ΣFe = 1) to 10 -13 bars (Fe 3+ /ΣFe = 0) at 1682 K. Fe 3+ /Fe 2+ was foun…
We report ferromagnetism at over 900K in Cr–GaN and Cr–AlN thin films. The magnetic properties vary as a function of Cr concentration with 60%, and 20%, of the Cr being magnetically active at 3% doping in GaN, and 7% in AlN, respectively. In the GaN sample with the highest magnetically active Cr (60%), channeling Ruth…
Gel electrophoresis and column chromatography conducted on individually dispersed, ultrasonicated single-walled carbon nanotubes yield simultaneous separation by tube length and diameter. Electroelution after electrophoresis is shown to produce highly resolved fractions of nanotubes with average lengths between 92 and…
Energy recovery and nutrient reuse from sewage sludge has traditionally been achieved via anaerobic digestion/power generation with land application of the biosolids. By contrast, thermal processes such as pyrolysis have typically been used only for energy recovery. One such technology has demonstrated at commercial s…
A pseudocubic, paramagnetic cluster of ReII and MnII, [{MnCl}4{Re(triphos)(CN)3}4], has been prepared, and its magnetic properties have been investigated. Antiferromagnetic coupling is observed between the "S = 1/2" ReII and S = 5/2 MnII centers resulting in an effective S = 8 ground state. AC susceptibility studies r…