Materials Literature
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We report here our Raman studies on ${\mathrm{Fe}}_{3\ensuremath{-}x}{\mathrm{Zn}}_{x}{\mathrm{O}}_{4}(x=0,0.015,0.03)$ across the Verwey transition in the temperature range 20--300 K. The changes in Raman spectra as a function of doping show that the changes are gradual for samples with higher Zn doping. Allen's form…
We have studied the structural and electronic properties of Mg(1-x)Al(x)B2 within the Virtual Crystal Approximation (VCA) by means of first-principles total-energy calculations. Results for the lattice parameters, the electronic band structure, and the Fermi surface as a function of Al doping for 0
Numerical micropermeametry is performed on three dimensional porous samples having a linear size of approximately 3 mm and a resolution of 7.5 $μ$m. One of the samples is a microtomographic image of Fontainebleau sandstone. Two of the samples are stochastic reconstructions with the same porosity, specific surface area…
The thermal stability and melting behavior of ultrathin titanium nanowires with multi-shell cylindrical structures are studied using molecular dynamic simulation. The melting temperatures of titanium nanowires show remarkable dependence on wire sizes and structures. For the nanowire thinner than 1.2 nm, there is no cl…
We describe how we have used tight binding calculations as a quick, efficient tool to search for possible structures of Bi nanolines on Si(001). After identifying promising candidate structures, we have concentrated on these with \textit{ab initio} electronic structure techniques. The energetics of the tight binding a…
Stress resulting from mismatch between a substrate and an adsorbed material has often been thought to be the driving force for the self-assembly of nanoscale structures. Bi nanolines self-assemble on Si(001), and are remarkable for their straightness and length -- they are often more than 400 nm long, and a kink in a…
Tensile creep tests, tensile relaxation tests and a tensile test with a constant rate of strain are performed on injection-molded isotactic polypropylene at room temperature in the vicinity of the yield point. A constitutive model is derived for the time-dependent behavior of semi-crystalline polymers. A polymer is tr…
The influence of uniaxial anisotropy and the dipole interaction on the direction of the magnetization of ultra-thin ferromagnetic films in the ground-state is studied. The ground-state energy can be expressed in terms of anisotropy constants which are calculated in detail as function of the system parameters and the f…
Magnetic coupling between Ni_{81}Fe_{19} double thin films separated by an insulating SiO_{2} spacer layer is investigated with structural measurements, cross sectional imaging, magnetization measurements (BH loop) and transport under the conditions of variable spacer thickness ranging from 0 to 5000 Angstroms. We inv…
We study electron transport across a carbon molecular junction consisting of a ${\mathrm{C}}_{60}$ molecule sandwiched between two semi-infinite metallic carbon nanotubes. It is shown that the Landauer conductance of this carbon hybrid system can be tuned within orders of magnitude not only by varying the tube-${\math…
A set of theoretical atomic radii corresponding to the principal maximum in the radial distribution function, 4πr2R2 for the outermost orbital has been calculated for the ground state of 103 elements of the periodic table using Slater orbitals. The set of theoretical radii are found to reproduce the periodic law and t…
The role of long chains in shear-mediated crystallization was studied by in situ rheo-optical measurements and ex situ microscopic observations. To elucidate the effects of long chains, we prepared model blends in which fractionated isotactic polypropylene (iPP) (denoted L-PP) with high molecular weight (MW) and narro…
Collagen type I is the most abundant structural protein in tendon, skin and bone, and largely determines the mechanical behaviour of these connective tissues. To obtain a better understanding of the relationship between structure and mechanical properties, tensile tests and synchrotron X-ray scattering have been carri…
The term 'elastic protein' applies to many structural proteins with diverse functions and mechanical properties so there is room for confusion about its meaning. Elastic implies the property of elasticity, or the ability to deform reversibly without loss of energy; so elastic proteins should have high resilience. Anot…
In many disordered systems such as supercooled liquids the relaxation function does not decay exponentially with time. In this paper, it is shown from a consideration of the initial conditions that a system of identical molecules, each of which has the same non-exponential relaxation function, must be inhomogeneous. A…
Abstract Rubber‐toughened polystyrene has been extensively studied and is a well‐established technology. However, the use of thermoplastic elastomers to toughen polystyrene (PS) is new and has the potential for further investigations. In the present study, three EVAs (ethylene–vinyl acetate copolymers) with identical…
Abstract As soon as material failure dominates a deformation process, the material increasingly displays strain softening and the finite element computation is significantly affected by the element size. Without remedying this effect in the constitutive model one cannot hope for a reliable prediction of the ductile ma…
In this paper, we attempt to correlate the rate of corrosion at the metal surface with bulk solution properties such as electrical conductance, viscosity, and density. The premise is that the process solution environment within the pipe or refinery equipment controls the severity of the corrosion at the metal surface.…
The crystal structures of orotidine 5'-monophosphate decarboxylases from four different sources have been published recently. However, the detailed mechanism of catalysis of the most proficient enzyme known to date remains elusive. As the ligand-protein interactions at the orotate binding site are crucial to the under…
Reaction of Ir(NO)(PPh3)3 with anhydrous HCl results in addition of 2 equivalents of HCl with formal protonation of the nitrosyl ligand, affording the unusual six-co-ordinate nitroxyl complex cis,trans-IrHCl2(NH=O)(PPh3)2.