Materials Literature
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We present molecular dynamics computer simulations of filaments of model non-Newtonian liquid stretched in a uniaxial deformation to the point of breaking. The liquid consists of Lennard-Jones monomers bound into chains of 100 monomers by nonlinear springs, and several different constant velocity and constant strain r…
The magnetic field affects the motion of electrons and the orientation of spins in solids, but it is believed to have little impact on the crystal structure. This common perception has been challenged recently by ferromagnetic shape-memory alloys, where the spin-lattice coupling is so strong that crystallographic axes…
The vibrational equivalent of the Anderson tight-binding Hamiltonian has been studied, with particular focus on the properties of the eigenstates at the transition from extended to localized states. The critical energy has been found approximately for several degrees of force-constant disorder using system-size scalin…
We present a simple model that allows hysteresis loops with exchange bias to be reproduced. The model is a modification of the T=0 random field Ising model driven by an external field and with synchronous local relaxation dynamics. The main novelty of the model is that a certain fraction f of the exchange constants be…
Abstract Oxide films grown anodically at the surface of superpure aluminium are used as standards to assess the accuracy of the thickness ( d XPS ) determined using the Beer–Lambert treatment of the Al 2p metal and oxide peak intensities. For the fitting conditions employed, the value of d XPS is found to be very clos…
Crack propagation studies in nanocrystalline Ni samples with mean grain sizes ranging from 5 to 12 nm are reported using atomistic simulations. For all grain sizes pure intergranular fracture is observed. Intergranular fracture is shown to proceed by the coalescence of microvoids formed at the grain boundaries ahead o…
The high temperature strengthening mechanism of previously manufactured 12Cr-ODS ferritic steel claddings was clarified. In the recrystallized 12Cr-2W-0.3Ti-0.24Y2O3-ODS ferritic steel cladding, αY2TiO5 type complex oxide formation was responsible for the drastic reduction of oxide particle size and the resulting shor…
Magneto-optical properties of ZnO:Co and ZnO:Ni films were measured. Magnetization measurements show that some of the films are paramagnetic and others are ferromagnetic. Magnetic circular dichroism clarified that Zn1-xCoxO and Zn1-xNixO included in samples are paramagnetic diluted magnetic semiconductors. Ferromagnet…
We propose a general strategy to develop accurate Force Fields (FF) for metallic systems derived from ab initio quantum mechanical (QM) calculations; we illustrate this approach for tantalum. As input data to the FF we use the linearized augmented plane wave method (LAPW) with the generalized gradient approximation (G…
A brief overview is given of the role of hydrogen trapping in hydrogen management of steel welding. The concept of hydrogen trapping is introduced in conjunction with efforts in reducing hydrogen cracking in steel welding. Appropriate selection of hydrogen traps offers the potential to control the content and distribu…
In spiders soluble proteins are converted to form insoluble silk fibres, stronger than steel. The final fibre product has long been the subject of study; however, little is known about the conversion process in the silk-producing gland of the spider. Here we describe a study of the conversion of the soluble form of th…
A four-dimensional (4-D) NMR study of Escherichia coli malate synthase G (MSG), a 723-residue monomeric enzyme (81.4 kDa), is described. Virtually complete backbone (1)HN, (15)N, (13)C, and (13)C(beta) chemical shift assignments of this largely alpha-helical protein are reported. The assignment strategy follows from o…
Abstract Pure Mg was oxidized in 20 kPa O 2 , at temperatures between room temperature and 400°C, for times ranging from 2 min to 60 h. The oxide layer was analysed by XPS. The samples were pre‐treated by mechanical polishing and ion etching. Oxidation was carried out in a furnace connected to the XPS instrument. Magn…
A review of recent developments made in the understanding of the electrical tree mechanism is presented. The life of the tree is covered from initiation, through propagation, to long-term changes in shape. The initiation process is examined in terms of the injection of space charge and its ability to transfer energy t…
Biodegradable thermoplastic starch (TPS)/clay hybrids were prepared by melt intercalation. Three organically modified montmorillonite (MMT) with different ammonium cations and one unmodified Na+ MMT (Cloisite Na+) were used. Cloisite Na+ showed the best dispersion in the TPS matrix. It was observed that the TPS/Cloisi…
A long-standing issue regarding the local and long-range structure of V(2)O(5)*nH(2)O xerogel has been successfully addressed. The full three-dimensional structure of the lamellar turbostratic V(2)O(5)*nH(2)O xerogel was determined by the atomic pair distribution function technique. We show that on the atomic scale th…
A number of inorganic and organic materials exhibit redox states (reduced and/or oxidised forms) with distinct UV-Visible (electronic) absorption bands. When electrochemical switching of these redox states gives rise to different colours (i.e. new or different visible region bands), the material is described as being…
A systematic study of various spark plasma sintering (SPS) parameters, namely temperature, holding time, heating rate, pressure, and pulse sequence, was conducted to investigate their effect on the densification, grain‐growth kinetics, hardness, and fracture toughness of a commercially available submicrometer‐sized Al…
Department of Chemistry, Bhavnagar University, Bhavnagar-364 002, India Department of Chemistry, Saurashtra University, Rajkot-360 005, India E-mail: phparsania@yahoo.com <em>Fax : </em>91-0281-578512 <em>Manuscript received 16 July 2001, accepted 6 February 2002</em> Several acoustical parameters of poly(4,4<em>'</em…
Abstract Polyamide (PA) and acrylonitrile/butadiene/styrene copolymer (ABS) may appear as a mixture in the recycled plastic stream. The incompatibility of these blends results in a blend with poor mechanical properties. The aim of this work is to partially convert the nitrile groups of the acrylonitrile/styrene copoly…