Materials Literature
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Local variations in filler particle concentration and/or shape and orientation in static filler/polymer composites are modelled as distributions of percolation thresholds. The concentration variations can be due to insufficient mixing, formation of semicrystalline voids during cooling from the melt, shrinkage during p…
The magnetic and transport properties of the Co2FeGa Heusler alloy have been investigated. The results show that the temperature dependence of the magnetization follows the spin-wave behaviour at low temperature. The electrical resistivity behaves according to a ~T2 power law, which may be mainly attributed to electro…
PART 1: TISSUE EXCHANGE AND TISSUE DEVELOPMENT 1. The State-of-the-Art in Tissue Exchange 2. Objectives of Tissue Engineering 3. Elements of Tissue Development PART 2: TISSUE ENGINEERING FUNDAMENTALS 4. Cell Growth and Differentiation 5. Cell and Tissue Mechanics 6. Cell Adhesion 7. Cell Migration 8. Cell Aggregation…
A real-time dynamically tunable-focus microlens array made from a polymer-liquid-crystal (LC) composite is demonstrated. The polymer was first patterned in microlens array cavities by lamination, and the LC-monomer mixture was then injected to the molded polymer cavities and finally stabilized by UV light-induced netw…
Fine (1.5 μm) aluminium trihydroxide (ATH), prepared from Bayer liquor, was subjected to dehydration at various temperatures up to 1400°C. The fine ATH was found to be gibbsitic in nature. XRD data indicated the formation of various transitional phases before becoming a stable α‐Al 2 O 3 phase. Boehmite phase formatio…
The relationship between structural and magnetic properties in stoichiometric pyrrhotite ${\text{Fe}}_{7}{\mathrm{S}}_{8}$ has been investigated using variable-temperature neutron-diffraction data. Below its magnetic ordering temperature, ${T}_{\mathrm{N}}=598(5)\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, ${\text{Fe}}_{7}…
We study experimentally the slow growth of a single crack in a fibrous material and observe stepwise growth dynamics. We model the material as a lattice where the crack is pinned by elastic traps and grows due to thermally activated stress fluctuations. In agreement with experimental data we find that the distribution…
First-principles calculations within the weighted density approximation (WDA) were performed for ground state properties of ferroelectric perovskites PbTiO$_3$, BaTiO$_3$, SrTiO$_3$, KNbO$_3$ and KTaO$_3$. We used the plane-wave pseudopotential method, a pair distribution function $G$ based on the uniform electron gas…
The discovery of a new beta-pyrochlore oxide superconductor CsOs2O6 with Tc = 3.3 K is reported. It is the third superconductor in the family of beta-pyrochlore oxides, following KOs2O6 with Tc = 9.6 K and RbOs2O6 with Tc = 6.3 K. The Tc of this series decreases with increasing the ionic radius of alkaline metal ions,…
Transport and magnetic measurements and structural and NMR studies have been carried out on (Pr1-yR'y)1-xAxCoO3 {R'=(rare earth elements and Y); A=(Ca, Ba and Sr)} at ambient pressure or under high pressure. The system exhibits a phase transition from a nearly metallic to an insulating state with decreasing temperatur…
We report a study of the photoconductivity (PC) induced in different types of diamonds (type IIa single crystals and CVD) by femtosecond XUV pulses (high order harmonics - up to 19th - of a titanium doped laser). We also reprot UPS spectras obtained with harmonics 13 to 29. Depending on the harmonic's order, the PC si…
Alkali metals are known as efficient promoters in heterogeneous catalysis but the nature of this phenomenon is as yet not understood. Our first principles calculations reveal a huge increase and delocalization of the isoelectronic reactivity index of Cu and Pd surfaces on alkali adsorption. We trace this phenomenon to…
We present a unified framework for the calculation of defect energies for those defects that can be represented as a superposition of isolated dislocations, and obtain both self and interaction energies of combinations of grain boundaries and cracks. We recover in special limits several well known quantities such as t…
Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a…
There is rapid growth in the use of MRI for molecular and cellular imaging. Much of this work relies on the high relaxivity of nanometer-sized, ultrasmall dextran-coated iron oxide particles. Typically, millions of dextran-coated ultrasmall iron oxide particles must be loaded into cells for efficient detection. Here w…
Abstract Recent experimental advances in the ability to grow epitaxial ferroelectrics on semiconductors have provided an opportunity to study the intrinsic properties of these interfaces. It has been reported that a heterostructure of BaTiO 3 grown on germanium has a commensurate crystalline oxide interface with a non…
The application of macroporous silicon to silicon bulk micromachining generally requires forming macropores locally on a silicon substrate according to a predefined pattern. In this work, several mask schemes, including photoresist, metal, silicon nitride (Si 3 N 4 ), silicon carbide (SiC) and silicon nitride/silicon…
In this paper we describe the utility of an acid-catalyzed isomerization reaction, specifically, ring-contraction of methylcyclohexane to an isomeric mixture of alkylcyclopentanes as a tool for characterizing the acidic properties of a wide range of platinum-loaded solid acids. Methylcyclohexane isomerization is parti…
The amino acid residue tryptophan 27 of 6,7-dimethyl-8-ribityllumazine synthase of the yeast Schizosaccharomyces pombe was replaced by tyrosine. The structures of the W27Y mutant protein in complex with riboflavin, the substrate analogue 5-nitroso-6-ribitylamino-2,4(1H,3H)-pyrimidinedione, and the product analogue 6-c…
This paper presents biodegradable polyesters prepared from gluconolactone (G) and citric acid (C) with various molar ratios of G to C, 1/4, 1/3, 1/2, 1/1, 2/1, 3/1, and 4/1. Corresponding polyesters were named as GC14, GC13, GC12, GC11, GC21, GC31, and GC41, respectively. Prepolymers, prepared at 165 °C by a melt poly…