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Nordic Rheology Conference 2000

Well-Characterized Low Viscosity Elastic Liquids

A series of low and constant viscosity elastic liquids are constructed and are studied rheologically. Steady shear viscosity and normal stresses, dynamic properties, and an apparent extensional viscosity are measured using well-established techniques. The rheological characteristics of the solution are used to help ex…

The Society’s Site: Time period September 2000 to March 2001

Thermomechanical Properties of Several Polymer Modified Asphalts

Costly deterioration of many roads and highways paved with asphalt generates a growing interest in polymer modified asphalts (PMA). Although asphalt represents only a fraction of asphalt paving mix, it is believed that it has a significant effect on the thermomechanical properties of asphalt pavements. Currently there…

Roughening of a propagating planar crack front

A numerical model of the front of a planar crack propagating between two connected elastic plates is investigated. The plates are modeled as square lattices of elastic beams. The plates are connected by similar but breakable beams with a randomly varying stiffness. The crack is driven by pulling both plates at one end…

First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams

Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B $56,$ 7905 (1997); $58,$ 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides…

Crystallization, structure solution and refinement of hen egg-white lysozyme at pH 8.0 in the presence of MPD

Hen egg-white lysozyme has been crystallized at slightly alkaline pH using 2-methyl-2,4-pentanediol (MPD) as the precipitant. The crystals are nearly isomorphous to crystals grown at acidic pH using sodium chloride as the precipitant. However, the growth kinetics differ markedly between the two conditions. The major r…

A delay of percolation time in carbon-black-filled conductive polymer composites

This work attempts to determine how percolation at an equilibrium state is correlated to percolation under experimental conditions. The dynamic process of forming conductive networks in carbon-black (CB)-filled poly(methyl methacrylate) composites was investigated by real-time tracing the time dependence of electrical…

The Integumentary Morphology of Modern Birds—An Overview

Avian integument is thin, elastic, and loosely attached to the body, giving birds the freedom of movement needed for flight. Its epidermis is both keratinized and lipogenic, and the skin as a whole acts as a sebaceous secretory organ. The skin is covered by feathers over most of the body, but many birds show colored b…

SUBGROUPGRAPH: a computer program for analysis of group–subgroup relations between space groups

The main aim of SUBGROUPGRAPH is a detailed study of a group–subgroup relation between two space groups, G > H, including the construction of chains of maximal subgroups for G > H for a specified/non-specified index i = |G:H| (the so-called G–H graph), the determination of the number of the different Hk < G, Hk ≅ H…

Static hyperpolarizability of the water dimer and the interaction hyperpolarizability of two water molecules

We report an extensive investigation of the electric dipole moment (μα), static polarizability (ααβ), and hyperpolarizability (βαβγ and γαβγδ) of the water dimer. Calculations were performed at both rigid and relaxed monomer geometries. At the rigid monomer geometry (RIMG), a very large [9s6p6d4f/6s5p3d2 f] basis set…

Critical size and anomalous lattice expansion in nanocrystallineBaTiO3particles

Nanocrystalline barium titanate particles are prepared by the alkoxide method. The lattice constants are obtained from the electron diffraction patterns for various orientations of single particles in the size range of 15--250 nm in diameter. The present result indicates that the structural change from a tetragonal (f…

Energetic, vibrational, and electronic properties of silicon using a nonorthogonal tight-binding model

We present calculations of energetic, electronic, and vibrational properties of silicon using a nonorthogonal tight-binding (TB) model derived to fit accurately first-principles calculations. Although it was fit only to a few high-symmetry bulk structures, the model can be successfully used to compute the energies and…

Corrosion and Protection of Magnesium Alloys

The oxide film on magnesium offers considerable surface protection in rural and some industrial environments and the corrosion rate lies between that of aluminum and low carbon steels. Galvanic coupling of magnesium alloys, high impurity content such as Ni, Fe, Cu and surface contamination are detrimental for corrosio…

Rapid detection of polyhydroxyalkanoate-accumulating bacteria isolated from the environment by colony PCR

Colony PCR and semi-nested PCR techniques were employed for screening polyhydroxyalkanoate (PHA) producers isolated from the environment. Three degenerate primers were designed based on multiple sequence alignment results and were used as PCR primers to detect PHA synthase genes. Optimized colony PCR conditions were a…

Fourier-modal methods applied to waveguide computational problems

Rigorous coupled-wave analysis (also called the Fourier-modal method) is an efficient tool for the numerical analysis of grating diffraction problems. We show that, with only a few modifications, this method can be used efficiently for the numerical analysis of aperiodic diffraction problems, including photonic crysta…

Silica glass: A material for photonics

Recent studies on two aspects of silica glass as a photonic material will be described. Part A of this review will be focused on structural disorder and structural relaxations in silica glass. With regard to the structural disorder, investigations have been made to improve transparency and to shift the optical absorpt…

Glass fiber reinforced polyamide‐6 nanocomposites

Abstract Polyamide 6 nanocomposites (PA6/NC) are novel type of composite materials comprising extremely thin, “nanometer scale” dispersions of smectitic silicate platelets. We prepared such PA6/NC materials via a melt compounding technique using suitably organomodified montmorillonite or hectorite type clays. The high…

Circular photogalvanic effect induced by monopolar spin orientation in p-GaAs/AlGaAs MQW

The circular photogalvanic effect (CPGE) has been observed in (100)-oriented $p$-GaAs/AlGaAs quantum wells at normal incidence of far-infrared radiation. It is shown that monopolar optical spin orientation of free carriers causes an electric current which reverses its direction upon changing from left to right circula…

An elastic model for the In-In correlations in In(x)Ga(1-x)As semiconductor alloys

Deviations from randomicity in In(x)Ga(1-x) As semiconductor alloys induced by elastic effects are investigated within the Keating potential. Our model is based on Monte Carlo simulations on large (4096 atoms) supercells, performed with two types of boundary conditions: Fully periodic boundary conditions represent the…