Materials Literature
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The oxidation of five polyamines (ethylenediamine, putrescine, cadaverine, spermine, and spermidine) was investigated at polycrystalline, boron-doped, diamond thin-film electrodes using cyclic voltammetry and flow injection analysis (FIA) with amperometric detection. Cyclic voltammetry of the polyamines was conducted…
Vapour cavities in liquid flows have long been associated with cavitation damage to nearby solid surfaces and it is thought that the final stage of collapse, when a high- speed liquid jet threads the cavity, plays a vital role in this process. The present study investigates this aspect of the motion of laser-generated…
Optically Stimulated Luminescence (OSL) dosimetry is attractive to the health physics and dosimetry community due to its all-optical character, fast data acquisition and the avoidance of heating the detector. Until recently there was no luminescent material sensitive enough to radiation, and at the same time suitable…
Experimental solubilities are reported for anthracene dissolved in ternary 2-ethoxyethanol + cyclohexane + heptane, 2-ethoxyethanol + cyclohexane + 2,2,4-trimethylpentane, 2-butoxyethanol + cyclohexane + heptane, and 2-butoxyethanol + cyclohexane + 2,2,4-trimethylpentane solvent mixtures at 25 °C. Nineteen composition…
The purpose of this study was to purify, crystallize, and characterize by X-ray diffraction an amaranth globulin for its subsequent structure elucidation. A 36-kDa amaranth globulin was extracted by sequential precipitation and purified by gel filtration and cationic exchange columns. It was crystallized at 18 degrees…
This report deals with the different transition metal- and alkali cation-assisted oxidation pathways of the meso- octaethylporphyrinogen tetraanion [Et 8 N 4 ] 4 - . The two-electron oxidation of [Et 8 N 4 Mn{Na(thf) 2 } 2 ], 4, with Cp 2 FeBPh 4 led to the corresponding monocyclopropane derivative [Et 8 N 4 (Δ)Mn], 6…
3,4-Bis(trimethylsilyl)-1H-pyrrole (5) was employed as a key precursor to generate a highly strained and reactive five-membered cyclic cumulene, namely 1-tert-butoxycarbonyl-3,4-didehydro-1H-pyrrole (4). The transient existence of 4 at room temperature was confirmed by trapping reactions with furan, acrylonitrile, and…
Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to study the size and distribution of nanometer-sized metallic particles of four Cu/SiO 2 model catalyst systems. The systems were constructed by spin coating copper(II) acetate [Cu(CH 3 CO 2 ) 2 ·H 2 O, Cu(ac) 2 ] solutions of varying…
Foams have unique rheological properties that range from solid-like to fluid-like. We study two-dimensional non-coarsening foams of different disorder under shear in a Monte Carlo simulation, using a driven large-Q Potts model. We find that the dynamics of topological rearrangements depend sensitively on the structura…
The implementation of an ultrasonic method of evaluation of composite plates requires a good knowledge of the interaction of ultrasonic beam emitted by the transducers, with such a plate immersed in a fluid. The model of ultrasonic propagation in anisotropic multilayered materials developed here makes the study of thi…
We propose an alternative approach to self-diffusion in an atomic liquid. Our starting point is an oscillatory motion of a tagged particle in its first solvation shell (cage). Only after cage relaxation is taken into account is the tagged particle able to diffuse. This approach is suitable for describing liquids where…
Tunneling spectroscopy of ${\mathrm{Al}}_{73}{\mathrm{Ni}}_{17}{\mathrm{Co}}_{10}$ decagonal single quasicrystals has been measured at ultralow temperatures. In addition to the wide pseudogap observed in previous photoemission experiments, very rich fine structures in the density of states around the Fermi energy were…
A generalized random sequential adsorption (RSA) approach is developed by taking into account diffusion, particle/wall hydrodynamic interactions as well as external forces (e.g., gravity). In analogy to the previous concept of Pagonabarraga and Rubı́ [Physica A 188, 553 (1992)] the position dependent available surface…
Exposure of Rh(111) to atomic oxygen leads to the facile formation of a full-coverage and ordered (1×1)-O monolayer which is stable at room temperature. This result differs markedly from the half-coverage (2×1)-O overlayer which forms at saturation when using molecular oxygen. This demonstrates that kinetic rather tha…
We present a new Monte Carlo scheme for the efficient simulation of multi-polymer systems. The method permits chains to be inserted into the system using a biased growth technique. The growth proceeds via the use of a retractable feeler, which probes possible pathways ahead of the growing chain. By recoiling from trap…
A new model is presented for the mesoscale modelling of grain–boundary motion. Grain boundaries are treated as regions of disorder across which orientation parameters change. The framework uses a set of lattice parameters to track grain orientation, and this is done with fewer equations than the more standard approach…
The precursor state involved in the initial stages of ${\mathrm{O}}_{2}$ reaction with a $\mathrm{Si}(111)\ensuremath{-}(7\ifmmode\times\else\texttimes\fi{}7)$ surface has been a long standing problem. Using the ${\mathrm{Cs}}^{+}$ reactive scattering technique, we unambiguously show that the precursor is molecular Si…
The spontaneous ultraviolet luminescence reported [G. M. Irwin and K. H. Kim, Phys. Rev. Lett. 79, 990 (1997); D. S. Richardson et al., ibid. 80, 3206 (1998)] from ${}^{233}\mathrm{uranium}$ compounds and ascribed to an ultraviolet gamma-ray emission from the metastable ${}^{229}\mathrm{thorium}$ daughter is actually…
The conditions for formation of subsurface oxygen on the Ru(0001) surface have been studied using thermal desorption spectroscopy, low energy electron diffraction (LEED) and specular helium scattering. The incorporation of oxygen has been performed via dissociative chemisorption of three molecular carriers of atomic o…
Spreading of perfluoropolyalkylether thin films on amorphous carbon surfaces has been studied by scanning microellipsometry. Two types of perfluoropolyalkylethers with the same main-chain structure and various molecular weights (between 1000 and 6000 g/mol) were used: Zdol, with OH functional end groups, and Z, with n…