Materials Literature
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A series of MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O (MnNCKFMASH) metapelite pseudosections highlights the dependence of predicted mineral assemblages on bulk rock Al2O3 and Mg# [MgO/(MgO + FeO)]. T-XAl pseudosections portray the dependence of staurolite, biotite, and aluminum silicate on Al2O3 content, allowing the di…
The fraction of O atoms as non-bridging O atoms (NBO) can be well approximated based on composition alone in many silicate glasses, but the NBO preference for specific network forming cations is much less well known. Using oxygen-17 ( 17 O) NMR on low-silica calcium aluminosilicate (CAS) glasses, this study shows that…
In this article, we examine the Fowler–Nordheim (FN) equation for field emission using pedagogical models to introduce and illuminate its origins, limitations, extensions, and application to multidimensional structures. The analyses of modern electron sources generally invoke either the FN equation or the Richardson–L…
Four sets of random propylene-based copolymers with 1−10 mol % of ethylene, 1-butene, 1-hexene, or 1-octene as co-units, synthesized with the same metallocene catalyst, were investigated by differential scanning calorimetry and wide-angle X-ray scattering following rapid and isothermal crystallization. Parameters rela…
Amphiphilic AB and ABA block copolymers have been prepared from poly (ortho esters) and poly (ethylene glycol). Such block copolymers readily form micellar dispersions in water, or buffers. The CMC is in the range of 3 x 10(-4)-5 x 10(-4) g/l which is a value low enough to assure retention of micelle integrity upon in…
It is well known that the optically measured lengths of fission tracks in apatite crystals are a function of etching conditions, crystallographic orientation of the track, composition of the crystal, and the state of thermal annealing. In this study we standardize etching conditions and optimize track length measurabi…
The excellent optoelectronic, mechanical, and thermal properties of carbon nanotubes have made them very attractive for a wide range of potential applications. However, many applications require the growth of aligned carbon nanotubes with surface modification. We have developed a simple pyrolytic method for large-scal…
Abstract Migration of compounding ingredients is an important factor in the overall properties and performance of rubber articles containing a number of layers for example, a tire, a hose or a conveyor belt. In certain cases, migration of compounding ingredients before, during and after vulcanization in rubber compoun…
Mixtures of rodlike and disklike liquid crystals suffer from phase separation. However, such mixtures can be homogenized if a molecule is added which comprises a rod- and a disklike fragment linked together covalently. We have termed such a molecule a shape amphiphile and believe that this represents a new class of am…
In order to investigate the relationship between the susceptibility of primary water stress corrosion cracking (PWSCC) in Alloy 600 and the content of dissolved hydrogen (DH) in the primary water of pressurized water reactors (PWR), structural analysis of oxide films formed under four different DH conditions in simula…
In local drug delivery, nanoparticles based on biodegradable polymers can function as vehicles with controlled drug-release properties. To achieve a well-controlled drug-release profile, control over the particle size is of great importance. Therefore, biodegradable polyester nanoparticles were prepared by the salting…
Abstract This paper introduces an approach where the match of two different length scales, i.e., pattern from self‐assembly of block copolymer micelles (< 100 nm) and electron‐beam (e‐beam) writing (> 50 nm), allow the grouping of nanometer‐sized gold clusters in very small numbers in even aperiodic pattern and…
We have studied the reaction kinetics of ten manganese porphyrins, differing in their meso substituents, with peroxynitrite (ONOO-) and carbonate radical anion (CO3.) using stopped-flow and pulse radiolysis, respectively. Rate constants for the reactions of Mn(III) porphyrins with ONOO- ranged from 1 x 10(5) to 3.4 x…
For sparse materials like graphitic systems and carbon nanotubes the standard density functional theory (DFT) faces significant problems because it cannot accurately describe the van der Waals interactions that are essential to the carbon-nanostructure materials behavior. While standard implementations of DFT can desc…
We discuss a new narrow-gap ferromagnetic (FM) semiconductor alloy, In(1-x)Mn(x)Sb, and its growth by low-temperature molecular-beam epitaxy. The magnetic properties were investigated by direct magnetization measurements, electrical transport, magnetic circular dichroism, and the magneto-optical Kerr effect. These dat…
Spin-orbit coupling effects are studied in quantum dots in InSb, a narrow-gap material. Competition between different Rashba and Dresselhaus terms is shown to produce wholesale changes in the spectrum. The large (and negative) $g$-factor and the Rashba field produce states where spin is no longer a good quantum number…
Fine-scale probes of many complex electronic materials have revealed a non-uniform nanoworld of sign-varying textures in strain, charge and magnetization, forming meandering ribbons, stripe segments or droplets. We introduce and simulate a Ginzburg-Landau model for a structural transition, with strains coupling to cha…
Protonation of fourth-generation poly(amidoamine) dendrimers terminated with hydroxyl and amine functional groups has been studied by potentiometric pH titration. The titration data are analyzed using a multishell structural model and a Frumkin adsorption isotherm to approximate proton−dendrimer binding equilibria. Si…
The precise stoichiometry required for the acetylation of surface amines of a poly(amidoamine) (PAMAM) dendrimer generation 5 (G5) was verified by using potentiometric titration, gel permeation chromatography, and nuclear magnetic resonance spectroscopy. The average number of primary amine groups, absolute molecular w…
A fascinating structural transformation occurring inside single-walled carbon nanotubes (SWNTs) is the fullerene coalescence, which is responsible for forming stable zeppelinlike carbon molecules. We report in situ transmission electron microscope (TEM) observations revealing sequences of fullerene coalescence induced…