Materials Literature
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Removal of oxygen ions by thermogravimetric methods in $\mathrm{CaMn}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ ($0<~\ensuremath{\delta}<~0.34$) produces electron doping of the material and ${\mathrm{Mn}}^{4+}$ ions are reduced to a trivalent state. Electrical resistivity measurements in samples with con…
The crystalline structure of dried cotton fibers at varying development stages has been investigated using wide angle x-ray diffraction (WAXS) techniques. The cellulose I crystalline structure has been confirmed on dried SJ-2 Acala cotton fibers collected at varying developmental stages and at maturity. The cellulose…
The microstructures of lithiated graphite were studied using high‐resolution transmission electron microscopy (HRTEM) and x‐ray diffraction (XRD). HRTEM shows lattice images of the (001) layers of with layer spacing of 3.70 Å, consistent with XRD. The morphology and distribution of the and phases were investigated by…
The differential, total, and transport cross sections for electrons and positrons impinging on free atoms and solid targets have been calculated in the energy range of 100–5000 eV. As an application, the mean number of the wide angle collisions suffered by the particle before slowing down to rest and the backscatterin…
Abstract Prograde evolution of illite/smectite occurring in an unusually-thick (8000 m) sequence of Mesozoic-Cenozoic sediments in the Basque-Cantabrian Basin, Spain, has been studied using XRD and TEM/AEM. The sediments, which are only slightly tilted, cover the range from smectite to illite, and the most deeply buri…
Structural parameters and their thermal changes in natural magnetite, Fe 3 O 4 , have been studied using the single-crystal X-ray diffraction method in the temperature range 126–773 K. The cell dimensions, oxygen coordinate and atomic mean square displacements (m.s.d.'s) reversibly change as a function of temperature.…
When cells of two auxotrophic mutants of Sulfolobus acidocaldarius are mixed and incubated on solid medium, they form stable genetic recombinants which can be selected, enumerated, and characterized. Any of a variety of auxotrophic markers can recombine with each other, and the phenomenon has been observed at temperat…
Haloalkane dehalogenase converts halogenated alkanes to their corresponding alcohols. The active site is buried inside the protein and lined with hydrophobic residues. The reaction proceeds via a covalent substrate-enzyme complex. This paper describes a steady-state and pre-steady-state kinetic analysis of the convers…
A finite-element formulation which derives constitutive response from crystal plasticity theory is used to examine localized deformation in fcc polycrystals. The polycrystals are (simple) idealized three-dimensional arrangements of grains, and many elements per grain. Non-uniform deformations within individual grains…
ABSTRACT Three potential photosensitizers for photodynamic therapy: tetra‐ t ‐butyl phthalocyaninato Zn(II), tetrakis‐(1,1‐dimethyl‐2‐phthalimido)ethylphthalocyaninato Zn(II), and tetrakis‐(1,1‐dimethyl‐2‐amino)ethylphthalocyaninato Zn(II), have been studied in homogeneous organic media. Dimerization constants and mon…
Abstract Kaolin has been used as an alternative cheap raw material for the synthesis of zeolite 4A. Two steps are involved in the reaction: (1) dehydroxylation of kaolin at 550–900°C to form an activated X-ray amorphous material called metakaolin; (2) hydrothermal treatment of metakaolin with aqueous alkali to form th…
The polarization resistance of composite electrodes for solid oxide fuel cells was modeled by three‐dimensional random‐resistor networks. These were generated on a computer by identifying neighbors in cubic lattices randomly occupied by electrolyte particles (ionic conductors) or electrode particles (electronic conduc…
Components of the proteinaceous cement secreted by barnacles have yet to be studied because of their insolubility. We solubilized and characterized the proteins of secondary cement, which is produced when the barnacle is detached from the substratum, in Megabalanus rosa. The cement was fractionated, according to its s…
A constant‐concentration, constant‐capacitance, macrohomogeneous porous‐electrode model is used to investigate the effects of side reactions on the charging and cycling of electrochemical double‐layer capacitors. A porous carbon capacitor with sulfuric acid electrolyte is a typical system, and corresponding physical p…
We discuss recent advances made in the theory and measurements of stresses and strains in Si-based heterostructures containing submicron- and micron-size features. Several reports on theoretical as well as experimental studies of stresses in the substrates with local oxidation of silicon structures on the surface have…
The comonomer distributions of commercial linear low density polyethylenes (LLDPE) and linear very low density polyethylenes (VLDPE) produced with traditional high activity Ziegler–Natta (Z–N) catalysts were characterized by temperature rising elution fractionation (TREF). In order to develop faster characterization m…
The dielectric behavior of a solid solution, 10 mol % lead titanate in lead magnesium niobate, vs temperature at different frequencies is measured and analyzed. The shortcomings of the Vogel–Fulcher relationship are discussed. A more reasonable new relationship: ω=ω0 exp[−(T0/Tm)p] is introduced to characterize the re…
Abstract Immersion of consecutively adsorbed polyanion/polycation multilayer films in solutions of different ionic strength causes reversible thickness changes. Swelling of the films up to 18% was observed after soaking the films in aqueous solutions of NaCl at concentrations up to 1.0 mol/1. X‐ray reflectivity clearl…
α-Al 2 O 3 :C is a highly sensitive material for thermoluminescence dosimetry (TLD), but exhibits strong light-induced fading. This light sensitivity can be exploited, however, in optically stimulated luminescence dosimetry (OSLD) when the detector is stimulated with light after exposure to radiation and luminescence…
The crystal structure of the lightly doped insulating system ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ with $x<~0.17$ has been studied in detail using neutron diffraction. It has been established that this system has two orthorhombic phases. One is the ${O}^{\ensuremath{'}}$ pha…