Materials Literature
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We present persistence data from the 5D manifolds of europium (3+)-activated Y2O3, after excitation by ultraviolet photons. For europium concentrations below 1 at. %, the persistence is largely consistent with multiphonon relaxation. For europium concentrations at and above 1 at. %, the persistence shows evidence for…
Abstract Zein is a hydrophobic protein produced from maize. Biodegradable zein films without additional reagents were prepared using various controlled drying conditions. The zein films were transparent. Mechanical properties (tensile strength and puncture strength), gas permeability, and water vapor permeability (WVP…
Effect of oxide film passivity on low-pH stress corrosion cracking (SCC) of API 5L X-65 pipeline steel in bicarbonate solution was investigated using potentiodynamic polarization, optical microscopy, the abrading electrode technique, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), and slow…
Monomer grafting, a unique technique for polysaccharide modification, is always performed under inert (e.g., N2) atmosphere. This work is the first report related to evaluating the possibility and efficiency of the grafting of acrylonitrile (AN) onto starch in presence of oxygen. Thus, corn starch (in both granular an…
Reactive star shaped isocyanate prepolymers have been prepared by endcapping hydroxy functionalized poly(alkylene oxide)s with isophorone diisocyanate. Selective reaction conditions have been worked out to reduce the amount of chain extension and crosslinking due to reaction of both isocyanate groups of the IPDI moiet…
Polycrystalline samples of Bi2.2−xPbxSr2Co2Oy (x=0, 0.4, and 0.8) with a layered structure have been prepared using a hot pressing technique and their thermoelectric properties methodically investigated. It is found that the substitution of Pb for Bi is a fairly effective means of improving the thermoelectric properti…
Mechanical alloying (MA) has been used to synthesize Ti 3 SiC 2 powder from the elemental Ti, Si, and C powders. The MA formation conditions of Ti 3 SiC 2 were strongly affected by the ball size for the conditions used. MA using large balls (20.6 mm in diameter) enhanced the formation of Ti 3 SiC 2 , probably via an M…
Isocitrate dehydrogenase (IDH) catalyzes the reversible conversion between isocitrate and 2-oxoglutarate accompanied by decarboxylation/carboxylation and oxidoreduction of NAD(P)+ cofactor. While this enzyme has been well studied as a catabolic enzyme in the tricarboxylic acid (TCA) cycle, here we have characterized N…
ABSTRACT: Lactic acid casein‐wax‐based edible films were prepared to study the effect of carnauba and candelilla waxes. Water and oxygen permeability, thermal properties, and microstructure were determined as a function of relative humidity. Scanning electron microscopy showed a partial phase separation of wax and pro…
We describe the dopant dependence of the effective nonlinear refractive index n/sub 2eff/ in GeO/sub 2/- or F-doped core fibers theoretically and experimentally. We show that the dopant dependence of the nonlinear refractive index n/sub 2/ of F-doped bulk glass is the inverse of that of GeO/sub 2/-doped bulk glass. We…
We examined the influence of film thickness and composition on the effective Tg of compatible thin film mixtures of polystyrene (PS) and tetramethylbisphenol-A polycarbonate (TMPC) on SiOx/Si substrates using spectroscopic ellipsometry. Our measurements reveal that while the Tg of TMPC films increased with decreasing…
Acetobacter xylinum for bacterial cellulose production was cultivated in a modified airlift reactor. Better results were obtained from the modified reactor than from a conventional bubble column. After 72 h of cultivation, the final concentration of bacterial cellulose was 7.72 g/l and the productivity was 0.107 g/l p…
Abstract The assignment of the 29 Si CP/MAS-NMR spectrum of naturally-occurring sepiolite clay was re-examined using 29 Si COSY and 1 H- 29 Si HETCOR pulse sequences. Each of the three main resonances at −92.1, −94.6 and −98.4 ppm has been attributed to one of the three pairs of equivalent Si nuclei in the basal plane…
Field emission from isolated individual vertically aligned carbon nanocones (VACNCs) has been measured using a small-diameter moveable probe. The probe was scanned parallel to the sample plane to locate the VACNCs, and perpendicular to the sample plane to measure the emission turn-on electric field of each VACNC. Indi…
Liberalization of the energy market has put increasing pressure on both electricity producers and distributors for lower costs. Since maintenance is a major expense account, such companies hill be inclined to reduce maintenance budgets. At the same time, increased liability for nondelivered-energy increases the costs…
Abstract The thermally-induced dehydroxylation and transformations of the 2:1 phyllosilicate pyrophyllite have been studied using infrared spectroscopy in the frequency range 350–11000 cm −1 and the temperature range 200–1500°C. The dehydroxylation of pyrophyllite to pyrophyllite dehydroxylate occurs between 500 and 9…
To investigate the fundamental aspects of vacancy ordering in oxygen‐transporting ceramic membranes, we have performed atomic resolution analysis of individual domains in brownmillerite‐type SrCoO 3−δ . Electron energy loss spectroscopy indicates that the Co valence state in adjacent planes can be 2+ and 4+. This char…
We report the reduction of surface reflection losses in zinc germanium phosphide (ZnGeP2, or ZGP) crystals by fabricating an antireflection (AR) structure in the substrate itself using subwavelength motheye surface patterns. The motheye AR patterning works by creating a region of gradually varying effective refractive…
Synchrotron micro-XANES (X-ray absorption near-edge structure) spectroscopy (SmX) was used to measure Fe 3+ and Fe 2+ distribution among minerals in standard thin sections with an X-ray beam size of 10 ¥ 15 mm. Measurements were made at beamline X26a, National Synchrotron Light Source, Brookhaven National Lab. Samples…
Hydrogenated amorphous carbon and carbon nitride films (a-C1−xNx:H) have been synthesized from methane, acetylene, or acetylene–nitrogen precursor gases using a high density electron cyclotron resonance plasma. The deposition and etching rates, along with the film stoichiometry, density, Raman signature of the sp2 pha…