Materials Literature
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Abstract The crystal structure of β -sodium acetate, NaC 2 H 3 O 2 , has been determined from X-ray powder diffraction data. Grid search and Rietveld refinement have been used to determine the structure. The crystal symmetry is orthorhombic (space group Pmn 2 1 , Z = 2) and the unit cell parameters are a = 3.4517(5) Å…
The equilibrium shape of a looped edge dislocation in a vertical smectic-$A$ film allows the determination of its line tension: in agreement with theoretical predictions, it is found to be proportional to its Burgers vector and to increase as $1/\sqrt{d}$ when the film thickness d decreases.
The SIRENS high heat flux facility at NCSU has been used to generate particulate representative of material mobilized during a hard disruption in a fusion reactor. The electrothermal (ET) plasma source in SIRENS has been found to be suitable for disruption simulation. Particulate generation occurs in both the fusion r…
The Flory-Huggins theory of flexible polymers mixtures [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, 1953)] and the Lebwohl-Lasher model of nematogens [G. Lasher, Phys. Rev. A 5, 1350 (1972); P. A. Lebwohl and G. Lasher, ibid. 6, 426 (1972)] are combined to understand the phase behav…
Novel poly(vinylsulfide)s were prepared by addition polymerization using 2,5-bis(2-thia-3-butenyl)-1,4-dithiane (TBD) with a radical initiator for an optical polymer having a high refractive index (nD) and Abbe number (v). Homopolymerization of TBD (72.9% conversion) and copolymerization with acrylonitrile or acrylate…
We have observed by polarizing microscopy a novel order transition inside the nematic phase and definitely below the clearing point of trans -4-hexylcyclohexane-1-carboxylic acid (C). The substance is known to exhibit the phase sequence Cr 32 C SmB 47 C N 96 C I (where Cr crystal, SmB smectic B, N nematic, I isotropic…
Abstract Banded urea can result in toxicity to corn ( Zea mays L.) germination and growth, due to accumulation of NH 3 and NO ‐ 2 s as a result of urea hydrolysis. Delaying urea hydrolysis through addition of acidic materials may reduce urea toxicity. Laboratory and field experiments were conducted to study phytotoxic…
An average unit cell for the Fibonacci chain has been constructed in physical space. The positions of atoms have been replaced by a statistical probability function of atomic displacements from the nearest point of the reference lattice. An analytical expression for diffraction peak intensities has been derived.
A model for simulating the voltage holding ratio in liquid crystal (LC) cells and investigating the influence of ionic impurities on device performance is proposed. Active matrix addressed liquid crystal displays (AM-LCDs) are composed of insulator materials between two electrodes, and are driven by pulse-voltage appl…
The hydrothermal reaction of (NH4)2B4O7, NaVO3, ethylenediamine, MnCl2·4H2O and H2O in the molar ratio 2.74:4:4:1:175 at 170°C for 5 days yields orange crystals of (H3NCH2CH2NH3)4[(VO)12O4[B8O17(OH)4)2 {Mn(H2O}2]·H2O(1·H2O) in 75% yield. The structure consists of a continuous contorted V12 ring, constructed from edge-…
X-ray photoelectron spectroscopy (XPS) and ion scattering spectroscopy (ISS) have been used to examine the near-surface region and outermost atomic layer of air-exposed, solvent-cleaned, LiGaO2(001) substrates, respectively, before and after room-temperature exposures to the flux produced by a novel electron stimulate…
A disordered dodecagonal quasicrystalline tantalum-rich telluride was prepared at the upper thermal stability limit of the related quasicrystalline phase by application of conventional high-temperature synthesis techniques. The structure of the disordered telluride was studied on a mesoscopic scale by means of high-re…
The problems of creating buildings with efficient lifetime has been analysed with special emphasis on their maintenance. First, the principles of a complex analysis, functional considerations, cost‐benefit ratio optimization, interrelation of sciences, mathematical simulation, etc., had been analysed which enabled the…
The isotypic title compounds are obtained in high yield from the reactions of Ba, BaO, and Ge (Si) in welded Ta containers slowly cooled from 1100 °C. The structure of Ba3GeO was determined by single-crystal X-ray diffraction (orthorhombic symmetry; Pnma (No. 62); a = 7.591(1), b = 10.728(1), c = 7.551(1) Å; Z = 4; R…
Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.
Potassium and sodium (K/Na)-modified strontium barium niobate (SBN) of the idealized formula (KxNa1—x)0.4(SryBa1—y)0.8Nb2O6(KNSBN), withx = 0.75,y = 0.60, a Curie temperature of (200 ± 2) °C, and a laser damage threshold larger than 600 MW/cm2 at 4 pps, crystallizes with a filled tungsten bronze (TB) type structure in…
Abstract Polyvinyl alcohol-containing silica gels doped with HClO4, H2SO4, or H3PO4 prepared by the sol-gel method exhibited high proton conductivities of 10−5-10−2S cm−1 at room temperature. Totally solid state electric double-layer capacitors fabricated using the gels as an electrolyte and activated carbon powder, A…
The magnetic properties of an eight-monolayer ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}(111)$ film grown epitaxially on Pt(111) have been studied by the magneto-optic Kerr effect (MOKE) and conversion electron M\"ossbauer spectroscopy. The MOKE results indicate that a saturation of the magnetization is achieved with a field…
Conventional transmission electron microscopy (TEM), coupled with energy‐dispersive X‐ray (EDX) analysis, has been used to examine the intermediate phases produced during the transformation of Ba‐Al‐alpha‐Al 2 O 3 ‐SiO 2 (cristobalite) precursors into celsian, BaAl 2 Si 2 O 8 . Analyses were conducted on samples that…
Until recently, icosahedral phase (i-phase) formation was studied primarily in Al-transition metal alloys. The Al-based i-phases generally fall into one of two classes; those believed to be based on the Pauling triacontahedron, fundamental to the Bergman 1/1 phase, and those based on the double-shell Mackay icosahedra…