Materials Literature
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${\mathrm{Er}}^{3+}$-doped ${\mathrm{ZrO}}_{2}\ensuremath{-}\mathrm{C}\mathrm{a}\mathrm{O}$ eutectic crystals with ordered microstructure have been grown by the laser floating zone method. The microstructure consists of alternating 2 \ensuremath{\mu}m thick lamellae of calcia-stabilized zirconia (CaSZ) and ${\mathrm{C…
We present an experimental study of phase-transition avalanches during the stress-induced formation of martensite in a Cu-Zn-Al alloy, with particular attention to the effect of cycling. We have analyzed statistically the amplitudes, durations, and energies of the thermal events accompanying the transition, and found…
Al/PS/c-Si photodiode structures were fabricated with a porous silicon (PS) layer of high porosity. Photosensitivity spectra, current–voltage (I–V) dependences at different temperatures, and electron beam induced current profiles were analyzed. Effects of annealing on the device characteristics were studied. The photo…
1 H NMR spectra of poly(methyl methacrylate) prepared with benzoyl peroxide in toluene at 100 °C were measured on a 750 MHz high-resolution NMR spectrometer. End groups resulting from initiation, chain transfer, and termination reactions were assigned, and the numbers of end groups per polymer molecule were estimated.…
A series of highly ordered ladder-like polysilsesquioxanes (LPS) has been synthesized via "stepwise coupling polymerization" in recent years. Among them some new kind of reactive polymers, such as polyhydrosilsesquioxane, polyvinyl (or allyl) silsesquioxane, polyethoxysilsesquioxane, etc. as parent polymers, can be fu…
We report measurements in natural horse-spleen ferritin that provide a detailed mapping of the blocking temperature, ${T}_{B},$ as a function of magnetic field over a broad range up to 20 kOe. Unlike most superparamagnetic materials where it decreases with applied field, ${T}_{B}$ increases with increasing field at sm…
The dc conductivity, dielectric constant, and electron spin resonance measurements have been performed on samples of polypyrrole, poly(N-methyl pyrrole-pyrrole), and poly(N-methyl pyrrole) having different BF4− concentrations in the temperature range 77–350 K. Different parameters evaluated from these measurements sup…
An examination has been carried out of the secondary passive film on Type 304 stainless steel in 0.5 M H 2 SO 4 . The characterization techniques used were electrochemical (potentiodynamic, potentiostatic, and film reduction experiments) and surface analytical. A bilayer model for the secondary passive film is propose…
The synthesis and spectroscopic properties of a series of soluble octaalkoxy-substituted silicon phthalocyanine monomers, (RO) 8 PcSi(OSiMe 2 tBu)L, and μ-oxo-bridged dimers, [(RO) 8 PcSi(OSiMe 2 tBu)] 2 O (R = H 17 C 8 -, H 25 C 12 -, (±)-3,7-Me 2 -C 8 H 15 -, (±)-2-Et-C 6 H 12 -; L = -OSiMe 2 tBu, -OSiMe 3, -F, -OH)…
Investigation of precipitation is performed on several near equiatomic TiNi alloys elaborated by arc melting or by powder metallurgy (combustion synthesis mode). These alloys contain various amount of impurities (oxygen, carbon , nitrogen). We show that such impurities result in both oxides (Ti4Ni2Ox, with x ≤ 1) and…
Smectic network formation using a twin liquid crystalline epoxy monomer (4-(oxiranylmethoxy)benzoic acid 1,8-octanediylbis(oxy-4,1-phenylene) ester) cross-linked with sulfanilamide was examined in real time by polarizing optical microscopy, X-ray diffraction, dynamic viscometry and differential scanning calorimetry. T…
Blazed, grazing incidence x-ray reflection gratings are an important component of modern high resolution spectrometers and related x-ray optics. These have traditionally been fabricated by diamond scribing in a ruling engine, or more recently by interferometric lithography followed by ion etching. These traditional me…
The chemical reactivity of cobalt cluster anions, Co n - ( n = 2−8), toward O 2, N 2, and CO is investigated by flow tube reactor kinetics. The reactivity is highest for the reactions with O 2 and intermediate for CO, while the clusters are nearly inert toward N 2 . Only the largest clusters studied, Co 7 - and Co 8 -…
ABSTRACT Three cultivars of long‐grain rice were milled to three degree of milling (DOM) levels. Inverse linear relationships were established between surface fat concentration (SFC) and Satake milling meter (MM1B) optical DOM measurement values, including whiteness, transparency, and DOM, for the unfractionated head…
The protein thaumatin was studied as a model macro-molecule for crystallization in microgravity-environment experiments conducted on two US Space Shuttle missions (USML-2 and LMS). In this investigation, we have evaluated and compared the quality of space- and earth-grown thaumatin crystals using X-ray diffraction ana…
The transport properties of an ionic model for liquid silica [1] at high temperatures and pressure are investigated using molecular dynamics simulations. With increasing pressure, a clear change from “strong” to “fragile” behaviour (according to Angell's classification of glass-forming liquids) is observed, albeit onl…
Although textile composites have been studied for some time, the crushing failure modes and energy absorption data have been limited. In this study, static crushing tests were conducted on 3-D carbon/epoxy and Kevlar/epoxy braided composite square tubes to investigate the failure modes and energy absorption capability…
A sol−gel process is directed toward an electrode surface via electrochemical manipulation of the solubility of trimethoxysilyl group-modified methylene blue in an aqueous environment. The process lasts for 2−3 h and results in electrode derivatization with a polysiloxane network incorporating methylene blue. Cross-li…
The damage produced in the hcp metal α-zirconium at 100 K by displacement cascades with energy in the range from 0.3 to 5keV has been investigated by molecular dynamics using a many-body interatomic potential. Comparisons have been made with the results of a recent study by Wooding et al. of α-titanium, a hcp metal wi…
A new method for the synthesis of sol−gel films of zirconia-containing nanoparticles of CdS is demonstrated. The method consists of dip-coating of the substrate from a preprepared mother solution containing zirconia tetrapropoxide, cadmium acetate, and ammonium thiocyanate and subsequent annealing of the dried film at…