Materials Literature
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Tetragonal ZrO 2 particles have been added to superconducting YBa 2 Cu 3 O x (123) to improve its fracture toughness (K lC ). Reactions between the ZrO 2 and 123 prevented the ZrO 2 from providing significant toughening. A sol-gel coating of Y 2 BaCuO 5 (211) on the ZrO 2 particles minimized the deleterious reactions.…
A method to evaluate the force and particle velocity at the heated end of a rod subjected to impact loading is presented. The method is based on a characteristic impedance function determined by a set of parameters. With a given characteristic impedance function the force and particle velocity at the heated end can be…
An extensive investigation has been carried out on the compressive mechanical behaviour of type 224-carbon steel (0.18 wt % C, 1.21 wt % Mn) over the temperature range -110°C to +300°C and strain-rate 10-4 to 5000s-1, making possible the determination of the thermal sensitivity of this material. In several tests, a th…
Résumé: On sait que la contrainte d'écoulement de plusieurs métaux varie avec la vitesse de déformation de façon plus importante au-delà d'une certaine vitesse criti-que èc. Dans cet exposé une analyse des mesures antérieures sur le cuivre indique que la valeur de èc dépend fortement de la dimension…
Thirty-nine mutant tryptophan synthase alpha subunits have been purified and analyzed (in the presence of the beta 2-subunit) for their enzymatic (kcat, Km) behavior in the reactions catalyzed by the alpha 2.beta 2 complex, the fully constituted form of this enzyme. The mutant alpha subunits, obtained by in vitro rand…
Abstract A direct numerical simulation (DNS) code has been modified to investigate chemically reacting flows in a stationary, homogeneous turbulence. Single and multispecies reactions as well as complicated reaction schemes such as parallel/consecutive reactions are studied. The effects of some parameters are discusse…
Abstract Poly[(4‐ N ‐ethylene‐ N ‐ethylamino)‐α‐cyanocinnamate] was prepared by solution esterification of (4‐ N ‐ethyl‐ N ‐(2‐hydroxyethyl) amino)‐α‐Cyanocinnamic acid and by melt transesterification of ethyl (4‐ N ‐ethyl‐ N ‐(2‐hydroxyethyl) amino)‐α‐cyanocinnamate. The melt transesterification generally yielded pol…
We describe an integral approach to the rigorous solution of Maxwell's equations for diffraction from a biperiodic grating having arbitrary profile and periodicity. Emphasis is placed on the implementation of solutions and is addressed to the engineering community. The method described is amenable to mathematical conv…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTermination by reductive elimination in the polyetherification of bis(aryl chlorides) activated by carbonyl groups, with bisphenolatesV. Percec, R. S. Clough, P. L. Rinaldi, and V. E. LitmanCite this: Macromolecules 1991, 24, 21, 5889–5892Publication Date (Print):October 1,…
An investigation of the stress-strain response as a function of strain rate, spall strength, and dynamic fracture behavior of pure W, W-26Re, W-Ni-Fe and W-Ni-Fe-Co has been performed. Spall strength measurements, obtained in symmetric-impact tests, showed an increase in spall strength from 0.4 GPa for pure tungsten t…
In this paper we report the luminescence studies of octahedrally coordinated Cr3+ ions in a natural sample of kyanite (Al2O3:SiO2). The chromium ion can substitute for any one of the four nearly octahedral Al sites with the average metal-ligand distance of about 1.91 Å. Using absorption, excitation and emission spectr…
A compact electron polarimeter which operates at low scattering energies (100 eV) has been built and characterized. The polarimeter uses spin-dependent diffraction from a W(001) single crystal to measure the electron spin polarization of an incident electron beam. The design obtains reliable operation by attention to…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal analysis and Raman spectroscopic measurements on the scandium iodide-cesium iodide systemM. M. Metallinou, L. Nalbandian, G. N. Papatheodorou, W. Voigt, and H. H. EmonsCite this: Inorg. Chem. 1991, 30, 22, 4260–4264Publication Date (Print):October 1, 1991Publication…
Morton K. Schwartz, Ph.D.; Lactic Dehydrogenase: An Old Enzyme Reborn as a Cancer Marker?, American Journal of Clinical Pathology, Volume 96, Issue 4, 1 October
The crystalline character of Saudi Arabian cotton fibers was studied using a wide angle x-ray diffraction technique. The purified cotton fibers were examined in their native state and after treatment with urea or caustic soda (NaOH). Cellulosic phases in Saudi Arabian cotton were identified by measuring and indexing t…
We have used the Incomplete Factorial Approach (Carter, C. W., and Carter, C. W., Jr. (1979) J. Biol. Chem. 254, 12219-12223) in conjunction with the program Cristal (Roussel, A., Serre, L., Frey M., and Fontecilla-Camps, J. (1990) J. Crystal Growth 106, 405-409) to crystallize six different proteins. We were able to…
Abstract A convenient method for the synthesis of 11‐[(4‐cyano‐4′‐ trans ‐α‐cyanostilbene) oxy]‐ undecanyl vinyl ether ( 6 ) which is the first member of a new class of mesogenic monomers is described. The polymerization of 6 initiated with CF 3 SO 3 H/S (CH 3 ) 2 in methylene chloride at 0°C proceeds through a living…
Abstract Hydrogen migration has been followed through the thermally‐grown oxide on a Zr–2.5% Nb alloy. A secondary ion mass spectrometer, calibrated for deuterium, was used to measure the concentration as a function of depth into the film. Thin film oxide specimens, grown in steam to ∼1 μm thickness, were heated to 35…
<div class="htmlview paragraph">Pressure-loss characteristics of a variety of single- and double-substrate metal-foil and ceramic-substrate converters with tapered and truncated inlet and outlet headers were measured in room-air flow, hot-gas flow, and engine-exhaust tests. Test data in the three different media…
The title compounds have been prepared by the reactions of a potassium diselenide solution in DMF with excess selenium in the presence of tetraethyl and tetrapropyl ammonium chloride, respectively. They were characterized by X-ray crystal structure determinations. (NEt 4 + ) 2 [Se 5 2- ·1 /2 Se 6 · Se 7 ]: Space group…