Materials Literature
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A general method is proposed for the molecular level characterization of relaxation and transformation processes in polymer crystals mediated by propagation of conformational imperfections. The proposed approach combines a definition of the defect ensemble, in terms of the extent and boundary conditions of the defect…
The precipitation mechanisms and kinetics in three titanium alloys of different ß-phase stabilities - the ß-rich a α+β titanium alloy Ti-6Al-2Sn-4Zr-6Mo and the near ß-titanium alloys Ti-5Al-2Sn-2Cr-4Mo-4Zr-1Fe(ß- CEZ) and Ti-10V-2Fe-3Al - were investigated by isothermal holding in the α+β field after a ß-solution tre…
The interfacial composition and kinetics of interfacial mixing of two polymers that exhibit strong exothermic interactions, poly( N, N‘ -dimethylethylenesebacamide) (mPA) and the lithium salt of a lightly sulfonated polystyrene ionomer containing 7.4 mol % sulfonate groups (Li−SPS), were characterized by neutron refle…
A preparation is described which affords good yields of cyclic poly(oxyethylene)s with narrow chain length distributions and number-average molar masses in the range 1000–20 000 g mol–1.
Aniline is photopolmerized by illuminating a bilayer electrode composed of tris(2,2′-bipyridyl)ruthenium complex [Ru(bpy)32+] incorporated Nafion film and methylviologen pendant poly(siloxane)(PSiO-MV2+) film in aniline solution in the presence of N-phenyl-p-phenylenediamine (PPD); the role of PPD on photopolymerizati…
A general synthetic approach to rationalize the solution preparative chemistry of oxovanadium phosphates containing organic species as structural directing agents is presented. Careful attention is payed to the hydrolysis and condensation processes involving the ionic species in solution, and a simple restatement of t…
We present a simple analytical method to study the deformation behavior of a grafted melt polymer brush. We calculate the change in the free energy associated with (1) small-amplitude deformations of the free surface, (2) nonuniformity in the areal density of grafted chains, and (3) deformations of the grafting surfac…
The reaction of the bicyclic cryptand 1,4,7,10,13,16,21,24-octaazabicyclo[8.8.8]hexacosan-5,6,14,15,22,23-hexone (1) with copper(II) leads to the dinuclear complex {1,10-bis(2-aminoethyl)-1,4,7,10,13,16-hexaazacyclooctadecane-5,6,14,15-tetronato(4-)}dicopper(II) (2). 2 crystallizes in the triclinic system (space group…
An X-ray absorption study at the vanadium K edge has been performed on the LixV2O5(x= 0–0.78) system. For this, an electrochemical cell has been designed in order to allow in situ measurements. The spectra were recorded every 0.03 Li (mol V2O5)–1 using the same sample left in the X-ray beam. The study of the XANES spe…
A phase transition from Ca(OH)2 I (portlandite) to Ca(OH)2 II at high pressure and temperature has been confirmed, using in situ x-ray diffraction in a multianvil high pressure device (DIA). The structure was determined at 9.5 GPa and room temperature from data collected after heating the sample at 300°C at 7.2 GPa in…
Condensation of 4-substituted phthalonitriles with lithium 2-N,N-dimethylaminoethoxide in 2-N,N-dimethylamino-ethanol gives a non-statistical mixture of tetrasubstituted phthalocyanines at room temperature or lower while 3-substituted phthalonitriles similarly condense with lithium octan-1-olate in octan-1-ol giving 1…
The EPR single-crystal and powder spectra of mixed crystals of (3-chloroanilinium)(8)(Cd(1-x)Cu(x)Cl(6))Cl(4) are measured as a function of temperature and x and analyzed with respect to the geometry and bonding properties of the CuCl(6) polyhedra. These undergo strong distortions due to vibronic Jahn-Teller coupling,…
The adsorption of Co 2 (CO) 8 onto dehydrated NaY powder under a N 2 atmosphere and into a tetrahydrofuran slurry of NaY under a CO/H 2 atmosphere predominately yielded supported Co 4 (CO) 12 and supported Co 6 (CO) 16, respectively. The molecular cobalt−carbonyl clusters and their decarbonylated products have been st…
The increased utilization of electrochemical noise measurement in corrosion research and industrial process monitoring prompted the formation in 1991 of an ASTM Task Group within the G1 Corrosion of Metals Committee. The scope of the task group was to “develop standards that describe instruments and methods for making…
Perchloric acid was used as a catalyst for butyrylation of krill chitin. Esterification was carried out under heterogeneous conditions using a large excess of butyric anhydride at 20°C and 40°C. The effect of catalyst concentration and duration of the reaction on molecular weight and yield of butyryl chitin was invest…
Sputtering conditions are investigated in order to deposit Fe-Pt thick film magnet. Argon pressure, input power, and target-substrate distance are determined to obtain a high maximum energy product film. Under the conditions, a film of 129μm thickness with a maximum energy product of 104 kJ/m3 (13.1 MGOe) is obtained.…
The state of the art in Monte Carlo simulations of scanning electron microscope (SEM) signals is reviewed. Two Monte Carlo computer codes were written to simulate the transmitted-, backscattered-, and secondary-electron signals from targets in a scanning electron microscope. The first, MONSEL-11, is applied to semi-in…
The local structural arrangement of ions around a substitutional Cr 3+ ion in sapphire (ruby) has been studied experimentally using extended X‐ray absorption fine structure (EXAFS) in the vicinity of the Cr absorption edge. The findings are compared with an ionic model (Mott‐Littleton) computation using two sets of pa…
The solution of the cubic crystal form (a = 167.8 A) of concanavalin A complexed with the monosaccharide methyl alpha-D-glucopyranoside is described. The space group has been determined as I2(1)3 rather than I23. The use of cadmium to replace cobalt at the transition metal-ion binding site and to replace calcium at it…
The literature on the setting mechanisms of dental amalgams made from powders of silver-rich alloys of tin and/or copper has been critically reviewed. In Part 1 of the review, the microstructure and phase content of recently set amalgams are described. The composition, morphology, and location of product phases are em…