Materials Literature
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The genes of the poly(β-hydroxybutyrate) (PHB) synthesis pathway in Ralstonia eutropha and Methylobacterium extorquens were successfully established in the yeast Saccharomyces cerevisiae. Expression of just the polyhydroxyalkanoate (PHA) synthase gene in some experiments, and all three PHB genes (i.e., the genes encod…
Evidence that brittle intergranular fracture in Al-Li alloys is associated with segregation of lithium, and maybe the formation of two-dimensional grain-boundary phases, is briefly reviewed. Particular attention is drawn to similarities between embrittlement of Al-Li alloys and segregation-induced embrittlement in oth…
The known dynamic criteria for yield of metals are generalized to the case of any stressed-strained state and an arbitrary loading duration. The criteria for uniaxial tension and simple shear are a special case. The dependences of the yield point on the strain rate are calculated using the proposed criterion and are c…
We report a method to physically separate smectite from illite in natural shale samples. This method is based upon the large contrast in the density of mixed-layer clay minerals reported in the literature. Our objective was to investigate the behavior of separate density fractions of mixedlayer smectite and illite dur…
Grain-boundary migration is demonstrated to proceed by lateral propagation of a small step in a (113), [110] symmetric Al tilt grain-boundary. In-situ high-resolution (transmission) electron microscopy (HREM) at 523K allowed the study of atomic-scale detail at video rates during the migration process. The grain-bounda…
Single crystals of the composition PbFe 1/2 Ta 1/2 O 3 are grown by the method of mass crystallization from flux. It is established that, unlike the PbFe 1/2 Ta 1/2 O 3 ceramic, the synthesized single crystals possess pronounced relaxor properties: the maximum of the dielectric constant is diffuse and its temperature,…
Ceramic samples of (1− x )SrTiO 3 - x SrMg 1/3 Nb 2/3 O 3 and (1− x )SrTiO 3 - x SrSc 1/2 Ta 1/2 O 3 were prepared, and their dielectric properties were studied at x =0.005–0.15 and 0.01–0.1, respectively, at frequencies 10 Hz–1 MHz and at temperatures 4.2–350 K. A giant dielectric relaxation was observed in the tempe…
This paper examines and discusses fiber damage in cotton, viscose, polyester, poly amide 6.6, silk, and wool in supercritical carbon dioxide at 100. 120. 140, and 160°C for I and 4 hours at a pressure of 300 bar. For comparison, experiments are conducted for 4 hours at 160°C in nitrogen and air under atmospheric condi…
A method is described for reconstructing the habits of crystals embedded in a second phase from observations of random planar sections of known orientation. We have generated simulated observations based on five assumed crystal habits and found that it is possible to reconstruct the shape from 100‐1000 planar sections…
Through layer-by-layer method [tetrakis(N-methylpyridyl)porphyrinato] cobalt (CoTMPyP) and polyoxometalyte were alternately deposited on 4-aminobenzoic acid (4-ABA) modified glassy carbon electrode. The resulting organic-inorganic hybrid films were characterized by cyclic voltammetry (CV), UV/visible absorption spectr…
Different organophilic layered silicates and a modified hydrotalcite were used as functional nanofillers for thermoplastic and thermosetting polymers. Polyamide 6 (PA6) and poly(butylene terephthalate) silicate nanocomposites were prepared by melt compounding using a twin-screw extruder. The morphology of the material…
Abstract The effects of ozone (O 3 ) gas exposure at various concentrations and treatment times on structural, mechanical and barrier properties of polyethylene and polyamide films were investigated. Changes in the structure of the films were monitored using an FT‐IR spectrometer. The results showed that O 3 treatment…
It is shown that, by using conventional VLSI design rules and device processing, a variety of two terminal and multiterminal integrated silicon light-emitting devices (Si-LEDs) can be routinely fabricated without any adaptation to the process, enabling the production of all-silicon monolithic optoelectronic systems. T…
The structure of the thermotropic cubic phases of 4′- n -alkoxy-3′-nitrobiphenyl-4-carboxylic acids (ANBC- n , where n indicates the number of carbon atoms in the alkoxy group) was studied by X-ray diffraction. For the homologues with n = 15, 16, 17, and 18, the cubic phase was of an Ia 3 d type, whereas the homologue…
Low voltage x-ray microanalysis, defined as being performed with an incident beam energy ≤5 keV, can achieve spatial resolution, laterally and in depth, of 100 nm or less, depending on the exact selection of beam energy and the composition of the target. The shallow depth of beam penetration, with the consequent short…
There has been some speculation that the C-6 position in UMP may be unusually acidic, stabilizing a carbanion that is generated at this position during OMP decarboxylation. On the basis of the rate of OH- catalyzed deuterium exchange at elevated temperatures we estimate that the pKa value for ionization at C-6 of dime…
The optical dephasing, caused by a quadratic interaction with acoustic phonons, is studied on the basis of the nonperturbative theory. The effect of a strong weakening of the elastic springs on the electronic transition is studied. It is found that, if the weakening brings the system close to the dynamical instability…
Chalcogenide glasses such as As 2 S 3 show prominent fluidity under intense subgap illumination. The feature is summarized, and the mechanism is discussed.
Proper material characterization of woven fabric reinforcement is important for accurate modeling of thermoforming. Thermoforming of commingled thermoplastic/glass fabric relies strictly on material deformation at temperatures above the matrix melting temperature. As the temperature increases, the viscosity decreases…
A coupled magnetomechanical model for the design and control of Villarieffect magnetostrictive sensors is presented. The model quantifies the magnetization changes that a magnetostrictive material undergoes when subjected to a dc excitation field and variable stresses. The magnetic behavior is characterized by conside…