Materials Literature
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We describe the use of a near-field scanning microwave microscope to quantitatively image the dielectric permittivity and tunability of thin-film dielectric samples on a length scale of 1 micron. We demonstrate this technique with permittivity images and local hysteresis loops of a 370 nm thick barium strontium titana…
The atomic pair distribution function (PDF) of stoichiometric ${\mathrm{LaMnO}}_{3}$ has been measured. This has been fit with a structural model to extract the local Jahn-Teller distortion for an ideal ${\mathrm{Mn}}^{3+}{\mathrm{O}}_{6}$ octahedron. These results are compared to Rietveld refinements of the same data…
We investigate dendritic sidebranching during crystal growth in an undercooled melt by simulation of a phase-field model which incorporates thermal noise of microscopic origin. As a nontrivial quantitative test of this model, we first show that the simulated fluctuation spectrum of a one-dimensional interface in therm…
Human PICD was identified by homology probing the data base of expressed sequence tags with the protein sequence of Saccharomyces cerevisiae Idp3p, a peroxisomal NADP(+)-dependent isocitrate dehydrogenase. The human PICD cDNA contains a 1242-base pair open reading frame, and its deduced protein sequence is 59% identic…
The kinetics of epoxy-anhydride cure were studied by differential scanning calorimetry under isothermal and nonisothermal conditions. The data were fitted to single-step and to two-step kinetic models. In both cases the activation energies derived from nonisothermal measurements differ from the values obtained for the…
The phase transformation from kaolinite to mullite was examined with new electron diffraction data obtained using an energy‐filtering transmission electron microscope. Kaolinite was finally transformed to mullite and cristobalite through several steps of endothermic and exothermic reactions, which resulted in metakaol…
Solids produced as a result of a fast quench across a freezing or a structural transition get stuck in long-lived metastable configurations of distinct morphology, sensitively dependent on the processing history. {\it Martensites} are particularly well studied examples of nonequilibrium solid-solid transformations. Si…
We measure the photoluminescence spectra for an array of modulation doped, T-shaped quantum wires as a function of the 1d density n_e which is modulated with a surface gate. We present self-consistent electronic structure calculations for this device which show a bandgap renormalization which, when corrected for excit…
The objective of this study is to propose an intelligent material system that can perform a self-repairing operation against initial damage that might occur in GFRP laminates. Specifically, we highlight the development of a novel actuator to be used in such self-repairing operations. There has been much research on se…
High thermal stability and good mechanical properties are crucial for the wider future application of magnesium alloys. One of the most promising directions is the alloying of Mg with heavy rare earth elements such as Gd, Dy, Tb, etc. Three squeeze cast Mg–Gd binary alloys (up to 15 wt% Gd) have been investigated afte…
Dielectric relaxation and dynamic light scattering of small molecule glass-forming liquids invariably show that the fractional exponent ${\ensuremath{\beta}}_{\ensuremath{\alpha}}$ of the Kohlrausch-Williams-Watts correlation function, $\mathrm{exp}[\ensuremath{-}(t/{\ensuremath{\tau}}_{\ensuremath{\alpha}}{)}^{{\ensu…
A new direct-space method for ab initio solution of crystal structures from powder diffraction diagrams is presented. The approach consists of a combined global optimization (`Pareto optimization') of the difference between the calculated and the measured diffraction pattern and of the potential energy of the system.…
Based on semiempirical quantum-chemical calculations, the electronic band structure of β-Ga2O3 is presented and the formation and properties of oxygen vacancies are analyzed. The equilibrium geometries and formation energies of neutral and doubly ionized vacancies were calculated. Using the calculated donor level posi…
The strong dimerizing, quadruple hydrogen-bonding ureido-pyrimidone unit is used to obtain reversible polymer networks. A new synthetic route from commercially available starting materials is described. The hydrogen-bonding ureido-pyrimidone network is prepared using 3(4)-isocyanatomethyl-1-methylcyclohexyl-isocyanate…
Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a…
Spherical nickel hydroxide powders coprecipitated with the additives , , and were prepared through a spraying technique. These powders, which have a higher tapping density and a much smaller pore volume and crystalline size than conventional powders, were used as the active materials of nickel hydroxide electrodes. Th…
The performance of Cu cermets as anodes for the direct oxidation of in solid oxide fuel cells was examined. Mixtures of Cu and yttria‐stabilized zirconia (YSZ) were found to give similar performance to Ni‐YSZ cermets when was used as the fuel, but did not deactivate in dry . While Cu‐YSZ was essentially inert to metha…
The real structures of clinotobermorite, tobermorite 9 Å, and tobermorite 11 Å were determined through the application of OD approach, which allowed us to explain their peculiar disorder and polytypic features and to derive the main polytypes for each of them. The structural arrangements will be described and discusse…
In the area of crosslinked chemical supports, continuous media such as rigid macroporous polymer monoliths have certain advantages. Following an introduction to monolithic porous polymer materials, the various applications of macroporous polymer monoliths are reviewed. The Figure shows an SEM image of a monolith prepa…
Growing environmental concerns regarding the use of heavy metals in coating formulations have lead to a new coating strategy employing inherently conducting polymers (ICPs), such as polyaniline (PANI), as a key component. The principal potential advantage offered by the ICP coating technology is toleration of pinholes…