Materials Literature
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A tunable focal lens using flat electro-optical liquid-crystal cell with uniform pixel-free electrodes is developed. The lenslike gradient refractive index profile is created in the cell via the spatially distributed polymer network obtained by photopolymerization using a spatially nonuniform laser beam. The condition…
Al 2 O 3 /SiC ceramic nanocomposites were fabricated from nanocrystalline Al 2 O 3 (10 nm in diameter) and SiC (15 nm in diameter) powders, and a theoretical model of intragranular particle residual stress strengthening was investigated. The SiC nanoparticles in the Al 2 O 3 grains create a normal compressive stress a…
Abstract Silicon microreactors with Pt/Al 2 O 3 thin‐film wall catalyst were adopted for kinetic studies of CO preferential oxidation (PrOx). The activity of this catalyst was compared to that of other catalyst systems based on similar formulation. Internal and external mass‐transport and heat‐transport limitations of…
The purpose of this paper is to address the differences observed in the oxidative kinetics between flame and diesel derived soots. In particular, it has been observed that flame soot has a significantly higher activation energy for oxidation than does diesel soot. The hypothesis tested in this paper is that metals, po…
A series of compounds were designed and synthesized to examine how through-space and through-bond electron delocalization respond to solvent effects. The general strategy involves the study of "dimers" of the distyrylbenzene chromophore held in close proximity by the [2.2]paracyclophane core and a systematic dissectio…
PEG is used as a polymeric carrier for low molecular weight drugs, but limitations arise from the fact that only one or two hydroxyl residues are on each polymer. Therefore, the synthesis of dendrimeric structures, based on amino adipic acid or beta-glutamic acid, as a branching molecule, built on a PEG diol of Mw 10,…
In this paper, the fabrication, characterization, and application of unique layer-by-layer (LBL) films of dendrimers and metallic nanoparticles is reported. Silver nanoparticles (d = approximately 20 nm) are produced in solution by sodium citrate reduction and incorporated into thin films with generation 1 and 5 DAB-A…
Boron carbide (B 4 C) was synthesized from the elements at temperatures ranging from 1300° to 2100°C using the spark plasma synthesis method. Significant densification commenced at about 1500°C and was accompanied by a corresponding decrease in the defect structure of this carbide. Changes in the X‐ray diffraction pat…
A quasi-ring-type magnetoelectric (ME) laminate composite consisting of a circumferentially poled piezoelectric Pb(Zn1∕3Nb2∕3O)3-4.5at.%PbTiO3single-crystal ring and two circumferentially magnetized magnetostrictive TERFENOL-D rings was fabricated and found to have a giant ME voltage coefficient of 2.2V∕Oe, or equival…
Structural evolution of pyrochlore titanate Sm2Ti2O7 at high pressures was investigated by in situ Raman and x-ray diffraction methods. An intermediate phase was found at high pressures. The structure is a distorted pyrochlore, where anions are disordered after 40GPa while the cations are still somewhat ordered up to…
Supported nanoparticles of platinum on a wide variety of substrates, including carbon aerogel, carbon black, silica aerogel, silica, γ-alumina, and Nafion 112 film, were synthesized via a supercritical fluid route. The porous substrates and Nafion film were impregnated with an organometallic precursor, dimethyl(1,5-cy…
We have investigated change in the electronic structures of atomically controlled ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ (LSMO) thin films as a function of hole-doping levels $(x)$ in terms of in vacuo photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS) meas…
In order to better understand ferroelectricity in thin films, it is important to explore the atomic-scale structure and the spatial distribution of polarization near the interfaces. We present sub-\AA{}ngstrom-resolution electron density maps of three ultrathin ${\mathrm{PbTiO}}_{3}$ films grown epitaxially on ${\math…
The small alpha/beta protein ubiquitin has been used as a model system for experimental and computational studies on protein folding for many years. Here, we present a comprehensive phi-value analysis and characterize the structure and energetics of the transition state ensemble (TSE). Twenty-seven non-disruptive muta…
A planar near-field magnetoinductive lens operating in the microwave range is presented. The proposed device consists of two parallel planar arrays of metallic broadside coupled (BC) split-ring resonators (SRRs), or BC-SRRs. The power coming from a point-like source located in front of the lens is focused into a recei…
Following the recent discovery of large magnetoresistance at room temperature in polyfluorence sandwich devices, we have performed a comprehensive magnetoresistance study on a set of organic semiconductor sandwich devices made from different pi-conjugated polymers and small molecules. The measurements were performed a…
We have prepared and screened a library of novel functionalized polymers for development of nanoparticle drug delivery systems. The polymer backbone consisting of two ester-linked, nontoxic, biological monomers, glycerol and adipic acid, was prepared using a hydrolytic enzyme. The specificity of the chosen enzyme yiel…
Single-metal-ion-based rigid molecular building blocks (MBBs) have been utilized to design and synthesize novel metal-organic assemblies. Reaction between In(NO3)3.2H2O and 2,5-pyridinedicarboxylic acid (2,5-H2PDC) has permitted the assembly of two supramolecular isomers, a Kagomé lattice and an unprecedented M6L12 di…
Room temperature Raman scattering measurements have been carried out on well characterized samples of MgB2-xCx. The Raman line corresponding to the E2g phonon mode shows progressive hardening from 620 cm-1 in pristine MgB2 to 775 cm-1 in the sample with carbon fraction x=0.2. The corresponding line width on the other…
We have studied the internal friction and the relative change in the speed of sound of amorphous diamondlike carbon films prepared by pulsed-laser deposition from $0.3\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ to room temperature. Like most amorphous solids, the internal friction below $10\phantom{\rule{0.3em}{0ex}}\mathr…