Materials Literature
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In this paper we compare the optical properties of nanosized silver particles dispersed in hexane solution and self-assembled in a 2D or 3D network. When the particles form monolayers organized in a hexagonal network, the plasmon peak of silver nanosized particles is shifted toward lower energy, with an increase in ba…
We have manufactured cathode ray tubes (CRTs) equipped with field emitters composed of multiwalled carbon nanotubes. The fabricated CRTs (20 mm in diameter by 74 mm in length) are of a triode type, consisting of a cathode (nanotube field emitter arrays), a grid and an anode (phosphor screen). The manufactured CRTs are…
The measurement of branching ratios, cross sections and radiative lifetimes for rare earth ions in solids is considered. The methods are applied to Tm and Ho in YLF as a test case. De-activation rates for electric dipole and magnetic dipole emission are calculated for many of the lower lying manifolds in Tm:YLF and Ho…
It is well known that the Fourier analysis of X-ray diffraction peak profiles (as implemented by Warren and Averbach) can accurately determine the areaweighted average grain size of a fine-grained sample. Less well known is the fact that this method simultaneously yields a volume-weighted average grain size. Under cer…
The anisotropy of plasticity in b.c.c. metals is decomposed into two parts. The first, a variation of the Peierls stress with slip plane and sense of slip, is intrinsic to the b.c.c. structure and is reflected in the geometry of the screw dislocation core and of the generalized stacking fault energy (γ) surface. The s…
Films of zinc oxide and related compounds are electrodeposited cathodically in aqueous zinc chloride solutions using dissolved oxygen as a precursor. The influence of the precursor concentrations, pH, and deposition temperature on the growth, composition, and properties of the films are investigated by means of in sit…
The singlet oxygen luminescence method and the photochemical methods using 1,3-diphenylisobenzofuran ( DPBF ) or bilirubin ditaurate ( BDT ) as chemical quenchers were employed to determine the single oxygen quantum yields (Φ Δ ) of different phthalocyanines and tris(2,2″-bipyridyl)ruthenium(II) dichloride in dimethyl…
Tin doped indium oxide (ITO) films are highly transparent in the visible region, exhibiting high reflectance in the infrared region, and having nearly metallic conductivity. Owing to this unusual combination of electrical and optical properties, this material is widely applied in optoelectronic devices. The associatio…
The processing, electromechanical properties, and microstructure of lead zirconate titanate (PZT) ceramics over the grain‐size range of 0.1‐10 μm were studied. Using measurements over a large temperature range (15‐600 K), the relative role of extrinsic contribution (i.e., domain‐wall motion) was deduced to be influenc…
To withstand the high intracellular pressure, the cell wall of most bacteria is stabilized by a unique cross-linked biopolymer called murein or peptidoglycan. It is made of glycan strands [poly-(GlcNAc-MurNAc)], which are linked by short peptides to form a covalently closed net. Completely surrounding the cell, the mu…
Abstract
Phase morphology and mechanical properties of the blends of Nylon 6 with scrap poly(vinyl butyral) (PVB) film and poly[styrene-block-(ethylene-co-butene)-block-styrene] (SEBS) have been investigated. Scanning electron microscopic photographs revealed that the spherical PVB particles are finely and uniformly dispersed…
Chemical behavior of lithium ions in reexpanded lithium−montmorillonites has been investigated, their hydration capacity, interlamellar availability, and thermal reactivity being examined. Two experiments have been carried out: a thermal treatment to evaluate the possible recollapse of the sample, and an ionic exchang…
The acrylic fibers containing 10.8 wt % of acrylic acid as a comonomer were treated with 5% aqueous solution of sulphates of alkali metals (sodium and potassium) and transition metals (cobalt and nickel) at 90°C for 5 min. The effect of this treatment on the chemical structure, thermal behavior and mechanical properti…
We have investigated by dynamic light scattering the dynamics of semidilute polymer solutions in a good solvent, specifically polystyrene in benzene. We have shown that, using state-of-the-art instrumentation and data analysis techniques, it is possible to identify in the spectra of relaxation times three very weak sl…
Magnetic resonance imaging often utilizes paramagnetic contrast agents (PCAs) to increase contrast between adjacent tissues. PCAs enhance the contrast by increasing the spin−lattice proton relaxation rate through processes known as inner-sphere, second-sphere, and outer-sphere mechanisms. Past studies on PCAs often de…
The phase morphology of PC/ABS blends can be significantly affected by its processing conditions. Blends prepared in a mixing chamber at different conditions show a strong influence of mixing time and temperature on its morphology. The blend morphology changes from a well-dispersed PC phase surrounded by the ABS matri…
The geometry of crambin, a protein with 46 residues, was determined by ab initio HF/4-21G geometry optimization. The results are compared with the crystal structure of the compound and with HF/4-21G φ,ψ-conformational geometry maps calculated for the model dipeptide N -acetyl- N ‘-methylalaninamide. Root-mean-square (…
Abstract
The molecular orientation at the surface of polyimide (PI) alignment layers used for liquid crystal displays has been determined using X-ray absorption spectroscopy (NEXAFS). The second moments of the orientation distribution function obtained from a detailed analysis reveal that, upon rubbing, the PI substrates devel…