Materials Literature
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Ti-doped MoS2 nanotubes are produced by pyrolyzing a H2S/N2 mixture over an oxidized Ti–Mo alloy powder at elevated temperatures. Partial substitution of Mo by Ti does not significantly alter the 2H–MoS2 lattice.
Abstract Free drainage in compressed‐air foams were studied experimentally and theoretically. The time evolution of liquid holdup profiles in a 0.2‐m‐high by 0.29‐m‐diameter foam column was determined at various heights by measuring sonic velocity. A new experimental technique was devised to measure the true drainage…
Equilibrium water absorption behavior of epoxy/carbon fiber composites was investigated under hygrothermal conditions. The temperature dependence of the equilibrium water uptake was quantitatively determined by assuming two distinctly different physical states of bound water and free water. The bound water was viewed…
We have investigated the spectral responsivity of porous silicon Schottky barrier photodetectors in the wavelength range 0.4-1.7 mum . The photodetectors show strong photoresponsivity in both the visible and the infrared bands, especially at 1.55 mum . The photocurrent can reach 1.8 mA at a reverse bias of 6 V under i…
With continuum-based density-functional theory, we have analyzed the liquid-crystal phases of finite-sized capped carbon nanotubes as a function of nanotube length and diameter for (i) the case when the nanotubes interact via the fully attractive van der Waals force; and (ii) when such interactions are screened out an…
We report surface-initiated thermal radical polymerization from cross-linked monolayers of azo-initiators on Au. Initial attempts to graft polymer layers from initiators attached to alkanethiol monolayers yielded polymer films with thicknesses less than 5 nm. Efficient grafting from such surfaces is not possible becau…
Electromagnetic interference (EMI) shielding on plastic mostly consists of conductive fibers in a polymer matrix. This study describes a route for the fabrication of carbon nanofiber filled poly(vinyl alcohol) (PVA) coating materials. Electrical conductivity of the coating materials ranged from 0.033 to 0.169 S/cm dep…
The magnetic properties of mixed-valent compounds of general formula Ru2Cl(mu-O2CR)4 [R = CH2-CH3 (1), C(Me)=CHEt) (2)] have been studied in the 2-300 K temperature range. This magnetic study also includes a revision of the magnetic properties of the complex Ru2Cl(mu-O2CCMePh2)4 (3). Compounds 1-3 show a linear struct…
The X-ray crystal structure of the substrate free form of Staphylococcus aureus UDP-N-acetylenolpyruvylglucosamine reductase (MurB) has been solved to 2.3 A resolution with an R-factor of 20.3% and a free R-factor of 22.3%. While the overall fold of the S. aureus enzyme is similar to that of the homologous Escherichia…
The functionalization of mesostructured and/or mesoporous MCM-41 related silicas is easily achieved by treatment under NH3 atmosphere at relatively low temperatures without structural collapse. Nitridation, which occurs through a single-step solid-state reaction, yields for the first time ordered mesoporous silicon ox…
Abstract Ternary fibrillar reinforced blends are obtained by melt‐blending of poly(ethylene terephthalate) (PET), polyamide 6 (PA‐6) and polyamide 66 (PA‐66) (20/60/20 by weight) in the presence of a catalyst, followed by cold drawing of the extruded bristles to a draw ratio of about 3.4 and additional annealing of th…
A study of carbon concentrates separated by a number of different commercial and laboratory methods from various coal-combustion fly ashes was undertaken to determine what common and unique chemical and physical properties can be expected in such concentrates. The properties were determined using a variety of physical…
A numerical hopping model is developed to investigate the temperature dependence of electrical conductivity in a distribution of localized states. An exponential energy dependence of the density-of-states (DOS) distribution (N 0/E 0)exp(E/E 0) is assumed, together with a high DOS value (1 × 1018-1 × 1021cm−3 eV−1) at…
Poly(ethylene glycol) (PEG)-grafted polyaniline (PANi) copolymers were prepared by incorporating a chlorine end-capped methoxy PEG (mPEGCl) of molecular weight of about 2000 onto the leucoemeraldine form of PANi via N-alkylation. The microstructures and compositions of the mPEG-grafted PANi (mPEG- g -PANi) copolymers…
The series of alloys (GdxTb5−x)Si4 (x=0,2.5,3,3.5,4,4.5,5) and (GdxPr5−x)Si4 (x=4,4.25,4.5) have been prepared. Their room temperature crystal structure has been established, and dc magnetization and ac magnetic susceptibility have been measured in the temperature range from 4.2 to 550 K and in dc magnetic fields up t…
Iron-dependent regulators are primary transcriptional regulators of virulence factors and iron scavenging systems that are important for infection by several bacterial pathogens. Here we present the 2.0-A crystal structure of the wild type iron-dependent regulator from Mycobacterium tuberculosis in its fully active ho…
Macroporous materials with void sizes above 200 nm have interesting optical properties in the visible part of the spectrum. Here, a strategy is presented for producing large-area thin films of macroporous titania containing interconnected and close-packed pores (see Figure). Since the pores are highly ordered they pos…
Throughout its history, the study of ferroelectricity has been closely linked with device applications. The discovery of the first ferroelectric was made during studies of Rochelle salt which had excited a great deal of interest since it showed the largest piezoelectric effect known at the time. During the ups and dow…
The grain phase has a significant influence on the extent and mechanism of attack of low‐cement castables with similar bond systems in a crucible corrosion test. The general corrosion mechanism, as determined by post mortem scanning electron microscopic examination of corroded samples and thermodynamic calculations fo…
The optical properties of lead sulfide semiconducting nanoparticulate thin films with pancake-like structures are controlled by the lowest dimension of the particles, which is a consequence of 1D quantum confinement. Optical absorption and photoluminescence spectra of the nanoparticles (see Figure) reveal that their b…