Materials Literature
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We have performed an ab initio investigation for a series of boron compounds, BP, BAs, and BSb, and have compared their structural and electronic properties with those of c-BN. The calculations are performed using a plane-wave expansion within the local density approximation and the pseudopotential approximation. Resu…
The linear trinuclear compound Co 3 (dpa) 4 Cl 2 ( 1; dpa = di(2-pyridyl)amide anion) crystallizes from CH 2 Cl 2 solution in two forms simultaneously, namely, an orthorhombic form 1 ·CH 2 Cl 2 and a tetragonal form 1 ·2CH 2 Cl 2 . The three linearly arranged cobalt atoms in 1 are supported by four dpa ligands in a sp…
In this study, chitosan microspheres and sponges were prepared and characterized for diverse biomedical applications successfully. The chitosan microspheres were obtained with a “suspension crosslinking technique” in the size range of 30–700 μm. The stirring rate of the suspension medium and the chitosan/acetic acid r…
Dimensional stability of fiber board from lignocellulosic materials is a prime concern for efficient utility of the product. A number of methods have been used to improve the dimensional stability. These include the application of coating, oil, and wax treatments and chemical modification of lignocellulosic materials.…
We present a theoretical model of the "isostructural" γ-αphase transition in Ce which is based on quadrupolar interactions due to coupled charge density fluctuations of 4f electrons and of conduction electrons. Conduction electrons are treated in tight-binding approximation. The γ-αtransition is described as an orient…
Thin films of Pr0.7Ca 0.3MnO3, Nd-0.5Ca0.5MnO3 and Nd0.5Sr0.5MnO3 have been fabricated. by pulse laser deposition. Magnetic and electrical transport properties of these films were compared with their bulk solids. All the films grow in (101) direction on LaAlO3(100). Electrical transport measurements carried out with a…
In a miscible polymer blend the local environment of a monomer of type A will, on average, be rich in A compared to the bulk composition, φ, and similarly for B; this is a direct consequence of chain connectivity. As a result, the local dynamics of the two chains may exhibit different dependences on temperature and ov…
A systematic investigation into the influence of the wettability of spherical, nanometer-sized silica particles on the type and stability of water−toluene emulsions is described. The particles range from hydrophilic to hydrophobic depending on the extent of chemisorbed silane on their surfaces. We show that prediction…
The influence of tetraethanol-b-octadecenyl succinylamide (TOSA) on the corrosion of steel in H2S04 and HC1 solutions of divers concentrations has been studied using gravimetrical, electrochemical and polarization corrosion test methods. It has been observed that the TOSA behaves as an inhibitor of molecular active ca…
The thermomechanical performance of a shape memory alloy hybrid composite beam specimen is demonstrated and used in a preliminary validation study of a recently developed constitutive model and finite element formulation for analysis of such structures. A brief description of the thermoelastic formulation is given. A…
Changes in the local density of states (LDOS) of kinked multiwalled carbon nanotubes have been studied using scanning tunneling microscopy and spectroscopy (STM)/(STS). The measured STS spectra in the inelastically kinked region show that the LDOS is asymmetric about the Fermi level, while the spectra from regions awa…
The reduction and oxidation behaviour in alkaline solution of 3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin (L) has been studied by cyclic voltammetry. The shape of I-E curves was investigated at different terminal values of electrode potential and at different scan rates. It was shown that it is possible to obt…
High coercivities μ0iHC of 1.8 and 2.0 T, twice as high as previously reported, remanences Br of 0.63 and 0.69 T, and maximum energy products (BH)max of 70 and 89 kJ/m3 at 293 K are achieved for Nd13Dy2Fe77C8−xBx ribbons with x=0 and 2 after optimum heat treatment, respectively. The samples prepared by rapid quenching…
We report a study of polymer network morphology in planar diffraction gratings formed from polymer-stabilized cholesteric liquid crystals. Photopolymerizing a mesogenic monomer yields a regular sawtooth morphology, composed of polymer sheets running at an acute angle between thick, uniformly aligned bundles which resi…
Si/SiO 2 superlattices on oxidized silicon wafers were fabricated by successive cycles of silicon deposition and high-temperature thermal oxidation. Silicon films were deposited by low-pressure chemical vapor deposition at 580 °C. As-deposited silicon was amorphous, and it exhibited two weak photoluminescence (PL) pea…
Electro-optic polymer modulators operating at 1550 nm are demonstrated based on a nonlinear optical polymer of a phenyltetraene bridged chromophore in polycarbonate. It has a large electro-optic coefficient (r33=55 pm/V at 1550 nm), good thermal stability (90 °C), and low loss (1.7 dB/cm). A thin protective layer was…
Multibubble sonoluminescence (MBSL) spectra of water from cavitation clouds were collected in the presence of different noble gases and at different acoustic intensities. Results show that at high acoustic intensity and with xenon as a dissolved gas the emission of the OH* radical becomes indiscernible from the contin…
Highly oriented films of BaFe12O19 have been deposited onto MgO (111) substrates by pulsed laser ablation deposition. In contrast to epitaxial BaFe12O19 films grown on Al2O3 (001) substrates, these films experience an in-plane biaxial compressive stress, and do not crack or delaminate to thicknesses of at least 28 μm.…
Superconducting quantum interference device (SQUID) magnetometry and Mössbauer spectroscopy have been combined to determine the magnetic anisotropy constant K of spinel CoFe2O4 nanoparticles. The anisotropy constant is 2.23×106 erg/cm3 for CoFe2O4 nanoparticles with a mean diameter of 8.5 nm. A relaxation-time constan…
The adiabatic elastic constants ( C(ij)) of cristobalite have been evaluated successfully over the temperature range of 300-1800 K using the molecular-dynamics method with a fluctuation formula. Cristobalite shows a negative Poisson ratio over this temperature range. However, the mechanisms differ between the alpha an…