Materials Literature
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Very often hydrochloric acid is employed in acidification operations aiming to dissolve the mineral matrix in petroleum wheel operations, which always require intense use of corrosion inhibitors. This work presents an evaluation of common indicators, phenolfthaleine, fluorescein, methylene blue, alizarine S and methyl…
The structural and optical properties of porous GaP have been studied by scanning electron microscopy, spectroscopic ellipsometry, and photoluminescence (PL) spectroscopy. Porous GaP layers were fabricated by anodic etching in HF:H2O:C2H5OH=1:1:2 electrolyte on n-type (100) and (111)A substrates. The morphology of the…
The aim of this study is to explore the potential of synthetic modifications of alginic acid as a method to enhance the stability of its complexes with divalent cations under physiological conditions. A fraction of algin's carboxylic acid moieties was substituted with thiol groups to different substitution degrees thr…
Magnetoelastic thin films are applied in remote interrogatable high-frequency devices. Integrated LC circuits operating at a frequency of 350 MHz are demonstrated. Due to the incorporation of the magnetic thin films, their inductance is sensitive to the applied external stress. A demonstrator was built, allowing a vis…
High temperatures creep rates in equiatomic NiTi alloys at three different stress levels and at different temperatures have been measured. It was obtained that the creep rate can be well described by the Dorn equation with n=3. The activation energy of the effective diffusion coefficient, Dc (characterizing the Herrin…
The recently discovered giant dielectric CaCu 3 Ti 4 O 12 (CCTO) has been reported to show dielectric constant value as high as 80,000 for single crystals and around 10,000 for ceramics. However the dielectric constant is also associated with high dissipation factor. In the present study, it has been observed that the…
We have determined the crystal structures of three homologous proteins from the pathogenic protozoans Leishmania donovani, Leishmania major, and Trypanosoma cruzi. We propose that these proteins represent a new subfamily within the isochorismatase superfamily (CDD classification cd004310). Their overall fold and key a…
Polarization reversals in ferroelectrics in the presence of 90° domain walls are studied using a simplified model. The rotation of a single polarization under the field applied perpendicularly to the original orientation correlates to the anisotropy of local potential energy. The polarization reversals in a ferroelect…
The microphase ordering processes for ABC linear triblock copolymers are investigated using dynamic density functional theory (DDFT). The implementation of the DDFT is verified by comparing the 2D equilibrium triblock morphologies it predicted with previous theory and experiments. Quenched from a disordered state, the…
A detailed investigation of the low-temperature plasticity of high-purity polycrystalline α-Ti (interstitial impurities O+N=0.06 at. %) is carried out. The temperature dependences of the yield strength, effective stress, rate sensitivity of the deforming stress, and activation volume are obtained in the temperature in…
The magnetic and dielectric properties of ceramic composites, in which 10 mol% antiferromagnetic LaMnO/sub 3/ was added to ferroelectric BaTiO/sub 3/, have been investigated. X-ray diffraction measurement showed that ceramics sintered in the range of 1050-1150/spl deg/C are composites containing a small amount of (La,…
Abstract Three new polyoxypregnane glycosides, marsdenosides I–K ( 1 – 3 ), were isolated from the stem of Marsdenia tenacissima. The structures were elucidated on the basis of in‐depth spectroscopic analyses, and by means of chemical evidence. Marsdenoside I ( = (3 β ,5 α ,11 α ,12 β ,14 β ,17 α ,20 R )‐3‐[(2,6‐dideo…
Abstract The aim of this work was to investigate the influence of nonionic emulsifiers on the characteristics of poly( d,l ‐lactide) (PLA) nanocapsules, which were formulated using an ultrasound probe by a modified water‐in‐oil‐in‐water (W/O/W) emulsification and solvent evaporation method. The different types of surf…
We have fabricated fully epitaxial magnetic tunnel junctions (MTJs) using a Co-based full-Heusler alloy Co/sub 2/Cr/sub 0.6/Fe/sub 0.4/Al (CCFA) thin film and an MgO tunnel barrier. The CCFA thin film for the lower ferromagnetic electrode was deposited by magnetron sputtering on an MgO-buffered MgO single-crystal subs…
Lattice Monte Carlo simulations are used to understand the role of surfactant self-assembly in the synthesis of templated mesoporous materials with ultralarge pores. Our system consists of model triblock surfactants in the presence of oil, water, and inorganic oxide. Depending on the temperature and component concentr…
Disorder in stoichiometric magnesioferrite, MgFe 2 O 4 , was determined from in situ synchrotron powder X-ray diffraction data [λ = 0.3738(4) Å] at 6, 5, and 3 GPa and temperatures up to 1430 K. The a unit-cell parameter increases linearly on heating at the three different pressures. Higher pressures cause a smaller c…
Three new homologous series of symmetrical five‐ring bent‐core compounds have been synthesized and investigated for their mesomorphic properties. The laterally unsubstituted parent compounds exhibit a metastable SmCPA phase. However, the two series of compounds containing a strongly polar cyano or nitro group at the a…
A method for preparation of Ti-doped NaAlH4 with high hydrogen capacity was developed, in which the NaH∕Al mixture was mechanically milled with a catalytic amount of KH together with metallic Ti. The addition of KH was found to result in a pronounced improvement in the dehydriding performance of the Na3AlH6∕NaH+Al ste…
A model equation for the oscillation of a pressurized gas bubble in a nonlinear incompressible elastic medium [Emelianov et al., J. Acoust. Soc. Am. 115, 581 (2004)] is extended to include effects of surface tension, viscosity, weak compressibility, and confinement by an elastic shell. The significance of this work is…
We report the results of a systematic study of the structure–mesomorphic behaviour relationships of a diverse range of light‐emitting liquid crystals, but especially nematic 2,7‐disubstituted‐9,9‐dialkylfluorenes. The dependence of the mesomorphic behaviour and transition temperatures on the nature and length of the t…