Materials Literature
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Nanopowders of yttrium aluminium garnet Y3Al5O12 (YAG) doped with neodymium ions were obtained by the co-precipitation method from the reaction of aluminium and yttrium nitrate and neodymium oxide with ammonia. After washing and drying the hydroxide precursors were calcined at 500, 700, 800 and 900 °C for 1 hour and a…
The CCA-adding enzymes [ATP(CTP):tRNA nucleotidyl transferases] catalyze synthesis of the conserved and essential CCA sequence to the tRNA 3' end. These enzymes are divided into two classes of distinct structures that differ in the overall orientation of the head to tail domains. However, the catalytic core of the two…
Abstract Polyaniline (PAni) films of different intrinsic oxidation states, including emeraldine salt, emeraldine base and leucoemeraldine base, were synthesized. Free‐standing membranes and thin film bilayers of aluminum–polyaniline were fabricated by magnetron sputter deposition of aluminum onto polyaniline films. Al…
Nanocomposite materials were prepared by incorporating multiwall carbon nanotubes (MWNTs), obtained by acetylene catalytic chemical vapor deposition (CCVD) on Co/Fe‐modified MgO, within poly(vinyl alcohol) (PVA). Before incorporation, nanotubes were oxidized to obtain better compatibilization with the polymer. It has…
Silver of 3N purity was deformed at room temperature by equal channel angular pressing (ECAP) using three passes of route A. The global and local texture were investigated by neutron diffraction and high-energy synchrotron radiation, respectively. The texture is characterized by typical simple shear components of fcc…
A calcium analog of strontioborite, namely, Ca[B 8 O 11 (OH) 4 ], is synthesized under hydrothermal conditions ( T = 270°C, P = 20 atm) within the framework of the study of the phase formation in the CaCl 2 · Rb 2 CO 3 · B 2 O 3 system. The crystal structure of the synthetic calcium borate [ a = 7.4480(5) Å, b = 8.262…
Binary diffusion-limited cluster-cluster aggregation processes are studied as a function of the relative concentration of the two species. Both, short and long time behaviors are investigated by means of three-dimensional off-lattice Brownian Dynamics simulations. At short aggregation times, the validity of the Hogg-H…
Ceramic samples of the series 1-x (Na 1/2 Bi 1/2 TiO 3 )–x (BiFeO 3 ) were made using a conventional solid state sintering technique. X-ray diffraction studies reveal their rhombohedral symmetry at room temperature. Temperature and frequency dependant dielectric measurements show that the transition temperature (Tc) s…
Dielectric properties of a novel liquid crystal with direct transition from isotropic to twist grain boundary (TGB) phase were studied. Measurements were performed over a wide range of temperature in the isotropic phase, TGBA, TGBC and SmC* phases. The Arrhenius plot of the relaxation frequency of the molecular proces…
We have developed a high-throughput x-ray characterization system, which can rapidly screen structure, composition and x-ray scintillation of combinatorial materials libraries using energy-dispersive x-ray diffraction, x-ray fluorescence, and x-ray photoluminescence. This system consists of an x-ray source, a polycapi…
By means of first-principles calculations we show that hydrogenated silicon nanowires in the ⟨001⟩ orientation can have a direct band gap with appreciable oscillator strength of the first direct transition if their surface is characterized by dimers displaying the SiH species. The breaking of some dimers (the SiH2 spe…
Abstract The microbiologically influenced corrosion (MIC) is a very dangerous process, which affects the oil industry. The activity and microorganisms' growth at the pipelines steel cause surface modifications, which can induce a more complex corrosion process. The biocide evaluation for the MIC decrease has been norm…
Quasi‐1‐D (one‐dimensional) tungsten disulfide (WS2) nanocrystal was synthesized through a two‐step hydrothermal process. Energy dispersive spectroscopy (EDS) identified that the chemical composition of the final product was WS2. The produced nanocrystal was further characterized with X‐ray diffraction (XRD), transmis…
The effect of lanthanum substitution on the structural, dielectric and piezoelectric properties of lead calcium titanate (PCT) ceramics is studied. Samples with compositional formula Pb0.76− x La x Ca0.24Ti0.98Mn0.02O3 (PLCT) (x = 0–0.08, in steps of 0.02) were prepared by the conventional dry ceramic technique. Phase…
Lead zirconate titanate (PZT) thin films were grown on a Si substrate with an epitaxial relationship by introducing yttria-stabilized zirconia (YSZ), CeO 2 , and (La,Sr)CoO 3 (LSCO) buffer layers. The buffer layers, which facilitated the growth of the epitaxial PZT thin film and controlled the residual stress, were de…
Using the state-of-the-art screened Korringa-Kohn-Rostoker Green function method we study the electronic and magnetic properties of NiMnSb and similar Heusler alloys. We show that all these compounds are half-metals, e.g. the minority-spin band is semiconducting and the Fermi level falls within this gap resulting in 1…
In the present paper, it is proposed that a sudden appearance of a burst Acoustic Emission (AE) signal under an applied dc field, during temperature decrease cycle indicates the structural phase transition (PT) from cubic to tetragonal in soft PZT ceramics (PZT-5A, 5J & 5H). In general, the PT temperature determined b…
In this study, in order to develop low-temperature-sintering ceramics for a multilayer piezoelectric actuator, Pb(Mg 1/2 W 1/2 )O 3 -Pb(Ni 1/3 Nb 2/3 )O 3 -Pb(Zr,Ti)O 3 (PMW-PNN-PZT) ceramics were fabricated using Li 2 CO 3 and CaCO 3 as sintering aids and their dielectric and piezoelectric properties were investigate…
The development of strengthened high carat Au alloys for jewellery applications is an interesting but challenging task, with significant potential for further development of new age-hardenable alloys. The paper first presents an overview on the possibilities and limitations to harden 22ct Au by conventional means, i.e…
Complete phase segregation may occur on a 10cm scale even in the absence of buoyancy due to unidirectional, large-scale rapid bulk flow. Using a hexadecane-acetone nearly density-matched liquid mixture in a 20-cm-long condenser tube with a 1cm diameter, we observed the rapid axial migration of the acetone-rich drops t…