Materials Literature
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N3 center luminescence quenching by the main types of defects (A and B1) related to nitrogen impurity in natural diamond was studied by monitoring the luminescence yield and using the Raman scattering intensity as a measure of the exciting radiation intensity. The luminescence yield from the N3 centers decreases by a…
Scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) have been used to examine the structure of ordered adlayers of Ca on TiO 2 (110)-1×1 formed by metal vapor deposition. A comparison is made with structures formed by segregation of Ca from the bulk, with similar structures being found for t…
The energy exchange processes within Er3+–Yb3+-codoped silica fibers manufactured for high-power optical amplifiers are investigated through luminescent decay measurements and rate-equation modeling. The Er3+ and Yb3+ luminescence, as functions of pump power, exhibit an unquenchable Yb3+ to Er3+ cooperative energy tra…
An optical pressure cell tested at pressures up to 1000 bar is presented. The cell has been used to collect UV-Vis spectra within the temperature range 20–400°C. The cell is compact, has low volume, and atypical high-pressure window seal. To test the performance of the cell the tetrahedral-octahedral equilibria in aqu…
Protonic octatitanate fibers with novel combinational micro-mesoporous structures were prepared by using solvothermal soft chemical process in glycerine. Potassium titanate of K 2 Ti 4 O 9, which has a fibrous morphology and microstructures organized with K 2 O-rich melt on mesoscale, was used as a precursor. In the f…
Optical and infrared absorption spectra of undoped ternary silicate and CoO doped glasses were measured before and after successive gamma ray irradiation. The results obtained revealed the existence of cobalt ions mainly in tetrahedral coordination in such host glasses. The radiation-induced defects created by gamma i…
Abstract The evolution was studied of structural order/disorder phenomena across the wide stability field of the decagonal phase in the system Al—Co—Ni. Full single-crystal X-ray diffraction data sets were collected of 31 samples annealed at 900 °C. Based on reciprocal space reconstructions of the imaging-plate-scanne…
The influence of microstructure and strain rate on the mechanical behaviour of three titanium alloys having applications in aerospace, namely, commercially pure titanium (α phase), Ti–6Al–4V (α + β phases) and Ti– 15V–3Cr–3Sn–3Al (β phase) is investigated for both the parent metals and their gas tungsten arc weldments…
Dendrimers up to three generations, possessing internal PEG units within the branching framework, were synthesized by a convergent approach via the reaction of amine-based dendrons 6, 9, and 11 with 6,6-bis(4-chlorocarbonyl-2-oxabutyl)-4,8-dioxaundecane-1,11-dicarbonyl chloride. These new constructs were fully charact…
Ionic conductivities in the bismuth germanate silicate (BGSO) glasses have been investigated in the frequency range 100 Hz to 15 MHz and in the temperature range from 300 K to above the glass transition temperature T g . The frequency-dependent electrical data have been discussed in the framework of the complex impeda…
A theoretical model is proposed to describe the generation and evolution of nanoscale cracks (nanocracks) in strained nanocrystalline materials. In the framework of the model, the nanocracks are nucleated and grow along grain boundaries, changing the direction of their growth at triple junctions.
Thermoelectric elements consisting of the layered polycrystalline materials of Al‐doped ZnO and NaCo 2 O 4 were prepared using the pulse electric‐current sintering (PECS) method at 900°C for 3 min. Direct contact between the polycrystalline Al‐doped ZnO and the NaCo 2 O 4 was obtained in a single‐step process for the…
Rubrerythrin was first isolated from the anaerobic bacterium Desulfovibrio vulgaris [Protein Data Bank (PDB) entry: 1RYT].1, 2 It is a homodimeric protein and each subunit contains two different types of metal sites. One is mononuclear and located in the C-terminal domain. It is rubredoxin-like and consists of 1 metal…
Abstract Mesoporous polymer microspheres with gold (Au) nanoparticles inside their pores were prepared considering their surface functionality and porosity. The Au/polymer composite microspheres prepared were characterized by transmission electron microscope (TEM), X‐ray diffraction (XRD), and Brunauer–Emmett–Teller (…
α-brass and aluminum microhardness and deep nanoindentation data when fitted to the Taylor dislocation-hardening (TDH) model produced a straight-line behavior consistent with the model. Literature data, including copper, silver, and tungsten when also fitted to TDH model, exhibited results similar to the ones produced…
The pyruvate kinases from Genus Bacillus and a few other bacteria have an extra C-terminal sequence with a phosphoenolpyruvate binding motif composed of about 110 amino acids. To elucidate the possible structure and function of this sequence, the enzyme lacking the sequence was prepared and characterized. The N-termin…
Abstract A specific apparatus and an original batch method are developed for, respectively, nucleation and crystal growth rate measurements in a hostile environment, such as glove box. Primary nucleation and crystal growth kinetic rates for uranium oxalate are measured over a wide range of temperatures and solution co…
Abstract Preparation of nanocomposites based on ethylene‐vinyl acetate copolymer (EVA) and organoclay by melt intercalation is described in this paper. Effects of VA content, melt flow index (MFI) and maleation of EVA on melt intercalation were investigated by X‐ray diffraction. The level of intercalation into the org…
Morphological and spectroscopic studies of Sr2CeO4 blue phosphor in the form of fine particles prepared from a powdered multi-component precursor, via a combustion method, are reported. Samples were also prepared through a solid-state reaction and from a polymeric precursor for comparison. Citric acid or glycine as fu…
Chromate conversion coating (CCC) protection of untreated and acid-pretreated 7xxx Al alloys with various Cu content in aerated chloride solution as well as the polarization behavior of as-polished alloys in deaerated chloride solution were investigated using polarization techniques in conjunction with metallography,…