Materials Literature
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Adsorption in porous solids at room or low temperature is one of the possible storage modes of hydrogen gas. The storage efficiency in these materials depends on their physical properties and characteristics, the most important being their adsorption capacity, porosity, density, and the endo- or exothermic character o…
For the first time combined X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) experiments were carried out to probe the short- and long-range order in lanthanum-modified PbTiO 3 ceramic materials (Pb 1 - x La x TiO 3 ) for x ranging from 0 to 30 atom % of La. XRD results show that a tetragonal structure…
Abstract Based on finite element formulations for the strain gradient theory of microstructures, a convergence criterion for the C 0–1 patch test is introduced, and a new approach to devise strain gradient finite elements that can pass the C 0–1 patch test is proposed. The displacement functions of several plane trian…
We have studied the nanostructural and nanochemical changes occurring in pure ceria (CeO2) and CeO2–zirconia (ZrO2) catalysts during reduction. The reduction is carried out in an environmental transmission electron microscope in dry H2 at 2 Torr up to 800°C. We use in-situ electron-energy-loss spectroscopy to follow c…
The origin of the improvement of the ferroelectric and piezoelectric properties of KNbO 3 ceramics by the addition of small amounts of La and Fe has been investigated. The La/Fe-codoped KNbO 3 ceramics formed a single (K 1- x La x )(Nb 1- x Fe x )O 3 solid solution, and their unit-cell volume decreased significantly w…
AIM: To determine the effect of the aqueous extract of Mondia whitei (Periplocaceae) roots on testosterone production and fertility of male rats. METHODS: Adult male Wistar rats were used. In the acute study, 20 rats were randomly divided into 5 groups of 4 animals each. Four treated groups were administered orally a…
Abstract Electrospinning is a process by which ultrafine fibers which have diameters in the range of tens of nanometers to less than ten of micrometers can be produced. This process utilizes expulsion of charges as a means to very thin fiber formation. In this short report, the effects of some of the influencing solut…
Abstract Product mixtures of epoxidized fatty compounds can be analyzed by using 1 H NMR. Conversion of double bonds and selectivities to different products can easily be calculated. Moreover, if diunsaturated substrates are used in epoxidation reactions, yields to mono‐ and diepoxidized products can be determined. Th…
In order to clarify the thermodynamic relations of various phases in NaNbO 3 , the enthalpies of formation for the cubic ( Pm3m ), tetragonal ( P4/mbm ), orthorhombic ( Ccmm , Pnmm , Pbma ) and rhombohedral ( R3c ) phases in NaNbO 3 were calculated using a plane-wave pseudopotential method. The NaNbO 3 phase with a lo…
[structure: see text] A new type of glycocluster based on polyhedral oligosilsesquioxanes (POSS) has been efficiently prepared from unprotected mannoside and lactoside employing a convergent approach of thiol-radical addition reaction. The versatility of this approach was demonstrated by functionalization of mannoside…
Summary Significant progress has been made toward developing a quantitative understanding of the inhibitor/rock interaction. In this study, four common oil field inhibitors (three phosphonates and one polyacrylate) are compared using carbonate-rich formation material. In addition to calcite (CaCO3) in the reservoir ro…
Plastic deformation affects the hysteretic magnetic properties of steels because it changes the dislocation density, which affects domain-wall movement and pinning, and also because it places the specimen under residual strain. An earlier paper proposed a model for computing hysteresis loops on the basis of the effect…
A 820 micron thick single crystal diamond layer epitaxially grown on a single crystal diamond seed (high pressure, high temperature grown synthetic) by microwave plasma chemical vapor deposition with added nitrogen is characterized by an array of analytical techniques before and after annealing the material at high pr…
Feeling the heat: Surface-initiated atom transfer radical polymerization was used to modify a film of aligned carbon nanotubes with poly(N-isopropylacrylamide) (see TEM image). A distinct temperature responsiveness is found for both the macroscopic (wettability) and the microscopic (the diameter and rigidity of a sing…
Addition of BF(3).OEt(2) to ethereal solutions of the Ni(II) beta-diketiminates [Me(2)NN]Ni(R)(2,4-lutidine) (R = Et (1), Pr (2)) allows the isolation of the neutral beta-H agostic monoalkyls [Me(2)NN]Ni(R) (R = Et (3), Pr (4)). X-ray studies of primary alkyls 3 and 4a reveal acute Ni-C(alpha)-C(beta) angles with shor…
We study the classical 120 degree and related orbital models. These are the classical limits of quantum models which describe the interactions among orbitals of transition-metal compounds. We demonstrate that at low temperatures these models exhibit a long-range order which arises via an “order by disorder” mechanism.…
This paper first reviews three internationally standardized core loss measurement methods: the Epstein frame, toroids, and single sheet testers. A comparison of the Epstein frame and toroid test results is presented for annealed and unannealed steel. Two methods are used to predict core losses under nonsinusoidal supp…
In this paper, mechanical properties of the fibers extracted from the areca fruit are determined and compared with the other known natural fiber coir. Further these Areca fibers were chemically treated and the effect of this treatment on fiber strength is studied. Areca fiber composite laminates were prepared using Ph…
Abstract Transition metal oxide compounds with perovskite‐type structure (AMX 3‐δ ) show besides attractive physical properties, such as high temperature superconduction or thermoelectricity, often excellent catalytic properties for various redox reactions. The catalytic reactivity is strongly dependent on composition…
The engineered domain configuration was induced into potassium niobate (KNbO 3 ) crystals, and the piezoelectric properties were investigated as a function of domain size. First, single-domain treatment was investigated, and a combination of chemical etching and 2-step electric poling treatment was effective. Using th…