Materials Literature
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The aim of this work is to investigate the performance of molten carbonate fuel cells (MCFCs), with external sensible heat reformer and gas turbine/steam turbine (GT/ST) combined cycles. The analysis of these MCFC-GT/ST combined cycles has been carried out using the thermo economic modular program (TEMP) modified to a…
Samples of pure (Ca 2 FeAlO 5 ) and lightly doped (Ca 2 Fe 0.95 Al 0.95 Mg 0.05 Si 0.05 O 5 ) brownmillerite have been synthesized. Synchrotron X-ray and neutron diffraction data have been collected so that the structures can be refined using, simultaneously, both diffraction data sets and known compositional informat…
To investigate the effects of silicon, additions of 0.3, 1, and 1.5% were made to an Mg–6Al master alloy. Two types of Mg2Si particle morphology were observed, namely, squarelike and ‘Chinese script’. Silicon improved the fluidity, hardness, and microhardness, but decreased the impact toughness of Mg–6Al alloy. High…
Using the local-density approximation, and calculating the Hellmann–Feynman forces, the stability of the perovskite-like structures of CaTiO3 have been studied by applying the direct method and deriving the phonon dispersion relations. The cubic Pm3̄m phase shows dispersionless soft phonon branch spreading from R to M…
The effect of Er ion incorporation into the stoichoimetric BaTiO 3 on the dielectric properties and microstructural developement was studied. In the case of Er addition to the stoichoimetric BaTiO 3 up to 2.0 mol%, there was no change in the Curie temperature. The presence of excess Er greater than 3.0 mol% led to an…
Abstract The reciprocal lattices of a range of rare earth titanate and zirconate pyrochlores have recently been shown to exhibit an extremely characteristic diffuse intensity distribution identical in form to that characteristic of β -cristobalite implying the existence of β -cristobalite-like orientational disorder o…
Semiconducting germanium clathrates are thermoelectric materials with cage-like structures that exhibit “phonon glass, electron crystal” behavior. We report an improvement by at least a factor of 3 in the dimensionless thermoelectric figure of merit for the clathrate semiconductor Sr8Ga16Ge30 upon compression to 7 GPa…
A series of RE(Nc)(TBPP) (1−12) complexes [RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Ho, Er, Tm; Nc = 2,3-naphthalocyaninate; TBPP = meso-tetrakis(4-tert-butylphenyl)porphyrinate] and Eu[Nc(tBu)4](TClPP) [Nc(tBu)4 = tetra(tert-butyl)-2,3-naphthalocyaninate; TClPP = meso-tetrakis(4-chlorophenyl)porphyrinate] (13) have be…
We determine surface tensions σ of smectic liquid crystals from the curvature pressure of smectic films. A new technique is introduced for the comparison of surface tensions of different smectic materials. The method is based on the relation of curvatures of smectic films drawn on communicating vessels. The measuremen…
Nanocrystalline Fe3O4 and a composite system constituted by nanocrystalline Fe and Fe3O4 have been synthesized by ball-milling commercial magnetite and an equimolar mixture of iron and magnetite powders. The physical parameters governing the milling process have been strictly controlled so as to achieve the nanocrysta…
High‐purity Al 2 O 3 compacts were doped with 0–350 ppm (by weight) of MgO using a liquid immersion technique and equilibrated at temperatures between 1700° and 2000°C under hydrogen. The solubility limits of MgO in Al 2 O 3 at temperatures of 1720° and 1880°C were very low, ∼75 and 175 ppm, respectively. Variation of…
The crystal structure of pepstatin-insensitive carboxyl proteinase (PCP) from Pseudomonas sp. 101, an enzyme with no overall sequence similarity to any other proteinases of known structure, was solved using crystals soaked in sodium bromide solution and then cryocooled. A data set collected at the bromine peak absorpt…
High-pressure synchrotron X-ray powder diffraction studies of TiP 2 O 7 , ZrP 2 O 7 and ZrV 2 O 7 have been performed. The ZrV 2 O 7 structure undergoes a reversible transition at 1.38–1.58 GPa from cubic α- to pseudo-tetragonal β-ZrV 2 O 7 that displays an orthorhombic 2 × 3 × 3 supercell. At pressures above 4 GPa, Z…
Nanosize Al 2 O 3 powder was produced by pulsed wire discharge. The discharge was carried out at a peak current of ∼10 kA, the pulse length of ∼20 µs, and pulse energy of ∼80 J. Nanosize γ-Al 2 O 3 powders have been synthesized by pulsed discharge of metal wires in oxygen as an ambient gas. The powder size and its dis…
The enzymatic degradation and polymerization using an enzyme were carried out with respect to the establishment of a sustainable chemical recycling system for poly(trimethylene carbonate) [P(TMC)] which is a potentially biodegradable synthetic plastic. The enzymatic transformation of P(TMC)s having an Mn of 3000~48000…
This paper presents a one-dimensional, semi-analytical model for prediction of the wetted length supported by inclined triangular capillary grooves subject to heating from below. The model utilizes a macroscopic approach employing the concept of an apparent contact angle. Constant liquid properties are assumed and no…
A very low-field emission was achieved from aligned and opened carbon nanotube arrays. Field emission current densities of 10 microamperes per square centimeter were observed at applied fields of 0.6−1 V/μm, and current densities of 10 mA/cm 2 have been realized at applied fields as low as 2−2.7 V/μm. These fields are…
Abstract The clay particles in a kaolin deposit from Brazil were investigated by X-ray diffraction (XRD), differential thermal analysis (DTA), analytical transmission electron microscopy (ATEM), and electron paramagnetic resonance (EPR) to examine the relationships between morphological and chemical properties of the…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTCorrelation of Surface and Bulk Order in Low Surface Energy PolymersJ. Lüning, J. Stöhr, K. Y. Song, C. J. Hawker, P. Iodice, C. V. Nguyen, and D. Y. YoonView Author Information Stanford Synchrotron Radiation Laboratory, MS 69, PO B…
It is well known that the sodium smectite class of clays swells macroscopically in contact with water, whereas under normal conditions the potassium form does not. In recent work using molecular simulation methods, we have provided a quantitative explanation both for the swelling behaviour of sodium smectite clays and…