Materials Literature
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The effect of particle size and the addition of Ir on the relative sulfur sensitivity of Pt-based catalysts has been studied. Cyclopentane hydrogenolysis, a structure-sensitive reaction, was employed as a test reaction and thiophene as the poisoning molecule. Fresh and sintered monometallic Pt/Al 2 O 3 and bimetallic…
The crystal structure of monoclinic phase [ P 2 1 / c Z = 4] has been refined by the Rietveld analysis of X‐ray powder diffraction data to study the size and charge effects of dopant M n + on the unit‐cell parameters of monoclinic ZrO 2 −2 mol% MO n /2 solid solutions ( n = 4 for M = Ce; n = 3 for M = La, Nd, Sm, Y, E…
The electrochemical reduction of pyrazine (pz) on a silver electrode from a 1.0 M KBr solution has been investigated by surface enhanced Raman scattering (SERS). New bands from products of reduced pyrazine were observed at potentials more negative than -900 mV (vs. SCE). The main product is believed to be the 1,4-dihy…
A design model of sewage sludge incineration plants has been developed to examine the possibilities for energy recovery. It was evident that, without sludge drying, there was a high fuel (methane) consumptions (149-192 Nm 3 /t sludge cake at 25% concentrations), but considerable amount of electric energy is obtainable…
EXAFS and XANES spectra have been recorded at the copper K-absorption edge on hydrotalcite samples, which contain 10 mol% copper, in order to determine the local environment of the copper ions. The vanishingly small magnitude of the pre-edge peak in the XANES region of the spectra indicates a centrosymmetric coordinat…
A quasi‐planar dithiadiazafulvalene (DTDAF) with high electrondonating properties is reported. The chemical synthesis of a phenyl‐ N,N′ ‐bridged DTDAF (the Figure shows an ORTEP drawing of the DTDAF ⊕⊙ cation radical) is described together with the preparation of a charge‐transfer set by an situ trapping and investiga…
The crystal structure of the nickel(II) complex of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H 2 doda) has been determined. The ligand binds in a cis-octahedral fashion through the four nitrogen atoms and two carboxylate groups and dimerizes via an apparently symmetrical hydrogen bond from the non-bonding oxyg…
We recently designed and produced a family of new swelling-type materials that are potentially capable of self-fixation in bone. These materials are designed to absorb body fluids and swell by small amounts, which will allow the implants made from these materials to achieve self-fixation by an expansion-fit mechanism.…
FTIR spectroscopy of CO adsorbed at liquid-nitrogen temperature on zeolite K-L revealed two main IR absorption bands at 2161 and at 2150 cm -1 , respectively. These bands were assigned to the C–O-stretching mode of carbon monoxide interacting, through the carbon atom, with K + ions present in the main channel of the z…
SummaryIn order to reduce corrosion rates, zinc plated parts are usually chromated. Recently Chromates have caused increasingly environmental concern, for both allergic effects among workers touching chromated parts and toxic effects on fish, plants and bacteria.A molybdate based alternative has been developed to repl…
Our investigation is focused on the understanding of high-field phenomena in polymers. In highly insulating materials such as polyethylene, space charge has a strong influence on both the short and long term breakdown strengths. The aim of this report is to demonstrate and discuss the importance of the dynamics of vol…
A series of ruthenium–copper bimetallic catalysts on silica were prepared by the co-impregnation method. The amount of ruthenium was maintained constant at 1 wt.%. Copper loadings varied from 0.01 to 0.1 wt.%. Catalysts were characterized using surface area measurements (BET), CO adsorption followed by temperature-pro…
The topology of the microstructure and the grain growth kinetics of Nd-Fe-B magnets have been examined after sintering-time intervals between 0.5 and 19 h by metallographic analysis. In dense magnets about 80% of the grains have 5 to 7 corners. The fraction of grains with >8 corners increases with sintering-time and t…
The electronic structures of the µ 4 -chalcogenido silver(I) complexes [Ag 4 (µ-dppm) 4 (µ 4 -E)] [O 3 SCF 3 ] 2 (E = S 1, Se 2 or Te 3; dppm = Ph 2 PCH 2 PPh 2 ) have been calculated by use of the Fenske–Hall molecular orbital method. The results indicate that complexes 1–3 show similar electronic structures, with th…
Dimethyl[2,4-dioxo(1 H,3 H)pyrimido]tetrathiafulvalene (1) and dimethyl-[2-amino-4-oxo(3 H)pyrimido]tetrathiafulvalene (4) form unusual inner salts by oxidation in the presence of bases. The insoluble black-green betaines 2 and 5 react with acids to form cation radical salts. Betaine 2 in the presence of acid and bis-…
Abstract In this work, short carbon fibers were blended with poly(vinyl chloride) (PVC) plastisol forming a conductive network of the fibers in the composite. The effects of concentration and initial length of the carbon fibers on the conductivity of the network were studied. For an initial fiber length of 3 mm (L/D =…
We have identified a novel cardiac steroid, 11,19-epoxy-19-methoxytelocinobufagin, named marinosin (1), in the skin of the toad, Bufo marinus (L.) Schneider. The treatment of compound 1 with 50% CH3CN containing 0.1% trifluoroacetic acid yielded a 11 alpha-hydroxyhellebrigenin (2), which has not previously been isolat…
Organosilicon hydrides are oxidized to the corresponding silanols in high yield in a homogenous phase in the presence of a small amount of water and a catalytic amount of a rhodium complex.
Nanophase SiC/Si3N4 composite powders were synthesized by the carbothermal nitridation of SiO2. These powders have desirable characteristics of high quality with oxygen contents on the order of 1.5 to 2 wt. %, surface area of ∼ 10 m2/g, submicron α-Si3N4, low metallic impurity levels, and a homogeneous distribution of…
New linearly extended π-electron donors based on bridged dithienylethylene (DTE) end-capped with diversely substituted 1,3-dithiol-2-ylidene electron-releasing groups have been synthesized by Wittig–Horner olefination of appropriate aldehydes. Cyclic voltammetry shows that whereas the unbridged analogues are directly…