Materials Literature
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In this paper, the authors deal with the effects of inverter characteristics on iron losses in induction motors fed by pulsewidth modulation (PWM) controlled power converters. Laboratory tests based on no-load input power measurements were carried out and in order to avoid the influence of mechanical losses and rotor…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMolecular UmbrellasVaclav Janout, Marion Lanier, and Steven L. RegenView Author Information Department of Chemistry and Zettlemoyer Center for Surface Studies Lehigh University, Bethlehem, Pennsylvania 18015 Cite this: J. Am. Chem. Soc. 1996, 118, 6, 1573–1574Publicati…
Second-order hyperpolarizabilities (β), electron distribution, dipole moment, and excitation energy together with oscillator strength of stilbazolium cations have been investigated by a semiempirical calculation with PM3 parametrization of the MNDO Hamiltonian. Since stilbazoliums were found to generally have several…
We have synthesized amorphous sp 2 -bonded carbon nitrides at high pressure. A precursor composed of carbon and nitrogen, tetracyanoethylene, was compressed in a diamond anvil cell and laser heated to approximately 2000 °C. Transmission electron microscopy, electron diffraction, electron energy loss spectroscopy, and…
High tensile ductility may be achieved in metallic alloys over a limited range of strain rates at elevated temperatures when the grain size is very small (typically less than ∼10μm). These superplastic materials are often suitable for industrial forming operations. This paper considers the possibility of attaining a s…
A series of monofunctionalized triphenylene-based discotic liquid crystals were synthesized starting from 2-hydroxy-3,6,7,10,11-pentakis(pentyloxy)triphenylene. These compounds are unique in that they possess a single electron-withdrawing group (and consequently a large dipole moment) connected directly to the polyaro…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of Tetraphenyltetraacenaphthoporphyrin: A New Highly Conjugated Porphyrin System with Remarkably Red-Shifted Electronic Absorption SpectraTimothy D. Lash and Pushpa ChandrasekarView Author Information Department of Chemistry Illinois State University Normal,…
Mechanism of the oxidative dimerization of DTF (dithiafulvenes) to form TTF vinylogues (tetrathiafulvalenes) has been investigated by cyclic voltammetry at low and high scan rates for a series of substituted DTF. It involves first the formation of the cation radical which couples to form the protonated dication. This…
In this study, the authors investigated the tribological performance of diamond and diamondlike carbon (DLC) films as a function of temperature. Both films were deposited on silicon carbide (SiC) by microwave plasma chemical vapor deposition and ion-beam deposition processes. Tribological tests were performed on a rec…
The dielectric relaxation processes of a ferroelectric liquid crystal material with a first order phase transition (chiral-nematic to smectic-${\mathit{C}}^{\mathrm{*}}$) have been investigated using thin, gold coated electrode cells in the frequency range of 10 Hz to 13 MHz. The results have been reported for planar…
A new phenyltin tungstosilicate derivative, [(PhSnOH(2))(2)(gamma-SiW(10)O(36))(2)](10)(-) (1), has been prepared by reaction of phenyltin trichloride with K(8)[gamma-SiW(10)O(36)].xH(2)O. The new heteropolyanion was characterized by elemental analysis, infrared spectroscopy, multinuclear NMR, and X-ray crystallograph…
We have prepared Lactobacillus casei dihydrofolate reductase containing biosynthetically incorporated (2 S,4 S )-5-fluoroleucine ([5-F]-Leu DHFR) and have obtained its 1 H and 19 F NMR spectra at 9.4 Tesla. The 19 F spectrum of [5-F]-Leu DHFR showed 12 fairly sharp peaks (one containing two overlapped signals) for the…
Several cobalt nitrosyl porphyrins of the form (T(p/m-X)PP)Co(NO) (p/m-X = p-OCH(3) (1), p-CH(3) (2), m-CH(3) (3), p-H (4), m-OCH(3) (5), p-OCF(3) (6), p-CF(3) (7), p-CN (8)) have been synthesized in 30-85% yields by reaction of the precursor cobalt porphyrin with nitric oxide. Compounds 1-7 were also prepared by reac…
A poly(vinyl alcohol) (PVA)-degrading mixed culture that consisted of sereval microorganisms was obtained from activated sludge from a textile factory. From the culture, a component bacterial strain, BX1, that degraded PVA was isolated, and was identified as Bacillus megaterium. This strain could degrade PVA only in t…
Polycarboxylic acids have been used as cross-linking agents for cellulose to increase the wet strength of paper. In this research, we applied Fourier transform infrared (FT-IR) spectroscopy to study the kraft paper treated with poly(maleic acid) and 1,2,3,4-butanetetracarboxylic acid. FT-IR spectroscopy is used to mea…
We present experimental results of a thermoreversible morphological transition between spheres and cylinders for polystyrene- block -polyisoprene diblock copolymers (SI) in dioctyl phthalate solutions. Morphologies were characterized using small-angle X-ray scattering (SAXS), and spherical and cylindrical states were…
The preparation of a bis-copper(II) complex of an expanded porphyrin is described. A single-crystal X-ray structural analysis of this complex showed the two metal centers to lie within the mean plane of the macrocycle with a rather short interatomic distance of 2.761(1) Å. The two metal centers are formally in the +2…
Mo L 3 -edge XANES and diffuse reflectance UV−vis spectra have been recorded for structural studies of Mo−Mg binary oxides which catalyze metathesis reactions of olefins after pretreatment with H 2 at 773 K. The XANES of reference compounds revealed that the local symmetry around the Mo ion as well as the valence stat…
By extensive and systematic molecular dynamics simulations eight stable cellulose crystal structures have been identified. We organized them in a coherent scheme, which gives a clue to possible interconversions between the various structures. From this scheme it can be inferred that mercerized cellulose II could in fa…
Studied were evolution of dislocation structure, phase, and element composition of binary alloys Zr-1Nb and Zr-2.5Nb and multicomponent alloys Zr-1Nb-1.2Sn-0.4Fe and Zr-1.2Sn-0.4Fe under neutron irradiation. The investigations were carried out using cladding and pressure tubes before and after irradiation to a fluence…