Materials Literature
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A new triterpenoid ester 3,29-di-O-(p-methoxy)benzoylmultiflora-8-ene-3 alpha,29-diol-7-one from the seeds of Momordica cochinchinensis Spreng has been isolated. Its structure was elucidated by spectroscopic evidence and confirmed by X-ray crystallography.
The first banana-shaped liquid crystal materials with photo-active azo linkages are reported. The higher temperature mesophase X1 (believed to be B6) above the B1 phase exhibited by these azo compounds shows antiferroelectric switching characteristics. The observation of banana phases in azo compounds assumes signific…
Ion transport in liquid crystals can have a negative influence on liquid crystal display performance. We introduce the importance of ion transport in industry and and the performed research. Afterwards the contribution of University of Gent will be presented in three topics: determination of concentration and mobility…
Methods for determining the workability of freshly mixed portland-cement concrete with slumps less than 51 mm (2 in.) were investigated. Four potential methods to determine the workability of concrete were proposed for evaluation and development. The methods included two moving-object methods, one free-orifice method,…
A key question arising from studies on the corrosion behavior of molybdenum has been whether the passivation of molybdenum originates from a three-dimensional oxide film or from chemisorbed oxygen. In the present paper an alternative explanation for the apparent passivation behavior of molybdenum is given based on XPS…
The use of a fingerprint texture of a cholesteric liquid crystal is demonstrated as a template to direct the formation of periodically ordered micro-size polymer walls. The morphology-property correlation of polymer-stabilized cholesteric gratings (PSCGs) was established for mesogenic and non-mesogenic reactive monome…
Abstract The photoluminescent property of a bilayer of phthalocyanine and a perylene derivative, a part of an organic photovoltaic cell, was investigated. The monolayer of the perylene derivative exhibited photoluminescence at 824 nm with lifetimes of 1.6 ns and 0.10 ns. The steady state and time-resolved photolumines…
This document presents a qualification plan that will provide the detailed background information and engineering practices to help ensure the control of repeatable base material properties and processes, which are applied to both primary and secondary structures for aircraft products using composite materials. This q…
A poly(aniline sulfate) salt was prepared by an emulsion polymerization pathway. A mixture of epoxy resin and the poly(aniline sulfate) salt sample was prepared using chloroform as solvent, and studied using both dynamic and isothermal differential scanning calorimetry (DSC). DSC analysis was performed on samples with…
The melting process of isotactic poly(propylene) (iPP) sample isothermally crystallized at 130°C for half an hour is carefully studied by means of variable-temperature FTIR spectroscopy and DSC. Based on the IR intensity changes of regularity and conformational bands vs. temperature, it is found that the helical struc…
Conventional computational fluid dynamics (CFD) methods for simulating the flow through automotive exhaust catalysts assume a monolith resistance based on one-dimensional laminar flow. This underpredicts the flow maldistribution in the monolith. Incorporation of an additional pressure loss accounting for entrance effe…
Abstract The hexadentate complex Mg[Ni(1,3-pdta)]•H2O (1,3-pdta = 1,3-propanediaminetetraacetate ion) was prepared and its structure established by X-ray crystallography. The complex salt crystallizes in the space group Pnna (# 52) of the orthorhombic crystal system with a = 13.251(2), b = 11.645(2), c = 13.818(3) Å a…
A particular class of Montgomery's self-imaging objects that we call continuously self-imaging gratings (CSIG's) is introduced. When they are illuminated by a plane wave, these objects produce a field whose intensity profile is a propagation- and wavelength-invariant biperiodic array of bright spots. The mathematical…
Abstract The low‐grade metasediments of the Cameros Basin, northern Spain, host a number of deposits of spectacular quality pyrite mineralization. These formed during regional metamorphism and the pyrite crystals exhibit a wide range of morphologies. On the basis of pyrite crystal habit, the deposits can be classified…
In nematic liquid crystal films doped with methyl-red dye or azobenzene liquid crystal, we have observed extremely efficient optically induced director axis reorientation effects, and refractive index change coefficients >> 1 cm2/W. The basic mechanisms involved are determined to be optically induced space charge fiel…
Calotropis procera (Family: Asclepiadaceae) is known to contain alkaloids, steroids and resinous substance. Different concentrations of its latex were topically applied to the 3rd stage larvae of Musca domestica. A dose of 3 ul (5% of the latex) killed and partially digested the larvae in three hours. The effect of th…
Scale and sludge deposits formed during oil production can contain elevated levels of Ra, often coprecipitated with barium sulfate (barite). The potential for sulfate-reducing bacteria to release 226Ra and Ba (a Ra analog) from oil-field barite was evaluated. The concentration of dissolved Ba increased when samples co…
This paper shows how to determine the electrode contour with the best insulation performance on the basis of an area effect and a volume effect in the breakdown field strength. Previous electric field optimization techniques have provided us only with an optimum electric field distribution, For the design of power app…
Abstract Plastomers are ethylene alpha‐olefin coplymers made from the single site metallocdene catalyst using a variety of polymerization processes. The key features are uniform intermolecular and intermolecular comonomer distribution, low extractables, comonomer dependent. meleting point, and low ashcontent. The unif…
The dielectric, piezoelectric properties, and electric-field-induced strains of the 0.2Pb(Mg1/3Nb2/3)O3–xPbZrO3–(0.8−x)PbTiO3 (x=0.30–0.50) compositions close to the morphotropic phase boundary (MPB) have been systematically investigated as a function of PbZrO3 content (x). The phase approached from the tetragonal tow…