Materials Literature
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An important feature of liquid crystal displays is surface alignment of the LCs. While mechanical rubbing has been used extensively to induce such alignment, this process also produces dust and static electricity. However, surface alignment in films of hydroxypropylcellulose has recently been achieved in situ during h…
By treating [(CO)3Re(Hpz)2(pz)] (Hpz = pyrazole) with [Cu(CH3CN)4]BF4, AgNO3, or [Au(tht)Cl] (tht = tetrahydrothiophene) in acetonitrile in the presence of Et3N, the corresponding trinuclear complexes {(CO)3Re(pz)3[M(CH3CN)]2} (1a–c) have been obtained. Treatment of complexes 1a–c with cyclohexyl isocyanide (c-C6H11NC…
A new method is proposed to correct for attenuation effects by adventitious organic contamination in quantitative XPS. The corrected intensity ratio IoX/IoY involving two different substrate peaks is determined as the slope of the plot of IX/IC1s as a function of IY/IC1s for samples covered with organic overlayers of…
Reaction parameters were optimized for the synthesis of high molecular weight ω-phenylalkyl-substituted derivatives of poly(p-xylylene) (PPX) by base-induced 1,6-dehydrohalogenation of corresponding 4-halogenomethyltoluenes. Glass transition temperatures decreased systematically with increasing alkyl spacer of the lat…
A series of amorphous and semicrystalline aromatic poly(thioethers) have been prepared by the reactions of 4,4′-thiobisbenzenethiol and activated dihalides. Azo group activated dihalide monomer was prepared by the reactions of 4-fluoronitrosobenzene with a suitable diamine. The keto and phosphine sulfide containing mo…
Thermal bulk copolymerization of styrene (monomer 1) and maleic anhydride (monomer 2) was carried out in a continuous stirred tank reactor (CSTR) with a double helical ribbon-anchor impeller. A series of experimental runs under different operating conditions (average residence time, reaction temperature, and the compo…
Although nickel(II) oxide (NiO) is a potential carcinogenic agent, it is still used in the synthesis of ceramic pigments because during their preparation at high temperature, NiO is thought to combine with other compounds, crystallizing as new phases with spinel-like structures. Unfortunately, there are no widely acce…
Abstract This paper reports the results of a numerical investigation of the diffusion and reaction of methane in the washcoat of a catalytic monolith reactor. The kinetic rate expression used is an empirical equation determined experimentally for a palladium oxide catalyst. The effect of water inhibition on the reacti…
Three-dimensional thermoluminescence (TL) spectra from ultraviolet exposed MgAl2O4 were measured over the temperature range of 300 K-600 K and the wavelength range of 300 nm-800 nm. Emission bands of all spectra at their peak temperature are centred at 520 nm and 710 nm associated with the holes captured at V2+ and Cr…
Starting from some new 2,5-disubstituted-1,3,4-oxadiazole difluorides, synthesized by cyclocondensation of dihydrazides with 4-fluorobenzoic acid, novel poly(arylene ether)s were prepared by halo displacement polymerizations with bisphenol A in the presence of potassium carbonate. Model reactions demonstrated the unsu…
Observations of the phase front and the domains during the paraelectric-ferroelectric ${\mathrm{KD}}_{2}{\mathrm{PO}}_{4}$ phase have been performed in very good thermal homogeneity conditions (thermal gradient equal to $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}{\mathrm{K}\mathrm{}\mathrm{mm}}^{\mathrm…
The isotropic–nematic transition of the tobacco mosaic virus (TMV) particles by polysaccharide is related to a high inhibitory activity against TMV infection. We study the process of the isotropic–nematic transition of the TMV particles as a function of the polysaccharide concentration by Monte Carlo simulations in th…
Electrical machines depend on ferromagnetic materials to handle useful power within a practicable compass. Flux magnification and control lies at the heart of machine efficiency. Reduction of thickness, perfection of purity and improved grain texture are some of the ways forward. Streamlined standardised loss measurin…
An investigation of dielectric relaxation at relatively low-temperature (55--225 K) of the protonic conductor ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{Nd}}_{x}{\mathrm{CeO}}_{3},$ for $x=0.05,$ has revealed a major dielectric relaxation peak, as well as an associated smaller peak, with characteristics that strongly s…
The phase transition sequence of natural gypsum (CaSO4 · 2H2O) was studied by Raman spectroscopy in the temperature range 300–550 K. The reduced peak intensity of the symmetric stretching mode around 1008 cm−1 varied anomalously during the gypsum–bassanite transition. From the spectral variations of this mode in the t…
We present a novel application of the maximum entropy (MaxEnt) method for solving the double-inverse problems of removing instrument broadening from X-ray diffraction profiles and calculating the column-length distribution of the crystallites. The MaxEnt approach is shown to have compelling advantages over the convent…
Ammonia temperature-programmed desorption (NH3-TPD) was used to study the acidities of CeO2 and Ce0.5Zr0.5O2 solid solutions. The NH3-TPD peaks of both CeO2 and Ce0.5Zr0.5O2 exist at 100–850 °C. The ratio of the lower and middle temperature peak areas to the higher temperature peak is decreased for Ce0.5Zr0.5O2 relati…
Thermally (TL) and optically stimulated luminescence (OSL) were studied in AlN-Y2O3 ceramics after irradiation with ionising radiation. The extremely high TL sensitivity (approximately 60 times the sensitivity of LiF:Mg,Tl (TLD-100)) makes AlN-Y2O3 ceramics attractive as a TLD material. However, an essential drawback…
The pseudodielectric-function spectra, ε(E)=ε1(E)+iε2(E), of amorphous (a-) selenium (Se) in the 1.2–5.2 eV photon-energy range at room temperature were measured by spectroscopic ellipsometry. The a-Se films investigated were deposited by vacuum evaporation in a base pressure of 2×10−6 Torr on Si(100) substrates at ro…
Natural thermoluminescence as well as gamma and beta induced thermoluminescence were studied in a set of micas with the general formula (K, Na) Xn AlSi3O10(OH,F)2, where X corresponds to Al3+, Mn2+, Mn3+, Fe2+, Fe3+, Mg2+, Ti4+ or Li+, depending on the mica type. These minerals are classified according to crystallogra…