Materials Literature
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Functionalized tri- (A2B-type) and tetra- (A2BC-type) meso-substituted asymmetric porphyrins bearing highly reactive centers like -NH2, -OH, -CCH, -CHO in substituents at the meso positions were synthesized in good yields via the reaction of 5,15-diphenylporphyrin with corresponding functionalized organolithium reagen…
The Heusler-type Fe2VAl compound exhibits a semiconductor-like behavior with the resistivity reaching 30 \\microΩm at 2 K . Recent band-structure calculations predict that Fe2VAl is a nonmagnetic semimetal with a sharp pseudogap at the Fermi level. The existence of a pseudogap is experimentally confirmed in optical co…
Upon excitation by long wavelength UV radiation, strong room temperature luminescence is observed in a family of metal-activator-free zeolite-type materials; the luminescent output from the large cage UCSB-8Mg structure is independent of temperature from 298 K until at least 77 K.
Ethylene-vinyl alcohol copolymers (EVOH) were prepared by the conventional saponification of poly(ethylene-co-vinyl acetate) using a solution of potassium hydroxide in ethanol. An organic fungicide, consisting of a 2-benzimidazole carbamoyl (CBZ) group supported on EVOH (EVOH-CBZ), was prepared by the transesterificat…
Four different kinds of chitosans were prepared by treating crude chitin with various NaOH concentrations. The antimicrobial activities of the chitosans were tested against four species of food spoilage microorganisms (Lactobacillus plantarum, Lactobacillus fructivorans, Serratia liquefaciens, and Zygosaccharomyces ba…
The aim of this study is to determine the minimum amount of dopant that prevents the occurrence, near room temperature, of a Jahn–Teller (J–T) transition in the M-doped lithium manganese spinel of composition Li1.02MxMn1.98−xO4 with 0.00<x⩽0.06 and M = Ni2+, Co3+, Cr3+ or Ti4+. EPR spectra and magnetic susceptibility…
A simple method for the rapid electrochemical characterization of solid oxide fuel cell (SOFC) anodes is presented. Current-potential and impedance measurements have been performed at operating temperature in a simplified manner using unsintered ceramic electrodes. Results for materials with different crystal structur…
Image analysis of water drop patterns on an inclined flat polymeric insulator surface has been performed in order to find a simple mathematical function that indicates the level of hydrophobicity of the insulator surface. A simple function, given the acronym average of normalized entropies (ANE), seems to correlate we…
X-ray photoelectron spectroscopy (XPS) has been employed to investigate the protonation degree of polyaniline doped with dodecylbenzenesulfonic acid (Pani. DBSA) obtained by different synthetic methods. The protonation degree has been compared to electrical conductivity. Pani.DBSA prepared through the redoping process…
This work studies the chemical composition of copper tarnish products formed at 40, 60, and 80% relative humidity (RH) in an uncontaminated environment, for 21 days experimentation at 30°C. The experimental method used was X-ray photoelectron spectroscopy (XPS) in conjunction with -ion sputtering. The main compounds f…
A chemoinfometric method for the quantitative determination of the crystal content of indomethacin (IMC) polymorphs, based on Fourier-transform near-infrared (FT-NIR) spectroscopy, was established. A direct comparison of the data with those collected using the conventional powder X-ray diffraction method was performed…
This study investigates the thermal stability of poly(p-phenylenediamine-terephtalamide) (PPT) and poly(p-phenylenebenzobisoxazole) (PBO) fibres. Excellent behaviour of PBO is shown in comparison to that of PPT. The thermal stability (under pyrolytic or thermo-oxidative conditions) of PBO is 150 °C higher than that of…
The ability to utilize formamide as a sole nitrogen source has been found in numerous fungi. We have cloned the fmdS gene encoding a formamidase from Aspergillus nidulans and found that it belongs to a highly conserved family of proteins separate from the major amidase families. The expression of fmdS is primarily reg…
A detailed X-ray line broadening study in a ball-milled Ti sample is presented. It has been observed that ball milling leads to the formation of nanocrystalline grains and transforms partially to a fcc Ti phase after milling for 10 h. Milled samples show an inhomogeneous strain which increases with increasing milling…
Brannerite, UTi 2 O 6 , can be formed only under low oxygen pressures by dry ceramic processing techniques, but the substitution of ∼0.2 and 0.3 formula units (fu) of Ca or Gd, respectively, for U allows the stabilization of the phase in air. The Ca/Gd in brannerite provides charge compensation for some U to exist in…
Electron beam-initiated crosslinking of films prepared from a blend of low-density polyethylene (LDPE) and ethylene–vinyl acetate (EVA) containing 45% vinyl acetate, with ditrimethylol propane tetraacrylate (DTMPTA), was carried out over a range of radiation doses (20–500 kGy), concentration of DTMPTA (1–5 parts by we…
The preparation of macro–micro bifunctional porous materials has been accomplished by a well-controlled, vacuum-assisted technique. Monodisperse polystyrene latex spheres were ordered into close-packed arrays by slow sedimentation, allowing a high flux of water through the interstices between latex spheres. Zeolite LT…
Performance of a single-chamber solid oxide fuel cell was evaluated using a 0.15 mm thick Sm-doped ceria (SDC) electrolyte together with a 30 wt % SDC-Ni anode and a cathode at heating temperatures below 500°C in a flowing mixture of butane and air. A large quantity of reaction heat, which was evolved by the partial o…
A water-soluble peroxititanic complex [Ti(OH)3O2]− was prepared through the reaction between titanium metal and hydrogen peroxide at pH = 11. A solution of lead nitrate and zirconyl nitrate was added to the peroxititanic acid solution, and a stoichiometric and amorphous precipitate of a mixed oxide of lead, zirconium…
The molecular and basically isostructural oxo-alkoxides Ln5O(OPri)13 (Pri = 2-propyl) with Ln = Nd (1) and Gd (2) were synthesized by metathesis of LnCl3 and KOPri, in combination with stoichiometric hydrolysis, in 2-propanol-containing solvents. Er5O(OPri)133 was obtained as co-product to an erbium aluminium 2-propox…