Materials Literature
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The achiral syn conformer (face-to-face) of the ethane-bridged bis(zinc porphyrin) (syn-ZnD) transforms into the corresponding chiral extended anti bis-ligated species (anti-ZnD.L2) in the presence of enantiopure ligands (L: amino acid derivatives). The mechanism of the supramolecular chirality induction is based on c…
p-Type 6H-SiC substrates were implanted with Mn + or Fe + at doses of 3 5 × 10 16 cm − 2 under conditions that avoided amorphization (substrate temperature ∼350°C). After annealing at 700°C, the magnetic properties of the samples were examined by superconducting quantum interference device magnetometry. Both the Fe-…
Ti-modified high silica zeolite with an Si/Al ratio of 1900 was found to be effective for the oxidation of propene to oxygenates such as propene oxide, in the presence of molecular oxygen at 573 K.
Abstract The crystal structure determination of tris(vanadyl)-substituted tungstoantimonate(III) K11H[(VO)3(SbW9O33)2]·27H2O reveals that the [(VO)3(SbW9O33)2]12− anion contains three exterior VO2+ groups sandwiched by two α-B [SbW9O33]9− ligands in VIV···VIV separation of 5.411(8)-5.464(8) Å and is stabilized by equa…
The mole fraction solubility of a poorly water soluble loop diuretic, furosemide, was determined in aqueous binary mixtures of ethanol, propylene glycol, and glycerol from 0% to 100% cosolvent concentrations at 25 degrees C. Solubility predictions based on the minimum number of experimental data points were performed…
Polyoxometallates act as electon relays in a photocatalytic process that involves POM/S/Mn+ (POM = polyoxometallates PW12O403−, SiW12O404− and P2Mo18O626−; S = organic substrate and Mn+ = metal ions Ag+, Cu2+, Pd2+ and Ni2+). By a suitable choice of POM and, to a lesser extent, organic substrate, selective photocataly…
The present work describes a water/oil emulsion technique for the production of microspheres by cross-linking soluble starch with epichlorohyrin, which is a very efficient divalent cross-linking agent for starch. Because they are important features for potential applications, such as pulmonary administration, special…
The degradation process of silicone rubber was investigated by leakage current monitoring in the inclined-plane method. A data acquisition system (DAS) with 12-bit, 8-channel analog/ digital (AD) converter was prepared. The maximum erosion depth was measured for use as the degradation indicator. The result suggests th…
A model to quantify the degree of mixing in pharmaceutical powder mixing operations was developed. The additive volume mixing model is based on the determination of the characteristic volume of agitation for a given blender, which is dependent on process parameters such as the formulation ingredients, the geometry of…
Spheres, rods, and wires are the most usual morphologies of semiconductor nanoparticles. Here, in contrast, cube-shaped crystals of cadmium sulfide (e.g., see Figure) are reported. The “nanocubes” are produced on self-assembled monolayers of alkanethiolates on gold, and the size of the cubes can be controlled through…
Reversible isomerization of the two axial azobenzene subunits leads to modulation of the fluorescence due to the basal tetrapyrrolic chromophore in a new hexa-coordinated phosphorus(V) porphyrin 3, illustrating its utility as a molecular photoswitch.
Tunisian untreated wastewater exhibits an average of 30 human helminth eggs per litre. After treatment, the concentration decreases to one egg per litre, or more in some cases. The percentage removal cited for wastewater processes provides no real indication of the destruction of the organisms, but merely of their tra…
Surfactant removal from MCM-41 mesostructures using ozone produced by an ozone generator is reported. Traces of water are needed to start the degradation of the mesostructure. Ozone treatment of the mesostructure powder, containing traces of water, results in a highly exothermic reaction that cannot be controlled. Sus…
We have studied the formation energy of the simplest oxygen defects in alpha-quartz, the oxygen vacancy and interstitial, by an ab initio approach based on density functional theory in the local density approximation. We have determined the formation energies and entropies and the migration paths and energies. From ou…
The modification of argon plasma-pretreated single-crystal Si(100) wafer surfaces via the UV-induced graft polymerization of poly(ethylene glycol) methacrylate (PEGMA) macromonomer (molecular weight approximately 340) for biomaterials applications was explored. The modified Si(100) surfaces were characterized by X-ray…
The study of BaTiO3 crystallization from X-ray amorphous (Ba,Ti) polymeric organic powders has been carried out by comparing samples previously heat-treated in air at 250 and 400 °C. From thermal analysis, X-ray diffraction, infrared and Raman spectroscopies, and 13C NMR spectroscopy, it has been found that the BaTiO3…
This work reports the use of polythiophene films as supporting matrix for Pt particles. The polymer film hosts were prepared using a strong acid aqueous solution, impregnated with Pt particles, and then tested for electrocatalytic properties for the oxygen reduction reaction (ORR). Cyclic voltammetry shows that the re…
One-electron reductions of [Cl(dppe)2RuCCCR2]PF6 (R = Ph, Me) and [Cl(dppe)2RuCCCCCPh 2]PF6 with Co(C5H5)2 provide radical species with the unpaired electron localized on the trisubstituted carbon atom of the cumulene moiety as shown by hydrogen atom capture and EPR spectroscopy.
There are two eutectic reactions in the Al203–rich portion of the AI2O3-Y2O3 pseudo–binary system; one is the equilibrium A1203–YAG eutectic reaction at 1826%C, and the other is the metastable A1203–YAP eutectic reaction at 1702%C. Selection of the A1203–YAG and the A1203–YAP eutectics was examined in terms of cooling…
SUBTITLE: AUTOMATION ON THE FLIGHT DECK PRODUCES SOME IMPORTANT BENEFITS BUT CAN ALSO BRING TRAINING CHALLENGES, MODE CONFUSION AND NEW POSSIBILITIES FOR ERRORS. WITH THIS IN MIND, DESIGNERS OF A MODERN ELECTRONIC CHECKLIST MADE A SPECIAL EFFORT TO ENSURE THIS AUTOMATED COCKPIT TOOL WOULD NOT INTRODUCE NEW ERROR MODES.