Materials Literature
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The development of cellulose acetate blend membranes using a commercial grade Mycell cellulose acetate and cellulose diacetate with suitable pore structure is discussed. These membranes were characterized in terms of resistance of the membrane, pure water flux, the molecular weight cutoff, water content, pore size, an…
Based on experiments conducted, it has been found that bacterial cellulose, like spruce cellulose, is soluble in an aqueous NaOH solution with the concentration of 8.5% at a temperature of −5°C if the polymerization degree of the cellulose does not exceed 400. When 1% of urea is added to the NaOH solution, the solubil…
Within an ab-initio HF scheme, we use both Berry-phase calculations and supercell calculations in order to compute the dynamical charges for lattice dynamics and the electronic dielectric constant for KNbO_3 and BaTiO_3. Comparison with experimental data indicates that HF provides a description of the electronic prope…
The Pd catalysts were prepared by impregnating Pd(CH 3 COO) 2 in Al 2 O 3 supports. To investigate the influence of mass transfer on the catalytic performance, the catalysts and the polystyrene- block -polybutadiene- block -polystyrene thermoplastic elastomers (SBS rubber) were prepared with average pore size ranging…
Calculations on [Ag(NHCHNH)] 2 and [Ag(dmtp)(NO 3 )] 2 complexes have been performed at RHF, DFT (B3LYP), and MP2 levels. Geometry optimizations have been performed on both compounds comparing the result obtained with the different levels of theory and basis set against the available experimental X-ray data. The exist…
The synthesis, X-ray crystal structures, and ESR and magnetic properties of the anhydrous salt Na 3 [Cr(OH) 6 Mo 6 O 18 ]·6(CH 3 ) 2 SO ( CrDMSO ) containing the Anderson−Evans polyanion, of two new molecular compounds based on this polyanion ([Fe(C 5 Me 5 ) 2 ] 3 [Cr(OH) 6 Mo 6 O 18 ]·20H 2 O [ FeCr(1) ], Na[Fe(C 5 H…
Experiments and ab initio calculations have been performed to study the catalytic activity of calcium oxide and magnesium oxide toward N 2 O decomposition. The experiments were carried out in a fixed-bed quartz reactor in the temperature range 773−1223 K. The decomposition of N 2 O appeared to be a first-order reactio…
The reduction of NO by black liquor char and activated carbon was studied at atmospheric pressure in a fixed bed reactor at temperatures between 450 and 650 °C. Black liquor char has a high Na to fixed C ratio (2.7), and the Na is well dispersed within the carbon matrix. The reduction of NO by both materials was confi…
The 3,6-dideoxyhexoses can be found in the cell wall lipopolysaccharide of Gram-negative bacteria, where they have been shown to be the dominant antigenic determinants. All naturally occurring 3,6-dideoxyhexoses, with colitose as the only exception, are biosynthesized via a complex pathway that begins with CDP-d-gluco…
2,2‘-Bis(trifluoromethyl)-4,4‘,5,5‘-biphenyltetracarboxylic dianhydride (6FBPDA) was synthesized from 1-iodo-4,5-dimethyl-2-nitrobenzene via a six-step synthetic route. The dianhydride was polymerized with eight different substituted 4,4‘-diaminobiphenyls in refluxing m -cresol containing isoquinoline to afford a seri…
The reaction of aqueous solutions of Na 4 Ge 4 S 10 with various surfactant alkyltrimethylammonium bromide salts yielded new surfactant−inorganic phases containing the adamantane thiogermanate anion [Ge 4 S 10 ] 4 - . The resulting [C n H 2 n +1 N(CH 3 ) 3 ] 4 Ge 4 S 10 phases with n = 12, 14, 16, and 18 crystallize i…
Chiral oxovanadium(IV), copper(II), and palladium(II) β-diketonates show a room-temperature columnar mesophase which undergoes ferroelectric switching. All the compounds were obtained as liquid crystals at room temperature, and crystallization or melting processes were not detected by differential scanning calorimetry…
To overcome the explosions that can occur during the partial oxidation of methane, the latter exothermic reaction is coupled with an endothermic one, namely, the CO 2 reforming of CH 4 . These combined reactions have been carried out over NiO/MgO solid solution, NiO/Al 2 O 3, and NiO/SiO 2 catalysts. About 90% convers…
A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and char…
The correlation between interfacial width and adhesion, as expressed by the fracture toughness of the interface, in glassy polymers is investigated. The interfacial width is measured accurately by neutron reflectivity, and the fracture toughness of the interfaces is determined from a double cantilever beam test. Two e…
We use a one-dimensional step model to study quantitatively the growth of step bunches on Si(111) surfaces induced by a direct heating current. Parameters in the model are fixed from experimental measurements near 900 deg C under the assumption that there is local mass transport through surface diffusion and that step…
The voltage induced driving force on a migrating atom in a metallic system is discussed in the perspective of the Hellmann-Feynman force concept, local screening concepts and the linear-response approach. Since the force operator is well defined in quantum mechanics it appears to be only confusing to refer to the Hell…
We discovered a first-order phase transition between dimerized-antiferromagnetic and uniform-antiferromagnetic phases in impurity-doped spin-Peierls (SP) cuprate Cu{1-x}MgxGeO3. As impurity concentration increases, linear reduction of SP transition temperature (T{SP}) and linear increase of Neel temperature (TN) are o…
The alkali metal salts (Li +, Na +, K + ) of 3,5-di- tert -butylsemiquinone anion (3,5-DBSQ) have been prepared in the presence of three amine bases, triethylamine (TEA), tetramethylethylenediamine (TMEDA), and pentamethyldiethyltriamine (PMDTA), as well as in the absence of amine in two solvents, toluene and THF. EPR…
We present a theory for thermodynamic and equation-of-state properties of polymer solutions over the entire concentration range, and for homopolymer melts, based on analytic polymer reference interaction site model (PRISM) methods. A single polymer is modeled as either an effectively Gaussian thread, or as a Gaussian…