Materials Literature
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Powder X-ray diffraction data are reported for La 0.6 Sr 0.4 Co 1− y Fe y O 3 ( y =0.1, 0.25, 0.4, 0.6, 0.8, 1.0). The powders were prepared by thermal decomposition of metal-containing complex solutions. All compositions have rhombohedral unit cells. In hexagonal setting, the cell parameters are a =5.4388 Å, c =13.23…
Abstract Ca 2 P 2 S 6 und Sr 2 P 2 S 6 wurden aus Metall und einem Gemenge von rotem Phosphor und Schwefel (Molverhältnis M:P:S = 1:1:3) in 2 Korundinnentiegeln in Quarzampullen unter Vakuum (20 d 900°C) als farblose, grobkristalline Pulver, die Einkristalle enthalten, rein dargestellt. Beide sind mit der Hochtemperat…
Abstract The thermal and light‐induced spin transitions in [Fe(bpen)(NCS) 2 ] and [Fe(bpen)(NCSe) 2 ] have been investigated by means of magnetic susceptibility and Mössbauer measurements. The HS → LS transition in [Fe(bpen)(NCS) 2 ] is detected at temperatures below 120 K ( T 1/2 [when the fraction of high‐spin speci…
IR depth profiling of propane‐stabilized calcia‐alumina fibers showed that carbon deposited on the fibers during melt‐spinning induced tetrahedral coordination of aluminum atoms near the fiber surface. It is proposed that this effect increases melt surface viscosity and stabilizes calcia‐alumina fibers. Ethers, esters…
This article points to the importance of penetrating micropores through the graft wall to minimize thrombosis and to enhance endothelialization in small diameter polymer skin coated vascular grafts. Four types of spongy polyurethane-polydimethylsiloxane vascular grafts (PUG) fabricated by a spray, phase-inversion tech…
Abstract Crystallization behavior of deproteinized natural rubber at −25°C was investigated by dilatometry in connection with the effect of long-chain fatty acid groups, esterified to the rubber chain, as well as free fatty acids and their esters. The overall crystallization rate decreased after removal of the acetone…
Close correlation between the dielectric constant and the degree of preferential (111) orientation is found for Ba(Ti 0.85 Sn 0.15 )O 3 ( BTS 15 ) solid-solution thin films deposited on a Pt/Ti/SiO 2 /Si(100) substrate by pulsed laser deposition. It is shown that substrate temperature is the principal factor which det…
By changing the chemical composition of phthalocyanine molecules, the electrical properties of the ensemble in the solid state can be influenced directly. This is shown for phthalocyaninatomanganese (PcMn) as compared with purely divalent central metals and for complexes in which the ligand system has been modified by…
Summary The aggregative effect of organic matter on soil particles is conditioned by its composition and concentration and the degree to which it is associated with metal ions and oxides in the soil. We treated suspensions of kaolin or quartz substrates at pH 5 with metal (Fe or Al; c. 3 to 23 mg g −1 of substrate) or…
The inhibitive action of tetrabutyl ammonium iodide, cetyl pyridinium bromide and cetyl trimethyl ammonium bromide towards the corrosion of mild steel in sulphuric acid has been investigated by weight loss and polarisation techniques. The percentage inhibition varies with the nature and concentration of the inhibitor,…
We study concentrated solutions of ideal A-B symmetric random copolymers in non-selective good solvents by computer simulations. When the effective net A-B interaction per thermal energy in the solution (χ eff ) is larger than 2, the scattering function has a peak at a molecular weight ( N ) independent wave vector k…
A new principal mechanism underlying real-time holographic grating recording in a thin cell filled with a nematic liquid crystal doped with a dye is proposed. In the experiment a laser light interference pattern is mapped in the form of a spatial modulation of index of refraction. This is achieved by respective modula…
Possibilities of new ferroelectrics, Bi 5 Nb 3 O 15 (BIN) and Bi 5 Ta 3 O 15 (BTA), where A=Bi 5+ , B=Nb 5+ and Ta 5+ and k =1, in the general formula of mixed bismuth layer-structured oxides (MBLSO), Bi 4 A 2 k -1 B 2 k +1 O 6 k +9 ( k =1, 2, 3, 4), are discussed using ordinary fired, hot-pressed and hot-forged ceram…
This study evaluated the structure and function of a dermal substitute composed of de-epidermalized, acellular human dermis, and tested its performance as part of a composite skin graft with cultured human keratinocytes. The acellular dermis retained much of the complex structure of native dermis, as demonstrated by i…
Biological recycling of biodegradable polymers is an important option for reducing municipal solid waste. Legislation, including prohibitions on disposal of non-biodegradable waste at sea, is making development of biodegradable products more urgent. Biodegradable polymers based on cellulose, starch, protein, microbial…
A salt-based approach for the development of frequency conversion materials is presented. Salts are generally rugged materials due to their strong ionic bonding. A high degree of chemical substitution (both of anion and cation) is possible, including highly nonlinear organic ions. This flexibility is consistent with t…
A soap froth with bubbles of equal size in a cylindrical tube tends to crystallise. We exhibit, experimentally and by simulation, two sequences of transitions between different crystalline structures. Each transition is induced by a single dislocation. The two different sequences of transitions are associated with dif…
A characteristic change in the dielectric properties with A-site substitution is known in complex perovskite compounds, (Ba, Sr)(B', B")O 3 , which are expected to be applied to dielectric resonators. Recently, a phase transformation upon tilting of oxygen octahedra has been found in some of the compounds. However the…
CdS and CdSe nanoparticles were prepared in organic solvents in the presence of poly(N-vinyl-2-pyrrolidone) (PVP). PVP plays an essential role in preventing the flocculation of concentrated nanoparticles (stabilizing effect), and in controlling the particle size under the influence of the solvent used. FT-IR measureme…
Abstract Interfacial polycondensation is an important polymerization technique that encapsulates a variety of active principles. Mechanisms governing the reaction and interplay of physical and chemical rate processes need to be understood for both rational design of reaction equipment and the process control to produc…