Materials Literature
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We examine the effect of Coulomb interaction on the mobility and diffusion of spin packets in doped semiconductors. We find that the diffusion constant is reduced , relative to its non-interacting value, by the combined effect of Coulomb-enhanced spin susceptibility and spin Coulomb drag. In ferromagnetic semiconducto…
We review our recent results on properties of high quality B-doped homoepitaxial diamond thin films grown by chemical vapor deposition (CVD) by using trimethylboron (TMB) as a B source gas. The conventional (one-step) and the two-step growth methods were used for film preparation. The latter realized smooth surface wi…
New series of liquid crystals with a chiral chain containing two asymmetric carbon atoms in two lactate groups have been synthesized. Some compounds have a third asymmetric centre in an (S)-2-methylbutyl alkyl chain. All the new compounds have SmA, SmC* and hexatic phases. Two of the homologues with three chiral centr…
The effect of acetylene ((14)C(2)H(2)) on aerobic and anaerobic ammonia oxidation by Nitrosomonas eutropha was investigated. Ammonia monooxygenase (AMO) was inhibited and a 27 kDa polypeptide (AmoA) was labelled during aerobic ammonia oxidation. In contrast, anaerobic, NO(2)-dependent ammonia oxidation (NO(2)/N(2)O(4)…
The structures of the barite (001) and (210) cleavage surfaces were measured in contact with deionized water at 25 °C. High resolution (∼1 Å) specular X-ray reflectivity and atomic force microscopy were used to probe the step structures of the cleaved surfaces and the atomic structures of the barite−water interfaces i…
A comprehensive study of a series of four monodisperse, metal-organic pi-conjugated oligomers of varying length is reported. The oligomers are based on the aryleneethynylene architecture, and they contain a 2,2'-bipyridine-5,5'-diyl (bpy) metal binding unit. The photophysical properties of the free oligomers and their…
The objective of this research was to investigate the effects of alkaline pH conditions of dishwashing liquids on hand skin of Korean panelists after repeated exposure. A group of 30 persons with normal hands immersed their hands, for a total of 15 min a day for 4 days, into household cleansing solutions adjusted to p…
The “barrier-adhesion” principle for corrosion protection of aluminum alloys is presented. Corrosion that occurs in a coated aluminum alloy can be viewed as pertaining to one of the two following corrosion modes: corrosion that occurs at and in the vicinity of a damaged coating (damaged surface corrosion, such as that…
Raman scattering from BiI3 and SbI3 crystals has been studied at atmospheric and hydrostatic pressures up to 2 GPa. From the polarization characteristics, mode assignments were made for both crystals. The Raman shifts monotonically increased with pressure for all modes in BiI3. Although both crystals belong to the sam…
The flexoelectric behaviour of a hypertwisted chiral nematic bimesogenic liquid crystal is presented. Through detailed electro-optic measurements, with particular emphasis on the switching properties, we demonstrate remarkably high optical axis tilt angles. The material studied possessed a room temperature nematic pha…
An aromatic polyimide bearing photoreactive 4-(2-(4-oxyethylenyloxyphenyl)vinyl)pyridine side groups was synthesized and characterized. The polymer is stable up to 300°C and soluble in organic solvents, giving thin films in good quality. When exposed to UV light, it reorients favorably with an angle of 98° with respec…
New series of ferroelectric liquid crystalline materials containing methyl and methoxy lateral groups on the aromatic ring of the core unit, as well as non-substituted materials have been synthesised. All compounds exhibit a wide temperature range of the ferroelectric chiral SmC* phase. A low temperature ferroelectric…
Chloromuconate cycloisomerases of bacteria utilizing chloroaromatic compounds are known to convert 3-chloro-cis,cis-muconate to cis-dienelactone (cis-4-carboxymethylenebut-2-en-4-olide), while usual muconate cycloisomerases transform the same substrate to the bacteriotoxic protoanemonin. Formation of protoanemonin req…
Solid state diffusion bonding of Inconel 718 has been studied. Mechanical tests and metallographic examinations were used to evaluate the joint quality. The effect of bonding time, temperature, and pressure on the joint integrity was assessed. The results showed thatpartial recrystallisation occurs in joints bonded at…
The immersion test method, potentiodynamic cyclic anodic polarization, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy (XPS) techniques were used to study corrosion behavior of stainless steels (SS) and nickel-based alloys in acetic acid (CH3COOH; HAc) solutions containing bromide ions. In 50%…
The high-pressure behavior of semiconducting cadmium thiogallate CdGa2Se4 with the defect chalcopyrite structure (I4, Z=2) is studied by in situ angle-dispersive synchrotron X-ray powder diffraction and optical reflectivity measurements in a diamond anvil cell at room temperature. At 21 GPa an order–disorder phase tra…
Abstract The structure of a 2-chain helical form of sulphur with 9 atoms per unit-cell has been determined from powder synchrotron x-ray diffraction data obtained at 3 GPa and 400ºC, using a combination of global optimization, simulated annealing and Rietveld refinement techniques. Final refinement of the structure in…
This work tries to give an answer to questions persisting over a decade in literature, concerning poly(3-alkylthiophene)s: polymorphism and phase stability related to the molecular masses, their distribution, the degree of regioregularity, the length of the side chain, and its nature. In fact we have studied, by means…
Abstract Crystal-structure refinements were done on Li-bearing muscovite-2M1 crystals from microgranite and granitic pegmatite rocks in order to characterize their crystal chemistry and their relationships with muscovite and trioctahedral lithium-containing micas. In addition to the substitution mechanism [6]Li+ [6]Al…
Abstract The vibrational properties of WO 3 ceramics in the 30–300 K temperature range were probed by Raman spectroscopy. Starting with WO 3 ceramics at room temperature presenting monoclinic (V) and triclinic (VI) mixed phases, structural transitions related to decreasing temperature were observed. At low temperature…