Materials Literature
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Two different cubic phases in pure (Ia3d cubic space group) and mixed (Im3m cubic space group) thermotropic carboxylic acids are observed by optical microscopy. In unpolarized light, the presence of the cubic phases is identified unambiguously by the observation of facetted single crystals with highly symmetrical shap…
In the production of MDF, wet resinated fibre must be dried to its target moisture content, normally 9 to 11%, before compaction into a board by hot pressing. Fibre drying can be interpreted as an incorporated process involving gas-solid two phase-flow, inter-component transfer, and heat and mass transfer within the f…
The kinetics of photobleaching of zinc(II) tetra-t-butyltetrabenzoporphyrin 1, zinc(II) 13,17-diethyl-12,18-dimethyl-5-azadibenzo[b,g]porphyrin 2 and zinc(II) tetra-t-butylphthalocyanine 3 are studied. In methanol containing ca 0.1% pyridine, complex 1 undergoes photoaggregation, 2 is relatively photostable, while 3 u…
Abstract Novel liquid crystals (LCs) containing a trifluoromethoxy group connected to a cyclohexane mesogen or to an alkyl tail were prepared through an oxidative desulfurization-fluorination reaction of the corresponding dithiocarbonates. They were compared with LCs containing a methoxy group with respect to phase tr…
The effect of chondroitin sulfate (ChS) templates on the crystal growth of hydroxyapatite (HAp) was investigated. HAp particles and 60HAp/40ChS hybrid (in wt%) were synthesized by using a precipitation method with a calcium hydroxide suspension and phosphoric acid solutions without and with ChS, respectively. The size…
We propose a tensor description of surface anchoring of liquid crystals (LCs). The model allows one to consider both the homogeneous and inhomogeneous parts of LC anchoring and to calculate the cumulative effect of different treatments as a sum of corresponding tensors. For the planar alignment the tensor representati…
A generalized Rapini-Papoular-type anchoring energy formula [J. Phys. (Paris) Colloq. 30, C4-54 (1969)] with two coupling constants is established through a second-order spherical-harmonic expansion. Using this formula, we analyze the threshold and saturation properties of twisted nematic devices with unidirectional p…
A structural model of a one-component $\ensuremath{\sigma}$-phase crystal has been constructed by means of molecular dynamics simulation. The phonon dispersion curves and the vibrational density of states were computed for this model. The dependence of the vibrational properties on the thermodynamical parameters was i…
The ionic model is shown to give a good description of most inorganic materials, such as salts, ceramics, and minerals, regardless of the covalent or ionic character of their bonds. The virtue of the model is its ability to treat chemical bonding using simple electrostatic theory, all the quantum mechanical effects be…
A chiral photochromic polyisocyanate was incorporated into a solid polymer matrix of poly(methyl methacrylate) (PMMA), yielding an isotropic polymer film. Isomerization of the chiral photochromic azo side groups (cis-trans) triggers a reversible conformational change of the helical polyisocyanate backbone. Thus the ch…
The structure of an Al-Ni-Co decagonal quasicrystal (called the S1-type superstructure), which shows diffraction patterns with superlattice reflections, has been studied by atomic-scale observations of electron microscopy. The structure of the decagonal quasicrystal can be characterized as an ordered arrangement of tw…
The mixed-valent indium chalcogenides InTe, In 4 Se 3 , In 4 Te 3 , In 6 S 7 and In 6 Se 7 were studied together with b-In S 3 and TlInS 2 by In and Te K-edge EXAFS spectroscopy. These well-characterized crystalline solids were chosen as model systems to assess the general applicability of EXAFS for structural studies…
Abstract The reactions of trans(N)-[Co(d-pen-N,O,S)2]− with AuI or AgI in water led to the formation of novel S-bridged CoIII3M3 hexanuclear metallacycles [M3{Co(d-pen-N,O,S)2}3] (M = AuI (1), AgI (2)), in which [Co(d-pen-N,O,S)2]− units adopt a trans(O) geometry. The molecular structure of 1 was determined by X-ray c…
Alasan, the exocellular polymeric emulsifier produced by Acinetobacter radioresistens KA53 was shown to bind to the surface of Sphingomonas paucimobilis EPA505 and Acinetobacter calcoaceticus RAG-1. The presence of alasan on the surface of S. paucimobilis EPA505 and A. calcoaceticus RAG-1 caused a decrease in their ce…
The characteristics of the deformation bands (DBs), formed in cyclically deformed copper single crystals with various orientations, were summarized systematically. The formation mechanism of DBs was also explored. It was shown that the appearance of DBs seems to be a general phenomenon in cyclically deformed copper si…
Two pathways for cysteine biosynthesis are known in nature; however, it is not known which, if either, the Archaea utilize. Enzyme activities in extracts of Methanosarcina thermophila grown with combinations of cysteine and sulfide as sulfur sources indicated that this archaeon utilizes the pathway found in the Bacter…
Sol−gel processing of a multilayered film formed by the alternate adsorption of poly(diallyldimethylammonium chloride) and a synthetic silicate sheet mineral, Laponite RD, resulted in an interpenetrating composite network. Kinetic data indicate that the amount of material added due to sorption and gelation of tetraeth…
The present contribution summarizes the most recent results on the synthesis and chemical physical characterization of the new classes of porphyrazine macrocycles having annulated five- and seven-membered heterocyclic rings, i.e. tetrakis(thiadizole)porphyrazine, TTDPzH 2 , tetrakis(selenodiazole)porphyrazine, TSeDPzH…
Posiva Oy has carried out site characterisation for the final disposal of spent nuclear fuel in Finland since 1987. To meet the demanding needs to measure the hydraulic parameters in bedrock Posiva launched development of new flowmeter techniques including measuring methods and equipment in co-operation with PRG-Tec O…
Corrosion of ASTM Grade 2 Ti in alkaline peroxide environments was studied by a combination of experiments utilizing weight loss measurements, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarography. A corrosion mechanism was proposed, based on peroxide conc…