Group theory and polarisation algebra
Approche unifiee a l'algebre de la polarisation en utilisant les groupes unitaires speciaux SU(2) et SU(4) et leurs homomorphismes respectifs et les groupes orthogonaux reels O + (3) et O + (6)
Materials Literature
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Invited Review Article
Since 1935, various mechanisms have been suggested for the formation of subsurface lesions and, in particular, the surface layer covering enamel lesions. The relatively intact mineral-rich and porous surface layer is most likely caused by kinetic events. The suggested mineral-rich outer layer in sound enamel, the orga…
Organization of Extracellularly Mineralized Tissues: A Comparative Study of Biological Crystal Growt
Biological mineralization processes are extremely diverse and, to date, it is an act of faith rather than an established principle that organisms utilize common mechanisms for forming crystals. A systematic analysis of the structural organization, as far as possible at the molecular level, of five different extracellu…
Diatoms as Indicators of Organic Pollution
Abstract There is given a list of 323 taxa of freshwater diatoms occurring in waters of Central Europe. Each taxon is characterized by 10 balls of saprobic valence, the indicative weight of species (I i ) and by the individual saprobic index (S i ) indicating its position on a conventional scale of saprobity. Diatoms…
Principles of Materials Science and Engineering
This book attempts to provide basic knowledge about the structure, properties, and processing of engineering materials and their applications. The first chapter gives an introduction to materials science and engineering and briefly describes the main types of engineering materials. Chapters 2 to 4 cover basic material…
Highly conducting, soluble, and environmentally-stable poly(3-alkylthiophenes)
Homopolymers and copolymers of 3-alkylthiophenes incorporating alkyl groups equal to or greater than butyl in size can be handled in solution and form highly conducting, environmentally-stable compositions on doping.
Soluble conducting polythiophenes
Tractable polythiophenes which are soluble in ordinary organic solvents at ambient temperatures are prepared by the electrochemical polymerization of thiophenes having a long alkyl chain.
Electrically conducting polymers: a review of the electropolymerization reaction, of the effects of chemical structure on polymer film properties, and of applications towards technology
The electrochemical oxidation of aromatic heterocyclic compounds thiophene, pyrrole, and indole and benzenoid and nonbenzenoid polycyclic hydrocarbons azulene, fluorene, and pyrene yield electrically conducting polymers with conductivities of 10 −5 –10 S/cm. The presence of substituents affects the electrical conducti…
Copper(II) ion-exchanged ZSM-5 zeolites as highly active catalysts for direct and continuous decomposition of nitrogen monoxide
ZSM-5 zeolites containing Cu2+ ions showed unusually high and steady state activity for the catalytic decomposition of nitrogen monoxide; for example, the degrees of conversions of NO, and of conversion into N2 and O2 were 97, 85, and 70%, respectively, at 823 K with a contact time of 10.0 g s cm–3 over 73% exchanged…
Multichannel Landauer formula for thermoelectric transport with application to thermopower near the mobility edge
Various thermoelectric linear transport coefficients are defined and calculated for two reservoirs connected with ideal multichannel leads and a segment of an arbitrary disordered system. The reservoirs have different temperatures and chemical potentials. All of the inelastic scattering (and, thus, the dissipation) is…
Thin-Film Optical Filters
Introduction. Basic theory. Antireflection coating. Neutral mirrors and beam splitters. Multilayer high-reflectance coatings. Edge filters. Band-pass filters. Tilted coatings. Production methods and thin-film materials. Factors affecting layer and coating properties. Layer uniformity and thickness monitoring. Specific…
EDIBLE FILMS AND COATINGS: A REVIEW
A technical overview discussed the rationale for using edible films for preventing moisture loss from films while allowing permeability of oxygen and carbon dioxide to prevent anaerobic bacterial growth within the encased food. Detailed attention also is given to the characteristics of the types of edible films, cover…
Amorphous carbon
The properties of various types of amorphous carbon and hydrogenated amorphous carbon are reviewed with particular emphasis on the effect of atomic structure on the electronic structure. It is shown how the proportion of sp3 and sp2 sites not only defines the short-range order but also a substantial medium-range order…
Polyaniline, a novel conducting polymer. Morphology and chemistry of its oxidation and reduction in aqueous electrolytes
The emeraldine salt form of polyaniline, conducting in the metallic regime, can be synthesized electrochemically as a film exhibiting a well defined fibrillar morphology closely resembling that of polyacetylene. Cyclic voltammograms of chemically synthesized and electrochemically synthesized polyaniline are essentiall…
Orientational optical nonlinearity of liquid crystals
The orientational optical nonlinearity of the mesophases of liquid crystals (LCs) is attracting ever more attention, owing to the high values of the constants characterizing it, owing to the many interesting specific features that LCs introduce even into traditional nonlinear optical effects, and owing to the potentia…
Vegard's rule and volumes of formation for impurity ions
Calculated volumes of formation for substitutional impurities in alkali halides are shown to be approximately consistent with the empirical rule that for miscible crystals the average volume per ion pair scales linearly between the two single-component extremes (Vegard's rule). The small deviations found from the rule…
Phase winding and flow alignment in freely suspended films of smectic-Cliquid crystals
We present the first experimental study of shear-flow--induced behavior in a two-dimensional anisotropic fluid: circular, freely suspended films of smectic-C liquid crystals. Depending on the topology of the in-plane director configuration, we observe either a phase winding state, where \ensuremath{\Phi}, the phase de…
Latent-image generation by deposition of monodisperse silver clusters
Silver cluster ions (${\mathrm{Ag}}_{1}$${\mathrm{}}^{+}$, ${\mathrm{Ag}}_{3}$${\mathrm{}}^{+}$, ${\mathrm{Ag}}_{4}$${\mathrm{}}^{+}$, ${\mathrm{Ag}}_{5}$${\mathrm{}}^{+}$, ${\mathrm{Ag}}_{7}$${\mathrm{}}^{+}$, and ${\mathrm{Ag}}_{9}$${\mathrm{}}^{+}$) generated in a sputtering arrangement were filtered in energy sele…
Composition-dependent hydrogen motion in a random alloy,VxNb1−xH0.2: From localized motion at V atoms to long-range hydrogen diffusion
Proton spin-lattice relaxation times (${T}_{1}$) measured for the first time across a random transition-metal alloy system, ${\mathrm{V}}_{\mathrm{x}}$${\mathrm{Nb}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{H}}_{0.2}$, from 100 to 700 K reveal (a) a suppression of hydride phase precipitation at low temperatures…
Novel surface phase transition in nematic liquid crystals: Wetting and the Kosterlitz-Thouless transition
The growth of nematic films near a wall close to the nematic-isotropic transition is studied for planar boundary conditions. If the nematic phase wets the wall, near the onset of bulk nematic behavior the nematic film near the wall is in a Kosterlitz-Thouless low-temperature phase. The transition to this phase can be…