Inherent Bounds to the Elasticity and Flexoelectricity of Liquid Crystals
Phenomenological and molecular considerations indicate certain limitations to the elastic moduli and flexoelectric coefficients of liquid crystals.
Materials Literature
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Single-crystal vibrational spectra of apatite, vanadinite, and mimetite
Single-crystal Raman spectra are reported for the three title compounds, and i.r.-reflectance parameters for apatite. An essentially complete assignment is deduced for apatite, including lattice modes, and is in close agreement with the predictions of factor-group analysis. The main features of the Raman spectra of va…
Simulation de l'evolution des defauts dans un reseau par le methode de monte-carlo
La simulation du comportement dcs défauts ponctuels dans un réseau par la méthode de Monte-Carlo a pu étre rendue trés rapide gréce à I'utilistion de lois de probabilité en fonction du temps pour chaque évènement possible (création, disparition ou transformation d'un défaut), évitant ainsi le traitement de chaque saut…
Bacteroides multiacidus, a New Species from the Feces of Humans and Pigs
Ninety-five strains of Bacteroides hypermegas Harrison and Hansen and of related organisms were isolated from the feces of humans, pigs, dogs, and chickens and were compared with three authentic strains of B. hypermegas. All isolates shared certain features in common: They were gram-negative, nonspore-forming, nonmoti…
Hydrogen Embrittlement Testing
Description Nineteen papers cover internal hydrogen embrittlement, testing for relative susceptibility, testing for hydrogen pickup during processing, mechanical delay-time test, hydrogen defection methods, hydrogen environment embrittlement
Behavior of Austenitic Stainless Steels in Evaluation Tests for the Detection of Susceptibility to Intergranular Corrosion
The characteristics, advantages, and limitations of various methods for the detection of susceptibility to intergranular corrosion in austenitic stainless steels due to carbide precipitation are discussed. Information on corrosion rates and acceptance limits in nitric acid and ferric sulfate-sulfuric acid tests is pre…
X-ray photoelectron spectroscopic studies of silver(III) octaethylporphyrin
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron spectroscopic studies of silver(III) octaethylporphyrinDale Karweik, Nicholas Winograd, D. G. Davis, and K. M. KadishCite this: J. Am. Chem. Soc. 1974, 96, 2, 591–592Publication Date (Print):January 1, 1974Publication History Published online1 May 2002Pub…
Preparation of a conjugated tautomer of 1,14:7,8-diethenotetrapyrido-[2,1,6-de:2′,1′,6′-gh:2″,1″,6″-kl:2‴,1‴,6‴na][1,3,5,8,10,12]hexa-azacyclotetradecine and its metal derivatives
A hexa-aza-macrocyclic compound of high thermal stability is readily obtained from 2,9-diamino-1,10-phenanthroline by its thermolysis or by its condensation with 2,9-dihalogeno-1,10-phenanthroline. The structure of this macrocycle has been established as a conjugated system of a novel type, related to some extent to p…
Epoxy/acrylic simultaneous interpenetrating networks
Abstract Simultaneous interpenetrating networks were prepared by simultaneously synthesizing crosslinked epoxy and poly (n‐butyl acrylate) polymers. A two‐phase morphology emerged, with the dispersed rubber domains being of the order of 0.1–0.2 m̈ in size. The actual dimensions of the dispersed phase, and the extent o…
Structural studies by electron microscopy: coherent intergrowth of the ReO3and tetragonal tungsten bronze structure types in the system Nb2O5–WO3
High-resolution lattice images from WO3-rich compositions in the system Nb2O5-WO3 contain direct evidence for the coherent intergrowth of extensive domains of several orientations of the ReO3-type structure with the more complex tetragonal tungsten bronze-type structure. A model for the transformation between the two…
Influence of pH and ionic strength upon solubility of nitric oxide in aqueous solution
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of pH and ionic strength upon solubility of nitric oxide in aqueous solutionJohn N. ArmorCite this: J. Chem. Eng. Data 1974, 19, 1, 82–84Publication Date (Print):January 1, 1974Publication History Published online1 May 2002Published inissue 1 January 1974https://pu…
Neutron powder profile refinement of ferroelectric and antiferroelectric crystal structures: Sodium niobate at 22°C
The profile refinement of neutron powder patterns permits a rapid and precise determination of structural transitions. For example, the room temperature structure of the rather complex distorted perovskite NaNbO3has been obtained independently in good agreement with the X-ray measurements of Sakowski-Cowley, Lukaszewi…
Basic processes controlling the nucleation of graphite nodules in chill cast iron
This paper describes the results of an extensive microstructural study designed to explore the basic processes controlling the nucleation of graphite nodules in chill cast iron. The experimental melts were nodularized with magnesium ferrosilicon and then inoculated, either with foundry grade ferrosilicon or Superseed…
Complex formation between poly(vinyl alcohol) and metallic ions in aqueous solution
Abstract As the basic research for the study of complex reactions in polymers, the complex formation of poly(vinyl alcohol) (PVA) with copper and other metals was tried. Spectroscopy, pH titration, and elementary analysis were employed in the reaction of PVA and Cu(II) ions in aqueous solution. The complexing protonat…
Electron paramagnetic resonance study of Ce3+, Dy3+ and Yb3+ in Cs2NaYCl6. A crystal with sites of perfect octahedral symmetry
The X-band e.p.r. spectra at 4.2 K of cerium(III), dysprosium(III), and ytterbium(III) doped into cubic Cs2NaYCl6 are reported. The magnitude of the g-factor and the isotropic nature of both g and the line width indicate that the ions occupy sites of exact octahedral symmetry. Analysis of the spin Hamiltonian paramete…
The nuclear magnetic resonance spectra of porphyrins. Part VIII. The 13C nuclear magnetic resonance spectra of some porphyrins and metalloporphyrins
The 13C n.m.r. spectra of the methyl esters of the four coproporphyrin type-isomers and deuteroporphyrin-IX, and of octaethylporphyrin, and the zinc(II), thallium(III), and some diprotonated derivatives are reported and assigned. An immediate differentiation between the coproporphyrin type-isomers is provided by the s…
Deformation Pattern of Twisted Nematic Liquid Crystal Layers in an Electric Field
At rest between two metallized glass plates a nematic liquid shows a screw-like deformation pattern if one turns the plates by an angle ωm around an axis perpendicular to the plates. If a voltage U is applied, the molecules are tilted with respect to the electric field when U exceeds a threshold voltage. With increasi…
Spin state equilibria and localized versus collective d-electron behaviour in neodymium and gadolinium trioxocobaltate(III)
Magnetic susceptibility measurements and Mössbauer spectra show that NdCoO3 and GdCoO3 contain predominantly low-spin CoIII ions at low temperatures which transform partially to high-spin Co3+ until a certain temperature. Beyond this temperature, there is a transfer of eg electrons from Co3+ to CoIII giving rise to di…
Synthesis of the organic conductor tetramethyltetraselenofulvalenium 7,7,8,8-tetracyano-p-quinodimethanide (TMTSF–TCNQ)[4,4′,5,5′-tetramethyl-Δ 2,2′ -bis-1,3-diselenolium 3,6-bis-(dicyanomethylene)cyclohexadienide]
Tetramethyltetraselenofulvalene reacts with tetracyanoquinodimethane to form a highly conducting organic solid.
Eutectic mixtures of nematic 4′-substitued 4-cyanobiphenyls
A numerical technique has been used to predict eutectic compositions of some liquid crystal mixtures; good agreement was found with experimental results on mixtures of 4′-n-alkyl- and 4′-n-alkoxy-4-cyanobiphenyls some of which are nematic over the range 0–60 °C.