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Hydrogen in polycrystalline diamond: An infrared analysis

Abstract Hydrogen in polycrystalline diamond (PCD) films has been analysed by infrared spectroscopy. A series of differently prepared PCD films exhibiting considerable differences in the shape of the C-H stretch absorption band has been studied. The spectra are consistently explained by a superposition of lines from s…

Incorporation of phthalocyanines by cationic and anionic clays via ion exchange and direct synthesis

Phthalocyanines (Pc) and metallophthalocyanines were incorporated into the galleries of anionic and cationic clays via ion exchange and in situ crystallization of the synthetic clay layers. Intercalation compounds between the layered magnesium silicate clay hectorite and cationic phthalocyanines were directly prepared…

Origin, Diagenesis, and Mineralogy of Chlorite Minerals in Devonian Lacustrine Mudrocks, Orcadian Basin, Scotland

Abstract Chlorite and corrensite are common clay minerals in lacustrine mudrocks from the Devonian Orcadian Basin, Scotland. The relationship of their occurrence to vitrinite reflectance data demonstrate that they are authigenic minerals, formed during burial diagenesis/metamorphism at temperatures of ≥120°C. Whole ro…

Introduction to the Rietveld method

Abstract In Chapter 2, Dr Rietveld has provided an account of the inception and early development of his method and of the growth of its acceptance from being initially ignored to the very widespread and vigorous use in many fields that it now enjoys. In this chapter, we provide a general introductory account of what…

Modelling X-ray or neutron scattering spectra of lyotropic lamellar phases : interplay between form and structure factors

The lamellar phase of two binary systems, AOT/water and DDAB/water, is studied by X-ray or neutron scattering techniques, along dilution lines. We observe on both systems a large wave vector diffuse scattering with the following features : i) its shape is independent of dilution ; ii) its intensity scales linearly wit…

Enzymatic polyesterification in organic media. Enzyme‐catalyzed synthesis of linear polyesters. I. Condensation polymerization of linear hydroxyesters. II. Ring‐opening polymerization of ϵ‐caprolactone

Abstract With the object to synthesize polyesters by enzymatic catalysis in organic media, two directions have been investigated: (1) the condensation polymerization of linear ω‐hydroxyesters and (2) the ring‐opening polymerization of lactones. The commercially‐available crude porcine pancreatic lipase (PPL), suspende…

Nature of Alumina in Phosphate Glass: I, Properties of Sodium Aluminophosphate Glass

Glasses along four compositional tie lines, I: xAl(PO 3 ) 3 ’(1 – x)NaPO 3 , II: xAlPO 4 ′(1 – x)NaPO 3 , III: xAl 2 O 3 ′(1 – x)NaPO 3 , and IV: xNaAlO 2 ,(1 – x)NaPO 3 , have been prepared and a number of their properties evaluated. In general, Al 2 O 3 additions increase the glass transition temperature, decrease t…

Prediction of dendritic spacings in a directional-solidification experiment

We present a theoretical analysis of the formation of a dendritic array in a directional-solidification experiment. Our calculation contains three sequential ingredients: acceleration of an initially flat interface and the concomitant buildup of a solutal boundary layer in front of it; onset of a morphological instabi…

Structure, spectroscopic and magnetic properties of rare earth metal(III) derivatives with the 2-formyl-4-methyl-6-(N-(2-pyridylethyl)formimidoyl)phenol ligand

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure, spectroscopic and magnetic properties of rare earth metal(III) derivatives with the 2-formyl-4-methyl-6-(N-(2-pyridylethyl)formimidoyl)phenol ligandMarius Andruh, Evangelos Bakalbassis, Olivier Kahn, Jean Christian Trombe, and Pierre PorcherCite this: Inorg. Chem.…

Nature of Alumina in Phosphate Glass: II, Structure of Sodium Alurninophosphate Glass

We have used 27 Al and 31 P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and X‐ray photoelectron spectroscopy (XPS) to describe quantitatively the relationships between the composition, structure, and properties of glasses in the Na 2 O.Al 2 O 3 .P 2 O 5 (NAP) system. In general, the glass pr…

Silsesquioxane-siloxane copolymers from polyhedral silsesquioxanes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSilsesquioxane-siloxane copolymers from polyhedral silsesquioxanesJoseph D. Lichtenhan, Ngo Q. Vu, Jason A. Carter, Jeffrey W. Gilman, and Frank J. FeherCite this: Macromolecules 1993, 26, 8, 2141–2142Publication Date (Print):April 1, 1993Publication History Published online…

Considerations and Applications of the Illite/Smectite Geothermometer in Hydrocarbon-Bearing Rocks of Miocene to Mississippian Age

Abstract Empirical relationships between clay mineral transformations and temperature provide a basis for the use of clay minerals as geothermometers. Clay-mineral geothermometry has been applied mainly to diagenetic, hydrothermal, and contact- and burial-metamorphic settings to better understand the thermal histories…

An Experimentally Derived Kinetic Model for Smectite-to-Illite Conversion and Its Use as a Geothermometer

Abstract The smectite-to-illite conversion during shale diagenesis has recently been used to constrain the estimate of a basin's thermal history. We have systematically investigated the kinetics for the conversion of a Na-saturated montmorillonite (SWy-1) to a mixed-layer smectite/illite as a function of KCl concentra…

Poly(hydroxyalkanoates): A Fifth Class of Physiologically Important Organic Biopolymers?

Abstract Along with polyisoprenoids, polypeptides, polysaccharides, and polynucleotides, Nature contains a further group of biopolymers, the poly(hydroxyalkanoates). The commonest member of this group, poly[( R )‐3‐hydroxybutyrate] P(3‐HB), had been identified by Lemoigne as early as the 1920s, as a storage substance…

Computational modelling of single crystals

The physical basis of computationally tractable models of crystalline plasticity is reviewed. A statistical mechanical model of dislocation motion through forest dislocations is formulated. Following Franciosi and co-workers (1980-88) the strength of the short-range obstacles introduced by the forest dislocations is a…

Chlorite Geothermometry: A Review

Abstract Chlorite minerals, found in a great variety of rocks and geological environments, display a wide range of chemical compositions and a variety of polytypes, which reflect the physicochemical conditions under which they formed. Of particular importance for studies dealing with ore deposit genesis, metamorphism,…

Micelles based on AB block copolymers of poly(ethylene oxide) and poly(.beta.-benzyl L-aspartate)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMicelles based on AB block copolymers of poly(ethylene oxide) and poly(.beta.-benzyl L-aspartate)G. Kwon, M. Naito, M. Yokoyama, T. Okano, Y. Sakurai, and K. KataokaCite this: Langmuir 1993, 9, 4, 945–949Publication Date (Print):April 1, 1993Publication History Published onl…

Domain wall clamping in ferroelectrics by orientation of defects

A quantitative model which describes the aging of the material properties in acceptor doped ferroelectric ceramics as a result of the reorientation of defects in time is proposed. By this reorientation the domain walls are clamped by a time dependent force leading to the observed decrease of the material properties du…