Materials Literature
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Abstract A potential mechanism for part of the production decline observed in the Prudhoe Bay field is siderite (iron carbonate) scale deposition. This laboratory investigation focused on evaluating the effect of the existing downhole scale inhibitor program on the proposed siderite formation damage mechanism. A tube…
Abstract Scale inhibitor "squeeze" treatments are used extensively to control problems with downhole carbonate and sulphate scale formation. The return curve from an adsorption/desorption squeeze is governed by the inhibitor/rock interaction which, in turn, is described by the adsorption isotherm. Several factors, suc…
Bundles of nanotubes were produced by vapor-phase condensation of carbon on highly oriented pyrolytic graphite and analyzed by scanning tunneling microscopy. The bundles are found to have widths between 15 and 50 nm, and up to 200 nm long. They are composed of concentric tubules with 2–4 nm in diameter. Atomic resolut…
We compute phase diagrams for diblock copolymers in the strong-segregation regime as a function of volume fraction \ensuremath{\varphi}. We include the ordered bicontinuous double-diamond (OBDD) phase, which is found to be stable between cylinders and lamellae, consistent with experiment, for \ensuremath{\varphi} (or…
First-order Raman scattering of A 1g and E g modes originating from the antiferrodistortive F 2u soft mode confirms the cubic-tetragonal (O h -D 4h ) phase transition in Sr 0.993 Ca 0.007 TiO 3 , at T 0 =125 K. Within the cubic and the tetragonal phase first-order Raman scattering of the soft ferroelectric F 1u mode (…
Abstract Thermal degradation of polyurethane samples was studied by a thermogravimetric method. The effect of soft‐segment length and soft‐segment concentration on activation energy of the degradation process was measured. Three methods of calculation gave activation energies at different stages of the very complex we…
Feldspars with up to about 45% trivalent cations on M positions were synthesized by heating gels of composition Ca 8−2x Na x La x Al 16 Si 16 O 64 at 1300°C and 1 bar. In the range O 3 this substitution is accompanied by the substitution Ca 2+ + Al 3+ → Na + + Si 4+ . As x increases, the triclinic anorthite structure…
Eine Hohlkugel aus quadratischen VO 5 ‐Pyramiden und PhPO 3 ‐Tetraedern , in deren Innerem ein Chlorid‐Ion eingeschlossen ist, so läßt sich das Anion in 1 beschreiben (Strukturbild rechts). Auf den ersten Blick ähnelt dieses Anion mit seiner kugelförmigen Gestalt bekannten Polyoxoanionen, bei genauerer Betrachtung zei…
The crystal chemistry and thermal behaviour of synthetic hercynite (FeAl 2 O 4 ), a normal spinel, produced both hydrothermally and from sintering oxides at high temperatures, were studied by means of powder XRD and Mossbauer spectroscopy. The samples were annealed at different temperatures under controlled oxygen atm…
The study of the octahedral Fe-Mg substitution in smectites was conducted using clay synthesis at 200°C. Mossbauer data revealed that only ferric iron occurs in synthesized smectites. The studied series is then obviously heterovalent. All synthesized clays were tetrahedrally charged leading to structural formulae vary…
Intercalated layered materials comprising an organic dye and inorganic MPS(3) [where M is either the manganese ion (Mn(2+)) or the cadmium ion (Cd(2+))] phases have been prepared. The intercalation process induces a spontaneous poling, giving rise to an efficiency of 750 times that of urea in second-harmonic generatio…
Compressibility of Polymers Structural Aspects of Influence of High Pressure on Polyethylene Viscoelastic and Deformational Properties of Polymers Under High Pressure PVT Effects in Molecular Dynamics of Polymers Radiation Chemistry of Polymers Under High Pressure Polymerization Under Pressure Reactions of Solid Monom…
This book gives perspective of an exciting area of new and intelligent materials for electroactive sensor applications for microelectronics (and possibly in the nanometer scale) for the twenty-first century.
The kinetics of polycondensation of lactic acid has been investigated. The resuIts showed that in the absence of catalyst the polycondensation proceeds as a third order reaction at 124℃ with 10%～60%conversion:-d[COOH]/dt=1.32×1O-5[COOH]3. In the pres-ence of ca.1%(wt) of a strong acid ion-exchange resin at 120℃and 10%…
The acetal homopolymer is conventionally obtained by the polymerization of formaldehyde, following end capping using acetic anhydride. Asahi Chemical developed a new process to obtain an end-capped polymer during polymerization of highly purified formaldehyde using acetic anhydride as the chain-transfer agent. The use…
A model description of intermolecular electron transfer and intramolecular electron transfer (and related to it methyl transfer) reactions in organic solids are discussed. As a first step towards quantitative modeling of the reactions we construct potential energy surface in the phonon normal coordinates space. A role…
Abstract The solubility, complexation, and morphology in the Nd(NO 3 ) 3 ‐PEO and Nd(Dpm) 3 ‐PEO systems were investigated using the FTIR, DSC, TGA, WAXD, and SAXS techniques. In both systems, dissolution was verified by the absence of features characteristic of the bulk‐phase dopants detectable with WAXD and DSC, and…
Abstract The 14 N nuclear quadrupole relaxation time and resonance frequencies v + , v - , and v d of N,N-dimethylnitramine were measured between 14 and 313 K. The frequency increase of v + and v - observed below T c (108 K) is explained by the increase of p π electrons in the amino nitrogen caused by the deformation…
Abstract Einkristalle von Ba 25 Cu 14 2+ Cu 4 3+ Zn 4 O 49 wurden mit einer Kombination von Feststoff‐ und Schmelzmittel‐reaktionen dargestellt. Diese Substanz kristallisiert tetragonal, Raumgruppe D 7 4th –P4/nmm mit a = 18,2146, c = 9,3230 Å, Z = 2. Der bisher unbekannte Strukturtyp zeigt Kupfer in tetragonal pyrami…
Field measurements of beta ray energy spectra have been carried out at various locations in CANDU nuclear generating stations operated by Ontario Hydro. The beta ray energy spectrometer consists of a 5 cm diameter x 2 cm thick BC-404 plastic scintillator situated behind a 100 µm thick, totally depleted, silicon detect…