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Extracts from technical journals

Influencia del medio ambiente en los materiales de construcción II. La Humedad

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Contribución al estudio de los reacciones de hidratación del cemento portland por espectroscopia infrarroja II. Estudio de clínkeres y de cementos portland anhidros

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Estudios espectroscópicos de silicatos Contribución a la determinación espectroscópica de aniones silicatos en silicatos de calcio hidratados

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Phosphate – clay mineral relations in soils and sediments

The geochemical constraints that determine the environments of formation of calcium and aluminum phosphates are assessed in relation to the stabilities of these compounds. In neutral to acidic environments, the weathering of calcareous phosphorites may result in the formation of crandallite and wavellite (low phosphat…

Polarity-dependent memory switching and behavior of Ag dendrite in Ag-photodoped amorphous As2S3 films

High cyclical reproducibility in polarity-dependent switching and memory function was obtained. Switching and memory effect seem to occur when both electrodes (Mo and Ag) are bridged by Ag dendrite which originates as the result of Ag photodoping. The combination of Ag electrode and another kind of electrode material…

Viscous liquids and the glass transition. V. Sources of the excess specific heat of the liquid

The possibility that the excess ’’configurational’’ specific heat ΔCp of liquids above the glass transition temperature Tg might contain contributions either from changes in vibrational frequencies with configurational state, from changes in the anharmonicity of vibrations, or from the influence of changes in configur…

Acoustic phonon instabilities and structural phase transitions

Structural phase transitions are considered in which the order parameter is a homogeneous deformation of the crystal. The fluctuations at these transitions are the acoustic modes, and it is shown that an effective Hamiltonian may be constructed describing the homogeneous deformations and their fluctuations. There are…

Observation of Two-Dimensional Phases Associated with Defect States on the Surface of TiO2

Surface electronic states associated with defects produced by Ar-ion bombardment of Ti${\mathrm{O}}_{2}$ crystals have been studied by ultraviolet-photoemission, electron-energy-loss, and Auger spectroscopy and low-energy-electron diffraction. Evidence is given for three distinct phases dependent upon the extrinsic su…

Surface-Electromagnetic-Wave-Enhanced Raman Scattering by Overlayers on Metals

Using a general formulation we show that by using surface electromagnetic waves in an attenuated-total-reflection prism configuration it should be possible to enhance the intensity of Raman scattering by a thin overlayer on a Ag surface by two orders of magnitude and that the use of surface electromagnetic waves may i…

The exponential and power laws of stress relaxation kinetics and a general relation between the activation volume and effective stress

When calculating the well-known inverse stress dependence of the activation volume, v, from stress relaxation kinetics, the relation vσ* = (10 ± 1) kT is obtained from experiments for both metals and polymers. The stress σ* is either the initial stress σ of the relaxation experiment, in which case v is calculated from…

Oxygen diffusion in BaTiO3 ceramic

High resistivity diffusion layers are formed by reoxidation between 380 and 750 °C in reduced BaTiO3 ceramic. The potential distribution is measured with an applied voltage at these samples. In addition, observations with the polarizing microscope, resistance and gravimetric measurements are made. The results show tha…

Resonant electronic-to-rotational energy transfer: Quenching of F (2P1/2) by H2 (j=0)

Coupled-channel calculations of cross sections for quenching of F (2P1/2) by H2(J=0) are carried out over an energy range of 0.135–1.565 kcal/mole. (AIP)

Tautomeric equilibrium study of thiazolidine-2-thione. Transition metal complexes of the deprotonated ligand

The complexes of deprotonated thiazolidine-2-thione (ttz) with many transition metals have been prepared. Probable structures have been proposed for the complexes on the basis of chemical analysis, spectral data (infrared and visible), and magnetic susceptibility measurements. The ligand field parameters have been eva…

Lattice dynamics ofK2Pt(CN)4Br0.3.3.2D2O (KCP) studied by inelastic neutron scattering

The lattice-dynamical properties of the "quasi-one-dimensional conductor" ${\mathrm{K}}_{2}$Pt${(\mathrm{CN})}_{4}$${\mathrm{Br}}_{0.3}$.3.2 ${\mathrm{D}}_{2}$O (KCP) has been studied by neutron inelastic scattering at temperatures between 20 and 240 K with special attention to the relation to the partial three-dimens…

Domain Switching Behaviour of Ferroelastic LaNbO4and NdNbO4

Ferroelastic domain switching behaviour is observed in large and high quality LaNbO 4 and NdNbO 4 single crystals grown by the Czochralski method. The domain walls which are (10\bar2) and (201) twin planes move when a small stress is applied, and return to the initial positions when the stress is removed. This back -…

Transparent electrode properties of cadmium stannate

Thin films of semiconducting n-type cadmium stannate (Cd2SnO4) have been coated onto different substrate materials by rf sputtering. The films are transparent in the visible and near-infrared part of the optical spectrum and electrically conductive. Conductivities as high as 6500 Ω−1 cm−1 have been achieved. Transpare…

Thermoreflectance spectra of CdO: Band gaps and band-population effects

Thermoreflectance spectra of semiconducting CdO single crystals at 100\ifmmode^\circ\else\textdegree\fi{}K with carrier concentrations in the range (2-40) X ${10}^{18}$/${\mathrm{cm}}^{3}$ give 2.28 eV for the direct ${\ensuremath{\Gamma}}_{15}\ensuremath{-}{\ensuremath{\Gamma}}_{1}$ gap. Two indirect gaps are found:…

Heat capacity and thermal conductivity of hexagonal pyrolytic boron nitride

We have measured the heat capacity and thermal conductivity of the layered material hexagonal pyrolytic boron nitride from 2 to 10 K by a pulse-heating technique. The thermal conductivity has also been determined by a steady-state technique from 1.5 to 350 K. At low temperatures, the heat capacity has a ${T}^{3}$ depe…

The inversion parameter with respect to the space group of MgAl2O4spinels

The inversion parameter is determined for several samples by ESR. It is shown that MgAl 2 O 4 is partly inverse and that the cation distribution varies markedly from sample to sample. A possible correlation between the space group of spinels and the cation distribution is discussed.