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Resistencia química del hormigón. XXI. Influencia de la adición de escoria a un cemento portland de alta resistencia inicial. Estudio de la concentración iónica del sistema cemento 1/escoria-agua potable filtrada

In the present work, a continuation of others, there is studied the variation of the pH, and likewise the concentration of the ions Ca (II) and SO4 (II) of the means (filtered potable water) in which there have been submerged the test tube series of mortar (1:3) made with an industrial Portland cement of high initial…

Sulfatos en el cemento portland y su incidencia sobre el falso fraguado: Estado actual del conocimiento

A bibliographical study is carried out of the sulphates which may be present in the clinker and Portland cement, as likewise the effects of the aeration and temperature on the setting. This work is a prior phase of a wide experimental investigation carried out in the IETCC, on anomalies or setting and phenomena of "lu…

Ensayos de materiales en atmósferas simuladas. III. Evaluación de un sistema de simulación

The final step in the creation of a system of simulation of the drying and purification of the air, yield answer when we attempt to produce determined conditions with it. In this article are gathered the different aspects to be borne in mind in such an evaluation efficiency of the drying and purification of the air, y…

8.° Congreso Internacional de la Química de los Cementos (8.° CIQC) Comité Científico para Europa, Asia y África (CEAA). Reunión del 22-VI-83 en París

This information paper deals with the subject treated in the mentioned meeting, the third of those celebrated by the Committee. This meeting was not previously programmed and had a character merely informative. Many questions related to the Scientific Program were treated in the meeting and a final proposal was prepar…

Resistencias mecánicas del cemento. Estudio de la precisión de su medida

The present work contains a study effected in order to determine the precision of the standardized test method which is applied for the measurement of the mechanical resistences of cement or, in other words, to know the dispersion of values which may be expected, both in repeating with a material the test in the same…

Calculations of the properties of self-interstitials and vacancies in the face-centred cubic metals Cu, Ag and Au

The properties of self-interstitials and vacancies in the noble metals Cu, Ag and Au were calculated using interatomic potentials derived entirely from first principles. Self-interstitials were found to be stable in the (100) dumbbell (or split) configuration. Their formation and migration energies were 2.61, 2.20, 3.…

Surface Charging On Epoxy Spacer At Dc Stress In Compressed SF6 GAS

The charge accumulation and its mechanisms are studied based on the experiments of post and conical epoxy spacers subjected to high dc voltages in compressed SF6gas. The charge measurement is performed using electrostatic probe and dust figure techniques. The charge accumulation is strongly influenced by the surface c…

The Electrochemistry of Black Carbons

Abstract “Modifications” of carbon—as long as they predominantly have the layered graphite structure—exhibit the following properties: (1) electrical conductance, (2) the ability to accomodate ions or molecules between the layers of the lattice, and (3) the ability to react via functional groups at their surfaces (lar…

Analysis of Poly-β-Hydroxybutyrate in Rhizobium japonicum Bacteroids by Ion-Exclusion High-Pressure Liquid Chromatography and UV Detection

Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-beta-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from…

Microstructure of ionomers: interpretation of small-angle x-ray scattering data

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMicrostructure of ionomers: interpretation of small-angle x-ray scattering dataDavid J. Yarusso and Stuart L. CooperCite this: Macromolecules 1983, 16, 12, 1871–1880Publication Date (Print):December 1, 1983Publication History Published online1 May 2002Published inissue 1 Dec…

On the ability of drops or bubbles to stick to non-horizontal surfaces of solids

It is common knowledge that relatively small drops or bubbles have a tendency to stick to the surfaces of solids. Two specific problems are investigated: the shape of the largest drop or bubble that can remain attached to an inclined solid surface; and the shape and speed at which it moves along the surface when these…

Crystal Plasticity

Significant progress has been made during the past decade in incorporating micromechanics in continuum descriptions of inelastic deformation. This has led to the development of a rather comprehensive constitutive theory for rate-dependent and idealized rate-independent crystalline materials that deform plastically by…

Effect of pressure on Raman spectra of solid chlorine

The effect of pressure on Raman spectra of solid chlorine has been measured up to 45 GPa using a diamond anvil cell. The six Raman-active modes could be observed in first-order Stokes and anti-Stokes spectra at room temperature. The accidental degeneracy of the B 3g and A g lattice modes is lifted under pressure.

Are guanine nucleotide binding proteins a distinct class of regulatory proteins?

Proteins which bind guanine nucleotides are found in a diverse set of key regulatory positions. They are involved in hormone action, visual transduction, protein synthesis and microtubule assembly. In addition to their ability to bind guanine nucleotides these proteins possess several other common features. (i) They a…

Gadolinium as a contrast agent for NMR.

Gadolinium chloride (GdCl3) was studied as a contrast agent for nuclear magnetic resonance. This rare-earth element dramatically alters proton resonance (paramagnetic moment = 10.8 Bohr magnetons). Acute toxicity was determined by intravenous injections in mice; mean lethal dose was 100-200 mg of GdCl3 . 6 H2O/kg. Cha…

ChemInform Abstract: PHOTOCHEMISTRY OF TRIS(2,2′‐BIPYRIDINE)RUTHENIUM(2+) ION (RU(BPY)32+). SOLVENT EFFECTS

Abstract Die Lebensdauer der Metall‐zu‐Ligand‐CT‐Übertragung des angeregten Zustandes der Titelverbindung und die Emissionsenergie werden in verschiedenen Lösungsmitteln (CH,CI" Butyronitril, Pyridin, Propylencarbonat, DMF, H 2 O) und bei verschiedenen Temp. gemessen.

X-Ray-Photoelectron Final-State Screening in Transition-Metal Compounds

The cation $3s$ levels in fluorides of $3d$ transition elements have been systematically examined with use of x-ray photoelectron spectroscopy. It is shown that $3s$ line shapes are determined by the $3d$ populations (and consequent exchange splittings) associated with different core-hole screening conditions. The scr…

Amorphous Semiconductor Superlattices

A new class of semiconductor superlattice materials consisting of alternating layers 8-1200-\AA{} thick has been synthesized from semiconductors such as $a\ensuremath{-}\mathrm{Si}:\mathrm{H}$, $a\ensuremath{-}\mathrm{Ge}:\mathrm{H}$, $a\ensuremath{-}\mathrm{Si}{\mathrm{N}}_{x}:\mathrm{H}$, and $a\ensuremath{-}{\mathr…

Epsteinet al.Respond

Received 3 October 1983DOI:https://doi.org/10.1103/PhysRevLett.51.2020©1983 American Physical Society