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Durabilidad del hormigón: Acción de disoluciones de sulfato de calcio y de sulfato de magnesio sobre un cemento Portland de alta resistencia inicial. Influencia de la adición de escorias y de cenizas volantes

This article —included on a long time ICCET Investigation Program— studies the mechanical resistances variation, to flexure, of the 1 X 1 X 6 cm mortar samples (1:3) made with high initial resistance cement and with several slags addition (cement/slag = 85/15 - 65/35 - 40/60 and 30/70) with high furnace slag and a fly…

Macroscopical morphology of deterioration of the stone in the Cathedral of Seville, Spain

The lithotype mainly used in the construction of the Cathedral of Seville is the calcarenite from Puerto de Santa f\/laria followed by the limestone from Espera. The primordial extrinsecal factor of deterioration is the atmospherical contamination, mainly sulphur oxides and smoke, within a humid environment. From both…

Recent works carried out at the IDIEM by the group in charge of probabilistic strength of materials

This updating review describes, from the conceptual standpoint, all the research works so far carried out at the IDIEM by the group in charge of Probabilistic Strength of Materials as well as research activities under way at present. This description considers three aspects. First, the general purposes of the commente…

Fracture statistics of torsion and dispersion relations in round bars

This paper has adopted a theoretical viewpoint for studying Fracture Statistics in round bars subjected to torsion, and for determining the cumulative probabilities of fracture using Weibull's specific-risk function for materials that exhibit volume and surface brittleness. The use of the defined-functions method has…

Moisture permeability of edible films made with fatty acid and hydroxypropyl methyl cellulose

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMoisture permeability of edible films made with fatty acid and hydroxypropyl methyl celluloseRobert D. Hagenmaier and Philip E. ShawCite this: J. Agric. Food Chem. 1990, 38, 9, 1799–1803Publication Date (Print):September 1, 1990Publication History Published online1 May 2002P…

ZnS , CdS , and Zn1 − x Cd x S Thin Films Deposited by the Successive Ionic Layer Adsorption and Reaction Process

The results of the structural, optical, and electrical characterization of , , and films grown by the successive ionic layer adsorption and reaction process are presented. Polycrystalline cubic and hexagonal films grown on glass and on indium‐tin oxide covered glass have mean crystallite sizes and , and and , respecti…

γ-Isotactic polypropylene. A structure with nonparallel chain axes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTγ-Isotactic polypropylene. A structure with nonparallel chain axesStefano V. Meille, S. Bruckner, and W. PorzioCite this: Macromolecules 1990, 23, 18, 4114–4121Publication Date (Print):September 1, 1990Publication History Published online1 May 2002Published inissue 1 Septemb…

Mechanism of Cell Damage by Ultrasound in Combination with Hematoporphyrin

The mechanism of cell damage by ultrasound in combination with hematoporphyrin was studied. Mouse sarcoma 180 cell suspensions were exposed to ultrasound for up to 60 s in the presence and absence of hematoporphyrin, with and without active oxygen scavengers. The cell damage enhancement by hematoporphyrin was suppress…

Hydrodynamic transport coefficients of random dispersions of hard spheres

Accurate values for the hydrodynamic transport properties of random dispersions of hard spheres have been determined by numerical simulation. The many-body hydrodynamic interactions are calculated from a multipole-moment expansion of the force density on the surface of the solid particles; the singular lubrication for…

From semiconductor-semiconductor transition (42 K) to the highest-Tc organic superconductor, .kappa.-(ET)2Cu[N(CN)2]Cl (Tc = 12.5 K)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFrom semiconductor-semiconductor transition (42 K) to the highest-Tc organic superconductor, .kappa.-(ET)2Cu[N(CN)2]Cl (Tc = 12.5 K)Jack M. Williams, Aravinda M. Kini, Hau H. Wang, K. Douglas Carlson, Urs Geiser, Lawrence K. Montgomery, Gloria J. Pyrka, Diana M. Watkins, Jef…

Development of Superplastic Structural Ceramics

Superplastic structural ceramics (Y‐TZP, Al 2 O 3 , Si 3 N 4 , and their composites) that can withstand biaxial stretching to large strains have been developed recently. Microstructural design of these ceramics first requires an ultrafine grain size that is stable against coarsening during sintering and deformation. A…

Dielectric behavior of single crystals near the (1−X) Pb(Mg1/3Nb2/3)O3-(x) PbTiO3morphotropic phase boundary

Single crystals in the lead magnesium niobate-lead titanate-(1−x) Pb(Mg1/3 Nb2/3)O3-(x) PbTiO3 solid solution system were grown using a flux growth technique. Crystals over the compositional range of 0.3 ≤ ′ ≤ 0.4 being near the rhombohedra1 (pseudo-cubic)-tetragonal morphotropic phase boundary were characterized. The…

Structure of a protein superfiber: spider dragline silk.

Spider major ampullate (dragline) silk is an extracellular fibrous protein with unique characteristics of strength and elasticity. The silk fiber has been proposed to consist of pseudocrystalline regions of antiparallel beta-sheet interspersed with elastic amorphous segments. The repetitive sequence of a fibroin prote…

A new multiplet-cluster model for the morphology of random ionomers

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new multiplet-cluster model for the morphology of random ionomersA. Eisenberg, B. Hird, and R. B. MooreCite this: Macromolecules 1990, 23, 18, 4098–4107Publication Date (Print):September 1, 1990Publication History Published online1 May 2002Published inissue 1 September 199…

Polymer photostabilisers. Photophysical properties and stabilising efficiency

The photophysical characteristics and luminescence-spectroscopic properties of molecules with a high photostabilising efficiency are examined. It is shown theoretically that the short lifetime and (or) low population of the triplet state of the molecule are essential (but not sufficient) conditions for its use as a ph…

Electrostatic and Steric Contributions to Regulation at the Active Site of Isocitrate Dehydrogenase

The isocitrate dehydrogenase of Escherichia coli is regulated by covalent modification at the active site rather than, as expected, at an allosteric site. As a means of evaluating the mechanism of regulation, the kinetics of the substrate, 2R,3S-isocitrate, and a substrate analog, 2R-malate, were compared for the nati…

Surface Analytical Techniques

Abstract There are numerous techniques available for providing detailed compositional information of the surface of materials. This volume aims to clarify those techniques which use particles as various kinds of probes for surface analysis. For each technique it provides a description of the physical principle, the me…

Ground state and electron-magnon interaction in an itinerant ferromagnet: half-metallic ferromagnets

Electron and spin Green functions of a Hubbard ferromagnet are calculated, both starting from the Stoner ground state and for a ferromagnet with Hubbard subbands. The temperature dependences of the spin-wave stiffness and damping, the magnetisation, the local moment on a site and the thermodynamic properties are inves…

Optically detected magnetic resonance study of polaron and triplet-exciton dynamics in poly(3-hexylthiophene) and poly(3-dodecylthiophene) films and solutions

The X-band optically detected magnetic resonance of poly(3-hexylthiophene) and poly(3-dodecylthiophene) films and solutions are described and discussed. The photoluminescence-enhancing features include (i) a strong, \ensuremath{\sim}15-G-wide, asymmetric peak at g\ensuremath{\simeq}2.003; (ii) a weak peak at g\ensurem…