Materials Literature
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The ac response of polyaniline films on Pt electrodes in was measured at different applied dc potentials, varied in the positive and negative directions. Experimental complex capacitance plots were reproduced using a computer simulation program based upon the equivalent circuit approach. With 150 nm films the complex…
Abstract Polyanhydrides composed of the following diacids–sebacic acid, bis( p ‐carboxyphenoxy)propane, bis( p ‐carboxyphenoxy)hexane, isophthalic acid, 1,4‐phenylene dipropionic acid, and dodecanedioic acid–were synthesized by a melt polycondensation process. Polymers of molecular weight up to 137,010 (weight average…
Several layered perovskites $A_2Ln_2Ti_3O_{10}$ (A = K or Rb; Ln = rare earth) and their monohydrates, crystg. in tetragonal structures related to ${Sr_4Ti_3O_10}$, were prepd. The alkali ions in $K_2Ln_2Ti_3O_{10}$ are topochem. exchanged by protons in aq. acid or by other alkali ions in molten salts. $H_2Ln_2Ti_3O_{…
An investigation of the temperature programmed desorption (TPD) of CO and D2 from Ni(111) has been carried out. It has been shown that a differential method for the extraction of the kinetic parameters, threshold temperature programmed desorption (TTPD), can be applied with accuracy near the limit of zero coverage. In…
Critical conditions for shear localization in thermoviscoplastic materials are obtained in closed form for idealized models of simple shearing deformations. The idealizations, which include the neglect of heat conduction, inertia, and elasticity, are viewed as quite acceptable for many applications in which shear band…
ADVERTISEMENT RETURN TO ISSUEPREVArticleEffects of steric factors on the electrosynthesis and properties of conducting poly(3-alkylthiophenes)J. Roncali, R. Garreau, A. Yassar, P. Marque, F. Garnier, and M. LemaireCite this: J. Phys. Chem. 1987, 91, 27, 6706–6714Publication Date (Print):December 1, 1987Publication His…
A large number of species usually placed in Fragilaria have been examined, mainly by scanning electron microscopy. As a result Fragilaria is more narrowly circumscribed, with F.capucina as the type species. Six species are definitely placed in Fragilaria and others noted for further investigation. Five genera are sepa…
The topology of the integral membrane protein MalF, which is required for maltose transport in Escherichia coli, has been analyzed using fusions of alkaline phosphatase (EC 3.1.3.1). The properties of such fusion strains support a MalF structure previously proposed on theoretical grounds. Several transmembrane segment…
This book comprises an introductory lecture outlining the basic concepts and challenges in the field. This is followed by a collection of reprinted articles which are important in understanding the subject. The book will focus mainly on mathematical and physical foundations of the subject rather than experimental prog…
This study concerns the influence of the concentration of Sr2+ and Ba2+ ions in mortar batch waters upon the hydration process of various Portland and additive cements. An increase in the mechanical resistence of said cements is observed, after 28 days, when the concentration of Ba2+ and Sr2+ ions in the mortar batch…
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X-diffractometry is applied to evaluate the setting time of gypsum pastes. A direct "observation" of the crystalization phenomena, in the moment in which occurs is possible using the proper radiation, in the measure of the dimension what is observed. The observation is developed with normal techniques and instrumentat…
Abstract In some wide band gap halides of heavy alkali and alkaline‐earth metals (BaF 2 , CsCl, RbF etc.) the energy separation between the valence band involving mainly the halogen electronic states and the upper cation core band is smaller than the band gap. Under the excitation generating holes in the core band rad…
In this Work, which is the following of the others, the performance of a portland cement of a high initial resistance (P-550-ARI) —with a calculated content (Bogue) of 39.2 – 25.7 – 9.9 - 12.0 and 6.9% of C3S - C2S - C3A - C4AF and CaSO4 (II), respectively— is studied when it is submitted to the action of an magnesium…
We have carried out a series of accelerated artificial ageing tests to study the evolution of the silico-organic treatment products applied to calcareous materials of the Catedral of Oviedo. Test valoration has been made both by visual examination and weight loss measuring. We conclude by comparing different behaviour…
Laboratory testing to produce intergranular stress corrosion cracking (IGSCC) of Alloy 600 steam generator tubing in primary water environments can require lengthy exposure times, even at a temperature of 360 C (680 F). Recent testing of Alloy 600 in hydrogen-containing steam at 400 C (750 F) has shown the characteris…
The purpose of this work is to make the coupled cluster (CC) energy stationary with respect to molecular-orbital (MO) variations in the reference configuration. To achieve this, we have used the Z vector, the solution of a set of perturbation-independent CPHF-like equations, to rotate the MOs. A new energy and gradien…
Abstract A cation-exchange capacity (CEC) method based on ion-sieving properties was developed for the quantitative determination of clinoptilolite in soils. In this method, both zeolitic and non-zeolitic exchange sites in the soil sample are saturated with Na + . The CEC of the non-zeolitic exchange sites is determin…