Toward the synthesis of thiadiazole-based therapeutic agents: synthesis,spectroscopic study,X-ray analysis,and cross-coupling reactions of the key intermediate 3,5-diiodo-1,2,4-thiadiazole

Research on Chemical Intermediates - The 1,2,4-thiadiazole moiety is an important component of several biologically active compounds, and varying substituents on this aromatic ring is one of the...     

Synthese de dienes-1,3 et de styrenes fonctionnalises par carbopalladation catalytique d'allenes

The palladium (O) catalyzed reaction of aryl and vinyl halides with allenes in the presence of sodium ethyl malonate leads with good yields and in certain cases with high stereoselectivity to styrenes and 1,3-butadienes derivatives.     

Use of the rotating disk electrode with ring for studying the products resulting from electroreduction of organomercury compounds

Conclusions The rotation disk (cathode) electrode with ring (anode) has been used to study the products resulting from reduction of (C₆F₅)₂Hg and (PhC=C)₂Hg in dimethoxyethane and acetonitrile. In dimethoxyethane, these processes led to one-electron ring oxidation of the C₆F₅ ^– and PhC=C^– anions, giving rise to one wave on the polarogram; in acetonitrile, this wave was accompanied by a second wave which arose through oxidation of products from carbanion-solvent interaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 760–766, April, 1979.     

Détection de fissures dans les poutres d'acier : une nouvelle approche par balayage de mesures de vibrations

In the last few years, the techniques of detection and identification of damage in structures benefited from important research efforts. Several methods of non-destructive damage detection, such as techniques based on modal analysis, were developed in addition to the traditional methods. The difficulties encountered by these techniques are their low performance, considering the industrial requirements to detect cracks as early as possible.     

Homogenization of multicoated inclusion-reinforced linear elastic composites with eigenstrains: Application to thermoelastic behavior

A new micromechanical approach for arbitrary multicoated ellipsoidal elastic inclusions with general eigenstrains is developed. We start from the integral equation of the linear elastic medium with eigenstrains adopting the Green's function technique and we apply an ‘(n+1)-phase’ model with a self-consistent condition to determine the homogenized behavior of multicoated inclusion-reinforced composites. The effective elastic moduli and eigenstrains are obtained as well as the residual stresses through the local stress concentration equations. The effective eigenstrains are determined either with the concentration tensors obtained here by the present model, or, more classically, with Levin's formula. In order to assess our micromechanical model, some applications to the isotropic thermoelastic behavior of composites with and without interphase are given. In particular, ‘four-phase’ and ‘three-phase’ models are derived for isotropic homothetic spherical inclusion-reinforced materials, and the results are successfully compared to exact analytical solutions regarding the effective elastic moduli and the effective thermal expansion.     

Pyrolysis of corrugated cardboard in inert and oxidative environments

The thermal decomposition of corrugated cardboard has been studied in inert and oxidative (non-flaming) atmospheres under a range of radiant heat fluxes relevant to fire conditions in warehouse storage applications. Experiments were performed in a Fire Propagation Apparatus (FPA) on double-wall corrugated cardboard at heat flux levels of 20, 60, and 100 kW/m². Pyrolysis data comprised of gasification rates and surface temperatures were collected for tests carried out in ambient atmospheres consisting of 100% N₂ as well as 2%, 6%, 8%, 10%, and 14% (mol) O₂ in balance nitrogen. It is shown that the presence of oxygen has an appreciable effect at all heat flux levels; however, it is most prevalent at low heat fluxes. Analyses are presented in an effort to gain further understanding of char oxidation processes. Results show that the maximum heat evolved in oxidative environments is relatively constant and similar for all conditions tested. Furthermore this heat release rate is found to be comparatively small relative to the high radiant fluxes tested; this explains the experimentally observed behavior. This study provides a comprehensive dataset that may be used in conjunction with approaches recently adopted in the fire community in which optimization procedures are employed to generate material properties for pyrolysis models used in CFD fire simulations.     

Ionic conduction and effect of immobile cation substitution in binary system (AgI)4/5–(PbI2)1/5

Samples of stoichiometry (AgI)₄(PbI₂)_1?x (CdI₂) _x , (0 ≤ x ≤ 0.4), have been prepared and studied by electrical conductivity, X-ray powder diffraction and DSC techniques. The ionic conductivity of samples was found to increase with temperature, and an abrupt increase at phase transition temperature was observed. The Cd⁺²-doped samples exhibited lower phase transition temperature compared to that of the pure samples. The ionic conductivity decreases with an increase in Cd⁺² content in pre-transition, while enhances in conductivity result in Cd⁺² content samples of x ≤ 0.2 in the post-transition region. Different resources of investigation confirmed the solubility limit of Cd⁺² in the high-temperature phase to be x = 0.2. The change in the ionic conductivity of Cd⁺²-doped samples is explained by the increase in the defect concentration and the free volume available in the lattice. The drop in phase transition temperature of Cd²⁺-doped systems is attributed to the lattice distortion and the increase in the defect–defect interaction.     

Testing for nonlinear dependence in financial markets

This article addresses the question of improving the detection of nonlinear dependence by means of recently developed nonparametric tests. To this end a generalized version of BDS test and a new test based on symbolic dynamics are used on realizations from a well-known artificial market for which the dynamic equation governing the market is known. Comparisons with other tests for detecting nonlinearity are also provided. We show that the test based on symbolic dynamics outperforms other tests with the advantage that it depends only on one free parameter, namely the embedding dimension. This does not hold for other tests for nonlinearity.     

A cotangent fibre generates the Fukaya category

We prove that the algebra of chains on the based loop space recovers the derived (wrapped) Fukaya category of the cotangent bundle of a closed smooth oriented manifold. The main new idea is the proof that a cotangent fibre generates the Fukaya category using a version of the map from symplectic cohomology to the homology of the free loop space introduced by Cieliebak and Latschev.     

Convergence of Ishikawa’s iteration method for pseudocontractive mappings

Let C be a nonempty, closed and convex subset of a real Hilbert space H. Let T_i:C→C,i=1,2,…,N, be a finite family of Lipschitz pseudocontractive mappings. It is our purpose, in this paper, to prove strong convergence of Ishikawa’s method to a common fixed point of a finite family of Lipschitz pseudocontractive mappings provided that the interior of the common fixed points is nonempty. No compactness assumption is imposed either on T or on C. Moreover, computation of the closed convex set C_n for each n≥1 is not required. The results obtained in this paper improve on most of the results that have been proved for this class of nonlinear mappings.