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31.
The purpose of this work is to present a novel strategy for real-time monitoring crack growth of materials. The process is based on the use of thermal data extracted along the horizontal axis of symmetry of single edge notch tension (SENT) specimens, during fatigue tests. These data are exploited using an implemented program to detect in situ the growth of fatigue crack, with the critical size and propagation speed of the crack. This technique has the advantage to be applicable to a wide range of materials regardless of their electrical conductivity and their surface texture. To cite this article: D. Ait Aouit, A. Ouahabi, C. R. Mecanique 336 (2008). 相似文献
32.
B. F. Belaribi G. Belaribi-Boukais A. Ait Kaci J. Jose 《Journal of Thermal Analysis and Calorimetry》2000,61(3):787-803
The authors have measured the vapour pressure of the binary systems, piperidine+n -butylamine, piperidine+dipropylamine, piperidine+N-methyl piperidine, piperidine+N,N-dimethyl amino butane and N-methyl
piperidine+n -butylamine. The measurements were carried out using an isoteniscope built by Jose [1]. The vapour pressure, excess Gibbs
free energies at 298,15, 303,15, 313,15, 323,15, 333,15, and 325,15 K, are reported for these mixtures. The excess Gibbs free
energies have been fitted to Redlich-Kister equation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
33.
Patricia Gizecki Ramzi Ait Youcef Cline Poulard Robert Dhal Gilles Dujardin 《Tetrahedron letters》2004,45(52):9589-9592
Under Lewis acid conditions, reaction of N-Boc, O-Me acetals with the (R)-(+)-O-vinyl-pantolactone does not lead to the expected dihydrooxazine, but to the corresponding tetrahydrooxazinone, as a result of the loss of the t-Bu group. A diastereoselective and asymmetrical way to these new heterocyclic compounds is described, together with the first evidence of their ability to undergo N-acylation. 相似文献
34.
The paper is devoted to studying the lower semicontinuity of vector-valued mappings. The main object under consideration is
the lower limit. We first introduce a new definition of an adequate concept of lower and upper level sets and establish some
of their topological and geometrical properties. A characterization of semicontinuity for vector-valued mappings is thereafter
presented. Then, we define a concept of vector lower limit, proving its lower semicontinuity, and furnishing in this way a
concept of lower semicontinuous regularization for mappings taking their values in a complete lattice. The results obtained
in the present work subsume the standard ones when the target space is finite dimensional. In particular, we recapture the
scalar case with a new flexible proof. In addition, extensions of usual operations of lower and upper limits for vector-valued
mappings are explored. The main result is finally applied to obtain a continuous D.C. decomposition of continuous D.C. mappings.
Dedicated to Alex Rubinov in honor of his 65th birthday 相似文献
35.
The excess molar enthalpy of thiophen and diethylsulfid with some n alkanes have been measured at 303.15 K and 1 atm. A Redlich—Kister type equation was used to represent and correlate the results. Empirical equations of group contribution model, disquac have been applied for the binaries systems.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
36.
New functionalized isoxazolines were effeciently and easily prepared from limonene. The procedure involves a peri‐ and regioselective 1,3‐dipolar cycloaddition of nitrile oxides on the monoterpene external double bond, followed by a highly chemoselective RuCl3‐NaIO4 oxidative cleavage of the internal one. All the newly prepared isoxazolyl‐ketoacids were fully characterized from their spectroscopic data. 相似文献
37.
Samir Adly Maïtine Bergounioux Mohamed Ait Mansour 《Journal of Global Optimization》2010,47(3):421-435
We consider an optimal control where the state-control relation is given by a quasi-variational inequality, namely a generalized
obstacle problem. We give an existence result for solutions to such a problem. The main tool is a stability result, based
on the Mosco-convergence theory, that gives the weak closeness of the control-to-state operator. We end the paper with some
examples. 相似文献
38.
BER calculation in DS/CDMA over Rayleigh fading channel with power control error using fuzzy systems
Y. Jabrane R. Iqdour B. Ait Essaid N. Naja 《Communications in Nonlinear Science & Numerical Simulation》2009,14(2):543-551
We propose in this work, a simple method to calculate the bit error rate (BER) performance of a direct sequence code division multiple access (DS/CDMA) system over a Rayleigh multipath fading with power control error for both coherent and noncoherent reception, the RAKE structure receivers under consideration employ despreading sequences weighted (WDS) by exponential chip weighting waveforms. Numerical results show that the proposed approach reduce complexity and time of BER’s computing, then its performance does not undergo any degradation. 相似文献
39.
The following equation d2/dt2(x(t)+px(t-1))=qx(2[(t+1)/2])+f(t) is considered and necessary and sufficient conditions are given in order to ensure the existence and uniqueness of pseudo almost periodic solutions. 相似文献
40.
The topic of improving the ability of quantum systems to retain non-local features and enhance the efficiency of quantum protocols continues. This study delves into the thermal investigation of quantum correlations and teleportation fidelity of a two-qubit teleported state using excess electrons in a coupled double quantum dots system as a quantum channel. The study employs three reliable quantum quantifiers to prospect the resourcefulness and non-classicality of the system. The findings suggest that preserving quantum correlations and optimizing teleportation fidelity require minimizing tunneling coupling and maximizing Coulomb interaction. The study has significant implications for quantum physics and its practical applications in quantum information processing. 相似文献