Estimation of the sensitivity of the electrical energy demand to variations in meteorological conditions: History of methods and development of new approaches at EDF

The development of electrical heating makes French consumption of electrical energy increasingly sensitive to climatic random variations, and this considerably complicates the a posteriori analysis of realizations, not only for itself, but also as a help in forecasting. The necessity of having homogenous realizations as far as meteorological conditions are concerned, has led, for many years, to diverse reseacch and development projects at Electricité de France. A comprehensive survey is given of EDF activities in this area until the end of 1981. The results obtained by various techniques (linear or nonlinear regression methods, ARIMA models with transfer function and adaptive filtering techniques) are described.     

Are there still indications for cerclage in 1995?

AIM: In order to assess their undertook a retrospective study in their department over a 4 year period: from January 1991 to December 1994. METHOD: the study concerned 129 patients who were treated by cerclage. This procedure was performed prophylactically in the great majority of them (97), while it was carried out as an emergency in 32 (25%). RESULTS: the authors drew a distinction between two groups (prophylactic and emergency suture) when analyzing the various results: complications due to suture, mean age of pregnancy at delivery, threatened premature labor, mean length of prolongation obtained. These personal data formed the basis of a review of the literature, in order to specify the indications for suture adopted by various authors at the present time. CONCLUSION: the authors found themselves to be in agreement with data from the literature, considering a history of at least two obstetric accidents (late abortions) and/or the existence of a severe uterine malformation to be the principal indication for prophylactic suture. "Emergency" suture should be performed whenever there is a serious threat of early premature labor in the presence of cervical changes such that suture offers the only chance of prolonging the pregnancy.     

A method for elastic modulus measurements of magnetron sputtered thin films dedicated to mechanical applications

Mechanical properties of thin films may highly differ from those of chemically identical bulk materials. Their knowledge is of paramount importance for coatings manufacturers. In this paper, attention is paid on Young's modulus measurements of PVD magnetron sputtered thin films on metallic substrates. The method is based on the three-point bending test of partially coated stainless steel or titanium alloy substrates. After derivation of the corresponding equations, the method and its accuracy according to qualification tests are first described. Results are then presented for coatings as varied as C, W, Cr(C), and TiN with thicknesses spanning 0.5–10 μm, and deposited under different sputtering conditions. It is first seen that the Young's modulus highly depends on the deposition parameters, varying from the bulk values down to the fourth of this value. In the case of reactive sputtering, the evolution of the modulus with the gas flow is also presented and a correlation with phases or microstructure is observed. It is finally concluded that this kind of test, owing to its simplicity and its reliability, may help on a scientific point of view towards understanding the influence of morphology on mechanical properties, and on a practical basis for ensuring a control quality reference when performed systematically after deposition. Some foreseen extensions of this work to adhesion measurements will be mentioned shortly.     

Étude de la stabilité d’un estimateur de puissance en métrologie des bruits d’avion

Annals of Telecommunications - Pour replacer dans son contexte particulier le problème général de l’estimation de la puissance d’un bruit en sortie d’un filtre...