Showing papers by "Conservatoire national des arts et métiers published in 1990"
TL;DR: In this article, the maximum entropy method has been applied to the analysis of data obtained from multifrequency phase-modulation fluorometry, and real data (mixtures of dyes, dye embedded in a rigid matrix) and simulated data (broad lifetime distribution) are presented for illustrating the efficiency of the method.
58 citations
TL;DR: In this article, the authors integrate the prospective approach with that of the strategic approach, based on a rapprochement between scenario methods and trees of competence, and present an approach which enables companies to move from prospective reflection to strategic action.
54 citations
TL;DR: In this article, les proprietes electrochimiques et de la conductivite des polymeres obtenus par polymerisation electrolytique des thiophenes substitues en 3 par les groupes CH 2 -CH 2 C 6 F 13 (1) (CH 2 ) 3 C 6F 13 (2) and CH 2 3 C 4 F 9 (3).
49 citations
Journal Article•
TL;DR: There is a significant relationship between vitamin A deficiency and a malarial attack and a significant correlation was established between the results of the ICT test and two biochemical parameters (retinol, transthyretin).
Abstract: The vitamin A status of 454 pre-school age Congolese children was evaluated by the impression cytology method with transfer (ICT) and by the determination of plasma retinol. During malarial attacks, the vitamin A status is abnormal (deficient or marginal) in 40.8% of the children according to the ICT test and in 37.5% of the children who have plasma levels of retinol lower than 10 micrograms/dl. The mean concentration of plasma retinol in patients during malarial attacks (14.8 +/- 9.5 micrograms/dl) is significantly lower than the values found in other subjects (31.5 +/- 14.3 micrograms/dl) (p less than 0.001). A significant correlation was established between the results of the ICT test and two biochemical parameters (retinol, transthyretin). We conclude that there is a significant relationship between vitamin A deficiency and a malarial attack.
31 citations
TL;DR: It is shown that by reformulating the conditions defining deadlocks in terms of logic programming problems featuring the special structure known as Hornsatisfiability, polynomial algorithms can be derived for solving the following problems: find a deadlock containing a specified subset of places or decide that the given Petri net does not contain any.
29 citations
TL;DR: It is suggested that total Fe available in the typical diets of West African countries does not meet the physiological requirements of large proportions of the population.
Abstract: Iron absorption from three typical West African meals was measured in fourteen subjects using the extrinsic-tag technique with 59Fe and 55Fe. All meals consisted of maize as the staple food. Meals were prepared in Benin under realistic conditions from locally grown foods. Of the non-haem-Fe in the meals 39-73% did not exchange with the added inorganic radio-Fe tracer, depending on the degree of Fe contamination of meals. Non-haem-Fe absorption was low in each maize meal, but was even lower for those eaten with a vegetable sauce than for those eaten with a fish sauce. When haem-Fe absorption was included, 70.0-160 micrograms Fe was absorbed. Expressed on an energy basis, the bioavailable nutrient density was 3.2-7.0 micrograms/100 kJ (13.4-29.5 micrograms/100 kcal). These findings suggest that total Fe available in the typical diets of West African countries does not meet the physiological requirements of large proportions of the population.
26 citations
TL;DR: In this paper, the acidity effect of the counterions follows the order: Na+ < Ca 2+ ≈ Mg 2+ < Zn2+ < Al 3+
19 citations
TL;DR: Body weights of pair-fed rats were lower than those of anemic rats from the 1st to the 3rd week of diet; thereafter, differences between the two groups were no longer significant.
Abstract: Weanling Wistar rats were given a low-iron diet (4-5 mg Fe/kg), a medium-iron diet (20 mg Fe/kg) or a control diet (40 mg Fe/kg) for 7 weeks Pair-fed rats received the control diet in amounts equivalent to that consumed by animals on a low-Fe diet Blood samples from the tail vein were taken after 4 weeks of diet and weekly during the following 3 weeks for determination of iron status parameters Animals were weighed weekly After 4 weeks of diet, the rats fed the 5 mg iron/kg diet were severely anemic and rats fed 20 mg iron/kg diet were moderately iron-deficient Ad libitum and pair-fed controls had normal iron status Total liver iron stores were lowest in anemic rats (p less than 0001) and were also low in moderately iron-deficient animals (p less than 005) Growth rates decreased early in anemic and pair-fed rats Both groups were smaller than controls and moderately iron-deficient rats after 2 weeks (p less than 005) and this continued until the end of the experiment (p less than 0001) Body weights of pair-fed rats were lower than those of anemic rats from the 1st to the 3rd week of diet; thereafter, differences between the two groups were no longer significant
18 citations
TL;DR: Predictive control by inversion is applied to nonlinear systems and problems related to singularities and non minimum-phase are most simply overcome by introducing a discontinuous control approach.
Abstract: Predictive control by inversion is applied to nonlinear systems. Problems related to singularities and non minimum-phase, which often arise in this context, are most simply overcome by introducing a discontinuous control approach. Such a solution is illustrated on a heat exchanger example.
16 citations
TL;DR: In this article, the standard deviation of the fittings were 15 kHz and 115 kHz respectively for the R (12)26-0 and R (106)28-0 lines in the B-X system.
15 citations
TL;DR: In this paper, surface plasmons in silver particles are generated by heating a very thin silver film (7 nm) evaporated on an oxidized aluminium substrate, and the quantum yield reaches a value of 24 × 10−2 electrons per incident photon at the above mentioned wavelength.
TL;DR: The vitamin A level was inversely related to the activities of drug metabolizing enzymes induced by coplanar compounds (cytochrome P-450 towards benzo[a]pyrene and UDP glucuronosyl transferase towards 4-nitrophenol).
TL;DR: Although there were several correlations between serum ferritin and the intake of heme iron, animal proteins, ascorbic acid, meat and fish, vegetables and fruits, no relationship was found between the biochemical indicators of iron status and the total iron dietary intake.
TL;DR: This fluorescent probe is shown to heavily label the glycocallix of all the mycoplasma strains tested which are found to be associated with contaminated cultured cells and to allow an easy and rapid detection of contamination by fluorescence microscopy and flow cytometry.
TL;DR: A new polycation fluorescent dye (BVC-kinamycin-conjugate) has been synthesized and used to detect alive bacteria by flow cytometry and has the noteworthy property of being excited at the same wavelength as fluoresceinylated conjugates.
Abstract: A new polycation fluorescent dye (BVC-kinamycin-conjugate) has been synthesized and used to detect alive bacteria by flow cytometry. This fluorescent chromophore has the noteworthy property of being excited at the same wavelength as fluoresceinylated conjugates (488 nm) and to show a much longer emission wavelength (616 nm) than fluoresceinylated derivates (520 nm); furthermore its fluorescence intensity is not quenched at low pH in contrast with fluorescein. In such conditions, bacteria can easily be detected with cytofluorimeter equipped with a single excitation wavelength beam. The binding of fluoresceinylated lectins and antibodies onto a strain of Agrobacterium tumefaciens has been studied by this method.
TL;DR: Eyike et al. as discussed by the authors studied the CO 2 sheet at Lake Nyos during their field trip to the lake in 1986 and found that CO 2 sheets can be traced back to the events of December 30, 1986.
TL;DR: Ge Geoffroy's table of proportions is described in this article, and the context in which it was developed is discussed, and subsequent tables, particularly those of Bergman, are dealt with at some length.
Abstract: The paper describes Geoffroy's table of proportions. The context in which it was developed is discussed, and subsequent tables, particularly those of Bergman, are dealt with at some length. The impact that such tables, known as affinity tables, had during the 18th century, and the reasons of their vogue receding with the birth of modern chemistry at the time of Lavoisier and Dalton are analysed.
TL;DR: In this article, a two-population model is proposed for interpreting experimental reflectance curves of thin Ag granular films supported by an oxidized Al substrate, and the Yamaguchi approach is used to describe the dipolar coupling between particles and with the substrate.
TL;DR: In this article, Fatigue crack growth rate data for long and short cracks were obtained from two high strength steels used in the aerospace industry and differences in the behavior of the two cracks were noted and explained in terms of the three-dimensional nature of short cracks compared to two-dimensional long cracks, the interaction between cracks, and their effect of crack closure.
Abstract: — Fatigue crack growth rate data for long and short cracks were obtained from two high strength steels used in the aerospace industry. Differences in the behaviour of the two cracks were noted and explained in terms of the three-dimensional nature of short cracks compared to two-dimensional long cracks, the interaction between cracks, the applicability of Linear Elastic Fracture Mechanics (LEFM) and their effect of crack closure.
01 Jan 1990
TL;DR: In this paper, the Navier-Stokes equations were written in the stream-function vorticity formulation and the governing equations were solved in conservative form for two-dimensional laminar natural convection in a low Prandtl number-fluid enclosed in a shallow cavity with different end temperatures and conducting horizontal walls.
Abstract: In this paper we present finite-difference computations for two-dimensional laminar natural convection in a low Prandtl-number-fluid enclosed in a shallow cavity with different end temperatures and conducting horizontal walls. The Navier-Stokes equations were written in the stream-function vorticity formulation and the governing equations were solved in conservative form.
01 Jun 1990
TL;DR: In this paper, a couche d'argent tres mince and continue, initialement deposese par evaporation dans l'ultra-vide sur un support d'aluminium non oxyde, de d=1 a 125 nm a l'aide d'une vingtaine d'evaporations successives.
Abstract: On fait croitre l'epaisseur d'une couche d'argent tres mince et continue, initialement deposee par evaporation dans l'ultra-vide sur un support d'aluminium non oxyde, de d=1 a 125 nm a l'aide d'une vingtaine d'evaporations successives. Pour d<7 nm, les courbes du pouvoir reflecteur, relevees in situ, sont depourvues du pic d'absorption correspondant a l'excitation des plasmons de surface via la rugosite naturelle de l'argent, ce qui indique que la surface est relativement lisse. L'emission optique (300<λ<375 nm) de la couche bombardee par des electrons de faible energie (4
TL;DR: In this paper, the diastereoselectivity of the cycloaddition depends on the nature of the allylic and nitrogen substituents, and it is shown that nitrogen substitutions have a good yield (70-89 %) from azatrienes.
01 Jul 1990
Abstract: 2014 We report a self-bonding experiment with 10 cm diameter silicon wafers. Different methods were used to characterize the quality of the bonded interfaces : mechanical destructive testing, optical (by infrared imaging) and acoustical non-destructive testings ; PN test-diodes were used also to map the bonding voids. Bonded interfaces were found void-free over at least 80 % of the wafer surface. Size variations of unbonded areas with temperature were quantitatively investigated : we show that bonding voids at an interface are of two kinds, according as their size increases or decreases with thermal treatment at 1 200 °C. Revue Ph,ys. Appl. 25 (1990) 763-773 JUILLET 1990,’
01 Jan 1990
TL;DR: In this article, a tensile area more or less wide appears in the medium of a molded sample for specific molding temperatures on the walls, while a compressive area is identified at the same time close to the surface.
Abstract: Polymers properties depend as well on resins and additives characteristics as on mol¬ding conditions and thermodynamical parameters. The study of polycarbonates shows that a tensile area more or less wide appears in the medium of a molded sample for specific molding temperatures on the walls, while a compressive area is identified at the same time close to the surface.These phenomenas have been studied and their incidence on particular mechancial properties of injected samples is related.
20 Dec 1990
TL;DR: ODILE as discussed by the authors is a logiciel interactif d'assistance linguistique based on the Macintosh, designed for the use of dictionnaires usuels, which doit permettre la mise en relation de textes en langue naturelle avec des dictionnaires.
Abstract: Ce memoire traite de la conception et de la realisation d'un logiciel interactif d'assistance linguistique sur Macintosh. Il doit permettre la mise en relation de textes en langue naturelle avec des dictionnaires usuels. Pour cela, le logiciel a concevoir doit integrer et faire cooperer des outils preexistants, savoir un lemmatiseur, charge de la fabrication d'entrees potentielles de dictionnaire apres analyse du texte en entree, et un outil d'acces des dictionnaires. Il doit etre le plus universel possible pour pouvoir exploiter la diversite des lemmatiseurs et des outils dictionnaires existants. Les lemmatiseurs PILAF et ATEF et differents outils d'acces aux dictionnaires tels que WinTool , WinFile et Word Finder sont presentes, avant de fixer notre choix sur PILAF et WinTool la realisation de notre prototype. Dans ce memoire, nous proposons, pour l'integrateur ODILE, une interface utilisateur qui reponde a un certain nombre de principes ergonomiques. Nous definissons egalement des interfaces programme generales pour la communication des deux logiciels avec notre outil. Nous nous sommes egalement preoccupe de l'evolution de notre outil ; en particulier nous souhaitions en faciliter la maintenance. Le souhait d'une architecture nodulaire pour-ODILE a ete l'occasion, pour nous, d'etudier le modele PAC de structuration logicielle des systemes interactifs. Dans l'implementation actuelle, nous en avons retenu certains aspects interessants. Le besoin d'ameliorer les performances du lemmatiseur integre nous a conduit reviser la structure de son dictionnaire. Nous examinons plusieurs organisations possibles
01 Jan 1990
TL;DR: In this article, a wide space is given to the notion of composites damaging and to the peculiar effect of the sollicitation in compression, and the State of the main knowledge published in the litterature is summarized.
Abstract: From results obtained in our laboratory, we sum in this paper the State of the main knowledge published in the litterature. Only high performance composite materials are studied. Their fatigue resistance is compared with competing alloys. A wide space is given to the notion of composites damaging and to the peculiar effect of the sollicitation in compression.
TL;DR: In this article, it is shown that the demande de raccordement is a fonction croissante du nombre de services disponibles sur le reseau.
Abstract: L’apparition des services a peage sur le marche des telecommunications conduit a analyser les phenomenes d’externalites indirectes qui peuvent exister entre les individus demandant leur raccordement au reseau, les entreprises prestataires de services et l’exploitant de telecommunication qui possede les infrastructures et qui effectue le raccordement. Il est possible de montrer que la demande de raccordement est une fonction croissante du nombre de services disponibles sur le reseau. Symetriquement le nombre de services offerts est une fonction croissante du nombre d’individus raccordes au reseau. Ainsi modelise, le marche des services a peage peut etre analyse d’un point de vue dynamique. On distingue dans un premier temps les equilibres stables et les equilibres instables du marche. Dans un second temps, on montre comment une situation d’information imparfaite pour les offreurs et les demandeurs de services peut perturber la dynamique de croissance du marche sans pourtant modifier la position des points d’equilibre eux memes.
TL;DR: In this paper, the first paper devoted to linear electronic transport properties in strongly coupled plasmas consisting of a multicomponent and classical ionic mixture embbedded in a highly degenerate electron jellium was published.
Abstract: This is the first paper in a series devoted to a systematic investigation of linear electronic transport properties in strongly coupled plasmas consisting of a multicomponent and classical ionic mixture embbedded in a highly degenerate electron jellium. The basic formalism rests upon suitable extensions of the Boltzmann-Ziman theory as explained in this work. It is hereafter specialized in a thorough investigation of thermoelectronic and mechanical transport coefficients. Validity conditions for the Lorentzian approximation are first carefully examined. High temperature and inelastic corrections are emphasized. Basic transport quantities are expressed under an analytic and compact form both in the elastic and i Cet article est le premier d'une serie consacree a l'etude systematique du transport electronique lineaire dans les plasmas denses fortement couples, comportant plusieurs especes ioniques classiques plongees dans un jellium electronique fortement degenere. Le formalisme retenu, specialise ici au cas des coefficients thermoelectroniques et du transport mecanique (viscosite), repose pour l'essentiel sur l'extension de la theorie de Boltzmann-Ziman, dans le cadre de l'approximation Lorentzienne. Les conditions de validite de cette derniere sont largement developpees, et l'accent mis sur les corrections de temperature finies et les corrections inelastiques. Les coefficients de transport sont exprimes analytiquement sous forme de quantites reduites, a la fois dans le cas elastique et inelastique, respectivement au moyen des solutions exactes et variationnelles de l'equation de transport. Ceci permet un calcul simplifie des corrections precedemment mentionnees, calcul qui sera detaille dans l'article II de cette serie. Finalement, nous demontrons la validite de la methode en reproduisant, dans les limites appropriees, les formules de Ziman et d'Edwards pour la resistivite, ainsi que d'autres resultats bien connus