181 research outputs found
Neither healthy nor sick: Psychiatric standards of deviance and conformity
article relatif Ă la catĂ©gorisation du trouble mental et de la normalitĂ© par la psychiatrie amĂ©ricaineThe article examines the tensions involved in the development of treatment for mentaldisorders during the period 1950-1980 in the United States. It relates those tensions to the diffusion ofa social ideal strongly influenced by the subjectivist fervor characteristic of post-war America but alsointernally contradictory. Psychiatric diagnosis came to be seen as a way of disqualifying theindividual, and this line of criticism went so far as to question the very existence of mental illness. Butthis context also worked to identify psychic disorder with an incomplete self, so that mental healthcame to be understood as a kind of generic measure of individuality. The article first considers theantagonism between these representations as suggested by the effects they had on professionalizationand the division of labor in the psychiatric field. It then seeks to show how the set of nosographicstandards that were established at the end of the periodâthe famous DSM-IIIâoffered a means ofnegotiating and reconciling the different visions of mental disorder, by separating both health andpathology out from questions of social normalit
Automated tool for 3D planar magnetic temperature modelling: application to EE and E/PLT core-based components
International audienceThermal performance of power converters is a key issue for the power integration. Temperatures inside active and passive devices can be determined using thermal models. Modelling the temperature distribution of high frequency magnetic components is quite complex due to diversity of their geometries and used materials. This paper presents a thermal modelling method based on lumped elements thermal network model, applied to planar magnetic components made of EE and E/PLT cores. The 3D model is automatically generated from the component's geometry. The computation enables to obtain 3D temperature distribution inside windings and core of planar transformers or inductors, in steady state or in transient case. The paper details the proposed modelling method as well as the automated tool including the problem definition and the solving process. The obtained temperature distributions are compared with Finite Element simulation results and measurements on different planar transformers
IntĂ©rĂȘt d'une Source d'Energie Electrique Hybride pour vĂ©hicule Ă©lectrique urbain dimensionnement et tests de cyclage
Actuellement, la principale source d Ă©nergie embarquĂ©e dans les vĂ©hicules Ă©lectriques est composĂ©e de batteries Li-ion. Cette thĂšse fait partie des thĂ©matiques communes de travail que mĂšne L ESTACA en collaboration avec le L2EP. L objectif ce projet est d Ă©tudier l apport d une source hybride composĂ©e de batteries Li-ion et des supercondensateurs, sur les performances d un vĂ©hicule Ă©lectrique urbain.Dans un premier temps, une stratĂ©gie de gestion d energie basĂ©e sur l approche des rĂšgles dĂ©terministes a Ă©tĂ© appliquĂ©e pour montrer l intĂ©rĂȘt de l association des diffĂ©rentes technologies de batterie Li-ion (haute puissance, haute Ă©nergie) avec le supercondensateur en fonction de l autonomie voulue. Cette Ă©tude nous a permis de proposer une solution optimale (poids, volume, coĂ»t..) composĂ©e d une batterie Ă©nergĂ©tique et un supercondensateur.Dans la deuxiĂšme partie, on a suivie l Ă©volution du vieillissement des deux de deux batteries de type haute puissance et hautes Ă©nergie dans, respectivement, les configurations mono-source et hybride. Pour rĂ©aliser cette Ă©tude, un banc de tests, destinĂ© au cyclage et la caractĂ©risation des systĂšmes de stockage, a Ă©tĂ© utilisĂ©. Les rĂ©sultats obtenus, offriront la possibilitĂ© de se prononcer sur le type de batteries Li-ion qui pourrait ĂȘtre le plus intĂ©ressant pour l alimentation des vĂ©hicules Ă©lectriquesCurrently, the main embedded storage system supplying the electric vehicles is composed of Li-ion batteries. This thesis is one of the common themes of work that ESTACA leads in collaboration with L2EP. The objective of this work is to study the interest of a hybrid source composed of Li-ion batteries and supercapacitors to supply an urban electric.Firstly, an energy management strategy based on deterministic rules is developed to control the power between the battery and supercapacitor. To demonstrate the combination utility, different Li-ion battery technologies (Li-ion high power, high-Li-ion energy) are used on the sizing step. Through this study, we could propose an optimal solution (masses, volumes, costs...) consisting of battery and supercapacitor. In the second part, we have followed the evolution of capacity and the internal resistance losses of high power and high energy batteries type in, respectively, single-source and hybrid configurations. For this study, a test bench, developed for cycling and characterization of storage systems, was used. The results obtained provide the opportunity to choose Li-ion battery technology that could be the most interesting for the supply of electric vehiclesVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year
International audienceMeridional and vertical distributions of several biogeochemical parameters were studied along a section in the southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer 2008 of the International Polar Year to characterize the biogeochemical provinces and to assess the seasonal net diatom production. Based on analyses of macro-nutrients, ammonium (NH4), chlorophyll a, (Chl a), phaeopigments, biogenic silica (BSi), particulate inorganic carbon (PIC), and particulate organic carbon and nitrogen (POC and PON, respectively), four biogeochemical domains were distinguished along the section: the subtropical Atlantic, the confluence zone of the subtropical and subantarctic domains, the Polar Frontal Zone (PFZ) in the Antarctic Circumpolar Current (ACC), and the north-eastern branch of the Weddell Gyre. The subtropical region displayed extremely low nutrient concentrations featuring oligotrophic conditions, and sub-surface maxima of Chl a and phaeopigments never exceeded 0.5 ”g Lâ1 and 0.25 ”g Lâ1, respectively. The anticyclonic and cyclonic eddies crossed in the Cape Basin were characterized by a deepening and a rise, respectively, of the nutrients isoclines. The confluence zone of the subtropical domain and the northern side of the ACC within the subantarctic domain displayed remnant nitrate and phosphate levels, whereas silicate concentrations kept to extremely low levels. In this area, Chl a level of 0.4-0.5 ”g Lâ1 distributed homogenously within the mixed layer, and POC and PON accumulated to values up to 10 ”M and 1.5 ”M, respectively, indicative of biomass accumulation along the confluence zone during the late productive period. In the ACC domain, the Polar Frontal Zone was marked by a post-bloom of diatoms that extended beyond the Polar Front (PF) during this late summer condition, as primarily evidenced by the massive depletion of silicic acid in the surface waters. The accumulation of NH4 to values up to 1.25 ”M at 100 m depth centred on the PF and the accumulation of BSi up to 0.5 ”M in the surface waters of the central part of the PFZ also featured a late stage of the seasonal diatom bloom. The silica daily net production rate based on the seasonal depletion of silicic acid was estimated to be 11.9 ± 6.5 mmol mâ2 dâ1 in the domain of the vast diatom post-bloom, agreeing well with the previously recorded values in this province. The Weddell Gyre occasionally displayed relative surface depletion of silicic acid, suggesting a late stage of a relatively minor diatom bloom possibly driven by iceberg drifting releases of iron. In this domain the estimated range of silica daily net production rate (e.g. 21.1 ± 8.8 mmol mâ2 dâ1) is consistent with previous studies, but was not significantly higher than that in the Polar Front region
Modeling and Control of the Modular Multilevel Converter connected to an inductive DC source using Energetic Macroscopic Representation
The use of DC transmission is particularly advantageous for long-distance transmission and interconnection of asynchronous AC networks. Several converter topologies can be used for HVDC. Multilevel Modular Converters (MMCs) are the most favored given their technological advantages over other converters topologies. Due to their industrial maturity, they have become essential for all AC / DC conversion. So far, they have always been studied with a voltage source on DC side. However, when the converter is equipped with DC breaker, a series inductor is associated to limit current variations. This has consequences in term of modeling and control determination. This article aims to propose a modification of the control law in order to take into account this inductor. To facilitate the control organization, the Energetic Macroscopic Representation (EMR) is used
Full State Regulation of the Modular Multilevel DC converter (M2DC) achieving minimization of circulating currents
The M2DC exploits the interleaving between the three legs of an MMC to realize a promising uninsulated DC/DC converter to interconnect HVDC grids. This paper details a current and energies decoupled model of the M2DC. The major idea proposed in this paper is focused on the full energy control generating optimal current references to minimize the internal currents magnitude. The energy sum and difference models are fully detailled. Both current and energy control loops are based on the model inversion principle in order to control all the state variables. The proposed control is based a dynamic control developed with the model inversion principle associated on an optimization of the current magnitude deduced from a quasi static analysis. All dynamics of the system are then explicitly controlled, which guarantee a good dynamic behavior during the transient. Therefore, current and energy controls are presented in details. Simulation results show the dynamic behavior of the converter for various operating points
ControÌle du Convertisseur Modulaire Multiniveaux connecteÌ aÌ une source DC inductive
L'utilisation de la transmission DC est particulieÌrement avantageuse pour la transmission aÌ longue distance et l'interconnexion des reÌseaux AC asynchrones. Plusieurs topologies de convertisseur peuvent eÌtre utiliseÌes pour le HVDC. Les convertisseurs modulaires multiniveaux (MMC) sont les plus favoriseÌs eÌtant donneÌ leurs avantages technologiques par rapport aux autres topologies de convertisseurs. Du fait de leur maturiteÌ industrielle, ils se sont imposeÌs maintenant pour tous les convertisseurs AC/DC aÌ transistors de forte puissance. Jusqu'ici, ils ont toujours eÌteÌ eÌtudieÌs avec une source de tension coÌteÌ DC. Or, lorsqu'ils sont eÌquipeÌs de DC breaker, on associe une inductance en seÌrie pour limiter les variations de courant. Ceci a des conseÌquences en terme de modeÌlisation puis de deÌtermination de la commande. Cet article a pour objectif de proposer une modification de commande afin de prendre en compte cette inductance
Quantifying sediment mass redistribution from joint time-lapse gravimetry and photogrammetry surveys
The accurate quantification of sediment mass redistribution is central to the study of surface processes, yet it remains a challenging task. Here we test a new combination of terrestrial gravity and drone photogrammetry methods to quantify sediment mass redistribution over a 1âkm2 area. Gravity and photogrammetry are complementary methods. Indeed, gravity changes are sensitive to mass changes and to their location. Thus, by using photogrammetry data to constrain this location, the sediment mass can be properly estimated from the gravity data. We carried out three joint gravimetryâphotogrammetry surveys, once a year in 2015, 2016 and 2017, over a 1âkm^2 area in southern Taiwan, featuring both a wide meander of the Laonong River and a slow landslide. We first removed the gravity changes from non-sediment effects, such as tides, groundwater, surface displacements and air pressure variations. Then, we inverted the density of the sediment with an attempt to distinguish the density of the landslide from the density of the river sediments. We eventually estimate an average loss of 3.7â\ub1â0.4â
7â10^9âkg of sediment from 2015 to 2017 mostly due to the slow landslide. Although the gravity devices used in this study are expensive and need week-long surveys, new instrumentation currently being developed will enable dense and continuous measurements at lower cost, making the method that has been developed and tested in this study well-suited for the estimation of erosion, sediment transfer and deposition in landscapes
A Simple Carrier-Based Modulation for the SVM of the Matrix Converter
Today, industry has not fully embraced the matrix converter solution. One important reason is its high control complexity. It is therefore relevant to propose a simpler but efficient modulation scheme, similar as three phase voltage source inverter modulators with the well-known symmetrical carrier-based ones. The modulation presented in this paper is equivalent to a particular space vector modulation (SVM) and takes into account harmonics and unbalanced input voltages, with the same maximum voltage transfer ratio (86%). The aim of this work is to propose a simple and general pulse width-modulation method using carrier-based modulator for an easier matrix converter control. Furthermore, a simple duty cycle calculation method is used, based on a virtual matrix converter. Finally, simulations and experimentations are presented to validate this simple, original and efficient modulation concept equivalent to matrix converter SVM.TRavaux de thÚses financé par le pole MEDEE, La région Nord pas de calais et STIE (Schneider Toshiba Inverter Europe
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