FPGA field oriented control of an axial flux motor-in-wheel

This paper presents the design and the prototype implementation of a three-phase power inverter developed to drive a motor-in-wheel. The control system is implemented in a FPGA (Field Programmable Gate Array) device. The paper describes the Field Oriented Control (FOC) algorithm and the Space Vector Modulation (SVM) technique that were implemented. The control platform uses a Spartan-3E FPGA board, programmed with Verilog language. Simulation and experimental results are presented to validate the developed system operation under different load conditions. Finally are presented conclusions based on the experimental results.

Field oriented control of an axial flux permanent magnet synchronous motor for traction solutions

Electric Vehicles (EVs) are increasingly used nowadays, and different powertrain solutions can be adopted. This paper describes the control system of an axial flux Permanent Magnet Synchronous Motor (PMSM) for EVs powertrain. It is described the implemented Field Oriented Control (FOC) algorithm and the Space Vector Modulation (SVM) technique. Also, the mathematical model of the PMSM is presented. Both, simulation and experimental, results with different types of mechanical load are presented. The experimental results were obtained using a laboratory test bench. The obtained results are discussed.

Algorithms and computational tools for metabolic flux analysis

PhD thesis in Biomedical Engineering

Chronic Stress Improves NO- and Ca2+ Flux-Dependent Vascular Function: A Pharmacological Study

Background: Stress is associated with cardiovascular diseases. Objective: This study aimed at assessing whether chronic stress induces vascular alterations, and whether these modulations are nitric oxide (NO) and Ca2+ dependent. Methods: Wistar rats, 30 days of age, were separated into 2 groups: control (C) and Stress (St). Chronic stress consisted of immobilization for 1 hour/day, 5 days/week, 15 weeks. Systolic blood pressure was assessed. Vascular studies on aortic rings were performed. Concentration-effect curves were built for noradrenaline, in the presence of L-NAME or prazosin, acetylcholine, sodium nitroprusside and KCl. In addition, Ca2+ flux was also evaluated. Results: Chronic stress induced hypertension, decreased the vascular response to KCl and to noradrenaline, and increased the vascular response to acetylcholine. L-NAME blunted the difference observed in noradrenaline curves. Furthermore, contractile response to Ca2+ was decreased in the aorta of stressed rats. Conclusion: Our data suggest that the vascular response to chronic stress is an adaptation to its deleterious effects, such as hypertension. In addition, this adaptation is NO- and Ca2+-dependent. These data help to clarify the contribution of stress to cardiovascular abnormalities. However, further studies are necessary to better elucidate the mechanisms involved in the cardiovascular dysfunction associated with stressors. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)

Enrutament i control de flux en xarxes híbrides satèl·lit-terrestre

Les xarxes híbrides satèl·lit-terrestre ofereixen connectivitat a zones remotes i aïllades i permeten resoldre nombrosos problemes de comunicacions. No obstant, presenten diversos reptes, ja que realitzen la comunicació per un canal mòbil terrestre i un canal satèl·lit contigu. Un d'aquests reptes és trobar mecanismes per realitzar eficientment l'enrutament i el control de flux, de manera conjunta. L'objectiu d'aquest projecte és simular i estudiar algorismes existents que resolguin aquests problemes, així com proposar-ne de nous, mitjançant diverses tècniques d'optimització convexa. A partir de les simulacions realitzades en aquest estudi, s'han analitzat àmpliament els diversos problemes d'enrutament i control de flux, i s'han avaluat els resultats obtinguts i les prestacions dels algorismes emprats. En concret, s'han implementat de manera satisfactòria algorismes basats en el mètode de descomposició dual, el mètode de subgradient, el mètode de Newton i el mètode de la barrera logarítmica, entre d'altres, per tal de resoldre els problemes d'enrutament i control de flux plantejats.

Phylogeographical footprints of the Strait of Gibraltar and Quaternary climatic fluctuations in the western Mediterranean: a case study with the greater white-toothed shrew, Crocidura russula (Mammalia: Soricidae).

We used mitochondrial cyt b sequences to investigate the phylogenetic relationships of Crocidura russula (sensu lato) populations across the Strait of Gibraltar, western Europe, Maghreb, and the Mediterranean and Atlantic islands. This revealed very low genetic divergence between European and Moroccan populations. The application of a molecular clock previously calibrated for shrews suggested that the separation of European from Moroccan lineages occurred less than 60 000 bp, which is at least 5 million years (Myr) after the reopening of the Strait of Gibraltar. This means that an overwater dispersal event was responsible for the observed phylogeographical structure. In contrast, genetic analyses revealed that Moroccan populations were highly distinct from Tunisian ones. According to the molecular clock, these populations separated about 2.2 million years ago (Ma), a time marked by sharp alternations of dry and humid climates in the Maghreb. The populations of the Mediterranean islands Ibiza, Pantelleria, and Sardinia were founded from Tunisian populations by overwater dispersal. In conclusion, overwater dispersal across the Strait of Gibraltar, probably assisted by humans, is possible for small terrestrial vertebrates. Moreover, as in Europe, Quaternary climatic fluctuations had a major effect on the phylogeographical structure of the Maghreb biota.

Enhancement of autophagic flux after neonatal cerebral hypoxia-ischemia and its region-specific relationship to apoptotic mechanisms.

The multiplicity of cell death mechanisms induced by neonatal hypoxia-ischemia makes neuroprotective treatment against neonatal asphyxia more difficult to achieve. Whereas the roles of apoptosis and necrosis in such conditions have been studied intensively, the implication of autophagic cell death has only recently been considered. Here, we used the most clinically relevant rodent model of perinatal asphyxia to investigate the involvement of autophagy in hypoxic-ischemic brain injury. Seven-day-old rats underwent permanent ligation of the right common carotid artery, followed by 2 hours of hypoxia. This condition not only increased autophagosomal abundance (increase in microtubule-associated protein 1 light chain 3-11 level and punctuate labeling) but also lysosomal activities (cathepsin D, acid phosphatase, and beta-N-acetylhexosaminidase) in cortical and hippocampal CA3-damaged neurons at 6 and 24 hours, demonstrating an increase in the autophagic flux. In the cortex, this enhanced autophagy may be related to apoptosis since some neurons presenting a high level of autophagy also expressed apoptotic features, including cleaved caspase-3. On the other hand, enhanced autophagy in CA3 was associated with a more purely autophagic cell death phenotype. In striking contrast to CA3 neurons, those in CA1 presented only a minimal increase in autophagy but strong apoptotic characteristics. These results suggest a role of enhanced autophagy in delayed neuronal death after severe hypoxia-ischemia that is differentially linked to apoptosis according to the cerebral region.

On the analysis of travelling waves to a nonlinear flux limited reaction-diffusion equation

In this paper we study the existence and qualitative properties of travelling waves associated to a nonlinear flux limited partial differential equation coupled to a Fisher-Kolmogorov-Petrovskii-Piskunov type reaction term. We prove the existence and uniqueness of finite speed moving fronts of C2 classical regularity, but also the existence of discontinuous entropy travelling wave solutions.

Del Dreambox 7000S al Nokia 770 Internet Tablet : Port de VideoLan Client a Maeno per a la reproducció d'un flux mpeg2 per mitjà d'una xarxa sense fils

L'objectiu d'aquest projecte és connectar el sintonitzador de televisió per satèl·lit Dreambox 7000S amb el Nokia 770 Internet Tablet. El propòsit d'aquesta aplicació és utilitzar el Dreambox 7000S com una font de streaming mpeg2 i el Nokia 770 com a reproductor portàtil.

Ecologie industrielle de l'aluminium, flux de matières et d'énergie : réalités et enjeux du recyclage

Dans les dernières années du 20ème siècle, l'aluminium a fait l'objet de beaucoup de communications outrancières et divergentes cautionnées par des scientifiques et des organismes faisant autorité. En 1986, la société PECHINEY le décrète perpétuel tel le mouvement « L'aluminium est éternel. Il est recyclable indéfiniment sans que ses propriétés soient altérées », ce qui nous avait alors irrité. Peu de temps après, en 1990, une communication tout aussi outrancière et irritante d'une grande organisation environnementale, le World Wild Fund, décrète que « le recyclage de l'aluminium est la pire menace pour l'environnement. Il doit être abandonné ». C'est ensuite à partir de la fin des années 1990, l'explosion des publications relatives au développement durable, le bien mal nommé. Au développement, synonyme de croissance obligatoire, nous préférons société ou organisation humaine et à durable, mauvaise traduction de l'anglais « sustainable », nous préférons supportable : idéalement, nous aurions souhaité parler de société durable, mais, pour être compris de tous, nous nous sommes limités à parler dorénavant de développement supportable. Pour l'essentiel, ces publications reconnaissent les très graves défauts de la métallurgie extractive de l'aluminium à partir du minerai et aussi les mérites extraordinaires du recyclage de l'aluminium puisqu'il représente moins de 10% de la consommation d'énergie de la métallurgie extractive à partir du minerai (on verra que c'est aussi moins de 10% de la pollution et du capital). C'est précisément sur le recyclage que se fondent les campagnes de promotion de l'emballage boisson, en Suisse en particulier. Cependant, les données concernant le recyclage de l'aluminium publiées par l'industrie de l'aluminium reflètent seulement en partie ces mérites. Dans les années 1970, les taux de croissance de la production recyclée sont devenus plus élevés que ceux de la production électrolytique. Par contre, les taux de recyclage, établis à indicateur identique, sont unanimement tous médiocres comparativement à d'autres matériaux tels le cuivre et le fer. Composante de l'industrie de l'aluminium, le recyclage bénéficie d'une image favorable auprès du grand public, démontrant le succès des campagnes de communication. A l'inverse, à l'intérieur de l'industrie de l'aluminium, c'est une image dévalorisée. Les opinions émises par tous les acteurs, commerçants, techniciens, dirigeants, encore recueillies pendant ce travail, sont les suivantes : métier de chiffonnier, métier misérable, métier peu technique mais très difficile (un recycleur 15 d'aluminium n'a-t-il pas dit que son métier était un métier d'homme alors que celui du recycleur de cuivre était un jeu d'enfant). A notre avis ces opinions appartiennent à un passé révolu qu'elles retraduisent cependant fidèlement car le recyclage est aujourd'hui reconnu comme une contribution majeure au développement supportable de l'aluminium. C'est bien pour cette raison que, en 2000, l'industrie de l'aluminium mondiale a décidé d'abandonner le qualificatif « secondaire » jusque là utilisé pour désigner le métal recyclé. C'est en raison de toutes ces données discordantes et parfois contradictoires qu'a débuté ce travail encouragé par de nombreuses personnalités. Notre engagement a été incontestablement facilité par notre connaissance des savoirs indispensables (métallurgie, économie, statistiques) et surtout notre expérience acquise au cours d'une vie professionnelle menée à l'échelle mondiale dans (recherche et développement, production), pour (recherche, développement, marketing, stratégie) et autour (marketing, stratégie de produits connexes, les ferro-alliages, et concurrents, le fer) de l'industrie de l'aluminium. Notre objectif est de faire la vérité sur le recyclage de l'aluminium, un matériau qui a très largement contribué à faire le 20ème siècle, grâce à une revue critique embrassant tous les aspects de cette activité méconnue ; ainsi il n'y a pas d'histoire du recyclage de l'aluminium alors qu'il est plus que centenaire. Plus qu'une simple compilation, cette revue critique a été conduite comme une enquête scientifique, technique, économique, historique, socio-écologique faisant ressortir les faits principaux ayant marqué l'évolution du recyclage de l'aluminium. Elle conclut sur l'état réel du recyclage, qui se révèle globalement satisfaisant avec ses forces et ses faiblesses, et au-delà du recyclage sur l'adéquation de l'aluminium au développement supportable, adéquation largement insuffisante. C'est pourquoi, elle suggère les thèmes d'études intéressant tous ceux scientifiques, techniciens, historiens, économistes, juristes concernés par une industrie très représentative de notre monde en devenir, un monde où la place de l'aluminium dépendra de son aptitude à satisfaire les critères du développement supportable. ABSTRACT Owing to recycling, the aluminium industry's global energetic and environmental prints are much lower than its ore extractive metallurgy's ones. Likewise, recycling will allow the complete use of the expected avalanche of old scraps, consequently to the dramatic explosion of aluminium consumption since the 50's. The recycling state is characterized by: i) raw materials split in two groups :one, the new scrap, internal and prompt, proportional to semi-finished and finished products quantities, exhibits a fairly good and regular quality. The other, the old scrap, proportional to the finished products arrivïng at their end-of--life, about 22 years later on an average, exhibits a variable quality depending on the collect mode. ii) a poor recycling rate, near by that of steel. The aluminium industry generates too much new internal scrap and doesn't collect all the availa~e old scrap. About 50% of it is not recycled (when steel is recycling about 70% of the old scrap flow). iii) recycling techniques, all based on melting, are well handled in spite of aluminium atiiníty to oxygen and the practical impossibility to purify aluminium from any impurity. Sorting and first collect are critical issues before melting. iv) products and markets of recycled aluminium :New scraps have still been recycled in the production lines from where there are coming (closed loop). Old scraps, mainly those mixed, have been first recycled in different production lines (open loop) :steel deoxidation products followed during the 30's, with the development of the foundry alloys, by foundry pieces of which the main market is the automotive industry. During the 80's, the commercial development of the beverage can in North America has permitted the first old scrap recycling closed loop which is developing. v) an economy with low and erratic margins because the electrolytic aluminium quotation fixes scrap purchasing price and recycled aluminium selling price. vi) an industrial organisation historically based on the scrap group and the loop mode. New scrap is recycled either by the transformation industry itself or by the recycling industry, the remelter, old scrap by the refiner, the other component of the recycling industry. The big companies, the "majors" are often involved in the closed loop recycling and very seldom in the open loop one. To-day, aluminium industry's global energetic and environmental prints are too unbeara~ e and the sustainaЫe development criteria are not fully met. Critical issues for the aluminium industry are to better produce, to better consume and to better recycle in order to become a real sustainaЫe development industry. Specific issues to recycling are a very efficient recycling industry, a "sustainaЫe development" economy, a complete old scrap collect favouring the closed loop. Also, indirectly connected to the recycling, are a very efficient transformation industry generating much less new scrap and a finished products industry delivering only products fulfilling sustainaЫe development criteria.

The transcription factor PHR1 plays a key role in the regulation of sulfate shoot-to-root flux upon phosphate starvation in Arabidopsis.

Background: Sulfate and phosphate are both vital macronutrients required for plant growth and development. Despite evidence for interaction between sulfate and phosphate homeostasis, no transcriptional factor has yet been identified in higher plants that affects, at the gene expression and physiological levels, the response to both elements. This work was aimed at examining whether PHR1, a transcription factor previously shown to participate in the regulation of genes involved in phosphate homeostasis, also contributed to the regulation and activity of genes involved in sulfate inter-organ transport. Results: Among the genes implicated in sulfate transport in Arabidopsis thaliana, SULTR1;3 and SULTR3;4 showed up-regulation of transcripts in plants grown under phosphate-deficient conditions. The promoter of SULTR1;3 contains a motif that is potentially recognizable by PHR1. Using the phr1 mutant, we showed that SULTR1;3 up regulation following phosphate deficiency was dependent on PHR1. Furthermore, transcript up regulation was found in phosphate-deficient shoots of the phr1 mutant for SULTR2;1 and SULTR3;4, indicating that PHR1 played both a positive and negative role on the expression of genes encoding sulfate transporters. Importantly, both phr1 and sultr1;3 mutants displayed a reduction in their sulfate shoot-to-root transfer capacity compared to wild-type plants under phosphate-deficient conditions. Conclusions: This study reveals that PHR1 plays an important role in sulfate inter-organ transport, in particular on the regulation of the SULTR1;3 gene and its impact on shoot-to-root sulfate transport in phosphate-deficient plants. PHR1 thus contributes to the homeostasis of both sulfate and phosphate in plants under phosphate deficiency. Such a function is also conserved in Chlamydomonas reinhardtii via the PHR1 ortholog PSR1.

Anàlisi del flux de materials del sector de la fusta a Catalunya per l’any 2005

Anàlisi del flux de manterials que travessen el sector de la fusta a Catalunya durant l’any 2005 calculant els balanços de matèria i els indicadors derivats, de cara a avaluar la gestió dels boscos a Catalunya