86,720 research outputs found
Synthèse d'un régulateur de vitesse à gains variables dans une structure DTC.
No full text73 f. : ill. ; 30 cm. (+ CD-Rom)Le travail effectué dans le cadre de ce mémoire propose une structure DTC dans laquelle la consigne du couple électromagnétique est asservie à la vitesse de rotation de la machine. Ainsi après un bref rappel des équations de la machine asynchrone dans le repère de Park, nous allons procéder à quelques tests en simulation pour vérifier le comportement de la machine sous alimentation sinusoïdale. En second lieu, nous allons aborder la modélisation du système d’alimentation par convertisseur statique, pour ensuite exposer théoriquement les principes généraux du contrôle direct du couple appliqués à une machine asynchrone triphasé. L’examen des résultats des simulations révèle de hautes performances dynamiques, lors de l’établissement du flux statorique et du couple électromagnétique, et un bon suivi de consigne en régime permanent. De plus, la structure de commande ne nécessite aucune information sur la vitesse de rotation de la machine, ce qui rend la stratégie de contrôle souple et fiable. La dernière partie de notre travail, nous avons envisagé de générer le couple de référence de la structure DTC via, un régulateur de vitesse à gains variables. Ainsi, nous avons mis en œuvre deux structures de régulation de la vitesse de rotation de la machine. La première est basée sur un régulateur PI classique, la seconde utilise un PI à gains variables. L’analyse comparative des résultats obtenus avec les deux régulateurs montre que le seconde est caractérisé par une réponse en vitesse sans dépassement, contrairement au PI classique. De plus, la boucle de vitesse ainsi formée hérite de la haute dynamique de la structure DTC du départ.
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Polycyclic aromatic hydrocarbon degradation and biosurfactant production by a newly isolated Pseudomonas sp. strain from used motor oil-contaminated soil
No full textThe aim of this study was to isolate and characterize a newly isolated bacterium, designated strain W10, a polycyclic aromatic hydrocarbon (PAHs) degrader and biosurfactant producer, belonged to Pseudomonas genus and closely related to Pseudomonas aeruginosa, with the 16 rRNA gene sequence similarity of 99.1%. Based on GC-MS analyses, it degraded around 80% of phenanthrene, used as the sole carbon and energy source, at an initial concentration of 200 mg l−1, after 30 days of incubation at 37 °C and 180 rpm, reducing the surface tension (ST) from 56.1 to 42 mN m−1 after 4 days of incubation. Furthermore, strain W10 utilized about 10%, 20%, 90%, and 99% of hexadecane (C16), pyrene, fluoranthene, and crude oil, respectively, after 30 days of incubation at 37 °C and 180 rpm. During the growth of strain W10 on phenanthrene and fluoranthene, some metabolites were identified, supporting the biodegradation pathways of the two PAHs. Interestingly, strain W10 showed also a significant potential to produce surface-active agents reducing the surface tension to 32 mN m−1 and reaching a production around 2 g l−1 after 48 h of incubation, in the presence of olive oil (1%,v/v) as substrate, at 37 °C and 180 rpm. Its biosurfactant, namely BSW10, showed an interesting emulsification activity and a high stability over a wide range of salinity (0–150 g l−1), temperature (0–100 °C), pH (2–12) and thus a promising abilities in used motor oil and crude oil removal from contaminated soils. Overall, these results provide evidence that strain W10 and its biosurfactant (BSW10) could be potential candidates for further bioremediation applications
Biodegradation of malodorous thiols by a Brevibacillus sp. strain isolated from a Tunisian phosphate factory
No full textHydrogen sulfide (H2S) and thiols (RSH) generated by the phosphate industry cause harmful effects on human health and quality of life. The present study aims to investigate and evaluate a bacterial strain CAT37 isolated from gas-washing wastewaters in terms of its properties and ability to degrade malodorous thiols. Gas-washing wastewater samples were submitted to physicochemical analyses and used for the isolation of thiol-degrading bacteria. The results from gas chromatography-mass spectrometry (GC-MS) analysis revealed that the isolated strain CAT37 was able to oxidize ~99% of each thiol, decanethiol and dodecanethiol used as sole carbon and energy sources after 30 days of incubation at 37° C. The strain CAT37 displayed a biodegradative potential on several thiols known by their toxicity and odors. The results from phylogenetic and phenotypic analysis revealed that the CAT37 isolate belonged to the genus Brevibacillus, showing the highest sequence similarity to Brevibacillus agri. Overall, the results indicated that the strain CAT37 exhibited a number of attractive biodegradation abilities against thiols and could be considered a promising candidate for industrial application in future thiol biodeodorization strategies
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
Mapping the Discipline of the Olympic Games An Author-Cocitation Analysis
No full textThe authors conducted an author cocitation analysis on prominent authors writing about the Olympics during the 1990s. Author cocitation is an established bibliometric technique that can be used to measure the relative similarities of topics written about by the cited authors. This enables a visual representation of the “intellectual space” of the discipline, in this case the Olympics, to be created for the period under review. So core and peripheral research areas are identified, along with their major contributors. The representation appears as a two-dimensional cluster-enhanced map. Subject expertise was then applied to the results to place labels on the generated clusters of authors and their topics
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