3,387 research outputs found
Design of a Switched Reluctance Motor Controller Applied to Electric Vehicles Traction.
Switched reluctance motors (SRM) are a suitable and cheaper alternative for current electric vehicle (EV) powertrain topologies due to low weight, high torque/size ratio and simple construction, without permanent magnets and a minimum amount of copper. The main setback that these motors encounter is the high torque ripple, mainly due to the highly nonlinear torque generation mechanism. Torque ripple leads to mechanical vibrations that require unnecessary wear in the mechanical powertrain. In conventional torque sharing function (TSF) control, the torque produced by the machine cannot follow the expected torque for an extended speed range, mostly due to the imposed demagnetization of the outgoing phase at high speeds, resulting in poor performance and causing a high torque ripple. The main goal of this work is to design and validate a new SRM control method suitable for EV propulsion. The proposed controller applies a feedback loop that improves the weakness of the conventional methods, keeping a fast dynamic response. The simulation results show that torque ripple can effectively be reduced for a high torque and speed range. The researched algorithm is developed using Matlab/Simulink, basing the validation on experiments with a 60kW SRM, 12/8 poles prototype designed using finite element methods (FEM)
Colonic metastases from small cell carcinoma of the lung presenting with an acute abdomen: A case report
AbstractIntroductionColonic metastases are rare, and usually secondary from malignant tumours of the stomach, breast, ovarian, cervix, kidney, lung, prostate, or skin. Around one third are asymptomatic or found only at autopsy.Case ReportA middle-aged male smoker, who had a small cell carcinoma of the lung diagnosed two years previously and treated with radiotherapy and chemotherapy, was admitted to the emergency room with intense abdominal pain and constipation. With the suspicion of an acute appendicitis he was submitted to surgery. At laparotomy he was found to have a normal appendix but two hard colonic lesions: a mobile one in the right colon and the other fixing the sigmoid colon to the sacrum. A right hemicolectomy and a sigmoid loop colostomy were performed. Pathology showed those lesions to be colonic metastases from small cell carcinoma of the lung.DiscussionColonic secondaries are most frequently diagnosed in patients who have had a known primary tumour, and may present with bowel obstruction, lower gastrointestinal haemorrhage, gastrointestinal fistula, or intestinal perforation. Presentation with acute abdomen is rare, and survival is usually limited.ConclusionColonic metastatic disease should be considered in any patient presenting with an acute abdomen and past history of lung malignancy
Perdas de solo, água e nutrientes em sistemas conservacionistas e convencionais de café no sul do estado do Espírito Santo.
The southern region Espirito Santo state is characterized by topographic strong wavy, with highly weathered soils and low fertility. Most of the land of family farms requires intensive soil use and, consequently, promotes soil loss, water and nutrients by erosion. Coffee conilon and grazing are the main systems of food production in the region. The aim of this study was to estimate, during the rainy season, soil loss and nutrient of areas under coffee cultivation systems under conservation (and agroforestry with management of soil cover) and conventional tillage (non-coverage soil). Collectors of soil and water were installed in 6 observation units, being 2 in conventional systems, 3 in conservationists systems and 1 in native forest that was used as a reference. Meteorological data were collected at the rainy season of 2009/2010. The soil and water losses estimated for the period, were higher (98 and 68%) in the conventional systems compared to conservation systems. Potassium was the nutrient that had higher losses in the systems (from 0.17 to 33 g/ha, respectively)
Sistema de percepção visual para veículos autónomos aéreos
Esta dissertação aborda o problema de detecção e desvio de obstáculos
"SAA- Sense And Avoid" em movimento para veículos aéreos. Em particular
apresenta contribuições tendo em vista a obtenção de soluções para
permitir a utilização de aeronaves não tripuladas em espaço aéreo não segregado
e para aplicações civis.
Estas contribuições caracterizam-se por: uma análise do problema de
SAA em \UAV's - Unmmaned Aerial Vehicles\ civis; a definição do conceito
e metodologia para o projecto deste tipo de sistemas; uma proposta de \ben-
chmarking\ para o sistema SAA caracterizando um conjunto de "datasets\
adequados para a validação de métodos de detecção; respectiva validação
experimental do processo e obtenção de "datasets"; a análise do estado da
arte para a detecção de \Dim point features\ ; o projecto de uma arquitectura
para uma solução de SAA incorporando a integração de compensação
de \ego motion" e respectiva validação para um "dataset" recolhido.
Tendo em vista a análise comparativa de diferentes métodos bem como
a validação de soluções foi proposta a recolha de um conjunto de \datasets"
de informação sensorial e de navegação. Para os mesmos foram definidos
um conjunto de experiências e cenários experimentais.
Foi projectado e implementado um setup experimental para a recolha
dos \datasets" e realizadas experiências de recolha recorrendo a aeronaves
tripuladas. O setup desenvolvido incorpora um sistema inercial de alta
precisão, duas câmaras digitais sincronizadas (possibilitando análise de informa
formação stereo) e um receptor GPS. As aeronaves alvo transportam um
receptor GPS com logger incorporado permitindo a correlação espacial dos
resultados de detecção.
Com este sistema foram recolhidos dados referentes a cenários de aproximação com diferentes trajectórias e condições ambientais bem como incorporando
movimento do dispositivo detector.
O método proposto foi validado para os datasets recolhidos tendo-se
verificado, numa análise preliminar, a detecção do obstáculo (avião ultraleve)
em todas as frames para uma distância inferior a 3 km com taxas de
sucesso na ordem dos 95% para distâncias entre os 3 e os 4 km.
Os resultados apresentados permitem validar a arquitectura proposta
para a solução do problema de SAA em veículos aéreos autónomos e abrem
perspectivas muito promissoras para desenvolvimento futuro com forte impacto
técnico-científico bem como sócio-economico. A incorporação de informa
formação de \ego motion" permite fornecer um forte incremento em termos
de desempenho.This thesis addresses the problem of perception for detection and avoidance
(\SAA - Sense And Avoid") of obstacles during the movement of unmanned
aircraft. It presents speci c contributions to the search of solutions that
allow the use of unmanned aerial vehicle (UAV - Unmmaned Aerial Vehicle)
in a non-segregated air space for non-military purposes. These contributions
are characterized by: the analysis of the SAA problem in civilian UAV's ;
the de nition of the concept and corresponding methodology for the project
of such systems; a benchmarking proposal for the SAA system based upon a
group of adequate datasets for the validation of detection methods; experimental
validation of the process itself along with the collection of datasets;
the analysis of the state of the art in \Dim point features" detection; the
design of an architecture for an SAA solution that incorporates the integration
of ego motion compensation as well as the corresponding validation for
a collected dataset. Since it is intended to compare di erent methods as
well as validating their respective solutions, the gathering of sensorial and
navigation information datasets has been proposed. A set of experiences and
experimental scenarios have been established. To obtain the datasets, an experimental
setup was designed and implemented along with data gathering
actions using a conventional airplane. The developed setup includes a highly
accurate inertial navigation system, two synchronized digital cameras (allowing
the analysis of stereo information) and a GPS reception device. The
target airplanes carry GPS devices with data logger that will provide the necessary
spatial correlation of the detection results. With this system it was
possible to collect data from approximation scenarios with di erent trajectories
and environmental conditions along with movement of the detection
device. The presented method was validated for the collected datasets and a preliminary analysis showed that the obstacle detection (glider aircraft) in
every frame was achieved for a distance lesser than 3 Km, with success rates
of 95% for distances raging from 3 to 4 Km. The presented results con rm
the proposed architecture for the solution of the SAA problem in UAV's and
opens a new set of promising perspectives in future developments with an
important contribution in scienti c and technological as well as social and
economical contexts. The inclusion of ego motion information resulted in
increased performance of the method
Sinergia entre o controle químico e a atmosfera modificada com ozônio para o manejo do gorgulho do milho
Monografia (graduação)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2014.O milho é atacado por um grande número de pragas, a exemplo de Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Esse trabalho objetivou testar se existe sinergia entre o uso simultâneo do controle químico com a atmosfera modificada com ozônio (O3) no manejo de S. zeamais e se o tratamento que resulta em controle efetivo da praga não altera os atributos fisiológicos da semente. Para tal, foram realizados ensaios preliminares visando estimar as CLs 50 e 90 da deltametrina (Decis® 25CE) e da azadiractina (AzaMax®) e os TLs 50 e 90 do O3. Para estimativa das CLs 50 e 90 de azadiractina e deltametrina e TLs 50 e 90, foram empregados 10 adultos de S. zeamais e 20 g de sementes de milho. Foram testadas as concentrações 1,00%, 2,91%, 4,76%, 9,09% e 33,33% de azadiractina (Aza), 0,1%, 0,3%, 0,5%, 1,00% e 2,91% de deltametrina (Delt) e os tempos 30, 40, 50, 60 e 70 minutos de exposição ao O3, além das testemunhas (água destilada para CLs 50 e 90 e oxigênio para TLs 50 e 90). Os valores obtidos foram usados em ensaios subsequentes cujos tratamentos foram: 1) CL90 Aza; 2) CL90 Delt; 3) TL90 O3; 4) CL50 Aza + TL50 O3; 5) CL50 da Delt + TL50 O3; 6) testemunha O3 (aeração com O2); 7) testemunha dos inseticidas (água). A mortalidade dos insetos foi avaliada imediatamente e 48 h após a ozonização. Em seguida, as sementes foram submetidas a testes de germinação, condutividade elétrica e tetrazólio. A associação entre a CL50 dos inseticidas e o TL50 do ozônio não resultou em sinergia e proporcionou mortalidade inferior à verificada na CL90 dos inseticidas. As CL90s da azadiractina (12,63% v/v) e da deltametrina (5,01% v/v) causaram mortalidade efetiva e não alteraram os atributos que garantem a qualidade das sementes de milho
Underwater Localization System Combining iUSBL with Dynamic SBL in ¡VAMOS! Trials
Emerging opportunities in the exploration of inland water bodies, such as underwater mining of flooded open pit mines, require accurate real-time positioning of multiple underwater assets. In the mining operation scenarios, operational requirements deny the application of standard acoustic positioning techniques, posing additional challenges to the localization problem. This paper presents a novel underwater localization solution, implemented for the ¡VAMOS! project, based on the combination of raw measurements from a short baseline (SBL) array and an inverted ultrashort baseline (iUSBL). An extended Kalman filter (EKF), fusing IMU raw measurements, pressure observations, SBL ranges, and USBL directional angles, estimates the localization of an underwater mining vehicle in 6DOF. Sensor bias and the speed of sound in the water are estimated indirectly by the filter. Moreover, in order to discard acoustic outliers, due to multipath reflections in such a confined and cluttered space, a data association layer and a dynamic SBL master selection heuristic were implemented. To demonstrate the advantage of this new technique, results obtained in the field, during the ¡VAMOS! underwater mining field trials, are presented and discussed.This work was funded by the ¡VAMOS! project funded by the European Commission under the H2020 EU Framework Programme for Research and by National Funds through the Portuguese funding agency, FCT (Fundação para a Ciência e a Tecnologia), within project UIDB/50014/2020 and TEC4SEA - Modular Platform for Research, Test and Validation of Technologies supporting a Sustainable Blue Economy from National Roadmap for Research Infrastructures of Strategic Interest, NORTE-01-0145-FEDER-022097- PINFRA/22097/2016.info:eu-repo/semantics/publishedVersio
ROAZ and ROAZ II Autonomous Surface Vehicle Design and Implementation
International Lifesaving Congress 2007, La Coruna, Spain, December, 2007The design and implementation of the ROAZ and
ROAZ II autonomous surface vehicles (ASV) is presented. These
systems were developed at Autonomous Systems Lab, ISEP/IPP –
Instituto Superior de Engenharia do Porto under a research
program in marine robotics. With multiple applications either in
river and estuarine environments or in the sea, the system
applications in search and rescue operations are addressed and
were taken in consideration for the overall system design.
Mechanical design issues are discussed. Hardware, software
and implementation status are described along with the control
and navigation system architecture. The real time vision
processing system is described and results are presented in
operational scenario
O Artigo 135 do Código Tributário Nacional e a Responsabilidade Tributária dos Diretores de Pessoa Jurídica
Uma nova emoção vem por aí: as estratégias de lançamento da telenovela na era da convergência
This research stems from the investigation of the TV promos by Rede Globo for the launch of
its telenovelas, having as a backdrop the scenario of communicational changes provided by the
integration between the multiple media. The study begins with a theoretical path about this
transformation context provided by the culture of media convergence and how it plays a
fundamental role in the new relationship between Rede Globo, its usual audience and digital
users. In sequence, we developed the construction of the TV schedule and an interval within a
channel, thus introducing the study of the main concepts and the categorization about the object
of the research, the TV promos. We complement and end the second chapter with a study about
the broadcasting design today and how its elements can demonstrate to the public the
integration between television and the internet. In the third part, the research methodology is
presented, as well as we demonstrate the results obtained through the analysis of the TV promos
for Flor do Caribe – Edição Especial, a telenovela aired between 2020 and 2021 at 6 p.m. on
Rede Globo. Our analysis covered two aspects: the constitutive aspects of the narrative and
visual format of the TV promos and the form of disclosure to the public both on TV and in the
digital platforms and social networks of the Rede Globo on the internet.Esta pesquisa decorre da investigação sobre as chamadas veiculadas pela Rede Globo para o
lançamento de suas telenovelas, tendo como pano de fundo o cenário de mudanças
comunicacionais proporcionado pela integração entre os múltiplos meios midiáticos. O estudo
inicia-se por um percurso teórico sobre essa transformação contextualizada pela cultura da
convergência midiática e como ela desempenha um papel fundamental na nova forma de
relacionamento entre a Rede Globo, a sua audiência costumeira e os usuários digitais.
Desenvolvemos a construção da grade de programação e de um intervalo dentro de uma
emissora de TV, introduzindo assim o estudo dos principais conceitos e a categorização acerca
do objeto da pesquisa, as chamadas de programação. Complementamos com uma reflexão
acerca do papel do design televisual na atualidade e como seus elementos podem demonstrar
ao público a integração entre televisão e internet. Na terceira parte, apresentamos a metodologia
de pesquisa, assim como demonstramos os resultados obtidos por meio da análise das chamadas
de lançamento de Flor do Caribe - Edição Especial, telenovela exibida entre 2020 e 2021 no
horário das seis da Rede Globo. Nossa análise abrange dois elementos: os aspectos constitutivos
do formato narrativo e visual das chamadas e a forma de divulgação junto ao público na
televisão aberta e no ambiente digital, por meio das plataformas e redes sociais da emissora na
internet
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