571 resultados para tall
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Dissertação de Mestrado, Engenharia Zootécnica, 18 de Julho de 2016, Universidade dos Açores.
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This work presents an application of optical fiber sensors based on Bragg gratings integrated to a transtibial prosthesis tube manufactured with a polymeric composite systrem of epoxy resin reinforced with glass fiber. The main objective of this study is to characterize the sensors applied to the gait cycle and changes in the gravity center of a transtibial amputee, trough the analysis of deformation and strengh of the transtibial prosthesis tube. For this investigation it is produced a tube of the composite material described above using the molding method of resin transfer (RTM) with four optical sensors. The prosthesis in which the original tube is replaced is classified as endoskeletal, has vacuum fitting, aluminium conector tube and carbon fiber foot cushioning. The volunteer for the tests was a man of 41 years old, 1.65 meters tall, 72 kilograms and left-handed. His amputation occurred due to trauma (surgical section is in the medial level, and was made below the left lower limb knee). He has been a transtibial prosthesis user for two years and eight months. The characterization of the optical sensors and analysis of mechanical deformation and tube resistance occurred through the gait cycle and the variation of the center of gravity of the body by the following tests: stand up, support leg without the prosthesis, support in the leg with the prosthesis, walk forward and walk backward. Besides the characterization of optical sensors during the gait cycle and the variation of the gravity center in a transtibial amputated, the results also showed a high degree of integration of the sensors in the composite and a high mechanical strength of the material.
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High volume compost incorporation can reduce runoff from compacted soils but its use also associated with elevated N and P concentrations in runoff making it difficult to assess if this practice will reduce nutrient loading of surface waters. Additionally, little is known about how this practice will effect leguminous species establishment in lawns as means to reduce long term fertilizer use. When 5 cm of compost was incorporated into soil a reduction in runoff of 40 and 59% was needed for N and P losses from a tall fescue + microclover lawn to be equivalent to a non-compost amended soil supporting a well fertilized tall fescue lawn. Use of compost as a soil amendment resulted in quicker lawn establishment and darker color, when compared to non-amended soil receiving a mineral fertilizer. Biosolid composts containing high amounts ammonium severely reduce the establishment of clover in tall fescue + micrclover seed mixture.
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Management of coconut ( Cocos nucifera ) lethal yellowing disease (CLYD), which has killed about eight million coconut trees in Mozambique, has proved challenging. The objective of this study was to investigate the impact of farming practices and related history, on the CLYD incidence in Mozambique. The methodology included a socioeconomic questionnaire to the households and direct observations on the palm farms. The collected data were analysed using logistic regression. Five out of 11 explanatory variables tested, namely farm age, availability of other palm species on the coconut farm, type of coconut varieties grown, root cut practices, and intercropping had a significant (P< 0.05) effect on CLYD incidence. Coconut farms <10 years had higher odds of higher disease incidence compared to the farms between 10 to 40 years old. The presence of other palm species in the coconut farms had two times higher odds of having higher disease incidence levels compared to farms without other palm species. Tall coconut varieties were likely to be more tolerant to CLYD compared to dwarf varieties. Coconut farms with some kind of intercropping had two times higher odds of having higher disease incidence levels compared to pure stands. The practice of cutting coconut roots had three times higher odds of having high disease incidence levels compared to non-practicing farms. Farm age, availability of other palm species on the coconut farm, type of coconut varieties grown, root cut practices and intercropping need to be considered for integrated CLYD management.
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En este artículo se presenta a DeBuPa (Detección Búsqueda Pateo) un humanoide de tamaño pequeño (38 cm de alto) construido con las piezas del kit Bioloid. Del kit se ha excluido la tarjeta CM-510 para sustituirla por la tarjeta controladora Arbotix, que será la que controle los 16 motores Dynamixel Ax-12+ (para mover al robot) y 2 servomotores analógicos (para mover la cámara). Además se ha agregado un mini computador Raspberry Pi, con su cámara, para que el robot pueda detectar y seguir la pelota de forma autónoma. Todos estos componentes deben ser coordinados para que se logre cumplir la tarea de detectar, seguir y patear la pelota. Por ello se hace necesaria la comunicación entre la Arbotix y la Raspberry Pi. La herramienta empleada para ello es el framework ROS (Robot Operating System). En la Raspberry Pi se usa el lenguaje C++ y se ejecuta un solo programa encargado de captar la imagen de la cámara, filtrar y procesar para encontrar la pelota, tomar la decisión de la acción a ejecutar y hacer la petición a la Arbotix para que dé la orden a los motores de ejecutar el movimiento. Para captar la imagen de la cámara se ha utilizado la librería RasPiCam CV. Para filtrar y procesar la imagen se ha usado las librerías de OpenCV. La Arbotix, además de controlar los motores, se encarga de monitorizar que el robot se encuentre balanceado, para ello usa el sensor Gyro de Robotis. Si detecta un desbalance de un cierto tamaño puede saber si se ha caído y levantarse.
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Estudou-se a Camada Limite Noturna ? CLN sobre área de floresta tropical primária a nordeste do Estado do Amazonas, no Observatório Amazônico da Torre Alta ? OATA ou Amazon Tall Tower Observatory ? ATTO. Foi aplicada a metodologia disponível na literatura que permitiu a caracterização da CLN em três regimes turbulentos: 1º) de turbulência fraca, com velocidade média do vento baixa; 2º) de turbulência forte, com velocidade do vento alta e, 3º) turbulência intermitente e condições de não estacionariedade. Existem variações sazonais nos valores de ?c? e ao passar de um regime para outro. Foram investigadas algumas das principais características estatísticas das concentrações de CO2 ? ?c? de cada um dos regimes turbulentos. ?c? aumenta levemente com a elevação do valor de uma escala característica de velocidade turbulenta, VTKE, até um valor limiar, VL, a partir do qual tem-se um aumento súbito nos valores de ?c?. Esses resultados têm importantes consequências para a parametrização de grandezas meteorológicas na CLN e modelagem do escoamento atmosférico na interface floresta-atmosfera.
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En un modelo cognitivo, la estructura cognitiva asociada con un determinado concepto matemático incluye todas las imágenes mentales, representaciones visuales, experiencias e impresiones, así como propiedades y procesos asociados (que llamaremos concepto-imagen, siguiendo a Vinner, Tall y Dreyfus y “estructuras elaboradas” o “esquemas” según los científicos cognitivos) y ha ido emergiendo con el tiempo mediante experiencias de todos los tipos, cambiando a medida que el individuo recibe nuevos estímulos y madura e influyéndose por desviaciones, aparentemente triviales, de un entendimiento válido. A medida que este concepto-imagen se desarrolla, no resulta necesario que sea coherente en cada momento. Así, resulta posible que visiones conflictivas sean evocadas en tiempos diferentes, sin que el individuo sea consciente del conflicto, hasta que son evocadas simultáneamente. Su coincidencia o no con lo que podríamos llamar concepto-definición (la formulación convencional lingüística que demarca precisamente las fronteras de aplicación del concepto) es fuente de muchas disfunciones en el aprendizaje.
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76 p.
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Buildings and other infrastructures located in the coastal regions of the US have a higher level of wind vulnerability. Reducing the increasing property losses and causalities associated with severe windstorms has been the central research focus of the wind engineering community. The present wind engineering toolbox consists of building codes and standards, laboratory experiments, and field measurements. The American Society of Civil Engineers (ASCE) 7 standard provides wind loads only for buildings with common shapes. For complex cases it refers to physical modeling. Although this option can be economically viable for large projects, it is not cost-effective for low-rise residential houses. To circumvent these limitations, a numerical approach based on the techniques of Computational Fluid Dynamics (CFD) has been developed. The recent advance in computing technology and significant developments in turbulence modeling is making numerical evaluation of wind effects a more affordable approach. The present study targeted those cases that are not addressed by the standards. These include wind loads on complex roofs for low-rise buildings, aerodynamics of tall buildings, and effects of complex surrounding buildings. Among all the turbulence models investigated, the large eddy simulation (LES) model performed the best in predicting wind loads. The application of a spatially evolving time-dependent wind velocity field with the relevant turbulence structures at the inlet boundaries was found to be essential. All the results were compared and validated with experimental data. The study also revealed CFD’s unique flow visualization and aerodynamic data generation capabilities along with a better understanding of the complex three-dimensional aerodynamics of wind-structure interactions. With the proper modeling that realistically represents the actual turbulent atmospheric boundary layer flow, CFD can offer an economical alternative to the existing wind engineering tools. CFD’s easy accessibility is expected to transform the practice of structural design for wind, resulting in more wind-resilient and sustainable systems by encouraging optimal aerodynamic and sustainable structural/building design. Thus, this method will help ensure public safety and reduce economic losses due to wind perils.
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We analysed the use of microneedle-based electrodes to enhance electroporation of mouse testis with DNA vectors for production of transgenic mice. Different microneedle formats were developed and tested, and we ultimately used electrodes based on arrays of 500 μm tall microneedles. In a series of experiments involving injection of a DNA vector expressing Green Fluorescent Protein (GFP) and electroporation using microneedle electrodes and a commercially available voltage supply, we compared the performance of flat and microneedle electrodes by measuring GFP expression at various timepoints after electroporation. Our main finding, supported by both experimental and simulated data, is that needles significantly enhanced electroporation of testis.
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Combined media on aluminum sculpture. 115½" Tall, Jargomatique Series.
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Combined media on aluminum sculpture. 115½" Tall, Jargomatique Series.
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La recension des écrits scientifiques à laquelle nous avons procédé a souligné clairement de très hautes fréquences de redoublement chez les jeunes d’âge scolaire relevant des enseignements primaire et post-primaire, dans les ex-colonies françaises d’Afrique occidentale et centrale (Burkina-Faso, Sénégal, Gabon). Au Burkina Faso, le taux moyen de redoublement observé au post-primaire a été d’environ 30 % au cours du quinquennat 2007/2008 à 2012/2013. La région du Centre-Ouest est celle qui en a enregistré le taux le plus élevé (33,1 %) sur les treize régions administratives du pays au cours de la période mentionnée, ce qui a justifié son choix dans le cadre de cette étude. L’objectif général visait à déterminer, dans le microsystème qu’est l’école au post-primaire général public, les caractéristiques des représentations sociales (RS) et des modèles d’intervention éducative (MIE) valorisés chez des enseignants et des directions d’écoles qui sont en relation avec le redoublement d’élèves habitant la région ciblée. L’étude menée est quantitative et de type descriptif. Dans le cadre de celle-ci nous avons fait usage d’une démarche d’enquête par questionnaire auprès d’un échantillon de convenance, stratifié et pondéré constitué de 199 enseignantes et enseignants, incluant un membre du personnel de direction pour chacune des institutions de provenance des sujets (N = 14 directions). Le résultat majeur est spécifique aux enseignants titulaires du CAPES (diplôme pédagogique le plus élevé) qui travaillent dans les communes urbaines où les écoles présentent un seuil élevé de redoublement (21 % et plus). Il suggère des caractéristiques qui correspondent à des profils de valorisation élevés de la représentation positive du redoublement d’une part, et de celle de l’externalité des causes du phénomène, d’autre part. Les principales caractéristiques des MIE privilégiés par ces derniers rapportent, quant à elles, une valorisation moyenne ou faible du MIE 3 (hétérostructuration coactive) et concomitamment une valorisation élevée du MIE 4 (interstructuration cognitive). Cependant, les données recueillies auprès des directions d’écoles dont la taille sous-échantillonnale demeure restreinte n’ont permis qu’une interprétation limitée hors de laquelle notre discours s’avérerait hautement spéculatif. Les enseignants et les directions d’école pourront bénéficier de l’intégration des données issues de l’étude au plan de la formation continue. Ils pourront par conséquent questionner leurs pratiques pédagogiques et leurs attitudes au regard des causes et des effets réels du redoublement sur la réussite et la persévérance scolaire des jeunes au post-primaire. Cela dans un contexte, où la scolarisation de base obligatoire de 10 ans constitue un objectif visé à l’horizon 2025 par le gouvernement du Burkina Faso dans le cadre de la réforme éducative engagée depuis 2007.
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An important current problem in micrometeorology is the characterization of turbulence in the roughness sublayer (RSL), where most of the measurements above tall forests are made. There, scalar turbulent fluctuations display significant departures from the predictions of Monin?Obukhov similarity theory (MOST). In this work, we analyze turbulence data of virtual temperature, carbon dioxide, and water vapor in the RSL above an Amazonian forest (with a canopy height of 40 m), measured at 39.4 and 81.6 m above the ground under unstable conditions. We found that dimensionless statistics related to the rate of dissipation of turbulence kinetic energy (TKE) and the scalar variance display significant departures from MOST as expected, whereas the vertical velocity variance follows MOST much more closely. Much better agreement between the dimensionless statistics with the Obukhov similarity variable, however, was found for the subset of measurements made at a low zenith angle Z, in the range 0° < |Z| < 20°. We conjecture that this improvement is due to the relationship between sunlight incidence and the ?activation?deactivation? of scalar sinks and sources vertically distributed in the forest. Finally, we evaluated the relaxation coefficient of relaxed eddy accumulation: it is also affected by zenith angle, with considerable improvement in the range 0° < |Z| < 20°, and its values fall within the range reported in the literature for the unstable surface layer. In general, our results indicate the possibility of better stability-derived flux estimates for low zenith angle ranges.
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2016