The paper presents design solution and physical implementation of a system for examination of electro hydraulic steering based on OSPE 200 components. The implementation is based on synthesis of required hydraulic and structure parameters, presented in a previous paper. Now we present the interconnection of the digital control system and the closed-loop flow diagram. A formal description of embedded software is presented too, which supports operation of PI control algorithm in real-time. Identification is performed based on experimentally reported the transitional process by developing mathematical models. Presents the structure and capabilities of the models for identification, as well as procedures for their validation.

L’objectif du présent travail est l’analyse du fonctionnement des aménagements antiérosifs les plus répandus en Tunisie, les banquettes et les lacs collinaires. L’évaluation des banquettes a été basée sur leur caractérisation, le diagnostic de leur état, leur incidence sur le développement et la croissance de la culture de l’orge et leur impact sur certains paramètres physico-chimiques du sol. La reconstitution des apports hydriques, l’estimation des prélèvements pour l’irrigation et la détermination des apports solides moyens et exceptionnels ont été utilisés comme indicateurs pour l’évaluation des lacs collinaires. L’analyse diachronique a mis en évidence l’importance des cultures annuelles du périmètre aménagé en banquettes et la régression des espaces réservés aux terrains de parcours au cours du temps. Les résultats montrent que certaines banquettes ont été surdimensionnées tel que pour les écartements, les superficies des inter-ouvrages et leur longueur. Le diagnostic de l’état des ouvrages montre qu’une forte proportion des banquettes a été affectée par diverses formes de dégradation qui semblent être en rapport avec l’événement pluvieux exceptionnel de l’hiver 2003. L’évaluation des effets de l’aménagement en banquettes sur la production des céréales montre que la croissance, le développement végétatif et la production de matière sèche de la culture d’orge ont été significativement améliorés pour la zone située à proximité de l’ouvrage en comparaison avec la zone non aménagée. Après plus de trois décennies de la réalisation de l’aménagement, l’accroissement du rendement attribué à la mise en œuvre des banquettes a été évalué à 33% à proximité du bourrelet et à près de 10% en intégrant la superficie de l’ensemble de l’inter-banquette. Par ailleurs, l’aménagement en banquettes permet d’accroître la profondeur du sol, la teneur en matière organique, la capacité de rétention de l’eau, la fraction fine du sol et de réduire le taux de cailloux dans la zone limitrophe des ouvrages. Le taux de carbonates, le pH et la conductivité électrique semblent être non affectés par la mise en œuvre des banquettes. L’évaluation des prélèvements annuels, pour les besoins en eau d’irrigation, en moyenne durant la période de suivi, au niveau des lacs collinaires sur l’oued Fathiza I, l’oued Ras Rmal et l’oued Sned sont plus faibles que les apports effectifs indiquant une sous-utilisation de l’eau. Les apports moyens effectifs représentent entre 36% et 195% des apports estimés selon les ouvrages. Les apports solides moyens initialement estimés pour chacun des trois ouvrages ont été sous évalués se traduisant ainsi par une sédimentation prématurée. Les taux élevés de sédimentation risquent de compromettre la durée de vie des réservoirs. Les pertes de capacité, à la suite des précipitations exceptionnelles de l’hiver 2003, varient de 3,5% à 7,3% de la capacité initiale. Ces taux de sédimentation montrent l’impact des évènements paroxysmiques sur l’érosion au niveau des bassins versants de ces lacs collinaires. La spatialisation de la sédimentation à travers les cuvettes montre que l'essentiel du dépôt solide a lieu à l'amont des cuvettes.

Dažnio matavimo stendo sudarymas ir tyrimas. Magistro baigiamasis darbas elektronikos inžinerijos laipsniui. Vilniaus Gedimino technikos universitetas. Vilnius, 2014, 71 p., 31 iliustr., 3 lent., 36 bibl., 6 priedai. Sukurtas ir ištirtas dažnio matavimo stendas, atskleidžiantis skaitmeninių dažnio ir periodo matavimo būdų ypatumus. Stendas pakeis šiuo metu laboratoriniuose darbuose naudojamus pasenusius prietaisus. Stendą sudaro 3 užduodantys generatoriai, dažnio sintezatorius, dažniamatis ir sąsaja su asmeniniu kompiuteriu, bendrame korpuse. Matavimo rezultatams įvertinti sukurta specializuota programinė įranga. Atlikus stendo tyrimus įsitikinta, kad sukurtas dažniamačio stendas atitinka visus užduoties reikalavimus. / Creation and investigation of frequency counter. Master's thesis in electronics engineering degree. Vilnius Gediminas Technical University. Vilnius , 2014, 71 p., 31 pictures, 3 tables, 36 references, 6 extras. Frequency counter stand have been created and investigated. Stand will allow students to familiarize themselves with particularities of digital measurement methods of frequency and duration of the period. The new stand will replace old measurement devices that are used during laboratory works recently. The stand consists of frequency synthesizer, frequency counter, 3 different reference generators and interface to the computer packed in single case. Specialized software have been created to assess and treat measurements results. Testing results of the bench proved that created frequency counter stand meets all the requirements of the task.

Ingeniero Civil de Minas / Debido a los altos costos experimentados por Minera Michilla durante la explotación de la mina Estefanía por el método de cut & fill post room and pillar, dicha empresa se ve en la necesidad de buscar métodos alternativos técnicamente factibles a la realidad del yacimiento. Es así como se plantea la aplicación del método bench & fill en los sectores más profundos de la mina (D4 y ABW inferior). El método de Bench & Fill en estudio consiste en una variación del tradicional Cut & Fill, en donde la explotación de se hace por medio de banqueo y relleno. La secuencia de explotación sigue dos direcciones: siempre se realiza en retroceso dentro de un mismo nivel, y se efectúa de manera descendente dentro de un mismo sector. El diseño a ejecutar en el sector D4 de la mina subterránea se encuentra compuesto por 3 bloques, abarcando profundidades desde la cota 51.5 hasta la cota -31.5. El método considera dos tipos de cámaras, primaria y secundaria. Ambas cámaras poseen una altura de 15m, siendo el ancho de estas 7m y 9m respectivamente. Además se considera la presencia de pilares de 6m entre dos cámaras continuas y una losa de 8m de altura entre dos niveles para asegurar la estabilidad de las labores. Las galerías del sector poseen una sección de 7x5m. Tomando en cuenta los parámetros de diseño anteriormente planteados, se procede a generar un modelo computacional que permita estimar los costos directos asociados al método de explotación. Los costos se dividen dentro de ocho clases: costos de tronadura, perforación, fortificación, carguío, transporte, relleno, administración y servicios. Para determinar los costos asociados a cada una de las áreas mencionadas, se procede de la siguiente manera: - Determinar los principales insumos necesarios en los distintos trabajos. - Haciendo uso de la metodología Asarco para obtener los índices operacionales de los equipos, y tomando en cuenta los índices de costos operacionales de los equipos se obtiene el costo operacional de las distintas aéreas. - Considerando el tiempo de trabajo necesario para cumplir las labores se estima el costo de mano de obra asociado. - Sumando los tres costos mencionados, y tomando en cuenta los metros de preparación necesarios para extraer el sector en estudio se obtiene el costo mina del método. De acuerdo a la metodología plantead, se estima el costo mina para el bench & fill sin tomar en cuenta los costos distribuibles de otros departamentos. Es así como se obtiene un costo mina de 34,3 US$/ton asociados al método. Al tomar en cuenta el plan minero proporcionado, se obtiene un costo total de desarrollo para el sector de 18,46 [MUS$], siendo comparable de manera favorable con el cut & fill post room and pillar (46,5 [US$/ton] y 31,2 [MUS$] respectivamente). Es así como se concluye que el método de Bench & Fill resulta ser atractivo de acuerdo a los objetivos planteados, proporcionando menores costos que el actual Cut & Fill y a su vez mejorando la seguridad del personal presente en la mina.

Les ventilateurs ont connu des progrès technologiques considérables grâce à l'application de concepts physiologiques, à l'électronique, à l'informatique et la miniaturisation. Leurs conceptions et performances intrinsèques, en revanche, ont pu rester inégales sur certains points. L'objectif de ce travail a été d'évaluer sur un banc d'essai, avec un protocole, adapté aux problématiques soulevées en pratique clinique, tous les ventilateurs de réanimation, transport et de ventilation non invasive de façon rigoureuse et reproductible. Les résultats montrent que 1) l'erreur sur le volume réellement délivré est très fréquente et correspond facilement à 1ml/kg de volume supplémentaire ; le VT indiqué sur les ventilateurs est inférieur au VT réellement délivré ; 2) les performances des nouveaux ventilateurs ne présentent pas d'améliorations significatives par rapport aux meilleurs ventilateurs testés en 2000; les ventilateurs à turbine sont identiques ou proches des meilleurs ventilateurs conventionnels ; 3) les ventilateurs dédiés à la ventilation non invasive montrent de meilleures performances pour s'adapter à la présence de fuites ; 4) la ventilation par percussion intra-pulmonaire superposée à la ventilation conventionnelle peut réduire l'apport de l'humidification, influencer les volumes administrés et induire une pression expiratoire positive intrinsèque. Les tests sur banc montrent une grande hétérogénéité des performances. Une veille technologique semble indispensable pour évaluer tout nouveau ventilateur / The ventilators have markedly improved thanks to progress in respiratory physiology, in informatics and miniaturization. However, their intrinsic performances remain unequal. The aim was to evaluate ventilators performances on reproducible bench test studies adapted to clinical questions. Tests show that 1) the error of really delivered volume is approximately 1 ml/kg of additional volume; the tidal volume (VT) indicated on the ventilators was lower than the real delivered VT ; 2) Performances of new ventilators are comparable to the best ventilators tested in 2000 ; turbine ventilators are quite similar to best conventional ventilators ; 3) The ventilators dedicated to non invasive ventilation showed better performances to cope with leaks 4) The intrapulmonary percussive ventilation superimposed on conventional ventilation can reduce humidity, increase volumes and can generate intrinsic positive expiratory pressure. The bench tests showed a large heterogeneity of performances. A technological watch seems essential to evaluate all new ventilators

Há pouca disponibilidade de informações de perda localizada de carga sobre conexões utilizadas em microirrigação. Diante disso, objetivou-se desenvolver e validar uma bancada automatizada para ensaios e determinar experimentalmente as perdas localizadas provocadas por conexões utilizadas em sistemas de microirrigação. Desenvolveu-se uma bancada automatizada utilizando um circuito eletrônico microcontrolado que dispõe de funcionalidades para aquisição e condicionamento de sinais de sensores; controle de inversor de frequência e válvula proporcional; controle Proporcional-Integral-Derivativo (PID); e, comunicação Modbus RTU com outros dispositivos através de rede RS-485. O firmware implementado no microcontrolador foi desenvolvido na linguagem C, enquanto que a interface gráfica do usuário (GUI) foi desenvolvida em C#. A metodologia de ensaios foi elaborada combinando recomendações de normas técnicas internacionais. Os ensaios foram conduzidos sob pressão de entrada controlada em 150 kPa, sendo ensaiadas entre cinco e dez peças para cada modelo de conexão. As curvas relacionando vazão e perda localizada de carga foram construídas com, pelo menos, 15 valores de vazão, submetidos sob condição de incremento e decréscimo para incluir eventuais efeitos de histerese do sistema de medição. Foram coletados 30 pontos por condição de vazão, tendo sido realizado uma aquisição de 900 pontos por ensaio. Para cada modelo avaliado foram apresentados as seguintes informações: curva de perda localizada de carga em função de vazão, coeficiente de perda localizada de carga (KL) e comprimento equivalente (Leq). A bancada de ensaios automatizada permitiu a condução dos ensaios onde os sistemas de medição e controle operaram adequadamente, sendo capazes de atender a requisitos estabelecidos em normas técnicas. Os valores aproximados de KL se apresentaram entre 2,70 a 24,08. Em muitos dos casos, o coeficiente tendeu a uma constância após um número de Reynolds de 10000. Pôde-se verificar também a sensibilidade do coeficiente relacionada com a razão das seções internas nas conexões. Os expoentes da vazão assumem valores próximos do que é aplicado pela equação de Darcy-Weisbach (m=2). / Information about minor losses caused by fittings employed in microirrigation systems are hard to be found in literature. The objective of this research was to develop and validate an automated bench for determine experimentally minor losses caused by fittings commonly installed in microirrigation. An automated bench was developed using a microcontrolled electronic circuit that has functionalities for data acquisition and signal conditioning; control of variable frequency drive and proportional valve; Proportional-Integral-Derivative Control (PID); and, Modbus RTU communication with other devices through a RS-485 network. The firmware implemented for the microcontroller was programmed in the C language, while the graphical user interface (GUI) was developed in C#. The methodology of tests was based on international standards. The tests were carried out under controlled inlet pressure, at 150 kPa, and five to ten units were tested for each fitting model. The curves relating flow and minor losses were drawn based on minimum of 15 flow values, obtained under conditions of increase and decrease of flow rate in order to take into account possible effects of hysteresis related to the measurement system. In each flow rate, 30 points were collected resulting in a sample size of 900 points in each test. For each model of fitting evaluated, the following information was presented: curves of minor losses as a function of flow rate, minor loss coefficient (KL) and minor losses expressed as an equivalent length (Leq). The automated test bench enabled to carry out the experiments properly, being able to meet the requirements established by technical standards. The values of KL presented ranged from 2.70 to 24.08. Usually, that coefficient tended to become constant for Reynolds number higher than 10000. The sensitivity of the coefficient related to a ratio of the internal sections in the connections was also verified. The flow exponents presented values close to what is applied by the Darcy-Weisbach equation (m = 2).

An excised animal larynx model has been used in many studies to better understand the physiological and anatomical properties of the human larynx. One difference between an ex vivo model and an in vivo model is that ion loss occurs postmortem. To compensate for this in the excised model, researchers most commonly use a preservation method that includes completely submerging the specimen in isotonic saline (0.9% Na+Cl-) and then flash freezing it in liquid nitrogen. The flash freezing method allows researchers to maintain the integrity of the structures while also being able to gather specimens as they become available. Not enough research has been done to understand the effects of a preservation method on the outcomes of the study. Additionally, no common method has been established for preservation across studies to ensure that results are not being influenced by this variable. This prospective, mixed experimental design study includes three groups, a control group and two experimental groups. The control group consisted of 10 bench-mounted porcine larynges that were soaked in isotonic saline and flash frozen with liquid nitrogen. Prior to the experiment, the frozen larynges were thawed overnight before trials. The other two groups consisted of 10 bench-mounted porcine larynges each; these larynges were soaked in either isotonic saline or Ringer’s solution, a balanced fluid used in vivo to counteract dehydration. Larynges from these two groups were kept fresh and stored in a refrigerator overnight before trials. On the day of experimentation, each larynx was mounted on a bench top setup including three micropositioners to stabilize, adduct, and elongate the vocal folds. All the larynges were connected to a pseudolung via the trachea and humidified air was passed through to the vocal folds until phonation was achieved. Phonatory trials consisted of brief phonation followed by 5-minute desiccation intervals until phonation was no longer achieved. Phonation threshold flow (PTF), defined as the flow observed at the onset of phonation, was observed during each phonation trial; and flow values were compared within and between groups. Statistically significant differences were found between the Ringer’s group and the fresh saline group as well as between the Ringer’s group and the frozen saline group, indicating that PTF is influenced by the larynx preservation method.

Après le lancement du premier satellite artificiel en 1957, l'évolution de diverses technologies a favorisé la miniaturisation des satellites. En 1999, le développement des nano-satellites modulaires appelés CubeSats, qui ont la forme d'un cube d'un décimètre de côté et une masse de 1 kg à 10 kg, a été initié par un effort commun de l'Université polytechnique de Californie et de l'Université de Stanford. Depuis lors, grâce à l’utilisation de composants électroniques standards à faible coût, les CubeSats se sont largement répandus.Au cours des dernières années, le nombre de CubeSats lancés a régulièrement augmenté, mais moins de la moitié des missions ont atteint leurs objectifs. L'analyse des défaillances des CubeSats montre que la cause la plus évidente est le manque d’essais adéquats des composants du système ou du système au complet. Parmi les tâches particulièrement difficiles, on compte les essais « hardware-in-the-loop » (HIL) du système de contrôle d'attitude et d'orbite (SCAO) d’un CubeSat. Un système dédié à ces essais doit permettre des simulations fiables de l'environnement spatial et des mouvements réalistes des CubeSats. La façon la plus appropriée d’obtenir de telles conditions d’essai repose sur l’utilisation d’un coussin d'air. Toutefois, les mouvements du satellite sont alors contraints par les limites géométriques, qui sont inhérentes aux coussins d'air. De plus, après 15 années de développements de CubeSats, la liste des systèmes proposés pour tester leur SCAO reste très limitée.Aussi, cette thèse est consacrée à l’étude et à la conception d’un système robotique innovant pour des essais HIL du SCAO d’un CubeSat. La nouveauté principale du système d'essai proposé est l’usage de quatre coussins d'air au lieu d'un seul et l’emploi d’un robot manipulateur. Ce système doit permettre des mouvements non contraints du CubeSat. Outre la conception du système d'essai, cette thèse porte sur les questions liées: (i) à la détermination de l'orientation d’un CubeSat au moyen de mesures sans contact; (ii) au comportement de l’assemblage des coussins d'air; (iii) à l'équilibrage des masses du système.Afin de vérifier la faisabilité de la conception proposée, un prototype du système d'essai a été développé et testé. Plusieurs modifications destinées à en simplifier la structure et à réduire le temps de fabrication ont été effectuées. Un robot Adept Viper s650 est notamment utilisé à la place d'un mécanisme sphérique spécifiquement conçu. Une stratégie de commande est proposée dans le but d’assurer un mouvement adéquat du robot qui doit suivre les rotations du CubeSat. Finalement, les résultats obtenus sont présentés et une évaluation globale du système d'essai est discutée. / After the launch of the first artificial Earth satellite in 1957, the evolution of various technologies has fostered the miniaturization of satellites. In 1999, the development of standardized modular satellites with masses limited to a few kilograms, called CubeSats, was initiated by a joint effort of California Polytechnic State University and Stanford University. Since then, CubeSats became a widespread and significant trend, due to a number of available off-the-shelf low cost components.In last years, the number of launched CubeSats constantly grows, but less than half of all CubeSat missions achieved their goals (either partly or completely). The analysis of these failures shows that the most evident cause is a lack of proper component-level and system-level CubeSat testing. An especially challenging task is Hardware-In-the-Loop (HIL) tests of the Attitude Determination and Control System (ADCS). A system devoted to these tests shall offer reliable simulations of the space environment and allow realistic CubeSat motions. The most relevant approach to provide a satellite with such test conditions consists in using air bearing platforms. However, the possible satellite motions are strictly constrained because of geometrical limitations, which are inherent in the air bearing platforms. Despite 15 years of CubeSat history, the list of the air bearing platforms suitable for CubeSat ADCS test is very limited.This thesis is devoted to the design and development of an air bearing testbed for CubeSat ADCS HIL testing. The main novelty of the proposed testbed design consists in using four air bearings instead of one and in utilizing a robotic arm, which allows potentially unconstrained CubeSat motions. Besides the testbed design principle, this thesis deals with the related issues of the determination of the CubeSat orientation by means of contactless measurements, and of the behavior of the air bearings, as well as with the need of a mass balancing method.In order to verify the feasibility of the proposed design, a prototype of the testbed is developed and tested. Several modifications aimed at simplifying the structure and at shortening the fabrication timeline have been made. For this reason, the Adept Viper s650 robot is involved in place of a custom-designed 4DoF robotic arm. A control strategy is proposed in order to provide the robot with a proper motion to follow the CubeSat orientation. Finally, the obtained results are presented and the overall assessment of the proposed testbed is put into perspective.

Durante o processo de admissão do ar em motores de combustão interna, nota-se que sua aspiração não é ideal, ou seja, o volume do cilindro não é completamente ocupado, devido à variação de sua massa específica e perdas de carga ao longo do sistema de alimentação. Conseqüentemente, a eficiência volumétrica no cilindro atinge valores ínfimos de desempenho, o que afeta diretamente a potência do motor. O trabalho consiste em um estudo numérico e experimental do sistema de admissão de um motor de combustão interna. A solução numérica foi obtida por um código comercial que resolve as equações de transporte, baseada nos princípios de conservação de massa, quantidade de movimento e energia, pelo método de discretização de volumes finitos. Os resultados numéricos foram validados através dos resultados obtidos em uma bancada experimental, que possibilitou medidas de vazão mássica, pressão e temperatura do ar admitido. A bancada é formada por um motor de combustão interna acionado por um motor elétrico e o estudo foi realizado sem a presença de combustível e por conseqüência sem a ocorrência de combustão. Através da utilização do software, demonstrou-se que foi possível construir um coletor inédito que proporcionou ao motor estudado um aumento de eficiência volumétrica de 6% a 3.500 rpm. / During the process of intake air in the internal combustion engine it has been noted that air flow is not ideal, i.e., the cylinder volume is not completely occupied concerning the variation of specific mass and the charge loss along the feed system. Consequently, the volumetric efficiency in the cylinder reaches low values of performance, affecting the engine power. The aims of this work were a numerical and experimental study of the intake manifold in an internal combustion engine. The numerical solution is obtained through a commercial code which solves the transport equations, according to the continuity, momentum and energy principles by the method of finite volume discretization. Numerical data were validated by the experimental results set-up, enabling the mass flow, pressure and temperature measures of the intake air. The flow bench is composed by an internal combustion engine turned on by an electric engine. The study was developed without fuel and combustion. Regarding the software, it was possible to build an original intake manifold which provides to engine studied an increase in the volumetric efficiency of 6% at 3,500 rpm.

Abstract available in the Journal of Strength and Conditioning Research.