The aim of this study is concentrated on the experimental investigation of wear resistance of rubber powder modified rubber blends. Styrene-Butadiene-Rubber (SBR) blends applied for conveying belt top covers have been modified by ground rubber (rubber powder) based on SBR. We theoretically described the rubber wear mechanism due to loading conditions occurring at conveyor belts in the field, to simulate wear behavior of top cover rubber materials. An own developed testing equipment based on gravimetric determination of mass loss of rubber test specimen was used investigating dynamic wear with respect to fracture properties of top cover materials. Furthermore we investigated fatigue crack growth (FCG) data over a broad range of tearing energy by Tear Analyzer to characterize crack propagation behavior of rubber powder modified rubber blends. Thus, we demonstrate the influence of rubber powder on resistance against occurrence of fracture as well as dynamic wear as a function of the rubber powder content in rubber blends applied for conveying belt top covers.

Der vorliegende Beitrag befasst sich mit dem Verhalten von Vibrationsförderern. Speziell für Förderer, welche nach dem Gleitprinzip arbeiten, werden Zusammenhänge zwischen der Antriebslage, dem Fördergut sowie der Ausrichtung des Förderorgans beschrieben. Durch Anwendung der vorgestellten Prinzipien wird eine Berechnungsmethode für die Fördergeschwindigkeit abgeleitet und anschließend mit Versuchswerten verglichen. / This paper deals with the behavior of vibrating conveyors. Especially for conveyors, using a sliding principle of movement, relations between the drive position, the conveyed goods and the orientation of the means of transport are described. By applying the principles presented, a method for calculating the conveying velocity is derived and compared with experimental values.

Ce manuscrit porte sur l’analyse, les méthodes de conception et la recherche de nouvelles structures de sources de courant, en se focalisant principalement sur les miroirs de courant, source la plus élémentaire. Le dépassement des limites actuelles pour l’optimisation du compromis vitesse-précision-consommation est l’objectif majeur des travaux présentés.La première partie est consacrée à l’étude de l’origine de ces limites et dresse l’état de l'art des structures de miroir de courant CMOS. Sont ensuite étudiées plus en détails, les possibilités offertes par les miroirs à entrée active. Une des premières contributions de nos travaux de recherche a été de proposer un formalisme dédié à l’étude et à l’implémentation de ce type de miroir, suivi de propositions d’amélioration à coût minimum de la topologie classique.Le développement d’une nouvelle approche de conception utilisant un principe de rétroaction non-linéaire en mode courant constitue la contribution majeure de cette thèse. La rétroaction est implémentée grâce à un convoyeur de courant de seconde génération dédié, très faible consommation et conçu pour avoir un comportement volontairement non-linéaire. Couplée avec des techniques classiques de régulation cascode pour une copie en courant de haute-précision, cette topologie constitue une source de courant élémentaire compétitive pour la réalisation de systèmes à haut niveau de performance.L'approche est mise en œuvre puis validée par la conception, en technologie CMOS 180nm, de deux circuits dédiés à la génération des courants dans les puces de stimulation neurale. L’ensemble des résultats obtenus dans ces dernières études démontre, qu’il est possible de dépasser les limites actuelles du compromis vitesse-précision-consommation, en se basant sur la stratégie de conception et les nouvelles topologies de miroirs à entrée active proposées. / The work presented in this manuscript involves analysis, design methods and search for improved structures of current sources, with main focus on the current mirrors, the most elementary current source. The main objective of our research was to outperform the present limitations in terms of speed, power and accuracy that exists in CMOS current mirror design.In the first part of the manuscript, we investigate on the origin of these limitations and present a literature review of popular and recent advanced current mirror structures. Then follow a deeper analysis of active-input current mirror capabilities. The first scientific contributions were, the development of analytical tools dedicated to the implementation of the standard active-input topology, supported by two solutions for dynamic range and stability improvements at minimal costs.The proposition of a novel design approach, relying on a power-efficient speed boosting technique based on current-mode non-linear control loops, constitutes the major contribution of the work presented in this manuscript. The feedback circuit is implemented using a custom low-power current conveyor (CCII), built to be intentionally non-linear. Coupled with classical regulated cascode structures required for high-precision current copy, this enhanced active-input current mirror topology forms a new competitive elementary current source to the design of high-performance systems.The approach is validated and illustrated with the realization of two circuits in 180 nm CMOS technology. Cores of the circuits are two examples of output stages dedicated to neural stimulation chips. Finally, Results of the last studies have demonstrated that, thanks to the design strategy and the new active-input current mirror topologies proposed, it is actually possible to outperform the present limit of the speed-power-accuracy trade-off.

Peruvian Airport Company (en adelante PAC) es la empresa a la cual se le ha adjudicado la concesión del mantenimiento, ampliación y administración del Aeropuerto Internacional Kuntur (en adelante AIK). De acuerdo con el contrato de concesión y el Plan de Desarrollo mínimo para la modernización de la infraestructura aeroportuaria, PAC está obligado a cumplir con hitos de inversión y mejoras obligatorias relacionadas con el incremento de las operaciones aeroportuarias. Para poder cumplir con ello, se busca que para el año 2022 el sistema actual incremente su capacidad de procesamiento de equipajes de 1,735 a 3,229 equipajes/hora en horario de máxima demanda. Mediante la implementación del programa “Mejoras en el sistema de transporte de equipajes” se busca ampliar y mejorar el sistema actual y evitar “cuellos de botella” y picos de demanda que podrían generar reclamos por parte de las aerolíneas y multas por incumplimiento de parte del organismo regulador (OSITRAN – MTC). Este programa está conformado por cuatro proyectos: Upgrade del sistema de máquinas de rayos X, Mejoras en el sistema de transferencia, Trabajos de Infraestructura y Ampliación e instalación de fajas transportadoras. El proyecto objeto de estudio del presente trabajo de investigación, es la Ampliación e instalación de fajas transportadoras en las zonas 01 a la 07 y deberá ser ejecutado en 453 días, desde el 06/02/2017 hasta el 31/10/2018. Se proyecta un valor actual neto de U$ 1,679,821 utilizando la tasa de retorno WACC de 9.26% y un presupuesto de $. 4,744,521. / Peruvian Airport Company (PAC) is the company that has been awarded the maintenance, expansion and administration of Kuntur International Airport (AIK). In accordance with the concession contract and the Minimum Development Plan for the modernization of airport infrastructure, PAC is obliged to comply with investment milestones and mandatory improvements related to the increase airport operations. In order to comply with this, the current system should process approximately 3,229 bags/hour during peak demand hours by 2022; however, it currently only processes 1,735 bags/hour. The implementation of the "Improvements in the baggage transport system" program seeks to expand and improve the current system and avoid "bottlenecks" and spikes in demand that could lead to airline claims and fines for non-compliance by the regulatory body (OSITRAN – MTC). This program involves four projects: Upgrade of the X-ray machine system, Improvements in the transfer system, Infrastructure Works and Expansion and installation of conveyor belts. The project under study covers only the supervision of the expansion and installation of conveyor belts in zones 01 to 07 and should be implemented in 453 days, from 06/02/2017 to 29/10/2018. A net present value of $1,679,821 is projected using WACC return rate 9.26% and a budgeted amount of $. 4,744,521. / Trabajo de investigación

Cette thèse porte sur la conception d'un circuit intégré CMOS pour l'électronique de lecture de capteurs bolométriques à base de semiconducteurs ou supraconducteurs haute-température. Dans ce manuscrit, une chaîne de traitement du signal est étudiée. Elle est composée d'un amplificateur différentiel à gain fixé pour des températures de 40 à 400K, ainsi que d'un filtre de fréquence passe-bas actif à haute dynamique. Une architecture optimale d'amplificateur est définie sans contre-réaction, permettant d'atteindre une large bande passante (17MHz pour un gain de 40dB), une consommation réduite (Iq = 2mA) et une haute impédance d'entrée. Afin de fixer le gain avec précision dans la structure CMOS, deux méthodes différentes sont présentées et vérifiées sur un circuit intégré. Par la suite, le comportement des filtres dans la bande d'atténuation est étudié afin d'augmenter la fréquence de coupure maximale. Deux structures avec une faible influence des éléments actifs « réels » sont conçues: le filtre Sallen-Key amélioré et la structure basée sur un convoyeur du courant CCII-. Enfin, nous présentons un CCII- intégré en CMOS ayant une très faible impédance de sortie.

This research investigates the problem of constrained sequencing of a set of jobs on a conveyor system with the objective of minimizing setup cost. A setup cost is associated with extra material, labor, or energy required due to the change of attributes in consecutive jobs at processing stations. A finite set of attributes is considered in this research. Sequencing is constrained by the availability of two elements ??orage buffers and conveyor junctions. The problem is motivated by the paint purge reduction problem at a major U.S. automotive manufacturer. First, a diverging junction with a sequence-independent setup cost and predefined attributes is modeled as an assignment problem and this model is extended by relaxing the initial assumptions in various ways. We also model the constrained sequencing problem with an off-line buffer and develop heuristics for efficiently getting a good quality solution by exploiting the special problem structure. Finally, we conduct sensitivity analysis using numerical experiments, explain the case study, and discuss the use of the simulation model as a supplementary tool for analyzing the constrained sequencing problem.

The design and operation of a high volume conveyor sortation system are important due to its high cost, large footprint and critical role in the system. In this thesis, we study the characteristics of the conveyor sortation system from performance evaluation and design perspectives employing continuous modeling approaches. We present two continuous conveyor models (Delay and Stock Model and Batch on Conveyor Model) with different representation accuracy in a unified mathematical framework. Based on the Batch on Conveyor Model, we develop a fast fluid simulation methodology. We address the feasibility of implementing fluid simulation from modeling capabilities, algorithm design and simulation performance in terms of accuracy and simulation time. From a design perspective, we focus on rates determination and accumulation design in the accumulation and merge subsystem. The optimization problem is to find a minimum cost design that satisfies some predefined performance requirements under stochastic conditions. We first transform this stochastic programming problem into a deterministic nonlinear programming problem through sample path based optimization method. A gradient based method is adopted to solve the deterministic problem. Since there is no closed form for performance metric even for a deterministic input stream, we adopt continuous modeling to develop deterministic performance evaluation models and conduct sensitivity analysis on these models. We explore the prospects of using the two continuous conveyor models we presented.

Le modèle de couche mince intégré sur l'épaisseur, Saint-Venant, utilisé classiquement pour simuler la propagation de laves torrentielles et coulées boueuses, repose sur plusieurs approximations concernant la forme des profils de vitesse en zones non-uniformes. Il est pourtant nécessaire d'utiliser ce type de modélisation, comme outil d'aide à la gestion des risques liés aux laves torrentielles. Nous proposons d'éprouver ses hypothèses, en observant une zone fortement non-uniforme, le front de coulées à surface libre et le champ de vitesse à l'intérieur de cette zone.En améliorant notre connaissance de l'évolution de la forme des profils de vitesse (de la dynamique interne) au front de coulées, nous cherchons à améliorer les modèles de couche mince. Cette thèse porte donc sur l'étude de la dynamique interne au front d'écoulements à surface libre de fluides newtoniens et viscoplastiques.Nous avons utilisé le dispositif du canal à fond mobile qui permet de générer des coulées stationnaires dans le référentiel de l'observateur au moyen d'un fond mobile remontant vers l'amont. Nous avons réalisé un travail technique sur ce canal et sur l'analyse des images pour pouvoir mesurer les champs de vitesse à haute résolution spatiale aux fronts de coulées à surface libre de fluides viscoplastiques. L'étude des fluides newtoniens a aussi été réalisée afin de valider les modèles et éprouver le dispositif expérimental.Nous avons comparé les résultats expérimentaux aux solutions théoriques de deux modèles de couche mince adaptés à la rhéologie de Herschel-Bulkley : le modèle classique de la lubrification, à la base du modèle de Saint-Venant et un modèle consistant à l'ordre 1 développé dans cette thèse. Le modèle consistant d'ordre 1 est la somme du modèle à l'ordre 0 (la lubrification) et de termes correctifs qui proviennent des contraintes normales et des termes d'inertie. Dans le cadre de notre configuration du fond mobile remontant vers l'amont, il est possible de déduire la forme du front en cherchant une solution de type onde progressive, sans passer par un modèle intégré dans l'épaisseur.Pour les fluides viscoplastiques, la structure classique du profil de vitesse, avec une zone cisaillée surmontée d'un plug non cisaillé est bien reconnaissable sur nos profils de vitesse en zone uniforme, et en zone faiblement variée. Mais à l'approche du front, cependant, la vitesse de surface augmente, les profils de vitesse expérimentaux deviennent cisaillés sur toute l'épaisseur, conduisant à la disparition du plug à proximité de la ligne de front.Le modèle de lubrification prédit l’existence d'un plug dans le front jusqu'à la ligne de contact, ce qui n'est pas observé expérimentalement. La vitesse de surface du modèle de lubrification augmente à l'approche du front, mais est largement sous-estimée par rapport à la vitesse de surface mesurée. Les vitesses de surface prédites par le modèle d'ordre 1 augmentent plus drastiquement au front, en meilleur accord avec les mesures que le modèle de lubrification. Pour certaines configurations expérimentales l'accord est même très bon. Remarquablement, le cisaillement des profils de vitesse à l'approche du front, observé expérimentalement, est aussi prédit par le modèle d'ordre 1.Les profils de vitesse présentent donc une évolution au front de coulées viscoplastiques en contradiction avec les hypothèses du modèle de Saint-Venant. Le modèle consistant d'ordre 1 permet d'améliorer les prédictions. Un modèle intégré dans l'épaisseur de type Saint-Venant basé sur les développements consistants d'ordre 1 est alors calculé, car il constitue l'étape nécessaire avant d'être intégré dans un outil de simulation opérationnel. / A depth-averaged model based on the thin-layer assumption, called Saint-Venant (Shallow-Water), is classically used to simulate the propagation and the spreading of debris and mud flows. It is based on several approximations concerning the shape of the velocity profile in non-uniform zones. We propose to test these hypotheses, examining a strongly non-uniform zone, the front of free-surface viscoplastic flows and the velocity field within this zone. By improving our knowledge about the internal dynamics in the front zone, we seek to improve the thin-layer models. This thesis therefore focuses on the study of the internal dynamics within the front of viscoplatic free-surface flows.We used the moving conveyor belt to generate stationary flows. We carried out a technical work on this set-up, and specific analysis of images obtained from the high-speed camera, in order to be able to measure velocity fields with a high resolution. The study of a Newtonian fluid was also carried out in order to validate the lubrication model and the experimental device.We compared experimental results to theoretical solutions of two thin-layer models taking into account the Herschel-Bulkley rheology: the classical model of lubrication, which is at the base of Saint-Venant model, and a consistent first-order model specifically developed in this thesis.The first-order model is equal to the zero-order model (lubrication), plus corrective terms derived from the normal stresses and inertia terms.In this study, for the purpose of comparison with our experimental results, we are interested in travelling-wave solutions. We are able to solve the shape of the front without using a depth-averaged model.Far from the front, experimental velocity profiles clearly display the characteristic 2-layer structure predicted by the lubrication solution, with constant values close to the free-surface (plug) and a sheared layer underneath. Closer to surge tip, the shape of experimental longitudinal velocity profilesthen begins to differ from the theoretical prediction. The 2-layer structure tends to disappear, and the profiles display shear across the whole depth ofthe flow. In this tip region, surface velocity also appears to increase faster than its theoretical counterpart. Surface velocity predicted by the first-order model increase more drastically in the tip region, in better agreement with the measurements than the lubrication model. The first-order model predicts a sheared velocity profile when approaching the front, as observed experimentally.The consistent first-order model then provides better predictions about internal dynamics than lubrication model. A depth-integrated model like Saint-Venant, based on consistent first-order developments is then calculated, as a first step before being integrated into an operational simulation tool.

The task performed in this assignment is to improve the reliability of Norden Machinery ABs product family. This is to be done by examining and replacing the belt used to stop the spreading of tubes from ingoing shipping crate to the infeed of the machine. The way that this was approached was by testing different candidates on a spectrum of their rigidity to find if a flexible or more rigid belt would perform better than the current context of the system. The testing was conducted for a period of 4 weeks and results were gathered by examining damages to the belts by the use of microscope. After the damage had been analyzed the conclusion was drawn that flexible alternatives seems to perform the task better than their rigid counterparts however more work is needed in the fields regarding the fastening and operation of the machine to use the best suited candidates derived from this test, the monolithic belt FMT-02TXCT-U1.

Made available in DSpace on 2016-06-02T19:53:33Z (GMT). No. of bitstreams: 1 SOUZA_Renato_2014.pdf: 1978160 bytes, checksum: c3d8365999634e1499ee6fe2898caa01 (MD5) Previous issue date: 2014-12-17 / Financiadora de Estudos e Projetos / This dissertation discusses the construction of the operational methods in the conveyor belt of sorting recyclable materials in a collectors' cooperative. Cooperatives represent not only a way out of the problems of management of municipal solid waste, but also a possibility of integration and income generation for people who are outside the formal work. Nevertheless, the search for income and better life clashes with precarious working conditions. In this context, the aim of this study is to understand how the cooperative regulate their activity against the difficulties in the conveyor belt of sorting recyclable materials. The applied methodology includes a case study outlined by the Activity Ergonomics. The results indicate both an intense physical and mental effort associated with the collection of recyclable materials. During the activity, the cooperative members face few situations which may affect the objectives and regulate their activity without risking their internal state. Collective joints emerge from the conveyor belt as a possibility of collective regulation of the difficulties arising from the instantaneous overlapping variations (volume, variety and condition of materials) and ascending and descending requirements. These results indicate that the collection of recyclable materials is only possible through the inventiveness of the cooperative members to use perceptual exploration and solve problems facing the pace of work. / Nesta dissertação se discute a construção dos modos operatórios na esteira de triagem de materiais recicláveis em uma cooperativa de catadores. As cooperativas representam não só uma saída para os problemas de gestão dos resíduos sólidos municipais, mas também uma possibilidade de integração e geração de renda para pessoas que estão à margem do trabalho formal. Apesar disso, a busca por renda e melhor condição de vida se choca nas precárias condições de trabalho. Nesse contexto, o objetivo deste estudo é compreender como os cooperados regulam sua atividade frente às dificuldades na esteira de triagem de materiais recicláveis. A metodologia aplicada conta com um estudo de caso delineado pela Ergonomia da Atividade. Os resultados indicam um intenso esforço físico e mental associado à triagem de materiais recicláveis. Durante a atividade os cooperados se deparam com poucas situações em que podem agir sobre os objetivos e regularem sua atividade sem colocar em risco seu estado interno. As articulações coletivas emergem da esteira como uma possibilidade de regulação coletiva das dificuldades advindas das sobreposições instantâneas das variabilidades (volume, variedade e estado dos materiais) e das prescrições ascendentes e descendentes. Esses resultados indicam que a triagem de materiais recicláveis só é possível graças à inventividade dos cooperados em utilizar a exploração perceptiva e resolver problemas frente ao ritmo de trabalho.