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Hälso- och sjukvårdspersonalen utsätts dagligen för risk att drabbas av stick- och skärskador. Det finns idag ett flertal lagar och riktlinjer som förordnar hur man som hälso- och sjukvårdspersonal skall arbeta för att undvika detta. Tidigare forskning visar dock att följsamheten till rutiner och riktlinjer kring patienter med blodsmitta är bristfällig. Syftet med studien var att i den vetenskapliga litteraturen identifiera faktorer som påverkar hälso- och sjukvårdspersonalens följsamhet till riktlinjer i vård av patienter med blodsmitta. Studien som genomförts är en littera-turstudie där tio artiklar granskats. Efter analys av artiklarna identifierades indivi-duella och organisatoriska faktorer som påverkade följsamheten. De organisato-riska faktorerna var bemanning, skyddsutrustning/säkerhetsklimat, arbetsledning och tidsaspekter. Faktorerna som var kopplade till individen var kunskap, erfaren-het och attityder. Avseende bemanningsfrågan visade flera studier ett samband mellan arbetsbelastning och ökad risk för stick- och skärskador. Följsamheten påverkades även av tillgången till skyddsutrustning. Ett flertal studier visade på att kunskapen hos hälso- och sjukvårdspersonalen varierade. Flertalet valde att inte använda skyddsutrustning när patienten inte hade en känd blodsmitta. / Health care workers are daily exposed to the risk of perforation, and injury. There are a number of laws and guidelines that order how health professionals should work to avoid this. However, we argue, that adherence to procedures and guide-lines on patients with blood infections are inadequate. The purpose of this study was to identify factors that influence health professional’s adherence to guidelines in the care of patients with blood contamination. The study conducted a literature review in which ten articles were reviewed. After analysis of the articles individ-ual and organizational factors affecting compliance were identified. The organiza-tional factors were manning, protective/safety climate, management and timing. The individual factors were related to knowledge, experience and attitudes. Re-garding the staffing issue, several studies proved a connection between workload and increased risk of perforation, and injury. Compliance was affected by the availability of protective equipment. Several studies showed that the skills of health workers varied. Most chose not to use protective equipment when the pa-tient had a not known blood infection.

The failure of oil well drillstrings due to torsional and longitudinal stresses caused by stick-slip phenomena during the drilling operation causes great expense to industry. Due to the complicated and harsh drilling environment, modelling of the drillstring becomes an essential requirement in studies. Currently, this is achieved by modelling the drillstring as a torsional lumped model (which ignores the length of the drillstring) for real-time measurement and control. In this thesis, a distributed-lumped model including the effects of drillstring length was developed to represent the drillstring, and was used to simulate stick-slip vibration. The model was developed with increasing levels of detail and the resultant models were validated against typical measured signals from the published literature. The stick-slip model describes the friction model that exists between the cutting tool and the rock. Based on theoretical analysis and mathematical formulation an efficient and adaptable model was created which was then used in the application of a method of species conserving genetic algorithm (SCGA) to optimise the drilling parameters. In conclusion, it was shown that the distributed-lumped model showed improved detail in predicting the transient response and demonstrated the importance of including the drillstring length. Predicting the response of different parameters along the drillstring is now possible and this showed the significant effect of modelling the drillcollar. The model was shown to better represent real system and was therefore far more suited to use with real time measurements. / Iraqi Government, Ministry of Higher Education and Scientific Research.

A qualitative analysis of a rotary traveling wave-type ultrasonic motor (USM) used to supply feedback forces in force-feel systems is carried out. Prior to simulation, the subsystems and contact mechanics needed to define the motor's equations of motion are discussed along with the pitfalls of modeling a USM. A mathematical model is assembled and simulated in MATLAB Simulink. Accompanying the dynamic model, a new reduced model is presented from which predictions of USM performance can be made without a complicated dynamic model. Outputs from the reduced model are compared with those of the dynamic model to show the differences in the transient solution, agreement in the steady state solution, and above all that it is an efficient tool for approximating a motor's steady state response as a function of varying the motor parameters. In addition, the reduced model provides the means of exploring the USMs response to additive loading, loads acting in the direction of motor motion, where only resistive loads, those opposite to the motor rotation, had been considered previously. Fundamental differences between force-feel systems comprising standard DC brushless motors as the feedback actuators and the proposed system using the USM are explained by referencing the USM contact mechanics. Outputs from USM model simulations are explored, and methods by which the motor can be implemented in the force-feel system are derived and proven through simulation. The results show that USMs, while capable of providing feedback forces in feel systems, are far from ideal for the task. The speed and position of the motor can be controlled through varying stator excitation parameters, but the transient motor output torque cannot; it is solely a function of the motor load, whether additive or resistive. / Master of Science

Pour fabriquer des produits de petites tailles, appelés micro-produits, l'utilisation de systèmes de production de dimensions habituelles conduit à des problèmes difficile à surmonter : coûts d'investissement et de fonctionnement des outils de production et problèmes techniques à cause des éffets d'echelle. Il en résulte une situation non concurrentielle même pour des systèmes automatisés.<br />La solution d'avenir consiste à disposer de systèmes de production dont les dimensions et les coûts sont en rapport avec les produits concernés : c'est le concept de micro-usine (microfactory).<br />L'objectif de cette thèse porte sur la conception et la commande d'une station de micromanipulation dédiée à une micro-usine. Afin d'assurer une flexibilité maximale à la micro-usine, nous proposons d'aborder la problématique de sa conception en développant à son maximum le concept de modularité. Il semble être une clé pour intégrer les spécificités d'un microsystème de production. Cette modularité doit se trouver au niveau de la commande, autant pour les tâches à réaliser que pour le pilotage de la station de micromanipulation.

O fenômeno de stick-slip, no processo de perfuração de poços de petróleo, é propiciado pela interação entre broca e formação rochosa e pode dar origem a grandes oscilações na velocidade angular podendo provocar danos irreparáveis ao processo. Neste trabalho, analisa-se o desempenho de leis de controle aplicadas à mesa rotativa (responsável por movimentar a coluna de perfuração), visando à redução de stick-slip e de oscilações da velocidade angular da broca. As leis de controle implementadas são do tipo PI (Proporcional-Integral), com parcelas de torque aplicado à mesa rotativa, proporcional e integral à velocidade da mesa, podendo ser com peso na broca constante ou variável. Para a coluna de perfuração, foi proposto um modelo em elementos finitos com função de forma linear. O torque na broca foi modelado segundo atrito de Coulomb pela forma não regularizada, curva esta ajustada pelos dados empíricos conforme propostas da literatura. Diversos critérios de desempenho foram analisados e foi observado que a minimização do desvio médio da velocidade angular em relação à referência propicia melhores condições de operação. Análises paramétricas dos ganhos de controle proporcional e integral foram realizadas, dando origem a curvas de nível para o desvio médio de velocidade angular na broca. A partir destas curvas, foram definidas regiões de estabilidade nas quais o desvio é aceitável. Estas regiões foram observadas serem maiores para menores pesos na broca e maiores velocidades angulares de referência e vice-versa. A adição do controle do peso na broca permitiu uma redução global dos níveis de desvio médio de velocidade angular, dando origem a um aumento das regiões de estabilidade do processo de perfuração. / The stick-slip phenomenon, in the process of drilling oil wells, due to the interaction between drill and rock formation can lead to large fluctuations in drill-bit angular velocity and, thus, cause irreparable damage to the process. In this work, the performance of control laws applied to the rotary table (responsible for moving the drill string) is analyzed, in order to reduce stick-slip and drill-bit angular velocity oscillations. The control laws implemented are based on a PI (Proportional-Integral) controller, for which the torque applied to the rotating table has components proportional and integral to table angular velocity with constant or variable WOB (Weight On Bit). For the drillstring, a finite element model with a linear interpolation was proposed. The torque on the drill-bit was modeled by a non-regularized Coulomb friction model, with parameters that were adjusted using empirical data proposed in literature. Several performance criteria were analyzed and it was observed that the minimization of the mean deviation of the drill-bit angular velocity relative to the target one would provide the best operating condition. Parametric analyses of proportional and integral control gains were performed, yielding level curves for the mean deviation of drill-bit angular velocity. From these curves, stability regions were defined in which the deviation is acceptable. These regions were observed to be wider for smaller values of WOB and higher values of target angular velocity and vice-versa. The inclusion of a controlled dynamic WOB reduced the levels of mean deviation of angular velocity, leading to improved stability regions for the drilling process.

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Die Kontaktverhältnisse zwischen Reifen und Fahrbahn bestimmen die maximal übertragbaren Beschleunigungs-, Brems- und Seitenkräfte des Fahrzeugs und sind daher für die Fahrsicherheit von großer Bedeutung. In dieser Arbeit wird ein Modell zur numerisch effizienten Simulation der hochfrequenten Dynamik einzelner Reifenprofilblöcke entwickelt. Der vorgestellte Modellansatz nutzt einerseits die Vorteile der Finite-Elemente-Methode, welche die Bauteilstruktur detailliert auflösen kann, bei der jedoch lange Rechenzeiten in Kauf genommen werden. Andererseits profitiert der vorgestellte Modellansatz von den Vorteilen stark vereinfachter Mehrkörpersysteme, welche die Berechnung der hochfrequenten Dynamik und akustischer Phänomene erlauben, jedoch strukturdynamische Effekte und das Kontaktverhalten in der Bodenaufstandsfläche des Reifens nur begrenzt abbilden können. Das hier vorgestellte Modell berücksichtigt in einem modularen Ansatz die Effekte der Strukturdynamik, der lokalen Reibwertcharakteristik, der nichtlinearen Wechselwirkungen durch den Kontakt mit der rauen Fahrbahnoberfläche und des lokalen Verschleißes. Die erforderlichen Modellparameter werden durch geeignete Experimente bestimmt. Ein Schwerpunkt der Arbeit liegt in der Untersuchung reibungsselbsterregter Profilblockschwingungen bei Variation der Modell- und Prozessparameter. Zur realistischen Betrachtung des Reifenprofilblockverhaltens erfolgt eine Erweiterung des Modells um eine Abrollkinematik, die tiefere Einblicke in die dynamischen Vorgänge in der Bodenaufstandsfläche des Reifens ermöglicht. Diese Simulationen lassen eine Zuordnung der aus der Literatur bekannten zeitlichen Abfolge von Einlaufphase, Haftphase, Gleitphase und Ausschnappphase zu. Es zeigen sich bei bestimmten Kombinationen aus Fahrzeuggeschwindigkeit und Schlupfwert ausgeprägte Stick-Slip-Schwingungen im akustisch relevanten Frequenzbereich. Das Modell erlaubt die Untersuchung des Einflusses der Profilblockgeometrie, der Materialparameter, der Fahrbahneigenschaften sowie der Betriebszustände auf den resultierenden Reibwert, auf das lokale Verschleißverhalten sowie auf das Auftreten hochfrequenter reibungsselbsterregter Schwingungen. Somit ermöglicht das Modell ein vertieftes Verständnis der Vorgänge im Reifen-Fahrbahn-Kontakt und der auftretenden Wechselwirkungen zwischen Struktur- und Kontaktmechanik. Es kann eine Basis für zukünftige Optimierungen des Profilblocks zur Verbesserung wesentlicher Reifeneigenschaften wie Kraftschlussverhalten, Verschleiß und Akustik bilden. / The contact conditions between tyre and road are responsible for the maximum acceleration, braking and side forces of a vehicle. Therefore, they have a large impact on the driving safety. Within this work a numerically efficient model for the simulation of the high-frequency dynamics of single tyre tread blocks is developed. The presented modelling approach benefits the advantage of the finite element method to resolve the component structure in detail. However, a long computation time is accepted for these finite element models. Moreover, the presented modelling approach makes use of the advantage of simplified multibody systems to calculate the high-frequency dynamics and acoustic phenomena. However, structural effects and the contact behaviour in the tyre contact patch can be covered only to a minor degree. The model treated here considers the effects of structural dynamics, the local friction characteristic, the non-linear interaction due to the contact with the rough road surface and local wear. The required model parameters are determined by appropriate experiments. One focus of this work is the investigation of self-excited tread block vibrations under variation of the model and process parameters. In order to realistically investigate the tread block behaviour the model is extended with regard to rolling kinematics which provides a deeper insight into the dynamic processes in the tyre contact patch. The corresponding simulations allow the allocation of the run-in phase, sticking phase, sliding phase and snap-out which is reported in the literature. For certain combinations of vehicle velocity and slip value pronounced stick-slip vibrations occur within the acoustically relevant frequency range. The model enables to study the influence of the tread block geometry, the material properties, the road surface characteristics and the operating conditions on the resulting tread block friction coefficient, local tread block wear and the occurrence of high-frequency self-excited vibrations. The simulation results provide a distinct understanding of the processes in the tyre/road contact and the interactions between structural mechanics and contact mechanics. They can be a basis for future tread block optimisations with respect to essential tyre properties such as traction, wear and acoustic phenomena.