Dissertations / Theses: 'Operability'

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Filla, Reno. "Quantifying Operability of Working Machines." Doctoral thesis, Linköpings universitet, Fluida och mekatroniska system, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70394.

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In working machines the human operator is essential for the performance of the total system. Productivity and energy efficiency are both dependent not only on inherent machine properties and working place conditions, but also on how the operator manoeuvres the machine. In order to operate energy-efficient the operator has to experience the machine as harmonic. This is important to consider during the development of such working machines. It is necessary to quantify operability and to include this interaction between the human operator and the machine in both the later stages of a development project (where physical prototypes are evaluated by professional test operators) as well as in the earlier stages like concept design (where only virtual prototypes are available). The influence of the human operator is an aspect that is traditionally neglected in dynamic simulations conducted in concept design, because the modelling needs to be extended beyond the technical system. The research presented in this thesis shows two approaches to rule-based simulation models of a wheel loader operator. Both operator models interact with the machine model just as a human operator does with the actual machine. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. A “human element” can thus be introduced into dynamic simulations of working machines, providing more relevant answers with respect to operator-influenced complete-machine properties such as productivity and energy efficiency. While the influence of the human operator is traditionally ignored when evaluating machine properties in the early stages of the product development process, later stages are very reliant on professional test operators using physical prototypes. The presented research demonstrates how the traditional subjective evaluation of a machine’s operability can be complemented by a calculated measure for the operator’s control effort, derived from the recorded control commands of the machine operator. This control effort measure can also be calculated from the control commands of an operator model in a simulation, such as those presented in this thesis. It thus also allows for an assessment of operability already in the concept design phase. In addition, the results of a study of quantifying operator workload by means of measuring psycho-physiological data such as heart rate variability and respiration rate are presented as the first step towards realising workload-adaptive operator assistance functions. Once fully developed, the method itself can also be used as another complement to the traditional subjective evaluations of operability. This approach can then be applied not only in testing of physical prototypes, but also earlier in the product development process in studies on human-in-the-loop simulators. I arbetsmaskiner spelar föraren en avgörande roll för maskinens prestanda. Såväl produktivitet som energieffektivitet beror inte enbart av maskinens egenskaper och arbetsomgivningen, utan beror också av sättet på vilket föraren manövrerar maskinen. För att främja ett bränslesnålt körsätt ska maskinerna upplevas som harmoniska och det är viktigt att beakta detta vid utvecklingen. Det är nödvändigt att kvantifiera maskinharmonin och att ta hänsyn till interaktionen mellan föraren och maskinen i alla steg av ett utvecklingsprojekt. Detta gäller såväl sena faser, när fysiska prototyper redan har tagits fram och utvärderas av professionella provförare, såväl som tidiga faser som konceptutveckling, när endast virtuella prototyper finns tillgängliga. Förarens inflytande beaktas traditionellt inte i prestandasimuleringar i konceptfasen, eftersom detta innebär att mer än enbart det tekniska systemet måste modelleras. I den forskningen som presenteras här visas två olika regelbaserade modeller av hjullastarförare. Båda förarmodellerna använder maskinmodellen på samma sätt som en verklig förare använder en verklig maskin. Det visas att båda förarmodellerna kan anpassa sig till förändringar både i arbetsomgivningen och i maskinens egenskaper. I och med detta kan man utöka dynamiska simuleringar av arbetsmaskiner med ”ett mänskligt element”. Detta ger bättre resultat vad gäller produktivitet, energieffektivitet och liknande egenskaper som föraren påverkar i kompletta maskiner. Medan man i tidiga faser av produktutvecklingsprocessen traditionellt bortser från förarens inflytande, så är man i senare faser mycket beroende av att professionella provförare testar fysiska prototyper. Den här presenterade forskningen visar hur den traditionella subjektiva förarbedömningen av en maskins körbarhet kan kompletteras med ett mått på förarens ”spakarbete”, som beräknas utifrån en mätning på hur föraren använder sina kontroller för att styra maskinen. Detta mått på ”spakarbete” kan också beräknas utifrån de spaksignaler som genereras av förarmodellerna i en simulering. I och med detta kan en maskins körbarhet undersökas redan under konceptutvecklingen. I avhandlingen redovisas också resultaten från en studie som gjorts i syfte att kvantifiera förarens arbetsbelastning genom att mäta psykofysiologiska mått som variationer i hjärtfrekvens och andningsfrekvens. Studien är ett första steg mot att förverkliga en vision av stödfunktioner i arbetsmaskiner vilka anpassar sig efter förarens momentana arbetsbelastning. En sådan metod att mäta förarens arbetsbelastning kan också användas som ett komplement till den traditionella subjektiva förarbedömningen av en maskins körbarhet. Metoden kan inte bara användas vid provning av fysiska prototyper utan också tidigare i produktutvecklingsprocessen vid studier i avancerade körsimulatorer. IN ARBETSMASCHINEN spielt der Fahrer eine entscheidende Rolle für die Leistung des gesamten Systems. Produktivität und Energieeffizienz sind nicht nur abhängig von den Grundeigenschaften der Maschine und den Bedingungen am Einsatzort, sondern auch von der Art und Weise wie der Fahrer die Maschine manövreriert. Für eine kraftstoffsparende Fahrweise muss der Fahrer die Maschine als harmonisch erleben. Dies muss bei der Entwicklung beachtet werden. Das Erfassen der Fahrbarkeit und die Berücksichtigung des Zusammenspiels zwischen Fahrer und Maschine ist in allen Phasen der Entwicklung notwendig, sowohl in den späteren Phasen, wenn Prototypen von Erprobungsfahrern ausgewertet werden, als auch in den frühen Phasen wie dem Konzeptentwurf, wenn nur virtuelle Prototypen vorhanden sind. Der Fahrereinfluss wird traditionell in den dynamischen Simulationen während des Konzeptentwurfs vernachlässigt, denn er erfordert die Ausweitung der Modellierung über das technische System hinaus. In dieser Dissertation werden zwei Herangehensweisen zur Erstellung regelbasierter Modelle eines Radladerfahrers aufgezeigt. Beide Fahrermodelle interagieren mit dem Maschinenmodell gleich einem menschlichen Fahrer mit einer realen Maschine. Es wird gezeigt, dass beide Fahrermodelle in der Lage sind, sich auf Änderungen des Einsatzortes und der Maschineneigenschaften anzupassen. Somit kann „ein menschliches Element“ in die dynamische Simulation von Arbeitsmaschinen eingeführt werden, was zu qualitativ besseren Resultaten bezüglich Produktivität, Energieeffizienz und ähnlicher fahrerbeeinflusster Eigenschaften führt. Während man in den frühen Phasen der Produktentwicklung traditionell vom Fahrereinfluss absieht, ist man später sehr auf die Erprobung physischer Prototypmaschinen durch professionelle Testfahrer angewiesen. In dieser Dissertation wird aufgezeigt, wie die traditionell subjektive Bewertung der Fahrbarkeit einer Maschine mit einem Maß der „Steuerungsarbeit“ komplettiert werden kann, berechnet aus der gemessenen Betätigung der dem Fahrer zur Verfügung stehenden Bedienelemente. Dieses Maß der „Steuerungsarbeit“ kann auch aus den Signalen der von uns vorgestellten Fahrermodelle in einer Simulation berechnet werden. Damit kann man die Fahrbarkeit bereits in der Konzeptentwicklung abschätzen. Weiterhin werden die Resultate einer Studie zur Quantifizierung der Fahrerbelastung mithilfe psychophysiologischer Daten wie Veränderungen der Herzfrequenz und Atmungsfrequenz vorgestellt. Diese Studie ist ein erster Schritt zur Entwicklung eines Assistenzsystemes, dass sich an die aktuelle Fahrerbelastung anpasst. Eine solche Messmethode der Fahrerbelastung kan auch zusätzlich zur traditionellen subjektiven Fahrbarkeitseinschätzung angewendet werden – nicht nur bei der Erprobung physischer Prototpyen, sondern auch schon frühzeitig bei Studien auf Fahrsimulatoren.

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Munro, Stuart. "Scramjet Intakes: Designing for Performance and Operability." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491519.

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The classical approach to scramjet intake design, analysis, experimental testing, and performance assessment treats the intake as separate from the rest of the vehicle. This thesis argues that a more integrated approach is necessary. The design space of Mach 7 two-dimensional, axi-symmetric spike and Busemann-type intakes with focused forebody waves and throats expanded to the Kantrowitz limit is parameterised geometrically and stream thrust average performance parameters calculated across the range of possible intake designs. An engine cycle is applied to arbitrate between conflicting capability and efficiency design points. The two-dimensional analysis is extended to include angle of attack, off-design Mach number and defocused conditions. Intakes with sharp leading edges and moderate turning angles are found to perform optimally, and the relatively large combustor hydraulic diameter and higher capability of inward turning designs are found to improve engine performance significantly. An upper bound is established for the performance of stream-traced Busemann intakes and it is shown how the performance of truncated Busemann derivatives may be improved by extending the leading edge at constant angle. The thesis also describes complementary experiments investigating intake operability carried out in the University of Oxford's gun tunnel. This facility was converted to operate as a Ludwieg tube with Light piston Isentropic Compression Heating (LICH) to improve flow steadiness when matching Reynolds numbers and temperature ratios to 2:5 scale Mach 7, 30 km altitude flight. Tunnel stagnation temperatures are measured and correlations to the fill pressures and stagnation pressure history are determined. The design and build of a two-dimensional wedge intake with isolator to determine intake starting limits by varying cowl position and shoulder angle is described. The isolator is shown to degrade starting characteristics by increasing the likelihood of internal choking. The implementation of a self-starting test, employing gas injection via fast acting valves, is implemented to demonstrate the self-starting characteristics of an axi-symmetric spike intake with internal contraction exceeding the Kantrowitz limit. Fuel injection and combustor back pressure are also simulated at angle of attack. Boundary layer trips are shown to significantly improve the operability of both models tested.

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Davies, Matthew Lloyd. "Exploiting nonlinear kinetics to enhance process operability." Thesis, University of Leeds, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270897.

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BECERRA, MELISA YVONE ZAMBRANO. "OPERABILITY LIMITS OF THE CURTAIN COATING PROCESS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=15502@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO O revestimento por cortina é um dos processos preferidos para revestir o substrato de varias camadas de líquido à altas velocidades. Este tipo de processo pertence a classe de método de revestimento de vazão pre-fixada. O processo consiste num líquido de revestimento caindo livremente de uma altura considerável sob ação da gravidade sobre o substrato em movimento a ser revestido. Existem várias aplicações industriais deste processo, como filmes óticos, fitas adesivas e magnéticas, papéis especiais entre muitos outros. As mais importantes vantagens são revestimento à altas velocidades, adaptação a uma grande variedade de líquidos e flexibilidade na aplicação de finas camadas de líquidos em superfícies irregulares. Os limites operacionais do processo são determinados por diferentes instabilidades no escoamento perto da zona de encontro entre o líquido e o substrato como entrada de ar, formação de calcanhar e a cortina sendo puxada pelo substrato, e pela quebra da cortina de líquido. O objetivo principal deste trabalho é analisar teórico e experimentalmente esses limites operacionais, focando nos efeitos dos parâmetros operacionais, aditivos no líquido de revestimento no escoamento que ocorre na zona de encontro entre o líquido e o substrato, e na quebra da cortina. Para descrever o escoamento bidimensional que ocorre no processo de revestimento por cortina, na simulação numérica, foram utilizadas as equações de conservação de massa e de conservação de quantidade de movimento. O sistema de equações diferenciais foi resolvido utilizando o método de Galerkin e o sistema não linear foi resolvido com o método de Newton. Resultados teóricos, na zona de encontro entre líquido e o substrato, mostram a configuração do escoamento para líquidos Newtonianos, incluindo a formação de calcanhar e a cortina puxada pelo substrato como uma função da velocidade do substrato, da altura da cortina e da vazão. Estes resultados foram comparados com os resultados da visualização experimental encontrando assim a janela de operação do processo em função dos parâmetros operacionais. Na zona do escoamento da cortina, a condição crítica na qual cortina de líquido quebra foi determinada como uma função das propriedades reologicas dos líquidos de revestimento. Os resultados mostram que as propriedades viscoelásticas influenciam no balanço de forças no escoamento da cortina. Líquidos com alta viscosidade extensional podem reduzir notavelmente a vazão mínima necessária para formar e manter cortinas estáveis. Curtain coating is one the preferred methods for precision multi-layer coatings at high speeds. Curtain coating belongs to the class of premetered coating methods. Liquid falls as a sheet, or curtain, freely over a considerable height and under the action of gravity before it impinges onto the substrate being coated. Edge guide are needed to maintain at specific width of the falling curtain. Precision curtain coating was originally developed for multi-layer photographic film but its use has expanded to many different applications such as optical films and specialty papers. Some advantages of this process include very high coating speeds, adaptability to a wide range of liquids and flexibility to apply thin liquid layer to irregular surfaces. The operability limits of the process are set by different flow instabilities in the coating bead, such as air entrainment, low speed heels and curtain pulling, and by curtain breakup. The goal of this research is to analyze these operability limits by theory and experiments. The focus is to determine the effect of operating parameters; edge guides design and polymer additives on the coating solution on the bead configuration and liquid curtain breakup. The conservation mass and momentum equations with the boundary conditions were used to describe the flow. The equations were solved all together by Galerkin’s method with finite element basis functions and non-linear system solved by Newton’s method. Theoretical results show the bead configuration, including heel formation and curtain pulling as a function of web speed, curtain height and flow rate. Theoretical predictions will also be extended to include viscoelastic behavior of the coating liquid. This results was compared with experimental results to obtain the coating windows for fixed parameters. The visualization results show the critical condition at which a viscoelastic liquid curtain breaks was determined as a function of the rheological properties of the coating liquid. The results show that the viscoelastic properties can affect the force balance in the curtain flow. High extensional viscosity liquids can drastically reduce the minimal flow rate to create more stable curtains.

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Hattingh, Caleb. "On the operability of heat exchanger networks." Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/5320.

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Bibliography: leaves 127-132. The dynamic operability of processes refers to the degree to which plants may be satisfactorily controlled. This report presents a study of the operability of heat exchanger networks (HENs).The integration of heat exchange systems such as HENs typically results in significant steady-state cost savings which is the motivation for their implementation. However, such integration may lead to problems in the dynamic operation of the system if the operability of HENs is not considered. Operability analysis techniques are presented that provide a quantitative measure of the operability of HENs that is related to the minimum integral setpoint error of a closed-loop HEN under a step disturbance. The different operability analysis techniques are specified by ,u sing different controller types which are optimally tuned in an optimization framework. The different controllers include PI (proportionalintegral) control, MPC (model predictive control), optimal linear control (via Qparametrization) and an optimal open-loop control strategy that represents the best possible closed-loop performance.

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Seaman, David Richard. "Operability analysis of an industrial communication circuit." Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/5405.

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Ramadaan, Safa Y. "Reliability analysis for hazard and operability studies." Thesis, Aston University, 1987. http://publications.aston.ac.uk/10215/.

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Fault tree analysis is used as a tool within hazard and operability (Hazop) studies. The present study proposes a new methodology for obtaining the exact TOP event probability of coherent fault trees. The technique uses a top-down approach similar to that of FATRAM. This new Fault Tree Disjoint Reduction Algorithm resolves all the intermediate events in the tree except OR gates with basic event inputs so that a near minimal cut sets expression is obtained. Then Bennetts' disjoint technique is applied and remaining OR gates are resolved. The technique has been found to be appropriate as an alternative to Monte Carlo simulation methods when rare events are countered and exact results are needed. The algorithm has been developed in FORTRAN 77 on the Perq workstation as an addition to the Aston Hazop package. The Perq graphical environment enabled a friendly user interface to be created. The total package takes as its input cause and symptom equations using Lihou's form of coding and produces both drawings of fault trees and the Boolean sum of products expression into which reliability data can be substituted directly.

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Rashid, Muhammad. "Stability and dynamic operability analysis of chemical processes." Title page, table of contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09ENS/09ensr224.pdf.

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Yee, Kevin Wing Kan Chemical Sciences &amp Engineering Faculty of Engineering UNSW. "Operability analysis of a multiple-stage membrane process." Publisher:University of New South Wales. Chemical Sciences & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41287.

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Membrane processes have found increasing industrial applications worldwide. For membrane processes to deliver their desired performances and mitigate the effect of disturbances, automatic controllers must be installed. Before the installation of controllers, operability analysis is a crucial step to evaluate how well the processes can be controlled, and to determine how process design can be improved for better control. However, existing applications of operability analysis in membrane processes are limited. This thesis extends the application of operability analysis to a multiple-stage membrane process, exemplified by a detailed case study of a 12-stage industrial whey ultrafiltration (UF) process. Process dynamic models are determined to describe the transient behaviour of process performance caused by disturbances and long-term fouling. Steady-state nonlinear operability analysis is conducted to identify inherent limitations of the process. Using the process dynamic models, dynamic operability analysis is performed to determine the effects of dynamic behaviour on process and controller design. Steady-state operability analysis shows that the whey UF process is not able to mitigate the effects of high concentrations of true protein in the fresh whey feed. The ability of the process to mitigate the effects of disturbances is also adversely affected by long-term membrane fouling. Mid-run washing is therefore necessary to restore control performance after long periods of operation. Besides demonstrating the adverse effects of long-term membrane fouling on operability, dynamic operability analysis identifies the manipulated variables that can deliver the best control performance. It also indicates that control performance can be improved by installing equipment (e.g. buffer tanks) upstream of the process. Dynamic operability analysis shows that recycling of the retentate stream has a profound effect on the plant-wide dynamics and reduces significantly the achievable speed of process response under automatic control. However, retentate recycling is essential during operation to minimize membrane fouling. Although reducing the number of stages in the whey UF process can improve the achievable speed of process response under automatic control, process performance will fluctuate significantly from its desired level. A trade-off therefore exists between process performance and control performance that should be addressed during process and controller design.

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Mehdi, Ahad. "Effect of swirl distortion on gas turbine operability." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/12129.

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The aerodynamic integration of an aero-engine intake system with the airframe can pose some notable challenges. This is particularly so for many military air- craft and is likely to become a more pressing issue for both new military systems with highly embedded engines as well as for novel civil aircraft configurations. During the late 1960s with the advent of turbo-fan engines, industry became in- creasingly aware of issues which arise due to inlet total pressure distortion. Since then, inlet-engine compatibility assessments have become a key aspect of any new development. In addition to total temperature and total pressure distortions, flow angularity and the associated swirl distortion are also known to be of notable con- cern. The importance of developing a rigorous methodology to understand the effects of swirl distortion on turbo-machinery has also become one of the major concerns of current design programmes. The goal of this doctoral research was to further the current knowledge on swirl distortion, and its adverse effects on engine performance, focusing on the turbo-machinery components (i.e. fans or compressors). This was achieved by looking into appropriate swirl flow descriptors and by correlating them against the compressor performance parameters (e.g loss in stability pressure ratios). To that end, a number of high-fidelity three-dimensional Computational Fluid Dynamics (CFD) models have been developed using two sets of transonic rotors (i.e. NASA Rotor 67 and 37), and a stator (NASA Stator 67B). For the numerical purpose, a boundary condition methodology for the definition of swirl distortion patterns at the inlet has been developed. Various swirl distortion numerical parametric studies have been performed using the modelled rotor configurations. Two types of swirl distortion pattern were investigated in the research, i.e. the pure bulk swirl and the tightly-wound vortex. Numerical simulations suggested that the vortex core location, polarity, size and strength greatly affect the compressor performance. The bulk swirl simula- tions also showed the dependency on swirl strength and polarity. This empha- sized the importance of quantifying these swirl components in the flow distortion descriptors. For this, a methodology have been developed for the inlet-engine compatibility assessment using different types of flow descriptors. A number of correlations have been proposed for the two types of swirl distortion investigated in the study.

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Herbert, Jasmine. "Operability and performance analysis of various control valves." Thesis, Herbert, Jasmine (2015) Operability and performance analysis of various control valves. Other thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/28659/.

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In 2015 an assortment of control valves were implemented in the Murdoch University Instrumentation and Control Laboratory and in the Pilot Plant. This project is a result of this proposed implementation and is important to gain a proper understanding of the valves’ usage; behaviour; and to confirm the new valves are an improvement on any valves they may be replacing. This project aimed to compare and analyse the operability and performance of the Baumann 24000S with Fisher 3660 Positioner and the existing Badger Meter Research Control Valves within the Instrumentation and Control Laboratory. The operability and performance was analysed by investigating the valves’ usage; functionality; hysteresis; valve type and sizing; dead band; and dead time. The first test checked if one valve opening resulted in two flow rates for different directions of the stem movement (otherwise known as hysteresis). Eliminating hysteresis is important as it signifies that the valve is less susceptible to variations caused by friction and other forces, resulting in a single flow rate for each valve opening. The valve type, sizing and usage was analysed with the flow coefficient and characteristic curves. The flow coefficient indicates a valve’s maximum flow capacity, whereas the characteristic curve shows the flow behaviour with change in valve opening; this should be as linear as possible. The type and size of a valve is important in order to optimise a process. A valve that is too small will not allow sufficient fluid to pass; whereas a valve that is too big will cause most of the process gain to come from the valve and not the controller [1]. Dead band is the range the valve opening can change in both directions without change in the flow being observed; this is a result of backlash and friction. The smaller the dead band the better the valve’s ability is to respond to minor changes. Dead time allows the evaluation of the valve’s response time, in order to compare the speed of the valves. In comparing the Research Valve results to the Baumann 24000S results, the Baumann 24000S had no visible hysteresis; it had the strongest linear relationship; it had a small dead band of 0.5% and a quicker dead time. Based on these findings it is determined that the Baumann 24000S surpasses the performance of the Research Valve; therefore it is advised that the Baumann 24000S with Fisher 3660 positioner is a suitable replacement for the Badger Meter Research Valve.

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Abd, Halim Muhammad Fuad. "Operability and performance analysis of various control valves." Thesis, Abd Halim, Muhammad Fuad (2016) Operability and performance analysis of various control valves. Honours thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/30797/.

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A control valve is a force worked gadget which alters the liquid stream rate in a procedure control framework. It comprises of a valve associated with an actuator component that is equipped for changing the position of a stream controlling component in the valve because of a sign from the controlling framework. This thesis is about operability and performance analysis of various control valves in Murdoch University. The hardware test and the behaviour test have been done throughout the project. The results are provided through the report exclusively.

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Stevens, Andrew Patrick. "Naval Ship Preliminary Arrangements for Operability and Reduced Vulnerability." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/82975.

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This thesis presents a process and tool that generates representative preliminary ship models and arrangements for use in vulnerability analysis in the Concept and Requirements Exploration (CandRE) process used at Virginia Tech. CandRE uses a Multi-Objective Genetic Optimization (MOGO) to explore the design space for non-dominated ship design solutions based on design effectiveness, risk, and cost. Vulnerability is assessed as part of the CandRE using a Preliminary Arrangements and Vulnerability (PAandV) model. Representative ship arrangements for specified combinations of ship system options are created based on operability needs, ship mission needs, and improved vulnerability. These are then analyzed for vulnerability and are used to calculate a representative Overall Measure of Vulnerability (OMOV) which is used to calculate the Overall Measure of Effectiveness (OMOE) in the MOGO. Master of Science

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Calandranis, John Christos. "Operability studies in heat exchanger networks : analysis, control and synthesis." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14393.

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Bahri, Parisa A. "A new integrated approach for operability analysis of chemical plants." Connect to full text, 1995. http://hdl.handle.net/2123/4015.

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Thesis (Ph. D.)--University of Sydney, 1996. Title from title screen (viewed on February 3, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Chemical Engineering. Degree awarded 1996, thesis submitted 1995. Includes bibliographical references. Also issued in print.

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Padley, Mark Andrew. "Incorporating operability measures into the process synthesis stage of design." Phd thesis, Department of Chemical Engineering, 1991. http://hdl.handle.net/2123/5996.

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Maneschijn, Anton. "A framework and criteria for the operability of unmanned aircraft systems." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5153.

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Thesis (PhD (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. Dissertation presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering at Stellenbosch University. ENGLISH ABSTRACT: Airworthiness certification of unmanned aircraft systems (UAS) is normally considered to be a regulatory function. In the absence of comprehensive UAS airworthiness regulations, the development of new and unique UAS, and their introduction into non-segregated airspace, remain major challenges for the UAS industry and regulators. Thus, in response, the objective of this research was to establish a framework and guidelines, within the scope of the typical regulatory regime, that can be used by the UAS engineering domain to ensure the safe and reliable functioning of a UAS, whether regulated or not. UAS airworthiness is currently mainly based on manned aircraft regulations, and the focus is on the unmanned aircraft and the 'airworthiness' of the remote control station. The typical UAS as a system, however, consists of more than just these elements and a broader approach to the 'airworthiness' of a UAS is required. This study investigated and introduces the concept of UAS operability, where the term 'operability' addresses the safe and reliable functioning of the UAS as a system, the airworthiness of its airborne sub-systems, and the safe and reliable functioning of its non-airborne subsystems and functional payloads. To ensure that the results of this study are aligned with typical aviation regulatory systems, a regulatory basis was defined within which UAS operability guidelines could be developed. Based on the operability concept, and in the scope of the regulatory basis, a UAS operability framework was developed for the UAS engineering domain. This framework is an index and reference source from which appropriate operability elements can be selected for a particular UAS. The scope of the framework is generic, rather than UAS-type or -class specific, and includes operability elements for the UAS as a system, for its airborne and non-airborne sub-systems, and for its payloads. The framework was validated by developing lower hierarchical levels for the framework and by populating each operability element of the framework with appropriate engineering guidance criteria. The guidance criteria were derived and/or developed from industry 'best practices' found in the literature, or were newly developed where no existing practices were found. The significance of this study is found in its establishing of a generic UAS operability framework that not only focuses on the airworthiness of the unmanned aircraft, but addresses the operability of the UAS as a system, as well as the operability of its airborne sub-systems, its non-airborne sub-systems and its payloads. In practice, the UAS operability framework can be used in the UAS engineering domain as an index and reference source to select relevant operability elements for a particular UAS. The guidance criteria for the selected elements can subsequently be used to develop the appropriate processes, procedures, requirements and specifications to achieve initial operability of the UAS, and to maintain its continued operability. Although the objective of the research was achieved, the UAS operability framework must still be applied and tested in real-life UAS projects and, where necessary, revised to eliminate shortcomings and to provide for new and novel developments in UAS engineering technologies. AFRIKAANSE OPSOMMING: Die lugwaardigheidsertifisering van onbemande vliegtuigstelsels (OVS) word normaalweg beskou as 'n reguleringsfunksie. In die afwesigheid van omvattende OVS lugwaardigheidsregulasies bly die ontwikkeling van nuwe en unieke OVS, en die inbedryfstelling daarvan in onafgesonderde lugruim, besonderse uitdagings vir beide die OVS nywerheid en reguleerders. Die doelwit van hierdie navorsing was dus om riglyne binne die bestek van die tipiese reguleringsregime te vestig wat deur die OVS ingenieursdomein benut kan word om die veilige en betroubare funksionering van 'n OVS te verseker, of dit gereguleer word aldan nie. OVS lugwaardigheid word tans hoofsaaklik gebaseer op lugwaardigheidsvereistes vir bemande vliegtuie. Die fokus is dan ook meerendeels op die onbemande vliegtuig en die 'lugwaardigheid' van die afstandbeheerstasie. Die tipiese OVS bestaan egter uit meer sub-stelsels en 'n weier beskouing van die 'lugwaardigheid' van 'n OVS is nodig. Die konsep van OVS bedryfbaarheid is in hierdie studie ondersoek en voorgestel. 'Bedryfbaarheid' beteken in hierdie konteks die veilige en betroubare funksionering van die OVS as 'n stelsel, die lugwaardigheid van die lug sub-stelsels, die veilige en betroubare funksionering van die nie-lug sub-stelsels, asook die veilige en betroubare funksionering van funksionele loonvragte. Om te verseker dat die resultate van hierdie studie versoenbaar is met tipiese lugvaart reguleringstelsels, is 'n reguleringsbasis omskryf vir die ontwikkeling van OVS bedryfbaarheidsriglyne. Gebaseer op die bedryfbaarheidskonsep, en binne die riglyne van die reguleringsbasis, is 'n OVS bedryfbaarheidsraamwerk ontwikkel vir die OVS ingenieursdomein. Die raamwerk is 'n indeks en verwysingsbron waaruit gepaste bedryfbaarheids-elemente gekies kan word vir 'n bepaalde OVS. Die bestek van die raamwerk is generies en nie beperk tot spesifieke OVS tipes of klasse nie. Die raamwerk sluit bedryfbaarheidselemente in vir die OVS as stelsel, asook vir die lug en nie-lug sub-stelsels van die OVS, en vir die loonvragte van die OVS. Die raamwerk se geldigheid was bevestig deur die struktuur van die raamwerk tot laer vlakke uit te brei en gepaste ingenieursriglyne vir elke bedryfbaarheids-element in die raamwerk te ontwikkel. Die riglyne was gebaseer op 'beste praktyke' soos beskryf in die literatuur, of was van nuuts af ontwikkel waar geen bestaande praktyke gevind kon word nie. Die bydrae van hierdie studie is gesetel in die vestiging van 'n generiese OVS bedryfbaarheidsraamwerk wat nie net gemik is op die lugwaardigheid van die onbemande vliegtuig nie, maar wat die bedryfbaarheid in geheel van die OVS as stelsel aanspreek, asook die bedryfbaarheid van die OVS se lug sub-stelsels, nie-lug sub-stelsels en loonvragte. In die praktyk kan die raamwerk in die OVS ingenieursdomein gebruik word om gepaste bedryfbaarheids-elemente vir 'n OVS te kies. Daarna kan die bedryfbaarheidsriglyne gebruik word om gepaste prosesse, prosedures, vereistes en spesifikasies te ontwikkel om die OVS se aanvanklike en voortgesette bedryfbaarheid te bewerkstellig. Alhoewel die doelwit vir die navorsing bereik is, moet die OVS bedryfbaarheidsraamwerk nog op werklike OVS projekte getoets word. Waar nodig, moet die raamwerk dan hersien word om tekortkominge, asook nuwe en unieke ontwikkelinge in OVS ingenieurstegnologie, aan te spreek.

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Jefferson, Matthew. "A modular method for hazard and operability studies of process plant." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/7456.

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The identification of hazards in chemical plants has become increasingly important. Not only have chemical plants become larger and more complex, but some countries now have regulations requiring that some form of formal hazard identification be carried out. With the increased speed of many other parts of the design process, hazard identification is becoming the log-jam in attempts to speed up the design of new plants still further. One of the most popular techniques for hazard identification is a hazard and operability study (HAZOP), in which a group of people attempt to identify creatively the possible hazards by applying a methodical process whereby the effect of deviations to every process variable is considered in every part of the plant. The aim of this thesis is to explore methods of improving hazard identification through the development of the HAZOP technique. This thesis examines possible improvements that can be made through a better understanding of activities and how they are carried out in HAZOP, discusses the possibilities of automated hazard identification based on HAZOP, and in particular presents a novel, modular HAZOP methodology. Modular HAZOP is based around identifying the modules that make up a chemical plant and then using previously generated HAZOP results associated with each of the modules. The hazards associated with these modules will therefore be known and rules are required to deal with the interconnections between modules. Application of these rules determines any additional hazards that might arise from the interconnection of modules. A number of important principles have been identified including, the level of decomposition required, the use of interchangeable sub-modules within modules, the fact that the majority of cause-consequence scenarios exist in adjacent modules, and the categorisation of locally and remotely propagated effects. These provide for a procedure which is adaptable to different plant configurations, but can also be quickly and easily applied. The latter principles enable the simpler fault paths, which make up most of the cause-consequence scenarios, to be identified quickly, leaving a much reduced number of fault paths which require a more thorough analysis.

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Tesanovic, Manuela, and Summia Al-mufti. "Mobile application design for contextual usability and operability in underground mines." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-168375.

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The aim of the thesis was to develop a usable mobile application prototype to be used in the underground mining environment. In order to fulfill the aim, the research question How can a mobile application be designed for usability with focus on operability for an underground mine? was researched, analysed and answered. The main methods for driving the design process were ISO 9241-210, Human-centred design for interactive systems, requirement engineering and conceptual design. The results of the thesis were based on qualitative data, collected from semi-structured interviews from five respondents. These respondents had a background as a operator in underground mines in different countries. The qualitative data was analysed and interpreted into functional and non-functional user requirements. The user requirements in parallel with design principles were used to produce a final concept that would be transformed from a low fidelity into a high fidelity prototype. The high fidelity prototype was developed using Android Studio, Java and later tested and evaluated using SUS questionnaire and usability heuristics to rate the overall usability of the application . The answer to the research question lied in the methodology used in this thesis. This was achieved by involving the stakeholders, people affected by the future design in the entire process, with different methodology during the different phases of the design process.

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Ross, Roderick. "Dynamic operability assessment : a mathematical programming approach based on Q-parametrization." Doctoral thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/19814.

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Bibliography: pages 197-208. The ability of a process plant to guarantee high product quality, in terms of low variability, is emerging as a defining feature when distinguishing between alternative suppliers. The extent to which this can be achieved is termed a plant's dynamic operability and is a function of both the plant design and the control system design. In the limit, however, the closedloop performance is determined by the properties inherent in the plant. This realization of the interrelationship between a plant design and its achievable closed-loop performance has motivated research toward systematic techniques for screening inherently inferior designs. Pioneering research in the early 1980's identified right-half-plane transmission zeros, time delays, input constraints and model uncertainty as factors that limit the achievable closedloop performance of a process. Quantifying the performance-limiting effect of combinations of these factors has proven to be a challenging problem, as reflected in the literature. It is the aim of this thesis to develop a systematic procedure for dynamic operability assessment in the presence of combinations of performance-limiting factors. The approach adopted in this thesis is based on the Q-parametrization of stabilizing linear feedback controllers and involves posing dynamic operability assessment as a mathematical programming problet? In the proposed formulation, a convex objective function, reflecting a measure of closed-loop performance, is optimized over all stable Q, subject. to a set of constraints on the closed-loop behavior, which for many specifications of interest is convex. A discrete-time formulation is chosen so as to allow for the convenient hand.ling of time delays and time-domain constraints. An important feature of the approach is that, due to the convexity, global optimality is guaranteed. Furthermore, the fact that Q parametrizes all stabilizing linear feedback controllers implies that the performance at the optimum represents the best possible performance for any such controller. The results are thus not biased by controller type or tuning, apart from the requirement that the controller be linear.

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Gupta, Jatin. "Application of Hazard and Operability (HAZOP) Methodology to Safety-Related Scientific Software." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1398983873.

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Linh, Thi Thuy Vu. "An integrated approach for simultaneous operability and switchability analysis of chemical plants." Phd thesis, Department of Chemical Engineering, 1999. http://hdl.handle.net/2123/3968.

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Al-Ajooli, Samer Ata Qasim. "Operability and Optimum Control of the MEG Bench Scale and Distillation Plant." Thesis, Curtin University, 2019. http://hdl.handle.net/20.500.11937/78485.

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The sponsored bench-top scale mono-ethylene glycol pilot plant located at Curtin University was designed and operated to use realistic production fluids such as formation water/brine and condensate mixture to simulate conditions representative industrial MEG system. To achieve the optimum operating conditions, the performance results of MEG pre-treatment system has been thoroughly investigated in terms of emulsion tendencies, switchover between corrosion management strategies and alkalinity control.

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Dunjó, Denti Jordi. "New trends for conducting hazard & operability (HAZOP) studies in continuous chemical processes." Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/6481.

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Identifying hazards is fundamental for ensuring the safe design and operation of a system in process plants and other facilities. Several techniques are available to identify hazardous situations, all of which require their rigorous, thorough, and systematic application by a multi-disciplinary team of experts. Success rests upon first identifying and subsequently analyzing possible scenarios that can cause accidents with different degrees of severity. While hazard identification may be the most important stage for risk management, it depends on subjectivity issues (e.g., human observation, good judgment and intuition, creativity, expertise, knowledge) which introduce bias. Without a structured identification system, hazards can be overlooked, thus entailing incomplete risk-evaluations and potential loss. The present Thesis is focused on developing both managerial and technical aspects intended to standardize one of the most used techniques for hazard identification; viz. HAZard & Operability (HAZOP) study. These criteria have been carefully implemented not only to ensure that most of the hazardous scenarios will be identified, but also that US OSHA PSM Rule, EPA RMP, and Seveso Directive requirements will be accomplished. Chapter I pioneers the main research topic; from introducing the process safety concept up to the evidence of more detailed information is required from related regulations. A review of regulations (i.e., US, Europe legislation) focused on Hazard Identification has been conducted, highlighting, there is an absence of specific criteria for performing techniques intended to identify what can go wrong. Chapter II introduces the risk management system required to analyze the risk from chemical process facilities, and justifies that hazard identification stage is the Process Safety foundation. Hereafter, an overview of the key Process Hazard Analyzes (PHA) has been conducted, and the specific HAZOP weaknesses and strengths have been highlighted to establish the first steps to focus on. Chapter III establishes the scope, the purpose and the specific objectives that the research covers. It answers the following questions on the spot: why the present research is performed, which elements are included, and what has been considered for acquiring the final conclusions of the manuscript. Chapter IV gathers HAZOP-related literature from books, guidelines, standards, major journals, and conference proceedings with the purpose of classifying the research conducted over the years and finally define the HAZOP state-of-the-art. Additionally, and according to the information collected, the current HAZOP limitations have been emphasized, and thus, the research needs that should be considered for the HAZOP improvement and advance. Chapter V analyzes the data collected while preparing, organizing, executing and writing HAZOPs in five petroleum-refining processes. A statistical analysis has been performed to extract guidance and conclusions to support the established criteria to conduct effectively HAZOP studies. Chapter VI establishes the whole set of actions that have to be taken into account for ensuring a wellplanned and executed HAZOP study. Both technical and management issues are addressed, criteria supported after considering the previous chapters of the manuscript. Chapter VI itself is the result of the present research, and could be used as a guideline not only for team leaders, but also for any related party interested on performing HAZOPs in continuous chemical processes. Chapter VII states the final conclusions of the research. The interested parties should be released about the hazard identification related-gaps present in current process safety regulations; which are the key limitations of the HAZOP study, and finally, which are the criteria to cover the research needs that have been found Annex I proposes the key tools (tables, figures and checklists "ready-to use'') to be used for conducting HAZOPs in continuous chemical processes. The information layout is structured according to the proposed HAZOP Management System. This information is intended to provide concise and structured documentation to be used as a reference book when conducting HAZOPs. Annex II is intended to overview the most relevant petroleum refining processes by highlighting key factors to take into account in the point of view of process safety and hazard identification, i.e. HAZOP. In this sense, key health and safety information of specific petroleum refining units is provided as a valuable guidance during brainstorming sessions. Annex III illustrates the complete set of data collected during the field work of the present research, and also analyzed in Chapter V of the manuscript. Additionally, it depicts a statistical summary of the key variables treated during the analysis. Finally, the Nomenclature, References, and Abbreviations & Acronyms used and cited during the manuscript have been listed. Additionally, a Glossary of key terms related to the Process Safety field has been illustrated. La present Tesis doctoral té com a objectiu estandarditzar l'aplicació d'una de les tècniques més utilitzades a la industria de procés per a la identificació de perills; l'anomenat HAZard & OPerability (HAZOP) study, específicament a processos complexes, com per exemple, unitat de refineria del petroli. El capítol I defineix el concepte de Seguretat de Processos, i progressivament analitza les diferents regulacions relacionades amb la temàtica, detallant específicament les mancances i buits d'informació que actualment hi ha presents a la primera etapa de la gestió del risc en industries de procés: la identificació de perills. El capítol II defineix el sistema de gestió del risc tecnològic que aplica a les industries de procés, i es justifica que l'etapa d'identificació de perills és el pilar de tot el sistema. Finalment, es mencionen algunes de les tècniques d'identificació més utilitzades, els anomenats Process Hazard Analysis (PHA), i es detallen les seves mancances i fortaleses, característiques que han acabat definint la temàtica específica de la Tesis. Concretament, es dóna èmfasis a la tècnica anomenada HAZard & OPerability (HAZOP) study, objecte principal de la recerca. El capítol III defineix l'abast, el propòsit i els objectius específics de la recerca. La intenció d'aquest capítol és donar resposta a les següents qüestions: el perquè de la recerca, quins elements han estat inclosos i què s'ha considerat per tal d'assolir les conclusions de la Tesis. El capítol IV descriu l'estat de l'art de la literatura relacionada amb el HAZOP. Aquesta revisió no només permet classificar les diferents línies de recerca relacionades amb el HAZOP, sinó que també permet assolir un coneixement profund de les diferents particularitats de la pròpia tècnica. El capítol finalitza amb un conjunt de mancances tant de gestió com tècniques, així com les necessitats de recerca que poden millorar l'organització i execució dels HAZOPs. El capítol V analitza la informació que ha estat recopilada durant la fase experimental de la tesis. Les dades procedeixen de la participació en cinc estudis HAZOP aplicats a la industria de refineria del petroli. En aquest sentit, el capítol V desenvolupa una anàlisi estadística d'aquestes dades per extreure'n conclusions quant a la preparació, organització i execució dels HAZOPs. El capítol VI estableix el conjunt d'accions que s'ha de tenir en compte per tal d'assegurar que un estudi HAZOP estigui ben organitzat i executat (la metodologia). Es defineix un Sistema de Gestió del HAZOP, i a partir de les seves fases, es desenvolupa una metodologia que pretén donar suport a tots aquells punts febles que han estat identificats en els capítols anteriors. Aquesta metodologia té la intenció de donar suport i guia no només als líders del HAZOP, sinó també a qualsevol part interessada en aquesta temàtica. El capítol VII descriu les conclusions de la recerca. En primera instància s'enumeren les mancances quant a la definició de criteris a seguir de diferents regulacions que apliquen a la Seguretat de Processos. Seguidament, es mencionen les limitacions de la pròpia tècnica HAZOP, i finalment, es descriuen quins són els criteris establerts per donar solució a totes aquestes febleses que han estat identificades. L'Annex I és una recopilació de diferents criteris que han estat desenvolupats al llarg de l'escrit en forma de taules i figures. Aquestes han estat ordenades cronològicament d'acord amb les diferents fases que defineixen el Sistema de Gestió HAZOP. L'annex I es pot utilitzar com a una referència concisa i pràctica, preparada i pensada per ésser utilitzada directament a camp, amb la intenció de donar suport a les parts interessades en liderar estudis HAZOP. L'annex II recopila informació relacionada amb aspectes clau de seguretat i medi ambient en diferents unitats de refineria. Aquest informació és un suport per tal de motivar el "brainstorming" dels diferents membres que conformen l'equip HAZOP. L'Annex III recopila les dades de les diferents variables que han estat considerades a la fase experimental de la recerca, juntament amb un conjunt de figures que mostren la seva estadística bàsica.

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Morgan, Clifford Owen. "Development of computer aided analysis and design software for studying dynamic process operability." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/10187.

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Subedi, Pradeep. "Exploration of Erasure-Coded Storage Systems for High Performance, Reliability, and Inter-operability." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4463.

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With the unprecedented growth of data and the use of low commodity drives in local disk-based storage systems and remote cloud-based servers has increased the risk of data loss and an overall increase in the user perceived system latency. To guarantee high reliability, replication has been the most popular choice for decades, because of simplicity in data management. With the high volume of data being generated every day, the storage cost of replication is very high and is no longer a viable approach. Erasure coding is another approach of adding redundancy in storage systems, which provides high reliability at a fraction of the cost of replication. However, the choice of erasure codes being used affects the storage efficiency, reliability, and overall system performance. At the same time, the performance and interoperability are adversely affected by the slower device components and complex central management systems and operations. To address the problems encountered in various layers of the erasure coded storage system, in this dissertation, we explore the different aspects of storage and design several techniques to improve the reliability, performance, and interoperability. These techniques range from the comprehensive evaluation of erasure codes, application of erasure codes for highly reliable and high-performance SSD system, to the design of new erasure coding and caching schemes for Hadoop Distributed File System, which is one of the central management systems for distributed storage. Detailed evaluation and results are also provided in this dissertation.

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Bigi, Nedeleg. "Investigation of the dynamic motions and operability of a ship towed by kite." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0133/document.

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Afin de réduire les émissions de gaz à effet de serre et le coût du transport maritime, l'utilisation des cerfs-volants comme système de propulsion auxiliaire des navires est prometteuse. Pour estimer les performances et l’opérabilité d’un navire tracté par cerf-volant, une modélisation dynamique du système est alors mise en oeuvre. Une modélisation analytique de cerf-volant est utilisée. Ce modèle néglige la masse du cerf-volant et suppose que les lignes sont droites et indéformables. Ces hypothèses conduisent à un modèle cinématique dépendant du coefficient de portance et de la finesse aérodynamique. Une évolution linéaire des coefficients aérodynamiques en fonction de la courbure de la trajectoire de vol est proposée. Par ailleurs, en développant un modèle quasi analytique de ligne, il est montré qu’à partir de 2 m.s-1 de vent relatif que l’hypothèse de ligne droite est raisonnable. En se basant sur un modèle de ligne, un critère analytique de vitesse de vent minimum permettant un vol quasi-statique est présenté. Dans le but de résoudre l’ensemble des termes d’interaction entre le cerf-volant et le navire, un modèle linéarisé de tenue à la mer temporelle est développé. Le produit de convolution de la réponse impulsionnelle du navire est calculé avec des systèmes d’états. Cependant comme celle-ci représente mal les mouvements horizontaux des navires, le modèle développé est alors couplé à un modèle de manoeuvrabilité. Pour étudier les interactions entre le cerf-volant et le navire un couplage monolithique et un couplage dissocié sont comparés. Le couplage dissocié néglige l’influence des mouvements du navire sur le vol du cerf-volant. En cas de mer calme, les résultats obtenus par les deux types de couplage sont très proches. En cas de houle régulière les mouvements du navire sont principalement causés par la houle. Le couplage monolithique montre qu’un réseau de sous-harmoniques basse fréquence apparait alors dans le spectre d’excitation du navire. La fréquence fondamentale des sous-harmoniques est donnée par la différence entre la fréquence de vague et la fréquence de l’harmonique la plus proche de l’excitation du kite. Quand cette différence est suffisamment petite, un phénomène d’accrochage apparait. Ce phénomène est bénéfique pour le cerf-volant et le navire quand le décalage des harmoniques d'excitation correspond à une augmentation. Par ailleurs, une étude de la stabilité de route montre qu'il est nécessaire de contrôler activement le safran In order to reduce greenhouse gas emissions and shipping costs, the use of kites as an auxiliary propulsion device for ships is promising. In order to estimate the performance and the operability of a kite-towed vessel, a dynamic modeling of the system is implemented. A classical kite modeling is used. This model neglects the mass of the kite and assumes straight and inelastic tethers. These assumptions lead to a kinematic model depending on the lift coefficient and the aerodynamic lift to drag ration angle. A linear evolution of these aerodynamic coefficients as a function of the curvature of the flight path is proposed. In addition, by developing a quasi-analytical line model, it is shown that from 2 m.s-1 of relative wind the straight tether assumption is reasonable. Based on the tether model, an analytical criterion assessing the minimum wind speed to enable a quasi-static kite flight is developed. To solve all the interaction terms between the kite and the ship, a time domain seakeeping model based on the linearized ship equation of motion assuming a potential flow is developed. The convolution product of the impulse response of the ship is computed with state-space systems. However, since horizontal ship motions are not well represented by such theories, a coupling with a maneuvering model is presented.Comparisons to experimental data tests show good agreements. To study the interactions between the kite and the ship, a monolithic coupling and a dissociated coupling are compared. The dissociated coupling neglects the influence of ship motions on the kite flight. In a calm water case, results obtained by the two types of coupling are very close. In regular waves, ship motions are dominated by the wave influence. Thus, with the monolithic coupling, a network of low frequency subharmonic appears in the kite excitation spectrum. The fundamental frequency of the subharmonic is given by the difference between the wave frequency and the frequency of the nearest kite excitation harmonic. When this difference is small enough, a lock-in phenomenon appears. This phenomenon is a benefit for the kite and the ship when the shift of the excitation harmonics corresponds to an increase. Furthermore, a course keeping stability study shows that the rudder needs to be actively controlled

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Abrahamsen, Kristin Marheim, and Andreas Knudsen. "Reuse of experience in HazOp." Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-260.

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This report presents a study of the effect of reusing experience in the Hazards and Operability Analysis method (HazOp method) with regards to how the effectiveness of the method is affected. The study was conducted by first creating a software tool for experience reuse in HazOp, then testing that tool in a student experiment in which the participants used the tool when conducting a HazOp.During the experiment it was found that students using the tool found 21% more hazards in the system under study than their counterparts. After conducting the experiment it was found that there was a 94% certainty that this improvement was not due to random effects.

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Hattha, Wissanu. "Study on Berth Operability due to Met-Ocean Data in Upper Gulf of Thailand." Kyoto University, 2009. http://hdl.handle.net/2433/227598.

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Brodtkorb, Astrid Helene. "Dynamic Positioning in Extreme Sea States : Improving Operability Using Hybrid Design Methods ." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25840.

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This thesis investigates the performance of high-level hybrid dynamic positioning (DP) algorithms in extreme environmental conditions. A vessel in DP uses the thrusters as the sole means of keeping position in wind, waves and current, giving both flexible and accurate position keeping. Therefore vessels with DP capabilities are high in demand in industries like for instance the offshore, aquaculture, renewable energy industries and emerging fields like offshore mining. Due to high day rates the focus today is on developing DP systems for extending the operational window to even harsher environments, while keeping the solutions safe and environmentally friendly.When a sea state transitions from calm to extreme, the wind velocities increase generating higher and longer incident waves. This makes both horizontal and vertical relative motions of the vessel larger with longer periods of oscillation, which has consequences for the DP system onboard. Given the nature of a transitioning sea state, hybrid design methods are used to design a controller and an observer concept.A hybrid controller, for a vessel in a varying sea state is designed, and global asymptotic stability is established. Simulations in a sea state varying from calm to extreme are conducted with the hybrid controller, consisting of four candidate controllers, and a single controller with adaptive wave filtering for comparison. The single controller becomes unstable in extreme seas whereas the hybrid controller shows good performance. Candidate controllers are selected based on spectral analysis of the vessel wave frequency motions.A simplified sensor-based hybrid observer concept is investigated for noise robust position estimation. The concept assumes that acceleration measurements are readily available, and can be integrated to obtain position estimates. Position measurements are taken occasionally, and at these instances the position estimate is updated. Stability of the concept is analyzed giving uniform global asymptotic stability, and the simulation of two one degree of freedom sensor-based hybrid observers which rely on acceleration, velocity and position measurements is conducted.

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Wissanu, Hattha. "Study on Berth Operability due to Met-Ocean Data in Upper Gulf of Thailand." Doctoral thesis, Kyoto University, 2017. http://hdl.handle.net/2433/227598.

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全文ファイル差し替え（2021-06-07） 京都大学 0048 新制・課程博士 博士(工学) 甲第20675号 工博第4372号 新制||工||1680(附属図書館) 京都大学大学院工学研究科社会基盤工学専攻 (主査)教授平石哲也, 准教授馬場康之, 准教授森信人 学位規則第4条第1項該当 Doctor of Philosophy (Engineering) Kyoto University DFAM

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Woodward, Travis. "On the operability of the Sherritt-Gordon ammonia leach at the Kwinana nickel refinery." Thesis, Woodward, Travis (2014) On the operability of the Sherritt-Gordon ammonia leach at the Kwinana nickel refinery. PhD thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/28749/.

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The objective of this thesis was a study of the operability of the leaching process at the Kwinana nickel refinery. The refinery makes use of the Sherritt-Gordon process for producing London Metal Exchange-grade nickel briquettes and other products. Like all industrial operations, the refinery embodies a considerable investment, demanding optimal performance in order to remain profitable. The 3-stage, 6-autoclave ammonia leach there is the most important process in the refining operation, yet it is also the most complex and least understood. A thorough understanding of the leach is critical in promoting optimal refinery operation, thus provoking the present work. The operability study was conducted on the basis of mathematical modelling and computer simulation, focusing on steady-state operation. An examination of the chemistry of the Sherritt-Gordon ammonia leach was undertaken, leading to a chemical reaction system suitable for robust modelling. A mathematical model of the process was developed, which allowed for the construction of a computer program for the purpose of process simulation. The model was firstly used in a stand-alone fashion to examine the chemistry and operation of the leach. The model was secondly incorporated into an optimisation problem, augmenting the program as required, and used to investigate the impact of process disturbances and set-point changes on leach performance for a wide range of operating conditions. On a fundamental basis, the following transpired from this work: (1) a new understanding of the Sherritt-Gordon ammonia leach chemistry, (2) a novel method for modelling generic leaching reactors, and (3) a modelling framework for the Sherritt-Gordon ammonia leach. On a practical basis, the operability study of the ammonia leach generated (1) significant insight into process behaviour, which may be directly used by refinery staff to support performance optimisation and process control, and (2) a series of recommendations for unlocking hidden capacity, which should form the basis of future efforts to optimise refinery operation.

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Reed, Samuel Douglas. "Student Personal Concept Definition of Limits and Its Impact on Further Learning of Mathematics." Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1519125988967977.

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Stener, Patrik, and Robert Snabb. "Körbarhetskvantifiering av Hjullastare." Thesis, Linköping University, Department of Management and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11148.

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Idag är det möjligt att modellera de hydrauliska och mekaniska systemen hos en hjullastare. Det går även i viss omfattning att simulera omgivningen samt de förarkommandon som krävs för utförandet av en önskad uppgift. Däremot är det enda sättet att få reda på hur en förare kommer att uppleva maskinen, dess körbarhet, att bygga en fungerande prototyp och be en förare att testa den.Syftet med det här examensarbetet var att hitta en korrelation mellan förarens bedömningar och mätdata insamlade från en hjullastare under körning. Resultaten är sedan tänkta att användas i framtida simuleringar. Olika hjullastare testades av en grupp provförare och deras subjektiva bedömningar såväl som mätdata från hjullastarna samlades in.Slutsatsen är att det går till en viss del att förutsäga körbarheten från insamlade data om förarens körstil är känd. Då förarnas körstil skiljer väldigt mycket är det är inte möjligt att dra allmänna slutsatser om körbarheten. Today it is possible to model all hydraulic and mechanical systems of a wheel loader. To an extent the surrounding environment and the operator input required for a desired operation can also be simulated. However the only way to determine how an operator will perceive the handling qualities, the operability, of the wheel loader is to assemble a working prototype and ask an operator to try it out.The purpose of this Master thesis was to find some correlation between the drivers’ opinions and data recorded from the machines during operation. The results are intended to be used in future simulations. Different machines were tested by a group of drivers and their subjective impressions, as well as measurements from the machines were collected.The findings from the analysis are that the operability can be determined to a certain extent if the driver’s behaviour is known. Because of the differences in the way the drivers operate the machine it has not been possible to draw any general conclusions.

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35

Dyer, Matthew Simon 1972. "A multiscale approach to state estimation with applications in process operability analysis and model predictive control." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/16749.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2000. Includes bibliographical references. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. This thesis explores the application of multiscale ideas to the areas of state estimation and control. The work represents a significant departure from the traditional representations in the time and frequency domains, and provides a novel framework that leads to fast, efficient, and modular estimation algorithms. Multiscale methods were rediscovered through wavelet theory in the mid-eighties, as a tool for the geophysics community. Like Fourier theory, it provides a more instructive representation of data than time series alone, by decomposition into a different set of orthonormal basis functions. Multiscale models and data sets exist on multiscale trees of nodes. Each node represents a place holder corresponding to a time point in a time series. The nodes of a tree form a structure which may contain measurements, states, inputs, outputs, and uncertainties. Each level of the tree represents the set of data at a given level of resolution. This dual localization in time and frequency has benefits in the storage of information, since irrelevant data and pure noise can be identified and discarded. It also preserves time and frequency information in a way that Fourier theory cannot. Grouping and condensing of important information follows naturally, which facilitates the making of decisions at a level of detail relevant to the question being asked. Multiscale systems theory is a general approach for multiscale model construction on a tree. This thesis derives the multiscale models corresponding to the Haar transform, which produces a modified hat transform for input data. Autoregressive models, commonly used in time series analysis, give rise to multiscale models on the tree. These allow us to construct numerical algorithms that are effcient and parallelizable, and scale logarithmically with the number of data points, rather than the linear performance typical for similar time-series algorithms. This multiscale systems theory generalizes easily to other wavelet bases. Multiscale models of the underlying physics and the measurement model can be combined to construct a cost function which estimates the underlying physical states from a set of measurements. The resulting set of normal equations is sparse and contains a specialized structure, leading to a highly efficient solution strategy. A modified multiscale state estimation algorithm incorporates prior estimates, consistent with the Kalman filter, with which it is linked. A constrained multiscale state estimator incorporates constraints in the states, and in linear combinations of the states. All incarnations of the multiscale state estimator provide a framework for the optimal fusion of multiple sets of measurements, including those taken at different levels of resolution. This is particularly useful in estimation and control problems where measurement data and control strategies occur at multiple rates. The arbitrary size of the state allows for the use of higher order underlying physical models, without modification of the estimation algorithm. Finally, the algorithm accommodates an arbitrary specification of the uncertainty estimates at any combination of time points or level of resolution. The structure of the solution algorithm is sufficiently flexible to use the same intermediate variables for all of these modifications, leading to considerable reusability, both of code, and of prior calculations. Thus, the multiscale state estimation algorithm is modular and parallelizable. An uncertainty analysis of the algorithm represents state estimation error in terms of the underlying model and measurement uncertainties. Depending on the size of the problem, different techniques should be used to construct the probability distribution functions of the error estimates. This thesis demonstrates direct integration, propagation of the moments of the measurement and model errors, polynomial chaos expansions, and an approximation using Gaussian quadrature and Monte Carlo simulation. A sample of smaller case studies shows the range of uses of the algorithm. Three larger case studies demonstrate the multiscale state estimator in realistic chemical engineering examples. The terephthalic acid plant case study successfully incorporates a non-linear model of the first continuously stirred tank reactor into the multiscale state estimator. The paper-rolling case study compares the multiscale state estimator to the Karhunen-Loeve transform as a means of state estimation. Finally, the heavy oil fractionator of the Shell Control Problem demonstrates the multiscale state estimator in a control setting. by Matthew Simon Dyer. Ph.D.

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Frank, Owajionyi L. "Exploring a best practice approach to operability and maintainability of low carbon buildings in the UK." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/13923/.

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Growth in technological advancement was to humanity a mixed blessing. While it provided comfort and improved quality of life, it also increased the demand for energy to drive them. This increase in energy usage, particularly from fossil fuel sources is widely understood to be responsible for the critical environmental problems in the world (Climate Change). Mitigating and adapting to this anthropogenic induced consequence created the need for varying innovative and new low carbon and renewable technologies which are gradually replacing the traditional high fossil fuel driven systems in buildings. Presently in the UK, every new building is expected to be low carbon and energy efficient; operated in such a manner as to use no more fuel and power than is reasonable in the circumstances. However, it is widely believed that construction underperforms in terms of capacity to deliver value. Clients and end-users of these buildings appear not to be getting long term value for their investments. Much attention has also not been given to how these new and innovative technologies can be operated and maintained long into the future. Recent researches also underpin the fact that the wide information gap existing between designers and building end-users is one of the factors responsible for the underperformance. This research therefore sought to explore a best practice approach that could bridge this information gap, and ensure that low carbon buildings are efficiently operated and maintained long into the future, particularly as the UK built environment moves closer to its zero carbon targets of 2016 and 2019. The research methodology involved triangulation (a mixed-method research approach), thus maximising the chances of benefiting from the strength of each of qualitative and quantitative methods. Interviews, surveys and case studies were employed. Post occupancy evaluation method was also used for the key case study. Findings indicate that there is a need for change in the way low carbon buildings are delivered to the end-users; that a properly prepared operation and maintenance (O&M) manual is indispensable in the effective and efficient operation and maintenance of low carbon buildings, and that it will be good practice to bring in the O&M team early to the design process. The study also suggested that designers be required to prove ‘life-cycle operability and maintainability’ of their designs before they are constructed. To ensure this desired cultural and process change in project delivery, a Maintainability and Operability Integrated (OMI) Design and Construction Process Model is proposed. The model was developed using the proposed RIBA 2013 revised Outline Plan of Work and drawing lessons from the New Product Development (NPD) process used by the manufacturing sector and other construction industry models. A validation test was conducted by means of a focus group, populated by top management officials of the University of Nottingham Estates Office, which has been actively involved in the procurement and management of myriads of low carbon buildings. Feedbacks from the validation test indicate that the proposed OMI Process Model was a well thought out idea which is practicable and capable of addressing the shortfall within the existing processes to deal with the O&M issues raised by the use of new and innovative low carbon technologies.

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Addy, Nicholas G. "Ontology driven geographic information retrieval." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/2526.

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The theory of modern information retrieval processes must be improved to meet parallel growth and efficiency in its dependent hardware architectures. The growth in data sources facilitated by hardware improvements must be conversant with parallel growth at the user end of the information retrieval paradigm, encompassing both an increasing demand for data services and a widening user base. Contemporary sources refer to such growth as three dimensional, in reference to the expected and parallel growth in the key areas of hardware processing power, demand from current users of information services and an increase in demand via an extended user base consisting of institutions and organizations who are not characteristically defined by their use of geographic information. This extended user base is expected to grow due to the demand to utilise and incorporate geographic information as part of competitive business processes, to fill the need for advertising and spatial marketing demographics. The vision of the semantic web as such is the challenge of managing integration between diverse and increasing data sources and diverse and increasing end users of information. Whilst data standardisation is one means of achieving this vision at the source end of the information flow, it is not a solution in a free market of ideas. Information in its elemental form should be accessible regardless of the domain of its creation.In an environment where the users and sources are continually growing in scope and depth, the management of data via precise and relevant information retrieval requires techniques which can integrate information seamlessly between machines and users regardless of the domain of application or data storage methods. This research is the study of a theory of geographic information structure which can be applied to all aspects of information systems development, governing at a conceptual level the representation of information to meet the requirements of inter machine operability as well as inter user operability. This research entails a thorough study of the use of ontology from theoretical definition to modern use in information systems development and retrieval, in the geographic domain. This is a study examining how the use of words to describe geographic features are elements which can form a geographic ontology and evaluates WordNet, an English language ontology in the form of a lexical database as a structure for improving geographic information recall on Gazetteers. The results of this research conclude that WordNet can be utilised to as a methodology for improving search results in geographic information retrieval processes as a source for additional query terms, but only on a narrow user domain.

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Ємельяненко, Сергій Сергійович, Сергей Сергеевич Емельяненко, Serhii Serhiiovych Yemelianenko та Б. Я. Гайда. "Способ закрепления осевого инструмента и его влияние на работоспособность и точность обработки". Thesis, Сумский государственный университет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45849.

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Современное металлорежущие оборудование обеспечивает требуемую экономическую эффективность при условии использования прогрессивного режущего инструмента. Но в тоже время режущий инструмент невозможно эксплуатировать с задаными режимами резания без приминения для его крепления специальной инструментальной оснастки, которая определяет точность обработки, производительность обработки и стойкость инструмента.

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39

Басенко, В. Н., Станіслав Володимирович Швець, Станислав Владимирович Швец та Stanislav Volodymyrovych Shvets. "Заточка спиральных сверл". Thesis, Сумский государственный университет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46844.

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Для создания заднего угла на главной задней поверхности ее затачивают, придавая ей форму различных поверхностей. Это может быть конус (при схемах заточки Вашбурна или Вейскера), цилиндр, плоскость, сфера, винтовая поверхность [1- 4].

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40

Blauser, David J. Jr. "Human factors engineering and operability in the design of Electronic Warfare spaces aboard United States Naval combatants." Thesis, Piscataway, N.J. : IEEE Press ; Hoboken, N.J. : Wiley, 1985. http://hdl.handle.net/10945/21366.

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41

ZENG, JUQIN. "SYNTHESIS AND CHARACTERIZATION OF NEW ELECTROCATALYTIC MATERIALS TO IMPROVE THE PERFORMANCE, OPERABILITY AND LIFE-TIME OF PEMFCS." Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2497100.

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Low-temperature fuel cells have been becoming important as an environment- friendly technology and are acquiring considerable interest in both research and commercial purposes. However, several limitations such as lifetime, reliability and cost are hindering the commercialization of these systems. The enhancement of catalytic activity and durability of catalysts represents one of the most important issues in fuel cell technology. To increase the performace and decrease the load of the catalysts, materials with high surface area and pore volume, commonly carbons, are widely used as catalyst supports in low-temperature fuel cells. The support materials can enhance the dispersion of metal particles. In addition, an interaction effect between the support material and the metal exists. It could change the activity of catalytic sites on the metal surface and modify the number of active sites by both electronic effect and geometric effect. The supports such as tungsten trioxide (WO3) may bring its own (electro)chemical function for oxygen reduction reaction (ORR), methanol or CO oxidation. What’s more, the support materials can also influence the durability of the catalysts. The development of promising and new catalyst surports, therefore, is significantly vital for improving the electrochemical activities and stabilities of the catalysts. The present work focuses on the investigation of new catalyst supports in order to improve the performace of the catalysts. In addition, the durability issue in freezing condition is also studied. In the introductory section, two chapters are included. In chapter 1, the history and different fuel cell types are reviewed. The basic principles of the fuel cell reactions, both the thermodynamic considerations as well as the kinetic aspects, are discussed. Chapter 2 focuses on proton exchange membrane fuel cells (PEMFCs), including the oxygen reduction and hydrogen oxidation reactions, the various materials and components in the PEMFCs, the durability issues of the material and PEMFCs, the applications of PEMFCs and the challenges in the further development. Thereinto, the catalyst supports, especially the carbon supports, and the durability of carbon supported catalysts are discussed in details. In the experimental section, the methods of synthesizing the materials are summarized, including mesoporous silica, mesoporous carbon as well as carbon supported catalysts. The synthesis details of the samples prepared and the experimental methods employed in the work are also described. The structural and morphological characterization tools include: scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), Nitrogen physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The electrochemical methods are: cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements. The inductively coupled plasma (ICP) used for quantitative elemental analysis is also briefly described. In addition, the preparation of membrane electrode assembly (MEA) and the operation of a single fuel cell are also presented. The third section presents the results and discussion of the work. This thesis deals with three kinds of mesoporous carbons as catalyst supports. One kind is ordered mesoporous carbons (OMC) which is discussed in chapter 5. Another kind is a disordered mesoporous carbon, namely hollow core mesoporous shell carbon (HCMSC), which is presented in chapter 6. The chapter 7 describes the WO3 modified ordered mesoporous carbon (OMC: CMK-3) as catalyst supports for oxygen reduction and methanol oxidation reactions. In addition, the experimental studies on Nafion® 112 single PEMFCs exposed to freezing conditions are specified in chapter 8. In chapter 5, three ordered mesoporous carbons supported Pt catalysts (10 wt. % Pt/ OMCs) are synthesized and characterized. The electrochemical performances and durability properties of the Pt/ OMCs are measured in acidic solution at room temperature by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The catalytic activities of the Pt/ OMCs toward oxygen reduction reaction are also tested at the cathode of a complete polymer electrolyte fuel cell setup. Subsequently, the polarization curves obtained in the fuel cell are analyzed by means of a simplified model and important parameters about the catalytic layer are obtained. A comparative discussion of these results indicated the electrochemical performances of the Pt/ OMCs strongly depend on the pore structure of the OMCs. Chapter 6 deals with a mesoporous carbon synthesized with a novel procedure. The Pt catalyst supported on this carbon (20 wt. % Pt/ HCMSC) is physically and electrochemically characterized. The CV method is employed to evaluate the electrochemical active surface area (EAS) and durability of the Pt/ HCMSC catalyst. In CV and LSV tests, the electrocatalytic activities of Pt/ HCMSC toward methanol oxidation and oxygen reduction reaction are tested and compared with commercial 20 wt. % Pt/ C catalyst. Chapter 7 deals with carbon-WO3 composite supported Pt catalysts. WO3 was deposited on ordered mesoporous carbon (OMC: CMK-3) by impregnation of phosphotungstic acid (PWA) and subsequent annealed in N2 atmosphere. The WO3 modified ordered mesoporous carbons (MC-WO3) retained the ordered mesostructure, high BET specific surface area and large pore volume. The MC-WO3 supported Pt catalysts (Pt/ MC-WO3) were prepared by wet impregnation. According to the results of electrochemical tests of CV and LSV, the catalytic activity of the supported catalysts was dependent on the nature of the supporting materials, including the structure and particle size of WO3 particles. Chapter 8 presents the phenomena of PEMFCs when exposed to sub-freezing conditions. In particular, the analysis is focused on the effects of suitable dehydration processes (purging procedures) on MEAs prepared with Nafion® 112, before exposing them to various freezing/ thawing (F/ T) cycles: both electrochemical performance and mechanical stresses are considered, in order to verify the effectiveness of the dehydration processes in avoiding cracks and maintaining thus a satisfactory FC performance (limited decay of the polarization curve). Purging procedures with N2, air and H2 are considered to investigate the effect of the purging gases to the MEAs performance.

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42

Campher, Andre Herman. "A systematic approach to model predictive controller constraint handling : rigorous geometric methods." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/28378.

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The models used by model predictive controllers (MPCs) to predict future outcomes are usually unconstrained forms like impulse or step responses and discrete state space models. Certain MPC algorithms allow constraints to be imposed on the inputs or outputs of a system; but they may be infeasible as they are not checked for consistency via the process model. Consistent constraint handling methods - which account for their interdependence and disambiguate the language used to specify constraints – would therefore be an attractive aid when using any MPC package. A rigorous and systematic approach to constraint management has been developed, building on the work of Vinson (2000), Lima (2007) and Georgakis et al. (2003) in interpreting constraint interactions. The method supports linear steady-state system models, and provides routines to obtain the following information: <ul> <li> effects of constraint changes on the corresponding input and output constraints, </li><li> feasibility checks for constraints, </li><li> specification of constraint-set size and</li><li> optimal fitting of constraints within the desirable input and output space.</li></ul> Mathematical rigour and unambiguous language for identifying constraint types were key design criteria. The outputs of the program provide guidance when handling constraints, as opposed to rules of thumb and experience, and promote understanding of the system and its constraints. The metrics presented are not specific to any commercial MPC and can be implemented in the user interfaces of such MPCs. The method was applied to laboratory-scale test rigs to illustrate the information obtained. Dissertation (MEng)--University of Pretoria, 2011. Chemical Engineering unrestricted

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43

Bonanos, Aristides Michael. "Scramjet Operability Range Studies of an Integrated Aerodynamic-Ramp-Injector/Plasma-Torch Igniter with Hydrogen and Hydrocarbon Fuels." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28847.

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An integrated aerodynamic-ramp-injector/plasma-torch-igniter of original design was tested in a Mâ = 2, unvitiated, heated flow facility arranged as a diverging duct scramjet combustor. The facility operated at a total temperature of 1000 K and total pressure of 330 kPa. Hydrogen (H2), ethylene (C2H4) and methane (CH4) were used as fuels, and a wide range of global equivalence ratios were tested. The main data obtained were wall static pressure measurements, and the presence of combustion was determined based on the pressure rises obtained. Supersonic and dual-mode combustion were achieved with hydrogen and ethylene fuel, whereas very limited heat release was obtained with the methane. Global operability limits were determined to be 0.07 < Ï < 0.31 for hydrogen, and 0.14 < Ï < 0.48 for ethylene. The hydrogen fuel data for the aeroramp/torch system was compared to data from a physical 10Âº unswept compression ramp injector and similar performance was found with the two arrangements. With hydrogen and ethylene as fuels and the aeroramp/plasma-torch system, the effect of varying the air total temperature was investigated. Supersonic combustion was achieved with temperatures as low as 530K and 680K for the two fuels, respectively. These temperatures are facility/operational limits, not combustion limits. The pressure profiles were analyzed using the Ramjet Propulsion Analysis (RJPA) code. Results indicate that both supersonic and dual-mode ramjet combustion were achieved. Combustion efficiencies varied with Ï from a high of about 75% to a low of about 45% at the highest Ï . With a theoretical diffuser and nozzle assumed for the configuration and engine, thrust was computed for each fuel. Fuel specific impulse was on average 3000 and 1000 seconds for hydrogen and ethylene respectively, and air specific impulse varied from a low of about 9 sec to a high of about 24 sec (for both fuels) for the To = 1000K test condition. The GASP RANS code was used to numerically simulate the injection and mixing process of the fuels. The results of this study were very useful in determining the suitability of the selected plasma torch locations. Further, this tool can be used to determine whether combustion is theoretically possible or not. Ph. D.

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Lim, Hankwon. "Studies of the Ethanol Steam Reforming Reaction in a Membrane Reactor." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29675.

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The subject of this dissertation is advanced inorganic membranes and their application in membrane reactors (MRs). The reaction studied is the ethanol steam reforming (ESR) reaction using Co-Na/ZnO catalysts, chosen because of their high activity and stability. The Co-Na/ZnO catalysts were prepared by a co-precipitation method and it was found that promotion with a moderate amount of Na (1.0 wt%) produced a catalyst with stable ethanol conversion and product selectivity. Higher cobalt loading, higher W:E ratio, higher reaction temperature, and lower space velocity enhanced the conversion of ethanol to H2 and CO2 while reducing the formation of undesirable acetaldehyde. Acetaldehyde was a primary product of the ESR reaction. Studies of the effect of hydrogen permeance on the ESR reaction at 623 K were performed in MRs equipped with silica-based and palladium-based membranes of different hydrogen permeances, and the highest ethanol conversion enhancement of 44 % and hydrogen molar flow enhancement of 69 % compared to a packed-bed reactor (PBR) were obtained in a MR fitted with a membrane with the highest hydrogen permeance. An operability level coefficient (OLC), defined as the ratio of the hydrogen permeation and hydrogen formation rates, was suggested as a useful tool for estimating performances of MRs for different reforming reactions such as methane dry reforming (MDR), methane steam reforming (MSR), methanol steam reforming (MeSR), and ethanol steam reforming (ESR) reactions. Studies of the effect of pressure (1-10 atm) on the ESR reaction at 623 K were carried out in a PBR and a MR fitted with a Pd-Cu membrane prepared by an electroless plating of palladium and copper at 333 K. Comparison studies showed that increasing pressure in both reactors resulted in decreasing ethanol conversions and increasing hydrogen molar flows. Compared to the PBR, higher ethanol conversions and hydrogen molar flows were obtained in the MR for all pressures studied. Increasing pressure was favorable for enhancing ethanol conversion and hydrogen molar flow in the MR compared to the PBR, and the highest ethanol conversion enhancement of 48 % with the highest hydrogen molar flow enhancement of 55 % was obtained at 10 atm in the MR. Ph. D.

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Столяренко, Н. Н., К. Н. Столяренко та В. С. Борода. "Методика комплесных упражнений, как основной метод для повышения резистентоности сердечно-сосудистой системы к физическим нагрузкам у детей младшего школьного возраста". Thesis, Сумский государственный университет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/48130.

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Целью данной работы является усовершенствование методики оценки работоспособности сердца при физических нагрузках и создание комплексов упражнений для повышения его резистентности к физическим нагрузкам детей младшего школьного возраста. Для выполнения поставленных задач использовались ниже перечисленные методы исследования: анкетирование по системе «сбор анамнеза», ряд функциональных проб: проба Генча, Штанги, Руфье, модифицированная проба Мартинета.

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Сенцова, А. А. "Дія невагомості, сили тяжіння та перевантаження на організм людини". Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/43929.

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47

Haghverdian, Pol, and Martin Olsson. "Identification of cloud service use-cases and quality aspects:end-user perspective : Learnability, Operability and Security quality attributes and their corresponding use cases." Thesis, Blekinge Tekniska Högskola, Institutionen för programvaruteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-12753.

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Context. With the entry of smart-phones on the market in the beginningof 2007, the integration of an mp3 player, camera and gps into an all in onedevice. As the integration was realized, creating and storing own contentbecame easier. Therefore the need of more storage became a problem as thesmart-phones were limited in capacity. The 3G network was on the rise andthe cloud solutions could help to contribute to the storage problems usersstarted to have. Objectives. In this study we will evaluate what can be done with use casesin terms of quality attributes, seeing it from a users perspective by havingusers rank use cases for cloud services. With further investigation we willmake a contribution of what the differences between public and personalclouds are. Methods. Use-cases were found by the conducted empirical study andwere based on a Systematic mapping review. In this review, a number ofarticle sources are used, including Google search, Bth summon and Googlescholar. Studies were selected after reading the articles and checked if thepapers matched our defined inclusion criteria. We also designed a surveywith variable amount of questions depending on what the participant wouldanswer. The questions were featured in terms of functionality interpretedfrom the use-cases found in the SLM. Results. Through our SLM we found six different use-cases which were Recovery, Collaborative working, Password protection, Backup, Version tracking and Media streaming. The identified quality attributes gave two or moremappings to their corresponding use-case. As for the comparison betweendifferent clouds, only two out of six use-cases where implemented for the Personal cloud. Conclusions. This gave us the conclusion that the vendors have beenmostly focusing on the storage part of the Personal cloud, but there are solutions in order to increase the functionalities. Those solutions will probably not fit everyone as it includes open source software, with skills of handling installation and other procedures by the user.

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Casarosa, L. "The integration of human factors, operability and personnel movement simulation into the preliminary design of ships utilising the Design Building Block approach." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1324518/.

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This thesis presents the feasibility, advantages and impact on Preliminary Ship Design of an approach to integrate ship configurational design with the modelling and simulation of a range of crewing issues, such as operations and evacuation. Integrating personnel movement simulation into preliminary ship design introduces the assessment of onboard operations at the front-end of the design process, informing the design and enabling improved operability while the design is still amenable to changes. The approach to accomplish this integration is discussed with the aim of informing all parties involved in the design of ships with regard to the main aspects of personnel operability and on board safety. The research was undertaken as part of a three years research project funded by the Engineering and Physical Sciences Research Council (EPSRC) entitled “Guidance on the Design of Ships for Enhanced Escape and Operation”. The project aimed at bringing together the University of Greenwich developed “maritimeEXODUS” personnel movement simulation software and the SURFCON implementation in the PARAMARINE suite of the Design Building Block approach to Preliminary Ship Design, which originated with the UCL Ship Design Research team. The approach and procedural implications of integrating personnel movement simulation into the preliminary ship design process are presented through a series of SURFCON ship design case studies. With the UK Ministry of Defence as the industrial partner to the project, this study on “design for operation” concentrates on naval vessels, which provide excellent examples of complex environments. Design studies, based on the Royal Navy Type 22 Batch III Frigate design, were analysed using PARAMARINE, maritimeEXODUS and bespoke interface software produced by the candidate. Technical aspects of the development of the interface software are discussed from a procedural perspective, focusing on integration and usability issues. The discussion addresses alternative options to visualising the simulation results and how to integrate into a ship design model a minimum level of detail sufficient to conduct simulations able to inform the designer, while retaining the flexibility the design requires in early stages design. The thesis concludes by summarising the opportunities that integrating operational simulation into preliminary ship design opens up for the future practice of ship design, contributing to the debate on the nature of ship design and of Computer Aided Preliminary Ship Design.

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Dhingra, Manuj. "Compressor stability management." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-01102006-174943/.

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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2006. Prasad, J.V.R., Committee Chair ; Neumeier, Yedidia, Committee Member ; Seitzman, Jerry, Committee Member ; Sankar, Lakshmi, Committee Member ; Wadia, Aspi, Committee Member.

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Gutiérrez, Flores José Leonardo. "Nueva Central Operativa de Emergencias para la Policía Nacional del Perú." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/625997.

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El proyecto pretende desde el punto de vista arquitectónico, brindar a los efectivos policiales espacios de mejor calidad para desarrollar sus actividades operativas y de capacitación constante. Además, busca dignificar la labor policial y generar infraestructura que vaya de acuerdo al profesionalismo propio de la actividad de patrullaje, monitoreo y prevención del delito dentro de nuestra ciudad. El diseño de esta arquitectura genera espacios seguros considerando la operatividad y controlando riesgos externos e internos. Esta espacialidad busca reflejar la calidad del servicio policial hacia la comunidad y sobre todo que el usuario se sienta identificado con la nueva imagen moderna que se le quiere dar a la institución. Todo esto, sin perder la correcta funcionalidad de una central de monitoreo y emergencias, la cual se debe mantener como una variable debido a su nivel de complejidad. Investigando la experiencia internacional en complejos policiales, he logrado identificar que la incorporación, muy bien sectorizada y definida, de ambientes destinados a la integración de la comunidad benefician a los usuarios al permitirle reflejar una nueva imagen de confianza y seguridad que se le quiere dar a la ciudad a la que sirven y protegen. Estos ambientes están diseñados de manera que no afecten la operatividad y niveles de seguridad que permitan vulnerar el complejo policial. Por otro lado, el diseño de un gran espacio central dentro del complejo genera un orden esencial que permite controlar las circulaciones y sectorizar el complejo por funciones y actividades tanto administrativas como operativas, servicio y atención ciudadana. Es por esta razón, que decidí incorporar esta visión de nueva central operativa de emergencias, adaptándome a preceptos modernos e imagen reciente que pretende reflejar la Policía Nacional y extranjera. The project aims from the architectural point of view, to provide police officers with better quality spaces, to develop their operational activities and training. In addition, it seeks to dignify the police work and create an infrastructure that goes with the professionalism of patrolling, monitoring and preventing crime in our city. The design of this architecture creates safe spaces considering the operations and controlling external and internal risks. This space seeks to show the quality of the police service towards the community, and above all, the users will feel identified with the new modern image that is meant to contribute to the institution. All of this, without losing the correct functionality of a monitoring and emergencies center, which must be maintained as a variable due to its level of complexity. Investigating the international experience in police centers, I have been able to identify that the incorporation, well sectorized and defined of environments destined to the participation of the community, benefits the users by allowing them to reflect the new image of confidence and security that they want to present to the city they serve and protect. These environments are designed in such way that they don´t affect the operations and levels of security that allows to trespass the police center. On the other hand, the design of a large central space generates an essential order that allows to control circulation and sectorize the building by functions and activities, both, administrative and operational, service and citizen attention. It is for this reason that I decided to incorporate the vision of a new operational emergency center, adapting it to modern precepts and a brand-new image that the National and Foreign Police aims to reflect. Tesis

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Dissertations / Theses on the topic 'Operability'

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