Precipitation in the form of heavy rainfall events is of significant societal concern, not only due to the potential for more frequent flash floods, after evidence of changes in rainfall characteristics has recently strengthened. Despite the importance of individual rainfall events with respect to many hydrological applications, only a few studies dealt with characteristics of individual rainfall events (in contrast with the other daily/sub-daily indices of rainfall depths/intensities). Dissertation thesis presents a comprehensive analysis of heavy rainfall event characteristics for the Czech Republic derived from observed data and large ensemble of regional climate model (RCM) simulations. In addition, spatial correlation structure of observed rainfall data at a mesoscale region of north-eastern Bohemia was analysed. Since an RCM grid box represents a spatial average rather than a point measurement, the effects from areal averaging of rainfall data on characteristics of events were investigated considering the observed data. Characteristics of rainfall events were evaluated according to several indices against the at-site and area-averaged observed data for the control period 1981-2000. The changes of rainfall event characteristics were assesed over two scenario periods (2020-2049 and 2070-2099) with respect to control period. We analysed also relations between changes in simulated rainfall event characteristics and changes in radiative forcing and temperature.

O atual ambiente competitivo, onde baixo custo, alta qualidade e um grau crescente de customização são exigências para a sobrevivência das empresas, tem influenciado as ações dos profissionais de manutenção com vistas ao aprimoramento das políticas de manutenção. Como resultado, tem-se na área de manutenção industrial, uma grande quantidade de métodos, software, modelos e ferramentas de gestão disponíveis. Dentre eles, dois métodos se destacam: o RCM (Reliability Centered Maintenance ou Manutenção Centrada em Confiabilidade), de origem norte-americana, e a TPM (Total Productive Maintenance ou Manutenção Produtiva Total), de origem japonesa. A TPM promove a integração total entre homem, máquina e empresa, onde a manutenção dos meios de produção passa a constituir uma responsabilidade de todos. A utilização da TPM contempla a implementação de pilares de sustentação, sendo um deles, a manutenção planejada. Entretanto, a TPM não especifica a estratégia a ser adotada pela manutenção planejada. O RCM é uma metodologia lógica de procedimentos que objetiva estabelecer uma manutenção preditiva e preventiva para alcançar, de maneira efetiva e eficiente, os níveis de segurança e confiabilidade requeridas para cada equipamento. Considerando um ambiente com a TPM já implementada, o objetivo deste trabalho é a melhoria do pilar Manutenção Planejada da TPM através da utilização do RCM para nortear as estratégias de manutenção em empresas industriais. A sistemática proposta é ilustrada através de um estudo de caso na indústria de conformação de metais. / Today’s competitive business environment, in which low costs, high quality and an ever increasing degree of customization are essential for companies’ survival has influenced maintenance professionals’ courses of action, aiming at improving maintenance policies. As a result, in the industrial maintenance sector there is a great number of methods, software and management tools available. Among them, two stand out: the RCM (Reliability Centered Maintenance), a North American approach, and the TPM (Total productive Maintenance), a Japanese approach. TPM promotes total integration among manpower, machines and the company itself, and the maintenance of the means of production is everybody’s responsibility. The introduction of TPM demands the implementation of the so called sustaining pillars, and planned maintenance is one of them. However, TPM does not specify the strategy to be followed by planned maintenance. RCM is a set of logical procedures aiming at setting up predictive and preventive maintenance in order to effectively and efficiently achieve the security and reliability standards required for each equipment. Considering an environment where TPM has already been implemented, this paper aims at optimizing Planned Maintenance of the TPM by using RCM to guide maintenance strategies in industries. The system proposed is illustrated through a case study in a metal cold roll forming factory.

La presente investigación está centrada en hacer una gestión de mantenimiento centrado en la confiabilidad de la estación de bombeo N°1 de la planta de tratamiento N°1 de agua potable de Chiclayo en la Empresa EPSEL S.A., dicha empresa brinda el servicio de agua potable y alcantarillado a toda la región y con el fin de lograr un aumento de la producción en el servicio de agua potable en la ciudad de Chiclayo se decidió por el desarrollo de esta gestión. En primer lugar se procedió a realizar un diagnóstico situacional de la estación de bombeo con el fin de identificar los principales problemas que acarrean a este sistema. Dicha estación cuenta con un número elevado de averías lo que ocasionan detención en la producción y distribución. Posteriormente se definió las teorías y normativas que permitieron el desarrollo correcto de la aplicación de este mantenimiento, como lo son el análisis de criticidad, diagrama causa efecto, análisis de modo y de falla y distribución de Weibull entre otros; para luego, definir el plan de gestión a aplicar basado en el mantenimiento centrado en la confiabilidad, y en última instancia se realizó un análisis costo-beneficio de la propuesta que nos permitirá conocer la viabilidad del proyecto. A través del cumplimiento de los objetivos propuestos se logrará obtener la confiabilidad de los equipos pertenecientes a dicha estación de bombeo, incluyendo las herramientas y métodos utilizados para el establecimiento de la gestión de mantenimiento de la misma, consiguiendo a través de estos mejorar la producción de agua potable y la generación de ahorro. / Tesis

O atual ambiente competitivo, onde baixo custo, alta qualidade e um grau crescente de customização são exigências para a sobrevivência das empresas, tem influenciado as ações dos profissionais de manutenção com vistas ao aprimoramento das políticas de manutenção. Como resultado, tem-se na área de manutenção industrial, uma grande quantidade de métodos, software, modelos e ferramentas de gestão disponíveis. Dentre eles, dois métodos se destacam: o RCM (Reliability Centered Maintenance ou Manutenção Centrada em Confiabilidade), de origem norte-americana, e a TPM (Total Productive Maintenance ou Manutenção Produtiva Total), de origem japonesa. A TPM promove a integração total entre homem, máquina e empresa, onde a manutenção dos meios de produção passa a constituir uma responsabilidade de todos. A utilização da TPM contempla a implementação de pilares de sustentação, sendo um deles, a manutenção planejada. Entretanto, a TPM não especifica a estratégia a ser adotada pela manutenção planejada. O RCM é uma metodologia lógica de procedimentos que objetiva estabelecer uma manutenção preditiva e preventiva para alcançar, de maneira efetiva e eficiente, os níveis de segurança e confiabilidade requeridas para cada equipamento. Considerando um ambiente com a TPM já implementada, o objetivo deste trabalho é a melhoria do pilar Manutenção Planejada da TPM através da utilização do RCM para nortear as estratégias de manutenção em empresas industriais. A sistemática proposta é ilustrada através de um estudo de caso na indústria de conformação de metais. / Today’s competitive business environment, in which low costs, high quality and an ever increasing degree of customization are essential for companies’ survival has influenced maintenance professionals’ courses of action, aiming at improving maintenance policies. As a result, in the industrial maintenance sector there is a great number of methods, software and management tools available. Among them, two stand out: the RCM (Reliability Centered Maintenance), a North American approach, and the TPM (Total productive Maintenance), a Japanese approach. TPM promotes total integration among manpower, machines and the company itself, and the maintenance of the means of production is everybody’s responsibility. The introduction of TPM demands the implementation of the so called sustaining pillars, and planned maintenance is one of them. However, TPM does not specify the strategy to be followed by planned maintenance. RCM is a set of logical procedures aiming at setting up predictive and preventive maintenance in order to effectively and efficiently achieve the security and reliability standards required for each equipment. Considering an environment where TPM has already been implemented, this paper aims at optimizing Planned Maintenance of the TPM by using RCM to guide maintenance strategies in industries. The system proposed is illustrated through a case study in a metal cold roll forming factory.

O atual ambiente competitivo, onde baixo custo, alta qualidade e um grau crescente de customização são exigências para a sobrevivência das empresas, tem influenciado as ações dos profissionais de manutenção com vistas ao aprimoramento das políticas de manutenção. Como resultado, tem-se na área de manutenção industrial, uma grande quantidade de métodos, software, modelos e ferramentas de gestão disponíveis. Dentre eles, dois métodos se destacam: o RCM (Reliability Centered Maintenance ou Manutenção Centrada em Confiabilidade), de origem norte-americana, e a TPM (Total Productive Maintenance ou Manutenção Produtiva Total), de origem japonesa. A TPM promove a integração total entre homem, máquina e empresa, onde a manutenção dos meios de produção passa a constituir uma responsabilidade de todos. A utilização da TPM contempla a implementação de pilares de sustentação, sendo um deles, a manutenção planejada. Entretanto, a TPM não especifica a estratégia a ser adotada pela manutenção planejada. O RCM é uma metodologia lógica de procedimentos que objetiva estabelecer uma manutenção preditiva e preventiva para alcançar, de maneira efetiva e eficiente, os níveis de segurança e confiabilidade requeridas para cada equipamento. Considerando um ambiente com a TPM já implementada, o objetivo deste trabalho é a melhoria do pilar Manutenção Planejada da TPM através da utilização do RCM para nortear as estratégias de manutenção em empresas industriais. A sistemática proposta é ilustrada através de um estudo de caso na indústria de conformação de metais. / Today’s competitive business environment, in which low costs, high quality and an ever increasing degree of customization are essential for companies’ survival has influenced maintenance professionals’ courses of action, aiming at improving maintenance policies. As a result, in the industrial maintenance sector there is a great number of methods, software and management tools available. Among them, two stand out: the RCM (Reliability Centered Maintenance), a North American approach, and the TPM (Total productive Maintenance), a Japanese approach. TPM promotes total integration among manpower, machines and the company itself, and the maintenance of the means of production is everybody’s responsibility. The introduction of TPM demands the implementation of the so called sustaining pillars, and planned maintenance is one of them. However, TPM does not specify the strategy to be followed by planned maintenance. RCM is a set of logical procedures aiming at setting up predictive and preventive maintenance in order to effectively and efficiently achieve the security and reliability standards required for each equipment. Considering an environment where TPM has already been implemented, this paper aims at optimizing Planned Maintenance of the TPM by using RCM to guide maintenance strategies in industries. The system proposed is illustrated through a case study in a metal cold roll forming factory.

Le tritium est un radioélément produit par fission ternaire ou activation neutronique au sein des réacteurs de fission et utilisé comme combustible dans les machines de fusion (comme, en autres, le JET en Angleterre ou le futur ITER à Cadarache). Des études sont actuellement en cours sur la gestion de cette ressource que ce soit en vue de son utilisation ou de son élimination d’effluents gazeux, liquides ou de déchets. Cette thèse se propose d’étudier la revalorisation du tritium en tant que combustible pour les machines de fusion par le biais d’un Réacteur Catalytique à Membrane (RCM). Celui-ci associe les phénomènes de conversion catalytique de l’eau tritiée, par échange isotopique avec le diprotium selon la réaction générique Q_2 O+H_2⇌H_2 O+Q_2 (Q=H,D ou T), et de perméation sélective, d’une membrane à base de palladium. Ce matériau présente une perméabilité exclusive aux isotopes de l’hydrogène H, D et T par formation respective d’hydrures, deutérures ou tritiures de palladium. Au sein du RCM, ces flux transmembranaires permettent, par retrait des produits de réactions, d’atteindre des taux de conversion plus élevés que dans un réacteur à lit fixe à parois imperméables (loi de Le Chatelier). Au CEA, un banc d’essais utilisant le deutérium comme simulant du tritium a été construit dans l’objectif d’étudier de manière séparée, à l’échelle du laboratoire, ces propriétés de conversion et de perméation ainsi que leur couplage. Grâce au développement d’une méthode permettant l’analyse simultanée des isotopologues de l’eau et du dihydrogène par spectrométrie de masse, il a été montré, d’une part, que le catalyseur à base de nickel utilisé présente une activité suffisante pour que l’état d’équilibre thermodynamique des réactions d’échange isotopique soit atteint très rapidement et d’autre part, que le flux de perméation des isotopologues du dihydrogène suit une loi de Richardson. Des analyses de sensibilités sur les paramètres opératoires montrent que les performances globales du RCM (i.e. facteur de dédeutération) croissent avec la température, la différence de pression transmembranaire, le débit de balayage et le temps de séjour dans le tube, mais passent par un maximum avec la variation de la teneur en vapeur d’eau lourde dans le gaz à traiter. Sur la base de ces observations, un modèle phénoménologique quantifiant les transferts de quantités de mouvement et de matière a été développé. Il rend compte du comportement global observé expérimentalement même si un effort reste à fournir sur la modélisation de la perméation des espèces hétéronucléaires. Grâce aux principes physiques sur lesquels il est basé et aux règles de similitudes existant entre les propriétés physico-chimiques des différents isotopologues (loi de Graham), ce modèle est aisément extrapolable au traitement d’espèces tritiées.

Le durcissement des normes d’émission, tout autant que l’impératif d’économie,poussent à étudier de nouveaux modes de combustion pour les moteurs. L’autoallumage decharges homogènes à basse température offre de bonnes perspectives quant au rejet de NOx,suies, et CO2. Cependant son control reste délicat, car il est extrêmement sensible à latempérature et la cinétique de l’hydrocarbure. L’assistance par plasma hors-équilibre pourraitfournir une solution. Les expériences sont menées dans une MCR avec des mélanges pauvresd’isooctane/air et un prototype d’allumeur Renault. La combustion obtenue identifiée commeSICI se déroule en deux phases: la propagation d’une flamme comprime les gaz restantjusqu’à leur autoallumage. Le réchauffement du système expérimental est intégré dans leprotocole d’exploitation, afin de quantifier l’effet SICI relativement à l’autoallumage pur.L’effet du plasma semble avant tout dépendre de l’énergie déposée, bien qu’il convergerapidement, quel que soit l’avance du déclenchement. Le comportement asymptotique à hauteénergie s’explique par la thermalisation des filaments, soulignée par comparaison avec l’effetSICI d’un arc classique. A l’inverse, le seuil minimal d’énergie nécessaire semble lié à lacapacité à générer un noyau de flamme viable, rapprochant le phénomène d’un problèmeclassique d’allumage en conditions difficiles. La propagation de la flamme détermine ledéclenchement de l’autoallumage selon une caractéristique linéaire particulièrementremarquable, car indépendante des conditions thermodynamiques du mélange. L’existenced’une flamme froide est mise en avant par des acquisitions de PLIF formaldéhyde. Lapréréaction semble accélérer la propagation du front de flamme. / Emission standards tightening as well as economical needs urge to study newcombustion modes for engines. Low-temperature homogeneous charge auto-ignition offersgood prospects for NOx, soot, and CO2 emissions. However, its control remains sharp for it isextremely influenced by temperature and fuel chemistry. Assisting non-equilibrium plasmascould provide a solution. Experiments are RCM managed with lean isooctane/air mixtures andprototype Renault ignition devise. Combustion occurs in a two steps mode known as SICI:flame propagation compresses the remaining gas to auto-ignition. The experimental settemperature rise is computed in order to measure the SICI effect compared to pure autoignition.The plasma seems to act mainly through the energy dropped, albeit its effect quicklyreaches a maximum, no matter how early it starts. This asymptomatic high energy behaviorrelies on the streamers overheating, as underlined by the look-like SICI effect from a regulararc discharge. On the contrary, minimal required energy appears to be linked to the capabilityof generating a sustainable flame kernel, making it closer to a standard ignition issue in roughconditions. Flame propagation sets auto-ignition start, according to an astonishingly linearcharacteristic not even influenced by charge’s thermodynamic conditions. Cool flame is putforward through formaldehyde PLIF imaging. Prereaction seems to enhance front propagationspeed.

This thesis is an effort to implement Reliability Centered Maintenance “RCM” for C20trains at Tunnelbanan Teknik Stockholm AB. In depth study is performed along withmaintenance team of TBT at center of excellence, a facility for maintenance workshop. RCM is a philosophy or framework to ensure efficient working of assets according todefined and required operating context. In general, the successful implementation ofRCM can achieve improvements through lesser maintenance, operating techniquechanges, and generating inclusive maintenance plan. RCM is also one of the best toolsavailable to identify and prevent equipment failures. Therefore TBT has decided tointroduce RCM to ensure effective services with great confidence and precision. The selection of critical system of C20 train was obligatory to initiate implementation ofRCM, and the door system was considered a very complicated system with maximumfailures that results in traffic disturbances and stoppages. Through literature study,depots & workshop visits, brainstorming engineers & train drivers etc, the requiredtasks to be performed were lay down. A template that illustrates details such as FMECA,risk analysis, current maintenance strategy and the recommended actions wasprepared and new maintenance regime along with the changes in work instructionswere proposed. The cost effectiveness as well as safety assessment was carried out.Moreover, the efficacy of RCM analysis is directly proportional to quality and accuracyof available failure data, and the proposed time scale for thesis was underestimated andthe reason behind was the convolution of CMMS as well as poor quality of failure data. The study results are officially approved by all stakeholders, i.e. SL, MTR Stockholm,MTR HK and TBT. This work can guide the officials to take imperative decisions foroptimization of maintenance practices, also the study for C20 door system can be theroadmap for comprehensive implementation of RCM at TBT Stockholm AB.

Electrical production in Sweden today is mainly from nuclear and hydro power. However, there is large increase in renewable energy like wind power and the installed new capacity goals are large. Several electrical production sources are important for the sustainability of the energy system. Maintenance is an approach for keeping a system sustainable. The importance of structured maintenance for reliable electrical production systems triggers the development of qualitative and quantitative maintenance management methods. Examples of these methods are Reliability-Centered Maintenance (RCM) which is a structured qualitative approach that focuses on reliability when planning maintenance, and Reliability Centered Asset Management (RCAM) which is a development of RCM into a quantitative approach with the aim to relate preventive maintenance to total maintenance cost and system reliability. This thesis presents models, as applications of RCAM, based on the methods of Life Cycle Cost (LCC) and mathematical optimization, applied to wind and nuclear power plants. Both deterministic and stochastic approaches have been used and the proposed models are based on the Total Cost model, which summarizes costs for maintenance and production loss, and the Aircraft model, which is an opportunistic maintenance optimization model. Opportunistic maintenance is preventive maintenance performed at opportunities. The wind power applications in this study show on different ways to cover costs of condition monitoring systems (CMS) and further on economic benefits of these when uncertainties of times to failure are included in the model. The nuclear power applications show on that the optimization model is dependent on the discount rate and that a high discount rate gives more motivation for opportunistic replacements. When put into a stochastic framework and compared to other maintenance strategies it is shown that an extended opportunistic maintenance optimization model has a good overall performance, and that it, for high values of the constant cost of performing maintenance, is preferable to perform opportunistic maintenance. The proposed models, applied to wind and nuclear power plants, could be extended and adapted to fit other components and systems. / Reliability and cost centered maintenance methods

Bolidens smältverk Rönnskärsverken strävar efter att förbättra sina underhållsrutiner på anläggningen. Det har bestämt sig för att de vill pröva använda sig av en underhållsstrategi som heter Reliability Centered Maintenance (RCM). RCM-metoden har som uppgift att rekommendera en lämplig underhållsmetod för den individuella komponenten som analyseras. Det ska medföra att Rönnskärsverken kan minska sina underhållskostnader om de använder lämpliga underhållsmetoder för sina maskiner. Målen i projektet är att utforma ett förslag på en mall för en RCM-analys och att implementera analysen på en riktig maskin som ska kunna komplettera mallen som ett exempel. Mallen ska kunna användas på alla sorters maskiner på Rönnskärsverken. Dessa mål ska uppfyllas genom litteraturstudie och att studera den utvalda maskinen. Den slutliga mallen blev uppdelad i två delar. I den första delen är det fokus på information om komponenten, bland annat hur viktig den är för systemet. Denna del ger förslag på vilken underhållsmetod som skulle kunna vara lämplig att använda, men även om det finns någon underhållsmetod som inte får användas på denna komponent. Den andra delen av mallen är den del som kommer föreslå vilken underhållsmetod som ska implementeras. Mallen prövades på en maskin som kallas för anodprepen och mer specifikt på anodprepens fräskammare. Den delades upp i 6 mindre komponenter som mallen utfördes på. Resultaten på utförandet av mallen klarade av att rekommendera alla komponenter en underhållsmetod som passar just för den komponenten. Mallen är konstruerad så att personer som har högskoleutbildning och jobbar med underhåll ska kunna utföra den. För att den ska var så enkel som möjligt att använda är den till stor del utformad med ja och nej frågor. / Boliden’s smelter Rönnskärsverken strives to improve its maintenance routines at the facility. They have decided that they want to try using a maintenance strategy called Reliability Centered Maintenance (RCM). The task of the RCM method is to recommend a suitable maintenance method for the individual component being analyzed. This will mean that Rönnskärsverken can reduce its maintenance costs if they use appropriate maintenance methods for their machines. The goals of the project is to design a suggestion of a template for an RCM analysis and to implement the analysis on a real machine, so it can be used as an example for the template. The template should be able to be used on all types of machines at Rönnskärsverken. These goals should be achieved through literature study and studying the involved machines. The final template was divided into two parts. In the first part the focus is on information about the component, including how important it is for the system. This section provides suggestions as to which maintenance method might be suitable to use, but also if there is any maintenance method that should not be used on this component. The second part of the template is the part that will suggest which maintenance method should be implemented. The template was tested on a machine called anodprep and more specifically in the milling chamber of the anodprep. It was divided into 6 smaller components on which the template was made. The results of the test of the template managed to recommend to all components a maintenance method that is suitable for that particular component. The template is made to be used by people who have a university degree and work with maintenance. To make it as simple as possible to use, it is mostly designed with yes or no questions.