L'augmentation de l'accumulation de neige simulée en Antarctique de l'Est pour le siècle à venir est une contribution négative à la hausse du niveau moyen des mers. Les modèles climatiques simulant cette augmentation ne possèdent pas de paramétrisation du transport éolien de neige or ce dernier joue un rôle primordial sur l'accumulation d'après les observations. Les modèles climatiques régionaux possédant une paramétrisation du transport éolien permettent d'estimer l'incertitude des modèles climatiques sur la hausse du niveau moyen des mers en ne représentant pas ce processus. Cependant aucune donnée de transport ne permet une validation précise de ces modèles en Antarctique. Dans ce contexte, cette thèse décrit la constitution d'une base de données de transport éolien de neige en Antarctique ainsi qu'une validation d'un modèle climatique régional incluant le transport éolien de neige. Un instrument acoustique, le FlowCapt, a été choisi pour acquérir les données. Une comparaison avec un appareil de mesure optique du transport, le Snow Particle Counter, a été menée dans les Alpes françaises. Cette comparaison a permis de déterminer les limites des deux générations de FlowCapt existantes pour la détection des événements de transport et la quantification du flux de neige. Une base de données de trois années a été acquise en Terre Adélie, Antarctique, pour permettre une comparaison avec un modèle climatique régional. Elle a permis de calculer la hauteur de rugosité et la vitesse de frottement seuil avec leurs incertitudes. Les épisodes de transport éolien de neige et une borne inférieure de la quantité de neige déplacée en un point ont été estimés. Deux comparaisons ont été menées avec le Modèle Atmosphérique Régional, un modèle climatique régional incluant de nombreuses rétroactions du transport sur l'écoulement. Les deux simulations utilisées pour les comparaisons ont été faites sur un petit domaine à fine échelle sur une période d'un mois. Le modèle simule bien les épisodes de transport sauf lorsque de la fonte s'est produite juste avant un épisode ou lorsque les épisodes ont une hauteur maximale de transport inférieure à cinquante centimètres. Le modèle sous-estime les quantités de neige transportée. / Predicted accumulation by global numerical climate models for the next century increases in East Antarctica and negatively contributes to the mean sea level rise. None of the climate models integrates a blowing snow parametrisation. However few smaller scale regional climate models include a blowing snow parametrisation and thus can assess the climate models uncertainty on the mean sea level rise by not representing this process. Yet none of the blowing snow data available in Antarctica allows for a precise validation of a regional climate model. In this context, this PhD described the establishment of an Antarctica blowing snow database and the validation of a regional climate model including a blowing snow parametrisation. An acoustic blowing snow sensor, the FlowCapt, has been chosen to collect data in Antarctica. A comparison with an optic blowing snow sensor, the Snow Particle Counter, has been conducted in the French Alps. The capacity of the two existing FlowCapt generation has been determined on the blowing snow event and the flux quantification. A three years blowing snow model-oriented database is now available in Adélie Land, Antarctica. The threshold friction velocity and the roughness height have been calculated with their uncertainty. Blowing snow variability has been determined as well as the minimum transport rate at one field point. Two comparisons have been done with the Modèle Atmosphérique Regional (MAR), a regional climate model including a blowing snow parametrisation. Both simulations represent a small domain with a high vertical and horizontal resolution over one month. The model is able to reproduce the blowing snow event except when melting occurs or when the blowing snow height is encompassed within the first fifty centimetres above the ground. The model underestimate the snow quantity transported at the field measurement point.

Made available in DSpace on 2014-07-29T15:32:00Z (GMT). No. of bitstreams: 1 pre_textuais_Kesia.pdf: 463932 bytes, checksum: ba039f279ac8bc3690898dbf68664f23 (MD5) Previous issue date: 2010-04-30 / The present work was realize in two scale, the first of spacious character of consider the inundations happened in Goiânia city, and in the second phase detail the hydrographic basin of Pedreira stream localized in north-east region of Goiânia, in the Goiás state. The objective of this work was spatialization the area of inundation risk in Goiânia and identify the cause and consequence of inundations of Pedreira stream. The choose of area in the study of agenda in resort to accidents register in the basin and the number of people victim these events, that it is significant in relation all areas risk in the capital. It searched analyze the naturals and the occupation of area characters through survey of fact, search of bibliography, Fieldwork, mapping of morphologic and morphometric characters in this basin, mapping land use, interviews with residents, separation of inundations area / accident and elaboration of susceptibility map. For the mapping we adopted the scale 1/20.000. The results took a conclusion that the inundations happen because the condition of physical process that was intensify for basin occupation. The naturals conditions, related of physical process, include the regime of rain of the region, the high slope in the portion more higher of the basin, like relief rugosity, the variation hypsometric, tendency to the concentration of the flow in some concave segments, the form the hydrographic basin and the existence of inundation plain in half basin, the siltation and strangle of the drainage. The basin of Pedreira stream happen than occupation of irregulars dwelling of areas destined to preservation, in the inundation plain in the bank Pedreira stream. The population, include children, is subject at the inundation occurrence. / O presente trabalho foi realizado em duas escalas, a primeira de caráter amplo considera as inundações ocorridas na cidade de Goiânia, numa segunda fase detalha-se a bacia hidrográfica do córrego Pedreira, localizada na região nordeste de Goiânia, no estado de Goiás. O objetivo deste trabalho foi espacializar as áreas de risco de inundação em Goiânia, e identificar as causas e consequências das inundações na bacia do córrego Pedreira. A escolha da área de estudo pautou-se nos recorrentes acidentes registrados na bacia e no número de pessoas vítimas desses eventos, que é significativo em relação a todas as áreas de risco da capital. Buscou-se analisar as características naturais e de ocupação da área por meio do levantamento de dados, pesquisa bibliográfica, trabalho de campo, mapeamento de características morfológicas e morfométricas da bacia, cartografia de uso da terra, entrevistas com os moradores, delimitação das áreas inundáveis/ acidentes e elaboração do mapa de suscetibilidade. Para o mapeamento adotou-se a escala de 1/20.000. Os resultados levaram à conclusão que as inundações ocorrem devido a condicionantes do meio físico, que são intensificados pela ocupação da bacia. Os condicionantes naturais, relacionados ao meio físico, incluem o regime de chuvas da região, a alta declividade nas porções superiores da encosta, a rugosidade do relevo, as variações hipsométricas, a tendência à concentração de fluxo em alguns segmentos côncavos, a forma da bacia hidrográfica e a existência de planície de inundação a partir da meia bacia. A ocupação, por sua vez, provoca a impermeabilização da bacia hidrográfica, o assoreamento e o estrangulamento da drenagem. Na bacia do córrego Pedreira ocorre ainda a ocupação por moradias irregulares de áreas destinadas à preservação, na planície de inundação às margens do córrego Pedreira. A população, incluindo as crianças, fica então sujeita às ocorrências de inundação.

A presente dissertação insere-se no grupo de estudos dedicado a Metodologia de Ensino de Geografia. Investigamos como ocorre a superação dos obstáculos para aprendizagem de um processo físico elementar nas aulas desta disciplina, organizadas através de uma Sequência Didática. Sua principal contribuição é fornecer subsídios teóricos e metodológicos para o planejamento de aulas de Geografia do Ensino Fundamental II que visem trabalhar com temas e conceitos comuns à Geografia Física. Este trabalho apóia-se em autores clássicos e contemporâneos que versam sobre a aprendizagem, a construção do conhecimento e os conceitos geográficos (PIAGET, 1948/2005; BACHELARD, 1938/2008; MEIRIEU, 2000; CAMILLONI, 1997; CASTELLAR; VILHENA, 2010; MONBEIG, 1956; SANTOS, 1997; ROSS, 2006; dentre outros). Procuramos demonstrar e analisar o processo de aprendizagem de um conceito no contexto de uma rotina escolar e segundo os pressupostos pedagógicos e geográficos adotados, o que nos permitiu estabelecer uma relação entre teoria e prática e, a partir desta experiência, teorizar a prática vivenciada. / This present work is part of a study group dedicated to Teaching Methodology of Geography. We investigate how does the overcoming of obstacles to learning an elementary physical process in classes of this discipline, organized through a teaching sequence. Its main contribution is to provide theoretical and methodological planning classes of Geography to Ensino Fundamental II, aiming to work with themes and concepts common to Physical Geography. This work is supported by classic and contemporary authors that deal with learning, construction of knowledge and geographical concepts (PIAGET, 1948/2005; BACHELARD, 1938/2008; MEIRIEU, 2000; CAMILLONI, 1997; CASTELLAR; VILHENA, 2010; MONBEIG, 1956; SANTOS, 1997; ROSS, 2006, among others). We demonstrate and analyze the process of learning a concept in the context of a school routine and according to the geographical and pedagogical assumptions adopted, which allowed us to establish a relationship between theory and practice, and from this experience, theorising our experienced practice.

A presente dissertação insere-se no grupo de estudos dedicado a Metodologia de Ensino de Geografia. Investigamos como ocorre a superação dos obstáculos para aprendizagem de um processo físico elementar nas aulas desta disciplina, organizadas através de uma Sequência Didática. Sua principal contribuição é fornecer subsídios teóricos e metodológicos para o planejamento de aulas de Geografia do Ensino Fundamental II que visem trabalhar com temas e conceitos comuns à Geografia Física. Este trabalho apóia-se em autores clássicos e contemporâneos que versam sobre a aprendizagem, a construção do conhecimento e os conceitos geográficos (PIAGET, 1948/2005; BACHELARD, 1938/2008; MEIRIEU, 2000; CAMILLONI, 1997; CASTELLAR; VILHENA, 2010; MONBEIG, 1956; SANTOS, 1997; ROSS, 2006; dentre outros). Procuramos demonstrar e analisar o processo de aprendizagem de um conceito no contexto de uma rotina escolar e segundo os pressupostos pedagógicos e geográficos adotados, o que nos permitiu estabelecer uma relação entre teoria e prática e, a partir desta experiência, teorizar a prática vivenciada. / This present work is part of a study group dedicated to Teaching Methodology of Geography. We investigate how does the overcoming of obstacles to learning an elementary physical process in classes of this discipline, organized through a teaching sequence. Its main contribution is to provide theoretical and methodological planning classes of Geography to Ensino Fundamental II, aiming to work with themes and concepts common to Physical Geography. This work is supported by classic and contemporary authors that deal with learning, construction of knowledge and geographical concepts (PIAGET, 1948/2005; BACHELARD, 1938/2008; MEIRIEU, 2000; CAMILLONI, 1997; CASTELLAR; VILHENA, 2010; MONBEIG, 1956; SANTOS, 1997; ROSS, 2006, among others). We demonstrate and analyze the process of learning a concept in the context of a school routine and according to the geographical and pedagogical assumptions adopted, which allowed us to establish a relationship between theory and practice, and from this experience, theorising our experienced practice.

Diploma thesis presents topic Classifying chemical reactions that was elaborated on the principle of inquiry based science education. The handbook for teachers, which is a part of the thesis, contains two variants of structured inquiry and two variants of guided inquiry. There are also methodical instructions for teachers, a list of chemicals, the procedure for carrying out the reactions and photo documentation of experiments, including measured graphs of pH and redox potential (PASCO probeware). Inquiry-based science education has the potential to develop key competences, which are becoming an important goal of education at all levels of education. The key competencies are included in the Czech curriculum, the Framework Educational Program for Grammar schools. The next part of the thesis was preparation of the questionnaire focused on developed key competencies. Students that performed laboratory session with the new developed material on topic classification of chemical reaction filled in the questionnaires after their work. The results showed that during the work students had the opportunity to develop five key competences.

With the advancement of sensor technology and data processing capacities, various types of high volume data are available for process monitoring and prognostics in manufacturing systems. In a broaching process, a multi-toothed broaching tool removes material from the workpiece by sequential engagement and disengagement of multiple cutting edges. The quality of the final part, including the geometric integrity and surface finish, is highly dependent upon the broaching tool condition. Though there has been a considerable amount of research on tool condition monitoring and prognostics for various machining processes, the broaching process is unique in the following aspects: 1) a broaching process involves multiple cutting edges, which jointly contribute to the final part quality; 2) the resharpening and any other process adjustments to the tool can only be performed with the whole broaching tool or at least a whole segment of the tool replaced. The overarching goal of this research is to explore how engineering knowledge can be used to improve process monitoring and prognostics for a complex manufacturing process like broaching. This dissertation addresses the needs for developing new monitoring and prognostics approaches based on various types of data. Specifically, the research effort focuses on 1) the use of in-situ force profile data for real-time process monitoring and fault diagnosis, 2) degradation characterization for broaching processes on an individual component level based on image processing; and 3) system-level degradation modeling and remaining useful life prediction for broaching processes based on multiple images. / Ph. D. / Big data have been providing both opportunities and challenges for product quality assurance and improvement in modern manufacturing systems. In aerospace industry, broaching processes are one of the most important manufacturing processes as they are used to produce the turbine discs in the jet engine. Nonconforming turbine disc quality, either in terms of compromised surface finish or geometry accuracy, will lead to malfunction or even catastrophic failures in the aircraft engines. One of the major sources that lead to nonconforming product quality is excessive tool wear accumulation and other abrupt malfunctions of the broaching tools. In broaching processes, multiple cutting edges are sequentially pushed or pulled through the workpiece, and each cutting edge is responsible to shape the workpiece into a specific intermediate shaped contour. Therefore, a broaching process can be regarded as a multistage manufacturing process with variation propagating through the multiple cutting edges. The overarching goal of this dissertation is to explore how process knowledge can be used to improve process monitoring and prognostics for a complex manufacturing process like broaching. This dissertation focuses on the quality assurance and improvement for broaching processes which includes: 1) timely abrupt process fault detection; 2) tool performance degradation quantification; and 3) remaining tool life prediction, which contributes to both methodological development and practical applications in advanced sensing analytics in manufacturing systems.

The Electrical Power Systems (EPS) are indispensable for a Nuclear Power Plant (NPP). The EPS are essential for plant start-up, normal operation, and emergency conditions. Electrical power systems are necessary not only for power generation, transmission, and distribution but also to supply reliable power for plant operation and control system during safe operation, Design Basis Conditions (DBC) and Design Extension Conditions (DEC). According to IAEA Specific Safety Guide SSG-34, EPS are essentially the support systems of many plant equipment. Electrical system, which supply power to plant systems important to nuclear safety, are essential to the safety of an NPP. In recent years, due to the digitization of Instrumentation and Control (I&C) systems, along with their enhanced accuracy, ease of implementing complex functions and flexibility, have been also exposed to sophisticated cyber threats. Despite physical separation and redundant electrical power supply sources, malicious cyber-attacks performed by insiders or outsiders might disrupt the power flow and result in an interruption in the normal operation of an NPP. Therefore, for the uninterrupted operation of a plant, it is crucial to contemplate cybersecurity in the EPS design and implementation. Considering multiple cyber threats, the main objectives of this research work are finding out security vulnerabilities in electrical power systems, simulating potential cyber-attacks and analyzing the impacts of these attacks on the electrical components to protect the electrical systems against these cyber-attacks. An EPS testbed at a small scale was set up, which included commercial I&C and electrical equipment significant for the cybersecurity analysis. The testbed equipment comprises of electrical protection relay (IEC 60255), controller, operating panel, engineering workstation computer, simulation model, etc. to monitor and control the power supply of one or more electrical equipment responsible for a regular operation in an NPP. Simulated cybersecurity attacks were performed using this testbed and the outcomes were examined in multiple iterations, after adding or changing security controls (cybersecurity countermeasures). Analyzing the cybersecurity and performing cyber-attacks on these systems are very advantageous for a real power plant to prepare and protect the plant equipment before any malicious attack happens. This research work conclusively presents cybersecurity analysis, including basic and sophisticated cyber-attack scenarios to understand and improve the cybersecurity posture of EPS in an NPP. The approach was completed by considering the process engineering systems (e.g. reactor core cooling systems) as attack targets and investigating the EPS specific security Defense-in-Depth (DiD) design together with the Nuclear Safety DiD concepts.:CHAPTER 1 INTRODUCTION 1.1 Motivation 1.2 Technical Background 1.3 Objectives of the Ph.D. Project 1.4 State of the Art in Science and Technology CHAPTER 2 FUNDAMENTALS OF CYBERSECURITY AND ELECTRICAL CONTROL AND PROTECTION CONCEPTS 2.1 Electrical Power System 2.2 Electrical Protection System 2.3 Cyber-Physical System 2.4 Industrial Control System 2.5 Safety I&C and Operational I&C Systems 2.6 Safety Objective Oriented Top-Down Approach 2.7 Cybersecurity Concept 2.8 Threat Identification and Characterization in NPP 2.8.1 Design Basis Threat 2.8.2 Attacker Profile 2.8.1 Reported Real-Life NPP Cyber-Attack Examples 2.9 Security Levels 2.10 Summary CHAPTER 3 CYBER-PHYSICAL PROCESS MODELING 3.1 Introduction 3.2 Single Line Diagrams of Different Operational Modes 3.3 Design 3.4 Block Diagram of Simulink Model 3.5 Implementation of Simulink Blocks 3.5.1 Power Generation 3.5.2 Grid Feed 3.5.3 House Load (Feed Water Pump) 3.6 OPC UA Communication 3.7 Summary CHAPTER 4 CYBER THREAT SCENARIOS FOR EPS 4.1 Introduction 4.2 Cyber-Physical System for EPS 4.3 Cyber Threats and Threat Sources 4.3.1 Cyber Threats 4.3.2 Threat Sources 4.4 Cybersecurity Vulnerabilities 4.4.1 Vulnerabilities in EPS 4.4.2 Vulnerabilities in ICS 4.5 Attacker Modeling 4.6 Basic Cyber Threat Scenarios for EPS 4.6.1 Scenario-1: Physical Access to Electrical Cabinets 4.6.2 Scenario-2: Modification of Digital Protection Devices 4.7 Potential Advanced Cyber Threat Scenarios for EPS 4.7.1 Scenario-1: Alteration of a Set-point of the Protection Relay 4.7.2 Scenario-2: Injection of Malicious Packets 4.7.3 Scenario-3: False Trip Command 4.7.4 Scenario-4: Availability Attack on Protection Relay or SCADA System 4.7.5 Scenario-5: Permanent Damage to Physical Component 4.7.6 Scenario-6: Protocol-wise Attack on Operator Panel 4.8 Threat Scenario for Simulink model 4.9 Summary CHAPTER 5 EPS TESTBED DESCRIPTION 5.1 Introduction 5.2 Basic Industrial Automation Architecture 5.3 Need for Testbeds 5.4 Proposed EPS Testbed 5.4.1 Testbed Architecture 5.4.2 Testbed Implementation 5.5 EPS Physical Testbed Applications 5.5.1 Modeling and Simulation of Power System Faults 5.5.2 Modeling of Cyber-Attacks 5.6 Summary CHAPTER 6 EXPERIMENTAL AND IMPACT ANALYSIS OF CYBER THREAT SCENARIOS 6.1 Outline 6.2 Normal Operation and Control 6.3 Possibilities to Cause Failure in the Primary or Secondary Cooling Systems 6.4 Implementation of Cybersecurity Threat Scenarios 6.4.1 Alteration of a Relay Set-Point during Plant Start-Up Phase 6.4.2 Alteration of a Controller Set-Point during Normal Operation Phase 6.4.3 Availability Attack on Control and Protection System 6.4.4 Severe Damage to a Physical Component due to Overcurrent 6.5 Experimentally Assessed Cyber-attacks 6.6 Summary CHAPTER 7 SUMMARY AND OUTLOOK REFERENCES SCIENTIFIC PUBLICATIONS GLOSSARY