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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Comparative review of the benefits and flexibility of small modular reactor designs

Featherstone, Keith 25 January 2021 (has links)
Over the past few years, there has been a sustained interest in the development of small modular reactors (SMRs) evident by the number of global initiatives focused on SMR development. This desktop study was performed to review the viability of SMRs based on their benefits and flexibility, focusing predominantly on the light water NuScale and the gas cooled AHTR designs. In assessing the level of safety, the typical general design and safety criteria were reviewed to establish a basis to compare the NuScale and AHTR designs. The need for flexibility to support grid operators and the ability of a nuclear plant to load follow were reviewed to confirm their flexibility. The principal of cogeneration and the feasibility for cogeneration and energy storage with SMRs was explored to determine the potential industrial application. Finally, the technical readiness and uncertainties, the potential market and economic competitiveness of SMRs were reviewed. The review established that SMRs with safety performance levels exceeding those of current reactor designs are definitely viable. The ability to prevent fuel failure through passive cooling simplifies the design by eliminating the need for complex safety systems and reduces the constraints associated with siting, opening up energy markets where previously nuclear reactors would not have been viable. Their flexibility and the ability to add additional units over time enable them to integrate into any size electrical network and a variety of energy markets. As a clean energy source, SMRs are well suited to support strategies to reduce greenhouse gas emissions and replace fossil-based energy sources. SMRs operating at high temperatures have the added option of considering thermal storage as a means to provide additional flexibility. The biggest uncertainty in the deployment of SMRs is associated with the regulatory and licencing processes. However, there is a large potential market for SMRs and the lower capital cost per unit, the shorter period until a revenue stream is established and the ability to stagger the financial impact of additional units are expected to make SMRs easier to finance than large nuclear units. This preliminary review concluded that SMRs are definitely viable, but until a SMR design has been successfully licenced, constructed and operated, the uncertainty associated with the licencing of a new technology and the potential for long delays during construction are likely to prevent any large-scale deployment in the near future.
2

Proposta de uma metodologia para divulgação da Tecnologia Nuclear / Proposal for a methodology for dissemination of the Nuclear Technology

Lobo, Belinda Maria 09 November 2017 (has links)
A maioria da população forma a sua opinião pelo senso comum, influenciada pelas informações divulgadas pela mídia, principalmente quando envolve acidentes. Normalmente, as notícias são veiculadas acentuando somente os seus aspectos negativos de forma dramática, o que em muito amplia o alcance espaço/temporal do impacto contrário de qualquer evento proveniente de ação antrópica, ou seja, não natural. Esse é o caso da Tecnologia Nuclear que, enquanto ciência e tecnologia, sofre as consequências decorrentes das duas bombas atômicas lançadas em 1945 sobre as cidades de Hiroshima e Nagasaki e dos acidentes com material radioativo. Até hoje, o público tem sérias restrições à sua utilização porque desconhece os benefícios que ela propicia para a sociedade, por terem a sua opinião formada pelo senso comum. Para o desenvolvimento da metodologia optou-se por trabalhar com grupos de professores como população amostral, haja vista que seus alunos são vetores para a disseminação do conhecimento adquirido em sala de aula, por serem profissionais críticos em relação às metodologias e aproximar a universidade aos profissionais de ensino. Este trabalho apresenta um roteiro de apresentação, como proposta para a divulgação da Tecnologia Nuclear para qualquer público, composta por cinco etapas: Questionário Inicial; Trecho de um Vídeo de uma reportagem do acidente com um aparelho de radioterapia; Palestra Elucidativa; Atividade Final e informações técnicas para Interação no Espaço da Tecnologia Nuclear. / Most of the people form their opinion through common sense, influenced by the information disclosed by the media, especially when it involves accidents. Usually, the news is conveyed accentuating only its negative aspects in a dramatic way, which greatly enlarges the space / time reach of the contrary impact of any event coming from anthropic action, that is, unnatural. This is the case of Nuclear Technology, which as science and technology, suffers from the consequences of the two atomic bombs launched in 1945 on the cities of Hiroshima and Nagasaki and from accidents with radioactive material. To this day, people have serious restrictions on its uses, because they are not aware of its benefits to the society, due to their common sense forget opinion. For the development of the methodology it was decided to work with groups of teachers as sample population, since their students are vectors for the dissemination of the knowledge acquired in the classroom, also because they are critical professionals in relation to methodologies and to bringing the university closer to education professionals. This work introduces a presentation screenplay as a proposal for the dissemination of Nuclear Technology to any public, composed of five stages: Initial Questionnaire; Video of news reporting the accident with a radiotherapy equipment; Elucidative Lecture; Final Activity and technic information to the Interaction in the Nuclear Technology Space.
3

Proposta de uma metodologia para divulgação da Tecnologia Nuclear / Proposal for a methodology for dissemination of the Nuclear Technology

Belinda Maria Lobo 09 November 2017 (has links)
A maioria da população forma a sua opinião pelo senso comum, influenciada pelas informações divulgadas pela mídia, principalmente quando envolve acidentes. Normalmente, as notícias são veiculadas acentuando somente os seus aspectos negativos de forma dramática, o que em muito amplia o alcance espaço/temporal do impacto contrário de qualquer evento proveniente de ação antrópica, ou seja, não natural. Esse é o caso da Tecnologia Nuclear que, enquanto ciência e tecnologia, sofre as consequências decorrentes das duas bombas atômicas lançadas em 1945 sobre as cidades de Hiroshima e Nagasaki e dos acidentes com material radioativo. Até hoje, o público tem sérias restrições à sua utilização porque desconhece os benefícios que ela propicia para a sociedade, por terem a sua opinião formada pelo senso comum. Para o desenvolvimento da metodologia optou-se por trabalhar com grupos de professores como população amostral, haja vista que seus alunos são vetores para a disseminação do conhecimento adquirido em sala de aula, por serem profissionais críticos em relação às metodologias e aproximar a universidade aos profissionais de ensino. Este trabalho apresenta um roteiro de apresentação, como proposta para a divulgação da Tecnologia Nuclear para qualquer público, composta por cinco etapas: Questionário Inicial; Trecho de um Vídeo de uma reportagem do acidente com um aparelho de radioterapia; Palestra Elucidativa; Atividade Final e informações técnicas para Interação no Espaço da Tecnologia Nuclear. / Most of the people form their opinion through common sense, influenced by the information disclosed by the media, especially when it involves accidents. Usually, the news is conveyed accentuating only its negative aspects in a dramatic way, which greatly enlarges the space / time reach of the contrary impact of any event coming from anthropic action, that is, unnatural. This is the case of Nuclear Technology, which as science and technology, suffers from the consequences of the two atomic bombs launched in 1945 on the cities of Hiroshima and Nagasaki and from accidents with radioactive material. To this day, people have serious restrictions on its uses, because they are not aware of its benefits to the society, due to their common sense forget opinion. For the development of the methodology it was decided to work with groups of teachers as sample population, since their students are vectors for the dissemination of the knowledge acquired in the classroom, also because they are critical professionals in relation to methodologies and to bringing the university closer to education professionals. This work introduces a presentation screenplay as a proposal for the dissemination of Nuclear Technology to any public, composed of five stages: Initial Questionnaire; Video of news reporting the accident with a radiotherapy equipment; Elucidative Lecture; Final Activity and technic information to the Interaction in the Nuclear Technology Space.
4

Técnicas eficientes para análise e modelação de efeitos de acoplamento via substrato em circuitos integrados mistos

Costa, João Paulo dos Santos da January 1998 (has links)
No description available.
5

Codificação de sistemas de comunicações móveis com débito variável

Lopes, Alberto Amaral January 1998 (has links)
No description available.
6

Estudo de demanda do radiofármaco 18F-FDG nas regiões metropolitanas de São Paulo e áreas adjacentes / Study of the demand for radiopharmaceutical 18F-FDG in the metropolitan regions of São Paulo and adjacent areas

Sato, Renato Cesar 31 March 2006 (has links)
No Brasil e no mundo a medicina nuclear vem ganhando destaque com as técnicas diagnósticas que permitem o estudo metabólico de doenças, alterando significativamente o gerenciamento dos pacientes. Essa tecnologia inovadora vem trazendo expectativas tanto para os setores especializados como para a sociedade. Nesse trabalho foi estudada a utilização do radiofármaco 18F-FDG na região metropolitana de São Paulo e nas áreas adjacentes, bem como a estrutura do mercado atual e das dificuldades a serem superadas com o aumento da demanda do 18F-FDG. A pesquisa contou com uma análise do mercado de radiofármacos internacional e das principais alterações que vem ocorrendo nessa área no Brasil nos últimos anos. Foram realizadas entrevistas com profissionais atuantes na área de medicina nuclear e coleta de dados através de questionário enviado para os centros consumidores do radiofármaco na região coberta pela pesquisa. As entrevistas expressaram as opiniões dos entrevistados sobre as transformações nesse setor e as tendências futuras e os dados coletados no questionário serviram de complementação a utilização do radiofármaco nos equipamentos do tipo Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) e Positron Emission Tomography / Computer Tomography (PET/CT). O maior uso do 18F-FDG tem sido para o diagnóstico oncológico nos equipamentos do tipo PET e PET/CT. Essa utilização deverá crescer nos próximos anos, podendo se expandir para outras especialidades como neurologia e cardiologia. Apesar de restrita atualmente as cidades de São Paulo e Rio de Janeiro deverá haver uma expansão dessa modalidade diagnóstica nos outros Estados do país que começam a estruturar produção do radioisótopo. A recente alteração na constituição que permite a produção e comercialização de radioisótopos de meia-vida curta também deverá aumentar o interesse da iniciativa privada nesse mercado, que internacionalmente possui projeções otimistas de crescimento. Existe também uma expectativa que a aprovação dos planos de saúde para a cobertura dos exames utilizando 18F-FDG no PET impulsione esse mercado ainda mais, repetindo a experiência internacional. Os recentes investimentos realizados pelo IPEN para aumentar a produção do 18F-FDG deverá garantir a oferta com confiabilidade, para a região Sudeste e Sul do país. / Nuclear Medicine in Brazil and worldwide has developed distinction with diagnosis techniques that allow metabolic research of the disease, changing in a significant fashion the patients outcome. This innovative technology leads expectations from specific fields up to society itself. This research studied the use of 18F-FDG radiopharmaceutical in the metropolitan region of São Paulo and adjacent areas, as well as the recent trade structure and the difficulties that should be overcome with the increase of the 18F-FDG demand. This research counted on the analysis of the international radiopharmaceutical trade and the main changes that have been happening in this area in Brazil during the past few years. Interviews were performed with professionals within the area of nuclear medicine and data has been collected through questionnaire sent to the consuming centers of the radiopharmaceutical in the region covered in this research. The interviews expressed the opinions of the interviewees concerning transformations in this field and future tendencies and the information obtained from the survey was the basis of complementation of the use of radiopharmaceutical on equipments such as Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) and Positron Emission Tomography / Computer Tomography (PET/CT). The major use of 18F-FDG has been used for oncology diagnosis with equipments such as PET and PEC/CT. This use shall grow in the next years, maybe expanding to other specialties such as neurology and cardiology. Although nowadays restricted to the cities of São Paulo and Rio de Janeiro, there is a possibility of expansion to other diagnosis modalities in other states of the country that are starting to structure the production of the radioisotope. The recent change in the constitution permitting the production and commerce of short half-life radioisotopes also contributes to the increase the interest of private funding of this sector in which internationally holds optimistic projections of increase. There is also the expectancy that approving health care plans coverage of these exams using 18F-FDG with PET to boast more this sector, repeating international experience. Recent investments made by IPEN to increase the production of 18F-FDG shall guarantee the offer of confidentiality for the Southeast and Southern regions of the country.
7

Estudo de demanda do radiofármaco 18F-FDG nas regiões metropolitanas de São Paulo e áreas adjacentes / Study of the demand for radiopharmaceutical 18F-FDG in the metropolitan regions of São Paulo and adjacent areas

Renato Cesar Sato 31 March 2006 (has links)
No Brasil e no mundo a medicina nuclear vem ganhando destaque com as técnicas diagnósticas que permitem o estudo metabólico de doenças, alterando significativamente o gerenciamento dos pacientes. Essa tecnologia inovadora vem trazendo expectativas tanto para os setores especializados como para a sociedade. Nesse trabalho foi estudada a utilização do radiofármaco 18F-FDG na região metropolitana de São Paulo e nas áreas adjacentes, bem como a estrutura do mercado atual e das dificuldades a serem superadas com o aumento da demanda do 18F-FDG. A pesquisa contou com uma análise do mercado de radiofármacos internacional e das principais alterações que vem ocorrendo nessa área no Brasil nos últimos anos. Foram realizadas entrevistas com profissionais atuantes na área de medicina nuclear e coleta de dados através de questionário enviado para os centros consumidores do radiofármaco na região coberta pela pesquisa. As entrevistas expressaram as opiniões dos entrevistados sobre as transformações nesse setor e as tendências futuras e os dados coletados no questionário serviram de complementação a utilização do radiofármaco nos equipamentos do tipo Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) e Positron Emission Tomography / Computer Tomography (PET/CT). O maior uso do 18F-FDG tem sido para o diagnóstico oncológico nos equipamentos do tipo PET e PET/CT. Essa utilização deverá crescer nos próximos anos, podendo se expandir para outras especialidades como neurologia e cardiologia. Apesar de restrita atualmente as cidades de São Paulo e Rio de Janeiro deverá haver uma expansão dessa modalidade diagnóstica nos outros Estados do país que começam a estruturar produção do radioisótopo. A recente alteração na constituição que permite a produção e comercialização de radioisótopos de meia-vida curta também deverá aumentar o interesse da iniciativa privada nesse mercado, que internacionalmente possui projeções otimistas de crescimento. Existe também uma expectativa que a aprovação dos planos de saúde para a cobertura dos exames utilizando 18F-FDG no PET impulsione esse mercado ainda mais, repetindo a experiência internacional. Os recentes investimentos realizados pelo IPEN para aumentar a produção do 18F-FDG deverá garantir a oferta com confiabilidade, para a região Sudeste e Sul do país. / Nuclear Medicine in Brazil and worldwide has developed distinction with diagnosis techniques that allow metabolic research of the disease, changing in a significant fashion the patients outcome. This innovative technology leads expectations from specific fields up to society itself. This research studied the use of 18F-FDG radiopharmaceutical in the metropolitan region of São Paulo and adjacent areas, as well as the recent trade structure and the difficulties that should be overcome with the increase of the 18F-FDG demand. This research counted on the analysis of the international radiopharmaceutical trade and the main changes that have been happening in this area in Brazil during the past few years. Interviews were performed with professionals within the area of nuclear medicine and data has been collected through questionnaire sent to the consuming centers of the radiopharmaceutical in the region covered in this research. The interviews expressed the opinions of the interviewees concerning transformations in this field and future tendencies and the information obtained from the survey was the basis of complementation of the use of radiopharmaceutical on equipments such as Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) and Positron Emission Tomography / Computer Tomography (PET/CT). The major use of 18F-FDG has been used for oncology diagnosis with equipments such as PET and PEC/CT. This use shall grow in the next years, maybe expanding to other specialties such as neurology and cardiology. Although nowadays restricted to the cities of São Paulo and Rio de Janeiro, there is a possibility of expansion to other diagnosis modalities in other states of the country that are starting to structure the production of the radioisotope. The recent change in the constitution permitting the production and commerce of short half-life radioisotopes also contributes to the increase the interest of private funding of this sector in which internationally holds optimistic projections of increase. There is also the expectancy that approving health care plans coverage of these exams using 18F-FDG with PET to boast more this sector, repeating international experience. Recent investments made by IPEN to increase the production of 18F-FDG shall guarantee the offer of confidentiality for the Southeast and Southern regions of the country.
8

Analys av revisionsarbetet på Forsmarks kärnkraftverk / Analysis of planned maintenance work at theForsmark nuclear power plant

Mattsson, Erik January 2013 (has links)
This thesis is the final part of bachelors program of Nuclear Engineering at UppsalaUniversity (program code KKI1). The work has been carried out in cooperation withForsmark Kraftgrupp AB. The topic studied deals with possible improvements ofefficiency at the planning department at block 2 in Forsmark i.e. FMP2. FMP2 plans and coordinates over 3,000 operations which is carried out during theannual overhaul of block 2 in Forsmark. Inspections, fuel replacement and repairs areincluded in the annual overhaul. The overhaul shall contribute to secure and reliableoperation of the block. The overhaul shall mitigate the risk of unplanned downtime. Also accidents, financiallosses and damage to reputation among public and the Regulators (i.e. SSM and IAEA)shall be avoided. The time for overhaul depends on actions that must be executedand the complexity of the work. Normally, the overhaul time last for a number ofweeks and in rarely cases it can last for months. One topic in the thesis has been to find and describe a way for the planningdepartment (FMP2) to improve status control in ongoing overhaul activities and toincrease the planning department efficiency i.e. to save time for the planningdepartment. With better status control and faster work in the planning departmentthe total overhaul time can be expected to be shortened. Additionally the thesisdiscusses the importance of reliable and secure nuclear power management with therespect to society. The thesis is partly based on examine of current work practices, a literature studyand interviews with employees. The literature study addresses interaction betweenhumans and technology and how to accomplish good decisions. The interviews havebeen made to gather experiences from earlier used working methods. This report shows that FMP2 's current working model is good, although not perfect.It is probable that efficiency improvements at the individual level can be reached thatincreases employed personnel working capacity. Enhanced efficiency can also bereached by using better computer programs that manages the functions that currentlyrequire several separate IT-systems. A number of recommendations are given in thereport for how operations can be improved. Among other things, a proposal toexplore how extraordinary working efforts shall be rewarded. The nuclear power energy importance for the Swedish electricity power balance hasbeen discussed. The conclusion is that customers, electricity generators and thepublic benefits from reliable and secure nuclear power management.
9

Studie zur Partitionierung und Transmutation (P&T) hochradioaktiver Abfälle Stand der Grundlagen- und technologischen Forschung

Merk, Bruno, Glivici-Cotruta, Varvara 29 October 2014 (has links) (PDF)
Das, dem Teilprojekt zu Grunde liegende, Gesamtprojekt gliederte sich in zwei Module: In Modul A (Förderung durch das BMWi, Federführung durch KIT) und Modul B (Förderung durch das BMBF, Federführung durch acatech). Projektpartner im Modul A waren DBE TECHNOLOGY GmbH, die Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), das Helmholtz-Zentrum Dresden-Rossendorf (HZDR), das Karlsruher Institut für Technologie (KIT) und die Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen zusammen mit dem Forschungszentrum Jülich (FZJ). Modul B wurde vom Zentrum für Interdisziplinäre Risiko- und Innovationsforschung der Universität Stuttgart (ZIRIUS) bearbeitet. Die Gesamtkoordination der beidem Module erfolgte durch die Deutsche Akademie der Technikwissenschaften (acatech). Auf Grundlage einer Analyse der wissenschaftlich-technischen Aspekte durch Modul A wurden die gesellschaftlichen Implikationen bewertet und daraus in Modul B Kommunikations- und Handlungsempfehlungen für die zukünftige Positionierung von P&T formuliert. Im, vom HZDR koordinierten, Teilprojekt „Stand der Grundlagen- und technologischen Forschung“ wird eine Übersicht über den genannten Bereich gegeben. Eingeführt wird das Thema mit einer Kurzbeschreibung möglicher Reaktorsysteme für die Transmutation. Danach wird der Entwicklungsstand der Spezialbereiche Trennchemie, Sicherheitstechnologie, Beschleunigertechnologie Flüssigmetalltechnologie, Entwicklung von Spallationstargets, Transmutationsbrennstoffen und Werkstoffkonzepten sowie Konditionierung von Abfällen, beschrieben. Dies wird ergänzt durch Spezifika von Transmutationsanlagen beginnend bei physikalischen Grundlagen und Kerndesigns, über Reaktorphysik von Transmutationsanlagen, Simulationstools und die Entwicklung von Safety Approaches. Im Anschluss wird der Stand existierender Bestrahlungseinrichtungen mit schnellem Spektrum beschrieben. Nachfolgend werden basierend auf dem derzeitigen Stand von F&E die offenen Fragen und Forschungslücken in den einzelnen Teilbereichen – Wiederaufbereitung und Konditionierung, Beschleuniger und Spallationstarget, Reaktor – zusammengestellt und sowohl eine Strategie, als auch ein Fahrplan zur Schließung der Technology Gaps entwickelt. Zusätzlich werden die Hauptbeiträge, des HZDR zur Gesamtstudie beschrieben. Dies sind insbesondere die Beschreibungen der Möglichkeiten und Grenzen von P&T, die Herausforderungen an Bestrahlungseinrichtungen zur Transmutation und deren Effektivität, sowie Sicherheitsmerkmale beschleuniger-getriebener unterkritischer Systeme inclusive grundlegender Störfallbetrachtungen und Sicherheitscharakteristik. / The main project, where this sub project contributed to, has been structured into two modules: module A (funded by the federal ministry of economics, managed by KIT) and module B (funded by the federal ministry of education and research, managed by acatech). Partners in module A were DBE TECHNOLOGY GmbH, the Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Karlsruher Institute of Technology (KIT) and the Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, in co-operation with the Forschungszentrum Jülich (FZJ). Modul B has been executed by the Zentrum für Interdisziplinäre Risiko- und Innovationsforschung der Universität Stuttgart (ZIRIUS). The overall coordination has been carried out by the Deutsche Akademie der Technikwissenschaften (acatech). The social implications have been evaluated in module B based on the analysis of the scientific and technological aspects in module A. Recommendations for communication and actions to be taken for the future positioning of P&T have been developed. In the project part, coordinated by HZDR – status of R&D – an overview on the whole topic P&T is given. The topic is opened by a short description of reactor systems possible for transmutation. In the following the R&D status of separation technologies, safety technology, accelerator technology, liquid metal technology, spallation target development, transmutation fuel and structural material development, as well as waste conditioning is described. The topic is completed by the specifics of transmutation systems, the basic physics and core designs, the reactor physics, the simulation tools and the development of Safety Approaches. Additionally, the status of existing irradiation facilities with fast neutron spectrum is described. Based on the current R&D status, the research and technology gaps in the topics: separation and conditioning, accelerator and spallation target, and reactor are characterized and a strategy as well as a roadmap for closing these gaps has been developed. In addition the major contributions of HZDR to the main project are described. The major parts are the description of the potential and the limits of P&T, the requirements and challenges for transmutation systems and the related efficiency, as well as the safety features of accelerator driven subcritical systems including the transient behavior and the safety characteristics.
10

Stochastic modeling of water flow through a variably-saturated, heterogeneous field at Idaho National Laboratory uncertainty analysis /

Yang, Limin, January 2005 (has links) (PDF)
Thesis (M.S. in engineering)--Washington State University, August 2005. / Includes bibliographical references.

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