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1
Paiva, Fabio de. "Estudo das respostas de TLD tipo LiF para caracterização de campos mistos." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-18102016-105401/.
Full textAbstract:
A Terapia por Captura de Nêutrons, NCT (Neutron Capture Therapy) é uma técnica radioterápica em que a energia útil do tratamento vem da energia liberada em uma reação nuclear e não do feixe primário, como comumente utilizado em outros procedimentos radioterápicos. O Boro, por constituir-se em um elemento de baixa toxicidade e por apresentar um isótopo (10B) com alta seção de choque para a reação 10B(n,α)7Li tem sido o elemento mais utilizado nas pesquisas que visam o aprimoramento e a promoção desta técnica, derivando daí o termo BNCT (Boron Neutron Capture Therapy). Para fins de pesquisa em BNCT foi construída ao longo de um dos extratores de feixes (BH - Beam Hole) do reator IEA-R1 uma instalação, onde filtros e moderadores são posicionados entre o núcleo do reator e a posição de irradiação com o objetivo de modular o feixe de irradiação, otimizando a componente útil do feixe, os nêutrons térmicos, e reduzindo os contaminantes, raios gama e nêutrons em outras faixas energéticas. Tem-se realizado estudos visando a implementação de melhorias na caracterização e otimização do feixe obtido nesse arranjo instalado no BH-3. Atualmente a monitoração dos nêutrons é feita através de folhas de ativação, e a componente gama pelo TLD-400. Uma nova metodologia de monitoração tem sido estudada pelo grupo. A referida técnica consiste em usar TLDs de tipos diferentes, ou seja, que possuam sensibilidades distintas aos nêutrons térmicos, em virtude de diferenças na concentração dos isótopos de Lítio. No estudo dessa nova metodologia têm sido usados os TLD-600 e TLD-700. Este trabalho propõe uma metodologia usando o par TLD-100 e TLD-700. Inicialmente foi verificada a reprodutibilidade das respostas dos TLDs 700, 400 e 100 frente a campos gama puro e campos mistos, gama e nêutron. Campos estes obtidos em arranjos usando fontes de 60Co e 241AmBe. A partir de simulações usando o VI MCNP5 foi projetado e construído um Irradiador de campos mistos, que permitiu expor os dosímetros em campos mistos com diferentes espectros energéticos. As condições criadas no irradiador permitiram verificar, como a resposta do TLD é modificada pelas mudanças no espectro energético de um campo misto gama e nêutrons de baixo fluxo. O irradiador de campo misto permitiu condições para estabelecer uma relação entre o formato da curva termoluminescente e a composição do campo misto. A relação estabelecida relaciona o fluxo relativo e a razão entre a resposta das duas regiões de interesse dos TLDs 700 e 100. A partir de campos mistos com condições controladas, esse trabalho permitiu verificar a viabilidade do uso do par de TLD-100 e TLD-700 para monitoração de nêutrons térmicos na instalação de BNCT.Neutron Capture Therapy (NCT), is a radiotherapy technique in which the useful treatment energy comes from the energy released in a nuclear reaction and not from the primary beam, as commonly used in other radiotherapc procedures. Boron, an element of low toxicity presents an isotope (10B) with high cross-section for the (n, α) reaction and therefore has been the element mostly used in research aimed at the improvement and promotion of this technique, deriving hence the term BNCT (Boron Neutron Capture Therapy). For BNCT research purposes, a facility was built along one of radiation extractors of the IEA-R1 reactor. In this facility filters and moderators are positioned between the reactor core and the irradiation position aiming to modulate the irradiation beam by optimizing the useful component of the beam, thermal neutrons, and reducing its contaminants, gamma rays and neutrons in higher energy bands. We have conducted studies aimed at implementing improvements in the characterization of and optimization of the beam. Currently, neutron flux monitorion is done through activation foils, and the gamma component by TLD-400. A new methodology has been studied by the group. The technique consists in using different types of TLD, having different sensitivities to thermal neutrons due to differences in the concentration of lithium isotopes. In the study of this new methodology TLD 600 and TLD-700 have been used. This work presents a series of studies in order to apply a methodology using the TLD-100 and TLD-700 pair. TLDs 700, 400 and 100 responses pure gamma and mixed irradiation fields, obtained in arrangements using a 60Co and AmBe sources, were evaluaterd. MCNP simulations were run in order to both discriminating the radiation components and designing one mixed fields irradiator, which allowed exposing dosimeters in mixed fields with different energy spectra. The conditions created in the irradiator allowed to verify, as the TLD response is modified by changes in the energy spectrum of a mixed gamma neutron fields. VIII This irradiator provided irradiation conditions so to establish a relationship between the shape of the LiF glow curves and the composition of the mixed field. This work has shown the feasibility of using the TLD-100 and TLD-700 pair for gamma and thermal neutrons monitoration in the BNCT facility.
2
Junior, Valdeci Carneiro. "Caracterização do campo de nêutrons na instalação para estudo em BNCT no Reator IEA-R1." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-01092009-172117/.
Full textAbstract:
Este trabalho tem como objetivo realizar a caracterização do campo de nêutrons e radiação gama na posição de irradiação de amostras em uma instalação para pesquisas em Terapia por Captura de Nêutrons em Boro (BNCT) no IPEN, junto ao reator IEA-R1. A técnica de BNCT vem sendo estudada como uma opção seletiva e segura de tratamento para tumores cancerígenos resistentes ou considerados não tratáveis pelas técnicas convencionais, por exemplo, o Glioblastoma Multiforme - tumor cancerígeno no cérebro. Foram realizadas medições de fluxos de nêutrons térmicos, epitérmicos e rápidos bem como das doses devido a nêutrons, e radiação gama na posição de amostra, utilizando-se detectores de ativação tipo folha e dosímetros termoluminescente. Para determinação da intensidade e do espectro de energia de nêutrons, foi utilizado um conjunto de folhas de ativação de energias limiares distintas, irradiadas na instalação e analisadas com um detetor semicondutor de Germânio hiper puro acoplado a um sistema eletrônico adequado para espectrometria gama e os resultados processados com o código SAND-BP. As doses devidas a radiação gama e nêutrons foram determinadas utilizando dosímetros termoluminescentes: TLD-400 (sensível a gama); TLD-600 (sensível a nêutrons) e TLD-700 (sensível a gama). Os TLDs foram selecionados e usados para a obtenção das curvas de calibração - resposta do dosímetro versus dose - de cada uma dos três tipos de TLD, as quais foram utilizadas para calcular as doses devidas a nêutrons e gama na posição de amostra. O campo de radiação na posição de irradiação de amostra foi caracterizado fluxo para nêutrons térmicos de 1.39.108 ± 0,12.108 n/cm2s a dose devido a nêutrons térmicos é três vezes maior que as devido a radiação gama, essas medidas comprovam a reprodutibilidade e consistência dos resultados experimentais obtidos. Considerando os resultados obtidos, verificou-se que o campo de nêutrons e radiação gama atende para pesquisa em BNCT. NEUTRONThis work aims to characterize the mixed neutron and gamma field, in the sample irradiation position, in a research installation for Boron Neutron Capture Therapy (BNCT), in the IPEN IEA-R1 reactor. The BNCT technique has been studied as a safe and selective option in the treatment of resistant cancerigenous tumors or considered non-curable by the conventional techniques, for example, the Glioblastoma Multiform a brain cancerigenous tumor. Neutron flux measurements were carried out: thermal, ressonance and fast, as well as neutron and gamma rays doses, in the sample position, using activation foils detectors and thermoluminescent dosimeters. For the determination of the neutron spectrum and intensity, a set of different threshold activation foils and gold foils covered and uncovered with cadmium irradiated in the installation was used, analyzed by a high Pure Germanium semiconductor detector, coupled to an electronic system suitable for gamma spectrometry. The results were processed with the SAND-BP code. The doses due to gamma and neutron rays were determined using thermoluminescent dosimeters TLD 400 and TLD 700 sensitive to gamma and TLD 600, sensitive to neutrons. The TLDs were selected and used for obtaining the calibration curves dosimeter answer versus dose from each of the TLD three types, which were necessary to calculate the doses due to neutron and gamma, in the sample position. The radiation field, in the sample irradiation position, was characterized flux for thermal neutrons of 1.39.108 ± 0,12.108 n/cm2s the doses due to thermal neutrons are three times higher than those due to gamma radiation and confirm the reproducibility and consistency of the experimental findings obtained. Considering these results, the neutron field and gamma radiation showed to be appropriated for research in BNCT
3
Amoush, Ahmad A. "Error Analysis of non-TLD HDR Brachytherapy Dosimetric Techniques." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307105202.
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Munir, Hussan, and Misagh Moayyed. "Systematic Literature Review and Controlled Pilot Experimental Evaluation of Test Driven Development (TDD) vs. Test-Last Development (TLD)." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-4117.
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Context: Test-Driven development (TDD) is a software development approach where test cases are written before actual development of the code in iterative cycles. TDD has gained attention of many software practitioners during the last decade since it has suggested several benefits in the software development process. However, empirical evidence of its dominance in terms of internal code quality, external code quality and productivity is fairly limited. Objectives: The aim behind conducting this study is to explore what has been achieved so far in the field of Test-driven development. The study reports the benefits and limitation of TDD compared to TLD and the outcome variables in all the reported studies along with their measurement criteria. Additionally, an experiment is conducted to see the impact of Test-driven development (TDD) on internal code quality, external code quality and productivity compared to Test-Last development (TLD). Methods: In this study two research methodologies are used specifically systematic literature review according to Kitchenham guidelines and controlled pilot experiment. In systematic literature review number of article sources are considered and used, including Inspec, Compendex, ACM, IEEE Xplore, Science direct (Elsevier) and ISI web of science. A review protocol is created first to ensure the objectivity and repeatability of the whole process. Second, a controlled experiment is conducted with professional software developers to explore the assumed benefits of Test-Driven development (TDD) compared to Test-Last development (TLD). Results: 9 distinct categories related to Test-driven development (TDD) are found that are investigated and reported in the literature. All the reported experiments revealing very little or no difference in internal code quality, external code quality and productivity in Test-Driven development (TDD) over Test-Last development (TLD). However, results were found contradictory when research methods are taken into account because case studies tend to find more positive results in the favor Test-Driven development (TDD) compared to experiments possibly due to the fact that experiment are mostly conducted in artificially created software development environment and mostly with students as a test subjects. On the other hand, experimental results and statistical analysis show no statistically significant result in the favor TDD compared to TLD. All the values found related to number of acceptance test cases passed (Mann-Whitney U test Exact Sig. 0.185), McCabe’s Cyclomatic complexity (Mann-Whitney U test Exact Sig. 0.063), Branch coverage (Mann-Whitney U test Exact Sig. 0.212), Productivity in terms of number of lines of code per person hours (Independent sample Ttest Sig. 0.686), productivity in terms number of user stories implemented per person hours (Independent sample T-test Sig. 0.835) in experiment are statistically insignificant. However, static code analysis (Independent sample T-test Sig. 0.03) result was found statistically significant but due to the low statistical power of test it was not possible to reject the null hypothesis. The results of the survey revealed that the majority of developers in the experiment prefer TLD over TDD, given the lesser required level of learning curve as well as the minimum effort needed to understand and employ TLD compared to TDD Conclusion: Systematic literature review confirms that the reported benefits of TDD development compared to Test-Last development are very small. However, case studies tend to find more positive results in the favor of Test-Driven development (TDD) compared to Test-Last development (TLD). Similarly, experimental findings are also confirming the fact that TDD has small benefits over TLD. However, given the small effect size there is an indication that (Test-Driven development) TDD endorses less complex code compared to Test-Last development (TLD).Systematic literature review confirms that the reported benefits of TDD development compared to Test-Last development are very small. However, case studies tend to find more positive results in the favor of Test-Driven development (TDD) compared to Test-Last development (TLD). Similarly, experimental findings are also confirming the fact that TDD has small benefits over TLD. However, given the small effect size there is an indication that (Test-Driven development) TDD endorses less complex code compared to Test-Last development (TLD).
hassanmunirr@hotmail.com, mm1844@gmail.com
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CHOKKALINGAM, BALACHANDER. "Evaluation of TLD/Predator algorithm : Evaluation of TLD(aka Predator) algorithm used for real-time tracking of unknownobjects in a video stream from eye tracking perspective." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142017.
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Abstract TLD is an award-winning, real-time algorithm for long-term tracking of unknown objects in video streams. The object of interest is defined by a bounding box in a single frame. TLD simultaneously tracks the object, Learns its appearance and Detects it whenever it appears in the video. The result is a real-time tracking that typically improves over time. Long-term tracking of arbitrary objects is a the core problem in many computer vision applications: surveillance, object auto-focus, SLAM, games, HCI, video annotation etc. The following work is done: 1. The OpenTLD algorithm is extended for Multi-Object Tracking. 2. The OpenTLD algorithm is evaluated (i.e. problems with the algorithm, usability of the algorithm), specially from Eye tracking perspective. 3. The OpenTLD algorithm is compared with other tracking algorithm e.g. Mean shift in OpenCV in terms of tracking performance. 4. Some enhancements to the OpenTLD algorithm are made.
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Berry, Richard. "Structure and Functional Regulation of Mammalian BMP-1/TLD Family Proteinases." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501986.
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TAVEIROS, Silvia Fabiane Alves. "Integração de TLD e algoritmo de Haar para rastreamento de faces." Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/2132.
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Previous issue date: 2011A interação natural diz respeito à forma natural como as pessoas se comunicam, seja através de gestos, expressões e movimentos. Pesquisas nessa área tentam construir sistemas que possam compreender essas ações. Sistemas baseados em interação natural são uma tecnologia não intrusiva, a qual não é notada pelo usuário no cotidiano e tem um bom tempo de resposta de processamento. As interfaces atuais tentam se aproximar cada vez mais das perspectivas humanas, sendo ainda limitadas por tecnologias de entrada de dados não adequadas. Dentro deste contexto se encontram as técnicas de realidade aumentada sem marcadores (MAR), que realizam o rastreamento e o registro de objetos virtuais em cenas reais sem a utilização de elementos intrusivos às cenas, fator que possibilita sua utilização em ambientes pouco controlados e tornam sua definição mais complexa. Um ramo de aplicação em destaque nos meios acadêmico e industrial é o rastreamento de faces tanto do ponto de vista de aplicações de MAR quanto de sistemas de segurança, devido à possibilidade de facilitar o reconhecimento automático de faces em cenários de tempo real. A capacidade de estimar a pose da cabeça de outra pessoa é uma habilidade humana comum, mas que representa um desafio para os sistemas de visão computacional. Um rastreador de posição de face ideal deve ser invariante a rotação e escala, ser robusto, inicializar automaticamente, suportar oclusão parcial e total, além de mudança de iluminação e movimentos de cabeça rápidos. Neste trabalho desenvolvemos um sistema de rastreamento de face interativo que utiliza técnicas 2D, uma câmera e características naturais da cena para se obter um rastreamento que contenha as requisições necessárias por um estimador de face ideal. O algoritmo utilizado para o rastreamento de face de longo prazo integrou duas técnicas para obtenção de uma aplicação robusta e em tempo real: algoritmo de Haar e TLD (tracking learnig detect), sendo que o primeiro é responsável pela inicialização automática da face no ambiente, enquanto o segundo utiliza técnicas de aprendizado supervisionado, usando os próprios erros para aprimorar o rastreamento
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Luboya, Silhady Tshitende. "Response of Footbridges equipped with TLD : A numerical and experimental assessment." Thesis, KTH, Bro- och stålbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278563.
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In recent years, an increase to design slender and aesthetically-pleasing structures have resulted in some structures having a low natural frequency. This is because the design calculation did not meet the requirement of serviceability performance. Structures can experience excessive vibrations when they are subjected to different types of dynamic loading. A device can be installed to prevent these vibrations.In this thesis, we study the response of buildings and lateral vibrations of footbridges equipped with Tuned Liquid Damper. The aim is to mitigate the first mode of vibration. Tuned Liquid Damper consists of a container in rectangular, cylindrical or arbitrary shape partially filled with shallow liquid, most often water is used as a regulating device system. The design properties of Tuned Liquid Damper is introduced and it is based on the analogyof the most popular damper, Tuned Mass Damper.An experimental study of a building frame model with four floors is conducted to validate the numerical results obtained from the simulation of the model in ANSYS. The linear and non-linear analysis are performed through a system coupling between Ansys mechanical and Fluent solver. The simulation results obtained are in good agreement with the experimental results.A parametric study is conducted with a simply supported steel footbridge. It is a 45 m long span with 3 m width and the flexural rigidity is modified to get the lateral vibration mode. The first lateral natural frequency obtained is 0.713 Hz. The load case for the study considered is according to Sétra guide. The variable parameters studied is the Tuned Liquid Damper water mass ratios: 0.7%, 1.0%, 2.0%, 3.0% and 4.0%. The results show a satisfactory performance of the footbridge model equipped with Tuned Liquid Damper. The accelerations are below 0.1 m/s2 which satisfied the requirement of 0.15 m/s2.
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Prause, Christopher Alvin. "External detection and measurement of inhaled radionuclides using thermoluminescent dosimeters." Texas A&M University, 2006. http://hdl.handle.net/1969.1/5021.
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Many radiation detection programs use bio-assays, whole-body counters, or air
sampling to estimate internal doses. This study examines the possibility of using a
common external thermoluminescent dosimeter (TLD) badge as a device for detecting
inhaled radionuclides through radiation those radionuclides emit which escape the body.
The three common radionuclides chosen for modeling due to their varying decay modes
and use or production in the nuclear industry were Cs-137, U-238, and Sr-90. These three
radionuclides were modeled for biological and radiological removal in the dynamic
systems modeling program of STELLA II and modeled for TLD dose per organ in the
geometry and radiation simulation program of MCNP.
The results show that none of the nuclides in the study can be detected at air
concentrations below regulatory limits for acute inhalation exposures. To achieve a
detectable dose from an 8-hour work exposure, with a 90-day wait until the TLD is read,
the airborne concentrations for the inhalation classes that produced the most dose per Bq
would be 37.9 kBq/m3, 146 MBq/m3, and 1.67 MBq/m3 for Cs-137, U-238, and Sr-90,
respectively.
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PAIVA, FABIO de. "Estudo das respostas de TLD tipo LiF para caracterização de campos mistos." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26930.
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A Terapia por Captura de Nêutrons, NCT (Neutron Capture Therapy) é uma técnica radioterápica em que a energia útil do tratamento vem da energia liberada em uma reação nuclear e não do feixe primário, como comumente utilizado em outros procedimentos radioterápicos. O Boro, por constituir-se em um elemento de baixa toxicidade e por apresentar um isótopo (10B) com alta seção de choque para a reação 10B(n,α)7Li tem sido o elemento mais utilizado nas pesquisas que visam o aprimoramento e a promoção desta técnica, derivando daí o termo BNCT (Boron Neutron Capture Therapy). Para fins de pesquisa em BNCT foi construída ao longo de um dos extratores de feixes (BH - Beam Hole) do reator IEA-R1 uma instalação, onde filtros e moderadores são posicionados entre o núcleo do reator e a posição de irradiação com o objetivo de modular o feixe de irradiação, otimizando a componente útil do feixe, os nêutrons térmicos, e reduzindo os contaminantes, raios gama e nêutrons em outras faixas energéticas. Tem-se realizado estudos visando a implementação de melhorias na caracterização e otimização do feixe obtido nesse arranjo instalado no BH-3. Atualmente a monitoração dos nêutrons é feita através de folhas de ativação, e a componente gama pelo TLD-400. Uma nova metodologia de monitoração tem sido estudada pelo grupo. A referida técnica consiste em usar TLDs de tipos diferentes, ou seja, que possuam sensibilidades distintas aos nêutrons térmicos, em virtude de diferenças na concentração dos isótopos de Lítio. No estudo dessa nova metodologia têm sido usados os TLD-600 e TLD-700. Este trabalho propõe uma metodologia usando o par TLD-100 e TLD-700. Inicialmente foi verificada a reprodutibilidade das respostas dos TLDs 700, 400 e 100 frente a campos gama puro e campos mistos, gama e nêutron. Campos estes obtidos em arranjos usando fontes de 60Co e 241AmBe. A partir de simulações usando o VI MCNP5 foi projetado e construído um Irradiador de campos mistos, que permitiu expor os dosímetros em campos mistos com diferentes espectros energéticos. As condições criadas no irradiador permitiram verificar, como a resposta do TLD é modificada pelas mudanças no espectro energético de um campo misto gama e nêutrons de baixo fluxo. O irradiador de campo misto permitiu condições para estabelecer uma relação entre o formato da curva termoluminescente e a composição do campo misto. A relação estabelecida relaciona o fluxo relativo e a razão entre a resposta das duas regiões de interesse dos TLDs 700 e 100. A partir de campos mistos com condições controladas, esse trabalho permitiu verificar a viabilidade do uso do par de TLD-100 e TLD-700 para monitoração de nêutrons térmicos na instalação de BNCT.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Hultqvist, Martha. "Analysis of the uncertainties in the IAEA/WHO TLD postal dose audit programme." Thesis, Stockholm University, Medical Radiation Physics (together with KI), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7219.
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The International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO) operate the IAEA/WHO TLD postal dose audit programme. The purpose of the programme is to verify the beam calibration in radiotherapy centres in developing countries and to check the Secondary Standards Dosimetry Laboratories (SSDLs). Thermoluminescence dosimeters (TLDs) are used as transfer dosimeters and the evaluation of these are done at the IAEA Dosimetry Laboratory. In the present work the uncertainties in the process of dose determination from TLD readings have been evaluated.
The analysis comprises the TLD reading reproducibility, uncertainties in the calibration coefficient, and uncertainties in factors correcting for fading of TL signal, influence of TLD holder, energy response and dose response non-linearity. The individual uncertainties were combined to estimate the total uncertainty in the evaluated dose from TLD readings. Experimental data from 2001-2005 were used in the analysis.
The total uncertainty has been estimated to be 1.2 % for irradiations with 60Co -rays and 1.6 % for irradiations with high-energy X-rays. Results from irradiations by the Bureau International des Poids et Mesures (BIPM), Primary Standard Dosimetry Laboratories (PSDLs), Secondary Standard Dosimetry Laboratories (SSDLs) and reference centres compare favourably with the estimated uncertainties.
The largest uncertainty components are in the energy correction factor (for high-energy X-rays) with a value of 1.1 % and in the dose response non-linearity correction factor with a value of 0.9 %.
It has been shown that the acceptance limits of 5 % for TLD results of hospitals and 3.5 % for SSDLs are justified when related to the uncertainties in the dose calculations and the uncertainty in the determination of absorbed dose to water at the centre, as discussed in IAEA TRS-398 (IAEA, 2000), provided that it is followed.
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SANTOS, Joelan Angelo de Lucena. "Deconvolução de espectros neutrônicos obtidos com o sistema EB-TLD utilizando algoritmos genéticos." Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/9318.
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Previous issue date: 2011Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A variabilidade do espectro neutrônico dentro de um mesmo ambiente torna necessária a caracterização da distribuição espectral em função da energia e para a realização de tal tarefa, a espectrometria neutrônica exerce papel fundamental para a determinação do fluxo de nêutrons (E(E)). Uma informação precisa permite que sejam estabelecidas grandezas radiológicas relacionadas àquele espectro investigado, sendo necessário, no entanto, uma série de medidas com um sistema espectrométrico que permita cobrir um amplo intervalo de energia e cuja resposta seja preferencialmente isotrópica, sendo um dos sistemas mais utilizados para a realização dessa tarefa, o sistema espectrométrico de esferas de Bonner. Um dos maiores problemas relacionados à espectrometria neutrônica é o processo de análise dos dados, conhecido como deconvolução. A maioria dos trabalhos desenvolvidos na implementação de novas técnicas desse processo, utiliza os dados obtidos com o cintilador de 6LiI(Eu). No entanto, características relacionadas ao tempo morto deste instrumento fazem com que o mesmo não seja tão eficiente quando utilizado em campos neutrônicos de alto fluxo. Uma alternativa para solução deste problema é a utilização de detectores termoluminescentes (TLD), porém os códigos mais utilizados não disponibilizam uma matriz resposta específica para deconvoluir a informação obtida por esses materiais, o que torna o desenvolvimento de uma matriz resposta específica importante para caracterizar adequadamente a resposta obtida pelos mesmos, o que torna o desenvolvimento de uma matriz resposta fundamental para caracterizar o espectro obtido por esses detectores. Este trabalho utiliza uma técnica de Inteligência Artificial (IA) denominada de Algoritmo Genético (AG), que utiliza modelos matemáticos bioinspirados a fim de induzir um processo evolutivo da resposta, e por meio da implementação de uma matriz específica para deconvoluir os dados obtidos da combinação de TLDs inseridos no sistema de esferas de Bonner, como detectores de nêutrons térmicos, com o objetivo de caracterizar o espectro neutrônico em função da energia. Os resultados obtidos com esse método se mostraram concordantes com o código BUNKI/UTA, utilizado para comparação. Tal fato viabiliza a utilização de algoritmos genéticos em processos de deconvolução do espectro neutrônico quando se utiliza TLD
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Santos, Lindomar Soares dos. "Implementação de um sistema dosimétrico termoluminescente para utilização em dosimetria in vivo em teleterapia com feixes de fótons de energia alta." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-12052008-150030/.
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A dosimetria in vivo é a verificação final da dose real administrada ao paciente e tornou-se atualmente necessária devido ao aumento da complexidade e da sofisticaçã das técnicas radioterápicas. A finalidade deste trabalho foi apresentar, verificar e avaliar alguns procedimentos básicos, práticos e viáveis para a implementação da dosimetria in vivo com dosímetros termoluminescentes na verificação de dose em um serviço de radioterapia. Para o estabelecimento do sistema dosimétrico termoluminescente, alguns testes e medições foram realizados, incluindo o procedimento de inicialização, a determinação da homogeneidade do grupo de dosímetros, a determinação do fator de correção individual de cada dosímetro, a determinação da faixa de linearidade do sistema e do coeficiente de calibração. Medições em um objeto simulador antropomórfico foram realizadas para garantir que os métodos utilizados são satisfatórios antes que estes fossem usados para medições em pacientes. Medições de dose em um paciente foram feitas em um tratamento de câncer de próstata. A metodologia proposta pode ser usada como parte de um programa de garantia de qualidade em um serviço de radioterapia.In vivo dosimetry is the ultimate check of the actual dose delivered to an individual patient and has become a procedure actually necessary due to increasing complexity and sophistication of radiotherapy techniques. The purpose of the present work was to present, verify and evaluate some basic, practical and viable procedures for the implementation of in vivo dosimetry with thermoluminescent dosimeters for patient dose verification at a radiotherapy service. For the setting up of the thermoluminescent dosimetric system, several tests and measurements were carried out including the initialisation procedure, the determination of the batch homogeneity, the determination of individual correction factor of each dosimeter, the determination of linearity range of the system and its calibration coefficients. Anthropomorphic phantom measurements were taken to ensure that the methods are satisfactory before they are used for patients measurements. Patient dose measurements were carried out in a prostate cancer treatment. The proposed methodology can be used as a part of a quality assurance program in a radiotherapy service.
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BONFA, CIZENANDO MORELLO. "A FACE RECOGNITION SYSTEM FOR VIDEO SEQUENCES BASED ON A MULTITHREAD IMPLEMENTATION OF TLD." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35312@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
A identificação facial em vídeo é uma aplicação de grande interesse na comunidade cientifica e na indústria de segurança, impulsionando a busca por técnicas mais robustas e eficientes. Atualmente, no âmbito de reconhecimento facial, as técnicas de identificação frontal são as com melhor taxa de acerto quando comparadas com outras técnicas não frontais. Esse trabalho tem como objetivo principal buscar métodos de avaliar imagens em vídeo em busca de pessoas (rostos), avaliando se a qualidade da imagem está dentro de uma faixa aceitável que permita um algoritmo de reconhecimento facial frontal identificar os indivíduos. Propõem-se maneiras de diminuir a carga de processamento para permitir a avaliação do máximo número de indivíduos numa imagem sem afetar o desempenho em tempo real. Isso é feito através de uma análise da maior parte das técnicas utilizadas nos últimos anos e do estado da arte, compilando toda a informação para ser aplicada em um projeto que utiliza os pontos fortes de cada uma e compense suas deficiências. O resultado é uma plataforma multithread. Para avaliação do desempenho foram realizados testes de carga computacional com o uso de um vídeo público disponibilizado na AVSS (Advanced Video and Signal based Surveillance). Os resultados mostram que a arquitetura promove um melhor uso dos recursos computacionais, permitindo um uso de uma gama maior de algoritmos em cada segmento que compõe a arquitetura, podendo ser selecionados segundo critérios de qualidade da imagem e ambiente onde o vídeo é capturado.
Face recognition in video is an application of great interest in the scientific community and in the surveillance industry, boosting the search for efficient and robust techniques. Nowadays, in the facial recognition field, the frontal identification techniques are those with the best hit ratio when compared with others non-frontal techniques. This work has as main objective seek for methods to evaluate images in video to look for people (faces), assessing if the image quality is in an acceptable range that allows a facial recognition algorithm to identify the individuals. It s proposed ways to decrease the processing load to allow a maximum number of individuals assessed in an image without affecting the real time performance. This is reached through analysis of most the techniques used in the last years and the state-of-the-art, compiling all information to be applied in a project that uses the strengths of each one and offset its shortcomings. The outcome is a multithread platform. Performance evaluation was performed through computational load tests by using public videos available in AVSS ( Advanced Video and Signal based Surveillance). The outcomes show that the architecture makes a better use of the computational resources, allowing use of a wide range of algorithms in every segment of the architecture that can be selected according to quality image and video environment criteria.
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Hernandez, Pete Jevon. "Response comparison of an optically stimulated luminescent dosimeter, a direct-ion storage dosimeter, and a thermoluminescence dosimeter." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2979.
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Scarcella, Meredith Lyn. "Verification of TLD/MCNP depth-dose distribution of a ¹²³Pd IVBT source using radiochromic film." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17937.
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Lannes, Itembu. "Empirical measurements to ensure compliance with post therapy dose constraints to family members of radioiodine therapy patients." Thesis, Stockholm University, Medical Radiation Physics (together with KI), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7214.
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Radioiodine has been used in nuclear medicine for the treatment of thyroid diseases such as Thyroid Cancer and Thyrotoxicosis for many years. The treatment renders the patient radioactive. To minimize the dose to the patients’ relatives and the general public, restric-tions are imposed on the behaviour of the patient. This project presents the person dose equivalents actually received by family members of radioiodine patients following such restrictions. The family members wore hospital ID-bands on left and right wrists for up to four weeks. Each ID-band contained two LiF: Mg, Ti Thermo Luminescence Dosimeters (TLD) calibrated to measure air kerma. The TLDs were analysed and a total person dose equivalent received by the relative was calculated from the measured air kerma values. The results were compared to the dose constraints imposed by The Swedish Radiation Protection Authority (SSI FS 2000:3) in order to confirm that the new set of restrictions used at Karolinska University Hospital Huddinge maintains the dose to family members below the applicable limits.
A total number of 22 relatives were recruited, 8 elderly, 7 adults and 7 children. Of the recruited relatives 4 (2 adults, 2 children) were excluded from the study as they had lost their dosimeter ID-bands or had other reasons not to participate in the study. This leaves the number of relatives used for data analysis at 18 individuals (8 elderly, 5 adults and 5 children) with a min age of 10 years and max age of 80 years.
The observed average person dose equivalent of 0.43 mSv (max, 1.27; min, 0.12) indi-cates that the new method of individualised restriction used at Karolinska University Hospital Huddinge work as desired in keeping the dose to family members at an accept-able level. The accuracy of the clinical study has been shown to depend greatly on the method by which the dose is investigated but also on the properties of the TLD material used. There is a potential underestimation of air kerma due to fading of up to 30 %. In addition there are contributing uncertainties from both the calibration method and the conversion to person dose equivalent with the combined uncertainty estimated to be 14%.
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Toye, Warren, and michelletoye@optusnet com au. "HDR Brachytherapy: Improved Methods of Implementation and Quality Assurance." RMIT University. Applied Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080528.091630.
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This thesis describes experimental work performed (1998-2001) during the author's involvement with the Brachytherapy group at the Peter MacCallum Cancer Centre (PMCC), where he was employed by its Department of Physical Sciences and subsequent modeling and analytical studies. When PMCC added HDR brachytherapy to its radiation therapy practice, an existing operating suite was considered the ideal location for such procedures to be carried out. The integration of brachytherapy into the theatre environment was considered logical due to the relatively invasive nature of brachytherapy techniques and the availability of medical equipment. This thesis contains the detailed study of three key Research Questions involved in clinical aspects relating to quality assurance of an HDR brachytherapy practice. An investigative chapter is dedicated to the pursuit of each of the Research Questions. The first question asked
Is the novel approach to using modular shielding combined with time and distance constraints adequately optimized during HDR brachytherapy? In order to establish optimal clinical practices, this project evaluates the effectiveness of additional shielding added to the modular shielding system without modification of the previously determined time and distance constraints for PMCC staff, other patients, and member of the public. The DOSXYZnrc user code for the EGSnrc Monte Carlo radiation transport code has been used to model exposure pathways to strategic locations used for measurement in and around the operating theatre suite. Modeling allowed exposure pathways to various areas with the facility to be tested without the need to use real sources. The second Research Question asked
How well is dose anisotropy characterized in the near field range of the clinic's HDR 192Ir source? This study experimentally investigated the anisotropy of dose around a 192Ir HDR source in a water phantom using MOSFETs as relative dosimeters. In addition, modeling using the DOSRZnrc user code for the EGSnrc Monte Carlo radiation transport code was performed to provide a complete dose distribution consistent with the MOSFET measurements. Measurements performed for radial distances from 5 to 30 mm extend the range of measurements to 5 mm which has not been previously reported for this source construction. The third Research Question is aimed at the patient level. Is the dose delivered to in vivo dosimeters, located within critical anatomical structures near the prostate, within acceptable clinical tolerance for a large group of HDR prostate patients? An in vivo dosimetry technique employing TLDs to experimentally measure doses delivered to the urethra and rectum during HDR prostate brachytherapy was investigated. Urethral and rectal in vivo measurements for 56 patients have been performed in the initial fraction of four-fraction brachytherapy boost. In the absence of comparable in vivo data, the following local corrective action level was initially proposed: more than 50% of the prostatic urethra receiving a dose 10% beyond the urethral tolerance. The level for investigative action is considered from the analyses of dose differences between measured data and TPS calculation.
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Pautsch, Maren [Verfasser]. "Untersuchung zur Optimierung der physikalisch-technischen Parameter beim Auswerten und Tempern von Thermolumineszenzdosimetern des Typs TLD-100H / Maren Pautsch." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2012. http://d-nb.info/1024500853/34.
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Baptista, Cláudia Gonçalves. "Correção de heterogeneidades para feixes de fótons de 6 MeV: comparações entre algoritmos de cálculo e medidas com TLD." Universidade Tecnológica Federal do Paraná, 2009. http://repositorio.utfpr.edu.br/jspui/handle/1/1047.
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O presente trabalho mostra as diferenças de dose encontradas em meios de diferentes densidades eletrônicas, simulando tecido adiposo, muscular, ósseo e cavidade aérea, comparando medidas experimentais com feixe de fótons de 6 MeV e valores resultantes de algoritmos de cálculo existentes em um sistema de planejamento radioterápico. Para isso foram utilizados dosímetros termoluminescentes posicionados acima, dentro e abaixo de cada objeto simulador e medidos os perfis de dose ao longo do eixo longitudinal e do eixo transversal. As simulações computacionais foram realizadas com dois algoritmos de cálculo presentes na versão 8.5 do sistema de planejamento Eclipse: o Pencil Beam Convolution e o Analytical Anisotropic Algorithm. Comparando doses em um mesmo ponto, com e sem heterogeneidades, foram encontradas diferenças percentuais de até 12%, quando os algoritmos de correção de heterogeneidades não foram aplicados. Analisando essas comparações, pode-se observar também qual dos algoritmos de cálculo mais se aproxima dos valores experimentais, propondo ser o algoritmo de maior confiabilidade.This work presents the dose variations obtained when phantoms of different electronic densities were used, simulating fat tissue, muscle, bones and air cavities, comparing experimental data with a 6 MeV photon beams and the values calculated by the treatment planning system algorithms. Thermoluminescent dosimeters were positioned above, inside and below each phantom measuring the dose along the depth and along a profile. The computational simulation was done by two algorithms that are part of Eclipse version 8.5: Pencil Beam Convolution and Analytical Anisotropic Algorithm. Comparing doses at the same point, with and without heterogeneities, percentages of 12% were found when heterogeneity correction was not used. These results also show which of the algorithms approaches better to the experimental values, becoming more reliable.
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Ezzo, Issa. "Determination of the conversion factor for the estimation of effective dose in lungs, urography and cardiac procedures." Thesis, Stockholm University, Medical Radiation Physics (together with KI), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8520.
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Patient dose in diagnostic radiology is usually expressed in terms of organ dose and effective dose. The latter is used as a measure of the stochastic risk. Determinations of these doses are obtained by measurements (Thermoluminescent dosemeters) or by calculations (Monte Carlo simulation).
Conversion factors for the calculation of effective dose from dose-area product (DAP) values are commonly used to determine radiation dose in conventional x-ray imaging to realize radiation risks for different investigations, and for different ages. The exposure can easily be estimated by converting the DAP into an effective dose.
The aim of this study is to determine the conversion factor in procedures by computing the ratio between effective dose and DAP for fluoroscopic cardiac procedures in adults and for conventional lung and urography examinations in children.
Thermoluminescent dosemeters (TLD) were placed in an anthropomorphic phantom (Alderson Rando phantom) and child phantom (one year old) in order to measure the organ dose and compute the effective dose. A DAP meter was used to measure dose-area product.
MC calculations of radiation transport in mathematical anthropomorphic phantoms were used to obtain the effective dose for the same conditions with DAP as input data.
The deviation between the measured and calculated data was less than 10 %. The conversion factor for cardiac procedures varies between 0.19 mSvGy-1 cm-2 and 0.18 mSvGy-1 cm-2, for TLD respective MC. For paediatric simulation of a one year old phantom the average conversion factor for urography was 1.34 mSvGy-1 cm-2 and 1,48 mSvGy-1cm-2 for TLD respective MC. This conversion factor will decrease to 1.07 mSvGy-1 cm-2 using the TLD method, if the new ICRP (ICRP Publication 103) weighting factors were used to calculate the effective dose.
For lung investigations, the conversion factor for children was 1.75 mSvGy-1 cm-2 using TLD, while this value was 1.62 mSvGy-1 cm-2 using MC simulation. The conversion value increased to 2.02 mSvGy-1 cm-2 using ICRP’s new recommendation for tissue weighting factors and child phantom.
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Amharrak, Hicham. "Développement et optimisation de méthodes de mesures d'échauffements nucléaires et de flux gamma dans les réacteurs expérimentaux : identification, maîtrise, traitement et réduction des incertitudes associées." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4705.
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L'objectif de cette thèse vise à mettre au point et à améliorer les méthodes de mesures d'échauffements nucléaires auprès des maquettes critiques du CEA-Cadarache EOLE et MINERVE, au moyen de détecteurs thermo-luminescents (TLD), de détecteurs à luminescence optiquement stimulée (OSLD – nouvellement mis en œuvre dans le cadre de ce travail de thèse) et d'une chambre d'ionisation. Il s'agit d'identifier, de hiérarchiser, de traiter et enfin de réduire les différentes sources d'incertitudes et de biais systématiques associés à la mesure.Une série d'expériences a été mise en place dans le réacteur MINERVE. Les mesures ont été réalisées dans un environnement en aluminium ou en hafnium à l'aide d'un nouveau protocole : les TLD ont été étalonnés individuellement, la répétabilité de la mesure a été évaluée expérimentalement et les lois de chauffe des TLD ont été optimisées, conduisant à une réduction des incertitudes de mesures. Des mesures de gammas émis de façon différée après arrêt du réacteur MINERVE ont également été réalisées : les résultats obtenus montrent un bon accord des mesures avec les trois types de détecteurs utilisés.L'interprétation de ces mesures nécessite des calculs pour tenir compte des facteurs de correction, liés à l'environnement et au type de détecteurs utilisés. Ainsi, des corrections de la contribution des neutrons à la dose totale intégrée par les détecteurs ont été évaluées à l'aide de deux méthodes de calcul. Ces corrections ont été obtenues sur la base de simulations Monte Carlo couplées neutron-gamma et gamma-électron à l'aide du code MCNPThe objective of this thesis is to develop and to improve the nuclear heating measurement methods in MINERVE and EOLE experimental reactors at CEA-Cadarache, using thermo-luminescent detectors (TLD), optically stimulated luminescence detectors (OSLD – newly implemented in the context of this thesis) and an ionization chamber. It is to identify, prioritize, treat and reduce the various sources of uncertainty and systematic bias associated with the measurement.A series of experiments was set up in the MINERVE reactor. The measurements were carried out in an aluminum or hafnium surrounding using a new procedure methodology. The TLD are calibrated individually, the repeatability of the measurement is experimentally evaluated and the laws of TLD heat are optimized. The measurements of the gamma emitted, with a delay (delayed gamma) after shutdown of the MINERVE reactor, were also carried out using TLD and OSLD detectors with the aluminum pillbox as well as by ionization chamber. The results show a good correlation between the measurements recorded by these three detectors.The interpretation of these measurements needs to take account the calculation of cavity correction factors related to the surrounding and the type of detector used. Similarly, the correction due to the neutrons contributions to the total dose integrated by the detectors are evaluated with two calculation methods. These corrections are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles using the MCNP
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Santos, Cristiane Nascimento. "Estudo de vidros metafosfatos do sistema KPO3 Al(PO3)3 e sua aplicação em dosimetria termoluminescente." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-09122013-110749/.
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Vidros com composição de aluminofosfato vêm sendo estudados por apresentarem elevada durabilidade química. O objetivo do presente trabalho foi estudar as propriedades térmicas e estruturais do sistema vítreo xKPO3 - (100-x)Al(PO3)3, para x = 10, 30 e 50 (% em mol), a fim de determinarmos uma composição que apresentasse uma boa resposta termoluminescente (TL) quando dopada com íons de manganês. As matrizes vítreas não dopadas apresentaram uma boa estabilidade vítrea frente a devitrificação. As fases cristalizadas no sistema foram determinadas por difração de raios X e espectroscopia micro-Raman como KAIP2O7 e AI(PO3)3. A composição KAI(PO3)4 (x = 50 %) apresentou elevada durabilidade química e o menor ponto de fusão, o que facilitou o processo de preparação. Essa composição foi então utilizada para as dopagens com íons de manganês. A composição com 1,0 % em mol de MnO2 apresentou a melhor resposta TL. As propriedades dosimétricas estudadas mostraram que o vidro possui uma resposta linear para raios X no intervalo de dose de 2 mGy a 80 Gy, podendo então ser utilizado em dosimetria clínica e pessoalAluminophosphate glasses have been studied because of their good chemical resistance. The main purpose of this work was to investigate the structural and thermal properties of glasses in the system xKPO3 - (100-x)AI(PO3)3, with x = 10, 30 e 50 (mol %). The goal was to determine a composition which provided a good thermoluminescence response (TL) when doped with manganese ions. The undoped vitreous matrixes showed a good thermal stability against devitrification. The crystalline phases were identified by X ray diffraction and micro-Raman spectroscopy as KAIP2O7 and Al(PO3)3. The composition KAI(PO3)4 (x = 50 %) showed high chemical resistance and lower melting point. This composition was used for doping with manganese ions. The composition of 1,0 mol % of MnO2 showed the best TL response. The dosimetric properties showed that this glass has a linear response for X-rays in the dose interval of 2 mGy to 80 Gy, and it is a promising material for application as a TLD dosimeter
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Ruana, Vidal do Nascimento Samira. "Dosimetria termoluminescente do quartzo natural de Solonópole (CE) para aplicação em radiodiagnóstico." Universidade Federal de Pernambuco, 2010. https://repositorio.ufpe.br/handle/123456789/9190.
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Previous issue date: 2010Conselho Nacional de Desenvolvimento Científico e Tecnológico
Dosímetros termoluminescentes (TL) são muito empregados para medir doses de radiação ionizante, sobretudo em dosimetria clínica e ambiental. Diversas pesquisas têm sido feitas buscando desenvolver materiais TL mais sensíveis para aplicação na dosimetria de baixas doses. Neste contexto, trabalhos recentes mostraram a possibilidade de medir doses da ordem de 0,1 mGy utilizando o quartzo natural de Solonópole (CE) após um procedimento de sensibilização com tratamentos térmicos e altas doses de radiação gama. Entretanto, para que este material possa ser utilizado como dosímetro TL é necessário estudar de forma sistemática suas propriedades dosimétricas. Assim, este trabalho tem como objetivo estudar as propriedades dosimétricas do quartzo natural de Solonópole (CE) sensibilizado e investigar sua aplicabilidade como dosímetro TL em exames de radiodiagnóstico convencional. Para isso, foram produzidos 95 discos de quartzo sensibilizado (6 mm x 1 mm). A variação da reprodutibilidade da resposta TL foi avaliada a partir de cinco irradiações com 10 mGy com uma fonte de raios gama de 137Cs. Para investigar a estabilidade da resposta TL deste material, os lotes foram irradiados nas mesmas condições e armazenados na ausência de luz por até 120 dias. Para estudar o comportamento da resposta TL em função do kerma no ar, as amostras foram irradiadas com raios gama de uma fonte de 137Cs com valores de kerma no ar entre 0,01 e 100 mGy. A dependência energética foi determinada a partir dos coeficientes angulares das curvas de calibração obtidas com feixes de raios X de espectro estreito (de 16 a 118 keV), e raios gama de 137Cs e 60Co. Por sua vez, a dependência angular foi determinada irradiando as amostras com feixes de raios X para ângulos entre -90° e 90°. Posteriormente, as amostras de quartzo e os dosímetros TLD-100 foram posicionados sobre um simulador antropomórfico de tórax, no centro geométrico do feixe de raios X. Estas medidas foram utilizadas para determinar o kerma no ar na superfície de entrada. O estudo das propriedades dosimétricas permitiu observar que as amostras de quartzo apresentaram reprodutibilidade, estabilidade da resposta TL e dependência angular equivalentes àquelas do TLD-100. A partir das curvas de resposta TL em função do kerma no ar, constatou-se que a resposta TL do quartzo é linear para doses entre 0,01 e 100 mGy. Além disso, observou-se que as amostras de quartzo permitiam determinar valores de kerma no ar três vezes mais baixos quando comparado aos do TLD-100. A dependência energética máxima destas amostras foi três vezes maior que a do TLD-100 e não há dependência angular para o intervalo de -45° a 45°. A sensibilidade relativa à do TLD-100 destas amostras varia entre 2 e 5 de acordo com a energia da radiação incidente. Ao utilizar estas amostras para a determinação do kerma no ar na superfície de entrada, elas apresentaram boa equivalência com os dados encontrados com o TLD-100. Conclui-se que o quartzo sensibilizado de Solonópole caracterizado pode ser empregado de maneira confiável para medir o kerma no ar na superfície de entrada em exames de raios X de tórax
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Broadhead, Dawn. "Large scale entrance surface dose survey and organ dose measurements during diagnostic radiology using the Harshaw 5500 and 6600 TLD systems." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366517.
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Ranaei-Siadat, Seyed-Ehsan. "Structure, stabilité et interactions de l’ARNtm avant liaison au ribosome." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05P605.
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Habitzreuter, Ângela Beatriz. "Implementação da irradiação de corpo inteiro em radioterapia." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-02082011-130937/.
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Ao implementar uma técnica de tratamento, as características do feixe nas condições de irradiação precisam ser bem conhecidas e estudadas. Cada um dos parâmetros utilizados para cálculo de dose deve ser medido e validado antes da utilização dos mesmos na rotina clínica. Isso se torna ainda mais necessário quando se tratam de técnicas especiais. Neste trabalho estão descritos todos os parâmetros e medidas necessárias para a implementação da irradiação de corpo inteiro numa instalação projetada para tratamentos convencionais, e que faz uso de geometrias não convencionais para gerar os tamanhos de campos alargados. Além disso, são apresentados os dados de comissionamento desta modalidade no Hospital das Clínicas de São Paulo utilizando a comparação de três tipos de detectores para medidas de dose de entrada durante tratamentos de irradiação de corpo inteiro.Before implementing a treatment technique, the characteristics of the beam under irradiation conditions must be well acknowledged and studied. Each one of the parameters used to calculate the dose has to be measured and validated before its utilization in clinical practice. This is particularly necessary when dealing with special techniques. In this work, all necessary parameters and measurements are described for the total body irradiation implementation in facilities designed for conventional treatments that make use of unconventional geometries to generate desired enlarged field sizes. Furthermore, this work presents commissioning data of this modality at Hospital das Clínicas of São Paulo using comparison of three detectors types for measurements of entrance dose during total body irradiation treatment.
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BEZERRA, Jairo Dias. "Dosimetria termoluminescente na avaliação da dose “indoor” das residências do Município de São José de Espinharas-PB." Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/16245.
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CAPES
Estudos radioecológicos com dosimetria ambiental vêm sendo realizados mundialmente, principalmente para avaliar os níveis de radiação natural oriundos dos radionuclídeos primordiais presentes na crosta terrestre, tais como o 40K e os radionuclídeos das séries do 238U e do 232Th. Estes radionuclídeos são os que mais contribuem para a exposição gama externa em ambientes fechados, principalmente quando localizados em áreas que apresentam níveis diferenciados de radiação natural. Neste contexto, o presente trabalho teve como objetivo, determinar as taxas de doses efetivas externas dentro das residências, dose “indoor”, localizadas próximas à jazida de urânio do município de São José de Espinharas no estado da Paraíba, que contêm altos níveis de radionuclídeos terrestres, os quais constituem os Materiais Radioativos de Ocorrências Naturais (NORM). Para caracterizar o estudo radiométrico, foram instalados 178 conjuntos de dosímetros termoluminscentes, com três TLDs do tipo LiF:Mg, Ti (Fluoreto de Lítio dopado com Magnésio e Titânio) nos quartos das residências, sendo substituídos a cada 90 dias. Toda pesquisa foi realizada no período de dezembro de 2012 a novembro de 2014. As taxas de doses efetivas ambientais calculadas para São José de Espinharas variaram de 0,71 a 2,07 mSv.a-1, com média de 0,90 mSv.a-1. Municípios adjacentes à área de estudo também foram monitorados no referido estudo, destacando-se: São Mamede, São José do Sabugi, Patos e Santa Luzia com valores intervalares e médias de 0,77 a 1,41 mSv.a-1 (0,94 mSv.a-1); 0,90 a 1,67 mSv.a-1 (1,13 mSv.a-1); 0,77 a 0,93 mSv.a-1 (0,87 mSv.a-1) e 1,10 a 1,27 mSv.a-1 (1,18 mSv.a-1), respectivamente. A média geral do referido estudo ficou em torno de 0,99 0,10 mSv.a-1, correspondendo a um valor médio que é 2,5 vezes superior ao estimado para ambientes fechados conforme o Comitê Científico das Nações Unidas para os Efeitos das Radiações Atômicas (UNSCEAR) que é 0,41 mSv.a-1. Estes valores conferem aos municípios, influências exclusivas de materiais radioativos de ocorrências naturais devido à formação geológica da região, quando levado em consideração os níveis desses radionuclídeos. Observa-se que os resultados obtidos nesta monitoração radioecológica, não permite propor nenhuma condição de contaminação "indoor" sem antes monitorar a água, os alimentos, os materiais de construção, como também os habitantes para se predizer qualquer condição de risco real que esteja associada a população desses municípios.
Radioecological studies of environmental dosimetry have been conducted worldwide, mainly to assess the natural levels of radiation coming from the primordial radionuclides present in the earth's crust, such as 40K and radionuclides from 238U and 232Th series. These radionuclides are the main contributors to external gamma exposure indoors, especially when they are located in areas with different levels of radiation. In this context, this study aimed to determine the external effective dose rates inside houses (indoor dose), located near the uranium mine in the city of São José de Espinharas in the state of Paraiba, Northeast region, Brazil, that contain high levels of terrestrial radionuclides, which are the Naturally. Occurring Radioactive Material (NORM). To characterize the radiometric study, were installed 178 sets of thermoluminescent dosimeters, with three TLDs type LiF: Mg, Ti (lithium fluoride doped with Magnesium and Titanium) each, in the rooms of the residences, these being replaced on average, every 90 days, from December 2012 to November 2014. Environmental effective doses rates calculated for São José de Espinharas varied from 0.71 to 2.07 mSv.y-1 with an average of 0.90 mSv.y-1. Municipalities adjacent to the study area were also monitored in the study, highlighting: São Mamede, São José do Sabugi, Patos and Santa Luzia with interval values and averages of 0.77 to 1.41 mSv.y-1 (0, 94 mSv.y-1); 0.90 to 1.67 mSv.y-1 (1.13 mSv.y-1); 0.77 to 0.93 mSv.y-1 (0.87 mSv.y-1) and 1.10 to 1.27 mSv.y-1 (1.18 mSv.y-1), respectively. The overall average of the study was around 0.99 ± 0.10 mSv.y-1, corresponding to an average of 2.5 times higher than the estimated for indoors according to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), which is 0.41 mSv.y-1, giving the municipalities, exclusive influences of radioactive materials of natural occurrences, due to the geological formation of the region, when taken into consideration the levels of these radionuclides. It is observed that the results of this radioecological monitoring, does not allow to propose any "indoor" contamination condition without first monitor water, food, building materials, as well as the residents to predict any real risk factor for the population of these municipalities.
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Mirzadeh, Kousha. "TLD Measurements on Patients being treated with a Taylor Spatial Frame : Using Radiation from Na18F PET/CT Studies and from Naturally Occurring Radioisotopes." Thesis, Stockholms universitet, Fysikum, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-109361.
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Background: In an ongoing study conducted at Karolinska Institutet & Karolinska University Hospital, Positron Emission Tomography (PET)/Computed Tomography (CT) scans are performed on patients with tibia fractures and deformations treated with Taylor Spatial Frames (TSFs) in order to monitor their bone remodeling progress. Each patients receive an administration of approximately 2 MBq/kg bodyweight of Na18F associated with PET scans on two sessions, six and twelve weeks after the attachment of the TSF. These PET/CT scans provide information about the progress of the healing bone and can be used to estimate the optimal time point for de-attachment of the TSF. The Standardized Uptake Value (SUV) is used as a measure of the rate of bone remodeling for these patients, however, there is a need for verification of this practice by a method independent of the PET scanner. Furthermore, information regarding the biodistribution of the Na18F throughout the body of these patients and the effects of the TSF on the CT scan X‑rays is required. Additionally, an investigation of alternative methods that have the potential to provide similar information with a lower absorbed dose to the patients is desirable. Materials and methods: Thermoluminescent Dosimeters (TLDs) were attached on the skin at the position of the heart, urinary bladder, femurs, fracture, and the contralateral tibia of twelve patients during the first one hour and five minutes after the administration of the Na18F. Additional TLD measurements were performed during the CT scan of two of these patients. From the PET scan images, SUVs at the fracture site of these patients were collected. An investigation of the possibility of exploiting the “naturally” occurring bone seeking radionuclide Strontium-90 (90Sr) in the human body to gain information about the fracture site was undertaken. Using a 90Sr source, three different detection techniques were evaluated and a practical methodology for in vivo measurements on the tibia fracture patients was developed. As it was concluded that TLD based measurements were the most suitable technique for this purpose, and it was tested on five patients with tibia fractures. Results: From the collected TLD data, it was concluded that for these patients the urinary bladder is the organ receiving the greatest amount of absorbed dose and the organ most affected as the administered activity exceeds 2 MBq/kg. On average, a three times higher surface dose was measured on the tibia fracture compared to the un-fractured tibia. A linear relationship between the surface dose and SUVmax was shown. A strong positive correlation between the activity concentration at the fracture site and the amount of injected activity was found, and it was demonstrated that this also affects the SUVs. For patients who were administered different amounts of Na18F for the two PET scans, maximum activity concentrationwas less affected than mean activity concentration. It was concluded that TSF’s effect on the scatter of the X-rays to organs higher up in the body is negligible. Regarding “naturally” occurring 90Sr in the human body, no higher activity at the fractured tibia compared to the non‑fractured tibia could be found. Conclusions: This project assessed the accumulation of Na18F in the fracture site of patients treated with TSF by a method independent of the PET scanner. The methodology of using SUVs as an indicator for bone remodeling was verified. It was shown that the uptake of Na18F by the fracture site is strongly correlated to the amount of injected activity. The importance of considering the amount of injected activity when evaluating and comparing SUVs was highlighted. In vivo measurements using LiF:Mn TLDs did not indicate any quantifiable higher concentration of 90Sr at the fracture in the tibia bone.
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Howie, Andrew Gordon, and howie andrew@gmail com. "Improving high dose rate and pulsed dose rate prostate brachytherapy - alternative prostate definition and treatment delivery verification methods." RMIT University. Applied Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20091007.091553.
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Brachytherapy is a form of radiotherapy in which radioactive sources are placed at short distances from, or even inside the target volume. The use of high dose rate brachytherapy is a widely accepted and clinically proven treatment for some stages of prostate cancer. The aim of this project was to investigate potential improvements on two of the most important aspects of high dose rate (HDR) and pulsed dose rate (PDR) prostate brachytherapy - prostate definition and treatment delivery verification. The use of magnetic resonance (MR) imaging in addition to the conventional computed tomography (CT) imaging methods currently used routinely for brachytherapy planning may provide some benefit in accurately defining the prostate and surrounding critical structures. The methods used in this project involved analysis of data sets provided by two Radiation Oncologists. The results presented showed inter-observer and intra-observer variations in the size and shape of the prostate, as well as analysis of the dosimetric differences that may be reported due to the differences in prostate size and shape. The results also included analysis of critical structure dosimetry - dose to the surrounding radio-sensitive rectum and urethra. In summary, the results showed that the prostate was defined to be smaller using MR imaging than CT, however the consistency between Oncologists was not significantly improved using MR imaging. MR imaging may be useful in reducing the dose to normal tissue surrounding the prostate and in obtaining better coverage of the smaller target volume, without compromising the critical structures. The use of LiF:Mg,Ti thermoluminescent dosimeters (TLDs) is a potential avenue for in vivo dose verification of an HDR or PDR prostate brachytherapy treatment plan. This project included a phantom study of these TLDs with the aim to determine their feasibility for clinical use. Cylindrical TLD rods (6 mm length x 1 mm diameter) were used, as these fit inside the brachytherapy needles implanted into the prostate, and therefore had potential to be used clinically to verify the dose delivered in the prostate. This study was extended to include determination of a correction factor to allow an independent radiation source (6 MV photon beam from a linear accelerator) to be used to obtain control readings for this relative dosimetric method. The results showed these TLDs to be a promising in vivo dosimeter for prostate brachytherapy with potential errors in the order of 4%. Their potential lies in the fact that they could detect and flag significant calculation errors in treatment plans, and they utilise equipment used routinely for external beam radiotherapy dosimetry in many treatment facilities, reducing the cost of implementing such a procedure.
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Tamras, Dina. "Verification of dose limitation of the general public and determination of lead equivalence of x-ray rooms at Karolinska University Hospital Huddinge." Thesis, Stockholm University, Medical Radiation Physics (together with KI), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7215.
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A variety of radiation sources exist at the Department of Radiology and the Department of Nuclear Medicine at Karolinska University Hospital Huddinge. Radiation sources can also be found in areas outside of these departments due to the wide use of mobile xray machines and fluoroscopic c-arm equipment and also due to the movement of patients that have received diagnostic or therapeutic doses of radionuclides.
In a proposal for a new legislation from the Swedish Radiation Protection Authority (SSI), which was later issued as legislation SSI FS 2005:6, the effective doses of the general public from a practice using ionising radiation need to be kept below stated limit of 0.1 mSv/year. This project was performed to verify the dose limit for individuals of the general public in the above mentioned practices.
Long-term measurements with TL-dosimeters were utilised to carry out the environmental monitoring of the areas throughout the Departments of Radiology and Nuclear Medicine. To assess the contribution of ionising radiation from rooms housing mobile fluoroscopic c-arm equipment to surrounding areas, a tissue equivalent phantom of size (30×30×20 cm3) was employed to simulate a patient and the scattered radiation was monitored by using area monitors, such as portable proportional counters. The annual effective doses were calculated in terms of personal dose equivalent as well as ambient dose equivalent monitored using TL-dosimeters and area monitors, respectively. The stated limit of 0.1 mSv/year to the general public was verified by risk analysis.
An attempt to create a method for determining the amount of radiation shielding in terms of lead equivalence in walls, doors, protective glasses of manoeuvre rooms and cupboards of diagnostic x-ray labs was also performed using a radiation point source of 99mTc and a NaI scintillation detector. Depending on the accuracy in the measurements the amount of lead deviated slightly from the expected 2 mm value based on the former legislation SSI FS 1991:1.
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Ordóñez, Ródenas José. "Desarrollo de Modelos de Simulación por Monte Carlo como Apoyo a la Medida de Radiactividad Ambiental en Operación Rutinaria y de Emergencias." Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/152188.
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[ES] En el apoyo a la mejora de la calidad de medida en el Laboratorio de Radiactividad Ambiental (LRA) de la Universitat Politècnica de València (UPV), los códigos de Monte Carlo representan una potente herramienta para complementar las tareas relacionadas con la medida de la radiactividad ambiental, tales como la calibración en eficiencia de detectores de semiconductor, determinación de factores de corrección por coincidencia y caracterización de dosímetros de termoluminiscencia, entre otras.
En la presente Tesis se desarrollan modelos de simulación en Monte Carlo a través de códigos y herramientas como MCNP6 y GEANT4. En primer lugar, se han realizado dos modelos de detector de semiconductor para espectrometría gamma, uno tipo HPGe (High Purity Germanium) y el otro BEGe (Broad Energy Germanium), ambos de alta pureza de germanio. Ambos detectores se emplean en las actividades y procedimientos rutinarios que se realizan en el LRA-UPV. Se detalla el procedimiento de caracterización geométrica de los detectores de semiconductor, así como del volumen activo del cristal de germanio hasta obtener un modelo geométrico optimizado.
Por otro lado, se ha obtenido un tercer modelo de simulación, pero en este caso de un dosímetro de termoluminiscencia, en concreto de un TLD-100 LiF:Mg,Ti, modelo que se emplea en el servicio de dosimetría personal de la UPV. En el modelo de simulación se incluye una fuente puntual colimada de Rayos-X y el fantoma recomendado por la ISO 4037-3 (water slab phantom). Se obtiene la función de respuesta del dosímetro relativa a la energía del 137Cs y se estudia su comportamiento para diferentes condiciones de irradiación (calidad del haz de Rayos-X y ángulo de incidencia) así como para diversos materiales termoluminiscentes además del LiF.
Los modelos de simulación para espectrometría gamma se han utilizado principalmente para la obtención de curvas de calibración en eficiencia para diferentes geometrías y matrices de medición, así como para el cálculo de factores de corrección por pico suma tanto para las series naturales del 238U y 232Th como para radioisótopos específicos empleados en la calibración experimental de los equipos.
Por otro lado, se han aplicado los modelos de simulación en el contexto de respuesta en emergencias nucleares o radiológicas. En concreto, el modelo del detector BEGe se ha utilizado para desarrollar una metodología de optimización del proceso de medición de muestras radiactivas en matrices de agua de alta actividad. Esta metodología consiste en un procedimiento logístico que incluye un cribado o screening de emergencias soportado por simulaciones Monte Carlo, enfocado en elegir la configuración óptima de medición para obtener resultados fiables y precisos minimizando la manipulación de la muestra radiactiva. De este modo se reduce el tiempo de respuesta por parte del laboratorio, así como el riesgo de contaminación y exposición a dosis.[EN] In support of the improvement of measurement quality at the Laboratorio de Radiactividad Ambiental (LRA) of the Universitat Politècnica de València (UPV), the Monte Carlo codes represent a powerful tool to complement the tasks related to the measurement of environmental radioactivity, such as the calibration in efficiency of semiconductor detectors, determination of coincidence summing correction factors and characterization of thermoluminescence dosimeters, among others. In the present thesis, Monte Carlo simulation models are developed using the MCNP6 code and the GEANT4 toolkit. Two semiconductor detector models for gamma spectrometry have been made, one type HPGe (High Purity Germanium) and the other one a BEGe (Broad Energy Germanium), both of high purity germanium. Both detectors are used in the routine activities and procedures carried out by the LRA-UPV. The geometric characterization procedure of the semiconductor detectors is detailed, as well as the active volume of the germanium crystal until an optimized geometric model is obtained. On the other hand, a third simulation model has been developed, but in this case from a thermoluminescence dosimeter, specifically from a TLD-100 LiF:Mg,Ti, a model used in the personal dosimetry service for the monitoring and assessment of the professionally exposed workers belonging to the UPV radioactive facility. The simulation model includes a collimated X-ray point source and the phantom recommended by the ISO 4037-3 (water slab phantom). The response function of the dosimeter relative to the energy of 137Cs is obtained and its behaviour is studied for different irradiation conditions (quality of the X-ray beam and angle of incidence) as well as for several thermoluminescent materials in addition to the LiF. The simulation models for gamma spectrometry have been used mainly to obtain efficiency calibration curves for different geometries and measurement matrices and to calculate true summing correction factors for both the 238U and 232Th natural decay series and for specific radioisotopes used in the experimental calibration of the equipment. On the other hand, simulation models have been applied in the context of nuclear or radiological emergency response. Specifically, the BEGe detector model has been used to develop a methodology for optimisation of the process of measuring radioactive samples in water matrices of high activity. This methodology consists of a logistic procedure that includes a screening for emergencies. This procedure is supported by Monte Carlo simulations, focused on determining the optimal measurement configuration to obtain reliable and accurate results, minimizing the manipulation of the radioactive sample. Therefore, the response time by the laboratory is reduced, as well as the risk of contamination and dose exposure.
[CA] En el suport a la millora de la qualitat de mesura en el Laboratori de Radioactivitat Ambiental de la Universitat Politècnica de València, els codis de Monte Carlo representen una potent eina per a complementar les tasques relacionades amb la mesura de la radioactivitat ambiental, com ara el calibratge en eficiència de detectors de semiconductor, determinació de factors de correcció per coincidència i caracterització de dosímetres de termoluminescència, entre altres. En la present tesi es desenvolupen models de simulació en Monte Carlo a través de codis i eines com MCNP6 i GEANT4. En primer lloc s'han realitzat dos models de detector de semiconductor per a espectrometria gamma, un tipus HPGe (High Purity Germanium) i l'altre BEGe (Broad Energy Germanium), tots dos d'alta puresa de germani. Aquests detectors s'empren en les activitats i procediments rutinaris que es realitzen en el Laboratori de Radioactivitat Ambiental (LRA) de la Universitat Politècnica de València (UPV). Es detalla el procediment de caracterització geomètrica dels detectors de semiconductor, així com del volum actiu del cristall de germani fins a obtindre un model geomètric optimitzat. D'altra banda, s'ha obtingut un tercer model de simulació, però en aquest cas d'un dosímetre de termoluminescència, en concret d'un TLD-100 LiF:Mg,Ti, model que s'empra en el servei de dosimetria personal de la UPV. En el model de simulació s'inclou una font puntual col·limada de Raigs-X i el fantoma recomanat per l'ISO 4037-3 (water slab phantom). S'obté la funció de resposta del dosímetre relativa a l'energia del 137Cs i s'estudia el seu comportament per a diferents condicions d'irradiació (qualitat del feix de Raigs-X i angle d'incidència) així com per a diversos materials termoluminescents a més del LiF. Els models de simulació per a espectrometria gamma s'han utilitzat principalment per a l'obtenció de corbes de calibratge en eficiència per a diferents geometries i matrius de mesurament així com per al càlcul de factors de correcció per pic suma tant per a les sèries naturals del 238U i 232*Th com per a radioisòtops específics utilitzats en el calibratge experimental dels equips. D'altra banda, s'han aplicat els models de simulació en el context de resposta en emergències nuclears o radiològiques. En concret, el model del detector BEGe s'ha utilitzat per a desenvolupar una metodologia d'optimització del procés de mesurament de mostres ambientals radioactives en matrius d'aigua d'alta activitat.. Aquesta metodologia consisteix en un procediment logístic que inclou un screening o cribratge d'emergències, suportat per simulacions Monte Carlo, enfocat a triar la configuració òptima de mesurament per a obtindre resultats fiables i precisos minimitzant la manipulació de la mostra radioactiva. D'aquesta manera es redueix el temps de resposta per part del laboratori, així com el risc de contaminació i exposició a dosi.
Finalmente, a la Universitat Politècnica de València por la financiación a través de la beca de Formación de Personal Investigador (FPI)-Subprograma 2 de la convocatoria de 2015 y a la Cátedra CSN-UPV Vicente Serradell
Ordóñez Ródenas, J. (2020). Desarrollo de Modelos de Simulación por Monte Carlo como Apoyo a la Medida de Radiactividad Ambiental en Operación Rutinaria y de Emergencias [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/152188
TESIS
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Weatherford, Lenora B. P. "A qualitative examination of the administrative process of fleet enlisted personnel in various medical categories." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FWeatherford.pdf.
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Thesis (M.S. in Management)--Naval Postgraduate School, March 2003.Thesis advisor(s): Stephen L. Mehay, William D. Hatch II. Includes bibliographical references (p. 115-118). Also available online.
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Mendoza, Raul Ernesto Camargo. "Determinação de grandezas dosimétricas de interesse em mamografia usando detectores termoluminescentes." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-17042010-115247/.
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Os órgãos de saúde internacionais e nacionais, como o Ministério da Saúde na portaria 453/98 da Vigilância Sanitária, exigem que a Dose de Entrada na Pele seja avaliada para cada equipamento mamográfico através da leitura de um sistema câmara de ionização-eletrómetro corrigida pelo fator de retroespalhamento. Ao não existir menção explícita na portaría de valores utilizáveis para o fator de retroespalhamento, este trabalho visa à determinação experimental do fator de retroespalhamento, através da utilização dos dosímetros termoluminescentes TLD-100. No estudo são verificadas as dependências geométricas e espectrais do fator de retroespalhamento, assim como do valor da Dose de Entrada na Pele, e da Dose em Profundidade, correspondentes com as técnicas radiográficas empregadas nos exames mamográficos convencionais de rotina. Foram avaliados feixes na faixa de 0,35 mmAl até 0,43 mmAl, tensões do tubo de 25kV, 28kV, 30kV, e 32kV, assim como os três tamanhos de campo disponíveis no Mamógrafo Senographe DMR utilizado, e distancias focofilme iguais a 56cm, 61cm e 66cm. Os resultados obtidos foram comparados com publicações existentes, as quais apresentam resultados obtidos através de Simulação Monte Carlo, câmaras de ionização, e dosímetros TLD-100. Os resultados obtidos neste trabalho permitem estabelecer e discutir as dependências das grandezas dosimétricas estudadas com a Camada Semi-Redutora, tensão do tubo, combinação ânodo-filtro, tamanho de campo, distância foco-filme e espessura da mama.National and international health organizations such as the Brazilian Ministry of Health, through its Secretary of Health Surveillance establishes in the publication Nº 453/98 that in all mammographic equipments must be evaluated the entrance-skin dose through the readings of an ionization chamber-electrometer system corrected by the backscatter factor, among others factors. Nevertheless, there is no explicit mention for useful values of backscatter factor in this document; the main aim of this work is the experimental determination of backscatter factor through the use of TLD-100 dosimeters. In this study, the geometric and spectral dependencies of the backscatter factor, entrance-skin dose and the in-depth dose were evaluated, corresponding to the most radiographic techniques employed in conventional mammographic procedures, i.e., beam qualities in the range of 0.35 mmAl to 0.43 mmAl, tube voltages from 25kV to 32kV, focus-film distances from 56cm to 66cm, and three field sizes were evaluated. Our results were compared with those previously published obtained through Monte Carlo simulation, ionization chambers and TLD dosimeters. The results obtained in this work allow studying the dependency of the mentioned dosimetric quantities with the half-value layer, tube voltage, anode-filter combination, field size, focusfilm distance and breasting thickness of the breast.
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Stigson, Magnus. "Object Tracking Using Tracking-Learning-Detection inThermal Infrared Video." Thesis, Linköpings universitet, Datorseende, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93936.
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Automatic tracking of an object of interest in a video sequence is a task that has been much researched. Difficulties include varying scale of the object, rotation and object appearance changing over time, thus leading to tracking failures. Different tracking methods, such as short-term tracking often fail if the object steps out of the camera’s field of view, or changes shape rapidly. Also, small inaccuracies in the tracking method can accumulate over time, which can lead to tracking drift. Long-term tracking is also problematic, partly due to updating and degradation of the object model, leading to incorrectly classified and tracked objects. This master’s thesis implements a long-term tracking framework called Tracking-Learning-Detection which can learn and adapt, using so called P/N-learning, to changing object appearance over time, thus making it more robust to tracking failures. The framework consists of three parts; a tracking module which follows the object from frame to frame, a learning module that learns new appearances of the object, and a detection module which can detect learned appearances of the object and correct the tracking module if necessary. This tracking framework is evaluated on thermal infrared videos and the results are compared to the results obtained from videos captured within the visible spectrum. Several important differences between visual and thermal infrared tracking are presented, and the effect these have on the tracking performance is evaluated. In conclusion, the results are analyzed to evaluate which differences matter the most and how they affect tracking, and a number of different ways to improve the tracking are proposed.
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Sung, Ho-Joon. "Optimal maintenance of a multi-unit system under dependencies." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26511.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.Committee Chair: Schrage, Daniel; Committee Member: Loewy, Robert; Committee Member: O'Neill, Gary; Committee Member: Saleh, Joseph; Committee Member: Volovoi, Vitali. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Karlsson, Hanna. "Styrd tid är stulen tid, kontrollerad tid är fri tid : Om fyra kvinnors syn på tid och hur den används." Thesis, Linköpings universitet, Institutionen för kultur och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97712.
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Syftet med denna uppsats är att studera fyra kvinnors syn på tid, struktur och kreativitet på servicedesignbyrån Transformator design. Genom intervjuer och deltagande observation undersöker jag hur tid, struktur och kreativitet samspelar för mina informanter, och hur de använder tiden. Slutsatsen av denna studie är i korthet att kontrollen av tid är viktig för upplevelsen av tid. Strukturer, synliga och osynliga, är centrala för att se och förstå tiden och upprätthålla kontrollen av tid. Informanternas strävan är att skapa fylld tid, som är värdefull tid, och genom kontroll av tiden skapa en positiv känsla av att ha tid. Det är då kreativiteten släpps fri.The purpose of this thesis is to study four women's view of time, structure and creativity at the service design agency Transformer design. Through interviews and participant observation, I examine how time, structure and creativity interact for them, and how they use time. The conclusion of this study is in brief that the control of time is important to the experience of time. Structure, visible and invisible, is central to see and understand time and maintain control of the time. The informant's aim to create filled time, which is valuable time, and by controlling time they create a positive sense of having time. That's when creativity is released.
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Blanchet, David. "Développements méthodologiques et qualification de schémas de calcul pour la modélisation des échauffements photoniques dans les dispositifs expérimentaux du futur réacteur d'irradiation technologique Jules Horowitz (RJH)." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00689995.
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L'objectif de cette thèse est de développer la modélisation des échauffements nucléaires au niveau des dispositifs expérimentaux du futur réacteur d'irradiation technologique Jules Horowitz (RJH). La forte puissance nucléaire spécifique produite (460 kW/l) induit des flux photoniques intenses qui provoquent des échauffements et des gradiants de température importants, qu'il est nécessaire de maîtriser dès la conception. Or, les calculs d'échauffement sont pénalisés par des incertitudes rédhibitoires estimées à une valeur enveloppe et majorante de 30% (2 sigma) provenant des lacunes et incertitudes des données d'émission gamma présentes dans les bibliothèques de données nucléaires de base. Le programme expérimental ADAPh vise à réduire ces incertitudes. Des mesures par détecteurs thermoluminescents (TLD) et par chambres d'ionisation sont réalisées dans les maquettes critiques EOLE (MOX) et MINERVE (UO2). L'interprétation rigoureuse de ces mesures nécessite des développements spécifiques basés sur des simulations Monte-Carlo de transport couplé neutron-gamma et gamma-électron. Les développements effectués se singularisent notamment par la modélisation de phénomènes de cavités et d'émissions gamma retardés par décroissance des produits de fission. Les comparaisons calcul-mesure ont permis d'identifier un biais systématique C/E=0.72 confirmant une tendance des calculs à sous-estimer la mesure. Une méthode d'ajustement Bayésienne a été développée afin de ré-estimer les principales composantes de l'échauffement gamma et de transposer les résultats obtenus aux dispositifs du RJH dans des conditions de représentativité clairement définies. Cette thèse a permis de réduire significativement les incertitudes sur la détermination des échauffements gamma de 30% à 15% (2 sigma)
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Szantho, von Radnoth Julia. "Vom Bewusstsein des Todes und dem Umgang damit : Betrachtung anhand einiger Phänomenologen des 20. Jahrhunderts /." Marburg : Tectum-Verl, 2009. http://d-nb.info/992328985/04.
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Pedrosa, Angelina Gonçalves. "Valor prognóstico de características clinicopatológicas e imunofenotípicas em tumores mamários caninos." Master's thesis, Universidade de Lisboa. Faculdade de Medicina Veterinária, 2016. http://hdl.handle.net/10400.5/11516.
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Dissertação de Mestrado Integrado em Medicina VeterináriaÀ semelhança do que é a realidade no universo da Medicina humana, a identificação de parâmetros relevantes a nível de prognóstico constitui uma área de investimento considerável na investigação do cancro mamário canino. Este trabalho pretende caracterizar tumores mamários caninos quanto às características epidemiológicas, clinicopatológicas e imunofenotípicas, avaliando o seu valor prognóstico pela investigação de associações significativas ou tendenciais entre si e incluindo as que dizem respeito aos estudos de sobrevivência [análise do tempo de sobrevivência (TS) e do tempo livre de doença (TLD)]. Pretende verificar também, em termos temporais concretos, como as diferenças em cada uma das características se traduz em termos de prognóstico. Os dados foram obtidos a partir de uma amostra de 41 cadelas que apresentavam tumores mamários. Os tumores foram analisados por avaliação histopatológica, pela avaliação da expressão de marcadores moleculares (Ki-67, RP, HER-2 e CK5/6) através de técnica imunohistoquímica e pelo estabelecimento de sua respetiva classificação molecular. Em termos epidemiológicos a nossa amostra mostrou-se perfeitamente concordante com a descrita em estudos anteriores. Em termos associativos foi possível concluir, a nível estatisticamente significativo, do pior prognóstico do maior tamanho tumoral, da metastização regional, do maior estadio tumoral TNM, da infiltração de células linfocíticas, dos tipos histopatológicos considerados de maior malignidade, do maior grau histológico de malignidade e da ausência de diferenciação mesenquimatosa. A expressão de Ki-67 como indicador de proliferação revelou-se de valor prognóstico importante, pela associação (estatisticamente significativa) da sua maior expressão às características anteriormente descritas como indicativas de pior prognóstico em si: o tamanho tumoral, o grau de malignidade, a necrose intratumoral, a metastização regional e, em termos epidemiológicos, a cadelas de raça indeterminada. O valor cut-off de 25% para o Ki-67 surgiu como o mais apropriado para o estudo do seu valor prognóstico (quando comparado com os cut-off alternativos de 20% e 16,43%-mediana) pelo número e significância de associações conseguidas. A maior expressão de RP surgiu associada significativamente aos tumores de cadelas inteiras e cadelas de raça indeterminada, assim como a tumores de tipo histológico simples e complexos e graus I e II de malignidade. Verificou-se uma sobre-expressão do marcador HER-2 em 19,4% dos tumores analisados, com uma maior frequência destes em carcinomas simples e de grau histológico III com infiltração linfocítica, não se chegando no entanto a associações estatisticamente significativas As CK5/6 tiveram expressão positiva quase ubiquitária, sendo os carcinomas de células escamosas o tipo histológico com uma maior percentagem de marcação. Dentro das associações estatisticamente significativas, no que diz respeito aos subtipos moleculares de acordo com o sistema de classificação adotado, os tipos Luminal A e B foram associados às cadelas de raça indeterminada, verificando-se uma maior significância quando considerado apenas o subtipo Luminal B. Este subtipo foi também associado à ocorrência de metastização. O subtipo Basal foi associado (quase significativamente) às cadelas previamente submetidas a OVH e, significativamente, a carcinomas de células escamosas. Os estudos de sobrevivência vieram, por análise dos diferenciais de tempo dos TS e TLD, corroborar as indicações fornecidas pelas associações. A nível significativo apenas o tamanho tumoral se revelou como indubitável fator de prognóstico para TS e TLD, e apenas considerando o cut-off de 3 cm. A nível quase significativo, foram validados como fatores de prognóstico de TS a classificação histopatológica (carcinomas simples/complexos), a infiltração linfóide, a metastização regional, o estadiamento TNM (I+II/III+IV) e o Ki-67 (cut-off de 25%) e como fatores de prognóstico do TLD a infiltração celular linfóide e a OVH simultânea à mastectomia. Quanto aos subtipos moleculares, o subtipo molecular HER-2 positivo apresentou sempre o pior prognóstico, sendo bastante aproximado do subtipo Basal, sendo os melhores prognósticos apresentados pelos subtipos moleculares Luminais. Os subtipos Luminais A e B apresentaram TS e TLD muito aproximados. Não se verificou conservação de características imunofenotípicas e, consequentemente, de subtipo molecular, dos tumores considerados primários para as suas metástases. Dadas as dificuldades encontradas na elaboração deste trabalho concluiu-se ser essencial a criação de guidelines mais detalhadas concernentes a todos os processos envolvidos no estudo da patologia desta afeção na espécie canina em particular.
PROGNOSTIC VALUE OF CLINICOPATHOLOGIC AND IMMUNOPHENOTYPIC FEATURES IN CANINE MAMMARY TUMOURS - As in human medicine, the identification of relevant prognostic parameters constitutes a vast area of considerable investment in the canine mammary cancer study. This work intends the characterization of canine mammary tumors concerning the epidemiological, clinicopatologic and imunophenotipic characteristics, evaluating their prognostic value by the investigation of significative associations and tendencies between them and including the ones that concern the survival studies [overall survival (OS) and disease free survival (DFS)]. Furthermore, it aims to verify, in concrete temporal terms, how the differences in each characteristic translate in prognostic terms. The data were gathered from a sample of 41 bitches presenting mammary tomours. The tumors were analysed by histopathologic evaluation, the immunohistochemical expression of molecular markers (Ki-67, RP, HER-2 e CK5/6) and according to the respective molecular classification. Epidemiologically, our sample has proved to be perfectly accordant with previous studies. Considering the correlation studies, we were able to conclude, in a significant level, of the worse prognosis of the larger tumor size, the regional metastasis, the higher TNM stage, the lymphocitic infiltration, the histologic tumor types considered of higher malignancy, the higher histologic grade and the absence of mesenchimal differentiation. Ki-67 as the proliferation indicator has revealed itself of important prognostic marker, as its higher rate correlated (on a significant level) with the previously described characteristics of worse prognosis: tumour size, malignancy grade, intratumoral necrosis, regional metastasis and, epidemiologically, mixed breed bitches. The cut off value of 25% for Ki-67 stood up as the most appropriate to study its prognostic value (when compared with the 20% and 16,43% -median- alternative cut-offs) by the significance of associations. The biggest expression of PR was significantly associated to the tumors of biches of mixed breed and not sterilized, also as to simple and complex carcinomas and histological grades I and II. There was a HER-2 overexpression in 19,4% of the analysed tumors and there were several tendencies verified, such as a higher frequency in simple carcinomas, grade III carcinomas and lymphocitic infiltration, even though we couldn´t find any significant correlations. Citokeratins 5/6 had an almost ubiquitous expression, with squamous cells carcinomas being the ones with the highest percentage of marked cells. Considering the molecular subtypes, according to the adopted classification system, the Luminal A and B were correlated with mixed breed biches, with an increase of the significance level when considered the Luminal B subtype alone. This subtype was also correlated with the occurrence of regional metastization. Basal subtype was correlated (almost significantly) with ovariectomized bitches and, significantly, to scamous cells carcinomas. Considering the survival studies, on a statistical significant level, only the tumour size was undoubtedly revealed as prognostic factor for OS and DFS, and only when considered the 3 cm cut-off. On a statistical significant level, histopathological classification (simple/complex carcinomas), lymphocitic infiltration, regional metastization, TNM staging (I+II/III+IV) and Ki-67 (25% cut-off) were validated as OS prognostic factors. As for DFS, only lymphocitic infiltration and OVH simultaneous to mastectomy were found. As regards for the molecular classification, the HER-2 overexpression subtype presented the worst prognosis, both in OS and DFS, being quite close to the Basal subtype. The best prognosis were presented by the Luminal subtypes which were, between them (Luminal A and B) very similar in OS and DFS. We didn’t observe any conservation of immunophenotypic traits or molecular subtypes from the primary tumour to its metastasis. Given the difficulties found in the elaboration of this work, we consider as essential the existence of more detailed guidelines concerning the processes involved in the study of the pathology of this disease in this particular species.
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Rüve, Gerlind. "Scheintod : zur kulturellen Bedeutung der Schwelle zwischen Leben und Tod um 1800 /." Bielefeld : Transcript, 2008. http://d-nb.info/98675658X/04.
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Allali, Nourredine. "Analyse du rôle des gènes chromosomiques tldD et tldE dans le système poison/antidote ccd et dans la maturation de la microcine B17." Doctoral thesis, Universite Libre de Bruxelles, 2002. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211343.
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Yaakob, Najmiddin. "Top of the Line Corrosion in CO2/H2S Environments." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1427716457.
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Olson, Ted. "Ted Olson's Poetry." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/1122.
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Ted Olson was the featured poet for the symposium who presented “Scotland the Brave: A Nation's Legacy in Literature and Folklore,” "When First Unto This Country: The Flow of Scottish and Scots-Irish Culture to the American South in Song and Story," "Darkness and Revelation: Ted Olson's Poetry".
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Klasila, A. (Aleksi). "TryTLS:testing TLS libraries." Bachelor's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201712203359.
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Encryption is a fundamental building block in protecting our privacy and safety of our society, unfortunately we may fail to use it properly. TLS (Transport Layer Security) has an important part in encrypting the connections on the Internet today. SSL (Socket Layer Security) is the deprecated and dangerous version of TLS. SSL should not be used anymore. There are many protocols developed that use TLS. For example: HTTPS (Hypertext Transfer Protocol Secure), FTPS (File Transfer Protocol with support for TLS) and IMAP (Internet Message Access Protocol). All the protocols using TLS have also got many different implementations in different programming languages and libraries. This thesis researches the tools used to test how different (client-) libraries implement TLS. This thesis also researches the known TLS/SSL vulnerabilities. In this thesis a backed for TLS testing purposes is implementedSalaus on perusrakenneosa yksityisyyden ja turvallisuuden suojaamisessa yhteiskunnassamme, valitettavasti saatamme suoriutua siinä huonosti. TLS:llä (Transport Layer Security) on nykyisin tärkeä osa Internet-liikenteen salaamisessa. SSL (Socket Layer Security) on TLS:n vanhentunut ja vaarallinen edeltäjä. SSL:ää ei pitäisi käyttää enään nykyisin. On olemassa monia protokollia, kuten HTTPS (Hypertext Transfer Protocol Secure), FTPS (File Transfer Protocol with support for TLS) ja IMAP (Internet Message Access Protocol), jotka käyttävät TLS:ää. Lisäksi, kaikilla TLS:ää käyttävillä protokollilla on useita toteutuksia eri ohjelmointikielillä ja kirjastoilla. Tässä työssä tutkitaan kehitettyjä työkaluja TLS-kirjastojen testaamiseen. Tässä työssä tutkitaan myös tunnettuja TLS/SSL-haavoittuvuuksia. Tässä työssä rakennetaan lisäksi järjestelmä TLS:n testaamista varten
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Polzer, Joachim. "Videodisk TED Bildplatte." Doctoral thesis, Akademie múzických umění v Praze. Filmová a televizní fakulta AMU. Knihovna, 2010. http://www.nusl.cz/ntk/nusl-97011.
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Larsson, Annette, and Natalie Nilsson. "Sjuksköterskans patientnära tid." Thesis, Malmö högskola, Fakulteten för hälsa och samhälle (HS), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-26502.
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Bakgrund: Kompetensbeskrivning för legitimerad sjuksköterska beskriver att det är sjuksköterskans ansvar att ge patienten en god och säker vård ur ett etiskt perspektiv samt genom beprövad erfarenhet. Patientnärmre vård är ett arbetssätt som sätter patienten och dennes problem och behov i centrum. Omvårdnadens kvalitet ökar och ger en snabbare rehabiliteringstid för patienten.Syfte: Att granska vad den patientnära tiden innebär för sjuksköterskan och se vad den innehåller. Hur mycket tid, totalt, läggs ner på patientnära tid under ett dagspass? Metod: Empirisk, strukturerad icke deltagande observationsstudie med kvantitativ och kvalitativ ansats. Det kvantitativa resultatet har bearbetats och presenteras i form av diagram och text. Det kvalitativa resultatet har analyserats med latent innehållsanalys.Resultat: Studien visade att den patientnära tiden var låg på den observerade avdelningen. Den uppmätta genomsnittliga patientnära tiden var 15, 5 % av ett dagspass mellan 7.00-13.00. Huvuddelen av den patientnära tiden ägnades åt omvårdnadsåtgärder. Slutsats: Resultatet visar att ett behov av förändring i sjuksköterskornas arbete och dess organisering är utmärkande.Background: The Competence Description for Swedish Certified Nurse describes the nurse's responsibility to give the patient a good and safe care from an ethical perspective and through proven experience. The patient focused work method is an approach that places the patient and his problems and needs in the centre. Nursing care quality increases and gives a quicker rehabilitation time for the patient. Objective: To examine what the direct patient time means to the nurse and see what it contains. How much time, total, spent on direct patient time in a day's work? Method: Empirical, structured non-participant observational study with quantitative and qualitative approach. The quantitative result have been processed and is presented in the form of diagrams and text. The qualitative results were analyzed with latent content analysis. Results: The study showed that the direct patient time was low at the observed ward. The measured average direct patient time was 15,5 % of a day between 7.00-13.00. Most of the direct patient time was devoted for care measures.Conclusion: The result shows that a need for change in the nurses work and its organization is eminent.
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Westlund, Ingrid. "Skolbarn av sin tid : En studie av skolbarns upplevelse av tid." Doctoral thesis, Linköping : Univ, 1996. http://WWW.Bibl.Liu.Se/liupubl/disp/disp96/ipp49s.htm.
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Rydberg, Christina. "En annan tid : Definitioner av tid i franska uppslagsverk, 1690-1835." Thesis, Stockholms universitet, Institutionen för kultur och estetik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-169814.
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Another time. Definitions of time in French encyclopedias, 1690-1835 The point of departure for this study is the common conception that the idea of time became "modern" in the late 18th century, meaning among other things a new, future-oriented and empowered individual. Such a view has been expressed by scholars like Lynn Hunt, Lucian Hölscher, François Hartog, Dan Edelstein as well as Reinhart Koselleck. This thesis investigates whether such a transformation is visible in eight French encyclopedias, published between 1690 and 1835. Definitions of time-related key-words are studied from a perspective of conceptual history and discourse analysis. The result of the study indicates a change in the notion of time. However, this change does not concur with the presumed breakthrough of "modernity". The dominant change is rather words that disappear during the period. The study argues that the dichotomy of time versus eternity was questioned, which changed the expectations. Definitions eventually turned away from a predetermined future, however they did not include an individual freedom to act. A new temporal consciousness is visible with the update of history, as pointed out by Koselleck. Mythology was mocked when definitions underlined rationality. The texts substituted religion with science. Diversity between individual definitions is visible mostly during the middle of the 18th century. Finally, the study discusses a possible time lag for encyclopedias used as witnesses of a discourse.Autres temps. Les définitions du temps des encyclopédies françaises, 1690-1835 La notion de temps au sens moderne semble avoir pris forme vers la fin du 18e siècle. Cette conception du temps comme « moderne » implique entre autres choses que l'homme est conscient de la dimension temporelle, et de sa liberté de créer son propre avenir. Depuis les années 1960, plusieurs penseurs, dont François Hartog, Lynn Hunt, Lucian Hölscher, Dan Edelstein et Reinhart Koselleck, ont abordé ce décalage de la dite notion. Dans cette thèse sont examinés les changements de la notion du temps à travers les définitions de huit encyclopédies publiées entre 1690 et 1835. Au 18e siècle, les dictionnaires et les encyclopédies jouaient un rôle important quant au savoir et à la maitrise de la langue. Les analyses des définitions sont conduites à la lumière des théories conceptuelles et discursives. Les résultats de l'étude, dont le matériau s'étend sur 150 ans, confirment un changement de la notion de temps mais non pas celui dont a parlé la recherche antérieure. Les définitions témoignent d'un certain nombre d'effacements et de substitutions de différentes parties des textes. Les textes semblent avoir été plus homogènes au début et à la fin du 18e siècle et plus hétérogènes au milieu du même siècle. Les références religieuses s'y sont souvent substituées à des textes provenant des sciences naturelles, comme par exemple la mécanique. Successivement, les explications mythologiques étaient qualifiées de purs « mythes ». La dichotomie temps—éternité est remise en question et commence à disparaître. Selon d'autres chercheurs dans ce domaine, cela signifie une des conditions d'un futur non prédéterminé. Cependant, même au début du 19e siècle, les définitions parlent d'un futur contingent et non d'un homme maître de son propre futur. Pendant cette période (1690-1835), il y a aussi eu lieu un changement dans la façon de concevoir la notion d' «histoire », un phénomène qui a été souligné par Koselleck. Ce changement semble avoir entrainé une nouvelle conceptualisation de la temporalité. Dans la thèse sont discutées les encyclopédies comme étant des sources scientifiques et la possibilité d'un « time lag » dû aux définitions comparées au discours où celles-ci sont produites. Les résultats montrent l'introduction apparemment tardive d'un nouveau discours.
Masterprogram i historiska studier, inriktning idéhistoria
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Perez, Francisca. "Engelska förkunskaper över tid -Elevers förändring i engelska förkunskaper över tid." Thesis, Örebro universitet, Institutionen för humaniora, utbildnings- och samhällsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-67738.
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The English language is becoming more common in our society. Research shows that students learn English in their spare time as well as in the classroom. The purpose of the study is to investigate teachers’ experiences of students’ previous knowledge in English, if it has changed over time in speech and vocabulary and what sources the teachers perceive that the students meet in their spare time. I considered it appropriate to use qualitative data collection in the form of semi structured interviews with experienced teachers. The result shows that the teachers in my study can see a change in previous knowledge over time and that the sources are often connected to the internet. I found that both the previous research and the results of my data in this study agree that extramural English is rewarding for students’ English knowledge. There has been a big change in an increased level of previous knowledge in English. An important conclusion is that this increase of previous knowledge contributes to greater variation of knowledge among students, which puts higher demands on teachers to individualize the teaching.