It is my hope that this thesis may serve as a guide for future students wishing to build a microscope from scratch. The design and construction of a scanning, confocal fluorescence microscope equipped with shaped microwave excitation is detailed. The use of the microscope is demonstrated by coherently manipulating single Nitrogen-Vacancy centres in diamond. Further the instrument is used to investigate a dual Halbach array magnet system.

This dissertation focuses on the global investigation of optically thin cirrus cloud optical thickness (tau) and microphysical properties, such as, effective particle size (D_(eff)) and ice crystal habits (shapes), based on the global satellite observations and fast radiative transfer models (RTMs). In the first part, we develop two computationally efficient RTMs simulating satellite observations under cloudy-sky conditions in the visible/shortwave infrared (VIS/SWIR) and thermal inferred (IR) spectral regions, respectively. To mitigate the computational burden associated with absorption, thermal emission and multiple scattering, we generate pre-computed lookup tables (LUTs) using two rigorous models, i.e., the line-by-line radiative transfer model (LBLRTM) and the discrete ordinates radiative transfer model (DISORT). The second part introduces two methods (i.e., VIS/SWIR- and IR-based methods) to retrieve tau and D_(eff) from satellite observations in corresponding spectral regions of the two RTMs. We discuss the advantages and weakness of the two methods by estimating the impacts from different error sources on the retrievals through sensitivity studies. Finally, we develop a new method to infer the scattering phase functions of optically thin cirrus clouds in a water vapor absorption channel (1.38-µm). We estimate the ice crystal habits and surface structures by comparing the inferred scattering phase functions and numerically simulated phase functions calculated using idealized habits.

No description available.

Geomorphic, structural and chronological data are used to establish the late Quaternary paleoseismicity of the active dextral-oblique Northern Esk Fault in North Canterbury, New Zealand. Detailed field mapping of the preserved c. 35 km of surface traces between the Hurunui River and Ashley Head reveals variations in strike ranging from 005° to 057°. Along with kinematic data collected from fault plane striae and offset geomorphic markers along the length of the fault these variations are used to distinguish six structural subsections of the main trace, four dextral-reverse and two dextral-normal. Displacements of geomorphic markers such as minor streams and ridges are measured using differential GPS and rangefinder equipment to reveal lateral offsets ranging from 3.4 to 23.7 m and vertical offsets ranging from < 1 to 13.5 m. Characteristic single event displacements of c. 5 m and c. 2 m have been calculated for strike-slip and reverse sections respectively. The use of fault scaling relationships reveals an anomalously high displacement to surface rupture length ratio when compared to global data sets. Fault scaling relationships based on width limited ruptures and magnitude probabilities from point measurements of displacement imply earthquake magnitudes of Mw 7.0 to 7.5. Optically Stimulated Luminescence (OSL) ages from displaced Holocene alluvial terraces at the northern extent of the active trace along with OSL and radiocarbon samples of the central sections constrain the timing of the last two surface rupturing events (11.15 ±1.65 and 3.5 ± 2.8 ka) and suggest a recurrence interval of c. 5612 ± 445 years and late Quaternary reverse and dextral slip rates of c. 0.31 mm/yr and 0.82 mm/yr respectively. The results of this study show that the Northern Esk Fault accommodates an important component of the c. 0.7 – 2 mm/yr of unresolved strain across the plate boundary within the North Canterbury region and affirm the Esk Fault as a source of potentially damaging ground shaking in the Canterbury region.

The Indo-Australian Plate is actively deforming at its margins and within its interior. In south-central Australia, more than 3000 km from the closest active plate boundary, a geomorphically rugged and apparently youthful mountain range has developed, rising up to 1.1km above the adjacent flat-lying outback plains. These ‘Flinders’ and ‘Barrier’ Ranges are seismically active and bound by major reverse fault scarps with clear evidence for Plio-Quaternary displacements, implying that young and active intraplate tectonism has played a fundamental role in their development. Palaeoseismic investigations and optically stimulated luminescence (OSL) chronology indicate faulting occurred in response to a series of large magnitude (~M6.6 to M7.3) palaeo-earthquakes with recurrence intervals of ~1:20,000 to~1:80,000 yrs and long-term fault slip rates of ~50 m Myr-1. Geomorphic observations and 10Becosmogenic nuclide dating indicate surprisingly high and spatially variable rates of bedrock erosion from fault-affected catchments in the Flinders Ranges. Slowly eroding bedrock summit surfaces have been uplifted up to 12 m in the last 60,000-100,000 years relative to more rapidly eroding valley floors and bounding piedmonts, indicating Late Quaternary increases in elevation and relief in response to intraplate tectonism and erosion. However, both facies changes and sediment aggradation-dissection cycles in alluvial fan sequences are out-of-synch within dividual tectonic events, indicating that an aspect of climate (aridification, changing flood frequency-magnitude distributions) has governed the spatial-temporal distribution of range front sedimentation.

La magnétocardiographie (MCG) et la magnétoencéphalographie (MEG) sont deux techniques d'imagerie non-invasives mesurant respectivement les champs magnétiques cardiaques et cérébraux. Les dispositifs actuels utilisent des capteurs supraconducteurs de haute performance mais nécessitant un dispositif de refroidissement cryogénique, engendrant de fortes contraintes tant techniques que financières. Les magnétomètres à pompage optique (OPM) tendent à constituer une réelle alternative. Parmi eux figurent ceux développés au CEA-LETI, basés sur l'utilisation de l'hélium 4. Cette thèse a pour objectif de développer des magnétomètres vectoriels à 4He (fonctionnant à température ambiante) dédiés aux applications MCG et MEG.Après une optimisation des paramètres-clés d'un prototype non-miniaturisé préexistant, une sensibilité inférieure à 100 fT/sqrt(Hz) a pu être obtenue suivant deux axes. Afin de respecter les besoins spécifiques de la MCG et de la MEG une étape de miniaturisation a dû être menée et une architecture gradient-métrique a été mise en place. Parallèlement, des tests précliniques menés à Clinatec nous ont permis de concevoir un nouveau conditionnement du prototype, ainsi qu'un système réduisant les perturbations magnétiques. Une analyse des principales sources de bruit a révélé que les deux principaux contributeurs au bruit sont le laser et le système de décharge HF. Nous avons ainsi envisagé plusieurs pistes d'amélioration du niveau de bruit dont une nouvelle technique de détection. Le prototype issu de ces travaux comporte une pièce élémentaire (la cellule) d'un centimètre de côté, et présente une sensibilité intrinsèque de 350 fT/sqrt(Hz).Le dispositif a ensuite été testé avec succès dans le cadre de mesures MCG sur un sujet sain, précédées de tests sur fantôme ayant permis de prouver l'opérabilité de nos capteurs dans un environnement clinique. Par ailleurs, la reproductibilité des résultats ainsi que la possibilité de réduire à 30 s le temps d'acquisition des données ont pu être démontrées. Une optimisation spécifique de la partie optique du prototype a permis d'obtenir une sensibilité de l'ordre de 210 fT/sqrt(Hz) entre 3 et 300 Hz, compatible avec l'application MEG. Après des tests menés avec succès sur fantôme, trois séries d'essais ont été réalisées sur un sujet sain. Nous avons pu ainsi détecter des potentiels évoqués auditifs, visuels ainsi qu'une modulation de l'activité cérébrale spontanée sous l'effet de l'ouverture des paupières. L'ensemble des résultats obtenus constitue les premières preuves de concept cliniques du dispositif en MCG et MEG. / Magnetocardiography (MCG) and magnetoencephalography (MEG) are non-invasive techniques consisting in measuring respectively cardiac and brain magnetic fields. Despite their performance, the sensors currently used need a cryogenic cooling system which engenders technical and financial constraints. New cryogenic-free sensors have recently emerged: the OPMs (Optically-Pumped Magnetometers). Among them, vector 4He magnetometers developed by CEA-LETI which work at room-temperature. This thesis is focused on the development of 4He magnetometers dedicated to MCG and MEG.After having optimized the key-parameters of a first non-miniaturized prototype, a sensitivity inferior to 100 fT/sqrt(Hz) has been obtained along two axes. In order to meet biomedical constraints, a miniaturization of the device has been processed. In parallel, preclinical tests were carried out which have enabled us to design a gradiometer mode, a new packaging, and a magnetically isolated system. A noise analysis revealed that laser and HF discharge were the main sources of disturbance, and lead us to consider improvements such as a new detection mode. Eventually, a sensor, with a 1cm-sided cell, and an intrinsic sensitivity of 350 fT/√Hz has been developed.Then, device has been successfully tested in the frame of the MCG application from a healthy subject, preceded by a simulation study with a phantom which enables us to demonstrate its operability within a clinical environment. Moreover, we have proved the reproducibility of the measurements and the possibility to detect the main features of the cardiac cycle within a 30 s recording time. A specific optimization of the optical part has enabled us to obtain a 210 fT/sqrt(Hz) sensitivity between 3 and 300 Hz, suitable for the MEG application. After having tested our device with a phantom, three MEG experiments were performed with a healthy subject: auditory evoked field, visual evoked field and spontaneous activities have been detected. The obtained results form the first clinical proof of concept of the device for MCG and MEG applications.

O presente trabalho tem como objetivo a reconstrução da história evolutiva ao longo do Holoceno da planície costeira de cordões litorâneos estabelecidos sobre o vale fluvial do Rio Itabapoana/ES. A partir desse objetivo, foram realizadas as seguintes etapas metodológicas: Sensoriamento Remoto, Topografia, Geofísica e Geocronologia. Através da análise da imagem de satélite RapidEye, na composição colorida R5-G3-B1, foram discriminadas classes de cobertura vegetal. A relação entre a vegetação e o solo exposto proporcionou a identificação de três padrões distintos na planície costeira de cordões litorâneos. A obtenção de dados contínuos de altimetria através de um sistema global de navegação por satélite (GNSS), concentrado no caminhamento perpendicular à linha de costa, permitiu a elaboração e análise do perfil altimétrico dos cordões litorâneos, identificando-se três principais características: 1) nos primeiros 600 m tem-se um acréscimo na elevação; 2) em seguida, uma longa faixa “estável”, de pouca mudança na elevação; 3) por fim, o decréscimo da elevação nos últimos 500 m. Para caracterizar a arquitetura deposicional em subsuperfície dos cordões litorâneos, utilizou-se um Radar de Penetração no Solo (GPR) O registro obtido com GPR possibilitou a identificação de três padrões, representados pelas unidades retrogradacional e progradacional, onde o padrão de empilhamento compõe uma sequência de barreira regressiva ou progradante. Para a obtenção de uma relação cronoestratigráfica, seis amostras de sedimentos da fração arenosa de deposição eólica foram coletadas para a obtenção de idades absolutas a partir de Luminescência Opticamente Estimulada (LOE). Os cordões datados apresentaram idades holocênicas, com idades inferiores a 5.261 ± 396 anos. A integração dos resultados obtidos através dos métodos aplicados permitiu o reconhecimento de três padrões que levaram à interpretação de três fases decorrentes das variações do nível relativo do mar e do aporte sedimentar na evolução da planície. Essas fases representam os períodos de transgressão, regressão normal e regressão forçada. / The aim of this study is the reconstruction of the evolutionary history along the Holocene of the of beach ridges coastal plain established on the fluvial valley of Itabapoana River/ES. From this objective, the following methodological steps were performed: Remote Sensing, Topography, Geophysics and Geochronology. Through the analysis of the RapidEye satellite image, in the color composition R5-G3-B1, classes of vegetal cover were discriminated. The relationship between vegetation and exposed soil provided the identification of three distinct patterns of the beach ridges coastal plain. Obtaining continuous data of altimetry with a GNSS system, concentrated in the path perpendicular to the coastline, allowed the elaboration and analysis of the altimetric profile of the beach ridges. It was identified three main characteristics: 1) in the first 600 m there is an increase in elevation; 2) then along “stable” stretch, with little change in elevation; 3) lastly, the decrease of the elevation in the last 500 m. A Ground Penetrating Radar (GPR) was used to characterize the depositional architecture in the subsurface of the beach ridges The GPR record allowed the identification of three patterns, represented by the retrogradational and progradational units, in which the stacking pattern consists of a regressive or progradational barrier sequence. Six sediment samples of the sandy fraction of wind deposition were collected to obtain absolute ages from Optically Stimulated Luminescence (OSL). The dated ridges presented Holocene ages, with ages lower than 5,261 ± 396 years. The integration of the results obtained allowed the recognition of three patterns that led to the interpretation of three phases due to the variations of the relative sea level and the sedimentary budget in the evolution of the plain. These phases represent periods of transgression, normal regression and forced regression.

A dosimetria in vivo têm se tornado um papel importante para o tratamento da irradiação total da pele dentro de um rigoroso programa de garantia de qualidade que deve ser parte integrante nos departamentos radioterápicos. A dosimetria em TSI é difícil, devido à complexidade do tratamento em avaliar a uniformidade da dose e medir a dose absorvida em profundidades rasas em toda extensão da superfície cutânea, tendo como consequência uma ampla variação na distribuição da dose. Os TLDs tem provado ser muito úteis para a distribuição e verificação da dose prescrita para o paciente, pois a dose pode diferir de local para local devido a geometria do corpo do paciente, sobreposições de estruturas e assimetrias do campo de radiação. A utilização de TLDs in vivo pode identificar variações da dose prescrita por apresentarem uma grande exatidão e precisão nas medidas. Nos setores de radioterapia vêm sendo empregado vários tipos de dosímetros, os mais utilizados são o Flureto de Lítio (TLD-100), onde obtém uma longa história neste tipo de aplicação. Novos materiais dosímetricos vêm ganhado grande importância na aplicação da dosímetria de feixes clínicos de elétrons, como o Sulfato de Cálcio dopado com Disprósio (TL) e o Óxido de Alumínio dopado com Carbono (OSL), este trabalho avalia o desempenho dosímetrico dos respectivos dosímetros termoluminescentes e a luminescência opticamente estimulada na aplicação da dosímetria de feixes clínicos de elétrons utilizados na irradiação total da pele. / In vivo dosimetry has become an important role for the treatment of total skin irradiation within a rigorous quality assurance program that should be an integral part of the radiotherapy departments. TSI dosimetry is difficult because of the complexity of the treatment in assessing dose uniformity and measuring the dose absorbed at shallow depths throughout the skin surface extent, resulting in a wide variation in dose distribution. The TLDs have proven to be very useful for the distribution and verification of the dose prescribed for the patient as the dose may differ from place to place due to patient body geometry, overlapping of structures and asymmetries of the radiation field. The use of TLDs in vivo can identify variations in the prescribed dose because its measurement accuracy and great precision. Several types of dosimeters have been used in the radiotherapy sectors, the most commonly used are Lithium Fluride (TLD-100), where it obtains a long history in this type of application. New dosimetric materials have gained great importance in the dosimetry of clinical electron beams, such as Dysprosium-doped Calcium Sulphate (TL) and Carbon doped (OSL) based Aluminum Oxide, This work evaluates the performance of the respective thermoluminescent dosimeters and the optically stimulated luminescence in the dosimetry of clinical electron beams used in total irradiation of the skin.

O presente trabalho tem como objetivo a reconstrução da história evolutiva ao longo do Holoceno da planície costeira de cordões litorâneos estabelecidos sobre o vale fluvial do Rio Itabapoana/ES. A partir desse objetivo, foram realizadas as seguintes etapas metodológicas: Sensoriamento Remoto, Topografia, Geofísica e Geocronologia. Através da análise da imagem de satélite RapidEye, na composição colorida R5-G3-B1, foram discriminadas classes de cobertura vegetal. A relação entre a vegetação e o solo exposto proporcionou a identificação de três padrões distintos na planície costeira de cordões litorâneos. A obtenção de dados contínuos de altimetria através de um sistema global de navegação por satélite (GNSS), concentrado no caminhamento perpendicular à linha de costa, permitiu a elaboração e análise do perfil altimétrico dos cordões litorâneos, identificando-se três principais características: 1) nos primeiros 600 m tem-se um acréscimo na elevação; 2) em seguida, uma longa faixa “estável”, de pouca mudança na elevação; 3) por fim, o decréscimo da elevação nos últimos 500 m. Para caracterizar a arquitetura deposicional em subsuperfície dos cordões litorâneos, utilizou-se um Radar de Penetração no Solo (GPR) O registro obtido com GPR possibilitou a identificação de três padrões, representados pelas unidades retrogradacional e progradacional, onde o padrão de empilhamento compõe uma sequência de barreira regressiva ou progradante. Para a obtenção de uma relação cronoestratigráfica, seis amostras de sedimentos da fração arenosa de deposição eólica foram coletadas para a obtenção de idades absolutas a partir de Luminescência Opticamente Estimulada (LOE). Os cordões datados apresentaram idades holocênicas, com idades inferiores a 5.261 ± 396 anos. A integração dos resultados obtidos através dos métodos aplicados permitiu o reconhecimento de três padrões que levaram à interpretação de três fases decorrentes das variações do nível relativo do mar e do aporte sedimentar na evolução da planície. Essas fases representam os períodos de transgressão, regressão normal e regressão forçada. / The aim of this study is the reconstruction of the evolutionary history along the Holocene of the of beach ridges coastal plain established on the fluvial valley of Itabapoana River/ES. From this objective, the following methodological steps were performed: Remote Sensing, Topography, Geophysics and Geochronology. Through the analysis of the RapidEye satellite image, in the color composition R5-G3-B1, classes of vegetal cover were discriminated. The relationship between vegetation and exposed soil provided the identification of three distinct patterns of the beach ridges coastal plain. Obtaining continuous data of altimetry with a GNSS system, concentrated in the path perpendicular to the coastline, allowed the elaboration and analysis of the altimetric profile of the beach ridges. It was identified three main characteristics: 1) in the first 600 m there is an increase in elevation; 2) then along “stable” stretch, with little change in elevation; 3) lastly, the decrease of the elevation in the last 500 m. A Ground Penetrating Radar (GPR) was used to characterize the depositional architecture in the subsurface of the beach ridges The GPR record allowed the identification of three patterns, represented by the retrogradational and progradational units, in which the stacking pattern consists of a regressive or progradational barrier sequence. Six sediment samples of the sandy fraction of wind deposition were collected to obtain absolute ages from Optically Stimulated Luminescence (OSL). The dated ridges presented Holocene ages, with ages lower than 5,261 ± 396 years. The integration of the results obtained allowed the recognition of three patterns that led to the interpretation of three phases due to the variations of the relative sea level and the sedimentary budget in the evolution of the plain. These phases represent periods of transgression, normal regression and forced regression.

Atualmente a utilização de fótons de raios X e gama na Medicina (radiodiagnóstico e radioterapia) gerou a necessidade do conhecimento da dose absorvida nos tecidos dos pacientes. Para isso, utiliza-se detectores com diversas funcionalidades a fim de conhecer a deposição de energia. Para ser possível a utilização destes materiais, é necessário caracterizá-los tanto quanto à resposta em função da dose absorvida, quanto à dependência com a energia. Neste trabalho foi estudada a dependência energética da resposta OSL dos dosímetros compostos por BeO e Al2O3 em feixes de raios X convencional com espectro largo, feixes de raios X de aceleradores clínicos e do acelerador Microtron do Instituto de Física da USP e fontes gama de Cs-137 e Co-60, em uma faixa de doses desde centenas de mGy até aproximadamente 2 Gy. Foram utilizadas em conjunto simulações em Monte Carlo com o código PENELOPE, que simula o transporte de fótons e elétrons na matéria, a fim de conhecer a deposição de energia nos materiais. Os espectros utilizados nas simulações foram validados através da comparação das características dos feixes tais como a deposição de dose com a profundidade, camada semirredutora, energia média e resolução espectral. Utilizando um sistema de varredura por câmara de ionização controlado remotamente, foi estudada a distribuição de doses no campo de irradiação para definir uma região de irradiação com dose uniforme para pode realizar a irradiação de um conjunto de dosímetros simultaneamente. Foram encontrados valores do fator de dependência energética experimental para os feixes mais energéticos (Co-60, Microtron 5 MeV e aceleradores clínicos de 6 e 15 MeV), com desvio menor que 3% para o Al2O3 e 5% para o BeO, indicando independência com a energia do feixe de irradiação. Já nos feixes de baixa energia, os fatores de dependência energética relativos à energia do Co-60 para o Al2O3 foram de 1,68 e 1,42, e, para o BeO, de 0,78 e 0,90 para os feixes W150 e W200 respectivamente. Estes valores indicam que, nesta faixa de energia, a resposta OSL depende mais fortemente da energia do feixe. As simulações em Monte Carlo feitas para os fatores de dependência energética se mostraram bem consistentes com os valores experimentais para o BeO em toda faixa de energia e para o Al2O3, excetuando-se os feixes de baixa energia, possivelmente pelo não completo conhecimento de todos os elementos constituintes do dosímetro empregado (fita de Luxel®). Quanto às curvas de emissão OSL para as diferentes energias de irradiação, foi observado que o sinal decai mais rápido quanto mais elevada é a energia média do feixe para o BeO. Para o Al2O3, o efeito foi mais sutil e oposto. Os estudos do feixe do Microtron mostraram que, desde que a corrente seja monitorada durante as irradiações para posterior correção da dose, é possível realizar estudos utilizando um feixe de fótons de Bremsstrahlung produzido com alvo externo e energias médias (simuladas e ainda não validadas experimentalmente) próximas às energias das fontes gama de Cs-137 e Co-60. Os resultados experimentais para as respostas OSL dos dois materiais foram compatíveis com as simulações. / Nowadays the use of X and gamma-ray photons in Medicine (radiodiology and radiotherapy) has generated the necessity of knowing the absorbed dose to the tissues of patients. For this purpose, detectors with diverse functionalities are used to know the energy deposition. To make possible the use of these materials, it is necessary to characterize the dose response, as well as the energy dependence of the response. In this work the energy dependence of the OSL response of the BeO and Al2O3 dosimeters was studied for conventional X-ray beams with wide energy spectrum, X-ray beams from clinical accelerators and from the Microtron accelerator of the Institute of Physics (University of São Paulo), and for gamma sources of Cs-137 and Co-60, in a dose range from hundreds of mGy to about 2 Gy. Monte Carlo simulations were used with the PENELOPE code, which simulates the photons and electrons transport of in the matter, to know the energy deposition in the materials. The energy spectra used in simulations were validated by comparison with beam characteristics such as depth dose deposition, half-value layer, mean energy and spectral resolution. Using a remotely controlled ionization chamber scanning system, the dose distribution within the irradiation field was evaluated to define a uniform dose region for irradiation or a set of dosimeters simultaneously. Experimental energy dependence factor values were obtained for the high-energy beams (Co-60, Microtron 5 MeV, and clinical accelerators of 6 and 15 MeV), with a deviation of less than 3% for Al2O3 and 5% for BeO, indicating independence with the beam energy. For the low-energy X-ray beams, the energy dependence factors, relative to the Co-60 energy, for Al2O3 were 1.68 and 1.42, and, for BeO, 0.78 and 0.90 for W150 and W200 beams respectively. These values indicate that, in this energy range, the OSL response depends on beam energy. Monte Carlo simulations for the energy dependence factors were consistent with experimental values for the BeO in entire energy range and for the Al2O3, with the exception of low energy beams, possibly due to the incomplete knowledge of all the elements that constitute the Luxel®. As for the shape of OSL emission curves for the different irradiation energies, it was observed that the signal decays faster the higher is the average beam energy for BeO. For Al2O3, the effect was more subtle and opposite. The Microtron beam scanning has shown that, as long as the current is monitored during irradiation for further dose-rate correction, it is possible to carry out studies using a beam of Bremsstrahlung photons produced with external target and mean energies (simulated but still not validated experimentally) close to the energies of the Cs-137 and Co-60 sources. The experimental results for the OSL responses of both materials were compatible with simulations.