Submitted PHD thesis is focused on fracturing process of migmatite, which is a low porosity anisotropic rock. Migmatite, from a locality Skalka, was chosen as a suitable experimental material, namely due to its macroscopically visible, plane-parallel structure (foliation). The fracturing was studied by means of uniaxial loading experiments on cylindrical samples with different dip of migmatite foliation: 13ř (subhorizontal), 81ř (subvertical) and oblique (47ř and 67ř). The net of eight piezoceramic transducers was employed for ultrasonic sounding (US) measurement and acoustic emission (AE) monitoring during the loading experiments. Realized study of migmatite fracturing is based on the interpretation of both mentioned ultrasonic methods. Part of this work was a software development, including its testing for processing and interpretation of measured AE and US data. Methodical part of the thesis consists of: development and testing of algorithms for automatic P wave arrival detection; introduction of anisotropic velocity model to describe magnitude and orientation of velocity anisotropy, as well as to localize AE events in anisotropic velocity field; determination of crack initiation stress using first arrival amplitude of US. Based on the interpretation of AE and US data, there was found a...

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The ionosphere is a constantly changing medium. From the sun to cosmic rays, the ionosphere proves to be a continually interesting area of study. The most notable change that occurs in the ionosphere is the day and night cycle. The ionosphere is not a singular medium, but rather made up of different sections. The day side of the ionosphere consists of a D, E, F1, and F2 layer. The night day of the ionosphere consists of an E and F layer. These layers all have different properties and characteristics associated with them. A notable interaction is how radio waves propagate through the ionosphere. A radio wave can either reflect, refract, or pass through a layer of the ionosphere depending on the frequency of the signal, among other sources of disturbance. The ability to have a radio wave reflected back downwards is a core principle of an ionosonde, which measures the height of the ionosphere. A solar eclipse presents a night side ionosphere condition during the day. The change in the ionosphere that the eclipse will cause is something not a lot of research has gone into. This thesis aims to elaborate on the design and development of an ionosonde along with eventual ionosphere readings during the August 2017 total solar eclipse. / Master of Science / The atmosphere that surrounds the earth is made up of various unique regions. The region of interest for this thesis is the ionosphere. The ionosphere plays an important role in wireless communication of radio waves. It follows that changes in the ionosphere are something of great interest and study. A notable change that the ionosphere undergoes on a daily basis is the shift from the day side to the night side. A solar eclipse serves not only as a spectacular sight, but also to bring a night side condition to the day side. This thesis aims to uncover the changes that will occur to the ionosphere during the August 2017 total solar eclipse.

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<p dir="ltr">Bridge decks in Indiana face the brunt of the deterioration mechanisms associated with structural deficiencies. These deficiencies do not always present themselves in noticeable ways, however, their detection is imperative to the performance of the deck and the bridges’ overall health. The inspection of these bridge decks presents engineers with not only a timely, but dangerous process as maintenance of traffic (MOT) from the states’ department of transportation (DOT) is not a viable option for most inspections. This results in engineers taking an unnecessary risk to inspect these decks for deteriorations. The most detrimental of these structural deficiencies, delaminations, do not always result in visual confirmation. Leading to more time spent in the roadway trying to sound for these defects. This thesis introduces a state-of-the-art review of previous NDT studies in relation to bridge structures along with the validation of their results. Background information on all testing methods being evaluated will also be provided in this study. This thesis also presents an in depth investigation using multiple consultants and a variety of NDT methods to assess the viability of delamination detection in relation to these methods. These methods were verified through coring at select locations on the deck. This thesis then discusses the practical implications of these NDT methods that provide an accurate level of delamination detection on project and network level inspections.</p>

This study focused on determining the groundwater flow paths in the crystalline subsurface rocks of the Bulawayo metropolitan, Zimbabwe, through analysing the discontinuities of the electrical properties of the ground, as well as in the magnetic field of the underlying rocks. Further, borehole water quality was analysed by measuring and mapping several chemical parameters, specifically TDS, salinity and the electrical conductivity. The electrical and magnetic anomalies were measured at two field sites within the Bulawayo province, the Harry Allen Golf Course and the Barbour Fields dumpsite, while 120 boreholes were sampled for water quality in a large part the province. Two magnetometers were used to measure the magnetic field and the time and location of the measurements, which resulted, after processing in SURFER, into the magnetic field map of these areas. This was used, in conjunction with the geologic map of the Bulawayo province, in order to determine useful locations for the electrical resistivity surveys. These included electrical resistivity tomography and vertical electrical sounding and were performed with an earth resistivity/induced polarization (IP) meter in order to measure the electrical resistivity of the ground. Inverse modelling was used in the RES2DINV software program to produce the topographic image of resistivity. The results for the borehole sampling showed that the maps for the three chemical parameters were very similar, with the western and northern parts of the mapped area displaying higher concentration values. The results of the electrical resistivity surveying showed probable areas of groundwater flow with its relationship to electric conductivity.

Cette thèse résume trois années de travail dans le domaine de la caractérisation large bande du canal radio pour des applications projectiles. L’instrumentation des projectiles évolue avec la miniaturisation de l’électronique et l’accroissement constant de ses performances. L’échange de données par liaison sans fil bi-directionnelle entre le projectile et lastation de base doit s’effectuer aussi efficacement que possible. Afin de répondre à cette exigence, il est fondamental d’optimiser chaque élément de la chaîne de communication. Le canal, qui est le support où la propagation des ondes radio prend place, est l’un des éléments à modéliser.Dans le but de caractériser le canal radio pour ces applications, cette thèse a été structurée en cinq chapitres: dans les premier et deuxième chapitres, le contexte général de la thèse est présenté, introduisant le cadre de la thèse et donnant les éléments nécessaires pour comprendre le reste du manuscrit. Au chapitre trois, nous abordons le problème du développement des briques nécessaires pour caractériser le canal de propagation. Une des contributions de cette thèse est la définition d’un ensemble de procédures pour effectuer une modélisation de canal. Au chapitre quatre et cinq, nous présentons nos résultats. Alors qu’au chapitre quatre une étude préliminaire du canal est effectuée, une caractérisation complète est donnée au chapitre cinq. Les chapitres se terminent par la présentation d’un modèle de canal dédié aux simulations de communications numériques afin d’améliorer la liaison avec le projectile. Dans une dernière étape, les conclusions et les questions ouvertes sont détaillées. / This thesis summarizes three years of work in the field of wideband characterization of the radio channel in projectile applications. The popularization of the miniaturized electronics has allowed the instrumentation of projectiles. The information gathered by the onboard sensors needs to be sent from the projectile to the base station as efficiently as possible by means of bi-directional communication links. In order to fulfill this requirement, it is fundamental to optimize every element in the communication chain. The channel, which is the medium where the radio wave propagation takes places, is one of the elements to be modeled. With the purpose of characterizing the radio channel in projectile applications, this thesis has been structured in five chapters: in chapter one and two, the general context of the thesis is presented, introducing the reader to this topic and giving the necessary elements to understand the rest of the manuscript. In chapter three, we address the problem of developing the necessary elements in order to characterize the propagation channel. The first contribution of this thesis is found here in the form of a set of procedures to perform channel modeling. In chapter four and five, we present our results. While chapter in chapter four a preliminary study of the channel is performed, in chapter five a complete characterization is given. The chapters ends with the presentation of the second contribution of this thesis, i.e.a channel model to be used in simulations in order to improve the projectile communication link. In a last stage, the conclusions and open questions are detailed.

O presente trabalho de mestrado está inserido nos estudos de refração profunda do Projeto Temático 'Estudos Geofísicos e Modelo Tectônico dos Setores Central e Sudeste da Província Tocantins, Brasil Central'. Nesses estudos foram levantadas três linhas de refração de aproximadamente 300 km de extensão, duas no setor Central da Província Tocantins e uma no setor Sudeste, que é o objeto de estudo deste trabalho. Foram utilizados 111 sismógrafos digitais SGR pertencentes ao programa PASSCAL, instrumentos auxiliares do USGS, e 13 sismógrafos digitais e instrumentos auxiliares do IAG/USP. A linha sísmica teve aproximadamente 300 km de extensão com pontos de registro separados a cada 2,5 km, distribuídos ao longo de estradas principais e secundárias. A cada 50 km, aproximadamente, foi realizada uma explosão, nas explosões dos extremos da linha foram utilizados 1000 kg de explosivo e para a explosão central uma carga de 500 kg. Para a determinação das coordenadas geográficas dos pontos de tiro e de registro, foi utilizado o método diferencial com medidas de GPS. O principal objetivo deste trabalho foi obter como produto final um modelo de velocidades sísmicas contendo as características físicas das principais descontinuidades na crosta terrestre e no manto superior. Para análise e processamento dos dados foram utilizados os pacotes SAC, SU, SEIS. Para a modelagem foram utilizados a teoria do raio e a elaboração de sismogramas sintéticos, do pacote SEIS. Para a elaboração do modelo final foram utilizados os dados das explosões dos pontos extremos e central, tendo em vista que devido a problemas técnicos não foram registrados os sinais das outras 4 explosões. Além disso, as explosões registradas não apresentaram sinais claros em toda a extensão da linha. Devido a tudo isso e considerando as unidades geológicas presentes na região de estudo são sugeridos três modelos de velocidades sísmicas. O primeiro modelo refere-se ao tiro direto (EX31) localizado no extremo sudoeste da linha, sobre a Bacia do Paraná. Para este modelo obteve-se para superfície (0 km) a velocidade inicial de 2 km/s (coberturas); para a profundidade de 0,086 km a velocidade inicial é de 5,15 km/s (basalto); para a profundidade de 0,350 km obteve-se a velocidade inicial de 4,6 km/s (arenito - camada de baixa velocidade); para profundidade de 0,650 km a velocidade inicial é de 5,75 km/s e para profundidade de 4 km obteve-se a velocidade inicial de 6,07 km/s. O segundo modelo refere-se ao tiro reverso (EX34) localizado no centro da linha sobre granitóides do Grupo Araxá. Para este modelo obteve -se para superfície (0 km) a velocidade inicial de 2 km/s; para a profundidade de 0,06 km a velocidade inicial é de 5,69 km/s e para a profundidade de 0,860 km obteve-se a velocidade inicial de 6,25 km/s. Finalmente, o terceiro modelo refere-se ao tiro direto para toda a extensão da linha (300 km). Este modelo foi definido a partir de fases secundárias lidas nos registros e modelos anteriores propostos na literatura. Da superfície até os 4 km iniciais de profundidade este modelo é igual ao primeiro, para uma profundidade de 20 km obteve-se a velocidade inicial de 6,70 km/s e para uma profundidade de 40 km a velocidade é de 8,00 km/s (descontinuidade de MOHO). / This work to fulfil the degree of Master of Sciences is inserted among the deep seismic refraction studies of the Thematic Project 'Geophysical Studies and Tectonic Model of the Tocantins Province Central and Southeast Sectors, Central Brazil'. Three refraction lines, of around 300 km long each, were deployed, two of them in the Central sector and the other in the SE sector, that is subject of the present work. The equipment used in this experiment was composed by 111 SGR digital seismographs belonging to the PASSCAL Program. Complemented with auxiliary instruments from USGS and 13 seismographs belonging to IAG/USP. The space among the recording points was 2.5 km, which were located along main and secondary roads. Every 50 km was fired an explosion with 1000 kg of emulsion in each extreme and 500 kg in the central point. The geographical co-ordinates were determined by using the GPS differential method. The main objective of this work is to obtain as a final product a seismic velocity model with the physical characteristics of the main discontinuities in the crust and upper mantle. The packages SAC, SU and SEIS were used to perform the data analysis and processing. To carry on the modelling were used the ray theory and the synthetic seismograms construction, belonging to the SEIS package Data from the extreme and middle points of the seismic line were used to elaborate the final model, considering that due to technical problems signals from the other four explosions were not recorded. Apart from that, the recorded explosions did not present clear signals all along the extension of the line. Due to these facts, and considering also the geological units present in the studied region, are suggested three seismic velocity models. The first model is referred to the direct shot (EX31), which is localised in the Southwest extreme of the line on the Parana Basin province. In this model we obtained the P wave velocity (VP) of 2 km/sec at the surface, corresponding to the unconsolidated sediments and soil on the top of that basin. At a depth of 86 m we found VP of 5,15 km/sec and at a depth of 350 m the velocity VP of 4,6 km/sec, corresponding to the basalt and sand layers of the Parana Basin. Underlying them, at 650 m of depth we found the basement with VP of 5,75 km/sec and finally at a depth of 4 km there is a layer with VP of 6,07 km/sec, corresponding to a typical upper crust P wave velocity. The second model corresponds to the reverse shot (EX34) that is localised in the middle point of the line on the granitoides of the Araxa Group. For this model we obtained VP of 2 km/sec for the superficial layers, then at a depth of 60 m was obtained V P of 5,69 km/sec and for a depth of 860 m the value of V P is 6,25 km/sec. Finally, the third model belongs to the whole line section (300 km) from the direct shot (EX31). This model was obtained by using the arrivals of secondary phases and the results of models proposed in other works. From the surface down to 4 km of depth this model is similar to the first one. At 20 km of depth there is a layer with VP of 6,70 km/sec, corresponding to the lower crust, with Moho at a depth of 40 km with VP of 8,00 km/sec.