Snow accumulation patterns can be highly variable depending on terrain and wind. Knowledge of spatial variability of snow accumulation is of high relevance for mass balance modelling. By not incorporating the variability in snow cover, the estimation in mass fluxes and the surface melt are incorrectly presented, affecting the eventual estimation of for instance contribution to sea level rise. Additionally, knowledge of snow accumulation variability is essential for assessing the reliability of point-wise mass balance measurements. Using ground penetrating radar (GPR), the spatial variability of snow can be mapped with both a great spatial and temporal resolution. GPR enables tracing of summer surface melt layers, resulting in a 2D reconstruction of past snow accumulation and associated variability. GPR measurements have been done on Svalbard, during 2012, 2013 and 2014. Based on the selected 2009 summer surface in the GPR measurements, accumulation rates were estimated between 2009-2012; 2009-2013 and 2009-2014. In addition, several terrain parameters are computed by combining DEM calculations with wind direction, resulting in a sheltering index, slope and curvature. We explore relationships between the found accumulation pattern and the terrain parameters with varying wind directions. Correlations between terrain and accumulation depend on the selected wind angle, which appears to change with elevation. The results suggest that localized wind patterns prevail on the glacier and shape the snow cover. Katabatic winds form at low elevations on the glacier and are oriented in the glacier direction of approximately 20 degrees. At intermediate elevation, winds from the east-southeast regulate the accumulation pattern. On the upper parts of the glacier, the terrain is more exposed and winds from large-scale atmospheric circulation, at 240 degrees, become more important in formation of the snow accumulation pattern. Correlations are overall high, indicating a strong influence of terrain features on the accumulation distribution. No distinction can be made between the different terrain parameters and accumulation, all returning similar correlations with accumulation except for curvature, which overall returns slightly lower correlations. In addition, the results found great spatial variability in snow accumulation, underlining the importance of incorporating snow accumulation variability in glacier mass balance models. / Snow accumulation patterns can be highly variable depending on terrain and wind. Knowledge of spatialvariability of snow accumulation is of high relevance for mass balance modelling. By not incorporating the variability in snow cover, the estimation in mass fluxes and the surface melt are incorrectlypresented, affecting the eventual estimation of for instance contribution to sea level rise. Additionally,knowledge of snow accumulation variability is essential for assessing the reliability of point-wise mass balance measurements.Using ground penetrating radar (GPR), the spatial variability of snow can be mapped with both agreat spatial and temporal resolution. GPR enables tracing of summer surface melt layers, resulting in a 2D reconstruction of past snow accumulation and associated variability. GPR measurements have been done on Svalbard, during 2012, 2013 and 2014. Based on the selected 2009 summer surface in the GPR measurements, accumulation rates were estimated between 2009-2012; 2009-2013 and 2009-2014. In addition, several terrain parameters are computed by combining DEM calculations with wind direction, resulting in a sheltering index, slope and curvature. We explore relationships between the found accumulation pattern and the terrain parameters with varying wind directions.Correlations between terrain and accumulation depend on the selected wind angle, which appears to change with elevation. The results suggest that localized wind patterns prevail on the glacier and shape the snow cover. Katabatic winds form at low elevations on the glacier and are oriented in the glacier direction of approximately 20 degrees. At intermediate elevation, winds from the east-southeast regulate the accumulation pattern. On the upper parts of the glacier, the terrain is more exposed and winds from large-scale atmospheric circulation, at 240 degrees, become more important in formation of the snow accumulation pattern. Correlations are overall high, indicating a strong influence of terrain features on the accumulation distribution. No distinction can be made between the different terrain parameters and accumulation, all returning similar correlations with accumulation except for curvature, which overall returns slightly lower correlations. In addition, the results found great spatial variability in snowaccumulation, underlinin

Linhagens secretoras de insulina, como a BRIN-BD11, são utilizadas para o estudo do mecanismo de secreção de insulina estimulado pela glicose (GSIS). Essas células expressam o GPR40, que quando ativado por ácidos graxos (AG), potencializam a GSIS. Considerando que as espécies reativas de oxigênio (EROs) podem estar relacionadas com a secreção de insulina mediada por AG, este estudo tem como foco avaliar se há envolvimento do GPR40 na GSIS e na produção de EROs, via NADPH oxidase (NADPHox), em células BRIN-DB11. A ativação do GPR40 foi feita com agonista GW9508 (GW). A secreção de insulina (SI), o conteúdo de superóxido (CS) e ativação da NADPHox foram analisados em resposta a glicose na presença ou ausência de GW (20mM). O envolvimento da NADPHox no CS induzido pelo GW foi analisado após inibição da NADPHox. O aumento da concentração de glicose paralela com aumento da SI, causa redução no CS. A presença do GW potencializa a SI em altas concentrações de glicose, aumenta o CS, e aumenta a translocação da subunidade p47phox do plasma para a membrana. Com a inibição da NADPHox o efeito do GW não ocorre. Os dados confirmam um efeito positivo do GPR40 na secreção de insulina estimulada pela glicose. O GW ativa a NADPHox resultando em um aumento do CS nas células BRIN-BD11. / BRIN-BD11, an Insulin secreting cell line, are used to study the mechanisms of glucose-stimulated insulin secretion (GSIS). These cells express GPR40, which is activated by fatty acids (FA) and potentiates GSIS. Considering that reactive oxygen species (ROS) is a signal that modulates insulin secretion (IS) induced by FA, this study aimed to investigate the involvement of GPR40 in ROS production, via NADPH oxidase (NADPHox), and in GSIS. To activate the GPR40 its agonist, GW9508 (GW), was used. IS and superoxide production (SP) were analyzed in response to increasing glucose concentrations (IGC), with or without GW (20mM). The activation of NADPHox was analyzed. The involvement of NADPHox on SP induced by GW was also evaluated using a small interference RNA or using the NADPHox inhibitor, VAS2870 (12mM). The presence of GW potentiated the IS at high glucose concentrations, together with an increased effect on SC. This increase was paralleled by an increase in the translocation of p47phox to the plasma membrane. Moreover, the inhibition of NADPHox abolished the GW9508 effect. These results show a positive effect of the GPR40 activation in GSIS. Additionally, GW9508 activates NADPHox resulting in an increase in the SC in BRIN-BD11 cells.

Ground penetrating radar (GPR) technology has existed for many decades, but it has only been in the last 20 to 30 years that it has undergone great development for use in near surface ground investigations. The early 1980's saw the first major developments in the application of GPR for pavements (i.e. engineered structures designed to carry traffic loads), and it is now an established investigation technique, with generic information included in several national standard guidance documents. Analysis of GPR data can provide information on layer depths, material condition, moisture, voiding, reinforcement and location of other features. Assessing the condition of pavements, in order to plan subsequent maintenance, is essential to allow the efficient long-term functioning of the structure and GPR has enhanced and improved the range and certainty of information that can be obtained from pavement investigations. Despite the recent establishment of the technique in pavement investigation, the current situation is one in which GPR is used routinely for pavement projects in only a minority of countries, and the specialist nature of the technique and the sometimes variable results that are obtained can mean that there is both a lack of appreciation and a lack of awareness of the potential information that GPR can provide. The fact that GPR is still a developing technique, and that many aspects of its use are specialised in their nature, means that there are also several technical aspects of GPR pavement investigations which have not been fully researched, and knowledge of the response of GPR to some material conditions has not been fully established. The overall aim of this EngD research project was to provide improved pavement investigation capabilities by enhancing the methodologies and procedures used to obtain information from GPR. Several discrete research topics were addressed through various research methods including a literature review, fieldwork investigations, experimental laboratory investigations and a review of previously collected data. The findings of the research allowed conclusions and recommendations to be made regarding improved fieldwork methodologies, enhancing information and determining material condition from previously collected GPR data, assessing the effect of pavement temperature and moisture condition on GPR data and also on managing errors and uncertainty in GPR data. During the EngD project, a number of documents and presentations have been made to publicise the findings both within the EngD sponsoring company (Jacobs) and externally, and an in-house GPR capability has been established within Jacobs as a direct result of the EngD project.

Concrete structures are susceptible to deterioration over time and it is vital to continually assess concrete structures to maintain the structural integrity and prolong the service life. In recent years there has been an increased interest in non-destructive testing of concrete, i.e. assessing the state of the concrete without causing any damage to the structure in the process. There are many different techniques that falls under the term non-destructive testing and one of these that have gained prominence during the last few years is Georadar or ground penetrating radar, often shortened as GPR. GPR is a technique where microwaves are sent into the surface of the concrete by a device, the waves will reflect back to the device when encountering interfaces of areas with different electric properties. The waves are then received by the same device indicating the internal structure of the concrete. This makes the technique an excellent way to find reinforcement bars as the electric properties of concrete and metal strongly differ. In theory though, the technique should also be able to detect other internal differences in concrete, such as voids and corrosion areas but further research is still needed in these areas. This aim of this report is to evaluate ground penetrating radar as a non-destructive technique for assessment of concrete structures. In order to do this different tests has been conducted to evaluate the general performance and usability with a literature review introducing the science behind and what conclusions other researches has reached and using a testing methodology to reach the results. The tests can in a simple way be divided into two parts, first lab tests on a slab in a controlled setting where the internal structure was known, and then two shorter field trips in order to evaluate the performance properly insitu. The results were, to some extent, ambiguous. Although it was found that GPR is an excellent method for finding and locating near-surface reinforcement it was also concluded that the results could vary significantly depending on the location. In one of the field trips the performance of the GPR technique was compared to the performance of traditional cover meter and in this case the portability of the cover meter outperformed the somewhat clunky handling of the GPR. The concrete cover measurement using post-processing of the radar data gave a rough estimate, but once again evaluation still relied on the insitu conditions and the estimate were sometimes questionable. Finding reinforcement below the first layer yielded differing results and it was concluded that further tests were needed to fully evaluate the capabilities of the technique in this regard. The conclusions of the thesis was that although the tests show some potential for the method the results expected from GPR would strongly depend on suitability of the project and experience of the user. One important limiting factor was the availability of devices. For the current project only one specific device was used, it was theorized that another GPR device could get better results depending on the purpose. Furthermore, the lack of experience was also considered to be a limiting factor that might have had an effect on the results. For future research more tests on lower reinforcement and tests on detection of deterioration were suggested. Comparative studies with other similar non-destructive techniques were also considered to be an area of possible interest.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2015-10-26T16:38:39Z No. of bitstreams: 2 Ismael da Silva Raupp_.pdf: 11785634 bytes, checksum: df9af2077289fc6b1cfb3a3a6d6a7476 (MD5) Ismael da Silva Raupp_.pdf: 11785634 bytes, checksum: df9af2077289fc6b1cfb3a3a6d6a7476 (MD5) / Made available in DSpace on 2015-10-26T16:38:39Z (GMT). No. of bitstreams: 2 Ismael da Silva Raupp_.pdf: 11785634 bytes, checksum: df9af2077289fc6b1cfb3a3a6d6a7476 (MD5) Ismael da Silva Raupp_.pdf: 11785634 bytes, checksum: df9af2077289fc6b1cfb3a3a6d6a7476 (MD5) Previous issue date: 2015-08-07 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho propôs uma pesquisa interdisciplinar entre a Geologia e a Arqueologia, buscando compreender, a partir de uma perspectiva geoarqueológica, a relação entre a evolução da Planície Costeira do Rio Grande do Sul (PCRS) e a ocupação humana pretérita na área. Nossa área de estudo foi o Litoral Norte do estado, nos limites do município de Arroio do Sal, onde utilizamos o Radar de Penetração de Solo (GPR) para adquirir perfis onde foi possível identificar feições pretéritas que indicaram configurações da planície favoráveis à ocupação humana na região. A partir dos dados coletados na PCRS foi realizada uma interpretação do possível cenário no qual antigos grupos humanos viveram, mostrando a presença de antigas lagoas e lagunas hoje colmatadas. A mesma ferramenta geofísica foi utilizada em aquisições no sambaqui Marambaia I (RS-LN-312). Com as informações obtidas, criamos um mapa indicativo de locais propensos à presença de materiais arqueológicos, esperando diminuir assim erros e custos em futuras escavações e manter a integridade do sítio. / This work is an interdisciplinary research between Geology and Archeology. It aims to understand from a geoarchaelogycal perspective the relationship between the evolution of the northern portion of the coastal plain of the Rio Grande do Sul State (PCRS) and the preterit human occupation in the area. Our study area is located within the limits of the Arroio do Sal municipality. Ground Penetrating Radar (GPR) devices were used to acquire profiles in which were identified past coastal plain features favorable to human occupation of the region. From the data collected an interpretation of the possible scenario in which ancient human groups lived was elaborated, including the presence of currently filled back barrier lakes and lagoons. The same geophysical tool was used for subsurface acquisition in the shell mound named Marambaia I (RS-LN-312). The results have allowed the elaboration of a map of places prone to the presence of archaeological materials, hence hoping to reduce errors and costs in future excavation and therefore to preserve as much as possible the site integrity.

O método Geofísico de Radar de Penetração no Solo - GPR vem contribuindo muito em estudos de zonas costeiras, sobretudo por apresentar uma resposta e uma interpretação geofísico-geológica satisfatória na grande maioria dos casos. No entanto o GPR possui algumas limitações, por utilizar de princípios físicos para sua execução algumas propriedades existentes nos materiais em subsuperfície podem causar a atenuação do sinal ou mesmo manter a onda eletromagnética confinada se igualando a uma camada guia de onda. O objetivo desse estudo é entender e inferir a partir de uma análise física e de uma interpretação geofísica-geológica quais os fatores que podem estar causando esse tipo de fenômeno. A área de estudo está localizada no Banhado do Taim uma região do extremo Sul do Brasil, no estado do Rio Grande do Sul. O dado utilizado neste estudo consta de um perfil de GPR obtido sobre um paleocanal que conectava a região da atual lagoa Mirim com o oceano Atlântico. Esse registro apresente dados excelentes de preenchimento de canais, porém na parte final do perfil esse registro é sombreado como se fosse adicionado um escudo bloqueador. Os resultados indicaram que esse bloqueio está relacionado à existência da camada guia de onda, que a mesma está associada a um tipo de ambiente lagunar. Esse ambiente está relacionado à presença de sedimentos finos, nos quais a fração de argila existente e a matéria orgânica misturada a um teor elevado de umidade contribuem para um alto valor de condutividade e baixa resistividade, resultando numa forte atenuação do sinal e aprisionamento da onda eletromagnética. / The Ground Penetrating Radar (GPR) method has contributed to studies of coastal zones, especially because it presents a response and interpretation geophysicalgeological satisfactory. However, GPR has some limitations, because it uses physical principles in its execution, and some properties in subsurface materials can cause signal attenuation or even keep the electromagnetic wave confined to a waveguide layer. The objective of this study is to understand and infer from a physical analysis and a geophysical-geological interpretation the factors that cause this phenomenon. The study area is located in Banhado do Taim (marshes), a region in southernmost Brazil, state of Rio Grande do Sul. The data used in this study consists of a GPR profile obtained on paleochannels that connected the region of the current Mirim lagoon with the Atlantic Ocean. This record shows excellent channel fill data, however, in the final part of the profile, this record is shaded as if a shield were blocking the signal. Results indicate that this blockade is related to the existence of the waveguide layer, which is associated with a type of lagoon environment. This environment is related to the presence of fine sediments, in which the clay fraction and organic matter mixed with high humidity content, which contributed to the high conductivity and low resistivity value. Result is strong signal attenuation and entrapment of the electromagnetic wave

Nesta pesquisa são apresentadas as contribuições dos métodos GPR e eletromagnético indutivo (equipamento EM-38) nos estudos de sítios arqueológicos de sambaquis costeiros Jabuticabeira II, Santa Marta IV, V, VII e VIII, e Encantada III, localizados no município de Jaguaruna, litoral centro-sul de Santa Catarina. Estes sítios são caracterizados por acúmulos de conchas carbonáticas construídos por sociedades do período pré-colonial (7,5 a 1,3 mil anos AP). Os estudos foram desenvolvidos, visando o mapeamento de artefatos de interesse arqueológico e de estruturas estratigráficas que auxiliem a compreensão do processo construtivo e funcional destes sítios. A interpretação dos resultados GPR foi apoiada nas modelagens numéricas GPR 2D e nas imagens 3D e integrada com os levantamentos EM-38, e tiveram como objetivos orientar as escavações arqueológicas. Os resultados permitiram encontrar alvos e artefatos arqueológicos, reduziram os custos no processo exploratório e preservaram o patrimônio histórico. Complementando o processo de interpretação integrada, os perfis estratigráficos e as análises granulométricas dos sedimentos provenientes dos furos de sondagens foram importantes para a definição dos ambientes de deposição onde os sambaquis estão assentados, corroborando de maneira significativa com as pesquisas em desenvolvimento no litoral de Santa Catarina. Em termos metodológicos, as antenas GPR blindadas de 200 MHz propiciaram um melhor compromisso entre a profundidade de investigação e a resolução vertical das camadas geo-arqueológicas, e a implementação da técnica de aquisição radial permitiu um mapeamento detalhado do sítio Jabuticabeira II de forma rápida, cobrindo uma grande área. Por outro lado, com o método eletromagnético indutivo (EM-38), a correção do efeito topográfico dos dados melhorou os contrastes de condutividade elétrica entre as estruturas arqueológicas e o background, permitindo assim, que os alvos pontuais, antes mascarados pela influência da topografia, fossem realçados. Com relação aos resultados geofísicos em estudos geoarqueológicos, no sambaqui Jabuticabeira II, foi possível caracterizar a geometria de uma estrutura geológica, associada a um paleo-canal e a deposição dos sedimentos em barras de pontal; mapear alvos arqueológicos e metálicos contemporâneos; traçar os limites do sítio; imagear uma camada conchífera, camadas antrópicas recentes e a profundidade do nível dágua; detectar a presença de dois sistemas deposicionais, paleolaguna e paleoduna, bem como delimitar o assentamento do sítio sobre estes ambientes por meio das informações das análises granulométricas dos sedimentos coletados nos furos de sondagens. Nos sambaquis de Santa Marta IV, V, VII e VIII, a integração dos dados GPR e EM38 permitiram o mapeamento de diversos alvos de grande importância para os estudos arqueológicos, tais como, paleofogueiras, sepultamentos e concentração de materiais cerâmicos e líticos, bem como feições geológicas, tais como, estruturação de camadas e paleotômbolos. Além disso, a redução do efeito topográfico sobre os dados de condutividade elétrica (EM-38) permitiu relacionar as regiões anômalas com um paleofogueira e uma concentração de material cerâmico. No sambaqui Encantada III, duas fortes anomalias GPR, caracterizadas por reflexões hiperbólicas, estavam associadas: i) a uma estrutura escura pontual, caracterizada como um bolsão de conchas carbonáticas; e ii) a presença de uma raiz de árvore concrecionada, que embora não seja de interesse arqueológico, é significativa, pois serve como um bom exemplo de ambiguidade na interpretação de dados geofísicos. Também foi possível delimitar o assentamento do sítio sobre os sedimentos da paleo-laguna, evidenciado pelas análises granulométricas dos sedimentos. / In this study, GPR and electromagnetic induction (EM-38 instrument) methodcontributions in coastal sambaqui archaeological sites (Jabuticabeira II, Santa Marta IV, V, VII and VIII as well as Encantada III) are presented. These sites are placed in Jaguaruna, Santa Catarina center-south coast. They are characterized by accumulation of carbonate shells built by societies in pre-colonial period (7.5 to 1.3 thousand years BP). The studies were developed aimed at mapping archaeological artifacts and stratigraphic structures that help to understand constructive and functional process of these sites. The interpretation of GPR results was supported by 2D GPR numerical modeling, 3D images and integrated with EM-38 surveys. They had as objectives to guide archaeological excavations. The results allowed finding archaeological targets and artifacts, reduced costs in exploratory process, and preserved historical heritage. Complementing integrated interpretation process, stratigraphic profiles and granulometric analysis of sediment from sounding drifts were important for defining the deposition environments where sambaquis (shell mounds) are settled, significantly supporting in developing research on Santa Catarina coast. Methodologically, 200 MHz shielded GPR antennas provided a better agreement between depth of investigation and vertical resolution of geoarchaeological layers, and the implementation of radial acquisition technique allowed a quickly detailed mapping of Jabuticabeira II site, covering a large area. Furthermore, with electromagnetic inductive method (EM-38), the topographic effect correction of data has improved the contrast in electrical conductivity between archaeological structures and background. Thus, punctual targets before masked by topography influence were highlighted. Regarding geophysical results in geoarchaeological studies, in Jabuticabeira II sambaqui, it was possible to characterize the geometry of a geological structure associated with a paleochannel and sediment deposition in point bars; to map archaeological and contemporary metal targets; to trace site boundary; to image shell layer, recent anthropic layers and water level depth; to detect the presence of two deposicional systems, paleolagoon and paleodune as well as to delimit the settlement site on these environments through information of granulometric analysis of sediments collected in sounding drifts. In Santa Marta IV, V, VII and VIII sambaquis, GPR and EM-38 data integration allowed mapping several targets of great importance for archaeological studies, such as paleofires, burials and concentration of ceramic and litic material as well as geological features, such as layer structuring and paleotombolos. Moreover, the reduction of topographic effect on electrical conductivity data (EM-38) allowed relating anomalous regions with a paleofire, and a concentration of ceramic material. In Encantada III sambaqui, two strong GPR anomalies characterized by hyperbolic reflections were associated with: i) a dark punctual structure, characterized as a pocket of shell carbonate, and ii) the presence of a concretion tree root that is significant, despite not of archaeological interest, because it serves as a good example of ambiguity in geophysical data interpretation. It was also possible to delimit the settlement site on paleolagoon sediments, evidenced by granulometric analysis of sediments.

.El georradar es una herramienta cada vez más utilizada en diferentes ámbitos geológicos, medioambientales y de Ingeniería Civil, así como en estudios de caracterización de yacimientos arqueológicos y de diagnóstico de daños en edificios del patrimonio histórico y cultural.En esta tesis se abordan aspectos metodológicos de calibración de la instrumentación y de caracterización de las propiedades electromagnéticas que rigen la propagación y atenuación de ondas electromagnéticas en los suelos. Por otra parte, se estudian aplicaciones en monumentos históricos, yacimientos arqueológicos y diagnóstico de daños.Concretamente, en esta tesis se calibran cuatro antenas, caracterizadas por su frecuencia central de emisión: 200, 500, 900 y 1000 MHz. En cada caso se obtiene la señal sólo con el ruido interno de la antena (sin reflexiones). De dicho ruido, el de mayor amplitud es la señal inicial; su longitud determina la distancia mínima entre la antena y la primera superficie reflectora del medio para que no se produzca acoplamiento entre la reflexión y la señal inicial. Se analiza también el origen de tiempos de la señal para cada antena (cero de la antena) y se estudia la atenuación producida en la señal durante su propagación por el aire (medio no absorbente), que, por lo tanto, se produce por expansión geométrica, siendo la amplitud inversamente proporcional a la distancia. Se ensaya un procedimiento para caracterizar medios electromagnéticamente, relacionando sus propiedades físicas: granulometría, peso específico, porosidad y saturación, con la conductividad, la permitividad y la frecuencia. Se analizan tres medios formados por un mismo material, modificándose tres propiedades: peso específico aparente, compactación y saturación. En cada caso se obtiene la velocidad de propagación, la permitividad dieléctrica, el espectro de frecuencias y la atenuación. Al aumentar la saturación la velocidad es menor, se produce un desplazamiento hacia las bajas frecuencias, se estrecha el ancho de banda y la atenuación por absorción aumenta. Asimismo se analizan y discuten diferentes métodos para obtener la velocidad: tiempos y espesores conocidos, análisis de hipérbolas, comparación de amplitudes, dromocrónicas de un CMP, modelos geotécnicos, contraste de capacitancias y perfiles de estratigrafía conocida. Los mejores resultados obtenidos son los que proporcionan los ensayos de laboratorio con muestras de espesor conocido y el análisis de reflexiones hiperbólicas. De la comparación de los resultados obtenidos con los que proporciona la literatura se deduce la conveniencia de realizar una caracterización en laboratorio en casos que requieran una resolución fina de las anomalías superficiales o de profundidad intermedia.Relacionados con estas investigaciones (caracterización de medios y calibración de antenas), se han ejecutado y estudiado aplicaciones a casos reales que han permitido resolver problemas prácticos y, al mismo tiempo, han permitido también observar las ventajas de la aplicación de los avances de la investigación, así como avanzar en las técnicas de identificación y cancelación de ruidos introducidos por reflexiones externas o múltiples. Los principales casos resueltos hacen referencia a: control de intervenciones de restauración y rehabilitación en monumentos o en construcciones históricas (casos del teatro romano de Sagunto y de los puentes góticos sobre el río Turia), estudio de daños en edificios del patrimonio cultural (casos de la Catedral de Valencia e Iglesia de San Jorge de Paiporta), caracterización de yacimientos arqueológicos (casos del subsuelo de la Catedral de Valencia, de la Iglesia de San Jorge y de la fortaleza romana y convento en Alcántara).Algunos resultados y casos relevantes se sintetizan en fichas monográficas que presentan en forma esquemática las claves referentes al problema estudiado, lugar y herramienta empleada. Estas fichas serán de gran utilidad en el estudio de casos similares y se espera que constituyan el inicio de un catálogo de casos y soluciones. / The Ground-Penetrating Radar (GPR) is a tool more and more used in different geological, Environmental Engineering and Civil Engineering research, as well as in studies of characterisation of archaeological locations and in the diagnosis of the damages in buildings of the historical and cultural heritage. In this thesis, methodological aspects of calibration of the instrumentation are performed. Also, methodological aspects of the soils characterisation by using its electromagnetic properties are analysed. These properties govern the propagation and attenuation of electromagnetic waves in the soils. On the other hand, several applications to the study of historical monuments, archaeological locations and diagnosis of damages are investigated.Particularly, in this thesis four antennae are gauged. These antennae are characterised by their central frequency of emission: 200, 500, 900 and 1000 MHz. For each case, the internal noise of the antenna (radar record without reflections) is obtained;the highest noise is the initial signal (usually the direct wave); its longitude determines the minimum distance between the antenna and the first reflective surface to obtain a radar data where the two events (direct wave and reflected wave) are clearly separated. It is also analysed the time origin of the traces for each antenna (zero of the antenna). The attenuation of the traces during the wave propagation in the air (non-absorbent medium) is also studied. Therefore, in that case, the attenuation is caused by the geometric spreading, and the wave amplitude is inversely proportional to the distance. A procedure is tested to characterise media using its electromagnetic properties: the conductivity, the permitivity and the frequency, relating them with its physical properties: grain size, specific weight, porosity and saturation. Three different media are analysed, formed by the same solid material and modifying three physical properties: the apparent specific weight, the compactation (and, therefore, the porosity) and the saturation. In each case, the wave propagation velocity, the dielectric permitivity, the spectrum of frequencies and the attenuation are obtained. When the saturation increases, the velocity decreases, a displacement takes place toward the low frequencies, the band width is narrowed and the attenuation caused by absorption increases. In addition, different methods to obtain the wave velocity are analysed and discussed: times and well-known thickness, analysis of hyperbolas, comparison of amplitude, radar records obtained in a CMP, geotechnical models, contrast of capacitancy and profiles of well-known stratigraphy. The best results are obtained from the laboratory measurements using samples of well-known thickness and from the analysis of hyperbolic reflections. Comparison of these results and the values provide by the literature is performed. This comparison shows the convenience of carrying out a characterisation of the medium in laboratory in the cases when a fine resolution of the superficial anomalies or of intermediate depth is required. Related with these investigations (characterisation of means and calibration of antennas), several applications to real cases have been performed and studied. These applications have allowed to solve practical problems and, at the same time, to observe the advantages of applying the advances of the investigation, as well as to make progress in the identification techniques and suppression of noise introduced by external or multiple reflections. The main cases resolved make reference to: control of restoration, interventions and rehabilitation in monuments or in historical buildings (cases of the Roman theatre of Sagunto and the Gothic bridges on the river Turia), study of damages in buildings of the cultural heritage (cases of the Cathedral of Valencia and the Church of San Jorge, in Paiporta), characterisation of archaeological locations (cases of the underground of the Cathedral of Valencia, Church of San Jorge and the Roman fortress and the convent in Alcántara). Some results and the best cases cases are synthesised in monographic cards. These cards present, in schematic form, all the information about the studied problem, the emplacement and the used tool. These cards will be very useful in the study of similar cases, and it is expected that they constitute the beginning of a catalogue of cases and solutions.

This Master Thesis examines the possibility to apply a magnetometer developed by the Ångstöm space technology center to a small magnetic ground penetrating radar system with dimension in the order of one dm³. The magnetometer is broadband (DC-1GHz) and miniaturized. Loop antennas are used to transmit the signal.    A series of experiments have been performed in order to characterize the system, mainly examining the ability to determine distance to a target, using continuous sine wave signals and pulse trains. Standing wave patterns are formed between antenna and target and can be used for determining distance in the continuous case. When using a pulse train, the echo from the target could not be resolved using the current experiment set up, distance could therefore not be determined.

This thesis presents an analysis of the behavior of an equiangular spiral antenna using a mixture of numerical and measurement techniques. The antenna is studied as an isolated element and as a part of a spiral-based ground-penetrating radar (GPR) detection system. The numerical modeling was based on the parallelized finite-difference time-domain method and the model was validated by comparison with a prototype antenna and detection system. The intention is to isolate the effect of varying different geometrical parameters that define the spiral element or the spiral GPR system. With some notion of each parameter's effect, systems that use the spiral antenna can be designed more easily. The analysis of the spiral antenna in isolation provides a set of design graphs for the antenna. A set of design graphs are constructed that allow one to better understand the effect of the chosen dielectric substrate on the characteristic impedance of the antennas. A second set of design graphs give very specific data about the lower cut-off frequency possible for the antennas given a requirement on its minimum boresight gain, axial ratio, or voltage standing-wave ratio when matched with an appropriate transmission line. The analysis of the spiral antenna in the context of a detection system provides information on the effect of the ground on the GPR system and to what extent the circular polarization properties of the spiral antenna play a role in GPR. It is shown that a spiral antenna used in a monostatic radar configuration will reject a symmetric scatterer well into the near-field. The importance of a resistive loading to the spiral arms is demonstrated for this rejection to be optimal. In addition, it is shown that increasing the dielectric constant of the ground narrows the pattern and polarization properties, making the antenna more directive towards boresight when the spiral antennas radiate into a flat ground. In addition to this work, a method for reducing the truncation error when calculating the planewave spectrum of an antenna is described.