Orientador: Luís Eduardo Evangelista de Araujo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-29T14:34:13Z (GMT). No. of bitstreams: 1 FernandezApolinario_Ulices_D.pdf: 32632596 bytes, checksum: 913293ad92a80bba8b449b4814411610 (MD5) Previous issue date: 2015 / Resumo: Nesta tese, propomos, descrevemos e desenvolvemos um novo mecanismo de clonagem de imagens ópticas baseado no efeito atômico coerente da absorção induzida eletromagneticamente ("EIA"). Estudamos experimentalmente a transferência de uma imagem impressa em um feixe forte de acoplamento para um feixe fraco de prova ressonante em um sistema atômico de rubídio de quatro níveis do tipo N degenerado. Nos experimentos, uma imagem bidimensional correspondente a um padrão de linhas horizontais é aplicada ao feixe de acoplamento e transferida para um feixe de prova, de mesma frequência mas polarização ortogonal ao laser de acoplamento. A clonagem de imagem é estudada em função da potência, dessintonia e grau de coerência espacial do feixe de acoplamento. Nós mostramos experimentalmente que o feixe de prova clonado que carrega a imagem é transmitido sem a difração usual. Apresentamos um modelo teórico, para o caso de um feixe de acoplamento espacialmente coerente, que prevê que as características transversais do feixe de acoplamento são transferidas para o feixe de prova de maneira eficiente, apesar da imagem de controle sofrer distorções devido a difração durante a propagação. De fato, as imagens clonadas podem ser muito melhores do que as imagens de acoplamento originais, com estruturas reduzidas em tamanho por aproximadamente um fator de 2. Experimentalmente, verificamos que quanto menor o grau de coerência da luz, melhor é a imagem clonada quando comparada com a imagem de acoplamento a uma mesma distância de propagação. Uma comparação com outras técnicas de clonagem estudadas na literatura, com luz espacialmente coerente, mostra que o nosso mecanismo apresenta um desempenho similar a elas, com uma transmissão máxima da imagem clonada pelo vapor atômico de aproximadamente 10% / Abstract: In this thesis, we propose, describe and develop a new optical imaging cloning mechanism based on the coherent atomic effect of electromagnetically induced absorption ("EIA"). We experimentally study the transfer of an image imprinted onto a strong coupling beam to a resonant weak probe beam in a rubidium atomic system in a degenerate four-level N configuration. In the experiments, a two-dimensional image corresponding to a pattern of horizontal lines is imprinted onto the coupling beam and transferred to a probe beam of the same frequency, but with orthogonal polarization to the coupling laser. Image cloning is studied as a function of power, detuning and the degree of spatial coherence of the coupling beam. We show experimentally that the cloned probe beam carrying the image is transmitted without the usual diffraction. We present a theoretical model, for the case of a fully spatially-coherent coupling beam, that predicts that the transverse characteristics of the coupling beam are efficiently transferred to the probe beam, in spite of distortions of the control image due to diffraction during propagation. Indeed, the cloned images can be much better than the original images of the coupling beam, with structures reduced in size by approximately a factor of 2. Experimentally, we found that the lower the degree of coherence of the coupling light, the better the cloned image compared to the coupling image for the same propagation distance. A comparison with other cloning techniques studied in the literature, with spatally coherent light, shows that our mechanism has a similar performance, with a maximum cloned image transmission by the atomic vapor of approximately 10% / Doutorado / Física / Doutor em Ciências / 153079/2010 / 0554/15 / CNPQ / Funcamp

Runion is a protohistoric Native American village located on the floodplain of the Nolichucky River in western Washington County. Previous archaeological excavations and radiocarbon dates suggest that the village was occupied during the mid-16th to mid-17th century. The Nolichucky River, in contrast, has been flowing through the area for millennia. Geophysical surveys are used to image the subsurface non-invasively, without disturbing protected land and/or organisms. Preliminary geophysical data collected at Runion include ground penetrating radar (GPR), electromagnetic induction (EMI), and magnetometry. These data show a linear feature surrounding the protohistoric village. Given its placement around the margins of the village, the feature could be interpreted as a fortification ditch, which is often paired with a palisade wall to defend a village from attack. The feature is also consistent with typical meandering floodplain stratigraphy, where sections of channel are often abandoned to form oxbow lakes. Over time these abandoned channels fill in and are called paleochannels. Each geophysical method measures the properties and characteristics of the linear feature, a presumed paleochannel. GPR sends electromagnetic radar waves into the ground, which reflect off different subsurface layers and are recorded as radargrams. Magnetometry measures subtle changes in earth magnetism, including the magnetization of rocks, soils, and/or ferrous objects. EMI systems transmit low frequency electromagnetic waves to measure both electrical conductivity (EC) and magnetic susceptibility (MS). Each of these instruments are used to collect data in transects and then processed to produce profiles, maps and, in the case of GPR, three-dimensional datasets of the subsurface. It is anticipated that GPR will reveal details about the stratigraphy of the linear feature. Magnetic, EC, and MS measurements will further help to interpret the GPR data by distinguishing between different types of sediments. These data may show if the feature is a paleochannel or a ditch excavated into older stratigraphic layers by village inhabitants for fortification. Ultimately, the feature will be tested with soil cores to study the sediments directly. At this preliminary stage the feature is interpreted to be a paleochannel. The stratigraphic layers revealed by GPR show a broad depression with stratigraphic layers characteristic of a paleochannel. In addition, magnetic readings are anomalously low on the eastern margin (closer to the modern river channel) and high on the western margin. This could indicate paired point bar sands and paleochannel fill, respectively. This interpretation is still tentative, however, because we have not yet integrated the EMI data, extracted soil cores, or dated the feature. Radiocarbon dates might help determine the relative age of the feature if organic carbon is present. In conclusion, preliminary data currently suggests that the structure is geological rather than archaeological. In the coming months we will collect more GPR data with different frequency GPR antennas, integrate the EMI data, and test the findings by extracting soil cores and reconstructing the stratigraphy.

Electromagnetic induction (EMI) has been used in archaeology for decades, but still lags in use and development when compared to magnetometry and ground-penetrating radar. While it has become more popular than electrical resistivity area survey, it is now less commonly used than electrical resistivity tomography. The EMI method is likely underutilized due to drift problems and a lack of multi-sensor, vehicle-towed systems capable of rapid, high-density data collection. In this article we demonstrate not only the effectiveness of EMI survey, but a case where entire villages would have remained undetected without it. At the Singer-Hieronymus Site in central Kentucky, USA, a vehicle-towed frequency domain EMI survey detected the location of plazas, residential areas, and trash disposal areas across multiple Fort Ancient villages that contained both intact and heavily disturbed deposits. Additionally, three new villages were revealed. Through this process, we discovered how Fort Ancient village dynamics may be studied through a geophysical investigation of village shape, size, and spatial organization.

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Electromagnetic induction (EMI) has been used in archaeology for decades, but still lags in use and development when compared to magnetometry and ground-penetrating radar. While it has become more popular than electrical resistivity area survey, it is now less commonly used than electrical resistivity tomography. The EMI method is likely underutilized due to drift problems and a lack of multi-sensor, vehicle-towed systems capable of rapid, high-density data collection. In this article we demonstrate not only the effectiveness of EMI survey, but a case where entire villages would have remained undetected without it. At the Singer-Hieronymus Site in central Kentucky, USA, a vehicle-towed frequency domain EMI survey detected the location of plazas, residential areas, and trash disposal areas across multiple Fort Ancient villages that contained both intact and heavily disturbed deposits. Additionally, three new villages were revealed. Through this process, we discovered how Fort Ancient village dynamics may be studied through a geophysical investigation of village shape, size, and spatial organization.

No / Searching for and mapping the physical extent of unmarked graves using geophysical techniques has proven difficult in many cases. The success of individual geophysical techniques for detecting graves depends on a site-by-site basis. Significantly, detection of graves often results from measured contrasts that are linked to the background soils rather than the type of archaeological feature associated with the grave. It is evident that investigation of buried remains should be considered within a 3D space as the variation in burial environment can be extremely varied through the grave. Within this paper, we demonstrate the need for a multi-method survey strategy to investigate unmarked graves, as applied at a "planned" but unmarked pauper's cemetery. The outcome from this case study provides new insights into the strategy that is required at such sites. Perhaps the most significant conclusion is that unmarked graves are best understood in terms of characterization rather than identification. In this paper, we argue for a methodological approach that, while following the current trends to use multiple techniques, is fundamentally dependent on a structured approach to the analysis of the data. The ramifications of this case study illustrate the necessity of an integrated strategy to provide a more holistic understanding of unmarked graves that may help aid in management of these unseen but important aspects of our heritage. It is concluded that the search for graves is still a current debate and one that will be solved by methodological rather than technique-based arguments.

Electromagnetic induction (EM) methods have been utilised in a recent surge of archaeological applications across continental Europe, Ireland and Scandinavia. Development of multi-exploration depth instruments and improvements to instrument stability have improved its reputation as an effective method for mapping archaeological remains. Despite these advances, EM methods are comparatively lacking in rigour when for British sites. Through a structured scheme of experimental analysis and fieldwork, this thesis develops an understanding of the responses of EM instruments over a range of British archaeology, including earthworks, field systems, burials, modern remains, and a Cistercian abbey; the results of which demonstrate its effective over a diversity of environments. The impact of instrument-based issues on the collected measurements was quantified through a scheme of experiments targeting instrument drift, calibration and elevation. Dedicated instrument operation and processing workflows were developed based on the collective field and experimental results, which recommend best practice guidelines for improving the quality and accuracy of collected data. The link between instrument measurements and buried archaeology was further developed through a structured analysis of the EM datasets with complementary earth resistance and magnetic results. The integration of the EM, earth resistance and magnetic datasets was utilised to develop an enhanced archaeological characterisation of subsurface features. While the earth resistance and magnetic methods generally responded to different aspects of the buried archaeology, the EM surveys were able to detect a range of responses evident in the results of the former methods. Therefore, the role of EM methods within this characterisation are shown to “bridge the gap” between the earth resistance and magnetic methods, while providing a comprehensive characterisation of the remains in their own right. / The supplementary material files from Appendix 2 are not available online.

In the last decade, we have seen an increasing interest in the designing of interactive technology that is limited in energy usage to our bodily capabilities. This field is commonly referred to as Human-Power Interaction (HPI). The aim of HPI is to create battery-free devices that are powered solely from human interactions. Therefore, it is important that power generation and interactivity are aligned and not separated tasks. In this paper, a novel way of providing human power to interactive devices has been investigated using electromagnetic induction. The focus has been to explore and play with the fundamental principles of electromagnetic induction with the intention of evaluating its potential as a new type of interactive power generation. With the help of a physical prototype and an application to demonstrate its capabilities, the results show that electromagnetic induction could potentially be considered as a relatively easy way to build human-powered sources for interactive devices using this principle. / Under det senaste decenniet har vi sett ett ökande intresse för utformningen av interaktiv teknik som är begränsad i energianvändningen till det av våra kroppsliga förmågor. Detta fält kallas vanligen Human-Power Interaction (HPI). Målet med HPI är att skapa batterifria enheter som drivs enbart från mänskliga interaktioner. Därför är det viktigt att kraftproduktion och interaktivitet är anpassade till varandra och inte separerade aktiviteter. I denna rapport har ett nytt sätt att tillhandahålla mänsklig kraft till interaktiva enheter undersökts med hjälp av elektromagnetisk induktion. Fokus har varit att utforska och leka med de grundläggande principerna för elektromagnetisk induktion i avsikt att utvärdera dess potential som en ny typ av interaktiv kraftproduktion. Med hjälp av en fysisk prototyp och en tillämpning för att demonstrera dess förmåga, visar resultaten att elektromagnetisk induktion potentiellt kan ses som ett relativt enkelt sätt att bygga människodrivna källor för interaktiva enheter med denna princip.

Vacant lots in cities and surrounding urban areas can potentially be used for stormwater management because they are pervious. However, the extent to which vacant lots provide pervious cover to increase infiltration and reduce stormflow is poorly understood. The goal of this study was to develop faster methods for monitoring stormwater infiltration to improve characterization of heterogeneous urban systems. Geophysical techniques are capable of mapping and characterizing subsurface materials, but are often limited by time and sensitivity constraints. In this study, the infiltration characteristics of a vacant lot created by the demolition of a house was characterized using a series of modeling, field and lab experiments. Site characterization under background conditions with an EM Profiler was used to map zones of different fill materials. Three zones were identified in the study site: grass area, driveway area, and a former house area. Transient soil moisture conditions were monitored during irrigation tests using two geophysical methods (electrical resistivity tomography [ERT] and electromagnetic induction [EM]) to evaluate method sensitivity and differences between the three zones. ERT proved more sensitive than EM profiling at detecting changes in the three zones. Soil moisture changes in the driveway area were particularly difficult to detect using EM. The EM Profiler showed a reduction rather than increase in conductivity at the start of irrigation and storms, which was attributed to flushing of high conductivity pore fluids by dilute irrigation or rain water. This explanation was supported using Archie’s Law to model the response of apparent conductivity under highly conductive pore fluid conditions. The EM Profiler was also used under natural precipitation conditions to quickly monitor areas too large for the ERT to reasonably survey. The results suggested that EM instrument drift needs to be corrected to make the method more sensitive. It was difficult to detect differences in hydrologic characterization between areas of the vacant lot using traditional soil point measurements because of the inherent spatial variability. The most useful point measurement was soil moisture loggers. Data from soil moisture loggers was used to parameterize the model; in addition, the soil moisture loggers showed a slow drying period. By combining the EM Profiler method with soil moisture data and applying corrections for drift, some improvement in sensitivity might be achieved. Quantitative characterization of fill material was shown by ERT, which detected more heterogeneous infiltration in the area of the former house than in the grass area. / Geology

This dissertation focuses on two different types of responses of Earth; that is, seismic and electromagnetic, and aims to better understand Earth processes at a wider range of scales than those conventional approaches offer. Electromagnetic responses resulting from the subsurface diffusion of applied electromagnetic fields through heterogeneous geoelectrical structures are utilized to characterize the underlying geology. Geology exhibits multiscale hierarchical structure which brought about by almost all geological processes operating across multiple length scales and the relationship between multiscale electrical properties of underlying geology and the observed electromagnetic response has not yet been fully understood. To quantify this relationship, the electromagnetic responses of textured and spatially correlated, stochastic geologic media are herein presented. The modelling results demonstrate that the resulting electromagnetic responses present a power law distribution, rather than a smooth response polluted with random, incoherent noise as commonly assumed; moreover, they are examples of fractional Brownian motion. Furthermore, the results indicate that the fractal behavior of electromagnetic responses is correlated with the degree of the spatial correlation, the contrasts in ground electrical conductivity, and the preferred orientation of small-scale heterogeneity. In addition, these inferences are also supported by the observed electromagnetic responses from a fault zone comprising different lithological units and varying wavelengths of geologic heterogeneity. Seismic signals generated by aftershocks are generally recorded by local aftershock networks consisted of insufficient number of stations which result in strongly spatially-aliased aftershock data. This limits aftershock detections and locations at smaller magnitudes. Following the 23 August 2011 Mineral, Virginia earthquake, to drastically reduce spatial aliasing, a temporary dense array (AIDA) consisting of ~200 stations at 200-400 m spacing was deployed near the epicenter to record the 12 days of the aftershocks. The backprojection imaging method is applied to the entire AIDA dataset to detect and locate aftershocks. The method takes advantage of staking of many seismograms and improves the signal-to-noise ratio for detection. The catalog obtained from the co-deployed, unusually large temporal traditional network of 36 stations enabled a quantitative comparison. The aftershock catalog derived from the dense AIDA array and the backprojection indicates event detection an order of magnitude smaller including events as small as M–1.8. The catalog is complete to magnitude –1.0 while the traditional network catalog was complete to M–0.27 for the same time period. The AIDA backprojection catalog indicate the same major patterns of seismicity in the epicentral region, but additional details are revealed indicating a more complex fault zone and a new shallow cluster. The b-value or the temporal decay constant were not changed by inclusion of the small events; however, they are different for two completeness periods and are different at shallow depth than greater depth. / Ph. D.