Dissertations / Theses: 'Gravimetri'

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Purpurovič, Janina. "Antrosios klasės gravimetrinių matavimų analizė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120723_102357-23012.

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Baigiamajame magistro darbe atlikta Lietuvos ir Lenkijos gravimetrinių tinklų analizė. Apžvelgta IGSN 71 sunkio sistemos perdavimo metodika, išnagrinėtas gravimetrinių tinklų tikslumas. Pateikta informacija apie naujausią automatinį gravimetrą Scintrex CG-5, atlikta Lietuvos antrosios klasės gravimetrinio tinklo sudarymo metodikos detali analizė. Sudaryta gravimetrinių matavimų duomenų bazė, kuri gali būti naudojama gravimetrinių matavimų duomenų analizei. Panaudojant antrosios klasės gravimetrinio tinklo matavimų gravimetrais Scintrex CG-5 duomenis, atlikti, sunkio pagreičio tikslumo priklausomybės nuo matavimų skaičiaus punkte, tyrimai. Darbe gauti tyrimų rezultatai gali būti panaudoti tobulinant matavimų gravimetrais Scintrex CG -5 metodiką. Darbą sudaro 6 dalys: įvadas, 4 skyriai, išvados, literatūros sąrašas. Darbo apimtis – 98 p. , 56 iliustr., 22 lent., 28 bibliografiniai šaltiniai.
Thesis carried out in Lithuania and Poland, the gravimetric analysis of the network.Reviewed in IGSN 71gravity system of transmission methods, examined the accuracy of gravimetric networks. The information on the latest automatic gravimeter Scintrex CG-5, made second-class Lithuanian gravimetric network of methodology on a detailed analysis. Done gravimetric measurement database that can be used for gravimetric measurement data analysis. Using a second-class gravimeters gravimetric network Scintrex CG-5 data, perform, acceleration of gravity accuracy dependence on the number of measurements point out. We obtain the results can be used to improve measurement gravimeters Scintrex CG -5 methodology. The work consists of six parts: introduction, four sections, conclusions and the list of literature. Working volume - 98 pages, 56 drawings, 25 tables. The list of literature includes 28 bibliographical sources.

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Jensen, Mai-Britt Mose. "Geophysical tools for prognosis of deformation in hardrock environments." Doctoral thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25779.

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Underground mining of the Kiirunavaara iron mineralization is causing large-scale deformation of the hangingwall of the orebody. To understand and possibly predict future deformation, a structural model of the hanging wall and a good understanding of the petrophysical and mechanical properties of the constituent rocks is necessary. This thesis presents results from the study of Anisotropy of Magnetic Susceptibility (AMS), magneto-mineralogy, fracture frequency (F/m), rock quality (RQD), rock strength (Point Load) and P-wave velocity and anisotropy of the rocks from the hanging wall, as well as seismic reflection surveying and gravity modelling. The results are combined into a structural model of the hanging wall and further used for analysis of the correlation between petrophysical and rock mechanical parameters.In total, 76 samples from 12 outcrops and 295 samples from three drillcores in the hanging wall have been included in the AMS study. Axial and diametrical P-wave velocity was measured on 25 water-saturated samples and 156 samples were used for the Point Load tests. F/m and RQD data for the drillcores already existed. The drillcores are located along the eastern end of the seismic profiles and consist of both crystalline and sedimentary rocks.A high degree of magnetic anisotropy observed in the crystalline rocks indicates a low degree of metamorphism. AMS data also indicates the presence of a magnetic foliation in the rocks. The dip of the magnetic foliation plane (F) and the degree of magnetic anisotropy (Pj) measured in samples from outcrops was plotted as iso-maps and shows that both F and Pj decreases towards the east, which was confirmed by data from the drillcores. The decrease in both parameters is primarily a reflection of a change in rock type, but is also changing within the crystalline rock sequence.A good correlation (r > 0.6) between Pj, and F and RQD, and F and F/m was observed in one drillcore for both crystalline and sedimentary rocks; and between the shape parameter (T) and F/m in crystalline rock in another drillcore. This suggests the AMS parameter may be used as an indicator of rock mechanical properties. AMS data was also correlated to joint strike orientations and it was concluded that AMS can also be used to predict joint orientation.Two parallel reflection seismic profiles were shot within the town of Kiruna i order to locate deformation zones and lithological boundaries in the hangingwall. No deformation zones were found, but five seismic reflectors corresponding to five lithological boundaries were located, and their strike and dip calculated. The result of the seismic survey was used to constrain the gravity model, as was density measurements of 230 samples from the drillcores. The gravity model has a depth of three km, and indicates that the crystalline rock in the hanging wall can be separated into two parallel N-S trending blocks.
Godkänd; 2011; 20111021 (maimos); DISPUTATION Ämnesområde: Tillämpad geofysik/Applied Geophysics Opponent: PhD Satu Mertanen, Geological Survey of Finland, Åbo Ordförande: Professor Sten-Åke Elming, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Måndag den 19 december 2011, kl 10.00 Plats: F531, Luleå tekniska universitet

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Constantino, Renata Regina. "Utilização de dados gravimétricos derivados de altimetria por satélite e geofísica marinha no estudo de estruturas do embasamento na região da Bacia de Santos, SP." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/14/14132/tde-04062018-163733/.

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O embasamento oceânico representa a situação tectônica de uma determinada área e seu conhecimento é crucial em estudos que visam explorar o fundo marinho. Devido à alta taxa de sedimentação, principalmente em bacias oceânicas, a topografia do embasamento é mascarada e suas estruturas podem estar enterradas, inacessíveis à observação direta. Este trabalho visa estimar a profundidade do embasamento na região da Bacia de Santos a partir de uma análise combinada de dados gravimétricos obtidos a partir de altimetria por satélite e gravimetria marinha, dados batimétricos e modelo de espessura sedimentar de bancos de dados internacionais e dados de espessura crustal disponíveis na região. Na primeira etapa do trabalho foi calculado o efeito do pacote sedimentar no sinal gravimétrico na Bacia de Santos e a profundidade da Interface Crosta Manto (ICM) foi modelada a partir de inversão gravimétrica com vínculos. Na etapa seguinte, a confiabilidade dos modelos obtidos foi testada através de análise flexural. Os dados de profundidade da ICM flexural e gravimétrica se mostraram em concordância, sinalizando a adequação de seu uso na próxima etapa do trabalho. O efeito gravimétrico da ICM encontrada por análise flexural e o efeito gravimétrico dos sedimentos foram então calculados e subtraídos da anomalia Bouguer original. O campo residual assim obtido, que se admite representar as feições topográficas do embasamento, foi invertido na última etapa do trabalho, fornecendo informações que mostram um embasamento com feições topográficas de até 700m em certas regiões isoladas. Este embasamento gravimétrico pode, dentro de suas restrições, oferecer importantes subsídios para a elaboração de modelos genéticos e tectônicos de interesse exploratório na região.
The ocean basement represents the tectonic situation of an specific area and their knowledge is crucial in studies aimed at exploring the seabed. Due to the high sedimentation rate, especially in ocean basins, the topography of the basement is masked and their structures can be buried, inaccessible to direct observation. This paper aims to estimate the depth of the basement in the region of the Santos Basin from a combined analysis of gravity data obtained from satellite altimetry and marine gravimetry, bathymetric data and sediment thickness from international data banks and crustal thickness data available in the region. In the first step of the work it was calculated the gravity effect of sediments in Santos Basin and the Crustal Mantle Interface (CMI) was modeled from constrained gravity inversion. In the next step, the reliability of the models obtained was tested by flexural analysis. The flexural and gravity CMI proved to be in agreement, indicating the appropriateness of its use in the next stage of work. The gravity effect of Flexural CMI and the gravity effect of sediments were then calculated and subtracted from the original Bouguer anomaly. The residual field thus obtained, which is assumed to represent the topographical features of the basement, was inverted in the last step of the work, providing information that show a basement with features of up to 700min some isolated regions. This gravimetric basement may, within its restrictions, offer important insights for the development of genetic and tectonic models off exploration interest in the region.

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Castro, Júnior Carlos Alberto Corrêa e. "Arcabouço gravimétrico brasileiro e o meio ambiente: possibilidades e perspectivas." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8460.

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Geodesy, one of the strands that compose the Geosciences, deals with the study of Earth’s gravity shape, dimensions and field, besides providing the reference infrastructure for social and economic development throughout the planet In Brazil, the geodetic infrastructure has been developed over time through the implementation of high precision planialtimetric and gravimetric networks. In recent years, Geodesy has relied on satellite technologies to provide fast, precise and accurate positioning that allows considering the movements and deformations of global lithospheric plates. This thesis refers to the synergy between the national geodetic infrastructure and some current environmental issues. Thus, besides exploring Geodesy minutiae, the first objective was to evaluate the hypothesis that, in the most developed regions of Brazil, the gravimetric network acts as a consolidated infrastructure for the implementation of other Engineering infrastructures; on the other hand, in regions that are less developed and difficult to access, gravimetric networks evolve as infrastructure demands arise. The evaluation of this hypothesis involved the analysis of Brazilian gravimetric network distribution and its spatial and statistical relation to the Human Development Index and the population distribution. The results confirmed that in Brazil there is an correlation between spatial coverage of the gravimetric network and the Human Development Index. In the North region there is a deficiency in gravimetric network coverage, explained by precarious socioeconomic development, access difficulties, and large tracts of protected land. The obtained results also demonstrated that the national geoidal model resultant from gravimetric network MAPGEO2015 serves 89.72% of Brazilian population. Another evaluated hypothesis is that due to the large proportion of Brazilian hydrographic regions and to the number of installed active stations of SIRGAS network in part of the national territory, the association between SIRGAS stations altimetric data and the amount of water stored underground, detected by GRACE satellite system, occurs precariously. The evaluation of this hypothesis involved the correlation between altitude variation data from SIRGAS active stations and GRACE satellite system data. The results confirmed that in some of Brazilian hydrographic regions a statistical correlation was found between the altimetric variation of SIRGAS network and GRACE data. The results suggest that densification of active stations network can provide a hydrological monitoring system of fundamental importance in extreme climatic events, such as those that produce water supply crises or floods. In this work, a new geoidal model for state of Goiás, MODGEO-GO, was also proposed, based on new in loco surveys that led to a densification of Goiás gravimetric network. MODGEO-GO can assist more effectively planning and implementing major infrastructure works necessary for Goiás development. Finally, the global interpolation model with local effect, called Thin Plate Spline, was evaluated with MAPGEO2105 data. The results showed great potential of this interpolator, which can be adopted in future modeling of geoidal surfaces in Brazil.
A Geodesia, uma das vertentes que compõe as Geociências, se ocupa do estudo da forma, dimensões e campo da gravidade terrestre, além de oferecer a infraestrutura de referência ao desenvolvimento social e econômico em todo o planeta. No Brasil, a infraestrutura geodésica vem se desenvolvendo ao longo do tempo por meio da implantação de redes, planialtimétricas e gravimétricas, de alta precisão. Nos últimos anos a Geodesia conta com as tecnologias satelitárias para propiciar posicionamentos rápidos, precisos e acurados, que permitem considerar os movimentos e deformações das placas litosféricas globais. Esta tese trata da sinergia entre a infraestrutura geodésica nacional e algumas questões ambientais da atualidade. Assim, além de esmiuçar detalhes da Geodésia, teve como primeiro objetivo avaliar a hipótese de que, nas regiões mais desenvolvidas do Brasil, a rede gravimétrica atua como infraestrutura consolidada para a implementação de outras infraestruturas de Engenharia; em contrapartida, nas regiões menos desenvolvidas e de difícil acesso, as redes gravimétricas evoluem conforme as demandas por infraestrutura surgem. A avaliação dessa hipótese envolveu a análise da distribuição da rede gravimétrica brasileira e sua relação espacial e estatística com o Índice de Desenvolvimento Humano e a distribuição da população. Os resultados obtidos confirmaram que, no Brasil, há uma correlação entre a cobertura espacial da rede gravimétrica e o Índice de Desenvolvimento Humano. Na região Norte há uma deficiência na cobertura da rede gravimétrica, explicada pelo desenvolvimento socioeconômico precário, dificuldades de acesso, e por grandes extensões de terras protegidas. Os resultados obtidos demonstraram, ainda, que o modelo geoidal nacional resultante da rede gravimétrica, MAPGEO2015, atende a 89,72% da população brasileira. Outra hipótese avaliada é a de que, devido às grandes dimensões das regiões hidrográficas brasileiras e à quantidade de estações ativas da rede SIRGAS implantadas em parte do território nacional, a associação entre dados altimétricos das estações SIRGAS com a quantidade de água armazenada no subsolo, detectada pelo sistema de satélites GRACE, ocorrem de maneira precária. A avaliação dessa hipótese envolveu a correlação entre dados de variação de altitudes das estações ativas da rede SIRGAS e dados oriundos do sistema de satélites GRACE. Os resultados confirmaram que, em algumas das regiões hidrográficas brasileiras, foi encontrada uma correlação estatística entre a variação altimétrica da rede SIRGAS e os dados GRACE. Os resultados sugerem que o adensamento da rede de estações ativas pode resultar na configuração de um sistema de monitoramento hidrológico, de fundamental importância nos eventos climáticos extremos, como os que produzem crises de abastecimento hídrico ou alagamentos e inundações. Na tese também foi proposto um novo modelo geoidal para o estado de Goiás, o MODGEO-GO, elaborado a partir de novos levantamentos em campo que propiciaram um adensamento da rede gravimétrica do estado de Goiás. O MODGEO-GO poderá contribuir, com maior eficácia, para o planejamento e implantação de grandes obras de infraestrutura necessárias para o desenvolvimento goiano. Finalmente, foi realizada a avaliação do modelo de interpolação global, com efeito local, denominado Thin Plate Spline, utilizando-se dados do MAPGEO2105. Os resultados mostraram o grande potencial desse interpolador, que pode ser adotado em futuras modelagens de superfícies geoidais no Brasil.

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Yehuwalashet, Ezra. "Gravity and Magnetic Survey, Modelling and Interpretation in the Blötberget Iron-Oxide Mining Area, Bergslagen, Sweden." Thesis, Uppsala universitet, Geofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-305964.

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The Blötberget mining area, the focus of this MSc project, is located about 230 km northwest ofStockholm and 12 km southwest of the city of Ludvika (central Sweden). The mining area has beenknown since 1600 for its various types of mineralization particularly iron-oxide deposits (magnetite andhematite) with the mining commenced in 1944. Previous geoscientific research in the area providesdetailed information about lithological variations and structure of the bedrock near the surface.However, knowledge of the depth extent of the mineral deposits and their host rocks is limited. To shedlights on these issues and support deep mineral exploration potential in the study area, within the recentlylaunched StartGeoDelineation project, new ground gravity data, 180 data points on average 150 m apart,were collected during two field campaigns in 2015 and 2016. Aeromagnetic data were obtained fromthe Geological Survey of Sweden (SGU) to complement the ground gravity measurement interpretationsand modelling. After a careful inspection of the field gravity data, they were reduced to completeBouguer anomaly with a maximum error estimate of about 0.6 mGal due to uncertainty in theinstrumental drift, slab density, geodetic surveying, diurnal variations and terrain (or topography)correction. The Bouguer gravity data after separation of regional field (second order polynomial at theend was used) were used (~ 8 mGal range) for interpretation and 3D inverse modelling. Clear anomalouszones are noticeable in the gravity data particularly due to mineralization and a major boundaryseparating a gravity low from gravity high in the southern part of the study area likely representing afault boundary separating two different lithological units. In my study, both forward and inversemodelling using rudimentary objects/shapes and voxel-type (mesh) approach were carried out. Effect ofinitial and reference models were tested on both gravity and magnetic datasets. While the constrainedmodels have still significant ambiguity, they help to suggest structural control on the location ofmineralization and may allow estimating an excess tonnage due to the presence of mineralization in thestudy area. Due to access limitations (e.g., unable to measure on the water-filled pit) the gravity modelis sensitive to the measuring positions and constraints using known shape of mineralization was not atthe end successful to overcome this. Collecting more gravity data on the target area and repeated test of3D inversion by adjusting the inversion parameters might help to improve the final result.
Gruvområdet Blötberget som denna MSc avhandling är fokuserat kring ligger 230 km från Stockholm,12 km från Ludvika, i Bergslagen. Mineralförekomster, framförallt järnmalm (magnetit och hematit)har varit kända i området sedan 1600-talet, och storskalig brytning inleddes år 1944. Tidigare geologiskaundersökningar i området har gett detaljerad information om fyndighetens ytnära litologi och struktur.Hur långt ner förekomsten och moderbergarten sträcker sig har dock varit okänt. Som del av detnystartade projektet StartGeoDelineation utfördes marknära gravimetrimätningar. Totalt 180 mätpunkter,med ett medelavstånd av 150 m, samlades in under två fältkampanjer under 2015 och 2016.Vid modellering komplementades gravimetridata med magnetometridata, insamlad under flygmätningarutförda av Sveriges geologiska undersökningar (SGU). Efter noggrann bearbetning av gravimetridatatogs den kompletta bougeranomalin fram. Det uppskattade felet är ca 0.6 mGal och är till följd avosäkerhet i korrigeringar för drift hos instrument, dygnsvariation, geodesi och topografi. Efter korrigeringav regional trend (uppskattad från 2:a ordningens pylonom, och med satt skala av 8 mGal somresultat) gjordes en 3D modell, via inversionsalgoritmer, samt en tolkning. Det står klart av framförallti gravimetridatan att det finns två avvikande zoner. Dessa indikerar mineraliseringen och en gräns i densödra delen av undersökningsområdet med gravimetridata i låg respektive höga värde. Detta återspeglartroligtvis också en förkastningszon mellan två lithologiska enheter. I denna studie har enkla geometriskaformer och voxlar (mesh) använts för bådadera forward modellering och inversionsalgoritmer. Deursprungliga och referensmodellerna testades på både dataset för gravitmetri och magnetometri. Trotsatt modellerna fortfarande visar tvetydiga resultat så kan de ändå användas för att ge förslag på struktureroch läge för mineraliseringen, och skall även kunna användas för att uppskatta tonnage. Det sistnämndakunde dock inte uppnås då punktäthet i mätdatan, till följd av att det numera vattenfyllda dagbrottet intekunde inkluderas i mätområdet, och att formen av mineraliseringen inte kunde avgränsar på etttillfredsställande sätt. För en förbättring av resultaten bör fler mätpunkter till gravimetridata samlas in iområdet så att 3D-modelleringen kan förbättras genom upprepade justeringar av inversionsparametrarna
StartGeoDelineation

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Freier, Christian. "Atom interferometry at geodetic observatories." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17795.

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Das gravimetrische Atominterferometer (GAIN) ist ein transportables Atominterferometer welches spezifisch für hochpräzise Schweremessungen in der Geodäsie und Geophysik entwickelt wurde. Es basiert auf einer Rubidium Atomfontäne, stimulierten Ramanübergängen und einer 3-Puls Mach-Zehnder Interferometriesequenz. Die vorliegende Arbeit beschäftigt sich mit der Optimierung und Anwendung von GAIN als transportables Gravimeter für Absolutschweremessungen an geodätischen Observatorien welche über den aktuellen Stand der Technik hinaus gehen. Dabei wurden eine Absolutgenauigkiet von 29 nm/s^2, eine Langzeitstabilität von 0.4 nm/s^2 sowie eine Sensitivität von 82 nm/s^2 in einer Sekunde erreicht. Die gemessene Genauigkeit und Langzeitstabilität stellen, nach dem Wissen des Authors, die bis heute besten publizierten Werte für ein transportablen Atominterferometer dar und repräsentieren einen bedeutenden Fortschritt im Bereich der Gravimetrie. Um dies zu erreichen wurden umfangreiche Verbesserungen am Gerät umgesetzt und eine ausführliche Analyse der systematischen Messabweichungen durchgeführt. Unter anderem wurden ein System zur Kompensation von Corioliskräften und Ausrichtungsfehlern, ein verbessertes Schwingungsisolationssystem zur nachträglichen Korrektur von Umgebungsvibrationen und eine magnetische Abschirmung instrumenteller Streufelder implementiert. Darüber hinaus wurden insgesamt vier Messkampagnen in Berlin, sowie an den geodätischen Observatorien in Wettzell, Deutschland und Onsala, Schweden durchgeführt, um GAIN mit anderen hochmodernen Absolut- und Relativgravimetern zu vergleichen. Der direkte Vergleich zwischen GAIN und anderen Gravimetern stellt den prinzipbedingten Vorteil der Atominterferometrie durch die Kombination aus Absolutgenauigkeit, Stabilität und Langzeitbetrieb klar hervor. Dies wurde in der Arbeit durch die um einen Faktor 2-5 verbesserte Kalibrierung des Skalenfaktor von zwei supraleitenden Gravimetern demonstriert.
The gravimetric atom interferometer (GAIN) is a transportable setup which was specifically designed to perform high-precision gravity measurements at sites of interest for geodesy or geophysics. It is based on a Rb atomic fountain, stimulated Raman transitions and a three-pulse Mach-Zehnder atom interferometry sequence. The presented work is concerned with the optimization and application of GAIN as a transportable gravimeter in order to perform gravity measurements beyond the state-of-the-art. An absolute accuracy of 29 nm/s^2, long-term stability of 0.4 nm/s^2 and short-term noise level as low as 82 nm/s^2 in one second was achieved. The obtained long-term stability and accuracy values are, to the knowledge of the author, the best published performance of any transportable atom interferometer to date and represent a significant advancement in the field of gravimetry. A comprehensive analysis of the systematic error budget was performed to improve the accuracy and stability of the measured gravity value. Several setup improvements were implemented to this end, including Coriolis force and alignment control systems, an improved vibration isolator with post-correction and magnetic shielding which reduces spurious coupling due to stray fields. Measurement campaigns were conducted in Berlin and at geodetic observatories in Wettzell, Germany, and Onsala, Sweden, in order to compare GAIN to other state-of-the-art absolute and relative gravimeters. The direct comparison of GAIN to other absolute and relative gravimeters shows the general advantage of atom interferometers due to their unique combination of absolute accuracy, stability and robust architecture enabling continuous measurements. This was demonstrated during the presented campaigns by the improvement of the scale factor calibration of two superconducting gravimeters by a factor 2 to 5 using GAIN data.

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Bergamaschi, Jonathan Melo. "Ataque acido a argamassa de cimento comum e com escoria : um estudo cinetico e gravimetrico de degradação." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250454.

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Orientador: Ines Joekes
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Este trabalho descreve o comportamento degradativo de ataque ácido em argamassas preparadas com dois tipos de cimento com escória (compostos) e um sem escória (comum) analisado via gravimetria e pela velocidade de ataque. Os fatores como período de cura, concentração do ácido e tipo (ácido clorídrico, HCl, sulfúrico, H2SO4, e ácido acético, HAc) foram controlados. Nos ensaios de ataque ácido analisados por gravimetria, o ácido sulfúrico se comportou o mais agressivo em todos os tipos de cimento estudados. Porém em ensaios com corpos de prova de CP-III, nas primeiras semanas de imersão neste ácido, houve um aumento de massa. Após esse período a perda de massa foi intensa, devido o agravante do ataque por íons sulfatos. A velocidade de degradação da argamassa é influenciada fortemente pela natureza do ácido. O ácido orgânico é o consumido mais rapidamente. Contudo, para argamassa de cimento composto, a velocidade de consumo de ácido é menor em baixa concentração. HCl ataca mais rapidamente argamassa curada por 28 dias do que H2SO4 em concentração 0,010 mol L. O efeito do tempo de cura mostra diferença de velocidade ao ataque ácido entre HCl e H2SO4; com corpos de prova curados por 7 dias, HCl é mais rapidamente consumido, mas em corpos de prova curados por 91 dias, H2SO4 é consumido mais rápido. A análise de imagens superficiais dos corpos de prova em ensaios utilizando soluções de mesmo pH confirma a proporcionalidade direta entre a força do ácido e a agressividade. Diferente comportamento é também observado para argamassa preparada com diferentes cimentos. Para períodos curtos de cura, cimento composto apresenta baixa velocidade de ataque. No entanto, quando imersos em ácido acético, argamassa de cimento tipo CP-V apresenta baixa velocidade de ataque em períodos longos de cura, quando comparado com cimento com escória. Estes resultados mostram que muitos fatores estudados influenciam na velocidade do ataque ácido e estes restringem as generalizações sobre a resistência dos cimentos.
Abstract: This work describes the degradative behaves of acid attack in mortars prepared with two slag containing cements and one without slag analyzed by gravimetria and kinetic. Conditioning factors as curing period, acid concentration and type (hydrochloric acid, HCl, sulfuric acid, H2SO4, and acetic acid, HAc) were controlled. In experiments of acid attack analyzed by gravimetria, sulfuric acid behaved the most aggressive in all studied types of cement. However in experiments with CP-III specimens, in the first weeks of immersion in sulfuric acid, it had a mass increase. After this period, the loss of mass was intense, due the aggravating of the attack for sulfate. The nature of the acid influences strongly mortar degradation rates. The organic acid is the quickest consumed. However, for slag-mortars, the rate of acid consumption is lower in less concentrated solutions. HCl attacks faster all 28-days cured mortars than H2SO4 in 0.10 mol L solutions. The effect of curing time shows differences among HCl and H2SO4 attack rate; with 7-day cured specimens, HCl is more rapidly consumed, but with 91-day cured specimens, H2SO4 is the fastest consumed. The analysis of superficial images of specimens in experiments using same pH solutions confirms the direct proportionality between the force of acid and its aggressiveness. Different behavior is also observed for mortars prepared with different cements. For short curing times, slag-cement mortars show lower rate of attack. However, when immersed in acetic acid (HAc), type III cement mortars show lower rates of attack at longer curing times, when compared to slag-cement mortars. These results show that every factor studied influenced the rate of acid attack and this restrains cement resistance generalizations.
Mestrado
Físico-Química
Mestre em Química

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Aquino, Robson dos Santos. "Levantamento gravimétrico do litoral médio do estado do Rio Grande do Sul: parte central emersa da bacia de Pelotas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/164322.

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A origem e evolução da Bacia de Pelotas está diretamente relacionada com os processos tectônicos, que por sua vez, condicionam vários processos sedimentares. Assim, o estudo da compartimentação morfoestrutural é extremamente importante no seu entendimento evolutivo. O objetivo principal foi o levantamento gravimétrico terrestre da área de estudo, seu processamento e interpretação para posterior identificação de suas principais estruturas, assim como investigar a configuração morfoestrutural da porção central da Planície Costeira do Rio Grande do Sul. O método do potencial gravimétrico (gravimetria) é amplamente usado na prospecção mineral, análise de bacias, e mapeamentos geológicos por causa do seu baixo custo e rapidez nos resultados e fornecem informação quanto a geologia e a delimitação de estruturas e descontinuidades geológicas, além de fornecer importantes informações a respeito do embasamento subjacente no caso de bacias sedimentares. A área de estudo escolhida para a aplicação da metodologia proposta compreende a parte emersa da Bacia de Pelotas, na região central da Planície Costeira do Rio Grande do Sul, aproximadamente entre as latitudes 30° e 32°10’S e as longitudes 50°40’ e 52°40’W; situa-se em uma área que abrange os municípios costeiros do litoral médio do Rio Grande do Sul entre os municípios de São José do Norte e Palmares do Sul. O principal resultado gerado foi mapas de anomalia Bouguer e seus derivados identificando quatro setores de anomalias distintas, evidenciados por altos e baixos gravimétricos e sua possível correlação com as feições estruturais do embasamento geradas ou reativadas por rifteamento proveniente da origem da Bacia de Pelotas. Futuramente, outros métodos geofísicos podem ser utilizados e integrados para contribuir com o modelo proposto neste estudo.
The origin and evolution of the Pelotas Basin is directly related to tectonic processes, which in turn affect various sedimentary processes. Thus, the study of morphostructural compartments is extremely important in its evolution understanding. The main objective was the terrestrial gravimetric survey of the study area, its processing and interpretation for later identification of its main structures, as well as to investigate the morphostructural configuration of the middle portion of coastal plain Rio Grande do Sul. The method of gravity potential (gravity), is widely used in mineral prospecting, basin analysis, and geological mapping because of its low cost and speed of results and provide information about geology and delineation of structures and geological discontinuities, and provide essential information about the underlying basis in the case of sedimentary basins. The study area chosen for the implementation of the proposed methodology comprises the emerged part of the Pelotas Basin, in central Rio Grande do Sul coastal province, between latitudes 30° and 32°10'S and longitudes 50°4' and 52°40'W, in an area covering the coastal municipalities of the middle coast of Rio Grande do Sul State between the cities of São José do Norte and Palmares do Sul. The main results generated were Bouguer anomaly maps and derivatives by identifying four sectors of distinct anomalies highlighted by high and low gravity and its possible correlation with the structural features of the basement generated or reactivated by rifting related to Pelotas Basin origin. In the future, other geophysical methods can be used and integrated to contribute to the model suggested in this study.

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Cavalheiro, Mara Lia Dias. "Levantamento gravimétrico na Jazida Carbonífera Morungava-Chico Lomã, RS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/150209.

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A presente dissertação foi desenvolvida conforme a norma 103 do Programa de Pós Graduação em Geociências da Universidade Federal do Rio Grande do Sul, que prevê a submissão da dissertação de mestrado em forma de artigo, antecedido de estado da arte do tema proposto. Na região sudeste da Bacia do Paraná estão localizados depósitos de carvão economicamente importantes nos estados do Paraná, Santa Catarina e Rio Grande do Sul. Esses depósitos são frequentemente muito alterados por intrusões vulcânicas. O objetivo principal desse estudo é mapear essas intrusões ígneas que afetam o nível de alteração térmica do carvão (rank) da Jazida carbonífera Morungava-Chico Lomã no RS. A Jazida Morungava-Chico Lomã foi descoberta no século passado e nunca foi minerada. É caracterizada por rochas orgânicas do Permiano, carvão e folhelho betuminoso, na porção sul da Bacia do Paraná. A aquisição gravimétrica foi realizada na área do depósito Morungava e na área do depósito Chico-Lomã. Para ambas a escolha dos locais de aquisição foi baseada em furos de sondagem anteriormente realizados. Com os dados dos furos de sondagem foram elaborados seguintes mapas temáticos: profundidade da primeira ocorrência de carvão; espessura cumulativa do carvão; profundidade da primeira ocorrência de diabásio; espessura cumulativa do diabásio; espessura cumulativa do diabásio na Formação Irati e espessura cumulativa do diabásio na Formação Rio Bonito. Na elaboração do artigo submetido foi realizada a sobreposição das isolinhas das espessuras cumulativa do carvão e do diabásio nos mapas de anomalia Bouguer filtrados. Essas sobreposições apresentaram correlações e auxiliaram na interpretação dos dados gravimétricos. A orientação preferencial predominante das anomalias foi NE-SW e uma orientação subsidiária de direção NW-SE, o que sugeriu um controle estrutural sobre a ocorrência de diques e/ou soleiras, sob os altos gravimétricos. Em Chico Lomã a ocorrência de uma extensa anomalia Bouguer positiva formando um trend de orientação NE-SW foi correlacionada a unidades geológicas da Planície Costeira do Rio Grande do Sul: altos gravimétricos caracterizaram a Barreira I e baixos gravimétricos, os Sistemas Lagunares I e II. O método gravimétrico se mostrou eficaz para a caracterização da jazida por meio da correlação de anomalias gravimétricas positivas com as ocorrências de diabásio.
The present dissertation was developed according to standard 103 of the Graduate Program in Geosciences of the Federal University of Rio Grande do Sul, which provides for the submission of the dissertation in the form of article, predates by state of the art proposed theme. In the southeastern region of the Paraná Basin are located economically important coal deposits in the states of Parana, Santa Catarina and Rio Grande do Sul. These deposits are often much altered by volcanic intrusions. The objective of this study is to map the igneous intrusions affecting the thermal change of level of coal (rank) of the coal deposit Morungava-Chico Lomã in RS. The coal deposit Morungava-Chico Lomã was discovered in the last century and has never been mining. It is characterized by organic rocks of the Permian, coal and bituminous shale, in the southern portion of the Paraná Basin. The gravimetric acquisition was carried in área of the deposit Morungava and in the area of the deposit Chico-Lomã. For both areas the choice of acquisition locations was based on previously conducted drilling holes. With data from the holes drilling were prepared these thematic maps: depth of the first occurrence of coal; cumulative thickness of coal; depth of the first occurrence of diabase; cumulative thickness of diabase; cumulative thickness of diabase in Irati Formation and cumulative thickness of the diabase in Rio Bonito Formation. In the elaboration of article submitted the overriding of the isolines of cumulative thickness of coal and diabase in the filtered Bouguer anomaly maps was performed. These overrides presented correlations and assisted in the interpretation of gravity data. The predominant preferential orientation of the anomalies was NE-SW and a subsidiary orientation NW-SE direction, suggesting a structural control on the occurrence of dikes and/or sills, on gravimetric high. In Chico Lomã the occurrence of an extensive positive Bouguer anomaly forming a trend of NE-SW orientation was correlated with geological units of Rio Grande do Sul Coastal Plain: gravimetric characterized the high Barrier I and low gravimetric, Systems Lagunar I and II. The gravimetric method proved efficient for the characterization of the deposit through the correlation of positive gravity anomalies with occurrences of diabase.

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Soares, Rogério Dutra. "Modelagem 2D de dados gravimétricos do Rifte Guaritas como contribuição ao conhecimento da evolução tectônica da Bacia do Camaquã." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/36047.

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Este trabalho visa contribuir ao estudo geotectônico relacionado à Bacia do Camaquã, no Estado do Rio Grande do Sul, a partir de dados gravimétricos provenientes do Rifte Guaritas. Com este intuito, foram propostos três modelos de um perfil que corta perpendicularmente o trend do Rifte Guaritas e suas unidades. O mapa Bouguer residual, com valores entre –36 e 29 mGal, permitiu de maneira geral, delimitar áreas que possuem diferentes profundidades de embasamento. Os altos valores de gravidade podem indicar porções onde o topo do embasamento possui baixas profundidades ou rochas de maior densidade, enquanto que baixos valores podem estar associados a grandes profundidades ou rochas de densidade inferior. Com base nos dados de gravimetria, de caráter local à regional, foi possível estabelecer e, em algumas situações, estimar, o comportamento do embasamento ao longo deste perfil. Convêm ressaltar que cada modelo proposto contou com valores diferenciados de densidades de rocha, o que resultou em pequenas diferenças, tais como estruturais e variações de profundidade do embasamento. Porém, de modo geral, os três modelos se comportam de maneira muito semelhante. Cada um dos modelos propostos pode ser separado em cinco diferentes compartimentações que refletem as variações gravimétricas ao longo do perfil. De acordo com os modelos propostos neste trabalho a profundidade máxima do embasamento está localizada na porção oeste do Rifte Guaritas, chegando próxima dos seis quilômetros e a porção leste possui uma extensa estrutura deposicional.
This dissertation aims to contribute to geotectonic study related to Camaqua Basin, from gravimetric data of the Guaritas Rift. For this was proposed three models of one perpendicular profile which cross the trend of the Guaritas Rift. The residual Bouguer map, with values between -36 to 29 mGal, let, in general, to delimit areas with different depth of basement. The values of gravity may show areas where the top of the basement has low depths or rocks of major density while low values could be associated to great depth or rocks of minor density. Based on the gravimetric data of regional and local character, was possible to establish or at least estimate the variations of the depth basement along to this profile. It was proposed three models and each one of them used different combinations of rock densities, what resulted in few minor differences as structural differences and few minor variations of depth of the basement. However, in a general way, the three models behaved similarly. Each one of the models proposed could be fragmented in five different compartments which reflect the gravimetric variations across the profile. According to the models proposed in this paper, the maximum depth of the basement is located at the West portion of Rift Guaritas, almost six kilometers, and the East portion has an extensive depositional structure.

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Waskow, Régis Pereira. "ASTM D5231 aplicada à caracterização da composição gravimétrica dos resíduos sólidos urbanos : estudo de caso : Novo Hamburgo, RS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/115271.

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O presente trabalho avaliou a composição gravimétrica dos resíduos sólidos urbanos (RSU) do município de Novo Hamburgo-RS. Foram realizadas 10 amostragens de diferentes setores de coleta ao longo dos meses de março e abril de 2014. Juntamente com a análise da composição gravimétrica foi avaliada a densidade dos RSU de Novo Hamburgo. No mesmo período foram realizadas amostragens da saída das esteiras de triagem da central de transbordo do município, com um total de 5 amostras. Os procedimentos amostrais seguiram a norma americana ASTM D5231/2008. A composição gravimétrica obtida para os RSU corresponde em: 57,13% matéria orgânica; 14,82% plástico; 12,69% papel; 4,34 têxtil; 1,62% metais ferrosos; 0,69% borracha; 0,49% metais não ferrosos; 0,40% couro; 0,35% madeira e 3,86% outros. O valor médio para a densidade do RSU encontrado foi de 173 kg/m³. Alguns resíduos encontrados como eletroeletrônicos, pilhas e baterias, embalagens contaminadas com óleo, alguns resíduos sólidos industriais (RSI) e outros, não deveriam ser destinados junto aos RSU. A maior fração da matéria orgânica era esperada visto que este comportamento é identificado na composição gravimétrica média dos RSU do Brasil. Os resultados demonstram um potencial para implantação do processo de compostagem pelo alto potencial de resíduos orgânicos, sendo necessário mais análises para garantir a qualidade e aplicabilidade do composto. O descarte inadequado de resíduos orgânicos e recicláveis juntos inviabiliza a reciclagem, aumentando as quantidades destinadas ao aterro sanitário. A composição gravimétrica obtida para a saída das esteiras de triagem corresponde em: 81,60% matéria orgânica; 8,63% plástico; 2,89% papel; 1,66 têxtil; 0,58% borracha; 0,52% metais ferrosos; 0,37% metais não ferrosos; 0,35% madeira; 0,23% couro e 1,81% outros. Foi identificada uma grande presença de materiais recicláveis na saída das esteiras de triagem. Ações foram propostas para aumentar a eficiência do processo de triagem e melhorar o aproveitamento dos recicláveis. Políticas públicas foram sugeridas visando à melhoria dos processos de gestão dos RSU do município. Os resultados obtidos são representativos para o período avaliado, sendo passíveis de alteração quando de amostragem em outros períodos.
The purpose of this paper is evaluate the gravimetric composition of Municipal Solid Waste (MSW) of Novo Hamburgo - RS. Ten samples were collected in different areas between March to April 2014 according to ASTM D5231/2008. Simultaneously were evaluated the MSW density and the materials collection after sorting followed the ASTM D5231/2008. The gravimetric composition of MSW consists in 57,13% of organic matter; 14,82% of plastic; 12,69% of paper; 4,34% of textile; 1,62% of ferrous metals; 0,69% of rubber; 0,49% of noun ferrous metals; 0,40% of leather; 0,35% of wood and 3,86% of others. The MSW density were 173 kg/m³. Some residues as electronics, batteries, oil contaminated packaging and some industrial solid waste should not be disposed as MSW. A larger fraction of organic matter was expected as shown in the most Brazilian analyzed papers since that behavior is known about the gravimetric average composition of MSW in Brazil. The results demonstrate the potential implementation of the composting process considering the amount of organics, requiring further analysis to ensure the quality and applicability of the produced compounds. The inappropriate disposal of organic matter and recyclables together turn unfeasible the recycling. The gravimetric composition of material after sorting consists in: 81,60% of organic matter; 8,63% of plastic; 2,89% of paper; 1,66 of textile; 0,58% of rubber; 0,52% of ferrous metals; 0,37% of non ferrous metals; 0,35% of wood; 0,23% of leather e 1,81% of others. Amounts of recyclables was identified after sorting and based on this evidence actions were proposed to increase the sorting process efficiency and improve the recycling. Public policies were recommended to enhance the MSW management. The results are representative considering this measuring period, which could change if realized in another periods.

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Sainz-Maza, Aparicio Sergio. "Caracterización gravimétrica de zonas de rift en islas volcánicas oceánicas : aplicación a las islas de Tenerife y el Hierro." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/461592.

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Los sistemas de rift en configuraciones volcánicas, se encuentran relacionadas con crecimiento de grandes edificios volcánicos y se definen como áreas de la corteza sometidas a esfuerzos extensivos que generan fracturas en forma de fisuras a través de las cuales se emite lava. Los grupos de fisuras delinean los sistemas de rift. Tradicionalmente, los sistemas de rift han sido considerados áreas de la superficie terrestre que actúan a modo de conductos profundos que enlazan las zonas de generación del magma en el manto y corteza inferior con la superficie terrestre, canalizando y controlando el ascenso de los magmas de manera directa. Algunos estudios recientes basados en datos geológicos, geofísicos y paleomagnéticos cuestionan dicho enraizamiento profundo, considerando por el contrario un origen más superficial. Dicho origen estaría asociado tanto a la tectónica regional como a procesos locales relacionados con las variaciones en la carga gravitatoria durante el proceso de desarrollo de los edificios volcánicos. Con el objetivo de contribuir al conocimiento de estos sistemas hemos elegido estudiar los sistemas de rift de Tenerife y El Hierro, ambas situadas en el Archipiélago Canario. Ambas, ofrecen la oportunidad de llevar a cabo un estudio de este tipo a la vista de sus características superficiales. Morfológicamente, estas islas presentan lo que en apariencia serían tres zonas de rift cada una, también denominadas «dorsales». En superficie, ambas islas muestran una disposición similar de su volcanismo basáltico a lo largo de estás dorsales, habiéndose propuesto tradicionalmente una configuración de triple rift en cada isla. Con el fin de obtener una imagen interna de los sistemas de rift tanto en Tenerife como en el Hierro, se desarrollaron modelos tridimensionales de contrastes de densidad del subsuelo. Estos modelos fueron obtenidos mediante la aplicación de un algoritmo genético de inversión gravimétrica que emplea como parámetros de entrada los datos de las anomalías gravimétricas. Dichas anomalías fueron calculadas a través del análisis de una gran cantidad de datos de gravedad terrestre provenientes de distintas fuentes de datos, incluidos datos recogidos expresamente para la densificación de valores de gravedad en las áreas de estudio. Son estos modelos finales, los que hemos empleado como la base sobre la que argumentar las posteriores discusiones. El modelo obtenido para la isla de El Hierro, apunta en este caso, a que los sistemas de rift, son estructuras poco enraizadas, las cuales estarían originadas a pocos kilómetros de la superficie, siendo su configuración controlada por una combinación de la tectónica regional y por procesos extensivos tanto de carga como de inestabilidades gravitatorias. Estas estructuras, serían utilizadas para facilitar el transporte lateral del magma una vez que este alcanzara los niveles más superficiales de la corteza. El modelo tridimensional obtenido para la dorsal noroeste de la isla de Tenerife, sugiere una estructura análoga a la anterior, un origen superficial de estos sistemas de rift. En cambio, la comparación entre los modelos correspondientes a la estructura bajo dicha dorsal y la estructura del subsuelo correspondiente a la parte sur de la isla, señala claras diferencias entre ambas. Esto señala a que el origen de ambas es distinto y, por tanto, el modelo volcánico de la parte sur de la isla estaría más en correspondencia con un campo volcánico monogenético que con una configuración típica de rift, como ya había sido sugerido en trabajos previos.
Rift systems in oceanic volcanic areas are related to the growth of large volcanic buildings and are defined as areas of the crust subjected to extensive stresses that generate fractures in the form of fissures through which lava is emitted. The groups of cracks delineate rift systems. Traditionally, they have been considered deep structures acting as conduits that connect the areas of magma generation in the mantle with the earth's surface, controlling the magma rise in a way direct. Some recent studies based on geological, geophysical and paleomagnetic data question this deep rooting, considering instead a shallower origin. This origin would be associated with both regional tectonics and local processes related to variations in the gravitational load during the development process of volcanic buildings. In order to increase the knowledge of these systems we have studied the rift systems of Tenerife and El Hierro, both located in the Canarian Archipelago. Both, offer the opportunity to carry out a study of this type in view of its surface characteristics. Morphologically, these islands present three potential zones of rift, also denominated "dorsales". In surface, both islands show a similar arrangement of their basaltic volcanism along these “dorsales”, having traditionally been proposed a triple rift configuration in each island. We built an internal image of the Tenerife and El Hierro rift systems based in 3D models of subsoil density contrasts. These models were obtained by the application of an inversion genetic algorithm based on gravity data which uses as input parameters gravimetric anomalies. These models are the basis on which we will develop the subsequent discussions. The model obtained for the El Hierro Island, the rift systems are poorly rooted structures. They would have a shallower origin. Moreover, the three-dimensional model obtained for the north- western ridge of the island of Tenerife suggests a structure similar to the previous one, a superficial origin of these rift systems. In contrast, the comparison between the models corresponding to the structure under the “dorsal” and the subsurface structure corresponding to the southern part of the island, shows clear differences between the two. This indicates that the origin of both is different and, therefore, the volcanic model of the southern part of the island would be more in correspondence with a monogenetic volcanic field than with a typical configuration of rift, as already had been suggested in previous works.

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Carvalho, Marcelo Jos? de. "Estrutura??o do grupo Serra Grande regi?o de Santana do Acara?- CE e a reativa??o do lineamento Sobral Pedro II, integra??o com dados geof?sicos." Universidade Federal do Rio Grande do Norte, 2003. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18784.

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The study area is located in the NW portion of the Cear? state nearby the city of Santana do Acara?. Geologically it lies along the Sobral-Pedro II lineament which limits the domains of Cear? Central and Noroeste do Cear?, both belonging to the Borborema Province.The object of study was a NE trending 30km long siliciclastic body (sandstone and conglomerate) bounded by transcurrent dextral faults. The sediments are correlated to the Ip? Formation (Serra Grande Group) from the Parnaiba basin, which age is thought to be Siluro-Devonian. Existing structural data shown that bedding has higher but variable dips (70-45) near the borders faults and much lower to subhorizontal inward the body. The brittle deformation was related to a reactivation, in lower crustal level, of the Sobral-Pedro II lineament (Destro (1987, 1999; Galv?o, 2002).The study presented here was focused in applying geophysicals methods (gravimetry and seismic) to determine the geometry of the sandstone/conglomeratic body and together with the structural data, to propose a model to explain its deformation. The residual anomalies maps indicate the presence of two main graben-like structures. The sedimentary pile width was estimated from 2D gravimetric models to be about 500-600 meters. The 3D gravimetric model stressed the two maximum width regions where a good correlation is observed between the isopach geometry and the centripetal strike/dip pattern displayed by the sediments bedding. Two main directions (N-S and E-W) of block moving are interpreted from the distribution pattern of the maximum width regions of the sedimentary rock
A ?rea estudada esta localizada geograficamente no noroeste do estado do Cear?, pr?xima ao munic?pio de Santana do Acara?. Geologicamente encontra-se inserida no noroeste da Prov?ncia Borborema junto ao lineamento Sobral-Pedro II, limite entre a Faixa Noroeste do Cear? e o Dom?nio Cear? Central. Na regi?o ocorre um corpo alongado com cerca de 30 quil?metros de extens?o de trend NE, sendo delimitado por falhas de cinem?tica dextral, composto por arenitos e arenitos conglomer?ticos correlacionados ?queles que comp?em a Forma??o Ip? do Grupo Serra Grande, de idade Siluro-Devoniana, pertencentes a Bacia do Parnaiba. Dados estruturais indicam que este corpo apresenta-se basculado, sendo que os ?ngulos junto ?s bordas variam de altos a moderados. Destro (1987, 1999) e Galv?o (2002) interpretam que esta deforma??o tenha sido causada pela reativa??o do lineamento Sobral-Pedro II, que bordeja a margem oeste do corpo. O tema abordado envolve a aplica??o conjunta de m?todos geof?sicos (m?todo potencial gravim?trico e s?smica de refra??o rasa) com dados de geologia estrutural para a determina??o da geometria deste corpo silicicl?stico, e propor um modelo para a sua deforma??o. O mapa de anomalias residuais indica que o corpo estudado ? formado por dois grabens principais. Esta cobertura sedimentar possui uma espessura da ordem de 500 a 600 metros, sendo esta estimativa feita a partir da an?lise de modelos gravim?tricos bidimensionais. O modelo 3D gravim?trico ressalta a exist?ncia de duas regi?es de m?xima espessura de sedimentos, onde ? observada uma boa correla??o entre a geometria das is?pacas e a distribui??o centr?peta do mergulho do acamamento medido nos sedimentos. Duas dire??es de movimenta??o dos blocos, uma N-S e outra E-W, s?o interpretadas a partir do padr?o de distribui??o das regi?es de m?xima espessura de sedimentos e alinhamentos das isolinhas

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Stenvold, Torkjell. "Offshore Gravimetric and Subsidence Monitoring." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5269.

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Li, Yecai. "Airborne gravimetry for geoid determination." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/NQ54797.pdf.

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Brandão, Sirlaine Diniz Ferreira. "Influência da funcionalização com grupos contendo oxigênio na dispersão de nanotubos de carbono de parede única em solventes do tipo amida." CNEN - Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, 2010. http://www.bdtd.cdtn.br//tde_busca/arquivo.php?codArquivo=256.

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Desde que as singulares propriedades mecânicas e condutoras dos nanotubos de carbono (NCs) estão associadas a tubos individuais isolados, a dispersão e estabilização de seus feixes em diferentes líquidos são de extrema importância em estudos fundamentais e aplicados. Solventes do tipo amida são atualmente considerados os melhores candidatos, dentre os solventes orgânicos, à dispersão quantitativa dos feixes de nanotubos, sendo que a funcionalização das paredes dos tubos favorece essa dispersão em determinados meios. Amostras brutas de nanotubos de carbono são compostas por feixes contendo até centenas de tubos com distribuição em diâmetro, comprimento, quiralidade e caráter eletrônico, unidos por interações de van der Waals. Para a dispersão desses feixes, o potencial atrativo entre os tubos deve ser balanceado por um potencial repulsivo. Assim, o custo energético das interações nanotubosolvente, que depende fortemente da composição química da superfície dos tubos e das propriedades dielétricas do meio, precisa ser entendido. Teorias de solubilidade têm sido recentemente aplicadas no entendimento dos sistemas nanotubo-solvente. Nelas, a dispersão é favorecida quando os parâmetros de solubilidade do soluto e do solvente têm valores próximos. Nos parâmetros de Hansen, contribuições de energias dispersivas (dd), dipolares (dp) e de ligação de hidrogênio (dh) são consideradas nas interações intermoleculares. O parâmetro de Flory-Huggins (χ) estima a diferença de interação entre o soluto e o solvente, podendo ser expresso em termos dos parâmetros de Hansen. Neste trabalho, apresentamos um estudo sistemático da dispersão de nanotubos de carbono de parede única, como preparados e funcionalizados com grupos ácidos contendo oxigênio, em solventes do tipo amida. As interações nanotubos-solvente foram analisadas em termos dos parâmetros de solubilidade de Hansen e de Flory-Huggins. Por refluxo em solução de HNO3 diluída, quantidades similares (~ 0,3 mmol/g C) de grupos ácidos carboxílicos e hidroxílicos foram covalentemente introduzidos à superfície dos tubos, sem criar defeitos adicionais ou destruir tubos de diâmetros menores. Os materiais de partida e funcionalizado foram amplamente caracterizados por termogravimetria, microscopia eletrônica de varredura e transmissão, titulação potenciométrica e espectroscopias por dispersão de energia, Raman, na região do infravermelho e de fotoelétrons excitados por raios X. As dispersões obtidas por sonificação/centrifugação dos NCs, antes e após funcionalização, em N-metilpirrolidona (NMP), N,N-dimetilformamida (DMF), N,N-dimetilacetamida (DMA), Ndodecilpirrolidona (N12P) e ciclohexilpirrolidona (CHP) foram caracterizadas por espectroscopia de absorção óptica na região do ultravioleta-visível (UV-Vis). Em estudo de absorbância em função da concentração, foram estimados os limites de dispersão e os coeficientes de absorção dos nanotubos de carbono em cada solvente. A presença dos grupos funcionais aumentou a dispersabilidade dos tubos em NMP, DMF e DMA, mas diminuiu em N12P e CHP. Os coeficientes de absorção, entretanto, diminuíram para todos os solventes após oxidação, refletindo a diminuição da probabilidade da transição p-p* com a funcionalização e a interação com o solvente. Os parâmetros de solubilidade de Hansen e de interação de Flory-Huggins foram calculados para as amostras antes e após funcionalização, permitindo uma análise termodinamicamente quantitativa das interações intermoleculares nos sistemas estudados. Os valores dos parâmetros de Hansen obtidos para a amostra bruta foram dD = 18,0 MPa1/2, dP = 7,4 MPa1/2 e dH = 6,8 MPa1/2, enquanto aqueles para a amostra funcionalizada foram dD = 17,4 MPa1/2, dP = 12,0 MPa1/2 e dH = 9,2 MPa1/2. Em comparação com valores tabelados para os solventes, o parâmetro de energia dispersiva mostrou-se dominante na dispersão dos tubos não-funcionalizados, enquanto interações dipolares e ligações de hidrogênio exerceram uma maior influência na dispersão dos tubos funcionalizados com grupos oxigenados ácidos. Os parâmetros de interação de Flory-Huggins estimados mostraram que os sistemas com maior afinidade foram a amostra bruta dispersa no solvente CHP e a amostra funcionalizada dispersa nos solventes NMP, DMA e DMF.

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Gellerstedt, Jennifer, and Simon Westman. "Sambandet mellan radarsignaler och fukthalt i en lättbetongkonstruktion." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24203.

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Fukt i byggnader är vanligt och kan leda till skador. Fukten kan ge upphov till mögel och röta, vilket inte är bra för människors hälsa. Fukten kan också påverka olika egenskaper hos byggnadsmaterialen såsom hållfasthet, värmeisoleringsförmåga och ge dimensionsförändringar. Eftersom höga fukthalter kan ha en stor påverkan på materialen är det viktigt att upptäcka och fastställa problemet i ett tidigt skede. Syfte och mål med den här rapporten är att se om det finns ett samband mellan radarsignaler och fukthalt och avgöra om radarteknik är en användbar metod för att mäta fukthalt i ett byggnadselement. I det här arbetet har litteraturstudier, mätningar och analyser gjorts. Materialet som använts är lättbetong som byggts upp till fyra väggar i två olika tjocklekar, två stora och två små väggar. De stora testväggarna användes för radarmätningar och de små som provväggar till den gravimetriska metoden. Väggarna byggdes upp i ett tält där relativa luftfuktigheten (RF) och temperatur kunde styras. I början av experimentet var RF i tältet inställt på 98-99 % och temperaturen på 22 °C som därefter reglerats för att torka ut väggarna. Mätningar har utförts med radar och den gravimetriska metoden parallellt, där den sistnämnda gjorts genom att väga provväggarnas lättbetongblock vid samma tillfällen som radarmätningarna. Provväggarnas lättbetongblock torkades därefter i torkningsugn i 105 °C för att fastställa dess torrdensitet. Insamlade data från radarmätningarna har bearbetats av Radarbolagets personal. Resultaten för de olika metoderna har därefter analyserats och jämförts för att se om det finns ett samband. Resultaten från studien visar att det finns ett samband mellan fukthalt och signalerna från radarmätningarna. Fukthalten kan bestämmas på en lättbetongvägg med en felmarginal på ± 4 kgH20/m3 material, vilket motsvarar cirka 4 %. Det går att få ett bra resultat med radarmätning, metoden är däremot komplicerad men det kan finnas värde för fortsatta studier på flerskiktade konstruktioner för att avgöra om tekniken kan vara användbar för befintliga byggnadskonstruktioner.
Moisture in buildings is common and can lead to damage. The moisture can cause moldand rot, which is not good for human health. The moisture can also affect different properties of the building materials such as strength, thermal insulation and dimensional changes. Because high moisture levels can have a major impact on the materials, it is important to detect and fix the problem at an early stage. The purpose and aim of this report is to see if there is a correlation between radar and moisture content and determine whether radar technology is a useful method of measuring moisture contentin a building element. In this work, literature studies, measurements and analyzes have been made. The material used is lightweight concrete that is built up to four walls in two different thicknesses, two large and two small walls. The large test-walls were used for radar measurements and the small ones as sample-walls for the gravimetric method. The walls were built in a tent where relative humidity (RF) and temperature could be controlled. At the beginning of the experiment, the RF in the tent was set to 98-99 % and the temperature of 22 °C, which was then regulated to dry out the walls. Measurements have been made with radar and the gravimetric method in parallel, where the latter was made by weighing the sample-walls light concrete blocks at the same time as the radar measurements. The blocks of the sample walls were then dried in an oven at 105 °C to determine drydensity. The collected data from the radar measurements have been processed by the Radarbolaget’s personnel. The results for the different methods have then been analyzed and compared to see if there is a relationship. The results from the study show that there is a connection between moisture content and the signals from the radar measurements. The moisture content can be determined on a light concrete wall with a margin of error of ± 4 kgH20/m3material, which corresponds to about 4 %. It is possible to get a good result with radar measurement. However, the method is complicated, but there may be value for further studies on multilayered structures to determine whether the technology can be useful for existing building constructions.

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Fernandes, Mariana Aparecida [UNESP]. "Análise, modelagem e interpretação de dados gravimétricos no lineamento Guapiara - região sudeste do estado de São Paulo." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/92923.

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A gravimetria é um método geofísico empregado para subsidiar o entendimento de estruturas em subsuperfície contribuindo para a elucidação sobre arranjo, relações e compartimentações entre massas crustais. No presente trabalho o emprego da gravimetria auxiliou na caracterização do Lineamento Guapiara, onde ocorre um enxame de diques básicos mesozóicos subparalelos às direções N40-50W com 600 km de extensão e 20 a 100 km de largura. Os diques atravessam os terrenos pré-cambrianos e o embasamento da Faixa Ribeira e penetram na Bacia do Paraná até a altura do Rio Paraná. A elaboração de mapas de contorno isogálicos da anomalia Bouguer revelou um acentuado alto gravimétrico orientado segundo NW-SE o qual corresponde ao trend de maior concentração de diques, correlacionável ao Lineamento de Guapiara. Foram elaborados modelos crustais baseados em valores da anomalia Bouguer que caracterizam o alto gradiente gravimétrico ressaltado na área do feixe de diques, procurando reconhecer a influência do manto. Constatou-se que na região do Lineamento Guapiara ocorre um significativo afinamento da crosta, em decorrência da subida do Manto, reflexo da atividade epirogenética que representa a propagação de esforços que ocorreram na margem da placa relacionados com a tectônica divergente no interior da placa no Cretáceo
The geophysics, particularly the gravimetry, has been used to support the understanding of subsurface structures, contributing to the elucidation of arrangement, relations and partitioning between crustal masses. In the present work, the use of gravimetry helped in the characterization of the structural framework in the region of Guapiara Lineament, where there is a swarm of mesozoic basic dykes subparallel to the directions N40-50W. The dykes cross the precambrian lands and the basement of the Ribeira Belt, and penetrate in the Parana Basin to the height of the Parana River. The confection of maps of the Bouguer Anomaly revealed a accentuated high gravimetric guided by NW-SE which corresponds to the trend of highest concentration of dykes, correlated to the Guapiara Lineament. crustal models were made based on Bouguer anomaly values that characterize the high gravimetric gradient highlighted in the beam area of dykes, to recognize the influence of the mantle. It was found that occurs in the region a significant thinning of the crust, due to the rise in the mantle, reflecting the epirogenética activity which represents the spread of efforts occurred at the edge of plate tectonics related to the divergent within the plate in the Cretaceous

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Möhringer, Sandra [Verfasser]. "Decorrelation of Gravimetric Data / Sandra Möhringer." München : Verlag Dr. Hut, 2014. http://d-nb.info/1052375421/34.

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Bell, Stephanie A. "Validation of the NPL gravimetric hygrometer." Thesis, City University London, 1995. http://openaccess.city.ac.uk/7703/.

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The gravimetric hygrometer of the UK National Physical Laboratory (NPL) provides a first-principles realisation of mixing ratio - the most fundamental measure of the humidity of a gas. The operation of the NPL gravimetric hygrometer has been validated to demonstrate its satisfactory performance as a primary standard for humidity within the UK national measurement system. The measurement performance of the gravimetric hygrometer has been characterised for mixing ratios within the range 0.01 g kg to 155 g kg 4 (equivalent at atmospheric pressure to a dew-point range of -60 °C to +60 °C). The significant aspects of the measurement have been assessed in detail; these being the balances and weighing processes, the efficiency of collecting water and dry gas, and the effects of stray water in the instrument. Sources of systematic error have been identified and their effects quantified. Wherever possible, such errors have been eliminated or reduced. Elsewhere, numerical corrections have been evaluated and applied to the results of measurements. The overall uncertainty of measurement for the gravimetric hygrometer has been estimated by evaluating the uncertainties contributed by each aspect of the measurement, and combining these statistically to find the overall effect. The estimated uncertainty at a level of confidence of approximately 95% (a coverage factor of k=2) was found to range between 0.015 percent of value at the highest humidity considered, near 155 g kg 1, and 1.27 percent of value at the lower limit of 0.01 g kg1. The gravimetric hygrometer has been intercompared with the humidity generator which is the NFL standard for dew point, using nitrogen as the carrier gas in these measurements. For the conversion between values of dew point and mixing ratio, the uncertainties in the reference functions have been reviewed for the vapour pressure curve of water, and for the water vapour enhancement factor which accounts for the non-ideal behaviour of humid gases. A new calculation of the enhancement factor for nitrogen is presented. The uncertainties due to sampling were also evaluated. On average, the uncertainties due to the reference functions and those due to sampling were found to comparable with the uncertainty in the gravimetric measurements. Taking all these into account, the intercomparison measurements agreed to within the combined uncertainties of the two instruments.

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Mäkinen, Jaakko. "Geodynamical studies using gravimetry and levelling." Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/mat/geofy/vk/makinen/.

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Kwon, Jay Hyoun. "Airborne vector gravimetry using GPS/INS /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488193665237216.

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23

Senger, Alexander. "A mobile atom interferometer for high-precision measurements of local gravity." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://dx.doi.org/10.18452/16449.

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Eine Reihe fundamentaler Problemstellungen setzt die genaue Kenntnis der Erdbeschleunigung g voraus, z.B. die Neudefinition des Kilogramms im laufenden Watt-Waage-Projekt. Des Weiteren sind Gravitationsmessungen ein herausragendes Werkzeug der geophysikalischen Forschung, machen sie doch Phänomene vom oberen Erdreich bis hinab in den Erdkern zugänglich. Für Absolutmessungen geeignete Quanten-Sensoren mit höchster Präzision sind deshalb Gegenstand aktueller Entwicklungen. Diese Arbeit beschreibt die Planung und Implementierung eines solchen Sensors, der für eine überlegene absolute Genauigkeit von fünf Teilen in 10^10, zu erreichen in Messungen von 24 h, ausgelegt ist. Ein Merkmal, das dieses Instrument vor früheren Entwicklungen auszeichnet, ist seine Mobilität, die Anwendungen im Feld sowie Vergleichsmessungen mit anderen Gravimetern ermöglicht. Die quantenmechanische Wellennatur von (Rubidium-) Atomen wird genutzt, um durch kohärente Teilung, Reflexion und Wiedervereinigung der sie konstituierenden Wellenpakete mit Hilfe von Lichtpulsen ein Materiewelleninterferometer darzustellen. Auf ein Ensemble lasergekühlter Atome im freien Fall angewandt, kann deren Empfindlichkeit auf Inertialkräfte genutzt werden, um hochsensible Messungen der auftretenden Beschleunigungen zu erreichen. Eine Messpräzision von 160 nm s^(-2) / sqrt(Hz) wird demonstriert, die ausreicht, um g in 15 h mit einer statistischen Ungewissheit von 0.8 nm s^(-2) zu bestimmen; dies ist um einen Faktor acht besser, als mit den besten klassischen Absolutgravimetern üblich. Ein Vergleich mit dem Deutschen Schweregrundnetz ergibt eine Abweichung von 260 nm s^(-2) bei einer Ungewissheit von 520 nm s^(-2) in den systematischen Einflüssen. Deren wahrscheinliche Ursachen sowie geeignete Gegenmaßnahmen werden identifiziert.
Precise measurements of Earth''s gravitational acceleration $g$ are important for a range of fundamental problems - e.g. the Watt balance as an approach for a new definition of the kilogram - and a great tool to investigate geophysical phenomena reaching from the topmost layers of soil to the very core of our planet. Recently, research efforts have been made to develop dedicated quantum sensors capable of such measurements with very high precision and accuracy. This thesis describes the design and implementation of such a sensor, aiming at a superior accuracy of 0.5 ppb, resolvable in measurements of 24 h. A feature distinguishing this device from previous work is its mobility, allowing for comparison with other state-of-the-art instruments, and for applications in field use in various locations. Rubidium atoms are laser-cooled and launched on a free-fall trajectory. Exploiting the wave nature of quantum particles, coherent manipulation with light pulses is used to split, reflect and recombine the atoms'' wave-packets. The resulting matter-wave interferometer is highly susceptible to inertial forces and allows for sensitive measurements of accelerations. Inertial sensing with a precision of 160 nm s^(-2) / sqrt(Hz) was demonstrated, resulting in a measurement of g with a statistical uncertainty of 0.8 nm s^(-2) in 15 h, surpassing a conventional state-of-the-art absolute gravimeter by a factor of eight. Comparison with the German gravity reference net revealed a discrepancy of 260 nm s^(-2), well covered by the combined systematic uncertainties of 520 nm s^(-2). Likely causes for this deviation are identified and suitable countermeasures are proposed.

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Medeiros, Roberta Ladislau de. "Caracterização gravimétrica da zona de fratura São Paulo e Arquipélago São Pedro e São Paulo na porção Equatorial do Oceano Atlântico." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/14/14132/tde-12072013-092757/.

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A investigação da Terra através da gravimetria implica um grande número de informações sobre o seu interior em diferentes escalas de observação. O presente estudo considerou pesquisas anteriormente realizadas na área da Zona de Fratura São Paulo (ZFSP) e Arquipélago São Pedro e São Paulo (ASPSP), no Oceano Atlântico Equatorial, cujos dados geoquímicos e petrológicos apontam a presença de uma anomalia térmica. Nesta área alguns levantamentos geofísicos já foram realizados, mas nada que contribuísse de forma significativa através de dados gravimétricos. O objetivo principal deste trabalho é a caracterização gravimétrica da Zona de Fratura São Paulo através de dados de gravidade, anomalia ar livre, anomalia bouguer, tensor gradiente da gravidade e altura geoidal residual. Como objetivo secundário, procurou-se a expressão desta anomalia térmica no campo geopotencial. Entretanto, os resultados obtidos indicam que o efeito da batimetria sobre este dados deve ser levado em consideração. Uma vez que área de estudo está localizada na porção equatorial da dorsal mesoatlântica e o processo de compensação isostática nesta área está influenciando os valores da gravidade no local. Sendo, portanto, necessária a confluência de outros métodos geofísicos para detectar a expressão desta anomalia térmica.
The investigation of the Earth by gravity implies a lot of information about the interior at different scales of observation. This study considered research previously conducted in the area of St. Paul Fracture Zone (ZFSP) Archipelago and St Peter and St Paul (ASPSP), the Equatorial Atlantic Ocean, whose petrological and geochemical data indicate the presence of a thermal anomaly. In this area some geophysical surveys have been conducted, but nothing that would contribute significantly by gravity data. The main objective of this work is the characterization of gravimetric St. Paul Fracture Zone by gravity data, free air anomaly, Bouguer anomaly, the gravity gradient tensor and residual geoid height. As a secondary objective, have sought the expression of this thermal anomaly in the field geopotential. However, the results indicate that the effect of bathymetry on this data should be taken into consideration. Since the study area is located in the equatorial portion of the mid-ridge atlantic and the process of isostatic compensation in this area is influencing the gravity values at the site. Therefore required the confluence of other geophysical methods to detect the expression of this thermal anomaly.

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Krocker, Ralf [Verfasser]. "Korrelation von Gravimetrie und Bathymetrie zur geologischen Interpretation der Eltanin-Impaktstruktur im Südpazifik = Correlation of gravimetry and bathymetry for the geologic interpretation of the eltanin impact structure in the south pacific / Ralf Krocker." Bremerhaven : AWI, Alfred-Wegener-Institut für Polar- und Meeresforschung, 2008. http://d-nb.info/101011610X/34.

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Middlemiss, Richard Paul. "A practical MEMS gravimeter." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7788/.

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The ability to measure tiny variations in the local gravitational acceleration allows – amongst other applications – the detection of hidden hydrocarbon reserves, magma build-up before volcanic eruptions, and subterranean tunnels. Several technologies are available that achieve the sensitivities required (tens of μGal/√Hz), and stabilities required (periods of days to weeks) for such applications: free-fall gravimeters, spring-based gravimeters, superconducting gravimeters, and atom interferometers. All of these devices can observe the Earth tides; the elastic deformation of the Earth’s crust as a result of tidal forces. This is a universally predictable gravitational signal that requires both high sensitivity and high stability over timescales of several days to measure. All present gravimeters, however, have limitations of excessive cost (£70 k) and high mass (<8 kg). In this thesis, the building of a microelectromechanical system (MEMS) gravimeter with a sensitivity of 40 μGal/√Hz in a package size of only a few cubic centimetres is discussed. MEMS accelerometers – found in most smart phones – can be mass-produced remarkably cheaply, but most are not sensitive enough, and none have been stable enough to be called a ‘gravimeter’. The remarkable stability and sensitivity of the device is demonstrated with a measurement of the Earth tides. Such a measurement has never been undertaken with a MEMS device, and proves the long term stability of the instrument compared to any other MEMS device, making it the first MEMS accelerometer that can be classed as a gravimeter. This heralds a transformative step in MEMS accelerometer technology. Due to their small size and low cost, MEMS gravimeters could create a new paradigm in gravity mapping: exploration surveys could be carried out with drones instead of low-flying aircraft; they could be used for distributed land surveys in exploration settings, for the monitoring of volcanoes; or built into multi-pixel density contrast imaging arrays.

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Mohamoud, Mohamoud Abdirahman. "Gravimetric and viscoelastic investigation of electroactive films." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/9941.

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Gravimetric and viscoelastic studies of thin electroactive polymer films and self-assembled monolayers were carried out using (non)-electrochemical techniques; notably cyclic voltammetry, EQCM and crystal impedance. Mobile species dynamics accompanying film redox switching due to thermodynamic and electroneutrality constraints were theoretically modeled and experimentally determined. In a novel approach, 3D visual models of solvent and ion transfers under mixed control of thermodynamic and kinetic conditions were described. For the identification of change in behaviour at partial conversion during film redox transformations, flux ratio representations were introduced. Applications of the theoretical models to polyaniline data in EQCM experiments revealed that film solvent population was in equilibrium on the experimental timescale but showed thermodynamic non-ideality. Mass and charge responses of polyaniline gravimetric data were described by a mechanism in which electroneutrality maintenance was satisfied by a mixed transfer of proton and anion. Adsorption/desorption mechanisms of dendrimer on flavin-functionalised surfaces were gravimetrically determined. The energetics and isotherm models of the adsorption/desorption process were investigated. Frumkin model was found to best fit to the experimental data and site-site interaction parameter was extracted. Viscoelastic investigations of polyaniline in electrochemical systems were studied. The effects of different anions on film rheological properties during deposition and redox cycling were explored. Shear moduli data were extracted as functions of potential, temperature and timescale using TSM resonator. In an unprecedented manner, macroscopic viscoelastic properties of polyaniline films were described at a molecular level using WLF, Rouse-Zimm, and Activation models. The “time-temperature superposition” principle was applied and the master relaxation curve was constructed. In correlation between solvent content and film structural dynamics, the energetics of solvation were calculated. From thermal dependent viscoelastic responses of the film, glass transition temperature, thermal expansion coefficient and fractional free volume of polyaniline were determined.

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Volařík, Tomáš. "Redukce atmosferickych vlivu z observace supravodivych gravimetru." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-355644.

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This dissertation is focused on a study of selected environmental effects influencing terrestrial gravity observations. Global geopotential models were used to compute quantities of the disturbing gravity field and its variations during time period. Furthermore, analyses of an atmospherical and hydrological effects on the gravity observations were provided. The computation was realized at the station Pecný, however the concept was proved and compared with data from station Strasbourg. Consequently, the results were discussed with respect to quasigeoid modelling established from gravity and astrogeodetic measurements. The result and recommendations for future research are exposed.

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Caballero, Alberto. "Exploración de aguas subterráneas en el Arco Seco de Panamá (Sector de Las Tablas) mediante métodos geofísicos." Doctoral thesis, Universitat de Barcelona, 2010. http://hdl.handle.net/10803/288042.

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La investigación se ha desarrollado en la región de Las Tablas, ubicada en el denominado Arco Seco de la República de Panamá. En esta región, el abastecimiento de agua potable, debido al aumento de la población, se ve afectada por diversos factores tales como la deforestación, contaminación de acuíferos, bajos caudales, etc. La complejidad geológica y la discontinuidad estratigráfica plantean la necesidad de una estrategia de exploración adecuada. Esto se debe a que las rocas cristalinas con diferentes grados de alteración presentan propiedades hidráulicas muy diferentes. Por otro lado, los acuíferos pueden estar limitados las estructuras lineales producidas por procesos de tectónicos. Es por ello que, en este estudio, se aborda el problema mediante el empleo de un concepto exploratorio diferente, integrando procedimientos geofísicos, geológicos, hidroquímicos e isotópicos. Las rocas de la zona están constituidas por secuencias volcano Sedimentarias, cuyo origen se ubica en el Cretácico. En estas se distinguen la formación Playa Venado y las de la formación Valle Riquito, de origen volcánico e intrusivo respectivamente. También se han caracterizado las litologías de la formación Macaracas de origen sedimentario. El análisis hidroquímico de los puntos de aguas seleccionados en el sector NE indica que la mayor parte de las aguas muestreadas no presenta un catión dominante. Estas se encuentran en la región intermedia con una composición cálcico-sódico-potásica con una facies bicarbonatada. Los puntos de agua seleccionados en el sector SW, en el triángulo de los aniones, al igual que en el caso del sector NE, presentan una predominancia de los bicarbonatos. Estos puntos fueron muestreados durante la estación seca. En el caso del triángulo de los cationes, no existe un catión dominante y las muestras corresponden a una mezcla de aguas magnésicas, cálcicas y sódicas-potásicas. Este primer análisis muestra que las aguas subterráneas tienen poca evolución e interacción con la roca encajante en su recorrido. Los puntos muestreados durante la estación lluviosa presentan resultados similares a los obtenidos en la estación seca. También se ha utilizado el análisis de isótopos estables), los datos obtenidos corresponden a las dos estaciones seca (abril 2006) y lluviosa (noviembre-diciembre de 2006). Estos datos indican que la concentración isotópica en las aguas superficiales y subterráneas difiere durante la época seca. Los métodos geofísicos empleados en este estudio, se seleccionaron en función de los objetivos planteados y de los medios técnicos disponibles. La combinación de técnicas de campo natural y a escala regional, como la magnetometría y la gravimetría, con los métodos geoeléctricos de detalle, han aportado información complementaria entre sí. La magnetometría ha permitido determinar las principales alineaciones estructurales y los emplazamientos de los diques intrusivos y volcánicos, mientras que la gravimetría ha contribuido además a delimitar una cuenca sedimentaria de más de 700 metros de grosor que puede considerarse un acuífero potencial. Por otro lado, los SEV's y las tomografías eléctricas han demostrado su aplicabilidad para definir la geometría de las estructuras de interés hidrogeológico. La integración de todas las técnicas de estudio aplicadas ha permitido obtener respuestas coherentes con las hipótesis planteadas para resolver el problema en estudio. En el análisis mediante el empleo de los métodos geoeléctricos, el cálculo de la respuesta de modelos teóricos facilita la interpretación de los datos de campo. Además, ayuda a comprender y resolver el problema de la equivalencia, ya que se puede incorporar información a priori o comprobar el efecto de iniciar el proceso de inversión a partir de una u otra hipótesis geológica. La adecuada selección del dispositivo electródico es esencial, ya que este en función de la sensibilidad y penetración puede dar lugar a modelos sustancialmente diferentes.

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30

Bitalová, Katarína. "Gravimetrická měření a opakovaná nivelace na polygonu Tetčice." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-227127.

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This master's thesis deals with measurements of highs and gravity of points polygon located in village Tetčice, through which is crossing a eastern fault of Boskovice furrow. With repeated measurement should be proved effect to high levels of groundwater. Repeated measurements are realized in the range 2 stages. In thesis is in detail described calculation complete Bouguer gravity anomaly and their quantitative interpretation. From the gravimetric of dates is created map of complete Bouguer gravity anomaly and interpretative profile through Boskovice furrow. Interpretative profile has localized fault, whose tectonic activity belong to possible factors level movement in the village. Level measurements meets the requirement of precise levelling. The results of the measurements are compared and discussed with the previous stages of the research.

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31

Danila, Uliana. "Mold2012 : a new gravimetric quasigeoid model over Moldova." Licentiate thesis, KTH, Geodesi och geoinformatik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105755.

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In order to be able to use the operational Moldavian GNSS Positioning System MOLDPOS efficiently for the determination of normal heights in surveying engineering, e.g. during the construction of a road, an accurate quasigeoid model is needed. The main goal of this thesis is to present a new gravimetric quasigeoid model for Moldova (Mold2012), which has been determined by applying the Least Squares Modification of Stokes’ formula with Additive corrections (LSMSA), also called the KTH method. Due to limited coverage of gravity data, the integration area is often limited to a small spherical cap around the computation point, which leads to a truncation error for geoid height. Molodensky et al. (1962) showed that the truncation error can be reduced by the modification of Stokes’ formula, where the measured gravity data are combined with the low-frequency component of the geoid from a Global Gravitational Model (GGM). The LSMSA technique combines the GGM and the terrestrial data in an optimum way. In order to find the most suitable modification approach or cap size it is necessary to compare the gravimetric height anomalies with the GPS/levelling derived height anomalies, and for this purpose we use a GPS/levelling dataset that consists of 1042 points with geodetic coordinates in the MOLDREF99 reference system and normal heights at the same points given in the height system Baltic 77. The magnitude of the additive corrections varies within an interval from -0.6 cm to -4.3 cm over the area of Moldova. The quasigeoid model which results from combining the ITG-Grace02s solution (with n = M = 170, ψ0 = 3° and σΔg = 10 mGal) and the solution obtained from the modified Stokes’ formula together with the additive correction gives the best fit for the GPS/levelling data with a standard deviation (STD) of ±7.8 cm. The evaluation of the computed gravimetric quasigeoid is performed by comparing the gravimetric height anomalies with the GPS/levelling derived height anomalies for 1042 points. However, the above heterogeneous data include outliers, and in order to find and eliminate these, a corrector surface model is used. This surface provides a connection to the local vertical when the GNSS technique is used. After the elimination of the suspicious outliers (170 points) according to a 2-RMS test, a new corrective surface was computed based on the remaining 872 GPS/levelling points, and the STD of residuals became ±4.9 cm. The STD value for the residuals according to the order of the levelling network for the Mold2012 fitted to the local vertical datum is 3.8 cm for the I-order, 4.3 cm for the II-order, 4.5 cm for the III-order and 5.0 cm for the IV-order levelling network. But the STD of the residuals for the 18 control points indicates a better result where the STD is 3.6 cm and RMS is 3.9 cm and the min and max value of residuals is -5.3 cm and 9.0 cm, respectively. As the STD of the differences in height anomaly are not just the standard error of the height anomalies (quasigeoid model), but it contains also the standard errors of GPS heights and of normal heights. Assuming that the latter STDs are 3 cm and 3.5 cm, respectively, the STD of Mold2012 is estimated to 1.7 cm.

QC 20121127

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Termens, Perarnau Maria Assumpció. "A network approach for strapdown inertial kinematic gravimetry." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/145319.

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Compared to the conventional ground measurement of gravity, airborne gravimetry is more efficient and cost-effective. Especially, the combination of GPS and INS is known to show very good performances recovering the gravity signal in the range of medium frequencies (1--100 km). The processing of airborne gravity data traditionally consists of various independent steps, such as filtering, gridding and adjustment of misfits at crossover points. Each of these steps may introduce errors that accumulate in the course of processing. Mainly, the extraction of gravity anomalies from airborne strapdown INS gravimetry has been based on the state-space approach (SSA), which has many advantages but displays a serious disadvantage, namely, its very limited capacity to handle space correlations (like the rigorous treatment of crossover points). This dissertation explores an alternative approach through the well known geodetic network approach, where the INS differential mechanisation equations are interpreted as observation equations of a least-squares parameter estimation problem. In numerical terms, the INS equations are solved by a finite difference method where the initial/boundary values are substituted with the appropriated observation equations. The author believes that the above approach has some advantages that are on worth exploring; mainly, that modelling the Earth gravity field can be more rigorous than with the SSA and that external information can be better exploited. It is important to remark that this approach cannot be applied to real-time navigation. However, here we are not trying to solve a navigation problem but a geodetic one. A discussion of the different ways to handle with the associated system of linear equations will be described and some practical results from simulated data are presented and discussed.
En comparació amb la gravimetria terrestre, la gravimetria aerotransportada és més eficient i rendible. Especialment, la combinació de INS i GPS és ben coneguda permostrar molts bons resultats al recuperar el senyal de la gravetat en el rang de freqüències mitjanes (1–100 km). L’extracció de les anomàlies de gravetat a partir de gravimetria aerotransportada SINS s’ha basat principalment en l’aproximació SSA, que té molts avantatges, però que mostra un greu inconvenient, a saber, la capacitatmolt limitada per tractar les correlacions espacials (com el tractament rigorós dels punts d’encreuament o cross-overs). Aquesta tesi examina una alternativa a través de la coneguda aproximació en xarxes extensament usada en geodèsia, en el que les equacions diferencials de mecanització del INS s’interpreten com equacions d’observació d’un problema d’estimació de paràmetres per mínims-quadrats. En termes numèrics, les equacions de mecanització INS es resolen per un mètode de diferències finites, on els valors inicials de frontera se substitueixen per equacions d’observació. L’autora considera que l’enfocament exposat té algunes avantatges que val la pena explorar; sobretot, la modelització del camp gravitatori terrestre pot sermés rigorós que amb SSA i les equacions d’observació poden ser explotades millor. És important assenyalar que aquest enfocament no es pot aplicar a la navegació en temps real. Tanmateix, en aquest cas no es tracta de resoldre un problema de navegació, sino un de geodèsic. En aquesta dissertació es presentaran diferents maneres de tractar aquest sistema d’equacions lineals i esmostraran alguns resultats pràctics a partir de dades simulades.
En comparación con la gravimetría terrestre, la gravimetría aerotransporta esmás eficiente y rentable. Especialmente, la combinación de INS y GPS es bién conocida por mostrar muy buenos resultados recuperando la gravedad en el rango de frecuencias medias (1–100 km). La extracción de las anomalías de gravedad aerotransportada SINS se ha basado fundamentalmente en el enfoque SSA, que aunque tiene muchas ventajas muestra un inconveniente grave, a saber, su capacidad muy limitada de manejar las correlaciones espaciales (como el tratamiento riguroso de crossovers). Esta tesis examina una alternativa a través de la conocida aproximación de redes ampliamente usada en Geodesia, en el que las ecuaciones de mecanización INS se interpretan como las ecuaciones de observación de un problema de estimación de paràmetros por mínimos cuadrados. En términos numéricos, las ecuaciones INS se resuelven por un método de diferencias finitas, donde los valores iniciales de frontera se sustituyen por las ecucaciones de observación apropiadas. La autora considera que el enfoque expuesto tiene algunas ventajas que valen la pena explorar, sobretodo que la modelización del campo gravitatorio terrestre puede realizarse de unamanera más rigurosa que con SSA y que las ecuaciones de observación externas y/o auxiliares pueden explotarse mejor. Es importante mencionar que, actualmente, este enfoque no puede aplicarse a la navegación en tiempo real. Sin embargo, aquí no se trata de resolver un problema de navegación, sino uno de geodésico. En esta disertación se presentan diferentes maneras de tractar el sistema lineal de ecuaciones asociado y se muestran algunos resultados prácticos a partir de datos simulados.

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33

Vajda, Peter. "The truncated geoid and the gravimetric inverse problem." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1995. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ46304.pdf.

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34

Heffer, J. S. "Towards precision gravimetry using light-pulse atom interferometry." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3014202/.

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A light-pulse atom interferometer for inertial sensing applications such as gravimetry is being commissioned, where the prototype has a target relative precision (σ g /g) of one part per million to enable geophysics applications, which is three orders of magnitude less sensitive than commercial optical gravimeters, but with the potential to exceed these. As part of this, a rubidium-85 magneto-optical trap was upgraded using optical amplification and fibre optics to capture an atom population number of O(10 8 ) and sub-Doppler cooling techniques have been used to reach ultracold temperatures of 20 μK. Several interferometer subsystems have been developed, including extensive optical systems featuring a high-specification optical modulator and laser-induced fluorescence detection. Preliminary investigations into the coherent manipulation of atomic states have been implemented and the resonance peak of a stimulated Raman transition has been observed.

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35

Mainville, Andre. "The altimetry-gravimetry problem using orthonormal base functions /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487325740718359.

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36

French, Heidi Marie. "Gravimetric and optical studies of electroactive film dynamics." Thesis, University of Leicester, 2002. http://hdl.handle.net/2381/30065.

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The novel combined Electrochemical Quartz Crystal Microbalance-Probe Beam Deflection (EQCM-PBD) technique was used to study electroactive film dynamics and determine the individual contributions made by cation, anion and solvent species to the overall redox switching mechanism. The interpretation of the responses was extended to investigate the nature of the species transfer and film thickness changes in response to volume constraints. Studies of nickel hydroxide films in LiOH electrolyte show that hydroxide is the only detected ion transferring across the electrode/electrolyte interface to maintain electroneutrality. However, there is significant contribution made by protons, which are detected indirectly as H2O. The rigid nature of the film lattice constraints on the volume within the film and results, unusually in solvent transfer being forced into the same timescale as hydroxide ions. The mechanism for a- and b- phase redox switching differs only in the balance between hydroxide and proton (H2O) contributions to electroneutrality. The volume between layers in the film lattice defines this balance. The investigation of various polypyrrole and modified polypyrrole film systems exposed to a range of electrolytes highlights the effect of anion size on the predominant ion transfer maintaining film electroneutrality and the film volume changes accompanying this process in this non-rigid material. The variation in experimental timescale employed allowed further separation of the ion, salt and solvent transfers observed. The immobilisation of the polymeric polystyrenesulphonate (PSS) anion in the polypyrrole film matrix was shown to change the ion transfer properties of the film, which can be controlled as a function of electrolyte concentration. Salicylate anions were also used to create 'templated' PPy films, which indicated large solvent contributions. Surface roughness is shown to be a determining factor of the bulk properties of the 'templated' polymer film.

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37

Abrehdary, Majid. "Recovering Moho parameters using gravimetric and seismic data." Doctoral thesis, KTH, Geodesi och satellitpositionering, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-183577.

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Isostasy is a key concept in geoscience to interpret the state of mass balance between the Earth’s crust and mantle. There are four well-known isostatic models: the classical models of Airy/Heiskanen (A/H), Pratt/Hayford (P/H), and Vening Meinesz (VM) and the modern model of Vening Meinesz-Moritz (VMM). The first three models assume a local and regional isostatic compensation, whereas the latter one supposes a global isostatic compensation scheme. A more satisfactory test of isostasy is to determine the Moho interface. The Moho discontinuity (or Moho) is the surface, which marks the boundary between the Earth’s crust and upper mantle. Generally, the Moho interface can be mapped accurately by seismic observations, but limited coverage of seismic data and economic considerations make gravimetric or combined gravimetric-seismic methods a more realistic technique for imaging the Moho interface either regional or global scales. It is the main purpose of this dissertation to investigate an isostatic model with respect to its feasibility to use in recovering the Moho parameters (i.e. Moho depth and Moho density contrast). The study is mostly limited to the VMM model and to the combined approach on regional and global scales. The thesis briefly includes various investigations with the following specific subjects: 1) to investigate the applicability and quality of satellite altimetry data (i.e. marine gravity data) in Moho determination over the oceans using the VMM model, 2) to investigate the need for methodologies using gravimetric data jointly with seismic data (i.e. combined approach) to estimate both the Moho depth and Moho density contrast over regional and global scales, 3) to investigate the spherical terrain correction and its effect on the VMM Moho determination, 4) to investigate the residual isostatic topography (RIT, i.e. difference between actual topography and isostatic topography) and its effect in the VMM Moho estimation, 5) to investigate the application of the lithospheric thermal-pressure correction and its effect on the Moho geometry using the VMM model, 6) Finally, the thesis ends with the application of the classical isostatic models for predicting the geoid height. The main input data used in the VMM model for a Moho recovery is the gravity anomaly/disturbance corrected for the gravitational contributions of mass density variation due in different layers of the Earth’s crust (i.e. stripping gravity corrections) and for the gravity contribution from deeper masses below the crust (i.e. non-isostatic effects). The corrections are computed using the recent seismic crustal model CRUST1.0. Our numerical investigations presented in this thesis demonstrate that 1) the VMM approach is applicable for estimating Moho geometry using a global marine gravity field derived by satellite altimetry and that the possible mean dynamic topography in the marine gravity model does not significantly affect the Moho determination, 2) the combined approach could help in filling-in the gaps in the seismic models and it also provides good fit to other global and regional models more than 90 per cent of the locations, 3) despite the fact that the lateral variation of the crustal depth is rather smooth, the terrain affects the Moho result most significantly in many areas, 4) the application of the RIT correction improves the agreement of our Moho result with some published global Moho models, 5) the application of the lithospheric thermal-pressure correction improves the agreement of VMM Moho model with some other global Moho models, 6) the geoid height cannot be successfully represented by the classical models due to many other gravitational signals from various mass variations within the Earth that affects the geoid.

QC 20160317

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38

Conti, Alberto. "Revamping di macchina dosatore gravimetrico." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5019/.

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39

Cunha, Ildenize B. S. "Manipulação gravimetrica automatica de soluções." [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249959.

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Orientador : Celio Pasquini
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Doutorado

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Zajíčková, Katarína. "Gravimetrická měření a opakovaná nivelace na polygonu Tetčice." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-390234.

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The object of this master´s thesis was levelling and weight measurement of the Tetčice polygon through which passes the fault of the Boskovice furrow. This is the 10th period of levelling and the second period of gravimetric measurement. The theoretical part describes the geological structure of the site, technology of high-precision levelling and technology of gravimetric measurement. The first part of the practical part deals with my own levelling measurement, the calculation of the resulting cambers and heights, consequential comparasion of the results with previous periods and, especially, with evaluation of the vertical movement tendecies. The second part of the practical part deals with my own gravimetric measurement, the calculation of the complete Bouguer gravity anomaly, creation map of complete Bouguer gravity anomaly and as well as evaluation of gravimetric measurement in relation to the results of the previous periods.

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Amarante, Rogério Rodrigues 1972. "Sistematização do processamento de dados gravimétricos aplicados a determinação do modelo geoidal." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258364.

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Orientador: Jorge Luiz Alves Trabanco
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: Com o uso de métodos adequados, receptores GNSS podem determinar coordenadas com acurácia suficiente para aplicação em projetos de engenharia. Porém a altitude elipsoidal obtida não utiliza o mesmo sistema de referência da engenharia de transportes. A altitude elipsoidal pode ser transformada em ortométrica com a utilização de modelos geoidais que são gerados a partir de dados gravimétricos. Neste trabalho são apresentados alguns conceitos introdutórios sobre a geração de modelo geoidais. Em seguida mostra o desenvolvimento de uma nova sistematização do tratamento de dados gravimétricos com objetivo de facilitar a detecção de erros, aumentar a produtividade e melhorar a organização de resultados obtidos. Dentro deste desenvolvimento, são revisadas as teorias utilizadas para transformar medições feitas com gravímetros diferenciais em aceleração da gravidade. Apresenta também técnicas de ajustamento de observações com intuito tratar erros aleatórios. A nova abordagem sugerida foi utilizada para o desenvolvimento de um software objetivando validar as idéias propostas, permitir a comparação com outras soluções existentes e também servir como uma contribuição tecnológica. Dados gravimétricos reais foram testados dentro da abordagem proposta tendo sido observados mais organização, ganho de produtividade e principalmente a detecção de erros grosseiros e aleatórios. Com a revisão do cálculo da correção da maré, percebeu-se que programas e equipamentos atualmente em uso não possuem configuração do fator gravimétrico, fato que pode influenciar em até 0; 007mGals no processamento das observações
Abstract: With the use of appropriate methods, GNSS receivers can determine coordinates with sufficient accuracy for use in projects. The ellipsoidal height obtained, however, does not use the same reference system as the one used in transportation engineering. The ellipsoidal height can be transformed to orthometric height using geoid models that are generated from gravimetric data. In this work some introductory concepts on the generation of geoid model are presented. Then it shows the development of a new approach in systematization of gravimetric data processing aiming to facilitate the detection of errors, increase productivity and improve the organization of the results obtained in the gravimetric surveys. Within this development, the theories used to convert measurements of the differences in gravity acceleration are revised. It also features adjustment techniques of observations in order to deal with random errors. The new suggested approach was used to develop software in order to validate the proposed ideas, allow comparison with other existing solutions, and also serves as a technological contribution. Gravimetric data were tested within the suggested approach. It was observed better organization, productivity gains and mainly detection of gross errors and random. With the review of the tide correction calculation, it was realized that programs and equipments now widely used have no gravimetric factor setting, a fact that can influence up to 0; 007mGals in processing the readings
Doutorado
Transportes
Doutor em Engenharia Civil

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42

Olsen, Adam Paul Flagan Richard C. Kornfield Julia A. "Scanning activity gravimetric analysis (SAGA) of aqueous polyethylene oxide /." Diss., Pasadena, Calif. : Caltech, 2006. http://resolver.caltech.edu/CaltechETD:etd-05262006-133416.

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43

Rammeloo, Clemens Vincent. "Optimisation of a compact cold-atoms interferometer for gravimetry." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8146/.

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The work presented in this thesis focusses on the development of a transportable atom-interferometry experiment and a compact fibre laser system towards precision measurements of gravitational acceleration. Interference fringes are shown with clouds of cold 87Rb atoms using co-propagating laser beams to drive stimulated Raman transitions. This is demonstrated both inside and outside of laboratory environments for which an integrated and transportable experiment is constructed. Further improvements are presented that enable the generation of clouds containing 1.7 · 108 atoms at a rate of 2.5 Hz and having a temperature of (7 ± 1) μK. This is largely due to the development of a compact laser system based on all-fibre coupled components. It is demonstrated that the laser system designed here can achieve fast frequency sweeps over 1.8 GHz within 2 ms, making it widely applicable in compact atom-interferometry experiments with rubidium atoms. This is shown by creating a Mach–Zehnder type interferometer with counter-propagating Raman beams, thus enabling measurements of gravitational acceleration. Since the laser system uses only two lasers and one fibre amplifier, a significant reduction in size is achieved, as well as a decrease in the total power consumption of the overall experiment by a third to (162 ± 7) W.

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44

Serpas, Juan Gilberto. "Local and regional geoid determination from vector airborne gravimetry." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1066757143.

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45

Dwaik, Fathi Y. "INS, GPS, and photogrammetry integration for vector gravimetry estimation /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487953204279825.

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46

Rossi, Tatiana. "indagine gravimetrica su antica strada romana." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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Le tecniche di indagine geofisica hanno lo scopo di ottenere informazioni sulla natura e sulla struttura del sottosuolo, attraverso una serie di misure effettuate dalla superficie o tramite piccoli fori ricavati nel terreno. Ciascun metodo geofisico si concentra su diverse proprietà fisiche dei terreni. In questo lavoro ci siamo occupati della riconoscibilità, attraverso metodi geofisici, dei resti di una strada romana risalente al II secolo a.C., in particolare nel tratto a Nord di Bologna, nell’area compresa tra i comuni di Bentivoglio e San Pietro in Casale. Poiché la strada nel corso degli anni ha suscitato l’interesse di diversi studiosi nel campo dell’archeologia, nel 2018 è stato deciso di aprire uno scavo nella località di Santa Maria in Duno, a nord di Bologna, al quale ha lavorato l’associazione Hydria e i suoi volontari. Unitamente al lavoro degli archeologi a diretto contatto con il manufatto, è stata realizzata una campagna di indagine (Grandi, 2018) che ha previsto l’utilizzo di più metodi geofisici quali la sismica, l’elettrica, il magnetismo e il GPR,tali prospezioni però non sembrano essere state particolarmente fruttuose nel riconoscimento del manufatto. Prima di affermare che l’invisibilità in senso geofisico di questo tratto di costruzione romana è legata alle proprietà della strada stessa (insufficiente contrasto di impedenza sismica, elettrica, magnetica con gli strati sovra e sottostanti), si è pensato di sperimentare su di essa un metodo mancante all’appello, ossia quello microgravimetrico. Accanto ad esso si è sperimentato anche il metodo sismico passivo e sono state condotte alcune ulteriori indagini elettriche.

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47

Jacob, Thomas. "APPORT DE LA GRAVIMETRIE ET DE L'INCLINOMETRIE A L'HYDROLOGIE KARSTIQUE." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2009. http://tel.archives-ouvertes.fr/tel-00404851.

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Les aquifères karstiques constituent l'essentiel des ressources en eau souterraine sur le pourtour de la Méditerranée. Leur structure et leur fonctionnement sont complexes et mal connus à cause du processus de karstification qui hiérarchise la circulation hydrodynamique en leur sein. La localisation du stockage de l'eau et de ses variations au sein de tels aquifères est difficile à mesurer et à modéliser. Nous utilisons les outils de la géodésie pour apporter de nouvelles contraintes sur le fonctionnement hydrologique et les variations de stock d'eau en milieu karstique. Ainsi, le système karstique du Durzon, (Causse du Larzac, France) fait l'objet d'un suivi par plusieurs méthodes géodésiques incluant: - Des mesures de gravimétrie absolue en trois sites répétées de manière mensuelle ; - Des mesures répétées de gravimétrie relative entre la surface et la profondeur du karst ; - Des mesures répétées de microgravimétrie ; - Des mesures inclinométriques longue base en deux sites. Nous démontrons que le couplage entre la gravimétrie absolue et relative permet d'appréhender les variations de stock d'eau sur le bassin d'alimentation étudié. Les variations inter-anuelles observées sont de l'ordre de 400 mm, et nous montrons que celles-ci s'opèrent dans certaines zones au sein des horizons supérieurs du karst : épikarst et zone d'infiltration. Une forte hétérogénéité spatiale des variations de stockage est aussi mise en évidence à l'échelle du bassin d'alimentation. Les mesures inclinométriques permettent de suivre les phénomènes d'infiltration rapide et lente dans la masse karstique fracturée. Le suivi géodésique de ce système karstique permet d'apprécier quantitativement et de façon intégrée son fonctionnement hydrologique et pourra être transposé pour l'étude d'autres aquifère karstiques.

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Bruton, Alexander Mark. "Improving the accuracy and resolution of SINS/DGPS airborne gravimetry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq64803.pdf.

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Li, Xiaopeng. "Moving base INS/GPS vector gravimetry on a land vehicle." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1195677222.

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50

Meister, R. "Estimating Antarctic ice sheet mass balance from gravimetry and altimetry." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1364858/.

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Estimates of the Antarctic ice sheet mass balance from the past ten years show great discrepancy. Deriving mass values from gravity measurements is a ffected by corrections for postglacial rebound (PGR). Calculating Antarctic ice sheet mass balance from altimetry satellites requires knowledge of surface densities. Here, two instruments were used in conjunction to constrain ice sheet mass balance. Surface height trends from the Envisat radar altimeter and mass trends from GRACE were analysed for the period January 2003 until October 2010. An analysis of errors related to GRACE gravity measurements was carried out and a best method for removal of errors was chosen. Envisat altimetry corrections were examined. Envisat surface height trends were converted into units of mass and smoothed with a 300km Gaussian filter in order to be compatible with the GRACE mass trend. This was done using a) the density of ice (917kg=m3), b) a firn density of 450kg=m3 and c) a variable surface density map of the Antarctic derived from observations of changes in the pattern of surface height trends. Subtracting the altimetry mass trend from the GRACE mass trend provides results dominated by the absence of altimetry data in the Antarctic peninsula and south of 81:6 degrees south. Therefore, ICESat altimetry trend values were added to the Envisat trend map, where available. The GRACE mass trend and the smoothed altimetry trend converted to mass show very good agreement. The diff erence between GRACE and the combined Envisat-ICESat altimetry trends can be interpreted as a combination of PGR and error. Integrating this di fference provides considerably smaller PGR values than all commonly used PGR models. The integrated area trends from both gravimetry and altimetry show mass loss for West Antarctica, mass gain for East Antarctica and an acceleration of melting in the Amundsen Sea Sector.

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Dissertations / Theses on the topic 'Gravimetri'

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