630 resultados para 4D Geodesy


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Wind-generated waves in the Kara, Laptev, and East-Siberian Seas are investigated using altimeter data from Envisat RA-2 and SARAL-AltiKa. Only isolated ice-free zones had been selected for analysis. Wind seas can be treated as pure wind-generated waves without any contamination by ambient swell. Such zones were identified using ice concentration data from microwave radiometers. Altimeter data, both significant wave height (SWH) and wind speed, for these areas were further obtained for the period 2002-2012 using Envisat RA-2 measurements, and for 2013 using SARAL-AltiKa. Dependencies of dimensionless SWH and wavelength on dimensionless wave generation spatial scale are compared to known empirical dependencies for fetch-limited wind wave development. We further check sensitivity of Ka- and Ku-band and discuss new possibilities that AltiKa's higher resolution can open.

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Photoemission techniques, utilizing a synchrotron light source, were used to analyze the clean (100) surfaces of the zinc-blende semiconductor materials CdTe and InSb. Several interfacial systems involving the surfaces of these materials were also studied, including the CdTe(lOO)-Ag interface, the CdTe(lOO)-Sb system, and the InSb(lOO)-Sn interface. High-energy electron diffraction was also employed to acquire information about of surface structure. A one-domain (2xl) structure was observed for the CdTe(lOO) surface. Analysis of photoemission spectra of the Cd 4d core level for this surface structure revealed two components resulting from Cd surface atoms. The total intensity of these components accounts for a full monolayer of Cd atoms on the surface. A structural model is discussed commensurate with these results. Photoemission spectra of the Cd and Te 4d core levels indicate that Ag or Sb deposited on the CdTe(l00)-(2xl) surface at room temperature do not bound strongly to the surface Cd atoms. The room temperature growth characteristics for these two elements on the CdTe(lOO)-(2xl) are discussed. The growth at elevated substrate temperatures was also studied for Sb deposition. The InSb(lOO) surface differed from the CdTe(lOO) surface. Using molecular beam epitaxy, several structures could be generated for the InSb(lOO) surface, including a c(8x2), a c(4x4), an asymmetric (lx3), a symmetric (lx3), and a (lxl). Analysis of photoemission intensities and line shapes indicates that the c(4x4) surface is terminated with 1-3/4 monolayers of Sb atoms. The c(8x2) surface is found to be terminated with 3/4 monolayer of In atoms. Structural models for both of these surfaces are proposed based upon the photoemission results and upon models of the similar GaAs(lOO) structures. The room temperature growth characteristics of grey Sn on the lnSb(lOO)-c(4x4) and InSb(l00)-c(8x2) surfaces were studied with photoemission. The discontinuity in the valence band maximum for this semiconductor heterojunction system is measured to be 0.40 eV, independent of the starting surface structure and stoichiometry. This result is reconciled with theoretical predictions for heterostructure behavior.

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, Programa de Mestrado Profissional em Matemática em Rede Nacional, 2015.

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We compute how bulk loops renormalize both bulk and brane effective interactions for codimension-two branes in 6D gauged chiral supergravity, as functions of the brane tension and brane-localized flux. We do so by explicitly integrating out hyper- and gauge-multiplets in 6D gauged chiral supergravity compactified to 4D on a flux-stabilized 2D rugby-ball geometry, specializing the results of a companion paper, arXiv:1210.3753 , to the supersymmetric case. While the brane back-reaction generically breaks supersymmetry, we show that the bulk supersymmetry can be preserved if the amount of brane- localized flux is related in a specific BPS-like way to the brane tension, and verify that the loop corrections to the brane curvature vanish in this special case. In these systems it is the brane-bulk couplings that fix the size of the extra dimensions, and we show that in some circumstances the bulk geometry dynamically adjusts to ensure the supersymmetric BPS-like condition is automatically satisfied. We investigate the robustness of this residual supersymmetry to loops of non-supersymmetric matter on the branes, and show that supersymmetry- breaking effects can enter only through effective brane-bulk interactions involving at least two derivatives. We comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems. © 2013 SISSA.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

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The application of thermal methods, to increase the recovery of heavy oil in mature fields through drainage with multilateral and horizontal wells, has been thoroughly studied, theorically, experimentally, testing new tools and methods. The continuous injection of steam, through a steam injector well and a horizontal producer well in order to improve horizontal sweep of the fluid reservoir, it is an efficient method. Starting from an heterogeneous model, geologically characterized, modeling geostatistics, set history and identification of the best path of permeability, with seismic 3D, has been dubbed a studying model. It was studied horizontal wells in various directions in relation to the steam and the channel of higher permeability, in eight different depths. Into in the same area were studied, the sensitivity of the trajectories of horizontal wells, according to the depth of navigation. With the purpose of obtaining the highest output of oil to a particular flow, quality, temperature and time for the injection of steam. The wells studied showed a significant improvement in the cumulative oil recovery in one of the paths by promoting an alternative to application in mature fields or under development fields with heavy oil

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This study investigated the effect of different photoperiods (24 h of light (L):0 h of darkness (D); 20L:4D; 16L:8D; 12L:12D; and 8L:16D) on the reproduction and growth of Betta splendens. The results showed that spawning frequency was significantly higher in couples reared under 16L:8D and 12L:12D, in comparison with other treatments. The highest number of eggs per spawn was obtained under 16L:8D (544.76±375.23) and 12L:12D (471.13±261.52), and the lowest values were detected for 24L:0D (128.55±58.14) and 20L:4D (187.87±103.84). Fertility and fecundity also showed significantly higher average values in 16L:8D and 12L:12D when compared with 24L:0D and 20L:4D treatments. Egg volume and perivitelline space were significantly higher in 24L:0D treatments that showed the lowest numbers of eggs per spawn, while the vitelline volume did not show significant differences. Other variables such as breeders weight gain and condition factor (K) were not statistically different. Moreover, the final length varies according to photoperiod and gender. These results demonstrated a key role for the photoperiod upon B. splendens reproduction. The best reproductive performance is achieved under the photoperiods that best approached those that occur in spring and summer (16L:8D and 12L:12D), coinciding with their best seasons for reproduction.

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The objective of this Doctoral Thesis was monitoring, in trimestral scale, the coastal morphology of the Northeastern coast sections of Rio Grande do Norte State, in Brazil, which is an area of Potiguar Basin influenced by the oil industry activities. The studied sections compose coastal areas with intense sedimentary erosion and high environmental sensitivity to the oil spill. In order to achieve the general objective of this study, the work has been systematized in four steps. The first one refers to the evaluation of the geomorphological data acquisition methodologies used on Digital Elevation Model (DEM) of sandy beaches. The data has been obtained from Soledade beach, located on the Northeastern coast of Rio Grande Norte. The second step has been centered on the increasing of the reference geodetic infrastructure to accomplish the geodetic survey of the studied area by implanting a station in Corta Cachorro Barrier Island and by conducting monitoring geodetic surveys to understand the beach system based on the Coastline (CL) and on DEM multitemporal analysis. The third phase has been related to the usage of the methodology developed by Santos; Amaro (2011) and Santos et al. (2012) for the surveying, processing, representation, integration and analysis of Coastlines from sandy coast, which have been obtained through geodetic techniques of positioning, morphological change analysis and sediment transport. The fourth stage represents the innovation of surveys in coastal environment by using the Terrestrial Laser Scanning (TLS), based on Light Detection and Ranging (LiDAR), to evaluate a highly eroded section on Soledade beach where the oil industry structures are located. The evaluation has been achieved through high-precision DEM and accuracy during the modeling of the coast morphology changes. The result analysis of the integrated study about the spatial and temporal interrelations of the intense coastal processes in areas of building cycles and destruction of beaches has allowed identifying the causes and consequences of the intense coastal erosion in exposed beach sections and in barrier islands

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The purpose of the study was to explore the geography literacy, attitudes and experiences of Florida International University (FIU) freshman students scoring at the low and high ends of a geography literacy survey. The Geography Literacy and ABC Models formed the conceptual framework. Participants were freshman students enrolled in the Finite Math course at FIU. Since it is assumed that students who perform poorly on geography assessments do not have an interest in the subject, testing and interviewing students allowed the researcher to explore the assumption. ^ In Phase I, participants completed the Geography Literacy Survey (GLS) with items taken from the 2010 NAEP Geography Subject Area Assessment. The low 35% and high 20% performers were invited for Phase II, which consisted of semi-structured interviews. A total of 187 students participated in Phase I and 12 in Phase II. ^ The primary research question asked was what are the geography attitudes and experiences of freshman students scoring at the low and high ends of a geographical literacy survey? The students had positive attitudes regardless of how they performed on the GLS. ^ The study included a quantitative sub-question regarding the performance of the students on the GLS. The students’ performance on the GLS was equivalent to the performance of 12th grade students from the NAEP Assessment. There were three qualitative sub-questions from which the following themes were identified: the students’ definition of geography is limited, students recall more out of school experiences with geography, and students find geography valuable. In addition, there were five emergent themes: there is a concern regarding a lack of geographical knowledge, rote memorization of geographical content is overemphasized, geographical concepts are related to other subjects, taking the high school level AP Human Geography course is powerful, and there is a need for real-world applications of geographical knowledge. ^ The researcher offered as suggestions for practice to reposition geography in our schools to avoid misunderstandings, highlight its interconnectedness to other fields, connect the material to real world events/daily decision-making, make research projects meaningful, partner with local geographers, and offer a mandatory geography courses at all educational levels.^

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The present trail aimed to study the effect of crossbreeding between Alentejano (AL) and Bísaro (BI) swine breeds (“Ribatejano pig”) on some reproductive and productive traits. Nine AL gilts and sows and six BI gilts were crossed with BI and AL boars, respectively. Mating and farrowing dates, prolificacy and litter size at 28d were registered for all sows. The pregnancy length of AL sows was shorter (111±0.4d vs 113.7±0.5d; p=0.002) than the observed on BI females. The BI gilts presented higher prolificacy rate than AL on both total born (11.0±1.0 vs 6.7±0.8; P=0.004) and born alive piglets (10.0±1.0 vs 6.7±0.8; p=0.026). The mortality rate was similar in both genotypes (p=0.255) being on average 12%, therefore at 28d after farrowing the litter size remained higher in BI sows (8.5±0.8 vs 6.1±0.6; p= 0.032). A subset of each genotype (4 gilts) was supervised during farrowing and lactation (until 28d) and piglets were weighed at birth, 24h and 28d of live. Farrowing length was not significantly different (p=0.253) between genotypes, averaging 97±22 min. When compared to ALBI (AL x BI) piglets, the BIAL (BI x AL) piglets were heavier at birth (1402±46g vs 1209±36g; p=0.002). Colostrum intake of piglets per kg of birth weight on the first 24h of life was similar between genotypes (p=0.735) being 289±15g for ALBI and 281±19g for BIAL piglets. The growth rate of piglets from birth to 28d and piglet weight at 28d was not different between genotypes (p=0.161 and p=0.091) averaging 195±6g and 6761±181g, respectively. Litter weight at 28d tended (P=0.06) to be higher on ALBI litters (56.6±4.0kg) than BIAL litters (43.2±4.0kg). This results obtained within the frame of Treasure project* are, at our knowledge, the first data of these crossbred piglets and could be used in future as reference for further studies and also for farmers that may try these cross on a commercial basis.

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Es un hecho constatable que la cartografía y el urbanismo está íntimamente relacionado. El desarrollo tecnológico experimentado en la Cartografía y en disciplinas afines como la geodesia, la topografía, los Modelos Digitales del Terreno, la fotogrametría, la teledetección y la gestión de las basesde datos relacionadas, utilizando como herramienta los S.I.G´s, nos han permitido cartografiar, con la precisión requerida, el Término Municipal de Guadalajara-España para la ordenación del Plan 2000 y su desarrollo. Todas ellas pretendemos ponerlas en práctica para la ordenación territorial deTegucigalpa-Honduras, realizando como paso previo su Red G. P. S.Palabras clave: Cartografía, Urbanismo, Geodesia, Ordenación Territorial.ABSTRACTIt is an indisputable fact that cartography and urban planning are inextricably linked. Technological development experienced in cartography and related disciplines, such as geodesy, surveying, Digital Terrain Models, photogrammetry, remote sensing and management of related databases using GIS as the tool, has enabled us to map with required precision the municipality of Guadalajara (Spain) to manage the Plan 2000 and its development. The intention now is to implement in Tegucigalpa (Honduras) the same regional land use planning using the GPS network.Key words: Cartography. Urban Planning. Geodesy. Regional Land Use Planning. 

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The surface of the Earth is subjected to vertical deformations caused by geophysical and geological processes which can be monitored by Global Positioning System (GPS) observations. The purpose of this work is to investigate GPS height time series to identify interannual signals affecting the Earth’s surface over the European and Mediterranean area, during the period 2001-2019. Thirty-six homogeneously distributed GPS stations were selected from the online dataset made available by the Nevada Geodetic Laboratory (NGL) on the basis of the length and quality of the data series. The Principal Component Analysis (PCA) is the technique applied to extract the main patterns of the space and time variability of the GPS Up coordinate. The time series were studied by means of a frequency analysis using a periodogram and the real-valued Morlet wavelet. The periodogram is used to identify the dominant frequencies and the spectral density of the investigated signals; the second one is applied to identify the signals in the time domain and the relevant periodicities. This study has identified, over European and Mediterranean area, the presence of interannual non-linear signals with a period of 2-to-4 years, possibly related to atmospheric and hydrological loading displacements and to climate phenomena, such as El Niño Southern Oscillation (ENSO). A clear signal with a period of about six years is present in the vertical component of the GPS time series, likely explainable by the gravitational coupling between the Earth’s mantle and the inner core. Moreover, signals with a period in the order of 8-9 years, might be explained by mantle-inner core gravity coupling and the cycle of the lunar perigee, and a signal of 18.6 years, likely associated to lunar nodal cycle, were identified through the wavelet spectrum. However, these last two signals need further confirmation because the present length of the GPS time series is still too short when compared to the periods involved.

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Non-linear effects are responsible for peculiar phenomena in charged particles dynamics in circular accelerators. Recently, they have been used to propose novel beam manipulations where one can modify the transverse beam distribution in a controlled way, to fulfil the constraints posed by new applications. One example is the resonant beam splitting used at CERN for the Multi-Turn Extraction (MTE), to transfer proton beams from PS to SPS. The theoretical description of these effects relies on the formulation of the particle's dynamics in terms of Hamiltonian systems and symplectic maps, and on the theory of adiabatic invariance and resonant separatrix crossing. Close to resonance, new stable regions and new separatrices appear in the phase space. As non-linear effects do not preserve the Courant-Snyder invariant, it is possible for a particle to cross a separatrix, changing the value of its adiabatic invariant. This process opens the path to new beam manipulations. This thesis deals with various possible effects that can be used to shape the transverse beam dynamics, using 2D and 4D models of particles' motion. We show the possibility of splitting a beam using a resonant external exciter, or combining its action with MTE-like tune modulation close to resonance. Non-linear effects can also be used to cool a beam acting on its transverse beam distribution. We discuss the case of an annular beam distribution, showing that emittance can be reduced modulating amplitude and frequency of a resonant oscillating dipole. We then consider 4D models where, close to resonance, motion in the two transverse planes is coupled. This is exploited to operate on the transverse emittances with a 2D resonance crossing. Depending on the resonance, the result is an emittance exchange between the two planes, or an emittance sharing. These phenomena are described and understood in terms of adiabatic invariance theory.

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The Many-Body-Perturbation Theory approach is among the most successful theoretical frameworks for the study of excited state properties. It allows to describe the excitonic interactions, which play a fundamental role in the optical response of insulators and semiconductors. The first part of the thesis focuses on the study of the quasiparticle, optical and excitonic properties of \textit{bulk} Transition Metal Oxide (TMO) perovskites using a G$_0$W$_0$+Bethe Salpeter Equation (BSE) approach. A representative set of 14 compounds has been selected, including 3d, 4d and 5d perovskites. An approximation of the BSE scheme, based on an analytic diagonal expression for the inverse dielectric function, is used to compute the exciton binding energies and is carefully bench-marked against the standard BSE results. In 2019 an important breakthrough has been achieved with the synthesis of ultrathin SrTiO3 films down to the monolayer limit. This allows us to explore how the quasiparticle and optical properties of SrTiO3 evolve from the bulk to the two-dimensional limit. The electronic structure is computed with G0W0 approach: we prove that the inclusion of the off-diagonal self-energy terms is required to avoid non-physical band dispersions. The excitonic properties are investigated beyond the optical limit at finite momenta. Lastly a study of the under pressure optical response of the topological nodal line semimetal ZrSiS is presented, in conjunction with the experimental results from the group of Prof. Dr. Kuntscher of the Augsburg University. The second part of the thesis discusses the implementation of a workflow to automate G$_0$W$_0$ and BSE calculations with the VASP software. The workflow adopts a convergence scheme based on an explicit basis-extrapolation approach [J. Klimeš \textit{et al.}, Phys. Rev.B 90, 075125 (2014)] which allows to reduce the number of intermediate calculations required to reach convergence and to explicit estimate the error associated to the basis-set truncation.

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Introduzione: L’intervento di Fontan comporta un aumento istantaneo della pressione venosa centrale che causa, nel medio-lungo termine, una forma di epatopatia specifica detta FALD. Il monitoraggio della FALD è complesso ma potrebbe consentire di bloccarne o rallentarne l’insorgenza. Lo studio ha valutato l’efficacia delle modalità di monitoraggio non invasivo. Materiale e metodi: Sei pazienti (età media 24 anni) operati presso l’IRCCS Azienda Ospedaliero Universitaria di Bologna sono stati sottoposti a RMN 4D-Flow e ad Ecodoppler epatico. Sono stati raccolti i dati anagrafici, morfologici, anamnestici e i markers sierologici per il calcolo degli scores MELD-XI, APRI, FIB4, i valori di Shear Stress assiale e circonferenziale e gli indici di pulsatilità e resistenza delle arterie epatica e renale. Risultati: Il tempo trascorso tra la Fontan e lo studio è stato di 17,8 anni. Età media alla Fontan 6,8 anni. Tutti i pazienti avevano un quadro compatibile con epatopatia. I markers sierologici e gli scores MELD-XI,APRI e FIB4 si sono dimostrati di scarsa utilità. All’ecografia tutti i pazienti avevano ecostruttura irregolare, splenomegalia e valori elevati di pulsatilità e resistenza dell’arteria epatica e splenica. La rigidità epatica media è stata di 12,4 Kpa. Alla RMN 4DF lo Shear stress assiale è stato massimo a livello del condotto (0,16 Pa) e minimo a livello delle vene sovra epatiche (0,05 Pa). Lo Shear Stress si è mostrato massimo nei pazienti con emodinamica sfavorevole e peggior quadro ecografico addominale, evidenziando aree di inefficienza energetica. Conclusioni: La combinazione delle diagnostiche di imaging non invasive potrebbe rivelarsi adeguata per il monitoraggio della FALD. In particolare, la RMN 4D Flow potrebbe rivelare aree di inefficienza energetica predisponenti alla FALD. Questo potrebbe indirizzare in modo specifico la terapia dei pazienti operati o addirittura indurre la modifica del disegno della Fontan verso forme più efficienti.