http://hdl.handle.net/11422/15 Wed, 29 Jul 2026 18:50:13 GMT 2026-07-29T18:50:13Z http://hdl.handle.net/11422/29860 Title: An introduction to stochastic electrodynamics: motivations, foundations and applications Author(s)/Inventor(s): Silva, Nathália de Abreu Costa da Advisor: Souza, Carlos Farina de Abstract: This dissertation presents an introduction to Stochastic Electrodynamics (SED), a theory that seeks to reinterpret quantum phenomena based on classical principles, postulating the existence of a classical electromagnetic zero-point field (ZPF) with a Lorentz-invariant energy spectrum. The central motivation is to investigate whether this stochastic classical field can be the origin of effects traditionally associated with quantization. The work is divided into three main parts. First, we trace the historical origin of the concept of zero-point energy, from the crisis of classical physics in the face of the blackbody radiation problem – with contributions from Planck, Einstein, Stern, among others – to its initial formulation. Next, we discuss the formal foundations of SED, constructing the zero-point field from Maxwell’s equations and establishing its attributes of randomness, spectrum, and Lorentz invariance. Finally, we present some applications of the theory, focusing on its ability to derive Planck’s spectrum for blackbody radiation and to predict dispersive forces, such as the Casimir force, from classical interactions between matter and the ZPF. We conclude the dissertation by assessing the current scope, extensions, and limitations of SED, highlighting it as a fertile alternative theoretical framework for understanding quantum phenomena. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Thu, 05 Mar 2026 00:00:00 GMT http://hdl.handle.net/11422/29860 2026-03-05T00:00:00Z http://hdl.handle.net/11422/29838 Title: Transformações na condição hidrogeomorfológica da Bacia do Ribeirão Brandão (Volta Redonda, RJ): uma análise com índices espectrais e referencial geomorfológico Author(s)/Inventor(s): Almeida, Lucas Cesar Figueiredo Hoepfner de Advisor: Peixoto, Maria Naíse de Oliveira Abstract: This research analyzes geomorphological and environmental transformations in the Ribeirão Brandão watershed, located in the municipality of Volta Redonda (Rio de Janeiro State, Brazil), in the Middle Paraíba do Sul River Valley—an area subjected to intense urbanization and industrialization processes since the mid-twentieth century. The main objective is to identify and analyze trends in land-use and land-cover change in watersheds tributary to the Paraíba do Sul River through the application of spectral indices derived from remote sensing, in order to support complementary diagnostic assessments aimed at detecting transformation trajectories of fluvial systems. To this end, the Ribeirão Brandão watershed and the Curral-Leste Stream sub-basin were selected as the spatial focus, considering the period from 2014 to 2024 due to significant technogenic alterations identified in this interval. The study is based on the processing of 106 Landsat 8 satellite images, from which the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Built-up Index (NDBI) were calculated. Annual mean values of these indices were spatialized into thematic maps and analyzed both qualitatively and quantitatively, and subsequently integrated with a previously developed geomorphological interpretation of the fluvial system, with emphasis on valley confinement and bank typology. The results indicate that mean NDVI values range from 0.28 to 0.31, reflecting the predominance of sparse and discontinuous vegetation within the basin. NDWI values are persistently negative, ranging from −0.31 to −0.285, indicating low surface water availability, whereas NDBI values remain negative, between −0.115 and −0.08, characterizing an intermediate degree of artificialization in which built-up surfaces coexist with exposed soils and residual vegetation. The inverse relationship observed between NDVI and NDBI shows that periods of higher relative vegetation vigor correspond to a lower presence of impervious surfaces, suggesting a progressive reduction of residual vegetation in areas associated with urban expansion. Land-use and land-cover analysis reveals a decrease in grassland vegetation, a marked increase in exposed soil, and a moderate expansion of urbanized and arboreal areas, resulting in a fragmented land-use mosaic whose implications are reflected in the geomorphological conditions of the analyzed fluvial systems. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Wed, 17 Dec 2025 00:00:00 GMT http://hdl.handle.net/11422/29838 2025-12-17T00:00:00Z http://hdl.handle.net/11422/29835 Title: Análise geoambiental dos processos erosivos numa área de expansão urbana: estudo de caso da Bacia do Rio dos Cachorros, São luís - Maranhão Author(s)/Inventor(s): Lisboa, Gilberlene Serra Advisor: Guerra, Antônio José Teixeira Abstract: Soils play a fundamental role in the life of the planet, supporting agriculture, construction, and ecosystems. They provide nutrients and support to plants, in addition to regulating water and sheltering different organisms, which is vital for productivity and environmental balance. Understanding their formation and the importance of sustainable use is essential for the conservation of this precious and non-renewable resource. This research aims to analyze the morphopedological units in the Cachorros River basin, in order to identify the interrelationships between the distribution of gullies and land use. The methodological procedures consisted of: bibliographic surveys – in this stage, scientific, technical, and institutional materials were consulted and reviewed; cartographic surveys – cartographic data were collected and organized, including topographic maps, satellite images, Digital Elevation Models (DEMs), and thematic shapefiles; fieldwork – aimed at verifying in situ the geomorphological features, soil types, vegetation cover, and occurrence of erosive processes; Thematic map creation – these were created using software, based on the processing and cross-referencing of data obtained in previous stages; and laboratory analysis – soil samples collected in the field were subjected to physical and chemical analyses in the laboratory, following methodologies standardized by Embrapa (2017). The Cachorros River basin presents a predominance of Itapecuru Group lithology (69.10%) and a relief characterized by dissected plateaus (79.60%). The slope is mostly gentle, between 0 and 5% (65.70%), with rectilinear planar curvature (81.93%) and altitudes ranging from 12 to 22 m (29.18%). In pedological terms, Yellow Latossos of medium texture stand out (34.52%), mainly associated with natural vegetation (21.31%); industrial (12.96%) and urban (12.44%). Soil erodibility analysis indicates that 44.58% of the basin is slightly erodible, while 34.46% is highly erodible. Susceptibility to sheet erosion is predominantly moderate (48%), with low erosive potential (44.24%) and medium potential (37.06%). Compartments CMP2 and CMP3 are the most vulnerable, presenting steeper slopes and the occurrence of Argisols and Latosols. Morphological and physical analyses of the soils reveal colors ranging from reddish-yellow to yellowish-red, predominantly sandy texture, angular to subangular structure, and consistency ranging from extremely hard to loose. Soil density values ranged from 0.94 to 1.73 g/cm³, and particle density from 2.5 to 3.07 g/cm³. Porosity ranged from 25.22% to 58.95%, and granulometry showed sand (57.05%) as the dominant fraction, with clay between 4% and 23%, and silt up to 19.95%, classifying most samples as loamy sand. It is concluded that the basin lacks adequate environmental planning, suffering significant impacts from mining activities and the formation of gullies. The study reinforces the importance of morphopedological analysis as a fundamental t Publisher: Universidade Federal do Rio de Janeiro Type: Tese Wed, 17 Dec 2025 00:00:00 GMT http://hdl.handle.net/11422/29835 2025-12-17T00:00:00Z http://hdl.handle.net/11422/29832 Title: Redes de comunicação indígenas na Amazônia: mapeando a Rede Wayuri na construção de territorialidades desde a informação à mobilização no território Author(s)/Inventor(s): Lozovei, Jéssica Cristina Advisor: Hoefle, Scott William Abstract: This dissertation examines indigenous communication practices in the Upper and Middle Rio Negro region, focusing on the Wayuri Network, which operates in articulation with the Federation of Indigenous Organizations of the Rio Negro (FOIRN). Grounded in the understanding that communication and territory are inseparable dimensions for indigenous peoples, the study analyzes how traditional forms of transmitting knowledge, rooted in oral practices, rituals, and relationships with forest and river environments, are combined with contemporary technologies such as community radio, loudspeaker systems, digital platforms, and audiovisual production. The research is based on bibliographic review, documentary analysis, and fieldwork conducted between April and June 2022, which included semi-structured interviews, participant observation, and detailed systematization of materials produced by Wayuri communicators. The findings indicate that indigenous communication is not merely a technical resource, but a political field through which identities are affirmed, territorial claims are strengthened, and historical silencing is confronted. In a context where Brazil lacks specific public policies for indigenous communication, the Wayuri Network emerges as a collective strategy capable of combating misinformation, amplifying local voices, and sustaining community organization. The study shows that the appropriation of communication technologies does not replace traditional modes of relating to knowledge and territory; instead, it enhances the circulation of indigenous worldviews and expresses processes that can be understood as the indigenization of modernity. In this sense, the Wayuri Network demonstrates how indigenous communication networks operate simultaneously as spaces of resistance, cultural continuity, and the production of possible futures. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Thu, 18 Dec 2025 00:00:00 GMT http://hdl.handle.net/11422/29832 2025-12-18T00:00:00Z