Monografias de Graduação
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Bachelor Thesis Modelagem de formas de ondas do terremoto de Poconé/MT (01/03/2025)(Universidade Federal do Rio Grande do Norte, 2026-06-16) Souza, João Paulo Pinheiro de; Nascimento, Aderson Farias do; Leite Neto, Gilberto da Silva; http://lattes.cnpq.br/4899361246925484; Lima, Marcus Vinicius Aparecido Gomes de; Nascimento, André Vinícius de SousaThe determination of focal mechanisms in Brazil is limited by the low frequency of moderate events and the sparse distribution of stations in the Brazilian Seismographic Network (RSBR). In this context, the magnitude 4.4 mR earthquake that occurred on March 1st, 2025, in Poconé/MT represents a valuable opportunity to investigate the type of fault involved and assess the stress state in the Pantanal Basin, one of the most seismically active regions in Brazil. This study aimed to determine the focal mechanism of this event through waveform inversion at regional distances, employing the simplified Cut-and-Paste (CAP) method. The inversion yielded an average cross-correlation coefficient of 82% between the observed and synthetic seismograms, and indicated a rupture at a depth of 8 km with a moment magnitude (Mw) of 4.0. The preferred mechanism reveals a strike-slip fault with a reverse component, defined by the parameters Strike:90, Dip:70º e Rake:20º. The solution indicates that the maximum horizontal compression axis (SHmax) acting in the region has a NE-SW orientation, a result consistent with the kinematics of previous intraplate events in the basin, such as the Coxim and Miranda earthquakes. Furthermore, the predominantly strike-slip character of the obtained mechanism suggests, preliminarily, a possible spatial variation in the stress regime within the Pantanal Basin, with a greater tendency toward strike-slip mechanisms in its northern portion.Bachelor Thesis Obtenção de carboximetilcelulose termorresponsiva como aditivo para sistemas de fluidos de perfuração pump and dump(Universidade Federal do Rio Grande do Norte, 2026-06-22) Lemos, Jamile Fabrine da Silva; Balaban, Rosangela de Carvalho; Lima, Bruna Luiza Batista de; Marques, Nívia do NascimentoThe objective of this study was to synthesize and evaluate carboxymethylcellulose grafted with poly(N-isopropylacrylamide) (CMC-g-PNIPAM) for use in pump-and-dump drilling fluids. To this end, PNIPAM was grafted onto CMC chains via a radical reaction. To characterize the structural properties of the resulting products, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and zeta potential analyses were performed. The formation of hybrid macromolecules resulting from the combination of the anionic nature of CMC with the thermoresponsive nature of PNIPAM was demonstrated. The thermoresponsive behavior was investigated by determining the clouding temperature using ultraviolet-visible (UV-Vis) spectroscopy. The results demonstrated that the LCST can be modulated as a function of the ratio between the components and the polymer concentration. Furthermore, the addition of NaCl led to a reduction in the LCST, bringing forward the conformational transition. Rheological tests revealed that the copolymers exhibited superior performance, notably by maintaining or increasing viscosity at elevated temperatures, in contrast to the behavior of pure CMC, which exhibited a decrease in viscosity with increasing temperature. This effect was intensified in saline media, such as synthetic seawater, where hydrophobic interactions between the polymer chains compensated for the shielding of electrostatic charges. For rheological measurements of concentrated and diluted solutions, using the methodology employed for “pump-and-dump” fluids in the field, it was observed that the copolymers exhibited thermoviscifying behavior, and the presence of salts caused some diluted concentrations to outperform the concentrated ones in terms of viscosity. When added to drilling fluids, the copolymers demonstrated good stability after aging and rheological behavior suitable for operating conditions, combining low surface viscosity at high shear rates—which facilitates pumping—and high proppant transport capacity at higher temperatures due to increased viscosity.Bachelor Thesis Síntese e caracterização do SAPO-11 visando à aplicação em reações de hidroisomerização(Universidade Federal do Rio Grande do Norte, 2026-05-25) Fonseca, João Victor Lima da; GONDIM, Amanda Duarte; ARAÚJO, A. M. M; http://lattes.cnpq.br/4924374746045892; SILVA, Edjane F. B; http://lattes.cnpq.br/1736653643786951; http://lattes.cnpq.br/6738828245487480; http://lattes.cnpq.br/9982544911852245; ARAÚJO, Aruzza Mabel de Morais .; http://lattes.cnpq.br/4924374746045892; CAVALCANTI, Livia Nunes.; http://lattes.cnpq.br/4902766144157822; SILVA, Edjane Fabiula Buriti da.; http://lattes.cnpq.br/1736653643786951The global energy landscape has undergone an intense transition in the pursuit of reducing greenhouse gas emissions, making biofuels promising alternatives for the partial replacement of fossil fuels. However, despite their environmental and energy potential, challenges related to production, economic viability, raw material availability, and technological limitations remain. In this context, catalysts play a fundamental role in the conversion of renewable hydrocarbons into fractions equivalent to those of fossil fuels. Thus, this work aimed at the synthesis and characterization of the catalytic material SAPO-11 for its application in isomerization reactions. The material was synthesized by hydrothermal crystallization using di-n-propylamine (DPA) as an organic structure driver and subsequently subjected to calcination in two stages, initially under a nitrogen flow and then under a synthetic air flow, promoting the controlled removal of the organic driver. After heat treatment, the material was characterized by different analytical techniques. X-ray diffraction results showed the preservation of the characteristic AEL crystal structure of SAPO-11, with maintenance of the main peaks at approximately 2θ = 8.1°, 9.5°, 13.2°, 15.7°, 20.3°, 21.2°, 22.1°, and 23.4°, indicating structural stability after calcination. The spectroscopic analyses confirmed the reduction of the bands associated with C–H bonds, while the TG/DTG thermal profiles demonstrated the disappearance of the thermal degradation events related to the organic structure-directing agent, evidencing the efficiency of the calcination process. The distinguishing feature of this work is the use of DPA as an organic directing agent, aiming to promote textural modifications and favor the generation of mesoporosity, minimizing diffusional limitations typical of microporous materials and potentially increasing catalytic efficiency in isomerization reactions.Bachelor Thesis Obtenção de SAF a partir da rota alcohol to jet com etanol e n-Butanol catalisado com Mo/HZSM-5(Universidade Federal do Rio Grande do Norte, 2026-05-14) Zavaleta Villanueva, Sofia Anastacya Masçon; Gondim, Amanda Duarte; Araújo, Aruzza Mabel de Morais; Caldas, Amanda Menezes; Araújo, Aruzza Mabel de Morais; Cavalcanti, Lívia Nunes; Caldas, Amanda MenezesVILLANUEVA, Sofia Anastacya Mascon Zavaleta. Production of SAF via Alcohol-to-Jet route using ethanol and n-butanol catalysed by Mo/HZSM-5. 2026. Monograph (Bachelor in Petroleum Chemistry) – Chemistry Institute, Federal University of Rio Grande do Norte, Natal, 2026. The objective of this study was to evaluate the potential of the Alcohol-to-Jet (ATJ) route for producing sustainable aviation fuels (SAF) from ethanol, n-butanol, and a mixture of the two (1:1), using a bifunctional Mo/HZSM-5 catalyst. The catalyst was synthesized from ZSM-5 zeolite, followed by ion exchange to obtain the acid form (HZSM-5) and subsequent impregnation with molybdenum (5% w/w). The materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TG/DTG), and scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), confirming the preservation of the MFI crystalline structure, the incorporation of the metal without compromising the zeolite framework, and the thermal stability of the catalysts. The reactions were conducted in a batch reactor, and the liquid products obtained were analyzed by gas chromatography coupled with mass spectrometry (GC-MS), allowing for the identification and relative quantification of the formed compounds. n-Butanol stood out as the most promising feedstock, with a selectivity of 82.67% for C12 hydrocarbons — higher than that reported in the literature for unmodified HZSM-5. The 1:1 mixture exhibited 100% selectivity for C16, while ethanol produced a broader distribution, with hydrocarbons identified from C9 to C54. The results demonstrate the potential of the Mo/HZSM-5 catalyst for application in the ATJ route, with n-butanol as the most promising feedstock for SAF production in the aviation kerosene range.Bachelor Thesis Desenvolvimento e fabricação assistida por impressão 3D de sensor eletroquímico modular à base de grafite reciclado e modificado com cobre para detecção de glifosato em cerveja(Universidade Federal do Rio Grande do Norte, 2026-06-19) Cruz, Jonathan Johnson Fernandes; Castro, Pollyana Souza; https://orcid.org/0000-0001-6768-1865; http://lattes.cnpq.br/4538444915937772; 0009-0004-6100-0685; https://lattes.cnpq.br/7696200288523073; Regiart, Daniel Matias Gaston; http://lattes.cnpq.br/2816816156208804; Queiroz, Jorge Leandro Aquino de; https://orcid.org/0000-0002-3128-5665; http://lattes.cnpq.br/1991504504377731; Neves, Ana Carolina de Oliveira; https://orcid.org/0000-0001-7741-8454; http://lattes.cnpq.br/9435525521723320Glyphosate is a widely used herbicide in agriculture, and its potential occurrence in food and beverages has driven the development of simpler, more accessible, and sustainable analytical methods. This study aimed to develop a modular electrochemical platform for the analysis of glyphosate in beer samples using graphite rods recovered from discarded zinc–carbon batteries and components fabricated by 3D printing. The modular graphite electrode, designated GR-E, was designed with a removable electroactive region, allowing its characterization before and after surface modification. The electrode surface was modified by copper electrodeposition, exploiting the interaction between glyphosate and copper species as an indirect recognition strategy for the analyte. Surface characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy provided complementary information on the morphological, elemental, and structural changes promoted by the modification. The influence of pH was investigated, and a 0.1 mol L⁻¹ phosphate buffer at pH 5.0 was selected for the analytical studies. The electrochemical response of the GR-E-Cu electrode was evaluated by differential pulse voltammetry, showing a linear relationship between the integrated peak area and the decimal logarithm of glyphosate concentration over the range of 1.0 × 10⁻⁸ to 1.0 × 10⁻⁴ mol L⁻¹, with a coefficient of determination (R²) of 0.9958. The limits of detection and quantification were estimated at 0.597 and 1.811 μg L⁻¹, respectively. When applied to nine commercial beer samples, one sample exhibited a response above the limit of quantification, whereas the remaining samples showed signals between the limits of detection and quantification, allowing analyte detection but not reliable quantification. The results demonstrate the feasibility of the proposed platform as a modular, sustainable, and low-cost strategy for electrochemical analysis. However, matrix effects associated with beer samples indicate the need for further studies on selectivity, recovery, and analytical validation.Bachelor Thesis Tratamento eletroquímico do efluente lixiviado com a cogeração de hidrogênio verde(Universidade Federal do Rio Grande do Norte, 2025-12-15) Gondim, Ysla Karoline Ferreira; Martinez-Huitle, Carlos Alberto; Gondim, Amanda Duarte; Martinez-Huitle, Carlos Alberto; Costa, Leticia Gracyelle Alexandre; Araujo, Aruzza Mabel de MoraisBachelor Thesis Estudo da liquefação hidrotérmica da microalga scenedesmus sp com catalisadores Co/gamma-Al2O3 e Na2CO3(Universidade Federal do Rio Grande do Norte, 2025-06-30) Silva, Anderson Bonifácio da; GONDIM, Amanda Duarte; ARAUJO, Aruzzza Mabel de Morais; FERNANDES, Rafael da SilvaBachelor Thesis Obtenção de carboximetilcelulose termorresponsiva como aditivo para sistemas de fluidos de perfuração pump and dump(Universidade Federal do Rio Grande do Norte, 2026-06-22) Lemos, Jamile Fabrine da Silva; Balaban, Rosangela; Lima, Bruna; Marques, NíviaThe objective of this study was to synthesize and evaluate carboxymethylcellulose grafted with poly(N-isopropylacrylamide) (CMC-g-PNIPAM) for use in pump-and-dump drilling fluids. To this end, PNIPAM was grafted onto CMC chains via a radical reaction. To characterize the structural properties of the resulting products, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and zeta potential analyses were performed. The formation of hybrid macromolecules resulting from the combination of the anionic nature of CMC with the thermoresponsive nature of PNIPAM was demonstrated. The thermoresponsive behavior was investigated by determining the clouding temperature using ultraviolet-visible (UV-Vis) spectroscopy. The results demonstrated that the LCST can be modulated as a function of the ratio between the components and the polymer concentration. Furthermore, the addition of NaCl led to a reduction in the LCST, bringing forward the conformational transition. Rheological tests revealed that the copolymers exhibited superior performance, notably by maintaining or increasing viscosity at elevated temperatures, in contrast to the behavior of pure CMC, which exhibited a decrease in viscosity with increasing temperature. This effect was intensified in saline media, such as synthetic seawater, where hydrophobic interactions between the polymer chains compensated for the shielding of electrostatic charges. For rheological measurements of concentrated and diluted solutions, using the methodology employed for “pump-and-dump” fluids in the field, it was observed that the copolymers exhibited thermoviscifying behavior, and the presence of salts caused some diluted concentrations to outperform the concentrated ones in terms of viscosity. When added to drilling fluids, the copolymers demonstrated good stability after aging and rheological behavior suitable for operating conditions, combining low surface viscosity at high shear rates—which facilitates pumping—and high proppant transport capacity at higher temperatures due to increased viscosity.Bachelor Thesis Obtenção de biocombustíveis marítimos derivados de resíduos ovinos(Universidade Federal do Rio Grande do Norte, 2025-09-30) Bezerra, Igor Cavalcante; GONDIM, Amanda Duarte; ARAÚJO, Aruzza Mabel de Morais.; https://orcid.org/0000-0002-4736-9847; http://lattes.cnpq.br/4924374746045892; https://orcid.org/0000-0001-6202-572X; http://lattes.cnpq.br/6738828245487480; https://orcid.org/0009-0007-3878-0873; http://lattes.cnpq.br/1566807170161283; Aruzza Mabel de Morais Araújo; https://orcid.org/0000-0002-4736-9847; http://lattes.cnpq.br/4924374746045892; Mayara Lopes Gundim de Macêdo; http://lattes.cnpq.br/0836545515974288Fossil fuels remain the main sources of energy used in the maritime transport sector and are largely responsible for the emission of sulfur dioxide (SO₂), a component of greenhouse gases (GHG) that significantly contribute to global climate change. In response to this scenario, the International Maritime Organization (IMO) has established increasingly strict limits on sulfur content in marine fuels, encouraging the development of renewable and sustainable alternatives. In this context, this study aims to produce and characterize a biofuel obtained from the pyrolysis of sheep tallow, an agro-industrial residue with low cost and high energy potential. Initially, the biomass was subjected to thermogravimetric analyses (TGA/DTG) to evaluate its thermal behavior, identifying degradation ranges associated with the volatilization of fatty compounds. Physicochemical analyses, such as acid index, free fatty acid (FFA) content, and saponification index, were also performed, highlighting the lower FFA content of sheep tallow (1.9%) compared to bovine tallow (3.6%), which indicates better quality of the raw material for thermal conversion. The pyrolysis process, conducted under an inert atmosphere, yielded approximately 68% bio-oil, demonstrating good conversion efficiency. The obtained product, i.e., the bio-oil, was characterized by gas chromatography coupled with mass spectrometry (GC-MS), which allowed the identification of compounds mainly belonging to the hydrocarbon, ester, and fatty acid classes. Furthermore, physicochemical tests such as flash point, viscosity, and density indicated that the bio-oil exhibits properties that meet fuel and biofuel standards, especially when used in blends with marine diesel oil (DMA). These results demonstrate that sheep tallow is a promising raw material for the production of marine biofuels, offering a technically viable, economically attractive, and environmentally sustainable alternative. Therefore, the utilization of this residue contributes not only to the mitigation of SOx and GHG emissions but also to the valorization of agro-industrial by-products, aligning with the principles of the circular economy and international requirements for sustainable energy.Bachelor Thesis Arquitetura sedimentar da Bacia do Araripe com sísmica passiva de alta frequência(Universidade Federal do Rio Grande do Norte, 2026-07-09) Alves, Aysha Join Santos; Nascimento, Aderson Farias do; Oliveira Júnior, Josibel Gomes de; Santana, Flávio Lemos deThe Araripe Sedimentary Basin, located in the interior of Northeastern Brazil, constitutes one of the most significant records of the tectono-sedimentary evolution associated with the early stages of the Gondwana supercontinent fragmentation during the Cretaceous period. Set within the geodynamic context of the Borborema Province, this basin stands out not only for its recognized paleontological and stratigraphic value but also for representing an important natural laboratory for investigating failed rifting processes in an intracontinental environment. Despite the extensive literature dedicated to the surface geology of the Araripe Basin, aspects regarding its deep architecture remain insufficiently characterized. Specifically, the geometry of the interface between the sedimentary package and the crystalline basement, as well as the crustal thickness variation beneath the basin, lack detailed geophysical investigations. This information is fundamental for refining regional tectonic models and understanding the structural evolution of the Borborema Province. In this context, the primary objective of this study is to characterize the crustal structure and sedimentary thickness beneath seismographic stations using high-frequency passive seismic methods. For this purpose, Receiver Functions were processed from teleseismic events, allowing the identification of Ps-type converted waves and their crustal reverberations associated with relevant seismic discontinuities. The simultaneous estimation of crustal thickness (H) and Vp/Vs ratio (k) was performed using the H–k stacking technique, as proposed by Zhu and Kanamori (2000). To ensure statistical robustness and the reliability of the results, the Bootstrap resampling technique was applied, enabling the quantification of uncertainties associated with the estimated parameters. The results obtained from the most stable intermediate frequency scenario (a=5.0) revealed a crustal thickness ranging between 37.6 and 43.6 km, with an estimated VP/VS ratio between 1.72 and 1.88, reflecting the geodynamic signature of the region.