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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Fisiologia do amadurecimento, senescência e comportamento respiratório de goiabas \'Kumagai\' e \'Pedro Sato\' / Physiology of ripening, senescence and respiratory behavior of Kumagai and Pedro Sato guava

Flavia Cristina Cavalini 06 February 2009 (has links)
O amadurecimento e a senescência tem sido diretamente relacionados ao climatério do CO2 e do etileno. No entanto, estudos recentes têm demonstrado que algumas transformações pós-colheita ocorrem independentemente desses eventos e que muitos frutos não se enquadram nas definições clássicas de padrão de atividade respiratória, indicando a necessidade de maiores estudos a respeito da fisiologia do amadurecimento e senescência de frutos. O comportamento respiratório de goiabas é contraditório, servindo como modelo para estes estudos. O uso de reguladores do amadurecimento pode auxiliar na definição do comportamento respiratório de goiabas Kumagai e Pedro Sato. Tendo-se em vista o estabelecido, conduziu-se a etapa 1, com o intuito de determinar índices que indiquem o início da senescência. A etapa 2 visou determinar o comportamento respiratório de goiabas das variedades Kumagai e Pedro Sato submetidas à aplicação de acelerador (etileno) e retardadores (1-MCP e AVG) do amadurecimento. Na etapa 1, as goiabas recém colhidas foram tratadas com fungicida e mantidas em câmara a 23 ± 1oC e 85% UR até a completa senescência. Na etapa 2, os frutos foram submetidos à aplicação de AVG, 1- MCP e etileno e então armazenados em câmara a 23 ± 1oC e 85% UR até a completa senescência. Frutos sem reguladores vegetais foram utilizados como controle. Os frutos foram avaliados a cada dois dias em ambas as etapas. O delineamento estatístico utilizado foi o inteiramente casualizado e os resultados foram submetidos à análise de dados longitudinais, devido ao caráter quantitativo imposto pelo fator tempo de armazenamento. As curvas também foram submetidas à análise do erro padrão da média. As diferenças entre dois tratamentos maiores que as somas de dois erros padrões foram consideradas significativas. Os teores de acetaldeído, etanol e o extravasamento de eletrólitos foram os índices que mais contribuíram para distinguir o amadurecimento da senescência. O aumento brusco apresentado nos teores de acetaldeído e etanol indica início do metabolismo fermentativo, comportamento característico de senescência, além do aumento no extravasamento de eletrólitos, sugerir descompartimentação celular. Os frutos da variedade Pedro Sato não podem ser classificados como climatéricos, nem tão pouco como não climatéricos, pois apesar de amadurecerem, apresentaram pico de produção de etileno após o amadurecimento dos mesmos, além de não responderem à aplicação de etileno exógeno. Apesar das goiabas Kumagai responderem à aplicação de etileno, não se observou comportamento climatério na produção de CO2 e de C2H4, desta forma, esta variedade não pode ser enquadrada nas classificações de padrão de atividade respiratória em uso. / Ripening and senescence have been directly related to CO2 and ethylene climacteric behavior. However, recent studies have shown that some postharvest processes occurs independently of those events and that many fruits are not frame in the definitions of respiratory activity traditional pattern, indicating the need for more studies on fruit ripening and senescence physiology. Guavas fruit respiratory behavior is contradictory and serves as a model for these studies. The use of ripening regulators can help in defining the respiratory behavior of Kumagai and Pedro Sato guavas. Consequently, the step 1 has been conducted, with the intention of determining indicators that indicate the beginning of the senescence. The step 2 aimed to determine the respiratory behavior of guava fruits of Kumagai and Pedro Sato cultivars subjected to the application of accelerator (ethylene) and retardants (1-MCP and AVG) of the ripening. In step 1, the newly harvested guavas were treated with fungicide and kept at 23 ± 1oC and 85% RH to complete senescence. In step 2, the fruits were submitted to AVG, 1-MCP and ethylene application and then stored at 23 ± 1oC and 85% RH to complete senescence. Fruit without ripening regulators were used as controls. The fruits were evaluated every two days in both steps. The experimental design was completely randomized and the results were submitted to longitudinal data analysis, due to the quantity of samples imposed by the storage time factor. The curves have been subjected to average standard error analysis. Differences between two treatments larger than the sum of two errors patterns were considered significant. The levels of acetaldehyde, ethanol and ion leakage were indices that contributed most to distinguish ripening from senescence. The increase made in levels of acetaldehyde and ethanol suggests fermentative metabolism, characteristic senescence behavior, beyond the increase in ion leakage, suggests cell decompartmentalization. The fruits of Pedro Sato cultivar can not be classified as climacteric, nor as non-climacteric, because despite they ripen, they show an ethylene production peak after their ripening, and besides do not respond to exogenous ethylene. Even though Kumagai guava fruits reply to ethylene application, there was no climacteric behavior observed during CO2 and C2H4 production thus this variety can not be framed in the respiratory climacteric pattern rankings in use.
92

The changing nature of academic development: exploring student perceptions and experiences of a learning skills programme in higher education

Petrenko, Karen January 2011 (has links)
Magister Educationis - MEd / In this paper, I focus on the issue of student perceptions and experiences of a 3rd generation academic development programme in higher education. I set out to explore the issue from two perspectives: firstly from the perspective of the higher education institution’s approach to academic development, namely, a learning skills programme and a first year sociology course, and secondly from the perspective of students’ intentions, expectations and experiences of such a programme. The research questions focused on the learning priorities embedded in the curriculum of a learning skills programme at Monash University, South Africa and the learning experiences of students in this programme.The methodology used in this study includes a case study which focused on the responses of six participants from a number of African countries completing their BA degrees. Semistructured interviews held and the content analysis method was used to analyse the data. The study concludes: that the main priority of the learning skills programme is to prepare students for their university learning rather than to prepare students for the world of work i.e. it falls within Street’s (2004) academic socialization model and that the Learning Skills programme can be seen as an example of Boughey’s (2007) 3rd generation academic development programmes.The study also suggests that there is a need to explore Volbrecht’s (2003) argument on the limitations of discipline-based models of academic development, the need to examine how academic literacy is constructed and how identity and power relations intersect in this construction. It further highlights the importance of the idea of multi-literacies as put forward by Street (2004) and suggests that as practitioners we should include a consideration of these literacies in academic development programmes to improve the quality of students’ learning and meaning making.
93

SAP Based Rapid Dewatering of Oil Sands Mature Fine Tailings

Aida, Farkish January 2013 (has links)
Mature fine tailings (MFT), as a mixture of residual bitumen, sand, silt, fine clay particles and water, are a byproduct of oil sands extraction. The large volume, and poor consolidation and water release ability of MFT have been causing significant economic and environmental concerns. Therefore, several studies have been implemented on finding innovative dewatering/disposal techniques. As a result, different methods have been introduced and tested at a laboratory or a field scale, yet very few of these are commercially used in the oil sands industries. Despite the extensive research, an optimal solution has not been found due to the lack of technical or economic feasibility. In the present study, a novel approach that consists of the rapid dewatering of MFT by using a super absorbent polymer (SAP) to produce dense MFT is proposed. A comprehensive laboratory investigation on the geotechnical characteristics and behavior before and after treatment of MFT is conducted. The effects of SAP based dewatering and freeze/thaw cycles on the undrained shear strength of dewatered MFT by using a vane shear apparatus are studied. Furthermore, the ability of recycled SAP to dewater and densify MFT is assessed. Finally, this study provides the results of consolidation and hydraulic conductivity testing to evaluate the void ratio versus effective stress and hydraulic conductivity of MFT. The effects on the behavior and characteristics of MFT after amendment with usage of recycled SAP are also investigated. The results indicate that SAP has the ability to significantly dewater, densify and increase the undrained shear strength of MFT. Furthermore, when subjected to freeze/thaw cycles, the MFT dewatered with SAP shows an additional increase in strength and solid content. It is also found to be possible to regenerate the polymer (still within sachets) through light thermal drying, and the regenerated SAP can still significantly dewater and thus increase the shear strength and solid content of the MFT. In addition, the obtained high solid content affects and improves the compressibility of the material, thus resulting in low initial void ratios. On the other hand, low hydraulic permeability that is derived from low initial void ratios and consolidation is improved by the freeze/thaw process due to the interconnected voids created during the freezing process.
94

Effect of Leachate Blending on Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

Nair, Arjun January 2013 (has links)
Anaerobic digestion of the Organic Fraction of Municipal Solid Waste (OFMSW) generates a mixture of methane (CH4), carbon dioxide (CO2) and water (H2O). Beyond the field capacity the water generated is collected and recirculated as leachate in Bioreactor Landfills (BLs.) Leachate recirculation has a profound advantage on biodegradation of the Organic Fraction of Municipal Solid Waste (OFMSW) in the landfills. Mature leachate from older sections of landfills (>20 years) and young leachate were blended prior to recirculation in the ratios 3/3 mature, 3/3 young, 1/3 mature-2/3 young and 2/3 old-1/3 young and their effect on biodegradation and biogas production monitored. In addition to analysis of the effect of blending old and new leachates, the study also analyses the effect of an open vs. a closed recirculation loop and the effect of organic loading rates of OFMSW in landfills. Data collected from initial batch tests supplement column bioreactors simulating bioreactor landfills with real world OFMSW from operational landfill facilities in Ontario, Canada. The results are conclusive that the biogas generation can be improved by up to 92% by blending the leachate in an open loop recirculation system as compared to a conventional closed loop system employed in landfills today.
95

NPD processes in fast growing companies : A case study exploring the implications of organizational structure, communication and culture.

Mårtensson, Johanna, Randevik, Josefine January 2022 (has links)
This study examines how the organizational structure affects New Product Development (NPD) in mature companies that enter a fast-growing phase. A case study with interviews and a workshop was conducted in a company in south of Sweden in addition to studying the current literature. This company is currently experiencing fast growth and is therefore facing new challenges. The fast growth in the recent years has affected the NPD processes, organizational structure, culture, and communication according to its employees. The literature argues that there must be a balance between the NPD and organizational structure to ensure performance. Each organization must have a structure that complements the NPD processes to maintain high performance.   Furthermore, communication affects NPD projects' performance, and for organizations experiencing fast growth, communication has an even more significant effect on performance. Mature organizations tend to hold on to existing organizational structures and processes, which can become troublesome when entering a fast-growing phase, as fast-growing companies need to invest in the future. As the research is lacking regarding fast-growing companies, this in-depth study explores the correlation between NPD, organizational structure, communication and culture for fast-growing companies. This case study found that the internal culture positively impacts innovation, along with the need to modify the organizational structure and NPD processes as it grows, and when growing fast, communication plays a vital role. In conclusion, we can see an interconnection between organizational structure, culture, and communication, for facilitating NPD performance, where communication is the red thread that facilitates or hinders, depending on its quality.
96

Growing as a business in a mature business-to-business service industry : A case study in the Swedish energy services industry / Tillväxt i en mogen B2B service-marknad : En fallstudie inom den svenska marknaden för underhållstjänster för energiaktörer

Wang, Erik January 2019 (has links)
In the past decade, the energy markets within the European Union haveincreasingly been deregulated as a means to promote increased competition, andthereby efficiency, on these markets. As a result of this, several energy institutionshave been forced to become unbundled from their parent companies and toinstead form smaller separate entities. Contracts that previously were guaranteedare now subjected to public competition and in order to not risk decreasing in size,these companies must now find new ways to grow and generate new business. To study this, a case study was conducted at a Swedish energy servicescompany who recently has been unbundled from one of the largest Swedish gridowners. Specifically, the research focused on what companies in maturebusiness-to-business services contexts can do to increase their sales. The studywas conducted primarily through gathering qualitative interview data bothinternally and externally, but secondary data from surveys were also used. The findings indicate that the case company should focus on pursuing a combinedstrategy of market penetration and service/product penetration to increase sales.In addition, the company should continue to invest substantially into relationshipmarketing practices in order to build long-term potential for growth. Specifically,the findings indicate it should improve its communication and relationshipinvestment towards its customers. Furthermore, it should adopt appropriatestrategies to reduce the switching barriers of its prospective customers. The findings contribute to the understanding of how companies in similarsituations as the case company can act in order to drive growth. The studyprovides further empirical data in a field that has received relatively little academicattention. The author also suggests venues for future research in the concludingchapters.
97

A novel in vitro model for mature Toxoplasma gondii tissue cysts allows functional characterization of bradyzoite biology

Christiansen, Céline 31 May 2023 (has links)
Toxoplasma gondii bildet im Nerven- und Muskelgewebe seines Zwischenwirts persistente enzystierte Bradyzoiten, die Immunreaktionen und medizinischen Behandlungen entgehen. Der experimentelle Zugang zu reifen Zysten ist auf ex vivo Modelle beschränkt und die Bradyzoiten-Biologie unzureichend erforscht. Das Metabolom oder Wirtszell-Bradyzoiten-Interaktionen und Persistenzmechanismen sind mit aktuellen in vitro und in vivo Modellen schwer zu adressieren. Um dies zu ermöglichen, war es das Ziel dieser Arbeit ein in vitro Modell zur Generierung reifer T. gondii Zysten zu etablieren und zu charakterisieren. Dieses System wurde verwendet, um (1) das Metabolom von reifen enzystierten Bradyzoiten im Vergleich zu Tachyzoiten zu charakterisieren, (2) Wirtszell-Bradyzoiten-Interaktionen zu untersuchen und (3) einen Zellteilungsmarker für Bradyzoiten zu etablieren. Bradyzoiten wurden in ausdifferenzierten menschlichen Myotuben generiert und zeigten typische ultrastrukturelle Charakteristika und Antigenexpression. Die Bradyzoiten zeigten auch funktionelle Merkmale wie Resistenz gegen Pepsin, Temperatur und Antiparasitika, die von der Reifungszeit abhängig waren. Der metabolische Fingerabdruck von Bradyzoiten wurde mit Tachyzoiten mit Hilfe einer ungezielten HILIC-UHPLC / MS-basierten Metabolomik-Plattform verglichen. Während die Hemmung der Aconitase durch Natriumfluoracetat letal in Tachyzoiten wirkte, tolerierten Bradyzoiten eine längere Hemmung des Enzyms. Stabile isotopenmetabolische Markierung und pharmakologische Modulation des Wirt Lipidstoffwechsels wiesen auf eine entscheidende Rolle der Wirts Carnitinester für den Fettsäureimport und die Entgiftung der antimikrobiellen Linolsäure hin. Um einen Zellteilungsmarker auf Einzelzellebene zu entwickeln, wurden Klick-Chemie nachweisbare Nukleosidanaloga auf Toxizität in beiden Stadien und ihr jeweiliges Inkorporationsprofil untersucht. Drei der Analoga wurden ohne toxische Wirkungen in die DNA von beiden Stadien eingebaut. / Toxoplasma gondii forms persistent encysted bradyzoites inside neuronal and muscle tissue of its intermediate host, which resist immune responses and medical treatments. Experimental access to mature tissue cysts is limited to ex vivo models and the biology of bradyzoites remains understudied. Aspects like the metabolome or bradyzoite-host-interactions and mechanisms of persistence are difficult to address using current in vitro and in vivo models. To overcome these restrictions, the aim of this thesis was the establishment and characterization of an in vitro model for the generation of matured T. gondii tissue cysts. This system then should be used to (1) characterize the metabolome of matured encysted bradyzoites in comparison with tachyzoites, (2) interrogate bradyzoite-host-interactions and (3) establish a cell division marker for bradyzoites that allows studying bradyzoite heterogeneity. Encysted bradyzoites were grown in terminally differentiated human myotubes and showed typical ultrastructural hallmarks and antigen expression. These bradyzoites contained functional hallmarks like resistance to pepsin, temperature and commonly used antiparasitics that were dependent on maturation time. The metabolic fingerprint of bradyzoites was compared to tachyzoites using an untargeted HILIC-UHPLC / MS based metabolomics platform. While tachyzoites succumbed to inhibition of their aconitase by sodium fluoroacetate, bradyzoites tolerated prolonged inhibition of this enzyme. Further, stable isotope-metabolic labeling and pharmacological modulation of host lipid metabolism indicated a critical role of host carnitine esters for fatty acid import and for the detoxification of antimicrobial linoleic acid. To develop a single cell-resolved cell division marker, we screened click chemistry-detectable nucleoside analogues for toxicity on both stages and their respective incorporation profile. Three compounds labelled both bradyzoite and tachyzoite nuclei without toxic effects.
98

Magnetic Micromotors for Multiple Motile Sperm Cells Capture, Transport, and Enzymatic Release

Xu, Haifeng, Medina-Sánchez, Mariana, Schmidt, Oliver G. 22 July 2022 (has links)
An integrated system combining a magnetically-driven micromotor and a synthetized protein-based hyaluronic acid (HA) microflake is presented for the in situ selection and transport of multiple motile sperm cells (ca. 50). The system appeals for targeted sperm delivery in the reproductive system to assist fertilization or to deliver drugs. The binding mechanism between the HA microflake and sperm relies on the interactions between HA and the corresponding sperm HA receptors. Once sperm are captured within the HA microflake, the assembly is trapped and transported by a magnetically-driven helical microcarrier. The trapping of the sperm-microflake occurs by a local vortex induced by the microcarrier during rotation-translation under a rotating magnetic field. After transport, the microflake is enzymatically hydrolyzed by local proteases, allowing sperm to escape and finally reach the target location. This cargo-delivery system represents a new concept to transport not only multiple motile sperm but also other actively moving biological cargoes.
99

Ozonização catalítica do chorume proveniente do antigo aterro controlado da cidade de Guaratinguetá-SP utilizando os íons Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ e Cr3+ / Homogeneous catalytic ozonation of leachate from Guaratinguetá - SP landfill, using the ions Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ e Cr3+

Peixoto, André Luís de Castro 14 May 2008 (has links)
Durante anos, o lixo da cidade de Guaratinguetá foi aterrado e o seu produto recalcitrante não passou por nenhum tratamento físico ou mesmo químico, percolando diretamente sob o aterro. Mesmo tendo sido desativado e transformado em Parque Ecológico, o material depositado no local ao longo dos anos, continuará a ser decomposto por microrganismos e continuará a ser produzido o lixiviado como fonte de poluição ambiental. Inicialmente, fez-se a caracterização do chorume \"in natura\", demonstrando-se como fonte de matéria orgânica recalcitrante, com massa molar característica de macromoléculas (5,58 kDa e polidispersidade de 1,16), DBO não determinável pela recalcitrância molecular e/ou pela ação tóxica e DQO característica de lixiviado estabilizado (1.013 mg L-1). A fração inorgânica total, dada pela quantidade de sólidos fixos, foi de 3.670 mg L-1, valor esse 3,6 vezes maior que a fração orgânica. O estudo de tratamento do chorume, por ozonização catalítica homogênea foi desenvolvido, principalmente, pelo uso seqüencial de dois arranjos ortogonais de Taguchi, sendo o primeiro, matriz L16, para estudo exploratório dos fatores mais importantes na redução percentual da DQO. Os fatores estudados foram vazão de ozônio, concentração dos íons Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ e Cr3+, pH do meio reacional e presença/ausência de fonte de radiação UV (254 nm). Dentre os metais de transição, os íons Fe2+ e Fe3+ demonstraram-se como mais viáveis como catalisadores na geração de radicais livres hidroxilas devido à sua significância estatística (p = 0,005), e por terem maior tolerância ao descarte no meio ambiente (menor toxicidade) frente aos demais íons. Com a utilização do arranjo ortogonal L8 de Taguchi, foi possível atingir degradação máxima de DQO da ordem de 50 %. A melhor configuração dos fatores, visando aumentar o percentual de redução da DQO foi: vazão de ozônio igual a 5 L h-1 (589,9 mg h-1 O3), concentração de íon de íon ferroso igual a 10 mg L-1, concentração de íon férrico igual a 5 mg L-1 e pH 5. / During many years, the garbage of Guaratinguetá city was landfilled and its recalcitrant product was not submitted to any physical or chemical treatment, leaching directly through the area. After deactivating and transforming the landfill into an Ecological Park, the material deposited in the place by the past years, will continue being decomposed by microorganisms and will continue producing the leached one as a mean of environment pollution. Initially, the leachate \"in natura\" was characterized, demonstrating itself as a source of recalcitrant organic substance with a higher molecular size characteristic of 5,58 kDa and polidispersity of 1,16 and stabilized effluent (not determinable DBO due to molecular recalcitrance and/or toxicity and DQO of 1,013 mg L-1). The total inorganic fraction, given by the amount of total fixed solids was 3,670 mg L-1, which means 3,6 times bigger than the organic fraction. The study of leachate treatment by homogeneous catalytic ozonation was given, mainly, for the sequential use of two Taguchi\'s orthogonal arrangements, being the first, L16 design, for exploratory studies of the most important factors in the percentual reduction of DQO. The factors studied were the ozone outflow, the Fe2+, Fe3+, Zn2+, Mn2+, Ni2+ and Cr3+ ions concentration, the reaction medium pH and the presence/absence of UV radiation source UV (254 nm). Amongst the transition metals, Fe2+ and Fe3+ ions have demonstrated to be as more viable as free hydroxyl radicals catalyst due to its statistics significance (p = 0,005) and also because they have a greater tolerance to the environment discarding (less toxicity) compared to the other ions. The use of L8 Taguchi\'s orthogonal arrays gives the possibility to reach 50 % maximum COD depletion. The best factors configuration, using COD percentage reduction as experimental design response was: 5 L h-1 (589,9 mg h-1 O3) ozone outflow, 10 mg L-1 ferrous concentration, 5 mg L-1 ferric ion concentration and pH 5.
100

Barreiras econômicas na exploração em terra de campos maduros e marginais: o caso da bacia Potiguar / Economic barriers in onshore mature oil fields: the case of Potiguar basin

Batista, Pedro Barbosa Mantovani 05 October 2016 (has links)
O surgimento da Lei do Petróleo, Lei 9.478/97, abriu uma nova frente de investimentos para o capital privado. O setor de exploração e produção de petróleo, antes sob monopólio estatal, passou a ser de interesse de diversas empresas privadas. Com a supervisão da ANP, surgiram as rodadas de licitações para concessão do direito de exploração e produção de petróleo dos campos ofertados. Os campos maduros e marginais foram então uma oportunidade de fomento aos negócios de petróleo devido à necessidade de uma operação mais eficiente, porém exigindo menores investimentos e necessidade técnica específica. Esta dissertação tem por objetivo expor o panorama econômico do setor de exploração e produção de petróleo para pequenas e médias empresas que atuam na região da Bacia Potiguar, Rio Grande do Norte, a partir de pesquisas e levantamentos de dados sobre: os conceitos teóricos de campos marginais e maduros e de pequenas e médias empresas; o histórico brasileiro de produção independente de petróleo; a geografia física e humana da Bacia Potiguar; e as barreiras econômicas encontradas por pequenas e médias empresas que atuam no setor de exploração e produção de petróleo. Depois de apresentadas e justificadas todas as hipóteses, são realizadas simulações de diferentes cenários para análise da viabilidade de um empreendimento de reativação de um campo marginal de petróleo. Utilizando a metodologia de fluxo de caixa descontado, foi possível avaliar o Valor Presente Líquido, Taxa Interna de Retorno e Payback do empreendimento. A partir da análise do fluxo de caixa e da sensibilidade de algumas premissas, avaliou-se o comportamento do Valor Presente Líquido do empreendimento em função das mudanças do preço de venda do barril de petróleo, do volume de produção do campo e de outros parâmetros escolhidos. Por fim, foi feita uma comparação entre trabalhos cujos autores propuseram temas semelhantes, para efeito de comparação e comprovação da sensibilidade e viabilidade dos campos. / The emergence of the Petroleum Law, Law 9.478/97, opened a new investment front for private capital. The upstream sector, previously under state monopoly, became a focus of interest from several private companies. With the supervision of the ANP, came rounds of bidding to grant exploration and production rights to the available oil fields. Mature and marginal fields were then a development opportunity in the oil business due to the need for a leaner operation, while requiring less investment and specific technical necessity. This thesis aims to expose the economic outlook of the onshore upstream sector for small and medium-sized companies operating in the Potiguar Basin region, Rio Grande do Norte, based on research and data surveys about: the theoretical concepts of marginal and mature fields and small and medium companies; the history of Brazilian independent oil production; the physical and human geography of the Potiguar Basin as well as the economic barriers faced by small and medium-sized companies operating in the oil exploration and production sector. After the presentation and justification of all hypotheses, simulations are carried out with different scenarios for analyzing the feasibility of the reactivation of a marginal oil field. Using the discounted cash flow method, it was possible to evaluate the Net Present Value, Internal Rate of Return and Payback of the project. From the analysis of cash flow and the sensitivity of some assumptions, we evaluated the behavior of the Net Present Value due to the sale price changes of the oil barrel, the volume of oil production in the field and other chosen parameters. Finally, a comparison between other papers whose authors have proposed similar themes was made, for comparison and verification of the sensitivity and viability of the fields.

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