Repositório RCAAP

In 2018, the National Curricular Common Base (NCCB) was released, which aims to determine the skills (general and specific), habilities and essential learning that must be developed during each stage of basic education. In this document, among the changes that occurred, a skill regarding understanding Cartographic Projections in the Mathematics subject to be studied in High School was added. Thinking about how the NCCB skills can be worked in the classroom, a group of teachers, including the author of this dissertation, has been writing a didactic material, called Livro Aberto de Matemática (LAM), in which the topic Cartographic Projections is approached, as recommended by the NCCB. Thus, this dissertation aims to investigate the knowledge of mathematics teachers (and undergraduates) about Cartographic Projections. To achieve this goal, we designed and implemented a workshop held remotely, which had synchronous and asynchronous activities. During the workshop, we presented the chapter created on Cartographic Projections, discussed some activities with the participants and used four questionnaires and the recordings of the synchronous meetings as an instrument for data collection. Through a qualitative analysis of the answers given in the first questionnaire available, most participants reported not feeling confident to teach Cartographic Projections.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

The disturbances resulting from power swing (OP) cause, in a harmful way to the electrical power system (SEP), acceleration or delay in the rotor angle between synchronous generators in relation to synchronous frequency, in addition to variation between load balancing and generation. The consequences of the OP phenomenon at the transmission line terminals (LTs) are fundamentally instabilities in voltage and current values, exposing the distance protection (ANSI 21) to incorrect actions and, consequently, causing a possible blackout. Thus, in order to inhibit undue occurrences of the ANSI 21 distance function, the detection of the OP phenomenon, as well as actuation, is corroborated through the blocking function (ANSI 68). Three-terminal lines are often a cost-saving option in planning, as there is a reduction in the cost associated with having to build a substation at the connection point. However, the complexity and challenge in the elaboration of protection projects, especially distance protection, increases. Therefore, with the purpose of analyzing the occurrence of the OP phenomenon, as well as promoting the development of algorithm tests of functions 21 and 68 in three-terminal lines, the characterization of the main quantities that are affected during oscillations were applied in the present work. of potency. For the recognition and verification of the generated signals and, therefore, the decision making for the blocking function (ANSI 68), the algorithms of three methods were implemented, Concentric Characteristics Method (MCC), Double Blinder Method (MDB) and Electric Center Voltage Variation Method (MVTCE), which are compared. The implementation of the methods was carried out in MATLAB® and simulation of the cases in SIMULINK. The results obtained show that the methods for OP blocking, when applied to three-terminal lines, present failures, especially when the three terminals have sources, therefore, they cannot be applied to this type of line.

This work contains the study of basic topologies of hybrid converters classified as serious impedance, the converters presented here are said to be hybrid because they associate two technologies, the switched converters and the linear amplifiers, the objective here is to extract the best in each structure, to get from amplifiers responses with high speed and without distortion (high fidelity) and from switched converters the ability to bring greater energy density to the load. There are several ways to associate both Technologies. The switched converter, the load and the linear amplifier can be placed in parallel or in series, the linear amplifier may or may not have a power source, when the amplifier does not have a power source, linear uses energy from the switched converter. This dissertation deals with a series association and with the sourceless linear amplifier, with these characteristics the linear amplifier can be observed as an impedance. A general study carried out on both technologies is presented. On the MOSFET amplifiers, the characteristics (structure, form of construction and the physical phenomena present), the forms of operation (operation points such as cuts, triode and saturation, identifying at this moment what is the linear region and how to maintain the operation in this region), the limitations (such as threshold voltage, capacitive and resistive couplings and the dependence of the gain in relation to the drain current) and finally a methodology for projects of MOSFET amplifiers controlled by operational amplifiers. The design of each of the hybrid converters is demonstrated followed by an analysis carried out through the simulations responses, at the end the experimental design is presented, for which the Buck converter was chosen, then an analysis of the results of this experiment follows.

The development of new nanocarriers for the so-called third-generation photosensitizers (FS) has contributed significantly to the evolution of photodynamic therapy (PDT). Due to its maximum absorption at wavelengths within the phototherapeutic window range (600-800 nm), low photochemical degradation, and adequate singlet oxygen quantum yield (ФΔ), magnesium phthalocyanine (MgPc) is considered a promising FS for use in PDT. However, its high hydrophobicity and formation of aggregates decrease its photodynamic activity in a physiological environment. Thus, the encapsulation of MgPc in nanostructures becomes necessary to improve its bioavailability and increase its phototherapeutic activity. From these considerations, the main objective of this work is to encapsulate MgPc in polymeric micelles obtained from block copolymers based on maltoheptaose (MH) and evaluate its photodynamic activity. By way of comparison, the encapsulation of MgPc in poly-ɛ-caprolactone (PCL) nanocapsules was also performed. The physicochemical characterization of the nanostructured systems (MH-b-PS@MgPc, MH-b-PMMA@MgPc, and PCL@MgPc) was carried out by determining the values of hydrodynamic diameter, polydipersion index, zeta potential, the total content of MgPc, encapsulation efficiency and physical stability over time by LUMiSizer. The photodynamic activity of the nanoparticles was evaluated by monitoring the photochemical degradation reaction of the chemical suppressor 1,3-diphenylisobenzofuran (DPBF). The kinetic profile of in vitro release of MgPc from the nanostructures and the toxicity and biodistribution of the nanocarriers against the nematodes Caenorhabditis elegans were also evaluated. The nanostructures presented nanometric sizes, low polydispersion indices (which confirm the homogeneity of the systems), negative zeta potential with high modulus values, and encapsulation efficiency above 95%. Analysis by LUMiSizer revealed that the polymeric micelles are highly stable in aqueous medium, with an estimated physical stability of three years. Evaluating the photodynamic activity of the nanoparticles it was concluded that polymeric micelles containing FS are capable of generating singlet oxygen at satisfactory levels for use in PDT, with Ф� values close to those of unencapsulated MgPc. The nanostructures present a sustained FS release profile, with biexponential model kinetics. The toxicity study showed that the nanoparticles cause a small reduction in the larval development of C. elegans, but do not induce lethality when the worms are exposed to low concentrations, and that they are mostly located in intestinal cells. Considering these results, it is concluded that nanostructured systems based on maltoheptaose are promising carriers for MgPc, with potential use in PDT.

CPFL Energia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq

The environmental need in the use of renewable energy sources, just as the reduction in greenhouse gas emissions put electric vehicles as the great solution in the transportation market for the coming years. Parallel to the advent of these vehicles arises the need for a better use of energy in the converters used. Therefore, this work proposes the development of an isolated converter for the application in more efficient, smaller and lighter chargers. The proposed topology presents high efficiency when switching at the resonance point and excludes the need for a control system when operating at constant voltage gain. The converter design methodology for a 3300 W application is presented. A technique is proposed to track the resonance and ensure operation with maximum efficiency of the topology. Computer simulations and prototype tests are performed in order to prove the effectiveness of design and proposed technique. The results obtained were satisfactory, reaching efficiency above 98 % for operation at nominal load. In addition, the consumption of computational resources required to perform the real-time tracking is analyzed.

The power systems operation has been mostly based on centralized solutions. In the recent time however, the power system economic models are changing because of the inclusion of new private participants in the system and policies that support 100 percent renewable energy (RE) integration. This new paradigm increases the power systems complexity considering the autonomy of the individual participants. Non transparency in data exchange among operators also limits the effectiveness of the centralized solutions, making centralized operation more challenging. As a result, the motivation to develop decentralized solution that allows individual operator to effectively manage its operation while interacting with other operators becomes necessary for secure and reliable operations of the entire grid. Furthermore, the classical multiarea operation problem has been studied by many authors using some conventional piece-wise linearized mathematical methods. Alternatively, where there is need to address complex and non-convex functions, the metaheuristic methods are considered suitable. However, despite this capability, the existing metaheuristic methods have been limited to either using centralized models or not considering multiple autonomous participants in their decision-making frameworks. Consequently, this research develops two novels decentralized multiarea economic dispatch models based on metaheuristic optimization (MO) to manage the operation of some transmission system operators (TSOs) and private aggregators (PAs) of RE resources including battery storages in an interconnected multiarea power systems context. The first model is a semi-decentralized (SD) model developed to attract wider inclusion of PAs in the transmission systems by allowing them to maximize profits. The second model is a fully decentralized (FD) model developed to coordinate the operation the PAs with the TSOs to preserve their baselines. The proposed models allow to determine the effective integration of autonomous PAs in the transmission systems (TS) and their co-operation with the TSOs. The objective of both models is to minimize the total operation cost of the system by effectively coordinating the TSOs and PAs operations. The TSOs and PAs evaluate their operational uncertainties and determine the power reserves considering the best and worst-case scenarios of the uncertain variables, thus enabling the resulting models to be solved in three stages using select metaheuristic methods (MM). To preserve the ownership of TSOs and PAs, the MM efficiently utilizes separate population sets to solve the operations of the areas in parallel in a two-layer operation approach, allowing the TSOs and PAs to achieve near-optimal operations, independently. Case studies are performed on a modified Nigerian 330 kV 39-bus transmission systems having three TSOs each with three PAs to demonstrate the effectiveness of the proposed models. The simulation results obtained showed the performance superiority of the novel models over their centralized counterpart model.

The network society is increasingly complex and dynamic. In it, all types of interaction are transformed, and the law must be able to protect them. Likewise, the risks are increasing and are related to the set of actors and factors interacting in globalization, leading to catastrophic events. Hence, instruments are needed to adequately protect and repair these disasters that ultimately reach the Judiciary; it is in this context that public civil action stands out. Thus, this investigation examines public civil action as a special procedure to protect environmental law in the context of the network society and its limitations from a critical-reflexive perspective. For this, this study is based on philosophical hermeneutics, limiting itself to understanding the procedural insufficiency of public civil action and the necessary construction of correct answers in the face of the ideals of the Democratic State of Law. Given the theme and its limitation, this paper aims to investigate the effectiveness of public civil action as a procedure for the protection and repair of the right to disasters, considering its imprisonment to the rational liberal-individualistic paradigm and necessary construction of correct answers in its universe in order to answer the following question: What are the conditions for it to be possible to speak of the effectiveness of public civil action in procedural and substantial aspects as a locus of repair of anthropogenic environmental disasters, such as in the cases of the Mariana and Brumadinho environmental disasters? To answer the problem, methodologically, this study employed a phenomenological-hermeneutic approach, not speaking of a method per se, but of a way of being-in-the-world based on what Heidegger and Gadamer teach, with language being a condition for the insertion of the subject in this world. The procedure consisted of bibliographical and documental research and employed judiciary records and abstracts as the technique. Furthermore, philosophical hermeneutics were used as the basis with Streck’s Critical Hermeneutics of Law as a conductor, according to Heidegger and Gadamer. Based on this configuration, this work is structured in two chapters divided into three subchapters, concluding that legislative change is necessary for the procedural aspect. As long as the change does not occur in such a way as to reorganize the structure of the lawsuit, it will continue to perish when faced with cases such as those addressed herein. Substantially, the condition for being able to discuss effectiveness is the guarantee of correct answers, and this is because judicial decisions must be complete, coherent, and handed down by impartial individuals who respect its dual dimension.

The energy transition intensifies two limitations verified on traditional transmission cost allocation (TCA) methods employed around the world: 1) lack of coordination between transmission pricing and load evolution, and 2) lack of efficient signals to guide the generation expansion throughout the transmission system. This work presents a novel dynamic framework that overcomes such limitations, making tariff adjustments that reflect the responsibility of each user on transmission investment. The process undertaken by the framework for the transmission tariff formation captures two important aspects: the load evolution at each system bus and the optimal generation necessary to minimize the electrical losses into the transmission network. In terms of consumption, adjustments are made to raise the tariffs at buses with load growth and to reduce the tariffs at those buses with load decline. In relation to generation, the framework rewards generators that contribute to minimize the electrical losses, through the calculation of benefits that work as discounts in their tariffs. Both aspects are innovative and direct contributions to the power sector, as they are attributes not verified on traditional TCA methods. Furthermore, the transmission tariff formation is integrated with the reconfiguration of distribution networks that respond to this tariff, in order to minimize the global cost of distribution utilities. Thus, the work presents an integrated structure that allows analyzing the feedback between transmission tariffs and agents of electricity consumption and generation. The novel dynamic framework stimulates a more distributed load growth in the power system and incentivizes that generators increase their capacity at suitable locations in the system. The integration between transmission tariffs and distribution networks guarantees the raise of regulatory fairness between these power sector segments. Hence, the framework increases the economic efficiency of transmission tariffs, through individual, proportional and coordinated tariff adjustments, also ensuring the full recovery of the total transmission cost. The framework modeling is generic, which allows its application with any TCA method, with different power systems, and with distinct cost structures. Therefore, the framework is able to contribute to the provision of efficient economic signals, promoting a better use of system resources and launching new possibilities of tariff integration and operational coordination.

The current study has had the aim to understand the emancipation process of the consumers groups and of rural producers linked to the TECSOL incubator and supported by the solidarity economy. In this context, this study had as its theoretical framework: substantive economy (Polanyi), solidarity economy, and emancipation. To reach this goal the following objectives have been set: i) present the historic process of the University Network of Technology Incubators for Community Solidarity Economy (ITCPs); ii) report the track record of the TECSOL incubator, of the Rede Bem da Terra consumer network, and of the Rede Bem da Terra producer network; iii) identify the prevailing categories in relation to the process of emancipation at TECSOL, as well as of the consumer and the producer groups; iv) build the analytical representation of the emancipation process of incubated groups in a solidarity economy perspective. To reach this aim, research with an interpretivist theoretical contribution of a qualitative nature was carried out. The research field was the Technology Incubator for Solidarity Economy Enterprises (TECSOL), which is linked to the University Network of Technology Incubators for Community Solidarity Economy. The data collection techniques have been: theme-based oral history interviews, and non-participant observation. Besides interviews, documents have been used. Interviews were carried with members of the TECSOL Incubator, Rede Bem da Terra’s Consumer Group, and Rede Bem da Terra’s Germinar rural Producer Group. Data have been systematized by categories that arose in the field, where content analysis was carried out. Concerning the results, the categories emerging from the interviews made with participants of TECSOL, of the Consumer Group, and of the Germinar rural Producer Group have been interlinked, resulting in the following categories: technical processes; critical conscience; decision-making process; collective conscience; education; horizontal organizational process; political dimension; and conscious consumption. The construction of the analytical representation was carried through the interlinking of a priori (theory) and a posteriori (empirical) categories, resulting in the following categories: ecology of productivities; collective conscience; critical conscience; social dimension; political dimension; economic dimension; democratic decision-making; solidarity; education; social management; ecology of temporalities; trans-scale ecology; horizontal organizational process; awareness; dialogue; conscious consumption. From the analyses it was verified that the categories are interconnected like leitmotivs, being linked to each other towards the emancipation process of incubated groups in a solidarity economy perspective; namely, no category overlaps the other and what likely happens is that one of them is more prominent during the process. Furthermore, the process (the road to emancipation) is understood not to be linear and still; it shall depend on the time and the context of each group. Finally, it should be noted that this dissertation had no intention of being conclusive or of creating an emancipation model like a roadmap and that nothing prevents new categories from arising and being used for other groups and collectives which have as their core the criticism of the capitalist system.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq

Dithiocarbamates (DTC) fungicides have characteristics related to high instability when in the presence of moisture and oxygen, thus requiring special preparation of the sample to be worked on, as well as the development and validation of an individual method for analysis of the generated compounds. In this work, an individual method for the determination of DTC in yerba mate was miniaturized and validated, based on the acid hydrolysis of the sample in the presence of tin chloride II, purification of the extract and subsequent analysis of the carbon disulfide (CS2) generated using gas chromatography–mass spectrometry (GC-MS). The optimization conditions were evaluated through miniaturization in the sample extraction process, based on the amount of sample, volume of extracting solvent and acid solution and the stirring time during the hot bath. These conditions were compared to those already described in the literature. As it is a complex matrix, an extract purification step was carried out through the dispersive solid phase extraction (d-SPE) process using primary and secondary amine (PSA) as sorbents, graphitized carbon (GCB) in addition to magnesium sulfate (MgSO4) as a drier. For the method validation study, the following parameters were evaluated: linearity, matrix effect, limit of detection (LOD) and limit of quantification (LOQ), precision and accuracy. Within the results obtained in the validation study, the LOD was established at 0.05 mg L-1 CS2, and the LOQ at 0.1 mg kg-1 CS2. The coefficient of determination (r2) obtained through the analytical curves was r2 > 0.99. The results obtained through the precision study were acceptable values with RSDr ≤11.2% and RSDpi ≤19.4% and, as well as the recoveries, in the range of 71.3 to 118.2%. The matrix effect calculated was -5.1%, which is within acceptable values for determining trace levels of contaminants. The validation parameters are in accordance with those described in DG-SANTE (2019) and, therefore, suitable for the determination of DTC in yerba mate. The validated method proved to be faster, simpler, and cheaper when compared to the traditional method described in the literature and quite effective for determining DTC in yerba mate. The miniaturized method was applied to 58 samples produced and sold in southern Brazil, 3 produced in Brazil and exported to Uruguay, and 4 produced in Argentina and sold in Brazil. Of the 65 herb samples that were used for the monitoring study, 33.8% had detectable levels of CS2, and 14% had concentration levels higher than the LOQ.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES