Combater as secas e defender as florestas a natureza nos desafios da ciência e da técnica para modernizar o Brasil (1889 a 1934)

In the first decades of 20th century the just instituted Brazilian Republic faced the challenge to modernize the country. Considering that the progress was associated with the exhaustion of the forest reserves and with climatic changes, two big issues were seen as fundamental: To Fight the Droughts and To Defend the Forests; headed by professionals who were dedicated to these ideals. This research starts from the premise that these were the main challenges enforced by nature to the Brazilian development; the general objective was delimited in the search to understand the meaning and the conception of the natural world by this group of professionals who faced the shock between modernizing the country and conserving its natural resources. Aiming to contribute with the construction of the Brazilian environmental history and to bring historical elements to the debate about the environment in the country, the author concentrates his attention to the analyses, the discussions and the actions that preceded the regulation on the use of natural resources and the implementation of the environmental legislation in Brazil, occurred in 1934. The investigation uses as methodological basis the theoretical directions of environmental history, using sources of data still little explored and valued. In such way, it is taken as starting point some published papers about this subject during the period between 1889 and 1934 in two technical magazines the Revista Brazil Ferro-Carril and the Revista do Club de Engenharia. National engineering played a basic role in this process while arguing, projecting and constructing the development. The formulated proposals, after being divulged, had fomented the interchange with other professionals and had favored the advance of ambient questions in Brazil, in the sense to preserve natural resources, to construct more harmonic relations between the society and the nature and to equate the development with the environment preservation

Desenvolvimento de bloco de vedação com barita na composição de partida para blindagem de radiação X

This work main objective is to study the use of bricks in barium X-rays rooms in order to contribute to the optimization of shielding rooms diagnosis. The work was based on experimental measurements of X-ray attenuation (40 to 150 kV), using ceramic seal bearing the incorporation of barium sulfat (BaSO4). Different formulations were studied in three different firing temperatures and evaluated for incorporation in the ceramic body. The composition of 20% of barite processed at a temperature of 950 ° C showed better physical and mechanical properties, is considered the most suitable for the purpose of this work. Were produced bricks sealing composition formulated based on that presented the best technological features. These blocks were tested physically as a building material and wall protective barrier. Properties such as visual, deviation from the square, face flatness, water absorption and compressive strength were evaluated for all the blocks produced. The behavior of this material as attenuator for X-rays was investigated by experimental results which take into account mortar manufacturers barium through the different strains and compared with the reference material (Pb). The simulation results indicated that the ceramic block barium shows excellent properties of attenuation equivalence lead taking into account the energy used in diagnostic X-ray

ELOY DE SOUZA: UMA INTERPRETAÇÃO SOBRE O NORDESTE E OS DILEMAS DAS SECAS

The thought of Eloy de Souza is studied (1873-1959), that left a significant intellectual production in the journalistic, cultural and politicial scope on the Northeast and the dilemmas of the droughts. Through the method of content analysis, his journalistic and literary speech is investigated, looking at to understand the elaboration and/ or reiteration of categories, of representations and of values; it is verified how was conceived the constitution of the political thought and which is it´s principal slopes; the parliamentary speech, present in his interventions is analyzed in plenary session, participation in commissions and in his projects, particularly in the thematic area of the droughts. It is verified that his work is built in a political and ideological perspective inserting the bourgeoisie landowner's interests and Northeastern commercial and of it´s political strata, inside the historical block of agro-industry power that has as irradiation focus the area of the coffee represented politically by the oligarchies person from São Paulo and Minas Gerais. In that sense, two crucial categories emerge: the droughts and the country, as the Northeastern and Brazilian man's synthesis, with their resistance capacity and adaptation, and their creative effort in an adverse enviroment, that Eloy de Souza started to insert in his political speech. However, the vision that he passes of the "country suffer", expresses a certain idealization of a lifestyle that corresponds to a traditional dominance, that he want´s to be reproduced. Although it looked for the solution for the drought through the modernization of the economy by the adoption of advanced methods as the irrigation, his concern went back to the conservation of the economical and cultural political hegemony of that elite. Thus, his inquietude with the process of integration of the subordinate sections, justifies his consensual speech, harmonic as organic intellectual of the agrarian-commercial bourgeoisie of the Brazilian Northeast

Mediação como instrumento de desjudicialização das questões familiares: constitucionalização do Direito de Família

The Liberal Constitutionalism emerged from the late eighteenth century, a period of major revolutions (French and American), fruit of the struggle for libertarian rights. Although the time of the first written constitutions, these were linked to mere political letters, did not provide for fundamental human rights, as it is, so only on the state organization, structure of powers, division of powers of the state and some relations between state and individuals. There was a clear division between the civil codes and constitutions, those governing private relations and acted as barriers to non-state intervention. After the Second World War, the constitutions are no longer Letters political order to establish how the human person, in order to enshrine the fundamental rights, the primacy of constitutional principles and take their normative function against ordinary legislator. Constitutional evolution gave the name of contemporary constitutionalism, based on repersonalization or despatrimonialização of Private Law, ceasing the separation of legislative civil codes and constitutions, in favor of the protection of fundamental rights of the human person. And this tendency to the Brazilian Federal Constitution of 1988 brought higher ground the dignity of the human person, the epicenter axiological legal to govern private relations, including family law. The constitutionalization of family law motivates the adoption of desjudicialização family issues, so as to respect the direio intimacy, privacy, private autonomy and access to justice. Conflictual family relationships require special treatment, given the diversity and dynamism of their new compositions. The break in the family relationship is guided in varied feelings among its members in order to hinder an end harmonic. Thus, the judiciary, through performances impositive, not to honor the power of decision of the parties, as also on the structural problems faced to operate on these cases, the environment is not the most appropriate to offer answers to the end of family quarrels. Situation that causes future demands on the dissatisfaction of the parties with the result. Before the development of the Family Law comes the need to adopt legal institutions, which monitor the socio-cultural, and that promote an effective assistance to people involved in this kind of conflict. In obedience to the private autonomy, before manifestations of volunteers involved in family mediation, among autocompositivos instruments of conflict resolution, is indicated as the most shaped the treatment of family quarrels. Remaining, then the state a minimal intervention to prevent excessive intrusion into private life and personal privacy

Ludopoiese e humanescência no educador infantil

This research has as study objective the development of humanescent experience in the process of self-formation of the teachers of the Infantile Educational Unit of the Education Center of the Federal University of Rio Grande do Norte. It has as general objective the description and analysis of how the humanscent experience of life contributes and is manifested in the children educator in his way of being, living and in his pedagogical practice. As specific objectives, the identification of the contributions of the humanescent experiences in the children educator in his way of being, living and in his pedagogical practice; the analysis of the contributions of the humanescent experiences to the children educator from the ludopoetic categories self-esteem, selfworth, self-realization, self-territory and self-connectivity. It is a descriptive study of qualitative nature understood as an existential action research that uses the principles and fundamentals of the etnomethodology and phenomenology. Sixteen teachers six that are effective teachers, six substitute teachers and 4 interns - took part in this investigation. Six humanescent experiences were carried out with them. As main tools we point out: the participative observation, the sand game, the photographic register and the semi-structured interview. The analyses were centered in the categories of the ludopoetic system, described above and referred to in the theoretical fundamentals selected for the study. From the analyses and to the answers to the objectives of the study, we make clear the following considerations: the reports of the teachers reveal that the humanescent experiences have contributed to make them more ludic, sensitive, emotional and lovely people, and this has reflected in their educational practice and has been making sense in their and their students lives. In this way, we make evident that the humanescent experiences have contributed to improve the ludopoesis of the teachers, revealing in the embodiment changes in their way of being, of living together and in their educational practice. In relation to the contributions of the humanescent experiences to the children educator from the ludopoetic categories self-esteem, selfworth, self-realization, self-territory and self-connectivity, we emphasize the following aspects: with the self-esteem, teachers have become more creative, rebuilding their possibilities of intensely experiencing the pleasure of living; in the context of selfterritory, the teachers have provided the realization of the wishes and expresson of oneself while lively interacting with the environment and with the other different territories of the educational process, in a continuous process of demarcation. Concerning the self-connectivity category, we emphasize that the teachers started to become more tuned with themselves, with the environment and with the other teachers because of the general well-being to the success of personal, pedagogical and institutional objectives, promoting a harmonic, lovely and ludic environment. Concerning the self-worth category, the teachers have valued the struggle for a school that is more committed with the search for happiness. From the self-realization, the teachers have shown self-recognition while ludic beings, playing with the beauty in their lives, allowing the flowing in its completeness, the other possibilities of analysis, the educational formation and development. We would like to emphasize that the considerations above are not over after what has been presented because of the richness of experiences revealed in the research

Controle Adaptativo Robusto para Filtros Ativos de Potência Paralelo

Conventional control strategies used in shunt active power filters (SAPF) employs real-time instantaneous harmonic detection schemes which is usually implements with digital filters. This increase the number of current sensors on the filter structure which results in high costs. Furthermore, these detection schemes introduce time delays which can deteriorate the harmonic compensation performance. Differently from the conventional control schemes, this paper proposes a non-standard control strategy which indirectly regulates the phase currents of the power mains. The reference currents of system are generated by the dc-link voltage controller and is based on the active power balance of SAPF system. The reference currents are aligned to the phase angle of the power mains voltage vector which is obtained by using a dq phase locked loop (PLL) system. The current control strategy is implemented by an adaptive pole placement control strategy integrated to a variable structure control scheme (VS-APPC). In the VS-APPC, the internal model principle (IMP) of reference currents is used for achieving the zero steady state tracking error of the power system currents. This forces the phase current of the system mains to be sinusoidal with low harmonics content. Moreover, the current controllers are implemented on the stationary reference frame to avoid transformations to the mains voltage vector reference coordinates. This proposed current control strategy enhance the performance of SAPF with fast transient response and robustness to parametric uncertainties. Experimental results are showing for determining the effectiveness of SAPF proposed control system

Técnica de controle adaptativo robusto aplicada a filtros ativos de potência e paralelo

The Methods for compensation of harmonic currents and voltages have been widely used since these methods allow to reduce to acceptable levels the harmonic distortion in the voltages or currents in a power system, and also compensate reactive. The reduction of harmonics and reactive contributes to the reduction of losses in transmission lines and electrical machinery, increasing the power factor, reduce the occurrence of overvoltage and overcurrent. The active power filter is the most efficient method for compensation of harmonic currents and voltages. The active power filter is necessary to use current and voltage controllers loop. Conventionally, the current and voltage control loop of active filter has been done by proportional controllers integrative. This work, investigated the use of a robust adaptive control technique on the shunt active power filter current and voltage control loop to increase robustness and improve the performance of active filter to compensate for harmonics. The proposed control scheme is based on a combination of techniques for adaptive control pole placement and variable structure. The advantages of the proposed method over conventional ones are: lower total harmonic distortion, more flexibility, adaptability and robustness to the system. Moreover, the proposed control scheme improves the performance and improves the transient of active filter. The validation of the proposed technique was verified initially by a simulation program implemented in C++ language and then experimental results were obtained using a prototype three-phase active filter of 1 kVA

Estratégia de controle robusto para filtro ativo paralelo sem detecção de harmônicos de correntes

Conventional control strategies used in shunt active power filters (SAPF) employs real-time instantaneous harmonic detection schemes which is usually implements with digital filters. This increase the number of current sensors on the filter structure which results in high costs. Furthermore, these detection schemes introduce time delays which can deteriorate the harmonic compensation performance. Differently from the conventional control schemes, this paper proposes a non-standard control strategy which indirectly regulates the phase currents of the power mains. The reference currents of system are generated by the dc-link voltage controller and is based on the active power balance of SAPF system. The reference currents are aligned to the phase angle of the power mains voltage vector which is obtained by using a dq phase locked loop (PLL) system. The current control strategy is implemented by an adaptive pole placement control strategy integrated to a variable structure control scheme (VS¡APPC). In the VS¡APPC, the internal model principle (IMP) of reference currents is used for achieving the zero steady state tracking error of the power system currents. This forces the phase current of the system mains to be sinusoidal with low harmonics content. Moreover, the current controllers are implemented on the stationary reference frame to avoid transformations to the mains voltage vector reference coordinates. This proposed current control strategy enhance the performance of SAPF with fast transient response and robustness to parametric uncertainties. Experimental results are showing for determining the effectiveness of SAPF proposed control system

Uma contribuição à solução do problema dos k-servos usando aprendizagem por reforço

Neste trabalho é proposto um novo algoritmo online para o resolver o Problema dos k-Servos (PKS). O desempenho desta solução é comparado com o de outros algoritmos existentes na literatura, a saber, os algoritmos Harmonic e Work Function, que mostraram ser competitivos, tornando-os parâmetros de comparação significativos. Um algoritmo que apresente desempenho eficiente em relação aos mesmos tende a ser competitivo também, devendo, obviamente, se provar o referido fato. Tal prova, entretanto, foge aos objetivos do presente trabalho. O algoritmo apresentado para a solução do PKS é baseado em técnicas de aprendizagem por reforço. Para tanto, o problema foi modelado como um processo de decisão em múltiplas etapas, ao qual é aplicado o algoritmo Q-Learning, um dos métodos de solução mais populares para o estabelecimento de políticas ótimas neste tipo de problema de decisão. Entretanto, deve-se observar que a dimensão da estrutura de armazenamento utilizada pela aprendizagem por reforço para se obter a política ótima cresce em função do número de estados e de ações, que por sua vez é proporcional ao número n de nós e k de servos. Ao se analisar esse crescimento (matematicamente, ) percebe-se que o mesmo ocorre de maneira exponencial, limitando a aplicação do método a problemas de menor porte, onde o número de nós e de servos é reduzido. Este problema, denominado maldição da dimensionalidade, foi introduzido por Belmann e implica na impossibilidade de execução de um algoritmo para certas instâncias de um problema pelo esgotamento de recursos computacionais para obtenção de sua saída. De modo a evitar que a solução proposta, baseada exclusivamente na aprendizagem por reforço, seja restrita a aplicações de menor porte, propõe-se uma solução alternativa para problemas mais realistas, que envolvam um número maior de nós e de servos. Esta solução alternativa é hierarquizada e utiliza dois métodos de solução do PKS: a aprendizagem por reforço, aplicada a um número reduzido de nós obtidos a partir de um processo de agregação, e um método guloso, aplicado aos subconjuntos de nós resultantes do processo de agregação, onde o critério de escolha do agendamento dos servos é baseado na menor distância ao local de demanda

Contribuições ao método de rastreamento de máxima potência para sistemas fotovoltaicos

The scarcity of natural resources and the search for alternative energy sources promote a rapid change in the energy world. Among the renewable energy sources, solar energy is the most promising, presenting technology of greatest growth rate nowadays. Researchers around the world are seeking ways to facilitate their progress, developing technologies with higher efficiency and lower cost. As a contribution to global progress, this master thesis proposes the development of a strategy of maximum power tracking based on perturbation and observation method for photovoltaic systems. The proposed control strategy is based on active power balance of the system, with a reduced number of sensors. It also allows the PV system to act as a regulator of the power quality at the point of commom coupling (PCC), compensating the harmonic distortion and power factor of the current netw

Índice de aromaticidade baseado na deslocalização, degenerescência e densidade (D3BIA) para acenos e moléculas homoaromáticas

The aromaticity index is an important tool for the investigation of aromatic molecules. This work consists on new applications of the aromaticity index developed by teacher Caio Lima Firme, so-called D3BIA (density, delocalization, degeneracy-based index of aromaticity). It was investigated its correlation with other well-known aromaticity indexes, such as HOMA (harmonic oscillator model of aromaticity), NICS (nucleus independent chemical shielding), PDI (para-delocalization index), magnetic susceptibility (), and energetic factor in the study of aromaticity of acenes and homoaromatic species based on bisnoradamantanyl cage. The density functional theory (DFT) was used for optimization calculations and for obtaining energetic factors associated with aromaticity and indexes HOMA and NICS. From quantum theory of atoms in molecules (QTAIM) it was obtained the indexes D3BIA, PDI and . For acenes, when the over-mentioned indexes were applied it was observed no correlation except for D3BIA and HOMA (R2=0.752). For bisnoradamantenyl dication and its derivatives, it was obtained a good correlation between D3BIA and NICS. Moreover, it was evaluated solely one of the factors used on D3BIA calculation, the delocalization index uniformity (DIU), so as to investigate its possible influence on stability of chemical species. Then, the DIU was compared with the formation Gibbs free energy of some pairs of carbocations, isomers or not, which each pair had small difference in point group symmetry and no difference among other well-known stability factors. The obtained results indicate that DIU is a new stability factor related to carbocations, that is, the more uniform the electron density delocalization, the more stable the is carbocation. The results of this work validate D3BIA and show its importance on the concept of aromaticity, indicating that it can be understood from degeneracy of atoms belonging the aromatic site, the electronic density in the aromatic site and the degree of uniformity of electron delocalization