Síntese de catalisadores do tipo LaNixFe1-xO3 como precursores catalíticos para reação oxidação parcial do metano

Nickel-bases catalysts have been used in several reform reactions, such as in the partial oxidation of methane to obtain H2 or syngas (H2 + CO). High levels of conversion are usually obtained using this family of catalysts, however, their deactivation resulting from carbon deposition still remains a challenge. Different approaches have been tested aiming at minimizing this difficulty, including the production of perovskites and related structures using modern synthesis methods capable of producing low cost materials with controlled microstructural characteristics at industrial scale. To establish grounds for comparison, in the present study LaNixFe1-xO3 (x=0, 0.3 or 0.7) perovskites were prepared following the Pechini method and by microwave assisted self-combustion. All samples were sub sequently calcined at 900 °C to obtain the target phase. The resulting ceramic powders were characterized by thermogravimetric analysis, infrared spectroscopy, X ray diffraction, specific area and temperature programmed reduction tests. Calcined samples were also used in the partial oxidation reaction of methane to evaluate the level of conversion, selectivity and carbon deposition. The results showed that the calcined samples were crystalline and the target phase was formed regardless of the synthesis method. According to results obtained by Rietveld refinement, we observed the formation of 70.0% of LaNi0.3Fe0.7O3 and 30.0% of La2O3 for samples LN3F7-900- P, LN3F7-900-M and 41,6% of LaNi0.7Fe0.3O3, 30.7% of La2NiO4 and 27.7% of La2O3 for samples LN7F3-900-P and LN7F3-900-M.Temperature-programmed profiles of the LaNiO3 sample revealed the presence of a peak around 510 °C, whereas the LaFeO3 sample depicted a peak above 1000°C. The highest l evel of methane conversion was obtained for LaNiO3 synthesized by the Pechini method. Overall, catalysts prepared by the Pechini method depicted better conversion levels compared to those produced by microwave assisted self-combustion

Influência do método de síntese e caracterização de pós compósitos de NiO- Ce1-xEuxO2-δ para anodos catalíticos de células a combustível

Fuel cells are electrochemical devices that convert chemical energy into electricity. Due to the development of new materials, fuel cells are emerging as generating clean energy generator. Among the types of fuel cells, categorized according to the electrode type, the solid oxide fuel cells (SOFC) stand out due to be the only device entirely made of solid particles. Beyond that, their operation temperature is relatively high (between 500 and 1000 °C), allowing them to operate with high efficiency. Another aspect that promotes the use of SOFC over other cells is their ability to operate with different fuels. The CeO2 based materials doped with rare earth (TR+3) may be used as alternatives to traditional NiO-YSZ anodes as they have higher ionic conductivity and smaller ohmic losses compared to YSZ, and can operate at lower temperatures (500-800°C). In the composition of the anode, the concentration of NiO, acting as a catalyst in YSZ provides high electrical conductivity and high electrochemical activity of reactions, providing internal reform in the cell. In this work compounds of NiO - Ce1-xEuxO2-δ (x = 0.1, 0.2 and 0.3) were synthesized from polymeric precursor, Pechini, method of combustion and also by microwave-assisted hydrothermal method. The materials were characterized by the techniques of TG, TPR, XRD and FEG-SEM. The refinement of data obtained by X-ray diffraction showed that all powders of NiO - Cex-1EuxO2-δ crystallized in a cubic phase with fluorite structure, and also the presence of Ni. Through the characterizations can be proved that all routes of preparation used were effective for producing ceramics with characteristics suitable for application as SOFC anodes, but the microwave-assisted hydrothermal method showed a significant reduction in the average grain size and improved control of the compositions of the phases

Síntese e caracterização de TaC e óxido misto de tântalo e cobre nanoestruturados a partir do precursor oxálico de tântalo através de reações gás-sólido e sólido-sólido a baixa temperatura

The research and development of nanostructured materials have been growing significantly in the last years. These materials have properties that were significantly modified as compared to conventional materials due to the extremely small dimensions of the crystallites. The tantalum carbide (TaC) is an extremely hard material that has high hardness, high melting point, high chemical stability, good resistance to chemical attack and thermal shock and excellent resistance to oxidation and corrosion. The Compounds of Tantalum impregnated with copper also have excellent dielectric and magnetic properties. Therefore, this study aimed to obtain TaC and mixed tantalum oxide and nanostructured copper from the precursor of tris (oxalate) hydrate ammonium oxitantalato, through gas-solid reaction and solid-solid respectively at low temperature (1000 ° C) and short reaction time. The materials obtained were characterized by X-ray diffraction (XRD), Rietveld refinement, Scanning Electron Microscopy (SEM), Spectroscopy X-Ray Fluorescence (XRF), infrared spectroscopy (IR), thermogravimetric (TG), thermal analysis (DTA) and BET. Through the XRD analyses and the Reitiveld refinement of the TaC with S = 1.1584, we observed the formation of pure tantalum carbide and cubic structure with average crystallite size on the order of 12.5 nanometers. From the synthesis made of mixed oxide of tantalum and copper were formed two distinct phases: CuTa10O26 and Ta2O5, although the latter has been formed in lesser amounts

O efeito das substituições no comportamento tático e no rendimento físico dos jogadores profissionais de futebol de alto rendimento

O objetivo deste estudo foi analisar o impacto das substituições no comportamento tático e no rendimento físico de jogadores profissionais de futebol da primeira liga inglesa. Foram analisadas 40 substituições diretas de jogadores das posições de médios centro, extremos e avançados, ocorridas durante a segunda parte dos jogos. Para captar o comportamento tático individual dos jogadores foram utilizadas duas variáveis compostas: a variação da distância de cada jogador ao seu locus de referência espacial e a distribuição espacial dos deslocamentos de cada jogador (heat map). A partir destas variáveis foram calculadas a média, desvio padrão e coeficiente de variação, assim como duas medidas de entropia - que permitem mensurar a regularidade e a variabilidade/imprevisibilidade do comportamento tático individual de cada jogador. Para captar o rendimento físico dos jogadores foi utilizada a distância total percorrida e a distância percorrida em cinco categorias de intensidade. Os médios centro e os avançados substituídos apresentaram uma diminuição da imprevisibilidade no período inicial do jogo comparativamente com o período anterior à substituição. Foi também evidente a tendência para ocorrer uma diminuição do rendimento físico nos jogadores substituídos entre o período inicial de jogo e o período imediatamente anterior à substituição. Da mesma forma, para os médios e os extremos, os jogadores quando entraram na qualidade de substitutos apresentam também um maior rendimento físico que os jogadores substituídos. O jogador da posição do substituto/substituído, que permaneceu em campo apresentou também menor rendimento físico que os substitutos. Estes resultados sugerem que as motivações táticas justificam as substituições de médios centro e avançados e as motivações físicas justificam as substituições de médios centro e extremos.

Práticas de observação e análise de jogo

A Observação e Análise é uma área em crescimento nos últimos anos. Hoje em dia, a presença de um departamento de Observação e Análise nos clubes é visto como essencial uma vez que, no futebol de alto rendimento, os jogos estão cada vez mais equilibrados, sendo decididos muitas vezes por pormenores. Neste sentido existe uma maior necessidade de inclusão de equipas técnicas multidisciplinares com o objetivo de melhorar o rendimento da equipa e alcançar o sucesso. As equipas de topo devem controlar ao máximo todos os fatores que influenciam o rendimento dos jogadores e, a Observação e Análise de jogo é um deles. Este relatório surge no âmbito do estágio realizado no Sport Lisboa e Benfica, mais concretamente no departamento de Observação e Análise do Benfica LAB, na época desportiva 2014/2015. Encontra-se dividido em três partes fundamentais. A Área 1 (Prática Profissional) foca-se na exposição detalhada das formações específicas que nos foram proporcionadas bem como todas as tarefas operacionais e complementares realizadas ao longo do estágio, subjacentes a um departamento de Observação e Análise. A segunda parte é referente à Área 2 (Inovação e Investigação) – desenvolvimento de um estudo de investigação que carateriza as ações técnico-táticas individuais do Sport Lisboa e Benfica por posição (posto específico) com o objetivo de averiguar diferenças significativas entre épocas desportivas. Concluiu-se a existência de diferenças significativas. As posições que apresentaram o maior número de diferenças entre épocas desportivas foram as posições médio defensivo e primeiro avançado. Finalmente, a última parte deste relatório centra-se na Área 3 (Relação com a Comunidade). São explicados detalhadamente todos os procedimentos da organização e dinamização de um evento vocacionado para a formação de agentes que intervém direta ou indiretamente na Observação e Análise de Jogo.

Sistema de informação para a representação e deteção de modelos de jogo no futebol

Dissertação de Mestrado, Engenharia Elétrica e Eletrónica, Instituto Superior de Engenharia, Universidade do Algarve, 2014

Plano de marketing para a loja "Banana Chiclete"

Mestrado em Marketing

Síntese e caracterização de CuNb2O6 e CuNbC através de reação sólido- sólido e gás- sólido a baixa temperatura

The refractory metal carbides have proven important in the development of engineering materials due to their properties such as high hardness, high melting point, high thermal conductivity and high chemical stability. The niobium carbide presents these characteristics. The compounds of niobium impregnated with copper also have excellent dielectric and magnetic properties, and furthermore, the Cu doping increases the catalytic activity in the oxidation processes of hydrogen. This study aimed to the synthesis of nanostructured materials CuNbC and niobium and copper oxide from precursor tris(oxalate) oxiniobate ammonium hydrate through gas-solid and solid-solid reaction, respectively. Both reactions were carried out at low temperature (1000°C) and short reaction time (2 hours). The niobium carbide was produced with 5 % and 11% of copper, and the niobium oxide with 5% of copper. The materials were characterized by X-Ray Diffraction (XRD), Rietveld refinement, Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF), infrared spectroscopy (IR), thermogravimetric (TG) and differential thermal analysis (DTA , BET and particle size Laser. From the XRD analysis and Rietveld refinement of CuNbC with S = 1.23, we observed the formation of niobium carbide and metallic copper with cubic structure. For the synthesis of mixed oxide made of niobium and copper, the formation of two distinct phases was observed: CuNb2O6 and Nb2O5, although the latter was present in small amounts

Efeitos do tratamento superficial da sílica ativa com soluções de ácidos nítrico e fosfórico em propriedades do concreto

The addition of active silica potentially improves the quality of concrete due to its high reactivity and pore refinement effect. The reactivity of silica is likely related to its charge density. Variations in surface charge alter the reactivity of the material consequently affecting the properties of concrete. The present study aimed at investigating variations in the charge density of silica as a function of acid treatments using nitric or phosphoric acid and different pH values (2.0, 4.0 and 6.0). Effects on concrete properties including slump, mechanical strength, permeability and chloride corrosion were evaluated. To that end, a statistical analysis was carried out and empirical models that correlate studied parameters (pH, acid and cement) with concrete properties were established. The quality of the models was tested by variance analysis. The results revealed that the addition of silica was efficiency in improving the properties of concrete, especially the electrochemical parameters. The addition of silica treated using nitric acid at pH = 4.0 displayed the best cement performance including highest strength, reduced permeability and lowest corrosion current

Apoio aéreo nas operações de contrassubversão

O presente Trabalho de Investigação Aplicada está subordinado ao tema “Apoio Aéreo nas Operações de Contrassubversão”. O desenvolvimento tecnológico alterou o paradigma da guerra, passando de guerra clássica ou convencional para guerra irregular. Os beligerantes dos conflitos deixaram de ser exércitos convencionais e passaram a ser milícias, grupos criminosos e organizações terroristas. O foco de atuação é redirecionado para a população em vez de componente militar do Estado opositor. Os elementos das forças irregulares provocam elevadas baixas nas tropas terrestres. Para reduzir esse número de baixas, existe uma ferramenta eficaz ao dispor das forças terrestres, apoio aéreo. O Teatro de Operações do Afeganistão envolveu vários Países na luta contra a insurgência, implicando uso de diferentes meios e táticas para combater a ameaça. Com esta investigação, pretende-se enunciar o papel do apoio aéreo nas operações de contrainsurgência no Afeganistão. A presente investigação é baseada no método de abordagem do problema indutivo, tendo como estudo de caso o Teatro de Operações do Afeganistão. Com esta investigação conclui-se, que o apoio aéreo desempenha papel fundamental no apoio à manobra terrestre. É uma ferramenta versátil e tem um tempo de resposta reduzido. Pode ser utilizado nas operações ofensivas e para garantir proteção da força nos deslocamentos. Por fim, o apoio aéreo é um elemento relevante nas operações psicológicas, uma vez que, basta a sua presença para intimidar o inimigo.

O Emprego de Solípedes nas Forças Militares Portuguesas durante a 1.ª Guerra Mundial em França

O seguinte Trabalho de Investigação Aplicada tem como objetivo descrever de que forma foram integrados e como foram empregues os solípedes nas forças militares portuguesas durante a 1.ª Guerra Mundial em França, nomeadamente no Corpo Expedicionário Português, acompanhando a evolução doutrinária relativa aos quadros orgânicos e aos quantitativos de solípedes previstos e empregues, desde o momento em que foi sugerida a participação de Portugal no conflito até às forças portuguesas se encontrarem em França. O período em análise está inserido na 1.ª Guerra Mundial, decorrida entre 1914 e 1918, que provocou uma profunda alteração na forma de combater que até então se fazia. Este período é caracterizado por um contraste entre as táticas e técnicas que tinham sido utilizadas no passado e que não se ajustavam à nova realidade do armamento, levando a que as diferentes unidades e formações necessitassem de se adaptar, surgindo dessa forma alterações na forma como os solípedes eram empregues. Para a realização desta investigação teve-se como referência o método de investigação histórica, sendo analisada, numa abordagem diacrónica, a evolução da orgânica das unidades mobilizadas e a sua atividade operacional, e através de uma abordagem sincrónica, as variáveis atuantes como a falta de recursos ou as adaptações à organização britânica e as respostas que os portugueses encontraram no desenvolvimento da sua missão no Corpo Expedicionário Português.

Quantificação de Fases Cristalinas de Incrustações em Colunas de Produção de Petróleo pelo Método Rietveld

The scale is defined as chemical compounds from inorganic nature, initially soluble in salt solutions, which may precipitate accumulate in columns of production and surface equipment. This work aimd to quantify the crystalline phases of scale through the Rietveld method. The study was conducted in scale derived from columns production wells in development and recipients of pigs. After collecting samples of scale were performed the procedure for separations of inorganic and organic phase and preparation to be analyzed at the X-ray Laboratory. The XRD and XRF techniques were used to monitor whether identifying and quantifying crystalline phases present in the deposits. The SEM technique was used to visualize the morphology of the scales and assess their homogeneity after the milling process. XRD measurements were performed with and without milling and with or without the accessory spinner. For quantify crystalline phases the program DBWStools was used. The procedure for conducting the first refinement was instrumental in setting parameters, then the structural parameters of the phases in the sample and finally the parameters of the function profile used. In the diffraction patterns of samples of scale observed that the best measures were those that passed through the mill and used the accessory spinner. Through the results, it was noted that the quantitative analysis for samples of scale is feasible when need to monitor a particular crystalline phase in a well, pipeline or oil field. Routinely, the quantification of phases by the Rietveld method is hardwork because in many scale was very difficult to identify the crystalline phases present

Determinação da toxicidade aguda e caracterização de risco ambiental do herbicida Roundup (glifosato) sobre três espécies de peixes

Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests

Análise da estrutura e transporte do zooplâncton no estuário do Rio Caravelas (Bahia-Brasil) através do uso do zooscan

Spatial-temporal dynamics of zooplankton in the Caravelas river estuary (Bahia, Brazil). The survey was conducted in order to describe the zooplankton community of the estuary Caravelas (Bahia, Brazil), to quantify and relate the patterns of horizontal and vertical transport with the type of tide (neap and spring) and tidal phase (flood and ebb). Zooplankton samples were collected with the aid of a suction pump (300L), filtered in plankton nets (300μm) and fixed in saline formalin 4%. Samples were collected at a fixed point (A1), near the mouth of the estuary, with samples taken at neap tides and spring tides during the dry and rainy seasons. Samples were collected for 13 hours, at intervals of 1 hour in 3 depths: surface, middle and bottom. Simultaneous collection of biological, we measured the current velocity, temperature and salinity of the water through CTD. In the laboratory, samples were selected for analysis in estereomicroscope, with 25 groups identified, with Copepoda getting the highest number of species. The 168 samples obtained from temporal samples were subsampled and processed on equipment ZooScan, with the aid of software ZooProcess at the end were generated 458.997 vingnettes. 8 taxa were identified automatically, with 16 classified as a semi-automatic. The group Copepoda, despite the limited taxonomic refinement ZooScan, obtained 2 genera and 1 species identified automatically. Among the seasons dry and wet groups Brachyura (zoea), Chaetognatha, and the Calanoid copepods (others), Temora spp., Oithona spp. and Euterpina acutifrons were those who had higher frequency of occurrence, appearing in more than 70% of the samples. Copepoda group showed the largest percentage of relative abundance in both seasons. There was no seasonal variation of total zooplankton, with an average density of 7826±4219 org.m-3 in the dry season, and 7959±3675 org.m-3 in the rainy season, neither between the types and phases of the tides, but seasonal differences were significant recorded for the main zooplankton groups. Vertical stratification was seen for the major zooplankton groups (Brachyura, Chaetognatha, Calanoida (other), Oithona spp, Temora spp. e Euterpina acutifrons). The scale of this stratification varied with the type (square or tide) and tidal phase (flood or ebb). The instantaneous transport was more influenced by current velocity, with higher values observed in spring tides to the total zooplankton, however, there was a variation of this pattern depending on the zooplankton group. According to the data import and export of total zooplankton, the outflow of organisms of the estuary was higher than the input. The results suggest that the estuary of Caravelas may influence the dynamics of organic matter to the adjacent coast, with possible consequences in National Marine Park of Abrolhos

Projeto, construção e análise de um prototipo vibracional em escala de bancada aplicável ao tratamento de água de produção de petróleo bruto, mediante inovadora operação híbrida de adsorção e auto-flotação

A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity