Identificação de modelos polinomiais narx utilizando algoritmos combinados de detecção de estrutura e estimação de parâmetros com aplicações práticas

A modelagem de processos industriais tem auxiliado na produção e minimização de custos, permitindo a previsão dos comportamentos futuros do sistema, supervisão de processos e projeto de controladores. Ao observar os benefícios proporcionados pela modelagem, objetiva-se primeiramente, nesta dissertação, apresentar uma metodologia de identificação de modelos não-lineares com estrutura NARX, a partir da implementação de algoritmos combinados de detecção de estrutura e estimação de parâmetros. Inicialmente, será ressaltada a importância da identificação de sistemas na otimização de processos industriais, especificamente a escolha do modelo para representar adequadamente as dinâmicas do sistema. Em seguida, será apresentada uma breve revisão das etapas que compõem a identificação de sistemas. Na sequência, serão apresentados os métodos fundamentais para detecção de estrutura (Modificado Gram- Schmidt) e estimação de parâmetros (Método dos Mínimos Quadrados e Método dos Mínimos Quadrados Estendido) de modelos. No trabalho será também realizada, através dos algoritmos implementados, a identificação de dois processos industriais distintos representados por uma planta de nível didática, que possibilita o controle de nível e vazão, e uma planta de processamento primário de petróleo simulada, que tem como objetivo representar um tratamento primário do petróleo que ocorre em plataformas petrolíferas. A dissertação é finalizada com uma avaliação dos desempenhos dos modelos obtidos, quando comparados com o sistema. A partir desta avaliação, será possível observar se os modelos identificados são capazes de representar as características estáticas e dinâmicas dos sistemas apresentados nesta dissertação

Desempenho de um veículo flex em bancada dinamométrica de chassi

Flex-fuel vehicles are equipped with Otto Cycle internal combustion engines and have the capability of functioning with more than one type of fuel, mixed at the same tank and burned in the combustion chamber simultaneously. This sort of motorization is a world pattern due to the scarcity of petroleum, the trade of several types of fuels, technology advances and the restriction imposed to gas emissions to the atmosphere. In Brazil, the Flexfuel vehicles are a reality, specially the ones using fuel with 20 to 25% anhydrous alcohol mixed with gasoline and those that use natural gas or original liquid fuel (gasoline or hydrated ethanol). The Brazilian model Fiat Siena, the object of this present scientific investigation, is equipped with a unique electronic central capable of managing the liquid or gaseous fuels. The purpose of this research was to perform a comparative analysis in terms of performance (in terms of both potency and consumption) of a tetra-fuel vehicle - using a chassis dynamometer, operating with different fuels: common gasoline, premium gasoline, Podium gasoline, ethanol or natural gas. It became necessary to develop a bench of tests and trials procedures, as well as to know the functioning of the electronic management of the vehicle under analysis. The experiments were performed at the automotive laboratory in CTGAS-ER (Center of Gas Technologies and Renewable energies) at the light of Brazilian standard ABNT, NBR 7024: Light on-road vehicles - measurement of fuel consumption. The essay results on specific fuel consumption using common gasoline, premium gasoline and Podium gasoline have shown similar results, both for urban and road driving cycles

Simulação numérica da interação entre uma nuvem incidente de vórtices e uma aerofólio através do método dos vórtices

The study of aerodynamic loading variations has many engineering applications, including helicopter rotor blades, wind turbines and turbo machinery. This work uses a Vortex Method to make a lagrangian description of the a twodimensional airfoil/ incident wake vortex interaction. The flow is incompressible, newtonian, homogeneus and the Reynolds Number is 5x105 .The airfoil is a NACA 0018 placed a angle of attack of the 0° and 5°simulates with the Painel Method with a constant density vorticity panels and a generation poit is near the painel. The protector layer is created does not permit vortex inside the body. The vortex Lamb convection is realized with the Euler Method (first order) and Adans-Bashforth (second order). The Random Walk Method is used to simulate the diffusion. The circular wake has 366 vortex all over positive or negative vorticity located at different heights with respect to the airfoil chord. The Lift was calculated based in the algorithm created by Ricci (2002). This simulation uses a ready algorithm vatidated with single body does not have a incident wake. The results are compared with a experimental work The comparasion concludes that the experimental results has a good agrement with this papper

Obtenção de antioxidante a partir de derivados do LCC

Cashew-nut-shell-liquid (CNSL) is a phenolic oil that hás been due its their antioxirsion properties for use in fuels. The present work develops a method to the conversion of hidrogenated cardanol, that is the main component of the CNSL, in a compound with similar chacteristics to antioxidants used in products from petroleum. The antioxidants wasd obtained by exhaustive alkylation of the compound with tert-butyl chloride. After completing the optimization of several reaction steps, the product 2,4,6 tri-tert-butyl (pentadecylphenol) was obtained for the first tima. Characteeization and determination of physico-chemical properties were realized too, as well as wasd developed a study for check your application as an oxidative inhibitor by the molecular modeling. Estimation of process evalution was executed as well, where a rapid and practical computational methodology was utilizated in projects of the fine chemistry. The research showed satisfactory results and it could be concluded that the commercialization of this chemical products is feasible

Tratamento de materiais contaminados com bifenilas policloradas (PCBS) via extração convencional e fluído supercrítico

The decontamination of the materials has been subject of some studies. One of the factors that it increases the pollution is the lack of responsibility in the discarding of toxic trash, as for example the presence of PCB (Polychlorinated Biphenyls) in the environment. In the Brazilian regulations, the material contaminated with PCB in concentrations higher than 50 ppm must be stored in special places or destroyed, usually by incineration in plasma furnace with dual steps. Due to high cost of the procedure, new methodologies of PCBs removal has been studied. The objective of this study was to develop an experimental methodology and analytical methodology for quantification of removal of PCBs through out the processes of extractions using supercritical fluid and Soxhlet method, also technical efficiency of the two processes of extraction, in the treatment of contaminated materials with PCBs. The materials studied were soils and wood, both were simulated contamination with concentration of 6.000, 33.000 and 60.000 mg of PCB/ kg of materials. Soxhlet extractions were performed using 100 ml of hexane, and temperature of 180 ºC. Extractions by fluid supercritical were performed at conditions of 200 bar, 70°C, and supercritical CO2 flow-rate of 3 g/min for 1-3 hours. The extracts obtained were quantified using Gas chromatography-mass spectrometry (GC/MS). The conventional extractions were made according to factorial experimental planning technique 22, with aim of study the influence of two variables of process extraction for the Soxhlet method: contaminant concentration and extraction time for obtain a maximum removal of PCB in the materials. The extractions for Soxhlet method were efficient for extraction of PCBs in soil and wood in both solvent studied (hexane and ethanol). In the experimental extraction in soils, the better efficient of removal of PCBs using ethanol as solvent was 81.3% than 95% for the extraction using hexane as solvent, for equal time of extraction. The results of the extraction with wood showed statistically it that there is not difference between the extractions in both solvent studied. The supercritical fluid extraction in the conditions studied showed better efficiency in the extraction of PCBs in the wood matrix than in soil, for two hours extractions the obtain percentual of 43.9 ± 0.5 % for the total of PCBs extracted in the soils against 95.1 ± 0,5% for the total of PCBs extracted in the wood. The results demonstrated that the extractions were satisfactory for both technical studied

Aproveitamento de subprodutos da industrialização do escargot

The waste in the industries of escargot processing is very big. This is composed basically of escargot meat out of the commercialization patterns and the visceras. In this context, there is a need to take advantage to the use of these sub-products. A possibility should be drying them and transforming them in a certain form to be reused. Than, the present work has the objective of studying the reutilization of the sub-products of the escargot industrialization for by means of drying process. The samples were transformed in pastes, through a domestic processor for approximately 1 minute and compacted in trays of aluminum without perforations with three different heights (5 mm, 10 mm and 15 mm). The drying was accomplished in a tray dryer with air circulation and transverse flow at a speed of 0,2 m/s and three temperature levels (70°C, 80°C and 90ºC). A drying kinetics study was accomplished for the obtained curves and for the heat and mass transfer coefficients using experimental procedures based in an experimental planning of 22 factorial type. Microbiological and physiochemical analysis were also accomplished for the in nature and the dehydrated sub-products. In the drying process, it was observed the great importance of the external resistances to the mass transfer and heat in the period of constant tax influenced by the temperature. The evaporation taxes indicated a mixed control of the mass transfer for the case of the thickest layers. As already expected, the drying constant behavior was influenced by the temperature and thickness of the medium, increasing and decreasing. The statistical analysis of the results, in agreement with the factorial planning 22, showed that the fissures, the shrinking of the transfer area and the formation of a crust on the surface might have contributed to the differences between the practical results and the linear model proposed. The temperature and the thickness influenced significantly in the answers of the studied variables: evaporation tax and drying constant. They were obtained significant statistical models and predictive ones for evaporation tax for the meat as well as for the visceras

Purificação da glicerina bruta obtida a partir da transesterificação do óleo de algodão

The crude glycerine is a raw material that can be used in a wide variety of products. Even with all the impurities inherent in the process of being obtained, the crude glycerin is already in a marketable product. However, the market is much more favorable to the commercialization of purified glycerine. The glycerin is a byproduct gotten from the process of transesterification of waste oils and fats in the production of biodiesel. More recently, the deployment of the new Federal Law of Brazil, related to the implementation of energy resources, forces, from 2008, the increase of 2% biodiesel in diesel common with prospects for 5% (B5). Therefore, it is indispensable that new routes of purification as well as new markets are developed. The objective of this work was to purify, through ion exchange, the crude glycerin, obtained from the reaction of transesterification of cottonseed oil. The cottonseed oil was characterized as the fatty acid composition and physical-chemical properties. The process of ion exchange was conducted in batch. In this process were used strong cation, low anion resins and a mixed resin used to de-ionize water. The purified glycerin was characterized as the content of metals. Tests were performed with activated charcoal adsorption, and for this, it was made tests of time contact with coal as well as quantity of coal used. The time of activation, the amount of the activation solution, the contact time of the glycerol solution in resins, the amount and type of resin applied were evaluated. Considering the analysis made with activated charcoal, when the glycerin solution was treated using the resins individually it was observed that in the conditions for treatment with 10 g of resin, 5 hours of contact with each resin and 50 mL of glycerin solution, its conductivity decreased to a cationic resin, increased to the anionic resin and had a variable value with respect to resin mixed. In the treatment in series, there was a constant decrease in the conductivity of the solution of glycerin. Considering two types of treatment, in series and individually, the content of glycerol in glycerin pre-purified solution with the different resins varied from 12,46 to 29.51% (diluted solution). In analysis performed without the use of activated charcoal, the behavior of the conductivity of the solution of glycerin were similar to results for treatment with activated charcoal, both in series as individually. The solution of glycerin pre-purified had a glycerol content varying from 8.3 to 25.7% (diluted solution). In relation to pH, it had a behavior in accordance with the expected: acid for the glycerin solution treated with cationic resin, basic when the glycerin solution was treated with the anionic resin and neutral when treated with the mixed resin, independent of the kind of procedure used (with or without coal, resins individually or in series). In relation to the color of the glycerin pre-purified solution, the resin that showed the best result was the anionic (colorless), however this does not mean that the solution is more in pure glycerol. The chromatographic analysis of the solutions obtained after the passage through the resins indicated that the treatment was effective by the presence of only one component (glycerol), not considering the solvent of the analysis

Jambolão (Syzygium cumini) desidratado por liofilização e secagem em leito de jorro: avaliação do impacto do processo de secagem e caracterização do potencial funcional do produto final

Tropical fruits have been extensively studied due to their functional potential attributed to the presence of natural bioactive compounds. The exotic fruit jambolan (Syzygium cumini) has been reported for its appreciable amount of phenolic compounds, especially anthocyanins and antioxidant capacity. Nevertheless, there are hardly any derived jambolan products in the Brazilian market. In addition to that, considerable volumes of fruit are lost due to their high perishability. Dried fruits have become an important fruit market segment due to its weight and volume reduction and decreased transportation and storage costs. Thus, this study evaluated the jambolan pulp submitted to spouted bed drying (JLJ) and lyophilization (JLI), besides assessing the drying impact on the final product. In order to achieve this, the process performance was calculated and compared, as well the physicochemical and bioactive characteristics (moisture, water activity (aw), solubility, hygroscopicity, density, color, structure through images obtained by scanning electron microscopy (SEM), concentration of bioactive (total phenolic compounds (TPC), anthocyanins, proanthocyanidins and ascorbic acid) and antioxidant activity. The results showed drying efficiency higher than 60% for both products and that JLJ group showed higher moisture and water activity when compared to the JLI group (p<0.05). The two types of drying were able to produce stable final product in the microbiological point of view, given that both showed aw < 0.6. The final products exhibited high solubility (73.7 to 81.6%) and low hygroscopicity (9.8 to 11.6%), desirable characteristics for dehydrated foods. Despite the losses caused by drying, the dried jambolan pulp by both methods showed high TPC (468.6 to 534.0 mg GAE/100g dm), anthocyanins (from 491.9 to 673.4 mg. eq. cyanidin-3-glicoside/100g dm), proanthocyanidins (66.9 to 76.6 mg QTE/g dm) and ascorbic acid (156.4 to 186.8 mg/100 g dm). Taken together, the results of this study reveal spouted dried and freeze dried jambolan pulp as bioactive-rich natural products with suitable physicochemical and functional characteristics to be used as food ingredients. The data also demonstrate the drying techniques as rational strategies for the exploitation of the exotic fruit jambolan

Estudo da reidratação do feijão verde (Vigna unguiculata L. Walp) desidratado por micro-ondas com e sem pré-tratamento osmótico

The green bean has organoleptic and nutritional characteristics that make it an important food source in tropical regions such as the Northeast of Brazil. It is a cheap source of protein and important for nutrition of rural population contributing significantly in subsistence farming of the families from Brazil s northeast. It is consumed in entire region and together with the dry meat and other products composes the menu of typical restaurants, being characterized as an important product for economy of Northeast. The green bean is consumed freshly harvested and has short cycle, being characterized as a very perishable food, which hampers your market. The drying method is an alternative to increase the lifetime and provide a reduction volume of this product making easier your transportation and storage. However is necessary to search ways of drying which keep the product quality not only from the nutritional standpoint but also organoleptic. Some characteristics may change with the drying process such as the coloring, the rehydration capacity and the grains cooking time. The decrease of drying time or of exposure of the grains to high temperature minimizes the effects related with the product quality loss. Among the techniques used to reduce the drying time and improve some characteristics of the product, stands out the osmotic dehydration, widely used in combined processes such as the pretreatment in drying food. Currently the use of the microwaves has been considered an alternative for drying food. The microwave energy generates heat inside of materials processed and the heating is practically instantaneous, resulting in shorter processing times and product quality higher to that obtained by conventional methods. Considering the importance of the green beans for the Northeast region, the wastefulness of production due to seasonality of the crop and your high perishability, the proposal of this thesis is the study of drying grain by microwaves with and without osmotic pretreatment, focusing on the search of conditions of processes which favor the rehydration of the product preserving your organoleptic characteristics. Based on the analysis of the results of osmotic dehydration and dielectric properties was defined the operating condition to be used in pretreatment of the green bean, with osmotic concentration in saline solution containing 12,5% of sodium chloride, at 40°C for 20 minutes. The drying of green bean by microwave was performed with and without osmotic pretreatment on the optimized condition. The osmotic predehydration favored the additional drying, reducing the process time. The rehydration of dehydrated green bean with and without osmotic pretreatment was accomplished in different temperature conditions and immersion time according to a factorial design 22, with 3 repetitions at the central point. According to results the better condition was obtained with the osmotically pretreated bean and rehydrated at a temperature of 60°C for 90 minutes. Sensory analysis was performed comparing the sample of the green bean in natura and rehydrated in optimized conditions, with and without osmotic pretreatment. All samples showed a good acceptance rate regarding the analyzed attributes (appearance, texture, color, odor and taste), with all values above 70%. Is possible conclude that the drying of green bean by microwave with osmotic pretreatment is feasible both in respect to technical aspects and rehydration rates and sensory quality of the product

A etnomatemática em uma cerâmica da região do Seridó/RN

This work has as objective to describe mathematical knowledge used as tools in the manufacture and marketing of tiles of red ceramic by potters of the Currais Novos village/ RN, located 250 km from the capital of Rio Grande do Norte. For us to reach our objective, we rely on conceptions ambrosianas of Ethnomatematics, besides of the qualitative research in an ethnographic approach. In the empirical part of the research, that went it accomplishes in the period from 2009 to 2012 in the Currais Novos Village, we support the following tools for data collection, semi-structured interviews, field diary, photographs, audio recordings and participant observations. In the analysis of the collected data, we can conclude that there are mathematical knowledge in the management of manufacture and marketing of tiles, often different from the academic mathematics, mainly in the wood cube, on cube of the clays, in the handler with the measures time, the count method , in the arrangement of tiles, in the preparation of the ceramic mass and sale of tiles. Theses knowledge were described and analyzed in the light of the theoretical Ethnomatematics, also supported in official documents, such as Parameters Nacional Curriculares. The analyzes of these knowledge generated subsidies for elaboration of an educational product - a proposal of didactic sequence destined to the Teaching of Mathematics in Elementary and Middle levels for the community schools and region, this proposal is in the Appendix to this work

Uma proposta metodológica do ensino da química para alunos da Zona Rural :O estudo do leite

La enseñanza desarrolló, así como los métodos y las técnicas de enseñar. Aquí el he/she piensa un método instrucción, en que el estudiante está más de un oyente simple: además la parte íntegra, él se llama para intervenir continuamente, mientras tocando una parte ancho, interactivo e involucrando, del contextualização del tema para ser trabajado -inclusivo, asocie día a día al his/her y contextual al programa de la disciplina de Química, hasta la manera como ese tema debe explorarse. La leche, el tema pone en correlación al origen del grupo de los estudiantes seleccionados, fue explorado, dentro de una visión sistémica, bajo el punto de vista de la composición de las propiedades de la industrialización y de la comercialización. Buscando prever los caminos de la construcción y organización del conocimiento de los estudiantes, se usó el modelo de administración mental de Antoine de La Garranderie y la teoría de aprender de Ausubel. El conocimiento de los estudiantes se supervisó antes, durante y al final de las actividades desarrolladas, práctica que permitió verificar la evolución y el nivel de asimilación conceptual de éstos con respecto al tema en el estudio. El análisis de los resultados obtenidos, después de la aplicación de una encuesta que contempla veinte asuntos, todo pertinentes al tema, demostró un nivel del uso sobre el promedio, lo que merecido la pena el método de enseñanza propuesta

Caracterização da caprinocultura nas microrregiões da chapada do Apodi e de Angicos do Estado do Rio Grande do Norte

The objectives of this study were to characterize the goat production systems and to identify the factors limiting the production chain and develop solutions to improve the goat industry in the Rio Grande do Norte State, Brazil. One hundred and sixty two questionnaires were applied to goat farmers looking for productive, economic and social information about the utilized systems in the micro regions of Chapada do Apodi and Angicos. The majority producers interviewed were male, aging from 31 to 50 years old, attended elementary school, associated to farm organizations and living with his family on farm. Their main concerns are feeding the heard and animal theft. Their average farmlands areas range from 11 to 50 hectares. Goat meat is the main production in Chapada do Apodi whereas milk is produced by farmers in Angicos micro region. The majority of goat production works with an extensive system, with low technological inputs. It was detected that the meat and milk production as the marketing of goat products is not well conducted. Other point to be improved is to increase the meat and dairy goat products to be available for consumers. Goat systems for meat and milk production has great to potential for this micro regions, although public policies for an organized supply chain is needed

Caracterização e modelagem dos sistemas de produção de caprinos leiteiros

The objectives of this research were characterizing the dairy goat production systems and model it using linear program. On the first step of this research, the model was developed using data from farms that was affiliated in the ACCOMIG/Caprileite, used a similar dairy goat production systems and have a partnership program with Universidade Federal de Minas Gerais . The data of research were from a structured questionnaire applied with farmers and monitoring of production systems during a guided visit on their farms. The results permitted identify that all farms were classified as a small and have a intensive production system. The average herd size had 63.75 dairy goats on lactation; it permits a production of 153, 38 kg of goat milk per day. It was observed that existing more than one channel of commercialization for the goat milk and their derivative products. The data obtained, on the first step of this research, was used to develop a linear program model. It was evaluated in two goat production systems, called P1 and P2. The results showed that the P1 system, with an annual birth and lactation during approximately 300 days was the best alternative for business. These results were compared with a mixed (beef and dairy) goat system in the semiarid region, which indicated merged with both systems. Therefore, to achieve profits and sustainability of the system, in all simulations it was necessary a minimum limit of funding of U.S. $ 10,000.00; this value permit earning of U.S. $ 792.00 per month and pay the investment within 5 years

Desenvolvimento e teste de um modelo estatístico de identificação das proporções de água produzida em zonas de produção de um campo maduro de petróleo

This study investigates the chemical species produced water from the reservoir areas of oil production in the field of Monte Alegre (onshore production) with a proposal of developing a model applied to the identification of the water produced in different zones or groups of zones.Starting from the concentrations of anions and cátions from water produced as input parameters in Linear Discriminate Analysis, it was possible to estimate and compare the model predictions respecting the particularities of their methods in order to ascertain which one would be most appropriate. The methods Resubstitution, Holdout Method and Lachenbruch were used for adjustment and general evaluation of the built models. Of the estimated models for Wells producing water for a single production area, the most suitable method was the "Holdout Method and had a hit rate of 90%. Discriminant functions (CV1, CV2 and CV3) estimated in this model were used to modeling new functions for samples ofartificial mixtures of produced water (producedin our laboratory) and samples of mixtures actualproduced water (water collected inwellsproducingmore thanonezone).The experiment with these mixtures was carried out according to a schedule experimental mixtures simplex type-centroid also was simulated in which the presence of water from steam injectionin these tanks fora part of amostras. Using graphs of two and three dimensions was possible to estimate the proportion of water in the production area

Algoritmo treansgenético na solução do problema do Caixeiro Viajante

The Traveling Purchaser Problem is a variant of the Traveling Salesman Problem, where there is a set of markets and a set of products. Each product is available on a subset of markets and its unit cost depends on the market where it is available. The objective is to buy all the products, departing and returning to a domicile, at the least possible cost defined as the summation of the weights of the edges in the tour and the cost paid to acquire the products. A Transgenetic Algorithm, an evolutionary algorithm with basis on endosymbiosis, is applied to the Capacited and Uncapacited versions of this problem. Evolution in Transgenetic Algorithms is simulated with the interaction and information sharing between populations of individuals from distinct species. The computational results show that this is a very effective approach for the TPP regarding solution quality and runtime. Seventeen and nine new best results are presented for instances of the capacited and uncapacited versions, respectively