Sistema de instrumentação de baixo custo compatível com o LabVIEW

A procura de soluções de baixo custo é hoje em dia, uma exigência quando se fala em aquisição de equipamentos para empresas e instituições. Essa procura torna-se ainda mais premente quando as soluções disponíveis comercialmente são demasiado caras e não traduzem por completo os objectivos para as quais se destinam. Com o trabalho desenvolvido nesta tese de Mestrado pretendeu-se criar uma versão low cost de um sistema de medição de deformações em estruturas, para ser utilizado pelo laboratório de Engenharia Civil da Universidade da Madeira. Fazendo uso da filosofia low cost utilizada para o desenvolvimento do sistema de medição, utilizou-se um Arduíno Duemilanove como plataforma de interface com o LabVIEW, em detrimento das dispendiosas placas de aquisição de dados. De forma a tornar o sistema de medição funcionalmente mais completo, e aproveitando-se a interface criada, bem como os deflectómetros digitais pertencentes à instituição, criou-se um sistema de medição personalizado que consegue medir simultaneamente os dados de três extensómetros e os valores medidos por dois deflectómetros. Foram efectuados diversos testes no equipamento desenvolvido, permitindo não só a calibração do mesmo, mas também um estudo das suas capacidades e limitações. Por fim, e de forma a demonstrar a versatilidade da interface criada, procedeu-se a um teste final onde foi possível verificar-se que era possível obter-se uma taxa de amostragem de cerca de 408,3Hz, caso o sistema fosse utilizado para a aquisição de um só valor de tensão analógico.

Análise do custo-benefício de sistemas de cobertas em edificações comerciais para o clima de Natal/RN visando eficiência energética

This research consists in studying the influence of the various type of construction systems of roofs with their energy efficiency as well as on the cost benefit for the commercial buildings on the temperatures condition of the city of Natal/RN. The main goal of this research is to analyze the cost benefit of the construction systems of roofs available on the market, taking into consideration the energy efficiency of the commercial buildings artificially air conditioned in order to be used by the projectors and to be adequated to the temperatures condition of the city of Natal/RN. The method of valuation of the cost benefit of roof systems consists in six steps: Features and simulation of the reference building; Analyze of sensitivity; Analyzes, features and simulation of alternatives of roof construction systems; Analyze of the cost of implementation; Analyze of the benefits of the alternatives comparing to the base case; And finally the analyze of the cost benefit. The model type chosen as reference was stores with pre molded buildings and system of roof with fiber ciment and ceiling . The thermal results showed the influence of the roof system on the energy efficiency of the building. The Final results of the simulations of the alternatives comes to a conclusion that the absortance is the variable that presents the best cost benefit relation and the reduction on the thermal transmittance still has limitations because of the high cost

Desempenho operacional de um protótipo “aerossolo”

It is been a great deal of interest the studying of the operational performance of tractors and its machinery especially in work conditions. The present study had as objective to evaluate the operational performance of an Aerossolo prototype tracked with a Valtra BM100 4x2 TDA, with the engine power of 73.6 kW (100 cv). The prototype equipment is a drag type, hydraulically commanded, with telescopic heading for longitudinal adjustment, two lateral sections with 28 knifes in each one of them, concrete ballasts, wheels of transport and aggregate breaker coil. The work was conducted in the Department of Agricultural Engineering of the UNESP, Jaboticabal Campus, in a randomized blocks design, factorial 3 x 3, with four repetitions. The nine studied treatments were a combination for three ballast conditions (0; 960 and 1,307 kg) and three angles of the sections (0 degrees; 7 degrees and 14 degrees). The results indicate an increase in operational consumption (liters per hectare) of 32.4% in relation to the concrete ballast addition, and a 26.8% in relation to the angle variation between sections. The working depth, traction force and power demands were higher with the increases in the concrete ballast and the angle variation between sections.

Avaliação do crescimento e do custo da alimentação do pacu (Piaractus mesopotamicus Holmberg, 1887) submetido a ciclos alternados de restrição alimentar e realimentação

Avaliaram-se os efeitos da utilização de ciclos alternados de restrição alimentar e realimentação no crescimento do pacu, durante o período de engorda, e a viabilidade desta prática na produção comercial da espécie. Juvenis foram distribuídos em três tanques e submetidos a diferentes manejos alimentares, constituindo os tratamentos: A (alimentado ad libitum), B (restrição alimentar de 4 semanas, realimentado por 9 semanas) e C (6 semanas de restrição alimentar, realimentado por 7 semanas), em um total de 13 semanas por ciclo (4 ciclos experimentais). No final de cada ciclo alimentar, 20 peixes de cada tratamento foram amostrados e os dados biométricos registrados. Os valores obtidos para peso, comprimento total e fator de condição (K) foram submetidos a ANOVA e as médias comparadas pelo teste de Duncan. Os resultados mostraram que o tratamento C é o mais indicado somente para outono/inverno, promovendo maior crescimento, menor custo com ração, baixa conversão alimentar e maior receita líquida parcial. Entretanto, durante as estações mais quentes do ano (primavera/verão) outros programas de alimentação devem ser testados, utilizando-se períodos mais curtos de restrição alimentar. Quando se tratou da produção anual, o tratamento A respondeu melhor em termos de biomassa produzida, apesar do maior gasto com alimentação, visto que, com o aumento da temperatura, o crescimento dos peixes dos demais tratamentos ficou prejudicado.

A Fruticultura Irrigada de pequenos produtores no Baixo-Açu: Uma análise da eficiência de custo

This work has as an objective analyze the efficiency of producers costs of the irrigation Project Baixo-Açu , and identify the determining factors of this efficiency. To achieve these targets it was estimated, in a first stage, a frontier of costs by the method, non parametric of Data Envelopment Analysis-DEA, and measured the stakes of efficiency producers. On the second stage, it was utilized the Tobit regression pattern, estimating an inefficiency function of costs, and were indentified the associated factors of resources waste. Among the results found it was noticed the existence of a high waste of resources, that represent more than 54% of effective cost. Among the factors with the highest wastes are: energy, herbicides, defensives and chemical fertilizers. In a general way, the producers presented low efficiency level and, only, two, of seventy-five researched, achieved the frontier of costs minimization. These results reveal, in a certain way, that the producers in irrigated fruit growing in the project Baixo-Açu don t seek to minimize the production costs. It was still noticed, that the reduction of resources waste, and this way the inefficiency of costs, is associated with the agriculturalist education, his experience in agriculture, his access to the technical assistance and credit

Concentração da posse da terra e o programa nacional de crédito fundiário - uma análise para o estado do Rio Grande do Norte, 2006 - 2012

O objetivo do trabalho é propor um estudo sobre a relação do Programa Nacional de Crédito Fundiário - PNCF, no estado do Rio Grande do Norte, e sua concentração fundiária. Ou seja, se o PNCF está sendo direcionado, para as microrregiões que apresentam maior índice de concentração, de acordo com o índice de Gini, e se as áreas adquiridas através do crédito fundiário estão emergindo nestas microrregiões. Para isto, o estudo levantou a hipótese de que o PNCF no estado do Rio Grande do Norte não está sendo conduzida, de modo a reduzir a concentração fundiária, dentre as microrregiões do estado. Ou seja, não existe correlação entre o índice de Gini, da concentração fundiária, e as áreas adquiridas através do programa. Além disso, o trabalho buscou realizar uma discussão da literatura sobre os programas de reforma agrária assistida pelo mercado. Apresentando os autores que são exaltadores do modelo e das suas potencialidades, atrelando as causas dos problemas levantados como sendo de ordem técnica e operacional, onde os principais autores desta linha são: Van Zyl, Kirsten & Binswanger, (1996), Deininger & Binswanger, (1999). Têm-se também a apresentação da posição dos autores adeptos as políticas fundiárias pautadas na dinâmica e liberação dos mercados de terras, mas que visam contribuir com estudos que permitam uma redução para o custo elevado e a sua incapacidade de abarcar a esfera social, em decorrência do pagamento á vista e a preço de mercado aos donos das terras, são eles: De Janvry & Sadoulet (2002), Gordillo (2002), Banerjee (1999), Jaramillo (1998) e Burki & Perry (1997). Todavia, apresentou-se a corrente de autores que ressalta a natureza socialmente agressiva da Reforma Agrária Assistida pelo Mercado (RAAM), sendo os seus principais contribuidores: El-Ghonemy (2001); Barros, Schwartzman & Sauer (2003); Borras Jr. (2006, 2003 e 2003a); Garoz et al. (2005); Sauer & Pereira (2006); Pereira (2005, 2006 e 2010); Sauer (2010); Lahiff, Borras Jr. & Kay (2007). Em sequência, o trabalho apresentou a transição e características dos programas de acesso à terra, no Brasil, a partir da década de 1990, bem como, alguns indicadores do PNCF, no Brasil e o estado do Rio Grande do Norte. Apresentou-se também os indicadores da concentração fundiária, no Brasil e no estado. Através dos dados do Censo Agropecuário de 2006 foi possível calcular o índice de Gini da distribuição fundiária nas microrregiões no estado do Rio Grande do Norte. Com os dados fornecidos pela Secretaria de Estado de Assuntos Fundiários e de Apoio à Reforma Agrária - SEARA mostrou-se a distribuição das linhas de crédito do PNCF e as áreas adquiridas, entre os anos de 2006 e 2012. Por fim, o valor do coeficiente de correlação simples (r) igual a (0,2865), que com base no teste bilateral da distribuição de t de Student chegou-se no resultado para T calculado no valor de (1,2333), que ao ser comparado com o valor de T crítico igual a (2,898), com 17 graus de liberdade, a um nível de significância de 1%, pode aceitar a hipótese de partida, ou seja, que o PNCF não estava sendo direcionado para diminuir a concentração fundiária no estado

Custo de energia elétrica em cultura do feijoeiro irrigado por pivô central, afetado pelo manejo da irrigação e sistemas de cultivo

O objetivo deste trabalho foi analisar o consumo e o custo de energia elétrica em cultura do feijoeiro irrigado por pivô central, cultivar IAC-Carioca, submetida a dois manejos de irrigação: TENS - tensiometria; TCA - balanço hídrico-climatológico, baseado no tanque Classe A; e dois sistemas de cultivo em Latossolo Vermelho: PD - plantio direto; PC - plantio convencional, no ano de 2002. A pesquisa foi desenvolvida na Área Demonstrativa e Experimental de Irrigação - ADEI da FCAV/UNESP, Câmpus de Jaboticabal - SP. O consumo de energia elétrica do sistema de irrigação foi monitorado, e seu custo, analisado para dois grupos tarifários: A e B, sendo os preços do kWh dos sistemas tarifários de energia elétrica obtidos na CPFL (Companhia Paulista de Força e Luz). Os tratamentos em que o manejo da irrigação foi realizado pelo método do tanque Classe A, ocasionaram os maiores consumos e custos de energia elétrica, em relação aos tratamentos em que o manejo foi realizado por tensiometria; entre os sistemas de plantio, não foram observadas diferenças. A tarifa Horo-Sazonal (verde e/ou azul), com desconto, foi a melhor opção para os quatro tratamentos.

Custo social de oportunidade na trajetória de acesso ao ensino superior: o caso dos ingressantes na UFRN nos vestibulares de 2006 a 2010

Access is a problem of higher education in Brazil that has existed since the formalization of this has occurred since the installation of the Portuguese court in Brazil in 1808. Only 10% of young people between 18 and 24 years of age attending this level of education in 2000, arriving in 2010 just 15%, far from that determined the National Education Plan in 2001, triple that percentage by the year 2010. In addition, a majority of seats of public HEIs is populated by students from the private network, especially in high-demand courses. In this context, this study aims to identify the costs related to the trajectories of students who were successful in the vestibular UFRN editions from 2006 to 2010. Presents an overview of higher education in Brazil, a brief history of vestibular, as well as new forms of access, and some of the policies to expand such access, highlighting the argument Inclusion UFRN. Focusing on the theme of the paper presents the concepts of opportunity costs and social. After collecting data through a questionnaire and consultation of databases COMPERVE was developed to search for a descriptive and analytical, with the participation of 3,995 students, of whom 1642 (41.1%) had completed secondary education in schools public, and 2,078 (52%) in private schools. The profile indicates that 90% are single, about 50% are 21 years of age, are white and female. In the course of preparation for college entrance exams, 80% chose the course during or after completion of the last year of high school, and almost 70% said they had started preparing at that time. Findings related to the costs involved with this preparation indicate that, in most cases there were school fees and disbursements and workshops, and the purchase of books and other materials, with parents primarily responsible for this cost, the amount disbursed each month was up $ 300 for 64% of respondents and only 7% of them exceeded $ 1,000, the major non-financial costs were characterized by the following resignations: job opportunities (24%) or temporary work (20%) courses of languages (26%), leisure activities (48%), leisure travel (43%), and parties and / or shows (54%). Of social investments by the government, stand out in the tax waiver scholarships for study in private institutions, grant exemption from the registration fee of vestibular, the preparatory courses UFRN, and seminars by COMPERVE / UFRN with networks of high school. From the junction of the opportunity costs (private costs) and social costs (public costs), a new concept: the social opportunity cost, which measures the combined efforts of families and government to finance the opportunity to access higher education of an individual. This concept can and should be incorporated as a strategic vector for the sake of democratic university, which reflects the social model that is sought

Custo-efetividade da terapia compressiva no processo de cicatrização de úlceras venosas

Analytical study of therapeutic nonrandomized intervention type, intra-group controlled, with the aim of analyzing the cost-effectiveness of compression therapy with manipulated Unna boot in relation to conventional therapy in the healing of venous ulcers (VU) of patients treated in ambulatory clinic. The study population was composed by patients with VU treated by angiologists in Surgical Clinic Ambulatory of the Onofre Lopes University Hospital (HUOL) with a sample of 18 patients. It obtained the assent of the HUOL Ethics in Research Committee (Protocol 276/09). Data collection was performed over a period of four months by the own master's student and 34 nursing students, through the application of the research instrument in the admission of patients to the study and in the ten subsequent evaluations, performed at the time of changing Unna boot, weekly, for a maximum period of 10 weeks. The data were analyzed with SPSS 15.0 software, using descriptive and inferential statistics, and presented as tables, charts and graphs. Among those surveyed, prevailed: females, mean age 57.6 years, low education and income levels, most retired, unemployed or off work, with the standing position more than six hours per day and up to eight hours daily of domestic or occupational activities. In health status profile of respondents there were predominantly sleep, rest and inadequate elevation of the lower limbs, no smoking and/or alcohol use, presence of hypertension and no use of drugs. Most presented the first VU for over 10 years, recurrences, present VU for more than five years, involvement of left leg, in malleolar and / or distal leg region, mild edema, hyperpigmentation, lipodermatosclerosis, telangiectasies, reticular and varicose veins, mild pain, serous exudate in moderate quantity, small lesions (up to 50cm2), with predominance of granulation tissue and / or epithelialization and demarcated, elevated and irregular borders, with crusts and macerated. Most patients reported that in the 10 weeks prior to admission, made bandages at home and / or Basic Health Unit and / or ambulatory, with nursing aides or technicians, daily, and on weekends or holidays, performed by patients themselves, using healing ointment on the lesion, being observed granulation / epithelialization and increase in VU prevalent in the 10 weeks of traditional treatment. After follow up with manipulated Unna boot, was observed a decrease of lesions in all study patients, with complete healing in 27.8% of those between 1 and 5 weeks of treatment, with satisfactory evolution of the lesions, pain and ankle and calf circumferences, and unsatisfactory development of the borders of ulcers, edema, sleep, rest and elevation of the lower limbs, especially in more chronic patients. Furthermore, patients who achieved total healing and exhibited the greatest percentage reduction of lesions had a higher number of wound healing factors (ρ = 0.01 and ρ = 0.027, respectively). The manipulated Unna boot showed better results in those patients with shorter duration of injury, leading them to a satisfactory outcome within a short period of treatment. After the cost-effectiveness analysis, we conclude that the manipulated Unna boot is more effective than conventional therapy in the healing process of VU and is more cost-effective in patients with shorter lesions (ρ = 0.001), shorter treatment (ρ = 0.000) and greater number of wound healing factors (ρ = 0.005).

Receitas bruta e líquida parcial e custo de dietas contendo polpa cítrica para suínos abatidos com 130kg de peso

Avaliou-se o custo de inclusão da polpa cítrica em programa de restrição alimentar qualitativa, utilizando dados de desempenho de 36 suínos da linhagem Topigs, dos 83,7±5,1kg aos 129,8±1,9kg de peso, alimentados com dietas contendo porcentagens crescentes (0, 10, 20 e 30%) de polpa cítrica. Os animais foram abatidos aos 130kg e dos valores (R$) da carcaça foram descontados o valor de compra dos animais e o custo com alimentação, de acordo com cada tratamento. Não houve efeito (P>0,05) da inclusão da polpa cítrica sobre o custo com ração e receita bruta, porém houve efeito linear negativo (P<0,05) sobre o rendimento líquido parcial com o aumento da participação da polpa cítrica nas dietas. A queda no rendimento líquido parcial foi causada pelo menor peso da carcaça obtida de animais alimentados com porcentagem mais elevada de polpa cítrica. Considerando a evolução dos preços do milho, do farelo de soja e do suíno entre junho de 2005 e maio de 2006, foram determinados 12 diferentes cenários para o rendimento líquido parcial. em todos esses cenários, foi observada redução linear da receita líquida parcial em função da inclusão da polpa cítrica, mostrando que esse ingrediente não foi eficiente em promover melhora no rendimento (R$) ao produtor.

Contribuições da pesquisa operacional para gestão da produção e operações : uma análise exploratória da literatura

This research aims to investigate the evolution presented during three decades (1980, 1990 and 2000) of using the tools of Operations Research (OR) as a suport to decision making in Production Operation Management (POM). Hypothesis tests were made to verify the proportional growth of a given area over the decades to the detriment of the areas of facility layout, capacity planning, production scheduling and inventory management. Six journals were selected and from them more than 800 articles were used for classification and analysis in the grounds of review. It also discussed possible ways for future research and comparisons are made with other papers of literature review. As a result, it was found that areas of heuristics and simulation showed a greater quantity of contributions in all POM areas of this study

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developing the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. It s important to point out that, in spite of the loads being normally connected to the transformer s secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Plataforma Robótica de Baixíssimo Custo para Robótica Educacional

Robots are present each time more on several areas of our society, however they are still considered expensive equipments that are restricted to few people. This work con- sists on the development of control techniques and architectures that make possible the construction and programming of low cost robots with low programming and building complexity. One key aspect of the proposed architecture is the use of audio interfaces to control actuators and read sensors, thus allowing the usage of any device that can produce sounds as a control unit of a robot. The work also includes the development of web ba- sed programming environments that allow the usage of computers or mobile phones as control units of the robot, which can be remotely programmed and controlled. The work also includes possible applications of such low cost robotic platform, including mainly its educational usage, which was experimentally validated by teachers and students of seve- ral graduation courses. We also present an analysis of data obtained from interviews done with the students before and after the use of our platform, which confirms its acceptance as a teaching support tool