Eficiência técnica dos produtores familiares no Projeto de Irrigação do Baixo Açu/RN

SILVA, Jorge Luiz Mariano da. Eficiência técnica dos produtores familiares no projeto de irrigação do Baixo Açu/RN.In: CONGRESSO SA SOCIEDADE BRASILEIRA DE ECONOMIA E SOCIOLOGIA RURAL,42., 2004, Cuiabá - MT. Dinâmcias Setorias e Desevolvimento Regional, 2004.

Avaliação da adição de Nanosílica e silicato de sódio em pastas de cimento para poços de petróleo com baixo gradiente de fratura

The oil wells cementing is a critical step during the phase of well drilling, because problems during the operation of slurry pumping and an incomplete filling of the annular space between the metal casing and the formation can cause the slurry loss. Therefore, the slurry adopted in primary cementing an oil well must be properly dosed so that these problems are avoided during its pumping. When you drill a well in a weak rock formation requires even more careful, because should be a limit of hydrostatic pressure exerted during cementation, that does not occur rock collapse. With the objective of performing the cementing of a well whose formation is weak or unconsolidated are employed lighter slurries. Thus, this study used slurries with sodium silicate and nano silica in concentrations of 0,1; 0,4; 0,7 e 1,0 gpc, in which the slurries with nano silica showed the rheological parameters higher concentrations of up to 0.7 gpc and for concentration of 1.0 the slurry with sodium silicate obtained the highest values, remaining above the limits for application in fields, mainly wells with low fracture gradient, because a significant increase in viscosity may result in an increase in pressure pumping in operations of secondary cementations. Furthermore, there was no decrease in strength with increasing concentration of additive. Then, it is possible use of these additives to formulate Lighter slurry

Diagnóstico da possível influência da atividade petrolífera em sedimentos de fundo da Bacia Piranhas-Açu, região Baixo Açu/RN

It is located in an area of increasing oil exploration, the region of the Lower Açu is at the mercy of a possible pollution generated by this economic activity, which includes various chemical substances harmful to health, such as metals. This thesis aims to, diagnose the areas of River Piranhas-Açu, a region of the Lower Açu, which are polluted by traces factors and more. In this study, it was determined the concentration of the chemica elements Al, CD, Cr, Cu, Fe, Mn, Ni, P, Pb, V and Zn, through the technique of ICP-OES analysis and the size of sediments and their contents organic matter. Were mapped by GPS, 12 points from collections. The interpretations of the results, together associating that allowed pollution to a possible contamination by oil activity. The results showed tha some regions have low concentrations of cadmium, lead, copper, manganese and zinc unable to promote damage to human health. However, there are places where the concentrations of certain metals chromium, iron and zinc are moderately polluted compared to the results with the reference values of literature and others that are highly polluted by iron. However, due to a greater number of wells in production in those locations, those higher concentrations, it can be suggested a possible influence of oi production in some areas with concentrations of chromium and lead are higher than the rest of the points of monitoring. Moreover, it is observed that the highest levels of metals found in sediment of finer texture and more organic matter content

Desmame em recém-nascidos de muito baixo peso ao nascer no primeiro retorno ambulatorial após a alta hospitalar

Investigate intrahospital and neonatal determinants associated to the weaning of very low birth weight (VLBW) infants. Methods: 119 VLBW (<1500g) infants 81 were monitored from July 2005 through August 2006, from birth to the first ambulatory visit after maternity discharge. This maternity unit uses the Kangaroo Method and the Baby Friendly Hospital Initiative. Results: Out of 119 VLBW infants monitored until discharge, 88 (75%) returned to the facility, 22 (25%) were on exclusive breastfeeding (EB) and 66 (75%) were weaned (partial breastfeeding or formula feeding). Univariate analysis found an association between weaning and lower birth weight, longer stays in the NICU and longer hospitalization times, in addition to more prolonged enteral feeding and birth weight recovery period. Logistic regression showed length of NICU stay as being the main determinant of weaning. Conclusion: The negative repercussion on EB of an extended stay in the NICU is a significant challenge for health professionals to provide more adequate nutrition to VLBW infants

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

Acelerando algoritmos de baixo nível em visão robótica com hardware reconfigurável

A challenge that remains in the robotics field is how to make a robot to react in real time to visual stimulus. Traditional computer vision algorithms used to overcome this problem are still very expensive taking too long when using common computer processors. Very simple algorithms like image filtering or even mathematical morphology operations may take too long. Researchers have implemented image processing algorithms in high parallelism hardware devices in order to cut down the time spent in the algorithms processing, with good results. By using hardware implemented image processing techniques and a platform oriented system that uses the Nios II Processor we propose an approach that uses the hardware processing and event based programming to simplify the vision based systems while at the same time accelerating some parts of the used algorithms

Viabilidades térmica, econômica e de materiais de um sistema solar de aquecimento de água a baixo custo para fins residenciais

An solar alternative system for water heating is presented. Is composed for one low cost alternative collector and alternative thermal reservoir for hot water storing. The collector of the system has box confectioned in composite material and use absorption coils formed for PVC tubes. The box of hot water storage was confectioned from a plastic polyethylene drum used for storage of water and garbage, coated for a cylinder confectioned in fiber glass. The principle of functioning of the system is the same of the conventionally. Its regimen of work is the thermosiphon for a volume of 250 liters water. The main characteristic of the system in considered study is its low cost, allowing a bigger socialization of the use of solar energy. It will be demonstrated the viabilities thermal, economic and of materials of the system of considered heating, and its competitiveness in relation to the available collectors commercially. Relative aspects will be boarded also the susceptibility the thermal degradation and for UV for the PVC tubes. It will be shown that such system of alternative heating, that has as main characteristic its low cost, presents viabilities thermal, economic and of materials

Análise quali-quantitativa do deslocamento da camada-limite em carrocerias veiculares

Dois dos principais objetivos no estudo da aerodinâmica de veículos é a segurança e o desempenho. Esses objetivos podem ser alcançados através do desenvolvimento de dispositivos que modifiquem o escoamento de ar ao redor do veículo e também através de alterações da forma das superfícies externas. O perfil mais baixo da frente do veículo, por exemplo, tem grande influência sobre o coeficiente de penetração aerodinâmica (Cx) e posteriormente sobre grande parte da distribuição de pressão ao longo da superfície do veículo. O objetivo deste trabalho foi de analisar o comportamento aerodinâmico que incide sobre 2 (dois) tipos de carrocerias de veículos, baseado em experimentação em túnel aerodinâmico, visando determinar a eficiência aerodinâmica de cada uma delas. Foram comparados dois modelos de veículos, sendo um deles com configuração familiar, muito comum nas grandes cidades e outro modelo com configuração esportiva mais voltado para o desempenho, ambos com escala 1:18. Para a realização do experimento foi construído um túnel aerodinâmico do tipo soprador com circuito aberto, onde foram analisadas as distribuições de pressão nas superfícies inferiores e superiores da carroceria dos modelos e o deslocamento da camada-limite. Tomando-se por base toda a teórica deste trabalho, com relação à aerodinâmica de carroceria, considerou-se nesta dissertação que essa filosofia de pesquisa é capaz de gerar reflexos positivos, que podem tornar os veículos cada vez mais eficientes e influenciar positivamente nos níveis de segurança e desempenho

Estudo da Potencialidade da produção de tijolos de adobe misturado com outros materiais: uma alternativa de baixo custo para a construção civil

The production of the red pottery brick, made traditionally with clay, is a technique that is already stabled. However, in spite of the little complexity that involves the conventional process of these bricks production, it are exposed to many problems that begin in the fase of exploration of the mines, the problems get worse because of the lack of the clay's characterization, and they continue through the steps of the dough preparation, conformation of the products, the drying and the burning process. The wastefulness is shown and so is the low quality of the material produced. Among other factors, the high use of energy in the burning makes the cost of this material inaccessible to the low income consumer. Besides this, the destruction of the environment around the mines and the use of native vegetation to produce wood - the most used fuel in the pottery industry - make serious environmental damage. The production technique of a new type of simple brick (adobe), that has low cost and no environmental damage, can be the viable altemative to lower the cost of this part of the civil construction, and, consequently, in the building of cheaper houses. In this paper, the results of the mechanical resistance of the adobe brick are shown, using in its composition, clay, natural vegetable fibers, cement and plaster in a process that is completely handcrafted and manual. It is intented to make clear that are possible alternatives to be put in practice, with the simple process, using "raw earth" that has been used in the construction of houses in thousands of years, trying to solve these severe problems. Analysis and tests were performed to find results that could prove the possibility of the utilization of this kind of material. Other studies are in progress, and the new researches are necessary to enrich this work, but it stays the certainty that there is potential to produce bricks from adobe, as an alternative that has low cost to civil construction

Construção, calibração e análise de desempenho de um piranômetro de baixo custo, baseado no modelo Kimball-Hobbs

In this work a pyrometer using the classic model of Kimball-Hobbs was developed, tested and calibrated. The solar radiation is verified through the temperature difference between the sensible elements covered by absorbing (black) and reflecting (white) pigmentations of the incoming radiation. The photoacoustic technique was used to optimize the choice of the pigments. Methodologies associated with linearity, thermo-variation, sensibility, response time and distance are also presented. To correctly classify the results, the international standard ISO 9060 as well as indicative parameters of World Meteorological Organization (WMO) are used. In addition a system of data acquisition of two channels with 12 bits, constructed during the this time, was used to measure the global solar radiation on the ground by the pyrometer and also by another pyrometer certified in the case of Keep & zonen. The results statistically show, through the hypothesis test presented here, that both equipments find population average with 95% of correctness

Projeto, construção e análise de desempenho de um forno solar alternativo tipo caixa a baixo custo

An alternative box-type solar oven constructed from the scrap iron of a gas conventional cook is presented, which functions principles are the effect greenhouse and the concentration. The oven of the conventional cook is the baking enclosure where the absorber (pot) of the solar oven is located, being re-covered for a glass blade for the generation of the greenhouse effect isolated lateral and having deep its and for a composite the plaster base and EPS. Segments of plain mirrors had been placed in the laterals of the oven for the concentration of the radiation and a reflecting parabola was introduced in the baking enclosure for the exploitation of the incident reflected radiation in the interior of the oven. The oven is mobile to allow one better aiming of exactly in relation to the apparent movement of the sun. The thermal economic and of materials viabilities of the stove in study will be demonstrate The average internal temperature of the absorber was around 150°C and the internal temperature around 120°C. Will demonstrate that its low cost and good thermal performance represents basic characteristics for the viability of large use of such archetype, mainly for cooking the decreases and averages temperatures. One will reveal that the archetype in study is competitive with the box-type solar cooker conceived in the whole world

Análise do desempenho térmico de um sistema de aquecimento solar de baixo custo

It presents a solar collector to be used in a system for heating water for bathing, whose main characteristics are low cost and easy manufacturing and assembly. The system operates under natural convection or thermosiphon. The absorbing surface of the collector is formed by twelve PVC pipes of 25 mm outside diameter connected in parallel via connections in T of the same material. The tubes were covered with absorbing fins made with recycled aluminum cans. We studied eight settings between absorber plate, thermal insulating EPS boards and thermal reservoirs 150 and 200 liters. It was determined the most efficient configuration for the correct purpose. We evaluated thermal parameters that proved the viability of the heating system studied

Projeto, construção e análise de eficiência térmica de um sistema de aquecimento solar de água de baixo custo

We studied the feasibility of using a system of Solar Water Heating (SAS) with low cost, for three configurations. In configurations I and II have the collector grid absorber composed of six PVC tubes placed in parallel on the tile cement. In configuration II, the PVC tubes were transparent cover made of plastic bottles. Configuration III uses a collector composed of 12 black HDPE pipes, supported on four cement tiles 2.44 m x 0.50 m, two by two overlapping and interspersed with a filling of glass wool, comprising an area exposed to the global radiation incident of 2.44 m2, with the top two tiles painted matte black. In this configuration, the HDPE pipes replace conventional PVC pipes painted black. The total cost of SAS for configuration III, the most economical, was around $ 150.00. For the configurations tested the system of operation was thermosyphon collector. The study showed that the proposed systems have good thermal efficiency, are easy to install and handle and have low cost compared to conventional.

Obtenção e caracterização de farinha de frutas e vegetais através do uso de um sistema de secagem solar de baixo custo

In this work a solar drying system for food dehydration was developed. It is a direct exposition drying apparatus that uses solar energy to heat the circulating air. First, the construction and assembly of this apparatus was described, in which was used scrap wraps of used tires for thermal insulation, allowing the reuse of solid waste, being an ecologically correct recycling option. After, the results obtained in experiments for cashew drying showed the thermal and economical feasibility of the proposed solar drying system, focusing on the process of flour production and in its chemical characterization. It was also demonstrated the social importance of this production for socially excluded people, since the value added to this fruit, in relation to its in nature form, may represent an option for job and income generation. The main features of the proposed dryer are its low cost and its easy fabrication and assembly process. After cashew drying, the obtained product was processed into flour by using a knife mill and it was added crushed rapadura to reduce the rancid taste caused by tannin

Desenvolvimento de sistemas de pastas leves para aplicação em cimentação de poços petrolíferos com baixo gradiente de fratura

All around the world, naturally occurring hydrocarbon deposits, consisting of oil and gas contained within rocks called reservoir rocks , generally sandstone or carbonate exists. These deposits are in varying conditions of pressure and depth from a few hundred to several thousand meters. In general, shallow reservoirs have greater tendency to fracture, since they have low fracture gradient, ie fractures are formed even with relatively low hydrostatic columns of fluid. These low fracture gradient areas are particularly common in onshore areas, like the Rio Grande do Norte basin. During a well drilling, one of the most favorable phases for the occurrence of fractures is during cementing, since the cement slurry used can have greater densities than the maximum allowed by the rock structure. Furthermore, in areas which are already naturally fractured, the use of regular cement slurries causes fluid loss into the formation, which may give rise to failures cementations and formation damages. Commercially, there are alternatives to the development of lightweight cement slurries, but these fail either because of their enormous cost, or because the cement properties were not good enough for most general applications, being restricted to each transaction for which the cement paste was made, or both reasons. In this work a statistical design was made to determine the influence of three variables, defined as the calcium chloride concentration, vermiculite concentration and nanosilica concentration in the various properties of the cement. The use of vermiculite, a low density ore present in large amounts in northeastern Brazil, as extensor for cementing slurries, enabled the production of stable cements, with high water/cement ratio, excellent rheological properties and low densities, which were set at 12.5 lb / gal, despite the fact that lower densities could be achieved. It is also seen that the calcium chloride is very useful as gelling and thickening agent, and their use in combination with nanosilica has a great effect on gel strength of the cement. Hydrothermal Stability studies showed that the pastes were stable in these conditions, and mechanical resistance tests showed values of the order of up to 10 MPa