999 resultados para Cinza de caldeira


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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With the increase in cement consumption, it has quickly become one of the inputs most consumed by mankind over the last century. This has caused an increase in CO2 emissions, as cement production releases large quantities of this gas into the atmosphere. Adding this fact to the growing consciousness of environmental preservation, it has led to a search for alternatives to cement to complement its derivatives, in the form of waste materials like the ashes. This research aimed to analyze the properties of mortars in fresh and hardened state with partial replacement of Portland cement by residual algaroba wood ash (CRLA) potteries produced by the state of Rio Grande do Norte. The CRLA was collected and sieved, where part of it was ground and characterized in comparison with that just sifted, being characterized according to its chemical composition, grain size, fineness, density, bulk density and index of pozzolanic activity. It was found that the wood ash does not act as pozzolan, and grinding it has not changed its characteristics compared to those just sifted, not justifying its use. Two traces were adopted for this research: 1:3 (cement: fine sand) and 1:2:8 (cement: hydrated lime: medium sand); both in volume, using as materials the CRLA just sifted, CP II F-32 Portland cement, CH-I hydrated lime, river sand and water from the local utility. For each trace were adopted six percentages of partial replacement of cement for wood ash: 0% (control) 5%, 7%, 10%, 12% and 15%. In the fresh state, the mortars were tested towards their consistency index and mass density. In the hardened state, they were tested towards their tensile strength in bending, compressive strength and tensile adhesion strength, and its mass density in the hardened state. The mortar was also analyzed by scanning electron microscopy and X-ray diffraction. Furthermore, it was classified according to NBR 13281 (2005). The results showed that up to a content of 5% substitution and for both traces, the residual algaroba wood ash can replace Portland cement without compromising the mortars microstructure and its fresh and hardened state

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Concrete is the second most consumed product in the world and the incorporation of the Sugar Bagasse Ash (SBA) into this material can provide solutions for the utilization of by-products from other industries, thus reducing the environmental impact. The general aim of this dissertation focuses on analyzing the mechanical behavior of concrete with addition of SBA from three different species of sugar cane, through tests of consistency, compressive strength, porosity, absorption, voids and Scanning Electron Microscopy (SEM). Were prepared 13 specimens for each specific pattern and level of incorporation of SBA (10%, 20% and 30%) of the three varieties collected, totaling 130 samples of concrete. The trait was employed 1:2:3 (cement: sand: aggregates) in relation to the cement mass with a water / cement ratio of 0.532 and 1% additive Tec 400 Mult also based on the weight of cement. According to the results obtained in this study, it was concluded that the variety of cane sugar, used in the production of the CBC, influenced the mechanical behavior of the resulting concrete. All concrete with addition of SBA, reported a reduction of at least 10% in the properties related to permeability and an increase in the compressive strength of at least 16% compared to standard concrete at 28 days

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The use of sewage sludge as a raw material falls within the waste recycling key in the current process model environmental sustainability .Waste recycling has been consolidated as a sustainable environmentally sound technical solution, and. Despite showing very variable composition and characteristics, sewage sludge, can be considered as a residue with a high recycling potential in the building sector. In this paper the feasibility of using sewage sludge ash was studied in addition to Portland cement mortar in 1:3 mass considered the standard dash. This gray additions were studied in proportions of 5%, 10 %, 15 %, 20 %, 25% and 30% by mass of cement. The methodology was focused on the characterization of materials by physical, chemical , mechanical , environmental and morphological followed by the production of mortar tests ,and finalized by the characterization tests of mortar in the fresh state, through the consistency index, content of entrained air, bulk density and water retention, and in the hardened state by bulk density, water absorption by capillarity capillarity coefficient, compressive strength, tensile strength in bending ,tensile bond strength and microstructural analysis for percentages of 0 to 20%. After comparing with the standard mortar mortars with addition of ash, it is concluded that the ash of sewage sludge did not impair the integrity and properties of mortars with addition, including increasing resistance to compression and tension, being 20% more indicated percentage. Thus, it becomes feasible the addition of sewage sludge ash in Portland cement mortar for the trait studied

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Every day, water scarcity becomes a more serious problem and, directly affects global society. Studies are directed in order to raise awareness of the rational use of this natural asset that is essential to our survival. Only 0.007% of the water available in the world have easy access and can be consumed by humans, it can be found in rivers, lakes, etc... To better take advantage of the water used in homes and small businesses, reuse projects are often implemented, resulting in savings for customers of water utilities. The reuse projects involve several areas of engineering, like Environmental, Chemical, Electrical and Computer Engineering. The last two are responsible for the control of the process, which aims to make gray water (soapy water), and clear blue water (rain water), ideal for consumption, or for use in watering gardens, flushing, among others applications. Water has several features that should be taken into consideration when it comes to working its reuse. Some of the features are, turbidity, temperature, electrical conductivity and, pH. In this document there is a proposal to control the pH (potential Hydrogen) through a microcontroller, using the fuzzy logic as strategy of control. The controller was developed in the fuzzy toolbox of Matlab®

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The red ceramics and structural ceramics, as they are known, include ceramic materials made by blocks of seals and structures, bricks, tiles, smail flagstones manacles, rustic floors and ornamental materials. Their fabrication uses raw material such as clay and clay sites, with some content of impurity. It has good durability and mechanical strength to compression, low cost, making it one of the mainly used materials in civil engineering. The incorporation of many industrial activities residue to ceramic products is a technological alternative for reducing the environmental impact caused by its carefree disposal. This incorporation can promote chemical change and inertness of metals from residue, by fixation in the glassy phase of ceramic during the burning stage. The main aim of this project is to study the technical feasibility of the addition of ceramic oven ash into formulations of mass for structural ceramics. In this project two kinds of clay (plastic and non-plastic) were used, as well as the ash from firewood used in the process of burning of structural ceramics. A group of experiments was outlined, which permitted the evaluation of the influence of the burning cycle in different temperatures of the ash content in formulations for ceramic blocks through technological properties, mechanical behavior and microstructure. Five samples were processed of each one of the masses of plastic and non-plastic clay without addition of ash and with addition of ash on the percentages of 10 % and 20 %, for temperatures of 850 °C, 950 °C, 1050 °C and 1150 °C, obtained through sinterization process. Among the studied compositions, the one which presented best performance was the mass of clay with 10 % of ash, at temperature of 1150 °C, with the smallest absorption of water, the smallest apparent porosity, specific apparent mass a bit over the others and greatest mechanical resistance to flexion. The composition made confirmed the technical feasibility of the use of ash in the mass for structural ceramics with maintenance of its necessary characteristics for its purposes

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The production of red ceramic is an industrial activity that causes an intense impact. The manufacture of its products considerably increases the demand for natural resources, mainly with the extraction of raw material. The ceramic material produced generates waste, such as ash firewood and chamote. The residue from the beneficiation of kaolin is deposited in a poor, degrades the environment and contaminate water sources and soil, constituting in this manner, ecological disasters. The main objective of this work is to develop the formulation of a ceramic product consisting solely of industrial solid wastes, from ceramic tiles, (chamote) residue of kaolin and ash firewood. It is assumed that this product made in the laboratory can be used in coatings, wall and floor. The aim is to facilitate the replacement of the raw material of original composition of a ceramic body, for waste, while the process of production equal to the conventionally used, so that the properties of the product are reproduced. This work is characterized waste as its chemical composition, analysis of particle size, X-ray diffraction and thermal behavior. Several formulations were studied. The mass of waste was prepared by dry process, pressed to 25 MPa, and then burned in muffle type oven to 850, 950, 1050 and 1150 °C. The results showed that it is technically possible to produce porous tiles only with waste. It was found that the formulations of bodies play a key role in the properties of the final product, as well as the sintering temperature and heating rates. RN in the waste of kaolin is estimated at 15,000 t/month, about 3,000 gray t/month and chamote with 10 million pieces/month damaged. The presence of carbonates of calcium and magnesium at 1050 ° C results in an appropriate porosity and mechanical strength. The formulation M3JE, composed of 69% waste of kaolin, 7.7% and 23.3% of chamote of gray, became suitable for porous materials with the strength and absorption within the level of national and international standards

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This study aimed to investigate the use of cane sugar ashes from small-scale stills of Eunápolis region, state of Bahia, in pottery mass that can be developed as porcelain stoneware. Bahia is the second largest producer of rum distillery in Brazil. In the production of rum is produced residue called bagasse, which is used to generate electricity in Power plants and in the distillery itself, generating ashes as residue, which is played in nature, causing environmental damage. We studied 5 (five) formulations of 0% 10% 20%, 30% and 40% by weight of the ash, without ignition and 3 (three) formulations of 10%, 20% and 30% with gray ash temperature of 1250ºC. The formulation at 0% by weight of ash was used for a comparison between the traditional mass of porcelain stoneware and the masses with the addition of ash calcined, replacing feldspar. The percentage by weight of kaolin and of Clay was kept the same, 30%, and all raw materials were derived from the state of Bahia. The samples were made in uniaxial array with dimensions of (60 x 20 x 5) mm and compressed to a pressure of 45 MPa. Assays were performed to characterize the raw by X-ray fluorescence, X-ray diffraction, ATD and ATG and Dilatometric analysis. The samples were sintered at temperatures of 1100°C, 1150°C, 1200°C and 1250°C, for the specimens with the ashes without ash and 1150° C and 1200° C for specimens with the gray level of calcined 60 minutes. and then we made a cooling ramp with the same rate of warming until reach ambient temperature. The sintered bodies were characterized by water absorption, porosity, linear shrinkage, bending strength and XRD of the fracture surface and the results analyzed. It was proven, after results of tests performed, that it is possible to use the ash residue of sugar cane bagasse on ceramic coating with the addition of up to 10% wt of the residue ash

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The adhesive mortars are a mixture of cement, sand, and additives to polymers that retain the mixing water and promotes adherence, being used in setting on various ceramic substrates. The sand used in the production of these mortars is from the riverbeds, and with the increasing restriction of these sands extraction by environmental agencies, and often having to be transported over long distances to the consumer center. This work aims to design and physical and mechanical characterization of ecological adhesive mortar with total replacement of natural sand by sand from the crushing of limestone, and the addition of mineral ash biomass of cane sugar in partial replacement cement used in the production of adhesive mortar , aiming compositions that meet the regulatory specifications for use adhesive mortar. Standardized tests to determine the tensile bond strength (NBR 14081-4), determination of open time (NBR 14081-3) and determination of slip (NBR 14081-5) were performed. Were also conducted trials squeeze flow in different formulation, the mortar with addition of 15 % gray biomass of cane sugar for cement mortars as well as the total replacement of natural sand by sand limestone crushing, got the best performance among the mortars studied, it was found that the addition of biomass to replace cement is perfectly feasible due to its pozzolanic activity, which contributed to this reduction in the cement matrix formation of adhesive mortar

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O presente trabalho teve como objetivo avaliar as características de crescimento, produção e caracterizar alguns atributos de qualidade dos frutos do cultivar de bananeira-Figo-Cinza em dois ciclos de produção, nos anos de 2009 e 2010. Foram avaliadas características de crescimento, tais como altura da planta, circunferência do pseudocaule, número de folhas ativas, número de perfilhos e número de dias entre o florescimento e a colheita. Estas medidas foram feitas na emissão da inflorescência. Foram mensuradas também as características de produção, como peso do cacho, número de frutos, número de pencas, número, comprimento e diâmetro dos frutos da 2ª penca. em relação à qualidade dos frutos, foram analisados os atributos físicos e químicos: textura; pH; acidez titulável e sólidos solúveis. O delineamento adotado foi o inteiramente casualisado, com dois tratamentos (ciclos), cinco repetições e duas plantas úteis por parcela experimental. Foi utilizado o teste de Tukey (P< 0,05) para a comparação entre as médias. em geral, as características de crescimento e produção foram maiores no segundo ciclo, apresentando 134 dias do florescimento à colheita, circunferência do pseudocaule de 64,20 cm, altura de planta igual a 3,82 m e peso de cacho de 11,83 kg. Os atributos de qualidade não variaram entre os ciclos, exceto a textura, que foi maior no segundo ciclo, com valores médios de 993,31 gfcm-2.

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This study investigated factors that influence the group size during the behavior foraging of estuarine dolphin Sotalia guianensis in the coast south of the state Rio Grande do Norte (RN), it also characterized the diet of estuarine dolphins and elaborated an otoliths catalog for aid in the identification of the preys found in the stomach contents. In relation to the group size during behaviour foraging, inside of the Curral Bay, larger frequency of solitary hunt was observed. Factors as tide variation, group composition and seasons didn't present correlation with the number of animals observed during a feeding episode. Capture success for participant was shown significantly larger when the animals hunted alone, what possibly explains the largest frequency of solitary hunt inside of the Curral Bay. About diet, were identified 18 bone fishes species, with predominance of species the families Haemulidae and Sciaenidae and five cephalopods species, including two new species in the diet of Sotalia guianensis in Brazil. Our results indicated that estuarine dolphin in the coast oriental from Rio Grande do Norte (RN) feeds predominantly of fish that form shoal, of habitat estuarino and producing of sounds. The analysis of the images, otoliths of 43 species of coastal fish of the coast of the state of Rio Grande do Norte (RN), aided by the offered descriptions, demonstrated to be an effective methodology for the knowledge of those structures, as well as it represented a form of reducing the subjectivity in the identification of the bone fishes found in stomach content

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Sotalia guianensis is a small cetacean of the Delphinidae family, with coastal habits and whose area of distribution ranges from Florianópolis (27º35'S, 48º34'W), in Brazil, to Honduras (15º58'N, 85º42'W). At Pipa beach, on the south coast of RN state, in Brazil, the species occur throughout the year. The present study was carried out in two bays, which are bordered by cliffs. The animals were monitored from vantage points, using the "Ad libitum" and "all the occurrences" methods; during the years of 1999 and 2004. The study was divided in 4 chapters: Behavioral standards of two populations of gray dolphin, (Sotalia guianensis, Van Benédén, 1864) in the northeast of Brazil; Aerial activity of the gray dolphin: its possible function and the influence of environmental and behavioral factors; The influence of daily and monthly variation of the tides, of the period of the day and group size on the gray dolphin forage activity; kleptoparasitism interactions of frigatebird (Fregata magnificens, Mattheus, 1914) during the gray dolphin forage activity. The results have shown that the gray dolphin has a varied and complex behavioral repertoire. The leap is the most frequent behavior; the aerial activity is diffuse during daylight and is influenced by some factors, such as the level of the tide and social factors. The gray dolphin, when in the bay, most frequently feeds isolate or in small groups. The forage is diffuse during daylight; however, being more frequent in the morning and is influenced by the daily and monthly variation of the tide. At Pipa beach, kleptoparasitarian interactions were registered between the gray dolphin and the frigatebird (Fregata magnificens). The frigatebird forage strategy consists basically of two ways: to fly over great extensions searching for dead fish and to steal food (kleptoparasitism). These interactions were predominantly carried out between immature and female adult birds and adult and immature dolphins, and occurred during daylight. The present study can be considered an initial landmark to a better knowledge on the gray dolphin surface behavior, especially regarding the aerial behavioral repertoire and forage strategy of this species. However, it is necessary to continue these studies, so that we can understand better the complex social life of these animals and thus create effective measures for its conservation

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Four areas are known as of frequent usage by Guiana dolphins (Sotalia guianensis) in the south coast of Rio Grande do Norte state, northeast Brazil: Tabatinga, Pipa, Lagoa de Guaraíras and Baia Formosa. This extension of 40 km of shoreline is under increasing anthropogenic impacts due to continuous development of the coastal areas and vessel traffic. The objective of this study was to investigate aspects of population biology and habitat use of the population of Sotalia guianensis in the south coast of Rio Grande do Norte. It was applied the photo-identification technique and posterior methods of capture-recapture for population estimation (POPAN extension in MARK). The distribution, movement and site fidelity of the dolphins were analyzed trough the geographic information system (GIS) and group characteristics and behavior trough non-parametric statistics. Field work was conducted on board a 10m motor vessel from March 2008 to March 2009. Photo-identification effort was 329h with 113h of direct observation of the dolphins. The population estimatives for each area: Tabatinga: 75 (63-92); Pipa 105 (88-129); Lagoa de Guaraíras: 27 (18-54) e Baia Formosa: 112 (89-129) individuals. Total population estimative was: 223 (192 a 297). High site fidelity was detected for only part of the population (<15%) as low site fidelity and transients individuals were also detected (>20%). It was observed frequent movements between Tabatinga, Lagoa de Guaraíras and Pipa, but not Baía Formosa. This suggests a division in two communities along this shore extension: one in Pipa and other in Baía Formosa. Group size was small, most groups with up to 10 dolphins. The areas were use intensively, only in Lagoa de Guaraíras dolphins were not seen in all field trips. Lagoa de Guaraíras is an area used by small groups exclusively for foraging. In Tabatinga and Pipa dolphins concentrated close to the shore, in the inner sector of the area and the main activity is also foraging. Significant larger groups were seen in socializing behavior but there was no difference in group size between the inner and external sectors of the area. The presence of calves and juveniles were significant greater in the inner areas of Tabatinga and Pipa, confirming the hypothesis that these beaches are also used for parental care. In Baia Formosa dolphins concentrated in the outer sector and foraging was also predominant. Significant larger groups were seen in the outer sector, mainly engaged in mixed behaviors of travel/foraging, possibly in some kind of group foraging. Calves and juveniles were significant more present in the outer sector where group size was also larger. In general there was no difference in area usage and period of the day. Sotalia guianensis has characteristics that make the species vulnerable to human activities such as small population concentrated in patches of suitable habitats restrict to coastal areas. We hope that this study bring new information for the species and help for the adequate management of the area in order to assure the presence of the dolphins as well as its behavior pattern and gene flow betweencommunities.