997 resultados para Cal. Resíduo do polimento do porcelanato. Argamassa de revestimento. Restauração
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The industrial production of ornamental rocks and the burning of coffee husk generate waste that is discarded into the environment. However, with the study of the incorporation of these residues in ceramic products, may be found an alternative to reducing environmental impacts and detrimental effects on human health caused by its indiscriminate disposal of waste in nature. Thus, this work aimed to study the addition of ashes of the coffee husk and granite residue in matrix of red ceramic. The raw materials were dry milled and sieved to mesh 100. To characterize the raw materials were carried out analyzes of X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size analysis (PSA), differential thermal analysis (DTA) and thermogravimetric analysis (TG). Six formulations were prepared where the clay content was kept constant (70%wt) and ashes contents and granite residue varied from 10, 15, 20 and 30%. Dilatometrics analyzes were performed at four selected formulations, containing them: 100% clay (A100); 70% clay and 30% ashes (A70C30); 70% clay and 30% granite residue (A70G30); and 70% clay, 15% granite residue and 15% ashes (A70G15C15). The samples were prepared by uniaxial compaction with pressure of 25 MPa, and fired at temperatures of 800°C, 850ºC, 900ºC, 950ºC, 1000ºC and 1100°C. Assays were performed to determine the linear shrinkage of burning (LSB), water absorption (WA), apparent porosity (AP), density (D) and tensile bending. Also were performed analyzes of X-ray diffraction (XRD) and scanning electron microscopy (SEM) of the samples fired. The formulations incorporating granite residue and/or ashes reached the required limits of water absorption according to NBR 15270-1 and NBR 15310 and tensile bending according to classical literature (SANTOS, 1989) necessary for the production of tiles and ceramic block for masonry sealing
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Universidade Federal do Rio Grande do Norte
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Researches have shown that the introduction of rubber in concrete improves the features of its deformability, as well as contributes to environmental disposal of waste generated in the tire retreading process. Furthermore, there is a high availability of limestone within RN and CE country. Ignorance about this stone, does not allow its wide use as aggregate, leaving, this abundant supply idle. A composite of limestone gravel, with proportions of tire rubber waste which could be used as concrete would be an alternative to concrete for low applications. Therefore, this research aims to evaluate the characteristics of concrete containing limestone gravel and proportions of little aggregate replacement (sand) by tire rubber waste. To this goal, the material components of the concrete were characterized, concrete specimens with limestone gravel were made, from the dash 1.0: 2.5: 3.5, varying the water/cement ratio, and inserting a commercial plasticizer, without a proportion of residue, known as reference. From this, concrete with and without the presence of the additive in the same proportions were chosen, as well as these with the use of granite gravel, for being the most used. Selected the references, to these, replacements of little aggregate (sand) were added replaced by rubber waste from the tire retreading process, treated with 1M NaOH in proportions from 5.0 to 20.0 % by mass, cured and exposed to the semiarid environment. The results indicate the possibility of using limestone gravel in the concrete composition with workability correction using plasticizer. There was a decrease in the mechanical properties of the concrete with increments of waste rubber, but there is an improvement in toughness and deformability of the composite, which makes it interesting for the construction of non-structural concrete floors, as well as, the rubber waste delayed the hardening process, continuing to gain resistance after 28 days
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2009
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Regulamentação de padrões de qualidade de CRSU x mercado. Regulamentações em outros países. Regulamentação federal brasileira.
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O porquê do uso agronõmico do composto de lixo. Critérios de aplicação e de manejo do composto. Efeitos sobre as propriedades do solo. Capacidade de troca catiônica (CTC). rEAÇÃO DO SOLO. Nutrientes. Relação C/N. Nitrogênio. Fósforo. Potássio, cálcio, magnésio e sódio. Enxofre e micronutrientes. Salinidade e sociedade. Elementos inorgânicos potencialmente tóxicos. Efeitos sobre as plantas.
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O objetivo desse trabalho foi avaliar o perfil fermentativo das silagens do resíduo agroindustrial da extração do palmito da pupunha in natura, aditivada com fubá de milho (10% do peso verde) e emurchecida. Utilizou-se silos de laboratório (de PVC, 10 cm de diâmetros x 40 cm de comprimento). As aberturas dos silos ocorreram aos 1, 3, 5, 7, 14, 28 e 56 dias após a ensilagem. Os valores de pH não apresentaram diferença significativa (P>0,05) entre os tratamentos tendo como média (3,80) no dia 56, no entanto esses valores apresentaram padrão de mudança cúbico ao longo dos dias com o valor mínimo sendo atingido no dia 14 para todos os tratamentos. A adição do fubá de milho na silagem elevou os teores de MS (19,71%) e PB (7,09%), no entanto não reduziu o valor de N-NH3/NT (7,89%) apresentando diferença significativa (P<0,05) com o tratamento com emurchecimento que obteve o menor valor de N-NH3/NT (6,35%). A silagem do resíduo da extração do palmito da pupunha aditiva com o fubá de milho melhorou o valor de MS e o valor de PB, podendo ser uma alternativa para alimentação dos ruminantes.
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A extração de palmito da pupunha, na região Sul do estado da Bahia, vem gerando grande quantidade de derivados, que podem ser uma alternatia de alimentação para os ruminantes na forma de silagem. Podendo, assim, solucionar o destino desses co-produtos e, desta forma, gerar tecnologias voltadas para o uso sustentável dos recursos naturais associados ao ecossistema regional. O objetivo do trabalho foi avaliar o perfil fermentativo das silagens do co-produto agroindustrial da extração do palmito da pupunha in natura, aditivada com torta de dendê (10% do peso verde) e emurchecida. Utilizou-se silos PVC com 10 cm de diâmetros x 40 cm de comprimento. As aberturas dos silos ocorreram aos 1, 3, 5, 7, 14, 28 e 56 dias após a ensilagem. Os valores de pH não apresentaram diferença significativa (P>0,05) entre os tratamentos tendo como média (3,82) no dia 56, no entanto esses valores apresentaram padrão de mudança cúbica ao longo dos dias com o valor mínimo sendo atingido no dia 14 para todos os tratamentos. A adição da torta de dendê na silagem elevou os teores de MS (21,06%) e PB (7,79%), reduziu os valores de N-NH3/NT (3,73%) e de perda de MS (0,82) apresentando diferença significativa (P<0,05) para os demais tratamentos. A silagem do co-produto da extração do palmito da pupunha aditivada com torta de dendê melhorou os parâmetros de fermentação e o valor de PB. podendo ser uma alternativa para alimentação dos ruminantes.
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Steam injection is the most used thermal recovery method of oil nowadays because of the high degree of development of the technique that allows high recovery factors. However, injection of superheated steam into the reservoir affects the entire structure of the well, including the cemented layer that presents a retrogression of compressive strength and increases the permeability due to formation of more crystalline and denser phases at temperatures above 110 °C. These changes result in failures in the cement that favor the entrance of formation fluids into the annulus space resulting in unsafe operations and restrictions in the economic life of the well. But the strength retrogression can be prevented by partial replacement of cement by silica-based materials that reduce the CaO/SiO2 ratio of cement slurries changing the trajectory of the reactions, converting those deleterious phases in phases with satisfactory mechanical strength and permeability. The aim of this study was to evaluate the behavior of a ceramic waste material rich in silica in partial and total substitution of a mineral additive used to fight the strength retrogression of cement slurries subjected to high temperatures. The evaluation was made by compression, X-ray diffraction (XRD) and thermogravimetry (TG/DTG). The samples were submitted to a cycle of low temperature (38 °C) for 28 days and a cycle of low temperature followed by exposure to 280 ºC and 1000 psi by 3 days. The results showed that slurries with additions of up to 30% of the waste material are not enough to prevent the strength retrogression, while slurries with additions of the waste material combined with silica flour in various proportions produced hydrated products of low Ca/Si ratios that maintained the compressive strength at satisfactory levels
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Objetivo: En este estudio, el proceso de pelado de maíz con cal(PPC) fue documentado y sus parámetros optimizados mediante un diseño experimental, con el fin de conseguir un pelado completo del maíz con el mínimo grado de contaminación con fumonisinas. La presencia de fumonisina B1 (FB1) en el maíz fue analizada mediante HPLC-RP-FLD. Metodología: Los experimentos se realizaron a partir de un lote de maíz en grano seco conformado por submuestras provistas por agricultores seleccionados del cantón Nabón de la provincia del Azuay en base a un trabajo de investigación previo realizado por el proyecto VLIR-IUC, “Nutrición, Alimentación y Salud”. El diseño experimental fue divido en tres etapas: la caracterización de proceso, el mismo que se realizó mediante encuestas y observaciones in situ; pruebas de agotamiento de cal para el PPC, las que se realizaron partiendo de los datos recogidos en la primera etapa, y las pruebas de evaluación del PPC en la reducción de fumonisinas B1. Resultados y conclusiones: Se observó que, independiente de la concentración de cal utilizada, la etapa de pelado produjo una reducción de 8.73 veces la concentración de FB1 del maíz crudo (P=0.030), y que el maíz pelado y cocinado presentó una reducción de 9.14 veces (P=0.019). Recomendaciones: Se recomienda continuar con la experimentación para elucidar si la reducción de FB1se debió al proceso mecánico de remoción de la cáscara, o a la transformación química en su forma hidrolizada, por lo que este trabajo podría considerarse como un estudio explorativo preliminar.
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The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing
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Petroleum evaluation is analyze it using different methodologies, following international standards to know their chemical and physicochemical properties, contaminant levels, composition and especially their ability to generate derivatives. Many of these analyzes consuming a lot of time, large amount of samples , supplies and need an organized transportation logistics, schedule and professionals involved. Looking for alternatives that optimize the evaluation and enable the use of new technologies, seven samples of different centrifuged Brazilian oils previously characterized by Petrobras were analyzed by thermogravimetry in 25-900° C range using heating rates of 05, 10 and 20ºC per minute. With experimental data obtained, characterizations correlations were performed and provided: generation of true boiling point curves (TBP) simulated; comparing fractions generated with appropriate cut standard in temperature ranges; an approach to obtain Watson characterization factor; and compare micro carbon residue formed. The results showed a good chance of reproducing simulated TBP curve from thermogravimetry taking into account the composition, density and other oil properties. Proposed correlations for experimental characterization factor and carbon residue followed Petrobras characterizations, showing that thermogravimetry can be used as a tool on oil evaluation, because your quick analysis, accuracy, and requires a minimum number of samples and consumables
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2016
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2016