Comparação entre planejamento estatístico experimental e análise dimensional em operações de mistura e separação para sistema óleo-água

This work aims to determine a better methodology to help predicting some operational parameters to a new design of mixer-settler on treating wastewater produced by petroleum industry, called MDIF (Misturador-Decantador à Inversão de Fases/ Mixer-Settler based on Phase Inversion MSPI). The data from this research were obtained from the wastewater treatment unit, called MSPI-TU, installed on a wastewater treatment plant (WTP) of PETROBRAS/UO-RNCE. The importance in determining the better methodology to predict the results of separation and extraction efficiency of the equipment, contributes significantly to determine the optimum operating variables for the control of the unit. The study was based on a comparison among the experimental efficiency (E) obtained by operating MSPI-TU, the efficiency obtained by experimental design equation (Eplan) from the software Statistica Experimental Design® (version 7.0), and the other obtained from a modeling equation based on a dimensional analysis (Ecalc). The results shows that the experimental design equation gives a good prediction of the unit efficiencies with better data reliability, regarding to the condition before a run operation. The average deviation between the proposed by statistic planning model equation and experimental data was 0.13%. On the other hand, the efficiency calculated by the equation which represents the dimensional analysis, may result on important relative deviations (up 70%). Thus, the experimental design is confirmed as a reliable tool, with regard the experimental data processing of the MSPI-TU

Caracterização do comportamento geotécnico de mistura de resíduo de pneus e solo laterítico

A technological alternative for the correct disposal of tires is the use in the construction of embankment with soil and shredded tires. The use of waste tires in tropical soils requires prior knowledge of the properties and limitations of these materials. In this work, the results of an experimental program was devised to characterize the behavior of mixtures of waste tires and a lateritic soil. The residue used in this study is classified as tire buffings with an average size of 1.4 mm. The laboratory program included testing of particle size analysis, Atterberg limits, compaction, direct shear tests, permeability and confined compression tests with pure soil, pure tire and the mixtures. Proportions of 0% (pure soil), 10%, 20%, 40%, 50 % and 100% (pure tire) by weight were used. For the confining stress levels used in the study, the presence of tire residue provided a considerable increase in shear strength of the mixture. The maximum shear strength was obtained for a residue content of 40% by weight. Permeability tests on samples of waste under a confining stress of 100 kPa showed that the permeability increases significantly with increasing residue content until a residue content of 20%. The increase in permeability after that value showed to be negligible. Confined compression tests showed that the soil mixed with tire residue becomes more compressible than the pure soil. The secant constrained modulus (Msec) for the same vertical stress decreases with increasing percentage of residue.

Incorporação do lodo de tanque séptico como matéria-prima de uma mistura asfáltica

In Natal/RN, 68% of the population uses some kind of individual system for their domestic sewers treatment, being that the most used it is septic tank, followed by sumidouro. Every treatment system of sewers, usually used, generates a by-product denominated sludge. That residue presents some components, in its constitution, undesirable under the environmental and sanitary point of view. In such case, to assure that the system treatment has satisfactory results, it is necessary to do the adjusted disposition of the sludge sewage. Several countries are looking for technical alternatives for the use and disposition of residues. Under technical and environmental conditions appropriate, these materials can be used, decreasing the consumption of the natural resources and the treatment need, storage or elimination of the wastes, what decrease the risks created. Some of the alternatives of recycling of the sludge sewage are: the application in the agriculture, in the production of energy and as raw material in the civil construction. This study evaluated asphalt mixtures behavior that partially substituted conventional aggregates by septic tank sludge. The septic tank sludge gave origin to two raw materials called raw sludge and sludge ash. The raw sludge was put as a small aggregate and the sludge ash as filler. In the first experiment it was made a comparison between the mixture with conventional aggregates and the mixtures that replaced sand by raw sludge in the proportions from 5% to 40%. In the second experiment, it was made comparison between mixtures with 1%, 2% and 3% of sludge ash and cement. The stages developed along the study were: physical characterization of the conventional materials; physical, chemistry, thermal, mineralogical characterizations and analysis of environmental risk of the raw sludge; physical characterization and analysis of environmental risk of the sludge ash; analysis of the mixtures performance through its volumetric and mechanical characteristics; forecast of the mixtures susceptibility in the moisture presence. For the grain size composition used and with the percentage asphalt adopted, the mixtures with up to 7,5% of raw sludge in his composition attend to the National Department of Transports Infrastructure (DNIT) specifications. However, in agreement with the mixtures susceptibility in the moisture presence, the mixtures with addition of raw sludge don't present satisfactory acting. In such case, they could be used in arid and semi-arid areas. The raw sludge application in mixtures increased their voids volume and their stability. However, it damaged mixtures adhesiveness. Mixtures with sludge ash and with cement presented similar behavior. However, mixtures with sludge ash presented a better performance than mixtures with cement as for their stability and their tensile strength ratio. The mixture with 1% of sludge ash is better. The wastes studied don't represent environmental risk

Estudos de sinterização da mistura de pós cerâmicos diatomita-titânia

This work is part of an effort of consolidation of a daily search for powder technology at the Department of Physics of the Universidade Federal do Rio Grande do Norte. This work objective the study and development of new ceramic materials from raw materials abundant at the region. For this, were studied ceramic mixtures of powders from diatomite-titania to aiming at a new ceramic material from powder technology. The experimental work involved a characterization of ceramic powders from a diatomite-titania mixture. The powders obtained were pressed and then parameters like variation of mass, linear shrinkage, activation energy and the mechanism of sintering are studied in function of the time and temperature of sintering, beyond microstructural analysis. The obtained results allow us estimate the optimizing of sintering conditions of this material

Estudo da viabilização do uso da mistura híbrida ferrocarbonila / ferrita de NI0,5Zn0,5Fe2o4 como material absorvedor de radiação eletromagnética

Were synthesized ferrites of NiZn on systems Ni0,5Zn0,5Fe2O4, the precursors citrate method. The decomposition of the precursors was studied by thermogravimetric analysis and spectroscopy in the infrared region, the temperature of 350°C/3h. The evolution of the phases formed after calcinations at 350ºC/3h, 600, 1000 and 1100ºC/2h was accompanied by X-ray diffraction using the Rietveld refinement method for better identification os structures formed. Was observed for samples calcined at different temperatures increased crystallinity with increasing calcination temperature, being observed for the samples calcined at 900 and 1100 º C/2h was the precipitation of a secondary phase, the phase hematite. The ferrocarbonila of industrial origin was analyzed by X-ray diffraction and Rietveld for the identification of its structure. The carbonyl iron was added NiZn ferrite calcined at 350ºC/3h, 600, 900, 1000 and 1100ºC/2h to the formation of hybrid mixtures. They were then analyzed by Xray diffraction and Rietveld. The NiZn ferrite and ferrocarbonila as well as the hybrid mixtures were subjected to analysis of scanning electron microscopy, magnetic measurements and reflectivity. The magnetic measurements indicated that the ferrite, the ferrocarbonila, as well as hybrid mixtures showed characteristics of soft magnetic material. The addition of ferrocarbonila in all compositions showed an increase in the results of magnetic measurements and reflectivity. Best result was observed in the increase of the magnetization for the hybrid mixture of Ferrocarbonila / ferrite of NiZn calcined at 600ºC/2h. The mixture Ferrocarbonila / ferrite calcined 1000°C/2h presented better absorption of electromagnetic radiation in the microwave

Estudo da mistura comercial dolomita-quartzo, dopada com Hg(I), Cd(II) e Cr(III), para adsorção de H2S

The present work was to carry out a study on the adsorption of hydrogen sulfide (H2S) in arrays synthesized from a commercial clay mineral formed by a mixture of dolomite and quartz. To produce the ion exchange matrix were made using aqueous solutions of salts of cobalt II chloride hexahydrate (CoCl2.6H2O) II cadmium nitrate tetrahydrate (Cd (NO3)2.4H2O) I mercuric chloride (HgCl) nitrate and chromium III pentahydrate (Cr (NO3)3.5H2O). The arrays were subjected to hydrogen sulphide gas passage for one hour. To check the amount of gas adsorbed was used gravimetric process. The best result was in the adsorption matrix doped with cadmium and the solution retained for a longer time than the largest amount of H2S was the cobalt matrix. The matrix unmodified exhibited poor adsorption capacity. The characterization of the matrices were used XRD, XRF and IV. Mother with cadmium showed a high capacity in ion exchange, because the percentage of cadmium increased from 0% to 81.38% by replacing atoms of calcium and silicon which increased from 96.54% to 17.56% and 15, 72% to 0.32%, respectively, but also the best performance in adsorption of H2S adsorbing 11.89507 mg per gram of matrix

Mistura de proteínas morfogenéticas ósseas, hidroxiapatita, osso inorgânico e colágeno envolta por membrana de pericárdio no preenchimento de defeito ósseo segmentar em coelhos

Avaliou-se o uso de biomaterial de origem bovina na regeneração de defeitos ósseos segmentares empregando-se 12 coelhos, fêmeas, da raça Norfolk, com idade de seis meses e pesos entre 3 e 4,5kg. Realizou-se falha segmentar bilateral de um centímetro de comprimento na diáfise do rádio, com inclusão do periósteo. No membro direito, o defeito foi delimitado por membrana de pericárdio liofilizada, contendo em seu interior mistura de proteínas morfogenéticas ósseas adsorvidas a hidroxiapatita, colágeno liofilizado e osso inorgânico. No membro esquerdo, o defeito não recebeu tratamento. Radiografias foram obtidas ao término do procedimento cirúrgico e aos sete, 30, 60, 90, 120 e 150 dias de pós-operatório. Após eutanásia de seis coelhos aos 60 dias e seis aos 150 dias de pós-cirúrgico, os resultados radiográficos e histológicos mostraram que a regeneração óssea foi inibida nos defeitos segmentares tratados com o biomaterial.

Volume do recipiente, adubação e sua forma de mistura ao substrato no crescimento inicial de Peltophorum dubium (sprengel) taubert em viveiro

O ensaio comparou três volumes de recipientes, três tipos de adubação e duas formas de mistura do fertilizante ao substrato, no crescimento inicial de plântulas de Peltophorum dubium (Sprengel) Taubert (canafístula) em viveiro, num esquema fatorial 3 x 3 x 2. Foram utilizados tubetes de 100 e 180 cm³ preenchidos com substrato comercial e sacos plásticos de 10 x 15 cm cheios com mistura de solo e vermiculita em partes iguais, fertilizados com fertilizante de liberação lenta (FLL) nas dosagens de 1,75 e 3,5 kg m-3 e com formulação NPK a 1,0 kg m-3 de substrato. As formas de misturas adotadas foram aquelas com base por metro cúbico de substrato ou individualmente para cada recipiente. Na análise destrutiva realizada 12 semanas após a emergência, avaliaram-se o número de folhas, a altura da planta, o diâmetro do coleto e as massas secas da parte aérea, o sistema radicular e o total. Os resultados indicaram que a redução no volume do recipiente causou diminuição na massa seca, diâmetro e altura. O número de folhas, a massa seca da parte aérea e a massa seca total foram semelhantes nas plântulas sob fertilização com NPK, independentemente do volume do recipiente, o que não ocorreu naquelas sob FLL, onde esse parâmetro diminuiu com o volume do recipiente. O cálculo do índice de Dickson após 12 semanas indicou valores superiores em mudas com a forma de mistura convencional em relação à individual e maior naquelas sob fertilização com NPK, em comparação com as sob FLL.

Controle de dez espécies daninhas em cana-de-açúcar com o herbicida mesotrione em mistura com ametryn e metribuzin

Existem muitas opções de herbicidas para aplicações em pré-emergência em cana-de-açúcar, mas o grande desafio atual para a cultura é o controle pós-emergente. O objetivo deste trabalho foi avaliar a eficácia do herbicida mesotrione em mistura com ametryn e metribuzin no controle em pós-emergência de 10 espécies daninhas semeadas em cana-de-açúcar, variedade RB 86-7515. As espécies daninhas selecionadas para o experimento foram: Brachiaria decumbens, Brachiaria plantaginea, Cenchrus echinatus, Digitaria horizontalis, Panicum maximum, Amaranthus deflexus, Bidens pilosa, Euphorbia heterophylla, Ipomoea nil e Sida glaziovii, semeadas nas entrelinhas após a emergência da cultura. Os herbicidas foram aplicados aos 45 dias após o plantio da cana-de-açúcar, com as plantas daninhas monocotiledôneas na fase de terceiro perfilho e as dicotiledôneas com três a quatro pares de folhas, e constaram dos seguintes tratamentos: mesotrione (120 g ha-1); ametryn (2.000 g ha-1); metribuzin (1.920 g ha-1); mesotrione + ametryn (120 g + 2.000 g ha-1); mesotrione + metribuzin (120 g + 1920 g ha-1) e testemunhas no mato e no limpo. Concluiu-se que os herbicidas isolados ou em mistura foram seletivos à cana-de-açúcar. Com relação à eficácia, observou-se que o herbicida mesotrione foi eficiente no controle de A. deflexus; ametryn, no controle de A. deflexus, B. pilosa e I. nil; metribuzin, no controle de A. deflexus, B. pilosa e S. glaziovii; mesotrione + ametryn, no controle de B. decumbens, B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa, I. nil e S. glaziovii; e mesotrione + metribuzin, no controle de B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa e S. glaziovii. Foi constatado elevado efeito sinergístico do mesotrione com os herbicidas testados, sendo o efeito mais pronunciado na mistura com o ametryn.

Consumo, desempenho e parâmetros econômicos de novilhos Nelore e F1 Brangus x Nelore terminados em pastagens, suplementados com mistura mineral e sal nitrogenado com uréia ou amiréia

Avaliou-se o efeito da suplementação protéica (40% PB) com amiréia ou uréia sobre o consumo de suplemento, desempenho e características econômicas de novilhos terminados em pastagens. Foram utilizados 120 novilhos com 19 meses de idade e 358kg, sendo 60 Nelore e 60 F1 Brangus x Nelore, divididos em três tratamentos com 20 animais, alojados em piquetes de Brachiaria brizantha cv. Marandu de 10 hectares cada, totalizando 120 hectares, sendo dois piquetes por grupo genético e tratamento, pastejados alternadamente a cada pesagem (42 dias). Os tratamentos consistiram em mistura mineral com amiréia-150S (AM), mistura mineral com uréia+milho+enxofre (UR) e mistura mineral (MM). As médias de consumo de suplemento dos animais F1 foram de 206,1; 145,9 e 73,1g/dia, e as dos animais Nelore, 236,0; 205,1 e 94,3g/dia para os tratamentos AM, UR e MM, respectivamente. Para os novilhos Nelore, houve efeito (P<0,05) do suplemento sobre o peso de abate (PA), sendo a média do tratamento UR, 518,85kg, mais alta que a dos demais, 491,89 e 485,20kg, respectivamente, para AM e MM. Para os novilhos F1, foi significativo o efeito da suplementação protéica (P<0,05), com médias de 515,90 e 520,15kg, respectivamente, para os tratamentos UR e AM. A suplementação protéica proporcionou bom desempenho em animais F1 durante períodos de abundância de forragem. O uso de uréia apresentou melhor viabilidade econômica.

Influência da relação superfície/volume e do tempo de fritura sobre as alterações da mistura azeite de dendê-óleo de soja

Objetivou-se com este estudo determinar a influência dos fatores relação superfície/volume (S/V) e tempo de fritura sobre a alteração da mistura azeite de dendê-óleo de soja em frituras descontínuas de batatas chips.Foram realizados dois procedimentos de fritura com relações S/V de 0,5 e 1,0 cm-1 e temperatura média de 180°C. O óleo foi aquecido por um período de 7,25 horas. As amostras obtidas durante o processo de fritura foram analisadas pelas determinações de índice de peróxidos, compostos polares totais, ácidos graxos livres e índice de refração. Todas as determinações analíticas foram influenciadas pelo tempo de fritura, verificando-se aumentos significativos destes parâmetros ao longo do processo de fritura. O fator relação S/V apresentou influência sobre os valores dos índices de peróxidos e de refração. A mistura azeite de dendê-óleo de soja apresentou alteração acima do limite recomendado para óleos de fritura (compostos polares totais > 25%) a partir de 6,25 horas de fritura.

Sinterização de uma mistura de cavaco de aço inoxidável com pó do mesmo material. Uma nova tecnologia para a reciclagem de metais?

The reuse of materials has as its main objective to minimize environmental impacts and to rationalize the use of energy chains. In the present work, samples of scraps of 316 stainless steel mixed with powder of the same material were sintered. For this case, the percentage of scrap was varied from zero to 25% in weight, with 5% increases. After compacting, under a pressure of 600MPa, the samples were sintered simultaneously at a temperature of 1473 K. The mechanical behavior of the final product was evaluated through Assays of Transversal Rupture recommended and normalized by the MPIF - Metal Powder Industries Federation. Using Conventional Quantitative Metallography, the analyses of the sintered samples demonstrated regions of intense diffusion, therefore, regions of sufficiently intense sintering. The mechanical resistance of the samples was compared with the mechanical resistance of the sintered stainless steel with no scrap. The results were greater than expected, demonstrating the viability of this new procedure.

Eficácia da mistura de glifosato a outros maturadores na cana-de-açúcar (Saccharum spp.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização vetorial e técnicas de mistura de herbicidas aplicadas ao controle de plantas daninhas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo por dinâmica molecular da estabilidade conformacional de dímeros do peptídeo Eumenine mastoparan-AF em água e mistura TFE-água

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)