Estimativas da condutividade térmica dos minerais e rochas e influência de parâmetros térmicos e petrofísicos na resistividade aparente da formação

O presente estudo realiza estimativas da condutividade térmica dos principais minerais formadores de rochas, bem como estimativas da condutividade média da fase sólida de cinco litologias básicas (arenitos, calcários, dolomitos, anidritas e litologias argilosas). Alguns modelos térmicos foram comparados entre si, possibilitando a verificação daquele mais apropriado para representar o agregado de minerais e fluidos que compõem as rochas. Os resultados obtidos podem ser aplicados a modelamentos térmicos os mais variados. A metodologia empregada baseia-se em um algoritmo de regressão não-linear denominado de Busca Aleatória Controlada. O comportamento do algoritmo é avaliado para dados sintéticos antes de ser usado em dados reais. O modelo usado na regressão para obter a condutividade térmica dos minerais é o modelo geométrico médio. O método de regressão, usado em cada subconjunto litológico, forneceu os seguintes valores para a condutividade térmica média da fase sólida: arenitos 5,9 ± 1,33 W/mK, calcários 3.1 ± 0.12 W/mK, dolomitos 4.7 ± 0.56 W/mK, anidritas 6.3 ± 0.27 W/mK e para litologias argilosas 3.4 ± 0.48 W/mK. Na sequência, são fornecidas as bases para o estudo da difusão do calor em coordenadas cilíndricas, considerando o efeito de invasão do filtrado da lama na formação, através de uma adaptação da simulação de injeção de poços proveniente das teorias relativas à engenharia de reservatório. Com isto, estimam-se os erros relativos sobre a resistividade aparente assumindo como referência a temperatura original da formação. Nesta etapa do trabalho, faz-se uso do método de diferenças finitas para avaliar a distribuição de temperatura poço-formação. A simulação da invasão é realizada, em coordenadas cilíndricas, através da adaptação da equação de Buckley-Leverett em coordenadas cartesianas. Efeitos como o aparecimento do reboco de lama na parede do poço, gravidade e pressão capilar não são levados em consideração. A partir das distribuições de saturação e temperatura, obtém-se a distribuição radial de resistividade, a qual é convolvida com a resposta radial da ferramenta de indução (transmissor-receptor) resultando na resistividade aparente da formação. Admitindo como referência a temperatura original da formação, são obtidos os erros relativos da resistividade aparente. Através da variação de alguns parâmetros, verifica-se que a porosidade e a saturação original da formação podem ser responsáveis por enormes erros na obtenção da resistividade, principalmente se tais "leituras" forem realizadas logo após a perfuração (MWD). A diferença de temperatura entre poço e formação é a principal causadora de tais erros, indicando que em situações onde esta diferença de temperatura seja grande, perfilagens com ferramentas de indução devam ser realizadas de um a dois dias após a perfuração do poço.

Efeito da implantação iônica por imersão em plasma no aço ferramenta tipo H13

Pós-graduação em Engenharia Mecânica - FEG

Efeito da implantação iônica por imersão em plasmas sobre a bioatividade de titânio

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

Teste de condutividade elétrica em sementes de Bowdichia virgilioides Kunth

The aim of this study was to adapt the methodology of electrical conductivity (EC) test and determine the physiological quality of seeds of B. virgilioides. Seeds were separated into three batches according to tegument color (1-yellow, 2-orange, and 3-red/black). The EC test analyzed three quantities of seeds (25, 50 and 100), three volumes of water (25, 50 and 100 mL), and six times of seed imbibition (12, 24, 36, 48, 60 and 72), at 25 °C with 6 replications. Germination test was employed to compare the results. The EC test allowed the differentiation of batches in three levels of vigor - the same was observed in germination test: batch 1 presented the best seed vigor, followed by batches 2 and 3. The use of 25, 50 or 100 seeds imbibed in 50 mL of water for 24 hours is recommended.

Processo de obtenção de membrana condutora iônica de celulose bacteriana e produto obtido

É descrita a invenção de um processo de obtenção de membrana de celulose bacteriana iônica que utiliza membrana de celulose bacteriana como matriz polimérica para obtenção de materiais poliméricos condutores iônicos.

Tratamento químico de sementes de milho e o teste de condutividade elétrica

In different crops, the seeds treatment with the use of fungicides and/or insecticides has been performed before the storage or in the seeding moment as a guarantee form of longer conservation period and adequate initial stand. However, it is not known if the various products used for the treatment interfere with test results of electrical conductivity of corn seeds. The experimental design was completely randomized and the analysis carried out in a factorial 5x5x2 with four replications. The treatments consisted of five cultivars of corn (DKB 390YG, DKB 185YG, 2B710, AGN-30A91HX and AL Bandeirante) treated with four insecticides (imidacloprid+thiodicarbe, thiamethoxam, fipronil, fipronil+piraclostrobin+thiophanate-methyl), and the control previously treated by the company with fungicides (fludioxonil+metalaxyl-M e captan) and insecticides (pirimiphos-methyl, deltamethrin e bifenthrin), analyzed in two different times (after treatment and at 35 days of storage). Seeds were subjected to tests of germination, electrical conductivity and water content. The results showed that the treatment of corn seeds with insecticides and fungicides doesn't interfere on the test results of electric conductivity, even if the analysis is made after 35 days of storage of seeds.

Desenvolvimento e teste de um sistema para separação automática das fases glicerol-biodiesel utilizando sensor de condutividade elétrica

Pós-graduação em Engenharia Mecânica - FEIS

Mapeamento da condutividade hidráulica da cobertura do aquífero Guarani, situado na bacia hidrográfica dos rios Jacaré-Guaçú e Jacaré-Pepira, na porção centro-norte do estado de São Paulo

Given the importance of preserving the water quality of the Guarani Aquifer, the work done in the hydrographic basin of the rivers Jacaré-Guaçú e Jacaré-Pepira, located in the central-northern São Paulo state, was made to map the hydraulic conductivity from the use of some empirical methods associated with granulometric analysis and in situ testing, specifically with the Guelph permeameter. All results were submitted to a correlation analysis and subsequently mapped using the methodology of minimum curvature, based on numerical techniques Spline. These procedures provide for studies of aquifer vulnerability and assist in decision making in environmental projects and guidelines for urban planning

Implantação iônica por imersão em plasma e deposição de filmes finos poliméricos provenientes da mistura hexametildisilazano/argônio

Thin polymeric films deposited by plasma are very atractive for many industrial and scientific applications, in areas such as electronics, mechanics, coatings, biomaterials, among others, due to its favorable properties such as good adhesion to the substrate, high crosslinking, nanomectric thickness, homogeneity, etc. In this work, thin films were deposited by plasma immersion ion implantation and deposition technique from a hexamethyldisilazane/argon mixture at different proportions. These films were subjected to several characterizations, such as, contact angle, which presented values near to 100 degrees, surface energy, with values near to 31 mJ/m2, hardness with values between 0.7 and 2.6 GPa, thickness from 100 to 200 nm, refractive index from 1.56 to 1.64, molecular structure presenting the following functional groups in the infrared spectra region: CHx from 2960 to 2900 cm-1; Si-H around 2130 cm-1; CH3 in Si-(CH3)x around 1410 cm-1; CH3 in Si-(CH3)x in 1260 cm-1; N-H around 1180 cm-1; CH2 in Si-CH2-Si bonds around 1025 cm-1; Si-O in Si-O-Si from 1020 to 1100 cm-1; Si-N in Si-H-Si bonds around 940 cm-1; CH3 in Si-(CH3)3 in 850 cm-1; Si-C bonds in Si-(CH3)2 around 800 cm-1; and Si-H in 680 cm-1 . From these characterizations, it was possible to conclude that the concentration of argon or hexamethyldisilazane in the mixture changed the resulting polymer

Estudo da superfície de fibras de carbono após tratamento de implantação iônica por imersão em plasma (3IP)

In this work, plasma immersion ion implantation (PIII) treatments of carbon fibers (CFs) were performed in order to induce modifications of chemical and physical properties of the CF surface aimed to improve the performance of thermoplastic composite. The samples to be treated were immersed in nitrogen or air glow discharge plasma and pulsed at −3.0 kV for 2.0, 5.0, 10.0, and 15.0 min. After PIII processing, the specimens were characterized by atomic force microscopy (AFM), scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). After CFs treatments, the CF/Polypropylene (PP) composites were produced by hot pressing method. Surface morphology of as-received CFs exhibited some scratches aligned along the fibers due to the fiber manufacturing process. After both treatments, these features became deeper, and also, a number of small particles nonuniformly distributed on the fiber surface can be observed. These particles are product of CF surface sputtering during the PIII treatment, which removes the epoxy layer that covers as-received samples. AFM analyses of CF samples treated with nitrogen depicted a large increase of the surface roughness (Rrms value approximately six times higher than that of the untreated sample). The increase of the roughness was also observed for samples treated by air PIII. Raman spectra of all samples presented the characteristic D- and G-bands at approximately 1355 and 1582 cm−1, respectively. Analysis of the surface chemical composition provided by the XPS showed that nitrogen and oxygen were incorporated onto the surface. The polar radicals formed on the surface lead to increasing of the CF surface energy. Both the modification of surface roughness and the surface oxidation contributed for the enhancement of CF adhesion to the polymeric matrix. These features were confirmed ... (Complete abstract click electronic access below)

Fadiga axial do aço inoxidável 15-5 PH tratado pela implantação iônica por imersão em plasma

When materials for application in aircraft structural components are studied, it must be considered that they will be submitted to cyclic loading, and this is an important parameter to design the study in fatigue life of the materials. Whereas, for example, a landing gear operation, the study of fatigue life and corrosion in the materials used in it is essential, especially when you want to use new techniques for surface treatments. The objective is to study the influence of surface treatment of immersion ion implantation nitrogen plasma, in axial fatigue of Stainless steel 15-5 PH in 39-42 HRC condition. Stainless steel 15-5 PH was tested in axial fatigue and corrosion in salt spray. It was also performed microindentation tests, optical microscopy for microstructural analysis and scanning electron microscopy for fractographic analysis. It was observed that the 3IP had no effect on the thickness of the material and not the hardness of it, and still provided a significant increase in fatigue life of the material

Condutividade hidráulica saturada e direcional em xisto: ensaios em laboratório. -

Pós-graduação em Geociências e Meio Ambiente - IGCE

Estudo da superfície do carbono vítreo reticulado após tratamento de implantação iônica por imersão em plasma (3IP) para a obtenção de eletrodos

In this work, RVC samples were treated by plasma immersion ion implantation (PIII) for electrodes production. High-voltage pulses with amplitudes of -3.0 kV or -10.0 kV were applied to the RVC samples while the treatment time was 10, 20 and 30 minutes. Nitrogen, atmospheric air and H2:N2 mixture were employed as plasma sources. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The SEM images present an apparent enhancement of the surface roughness after the treatment probably due to the surface sputtering during the PIII process. This observation is in agreement with the specific electrochemical surface area (SESA) of RVC electrodes. An increase was observed of the SESA values for the PIII treated samples compared to the untreated specimen. Some oxygen and nitrogen containing groups were introduced on the RVC surface after the PIII treatment. Both plasma-induced process: the surface roughening and the introduction of the polar species on the RVC surface are beneficial for the RVC electrodes application

Estudo da condutividade elétrica em filmes finos de derivados de politiofeno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manejo da fertirrigação e salinidade do solo no crescimento da cultura da beterraba

With the increase in world population and scarcity of natural resources, efficient use of fertilizers becomes necessary for intensive agriculture. The experiment was conducted in a greenhouse at the Department of Agricultural Engineering, UNESP in Botucatu-SP. The treatments were derived from the combination of the soil salinity (E.C: 1.0, 3.0, 6.0, 9.0 and 12.0 dS m-1), Fertigation management (M1 =traditional and M2 = with control of the ionic concentration of the soil solution) and beet cultivars (C1= Early Wonder and C2 = Itapuã) in a 5x2x2 factorial design with four replications in a randomized block design. Throughout the cultivation, the following variables were evaluated: height, stem diameter, length and diameter of plant roots. The height of the plant presented differently according to the Fertigation management and sensitive to levels of electrical conductivity in the soil. The diameter of the roots showed reductions of 3.55 and 2.48 mm for C1 and C2, respectively, every unit increase in electrical conductivity (EC) to M1. Based on the functional relationship of the best adjustment between the diameter of the roots and electrical conductivity in M2 gave an estimated maximum diameter of 90.78 mm to 94.67 mm for C1 and C2.