Contribuição da poliacrilamida parcialmente hidrolisada em associação com a bentonita em fluidos de perfuração aquosos

In this study, we investigated the effect of addition of partially hydrolyzed polyacrylamide (HPAM) and bentonite in the physicochemical properties of acquous drilling fluids. Two formulations were evaluated: F1 formulation, which was used as reference, containing carboxymethylcellulose (CMC), magnesium oxide (MgO), calcite (calcium carbonate - CaCO3 ), xanthan gum, sodium chloride (NaCl) and triazine (bactericidal); and F2, containig HPAM steady of CMC and bentonite in substituition of calcite. The prepared fluids were characterized by rheological properties, lubricity and fluid loss. Calcite was characterized by granulometry and thermal gravimetric analysis (TGA). The formulation F2 presented filtration control at 93◦C 34 mL while F1 had total filtration. The lubricity coefficient was 0.1623 for F2 and 0.2542 for F1, causing reduction in torque of 25% for F1 and 52 % for F2, compared to water. In the temperature of 49 ◦C and shear rate of 1022 s −1 , the apparent viscosities were 25, 5 and 48 cP for F1 and F2 formulation, respectively, showing greater thermal resistance to F2. With the confirmation of higher thermal stability of F2, factorial design was conducted in order to determine the HPAM and of bentonite concentrations that resulted in the better performance of the fluids. The statistical design response surfaces indicated the best concentrations of HPAM (4.3g/L) and bentonite (28.5 g/L) to achieve improved properties of the fluids (apparent viscosity, plastic viscosity, yield point and fluid loss) with 95% confidence, as well as the correlations between these factors (HPAM and bentonite concentrations). The thermal aging tests indicated that the formulations containing HPAM and bentonite may be used to the maximum temperature until 150 ◦C. The analyze of the filter cake formed after filtration of fluids by X-ray diffraction showed specific interactions between the bentonite and HPAM, explaining the greater thermal stability of F2 compared to the fluid F1, that supports maximum temperature of 93 ◦C.

Modelagem matemática e experimental da perda de injetividade em poços canhoneados

Water injection in oil reservoirs is a recovery technique widely used for oil recovery. However, the injected water contains suspended particles that can be trapped, causing formation damage and injectivity decline. In such cases, it is necessary to stimulate the damaged formation looking forward to restore the injectivity of the injection wells. Injectivity decline causes a major negative impact to the economy of oil production, which is why, it is important to foresee the injectivity behavior for a good waterflooding management project. Mathematical models for injectivity losses allow studying the effect of the injected water quality, also the well and formation characteristics. Therefore, a mathematical model of injectivity losses for perforated injection wells was developed. The scientific novelty of this work relates to the modeling and prediction of injectivity decline in perforated injection wells, considering deep filtration and the formation of external cake in spheroidal perforations. The classic modeling for deep filtration was rewritten using spheroidal coordinates. The solution to the concentration of suspended particles was obtained analytically and the concentration of the retained particles, which cause formation damage, was solved numerically. The acquisition of the solution to impedance assumed a constant injection rate and the modified Darcy´s Law, defined as being the inverse of the normalized injectivity by the inverse of the initial injectivity. Finally, classic linear flow injectivity tests were performed within Berea sandstone samples, and within perforated samples. The parameters of the model, filtration and formation damage coefficients, obtained from the data, were used to verify the proposed modeling. The simulations showed a good fit to the experimental data, it was observed that the ratio between the particle size and pore has a large influence on the behavior of injectivity decline.

Distribution, density and abundance of Antarctic ice seals off Queen Maud Land and the eastern Weddell Sea

The Antarctic Pack Ice Seal (APIS) Program was initiated in 1994 to estimate the abundance of four species of Antarctic phocids: the crabeater seal Lobodon carcinophaga, Weddell seal Leptonychotes weddellii, Ross seal Ommatophoca rossii and leopard seal Hydrurga leptonyx and to identify ecological relationships and habitat use patterns. The Atlantic sector of the Southern Ocean (the eastern sector of the Weddell Sea) was surveyed by research teams from Germany, Norway and South Africa using a range of aerial methods over five austral summers between 1996-1997 and 2000-2001. We used these observations to model densities of seals in the area, taking into account haul-out probabilities, survey-specific sighting probabilities and covariates derived from satellite-based ice concentrations and bathymetry. These models predicted the total abundance over the area bounded by the surveys (30°W and 10°E). In this sector of the coast, we estimated seal abundances of: 514 (95 % CI 337-886) x 10**3 crabeater seals, 60.0 (43.2-94.4) x 10**3 Weddell seals and 13.2 (5.50-39.7) x 10**3 leopard seals. The crabeater seal densities, approximately 14,000 seals per degree longitude, are similar to estimates obtained by surveys in the Pacific and Indian sectors by other APIS researchers. Very few Ross seals were observed (24 total), leading to a conservative estimate of 830 (119-2894) individuals over the study area. These results provide an important baseline against which to compare future changes in seal distribution and abundance.

Fontes de matéria orgânica para a formulação de fertilizantes organominerais peletizados no desenvolvimento da cultura do sorgo

Organo-mineral fertilizers have been used to both meet plants’ nutritional needs and reduce producers’ reliance on mineral fertilizers. This practice improves both the use of nutrients by plants and the soil structure due to the organic matter in these fertilizers. This study aimed to determine the effect of organic matter sources in the composition of organomineral fertilizers and compare it to the effect of traditional mineral fertilizers when it comes to the initial development of sorghum. Research was carried out in a greenhouse at the Federal University of Uberlandia, in Uberlandia, Minas Gerais, Brazil. Sorghum seeds of grain-bearing simple hybrid 1G100 were used in the seeding process. The experiment followed a randomized complete block design in a 4 x 3 + 2 factorial arrangement. Factors included four levels (50, 75, 100 and 125% of 450 kg ha-1, which is the recommended dose for sorghum crops), three organic matter sources in the composition of the organomineral fertilizers (sewage sludge, filter cake, and peat), a control (100% mineral fertilizer), and an untreated check (no fertilizers). Each experimental plot consisted of four plants divided into two pots. Oxisol was used in all pots. Analyses were performed at 30 and 60 days after seeding (DAS) and targeted: plant height, stem diameter, chlorophyll A, chlorophyll B, and leaf area. After this period, plants were removed from the soil, and had their aerial parts isolated to be dried in an air-forced oven before measurement of their dry mass. Means of the organomineral fertilizers outperformed those of both control and untreated check plots in almost all variables at 30 DAS. The only exception was variable stem diameter, in which organomineral fertilizers outperformed untreated check plots only. Sorghum fertilized with organomineral fertilizers also showed positive results in the variables analyzed at 60 DAS: even with dose reduction, their means were similar to those found in control plots. Organomineral fertilizers had higher means in some variables, such as diameter and dry mass of the aerial part, than both control and untreated check plots. In the conditions set in this study and considering the variables herein reported, organomineral fertilizers can substitute mineral fertilizers in the initial development of sorghum, even with some dose reductions.

Using food intake records to estimate compliance with the Eatwell plate dietary guidelines

Funded by Scottish Government's Rural and Environment Science and Analytical Services (RESAS) Division Food Standards Agency, UK Biscuit, Cake, Chocolate and Confectionery Association, London, UK

Using food intake records to estimate compliance with the Eatwell plate dietary guidelines

Funded by Scottish Government's Rural and Environment Science and Analytical Services (RESAS) Division Food Standards Agency, UK Biscuit, Cake, Chocolate and Confectionery Association, London, UK

Adieu New York, bonjour Paris ! : l es enjeux esthétiques et culturels des appropriations du jazz dans le monde musical savant français (1900-1930)

Thèse réalisée en cotutelle avec l'Université Paris-Sorbonne et l'Université de Montréal. Composition du jury : M. Laurent Cugny (Université Paris-Sorbonne) ; M. Michel Duchesneau (Université de Montréal) ; M. Philippe Gumplowicz (Université d'Evry-Val d'Essonne) ; Mme Barbara Kelly (Keele University - Royal Northern College of Music) ; M. François de Médicis (Université de Montréal) ; M. Christopher Moore (Université d'Ottawa)

Big Data Analysis in Social Networks : Extracting Food Preferences of Vegans from Twitter

Market research is often conducted through conventional methods such as surveys, focus groups and interviews. But the drawbacks of these methods are that they can be costly and timeconsuming. This study develops a new method, based on a combination of standard techniques like sentiment analysis and normalisation, to conduct market research in a manner that is free and quick. The method can be used in many application-areas, but this study focuses mainly on the veganism market to identify vegan food preferences in the form of a profile. Several food words are identified, along with their distribution between positive and negative sentiments in the profile. Surprisingly, non-vegan foods such as cheese, cake, milk, pizza and chicken dominate the profile, indicating that there is a significant market for vegan-suitable alternatives for such foods. Meanwhile, vegan-suitable foods such as coconut, potato, blueberries, kale and tofu also make strong appearances in the profile. Validation is performed by using the method on Volkswagen vehicle data to identify positive and negative sentiment across five car models. Some results were found to be consistent with sales figures and expert reviews, while others were inconsistent. The reliability of the method is therefore questionable, so the results should be used with caution.

Improving Wood Fuel Pellets for Household Use : Perspectives on Quality, Efficiency and Environment

Bioenergy is one of many contributors to reducing the use of fossil fuels in order to mitigate climate change by decreasing CO2-emissions, and the potential for biofuels are large. The wood fuel pellets are a refined biofuel made of sawdust, which is dried and compressed to achieve improved fuel and transportation properties. In 2007 the amount of wood fuel pellets used for heating purposes in Sweden was 1715000 tons. The aims of this work was: to examine the moisture content and emission of monoterpenes during the drying and pelletising steps of the pellets production (Paper I); to investigate how the recirculation of drying gases affects the energy efficiency of rotary dryers and how the energy efficiency is related to the capacity of the dryer. (Paper II); to analyse the causes of the problems encountered by household end-users of pellets and investigate whether an improved pellet quality standard could reduce these problems (Paper III); to investigate how the energy consumption of the pelletising machine and chosen pellet quality parameters were affected using an increased amount of rapeseed cake in wood fuel pellets (Paper IV); and to identify gaps of knowledge about wood fuel pellet technology and needs for further research on quality, environmental and health aspects throughout the wood fuel pellet chain, from sawdust to heat. (Paper V).

New biomass derived carbon catalysts for biomass valorization

Due to diminishing petroleum reserves, unsteady market situation and the environmental concerns associated with utilization of fossil resources, the utilization of renewables for production of energy and chemicals (biorefining) has gained considerable attention. Biomass is the only sustainable source of organic compounds that has been proposed as petroleum equivalent for the production of fuels, chemicals and materials. In fact, it would not be wrong to say that the only viable answer to sustainably convene our future energy and material requirements remain with a bio-based economy with biomass based industries and products. This has prompted biomass valorization (biorefining) to become an important area of industrial research. While many disciplines of science are involved in the realization of this effort, catalysis and knowledge of chemical technology are considered to be particularly important to eventually render this dream to come true. Traditionally, the catalyst research for biomass conversion has been focused primarily on commercially available catalysts like zeolites, silica and various metals (Pt, Pd, Au, Ni) supported on zeolites, silica etc. Nevertheless, the main drawbacks of these catalysts are coupled with high material cost, low activity, limited reusability etc. – all facts that render them less attractive in industrial scale applications (poor activity for the price). Thus, there is a particular need to develop active, robust and cost efficient catalytic systems capable of converting complex biomass molecules. Saccharification, esterification, transesterification and acetylation are important chemical processes in the valorization chain of biomasses (and several biomass components) for production of platform chemicals, transportation fuels, food additives and materials. In the current work, various novel acidic carbons were synthesized from wastes generated from biodiesel and allied industries, and employed as catalysts in the aforementioned reactions. The structure and surface properties of the novel materials were investigated by XRD, XPS, elemental analysis, SEM, TEM, TPD and N2-physisorption techniques. The agro-industrial waste derived sulfonic acid functionalized novel carbons exhibit excellent catalytic activity in the aforementioned reactions and easily outperformed liquid H2SO4 and conventional solid acids (zeolites, ion-exchange resins etc). The experimental results indicated strong influence of catalyst pore-structure (pore size, pore-volume), concentration of –SO3H groups and surface properties in terms of the activity and selectivity of these catalysts. Here, a large pore catalyst with high –SO3H density exhibited the highest esterification and transesterification activity, and was successfully employed in biodiesel production from fatty acids and low grade acidic oils. Also, a catalyst decay model was proposed upon biodiesel production and could explain that the catalyst loses its activity mainly due to active site blocking by adsorption of impurities and by-products. The large pore sulfonated catalyst also exhibited good catalytic performance in the selective synthesis of triacetin via acetylation of glycerol with acetic anhydride and out-performed the best zeolite H-Y with respect to reusability. It also demonstrated equally good activity in acetylation of cellulose to soluble cellulose acetates, with the possibility to control cellulose acetate yield and quality (degree of substitution, DS) by a simple adjustment of reaction time and acetic anhydride concentration. In contrast, the small pore and highly functionalized catalysts obtained by hydrothermal method and from protein rich waste (Jatropha de-oiled waste cake, DOWC), were active and selective in the esterification of glycerol with fatty acids to monoglycerides and saccharification of cellulosic materials, respectively. The operational stability and reusability of the catalyst was found to depend on the stability of –SO3H function (leaching) as well as active site blocking due to adsorption of impurities during the reaction. Thus, our results corroborate the potential of DOWC derived sulfated mesoporous active carbons as efficient integrated solid acid catalysts for valorization of biomass to platform chemicals, biofuel, bio-additive, surfactants and celluloseesters.

Isolado protéico de farelo de arroz: obtenção, propriedades funcionais e aplicação

O arroz é o segundo cereal mais produzido no mundo e para que ele seja consumido é necessário o processo de beneficiamento, onde é retirada a casca, e com o polimento, o farelo. O farelo, após a retirada do óleo, é utilizado para alimentação animal, mas como corresponde a 8% do grão, são necessárias novas alternativas para o uso do mesmo, uma vez que contém em torno de 17% de proteína. As proteínas do farelo de arroz são consideradas de alta qualidade, hipoalergênicas e anticancerígenas. Devido ao excesso de fibras presentes no farelo, este não é utilizado diretamente na alimentação humana, podendo ser usado como fonte para a obtenção de extratos, concentrados ou isolados. A obtenção do isolado protéico pode ser por via química, que consiste na extração alcalina ou ácida, seguida de precipitação no ponto isoelétrico ou via enzimática, com o uso de enzimas amilolíticas, hemicelulases e carboidrases para a separação das proteínas. O objetivo deste estudo foi obter um isolado protéico a partir de farelo de arroz visando a inclusão deste em produto de panificação. Foi obtido isolado protéico pelo método químico que foi analisado pelo rendimento protéico, pelas propriedades funcionais, perfil aminoacídico, eletroforese e características térmicas. O isolado foi adicionado em bolos em diferentes concentrações sendo avaliado pelas características tecnológicas e sensoriais. O isolado protéico do farelo de arroz (IPFA) que apresentou maior rendimento protéico foi o obtido pelo método químico, com o farelo de granulometria de 42 mesh e desengordurado. Em relação às propriedades funcionais, foi verificado que o IPFA possui maior solubilidade e capacidade de retenção de água em pH 11, alta capacidade emulsificante e alta capacidade de formação de espuma. No aminograma, constatou-se que os aminoácidos encontrados no IPFA atendem as necessidades de bebês e crianças. No perfil eletroforético, o IPFA apresentou 3 grupos de proteínas. Na análise térmica com DSC, o IPFA apresentou alta temperatura de desnaturação e baixo valor de entalpia. Na elaboração dos bolos, à medida que foi adicionado o IPFA, aumentou o teor protéico, o pH e o volume específico e diminuiu o colapso, a luminosidade e a firmeza dos bolos. Na análise sensorial, os bolos com IPFA não apresentaram diferenças estatísticas do bolo controle (sem IPFA). Estes resultados indicam a potencialidade do IPFA em produtos de panificação.

Mapeamento projetivo, associação de palavras e escala hedônica como instrumentos de avaliação da percepção de produtos de pescado por crianças da rede pública de ensino

Brazil is a country that is characterized by its low consumption of fish. With consumption records of 10.6 kg/ inhabitant/ year, it is lower than the recommended by the UN, that is 12 kg/ inhabitant/ year. The regular consumption of fish provides health gain for people and their introduction into the school feeding is an important strategy for the insertion of this food consumption habits in a population. In this context, the objective of this study was to understand the perception of fish with children from the public school system through the technical Projective Mapping (MP) and Association of Words (AP); and evaluate the acceptability of fish derivative in school meals. In the first instance with the intention to better understand the perception of children from different ages about the fish-based products, Projective Mapping techniques were applied through the use of food figures and word association. A total of 149 children from three public schools from Pato Branco, Paraná State, Brazil, took part in this study. Three groups of children aged 5-6, 7-8 and 9-10 years old were interviewed individually by six monitors experienced in applied sensory methods. Ten figures with healthy foods drawings (sushi, salad, fruit, fish, chicken), and less healthy foods (pizza, pudding, cake, hamburger, fries) were distributed to the children, who were asked to paste the figures in A3 sheet, so that the products they considered similar stayed near each other, and the ones considered very different stayed apart. After this, the children described the images and the image groups (Ultra Flash Profile). The results revealed that the MP technique was easily operated and understood by all the children and the use of images made its implementation easier. The results analysis also revealed different perceptions came from children from different ages and hedonic perceptions regarding the fish-based products had a greater weight in the percentage from older children. AP technique proved to be an important tool to understand the perception of fish by children, and strengthened the results previously obtained by the MP. In a second step it was evaluated the acceptance of fish burger (tilapia) in school meals. For this task, the school cooks were trained to prepare the hamburgers. For the evaluation of acceptance, the hedonic scale was used with 5 facial ratings (1 = disliked very much to 5 = liked a lot). Students from both genders, between 5 to 10 years old (n = 142) proved the burgers at lunchtime, representing the protein portion of the meal. The tilapia derivative products shown to be foods with important nutritional value and low calorie value. For the application of the multinomial logistic regression analysis there was no significant effect from the age and gender variation in the acceptance by children. However, statistical significance was determined in the interaction between these two variables. With 87 % acceptance rate there was potential for consumption of fish burgers in school meals.

Adieu New York, bonjour Paris ! : les enjeux esthétiques et culturels des appropriations du jazz dans le monde musical savant français (1900-1930)

Thèse réalisée en cotutelle avec l'Université Paris-Sorbonne et l'Université de Montréal. Composition du jury : M. Laurent Cugny (Université Paris-Sorbonne) ; M. Michel Duchesneau (Université de Montréal) ; M. Philippe Gumplowicz (Université d'Evry-Val d'Essonne) ; Mme Barbara Kelly (Keele University - Royal Northern College of Music) ; M. François de Médicis (Université de Montréal) ; M. Christopher Moore (Université d'Ottawa)

Modelagem e previsão da perda de injetividade em poços canhoneados

Waterflooding is a technique largely applied in the oil industry. The injected water displaces oil to the producer wells and avoid reservoir pressure decline. However, suspended particles in the injected water may cause plugging of pore throats causing formation damage (permeability reduction) and injectivity decline during waterflooding. When injectivity decline occurs it is necessary to increase the injection pressure in order to maintain water flow injection. Therefore, a reliable prediction of injectivity decline is essential in waterflooding projects. In this dissertation, a simulator based on the traditional porous medium filtration model (including deep bed filtration and external filter cake formation) was developed and applied to predict injectivity decline in perforated wells (this prediction was made from history data). Experimental modeling and injectivity decline in open-hole wells is also discussed. The injectivity of modeling showed good agreement with field data, which can be used to support plan stimulation injection wells

Análise da modelagem experimental da perda de injetividade

Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different