999 resultados para Operações unitárias - Perda de carga
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Death due to childhood cancer reflects an early outcome of life, which can cause a strong repercussion in the mother s existence - figure to whom the greatest part of responsibilities during the child s illness is commonly allocated. The aim of this study is to understand the experience of mothers who have lost a kid as a consequence of childhood cancer, approaching the personal senses of this fact. Following a qualitative research design, with an exploratory and comprehensive approach, the study used the narrative method, which was obtained from a semi-structured interview, as the data generation procedure. The research counted on the participation of three adult mothers who had lost their kids because of childhood cancer, after - at least - a six-month period of oncologic treatment. The proposal of analysis follows the parameters of the phenomenological method and the data are based on Martin Heidegger s existential analytic. The results were structured into three thematic axes: previous History, child illness and its repercussions; The network of support and care; Loss and after loss: facing and signifying. It was possible to comprehend that the emergence of cancer in childhood promotes, since the diagnosis, a disruption of everyday meanings, accentuating the fragile condition of human life. In this specific circumstance of childhood illness, all the participants restricted their possibilities of being-in-the-world, dedicating exclusively to the practice of maternity. Concerning their relationship with their children in treatment, the narratives unveiled, in a convergent manner, the existence of care in a substitutive mode. In the network of support - primarily constituted by family, the health team and the support institutions - the relations were marked by proximity and detachment movements. With the child s death, mothers began to live a way of being-with the absent child , ensuring the continuity of the relationship with the dead infant. From the results exposed above, we can understand the motherly mourn as a singular experience in constant resignification, in which the subjective time overlaps the cronological time. The increment of anguish, resulting from the mother s confrontation to the question of finitude, mobilizes a process of change in their way of being-in-the-world, promoting an openness to new possibilities in their lives. Singular attention to the mother, during the process of illness and child loss, turns out to be fundamental
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The knowledge of the rheological behavior of microemulsionated systems (SME) is of fundamental importance due to the diversity of industrial applications of these systems. This dissertation presents the rheological behavior of the microemulsionated system formed by RNX 95/alcohol isopropyl/p-toulen sodium sulfonate/kerosene/distilled water with the addition of polyacrylamide polymer. It was chosen three polymers of the polyacrylamide type, which differ in molar weight and charge density. It was studied the addition of these polymers in relatively small concentration 0,1% in mass and maximum concentration of 2,0%. It was made analysis of flow to determine the appearing viscosities of the SME and rheological parameters applying Bingham, Ostwald de Waale and Herschell-Buckley models. The behavior into saline environment of this system was studied for a solution of KCl 2,0%, replacing the distilled water. It was determined the behavior of microemulsions in relation with the temperature through curves of flow in temperatures of 25 to 60ºC in variations of 5ºC. After the analysis of the results the microemulsion without the addition of polymer presented a slight increase in its viscosity, but it does not mischaracterize it as a Newtonian fluid. However the additive systems when analyzed with low concentration of polymer adjusted well to the applied models, with a very close behavior of microemulsion. The higher concentration of the polymer gave the systems a behavior of plastic fluid. The results of the temperature variation point to an increase of viscosity in the systems that can be related to structural changes in the micelles formed in the own microemulsion without the addition of polymer
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Chitosan is a biopolymer derived from the shells of crustaceans, biodegradable, inexpensive and renewable with important physical and chemical properties. Moreover, the different modifications possible in its chemical structure generate new properties, making it an attractive polysaccharide owing to its range of potential applications. Polymers have been used in oil production operations. However, growing concern over environmental constraints has prompted oil industry to search for environmentally sustainable materials. As such, this study sought to obtain chitosan derivatives grafted with hydrophilic (poly(ethylene glycol), mPEG) and/or hydrophobic groups (n-dodecyl) via a simple (one-pot) method and evaluate their physicochemical properties as a function of varying pH using rheology, small-angle Xray scattering (SAXS), dynamic light scattering (DLS) and zeta potential. The chitosan derivatives were prepared using reductive alkylation under mild reaction conditions and the chemical structure of the polymers was characterized by nuclear magnetic resonance (1H NMR) and CHN elemental analysis. Considering a constant mPEG/Chitosan molar ratio on modification of chitosan, the solubility of the polymer across a wide pH range (acidic, neutral and basic) could only be improved when some of the amino groups were submitted to reacetylation using the one-pot method. Under these conditions, solubility is maintained even with the simultaneous insertion of n-dodecyl. On the other hand, the solubility of derivatives obtained only through mPEG incorporation using the traditional methodology, or with the ndodecyl group, was similar to that of its precursor. The hydrophilic group promoted decreased viscosity of the polymer solutions at 10 g/L in acid medium. However, at basic pH, both viscosity and thermal stability increased, as well as exhibited a pronounced pseudoplastic behavior, suggesting strong intermolecular associations in the alkaline medium. The SAXS results showed a polyelectrolyte behavior with the decrease in pH for the polymer systems. DLS analyses revealed that although the dilute polymer solutions at 1 g/L and pH 3 exhibited a high density of protonated amino groups along the polymer chain, the high degree of charge contributed significantly to aggregation, promoting increased particle size with the decrease in pH. Furthermore, the hydrophobic group also contributed to increasing the size of aggregates in solution at pH 3, whereas the hydrophilic group helped reduce their size across the entire pH range. Nevertheless, the nature of aggregation was dependent on the pH of the medium. Zeta potential results indicated that its values do not depend solely on the surface charge of the particle, but are also dependent on the net charge of the medium. In this study, water soluble associative polymers exhibit properties that can be of great interest in the petroleum industry
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The role of carboxymethylcellulose (CMC) in association to calcium carbonate particles (CaCO3) in most water-based drilling fluids is to reduce the fluid loss to the surrounding formation. Another essential function is to provide rheological properties capable of maintaining in suspension the cuttings during drilling operation. Therefore, it is absolutely essential to correlate the polymer chemical structure (degree of substitution, molecular weight and distribution of substituent) with the physical-chemical properties of CaCO3, in order to obtain the better result at lower cost. Another important aspect refers to the clay hydration inhibitive properties of carboxymethylcellulose (CMC) in drilling fluids systems. The clay swelling promotes an undesirable damage that reduces the formation permeability and causes serious problems during the drilling operation. In this context, this thesis consists of two main parts. The first part refers to understanding of interactions CMC-CaCO3, as well as the corresponding effects on the fluid properties. The second part is related to understanding of mechanisms by which CMC adsorption occurs onto the clay surface, where, certainly, polymer chemical structure, ionic strength, molecular weight and its solvency in the medium are responsible to affect intrinsically the clay layers stabilization. Three samples of carboximetilcellulose with different molecular weight and degree of substitution (CMC A (9 x 104 gmol DS 0.7), CMC B (2.5 x 105 gmol DS 0.7) e CMC C (2.5 x 105 gmol DS 1.2)) and three samples of calcite with different average particle diameter and particle size distribution were used. The increase of CMC degree of substitution contributed to increase of polymer charge density and therefore, reduced its stability in brine, promoting the aggregation with the increase of filtrate volume. On the other hand, the increase of molecular weight promoted an increase of rheological properties with reduction of filtrate volume. Both effects are directly associated to hydrodynamic volume of polymer molecule in the medium. The granulometry of CaCO3 particles influenced not only the rheological properties, due to adsorption of polymers, but also the filtration properties. It was observed that the lower filtrate volume was obtained by using a CaCO3 sample of a low average size particle with wide dispersion in size. With regards to inhibition of clay swelling, the CMC performance was compared to other products often used (sodium chloride (NaCl), potassium chloride (KCl) and quaternary amine-based commercial inhibitor). The low molecular weight CMC (9 x 104 g/mol) showed slightly lower swelling degree compared to the high molecular weight (2.5 x 105 g/mol) along to 180 minutes. In parallel, it can be visualized by Scanning Electron Microscopy (SEM) that the high molecular weight CMC (2.5 x 105 g/mol e DS 0.7) promoted a reduction in pores formation and size of clay compared to low molecular weight CMC (9.0 x 104 g/mol e DS 0.7), after 1000 minutes in aqueous medium. This behavior was attributed to dynamic of interactions between clay and the hydrodynamic volume of CMC along the time, which is result of strong contribution of electrostatic interactions and hydrogen bounds between carboxylate groups and hydroxyls located along the polymer backbone and ionic and polar groups of clay surface. CMC adsorbs on clay surface promoting the skin formation , which is responsible to minimize the migration of water to porous medium. With the increase of degree of substitution, it was observed an increase of pores onto clay, suggesting that the higher charge density on polymer is responsible to decrease its flexibility and adsorption onto clay surface. The joint evaluation of these results indicate that high molecular weight is responsible to better results on control of rheological, filtration and clay swelling properties, however, the contrary effect is observed with the increase of degree of substitution. On its turn, the calcite presents better results of rheological and filtration properties with the decrease of average viii particle diameter and increase of particle size distribution. According to all properties evaluated, it has been obvious the interaction of CMC with the minerals (CaCO3 and clay) in the aqueous medium
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Most cochlear implant (CI) users, who suffer from post lingual hearing loss, are able to perceive sounds and comprehend speech after the implant. The prediction of maximal benefit over time, with the use of CI, can be useful for counseling patients about their expectations in using the new device. The measurement of satisfaction should be of primary interest in medical intervention, as the results may be used for intervention feedback. The purpose of this study is to analyze auditory performance of CI over time, as well as to evaluate users‟ satisfaction. Therefore two types of study designs were employed: a) retrospective cohort study with the analysis of medical records from 59 subjects about auditory performance before and after surgery. Results were submitted to the Kaplan -Meier estimator of cumulative probability and compared to prognostic factors of auditory performance using the logrank test. b) A sectional study design was conducted to evaluate the satisfaction of 51 subjects. The instrument consists of two specific questionnaires: Satisfaction with Amplification in Daily Life SADL and International Outcome Inventory Cochlear Implant IOI- CI. Results show statistical significant differences (p<0,001) in auditory performance before and after CI. The majority obtained satisfactory results of CI use during the first six months. Logrank tests does not indicate significant correlation between the analyzed covariates and the time in which adequate speech perception occurs. SADL e IOI-CI questionnaires indicate that most of the CI users are satisfied with their devices. The SADL detected a 27, 5% insatisfaction amongst CI users in relation to services and costs involved with the CI. The results of the IOI show 4% of insatisfaction with the use of CI and the social environment. In conclusion CI is capable to rehabilitate social auditory function in a short period of time and CI users demonstrate satisfaction with auditory, social and psychological gain offered through CI device
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It bet on the next generation of computers as architecture with multiple processors and/or multicore processors. In this sense there are challenges related to features interconnection, operating frequency, the area on chip, power dissipation, performance and programmability. The mechanism of interconnection and communication it was considered ideal for this type of architecture are the networks-on-chip, due its scalability, reusability and intrinsic parallelism. The networks-on-chip communication is accomplished by transmitting packets that carry data and instructions that represent requests and responses between the processing elements interconnected by the network. The transmission of packets is accomplished as in a pipeline between the routers in the network, from source to destination of the communication, even allowing simultaneous communications between pairs of different sources and destinations. From this fact, it is proposed to transform the entire infrastructure communication of network-on-chip, using the routing mechanisms, arbitration and storage, in a parallel processing system for high performance. In this proposal, the packages are formed by instructions and data that represent the applications, which are executed on routers as well as they are transmitted, using the pipeline and parallel communication transmissions. In contrast, traditional processors are not used, but only single cores that control the access to memory. An implementation of this idea is called IPNoSys (Integrated Processing NoC System), which has an own programming model and a routing algorithm that guarantees the execution of all instructions in the packets, preventing situations of deadlock, livelock and starvation. This architecture provides mechanisms for input and output, interruption and operating system support. As proof of concept was developed a programming environment and a simulator for this architecture in SystemC, which allows configuration of various parameters and to obtain several results to evaluate it
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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A aplicação de isolantes térmicos em sistemas construtivos promove vantagens com vistas ao conforto térmico de ambientes. E com isso, o aumento da produtividade em locais de trabalho, a sensação de bem-estar e a diminuição dos custos com climatização. A demanda por conforto ambiental, no âmbito da isolação térmica, somada ao advento de novas leis que regulam os requisitos mínimos de conforto, as exigências dos consumidores pela adoção de métodos de produção mais “limpos”, a fiscalização quanto à destinação de resíduos industriais, além da inserção de produtos no mercado com apelos ambientais, incentivaram o desenvolvimento da presente pesquisa. O presente trabalho trata da aplicação do poliuretano, visando comparar o desempenho térmico do derivado de origem vegetal (óleo de mamona) com adição de resíduo plástico termofixo em diferentes proporções (5%, 10%, 15% e 20%), com o poliuretano petrolífero, a lã de vidro e a lã de rocha através da análise de suas propriedades térmicas (condutividade térmica – k, difusividade térmica – e capacidade calorífica – Cp). . Após a realização dos ensaios, os compósitos estudados foram moídos e reutilizados como carga para novos compósitos. Com base nos resultados dos ensaios de propriedades térmicas, constatou-se que o material desenvolvido conduz menos calor que o poliuretano de petróleo, a lã de vidro e a lã de rocha, além de oferecer alta inércia térmica, bom desempenho térmico e baixo custo. Assim como foi comprovada a possibilidade de fabricação de novos compósitos para fins de isolamento, reutilizando os compósitos testados
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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The great interest observed in wireless communication systems has required the development of new configurations of microstrip antennas, because they are easily built and integrated to other microwave circuit components, which is suitable for the construction and development of planar antenna arrays and microwave integrated circuits. This work presents a new configuration of tapered microstrip antenna, which is obtained by impressing U-slots on the conducting patch combined with a transmission line matching circuit that uses an inset length. It is shown that the use of U-slots in the microstrip antenna conducting patch excites new resonating modes, that gives a multiband characteristic for the slotted microstrip antenna, that is suitable for applications in communication systems that operates several frequencies simultaneously. Up to this date, the works reported in the literature deals with the use of Uslotted microstrip rectangular antennas fed by a coaxial probe. The properties of a linear array of microstrip patch tapered antennas are also investigated. The main parameters of the U slotted tapered microstrip antennas are investigated for different sizes and locations of the slots impressed on the conducting patch. The analysis of the proposed antenna is performed by using the resonant cavity and equivalent transmission line methods, in combination with a parametric study, that is conducted by the use of the Ansoft Designer, a commercial computer aided microwave software well known by its accuracy and efficiency. The mentioned methods are used to evaluate the effect in the antennas parameters, like resonant frequency and return loss, produced by variations of the antenna structural parameters, accomplished separately or simultaneously. An experimental investigation is also developed, that consists of the design, construction and measurement of several U slotted microstrip antenna prototypes. Finally, theoretical and simulated results are presented that are in agreement with the measured ones. These results are related to the resonating modes identification and to the determination of the main characteristics of the investigated antennas, such as resonant frequency, return loss, and radiation pattern
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O objetivo do estudo foi comparar a influência da idade na massa muscular e na força muscular, de membros superiores e inferiores, em mulheres acima de 40 anos. Foram estudadas 52 voluntárias, divididas em 3 grupos etários: 40-49 anos(G40, n=16), 50-59 anos(G50, n=18) e 60-70 anos(G60, n=18). Avaliaram-se: massa muscular (MM) por impedância bioelétrica e força muscular-1RM (FM). Para estatística, utilizaram-se análise variância-one-way, teste de Duncan e correlação de Pearson. Observou-se diferença significativa (p<0,05) entre 10,1% na MM entre G40 e G50 e 7,5% entre G50 e G60, totalizando 16,8% nas duas décadas (G40/G60). A FM de membros inferiores foi 16,4% menor entre G40 e G50 e 12,5% entre G50 e G60, perfazendo 25,3% nas duas décadas (p<0,05). Nos membros superiores, não houve diferença significativa da força, entre G40 e G50 (3,3% supino reto e 2,5% rosca direta) e entre G50 e G60 (17,5% e 9,6%), totalizando, nas duas décadas, 20,2% e 12,2%, respectivamente. A Soma das FMs foi corrigida pela MM (FMs/MM), não apresentando diferenças estatísticas entre os grupos. Correlacionando-se MM e FM, houve maior analogia nos membros inferiores (r=0,57), quando comparados aos membros superiores (r=0,42 e r=41, respectivamente). Concluíu-se que as mulheres apresentaram menores valores de MM e de FM nos membros inferiores logo na quinta década de vida. A FMs/MM parece não se alterar em mulheres entre 40 e 60 anos, quando comparadas por grupos etários. A MM reduzida parece ser fator importante para os menores valores de FM observados em mulheres entre 40 e 60 anos.
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Há evidências de que o ultrassom (US) de baixa intensidade pode acelerar a regeneração óssea. Este trabalho objetivou verificar a ação do US no defeito ósseo, criado experimentalmente em tíbias de ratos sob ausência de carga. Vinte Rattus novergicus albinus, Wistar adultos, divididos em: G1 (n=10), grupo experimental de 15 dias sem suspensão, e G2 (n=10), grupo experimental de 15 dias suspenso pela cauda, foram submetidos à osteotomia em ambas as tíbias e à aplicação do US, frequência de 1,5 MHz, ciclo de trabalho 1:4, 30 mW/cm², nas tíbias direitas por 12 sessões de 20 minutos. Após o sacrifício, as tíbias foram submetidas à análise da Densidade Mineral Óssea (DMO). Os resultados demonstraram DMO de 0,139±0,018 g/cm² para tíbia tratada; 0,131±0,009 g/cm² para tíbia controle no G1; e no G2 registrou-se 0,120±0,009 g/cm² para tíbia tratada e 0,106±0,017 g/cm² para tíbia controle. Houve diferença significante entre os grupos nos quais o G2 apresentou menor DMO, o que demonstra que a suspensão prejudica a manutenção das propriedades ósseas, e entre as tíbias tratadas e controles do G2, demonstrando que o US acelerou o processo de reparo, concluindo que a impossibilidade do estímulo mecânico causada pela não deambulação em um processo de reparo ósseo pode ser minimizada pela ação do US. No G1, a aplicação do US não teve influência significante no aumento da DMO, talvez pelo fato dos animais já terem estímulo mecânico suficiente à formação óssea.
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Foi conduzido um experimento a fim de estudar, comparativamente, o efeito da uréia coberta com enxofre (SCU) e uréia não coberta sobre a perda de nitrogênio (N-NH+4 + N-NO-3) por lixiviaçao em um Latossol Roxo que ocorre sob vegetação de cerrado no Município de Botucatu, SP-Brasil, bem como a influência de doses destes fertilizantes e do pH do solo. Verificou-se que SCU reduziu as perdas de nitrogênio, através do processo de lixiação, apresentando lenta liberação do elemento. O efeito das doses refletiu-se nas perdas por lixiviaçao com uma maior perda para a dose mais elevada (120 kg n/ ha). Houve influência do pH ocorrendo maiores perdas de N para o valor mais elenado, ou seja, no pH 6,5, para ambos os tipos de uréia, verificando-se também que o pH não influiu na liberação do N retido no grânulo de SCU.