968 resultados para 291801 Fluidization and Fluid Mechanics


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Introduction: Obesity shows changes in pulmonary function and respiratory mechanics, however, little is known regarding the prevalence of worsening respiratory function when considering the increase in central or peripheral adiposity or general obesity. Objectives: To analyze the association between anthropometric adiposity and decreased lung function in obese. Materials and Methods: Patients eligible for this study obese individuals (IMC≥30kg/m2) in pre-bariatric surgery and referred for Treatment Clinic of Obesity and Related Diseases, located at the University Hospital Onofre Lopes (HUOL), from October 2005 and July 2014. The evaluation included clinical information and measurement of anthropometric measures (body mass index (BMI), body fat index (BFI) and waist circumference (WC) and neck (NC)) and spirometric. The prevalence and analysis by Poisson regression was performed considering the following outcome variables: forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and Maximum Voluntary Ventilation (MVV) and as predictor variables were considered: BMI, IAC, WC and NC and as control variables: age, gender, smoking history and comorbidities (diabetes mellitus, dyslipidemia and hypertension). Statistical analysis was performed using Statistical Package for Social Sciences software (SPSS - version 20.0). Results: We analyzed 384 individuals, 75% women, mean BMI: 46.6 (± 8.7) kg/m2, IAC: 49.26 (± 9.48)%, WC: 130.84 (± 16.23) cm and NC: 42.3 (± 4.6) cm. The higher prevalence of FVC and FEV1 <80% was observed in individuals with NC above 42 cm, followed those with a BMI above 45 kg/m2. Multivariate analysis using Poisson regression showed as risk factors associated with FVC <80%, the variables: NC above 42 cm (odds ratio (OR) 2.41) and BMI over 45Kg/m2 (OR 1.71 ). As for FEV1 <80% predicted, all predictor variables were associated, with the largest odds presented by the NC (3.40). MVVV was not associated with any studied varaible. Conclusion: Individuals with NC above 42 cm had higher prevalence of reduced lung function and the NC was the measure with the highest association with reduced lung function in obese.

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In the context of poetic productions of modernity and postmodernity (Hutcheon, 1999), this paper, from the concept of nomadism (Deleuze, 2012), together with the philosopher Derrida's notion of writing (2009), has the objective to study Harmada the novel (1993), written by artist Joao Gilberto Noll, the aspect of Nolliana nomadic scripture and boredom towards deconstruction of the Romanesque style. The narrative focus on introducing a transit fiction, promoted by nomadisms scripture of the wandering narrator who, in the work constitution, will the conduct of language, a plot that invades the body of the characters full of boredom and foreigners themselves, moving in fragmented and fluid spatiality of narrating. In this perspective, the research is limited with theoretical and methodological foundation in poststructuralist discussions in relation to considerations of literary aesthetics and concerning the thinkers-teóricos- critics: Derrida (2009), Deleuze (1995), Foucault (1996, 2001), Barthes (1977), Svendsen (2006). Against the background of critical understanding, the nomadic writing Harmada interlace in three stages: first, in the author's language; Second, the characters, the narrator-protagonist leading, unnamed, living overwhelming crises and painful existential ambiguity, placed through the artist's metaphor failed under the sign of "missing" while searching for other possible artistic ways of being in the world; and, finally, the nomadic reading instance as presentification effect (GUMBRECHT, 2010) for a reader experimentation. Finally, our work addresses the relationship between the nomadic scripture and the experience of boredom as a strategic power in the literature do Noll gear.

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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.

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Reading and writing are essential rights, which involve individual and social aspects; in addition, these skills are important when it comes to socio economic and political development, critical thinking and an active participation in society (UNESCO 2005). From a neurobiological standpoint, our brain is not prepared for reading, and this practice must be deliberately acquired via instructional guidance (DEHAENE 2009). However, reading disorders and deficits within executive functions, such as low working memory capacity, can make reading arduous. The aim of this study is to investigate the development of reading skills within 45 third grade students from public schools in the city of Natal – RN and its connection to working memory capacity, through information gathered from the Provinha Brasil, data generated from working memory tasks (Portuguese version of AWMA - Automated Working Memory Assessment) and fluid intelligence measures RAVEN. Based on this main objective, we attempted to answer the following research questions: (a) What are the correlations between working memory and reading scores?; (b) What characterizes the relationship between working memory capacity and the risk of reading disabilities amongst the participants in this study?; Following a quantitative research methodology, the Provinhas Brasil from 3rd grade students belonging to the six public schools members of Project ACERTA - Avaliação de Crianças em Risco de Transtornos de Aprendizagem (CAPES/OBEDUC)- were analyzed and compared to the scores from the working memory tests and the fluid intelligence ones. Results indicate that reading skills within children at risk of reading disabilities are directly linked to working memory capacity, especially with regards to the phonological component. It is also evident that the participants with less working memory capacity show more difficulties in the reading abilities that demand interpretation skills. Thus, we intend to contribute to the discussion regarding the diagnosis of reading disabilities and possible intervention strategies.

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Reading and writing are essential rights, which involve individual and social aspects; in addition, these skills are important when it comes to socio economic and political development, critical thinking and an active participation in society (UNESCO 2005). From a neurobiological standpoint, our brain is not prepared for reading, and this practice must be deliberately acquired via instructional guidance (DEHAENE 2009). However, reading disorders and deficits within executive functions, such as low working memory capacity, can make reading arduous. The aim of this study is to investigate the development of reading skills within 45 third grade students from public schools in the city of Natal – RN and its connection to working memory capacity, through information gathered from the Provinha Brasil, data generated from working memory tasks (Portuguese version of AWMA - Automated Working Memory Assessment) and fluid intelligence measures RAVEN. Based on this main objective, we attempted to answer the following research questions: (a) What are the correlations between working memory and reading scores?; (b) What characterizes the relationship between working memory capacity and the risk of reading disabilities amongst the participants in this study?; Following a quantitative research methodology, the Provinhas Brasil from 3rd grade students belonging to the six public schools members of Project ACERTA - Avaliação de Crianças em Risco de Transtornos de Aprendizagem (CAPES/OBEDUC)- were analyzed and compared to the scores from the working memory tests and the fluid intelligence ones. Results indicate that reading skills within children at risk of reading disabilities are directly linked to working memory capacity, especially with regards to the phonological component. It is also evident that the participants with less working memory capacity show more difficulties in the reading abilities that demand interpretation skills. Thus, we intend to contribute to the discussion regarding the diagnosis of reading disabilities and possible intervention strategies.

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The advance of drilling in deeper wells has required more thermostable materials. The use of synthetic fluids, which usually have a good chemical stability, faces the environmental constraints, besides it usually generate more discharge and require a costly disposal treatment of drilled cuttings, which are often not efficient and require mechanical components that hinder the operation. The adoption of aqueous fluids generally involves the use of chrome lignosulfonate, used as dispersant, which provides stability on rheological properties and fluid loss under high temperatures and pressures (HTHP). However, due to the environmental impact associated with the use of chrome compounds, the drilling industry needs alternatives that maintain the integrity of the property and ensure success of the operation in view of the strong influence of temperature on the viscosity of aqueous fluids and polymers used in these type fluids, often polysaccharides, passives of hydrolysis and biological degradation. Therefore, vinyl polymers were selected for this study because they have predominantly carbon chain and, in particular, polyvinylpyrrolidone (PVP) for resisting higher temperatures and partially hydrolyzed polyacrylamide (PHPA) and clay by increasing the system's viscosity. Moreover, the absence of acetal bonds reduces the sensitivity to attacks by bacteria. In order to develop an aqueous drilling fluid system for HTHP applications using PVP, HPAM and clay, as main constituents, fluid formulations were prepared and determined its rheological properties using rotary viscometer of the Fann, and volume filtrate obtained by filtration HTHP following the standard API 13B-2. The new fluid system using polyvinylpyrrolidone (PVP) with high molar weight had higher viscosities, gels and yield strength, due to the effect of flocculating clay. On the other hand, the low molecular weight PVP contributed to the formation of disperse systems with lower values in the rheological properties and fluid loss. Both systems are characterized by thermal stability gain up to around 120 ° C, keeping stable rheological parameters. The results were further corroborated through linear clay swelling tests.

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The advance of drilling in deeper wells has required more thermostable materials. The use of synthetic fluids, which usually have a good chemical stability, faces the environmental constraints, besides it usually generate more discharge and require a costly disposal treatment of drilled cuttings, which are often not efficient and require mechanical components that hinder the operation. The adoption of aqueous fluids generally involves the use of chrome lignosulfonate, used as dispersant, which provides stability on rheological properties and fluid loss under high temperatures and pressures (HTHP). However, due to the environmental impact associated with the use of chrome compounds, the drilling industry needs alternatives that maintain the integrity of the property and ensure success of the operation in view of the strong influence of temperature on the viscosity of aqueous fluids and polymers used in these type fluids, often polysaccharides, passives of hydrolysis and biological degradation. Therefore, vinyl polymers were selected for this study because they have predominantly carbon chain and, in particular, polyvinylpyrrolidone (PVP) for resisting higher temperatures and partially hydrolyzed polyacrylamide (PHPA) and clay by increasing the system's viscosity. Moreover, the absence of acetal bonds reduces the sensitivity to attacks by bacteria. In order to develop an aqueous drilling fluid system for HTHP applications using PVP, HPAM and clay, as main constituents, fluid formulations were prepared and determined its rheological properties using rotary viscometer of the Fann, and volume filtrate obtained by filtration HTHP following the standard API 13B-2. The new fluid system using polyvinylpyrrolidone (PVP) with high molar weight had higher viscosities, gels and yield strength, due to the effect of flocculating clay. On the other hand, the low molecular weight PVP contributed to the formation of disperse systems with lower values in the rheological properties and fluid loss. Both systems are characterized by thermal stability gain up to around 120 ° C, keeping stable rheological parameters. The results were further corroborated through linear clay swelling tests.

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Peer reviewed

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Twelve submarine mud volcanoes (MV) in the Kumano forearc basin within the Nankai Trough subduction zone were investigated for hydrocarbon origins and fluid dynamics. Gas hydrates diagnostic for methane concentrations exceeding solubilities were recovered from MVs 2, 4, 5, and 10. Molecular ratios (C1/C2<250) and stable carbon isotopic compositions (d13C-CH4 >-40 per mil V-PDB) indicate that hydrate-bound hydrocarbons (HCs) at MVs 2, 4, and 10 are derived from thermal cracking of organic matter. Considering thermal gradients at the nearby IODP Sites C0009 and C0002, the likely formation depth of such HCs ranges between 2300 and 4300 m below seafloor (mbsf). With respect to basin sediment thickness and the minimum distance to the top of the plate boundary thrust we propose that the majority of HCs fueling the MVs is derived from sediments of the Cretaceous to Tertiary Shimanto belt below Pliocene/Pleistocene to recent basin sediments. Considering their sizes and appearances hydrates are suggested to be relicts of higher MV activity in the past, although the sporadic presence of vesicomyid clams at MV 2 showed that fluid migration is sufficient to nourish chemosynthesis-based organisms in places. Distributions of dissolved methane at MVs 3, 4, 5, and 8 pointed at fluid supply through one or few MV conduits and effective methane oxidation in the immediate subsurface. The aged nature of the hydrates suggests that the major portion of methane immediately below the top of the methane-containing sediment interval is fueled by current hydrate dissolution rather than active migration from greater depth.

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Arginine vasopressin (AVP), a nine amino acid neuropeptide (CYFQNCPRG- NH2) fulfills a dual function: (i) in the periphery, AVP acts as a peptide hormone and (ii) in the CNS, AVP is a neuromodulatory peptide. AVP produces its effects through 3 AVP receptors (AVPRs). AVPR1a and AVPR1b are expressed in the CNS and periphery, whilst AVPR2 is not found centrally but instead solely expressed in the kidneys. Recent evidence revealed a high density of AVP-binding sites in the juxtacapsular nucleus of the bed nucleus of the stria terminalis (jxBNST). While in other regions of the brain, AVP acts at AVPRs to regulate an array of biological processes, including male-typical social behaviours, social memory, stress adaptation, fear, anxiety, and fluid homeostasis, its role in the jxBNST remains elusive. Furthermore, the neurophysiological properties of AVP in the jxBNST are unknown so this study aimed to examine how AVP modulates synaptic transmission in the rat jxBNST. The BNST being one of the most notable sexually dimorphic brain regions and AVPR expression being influenced by gonadal steroids, we investigated the putative influence of sex on the modulatory effects of AVP in the jxBNST. Finally, due to AVP being released at a substantially higher concentration following periods of water deprivation, we examined changes in AVPs modulatory role following water deprivation. Male and female Long Evans rats were euthanized and brain slice whole-cell voltage-clamp electrophysiology was done in the jxBNST to measure the effects of AVP on synaptic transmission of GABA synapses. Exogenous application of AVP produced three responses; either postsynaptic long-term potentiation (LTP) of GABAA-inhibitory postsynaptic currents (IPSC), postsynaptic long-term depression (LTD) of GABAA-IPSC, or no change in GABAA-IPSC amplitudes. Interestingly, the proportion of neurons responding in each of these ways did not differ between sexes and within females was not estrous cycle-dependent. Finally, although not statistically significant, 24-hour water deprivation abolished GABAA-LTD, an effect that was not a consequence of social isolation. Taken together, our data show that AVP modulates GABAA synaptic transmission in the jxBNST in fluid homeostasis- but not sex-dependent manner.

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Computer games have now been around for over three decades and the term serious games has been attributed to the use of computer games that are thought to have educational value. Game-based learning (GBL) has been applied in a number of different fields such as medicine, languages and software engineering. Furthermore, serious games can be a very effective as an instructional tool and can assist learning by providing an alternative way of presenting instructions and content on a supplementary level, and can promote student motivation and interest in subject matter resulting in enhanced learning effectiveness. REVLAW (Real and Virtual Reality Law) is a research project that the departments of Law and Computer Science of Westminster University have proposed as a new framework in which law students can explore a real case scenario using Virtual Reality (VR) technology to discover important pieces of evidence from a real-given scenario and make up their mind over the crime case if this is a murder or not. REVLAW integrates the immersion into VR as the perception of being physically present in a non-physical world. The paper presents the prototype framework and the mechanics used to make students focus on the crime case and make the best use of this immersive learning approach.