866 resultados para the arousal theory


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This paper introduces a screw theory based method termed constraint and position identification (CPI) approach to synthesize decoupled spatial translational compliant parallel manipulators (XYZ CPMs) with consideration of actuation isolation. The proposed approach is based on a systematic arrangement of rigid stages and compliant modules in a three-legged XYZ CPM system using the constraint spaces and the position spaces of the compliant modules. The constraint spaces and the position spaces are firstly derived based on the screw theory instead of using the rigid-body mechanism design experience. Additionally, the constraint spaces are classified into different constraint combinations, with typical position spaces depicted via geometric entities. Furthermore, the systematic synthesis process based on the constraint combinations and the geometric entities is demonstrated via several examples. Finally, several novel decoupled XYZ CPMs with monolithic configurations are created and verified by finite elements analysis. The present CPI approach enables experts and beginners to synthesize a variety of decoupled XYZ CPMs with consideration of actuation isolation by selecting an appropriate constraint and an optimal position for each of the compliant modules according to a specific application.

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The Overactive Bladder (OAB) and Bladder Pain Syndrome (BPS) are debilitating disorders for which the pathophysiological mechanisms are poorly understood. Injury or dysfunction of the protective urothelial barrier layer, specifically the proteoglycan composition and number, has been proposed as the primary pathological characteristic of BPS. For OAB, the myogenic theory with dysfunction of the muscarinic receptors is the most reiterated hypothesis. For both over activity of the inflammatory response has been posited to play a major role in these diseases. We hypothesise that BPS and OAB are peripheral sensory disorders, with an increase in inflammatory mediators, such as cytokines and chemokines, which are capable of activating, either directly or indirectly, sensory nerve activity causing the disease. The aim of the PhD is to identify potential new therapeutic targets for the treatment of BPS and OAB. We used medium throughput quantitative gene expression analysis of 96 inflammation associated mediators to measure gene expression levels in BPS and OAB bladder biopsies and compared them to control samples. Then we created a novel animal model of disease by specific proteoglycan deglycosylation of the bladder mucosal barrier, using the bacterial enzymes Chondroitinase ABC and Heparanase III. These enzymes specifically remove the glycosaminoglycan side chains from the urothelial proteoglycan molecules. We tested role of the identified mediators in this animal model. In addition, in order to determine on which patients peripheral treatment strategies may work, we assessed the effect of local anaesthetics on patients with bladder pain. Gene expression analysis did not reveal a difference in inflammatory genes in the OAB versus control biopsies. However, several genes were upregulated in BPS versus control samples, from which two genes, FGF7 and CLL21 were correlated with patient clinical phenotypes for ICS/PI symptom and problem indices respectively. In order to determine which patients are likely to respond to treatment, we sought to characterise the bladder pain in BPS patients. Using urodynamics and local anaesthetics, we differentiated patients with peripherally mediated pain and patients with central sensitisation of their pain. Finally to determine the role of these mediators in bladder pain, we created an animal model of disease, which specifically replicates the human pathology: namely disruption in the barrier proteoglycan molecules. CCL21 led to an increase in painrelated behaviour, while FGF7 attenuated this behaviour, as measured by cystometry, spinal c-fos expression and mechanical withdrawal threshold examination. In conclusion, we have identified CCL21 and FGF7 as potential targets for the treatment of BPS. Manipulation of these ligands or their receptors may prove to be valuable previously unexploited targets for the treatment of BPS.

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This thesis explores the new art historical turn in contemporary art through close engagement with three British artworks. These are Tacita Dean’s, Section Cinema (Homage to Marcel Broodthaers), 2002, Jeremy Millar’s, The Man Who Looked Back, 2010, and Lucy Skaer’s, Leonora, 2006. Each of these artworks combines an art historical agenda with a celebration of the specificities of analogue film and photography in the context of our digital age. This thesis combines twentieth century photographic theory from Roland Barthes, André Bazin and Walter Benjamin, among others, with the psychoanalytic theory of Jacques Lacan in order to argue that the indexical qualities of analogue film and photography place the medium in close proximity to the Lacanian Real. In its obsolescence the analogue’s language of both touch and loss is heightened. Each chapter of this thesis explores a different aspect of the Real in relation to specific attributes of the analogue, such as its propensity for archiving cultural traumas, its receptiveness to chance, and its proximity to death.

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This research, conducted in 2006-2008, examines the ways in which various groups involved with the marine resources of Seward, Alaska construct attitudes towards the environment. Participant observation and semi-structured interviews are used to assess how commercial halibut fishers, tour boat operators, local residents and government officials understand the marine environment based on their previous experiences. This study also explores how ideologies relate to the current practices of each group. Two theories orient the analyses: The first, cultural modeling provided a theoretical and methodological framework for pursuing a more comprehensive analysis of resource management. The second, Theory of Reasoned Action (Ajzen and Fishbein 1980), guided the analysis of the ways in which each participant’s ideology towards the marine environment relates to their practice. Aside from contributing to a better understanding of a coastal community’s ideologies and practices, this dissertation sought to better understand the role of ecological ideologies and behaviors in fisheries management. The research illustrates certain domains where ideologies and practices concerning Pacific halibut and the marine environment differ among commercial fishers, government, and management officials, tour boat operators and residents of Seward, AK. These differences offer insights into how future collaborative efforts between government officials, managers and local marine resource users might better incorporate local ideology into management, and provide ecological information to local marine resource users in culturally appropriate ways.

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Despite its importance in the global climate system, age-calibrated marine geologic records reflecting the evolution of glacial cycles through the Pleistocene are largely absent from the central Arctic Ocean. This is especially true for sediments older than 200 ka. Three sites cored during the Integrated Ocean Drilling Program's Expedition 302, the Arctic Coring Expedition (ACEX), provide a 27 m continuous sedimentary section from the Lomonosov Ridge in the central Arctic Ocean. Two key biostratigraphic datums and constraints from the magnetic inclination data are used to anchor the chronology of these sediments back to the base of the Cobb Mountain subchron (1215 ka). Beyond 1215 ka, two best fitting geomagnetic models are used to investigate the nature of cyclostratigraphic change. Within this chronology we show that bulk and mineral magnetic properties of the sediments vary on predicted Milankovitch frequencies. These cyclic variations record ''glacial'' and ''interglacial'' modes of sediment deposition on the Lomonosov Ridge as evident in studies of ice-rafted debris and stable isotopic and faunal assemblages for the last two glacial cycles and were used to tune the age model. Potential errors, which largely arise from uncertainties in the nature of downhole paleomagnetic variability, and the choice of a tuning target are handled by defining an error envelope that is based on the best fitting cyclostratigraphic and geomagnetic solutions.

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Although various models have been proposed to explain the origin of manganese nodules (see Goldberg and Arrhenius), two major hypotheses have received extensive attention. One concept suggests that manganese nodules form as the result of interaction between submarine volcanic products and sea water. The common association of manganese nodules with volcanic materials constitutes the main evidence for this theory. The second theory involves a direct inorganic precipitation of manganese from sea water. Goldberg and Arrhenius view this process as the oxidation of divalent manganese to tetravalent manganese by oxygen under the catalytic action of particulate iron hydroxides. Manganese accumulation by the Goldberg and Arrhenius theory would be a relatively slow and comparatively steady process, whereas Bonatti and Nayudu believe manganese nodule formation takes place subsequent to the eruption of submarine volcanoes by the acidic leaching of lava.

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This paper deals with the conceptions of the different school actors about the meaning and the implications of mediation in their schools, drawing on data from a qualitative approach carried out as part of a wider project to map mediation perspectives and practices in Catalonia. The authors analyze the scope of the situations regarded as suitable or unsuitable for the introduction of restorative practices, as well as the resistance to change in the practice of conflict resolutions and in the democratization of school culture.

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This article propose to analyse the theoretical sources which constitutes the political culture of the Brazilian authoritarianism in the 20th century, principally in the work of Francisco Campos and his connection with the “integralismo” and its catholic conservatism ways. The hypothesis is that the mentioned connection which had inspired the ideological political culture which make possible all the sources and historical conditions to the implementation of the Brazilian dictatorship in the year 1964. This article has analysed the facist inspiration of the Campos´s theory and how it has happened, his hidden dialogue with Carl Schmitt, settling issuing lines of understanding on contemporary authoritarianism whose spreading still proceed, but now standing under new figures, discourses, rhetorics, symbologies and enemies.

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Este artículo hace una reconstrucción crítica de la visión de Keynes sobre la relación entre gasto público, tipo de interés, salarios y desempleo, tal y como se formula en su Tratado sobre el Dinero. El trabajo defiende que el enfoque de Keynes lleva a propuestas de política económica que enfatizan la necesidad de intervención estatal directa en la provisión de bienes y servicios. Esta conclusión se deriva de una interpretación circuitista de su obra.

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The market for luxury brands has outpaced other consumption categories through its growth, and has been found in continuous development. As there is an increasing amount of luxury categories, the consumption of luxury fashion brands account for the largest proportion of luxury profits, and the marketing costs for such brands has shown to surpass those of other fashion categories. Consumer researchers have throughout decades emphasized how individuals participate in consumption behavior to form their self-concept in relation to brands. However, previous research has disregarded the multidimensional perspective regarding the theory of self-concept when examining the consumption of brands. Hence, the current research paper aims to strengthen the existing self-concept theory by exploring the role in which luxury fashion brands have by focusing on how the consumption of such brands relate, and contribute, to the consumer’s self-concept. By applying a qualitative method to investigate such purpose, and involving the existing theory of self-concept, brand image, and brand personality, it appeared that luxury fashion brands has a function to operate as a confidence booster for young consumers’ perception of their self-concept. In terms of the theoretical contribution of this paper, this research further illustrates how the theoretical explanation of brand image and brand personality relates to two different dimensions of the consumer’s self-concept. The consumption of luxury fashion brands has shown a significant role in individuals’ consumption behavior by emphasizing a striving, and motivating, part in the self-concept of young consumers.

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The use of the Design by Analysis concept is a trend in modern pressure vessel and piping calculations. DBA flexibility allow us to deal with unexpected configurations detected at in-service inspections. It is also important, in life extension calculations, when deviations of the original standard hypotesis adopted initially in Design by Formula, can happen. To apply the DBA to structures under variable mechanic and thermal loads, it is necessary that, alternate plasticity and incremental collapse (with instantaneous plastic collapse as a particular case), be precluded. These are two basic failure modes considered by ASME or European Standards in DBA. The shakedown theory is the tool available to achieve this goal. In order to apply it, is necessary only the range of the variable loads and the material properties. Precise, robust and efficient algorithms to solve the very large nonlinear optimization problems generated in numerical applications of the shakedown theory is a recent achievement. Zouain and co-workers developed one of these algorithms for elastic ideally-plastic materials. But, it is necessary to consider more realistic material properties in real practical applications. This paper shows an enhancement of this algorithm to dealing with limited kinematic hardening, a typical property of the usual steels. This is done using internal thermodynamic variables. A discrete algorithm is obtained using a plane stress, mixed finite element, with internal variable. An example, a beam encased in an end, under constant axial force and variable moment is presented to show the importance of considering the limited kinematic hardening in a shakedown analysis.

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Thesis (Master's)--University of Washington, 2016-08

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Thesis (Master's)--University of Washington, 2016-06

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The industrial production of aluminium is an electrolysis process where two superposed horizontal liquid layers are subjected to a mainly vertical electric current supplied by carbon electrodes. The lower layer consists of molten aluminium and lies on the cathode. The upper layer is the electrolyte and is covered by the anode. The interface between the two layers is often perturbed, leading to oscillations, or waves, similar to the waves on the surface of seas or lakes. The presence of electric currents and the resulting magnetic field are responsible for electromagnetic (Lorentz) forces within the fluid, which can amplify these oscillations and have an adverse influence on the process. The electrolytic bath vertical to horizontal aspect ratio is such, that it is advantageous to use the shallow water equations to model the interface motion. These are the depth-averaging the Navier-Stokes equations so that nonlinear and dispersion terms may be taken into account. Although these terms are essential to the prediction of wave dynamics, they are neglected in most of the literature on interface instabilities in aluminium reduction cells where only the linear theory is usually considered. The unknown variables are the two horizontal components of the fluid velocity, the height of the interface and the electric potential. In this application, a finite volume resolution of the double-layer shallow water equations including the electromagnetic sources has been developed, for incorporation into a generic three-dimensional computational fluid dynamics code that also deals with heat transfer within the cell.

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This dissertation demonstrates an explanation of damage and reliability of critical components and structures within the second law of thermodynamics. The approach relies on the fundamentals of irreversible thermodynamics, specifically the concept of entropy generation due to materials degradation as an index of damage. All failure mechanisms that cause degradation, damage accumulation and ultimate failure share a common feature, namely energy dissipation. Energy dissipation, as a fundamental measure for irreversibility in a thermodynamic treatment of non-equilibrium processes, leads to and can be expressed in terms of entropy generation. The dissertation proposes a theory of damage by relating entropy generation to energy dissipation via generalized thermodynamic forces and thermodynamic fluxes that formally describes the resulting damage. Following the proposed theory of entropic damage, an approach to reliability and integrity characterization based on thermodynamic entropy is discussed. It is shown that the variability in the amount of the thermodynamic-based damage and uncertainties about the parameters of a distribution model describing the variability, leads to a more consistent and broader definition of the well know time-to-failure distribution in reliability engineering. As such it has been shown that the reliability function can be derived from the thermodynamic laws rather than estimated from the observed failure histories. Furthermore, using the superior advantages of the use of entropy generation and accumulation as a damage index in comparison to common observable markers of damage such as crack size, a method is proposed to explain the prognostics and health management (PHM) in terms of the entropic damage. The proposed entropic-based damage theory to reliability and integrity is then demonstrated through experimental validation. Using this theorem, the corrosion-fatigue entropy generation function is derived, evaluated and employed for structural integrity, reliability assessment and remaining useful life (RUL) prediction of Aluminum 7075-T651 specimens tested.