<div>A tropical cyclone (TC) vortex is an immense, coherent, organized-convective system. Beneath this large-scale organization, is a litany of azimuthally asymmetric convective motions that exist on a spectrum of scales. These asymmetries are especially dominant during periods when the vortex undergoes critical transitions in its intensity and structure. However, the precise nature of influence of the organization of asymmetries on TC intensity change remains an enigma. The inherent difficulty in predicting their behavior is because asymmetries may arise due to different external or intrinsic sources and occur at different spatial and temporal scales while several complex mechanisms act near-simultaneously to dictate their evolution in time. As a result, multiple pathways are possible for a TC vortex that is influenced by these asymmetries. Our preliminary investigations using numerical models made it apparent that there wasn't a single, unifying way to address this problem. In this thesis, I outline multiple novel techniques of diagnosing and predicting which of the many pathways are likely for a TC vortex that is influenced by azimuthal asymmetries. </div><div> </div><div> First, using three-dimensional numerical simulations of a pair of sheared and non-sheared vortices, I demonstrate the diagnostic potential of the juxtaposition in the azimuthal phasing of: </div><div>(i) the asymmetrically distributed vertical eddy flux of moist-entropy across the top of the boundary layer, and the radial eddy flux of moist-entropy within the boundary layer; and (ii) eddy relative vorticity, eddy moist-entropy, and vertical velocity throughout the depth of the vortex. </div><div> </div><div> Second, I introduce an energetics-based diagnostic framework that computes the energy transactions occurring at asymmetries across various length-scales in the wavenumber domain. By applying it to select cases, this thesis uncovers the relative importance of all the energy pathways that support or disrupt the growth of asymmetries within the vortex. Contrary to the traditional explanations of convective aggregation/disaggregation and axi/asymmetrization through barotropic mean-eddy transactions, my thesis reveals that the growth or disruption of asymmetries are predominantly due to (i) the baroclinic conversion from available potential to kinetic energy at individual scales of asymmetries and (ii) the transactions of kinetic energy across asymmetries of different length scales. </div><div> </div><div>Finally, this thesis introduces two further diagnostic frameworks targeted at tackling the problem of real-time forecasting of TC rapid intensity changes. The first is an empirical framework which examines symmetric and asymmetric convection and other state variables within the vortex, and in the environment across a suite of TCs and identifies a set of `important' variables that are significantly different during time periods that precede a rapid intensification as opposed to a rapid weakening. My framework then ranks the variables identified based on how significantly they influence a rapid intensity change in a TC and the amplification factor of any associated variability. We recommend that future observational, and consequent TC modeling and data assimilation efforts prioritize the highest ranked variables identified here. </div><div><br></div><div>The second is a stochastic model wherein a scale-specific stochastic term is added to the equations describing the energy transactions within the TC vortex. By simulating a stochastic forcing that may arise from any scale, I compute the probability of the vortex transitioning into a rapidly intensifying or a rapidly weakening configuration across an ensemble of scenarios. </div><div><br></div><div>In summary, this thesis introduces and applies a variety of diagnostic techniques that help determine the impact of azimuthal asymmetries on TC intensity evolution.</div>

The design of this thesis intends to present that 120¢X Communication and Flux-Weakening Control techniques can be successfully applied to a Digital Signal Processor (DSP) together with the hardware structure of an inverter. Experimental results are shown that utilizing IPM Motor as Drive Motor of Electric Vehicle, 120¢X Communication techniques can reduce ripple torque and maintain the stability of output torque. Furthermore, through Phase advanced control motor, it enables a higher output torque during the mid-lower speed. Using Flux-Weakening Control helps motor from higher output speed to the highest output speed. Moreover, the security of motor driver can be enhanced by designing circuit, which prevents over voltage. The function of motor driver will be better due to the decreased hardware size and increased accuracy that are the advantage of writing DSP scripts to analyze rotor speed.

Submitted by Eduarda Figueiredo (eduarda.ffigueiredo@ufpe.br) on 2015-03-05T14:15:06Z No. of bitstreams: 2 TESE Nayra Vicente.pdf: 6766112 bytes, checksum: f86cc3020d7d4206f08a4438b250092c (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-05T14:15:06Z (GMT). No. of bitstreams: 2 TESE Nayra Vicente.pdf: 6766112 bytes, checksum: f86cc3020d7d4206f08a4438b250092c (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-04-30 / PRH-26, Agência Nacional de Petróleo, Petrobrás S/A / Compactação é um mecanismo relevante em muitos problemas da engenharia geotécnica e de reservatórios, no qual as deformações do meio poroso e o deslocamento dos fluidos no seu interior estão diretamente relacionados. Na indústria de petróleo este mecanismo tem sido abordado devido aos eventos ocorridos no passado que trouxeram grandes consequências econômicas (ex. Mar do Norte - Ekofisk). A compactação, em alguns trabalhos, é apontada como um fenômeno geomecânico resultante de processos físico-químicos na interação rocha mineral-fluido. Neste caso, o fluido é um agente de degradação que enfraquece rocha/solo e compromete seu comportamento mecânico segundo a resistência e rigidez, como caracterizado no efeito water-weakening. Apesar de ser um assunto ainda em discussão, alguns estudos apontam a pressão capilar (sucção) como um parâmetro chave da interação rocha-fluido para este “enfraquecimento”. Além da ação capilar outros mecanismos têm sido utilizados para explicar o fenômeno water-weakening na circunstância da compactação e subsidência, como o intemperismo químico. No entanto, para o entendimento de problemas que envolvem múltiplas físicas é necessário modelos matemáticos capazes de representar os processos simultâneos que ocorrem neste problema. Neste contexto, estudam-se aqui problemas acoplados hidro-mecânico e hidro-mecânico-químico envolvendo o mecanismo de compactação capilar e química pelo efeito do enfraquecimento do solo/rocha devido às interações rocha fluido, abrangendo o fenômeno water-weakening. Para modelar numericamente este enfraquecimento, variáveis associadas à capilaridade e ao processo químico serão consideradas na relação tensão-deformação do modelo constitutivo mecânico. A ferramenta numérica utilizada para as simulações foi o código em elementos finitos CODE-BRIGHT (COupled DEformation BRIne Gas and Heat Transport), formulado para problemas acoplados THMC (termo-hidro-mecanico-quimico). Como modelo constitutivo adotou-se o BBM (Modelo Básico de Barcelona), que é um modelo elasto-plástico que considera o efeito da sucção, introduzindo uma modificação para descrever as deformações plásticas decorrentes do efeito químico, representando a degradação química. Esta proposta foi baseada no modelo químico-elastoplástico de Castellanza e Nova (2004), aplicados a rochas e solos cimentados. Para validação do modelo proposto foram simulados ensaios divulgados na literatura. O modelo foi utilizado também para analisar um exemplo de compactação em reservatório de petróleo e aquífero, no qual foi possível observar que as deformações irreversíveis podem ocorrer tanto devido ao efeito da pressão (pressão capilar/sucção) e estado de tensão bem como, pelo ataque químico aos minerais.

Exhumed faults record the temperatures produced by earthquakes. We show that transient elevated fault surface temperatures preserved in the rock record are quantifiable through microtextural analysis, fault-rock thermochronometry, and thermomechanical modeling. We apply this approach to a network of mirrored, minor, hematite-coated fault surfaces in the exhumed, seismogenic Wasatch fault zone, UT, USA. Polygonal and lobate hematite crystal morphologies, coupled with hematite (U-Th)/He data patterns from these surfaces and host rock apatite (U-Th)The data, are best explained by friction-generated heat at slip interface geometric asperities. These observations inform thermomechanical simulations of flash heating at frictional contacts and resulting fractional He loss over generated fault surface time temperature histories. Temperatures of >similar to 700-1200 degrees C, depending on asperity size, are sufficient to induce 85-100% He loss from hematite within 200 pm of the fault surface. Spatially-isolated, high temperature microtextures imply spatially -variable heat generation and decay. Our results reveal that flash heating of asperities and associated frictional weakening likely promote small earthquakes (M-w approximate to -3 to 3) on Wasatch hematite fault mirrors. We suggest that similar thermal processes and resultant dynamic weakening may facilitate larger earthquakes. (C) 2017 Elsevier B.V. All rights reserved.

The master’s thesis deals with the design of a synchronous motor with embedded magnets. First of all, the general theory of synchronous motor, which is focused on field-weakening drive, is described. Then a 6-pole and a 8-pole version of the motor with embded magnet, which has 65 kW and 3000 rpm is complexly designed. Motors are compared with each other and with a motor with surface magnets, that was also designed in this work. Finally, all motors are compared with a mafufactured and measured motor.

Rotor designs for permanent magnet synchronous machines suitable for field weakening operation have been evaluated for use with an existing drive system. The designs have been simulated with the FEM-based software Finite Element Method Magnetics (FEMM). Based on the results two different internal magnet rotors have been constructed and tested. Both designs significantly improved the speed range while maintaining or improving magnet utilisation. The implementation of field weakening algorithms in drive electronics is complex and need thorough optimisation for stable operation. Internal permanent magnet rotors are a good alternative to surface mounted designs and enables a wider speed range through improved field weakening capabilities.

This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3. A design approach based on the CPSR contour plot in aninterior permanent magnet (IPM) parameter plane is derived toobtain the possible designs that meet all the designspecifications and the targeted CPSR. This study provides thepossible alternative designs for the subsequent futureprototype motors. An analytical approach to estimate the iron loss in PMsynchronous machines is developed and included in the designprocedure. The proposed technique is based on predicting theflux density waveforms in the various regions of the machine.The model can be applied at any specified load condition,including the field-weakening operation region. This model canbe ultimately embedded in the design process for a routine usein loss estimations. The first prototype motor with an inset permanent magnetrotor has been built and the available measurements are used tovalidate the design performance. In particular, the thermalanalyses based both on the lumped-circuit approach and thenumerical method are compared with the measured results. Asecond and possibly a third prototype motor targeting a widerand higher performance will be carried out in the continuingphase of the project. Keywords:Constant Power Speed Range, Electric Vehicles,Field-weakening, Reference Flux Linkage, Iron Loss, PermanentMagnet Synchronous Motor, Thermal Analysis / <p>QCR 20161026</p>

Decades of research have fostered a greater understanding of the environmental controls that drive tropical cyclone (TC) intensity change, yet the community has achieved only small improvements in intensity forecasting. Numerous environmental factors impact TC intensity, such as vertical wind shear and sea surface temperatures (SSTs), but little research has focused on establishing if SST change under the TC, or SST gradients, influence these intensity changes. This study investigated three methods to compute SST gradients. The first method calculated the SST change within fixed distances along the track. In the second and third methods, the SST was calculated over the distance traversed by the TC in two separate six-hour periods. By examining 455 24-hour weakening episodes in the eastern North Pacific, this study revealed that the first SST gradient method explained the highest 24-hour weakening variance for TCs located within SSTs at or lower than 26.5 degrees C.

The issue of legal pluralism in contemporary society Abstract This work aims to describe the phenomenon of legal pluralism, its expressions and functioning in contemporary society and evaluate the findings in connection with the weakening role of the state. The role of law is changing more and more in today's global world, especially in an increasingly less homogeneous society. The plurality of contemporary society is increasingly penetrating normative systems, which in turn affects the very functioning of the state as an authority. Legal pluralism reflects the life of contemporary society. From the perspective of legal pluralism, we gain a new understanding of law. The concept of legal pluralism enables the law to respond in a more flexible way to the plurality of contemporary society, as law increasingly faces difficulties in reflecting the social reality of contemporary society. Related to laws that do not reflect this plurality is a growing distrust of people in the state and its institutions, which contributes to the weakening role of the state. One of the possibilities for the state to strengthen its role is to restore confidence of the citizens in the state and its institutions. This can be also achieved by creating good written law. State law should take into account the phenomenon of legal...

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