La mesure des champs électromagnétiques très basses fréquences en mer est utilisée pour de nombreuses applications, dont les principales sont militaires et géophysiques. Les besoins pour ces applications sont des capteurs capables d'effectuer des mesures à très basses fréquences avec un niveau de bruit inférieur au nV.m^(-1).Hz^(-1/2).Les électromètres commerciaux et académiques utilisés actuellement pour la mesure des champs électriques en mer sont à mesure de tension. Leur inconvénient majeur est une remontée de bruit aux basses fréquences, due à l'électronique d'amplification du signal. Une autre méthode de mesure des champs électriques en mer consiste à mesurer le courant traversant un dispositif de faible impédance. Nous avons conçu un électromètre à mesure de courant et magnétomètre au sein du même capteur, en essayant de pallier les défauts des électromètres passés et actuels.Dans un premier temps, nous décrivons le milieu dans lequel le capteur sera amené à fonctionner, puis les applications auxquelles il est destiné, et enfin l'état de l'art des capteurs existant et leurs limites.Nous décrivons ensuite de manière détaillée le comportement du capteur. En particulier, nous déterminons par simulation et de manière expérimentale les différentes fonctions de transfert du capteur, en fonction de ses caractéristiques géométriques et de son environnement.Après avoir présenté plusieurs architectures possibles d'électromètres répondant aux objectifs fixés, nous utilisons les résultats obtenus au chapitre précédent pour dimensionner un électromètre dont la conductivité équivalente n'est pas forcément égale à celle de l'eau de mer. Ce degré de liberté supplémentaire par rapport aux contraintes de conception des électromètres à mesure de courant passés permet d'améliorer les performances du capteur. Enfin nous proposons deux méthodes de calibration de l'électromètre, sans connaissance a priori de son environnement.Enfin nous caractérisons les différents éléments d'un prototype de laboratoire, et nous présentons les résultats des tests de ce prototype complet. / The measurement of electric and magnetic fields at sea is of great interest for many applications (geophysics, oil prospection, vessels detection, etc.) In all cases, measurements at very low frequency with a very low noise are required.Most marine electrometers measure the potential difference between two separated electrodes. Their noise level is very good but increases when frequency decreases, due to amplification electronics. Another type of electrometers is based on a low impedance current measurement system. We designed a current based electrometer, which is as well able to simultaneously measure the magnetic field, trying to solve the problems of former devices.First, we describe the medium in which the sensor will be used, the applications for which it is intended, and the state of the art of existing sensors and their defects.We then describe in detail the behavior of the sensor. In particular, we determine by simulation and experimentally the different transfer functions of the sensor, depending on its geometrical characteristics and its environment.After presenting several potential architectures of electrometers meeting the targets, we use the results obtained in the previous chapter to scale an electrometer, whose equivalent conductivity is not necessarily equal to that of seawater. This additional degree of freedom in comparison with the design constraints of the former current measurement electrometers enables us to improve the performance of the sensor. Finally we propose two calibration methods of the electrometer, without prior knowledge of its environment.Finally we characterize the different elements of a laboratory prototype, and we present the results of the tests of the complete prototype.

No description available.

Objectives: Pelvic vein incompetence (PVI) has been suggested as a cause for chronic pelvic pain. The overall objective of this thesis is to determine how PVI affects women, identify suitable methods of diagnosis and provide evidence regarding its association with chronic pelvic pain. This thesis will also evaluate the evidence behind its treatment. Methods: Four observation studies were completed during this thesis. A characterisation study encompassing 120 participants was performed to determine symptoms commonly experienced by women with PVI. Two observation studies analysed the ability of trans-vaginal ultrasound to detect PVI and compared its accuracy with reflux venography; considered the reference standard. A further 70 participants were recruited in a case-control study to determine the prevalence of PVI in women with and without chronic pelvic pain. A randomised control trial treating women with PVI and pelvic pain was also designed. Results: Women with PVI had an increased frequency of CPP when compared with healthy controls or women with varicose veins. This pain was associated with the menstrual cycle and intercourse. It was also found to frequently radiate into the upper thighs. Trans-vaginal ultrasound was shown to have a sensitivity and positive predictive value of 100% and 95% respectively when compared with reflux venography. The frequency of PVI in women with chronic pelvic pain was found to be 47% compared with 25% in women with no history of CPP (p < 0.001). Conclusion: The results of this thesis suggest PVI to be a possible cause of CPP in women and likely to be under-diagnosed. It can be identified by trans-vaginal ultrasound although the degree of accuracy is still yet to be determined. PVI merits further research and attention from clinicians and researchers. The proposed randomised control trial is needed both to further understanding of the role of PVI in CPP and to assess the efficacy of an under-researched treatment approach currently used in practice.

Objetivo: Desenvolver um modelo experimental de aneurisma cerebral em artéria de suínos. Secundariamente, avaliar o processo de organização do trombo e de formação de tecido fibrocelular dentro do aneurisma com o tratamento endovascular utilizando molas revestidas (Matrix) comparadas às sem revestimento (GDC). Materiais e Métodos: Em 10 suínos sadios, com peso variando entre 16 e 20 kg, sendo 6 machos e 4 fêmeas, foi realizada a cirurgia de formação de aneurisma nas carótidas bilateralmente, através de arteriotomia e anastomose término-lateral com segmento de veia jugular. O diâmetro médio dos aneurismas era de 3 mm (variação de 2 a 4mm). Procedia-se então ao tratamento endovascular dos aneurismas divididos do seguinte modo: grupo I, embolização do aneurisma da carótida esquerda com mola de platina (GDC); grupo II, embolização do aneurisma da carótida direita com mola de platina revestida com copolímero - PGLA 90/10 (Matrix). Após 14 dias, eram retiradas as lesões e analisadas microscopicamente, comparando-se a formação de trombo recente ou trombo organizado no interior de cada aneurisma. Para isso, foi criada uma escala de caracterização das fases do processo de trombose (Escores de 1 a 4). O Escore 1 era definido como a presença de trombo inicial ou recente; o Escore 2 era categorizado como a presença de leucócitos em diferenciação contendo fibrina e absorção das hemácias e plaquetas, porém intercalados com zonas contendo trombo recente. No Escore 3, observavase a presença de leucócitos em diferenciação contendo fibrina e no Escore 4, a presença de tecido fibrocelular contendo fibras de colágeno. A análise estatística foi realizada de modo pareado, através do Teste de Wilcoxon, sendo os dados processados no programa SPSS 12.0. O nível de significância mínimo adotado foi de 5%. Resultados: Um animal (macho) foi excluído do estudo devido à formação de abscesso cervical, restando, portanto, 9 animais (18 aneurismas para avaliação). Na análise do processo de organização do trombo, utilizou-se a graduação por escores, obtendo-se no grupo I, 88,8% de casos de trombo recente (Escore 1) e 11,1% de casos de trombo em organização ainda contendo coágulo (Escore 2). No grupo II, obteve-se 11,1% de casos com escore 1 , 11,1% com escore 2, 55,5% de casos de trombo organizado com tecido fibrocelular frouxo (Escore 3) e 22,2% de casos de tecido fibrocelular denso contendo colágeno (Escore 4). Houve diferença estatística a favor do grupo II, por meio do Teste de Wilcoxon (p=0,008). Conclusão: O modelo experimental de aneurisma de pequenas dimensões utilizado neste estudo foi adequado e permitiu a realização do tratamento endovascular testando dois tipos de molas. Por meio da análise histológica baseada em escala criada para avaliar a organização do trombo, pôde-se verificar diferença significativa a favor das molas com revestimento de copolímero. / Background and Objectives: To develop an experimental model in a pig that could be used for analysis of patency of cerebral aneurysms is the goal of this study. Adictionaly, it aims to evaluate the degree of thrombosis after embolization with two types of coils: copolymer-coated coils (Matrix) and uncoated platinum coils (GDC). Method: In a total of 10 Large-White pigs, small aneurysms (with a mean diameter of 3 mm) were created in both carotid arteries (6 males and 4 females) weighing 16 to 20 kg (mean: 18 kg). Embolization was performed with GDC platinum coils on the left side and with a coil coated with Matrix polymer on the right side. After 14 days, angiography was performed to confirm exclusion of the aneurysm. Before euthanasia with a lethal dose of potassium chloride, the carotid artery was removed in one piece, including the aneurysm. The specimens were cut into sections, including the mid portion of the aneurysm and the artery above and below the aneurysm, and stained with hematoxylin- eosin for histological analysis. A graduated scale with progressive scores ranging from 1 to 4 was used to evaluate the organization of the thrombus. Score 1 indicated clusters of platelets, white blood cells, and red blood cells; Score 2 showed the presence of differentiating white blood cells containing fibrin and absorption of red blood cells and platelets, interspersed with zones containing a recent thrombus; Score 3 corresponded to the presence of differentiating white blood cells containing fibrin, which characterized a loose fibrocellular tissue; and Score 4 indicated the presence of fibrocellular tissue containing collagen fibers, which characterized an incipient dense fibrocellular tissue The data were described as frequency and percentage using the Wilcoxon test for findings involving thrombosis scores. The data were analyzed using the SPSS 12.0 software, and the minimum significance level was set at 5%. Results: One animal (male) was excluded from the study due to abscess formation near the anastomosis. Therefore, 9 animals (18 aneurysms) were assessed. A score was used for analyzing the organization of the thrombus. In group I, 88.8% had score 1, 11.1% score 2, but no cases showed scores 3 and 4. In group II, 11.1% had score 1, 11.1% score 2, 55.5% score 3, and 22.2% score 4. The Wilcoxon test was applied, revealing a significant difference (p=0.008) between the scores for group I and group II in the course of 14 days. Conclusion: The experimental aneurysm developed in this study was suitable for assessing the patency of small aneurysms (measuring, on average, 3 mm) after coil embolization. The organization of the intra-aneurysmal thrombus after 14 days was verified using the progressive score, which indicated a significant difference between the group treated with the Matrix coil and that treated with GDC.

Consumer demand for fresher foods has necessitated the use of non-thermal technologies in processing milk. Two Dean Flow UV reactors (1/16" ID × 1/32" Thick & 1/8" ID × 1/32" Thick) were designed in the laboratory. The objective of this study was to examine the efficacy of designed UV reactors at four levels of Reynolds numbers (Re) on inactivation of Escherichia coli W 1485 cells and Bacillus cereus spores in raw cow milk (RCM), commercially processed skimmed cow milk (SCM) and raw soymilk (RSM). RCM, SCM and RSM were inoculated separately with E. coli W 1485 and B. cereus spores and were treated through the designed reactors for a residence time of 11.3 ± 0.1 s, equivalent to an UV dose of 0.05 J/ml in 1/16" ID reactor and 0.02 J/ml in 1/8" ID reactor. Four levels of Re were tested in the range of 181-1372. The influence of tube diameter (thickness of milk exposed to UV) and Re (indicator of turbulence) at constant residence time (11.3 ± 0.1 s) on inactivation of both the bacteria in both the UV reactors was analyzed using two-way ANOVA with proc GLM in SAS software. E. coli was inactivated to non-detectable levels (≥7.8 log10 CFU/ml) in SCM from the second level of Re (532.2) in 1/16" ID reactor. E. coli was also inactivated significantly (> 5logs) in RSM at the highest Re (1372) but this was not achieved in the case of RCM (712.7). Increasing the residence time to 14.2 s or greater (17 s) (equal to UV dose of 0.06 and 0.08 J/ml) inactivated E. coli cells to non-detectable levels in RCM using 1/16" ID reactor at the highest level of Re (712.7). Reduction of E. coli cells were in the range of 0.45-7.78 logs whereas B. cereus spores were in range of 1.06- 3.29 logs in all types of milk used in this study. The interaction effect of tube diameter and Re was statistically significant for E. coli cells in RCM, and SCM; B. cereus spores in SCM, and RSM (p < 0.05) whereas this was statistically non significant for E. coli cells in RSM and B. cereus spores in RCM (p > 0.05). Main effects of Reynolds number, and tube diameter were statistically significant (p < 0.05) on inactivation of B. cereus spores in RCM and E. coli cells in RSM. Inactivation efficiencies for both bacteria were higher in 1/16" ID reactor than 1/8" ID reactor. Using the 1/16" ID reactor at highest level of Re (RCM Re = 712.7, RSM Re = 1372), inactivation of standard plate count (SPC) present in RSM and RCM, and lipid oxidation during storage period (0, 1, 3 and 7 days) were measured. Inactivation of SPC in UV-treated RSM (3 logs) was lower than thermal pasteurization at 72°C for 20 s (7 logs). In case of RCM, the SPC was inactivated to 1.9 logs from 4.2 logs. Sensory evaluation (olfactory) of UV treated, untreated (milk passed through the 1/16" ID reactor while the UV lights turned off), and fresh RCM (control) suggested no change in flavor after treatment and upto 1 day after storage in refrigerated condition, but a perceivable change in the quality of UV treated and untreated cow milk were observed during the 3rd and 7th days when compared with fresh RCM (milked same day). RCM was treated with different UV dose levels (0.04, 0.05, 0.08, 0.12 and 0.16 J/ml) to examine the effect of UV light on malondialdehyde and other reactive substances using TBARS test kit. Reactive substances such as malondialdehyde content increased as the UV dose increased. The presence of malondialdehyde and other reactive substances were not significantly different (p < 0.05) in both thermal and UV-pasteurized soymilk; whereas these substances were found to be higher in UV-treated RCM after 7 days of storage than the untreated milk stored for 7 days at 4 °C and the fresh RCM. The designed reactors 1/16" ID and 1/8" ID reactors were useful to inactivate bacteria present in milk. But, the inactivation efficiency was more in 1/16" ID reactor than 1/8" ID reactor.

Les progrès concernant l’autonomie des batteries ont rendu le véhicule électrique vraiment compétitif. Cependant un problème n'est pas vraiment résolu, celui du temps de charge des batteries qui reste long même avec des bornes de forte puissance. La charge par induction peut compenser en partie ce handicap grâce à une infrastructure quasi-transparente pour l'utilisateur, basée sur l'équipement des zones de stationnement.L'objectif de cette thèse est d’étudier le potentiel et les limitations de la charge par induction, éventuellement par l'introduction de nouveaux concepts, dans la gamme des puissances de plusieurs dizaines de Kilowatts et sur des distances supérieures à 10cm entre l’inducteur et l’induit. L'obtention de bons rendements et le respect de dimensions en accord avec l'intégration dans le véhicule sont des points essentiels de la démarche.Dans un premier temps, différentes topologies de compensation de l'énergie réactive, indispensable dans cette application, sont comparées et la topologie dite Série-Série (SS) est finalement retenue. De la même façon, différentes architecture d’électronique de puissance sont évaluées. L’architecture correspondant à l'utilisation d'un onduleur primaire commandé en phase shift à fréquence variable, et d'un simple pont de diode secondaire est adoptée. Elle permet de réguler le courant injecté dans les batteries tout en simplifiant l’électronique de puissance, c.à.d. sans utiliser de convertisseurs DC-DC ni au primaire, ni au secondaire.Un outil de calcul des pertes dans le fil de Litz est ensuite mis en place. Il permet d'évaluer les pertes dans les bobinages en fonction de la section du fil et du diamètre des brins, l'objectif étant de trouver la combinaison "section de cuivre/diamètre de brins" minimisant les pertes.La troisième étape consiste à mettre en place des outils de conception analytiques complétés par des simulations "éléments finis" pour concevoir les bobinages du coupleur électromagnétique ainsi que son blindage magnétique. Des montages expérimentaux à petite échelle permettent une première validation de ces outils de conception. Enfin un algorithme d’optimisation est développé.Sur la base des solutions identifiées dans la première partie, les outils de conception ont été finalement utilisés pour concevoir un démonstrateur de 22kW, capable de transférer l’énergie sur une distance de 25cm entre l’inducteur et l’induit. Ce démonstrateur a été testé avec succès à la puissance nominale. Le rendement mesuré est de 95% lorsque les bobines primaire et secondaire sont alignées. / Scientific progress in battery field related to autonomy has made electric vehicles really competitive. However, there is a problem that hasn’t been solved yet, the duration of the charge which still high, even if high power chargers are used. Inductive charging could be a solution to that problem because the infrastructure can become almost transparent for the user if it is implemented in car park areas.The aim of this PhD work is to evaluate the potential and the limitations of inductive charging, to identify eventual new concepts, in a fast charge power range (few tens of Kilowatts) and with air gaps higher than 10cm.First, different topologies of reactive energy compensation are compared and the Series-Series (SS) topology is selected. Then, in the same way, different power electronics architecture are compared. The architecture using a phase-shifted DC-AC converter to supply the primary side and a simple power bridge to supply the secondary side is adopted. This architecture allows regulating the current in the batteries without using DC-DC converters neither on the primary side nor on the secondary side.Then, a software is implemented that is able to calculate losses in Litz wire, as a function of the wire section and the strands diameter, the aim being to choose a Litz wire that minimizes the losses in the windings.The third step is the implementation of a tool dedicated to the design of the primary and secondary coils and of the magnetic shields. The tool is based on analytic equations and finite elements simulations. The design tool is validated by means of reduced scale experiments. Finally, an optimization algorithm is implemented.Considering the solutions identified in the first part, the previous design tools are finally used to design a 22kW prototype able to transfer energy through an air gap of 25cm. This prototype has been successfully tested at nominal power. An efficiency of 95% has been measured when the two coils are aligned.

O presente trabalho trata de uma modelagem eletromagneticamente acoplada e fracamente acoplada ao problema mecânico do processo de conformação eletromagnética (EMF). Este usa bobina espiral plana, aplicada na deformação de chapas finas e planas para obter geometrias finais rasas. Um método de solução numérica é usado para o problema eletromagnético, o qual foi desenvolvido no software Matlab e utiliza o software Abaqus/Explicit para verificação da geometria deformada após a aplicação da força transiente de origem eletromagnética. O método foca especificamente no cálculo da densidade de fluxo magnético em pontos específicos usando a lei de Biot-Savart e análise do circuito que modela o processo de conformação eletromagnética, sendo que as indutâncias deste circuito são calculadas e fazem o acoplamento entre os fenômenos elétricos e magnéticos. Os cálculos das correntes de descarga e induzidas e perfil da força de origem eletromagnética são realizados para o instante inicial, sem considerar o movimento da chapa. O perfil da força de origem eletromagnética ao longo da chapa é calculado para diversos instantes, sendo este um dos dados de entrada no software Abaqus/Explicit através de uma sub-rotina acessível ao usuário (VDLOAD) obtendo-se a geometria da chapa deformada. A rotina de cálculo discretiza o problema eletromagnético como um sistema de equações diferenciais ordinárias (ODE) para calcular a corrente de descarga da bobina atuadora e as induzidas na chapa metálica. Experimentos, sem chapa acoplada, e com chapa fixa ou deformando foram realizados com a aquisição da corrente de descarga, medição da densidade de fluxo magnético, velocidade de deformação e geometria da chapa deformada, demonstrando uma boa correlação com o método de cálculo proposto. O presente trabalho fornece importantes informações para o projeto de sistemas de conformação eletromagnética sem a necessidade de uma função da corrente de descarga como dado de entrada para solução do problema eletromagnético. / This thesis deals with modeling and numerical simulation electromagnetically coupled and loosely-coupled to the mechanical problem for process of the electromagnetic forming. This uses flat spiral coil, applied to the deformation of thin and flat sheet metal to obtain shallow end geometries. This method uses a numerical solution to the electromagnetic problem, which was developed in the software Matlab and uses the software Abaqus/Explicit for verification of the deformed geometry after applying of the transient force of origin electromagnetic. The method focuses specifically on the calculation of the magnetic flux density at specific points using the Biot-Savart law and circuit analysis that modeling of electromagnetic forming process and the inductances of this circuit are calculated and couple the electric and magnetic phenomena. Calculations of discharge and induced currents, profile force of origin electromagnetic are performed for the initial time, without considering the motion of the sheet metal. The profiles force of origin electromagnetic along the sheet metal is calculated for several instants, which are input data in software Abaqus/Explicit using a user-routine (VDLOAD) obtaining the deformed geometry of the sheet metal. The calculation routine discretizes the electromagnetic problem as a system of ordinary differential equations (ODE) to calculate the discharge current of the actuator coil and induced currents in the metal sheet. Experiments without coupled sheet metal, and fixed or deforming sheet metal were performed with the acquisition of the discharge current, measurement of magnetic flux density, velocity of movement and deformation geometry of the sheet metal, demonstrating a good correlation with the proposed method of calculation. This study provides important information for the design of the electromagnetic forming systems without the need for a function of discharge current as input for solution of the electromagnetic problem.

Made available in DSpace on 2014-06-11T19:31:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-19Bitstream added on 2014-06-13T20:01:53Z : No. of bitstreams: 1 araujo_fbc_dr_sjc.pdf: 312103 bytes, checksum: 3f21d0423598e73724ad1f5cf82e2469 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Analisaram-se separada e comparativamente três marcas comerciais de elásticos ortodônticos sintéticos e de molas de NiTi (MORELLI, ORMCO e GAC), quanto à degradação da força sofrida por estes materiais em função do tempo, quando submetidos a simulação das condições bucais. Os elásticos e molas foram inicialmente termociclados (temperaturas de 15°C e 45°C), em seguida estirados em 20mm, imersos em saliva artificial a 37°C e desativados em 0,5mm semanais. As leituras da quantidade de força gerada pelas amostras foram realizadas nos momentos: inicial, 1, 24, 48 horas, 7, 14, 21 e 28 dias. Observou-se significativa redução na quantidade de força gerada pelos elásticos na primeira hora de ativação, que variou de 49,5% a 53%, enquanto que para as molas a degradação foi signicativamente menor, com valores entre 4,2% e 18,1%. Ao término de 28 dias de testes, as amostras de elásticos sofreram redução média na quantidade de força gerada entre 82,7% e 91,2% (GAC-82,7%, ORMCO-86,0% e MORELLI- 91,2%) já as amostras de molas apresentaram degradação média de força entre 17,5% e 32,2% (MORELLI-17,5%, ORMCO-27,3% e GAC-32,2%). Concluiu-se que, em geral, os elásticos promoveram maior índice inicial de força que as molas, mas após as primeiras 24 horas de ativação a quantidade de força gerada pelos elásticos era menor que a promovida pelas molas, que assim apresentaram níveis médios de força mais constantes que os elásticos ao longo dos testes. / Three commercial marks of synthetic elastics and NiTi coil springs (MORELLI, ORMCO, GAC) were separately and comparably analyzed, according to the force degradation generated by these materials, because of the time, when maintained stretched in artificial salivary, 37°C. The synthetic elastics and NiTi coil springs were thermal- cycled (15°C-45°C) and stretched in 20mm, and this stretch was reduced in 0,5mm weekly. The readings of the amount generated for elastics and coil springs were done in the intervals 0, 1, 24, 48h, 7, 14, 21 and 28 days. Where observed significative reduction on the amount of force generated for the elastics in the first hour of the activation (49,5%- 53%), and 82,7% - 91,2% in 28 days of the tests ( MORELLI - 91,2%, ORMCO - 86,0%, GAC - 82,7%);, while the generated force for NiTi coil springs suffered a reduction of 4,2%- 18,1%, in the first hour of the experimentation and 17,5% - 32,2% in 28 days of the stretch (MORELLI - 17,5%, ORMCO - 27,3%, GAC - 32,2%). We conclude that for most elastics delivered larger initial force that NiTi coil springs, but after 24 hours of activation the NiTi coil springs delivered larger force that the elastics and generated level of the force more constant that elastics.

Submitted by Fernando Souza (fernando@biblioteca.ufpb.br) on 2017-12-12T13:06:08Z No. of bitstreams: 1 Arquivototal.pdf: 47472697 bytes, checksum: 89ff6fb9f3545a4993765225306c90e9 (MD5) / Made available in DSpace on 2017-12-12T13:06:08Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 47472697 bytes, checksum: 89ff6fb9f3545a4993765225306c90e9 (MD5) Previous issue date: 2011-09-01 / In current times, industrial companies, and specif]cally in the steel industry have been revising its processes and adopting modern productive models which focused on improving quality and cost reduction of their products. In this context the area of production planning and control has the job of integrating ali the areas of the production system receiving and providing information and making decisions regarding the customer service. In the far downstrearn in the chain has warehouses dispatch of finished products that with a good layout associated with proper handling and storage contribute to the company goais. This study used the rnethodoiogy of case study for anaiyzing three scenarios of using a shipping coii yard of a big steel company in order to prornote a more efficient handling and storage of materiais that circulate in this environment so to address both the area of production, which seeks to maximize its production capacity as the area of iogistics, seeking to serve the custorners within agreed quality and in order to harmonize interests and objectives of each area. After each scenario analyzed its advantages and disadvantages, considering the sarne criteria of coils inputs and outputs for ali scenarios, we carried out a benchmarking effort to identify the best working situation. The results show that the °scenario three" behind the best results, because it has a better use of the work area of the yard, crane uses the resource more eveniy over time, it demand iess time spent for ciearance vehicle road and rail, without losing sight of general meeting of requirements of the company with respect to production, quality, customer service and investment. / Em tempos atuais, as empresas industriais, e mais especificamente do setor siderúrgico, vêm revisando seus processos e adotando modelos produtivos mais modernos que priorizam a melhoria da qualidade e redução de custo de seus produtos. Neste contexto a área de planejamento e controle da produção tem a função de integrar todas as áreas do sistema produtivo recebendo e fornecendo informações e tomando decisões visando o atendimento ao cliente. A jusante desta cadeia tem-se os armazéns de despacho de produtos acabados que com um bom layout associado a técnicas de movimentação e armazenagem adequadas contribuem para o atigimento dos objetivos da empresa. Este trabalho utilizou da metodologia de estudo de caso para a análise de três cenários de utilização de um pátio de despacho de bobinas específico de uma siderúrgica de grande porte com o objetivo de promover uma movimentação e armazenagem mais eficiente dos materiais que circulam neste ambiente de forma a atender tanto a área de produção, que busca maximizar sua capacidade produtiva como a área de logística, que busca atender aos clientes no prazo e qualidade acordados, de forma a compatibilizar os interesses e objetivos de cada área. Após cada cenário analisado em suas vantagens e desvantagens, considerando o critério de entradas e saídas de bobinas iguais para todos os cenários, realizou-se uma avaliação comparativa buscando identificar a melhor situação de atividade. Os resultados alcançados mostram que o "cenário 3" trás melhores resultados, pois tem um melhor aproveitamento da área útil do pátio, utiliza o recurso ponte rolante de forma mais homogenia ao longo do tempo; tem menor tempo de permanência de veículo para despacho rodoviário e ferroviário, sem perder de vista o atendimento aos requisitos gerais da empresa com relação à produção, qualidade, atendimento a clientes e investimentos.

A união por conformação eletromagnética de perfis tubulares de alta condutividade elétrica é um processo inovador e limpo que pode substituir com sucesso os processos convencionais de união baseados na fixação mecânica por parafusos, rebites, soldagem e adesivos estruturais. Esta tecnologia funciona a temperatura ambiente, permite a união de materiais diferentes e oferece potencial para promover novas aplicações na montagem de estruturas leves. Neste trabalho busca-se compreender a união por interferência de tubos por cravamento eletromagnético em termos de seus principais parâmetros com o objetivo de identificar a influência na resistência global das uniões e estabelecer a faixa útil de condições operacionais do processo. Inicialmente são apresentados os fundamentos teóricos do processo de conformação eletromagnética e suas principais variantes operacionais, seguido de um resumo do estado atual do conhecimento da aplicação desta tecnologia na união de perfis tubulares no qual é verificado que os parâmetros mecânicos são a tensão residual no mandril, a área e forma da zona de união e o coeficiente de atrito entre os componentes. Entretanto, tais parâmetros estão relacionados de forma complexa com o processo de cravamento eletromagnético, a começar pela energia e a distribuição do pulso de pressão magnética gerados pela máquina e ferramenta que “disparam” o processo de conformação, a folga inicial entre componentes, o material dos componentes e, a geometria, forma e rugosidade do mandril. O estudo experimental foca a união por interferência de tubos de alumínio (AA6082-O) com mandris de aço (AISI 1045) e alumínio (AA6082 nos estados O e T6) investigando de forma gradual a influência de parâmetros do processo na resistência mecânica (à tração) deste tipo de uniões. Os resultados obtidos demonstram que a resistência mecânica da união e os modos de falha associados são diretamente relacionados com os parâmetros de processo e condições do mandril. Além disso, outras importantes contribuições são apresentadas em relação à instrumentação para medição de fluxo magnético e eficiência global do processo e para o desenvolvimento e aplicações industriais desta tecnologia. / Joining of tubular profiles with high electrical conductivity by electromagnetic forming (EMF) is an innovative and clean technology that can successfully replace conventional joining technologies based on mechanical fixing with fasteners, rivets, welding and structural adhesives. The technology works at room temperature, allows joining dissimilar materials and offers potential to foster new applications in the assembly of lightweight tubular frame structures. This work investigates the interference-fit joining of tubes by electromagnetic crimping in terms of its major parameters with the aim of identifying their influence on the overall strength of the joints and establishing the useful range of process operating conditions. Initially, the theoretical principles of EMF and its main operational process variants are presented, followed by a summary of the current state of the knowledge of its application in the joining of tubular profiles in which it is found that the mechanical parameters are the residual stress at the joint interface, the area and shape of the joint interface and the friction coefficient between the joining partners. However, these parameters are related in a very complex way with the electromagnetic crimping process parameters, starting with the charging energy and by the machine and tool which generates the distribution of the magnetic pressure pulse that “triggers” the forming process, the initial gap between joining partners, the mandrel properties such as material, geometry, shape and surface roughness. The experimental study focuses the interference-fit of aluminum tubes (AA6082-O) on mandrels made of different materials and metallurgical conditions (AISI 1045, AA6082-O and AA6082-T6) and, therefore, the process is analyzed by the gradual influence of other process parameters aiming to achieve high strength joints. Results show that the joint strength and the associated failure mechanisms are directly related to process parameters and mandrel conditions. In addition, other important contributions are presented regarding the instrumentation for measuring the magnetic flux and overall process efficiency and to the development and implementation of this technology in industrial processes.