To see the other types of publications on this topic, follow the link: UHSS.
Dissertations / Theses on the topic 'UHSS'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 39 dissertations / theses for your research on the topic 'UHSS.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Li, Nan. "Fundamentals of materials modelling for hot stamping of UHSS panels with graded properties." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/29134.
Full textAbstract:
The aim of this study is to develop the fundamentals of materials modelling to enable effective process control of hot stamping for forming UHSS panels with graded properties for optimised functional performance. A selective heating and press hardening strategy is adopted to grade the microstructural distribution of a press hardened component through differential heat treatment of the blank prior to forming. Comprehensive material models, to enable prediction of austenite formation and deformation behaviours of boron steel under hot forming conditions, as well as the dynamic response of a press hardened part with tailored properties in collision situations, have been developed based on experimental investigations and mechanism studies. The research work is concerned with four aspects: feasibility of the selective heating and press hardening strategy, austenite formation in boron steel during selective heating, thermo-mechanical properties of boron steel under hot stamping, and mechanical properties of boron steel with various microstructures at room temperature. Feasibility studies for the selective heating and press hardening strategy were carried out through a designed experimental programme. A lab-scale demonstrator part was designed and relevant manufacturing and property-assessment processes were defined. A heating technique and selective-heating rigs were designed to enable certain microstructural distributions in blanks to be obtained. A hot stamping tool set was designed for forming and quenching the parts. Test pieces were formed under various heating conditions to obtain demonstrator parts having variously graded microstructures. Microstructural distributions in the as-formed parts were determined through hardness testing and microstructural observation. Ultimately, the structural performance of the parts was evaluated through bending tests. Heat treatment tests were performed to study the formation of austenite in boron steel during selective heating. Characterisation of the effects of heating rate and temperature on transformation behavior was conducted based on the test results. A unified austenite formation model, capable of predicting full or partial austenite formation under both isothermal and non-isothermal conditions, was developed, and determined from the heat treatment test results. Hot tensile tests were performed to study the thermo-mechanical properties of the austenite and initial phase (ferrite and pearlite) of boron steel. The viscoplastic deformation behaviours of the both phase states were analysed in terms of strain rate and temperature dependence based on the test results. A viscoplastic-damage constitutive model, capable of describing the thermo-mechanical response of boron steel in a state corresponding to hot stamping after selective heating, was proposed. Values of constants in the model for both the austenite and initial phase were calibrated from the hot tensile test results. Dynamic and quasi-static tensile testes combined with hardness testing and microstructural observation were carried out to study the mechanical properties of press hardened boron steel with various microstructures at room temperature. Based on the results, the strain rate sensitivity of the martensite and initial phase of boron steel was characterised; the relationships between mechanical properties (true ultimate tensile strength, 0.2% proof stress, elongation, and hardness) and phase composition (volume fraction of martensite), for boron steel with various microstructures, were rationalised. Finally, a viscoplastic-damage constitutive model, capable of predicting the mechanical response of a press hardened boron steel part with graded properties being subjected to crash situations in automobiles, were developed, and determined from the test results.
2
Steffens, Benjamin R. [Verfasser]. "Hydrogen assisted cracking of UHSS for military aerospace applications / Benjamin R. Steffens ; Bundesanstalt für Materialforschung (BAM), Berlin." Hamburg : Helmut-Schmidt-Universität, Bibliothek, 2018. http://d-nb.info/1162511052/34.
Full text
3
Tolf, Erik. "Challenges in Resistance Welding of Ultra High Strength Steels." Licentiate thesis, KTH, Svetsteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-167985.
Full textAbstract:
Increasing the use of Ultra High Strength Steels (UHSS) in vehicle bodystructures is important for reducing weight and cutting CO2 emissions. This thesis investigates challenges in resistance welding that can be a barrier to implementing UHSS as a replacement for low strength steels in vehicle structures. Empirical research has been performed to offer new approaches for improved joint strength and to increase knowledge on cracking mechanisms in resistance projection welding and resistance spot welding of UHSS. By optimising the current build-up phase and peak current during the first milliseconds of weld time, it was shown that the strength could be improved by up to two-fold for projection welded joints. An approach to improve the ductility and strength of resistance spotwelds in UHSS using reduced cooling time was unsuccessful. The reduced cooling rate after weld metal solidification did not fully create the desired softened microstructure. The study on the surface cracking mechanism in resistance spot welded dual-phase UHSS showed that cracking is linked to the galvanization method. It is proposed that formation of aluminium oxide layers on the electrode tips increases the surface temperature and thereby increases the probability for liquid metal embrittlement and surface cracking.QC 20150526
4
Cora, Omer Necati. "DEVELOPMENT OF RAPID DIE WEAR TEST METHOD FOR ASSESSMENT OF DIE LIFE AND PERFORMANCE IN STAMPING OF ADVANCED/ULTRA HIGH STRENGTH STEEL (A/UHSS) SHEET MATERIALS." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/2003.
Full textAbstract:
Automotive companies are actively pursuing to increase the use of high-strength-lightweight alloys such as aluminum, magnesium, and advanced/ultra high-strength steels (A/UHSS) in body panel and structural part applications to achieve fuel efficiency while satisfying several environmental and safety concerns. A/UHSS sheet materials with higher strength and crashworthiness capabilities, in comparison to mild steel alloys, are considered as a near-term (i.e., ~5 years) choice of material for body and structural components due to their relatively low cost when compared with other lightweight materials such as aluminum and magnesium. However, A/UHSS materials present an increased level of die wear and springback in stamping operations when compared to the currently used mild steel alloys due to their higher surface hardness and high yield strength levels. In order to prevent the excessive wear effect in stamping dies, various countermeasures have been proposed such as alternative coatings, modified surface enhancements in addition to the use of newer die materials including cast, cold work tool, and powder metallurgical tool steels. In this study, a new die wear test method was developed and tested to provide a cost-effective solution for evaluating various combinations of newly developed die materials, coatings and surfaces accurately and rapidly. A new slider type of test system was developed to replicate the actual stamping conditions including the contact pressure state, sliding velocity level and continuous and fresh contact pairs (blank-die surfaces). Several alternative die materials in coated or uncoated conditions were tested against different AHSS sheet blanks under varying load, sliding velocity circumstances. Prior to and after wear tests, several measurements and tribological examinations were performed to obtain a quantified performance evaluation using commonly adapted wear models. Analyses showed that (1) the rapid wear method is feasible and results in reasonable wear assessments, (2) uncoated die materials are prone to expose severe form wear (galling, scoring, etc.) problems; (3) coated samples are unlikely to experience such excessive wear problems, as expected; (4) almost all of the the recently developed die materials (DC 53, Vancron 40, Vanadis 4) performed better when compared to conventional tool steel material AISI D2, and (5) in terms of coating type, die materials coated with thermal diffusion (TD) and chemical vapor deposition (CVD) coatings performed relatively better compared to other tested coating types; (6) It was seen that wear resistance correlated with substrate hardness.
5
Defaisse, Clément. "Étude de la rupture ductile d'un acier à très haute résistance pour des applications aéronautiques." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM010/document.
Full textAbstract:
Les pièces des structures aéronautiques telles que les arbres des turboréacteurs, les roues, les freins ou les trains d’atterrissage sont fabriquées avec des aciers à très haute résistance. Leur structure martensitique, renforcée par des précipités de taille inférieure au micromètre, confère à ces aciers une excellente résistance : leur limite d'élasticité peut dépasser les 1900 MPa et leur résistance mécanique atteindre les 2300 MPa. Ces matériaux sont choisis pour ces excellentes propriétés mécaniques sur la base de leur comportement en traction. Toutefois, leur déformation à striction (maximum de la charge) est de quelques pourcents seulement. Les méthodes de dimensionnement sous chargement critique actuelles considèrent qu’aucun point de la structure ne doit être soumis à une déformation supérieure à la déformation à striction. Ce type d’approche est ici très conservatrice puisque les aciers THR continuent de se déformer plastiquement, ceci jusqu’à plusieurs dizaines de pourcent après le début de la striction. L’objet de ces travaux est de définir un modèle d’amorçage de la rupture applicable au dimensionnement de ces structures pour un acier type : le ML340. Ce matériau est actuellement utilisé dans les arbres de turboréacteur LEAP.Le comportement élasto-plastique du matériau a été étudié grâce à des essais menés sur différents types d’éprouvettes : tractions lisses, axisymétriques entaillées, déformation plane, plates entaillées, traction-torsion. Un modèle simple de von Mises à écrouissage isotrope permet de reproduire l’ensemble de la base. Ce modèle est ajusté sur les essais de traction pour lesquels un suivi optique de la variation du diamètre minium a été mis en place. La loi d’ ́écrouissage est ensuite ajustée en prenant en compte à la fois l'élongation et la variation du diamètre. On montre en particulier que l'extrapolation du comportement, méthode consistant à prolonger les données obtenues avant l'apparition de la striction, peut conduire à une mauvaise prédiction du comportement des éprouvettes.La base expérimentale a également été employée pour étudier l’amorçage de la rupture. L’observation des faciès montre un mode de rupture ductile avec des cupules fines. Cependant, l'initiation est brutale pour tous les essais et le développement de l’endommagement en volume reste très limité, voire nul. Ces constatations conduisent à proposer l’emploi d’un critère d’amorçage découplé : ce modèle fait intervenir la triaxialité des contraintes et le paramètre de Lode. Cette double dépendance est nécessaire pour bien décrire la rupture sur toute la base expérimentale. L’identification des paramètres du modèle se base sur l'évaluation des champs mécaniques à partir des simulations élasto-plastiques par éléments finis représentant les essais. Le modèle est également capable de prédire les emplacements des points d’amorçages observés, ces informations peuvent être utilisées pour ajuster plus finement le modèleAeronautical structures such as jet engines shafts, wheels, brakes or landing gears are made of Ultra High Strenth Steels (UHSS). Due to their hard martensitic matrix reinforced with second phase particles, such steels exhibit extreme mechanical resistance, their yield strength can overcome 1900 MPa and their ultimate tensile strength can reach 2300 MPa. Such materials are selected based on their tensile properties, however strain at necking (maximum load) is only few percent. Conventional certified design methods assume that failure occurs when a given point of the structure reaches this strain. Regarding UHSS this approach is very conservative; those materials are still able to bear large strains after necking start. The aim of this work is to define a failure initiation model able to predict ductile failure of such structures for extremes loadings. The ML340 steel, material of LEAP jet-engine shafts, have been selected for this study.Elasto-plastic behavior is investigated with various mechanical tests. Uniaxial tensile test were performed on round bars specimens, either smooth or notch, and flat specimens, either u notched or plane strain. Traction/torsion and compression/torsion biaxial tests were performed on tubes specimens. A simple isotropic von Mises plasticity model was found sufficient to describe mechanical behavior of this experimental database. This model was calibrated based on round smooth tensile tests, a longitudinal extensometer and a non contact method, measuring diameter reduction, were used in order to monitor strains. Hardening law was adjust with both sets of data using a reverse method, hence material striction is take into account during the identification. Identification method extrapolating plastic behavior based on tensile data measured before the striction begining is shown to overperdict plastic behavior.Failure initiation was also investigated through fracture tests. Every fractography display very fine dimples related to ductile fracture, however fracture apears to be very brutal and very few damage was observed underneath fracture surface. As a result an uncoupled fracture initiation model is proposed, damage indicator is driven by both stress triaxiality and a Lode parameter. This dual dependency is necessary in order to represent fracture for the whole database. Model parameters identification relies on the evaluation of local stress state for each test, this could be achieved with 3D elasto-plastic simulations. As a result fracture model was able to predict correct fracture initiation point positions observed on round tensile tests and flat u notch tests
6
Hartman, Trent J. "Friction Stir Spot Welding of Ultra-High Strength Steel." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3302.
Full textAbstract:
Friction stir spot welding (FSSW) is quickly becoming a method of interest for welding of high strength steel (HSS) and ultra high strength steel (UHSS). FSSW has been shown to produce high quality welds in these materials, without the drawbacks associated with fusion welding. Tool grade for polycrystalline cubic boron nitride (PCBN) tools has a significant impact on wear resistance, weld quality, and tool failure in FSSW of DP 980 steel sheet. More specifically, for a nominal composition of 90% CBN, the grain size has a significant impact on the wear resistance of the tool. A-type tools performed the best, of the three grades that were tested in this work, because the grain size of this grade was the finest, measuring from 3-6 microns. The effect of fine grain size was less adhesion of DP 980 on the tool surface over time, less abrasive wear, and better lap shear fracture loads of the welds that were produced, compared to the other grades. This is explained by less exposure of the binder phase to wear by both adhesion and abrasion during welding of DP 980. A-type tools were the most consistent in both the number of welds per tool, and the number of welds that reached acceptable lap shear fracture loads. B-type tools, with a bimodal grain size distribution (grain size of 4 – 40 microns) did a little bit better than C-type tools (grain size of 12-15 microns) in terms of wear, but neither of them were able to achieve consistent acceptable lap shear fracture load values after the first 200 welds. In fact only one out of five C-type tools was able to produce acceptable lap shear fracture loads after the first 100 welds.
7
Jahn, Axel. "Umformbarkeit laserinduktionsgeschweißter Strukturen aus höherfesten Stahlfeinblechen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-73795.
Full textAbstract:
Konventionelles Laserstrahlschweißen von Halbzeugen aus höherfesten Stahlfeinblechen führt zum drastischen Verlust an Umformbarkeit im Schweißnahtbereich. Durch integrierte induktive Erwärmung können der Temperaturverlauf beim Schweißen modifiziert, die Verbindungseigenschaften beeinflusst und die Umformbarkeit verbessert werden. Die Zusammenhänge zwischen Prozessparametern und mechanischen Verbindungseigenschaften werden beschrieben und Anwendungspotenziale aufgezeigt.
8
Sederstrom, Jack H. "Spot Friction Welding of Ultra High-Strength Automotive Sheet Steel." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/842.
Full textAbstract:
Spot friction welding (SFW) was performed on ultra high strength steel (UHSS) steel sheet commonly used in automobile manufacturing. Alloys studied included DP780, DP780EG, DP980, and DF140T sheet steel of varying thickness from 1.2 mm to 1.4 mm. Welding was accomplished using a PCBN standard tool. Weld strengths were then compared to a proposed AWS standard. Initial hardness readings were taken in cross sectioned samples. Grain structure in a SFW is presented. Resistance spot welds were created in three steels. This study focuses on the strength of SFW joints as compared to traditional resistance spot welding (RSW) in welding like materials to one another. Cycle times of SFW were also evaluated and compared to production rate cycle times of RSW.
9
Jahn, Axel. "Umformbarkeit laserinduktionsgeschweißter Strukturen aus höherfesten Stahlfeinblechen." Doctoral thesis, Fraunhofer Institut für Werkstoff- und Strahltechnik, 2010. https://tud.qucosa.de/id/qucosa%3A25673.
Full textAbstract:
Konventionelles Laserstrahlschweißen von Halbzeugen aus höherfesten Stahlfeinblechen führt zum drastischen Verlust an Umformbarkeit im Schweißnahtbereich. Durch integrierte induktive Erwärmung können der Temperaturverlauf beim Schweißen modifiziert, die Verbindungseigenschaften beeinflusst und die Umformbarkeit verbessert werden. Die Zusammenhänge zwischen Prozessparametern und mechanischen Verbindungseigenschaften werden beschrieben und Anwendungspotenziale aufgezeigt.
10
Müller, Katrin Margarete. "Spätergebnisse nach tiefer Beinvenenthrombose Therapievergleich UHSK mit Heparin /." [S.l.] : [s.n.], 2001. http://archiv.ub.uni-marburg.de/diss/z2001/0294/.
Full text
11
Briceno-Gomez, Martha M. "Microstructural investigation of a rapidly solidified UHS steel." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418568.
Full text
12
Redemske, Richard Michael. "An electromagnetic measurement tool for UHS RFID diagnostics." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/37067.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 67-68).
This thesis presents the design and analysis of a radio frequency identification (RFID) passive UHF emulation tag designed to be used as an environment evaluation tool. The tag implements the Auto-ID Center/EPCglobal Generation 1 RFID passive UHF tag protocol, and it implements a power detector on the received UHF signals. The power detector enables the tag to operate as a Field Probe providing instantaneous power level feedback at its location. Power level feedback is provided visually through on-probe LEDs (light emitting diodes), audibly through an on-probe speaker, and electronically as part of the communication protocol between the Field Probe and the reader. Experimental results presented here as well as the use of the Field Probe in real-world installations by the project sponsors have already shown that the Field Probe is a valuable tool in the design and analysis of RFID system installations and gross product packaging design.
by Richard Michael Redemske.
M.Eng.
13
Batista, Danilo Gonçalves. "Investigação da deterioração de concretos de uhes por reações com os agregados." Universidade Federal de Goiás, 2013. http://repositorio.bc.ufg.br/tede/handle/tede/3089.
Full textAbstract:
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-18T15:26:45Z
No. of bitstreams: 2
Dissertação Danilo G Batista 2013_ Final.pdf: 14272139 bytes, checksum: 1046108060b4c8d18c18e82aa11daf9d (MD5)
license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-18T15:41:57Z (GMT) No. of bitstreams: 2 Dissertação Danilo G Batista 2013_ Final.pdf: 14272139 bytes, checksum: 1046108060b4c8d18c18e82aa11daf9d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5)
Made available in DSpace on 2014-09-18T15:41:57Z (GMT). No. of bitstreams: 2 Dissertação Danilo G Batista 2013_ Final.pdf: 14272139 bytes, checksum: 1046108060b4c8d18c18e82aa11daf9d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-21
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
A long time ago aggregate particles were considered inert but this concept is no longer adequate. Expansive reactions resulting from the oxidation of sulfide-bearing aggregates and the AAR are examples of potential chemical interactions that aggregates may experience in concrete, depending on the surrounding environment. This research is an investigation into concrete deterioration in Hydroelectric Power Plants (HPPs), focusing on aggregate reactions relating to attack by sulfates, due to oxidation of sulfide minerals, as well as to the alkali-aggregate reaction (AAR). One of the main purposes is to have a clearer understanding of the changes in sulfide minerals occurring in aggregates and verify their influence on concrete durability as well as check the conditions and characteristics that maximize or not the synergy of such pathology. Along with that, another purpose is to study the possibility of the AAR occurring in the same structures. To this end, an investigation of concrete structures extracted from five Brazilian hydroelectric plants, namely Corumbá HPP, Marechal Mascarenhas de Moraes HPP, Paulo Afonso II HPP, Paulo Afonso IV HPP and Moxotó HPP, was conducted. In addition to the concretes, a study of the rocky material and aggregates surrounding the plants that were of the same origin as the aggregates in the concretes was also performed. A thorough visual inspection was made in the field of some concrete structures selected from the HPPs , with the subsequent extraction of concrete cores in spots that were more prone to the incidence of some chemical reaction. The concrete core samples were initially inspected in the laboratory to check for possible visible anomalies on their surfaces, and were subsequently subjected to laboratory tests to determine the mechanical properties such as compressive strength and elasticity modulus. Chemical and microstructural analyses of the concrete were then carried out, in addition to the reconstitution of the mix design and determination of their pH. The concrete were also underwent internal inspections before the microstructural analyses, and the last were scanning electron microscopy with energy-dispersive X-ray spectrometry (EDS) and X-ray diffraction (XRD) in order to diagnose deterioration. Aggregates extracted from concrete cores along with the rocky material of the same origin were also subjected to chemical and mineralogical analyses. The concrete from Corumbá HPP was found to be sound, but in the concretes from the other HPPs it was proved the incidence of AAR and sulfate attack simultaneously, and in some cases, with evidences that the attack by sulfates results from the oxidation of sulfide minerals in the aggregates.
Durante muito tempo as partículas de agregados foram consideradas inertes; entretanto, atualmente esse conceito foi banido. Reações expansivas decorrente da oxidação de minerais sulfetos presentes em agregados e da reação álcali-agregado (RAA) são exemplos de interações químicas potenciais que os agregados podem experimentar quando presentes no concreto, dependendo do meio circundante. A presente pesquisa aborda a investigação de concretos de UHEs com foco na deterioração por reações com os agregados no que tange ao ataque por sulfatos, devido à oxidação de minerais sulfetos, bem como à RAA. Objetiva-se avançar no entendimento do fenômeno de alteração de minerais sulfetos presentes em agregados e verificar a sua influência sobre a durabilidade de concretos, além de verificar as condições e características que maximizam ou não a sinergia desta patologia. Conjuntamente, pretende-se também estudar, nas mesmas estruturas, a possibilidade de ocorrência da RAA. Para tanto, procedeu-se com uma investigação de concretos extraídos de estruturas pertencentes a cinco usinas hidrelétricas brasileiras, a saber: UHE Corumbá, UHE Marechal Mascarenhas de Moraes, UHE Paulo Afonso II, UHE Paulo Afonso IV e UHE Moxotó. Além dos concretos, procedeu-se também com um estudo do material rochoso e dos agregados do entorno das usinas, de mesma origem que os agregados dos concretos. Inicialmente foi realizada criteriosa inspeção visual em campo de algumas estruturas de concreto selecionadas das UHEs, com posterior extração de testemunhos em locais com maior propensão da incidência de alguma reação química. Os testemunhos de concreto foram inicialmente inspecionados em laboratório para a verificação de possíveis anomalias visíveis em suas superfícies, sendo posteriormente submetidos a ensaios laboratoriais para a determinação das propriedades mecânicas de resistência à compressão e módulo de elasticidade. Foram, na sequência, realizadas análises químicas e microestruturais dos concretos, além da reconstituição de traço e obtenção do pH. Os concretos também foram submetidos a inspeções internas antes das análises microestruturais, sendo estas últimas a microscopia eletrônica de varredura com espectrometria por energia dispersiva de raios X (EDS) e a difração de raios X (DRX), ambas com o objetivo de diagnosticar deterioração. Os agregados extraídos dos concretos juntamente com o material rochoso de mesma origem também foram submetidos a análises químicas e mineralógicas. Pelos resultados, verificou-se boa integridade dos concretos da UHE Corumbá, porém para as demais usinas, constatou-se nos concretos a incidência de RAA, além de ataque por sulfatos, tendo alguns dos concretos das demais usinas indícios de que o ataque por sulfatos é decorrente da oxidação de minerais sulfetos presentes nos agregados.
14
BATISTA, Thiago Roberto. "O uso do reservatório de UHEs para o transporte hidroviário: O caso de FURNAS." reponame:Repositório Institucional da UNIFEI, 2015. http://repositorio.unifei.edu.br:8080/xmlui/handle/123456789/159.
Full textAbstract:
Submitted by repositorio repositorio (repositorio@unifei.edu.br) on 2015-11-13T12:11:33Z
No. of bitstreams: 1
dissertacao_batista_2015.pdf: 8735890 bytes, checksum: f392eb60c4d1a6791a5f48e5dd605942 (MD5)Made available in DSpace on 2015-11-13T12:11:33Z (GMT). No. of bitstreams: 1 dissertacao_batista_2015.pdf: 8735890 bytes, checksum: f392eb60c4d1a6791a5f48e5dd605942 (MD5) Previous issue date: 2015-06
O Brasil dispõe de uma grande área para navegação nos reservatórios das usinas hidrelétricas, praticamente disseminada por todo o território nacional. Os critérios operativos dos reservatórios deveriam atender a interesses múltiplos, conforme estabelecido na lei 9.433 em seu artigo 20 e inciso II, porém o domínio histórico do setor elétrico sobre os reservatórios impôs que a operação destes atendesse quase que exclusivamente os interesses eletro energéticos. A proposta de uma hidrovia para o reservatório da hidrelétrica de FURNAS além de fortalecer o estabelecimento de um nível de referência que permita a garantia dos interesses múltiplos, proporciona ainda o desenvolvimento de setores econômicos até então considerados inviáveis em função do grande deslocamento rodoviário, além de melhorar capacidade de concentração de cargas, a minimização do consumo de combustível, ocasionando a não emissão de gases poluentes, a redução do trafego em rodovias, dentre outros. Para isto, essa dissertação de mestrado apresenta uma contribuição quanto a duas alternativas metodológicas de avaliação da viabilidade de utilização do modal hidroviário em reservatórios. O primeiro modelo trata de mercados existentes e o segundo para mercados potenciais. Estas alternativas são aplicadas para e reservatório de FURNAS e podem vir a serem indutoras de desenvolvimento futuro de novos sistemas de integração de transporte de carga para os pequenos produtores de insumos regionais.
15
Slavíková, Jana. "Návrh vzdělávacího programu pro pracovníky společnosti UHS JAKOS, a.s. při zavádění čárových kódů." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2016. http://www.nusl.cz/ntk/nusl-234814.
Full textAbstract:
This thesis deals with proposal for an education program for employees of UHS JAKOS, a.s. which implemented a new information system 3 year ago and because of this they are planning to implement a bar codes. The analysis was realized by questionnaire survey between the employees who will work with the bar codes. The thesis is divided into 3 sections. The first section is theoretical and describes an education as process of change during implementing the bar codes. Next is analysis section which describes a current situation in the company by questionnaire. At the end it focuses on proposal of education program which will get easy the implementing of code bars.
16
Mazzola, Giacomo. "Caratterizzazione microstrutturale e a fatica di acciai da utensili pallinati e intagliati." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15197/.
Full textAbstract:
Lo scopo del presente elaborato è valutare un eventuale effetto benefico della pallinatura sulla resistenza a fatica di due acciai prodotti per metallurgia delle polveri: il K890, prodotto da Böhler e l’ASP2005, prodotto da Erasteel. Quest’attività si inserisce in un progetto volto a valutare l’idoneità di tali acciai innovativi ad essere impiegati per la realizzazione di componenti motore di moto da corsa, quali alberi a camme, in sostituzione dell’acciaio da nitrurazione GKHW, prodotto da Aubert&Duval con processo ESR (Electro slag remelting). Lo studio è stato svolto a valle di una sperimentazione condotta su provini intagliati degli stessi acciai e ha previsto: prove di fatica a flessione rotante, prove di trazione, prove di durezza, misura di tensioni residue, analisi microstrutturali e frattografiche.
Sono stati testati provini in ASP2005, con durezza pari a 869 HV e in K890 di due diverse durezze, pari a 752 e 821 HV, tutti intagliati e pallinati. Entrambi i materiali hanno mostrato un effetto benefico della pallinatura sul comportamento a fatica; i risultati ottenuti sono stati impiegati al fine di valutare l’applicabilità di relazioni empiriche per la stima del coefficiente di concentrazione a fatica delle tensioni e della sensibilità all’intaglio di acciai ultra-alto resistenziali. È stato dimostrato che le relazioni tradizionali sovrastimano l’effetto dannoso dell’intaglio per questo tipo di acciaio nella condizione pallinata.
È stato, inoltre, condotto uno studio per la modellazione del comportamento a fatica di provini intagliati con un coefficiente di concentrazioni delle tensione Kt=3 e in un secondo momento si è tentato di estendere il modello anche a provini con un Kt compreso fra 1 e 3.
Queste analisi sperimentali sono precedute da un inquadramento generale delle funzioni e dei requisiti di un albero di distribuzione in ambito racing e da una trattazione circa i meccanismi di rottura per fatica in acciai ultra-alto resistenziali.
17
Ferreira, Artur Barbosa Bernardes. "Sistema de suporte à decisão contratual ótima de UHEs no mercado de energia elétrica utilizando gerenciamento de risco." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-20092012-080148/.
Full textAbstract:
O modelo de comercialização de energia elétrica operante no Brasil é fruto da reestruturação do Setor Elétrico Brasileiro (SEB), que se iniciou na década de 90. Este modelo atual, mais estruturado, impulsionou os investimentos privados no setor nos últimos anos, fazendo com que a comercialização de energia se tornasse algo de grande representatividade dentro do setor elétrico. Este modelo de comercialização como é hoje, dividido em dois ambientes, dinâmico e em constante evolução, é alvo de inúmeros investidores, principalmente no Ambiente de Contratação Livre (ACL) onde o número de agentes cresceu consideravelmente nos últimos anos, e gerou movimentações financeiras recordes. Associado a este crescimento expressivo, os riscos inerentes de mercado também se mostram relevantes e de fundamental necessidade de gerenciamento para o equilíbrio financeiro do investidor. Dessa forma, este trabalho propõe uma análise acerca da comercialização de energia no mercado brasileiro, quanto ao gerenciamento do risco por parte de um agente gerador operando no ACL, através da implementação de um otimizador contratual que ajude na tomada de decisão de quanta energia destinar a cada contrato, de modo a maximizar a receita do agente a um risco controlável.The present marketing model of electric power in Brazil is the result of the restructuring of the Brazilian Electric Sector (BES), which began in the 90s. This current model, somewhat more structured, stimulated private investment in the sector in recent years; this way the electric power´s market acquired substantial representation within the electricity sector. The current market model, having two different commercial environments, dynamic and constantly evolving, has been attracting many investors, especially in the Free Contracting Environment (FCE) where the number of agents has grown considerably in recent years, and generated record number of financial transactions. Associated with this significant growth, the inherent risks in this market are effectively of concern and need being managed to ensure the financial balance of the investor. Therefore, this work proposes an analysis about the energy trading in the Brazilian market, as to the management of risk by an agent generator operating in the FCE, through the implementation of a contract optimizer that helps in making decisions on how construct a contract portfolio in order to maximizes the agent revenue under a controllable risk.
18
Batista, Gabriel de Avila. "O meio biótico nos termos de referência de estudos de impacto ambiental de UHEs brasileiras - a raiz dos problemas." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8908.
Full textAbstract:
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-09-24T14:29:40Z
No. of bitstreams: 2
Dissertação - Gabriel de Avila Batista - 2018.pdf: 2567575 bytes, checksum: 6cfc976ffbec0e51a1f601f6d594c3c0 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-09-24T15:19:02Z (GMT) No. of bitstreams: 2 Dissertação - Gabriel de Avila Batista - 2018.pdf: 2567575 bytes, checksum: 6cfc976ffbec0e51a1f601f6d594c3c0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Made available in DSpace on 2018-09-24T15:19:02Z (GMT). No. of bitstreams: 2 Dissertação - Gabriel de Avila Batista - 2018.pdf: 2567575 bytes, checksum: 6cfc976ffbec0e51a1f601f6d594c3c0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-07-09
The Brazilian federal government assumes the imminence of an energy crisis. Thus, hydroelectric projects appear as a preventive response to the reduction of energy resources and to eventual socioeconomic instability arising from this problem. Therefore, it becomes pertinent to several sectors the discussion about the socioeconomic, physical and biotic aspects that are affected by the implantation of hydroelectric dams. Despite the legal, technical and scientific aspects of the brazilian Environmental Licensing (EL) process, it is part of an administrative process, and comply with protocols defined in Reference Terms (RT). Thereby their stages, including the Environmental Impact Assessment (EIA), must conform to the proposal of these documents to enable the flow of the EL process. The literature indicates shortcomings in environmental licensing processes related to EIAs, with the nature of these gaps varying from administrative, legal, technical, and scientific methods. Still in this plea, the literature also points out problems regarding the biotic aspects of environmental impact assessment. These errors lead to environmental impacts that are difficult to mitigate, since they were not predicted or evaluated during the studies. Observing these premises and considering the RT as the base of the methods used in these studies, it is possible to suppose that this document is one of the problems origins observed in the subsequent phases. Are the guidelines for the biotic environment in RTs in line with what is proposed by science? The analyzes in this study demonstrate that the scientific quality of the biotic environment protocols is low. It is known why sample – as this question answers a legal requirement too –, but it is not known the best sample targets neither the adequate way to sample, which may lead to irreversible impacts. The prognosis is disappointing, with an increase of 0.53% in quality per year, considering 1988 as the starting year, it will still take 158 years to reach the ideal.
O governo federal brasileiro assume a iminência de uma crise de energia. Assim, os projetos hidrelétricos aparecem como uma resposta preventiva à redução de recursos energéticos e à eventual instabilidade socioeconômica decorrente desse problema. Portanto, torna-se pertinente em vários setores a discussão sobre os aspectos socioeconômicos, físicos e bióticos que são afetados pela implantação de hidrelétricas. Apesar dos aspectos legais, técnicos e científicos do processo de Licenciamento Ambiental (LA) brasileiro, faz parte de um processo administrativo e cumpre os protocolos definidos nos Termos de Referência (TR). Assim, suas etapas, incluindo a Avaliação de Impacto Ambiental (AIA), devem estar em conformidade com a proposta desses documentos para permitir o fluxo do processo de LA. A literatura indica deficiências nos processos de licenciamento ambiental relacionados a AIA, com a natureza dessas lacunas variando de métodos administrativos, legais, técnicos e científicos. Nessa razão, a literatura também aponta problemas relacionados aos aspectos bióticos da avaliação de impacto ambiental. Esses problemas levam a impactos ambientais que são difíceis de mitigar, já que não foram previstos ou avaliados durante os estudos. Observando essas premissas e considerando o TR como a base dos métodos utilizados nesses estudos, é possível supor que este documento é uma das origens dos problemas observados nas fases subsequentes. As diretrizes para o ambiente biótico em TRs estão de acordo com o que é proposto pela ciência? As análises nesse estudo demonstram que a qualidade científica dos protocolos para o meio biótico nesses documentos é baixa. Sabe-se porque amostrar – já que essa pergunta responde também a um requisito legal –, mas não são conhecidos os alvos ideais de amostragem nem a forma mais adequada de amostrar, o que possibilita impactos ambientais irreversíveis. O prognóstico é desanimador, com um incremento de 0,53% de qualidade ao ano, considerando 1988 como ano de partida, ainda levaremos 158 anos para atingir o ideal.
19
George, Magalhães Moreno Marcos. "Modelagem numérica da elevação de subpressão no Dique A da Usina Hidroelétrica de Sobradinho (UHS)." Universidade Federal de Pernambuco, 2005. https://repositorio.ufpe.br/handle/123456789/5736.
Full textAbstract:
Made available in DSpace on 2014-06-12T17:41:36Z (GMT). No. of bitstreams: 2
arquivo6428_1.pdf: 2604981 bytes, checksum: 874810cfd32cdcf003424e4187f4bf1c (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2005Conselho Nacional de Desenvolvimento Científico e Tecnológico
Neste trabalho estudou-se a simulação da elevação de subpressão no dique A da Usina Hidroelétrica de Sobradinho (UHS), de propriedade da CHESF (Companhia Hidroelétrica do São Francisco). Trata-se de um caso de engenharia bastante ilustrativo da importância da instrumentação e acompanhamento de obras de terra, elementos fundamentais e indispensáveis para a segurança dessas obras ao longo de sua vida útil. Para tanto, foram realizadas simulações numéricas no regime estacionário em três situações (casos) diferentes ao longo da vida útil do dique. No primeiro caso, foi considerada uma análise do comportamento do dique funcionando como previsto no projeto. No segundo caso, foi considerado na simulação numérica o dique funcionando com o filtro de areia horizontal colmatado, sendo esta a principal causa da elevação da subpressão no dique A da UHS. No terceiro caso, além do filtro de areia colmatado, considerou-se a implantação de um sistema de poços de alívio no pé do talude de jusante. Esta ação corretiva foi responsável pela diminuição das poro-pressões a níveis seguros fixados no projeto. Outros possíveis mecanismos causadores do aumento de subpressão no dique (aumento gradativo da permeabilidade da fundação) assim como outras ações corretivas, tomadas pela CHESF (execução de um tapete impermeável à montante do dique), foram verificadas através da modelagem numérica porém demonstraramter menor impacto com relação ao comportamento hidráulico do dique em comparação aos três casos descritos anteriormente. Foi realizado também um estudo teórico sobre a possibilidade de ocorrência do fenômeno do sinfonamento capilar, que pode vir a ocorrer em barragens de terra, dando destaque para a importância da obtenção da curva de retenção para os materiais envolvidos em sua construção. A ferramenta de trabalho utilizada na modelagem numérica foi o programa computacional CODE_BRIGHT, que é baseado no método dos elementos finitos. Este programa representou de maneira coerente à elevação de subpressão observada nos piezômetros instalados no dique A, mostrando a importância da utilização da modelagem numérica no acompanhamento desse tipo de obra, assim como pode ser uma ferramenta de otimização de projetos de engenharia e de previsão futura do comportamento das barragens de terra, auxiliando na localização da instrumentação da barragem e sua fundação em zonas onde possam vir a ocorrer as máximas poro-pressões e fluxos de água
20
Sefidpour, Sepehr. "Pilot Protection Based on Directional Detection." Thesis, KTH, Elektriska energisystem, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119249.
Full textAbstract:
Nowadays two main types of protection schemes widely used in protection of transmission lines are: distance protection and differential protection schemes. However, it has been noticed from industrial practice that the distance protection scheme used today generally is limited in tripping speed and selectivity. Also differential protection scheme is influenced by the time synchronization of samples in both relays installed at transmission line terminals. On the other hand, among various pilot protection schemes for protection of Extra High Voltage (EHV) / Ultra High Voltage (UHV) transmission lines, the schemes which use communication link only for exchange of local decision making about faults’ status are not affected by time synchronization. This master thesis is dealing with the issue of developing reliable and fast fault detection scheme for protection of EHV/UHV transmission lines which is a requirement in modern power systems. The protection algorithm proposed in this thesis is based on the detection and analysis of traveling waves on transmission lines at inception of the faults. This algorithm relies on directional comparison between initial arrivals of traveling waves at each end of the protected line. This will determine whether or not a fault is inside the protected zone. In addition to, based on high voltage transmission network protection requirements proper phase selection algorithm is developed to handle single- phase tripping. Finally, by simulations carried out in PSCAD environment practical design considerations for implementing the new developed protection algorithm in a numerical relay unit is investigated. The results of simulation show that the proposed pilot protection scheme solves several issues encountered by using the conventional schemes and provide reliable and high speed protection for transmission lines.
21
Agrawal, Pramod. "An investigation into a new approach to UHS protection of EHV transmission lines based on detection of fault generated noise." Thesis, City University London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328403.
Full text
22
Rubio, Mauricio Fava. "Gênese e dinâmica de erosões em margens de reservatórios. Pesquisa e desenvolvimento no estudo de caso nas UHEs Chavantes e Rosana (rio Paranapanema, SP/PR)." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-29062015-155336/.
Full textAbstract:
Esta pesquisa foi desenvolvida a partir de um Projeto de P&D do setor elétrico brasileiro. Há duas abordagens, uma relacionada ao desenvolvimento teórico-metodológico sobre o conhecimento acerca das erosões marginais e outra relativa à transformação deste desenvolvimento teórico-metodológico em discussões sobre a melhoria da gestão desta problemática pelo setor elétrico e pela sociedade brasileira. Quanto ao desenvolvimento teórico-metodológico acerca das erosões marginais, realizou-se uma série de procedimentos cujos resultados principais foram (i) a discussão de um novo modelo conceitual sobre a velocidade de desenvolvimento das erosões ao longo da vida dos reservatórios, (ii) a revisão bibliográfica acerca das condicionantes envolvidas na gênese e no desenvolvimento dos processos erosivos e (iii) a geração de um conjunto de dados e informações sobre as erosões monitorados que possibilitaram novas discussões sobre as condicionantes citadas no item anterior. As análises sobre a gênese das erosões foi conduzida a partir da comparação entre as margens dos reservatórios com instabilidade morfodinâmica e aquelas que apresentam estabilidade morfodinâmica; enquanto a análise sobre o desnvolvimento das erosões foi realizada a partir da comparação de dados e informações acerca de processos erosivos já instaurados, monitorados ao londo de determinado período de tempo. Por fim, a relação entre este desenvolvimento teórico-metodológico e a gestão desta problemática pelo setor elétrico brasileiro foi abordada por meio da (i) proposição de um método de classificação da tipologia das erosões marginais; (ii) proposição de um sistema de classificação dos níveis de criticidade das erosões; e (iii) das análises e discussões sobre questões relacionadas às erosões marginais, visando propor medidas e ações para mitigação deste impacto desde a implantação até a operação dos empreendimentos hidrelétricos.This research was developed along with aP&D project of the brazilian eletric sector. It approaches two perspectives This research approach two perspectives, one related to the theoretical and methodological development of the knowledge of bank erosions and another one on development in discussion about improving the management of this problem by the electric sector and Brazilian society. In relation to the theoretical and methodological development of marginal erosions, I conducted a series of procedures whose main results were (i) a discussion of a new conceptual model on the speed of development of erosions over the life of the reservoirs, (ii) literature review about the constraints involved in the genesis and development of erosion processes and (iii) the generation of a set of data and information about the monitored erosions which enabled further discussion on the constraints mentioned in the previous item. The analysis of the genesis of the erosions was conducted based on the comparison between the margins of reservoirs with morphodynamic instability and those which have morphodynamic stability; while for the analysis of the development of erosions was done by comparing data and information about erosion processes already in place, tracked by a certain period of time. Finally, the relationship between this theoretical and methodological development and the management of this problem by the Brazilian electric sector is given by (i) proposing a method of classification of the type of marginal erosions; (ii) proposing a classification system for levels of criticality of erosions; and (iii) analyzing and discussing issues related to marginal erosions, aiming to propose measures and actions to mitigate this impact since implementation to operation of hydroelectric projects.
23
HOLANDA, Patrícia da Silva. "Avaliação de potencial hidrocinético à jusante de centrais hidrelétricas." Universidade Federal do Pará, 2017. http://repositorio.ufpa.br/jspui/handle/2011/10515.
Full textAbstract:
Submitted by Luciclea Silva (luci@ufpa.br) on 2019-01-09T15:12:05Z
No. of bitstreams: 2
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Tese_Avaliacaopotencialhidrocinetico.pdf: 8351249 bytes, checksum: 542dae2d7946a6040cc94eb50f120133 (MD5)Approved for entry into archive by Luciclea Silva (luci@ufpa.br) on 2019-01-09T15:15:05Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_Avaliacaopotencialhidrocinetico.pdf: 8351249 bytes, checksum: 542dae2d7946a6040cc94eb50f120133 (MD5)
Made available in DSpace on 2019-01-09T15:15:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_Avaliacaopotencialhidrocinetico.pdf: 8351249 bytes, checksum: 542dae2d7946a6040cc94eb50f120133 (MD5) Previous issue date: 2017-12
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
É possível maximizar o rendimento de empreendimentos hidrelétricos, aproveitando a energia remanescente a jusante de barragens a partir da instalação de turbinas hidrocinéticas. Nesse contexto, são apresentados dois estudos de casos de usinas hidrelétricas, um de grande porte Tucuruí, construída no rio Tocantins, na Amazônia, e outro de médio porte Bariri no rio Tietê, no Sudeste do Brasil. Nos projetos de centrais hidrocinéticas, é fundamental o dimensionamento do diâmetro do rotor e da velocidade da água, os quais dependem, respectivamente, das profundidades e velocidades dos rios. Assim, o modelo de Saint-Venant foi aplicado as regiões de estudos. A calibração do modelo foi realizada através de uma regressão linear entre as vazões medidas e simuladas para ambos, resultando em uma correlação de 0,99. A validação foi realizada para um ponto do rio Tocantins com velocidades medidas via ADCP. As velocidades medidas são comparáveis às velocidades simuladas pelo modelo. Assim, foi gerada uma curva de potência entre as vazões medidas e as velocidades simuladas para o ponto que teve suas velocidades validadas, obtendo-se uma correlação de 0,96. Essa mesma curva foi utilizada para estimativas de velocidade, calculando-se a densidade energética e definindo-se a velocidade de projeto para UHEs Tucuruí igual a 2,35 m/s e Bariri 2,25 m/s. Com a velocidade de projeto definida, foram selecionados 10 pontos UHE Tucuruí 1 ponto UHE Bariri para a implantação das turbinas hidrocinéticas. As velocidades desses pontos foram determinadas com o mesmo método usado para a validação das velocidades. Os pontos foram selecionados com base no canal do reservatório de jusante Tucuruí e no final da bacia de dissipação Bariri , o qual possui as maiores profundidades e velocidades sendo convenientes para uma maior geração de energia. Considerando a profundidade do rios e a tecnologia disponível para a sua fabricação, definiu-se para o estudo de grande porte o diâmetro do rotor em 10 m e para o de médio porte 2,1 m. Com a velocidade de projeto definida, o projeto do rotor foi realizado pela metodologia BEM (Blade Element Momentum), permitindo a definição de uma curva de potência instalada da turbina em função da velocidade do rio. Em termos de energia gerada as 10 turbinas podem gerar 2,04 GWh/ano. Esses números demonstram o real potencial do aproveitamento da energia remanescente de usinas hidrelétricas.
The maximization of the performance of hydropower projects by taking advantage of the remaining energy downstream of dams via the installation of hydrokinetic turbines is feasible. In this context, two case studies of the hydroelectric power plants are presented, one of large Tucuruí in the Tocatins river, Amazonia, and another of medium size Bariri in the Tietê river, in the Southeast of Brazil.In central hydrokinetic projects, the design of the rotor diameter and velocity of the water are fundamental and depend on the depth and velocity of the river, respectively. Thus, the Saint-Venant model has been applied to these areas of studies. The calibration of the model was performed by linear regression of the measured and simulated flow rates for both, resulting in a correlation of 0.99. Validation was performed for a point on the Tocantins river using velocities measured with an acoustic Doppler current profiler (ADCP). The measured velocities are comparable to the velocities simulated by the model. Thus, a power curve was generated for the measured flow rates and the simulated velocities for the point at which the velocities were validated, thus obtaining a correlation of 0.96. This same curve was used for estimates of velocity, calculation of the energy density, and defining a design velocity for Tucuruí HPP equal to 2.35 m/s and Bariri 2.25 m/s. After the design was velocity defined, 10 points were selected Tucuruí and 1 point Bariri for the location of hydrokinetic turbines. The velocities of these points were determined with the same method used for the validation of the velocities. The points were selected based on the channel downstream of the reservoir and at the end of the Bariri dissipation basin, with the largest depth and velocity, which are characteristics favorable for greater power generation. Considering the rivers depth and available manufacturing technology, the rotor diameter was defined for the large study in 10 m and for the medium 2.1 m. After the design velocity was defined, the rotor design was implemented using the blade element method (BEM Blade Element Momentum), allowing for the definition of an installed power curve of the turbine as a function of the river velocity. In terms of generated energy, the 10 turbines can generate 2.04 GWh/year. These numbers demonstrate the potential for utilizing the remaining energy of hydroelectric plants.
24
Baglieri, Giulia. "Caratterizzazione a fatica con intaglio di acciai innovativi ultra-alto resistenziali." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Find full textAbstract:
Lo scopo della presente ricerca è valutare l’idoneità dell’acciaio da utensili innovativo K890, prodotto da Böhler con metallurgia delle polveri, ad essere impiegato per la realizzazione di componenti motore di moto da corsa, quali alberi a camme e a gomiti, in sostituzione dell’acciaio da nitrurazione GKHW, prodotto da Aubert&Duval con processo ESR (Electro Slag Remelting). Lo studio è stato condotto a valle di una precedente sperimentazione condotta su provini non intagliati ed ha previsto l'esecuzione di prove di trazione e prove di fatica a flessione rotante con intaglio oltre a prove di durezza ed analisi microstrutturali e frattografiche.
Sono stati testati due lotti di acciaio K890, aventi durezza di 752 e 821 HV rispettivamente. Durante i test di fatica il lotto in K890 a durezza maggiore ha mostrato un limite di fatica con intaglio superiore al GKHW nitrurato. I risultati ottenuti sui due lotti di K890 sono stati impiegati per valutare l’applicabilità di relazioni empiriche per la stima del coefficiente di concentrazione a fatica delle tensioni ad acciai ultra-alto resistenziali. E’ emerso che le relazioni più tradizionali sovrastimano l’effetto dell’intaglio per questa tipologia di acciaio. A conclusione dello studio, considerando l'esito delle stesse prove condotte sull'acciaio GKHW nitrurato attualmente in uso, si può affermare che l'acciaio K890 è un possibile candidato per la produzione di alberi in ambito racing.
La disamina dei risultati sperimentali è preceduta da tre capitoli incentrati su un inquadramento teorico, derivanti da ricerche bibliografiche: il primo riporta un’introduzione al funzionamento ed alle caratteristiche degli alberi a camme e a gomiti; il secondo è relativo alle proprietà degli acciai da utensili tradizionali ed innovativi; infine il terzo riguarda una trattazione sul danneggiamento da fatica, con particolare riguardo all’effetto dell’intaglio ed alle caratteristiche del fenomeno negli acciai ultra-alto resistenziali.
25
Pereira, Cíntia Marques. "Challenges in flex binning ultra high resolution seismic reflection data." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/21923.
Full textAbstract:
Mestrado em Engenharia GeológicaOs dados sísmicos 3D podem conter “lacunas” de cobertura devido a diversos problemas operacionais. As “lacunas” em dados 3D podem causar impactos adversos em várias etapas do processamento de dados, tais como na análise de velocidade, atenuação dos múltiplos, “stack” e migração. O Flex Binning é um método expediente para resolver este problema. O método Flex Binning permite que cada bin contenha mais traços, aumentando o tamanho efectivo de cada bin e incluindo traços dos bins vizinhos. O desafio é aplicar o Flex Binning a um número muito grande de traços que excedem as soluções actuais de design de software e capacidade de hardware. Vários testes foram realizados no software Seismic Processing Workshop (SPW). Durante os vários testes realizados, foi possível detectar e resolver problemas de código e “bugs” de software tais como, por exemplo, a incapacidade de aplicar uma grelha ao conjunto de dados e deixar traços fora da grelha. A questão da indexação foi outro problema detectado, que se resolveu por uma mudança de design do software no fluxo de processamento CMP Binning. A realização de vários testes nas diversas versões do SPW permitiu avanços na implementação do Flex Binning para conjuntos de dados de elevadas dimensões, nomeadamente a execução do fluxo CMP Binning com sucesso num conjunto de dados com 751GB. No fluxo de processamento CMP Binning, antes destes testes só era possível aplicar o Flex Binning corretamente a um conjunto de dados com aproximadamente 30 GB de tamanho.
3D seismic reflection data may contain coverage gaps due to operational problems. The gaps in 3D data can cause adverse impacts in several steps of the data processing such as velocity analysis, multiple attenuation, stacking and migration. Flex Binning is an expedient method to solve these gaps. The Flex Binning method allows each bin to contain more traces, by increasing the effective size of each bin and thereby include traces which also fall into neighboring bins. The challenge is to apply Flex Binning to very large number of traces exceeding current software design solutions and hardware capability. Several tests were performed with the Seismic Processing Workshop (SPW) software. During several tests, coding problems and bugs were detected and corrected, such as the inability to apply a grid to the dataset and leave traces out of the grid. Also, proper indexing was also solved by a change of software design in CMP Binning code. Beta testing on SPW allowed advances in the implementation of Flex Binning to large inputs, namely the execution of the CMP Binning flow successfully to a dataset with 751GB. The CMP Binning step before the tests could only Flex Binning effectively to an input with a size of approximately 30 GB.
26
Pons, Aliaga David. "ESTUDIO NUMÉRICO DE LA CAPACIDAD PORTANTE DE COLUMNAS MIXTAS CON DOBLE TUBO RELLENAS DE HORMIGON." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/62209.
Full textAbstract:
[EN] Concrete-filled steel tubular columns composed of double-tube sections are a recent development. This type of sections are the result of applying a technique used in the construction of immersed tunnels, by forming a sandwich composite section made up of steel-concrete-steel.
Apart from the own advantages of concrete-filled steel tubular (CFST) columns, double-tube columns present other additional advantages which make them of great interest for designers and engineers, such as: reduced weight, higher ductility, improved energy absorption and, above all, an enhanced fire resistance. In turn, the improvements in the manufacturing technique of high strength concrete makes their use in double-tube columns create the suitable synergy for the design of slender structural members.
Nevertheless, the fast evolution and development of composite construction has led to a situation where the current design guidance cannot provide updated analytical expressions and recommendations. Give this situation, and due to the innovative nature of this configuration, as well as the complexity of experimental testing, few experimental and analytical works can be found on this typology of columns.
This makes the numerical investigation of concrete-filled double-tube columns interesting from the scientific point of view.
The mechanical behaviour of concrete-filled double-tube columns is studied in this thesis through a realistic three-dimensional finite element model. The values adopted for the variables of the model are the result of a comprehensive sensitivity analysis. The accuracy of the numerical model is verified against experimental tests and, once the numerical model is validated, an extensive parametric study is developed, with the aim of studying the influence of the main factors which affect the mechanical response of this columns and being able to provide design recommendations. With this information, a comparative study is carried out with the results of the application of the current calculation method for composite columns in Eurocode 4-Part 1.1, in order to evaluate the validity of the method for double-tube columns subjected to axial compression and combined compression and uniaxial bending, infilled with ultra-high strength concrete.
The scope of this thesis is limited to slender circular double-tube columns filled with normal and ultra-high strength concrete subjected to monotonic concentric or eccentric axial load of uniform bending moment.[ES] Las columnas tubulares de acero rellenas de hormigón compuestas de una sección de doble tubo son de reciente creación. Son el resultado de aplicar la técnica utilizada en la construcción de túneles sumergidos, de construir una sección compuesta tipo sándwich, a base de acero-hormigón-acero. Además de las ventajas propias de las columnas tubulares de acero rellenas de hormigón (CFST), las columnas de doble tubo poseen otras ventajas adicionales que las hace muy interesantes para proyectistas e ingenieros como son, por ejemplo: menor peso, mayor ductilidad, mayor absorción de energía, y sobretodo, mejor resistencia a fuego. Por otra parte, la mejora de la técnica de fabricación de hormigones de altas resistencias hace que su utilización en columnas de doble tubo produzca una sinergia idónea para diseñar elementos estructurales esbeltos. Sin embargo, la rápida evolución y desarrollo de la construcción mixta hace que las normas actuales no tengan las expresiones analíticas ni las recomendaciones de diseño actualizadas. Debido a ello y por la relativa solución innovadora de esta configuración, así como la complejidad de realizar ensayos experimentales, existen pocos trabajos experimentales y estudios analíticos acerca de esta tipología de columnas. Es por esto que el estudio numérico de columnas de doble tubo rellenas de hormigón sea, desde el punto de vista científico, interesante. El comportamiento mecánico de columnas de doble tubo rellenas de hormigón se estudia en esta tesis a través de un modelo realista tridimensional de elementos finitos. Los valores adoptados de las variables del modelo son el resultado de un amplio análisis de sensibilidad. La precisión del modelo numérico se verifica con ensayos experimentales y, una vez se dispone de un modelo validado, se desarrolla un extenso estudio paramétrico con el fin de evaluar la influencia de los principales factores que afectan la respuesta mecánica de las mismas y poder establecer recomendaciones de diseño. Con esa información, se realiza una comparativa con los resultados de aplicar el método de cálculo de columnas mixtas del Eurocódigo 4 - Parte 1.1, con el propósito de evaluar la validez del método en columnas de doble tubo comprimidas y flexo-comprimidas rellenas de hormigón de ultra alta resistencia. El alcance de esta tesis queda limitado a columnas circulares esbeltas de doble tubo rellenas de hormigón de resistencia normal y ultra alta resistencia sometidas a carga monotónica centrada y excéntrica de momento uniforme.
[CAT] Les columnes tubulars d'acer emplenades de formigó compostes d'una secció de doble tub són de recent creació. Són el resultat d'aplicar la tècnica utilitzada en la construcció de túnels submergits, de construir una secció composta tipus sandvitx, a base d'acer-formigó-acer. A més dels avantatges propis de les columnes tubulars d'acer emplenades de formigó (CFST), les columnes de doble tub posseeixen altres avantatges addicionals que les fa molt interessants per a enginyers com són, per exemple: menor pes, major ductilitat, major absorció d'energia, i sobretot, millor resistència a foc. D'altra banda, la millora de la tècnica de fabricació de formigons d'altes resistències fa que la seva utilització en columnes de doble tub produïsca una sinergia idònia per dissenyar elements estructurals verticals esvelts. No obstant això, la ràpida evolució i desenvolupament de la construcció mixta fa que les normes actuals no tinguin les expressions analítiques ni les recomanacions de disseny actualitzades. Per aquest motiu i per la relativa solució innovadora d'aquesta configuració, així com la complexitat de realitzar assajos experimentals, existeixen pocs treballs experimentals i estudis analítics sobre aquesta tipologia de columnes. És per això que l'estudi numèric de columnes de doble tub farcides de formigó siga, des del punt de vista científic, interessant. El comportament mecànic de columnes de doble tub emplenades de formigó s'estudia en aquesta tesi mitjançant un model realista tridimensional d'elements finits. Els valors adoptats per a les variables del model són el resultat d'una extensa anàlisi de sensibilitat. La precisió del model numèric es verifica amb assajos experimentals i, una vegada es disposa d'un model validat, es desenvolupa un extens estudi paramètric amb la finalitat d'avaluar la influència dels principals factors que afecten la resposta mecànica de les columnes i poder establir recomanacions de disseny. Amb aquesta informació, es realitza una comparativa amb els resultats d'aplicar el mètode de càlcul de columnes mixtes del Eurocódigo 4-Part 1.1, amb el propòsit d'avaluar la validesa del mètode en columnes de doble tub comprimides i flexo-comprimides emplenades de formigó d'ultra alta resistència. L'abast d'aquesta tesi queda limitat a columnes circulars esveltes de doble tub emplenades de formigó normal i d'ultra alta resistència sotmeses a càrrega monotònica centrada i excèntrica amb moment uniforme.
Pons Aliaga, D. (2016). ESTUDIO NUMÉRICO DE LA CAPACIDAD PORTANTE DE COLUMNAS MIXTAS CON DOBLE TUBO RELLENAS DE HORMIGON [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62209
TESIS
27
Correia, Fábio Gonçalves. "Quality control of ultra high resolution seismic data acquisition in real-time." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22007.
Full textAbstract:
Mestrado em Engenharia GeológicaA aquisicção de grandes volumes de dados durante uma campanha sísmica exige, necessariamente, mais tempo para o controlo de qualidade (QC). No entanto, o tempo de QC não pode ser extendido devido a limitações do tempo de operação, tendo de ser feito mais rápido, o que pode comprometer a qualidade. A alternativa, alocar mais pessoas e recursos para QC e melhorar a eficiência, leva a aumentos de custo e à necessidade de maiores embarcações. Além disso, o QC tradicional requer tempo de análise após a aquisição, atrasando a desmobilização da embarcação, aumentando assim os custos da aquisição. A solução proposta passou pelo desenvolvimento de um QC automático em tempo real eficiente, testando a Comparação Espetral e o Atributo Razão Sinal-Ruído - ferramentas desenvolvidas no software SPW, usado para processamento de dados sísmicos. Usando este software foi testada a deteção e identificação de dados de fraca qualidade através das ferramentas de QC automáticas e os seus parâmetros ajustados para incluir pelo menos todos os maus registos encontrados manualmente. Foi também feita a deteção e identificação de vários problemas encontrados durante uma campanha de aquisição, tais como fortes ondulações e respetiva direção, o ruído de esteira provocado pelas hélices da embarcação e consequente Trouser’s Effect e mau funcionamento das fontes ou dos recetores. A deteção antecipada destes problemas pode permitir a sua resolução atempada, não comprometendo a aquisição dos dados. Foram feitos vários relatórios para descrever problemas encontrados durante os testes de versões beta do software SPW e os mesmos reportados à equipa da Parallel Geoscience, que atualizou o software de forma a preencher os requisitos necessários ao bom funcionamento do QC em tempo real. Estas atualizações permitiram o correto mapeamento dos headers dos ficheiros, otimização da velocidade de análise das ferramentas automáticas e correção de erros em processamento dos dados em multi-thread, para evitar atrasos entre o QC em tempo real e a aquisição dos dados, adaptação das ferramentas à leitura de um número variável de assinaturas das fontes, otimização dos limites de memória gráfica e correção de valores anómalos de semelhança espetral. Algumas atualizações foram feitas através da simulação da aquisição de dados na empresa, de forma a efetuar alguns ajustes e posteriormente serem feitos testes numa campanha futura. A parametrização destas ferramentas foi alcançada, assegurando-se assim a correta deteção automática dos vários problemas encontrados durante a campanha de aquisição usada para os testes, o que levará à redução do tempo gasto na fase de QC a bordo e ao aumento da sua eficácia.
The acquisition of larger volumes of seismic data during a survey requires, necessarily, more time for quality control (QC). Despite this, QC cannot be extended due operational time constraints and must be done faster, compromising its efficiency and consequently the data quality. The alternative, to allocate more people and resources for QC to improve efficiency, leads to prohibitive higher costs and larger vessel requirements. Therefore, traditional QC methods for large data require extended standby times after data acquisition, before the vessel can be demobilized, increasing the cost of survey. The solution tested here consisted on the development of an efficient Real- Time QC by testing Spectral Comparison and Signal to Noise Ratio Attribute (tools developed for the SPW seismic processing software). The detection and identification of bad data by the automatic QC tools was made and the parameters adapted to include at least all manual QC flags. Also, the detection and identification of common problems during acquisition, such strong wave motion and its direction, strong propeller’s wash, trouser’s effect and malfunction in sources or receivers were carried out. The premature detection of these problems will allow to solve them soon enough to not compromise the data acquisition. Several problem reports from beta tests of SPW were transmitted to the Parallel Geoscience team, to be used as a reference to update the software and fulfil Real-Time QC requirements. These updates brought the correct mapping of data headers in files, optimization of data analysis speed along with multi-thread processing debug, to assure it will be running fast enough to avoid delays between acquisition and Real-Time QC, software design to read a variable number of source signatures, optimization of graphic memory limits and debugging of anomalous spectral semblance values. Some updates resulted from a data acquisition simulation that was set up in the office, to make some adjustments to be later tested on an upcoming survey. The parameterization of these tools was finally achieved, assuring the correct detection of all major issues found during the survey, what will eventually lead to the reduction of time needed for QC stage on board, as also to the improvement of its efficiency.
28
Mondière, Aurélien. "Contrôle des propriétés mécaniques de l’acier Ferrium® M54® par la maîtrise de sa microstructure au cours du traitement thermique dans l’optique d’applications aéronautiques." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0006/document.
Full textAbstract:
L’acier Ferrium® M54® présente une composition chimique optimisée, basée sur 40 ans d’évolution et de développement des aciers à durcissement secondaire à précipitation de carbures M2C. Le compromis de propriétés Rm/KIC/KISCC obtenu par la nuance M54® permet d’envisager son utilisation dans les trains d’atterrissage d’avions gros porteurs. Cependant, les premiers essais mécaniques, réalisés par l’utilisateur pour la montée en maturité de la nuance, ont montré une variabilité des propriétés mécaniques suivant le traitement thermique appliqué. Ce travail de thèse s’applique donc à décrire les évolutions microstructurales au cours du traitement thermique de la nuance M54® et les impacts sur les propriétés mécaniques en se concentrant notamment sur le traitement par le froid. Les différentes conditions de mise en solution et de revenu testées ont montré une certaine stabilité de la précipitation au revenu et des propriétés mécaniques qui en découlent. La précipitation a été caractérisée à différentes échelles afin de la comparer avec celle issue des nuances de la même famille. En revanche, selon les conditions de traitement par le froid réalisées, la limite d’élasticité varie de manière significative sans qu’aucun des paramètres liés à la précipitation ne soient modifiés. Le taux d’austénite est en revanche un paramètre déterminant pour la limite d’élasticité et est très sensible aux conditions de traitement par le froid : temps et température entre la trempe à l’huile et le traitement cryogénique et température de traitement cryogénique. Un traitement thermique amélioré a ainsi été proposé pour obtenir un taux d’austénite réduit et constant et limiter ainsi les variations de limite d’élasticitéFerrium® M54® steel presents an optimized composition, based on 40 years of research and development on secondary hardening steels. This alloy exhibits an excellent Rm/KIC/KISCC balance that allows considering its use in landing gears applications of wide-body aircrafts in the future. However, initial mechanical tests performed by the end-user have shown variability in mechanical properties depending on the applied heat treatment. The main goal of this work is to describe the microstructural evolutions of the alloy M54® during heat treatment and their impact on the resulting mechanical properties with a specific focus on the effect of the cryogenic treatment.The different austenitizing and tempering conditions investigated have shown a stability of the tempering precipitation and mechanical properties. This precipitation has been characterized at different scales and compared with other grades of the same family. On the other hand, depending on cryogenic treatment conditions, a significant variation of the mechanical properties and in particular of the yield strength is observed without any modification in the precipitation distribution and volume fraction or size. Austenite content is critical for the yield strength and is very sensitive to the cryogenic treatment conditions: time and temperature before cryogenic treatment and temperature of cryogenic treatment. An improved heat treatment to obtain reduced and constant austenite content is proposed
29
Katata, Enoque Paulo. "Avaliação do impacto das condições de operação na qualidade do sinal : processamento de dados de reflexão sísmica de multicanal." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15655.
Full textAbstract:
Mestrado em Engenharia GeológicaAtravés do processamento de dados sísmicos convertem-se registos de campo em secções sísmicas com significado geológico, que revelam informações e ajudam a delinear as camadas geológicas do subsolo e identificar estruturas soterradas. Portanto, a interpretação dos dados sísmicos só é boa se o processamento também o for. Este trabalho é resultado de um estágio curricular na empresa de prospecção geofísica GeoSurveys, que consistiu principalmente em processar 18 linhas de dados de sísmica de reflexão multicanal de alta resolução adquiridas na ilha de Pulau Tekong em Singapura, que têm como finalidade investigação do solo da baia desta mesma ilha. Estes dados foram cedidos à GeoSurveys para fins académicos, caso em que se inclui esta dissertação. Para atingir os objectivos propostos que consistiam em avaliar o impacto das condições de operação na qualidade do sinal sísmico e interpretação das linhas, fez-se o processamento das linhas utilizando um fluxo processamento padrão utilizado na empresa, com recurso ao software Radex Pro. Este fluxo de processamento tem como mais-valia o método de correcções estáticas, o UHRS trim statics, além das técnicas habituais utilizadas para melhorar a resolução das secções sísmicas como é o caso da desconvolução, a atenuação de ruído através do stacking, correcções de NMO, e migração, entre outras técnicas. A interpretação das linhas sísmicas processadas foi feita no software Kingdom Suite (IHS), através da distinção da configuração interna dos reflectores em cada secção sísmica, estabelecendo deste modo as principais unidades sismo-estratigráficas e identificando as zonas de interface que delimitam os horizontes principais. Foi feito ainda um estudo geológico sumário da área de pesquisa e da evolução geodinâmica da região.
Through seismic data processing, multichannel seismic field records are converted into seismic sections with geological meaning, which help to delineate the subsurface geological layers and identify any buried structures. Therefore, seismic data interpretation is only good as the processing is. This work is the result of a curricular internship in a geophysical prospecting company, GeoSurveys. It consisted mainly of processing 18 high resolution seismic reflection multichannel lines obtained on the Island of Pulau Tekong, in Singapore, which were acquired to investigate the bottom and subsurface sediments of the Island bay. This work was kindly released to GeoSurveys for academic purposes, as it is the case of this dissertation. To achieve the objectives of this thesis, which are to assess the impact of operating conditions and processing on the quality of seismic signal and interpretation of the seismic lines, 18 seismic lines were processed with a standard processing flow used in the company, on the Radex Pro software. This processing flow has as the advantage of using the statics corrections method UHRS trim statics, besides the usual techniques used to improve the seismic resolution sections, such as deconvolution and noise attenuation by stacking, NMO corrections, and migration, among other techniques. The interpretation was made using the Kingdom software, through the analysis of the reflections internal configuration, and the identification of the main stratigraphic units. A summary geological study of the area of research area, together with its geodynamic evolution was also made and is presented in this thesis.
30
Maia, Thais Laudares Soares. "Estratégias de enfrentamento e significados de câncer incurável entre usuários de um serviço ambulatorial de oncologia da Baixada Santista." Universidade Católica de Santos, 2017. http://biblioteca.unisantos.br:8181/handle/tede/3421.
Full textAbstract:
Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2017-03-20T19:58:07Z
No. of bitstreams: 1
Thais Laudares Soares Maia.pdf: 2383778 bytes, checksum: 63872173da6a935884954d9df67bf090 (MD5)Made available in DSpace on 2017-03-20T19:58:07Z (GMT). No. of bitstreams: 1 Thais Laudares Soares Maia.pdf: 2383778 bytes, checksum: 63872173da6a935884954d9df67bf090 (MD5) Previous issue date: 2017-02-21
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Cancer is a serious public health problem. The World Health Organization (WHO) considers in 27 million new cases of cancer by the year 2030 in the whole world. In Brazil, the frequent diagnose of cancer in advanced phase results in a delay of treatment and invalidate possibilities of cure. Nowadays, the Unique Health System (UHS) advocates to the patients with cancer, without possibilities of cure, the approach in palliative cares that is still recent, limited and little consolidated in health services. The study had as objective to analyse the strategies of confrontation and meanings of cancer without possibility of cure in users of outpatient oncology service from UHS. It was done a qualitative study with semi-structured interviews with 11 participants of both sexes, age from 18 years old and diagnosed with cancer without possibilities of cure. The results were analysed in the following reaction categories: 1) sadness and hope; 2) process of sickness; 3) ¿I don¿t want these words¿; 4) non-clinical context; 5) God¿s will; 6) family comfort; 7) sickness and losses; 8) organic and existential pain; 9) psychosocial aspects of sickness; and 10) eminence of death in health services. One identified the need of reflecting about the relational aspects and cares that envolve the patients without possibilities of cure, considering the advance of medicine and of technology and on the other hand, the need to rescue the human relation aspects between health professionals and patients.
O câncer é um grave problema de saúde pública. A Organização Mundial da Saúde (OMS) estima em 27 milhões de novos casos de câncer para o ano de 2030 em todo o mundo. No Brasil, o frequente diagnóstico de câncer em fase avançada resulta no atraso do tratamento e inviabiliza as possibilidades de cura. Atualmente, o Sistema Único de Saúde (SUS) preconiza aos pacientes com câncer, sem possibilidades de cura, a abordagem em cuidados paliativos, que ainda é recente, restrita e pouco consolidada nos serviços de saúde. O estudo teve como objetivo analisar as estratégias de enfrentamento e significados do câncer sem possibilidade de cura em usuários de um serviço ambulatorial de oncologia do SUS. Foi realizado estudo qualitativo com entrevistas semiestruturadas com 11 participantes de ambos os sexos, idade a partir de 18 anos e diagnosticados com câncer sem possibilidades de cura. Os resultados foram analisados nas seguintes categorias empíricas: 1) Tristeza e esperança; 2) processo de adoecimento; 3) ¿eu não quero essas palavras¿; 4) contexto não clínico; 5) vontade divina; 6) o conforto da família; 7) adoecimento e perdas; 8) dor orgânica e existencial; 9) aspectos psicossociais do adoecimento; e 10) a eminência da morte nos serviços de saúde. Identificou-se a necessidade de refletir sobre os aspectos relacionais e de cuidados que envolvem os pacientes sem possibilidades de cura, considerando o avanço da medicina e da tecnologia e, por outro lado, o necessário resgate aos aspectos humanísticos da relação entre profissionais de saúde e os pacientes.
31
Kehler, Beth A. "Modeling and experiments to explain the potential dependency of an UHSS to hydrogen environment assisted cracking /." 2008. http://wwwlib.umi.com/dissertations/fullcit/3302222.
Full text
32
Rosa, André Gonçalo Dias. "Estudo da fratura de aços avançados de alta resistência." Master's thesis, 2020. http://hdl.handle.net/10773/31299.
Full textAbstract:
Nas últimas décadas têm surgido novos aços com características aparentemente incompatíveis como sejam o aumento simultâneo da resistência e da ductilidade. É neste enquadramento que surgem os aços avançados de alta resistência, como os aços CP (complex phase), DP (dual phase), TWIP (twinning induced plasticity) e TRIP (transformation induced plasticity). Neste contexto, foi feita uma análise química, microestrutural e mecânica ao aço de dupla fase DP980. Sobre a análise química descobriu-se a composição elementar do aço DP980. Na análise microestrutural foram obtidas imagens através de um microscópio eletrónico de varrimento, onde se destacou ferrite e martensite. Da análise mecânica obtiveram-se vários dados experimentais, através de ensaios de tração, como a tensão de cedência, a tensão de rutura, a tensão de corte, as deformações principais máxima e mínima, as deformações reais, os ângulos de corte, etc. Os mesmos foram obtidos através de ensaios à tração e de corte de provetes e de onde foram obtidos resultados que foram comparados com os já existentes. Numericamente, foram obtidos através de simulação com software solidworks, o deslocamento, a deformação e a tensão von Mises, distribuídos pelos provetes que foram apresentados sob forma de imagens, com uma escala, fornecendo uma boa interpretação dos resultados obtidos experimentalmente. Estes dados foram comparados com os obtidos por correlação digital de imagem, onde foram verificadas semelhanças entre os dados experimentais e os dados numéricos. Foi feito um diagrama limite de enformabilidade, importante para prever o comportamento à fratura do aço DP980. O mesmo foi obtido com o auxílio de dados retirados dos ensaios experimentais.On the last decades, several new steels with apparently incompatile characteristics such as the simultaneous increase in resistance and ductility have emerged. It is in this framework that arise advanced high strenght steels, such as CP (complex phase), DP (dual phase), TWIP (twinning induced plasticity) or TRIP (transformation induced plasticity). In this context, a chemical, a microstructural and a mechanical analysis were made to double phase DP980 steel. On chemical analysis it was discovered the elementary composition of DP980 steel. In the microstructural analysis there have been obtained images through scanning optical microscope where ferrite and martensite stood out. About mechanical analysis several experimental data were obtained, such as yield stress, breaking stress, shear stress, principal maximum and minimum strains, real strains, shear angles, etc. The same were obtained through tensile and shear tests of specimens and results have been obtained and compared to already existent ones. Numerically, displacement, strain and von Mises stress distribution amongst specimens have been obtained through solidworks software simulation and have been presented in the form of images, with a scale, providing a good interpretation of the experimentally obtained results. This data have been compared with the one obtained through digital image correlation, where similarities have been verified between experimental and numerical data. There has been made a forming limit diagram, important to predict the fracture behavior of DP980 steel. The same was made with the help of data taken from the experimental tests
Mestrado em Engenharia Mecânica
33
Müller, Katrin Margarete [Verfasser]. "Spätergebnisse nach tiefer Beinvenenthrombose : Therapievergleich UHSK mit Heparin / vorgelegt von Katrin Margarete Müller." 2001. http://d-nb.info/971997403/34.
Full text
34
Uhse, Anette [Verfasser]. "Aktivitätsregulierung der humanen DNS-Topoisomerase I durch den RNS-Spleißfaktor PSF-p54nrb / vorgelegt von Anette Uhse." 2003. http://d-nb.info/968450636/34.
Full text
35
Ni, Shun-Hao. "Design Earthquakes Based on Probabilistic Seismic Hazard Analysis." Thesis, 2012. http://hdl.handle.net/10012/6990.
Full textAbstract:
Earthquake is one of the most destructive natural disasters leading to financial, environmental, and even human losses. The most effective approach to prevent losses induced by structural damage is seismic design for structures, in which the determination of design earthquakes, including seismic design spectra and seismic design ground motions, is of great importance.
Probabilistic Seismic Hazard Analysis (PSHA) has been widely used for the determination
and selection of design earthquakes. However, there are a number of issues on the engineering application of PSHA in obtaining the design earthquakes, which need to be
addressed before it can be readily implemented into reliability- and performance-based seismic design. In this research, based on the PSHA, the generation of seismic design spectra and spectrum-compatible earthquake groundmotions is studied.
The PSHA-based seismic design spectra mainly include Uniform Hazard Spectrum (UHS), predicted spectrum based on Ground-Motion Prediction Equations (GMPEs), and Conditional Mean Spectrum considering ε (CMS-ε). These existing design spectra, however, do not or only partially provide probabilistic knowledge about the simultaneous
occurrence of spectral accelerations at multiple vibration periods. The lack of such probabilistic knowledge of the design spectra may prevent them from being incorporated into
reliability- and performance-based seismic design.
The purpose of this study is to bridge the gaps between seismological analyses and
engineering applications, i.e., to find suitable representations of design earthquakes from the PSHA. A generalized approach is developed to generate seismic design spectra using both scalar and vector-valued PSHA,which overcomes the deficiencies and preserves certain advantages of the existing PSHA-based seismic design spectra. An approximate approach is also developed to simplify the approach to the generation of seismic design spectra so that they can be easily incorporated into structural design and further performance-based seismic design.
On the other hand, spectrum-compatible earthquake ground motions, which are generated by manipulating recorded ground motions, have been widely used for seismic design verification and seismic qualification of structures. The existing spectral matching algorithms in frequency-domain, however, may distort the valuable information contained in
recorded earthquake ground motions due to the deficiency of the transformation methodologies on which they are based.
To properly preserve the frequency contents and nonstationary characteristics of recorded
ground motions, a signal processing method called Hilbert-Huang Transform (HHT) is
used to generate spectrum-compatible earthquake ground motions. In the proposed generation procedures, the strategy of the selection of recorded ground motions is based on the PSHA so that the generated ground motions reflect realistic seismic hazard for the site of interest.
36
Metzner, Karim. "Valuation of a healthcare company on the example of universal health services." Master's thesis, 2017. http://hdl.handle.net/10362/28414.
Full textAbstract:
The purpose of this report is to guide the reader’s decision whether to invest or not to invest in
Universal Health Services, Inc. (UHS) stocks. To provide comprehensive insides, we first analysed
the business model, the hospital industry in the USA, macroeconomic trends and the political
environment that could influence the valuation of UHS. Based on the gathered information, we
performed three different types of valuation models. A peer multiple-based valuation, a residual
operating income valuation and a discounted cash flow valuation. All three models lead us to the
belief that the intrinsic value of UHS’ share is essentially higher than the market valuation of 106,81
US$ on the 02.01.2017. For UHS, we set a target price of 123,31US$.
Therefore, we conclude that the share of Universal Health Services, Inc. is undervalued and give
the recommendation: BUY.
37
Francisco, Andrade António. "Quality control of the positioning data in ultra high resolution reflection seismics." Master's thesis, 2020. http://hdl.handle.net/10773/30581.
Full textAbstract:
The quality control is a very important operation in the seismic data acquisition
surveys and its main goals are to assess the quality of the acquired data, to
detect problems during acquisition and finally to guarantee that the data has the
required quality to be accepted for further processing, or if it must be rejected.
The time spent in operations makes its cost to grow up and therefore the QC
must be done efficiently and as early as possible., It is critical that the most
relevant factors that can seriously compromise the data are evaluated onboard.
Navigation quality control is extremely important because the navigation errors
can contribute to the feathering effect that by itself is one of the main rejections
criteria. On the other hand, the quality of the positioning data can have strong
influence on the seismic resolution, as it is used to calculate positioning for every
reflection point. Thus, wrong positioning data affect offsets computing and can
move the reflection midpoints to erroneous position causing a discrepancy
between the actual geology and the seismic section obtained. This causes errors
in the exact location of boulders and the identification of other in-depth hazards
that threat the optimization of wind turbine installations, which is one of
Geosurveys goals in this type of surveys.
The main sources of these problems are related to the bad functioning of GPS
antennas used in the acquisition system and other systematic problems such as
geometry assignment. There are typical errors which affect the geometry such
as distance measurement between lead buoy center and first channel, distance
measurements and assignment between channels in the different streamer
sections. The solution proposed in this work consists on the development of
effective methods to diagnose these types of problems, where through a
graphical scheme it becomes possible to detect different types of positioning
errors and their causes.
The method developed in the scope of this work was based on the quality control
of the offsets calculated with the positioning data and the direct arrivals time.
With this information it was possible to establish a classification criterion for the
positioning data according to its quality, to calculate the errors and obtain
indicators about its source of error, always considering that the various factors
have different influences on the errors and some problems appear more
frequently than others. Based on this, rejection criteria for data with positioning
errors was established and solutions were tested in the software packages
RadExPro and Kingdom Suite, in order to evaluate the effect of these errors on
the seismic volumes.O controle de qualidade é uma operação muito importante durante as campanhas de aquisição de dados sísmicos. Tem como objetivo avaliar a qualidade dos dados adquiridos, detetar problemas ocorridos durante a aquisição, e finalmente assegurar que os dados têm a qualidade necessária para serem aceites ou se devem ser rejeitados. O tempo de operação tem consequências diretas sobre os custos e, por esta razão, esta é uma operação que deve ser feita rapidamente. Assim, devem ser avaliados os fatores mais relevantes que podem comprometer seriamente a qualidade dos dados. O controle de qualidade da navegação é de extrema importância, visto que os erros de navegação contribuem para o feathering, que por sua vez constitui um dos principais critérios de rejeição. Por outro lado, a qualidade da navegação ou dos dados de posicionamento pode afetar fortemente a resolução sísmica pelo facto de serem usados para a determinação das posições das reflexões. Assim, dados de posicionamentos errados afetam os cálculos dos offsets e podem deslocar os pontos médios de reflexões para posições erradas, provocando uma discrepância entre a geologia real e a secção sísmica obtida. Deste modo, fica mais difícil a localização exata de blocos rochosos e a identificação de outros perigos em profundidade que colocam em risco a otimização das instalações das turbinas eólicas, trabalhos que a Geosurveys tem vindo a realizar. As principais causas na origem destes problemas estão relacionadas com o mau funcionamento das antenas GPS usadas no sistema de aquisição, e outros problemas sistemáticos, como a atribuição de geometria. Existem erros típicos que afetam a geometria, tais como o erro na medição da distância entre o centro da antena da lead buoy e o primeiro canal, e erros na medição e atribuição das distâncias entre canais para as diferentes secções dos streamers. A solução proposta neste trabalho passou pelo desenvolvimento de métodos eficientes para diagnóstico destes tipos de problemas, onde através de padrões gráficos se torna possível detetar diferentes tipos de erros de posicionamentos e as respetivas causas. O método desenvolvido baseou-se no controle de qualidade dos offsets calculados com os dados de posicionamento e no tempo de chegada das ondas diretas. Com essas duas informações foi possível estabelecer um critério de classificação dos dados de posicionamento quanto à sua qualidade, calcular os erros e obter indícios sobre a sua origem, levando sempre em consideração que os vários fatores têm diferentes influências sobre os erros e que alguns problemas são mais frequentes que outros. Com base neste procedimento, foram estabelecidos critérios de rejeição de dados com erros de posicionamento. As soluções obtidas foram testadas no software RadExPro e Kingdom Suite de modo a avaliar o efeito que esses erros têm sobre a sísmica.
Mestrado em Engenharia Geológica
38
Vigan, Medji Doreen Peggy Rose. "Analyse de l’implantation du régime d’assurance maladie universelle (RAMU) au Bénin : obstacles et facteurs facilitants." Thèse, 2017. http://hdl.handle.net/1866/20566.
Full text
39
Fredriksson, Mikael, Elin Åkerlund, Jakob Åberg, Patrik Österberg, and Rebecka Havo. "High Performance Steel for Percussive Drilling." Thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-323789.
Full textAbstract:
Atlas Copco Secoroc AB are searching after new bulk materials for drill heads that are used in percussive drilling in order to improve their strength and durability. The aim of this project is to assist Atlas Copco in this search and provide them with further information regarding material properties, alloying elements, suppliers, etc. A literary study was carried out in order to identify materials that had UTS and KIC more than or equal to 1700 MPa and 70 MPa*m^1/2, respectively. Materials that fulfilled these criteria were T250 grade maraging steel, Cobalt free maraging steel, High cobalt maraging steel, 300 grade maraging steel, AerMet 100, AF1410, S53, M54, 300M, 4340M and PremoMet. These were categorized into maraging steels, high alloy secondary hardened steels, and low alloy steels, and were then further researched. The material with the highest combination of UTS and KIC was M54 followed by AerMet 100; while AF1410 had the highest KIC but a low UTS, and PremoMet had the highest UTS but a low KIC. Maraging steels and HASH steels have a similar price range, while low alloy steels are much cheaper.