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Dissertations / Theses on the topic 'R-curve'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Dourado, Nuno Miguel. "R-Curve behaviour and size effect of a quasibrittle material : wood." Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13734/document.

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Ce travail concerne des expériences mécaniques, des analyses numériques et des modélisations analytiques de la rupture cohésives (Mode I), vis-à-vis de l’étude du comportement mis en évidence par la courbe de Résistance (Courbe-R) et l’effet d’échelle de structures entaillées en bois massif. Des expériences de fissuration sont combinées à des analyses numériques pour déterminer les propriétés de rupture au moyen d’une procédure appelée Théorie de la Mécanique de la Rupture Linéaire Élastique équivalente (TMRLE), basée sur la complaisance de la structure. La courbe-R, obtenue à partir des expér

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Dourado, Nuno Miguel Moura Marcelo de Valentin Gérard. "R-Curve behaviour and size effect of a quasibrittle material wood /." S. l. : S. l. : Bordeaux 1 ; Universidade do Porto (Portugal), 2008. http://ori-oai.u-bordeaux1.fr/pdf/2008/DOURADO_NUNO_2008.pdf.

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Thèse de doctorat : Sciences physiques et de l'ingénieur. Mécanique : Bordeaux 1 : 2008. Thèse de doctorat : Sciences physiques et de l'ingénieur. Mécanique : Universidade do Porto (Portugal) : 2008.<br>Titre provenant de l'écran-titre.

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3

Bernardini, Chiara. "Un risultato di h-principle per curve a curvatura costante in R^n." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21250/.

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Oggetto di questa tesi è mostrare che ogni curva liscia immersa nello spazio euclideo n-dimensionale, può essere deformata in una curva con curvatura costante, mediante una perturbazione arbitrariamente piccola della curva iniziale e delle sue rette tangenti. Tale valore costante della curvatura deve essere maggiore o uguale del massimo della curvatura della curva iniziale, e si dimostra che tale limite inferiore è ottimale. Questo significa che le curve lisce di curvatura costante, soddisfano, secondo la terminologia di Gromov, il `relative C^1-dense h-principle' nello spazio delle curve imme

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Cheung, C. M. S. "The R-curve approach for the fracture assessment of an aluminium alloy bridge." Thesis, Swansea University, 2001. https://cronfa.swan.ac.uk/Record/cronfa42424.

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A result of fatigue testing on a full scale aluminium alloy bridge, which is used by the military for temporary crossings, showed an unexpected increase in fracture resistance, compared with its plane strain K[IC]. This increase was due to a combination of low constraint and large stable crack extension in the bridge components. Previous work had attributed the increase to the loss of constraint alone, but the present work shows stable cracking is equally important. The effect of stable cracking in the bridge alloy was first examined experimentally in large 25mm thick 3PB specimens which were

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5

Heinrich, Benedikt [Verfasser], and Heinrich von [Akademischer Betreuer] Weizsäcker. "Curve interactions in R^2: An analytical and stochastical approach / Benedikt Heinrich. Betreuer: Heinrich von Weizsäcker." Kaiserslautern : Technische Universität Kaiserslautern, 2013. http://d-nb.info/1044294183/34.

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6

Colafemea, Angelo Antonio. "Modelamento numérico da técnica de normalização linear para determinação de curvas J-R." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-20092016-115454/.

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Neste trabalho os resultados da metodologia de normalização de E. D. Reese e K. H. Schwalbe para a obtenção de curvas J-R, são comparadas com aquelas obtidas pela tradicional Técnica de Variação de Flexibilidade Elástica. Ambos os métodos foram aplicados à um aço de grau nuclear A508-CL3A, quando vários corpos-de-prova miniaturizados 0.394TC[S], foram testados em temperaturas típicas de operação de vasos de pressão nuclear. Corpos-de-prova miniaturizados formam tratados termicamente tentando simular o comportamento exibido pelos aços estruturais quando submetidos à diferentes níveis de exposiç

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7

Zúñiga, Munizaga Andrés Jahir. "Entire solutions to the inhomogeneous allen-cahn equation in R^2, with a transition on a noncompact curve." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/111186.

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Ingeniero Civil Matemático<br>Este trabajo de memoria de título presenta un estudio de la ecuación de perturbación singular de Allen-Cahn con inhomogeneidad: \begin{equation}\ep^2\div\left(a(x)\cdot\nabla_{x}u(x)\right)+a(x)f(u(x))=0,\quad\text{ en }\quad\R^2 \label{AllenCahnEq}\end{equation} donde $\varepsilon>0$ es un parámetro pequeño, $a(x)$ es un potencial uniformemente positivo y suave, que induce una forma de medir distancias para puntos en $\R^2$, y $f$ es la nolinealidad dada por $f(u)=u-u^3$. El estudio aborda la construcción de soluciones enteras de~\eqref{AllenCahnEq}, bajo la co

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8

Pásztor, Bálint. "Analýza přežití v R." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-202126.

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Survival analysis is a statistical discipline that analyzes the time to occurrence of certain events. The aim of this thesis is to describe the possibilities of survival analysis in the environment of statistical software R. Theoretical knowledge is applied to real data, parametric and nonparametric estimates of survival functions are evaluated by different methods and compared with each other. In the section focusing on nonparametric models Kaplan-Meier and Nelson-Aalen functions are described. Among the parametric estimates there were included well-known probability distributions, survival f

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9

Dzugan, Jan. "Crack lengths calculation by unloading compliance technique for Charpy size specimens." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-29077.

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The problems with the crack length determination by the unloading compliance method are well known for Charpy size specimens. The final crack lengths calculated for bent specimens do not fulfil ASTM 1820 accuracy requirements. Therefore some investigations have been performed to resolve this problem. In those studies it was considered that measured compliance should be corrected for various factors, but satisfying results were not attained. In the presented work the problem was attacked from the other side, the measured specimen compliance was taken as a correct value and what had to be adjust

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10

Tilbrook, Matthew Thomas Materials Science &amp Engineering Faculty of Science UNSW. "Fatigue crack propagation in functionally graded materials." Awarded by:University of New South Wales. Materials Science & Engineering, 2005. http://handle.unsw.edu.au/1959.4/21885.

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Propagation of cracks in functionally graded materials (FGMs) under cyclic loading was investigated via experiments and finite element (FE) analysis. Alumina-epoxy composites with an interpenetrating-network structure and tailored spatial variation in composition were produced via a multi-step infiltration technique. Compressed polyurethane foam was infiltrated with alumina slip. After foam burn-out and sintering, epoxy was infiltrated into the porous alumina body. Non-graded specimens with a range of compositions were produced, and elastic properties and fatigue behaviour were characterised.

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Dzugan, Jan. "Crack lengths calculation by unloading compliance technique for Charpy size specimens." Forschungszentrum Rossendorf, 2003. https://hzdr.qucosa.de/id/qucosa%3A21733.

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The problems with the crack length determination by the unloading compliance method are well known for Charpy size specimens. The final crack lengths calculated for bent specimens do not fulfil ASTM 1820 accuracy requirements. Therefore some investigations have been performed to resolve this problem. In those studies it was considered that measured compliance should be corrected for various factors, but satisfying results were not attained. In the presented work the problem was attacked from the other side, the measured specimen compliance was taken as a correct value and what had to be adjust

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12

Sorin, Edouard. "Fissuration en modes mixtes dans le bois : diagnostic et évaluation des méthodes de renforcement local." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0264/document.

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Cette thèse s’effectue au sein de l’université de Bordeaux. Ce projet concerne la construction en bois et en particulier la compréhension des phénomènes à l’origine des fissures dans les structures bois. L’un des objectifs étant de concevoir des méthodes efficaces de renforcement local pour les éléments de structure. Pour cela, l’étude se décompose en plusieurs étapes, la compréhension des phénomènes mis en jeu dans la création des fissures sur des bois de construction. Ce travail s’orientera sur la modélisation de fissure en mode mixte, la recherche de solution de renforcement avec compréhens

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13

Stratil, Luděk. "Určování lomově-mechanických charakteristik z podrozměrných zkušebních těles." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-234223.

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The standards of fracture toughness determination prescribe size requirements for size of test specimens. In cases of limited amount of test material miniature test specimens offer one from the possibilities of fracture toughness evaluation. Because of small loaded volumes in these specimens at the crack tip the loss of constraint occur affecting measured values of fracture toughness. In such cases the size requirements for valid fracture toughness characteristics determination are not fulfilled. These specimens can be even on limits of load range of test devices and handle manipulation by the

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14

Adamiec, Grzegorz. "Aspects of pre-dose and other luminescence phenomena in quartz absorbed dose estimation." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325679.

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15

Holas, Jiří. "Testování lomové houževnatosti za vysokých teplot s využitím miniaturních CT těles." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231783.

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This master´s thesis deals with the evaluation of fracture behavior of ODS steel MA956 at high temperature range. This behavior was tested by using miniaturized CT specimens, on which were performed experiments to measure of ductile crack growth resistance curves (J-R curves). The value of the fracture toughness was determined from these J-R curves. Fracture properties were consequently evaluated by using fractographic analysis of the fracture surfaces. Structural properties of material was identified by hardness measurement and analyzed by metallographic methods. Results of the measurements s

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16

Mrňa, Tomáš. "Vliv velikosti tělesa na R-křivku a na otupení čela trhliny." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-242858.

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The thesis deals with the determination of fracture toughness using compact tension (CT) test specimens at elevated and high temperatures. The experimental material steel P91 designated for application at temperatures 550650°C was used. The fracture toughness in the ductile fracture region of the steel was characterized by the R curve, which characterises the resistance against crack propagation depending on the crack length. The effect of temperature on the R curve at range 23600°C was evaluated. Next the specimen size effect using three sizes of CT specimens at 23°C and the effect of loading

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17

Lokvenc, Martin. "Testování lomové houževnatosti za vysokých teplot s využitím miniaturních CT těles." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231784.

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This thesis deals with a high temperature testing of fracture toughness and studies the size effect on measured values using miniature size CT specimen. Two types of specimen geometry were manufactured from P91 steel, the standard size and the quarter size specimen. J-R curves were obtained in the temperature range from 23°C to 600°C. No specimen size effect was observed at room temperature tests. The realized experiments together with fractography analysis demonstrated the drop of toughness at 400°C caused by the effect of dynamic strain aging.

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18

坂井田, 喜久, Yoshihisa SAKAIDA, 啓介田中 та Keisuke TANAKA. "多孔質セラミックスの破壊靭性評価". 日本機械学会, 2001. http://hdl.handle.net/2237/9161.

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19

SAKAIDA, Yoshihisa, and Keisuke TANAKA. "Evaluation of Fracture Toughness of Porous Ceramics." The Japan Society of Mechanical Engineers, 2003. http://hdl.handle.net/2237/9181.

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20

Eu, David. "Polygonal curve approximation." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56992.

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Given a polygonal curve $P = lbrack p sb1,p sb2 ... p sb{n} rbrack$, the polygonal approximation problem considered in this thesis calls for determining a new curve $P sp prime = lbrack p sbsp{1}{ prime}, p sbsp{2}{ prime}, ..., p sbsp{m}{ prime} rbrack$ such that (i) m is significantly smaller than n, (ii) the vertices of $P sp prime$ are a subset of the vertices of P and (iii) any line segment $ lbrack p sbsp{A}{ prime}, p sbsp{A+1}{ prime} rbrack$ of $P sp prime$ that substitutes a chain $ lbrack p sb B, ...,p sb C rbrack$ in P is such that for all i where $B le i le C$, the approximation e

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21

Kramoliš, Ondřej. "Extrakce a modifikace vlastností číslicových zvukových signálů v dynamické rovině." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218782.

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This thesis deals with basic methods of root mean square and peak value measurement of a digital acoustic signal, algotithms to measure audio programme loudness and true-peak audio level according to recommendation ITU-R BS.1770-1 and digital systems for control of signal dynamic range. It shows achieved results of root mean square and peak value measurement and results of implementation of dynamic processor with general piecewise linear non-decreasing static curve and algorithms according to recommendation ITU-R BS.1770-1.

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Hemzalová, Zuzana. "Evoluční algoritmy pro ultrazvukovou perfúzní analýzu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442504.

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This thesis deals with the principles of ultrasonic perfusion analysis and methods for determining perfusion parameters. It examines Evolutionary algorithms and their ability to optimize the approximation of dilution curves from ultrasond tissue scannig. It compares the optimization performance of three evolutionary algorithms. Continuous genetic algorithm GA, algorithm SOMA and PSO. Methods are evaluated on simulated and clinical data.

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23

Nkgau, Tallman Zacharia. "Elliptic curve cryptosystems : a survey." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21614.

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Elliptic curves have been a subject of much mathematical study since early in the past century. Recently, through the work of Koblitz and Miller, they have found application in the area of publickey cryptography. The basic reason is that, elliptic curves over finite fields provide an abundance of finite abelian groups which could be used as a basis for public-key cryptosystems. The objective of this thesis is to survey the field of elliptic curve public-key cryptography as it exists now, with an attempt to identify key ideas and contributions. We are particularly interested in elliptic curve c

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Rempel, William. "Curve evolution and integrable systems." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95240.

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In this thesis, we explain the connection between completely integrable systems of evolution equations and the evolution of the differential invariants of group actions in the particular case of a curve in Rⁿ acted on by an affine group defined as the semidirect product of G and Rⁿ, where G is semisimple, as it is presented in the work of Marì-Beffa. This connection involves Fels and Olver's work on the theory of moving frames, infinite-dimensional Hamiltonian systems and Poisson brackets, and centrally extended loop groups and algebras. We also summarize the relevant theory both of Lie

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Parent, Pierre 1953. "Trace inference, curvature consistency, and curve detection." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66100.

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26

Tarragó, Cifre Jose María. "Damage tolerance of cemented carbides under service-like conditions." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/403888.

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Hardmetal industry is continuously seeking for high-performance products at reduced costs. In addition, it is strongly struggled by the high and volatile prices of raw materials. At this juncture, producers and end-users are deeply concerned in increasing the performance and enhancing service-life and reliability of engineering products, and replacing current constituents by alternative and less critical materials. Premature and unexpected fracture, together with wear, is the main damage phenomenon limiting the life in most cemented carbide applications. In the vast majority of cases such rupt

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27

Torchiani, Carolin [Verfasser]. "Enumerative geometry of rational and elliptic tropical curves in R m / Carolin Torchiani." München : Verlag Dr. Hut, 2014. http://d-nb.info/1055863834/34.

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28

Karastamatis, Thomas. "Measuring the R-curves of lead zirconate titanate (PZT) from a surface crack in flexure (SCF)." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/16713.

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29

Matoušek, Petr. "Vyhodnocení účinnosti komplexních ochranných opatření k.ú. Jerlochovice v povodí Husího potoka." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227551.

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A subject of this Thesis is the design of the complex system of measures of soil conservation in given catchment area, which will serve as a concept of complex land consolidation in cadaster Jerlochovice. Based on the analysis and the land survey, a feasible solution was designed using the hydrological and erosive tools of ArcGIS. For the identification of areas endangered by erosion and for the identification of runoff conditions, the Universal Soil Loss Equation of Wischmeier-Smith was used (in grid modification). Based on the calculated values, the suitable technical and agrotechnical measu

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Li, Zhe 1974. "The environmental Kuznets curve reexamined for CO₂ emissions in Canadian manufacturing industries /." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80319.

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Recent studies of the environmental Kuznets curve raise questions regarding the relationship between environmental indicators and GDP and the fundamental reasons that explain this relationship. In response, this thesis presents one-sector and two-sector models to analyze the alternative causal relationships between an environmental indicator and GDP at different stages of economic development. These models analyze how economic scale, technology, preferences, and economic structure influence the causality and shape of the relationship. These theoretical studies are followed by two empiri

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田中, 啓介, Keisuke TANAKA, 義明秋庭 та ін. "多孔質セラミックスの切欠き破壊強度のR曲線法による評価". 日本機械学会, 2003. http://hdl.handle.net/2237/9143.

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Ramsay, Craig R. "Assessing the learning curves of health technologies." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602014.

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Many health technologies exhibit some form of learning effect, and this represents a barrier to rigorous assessment by randomised controlled trials. There is reluctance to evaluate while the technique is being learnt, yet unwillingness to admit uncertainty once it has been learnt. In principle, statistical description of a learning curve and subsequent adjustment of an evaluation to take account of learning effects should solve this problem. Exactly how the analyses should be performed has been unclear. This thesis has three components: Systematic review of health technology assessment literat

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SOARES, P. A. "Determinação da Tenacidade à Fratura do Aço API-X65 Utilizado em Tubos na Indústria de Petróleo e Gás." Universidade Federal do Espírito Santo, 2011. http://repositorio.ufes.br/handle/10/4160.

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Made available in DSpace on 2016-08-29T15:32:55Z (GMT). No. of bitstreams: 1 tese_5382_Dissertação de Mestrado (Polliana Alexandre Soares).pdf: 5558925 bytes, checksum: f527e57bc2fba9b5e555b52004855328 (MD5) Previous issue date: 2011-12-27<br>Este trabalho foi desenvolvido com o intuito de determinar a tenacidade à fratura em estruturas contendo trincas em suas juntas soldadas. O material ensaiado foi o aço API X65 que é usado em tubos na indústria de produção de petróleo e gás, por exemplo. O tubo tem diâmetro de 20 polegadas com espessura de 6,8 mm. Foram estudadas duas condições diferente

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Lexen, Ernst R. [Verfasser], and Peter H. [Akademischer Betreuer] Hauschildt. "Parameter sensitivity of synthetic spectra and light curves of Type Ia supernovae / Ernst R. Lexen. Betreuer: Peter H. Hauschildt." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2014. http://d-nb.info/1048626199/34.

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Botros, Lucy L. "Windowed direct exponential curve resolution quantification of nuclear magnetic resonance spectroscopy with applications to amniotic fluid metabonomics." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100769.

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This thesis presents a quantitative protocol of proton nuclear magnetic resonance (1H NMR) that allows the determination of human amniotic fluid metabolite concentrations, which are then used in a metabonomic study to establish patient health during gestation. 1H NMR free inductive decays (FIDs) of 258 human amniotic fluid samples from a 500MHz spectrometer are acquired. Quantitative analyses methods in both the frequency- and time-domain are carried out and compared. Frequency-domain analysis is accomplished by integration of the metabolite peaks before and after the inclusion of a known stan

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Khor, WeeLiam. "Crack tip opening displacement (CTOD) in single edge notched bend (SEN(B))." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16198.

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This thesis investigates the quantity Crack Tip Opening Displacement (CTOD) as a means to assess fracture toughness when measured in the Single Edge Notched Bend (SENB) specimen setup. A particular objective is to assess the effectiveness of the test when used for high strain-hardening materials (e.g. stainless steels). This has been an increasing concern as the current available methods were generally designed for lower strain hardening structural steel. Experimental work on CTOD tests included silicone casting of the crack, and constant displacement tests were also performed. The silicone ca

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Rosa, Vinicius. "Efeito da troca iônica nos parâmetros de Weibull, de crescimento subcrítico de trincas e no comportamento de curva R de uma porcelana odontológica." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/23/23140/tde-03012008-102313/.

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O objetivo deste estudo foi avaliar o efeito da temperatura de troca iônica (TI) nas propriedades mecânicas da porcelana Ultrapaline ST e o efeito da TI nos parâmetros de crescimento subcrítico de trincas (SCG) (coeficiente de SCG - n, parâmetro escalar - ?f0), de Weibull (resistência característica - ?0, módulo de Weibull - m) e no comportamento de curva R desta porcelana. 250 discos (12 mm diâmetro x 1 mm espessura) foram fabricados de acordo com as instruções do fabricante, usinados em retificadora plana e polidos até 1 ?m. Para determinar o efeito da temperatura de TI na resistência à flex

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Varadarajan, Ravikumar. "On the Nature of Static and Cyclic Fracture Resistance of Ultra High Molecular Weight Polyethylenes Used in Total Joint Replacements." Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1164903681.

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Dotta, Fernando. "Previsão da pressão de colapso em dutos para transporte de gás e petróleo contendo defeitos planares incorporando curvas de resistência J-R: uma abordagem micromecânica utilizando critérios locais." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-27112006-172735/.

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Este estudo estende a abordagem micromecânica baseada em células computacionais e a abordagem baseada em deformação utilizando o critério de CTOA para descrever extensão dúctil de trincas longitudinais em dutos de aços de elevada tenacidade sob alta pressão. Ensaios laboratoriais realizados em aços API 5L X60 e X70 utilizando corpos-de-prova padronizados de fratura com trinca profunda, produzem os resultados necessários para medir as curvas de resistência à propagação de trincas e calibrar os parâmetros dos modelos de Gurson e CTOA para estes materiais. O foco central deste trabalho é a aplica

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Bonazzi, Luís Henrique Camargo. "Comportamento em fadiga da liga Al-Li AA 2050." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-17112017-172453/.

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As novas ligas de alumínio que contém lítio são atraentes devido à sua baixa densidade, alto módulo elástico, elevada resistência mecânica e por terem boa resistência à corrosão em comparação com ligas similares que não contém lítio. A degradação do material devido à fadiga e corrosão são os dois principais fatores que contribuem para o envelhecimento de uma aeronave. O objetivo deste trabalho é estudar a resistência à fadiga de uma nova liga de Al-Li, denominada de AA 2050-T84, considerando os estágios de nucleação e de propagação. No primeiro caso são avaliados o efeito da variação do concen

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Costa, Aratã Oliveira Cortez. "Estudo in vitro e in silico da atividade antifúngica dos isômeros r-(+) e s-(-)citronelal sobre fungos do gênero cryptococcus." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9471.

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Submitted by Maike Costa (maiksebas@gmail.com) on 2017-09-08T14:24:47Z No. of bitstreams: 1 arquivototal.pdf: 1265949 bytes, checksum: de2c53fd1f3937b88fb24a29f756845d (MD5)<br>Made available in DSpace on 2017-09-08T14:24:47Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1265949 bytes, checksum: de2c53fd1f3937b88fb24a29f756845d (MD5) Previous issue date: 2017-02-10<br>COSTA, A.O.C. In vitro and in silico evaluation of the antifungal activity of the R- (+) and S-(-) citronelal isomers, aginst fungi of the genus Cryptococcus. 2017. 52f. Dissertação (Pós-graduação em Produtos Naturais e Sintéti

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Rádsetoulal, Milan. "Hodnocení lomového chování svarových spojů používaných v energetickém průmyslu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-442748.

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This thesis is focused on assessment of fracture behaviour of heterogeneous welded joint. The goal is to determine fracture behaviour at the interface of ferritic base metal and austenitic weld metal at temperature of 255°C. This kind of weld is widely used at energy industry. Fracture toughness was evaluated using CT specimens with size 0,5T in order to determine the initiation values of stable crack propagation. Fracture behaviour of the weld is correlated with results of metallography and fractography analysis. Both light and scanning electron microscopy is used for fractography analysis. A

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Francisco, Julio Cesar de Souza. "Resistência à propagação dúctil de trincas em aço API 5L X70 com teor de nióbio modificado." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18150/tde-30032016-110448/.

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Aplicações de alto desempenho, como as de dutos utilizados no transporte de derivados de petróleo, exigem materiais com uma combinação excepcional de propriedades mecânicas, dentre as quais, elevada resistência mecânica, tenacidade e resistência à fadiga. O aço API 5L X70 com adição de nióbio apresenta-se, quando comparado com o API 5L X70 padrão, como sendo uma opção para a melhora em seu processo de fabricação, sendo sua composição química diferenciada, devido a um maior teor de nióbio. A Arcelor Mittal Tubarão tem mostrado interesse em fabricar aços API X70/X80, sem a adição de V e com adiç

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Francisco, Julio Cesar de Souza. "Avaliação da tenacidade à fratura de aço API 5L X70 utilizado na fabricação de dutos transportadores de gás e petróleo." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18150/tde-19012011-111506/.

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A avaliação da integridade estrutural de dutos pelo uso de corpos-de-prova laboratoriais depende da escolha de corpos-de-prova de geometrias que representem condições de restrições plásticas na frente da trinca, similares às encontradas nas condições operacionais dos dutos. O Núcleo de Ensaios de Materiais e Análise de Falhas, NEMAF do SMM, EESC-USP vem realizando pesquisas para o desenvolvimento de corpos-de-prova e metodologias experimentais que melhor represente esta situação. Entretanto, no caso de dutos existem situações onde a geometria e o tamanho do corpo-de-prova são limitados pelas d

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Lima, Toni Roger Schifelbain de. "Desenvolvimento de metodologia para determinação de curvas de resistência à fratura de materiais elasto-plásticos pela análise do campo deformacional à frente da ponta da trinca." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/36011.

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Os conceitos de mecânica da fratura têm sido cada vez mais utilizados em projetos de engenharia, permitindo a determinação de tamanhos críticos de defeito ou limites de solicitação em função da presença de trincas. No entanto, para aplicar com sucesso esses conceitos em uma avaliação de integridade estrutural é de suma importância a determinação exata do comportamento a fratura do material. Materiais com comportamento elasto-plástico têm ocupado cada vez mais lugar de destaque em estruturas e componentes críticos de engenharia e a maneira mais utilizada para caracterização da tenacidade à frat

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Pauletti, Ederson. "ESTUDO DA INFLUÊNCIA DO FENÔMENO DA DELAMINAÇÃO NA TENACIDADE À FRATURA DE AÇOS API 5L X60 E X70 EM ESPÉCIMES SE(T)." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2013. http://tede2.uepg.br/jspui/handle/prefix/1424.

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Made available in DSpace on 2017-07-21T20:42:39Z (GMT). No. of bitstreams: 1 Ederson Pauletti.pdf: 5739200 bytes, checksum: 362611be295a3342251b72d168512c61 (MD5) Previous issue date: 2013-03-22<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>In this work the ductile crack growth resistance curves (J-R curves) was evaluated for the steels used in the oil and gas pipelines from the X60 and X70 API 5L grades using the unloading compliance technique. The non standardized SE (T) specimens were used due to the same has low constraint, it is feature of pipelines. The plastic area

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Silva, Maurício de Carvalho. "Caracterização das propriedades mecânicas e metalúrgicas do aço API 5L X 80 e determinação experimental de curvas J-R para avaliação da tenacidade a fratura." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-11022005-162828/.

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Caracterizar propriedades de resistência à propagação de trinca em materiais dúcteis é um elemento central em métodos de avaliação de integridade estrutural de dutos destinados ao transporte de gás, petróleo e seus derivados que utilizam os aços ARBL. Sendo assim, o objetivo deste trabalho foi estudar as propriedades de fratura dúctil do aço API 5L X80, através da obtenção da curva de resistência à propagação estável de defeitos (curvas J-R) do material. O ensaio de tenacidade à fratura para obtenção da curva J-R foi conduzido utilizando a técnica do corpo-de-prova único (single specimen) empr

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Canterle, Joseane Ortiz Breitenbach. "Avaliação da tenacidade à fratura do aço API 5L X70 em diferentes meios de etanol." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/114982.

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Com a implementação do Programa Nacional do Álcool (Proálcool), Protocolo de Quioto e substituição do MBTE (metil-terci-butil eter) em alguns países nos últimos anos, houve um aumento significativo da produção de etanol. Os dois maiores produtores mundiais de etanol são os Estados Unidos e o Brasil, sendo o etanol oriundo do Milho e da Cana-de-açucar, respectivamente. Transporte por dutos é a forma mais econômica para grandes quantidades, porém, há evidências de que esses dutos de transporte, e também fundo de tanques de armazenamento, possam ser susceptíveis ao fenômeno de corrosão sob tensão

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"Lagrangian angles of foliation in R² under curve shortening flow." 2011. http://library.cuhk.edu.hk/record=b5894787.

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Ma, Man Shun.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.<br>Includes bibliographical references (leaves 75-76).<br>Abstracts in English and Chinese.<br>Chapter 1 --- Introduction --- p.6<br>Chapter 2 --- Basic notions in Riemannian geometry --- p.10<br>Chapter 2.1 --- Basic manifold theory --- p.11<br>Chapter 2.2 --- "Connection, curvature" --- p.19<br>Chapter 2.3 --- Submanifold theory --- p.29<br>Chapter 3 --- Basic facts in symplectic and complex geometry --- p.33<br>Chapter 3.1 --- "Symplectic manifolds, Lagrangian submanifolds" --- p.34<br>Chapter 3.2 --- Kahler an

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Webb, James Ernest. "Elevated temperature effects on R-curve behavior in alumina ceramics." 1995. https://scholarworks.umass.edu/dissertations/AAI9541165.

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I. Crack wake bridges were studied in glassy alumina s-DCB specimens at elevated temperatures. Direct observation of fracture surfaces in unmodified s-DCB specimens revealed the sizes and shapes of the high temperature bridges in the crack wake relative to the position of the crack front. Similar fracture surface observations made on s-DCB specimens modified to include a rear notch wedge, allowing the measurement of the high temperature bridging forces, were used to analyze bridge behavior in terms of viscous and power law creep models. The sizes and positions of the bridges were found to be h

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