21 |
Investigation of high strain rate behavior of metallic specimens using electromagnetic inductive loadingMorales, Santiago Adolfo 20 September 2011 (has links)
Aerospace Engineering / The aim of this thesis is to explore the high strain rate behavior of metallic specimens using electromagnetic inductive loading as the means to inflict the required high strain rate deformation on laboratory scale specimens, allowing for controlled, repeatable experiments to be performed. Three separate experiments were designed and performed, using helical and spiral coils as the sources of radial and unidirectional loading.
The first experiment evaluated the effect of applying a polymer coating on 30.5 mm diameter, Al 6061- O tube samples, in two lengths, 18 and 36 mm. The expanding tube experiment was used to apply a radial loading on the specimens and record the event. Several optical techniques were then used to evaluate the behavior of the samples. Coatings of polyurea and polycarbonate were used. It was observed that the polycarbonate coating seemed to have a more profound effect on the behavior of the metal, by applying a larger restraining pressure on the tube surface during the expansion process, and thereby modifying the stress state of the specimen.
The second experiment looked to design an experimental arrangement to test the plane strain, high strain rate behavior of Al 6061-O tubes of different lengths. A 112 mm long solenoid was designed and manufactured, and testing was performed on 30.5 mm diameter Al 6061-O tubes in lengths of 50, 70 and 90 mm. It was observed that the coil behaved similar to shorter ones at low voltages and that the longer the specimen used, the more its deformation path approached a plane strain condition.
Finally, a third experiment was performed to develop an experiment to accelerate a plate to high linear velocities, as a means to evaluate the use of a flat spiral coil as the driver for future experiments based upon electromagnetic inductive loading. A prototype coil was manufactured and installed into a converted expanding tube experimental setup. Three samples were tested in several sizes, and materials: aluminum and steel. Speeds in the range of 45 to 251 m/s were obtained, validating the apparatus as a viable method to provide a unidirectional loading. / text
|
22 |
‘Neutral, native-like or authentic’ : Investigating attitudes and beliefs of expanding circle speakers of EnglishMelchien, Bianca January 2016 (has links)
The status of English as the language of international communication is by now well-established. However, in the past 16 years, research has tried to emphasize the fact that the English spoken in international contact situations and between people with other first languages than English has different needs than the English spoken locally amongst native speakers, resulting in the emergence of English as a lingua franca (ELF) as a scholarly field. However, the impact of findings in ELF has so far only led to a moderate shift in English language teaching. Especially in expanding circle countries, where ELF should have the biggest impact, change is only gradually becoming palpable. Accent and pronunciation, as one of the biggest factors on both identity and mutual intelligibility (Jenkins 2000; 2007) are at the root of discussion. The scope of this study is therefore to examine accent choices and the extent to which native speaker ideology informs the preferences of ten speakers of ELF and 27 German natives with experience in international communication. Both ethnographical and sociolinguistic methods, as well as auditory analysis have been applied and conducted. The auditory analysis of six variables in the recorded speech production of the ten speakers suggests that there is no significant preference of one norm-giving variety over the other. Rather, speakers tend to mix-and-match General American- and Standard Southern British English-like features in their pronunciation. When reporting their accent ideals, the idea of a ‘neutral’ English accent is mentioned by four participants. Neutral accents seem to have been understood as ‘unmarked accents’. Expressed beliefs on their own English pronunciation show a comparatively high level of reflection on and confidence in their own production. Results from a rating task and a survey given to 27 German participants reveal attitudes that are more negatively stacked. While Germans reported openness towards NNS (non-native speaker) accents and showed awareness of the priority of intelligibility over accent choice in both their own and others’ pronunciation, they still largely reported NS accent preference. The ratings of the production from ten ELF speakers confirmed this and showed that ‘neutral’ is equated with native-like. In the light of these findings, issues are discussed that ultimately relate to the influence of NS Englishes, identity and the development of English as an international language.
|
23 |
Relationship Based Care: Exploring the Manifestations of Health as Expanding Consciousness within a Patient and Family Centered Medical Intensive Care UnitAnanian, Lillian Virginia January 2014 (has links)
Thesis advisor: Dorothy Jones / A family's unique way of being, formulated through social, economic, environmental and political factors, becomes fractured during a loved one's critical illness. Family members experience burdensome physical and emotional symptoms as they transition through the marked uncertainty endemic to high acuity illness. For some, this burden results in long term psychiatric disturbances. Assessment tools and interventions have been proposed for family members experiencing a loved one's critical illness. However, ongoing suffering suggests inherent limitations within these reductionist approaches. The need for a more encompassing disciplinary perspective is suggested. Margaret Newman's (1986, 1994, 2008) theory of Health as Expanding Consciousness (HEC) and its praxis research method was employed to explore relationship based care among intensive care unit (ICU) family members and registered nurses. HEC retains person/environmental integrity through unfolding of unitary knowledge via exploration of meaning. Additionally, its holistic perspective aligns philosophically with the belief in nursing science as the study of caring in the human health experience, endorsing both the mutuality of the nurse/client relationship and pattern recognition's capacity to inspire transformational growth. The study was performed in an eighteen bed medical ICU in the northeast region of the United States. This unit's design includes an integrated critical/palliative care model. Exploration of the study's two research questions was accomplished using the practice and research components of HEC within a sample of eight family members and six registered nurses. Results demonstrated family members' capacity to achieve consciousness expansion within the context of a loved one's critical illness. Registered nurses revealed their ability to steadfastly partner with both patients and families. Repetitive elements distinguished as thematic commonalities were recognized among both family member and registered nurse participants. Additionally, thematic integration between family members and registered nurses was appreciated. HEC was found to offer unique insights into caring relationships between ICU family members and registered nurses. / Thesis (PhD) — Boston College, 2014. / Submitted to: Boston College. Connell School of Nursing. / Discipline: Nursing.
|
24 |
Cohomologia e propriedades estocásticas de transformações expansoras e observáveis lipschitzianos / Cohomology and stochastics properties of expanding maps and lipschitzians observablesLima, Amanda de 20 March 2007 (has links)
Provamos o Teorema do Limite Central para transformações expansoras por pedaços em um intervalo e observáveis com variação limitada. Utilizamos a abordagem desenvolvida por R. Rousseau-Egele, como apresentada por A. Broise. O método da demonstração se baseia no estudo de pertubações do operador de transferência de Ruelle-Perron-Frobenius. Uma contribuição original é dada no último capítulo, onde provamos que, para transformações markovianas expansoras, todos os observáveis não constantes, contínuos e com variação limitada não são infinitamente cohomólogos à zero, generalizando um resultado de Bamón, Rivera-Letelier, Urzúa and Kiwi para observáveis lipschitzianos e transformações \'z POT. n\' . A demonstração se baseia na teoria dos operadores de Ruelle-Perron-Frobenius desenvolvida nos capítulos anteriores / We prove the Central Limit Theorem for piecewise expanding interval transformations and observables with bounded variation, using the approach of J.Rousseau-Egele as described by A. Broise. This approach makes use of pertubations of the so-called Ruelle-Perron-Frobenius transfer operator. An original contribution is given in the last chapter, where we prove that for Markovian expanding interval maps all observables which are non constant, continuous and have bounded variation are not infinitely cohomologous with zero, generalizing a result by Bamón, Rivera-Letelier, Urzúa and Kiwi for Lipschitzian observables and the transformations \'z POT. n\' . Our demosntration uses the theory of Ruelle-Perron-Frobenius operators developed in the previos chapters
|
25 |
Multi-channel Sales Distribution- Should Online Retailers Expand Offline?SJÖLANDER, REBECCA, LANGEGGER, LENA January 2013 (has links)
The retail industry is in a motion of fascinating developments, it can be currently alleged that it is one of the most innovating fields within research. Online retailing in particular has experienced major changes in recent years. However, these developments are slowing down as online retailing is entering a mature state. Online fashion companies now have to consider new strategies to further evolve their businesses. Innovative Online companies have taken action towards a multi-channel sales distribution strategy, some have even gone as far as adopting an omni-channel approach. With that statement, this study attempts to add different insights to the topic by focusing on the issue of online expanding offline from a company point of view. Empirical data included company and industry specialist interviews as well as a questionnaire that was used for pre-research and developing propositions. This resulted in three findings that involved both advantages and disadvantages in Online fashion retailers evolving offline. Firstly, whether or not an Online fashion company should expand offline depends entirely on the ambition level and type of company interviewed. Secondly, it can be concluded that Online fashion companies have the desire to keep their current business model, though they cannot continue with the same strategy in the long run. Lastly, if an offline presence is established, a traditional expansion strategy cannot be used, but innovative concepts are required (mixed realities). If this strategy is taken seriously, expanding offline could be the solution to reach a higher level of online retailing and company success. / Program: Master Programme in Fashion Management
|
26 |
Transversal families of piecewise expanding maps / Famílias transversais de transformações expansoras por pedaçosLima, Amanda de 07 May 2015 (has links)
Let t:[a,b] → ft be a C2 family of \"good\" C4 e piecewise expanding unimodal maps, with a critical point c, that is transversal to the topological classes of such maps. Given a lipchitzian observable ∅, consider the function ℛ∅(t)=∫∅dµt, where µt is the unique bsolutely continuous invariant probability of ft. We show a central limit theorem for the modulus of continuity of ℝ∅, that is limh→0m{t ∈ [a,b] : t + h ∈ [a,b] e 1/(Ψ(t)(-log|h|)½)((ℛ∅(t + h) - ℛ∅(t))/h) ≤ y} converges to 1/(2π)½ ∫y-∞e-s2/2ds. Now, let us consider a C2+ε expanding map f : 𝕊1 → 𝕊1 and a C1+ε periodic function v : 𝕊1 → ℝ. We show that the unique bounded solution of the twisted cohomological equation v(x) = α(f(x)) - Df(x)α(x) is either of class C1+ε or nowhere differentiable. We also prove that if α is nowhere differentiable, them the modulus of continuity of α satisfies a central limit theorem, that is, there is α > 0 such that limh→0µ{x : (α(x + h) - α(x))/(σ𝓁h(-log|h|)½) ≤ y} = 1/(2π)½ ∫y-∞e-t2/2dt, where µ is the absolutely continuous invariant probability of f. / Seja t:[a,b] → ft uma família C2 \"boa\" de transformações unimodais expansoras por pedaços com um ponto crítico c, que é transversal às classes topológicas de tais transformações. Dado um observável lipschitziano ∅, considere a função ℛ∅(t)=∫∅dµt, onde µt é a única probabiidade invariante absolutamente contínua de ft. Mostramos um teorema do limite central para o módulo de continuidade de ℝ∅, isto é limh→0m{t ∈ [a,b] : t + h ∈ [a,b] e 1/(Ψ(t)(-log|h|)½)((ℛ∅(t + h) - ℛ∅(t))/h) ≤ y} converge para 1/(2π)½ ∫y-∞e-s2/2ds. Vamos considerar agora f : 𝕊1 → 𝕊1 uma transformação expansora de classe C2+ε e v : 𝕊1 → ℝ uma função periódica de classe C1+ε. Mostramos que a única solução limitada da equação cohomológica torcida v(x) = α(f(x)) - Df(x)α(x) ou é de classe C1+ε ou não possui derivada em ponto algum. Mostramos também que se α não possui derivada em ponto algum, então o módulo de continuidade de α satisfaz um teorema do limite central, isto é, existe α > 0 tal que limh→0µ{x : (α(x + h) - α(x))/(σ𝓁h(-log|h|)½) ≤ y} = 1/(2π)½ ∫y-∞e-t2/2dt, onde µ é a probabilidade invariante absolutamente contínua associada a f.
|
27 |
Medidas SRB para Atratores Hiperbólicos / SRB Measures for Hyperbolic AttractorsCARVALHO, Péricles Rafael Pavão 02 May 2017 (has links)
Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-07-17T12:51:37Z
No. of bitstreams: 1
Pericles Carvalho.pdf: 1223900 bytes, checksum: f4ce61e56294f3bb3b3e192efa2993f2 (MD5) / Made available in DSpace on 2017-07-17T12:52:05Z (GMT). No. of bitstreams: 1
Pericles Carvalho.pdf: 1223900 bytes, checksum: f4ce61e56294f3bb3b3e192efa2993f2 (MD5)
Previous issue date: 2017-05-02 / This paper begins with the definition of SRB measures, and the introduction of several
concepts in ergodic theory necessary for the development of the presented results. We
prove the existence and uniqueness of SRB measures for uniformly expanding transformations in compact connected manifolds whose Jacobian is H¨older continuous. Then,
we present the definition of hyperbolic sets, hyperbolic attractors and their respective
fundamental properties. As a main result, we prove the existence of SRB measures for
hyperbolic attractors contained in compact manifolds, and its uniqueness if the hyperbolic
attractor is transitive. First, it is shown the existence of invariant measures absolutely
continuous along the unstable foliation. Then, we note that the restriction of this measure over certain subsets have the SRB property. Using the transitivity of the hyperbolic
attractor, it is shown that there exists a unique subset such that this restriction is an
SRB measure. We conclude that the system supports a unique SRB measure. / Este trabalho inicia-se com a definição de medida SRB, e a apresentação de diversos conceitos da teoria ergódica importantes para o desenvolvimento dos resultados apresentados.
É demonstrada a existência e unicidade de medidas SRB para transformações expansoras
em variedades compactas e conexas cujo jacobiano é Holder. Em seguida, apresenta-se
a definição de conjuntos hiperbólicos, atratores hiperbólicos e suas respectivas propriedades fundamentais. Como resultado principal, é demonstrada a existência de medidas SRB
para atratores hiperbólicos, bem como sua unicidade para o caso de atratores hiperbólicos
transitivos, ambos dentro de variedades compactas. Primeiramente, é mostrado que existem medidas invariantes absolutamente contínuas ao longo da folheação instável. Em
seguida, verifica-se que a restrição desta medida sob determinados conjuntos possuem a
propriedade SRB. Utilizando a transitividade do atrator hiperbólico, mostra-se que existe
um único conjunto tal que esta restrição seja uma medida SRB. Conclui-se que o sistema
admite uma única medida SRB.
|
28 |
Expanding Community Partnership Grants: Johnson City Brand AuditKridler, Jamie Branam 01 February 2002 (has links)
No description available.
|
29 |
Fundamental aspects of the expansion of the universe and cosmic horizonsDavis, Tamara Maree, Physics, Faculty of Science, UNSW January 2004 (has links)
We use standard general relativity to clarify common misconceptions about fundamental aspects of the expansion of the Universe. In the context of the new standard Lambda-CDM cosmology we resolve conflicts in the literature regarding cosmic horizons and the Hubble sphere (distance at which recession velocity equals c) and we link these concepts to observational tests. We derive the dynamics of a non-comoving galaxy and generalize previous analyses to arbitrary FRW universes. We also derive the counter-intuitive result that objects at constant proper distance have a non-zero redshift. Receding galaxies can be blueshifted and approaching galaxies can be redshifted, even in an empty universe for which one might expect special relativity to apply. Using the empty universe model we demonstrate the relationship between special relativity and Friedmann-Robertson-Walker cosmology. We test the generalized second law of thermodynamics (GSL) and its extension to incorporate cosmological event horizons. In spite of the fact that cosmological horizons do not generally have well-defined thermal properties, we find that the GSL is satisfied for a wide range of models. We explore in particular the relative entropic "eworth"e of black hole versus cosmological horizon area. An intriguing set of models show an apparent entropy decrease but we anticipate this apparent violation of the GSL will disappear when solutions are available for black holes embedded in arbitrary backgrounds. Recent evidence suggests a slow increase in the fine structure constant over cosmological time scales. This raises the question of which fundamental quantities are truly constant and which might vary. We show that black hole thermodynamics may provide a means to discriminate between alternative theories invoking varying constants, because some variations in the fundamental "econstants"e could lead to a violation of the generalized second law of thermodynamics.
|
30 |
Expanding a 2 x 2 determinant (basket weave method)Frye, John, Rattanawangcharoen, Nipon, Miller, Janice, Short, Heather, Distance Education, University of Manitoba 08 November 2005 (has links)
This flash animation demonstrates the expansion of a 2 x 2 determinant by the basket weave method. It includes audio instruction and a short self-test at the end of the animation.
|
Page generated in 0.0732 seconds