962 research outputs found

    Methods of determining loads and fiber orientations in anisotropic non-crystalline materials using energy flux deviation

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    An ultrasonic wave is applied to an anisotropic sample material in an initial direction and an angle of flux deviation of the ultrasonic wave front is measured from this initial direction. This flux deviation angle is induced by the unknown applied load. The flux shift is determined between this flux deviation angle and a previously determined angle of flux deviation of an ultrasonic wave applied to a similar anisotropic reference material under an initial known load condition. This determined flux shift is then compared to a plurality of flux shifts of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift

    The Elliptic curves in gauge theory, string theory, and cohomology

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    Elliptic curves play a natural and important role in elliptic cohomology. In earlier work with I. Kriz, thes elliptic curves were interpreted physically in two ways: as corresponding to the intersection of M2 and M5 in the context of (the reduction of M-theory to) type IIA and as the elliptic fiber leading to F-theory for type IIB. In this paper we elaborate on the physical setting for various generalized cohomology theories, including elliptic cohomology, and we note that the above two seemingly unrelated descriptions can be unified using Sen's picture of the orientifold limit of F-theory compactification on K3, which unifies the Seiberg-Witten curve with the F-theory curve, and through which we naturally explain the constancy of the modulus that emerges from elliptic cohomology. This also clarifies the orbifolding performed in the previous work and justifies the appearance of the w_4 condition in the elliptic refinement of the mod 2 part of the partition function. We comment on the cohomology theory needed for the case when the modular parameter varies in the base of the elliptic fibration.Comment: 23 pages, typos corrected, minor clarification

    Duality symmetry and the form fields of M-theory

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    In previous work we derived the topological terms in the M-theory action in terms of certain characters that we defined. In this paper, we propose the extention of these characters to include the dual fields. The unified treatment of the M-theory four-form field strength and its dual leads to several observations. In particular we elaborate on the possibility of a twisted cohomology theory with a twist given by degrees greater than three.Comment: 12 pages, modified material on the differentia

    Numerical Simulation and Visualization Models of Stress Wave Propagation Graphite/Epoxy Composites

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    Within the last ten years there has been a renewed interest in simulation of stress wave propagation because of the availability of fast supercomputers with large memory capabilities [1,2,3]. Only recently have a few investigators [4,5] applied these simulations to problems where elastic anisotropy was included as a major factor. The massive output of results from these simulations, together with the added complexity of coupled phenomena that uniquely exist for a given anisotropy, defies intuition. To grasp the significance of these simulations requires scientific visualization [6] of these complex physical phenomena. Such visualizations often require a movie format to better understand the physics of particular problems [7]. In this study we simulated the experimental measurement of a shift in the quasi-transverse bulk wave propagation in an off-axis unidirectional graphite/epoxy composite in plane strain [8]. The purpose of the simulation was to aid the nondestructive evaluation engineer in designing an acoustic array to improve the measurement of the shift in the QT wave propagation direction [9]. Previously a finite element model [5] was used to simulate this measurement. In this study we demonstrate the advantages of using a finite difference model to simulate this experiment and, with special visual aids, observe the physics

    M-theory and Characteristic Classes

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    In this note we show that the Chern-Simons and the one-loop terms in the M-theory action can be written in terms of new characters involving the M-theory four-form and the string classes. This sheds a new light on the topological structure behind M-theory and suggests the construction of a theory of `higher' characteristic classes.Comment: 8 pages. Error in gravitational term fixed; minor corrections; reference and acknowledgement adde

    Anglican Eucharistic Liturgy: a Church-Planting Hope for the Post-Christian Culture of the Pacific Northwest

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    The question addressed in this dissertation may be stated as follows: 1tJ1l1at hope does Anglican Eucharistic Liturgy bring to the future of church planting within the increasingly post-Christian urban centers of the Pacific Northwest? According to our research of a sample zip code of inner-city Portland, Oregon, only one in four people self-identify with Christianity and less than one in five attend church. Churches are shrinking and closing rapidly and our culture is increasingly defined as post-Christian. The plans of the recent church-planting efforts are losing ground. There is no one-size-fits-all solution, but there is significant evidence that the Anglican Eucharistic Liturgy will speak today, where other strategies have not. In Chapter One, the cultural reality of the Pacific Northwest is described in greater detail, including the specifics of our unique and localized research., which shows this spiritual state in shocking detail. Within this context the Anglican Eucharist will also be explained in greater detail and will foreshadow the solution to come. Chapter Two and Chapter Three lay the global-historical continuity of liturgical worship and forms. Throughout biblical times (Chapter Two) and church history (Chapter Three), by the leading of God, the people of Jehovah have voted again and again, across generations and cultures, that liturgy is meaningful and transcendent. These liturgical forms were defined and solidified from the church\u27s earliest times. In Chapter Four, the essential dance of contextualization is defined. As the church continues to serve and love into post-Christian culture, it must strive to keep the forms and passions of consistent church history, while incarnating the unique and particular voice of each localized context. Chapter Five provides a critique of existing church planting methods. Chapter Six contains our solution. It considers the structural viability of birthing Anglicanism in the western United States and follows with a discussion of the Eucharistic Liturgy in light of post-Christian encounter with truth, post-Christian experience of community and post-Christian Spirituality. Conclusion: the liturgy will speak. Appendix 1 reveals and explains the results of the 97217 survey. Appendix 2 provides creative suggestions for the administration of the Anglican Eucharistic Liturgy in a culture like inner-city Portland, Oregon

    Method of determining load in anisotropic non-crystalline materials using energy flux deviation

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    An ultrasonic wave is applied to an anisotropic sample material in an initial direction and the intensity of the ultrasonic wave is measured on an opposite surface of the sample material by two adjacent receiving points located in an array of receiving points. A ratio is determined between the measured intensities of two adjacent receiving points, the ratio being indicative of an angle of flux deviation from the initial direction caused by an unknown applied load. This determined ratio is then compared to a plurality of ratios of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift

    A mathematical formalism for the Kondo effect in WZW branes

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    In this paper, we show how to adapt our rigorous mathematical formalism for closed/open conformal field theory so that it captures the known physical theory of branes in the WZW model. This includes a mathematically precise approach to the Kondo effect, which is an example of evolution of one conformally invariant boundary condition into another through boundary conditions which can break conformal invariance, and a proposed mathematical statement of the Kondo effect conjecture. We also review some of the known physical results on WZW boundary conditions from a mathematical perspective.Comment: Added explanations of the settings and main result
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