1,188 research outputs found
Advanced 3-D viscous SSME turbine rotor stator CFD algorithms
Current Space Shuttle Main Engine (SSME) high pressure fuel turbopump problems have generated a desire to analyze the flow field of rotating machinery. The status of Computational Fluid Dynamics (CFD) has reached the point that soon the capability to solve unsteady three-dimensional viscous flow fields will be at hand. The work presented involves upgrading the computational efficiency of an operational three-dimensional algorithm. The modifications include algorithm development, algorithm approximation and acceleration, and special coding optimizations. The overall result of these modifications has reduced processing time by nearly 80%
CONDITIONS FOR SOCIAL CHANGE: THEORIZING CRITICAL COMMUNICATION PEDAGOGY WITH/IN THE CLASSROOM USING A LENS OF RELATIONAL SAFETY
AN ABSTRACT OF THE DISSERTATION OF DAVID W. WHITFIELD, for the Doctor of Philosophy degree in COMMUNICATION STUDIES, presented on APRIL 2, 2018, at Southern Illinois University Carbondale. TITLE: CONDITIONS FOR SOCIAL CHANGE: THEORIZING CRITICAL COMMUNICATION PEDAGOGY WITH/IN THE CLASSROOM USING A LENS OF RELATIONAL SAFETY MAJOR PROFESSOR: Dr. Sandra Pensoneau-Conway Using the ten commitments of Critical Communication Pedagogy (CCP) as a grounding perspective, this research project investigates the teacher-student relational dynamic with an inquiry into the degree of safety students and teachers perceive in their shared relationship. Relational safety is a new term being introduced into the literature on reflexive and critical teaching practices. It is foregrounded in the belief that the classroom is a microcosm of the larger world and therefore can be a site of inquiry and interruption of mundane communication practices that may be oppressive and which might otherwise go unquestioned (Fassett & Warren, 2007). A combination of three methods were utilized. Classroom observations were conducted in all four face-to-face summer sections of the introductory public speaking course from the university\u27s core curriculum. These observations were used to inform the questions used to interview participants. The data collected were from three (student) focus groups, four graduate teaching assistants (GTAs) interviews, and 23 individual student interviews. Findings revealed five major themes that are salient for the emergence and development of a teaching practice which nurtures feelings of safety in the teacher-student relationship: 1) affirmation; 2) dialogic worldview; 3) attention to bodies in space; 4) a balanced approach to humor, self-disclosure, and feedback; 5) the class evolves into a community of care. The dissertation concludes with a reminder that while social change is the ultimate goal of a critical, reflexive teaching practice that is future-oriented, teachers must always remain grounded in hope. Relational safety can emerge when critical educators embrace a belief that when teachers model reflexive communicative practices to/for their students, in turn they create a space for incremental shifts in language choices, critical discourse, and reflexive thinking that will evoke a desire in others to advocate for social change, communicate across cultural differences, and celebrate diversit
A performer\u27s guide to Virgil Thomson\u27s Five Songs from William Blake
Though perhaps his most well-known vocal works might be his operas, Four Saints in Three Acts and The Mother of Us All, American composer Virgil Thomson (1896-1989) did write nearly seventy songs for voice and piano, including several important song cycles. One of these cycles, the Five Songs from William Blake, represents an impressive composition for the baritone voice. Unfortunately, much of the previous scholarship about Thomson did not award these Blake songs adequate attention, nor was it able to draw upon many of the primary sources about Thomson’s life and work that are now available. The purpose of this study is to amend these omissions with a specific guide for performers, combining recent scholarship, an analysis of Thomson’s setting of Blake’s text to music, and a consideration of the vocal merits and difficulties of Thomson’s vocal writing into one helpful document. Chapter 1 presents a brief biographical portrait of the composer, with special emphasis on Thomson’s interest in William Blake, and addresses Thomson’s theories about composing for the voice. Chapter 2 begins with a general introduction to the Five Songs from William Blake and a history of their critical reception. Then, this chapter undertakes a detailed examination of the pieces in order to assess Thomson’s specific musical and vocal choices in setting the text. The elements of this analysis include: meter/structure of the poem, meter/structure of the music, vocal range and tessitura, expressive markings, vocal challenges, and interpretive suggestions. Finally, this document presents a conclusion that considers Thomson\u27s overall significance as a vocal composer and the relevance of the Five Songs from William Blake to this discussion. In addition, the document includes two appendices. Appendix A contains the complete text of the five William Blake poems that Thomson chose to set to music. Appendix B provides a selected discography of the Five Songs from William Blake
Three-dimensional multigrid algorithms for the flux-split Euler equations
The Full Approximation Scheme (FAS) multigrid method is applied to several implicit flux-split algorithms for solving the three-dimensional Euler equations in a body fitted coordinate system. Each of the splitting algorithms uses a variation of approximate factorization and is implemented in a finite volume formulation. The algorithms are all vectorizable with little or no scalar computation required. The flux vectors are split into upwind components using both the splittings of Steger-Warming and Van Leer. The stability and smoothing rate of each of the schemes are examined using a Fourier analysis of the complete system of equations. Results are presented for three-dimensional subsonic, transonic, and supersonic flows which demonstrate substantially improved convergence rates with the multigrid algorithm. The influence of using both a V-cycle and a W-cycle on the convergence is examined
Nonlinear (time domain) and linearized (time and frequency domain) solutions to the compressible Euler equations in conservation law form
Two linearized solvers (time and frequency domain) based on a high resolution numerical scheme are presented. The basic approach is to linearize the flux vector by expressing it as a sum of a mean and a perturbation. This allows the governing equations to be maintained in conservation law form. A key difference between the time and frequency domain computations is that the frequency domain computations require only one grid block irrespective of the interblade phase angle for which the flow is being computed. As a result of this and due to the fact that the governing equations for this case are steady, frequency domain computations are substantially faster than the corresponding time domain computations. The linearized equations are used to compute flows in turbomachinery blade rows (cascades) arising due to blade vibrations. Numerical solutions are compared to linear theory (where available) and to numerical solutions of the nonlinear Euler equations
A Study of the Effects of Relative Humidity on Small Particle Adhesion to Surfaces
Ambient dust ranging in size from less than one micron up to 140 microns was used as test particles. Relative humidities of 33% to 100% were used to condition test surfaces after loading with the test particles. A 20 psi nitrogen blowoff was used as the removal mechanism to test for particle adhesion. Particles were counted before and after blowoff to determine retention characteristics. Particle adhesion increased drastically as relative humidity increased above 50%. The greatest adhesion changes occurred within the first hour of conditioning time. Data are presented for total particle adhesion, for particles 10 microns and larger, and 50 microns and larger
Neuronal human BACE1 knock-in induces systemic diabetes in mice
Acknowledgements The authors thank S. Tammireddy (Diabetes and Cardiovascular Science, University of the Highlands and Islands, Inverness, UK) for technical support with the lipidomics component. Funding We would like to thank R. Simcox, Romex Oilfield Chemicals, for financial support for KP, and acknowledge additional contributions from the Scottish Alzheimer’s Research UK network for the lipidomics work. The College of Life Science and Medicine, University of Aberdeen, sponsored the imaging study. MD was funded by British Heart Foundation and Diabetes UK; NM was funded by a British Heart Foundation Intermediate Fellowship; KS was funded by a European Foundation for the Study of Diabetes/Lilly programme grant; and RD was funded by an Institute of Medical Sciences PhD studentship.Peer reviewedPublisher PDFPublisher PD
Coverage of Megaprosthesis with Human Acellular Dermal Matrix after Ewing's Sarcoma Resection: A Case Report
A 23-year-old female with Ewing's Sarcoma underwent tibial resection and skeletal reconstruction using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge. Human acellular dermal matrix, (Alloderm, LifeCell, Branchburg, NJ, USA), was used to wrap the skeletal reconstruction. Soft tissue reconstruction was completed with a rotational gastrocnemius muscle flap and skin graft. Despite prolonged immobilization, the patient quickly regained full range of motion of her skeletal reconstruction. Synthetic mesh, tapes and tubes are used to perform capsule reconstruction of megaprosthesis. This paper describes the role of human acellular dermal matrix in capsule reconstruction around a megaprosthesis
Computation of rotor-stator interaction using the Navier-Stokes equations
The numerical scheme presented belongs to a family of codes known as UNCLE (UNsteady Computation of fieLd Equations) as reported by Whitfield (1995), that is being used to solve problems in a variety of areas including compressible and incompressible flows. This derivation is specifically developed for general unsteady multi-blade-row turbomachinery problems. The scheme solves the Reynolds-averaged N-S equations with the Baldwin-Lomax turbulence model
Improved 3-D turbomachinery CFD algorithm
The building blocks of a computer algorithm developed for the time-accurate flow analysis of rotating machines are described. The flow model is a finite volume method utilizing a high resolution approximate Riemann solver for interface flux definitions. This block LU implicit numerical scheme possesses apparent unconditional stability. Multi-block composite gridding is used to orderly partition the field into a specified arrangement. Block interfaces, including dynamic interfaces, are treated such as to mimic interior block communication. Special attention is given to the reduction of in-core memory requirements by placing the burden on secondary storage media. Broad applicability is implied, although the results presented are restricted to that of an even blade count configuration. Several other configurations are presently under investigation, the results of which will appear in subsequent publications
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