A new approach to turbulence modeling

A new approach to Reynolds averaged turbulence modeling is proposed which has a computational cost comparable to two equation models but a predictive capability approaching that of Reynolds stress transport models. This approach isolates the crucial information contained within the Reynolds stress tensor, and solves transport equations only for a set of 'reduced' variables. In this work, Direct Numerical Simulation (DNS) data is used to analyze the nature of these newly proposed turbulence quantities and the source terms which appear in their respective transport equations. The physical relevance of these quantities is discussed and some initial modeling results for turbulent channel flow are presented

Non-local modulation of the energy cascade in broad-band forced turbulence

Classically, large-scale forced turbulence is characterized by a transfer of energy from large to small scales via nonlinear interactions. We have investigated the changes in this energy transfer process in broad-band forced turbulence where an additional perturbation of flow at smaller scales is introduced. The modulation of the energy dynamics via the introduction of forcing at smaller scales occurs not only in the forced region but also in a broad range of length-scales outside the forced bands due to non-local triad interactions. Broad-band forcing changes the energy distribution and energy transfer function in a characteristic manner leading to a significant modulation of the turbulence. We studied the changes in this transfer of energy when changing the strength and location of the small-scale forcing support. The energy content in the larger scales was observed to decrease, while the energy transport power for scales in between the large and small scale forcing regions was enhanced. This was investigated further in terms of the detailed transfer function between the triad contributions and observing the long-time statistics of the flow. The energy is transferred toward smaller scales not only by wavenumbers of similar size as in the case of large-scale forced turbulence, but by a much wider extent of scales that can be externally controlled.Comment: submitted to Phys. Rev. E, 15 pages, 18 figures, uses revtex4.cl

Evaluation of Noise Radiation Mechanisms in Turbulent Jets

Data from the direct numerical simulation (DNS) of a turbulent, compressible (Mach = 1.92) jet has been analyzed to investigate the process of sound generation. The overall goals are to understand how the different scales of turbulence contribute to the acoustic field, and to understand the role that linear instability waves play in the noise produced by supersonic turbulent jets. Lighthill’s acoustic analogy was used to predict the radiate sound from turbulent source terms computed from the DNS data. Preliminary computations (for the axisymmetric mode of the acoustic field) showgood agreement between the acoustic field determined from DNS and acoustic analogy. Further work is needed to refine the calculations and investigate the source terms. Work was also begun to test the validity of linear stability wave models of sound generation in supersonic jets. An adjoint-based method was developed to project the DNS data onto the most unstable linear stability mode at different streamwise positions. This will allow the evolution of the wave and its radiated acoustic field, determined by solving the linear equations, to be compared directly with the evolution of the near and far-field fluctuations in the DNS

Digital arts in the context of traditional and contemporary creative arts training and practices

The first idea of "Art Education" came to my mind when I wrote M.A. thesis entitled:“ The Role of Art in Training and Teaching Children 6-11”, Ten years ago. I was eager to enhance my study to new planning methods of Art universities. The objective of this idea was to open up our cultural institutions to the wider community, to promote learning and to extend the reach of new technologies. So, as a PhD student I liked to work on the idea of values and the hope for development. I left all my past behind to enliven my ambition in the way of innovative art. In the world of communication and digital, I was looking for a way to connect human‟s intellectual values and global digital. I tried to perceive the reality of human‟s nature despite the extraordinary progress in computer and its components. Therefore, it is now appropriate to move our attention to what we might do as teachers in higher education to evaluate the quality of our own work, with the key aim of improving the quality of students learning. Because, a teacher has a unique role, requiring the integration of teaching skills and capability to take an active role in curriculum support, design and implementation. I had so many interviews with many digital artists around the world which made me to question myself: Where am I standing now? What do I intend my artwork to impart? As the global communication has brought artist to communicate globally they intend to suggest the new thinking and new form of art. It is no longer art for art but art for communication and conveys a meaning to observers. Regarding to Oliver Wedell who interprets the best of a book he found, can also be a good expression for me in art: "The best of a book is not the thought which it contains, but the thought which it suggests; just as the charm of music dwells not in the tones but in the echoes of our hearts." Oliver Wendell Holmes (1809-1894), American physician and writer. (Wendell Holmes). This thesis has set out to provide a review of progress in the British universities post 60s. There was historical evidence of this tendency going back into the 19th century, when colleges founded to serve the educational needs of the growing industrial cities turned into the technological universities. The intensity of the certain of new system in England was occurred after World War II. Following post war concern about the need for technical education, and deciding to establish some colleges linked to industry. Indeed, the evaluation of new industry and demanding for reformation, become one of the most important goals in England in those days. Academic atmosphere became institutionalised on policy for technical education in 1950s and 1960s. Appendix 1 contains the main intention to explore the progressive movement of higher education in England. However, It was not the aim to provide a comprehensive theory of the history of education but, in short, I have narrowed my attention to the history of art universities in England since 18th century up to now. So, appendix II, concentrates on the creation of the new system after the 60s and have explored how and why the process of improvement expanded during that period. Chapter 1 with the subject "Digital Art and Iranian Education" has addressed approaches to teaching for creativity in art and illustrates how they can provide rich opportunities for students to discover experience and develop their skills in creative area. The questions here: How can creativity be communicated through teaching? Do we have a specific language for creativity in art? How can we explain the importance of creativity in art? How can teachers make the teaching process itself more creative? would be an overview of teaching and learning process. As it can be an important factor for teachers to know and demonstrate “when”, “where” and “which” language can be matched by creative subject material to avoid creative problem. Actually, creative problem solving depends on using the right tools such as, text, graphics, picture, video, links, searching, random scanning, backtracking, multiple windows, with programmable access and control of other resources such as, spreadsheets, databases, CAD, CD-ROMs, video discs, audio discs, tricks, procedures or methods of analysis. In some cases new tools and methods of analysis must be developed from scratch by the inventor before a problem can be solved and in other cases special tools and procedures must be developed to take the final critical step of enabling successful commercial applications after a university education. Recent technological advances in the arts have created the possibility of new ways of teaching and learning. Identifying successful strategies and techniques for enabling universities to advance is a critical step towards making these goals a reality. This chapter analyse the following conceptual approaches as key issues: Restructuring curriculum and policy in Iranian arts faculties, promoting faculty development and students‟ learning in the context of global standards. More specific issues included: Is there a need for a standard model to deliver university goals? How can we adapt the curriculum? What do we want from creativity and how can we be more creative? Chapter 2 discusses the quality of teaching and learning, resulting in improvements throughout undergraduate education. Therefore, Iranian educational context needs to be considered. I have argued that to increase faculty members‟ effectiveness, the existing competitive, individualistic college structure needs to be transformed to provide a collaborative and innovative environment where the use of computers could emerge as a new practice area. Chapter 3 represents that creative use of computers in digital art is important in learning and teaching. This chapter gives an account of the author‟s experiences in digital printmaking, not just as pieces of art work, but also to develop teaching and learning strategies for Iranian art universities. Chapter 4 states that the development of a professional digital art practice has been an essential task faced by many creative professionals today. The application of digital technologies discussed in this chapter is: What is needed in order to identify a dynamic practice and critical debate relative to educational contexts? How can we visualize the practice and theory of digitalisation? In particular, what is the nature of the collaboration that explores new models of working and practice relevant to the discovery of new methods in future? Indeed, the intersection between digital paintings, the physical body, and multimedia in collaboration with music and video art is one that this chapter discusses as a challenging teaching exemplar in forming learning values. The result promotes a new fine art context that breaks the crossing between the arts. Chapter 5 reveals the world of modern physics and the reality of our mind and our conscious self. The study of quantum physics is the further aim to develop artists‟ consciousness and inner expression for the concept of body energy and interactivity in chapter 6. Chapter 6 considers the hidden values to learn how to focus well on mind throughout the physical body. The collaborative digital art practice has analysed the intellectual activity and produced an interactive visual arts. The study of human being fused my imagination to see and express body in a new form of art as my final project. Chapter 7 examines and explores the idea of using digital art as a form of multimedia project and the opportunity of developing new techniques in performance. These explorations need to develop new tools to facilitate the emerging concept of the higher spatial dimensions, human body and their relationship between art and technology. The intention of this chapter, as a closing chapter, was to suggest a developing a programme, as a short experiential artwork to model a virtual form of the body and to explore the nature of consciousness in the world of the imagination.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Intranasal administration of RSV antigen-expressing MCMV elicits robust tissue-resident effector and effector memory CD8+ T cells in the lung

Cytomegalovirus vectors are promising delivery vehicles for vaccine strategies that aim to elicit effector CD8+ T cells. To determine how the route of immunization affects CD8+ T cell responses in the lungs of mice vaccinated with a murine cytomegalovirus vector expressing the respiratory syncytial virus matrix (M) protein, we infected CB6F1 mice via the intranasal or intraperitoneal route and evaluated the M-specific CD8+ T cell response at early and late time points. We found that intranasal vaccination generated robust and durable tissue-resident effector and effector memory CD8+ T cell populations that were undetectable after intraperitoneal vaccination. The generation of these antigen-experienced cells by intranasal vaccination resulted in earlier T cell responses, interferon gamma secretion, and viral clearance after respiratory syncytial virus challenge. Collectively, these findings validate a novel approach to vaccination that emphasizes the route of delivery as a key determinant of immune priming at the site of vulnerability

Computational issues and algorithm assessment for shock/turbulence interaction problems

The paper provides an overview of the challenges involved in the computation of flows with interactions between turbulence, strong shockwaves, and sharp density interfaces. The prediction and physics of such flows is the focus of an ongoing project in the Scientific Discovery through Advanced Computing (SciDAC) program. While the project is fundamental in nature, there are many important potential applications of scientific and engineering interest ranging from inertial confinement fusion to exploding supernovae. The essential challenges will be discussed, and some representative numerical results that highlight these challenges will be shown. In addition, the overall approach taken in this project will be outlined

Inlet conditions for large eddy simulation of gas-turbine swirl injectors

Copyright © 2008 American Institute of Aeronautics and AstronauticsIn this paper, we present a novel technique for generating swirl inlets for large eddy simulation. The velocity a short distance downstream of the inlet to the main domain is sampled and the flow velocity data are reintroduced back into the domain inlet, creating an inlet section integrated into the main domain in which turbulence can develop. Additionally, variable artificial body forces and velocity corrections are imposed in this inlet section, with feedback control to force the flow toward desired swirl, mean, and turbulent profiles. The method was applied to flow in an axisymmetric sudden expansion, with and without swirl at the inlet, and compared against experimental and literature large eddy simulation data and against similar results in the literature. The method generates excellent results for this case and is elegant and straightforward to implement

Evaluation of Noise Radiation Mechanisms in Turbulent Jets

Data from the direct numerical simulation (DNS) of a turbulent, compressible (Mach = 1.92) jet has been analyzed to investigate the process of sound generation. The overall goals are to understand how the different scales of turbulence contribute to the acoustic field, and to understand the role that linear instability waves play in the noise produced by supersonic turbulent jets. Lighthill’s acoustic analogy was used to predict the radiate sound from turbulent source terms computed from the DNS data. Preliminary computations (for the axisymmetric mode of the acoustic field) showgood agreement between the acoustic field determined from DNS and acoustic analogy. Further work is needed to refine the calculations and investigate the source terms. Work was also begun to test the validity of linear stability wave models of sound generation in supersonic jets. An adjoint-based method was developed to project the DNS data onto the most unstable linear stability mode at different streamwise positions. This will allow the evolution of the wave and its radiated acoustic field, determined by solving the linear equations, to be compared directly with the evolution of the near and far-field fluctuations in the DNS

Rationale and design of a multicenter Chronic Kidney Disease (CKD) and at-risk for CKD electronic health records-based registry: CURE-CKD.

BACKGROUND: Chronic kidney disease (CKD) is a global public health problem, exhibiting sharp increases in incidence, prevalence, and attributable morbidity and mortality. There is a critical need to better understand the demographics, clinical characteristics, and key risk factors for CKD; and to develop platforms for testing novel interventions to improve modifiable risk factors, particularly for the CKD patients with a rapid decline in kidney function. METHODS: We describe a novel collaboration between two large healthcare systems (Providence St. Joseph Health and University of California, Los Angeles Health) supported by leadership from both institutions, which was created to develop harmonized cohorts of patients with CKD or those at increased risk for CKD (hypertension/HTN, diabetes/DM, pre-diabetes) from electronic health record data. RESULTS: The combined repository of candidate records included more than 3.3 million patients with at least a single qualifying measure for CKD and/or at-risk for CKD. The CURE-CKD registry includes over 2.6 million patients with and/or at-risk for CKD identified by stricter guide-line based criteria using a combination of administrative encounter codes, physical examinations, laboratory values and medication use. Notably, data based on race/ethnicity and geography in part, will enable robust analyses to study traditionally disadvantaged or marginalized patients not typically included in clinical trials. DISCUSSION: CURE-CKD project is a unique multidisciplinary collaboration between nephrologists, endocrinologists, primary care physicians with health services research skills, health economists, and those with expertise in statistics, bio-informatics and machine learning. The CURE-CKD registry uses curated observations from real-world settings across two large healthcare systems and has great potential to provide important contributions for healthcare and for improving clinical outcomes in patients with and at-risk for CKD

Dynamic Profiling of β-Coronavirus 3CL Mpro Protease Ligand-Binding Sites

β-coronavirus (CoVs) alone has been responsible for three major global outbreaks in the 21st century. The current crisis has led to an urgent requirement to develop therapeutics. Even though a number of vaccines are available, alternative strategies targeting essential viral components are required as a backup against the emergence of lethal viral variants. One such target is the main protease (Mpro) that plays an indispensable role in viral replication. The availability of over 270 Mpro X-ray structures in complex with inhibitors provides unique insights into ligand-protein interactions. Herein, we provide a comprehensive comparison of all nonredundant ligand-binding sites available for SARS-CoV2, SARS-CoV, and MERS-CoV Mpro. Extensive adaptive sampling has been used to investigate structural conservation of ligand-binding sites using Markov state models (MSMs) and compare conformational dynamics employing convolutional variational auto-encoder-based deep learning. Our results indicate that not all ligand-binding sites are dynamically conserved despite high sequence and structural conservation across β-CoV homologs. This highlights the complexity in targeting all three Mpro enzymes with a single pan inhibitor