Sample records for higher drag research

  1. Body lift, drag and power are relatively higher in large-eared than in small-eared bat species. (United States)

    Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders; Johansson, L Christoffer


    Bats navigate the dark using echolocation. Echolocation is enhanced by external ears, but external ears increase the projected frontal area and reduce the streamlining of the animal. External ears are thus expected to compromise flight efficiency, but research suggests that very large ears may mitigate the cost by producing aerodynamic lift. Here we compare quantitative aerodynamic measures of flight efficiency of two bat species, one large-eared ( Plecotus auritus ) and one small-eared ( Glossophaga soricina ), flying freely in a wind tunnel. We find that the body drag of both species is higher than previously assumed and that the large-eared species has a higher body drag coefficient, but also produces relatively more ear/body lift than the small-eared species, in line with prior studies on model bats. The measured aerodynamic power of P. auritus was higher than predicted from the aerodynamic model, while the small-eared species aligned with predictions. The relatively higher power of the large-eared species results in lower optimal flight speeds and our findings support the notion of a trade-off between the acoustic benefits of large external ears and aerodynamic performance. The result of this trade-off would be the eco-morphological correlation in bat flight, with large-eared bats generally adopting slow-flight feeding strategies. © 2017 The Author(s).

  2. Research on the aerodynamic characteristics of a lift drag hybrid vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Xiaojing Sun


    Full Text Available Compared with a drag-type vertical axis wind turbines, one of the greatest advantages for a lift-type vertical axis wind turbines is its higher power coefficient (Cp. However, the lift-type vertical axis wind turbines is not a self-starting turbine as its starting torque is very low. In order to combine the advantage of both the drag-type and the lift-type vertical axis wind turbines, a lift drag hybrid vertical axis wind turbines was designed in this article and its aerodynamics and starting performance was studied in detail with the aid of computational fluid dynamics simulations. Numerical results indicate that the power coefficient of this lift drag hybrid vertical axis wind turbines declines when the distance between its drag-type blades and the center of rotation of the turbine rotor increases, whereas its starting torque can be significantly improved. Studies also show that unlike the lift-type vertical axis wind turbines, this lift drag hybrid-type vertical axis wind turbines could be able to solve the problem of low start-up torque. However, the installation position of the drag blade is very important. If the drag blade is mounted very close to the spindle, the starting torque of the lift drag hybrid-type vertical axis wind turbines may not be improved at all. In addition, it has been found that the power coefficient of the studied vertical axis wind turbines is not as good as expected and possible reasons have been provided in this article after the pressure distribution along the surfaces of the airfoil-shaped blades of the hybrid turbine was analyzed.

  3. Higher Education Research Digest (United States)

    ACT, Inc., 2017


    This new ACT publication is an annual report offering meaningful research insights for some of the most pressing questions impacting admissions and enrollment practice. In the first release of this report, ACT research sheds light on the following topics: (1) the practice of super-scoring; (2) STEM major choice; (3) factors impacting retention and…

  4. Application and numerical simulation research on biomimetic drag-reducing technology for gas pipelining

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Deyuan; Luo Yuehao; Chen Huawei [Beihang Univ., Beijing (China). School of Mechanical Engineering and Automation


    For the purpose of increasing the transmission capacity of gas pipelines, the internal coating technology has been vastly put into application, and a remarkable benefit has been achieved so far. However, with the reduction of wall roughness, the small convex parts are all completely submerged in the viscous sublayer, the gas pipeline becomes a 'hydraulic smooth pipe', even by smoothing the coating surface further, it is difficult to reduce wall friction. Therefore, in order to increase the transportation capacity on the basis of internal coating, the new methods and technologies should be researched and investigated, and perhaps, the biomimetic drag-reducing technology is a good approach. In this paper, according to the planning parameters of the second pipeline of the West-to-East gas transmission project, the best drag reducing effect grooves are calculated and designed, and based on the characteristics and properties of internal coating (AW-01 epoxy resin), the Pre-Cured Micro- Rolling Technology (PCMRT) is discussed and presented, the rolling equipment is also designed and analyzed, the rolling process can be easily added on the available production line. Aiming at the field operating parameters of the gas pipeline in China, and the drag-reducing effect of the grooved surface is analyzed and discussed comprehensively. In addition, the economic benefit of adopting the biomimetic drag reduction technology is investigated. (orig.)

  5. Feminist Research in Higher Education (United States)

    Ropers-Huilman, Rebecca; Winters, Kelly T.


    This essay provides an overview of feminist methodology and its potential to enhance the study of higher education. Foregrounding the multiple purposes and research relationships developed through feminist research, the essay urges higher education scholars to engage feminist theories, epistemologies, and methods to inform policy, research, and…

  6. Problematizing gender identity from Feminist Research in a Drag King experience

    Directory of Open Access Journals (Sweden)

    Roberto Fernández Droguett


    Full Text Available This paper presents an experience of Feminist Research developed within the course Methodological Innovations in Qualitative Research, taught in the career of Psychology at the University of Chile. The research consisted of a autoethnography of a Drag-King experience developed in three public places in the city of Santiago in Chile, and our purpose here is to discuss the joint between the methodology developed and the feminist epistemological perspective. Based on a collaborative dialogue we analyse some results of this research and the methodological decisions that were taken during the process. The focus of analysis is the creation of an ambiguous identity that stresses the social norms and allows its critical review, while producing at the same time a complex physical and emotional experience that challenges not only to the persons but also the ways of accounting that through specific narratives.

  7. Ethics in Higher Education Research (United States)

    Parsell, Mitch; Ambler, Trudy; Jacenyik-Trawoger, Christa


    Many educational researchers have experienced challenges in obtaining ethics approval. This article explores some of the reasons why this is the case, looking specifically at the participatory action research methodology. The authors' experience of seeking ethics approval for a project intended to introduce peer review as an enhancement process is…

  8. Discipline and Methodology in Higher Education Research (United States)

    Tight, Malcolm


    Higher education research is a multidisciplinary field, engaging researchers from across the academy who make use of a wide range of methodological approaches. This article examines the relation between discipline and methodology in higher education research, analysing a database of 567 articles published in 15 leading higher education journals…

  9. Air Layer Drag Reduction (United States)

    Ceccio, Steven; Elbing, Brian; Winkel, Eric; Dowling, David; Perlin, Marc


    A set of experiments have been conducted at the US Navy's Large Cavitation Channel to investigate skin-friction drag reduction with the injection of air into a high Reynolds number turbulent boundary layer. Testing was performed on a 12.9 m long flat-plate test model with the surface hydraulically smooth and fully rough at downstream-distance-based Reynolds numbers to 220 million and at speeds to 20 m/s. Local skin-friction, near-wall bulk void fraction, and near-wall bubble imaging were monitored along the length of the model. The instrument suite was used to access the requirements necessary to achieve air layer drag reduction (ALDR). Injection of air over a wide range of air fluxes showed that three drag reduction regimes exist when injecting air; (1) bubble drag reduction that has poor downstream persistence, (2) a transitional regime with a steep rise in drag reduction, and (3) ALDR regime where the drag reduction plateaus at 90% ± 10% over the entire model length with large void fractions in the near-wall region. These investigations revealed several requirements for ALDR including; sufficient volumetric air fluxes that increase approximately with the square of the free-stream speed, slightly higher air fluxes are needed when the surface tension is reduced, higher air fluxes are required for rough surfaces, and the formation of ALDR is sensitive to the inlet condition.

  10. Mapping Global Research on International Higher Education (United States)

    Kuzhabekova, Aliya; Hendel, Darwin D.; Chapman, David W.


    The purpose of the study is to map global research in international higher education. Specifically, the study uses bibliometric and social network analysis methods to identify key individuals, institutions, countries, and disciplines contributing to research in international higher education and to investigate patterns of connectivity among…

  11. Drag Reduction by Laminar Flow Control

    Directory of Open Access Journals (Sweden)

    Nils Beck


    Full Text Available The Energy System Transition in Aviation research project of the Aeronautics Research Center Niedersachsen (NFL searches for potentially game-changing technologies to reduce the carbon footprint of aviation by promoting and enabling new propulsion and drag reduction technologies. The greatest potential for aerodynamic drag reduction is seen in laminar flow control by boundary layer suction. While most of the research so far has been on partial laminarization by application of Natural Laminar Flow (NLF and Hybrid Laminar Flow Control (HLFC to wings, complete laminarization of wings, tails and fuselages promises much higher gains. The potential drag reduction and suction requirements, including the necessary compressor power, are calculated on component level using a flow solver with viscid/inviscid coupling and a 3D Reynolds-Averaged Navier-Stokes (RANS solver. The effect on total aircraft drag is estimated for a state-of-the-art mid-range aircraft configuration using preliminary aircraft design methods, showing that total cruise drag can be halved compared to today’s turbulent aircraft.

  12. Discipline and Theory in Higher Education Research (United States)

    Tight, Malcolm


    Higher education research is, by its nature, rather an introspective field of study. It is also highly dispersed within and beyond the academy: inherently, therefore, it is a multidisciplinary field of study. An analysis of 567 articles published in 15 leading higher education journals in 2010 demonstrates both the breadth of interest in higher…

  13. Research and Planning for Higher Education. (United States)

    Fenske, Robert H., Ed.; Staskey, Paul J., Ed.

    Forty-four papers are collected in this volume and categorized: invited papers on research and planning for higher education; organizational analysis; finance and resource allocation; program and outcomes analysis; modeling; evaluation; and studies of faculty and students. Abstracts of additional papers are included. (MSE)

  14. Body lift, drag and power are relatively higher in large-eared than in small-eared bat species

    DEFF Research Database (Denmark)

    Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders


    Bats navigate the dark using echolocation. Echolocation is enhanced by external ears, but external ears increase the projected frontal area and reduce the streamlining of the animal. External ears are thus expected to compromise flight efficiency, but research suggests that very large ears may mi....... The result of this trade-off would be the eco-morphological correlation in bat flight, with large-eared bats generally adopting slow-flight feeding strategies....

  15. Multimodal Landscaping in Higher Education Research

    DEFF Research Database (Denmark)

    Lueg, Klarissa


    The purpose of this paper is to introduce Multimodal Landscaping (ML) as a conceptual framework, and to illustrate how this approach can be applied within the field of higher education research. It is argued that ML is a suitable tool, especially, in studies investigating university...... internationalization, and in studies focusing on the agent level of higher education organizations. ML is argued to add to the diversity of methods within a social constructivist methodology. The author illustrates how ML is connected and/or different from kindred approaches. Pathways are proposed as to how...

  16. Academically Ambitious and Relevant Higher Education Research: The Legacy of the Consortium of Higher Education Researchers (United States)

    Teichler, Ulrich


    The Consortium of Higher Education Researchers (CHER) was founded in 1988 to stimulate international communication and collaboration of higher education researchers. A need was felt to offset the isolation of the small numbers of scholars in this area of expertise in many countries, as well as the isolation of individual disciplines addressing…

  17. Positioning Theory and Higher Education Research

    DEFF Research Database (Denmark)

    Christensen, Mette Krogh; Musaeus, Peter; Petersen, Eva Bendix

    The aim of this symposium is to connect scholars who use positioning theory in their research on very diverse issues in higher education and to open up the analytic to others who may be interested in taking it up. Positioning theory is a social constructionist approach and it emerged in the 1980s...... available. After this introduction, four paper presentations will follow (see abstracts below), and the session will conclude with a whole-group discussion of the potentials and pitfalls of the approach.......The aim of this symposium is to connect scholars who use positioning theory in their research on very diverse issues in higher education and to open up the analytic to others who may be interested in taking it up. Positioning theory is a social constructionist approach and it emerged in the 1980s...... in gender studies and social psychology. It is concerned with theorising and analysing how people position themselves and others, and the personal, relational, cultural, moral, political, and institutional effects hereof. Positioning theory is most commonly used in studies of the discursive constitution...

  18. TRIGA research reactors with higher power density

    International Nuclear Information System (INIS)

    Whittemore, W.L.


    The recent trend in new or upgraded research reactors is to higher power densities (hence higher neutron flux levels) but not necessarily to higher power levels. The TRIGA LEU fuel with burnable poison is available in small diameter fuel rods capable of high power per rod (≅48 kW/rod) with acceptable peak fuel temperatures. The performance of a 10-MW research reactor with a compact core of hexagonal TRIGA fuel clusters has been calculated in detail. With its light water coolant, beryllium and D 2 O reflector regions, this reactor can provide in-core experiments with thermal fluxes in excess of 3 x 10 14 n/cm 2 ·s and fast fluxes (>0.1 MeV) of 2 x 10 14 n/cm 2 ·s. The core centerline thermal neutron flux in the D 2 O reflector is about 2 x 10 14 n/cm 2 ·s and the average core power density is about 230 kW/liter. Using other TRIGA fuel developed for 25-MW test reactors but arranged in hexagonal arrays, power densities in excess of 300 kW/liter are readily available. A core with TRIGA fuel operating at 15-MW and generating such a power density is capable of producing thermal neutron fluxes in a D 2 O reflector of 3 x 10 14 n/cm 2 ·s. A beryllium-filled central region of the core can further enhance the core leakage and hence the neutron flux in the reflector. (author)

  19. Branding Canadian Higher Education. CBIE Research (United States)

    Kizilbash, Zainab


    The branding of national higher education systems is a global trend that has become increasingly common over the last decade. One of the main motives driving this trend is the view that branding a national higher education system will increase that country's market share of international students. This is evident as national higher education…

  20. Research Skills Development in Higher Education Students (United States)

    Bergamini, Tiziana Priede; Navarro, Cristina Lopez-Cozar


    This case study presents the development of a research project in a third-year undergraduate course, Family Business Administration. The research project aimed at promoting research skills in students. The authors formed working groups of no more than six students, and each group had to select an original research topic after conducting a…

  1. Studies of Aerodynamic Drag. (United States)


    31. Strouhal number vs Reynolds number - Effect of Wind tunnel Blockage. 150- P ecrit 100- 50k- o present d Qta o Mitry (1977) --Shair et ati (1963) 0...forces measured by the balance. 4.12 Final Tests A comprehensive set of drag measurements was taken with the new drag plates, the drag plates being

  2. Research skills development in higher education students

    Directory of Open Access Journals (Sweden)

    Tiziana Priede Bergamini


    Full Text Available This case study presents the development of a research project in a third-year undergraduate course, Family Business Administration. The research project aimed at promoting research skills in students. The authors formed working groups of no more than six students, and each group had to select an original research topic after conducting a literature review. Students were guided by the teachers and provided with initial reading materials, as well as an activity rubric specifying the minimum requirements of a scientific paper. The activity evaluation consisted of two parts, a written article (group assessment and an oral presentation (individual assessment. After the activity concluded, students were asked to answer an online satisfaction survey. Results showed students viewed the activity as positive and appreciated the chance to develop several competencies, including research skills. The authors conclude several objectives were achieved, including: familiarize students with scientific research; make sure students are cable of finding information through primary sources; have students apply the knowledge acquired during the course; promote responsibility in students; cultivate in students the capacity to summarize ideas and expose them in a reasoned way; have students learn from the experiences and knowledge of others; and develop in students the capacity to synthesize all that information. -------------------------- El desarrollo de la capacidad investigadora en estudiantes de educación superior Resumen  Este estudio de caso presenta el desarrollo de un proyecto de investigación en la asignatura “Administración de la Empresa Familiar” de tercer curso. El proyecto de investigación tenía como propósito fomentar de forma específica la capacidad investigadora de los alumnos. Se formaron grupos de trabajo de no más de seis estudiantes, y cada grupo tenía que seleccionar un tema de investigación original tras realizar una búsqueda de

  3. Correlated Coulomb drag in capacitively coupled quantum-dot structures

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka


    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs) -- a biasdriven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach which accounts for higher-order tunneling (cotunneling......) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechanism driven by nonlocal multi-electron cotunneling processes. Our theory establishes the conditions for a nonzero drag as well as the direction of the drag current in terms of microscopic system parameters...... on Coulomb drag in CQD systems....

  4. Researching teaching with ICT in higher education

    Directory of Open Access Journals (Sweden)

    Yngve Nordkvelle


    Full Text Available Yngve Nordkvelle, editorIn this issue we have collected four papers from Norwegian authors. The papers have been guest edited by associate professor Hugo Nordseth of North-Trøndelag University College. The authors represent the new generation of teachers in higher education who follow up on what new technologies have to offer for teaching and learning in higher education. Gard B. Jenset presents a study which investigates attitudes among student teachers toward using electronic resources in teaching. Two groups of student teachers, were asked to assess their skills and attitudes. Jenset introduced them to an example of how open-source, Web-based data and software could be used in teaching English culture and history. The students apporved of the experiment, but Jenset concludes that teacher education contributes little to improve their skills with technology. Cecilie Asting and Anne Swanberg discuss how to manage feedback and responses to students in large scale classes. Well planned teaching and learning activities can invite students to a variety of feedback activities. The experiements described gives insights into have such initiatives can be improved and succeed.Sven Åke Bjørke discuss the need to be aware of classifications of knowledge when curricula and learning activities are designed. The author argues for the entire sector to jump directly to "state of the art" of e-learning. To pursue this, he makes a quest for investment in teacher training in higher education, rather than focusing on technology. Hege Emma Rimmereide, Barbara Blair and Jon Hoem describe a project involving the use of wiki. Wiki Storyline is a web-based Storyline using wikis, and which demands an interdisciplinary approach to second language teaching. The Storyline creates motivation for written and oral communication. The authors have used Wiki Storyline in two in-service courses and the study presents a comparative analysis of  technical solutions as well as

  5. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  6. Comics as Research, Comics for Impact: The Case of Higher Fees, Higher Debts


    Ernesto Priego


    Researchers have turned to comics as outputs incorporating their research findings. These comics are print and/or online publications that can lead to the wider adoption of research and enhance educational practices, widen public engagement, and improve the possibilities for research to influence public policy.  This article presents an interview with Professor Katy Vigurs about 'Higher Fees, Higher Debts: Greater Expectations of Graduate Futures?', a comic based on a research report produced...

  7. Correlated Coulomb Drag in Capacitively Coupled Quantum-Dot Structures. (United States)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka


    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs)-a bias-driven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach that accounts for higher-order tunneling (cotunneling) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechanism driven by nonlocal multielectron cotunneling processes. Our theory establishes the conditions for a nonzero drag as well as the direction of the drag current in terms of microscopic system parameters. Interestingly, the direction of the drag current is not determined by the drive current, but by an interplay between the energy-dependent lead couplings. Studying the drag mechanism in a graphene-based CQD heterostructure, we show that the predictions of our theory are consistent with recent experiments on Coulomb drag in CQD systems.

  8. Vorticity confinement technique for drag prediction (United States)

    Povitsky, Alex; Snyder, Troy


    This work couples wake-integral drag prediction and vorticity confinement technique (VC) for the improved prediction of drag from CFD simulations. Induced drag computations of a thin wing are shown to be more accurate than the more widespread method of surface pressure integration when compared to theoretical lifting-line value. Furthermore, the VC method improves trailing vortex preservation and counteracts the shift from induced drag to numerical entropy drag with increasing distance of Trefftz plane downstream of the wing. Accurate induced drag prediction via the surface integration of pressure barring a sufficiently refined surface grid and increased computation time. Furthermore, the alternative wake-integral technique for drag prediction suffers from numerical dissipation. VC is shown to control the numerical dissipation with very modest computational overhead. The 2-D research code is used to test specific formulations of the VC body force terms and illustrate the computational efficiency of the method compared to a ``brute force'' reduction in spatial step size. For the 3-D wing simulation, ANSYS FLUENT is employed with the VC body force terms added to the solver with user-defined functions (UDFs). VC is successfully implemented to highly unsteady flows typical for Micro Air Vehicles (MAV) producing oscillative drag force either by natural vortex shedding at high angles of attack or by flapping wing motion.

  9. Just in Time Research: Data Breaches in Higher Education (United States)

    Grama, Joanna


    This "Just in Time" research is in response to recent discussions on the EDUCAUSE Higher Education Information Security Council (HEISC) discussion list about data breaches in higher education. Using data from the Privacy Rights Clearinghouse, this research analyzes data breaches attributed to higher education. The results from this…

  10. Research Productivity and Its Policy Implications in Higher Education Institutions (United States)

    Quimbo, Maria Ana T.; Sulabo, Evangeline C.


    Responding to the Commission on Higher Education's development plan of enhancing research culture among higher education institutions, this study was conducted to analyze the research productivity of selected higher education institutions. It covered five state universities in the Philippines where a total of 377 randomly selected faculty members…

  11. Racializing white drag. (United States)

    Rhyne, Ragan


    While drag is primarily understood as a performance of gender, other performative categories such as race, class, and sexuality create drag meaning as well. Though other categories of identification are increasingly understood as essential elements of drag by performers of color, whiteness remains an unmarked category in the scholarship on drag performances by white queens. In this paper, I argue that drag by white queens must be understood as a performance of race as well as gender and that codes of gender excess are specifically constructed through the framework of these other axes of identity. This essay asks whether white performance by white queens necessarily reinscribes white supremacy through the performance of an unmarked white femininity, or might drag performance complicate (though not necessarily subvert) categories of race as well as gender? In this essay, I will suggest that camp drag performances, through the deployment of class as a crucial category of performative femininity, might indeed be a key site through which whiteness is denaturalized and its power challenged. Specifically, I will read on camp as a politicized mode of race, class and gender performance, focusing on the intersections of these categories of identity in the drag performance of Divine.

  12. Pipeline Drag Reducers

    International Nuclear Information System (INIS)

    Marawan, H.


    Pipeline drag reducers have proven to be an extremely powerful tool in fluid transportation. High molecular weight polymers are used to reduce the frictional pressure loss ratio in crude oil pipelines, refined fuel and aqueous pipelines. Chemical structure of the main used pipeline drag reducers is one of the following polymers and copolymers classified according to the type of fluid to ; low density polyethylene, copolymer of I-hexane cross linked with divinyl benzene, polyacrylamide, polyalkylene oxide polymers and their copolymers, fluorocarbons, polyalkyl methacrylates and terpolymer of styrene, alkyl acrylate and acrylic acid. Drag reduction is the increase in pump ability of a fluid caused by the addition of small amounts of an additive to the fluid. The effectiveness of a drag reducer is normally expressed in terms of percent drag reduction. Frictional pressure loss in a pipeline system is a waste of energy and it costly. The drag reducing additive minimizes the flow turbulence, increases throughput and reduces the energy costs. The Flow can be increased by more than 80 % with existing assets. The effectiveness of the injected drag reducer in Mostorod to Tanta crude oil pipeline achieved 35.4 % drag reduction and 23.2 % flow increase of the actual performance The experimental application of DRA on Arab Petroleum Pipeline Company (Summed) achieved a flow increase ranging from 9-32 %

  13. Drag Coefficient Estimation in Orbit Determination (United States)

    McLaughlin, Craig A.; Manee, Steve; Lichtenberg, Travis


    Drag modeling is the greatest uncertainty in the dynamics of low Earth satellite orbits where ballistic coefficient and density errors dominate drag errors. This paper examines fitted drag coefficients found as part of a precision orbit determination process for Stella, Starlette, and the GEOSAT Follow-On satellites from 2000 to 2005. The drag coefficients for the spherical Stella and Starlette satellites are assumed to be highly correlated with density model error. The results using MSIS-86, NRLMSISE-00, and NRLMSISE-00 with dynamic calibration of the atmosphere (DCA) density corrections are compared. The DCA corrections were formulated for altitudes of 200-600 km and are found to be inappropriate when applied at 800 km. The yearly mean fitted drag coefficients are calculated for each satellite for each year studied. The yearly mean drag coefficients are higher for Starlette than Stella, where Starlette is at a higher altitude. The yearly mean fitted drag coefficients for all three satellites decrease as solar activity decreases after solar maximum.

  14. Managing the Research Imagination? Globalisation and Research in Higher Education (United States)

    Boden, Rebecca; Epstein, Debbie


    This paper argues that, during the late twentieth and early twenty-first centuries, universities have been captured by neo-liberal regimes of truth. We suggest that this may inhibit the "research imagination" within universities and, consequently, their role in the democratisation of knowledge. We consider the role of capital in the…

  15. Reflection: Research by Design: Design-Based Research and the Higher Degree Research Student (United States)

    Kennedy-Clark, Shannon


    The article "Research by design: Design-based research and the higher degree research student" (Kennedy-Clark, 2013) appeared in the "Journal of Learning Design" Volume 6, Issue 2 in 2013. Two years on, Shannon Kennedy-Clark reflects upon her original article. Upon being asked to revisit this article the author reflected upon…

  16. Comics as Research, Comics for Impact: The Case of Higher Fees, Higher Debts

    Directory of Open Access Journals (Sweden)

    Ernesto Priego


    Full Text Available Researchers have turned to comics as outputs incorporating their research findings. These comics are print and/or online publications that can lead to the wider adoption of research and enhance educational practices, widen public engagement, and improve the possibilities for research to influence public policy.  This article presents an interview with Professor Katy Vigurs about 'Higher Fees, Higher Debts: Greater Expectations of Graduate Futures?', a comic based on a research report produced for the Society for Research into Higher Education (2016.  In order to contextualize the interview, this article also provides an introduction to non-fiction comics research, and concludes with reflections on comics as a way of doing research. This article seeks to document and encourage further knowledge-exchange between the higher education sector and comics practitioners, and between researchers using comics in their research or as a means to disseminate their own research and those scholars who research comics as their main object of study.

  17. Drag Performance of Twist Morphing MAV Wing

    Directory of Open Access Journals (Sweden)

    Ismail N.I.


    Full Text Available Morphing wing is one of latest evolution found on MAV wing. However, due to few design problems such as limited MAV wing size and complicated morphing mechanism, the understanding of its aerodynamic behaviour was not fully explored. In fact, the basic drag distribution induced by a morphing MAV wing is still remained unknown. Thus, present work is carried out to compare the drag performance between a twist morphing wing with membrane and rigid MAV wing design. A quasi-static aeroelastic analysis by using the Ansys-Fluid Structure Interaction (FSI method is utilized in current works to predict the drag performance a twist morphing MAV wing design. Based on the drag pattern study, the results exhibits that the morphing wing has a partial similarities in overall drag pattern with the baseline (membrane and rigid wing. However, based CD analysis, it shows that TM wing induced higher CD magnitude (between 25% to 82% higher than to the baseline wing. In fact, TM wing also induced the largest CD increment (about 20% to 27% among the wings. The visualization on vortex structure revealed that TM wing also produce larger tip vortex structure (compared to baseline wings which presume to promote higher induce drag component and subsequently induce its higher CD performance.

  18. Academic Conferences: Representative and Resistant Sites for Higher Education Research (United States)

    Henderson, Emily F.


    The overarching argument made in this article is twofold. Firstly, academic conferences are posited as sites for higher education research. Secondly, the well-recognised emotional and social processes of conferences are used to make space at the boundaries of higher education research for psychosocial analysis. The article theorises conferences in…

  19. A new research role for higher professional education

    NARCIS (Netherlands)

    Floor Basten; Dr. Jan Geurts


    In 2001, higher professional education received a research function by law. This new research role is incorporated into so-called lectureships. In these lectureships, which are analogous to university chairs to some degree, experts in specific fields function as intermediaries between higher

  20. Methodological Orientation of Research Articles Appearing in Higher Education Journals (United States)

    Ritter, Sherri E.


    The purpose of this study was to understand the methodologies authors in higher education journals used to obtain knowledge in their fields. This study looked at five peer reviewed journals of higher education and analyzed the methods of research employed by the authors to help them answer their respective research questions. The methods of…

  1. Higher Education in Facts & Figures: Research and Innovation (United States)

    Universities UK, 2007


    This edition of Higher education in facts and figures focusses on Research and innovation. Research and innovation are crucial to the future of the UK's competitiveness. Universities are the prime drivers for this, both through producing, and acting as a magnet for, the best knowledge and talent. The UK's research performance is exceptionally…

  2. Higher Education Research Community in Taiwan: An Emerging Field (United States)

    Chan, Sheng-Ju; Chan, Ying


    This paper aims to explore the evolution and characteristics of the higher education research community in Taiwan. In echoing the development of the East Asian region, Taiwan has made substantial progress during the past two decades. The massification of higher education itself has played a major role in promoting the academic differentiation or…

  3. Higher Education Change and Social Networks: A Review of Research (United States)

    Kezar, Adrianna


    This article reviews literature on the potential for understanding higher education change processes through social network analysis (SNA). In this article, the main tenets of SNA are reviewed and, in conjunction with organizational theory, are applied to higher education change to develop a set of hypotheses that can be tested in future research.

  4. Risk management in higher education and research in the Netherlands

    NARCIS (Netherlands)

    Helsloot, I.; Jong, W


    This study examines risk in higher education and research on the basis of a classification into three domains. The practical utility of this division into three domains is that it makes it easier to see what risks are unique to higher education (custodianship of knowledge), what risks are dependent

  5. Community Music Knowledge Exchange Research in Scottish Higher Education (United States)

    Moran, Nikki; Loening, Gica


    This article examines the usefulness of Knowledge Exchange (KE) funding streams for higher education community music research projects, with a case study of one particular project that took place between February and April 2010. The project was funded via a KE stream, linking University researchers with a well-established community music charity…

  6. The Future Relations Between Research and Higher Education. (United States)

    Nybom, Thorsten


    Explores factors affecting the relationship between research and higher education, particularly in the rapidly changing European context where the rise in mass education and institutional differentiation has created a crisis for the traditional university. Argues that these changes will lead to a fundamental restructuring of research and its…

  7. An analysis of processes that can shape higher education research ...

    African Journals Online (AJOL)

    This article is not only about African postgraduates at University of Natal: it is also an attempt to delineate what shapes research into Higher Education done under differing conditions and for different purposes (part 1). As material to illustrate this research metamorphosis, the material from an investigation into postgraduates ...

  8. Bourdieu and Higher Education Research: A Bricolage Approach (United States)

    Morrison, Andrew


    I argue for the continuing relevance of the Bourdieusian theoretical schema to research related to higher education. The paper discusses my use of Bourdieu in two research projects: an examination of the educational and occupational decision-making of final-year vocational A-level students; an analysis of the perceptions of final-year…

  9. Aerodynamic Drag Scoping Work.

    Energy Technology Data Exchange (ETDEWEB)

    Voskuilen, Tyler [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Erickson, Lindsay Crowl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knaus, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This memo summarizes the aerodynamic drag scoping work done for Goodyear in early FY18. The work is to evaluate the feasibility of using Sierra/Low-Mach (Fuego) for drag predictions of rolling tires, particularly focused on the effects of tire features such as lettering, sidewall geometry, rim geometry, and interaction with the vehicle body. The work is broken into two parts. Part 1 consisted of investigation of a canonical validation problem (turbulent flow over a cylinder) using existing tools with different meshes and turbulence models. Part 2 involved calculating drag differences over plate geometries with simple features (ridges and grooves) defined by Goodyear of approximately the size of interest for a tire. The results of part 1 show the level of noise to be expected in a drag calculation and highlight the sensitivity of absolute predictions to model parameters such as mesh size and turbulence model. There is 20-30% noise in the experimental measurements on the canonical cylinder problem, and a similar level of variation between different meshes and turbulence models. Part 2 shows that there is a notable difference in the predicted drag on the sample plate geometries, however, the computational cost of extending the LES model to a full tire would be significant. This cost could be reduced by implementation of more sophisticated wall and turbulence models (e.g. detached eddy simulations - DES) and by focusing the mesh refinement on feature subsets with the goal of comparing configurations rather than absolute predictivity for the whole tire.

  10. Evaluation of Skin Friction Drag for Liner Applications in Aircraft (United States)

    Gerhold, Carl H.; Brown, Martha C.; Jasinski, Christopher M.


    A parameter that is gaining significance in the evaluation of acoustic liner performance is the skin friction drag induced by air flow over the liner surface. Estimates vary widely regarding the amount of drag the liner induces relative to a smooth wall, from less than a 20% increase to nearly 100%, and parameters such as face sheet perforate hole diameter, percent open area, and sheet thickness are expected to figure prominently in the skin friction drag. Even a small increase in liner drag can impose an economic penalty, and current research is focused on developing 'low drag' liner concepts, with the goal being to approach the skin friction drag of a smooth wall. The issue of skin friction drag takes on greater significance as airframe designers investigate the feasibility of putting sound absorbing liners on the non-lifting surfaces of the wings and fuselage, for the purpose of reducing engine noise reflected and scattered toward observers on the ground. Researchers at the NASA Langley Research Center have embarked on investigations of liner skin friction drag with the aims of: developing a systematic drag measurement capability, establishing the drag of current liners, and developing liners that produce reduced drag without compromising acoustic performance. This paper discusses the experimental procedures that have been developed to calculate the drag coefficient based on the change in momentum thickness and the companion research program being carried out to measure the drag directly using a force balance. Liner samples that are evaluated include a solid wall with known roughness and conventional liners with perforated facesheets of varying hole diameter and percent open area.

  11. Magnon-drag thermopile. (United States)

    Costache, Marius V; Bridoux, German; Neumann, Ingmar; Valenzuela, Sergio O


    Thermoelectric effects in spintronics are gathering increasing attention as a means of managing heat in nanoscale structures and of controlling spin information by using heat flow. Thermal magnons (spin-wave quanta) are expected to play a major role; however, little is known about the underlying physical mechanisms involved. The reason is the lack of information about magnon interactions and of reliable methods to obtain it, in particular for electrical conductors because of the intricate influence of electrons. Here, we demonstrate a conceptually new device that enables us to gather information on magnon-electron scattering and magnon-drag effects. The device resembles a thermopile formed by a large number of pairs of ferromagnetic wires placed between a hot and a cold source and connected thermally in parallel and electrically in series. By controlling the relative orientation of the magnetization in pairs of wires, the magnon drag can be studied independently of the electron and phonon-drag thermoelectric effects. Measurements as a function of temperature reveal the effect on magnon drag following a variation of magnon and phonon populations. This information is crucial to understand the physics of electron-magnon interactions, magnon dynamics and thermal spin transport.

  12. Research Issues in Evaluating Learning Pattern Development in Higher Education (United States)

    Richardson, John T. E.


    This article concludes the special issue of "Studies in Educational Evaluation" concerned with "Evaluating learning pattern development in higher education" by discussing research issues that have emerged from the previous contributions. The article considers in turn: stability versus variability in learning patterns; old versus new analytic…

  13. Higher Education Research in Uganda: Problems and Prospects (United States)

    Owoeye, J. S.; Oyebade, S. A.


    Research is regarded as essential for development and the application of new knowledge for the benefit of society. Higher education in Uganda has expanded rapidly in the last 20 years. Universities have become the most important institutions in the achievement of national and international goals in enhancing the quality of life, wealth creation,…

  14. COBRE Research Workshop on Higher Education: Equity and Efficiency. (United States)

    Chicago Univ., IL.

    This document comprises 8 papers presented at the COBRE Research Workshop on Higher Education. The papers are: (1) "Schooling and Equality from Generation to Generation;" (2) "Time Series Changes in Personal Income Inequality: The United States Experience, 1939 to 1985;" (3) "Education, Income, and Ability;" (4) "Proposals for Financing Higher…

  15. International Consultation on Peace Education and Research in Higher Education. (United States)

    Higher Education in Europe, 1986


    A January 1986 UNESCO international conference on the role of higher education in promoting international understanding, cooperation, peace, and respect for human rights focused on the nuclear threat and conventional warfare, the role of international governmental and nongovernmental organizations, research and education for peace, and…

  16. Higher Education Technology and Research: Creating Excellence through State Investments (United States)

    New Jersey Commission on Higher Education, 2004


    Colleges and universities in New Jersey play a critical role in building and sustaining economic prosperity and quality of life in the state and beyond. Through advancements in technology and research, higher education helps to create new jobs, improve the workforce, develop new knowledge, and boost the overall economy. This report summarizes…

  17. Research and Support Strategies For Women's Higher Education. (United States)

    Babbitt, Samuel F.; And Others

    Inadequate support is presently offered for the study of certain important questions which have serious implications for educational policies affecting women. Priority should be given to the support of those areas of research and program development and evaluation that have the most critical implications for both the higher education of women and…

  18. Furthering Alternative Cultures of Valuation in Higher Education Research (United States)

    Downs, Yvonne


    The value of higher education is often implicit or assumed in educational research. The underlying and antecedent premises that shape and influence debates about value remain unchallenged, which perpetuates the dominant, but limiting, terms of the debate and fosters reductionism. The article proceeds on the premise that analyses of value are not…

  19. Considerations for higher efficiency and productivity in research activities. (United States)

    Forero, Diego A; Moore, Jason H


    There are several factors that are known to affect research productivity; some of them imply the need for large financial investments and others are related to work styles. There are some articles that provide suggestions for early career scientists (PhD students and postdocs) but few publications are oriented to professors about scientific leadership. As academic mentoring might be useful at all levels of experience, in this note we suggest several key considerations for higher efficiency and productivity in academic and research activities. More research is needed into the main work style features that differentiate highly productive scientists and research groups, as some of them could be innate and others could be transferable. As funding agencies, universities and research centers invest large amounts of money in order to have a better scientific productivity, a deeper understanding of these factors will be of high academic and societal impact.

  20. The effect of sodium hydroxide on drag reduction using banana peel as a drag reduction agent (United States)

    Kaur, H.; Jaafar, A.


    Drag reduction is observed as reduced frictional pressure losses under turbulent flow conditions. Drag reduction agent such as polymers can be introduced to increase the flowrate of water flowing and reduce the water accumulation in the system. Currently used polymers are synthetic polymers, which will harm our environment in excessive use of accumulation. A more environmentally-friendly drag reduction agent such as the polymer derived from natural sources or biopolymer, is then required for such purpose. As opposed to the synthetic polymers, the potential of biopolymers as drag reduction agents, especially those derived from a local plant source are not extensively explored. The drag reduction of a polymer produced from a local plant source within the turbulent regime was explored and assessed in this study using a rheometer, where a reduced a torque produced was perceived as a reduction of drag. This method proposed is less time consuming and is more practical which is producing carboxymethylcellulose from the banana peel. The cellulose powder was converted to carboxymethylcellulose (CMC) by etherification process. The carboxymethylation reaction during the synthesizing process was then optimized against the reaction temperature, reaction time and solubility. The biopolymers were then rheologically characterized, where the viscoelastic effects and the normal stresses produced by these biopolymers were utilized to further relate and explain the drag reduction phenomena. The research was structured to focus on producing the biopolymer and to assess the drag reduction ability of the biopolymer produced. The rheological behavior of the biopolymers was then analyzed based on the ability of reducing drag. The results are intended to expand the currently extremely limited experimental database. Based on the results, the biopolymer works as a good DRA.

  1. Drag force, drag torque, and Magnus force coefficients of rotating spherical particle moving in fluid

    Czech Academy of Sciences Publication Activity Database

    Lukerchenko, Nikolay; Kvurt, Y.; Keita, Ibrahima; Chára, Zdeněk; Vlasák, Pavel


    Roč. 30, č. 1 (2012), s. 55-67 ISSN 0272-6351 R&D Projects: GA AV ČR IAA200600603; GA ČR GA103/09/1718 Institutional research plan: CEZ:AV0Z20600510 Keywords : drag force * drag torque * Magnus force * Reynolds number * rotational Reynolds number Subject RIV: BK - Fluid Dynamics Impact factor: 0.435, year: 2012

  2. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya


    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.

  3. Dragging of inertial frames. (United States)

    Ciufolini, Ignazio


    The origin of inertia has intrigued scientists and philosophers for centuries. Inertial frames of reference permeate our daily life. The inertial and centrifugal forces, such as the pull and push that we feel when our vehicle accelerates, brakes and turns, arise because of changes in velocity relative to uniformly moving inertial frames. A classical interpretation ascribed these forces to acceleration relative to some absolute frame independent of the cosmological matter, whereas an opposite view related them to acceleration relative to all the masses and 'fixed stars' in the Universe. An echo and partial realization of the latter idea can be found in Einstein's general theory of relativity, which predicts that a spinning mass will 'drag' inertial frames along with it. Here I review the recent measurements of frame dragging using satellites orbiting Earth.

  4. Incorporating current research into formal higher education settings using Astrobites (United States)

    Sanders, Nathan E.; Kohler, Susanna; Faesi, Chris; Villar, Ashley; Zevin, Michael


    A primary goal of many undergraduate- and graduate-level courses in the physical sciences is to prepare students to engage in scientific research or to prepare students for careers that leverage skillsets similar to those used by research scientists. Even for students who may not intend to pursue a career with these characteristics, exposure to the context of applications in modern research can be a valuable tool for teaching and learning. However, a persistent barrier to student participation in research is familiarity with the technical language, format, and context that academic researchers use to communicate research methods and findings with each other: the literature of the field. Astrobites, an online web resource authored by graduate students, has published brief and accessible summaries of more than 1300 articles from the astrophysical literature since its founding in 2010. This article presents three methods for introducing students at all levels within the formal higher education setting to approaches and results from modern research. For each method, we provide a sample lesson plan that integrates content and principles from Astrobites, including step-by-step instructions for instructors, suggestions for adapting the lesson to different class levels across the undergraduate and graduate spectrum, sample student handouts, and a grading rubric.

  5. On the origin of the drag force on golf balls (United States)

    Balaras, Elias; Beratlis, Nikolaos; Squires, Kyle


    It is well establised that dimples accelerate the drag-crisis on a sphere. The result of the early drag-crisis is a reduction of the drag coefficient by more than a factor of two when compared to a smooth sphere at the same Reynolds number. However, when the drag coefficients for smooth and dimpled spheres in the supercritical regime are compared, the latter is higher by a factor of two to three. To understand the origin of this behavior we conducted direct numerical simulations of the flow around a dimpled sphere, which is similar to commercially available golf balls, in the supercritical regime. By comparing the results to those for a smooth sphere it is found that dimples, although effective in accelerating the drag crisis, impose a local drag-penalty, which contributes significantly to the overall drag force. This finding challenges the broadly accepted view, that the dimples only indirectly affect the drag force on a golf ball by manipulating the structure of the turbulent boundary layer near the wall and consequently affect global separation. Within this view, typically the penalty on the drag force imposed by the dimples is assumed to be small and coming primarily from skin friction. The direct numerical simulations we will report reveal a very different picture.

  6. Offsetting deficit conceptualisations: methodological considerations for higher education research

    Directory of Open Access Journals (Sweden)

    Lynn Coleman


    Full Text Available This paper contributes to the current introspection in the academic development community that critiques the persistent conceptualisations of students as deficient. Deficit discourses are also implicated in many of the student support, curriculum and pedagogic initiatives employed across the higher education sector. The argument developed here, unlike most of the existing debates which focus on pedagogic or institutional initiatives, explores how the research interests and methodological choices of academic developers and researchers could incorporate sensitivity against deficit conceptions and foster more contextualised accounts of students and their learning. This article uses an ethnographic study into the assignment practices of vocational higher education students to show how certain methodological and theoretical choices engender anti-deficit conceptualisations. The study’s analytic framework uses the concepts of literacy practices and knowledge recontextualisation to place analytic attention on both the students’ assignment practices and the influence of curriculum decision making on such practices. The significance of this dual focus is its ability to capture the complexity of students’ meaning-making during assignment production, without remaining silent about the structuring influence of the curriculum. I argue in this paper that the focus on both students and curriculum is able to offer contextualised accounts of students’ interpretations and enacted experiences of their assessment and curriculum environment. Exploring the multidimensional nature of student learning experiences in ways that accommodate the influence of various contextual realities brings researchers and their research agendas closer to offsetting deficit conceptualisation.

  7. The drag and lift of different non-spherical particles from low to high Re (United States)

    Sanjeevi, Sathish K. P.; Padding, Johan


    The present work investigates a simplified drag and lift model that can be used for different non-spherical particles. The flow around different non-spherical particles is studied using a multi-relaxation-time lattice Boltzmann method. We compute the mean drag coefficient CD , ϕ at different incident angles ϕ for a wide range of Reynolds numbers (Re). We show that the sine-squared drag law CD , ϕ =CD , ϕ =0° +(CD , ϕ =90° -CD , ϕ =0°) sin2 ϕ holds up to large Reynolds numbers Re = 2000 . The sine-squared dependence of CD occurs at Stokes flow (very low Re) due to linearity of the flow fields. We explore the physical origin behind the sine-squared law at high Re , and reveal that surprisingly, this does not occur due to linearity of flow fields. Instead, it occurs due to an interesting pattern of pressure distribution contributing to the drag, at higher Re , for different incident angles. Similarly, we find that the equivalent theoretical equation of lift coefficient CL can provide a decent approximation, even at high Re , for elongated particles. Such a drag and lift law valid at high Re is very much useful for Euler-Lagrangian fluidization simulations of the non-spherical particles. European Research Council (ERC) consolidator Grant scheme, Contract No. 615096 (NonSphereFlow).

  8. Experimental evaluation of the drag force and drag torque acting on a rotating spherical particle moving in fluid

    Czech Academy of Sciences Publication Activity Database

    Lukerchenko, Nikolay; Kvurt, Y.; Kharlamov, Alexander; Chára, Zdeněk; Vlasák, Pavel


    Roč. 56, č. 2 (2008), s. 88-94 ISSN 0042-790X R&D Projects: GA AV ČR IAA200600603 Institutional research plan: CEZ:AV0Z20600510 Keywords : drag force * drag torque * spherical particle * rotational movement * translational movement Subject RIV: DA - Hydrology ; Limnology

  9. Researcher Creations? The Positioning of Policy Texts in Higher Education Research (United States)

    Ashwin, Paul; Smith, Karen


    In this article we explore the way in which policy texts are positioned in a selection of higher education journal articles. Previous research has suggested that policy implementation studies have taken an uncritical approach to researching policies. Based on an analysis of articles published in higher education and policy journals in 2011, we…

  10. Drag reduction through self-texturing compliant bionic materials (United States)

    Liu, Eryong; Li, Longyang; Wang, Gang; Zeng, Zhixiang; Zhao, Wenjie; Xue, Qunji


    Compliant fish skin is effectively in reducing drag, thus the design and application of compliant bionic materials may be a good choice for drag reduction. Here we consider the drag reduction of compliant bionic materials. First, ZnO and PDMS mesh modified with n-octadecane were prepared, the drag reduction of self-texturing compliant n-octadecane were studied. The results show that the mesh modified by ZnO and PDMS possess excellent lipophilic and hydrophobic, thus n-octadecane at solid, semisolid and liquid state all have good adhesion with modified mesh. The states of n-octadecane changed with temperature, thus, the surface contact angle and adhesive force all varies obviously at different state. The contact angle decreases with temperature, the adhesive force shows a lower value at semisolid state. Furthermore, the drag testing results show that the compliant n-octadecane film is more effectively in drag reduction than superhydrophobic ZnO/PDMS film, indicating that the drag reduction mechanism of n-octadecane is significantly different with superhydrophobic film. Further research shows that the water flow leads to self-texturing of semisolid state n-octadecane, which is similar with compliant fish skin. Therefore, the compliant bionic materials of semisolid state n-octadecane with regular bulge plays a major role in the drag reduction.

  11. Analysis of Drag Reduction Methods and Mechanisms of Turbulent

    Directory of Open Access Journals (Sweden)

    Gu Yunqing


    Full Text Available Turbulent flow is a difficult issue in fluid dynamics, the rules of which have not been totally revealed up to now. Fluid in turbulent state will result in a greater frictional force, which must consume great energy. Therefore, it is not only an important influence in saving energy and improving energy utilization rate but also an extensive application prospect in many fields, such as ship domain and aerospace. Firstly, bionic drag reduction technology is reviewed and is a hot research issue now, the drag reduction mechanism of body surface structure is analyzed, such as sharks, earthworms, and dolphins. Besides, we make a thorough study of drag reduction characteristics and mechanisms of microgrooved surface and compliant wall. Then, the relevant drag reduction technologies and mechanisms are discussed, focusing on the microbubbles, the vibrant flexible wall, the coating, the polymer drag reduction additives, superhydrophobic surface, jet surface, traveling wave surface drag reduction, and the composite drag reduction methods. Finally, applications and advancements of the drag reduction technology in turbulence are prospected.

  12. Exploring the Relevance of Qualitative Research Synthesis to Higher Education Research and Practice (United States)

    Major, Claire; Savin-Baden, Maggi


    This paper proposes the importance of qualitative research synthesis to the field of higher education. It examines seven key texts that undertake synthesis in this field and compares essential features and elements across studies. The authors indicate strengths of the approaches and highlight ways forward for using qualitative research synthesis…

  13. Research by Design: Design-Based Research and the Higher Degree Research student (United States)

    Kennedy-Clark, Shannon


    Design-based research lends itself to educational research as the aim of this approach is to develop and refine the design of artefacts, tools and curriculum and to advance existing theory or develop new theories that can support and lead to a deepened understanding of learning. This paper provides an overview of the potential benefits of using a…

  14. Aerodynamic drag on intermodal railcars (United States)

    Kinghorn, Philip; Maynes, Daniel


    The aerodynamic drag associated with transport of commodities by rail is becoming increasingly important as the cost of diesel fuel increases. This study aims to increase the efficiency of intermodal cargo trains by reducing the aerodynamic drag on the load carrying cars. For intermodal railcars a significant amount of aerodynamic drag is a result of the large distance between loads that often occurs and the resulting pressure drag resulting from the separated flow. In the present study aerodynamic drag data have been obtained through wind tunnel testing on 1/29 scale models to understand the savings that may be realized by judicious modification to the size of the intermodal containers. The experiments were performed in the BYU low speed wind tunnel and the test track utilizes two leading locomotives followed by a set of five articulated well cars with double stacked containers. The drag on a representative mid-train car is measured using an isolated load cell balance and the wind tunnel speed is varied from 20 to 100 mph. We characterize the effect that the gap distance between the containers and the container size has on the aerodynamic drag of this representative rail car and investigate methods to reduce the gap distance.

  15. Quality Research in Higher Education Institutions in Oman: Some Views of Teacher Researchers

    Directory of Open Access Journals (Sweden)

    Ahmed Ali Saleh Al Ajmi


    Full Text Available Academic research remains a prime source of knowledge and innovation for higher education institutions (HEIs that strive to grow, expand and develop their academic reputations and standards. Yet, research informs teaching practices, shapes social changes and it has financial outcomes for HEIs. Therefore, it is imperative to develop institutional policies and strategies for promoting and sustaining quality research in HEIs in Oman. There are a number of international frameworks and models which have been developed to measure research quality in HEIs around the world. For example, bibliometrics were used to assess research quality in HEIs in the UK because bibliometric data can provide a number of component variables. An appropriate bibliometric model may include components such as output volume, diversity of outputs, citation volume, journal impact factor and average citations per publication, etc. Moreover, other popular examples of models for assessing research quality are Multidimensional Research Assessment Matrix (MRAM used in Europe and the UK’s Research Assessment Exercise (RAE. However, neither of the above mentioned models is adopted by HEIs in Oman. Thus, the current study is an attempt to explore some institutional, international, logistic and pragmatic factors that impact academic research and publication quality, review popular international research quality assessment models and explore the possibility of applying them in the Omani context. To achieve the study objectives, 20 teacher researchers were surveyed and the findings and recommendations were presented. Keywords: Quality Research, HEIs in Oman, International Models, Factors, Teacher Researchers' Views

  16. Academic research at a South African higher education institution ...

    African Journals Online (AJOL)

    Log in or Register to get access to full text downloads. ... The investigation involved an ethnographic case study of the research culture at one college at the institution. ... programmes and travel opportunities to interact with other researchers.

  17. Logistics case study based research: Towards higher quality

    DEFF Research Database (Denmark)

    Pedrosa, Alex; Näslund, Dag; Jasmand, Claudia


    analysis of 134 case study based articles published in six leading logistics and supply chain management (SCM) journals between 1998 and 2010 is used to assess and evaluate the quality of the case study based research approach as documented in these publications. Findings – This research provides...... to address to ensure high quality of the case study based research approach in published articles. Research limitations/implications – This study is limited to the analysis of published articles in six logistics and SCM journals. Further research should investigate different journals in logistics and other...

  18. Design Research and the Solo Higher Degree Research Student: Strategies to Embed Trustworthiness and Validity into the Research Design (United States)

    Kennedy-Clark, Shannon


    This paper puts forward a set of criteria for ensuring trustworthiness in design research studies undertaken by Higher Degree Research (HDR) students. Design research is aimed at exploring educational problems and refining theory and practice by defining a pedagogical outcome and is a methodological approach often associated with the Learning…

  19. Resolvent-based feedback control for turbulent friction drag reduction (United States)

    Kawagoe, Aika; Nakashima, Satoshi; Luhar, Mitul; Fukagata, Koji


    Suboptimal control for turbulent friction drag reduction has been studied extensively. Nakashima et al. (accepted) extended resolvent analysis to suboptimal control, and for the control where the streamwise wall shear stress is used as an input (Case ST), they revealed the control effect across spectral space is mixed: there are regions of drag increase as well as reduction. This suggests that control performance may be improved if the control is applied for selective wavelengths, or if a new law is designed to suppress the spectral region leading to drag increase. In the present study, we first assess the effect of suboptimal control for selective wavelengths via DNS. The friction Reynolds number is set at 180. For Case ST, resolvent analysis predicts drag reduction at long streamwise wavelengths. DNS with control applied only for this spectral region, however, did not result in drag reduction. Then, we seek an effective control law using resolvent analysis and propose a new law. DNS results for this law are consistent with predictions from resolvent analysis, and about 10% drag reduction is attained. Further, we discuss how this law reduces the drag from a dynamical and theoretical point of view. This work was supported through Grant-in-Aid for Scientic Research (C) (No. 25420129) by Japan Society for the Promotion of Science (JSPS).

  20. Marketing in Higher Education. AAHE-ERIC/Higher Education Research Report No. 5, 1981. (United States)

    Grabowski, Stanley M.

    Approaches to developing a successful marketing program for universities that is fair to both students and the academic integrity of the institution are considered. A comprehensive marketing plan includes market research, positioning, strategy formulation; recruitment/admission, communications, curriculum evaluation, retention, and evaluation.…

  1. Action research as a qualitative research approach for understanding technology professional development in higher education

    NARCIS (Netherlands)

    drs Maurice Schols


    Over the last two decades, institutions for higher education such as universities and colleges have rapidly expanded and as a result have experienced profound changes in processes of research and organization. However, the rapid expansion and change has fuelled concerns about issues such as

  2. Using Design-Based Research in Higher Education Innovation (United States)

    Ford, Cristi; McNally, Darragh; Ford, Kate


    This paper discusses the design-based research approach used by the Center for Innovation in Learning and Student Success (CILSS) at the University of Maryland, University College (UMUC). CILSS is a laboratory for conducting applied research that focuses on continuous improvements to the university's instruction of curriculum, learning models, and…

  3. Action research as a means of course development in higher ...

    African Journals Online (AJOL)

    Action Research has been used in many fields of endeavour as a useful means of improving practice. This article describes how this methodology was used to develop a programme of language learning at the University of the Free State. The researcher was tasked with the development and implementation of an English ...

  4. Neoliberal Competition in Higher Education Today: Research, Accountability and Impact (United States)

    Olssen, Mark


    Drawing on Foucault's elaboration of neoliberalism as a positive form of state power, the ascendancy of neoliberalism in higher education in Britain is examined in terms of the displacement of public good models of governance, and their replacement with individualised incentives and performance targets, heralding new and more stringent conceptions…

  5. Higher Education Research 2000-2010: Changing Journal Publication Patterns (United States)

    Tight, Malcolm


    The articles published in 15 specialist academic journals--based in Australasia, Europe and North America--focusing on higher education in the years 2010 (n = 567) and 2000 (n = 388) are analysed. The analysis focuses on: the themes and issues addressed in the articles published, the methods and methodologies used, theoretical engagement, the…

  6. Formulation of Higher Education Institutional Strategy Using Operational Research Approaches (United States)

    Labib, Ashraf; Read, Martin; Gladstone-Millar, Charlotte; Tonge, Richard; Smith, David


    In this paper a framework is proposed for the formulation of a higher education institutional (HEI) strategy. This work provides a practical example, through a case study, to demonstrate how the proposed framework can be applied to the issue of formulation of HEI strategy. The proposed hybrid model is based on two operational research…

  7. Researching Absences and Silences in Higher Education: Data for Democratisation (United States)

    Morley, Louise


    Knowledge, power and democracy are being more explicitly related to higher education globally. Increasingly there are calls for cognitive justice and the development of a sociology of absences, particularly in relation to structures of inequalities and knowledge production from the Global South. The university of the future will need to be…

  8. Investigation of Drag Coefficient for Rigid Ballute-like Shapes (United States)

    Carnasciali, Maria-Isabel; Mastromarino, Anthony


    One common method of decelerating an object during atmospheric entry, descent, and landing is the use of parachutes. Another deceleration technology is the ballute - a combination of balloon and parachute. A CFD study was conducted using commercially available software to investigate the flow-field and the coefficient of drag for various rigid ballute-like shapes at varying Reynolds numbers. The impact of size and placement of the burble-fence as well as number, size, and shape of inlets was considered. Recent experimental measurements conducted during NASA's Low-Density Supersonic Decelerator program revealed a much higher coefficient of drag (Cd) for ballutes than previously encountered. Using atmospheric drag to slow down and land reduces the need for heavy fuel and rocket engines and thus, high values of drag are desired. Funding for this work, in part, provided by the CT Space Grant Consortium.



    Gordan Camelia; Pop Marius Dorel


    The purpose of this paper is to discuss the main issues that deal with higher education institutionsâ€(tm) mission statements, from a marketing perspective. It has long been argued in the literature that missions represent the foundation upon which institutions build their strategic plans, and that they should be the first step any institution takes before designing its strategy. Based on a review of the most recent literature in the field, the paper explains why missions appear as a relevant...

  10. Spatial support of knowledge production in higher education : Research paper

    NARCIS (Netherlands)

    van Sprang, H; Groen, BH; van der Voordt, Theo


    This paper explores the impact of the physical and social dimensions of the work environment on satisfaction and perceived productivity of knowledge workers in Dutch universities of applied sciences. The approach took the form of a literature review, multiple case study of six research centres using

  11. Virtuous Mess and Wicked Clarity: Struggle in Higher Education Research (United States)

    McArthur, Jan


    This article considers the value of clarity--of theory, method and purposes--in educational research. It draws upon the work of early critical theorist, Theodor Adorno, and particularly his notion of negative dialectics and his challenge to the traditional dichotomy of theory and practice. Using the notions of virtuous mess and wicked clarity, I…

  12. The SANE Research Project: Its Implications for Higher Education. (United States)

    Harrison, Andrew; Dugdale, Shirley


    Describes a 2-year research program called Sustainable Accommodation for the New Economy (SANE), which is exploring the implications of the distributed workplace. Its focus is on the creation of sustainable, collaborative workplaces for knowledge workers across Europe, encompassing both virtual and physical spaces. Discusses its implications for…

  13. Research-related intercultural higher education in satellite geodesy (United States)

    Mayer, M.; Heck, B.; Krueger, C. P.


    In order to improve the education of young researchers (master degree, PhD, PostDocs) a cooperation between the Department of Geomatics (DGEOM), Federal University of Paraná (UFPR), Curitiba (Brazil) and the Geodetic Institute (GIK), University Karlsruhe (TH), Karlsruhe (Germany) was established which now exists since more than five years. The joint venture is actually called "PROBRAL: Precise positioning and height determination by means of GPS: Modeling of errors and transformation into physical heights" and focuses on research and education within the field of satellite geodesy. PROBRAL is funded by the Brazilian academic exchange service CAPES and the German academic exchange service DAAD. The geodetic aim of the research project is to validate and improve the quality of 3d positions derived from observations related to satellite navigation systems like GPS. In order to fulfill this ambitious goal sustainably, research has to be carried out in close cooperation. At the same time, e.g. to guarantee continuous success, a coordinated education has to be ensured. Besides technical education aspects key competences (e.g. language, capacity for teamwork, project management skills) are trained. Within the presentation the lessons which were learned from this project are discussed in detail.

  14. Evaluating the "Evaluative State": Implications for Research in Higher Education. (United States)

    Dill, David D.


    Examines the "evaluative state" that is, public management-based evaluation systems--in the context of experiences in the United Kingdom and New Zealand, and suggests that further research is needed to examine problems in the evaluative state itself, in how market competition impacts upon it, and how academic oligarchies influence the…

  15. Research Productivity and Social Capital in Australian Higher Education (United States)

    Salaran, Mohammad


    This study investigates the role of social capital in raising research productivity in academic institutions. Social capital as a strategic resource embedded in social relationships can be utilised towards decreasing pressures from external environmental conditions, such as the global financial crisis. A survey was sent to academic staff in five…

  16. Information Security Issues in Higher Education and Institutional Research (United States)

    Custer, William L.


    Information security threats to educational institutions and their data assets have worsened significantly over the past few years. The rich data stores of institutional research are especially vulnerable, and threats from security breaches represent no small risk. New genres of threat require new kinds of controls if the institution is to prevent…

  17. Handbook of Research on Innovative Technology Integration in Higher Education (United States)

    Nafukho, Fredrick Muyia, Ed.; Irby, Beverly J., Ed.


    Our increasingly globalized world is driven by shared knowledge, and nowhere is that knowledge more important than in education. Now more than ever, there is a demand for technology that will assist in the spread of knowledge through customized, self-paced, and on-demand learning. The Handbook of Research on Innovative Technology Integration in…

  18. Drag reduction by a polymeric aluminium soap

    Energy Technology Data Exchange (ETDEWEB)

    Rodriquez, F.


    The pressure drop per unit length of pipe during the turbulent flow of liquids is reduced by certain additives. Most such drag reducing or friction-reducing agents are polymers of very high molecular weight. Some time ago, aluminum soaps were described as reducing drag in organic solvents, but the viscosity in laminar flow of such solutions was much higher than that of the solvents. More recently, it was found that aluminum dioleate and aluminum palmitate did not reduce turbulent friction until the solute concentration reached 0.75%. The viscosity at this concentration was 2 or 3 times that of the solvent, benzene. Exploratory work with aluminum di-2-ethylhexanoate indicates that it is an effective drag-reducing agent at concentrations which increase the viscosity of toluene by less than 10%. The dependence of the effectiveness on concentration is similar to that of most polymers. Taking into account the normal change in friction factor with Reynolds number together with end effects in the apparatus, the maximum effectiveness (x = 54 cm) corresponds to a a decrease in friction factor to less than a quarter of the original value for toluene alone. (13 refs.)

  19. Spatial support of knowledge production in higher education: Research paper


    van Sprang, H; Groen, BH; van der Voordt, Theo


    This paper explores the impact of the physical and social dimensions of the work environment on satisfaction and perceived productivity of knowledge workers in Dutch universities of applied sciences. The approach took the form of a literature review, multiple case study of six research centres using interviews and logbook analysis, and web-based survey (N = 188). Optimally facilitating knowledge production requires both space for concentration (to support internalisation of knowledge) and spa...

  20. Gravitational waves and dragging effects (United States)

    Bičák, Jiří; Katz, Joseph; Lynden-Bell, Donald


    Linear and rotational dragging effects of gravitational waves on local inertial frames are studied in purely vacuum spacetimes. First, the linear dragging caused by a simple cylindrical pulse is investigated. Surprisingly strong transverse effects of the pulse are exhibited. The angular momentum in cylindrically symmetric spacetimes is then defined and confronted with some results in the literature. In the main part, a general procedure is developed for studying weak gravitational waves with translational but not axial symmetry which can carry angular momentum. After a suitable averaging the rotation of local inertial frames due to such rotating waves can be calculated explicitly and illustrated graphically. This is done in detail in the accompanying paper. Finally, the rotational dragging is given for strong cylindrical waves interacting with a rotating cosmic string with a small angular momentum.

  1. Connecting Higher Education Research in Japan with the International Academic Community (United States)

    Yonezawa, Akiyoshi


    This study examines the historical, current, and future challenges of higher education research in Japan within a global context. Japanese higher education research has been strongly influenced by the international academic community. At the same time, higher education researchers in Japan have participated in international projects, and Japan has…

  2. Higher Education as a Field of Study and Research in Europe (United States)

    Kehm, Barbara M.


    This article describes the emergence of higher education as a field of research, scholarship and study. In the first part, the meaning of higher education as a field of research is defined contrasting Europe and the US. Then, the institutional basis of higher education research in Europe is analysed (learned societies, institutes and centres,…

  3. Symmetry breaking for drag minimization (United States)

    Roper, Marcus; Squires, Todd M.; Brenner, Michael P.


    For locomotion at high Reynolds numbers drag minimization favors fore-aft asymmetric slender shapes with blunt noses and sharp trailing edges. On the other hand, in an inertialess fluid the drag experienced by a body is independent of whether it travels forward or backward through the fluid, so there is no advantage to having a single preferred swimming direction. In fact numerically determined minimum drag shapes are known to exhibit almost no fore-aft asymmetry even at moderate Re. We show that asymmetry persists, albeit extremely weakly, down to vanishingly small Re, scaling asymptotically as Re^3. The need to minimize drag to maximize speed for a given propulsive capacity gives one possible mechanism for the increasing asymmetry in the body plans seen in nature, as organisms increase in size and swimming speed from bacteria like E-Coli up to pursuit predator fish such as tuna. If it is the dominant mechanism, then this signature scaling will be observed in the shapes of motile micro-organisms.

  4. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev; Marston, Jeremy O.; Chan, Derek Y. C.; Thoroddsen, Sigurdur T


    , we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development

  5. Hypersonic wave drag reduction performance of cylinders with repetitive laser energy depositions

    International Nuclear Information System (INIS)

    Fang, J; Hong, Y J; Li, Q; Huang, H


    It has been widely research that wave drag reduction on hypersonic vehicle by laser energy depositions. Using laser energy to reduce wave drag can improve vehicle performance. A second order accurate scheme based on finite-difference method and domain decomposition of structural grid is used to compute the drag performance of cylinders in a hypersonic flow of Mach number 2 at altitude of 15km with repetitive energy depositions. The effects of frequency on drag reduction are studied. The calculated results show: the recirculation zone is generated due to the interaction between bow shock over the cylinder and blast wave produced by energy deposition, and a virtual spike which is supported by an axis-symmetric recirculation, is formed in front of the cylinder. By increasing the repetitive frequency, the drag is reduced and the oscillation of the drag is decreased; however, the energy efficiency decreases by increasing the frequency.

  6. Higher Education Research in Asia: A Publication and Co-Publication Analysis (United States)

    Jung, Jisun; Horta, Hugo


    This study explores higher education research in Asia. Drawing on scientometrics, the mapping of science and social network analysis, this paper examines the publications of 38 specialised journals on higher education over the past three decades. The findings indicate a growing number of higher education research publications but the proportion of…

  7. Modelling of Structural Loads in Drag Augmented Space Debris Removal Concepts

    DEFF Research Database (Denmark)

    Kristensen, Anders Schmidt; Nikolajsen, Jan Ánike; Lauridsen, Peter Riddersholm


    A Self-deployable Deorbiting Space Structure (SDSS) is used for drag augmented space debris removal. A highly flexible frame allows for a folding of the structure by bifurcation. This research models the structural loads during the deployment and unfolding of the drag sail in Low Earth Orbit (LEO......). The Spacecraft travels with 7.8 km/s at deployment. As the drag sail unfolds instantaneously the structure must withstand the loads from the unfolding and the drag. Thermal loads are included in the FEA as the temperature varies from -80°C to +80°C during deorbit. The results are used to verify the structural...

  8. Coulomb drag in the mesoscopic regime

    DEFF Research Database (Denmark)

    Mortensen, N.A.; Flensberg, Karsten; Jauho, Antti-Pekka


    We present a theory for Coulomb drag between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

  9. Identifying Themes for Research-Based Development of Pedagogy and Guidance in Higher Education (United States)

    Jääskelä, Päivikki; Nissilä, Pia


    The high value accorded to the research-based development of education in higher education communities means that researchers in the field have an important role in determining the foci of such efforts. However, it is important to ask whether higher education research is providing answers that satisfy practical educational needs. In this study,…

  10. Current Trends in Higher Education Research in the USSR and in Other Countries of the CMEA. (United States)

    Savelyev, Alexander Y.


    The U.S.S.R.'s Scientific Research Institute for Higher Education Problems and its research efforts are described, and other individual and cooperative efforts for higher education research by member states of the Council for Mutual Economic Assistance are discussed. (MSE)

  11. Further development of drag bodies for the measurement of mass flow rates during blowdown experiments

    International Nuclear Information System (INIS)

    Brockmann, E.; John, H.; Reimann, J.


    Drag bodies have already been used for sometime for the measurement of mass flow rates in blowdown experiments. Former research concerning the drag body behaviour in non-homogeneous two-phase flows frequently dealt with special effects by means of theoretical models only. For pipe flows most investigations were conducted for ratios of drag plate area to pipe cross section smaller 0.02. The present paper gives the results of experiments with drag bodies in a horizontal, non-homogeneous two-phase pipe flow with slip, which were carried through under the sponsorship of the German Ministry for Research and Technology (BMFT). Special interest was layed on the behaviour of the drag coefficient in stationary flows and at various cross sectional ratios. Both design and response of various drag bodies, which were developed at the Battelle-Institut, were tested in stationary and instationary two-phase flows. The influences of density and velocity profiles as well as the drag body position were studied. The results demonstrate, that the drag body is capable of measuring mass flow rates in connection with a gamma densitometer also in non-homogeneous two-phase flows. Satisfying results could be obtained, using simply the drag coefficient which was determined from single-phase flow calibrations

  12. The Internet drag race

    CERN Document Server

    Fitchard, Kevin


    The Internet2 consortium members from California Institute of Technology and CERN developed effective fiber optic network, sending data upto 11,000 kilometers between Caltech's LA laboratories and CERN's campus in Geneva at a rate of 6.25 Gb/s. The 68,431 terabit- meters per second data transfer was accomplished using the IPv4 protocols that power the public Internet. Network run by Internet2, called Abilene maintains the highest capacities in the world, connecting dozens of GigaPOP's with OC-192c 10 Gb/s Ip backbone. The member institutions of Internet2 keep Abilene 10% to 15% full, but the researchers also use the network as a base for the latest Internet technologies and experiments, which include development of IPv6. (Edited abstract).

  13. Coulomb drag in coherent mesoscopic systems

    DEFF Research Database (Denmark)

    Mortensen, Asger; Flensberg, Karsten; Jauho, Antti-Pekka


    We present a theory for Coulomb drag between two mesoscopic systems. Our formalism expresses the drag in terms of scattering matrices and wave functions, and its range of validity covers both ballistic and disordered systems. The consequences can be worked out either by analytic means, such as th......We present a theory for Coulomb drag between two mesoscopic systems. Our formalism expresses the drag in terms of scattering matrices and wave functions, and its range of validity covers both ballistic and disordered systems. The consequences can be worked out either by analytic means......, such as the random matrix theory, or by numerical simulations. We show that Coulomb drag is sensitive to localized states. which usual transport measurements do not probe. For chaotic 2D systems we find a vanishing average drag, with a nonzero variance. Disordered 1D wires show a finite drag, with a large variance...

  14. Effects of Increasing Drag on Conjunction Assessment (United States)

    Frigm, Ryan Clayton; McKinley, David P.


    Conjunction Assessment Risk Analysis relies heavily on the computation of the Probability of Collision (Pc) and the understanding of the sensitivity of this calculation to the position errors as defined by the covariance. In Low Earth Orbit (LEO), covariance is predominantly driven by perturbations due to atmospheric drag. This paper describes the effects of increasing atmospheric drag through Solar Cycle 24 on Pc calculations. The process of determining these effects is found through analyzing solar flux predictions on Energy Dissipation Rate (EDR), historical relationship between EDR and covariance, and the sensitivity of Pc to covariance. It is discovered that while all LEO satellites will be affected by the increase in solar activity, the relative effect is more significant in the LEO regime around 700 kilometers in altitude compared to 400 kilometers. Furthermore, it is shown that higher Pc values can be expected at larger close approach miss distances. Understanding these counter-intuitive results is important to setting Owner/Operator expectations concerning conjunctions as solar maximum approaches.

  15. Higher Education Research in Hong Kong, Japan, China, and Malaysia: Exploring Research Community Cohesion and the Integration of Thematic Approaches (United States)

    Kim, Y.; Horta, H.; Jung, J.


    This article analyzes higher education research published in international higher education journals by researchers from China, Hong Kong, Japan, and Malaysia from 1980 to 2013. It does so based on publication counts, and co-authorship and cross-citation mapping, examining these countries' publication patterns in terms of thematic approach and…

  16. Factors Related to the Adoption of IT Emerging Technologies by Research and Non-Research Based Higher Education Institutions (United States)

    Then, Keri Ann; Amaria, Pesi


    This study examined the adoption of information technology (IT) emerging technology by higher education institutions with a focus on non-research and research based institutions categorized by Carnegie Mellon classifications that are members of EDUCAUSE, a higher education non-profit organization, whose mission is the use of IT in higher…

  17. Malaysian researchers talk about the influence of culture on research misconduct in higher learning institutions. (United States)

    Olesen, Angelina P; Amin, Latifah; Mahadi, Zurina


    Based on a previous survey by the Office of Research Integrity (ORI) in the USA, a considerable number of foreign research scientists have been found guilty of research misconduct. However, it remains unclear as to whether or not cultural factors really contribute to research misconduct. This study is based on a series of interviews with Malaysian researchers from the local universities regarding their own professional experiences involving working with researchers or research students from different countries or of different nationalities. Most of the researchers interviewed agreed that cultures do shape individual character, which influences the way that such individuals conduct research, their decision-making, and their style of academic writing. Our findings also showed that working culture within the institution also influences research practices, as well as faculty mentorship of the younger generation of researchers. Given the fact such misconduct might be due to a lack of understanding of research or working cultures or practices within the institution, the impact on the scientific community and on society could be destructive. Therefore, it is suggested that the institution has an important role to play in orienting foreign researchers through training, mentoring, and discussion with regard to the "does" and "don'ts" related to research, and to provide them with an awareness of the importance of ethics when it comes to conducting research.

  18. On the energy economics of air lubrication drag reduction

    Directory of Open Access Journals (Sweden)

    Simo A. Mäkiharju


    Full Text Available Air lubrication techniques for frictional drag reduction on ships have been proposed by numerous researchers since the 19th century. However, these techniques have not been widely adopted as questions persist about their drag reduction performance beyond the laboratory, as well as energy and economic cost-benefit. This paper draws on data from the literature to consider the suitability of air lubrication for large ocean going and U.S. Great Lakes ships, by establishing the basic energy economic calculations and presenting results for a hypothetical air lubricated ship. All the assumptions made in the course of the analysis are clearly stated so that they can be refined when considering application of air lubrication to a specific ship. The analysis suggests that, if successfully implemented, both air layer and partial cavity drag reduction could lead to net energy savings of 10 to 20%, with corresponding reductions in emissions.

  19. Development of drag disk and turbines at the INEL

    International Nuclear Information System (INIS)

    Goodrich, L.D.; Edson, J.L.; Averill, R.H.


    One of the parameters that must be measured in nuclear safety research is mass flow rate. The reactor environment associated with two-phase flow makes this measurement difficult. To accomplish this at the Idaho National Engineering Laboratory, a drag disk and turbine transducer conbination was developed. These transducers can withstand >2000 h of continuous operation in the reactor environment. Mechanical problems have been solved with these transducers to the point where the electrical coils are now the limiting factor on lifetime. This paper presents the results of the development of the drag disk and turbine with problems and solutions pointed out

  20. Signature Concepts of Women Researchers in Higher Education Teaching and Learning (United States)

    Kandlbinder, Peter


    The history of research into higher education teaching and learning has been one led by male researchers. Individual women researchers have always been active in the field but their contributions have not received the same level of recognition as their male counterparts. A review of the research literature in journals focused on teaching and…

  1. The Effect of Volumetric Porosity on Roughness Element Drag (United States)

    Gillies, John; Nickling, William; Nikolich, George; Etyemezian, Vicken


    Much attention has been given to understanding how the porosity of two dimensional structures affects the drag force exerted by boundary-layer flow on these flow obstructions. Porous structures such as wind breaks and fences are typically used to control the sedimentation of sand and snow particles or create micro-habitats in their lee. Vegetation in drylands also exerts control on sediment transport by wind due to aerodynamic effects and interaction with particles in transport. Recent research has also demonstrated that large spatial arrays of solid three dimensional roughness elements can be used to reduce sand transport to specified targets for control of wind erosion through the effect of drag partitioning and interaction of the moving sand with the large (>0.3 m high) roughness elements, but porous elements may improve the effectiveness of this approach. A thorough understanding of the role porosity plays in affecting the drag force on three-dimensional forms is lacking. To provide basic understanding of the relationship between the porosity of roughness elements and the force of drag exerted on them by fluid flow, we undertook a wind tunnel study that systematically altered the porosity of roughness elements of defined geometry (cubes, rectangular cylinders, and round cylinders) and measured the associated change in the drag force on the elements under similar Reynolds number conditions. The elements tested were of four basic forms: 1) same sized cubes with tubes of known diameter milled through them creating three volumetric porosity values and increasing connectivity between the tubes, 2) cubes and rectangular cylinders constructed of brass screen that nested within each other, and 3) round cylinders constructed of brass screen that nested within each other. The two-dimensional porosity, defined as the ratio of total surface area of the empty space to the solid surface area of the side of the element presented to the fluid flow was conserved at 0.519 for

  2. Literature Review on the Use of Action Research in Higher Education (United States)

    Gibbs, Paul; Cartney, Patricia; Wilkinson, Kate; Parkinson, John; Cunningham, Sheila; James-Reynolds, Carl; Zoubir, Tarek; Brown, Venetia; Barter, Phil; Sumner, Pauline; MacDonald, Angus; Dayananda, Asanka; Pitt, Alexandra


    This literature review considers the use of action research in higher education. The review specifically looks at two areas of higher education activity. The first concerns academic teaching practice and includes a discussion of research and pedagogy practice, and staff development. The second considers student engagement. In both of these core…

  3. The Stories We Need: Anthropology, Philosophy, Narrative and Higher Education Research (United States)

    Scutt, Cecily; Hobson, Julia


    As higher education research is largely practised by those immersed within the university, the questions we ask, and the stories we tell, over time co-create the university itself. Using Bruner's concept of the "narrative mode," we argue for a revaluing of narrative and storytelling within higher education research. We ground our…

  4. Opportunity from Crisis: A Common Agenda for Higher Education and Science, Technology and Innovation Policy Research (United States)

    Jacob, Merle; Hellström, Tomas


    This paper makes a plea for the construction of a common agenda for higher education and science, technology and innovation (STI) policy research. The public higher education and research sector in all countries is currently in the grip of several challenges arising from increased accountability, internationalization and in some cases dwindling…

  5. In Pursuit of Excellence? Discursive Patterns in European Higher Education Research (United States)

    Ramirez, Francisco O.; Tiplic, Dijana


    European higher education is awash with educational reform initiatives that purport to transform universities into better-managed higher quality organizations that more directly contribute to national development. This exploratory study examines patterns of research discourse in higher education in Europe. We argue that these patterns are changing…

  6. Drag reduction effects facilitated by microridges inside the mouthparts of honeybee workers and drones. (United States)

    Li, Chu-Chu; Wu, Jia-Ning; Yang, Yun-Qiang; Zhu, Ren-Gao; Yan, Shao-Ze


    The mouthpart of a honeybee is a natural well-designed micropump that uses a reciprocating glossa through a temporary tube comprising a pair of galeae and labial palpi for loading nectar. The shapes and sizes of mouthparts differ among castes of honeybees, but the diversities of the functional microstructures inside the mouthparts of honeybee workers and drones remain poorly understood. Through scanning electron microscopy, we found the dimensional difference of uniformly distributed microridges on the inner galeae walls of Apis mellifera ligustica workers and drones. Subsequently, we recorded the feeding process of live honeybees by using a specially designed high-speed camera system. Considering the microridges and kinematics of the glossa, we constructed a hydrodynamic model to calculate the friction coefficient of the mouthpart. In addition, we test the drag reduction through the dimensional variations of the microridges on the inner walls of mouthparts. Theoretical estimations of the friction coefficient with respect to dipping frequency show that inner microridges can reduce friction during the feeding process of honeybees. The effects of drag reduction regulated by specific microridges were then compared. The friction coefficients of the workers and drones were found to be 0.011±0.007 (mean±s.d.) and 0.045±0.010, respectively. These results indicate that the mouthparts of workers are more capable of drag reduction compared with those of drones. The difference was analyzed by comparing the foraging behavior of the workers and drones. Workers are equipped with well-developed hypopharyngeal, and their dipping frequency is higher than that of drones. Our research establishes a critical link between microridge dimensions and drag reduction capability during the nectar feeding of honeybees. Our results reveal that microridges inside the mouthparts of honeybee workers and drones reflect the caste-related life cycles of honeybees. Copyright © 2015 Elsevier Ltd

  7. Drag reduction of dense fine-grained slurries

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zdeněk; Štern, Petr


    Roč. 58, č. 4 (2010), s. 261-270 ISSN 0042-790X R&D Projects: GA ČR(CZ) GAP105/10/1574 Institutional research plan: CEZ:AV0Z20600510 Keywords : kaolin slurry * drag reduction * experimental investigation * peptization * slurry rheology Subject RIV: BK - Fluid Dynamics Impact factor: 0.553, year: 2010

  8. Experimental investigation of drag reduction by forward facing high ...

    Indian Academy of Sciences (India)

    Substantial aerodynamic drag, while flying at hypersonic Mach number, due to the presence of strong ... atmospheric flight of hypersonic vehicles, large-angle blunt-cone configurations are preferred at the cost of .... This paper is dedicated to Dr P R Viswanath for his contributions to experimental research in aerodynamics.

  9. Deconstructing Hub Drag. Part 2. Computational Development and Anaysis (United States)


    leveraged a Vertical Lift Consortium ( VLC )-funded hub drag scaling research effort. To confirm this objective, correlations are performed with the...Technology™ Demonstrator aircraft using an unstructured computational solver. These simpler faired elliptical geome- tries can prove to be challenging ...possible. However, additional funding was obtained from the Vertical Lift Consortium ( VLC ) to perform this study. This analysis is documented in

  10. The contact drag of towed demersal fishing gear components (United States)

    O'Neill, F. G.; Summerbell, K.; Ivanović, A.


    The contact demersal towed fishing gears make with the seabed can lead to penetration of the substrate, lateral displacement of the sediment and a pressure field transmitted through the sediment. It will also contribute to the overall drag of the fishing gear. Consequently, there can be environmental effects such as habitat alteration and benthic mortality, and impacts to the fuel efficiency of the fishing operation which will affect emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we present the results of experimental trials that measure the contact drag of a range of elements that represent some of the components of towed demersal gears that are in contact with the seabed. We show that the contact drag of the gear components depends on their weight, geometry, the type of sediment on which they are towed and whether they are rolling or not. As expected, the contact drag of each gear component increases as its weight increases and the drag of fixed elements is greater than that of the rolling ones. The dependence on aspect ratio is more complex and the drag (per unit area) of narrow cylinders is less than that of wider ones when they roll on the finer sediment or are fixed (not permitted to roll) on the coarser sediment. When they roll on the coarse sediment there is no dependence on aspect ratio. Our results also suggest that fixed components may penetrate the seabed to a lesser depth when they are towed at higher speeds but when they roll there is no such relationship.

  11. Drag and drop display & builder

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, Timofei B.; Petrov, Andrey D.; /Fermilab


    The Drag and Drop (DnD) Display & Builder is a component-oriented system that allows users to create visual representations of data received from data acquisition systems. It is an upgrade of a Synoptic Display mechanism used at Fermilab since 2002. Components can be graphically arranged and logically interconnected in the web-startable Project Builder. Projects can be either lightweight AJAX- and SVG-based web pages, or they can be started as Java applications. The new version was initiated as a response to discussions between the LHC Controls Group and Fermilab.

  12. Research Performance of Higher Education Institutions: A Review on the Measurements and Affecting Factors of Research Performance

    Directory of Open Access Journals (Sweden)



    Full Text Available Recently, the increasing competition in higher education has attracted attention by many researchers. They have emphasized that the aim of the growing competition between universities is to increase the number of students, the research performance and get research support, find qualified faculty members, and receive financial contributions. This paper aims to draw attention to “research performance” which is a significant part of the competition among the universities. In connection with this goal, the study tries to outline the results of an extensive literature review in the field of higher education research performance. Firstly, literature regarding research performance, its definition as a concept, and its indicators are discussed. Then, the factors influencing research performance are presented in a comprehensive manner. At the end of the study, a conceptual framework that will be useful for all university staff is provided. Understanding the concept of research performance and the factors affecting research performance can help relevant authorities improve their current positions.

  13. Drag Reduction by Riblets & Sharkskin Denticles: A Numerical Study (United States)

    Boomsma, Aaron

    Riblet films are a passive method of turbulent boundary layer control that can reduce viscous drag. They have been studied with great detail for over 30 years. Although common riblet applications include flows with Adverse Pressure Gradients (APG), nearly all research thus far has been performed in channel flows. Recent research has provided motivation to study riblets in more complicated turbulent flows with claims that riblet drag reduction can double in mild APG common to airfoils at moderate angles of attack. Therefore, in this study, we compare drag reduction by scalloped riblet films between riblets in a zero pressure gradient and those in a mild APG using high-resolution large eddy simulations. In order to gain a fundamental understanding of the relationship between drag reduction and pressure gradient, we simulated several different riblet sizes that encompassed a broad range of s + (riblet width in wall units), similarly to many experimental studies. We found that there was only a slight improvement in drag reduction for riblets in the mild APG. We also observed that peak values of streamwise turbulence intensity, turbulent kinetic energy, and streamwise vorticity scale with riblet width. Primary Reynolds shear stresses and turbulence kinetic energy production however scale with the ability of the riblet to reduce skin-friction. Another turbulent roughness of similar shape and size to riblets is sharkskin. The hydrodynamic function of sharkskin has been under investigation for the past 30 years. Current literature conflicts on whether sharkskin is able to reduce skin friction similarly to riblets. To contribute insights toward reconciling these conflicting views, Direct Numerical Simulations (DNS) are carried out to obtain detailed flow fields around realistic denticles. A sharp interface immersed boundary method is employed to simulate two arrangements of actual sharkskin denticles (from Isurus oxyrinchus) in a turbulent boundary layer at Retau ≈ 180

  14. Surface pressure drag for hydrostatic two-layer flow over axisymmetric mountains

    Energy Technology Data Exchange (ETDEWEB)

    Leutbecher, M.


    The effect of partial reflections on surface pressure drag is investigated for hydrostatic gravity waves in two-layer flow with piecewise constant buoyancy frequency. The variation of normalized surface pressure drag with interface height is analyzed for axisymmetric mountains. The results are compared with the familiar solution for infinitely long ridges. The drag for the two-layer flow is normalized with the drag of one-layer flow, which has the buoyancy frequency of the lower layer. An analytical expression for the normalized drag of axisymmetric mountains is derived from linear theory of steady flow. Additionally, two-layer flow over finite-height axisymmetric mountains is simulated numerically for flow with higher stability in the upper layer. The temporal evolution of the surface pressure drag is examined in a series of experiments with different interface and mountain heights. The focus is on the linear regime and the nonlinear regime of nonbreaking gravity waves. The dispersion of gravity waves in flow over isolated mountains prevents that the entire wave spectrum is in resonance at the same interface height, which is the case in hydrostatic flow over infinitely long ridges. In consequence, the oscillation of the normalized drag with interface height is smaller for axisymmetric mountains than for infinitely long ridges. However, even for a reflection coefficient as low as 1/3 the drag of an axisymmetric mountain can be amplified by 50% and reduced by 40%. The nonlinear drag becomes steady in the numerical experiments in which no wave breaking occurs. The steady state nonlinear drag agrees quite well with the prediction of linear theory if the linear drag is computed for a slightly lowered interface. (orig.)

  15. Euratom research and training in nuclear reactor safety: Towards European research and the higher education area

    International Nuclear Information System (INIS)

    Goethem, G. van


    In this invited lecture, research and training in nuclear fission are looked at from a European perspective with emphasis on the three success factors of any European policy, namely: common needs, vision and instruments, that ought to be strongly shared amongst the stakeholders across the Member States concerned. As a result, the following questions are addressed: What is driving the current EU trend towards more research, more education and more training, in general? Regarding nuclear fission, in particular, who are the end-users of Euratom 'research and training' and what are their expectations from EU programmes? Do all stakeholders share the same vision about European research and training in nuclear fission? What are the instruments proposed by the European Commission (EC) to conduct joint research programmes of common interest for the nuclear fission community? In conclusion, amongst the stakeholders in Europe, there seems to be a wide consensus about common needs and instruments, but not about a common vision regarding nuclear. (author)

  16. Coulomb drag in the mesoscopic regime

    DEFF Research Database (Denmark)

    Mortensen, N. Asger; Flensberg, Karsten; Jauho, Antti-Pekka


    We present a theory for Coulomb drug between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

  17. DOE Project on Heavy Vehicle Aerodynamic Drag

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, R; Salari, K; Ortega, J; Castellucci, P; Pointer, D; Browand, F; Ross, J; Storms, B


    Class 8 tractor-trailers consume 11-12% of the total US petroleum use. At highway speeds, 65% of the energy expenditure for a Class 8 truck is in overcoming aerodynamic drag. The project objective is to improve fuel economy of Class 8 tractor-trailers by providing guidance on methods of reducing drag by at least 25%. A 25% reduction in drag would present a 12% improvement in fuel economy at highway speeds, equivalent to about 130 midsize tanker ships per year. Specific goals include: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; (2) Develop innovative drag reducing concepts that are operationally and economically sound; and (3) Establish a database of experimental, computational, and conceptual design information, and demonstrate the potential of new drag-reduction devices. The studies described herein provide a demonstration of the applicability of the experience developed in the analysis of the standard configuration of the Generic Conventional Model. The modeling practices and procedures developed in prior efforts have been applied directly to the assessment of new configurations including a variety of geometric modifications and add-on devices. Application to the low-drag 'GTS' configuration of the GCM has confirmed that the error in predicted drag coefficients increases as the relative contribution of the base drag resulting from the vehicle wake to the total drag increases and it is recommended that more advanced turbulence modeling strategies be applied under those circumstances. Application to a commercially-developed boat tail device has confirmed that this restriction does not apply to geometries where the relative contribution of the base drag to the total drag is reduced by modifying the geometry in that region. Application to a modified GCM geometry with an open grille and radiator has confirmed that the underbody flow, while important for underhood cooling, has little impact on the drag

  18. Scientific Research in Jordanian Higher Education Institutions: An Evaluation of the Status and Obstacles (United States)

    bin Tareef, Atif


    This study aimed at identifying the status and obstacles of scientific research in Jordanian higher education institutions. And defined by being an attempt to increase faculty member's, researcher's and educational leader's attention to the necessity of improving research planning or strategies, professional development, working conditions,…

  19. The Interface between Research and Policy--A Note with Potential Relevance for Higher Education (United States)

    Gornitzka, Åse


    The nexus between research and policy in higher education as in other sectors of society is multimodal and not adequately captured by the notion of a cultural gap between the world of practice and the world of research. Neither can the relationship be seen as unidirectional. This paper sketches out the range of uses of research in policy-making,…

  20. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium. (United States)

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu


    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  1. Improvements of evaporation drag model

    International Nuclear Information System (INIS)

    Li Xiaoyan; Yang Yanhua; Xu Jijun


    A special observable experiment facility has been established, and a series of experiments have been carried out on this facility by pouring one or several high-temperature particles into a water pool. The experiment has verified the evaporation drag model, which believe the non-symmetric profile of the local evaporation rate and the local density of the vapor would bring about a resultant force on the hot particle so as to resist its motion. However, in Yang's evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot particle to the vapor-liquid interface and all of the radiation energy is deposited on the vapor-liquid interface, thus contributing to the vaporization rate and mass balance of the vapor film. So, the heat conduction and the heat convection are taken into account in improved model. At the same time, the improved model given by this paper presented calculations of the effect of hot particles temperature on the radiation absorption behavior of water

  2. Using Interdisciplinary and Active Research to Encourage Higher Resolution Research and Prototyping in Design

    Directory of Open Access Journals (Sweden)

    Adream Blair-Early


    Full Text Available University art and design programs are branching out and creating interdisciplinary programs and research centers that connect design students and faculty across various disciplines such as business, engineering, architecture, information studies, health sciences and education. A human-centered, problem-based approach to design research looks to position industry and academic leaders to work alongside students, community leaders, artists and non-profits to develop creative and innovative solutions to the challenges facing contemporary society. But product design benefits even more from practices that engage users throughout the entire design process, often called participatory design. Participatory design process utilizes user feedback throughout the design process to spur innovation and improve design quality. It is possible in the classroom to engage in participatory design and participatory prototyping through the use of inexpensive 3D printers and laser cutters as well as traditional hand tools, requiring only mastery of a few simple techniques and technology readily available on laptop computers. The class research being presented was conceived as part of a new interdisciplinary classroom research space call the Digital Craft Research Lab (DCRL housed within the department of Art and Design. Courses taught within the DCRL offer students, researchers and faculty continual access to both low resolution and high-resolution prototyping machinery and materials. This paper looks at the role of action and participatory research in a design course that created printed hand innovations in collaboration with a nine-year-old female user. Students were asked to work on modeling new designs as well as capturing the progress in a final open source book and models. This paper asks the question can the use of classroom collaboration, action research and work spaces encourage creativity, innovation, and critical thinking in student and professional

  3. Effect of structure height on the drag reduction performance using rotating disk apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Rashed, Musaab K; Salleh, Mohamad Amran Mohd; Ismail, M Halim Shah [Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia (Malaysia); Abdulbari, Hayder A, E-mail: [Center of Excellence for Advanced Research in Fluid Flow, Universiti Malaysia Pahang (Malaysia)


    The drag reduction characteristics in a rotating disk apparatus were investigated by using structured disks with different riblet types and dimensions. Two disk types were fabricated with right angle triangular (RAT) grooves and space v-shape (SV) grooves, with six dimensions for each type. A high-accuracy rotating disk apparatus was fabricated and then used to investigate the turbulent drag reduction characterization of the disk in diesel fuel. In this work, the effects of several parameters are investigated; riblet types, riblet dimensions, and rotational disk speed (rpm) on the drag reduction performance. It was found that the surface structure of the disk reduced the drag, this was clearly seen from the comparison of torque values of smooth and structured disks. Drag reduction for structured disks was higher than that for smooth disks, and SV-grooves showed better drag reduction performance than RAT-grooves. In addition, it was observed that the drag reduction performance increased with decreasing groove height for both groove types. The maximum drag reduction achieved in this study was 37.368% for SV-groove at 1000 rpm, compared with 30% for RAT-groove, at the same rotational speed. (paper)


    Directory of Open Access Journals (Sweden)

    Fabricio Baron Mussi


    Full Text Available This paper aims to define a proposition for a characterization of indicators applicable to evaluate joint research results. In order to do that, literature on interinstitutional cooperation, exchange programs and indicators was assessed, and its guidelines, adopted. Ten cases were selected for evaluation, and the following procedures undertaken: visits to receptor institutions in several cities; visits to workplace where the subjected projects were being developed; interviews with project managers and visiting researchers; interviews with other personnel; review of the approved projects' official documentation collected during the previous steps; and a new contact with the respondents to clarify eventual doubts. Theoretically, this research contributes to the development of a proposal of a set of indicators to characterize and evaluate interdisciplinary cooperation between researchers from universities and distinct research institutes. Practical contributions to be mentioned are the information gathered that can help promotion agencies to improve their supporting edicts offered to scientific and technological development, as well as upgrading their evaluation systems regarding such actions.

  5. Race, Ethnicity, and Higher Education Policy: The Use of Critical Quantitative Research (United States)

    Teranishi, Robert T.


    Cross-sectional frameworks, or between-group approaches, in quantitative research in higher education have limitations that hinder what we know about the intersection of race and educational opportunities and outcomes. (Contains 5 figures.)

  6. Superhydrophobic and polymer drag reduction in turbulent Taylor-Couette flow (United States)

    Rajappan, Anoop; McKinley, Gareth H.


    We use a custom-built Taylor-Couette apparatus (radius ratio η = 0.75) to study frictional drag reduction by dilute polymer solutions and superhydrophobic (SH) surfaces in turbulent flows for 15000 analysis. We also investigate drag reduction by dilute polymer solutions, and show that natural biopolymers from plant mucilage can be an inexpensive and effective alternative to synthetic polymers in drag reduction applications, approaching the same maximum drag reduction asymptote. Finally we explore combinations of the two methods - one arising from wall slip and the other due to changes in turbulence dynamics in the bulk flow - and find that the two effects are not additive; interestingly, the effectiveness of polymer drag reduction is drastically reduced in the presence of an SH coating on the wall. This study was financially supported by the Office of Naval Research (ONR) through Contract No. 3002453814.

  7. Exploring Reticence in Research Methods: The Experience of Studying Psychological Research Methods in Higher Education (United States)

    Kingsley, Barbara E.; Robertson, Julia M.


    As a fundamental element of any psychology degree, the teaching and learning of research methods is repeatedly brought into sharp focus, and it is often regarded as a real challenge by undergraduate students. The reasons for this are complex, but frequently attributed to an aversion of maths. To gain a more detailed understanding of students'…

  8. The Effect of Sodium Hydroxide on Drag Reduction using a Biopolymer.

    Directory of Open Access Journals (Sweden)

    Singh Harvin Kaur A/P Gurchran


    Full Text Available Drag reduction is observed as reduced frictional pressure losses under turbulent flow conditions and hence, substantially increases the flowrate of the fluid. Practical application includes water flooding system, pipeline transport and drainage system. Drag reduction agent, such as polymers, can be introduced to increase the flowrate of water flowing, reducing the water accumulation in the system and subsequently lesser possibility of heavy flooding. Currently used polymer as drag reduction agents is carboxymethylcellulose, to name one. This is a synthetic polymer which will seep into the ground and further harm our environment in excessive use of accumulation. A more environmentally-friendly drag reduction agent, such as the polymer derived from natural sources or biopolymer, is then required for such purpose. As opposed to the synthetic polymers, the potential of biopolymers as drag reduction agents, especially those derived from a local plant source, are not extensively explored. The drag reduction of a polymer produced from a local plant source within the turbulent regime will be explored and assessed in this study using a rheometer where a reduced a torque produced can be perceived as a reduction of drag. The cellulose powder was converted to carboxymethylcellulose (CMC by etherification process using sodium monochloroacetate and sodium hydroxide. The carboxymethylation reaction then was optimized against concentration of NaOH. The research is structured to focus on producing the biopolymer and also assess the drag reduction ability of the biopolymer produced against concentration of sodium hydroxide.

  9. Research and higher education background of the Paks Nuclear Power Plant, Hungary. Past and present

    International Nuclear Information System (INIS)

    Csom, Gy.


    The connection of the Paks Nuclear Power Plant, Hungary, with research and development as well as with higher education is discussed. The main research areas include reactor physics, thermohydraulics, radiochemistry and radiochemical analysis, electronics and nuclear instruments, computers, materials science. The evolution of relations with higher education in Hungary and the PNPP is presented, before and after the installation of the various units. (R.P.)

  10. Measurements of the Drag Coefficient of Simulated Micrometeoroids (United States)

    DeLuca, M.; Munsat, T.; Sternovsky, Z.


    The dust accelerator facility operated at the University of Colorado is used to simulate meteoric ablation, including measuring the ionization efficiency over a wide range of velocities (e.g., DeLuca et al., Planet. Space Sci., submitted, 2017). This presentation reports on the most recent experimental measurements of the drag coefficient that determines the particles' slowdown from their frictional interaction with the atmosphere. The measurements indicate that meteors experience considerably more slowdown than usually assumed. The simulated meteors consisted of submicron sized aluminum particles shot into an air chamber held at 200 mTorr pressure at velocities between 1 - 10 km/s using the dust accelerator and meteor ablation facility. The slowdown is calculated from precise timing measurements made using pickup tube detectors placed upstream and near the entrance to the air chamber, and an impact detector inside the air chamber at the downstream end of the chamber. Supporting modeling calculations show that the particles have little or no mass loss during their interaction with air and thus constant radius can be assumed. Preliminary results for the drag coefficient calculated from these timing measurements reveal that the aluminum particles have a drag coefficient of 1.51 ± 0.24 in air, which is higher than typically assumed in meteoric ablation models (usually 0.5 to 1), indicating that meteors may experience more air drag than previously assumed. More detailed measurements over a wider parameter range are underway.

  11. Review of the Research Literature on Defining and Demonstrating Quality Teaching and Impact in Higher Education (United States)

    Strang, Lucy; Bélanger, Julie; Manville, Catriona; Meads, Catherine


    In March 2016, the Higher Education Academy (HEA) commissioned RAND Europe to conduct a literature review of research published since 2012, with the aim of identifying and summarising the key trends and issues in the literature on how "quality teaching" and its impact are currently being defined and demonstrated at higher education…

  12. Understanding Critical Race Theory as a Framework in Higher Educational Research (United States)

    Savas, Gokhan


    This paper reviews the existing literature to discuss how critical race theory has been applied as a theoretical framework to higher educational research in the United States and what its contributions are. To provide necessary context, I will discuss race and racism in the United States, the background of US higher education in relation to race,…

  13. Researching Higher Education in "Asia's Global Education Hub": Trends and Issues in Singapore (United States)

    Lee, Michael H.


    Higher education studies as a field of academic research has become more developed and important in Singapore since the 1980s when the city-state placed more emphasis on reforming and restructuring its higher education sector to achieve the status of "Asia's global education hub". The past few decades witnessed a more significant growth…

  14. Signature Concepts of Key Researchers in Higher Education Teaching and Learning (United States)

    Kandlbinder, Peter


    Early career university teachers often have limited experience of the higher education literature making it difficult for them to identify what ideas have become central to justifying what university teachers ought to be doing in higher education teaching and learning. A review of the research literature in journals focused on teaching and…

  15. Trends and Developments of Higher Education Research in Hong Kong: In Pursuit of a Cosmopolitan Vision (United States)

    Lo, William Yat Wai; Ng, Felix Sai Kit


    With the processes of inter- and intranationalization, higher education in Hong Kong has been rapidly expanding in an effort to develop the city into a regional education hub. This article explores the trends and developments of higher education research (HER) in Hong Kong in the context of inter- and intranationalization. By drawing on the data…

  16. Working in Separate Silos? What Citation Patterns Reveal about Higher Education Research Internationally (United States)

    Tight, Malcolm


    Higher education research is a growing, inter-disciplinary and increasingly international field of study. This article examines the citation patterns of articles published in six leading higher education journals--three published in the United States and three published elsewhere in the world--for what they reveal about the development of this…

  17. Research on Five Stakeholders & Five Relationships of Higher Engineering Education in China


    Guangshe Jia; Chengbin Xiao


    With the development of globalization, higher engineering education has been on the rise which includes five Stakeholders and five relationships. This paper will discuss five relations of higher engineering education: teaching, research and social services, professional education and humanity education, ability education and knowledge education, theoretical teaching and practical teaching, development of education and development of national and regional economy. Among them, teaching, researc...

  18. Uncovering the Images and Meanings of International Organizations (IOs) in Higher Education Research (United States)

    Shahjahan, Riyad A.; Madden, Meggan


    Employing Stuart Hall's concept of representation, we examine how international organizations (IOs) are presented in the higher education literature. This paper examines how IOs, such as the World Bank, OECD, and UNESCO, are conceptualized and represented by higher education researchers. We focus on three main representations of IOs in the higher…

  19. Handbook of Research on Higher Education in the MENA Region: Policy and Practice (United States)

    Baporikar, Neeta, Ed.


    As the Middle East and North Africa (MENA) region becomes increasingly intertwined in the global economy, investment continues to be made in the educational sector. Multidimensional approaches to higher education have greatly influenced the state of business and government in the region. The "Handbook of Research on Higher Education in the…

  20. Three Decades of Implementation Research in Higher Education: Limitations and Prospects of Theory Development (United States)

    Kohoutek, Jan


    The article adopts a comparative approach to review three periods of theory development in research into higher education policy implementation. Given the conceptual affinity between Cerych and Sabatier's 1986 seminal study into higher education policy implementation and public policy implementation theory, the field of public policy is chosen for…

  1. Determination of the surface drag coefficient

    DEFF Research Database (Denmark)

    Mahrt, L.; Vickers, D.; Sun, J.L.


    This study examines the dependence of the surface drag coefficient on stability, wind speed, mesoscale modulation of the turbulent flux and method of calculation of the drag coefficient. Data sets over grassland, sparse grass, heather and two forest sites are analyzed. For significantly unstable...... conditions, the drag coefficient does not depend systematically on z/L but decreases with wind speed for fixed intervals of z/L, where L is the Obukhov length. Even though the drag coefficient for weak wind conditions is sensitive to the exact method of calculation and choice of averaging time, the decrease...... of the drag coefficient with wind speed occurs for all of the calculation methods. A classification of flux calculation methods is constructed, which unifies the most common previous approaches. The roughness length corresponding to the usual Monin-Obukhov stability functions decreases with increasing wind...

  2. Intellectual Leadership of Researchers in Higher Education: Relationship Between the Demographic Factors and Roles (Lithuanian Context

    Directory of Open Access Journals (Sweden)

    Žydžiūnaitė Vilma


    Full Text Available The intellectual leadership of educators or teachers represents a topic of a great interest for educational research and practice. Variety of variables or factors have been examined to find the most complete explanations for teachers’, professors’ and educators’ roles, for example, institutional, financial, gender, organizational, spiritual, and intellectual. No literature was found on the relationship between the demographic variables and researchers’ roles in higher education regarding intellectual leadership. But a lot of studies are focused on the relationship between demographic and other factors in education: job satisfaction, organizational justice, religion, gender, culture, personal and professional roles, stress, mental health, and mobility. The research issue in this study is related to researchers’/scientists’ work in higher education schools and is focused on intellectual leadership, which consists of different roles. It is worth to think about researchers as intellectual leaders and to discover how they recognize or identify their roles in higher education. In this study, findings answer the following research question: “What are the relationships between researchers’ roles and their gender, work experience, dissertation defence date, and research field?” The object of the research study is the researchers’ roles in higher education. The aim of the study was to reveal the relationship between demographic factors and researchers’ roles in higher education. Data were collected by performing a questioning survey and using a validated questionnaire with 116 statements in total. The sample consisted of 304 researchers working in higher education institutions. For data analysis, Cronbach’s alpha, Mean and ANOVA calculations were used. The research findings reported that the female-researchers’ evaluations were higher in all cases regarding their roles in higher education schools. The results of the study

  3. Contemporary Research Discourse and Issues on Big Data in Higher Education (United States)

    Daniel, Ben


    The increasing availability of digital data in higher education provides an extraordinary resource for researchers to undertake educational research, targeted at understanding challenges facing the sector. Big data can stimulate new ways to transform processes relating to learning and teaching, and helps identify useful data, sources of evidence…

  4. Higher Education Research Expenditure in South Africa: A Review of the New Funding Framework (United States)

    Odhiambo, Nicholas M.; Ntenga, Lydia


    The trends and the trajectory of higher education research expenditure in South Africa since the introduction of the New Funding Formula in 2004 have been analysed. The paper also compares the level of South Africa's total gross expenditure on research and development with those of other selected economies. The findings show that following…

  5. Reflections on Teaching and Research: Two Inseparable Components in Higher Education (United States)

    Chan Fong Yee, Fanny


    Teaching and research are two inseparable components in higher education. There are continuous debates about the relationship between the two. Does good teaching always lead to good research, and vice versa? This paper critically examines the impact of current policy on the two academic practices and discusses how it shapes one's professional…

  6. How Often Are Theories Developed through Empirical Research into Higher Education? (United States)

    Ashwin, Paul


    This article reports on a review of empirical research published in selected higher education journals in 2008, which was focused on examining how often theories are developed through research. This review found relatively little evidence of theory development. Drawing on the notions of internal and external languages of description, it is argued…

  7. Cross-Border Higher Education in China: How the Field of Research Has Developed (United States)

    Qin, Yunyun; Te, Alice Y. C.


    The aim of the research was to investigate how the field of cross-border Chinese higher education has developed from 1990 to 2015. Ninety-five articles in international journals and 470 articles in national journals were collected and analyzed in terms of authorship pattern, thematic clusters, and research methods. Results show that cross-border…

  8. Educational Technology Research Journals: "The Internet and Higher Education", 2001-2010 (United States)

    Drysdale, Jeffery S.; Matthews, Michael; Terekhova-Nan, Vera; Woodfield, Wendy; West, Richard E.


    This article analyzes articles published in "The Internet and Higher Education" from 2001-2010. The researchers analyzed the frequency of author-provided keywords and common abstract words, type and frequency of authorship, the type of research method employed, and the number of citations the journal and specific articles received. Words…

  9. Implementing Research in Professional Higher Education: Factors That Influence Lecturers' Perceptions (United States)

    Griffioen, Didi M. E.; de Jong, Uulkje


    Higher professional education in Europe has changed from teaching-only institutes to hybrids of teaching and research. The purpose of this study was to examine factors that influence the judgements of lecturers about new organisational goals and perceptions of their new research-related competencies. Lecturers' judgements of new organisational…

  10. Separability of drag and thrust in undulatory animals and machines (United States)

    Bale, Rahul; Shirgaonkar, Anup A.; Neveln, Izaak D.; Bhalla, Amneet Pal Singh; Maciver, Malcolm A.; Patankar, Neelesh A.


    For nearly a century, researchers have tried to understand the swimming of aquatic animals in terms of a balance between the forward thrust from swimming movements and drag on the body. Prior approaches have failed to provide a separation of these two forces for undulatory swimmers such as lamprey and eels, where most parts of the body are simultaneously generating drag and thrust. We nonetheless show that this separation is possible, and delineate its fundamental basis in undulatory swimmers. Our approach unifies a vast diversity of undulatory aquatic animals (anguilliform, sub-carangiform, gymnotiform, bal-istiform, rajiform) and provides design principles for highly agile bioinspired underwater vehicles. This approach has practical utility within biology as well as engineering. It is a predictive tool for use in understanding the role of the mechanics of movement in the evolutionary emergence of morphological features relating to locomotion. For example, we demonstrate that the drag-thrust separation framework helps to predict the observed height of the ribbon fin of electric knifefish, a diverse group of neotropical fish which are an important model system in sensory neurobiology. We also show how drag-thrust separation leads to models that can predict the swimming velocity of an organism or a robotic vehicle.

  11. Future Drag Measurements from Venus Express (United States)

    Keating, Gerald; Mueller-Wodarg, Ingo; Forbes, Jeffrey M.; Yelle, Roger; Bruinsma, Sean; Withers, Paul; Lopez-Valverde, Miguel Angel; Theriot, Res. Assoc. Michael; Bougher, Stephen

    thermospheric drag effects over the last 30 years. The Venus Express drag experiments will allow a global empirical model of the thermosphere to emerge. This new model will be a substantial improvement over the Venus International Reference Atmosphere, which was based principally on near equatorial measurements. General Circulation Models (GCM's) and other models will be generated that are in fair accord with the empirical models. The experiment may help us understand, on a global scale, tides, winds, gravity waves, planetary waves and the damping of waves. Comparisons will be made between low and high latitude results; between the middle and upper atmosphere; and with other instruments that provide information from current and previous measurements. The character of the sharp temperature gradient near the day/night terminator needs to be studied at all latitudes. The cryosphere we discovered on the nightside needs to be studied at high latitudes. The vortex dipole over the North Pole surrounded by a colder "collar" needs to be analyzed to identify how wave activity extends into the polar thermosphere. We have already discovered super-rotation in the equatorial thermosphere, but we need to study 4-day super-rotation at higher latitudes to obtain a global picture of the thermosphere. The observed global cooling from radiative effects of 15 micron excitation of CO2 by atomic oxygen should improve our understanding of global thermospheric cooling on Earth and Mars as well.

  12. Gliding flight: drag and torque of a hawk and a falcon with straight and turned heads, and a lower value for the parasite drag coefficient. (United States)

    Tucker, V A


    Raptors - falcons, hawks and eagles in this study - such as peregrine falcons (Falco peregrinus) that attack distant prey from high-speed dives face a paradox. Anatomical and behavioral measurements show that raptors of many species must turn their heads approximately 40 degrees to one side to see the prey straight ahead with maximum visual acuity, yet turning the head would presumably slow their diving speed by increasing aerodynamic drag. This paper investigates the aerodynamic drag part of this paradox by measuring the drag and torque on wingless model bodies of a peregrine falcon and a red-tailed hawk (Buteo jamaicensis) with straight and turned heads in a wind tunnel at a speed of 11.7 m s(-)(1). With a turned head, drag increased more than 50 %, and torque developed that tended to yaw the model towards the direction in which the head pointed. Mathematical models for the drag required to prevent yawing showed that the total drag could plausibly more than double with head-turning. Thus, the presumption about increased drag in the paradox is correct. The relationships between drag, head angle and torque developed here are prerequisites to the explanation of how a raptor could avoid the paradox by holding its head straight and flying along a spiral path that keeps its line of sight for maximum acuity pointed sideways at the prey. Although the spiral path to the prey is longer than the straight path, the raptor's higher speed can theoretically compensate for the difference in distances; and wild peregrines do indeed approach prey by flying along curved paths that resemble spirals. In addition to providing data that explain the paradox, this paper reports the lowest drag coefficients yet measured for raptor bodies (0.11 for the peregrine and 0.12 for the red-tailed hawk) when the body models with straight heads were set to pitch and yaw angles for minimum drag. These values are markedly lower than value of the parasite drag coefficient (C(D,par)) of 0.18 previously

  13. Mechanism of drag reduction for circular cylinders with patterned surface

    International Nuclear Information System (INIS)

    Butt, U.; Jehring, L.; Egbers, C.


    Highlights: • Reduced drag of patterned cylinders over a wide range of Re numbers. • Hexagonal patterns cannot be characterized as roughness structures. • Hexagonal bumps affect the flow like spherical dimples of smaller k/d ratio do. • Main separation is delayed caused by a partial separation. • Angle of a separation line is not constant over the length of cylinder. -- Abstract: In this paper, the flow over cylinders with a patterned surface (k/d = 1.98 × 10 −2 ) is investigated in a subsonic wind tunnel over Reynolds numbers ranging from 3.14 × 10 4 to 2.77 × 10 5 by measuring drag, flow visualization and measuring velocity profiles above the surface of the cylinders, to observe the effect of hexagonal patterns on the flow of air. These patterns can also be referred as hexagonal dimples or bumps depending on their configuration. The investigations revealed that a patterned cylinder with patterns pressed outwards has a drag coefficient of about 0.65 times of a smooth one. Flow visualization techniques including surface oil-film technique and velocity profile measurement were employed to elucidate this effect, and hence present the mechanism of drag reduction. The measurement of velocity profiles using hot-wire anemometry above the surface reveal that a hexagonal bump cause local separation generating large turbulence intensity along the separating shear layer. Due to this increased turbulence, the flow reattaches to the surface with higher momentum and become able to withstand the pressure gradient delaying the main separation significantly. Besides that, the separation does not appear to occur in a straight line along the length of the cylinder as in case of most passive drag control methods, but follow exactly the hexagonal patterns forming a wave with its crest at 115° and trough at 110°, in contrast to the laminar separation line at 85° for a smooth cylinder

  14. Authentic scientific research in an international setting as a path toward higher education (United States)

    Mladenov, N.; Palomo, M.; Casad, B.; Pietruschka, B.; Buckley, C.


    Studies have shown that undergraduate research opportunities foster student interest in research, encourage minority students to seek advanced degrees, and put students on a path toward higher education. It has been further suggested that engineering projects in international settings address issues of sustainability and promote a connection between engineering and social welfare that may compel students to seek future research opportunities. In this study, we explored the role that authentic research experiences in an international setting play in promoting higher education for students from groups typically under-represented in engineering and sciences. We hypothesized that the international context of the research experiences will provide undergraduate and graduate students with a global perspective of water reuse challenges and promote increased interest in pursuing a higher degree in engineering. Through the Sustainable Sanitation International Research Experiences for Students (IRES) Program, US students conducting research in Durban, South Africa in 2015 and 2016, were tasked with leading 6-week long research projects, collaborating with partners at the University of KwaZulu Natal, and producing papers and presentations for regional and international scientific conferences. All undergraduate participants were from groups under-represented in the sciences. Pre- and post-program survey results revealed that, after completing the program, participants of Cohort 1 had 1) greater research skills, 2) greater identification as an engineer, and 3) stronger intentions to pursue a PhD in engineering. Survey data were also used to evaluate comfort with cultural diversity before and after the international program and the effect of pairing US with South African student researchers. Our results indicate that students' awareness of societal needs and engineering challenges faced in Durban resulted in a positive impact on each student. The benefits gained from the

  15. On the Effect of Rigid Swept Surface Waves on Turbulent Drag (United States)

    Denison, M.; Wilkinson, S. P.; Balakumar, P.


    Passive turbulent drag reduction techniques are of interest as a cost effective means to improve air vehicle fuel consumption. In the past, rigid surface waves slanted at an angle from the streamwise direction were deemed ineffective to reduce skin friction drag due to the pressure drag that they generate. A recent analysis seeking similarities to the spanwise shear stress generated by spatial Stokes layers suggested that there may be a range of wavelength, amplitude, and orientation in which the wavy surface would reduce turbulent drag. The present work explores, by experiments and Direct Numerical Simulations (DNS), the effect of swept wavy surfaces on skin friction and pressure drag. Plates with shallow and deep wave patterns were rapid-prototyped and tested using a drag balance in the 7x11 inch Low-Speed Wind Tunnel at the NASA LaRC Research Center. The measured drag o set between the wavy plates and the reference at plate is found to be within the experimental repeatability limit. Oil vapor flow measurements indicate a mean spanwise flow over the deep waves. The turbulent flow in channels with at walls, swept wavy walls and spatial Stokes spanwise velocity forcing was simulated at a friction Reynolds number of two hundred. The time-averaged and dynamic turbulent flow characteristics of the three channel types are compared. The drag obtained for the channel with shallow waves is slightly larger than for the at channel, within the range of the experiments. In the case of the large waves, the simulation over predicts the drag. The shortcomings of the Stokes layer analogy model for the estimation of the spanwise shear stress and drag are discussed.

  16. The Process of Change in Higher Education Institutions. AAHE-ERIC/Higher Education Research Report, No. 7, 1982. (United States)

    Nordvall, Robert C.

    Conditions that inhibit change in higher education institutions and various models of the change process are described. Attention is also directed to: organizational character, structural features, planning procedures, key individuals in the change process, and practical advice about change. The major change models for higher education…

  17. Developments in Transnational Research Collaborations: Evidence from U.S. Higher-education Activity

    Directory of Open Access Journals (Sweden)

    Peter H Koehn


    Full Text Available In our knowledge-driven era, multiple and mutual benefits accrue from transnational research linkages. The article identifies important directions in transnational research collaborations involving U.S. universities revealed by key dimensions of 369 projects profiled on a U.S. higher-education association’s database. Project initiators, principal research fields, regional and country distributions, and the sources and amounts of funding for different types of transnational research activity are selected for analysis. The balanced total portfolio of reported current research projects by region suggests that U.S. university principal investigators increasingly recognize the value of collaborative knowledge generation in the Global South as well as in other OECD countries. The data also show concentrations in the distribution of transnational research projects by principal field of activity that could exacerbate intra-regional asymmetries. The multi-institutional data draw attention to the often unnoticed, but vital, role that higher-education institutions play in supporting transnational research endeavors that address issues of current and future global concern. The conclusion considers wider implications for higher-education involvement in transnational knowledge generation and calls for increased symmetry in collaborative research ventures.

  18. "It Has No Color, It Has No Gender, It's Gender Bending": Gender and Sexuality Fluidity and Subversiveness in Drag Performance. (United States)

    Egner, Justine; Maloney, Patricia


    Gender identity is a key question for drag performers. Previous research has shown a lack of consensus about the subversiveness and gender fluidity of drag performers. This article examines the question: How does the relationship between performers and their audience affect the subversive nature and gender representation of drag performers in this study? Furthermore, is this relationship complicated by sexuality? This study uses ethnographic and interview methods, examining experiences of 10 drag performers. Findings indicate mutuality in the relationship between performers and audience. The recursiveness of this relationship provides a constant feedback to the performers in their effort to displace the audience's previously held notions. The performers have fluid understandings of gender and sexuality, often presenting multiple genders in and out of drag. Interactions between performers and their audience indicate their belief in gender fluidity; moreover, the drag performers themselves desire to be subversive and gender and sexually fluid.

  19. Handbook of Research on Creative Problem-Solving Skill Development in Higher Education

    DEFF Research Database (Denmark)

    -solving. This has prompted institutions of higher education to implement new pedagogical methods such as problem-based and case-based education. The Handbook of Research on Creative Problem-Solving Skill Development in Higher Education is an essential, comprehensive collection of the newest research in higher...... education, creativity, problem solving, and pedagogical design. It provides the framework for further research opportunities in these dynamic, necessary fields. Featuring work regarding problem-oriented curriculum and its applications and challenges, this book is essential for policy makers, teachers......Developing students’ creative problem-solving skills is paramount to today’s teachers, due to the exponentially growing demand for cognitive plasticity and critical thinking in the workforce. In today’s knowledge economy, workers must be able to participate in creative dialogue and complex problem...

  20. Higher education and curriculum innovation: results of an institutional network research

    Directory of Open Access Journals (Sweden)

    Martha Maria Prata-Linhares


    Full Text Available In this article we share the paths of an investigation carried out by a group of researchers from different Brazilian universities (FORPEC, which, based on the results of the investigation, built a network of information and research involving various education institutions. While describing this group’s pathway, the text presents innovating experiences of curriculums in higher education which provided important and significant pedagogic changes in their projects. During the period of investigation, 6 (six projects of university courses with innovation proposals were brought up and analyzed. This analysis allowed for the elaboration of innovation concepts for Higher Education, identify active innovating methodologies, create and implant innovative projects in Higher Education, as well as give the start off to investigation concerning the development of the docents integrating the innovating curricular projects. The groups’ pathway in itself may be considered an innovative research project.

  1. Clinical research in dermatology: resources and activities associated with a higher scientific productivity. (United States)

    Molina-Leyva, Alejandro; Descalzo, Miguel A; García-Doval, Ignacio


    Clinical research papers and their derived metrics can be useful to assess the scientific production of medical and research centers. Diverse factors are probably associated to differences in scientific production. But there are scarce studies analyzing them. Resources are limited and have to be distributed efficiently. The objective of this study is to explore what resources and activities are potentially associated with a higher scientific productivity. A bibliometric study was performed to obtain information about scientific productivity. Papers included had to meet criteria to be considered clinical research in dermatology, additionally had to be published between the years 2005-2014, had to be included in Pubmed or Embase and had to include a Spanish center of dermatology as the correspondence address. Information about research resources and activities of the year 2015 was gathered by means of an online survey sent to the authors identified in the bibliometric study. The search strategy returned 8617 papers and only 1104 of them (12.81%) met the inclusion criteria. 63 out of 113 centers responded to the survey (55.75%). Factors associated with a higher scientific productivity were: the size of the resident program, the amount of time specifically dedicated to research, a lower clinical workload, and the number of clinical trials performed in the last year. We have demonstrated that some factors are associated with a higher scientific productivity. Residency program, more research staff, clinical workload redistribution and research motivation/initiatives are key strategies that could improve scientific productivity of a center.

  2. Modelling of Aerodynamic Drag in Alpine Skiing


    Elfmark, Ola


    Most of the breaking force in the speed disciplines in alpine skiing is caused by the aerodynamic drag, and a better knowledge of the drag force is therefore desirable to gain time in races. In this study a complete database of how the drag area (CDA) changes, with respect to the different body segments, was made and used to explain a complete body motion in alpine skiing. Three experiments were performed in the wind tunnel at NTNU, Trondheim. The database from a full body measurement on an a...

  3. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek


    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  4. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev


    We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

  5. From an Analytical Framework for Understanding the Innovation Process in Higher Education to an Emerging Research Field of Innovations in Higher Education (United States)

    Cai, Yuzhuo


    While studies dealing with issues related to innovations in higher education proliferate, there has been little consensus on key concepts and central issues for research. To respond to the challenges, this paper calls for developing a new research field--studies on innovations in higher education, by integrating two disciplines, namely innovation…

  6. Modification of near-wall coherent structures in polymer drag reduced flow: simulation (United States)

    Dubief, Yves; White, Christopher; Shaqfeh, Eric; Moin, Parviz; Lele, Sanjiva


    Polymer drag reduced flows are investigated through direct numerical simulations of viscoelastic flows. The solver for the viscoelastic model (FENE-P) is based on higher-order finite difference schemes and a novel implicit time integration method. Its robustness allows the simulation of all drag reduction (DR) regimes from the onset to the maximum drag reduction (MDR). It also permits the use of realistic polymer length and concentration. The maximum polymer extension in our simulation matches that of a polystyrene molecule of 10^6 molecular weight. Two distinct regimes of polymer drag reduced flows are observed: at low drag reduction (LDR, DR< 40-50%), the near-wall structure is essentially similar to Newtonian wall turbulence whereas the high drag reduction regime (HDR, DR from 40-50% to MDR) shows significant differences in the organization of the coherent structures. The 3D information provided by numerical simulations allows the determination of the interaction of polymers and near-wall coherent structures. To isolate the contribution of polymers in the viscous sublayer, the buffer and the outer region of the flow, numerical experiments are performed where the polymer concentration is varied in the wall-normal direction. Finally a mechanism of polymer drag reduction derived from our results and PIV measurements is discussed.

  7. Grafted natural polymer as new drag reducing agent: An experimental approach

    Directory of Open Access Journals (Sweden)

    Abdulbari Hayder A.


    Full Text Available The present investigation introduces a new natural drag reducing agent which has the ability to improve the flow in pipelines carrying aqueous or hydrocarbon liquids in turbulent flow. Okra (Abelmoschus esculentus mucilage drag reduction performance was tested in water and hydrocarbon (gas-oil media after grafting. The drag reduction test was conducted in a buildup closed loop liquid circulation system consists of two pipes 0.0127 and 0.0381 m Inside Diameter (ID, four testing sections in each pipe (0.5 to 2.0 m, tank, pump and pressure transmitters. Reynolds number (Re, additive concentration and the transported media type (water and gas-oil, were the major drag reduction variables investigated. The experimental results show that, new additive drag reduction ability is high with maximum percentage of drag reduction (%Dr up to 60% was achieved. The experimental results showed that the drag reduction ability increased by increasing the additive concentration. The %Dr was found to increase by increasing the Re by using the water-soluble additive while it was found to decrease by increasing the Re when using the oil-soluble additive. The %Dr was higher in the 0.0381 m ID pipe. Finally, the grafted and natural mucilage showed high resistance to shear forces when circulated continuously for 200 seconds in the closed-loop system.

  8. Sustainability in Chinese Higher Educational Institutions’ Social Science Research: A Performance Interface toward Efficiency

    Directory of Open Access Journals (Sweden)

    Xianmei Wang


    Full Text Available Sustainability issues in higher educational institutions’ (HEIs research, especially in the social science field, have attracted increasing levels of attention in higher education administration in recent decades as HEIs are confronted with a growing pressure worldwide to increase the efficiency of their research activities under a limited volume and relatively equitable division of public funding resources. This paper introduces a theoretical analysis framework based on a data envelopment analysis, separating the social science research process into a foundation stage and a construction stage, and then projecting each HEI into certain quadrants to form several clusters according to their overall and stage efficiencies and corresponding Malmquist Productivity Indices. Furthermore, the interfaces are formed in each cluster as feasible potential improvement directions. The empirical results in detail are demonstrated from a data set of Chinese HEIs in Jiangsu Province over the Twelfth Five-Year period as offering a closer approximation to the “China social science research best practice”.

  9. Effect of truncated cone roughness element density on hydrodynamic drag (United States)

    Womack, Kristofer; Schultz, Michael; Meneveau, Charles


    An experimental study was conducted on rough-wall, turbulent boundary layer flow with roughness elements whose idealized shape model barnacles that cause hydrodynamic drag in many applications. Varying planform densities of truncated cone roughness elements were investigated. Element densities studied ranged from 10% to 79%. Detailed turbulent boundary layer velocity statistics were recorded with a two-component LDV system on a three-axis traverse. Hydrodynamic roughness length (z0) and skin-friction coefficient (Cf) were determined and compared with the estimates from existing roughness element drag prediction models including Macdonald et al. (1998) and other recent models. The roughness elements used in this work model idealized barnacles, so implications of this data set for ship powering are considered. This research was supported by the Office of Naval Research and by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

  10. The Globalisation Challenge for European Higher Education: Convergence and Diversity, Centres and Peripheries. Higher Education Research and Policy. Volume 4 (United States)

    Zgaga, Pavel, Ed.; Teichler, Ulrich, Ed.; Brennan, John, Ed.


    The last decade has marked the European higher education with a particular dynamics. Today, after a decade of a «concerted» policy, national systems look much more convergent but new questions and dilemmas are emerging: about its nature and quality, about real impact of recent reforms in different countries as well as about its future. The book…

  11. Research Trends in Mobile Learning in Higher Education: A Systematic Review of Articles (2011-2015) (United States)

    Krull, Greig; Duart, Josep M.


    The potential and use of mobile devices in higher education has been a key issue for educational research and practice since the widespread adoption of these devices. Due to the evolving nature and affordances of mobile technologies, it is an area that requires ongoing investigation. This study aims to identify emerging trends in mobile learning…

  12. The Statistical Knowledge Gap in Higher Degree by Research Students: The Supervisors' Perspective (United States)

    Baglin, James; Hart, Claire; Stow, Sarah


    This study sought to gain an understanding of the current statistical training and support needs for Australian Higher Degree by Research (HDR) students and their supervisors. The data reported herein are based on the survey responses of 191 (18.7%) eligible supervisors from a single Australian institution. The survey was composed of both…

  13. A Methodological Review of Structural Equation Modelling in Higher Education Research (United States)

    Green, Teegan


    Despite increases in the number of articles published in higher education journals using structural equation modelling (SEM), research addressing their statistical sufficiency, methodological appropriateness and quantitative rigour is sparse. In response, this article provides a census of all covariance-based SEM articles published up until 2013…

  14. Signature Concepts of Key Researchers in North American Higher Education Teaching and Learning (United States)

    Kandlbinder, Peter


    Universities in the English-speaking world share a common ancestry that extends back to medieval times. From these beginnings universities quickly developed distinctive qualities as they became integrated within different social and cultural systems of their home societies. A number of comparisons of higher education research have shown major…

  15. Writing Regulation Processes in Higher Education: A Review of Two Decades of Empirical Research (United States)

    Sala-Bubaré, Anna; Castelló, Montserrat


    In Higher Education (HE), writers need to regulate their writing processes in order to achieve their communicative goals. Although critical for academic success and knowledge construction, writing regulation processes have been mainly researched in compulsory education rather than in HE, with no systematic review focused on this context. The…

  16. CATIE: Tropical Agricultural Research and Higher Education Center. (United States)

    Applied Environmental Education and Communication, 2004


    This article features CATIE (Centro Agronomico Tropical de Investigacion y Ensenanza), a tropical agricultural research and higher education center. CATIE's mission is to be instrumental in poverty reduction and rural development in the American tropics, by promoting diversified and competitive agriculture and sustainable management of natural…

  17. Support Services for Higher Degree Research Students: A Survey of Three Australian Universities (United States)

    Silva, Pujitha; Woodman, Karen; Taji, Acram; Travelyan, James; Samani, Shamim; Sharda, Hema; Narayanaswamy, Ramesh; Lucey, Anthony; Sahama, Tony; Yarlagadda, Prasad K. D. V.


    A survey was conducted across three Australian universities to identify the types and format of support services available for higher degree research (HDR, or MA and Ph.D.) students. The services were classified with regards to availability, location and accessibility. A comparative tool was developed to help institutions categorise their services…

  18. Toward the Integration of Meditation into Higher Education: A Review of Research Evidence (United States)

    Shapiro, Shauna L.; Brown, Kirk Warren; Astin, John A.


    Context: There is growing interest in the integration of meditation in higher education. Purpose: Here, we review evidence bearing on the utility of meditation to facilitate the achievement of traditional educational goals and to enhance education of the "whole person." Research Design: We examine how meditation practices may help foster important…

  19. Translating Research into New Instructional Technologies for Higher Education: The Active Ingredient Process (United States)

    Clark, Richard E.


    This article describes a research-based approach for developing new instructional technologies for higher education. The argument is made that the most common instructional methods used by faculty and educational technology in colleges and universities are based on adult learning theories that have not been supported in the past half-century of…

  20. Profiles of Change in Motivation for Teaching in Higher Education at an American Research University (United States)

    Gunersel, Adalet B.; Kaplan, Avi; Barnett, Pamela; Etienne, Mary; Ponnock, Annette R.


    The current study employed an emergent theoretical model of teaching role identity and motivation to investigate the change in conception of and motivation for teaching in higher education of research graduate students who teach in the United States. Fifteen participants took a graduate-level seminar as part of a two-course teaching professional…

  1. Peru and its new challenge in higher education: Towards a research university. (United States)

    Lavalle, Carlos; de Nicolas, Victor Luis


    The paradigm of research universities linked to the emergence of university rankings has unified and universalized the criteria relating to the quality of higher education. This situation has led to multiple responses across global society, which has started rating the quality of higher education systems through these rankings, supported by a series of indicators aligned to the characteristics of research universities. Given that the quality of a country's higher education is one of the fundamental pillars of its development, many countries have started to take government action in this respect. In the case of Peru this has not taken long, with the approval of Law 30220 in 2014. This aims to regulate the quality of higher education through a series of specific conditions governed by a newly created body known as SUNEDU. This article uses a Delphi panel to analyze the existing relationship between the conditions imposed by SUNEDU and the research universities' intrinsic characteristics. During the Delphi panel a consensus was reached through an acceptable and stable level of responses, resulting in confirmation that there is alignment between the conditions imposed by SUNEDU and the intrinsic characteristics of research universities.

  2. Strategic Renewal and Development Implications of Organisational Effectiveness Research in Higher Education in Australia. (United States)

    Lysons, Art


    Suggests that organizational effectiveness research has made considerable progress in empirically deriving a systematic framework of theoretical and practical utility in Australian higher education. Offers a taxonomy based on the competing values framework and discusses use of inter-organizational comparisons and profiles for diagnosis in…

  3. Race without Racism: How Higher Education Researchers Minimize Racist Institutional Norms (United States)

    Harper, Shaun R.


    This article analyzes 255 articles published in seven peer-reviewed journals over a 10-year period and presents examples of how higher education researchers undertake the study of campus racial climates; racial differences in access, outcomes, and attainment; and the experiences of students, faculty, and administrators of color on predominantly…

  4. Nature of the Venus thermosphere derived from satellite drag measurements (solicited paper) (United States)

    Keating, G.; Theriot, M.; Bougher, S.


    density, scale height, inferred temperature, pressure, and other parameters as a function of altitude. The risk involved in the orbital decay and accelerometer measurements is minimal. We have not lost any spacecraft orbiting Venus or Mars due to unexpected thermospheric drag effects in over 30 years. The Venus Express accelerometer drag experiment is very similar to accelerometer experiments aboard Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter which orbit Mars. The Venus Express drag measurements of the polar region will allow a global empirical model of the thermosphere to emerge. Previous drag measurements have been made principally near the equator. The experiment may help us understand on a global scale, tides, winds, gravity waves, planetary waves, and the damping of waves. Comparisons will be made between low and high latitude results; between the middle and upper atmosphere; and with other instruments that provide information from current and previous measurements. The character of the sharp temperature gradient near the day/night terminator needs to be studied at all latitudes. The cryosphere we discovered on the nightside needs to be studied at high latitudes. The rotating vortex dipole over the North Pole surrounded by a colder "collar" needs to be analyzed to identify how wave activity extends into the polar thermosphere. We have already discovered super-rotation in the equatorial thermosphere, but we need to study 4-day super-rotation at higher latitudes to obtain a global picture of the thermosphere. The super-rotation may affect escape rates and the evolution of the atmosphere. References: [1] Keating, G. M., et al: Venus Thermosphere and Exosphere: First Satellite Drag Measurements of an Extraterrestrial Atmosphere. Science, Vol. 203, No. 4382, 772-774, Feb. 23, 1979. [2] Keating, G. M. and Bougher, S.W.: Isolation of Major Venus Cooling Mechanism and Implications for Earth and Mars, Journal of Geophysical Research, Vol. 97, 4189

  5. Microblowing Technique for Drag Reduction, Phase I (United States)

    National Aeronautics and Space Administration — NASA seeks to develop technologies for aircraft drag reduction which contribute to improved aerodynamic efficiency in support of national goals for reducing fuel...

  6. The physics of orographic gravity wave drag

    Directory of Open Access Journals (Sweden)

    Miguel A C Teixeira


    Full Text Available The drag and momentum fluxes produced by gravity waves generated in flow over orography are reviewed, focusing on adiabatic conditions without phase transitions or radiation effects, and steady mean incoming flow. The orographic gravity wave drag is first introduced in its simplest possible form, for inviscid, linearized, non-rotating flow with the Boussinesq and hydrostatic approximations, and constant wind and static stability. Subsequently, the contributions made by previous authors (primarily using theory and numerical simulations to elucidate how the drag is affected by additional physical processes are surveyed. These include the effect of orography anisotropy, vertical wind shear, total and partial critical levels, vertical wave reflection and resonance, non-hydrostatic effects and trapped lee waves, rotation and nonlinearity. Frictional and boundary layer effects are also briefly mentioned. A better understanding of all of these aspects is important for guiding the improvement of drag parametrization schemes.

  7. Satellite Formation Control Using Atmospheric Drag

    National Research Council Canada - National Science Library

    Hajovsky, Blake B


    This study investigates the use of a linear quadratic terminal controller to reconfigure satellite formations using atmospheric drag actuated control while minimizing the loss of energy of the formation...

  8. Active aerodynamic drag reduction on morphable cylinders (United States)

    Guttag, M.; Reis, P. M.


    We study a mechanism for active aerodynamic drag reduction on morphable grooved cylinders, whose topography can be modified pneumatically. Our design is inspired by the morphology of the Saguaro cactus (Carnegiea gigantea), which possesses an array of axial grooves, thought to help reduce aerodynamic drag, thereby enhancing the structural robustness of the plant under wind loading. Our analog experimental samples comprise a spoked rigid skeleton with axial cavities, covered by a stretched elastomeric film. Decreasing the inner pressure of the sample produces axial grooves, whose depth can be accurately varied, on demand. First, we characterize the relation between groove depth and pneumatic loading through a combination of precision mechanical experiments and finite element simulations. Second, wind tunnel tests are used to measure the aerodynamic drag coefficient (as a function of Reynolds number) of the grooved samples, with different levels of periodicity and groove depths. We focus specifically on the drag crisis and systematically measure the associated minimum drag coefficient and the critical Reynolds number at which it occurs. The results are in agreement with the classic literature of rough cylinders, albeit with an unprecedented level of precision and resolution in varying topography using a single sample. Finally, we leverage the morphable nature of our system to dynamically reduce drag for varying aerodynamic loading conditions. We demonstrate that actively controlling the groove depth yields a drag coefficient that decreases monotonically with Reynolds number and is significantly lower than the fixed sample counterparts. These findings open the possibility for the drag reduction of grooved cylinders to be operated over a wide range of flow conditions.

  9. Research Culture in Higher Education: The Case of a Foreign Language Department in Mexico

    Directory of Open Access Journals (Sweden)

    Edith Hernández Méndez


    Full Text Available In the case of Mexico, until recently, many universities focused mainly on teaching, but recent changes have led to new appointments in research, administration, and community service. There now seems to be, however, a view of the predominance of research in the academic environment. Therefore, the purpose of this paper was to examine and identify, through the lens of organizational theory and a current model of research culture in an academic setting, some characteristics of the research culture in the Department of Languages and Education at a public university in Southeast Mexico. Following the international tendencies and models in higher education, we see that the research culture observed in this university resembles more a market culture than other types of culture, although some traits of hierarchy culture provide cohesion in the organization.

  10. Bioinspired surfaces for turbulent drag reduction. (United States)

    Golovin, Kevin B; Gose, James W; Perlin, Marc; Ceccio, Steven L; Tuteja, Anish


    In this review, we discuss how superhydrophobic surfaces (SHSs) can provide friction drag reduction in turbulent flow. Whereas biomimetic SHSs are known to reduce drag in laminar flow, turbulence adds many new challenges. We first provide an overview on designing SHSs, and how these surfaces can cause slip in the laminar regime. We then discuss recent studies evaluating drag on SHSs in turbulent flow, both computationally and experimentally. The effects of streamwise and spanwise slip for canonical, structured surfaces are well characterized by direct numerical simulations, and several experimental studies have validated these results. However, the complex and hierarchical textures of scalable SHSs that can be applied over large areas generate additional complications. Many studies on such surfaces have measured no drag reduction, or even a drag increase in turbulent flow. We discuss how surface wettability, roughness effects and some newly found scaling laws can help explain these varied results. Overall, we discuss how, to effectively reduce drag in turbulent flow, an SHS should have: preferentially streamwise-aligned features to enhance favourable slip, a capillary resistance of the order of megapascals, and a roughness no larger than 0.5, when non-dimensionalized by the viscous length scale.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  11. Measurement of drag and its cancellation

    Energy Technology Data Exchange (ETDEWEB)

    DeBra, D B; Conklin, J W, E-mail: [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305-4035 (United States)


    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  12. Measurement of drag and its cancellation

    International Nuclear Information System (INIS)

    DeBra, D B; Conklin, J W


    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  13. From research excellence to brand relevance: A model for higher education reputation building

    Directory of Open Access Journals (Sweden)

    Nina Overton-de Klerk


    Full Text Available In this article we propose a novel approach to reputation development at higher education institutions. Global reputation development at higher education institutions is largely driven by research excellence, is predominantly measured by research output, and is predominantly reflected in hierarchical university rankings. The ranking becomes equated with brand equity. We argue that the current approach to reputation development in higher education institutions is modernist and linear. This is strangely out-of-kilter with the complexities of a transforming society in flux, the demands of a diversity of stakeholders, and the drive towards transdisciplinarity, laterality, reflexivity and relevance in science. Good research clearly remains an important ingredient of a university's brand value. However, a case can be made for brand relevance, co-created in collaboration with stakeholders, as an alternative and non-linear way of differentiation. This approach is appropriate in light of challenges in strategic science globally as well as trends and shifts in the emerging paradigm of strategic communication. In applying strategic communication principles to current trends and issues in strategic science and the communication thereof, an alternative model for strategic reputation building at higher education institutions is developed.

  14. Control of Nonlinear Coupled Electromagnetic Actuators for Active Drag Reduction in Turbulent Flow


    Seidler, Florian; Trabert, Julius; Dück, Marcel; van Waasen, Stefan; Schiek, Michael; Abel, Dirk; Castelan, E. B.


    The research group FOR1779 “active drag reduction via wavy surface oscillations” develops robust methods for reduction of turbulent friction drag by flow control. The planned concentration on unsteady flow conditions requires a control of the electromagnetic actuator system for generation of transversal surface waves. The bars are positioned in parallel and coupled with an aluminum surface to generate a travelling wave perpendicular to the flow field. The actuator system can be approximately ...

  15. Equality adds quality: On upgrading higher education and research in the field of law

    Directory of Open Access Journals (Sweden)

    Baer Susanne


    Full Text Available Much has been attempted, and many projects are still underway aimed at achieving equality in higher education and research. Today, the key argument to demand and support the integration of gender in academia is that equality is indeed about the quality on which academic work is supposed to be based. Although more or less national political, social and cultural contexts matter as much as academic environments, regarding higher education and research, the integration of gender into the field of law seems particularly interesting. Faculties of law enjoy a certain standing and status, are closely connected to power and politics, and are likely to feature resistance to equality efforts, both in the law itself and in the curriculum and research agenda. However, a multidimensional, intersectional gender analysis helps to reframe cases and doctrines, rulings and regulations far beyond the law that evidently affects women, which the headscarf controversies illustrate. In addition to gender competence, team diversity is a procedural device for success, and non-discrimination is a key requirement when diversity is meant to work. After all, such efforts - to expose bias and educate about gender in an academic field, to insist and integrate it continuously, and to not only demand but also do it - produce quality. Thus, gender equality is crucial for the achievement of the best possible results in higher education and research.

  16. 5th Drag Reduction in Engineering Flows Meeting

    CERN Document Server


    The European Drag Reduction Meeting has been held on 15th and 16th November 1990 in London. This was the fifth of the annual European meetings on drag reduction in engineering flows. The main objective of this meeting was to discuss up-to-date results of drag reduction research carried out in Europe. The organiser has adopted the philosophy of discussing the yesterday's results rather than the last year's results. No written material has therefore been requested for the meeting. It was only after the meeting the submission of papers was requested to the participants, from which 16 papers were selected for this proceedings volume. The meeting has attracted a record number of participants with a total of 52 researchers from seven European countries, U. K. , France, Germany, the Netherlands, Italy, Switzerland and U. S. S. R. as well as from Japan, Canada and Australia. The subjects covered in this proceedings volume include riblets, LEBUs (Large Eddy Break-Up device), surface roughness, compliant surfaces and p...


    Directory of Open Access Journals (Sweden)

    Chris INMAN


    Full Text Available This study reviewed empirical research conducted in Second Life by educators since Second Life’s launch in 2003. The study’s purpose was to identify how Second Life is being used in both K-12 and higher education. The methodology, findings, and recommendations of 27 research studies were analyzed. Researchers identified potential problems when using Second Life in education, including issues with the Second Life software and hardware requirements, a steep learning curve, and the possibility of students becoming exposed to distractions or inappropriate content. Researchers discussed potential uses of Second Life including role-play, game and simulation creation, implementation within distance education programs, and the ability to encourage student-centered learning activities. Analysis also revealed several recommendations for educators intending to use Second Life.

  18. Preparation of Nano-Scale Biopolymer Extracted from Coconut Residue and Its Performance as Drag Reducing Agent (DRA

    Directory of Open Access Journals (Sweden)

    Hasan Muhammad Luqman Bin


    Full Text Available Drag or frictional force is defined as force that acts opposite to the object’s relative motion through a fluid which then will cause frictional pressure loss in the pipeline. Drag Reducing Agent (DRA is used to solve this issue and most of the DRAs are synthetic polymers but has some environmental issues. Therefore for this study, biopolymer known as Coconut Residue (CR is selected as the candidate to replace synthetic polymers DRA. The objective of this study is to evaluate the effectiveness of Nano-scale biopolymer DRA on the application of water injection system. Carboxymethyl cellulose (CMC is extracted by synthesizing the cellulose extracted from CR under the alkali-catalyzed reaction using monochloroacetic acid. The synthesize process is held in controlled condition whereby the concentration of NaOH is kept at 60%wt, 60 °C temperature and the reaction time is 4 hours. For every 25 g of dried CR used, the mass of synthesized CMC yield is at an average of 23.8 g. The synthesized CMC is then grinded in controlled parameters using the ball milling machine to get the Nano-scale size. The particle size obtained from this is 43.32 Nm which is in range of Nano size. This study proved that Nano-size CMC has higher percentage of drag reduction (%DR and flow increase (%FI if compared to normal-size CMC when tested in high and low flow rate; 44% to 48% increase in %DR and %FI when tested in low flow rate, and 16% to 18% increase in %DR and %FI when tested in high flow rate. The success of this research shows that Nano-scale DRA can be considered to be used to have better performance in reducing drag.

  19. Influence of Blocker Distance Variations in form of Triangle in Front of Cylinder toward Drag Coefficien

    Directory of Open Access Journals (Sweden)

    Si Putu Gede Gunawan Tista


    Full Text Available One of the ways to reduce energy consumption on the air plane and the other bluff bodies are by decreasing the drag. Drag isclosely related to the flow separation. The earlier separation, then the drag will increase more. Based of the fact the effort todecrease drag is conducted by manipulating the field of fluid flow. Stream manipulation was be done by installing Triangleobstacle in front of cylinder. The purpose of this research is to analyze the effect of various distance triangle obstacle in front ofcylinder on drag. The present experiment was done by placing triangle rod in front of the cylinder. In the present research, theexperiment was conducted in the wind tunnel, which consisted of blower, pitot pipe, manometer, cylinder pipe, and triangle rod.The triangle was positioned at L/D = 1.19, L/D = 1.43, L/D = 1.67, L/D = 1.9, L/D = 2.14, L/D = 2.38, L/D = 2.62, and L/D =2.86 by upstream from the cylinder. The triangle was 8 mm uniform side. The Reynolds number based on the cylinder diameter (D= 42 mm was Re = 1.81 x 104. The research results showed that the triangle rod could decrease the drag of cylinder. Coefficientdrag for cylinder without triangle rod was 0.1276 while the biggest decrease of coefficient of drag with triangle rod washappened at L/D = 1.43 which was 0.0188. It means that the drag of cylinder with triangle rod was 85.25% lower than thecylinder alone.

  20. Airfoil Drag Reduction using Controlled Trapped Vorticity Concentrations (United States)

    Desalvo, Michael; Glezer, Ari


    The aerodynamic performance of a lifting surface at low angles of attack (when the base flow is fully attached) is improved through fluidic modification of its ``apparent'' shape by superposition of near-surface trapped vorticity concentrations. In the present wind tunnel investigations, a controlled trapped vorticity concentration is formed on the pressure surface of an airfoil (NACA 4415) using a hybrid actuator comprising a passive obstruction of scale O(0.01c) and an integral synthetic jet actuator. The jet actuation frequency [Stact O(10)] is selected to be at least an order of magnitude higher than the characteristic unstable frequency of the airfoil wake, thereby decoupling the actuation from the global instabilities of the base flow. Regulation of vorticity accumulation in the vicinity of the actuator by the jet effects changes in the local pressure, leading in turn to changes in the airfoil's drag and lift. Trapped vorticity can lead to a significant reduction in drag and reduced lift (owing to the sense of the vorticity), e.g. at α =4° and Re = 6.7 .105 the drag and lift reductions are 14% and 2%, respectively. PIV measurements show the spatial variation in the distribution of vorticity concentrations and yield estimates of the corresponding changes in circulation.

  1. SURFdrive, a sync and share service for Dutch higher education and research

    CERN Multimedia

    CERN. Geneva


    During the first three months of this year we have setup an Owncloud-based sync and share service for Dutch higher education and research. This service uses a SAML2-based federated login. In this presentation we will discuss the requirements, choices we have made, tests we have done, the technical setup and the experiences we have had so far not only with the software and our setup but also setting up this service.

  2. Intellectual Leadership of Researchers in Higher Education: Relationship Between the Demographic Factors and Roles (Lithuanian Context)


    Žydžiūnaitė Vilma


    The intellectual leadership of educators or teachers represents a topic of a great interest for educational research and practice. Variety of variables or factors have been examined to find the most complete explanations for teachers’, professors’ and educators’ roles, for example, institutional, financial, gender, organizational, spiritual, and intellectual. No literature was found on the relationship between the demographic variables and researchers’ roles in higher education regarding inte...

  3. Communique Declaration: The New Dynamics of Higher Education and Research for Societal Change and Development (2nd UNESCO Higher Education Assembly July, 2009) (United States)

    Adult Learning, 2012


    This article presents the communique declaration on the new dynamics of higher education and research for societal change and development. This declaration begins with a preamble and focuses on (1) social responsibility of higher education; (2) access, equity and quality; (3) internationalisation, regionalisation and globalisation; (4) learning…

  4. Thermal lift generation and drag reduction in rarefied aerodynamics (United States)

    Pekardan, Cem; Alexeenko, Alina


    With the advent of the new technologies in low pressure environments such as Hyperloop and helicopters designed for Martian applications, understanding the aerodynamic behavior of airfoils in rarefied environments are becoming more crucial. In this paper, verification of rarefied ES-BGK solver and ideas such as prediction of the thermally induced lift and drag reduction in rarefied aerodynamics are investigated. Validation of the rarefied ES-BGK solver with Runge-Kutta discontinous Galerkin method with experiments in transonic regime with a Reynolds number of 73 showed that ES-BGK solver is the most suitable solver in near slip transonic regime. For the quantification of lift generation, A NACA 0012 airfoil is studied with a high temperature surface on the bottom for the lift creation for different Knudsen numbers. It was seen that for lower velocities, continuum solver under predicts the lift generation when the Knudsen number is 0.00129 due to local velocity gradients reaching slip regime although lift coefficient is higher with the Boltzmann ES-BGK solutions. In the second part, the feasibility of using thermal transpiration for drag reduction is studied. Initial study in drag reduction includes an application of a thermal gradient at the upper surface of a NACA 0012 airfoil near trailing edge at a 12-degree angle of attack and 5 Pa pressure. It was seen that drag is reduced by 4 percent and vortex shedding frequency is reduced due to asymmetry introduced in the flow due to temperature gradient causing reverse flow due to thermal transpiration phenomena.

  5. Effect of lift-to-drag ratio in pilot rating of the HL-20 landing task (United States)

    Jackson, E. B.; Rivers, Robert A.; Bailey, Melvin L.


    A man-in-the-loop simulation study of the handling qualities of the HL-20 lifting-body vehicle was made in a fixed-base simulation cockpit at NASA Langley Research Center. The purpose of the study was to identify and substantiate opportunities for improving the original design of the vehicle from a handling qualities and landing performance perspective. Using preliminary wind-tunnel data, a subsonic aerodynamic model of the HL-20 was developed. This model was adequate to simulate the last 75-90 s of the approach and landing. A simple flight-control system was designed and implemented. Using this aerodynamic model as a baseline, visual approaches and landings were made at several vehicle lift-to-drag ratios. Pilots rated the handling characteristics of each configuration using a conventional numerical pilot-rating scale. Results from the study showed a high degree of correlation between the lift-to-drag ratio and pilot rating. Level 1 pilot ratings were obtained when the L/D ratio was approximately 3.8 or higher.

  6. Role of Elasto-Inertial Turbulence in Polymer Drag Reduction (United States)

    Dubief, Yves; Sid, Samir; Terrapon, Vincent


    Elasto-Inertial Turbulence (EIT) is a peculiar state of turbulence found in dilute polymer solutions flowing in parallel wall flows over a wide range of Reynolds numbers. At subcritical Reynolds numbers, appropriate boundary conditions trigger EIT, a self-sustaining cycle of energy transfers between thin sheets of stretched polymers and velocity perturbations, which translates into an increase of friction drag. For critical and supercritical Reynolds numbers, polymer additives may lead to significant drag reduction, bounded by the asymptotic state known as Maximum Drag Reduction (MDR). The present research investigates the role of EIT in the dynamics of critical and supercritical Reynolds number wall flows. Using high-fidelity direct numerical simulations of channel flows and the FENE-P model, we establish that (i) EIT is two-dimensional, (ii) the scales essential to the existence of EIT are sub-Kolmogorov, and (iii) EIT drives MDR at low and possibly moderate Reynolds number turbulent flows. These findings were validated in two different codes and using unprecedented resolutions for polymer flows. YD is grateful for the support of Binational Science Foundation. SS and VT acknowledges Fonds de la Recherche Scientifique (FNRS), MarieCurie Career Integration Grant and computing allocation from University of Liege and PRACE.

  7. Pengaruh Variasi Jarak Penghalang Segitiga di depan Silinder Arah Vertikal terhadap Drag

    Directory of Open Access Journals (Sweden)

    I Putu Gede Gunawan Tista


    manipulating the field of fluid flow. The stream manipulation can be done passively, for example, by attaching a fin at the bluff body, by making a hole on the bluff body, enhancing spiral at the bluff body and placing a smaller barrier, on front of bluff body. The experiment was done by placing a triangle rod on front of the cylinder. In the present research the experiment was conducted in a wind tunnel, which consisted of a blower, a pitot pipe, a manometer, a main cylinder pipe, and a triangle rod. The triangle was variation vertical positioned at y = 0 mm, y = 5 mm, y = 10 mm, y = 15 mm. while the position of barrier in the horizontal direction at 60 mm distance towards the cylinder with the triangle side length was 8 mm. Pressure distribution was measured on 36 points at the cylinder surface with an interval of 100. The measured data was the pressure of cylinder surface, the static pressure, and the airflow speed.The research results showed that the triangle rod could decrease the drag of the main cylinder. The Coefficient drag for the cylinder without the triangle rod was 0, 1276 while the variation of barrier in the vertical direction obtained the biggest decrease of the coefficient of the drag with the triangle rod happened at position y = 0, which was 0, 0186. The magnitude of the drag reduction in this position was 85, 45% compared without barrier.

  8. Geodetic precession or dragging of inertial frames?

    International Nuclear Information System (INIS)

    Ashby, N.; Shahid-Saless, B.


    In metric theories of gravity the principle of general covariance allows one to describe phenomena by means of any convenient choice of coordinate system. In this paper it is shown that in an appropriately chosen coordinate system, geodetic precession of a gyroscope orbiting a spherically symmetric, spinning mass can be recast as a Lense-Thirring frame-dragging effect without invoking spatial curvature. The origin of this reference frame moves around the source but the frame axes point in fixed directions. The drag can be interpreted to arise from the orbital angular momentum of the source around the origin of the reference frame. In this reference frame the effects of geodetic precession and Lense-Thirring drag due to intrinsic angular momentum of the source have the same origin, namely, gravitomagnetism

  9. Research on multiple intelligences theory and its enlightenment to higher education

    Directory of Open Access Journals (Sweden)

    Haijun Wang


    Full Text Available The theory of multiple intelligences, which has been successfully used in the education and teaching reform in the west, has been brought forward for many years. Many researches have been done and some achievements are attained in our country at the end of the twentieth century, but it is different from theoretical discussion when it was in practical use. The current higher education system plays a great constraining role, which represents control phenomenon among the talent training and the evaluation system of teachers. It is extreme necessary to explore the feasible education reformation route, regarding the multiple intelligence theory as the basic guiding ideology. Confirming the training objectives of colleges and universities, providing students with practice opportunities, and focusing on the development of individual superior intelligence will be used as a reference for the reform and development of higher education.

  10. A review of higher education image and reputation literature: Knowledge gaps and a research agenda

    Directory of Open Access Journals (Sweden)

    Amaia Lafuente-Ruiz-de-Sabando


    Full Text Available Higher education institutions are investing increasing resources in order to achieve favourable perceptions among their stakeholders. However, image and reputation management is a complex issue and how stakeholders perceive universities does not always coincide with the image the latter wish to project. For this reason, in this article we address a review of the literature on higher education image and reputation to identify the main knowledge gaps and establish the research lines that merit deeper examination in the future. The gaps identified highlight the need to improve knowledge about the way perceptions (image and reputation of university institutions are shaped, pinpointing the dimensions or essential aspects that influence their formation and determining whether their degree of influence differs when considering the perspectives of different stakeholders or individuals from different geographical areas. Theoretical propositions related to the identified gaps have been set out.

  11. NDA generic research programme for higher activity waste management issues - 16390

    International Nuclear Information System (INIS)

    McKinney, James; Brownridge, Melanie


    NDA has a responsibility to ensure decommissioning activities are sufficiently technically underpinned and appropriate Research and Development (Rand D) is carried out. The NDA funds research and development (R and D) indirectly via the Site Licence Companies (SLCs) or directly. The main component of directly funded R and D is the NDA Direct Research Portfolio (DRP). The DRP is split into four framework areas: - University Interactions; - Waste Processing; - Material Characterisation; - Actinide and Strategic Nuclear Materials. These four framework areas were competed through an Official Journal of European Union (OJEU) process in 2008. Although all four areas involve waste management, Waste Processing and Material Characterisation specifically deal with Higher Activity Waste (HAW) waste management issues. The Waste Processing area was awarded to three groups: (i) National Nuclear Laboratory (NNL), (ii) Consortium led by Hyder Consulting Ltd, and (iii) Consortium led by UKAEA Ltd. The Material Characterisation area was awarded to three groups: (i) NNL, (ii) Serco, and (iii) Consortium led by UKAEA Ltd. The initial work in Waste Processing and Material Characterisation was centered on establishing a forward research programme to address the generic needs of the UK civil nuclear industry and the NDA strategic drivers for waste management and land quality. This has been achieved by the four main framework contractors from the Waste Processing and Materials Characterisation areas working together with the NDA to identify the key research themes and begin the development of the NDA's HAW Management Research Programme. The process also involves active engagement with both industry and regulators via the Nuclear Waste Research Forum (NWRF). The NDA's HAW Management Research Programme includes a number of themes: - Optimisation of Interim Store Operation and Design; - Alternative Waste Encapsulants; - Waste Package Integrity; - Alternative Waste treatment methods

  12. Frictional Coulomb drag in strong magnetic fields

    DEFF Research Database (Denmark)

    Bønsager, Martin Christian; Flensberg, Karsten; Hu, Ben Yu-Kuang


    A treatment of frictional Coulomb drag between two two-dimensional electron layers in a strong perpendicular magnetic field, within the independent electron picture, is presented. Assuming fully resolved Landau levels, the linear response theory expression for the transresistivity rho(21) is eval......A treatment of frictional Coulomb drag between two two-dimensional electron layers in a strong perpendicular magnetic field, within the independent electron picture, is presented. Assuming fully resolved Landau levels, the linear response theory expression for the transresistivity rho(21...

  13. Evaluation of WRF Simulations With Different Selections of Subgrid Orographic Drag Over the Tibetan Plateau (United States)

    Zhou, X.; Beljaars, A.; Wang, Y.; Huang, B.; Lin, C.; Chen, Y.; Wu, H.


    Weather Research and Forecasting (WRF) simulations with different selections of subgrid orographic drag over the Tibetan Plateau have been evaluated with observation and ERA-Interim reanalysis. Results show that the subgrid orographic drag schemes, especially the turbulent orographic form drag (TOFD) scheme, efficiently reduce the 10 m wind speed bias and RMS error with respect to station measurements. With the combination of gravity wave, flow blocking and TOFD schemes, wind speed is simulated more realistically than with the individual schemes only. Improvements are also seen in the 2 m air temperature and surface pressure. The gravity wave drag, flow blocking drag, and TOFD schemes combined have the smallest station mean bias (-2.05°C in 2 m air temperature and 1.27 hPa in surface pressure) and RMS error (3.59°C in 2 m air temperature and 2.37 hPa in surface pressure). Meanwhile, the TOFD scheme contributes more to the improvements than the gravity wave drag and flow blocking schemes. The improvements are more pronounced at low levels of the atmosphere than at high levels due to the stronger drag enhancement on the low-level flow. The reduced near-surface cold bias and high-pressure bias over the Tibetan Plateau are the result of changes in the low-level wind components associated with the geostrophic balance. The enhanced drag directly leads to weakened westerlies but also enhances the a-geostrophic flow in this case reducing (enhancing) the northerlies (southerlies), which bring more warm air across the Himalaya Mountain ranges from South Asia (bring less cold air from the north) to the interior Tibetan Plateau.

  14. Higher Education Research as a Field of Study in South Korea: Inward but Starting to Look Outward (United States)

    Jung, Jisun


    This study aims to explore the development of higher education research in South Korea based on historical and scientometric perspectives. After the evolution of the country's higher education research community is presented, articles focusing on higher education from 1995 to 2012 are analysed. In total, 145 articles in international journals and…

  15. A biomechanical comparison in the lower limb and lumbar spine between a hit and drag flick in field hockey. (United States)

    Ng, Leo; Rosalie, Simon M; Sherry, Dorianne; Loh, Wei Bing; Sjurseth, Andreas M; Iyengar, Shrikant; Wild, Catherine Y


    Research has revealed that field hockey drag flickers have greater odds of hip and lumbar injuries compared to non-drag flickers (DF). This study aimed to compare the biomechanics of a field hockey hit and a specialised field hockey drag flick. Eighteen male and seven female specialised hockey DF performed a hit and a drag flick in a motion analysis laboratory with an 18-camera three-dimensional motion analysis system and a calibrated multichannel force platform to examine differences in lower limb and lumbar kinematics and kinetics. Results revealed that drag flicks were performed with more of a forward lunge on the left lower limb resulting in significantly greater left ankle dorsiflexion, knee, hip and lumbar flexion (Pshit. Drag flicks were also performed with significantly greater lateral flexion (P hit. Differences in kinematics lead to greater shear, compression and tensile forces in multiple left lower limb and lumbar joints in the drag flick compared to the hit (P hit may have ramifications with respect to injury in field hockey drag flickers.

  16. Pengaruh variasi lebar alur berbentuk segi empat pada permukaan silinder terhadap koefisien drag

    Directory of Open Access Journals (Sweden)

    Si Putu Gede Gunawan Tista


    aspects of human life, for example, fluid flow across a cylinder. In many engineering applications using cylindrical found equipment such as a chimney, a pillar of the bridge, and so on. The equipment is undergoing a puff of air at all times so that the strength of the construction has decreased, this is due to drag him in the direction of flow. Efforts are being made to reduce drag is by manipulating the flow field. Manipulation of the flow field is done by making rectangular-shaped grooves on the surface of the cylinder. The purpose of this study was to analyze the influence of variations in width rectangular-shaped grooves on the surface of the cylinder to the coefficient of drag. This research was conducted in wind tunnel consisting of a blower, pitot pipe, inclined manometer, U manometer, digital scales, and cylinders. The test object in the form of a cylinder diameter of 60 mm and a length of 420 mm is placed vertically in the wind tunnel. The width of the grooves on the surface of the cylinder varied which is 3 mm, 4 mm and 5 mm. The pressure distribution is obtained by measuring the surface pressure cylinders at 36 points with 10o intervals. Drag force testing done using digital scale that records the amount of mass, to get the drag force multiplied by gravity. The results showed a decline in the coefficient of drag on a grooved cylinder compared without grooves. Lowest coefficient values occurred in the magnitude of 4 mm groove width CD = 0.3734. The amount of reduction in drag is 22.3% compared without grooves. Keywords: drag reduction, the width of the groove, rectangular groove, cylindrical

  17. Solar and Drag Sail Propulsion: From Theory to Mission Implementation (United States)

    Johnson, Les; Alhorn, Dean; Boudreaux, Mark; Casas, Joe; Stetson, Doug; Young, Roy


    Solar and drag sail technology is entering the mainstream for space propulsion applications within NASA and around the world. Solar sails derive propulsion by reflecting sunlight from a large, mirror- like sail made of a lightweight, reflective material. The continuous sunlight pressure provides efficient primary propulsion, without the expenditure of propellant or any other consumable, allowing for very high V maneuvers and long-duration deep space exploration. Drag sails increase the aerodynamic drag on Low Earth Orbit (LEO) spacecraft, providing a lightweight and relatively inexpensive approach for end-of-life deorbit and reentry. Since NASA began investing in the technology in the late 1990's, significant progress has been made toward their demonstration and implementation in space. NASA's Marshall Space Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the interim, NASA MSFC funded the NanoSail-D, a subscale drag sail system designed for small spacecraft applications. The NanoSail-D flew aboard the Fast Affordable Science and Technology SATellite (FASTSAT) in 2010, also developed by MSFC

  18. Challenges for EURATOM research and training in the frame of the European 'Higher Education' And 'Research' areas

    International Nuclear Information System (INIS)

    Goethem, G. Van


    The paper is intended to answer two major questions of the modern society: 1) What are the challenges for EURATOM Research and Training in the frame of the European 'Higher Education' and 'Research' areas? (main stakeholders); 2) What kind of response is offered by the EURATOM RD and DD and E and T programmes in nuclear fission and radiation protection? (scientific and societal impact). The actions of the research policy in the EU are not conducted for the sake of acquiring Knowledge as a goal per se, but as a support to other EU policies, in particular, the Energy policy. In the area of fission and radiation protection, this Community policy implies the co-operation of all stakeholders (most of them participate in the EURATOM programmes), that is: research organisations (public and private, power and medical applications, etc); systems suppliers (e.g. nuclear vendors, engineering companies, etc); energy providers (e.g. electric utilities, heat and/or hydrogen vendors, etc); nuclear regulatory bodies and associated technical safety organizations (TSO); education and training (E and T) institutions, and, in particular, universities; civil society and the international institutional framework (IAEA and OECD/NEA). The emphasis in the paper is on the improvements all along the history of nuclear fission power (Generations I, II and III) as well as on the visionary innovation proposed by the 'Generation IV International Forum' (GIF). International research (in particular, EURATOM), in this area is guided by the four 'GIF Technology Goals for industry and society', namely: sustainability: e.g. enhanced fuel utilisation and optimal waste management; economics: e.g. minimisation of costs of MWe installed and MWh generated; safety and reliability: e.g. robust safety architecture, no need for off-site measures; proliferation resistance and physical protection: e.g. absence of separated Pu. EURATOM research and training is presented in the broader context of the new EU policy

  19. Hochschule und Geschlecht – aktuelle Forschungsperspektiven Higher Education and Gender—Current Research Perspectives

    Directory of Open Access Journals (Sweden)

    Cord Arendes


    Full Text Available Sowohl einzelne Universitäten als auch die Institution Universität als gesamteuropäischer Typus können heute auf eine bis weit in das Mittelalter zurückreichende Kontinuität verweisen. Die Universitäten stellen aber nicht einen geschlechtsneutralen Forschungsgegenstand, sondern eine in vielerlei Hinsicht „gendered organization“ dar. Der Sammelband präsentiert verschiedene Blickwinkel auf diese Geschlechterdimension. Um ‚Gender‘ als Erkenntniskategorie im Verhältnis zur sozialen Organisation Hochschule und zur Geschlechterkultur untersuchen zu können, ist nicht nur eine verbesserte gegenseitige Beachtung von Hochschul- sowie Frauen- und Geschlechterforschung notwendig. Entscheidende Bedeutung kommt insbesondere der reflexiven Wahrnehmung der eigenen „Betroffenheit“ der Hochschul- und der Geschlechterforscher/-innen zu.Many individual universities as well as the specifically European institution of the university can point to a continuity that reaches back well into the Middle Ages. However, universities present not a gender-neutral object of study, but instead in many respects represent a “gendered organization.” The collected volume provides different views on this gendered dimension. In order to study ‘gender’ as a category of knowledge in relation to the social organization of higher education and to gender culture it is necessary that there exist a better mutual respect between research on higher education and research on women and gender studies. Especially the reflexive perception of the way in which the university and gender researchers are themselves affected is accorded crucial meaning.




    Azerbaijan is a modern, rapidly developing democratic country at the crossroads of Europe and Asia. The country is currently harmonizing its national legislation with international norms, and reforming its national scientific and medical. Higher standards of medical research and education will enhance public health and protect human rights to life and health that are specified in Azerbaijan Constitution. In order to raise its medical research and education to international standards, Azerbaijani scientists and authorities are studying the experience of other countries and taking measures to implement international standards and norms in the country’s national legislation. Cooperation with the WHO, UNESCO and other international and foreign organizations, both on regional and global level is creating steps to achieve this goal. These steps include, for example, creation of the Azerbaijan unit of the UNESCO Chair in Bioethics and teaching bioethics based on UNESCO’s Bioethics Core Curriculum. Another step is providing research fellowship for young Azerbaijani professionals to study at leading medical research and educational centers around the world including Harvard Medical School and Boston Children’s Hospital in the USA, and Koc University in Turkey. A complementary step is the development of local bioethical research, including its legal, ethical and scientific foundations. Adherence to ethical principles in different spheres of life is currently one of the most challenging social and professional issues, especially, this is true with the development of new medical technologies in recent decades and the development of new ethical and legal standards, issues involving different areas of health and medicine and their relation to human rights. Bioethics in Azerbaijan is developing as an important field that deals with universal moral principles within the context of both national laws and the UNESCO Universal Declaration on Bioethics and Human Rights. PMID

  1. Magnetic Viscous Drag for Friction Labs (United States)

    Gaffney, Chris; Catching, Adam


    The typical friction lab performed in introductory mechanics courses is usually not the favorite of either the student or the instructor. The measurements are not all that easy to make, and reproducibility is usually a troublesome issue. This paper describes the augmentation of such a friction lab with a study of the viscous drag on a magnet…

  2. High accuracy satellite drag model (HASDM) (United States)

    Storz, Mark F.; Bowman, Bruce R.; Branson, Major James I.; Casali, Stephen J.; Tobiska, W. Kent

    The dominant error source in force models used to predict low-perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying global density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal and semidiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index ap, to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low-perigee satellites.

  3. Judicial civil procedure dragging out in Kosovo

    Directory of Open Access Journals (Sweden)

    Rrustem Qehaja


    Full Text Available This article tends to deal with one of the most worrying issues in the judicial system of Kosovo the problem of judicial civil procedure dragging out. The article analyses the reasons of these dragging outs of the judicial civil procedure focusing on the context of one of the basic procedural principles in civil procedure-the principle of economy or efficiency in the courts. Dragging out of civil procedure in Kosovo has put in question not only the basic principles of civil procedure, but it also challenges the general principles related to human rights and freedoms sanctioned not only by the highest legal act of the country, but also with international treaties. The article tends to give a reflection to the most important reasons that effect and influence in these dragging outs of civil procedure, as well as, at the same time aims to give the necessary alternatives to pass through them by identifying dilemmas within the judicial practice. As a result, the motives of this scientific paper are exactly focused at the same time on identifying the dilemmas, as well as presenting ideas, to overstep them, including the judicial practice of the European Court of Human Rights on Article 6 of the European Convention on Human Rights, by which it is given the possibility to offering people efficient and within a reasonable time legal protection of their rights before national courts. For these reasons, the paper elaborates this issue based on both, the legal theory and judicial practice.

  4. Measurements of drag and flow over biofilm (United States)

    Hartenberger, Joel; Gose, James W.; Perlin, Marc; Ceccio, Steven L.


    Microbial `slime' biofilms detrimentally affect the performance of every day systems from medical devices to large ocean-going vessels. In flow applications, the presence of biofilm typically results in a drag increase and may alter the turbulence in the adjacent boundary layer. Recent studies emphasize the severity of the drag penalty associated with soft biofouling and suggest potential mechanisms underlying the increase; yet, fundamental questions remain-such as the role played by compliance and the contribution of form drag to the overall resistance experienced by a fouled system. Experiments conducted on live biofilm and 3D printed rigid replicas in the Skin-Friction Flow Facility at the University of Michigan seek to examine these factors. The hydrodynamic performance of the biofilms grown on test panels was evaluated through pressure drop measurements as well as conventional and microscale PIV. High-resolution, 3D rigid replicas of select cases were generated via additive manufacturing using surface profiles obtained from a laser scanning system. Drag and flow measurements will be presented along with details of the growth process and the surface profile characterization method.

  5. Drag Reducing and Cavitation Resistant Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pease, Leonard F.


    Client, Green Building Systems (GBS), presented PNNL a coating reported to reduce drag and prevent cavitation damage on marine vessels, turbines and pumps. The composition of the coating remains proprietary but has as constituents including silicon oxides, aliphatic carbon chains, and fluorine rich particles. The coating is spray applied to surfaces. Prior GBS testing and experiments suggest reduction of both drag and cavitation on industrial scale propellers, but the underlying mechanism for these effects remains unclear. Yet, the application is compelling because even modest reductions in drag to marine vessels and cavitation to propellers and turbines present a significant economic and environmental opportunity. To discern among possible mechanisms, PNNL considered possible mechanisms with the client, executed multiple experiments, and completed one theoretical analysis (see appendix). The remainder of this report first considers image analysis to gain insight into drag reduction mechanisms and then exposes the coating to cavitation to explore its response to an intensely cavitating environment. Although further efforts may be warranted to confirm mechanisms, this report presents a first investigation into these coatings within the scope and resources of the technology assistance program (TAP).

  6. Drag coefficient Variability and Thermospheric models (United States)

    Moe, Kenneth

    Satellite drag coefficients depend upon a variety of factors: The shape of the satellite, its altitude, the eccentricity of its orbit, the temperature and mean molecular mass of the ambient atmosphere, and the time in the sunspot cycle. At altitudes where the mean free path of the atmospheric molecules is large compared to the dimensions of the satellite, the drag coefficients can be determined from the theory of free-molecule flow. The dependence on altitude is caused by the concentration of atomic oxygen which plays an important role by its ability to adsorb on the satellite surface and thereby affect the energy loss of molecules striking the surface. The eccentricity of the orbit determines the satellite velocity at perigee, and therefore the energy of the incident molecules relative to the energy of adsorption of atomic oxygen atoms on the surface. The temperature of the ambient atmosphere determines the extent to which the random thermal motion of the molecules influences the momentum transfer to the satellite. The time in the sunspot cycle affects the ambient temperature as well as the concentration of atomic oxygen at a particular altitude. Tables and graphs will be used to illustrate the variability of drag coefficients. Before there were any measurements of gas-surface interactions in orbit, Izakov and Cook independently made an excellent estimate that the drag coefficient of satellites of compact shape would be 2.2. That numerical value, independent of altitude, was used by Jacchia to construct his model from the early measurements of satellite drag. Consequently, there is an altitude dependent bias in the model. From the sparce orbital experiments that have been done, we know that the molecules which strike satellite surfaces rebound in a diffuse angular distribution with an energy loss given by the energy accommodation coefficient. As more evidence accumulates on the energy loss, more realistic drag coefficients are being calculated. These improved drag

  7. Significance of relative velocity in drag force or drag power estimation for a tethered float

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Sastry, J.S.

    There is difference in opinion regarding the use of relative velocity instead of particle velocity alone in the estimation of drag force or power. In the present study, a tethered spherical float which undergoes oscillatory motion in regular waves...

  8. Observation and Numerical Experiments for Drag Coefficient Under Typhoon Wind Forcing

    Institute of Scientific and Technical Information of China (English)

    CAO Huiqiu; ZHOU Liangming; LI Shuiqing; WANG Zhifeng


    This paper presents a study on drag coefficients under typhoon wind forcing based on observations and numerical experiments.The friction velocity and wind speed are measured at a marine observation platform in the South China Sea.Three typhoons:SOULIK (2013),TRAMI (2013) and FITOW (2013) are observed at a buoy station in the northeast sea area of Pingtan Island.A new parameterization is formulated for the wind drag coefficient as a function of wind speed.It is found that the drag coefficient (Ca) increases linearly with the slope of 0.083× 10-3 for wind speed less than 24 m s-1.To investigate the drag coefficient under higher wind conditions,three numerical experiments are implemented for these three typhoons using SWAN wave model.The wind input data are objective reanalysis datasets,which are assimilated with many sources and provided every six hours with the resolution of 0.125° ×0.125°.The numerical simulation results show a good agreement with wave observation data under typhoon wind forcing.The results indicate that the drag coefficient levels off with the linear slope of 0.012× 10-3 for higher wind speeds (less than 34 m s-1) and the new parameterization improvese the simulation accuracy compared with the Wu (1982) default used in SWAN.

  9. Wake-Model Effects on Induced Drag Prediction of Staggered Boxwings

    Directory of Open Access Journals (Sweden)

    Julian Schirra


    Full Text Available For staggered boxwings the predictions of induced drag that rely on common potential-flow methods can be of limited accuracy. For example, linear, freestream-fixed wake models cannot resolve effects related to wake deflection and roll-up, which can have significant affects on the induced drag projection of these systems. The present work investigates the principle impact of wake modelling on the accuracy of induced drag prediction of boxwings with stagger. The study compares induced drag predictions of a higher-order potential-flow method that uses fixed and relaxed-wake models, and of an Euler-flow method. Positive-staggered systems at positive angles of attack are found to be particularly prone to higher-order wake effects due to vertical contraction of wakes trajectories, which results in smaller effective height-to-span ratios than compared with negative stagger and thus closer interactions between trailing wakes and lifting surfaces. Therefore, when trying to predict induced drag of positive staggered boxwings, only a potential-flow method with a fully relaxed-wake model will provide the high-degree of accuracy that rivals that of an Euler method while being computationally significantly more efficient.

  10. On the Drag Effect of a Refuelling Pellet

    DEFF Research Database (Denmark)

    Chang, Tinghong; Michelsen, Poul


    A refueling pellet is subjected mainly to two kinds of drags: (1) inertial drag caused by the motion of the pellet relative to the surrounding plasma, and (2) ablation drag caused by an uneven ablation rate of the front and the rear surface of the pellet in an inhomogeneous plasma. Computational ...... results showed that for reasonable combinations of pellet size and injection speed, the drag effect is hardly detectable for plasma conditions prevailing in current large tokamaks....

  11. A network to enhance cooperation for research and higher education on radiation protection and nuclear engineering

    International Nuclear Information System (INIS)

    Rodenas, J.; Gallardo, Sergio . E mail:


    The educational capacity of many Institutions of Higher Education in Nuclear Engineering decreased under the combined effect of a declining interest among students as well as from academic and political authorities. An increasing cooperation at the international level on educational efforts is necessary. The CHERNE network is an initiative mainly focussed on teaching and learning activities to develop a wide-scope open academic network to enhance cooperation, competence and equipment sharing between its partners. Typical activities organized within the network include workshops, intensive courses, seminars and conferences. The CHERNE network and its main objectives as well as the activities developed since its foundation are presented. Special attention is given to international intensive courses (SPERANSA, JUNCSS, ICARO, etc.) organized for students of the member institutions. The common feature of these courses is a strong practical part in specialized facilities, including in some cases access to large equipment like research reactors and accelerators. (author)

  12. A Partnership Approach to Promoting Information Literacy for Higher Education Researchers

    Directory of Open Access Journals (Sweden)

    Stéphane Goldstein


    Full Text Available The promotion of information literacy in the UK higher education research sector has traditionally been the preserve of academic libraries. However, other professional groups have obvious interests in this area, and there is a strong case for providing a framework which enables different parties with a stake in information literacy to work together in order to reach practical objectives. In the UK, a coalition of partners has been set up to provide this collective framework and to provide synergy. This paper sets out the rationale for this approach, sets out the sort of activities that the coalition has fostered since its inception in late 2009 and reflects on whether it might serve as an example for other parts of Europe or for transnational collaborations.

  13. Riblet drag reduction in mild adverse pressure gradients: A numerical investigation

    International Nuclear Information System (INIS)

    Boomsma, Aaron; Sotiropoulos, Fotis


    Highlights: • We model several differently sized scalloped riblets using LES. • Riblets were modeled in both ZPG and mild APG and compared to each other and to a baseline (flat plate) case. • Scalloped riblets in the mild APG reduce drag only slightly more than those in ZPG. • Maximum values of streamwise turbulence intensities, streamwise vorticity, and TKE are proportional to riblet width. • Primary Reynolds shear stresses and turbulence energy production scale with riblet drag reduction. - Abstract: Riblet films are a passive method of turbulent boundary layer control that can reduce viscous drag. They have been studied with great detail for over 30 years. Although common riblet applications include flows with Adverse Pressure Gradients (APG), nearly all research thus far has been performed in channel flows. Recent research has provided motivation to study riblets in more complicated turbulent flows with claims that riblet drag reduction can double in mild APG common to airfoils at moderate angles of attack. Therefore, in this study, we compare drag reduction by scalloped riblet films between riblets in a zero pressure gradient and those in a mild APG using high-resolution large eddy simulations. In order to gain a fundamental understanding of the relationship between drag reduction and pressure gradient, we simulated several different riblet sizes that encompassed a broad range of s"+ (riblet width in wall units), similarly to many previously published experimental studies. We found that there was only a slight improvement in drag reduction for riblets in the mild APG. We also observed that peak values of streamwise turbulence intensity, turbulent kinetic energy, and streamwise vorticity scale with riblet width. Primary Reynolds shear stresses and turbulence kinetic energy production however scale with the ability of the riblet to reduce skin-friction.

  14. Education and Research in the SEENET-MTP Regional Framework for Higher Education in Physics (United States)

    Constantinescu, R.; Djordjevic, G. S.


    Southeastern European countries undergo significant changes in the demand/supply ratio on the labour market and in the structure of professional competences that are necessary for undertaking a professional activity. In addition, brain-drain process and decrease of interest for a career in basic sciences put many challenges for our community. Consequently, based on the activity of the Southeastern European Network in Mathematical and Theoretical Physics (SEENET MTP Network) in connecting groups and persons working in mathematics and theoretical physics, we investigate specific qualifications recognized in these fields in all the countries from the region, and the related competences necessary for practising the respective occupations. A list of new possible occupations will be promoted for inclusion in the National Qualifications Register for Higher Education. Finally, we analyze the vision existing in this region on the higher education qualifications against the European vision and experience, in particular in training of Master students, PhD students, and senior teaching and research staff through the Network, i.e. multilateral and bilateral programs.

  15. The advantages of creating a positive radiation safety culture in the higher education and research sectors

    International Nuclear Information System (INIS)

    Coldwell, T; Cole, P; Edwards, C; Makepeace, J; Murdock, C; Odams, H; Whitcher, R; Willis, S; Yates, L


    The safety culture of any organisation plays a critical role in setting the tone for both effective delivery of service and high standards of performance. By embedding safety at a cultural level, organisations are able to influence the attitudes and behaviours of stakeholders. To achieve this requires the ongoing commitment of heads of organisations and also individuals to prioritise safety no less than other competing goals (e.g. in universities, recruitment and retention are key) to ensure the protection of both people and the environment.The concept of culture is the same whatever the sector, e.g. medical, nuclear, industry, education, and research, but the higher education and research sectors within the UK are a unique challenge in developing a strong safety culture.This report provides an overview of the challenges presented by the sector, the current status of radiation protection culture, case studies to demonstrate good and bad practice in the sector and the practical methods to influence change. (practical matter)

  16. Governance of the research activities in higher educational institutions: factors and outcomes

    Directory of Open Access Journals (Sweden)

    Musawenkosi Ngibe


    Full Text Available South African higher education institutions, specifically, universities of technology have been faced with an arduous battle of increasing postgraduate students enrolment (masters and doctoral and improve their completion rate. However, the situation is exacerbated by inadequate number and inexperience of supervisors to supervise these postgraduate students. The Durban University of Technology has formulated research structures to administer and co-ordinate research activities in order to improve the number of staff members with doctoral qualifications in order to aid the current challenges. Therefore, the aim of this study is to evaluate the circumstances and factors hindering the academic staff throughput rates and the impact it has on the university. The use of qualitative and quantitative approach was used for this study, with closed and open-ended questionnaires used to collect data from 278 academic staff members using a probability sampling. The respondents 9 (4.9% indicated that lack of external funding and project management skills proved to be major contributory factors hindering academics staff to complete their postgraduate degrees within the required time. The study recommends that funding should be made easily available to academics pursuing doctoral studies, while project management workshops should be organised regularly to help academics appropriately management their studies. This can have a positive impact which will benefit the university and aid to the current crisis of lack of supervisor for masters and doctoral studies

  17. Resilient Learning: Towards Integration of Strategic Research Programmes, Higher Education Functions and Regional-National Development

    Directory of Open Access Journals (Sweden)

    Rauno Ilmari Pirinen


    Full Text Available In this study, the concept of Learning by Research and Development (R&D is furthered to the world of more resilient learning in the setting of security related R&D projects for development of co-creative products, services and action competence. The background of this study includes an interdisciplinary combination of service science, security, computer science, pedagogy, engineering, and management science. The interdisciplinary combination involves researchers, learners, teachers, and other participants connecting and integrating the academic disciplines, professions, and technologies, along with their methods and perspectives for co-creation of a common goal. This goal emphasizes results as high-value impacts, as well as the value of products, services, and innovations as “deliverables” of the integrative learning process. Until recently, the Learning by R&D model is clear and transparent; as such, it can be adopted by learning and R&D integration of other sciences and higher education institutions. The structure of the model is also easy to adapt and renew in case of a change, which means that it can develop from the inside on the one hand, and produce interactions, adaptions, resilience and innovations on the other.

  18. Conceptualising Food Research in Higher Education as a Matter of Social Justice: Philosophical, Methodological and Ethical Considerations (United States)

    Dominguez-Whitehead, Yasmine


    Globally, food concerns in higher education have emerged as an issue of critical importance. Food acquisition struggles and high rates of food insecurity among students have been documented, yet food within higher education continues to be an under-researched area of study. This paper calls for advancing research that critically engages with food…

  19. From Inventory to Insight: Making Sense of the Global Landscape of Higher Education Research, Training, and Publication (United States)

    Rumbley, Laura E.; Stanfield, David A.; de Gayardon, Ariane


    Through a yearlong study, the Boston College Center for International Higher Education developed a (third edition) global inventory of higher education research centers/institutes, academic programs, and journals/publications. As higher education expands globally, these resources are essential for training effective leaders and producing research…

  20. The Effect of Air Drag in Optimal Power-Limited Rendezvous Between Coplanar Low-Earth Orbits

    Directory of Open Access Journals (Sweden)

    Gil-Young Maeng


    Full Text Available The effect of air drag was researched when a low-earth orbit spacecraft using power-limited thruster rendezvoused another low-earth orbit spacecraft. The air density was assumed to decrease exponentially. The radius of parking orbit was 6655.935 km and that of target orbit was 7321.529 km. From the trajectories of active vehicles, the fuel consumption and the magnitude of thrust acceleration, we could conclude that the effect of air drag had to be considered in fuel optimal rendezvous problem between low-earth orbit spacecrafts. In multiple-revolution rendezvous case, the air drag was more effective.

  1. The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Concept and Research (United States)

    Baxley, B.; Williams, D.; Consiglio, M.; Adams, C.; Abbott, T.


    The ability to conduct concurrent, multiple aircraft operations in poor weather at virtually any airport offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase capacity at the 3400 non-radar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during low visibility or ceilings. The concept s key feature is that pilots maintain their own separation from other aircraft using air-to-air datalink and on-board software within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility and low ceilings around an airport without Air Traffic Control (ATC) services. While pilots self-separate within the SCA, an Airport Management Module (AMM) located at the airport assigns arriving pilots their sequence based on aircraft performance, position, winds, missed approach requirements, and ATC intent. The HVO design uses distributed decision-making, safe procedures, attempts to minimize pilot and controller workload, and integrates with today's ATC environment. The HVO procedures have pilots make their own flight path decisions when flying in Instrument Metrological Conditions (IMC) while meeting these requirements. This paper summarizes the HVO concept and procedures, presents a summary of the research conducted and results, and outlines areas where future HVO research is required. More information about SATS HVO can be found at

  2. Aerodynamic drag reduction by vertical splitter plates (United States)

    Gilliéron, Patrick; Kourta, Azeddine


    The capacity of vertical splitter plates placed at the front or the rear of a simplified car geometry to reduce drag, with and without skew angle, is investigated for Reynolds numbers between 1.0 × 106 and 1.6 × 106. The geometry used is a simplified geometry to represent estate-type vehicles, for the rear section, and MPV-type vehicle. Drag reductions of nearly 28% were obtained for a zero skew angle with splitter plates placed at the front of models of MPV or utility vehicles. The results demonstrate the advantage of adapting the position and orientation of the splitter plates in the presence of a lateral wind. All these results confirm the advantage of this type of solution, and suggest that this expertise should be used in the automotive field to reduce consumption and improve dynamic stability of road vehicles.

  3. Aerodynamic drag reduction by vertical splitter plates

    Energy Technology Data Exchange (ETDEWEB)

    Gillieron, Patrick [Renault Group, Research Division, Fluid Mechanics and Aerodynamics, Guyancourt (France); Kourta, Azeddine [Polytech' Orleans, Institut PRISME, ESA, Orleans (France)


    The capacity of vertical splitter plates placed at the front or the rear of a simplified car geometry to reduce drag, with and without skew angle, is investigated for Reynolds numbers between 1.0 x 10{sup 6} and 1.6 x 10{sup 6}. The geometry used is a simplified geometry to represent estate-type vehicles, for the rear section, and MPV-type vehicle. Drag reductions of nearly 28% were obtained for a zero skew angle with splitter plates placed at the front of models of MPV or utility vehicles. The results demonstrate the advantage of adapting the position and orientation of the splitter plates in the presence of a lateral wind. All these results confirm the advantage of this type of solution, and suggest that this expertise should be used in the automotive field to reduce consumption and improve dynamic stability of road vehicles. (orig.)

  4. Switchable and Tunable Aerodynamic Drag on Cylinders (United States)

    Guttag, Mark; Lopéz Jiménez, Francisco; Upadhyaya, Priyank; Kumar, Shanmugam; Reis, Pedro

    We report results on the performance of Smart Morphable Surfaces (Smporhs) that can be mounted onto cylindrical structures to actively reduce their aerodynamic drag. Our system comprises of an elastomeric thin shell with a series of carefully designed subsurface cavities that, once depressurized, lead to a dramatic deformation of the surface topography, on demand. Our design is inspired by the morphology of the giant cactus (Carnegiea gigantea) which possesses an array of axial grooves, thought to help reduce aerodynamic drag, thereby enhancing the structural robustness of the plant under wind loading. We perform systematic wind tunnel tests on cylinders covered with our Smorphs and characterize their aerodynamic performance. The switchable and tunable nature of our system offers substantial advantages for aerodynamic performance when compared to static topographies, due to their operation over a wider range of flow conditions.

  5. Lift vs. drag based mechanisms for vertical force production in the smallest flying insects. (United States)

    Jones, S K; Laurenza, R; Hedrick, T L; Griffith, B E; Miller, L A


    We used computational fluid dynamics to determine whether lift- or drag-based mechanisms generate the most vertical force in the flight of the smallest insects. These insects fly at Re on the order of 4-60 where viscous effects are significant. Detailed quantitative data on the wing kinematics of the smallest insects is not available, and as a result both drag- and lift-based strategies have been suggested as the mechanisms by which these insects stay aloft. We used the immersed boundary method to solve the fully-coupled fluid-structure interaction problem of a flexible wing immersed in a two-dimensional viscous fluid to compare three idealized hovering kinematics: a drag-based stroke in the vertical plane, a lift-based stroke in the horizontal plane, and a hybrid stroke on a tilted plane. Our results suggest that at higher Re, a lift-based strategy produces more vertical force than a drag-based strategy. At the Re pertinent to small insect hovering, however, there is little difference in performance between the two strategies. A drag-based mechanism of flight could produce more vertical force than a lift-based mechanism for insects at Re<5; however, we are unaware of active fliers at this scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Can large-scale oblique undulations on a solid wall reduce the turbulent drag? (United States)

    Ghebali, Sacha; Chernyshenko, Sergei I.; Leschziner, Michael A.


    Direct numerical simulations of fully developed turbulent channel flows with wavy walls are undertaken. The wavy walls, skewed with respect to the mean flow direction, are introduced as a means of emulating a Spatial Stokes Layer (SSL) induced by in-plane wall motion. The transverse shear strain above the wavy wall is shown to be similar to that of a SSL, thereby affecting the turbulent flow and leading to a reduction in the turbulent skin-friction drag. However, some important differences with respect to the SSL case are brought to light too. In particular, the phase variations of the turbulent properties are accentuated and, unlike in the SSL case, there is a region of increased turbulence production over a portion of the wall, above the leeward side of the wave, thus giving rise to a local increase in dissipation. The pressure- and friction-drag levels are carefully quantified for various flow configurations, exhibiting a combined maximum overall-drag reduction of about 0.6%. The friction-drag reduction is shown to behave approximately quadratically for small wave slopes and then linearly for higher slopes, whilst the pressure-drag penalty increases quadratically. The transverse shear-strain layer is shown to be approximately Reynolds-number independent when the wave geometry is scaled in wall units.

  7. Simulating Electrophoresis with Discrete Charge and Drag (United States)

    Mowitz, Aaron J.; Witten, Thomas A.

    A charged asymmetric rigid cluster of colloidal particles in saline solution can respond in exotic ways to an electric field: it may spin or move transversely. These distinctive motions arise from the drag force of the neutralizing countercharge surrounding the cluster. Because of this drag, calculating the motion of arbitrary asymmetric objects with nonuniform charge is impractical by conventional methods. Here we present a new method of simulating electrophoresis, in which we replace the continuous object and the surrounding countercharge with discrete point-draggers, called Stokeslets. The balance of forces imposes a linear, self-consistent relation among the drag and Coulomb forces on the Stokeslets, which allows us to easily determine the object's motion via matrix inversion. By explicitly enforcing charge+countercharge neutrality, the simulation recovers the distinctive features of electrophoretic motion to few-percent accuracy using as few as 1000 Stokeslets. In particular, for uniformly charged objects, we observe the characteristic Smoluchowski independence of mobility on object size and shape. We then discuss electrophoretic motion of asymmetric objects, where our simulation method is particularly advantageous. This work is supported by a Grant from the US-Israel Binational Science Foundation.

  8. Satellite drag effects due to uplifted oxygen neutrals during super magnetic storms (United States)

    Lakhina, Gurbax S.; Tsurutani, Bruce T.


    During intense magnetic storms, prompt penetration electric fields (PPEFs) through E × B forces near the magnetic equator uplift the dayside ionosphere. This effect has been called the dayside super-fountain effect. Ion-neutral drag forces between the upward moving O+ (oxygen ions) and oxygen neutrals will elevate the oxygen atoms to higher altitudes. This paper gives a linear calculation indicating how serious the effect may be during an 1859-type (Carrington) superstorm. It is concluded that the oxygen neutral densities produced at low-Earth-orbiting (LEO) satellite altitudes may be sufficiently high to present severe satellite drag. It is estimated that with a prompt penetrating electric field of ˜ 20 mV m-1 turned on for 20 min, the O atoms and O+ ions are uplifted to 850 km where they produce about 40-times-greater satellite drag per unit mass than normal. Stronger electric fields will presumably lead to greater uplifted mass.

  9. Entrepreneurial orientation, market orientation and performance of teachers and researchers in higher education institutions


    Felgueira, Teresa Maria Monteiro


    Higher Education has been the focus of significant growth in the last decades. In this context, the educational market has undergone some changes and competition among Institutions of Higher Education worldwide was established. Particularly, in Europe, there have been profound changes in the way education has been provided for by Higher Education Institutions (HEIs), according to Bologna process, allowing students to move freely between European Institutions of higher education...

  10. Research and Data Services for Higher Education Information Technology: Past, Present, and Future (United States)

    Grajek, Susan


    Those in the higher education community live in interesting times. For decades, higher education has occupied a relatively stable, trusted position in society, as a place to invest the most precious resources: (1) youth; (2) minds; (3) future; and (4) values. Today, the purpose and value of higher education is under question and under…

  11. Assessment Revisited: A Review of Research in "Assessment and Evaluation in Higher Education" (United States)

    Pereira, Diana; Flores, Maria Assunção; Niklasson, Laila


    A review of articles published in "Assessment and Evaluation in Higher Education," over the last eight years (2006-2013) on assessment in higher education, since the introduction of the Bologna process, is the subject of the paper. The first part discusses the key issue of assessment in higher education and the method used for selecting…

  12. Research on the Coordinative Development of Regional Higher Education and Economy (United States)

    Hong, Yingjun


    In the current society, economic development in any region has to rely on higher education. Conversely, higher education cannot do without regional economic development in order to achieve greater progress in scale and level. Starting with the function of higher education in Wenzhou, this paper analyzes the reality and problems in Wenzhou's higher…

  13. Why Do They Study There? Diary Research into Students' Learning Space Choices in Higher Education (United States)

    Beckers, Ronald; van der Voordt, Theo; Dewulf, Geert


    Higher education learning and teaching methods have changed while most educational buildings are still rather traditional. Yet, there is an increasing interest in whether we can educate today's higher education students in yesterday's buildings. This paper aims to contribute to this debate by studying the learning space choices of higher education…

  14. Hispanic Association of Colleges and Universities (HACU) Hispanic Higher Education Research Collective (H3ERC) Research Agenda: Impacting Education and Changing Lives through Understanding (United States)

    Hispanic Association of Colleges and Universities, 2011


    With support from the Lumina Foundation, the Hispanic Association of Colleges and Universities (HACU) has launched HACU's Hispanic Higher Education Research Collective (H3ERC). The first major task of this virtual gathering of researchers and practitioners in Hispanic higher education has been to assess the state of our knowledge of the key issues…

  15. The Role of Social Media for Collaborative Learning to Improve Academic Performance of Students and Researchers in Malaysian Higher Education (United States)

    Al-Rahmi, Waleed Mugahed; Othman, Mohd Shahizan; Yusuf, Lizawati Mi


    Social media is widely considered to improve collaborative learning among students and researchers. However, there is a surprising lack of empirical research in Malaysian higher education to improve performance of students and researchers through the effective use of social media that facilitates desirable outcomes. Thus, this study offers a…

  16. Fluid drag reduction and efficient self-cleaning with rice leaf and butterfly wing bioinspired surfaces (United States)

    Bixler, Gregory D.; Bhushan, Bharat


    Researchers are continually inspired by living nature to solve complex challenges. For example, unique surface characteristics of rice leaves and butterfly wings combine the shark skin (anisotropic flow leading to low drag) and lotus leaf (superhydrophobic and self-cleaning) effects, producing the so-called rice and butterfly wing effect. In this paper, we present an overview of rice leaf and butterfly wing fluid drag and self-cleaning studies. In addition, we examine two other promising aquatic surfaces in nature known for such properties, including fish scales and shark skin. Morphology, drag, self-cleaning, contact angle, and contact angle hysteresis data are presented to understand the role of wettability, viscosity, and velocity. Liquid repellent coatings are utilized to recreate or combine various effects. Discussion is provided along with conceptual models describing the role of surface structures related to low drag, self-cleaning, and antifouling properties. Modeling provides design guidance when developing novel low drag and self-cleaning surfaces for applications in the medical, marine, and industrial fields.

  17. Higher tier field research in ecological risk assessment: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Faber, J. [Alterra, Wageningen (Netherlands)


    A newly developed basic procedure for site-specific ecological risk assessment in The Netherlands was followed in practice for the first time. In line with conventional Triade approaches, the procedure includes multidisciplinary parameters from environmental chemistry, toxicology and ecology to provide multiple weight of evidence. However, land use at the contaminated site and its vicinity is given more importance, and research parameters are selected in accordance to specific objectives for land use in order to test for harmful effects to underlying ecosystem services. Moreover, the approach is characterized by repetitive interactions between stakeholders and researching consultants, in particular with respect to the choice of parameters and criteria to assess the results. The approach was followed in an ecological risk assessment to test the assumptions underlying a soil management plant for a rural area in The Netherlands, called 'Krimpenerwaard'. Throughout this region some 5000 polder ditches have been filled with waste materials originating from local households, waterway sludge, industrial wastes, car shredders, and more. Several sites are severely polluted by heavy metals, cyanide, PAH or chlorinated hydrocarbons and require remediation or clean up. However, the exact distribution of these wastes over the entire region is scarcely known, and the Krimpenerwaard as a whole is treated as one case of serious soil pollution. A soil management plan was constructed by 13 stakeholding parties, aiming for a 'functional clean up' in view of land use, by means of covering 'suspected' categories of wastes with a 30-cm layer of local type soil. The ecological risk assessment aims to verify the assumptions in the soil management plan regarding the prevention of possible undesirable effects induced by the various waste materials. A tiered approach is followed, including a screening for bioavailable contaminants, a testing for general effects

  18. Thermospheric density and satellite drag modeling (United States)

    Mehta, Piyush Mukesh

    The United States depends heavily on its space infrastructure for a vast number of commercial and military applications. Space Situational Awareness (SSA) and Threat Assessment require maintaining accurate knowledge of the orbits of resident space objects (RSOs) and the associated uncertainties. Atmospheric drag is the largest source of uncertainty for low-perigee RSOs. The uncertainty stems from inaccurate modeling of neutral atmospheric mass density and inaccurate modeling of the interaction between the atmosphere and the RSO. In order to reduce the uncertainty in drag modeling, both atmospheric density and drag coefficient (CD) models need to be improved. Early atmospheric density models were developed from orbital drag data or observations of a few early compact satellites. To simplify calculations, densities derived from orbit data used a fixed CD value of 2.2 measured in a laboratory using clean surfaces. Measurements from pressure gauges obtained in the early 1990s have confirmed the adsorption of atomic oxygen on satellite surfaces. The varying levels of adsorbed oxygen along with the constantly changing atmospheric conditions cause large variations in CD with altitude and along the orbit of the satellite. Therefore, the use of a fixed CD in early development has resulted in large biases in atmospheric density models. A technique for generating corrections to empirical density models using precision orbit ephemerides (POE) as measurements in an optimal orbit determination process was recently developed. The process generates simultaneous corrections to the atmospheric density and ballistic coefficient (BC) by modeling the corrections as statistical exponentially decaying Gauss-Markov processes. The technique has been successfully implemented in generating density corrections using the CHAMP and GRACE satellites. This work examines the effectiveness, specifically the transfer of density models errors into BC estimates, of the technique using the CHAMP and

  19. CFD Study of Drag and Lift of Sepak Takraw Ball at Different Face Orientations

    Directory of Open Access Journals (Sweden)

    Abdul Syakir Abdul Mubin


    Full Text Available There have been a significant number of researches on computational fluid dynamic (CFD analysis of balls used in sports such as golf balls, tennis balls, and soccer balls. Sepak takraw is a high speed court game predominantly played in Southeast Asia using mainly the legs and head. The sepak takraw ball is unique because it is not enclosed and made of woven plastic. Hence a study of its aerodynamicswould give insight into its behaviour under different conditions of play. In this study the dynamics of the fluid around a static sepak takraw ball was investigated at different wind speeds for three different orientations using CFD. It was found that although the drag did not differ very much, increasing the wind velocity causes an increase in drag. The lift coefficientvaries as the velocity increases and does not show a regular pattern. The drag and lift coefficients are influenced by the orientation of the sepak takraw ball.



    Pooja. S.


    The present study aims to find out the awareness of Higher Secondary School English teachers on Multiple Intelligences. Each teacher needs to be aware of different forms of intelligences. The objectives of the study are to find out the level of awareness of Higher Secondary School teachers on Multiple Intelligences and to compare the awareness on Multiple Intelligences among Higher Secondary School teachers based on gender and locality. Survey method is used for collecting data from 150 highe...

  1. Effective Self-Regulatory Processes in Higher Education: Research Findings and Future Directions. A Systematic Review (United States)

    de Bruijn-Smolders, Monique; Timmers, Caroline F.; Gawke, Jason C. L.; Schoonman, Wouter; Born, Marise Ph.


    Although self-regulated learning (SRL) is assumed to benefit learning outcomes, gaps in the literature make it difficult to describe what constitutes effective SRL in higher education. That is, SRL that relates positively to learning outcomes. In accordance, at present it is unclear how to train effective SRL in higher education. The current…

  2. From "Crisis" to "Transformation"? Shifting Orthodoxies of African Higher Education Policy and Research (United States)

    Lebeau, Yann; Mills, David


    After years of neglect, there is renewed international interest in higher education in sub-Saharan Africa. Comparative projects have been launched on a continental scale, looking at the socio-economic relevance of higher education, often with the aim of reviving failing institutions. A new "transformation" policy paradigm has replaced a…

  3. Governance and Adaptation to Innovative Modes of Higher Education Provision. Research Report (United States)

    McGrath, Cecile Hoareau; Hofman, Joanna; Bajziková, Lubica; Harte, Emma; Lasakova, Anna; Pankowska, Paulina; Sasso, S.; Belanger, Julie; Florea, S.; Krivogra, J.


    At a time when more students than ever are attending higher education, its provision is becoming more fluid, global and competitive. For example, developments in new technologies mean that higher education institutions (HEIs) can make their courses available all over the world. These developments bring into question the traditional delivery model…

  4. Why do they study there? Diary research into students' learning space choices in higher education

    NARCIS (Netherlands)

    Beckers, Ronald; van der Voordt, Theo; Dewulf, Geert P.M.R.


    Higher education learning and teaching methods have changed while most educational buildings are still rather traditional. Yet, there is an increasing interest in whether we can educate today's higher education students in yesterday's buildings. This paper aims to contribute to this debate by

  5. Why do they study there? Diary research into students’ learning space choices in higher education

    NARCIS (Netherlands)

    Beckers, R.; van der Voordt, Theo; DeWulf, Geert


    Higher education learning and teaching methods have changed while most educational buildings are still rather traditional. Yet, there is an increasing interest in whether we can educate today's higher education students in yesterday's buildings. This paper aims to contribute to this debate by

  6. Why do they study there? Diary research into students’ learning space choices in higher education

    NARCIS (Netherlands)

    Geert Dewulf; Theo van der Voordt; Ronald Beckers


    Higher education learning and teaching methods have changed while most educational buildings are still rather traditional. Yet, there is an increasing interest in whether we can educate today's higher education students in yesterday's buildings. This paper aims to contribute to this debate by


    DEFF Research Database (Denmark)

    Howard, Thomas J.; McMahon, C.A.; Giess, M.D.


    . However, with the aid of available government funding, researchers could benefit from undertaking such support work to fill gaps between fixed term research contracts; though administering short term irregular contracts proved a major unresolved barrier. It is recommended that engineering design...... researchers work as projects managers to provide technology and knowledge transfer, drawing further expertise from researchers within their universities. A trail case was completed showing identifying three key barriers to future progress....

  8. Predicting Supervisor Capacities to Foster Higher Forms of Learning through Undergraduate Medical Student Research (United States)

    MacDougall, Margaret


    The credibility of short-term undergraduate research as a paradigm for effective learning within Medicine has been recognized. With a view to strengthening this paradigm and enhancing research-teaching linkages, this study explores whether particular types of research supervisor are pre-disposed to providing supportive learning environments.…

  9. e-Leadership in Higher Education: The Fifth "Age" of Educational Technology Research (United States)

    Jameson, Jill


    A discussion of the relative lack of research into e-leadership in educational technology in education is followed by an outline of selected prior literature in the field. The paper proposes that, as part of a natural evolution of educational technology research, considerably more attention needs to be focused on research and development in…

  10. Conceptualising Multilingual Capabilities in Anglophone Higher Degree Research Education: Challenges and Possibilities for Reconfiguring Language Practices and Policies (United States)

    Liu, Wei


    In a context of the internationalisation of Higher Education (HE) driven by the high mobility of international Higher Degree Research candidates (HDRs), it is important to consider the value of HDRs' multilingual capabilities for their learning and making of original contributions to knowledge. This article reports on a literature study regarding…

  11. Development of a New Drag Coefficient Model for Oil and Gas ...

    African Journals Online (AJOL)

    Development of a New Drag Coefficient Model for Oil and Gas Multiphase Fluid Systems. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... suspensions of solid particles are frequently encountered in many industrial processes including oil & gas production. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  12. Enhancing research capacity across healthcare and higher education sectors: development and evaluation of an integrated model

    Directory of Open Access Journals (Sweden)

    Whitworth Anne


    Full Text Available Abstract Background With current policy in healthcare research, in the United Kingdom and internationally, focused on development of research excellence in individuals and teams, building capacity for implementation and translation of research is paramount among the professionals who use that research in daily practice. The judicious use of research outcomes and evaluation of best evidence and practice in healthcare is integrally linked to the research capacity and capabilities of the workforce. In addition to promoting high quality research, mechanisms for actively enhancing research capacity more generally must be in place to address the complexities that both undermine and facilitate this activity. Methods A comprehensive collaborative model for building research capacity in one health professional group, speech and language therapy, was developed in a region within the UK and is presented here. The North East of England and the strong research ethos of this profession in addressing complex interventions offered a fertile context for developing and implementing a model which integrated the healthcare and university sectors. Two key frameworks underpin this model. The first addresses the individual participants’ potential trajectory from research consciousness to research participative to research active. The second embeds a model developed for general practitioners into a broader framework of practice-academic partnership and knowledge and skills exchange, and considers external drivers and impacts on practice and patient outcomes as key elements. Results and discussion The integration of practice and academia has been successful in building a culture of research activity within one healthcare profession in a region in the UK and has resulted, to date, in a series of research related outcomes. Understanding the key components of this partnership and the explicit strategies used has driven the implementation of the model and are discussed

  13. Research on Implementation of the Teaching Process in Higher Vocational Curriculum


    Songjie Gong


    The implementation of the teaching process is the main channel to carry out good education. The aim of the implementation of the teaching process is to place emphasis on cultivating students’ innovation ability and take innovation education as the point to deepen higher vocational teaching reformation. The reform of project curriculum has become the main trend of course reform in higher vocational education. The traditional curriculum teaching process has shown some disadvantages in the teach...

  14. Fuel Savings and Aerodynamic Drag Reduction from Rail Car Covers (United States)

    Storms, Bruce; Salari, Kambiz; Babb, Alex


    The potential for energy savings by reducing the aerodynamic drag of rail cars is significant. A previous study of aerodynamic drag of coal cars suggests that a 25% reduction in drag of empty cars would correspond to a 5% fuel savings for a round trip [1]. Rail statistics for the United States [2] report that approximately 5.7 billion liters of diesel fuel were consumed for coal transportation in 2002, so a 5% fuel savings would total 284 million liters. This corresponds to 2% of Class I railroad fuel consumption nationwide. As part of a DOE-sponsored study, the aerodynamic drag of scale rail cars was measured in a wind tunnel. The goal of the study was to measure the drag reduction of various rail-car cover designs. The cover designs tested yielded an average drag reduction of 43% relative to empty cars corresponding to an estimated round-trip fuel savings of 9%.

  15. Elluminate Article: Research on Formal Virtual Learning Communities in Higher Education

    Directory of Open Access Journals (Sweden)

    Richard Schwier


    Full Text Available The publisher of IRRODL, The Canadian Institute of Distance Education Research (CIDER, is pleased to link here to a series of eight online seminars that took place over Spring 2005, using Elluminate live e-learning and collaborative solutions. These interactive CIDER Sessions disseminate research emanating from Canada's vibrant DE research community, and we feel these archived recordings are highly relevant to many in the international distance education research community. To access these sessions, you must first download FREE software. Visit to download this software.

  16. Workplace Influences on Chinese TEFL Academics' Development as Researchers: A Study of Two Chinese Higher Education Institutions (United States)

    Bai, Li; Millwater, Jan; Hudson, Peter


    Workplace influences on Chinese Teaching English as a Foreign Language (TEFL) academics' development as researchers were examined in two Chinese higher education institutions in this qualitative collective case study. Data sources included research documentation and interviews with 12 Chinese TEFL academics. Both institutions were keen on research…

  17. E-Portfolios and Personalized Learning: Research in Practice with Two Dyslexic Learners in UK Higher Education (United States)

    Hughes, Julie; Herrington, Margaret; McDonald, Tess; Rhodes, Amy


    This paper analyses the use of an e-portfolio system in contributing to the personalized learning of two dyslexic learners at the University of Wolverhampton, UK. The rationale for this research rests at the intersection of generic findings from e-portfolio (and wider e-learning) research and the still challenging project in higher education (HE)…

  18. Considering Teaching Excellence in Higher Education: 2007-2013. A Literature Review since the CHERI Report 2007. HEA Research Series (United States)

    Gunn, Vicky; Fisk, Anna


    This research review explores both the research and the grey literature on university teaching excellence with a specific remit to update an earlier review, "Excellence in Teaching and Learning: a review of literature for the Higher Education Academy". Little, B., et al (2007) The two main aims are: (1) to suggest further areas of…

  19. Just-in-Time Research: A Call to Arms for Research into Mobile Technologies in Higher Education (United States)

    Byrne-Davis, Lucie; Dexter, Hilary; Hart, Jo; Cappelli, Tim; Byrne, Ged; Sampson, Ian; Mooney, Jane; Lumsden, Colin


    Mobile technologies are becoming commonplace in society and in education. In higher education, it is crucial to understand the impact of constant access to information on the development of the knowledge and competence of the learner. This study reports on a series of four surveys completed by UK-based medical students (n = 443) who received…

  20. A Collaborative Action Research Project towards Embedding ESD within the Higher Education Curriculum (United States)

    Cebrián, Gisela


    Purpose: This paper aims to present a collaborative action research project conducted at the University of Southampton with the aim to promote curriculum and professional development in education for sustainable development (ESD) and learn from everyday practices of academics. Design/methodology/approach: An action research approach guided by…

  1. A Triangular Approach to Integrate Research, Education and Practice in Higher Engineering Education (United States)

    Heikkinen, Eetu-Pekka; Jaako, Juha; Hiltunen, Jukka


    Separate approaches in engineering education, research and practice are not very useful when preparing students for working life; instead, integration of education, research and industrial practices is needed. A triangular approach (TA) as a method to accomplish this integration and as a method to provide students with integrated expertise is…

  2. On design-oriented research and digital learning materials in higher education

    NARCIS (Netherlands)

    Hartog, R.J.M.


    The context of the research described in this thesis is formed by a number of research projects that were aimed at the design, development, implementation, use and evaluation of innovative digital learning materials. Most of these projects were carried out mainly within Wageningen University. In

  3. Establishing research universities in Ukrainian higher education: the incomplete journey of a structural reform

    NARCIS (Netherlands)

    Hladchenko, Myroslava; de Boer, Harry F.; Westerheijden, Donald F.


    The idea of the research university as a key institution for social and economic development in knowledge-intensive societies has been adopted by the Ukrainian government after the fall of the communist regime. Establishing research universities is a long journey during which many things might

  4. Knowledge Sharing among Academics in Institutions of Higher Learning: A Research Agenda (United States)

    Ramayah, T.; Ignatius, Joshua; Leen, Jasmine Yeap Ai


    This paper presents a research agenda for a funded research project on knowledge sharing among academics in Malaysia. One of the main objectives is to develop validate and measure of knowledge sharing which is suitable for academicians. Previous studies on knowledge sharing have used standard measurement items which do not cater for the multiple…

  5. Electronics and telecommunications in Poland, issues and perspectives: Part II. Science, research, development, higher education (United States)

    Modelski, Józef; Romaniuk, Ryszard


    Electronics is under development in this country in an organized and institutional way since the beginning of 30-ties of the previous century. It grew up from electrical engineering of weak currents and its first name used popularly was communications. It was time when television was born and the radio was maturing. Electronics is a branch of research and technology which deals with generation and processing of electrical and electromagnetic signals. A subject of telecommunications is signal transmission for a distance. Electronics and telecommunications (ET) includes or is combined with other branches like: microelectronics, radioelectronics, optoelectronics, photonics, acoustoelectronics, magnetronics, bioelectronics, energoelectronics, material engineering, semiconductor physics, automation and robotics, mechatronics and microsystems, informatics, teleinformatics, software engineering and other. Devices and functional systems of ET such as computers, data warehouses, cell phones, TV sets, Internet, GPS are build of electronic components and circuits. ET is a branch which belongs to hi-tech area, where the products gather a large load of knowledge of value overcoming frequently the price of work and material. ET has recently turned to an active participant of the processes of generation, storing, processing, transportation, distribution and usage of knowledge in the society. ET started to create artificial intelligence, co-creates intellectual property, searches for knowledge in big data sets, aids medicine, extends virtual/augmented reality, builds Internet of persons and things, strengthens security, protects natural environment, facilitates our life, aids our decisions, activates individuals, equalizes chances, provides convenient personal communications and access to data, starts building a penetrating ubiquitous infrastructure, ceases to be only a branch of technology, grows into the social space, touches culture, sociology, psychology and art. Such an

  6. Pengaruh Penempatan Penghalang Berbentuk Silinder Pada Posisi Vertikal Dengan Variasi Jarak Horisontal Di Depan Silinder Utama Terhadap Koefisien Drag

    Directory of Open Access Journals (Sweden)

    Si Putu Gede Gunawan Tista


    Full Text Available One of the ways to reduce energy consumption on the air plane and the other bluff bodies are by decreasing the drag. Dragis closely related to the flow separation. The earlier separation, then the drag will increase more. Based of the fact the effortto decrease drag is conducted by manipulating the field of fluid flow. Stream manipulation was be done by installingcylindrical obstacle in front of main cylinder. The purpose of this research is to analyze the effect of placement cylindricalobstacle at vertical position in the various horizontal distance in front of main cylinder on drag coefficient . In thisresearch, the experiment was conducted in the wind tunnel, which consisted of blower, pitot pipe, manometer, cylinder pipe,and cylinder rod. The cylindrical obstacle was positioned at vertical (y=14 mm in the various horizontal distanceL/D = 1.41, L/D = 1.56, L/D = 1.72, L/D = 1.88, L/D = 2.03, L/D = 2.19, and L/D = 2.81 by upstream from the maincylinder. Diameter cylinder obstacle was 8 mm.. The Reynolds number based on the main cylinder diameter (D = 42 mmwas Re = 3.42 x 104. The research results showed that the cylinder rod could decrease the drag coefficient of main cylinder.Drag coefficient for cylinder without cylinder rod was 0.167 while the biggest decrease of coefficient of drag with cylindricalobstacle was happened at L/D = 1.72 which was 0,0593. It means that the drag coefficient of main cylinder with cylindricalobstacle was 64.5% lower than the cylinder alone.

  7. Engineering drag currents in Coulomb coupled quantum dots (United States)

    Lim, Jong Soo; Sánchez, David; López, Rosa


    The Coulomb drag phenomenon in a Coulomb-coupled double quantum dot system is revisited with a simple model that highlights the importance of simultaneous tunneling of electrons. Previously, cotunneling effects on the drag current in mesoscopic setups have been reported both theoretically and experimentally. However, in both cases the sequential tunneling contribution to the drag current was always present unless the drag level position were too far away from resonance. Here, we consider the case of very large Coulomb interaction between the dots, whereby the drag current needs to be assisted by cotunneling events. As a consequence, a quantum coherent drag effect takes place. Further, we demonstrate that by properly engineering the tunneling probabilities using band tailoring it is possible to control the sign of the drag and drive currents, allowing them to flow in parallel or antiparallel directions. We also show that the drag current can be manipulated by varying the drag gate potential and is thus governed by electron- or hole-like transport.

  8. Drag reduction through self-texturing compliant bionic materials


    Eryong Liu; Longyang Li; Gang Wang; Zhixiang Zeng; Wenjie Zhao; Qunji Xue


    Compliant fish skin is effectively in reducing drag, thus the design and application of compliant bionic materials may be a good choice for drag reduction. Here we consider the drag reduction of compliant bionic materials. First, ZnO and PDMS mesh modified with n-octadecane were prepared, the drag reduction of self-texturing compliant n-octadecane were studied. The results show that the mesh modified by ZnO and PDMS possess excellent lipophilic and hydrophobic, thus n-octadecane at solid, sem...

  9. The research of approaches of applying the results of big data analysis in higher education (United States)

    Kochetkov, O. T.; Prokhorov, I. V.


    This article briefly discusses the approaches to the use of Big Data in the educational process of higher educational institutions. There is a brief description of nature of big data, their distribution in the education industry and new ways to use Big Data as part of the educational process are offered as well. This article describes a method for the analysis of the relevant requests by using Yandex.Wordstat (for laboratory works on the processing of data) and Google Trends (for actual pictures of interest and preference in a higher education institution).

  10. The Construction of Higher Education Entrepreneur Services Network System a Research Based on Ecological Systems Theory (United States)

    Xue, Jingxin

    The article aims to completely, systematically and objectively analyze the current situation of Entrepreneurship Education in China with Ecological Systems Theory. From this perspective, the author discusses the structure, function and its basic features of higher education entrepreneur services network system, and puts forward the opinion that every entrepreneurship organization in higher education institution does not limited to only one platform. Different functional supporting platforms should be combined closed through composite functional organization to form an integrated network system, in which each unit would impels others' development.

  11. Drag Reduction Through Distributed Electric Propulsion (United States)

    Stoll, Alex M.; Bevirt, JoeBen; Moore, Mark D.; Fredericks, William J.; Borer, Nicholas K.


    One promising application of recent advances in electric aircraft propulsion technologies is a blown wing realized through the placement of a number of electric motors driving individual tractor propellers spaced along each wing. This configuration increases the maximum lift coefficient by providing substantially increased dynamic pressure across the wing at low speeds. This allows for a wing sized near the ideal area for maximum range at cruise conditions, imparting the cruise drag and ride quality benefits of this smaller wing size without decreasing takeoff and landing performance. A reference four-seat general aviation aircraft was chosen as an exemplary application case. Idealized momentum theory relations were derived to investigate tradeoffs in various design variables. Navier-Stokes aeropropulsive simulations were performed with various wing and propeller configurations at takeoff and landing conditions to provide insight into the effect of different wing and propeller designs on the realizable effective maximum lift coefficient. Similar analyses were performed at the cruise condition to ensure that drag targets are attainable. Results indicate that this configuration shows great promise to drastically improve the efficiency of small aircraft.

  12. Pengaruh variasi jarak antar ring berbentuk segi empat pada permukaan silinder terhadap koefisien drag

    Directory of Open Access Journals (Sweden)

    Si Putu Gede Gunawan Tista


    cylinder surface on the drag coefficient.This research was conducted in wind tunnel which consists of a blower (forblowing air, pitot pipe, U-tube manometer, inclined manometer, digital balance, cylinder with a rectangular ring. Theresearch was carried out by varying the distance between the ring i.e. 30 mm, 40 mm, 50 mm, 60 mm and 70 mm,respectively. The cylinder is placed in a vertical wind tunnel with a diameter D = 60 mm. The drag force is obtained byusing a digital balance that records the amount of mass, and then multiplied by the acceleration due to gravity. Thepressure distribution is obtained by measuring the pressure in the cylinder surface using inclined manometer on 36points with 10o intervals. The results showed that the greater the distance between the rings increased the dragcoefficient. The lowest drag coefficient was achieved at rhe distance between ring L = 30 mm or L/D = 0.50, with the CDvalue = 0.606352; that is equivalent to 29.3% drag reduction.Keywords: Cylinder, rectangular ring, space between ring, drag coefficient

  13. Integrating Disciplinary Perspectives into Higher Education Research: The Example of History (United States)

    Eisenmann, Linda


    This article uses the discipline of history to explore these questions. While not a teeming group, historians of higher education have employed their disciplinary lens to advance several lines of significant postsecondary inquiry (for example, issues of access, social mobility, professionalism, gender, and regionalism). This article first traces…

  14. The Supply of Part-Time Higher Education in the UK. Research Report (United States)

    Callender, Claire; Birkbeck, Anne Jamieson; Mason, Geoff


    This report explores the supply of part-time higher education in the UK, with particular consideration to the study of part-time undergraduate provision in England. It is the final publication in the series of reports on individual student markets that were commissioned by Universities UK following the publication of the reports on the Future size…

  15. European Responses to Global Competitiveness in Higher Education. Research & Occasional Paper Series: CSHE.7.09 (United States)

    van der Wende, Marijk


    The growing global competition in which knowledge is a prime factor for economic growth is increasingly shaping policies and setting the agenda for the future of European higher education. With its aim to become the world's leading knowledge economy, the European Union is concerned about its performance in the knowledge sector, in particular in…

  16. Higher Education and Equality of Opportunitly:A Survey of Recent Cross-National Research

    Directory of Open Access Journals (Sweden)

    Fred A.Lazin


    Full Text Available Rising costs of education at the start of the 21st century seem to indicate a stark shift in education policies, which raises several important questions. The author shows that from the United States to East Asia and Australia – seemingly everywhere – higher education policy is headed in the same direction. The movement to broaden access to public universities, the dominant strategy during the 1970s and 1980s, has largely shifted to enable the marketplace, rather than the government, to shape the contours of higher education. Government funding is being reduced, affirmative action and other programs designed to insure broader access are in decline, and personal fulfilment is replacing a public good designed to insure greater equality of opportunity. The author describes how this sea of change in higher education has played out in economically developed and developing countries. In trying to provide the answer to the above-mentioned development, the author raises the question related to the consequences of a market-driven higher education for student access, teaching and scholarship.

  17. An Innovative Research on the Usage of Facebook in the Higher Education Context of Hong Kong (United States)

    Lam, Louis


    Teaching and learning is undergoing a dramatic change due to the advancement in telecommunication and IT. Increasingly, online learning platform is playing an important role higher education. The maturity of Internet and emergence of various cloud services catalyse the development of these platforms and student learning behaviour. An example is…

  18. The Changing Profile of College Students. ERIC/Higher Education Research Report No. 10, 1973. (United States)

    Fenske, Robert H.; Scott, Craig S.

    This report reviews recent literature concerning enrollment trends in higher education and also presents the results of a recently completed extensive survey of student characteristics. In general, there is a declining rate of enrollment, while at the same time diversity among students is on the increase. This study should be of value to those…

  19. Inclusion of Disability Issues in Teaching and Research in Higher Education (United States)

    Ohajunwa, Chioma; Mckenzie, Judith; Hardy, Anneli; Lorenzo, Theresa


    Evidence suggests that the lack of inclusion of disability issues in the curricula of higher education institutions may result in the perpetuation of practices that discriminate against disabled people in the broader society. In light of this claim, this article investigates whether and how disability issues are included in the teaching and…

  20. Supply and Demand in the Higher Education Market: College Enrollment. Research Brief (United States)

    Kumar, Amal; Hurwitz, Michael


    Higher education in the United States is a complex and multilayered system where open-access community colleges coexist with highly selective, 4-year institutions to which only a handful of students each year gain access. Each institution plays a unique role in this marketplace, and students across the spectrum engage with the system at…

  1. Generating Ethnographic Research Questions: An Anthropological Contribution to the Study of Higher Education (United States)

    Friberg, Torbjörn


    As part of recent complex transformations, it seems that higher educational organisations are being forced to reorganise, standardise and streamline in order to survive in the new political and economic context. How are ethnographers in general going to approach these contemporary phenomena? By drawing on the conceptual history of anthropology,…

  2. Evaluation and Development of Administrators. AAHE-ERIC/Higher Education Research Report No. 6, 1979. (United States)

    Nordvall, Robert C.

    Needs and methods for the evaluation and development of higher education administrators are reviewed in this monograph. Three major reasons for evaluation are cited: external and internal pressure, improvement of performance of individual administrators, and improvement of performance of the institution. Different approaches to evaluation are…

  3. Toward a Definition of Verbal Reasoning in Higher Education. Research Report. ETS RR-09-33 (United States)

    Burton, Nancy W.; Welsh, Cynthia; Kostin, Irene; VanEssen, Thomas


    This paper briefly summarizes the literatures of reading and reasoning in the last quarter century, focusing mainly on the disciplines of cognitive science, cognitive developmental psychology, linguistics, and educational psychology. These literatures were synthesized to create a framework for defining verbal reasoning in higher education. Eight…

  4. Critical Race Theory and Research on Asian Americans and Pacific Islanders in Higher Education (United States)

    Teranishi, Robert T.; Behringer, Laurie B.; Grey, Emily A.; Parker, Tara L.


    In this article, the authors offer critical race theory (CRT) as an alternative theoretical perspective that permits the examination and transcendence of conceptual blockages, while simultaneously offering alternative perspectives on higher education policy and practice and the Asian American and Pacific Islander (AAPI) student population. The…

  5. Trends and Issues in Educational Technology Research in Saudi Higher Education: A Meta-Analysis Review (United States)

    Alkraiji, Abdullah; Eidaroos, Abdulhadi


    As Information Technology expands, all industries and fields in Saudi Arabia are experiencing reduced costs and improvements in the efficiency and effectiveness of operations in various systems. This has positioned the higher education sector in Saudi Arabia as the land of opportunity in terms of educational technology and its ability to support…

  6. Effective self-regulatory processes in higher education: research findings and future directions. A systematic review

    NARCIS (Netherlands)

    M. de Bruijn-Smolders (Monique); C.F. Timmers (Caroline); J.C. Gawke (Jason); W. Schoonman (Wouter); M.Ph. Born (Marise)


    textabstractAlthough self-regulated learning (SRL) is assumed to benefit learning outcomes, gaps in the literature make it difficult to describe what constitutes effective SRL in higher education. That is, SRL that relates positively to learning outcomes. In accordance, at present it is unclear how

  7. Holding Tight or at Arm's Length: How Higher Education Regional Accrediting Bodies Address PLA. Research Brief (United States)

    Council for Adult and Experiential Learning, 2014


    Prior learning assessment (PLA) is the term used for the various ways in which higher education institutions and other organizations assess an individual's learning for the purposes of granting college credit, certification, or advanced standing in a postsecondary education program. In recent years, there has been growing interest in PLA from…

  8. Transnational Capacity Building: An Australian-Danish Partnership Model for Higher Education and Research in Nursing

    DEFF Research Database (Denmark)

    Rasmussen, Bodil; Kolbæk, Raymond; Lorentzen, Vibeke


    Aim: The article describes how a three level nursing partnership program between Australia and Denmark evolved and how barriers can be diminished when built on guiding principles of: professional trust, mutual understanding and respect for each other’s social, educational and cultural conditions...... and expertise across international borders as an important vehicle for developing nursing practice and research. Conclusion: The Australian-Danish education and research partnership program demonstrates that exchanging experiences can create opportunities for nurses’ professional growth, to advance careers...

  9. The Contemporary Academic: Orientation towards Research Work and Researcher Identity of Higher Education Lecturers in the Health Professions (United States)

    Boyd, Pete; Smith, Caroline


    Internationally, the increasing emphasis in universities on the quality of teaching, on student employability and on a corporate approach to entrepreneurial income generation has created a tension around the primacy afforded to published research outputs as a focus for academic work and status. In this study, a framework for academic socialisation…

  10. Fluid Mechanics, Drag Reduction and Advanced Configuration Aeronautics (United States)

    Bushnell, Dennis M.


    This paper discusses Advanced Aircraft configurational approaches across the speed range, which are either enabled, or greatly enhanced, by clever Flow Control. Configurations considered include Channel Wings with circulation control for VTOL (but non-hovering) operation with high cruise speed, strut-braced CTOL transports with wingtip engines and extensive ('natural') laminar flow control, a midwing double fuselage CTOL approach utilizing several synergistic methods for drag-due-to-lift reduction, a supersonic strut-braced configuration with order of twice the L/D of current approaches and a very advanced, highly engine flow-path-integrated hypersonic cruise machine. This paper indicates both the promise of synergistic flow control approaches as enablers for 'Revolutions' in aircraft performance and fluid mechanic 'areas of ignorance' which impede their realization and provide 'target-rich' opportunities for Fluids Research.

  11. Toward a discovery-oriented ethnography in researching the professional context of higher education

    DEFF Research Database (Denmark)

    Friberg, Gustav Torbjörn


    , especially as an inspiration for ethnographic analysis. However, this type of inquiry is problematic, because the Foucauldian perspective contributes to a pre-established idea of social reality, hence distorting essential aspects of the process of discovery. This article aims to provide an alternative...... organizational phenomena. In particular, an analysis based upon Wolf's concept can be useful for an increased understanding of policy processes in the field of higher education....

  12. Making College Worth It: A Review of Research on the Returns to Higher Education


    Philip Oreopoulos; Uros Petronijevic


    Recent stories of soaring student debt levels and under-placed college graduates have caused some to question whether a college education is still a sound investment. In this paper, we review the literature on the returns to higher education in an attempt to determine who benefits from college. Despite the tremendous heterogeneity across potential college students, we conclude that the investment appears to payoff for both the average and marginal student. During the past three decades in par...

  13. An Examination of Drag Reduction Mechanisms in Marine Animals, with Potential Applications to Uninhabited Aerial Vehicles (United States)

    Musick, John A.; Patterson, Mark R.; Dowd, Wesley W.


    Previous engineering research and development has documented the plausibility of applying biomimetic approaches to aerospace engineering. Past cooperation between the Virginia Institute of Marine Science (VIMS) and NASA focused on the drag reduction qualities of the microscale dermal denticles of shark skin. This technology has subsequently been applied to submarines and aircraft. The present study aims to identify and document the three-dimensional geometry of additional macroscale morphologies that potentially confer drag reducing hydrodynamic qualities upon marine animals and which could be applied to enhance the range and endurance of Uninhabited Aerial Vehicles (UAVs). Such morphologies have evolved over eons to maximize organismal energetic efficiency by reducing the energetic input required to maintain cruising speeds in the viscous marine environment. These drag reduction qualities are manifested in several groups of active marine animals commonly encountered by ongoing VIMS research programs: namely sharks, bony fishes such as tunas, and sea turtles. Through spatial data acquired by molding and digital imagery analysis of marine specimens provided by VIMS, NASA aims to construct scale models of these features and to test these potential drag reduction morphologies for application to aircraft design. This report addresses the efforts of VIMS and NASA personnel on this project between January and November 2001.

  14. Research on mutation generation in higher plants with heavy ions at NIRS-HIMAC

    International Nuclear Information System (INIS)

    Okamura, M.; Watanabe, S.; Watanabe, M.; Toguri, T.; Furusawa, Y.


    Plants are closely related to medical treatment in medicine, foods, herbs and medical care by gardening. Ion beams have much higher linear energy transfer (LET) and relative biological effectiveness than those of gamma rays and X-rays. Ion beams are supposed to be useful as new mutagen to obtain novel mutants with superior characteristics in higher plants. In this study, the influence of heavy ions irradiation on bud growth was examined in carnation and the mutation generation was inspected in babies' breath. The growth of carnation buds began to decrease at 10 Gy and the median growth dose was estimated at 35 Gy for 290 Mev/u carbon ion beams. Mutants with petaloid leaves were observed in babies' breath by the irradiation of 290 Mev/u carbon ion beams at 20Gy. We will examine the mutation rates and spectrum for 290 MeV/u carbon, 400 MeV/u neon and 500 MeV/u argon ion beams to find optimum use of the beams in plant breeding. The efficient system to generate useful mutants using heavy ions at NIRS-HIMAC will be developed in higher plants. (author)

  15. Researching the black box of wrItIng processes in higher education

    DEFF Research Database (Denmark)

    Smedegaard Ernst Bengtsen, Søren; Jensen, Gry Sandholm

    Paper Presenter/author: Søren S.E. Bengtsen Title/position: PhD, Research assistant, Centre for Teaching Development and Digital Media, Aarhus University Postal Address: Paludan Müllers-Vej 48, 8200 Aarhus N. E-mail: Co-author: Gry S. Jensen (co-author and co-presenter) Supervisory......, we wish to render visible such student thinking and writing processes. Drawing on phenomenological and linguistic research methods (Manen 2002; Manen 1997; Johnstone 1996) we argue that a new vocabulary for supervision on student texts must be developed for supervisors to more fully grasp...

  16. London 2012 Paralympic swimming: passive drag and the classification system. (United States)

    Oh, Yim-Taek; Burkett, Brendan; Osborough, Conor; Formosa, Danielle; Payton, Carl


    The key difference between the Olympic and Paralympic Games is the use of classification systems within Paralympic sports to provide a fair competition for athletes with a range of physical disabilities. In 2009, the International Paralympic Committee mandated the development of new, evidence-based classification systems. This study aims to assess objectively the swimming classification system by determining the relationship between passive drag and level of swimming-specific impairment, as defined by the current swimming class. Data were collected on participants at the London 2012 Paralympic Games. The passive drag force of 113 swimmers (classes 3-14) was measured using an electro-mechanical towing device and load cell. Swimmers were towed on the surface of a swimming pool at 1.5 m/s while holding their most streamlined position. Passive drag ranged from 24.9 to 82.8 N; the normalised drag (drag/mass) ranged from 0.45 to 1.86 N/kg. Significant negative associations were found between drag and the swimming class (τ = -0.41, p < 0.01) and normalised drag and the swimming class (τ = -0.60, p < 0.01). The mean difference in drag between adjacent classes was inconsistent, ranging from 0 N (6 vs 7) to 11.9 N (5 vs 6). Reciprocal Ponderal Index (a measure of slenderness) correlated moderately with normalised drag (r(P) = -0.40, p < 0.01). Although swimmers with the lowest swimming class experienced the highest passive drag and vice versa, the inconsistent difference in mean passive drag between adjacent classes indicates that the current classification system does not always differentiate clearly between swimming groups.

  17. Research on the Training of Higher Cognitive Learning and Thinking Skills. Final Report. Report No. 5560. (United States)

    Nickerson, R. S.

    The technical reports summarized in this paper were prepared as part of a project designed to determine what is known about the teaching of cognitive skills and to formulate questions relating to such teaching for further research. Topics discussed in the 22 reports include the following: (1) teaching thinking; (2) Aristotle's logic; (3) a…

  18. Antecedents and Consequences of Service Quality in a Higher Education Context: A Qualitative Research Approach (United States)

    Sultan, Parves; Wong, Ho Yin


    Purpose: The purpose of the paper is to report on the perception of students in regard to critical antecedents, dimensions and consequences of service quality with an aim to develop a theoretical model in the context of a university in Australia. Design/methodology/approach: This research used focus group discussions with 19 students who had been…

  19. Past, Present, and Future of Critical Quantitative Research in Higher Education (United States)

    Wells, Ryan S.; Stage, Frances K.


    This chapter discusses the evolution of the critical quantitative paradigm with an emphasis on extending this approach to new populations and new methods. Along with this extension of critical quantitative work, however, come continued challenges and tensions for researchers. This chapter recaps and responds to each chapter in the volume, and…

  20. Student Loan Forbearance and Its Relationship to Default. Synopsis: Higher Education Research Highlights. (United States)

    Price, Derek V.

    As the number and volume of student loans increase nationally, lenders and policymakers look more closely at the use of loan forbearance. This paper examines whether forbearance really cuts the risk of loan default by reporting on a study of more than 9,800 Stafford loans in forbearance in December 1996. That research shows that the default rate…

  1. Innovation, Research and Professional Development in Higher Education: Learning from Our Own Experience (United States)

    Garcia, Leonor Margalef; Roblin, Natalie Pareja


    This paper describes and analyses an innovative experience carried out by a group of lecturers from the Psychopedagogy Faculty of the University of Alcala, involved in an action research process with the purpose of reflecting about our own practice and constructing alternative teaching strategies to facilitate students' reflective, autonomous and…

  2. Models of Learning Space: Integrating Research on Space, Place and Learning in Higher Education (United States)

    Ellis, R. A.; Goodyear, P.


    Learning space research is a relatively new field of study that seeks to inform the design, evaluation and management of learning spaces. This paper reviews a dispersed and fragmented literature relevant to understanding connections between university learning spaces and student learning activities. From this review, the paper distils a number of…

  3. Leveraging Sustainability Reporting in Higher Education Institutions--A Multidimensional Research Agenda (United States)

    Schoormann, Thorsten; Bührig, Jan; Behrens, Dennis; Knackstedt, Ralf


    Sustainability has become increasingly important to research and practice. In order to determine impacts, identify improvement potential and to disclose efforts towards sustainability, an organization needs appropriate reporting. Thus, sustainability reporting has become a topic of broader interest, for example, to assess own situations, enable…

  4. Self-determined shapes and velocities of giant near-zero drag gas cavities

    KAUST Repository

    Vakarelski, Ivan Uriev


    Minimizing the retarding force on a solid moving in liquid is the canonical problem in the quest for energy saving by friction and drag reduction. For an ideal object that cannot sustain any shear stress on its surface, theory predicts that drag force will fall to zero as its speed becomes large. However, experimental verification of this prediction has been challenging. We report the construction of a class of self-determined streamlined structures with this free-slip surface, made up of a teardrop-shaped giant gas cavity that completely encloses a metal sphere. This stable gas cavity is formed around the sphere as it plunges at a sufficiently high speed into the liquid in a deep tank, provided that the sphere is either heated initially to above the Leidenfrost temperature of the liquid or rendered superhydrophobic in water at room temperature. These sphere-in-cavity structures have residual drag coefficients that are typically less than Embedded Image those of solid objects of the same dimensions, which indicates that they experienced very small drag forces. The self-determined shapes of the gas cavities are shown to be consistent with the Bernoulli equation of potential flow applied on the cavity surface. The cavity fall velocity is not arbitrary but is uniquely predicted by the sphere density and cavity volume, so larger cavities have higher characteristic velocities.

  5. The strong thermoelectric effect in nanocarbon generated by the ballistic phonon drag of electrons

    International Nuclear Information System (INIS)

    Eidelman, E D; Vul', A Ya


    The thermoelectric power and thermoelectric figure of merit for carbon nanostructure consisting of graphite-like (sp 2 ) and diamond-like (sp 3 ) regions have been investigated. The probability of electron collisions with quasi-ballistic phonons in sp 2 regions has been analysed for the first time. We have shown that the probability is not small. We have analysed the influence of various factors on the process of the electron-ballistic phonon drag (the phonon drag effect). The thermoelectric power and thermoelectric figure of merit under conditions of ballistic transport were found to be substantially higher than those in the cases of drag by thermalized phonons and of electron diffusion. The thermoelectric figure of merit (ZT) in the case of a ballistic phonon contribution to the phonon drag of electrons should be 50 times that for chaotic phonons and 500 times that in the case of the diffusion process. In that case ZT should be a record (ZT≥2-3)

  6. Effects of cusped field thruster on the performance of drag-free control system (United States)

    Cui, K.; Liu, H.; Jiang, W. J.; Sun, Q. Q.; Hu, P.; Yu, D. R.


    With increased measurement tasks of space science, more requirements for the spacecraft environment have been put forward. Those tasks (e.g. the measurement of Earth's steady state gravity field anomalies) lead to the desire for developing drag-free control. Higher requirements for the thruster performance are made due to the demand for the drag-free control system and real-time compensation for non-conservative forces. Those requirements for the propulsion system include wide continuous throttling ability, high resolution, rapid response, low noise and so on. As a promising candidate, the cusped field thruster has features such as the high working stability, the low erosion rate, a long lifetime and the simple structure, so that it is chosen as the thruster to be discussed in this paper. Firstly, the performance of a new cusped field thruster is tested and analyzed. Then a drag-free control scheme based on the cusped field thruster is designed to evaluate the performance of this thruster. Subsequently, the effects of the thrust resolution, transient response time and thrust uncertainty on the controller are calculated respectively. Finally, the performance of closed-loop system is analyzed, and the simulation results verify the feasibility of applying cusped field thruster to drag-free flight in the space science measurement tasks.

  7. Measurements of long-range enhanced collisional velocity drag through plasma wave damping (United States)

    Affolter, M.; Anderegg, F.; Dubin, D. H. E.; Driscoll, C. F.


    We present damping measurements of axial plasma waves in magnetized, multispecies ion plasmas. At high temperatures T ≳ 10-2 eV, collisionless Landau damping dominates, whereas, at lower temperatures T ≲ 10-2 eV, the damping arises from interspecies collisional drag, which is dependent on the plasma composition and scales roughly as T-3 /2 . This drag damping is proportional to the rate of parallel collisional slowing, and is found to exceed classical predictions of collisional drag damping by as much as an order of magnitude, but agrees with a new collision theory that includes long-range collisions. Centrifugal mass separation and collisional locking of the species occur at ultra-low temperatures T ≲ 10-3 eV, which reduce the drag damping from the T-3 /2 collisional scaling. These mechanisms are investigated by measuring the damping of higher frequency axial modes, and by measuring the damping in plasmas with a non-equilibrium species profile.

  8. Sunspots and the physics of magnetic flux tubes. II. Aerodynamic drag

    International Nuclear Information System (INIS)

    Parker, E.N.


    The aerodynamic drag on a slender flux tube stretched vertically across a convective cell may push the flux tube into the updrafts or into the downdrafts, depending on the density stratification of the convecting fluid and the asymmetry of the fluid motions. The drag is approximately proportional to the local kinetic energy density, so the density stratification weights the drag in favor of the upper layers where the density is low, tending to push the vertical tube into the downdrafts. If, however, the horizontal motions in the convective cell are concentrated toward the bottom of the cell, they may dominate over the upper layers, pushing the tube into the updrafts. In the simple, idealized circumstance of a vertical tube extending across a fluid of uniform density in a convective cell that is symmetric about its midplane, the net aerodynamic drag vanishes in lowest order. The higher order contributions, including the deflection of the tube, then provide a nonvanishing force pushing the tube into a stable equilibrium midway between the updraft and the downdraft.It is pointed out that in the strongly stratified convective zone of the Sun, a downdraft herds flux tubes together into a cluster, while an updraft disperses them. To account for the observed strong cohesion of the cluster of flux tubes that make up a sunspot, we propose a downdraft of the order 2 km s - 1 through the cluster of seprate tubes beneath the sunspot

  9. Arts in Higher Education: an evaluation of Fine Arts research activity in Spain through quality indicators

    Directory of Open Access Journals (Sweden)

    Raquel Caerols Mateo


    Full Text Available The long-standing conflict between research evaluation standards and the fine arts dates from the transformation of the former schools of fine arts into bachelor’s degree programs. The origin of the conflict is epistemological in nature and has consequences at both the academic and curricular level. The quality indicators for evaluating professors are the central issue of this problem still to be solved. Although current systems of evaluation cover both the production of scientific publications as part of traditional research and the artistic creation itself, academics in the fine arts note that deficiencies exist in the assessment of both these aspects.The focus of this paper is primarily on the study of the main national and international databases in the arts, in order to assess their validity as quality indicators for the scholarly output of academics.

  10. Reported credibility techniques in higher education evaluation studies that use qualitative methods: A research synthesis. (United States)

    Liao, Hongjing; Hitchcock, John


    This synthesis study examined the reported use of credibility techniques in higher education evaluation articles that use qualitative methods. The sample included 118 articles published in six leading higher education evaluation journals from 2003 to 2012. Mixed methods approaches were used to identify key credibility techniques reported across the articles, document the frequency of these techniques, and describe their use and properties. Two broad sets of techniques were of interest: primary design techniques (i.e., basic), such as sampling/participant recruitment strategies, data collection methods, analytic details, and additional qualitative credibility techniques (e.g., member checking, negative case analyses, peer debriefing). The majority of evaluation articles reported use of primary techniques although there was wide variation in the amount of supporting detail; most of the articles did not describe the use of additional credibility techniques. This suggests that editors of evaluation journals should encourage the reporting of qualitative design details and authors should develop strategies yielding fuller methodological description. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Does Interdisciplinary Research Lead to Higher Citation Impact? The Different Effect of Proximal and Distal Interdisciplinarity (United States)

    Yegros-Yegros, Alfredo; Rafols, Ismael; D’Este, Pablo


    This article analyses the effect of degree of interdisciplinarity on the citation impact of individual publications for four different scientific fields. We operationalise interdisciplinarity as disciplinary diversity in the references of a publication, and rather than treating interdisciplinarity as a monodimensional property, we investigate the separate effect of different aspects of diversity on citation impact: i.e. variety, balance and disparity. We use a Tobit regression model to examine the effect of these properties of interdisciplinarity on citation impact, controlling for a range of variables associated with the characteristics of publications. We find that variety has a positive effect on impact, whereas balance and disparity have a negative effect. Our results further qualify the separate effect of these three aspects of diversity by pointing out that all three dimensions of interdisciplinarity display a curvilinear (inverted U-shape) relationship with citation impact. These findings can be interpreted in two different ways. On the one hand, they are consistent with the view that, while combining multiple fields has a positive effect in knowledge creation, successful research is better achieved through research efforts that draw on a relatively proximal range of fields, as distal interdisciplinary research might be too risky and more likely to fail. On the other hand, these results may be interpreted as suggesting that scientific audiences are reluctant to cite heterodox papers that mix highly disparate bodies of knowledge—thus giving less credit to publications that are too groundbreaking or challenging. PMID:26266805

  12. Arab Higher Education and Research post–2011. An Interview with Sari Hanafi

    Directory of Open Access Journals (Sweden)

    Achim Rohde


    Full Text Available The upheavals of 2011 and subsequent developments in the MENA region have had substantial effects on universities and research centers within Arab world and in other neighboring countries where similar developments are taking shape (security issues, stricter political control/lesser levels of political control and repression, changing levels of funding, changing focus of donors etc.. META had the opportunity to talk with American University of Beirut’s Prof. Sari Hanafi about the repercussions of these developments for scholarly work within the MENA region. Sari Hanafi is currently a Professor of Sociology and chair of the department of sociology, anthropology and media studies at the American University of Beirut. He is also the editor of Idafat: the Arab Journal of Sociology (Arabic. He is the Vice President of the International Sociological Association (ISA and Vice President of the board of the Arab Council of Social Science. He is the author of numerous journal articles and book chapters on the political and economic sociology of the Palestinian diaspora and refugees; sociology of migration; transnationalism; politics of scientific research; civil society and elite formation and transitional justice. His last book is Arab Research and Knowledge Society: New Critical Perspective (with R. Arvanitis (in Arabic, Beirut: CAUS and forthcoming in English with Routledge.

  13. Academic Formation and Formative Research Integration Management for the Culmination of Studies Process in Higher Education

    Directory of Open Access Journals (Sweden)

    Lorna Cruz Rizo


    Full Text Available Given the up- dated international difficulties in the completion of studies process, theoretical and practical studies developed in this field are surprisingly scarce. Particularly, there has been a limited quantity of students that support their diploma thesis after completing their credits at the School of Languages and Linguistics at the University of Guayaquil. Consequently, this paper faces the problem of the insufficiencies in the culmination of studies process in relation to the management of the academic and scientific formation. Thus, the objective is: to improve the completion of studies or degree- obtaining processes in university education, through the implementation of a praxiological proposal of academic formation and formative research integration. Accordingly, the author´s experiences systematization is the methodology mainly used. The essential logic for the management of the academic formation and formative research integration was revealed as the main proposal, therefore this is the solution to the problem diagnosed. This is based on a curricular structure, in which each of the subjects was interrelated to each of the essential stages of the scientific research. As main results obtained, the students were able to solve real-life problems diagnosed at educative institutions, also they drew up the draft of their theses.

  14. Ontogeny of lift and drag production in ground birds. (United States)

    Heers, Ashley M; Tobalske, Bret W; Dial, Kenneth P


    The juvenile period is often a crucial interval for selective pressure on locomotor ability. Although flight is central to avian biology, little is known about factors that limit flight performance during development. To improve understanding of flight ontogeny, we used a propeller (revolving wing) model to test how wing shape and feather structure influence aerodynamic performance during development in the precocial chukar partridge (Alectoris chukar, 4 to >100 days post hatching). We spun wings in mid-downstroke posture and measured lift (L) and drag (D) using a force plate upon which the propeller assembly was mounted. Our findings demonstrate a clear relationship between feather morphology and aerodynamic performance. Independent of size and velocity, older wings with stiffer and more asymmetrical feathers, high numbers of barbicels and a high degree of overlap between barbules generate greater L and L:D ratios than younger wings with flexible, relatively symmetrical and less cohesive feathers. The gradual transition from immature feathers and drag-based performance to more mature feathers and lift-based performance appears to coincide with ontogenetic transitions in locomotor capacity. Younger birds engage in behaviors that require little aerodynamic force and that allow D to contribute to weight support, whereas older birds may expand their behavioral repertoire by flapping with higher tip velocities and generating greater L. Incipient wings are, therefore, uniquely but immediately functional and provide flight-incapable juveniles with access to three-dimensional environments and refugia. Such access may have conferred selective advantages to theropods with protowings during the evolution of avian flight.

  15. Reynolds number dependence of drag reduction by rodlike polymers

    NARCIS (Netherlands)

    Amarouchene, Y.; Bonn, D.; Kellay, H.; Lo, T.-S.; L'vov, V.S.; Procaccia, I.


    We present experimental and theoretical results addressing the Reynolds number (Re) dependence of drag reduction by sufficiently large concentrations of rodlike polymers in turbulent wall-bounded flows. It is shown that when Re is small the drag is enhanced. On the other hand, when Re increases, the

  16. Determination of the Drag Resistance Coefficients of Different Vehicles (United States)

    Fahsl, Christoph; Vogt, Patrik


    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient "c" of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but…


    Velocity versus coast distance measurements on two monorail rocket sleds were conducted on the Holloman track to obtain numerical information on the...sleds and the drag straps. The straps as described are shown to increase the effective drag area of the monorail sleds used by approximately one square

  18. Spin-transfer mechanism for magnon-drag thermopower

    NARCIS (Netherlands)

    Lucassen, M.E.|info:eu-repo/dai/nl/314406913; Wong, C.H.; Duine, R.A.|info:eu-repo/dai/nl/304830127; Tserkovnyak, Y.


    We point out a relation between the dissipative spin-transfer-torque parameter β and the contribution of magnon drag to the thermoelectric power in conducting ferromagnets. Using this result, we estimate β in iron at low temperatures, where magnon drag is believed to be the dominant contribution to

  19. Frictional drag between quantum wells mediated by phonon exchange

    DEFF Research Database (Denmark)

    Bønsager, M.C.; Flensberg, Karsten; Hu, Ben Yu-Kuang


    We use the Kubo formalism to evaluate the contribution of acoustic-phonon exchange to the frictional drag between nearby two-dimensional electron systems. In the case of free phonons, we find a divergent drag rate (tau(D)(-l)). However, tau(D)(-l) becomes finite when phonon scattering from either...

  20. Just-in-time research: a call to arms for research into mobile technologies in higher education

    Directory of Open Access Journals (Sweden)

    Lucie Byrne-Davis


    Full Text Available Mobile technologies are becoming commonplace in society and in education. In higher education, it is crucial to understand the impact of constant access to information on the development of the knowledge and competence of the learner. This study reports on a series of four surveys completed by UK-based medical students (n=443 who received tablet computers (iPads from their medical school during their 4th year of study. Students were surveyed prior to receiving the iPads and again regarding their usage and experiences at 2, 6 and 12 months post receipt of tablets. Findings indicate that students differed in their use of iPads but that the majority felt that tablets had impacted on their learning and the majority were using them frequently (at least once a day during learning. Almost half of the students reported that clinical supervisors had raised the possibility of tablets changing patient care. These results, although only descriptive, raise important questions about the impact of mobile technologies on learning.

  1. Dancing droplets: Contact angle, drag, and confinement (United States)

    Benusiglio, Adrien; Cira, Nate; Prakash, Manu


    When deposited on a clean glass slide, a mixture of water and propylene glycol forms a droplet of given contact angle, when both pure liquids spread. (Cira, Benusiglio, Prakash: Nature, 2015). The droplet is stabilized by a gradient of surface tension due to evaporation that induces a Marangoni flow from the border to the apex of the droplets. The apparent contact angle of the droplets depends on both their composition and the external humidity as captured by simple models. These droplets present remarkable properties such as lack of a large pinning force. We discuss the drag on these droplets as a function of various parameters. We show theoretical and experimental results of how various confinement geometries change the vapor gradient and the dynamics of droplet attraction.

  2. Analytical Ballistic Trajectories with Approximately Linear Drag

    Directory of Open Access Journals (Sweden)

    Giliam J. P. de Carpentier


    Full Text Available This paper introduces a practical analytical approximation of projectile trajectories in 2D and 3D roughly based on a linear drag model and explores a variety of different planning algorithms for these trajectories. Although the trajectories are only approximate, they still capture many of the characteristics of a real projectile in free fall under the influence of an invariant wind, gravitational pull, and terminal velocity, while the required math for these trajectories and planners is still simple enough to efficiently run on almost all modern hardware devices. Together, these properties make the proposed approach particularly useful for real-time applications where accuracy and performance need to be carefully balanced, such as in computer games.

  3. Does higher income inequality adversely influence infant mortality rates? Reconciling descriptive patterns and recent research findings. (United States)

    Siddiqi, Arjumand; Jones, Marcella K; Erwin, Paul Campbell


    As the struggle continues to explain the relatively high rates of infant mortality (IMR) exhibited in the United States, a renewed emphasis is being placed on the role of possible 'contextual' determinants. Cross-sectional and short time-series studies have found that higher income inequality is associated with higher IMR at the state level. Yet, descriptively, the longer-term trends in income inequality and in IMR seem to call such results into question. To assess whether, over the period 1990-2007, state-level income inequality is associated with state-level IMR; to examine whether the overall effect of income inequality on IMR over this period varies by state; to test whether the association between income inequality and IMR varies across this time period. IMR data--number of deaths per 1000 live births in a given state and year--were obtained from the U.S. Centers for Disease Control Wonder database. Income inequality was measured using the Gini coefficient, which varies from zero (complete equality) to 100 (complete inequality). Covariates included state-level poverty rate, median income, and proportion of high school graduates. Fixed and random effects regressions were conducted to test hypotheses. Fixed effects models suggested that, overall, during the period 1990-2007, income inequality was inversely associated with IMR (β = -0.07, SE (0.01)). Random effects models suggested that when the relationship was allowed to vary at the state-level, it remained inverse (β = -0.05, SE (0.01)). However, an interaction between income inequality and time suggested that, as time increased, the effect of income inequality had an increasingly positive association with total IMR (β = 0.009, SE (0.002)). The influence of state income inequality on IMR is dependent on time, which may proxy for time-dependent aspects of societal context. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Friction and drag forces on spheres propagating down inclined planes (United States)

    Tee, Yi Hui; Longmire, Ellen


    When a submerged sphere propagates along an inclined wall at terminal velocity, it experiences gravity, drag, lift, and friction forces. In the related equations of motion, the drag, lift and friction coefficients are unknown. Experiments are conducted to determine the friction and drag coefficients of the sphere over a range of Reynolds numbers. Through high speed imaging, translational and rotational velocities of spheres propagating along a glass plate are determined in liquids with several viscosities. The onset of sliding motion is identified by computing the dimensionless rotation rate of the sphere. Using drag and lift coefficients for Re friction coefficients are calculated for several materials. The friction coefficients are then employed to estimate the drag coefficient for 350 frictional force over this Re range. Supported by NSF (CBET-1510154).

  5. Airflow in Gravity Sewers - Determination of Wastewater Drag Coefficient. (United States)

    Bentzen, Thomas Ruby; Østertoft, Kristian Kilsgaard; Vollertsen, Jes; Fuglsang, Emil Dietz; Nielsen, Asbjørn Haaning


    Several experiments have been conducted in order to improve the understanding of the wastewater drag and the wall frictional force acting on the headspace air in gravity sewers. The aim of the study is to improve the data basis for a numerical model of natural sewer ventilation. The results of the study shows that by integrating the top/side wall shear stresses the log-law models for the air velocity distribution along the unwetted perimeter resulted in a good agreement with the friction forces calculated by use of the Colebrook-White formula for hydraulic smooth pipes. Secondly, the water surface drags were found by log-law models of the velocity distribution in turbulent flows to fit velocity profiles measured from the water surface and by integrating the water surface drags along the wetted perimeter, mean water surface drags were found and a measure of the water surface drag coefficient was found.

  6. Electron drag in ferromagnetic structures separated by an insulating interface (United States)

    Kozub, V. I.; Muradov, M. I.; Galperin, Y. M.


    We consider electron drag in a system of two ferromagnetic layers separated by an insulating interface. The source of it is expected to be magnon-electron interactions. Namely, we assume that the external voltage is applied to the "active" layer stimulating electric current through this layer. In its turn, the scattering of the current-carrying electrons by magnons leads to a magnon drag current within this layer. The 3-magnons interactions between magnons in the two layers (being of non-local nature) lead to magnon drag within the "passive" layer which, correspondingly, produce electron drag current via processes of magnon-electron scattering. We estimate the drag current and compare it to the phonon-induced one.

  7. Drag Measurements over Embedded Cavities in a Low Reynolds Number Couette Flow (United States)

    Gilmer, Caleb; Lang, Amy; Jones, Robert


    Recent research has revealed that thin-walled, embedded cavities in low Reynolds number flow have the potential to reduce the net viscous drag force acting on the surface. This reduction is due to the formation of embedded vortices allowing the outer flow to pass over the surface via a roller bearing effect. It is also hypothesized that the scales found on butterfly wings may act in a similar manner to cause a net increase in flying efficiency. In this experimental study, rectangular embedded cavities were designed as a means of successfully reducing the net drag across surfaces in a low Reynolds number flow. A Couette flow was generated via a rotating conveyor belt immersed in a tank of high viscosity mineral oil above which the plates with embedded cavities were placed. Drag induced on the plate models was measured using a force gauge and compared directly to measurements acquired over a flat plate. Various cavity aspect ratios and gap heights were tested in order to determine the conditions under which the greatest drag reductions occurred.

  8. Phonon Drag in Thin Films, Cases of Bi2Te3 and ZnTe (United States)

    Chi, Hang; Uher, Ctirad


    At low temperatures, in (semi-)conductors subjected to a thermal gradient, charge carriers (electrons and holes) are swept (dragged) by out-of-equilibrium phonons due to strong electron-phonon interaction, giving rise to a large contribution to the Seebeck coefficient called the phonon-drag effect. Such phenomenon was surprisingly observed in our recent transport study of highly mismatched alloys as potential thermoelectric materials: a significant phonon-drag thermopower reaching 1.5-2.5 mV/K was recorded for the first time in nitrogen-doped ZnTe epitaxial layers on GaAs (100). In thin films of Bi2Te3, we demonstrate a spectacular influence of substrate phonons on charge carriers. We show that one can control and tune the position and magnitude of the phonon-drag peak over a wide range of temperatures by depositing thin films on substrates with vastly different Debye temperatures. Our experiments also provide a way to study the nature of the phonon spectrum in thin films, which is rarely probed but clearly important for a complete understanding of thin film properties and the interplay of the substrate and films. This work is supported by the Center for Solar and Thermal Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0000957.

  9. Gain-assisted superluminal propagation and rotary drag of photon and surface plasmon polaritons (United States)

    Khan, Naveed; Amin Bacha, Bakht; Iqbal, Azmat; Ur Rahman, Amin; Afaq, A.


    Superluminal propagation of light is a well-established phenomenon and has motivated immense research interest that has led to state-of-the-art knowledge and potential applications in the emerging technology of quantum optics and photonics. This study presents a theoretical analysis of the gain-assisted superluminal light propagation in a four-level N -type atomic system by exploiting the scheme of electromagnetically induced gain and superluminal propagation of surface plasmon polaritons (SPPs) along the gain-assisted atomic-metal interface simultaneously. In addition, a theoretical demonstration is presented on the comparison between Fresnel's rotary photon drag and SPP drag in view of light polarization state rotation by rotating the coherent atomic medium and the atomic-metal interface, respectively. Analogous to photon drag in the superluminal anomalous dispersion region where light polarization rotation occurs opposite the rotation of the gain-assisted atomic medium, the rotation of the atomic-metal interface also rotates the polarization state of SPPs opposite the rotation of the interface. This further confirms the superluminal nature of SPPs propagating along the interface with negative group velocity. Rabi frequencies of the control and pump fields considerably modify both photon and SPP drag coefficients. Metal conductivity also controls SPP propagation.

  10. The Effects of Propulsive Jetting on Drag of a Streamlined body (United States)

    Krieg, Michael; Mohseni, Kamran


    Recently an abundance of bioinspired underwater vehicles have emerged to leverage eons of evolution. Our group has developed a propulsion technique inspired by jellyfish and squid. Propulsive jets are generated by ingesting and expelling water from a flexible internal cavity. We have demonstrated thruster capabilities for maneuvering on AUV platforms, where the internal thruster geometry minimized forward drag; however, such a setup cannot characterize propulsive efficiency. Therefore, we created a new streamlined vehicle platform that produces unsteady jets for forward propulsion rather than maneuvering. The streamlined jetting body is placed in a water tunnel and held stationary while jetting frequency and background flow velocity are varied. For each frequency/velocity pair the flow field is measured around the surface and in the wake using PIV. Using the zero jetting frequency as a baseline for each background velocity, the passive body drag is related to the velocity distribution. For cases with active jetting the drag and jetting forces are estimated from the velocity field and compared to the passive case. For this streamlined body, the entrainment of surrounding flow into the propulsive jet can reduce drag forces in addition to the momentum transfer of the jet itself. Office of Naval Research.

  11. Transnational Higher Education Partnerships and the Role of Operational Faculty Members: Developing an Alternative Theoretical Approach for Empirical Research (United States)

    Bordogna, Claudia M.


    For too long, transnational higher education (TNE) has been linked to discourse predominately focused upon strategic implementation, quality assurance, and pedagogy. While these aspects are important when designing and managing overseas provisions, there is a lack of research focusing on the social interactions that influence the pace and…

  12. Chasing a Moving Target: Perceptions of Work Readiness and Graduate Capabilities in Music Higher Research Degree Students (United States)

    Harrison, Scott; Grant, Catherine


    Recent efforts to increase workplace readiness in university students have largely centred on undergraduates, with comparatively few strategies or studies focusing on higher research degree candidates. In the discipline of music, a wide diversity of possible career paths combined with rapidly changing career opportunities makes workplace readiness…

  13. Memoir as a Form of Auto-Ethnographic Research for Exploring the Practice of Transnational Higher Education in China (United States)

    Scott, Joy Denise


    In this paper, I argue that memoir, as a form of auto-ethnographic research, is an appropriate method for exploring the complexities and singularities in the practice of western educational practitioners who are immersed in the social reality of offshore higher education institutions, such as those in Mainland China. I illustrate this proposition…

  14. What Do We Know about Glass Ceiling Effects? A Taxonomy and Critical Review to Inform Higher Education Research (United States)

    Jackson, Jerlando F. L.; O'Callaghan, Elizabeth M.


    The concept of "glass ceiling effects" has emerged in social science research in general and higher education in particular over the past 20 years. These studies have described the impediments that women and people of color encounter in their quest for senior-level positions (e.g., CEOs) in society as glass ceiling effects. Literature, both…

  15. The Impact of Learning about Technology via Action Research as a Professional Development Activity on Higher Education: A Case Study (United States)

    Premdas, Leisa


    The purpose of this mixed method study was to determine the perceived impact of learning about technology via action research as a professional development activity on faculty and students in higher education. Nine faculty members--also Teaching and Technology Fellows representing various disciplines at St. John's University--were selected based…

  16. La eficacia del efecto látigo en el drag flick en el hockey hierba The effectiveness of the bullwhip effect in the Drag-flick in field hockey

    Directory of Open Access Journals (Sweden)

    C. López de Subijana


    Full Text Available

    El penalty córner es una de las jugadas más importantes en el hockey hierba. El drag-flick es la técnica de golpeo más eficaz en las jugadas de penalty córner (McLaughin, 1997. Los objetivos del presente estudio fueron el describir los parámetros cinemáticos del drag-flick en jugadores de nivel internacional y analizar las diferencias intergénero. La muestra fueron trece sujetos, un modelo, seis hombres y seis mujeres. El sistema de captura automático VICON registró 20 lanzamientos de cada jugador con una frecuencia de muestreo de 250 Hz. Las velocidades máximas angulares de las caderas, hombros y stick  fueron superiores  (p<0.01 en el modelo que en ambos grupos de género. Mediante la comparación estadística del modelo con ambos grupos de género se han podido determinar las claves de este gesto técnico, siendo necesario un movimiento hacia atrás del stick (efecto látigo antes de la aceleración de caderas y hombros, para terminar el gesto con la máxima aceleración del stick.
    Palabras Clave: Biomecánica, drag-flick, hockey hierba, cinemática

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is more efficient than other techniques when playing a penalty corner. The aims of this study were to describe the kinematics of international field hockey players during the drag-flick and to analyse gender differences. Thirteen participants, one male drag-flicker, six males and six females participated in the study. VICON optoelectronic system measured the kinematic parameters from the drag-flick with six cameras sampling at 250 Hz. Twenty trials were captured from each subject. Ball velocity at release, hips maximum angular velocity, stick minimum and maximum angular velocities were higher (p<0.01 in the drag-flicker than in both gender groups. Comparing with the drag-flicker we have found the cues of the skill, being necessary a


    Directory of Open Access Journals (Sweden)

    Celal Karaca


    Full Text Available The purpose of this study is to determine the effect of the flipped learning method on the cognitive load of the students. The study was conducted with a sample of 160 people who were trained in Department of Mechanical Engineering for algorithms and programming courses at a higher education level. The study, which lasted for 8 weeks, has a semi-experimental design. A 9-point scale developed by Paas and Van Merrienboer (1993 was used for cognitive load measurements. At the end of the weekly courses, the scale was filled by the experimental and control groups. Independent sample t test was applied through SPSS 24 program to the obtained data. In both instances, the cognitive load in the experimental group in which the flipped learning method was applied was found to be lower than the cognitive load in the control group in which traditional face-to-face training was applied. As a result, it can be said that flipped learning, if well structured, is a method reducing cognitive load.

  18. Related research on corneal higher-order aberrations after different ways refractive surgery

    Directory of Open Access Journals (Sweden)

    Shu-Xi He


    Full Text Available AIM:To evaluate the changes of corneal high-order aberration(including Coma, Spab, RMShafter laser in situ keratomileusis(LASIKwith femtosecond laser, sub-Bowman keratomileusis(SBKand laser epithelial keratomileusis(LASEK.METHODS: Of 82 myopic patients(164 eyes, 31 patients(62 eyeswere treated by FS-LASIK, 31 patients(62 eyeswere treated by SBK, 20 patients(40 eyeswere treated by LASEK. Sirius system was used for measuring the coma aberration, spherical aberration, and high order aberration at 1, 15d,1, 3mo after surgery.RESULTS: 1Vision: The uncorrected visual acuity of the three groups had no differences(P>0.05. 2Corneal aberrations: Three kinds of surgical procedure for patients with corneal aberration had significant impact. The C7, C8, C12 and RMSh of three groups were increased significantly(P0.05. The C7, C8, C12 and RMSh were not recovered to preoperative levels after 3mo. But the increase of patients after FS-LASIK was smaller than the other two groups, with statistical significance(P0.05.CONCLUSION: Compared with SBK and LASEK,FS-LASIK has better visual acuity in the early postoperative and corneal higher-order aberrations increase is relatively small.

  19. Bubble-induced skin-friction drag reduction and the abrupt transition to air-layer drag reduction (United States)

    Elbing, Brian R.; Winkel, Eric S.; Lay, Keary A.; Ceccio, Steven L.; Dowling, David R.; Perlin, Marc

    To investigate the phenomena of skin-friction drag reduction in a turbulent boundary layer (TBL) at large scales and high Reynolds numbers, a set of experiments has been conducted at the US Navy's William B. Morgan Large Cavitation Channel (LCC). Drag reduction was achieved by injecting gas (air) from a line source through the wall of a nearly zero-pressure-gradient TBL that formed on a flat-plate test model that was either hydraulically smooth or fully rough. Two distinct drag-reduction phenomena were investigated; bubble drag reduction (BDR) and air-layer drag reduction (ALDR).The streamwise distribution of skin-friction drag reduction was monitored with six skin-friction balances at downstream-distance-based Reynolds numbers to 220 million and at test speeds to 20.0msinitial zone1. These results indicated that there are three distinct regions associated with drag reduction with air injection: Region I, BDR; Region II, transition between BDR and ALDR; and Region III, ALDR. In addition, once ALDR was established: friction drag reduction in excess of 80% was observed over the entire smooth model for speeds to 15.3ms1 with the surface fully roughened (though approximately 50% greater volumetric air flux was required); and ALDR was sensitive to the inflow conditions. The sensitivity to the inflow conditions can be mitigated by employing a small faired step (10mm height in the experiment) that helps to create a fixed separation line.


    Directory of Open Access Journals (Sweden)

    J. G. Chagas


    Full Text Available The technological breakthrough noticed in the past few years, promoted an increase of the knowledge production within the use of the internet leading the population to the easy access to the information. Therefore, the control of quality of the information given in the internet is not able to check the all the information in it, which demands the users an extra expertise. This research has the aim to test the contents of the Biochemistry shown in the WEB sites simulating the way students search the internet about Bio subjects. About the sites studied (20, none of them was considered excellent, taking into consideration, confiability, adaptation from Carneiro and Henrique (2009, like: quality of information, objectivity, present time references and media resources. In the concern of accuracy of the information, many mistakes were detected, like: phospholipids, glycolipids found in the cell walls of human beings, fatty acids are straight chain of hydrocarbon ending in a carboxyl group and in a metil group in another extremety, the glycerolis a carbohydrates of three carbons, concerning those mistakes, teachers and students must be aware of advantages and disadvantages that internet can bring to the teaching learning process and together they can stabblish necessary aims so that favorable proposals don’t become anti productive to the process.

  1. Drag reduction and thrust generation by tangential surface motion in flow past a cylinder (United States)

    Mao, Xuerui; Pearson, Emily


    Sensitivity of drag to tangential surface motion is calculated in flow past a circular cylinder in both two- and three-dimensional conditions at Reynolds number Re ≤ 1000 . The magnitude of the sensitivity maximises in the region slightly upstream of the separation points where the contour lines of spanwise vorticity are normal to the cylinder surface. A control to reduce drag can be obtained by (negatively) scaling the sensitivity. The high correlation of sensitivities of controlled and uncontrolled flow indicates that the scaled sensitivity is a good approximation of the nonlinear optimal control. It is validated through direct numerical simulations that the linear range of the steady control is much higher than the unsteady control, which synchronises the vortex shedding and induces lock-in effects. The steady control injects angular momentum into the separating boundary layer, stabilises the flow and increases the base pressure significantly. At Re=100 , when the maximum tangential motion reaches 50% of the free-stream velocity, the vortex shedding, boundary-layer separation and recirculation bubbles are eliminated and 32% of the drag is reduced. When the maximum tangential motion reaches 2.5 times of the free-stream velocity, thrust is generated and the power savings ratio, defined as the ratio of the reduced drag power to the control input power, reaches 19.6. The mechanism of drag reduction is attributed to the change of the radial gradient of spanwise vorticity (partial r \\hat{ζ } ) and the subsequent accelerated pressure recovery from the uncontrolled separation points to the rear stagnation point.

  2. Oxygen ion uplift and satellite drag effects during the 30 October 2003 daytime superfountain event

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani


    Full Text Available The prompt penetration of interplanetary electric fields (IEFs to the dayside low-latitude ionosphere during the first ~2 h of a superstorm is estimated and applied to a modified NRL SAMI2 code for the 30 October 2003 event. In our simulations, the dayside ionospheric O+ is convected to higher altitudes (~600 km and higher latitudes (~±25° to 30°, forming highly displaced equatorial ionospheric anomaly (EIA peaks. This feature plus others are consistent with previously published CHAMP electron (TEC measurements and with the dayside superfountain model. The rapid upward motion of the O+ ions causes neutral oxygen (O uplift due to ion-neutral drag. It is estimated that above ~400 km altitude the O densities within the displaced EIAs can be increased substantially over quiet time values. The latter feature will cause increased drag for low-altitude satellites. This newly predicted phenomenon is expected to be typical for superstorm/IEF events.

  3. Social sciences, scientific research, higher education and social developments - An Albanian inside of dialectics and structured scientific research, in social sciences

    Directory of Open Access Journals (Sweden)

    Nada Kallçiu


    At first this will involve the policy makers at the central level, like the Ministry of Education and Sciences and the main research actors in the public and in the private sector. The criteria of the geographical and the subjects coverage has been also used in order to be able to present a public institutions of the higher education and research but even the enterprises that act in the research area are mainly focusing to the integration of these two systems which have been working separately for a long period of time and that must become efficient in order to adapt to the conditions of a country that has limited financial resources. This article is intended to provide a comprehensive overview of the scientific research in Albania, focusing in defining the priority areas for the research in social sciences. The information about the higher education and the potential problems that it faces, is based on a big number of research institutions, selected based on their involvement in scientific research in social sciences. This article brings into evidence the fact that in order to establish a stable and effective infrastructure in scientific research in Albania, is important to work in different directions. A successful way to increase the efficasity through the elements of the “innovative system” is by working with organizations that work in specific sectors of the economy, aiming for a possible cooperation in scientific search, for an important social contribution.

  4. Drag reduction statistics in a channel flow

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Bernal, Jose A. [Instituto Politecnico Nacional, LABINTHAP-SEPI-ESIME, Edif. 5, 3er piso Col. Lindavista, Mexico DF 07738 (Mexico); Hassan, Yassin A.; Gutierrez-Torres, Claudia del C. [Nuclear Engineering Department, Texas A and M University, College Station, TX 77843-3123 (United States)


    Full text of publication follows: Methods to reduce the drag have been studied for many years because of the promising payoffs that can be attained. In this investigation, the evaluation of statistics such as skewness, flatness, spectra of the stream-wise velocity fluctuations is performed for single phase flow and for two phase flow. Micro-bubbles with an average diameter of 30 {mu}m and a local void fraction of 4.8 % were produced by electrolysis and injected inside the boundary layer. This value of void fraction produced a 38.45 % decrease of the drag. The experiments were conducted in a channel flow at a Reynolds number Re 5128 (considering half height of the channel, the bulk velocity and the kinematics viscosity of the water). The channel was made of acrylic due to the optical properties of this material; its dimensions are 3.85 m long, 0.206 m wide and 0.056 m high. A pressure transducer that ranges from 0 to 35 Pa is located in the test station to measure the pressure drop in single phase flow; this pressure value is used to calculate the shear wall stress. The shear wall stress of two phase flow was measured from the velocity fields obtained from Particle Image Velocimetry (PIV) technique. PIV was utilized to measure instantaneous velocity fields in the stream-wise-normal (x-y) plane. The use of low-local values of void fraction caused a reduction of undesirable speckles effects and an absence of extreme brightness provoked by high bubble saturation. The measurements were carried out in the upper wall of the channel at 3.15 m downstream the inlet's channel. The PIV system is formed by a CCD camera with a resolution of 1008 x 1018 pixels and a double pulse laser with a maximum power 400 mJ and a wavelength of 532 nm (green light). The laser beam was transformed into a sheet of light by an array of cylindrical lenses. Two hundred frames with an area of 1.28 cm{sup 2} were recorded to obtain one hundred velocity fields. The time separation between

  5. Drag reduction statistics in a channel flow

    International Nuclear Information System (INIS)

    Jimenez-Bernal, Jose A.; Hassan, Yassin A.; Gutierrez-Torres, Claudia del C.


    Full text of publication follows: Methods to reduce the drag have been studied for many years because of the promising payoffs that can be attained. In this investigation, the evaluation of statistics such as skewness, flatness, spectra of the stream-wise velocity fluctuations is performed for single phase flow and for two phase flow. Micro-bubbles with an average diameter of 30 μm and a local void fraction of 4.8 % were produced by electrolysis and injected inside the boundary layer. This value of void fraction produced a 38.45 % decrease of the drag. The experiments were conducted in a channel flow at a Reynolds number Re 5128 (considering half height of the channel, the bulk velocity and the kinematics viscosity of the water). The channel was made of acrylic due to the optical properties of this material; its dimensions are 3.85 m long, 0.206 m wide and 0.056 m high. A pressure transducer that ranges from 0 to 35 Pa is located in the test station to measure the pressure drop in single phase flow; this pressure value is used to calculate the shear wall stress. The shear wall stress of two phase flow was measured from the velocity fields obtained from Particle Image Velocimetry (PIV) technique. PIV was utilized to measure instantaneous velocity fields in the stream-wise-normal (x-y) plane. The use of low-local values of void fraction caused a reduction of undesirable speckles effects and an absence of extreme brightness provoked by high bubble saturation. The measurements were carried out in the upper wall of the channel at 3.15 m downstream the inlet's channel. The PIV system is formed by a CCD camera with a resolution of 1008 x 1018 pixels and a double pulse laser with a maximum power 400 mJ and a wavelength of 532 nm (green light). The laser beam was transformed into a sheet of light by an array of cylindrical lenses. Two hundred frames with an area of 1.28 cm 2 were recorded to obtain one hundred velocity fields. The time separation between consecutive pulses

  6. Drag of ballistic electrons by an ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, V. L.; Muradov, M. I., E-mail: [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)


    Drag of electrons of a one-dimensional ballistic nanowire by a nearby one-dimensional beam of ions is considered. We assume that the ion beam is represented by an ensemble of heavy ions of the same velocity V. The ratio of the drag current to the primary current carried by the ion beam is calculated. The drag current turns out to be a nonmonotonic function of velocity V. It has a sharp maximum for V near v{sub nF}/2, where n is the number of the uppermost electron miniband (channel) taking part in conduction and v{sub nF} is the corresponding Fermi velocity. This means that the phenomenon of ion beam drag can be used for investigation of the electron spectra of ballistic nanostructures. We note that whereas observation of the Coulomb drag between two parallel quantum wires may in general be complicated by phenomena such as tunneling and phonon drag, the Coulomb drag of electrons of a one-dimensional ballistic nanowire by an ion beam is free of such spurious effects.

  7. Search for a solute-drag effect in dendritic solidification

    International Nuclear Information System (INIS)

    Eckler, K.; Herlach, D.M.; Aziz, M.J.


    The authors report the results of an indirect experimental test for the solute-drag effect in alloy solidification by fitting the data of Eckler for Ni-B dendrite tip velocities vs undercooling to models in several ways. The unknown equilibrium partition coefficient, k e , was varied as a fitting parameter. When they combine the dendrite growth model of Boettinger et al. with the Continuous Growth Model (CGM) of Aziz and Kaplan with solute drag, they cannot fit the data for any value of k e . When they combine dendrite growth theory with the CGM without solute drag, they obtain a reasonable fit to the data for k e = 4 x 10 -6 . When they combine dendrite growth theory with a new partial-solute-drag interpolation between the with-solute-drag and the without-solute-drag versions of the CGM, they obtain a still better fit to the data for k e = 2.8 x 10 - 4. This result points out the possibility of partial solute-drag during solidification and the importance of an independent determination of k e in order to distinguish between models

  8. Drag of Clean and Fouled Net Panels--Measurements and Parameterization of Fouling.

    Directory of Open Access Journals (Sweden)

    Lars Christian Gansel

    Full Text Available Biofouling is a serious problem in marine aquaculture and it has a number of negative impacts including increased forces on aquaculture structures and reduced water exchange across nets. This in turn affects the behavior of fish cages in waves and currents and has an impact on the water volume and quality inside net pens. Even though these negative effects are acknowledged by the research community and governmental institutions, there is limited knowledge about fouling related effects on the flow past nets, and more detailed investigations distinguishing between different fouling types have been called for. This study evaluates the effect of hydroids, an important fouling organism in Norwegian aquaculture, on the forces acting on net panels. Drag forces on clean and fouled nets were measured in a flume tank, and net solidity including effect of fouling were determined using image analysis. The relationship between net solidity and drag was assessed, and it was found that a solidity increase due to hydroids caused less additional drag than a similar increase caused by change in clean net parameters. For solidities tested in this study, the difference in drag force increase could be as high as 43% between fouled and clean nets with same solidity. The relationship between solidity and drag force is well described by exponential functions for clean as well as for fouled nets. A method is proposed to parameterize the effect of fouling in terms of an increase in net solidity. This allows existing numerical methods developed for clean nets to be used to model the effects of biofouling on nets. Measurements with other types of fouling can be added to build a database on effects of the accumulation of different fouling organisms on aquaculture nets.

  9. Modeling Evidence-Based Application: Using Team-Based Learning to Increase Higher Order Thinking in Nursing Research

    Directory of Open Access Journals (Sweden)

    Bridget Moore


    Full Text Available Nursing practice is comprised of knowledge, theory, and research [1]. Because of its impact on the profession, the appraisal of research evidence is critically important. Future nursing professionals must be introduced to the purpose and utility of nursing research, as early exposure provides an opportunity to embed evidence-based practice (EBP into clinical experiences. The AACN requires baccalaureate education to include an understanding of the research process to integrate reliable evidence to inform practice and enhance clinical judgments [1]. Although the importance of these knowledge competencies are evident to healthcare administrators and nursing leaders within the field, undergraduate students at the institution under study sometimes have difficulty understanding the relevance of nursing research to the baccalaureate prepared nurse, and struggle to grasp advanced concepts of qualitative and quantitative research design and methodologies. As undergraduate nursing students generally have not demonstrated an understanding of the relationship between theoretical concepts found within the undergraduate nursing curriculum and the practical application of these concepts in the clinical setting, the research team decided to adopt an effective pedagogical active learning strategy, team-based learning (TBL. Team-based learning shifts the traditional course design to focus on higher thinking skills to integrate desired knowledge [2]. The purpose of this paper is to discuss the impact of course design with the integration of TBL in an undergraduate nursing research course on increasing higher order thinking. [1] American Association of Colleges of Nursing, The Essentials of Baccalaureate Education for Professional Nursing Practice, Washington, DC: American Association of Colleges of Nursing, 2008. [2] B. Bloom, Taxonomy of Educational Objectives, Handbook I: Cognitive Domain, New York: McKay, 1956.

  10. Road to the Future. General Aspects of Brazilian Higher Education and a Brief Comparison with Other Educational Modes. Yale Higher Education Research Group Working Paper. (United States)

    Simao, Jose Veiga

    After a brief explanation of the economic and social background of Brazil, its educational system is described and the prospects for higher education there are explored. Like most nations, Brazil's higher education system is unique and adapted to its own needs. Its system bears similarities to both European and American traditions. In the near…

  11. Bilateral macular colobomata: Temporal dragging of optic disc

    Directory of Open Access Journals (Sweden)

    David J Mathew


    Full Text Available A 13-year-old male presented with decreased vision and squint from childhood. He had bilateral large colobomata at the macula in each eye, the one on the right being larger than the left. The disc was dragged temporally with straightening of the temporal retinal vessels. This is a case report of bilateral large macular coloboma and serves to report its association with a temporally dragged disc and straightened temporal retinal vessels. A dragged disc if present with a colobomatous defect at the macula may strengthen the case for diagnosis of macular coloboma and help exclude other differentials.

  12. Oscillating Sign of Drag in High Landau Levels

    International Nuclear Information System (INIS)

    von Oppen, Felix; Simon, Steven H.; Stern, Ady


    Motivated by experiments, we study the sign of the Coulomb drag voltage in a double layer system in a strong magnetic field. We show that the commonly used Fermi golden rule approach implicitly assumes a linear dependence of intralayer conductivity on density, and is thus inadequate in strong magnetic fields. Going beyond this approach, we show that the drag voltage commonly changes sign with density difference between the layers. We find that, in the quantum Hall regime, the Hall and longitudinal drag resistivities may be comparable. Our results are also relevant for pumping and acoustoelectric experiments

  13. Effect of guideway discontinuities on magnetic levitation and drag forces

    International Nuclear Information System (INIS)

    Rossing, T.D.; Korte, R.; Hull, J.R.


    Transients in the lift and drag forces on a NdFeB permanent magnet were observed as the magnet passed over various discontinuities in a rotating aluminum disk at velocities of 4 to 25 m/s. For full cuts in the disk, the amplitude of the lift and drag transients and the wave form of the drag transient depend on the width, and the amplitudes are much larger than for partial cuts. The use of a backing plate to join two cut segments is ineffective

  14. A Low Cost Inflatable CubeSat Drag Brake Utilizing Sublimation (United States)

    Horn, Adam Charles

    The United Nations Inter-Agency Debris Coordination Committee has adopted a 25-year post-mission lifetime requirement for any satellite orbiting below 2000 km in order to mitigate the growing orbital debris threat. Low-cost CubeSats have become important satellite platforms with startling capabilities, but this guideline restricts them to altitudes below 600 km because they remain in orbit too long. In order to enable CubeSat deployments at higher release altitudes, a low-cost, ultra-reliable deorbit device is needed. This thesis reports on efforts to develop a deployable and passively inflatable drag brake that can deorbit from higher orbital altitudes, thereby complying with the 25-year orbital lifetime guideline. On the basis of concepts first implemented during the NASA Echo Satellite Project, this study investigated the design of an inflatable CubeSat drag device that utilizes sublimating benzoic acid powder as the inflation propellant. Testing has focused on demonstrating the functionality of charging a Mylar drag brake bladder with appropriate quantities of benzoic acid powder, and the exposure to a controlled-temperature vacuum chamber causing the bladder to inflate. Although results show a measureable increase in internal pressure when introduced to anticipated orbital temperatures, a significant air-derived expansion prior to sublimation was encountered due to the undetectable volume of ambient residual air in the fabricated membrane bladders. These tests have demonstrated the feasibility of this approach, thereby demonstrating that this concept can create a potentially smaller and less expensive drag device, eliminating inflation gas tanks and valves. In that way, this system can provide a low-cost, miniaturized system that reduces a CubeSat's orbital lifetime to less than 25 years, when placed at higher orbital altitude.

  15. Drag of a Supercritical Body of Revolution in Free Flight at Transonic Speeds and Comparison with Wind Tunnel Data (United States)

    Usry, J. W.; Wallace, J. W.


    The forebody drag of a supercritical body of revolution was measured in free flight over a Mach number range of 0.85 to 1.05 and a Reynolds number range of 11.5 x 10 to the 6th power to 19.4 x 10 to the 6th power and was compared with wind-tunnel data. The forebody drag coefficient for a Mach number less than 0.96 was 0.111 compared with the wind-tunnel value of 0.103. A gradual increase in the drag occurred in the Langley 8-foot transonic pressure tunnel at a lower Mach number than in the Langley 16-foot transonic tunnel or in the free-flight test. The sharp drag rise occurred near Mach 0.98 in free flight whereas the rise occurred near Mach 0.99 in the Langley 16-foot transonic tunnel. The sharp rise was not as pronounced in the Langley 8-foot transonic pressure tunnel and was probably affected by tunnel-wall-interference effects. The increase occurred more slowly and at a higher Mach number. These results indicate that the drag measurements made in the wind tunnels near Mach 1 were significantly affected by the relative size of the model and the wind tunnel.

  16. Drag Reduction through Pulsed Plasma Actuators, Phase I (United States)

    National Aeronautics and Space Administration — Drag reduction is a fundamental necessity in all aerodynamic designs, as it directly affects aircraft fuel efficiency which in turn affects endurance, range, and...

  17. Influence of Surface Roughness on Polymer Drag Reduction

    National Research Council Canada - National Science Library

    Ceccio, Steven L; Dowling, David R; Perlin, Marc; Solomon, Michael


    .... The details of that effort can be found in the final technical report for that project. The purpose of the additional investigation was to examine the physics and engineering of friction drag reduction methods for turbulent boundary layers (TBL...

  18. Drag force and jet propulsion investigation of a swimming squid

    Directory of Open Access Journals (Sweden)

    Tabatabaei Mahdi


    Full Text Available In this study, CAD model of a squid was obtained by taking computer tomography images of a real squid. The model later placed into a computational domain to calculate drag force and performance of jet propulsion. The drag study was performed on the CAD model so that drag force subjected to real squid was revealed at squid’s different swimming speeds and comparison has been made with other underwater creatures (e.g., a dolphin, sea lion and penguin. The drag coefficient (referenced to total wetted surface area of squid is 0.0042 at Reynolds number 1.6x106 that is a %4.5 difference from Gentoo penguin. Besides, jet flow of squid was simulated to observe the flow region generated in the 2D domain utilizing dynamic mesh method to mimic the movement of squid’s mantle cavity.

  19. Experimental study of drag reduction in flumes and spillway tunnels

    Directory of Open Access Journals (Sweden)

    Ying-kui Wang


    Full Text Available Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments: polymer addition and coating. The drag reduction effect of a polyacrylamide (PAM solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carried out with a model of the Xiluodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

  20. Wall temperature control of low-speed body drag (United States)

    Lin, J. C.; Ash, R. L.


    The use of thermal means to control drag under turbulent boundary layer conditions is examined. Numerical calculations are presented for both skin friction and (unseparated) pressure drag for turbulent boundary-layer flows over a fuselage-like body with wall heat transfer. In addition, thermal control of separation on a bluff body is investigated. It is shown that a total drag reduction of up to 20 percent can be achieved for wall heating with a wall-to-total-freestream temperature ratio of 2. For streamlined slender bodies, partial wall heating of the forebody can produce almost the same order of total drag reduction as the full body heating case. For bluff bodies, the separation delay from partial wall cooling of the afterbody is approximately the same as for the fully cooled body.


    Directory of Open Access Journals (Sweden)

    Zbigniew Czyż


    Full Text Available The paper presents the experimental investigation of the impact of velocity on drag force in the autogyro model. One of the methods which simulate motion of the flying object consists of using a wind tunnel. In this case, test object is stationary and the motion of air is forced by e.g. a special fan. The costs related with renting and the wind tunnel service are still very high. In this paper, the motion of the autogyro with respect to the air, was produced by fixing this model with scale to measure the drag force on the passenger car roof. The position of the object relative to the vehicle was checked on the basis of numerical analysis of the airflow around this vehicle. Based on the investigations, the field of velocity and pressure, and air flow formed around the contour of the vehicle which have been chosen, were determined. In addition, the drag force characteristic was determined as a function of velocity and it was compared with the values from the numerical analysis. This research is a form of verifying opportunities for this type of research on vehicles. The conclusions derived from the analysis of the results will be used in the future to carry out further research.

  2. Atomistically informed solute drag in Al–Mg

    International Nuclear Information System (INIS)

    Zhang, F; Curtin, W A


    Solute drag in solute-strengthened alloys, caused by diffusion of solute atoms around moving dislocations, controls the stress at deformation rates and temperatures useful for plastic forming processes. In the technologically important Al–Mg alloys, the solute drag stresses predicted by classical theories are much larger than experiments, which is resolved in general by eliminating the singularity of the dislocation core via Peierls–Nabarro-type models. Here, the drag stress versus dislocation velocity is computed numerically using a realistic dislocation core structure obtained from an atomistic model to investigate the role of the core and obtain quantitative stresses for comparison with experiment. The model solves a discrete diffusion equation in a reference frame moving with the dislocation, with input solute enthalpies and diffusion activation barriers in the core computed by or estimated from atomistic studies. At low dislocation velocities, the solute drag stress is controlled by bulk solute diffusion because the core diffusion occurs too quickly. In this regime, the drag stress can be obtained using a Peierls–Nabarro model with a core spreading parameter tuned to best match the atomistic models. At intermediate velocities, both bulk and core diffusion can contribute to the drag, leading to a complex stress–velocity relationship showing two peaks in stress. At high velocities, the drag stress is controlled solely by diffusion within and across the core. Like the continuum models, the drag stress is nearly linear in solute concentration. The Orowan relationship is used to connect dislocation velocity to deformation strain rate. Accounting for the dependence of mobile dislocation density on stress, the simulations are in good agreement with experiments on Al–Mg alloys over a range of concentrations and temperatures

  3. Drag force in a D-instanton background (United States)

    Zhang, Zi-qiang; Luo, Zhong-jie; Hou, De-fu


    We study the drag force and diffusion coefficient with respect to a moving heavy quark in a D-instanton background, which corresponds to the Yang-Mills theory in the deconfining, high-temperature phase. It is shown that the presence of the D-instanton density tends to increase the drag force and decrease the diffusion coefficient, reverse to the effects of the velocity and the temperature. Moreover, the inclusion of the D-instanton density makes the medium less viscous.

  4. Thermal Transport and Drag Force in Improved Holographic QCD

    CERN Document Server

    Gürsoy, Umut; Michalogiorgakis, Georgios; Nitti, Francesco; 10.1088


    We calculate the bulk viscosity, drag force and jet quenching parameter in Improved Holographic QCD. We find that the bulk viscosity rises near the phase transition but does not exceed the shear viscosity. The drag force shows the effects of asymptotic freedom both as a function of velocity and temperature. It indicates diffusion times of heavy quarks in rough agreement with data. The jet quenching parameter values computed via the light-like Wilson loop are in the lower range suggested by data.

  5. Progress towards a Drag-free SmallSat (United States)

    Saraf, Shailendhar

    The net force acting on a drag-free satellite is purely gravitational as all other forces, mainly atmospheric drag and solar radiation pressure, are canceled out. In order to achieve this, a free floating reference (test mass) inside the satellite is shielded against all forces but gravity and a system of thrusters is commanded by a control algorithm such that the relative displacement between the reference and the satellite stays constant. The main input to that control algorithm is the output of a sensor which measures the relative displacement between the satellite and the test mass. Internal disturbance forces such as electrostatic or magnetic forces cannot be canceled out his way and have to be minimized by a careful design of the satellite. A drag-free technology package is under development at Stanford since 2004. It includes an optical displacement sensor to measure the relative position of the test mass inside the satellite, a caging mechanism to lock the test mass during launch, a UV LED based charge management system to minimize the effect of electrostatic forces, a thermal enclosure, and the drag-free control algorithms. Possible applications of drag-free satellites in fundamental physics (Gravity Probe B, LISA), geodesy (GOCE), and navigation (TRIAD I). In this presentation we will highlight the progress of the technology development towards a drag-free mission. The planned mission on a SaudiSat bus will demonstrate drag-free technology on a small spacecraft at a fraction of the cost of previous drag-free missions. The target acceleration noise is 10-12 m/sec2. With multiple such satellites a GRACE-like mission with improved sensitivity and potentially improved spatial and temporal resolution can be achieved.

  6. Navier slip model of drag reduction by Leidenfrost vapor layers

    KAUST Repository

    Berry, Joseph D.; Vakarelski, Ivan Uriev; Chan, Derek Y. C.; Thoroddsen, Sigurdur T


    Recent experiments found that a hot solid sphere that is able to sustain a stable Leidenfrost vapor layer in a liquid exhibits significant drag reduction during free fall. The variation of the drag coefficient with Reynolds number deviates substantially from the characteristic drag crisis behavior at high Reynolds numbers. Measurements based on liquids of different viscosities show that the onset of the drag crisis depends on the viscosity ratio of the vapor to the liquid. Here we attempt to characterize the complexity of the Leidenfrost vapor layer with respect to its variable thickness and possible vapor circulation within, in terms of the Navier slip model that is defined by a slip length. Such a model can facilitate tangential flow and thereby alter the behavior of the boundary layer. Direct numerical and large eddy simulations of flow past a sphere at moderate to high Reynolds numbers (102≤Re≤4×104) are employed to quantify comparisons with experimental results, including the drag coefficient and the form of the downstream wake on the sphere. This provides a simple one parameter characterization of the drag reduction phenomenon due to a stable vapor layer that envelops a solid body.

  7. Navier slip model of drag reduction by Leidenfrost vapor layers

    KAUST Repository

    Berry, Joseph D.


    Recent experiments found that a hot solid sphere that is able to sustain a stable Leidenfrost vapor layer in a liquid exhibits significant drag reduction during free fall. The variation of the drag coefficient with Reynolds number deviates substantially from the characteristic drag crisis behavior at high Reynolds numbers. Measurements based on liquids of different viscosities show that the onset of the drag crisis depends on the viscosity ratio of the vapor to the liquid. Here we attempt to characterize the complexity of the Leidenfrost vapor layer with respect to its variable thickness and possible vapor circulation within, in terms of the Navier slip model that is defined by a slip length. Such a model can facilitate tangential flow and thereby alter the behavior of the boundary layer. Direct numerical and large eddy simulations of flow past a sphere at moderate to high Reynolds numbers (102≤Re≤4×104) are employed to quantify comparisons with experimental results, including the drag coefficient and the form of the downstream wake on the sphere. This provides a simple one parameter characterization of the drag reduction phenomenon due to a stable vapor layer that envelops a solid body.

  8. Dragging of inertial frames inside the rotating neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Chandrachur; Modak, Kamakshya Prasad; Bandyopadhyay, Debades, E-mail:, E-mail: [Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India)


    We derive the exact frame-dragging rate inside rotating neutron stars. This formula is applied to show that the frame-dragging rate monotonically decreases from the center to the surface of the neutron star along the pole. In the case of the frame-dragging rate along the equatorial distance, it decreases initially away from the center, becomes negligibly small well before the surface of the neutron star, rises again, and finally approaches to a small value at the surface. The appearance of a local maximum and minimum in this case is the result of the dependence of frame-dragging frequency on the distance and angle. Moving from the equator to the pole, it is observed that this local maximum and minimum in the frame-dragging rate along the equator disappear after crossing a critical angle. It is also noted that the positions of the local maximum and minimum of the frame-dragging rate along the equator depend on the rotation frequency and central energy density of a particular pulsar.

  9. Aerodynamic drag of modern soccer balls. (United States)

    Asai, Takeshi; Seo, Kazuya


    Soccer balls such as the Adidas Roteiro that have been used in soccer tournaments thus far had 32 pentagonal and hexagonal panels. Recently, the Adidas Teamgeist II and Adidas Jabulani, respectively having 14 and 8 panels, have been used at tournaments; the aerodynamic characteristics of these balls have not yet been verified. Now, the Adidas Tango 12, having 32 panels, has been developed for use at tournaments; therefore, it is necessary to understand its aerodynamic characteristics. Through a wind tunnel test and ball trajectory simulations, this study shows that the aerodynamic resistance of the new 32-panel soccer ball is larger in the high-speed region and lower in the middle-speed region than that of the previous 14- and 8-panel balls. The critical Reynolds number of the Roteiro, Teamgeist II, Jabulani, and Tango 12 was ~2.2 × 10(5) (drag coefficient, C d  ≈ 0.12), ~2.8 × 10(5) (C d  ≈ 0.13), ~3.3 × 10(5) (C d  ≈ 0.13), and ~2.4 × 10(5) (C d  ≈ 0.15), respectively. The flight trajectory simulation suggested that the Tango 12, one of the newest soccer balls, has less air resistance in the medium-speed region than the Jabulani and can thus easily acquire large initial velocity in this region. It is considered that the critical Reynolds number of a soccer ball, as considered within the scope of this experiment, depends on the extended total distance of the panel bonds rather than the small designs on the panel surfaces.

  10. Assessment of the Unstructured Grid Software TetrUSS for Drag Prediction of the DLR-F4 Configuration (United States)

    Pirzadeh, Shahyar Z.; Frink, Neal T.


    An application of the NASA unstructured grid software system TetrUSS is presented for the prediction of aerodynamic drag on a transport configuration. The paper briefly describes the underlying methodology and summarizes the results obtained on the DLR-F4 transport configuration recently presented in the first AIAA computational fluid dynamics (CFD) Drag Prediction Workshop. TetrUSS is a suite of loosely coupled unstructured grid CFD codes developed at the NASA Langley Research Center. The meshing approach is based on the advancing-front and the advancing-layers procedures. The flow solver employs a cell-centered, finite volume scheme for solving the Reynolds Averaged Navier-Stokes equations on tetrahedral grids. For the present computations, flow in the viscous sublayer has been modeled with an analytical wall function. The emphasis of the paper is placed on the practicality of the methodology for accurately predicting aerodynamic drag data.

  11. Statistical Analysis of CFD Solutions from the Fourth AIAA Drag Prediction Workshop (United States)

    Morrison, Joseph H.


    A graphical framework is used for statistical analysis of the results from an extensive N-version test of a collection of Reynolds-averaged Navier-Stokes computational fluid dynamics codes. The solutions were obtained by code developers and users from the U.S., Europe, Asia, and Russia using a variety of grid systems and turbulence models for the June 2009 4th Drag Prediction Workshop sponsored by the AIAA Applied Aerodynamics Technical Committee. The aerodynamic configuration for this workshop was a new subsonic transport model, the Common Research Model, designed using a modern approach for the wing and included a horizontal tail. The fourth workshop focused on the prediction of both absolute and incremental drag levels for wing-body and wing-body-horizontal tail configurations. This work continues the statistical analysis begun in the earlier workshops and compares the results from the grid convergence study of the most recent workshop with earlier workshops using the statistical framework.

  12. Statistical Analysis of CFD Solutions From the Fifth AIAA Drag Prediction Workshop (United States)

    Morrison, Joseph H.


    A graphical framework is used for statistical analysis of the results from an extensive N-version test of a collection of Reynolds-averaged Navier-Stokes computational fluid dynamics codes. The solutions were obtained by code developers and users from North America, Europe, Asia, and South America using a common grid sequence and multiple turbulence models for the June 2012 fifth Drag Prediction Workshop sponsored by the AIAA Applied Aerodynamics Technical Committee. The aerodynamic configuration for this workshop was the Common Research Model subsonic transport wing-body previously used for the 4th Drag Prediction Workshop. This work continues the statistical analysis begun in the earlier workshops and compares the results from the grid convergence study of the most recent workshop with previous workshops.

  13. STS-58 Landing at Edwards with Drag Chute (United States)


    A drag chute slows the space shuttle Columbia as it rolls to a perfect landing concluding NASA's longest mission at that time, STS-58, at the Ames-Dryden Flight Research Facility (later redesignated the Dryden Flight Research Center), Edwards, California, with a 8:06 a.m. (PST) touchdown 1 November 1993 on Edward's concrete runway 22. The planned 14 day mission, which began with a launch from Kennedy Space Center, Florida, at 7:53 a.m. (PDT), October 18, was the second spacelab flight dedicated to life sciences research. Seven Columbia crewmembers performed a series of experiments to gain more knowledge on how the human body adapts to the weightless environment of space. Crewmembers on this flight included: John Blaha, commander; Rick Searfoss, pilot; payload commander Rhea Seddon; mission specialists Bill MacArthur, David Wolf, and Shannon Lucid; and payload specialist Martin Fettman. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space

  14. Bag-breakup control of surface drag in hurricanes (United States)

    Troitskaya, Yuliya; Zilitinkevich, Sergej; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil


    consequent breaking of short-lived, sail-like pieces of the water-surface film - "bags". On the base of general principles of statistical physics (model of a canonical ensemble) we developed statistics of the "bag-breakup" events: their number and statistical distribution of geometrical parameters depending on wind speed. Basing on the developed statistics, we estimated the surface stress caused by bags as the average sum of stresses caused by individual bags depending on their eometrical parameters. The resulting stress is subjected to counteracting impacts of the increasing wind speed: the increasing number of bags, and their decreasing sizes and life times and the balance yields a peaking dependence of the bag resistance on the wind speed: the share of bag-stress peaks at U10  35 m/s and then reduces. Peaking of surface stress associated with the "bag-breakup" explains seemingly paradoxical non-monotonous wind-dependence of surface drag coefficient peaking at winds about 35 m/s. This work was supported by the Russian Foundation of Basic Research (14-05-91767, 13-05-12093, 16-05-00839, 14-05-91767, 16-55-52025, 15-35-20953) and experiment and equipment was supported by Russian Science Foundation (Agreements 14-17-00667 and 15-17-20009 respectively), Yu.Troitskaya, A.Kandaurov and D.Sergeev were partially supported by FP7 Collaborative Project No. 612610.

  15. Higher Magnitude Cash Payments Improve Research Follow-up Rates Without Increasing Drug Use or Perceived Coercion (United States)

    Festinger, David S.; Marlowe, Douglas B.; Dugosh, Karen L.; Croft, Jason R.; Arabia, Patricia L.


    In a prior study (Festinger et al., 2005) we found that neither the mode (cash vs. gift card) nor magnitude ($10, $40, or $70) of research follow-up payments increased rates of new drug use or perceptions of coercion. However, higher payments and payments in cash were associated with better follow-up attendance, reduced tracking efforts, and improved participant satisfaction with the study. The present study extended those findings to higher payment magnitudes. Participants from an urban outpatient substance abuse treatment program were randomly assigned to receive $70, $100, $130, or $160 in either cash or a gift card for completing a follow-up assessment at 6 months post-admission (n ≅ 50 per cell). Apart from the payment incentives, all participants received a standardized, minimal platform of follow-up efforts. Findings revealed that neither the magnitude nor mode of payment had a significant effect on new drug use or perceived coercion. Consistent with our previous findings, higher payments and cash payments resulted in significantly higher follow-up rates and fewer tracking calls. In addition participants receiving cash vs. gift cards were more likely to use their payments for essential, non-luxury purchases. Follow-up rates for participants receiving cash payments of $100, $130, and $160 approached or exceeded the FDA required minimum of 70% for studies to be considered in evaluations of new medications. This suggests that the use of higher magnitude payments and cash payments may be effective strategies for obtaining more representative follow-up samples without increasing new drug use or perceptions of coercion. PMID:18395365

  16. Information Literacy Threshold Concepts and the Association of College and Research Libraries' Framework for Information Literacy for Higher Education

    Directory of Open Access Journals (Sweden)

    Gayle Schaub


    Full Text Available The 2014 release of the Association of College and Research Libraries’ Framework for Information Literacy for Higher Education had a significant impact on information literacy scholarship and practice in the United States. The revision process of the previous Competency Standards and the purpose and implementation of the new Framework are still widely discussed as librarians work out what the Framework means to individual institutions and to information literacy as a whole. Organized around six threshold concepts in information literacy as identified in recent research, the Framework reflects developments in the information landscape as threshold concepts have become influential. The authors, who began their research in threshold concepts at the same time as the use and discussion of information literacy threshold concepts increased in the United States, discuss how their work fits into a larger, national conversation on conceptual information literacy instruction and the creation of a high-profile document.   Die Verabschiedung des Framework for Information Literacy for Higher Education der Association of College and Research Libraries 2014 hatte beachtliche Auswirkungen auf Theorie und Praxis der Vermittlung von Informationskompetenz in den USA. Der Überarbeitungsprozess der früheren Standards Informationskompetenz sowie Zielrichtung und Umsetzung des neuen Framework werden nach wie vor breit diskutiert, da Bibliothekar/inn/e/n nun konkretisieren, was das Framework für ihre jeweilige Einrichtung und für Informationskompetenz insgesamt bedeutet. Indem es um sechs threshold concepts gruppiert ist, die die aktuelle Forschung zu Informationskompetenz identifiziert hat, bezieht das Framework gezielt Entwicklungen der Informationslandschaft auf diese richtungsweisenden threshold concepts. Die Autorinnen, die ihre Untersuchungen zu threshold concepts just zu der Zeit begannen, zu der der Einsatz von und die Diskussion um threshold concepts in

  17. Octopus-inspired drag cancelation by added mass pumping (United States)

    Weymouth, Gabriel; Giorgio-Serchi, Francesco


    Recent work has shown that when an immersed body suddenly changes its size, such as a deflating octopus during rapid escape jetting, the body experiences large forces due to the variation of added-mass energy. We extend this line of research by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. This system isolates the ability of the added-mass thrust to cancel the bluff body resistance (having no jet flow to confuse the analysis) and moves closer to studying how these effects would work in a sustained propulsion case by studying periodic shape-change instead of a "one-shot" escape maneuver. With a combination of analytical, numerical, and experimental results, we show that the recovery of added-mass kinetic energy can be used to completely cancel the drag of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius. Moreover, these results are fairly independent of the details of the shape-change kinematics as long as the Stokes number and shape-change number are large. In addition, the effective pumping frequency range based on parametric oscillator analysis is shown to predict large amplitude response region observed in the numerics and experiments.

  18. STS-49 Landing at Edwards with First Drag Chute Landing (United States)


    The Space Shuttle Endeavour concludes mission STS-49 at NASA's Ames-Dryden Flight Research Facility (later redesignated Dryden Flight Research Center), Edwards, California, with a 1:57 p.m. (PDT) landing 16 May on Edward's concrete runway 22. The planned 7-day mission, which began with a launch from Kennedy Space Center, Florida, at 4:41 p.m. (PFT), 7 May, was extended two days to allow extra time to rescue the Intelsat VI satellite and complete Space Station assembly techniques originally planned. After a perfect rendezvous in orbit and numerous attempts to grab the satellite, space walking astronauts Pierre Thuot, Rick Hieb and Tom Akers successfully rescued it by hand on the third space walk with the support of mission specialists Kathy Thornton and Bruce Melnick. The three astronauts, on a record space walk, took hold of the satellite and directed it to the shuttle where a booster motor was attached to launch it to its proper orbit. Commander Dan Brandenstein and Pilot Kevin Chilton brought Endeavours's record setting maiden voyage to a perfect landing at Edwards AFB with the first deployment of a drag chute on a shuttle mission. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their

  19. Satellite drag effects due to uplifted oxygen neutrals during super magnetic storms

    Directory of Open Access Journals (Sweden)

    G. S. Lakhina


    Full Text Available During intense magnetic storms, prompt penetration electric fields (PPEFs through E  ×  B forces near the magnetic equator uplift the dayside ionosphere. This effect has been called the dayside super-fountain effect. Ion-neutral drag forces between the upward moving O+ (oxygen ions and oxygen neutrals will elevate the oxygen atoms to higher altitudes. This paper gives a linear calculation indicating how serious the effect may be during an 1859-type (Carrington superstorm. It is concluded that the oxygen neutral densities produced at low-Earth-orbiting (LEO satellite altitudes may be sufficiently high to present severe satellite drag. It is estimated that with a prompt penetrating electric field of ∼ 20 mV m−1 turned on for 20 min, the O atoms and O+ ions are uplifted to 850 km where they produce about 40-times-greater satellite drag per unit mass than normal. Stronger electric fields will presumably lead to greater uplifted mass.

  20. Experimental measurement of unsteady drag on shock accelerated micro-particles (United States)

    Bordoloi, Ankur; Martinez, Adam; Prestridge, Katherine


    The unsteady drag history of shock accelerated micro-particles in air is investigated in the Horizontal Shock Tube (HST) facility at Los Alamos National laboratory. Drag forces are estimated based on particle size, particle density, and instantaneous velocity and acceleration measured on hundreds of post-shock particle tracks. We use previously implemented 8-frame Particle Tracking Velocimetry/Anemometry (PTVA) diagnostics to analyze particles in high spatiotemporal resolution from individual particle trajectories. We use a simultaneous LED based shadowgraph to register shock location with respect to a moving particle in each frame. To measure particle size accurately, we implement a Phase Doppler Particle Analyzer (PDPA) in synchronization with the PTVA. In this presentation, we will corroborate with more accuracy our earlier observation that post-shock unsteady drag coefficients (CD(t)) are manifold times higher than those predicted by theoretical models. Our results will also show that all CD(t) measurements collapse on a master-curve for a range of particle size, density, Mach number and Reynolds number when time is normalized by a shear velocity based time scale, t* = d/(uf-up) , where d is particle diameter, and uf and up are post-shock fluid and particle velocities.

  1. Nation Drag: Uses of the Exotic

    Directory of Open Access Journals (Sweden)

    Micol Seigel


    Full Text Available

    In Uneven Encounters, the forthcoming book from which this article is excerpted, Micol Seigel chronicles the exchange of popular culture between Brazil and the United States in the years between the World Wars, and she demonstrates how that exchange affected ideas of race and nation in both countries. From Americans interpreting advertisements for Brazilian coffee or dancing the Brazilian maxixe, to Rio musicians embracing the “foreign” qualities of jazz, Seigel traces a lively, cultural back-and-forth. Along the way, she shows how race and nation are constructed together, by both non-elites and elites, and gleaned from global cultural and intellectual currents as well as local, regional, and national ones. Seigel explores the circulation of images of Brazilian coffee and of maxixe in the United States during the period just after the imperial expansions of the early twentieth century. Exoticist interpretations structured North Americans’ paradoxical sense of self as productive “consumer citizens.” Some people, however, could not simply assume the privileges of citizenship. In their struggles against racism, Afro-descended citizens living in the cities of Rio de Janeiro, São Paulo, New York, and Chicago encountered images and notions of each other, and found them useful. Seigel introduces readers to cosmopolitan Afro-Brazilians and African Americans who rarely traveled far but who absorbed ideas from abroad nonetheless. African American vaudeville artists saw the utility of pretending to “be” Brazilian to cross the color line on stage. Putting on “nation drag,” they passed not from one race to another but out of familiar racial categories entirely. Afro-Brazilian journalists reported intensively on foreign, particularly North American, news and eventually entered into conversation with the U.S. black press in a collaborative but still conflictual dialogue. Seigel suggests that projects comparing U.S. and

  2. Nation Drag: Uses of the Exotic

    Directory of Open Access Journals (Sweden)

    Micol Seigel


    Full Text Available In Uneven Encounters, the forthcoming book from which this article is excerpted, Micol Seigel chronicles the exchange of popular culture between Brazil and the United States in the years between the World Wars, and she demonstrates how that exchange affected ideas of race and nation in both countries. From Americans interpreting advertisements for Brazilian coffee or dancing the Brazilian maxixe, to Rio musicians embracing the “foreign” qualities of jazz, Seigel traces a lively, cultural back-and-forth. Along the way, she shows how race and nation are constructed together, by both non-elites and elites, and gleaned from global cultural and intellectual currents as well as local, regional, and national ones. Seigel explores the circulation of images of Brazilian coffee and of maxixe in the United States during the period just after the imperial expansions of the early twentieth century. Exoticist interpretations structured North Americans’ paradoxical sense of self as productive “consumer citizens.” Some people, however, could not simply assume the privileges of citizenship. In their struggles against racism, Afro-descended citizens living in the cities of Rio de Janeiro, São Paulo, New York, and Chicago encountered images and notions of each other, and found them useful. Seigel introduces readers to cosmopolitan Afro-Brazilians and African Americans who rarely traveled far but who absorbed ideas from abroad nonetheless. African American vaudeville artists saw the utility of pretending to “be” Brazilian to cross the color line on stage. Putting on “nation drag,” they passed not from one race to another but out of familiar racial categories entirely. Afro-Brazilian journalists reported intensively on foreign, particularly North American, news and eventually entered into conversation with the U.S. black press in a collaborative but still conflictual dialogue. Seigel suggests that projects comparing U.S. and Brazilian racial

  3. A research technique for the effect of higher harmonic voltages on the operating parameters of a permanent magnet synchronous generator

    Directory of Open Access Journals (Sweden)

    Hasanova L. H.


    Full Text Available Nowadays permanent magnet synchronous machines those frequency-controlled from stator side with frequency inverters made on the basis of power transistors or fully controlled thyristors, are widely used as motors and generators. In future they are also promising a good application in transport, including marine. Modern frequency inverters are equipped with a control system based on sine-shaped pulse width modulation. While shaping the voltage in the output of the inverter, in addition to the fundamental harmonic, higher harmonic components are also included in the voltage shape, which certainly affect the operating parameters of the generator (electromagnetic torque, power, currents. To determine this effect the modeling and investigation technique of higher harmonic voltages in the "electric network – frequency converter – synchronous machine with permanent magnets" system has been developed. The proposed equations of a frequency-controlled permanent magnet synchronous machine allow relatively simply reproduce the harmonic composition of the voltage in the output of a frequency inverter equipped with the control system based on a sinusoidal pulse width modulation. The developed research technique can be used for inverters with any number and composition of voltage harmonic components feeding a stator winding of a permanent magnet synchronous machine. On a particular case, the efficiency of the research technique of the higher harmonics influence on the operating parameters of the generator has been demonstrated. At the same time, the study has been carried out taking into account the shape of the voltage curve feeding the windings of the synchronous machine containing in addition to the fundamental harmonic the 8, 10, 11, 13, 14 and 16-th harmonic components, and the rated active power of the synchronous machine has been equal to 1 500 kW.

  4. Wind-Tunnel Investigations of Blunt-Body Drag Reduction Using Forebody Surface Roughness (United States)

    Whitmore, Stephen A.; Sprague, Stephanie; Naughton, Jonathan W.; Curry, Robert E. (Technical Monitor)


    This paper presents results of wind-tunnel tests that demonstrate a novel drag reduction technique for blunt-based vehicles. For these tests, the forebody roughness of a blunt-based model was modified using micomachined surface overlays. As forebody roughness increases, boundary layer at the model aft thickens and reduces the shearing effect of external flow on the separated flow behind the base region, resulting in reduced base drag. For vehicle configurations with large base drag, existing data predict that a small increment in forebody friction drag will result in a relatively large decrease in base drag. If the added increment in forebody skin drag is optimized with respect to base drag, reducing the total drag of the configuration is possible. The wind-tunnel tests results conclusively demonstrate the existence of a forebody dragbase drag optimal point. The data demonstrate that the base drag coefficient corresponding to the drag minimum lies between 0.225 and 0.275, referenced to the base area. Most importantly, the data show a drag reduction of approximately 15% when the drag optimum is reached. When this drag reduction is scaled to the X-33 base area, drag savings approaching 45,000 N (10,000 lbf) can be realized.

  5. Systematic Review of the Research on Motor Fitness of 1st-Year Students Attending Polish Institutions of Higher Education

    Directory of Open Access Journals (Sweden)

    Robert Podstawski


    Full Text Available Aim of the study. To establish: 1 the amount of research on general motor fitness of 1st-year students, conducted at selected Polish institutions of higher education between 1953-2010; 2 the number and kind of motor tests applied in this kind of research as well as the frequency of these tests during the period under study. Material and methods: The material for this research was composed of the publications on motor fitness of the first-year students taking part in specific motor trials applied at Polish tertiary institutions between 1953 - 2010. A diagnostic poll method was used in the research. Results: Fifty-four original research cases conducted in the period under study were observed. Within this period the trials such as: “100m run”, “jump from the run-up”, “grenade throw” and “ shot put” were more popular during the earlier years, while the trials such us: “zig-zag run”, “standing long jump”, and “medicine ball throw” were characteristic of more recent studies. Some of the most popular motor trials were: “standing long jump” – 38 cases, “medicine ball throw” – 30 cases, “zig-zag run” – 28 cases, “shuttle runs” – 9 cases, "short distance runs” – 12 cases, “downward bend from standing position” – 10 cases, and "vertical jump” – 8 cases. Conclusions: 1. Little research concerning the level of physical fitness of first-year students attending Polish tertiary institutions was conducted in the years 1953-2010; 2. The amount of motor fitness research carried out during this period fails to provide constant systematic assessment of the state of the students’ physical condition, which is a result of too large dispersions in time and territory where the measurements were taken; 3. In the motor fitness tests conducted with 1st-year students the determining variable was mainly gender, and only few research cases were found in which general motor fitness was analyzed according to

  6. E-portfolios and personalized learning: research in practice with two dyslexic learners in UK higher education. (United States)

    Hughes, Julie; Herrington, Margaret; McDonald, Tess; Rhodes, Amy


    This paper analyses the use of an e-portfolio system in contributing to the personalized learning of two dyslexic learners at the University of Wolverhampton, UK. The rationale for this research rests at the intersection of generic findings from e-portfolio (and wider e-learning) research and the still challenging project in higher education (HE) of creating inclusive curricula. A qualitative, ethnographic approach was employed in a piece of collaborative research between academic staff and dyslexic learners. Two retrospective learner narratives were constructed and then reviewed by all co-authors in terms of the 'personalized fit' which they allowed with dyslexic thinking, learning and writing experience. The findings suggest a potential refinement of the general pedagogical claims about e-portfolio-based learning when considering dyslexic learners and thence the value of an enhanced prioritization of e-portfolio learning practices within inclusive HE curricula. The review and analysis also allow a 'critical' discussion of the practical and theoretical issues arising within this work. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Drag Reduction CFD Simulations and Flow Visualization of Light Vehicle-Trailer Systems (United States)

    Sigurdson, Lorenz; Boyer, Henry; Lange, Carlos F.


    Experiments and CFD were performed to study the effect a deflector had on the flow and drag force associated with a 2010 F-150 truck and cargo trailer Light Vehicle-Trailer System (LVTS). Image Correlation Velocimetry (ICV) on smokewire streaklines measured the velocity field on the model mid-plane. CFD estimated the drag reduction as 13% at a Re of 14,900 with a moving ground-plane, and 17% without. Experiments suggested that the low Re does not diminish the full-scale relevance of the drag reduction results. One low Re effect was the presence of a separation bubble on the hood of the tow vehicle whose size reduced with an increase in Re. Three other characteristic flow patterns were identified: separation off the lead vehicle cab, stagnation of the free-stream on the trailer face for the no-deflector case, and subsequent separation at the trailer front corner. Comparisons of the ICV and CFD results with no deflector indicated good agreement in the direction of the velocity vectors, and the smoke streaklines and CFD streamlines also agreed well. However, for the deflector case, the CFD found an entirely different topological solution absent in the experiment. A pair of vertically-oriented mid-plane vortices were wrapped around the front of the trailer. Support from the Canadian Natural Sciences and Engineering Research Council Grant 41747 is gratefully acknowledged.

  8. Progress report on INEL full flow drag screen

    International Nuclear Information System (INIS)

    Arave, A.E.; Colson, J.B.; Fincke, J.R.


    The objective in developing a full flow drag screen is to obtain a total momentum flux measurement which when combined with a suitable independent velocity or density measurement will yield a total mass flux. The major design considerations are predicated by the fact that an accurate momentum flux measurement must be made over a wide range of flow conditions. The device should exhibit a constant calibration regardless of Reynolds number, void fraction, slip ratio, or flow regime. The dynamics of drag devices are well understood in single-phase flows. This is not true for two-phase flows. The present development program is directed toward gaining an understanding of the dynamics of drag devices which sample the total area of a pipe in two-phase flow and developing a method for deducing mass flow rate using such a device. Various geometric arrangements are to be investigated. Testing to date has shown excellent results using a round wire mesh screen in the Semiscale air/water loop. Future air/water testing will include perforated plates and wire meshes with both rectangular and diamond shaped cross sections. Analytical models of the hydrodynamics of the drag screen as well as the associated density or velocity measuring device are being used to select the optimum configuration. Alternate force sensing methods are also being considered. These include single and multiple transducer arrangements. Multistage springs and pressure drop across the body are to be evaluated for extending the dynamic range of the drag body

  9. The Overall Drag Losses For A Combination of Bodies

    Directory of Open Access Journals (Sweden)

    Sabah Al-Janabi


    Full Text Available The objective of this work is to obtain better understanding of the flow over a combination of bluff bodies in close enough proximity to strongly interact with each other. This interaction is often beneficial in that the drag of the overall system is reduced. Proto-types for this problem come from tractor- trailer and missiles, and from various add-on devices designed to reduce their drag. Thus, an experimental investigation was carried out by placing  conical frontal bodies having a base diameter of 0.65 cylinder diameter with different vertex angles (30°, 50°, 70°, and 90°. It was found that, the bluffer cone with 90° vertex angle gives the best minimum drag, which is 31% lower than the drag of the isolated cylinder. Also an interesting phenomenon was observed in that, the minimum drags for all combinations are obtained at the same gap ratio ( g/d2= 0.365.

  10. A Conventional Liner Acoustic/Drag Interaction Benchmark Database (United States)

    Howerton, Brian M.; Jones, Michael G.


    The aerodynamic drag of acoustic liners has become a significant topic in the design of such for aircraft noise applications. In order to evaluate the benefits of concepts designed to reduce liner drag, it is necessary to establish the baseline performance of liners employing the typical design features of conventional configurations. This paper details a set of experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of a number of perforate-over-honeycomb liner configurations at flow speeds of M=0.3 and 0.5. These conventional liners are investigated to determine their resistance factors using a static pressure drop approach. Comparison of the resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 Hz at source sound pressure levels of 140 and 150 dB. Educed impedance and attenuation spectra are used to determine the interaction between acoustic performance and drag.

  11. Relativistic Gas Drag on Dust Grains and Implications

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Thiem, E-mail: [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Korea University of Science and Technology, Daejeon, 34113 (Korea, Republic of)


    We study the drag force on grains moving at relativistic velocities through interstellar gas and explore its application. First, we derive a new analytical formula of the drag force at high energies and find that it is significantly reduced compared to the classical model. Second, we apply the obtained drag force to calculate the terminal velocities of interstellar grains by strong radiation sources such as supernovae and active galactic nuclei (AGNs). We find that grains can be accelerated to relativistic velocities by very luminous AGNs. We then quantify the deceleration of relativistic spacecraft proposed by the Breakthrough Starshot initiative due to gas drag on a relativistic lightsail. We find that the spacecraft’s decrease in speed is negligible because of the suppression of gas drag at relativistic velocities, suggesting that the lightsail may be open for communication during its journey to α Centauri without causing a considerable delay. Finally, we show that the damage to relativistic thin lightsails by interstellar dust is a minor effect.

  12. Drag reduction in channel flow using nonlinear control (United States)

    Keefe, Laurence R.


    Two nonlinear control schemes have been applied to the problem of drag reduction in channel flow. Both schemes have been tested using numerical simulations at a mass flux Reynolds numbers of 4408, utilizing 2D nonlinear neutral modes for goal dynamics. The OGY-method, which requires feedback, reduces drag to 60-80 percent of the turbulent value at the same Reynolds number, and employs forcing only within a thin region near the wall. The H-method, or model-based control, fails to achieve any drag reduction when starting from a fully turbulent initial condition, but shows potential for suppressing or retarding laminar-to-turbulent transition by imposing instead a transition to a low drag, nonlinear traveling wave solution to the Navier-Stokes equation. The drag in this state corresponds to that achieved by the OGY-method. Model-based control requires no feedback, but in experiments to date has required the forcing be imposed within a thicker layer than the OGY-method. Control energy expenditures in both methods are small, representing less than 0.1 percent of the uncontrolled flow's energy.

  13. Creating drag and lift curves from soccer trajectories (United States)

    Goff, John Eric; Kelley, John; Hobson, Chad M.; Seo, Kazuya; Asai, Takeshi; Choppin, S. B.


    Trajectory analysis is an alternative to using wind tunnels to measure a soccer ball’s aerodynamic properties. It has advantages over wind tunnel testing such as being more representative of game play. However, previous work has not presented a method that produces complete, speed-dependent drag and lift coefficients. Four high-speed cameras in stereo-calibrated pairs were used to measure the spatial co-ordinates for 29 separate soccer trajectories. Those trajectories span a range of launch speeds from 9.3 to 29.9 m s-1. That range encompasses low-speed laminar flow of air over a soccer ball, through the drag crises where air flow is both laminar and turbulent, and up to high-speed turbulent air flow. Results from trajectory analysis were combined to give speed-dependent drag and lift coefficient curves for the entire range of speeds found in the 29 trajectories. The average root mean square error between the measured and modelled trajectory was 0.028 m horizontally and 0.034 m vertically. The drag and lift crises can be observed in the plots of drag and lift coefficients respectively.

  14. Theory of Coulomb drag for massless Dirac fermions

    International Nuclear Information System (INIS)

    Carrega, M; Principi, A; Polini, M; Tudorovskiy, T; Katsnelson, M I


    Coulomb drag between two unhybridized graphene sheets separated by a dielectric spacer has recently attracted considerable theoretical interest. We first review, for the sake of completeness, the main analytical results which have been obtained by other authors. We then illustrate pedagogically the minimal theory of Coulomb drag between two spatially separated two-dimensional systems of massless Dirac fermions which are both away from the charge-neutrality point. This relies on second-order perturbation theory in the screened interlayer interaction and on Boltzmann-transport theory. In this theoretical framework and in the low-temperature limit, we demonstrate that, to leading (i.e. quadratic) order in temperature, the drag transresistivity is completely insensitive to the precise intralayer momentum-relaxation mechanism (i.e. to the functional dependence of the transport scattering time on energy). We also provide analytical results for the low-temperature drag transresistivity for both cases of ‘thick’ and ‘thin’ spacers and for arbitrary values of the dielectric constants of the media surrounding the two Dirac-fermion layers. Finally, we present numerical results for the low-temperature drag transresistivity for the case when one of the media surrounding the Dirac-fermion layers has a frequency-dependent dielectric constant. We conclude by suggesting an experiment that can potentially allow for the observation of departures from the canonical quadratic-in-temperature behavior of the transresistivity. (paper)

  15. The Air Force Academy’s Falcon Telescope Network: An Educational and Research Network for K-12 and Higher Education (United States)

    Chun, Francis; Tippets, Roger; Della-Rose, Devin J.; Polsgrove, Daniel; Gresham, Kimberlee; Barnaby, David A.


    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. USAFA cadets use the FTN to continue a tradition of satellite characterization and astronomical research; this tradition is the model used for designing the network to serve undergraduate research needs. Additionally, cadets have led the development of the FTN by investigating observation priority schemes and conducting a 'day-in-the-life' study of the FTN in regards to satellite observations. With respect to K-12 outreach, cadets have provided feedback to K-12 students and teachers through evaluation of first-light proposals. In this paper, we present the current status of the network and results from student participation in the project.

  16. Life Outcomes and Higher Education: The Need for Longitudinal Research Using a Broad Range of Quality of Life Indicators. (United States)

    Sheppard-Jones, Kathleen; Kleinert, Harold; Butler, Laura; Whaley, Barry


    Higher education is increasingly becoming an option for young adults with intellectual disability (ID). Although initial evaluations of postsecondary education for this population have been promising, a broader "quality of life" framework needs to be adopted in order to truly understand the impact of these programs. Moreover, researchers and program evaluators must collect longitudinal data that follows former students for multiple years and uses multiple measures. We conducted a pilot evaluation of the life outcomes of students who had attended at least two semesters in Kentucky's supported higher education program for students with ID, collecting data on life status and experiences using measures from the National Core Indicators-Adult Consumer Survey. The findings from this pilot study show better outcomes for young adults who participated in a postsecondary education program compared to young adults who did not, but these findings need to be considered in light of several limitations. In many respects, our data provided more new questions than answers. Recommendations for collecting and evaluating broad-based, longitudinal data to gain insight into the potential benefits of postsecondary education for people with intellectual disability are discussed.

  17. Acoustic Liner Drag: Measurements on Novel Facesheet Perforate Geometries (United States)

    Howerton, Brian M.; Jones, Michael G.


    Interest in characterization of the aerodynamic drag of acoustic liners has increased in the past several years. This paper details experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of several perforate-over-honeycomb liner configurations at flow speeds of centerline flow Mach number equals 0.3 and 0.5. Various perforate geometries and orientations are investigated to determine their resistance factors using a static pressure drop approach. Comparison of these resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 hertz at source sound pressure levels of 140 and 150 decibels. Educed impedance and attenuation spectra are used to determine the impact of variations in perforate geometry on acoustic performance.

  18. Flexural phonon limited phonon drag thermopower in bilayer graphene (United States)

    Ansari, Mohd Meenhaz; Ashraf, SSZ


    We investigate the phonon drag thermopower from flexural phonons as a function of electron temperature and carrier concentration in the Bloch-Gruneisen regime in non-strained bilayer graphene using Boltzmann transport equation approach. The flexural phonons are expected to be the major source of intrinsic scattering mechanism in unstrained bilayer graphene due to their large density. The flexural phonon modes dispersion relation is quadratic so these low energy flexural phonons abound at room temperature and as a result deform the bilayer graphene sheet in the out of plane direction and affects the transport properties. We also produce analytical result for phonon-drag thermopower from flexural phonons and find that phonon-drag thermopower depicts T2 dependence on temperature and n-1 on carrier concentration.

  19. Spanwise drag variation on low Re wings -- revisited (United States)

    Yang, Shanling; Spedding, Geoffrey


    Aerodynamic performance measurement and prediction of airfoils and wings at chord Reynolds numbers below 105 is both difficult and increasingly important in application to small-scale aircraft. Not only are the aerodynamics strongly affected by the dynamics of the unstable laminar boundary layer but the flow is decreasingly likely to be two-dimensional as Re decreases. The spanwise variation of the flow along a two-dimensional geometry is often held to be responsible for the large variations in measured profile drag coefficient. Here we measure local two-dimensional drag coefficients along a finite wing using non-intrusive PIV methods. Variations in Cd (y) can be related to local flow variations on the wing itself. Integrated values can be compared with force balance data, and the proper description of drag components at low Re will be discussed.

  20. Locus of the apices of projectile trajectories under constant drag (United States)

    Hernández-Saldaña, H.


    Using the hodograph method, we present an analytical solution for projectile coplanar motion under constant drag, parametrised by the velocity angle. We find the locus formed by the apices of the projectile trajectories, and discuss its implementation for the motion of a particle on an inclined plane in presence of Coulomb friction. The range and time of flight are obtained numerically, and we find that the optimal launching angle is smaller than in the drag-free case. This is a good example of a problem with constant dissipation of energy that includes curvature; it is appropriate for intermediate courses of mechanics.

  1. The effects of Poynting–Robertson drag on solar sails

    Directory of Open Access Journals (Sweden)

    F.A. Abd El-Salam


    Full Text Available In the present work, the concept of solar sailing and its developing spacecraft are presented. The effects of Poynting–Robertson drag on solar sails are considered. Some analytical control laws with some mentioned input constraints for optimizing solar sails dynamics in heliocentric orbit using Lagrange’s planetary equations are obtained. Optimum force vector in a required direction is maximized by deriving optimal sail cone angle. New control laws that maximize thrust to obtain certain required maximization in some particular orbital element are obtained. Keywords: Poynting–Robertson drag, Solar sail, Control laws, Optimal sail, Cone angle

  2. A hypersonic lift mechanism with decoupled lift and drag surfaces (United States)

    Xu, YiZhe; Xu, ZhiQi; Li, ShaoGuang; Li, Juan; Bai, ChenYuan; Wu, ZiNiu


    In the present study, we propose a novel lift mechanism for which the lifting surface produces only lift. This is achieved by mounting a two-dimensional shock-shock interaction generator below the lifting surface. The shock-shock interaction theory in conjunction with a three dimensional correction and checked with computational fluid dynamics (CFD) is used to analyze the lift and drag forces as function of the geometrical parameters and inflow Mach number. Through this study, though limited to only inviscid flow, we conclude that it is possible to obtain a high lift to drag ratio by suitably arranging the shock interaction generator.

  3. Drag force in a strongly coupled anisotropic plasma (United States)

    Chernicoff, Mariano; Fernández, Daniel; Mateos, David; Trancanelli, Diego


    We calculate the drag force experienced by an infinitely massive quark propagating at constant velocity through an anisotropic, strongly coupled {N} = 4 plasma by means of its gravity dual. We find that the gluon cloud trailing behind the quark is generally misaligned with the quark velocity, and that the latter is also misaligned with the force. The drag coefficient μ can be larger or smaller than the corresponding isotropic value depending on the velocity and the direction of motion. In the ultra-relativistic limit we find that generically μ ∝ p. We discuss the conditions under which this behaviour may extend to more general situations.

  4. Control of the electromagnetic drag using fluctuating light fields (United States)

    Pastor, Víctor J. López; Marqués, Manuel I.


    An expression for the electromagnetic drag force experienced by an electric dipole in a light field consisting of a monochromatic plane wave with polarization and phase randomly fluctuating is obtained. The expression explicitly considers the transformations of the field and frequency due to the Doppler shift and the change of the polarizability response of the electric dipole. The conditions to be fulfilled by the polarizability of the dipole in order to obtain a positive, a null, and a negative drag coefficient are analytically determined and checked against numerical simulations for the dynamics of a silver nanoparticle. The theoretically predicted diffusive, superdiffusive, and exponentially accelerated dynamical regimes are numerically confirmed.

  5. Determination of the drag resistance coefficients of different vehicles (United States)

    Fahsl, Christoph; Vogt, Patrik


    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient c of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but little attention is paid to quantitative measurements. This experiment was driven by the fact that this physical value is most certainly neglected because of its difficult measurability. In addition to that, this experiment gives insights on how the aerodynamic factor of an automobile affects the energy dissipation and thus how much power is required by automobile transportation.

  6. In Defence of International Comparative Studies. on the Analytical and Explanatory Power of the Nation State in International Comparative Higher Education Research (United States)

    Kosmützky, Anna


    Higher education is undergoing a process of globalization and new realities of a globalized higher education world are emerging. Globalization also has a profound impact on higher education research. Global and transnational topics are theoretically and empirically elaborated and seem on the rise, whereas the international comparative outlook…

  7. On the variability of sea drag in finite water depth (United States)

    Toffoli, A.; Loffredo, L.; Le Roy, P.; LefèVre, J.-M.; Babanin, A. V.


    The coupling between the atmospheric boundary layer and the ocean surface in large-scale models is usually parameterized in terms of the sea drag coefficient, which is routinely estimated as a function of mean wind speed. The scatter of data around such parametric dependencies, however, is very significant and imposes a serious limitation on the forecasts and predictions that make use of sea surface drag parameterizations. The analysis of an atmospheric and wave data set collected in finite water depth at the Lake George measurement site (Australia) suggests that this variability relates to a number of parameters at the air-sea interface other than wind speed alone. In particular, results indicate that the sea drag depends on water depth and wave steepness, which make the wave profile more vertically asymmetric, and the concentration of water vapor in the air, which modifies air density and friction velocity. These dependencies are used to derive parametric functions based on the combined contribution of wind, waves and relative humidity. A standard statistical analysis confirms a substantial improvement in the prediction of the drag coefficient and sea surface roughness when additional parameters are taken into account.

  8. Investigation of drag effect using the field signature method

    International Nuclear Information System (INIS)

    Wan, Zhengjun; Liao, Junbi; Tian, Gui Yun; Cheng, Liang


    The potential drop (PD) method is an established non-destructive evaluation (NDE) technique. The monitoring of internal corrosion, erosion and cracks in piping systems, based on electrical field mapping or direct current potential drop array, is also known as the field signature method (FSM). The FSM has been applied in the field of submarine pipe monitoring and land-based oil and gas transmission pipes and containers. In the experimental studies, to detect and calculate the degree of pipe corrosion, the FSM analyses the relationships between the electrical resistance and pipe thickness using an electrode matrix. The relevant drag effect or trans-resistance will cause a large margin of error in the application of resistance arrays. It is the first time that the drag effect in the paper is investigated and analysed in resistance networks with the help of the FSM. Subsequently, a method to calculate the drag factors and eliminate its errors is proposed and presented. Theoretical analysis, simulation and experimental results show that the measurement accuracy can be improved by eliminating the errors caused by the drag effect

  9. Plasmon-mediated Coulomb drag between graphene waveguides

    DEFF Research Database (Denmark)

    Shylau, Artsem A.; Jauho, Antti-Pekka


    We analyze theoretically charge transport in Coulomb coupled graphene waveguides (GWGs). The GWGs are defined using antidot lattices, and the lateral geometry bypasses many technological challenges of earlier designs. The drag resistivity ρD, which is a measure of the many-particle interactions...

  10. Aerodynamic drag reduction tests on a box-shaped vehicle (United States)

    Peterson, R. L.; Sandlin, D. R.


    The intent of the present experiment is to define a near optimum value of drag coefficient for a high volume type of vehicle through the use of a boattail, on a vehicle already having rounded front corners and an underbody seal, or fairing. The results of these tests will constitute a baseline for later follow-on studies to evaluate candidate methods of obtaining afterbody drag coefficients approaching the boattail values, but without resorting to such impractical afterbody extensions. The current modifications to the box-shaped vehicle consisted of a full and truncated boattail in conjunction with the faired and sealed underbody. Drag results from these configurations are compared with corresponding wind tunnel results of a 1/10 scale model. Test velocities ranged up to 96.6 km/h (60 mph) and the corresponding Reynolds numbers ranged up to 1.3 x 10 to the 7th power based on the vehicles length which includes the boattail. A simple coast-down technique was used to define drag.

  11. Drag power kite with very high lift coefficient

    NARCIS (Netherlands)

    Bauer, F.; Kennel, R.M.; Hackl, C.M.; Campagnolo, F.; Patt, M.; Schmehl, R.


    As an alternative to conventional wind turbines, this study considered kites with onboard wind turbines driven by a high airspeed due to crosswind flight (“drag power”). The hypothesis of this study was, that if the kite's lift coefficient is maximized, then the power, energy yield, allowed costs

  12. Design and performance of the drag-disc turbine transducer

    International Nuclear Information System (INIS)

    Averill, R.H.; Goodrich, L.D.; Ford, R.E.


    Mass flow rates at the Loss-of-Fluid Test (LOFT) facility, EG and G Idaho, Inc., at the Idaho National Engineering Laboratory, are measured with the drag-disc turbine transducer (DTT). Operational description of the DTT and the developmental effort are discussed. Performance data and experiences with this transducer have been evaluated and are presented in this paper

  13. Investigation into the Mechanism of Polymer Thread Drag Reduction (United States)


    They conducted experiments in a 3.75 cm diameter pipe, Re = 85,000, where they injected drag reducing solutions of guar gum and polyacrylamide, P-295 a...manufactured by Dow Chemical. Concentrations of 5000 ppm and 466 ppm based on weight were used in the experiments. The dry powder was suspended in 300

  14. Clock transport synchronisation and the dragging of inertial frames

    International Nuclear Information System (INIS)

    Rosenblum, Arnold


    It is shown that it is possible, by using the lack of synchronisation of clocks by clock transport synchronisation in circular orbits, to test for the dragging of inertial frames in Einstein's theory of general relativity. Possible experiments are discussed. (author)

  15. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya


    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we

  16. Drag Prediction for the NASA CRM Wing-Body-Tail Using CFL3D and OVERFLOW on an Overset Mesh (United States)

    Sclafani, Anthony J.; DeHaan, Mark A.; Vassberg, John C.; Rumsey, Christopher L.; Pulliam, Thomas H.


    In response to the fourth AIAA CFD Drag Prediction Workshop (DPW-IV), the NASA Common Research Model (CRM) wing-body and wing-body-tail configurations are analyzed using the Reynolds-averaged Navier-Stokes (RANS) flow solvers CFL3D and OVERFLOW. Two families of structured, overset grids are built for DPW-IV. Grid Family 1 (GF1) consists of a coarse (7.2 million), medium (16.9 million), fine (56.5 million), and extra-fine (189.4 million) mesh. Grid Family 2 (GF2) is an extension of the first and includes a superfine (714.2 million) and an ultra-fine (2.4 billion) mesh. The medium grid anchors both families with an established build process for accurate cruise drag prediction studies. This base mesh is coarsened and enhanced to form a set of parametrically equivalent grids that increase in size by a factor of roughly 3.4 from one level to the next denser level. Both CFL3D and OVERFLOW are run on GF1 using a consistent numerical approach. Additional OVERFLOW runs are made to study effects of differencing scheme and turbulence model on GF1 and to obtain results for GF2. All CFD results are post-processed using Richardson extrapolation, and approximate grid-converged values of drag are compared. The medium grid is also used to compute a trimmed drag polar for both codes.

  17. Development of a Two-fluid Drag Law for Clustered Particles using Direct Numerical Simulation and Validation through Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gokaltun, Seckin [Florida International Univ., Miami, FL (United States); Munroe, Norman [Florida International Univ., Miami, FL (United States); Subramaniam, Shankar [Iowa State Univ., Ames, IA (United States)


    This study presents a new drag model, based on the cohesive inter-particle forces, implemented in the MFIX code. This new drag model combines an existing standard model in MFIX with a particle-based drag model based on a switching principle. Switches between the models in the computational domain occur where strong particle-to-particle cohesion potential is detected. Three versions of the new model were obtained by using one standard drag model in each version. Later, performance of each version was compared against available experimental data for a fluidized bed, published in the literature and used extensively by other researchers for validation purposes. In our analysis of the results, we first observed that standard models used in this research were incapable of producing closely matching results. Then, we showed for a simple case that a threshold is needed to be set on the solid volume fraction. This modification was applied to avoid non-physical results for the clustering predictions, when governing equation of the solid granular temperate was solved. Later, we used our hybrid technique and observed the capability of our approach in improving the numerical results significantly; however, improvement of the results depended on the threshold of the cohesive index, which was used in the switching procedure. Our results showed that small values of the threshold for the cohesive index could result in significant reduction of the computational error for all the versions of the proposed drag model. In addition, we redesigned an existing circulating fluidized bed (CFB) test facility in order to create validation cases for clustering regime of Geldart A type particles.

  18. Perceptions of Faculty toward Integrating Technology in Undergraduate Higher Education Traditional Classrooms at Research-Focused Regional Universities in South Texas (United States)

    Shipman, Cheri Deann


    This qualitative study examined the perceptions of faculty members who use technology in undergraduate higher education traditional classrooms in research-focused regional universities in South Texas. Faculty members at research-focused regional universities are expected to divide time judiciously into three major areas: research, service, and…

  19. Drag reduction of nata de coco suspensions in circular pipe flow (United States)

    Warashina, J.; Ogata, S.


    Reducing pipe friction by adding a drag-reducing agent has attracted interest as a means to reduce energy consumption. In addition to reducing drag, these agents are required to have a low environmental load and conserve natural resources. However, no drag-reducing agent currently satisfies both these conditions. We focused on nata de coco and found that the nata de coco fiber reduced drag by up to 25%. With respect to the mechanism of drag reduction by nata de coco fiber, the relationship between drag-reduction phenomena and the fiber form of nata de coco was investigated by visualization. We also found that the drag-reduction effect appeared to be due to the formation of networks of tangled fibers of nata de coco. However, drag reduction did not occur in the case in which fibers of nata de coco did not form networks.

  20. An Aerodynamic Database for the Mk 82 General Purpose Low Drag Bomb

    National Research Council Canada - National Science Library

    Krishnamoorthy, L


    The drag database of the Mk 82 General Purpose Low Drag bomb, the primary gravity weapon in the RAAF inventory, has some shortcomings in the quality and traceability of data, and in the variations due...

  1. Quantifying drag on wellbore casings in moving salt sheets (United States)

    Weijermars, R.; Jackson, M. P. A.; Dooley, T. P.


    Frontier hydrocarbon development projects in the deepwater slopes of the Gulf of Mexico Basin, Santos Basin and Lower Congo Basin all require wells to cross ductile layers of autochthonous or allochthonous salt moving at peak rates of 100 mm yr-1. The Couette-Poiseuille number is introduced here to help pinpoint the depth of shear stress reversal in such salt layers. For any well-planned through salt, the probable range of creep forces of moving salt needs to be taken into account when designing safety margins and load-factor tolerance of the well casing. Drag forces increase with wellbore diameter, but more significantly with effective viscosity and speed of the creeping salt layer. The potential drag forces on cased wellbores in moving salt sheets are estimated analytically using a range of salt viscosities (1015-1019 Pa s) and creep rates (0-10 mm yr-1). Drag on perfectly rigid casing of infinite strength may reach up to 13 Giga Newton per meter wellbore length in salt having a viscosity of 1019 Pa s. Well designers may delay stress accumulations due to salt drag when flexible casing accommodates some of the early displacement and strain. However, all creeping salt could displace, fracture and disconnect well casing, eventually. The shear strength of typical heavy duty well casing (about 1000 MPa) can be reached due to drag by moving salt. Internal flow of salt will then fracture the casing near salt entry and exit points, but the structural damage is likely to remain unnoticed early in the well-life when the horizontal shift of the wellbore is still negligibly small (at less than 1 cm yr-1). Disruption of casing and production flow lines within the anticipated service lifetime of a well remains a significant risk factor within distinct zones of low-viscosity salt which may reach ultrafast creep rates of 100 mm yr-1.

  2. Reducing drag of a commuter train, using engine exhaust momentum (United States)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  3. Aeroelastic Modeling of Elastically Shaped Aircraft Concept via Wing Shaping Control for Drag Reduction (United States)

    Nguyen, Nhan; James Urnes, Sr.


    Lightweight aircraft design has received a considerable attention in recent years as a means for improving cruise efficiency. Reducing aircraft weight results in lower lift requirements which directly translate into lower drag, hence reduced engine thrust requirements during cruise. The use of lightweight materials such as advanced composite materials has been adopted by airframe manufacturers in current and future aircraft. Modern lightweight materials can provide less structural rigidity while maintaining load-carrying capacity. As structural flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. Abstract This paper describes a recent aeroelastic modeling effort for an elastically shaped aircraft concept (ESAC). The aircraft model is based on the rigid-body generic transport model (GTM) originally developed at NASA Langley Research Center. The ESAC distinguishes itself from the GTM in that it is equipped with highly flexible wing structures as a weight reduction design feature. More significantly, the wings are outfitted with a novel control effector concept called variable camber continuous trailing edge (VCCTE) flap system for active control of wing aeroelastic deflections to optimize the local angle of attack of wing sections for improved aerodynamic efficiency through cruise drag reduction and lift enhancement during take-off and landing. The VCCTE flap is a multi-functional and aerodynamically efficient device capable of achieving high lift-to-drag ratios. The flap system is comprised of three chordwise segments that form the variable camber feature of the flap and multiple spanwise segments that form a piecewise continuous trailing edge. By configuring the flap camber and trailing edge shape, drag reduction could be


    Directory of Open Access Journals (Sweden)

    Gennady I. Sarantsev


    Full Text Available Introduction: this article continues the discussion of the problems of harmonization of higher education in the direction of “Teacher Education”. The influence of harmonisation on the students learning process. The choice of the magazine “Integration of Education” to highlight the results of the study is due to compliance of his subjects scientific profile of the journal. Materials and Methods: the results of the analysis of the current state of training of the teacher, study the phenomenon of mismatch between the fundamental and practical orientation of vocational education in the direction of “Teacher Education” search means eliminate it, study of modern methodical thinking as a basis for harmonisation of vocational education teacher, presentation of methodical thinking set of professional competences. Methods: modeling, system analysis, activity approach, the interpretation of the provisions of Pedagogy and Psychology in the plane subject methods, concretization of the general provisions to a level guidelines. Results: the main place in training of a teacher is teaching methods. Methodical thinking is an attribute of his professional activity. Professional competencies that embody methodical thinking, constitute the main content of the harmonization of training of the bachelor. Harmonisation of fundamentality and practical orientation of the bachelor makes adjustments to all components of its learning process. Requirements to educational literature, lectures, practical sessions, the main methodological competences, the role and content of the tasks. The training should take the task of simulating real learning situations, which are associated with non-traditional forms of learning. Lectures from means of translating knowledge needs to be transformed into a source of production problems and engage students to research activities, the role of which is amplified and practical training. Discussion and Conclusions: article summarizes

  5. A proposal to Raise the Level of Competitive Advantage of Scientific Research from the Teaching Staff’s Perspective in Higher Education Institutions - the Kingdom of Bahrain

    Directory of Open Access Journals (Sweden)

    Ahmed Noshy Anis ELsherbiny Elbaz


    Full Text Available The study aimed to provide a proposal to raise the level of competitive advantage in scientific research from the teaching staff’s perspective in higher education institutions - in the Kingdom of Bahrain. To achieve this objective, the study used a descriptive method, and a questionnaire as a tool for the field study. In order to determine the mechanisms for achieving competitive advantage in scientific research at the institutions of higher education in the Kingdom of Bahrain, the tool was administered to a sample of (137 faculty members  from some higher education institutions (public and private in the Kingdom of Bahrain. The field study revealed a number of results, inter alia, the study sample agreed with all the proposed mechanisms to achieve competitive advantage in scientific research at institutions of higher education in the Kingdom of Bahrain at a high degree. Their agreement to the themes was in this order: academic support for scientific research, financial support for scientific research, community support for scientific research, and information technology support for scientific research. The study results also showed no statistically significant differences between the responses of the study sample about the proposed mechanisms for achieving competitive advantage in scientific research due to the variables of the academic degree  and the institution. Keywords: Competitive advantage, Research, Higher education institutions.

  6. Oxygen ion uplift and satellite drag effects during the 30 October 2003 daytime superfountain event

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani


    Full Text Available The prompt penetration of interplanetary electric fields (IEFs to the dayside low-latitude ionosphere during the first ~2 h of a superstorm is estimated and applied to a modified NRL SAMI2 code for the 30 October 2003 event. In our simulations, the dayside ionospheric O+ is convected to higher altitudes (~600 km and higher latitudes (~±25° to 30°, forming highly displaced equatorial ionospheric anomaly (EIA peaks. This feature plus others are consistent with previously published CHAMP electron (TEC measurements and with the dayside superfountain model. The rapid upward motion of the O+ ions causes neutral oxygen (O uplift due to ion-neutral drag. It is estimated that above ~400 km altitude the O densities within the displaced EIAs can be increased substantially over quiet time values. The latter feature will cause increased drag for low-altitude satellites. This newly predicted phenomenon is expected to be typical for superstorm/IEF events.

  7. China: A Follower or Leader in Global Higher Education? Research & Occasional Paper Series: CSHE.1.16 (United States)

    van der Wende, Marijk; Zhu, Jiabin


    This paper focuses on China both as an object and a subject in the globalization of higher education and the sometimes paradoxical nature of the country's policies in this respect. How is the Chinese perspective on globalization shaping its agenda for higher education, the development of world-class universities, and cooperation with Europe and…

  8. The Continuing Search to Find a More Effective and Less Intimidating Way to Teach Research Methods in Higher Education (United States)

    Bell, Robin


    Existing literature examining the teaching of research methods highlights difficulties students face when developing research competencies. Studies of student-centred teaching approaches have found increased student performance and improved confidence in undertaking research projects. To develop a student-centred approach, it could be beneficial…

  9. The Drag-based Ensemble Model (DBEM) for Coronal Mass Ejection Propagation (United States)

    Dumbović, Mateja; Čalogović, Jaša; Vršnak, Bojan; Temmer, Manuela; Mays, M. Leila; Veronig, Astrid; Piantschitsch, Isabell


    The drag-based model for heliospheric propagation of coronal mass ejections (CMEs) is a widely used analytical model that can predict CME arrival time and speed at a given heliospheric location. It is based on the assumption that the propagation of CMEs in interplanetary space is solely under the influence of magnetohydrodynamical drag, where CME propagation is determined based on CME initial properties as well as the properties of the ambient solar wind. We present an upgraded version, the drag-based ensemble model (DBEM), that covers ensemble modeling to produce a distribution of possible ICME arrival times and speeds. Multiple runs using uncertainty ranges for the input values can be performed in almost real-time, within a few minutes. This allows us to define the most likely ICME arrival times and speeds, quantify prediction uncertainties, and determine forecast confidence. The performance of the DBEM is evaluated and compared to that of ensemble WSA-ENLIL+Cone model (ENLIL) using the same sample of events. It is found that the mean error is ME = ‑9.7 hr, mean absolute error MAE = 14.3 hr, and root mean square error RMSE = 16.7 hr, which is somewhat higher than, but comparable to ENLIL errors (ME = ‑6.1 hr, MAE = 12.8 hr and RMSE = 14.4 hr). Overall, DBEM and ENLIL show a similar performance. Furthermore, we find that in both models fast CMEs are predicted to arrive earlier than observed, most likely owing to the physical limitations of models, but possibly also related to an overestimation of the CME initial speed for fast CMEs.

  10. The Netherlands, strengthening research in Universities of Applied Sciences: One of twelve case studies produced as part of the project on structural reform in higher education

    NARCIS (Netherlands)

    de Boer, Harry F.


    This study analyses how different types of system-level (or ‘landscape’) structural reforms in higher education have been designed and implemented in selected higher education systems. In the 12 case studies that form the core of the project, the researchers examine reforms aimed at:• Increasing

  11. Moffies, artists, and queens: race and the production of South African gay male drag. (United States)

    Swarr, Amanda Lock


    This article draws on seventeen months of ethnographic fieldwork in South Africa to explore the experiences of urban and township drag performers. I show that two distinct sex-gender-sexuality systems have emerged based in the sociopolitical history of South Africa, and I argue that urban drag produces race oppositionally and examine how township femininity creates raced forms of gender, sex, and sexuality. Contemporary South African drag foregrounds the performativity and constitution of race and gender. My analysis attempts to challenge definitions of "drag" and "audience," suggesting the necessity for an integrated reconceptualization of drag studies.

  12. Experimental Investigation of the Fresnel Drag Effect in RF Coaxial Cables

    Directory of Open Access Journals (Sweden)

    Brotherton D.


    Full Text Available An experiment that confirms the Fresnel drag formalism in RF coaxial cables is reported. The Fresnel "drag" in bulk dielectrics and in optical fibers has previously been well established. An explanation for this formalism is given, and it is shown that there is no actual drag phenomenon, rather that the Fresnel drag effect is merely the consequence of a simplified description of EM scattering within a dielectric in motion wrt the dynamical 3-space. The Fresnel drag effect plays a critical role in the design of various light-speed anisotropy detectors.

  13. The effect of drainage channels on the hydrodynamic drag of non-colloidal spheres down an inclined plane (United States)

    Ryu, Brian; Dhong, Charles; Frechette, Joelle

    While it is well known that surface asperities and roughness alter the hydrodynamic drag of a non-colloidal sphere down an inclined plane, less is known about how the hydrodynamic drag is modified if the asperities and roughness are connected through a network of drainage channels, which allows the movement of fluid between asperities. We investigate the rotational and translation motion of spheres on several pairs of surfaces that have the same porosity and asperity size, but one surface has interconnected drainage channels whereas the other does not. These can have direct relevance to lubricated surfaces such as ball bearings in industrial settings, or biological relevance of leucocyte movement across rough surfaces. Provost's Undergraduate Research Awards, Office of Naval Research, National Science Foundation.

  14. Towards a set of design principles for developing oral presentation competence: A synthesis of research in higher education

    NARCIS (Netherlands)

    Ginkel, van S.O.; Gulikers, J.T.M.; Biemans, H.J.A.; Mulder, M.


    Developing oral presentation competence is an essential objective in higher education. However, a comprehensive picture of effective learning environment characteristics for encouraging oral presentation performance is lacking hitherto. This review identifies and classifies relevant studies with the

  15. Controlling turbulent drag across electrolytes using electric fields. (United States)

    Ostilla-Mónico, Rodolfo; Lee, Alpha A


    Reversible in operando control of friction is an unsolved challenge that is crucial to industrial tribology. Recent studies show that at low sliding velocities, this control can be achieved by applying an electric field across electrolyte lubricants. However, the phenomenology at high sliding velocities is yet unknown. In this paper, we investigate the hydrodynamic friction across electrolytes under shear beyond the transition to turbulence. We develop a novel, highly parallelised numerical method for solving the coupled Navier-Stokes Poisson-Nernst-Planck equation. Our results show that turbulent drag cannot be controlled across dilute electrolytes using static electric fields alone. The limitations of the Poisson-Nernst-Planck formalism hint at ways in which turbulent drag could be controlled using electric fields.

  16. Intershell resistance in multiwall carbon nanotubes: A Coulomb drag study

    DEFF Research Database (Denmark)

    Lunde, Anders Mathias; Flensborg, Karsten; Jauho, Antti-Pekka


    We calculate the intershell resistance R-21 in a multiwall carbon nanotube as a function of temperature T and Fermi level epsilon(F) (e.g., a gate voltage), varying the chirality of the inner and outer tubes. This is done in a so-called Coulomb drag setup, where a current I-1 in one shell induces...... a voltage drop V-2 in another shell by the screened Coulomb interaction between the shells neglecting the intershell tunneling. We provide benchmark results for R-21 = V2/I-1 within the Fermi liquid theory using Boltzmann equations. The band structure gives rise to strongly chirality-dependent suppression...... effects for the Coulomb drag between different tubes due to selection rules combined with mismatching of wave vector and crystal angular momentum conservation near the Fermi level. This gives rise to orders of magnitude changes in R-21 and even the sign of R-21 can change depending on the chirality...

  17. Wave drag reduction due to a self-aligning aerodisk (United States)

    Schnepf, Ch.; Wysocki, O.; Schülein, E.


    The effect of a self-aligning aerodisk on the wave drag of a blunt slender body in a pitching maneuver has been numerically investigated. The self-alignment was realized by a coupling of the flow solver and a flight mechanics tool. The slender body was pitched with high repetition rate between α = 0° and 20° at M = 1.41. Even at high α, the concept could align the aerodisk to the oncoming flow. In comparison to the reference body without a self-aligning aerodisk, a distinct drag reduction is achieved. A comparison with existing experimental data shows a qualitatively good agreement considering the shock and separation structure and the kinematics of the aerodisk.

  18. Bioinspired superhydrophobic, self-cleaning and low drag surfaces (United States)

    Bhushan, Bharat


    Nature has evolved objects with desired functionality using commonly found materials. Nature capitalizes on hierarchical structures to achieve functionality. The understanding of the functions provided by objects and processes found in nature can guide us to produce nanomaterials, nanodevices, and processes with desirable functionality. This article provides an overview of four topics: (1) Lotus Effect used to develop superhydrophobic and self-cleaning/antifouling surfaces with low adhesion, (2) Shark Skin Effect to develop surfaces with low fluid drag and anti-fouling characteristics, and (3-4) Rice Leaf and Butterfly Wing Effect to develop superhydrophobic and self-cleaning surfaces with low drag. Rice Leaf and Butterfly Wings combine the Shark Skin and Lotus Effects.

  19. Collisionless ion drag force on a spherical grain

    International Nuclear Information System (INIS)

    Hutchinson, I H


    The ion drag force on a spherical grain situated in a flowing collisionless plasma is obtained from the specialized coordinate electrostatic particle and thermals in cell simulation code (SCEPTIC) (Hutchinson 2002 Plasma Phys. Control. Fusion 44 1953, Hutchinson 2003 Plasma Phys. Control. Fusion 45 1477, Hutchinson 2005 Plasma Phys. Control. Fusion 47 71) and compared with recent analytic approximate treatments in the interesting and relevant case when the Debye length is only moderately larger than the sphere radius. There is a substantial complex structure in the results for transonic flows, which is explained in terms of the details of ion orbits. Naturally the prior analytic approximations miss this structure, and as a result they seriously underestimate the drag for speeds near the sound speed. An easy-to-evaluate expression for force is provided that fits the comprehensive results of the code. This expression, with minor modification, also fits the results even for Debye length much smaller than the sphere radius

  20. Drag reduction by dimples? - A complementary experimental/numerical investigation

    International Nuclear Information System (INIS)

    Lienhart, Hermann; Breuer, Michael; Koeksoy, Cagatay


    The paper is concerned with an experimental and numerical investigation of the turbulent flow over dimpled surfaces. Shallow dimples distributed regularly over the wall of a plane channel with large aspect ratio are used to study their effect on the friction drag. The resulting pressure drop in the channel was measured for smooth and dimpled walls. In addition to these investigations on internal flows, an external flow study was performed and boundary-layer profiles were measured using a Pitot-tube rake. Complementary to the measurements, direct numerical simulations for the internal flow configuration with and without dimples were carried out for two different grid resolutions and analyzed in detail. The objective was to clarify whether or not dimples cause reduction of the skin-friction drag

  1. Suboptimal control for drag reduction in turbulent pipe flow

    International Nuclear Information System (INIS)

    Choi, Jung Il; Sung, Hyung Jin; Xu, Chun Xiao


    A suboptimal control law in turbulent pipe flow is derived and tested. Two sensing variables ∂ρ/∂θ / w and ∂ν θ /∂r / w are applied with two actuations φ θ and φ γ . To test the suboptimal control law, direct numerical simulations of turbulent pipe flow at Re τ =150 are performed. When the control law is applied, a 13∼23% drag reduction is achieved. The most effective drag reduction is made at the pair of ∂υ θ /∂r / w and φ γ . An impenetrable virtual wall concept is useful for analyzing the near-wall suction and blowing. The virtual wall concept is useful for analyzing the near-wall behavior of the controlled flow. Comparison of the present suboptimal control with that of turbulent channel flow reveals that the curvature effect is insignificant

  2. Simultaneous drag and flow measurements of Olympic skeleton athletes (United States)

    Moon, Yae Eun; Digiulio, David; Peters, Steve; Wei, Timothy


    The Olympic sport of skeleton involves an athlete riding a small sled face first down a bobsled track at speeds up to 130 km/hr. In these races, the difference between gold and missing the medal stand altogether can be hundredths of a second per run. As such, reducing aerodynamic drag through proper body positioning is of first order importance. To better study the flow behavior and to improve the performance of the athletes, we constructed a static force balance system on a mock section of a bobsled track. Athlete and the sled are placed on the force balance system which is positioned at the exit of an open loop wind tunnel. Simultaneous drag force and DPIV velocity field measurements were made along with video recordings of body position to aid the athletes in determining their optimal aerodynamic body position.

  3. Physics and control of wall turbulence for drag reduction. (United States)

    Kim, John


    Turbulence physics responsible for high skin-friction drag in turbulent boundary layers is first reviewed. A self-sustaining process of near-wall turbulence structures is then discussed from the perspective of controlling this process for the purpose of skin-friction drag reduction. After recognizing that key parts of this self-sustaining process are linear, a linear systems approach to boundary-layer control is discussed. It is shown that singular-value decomposition analysis of the linear system allows us to examine different approaches to boundary-layer control without carrying out the expensive nonlinear simulations. Results from the linear analysis are consistent with those observed in full nonlinear simulations, thus demonstrating the validity of the linear analysis. Finally, fundamental performance limit expected of optimal control input is discussed.

  4. Reducing Aerodynamic Drag on Empty Open Cargo Vehicles (United States)

    Ross, James C.; Storms, Bruce L.; Dzoan, Dan


    Some simple structural modifications have been demonstrated to be effective in reducing aerodynamic drag on vehicles that have empty open cargo bays. The basic idea is to break up the airflow in a large open cargo bay by inserting panels to divide the bay into a series of smaller bays. In the case of a coal car, this involves inserting a small number (typically between two and four) of vertical full-depth or partial-depth panels.

  5. The effects of Poynting-Robertson drag on solar sails (United States)

    Abd El-Salam, F. A.


    In the present work, the concept of solar sailing and its developing spacecraft are presented. The effects of Poynting-Robertson drag on solar sails are considered. Some analytical control laws with some mentioned input constraints for optimizing solar sails dynamics in heliocentric orbit using Lagrange's planetary equations are obtained. Optimum force vector in a required direction is maximized by deriving optimal sail cone angle. New control laws that maximize thrust to obtain certain required maximization in some particular orbital element are obtained.

  6. Stokes’ and Lamb's viscous drag laws

    International Nuclear Information System (INIS)

    Eames, I; Klettner, C A


    Since Galileo used his pulse to measure the time period of a swinging chandelier in the 17th century, pendulums have fascinated scientists. It was not until Stokes' (1851 Camb. Phil. Soc. 9 8–106) (whose interest was spurred by the pendulur time pieces of the mid 19th century) treatise on viscous flow that a theoretical framework for the drag on a sphere at low Reynolds number was laid down. Stokes' famous drag law has been used to determine two fundamental physical constants—the charge on an electron and Avogadro's constant—and has been used in theories which have won three Nobel prizes. Considering its illustrious history it is then not surprising that the flow past a sphere and its two-dimensional analog, the flow past a cylinder, form the starting point of teaching flow past a rigid body in undergraduate level fluid mechanics courses. Usually starting with the two-dimensional potential flow past a cylinder, students progress to the three-dimensional potential flow past a sphere. However, when the viscous flow past rigid bodies is taught, the three-dimensional example of a sphere is first introduced, and followed by (but not often), the two-dimensional viscous flow past a cylinder. The reason why viscous flow past a cylinder is generally not taught is because it is usually explained from an asymptotic analysis perspective. In fact, this added mathematical complexity is why the drag on a cylinder was only solved in 1911, 60 years after the drag on a sphere. In this note, we show that the viscous flow past a cylinder can be explained without the need to introduce any asymptotic analysis while still capturing all the physical insight of this classic fluid mechanics problem. (paper)

  7. Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

    Directory of Open Access Journals (Sweden)

    Bharat Bhushan


    Full Text Available The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab.

  8. The influence of numerical models on determining the drag coefficient

    Directory of Open Access Journals (Sweden)

    Dobeš Josef


    Full Text Available The paper deals with numerical modelling of body aerodynamic drag coefficient in the transition from laminar to turbulent flow regimes, where the selection of a suitable numerical model is problematic. On the basic problem of flow around a simple body – sphere selected computational models are tested. The values obtained by numerical simulations of drag coefficients of each model are compared with the graph of dependency of the drag coefficient vs. Reynolds number for a sphere. Next the dependency of Strouhal number vs. Reynolds number is evaluated, where the vortex shedding frequency values for given speed are obtained numerically and experimentally and then the values are compared for each numerical model and experiment. The aim is to specify trends for the selection of appropriate numerical model for flow around bodies problem in which the precise description of the flow field around the obstacle is used to define the acoustic noise source. Numerical modelling is performed by finite volume method using CFD code.

  9. Drag reduction: enticing turbulence, and then an industry. (United States)

    Spalart, Philippe R; McLean, J Douglas


    We examine drag-reduction proposals, as presented in this volume and in general, first with concrete examples of how to bridge the distance from pure science through engineering to what makes inventions go into service; namely, the value to the public. We point out that the true drag reduction can be markedly different from an estimate based simply on the difference between turbulent and laminar skin friction over the laminarized region, or between the respective skin frictions of the baseline and the riblet-treated flow. In some situations, this difference is favourable, and is due to secondary differences in pressure drag. We reiterate that the benefit of riblets, if it is expressed as a percentage in skin-friction reduction, is unfortunately lower at full-size Reynolds numbers than in a small-scale experiment or simulation. The Reynolds number-independent measure of such benefits is a shift of the logarithmic law, or 'ΔU(+)'. Anticipating the design of a flight test and then a product, we note the relative ease in representing riblets or laminarization in computational fluid dynamics, in contrast with the huge numerical and turbulence-modelling challenge of resolving active flow control systems in a calculation of the full flow field. We discuss in general terms the practical factors that have limited applications of concepts that would appear more than ready after all these years, particularly riblets and laminar-flow control.

  10. Drag reduction of a reverse-engineered vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Lecrivain, G.; Slaouti, A.; Kennedy, I. [Manchester Metropolitan Univ., Manchester (United Kingdom). Dept. of Engineering and Technology


    The aerodynamic performance of a hand-made sports car was numerically assessed using computational fluid dynamics (CFD) analysis of various shape modifications. The purpose was to achieve a lower drag design. Reverse-engineering was used to create a virtual model of complex 3D shapes for which no computer-aided drawings (CAD) data existed. From the predicted flow, the body could be redesigned for better performance prior to its remanufacturing. This paper described the multidisciplinary procedure involving reverse-engineering and CAD that was used to recreate a suitable watertight model of the sports car. The different errors embedded in the successive stages leading to the final model were accurately assessed and minimized. The whole vehicle was remodelled for drag reduction. Surface reconstruction was carried out, an an accurate set of high quality Non-Uniform Rational B-Spline (NURBS) surfaces was produced over the polygonal mesh resulting in a fine visual surface finish with smooth lines and contours, as required in the automotive industry. Further modifications were implemented for the purpose of drag reduction and to improve its aerodynamic performance. The application described in this paper can be extended to any other similarly intricate vehicle or industrial component. 12 refs., 1 tab., 11 figs.

  11. Aerodynamic drag control by pulsed jets on simplified car geometry (United States)

    Gilliéron, Patrick; Kourta, Azeddine


    Aerodynamic drag control by pulsed jets is tested in a wind tunnel around a simplified car geometry named Ahmed body with a rear slant angle of 35°. Pulsed jet actuators are located 5 × 10-3 m from the top of the rear window. These actuators are produced by a pressure difference ranging from 1.5 to 6.5 × 105 Pa. Their excitation frequency can vary between 10 and 550 Hz. The analysis of the control effects is based on wall visualizations, aerodynamic drag coefficient measurements, and the velocity fields obtained by 2D PIV measurements. The maximum drag reduction is 20 % and is obtained for the excitation frequency F j = 500 Hz and for the pressure difference ∆ P = 1.5 × 105 Pa. This result is linked with a substantial reduction in the transverse development of the longitudinal vortex structures coming from the left and right lateral sides of the rear window, with a displacement of the vortex centers downstream and with a decrease in the transverse rotational absolute values of these structures.

  12. The elaborate plumage in peacocks is not such a drag. (United States)

    Askew, Graham N


    One of the classic examples of an exaggerated sexually selected trait is the elaborate plumage that forms the train in male peafowl Pavo cristatus (peacock). Such ornaments are thought to reduce locomotor performance as a result of their weight and aerodynamic drag, but this cost is unknown. Here, the effect that the train has on take-off flight in peacocks was quantified as the sum of the rates of change of the potential and kinetic energies of the body (P(CoM)) in birds with trains and following the train's removal. There was no significant difference between P(CoM) in birds with and without a train. The train incurs drag during take-off; however, while this produces a twofold increase in parasite drag, parasite power only accounts for 0.1% of the total aerodynamic power. The train represented 6.9% of body weight and is expected to increase induced power. The absence of a detectable effect on take-off performance does not necessarily mean that there is no cost associated with possessing such ornate plumage; rather, it suggests that given the variation in take-off performance per se, the magnitude of any effect of the train has little meaningful functional relevance. © 2014. Published by The Company of Biologists Ltd.

  13. Coordination of multiple appendages in drag-based swimming. (United States)

    Alben, Silas; Spears, Kevin; Garth, Stephen; Murphy, David; Yen, Jeannette


    Krill are aquatic crustaceans that engage in long distance migrations, either vertically in the water column or horizontally for 10 km (over 200,000 body lengths) per day. Hence efficient locomotory performance is crucial for their survival. We study the swimming kinematics of krill using a combination of experiment and analysis. We quantify the propulsor kinematics for tethered and freely swimming krill in experiments, and find kinematics that are very nearly metachronal. We then formulate a drag coefficient model which compares metachronal, synchronous and intermediate motions for a freely swimming body with two legs. With fixed leg velocity amplitude, metachronal kinematics give the highest average body speed for both linear and quadratic drag laws. The same result holds for five legs with the quadratic drag law. When metachronal kinematics is perturbed towards synchronous kinematics, an analysis shows that the velocity increase on the power stroke is outweighed by the velocity decrease on the recovery stroke. With fixed time-averaged work done by the legs, metachronal kinematics again gives the highest average body speed, although the advantage over synchronous kinematics is reduced.

  14. Perturbed Partial Cavity Drag Reduction at High Reynolds Numbers (United States)

    Makiharju, Simo; Elbing, Brian; Wiggins, Andrew; Dowling, David; Perlin, Marc; Ceccio, Steven


    Ventilated partial cavities were investigated at Reynolds numbers to 80 million. These cavities could be suitable for friction drag reduction on ocean going vessels and thereby lead to environmental and economical benefits. The test model was a 3.05 m wide by 12.9 m long flat plate, with a 0.18 m backward-facing step and a cavity-terminating beach, which had an adjustable slope, tilt and height. The step and beach trapped a ventilated partial cavity over the longitudinal mid-section of the model. Large-scale flow perturbations, mimicking the effect of ambient ocean waves were investigated. For the conditions tested a cavity could be maintained under perturbed flow conditions when the gas flux supplied was greater than the minimum required to maintain a cavity under steady conditions, with larger perturbations requiring more excess gas flux to maintain the cavity. High-speed video was used to observe the unsteady three dimensional cavity closure, the overall cavity shape, and the cavity oscillations. Cavities with friction drag reduction exceeding 95% were attained at optimal conditions. A simplified energy cost-benefit analysis of partial cavity drag reduction was also performed. The results suggest that PCDR could potentially lead to energy savings.

  15. Re-Envisioning Instructional Technology Research in Higher Education Environments: A Content Analysis of a Grant Program (United States)

    Paulus, Trena M.; Phipps, Gina; Harrison, John; Varga, Mary Alice


    Within the field of instructional technology, scholars have long worked to define the scope and purpose of research and its role in informing practice. Increasingly, researchers outside of the instructional technology field are conducting studies to examine their use of technology in educational contexts. Few studies have been done on how…

  16. The Effects of Different Teaching, Research, and Service Emphases on Individual and Organizational Outcomes in Higher Education Institutions (United States)

    Terpstra, David E.; Honoree, Andre L.


    The authors investigated the relative emphasis that educators give to teaching, research, and service in the business discipline and 4 other academic disciplines. The authors also investigated the effects of different faculty activity emphases on faculty teaching effectiveness, research performance, service levels, job and pay satisfaction,…


    Directory of Open Access Journals (Sweden)

    Pavel E. Shenderey


    Full Text Available Modern researches show that intersubject communications atinitial stages of their inclusion in cognitive activity of studentsplay a role of the situational starting, inducing incentive. The knowledge gained by students as a result of the previousexperience of assimilation of intersubject communicationsbecomes regulators of its informa-tive activity at any stage ofinclusion of intersubject communications in cognitive activityand developments of research competence.

  18. Understanding the role of organizational factors in shaping the research careers of women academics in higher education

    Directory of Open Access Journals (Sweden)

    Georgeta Ion


    Full Text Available This paper represents an attempt to make a theoretical contribution to its knowledge base through an analysis of the group factors which contribute to the success of women academics engaged in research within the area of social sciences. The data were obtained through a series of in-depth interviews carried out at public universities in Catalonia, with women academics –all of whom were the heads of research groups recognized by the Generalitat [Regional Government] of Catalonia. The findings indicate that research groups provide a supportive and effective environment for female researchers enabling them to develop their academic careers, as measured by such key performance indicators as the number of publications and successful applications for research funding.

  19. Mid-Lift-to-Drag Ratio Rigid Vehicle Control System Design and Simulation for Human Mars Entry (United States)

    Johnson, Breanna J.; Cerimele, Christopher J.; Stachowiak, Susan J.; Sostaric, Ronald R.; Matz, Daniel A.; Lu, Ping


    The Mid-Lift-to-Drag Ratio Rigid Vehicle (MRV) is a proposed candidate in the NASA Evolvable Mars Campaign's (EMC) Pathfinder Entry, Descent, and Landing (EDL) architecture study. The purpose of the study is to design a mission and vehicle capable of transporting a 20mt payload to the surface of Mars. The MRV is unique in its rigid, asymmetrical lifting-body shape which enables a higher lift-to-drag ratio (L/D) than the typical robotic Mars entry capsule vehicles that carry much less mass. This paper presents the formulation and six-degree-of-freedom (6DOF) performance of the MRV's control system, which uses both aerosurfaces and a propulsive reaction control system (RCS) to affect longitudinal and lateral directional behavior.

  20. Research on the integration of teaching content of core courses in Agro-ecological environmental specialties of higher vocational colleges (United States)

    Chen, Juan; Ma, Guosheng


    Curriculum is the means to cultivate higher vocational talents. On the basis of analyzing the core curriculum problems of curriculum reform and Agro-ecological environmental specialties in higher vocational colleges, this paper puts forward the optimization and integration measures of 6 core courses, including “Eco-environment Repair Technology”, “Agro-environmental Management Plan”, “Environmental Engineering Design”, “Environmental Pest Management Technology”, “Agro-chemical Pollution Control Technology”, “Agro-environmental Testing and Analysis”. It integrates the vocational qualification certificate education and professional induction certificate training items, and enhances the adaptability, skills and professionalism of professional core curriculum.