76 FR 8358 - Basic Energy Sciences Advisory Committee

Science.gov (United States)

2011-02-14

... DEPARTMENT OF ENERGY Basic Energy Sciences Advisory Committee AGENCY: Department of Energy, Office of Science. ACTION: Notice of open meeting. SUMMARY: This notice announces a meeting of the Basic Energy Sciences Advisory Committee (BESAC). Federal Advisory Committee Act (Pub. L. 92- 463, 86 Stat. 770...

The use of simulation in teaching the basic sciences.

Science.gov (United States)

Eason, Martin P

2013-12-01

To assess the current use of simulation in medical education, specifically, the teaching of the basic sciences to accomplish the goal of improved integration. Simulation is increasingly being used by the institutions to teach the basic sciences. Preliminary data suggest that it is an effective tool with increased retention and learner satisfaction. Medical education is undergoing tremendous change. One of the directions of that change is increasing integration of the basic and clinical sciences to improve the efficiency and quality of medical education, and ultimately to improve the patient care. Integration is thought to improve the understanding of basic science conceptual knowledge and to better prepare the learners for clinical practice. Simulation because of its unique effects on learning is currently being successfully used by many institutions as a means to produce that integration through its use in the teaching of the basic sciences. Preliminary data indicate that simulation is an effective tool for basic science education and garners high learner satisfaction.

Back to the basic sciences: an innovative approach to teaching senior medical students how best to integrate basic science and clinical medicine.

Science.gov (United States)

Spencer, Abby L; Brosenitsch, Teresa; Levine, Arthur S; Kanter, Steven L

2008-07-01

Abraham Flexner persuaded the medical establishment of his time that teaching the sciences, from basic to clinical, should be a critical component of the medical student curriculum, thus giving rise to the "preclinical curriculum." However, students' retention of basic science material after the preclinical years is generally poor. The authors believe that revisiting the basic sciences in the fourth year can enhance understanding of clinical medicine and further students' understanding of how the two fields integrate. With this in mind, a return to the basic sciences during the fourth year of medical school may be highly beneficial. The purpose of this article is to (1) discuss efforts to integrate basic science into the clinical years of medical student education throughout the United States and Canada, and (2) describe the highly developed fourth-year basic science integration program at the University of Pittsburgh School of Medicine. In their critical review of medical school curricula of 126 U.S. and 17 Canadian medical schools, the authors found that only 19% of U.S. medical schools and 24% of Canadian medical schools require basic science courses or experiences during the clinical years, a minor increase compared with 1985. Curricular methods ranged from simple lectures to integrated case studies with hands-on laboratory experience. The authors hope to advance the national discussion about the need to more fully integrate basic science teaching throughout all four years of the medical student curriculum by placing a curricular innovation in the context of similar efforts by other U.S. and Canadian medical schools.

Basic Sciences Fertilizing Clinical Microbiology and Infection Management.

Science.gov (United States)

Baquero, Fernando

2017-08-15

Basic sciences constitute the most abundant sources of creativity and innovation, as they are based on the passion of knowing. Basic knowledge, in close and fertile contact with medical and public health needs, produces distinct advancements in applied sciences. Basic sciences play the role of stem cells, providing material and semantics to construct differentiated tissues and organisms and enabling specialized functions and applications. However, eventually processes of "practice deconstruction" might reveal basic questions, as in de-differentiation of tissue cells. Basic sciences, microbiology, infectious diseases, and public health constitute an epistemological gradient that should also be an investigational continuum. The coexistence of all these interests and their cross-fertilization should be favored by interdisciplinary, integrative research organizations working simultaneously in the analytical and synthetic dimensions of scientific knowledge. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Integration of basic sciences and clinical sciences in oral radiology education for dental students.

Science.gov (United States)

Baghdady, Mariam T; Carnahan, Heather; Lam, Ernest W N; Woods, Nicole N

2013-06-01

Educational research suggests that cognitive processing in diagnostic radiology requires a solid foundation in the basic sciences and knowledge of the radiological changes associated with disease. Although it is generally assumed that dental students must acquire both sets of knowledge, little is known about the most effective way to teach them. Currently, the basic and clinical sciences are taught separately. This study was conducted to compare the diagnostic accuracy of students when taught basic sciences segregated or integrated with clinical features. Predoctoral dental students (n=51) were taught four confusable intrabony abnormalities using basic science descriptions integrated with the radiographic features or taught segregated from the radiographic features. The students were tested with diagnostic images, and memory tests were performed immediately after learning and one week later. On immediate and delayed testing, participants in the integrated basic science group outperformed those from the segregated group. A main effect of learning condition was found to be significant (pbasic sciences integrated with clinical features produces higher diagnostic accuracy in novices than teaching basic sciences segregated from clinical features.

Dynamic wake meandering modeling

Energy Technology Data Exchange (ETDEWEB)

Larsen, Gunner C.; Aagaard Madsen, H.; Bingoel, F. (and others)

2007-06-15

We present a consistent, physically based theory for the wake meandering phenomenon, which we consider of crucial importance for the overall description of wind turbine loadings in wind farms. In its present version the model is confined to single wake situations. The model philosophy does, however, have the potential to include also mutual wake interaction phenomenons. The basic conjecture behind the dynamic wake meandering model is that wake transportation in the atmospheric boundary layer is driven by the large scale lateral- and vertical turbulence components. Based on this conjecture a stochastic model of the downstream wake meandering is formulated. In addition to the kinematic formulation of the dynamics of the 'meandering frame of reference', models characterizing the mean wake deficit as well as the added wake turbulence, described in the meandering frame of reference, are an integrated part the model complex. For design applications, the computational efficiency of wake deficit prediction is a key issue. Two computationally low cost models are developed for this purpose. The character of the added wake turbulence, generated by the up-stream turbine in the form of shed and trailed vorticity, has been approached by analytical as well as by numerical studies. The dynamic wake meandering philosophy has been verified by comparing model predictions with extensive full-scale measurements. These comparisons have demonstrated good agreement, both qualitatively and quantitatively, concerning both flow characteristics and turbine load characteristics. Contrary to previous attempts to model wake loading, the dynamic wake meandering approach opens for a unifying description in the sense that turbine power and load aspects can be treated simultaneously. This capability is a direct and attractive consequence of the model being based on the underlying physical process, and it potentially opens for optimization of wind farm topology, of wind farm operation as

Emulsion Science Basic Principles

CERN Document Server

Leal-Calderon, Fernando; Schmitt, Véronique

2007-01-01

Emulsions are generally made out of two immiscible fluids like oil and water, one being dispersed in the second in the presence of surface-active compounds.They are used as intermediate or end products in a huge range of areas including the food, chemical, cosmetic, pharmaceutical, paint, and coating industries. Besides the broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physics and chemistry. This book aims to give an overview of the most recent advances in emulsion science. The basic principles, covering aspects of emulsions from their preparation to their destruction, are presented in close relation to both the fundamental physics and the applications of these materials. The book is intended to help scientists and engineers in formulating new materials by giving them the basics of emulsion science.

Wake modeling and simulation

Energy Technology Data Exchange (ETDEWEB)

Larsen, G.C.; Aagaard Madsen, H.; Larsen, T.J.; Troldborg, N.

2008-07-15

We present a consistent, physically based theory for the wake meandering phenomenon, which we consider of crucial importance for the overall description of wind turbine loadings in wind farms. In its present version the model is confined to single wake situations. The model philosophy does, however, have the potential to include also mutual wake interaction phenomenons. The basic conjecture behind the dynamic wake meandering (DWM) model is that wake transportation in the atmospheric boundary layer is driven by the large scale lateral- and vertical turbulence components. Based on this conjecture a stochastic model of the downstream wake meandering is formulated. In addition to the kinematic formulation of the dynamics of the 'meandering frame of reference', models characterizing the mean wake deficit as well as the added wake turbulence, described in the meandering frame of reference, are an integrated part the DWM model complex. For design applications, the computational efficiency of wake deficit prediction is a key issue. A computationally low cost model is developed for this purpose. Likewise, the character of the added wake turbulence, generated by the up-stream turbine in the form of shed and trailed vorticity, has been approached by a simple semi-empirical model essentially based on an eddy viscosity philosophy. Contrary to previous attempts to model wake loading, the DWM approach opens for a unifying description in the sense that turbine power- and load aspects can be treated simultaneously. This capability is a direct and attractive consequence of the model being based on the underlying physical process, and it potentially opens for optimization of wind farm topology, of wind farm operation as well as of control strategies for the individual turbine. To establish an integrated modeling tool, the DWM methodology has been implemented in the aeroelastic code HAWC2, and example simulations of wake situations, from the small Tjaereborg wind farm, have

Integration and timing of basic and clinical sciences education.

Science.gov (United States)

Bandiera, Glen; Boucher, Andree; Neville, Alan; Kuper, Ayelet; Hodges, Brian

2013-05-01

Medical education has traditionally been compartmentalized into basic and clinical sciences, with the latter being viewed as the skillful application of the former. Over time, the relevance of basic sciences has become defined by their role in supporting clinical problem solving rather than being, of themselves, a defining knowledge base of physicians. As part of the national Future of Medical Education in Canada (FMEC MD) project, a comprehensive empirical environmental scan identified the timing and integration of basic sciences as a key pressing issue for medical education. Using the literature review, key informant interviews, stakeholder meetings, and subsequent consultation forums from the FMEC project, this paper details the empirical basis for focusing on the role of basic science, the evidentiary foundations for current practices, and the implications for medical education. Despite a dearth of definitive relevant studies, opinions about how best to integrate the sciences remain strong. Resource allocation, political power, educational philosophy, and the shift from a knowledge-based to a problem-solving profession all influence the debate. There was little disagreement that both sciences are important, that many traditional models emphasized deep understanding of limited basic science disciplines at the expense of other relevant content such as social sciences, or that teaching the sciences contemporaneously rather than sequentially has theoretical and practical merit. Innovations in integrated curriculum design have occurred internationally. Less clear are the appropriate balance of the sciences, the best integration model, and solutions to the political and practical challenges of integrated curricula. New curricula tend to emphasize integration, development of more diverse physician competencies, and preparation of physicians to adapt to evolving technology and patients' expectations. Refocusing the basic/clinical dichotomy to a foundational

Basic Principles of Animal Science. Reprinted.

Science.gov (United States)

Florida State Dept. of Education, Tallahassee.

The reference book is designed to fulfill the need for organized subject matter dealing with basic principles of animal science to be incorporated into the high school agriculture curriculum. The material presented is scientific knowledge basic to livestock production. Five units contain specific information on the following topics: anatomy and…

Review of Idealized Aircraft Wake Vortex Models

Science.gov (United States)

Ahmad, Nashat N.; Proctor, Fred H.; Duparcmeur, Fanny M. Limon; Jacob, Don

2014-01-01

Properties of three aircraft wake vortex models, Lamb-Oseen, Burnham-Hallock, and Proctor are reviewed. These idealized models are often used to initialize the aircraft wake vortex pair in large eddy simulations and in wake encounter hazard models, as well as to define matched filters for processing lidar observations of aircraft wake vortices. Basic parameters for each vortex model, such as peak tangential velocity and circulation strength as a function of vortex core radius size, are examined. The models are also compared using different vortex characterizations, such as the vorticity magnitude. Results of Euler and large eddy simulations are presented. The application of vortex models in the postprocessing of lidar observations is discussed.

Horizontal integration of the basic sciences in the chiropractic curriculum.

Science.gov (United States)

Ward, Kevin P

2010-01-01

Basic science curricula at most chiropractic colleges consist of courses (eg, general anatomy, physiology, biochemistry, etc) that are taught as stand-alone content domains. The lack of integration between basic science disciplines causes difficulties for students who need to understand how the parts function together as an integrated whole and apply this understanding to solving clinical problems. More horizontally integrated basic science curricula could be achieved by several means: integrated Part I National Board of Chiropractic Examiners questions, a broader education for future professors, an increased emphasis on integration within the current model, linked courses, and an integrated, thematic basic science curriculum. Horizontally integrating basic science curricula would require significant efforts from administrators, curriculum committees, and instructional faculty. Once in place this curriculum would promote more clinically relevant learning, improved learning outcomes, and superior vertical integration.

Horizontal Integration of the Basic Sciences in the Chiropractic Curriculum

Science.gov (United States)

Ward, Kevin P.

2010-01-01

Basic science curricula at most chiropractic colleges consist of courses (eg, general anatomy, physiology, biochemistry, etc) that are taught as stand-alone content domains. The lack of integration between basic science disciplines causes difficulties for students who need to understand how the parts function together as an integrated whole and apply this understanding to solving clinical problems. More horizontally integrated basic science curricula could be achieved by several means: integrated Part I National Board of Chiropractic Examiners questions, a broader education for future professors, an increased emphasis on integration within the current model, linked courses, and an integrated, thematic basic science curriculum. Horizontally integrating basic science curricula would require significant efforts from administrators, curriculum committees, and instructional faculty. Once in place this curriculum would promote more clinically relevant learning, improved learning outcomes, and superior vertical integration. PMID:21048882

Basic mathematics for the biological and social sciences

CERN Document Server

Marriott, F H C

2013-01-01

Basic Mathematics for the Biological and Social Sciences deals with the applications of basic mathematics in the biological and social sciences. Mathematical concepts that are discussed in this book include graphical methods, differentiation, trigonometrical or circular functions, limits and convergence, integration, vectors, and differential equations. The exponential function and related functions are also considered. This monograph is comprised of 11 chapters and begins with an overview of basic algebra, followed by an introduction to infinitesimal calculus, scalar and vector quantities, co

Simulation of wind turbine wakes using the actuator line technique

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming; Henningson, Dan S.

2015-01-01

The actuator line technique was introduced as a numerical tool to be employed in combination with large eddy simulations to enable the study of wakes and wake interaction in wind farms. The technique is today largely used for studying basic features of wakes as well as for making performance...... predictions of wind farms. In this paper, we give a short introduction to the wake problem and the actuator line methodology and present a study in which the technique is employed to determine the near-wake properties of wind turbines. The presented results include a comparison of experimental results...

Exploring Attractiveness of the Basic Sciences for Female Physicians.

Science.gov (United States)

Yamazaki, Yuka; Fukushima, Shinji; Kozono, Yuki; Uka, Takanori; Marui, Eiji

2018-01-01

In Japan, traditional gender roles of women, especially the role of motherhood, may cause early career resignations in female physicians and a shortage of female researchers. Besides this gender issue, a general physician shortage is affecting basic science fields. Our previous study suggested that female physicians could be good candidates for the basic sciences because such work offers good work-life balance. However, the attractiveness for female physicians of working in the basic sciences, including work-life balance, is not known. In a 2012 nationwide cross-sectional questionnaire survey, female physicians holding tenured positions in the basic sciences at Japan's medical schools were asked an open-ended question about positive aspects of basic sciences that clinical medicine lacks, and we analyzed 58 respondents' comments. Qualitative analysis using the Kawakita Jiro method revealed four positive aspects: research attractiveness, priority on research productivity, a healthy work-life balance, and exemption from clinical duties. The most consistent positive aspect was research attractiveness, which was heightened by medical knowledge and clinical experience. The other aspects were double-edged swords; for example, while the priority on research productivity resulted in less gender segregation, it sometimes created tough competition, and while exemption from clinical duties contributed to a healthy work-life balance, it sometimes lowered motivation as a physician and provided unstable income. Overall, if female physicians lack an intrinsic interest in research and seek good work-life balance, they may drop out of research fields. Respecting and cultivating students' research interest is critical to alleviating the physician shortage in the basic sciences.

Trends in Basic Sciences Education in Dental Schools, 1999-2016.

Science.gov (United States)

Lantz, Marilyn S; Shuler, Charles F

2017-08-01

The purpose of this study was to examine data published over the past two decades to identify trends in the basic sciences curriculum in dental education, provide an analysis of those trends, and compare them with trends in the basic sciences curriculum in medical education. Data published from the American Dental Association (ADA) Surveys of Dental Education, American Dental Education Association (ADEA) Surveys of Dental School Seniors, and two additional surveys were examined. In large part, survey data collected focused on the structure, content, and instructional strategies used in dental education: what was taught and how. Great variability was noted in the total clock hours of instruction and the clock hours of basic sciences instruction reported by dental schools. Moreover, the participation of medical schools in the basic sciences education of dental students appears to have decreased dramatically over the past decade. Although modest progress has been made in implementing some of the curriculum changes recommended in the 1995 Institute of Medicine report such as integrated basic and clinical sciences curricula, adoption of active learning methods, and closer engagement with medical and other health professions education programs, educational effectiveness studies needed to generate data to support evidence-based approaches to curriculum reform are lacking. Overall, trends in the basic sciences curriculum in medical education were similar to those for dental education. Potential drivers of curriculum change were identified, as was recent work in other fields that should encourage reconsideration of dentistry's approach to basic sciences education. This article was written as part of the project "Advancing Dental Education in the 21st Century."

Clinical Correlations as a Tool in Basic Science Medical Education

Directory of Open Access Journals (Sweden)

Brenda J. Klement

2016-01-01

Full Text Available Clinical correlations are tools to assist students in associating basic science concepts with a medical application or disease. There are many forms of clinical correlations and many ways to use them in the classroom. Five types of clinical correlations that may be embedded within basic science courses have been identified and described. (1 Correlated examples consist of superficial clinical information or stories accompanying basic science concepts to make the information more interesting and relevant. (2 Interactive learning and demonstrations provide hands-on experiences or the demonstration of a clinical topic. (3 Specialized workshops have an application-based focus, are more specialized than typical laboratory sessions, and range in complexity from basic to advanced. (4 Small-group activities require groups of students, guided by faculty, to solve simple problems that relate basic science information to clinical topics. (5 Course-centered problem solving is a more advanced correlation activity than the others and focuses on recognition and treatment of clinical problems to promote clinical reasoning skills. Diverse teaching activities are used in basic science medical education, and those that include clinical relevance promote interest, communication, and collaboration, enhance knowledge retention, and help develop clinical reasoning skills.

Wake Conference 2017

International Nuclear Information System (INIS)

2017-01-01

The 52 papers in this volume constitute the proceedings of the 2017 Wake Conference, held in Visby on the island of Gotland, Sweden. The Wake Conference series began in Visby, where it was held in 2009 and 2011. In 2013 the conference took place in Copenhagen where it was combined with the International Conference on Offshore Wind Energy and Ocean Energy. In 2015 it went back to where it started, Visby, and this time it once again takes place at Uppsala University’s Gotland campus, May 30 th - June 1 st . Modern wind turbines are today clustered in large farms with a total production capacity reaching those of a nuclear power plant. When placed in a wind farm, the turbines will be fully or partially influenced by the wake of upstream turbines. This wake interaction results in a decreased power production, caused by the lower kinetic energy in the wind, and an increase in the turbulence intensity. Therefore, understanding the physical nature of vortices and their dynamics in the wake of a turbine is important for the optimal design of wind farms. The increased importance and interest in the field of wake and wind farm aerodynamics can be seen in the increased number of scientific articles on the subject. For example, on the Web of Science citation index, the number citations on the topic ‘wind turbine wakes’ increased from about 50 in 2006 to more than 3800 in 2016. This citation growth essentially shows that the growth in the global production of electrical energy has become a scientific problem to be solved by scientists and engineers. In order to make a substantial impact on one of the most significant challenges of our time, global climate change, the wind industry’s growth must continue. A part of making this growth possible will require research into the physics of wind turbine wakes and wind farms. This conference is aimed at scientists and PhD students working in the field of wake dynamics. The conference covers the following subject areas: Wake and

Basic Energy Sciences FY 2011 Research Summaries

Energy Technology Data Exchange (ETDEWEB)

None

2011-01-01

This report provides a collection of research abstracts for more than 1,300 research projects funded by the Office of Basic Energy Sciences (BES) in Fiscal Year 2011 at some 180 institutions across the U.S. This volume is organized along the three BES divisions: Materials Sciences and Engineering; Chemical Sciences, Geosciences, and Biosciences; and Scientific User Facilities.

Simulation of wind turbine wakes using the actuator line technique.

Science.gov (United States)

Sørensen, Jens N; Mikkelsen, Robert F; Henningson, Dan S; Ivanell, Stefan; Sarmast, Sasan; Andersen, Søren J

2015-02-28

The actuator line technique was introduced as a numerical tool to be employed in combination with large eddy simulations to enable the study of wakes and wake interaction in wind farms. The technique is today largely used for studying basic features of wakes as well as for making performance predictions of wind farms. In this paper, we give a short introduction to the wake problem and the actuator line methodology and present a study in which the technique is employed to determine the near-wake properties of wind turbines. The presented results include a comparison of experimental results of the wake characteristics of the flow around a three-bladed model wind turbine, the development of a simple analytical formula for determining the near-wake length behind a wind turbine and a detailed investigation of wake structures based on proper orthogonal decomposition analysis of numerically generated snapshots of the wake. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

The United Nations Basic Space Science Initiative

Science.gov (United States)

Haubold, Hans; Balogh, Werner

2014-05-01

The basic space science initiative was a long-term effort for the development of astronomy and space science through regional and international cooperation in this field on a worldwide basis, particularly in developing nations. Basic space science workshops were co-sponsored and co-organized by ESA, JAXA, and NASA. A series of workshops on basic space science was held from 1991 to 2004 (India 1991, Costa Rica and Colombia 1992, Nigeria 1993, Egypt 1994, Sri Lanka 1995, Germany 1996, Honduras 1997, Jordan 1999, France 2000, Mauritius 2001, Argentina 2002, and China 2004; http://neutrino.aquaphoenix.com/un-esa/) and addressed the status of astronomy in Asia and the Pacific, Latin America and the Caribbean, Africa, and Western Asia. Through the lead of the National Astronomical Observatory Japan, astronomical telescope facilities were inaugurated in seven developing nations and planetariums were established in twenty developing nations based on the donation of respective equipment by Japan.Pursuant to resolutions of the Committee on the Peaceful Uses of Outer Space of the United Nations (COPUOS) and its Scientific and Technical Subcommittee, since 2005, these workshops focused on the preparations for and the follow-ups to the International Heliophysical Year 2007 (UAE 2005, India 2006, Japan 2007, Bulgaria 2008, South Korea 2009; www.unoosa.org/oosa/SAP/bss/ihy2007/index.html). IHY's legacy is the current operation of 16 worldwide instrument arrays with more than 1000 instruments recording data on solar-terrestrial interaction from coronal mass ejections to variations of the total electron content in the ionosphere (http://iswisecretariat.org/). Instruments are provided to hosting institutions by entities of Armenia, Brazil, France, Israel, Japan, Switzerland, and the United States. Starting in 2010, the workshops focused on the International Space Weather Initiative (ISWI) as mandated in a three-year-work plan as part of the deliberations of COPUOS. Workshops on ISWI

Basic Energy Sciences FY 2012 Research Summaries

Energy Technology Data Exchange (ETDEWEB)

None

2012-01-01

This report provides a collection of research abstracts and highlights for more than 1,400 research projects funded by the Office of Basic Energy Sciences (BES) in Fiscal Year 2012 at some 180 institutions across the U.S. This volume is organized along the three BES Divisions: Materials Sciences and Engineering; Chemical Sciences, Geosciences, and Biosciences; and Scientific User Facilities.

Basic Energy Sciences FY 2014 Research Summaries

Energy Technology Data Exchange (ETDEWEB)

None

2014-01-01

This report provides a collection of research abstracts and highlights for more than 1,200 research projects funded by the Office of Basic Energy Sciences (BES) in Fiscal Year 2014 at some 200 institutions across the U.S. This volume is organized along the three BES Divisions: Materials Sciences and Engineering; Chemical Sciences, Geosciences, and Biosciences; and Scientific User Facilities.

Unsteady Double Wake Model for the Simulation of Stalled Airfoils

DEFF Research Database (Denmark)

Ramos García, Néstor; Cayron, Antoine; Sørensen, Jens Nørkær

2015-01-01

In the present work, the recent developed Unsteady Double Wake Model, USDWM, is used to simulate separated flows past a wind turbine airfoil at high angles of attack. The solver is basically an unsteady two-dimensional panel method which uses the unsteady double wake technique to model flow separ...

A simple stationary semi-analytical wake model

DEFF Research Database (Denmark)

Larsen, Gunner Chr.

We present an idealized simple, but fast, semi-analytical algorithm for computation of stationary wind farm wind fields with a possible potential within a multi-fidelity strategy for wind farm topology optimization. Basically, the model considers wakes as linear perturbations on the ambient non......-linear. With each of these approached, a parabolic system are described, which is initiated by first considering the most upwind located turbines and subsequently successively solved in the downstream direction. Algorithms for the resulting wind farm flow fields are proposed, and it is shown that in the limit......-uniform mean wind field, although the modelling of the individual stationary wake flow fields includes non-linear terms. The simulation of the individual wake contributions are based on an analytical solution of the thin shear layer approximation of the NS equations. The wake flow fields are assumed...

Speaking of food: connecting basic and applied plant science.

Science.gov (United States)

Gross, Briana L; Kellogg, Elizabeth A; Miller, Allison J

2014-10-01

The Food and Agriculture Organization (FAO) predicts that food production must rise 70% over the next 40 years to meet the demands of a growing population that is expected to reach nine billion by the year 2050. Many facets of basic plant science promoted by the Botanical Society of America are important for agriculture; however, more explicit connections are needed to bridge the gap between basic and applied plant research. This special issue, Speaking of Food: Connecting Basic and Applied Plant Science, was conceived to showcase productive overlaps of basic and applied research to address the challenges posed by feeding billions of people and to stimulate more research, fresh connections, and new paradigms. Contributions to this special issue thus illustrate some interactive areas of study in plant science-historical and modern plant-human interaction, crop and weed origins and evolution, and the effects of natural and artificial selection on crops and their wild relatives. These papers provide examples of how research integrating the basic and applied aspects of plant science benefits the pursuit of knowledge and the translation of that knowledge into actions toward sustainable production of crops and conservation of diversity in a changing climate. © 2014 Botanical Society of America, Inc.

An Analysison Provincial Medical Science Basic Research Competitiveness Based on the National Natural Science Foundation of China

Directory of Open Access Journals (Sweden)

Xing Xia

2017-06-01

Full Text Available [Purpose/significance] The National Natural Science Foundation of China (NSFC is one of the most important channels to support basic research in China. Competition for funding by the NSFC has been a very important indicator to measure the basic research level of various province and scientific research institutions. [Method/process] By combing and analyzing the status quo of NSFC in medical science, it is helpful to narrow the provincial gap and improve the basic research of medical science in China. Based on the project information of NSFC and previous scholars’ research, the paper update the index of basic research competitiveness, and analyzes project number and project funding of medical science during 2006-2016. At the same time, the competitiveness of medical science basic research and its changing trend in 31 provinces of China are analyzed. [Result/conclusion] The result shows that, in recent years, China’s basic scientific research has greatly improved, but there is a large gap between the provinces.

75 FR 65363 - Basic Behavioral and Social Science Opportunity Network (OppNet)

Science.gov (United States)

2010-10-22

... public meeting to promote and publicize the Basic Behavioral and Social Science Opportunity Network (Opp... . Background: The Basic Behavioral and Social Science Opportunity Network (OppNet) is a trans-NIH initiative to expand the agency's funding of basic behavioral and social sciences research (b-BSSR). OppNet prioritizes...

Empirical modeling of single-wake advection and expansion using full-scale pulsed lidar-based measurements

DEFF Research Database (Denmark)

Machefaux, Ewan; Larsen, Gunner Chr.; Troldborg, Niels

2015-01-01

In the present paper, single-wake dynamics have been studied both experimentally and numerically. The use of pulsed lidar measurements allows for validation of basic dynamic wake meandering modeling assumptions. Wake center tracking is used to estimate the wake advection velocity experimentally...... fairly well in the far wake but lacks accuracy in the outer region of the near wake. An empirical relationship, relating maximum wake induction and wake advection velocity, is derived and linked to the characteristics of a spherical vortex structure. Furthermore, a new empirical model for single...

Integration of Basic and Clinical Science in the Psychiatry Clerkship.

Science.gov (United States)

Wilkins, Kirsten M; Moore, David; Rohrbaugh, Robert M; Briscoe, Gregory W

2017-06-01

Integration of basic and clinical science is a key component of medical education reform, yet best practices have not been identified. The authors compared two methods of basic and clinical science integration in the psychiatry clerkship. Two interventions aimed at integrating basic and clinical science were implemented and compared in a dementia conference: flipped curriculum and coteaching by clinician and physician-scientist. The authors surveyed students following each intervention. Likert-scale responses were compared. Participants in both groups responded favorably to the integration format and would recommend integration be implemented elsewhere in the curriculum. Survey response rates differed significantly between the groups and student engagement with the flipped curriculum video was limited. Flipped curriculum and co-teaching by clinician and physician-scientist are two methods of integrating basic and clinical science in the psychiatry clerkship. Student learning preferences may influence engagement with a particular teaching format.

Fast-Acting Sublingual Zolpidem for Middle-of-the-Night Wakefulness

Directory of Open Access Journals (Sweden)

Joseph V. Pergolizzi

2014-01-01

Full Text Available Sleep disorders (somnipathies are conditions characterized by disruptions of sleep quality or of sleep pattern. They can involve difficulty falling asleep (prolonged sleep onset latency, difficulty staying asleep (disturbance of sleep maintenance, sleep of poor quality (unrefreshing, or combinations of these and can lead to poor health and quality of life problems. A subtype of sleep-maintenance insomnia is middle-of-the-night wakefulness, a relatively common occurrence. Zolpidem, a nonbenzodiazepine benzodiazepine receptor agonist, allosterically modulates an ion channel and increases the influx of Cl−, thereby dampening the effect of excitatory (sleep disrupting input. Recently, product label changes to some zolpidem containing products have been implemented by the FDA in order to reduce the risk associated with their morning after residual side effects. A new formulation of zolpidem tartrate (Intermezzo sublingual tablet, an approved product indicated exclusively for the treatment of middle-of-the-night wakefulness and difficulty returning to sleep, did not have its label changed. We present a short summary of its basic science and clinical attributes in light of the recent regulatory changes for zolpidem products.

Solar heating. Vol. 1. Basic knowledge of thermal science

Energy Technology Data Exchange (ETDEWEB)

Jauffret, C.

1982-01-01

This document deals with general basic knowledge of thermal sciences: basics of thermodynamics, heat transfer, studies of thermal exchanges in the building industry including ventilation and the effects of the wind, basics and techniques of central heating and refrigeration (technologies, calculations, thermodynamic cycles and refrigerating machines).

Wake meandering under non-neutral atmospheric stability conditions – theory and facts

DEFF Research Database (Denmark)

Larsen, Gunner Chr.; Machefaux, Ewan; Chougule, Abhijit S.

2015-01-01

This paper deals with modelling of wake dynamics under influence of atmospheric stability conditions different from neutral. In particular, it is investigated how the basic split in turbulent scales, on which the Dynamic Wake Meandering model is based, can be utilized to include atmospheric...... stability effects in this model. This is done partly by analyzing a large number of turbulence spectra obtained from sonic measurements, partly by analyzing dedicated full-scale LiDAR measurements from which wake dynamics can be directly resolved. The theory behind generalizing the Dynamic Wake Meandering...

FWP executive summaries: basic energy sciences materials sciences and engineering program (SNL/NM).

Energy Technology Data Exchange (ETDEWEB)

Samara, George A.; Simmons, Jerry A.

2006-07-01

This report presents an Executive Summary of the various elements of the Materials Sciences and Engineering Program which is funded by the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy at Sandia National Laboratories, New Mexico. A general programmatic overview is also presented.

Effects of Aircraft Wake Dynamics on Measured and Simulated NO(x) and HO(x) Wake Chemistry. Appendix B

Science.gov (United States)

Lewellen, D. C.; Lewellen, W. S.

2001-01-01

High-resolution numerical large-eddy simulations of the near wake of a B757 including simplified NOx and HOx chemistry were performed to explore the effects of dynamics on chemistry in wakes of ages from a few seconds to several minutes. Dilution plays an important basic role in the NOx-O3 chemistry in the wake, while a more interesting interaction between the chemistry and dynamics occurs for the HOx species. These simulation results are compared with published measurements of OH and HO2 within a B757 wake under cruise conditions in the upper troposphere taken during the Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS) mission in May 1996. The simulation provides a much finer grained representation of the chemistry and dynamics of the early wake than is possible from the 1 s data samples taken in situ. The comparison suggests that the previously reported discrepancy of up to a factor of 20 - 50 between the SUCCESS measurements of the [HO2]/[OH] ratio and that predicted by simplified theoretical computations is due to the combined effects of large mixing rates around the wake plume edges and averaging over volumes containing large species fluctuations. The results demonstrate the feasibility of using three-dimensional unsteady large-eddy simulations with coupled chemistry to study such phenomena.

Nigerian Journal of Basic and Applied Sciences: Editorial Policies

African Journals Online (AJOL)

The Nigerian Journal of Basic and Applied Sciences is a biannual journal ... S.A. Isezuo, College of Health Sciences, UsmanuDanfodiyo University, Sokoto, ... of Mathematics, Statistics Unit, UsmanuDanfodiyo University, Sokoto, Nigeria. 7.

Basic concepts in social sciences I

NARCIS (Netherlands)

Hoede, C.

2000-01-01

In this paper the results are given of an investigation into concepts from Economics, Organization Theory, Political Science, Psychology and Sociology. The goal of this investigation was to find out whether there is a set of concepts that may be considered to be basic to all these five social

A critical narrative review of transfer of basic science knowledge in health professions education.

Science.gov (United States)

Castillo, Jean-Marie; Park, Yoon Soo; Harris, Ilene; Cheung, Jeffrey J H; Sood, Lonika; Clark, Maureen D; Kulasegaram, Kulamakan; Brydges, Ryan; Norman, Geoffrey; Woods, Nicole

2018-02-08

'Transfer' is the application of a previously learned concept to solve a new problem in another context. Transfer is essential for basic science education because, to be valuable, basic science knowledge must be transferred to clinical problem solving. Therefore, better understanding of interventions that enhance the transfer of basic science knowledge to clinical reasoning is essential. This review systematically identifies interventions described in the health professions education (HPE) literature that document the transfer of basic science knowledge to clinical reasoning, and considers teaching and assessment strategies. A systematic search of the literature was conducted. Articles related to basic science teaching at the undergraduate level in HPE were analysed using a 'transfer out'/'transfer in' conceptual framework. 'Transfer out' refers to the application of knowledge developed in one learning situation to the solving of a new problem. 'Transfer in' refers to the use of previously acquired knowledge to learn from new problems or learning situations. Of 9803 articles initially identified, 627 studies were retrieved for full text evaluation; 15 were included in the literature review. A total of 93% explored 'transfer out' to clinical reasoning and 7% (one article) explored 'transfer in'. Measures of 'transfer out' fostered by basic science knowledge included diagnostic accuracy over time and in new clinical cases. Basic science knowledge supported learning - 'transfer in' - of new related content and ultimately the 'transfer out' to diagnostic reasoning. Successful teaching strategies included the making of connections between basic and clinical sciences, the use of commonsense analogies, and the study of multiple clinical problems in multiple contexts. Performance on recall tests did not reflect the transfer of basic science knowledge to clinical reasoning. Transfer of basic science knowledge to clinical reasoning is an essential component of HPE that

Basic energy sciences at the Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Postma, H.

1985-01-01

The testimony expresses concerns about two areas of the FY-86 budget and goes on to discuss basic energy science programs at ORNL, scientific results, support of technologies, user facilities, recent significant discoveries, support of major facilities and ORNL trends in basic research

Storytelling in Earth sciences: The eight basic plots

Science.gov (United States)

Phillips, Jonathan

2012-11-01

Reporting results and promoting ideas in science in general, and Earth science in particular, is treated here as storytelling. Just as in literature and drama, storytelling in Earth science is characterized by a small number of basic plots. Though the list is not exhaustive, and acknowledging that multiple or hybrid plots and subplots are possible in a single piece, eight standard plots are identified, and examples provided: cause-and-effect, genesis, emergence, destruction, metamorphosis, convergence, divergence, and oscillation. The plots of Earth science stories are not those of literary traditions, nor those of persuasion or moral philosophy, and deserve separate consideration. Earth science plots do not conform those of storytelling more generally, implying that Earth scientists may have fundamentally different motivations than other storytellers, and that the basic plots of Earth Science derive from the characteristics and behaviors of Earth systems. In some cases preference or affinity to different plots results in fundamentally different interpretations and conclusions of the same evidence. In other situations exploration of additional plots could help resolve scientific controversies. Thus explicit acknowledgement of plots can yield direct scientific benefits. Consideration of plots and storytelling devices may also assist in the interpretation of published work, and can help scientists improve their own storytelling.

Information-seeking behavior of basic science researchers: implications for library services.

Science.gov (United States)

Haines, Laura L; Light, Jeanene; O'Malley, Donna; Delwiche, Frances A

2010-01-01

This study examined the information-seeking behaviors of basic science researchers to inform the development of customized library services. A qualitative study using semi-structured interviews was conducted on a sample of basic science researchers employed at a university medical school. The basic science researchers used a variety of information resources ranging from popular Internet search engines to highly technical databases. They generally relied on basic keyword searching, using the simplest interface of a database or search engine. They were highly collegial, interacting primarily with coworkers in their laboratories and colleagues employed at other institutions. They made little use of traditional library services and instead performed many traditional library functions internally. Although the basic science researchers expressed a positive attitude toward the library, they did not view its resources or services as integral to their work. To maximize their use by researchers, library resources must be accessible via departmental websites. Use of library services may be increased by cultivating relationships with key departmental administrative personnel. Despite their self-sufficiency, subjects expressed a desire for centralized information about ongoing research on campus and shared resources, suggesting a role for the library in creating and managing an institutional repository.

Making evolutionary biology a basic science for medicine

Science.gov (United States)

Nesse, Randolph M.; Bergstrom, Carl T.; Ellison, Peter T.; Flier, Jeffrey S.; Gluckman, Peter; Govindaraju, Diddahally R.; Niethammer, Dietrich; Omenn, Gilbert S.; Perlman, Robert L.; Schwartz, Mark D.; Thomas, Mark G.; Stearns, Stephen C.; Valle, David

2010-01-01

New applications of evolutionary biology in medicine are being discovered at an accelerating rate, but few physicians have sufficient educational background to use them fully. This article summarizes suggestions from several groups that have considered how evolutionary biology can be useful in medicine, what physicians should learn about it, and when and how they should learn it. Our general conclusion is that evolutionary biology is a crucial basic science for medicine. In addition to looking at established evolutionary methods and topics, such as population genetics and pathogen evolution, we highlight questions about why natural selection leaves bodies vulnerable to disease. Knowledge about evolution provides physicians with an integrative framework that links otherwise disparate bits of knowledge. It replaces the prevalent view of bodies as machines with a biological view of bodies shaped by evolutionary processes. Like other basic sciences, evolutionary biology needs to be taught both before and during medical school. Most introductory biology courses are insufficient to establish competency in evolutionary biology. Premedical students need evolution courses, possibly ones that emphasize medically relevant aspects. In medical school, evolutionary biology should be taught as one of the basic medical sciences. This will require a course that reviews basic principles and specific medical applications, followed by an integrated presentation of evolutionary aspects that apply to each disease and organ system. Evolutionary biology is not just another topic vying for inclusion in the curriculum; it is an essential foundation for a biological understanding of health and disease. PMID:19918069

Integration of Basic and Clinical Sciences: Faculty Perspectives at a U.S. Dental School.

Science.gov (United States)

van der Hoeven, Dharini; van der Hoeven, Ransome; Zhu, Liang; Busaidy, Kamal; Quock, Ryan L

2018-04-01

Although dental education has traditionally been organized into basic sciences education (first and second years) and clinical education (third and fourth years), there has been growing interest in ways to better integrate the two to more effectively educate students and prepare them for practice. Since 2012, The University of Texas School of Dentistry at Houston (UTSD) has made it a priority to improve integration of basic and clinical sciences, with a focus to this point on integrating the basic sciences. The aim of this study was to determine the perspectives of basic and clinical science faculty members regarding basic and clinical sciences integration and the degree of integration currently occurring. In October 2016, all 227 faculty members (15 basic scientists and 212 clinicians) were invited to participate in an online survey. Of the 212 clinicians, 84 completed the clinician educator survey (response rate 40%). All 15 basic scientists completed the basic science educator survey (response rate 100%). The majority of basic and clinical respondents affirmed the value of integration (93.3%, 97.6%, respectively) and reported regular integration in their teaching (80%, 86.9%). There were no significant differences between basic scientists and clinicians on perceived importance (p=0.457) and comfort with integration (p=0.240), but the basic scientists were more likely to integrate (p=0.039) and collaborate (p=0.021) than the clinicians. There were no significant differences between generalist and specialist clinicians on importance (p=0.474) and degree (p=0.972) of integration in teaching and intent to collaborate (p=0.864), but the specialists reported feeling more comfortable presenting basic science information (p=0.033). Protected faculty time for collaborative efforts and a repository of integrated basic science and clinical examples for use in teaching and faculty development were recommended to improve integration. Although questions might be raised about

Progress in the Utilization of High-Fidelity Simulation in Basic Science Education

Science.gov (United States)

Helyer, Richard; Dickens, Peter

2016-01-01

High-fidelity patient simulators are mainly used to teach clinical skills and remain underutilized in teaching basic sciences. This article summarizes our current views on the use of simulation in basic science education and identifies pitfalls and opportunities for progress.

Preparing medical students for future learning using basic science instruction.

Science.gov (United States)

Mylopoulos, Maria; Woods, Nicole

2014-07-01

The construct of 'preparation for future learning' (PFL) is understood as the ability to learn new information from available resources, relate new learning to past experiences and demonstrate innovation and flexibility in problem solving. Preparation for future learning has been proposed as a key competence of adaptive expertise. There is a need for educators to ensure that opportunities are provided for students to develop PFL ability and that assessments accurately measure the development of this form of competence. The objective of this research was to compare the relative impacts of basic science instruction and clinically focused instruction on performance on a PFL assessment (PFLA). This study employed a 'double transfer' design. Fifty-one pre-clerkship students were randomly assigned to either basic science instruction or clinically focused instruction to learn four categories of disease. After completing an initial assessment on the learned material, all participants received clinically focused instruction for four novel diseases and completed a PFLA. The data from the initial assessment and the PFLA were submitted to independent-sample t-tests. Mean ± standard deviation [SD] scores on the diagnostic cases in the initial assessment were similar for participants in the basic science (0.65 ± 0.11) and clinical learning (0.62 ± 0.11) conditions. The difference was not significant (t[42] = 0.90, p = 0.37, d = 0.27). Analysis of the diagnostic cases on the PFLA revealed significantly higher mean ± SD scores for participants in the basic science learning condition (0.72 ± 0.14) compared with those in the clinical learning condition (0.63 ± 0.15) (t[42] = 2.02, p = 0.05, d = 0.62). Our results show that the inclusion of basic science instruction enhanced the learning of novel related content. We discuss this finding within the broader context of research on basic science instruction, development of adaptive expertise and assessment

Basic science research in urology training.

Science.gov (United States)

Eberli, D; Atala, A

2009-04-01

The role of basic science exposure during urology training is a timely topic that is relevant to urologic health and to the training of new physician scientists. Today, researchers are needed for the advancement of this specialty, and involvement in basic research will foster understanding of basic scientific concepts and the development of critical thinking skills, which will, in turn, improve clinical performance. If research education is not included in urology training, future urologists may not be as likely to contribute to scientific discoveries.Currently, only a minority of urologists in training are currently exposed to significant research experience. In addition, the number of physician-scientists in urology has been decreasing over the last two decades, as fewer physicians are willing to undertake a career in academics and perform basic research. However, to ensure that the field of urology is driving forward and bringing novel techniques to patients, it is clear that more research-trained urologists are needed. In this article we will analyse the current status of basic research in urology training and discuss the importance of and obstacles to successful addition of research into the medical training curricula. Further, we will highlight different opportunities for trainees to obtain significant research exposure in urology.

191 Students' Self-Concept and Their Achievement in Basic Science ...

African Journals Online (AJOL)

User

2011-07-21

Jul 21, 2011 ... Achievement Test in Basic showed Science (SATBS) were employed as .... Higher Studies; Teacher-Students opinion and found out that students .... Factors and Pupils Leaning Outcome in Bended Primary Science Project,.

Waking-up to Science!

Science.gov (United States)

2007-03-01

The Science on Stage festival as an alarm clock for science teaching How is Europe to tackle its shortage of scientists? The EIROforum Science on Stage festival aims to give European teachers some of the answers they need to take up this urgent challenge. This unique event, showcasing the very best of today's science education, will feature science demonstrations, a science teaching fair with some 66 stands, and a Round Table discussion with the participation of the European Commissioner for Science and Research, Janez Potočnik. ESO PR Photo 14/07 ESO PR Photo 14/07 Science on Stage will have the city of Grenoble (France) buzzing from 2 to 6 April 2007. A rugby team and a hockey team will take on the power of the vacuum, a cook will demonstrate how science can inspire new culinary ideas, visitors will discover the real colour of the sun, an inflatable model of Borromini's gallery will help to explain the science of optical illusions, and Merlin himself will reveal all about how to make a cake float. These are just some of the exciting things that will be happening at the EIROforum Science on Stage festival. By showing how fascinating and entertaining science can be, the event aims to attract young people to science and ultimately help to reduce the shortage of scientists in Europe. With support from the European Commission, this international festival will bring together some 500 science educators from 27 European countries. The highlight of the festival will be a Round Table discussion on 'Science Education in the Age of the Knowledge Society - Strengthening Science Education in Europe', which will take place on 5 April 2007 with the participation of the European Commissioner for Science and Research, Janez Potočnik. The panellists - all high-ranking decision-makers - will include the Danish Minister for Education, Bertel Haarder, the MEP Vittorio Prodi, and the Chair of the UK's Engineering and Physical Sciences Research Council, Julia Higgins. "Curiosity is in

Basic and Applied Science Research at the Los Alamos Neutron Science Center

International Nuclear Information System (INIS)

Lisowski, Paul W.

2005-01-01

The Los Alamos Neutron Science Center, or LANSCE, is an accelerator-based national user facility for research in basic and applied science using four experimental areas. LANSCE has two areas that provide neutrons generated by the 800-MeV proton beam striking tungsten target systems. A third area uses the proton beam for radiography. The fourth area uses 100 MeV protons to produce medical radioisotopes. This paper describes the four LANSCE experimental areas, gives nuclear science highlights of the past operating period, and discusses plans for the future

Experimental studies of plasma wake-field acceleration and focusing

International Nuclear Information System (INIS)

Rosenzweig, J.B.; Cole, B.; Ho, C.; Argonne National Lab., IL

1989-01-01

More than four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These large amplitude plasma wake-fields are of interest in the laboratory, both for the wealth of basic nonlinear plasma wave phenomena which can be studied, as well as for the applications of acceleration of focusing of electrons and positrons in future linear colliders. Plasma wake-field waves are also of importance in nature, due to their possible role in direct cosmic ray acceleration. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory, in which many interesting beam and plasma phenomena have been observed. Emphasis is given to discussion of the nonlinear aspects of the PWFA beam-plasma interaction. 29 refs., 13 figs

Editorial Commentary: A Model for Shoulder Rotator Cuff Repair and for Basic Science Investigations.

Science.gov (United States)

Brand, Jefferson C

2018-04-01

"Breaking the fourth wall" is a theater convention where the narrator or character speaks directly to the audience. As an Assistant Editor-in-Chief, as I comment on a recent basic science study investigating rotator cuff repair, I break the fourth wall and articulate areas of basic science research excellence that align with the vision that we hold for our journal. Inclusion of a powerful video strengthens the submission. We prefer to publish clinical videos in our companion journal, Arthroscopy Techniques, and encourage basic science video submissions to Arthroscopy. Basic science research requires step-by-tedious-step analogous to climbing a mountain. Establishment of a murine rotator cuff repair model was rigorous and research intensive, biomechanically, radiographically, histologically, and genetically documented, a huge step toward the bone-to-tendon healing research summit. This research results in a model for both rotator cuff repair and the pinnacle of quality, basic science research. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Fundamentals of neurogastroenterology: basic science.

Science.gov (United States)

Grundy, David; Al-Chaer, Elie D; Aziz, Qasim; Collins, Stephen M; Ke, Meiyun; Taché, Yvette; Wood, Jackie D

2006-04-01

The focus of neurogastroenterology in Rome II was the enteric nervous system (ENS). To avoid duplication with Rome II, only advances in ENS neurobiology after Rome II are reviewed together with stronger emphasis on interactions of the brain, spinal cord, and the gut in terms of relevance for abdominal pain and disordered gastrointestinal function. A committee with expertise in selective aspects of neurogastroenterology was invited to evaluate the literature and provide a consensus overview of the Fundamentals of Neurogastroenterology textbook as they relate to functional gastrointestinal disorders (FGIDs). This review is an abbreviated version of a fuller account that appears in the forthcoming book, Rome III. This report reviews current basic science understanding of visceral sensation and its modulation by inflammation and stress and advances in the neurophysiology of the ENS. Many of the concepts are derived from animal studies in which the physiologic mechanisms underlying visceral sensitivity and neural control of motility, secretion, and blood flow are examined. Impact of inflammation and stress in experimental models relative to FGIDs is reviewed as is human brain imaging, which provides a means for translating basic science to understanding FGID symptoms. Investigative evidence and emerging concepts implicate dysfunction in the nervous system as a significant factor underlying patient symptoms in FGIDs. Continued focus on neurogastroenterologic factors that underlie the development of symptoms will lead to mechanistic understanding that is expected to directly benefit the large contingent of patients and care-givers who deal with FGIDs.

A brief simulation intervention increasing basic science and clinical knowledge

Directory of Open Access Journals (Sweden)

Maria L. Sheakley

2016-04-01

Full Text Available Background: The United States Medical Licensing Examination (USMLE is increasing clinical content on the Step 1 exam; thus, inclusion of clinical applications within the basic science curriculum is crucial. Including simulation activities during basic science years bridges the knowledge gap between basic science content and clinical application. Purpose: To evaluate the effects of a one-off, 1-hour cardiovascular simulation intervention on a summative assessment after adjusting for relevant demographic and academic predictors. Methods: This study was a non-randomized study using historical controls to evaluate curricular change. The control group received lecture (n l=515 and the intervention group received lecture plus a simulation exercise (nl+s=1,066. Assessment included summative exam questions (n=4 that were scored as pass/fail (≥75%. USMLE-style assessment questions were identical for both cohorts. Descriptive statistics for variables are presented and odds of passage calculated using logistic regression. Results: Undergraduate grade point ratio, MCAT-BS, MCAT-PS, age, attendance at an academic review program, and gender were significant predictors of summative exam passage. Students receiving the intervention were significantly more likely to pass the summative exam than students receiving lecture only (P=0.0003. Discussion: Simulation plus lecture increases short-term understanding as tested by a written exam. A longitudinal study is needed to assess the effect of a brief simulation intervention on long-term retention of clinical concepts in a basic science curriculum.

Basic Pharmaceutical Sciences Examination as a Predictor of Student Performance during Clinical Training.

Science.gov (United States)

Fassett, William E.; Campbell, William H.

1984-01-01

A comparison of Basic Pharmaceutical Sciences Examination (BPSE) results with student performance evaluations in core clerkships, institutional and community externships, didactic and clinical courses, and related basic science coursework revealed the BPSE does not predict student performance during clinical instruction. (MSE)

Prediction of multi-wake problems using an improved Jensen wake model

DEFF Research Database (Denmark)

Tian, Linlin; Zhu, Wei Jun; Shen, Wen Zhong

2017-01-01

The improved analytical wake model named as 2D_k Jensen model (which was proposed to overcome some shortcomes in the classical Jensen wake model) is applied and validated in this work for wind turbine multi-wake predictions. Different from the original Jensen model, this newly developed 2D_k Jensen...... model uses a cosine shape instead of the top-hat shape for the velocity deficit in the wake, and the wake decay rate as a variable that is related to the ambient turbulence as well as the rotor generated turbulence. Coupled with four different multi-wake combination models, the 2D_k Jensen model...... is assessed through (1) simulating two wakes interaction under full wake and partial wake conditions and (2) predicting the power production in the Horns Rev wind farm for different wake sectors around two different wind directions. Through comparisons with field measurements, results from Large Eddy...

Armodafinil in the treatment of sleep/wake disorders

Directory of Open Access Journals (Sweden)

Jonathan RL Schwartz

2010-07-01

Full Text Available Jonathan RL Schwartz1,Thomas Roth2, Chris Drake21INTEGRIS Sleep Disorders Center and University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; 2Sleep Disorders and Research Center, Henry Ford Hospital, Detroit, MI, USAAbstract: Excessive sleepiness (ES is a major but underestimated public health concern associated with significant impairments in alertness/wakefulness and significant morbidity. The term ES has been used in the sleep medicine literature for years, but due to its nonspecific symptoms (ie tiredness or fatigue, it frequently goes unrecognized or is misdiagnosed in primary care. In some cases ES arises due to poor sleep habits or self-imposed sleep deprivation; however, ES is also a key component of a number of sleep/wake disorders and multiple medical and psychiatric disorders. Identification and treatment of ES is critical to improve the quality of life and well-being of patients and for the safety of the wider community. The inability of patients to recognize the nature, extent, and symptomatic profile of sleep/wake disorders requires vigilance on the part of healthcare professionals. Interventions to address ES and its associated impairments, treatment of the underlying sleep/wake disorder, and follow-up are a priority given the potential for serious consequences if left untreated. Wakefulness-promoting agents are available that treat ES associated with sleep/wake disorders. This review examines current approaches for managing this debilitating and potentially life-threatening condition, focusing on the place of armodafinil as a wakefulness-promoting agent.Keywords: excessive sleepiness, wakefulness, armodafinil, obstructive sleep apnea, narcolepsy, shift-work disorder

The United Nations Basic Space Science Initiative

Science.gov (United States)

Haubold, H. J.

2006-08-01

Pursuant to recommendations of the United Nations Conference on the Exploration and Peaceful Uses of Outer Space (UNISPACE III) and deliberations of the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS), annual UN/ European Space Agency workshops on basic space science have been held around the world since 1991. These workshops contribute to the development of astrophysics and space science, particularly in developing nations. Following a process of prioritization, the workshops identified the following elements as particularly important for international cooperation in the field: (i) operation of astronomical telescope facilities implementing TRIPOD, (ii) virtual observatories, (iii) astrophysical data systems, (iv) concurrent design capabilities for the development of international space missions, and (v) theoretical astrophysics such as applications of nonextensive statistical mechanics. Beginning in 2005, the workshops focus on preparations for the International Heliophysical Year 2007 (IHY2007). The workshops continue to facilitate the establishment of astronomical telescope facilities as pursued by Japan and the development of low-cost, ground-based, world-wide instrument arrays as lead by the IHY secretariat. Wamsteker, W., Albrecht, R. and Haubold, H.J.: Developing Basic Space Science World-Wide: A Decade of UN/ESA Workshops. Kluwer Academic Publishers, Dordrecht 2004. http://ihy2007.org http://www.unoosa.org/oosa/en/SAP/bss/ihy2007/index.html http://www.cbpf.br/GrupPesq/StatisticalPhys/biblio.htm

Teaching Basic Probability in Undergraduate Statistics or Management Science Courses

Science.gov (United States)

Naidu, Jaideep T.; Sanford, John F.

2017-01-01

Standard textbooks in core Statistics and Management Science classes present various examples to introduce basic probability concepts to undergraduate business students. These include tossing of a coin, throwing a die, and examples of that nature. While these are good examples to introduce basic probability, we use improvised versions of Russian…

Wakes behind surface-mounted obstacles: Impact of aspect ratio, incident angle, and surface roughness

Science.gov (United States)

Tobin, Nicolas; Chamorro, Leonardo P.

2018-03-01

The so-called wake-moment coefficient C˜h and lateral wake deflection of three-dimensional windbreaks are explored in the near and far wake. Wind-tunnel experiments were performed to study the functional dependence of C˜h with windbreak aspect ratio, incidence angle, and the ratio of the windbreak height and surface roughness (h /z0 ). Supported with the data, we also propose basic models for the wake deflection of the windbreak in the near and far fields. The near-wake model is based on momentum conservation considering the drag on the windbreak, whereas the far-wake counterpart is based on existing models for wakes behind surface-mounted obstacles. Results show that C˜h does not change with windbreak aspect ratios of 10 or greater; however, it may be lower for an aspect ratio of 5. C˜h is found to change roughly with the cosine of the incidence angle, and to depend strongly on h /z0 . The data broadly support the proposed wake-deflection models, though better predictions could be made with improved knowledge of the windbreak drag coefficient.

Welding As Science: Applying Basic Engineering Principles to the Discipline

Science.gov (United States)

Nunes, A. C., Jr.

2010-01-01

This Technical Memorandum provides sample problems illustrating ways in which basic engineering science has been applied to the discipline of welding. Perhaps inferences may be drawn regarding optimal approaches to particular welding problems, as well as for the optimal education for welding engineers. Perhaps also some readers may be attracted to the science(s) of welding and may make worthwhile contributions to the discipline.

Basic science and energy research sector profile: Background for the National Energy Strategy

Energy Technology Data Exchange (ETDEWEB)

March, F.; Ashton, W.B.; Kinzey, B.R.; McDonald, S.C.; Lee, V.E.

1990-11-01

This Profile report provides a general perspective on the role of basic science in the spectrum of research and development in the United States, and basic research's contributions to the goals of the National Energy Strategy (NES). It includes selected facts, figures, and analysis of strategic issues affecting the future of science in the United States. It is provided as background for people from government, the private sector, academia, and the public, who will be reviewing the NES in the coming months; and it is intended to serve as the basis for discussion of basic science issues within the context of the developing NES.

Multiple Turbine Wakes

DEFF Research Database (Denmark)

Machefaux, Ewan; Mann, Jakob

and to obtain an estimate of the wake expansion in a fixed frame of reference. A comparison of selected datasets from the campaign showed good far wake agreements of mean wake expansion with Actuator Line CFD computations and simpler engineering models. An empirical relationship, relating maximum wake induction...... for modeling the resulting double wake deficit is only relevant at high turbine thrust coefficients. For high wind speed and low thrust coefficient, linear summation should be primarily used. The first iteration of a new engineering model capable of modeling the overlapped wake deficit is formulated and its...... measurement and simulation is seen in both the fixed and the meandering frame of reference. A benchmark of several wake accumulation models is performed as a basis for the subsequent development of an engineering model for wake interaction.Finally, the validated numerical CFD model is used as part...

Science as Knowledge, Practice, and Map Making: The Challenge of Defining Metrics for Evaluating and Improving DOE-Funded Basic Experimental Science

Energy Technology Data Exchange (ETDEWEB)

Bodnarczuk, M.

1993-03-01

Industrial R&D laboratories have been surprisingly successful in developing performance objectives and metrics that convincingly show that planning, management, and improvement techniques can be value-added to the actual output of R&D organizations. In this paper, I will discuss the more difficult case of developing analogous constructs for DOE-funded non-nuclear, non-weapons basic research, or as I will refer to it - basic experimental science. Unlike most industrial R&D or the bulk of applied science performed at the National Renewable Energy Laboratory (NREL), the purpose of basic experimental science is producing new knowledge (usually published in professional journals) that has no immediate application to the first link (the R) of a planned R&D chain. Consequently, performance objectives and metrics are far more difficult to define. My claim is that if one can successfully define metrics for evaluating and improving DOE-funded basic experimental science (which is the most difficult case), then defining such constructs for DOE-funded applied science should be much less problematic. With the publication of the DOE Standard - Implementation Guide for Quality Assurance Programs for Basic and Applied Research (DOE-ER-STD-6001-92) and the development of a conceptual framework for integrating all the DOE orders, we need to move aggressively toward the threefold next phase: (1) focusing the management elements found in DOE-ER-STD-6001-92 on the main output of national laboratories - the experimental science itself; (2) developing clearer definitions of basic experimental science as practice not just knowledge; and (3) understanding the relationship between the metrics that scientists use for evaluating the performance of DOE-funded basic experimental science, the management elements of DOE-ER-STD-6001-92, and the notion of continuous improvement.

Basic science research and education: a priority for training and capacity building in developing countries.

Science.gov (United States)

Deckelbaum, Richard J; Ntambi, James M; Wolgemuth, Debra J

2011-09-01

This article provides evidence that basic science research and education should be key priorities for global health training, capacity building, and practice. Currently, there are tremendous gaps between strong science education and research in developed countries (the North) as compared to developing countries (the South). In addition, science research and education appear as low priorities in many developing countries. The need to stress basic science research beyond the typical investment of infectious disease basic service and research laboratories in developing areas is significant in terms of the benefits, not only to education, but also for economic strengthening and development of human resources. There are some indications that appreciation of basic science research education and training is increasing, but this still needs to be applied more rigorously and strengthened systematically in developing countries. Copyright © 2011 Elsevier Inc. All rights reserved.

Numerical investigations of wake interactions of two wind turbines in tandem

Science.gov (United States)

Qian, Yaoru; Wang, Tongguang

2018-05-01

Aerodynamic performance and wake interactions between two wind turbine models under different layouts are investigated numerically using large eddy simulation in conjunction with actuator line method based on the “Blind Test” series wind tunnel experiments from Norwegian University of Science and Technology. Numerical results of the power and thrust coefficients of the two rotors and wake characteristics are in good agreement with the experimental measurements. Extended investigations emphasizing the influence of different layout arrangements on the downstream rotor performance and wake development are conducted. Results show that layout arrangements have great influence on the power and thrust prediction of the downstream turbine.

Emotional Value Judgment and Achievement in Basic Science ...

African Journals Online (AJOL)

The study sought to examine emotional value judgment on student achievement in Basic Science. The study was carried out in Ijebu-North Local Government Area of Ogun State. Data were collected through valid questionnaire sent to five secondary schools within the local Government. One Hundred Junior Secondary II ...

Physiotherapy Students’ Attitudes to Basic Medical Sciences Courses

Directory of Open Access Journals (Sweden)

Vasaghi Gharamaleki B

2015-04-01

Full Text Available  Aims: Students’ attitude to the basic sciences courses has a considerable impact in their clinical practice. The aim of this study was to investigate the attitudes of undergraduate and graduate students to the Physiotherapy rather than basic science. Instrument & Methods: This descriptive cross-sectional study was done on 151 undergraduate and graduate schools of Physiotherapy and Rehabilitation, Tehran and Iran University of Medical Sciences students using easy access sampling in October and November of 2012. To evaluate the attitude and the importance and effectiveness subscales the West questionnaire was used. Data were analyzed using SPSS 17 software using One-way ANOVA, independent T, and logistic regression tests. Findings: There was a significant difference between the sexes in response to items 1, 4, 7 and 8. The attitudes mean and the importance and effectiveness subscales were greater in women in the bachelor fifth and seventh semesters. The attitude and the importance of women were significantly more positive than men in Master degree students of the first semester, but there was no statistically significant difference between the sexes in the third semester of the Master degree students. Conclusion: Bachelor and Master students' positive attitudes toward physical science is affected by their gender and women pay more attention to learn treatment physiologically details, while men are more likely to emphasize on the results of the treatment. By increasing the presence of women in Master degrees their attitude get closer to men.

Interprofessional education and the basic sciences: Rationale and outcomes.

Science.gov (United States)

Thistlethwaite, Jill E

2015-01-01

Interprofessional education (IPE) aims to improve patient outcomes and the quality of care. Interprofessional learning outcomes and interprofessional competencies are now included in many countries' health and social care professions' accreditation standards. While IPE may take place at any time in health professions curricula it tends to focus on professionalism and clinical topics rather than basic science activities. However generic interprofessional competencies could be included in basic science courses that are offered to at least two different professional groups. In developing interprofessional activities at the preclinical level, it is important to define explicit interprofessional learning outcomes plus the content and process of the learning. Interprofessional education must involve interactive learning processes and integration of theory and practice. This paper provides examples of IPE in anatomy and makes recommendations for course development and evaluation. © 2015 American Association of Anatomists.

Educational Status of Dental Basic Science Course and its Correlation with Students' Educational Background in Kermanshah University of Medical Sciences

Directory of Open Access Journals (Sweden)

Mozafar Khazaei

2014-04-01

Full Text Available Introduction: Basic science course plays a pivotal role in the academic achievement of the students. The scientific background and educational performance of the students are also influential in this period. The aim of the present study was to investigate the educational status of dental basic science course in the first three admissions (2009-2011 and its association with students’ educational background in Kermanshah University of Medical Sciences (KUMS. Methods: In this descriptive cross-sectional study, all dental students admitted to school of dentistry in 2009-2011 years were included. The students’ academic background (scores, grade point average, score of comprehensive basic sciences examination (CBSE were recorded. Data were analyzed by SPSS 16 using one-way analysis of variance (ANOVA and independent t-test. Results: Kermanshah dental students admitted to university in 2009-2011 were mostly female (59.2%, belonged to regions 2 and 3 (81.6% of university entrance exam, had sciences diploma (89.8% and their grade point average of diploma was nearly 18. There was a significant difference between the three groups of students admitted to university in Biology, Chemistry, Mathematics, Arabic, English language and Theology lessones of entrane exam (P<0.05. The students’ failure rate was 1.5% in university coureses. They all (100% passed CBSE and were ranked second nationally in the year. There was no significant difference between male and female students in terms of age, diploma grade point average, grade point average of basic sciences and score of CBSE. Conclusion: Basic science courses of dentistry in Kermanshah enjoyed a rather constant status and students had a good academic level in these courses.

Longitudinal study of self-awakening and sleep/wake habits in adolescents

Directory of Open Access Journals (Sweden)

Ikeda H

2012-09-01

Full Text Available Hiroki Ikeda,1 Mitsuo Hayashi21Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo; 2Department of Behavioral Sciences, Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, JapanAbstract: Self-awakening is the ability to awaken without external assistance at a predetermined time. Cross-sectional studies reported that people who self-awaken have sleep/wake habits different from those of people who use external means to wake from sleep. However, no longitudinal study has examined self-awakening. The present study investigated self-awakening, both habitual and inconsistent, compared to awakening by external means in relation to sleep/wake schedules for five consecutive years in 362 students (starting at mean age 15.1 ± 0.3 years. Students who self-awakened consistently for five consecutive years (5% of all students went to bed earlier than those who inconsistently self-awakened (mixed group, 40% or consistently used forced awakening by external means (56%. Awakening during sleep was more frequent and sleep was lighter in the consistently self-awakened group than in the mixed and consistently forced-awakened groups. However, daytime dozing was less frequent and comfort immediately after awakening was greater for the consistently self-awakened group than for the mixed and consistently forced-awakened groups. These results indicate that the three groups have different sleep/wake habits. Previous studies of self-awakening using cross-sectional survey data may have confounded both consistent and inconsistent self-awakening habits. A longitudinal study is necessary to clarify the relationship between the self-awakening habit and sleep/wake patterns.Keywords: habitual self-awakening, sleep/wake pattern, adolescent

Basic Science for a Secure Energy Future

Science.gov (United States)

Horton, Linda

2010-03-01

Anticipating a doubling in the world's energy use by the year 2050 coupled with an increasing focus on clean energy technologies, there is a national imperative for new energy technologies and improved energy efficiency. The Department of Energy's Office of Basic Energy Sciences (BES) supports fundamental research that provides the foundations for new energy technologies and supports DOE missions in energy, environment, and national security. The research crosses the full spectrum of materials and chemical sciences, as well as aspects of biosciences and geosciences, with a focus on understanding, predicting, and ultimately controlling matter and energy at electronic, atomic, and molecular levels. In addition, BES is the home for national user facilities for x-ray, neutron, nanoscale sciences, and electron beam characterization that serve over 10,000 users annually. To provide a strategic focus for these programs, BES has held a series of ``Basic Research Needs'' workshops on a number of energy topics over the past 6 years. These workshops have defined a number of research priorities in areas related to renewable, fossil, and nuclear energy -- as well as cross-cutting scientific grand challenges. These directions have helped to define the research for the recently established Energy Frontier Research Centers (EFRCs) and are foundational for the newly announced Energy Innovation Hubs. This overview will review the current BES research portfolio, including the EFRCs and user facilities, will highlight past research that has had an impact on energy technologies, and will discuss future directions as defined through the BES workshops and research opportunities.

The Relationship between Immediate Relevant Basic Science Knowledge and Clinical Knowledge: Physiology Knowledge and Transthoracic Echocardiography Image Interpretation

Science.gov (United States)

Nielsen, Dorte Guldbrand; Gotzsche, Ole; Sonne, Ole; Eika, Berit

2012-01-01

Two major views on the relationship between basic science knowledge and clinical knowledge stand out; the Two-world view seeing basic science and clinical science as two separate knowledge bases and the encapsulated knowledge view stating that basic science knowledge plays an overt role being encapsulated in the clinical knowledge. However, resent…

The basic science of bone marrow aspirate concentrate in chondral injuries

Directory of Open Access Journals (Sweden)

James Holton

2016-09-01

Full Text Available There has been great interest in bone marrow aspirate concentrate (BMAC as a cost effective method in delivering mesenchymal stem cells (MSCs to aid in the repair and regeneration of cartilage defects. Alongside MSCs, BMAC contains a range of growth factors and cytokines to support cell growth following injury. However, there is paucity of information relating to the basic science underlying BMAC and its exact biological role in supporting the growth and regeneration of chondrocytes. The focus of this review is the basic science underlying BMAC in relation to chondral damage and regeneration.

Japanese representation in leading general medicine and basic science journals: a comparison of two decades.

Science.gov (United States)

Fukui, Tsuguya; Takahashi, Osamu; Rahman, Mahbubur

2013-11-01

During 1991-2000, Japan contribution to the top general medicine journals was very small although the contribution to the top basic science journals was sizeable. However, it has not been examined whether the contribution to the top general medicine and basic science journals has changed during the last decade (2001-2010). The objective of this study was to compare Japan representation in high-impact general medicine and basic science journals between the years 1991-2000 and 2001-2010. We used PubMed database to examine the frequency of articles originated from Japan and published in 7 high-impact general medicine and 6 high-impact basic science journals. Several Boolean operators were used to connect name of the journal, year of publication and corresponding authors' affiliation in Japan. Compared to the 1991-2000 decade, Japan contribution to the top general medicine journals did not increase over the 2001-2010 period (0.66% vs. 0.74%, P = 0.255). However, compared to the same period, its contribution to the top basic science journals increased during 2001-2010 (2.51% vs. 3.60%, P journals showed an upward trend over the 1991-2000 period (P general medicine journals remained flat both during 1991-2000 (P = 0.273) and 2001-2010 (P = 0.073). Overall, Japan contribution to the top general medicine journals has remained small and unchanged over the last two decades. However, top basic science journals had higher Japan representation during 2001-2010 compared to 1991-2000.

Evaluation of Fast-Time Wake Vortex Models using Wake Encounter Flight Test Data

Science.gov (United States)

Ahmad, Nashat N.; VanValkenburg, Randal L.; Bowles, Roland L.; Limon Duparcmeur, Fanny M.; Gloudesman, Thijs; van Lochem, Sander; Ras, Eelco

2014-01-01

This paper describes a methodology for the integration and evaluation of fast-time wake models with flight data. The National Aeronautics and Space Administration conducted detailed flight tests in 1995 and 1997 under the Aircraft Vortex Spacing System Program to characterize wake vortex decay and wake encounter dynamics. In this study, data collected during Flight 705 were used to evaluate NASA's fast-time wake transport and decay models. Deterministic and Monte-Carlo simulations were conducted to define wake hazard bounds behind the wake generator. The methodology described in this paper can be used for further validation of fast-time wake models using en-route flight data, and for determining wake turbulence constraints in the design of air traffic management concepts.

Students' Self-Concept and Their Achievement in Basic Science ...

African Journals Online (AJOL)

The study investigated the relationship between students self-concept andtheir academic performance in Basic Science. It further examines genderdifference in students performance. The study adopted ex-post factorresearch design and made use of 300 students all from Public Schools. Theadapted Version of ...

Introduction to wakefields and wake potentials

Energy Technology Data Exchange (ETDEWEB)

Wilson, P.B.

1989-01-01

What are wakefields and wake potentials, and why are these concepts useful in the physics of linear accelerators and storage rings We approach this question by first reviewing the basic physical concepts which underlie the mathematical formalism. We then present a summary of the various techniques that have been developed to make detailed calculations of wake potentials. Finally, we give some applications to current problems of interest in accelerator physics. No attempt at completeness can be made in an introductory article of modest length. Rather, we try to give a broad overview and to list key references for more detailed study. It will also be apparent that the last chapter on this subject, with all the loose ends neatly tied up, has yet to be written. There are subtle points, there are controversial questions, and active calculations to resolve these questions are continuing at the time of this writing. 61 refs., 10 figs., 1 tab.

Introduction to wakefields and wake potentials

International Nuclear Information System (INIS)

Wilson, P.B.

1989-01-01

What are wakefields and wake potentials, and why are these concepts useful in the physics of linear accelerators and storage rings? We approach this question by first reviewing the basic physical concepts which underlie the mathematical formalism. We then present a summary of the various techniques that have been developed to make detailed calculations of wake potentials. Finally, we give some applications to current problems of interest in accelerator physics. No attempt at completeness can be made in an introductory article of modest length. Rather, we try to give a broad overview and to list key references for more detailed study. It will also be apparent that the last chapter on this subject, with all the loose ends neatly tied up, has yet to be written. There are subtle points, there are controversial questions, and active calculations to resolve these questions are continuing at the time of this writing. 61 refs., 10 figs., 1 tab

Journal of Basic and Clinical Reproductive Sciences: A New Baby ...

African Journals Online (AJOL)

Journal of Basic and Clinical Reproductive Sciences · January - December ... determined with certainty as some cases are asymptomatic .... Bangal et al. reported a rare case of Peritonitis ... following emergency exploratory laparotomy and.

Proceedings of the meeting and scientific presentations on basic science research and nuclear technology

International Nuclear Information System (INIS)

Prayitno; Slamet Santosa; Darsono; Syarip; Agus Taftazani; Samin; Tri Mardji Atmono; Dwi Biyantoro; Herry Poernomo; Prajitno; Tjipto Sujitno; Gede Sutresna W; Djoko Slamet Pujorahardjo; Budi Setiawan; Bambang Siswanto; Endro Kismolo; Jumari

2016-08-01

The Proceedings of the Meeting and Scientific Presentations on Basic Science Research and Nuclear Technology by Center for Accelerator Science and Technology in Yogyakarta with the theme of Universities and research and development institutions synergy in the development of basic science and nuclear technology held on Surakarta 9 August 2016. This seminar is an annual routine activities of Center for Accelerator Science and Technology for exchange research result among University and BATAN researcher for using nuclear technology. The proceeding consist of 3 article from keynotes’ speaker and 37 articles from BATAN participant as well as outside which have been indexed separately. (MPN)

Support of a Problem-Based Learning Curriculum by Basic Science Faculty

Directory of Open Access Journals (Sweden)

William L. Anderson

2002-11-01

Full Text Available Although published reports describe benefits to students of learning in a problem-based, student-centered environment, questions have persisted about the excessive faculty time commitments associated with the implementation of PBL pedagogy. The argument has been put forward that the excessive faculty costs of such a curriculum cannot be justified based upon the potential benefits to students. However, the magnitude of the faculty time commitment to a PBL curriculum to support the aforementioned argument is not clear to us and we suspect that it is also equally unclear to individuals charged with making resource decisions supporting the educational efforts of the institution. Therefore, to evaluate this cost - benefit question, we analyzed the actual basic science faculty time commitment in a hybrid PBL curriculum during the first phase 18 months of undergraduate medical education. The results of this analysis do demonstrate an increase in faculty time commitments but do not support the argument that PBL pedagogy is excessively costly in terms of faculty time. For the year analyzed in this report, basic science faculty members contributed on average of 27.4 hours to the instruction of medical students. The results of the analysis did show significant contributions (57% of instructional time by the clinical faculty during the initial 18 months of medical school. In addition, the data revealed a four-fold difference between time commitments of the four basic science departments. We conclude that a PBL curriculum does not place unreasonable demands on the time of basic science faculty. The demands on clinical faculty, in the context of their other commitments, could not be evaluated. Moreover, this type of analysis provides a tool that can be used to make faculty resource allocation decisions fairly.

Development and Validation of the Life Sciences Assessment: A Measure of Preschool Children's Conceptions of Basic Life Sciences

Science.gov (United States)

Maherally, Uzma Nooreen

2014-01-01

The purpose of this study was to develop and validate a science assessment tool termed the Life Sciences Assessment (LSA) in order to assess preschool children's conceptions of basic life sciences. The hypothesis was that the four sub-constructs, each of which can be measured through a series of questions on the LSA, will make a significant…

White Paper on Nuclear Data Needs and Capabilities for Basic Science

Energy Technology Data Exchange (ETDEWEB)

Batchelder, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kawano, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kelley, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kondev, F. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCutchan, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sonzogni, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thoennessen, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, I. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-05-14

Reliable nuclear structure and reaction data represent the fundamental building blocks of nuclear physics and astrophysics research, and are also of importance in many applications. There is a continuous demand for high-quality updates of the main nuclear physics databases via the prompt compilation and evaluation of the latest experimental and theoretical results. The nuclear physics research community benefits greatly from comprehensive, systematic and up-to-date reviews of the experimentally determined nuclear properties and observables, as well as from the ability to rapidly access these data in user-friendly forms. Such credible databases also act as a bridge between science, technology, and society by making the results of basic nuclear physics research available to a broad audience of users, and hence expand the societal utilization of nuclear science. Compilation and evaluation of nuclear data has deep roots in the history of nuclear science research, as outlined in Appendix 1. They have an enormous impact on many areas of science and applications, as illustrated in Figure 2 for the Evaluated Nuclear Structure Data File (ENSDF) database. The present workshop concentrated on the needs of the basic nuclear science community for data and capabilities. The main role of this community is to generate and use data in order to understand the basic nuclear forces and interactions that are responsible for the existence and the properties of all nuclides and, as a consequence, to gain knowledge about the origins, evolution and structure of the universe. Thus, the experiments designed to measure a wealth of nuclear properties towards these fundamental scientific goals are typically performed from within this community.

PNNL Highlights for the Office of Basic Energy Sciences (July 2013-July 2014)

Energy Technology Data Exchange (ETDEWEB)

Anderson, Benjamin; Warren, Pamela M.; Manke, Kristin L.

2014-08-13

This report includes research highlights of work funded in part or whole by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences as well as selected leadership accomplishments.

Basic science of nuclear medicine

International Nuclear Information System (INIS)

Parker, R.P.; Taylor, D.M.; Smith, P.H.S.

1978-01-01

A book has been written presenting those aspects of physics, chemistry and related sciences which are essential to a clear understanding of the scientific basis of nuclear medicine. Part I covers the basic physics of radiation and radioactivity. Part II deals with radiation dosimetry, the biological effects of radiation and the principles of tracer techniques. The measurement of radioactivity and the principal aspects of modern instrumentation are presented in Part III. Those aspects of chemistry relevant to the preparation and use of radiopharmaceuticals are discussed in Part IV. The final section is concerned with the production of radionuclides and radiopharmaceuticals and with the practical aspects of laboratory practice, facilities and safety. The book serves as a general introductory text for physicians, scientists, radiographers and technicians who are entering nuclear medicine. (U.K.)

Science Awareness and Science Literacy through the Basic Physics Course: Physics with a bit of Metaphysics?

Science.gov (United States)

Rusli, Aloysius

2016-08-01

Until the 1980s, it is well known and practiced in Indonesian Basic Physics courses, to present physics by its effective technicalities: The ideally elastic spring, the pulley and moving blocks, the thermodynamics of ideal engine models, theoretical electrostatics and electrodynamics with model capacitors and inductors, wave behavior and its various superpositions, and hopefully closed with a modern physics description. A different approach was then also experimented with, using the Hobson and Moore texts, stressing the alternative aim of fostering awareness, not just mastery, of science and the scientific method. This is hypothesized to be more in line with the changed attitude of the so-called Millenials cohort who are less attentive if not interested, and are more used to multi-tasking which suits their shorter span of attention. The upside is increased awareness of science and the scientific method. The downside is that they are getting less experience of the scientific method which intensely bases itself on critical observation, analytic thinking to set up conclusions or hypotheses, and checking consistency of the hypotheses with measured data. Another aspect is recognition that the human person encompasses both the reasoning capacity and the mental- spiritual-cultural capacity. This is considered essential, as the world grows even smaller due to increased communication capacity, causing strong interactions, nonlinear effects, and showing that value systems become more challenging and challenged due to physics / science and its cosmology, which is successfully based on the scientific method. So students should be made aware of the common basis of these two capacities: the assumptions, the reasoning capacity and the consistency assumption. This shows that the limits of science are their set of basic quantifiable assumptions, and the limits of the mental-spiritual-cultural aspects of life are their set of basic metaphysical (non-quantifiable) assumptions. The

Science Awareness and Science Literacy through the Basic Physics Course: Physics with a bit of Metaphysics?

International Nuclear Information System (INIS)

Rusli, Aloysius

2016-01-01

Until the 1980s, it is well known and practiced in Indonesian Basic Physics courses, to present physics by its effective technicalities: The ideally elastic spring, the pulley and moving blocks, the thermodynamics of ideal engine models, theoretical electrostatics and electrodynamics with model capacitors and inductors, wave behavior and its various superpositions, and hopefully closed with a modern physics description. A different approach was then also experimented with, using the Hobson and Moore texts, stressing the alternative aim of fostering awareness, not just mastery, of science and the scientific method. This is hypothesized to be more in line with the changed attitude of the so-called Millenials cohort who are less attentive if not interested, and are more used to multi-tasking which suits their shorter span of attention. The upside is increased awareness of science and the scientific method. The downside is that they are getting less experience of the scientific method which intensely bases itself on critical observation, analytic thinking to set up conclusions or hypotheses, and checking consistency of the hypotheses with measured data. Another aspect is recognition that the human person encompasses both the reasoning capacity and the mental- spiritual-cultural capacity. This is considered essential, as the world grows even smaller due to increased communication capacity, causing strong interactions, nonlinear effects, and showing that value systems become more challenging and challenged due to physics / science and its cosmology, which is successfully based on the scientific method. So students should be made aware of the common basis of these two capacities: the assumptions, the reasoning capacity and the consistency assumption. This shows that the limits of science are their set of basic quantifiable assumptions, and the limits of the mental-spiritual-cultural aspects of life are their set of basic metaphysical (non-quantifiable) assumptions. The

Basic science of nuclear medicine the bare bone essentials

CERN Document Server

Lee, Kai H

2015-01-01

Through concise, straightforward explanations and supporting graphics that bring abstract concepts to life, the new Basic Science of Nuclear Medicine—the Bare Bone Essentials is an ideal tool for nuclear medicine technologist students and nuclear cardiology fellows looking for an introduction to the fundamentals of the physics and technologies of modern day nuclear medicine.

Very long-term retention of basic science knowledge in doctors after graduation.

Science.gov (United States)

Custers, Eugène J F M; Ten Cate, Olle T J

2011-04-01

Despite frequent complaints that biomedical knowledge is quickly forgotten after it has been learned, few investigations of actual long-term retention of basic science knowledge have been conducted in the medical domain. Our aim was to illuminate the long-term retention of basic science knowledge, particularly of unrehearsed knowledge. Using a cross-sectional study design, medical students and doctors in the Netherlands were tested for retention of basic science knowledge. Relationships between retention interval and proportion of correct answers on a knowledge test were investigated. The popular notion that most of basic science knowledge is forgotten shortly after graduation is not supported by our findings. With respect to the full test scores, which reflect a composite of unrehearsed and rehearsed knowledge, performance decreased from approximately 40% correct answers for students still in medical school, to 25-30% correct answers for doctors after many years of practice. When rehearsal during the retention interval is controlled for, it appears that little knowledge is lost for 1.5-2 years after it was last used; from then on, retention is best described by a negatively accelerated (logarithmic) forgetting curve. After ≥ 25 years, retention levels were in the range of 15-20%. Conclusions about the forgetting of unrehearsed knowledge in this study are in line with findings reported in other domains: it proceeds in accordance with the Ebbinghaus curve for meaningful material, except that in our findings the 'downward' part appears to start later than in most other studies. The limitations of the study are discussed and possible ramifications for medical education are proposed. © Blackwell Publishing Ltd 2011.

Defense, basic, and industrial research at the Los Alamos Neutron Science Center: Proceedings

Energy Technology Data Exchange (ETDEWEB)

Longshore, A.; Salgado, K. [comps.

1995-10-01

The Workshop on Defense, Basic, and Industrial Research at the Los Alamos Neutron Science Center gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss the use of neutrons in science-based stockpile stewardship, The workshop began with presentations by government officials, senior representatives from the three weapons laboratories, and scientific opinion leaders. Workshop participants then met in breakout sessions on the following topics: materials science and engineering; polymers, complex fluids, and biomaterials; fundamental neutron physics; applied nuclear physics; condensed matter physics and chemistry; and nuclear weapons research. They concluded that neutrons can play an essential role in science-based stockpile stewardship and that there is overlap and synergy between defense and other uses of neutrons in basic, applied, and industrial research from which defense and civilian research can benefit. This proceedings is a collection of talks and papers from the plenary, technical, and breakout session presentations. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Annual report, Basic Sciences Branch, FY 1991

Energy Technology Data Exchange (ETDEWEB)

1993-04-01

This report summarizes the progress of the Basic Sciences Branch of the National Renewable Energy Laboratory (NREL) from October 1, 1990, through September 30, 1991. Seven technical sections of the report cover these main areas of NREL`s in-house research: Semiconductor Crystal Growth, Amorphous Silicon Research, Polycrystalline Thin Films, III-V High-Efficiency Photovoltaic Cells, Solid-State Theory, Solid-State Spectroscopy, and Superconductivity. Each section explains the purpose and major accomplishments of the work in the context of the US Department of Energy`s National Photovoltaic Research Program plans.

Annual report, Basic Sciences Branch, FY 1991

Energy Technology Data Exchange (ETDEWEB)

1993-04-01

This report summarizes the progress of the Basic Sciences Branch of the National Renewable Energy Laboratory (NREL) from October 1, 1990, through September 30, 1991. Seven technical sections of the report cover these main areas of NREL's in-house research: Semiconductor Crystal Growth, Amorphous Silicon Research, Polycrystalline Thin Films, III-V High-Efficiency Photovoltaic Cells, Solid-State Theory, Solid-State Spectroscopy, and Superconductivity. Each section explains the purpose and major accomplishments of the work in the context of the US Department of Energy's National Photovoltaic Research Program plans.

Spectral coherence in windturbine wakes

Energy Technology Data Exchange (ETDEWEB)

Hojstrup, J. [Riso National Lab., Roskilde (Denmark)

1996-12-31

This paper describes an experiment at a Danish wind farm to investigate the lateral and vertical coherences in the nonequilibrium turbulence of a wind turbine wake. Two meteorological masts were instrumented for measuring profiles of mean speed, turbulence, and temperature. Results are provided graphically for turbulence intensities, velocity spectra, lateral coherence, and vertical coherence. The turbulence was somewhat influenced by the wake, or possibly from aggregated wakes further upstream, even at 14.5 diameters. Lateral coherence (separation 5m) seemed to be unaffected by the wake at 7.5 diameters, but the flow was less coherent in the near wake. The wake appeared to have little influence on vertical coherence (separation 13m). Simple, conventional models for coherence appeared to be adequate descriptions for wake turbulence except for the near wake situation. 3 refs., 7 figs., 1 tab.

Vertical integration of basic science in final year of medical education.

Science.gov (United States)

Rajan, Sudha Jasmine; Jacob, Tripti Meriel; Sathyendra, Sowmya

2016-01-01

Development of health professionals with ability to integrate, synthesize, and apply knowledge gained through medical college is greatly hampered by the system of delivery that is compartmentalized and piecemeal. There is a need to integrate basic sciences with clinical teaching to enable application in clinical care. To study the benefit and acceptance of vertical integration of basic science in final year MBBS undergraduate curriculum. After Institutional Ethics Clearance, neuroanatomy refresher classes with clinical application to neurological diseases were held as part of the final year posting in two medical units. Feedback was collected. Pre- and post-tests which tested application and synthesis were conducted. Summative assessment was compared with the control group of students who had standard teaching in other two medical units. In-depth interview was conducted on 2 willing participants and 2 teachers who did neurology bedside teaching. Majority (>80%) found the classes useful and interesting. There was statistically significant improvement in the post-test scores. There was a statistically significant difference between the intervention and control groups' scores during summative assessment (76.2 vs. 61.8 P Vertical integration of basic science in final year was beneficial and resulted in knowledge gain and improved summative scores. The classes were found to be useful, interesting and thought to help in clinical care and application by majority of students.

Appraisal of ALM predictions of turbulent wake features

Science.gov (United States)

Rocchio, Benedetto; Cilurzo, Lorenzo; Ciri, Umberto; Salvetti, Maria Vittoria; Leonardi, Stefano

2017-11-01

Wind turbine blades create a turbulent wake that may persist far downstream, with significant implications on wind farm design and on its power production. The numerical representation of the real blade geometry would lead to simulations beyond the present computational resources. We focus our attention on the Actuator Line Model (ALM), in which the blade is replaced by a rotating line divided into finite segments with representative aerodynamic coefficients. The total aerodynamic force is projected along the computational axis and, to avoid numerical instabilities, it is distributed among the nearest grid points by using a Gaussian regularization kernel. The standard deviation of this kernel is a fundamental parameter that strongly affects the characteristics of the wake. We compare here the wake features obtained in direct numerical simulations of the flow around 2D bodies (a flat plate and an airfoil) modeled using the Immersed Boundary Method with the results of simulations in which the body is modeled by ALM. In particular, we investigate whether the ALM is able to reproduce the mean velocity field and the turbulent kinetic energy in the wake for the considered bodies at low and high angles of attack and how this depends on the choice of the ALM kernel. S. Leonardi was supported by the National Science Foundation, Grant No. 1243482 (the WINDINSPIRE project).

Coordinating the undergraduate medical (MBBS basic sciences programme in a Nepalese medical school

Directory of Open Access Journals (Sweden)

Shankar PR

2011-06-01

Full Text Available KIST Medical College follows the curriculum of the Institute ofMedicine, Tribhuvan University. The programme aims toproduce socially responsible and competent physicians whoare willing and able to meet the existing and emergingchallenges of the national and international healthcaresystem. The first cohort of undergraduate medical students(MBBS students was admitted in November 2008 and threecohorts including the one admitted in 2008 have beenadmitted at the time of writing. The basic science subjects aretaught in an integrated, organ-system-based manner withcommunity medicine during the first two years. I wasappointed as the MBBS Phase I programme coordinator inSeptember 2008 and in this article I share my experiences ofrunning the basic sciences programme and also offersuggestions for running an efficient academic programme. Themanuscript will be of special interest to readers runningundergraduate medical programmes. The reader canunderstand our experiences in running the programme inadverse circumstances, learning to achieve greater integrationamong basic science, community medicine and clinicaldepartments, obtain information about a communitydiagnosis programme and know about running specialmodules on the medical humanities and pharmaceuticalpromotion.

Cystic fibrosis: Beyond the airways. Report on the meeting of the basic science working group in Loutraki, Greece.

Science.gov (United States)

Amaral, Margarida D; Boj, Sylvia F; Shaw, James; Leipziger, Jens; Beekman, Jeffrey M

2018-06-01

The European Cystic Fibrosis Society (ECFS) Basic Science Working Group (BSWG) organized a session on the topic "Cystic Fibrosis: Beyond the Airways", within the 15th ECFS Basic Science Conference which gathered around 200 researchers working in the basic science of CF. The session was organized and chaired by Margarida Amaral (BioISI, University of Lisboa, Portugal) and Jeffrey Beekman (University Medical Centre Utrecht, Netherlands) as Chair and Vice-Chair of the BSWG and its purpose was to bring attention of participants of the ECFS Basic Science Conference to "more forgotten" organs in CF disease. In this report we attempt to review and integrate the ideas that emerged at the session. Copyright © 2018 European Cystic Fibrosis Society. All rights reserved.

Longitudinal effects of near-uniform beam-wall wake fields

International Nuclear Information System (INIS)

Ruggiero, A.G.; Talmann, R.

1979-01-01

Several theories have been developed in the past to explain longitudinal instabilities of individual bunches in particle accelerators and storage rings. But they are less than satisfactory because in one way or another they rely on some mathematical approximation of doubtful physical meaning. Here, the basic physical model is simplified in order to help to understand a little better the physics involved. Initially, the motion of two particles executing phase oscillations in the same bunch under the influence of the wake field generated by the other is investigated. This motion is stable and bounded even for the case of a slowly varying wake field. But the distortions of the trajectories can, nevertheless, be significant and can be interpreted as bunch lengthening and widening. These models generalized to an N particle model. If the wake field is constant, the equations are simple enough that it is possible to solve exactly for the intensity-limited, self-consistent, longitudinal particle distribution. It is not necessary to solve, or even introduce, the Vlasov equation. These models exhibit effects like dipole and quadrupole oscillations and bunch lengthening, in qualitative agreement with observed behavior, but no attempt has been made at quantitative comparison with observation

Ciencia básica y ciencia aplicada Basic science and applied science

Directory of Open Access Journals (Sweden)

Ruy Pérez-Tamayo

2001-08-01

://www.insp.mx/salud/index.htmlA lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico´s National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html

Spectral function calculation of angle wakes, wake moments, and misalignment wakes for the SLAC Damped Detuned Structures (DDS)

International Nuclear Information System (INIS)

Jones, R.M.; Miller, R.H.; Kroll, N.M.

1997-05-01

Transverse wake functions so far reported for the SLAC DDS have been limited to those caused by uniform offset of the drive beam in a straight perfectly aligned structure. The complete description of the betatron oscillations of wake coupled bunches requires an array of wake functions, referred to as moments. Modifications of these arrays induced by structure misalignments are also of interest. In this paper we express the array elements in terms of a spectral function array. Examples are given based upon DDS1

Systematic Approach to Remediation in Basic Science Knowledge for Preclinical Students: A case study

Science.gov (United States)

Amara, Francis

Remediation of pre-clerkship students for deficits in basic science knowledge should help them overcome their learning deficiencies prior to clerkship. However, very little is known about remediation in basic science knowledge during pre-clerkship. This study utilized the program theory framework to collect and organize mixed methods data of the remediation plan for pre-clerkship students who failed their basic science cognitive examinations in a Canadian medical school. This plan was analyzed using a logic model narrative approach and compared to literature on the learning theories. The analysis showed a remediation plan that was strong on governance and verification of scores, but lacked: clarity and transparency of communication, qualified remedial tutors, individualized diagnosis of learner's deficits, and student centered learning. Participants admitted uncertainty about the efficacy of the remediation process. A remediation framework is proposed that includes student-centered participation, individualized learning plan and activities, deliberate practice, feedback, reflection, and rigorous reassessment.

Basic and Applied Research at the Los Alamos Neutron Science Center

International Nuclear Information System (INIS)

Lisowski, P.W.

2003-01-01

The Los Alamos Neutron Science Center, or LANSCE, is an accelerator-based national user facility for research in basic and applied science. At present LANSCE has two experimental areas primarily using neutrons generated by 800-MeV protons striking tungsten target systems. A third area uses the proton beam for radiography. This paper describes the three LANSCE experimental areas, gives highlights of the past operating period, and discusses plans for the future

Science for Energy Technology: Strengthening the Link Between Basic Research and Industry

Energy Technology Data Exchange (ETDEWEB)

None

2010-04-01

The nation faces two severe challenges that will determine our prosperity for decades to come: assuring clean, secure, and sustainable energy to power our world, and establishing a new foundation for enduring economic and jobs growth. These challenges are linked: the global demand for clean sustainable energy is an unprecedented economic opportunity for creating jobs and exporting energy technology to the developing and developed world. But achieving the tremendous potential of clean energy technology is not easy. In contrast to traditional fossil fuel-based technologies, clean energy technologies are in their infancy, operating far below their potential, with many scientific and technological challenges to overcome. Industry is ultimately the agent for commercializing clean energy technology and for reestablishing the foundation for our economic and jobs growth. For industry to succeed in these challenges, it must overcome many roadblocks and continuously innovate new generations of renewable, sustainable, and low-carbon energy technologies such as solar energy, carbon sequestration, nuclear energy, electricity delivery and efficiency, solid state lighting, batteries and biofuels. The roadblocks to higher performing clean energy technology are not just challenges of engineering design but are also limited by scientific understanding.Innovation relies on contributions from basic research to bridge major gaps in our understanding of the phenomena that limit efficiency, performance, or lifetime of the materials or chemistries of these sustainable energy technologies. Thus, efforts aimed at understanding the scientific issues behind performance limitations can have a real and immediate impact on cost, reliability, and performance of technology, and ultimately a transformative impact on our economy. With its broad research base and unique scientific user facilities, the DOE Office of Basic Energy Sciences (BES) is ideally positioned to address these needs. BES has laid

Wind Turbines Wake Aerodynamics

DEFF Research Database (Denmark)

Vermeer, L.; Sørensen, Jens Nørkær; Crespo, A.

2003-01-01

The aerodynamics of horizontal axis wind turbine wakes is studied. The contents is directed towards the physics of power extraction by wind turbines and reviews both the near and the far wake region. For the near wake, the survey is restricted to uniform, steady and parallel flow conditions......, thereby excluding wind shear, wind speed and rotor setting changes and yawed conditions. The emphasis is put on measurements in controlled conditions.For the far wake, the survey focusses on both single turbines and wind farm effects, and the experimental and numerical work are reviewed; the main interest...... is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines.The article is further restricted to horizontal axis wind turbines and excludes all other types of turbines....

A review of second law techniques applicable to basic thermal science research

Science.gov (United States)

Drost, M. Kevin; Zamorski, Joseph R.

1988-11-01

This paper reports the results of a review of second law analysis techniques which can contribute to basic research in the thermal sciences. The review demonstrated that second law analysis has a role in basic thermal science research. Unlike traditional techniques, second law analysis accurately identifies the sources and location of thermodynamic losses. This allows the development of innovative solutions to thermal science problems by directing research to the key technical issues. Two classes of second law techniques were identified as being particularly useful. First, system and component investigations can provide information of the source and nature of irreversibilities on a macroscopic scale. This information will help to identify new research topics and will support the evaluation of current research efforts. Second, the differential approach can provide information on the causes and spatial and temporal distribution of local irreversibilities. This information enhances the understanding of fluid mechanics, thermodynamics, and heat and mass transfer, and may suggest innovative methods for reducing irreversibilities.

Noise emission from wind turbines in wake. Project report

Energy Technology Data Exchange (ETDEWEB)

Dam Madsen, K.; Plovsing, B. (DELTA, Hoersholm (Denmark)); Soerensen, Thomas (EMD International A/S, Aalborg (Denmark)); Aagaard Madsen, H.; Bertagnolio, F. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark))

2011-03-15

observer position close to the ground directly downwind of the wind turbine the major part of the noise is received from the part of the rotor plane with downwards movement of the blades. Although it has not been possible to get a precise estimation of the effect on the noise generation for a given wake degree, a study of wake effects for different layout of wind farms due to the general wind speed reduction in wake has been made using the WindPRO Nord2000 program. The basic assumption for this study has been that a turbine operating in wake radiates the same noise as a turbine with free inflow at the same power output. From this study it is seen the largest reduction of noise at the receptors is when the closest turbines are in a deep wake, whereas if the deep wake is elsewhere in the wind farm the noise reduction is less. For different wind farm layout it is concluded that the combined wake influence on the noise impact is a complex function of wind direction, wind speed and wind farm geometry. It may cause deviations from the undisturbed noise impact of several dB, both up and down, and the effect may change rapidly with small changes in wind direction. (Author)

Wake effects on Middelgrund Windfarm

DEFF Research Database (Denmark)

Ejsing Jørgensen, Hans; Frandsen, S.; Vølund, P.

2003-01-01

This report describes the data analysis of the Middelgrund Wind Farm online collected data with the purpose of calculating the wake effects and turbulence intensities within the wind farm when maximum wake effects are present. The data are compared to themost commonly used wake model PARK...... decreasing wind speed through the array when the wind iscoming from north. The turbulence intensity is enhanced up to 0.3 due to the wake effects. The analysis has shown that this enhancement is nearly independent of the number of turbines involved in the wake creation....

The Sequencing of Basic Chemistry Topics by Physical Science Teachers

Science.gov (United States)

Sibanda, Doras; Hobden, Paul

2016-01-01

The purpose of this study was to find out teachers' preferred teaching sequence for basic chemistry topics in Physical Science in South Africa, to obtain their reasons underpinning their preferred sequence, and to compare these sequences with the prescribed sequences in the current curriculum. The study was located within a pragmatic paradigm and…

Electron-Cloud Wake Fields

CERN Document Server

Rumolo, Giovanni

2002-01-01

The electron cloud gives rise to coherent and incoherent single-bunch wake fields, both in the longitudinal and in the transverse direction, and to coherent coupled-bunch wakes. These wake fields can be computed using the simulation programs ECLOUD and HEADTAIL developed at CERN. We present the wake fields simulated for the LHC beam in the CERN SPS and at injection into the LHC in different magnetic field configurations (field-free region, dipole, and solenoid), where the magnetic field affects both the elec-tron motion during a bunch passage and the overall electron distribution in the beam pipe.

Development and Validation of a Project Package for Junior Secondary School Basic Science

Science.gov (United States)

Udofia, Nsikak-Abasi

2014-01-01

This was a Research and Developmental study designed to develop and validate projects for Junior Secondary School Basic Science instruction and evaluation. The projects were developed using the project blueprint and sent for validation by experts in science education and measurement and evaluation; using a project validation scale. They were to…

Improvements in ECN Wake Model

Energy Technology Data Exchange (ETDEWEB)

Versteeg, M.C. [University of Twente, Enschede (Netherlands); Ozdemir, H.; Brand, A.J. [ECN Wind Energy, Petten (Netherlands)

2013-08-15

Wind turbines extract energy from the flow field so that the flow in the wake of a wind turbine contains less energy and more turbulence than the undisturbed flow, leading to less energy extraction for the downstream turbines. In large wind farms, most turbines are located in the wake of one or more turbines causing the flow characteristics felt by these turbines differ considerably from the free stream flow conditions. The most important wake effect is generally considered to be the lower wind speed behind the turbine(s) since this decreases the energy production and as such the economical performance of a wind farm. The overall loss of a wind farm is very much dependent on the conditions and the lay-out of the farm but it can be in the order of 5-10%. Apart from the loss in energy production an additional wake effect is formed by the increase in turbulence intensity, which leads to higher fatigue loads. In this sense it becomes important to understand the details of wake behavior to improve and/or optimize a wind farm layout. Within this study improvements are presented for the existing ECN wake model which constructs the fundamental basis of ECN's FarmFlow wind farm wake simulation tool. The outline of this paper is as follows: first, the governing equations of the ECN wake farm model are presented. Then the near wake modeling is discussed and the results compared with the original near wake modeling and EWTW (ECN Wind Turbine Test Site Wieringermeer) data as well as the results obtained for various near wake implementation cases are shown. The details of the atmospheric stability model are given and the comparison with the solution obtained for the original surface layer model and with the available data obtained by EWTW measurements are presented. Finally the conclusions are summarized.

Utilization and acceptance of virtual patients in veterinary basic sciences - the vetVIP-project.

Science.gov (United States)

Kleinsorgen, Christin; Kankofer, Marta; Gradzki, Zbigniew; Mandoki, Mira; Bartha, Tibor; von Köckritz-Blickwede, Maren; Naim, Hassan Y; Beyerbach, Martin; Tipold, Andrea; Ehlers, Jan P

2017-01-01

Context: In medical and veterinary medical education the use of problem-based and cased-based learning has steadily increased over time. At veterinary faculties, this development has mainly been evident in the clinical phase of the veterinary education. Therefore, a consortium of teachers of biochemistry and physiology together with technical and didactical experts launched the EU-funded project "vetVIP", to create and implement veterinary virtual patients and problems for basic science instruction. In this study the implementation and utilization of virtual patients occurred at the veterinary faculties in Budapest, Hannover and Lublin. Methods: This report describes the investigation of the utilization and acceptance of students studying veterinary basic sciences using optional online learning material concurrently to regular biochemistry and physiology didactic instruction. The reaction of students towards this offer of clinical case-based learning in basic sciences was analysed using quantitative and qualitative data. Quantitative data were collected automatically within the chosen software-system CASUS as user-log-files. Responses regarding the quality of the virtual patients were obtained using an online questionnaire. Furthermore, subjective evaluation by authors was performed using a focus group discussion and an online questionnaire. Results: Implementation as well as usage and acceptance varied between the three participating locations. High approval was documented in Hannover and Lublin based upon the high proportion of voluntary students (>70%) using optional virtual patients. However, in Budapest the participation rate was below 1%. Due to utilization, students seem to prefer virtual patients and problems created in their native language and developed at their own university. In addition, the statement that assessment drives learning was supported by the observation that peak utilization was just prior to summative examinations. Conclusion: Veterinary

Opportunities for discovery: Theory and computation in Basic Energy Sciences

Energy Technology Data Exchange (ETDEWEB)

Harmon, Bruce; Kirby, Kate; McCurdy, C. William

2005-01-11

New scientific frontiers, recent advances in theory, and rapid increases in computational capabilities have created compelling opportunities for theory and computation to advance the scientific mission of the Office of Basic Energy Sciences (BES). The prospects for success in the experimental programs of BES will be enhanced by pursuing these opportunities. This report makes the case for an expanded research program in theory and computation in BES. The Subcommittee on Theory and Computation of the Basic Energy Sciences Advisory Committee was charged with identifying current and emerging challenges and opportunities for theoretical research within the scientific mission of BES, paying particular attention to how computing will be employed to enable that research. A primary purpose of the Subcommittee was to identify those investments that are necessary to ensure that theoretical research will have maximum impact in the areas of importance to BES, and to assure that BES researchers will be able to exploit the entire spectrum of computational tools, including leadership class computing facilities. The Subcommittee s Findings and Recommendations are presented in Section VII of this report.

Evaluation of Some Approved Basic Science and Technology Textbooks in Use in Junior Secondary Schools in Nigeria

Science.gov (United States)

Nwafor, C. E.; Umoke, C. C.

2016-01-01

This study was designed to evaluate the content adequacy and readability of approved basic science and technology textbooks in use in junior secondary schools in Nigeria. Eight research questions guided the study. The sample of the study consisted of six (6) approved basic science and technology textbooks, 30 Junior Secondary Schools randomly…

Spicing Up Basic Science Instruction with Storyline Strategy; What Is ...

African Journals Online (AJOL)

This study determined the effect of storyline strategy on primary school pupils‟ achievement in Basic Science with moderating effect of English Language proficiency of pupils. This study is the pre-test, post-test control group. It is a 2 x 2 quasi experimental study in which intact classes were used. This implies that the design ...

PREFACE: Wake Conference 2015

Science.gov (United States)

Barney, Andrew; Nørkær Sørensen, Jens; Ivanell, Stefan

2015-06-01

The 44 papers in this volume constitute the proceedings of the 2015 Wake Conference, held in Visby on the island of Gotland in Sweden. It is the fourth time this conference has been held. The Wake Conference series started in Visby, where it was held in 2009 and 2011. In 2013 it took place in Copenhagen where it was combined with the International Conference on Offshore Wind Energy and Ocean Energy. In 2015 it is back where it started in Visby, where it takes place at Uppsala University Campus Gotland, June 9th-11th. The global yearly production of electrical energy by wind turbines has grown tremendously in the past decade and it now comprises more than 3% of the global electrical power consumption. Today the wind power industry has a global annual turnover of more than 50 billion USD and an annual average growth rate of more than 20%. State-of-the-art wind turbines have rotor diameters of up to 150 m and 8 MW installed capacity. These turbines are often placed in large wind farms that have a total production capacity corresponding to that of a nuclear power plant. In order to make a substantial impact on one of the most significant challenges of our time, global warming, the industry's growth has to continue for a decade or two yet. This in turn requires research into the physics of wind turbine wakes and wind farms. Modern wind turbines are today clustered in wind farms in which the turbines are fully or partially influenced by the wake of upstream turbines. As a consequence, the wake behind the wind turbines has a lower mean wind speed and an increased turbulence level, as compared to the undisturbed flow outside the farm. Hence, wake interaction results in decreased total production of power, caused by lower kinetic energy in the wind, and an increase in the turbulence intensity. Therefore, understanding the physical nature of the vortices and their dynamics in the wake of a turbine is important for the optimal design of a wind farm. This conference is aimed

The Impact of Hands-On-Approach on Student Academic Performance in Basic Science and Mathematics

Science.gov (United States)

Ekwueme, Cecilia O.; Ekon, Esther E.; Ezenwa-Nebife, Dorothy C.

2015-01-01

Children can learn mathematics and sciences effectively even before being exposed to formal school curriculum if basic Mathematics and Sciences concepts are communicated to them early using activity oriented (Hands-on) method of teaching. Mathematics and Science are practical and activity oriented and can best be learnt through inquiry (Okebukola…

Wake structure and similar behavior of wake profiles downstream of a plunging airfoil

Directory of Open Access Journals (Sweden)

Ali R. DAVARI

2017-08-01

Full Text Available Very limited attention has already been paid to the velocity behavior in the wake region in unsteady aerodynamic problems. A series of tests has been performed on a flapping airfoil in a subsonic wind tunnel to study the wake structure for different sets of mean angle of attack, plunging amplitude and reduced frequency. In this study, the velocity profiles in the wake for various oscillation parameters have been measured using a wide shoulder rake, especially designed for the present experiments. The airfoil under consideration was a critical section of a 660 kW wind turbine. The results show that for a flapping airfoil the wake structure can be of drag producing type, thrust producing or neutral, depending on the mean angle of attack, oscillation amplitude and reduced frequency. In a thrust producing wake, a high-momentum high-velocity jet flow is formed in the core region of the wake instead of the conventional low-momentum flow. As a result, the drag force normally experienced by the body due to the momentum deficit would be replaced by a thrust force. According to the results, the momentum loss in the wake decreases as the reduced frequency increases. The thrust producing wake pattern for the flapping airfoil has been observed for sufficiently low angles of attack in the absence of the viscous effects. This phenomenon has also been observed for either high oscillation amplitudes or high reduced frequencies. According to the results, for different reduced frequencies and plunging amplitudes, such that the product of them be a constant, the velocity profiles exhibit similar behavior and coalesce on each other. This similarity parameter works excellently at small angles of attack. However, at near stall boundaries, the similarity is not as evident as before.

ASRS Reports on Wake Vortex Encounters

Science.gov (United States)

Connell, Linda J.; Taube, Elisa Ann; Drew, Charles Robert; Barclay, Tommy Earl

2010-01-01

ASRS is conducting a structured callback research project of wake vortex incidents reported to the ASRS at all US airports, as well as wake encounters in the enroute environment. This study has three objectives: (1) Utilize the established ASRS supplemental data collection methodology and provide ongoing analysis of wake vortex encounter reports; (2) Document event dynamics and contributing factors underlying wake vortex encounter events; and (3) Support ongoing FAA efforts to address pre-emptive wake vortex risk reduction by utilizing ASRS reporting contributions.

The Neuropsychoanalytic Approach: Using Neuroscience as the Basic Science of Psychoanalysis.

Science.gov (United States)

Johnson, Brian; Flores Mosri, Daniela

2016-01-01

Neuroscience was the basic science behind Freud's psychoanalytic theory and technique. He worked as a neurologist for 20 years before being aware that a new approach to understand complex diseases, namely the hysterias, was needed. Solms coined the term neuropsychoanalysis to affirm that neuroscience still belongs in psychoanalysis. The neuropsychoanalytic field has continued Freud's original ideas as stated in 1895. Developments in psychoanalysis that have been created or revised by the neuropsychoanalysis movement include pain/relatedness/opioids, drive, structural model, dreams, cathexis, and dynamic unconscious. Neuroscience has contributed to the development of new psychoanalytic theory, such as Bazan's (2011) description of anxiety driven by unconscious intentions or "phantoms." Results of adopting the "dual aspect monism" approach of idiographic psychoanalytic clinical observation combined with nomothetic investigation of related human phenomena include clarification and revision of theory, restoration of the scientific base of psychoanalysis, and improvement of clinical treatments. By imbricating psychoanalytic thinking with neuroscience, psychoanalysts are also positioned to make contributions to neuroscience research. Freud's original Project for a Scientific Psychology/Psychology for Neurologists can be carried forward in a way that moves psychoanalysis into the twenty-first century as a core contemporary science (Kandel, 1999). Neuroscience as the basic science of psychoanalysis both improves the field, and enhances its scientific and cultural status.

Multi-stage wake-field accelerator

International Nuclear Information System (INIS)

Gai, Wei.

1989-01-01

In this paper we propose a multi-stage wake field acceleration scheme to overcome the low transformer ratio problem and still provide high accelerating gradients. The idea is very simple. We use a train of several electron bunches from a linear accelerator (main linac) with well defined separations between the bunches (tens of ns) to drive wake field devices. Here we have made the assumption that the wake field devices are available, whether plasma, iris-loaded metallic or dielectric wake field structures. 10 refs

Basic Energy Sciences Program Update

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-01-04

The U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences (BES) supports fundamental research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels to provide the foundations for new energy technologies and to support DOE missions in energy, environment, and national security. The research disciplines covered by BES—condensed matter and materials physics, chemistry, geosciences, and aspects of physical biosciences— are those that discover new materials and design new chemical processes. These disciplines touch virtually every aspect of energy resources, production, conversion, transmission, storage, efficiency, and waste mitigation. BES also plans, constructs, and operates world-class scientific user facilities that provide outstanding capabilities for imaging and spectroscopy, characterizing materials of all kinds ranging from hard metals to fragile biological samples, and studying the chemical transformation of matter. These facilities are used to correlate the microscopic structure of materials with their macroscopic properties and to study chemical processes. Such experiments provide critical insights to electronic, atomic, and molecular configurations, often at ultrasmall length and ultrafast time scales.

Wake modeling and simulation

DEFF Research Database (Denmark)

Larsen, Gunner Chr.; Madsen Aagaard, Helge; Larsen, Torben J.

We present a consistent, physically based theory for the wake meandering phenomenon, which we consider of crucial importance for the overall description of wind turbine loadings in wind farms. In its present version the model is confined to single wake situations. The model philosophy does, howev...... methodology has been implemented in the aeroelastic code HAWC2, and example simulations of wake situations, from the small Tjæreborg wind farm, have been performed showing satisfactory agreement between predictions and measurements...

Utilization and acceptance of virtual patients in veterinary basic sciences – the vetVIP-project

Directory of Open Access Journals (Sweden)

Kleinsorgen, Christin

2017-05-01

Full Text Available Context: In medical and veterinary medical education the use of problem-based and cased-based learning has steadily increased over time. At veterinary faculties, this development has mainly been evident in the clinical phase of the veterinary education. Therefore, a consortium of teachers of biochemistry and physiology together with technical and didactical experts launched the EU-funded project “vetVIP”, to create and implement veterinary virtual patients and problems for basic science instruction. In this study the implementation and utilization of virtual patients occurred at the veterinary faculties in Budapest, Hannover and Lublin.Methods: This report describes the investigation of the utilization and acceptance of students studying veterinary basic sciences using optional online learning material concurrently to regular biochemistry and physiology didactic instruction. The reaction of students towards this offer of clinical case-based learning in basic sciences was analysed using quantitative and qualitative data. Quantitative data were collected automatically within the chosen software-system CASUS as user-log-files. Responses regarding the quality of the virtual patients were obtained using an online questionnaire. Furthermore, subjective evaluation by authors was performed using a focus group discussion and an online questionnaire.Results: Implementation as well as usage and acceptance varied between the three participating locations. High approval was documented in Hannover and Lublin based upon the high proportion of voluntary students (>70% using optional virtual patients. However, in Budapest the participation rate was below 1%. Due to utilization, students seem to prefer virtual patients and problems created in their native language and developed at their own university. In addition, the statement that assessment drives learning was supported by the observation that peak utilization was just prior to summative examinations

The development of sleep-wake rhythms and the search for elemental circuits in the infant brain.

Science.gov (United States)

Blumberg, Mark S; Gall, Andrew J; Todd, William D

2014-06-01

Despite the predominance of sleep in early infancy, developmental science has yet to play a major role in shaping concepts and theories about sleep and its associated ultradian and circadian rhythms. Here we argue that developmental analyses help us to elucidate the relative contributions of the brainstem and forebrain to sleep-wake control and to dissect the neural components of sleep-wake rhythms. Developmental analysis also makes it clear that sleep-wake processes in infants are the foundation for those of adults. For example, the infant brainstem alone contains a fundamental sleep-wake circuit that is sufficient to produce transitions among wakefulness, quiet sleep, and active sleep. In addition, consistent with the requirements of a "flip-flop" model of sleep-wake processes, this brainstem circuit supports rapid transitions between states. Later in development, strengthening bidirectional interactions between the brainstem and forebrain contribute to the consolidation of sleep and wake bouts, the elaboration of sleep homeostatic processes, and the emergence of diurnal or nocturnal circadian rhythms. The developmental perspective promoted here critically constrains theories of sleep-wake control and provides a needed framework for the creation of fully realized computational models. Finally, with a better understanding of how this system is constructed developmentally, we will gain insight into the processes that govern its disintegration due to aging and disease.

A case-based, small-group cooperative learning course in preclinical veterinary science aimed at bridging basic science and clinical literacy.

Science.gov (United States)

Schoeman, J P; van Schoor, M; van der Merwe, L L; Meintjes, R A

2009-03-01

In 1999 a dedicated problem-based learning course was introduced into the lecture-based preclinical veterinary curriculum of the University of Pretoria. The Introduction to Clinical Studies Course combines traditional lectures, practical sessions, student self-learning and guided tutorials. The self-directed component of the course utilises case-based, small-group cooperative learning as an educational vehicle to link basic science with clinical medicine. The aim of this article is to describe the objectives and structure of the course and to report the results of the assessment of the students' perceptions on some aspects of the course. Students reacted very positively to the ability of the course to equip them with problem-solving skills. Students indicated positive perceptions about the workload of the course. There were, however, significantly lower scores for the clarity of the course objectives. Although the study guide for the course is very comprehensive, the practice regarding the objectives is still uncertain. It is imperative to set clear objectives in non-traditional, student-centred courses. The objectives have to be explained at the outset and reiterated throughout the course. Tutors should also communicate the rationale behind problem-based learning as a pedagogical method to the students. Further research is needed to verify the effectiveness of this course in bridging the gap between basic science and clinical literacy in veterinary science. Ongoing feedback and assessment of the management and content are important to refine this model for integrating basic science with clinical literacy.

Thinking science with thinking machines: The multiple realities of basic and applied knowledge in a research border zone.

Science.gov (United States)

Hoffman, Steve G

2015-04-01

Some scholars dismiss the distinction between basic and applied science as passé, yet substantive assumptions about this boundary remain obdurate in research policy, popular rhetoric, the sociology and philosophy of science, and, indeed, at the level of bench practice. In this article, I draw on a multiple ontology framework to provide a more stable affirmation of a constructivist position in science and technology studies that cannot be reduced to a matter of competing perspectives on a single reality. The analysis is grounded in ethnographic research in the border zone of Artificial Intelligence science. I translate in-situ moments in which members of neighboring but differently situated labs engage in three distinct repertoires that render the reality of basic and applied science: partitioning, flipping, and collapsing. While the essences of scientific objects are nowhere to be found, the boundary between basic and applied is neither illusion nor mere propaganda. Instead, distinctions among scientific knowledge are made real as a matter of course.

Radiation chemistry: basic, strategic or tactical science?

International Nuclear Information System (INIS)

Wardman, Peter

1989-01-01

The work of Weiss in the 1930s, particularly with Haber, has only recently been recognized to have implications in biology and medicine. Similarly, research in radiation chemistry and the application of the pulse radiolysis technique, for example, have implications far beyond traditional radiation chemistry. Some examples of such research are discussed against a background of categorization into 'basic', 'strategic' or 'tactical' science. Examples discussed include redox properties of free radicals, and the identification and characterization of nitro radicals as intermediates in drug metabolism. Radical reactions often take place in multicomponent systems, and the techniques of radiation chemistry can be used to probe, for example, events occurring at interfaces in micelles. Industrial processes involving radiation are attracting investment, particularly in Japan. (author)

Dynamic Hybrid Simulation of the Lunar Wake During ARTEMIS Crossing

Science.gov (United States)

Wiehle, S.; Plaschke, F.; Angelopoulos, V.; Auster, H.; Glassmeier, K.; Kriegel, H.; Motschmann, U. M.; Mueller, J.

2010-12-01

The interaction of the highly dynamic solar wind with the Moon is simulated with the A.I.K.E.F. (Adaptive Ion Kinetic Electron Fluid) code for the ARTEMIS P1 flyby on February 13, 2010. The A.I.K.E.F. hybrid plasma simulation code is the improved version of the Braunschweig code. It is able to automatically increase simulation grid resolution in areas of interest during runtime, which greatly increases resolution as well as performance. As the Moon has no intrinsic magnetic field and no ionosphere, the solar wind particles are absorbed at its surface, resulting in the formation of the lunar wake at the nightside. The solar wind magnetic field is basically convected through the Moon and the wake is slowly filled up with solar wind particles. However, this interaction is strongly influenced by the highly dynamic solar wind during the flyby. This is considered by a dynamic variation of the upstream conditions in the simulation using OMNI solar wind measurement data. By this method, a very good agreement between simulation and observations is achieved. The simulations show that the stationary structure of the lunar wake constitutes a tableau vivant in space representing the well-known Friedrichs diagram for MHD waves.

Basic Science Research and the Protection of Human Research Participants

Science.gov (United States)

Eiseman, Elisa

2001-03-01

Technological advances in basic biological research have been instrumental in recent biomedical discoveries, such as in the understanding and treatment of cancer, HIV/AIDS, and heart disease. However, many of these advances also raise several new ethical challenges. For example, genetic research may pose no physical risk beyond that of obtaining the initial blood sample, yet it can pose significant psychological and economic risks to research participants, such as stigmatization, discrimination in insurance and employment, invasion of privacy, or breach of confidentiality. These harms may occur even when investigators do not directly interact with the person whose DNA they are studying. Moreover, this type of basic research also raises broader questions, such as what is the definition of a human subject, and what kinds of expertise do Institutional Review Boards (IRBs) need to review the increasingly diverse types of research made possible by these advances in technology. The National Bioethics Advisory Commission (NBAC), a presidentially appointed federal advisory committee, has addressed these and other ethical, scientific and policy issues that arise in basic science research involving human participants. Two of its six reports, in particular, have proposed recommendations in this regard. "Research Involving Human Biological Materials: Ethical and Policy Guidance" addresses the basic research use of human tissues, cells and DNA and the protection of human participants in this type of research. In "Ethical and Policy Issues in the Oversight of Human Research" NBAC proposes a definition of research involving human participants that would apply to all scientific disciplines, including physical, biological, and social sciences, as well as the humanities and related professions, such as business and law. Both of these reports make it clear that the protection of research participants is key to conducting ethically sound research. By ensuring that all participants in

Wake modelling combining mesoscale and microscale models

DEFF Research Database (Denmark)

Badger, Jake; Volker, Patrick; Prospathospoulos, J.

2013-01-01

In this paper the basis for introducing thrust information from microscale wake models into mesocale model wake parameterizations will be described. A classification system for the different types of mesoscale wake parameterizations is suggested and outlined. Four different mesoscale wake paramet...

The United Nations Basic Space Science Initiative (UNBSSI): A Historical Introduction

Science.gov (United States)

Haubold, H. J.

2006-11-01

Pursuant to recommendations of the Third United Nations Conference on the Exploration and Peaceful Uses of Outer Space (UNISPACE III) and deliberations of the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS), annual UN/European Space Agency workshops on basic space science have been held around the world since 1991. These workshops contributed to the development of astrophysics and space science, particularly in developing nations. Following a process of prioritization, the workshops identified the following elements as particularly important for international cooperation in the field: (i) operation of astronomical telescope facilities implementing TRIPOD, (ii) virtual observatories, (iii) astrophysical data systems, (iv) con-current design capabilities for the development of international space missions, and (v) theoretical astrophysics such as applications of non-extensive statistical mechanics. Beginning in 2005, the workshops are focusing on preparations for the International Heliophysical Year 2007 (IHY2007). The workshops continue to facilitate the establishment of astronomical telescope facilities as pursued by Japan and the development of low-cost, ground-based, world- wide instrument arrays as led by the IHY secretariat. Wamsteker, W., Albrecht, R. and Haubold, H.J.: Developing Basic Space Science World-Wide: A Decade of UN/ESA Workshops: Kluwer Academic Publishers, Dordrecht 2004. http://ihy2007.org http://www.unoosa.org/oosa/en/SAP/bss/ihy2007/index.html http://www.cbpf.br/GrupPesq/StatisticalPhys/biblio.htm

The Neuropsychoanalytic Approach: Using Neuroscience as the Basic Science of Psychoanalysis

Science.gov (United States)

Johnson, Brian; Flores Mosri, Daniela

2016-01-01

Neuroscience was the basic science behind Freud's psychoanalytic theory and technique. He worked as a neurologist for 20 years before being aware that a new approach to understand complex diseases, namely the hysterias, was needed. Solms coined the term neuropsychoanalysis to affirm that neuroscience still belongs in psychoanalysis. The neuropsychoanalytic field has continued Freud's original ideas as stated in 1895. Developments in psychoanalysis that have been created or revised by the neuropsychoanalysis movement include pain/relatedness/opioids, drive, structural model, dreams, cathexis, and dynamic unconscious. Neuroscience has contributed to the development of new psychoanalytic theory, such as Bazan's (2011) description of anxiety driven by unconscious intentions or “phantoms.” Results of adopting the “dual aspect monism” approach of idiographic psychoanalytic clinical observation combined with nomothetic investigation of related human phenomena include clarification and revision of theory, restoration of the scientific base of psychoanalysis, and improvement of clinical treatments. By imbricating psychoanalytic thinking with neuroscience, psychoanalysts are also positioned to make contributions to neuroscience research. Freud's original Project for a Scientific Psychology/Psychology for Neurologists can be carried forward in a way that moves psychoanalysis into the twenty-first century as a core contemporary science (Kandel, 1999). Neuroscience as the basic science of psychoanalysis both improves the field, and enhances its scientific and cultural status. PMID:27790160

Aligning library instruction with the needs of basic sciences graduate students: a case study.

Science.gov (United States)

O'Malley, Donna; Delwiche, Frances A

2012-10-01

How can an existing library instruction program be reconfigured to reach basic sciences graduate students and other patrons missed by curriculum-based instruction? The setting is an academic health sciences library that serves both the university and its affiliated teaching hospital. The existing program was redesigned to incorporate a series of seven workshops that encompassed the range of information literacy skills that graduate students in the basic sciences need. In developing the new model, the teaching librarians made changes in pedagogy, technology, marketing, and assessment strategies. Total attendance at the sessions increased substantially in the first 2 years of the new model, increasing from an average of 20 per semester to an average of 124. Survey results provided insight about what patrons wanted to learn and how best to teach it. Modifying the program's content and structure resulted in a program that appealed to the target audience.

Unsteady wake of a rotating tire

Science.gov (United States)

Lombard, Jean-Eloi; Moxey, Dave; Xu, Hui; Sherwin, Spencer; Sherwin Lab Team

2015-11-01

For open wheel race-cars, such as IndyCar and Formula One, the wheels are responsible for 40% of the total drag. For road cars drag associated to the wheels and under-carriage can represent 60% of total drag at highway cruise speeds. Experimental observations have reported two or three pairs of counter rotating vortices, the relative importance of which still remains an open question, that interact to form a complex wake. Traditional RANS based methods are typically not well equipped to deal with such highly unsteady flows which motivates research into more physical, unsteady models. Leveraging a high-fidelity spectral/hp element based method a Large Eddy Simulation is performed to give further insight into unsteady characteristics of the wake. In particular the unsteady nature of both the jetting and top vortex pair is reported as well as the time and length scales associated with the vortex core trajectories. Correlation with experimentally obtained particle image velocimetry is presented. The authors acknowledge support from the United Kingdom Turbulence Consortium (UKTC) as well as from the Engineering and Physical Sciences Research Council (EPSRC) for access to ARCHER UK National Supercomputing Service.

Key steps for integrating a basic science throughout a medical school curriculum using an e-learning approach.

Science.gov (United States)

Dubois, Eline Agnès; Franson, Kari Lanette

2009-09-01

Basic sciences can be integrated into the medical school curriculum via e-learning. The process of integrating a basic science in this manner resembles a curricular change. The change usually begins with an idea for using e-learning to teach a basic science and establishing the need for the innovation. In the planning phase, learning outcomes are formulated and a prototype of the program is developed based on the desired requirements. A realistic concept is formed after considering the limitations of the current institute. Next, a project team is assembled to develop the program and plan its integration. Incorporation of the e-learning program is facilitated by a well-developed and communicated integration plan. Various course coordinators are contacted to determine content of the e-learning program as well as establish assessment. Linking the e-learning program to existing course activities and thereby applying the basic science into the clinical context enhances the degree of integration. The success of the integration is demonstrated by a positive assessment of the program including favourable cost-benefit analysis and improved student performance. Lastly, when the program becomes institutionalised, continuously updating content and technology (when appropriate), and evaluating the integration contribute to the prolonged survival of the e-learning program.

Flow Characteristics of Ground Vehicle Wake and Its Response to Flow Control

Science.gov (United States)

Sellappan, Prabu; McNally, Jonathan; Alvi, Farrukh

2017-11-01

Air pollution, fuel shortages, and cost savings are some of the many incentives for improving the aerodynamics of vehicles. Reducing wake-induced aerodynamic drag, which is dependent on flow topology, on modern passenger vehicles is important for improving fuel consumption rates which directly affect the environment. In this research, an active flow control technique is applied on a generic ground vehicle, a 25°Ahmed model, to investigate its effect on the flow topology in the near-wake. The flow field of this canonical bluff body is extremely rich, with complex and unsteady flow features such as trailing wake vortices and c-pillar vortices. The spatio-temporal response of these flow features to the application of steady microjet actuators is investigated. The responses are characterized independently through time-resolved and volumetric velocity field measurements. The accuracy and cost of volumetric measurements in this complex flow field through Stereoscopic- and Tomographic- Particle Image Velocimetry (PIV) will also be commented upon. National Science Foundation PIRE Program.

The wake field acceleration using a cavity of elliptical cross section, part 1: WELL

International Nuclear Information System (INIS)

Chin, Yongho.

1983-11-01

A computer code WELL is developed for the calculation of the wake fields in a cavity of elliptical cross section. The method is basically an extention of that of BCI to the 3-dimensional computation, i.e., Maxwell's equations are solved in the time domain with boundary conditions. Open boundary conditions are used so as to simulate infinitely long beam pipes. Good agreements within a few percents are shown between the results of the computation by WELL and BCI in a cylindrically symmetrical structure. An example of computation in an elliptical structure gives a reasonable result and points out that the deflection of particles by the transverse wake field is severe. (author)

A case-based, small-group cooperative learning course in preclinical veterinary science aimed at bridging basic science and clinical literacy

Directory of Open Access Journals (Sweden)

J.P. Schoeman

2009-05-01

Full Text Available In 1999 a dedicated problem-based learning course was introduced into the lecture-based preclinical veterinary curriculum of the University of Pretoria. The Introduction to Clinical Studies Course combines traditional lectures, practical sessions, student self-learning and guided tutorials. The self-directed component of the course utilises case-based, small group cooperative learning as an educational vehicle to link basic science with clinical medicine. The aim of this article is to describe the objectives and structure of the course and to report the results of the assessment of the students' perceptions on some aspects of the course. Students reacted very positively to the ability of the course to equip them with problem-solving skills. Students indicated positive perceptions about the workload of the course. There were, however, significantly lower scores for the clarity of the course objectives. Although the study guide for the course is very comprehensive, the practice regarding the objectives is still uncertain. It is imperative to set clear objectives in non-traditional, student-centred courses. The objectives have to be explained at the outset and reiterated throughout the course. Tutors should also communicate the rationale behind problem based learning as a pedagogical method to the students. Further research is needed to verify the effectiveness of this course in bridging the gap between basic science and clinical literacy in veterinary science. Ongoing feedback and assessment of the management and content are important to refine this model for integrating basic science with clinical literacy.

Wind farm array wake losses

Energy Technology Data Exchange (ETDEWEB)

Baker, R.W. [Impact Weather, Washougal, WA (United States); McCarthy, E.F. [Wind Economics & Technology, Inc., Martinez, CA (United States)

1997-12-31

A wind turbine wake study was conducted in the summer of 1987 at an Altamont Pass wind electric generating facility. The wind speed deficits, turbulence, and power deficits from an array consisting of several rows of wind turbines is discussed. A total of nine different test configurations were evaluated for a downwind spacing ranging from 7 rotor diameters (RD) to 34 RD and a cross wind spacing of 1.3 RD and 2.7 RD. Wake power deficits of 15% were measured at 16 RD and power losses of a few percent were even measurable at 27 RD for the closer cross wind spacing. For several rows of turbines separated by 7-9 RD the wake zones overlapped and formed compound wakes with higher velocity deficits. The wind speed and direction turbulence in the wake was much higher than the ambient turbulence. The results from this study are compared to the findings from other similar field measurements.

Wake fields in semiconductor plasmas

International Nuclear Information System (INIS)

Berezhiani, V.I.; Mahajan, S.M.

1994-05-01

It is shown that an intense short laser pulse propagating through a semiconductor plasma will generated longitudinal Langmuir waves in its wake. The measurable wake field can be used as a diagnostic to study nonlinear optical phenomena. For narrow gap semiconductors (for examples InSb) with Kane-type dispersion relation, the system can simulate, at currently available laser powers, the physics underlying wake-field accelerators. (author). 9 refs, 1 fig

Three-Phased Wake Vortex Decay

Science.gov (United States)

Proctor, Fred H.; Ahmad, Nashat N.; Switzer, George S.; LimonDuparcmeur, Fanny M.

2010-01-01

A detailed parametric study is conducted that examines vortex decay within turbulent and stratified atmospheres. The study uses a large eddy simulation model to simulate the out-of-ground effect behavior of wake vortices due to their interaction with atmospheric turbulence and thermal stratification. This paper presents results from a parametric investigation and suggests improvements for existing fast-time wake prediction models. This paper also describes a three-phased decay for wake vortices. The third phase is characterized by a relatively slow rate of circulation decay, and is associated with the ringvortex stage that occurs following vortex linking. The three-phased decay is most prevalent for wakes imbedded within environments having low-turbulence and near-neutral stratification.

Diffusion in building wakes

International Nuclear Information System (INIS)

Ramsdell, J.V.

1988-03-01

Straight-line Gaussian models adequately describe atmospheric diffusion for many applications. They have been modified for use in estimating diffusion in building wakes by adding terms that include projected building area and by redefining the diffusion coefficients so that the coefficients have minimum values that are related to building dimensions. In a recent study, Ramsdell reviewed the building-wake dispersion models used by the Nuclear Regulatory Commission (NRC) in its control room habitability assessments. The review included comparison of model estimates of centerline concentrations with concentrations observed in experiments at seven nuclear reactors. In general, the models are conservative in that they tend to predict concentrations that are greater than those actually observed. However, the models show little skill in accounting for variations in the observed concentrations. Subsequently, the experimental data and multiples linear regression techniques have been used to develop a new building wake diffusion model. This paper describes the new building wake model and compares it with other models. 8 refs., 2 figs

Wake effect in rocket observation

International Nuclear Information System (INIS)

Matsumoto, Haruya; Kaya, Nobuyuki; Yamanaka, Akira; Hayashi, Tomomasa

1975-01-01

The mechanism of the wake phenomena due to a probe and in rocket observation is discussed on the basis of experimental data. In the low energy electron measurement performed with the L-3H-5 rocket, the electron count rate changed synchronously with the rocket spin. This seems to be a wake effect. It is also conceivable that the probe itself generates the wake of ion beam. The latter problem is considered in the first part. Experiment was performed with laboratory plasma, in which a portion of the electron component of the probe current was counted with a CEM (a channel type multiplier). The change of probe voltage-count rate charactersitics due to the change of relative position of the ion source was observed. From the measured angular distributions of electron density and electron temperature around the probe, it is concluded that anisotropy exists around the probe, which seems to be a kinds of wake structure. In the second part, the wake effect due to a rocket is discussed on the basis of the measurement of leaking electrons with L-3H-5 rocket. Comparison between the theory of wake formation and the measured results is also shortly made in the final part. (Aoki, K.)

The rate of knowledge retention in basic sciences courses among dentistry students

Directory of Open Access Journals (Sweden)

S.S Mazloomi

2009-03-01

Full Text Available Background: Acquiring and recalling knowledge can be considered as the starting point of learning; so increasing  the acquisition  of knowledge and information  recall is one the most important goals of education.Objective: To determine the students'  information recall in the basic courses of histology, immunology, physiology, biochemistry,  head and neck anatomy,  and microbiology  in dentistry  school.Method:  In this descriptive  survey, 60 students who had passed their basis courses were studied. The tests  were  held  five semesters  following  the basic  courses,  and  were  like  those  they  had  passed previously.Results: The results revealed that information recall was the highest for the physiology course (z=0.72, while it was the lowest for anatomy (z=0.07. For the histology course, the lowest mean score was achieved by the students entered in the  year 1997, and the highest  by those  entered  in 1999. The relationship between the entry year  of the  students  and  their  information recall  is  statistically significant  (p<0.05.Discussant: The results showed that the teaching basic science courses such as physiology, anatomy, immunology, microbiology, and biochemistry should  accompany new  strategies in  teaching  and learning. One of these is the inclusion by the teachers of retrieval cues in any course so as to facilitate learning.Keywords:  knowledge retention,  basic sciences

Wake flow characteristics at high wind speed

DEFF Research Database (Denmark)

Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.

2016-01-01

Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated ...

Wake shed by an accelerating carangiform fish

Science.gov (United States)

Ting, Shang-Chieh; Yang, Jing-Tang

2008-11-01

We reveal an important fact that momentum change observed in the wake of an accelerating carangiform fish does not necessarily elucidate orientations of propulsive forces produced. An accelerating Crucian Carp (Carassius auratus) was found to shed a wake with net forward fluid momentum, which seemed drag-producing. Based on Newton's law, however, an accelerating fish is expected to shed a thrust wake with net rearward fluid momentum, rather than a drag wake. The unusual wake pattern observed is considered to be resulted primarily from the effect of pressure gradient created by accelerating movements of the fish. Ambient fluids tend to be sucked into low pressure zones behind an accelerating fish, resulting in forward orientations of jets recognizable in the wake. Accordingly, as to an accelerating fish, identifying force orientations from the wake requires considering also the effect of pressure gradient.

Basic Definitions and Concepts of Systems Approach, Mathematical Modeling and Information Technologies in Sports Science

Directory of Open Access Journals (Sweden)

А. Лопатьєв

2017-09-01

Full Text Available The objective is to systematize and adapt the basic definitions and concepts of the systems approach, mathematical modeling and information technologies to sports science. Materials and methods. The research has studied the availability of appropriate terms in shooting sports, which would meet the requirements of modern sports science. It has examined the compliance of the shooting sports training program for children and youth sports schools, the Olympic reserve specialized children and youth schools, schools of higher sports skills, and sports educational institutions with the modern requirements and principles. Research results. The paper suggests the basic definitions adapted to the requirements of technical sports and sports science. The research has thoroughly analyzed the shooting sports training program for children and youth sports schools, the Olympic reserve specialized children and youth schools, schools of higher sports skills, and sports educational institutions. The paper offers options to improve the training program in accordance with the modern tendencies of training athletes.  Conclusions. The research suggests to systematize and adapt the basic definitions and concepts of the systems approach, mathematical modeling and information technologies using the example of technical sports.

Disaster Relief and Emergency Medical Services Project (DREAMS TM): Clinical and Basic Science Projects

National Research Council Canada - National Science Library

Casscells, Ward

1999-01-01

DREAMS clinical and basic science projects complement the digital EMS effort by investigating the mechanisms of tissue injury in order to minimize the mortality and mortality of trauma and "natural...

Finnegans Wake & embodied cognition. A joycean reading

Directory of Open Access Journals (Sweden)

Simone Rebora

2014-06-01

Full Text Available This contribution proposes an interpretation of the language theory in Finnegans Wake, identifying its potential matches with the embodied cognition thesis. First, are revised critical texts about the relations between joycean writings, the sciences of the mind and the evolution of technology and informatics. Then, through the close analysis of four excerpt, are outlined the traits of joycean poetics closer to the recent acquisitions in the cognitive sciences. In particular: the bodily roots of the formation of language and the inexhaustible process of interpretation. The first convergence is detected in neurosciences, with reference to the recent proposals of Vittorio Gallese, about “embodiment of language comprehension.” The second convergence is identified in the studies on Artificial Life, referring to the writings of Christopher Langton and the Research Group of Los Alamos.

Multi-Model Ensemble Wake Vortex Prediction

Science.gov (United States)

Koerner, Stephan; Holzaepfel, Frank; Ahmad, Nash'at N.

2015-01-01

Several multi-model ensemble methods are investigated for predicting wake vortex transport and decay. This study is a joint effort between National Aeronautics and Space Administration and Deutsches Zentrum fuer Luft- und Raumfahrt to develop a multi-model ensemble capability using their wake models. An overview of different multi-model ensemble methods and their feasibility for wake applications is presented. The methods include Reliability Ensemble Averaging, Bayesian Model Averaging, and Monte Carlo Simulations. The methodologies are evaluated using data from wake vortex field experiments.

Orexin/Hypocretin and Organizing Principles for a Diversity of Wake-Promoting Neurons in the Brain.

Science.gov (United States)

Schöne, Cornelia; Burdakov, Denis

2017-01-01

An enigmatic feature of behavioural state control is the rich diversity of wake-promoting neural systems. This diversity has been rationalized as 'robustness via redundancy', wherein wakefulness control is not critically dependent on one type of neuron or molecule. Studies of the brain orexin/hypocretin system challenge this view by demonstrating that wakefulness control fails upon loss of this neurotransmitter system. Since orexin neurons signal arousal need, and excite other wake-promoting neurons, their actions illuminate nonredundant principles of arousal control. Here, we suggest such principles by reviewing the orexin system from a collective viewpoint of biology, physics and engineering. Orexin peptides excite other arousal-promoting neurons (noradrenaline, histamine, serotonin, acetylcholine neurons), either by activating mixed-cation conductances or by inhibiting potassium conductances. Ohm's law predicts that these opposite conductance changes will produce opposite effects on sensitivity of neuronal excitability to current inputs, thus enabling orexin to differentially control input-output gain of its target networks. Orexin neurons also produce other transmitters, including glutamate. When orexin cells fire, glutamate-mediated downstream excitation displays temporal decay, but orexin-mediated excitation escalates, as if orexin transmission enabled arousal controllers to compute a time integral of arousal need. Since the anatomical and functional architecture of the orexin system contains negative feedback loops (e.g. orexin ➔ histamine ➔ noradrenaline/serotonin-orexin), such computations may stabilize wakefulness via integral feedback, a basic engineering strategy for set point control in uncertain environments. Such dynamic behavioural control requires several distinct wake-promoting modules, which perform nonredundant transformations of arousal signals and are connected in feedback loops.

Evolution in health and medicine Sackler colloquium: Making evolutionary biology a basic science for medicine.

Science.gov (United States)

Nesse, Randolph M; Bergstrom, Carl T; Ellison, Peter T; Flier, Jeffrey S; Gluckman, Peter; Govindaraju, Diddahally R; Niethammer, Dietrich; Omenn, Gilbert S; Perlman, Robert L; Schwartz, Mark D; Thomas, Mark G; Stearns, Stephen C; Valle, David

2010-01-26

New applications of evolutionary biology in medicine are being discovered at an accelerating rate, but few physicians have sufficient educational background to use them fully. This article summarizes suggestions from several groups that have considered how evolutionary biology can be useful in medicine, what physicians should learn about it, and when and how they should learn it. Our general conclusion is that evolutionary biology is a crucial basic science for medicine. In addition to looking at established evolutionary methods and topics, such as population genetics and pathogen evolution, we highlight questions about why natural selection leaves bodies vulnerable to disease. Knowledge about evolution provides physicians with an integrative framework that links otherwise disparate bits of knowledge. It replaces the prevalent view of bodies as machines with a biological view of bodies shaped by evolutionary processes. Like other basic sciences, evolutionary biology needs to be taught both before and during medical school. Most introductory biology courses are insufficient to establish competency in evolutionary biology. Premedical students need evolution courses, possibly ones that emphasize medically relevant aspects. In medical school, evolutionary biology should be taught as one of the basic medical sciences. This will require a course that reviews basic principles and specific medical applications, followed by an integrated presentation of evolutionary aspects that apply to each disease and organ system. Evolutionary biology is not just another topic vying for inclusion in the curriculum; it is an essential foundation for a biological understanding of health and disease.

Potential load reductions on megawatt turbines exposed to wakes using individual-pitch wake compensator and trailing-edge flaps

DEFF Research Database (Denmark)

Markou, Helen; Andersen, Peter Bjørn; Larsen, Gunner Chr.

2011-01-01

that typically focus on either load or power prediction. As a consequence, the wake affected inflow field generated by the DWM formulation opens for control strategies for the individual turbine. Two different control approaches for load reduction on the individual turbines are implemented in the multi-body aero-servo-elastic...... tool HAWC2, developed at Risø-DTU in Denmark, and their potential load reduction capabilities compared: (1) full-blade ‘individual-pitch controllers’ acting as wake compensators and (2) controllers using trailing-edge flaps. Information on the wake inflow conditions, induced by upstream turbines...... for the loading conditions of the individual turbines in the farm. The dynamic wake meandering model (DWM) is believed to capture the essential physics of the wake problem, and thus, both load and production aspects can be predicted, which is contrary to the traditional engineering wake prediction methods...

Pharmaceutical applications of cyclodextrins: basic science and product development.

Science.gov (United States)

Loftsson, Thorsteinn; Brewster, Marcus E

2010-11-01

Drug pipelines are becoming increasingly difficult to formulate. This is punctuated by both retrospective and prospective analyses that show that while 40% of currently marketed drugs are poorly soluble based on the definition of the biopharmaceutical classification system (BCS), about 90% of drugs in development can be characterized as poorly soluble. Although a number of techniques have been suggested for increasing oral bioavailability and for enabling parenteral formulations, cyclodextrins have emerged as a productive approach. This short review is intended to provide both some basic science information as well as data on the ability to develop drugs in cyclodextrin-containing formulations. There are currently a number of marketed products that make use of these functional solubilizing excipients and new product introduction continues to demonstrate their high added value. The ability to predict whether cyclodextrins will be of benefit in creating a dosage form for a particular drug candidate requires a good working knowledge of the properties of cyclodextrins, their mechanism of solubilization and factors that contribute to, or detract from, the biopharmaceutical characteristics of the formed complexes. We provide basic science information as well as data on the development of drugs in cyclodextrin-containing formulations. Cyclodextrins have emerged as an important tool in the formulator's armamentarium to improve apparent solubility and dissolution rate for poorly water-soluble drug candidates. The continued interest and productivity of these materials bode well for future application and their currency as excipients in research, development and drug product marketing. © 2010 The Authors. Journal compilation © 2010 Royal Pharmaceutical Society of Great Britain.

Geoengineering: Basic science and ongoing research efforts in China

Directory of Open Access Journals (Sweden)

Long Cao

2015-09-01

Full Text Available Geoengineering (also called climate engineering, which refers to large-scale intervention in the Earth's climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas of climate research as a potential option for tackling global warming. Here, we provide an overview of the scientific background and research progress of proposed geoengineering schemes. Geoengineering can be broadly divided into two categories: solar geoengineering (also called solar radiation management, or SRM, which aims to reflect more sunlight to space, and carbon dioxide removal (CDR, which aims to reduce the CO2 content in the atmosphere. First, we review different proposed geoengineering methods involved in the solar radiation management and carbon dioxide removal schemes. Then, we discuss the fundamental science underlying the climate response to the carbon dioxide removal and solar radiation management schemes. We focus on two basic issues: 1 climate response to the reduction in solar irradiance and 2 climate response to the reduction in atmospheric CO2. Next, we introduce an ongoing geoengineering research project in China that is supported by National Key Basic Research Program. This research project, being the first coordinated geoengineering research program in China, will systematically investigate the physical mechanisms, climate impacts, and risk and governance of a few targeted geoengineering schemes. It is expected that this research program will help us gain a deep understanding of the physical science underlying geoengineering schemes and the impacts of geoengineering on global climate, in particular, on the Asia monsoon region.

Linearised CFD models for wakes

Energy Technology Data Exchange (ETDEWEB)

Ott, S.; Berg, J.; Nielsen, Morten

2011-12-15

This report describes the development of a fast and reasonably accurate model for the prediction of energy production in offshore wind farms taking wake effects into account. The model has been implemented as a windows application called Fuga which can run in batch mode or as a graphical user interface. Fuga is briefly described. The model is based on a linearization technique which is described in some detail, and linearized, governing equations are derived and written in a standard form based on a mixed-spectral formulation. A new solution method is used to solve the equations which involves intensive use of look-up tables for storage of intermediate results. Due to the linearity of the model, multiple wakes from many turbines can be constructed from the wake of a single, solitary turbine. These are in turn constructed from Fourier components by a fast Fourier integral transform of results derived from generic look-up tables. Three different models, based on three different closures, are examined: 1) the 'simple closure' using an unperturbed eddy viscosity kucentre dotz. 2) the mixing length closure. 3) the E-epsilon closure. Model results are evaluated against offshore wind farm production data from Horns Rev I and the Nysted wind farm, and a comparison with direct wake measurements in an onshore turbine (Nibe B) is also made. A very satisfactory agreement with data is found for the simple closure. The exception is the near wake, just behind the rotor, where all three linearized models fail. The mixing length closure underestimates wake effects in all cases. The E-epsilon closure overestimates wake losses in the offshore farms while it predicts a too shallow and too wide the wake in the onshore case. The simple closure performs distinctly better than the other two. Wind speed data from the the Horns rev met masts are used to further validate Fuga results with the 'simple' closure. Finally, Roedsand 1 and 2 are used as an example to illustrate

Coupled wake boundary layer model of windfarms

Science.gov (United States)

Stevens, Richard; Gayme, Dennice; Meneveau, Charles

2014-11-01

We present a coupled wake boundary layer (CWBL) model that describes the distribution of the power output in a windfarm. The model couples the traditional, industry-standard wake expansion/superposition approach with a top-down model for the overall windfarm boundary layer structure. Wake models capture the effect of turbine positioning, while the top-down approach represents the interaction between the windturbine wakes and the atmospheric boundary layer. Each portion of the CWBL model requires specification of a parameter that is unknown a-priori. The wake model requires the wake expansion rate, whereas the top-down model requires the effective spanwise turbine spacing within which the model's momentum balance is relevant. The wake expansion rate is obtained by matching the mean velocity at the turbine from both approaches, while the effective spanwise turbine spacing is determined from the wake model. Coupling of the constitutive components of the CWBL model is achieved by iterating these parameters until convergence is reached. We show that the CWBL model predictions compare more favorably with large eddy simulation results than those made with either the wake or top-down model in isolation and that the model can be applied successfully to the Horns Rev and Nysted windfarms. The `Fellowships for Young Energy Scientists' (YES!) of the Foundation for Fundamental Research on Matter supported by NWO, and NSF Grant #1243482.

Analysis of a high brightness photo electron beam with self field and wake field effects

International Nuclear Information System (INIS)

Parsa, Z.

1991-01-01

High brightness sources are the basic ingredients in the new accelerator developments such as Free-Electron Laser experiments. The effects of the interactions between the highly charged particles and the fields in the accelerating structure, e.g. R.F., Space charge and Wake fields can be detrimental to the beam and the experiments. We present and discuss the formulation used, some simulation and results for the Brookhaven National Laboratory high brightness beam that illustrates effects of the accelerating field, space charge forces (e.g. due to self field of the bunch), and the wake field (e.g. arising from the interaction of the cavity surface and the self field of the bunch)

The Divergent Thinking of Basic Skills of Sciences Process Skills of Life Aspects on Natural Sciences Subject in Indonesian Elementary School Students

Science.gov (United States)

Subali, Bambang; Paidi; Mariyam, Siti

2016-01-01

This research aims at measuring the divergent thinking of basic skills of science process skills (SPS) of life aspects in Natural Sciences subjects on Elementary School. The test instruments used in this research have been standardized through the development of instruments. In this case, the tests were tried out to 3070 students. The results of…

Numerical Analysis of the Unsteady Propeller Performance in the Ship Wake Modified By Different Wake Improvement Devices

Directory of Open Access Journals (Sweden)

Bugalski Tomasz

2014-10-01

Full Text Available The paper presents the summary of results of the numerical analysis of the unsteady propeller performance in the non-uniform ship wake modified by the different wake improvement devices. This analysis is performed using the lifting surface program DUNCAN for unsteady propeller analysis. Te object of the analysis is a 7000 ton chemical tanker, for which four different types of the wake improvement devices have been designed: two vortex generators, a pre-swirl stator, and a boundary layer alignment device. These produced five different cases of the ship wake structure: the original hull and hull equipped alternatively with four wake improvement devices. Two different propellers were analyzed in these five wake fields, one being the original reference propeller P0 and the other - a specially designed, optimized propeller P3. Te analyzed parameters were the pictures of unsteady cavitation on propeller blades, harmonics of pressure pulses generated by the cavitating propellers in the selected points and the fluctuating bearing forces on the propeller shaft. Some of the calculated cavitation phenomena were confronted with the experimental. Te objective of the calculations was to demonstrate the differences in the calculated unsteady propeller performance resulting from the application of different wake improvement devices. Te analysis and discussion of the results, together with the appropriate conclusions, are included in the paper.

Probes, Moons, and Kinetic Plasma Wakes

Science.gov (United States)

Hutchinson, I. H.; Malaspina, D.; Zhou, C.

2017-10-01

Nonmagnetic objects as varied as probes in tokamaks or moons in space give rise to flowing plasma wakes in which strong distortions of the ion and electron velocity distributions cause electrostatic instabilities. Non-linear phenomena such as electron holes are then produced. Historic probe theory largely ignores the resulting unstable character of the wake, but since we can now simulate computationally the non-linear wake phenomena, a timely challenge is to reassess the influence of these instabilities both on probe measurements and on the wakes themselves. Because the electron instability wavelengths are very short (typically a few Debye-lengths), controlled laboratory experiments face serious challenges in diagnosing them. That is one reason why they have long been neglected as an influence in probe interpretation. Space-craft plasma observations, by contrast, easily obtain sub-Debye-length resolution, but have difficulty with larger-scale reconstruction of the plasma spatial variation. In addition to surveying our developing understanding of wakes in magnetized plasmas, ongoing analysis of Artemis data concerning electron holes observed in the solar-wind lunar wake will be featured. Work partially supported by NASA Grant NNX16AG82G.

Indirect methods for wake potential integration

International Nuclear Information System (INIS)

Zagorodnov, I.

2006-05-01

The development of the modern accelerator and free-electron laser projects requires to consider wake fields of very short bunches in arbitrary three dimensional structures. To obtain the wake numerically by direct integration is difficult, since it takes a long time for the scattered fields to catch up to the bunch. On the other hand no general algorithm for indirect wake field integration is available in the literature so far. In this paper we review the know indirect methods to compute wake potentials in rotationally symmetric and cavity-like three dimensional structures. For arbitrary three dimensional geometries we introduce several new techniques and test them numerically. (Orig.)

Clinical Practice Guideline for the Treatment of Intrinsic Circadian Rhythm Sleep-Wake Disorders: Advanced Sleep-Wake Phase Disorder (ASWPD), Delayed Sleep-Wake Phase Disorder (DSWPD), Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD), and Irregular Sleep-Wake Rhythm Disorder (ISWRD). An Update for 2015

Science.gov (United States)

Auger, R. Robert; Burgess, Helen J.; Emens, Jonathan S.; Deriy, Ludmila V.; Thomas, Sherene M.; Sharkey, Katherine M.

2015-01-01

A systematic literature review and meta-analyses (where appropriate) were performed and the GRADE approach was used to update the previous American Academy of Sleep Medicine Practice Parameters on the treatment of intrinsic circadian rhythm sleep-wake disorders. Available data allowed for positive endorsement (at a second-tier degree of confidence) of strategically timed melatonin (for the treatment of DSWPD, blind adults with N24SWD, and children/ adolescents with ISWRD and comorbid neurological disorders), and light therapy with or without accompanying behavioral interventions (adults with ASWPD, children/adolescents with DSWPD, and elderly with dementia). Recommendations against the use of melatonin and discrete sleep-promoting medications are provided for demented elderly patients, at a second- and first-tier degree of confidence, respectively. No recommendations were provided for remaining treatments/ populations, due to either insufficient or absent data. Areas where further research is needed are discussed. Citation: Auger RR, Burgess HJ, Emens JS, Deriy LV, Thomas SM, Sharkey KM. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders: advanced sleep-wake phase disorder (ASWPD), delayed sleep-wake phase disorder (DSWPD), non-24-hour sleep-wake rhythm disorder (N24SWD), and irregular sleep-wake rhythm disorder (ISWRD). An update for 2015. J Clin Sleep Med 2015;11(10):1199–1236. PMID:26414986

Performance and wake conditions of a rotor located in the wake of an obstacle

Science.gov (United States)

Naumov, I. V.; Kabardin, I. K.; Mikkelsen, R. F.; Okulov, V. L.; Sørensen, J. N.

2016-09-01

Obstacles like forests, ridges and hills can strongly affect the velocity profile in front of a wind turbine rotor. The present work aims at quantifying the influence of nearby located obstacles on the performance and wake characteristics of a downstream located wind turbine. Here the influence of an obstacle in the form of a cylindrical disk was investigated experimentally in a water flume. A model of a three-bladed rotor, designed using Glauert's optimum theory at a tip speed ratio λ = 5, was placed in the wake of a disk with a diameter close to the one of the rotor. The distance from the disk to the rotor was changed from 4 to 8 rotor diameters, with the vertical distance from the rotor axis varied 0.5 and 1 rotor diameters. The associated turbulent intensity of the incoming flow to the rotor changed 3 to '6% due to the influence of the disk wake. In the experiment, thrust characteristics and associated pulsations as a function of the incoming flow structures were measured by strain gauges. The flow condition in front of the rotor was measured with high temporal accuracy using LDA and power coefficients were determine as function of tip speed ratio for different obstacle positions. Furthermore, PIV measurements were carried out to study the development of the mean velocity deficit profiles of the wake behind the wind turbine model under the influence of the wake generated by the obstacle. By use of regression techniques to fit the velocity profiles it was possible to determine velocity deficits and estimate length scales of the wake attenuation.

Endoplasmic reticulum stress in wake-active neurons progresses with aging.

Science.gov (United States)

Naidoo, Nirinjini; Zhu, Jingxu; Zhu, Yan; Fenik, Polina; Lian, Jie; Galante, Ray; Veasey, Sigrid

2011-08-01

Fragmentation of wakefulness and sleep are expected outcomes of advanced aging. We hypothesize that wake neurons develop endoplasmic reticulum dyshomeostasis with aging, in parallel with impaired wakefulness. In this series of experiments, we sought to more fully characterize age-related changes in wakefulness and then, in relevant wake neuronal populations, explore functionality and endoplasmic reticulum homeostasis. We report that old mice show greater sleep/wake transitions in the active period with markedly shortened wake periods, shortened latencies to sleep, and less wake time in the subjective day in response to a novel social encounter. Consistent with sleep/wake instability and reduced social encounter wakefulness, orexinergic and noradrenergic wake neurons in aged mice show reduced c-fos response to wakefulness and endoplasmic reticulum dyshomeostasis with increased nuclear translocation of CHOP and GADD34. We have identified an age-related unfolded protein response injury to and dysfunction of wake neurons. It is anticipated that these changes contribute to sleep/wake fragmentation and cognitive impairment in aging. © 2011 The Authors. Aging Cell © 2011 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

The basic science of dermal fillers: past and present Part I: background and mechanisms of action.

Science.gov (United States)

Gilbert, Erin; Hui, Andrea; Waldorf, Heidi A

2012-09-01

Dermal fillers have provided a safe and effective means for aesthetic soft tissue augmentation, and have experienced a dramatic increase in popularity during the past 10 years. Much focus has been placed upon filler technique and patient outcomes. However, there is a relative lack of literature reviewing the basic science of dermal fillers, which is vital to a physician's understanding of how each product behaves in vivo. Part I of this article reviews the basic science and evolution of both historical and contemporary dermal fillers; Part II examines their adverse effects. We endeavor to provide the physician with a practical approach to choosing products that maximize both aesthetic outcome and safety.

A report of the Basic Energy Sciences Advisory Committee: 1992 review of the Basic Energy Sciences Program of the Department of Energy

International Nuclear Information System (INIS)

1993-09-01

The general quality of BES research at each of the 4 laboratories is high. Diversity of management at the different laboratories is beneficial as long as the primary BES mission and goals are clearly identified and effectively pursued. External sources of personnel should be encouraged. DOE has been designing a new high flux research reactor, the Advanced Neutron Source, to replace DOE's two aging research reactors; BESAC conducted a panel evaluation of neutron sources for the future. The two new light sources, Advanced Light Source and Advanced Photon source will come on line well before all of their beamline instrumentation can be funded, developed, and installed. Appointment of a permanent director and deputy for OBES would enhance OBES effectiveness in budget planning and intra-DOE program coordination. Some DOE and DP laboratories have substantial infrastructure which match well industry development-applications needs; interlaboratory partnerships in this area are encouraged. Funding for basic science research programs should be maintained at FY1993 levels, adjusted for inflation; OBES plans should be updated and monitored to maintain the balance between basic research and facilities construction and operation. The recommendations are discussed in detail in this document

Analysis of turbulent wake behind a wind turbine

DEFF Research Database (Denmark)

Kermani, Nasrin Arjomand; Andersen, Søren Juhl; Sørensen, Jens Nørkær

2013-01-01

The aim of this study is to improve the classical analytical model for estimation of the rate of wake expansion and the decay of wake velocity deficit in the far wake region behind a wind turbine. The relations for a fully turbulent axisymmetric far wake were derived by applying the mass and mome...

DIELECTRIC WAKE FIELD RESONATOR ACCELERATOR MODULE

Energy Technology Data Exchange (ETDEWEB)

Hirshfield, Jay L.

2013-11-06

Results are presented from experiments, and numerical analysis of wake fields set up by electron bunches passing through a cylindrical or rectangular dielectric-lined structure. These bunches excite many TM-modes, with Ez components of the wake fields sharply localized on the axis of the structure periodically behind the bunches. The experiment with the cylindrical structure, carried out at ATF Brookhaven National Laboratory, used up to three 50 MeV bunches spaced by one wake field period (21 cm) to study the superposition of wake fields by measuring the energy loss of each bunch after it passed through the 53-cm long dielectric element. The millimeter-wave spectrum of radiation excited by the passage of bunches is also studied. Numerical analysis was aimed not only to simulate the behavior of our device, but in general to predict dielectric wake field accelerator performance. It is shown that one needs to match the radius of the cylindrical dielectric channel with the bunch longitudinal rms-length to achieve optimal performance.

Teaching Basic Science Content via Real-World Applications: A College-Level Summer Course in Veterinary Anatomy and Physiology

Science.gov (United States)

Maza, Paul; Miller, Allison; Carson, Brian; Hermanson, John

2018-01-01

Learning and retaining science content may be increased by applying the basic science material to real-world situations. Discussing cases with students during lectures and having them participate in laboratory exercises where they apply the science content to practical situations increases students' interest and enthusiasm. A summer course in…

The Transition from Thick to Thin Plate Wake Physics: Whither Vortex Shedding?

Science.gov (United States)

Rai, Man Mohan

2016-01-01

The near and very near wake of a flat plate with a circular trailing edge is investigated with data from direct numerical simulations. Computations were performed for six different combinations of the Reynolds numbers based on plate thickness (D) and boundary layer momentum thickness upstream of the trailing edge (theta). Unlike the case of the cylinder, these Reynolds numbers are independent parameters for the flat plate. The separating boundary layers are turbulent in all the cases investigated. One objective of the study is to understand the changes in the wake vortex shedding process as the plate thickness is reduced (increasing theta/D). The value of D varies by a factor of 16 and that of theta by approximately 5 in the computations. Vortex shedding is vigorous in the low theta/D cases with a substantial decrease in shedding intensity in the large theta/D cases. Other shedding characteristics are also significantly altered with increasing theta/D. A visualization of the shedding process in the different cases is provided and discussed. The basic shedding mechanism is explored in depth. The effect of changing theta/D on the time-averaged, near-wake velocity statistics is also discussed. A functional relationship between the shedding frequency and the Reynolds numbers mentioned above is obtained.

THE NEUROBIOLOGY OF SLEEP AND WAKEFULNESS

Science.gov (United States)

Schwartz, Michael D.; Kilduff, Thomas S.

2015-01-01

SYNOPSIS Since the discovery of Rapid Eye Movement (REM) sleep in the late 1950s, identification of the neural circuitry underlying wakefulness, sleep onset and the alternation between REM and non-REM (NREM) sleep has been an active area of investigation. Synchronization and desynchronization of cortical activity as detected in the electroencephalogram (EEG) is due to a corticothalamocortical loop, intrinsic cortical oscillators, monoaminergic and cholinergic afferent input to the thalamus, and the basal forebrain cholinergic input directly to the cortex. The monoaminergic and cholinergic systems are largely wake-promoting; the brainstem cholinergic nuclei are also involved in REM sleep regulation. These wake-promoting systems receive excitatory input from the hypothalamic hypocretin/orexin system. Sleep-promoting nuclei are GABAergic in nature and found in the preoptic area, brainstem and lateral hypothalamus. Although the pons is critical for the expression of REM sleep, recent research has suggested that melanin-concentrating hormone/GABAergic cells in the lateral hypothalamus "gate" REM sleep. The temporal distribution of sleep and wakefulness is due to interaction between the circadian system and the sleep homeostatic system. Although the hypothalamic suprachiasmatic nuclei contain the circadian pacemaker, the neural circuitry underlying the sleep homeostat is less clear. Prolonged wakefulness results in the accumulation of extracellular adenosine, possibly from glial sources, which is an important feedback molecule for the sleep homeostatic system. Cortical neuronal nitric oxide (nNOS) neurons may also play a role in propagating slow waves through the cortex in NREM sleep. Several neuropeptides and other neurochemicals likely play important roles in sleep/wake control. Although the control of sleep and wakefulness seemingly involves multiple redundant systems, each of these systems provides a vulnerability that can result in sleep/wake dysfunction that may

Wake Measurements in ECN's Scaled Wind Farm

Energy Technology Data Exchange (ETDEWEB)

Wagenaar, J.W.; Schepers, J.G. [ECN Wind Energy, Petten (Netherlands)

2013-02-15

In ECN's scaled wind farm the wake evolution is studied in two different situations. A single wake is studied at two different locations downstream of a turbine and a single wake is studied in conjunction with a triple wake. Here, the wake is characterized by the wind speed ratio, the turbulence intensity, the vertical wind speed and the turbulence (an)isotropy. Per situation all wake measurements are taken simultaneously together with the inflow conditions.

Comparison of a Coupled Near and Far Wake Model With a Free Wake Vortex Code

DEFF Research Database (Denmark)

Pirrung, Georg; Riziotis, Vasilis; Aagaard Madsen, Helge

2016-01-01

to be updated during the computation. Further, the effect of simplifying the exponential function approximation of the near wake model to increase the computation speed is investigated in this work. A modification of the dynamic inflow weighting factors of the far wake model is presented that ensures good...... computations performed using a free wake panel code. The focus of the description of the aerodynamics model is on the numerical stability, the computation speed and the accuracy of 5 unsteady simulations. To stabilize the near wake model, it has to be iterated to convergence, using a relaxation factor that has...... and a BEM model is centered around the NREL 5 MW reference turbine. The response to pitch steps at different pitching speeds is compared. By means of prescribed vibration cases, the effect of the aerodynamic model on the predictions of the aerodynamic work is investigated. The validation shows that a BEM...

The energy-climate continuum lessons from basic science and history

CERN Document Server

Bret, Antoine

2014-01-01

An entertaining, highly informative introduction to the intimate linkage between the energy and climate debates Illustrates the basic science behind energy and climate with back-of-the-envelope calculations, that even non-experts can easily follow without a calculator Thus provides an access to getting an accurate feeling for orders of magnitudes from simple estimations A conversation starter for some of the most debated topics of today Compares the actual situation with historic cases of societies at a turning point and finds warning as well as encouraging examples For everyone, who wan

Wake simulation for wind turbines with a free, prescribed- and hybrid-wake method

Energy Technology Data Exchange (ETDEWEB)

Bareiss, R.; Guidati, G.; Wagner, S. [Univ. Stuttgart, Inst. fuer Aerodynamik und Gasdynamik, Stuttgart (Germany)

1997-08-01

Calculations of the radial distribution and the time history of the induction factors have been performed with a number of different wake models implemented in a vortex-lattice method for tip-speed ratios in the range 1-13. The new models lead to a significant reduction of the computational effort down to 3-27% compared to a free-wake model with errors less than 5%. (au)

Verification of the SLC wake potentials

International Nuclear Information System (INIS)

Bane, K.; Weiland, T.

1983-01-01

The accurate knowledge of the monopole, dipole, and quadrupole wake potentials is essential for SLC. These wake potentials were previously computed by the modal method. The time domain code TBCI allows independent verification of these results. This comparison shows that the two methods agree to within 10% for bunch lengths down to 1 mm. TBCI results also indicate that rounding the irises gives at least a 10% reduction in the wake potentials

GPRA (Government Performance and Results Act) and research evaluation for basic science

International Nuclear Information System (INIS)

Takahashi, Shoji

2002-08-01

The purpose of the Government Performance and Results Act of 1993 (GPRA) is to ask federal agencies for evaluating their program performance especially from cost-efficiency aspect and to report to Congress. GPRA is to hold agencies accountable for their programs by requiring that they think strategically (in most cases every 5 years) and set, measure and report goals annually. The agencies which have responsibilities for enhancing basic science like Department of Energy (DOE) and National Science Fund (NSF) are not excluded by reasons of the difficulties of economic evaluations. In Japan, based on 'the Rationalization program for the public corporations' of 2001, the research developing type corporations should make a cost-performance evaluation in addition to the conventional ones. They have same theme as US agencies struggles. The purpose of this report is to get some hints for this theme by surveying GPRA reports of DOE and NSF and analyzing related information. At present, I have to conclude although everybody accepts the necessities of socio-economic evaluations and investment criteria for basic research, studies and discussions about ways and means are still continuing even in the US. (author)

Comparing offshore wind farm wake observed from satellite SAR and wake model results

Science.gov (United States)

Bay Hasager, Charlotte

2014-05-01

Offshore winds can be observed from satellite synthetic aperture radar (SAR). In the FP7 EERA DTOC project, the European Energy Research Alliance project on Design Tools for Offshore Wind Farm Clusters, there is focus on mid- to far-field wind farm wakes. The more wind farms are constructed nearby other wind farms, the more is the potential loss in annual energy production in all neighboring wind farms due to wind farm cluster effects. It is of course dependent upon the prevailing wind directions and wind speed levels, the distance between the wind farms, the wind turbine sizes and spacing. Some knowledge is available within wind farm arrays and in the near-field from various investigations. There are 58 offshore wind farms in the Northern European seas grid connected and in operation. Several of those are spaced near each other. There are several twin wind farms in operation including Nysted-1 and Rødsand-2 in the Baltic Sea, and Horns Rev 1 and Horns Rev 2, Egmond aan Zee and Prinses Amalia, and Thompton 1 and Thompton 2 all in the North Sea. There are ambitious plans of constructing numerous wind farms - great clusters of offshore wind farms. Current investigation of offshore wind farms includes mapping from high-resolution satellite SAR of several of the offshore wind farms in operation in the North Sea. Around 20 images with wind farm wake cases have been retrieved and processed. The data are from the Canadian RADARSAT-1/-2 satellites. These observe in microwave C-band and have been used for ocean surface wind retrieval during several years. The satellite wind maps are valid at 10 m above sea level. The wakes are identified in the raw images as darker areas downwind of the wind farms. In the SAR-based wind maps the wake deficit is found as areas of lower winds downwind of the wind farms compared to parallel undisturbed flow in the flow direction. The wind direction is clearly visible from lee effects and wind streaks in the images. The wind farm wake cases

Engaging Oral Health Students in Learning Basic Science Through Assessment That Weaves in Personal Experience.

Science.gov (United States)

Leadbeatter, Delyse; Gao, Jinlong

2018-04-01

Learning basic science forms an essential foundation for oral health therapy and dentistry, but frequently students perceive it as difficult, dry, and disconnected from clinical practice. This perception is encouraged by assessment methods that reward fact memorization, such as objective examinations. This study evaluated use of a learner-centered assessment portfolio designed to increase student engagement with basic science in an oral health therapy program at the University of Sydney, Australia. The aim of this qualitative study based on focus groups was to investigate students' engagement with basic science courses following introduction of the portfolio. Three assessments were conducted in three subsequent semesters: one based on students' interest in everyday phenomena (one student, for example, explored why she had red hair); the second focussed on scientific evidence and understanding of systemic diseases; and the third explored relations between oral and general health. Students were encouraged to begin with issues from their personal experience or patient care, to focus on what they were curious about, and to ask questions they really cared about. Each student prepared a written report and gave an oral presentation to the entire cohort. After the portfolios were completed, the authors held focus groups with two cohorts of students (N=21) in 2016 and analyzed the results using Zepke's framework for student engagement research. The results showed that the students successfully interweaved personal experience into their studies and that it provided significant motivation for learning. The students described their learning in terms of connection to themselves, their peer community, and their profession. Many additional benefits were identified, from increased student engagement in all courses to appreciation of the relevance of basic science. The findings should encourage dental and allied dental educators to reconsider the effects of assessments and seek

Wind Farm Wake

DEFF Research Database (Denmark)

Hasager, Charlotte Bay; Karagali, Ioanna; Volker, Patrick

2017-01-01

On 25 January 2016 at 12:45 UTC several photographs of the offshore wind farm Horns Rev 2 were taken by helicopter pilot Gitte Lundorff with an iPhone. A very shallow layer of fog covered the sea. The photos of the fog over the sea dramatically pictured the offshore wind farm wake. Researchers got...... together to investigate the atmospheric conditions at the time of the photos by analysing local meteorological observations and wind turbine information, satellite remote sensing and nearby radiosonde data. Two wake models and one mesoscale model were used to model the case and explain what was seen....

The use of high pressure in basic, materials, and life sciences

International Nuclear Information System (INIS)

Schilling, James S.

2000-01-01

Four of the most important applications of the high pressure technique in today's science are: (1) to help identify the materials which reside deep within our earth or other heavenly bodies and determine their properties, (2) to uncover underlying systematics and critically test theoretical models, (3) to synthesize novel and useful materials not readily available by other means, and (4) to determine the effect of pressure on living organisms and explore the conditions favorable for the origin of life itself. High pressure studies currently enjoy an increasing popularity which is fueled by recent advances in the notably difficult experimental techniques. In this paper I will attempt to capture some of the current excitement in this field by offering brief synopses of selected experiments in the basic, materials, and life sciences

Detailed field test of yaw-based wake steering

DEFF Research Database (Denmark)

Fleming, P.; Churchfield, M.; Scholbrock, A.

2016-01-01

production. In the first phase, a nacelle-mounted scanning lidar was used to verify wake deflection of a misaligned turbine and calibrate wake deflection models. In the second phase, these models were used within a yaw controller to achieve a desired wake deflection. This paper details the experimental......This paper describes a detailed field-test campaign to investigate yaw-based wake steering. In yaw-based wake steering, an upstream turbine intentionally misaligns its yaw with respect to the inflow to deflect its wake away from a downstream turbine, with the goal of increasing total power...... design and setup. All data collected as part of this field experiment will be archived and made available to the public via the U.S. Department of Energy’s Atmosphere to Electrons Data Archive and Portal....

A simplified approach for simulation of wake meandering

Energy Technology Data Exchange (ETDEWEB)

Thomsen, Kenneth; Aagaard Madsen, H.; Larsen, Gunner; Juul Larsen, T.

2006-03-15

This fact-sheet describes a simplified approach for a part of the recently developed dynamic wake model for aeroelastic simulations for wind turbines operating in wake. The part described in this fact-sheet concern the meandering process only, while the other part of the simplified approach the wake deficit profile is outside the scope of the present fact-sheet. Work on simplified models for the wake deficit profile is ongoing. (au)

A multi-instructor, team-based, active-learning exercise to integrate basic and clinical sciences content.

Science.gov (United States)

Kolluru, Srikanth; Roesch, Darren M; Akhtar de la Fuente, Ayesha

2012-03-12

To introduce a multiple-instructor, team-based, active-learning exercise to promote the integration of basic sciences (pathophysiology, pharmacology, and medicinal chemistry) and clinical sciences in a doctor of pharmacy curriculum. A team-based learning activity that involved pre-class reading assignments, individual-and team-answered multiple-choice questions, and evaluation and discussion of a clinical case, was designed, implemented, and moderated by 3 faculty members from the pharmaceutical sciences and pharmacy practice departments. Student performance was assessed using a multiple-choice examination, an individual readiness assurance test (IRAT), a team readiness assurance test (TRAT), and a subjective, objective, assessment, and plan (SOAP) note. Student attitudes were assessed using a pre- and post-exercise survey instrument. Students' understanding of possible correct treatment strategies for depression improved. Students were appreciative of this true integration of basic sciences knowledge in a pharmacotherapy course and to have faculty members from both disciplines present to answer questions. Mean student score on the on depression module for the examination was 80.4%, indicating mastery of the content. An exercise led by multiple instructors improved student perceptions of the importance of team-based teaching. Integrated teaching and learning may be achieved when instructors from multiple disciplines work together in the classroom using proven team-based, active-learning exercises.

Characterization of wake region by using and emissive probe

International Nuclear Information System (INIS)

Jeong, Yong Ho

1993-02-01

An emissive probe was designed and manufactured to measure the floating and the space potentials of plasma in the wake region. The floating potential method' among various schemes was used for the measurement and analysis. To generate the wake, a plane artificial satellite with circular shape was introduced in a simply discharged argon plasma without the magnetic field. Potentials along the radial direction in and out of the wake regions of artificial satellite were measured, and plasma parameters were compared in the both regions. In the wake region, the floating potential was higher than that out of the wake, the space potential was approximately equal to that out of the wake, when the positive voltage was applied to artificial satellite, the floating and the space potentials were lower than that out of the wake and when the negative voltage was applied to artificial satellite, the floating potential was higher, the space potential was lower than that out of the wake

Collinear wake field acceleration

International Nuclear Information System (INIS)

Bane, K.L.F.; Chen, P.; Wilson, P.B.

1985-04-01

In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

On AEP prediction and wake modelling at Anholt

DEFF Research Database (Denmark)

Pena Diaz, Alfredo; Hansen, Kurt Schaldemose; Volker, Patrick

and direction. We show that the WRF model is able to reproduce such gradients relatively well by comparison to the wind farm’s SCADA. About 1.5 yr of such SCADA, further quality controlled and filtered, reveals an average wake loss of 3.87% only, whereas results from three wake models, Park, Larsen and FUGA......, show average wake losses of 3.46%, 3.69%, and 3.38%, respectively. We employ a bootstrap method to estimate the uncertainty of the wake models. As this is performed with reference to the SCADA, the results provide an idea of the uncertainty of the AEP prediction2. We find all wake models...

Adult-Rated Oceanography Part 1: A Project Integrating Ocean Sciences into Adult Basic Education Programs.

Science.gov (United States)

Cowles, S.; Collier, R.; Torres, M. K.

2004-12-01

Busy scientists seek opportunities to implement education and outreach efforts, but often don't know where to start. One easy and tested method is to form collaborations with federally-funded adult education and adult literacy programs. These programs exist in every U.S. state and territory and serve underrepresented populations through such major initiatives as adult basic education, adult secondary education (and GED preparation), and English language acquisition. These students are workers, consumers, voters, parents, grandparents, and members of every community. They have specific needs that are often overlooked in outreach activities. This presentation will describe the steps by which the Oregon Ocean Science and Math Collaborative program was developed. It is based on a partnership between the Oregon Department of Community Colleges and Workforce Development, Oregon State University College of Oceanic and Atmospheric Sciences, Oregon Sea Grant, and the OSU Hatfield Marine Science Center. It includes professional development through instructor institutes; teachers at sea and informal education opportunities; curriculum and web site development. Through the partnership described here, instructors in adult basic education programs participate in a yearlong experience in which they develop, test, and adapt innovative instructional strategies to meet the specific needs of adult learners. This, in turn, leads to new prospects for study in the areas of ocean science and math and introduces non-academic careers in marine science to a new community. Working directly with instructors, we have identified expertise level, instructional environment, instructor background and current teaching strategies used to address science literacy and numeracy goals of the adult learners in the State of Oregon. Preliminary evaluation of our ongoing project in meeting these goals will be discussed. These efforts contribute to national goals of science literacy for all, by providing

Efficient Turbulence Modeling for CFD Wake Simulations

DEFF Research Database (Denmark)

van der Laan, Paul

Wind turbine wakes can cause 10-20% annual energy losses in wind farms, and wake turbulence can decrease the lifetime of wind turbine blades. One way of estimating these effects is the use of computational fluid dynamics (CFD) to simulate wind turbines wakes in the atmospheric boundary layer. Since...... this flow is in the high Reynolds number regime, it is mainly dictated by turbulence. As a result, the turbulence modeling in CFD dominates the wake characteristics, especially in Reynolds-averaged Navier-Stokes (RANS). The present work is dedicated to study and develop RANS-based turbulence models...... verified with a grid dependency study. With respect to the standard k-ε EVM, the k-ε- fp EVM compares better with measurements of the velocity deficit, especially in the near wake, which translates to improved power deficits of the first wind turbines in a row. When the CFD metholody is applied to a large...

Dissipation of Turbulence in the Wake of a Wind Turbine

Science.gov (United States)

Lundquist, J. K.; Bariteau, L.

2015-02-01

The wake of a wind turbine is characterized by increased turbulence and decreased wind speed. Turbines are generally deployed in large groups in wind farms, and so the behaviour of an individual wake as it merges with other wakes and propagates downwind is critical in assessing wind-farm power production. This evolution depends on the rate of turbulence dissipation in the wind-turbine wake, which has not been previously quantified in field-scale measurements. In situ measurements of winds and turbulence dissipation from the wake region of a multi-MW turbine were collected using a tethered lifting system (TLS) carrying a payload of high-rate turbulence probes. Ambient flow measurements were provided from sonic anemometers on a meteorological tower located near the turbine. Good agreement between the tower measurements and the TLS measurements was established for a case without a wind-turbine wake. When an operating wind turbine is located between the tower and the TLS so that the wake propagates to the TLS, the TLS measures dissipation rates one to two orders of magnitude higher in the wake than outside of the wake. These data, collected between two and three rotor diameters downwind of the turbine, document the significant enhancement of turbulent kinetic energy dissipation rate within the wind-turbine wake. These wake measurements suggest that it may be useful to pursue modelling approaches that account for enhanced dissipation. Comparisons of wake and non-wake dissipation rates to mean wind speed, wind-speed variance, and turbulence intensity are presented to facilitate the inclusion of these measurements in wake modelling schemes.

Developing a complex systems perspective for medical education to facilitate the integration of basic science and clinical medicine.

Science.gov (United States)

Aron, David C

2017-04-01

The purpose of medical education is to produce competent and capable professional practitioners who can combine the art and science of medicine. Moreover, this process must prepare individuals to practise in a field in which knowledge is increasing and the contexts in which that knowledge is applied are changing in unpredictable ways. The 'basic sciences' are important in the training of a physician. The goal of basic science training is to learn it in a way that the material can be applied in practice. Much effort has been expended to integrate basic science and clinical training, while adding many other topics to the medical curriculum. This effort has been challenging. The aims of the paper are (1) to propose a unifying conceptual framework that facilitates knowledge integration among all levels of living systems from cell to society and (2) illustrate the organizing principles with two examples of the framework in action - cybernetic systems (with feedback) and distributed robustness. Literature related to hierarchical and holarchical frameworks was reviewed. An organizing framework derived from living systems theory and spanning the range from molecular biology to health systems management was developed. The application of cybernetic systems to three levels (regulation of pancreatic beta cell production of insulin, physician adjustment of medication for glycaemic control and development and action of performance measures for diabetes care) was illustrated. Similarly distributed robustness was illustrated by the DNA damage response system and principles underlying patient safety. Each of the illustrated organizing principles offers a means to facilitate the weaving of basic science and clinical medicine throughout the course of study. The use of such an approach may promote systems thinking, which is a core competency for effective and capable medical practice. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Department of Energy: some aspects of basic research in the chemical sciences

International Nuclear Information System (INIS)

1979-01-01

The basic research needs pertinent to DOE's specific mission are identified in the fields of combustion science, coal chemistry, reprocessing of reactor fuel and the disposal of radioactive waste, and analytical chemistry. Aspects of these fields which do not need DOE support are also identified in some cases. In addition recommendations are made on review procedures and funding, use of DOE laboratories by university and other extramural chemists, isotope availability, and critically evaluated data

Wake Vortex Avoidance System and Method

Science.gov (United States)

Shams, Qamar A. (Inventor); Zuckerwar, Allan J. (Inventor); Knight, Howard K. (Inventor)

2017-01-01

A wake vortex avoidance system includes a microphone array configured to detect low frequency sounds. A signal processor determines a geometric mean coherence based on the detected low frequency sounds. A display displays wake vortices based on the determined geometric mean coherence.

Vortex wakes of a flapping foil in a flowing soap film

Science.gov (United States)

Schnipper, Teis; Andersen, Anders; Bohr, Tomas

2008-11-01

We present an experimental study of an oscillating, symmetric foil in a vertically flowing soap film. By varying frequency and amplitude of the oscillation we explore and visualize a variety of wake structures, including von Kármán wake, reverse von Kármán wake, 2P wake, and 2P+2S wake. We characterize the transition from the von Kármán wake (drag) to the reverse von Kármán wake (thrust) and discuss the results in relation to fish swimming. We visualize the time evolution of the vortex shedding in detail, identify the origins of the vortices comprising the wake, and propose a simple model to account for the transition from von Kármán like wakes to more exotic wake structures.

Characterization of forced response of density stratified reacting wake

Science.gov (United States)

Pawar, Samadhan A.; Sujith, Raman I.; Emerson, Benjamin; Lieuwen, Tim

2018-02-01

The hydrodynamic stability of a reacting wake depends primarily on the density ratio [i.e., ratio of unburnt gas density (ρu) to burnt gas density (ρb)] of the flow across the wake. The variation of the density ratio from high to low value, keeping ρ u / ρ b > 1 , transitions dynamical characteristics of the reacting wake from a linearly globally stable (or convectively unstable) to a globally unstable mode. In this paper, we propose a framework to analyze the effect of harmonic forcing on the deterministic and synchronization characteristics of reacting wakes. Using the recurrence quantification analysis of the forced wake response, we show that the deterministic behaviour of the reacting wake increases as the amplitude of forcing is increased. Furthermore, for different density ratios, we found that the synchronization of the top and bottom branches of the wake with the forcing signal is dependent on whether the mean frequency of the natural oscillations of the wake (fn) is lesser or greater than the frequency of external forcing (ff). We notice that the response of both branches (top and bottom) of the reacting wake to the external forcing is asymmetric and symmetric for the low and high density ratios, respectively. Furthermore, we characterize the phase-locking behaviour between the top and bottom branches of the wake for different values of density ratios. We observe that an increase in the density ratio results in a gradual decrease in the relative phase angle between the top and bottom branches of the wake, which leads to a change in the vortex shedding pattern from a sinuous (anti-phase) to a varicose (in-phase) mode of the oscillations.

Crosswind Shear Gradient Affect on Wake Vortices

Science.gov (United States)

Proctor, Fred H.; Ahmad, Nashat N.

2011-01-01

Parametric simulations with a Large Eddy Simulation (LES) model are used to explore the influence of crosswind shear on aircraft wake vortices. Previous studies based on field measurements, laboratory experiments, as well as LES, have shown that the vertical gradient of crosswind shear, i.e. the second vertical derivative of the environmental crosswind, can influence wake vortex transport. The presence of nonlinear vertical shear of the crosswind velocity can reduce the descent rate, causing a wake vortex pair to tilt and change in its lateral separation. The LES parametric studies confirm that the vertical gradient of crosswind shear does influence vortex trajectories. The parametric results also show that vortex decay from the effects of shear are complex since the crosswind shear, along with the vertical gradient of crosswind shear, can affect whether the lateral separation between wake vortices is increased or decreased. If the separation is decreased, the vortex linking time is decreased, and a more rapid decay of wake vortex circulation occurs. If the separation is increased, the time to link is increased, and at least one of the vortices of the vortex pair may have a longer life time than in the case without shear. In some cases, the wake vortices may never link.

Performance and wake conditions of a rotor located in the wake of an obstacle

DEFF Research Database (Denmark)

Naumov, I. V.; Kabardin, I. K.; Mikkelsen, Robert Flemming

2016-01-01

and associated pulsations as a function of the incoming flow structures were measured by strain gauges. The flow condition in front of the rotor was measured with high temporal accuracy using LDA and power coefficients were determine as function of tip speed ratio for different obstacle positions. Furthermore......Obstacles like forests, ridges and hills can strongly affect the velocity profile in front of a wind turbine rotor. The present work aims at quantifying the influence of nearby located obstacles on the performance and wake characteristics of a downstream located wind turbine. Here the influence......, PIV measurements were carried out to study the development of the mean velocity deficit profiles of the wake behind the wind turbine model under the influence of the wake generated by the obstacle. By use of regression techniques to fit the velocity profiles it was possible to determine velocity...

Meteorological Controls on Wind Turbine Wakes

DEFF Research Database (Denmark)

Barthelmie, Rebecca J.; Hansen, Kurt Schaldemose; Pryor, S.C.

2013-01-01

, modeling, and predicting this complex and interdependent system is therefore critical to understanding and modeling wind farm power losses due to wakes, and to optimizing wind farm layout. This paper quantifies the impact of these variables on the power loss due to wakes using data from the large offshore......The primary control on the magnitude of the power losses induced by wind turbine wakes in large wind farms is the hub-height wind speed via its link to the turbine thrust coefficient. Hence, at low to moderate wind speeds (between cut-in and rated turbine wind speeds) when the thrust coefficient...

Wind Turbine Wake in Atmospheric Turbulence

DEFF Research Database (Denmark)

Réthoré, Pierre-Elouan Mikael

to calibrate faster and simpler engineering wind farm wake models. The most attractive solution was the actuator disc method with the steady state k-ε turbulence model. The first step to design such a tool is the treatment of the forces. This thesis presents a computationally inexpensive method to apply......) shows that the problem mainly comes from the assumptions of the eddy-viscosity concept, which are deeply invalidated in the wind turbine wake region. Different models that intent to correct the k-ε model’s issues are investigated, of which none of them is found to be adequate. The mixing of the wake...

Influence of obstacle aspect ratio on tripped cylinder wakes

International Nuclear Information System (INIS)

Araújo, Tiago B.; Sicot, Christophe; Borée, Jacques; Martinuzzi, Robert J.

2012-01-01

Highlights: ► Influence of a tripwire on wake properties of a surface-mounted circular cylinder. ► Height-to-diameter aspect ratios of 3 and 6 are considered. ► Critical positions for the tripwire lead to an abrupt change in the wake structure. ► Results further suggest that the tripwire can strengthen 2D wake properties. - Abstract: The influence of an asymmetrically mounted, single tripwire on the shedding and wake characteristics of a vertical, surface-mounted finite circular cylinder is investigated experimentally. Height-to-diameter aspect ratios of 3 and 6 are considered. It is shown that a critical position for the tripwire exists, which is characterised in an abrupt change in the shedding frequency and wake structure. Results further suggest that the tripwire can strengthen 2D wake properties. The influence of the aspect ratio is due to tip-wake flow interactions and thus differs fundamentally from two-dimensional geometries.

The Future of Basic Science in Academic Surgery: Identifying Barriers to Success for Surgeon-scientists.

Science.gov (United States)

Keswani, Sundeep G; Moles, Chad M; Morowitz, Michael; Zeh, Herbert; Kuo, John S; Levine, Matthew H; Cheng, Lily S; Hackam, David J; Ahuja, Nita; Goldstein, Allan M

2017-06-01

The aim of this study was to examine the challenges confronting surgeons performing basic science research in today's academic surgery environment. Multiple studies have identified challenges confronting surgeon-scientists and impacting their ability to be successful. Although these threats have been known for decades, the downward trend in the number of successful surgeon-scientists continues. Clinical demands, funding challenges, and other factors play important roles, but a rigorous analysis of academic surgeons and their experiences regarding these issues has not previously been performed. An online survey was distributed to 2504 members of the Association for Academic Surgery and Society of University Surgeons to determine factors impacting success. Survey results were subjected to statistical analyses. We also reviewed publicly available data regarding funding from the National Institutes of Health (NIH). NIH data revealed a 27% decline in the proportion of NIH funding to surgical departments relative to total NIH funding from 2007 to 2014. A total of 1033 (41%) members responded to our survey, making this the largest survey of academic surgeons to date. Surgeons most often cited the following factors as major impediments to pursuing basic investigation: pressure to be clinically productive, excessive administrative responsibilities, difficulty obtaining extramural funding, and desire for work-life balance. Surprisingly, a majority (68%) did not believe surgeons can be successful basic scientists in today's environment, including departmental leadership. We have identified important barriers that confront academic surgeons pursuing basic research and a perception that success in basic science may no longer be achievable. These barriers need to be addressed to ensure the continued development of future surgeon-scientists.

Characterization of an Actively Controlled Three-Dimensional Turret Wake

Science.gov (United States)

Shea, Patrick; Glauser, Mark

2012-11-01

Three-dimensional turrets are commonly used for housing optical systems on airborne platforms. As bluff bodies, these geometries generate highly turbulent wakes that decrease the performance of the optical systems and the aircraft. The current experimental study looked to use dynamic suction in both open and closed-loop control configurations to actively control the turret wake. The flow field was characterized using dynamic pressure and stereoscopic PIV measurements in the wake of the turret. Results showed that the suction system was able to manipulate the wake region of the turret and could alter not only the spatial structure of the wake, but also the temporal behavior of the wake flow field. Closed-loop, feedback control techniques were used to determine a more optimal control input for the flow control. Similar control effects were seen for both the steady open-loop control case and the closed-loop feedback control configuration with a 45% reduction in the suction levels when comparing the closed-loop to the open-loop case. These results provide unique information regarding the development of the baseline three-dimensional wake and the wake with three different active flow control configurations.

Wake field in electron-positron plasmas

International Nuclear Information System (INIS)

Avinash, K.; Berezhiani, V.I.

1993-03-01

We study the creation of wake field in cold electron positron plasma by electron bunches. In the resulting plasma inhomogeneity we study the propagation of short electromagnetic pulse. In is found that wake fields can change the frequency of the radiation substantially. (author). 7 refs, 1 fig

Wake-vortex decay in external turbulence

NARCIS (Netherlands)

Kuczaj, Arkadiusz K.; Armenio, V.; Fröhlich, J.; Geurts, Bernardus J.

2010-01-01

Wake vortices that form behind a moving aircraft represent 11 safety COil cern for other aircraft.s that follow. These tornado-like wake structures may persist for several minutes, extending for many kilometers across the sky. This safety issue is particularly important close to major airports where

Effects of outer perturbances on dynamics of wake vortices

International Nuclear Information System (INIS)

Baranov, N.A.; Belotserkovsky, A.S.; Turchak, L.I.

2004-01-01

One of the problems in aircraft flight safety is reduction of the risk related with aircraft encounter with wake vortices generated by other aircraft. An efficient approach to this problem is design of systems providing information on areas of potential danger of wake vortices to pilots in real time. The main components of such a system are a unit for calculations of wake vortices behind aircraft and a unit for calculations of areas of potential danger. A promising way to development of real time algorithms for calculation of wake vortices is the use of vortex methods in CFD based on the hypothesis of quasi-3D flow in the area of wake vorticity. The mathematical model developed by our team calculates positions and intensity of wake vortices past aircraft taking account of such effects as viscous dissipation of vortices, effects of ambient turbulence, wind shear, as well as viscous interaction between wake vortices and the underlying surface. The necessity of including the last factor could be stems from the fact that in the case where wake vortices are in close proximity of the rigid surface, the viscous interaction between the wake vortices and the surface boundary layer results in the boundary layer separation changing the overall intensity and dynamics of the wake vortices. To evaluate the boundaries of the danger areas the authors use an approach based on calculation of additional aerodynamic forces and moments acting on the aircraft encountering wake vortices by means of evaluation of the aircraft additional velocities and angular rates corresponding to distribution of disturbed velocities on the aircraft surface. These criteria could be based on local characteristics of the vorticity areas or on characteristics related to the perturbation effects on the aircraft. The latter characteristics include the actual aerodynamic roll moment, the maximum angular rate or the maximum roll of the aircraft under perturbations in the wake vortices. To estimate the accuracy

Why Does Sleep Slow-Wave Activity Increase After Extended Wake? Assessing the Effects of Increased Cortical Firing During Wake and Sleep.

Science.gov (United States)

Rodriguez, Alexander V; Funk, Chadd M; Vyazovskiy, Vladyslav V; Nir, Yuval; Tononi, Giulio; Cirelli, Chiara

2016-12-07

During non-rapid eye movement (NREM) sleep, cortical neurons alternate between ON periods of firing and OFF periods of silence. This bi-stability, which is largely synchronous across neurons, is reflected in the EEG as slow waves. Slow-wave activity (SWA) increases with wake duration and declines homeostatically during sleep, but the underlying mechanisms remain unclear. One possibility is neuronal "fatigue": high, sustained firing in wake would force neurons to recover with more frequent and longer OFF periods during sleep. Another possibility is net synaptic potentiation during wake: stronger coupling among neurons would lead to greater synchrony and therefore higher SWA. Here, we obtained a comparable increase in sustained firing (6 h) in cortex by: (1) keeping mice awake by exposure to novel objects to promote plasticity and (2) optogenetically activating a local population of cortical neurons at wake-like levels during sleep. Sleep after extended wake led to increased SWA, higher synchrony, and more time spent OFF, with a positive correlation between SWA, synchrony, and OFF periods. Moreover, time spent OFF was correlated with cortical firing during prior wake. After local optogenetic stimulation, SWA and cortical synchrony decreased locally, time spent OFF did not change, and local SWA was not correlated with either measure. Moreover, laser-induced cortical firing was not correlated with time spent OFF afterward. Overall, these results suggest that high sustained firing per se may not be the primary determinant of SWA increases observed after extended wake. A long-standing hypothesis is that neurons fire less during slow-wave sleep to recover from the "fatigue" accrued during wake, when overall synaptic activity is higher than in sleep. This idea, however, has rarely been tested and other factors, namely increased cortical synchrony, could explain why sleep slow-wave activity (SWA) is higher after extended wake. We forced neurons in the mouse cortex to fire

Longitudinal and transverse wake potentials in SLAC

International Nuclear Information System (INIS)

Bane, K.; Wilson, P.

1980-01-01

In a machine with short bunches of high peak currents, such as the SLAC collider, one needs to know the longitudinal wake potential, for the higher mode losses, and the transverse wake potential, since, for bunches passing slightly off axis, the induced transverse forces will tend to cause beam break up. The longitudinal and transverse wakes of the SLAC structure presented here, were calculated by computer using the modal method, and including an analytic extension for higher modes. (Auth.)

Performance evaluation of an automated single-channel sleep–wake detection algorithm

Directory of Open Access Journals (Sweden)

Kaplan RF

2014-10-01

Full Text Available Richard F Kaplan,1 Ying Wang,1 Kenneth A Loparo,1,2 Monica R Kelly,3 Richard R Bootzin3 1General Sleep Corporation, Euclid, OH, USA; 2Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, USA; 3Department of Psychology, University of Arizona, Tucson, AZ, USA Background: A need exists, from both a clinical and a research standpoint, for objective sleep measurement systems that are both easy to use and can accurately assess sleep and wake. This study evaluates the output of an automated sleep–wake detection algorithm (Z-ALG used in the Zmachine (a portable, single-channel, electroencephalographic [EEG] acquisition and analysis system against laboratory polysomnography (PSG using a consensus of expert visual scorers. Methods: Overnight laboratory PSG studies from 99 subjects (52 females/47 males, 18–60 years, median age 32.7 years, including both normal sleepers and those with a variety of sleep disorders, were assessed. PSG data obtained from the differential mastoids (A1–A2 were assessed by Z-ALG, which determines sleep versus wake every 30 seconds using low-frequency, intermediate-frequency, and high-frequency and time domain EEG features. PSG data were independently scored by two to four certified PSG technologists, using standard Rechtschaffen and Kales guidelines, and these score files were combined on an epoch-by-epoch basis, using a majority voting rule, to generate a single score file per subject to compare against the Z-ALG output. Both epoch-by-epoch and standard sleep indices (eg, total sleep time, sleep efficiency, latency to persistent sleep, and wake after sleep onset were compared between the Z-ALG output and the technologist consensus score files. Results: Overall, the sensitivity and specificity for detecting sleep using the Z-ALG as compared to the technologist consensus are 95.5% and 92.5%, respectively, across all subjects, and the positive predictive value and the

An Elective Course on the Basic and Clinical Sciences Aspects of Vitamins and Minerals

Science.gov (United States)

2013-01-01

Objective. To develop and implement an elective course on vitamins and minerals and their usefulness as dietary supplements. Design. A 2-credit-hour elective course designed to provide students with the most up-to-date basic and clinical science information on vitamins and minerals was developed and implemented in the doctor of pharmacy (PharmD) curriculum. In addition to classroom lectures, an active-learning component was incorporated in the course in the form of group discussion. Assessment. Student learning was demonstrated by examination scores. Performance on pre- and post-course surveys administered in 2011 demonstrated a significant increase in students’ knowledge of the basic and clinical science aspects of vitamins and minerals, with average scores increasing from 61% to 86%. At the end of the semester, students completed a standard course evaluation. Conclusion. An elective course on vitamin and mineral supplements was well received by pharmacy students and helped them to acquire knowledge and competence in patient counseling regarding safe, appropriate, effective, and economical use of these products. PMID:23463149

An elective course on the basic and clinical sciences aspects of vitamins and minerals.

Science.gov (United States)

Islam, Mohammed A

2013-02-12

Objective. To develop and implement an elective course on vitamins and minerals and their usefulness as dietary supplements. Design. A 2-credit-hour elective course designed to provide students with the most up-to-date basic and clinical science information on vitamins and minerals was developed and implemented in the doctor of pharmacy (PharmD) curriculum. In addition to classroom lectures, an active-learning component was incorporated in the course in the form of group discussion. Assessment. Student learning was demonstrated by examination scores. Performance on pre- and post-course surveys administered in 2011 demonstrated a significant increase in students' knowledge of the basic and clinical science aspects of vitamins and minerals, with average scores increasing from 61% to 86%. At the end of the semester, students completed a standard course evaluation. Conclusion. An elective course on vitamin and mineral supplements was well received by pharmacy students and helped them to acquire knowledge and competence in patient counseling regarding safe, appropriate, effective, and economical use of these products.

Volumetric LiDAR scanning of a wind turbine wake and comparison with a 3D analytical wake model

Science.gov (United States)

Carbajo Fuertes, Fernando; Porté-Agel, Fernando

2016-04-01

A correct estimation of the future power production is of capital importance whenever the feasibility of a future wind farm is being studied. This power estimation relies mostly on three aspects: (1) a reliable measurement of the wind resource in the area, (2) a well-established power curve of the future wind turbines and, (3) an accurate characterization of the wake effects; the latter being arguably the most challenging one due to the complexity of the phenomenon and the lack of extensive full-scale data sets that could be used to validate analytical or numerical models. The current project addresses the problem of obtaining a volumetric description of a full-scale wake of a 2MW wind turbine in terms of velocity deficit and turbulence intensity using three scanning wind LiDARs and two sonic anemometers. The characterization of the upstream flow conditions is done by one scanning LiDAR and two sonic anemometers, which have been used to calculate incoming vertical profiles of horizontal wind speed, wind direction and an approximation to turbulence intensity, as well as the thermal stability of the atmospheric boundary layer. The characterization of the wake is done by two scanning LiDARs working simultaneously and pointing downstream from the base of the wind turbine. The direct LiDAR measurements in terms of radial wind speed can be corrected using the upstream conditions in order to provide good estimations of the horizontal wind speed at any point downstream of the wind turbine. All this data combined allow for the volumetric reconstruction of the wake in terms of velocity deficit as well as turbulence intensity. Finally, the predictions of a 3D analytical model [1] are compared to the 3D LiDAR measurements of the wind turbine. The model is derived by applying the laws of conservation of mass and momentum and assuming a Gaussian distribution for the velocity deficit in the wake. This model has already been validated using high resolution wind-tunnel measurements

Predictive validity of the comprehensive basic science examination mean score for assessment of medical students' performance

Directory of Open Access Journals (Sweden)

Firouz Behboudi

2002-04-01

Full Text Available Background Medical education curriculum improvements can be achieved bye valuating students performance. Medical students have to pass two undergraduate comprehensive examinations, basic science and preinternship, in Iran. Purpose To measure validity of the students' mean score in comprehensive basic science exam (CBSE for predicting their performance in later curriculum phases. Methods This descriptive cross-sectional study was conducted on 95 (38 women and 55 men Guilan medical university students. Their admission to the university was 81% by regional quota and 12% by shaheed and other organizations' share. They first enrolled in 1994 and were able to pass CBS£ at first try. Data on gender, regional quota, and average grades of CBS£, PC, and CPIE were collected by a questionnaire. The calculations were done by SPSS package. Results The correlation coefficient between CBS£ and CPIE mean scores (0.65 was higher than correlation coefficient between CBS£ and PC mean scores (0.49. The predictive validity of CBS£ average grade was significant for students' performance in CPIE; however, the predictive validity of CBSE mean scores for students I pe1jormance in PC was lower. Conclusion he students' mean score in CBSE can be a good denominator for their further admission. We recommend further research to assess the predictive validity for each one of the basic courses. Keywords predictive validity, comprehensive basic exam

Brain energetics during the sleep-wake cycle

DEFF Research Database (Denmark)

DiNuzzo, Mauro; Nedergaard, Maiken

2017-01-01

Brain activity during wakefulness is associated with high metabolic rates that are believed to support information processing and memory encoding. In spite of loss of consciousness, sleep still carries a substantial energy cost. Experimental evidence supports a cerebral metabolic shift taking place...... during sleep that suppresses aerobic glycolysis, a hallmark of environment-oriented waking behavior and synaptic plasticity. Recent studies reveal that glial astrocytes respond to the reduction of wake-promoting neuromodulators by regulating volume, composition and glymphatic drainage of interstitial...

Basic science faculty in surgical departments: advantages, disadvantages and opportunities.

Science.gov (United States)

Chinoy, Mala R; Moskowitz, Jay; Wilmore, Douglas W; Souba, Wiley W

2005-01-01

The number of Ph.D. faculty in clinical departments now exceeds the number of Ph.D. faculty in basic science departments. Given the escalating pressures on academic surgeons to produce in the clinical arena, the recruitment and retention of high-quality Ph.D.s will become critical to the success of an academic surgical department. This success will be as dependent on the surgical faculty understanding the importance of the partnership as the success of the Ph.D. investigator. Tighter alignment among the various clinical and research programs and between surgeons and basic scientists will facilitate the generation of new knowledge that can be translated into useful products and services (thus improving care). To capitalize on what Ph.D.s bring to the table, surgery departments may need to establish a more formal research infrastructure that encourages the ongoing exchange of ideas and resources. Physically removing barriers between the research groups, encouraging the open exchange of techniques and observations and sharing core laboratories is characteristic of successful research teams. These strategies can meaningfully contribute to developing successful training program grants, program projects and bringing greater research recognition to the department of surgery.

On atmospheric stability in the dynamic wake meandering model

DEFF Research Database (Denmark)

Keck, Rolf-Erik; de Mare, Martin Tobias; Churchfield, Matthew J.

2014-01-01

The present study investigates a new approach for capturing the effects of atmospheric stability on wind turbine wake evolution and wake meandering by using the dynamic wake meandering model. The most notable impact of atmospheric stability on the wind is the changes in length and velocity scales...... spectra and applied to the dynamic wake meandering model to capture the correct wake meandering behaviour. The ambient turbulence in all stability classes is generated using the Mann turbulence model, where the effects of non-neutral atmospheric stability are approximated by the selection of input...... in the computational domain. The changes in the turbulent length scales due to the various atmospheric stability states impact the wake meandering characteristics and thus the power generation by the individual turbines. The proposed method is compared with results from both large-eddy simulation coupled...

Integration of basic science and clinical medicine: the innovative approach of the cadaver biopsy project at the Boston University School of Medicine.

Science.gov (United States)

Eisenstein, Anna; Vaisman, Lev; Johnston-Cox, Hillary; Gallan, Alexander; Shaffer, Kitt; Vaughan, Deborah; O'Hara, Carl; Joseph, Lija

2014-01-01

Curricular integration has emerged as a consistent theme in medical education reform. Vertical integration of topics such as pathology offers the potential to bring basic science content into the clinical arena, but faculty/student acceptance and curricular design pose challenges for such integration. The authors describe the Cadaver Biopsy Project (CBP) at Boston University School of Medicine as a sustainable model of vertical integration. Faculty and select senior medical students obtained biopsies of cadavers during the first-year gross anatomy course (fall 2009) and used these to develop clinical cases for courses in histology (spring 2010), pathology (fall 2010-spring 2011), and radiology (fall 2011 or spring 2012), thereby linking students' first experiences in basic sciences with other basic science courses and later clinical courses. Project goals included engaging medical stu dents in applying basic science princi ples in all aspects of patient care as they acquire skills. The educational intervention used a patient (cadaver)-centered approach and small-group, collaborative, case-based learning. Through this project, the authors involved clinical and basic science faculty-plus senior medical students-in a collaborative project to design and implement an integrated curriculum through which students revisited, at several different points, the microscopic structure and pathophysiology of common diseases. Developing appropriate, measurable out comes for medical education initiatives, including the CBP, is challenging. Accumu lation of qualitative feedback from surveys will guide continuous improvement of the CBP. Documenting longer-term impact of the curricular innovation on test scores and other competency-based outcomes is an ultimate goal.

Professional fulfillment and parenting work-life balance in female physicians in Basic Sciences and medical research: a nationwide cross-sectional survey of all 80 medical schools in Japan.

Science.gov (United States)

Yamazaki, Yuka; Uka, Takanori; Marui, Eiji

2017-09-15

In Japan, the field of Basic Sciences encompasses clinical, academic, and translational research, as well as the teaching of medical sciences, with both an MD and PhD typically required. In this study, it was hypothesized that the characteristics of a Basic Sciences career path could offer the professional advancement and personal fulfillment that many female medical doctors would find advantageous. Moreover, encouraging interest in Basic Sciences could help stem shortages that Japan is experiencing in medical fields, as noted in the three principal contributing factors: premature resignation of female clinicians, an imbalance of female physicians engaged in research, and a shortage of medical doctors in the Basic Sciences. This study examines the professional and personal fulfillment expressed by Japanese female medical doctors who hold positions in Basic Sciences. Topics include career advancement, interest in medical research, and greater flexibility for parenting. A cross-sectional questionnaire survey was distributed at all 80 medical schools in Japan, directed to 228 female medical doctors whose academic rank was assistant professor or higher in departments of Basic Sciences in 2012. Chi-square tests and the binary logistic regression model were used to investigate the impact of parenthood on career satisfaction, academic rank, salary, etc. The survey response rate of female physicians in Basic Sciences was 54.0%. Regardless of parental status, one in three respondents cited research interest as their rationale for entering Basic Sciences, well over twice other motivations. A majority had clinical experience, with clinical duties maintained part-time by about half of respondents and particularly parents. Only one third expressed afterthoughts about relinquishing full-time clinical practice, with physicians who were parents expressing stronger regrets. Parental status had little effect on academic rank and income within the Basic Sciences, CONCLUSION

On the wake of a Darrieus turbine

Science.gov (United States)

Base, T. E.; Phillips, P.; Robertson, G.; Nowak, E. S.

1981-01-01

The theory and experimental measurements on the aerodynamic decay of a wake from high performance vertical axis wind turbine are discussed. In the initial experimental study, the wake downstream of a model Darrieus rotor, 28 cm diameter and a height of 45.5 cm, was measured in a Boundary Layer Wind Tunnel. The wind turbine was run at the design tip speed ratio of 5.5. It was found that the wake decayed at a slower rate with distance downstream of the turbine, than a wake from a screen with similar troposkein shape and drag force characteristics as the Darrieus rotor. The initial wind tunnel results indicated that the vertical axis wind turbines should be spaced at least forty diameters apart to avoid mutual power depreciation greater than ten per cent.

2014 CERN Accelerator Schools: Plasma Wake Acceleration

CERN Multimedia

2014-01-01

A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

Role of the locus coeruleus in the emergence of power law wake bouts in a model of the brainstem sleep-wake system through early infancy.

Science.gov (United States)

Patel, Mainak; Rangan, Aaditya

2017-08-07

Infant rats randomly cycle between the sleeping and waking states, which are tightly correlated with the activity of mutually inhibitory brainstem sleep and wake populations. Bouts of sleep and wakefulness are random; from P2-P10, sleep and wake bout lengths are exponentially distributed with increasing means, while during P10-P21, the sleep bout distribution remains exponential while the distribution of wake bouts gradually transforms to power law. The locus coeruleus (LC), via an undeciphered interaction with sleep and wake populations, has been shown experimentally to be responsible for the exponential to power law transition. Concurrently during P10-P21, the LC undergoes striking physiological changes - the LC exhibits strong global 0.3 Hz oscillations up to P10, but the oscillation frequency gradually rises and synchrony diminishes from P10-P21, with oscillations and synchrony vanishing at P21 and beyond. In this work, we construct a biologically plausible Wilson Cowan-style model consisting of the LC along with sleep and wake populations. We show that external noise and strong reciprocal inhibition can lead to switching between sleep and wake populations and exponentially distributed sleep and wake bout durations as during P2-P10, with the parameters of inhibition between the sleep and wake populations controlling mean bout lengths. Furthermore, we show that the changing physiology of the LC from P10-P21, coupled with reciprocal excitation between the LC and wake population, can explain the shift from exponential to power law of the wake bout distribution. To our knowledge, this is the first study that proposes a plausible biological mechanism, which incorporates the known changing physiology of the LC, for tying the developing sleep-wake circuit and its interaction with the LC to the transformation of sleep and wake bout dynamics from P2-P21. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparing satellite SAR and wind farm wake models

DEFF Research Database (Denmark)

Hasager, Charlotte Bay; Vincent, P.; Husson, R.

2015-01-01

. These extend several tens of kilometres downwind e.g. 70 km. Other SAR wind maps show near-field fine scale details of wake behind rows of turbines. The satellite SAR wind farm wake cases are modelled by different wind farm wake models including the PARK microscale model, the Weather Research and Forecasting...... (WRF) model in high resolution and WRF with coupled microscale parametrization....

Wake vortex properties and thrust production of a harmonically-pitching flexible airfoil at low Reynolds number

Science.gov (United States)

Olson, David; Naguib, Ahmed; Koochesfahani, Manoochehr

2017-11-01

Many of the natural flyers have deformable wing structures and exhibit complex kinematics in order to produce lift and thrust. Replicating all of these conditions in the laboratory (or in simulations) is extremely difficult, and drawing explicit connections to basic unsteady aerodynamics models and theories is even more complicated. Therefore, simplified wing structure and kinematics are typically used to facilitate drawing out these connections. In this work, measurements are conducted using a rigid and a chordwise-flexible NACA 0009 airfoils when harmonically pitched about the quarter chord point. Molecular tagging velocimetry is used to characterize the wake and estimate the thrust based on the momentum integral equation as function of the reduced frequency and the pitching amplitude. The results obtained using the two different airfoils are compared in order to examine the influence of structural flexibility. Consistent with the literature, chordwise flexibility is found to enhance thrust production and the circulation of the vortices shed into the wake, for a certain range of frequencies and amplitudes. Additional characterizations are undertaken of the wake vortex structure and its scaling. This work was supported by AFOSR Award Number FA9550-10-1-0342.

Evolution of plasma wakes in density up- and down-ramps

Science.gov (United States)

Zhang, C. J.; Joshi, C.; Xu, X. L.; Mori, W. B.; Li, F.; Wan, Y.; Hua, J. F.; Pai, C. H.; Wang, J.; Lu, W.

2018-02-01

The time evolution of plasma wakes in density up- and down-ramps is examined through theory and particle-in-cell simulations. Motivated by observation of the reversal of a linear plasma wake in a plasma density upramp in a recent experiment (Zhang et al 2017 Phys. Rev. Lett. 119 064801) we have examined the behaviour of wakes in plasma ramps that always accompany any plasma source used for plasma-based acceleration. In the up-ramp case it is found that, after the passage of the drive pulse, the wavnumber/wavelength of the wake starts to decrease/increase with time until it eventually tends to zero/infinity, then the wake reverses its propagation direction and the wavenunber/wavelength of the wake begins to increase/shrink. The evolutions of the wavenumber and the phase velocity of the wake as functions of time are shown to be significantly different in the up-ramp and the down-ramp cases. In the latter case the wavenumber of the wake at a particular position in the ramp increases until the wake is eventually damped. It is also shown that the waveform of the wake at a particular time after being excited can be precisely controlled by tuning the initial plasma density profile, which may enable a new type of plasma-based ultrafast optics.

Validation of the Eddy Viscosity and Lange Wake Models using Measured Wake Flow Characteristics Behind a Large Wind Turbine Rotor

Energy Technology Data Exchange (ETDEWEB)

Jeon, Sang Hyeon; Kim, Bum Suk; Huh, Jong Chul [Jeju National Univ., Jeju (Korea, Republic of); Go, Young Jun [Hanjin Ind, Co., Ltd., Yangsan (Korea, Republic of)

2016-01-15

The wake effects behind wind turbines were investigated by using data from a Met Mast tower and the SCADA (Supervisory Control and Data Acquisition) system for a wind turbine. The results of the wake investigations and predicted values for the velocity deficit based on the eddy viscosity model were compared with the turbulence intensity from the Lange model. As a result, the velocity deficit and turbulence intensity of the wake increased as the free stream wind speed decreased. In addition, the magnitude of the velocity deficit for the center of the wake using the eddy viscosity model was overestimated while the turbulence intensity from the Lange model showed similarities with measured values.

Hurdles in Basic Science Translation

Directory of Open Access Journals (Sweden)

Christina J. Perry

2017-07-01

Full Text Available In the past century there have been incredible advances in the field of medical research, but what hinders translation of this knowledge into effective treatment for human disease? There is an increasing focus on the failure of many research breakthroughs to be translated through the clinical trial process and into medical practice. In this mini review, we will consider some of the reasons that findings in basic medical research fail to become translated through clinical trials and into basic medical practices. We focus in particular on the way that human disease is modeled, the understanding we have of how our targets behave in vivo, and also some of the issues surrounding reproducibility of basic research findings. We will also look at some of the ways that have been proposed for overcoming these issues. It appears that there needs to be a cultural shift in the way we fund, publish and recognize quality control in scientific research. Although this is a daunting proposition, we hope that with increasing awareness and focus on research translation and the hurdles that impede it, the field of medical research will continue to inform and improve medical practice across the world.

Vortex wakes of a flapping foil in a flowing soap film

DEFF Research Database (Denmark)

We present an experimental study of an oscillating, symmetric foil in a vertically flowing soap film. By varying frequency and amplitude of the oscillation we explore and visualize a variety of wake structures, including von K´arm´an wake, reverse von K´arm´an wake, 2P wake, and 2P+2S wake. We...

The HelCat basic plasma science device

Science.gov (United States)

Gilmore, M.; Lynn, A. G.; Desjardins, T. R.; Zhang, Y.; Watts, C.; Hsu, S. C.; Betts, S.; Kelly, R.; Schamiloglu, E.

2015-01-01

The Helicon-Cathode(HelCat) device is a medium-size linear experiment suitable for a wide range of basic plasma science experiments in areas such as electrostatic turbulence and transport, magnetic relaxation, and high power microwave (HPM)-plasma interactions. The HelCat device is based on dual plasma sources located at opposite ends of the 4 m long vacuum chamber - an RF helicon source at one end and a thermionic cathode at the other. Thirteen coils provide an axial magnetic field B >= 0.220 T that can be configured individually to give various magnetic configurations (e.g. solenoid, mirror, cusp). Additional plasma sources, such as a compact coaxial plasma gun, are also utilized in some experiments, and can be located either along the chamber for perpendicular (to the background magnetic field) plasma injection, or at one of the ends for parallel injection. Using the multiple plasma sources, a wide range of plasma parameters can be obtained. Here, the HelCat device is described in detail and some examples of results from previous and ongoing experiments are given. Additionally, examples of planned experiments and device modifications are also discussed.

Circadian Rhythm Sleep-Wake Disorders in Older Adults.

Science.gov (United States)

Kim, Jee Hyun; Duffy, Jeanne F

2018-03-01

The timing, duration, and consolidation of sleep result from the interaction of the circadian timing system with a sleep-wake homeostatic process. When aligned and functioning optimally, this allows wakefulness throughout the day and a long consolidated sleep episode at night. Mismatch between the desired timing of sleep and the ability to fall and remain asleep is a hallmark of the circadian rhythm sleep-wake disorders. This article discusses changes in circadian regulation of sleep with aging; how age influences the prevalence, diagnosis, and treatment of circadian rhythm sleep-wake disorders; and how neurologic diseases in older patients affect circadian rhythms and sleep. Copyright © 2017 Elsevier Inc. All rights reserved.

Wind Wake Watcher v. 1.0

Energy Technology Data Exchange (ETDEWEB)

2017-10-03

This software enables the user to produce Google Earth visualizations of turbine wake effects for wind farms. The visualizations are based on computations of statistical quantities that vary with wind direction and help quantify the effects on power production of upwind turbines on turbines in their wakes. The results of the software are plot images and kml files that can be loaded into Google Earth. The statistics computed are described in greater detail in the paper: S. Martin, C. H. Westergaard, and J. White (2016), Visualizing Wind Farm Wakes Using SCADA Data, in Wither Turbulence and Big Data in the 21st Century? Eds. A. Pollard, L. Castillo, L. Danaila, and M. Glauser. Springer, pgs. 231-254.

Wake structure of a single vertical axis wind turbine

International Nuclear Information System (INIS)

Posa, Antonio; Parker, Colin M.; Leftwich, Megan C.; Balaras, Elias

2016-01-01

Highlights: • The wake structure of an isolated Vertical Axis Wind Turbine is studied by both Particle Imaging Velocimetry and Large Eddy Simulation. • The wake structure is investigated for two values of tip speed ratio, TSR_1=1.35 and TSR_2=2.21. • A displacement of the momentum deficit towards the windward side is verified in the wake. • Higher turbulence and coherence is observed on the leeward side of the wake, due to the upwind stall of the blades. • Coherence in the wake core, associated to the downwind stall, decays quickly downstream. - Abstract: The wake structure behind a vertical axis wind turbine (VAWT) is both measured in a wind tunnel using particle imaging velocimetry (PIV) and computed with large-eddy simulation (LES). Geometric and dynamic conditions are closely matched to typical applications of VAWTs (Re_D ∼ 1.8 × 10"5). The experiments and computations were highly coordinated with continuous two-way feedback to produce the most insightful results. Good qualitative agreement is seen between the computational and experimental results. The dependence of the wake structure on the tip speed ratio, TSR, is investigated, showing higher asymmetry and larger vortices at the lower rotational speed, due to stronger dynamic stall phenomena. Instantaneous, ensemble-averaged and phase-averaged fields are discussed, as well as the dynamics of coherent structures in the rotor region and downstream wake.

Stochastic Wake Modelling Based on POD Analysis

Directory of Open Access Journals (Sweden)

David Bastine

2018-03-01

Full Text Available In this work, large eddy simulation data is analysed to investigate a new stochastic modeling approach for the wake of a wind turbine. The data is generated by the large eddy simulation (LES model PALM combined with an actuator disk with rotation representing the turbine. After applying a proper orthogonal decomposition (POD, three different stochastic models for the weighting coefficients of the POD modes are deduced resulting in three different wake models. Their performance is investigated mainly on the basis of aeroelastic simulations of a wind turbine in the wake. Three different load cases and their statistical characteristics are compared for the original LES, truncated PODs and the stochastic wake models including different numbers of POD modes. It is shown that approximately six POD modes are enough to capture the load dynamics on large temporal scales. Modeling the weighting coefficients as independent stochastic processes leads to similar load characteristics as in the case of the truncated POD. To complete this simplified wake description, we show evidence that the small-scale dynamics can be captured by adding to our model a homogeneous turbulent field. In this way, we present a procedure to derive stochastic wake models from costly computational fluid dynamics (CFD calculations or elaborated experimental investigations. These numerically efficient models provide the added value of possible long-term studies. Depending on the aspects of interest, different minimalized models may be obtained.

Transient Resistive Wall Wake for Very Short Bunches

International Nuclear Information System (INIS)

Stupakov, G.; SLAC

2005-01-01

The catch up distance for the resistive wall wake in a round pipe is approximately equal to the square of the pipe radius divided by the bunch length. The standard formulae for this wake are applicable at distances much larger than the catch up distance. In this paper, we calculate the resistive wall wake at distances compared with the catch up distance assuming a constant wall conductivity

Three-dimensional structure of wind turbine wakes as measured by scanning lidar

Science.gov (United States)

Bodini, Nicola; Zardi, Dino; Lundquist, Julie K.

2017-08-01

The lower wind speeds and increased turbulence that are characteristic of turbine wakes have considerable consequences on large wind farms: turbines located downwind generate less power and experience increased turbulent loads. The structures of wakes and their downwind impacts are sensitive to wind speed and atmospheric variability. Wake characterization can provide important insights for turbine layout optimization in view of decreasing the cost of wind energy. The CWEX-13 field campaign, which took place between June and September 2013 in a wind farm in Iowa, was designed to explore the interaction of multiple wakes in a range of atmospheric stability conditions. Based on lidar wind measurements, we extend, present, and apply a quantitative algorithm to assess wake parameters such as the velocity deficits, the size of the wake boundaries, and the location of the wake centerlines. We focus on wakes from a row of four turbines at the leading edge of the wind farm to explore variations between wakes from the edge of the row (outer wakes) and those from turbines in the center of the row (inner wakes). Using multiple horizontal scans at different elevations, a three-dimensional structure of wakes from the row of turbines can be created. Wakes erode very quickly during unstable conditions and can in fact be detected primarily in stable conditions in the conditions measured here. During stable conditions, important differences emerge between the wakes of inner turbines and the wakes of outer turbines. Further, the strong wind veer associated with stable conditions results in a stretching of the wake structures, and this stretching manifests differently for inner and outer wakes. These insights can be incorporated into low-order wake models for wind farm layout optimization or for wind power forecasting.

Reviews/Essays: School Start Times and the Sleep-Wake Cycle of Adolescents--A Review and Critical Evaluation of Available Evidence

Science.gov (United States)

Kirby, Matthew; Maggi, Stefania; D'Angiulli, Amedeo

2011-01-01

The authors have integrated the major findings on the sleep-wake cycle and its performance correlates in adolescents. Basic research shows that lack of synchronicity between early school start times and the circadian rhythm of adolescents (and the sleep debt accumulated as a result) involves several cognitive correlates that may harm the academic…

Bifurcation and instability problems in vortex wakes

DEFF Research Database (Denmark)

Aref, Hassan; Brøns, Morten; Stremler, Mark A.

2007-01-01

A number of instability and bifurcation problems related to the dynamics of vortex wake flows are addressed using various analytical tools and approaches. We discuss the bifurcations of the streamline pattern behind a bluff body as a vortex wake is produced, a theory of the universal Strouhal......-Reynolds number relation for vortex wakes, the bifurcation diagram for "exotic" wake patterns behind an oscillating cylinder first determined experimentally by Williamson & Roshko, and the bifurcations in topology of the streamlines pattern in point vortex streets. The Hamiltonian dynamics of point vortices...... in a periodic strip is considered. The classical results of von Kármán concerning the structure of the vortex street follow from the two-vortices-in-a-strip problem, while the stability results follow largely from a four-vortices-in-a-strip analysis. The three-vortices-in-a-strip problem is argued...

Brief wakeful resting can eliminate directed forgetting.

Science.gov (United States)

Schlichting, Andreas; Bäuml, Karl-Heinz T

2017-02-01

When cued to intentionally forget previously encoded memories, participants typically show reduced recall of the memories on a later recall test. We examined how such directed forgetting is affected by a brief period of wakeful resting between encoding and test. Encoding was followed by a "passive" wakeful resting period in which subjects heard emotionally neutral music or perceived neutral pictures, or it was followed by an "active" distraction period in which subjects were engaged in counting or calculation tasks. Whereas typical directed forgetting was present after active distraction, the forgetting was absent after wakeful resting. The findings indicate that the degree to which people can intentionally forget memories is influenced by the cognitive activity that people engage in shortly after learning takes place. The results provide first evidence on the interplay between wakeful resting and intentional forgetting.

Sleep-wake disturbances after traumatic brain injury.

Science.gov (United States)

Ouellet, Marie-Christine; Beaulieu-Bonneau, Simon; Morin, Charles M

2015-07-01

Sleep-wake disturbances are extremely common after a traumatic brain injury (TBI). The most common disturbances are insomnia (difficulties falling or staying asleep), increased sleep need, and excessive daytime sleepiness that can be due to the TBI or other sleep disorders associated with TBI, such as sleep-related breathing disorder or post-traumatic hypersomnia. Sleep-wake disturbances can have a major effect on functional outcomes and on the recovery process after TBI. These negative effects can exacerbate other common sequelae of TBI-such as fatigue, pain, cognitive impairments, and psychological disorders (eg, depression and anxiety). Sleep-wake disturbances associated with TBI warrant treatment. Although evidence specific to patients with TBI is still scarce, cognitive-behavioural therapy and medication could prove helpful to alleviate sleep-wake disturbances in patients with a TBI. Copyright © 2015 Elsevier Ltd. All rights reserved.

Circadian Sleep-Wake Rhythm of Older Adults with Intellectual Disabilities

Science.gov (United States)

Maaskant, Marijke; van de Wouw, Ellen; van Wijck, Ruud; Evenhuis, Heleen M.; Echteld, Michael A.

2013-01-01

The circadian sleep-wake rhythm changes with aging, resulting in a more fragmented sleep-wake pattern. In individuals with intellectual disabilities (ID), brain structures regulating the sleep-wake rhythm might be affected. The aims of this study were to compare the sleep-wake rhythm of older adults with ID to that of older adults in the general…

Restructuring a basic science course for core competencies: an example from anatomy teaching.

Science.gov (United States)

Gregory, Jeremy K; Lachman, Nirusha; Camp, Christopher L; Chen, Laura P; Pawlina, Wojciech

2009-09-01

Medical schools revise their curricula in order to develop physicians best skilled to serve the public's needs. To ensure a smooth transition to residency programs, undergraduate medical education is often driven by the six core competencies endorsed by the Accreditation Council for Graduate Medical Education (ACGME): patient care, medical knowledge, practice-based learning, interpersonal skills, professionalism, and systems-based practice. Recent curricular redesign at Mayo Medical School provided an opportunity to restructure anatomy education and integrate radiology with first-year gross and developmental anatomy. The resulting 6-week (120-contact-hour) human structure block provides students with opportunities to learn gross anatomy through dissection, radiologic imaging, and embryologic correlation. We report more than 20 educational interventions from the human structure block that may serve as a model for incorporating the ACGME core competencies into basic science and early medical education. The block emphasizes clinically-oriented anatomy, invites self- and peer-evaluation, provides daily formative feedback through an audience response system, and employs team-based learning. The course includes didactic briefing sessions and roles for students as teachers, leaders, and collaborators. Third-year medical students serve as teaching assistants. With its clinical focus and competency-based design, the human structure block connects basic science with best-practice clinical medicine.

Linearised CFD Models for Wakes

DEFF Research Database (Denmark)

Ott, Søren; Berg, Jacob; Nielsen, Morten

This report describes the development of a fast and reasonably accurate model for the prediction of energy production in oshore wind farms taking wake eects into account. The model has been implemented as a windows application called Fuga which can run in batch mode or as a graphical user interface....... Fuga is brie y described. The model is based on alinearization technique which is described in some detail, and linearized, governing equations are derived and written in a standard form based on a mixed{spectral formulation. A new solution method is used to solve the equations which involves intensive...... use of look{up tables for storage of intermediate results. Due to the linearity of the model, multiple wakes from many turbines can be constructed from the wake of a single, solitary turbine. These are in turn constructed from Fourier components by a fast Fourier integral transform of results derived...

Translating Basic Behavioral and Social Science Research to Clinical Application: The EVOLVE Mixed Methods Approach

Science.gov (United States)

Peterson, Janey C.; Czajkowski, Susan; Charlson, Mary E.; Link, Alissa R.; Wells, Martin T.; Isen, Alice M.; Mancuso, Carol A.; Allegrante, John P.; Boutin-Foster, Carla; Ogedegbe, Gbenga; Jobe, Jared B.

2013-01-01

Objective: To describe a mixed-methods approach to develop and test a basic behavioral science-informed intervention to motivate behavior change in 3 high-risk clinical populations. Our theoretically derived intervention comprised a combination of positive affect and self-affirmation (PA/SA), which we applied to 3 clinical chronic disease…

Projects for the implementation of science technology society approach in basic concept of natural science course as application of optical and electrical instruments’ material

Science.gov (United States)

Satria, E.

2018-03-01

Preservice teachers in primary education should be well equipped to meet the challenges of teaching primary science effectively in 21century. The purpose of this research was to describe the projects for the implementation of Science-Technology-Society (STS) approach in Basic Concept of Natural Science course as application of optical and electrical instruments’ material by the preservice teachers in Elementary Schools Teacher Education Program. One of the reasons is the lack of preservice teachers’ ability in making projects for application of STS approach and optical and electrical instruments’ material in Basic Concept of Natural Science course. This research applied descriptive method. The instrument of the research was the researcher himself. The data were gathered through observation and documentation. Based on the results of the research, it was figured out that preservice teachers, in groups, were creatively and successful to make the projects of optical and electrical instruments assigned such as projector and doorbell. It was suggested that the construction of the instruments should be better (fixed and strong structure) and more attractive for both instruments, and used strong light source, high quality images, and it could use speaker box for projector, power battery, and heat sink for electrical instruments.

Detecting wind turbine wakes with nacelle lidars

DEFF Research Database (Denmark)

Held, D. P.; Larvol, A.; Mann, Jakob

2017-01-01

variance is used as a detection parameter for wakes. A one month long measurement campaign, where a continuous-wave lidar on a turbine has been exposed to multiple wake situations, is used to test the detection capabilities. The results show that it is possible to identify situation where a downstream...... turbine is in wake by comparing the peak widths. The used lidar is inexpensive and brings instalments on every turbine within economical reach. Thus, the information gathered by the lidars can be used for improved control at wind farm level....

The Case of the Neutron Star With a Wayward Wake

Science.gov (United States)

2006-06-01

A long observation with NASA's Chandra X-ray Observatory has revealed important new details of a neutron star that is spewing out a wake of high-energy particles as it races through space. The deduced location of the neutron star on the edge of a supernova remnant, and the peculiar orientation of the neutron star wake, pose mysteries that remain unresolved. "Like a kite flying in the wind, the behavior of this neutron star and its wake tell us what sort of gas it must be plowing through," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and lead author of a paper accepted to The Astrophysical Journal. "Yet we're still not sure how the neutron star got to its present location." Animation: Sequence of images of J0617 in IC 443 Animation: Sequence of images of J0617 in IC 443 The neutron star, known as CXOU J061705.3+222127, or J0617 for short, appears to lie near the outer edge of an expanding bubble of hot gas associated with the supernova remnant IC 443. Presumably, J0617 was created at the time of the supernova -- approximately 30,000 years ago -- and propelled away from the site of the explosion at about 500,000 miles per hour. However, the neutron star's wake is oriented almost perpendicularly to the direction expected if the neutron star were moving away from the center of the supernova remnant. This apparent misalignment had previously raised doubts about the association of the speeding neutron star with the supernova remnant. Gaensler and his colleagues provide strong evidence that J0617 was indeed born in the same explosion that created the supernova remnant. First, the shape of the neutron star's wake indicates it is moving a little faster than the speed of sound in Composite Images of SNR IC 443 Composite Images of SNR IC 443 the remnant's multimillion-degree gas. The velocity that one can then calculate from this conclusion closely matches the predicted pace of the neutron star. In contrast, if the neutron

International Survey on the Management of Wake-Up Stroke.

Science.gov (United States)

de Castro-Afonso, Luís Henrique; Nakiri, Guilherme Seizem; Pontes-Neto, Octávio Marques; dos Santos, Antônio Carlos; Abud, Daniel Giansante

2016-01-01

Patients who wake up having experienced a stroke while asleep represent around 20% of acute stroke admissions. According to international guidelines for the management of acute stroke, patients presenting with wake-up stroke are not currently eligible to receive revascularization treatments. In this study, we aimed to assess the opinions of stroke experts about the management of patients with wake-up stroke by using an international multicenter electronic survey. This study consisted of 8 questions on wake-up stroke treatment. Two hundred invitations to participate in the survey were sent by e-mail. Fifty-nine participants started the survey, 4 dropped out before completing it, and 55 completed the full questionnaire. We had 55 participants from 22 countries. In this study, most stroke experts recommended a recanalization treatment for wake-up stroke. However, there was considerable disagreement among experts regarding the best brain imaging method and the best recanalization treatment. The results of ongoing randomized trials on wake-up stroke are urgently needed.

Forecasting behavior in smart homes based on sleep and wake patterns.

Science.gov (United States)

Williams, Jennifer A; Cook, Diane J

2017-01-01

The goal of this research is to use smart home technology to assist people who are recovering from injuries or coping with disabilities to live independently. We introduce an algorithm to model and forecast wake and sleep behaviors that are exhibited by the participant. Furthermore, we propose that sleep behavior is impacted by and can be modeled from wake behavior, and vice versa. This paper describes the Behavior Forecasting (BF) algorithm. BF consists of 1) defining numeric values that reflect sleep and wake behavior, 2) forecasting wake and sleep values from past behavior, 3) analyzing the effect of wake behavior on sleep and vice versa, and 4) improving prediction performance by using both wake and sleep scores. The BF method was evaluated with data collected from 20 smart homes. We found that regardless of the forecasting method utilized, wake behavior and sleep behavior can be modeled with a minimum accuracy of 84%. Additionally, normalizing the wake and sleep scores drastically improves the accuracy to 99%. The results show that we can effectively model wake and sleep behaviors in a smart environment. Furthermore, wake behaviors can be predicted from sleep behaviors and vice versa.

Numerical challenges of short range wake field calculations

Energy Technology Data Exchange (ETDEWEB)

Lau, Thomas; Gjonaj, Erion; Weiland, Thomas [Technische Universitaet Darmstadt (Germany). Institut fuer Theorie Elektromagnetischer Felder (TEMF)

2011-07-01

For present and future accelerator projects with ultra short bunches the accurate and reliable calculation of short range wake fields is an important issue. However, the numerical calculation of short range wake fields is a numerical challenging task. The presentation gives an overview over the numerical challenges and techniques for short range wake field calculations. Finally, some simulation results obtained by the program PBCI developed at the TU Darmstadt are presented.

Regional and Interregional Cooperation to Strengthen Basic Sciences in Developing Countries : Addis Ababa, 1-4 September 2009

OpenAIRE

2011-01-01

The International Science Programme (ISP) at Uppsala University, Sweden, is devoted to long-term support to institutional capacity building in research and higher education in developing countries, with focus on the basic sciences: physics (since 1961), chemistry (since 1970), and mathematics (since 2002). Both research groups and scientific network activities are supported. Interdisciplinary and applied research is important in solving a number of challenges facing the world today. Problems ...

Velocity field in the wake of a hydropower farm equipped with Achard turbines

International Nuclear Information System (INIS)

Georgescu, A-M; Cosoiu, C I; Alboiu, N; Hamzu, Al; Georgescu, S C

2010-01-01

The study consists of experimental and numerical investigations related to the water flow in the wake of a hydropower farm, equipped with three Achard turbines. The Achard turbine is a French concept of vertical axis cross-flow marine current turbine, with three vertical delta-blades, which operates irrespective of the water flow direction. A farm model built at 1:5 scale has been tested in a water channel. The Achard turbines run in stabilized current, so the flow can be assumed to be almost unchanged in horizontal planes along the vertical z-axis, thus allowing 2D numerical modelling, for different farm configurations: the computational domain is a cross-section of all turbines at a certain z-level. The two-dimensional numerical model of that farm has been used to depict the velocity field in the wake of the farm, with COMSOL Multiphysics and FLUENT software, to compute numerically the overall farm efficiency. The validation of the numerical models with experimental results is performed via the measurement of velocity distribution, by Acoustic Doppler Velocimetry, in the wake of the middle turbine within the farm. Three basic configurations were studied experimentally and numerically, namely: with all turbines aligned on a row across the upstream flow direction; with turbines in an isosceles triangular arrangement pointing downstream; with turbines in an isosceles triangular arrangement pointing upstream. As long as the numerical flow in the wake fits the experiments, the numerical results for the power coefficient (turbine efficiency) are trustworthy. The farm configuration with all turbines aligned on a same row leads to lower values of the experimental velocities than the numerical ones, while the farm configurations where the turbines are in isosceles triangular arrangement, pointing downstream or upstream, present a better match between numerical and experimental data.

Tomo-PIV measurements of the flow field in the wake of a sphere

Science.gov (United States)

Eshbal, Lior; David, Tom; Rinsky, Vladislav; van Hout, Rene; Greenblatt, David

2017-11-01

A sphere can be considered as a prototypical 3D bluff body. In order to improve our understanding of its 3D wake flow, a combination of time-resolved planar particle image velocimetry (PIV) and tomographic PIV (tomo-PIV) was implemented. Experiments were performed in a closed-loop water channel facility and sphere Reynolds numbers ReD = UD/ ν = 400, 800, 1200 and 2000, where U is the free-stream velocity, ν the kinematic viscosity and D the sphere diameter. The measurement volume (Height x Length x Width, 5 x 5 x 1.5 D3) comprised the sphere and the downstream wake. Tomo-PIV snap-shots were correlated with the time-resolved PIV such that the 3D temporal evolution of the shed vortices became clear. At ReD = 400, this procedure revealed shed hairpin vortices having a vertical plane of symmetry in agreement with many dye visualization studies. However, the measurements also revealed weaker induced hairpins resulting from the interaction of the near-wake flow and the surrounding free stream. These induced vortices were not visible in previous dye and smoke visualizations and have only been observed in simulations. Data processing of the data at higher ReD is currently ongoing. Israel Science Foundation Grant No. 1596/14.

A Hybrid Model of Mathematics Support for Science Students Emphasizing Basic Skills and Discipline Relevance

Science.gov (United States)

Jackson, Deborah C.; Johnson, Elizabeth D.

2013-01-01

The problem of students entering university lacking basic mathematical skills is a critical issue in the Australian higher-education sector and relevant globally. The Maths Skills programme at La Trobe University has been developed to address under preparation in the first-year science cohort in the absence of an institutional mathematics support…

Actuator Line Modeling of Wind Turbine Wakes

DEFF Research Database (Denmark)

Troldborg, Niels

2009-01-01

This thesis contains a comprehensive 3D Navier-Stokes computational study of the characteristics of wakes of wind turbines operating in various flow conditions including interacting wakes between a row of turbines. The computations were carried out using the actuator line technique combined...

Wake-Model Effects on Induced Drag Prediction of Staggered Boxwings

Directory of Open Access Journals (Sweden)

Julian Schirra

2018-01-01

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.

Optimization Under Uncertainty for Wake Steering Strategies: Preprint

Energy Technology Data Exchange (ETDEWEB)

Quick, Julian [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Annoni, Jennifer [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ryan N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fleming, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ning, Andrew [Brigham Young University

2017-05-01

Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence of yaw angle uncertainty. The OUU wake steering strategy is demonstrated on a two-turbine test case and on the utility-scale, offshore Princess Amalia Wind Farm. When we accounted for yaw angle uncertainty in the Princess Amalia Wind Farm case, inflow-direction-specific OUU solutions produced between 0% and 1.4% more power than the deterministically optimized steering strategies, resulting in an overall annual average improvement of 0.2%. More importantly, the deterministic optimization is expected to perform worse and with more downside risk than the OUU result when realistic uncertainty is taken into account. Additionally, the OUU solution produces fewer extreme yaw situations than the deterministic solution.

Uncovering the genetic landscape for multiple sleep-wake traits.

Directory of Open Access Journals (Sweden)

Christopher J Winrow

Full Text Available Despite decades of research in defining sleep-wake properties in mammals, little is known about the nature or identity of genes that regulate sleep, a fundamental behaviour that in humans occupies about one-third of the entire lifespan. While genome-wide association studies in humans and quantitative trait loci (QTL analyses in mice have identified candidate genes for an increasing number of complex traits and genetic diseases, the resources and time-consuming process necessary for obtaining detailed quantitative data have made sleep seemingly intractable to similar large-scale genomic approaches. Here we describe analysis of 20 sleep-wake traits from 269 mice from a genetically segregating population that reveals 52 significant QTL representing a minimum of 20 genomic loci. While many (28 QTL affected a particular sleep-wake trait (e.g., amount of wake across the full 24-hr day, other loci only affected a trait in the light or dark period while some loci had opposite effects on the trait during the light vs. dark. Analysis of a dataset for multiple sleep-wake traits led to previously undetected interactions (including the differential genetic control of number and duration of REM bouts, as well as possible shared genetic regulatory mechanisms for seemingly different unrelated sleep-wake traits (e.g., number of arousals and REM latency. Construction of a Bayesian network for sleep-wake traits and loci led to the identification of sub-networks of linkage not detectable in smaller data sets or limited single-trait analyses. For example, the network analyses revealed a novel chain of causal relationships between the chromosome 17@29cM QTL, total amount of wake, and duration of wake bouts in both light and dark periods that implies a mechanism whereby overall sleep need, mediated by this locus, in turn determines the length of each wake bout. Taken together, the present results reveal a complex genetic landscape underlying multiple sleep-wake traits

Wind turbine wake characterization using long-range Doppler lidar

Science.gov (United States)

Aitken, M.; Lundquist, J. K.; Hestmark, K.; Banta, R. M.; Pichugina, Y.; Brewer, A.

2012-12-01

Wind turbines extract energy from the freestream flow, resulting in a waked region behind the rotor which is characterized by reduced wind speed and increased turbulence. The velocity deficit in the wake diminishes with distance, as faster-moving air outside is gradually entrained. In a concentrated group of turbines, then, downwind machines experience very different inflow conditions compared to those in the front row. As utility-scale turbines rarely exist in isolation, detailed knowledge of the mean flow and turbulence structure inside wakes is needed to correctly model both power production and turbine loading at modern wind farms. To this end, the Turbine Wake and Inflow Characterization Study (TWICS) was conducted in the spring of 2011 to determine the reduction in wind speeds downstream from a multi-MW turbine located at the National Renewable Energy Laboratory's National Wind Technology Center (NWTC) near Boulder, Colorado. Full-scale measurements of wake dynamics are hardly practical or even possible with conventional sensors, such as cup anemometers mounted on meteorological (met) masts. Accordingly, the High Resolution Doppler Lidar (HRDL) developed by the National Oceanic and Atmospheric Administration's Earth System Research Laboratory was employed to investigate the formation and propagation of wakes under varying levels of ambient wind speed, shear, atmospheric stability, and turbulence. HRDL remotely senses line-of-sight wind velocities and has been used in several previous studies of boundary layer aerodynamics. With a fully steerable beam and a maximum range up to about 5 km, depending on atmospheric conditions, HRDL performed a comprehensive survey of the wind flow in front of and behind the turbine to study the shape, meandering, and attenuation of wakes. Due in large part to limited experimental data availability, wind farm wake modeling is still subject to an unacceptable amount of uncertainty, particularly in complex terrain. Here, analytical

VIRTUAL REALITY IN WAKING AND DREAMING CONSCIOUSNESS

Directory of Open Access Journals (Sweden)

Allan eHobson

2014-10-01

Full Text Available This article explores the notion that the brain is genetically endowed with an innate virtual reality generator that – through experience-dependent plasticity –becomes a generative or predictive model of the world. This model, which is most clearly revealed in rapid eye movement (REM sleep dreaming, may provide the theatre for conscious experience. Functional neuroimaging evidence for brain activations that are time-locked to rapid eye movements endorses the view that waking consciousness emerges from REM sleep – and dreaming lays the foundations for waking perception. In this view, the brain is equipped with a virtual model of the world that generates predictions of its sensations. This model is continually updated and entrained by sensory prediction errors in wakefulness to ensure veridical perception, but not in dreaming. In contrast, dreaming plays an essential role in maintaining and enhancing the capacity to model the world by minimizing model complexity and thereby maximizing both statistical and thermodynamic efficiency. This perspective suggests that consciousness corresponds to the embodied process of inference, realized through the generation of virtual realities (in both sleep and wakefulness. In short, our premise or hypothesis is that the waking brain engages with the sensorium to predict the causes of sensations, while in sleep the brain's generative model is actively refined so that it generates more efficient predictions during waking. We review the evidence in support of this hypothesis – evidence that grounds consciousness in biophysical computations whose neuronal and neurochemical infrastructure has been disclosed by sleep research.

Generalized impedances and wakes in asymmetric structures

International Nuclear Information System (INIS)

Heifets, S.; Wagner, A.; Zotter, B.

1998-01-01

In rotationally structures, the dominant m = 0 longitudinal impedance does not depend on the offsets of either the leading or the trailing particles, while the dominant m = 1 transverse impedance is proportional to the offset of the leading particles, while it is still independent of the offsets of the trailing ones. This behavior is no longer true in rotationally non-symmetric structures, where in general all impedances depend on the offsets of both the leading and the trailing particles. The same behavior is shown by wake functions and wake potentials. The concept of generalized impedances or generalized wake functions must be used to calculate the effect of leading particles on trailing ones with different offsets, each described by two transverse coordinates. This dependence of wake potentials on four additional parameters (two for each offset) would make their use very cumbersome. Fortunately, it was found that the transverse wake potentials can be separated into superpositions of dipolar components, which are proportional to the offset of the leading bunch, and quadrupolar components, which are proportional to the offset of the trailing particles. Higher multipole components are much smaller, and can be neglected for most structures without rotational symmetry. In this report, the authors derive analytical expressions for these multipolar components, which permits estimates of the size of the neglected terms. In particular, when structures have one or two transverse symmetry planes, the expressions simplify and explain the behavior of wake potentials which had been computed for rotationally non-symmetric structures

Conformal FDTD modeling wake fields

Energy Technology Data Exchange (ETDEWEB)

Jurgens, T.; Harfoush, F.

1991-05-01

Many computer codes have been written to model wake fields. Here we describe the use of the Conformal Finite Difference Time Domain (CFDTD) method to model the wake fields generated by a rigid beam traveling through various accelerating structures. The non- cylindrical symmetry of some of the problems considered here requires the use of a three dimensional code. In traditional FDTD codes, curved surfaces are approximated by rectangular steps. The errors introduced in wake field calculations by such an approximation can be reduced by increasing the mesh size, therefore increasing the cost of computing. Another approach, validated here, deforms Ampere and Faraday contours near a media interface so as to conform to the interface. These improvements of the FDTD method result in better accuracy of the fields at asymptotically no computational cost. This method is also capable of modeling thin wires as found in beam profile monitors, and slots and cracks as found in resistive wall motions. 4 refs., 5 figs.

Forecasting Behavior in Smart Homes Based on Sleep and Wake Patterns

Science.gov (United States)

Williams, Jennifer A.; Cook, Diane J.

2017-01-01

Background The goal of this research is to use smart home technology to assist people who are recovering from injuries or coping with disabilities to live independently. Objective We introduce an algorithm to model and forecast wake and sleep behaviors that are exhibited by the participant. Furthermore, we propose that sleep behavior is impacted by and can be modeled from wake behavior, and vice versa. Methods This paper describes the Behavior Forecasting (BF) algorithm. BF consists of 1) defining numeric values that reflect sleep and wake behavior, 2) forecasting wake and sleep values from past behavior, 3) analyzing the effect of wake behavior on sleep and vice versa, and 4) improving prediction performance by using both wake and sleep scores. Results The BF method was evaluated with data collected from 20 smart homes. We found that regardless of the forecasting method utilized, wake behavior and sleep behavior can be modeled with a minimum accuracy of 84%. Additionally, normalizing the wake and sleep scores drastically improves the accuracy to 99%. Conclusions The results show that we can effectively model wake and sleep behaviors in a smart environment. Furthermore, wake behaviors can be predicted from sleep behaviors and vice versa. PMID:27689555

Basic Electromagnetism and Materials

CERN Document Server

Moliton, André

2007-01-01

Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

Basics of laser physics for students of science and engineering

CERN Document Server

Renk, Karl F

2017-01-01

This textbook provides an introductory presentation of all types of lasers. It contains a general description of the laser, a theoretical treatment and a characterization of its operation as it deals with gas, solid state, free-electron and semiconductor lasers. This expanded and updated second edition of the book presents a description of the dynamics of free-electron laser oscillation using a model introduced in the first edition that allows a reader to understand basic properties of a free-electron laser and makes the difference to “conventional” lasers. The discussions and the treatment of equations are presented in a way that a reader can immediately follow. The book addresses graduate and undergraduate students in science and engineering, featuring problems with solutions and over 400 illustrations.

Dynamic Loads and Wake Prediction for Large Wind Turbines Based on Free Wake Method

Institute of Scientific and Technical Information of China (English)

Cao Jiufa; Wang Tongguang; Long Hui; Ke Shitang; Xu Bofeng

2015-01-01

With large scale wind turbines ,the issue of aerodynamic elastic response is even more significant on dy-namic behaviour of the system .Unsteady free vortex wake method is proposed to calculate the shape of wake and aerodynamic load .Considering the effect of aerodynamic load ,inertial load and gravity load ,the decoupling dy-namic equations are established by using finite element method in conjunction of the modal method and equations are solved numerically by Newmark approach .Finally ,the numerical simulation of a large scale wind turbine is performed through coupling the free vortex wake modelling with structural modelling .The results show that this coupling model can predict the flexible wind turbine dynamic characteristics effectively and efficiently .Under the influence of the gravitational force ,the dynamic response of flapwise direction contributes to the dynamic behavior of edgewise direction under the operational condition of steady wind speed .The difference in dynamic response be-tween the flexible and rigid wind turbines manifests when the aerodynamics/structure coupling effect is of signifi-cance in both wind turbine design and performance calculation .

International Survey on the Management of Wake-Up Stroke

Directory of Open Access Journals (Sweden)

Luís Henrique de Castro-Afonso

2016-03-01

Full Text Available Background: Patients who wake up having experienced a stroke while asleep represent around 20% of acute stroke admissions. According to international guidelines for the management of acute stroke, patients presenting with wake-up stroke are not currently eligible to receive revascularization treatments. In this study, we aimed to assess the opinions of stroke experts about the management of patients with wake-up stroke by using an international multicenter electronic survey. Method: This study consisted of 8 questions on wake-up stroke treatment. Results: Two hundred invitations to participate in the survey were sent by e-mail. Fifty-nine participants started the survey, 4 dropped out before completing it, and 55 completed the full questionnaire. We had 55 participants from 22 countries. Conclusions: In this study, most stroke experts recommended a recanalization treatment for wake-up stroke. However, there was considerable disagreement among experts regarding the best brain imaging method and the best recanalization treatment. The results of ongoing randomized trials on wake-up stroke are urgently needed.

Functional anatomy of the sleep-wakefulness cycle: wakefulness.

Science.gov (United States)

Reinoso-Suárez, Fernando; de Andrés, Isabel; Garzón, Miguel

2011-01-01

Sleep is a necessary, diverse, periodic, and an active condition circadian and homeostatically regulated and precisely meshed with waking time into the sleep-wakefulness cycle (SWC). Photic retinal stimulation modulates the suprachiasmatic nucleus, which acts as the pacemaker for SWC rhythmicity. Both the light period and social cues adjust the internal clock, making the SWC a circadian, 24-h period in the adult human. Bioelectrical and behavioral parameters characterize the different phases of the SWC. For a long time, lesions and electrical stimulation of brain structures, as well as connection studies, were the main methods used to decipher the foundations of the functional anatomy of the SWC. That is why the first section of this review presents these early historical studies to then discuss the current state of our knowledge based on our understanding of the functional anatomy of the structures underlying the SWC. Supported by this description, we then present a detailed review and update of the structures involved in the phase of wakefulness (W), including their morphological, functional, and chemical characteristics, as well as their anatomical connections. The structures for W generation are known as the "ascending reticular activating system", and they keep and maintain the "thalamo-cerebral cortex unit" awake. This system originates from the neuronal groups located within the brainstem, hypothalamus, and basal forebrain, which use known neurotransmitters and whose neurons are more active during W than during the other SWC states. Thus, synergies among several of these neurotransmitters are necessary to generate the cortical and thalamic activation that is characteristic of the W state, with all the plastic qualities and nuances present in its different behavioral circumstances. Each one of the neurotransmitters exerts powerful influences on the information and cognitive processes as well as attentional, emotional, motivational, behavioral, and arousal

Wake field in matched kicker magnet

International Nuclear Information System (INIS)

Miyahara, Y.

1979-01-01

Coherent transverse instability observed in KEK booster proton synchrotron has been reported previously. This instability is induced by the interaction of the beam with kicker magnet for the fast beam extraction. To understand the mechanism completely, it is necessary to know the wake field in detail. Here, the wake field or induced current in the kicker magnet which is terminated with matched resistance is considered

Wind turbine wake in atmospheric turbulence

Energy Technology Data Exchange (ETDEWEB)

Rethore, P -E

2009-10-15

This thesis describes the different steps needed to design a steady-state computational fluid dynamics (CFD) wind farm wake model. The ultimate goal of the project was to design a tool that could analyze and extrapolate systematically wind farm measurements to generate wind maps in order to calibrate faster and simpler engineering wind farm wake models. The most attractive solution was the actuator disc method with the steady state k-epsilon turbulence model. The first step to design such a tool is the treatment of the forces. This thesis presents a computationally inexpensive method to apply discrete body forces into the finite-volume flow solver with collocated variable treatment (EllipSys), which avoids the pressure-velocity decoupling issue. The second step is to distribute the body forces in the computational domain accordingly to rotor loading. This thesis presents a generic flexible method that associates any kind of shapes with the computational domain discretization. The special case of the actuator disc performs remarkably well in comparison with Conway's heavily loaded actuator disc analytical solution and a CFD full rotor computation, even with a coarse discretization. The third step is to model the atmospheric turbulence. The standard k-epsilon model is found to be unable to model at the same time the atmospheric turbulence and the actuator disc wake and performs badly in comparison with single wind turbine wake measurements. A comparison with a Large Eddy Simulation (LES) shows that the problem mainly comes from the assumptions of the eddy-viscosity concept, which are deeply invalidated in the wind turbine wake region. Different models that intent to correct the k-epsilon model's issues are investigated, of which none of them is found to be adequate. The mixing of the wake in the atmosphere is a deeply non-local phenomenon that is not handled correctly by an eddy-viscosity model such as k-epsilon. (author)

Wind turbine wake in atmospheric turbulence

Energy Technology Data Exchange (ETDEWEB)

Rethore, P.-E.

2009-10-15

This thesis describes the different steps needed to design a steady-state computational fluid dynamics (CFD) wind farm wake model. The ultimate goal of the project was to design a tool that could analyze and extrapolate systematically wind farm measurements to generate wind maps in order to calibrate faster and simpler engineering wind farm wake models. The most attractive solution was the actuator disc method with the steady state k-epsilon turbulence model. The first step to design such a tool is the treatment of the forces. This thesis presents a computationally inexpensive method to apply discrete body forces into the finite-volume flow solver with collocated variable treatment (EllipSys), which avoids the pressure-velocity decoupling issue. The second step is to distribute the body forces in the computational domain accordingly to rotor loading. This thesis presents a generic flexible method that associates any kind of shapes with the computational domain discretization. The special case of the actuator disc performs remarkably well in comparison with Conway's heavily loaded actuator disc analytical solution and a CFD full rotor computation, even with a coarse discretization. The third step is to model the atmospheric turbulence. The standard k-epsilon model is found to be unable to model at the same time the atmospheric turbulence and the actuator disc wake and performs badly in comparison with single wind turbine wake measurements. A comparison with a Large Eddy Simulation (LES) shows that the problem mainly comes from the assumptions of the eddy-viscosity concept, which are deeply invalidated in the wind turbine wake region. Different models that intent to correct the k-epsilon model's issues are investigated, of which none of them is found to be adequate. The mixing of the wake in the atmosphere is a deeply non-local phenomenon that is not handled correctly by an eddy-viscosity model such as k-epsilon. (author)

Basic research projects

International Nuclear Information System (INIS)

1979-04-01

The research programs under the cognizance of the Office of Energy Research (OER) are directed toward discovery of natural laws and new knowledge, and to improved understanding of the physical and biological sciences as related to the development, use, and control of energy. The ultimate goal is to develop a scientific underlay for the overall DOE effort and the fundamental principles of natural phenomena so that these phenomena may be understood, and new principles, formulated. The DOE-OER outlay activities include three major programs: High Energy Physics, Nuclear Physics, and Basic Energy Sciences. Taken together, these programs represent some 30 percent of the Nation's Federal support of basic research in the energy sciences. The research activities of OER involve more than 6,000 scientists and engineers working in some 17 major Federal Research Centers and at more than 135 different universities and industrial firms throughout the United States. Contract holders in the areas of high-energy physics, nuclear physics, materials sciences, nuclear science, chemical sciences, engineering, mathematics geosciences, advanced energy projects, and biological energy research are listed. Funding trends for recent years are outlined

Wake-based ship route estimation in high-resolution SAR images

Science.gov (United States)

Graziano, M. Daniela; Rufino, Giancarlo; D'Errico, Marco

2014-10-01

This paper presents a novel algorithm for wake detection in Synthetic Aperture Radar images of the sea. The algorithm has been conceived as part of a ship traffic monitoring system, in charge of ship detection validation and to estimate ship route features, such as heading and ground speed. In addition, it has been intended to be adequate for inclusion in an automatic procedure without human operator supervision. The algorithm exploits the Radon transform to identify the images ship wake on the basis of the well known theoretical characteristics of the wakes' geometry and components, that are the turbulent wake, the narrow-V wakes, and the Kelvin arms, as well as the typical appearance of such components in Synthetic Aperture Radar images of the sea as bright or dark linear feature. Examples of application to high-resolution X-band Synthetic Aperture Radar products (COSMOSkymed and TerraSAR-X) are reported, both for wake detection and ship route estimation, showing the achieved quality and reliability of wake detection, adequacy to automatic procedures, as well as speed measure accuracy.

The Views of Science Pre-Service Teachers about the Usage of Basic Information Technologies (BIT) in Education and Instruction

Science.gov (United States)

Çetin, Oguz

2016-01-01

In this study aiming to present a description based on science pre-service teachers' views related to use of Basic Information Technologies (BIT) in education and training, an interview is carried out with 21 pre-service science teachers who study in different classes in Faculty of Education, Nigde University. For this aim, improved interview form…

Basic research needs to assure a secure energy future. A report from the Basic Energy Sciences Advisory Committee

Energy Technology Data Exchange (ETDEWEB)

None

2003-02-01

This report has highlighted many of the possible fundamental research areas that will help our country avoid a future energy crisis. The report may not have adequately captured the atmosphere of concern that permeated the discussions at the workshop. The difficulties facing our nation and the world in meeting our energy needs over the next several decades are very challenging. It was generally felt that traditional solutions and approaches will not solve the total energy problem. Knowledge that does not exist must be obtained to address both the quantity of energy needed to increase the standard of living world-wide and the quality of energy generation needed to preserve the environment. In terms of investments, it was clear that there is no single research area that will secure the future energy supply. A diverse range of economic energy sources will be required--and a broad range of fundamental research is needed to enable these. Many of the issues fall into the traditional materials and chemical sciences research areas, but with specific emphasis on understanding mechanisms, energy related phenomena, and pursuing novel directions in, for example, nanoscience and integrated modeling. An important result from the discussions, which is hopefully apparent from the brief presentations above, is that the problems that must be dealt with are truly multidisciplinary. This means that they require the participation of investigators with different skill sets. Basic science skills have to be complemented by awareness of the overall nature of the problem in a national and world context, and with knowledge of the engineering, design, and control issues in any eventual solution. It is necessary to find ways in which this can be done while still preserving the ability to do first-class basic science. The traditional structure of research, with specific disciplinary groupings, will not be sufficient. This presents great challenges and opportunities for the funders of the

On the Effects of Wind Turbine Wake Skew Caused by Wind Veer

Energy Technology Data Exchange (ETDEWEB)

Churchfield, Matthew J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-01-12

Because of Coriolis forces caused by the Earth's rotation, the structure of the atmospheric boundary layer often contains wind-direction change with height, also known as wind-direction veer. Under low turbulence conditions, such as in stably stratified atmospheric conditions, this veer can be significant, even across the vertical extent of a wind turbine's rotor disk. The veer then causes the wind turbine wake to skew as it advects downstream. This wake skew has been observed both experimentally and numerically. In this work, we attempt to examine the wake skewing process in some detail, and quantify how differently a skewed wake versus a non skewed wake affects a downstream turbine. We do this by performing atmospheric large-eddy simulations to create turbulent inflow winds with and without veer. In the veer case, there is a roughly 8 degree wind direction change across the turbine rotor. We then perform subsequent large-eddy simulations using these inflow data with an actuator line rotor model to create wakes. The turbine modeled is a large, modern, offshore, multimegawatt turbine. We examine the unsteady wake data in detail and show that the skewed wake recovers faster than the non skewed wake. We also show that the wake deficit does not skew to the same degree that a passive tracer would if subject to veered inflow. Last, we use the wake data to place a hypothetical turbine 9 rotor diameters downstream by running aeroelastic simulations with the simulated wake data. We see differences in power and loads if this downstream turbine is subject to a skewed or non skewed wake. We feel that the differences observed between the skewed and nonskewed wake are important enough that the skewing effect should be included in engineering wake models.

Sleep/wake dependent changes in cortical glucose concentrations.

Science.gov (United States)

Dash, Michael B; Bellesi, Michele; Tononi, Giulio; Cirelli, Chiara

2013-01-01

Most of the energy in the brain comes from glucose and supports glutamatergic activity. The firing rate of cortical glutamatergic neurons, as well as cortical extracellular glutamate levels, increase with time spent awake and decline throughout non rapid eye movement sleep, raising the question whether glucose levels reflect behavioral state and sleep/wake history. Here chronic (2-3 days) electroencephalographic recordings in the rat cerebral cortex were coupled with fixed-potential amperometry to monitor the extracellular concentration of glucose ([gluc]) on a second-by-second basis across the spontaneous sleep-wake cycle and in response to 3 h of sleep deprivation. [Gluc] progressively increased during non rapid eye movement sleep and declined during rapid eye movement sleep, while during wake an early decline in [gluc] was followed by an increase 8-15 min after awakening. There was a significant time of day effect during the dark phase, when rats are mostly awake, with [gluc] being significantly lower during the last 3-4 h of the night relative to the first 3-4 h. Moreover, the duration of the early phase of [gluc] decline during wake was longer after prolonged wake than after consolidated sleep. Thus, the sleep/wake history may affect the levels of glucose available to the brain upon awakening. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

A Mental Model of the Learner: Teaching the Basic Science of Educational Psychology to Future Teachers

Science.gov (United States)

Willingham, Daniel T.

2017-01-01

Although most teacher education programs include instruction in the basic science of psychology, practicing teachers report that this preparation has low utility. Researchers have considered what sort of information from psychology about children's thinking, emotion, and motivation would be useful for teachers' practice. Here, I take a different…

Rotor boundary layer development with inlet guide vane (IGV) wake impingement

Science.gov (United States)

Jia, Lichao; Zou, Tengda; Zhu, Yiding; Lee, Cunbiao

2018-04-01

This paper examines the transition process in a boundary layer on a rotor blade under the impingement of an inlet guide vane wake. The effects of wake strengths and the reduced frequency on the unsteady boundary layer development on a low-speed axial compressor were investigated using particle image velocimetry. The measurements were carried out at two reduced frequencies (fr = fIGVS0/U2i, fr = 1.35, and fr = 0.675) with the Reynolds number, based on the blade chord and the isentropic inlet velocity, being 97 500. At fr = 1.35, the flow separated at the trailing edge when the wake strength was weak. However, the separation was almost totally suppressed as the wake strength increased. For the stronger wake, both the wake's high turbulence and the negative jet behavior of the wake dominated the interaction between the unsteady wake and the separated boundary layer on the suction surface of the airfoil. The boundary layer displacement thickened first due to the negative jet effect. Then, as the disturbances developed underneath the wake, the boundary layer thickness reduced gradually. The high disturbance region convected downstream at a fraction of the free-stream velocity and spread in the streamwise direction. The separation on the suction surface was suppressed until the next wake's arrival. Because of the long recovery time at fr = 0.675, the boundary layer thickened gradually as the wake convected further downstream and finally separated due to the adverse pressure gradient. The different boundary layer states in turn affected the development of disturbances.

Collaborative diagramming during problem based learning in medical education: Do computerized diagrams support basic science knowledge construction?

NARCIS (Netherlands)

de Leng, Bas; Gijlers, Aaltje H.

2015-01-01

Aim: To examine how collaborative diagramming affects discussion and knowledge construction when learning complex basic science topics in medical education, including its effectiveness in the reformulation phase of problem-based learning. Methods: Opinions and perceptions of students (n = 70) and

Particle Entrainment in Spherical-Cap Wakes

Energy Technology Data Exchange (ETDEWEB)

Warncke, Norbert G W; Delfos, Rene; Ooms, Gijs; Westerweel, Jerry, E-mail: n.g.w.warncke@tudelft.nl [Laboratory for Aero- and Hydrodynamics, Delft University of Technology (Netherlands)

2011-12-22

In this work we study the preferential concentration of small particles in the turbulent wake behind a spherical-cap object. We present a model predicting the mean particle concentration in the near-wake as a function of the characteristic Stokes number of the problem, the turbulence level and the Froude number. We compare the model with our experimental results on this flow, measured in a vertical water tunnel.

Validation of the Dynamic Wake Meander model with focus on tower loads

Science.gov (United States)

Larsen, T. J.; Larsen, G. C.; Pedersen, M. M.; Enevoldsen, K.; Madsen, H. A.

2017-05-01

This paper presents a comparison between measured and simulated tower loads for the Danish offshore wind farm Nysted 2. Previously, only limited full scale experimental data containing tower load measurements have been published, and in many cases the measurements include only a limited range of wind speeds. In general, tower loads in wake conditions are very challenging to predict correctly in simulations. The Nysted project offers an improved insight to this field as six wind turbines located in the Nysted II wind farm have been instrumented to measure tower top and tower bottom moments. All recorded structural data have been organized in a database, which in addition contains relevant wind turbine SCADA data as well as relevant meteorological data - e.g. wind speed and wind direction - from an offshore mast located in the immediate vicinity of the wind farm. The database contains data from a period extending over a time span of more than 3 years. Based on the recorded data basic mechanisms driving the increased loading experienced by wind turbines operating in offshore wind farm conditions have been identified, characterized and modeled. The modeling is based on the Dynamic Wake Meandering (DWM) approach in combination with the state-of-the-art aeroelastic model HAWC2, and has previously as well as in this study shown good agreement with the measurements. The conclusions from the study have several parts. In general the tower bending and yaw loads show a good agreement between measurements and simulations. However, there are situations that are still difficult to match. One is tower loads of single-wake operation near rated ambient wind speed for single wake situations for spacing’s around 7-8D. A specific target of the study was to investigate whether the largest tower fatigue loads are associated with a certain downstream distance. This has been identified in both simulations and measurements, though a rather flat optimum is seen in the measurements.

Application of staring lidars to study the dynamics of wind turbine wakes

Directory of Open Access Journals (Sweden)

Davide Trabucchi

2015-11-01

Full Text Available Standard anemometry or vertical profiling remote sensing are not always a convenient approach to study the dynamics of wind turbines wake. One or more lidar windscanner can be applied for this purpose. In this paper a measurement strategy is presented, which permits the characterization of the wake dynamics using two long range wind lidars operated in a stationary mode. In this approach two pulsed devices are staring with low elevation obliquely across the wake. The lidar beams are supposed to cross each other on the downstream axis of the wake to perform simultaneous measurements in the wake field from side to side. The deflection of the wake is identified fitting a model to the average data. Spectral analysis provide the frequency content of the measurements at different distances from the wake center. This setup was implemented in a full-field measurement campaign where the wake of a multi-MW wind turbine was analysed. The tracking of the wake centre was applied successfully to this measurement. Moreover the spectral analysis showed increased energy content close to the wake lateral edges. This can be connected both to the higher turbulence level due to the tip vorteces and to the large scale dynamics of the wake.

Iowa Test of Basic Skills, 2000-2001. Measuring Up. E&R Report.

Science.gov (United States)

Tyler, Doris

In the Wake County Public School System (WCPSS), North Carolina, the Iowa Test of Basic Skills (ITBS) is administered to all third grade students each year. The ITBS, which is one of the assessments used as a screening tool for the Academically Gifted Program, was given to approximately 7,700 third graders in 2000. The ITBS can be given as a…

Developing a competency-based medical education curriculum for the core basic medical sciences in an African Medical School

Directory of Open Access Journals (Sweden)

Olopade FE

2016-07-01

Full Text Available Funmilayo Eniola Olopade,1 Oluwatosin Adekunle Adaramoye,2 Yinusa Raji,3 Abiodun Olubayo Fasola,4 Emiola Oluwabunmi Olapade-Olaopa5 1Department of Anatomy, 2Department of Biochemistry, 3Department of Physiology, 4Department of Oral Pathology, 5Department of Surgery, College of Medicine, University of Ibadan, Ibadan, Nigeria Abstract: The College of Medicine of the University of Ibadan recently revised its MBBS and BDS curricula to a competency-based medical education method of instruction. This paper reports the process of revising the methods of instruction and assessment in the core basic medical sciences directed at producing medical and dental graduates with a sound knowledge of the subjects sufficient for medical and dental practice and for future postgraduate efforts in the field or related disciplines. The health needs of the community and views of stakeholders in the Ibadan medical and dental schools were determined, and the “old” curriculum was reviewed. This process was directed at identifying the strengths and weaknesses of the old curricula and the newer competences required for modern-day medical/dental practice. The admission criteria and processes and the learning methods of the students were also studied. At the end of the review, an integrated, system-based, community-oriented, person-centered, and competency-driven curriculum was produced and approved for implementation. Four sets of students have been admitted into the curriculum. There have been challenges to the implementation process, but these have been overcome by continuous faculty development and reorientation programs for the nonteaching staff and students. Two sets of students have crossed over to the clinical school, and the consensus among the clinical teachers is that their knowledge and application of the basic medical sciences are satisfactory. The Ibadan medical and dental schools are implementing their competency-based medical education curricula

Surface Characteristics of Green Island Wakes from Satellite Imagery

Science.gov (United States)

Cheng, Kai-Ho; Hsu, Po-Chun; Ho, Chung-Ru

2017-04-01

Characteristics of an island wake induced by the Kuroshio Current flows pass by Green Island, a small island 40 km off southeast of Taiwan is investigated by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. The MODIS sea surface temperature (SST) and chlorophyll-a (chl-a) imagery is produced at 250-meter resolution from 2014 to 2015 using the SeaDAS software package which is developed by the National Aeronautics and Space Administration. The wake occurrence is 59% observed from SST images during the data span. The average cooling area is 190 km2, but the area is significantly changed with wind directions. The wake area is increased during southerly winds and is reduced during northerly winds. Besides, the average cooling SST was about 2.1 oC between the front and rear island. Comparing the temperature difference between the wake and its left side, the difference is 1.96 oC. In addition, the wakes have 1 3 times higher than normal in chlorophyll concentration. The results indicate the island mass effect makes the surface water of Green island wake colder and chl-a higher.

Passive propulsion in vortex wakes

Science.gov (United States)

Beal, D. N.; Hover, F. S.; Triantafyllou, M. S.; Liao, J. C.; Lauder, G. V.

A dead fish is propelled upstream when its flexible body resonates with oncoming vortices formed in the wake of a bluff cylinder, despite being well outside the suction region of the cylinder. Within this passive propulsion mode, the body of the fish extracts sufficient energy from the oncoming vortices to develop thrust to overcome its own drag. In a similar turbulent wake and at roughly the same distance behind a bluff cylinder, a passively mounted high-aspect-ratio foil is also shown to propel itself upstream employing a similar flow energy extraction mechanism. In this case, mechanical energy is extracted from the flow at the same time that thrust is produced. These results prove experimentally that, under proper conditions, a body can follow at a distance or even catch up to another upstream body without expending any energy of its own. This observation is also significant in the development of low-drag energy harvesting devices, and in the energetics of fish dwelling in flowing water and swimming behind wake-forming obstacles.

Canopy wake measurements using multiple scanning wind LiDARs

Science.gov (United States)

Markfort, C. D.; Carbajo Fuertes, F.; Iungo, V.; Stefan, H. G.; Porte-Agel, F.

2014-12-01

Canopy wakes have been shown, in controlled wind tunnel experiments, to significantly affect the fluxes of momentum, heat and other scalars at the land and water surface over distances of ˜O(1 km), see Markfort et al. (EFM, 2013). However, there are currently no measurements of the velocity field downwind of a full-scale forest canopy. Point-based anemometer measurements of wake turbulence provide limited insight into the extent and details of the wake structure, whereas scanning Doppler wind LiDARs can provide information on how the wake evolves in space and varies over time. For the first time, we present measurements of the velocity field in the wake of a tall patch of forest canopy. The patch consists of two uniform rows of 40-meter tall deciduous, plane trees, which border either side of the Allée de Dorigny, near the EPFL campus. The canopy is approximately 250 m long, and it is approximately 40 m wide, along the direction of the wind. A challenge faced while making field measurements is that the wind rarely intersects a canopy normal to the edge. The resulting wake flow may be deflected relative to the mean inflow. Using multiple LiDARs, we measure the evolution of the wake due to an oblique wind blowing over the canopy. One LiDAR is positioned directly downwind of the canopy to measure the flow along the mean wind direction and the other is positioned near the canopy to evaluate the transversal component of the wind and how it varies with downwind distance from the canopy. Preliminary results show that the open trunk space near the base of the canopy results in a surface jet that can be detected just downwind of the canopy and farther downwind dissipates as it mixes with the wake flow above. A time-varying recirculation zone can be detected by the periodic reversal of the velocity near the surface, downwind of the canopy. The implications of canopy wakes for measurement and modeling of surface fluxes will be discussed.

Experimental investigation of main rotor wake

Directory of Open Access Journals (Sweden)

Stepanov Robert

2017-01-01

Full Text Available In this work, experimental results of rotor wake in hover mode are presented. The experiments were carried out with a rotor rig model in the T-1K wind tunnel in Kazan National Research Technical University (Kazan Aviation Institute. The rotor consisted of four identical blades. The Q-criterion was used to identify tip vortices for a 2D case. The results were then compared with two different wake models.

Measurements of Wake-Riding Electrons in Antiproton-Carbon-Foil Collisions

CERN Multimedia

2002-01-01

When a charged particle passes through dielectric media, e.g. a thin carbon foil, a ``wake'' is induced. The characteristic wake-potential shows an oscillatory behaviour, with a wavelength of about $ 2 \\pi v _{p} / \\omega _{p} _{l} $ where $ v _{p} $ is the projectile velocity and $ \\omega _{p} _{l} $ the plasmon energy of the target. This induced wake potential is superimposed on the Coulomb potential of the projectile, the latter leading to a pronounced ``cusp'' of electrons leaving the solid at $ v _{e} app v _{p} $ for positively charged projectiles in the MeV region. Correspondingly, an ``anti-cusp'' is expected for antiprotons. \\\\ \\\\ In the solid, the wake-potential leads to an attractive force on electrons, and a dynamic electronic state is predicted both for proton and antiproton projectiles. In the solid, the wake-riding electrons are travelling with the projectile speed $ v _{p} $ Upon exit of the foil, the electron released from the wake-riding state of an antiproton will suddenly find itself in th...

Wake characteristics of wind turbines in utility-scale wind farms

Science.gov (United States)

Yang, Xiaolei; Foti, Daniel; Sotiropoulos, Fotis

2017-11-01

The dynamics of turbine wakes is affected by turbine operating conditions, ambient atmospheric turbulent flows, and wakes from upwind turbines. Investigations of the wake from a single turbine have been extensively carried out in the literature. Studies on the wake dynamics in utility-scale wind farms are relatively limited. In this work, we employ large-eddy simulation with an actuator surface or actuator line model for turbine blades to investigate the wake dynamics in utility-scale wind farms. Simulations of three wind farms, i.e., the Horns Rev wind farm in Denmark, Pleasant Valley wind farm in Minnesota, and the Vantage wind farm in Washington are carried out. The computed power shows a good agreement with measurements. Analysis of the wake dynamics in the three wind farms is underway and will be presented in the conference. This work was support by Xcel Energy (RD4-13). The computational resources were provided by National Renewable Energy Laboratory.

Two improvements to the dynamic wake meandering model: including the effects of atmospheric shear on wake turbulence and incorporating turbulence build-up in a row of wind turbines

DEFF Research Database (Denmark)

Keck, Rolf-Erik; de Mare, Martin Tobias; Churchfield, Matthew J.

2015-01-01

The dynamic wake meandering (DWM) model is an engineering wake model designed to physically model the wake deficit evolution and the unsteady meandering that occurs in wind turbine wakes. The present study aims at improving two features of the model: The effect of the atmospheric boundary layer s...

Controlled Wake of a Moving Axisymmetric Bluff Body

Science.gov (United States)

Lee, E.; Vukasinovic, B.; Glezer, A.

2017-11-01

The aerodynamic loads exerted on a wire-mounted axisymmetric bluff body in prescribed rigid motion are controlled by fluidic manipulation of its near wake. The body is supported by a six-degree of freedom eight-wire traverse and its motion is controlled using a dedicated servo actuator and inline load cell for each wire. The instantaneous aerodynamic forces and moments on the moving body are manipulated by controlled interactions of an azimuthal array of integrated synthetic jet actuators with the cross flow to induce localized flow attachment over the body's aft end and thereby alter the symmetry of the wake. The coupled interactions between the wake structure and the effected aerodynamic loads during prescribed time-periodic and transitory (gust like) motions are investigated with emphasis on enhancing or diminishing the loads for maneuver control, and decoupling the body's motion from its far wake.

Self-similar potential in the near wake

International Nuclear Information System (INIS)

Diebold, D.; Hershkowitz, N.; Intrator, T.; Bailey, A.

1987-01-01

The plasma potential is measured near the edge of an electrically floating obstacle placed in a steady-state, supersonic, unmagnetized, neutral plasma flow. Equipotential contours show the sheath of the upstream side of the obstacle wrapping around the edge of the obstacle and fanning out into the near wake. Both fluid theory and the data find the near-wake plasma potential to be self-similar when ionization, charge exchange, and magnetic field can be neglected. The theory also finds that fluid velocity is self-similar, the near wake is nonneutral, and plasma density is not self-similar. Strong electric fields are found near the obstacle and equipotential contours are found to conform to all boundaries

The resonant wake field transformer (RWT)-collider

International Nuclear Information System (INIS)

Weiland, T.; Holtkamp, N.; Schuett, P.; Wanzenberg, R.

1990-01-01

Future e + e - Linear Colliders with center of mass energies of 2 TeV need average accelerating gradients of 100 MeV/m to be built within a length of 20 km. The gradients required by colliders at this energy range can be economically provided by resonant Wake Field Transformers. At the Wake Field Experiment at DESY (Deutsches Elektronen-Synchrotron) a 20 cm long transformer section was investigated and the most recent results are presented. The second part gives a short overview of the present status of research concerning the proposed next stage of a multibunch driver linac with superconducting cavities and long Wake Field Transformer sections. (author) 9 refs.; 5 figs.; 1 tab

Wind Farm Wake: The Horns Rev Photo Case

DEFF Research Database (Denmark)

Hasager, Charlotte Bay; Rasmussen, Leif; Peña, Alfredo

2013-01-01

The aim of the paper is to examine the nowadays well-known wind farm wake photographs taken on 12 February 2008 at the offshore Horns Rev 1 wind farm. The meteorological conditions are described from observations from several satellite sensors quantifying clouds, surface wind vectors and sea surf...... in the wake regions with relatively high axial velocities and high turbulent kinetic energy. The wind speed is near cut-in and most turbines produce very little power. The rotational pattern of spiraling bands produces the large-scale structure of the wake fog....

An Aeroelastic Perspective of Floating Offshore Wind Turbine Wake Formation and Instability

Science.gov (United States)

Rodriguez, Steven N.; Jaworski, Justin W.

2015-11-01

The wake formation and wake stability of floating offshore wind turbines are investigated from an aeroelastic perspective. The aeroelastic model is composed of the Sebastian-Lackner free-vortex wake aerodynamic model coupled to the nonlinear Hodges-Dowell beam equations, which are extended to include the effects of blade profile asymmetry, higher-order torsional effects, and kinetic energy components associated with periodic rigid-body motions of floating platforms. Rigid-body platform motions are also assigned to the aerodynamic model as varying inflow conditions to emulate operational rotor-wake interactions. Careful attention is given to the wake formation within operational states where the ratio of inflow velocity to induced velocity is over 50%. These states are most susceptible to aerodynamic instabilities, and provide a range of states about which a wake stability analysis can be performed. In addition, the stability analysis used for the numerical framework is implemented into a standalone free-vortex wake aerodynamic model. Both aeroelastic and standalone aerodynamic results are compared to evaluate the level of impact that flexible blades have on the wake formation and wake stability.

Basic pharmaceutical technology

OpenAIRE

Angelovska, Bistra; Drakalska, Elena

2017-01-01

The lecture deals with basics of pharmaceutical technology as applied discipline of pharmaceutical science, whose main subject of study is formulation and manufacture of drugs. In a broad sense, pharmaceutical technology is science of formulation, preparation, stabilization and determination of the quality of medicines prepared in the pharmacy or in pharmaceutical industry

Circadian Rhythm Sleep-Wake Disorders.

Science.gov (United States)

Abbott, Sabra M; Reid, Kathryn J; Zee, Phyllis C

2015-12-01

The circadian system regulates the timing and expression of nearly all biological processes, most notably, the sleep-wake cycle, and disruption of this system can result in adverse effects on both physical and mental health. The circadian rhythm sleep-wake disorders (CRSWDs) consist of 5 disorders that are due primarily to pathology of the circadian clock or to a misalignment of the timing of the endogenous circadian rhythm with the environment. This article outlines the nature of these disorders, the association of many of these disorders with psychiatric illness, and available treatment options. Copyright © 2015 Elsevier Inc. All rights reserved.

Guidelines for DOE Long Term Civilian Research and Development. Volume III. Basic Energy Sciences, High Energy and Nuclear Physics

International Nuclear Information System (INIS)

1985-12-01

The Research Panel prepared two reports. This report reviews the Department of Energy's Basic Energy Sciences, High Energy Physics, and Nuclear Physics programs. The second report examines the Environment, Health and Safety programs in the Department. This summary addresses the general value and priority of basic research programs for the Department of Energy and the nation. In addition, it describes the key strategic issues and major recommendations for each program area

Competence of matric physical science teachers in some basic problem-solving strategies

Directory of Open Access Journals (Sweden)

Mailoo Selvaratnam

2011-01-01

Full Text Available The National Curriculum Statement for matric physical science places strong emphasis on the development of critical thinking and reasoning abilities of pupils. The successful implementation of this curriculum therefore requires teachers who are competent in the cognitive (intellectual skills and strategies needed for learning science effectively. Testing of teachers’ competence in this aspect is therefore important. I therefore analysed teachers’ answers to questions that were carefully designed to test competence in some basic intellectual strategies that are important for problem solving in physical science courses. A total of 73 matric physical science teachers, from about 50 Dinaledi schools in the North West and KwaZulu-Natal provinces in South Africa, were tested in five intellectual strategies: clear representation of problems, identifying and focusing on the goal, identification and use of relevant principles, use of equations for deductions and proceeding step-by-step with the solution. The teachers’ competence was poor in all the intellectual strategies tested. About 60% (the average performance in all 13 questions used for testing of teachers tested were unable to solve the questions correctly. An important objective of the curriculum is the development of critical thinking, scientific reasoning and strategies of pupils. This study shows that the achievement of this objective will be seriously handicapped because of the lack of competence of many teachers in intellectual strategies. There is therefore a need to train teachers in order to increase their competence in this aspect.

Fast particle tracking with wake fields

Energy Technology Data Exchange (ETDEWEB)

Dohlus, M.; Floettmann, K.; Henning, C.

2012-01-15

Tracking calculations of charged particles in electromagnetic fields require in principle the simultaneous solution of the equation of motion and of Maxwell's equations. In many tracking codes a simpler and more efficient approach is used: external fields like that of the accelerating structures are provided as field maps, generated in separate computations and for the calculation of self fields the model of a particle bunch in uniform motion is used. We describe how an externally computed wake function can be approximated by a table of Taylor coefficients and how the wake field kick can be calculated for the particle distribution in a tracking calculation. The integrated kick, representing the effect of a distributed structure, is applied at a discrete time. As an example, we use our approach to calculate the emittance growth of a bunch in an undulator beam pipe due to resistive wall wake field effects. (orig.)

Airfoil-Wake Modification with Gurney Flap at Low Reynolds Number

Science.gov (United States)

Gopalakrishnan Meena, Muralikrishnan; Taira, Kunihiko; Asai, Keisuke

2018-04-01

The complex wake modifications produced by a Gurney flap on symmetric NACA airfoils at low Reynolds number are investigated. Two-dimensional incompressible flows over NACA 0000 (flat plate), 0006, 0012 and 0018 airfoils at a Reynolds number of $Re = 1000$ are analyzed numerically to examine the flow modifications generated by the flaps for achieving lift enhancement. While high lift can be attained by the Gurney flap on airfoils at high angles of attack, highly unsteady nature of the aerodynamic forces are also observed. Analysis of the wake structures along with the lift spectra reveals four characteristic wake modes (steady, 2S, P and 2P), influencing the aerodynamic performance. The effects of the flap over wide range of angles of attack and flap heights are considered to identify the occurrence of these wake modes, and are encapsulated in a wake classification diagram. Companion three-dimensional simulations are also performed to examine the influence of three-dimensionality on the wake regimes. The spanwise instabilities that appear for higher angles of attack are found to suppress the emergence of the 2P mode. The use of the wake classification diagram as a guidance for Gurney flap selection at different operating conditions to achieve the required aerodynamic performance is discussed.

Measurements on the extended range of the wake

International Nuclear Information System (INIS)

Kumbartzki, G.J.; Kroesing, G; Neuburger, H.

1981-01-01

The Coulomb explosion of H 2 + -ions at 28 MeV is used to probe the wake over a range of about 400 A in Al. Preliminary results give food agreement with the wavelength prediction of the simple plasma oscillation wake model. (author)

Pharmacy students' use and perceptions of Apple mobile devices incorporated into a basic health science laboratory.

Science.gov (United States)

Bryant, Jennifer E; Richard, Craig A H

To describe pharmacy students' use of mobile devices in a basic health science laboratory and to report the students' perceptions on how solving cases with their mobile devices influenced their attitudes, abilities, and view on the use of mobile devices as tools for pharmacists. First-year pharmacy students utilized mobile devices to solve clinical case studies in a basic health sciences laboratory. A pre-survey and two post-surveys were administered to assess the students' comfort, awareness, use, and perceptions on the use of their mobile devices and apps. The pre-survey and first post-survey each had a response rate of 99%, and the second post-survey had a response rate of 100%. In comparing the pre-survey and first post-survey data, there was a statistically significant increase in the number of students that agreed or strongly agreed that they were more comfortable utilizing their mobile device (p = 0.025), they were more aware of apps for pharmacists (p mobile devices, to be more aware of apps that can be useful for pharmacists, and to be more agreeable with mobile device utilization by pharmacists in improving patient care. In addition, the second post-survey also demonstrated that 84% of students responded that using their mobile devices to solve the cases influenced them to either use their mobile device in a clinical setting for a clinical and/or pharmacy-related purpose for the first time or to use it more frequently for this purpose. The use of mobile devices to solve clinical cases in a first-year basic health science laboratory course was perceived as beneficial by students and influenced them to utilize their mobile device even more in a pharmacy practice setting. Copyright © 2016 Elsevier Inc. All rights reserved.

A Survey of the Scattering Characteristics and Detection of Aircraft Wake Vortices

Directory of Open Access Journals (Sweden)

Li Jianbing

2017-12-01

Full Text Available Aircraft wake vortex is a pair of strong counter-rotating vortices and has attracted considerable attention in various fields including aviation safety and atmospheric physics. The characteristics and detection of wake vortex act as the basis for both behavior prediction as well as hazard assessment. This paper provides a short survey of the characteristics and detection researches. Initially, the wake vortex is classified as clear-air wake vortex (i.e., wake turbulence and contrail and precipitation wake vortex (i.e., under rainy, foggy or snowy condition. Subsequently, the dynamics and scattering are introduced, and the main verdicts are: the radar (radio detection and ranging scattering of wake vortex is relatively weak under clear air conditions, but the Lidar (Light detection and ranging scattering is appreciable owing to the presence of particles such as aerosols. Wake vortices under precipitation conditions and contrails possess relatively good radar reflectivity owing the strong scattering characteristics of precipitation droplets and ice crystals. Furthermore, we have introduced a joint detection scheme of Lidar and radar for wake vortex along with parameter-retrieval algorithms. Finally, we have presented our conclusions and intended future research.

Self-similarity of far wake behind tandem of two disks

DEFF Research Database (Denmark)

Okulov, Valery; Litvinov, I. V.; Naumov, I. V.

2017-01-01

the wake ceased to differ from the background of natural turbulent fluctuations of the incident flow. It has been found that the position of the second disk in the tandem affects the energy loss in the wake due to its expansion but does not influence the decay. The revealed patterns in the wake development...

Impact of bubble wakes on a developing bubble flow in a vertical pipe

International Nuclear Information System (INIS)

Tomiyama, A.; Makino, Y.; Miyoshi, K.; Tamai, H.; Serizawa, A.; Zun, I.

1998-01-01

Three-dimensional two-way bubble tracking simulation of single large air bubbles rising through a stagnant water filled in a vertical pipe was conducted to investigate the structures of bubble wakes. Spatial distributions of time-averaged liquid velocity field, turbulent intensity and Reynolds stress caused by bubble wakes were deduced from the calculated local instantaneous liquid velocities. It was confirmed that wake structures are completely different from the ones estimated by a conventional wake model. Then, we developed a simple wake model based on the predicted time-averaged wake velocity fields, and implemented it into a 3D one-way bubble tracking method to examine the impact of bubble wake structures on time-spatial evolution of a developing air-water bubble flow in a vertical pipe. As a results, we confirmed that the developed wake model can give better prediction for flow pattern evolution than a conventional wake model

Computational study of three-dimensional wake structure

International Nuclear Information System (INIS)

Himeno, R.; Shirayama, S.; Kamo, K.; Kuwahara, K.

1986-01-01

Three-dimensional wake structure is studied by numerically solving the incompressible Navier-Stokes equations. Results are visualized by a three-dimensional color graphic system. It was found that a pair of vortex tubes separated from a body plays the most important role in the wake. Near the body vortex tubes are rather stable, however, they gradually become unsteady as they flow down

On the Effects of Wind Turbine Wake Skew Caused by Wind Veer: Preprint

Energy Technology Data Exchange (ETDEWEB)

Churchfield, Matthew J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-01

Because of Coriolis forces caused by the Earth's rotation, the structure of the atmospheric boundary layer often contains wind-direction change with height, also known as wind-direction veer. Under low turbulence conditions, such as in stably stratified atmospheric conditions, this veer can be significant, even across the vertical extent of a wind turbine's rotor disk. The veer then causes the wind turbine wake to skew as it advects downstream. This wake skew has been observed both experimentally and numerically. In this work, we attempt to examine the wake skewing process in some detail, and quantify how differently a skewed wake versus a non skewed wake affects a downstream turbine. We do this by performing atmospheric large-eddy simulations to create turbulent inflow winds with and without veer. In the veer case, there is a roughly 8 degree wind direction change across the turbine rotor. We then perform subsequent large-eddy simulations using these inflow data with an actuator line rotor model to create wakes. The turbine modeled is a large, modern, offshore, multimegawatt turbine. We examine the unsteady wake data in detail and show that the skewed wake recovers faster than the non skewed wake. We also show that the wake deficit does not skew to the same degree that a passive tracer would if subject to veered inflow. Last, we use the wake data to place a hypothetical turbine 9 rotor diameters downstream by running aeroelastic simulations with the simulated wake data. We see differences in power and loads if this downstream turbine is subject to a skewed or non skewed wake. We feel that the differences observed between the skewed and nonskewed wake are important enough that the skewing effect should be included in engineering wake models.

Next Generation Scanning LIDAR Systems for Optimizing Wake Turbulence Separation Minima

Directory of Open Access Journals (Sweden)

Ludovic Thobois

2017-12-01

Full Text Available Numerous studies have been performed to better understand the behavior of wake vortices with regards to aircraft characteristics and weather conditionsover the pastten years. These studies have led to the development of the aircraft RECATegorization (RECAT programs in Europe and in USA. Its phase one focused on redefining distance separation matrix with six static aircraft wake turbulence categories instead of three with the current International Civil Aviation Organization (ICAO regulations. In Europe, the RECAT-EU regulation is now entering under operational implementation atseveral key airports. As proven by several research projects in the past, LIght Detection And Ranging (LIDAR sensors are considered as the ground truth wake vortex measurements for assessing the safety impact of a new wake turbulence regulation at an airport in quantifying the risks given the local specificities. LIDAR’s can also be used to perform risk monitoring after the implementation. In this paper, the principle to measure wake vortices with scanning coherent Doppler LIDARs is described as well as its dedicated post-processing. Finally the use of WINDCUBELIDAR based solution for supporting the implementation of new wake turbulenceregulation is described along with satisfyingresults that have permitted the monitoring of the wake vortex encounter risk after the implementation of a new wake turbulence regulation.

A review of recent wake vortex research for increasing airport capacity

Science.gov (United States)

Hallock, James N.; Holzäpfel, Frank

2018-04-01

This paper is a brief review of recent wake vortex research as it affects the operational problem of spacing aircraft to increase airport capacity and throughput. The paper addresses the questions of what do we know about wake vortices and what don't we know about wake vortices. The introduction of Heavy jets in the late 1960s stimulated the study of wake vortices for safety reasons and the use of pulsed lidars and the maturity of computational fluid dynamics in the last three decades have led to extensive data collection and analyses which are now resulting in the development and implementation of systems to safely decrease separations in the terminal environment. Although much has been learned about wake vortices and their behavior, there is still more to be learned about the phenomena of aircraft wake vortices.

A study of the academic performance of medical students in the comprehensive examination of the basic sciences according to the indices of emotional intelligence and educational status.

Science.gov (United States)

Moslehi, Mohsen; Samouei, Rahele; Tayebani, Tayebeh; Kolahduz, Sima

2015-01-01

Considering the increasing importance of emotional intelligence (EI) in different aspects of life, such as academic achievement, the present survey is aimed to predict academic performance of medical students in the comprehensive examination of the basic sciences, according to the indices of emotional intelligence and educational status. The present survey is a descriptive, analytical, and cross-sectional study performed on the medical students of Isfahan, Tehran, and Mashhad Universities of Medical Sciences. Sampling the universities was performed randomly after which selecting the students was done, taking into consideration the limitation in their numbers. Based on the inclusion criteria, all the medical students, entrance of 2005, who had attended the comprehensive basic sciences examination in 2008, entered the study. The data collection tools included an Emotional Intelligence Questionnaire (standardized in Isfahan), the average score of the first to fifth semesters, total average of each of the five semesters, and the grade of the comprehensive basic sciences examination. The data were analyzed through stepwise regression coefficient by SPSS software version 15. The results indicated that the indicators of independence from an emotional intelligence test and average scores of the first and third academic semesters were significant in predicting the students' academic performance in the comprehensive basic sciences examination. According to the obtained results, the average scores of students, especially in the earlier semesters, as well as the indicators of independence and the self-esteem rate of students can influence their success in the comprehensive basic sciences examination.

Wake meandering of a model wind turbine operating in two different regimes

Science.gov (United States)

Foti, Daniel; Yang, Xiaolei; Campagnolo, Filippo; Maniaci, David; Sotiropoulos, Fotis

2018-05-01

The flow behind a model wind turbine under two different turbine operating regimes (region 2 for turbine operating at optimal condition with the maximum power coefficient and 1.4-deg pitch angle and region 3 for turbine operating at suboptimal condition with a lower power coefficient and 7-deg pitch angle) is investigated using wind tunnel experiments and numerical experiments using large-eddy simulation (LES) with actuator surface models for turbine blades and nacelle. Measurements from the model wind turbine experiment reveal that the power coefficient and turbine wake are affected by the operating regime. Simulations with and without a nacelle model are carried out for each operating condition to study the influence of the operating regime and nacelle on the formation of the hub vortex and wake meandering. Statistics and energy spectra of the simulated wakes are in good agreement with the measurements. For simulations with a nacelle model, the mean flow field is composed of an outer wake, caused by energy extraction by turbine blades, and an inner wake directly behind the nacelle, while for the simulations without a nacelle model, the central region of the wake is occupied by a jet. The simulations with the nacelle model reveal an unstable helical hub vortex expanding outward toward the outer wake, while the simulations without a nacelle model show a stable and columnar hub vortex. Because of the different interactions of the inner region of the wake with the outer region of the wake, a region with higher turbulence intensity is observed in the tip shear layer for the simulation with a nacelle model. The hub vortex for the turbine operating in region 3 remains in a tight helical spiral and intercepts the outer wake a few diameters further downstream than for the turbine operating in region 2. Wake meandering, a low-frequency large-scale motion of the wake, commences in the region of high turbulence intensity for all simulations with and without a nacelle model

A new approach for evaluating measured wake data

Energy Technology Data Exchange (ETDEWEB)

Magnusson, Mikael [Uppsala Univ. (Sweden). Dept. of Meteorology

1996-12-01

Wind turbine wakes have been studied by analysing a large set of atmospheric data, from a wind farm with four turbines sited on a flat coastal area. The results obtained have ben generalized to allow tests against data from other full scale wind turbines as well as wind tunnel simulations. These comparisons are found to give very satisfactory results. The thrust coefficient is found to be a better parameter for description than wind speed, of wake characteristics because it implicitly includes the effect of regulation. It is also found that down-wind travel time is more convenient to use than down-wind distance in this context. The travel time to the end of the near wake region, i.e. to the point where a single velocity deficit peak first appears, is found to be inversely proportional to the rotational frequency of the turbine and to the turbulence intensity of the ambient air flow and proportional to the ratio of the wake radius and the hub height. For larger travel times, i.e. for the far wake region, it is found that the centre line relative velocity deficit decreases with the logarithm of the time traveled and is parametrically dependent on the time constant and the thrust coefficient. 3 refs, 5 figs

CFD three dimensional wake analysis in complex terrain

Science.gov (United States)

Castellani, F.; Astolfi, D.; Terzi, L.

2017-11-01

Even if wind energy technology is nowadays fully developed, the use of wind energy in very complex terrain is still challenging. In particular, it is challenging to characterize the combination effects of wind ow over complex terrain and wake interactions between nearby turbines and this has a practical relevance too, for the perspective of mitigating anomalous vibrations and loads as well improving the farm efficiency. In this work, a very complex terrain site has been analyzed through a Reynolds-averaged CFD (Computational Fluid Dynamics) numerical wind field model; in the simulation the inuence of wakes has been included through the Actuator Disk (AD) approach. In particular, the upstream turbine of a cluster of 4 wind turbines having 2.3 MW of rated power is studied. The objective of this study is investigating the full three-dimensional wind field and the impact of three-dimensionality on the evolution of the waked area between nearby turbines. A post-processing method of the output of the CFD simulation is developed and this allows to estimate the wake lateral deviation and the wake width. The reliability of the numerical approach is inspired by and crosschecked through the analysis of the operational SCADA (Supervisory Control and Data Acquisition) data of the cluster of interest.

Wake field acceleration experiments

International Nuclear Information System (INIS)

Simpson, J.D.

1988-01-01

Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

Radiative Forcing Over Ocean by Ship Wakes

Science.gov (United States)

Gatebe, Charles K.; Wilcox, E.; Poudyal, R.; Wang, J.

2011-01-01

Changes in surface albedo represent one of the main forcing agents that can counteract, to some extent, the positive forcing from increasing greenhouse gas concentrations. Here, we report on enhanced ocean reflectance from ship wakes over the Pacific Ocean near the California coast, where we determined, based on airborne radiation measurements that ship wakes can increase reflected sunlight by more than 100%. We assessed the importance of this increase to climate forcing, where we estimated the global radiative forcing of ship wakes to be -0.00014 plus or minus 53% Watts per square meter assuming a global distribution of 32331 ships of size of greater than or equal to 100000 gross tonnage. The forcing is smaller than the forcing of aircraft contrails (-0.007 to +0.02 Watts per square meter), but considering that the global shipping fleet has rapidly grown in the last five decades and this trend is likely to continue because of the need of more inter-continental transportation as a result of economic globalization, we argue that the radiative forcing of wakes is expected to be increasingly important especially in harbors and coastal regions.

Optogenetic deconstruction of sleep-wake circuitry in the brain

Directory of Open Access Journals (Sweden)

Antoine Adamantidis

2010-01-01

Full Text Available How does the brain regulate the sleep-wake cycle? What are the temporal codes of sleep- and wake-promoting neural circuits? How do these circuits interact with each other across the light/dark cycle? Over the past few decades, many studies from a variety of disciplines have made substantial progress in answering these fundamental questions. For example, neurobiologists have identified multiple, redundant wake-promoting circuits in the brainstem, hypothalamus, and basal forebrain. Sleep-promoting circuits have been found in the preoptic area and hypothalamus. One of the greatest challenges in recent years has been to selectively record and manipulate these sleep-wake centers in vivo with high spatial and temporal resolution. Recent developments in microbial opsin-based neuromodulation tools, collectively referred to as “optogenetics,” have provided a novel method to demonstrate causal links between neural activity and specific behaviors. Here, we propose to use optogenetics as a fundamental tool to probe the necessity, sufficiency, and connectivity of defined neural circuits in the regulation of sleep and wakefulness.

Flow Structures within a Helicopter Rotor Hub Wake

Science.gov (United States)

Elbing, Brian; Reich, David; Schmitz, Sven

2015-11-01

A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

LES of an Advancing Helicopter Rotor, and Near to Far Wake Assessment

Science.gov (United States)

Caprace, Denis-Gabriel; Duponcheel, Matthieu; Chatelain, Philippe; Winckelmans, Grégoire

2017-11-01

Helicopter wake physics involve complex, unsteady vortical flows which have been only scarcely addressed in past studies. The present work focuses on LES of the wake flow behind an advancing rotor, to support the investigation of rotorcraft wake physics and decay mechanisms. A hybrid Vortex Particle-Mesh (VPM) method is employed to simulate the wake of an articulated four-bladed rotor in trimmed conditions, at an advance ratio of 0.41. The simulation domain extends to 30 rotor diameters downstream. The coarse scale aerodynamics of the blades are accounted for through enhanced immersed lifting lines. The vorticity generation mechanisms, the roll-up of the near wake and the resulting established far wake are described (i) qualitatively in terms of vortex dynamics using rotor polar plots and 3D visualizations; (ii) quantitatively using classical integral diagnostics. The power spectra measured by velocity probes in the wake are also presented. The analysis shows that the wake reaches a fully turbulent equilibrium state at a distance of about 30 diameters downstream. This work is supported by the Belgian french community F.R.S.-FNRS.

Rotor Wake/Stator Interaction Noise Prediction Code Technical Documentation and User's Manual

Science.gov (United States)

Topol, David A.; Mathews, Douglas C.

2010-01-01

This report documents the improvements and enhancements made by Pratt & Whitney to two NASA programs which together will calculate noise from a rotor wake/stator interaction. The code is a combination of subroutines from two NASA programs with many new features added by Pratt & Whitney. To do a calculation V072 first uses a semi-empirical wake prediction to calculate the rotor wake characteristics at the stator leading edge. Results from the wake model are then automatically input into a rotor wake/stator interaction analytical noise prediction routine which calculates inlet aft sound power levels for the blade-passage-frequency tones and their harmonics, along with the complex radial mode amplitudes. The code allows for a noise calculation to be performed for a compressor rotor wake/stator interaction, a fan wake/FEGV interaction, or a fan wake/core stator interaction. This report is split into two parts, the first part discusses the technical documentation of the program as improved by Pratt & Whitney. The second part is a user's manual which describes how input files are created and how the code is run.

Validation of a vortex ring wake model suited for aeroelastic simulations of floating wind turbines

DEFF Research Database (Denmark)

Vaal, J.B., de; Hansen, Martin Otto Laver; Moan, T.

2014-01-01

In order to evaluate aerodynamic loads on floating oshore wind turbines, advanced dynamic analysis tools are required. As a unied model that can represent both dynamic in ow and skewed in ow effects in it basic formulation, a wake model based on a vortex ring formulation is discussed. Such a model...... presents a good intermediate solution between computationally efficient but simple momentum balance methods and computationally expensive but complete computational fluid dynamics models. The model introduced is shown to be capable of modelling typical steady and unsteady test cases with reasonable...

Validation of a vortex ring wake model suited for aeroelastic simulations of floating wind turbines

International Nuclear Information System (INIS)

Vaal, J B de; Moan, T; Hansen, M O L

2014-01-01

In order to evaluate aerodynamic loads on floating offshore wind turbines, advanced dynamic analysis tools are required. As a unified model that can represent both dynamic inflow and skewed inflow effects in it basic formulation, a wake model based on a vortex ring formulation is discussed. Such a model presents a good intermediate solution between computationally efficient but simple momentum balance methods and computationally expensive but complete computational fluid dynamics models. The model introduced is shown to be capable of modelling typical steady and unsteady test cases with reasonable accuracy

Basic Energy Sciences Exascale Requirements Review. An Office of Science review sponsored jointly by Advanced Scientific Computing Research and Basic Energy Sciences, November 3-5, 2015, Rockville, Maryland

Energy Technology Data Exchange (ETDEWEB)

Windus, Theresa [Ames Lab., Ames, IA (United States); Banda, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Devereaux, Thomas [SLAC National Accelerator Lab., Menlo Park, CA (United States); White, Julia C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Antypas, Katie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Coffey, Richard [Argonne National Lab. (ANL), Argonne, IL (United States); Dart, Eli [Energy Sciences Network (ESNet), Berkeley, CA (United States); Dosanjh, Sudip [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gerber, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hack, James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Monga, Inder [Energy Sciences Network (ESNet), Berkeley, CA (United States); Papka, Michael E. [Argonne National Lab. (ANL), Argonne, IL (United States); Riley, Katherine [Argonne National Lab. (ANL), Argonne, IL (United States); Rotman, Lauren [Energy Sciences Network (ESNet), Berkeley, CA (United States); Straatsma, Tjerk [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wells, Jack [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baruah, Tunna [Univ. of Texas, El Paso, TX (United States); Benali, Anouar [Argonne National Lab. (ANL), Argonne, IL (United States); Borland, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Brabec, Jiri [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Carter, Emily [Princeton Univ., NJ (United States); Ceperley, David [Univ. of Illinois, Urbana-Champaign, IL (United States); Chan, Maria [Argonne National Lab. (ANL), Argonne, IL (United States); Chelikowsky, James [Univ. of Texas, Austin, TX (United States); Chen, Jackie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cheng, Hai-Ping [Univ. of Florida, Gainesville, FL (United States); Clark, Aurora [Washington State Univ., Pullman, WA (United States); Darancet, Pierre [Argonne National Lab. (ANL), Argonne, IL (United States); DeJong, Wibe [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deslippe, Jack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Dixon, David [Univ. of Alabama, Tuscaloosa, AL (United States); Donatelli, Jeffrey [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dunning, Thomas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fernandez-Serra, Marivi [Stony Brook Univ., NY (United States); Freericks, James [Georgetown Univ., Washington, DC (United States); Gagliardi, Laura [Univ. of Minnesota, Minneapolis, MN (United States); Galli, Giulia [Univ. of Chicago, IL (United States); Garrett, Bruce [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glezakou, Vassiliki-Alexandra [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gordon, Mark [Iowa State Univ., Ames, IA (United States); Govind, Niri [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gray, Stephen [Argonne National Lab. (ANL), Argonne, IL (United States); Gull, Emanuel [Univ. of Michigan, Ann Arbor, MI (United States); Gygi, Francois [Univ. of California, Davis, CA (United States); Hexemer, Alexander [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Isborn, Christine [Univ. of California, Merced, CA (United States); Jarrell, Mark [Louisiana State Univ., Baton Rouge, LA (United States); Kalia, Rajiv K. [Univ. of Southern California, Los Angeles, CA (United States); Kent, Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Klippenstein, Stephen [Argonne National Lab. (ANL), Argonne, IL (United States); Kowalski, Karol [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Krishnamurthy, Hulikal [Indian Inst. of Science, Bangalore (India); Kumar, Dinesh [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lena, Charles [Univ. of Texas, Austin, TX (United States); Li, Xiaosong [Univ. of Washington, Seattle, WA (United States); Maier, Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Markland, Thomas [Stanford Univ., CA (United States); McNulty, Ian [Argonne National Lab. (ANL), Argonne, IL (United States); Millis, Andrew [Columbia Univ., New York, NY (United States); Mundy, Chris [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nakano, Aiichiro [Univ. of Southern California, Los Angeles, CA (United States); Niklasson, A.M.N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Panagiotopoulos, Thanos [Princeton Univ., NJ (United States); Pandolfi, Ron [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Parkinson, Dula [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pask, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Perazzo, Amedeo [SLAC National Accelerator Lab., Menlo Park, CA (United States); Rehr, John [Univ. of Washington, Seattle, WA (United States); Rousseau, Roger [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sankaranarayanan, Subramanian [Argonne National Lab. (ANL), Argonne, IL (United States); Schenter, Greg [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Selloni, Annabella [Princeton Univ., NJ (United States); Sethian, Jamie [Univ. of California, Berkeley, CA (United States); Siepmann, Ilja [Univ. of Minnesota, Minneapolis, MN (United States); Slipchenko, Lyudmila [Purdue Univ., West Lafayette, IN (United States); Sternberg, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Stevens, Mark [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Summers, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sumpter, Bobby [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sushko, Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thayer, Jana [SLAC National Accelerator Lab., Menlo Park, CA (United States); Toby, Brian [Argonne National Lab. (ANL), Argonne, IL (United States); Tull, Craig [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Valeev, Edward [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Vashishta, Priya [Univ. of Southern California, Los Angeles, CA (United States); Venkatakrishnan, V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yang, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yang, Ping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zwart, Peter H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-02-03

Computers have revolutionized every aspect of our lives. Yet in science, the most tantalizing applications of computing lie just beyond our reach. The current quest to build an exascale computer with one thousand times the capability of today’s fastest machines (and more than a million times that of a laptop) will take researchers over the next horizon. The field of materials, chemical reactions, and compounds is inherently complex. Imagine millions of new materials with new functionalities waiting to be discovered — while researchers also seek to extend those materials that are known to a dizzying number of new forms. We could translate massive amounts of data from high precision experiments into new understanding through data mining and analysis. We could have at our disposal the ability to predict the properties of these materials, to follow their transformations during reactions on an atom-by-atom basis, and to discover completely new chemical pathways or physical states of matter. Extending these predictions from the nanoscale to the mesoscale, from the ultrafast world of reactions to long-time simulations to predict the lifetime performance of materials, and to the discovery of new materials and processes will have a profound impact on energy technology. In addition, discovery of new materials is vital to move computing beyond Moore’s law. To realize this vision, more than hardware is needed. New algorithms to take advantage of the increase in computing power, new programming paradigms, and new ways of mining massive data sets are needed as well. This report summarizes the opportunities and the requisite computing ecosystem needed to realize the potential before us. In addition to pursuing new and more complete physical models and theoretical frameworks, this review found that the following broadly grouped areas relevant to the U.S. Department of Energy (DOE) Office of Advanced Scientific Computing Research (ASCR) would directly affect the Basic Energy

TRANSVERSE MODES FOR FLAT INTER-BUNCH WAKES*

CERN Document Server

Burov, A

2013-01-01

If inter-bunch wake fields are flat, i.e. their variations over a bunch length can be neglected, all coherent modes have the same coupled-bunch structure, provided the bunches can be treated as identical by their inner qualities (train theorem). If a flat feedback is strong enough, the transverse modes are single-bunch, provided the inter-bunch wakes are also flat (damper theorem).

Determination of Wind Turbine Near-Wake Length Based on Stability Analysis

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming; Sarmast, Sasan

2014-01-01

A numerical study on the wake behind a wind turbine is carried out focusing on determining the length of the near-wake based on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier-Stokes equati......A numerical study on the wake behind a wind turbine is carried out focusing on determining the length of the near-wake based on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier...... of the study it is found that the amplification of specific waves (traveling structures) along the tip vortex spirals is responsible for triggering the instability leading to wake breakdown. The presence of unstable modes in the wake is related to the mutual inductance (vortex pairing) instability where...

Numerical study on wake characteristics of high-speed trains

Science.gov (United States)

Yao, Shuan-Bao; Sun, Zhen-Xu; Guo, Di-Long; Chen, Da-Wei; Yang, Guo-Wei

2013-12-01

Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of unsteady Reynold-averaged Navier-Stokes (URANS) and detached eddy simulation (DES) are utilized, respectively. Results reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

CSR Wake for a Short Magnet in Ultra-Relativistic Limit

International Nuclear Information System (INIS)

Emma, Paul J

2002-01-01

Using results for the CSR wake in a short magnet [1] we obtain expressions for the wake in the limit of very large values of the relativistic factor γ, γ → ∞, for both the entrance and exit of the magnet. The analytical results are illustrated with numerical computation of the wakes, energy loss and energy spread for magnets of different lengths

Comparison of Engineering Wake Models with CFD Simulations

DEFF Research Database (Denmark)

Andersen, Søren Juhl; Sørensen, Jens Nørkær; Ivanell, S.

2014-01-01

The engineering wake models by Jensen [1] and Frandsen et al. [2] are assessed for different scenarios simulated using Large Eddy Simulation and the Actuator Line method implemented in the Navier-Stokes equations. The scenarios include the far wake behind a single wind turbine, a long row of turb...

What's hot, what's new in basic science: report from the American Transplant Congress 2015.

Science.gov (United States)

Heeger, P S

2015-11-01

Research reports presented at the American Transplant Congress 2015 provided an array of basic science findings of relevance to the transplant community. Among key themes is the concept that ischemia-reperfusion injury and early posttransplantation inflammation is linked to adaptive alloimmunity and transplant injury. Molecular and cellular mechanisms contributing to these interactions were highlighted. The relevance of understanding how blocking costimulation, including CD40/CD154 interactions, affects various aspects of the alloimmune response was enhanced by the description of preclinical studies demonstrating efficacy of a unique, blocking anti-CD40 monoclonal antibody that could potentially be used in humans. The identification of mechanisms underlying interactions among T cell subsets and B cells, including follicular helper T cells, regulatory T cells, effector B cells, and regulatory B cells, provides multiple previously unrecognized targets for future therapeutic interventions. Additional reports of interest include novel insights into effects of the gut microbiome on graft survival and the ability to differentiate insulin-secreting, islet-like cells from induced pluripotent stem cells. Overall, the reported basic science findings from American Transplant Congress 2015 add to the fundamental understanding of innate and adaptive alloimmunity and provide novel and testable hypotheses that have the potential to be translated into improved clinical care of transplant patients. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Wake Field of the e-Cloud

International Nuclear Information System (INIS)

Heifets, Samuel A

2001-01-01

The wake field of the cloud is derived analytically taking into account the finite size of the cloud and nonlinearity of the electron motion. The analytic expression for the effective transverse wake field caused by the electron cloud in a positron storage ring is derived. The derivation includes the frequency spread in the cloud, which is the main effect of the nonlinearity of electron motion in the cloud. This approach allows calculation of the Q-factor and study the tune spread in a bunch

The bestial feminine in Finnegans Wake

OpenAIRE

Lovejoy, Laura

2017-01-01

Female characters frequently appear as animals in the unstable universe of James Joyce’s a Finnegans Wake. What Kimberly Devlin terms “the male tendency to reduce women to the level of the beast” is manifest in Finnegans Wake on a large scale. From the hen pecking at a dung heap which we suppose is a manifestation of matriarch Anna Livia Plurabelle, to the often lascivious pig imagery (reminiscent of Bloom’s experience with brothel-keeper Bella in the “Circe” episode of Ulysses) associated wi...

Virtual laboratory learning media development to improve science literacy skills of mechanical engineering students on basic physics concept of material measurement

Science.gov (United States)

Jannati, E. D.; Setiawan, A.; Siahaan, P.; Rochman, C.

2018-05-01

This study aims to determine the description of virtual laboratory learning media development to improve science literacy skills of Mechanical Engineering students on the concept of basic Physics. Quasi experimental method was employed in this research. The participants of this research were first semester students of mechanical engineering in Majalengka University. The research instrument was readability test of instructional media. The results of virtual laboratory learning media readability test show that the average score is 78.5%. It indicates that virtual laboratory learning media development are feasible to be used in improving science literacy skill of Mechanical Engineering students in Majalengka University, specifically on basic Physics concepts of material measurement.

Determination of Wind Turbine Near-Wake Length Based on Stability Analysis

International Nuclear Information System (INIS)

Sørensen, Jens N; Mikkelsen, Robert; Sarmast, Sasan; Ivanell, Stefan; Henningson, Dan

2014-01-01

A numerical study on the wake behind a wind turbine is carried out focusing on determining the length of the near-wake based on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier-Stokes equations using the actuator line (ACL) method. The wake is perturbed by applying stochastic or harmonic excitations in the neighborhood of the tips of the blades. The flow field is then analyzed to obtain the stability properties of the tip vortices in the wake of the wind turbine. As a main outcome of the study it is found that the amplification of specific waves (traveling structures) along the tip vortex spirals is responsible for triggering the instability leading to wake breakdown. The presence of unstable modes in the wake is related to the mutual inductance (vortex pairing) instability where there is an out-of-phase displacement of successive helix turns. Furthermore, using the non-dimensional growth rate, it is found that the pairing instability has a universal growth rate equal to π/2. Using this relationship, and the assumption that breakdown to turbulence occurs once a vortex has experienced sufficient growth, we provide an analytical relationship between the turbulence intensity and the stable wake length. The analysis leads to a simple expression for determining the length of the near wake. This expression shows that the near wake length is inversely proportional to thrust, tip speed ratio and the logarithmic of the turbulence intensity

Why Does REM Sleep Occur? A Wake-up Hypothesis

OpenAIRE

Dr. W. R. eKlemm

2011-01-01

Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses REM to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, 1) when first going to sleep, the brain plunges into Stage N3 (formerly ca...

Influence of short rear end tapers on the wake of a simplified square-back vehicle: wake topology and rear drag

Science.gov (United States)

Perry, Anna-Kristina; Pavia, Giancarlo; Passmore, Martin

2016-11-01

As vehicle manufacturers work to reduce energy consumption of all types of vehicles, external vehicle aerodynamics has become increasingly important. Whilst production vehicle shape optimisation methods are well developed, the need to make further advances requires deeper understanding of the highly three-dimensional flow around bluff bodies. In this paper, the wake flow of a generic bluff body, the Windsor body, based on a square-back car geometry, was investigated by means of balance measurements, surface pressure measurements and 2D particle image velocimetry planes. Changes in the wake topology are triggered by the application of short tapers (4 % of the model length) to the top and bottom edges of the base, representing a shape optimisation that is realistic for many modern production vehicles. The base drag is calculated and correlated with the aerodynamic drag data. The results not only show the effectiveness of such small devices in modifying the time average topology of the wake but also shed some light on the effects produced by different levels of upwash and downwash on the bi-stable nature of the wake itself.

First Results from ARTEMIS, A New Two-Spacecraft Lunar Mission: Counter-Streaming Plasma Populations in the Lunar Wake

Science.gov (United States)

Halekas, J. S.; Angelopoulos, V.; Sibeck, D. G.; Khurana, K. K.; Russell, C. T.; Delory, G. T.; Farrell, W. M.; McFadden, J. P.; Bonnell, J. W.; Larson, D.;

Fast wake measurements with LiDAR at Risø test field

DEFF Research Database (Denmark)

Bingöl, Ferhat; Trujillo, J.J.; Mann, Jakob

2008-01-01

. Downstream wind speed can be quantified spatially in one and two dimensions. Data analysis allows us to identify the wake transversal position, thus enabling us to quantify the wake meandering as well as the instantaneous wake expansion expressed in a meandering frame of reference. The experimental results...

A study of the academic performance of medical students in the comprehensive examination of the basic sciences according to the indices of emotional intelligence and educational status

Science.gov (United States)

Moslehi, Mohsen; Samouei, Rahele; Tayebani, Tayebeh; Kolahduz, Sima

2015-01-01

Background: Considering the increasing importance of emotional intelligence (EI) in different aspects of life, such as academic achievement, the present survey is aimed to predict academic performance of medical students in the comprehensive examination of the basic sciences, according to the indices of emotional intelligence and educational status. Materials and Methods: The present survey is a descriptive, analytical, and cross-sectional study performed on the medical students of Isfahan, Tehran, and Mashhad Universities of Medical Sciences. Sampling the universities was performed randomly after which selecting the students was done, taking into consideration the limitation in their numbers. Based on the inclusion criteria, all the medical students, entrance of 2005, who had attended the comprehensive basic sciences examination in 2008, entered the study. The data collection tools included an Emotional Intelligence Questionnaire (standardized in Isfahan), the average score of the first to fifth semesters, total average of each of the five semesters, and the grade of the comprehensive basic sciences examination. The data were analyzed through stepwise regression coefficient by SPSS software version 15. Results: The results indicated that the indicators of independence from an emotional intelligence test and average scores of the first and third academic semesters were significant in predicting the students’ academic performance in the comprehensive basic sciences examination. Conclusion: According to the obtained results, the average scores of students, especially in the earlier semesters, as well as the indicators of independence and the self-esteem rate of students can influence their success in the comprehensive basic sciences examination. PMID:26430693

Boat, wake, and wave real-time simulation

Science.gov (United States)

Świerkowski, Leszek; Gouthas, Efthimios; Christie, Chad L.; Williams, Owen M.

2009-05-01

We describe the extension of our real-time scene generation software VIRSuite to include the dynamic simulation of small boats and their wakes within an ocean environment. Extensive use has been made of the programmabilty available in the current generation of GPUs. We have demonstrated that real-time simulation is feasible, even including such complexities as dynamical calculation of the boat motion, wake generation and calculation of an FFTgenerated sea state.

Cylinder wakes in flowing soap films

International Nuclear Information System (INIS)

Vorobieff, P.; Ecke, R.E.; Vorobieff, P.

1999-01-01

We present an experimental characterization of cylinder wakes in flowing soap films. From instantaneous velocity and thickness fields, we find the vortex-shedding frequency, mean-flow velocity, and mean-film thickness. Using the empirical relationship between the Reynolds and Strouhal numbers obtained for cylinder wakes in three dimensions, we estimate the effective soap-film viscosity and its dependence on film thickness. We also compare the decay of vorticity with that in a simple Rankine vortex model with a dissipative term to account for air drag. copyright 1999 The American Physical Society

Basic Research in the United States.

Science.gov (United States)

Handler, Philip

1979-01-01

Presents a discussion of the development of basic research in the U.S. since World War II. Topics include the creation of the federal agencies, physics and astronomy, chemistry, earth science, life science, the environment, and social science. (BB)

How much basic science content do second-year medical students remember from their first year?

Science.gov (United States)

Schneid, Stephen D; Pashler, Hal; Armour, Chris

2018-01-23

While most medical students generally perform well on examinations and pass their courses during the first year, we do not know how much basic science content they retain at the start of their second year and how that relates to minimal competency set by the faculty. In the fall of 2014, before starting their second-year courses, 27 medical students volunteered to participate in a study of long-term retention of the basic sciences by taking a "retention exam" after a delay of 5-11 months. The overall mean performance when the students initially answered the 60 multiple choice questions (MCQs) was 82.8% [standard deviation (SD) = 7.4%], which fell to 50.1% (SD = 12.1%) on the retention exam. This gave a mean retention of 60.4% (SD = 12.8%) with the retention for individual students ranging from 37 to 81%. The majority of students (23/27; 85%) fell below the minimal level of competency to start their second year. Medical educators should be more aware of the significant amount of forgetting that occurs during training and make better use of instructional strategies that promote long-term learning such as retrieval practice, interleaving, and spacing.

Landscape of Innovation for Cardiovascular Pharmaceuticals: From Basic Science to New Molecular Entities.

Science.gov (United States)

Beierlein, Jennifer M; McNamee, Laura M; Walsh, Michael J; Kaitin, Kenneth I; DiMasi, Joseph A; Ledley, Fred D

2017-07-01

This study examines the complete timelines of translational science for new cardiovascular therapeutics from the initiation of basic research leading to identification of new drug targets through clinical development and US Food and Drug Administration (FDA) approval of new molecular entities (NMEs) based on this research. This work extends previous studies by examining the association between the growth of research on drug targets and approval of NMEs associated with these targets. Drawing on research on innovation in other technology sectors, where technological maturity is an important determinant in the success or failure of new product development, an analytical model was used to characterize the growth of research related to the known targets for all 168 approved cardiovascular therapeutics. Categorizing and mapping the technological maturity of cardiovascular therapeutics reveal that (1) there has been a distinct transition from phenotypic to targeted methods for drug discovery, (2) the durations of clinical and regulatory processes were significantly influenced by changes in FDA practice, and (3) the longest phase of the translational process was the time required for technology to advance from initiation of research to a statistically defined established point of technology maturation (mean, 30.8 years). This work reveals a normative association between metrics of research maturation and approval of new cardiovascular therapeutics and suggests strategies for advancing translational science by accelerating basic and applied research and improving the synchrony between the maturation of this research and drug development initiatives. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

Age-related changes in sleep-wake rhythm in dog.

Science.gov (United States)

Takeuchi, Takashi; Harada, Etsumori

2002-10-17

To investigate a sleep-wake rhythm in aged dogs, a radio-telemetry monitoring was carried out for 24 h. Electrodes and telemetry device were surgically implanted in four aged dogs (16-18 years old) and four young dogs (3-4 years old). Electroencephalogram (EEG), electromyogram (EMG) and electrocardiogram (ECG) were recorded simultaneously as parameters to determine vigilance states and an autonomic nervous function. Wakefulness, slow wave sleep (SWS) and paradoxical sleep (PS) were identified according to the EEG and EMG pattern. We also examined whether absolute powers and the low frequency-to-high frequency ratio (LF/HF) derived from the heart rate variability power spectrum could detect shifts in autonomic balance correlated with aging. The aged dogs showed a marked reduction of PS and a fragmentation of wakefulness in the daytime and a sleep disruption in the night. The pattern of 24 h sleep and waking was dramatically altered in the aged dog. It was characterized by an increase in the total amount of time spent in SWS during the daytime followed by an increasing of time spent in wakefulness during the night. Furthermore, LF/HF ratio showed a very low amplitude of variance throughout the day in the aged dog. These results suggest that the aged dog is a useful model to investigate sleep disorders in human such as daytime drowsiness, difficulties in sleep maintenance. The abnormality in sleep-wake cycle might be reflected by the altered autonomic balance in the aged dogs.

Accurate wind farm development and operation. Advanced wake modelling

Energy Technology Data Exchange (ETDEWEB)

Brand, A.; Bot, E.; Ozdemir, H. [ECN Unit Wind Energy, P.O. Box 1, NL 1755 ZG Petten (Netherlands); Steinfeld, G.; Drueke, S.; Schmidt, M. [ForWind, Center for Wind Energy Research, Carl von Ossietzky Universitaet Oldenburg, D-26129 Oldenburg (Germany); Mittelmeier, N. REpower Systems SE, D-22297 Hamburg (Germany))

2013-11-15

The ability is demonstrated to calculate wind farm wakes on the basis of ambient conditions that were calculated with an atmospheric model. Specifically, comparisons are described between predicted and observed ambient conditions, and between power predictions from three wind farm wake models and power measurements, for a single and a double wake situation. The comparisons are based on performance indicators and test criteria, with the objective to determine the percentage of predictions that fall within a given range about the observed value. The Alpha Ventus site is considered, which consists of a wind farm with the same name and the met mast FINO1. Data from the 6 REpower wind turbines and the FINO1 met mast were employed. The atmospheric model WRF predicted the ambient conditions at the location and the measurement heights of the FINO1 mast. May the predictability of the wind speed and the wind direction be reasonable if sufficiently sized tolerances are employed, it is fairly impossible to predict the ambient turbulence intensity and vertical shear. Three wind farm wake models predicted the individual turbine powers: FLaP-Jensen and FLaP-Ainslie from ForWind Oldenburg, and FarmFlow from ECN. The reliabilities of the FLaP-Ainslie and the FarmFlow wind farm wake models are of equal order, and higher than FLaP-Jensen. Any difference between the predictions from these models is most clear in the double wake situation. Here FarmFlow slightly outperforms FLaP-Ainslie.

Wake flow control using a dynamically controlled wind turbine

Science.gov (United States)

Castillo, Ricardo; Wang, Yeqin; Pol, Suhas; Swift, Andy; Hussain, Fazle; Westergaard, Carsten; Texas Tech University Team

2016-11-01

A wind tunnel based "Hyper Accelerated Wind Farm Kinematic-Control Simulator" (HAWKS) is being built at Texas Tech University to emulate controlled wind turbine flow physics. The HAWKS model turbine has pitch, yaw and speed control which is operated in real model time, similar to that of an equivalent full scale turbine. Also, similar to that of a full scale wind turbine, the controls are developed in a Matlab Simulink environment. The current diagnostic system consists of power, rotor position, rotor speed measurements and PIV wake characterization with four cameras. The setup allows up to 7D downstream of the rotor to be mapped. The purpose of HAWKS is to simulate control strategies at turnaround times much faster than CFD and full scale testing. The fundamental building blocks of the simulator have been tested, and demonstrate wake steering for both static and dynamic turbine actuation. Parameters which have been studied are yaw, rotor speed and combinations hereof. The measured wake deflections for static yaw cases are in agreement with previously reported research implying general applicability of the HAWKS platform for the purpose of manipulating the wake. In this presentation the general results will be introduced followed by an analysis of the wake turbulence and coherent structures when comparing static and dynamic flow cases. The outcome of such studies could ultimately support effective wind farm wake flow control strategies. Texas Emerging Technology Fund (ETF).

The DLR project Wirbelschleppe. Detecting, characterizing, controlling, attenuating, understanding, and predicting aircraft wake vortices

Energy Technology Data Exchange (ETDEWEB)

Holzaepfel, F. (ed.)

2008-07-01

This collection of reports presents an excerpt of the investigations that were performed in the framework of the DLR Projekt Wirbelschleppe. A similar sample of reports was presented as part of three dedicated wake vortex sessions accomplished at the 1{sup st} European Air and Space Conference (CEAS 2007) and Deutscher Luft- und Raumfahrtkongress 2007 in Berlin. The Projekt Wirbelschleppe was conducted in two phases in the time frame from 1999 to 2007 with the five contributing DLR Institutes: Institute of Atmospheric Physics, Institute of Aerodynamics and Flow Technology, Institute of Flight Systems, Institute of Flight Guidance, Institute of Robotics and Mechatronics and the Institute of Aeronautics and Astronautics of the University of Technology Berlin. The project unified a multitude of different aspects and disciplines of wake vortex research which can be characterized by four main themes: - minimization of wake vortices by measures at the aircraft; - development and demonstration of a system for wake vortex prediction and observation; - airborne wake vortex detection and active control; - integration of systems into air traffic control. The Projekt Wirbelschleppe greatly benefited from the European projects AWIATOR, ATC-Wake, Credos, C-Wake, Eurowake, FAR-Wake, FLYSAFE, I-Wake, S-Wake, WakeNet, WakeNet2-Europe, WakeNet3-Europe, and Wavenc. DLR's wake vortex activities will be continued in the Projekt Wetter and Fliegen (2008-2011): Because the current compilation represents only a limited extract of the accomplished work, it is completed by a list of references emerging from the project. (orig.)

Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Long

Science.gov (United States)

Czeisler, Charles A.; Barger, Laura K.; Wright, Kenneth P., Jr.; Ronda, Joseph

2009-01-01

Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Long (Sleep-Long) will examine the effects of spaceflight and ambient light exposure on the sleep-wake cycles of the crew members during long-duration stays on the space station.

NASA AVOSS Fast-Time Wake Prediction Models: User's Guide

Science.gov (United States)

Ahmad, Nash'at N.; VanValkenburg, Randal L.; Pruis, Matthew

2014-01-01

The National Aeronautics and Space Administration (NASA) is developing and testing fast-time wake transport and decay models to safely enhance the capacity of the National Airspace System (NAS). The fast-time wake models are empirical algorithms used for real-time predictions of wake transport and decay based on aircraft parameters and ambient weather conditions. The aircraft dependent parameters include the initial vortex descent velocity and the vortex pair separation distance. The atmospheric initial conditions include vertical profiles of temperature or potential temperature, eddy dissipation rate, and crosswind. The current distribution includes the latest versions of the APA (3.4) and the TDP (2.1) models. This User's Guide provides detailed information on the model inputs, file formats, and the model output. An example of a model run and a brief description of the Memphis 1995 Wake Vortex Dataset is also provided.

An LES study of vertical-axis wind turbine wakes aerodynamics

Science.gov (United States)

Abkar, Mahdi; Dabiri, John O.

2016-11-01

In this study, large-eddy simulation (LES) combined with a turbine model is used to investigate the structure of the wake behind a vertical-axis wind turbine (VAWT). In the simulations, a recently developed minimum dissipation model is used to parameterize the subgrid-scale stress tensor, while the turbine-induced forces are modeled with an actuator-line technique. The LES framework is first tested in the simulation of the wake behind a model straight-bladed VAWT placed in the water channel, and then used to study the wake structure downwind of a full-scale VAWT sited in the atmospheric boundary layer. In particular, the self-similarity of the wake is examined, and it is found that the wake velocity deficit is well characterized by a two-dimensional elliptical Gaussian distribution. By assuming a self-similar Gaussian distribution of the velocity deficit, and applying mass and momentum conservation, an analytical model is developed and tested to predict the maximum velocity deficit downwind of the turbine.

Wake effect on a uniform flow behind wind-turbine model

Science.gov (United States)

Okulov, V. L.; Naumov, I. V.; Mikkelsen, R. F.; Sørensen, J. N.

2015-06-01

LDA experiments were carried out to study the development of mean velocity profiles of the very far wake behind a wind turbine model in a water flume. The model of the rotor is placed in a middle of the flume. The initial flume flow is subjected to a very low turbulence level, limiting the influence of external disturbances on the development of the inherent wake instability. The rotor is three-bladed and designed using Glauert's optimum theory at a tip speed ratio λ = 5 with a constant of the lift coefficient along the span, CL= 0.8. The wake development has been studied in the range of tip speed ratios from 3 to 9, and at different cross-sections from 10 to 100 rotor radii downstream from the rotor. By using regression techniques to fit the velocity profiles it was possible to obtain accurate velocity deficits and estimate length scales of the wake attenuation. The data are compared with different analytical models for wind turbine wakes.

Robust lidar-based closed-loop wake redirection for wind farm control

NARCIS (Netherlands)

Raach, Steffen; Boersma, S.; van Wingerden, J.W.; Schlipf, David; Cheng, Po Wen; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

2017-01-01

Wind turbine wake redirection is a promising concept for wind farm control to increase the total power of a wind farm. Further, the concept aims to avoid partial wake overlap on a downwind wind turbine and hence aims to decrease structural loads. Controller for wake redirection need to account

Dynamics of plasma ions motion in ultra-intense laser-excited plasma wakes

International Nuclear Information System (INIS)

Zhou Suyun; Li Jing

2013-01-01

The effects of heavy ions and protons motion in an ultra-intense laser-driven plasma wake are compared by rebuilding a plasma wake model. It is shown that with the same laser and plasma background electron density n 0 , the heavy ions' motion suppresses wake-field resonant excitation less than the protons' motion in their own plasma wake. Though heavy ions obtain more kinetic energy from the plasma wake, its energy density is less than that of the protons due to the ion density being far less than the proton density. As a result, the total energy of heavy ions obtained from the wake-field is far less than that of protons. The dependence of the kinetic energy and the energy density of protons and heavy ions on n 0 is discussed. (paper)

Joyce the Deconstructionist: Finnegans Wake in Context

Directory of Open Access Journals (Sweden)

Zangouei J.

2012-01-01

Full Text Available Had Finnegans Wake not been written, some seminal post-1950s innovations in the field of modern literary theory and criticism would have been impossible. James Joyce, who seems to have inspiringly influenced the entire sphere of modern literary theory and criticism greatly, is a pioneer of deconstruction too. His last novel, which reflects his deconstructive tendencies, has played a seminal role in the formation of 20th century deconstruction, and comprises an inchoate mass of implicit ideas on the subject. It was perhaps not until Jacques Derrida and his deconstruction techniques that the theory implied by Finnegans Wake really came into focus. This article seeks to delineate Derrida’s theory of deconstruction as well as Joyce's deconstructive aesthetics; and taking a diachronic approach to literary theory and criticism it glances at Finnegans Wake in the light of deconstruction.

Transforming Defense Basic Research Strategy

National Research Council Canada - National Science Library

Fountain, Augustus W

2004-01-01

... technologies for development. With a basic research budget less than half that of the National Science Foundation and a mere fraction that of the NIH the DoD can no longer afford to pursue lofty science education goals...

Learning to classify wakes from local sensory information

Science.gov (United States)

Alsalman, Mohamad; Colvert, Brendan; Kanso, Eva; Kanso Team

2017-11-01

Aquatic organisms exhibit remarkable abilities to sense local flow signals contained in their fluid environment and to surmise the origins of these flows. For example, fish can discern the information contained in various flow structures and utilize this information for obstacle avoidance and prey tracking. Flow structures created by flapping and swimming bodies are well characterized in the fluid dynamics literature; however, such characterization relies on classical methods that use an external observer to reconstruct global flow fields. The reconstructed flows, or wakes, are then classified according to the unsteady vortex patterns. Here, we propose a new approach for wake identification: we classify the wakes resulting from a flapping airfoil by applying machine learning algorithms to local flow information. In particular, we simulate the wakes of an oscillating airfoil in an incoming flow, extract the downstream vorticity information, and train a classifier to learn the different flow structures and classify new ones. This data-driven approach provides a promising framework for underwater navigation and detection in application to autonomous bio-inspired vehicles.

Traumatic brain injury and disturbed sleep and wakefulness.

Science.gov (United States)

Baumann, Christian R

2012-09-01

Traumatic brain injury is a frequent condition worldwide, and sleep-wake disturbances often complicate the course after the injuring event. Current evidence suggests that the most common sleep-wake disturbances following traumatic brain injury include excessive daytime sleepiness and posttraumatic hypersomnia, that is, increased sleep need per 24 h. The neuromolecular basis of posttraumatic sleep pressure enhancement is not entirely clear. First neuropathological and clinical studies suggest that impaired hypocretin (orexin) signalling might contribute to sleepiness, but direct or indirect traumatic injury also to other sleep-wake modulating systems in the brainstem and the mesencephalon is likely. Posttraumatic insomnia may be less common than posttraumatic sleepiness, but studies on its frequency revealed conflicting results. Furthermore, insomnia is often associated with psychiatric comorbidities, and some patients with posttraumatic disruption of their circadian rhythm may be misdiagnosed as insomnia patients. The pathophysiology of posttraumatic circadian sleep disorders remains elusive; however, there is some evidence that reduced evening melatonin production due to traumatic brain damage may cause disruption of circadian regulation of sleep and wakefulness.

Diffraction of an impulsive line source with wake

International Nuclear Information System (INIS)

Ayub, M; Naeem, A; Nawaz, Rab

2010-01-01

The problem of diffraction due to an impulse line source by an absorbing half-plane with wake using Myres' impedance condition (Myers 1980 J. Sound Vib. 71 429-34) in the presence of a subsonic fluid flow is studied. The time dependence of the field requires a temporal Fourier transform in addition to the spatial Fourier transform. The solution of the problem in the presence of wake is obtained by using Greens' function method, Fourier transform, the Wiener-Hopf technique and the modified stationary phase method. Expressions for the total far field for the trailing edge (wake present) situation are given. It is observed that the field produced by the Kutta-Joukowski condition will be substantially in excess of the field when this condition is ignored. Finally, a simple procedure is devised to calculate the inverse temporal Fourier transform. The solution for the leading edge situation can be obtained if the wake, and consequently a Kutta-Joukowski edge condition, is ignored. This can also be seen from the numerical results.

Determining the Correlation Between Language Scores Obtained by Medical Students in their University Entrance and Comprehensive Medical Basic Sciences Exams

Directory of Open Access Journals (Sweden)

Majid Ahmadi

2009-06-01

Full Text Available Background and Purpose: Some professors and educators in the field of English language believe that the high grades attained by medical students in their Comprehensive Medical Basic Sciences Exam (CMBSE are mainly a result of the students prior fluency in the language before entering medical colleges; they are of the opinion that these grades are not necessarily a result of the combined effort of the English teachers and students in language courses at the university. This research aimsat determining the correlation between the level of fluency in English of medical students prior to university entrance and the grades obtained by them in their CMBSE after 3 terms of language courses at the university.Methods: Seven of the major and smaller universities of medical sciences were selected. The language scores of 2426 students admitted to these universities during the three academic years of 1999 to 2002 in both the National University Entrance Examination (NUEE and the Comprehensive Medical Basic Sciences Exam (CMBSE were obtained from their related universities and from the secretariat of the Council of Medical Basic Sciences Education respectively. The language scores of each studentobtained in both NUEE and CMBSE were then matched. The related SPSS software was used to assess the level of correlation between these two groups of language scores for the students of each university, for each academic year and semester and also the overall score for the three years.Results: Overall a positive and moderately significant correlation was found between the NUEE language scores and those of the CMBSE of the students of the universities studied (P<0/001; R=443%. The level of correlation for the various universities studied differed (Max. 69%, min.27%.A comparison of the means of these two groups of scores also confirmed this correlation.Conclusion: students’ grades The NUEE language score was not the only factor affecting the student’s CMBSE score

Aircraft Wake Vortex Deformation in Turbulent Atmosphere

OpenAIRE

Hennemann, Ingo; Holzaepfel, Frank

2007-01-01

Large-scale distortion of aircraft wake vortices appears to play a crucial role for aircraft safety during approach and landing. Vortex distortion is investigated based on large eddy simulations of wake vortex evolution in a turbulent atmosphere. A vortex identification method is developed that can be adapted to the vortex scales of interest. Based on the identified vortex center tracks, a statistics of vortex curvature radii is established. This statistics constitutes the basis for understan...

Oscillatory wake potential with exchange-correlation in plasmas

Science.gov (United States)

Khan, Arroj A.; Zeba, I.; Jamil, M.; Asif, M.

2017-12-01

The oscillatory wake potential of a moving test charge is studied in quantum dusty plasmas. The plasma system consisting of electrons, ions and negatively charged dust species is embedded in an ambient magnetic field. The modified equation of dispersion is derived using a Quantum Hydrodynamic Model for magnetized plasmas. The quantum effects are inculcated through Fermi degenerate pressure, the tunneling effect and exchange-correlation effects. The study of oscillatory wake is important to know the existence of silence zones in space and astrophysical objects as well as for crystal formation. The graphical description of the potential depicts the significance of the exchange and correlation effects arising through spin and other variables on the wake potential.

A three states sleep-waking model

International Nuclear Information System (INIS)

Comte, J.C.; Schatzman, M.; Ravassard, P.; Luppi, P.H.; Salin, P.A.

2006-01-01

The mechanisms underlying the sleep-states periodicity in animals are a mystery of biology. Recent studies identified a new neuronal population activated during the slow wave sleep (SWS) in the ventral lateral preoptic area of the hypothalamus. Interactions between this neuronal population and the others populations implicated in the vigilance states (paradoxical sleep (PS) and wake (W)) dynamics are not determined. Thus, we propose here a sleep-waking theoretical model that depicts the potential interactions between the neuronal populations responsible for the three vigilance states. First, we pooled data from previous papers regarding the neuronal populations firing rate time course and characterized statistically the experimental hypnograms. Then, we constructed a nonlinear differential equations system describing the neuronal populations activity time course. A simple rule playing the firing threshold role applied to the model allows to construct a theoretical hypnogram. A random modulation of the neuronal activity, shows that theoretical hypnograms present a dynamics close to the experimental observations. Furthermore, we show that the wake promoting neurons activity can predict the next SWS episode duration

The Learning of Science Basic Concept by Using Scientifiq Inquiry to Improve Student’s Thinking, Working, and Scientific Attitude Abilities

Directory of Open Access Journals (Sweden)

Wachidatul Linda Yuhanna

2016-03-01

Full Text Available This research was a classroom action research which was conducted intwo cycles, each cycle consists of planning, implementing, observing, and reflecting. The data used was quantitative data on student observation sheet instruments. The Results of the study which were obtained from the first cycle showed about the students’ thinking skills and scientific works. They were categorized as excellent 18.18%, good 22.73%, enough 52.27%, and sufficiently less 6.82%. As for the scientific attitude with a very active category of 11.36%, 43.18% and less active 45.45%. It has not reached indicators of success, so it was necessary to cycle II. Cycle II demonstrated the excellent category 38.63%, 36.36% good, good enough18.18% and less 6.81%. While the scientific attitude in the cycle II was an active attitude 29.54%, active 54.54%, inactive 15.91%. These results show an increase from the cycle I to cycle II. The conclusion of this study were: 1 learning the basic concepts of science with scientific inquiry in students can be conducible applied.2 Learning the basic concepts of science with scientific inquiry can improve thinking ability and scientific work and students’ scientific attitude. 3 Learning the basic concepts of science with scientific inquiry be able to explore and develop student creativity in designing simple experiments which can be applied in primary schools.

malERA: An updated research agenda for basic science and enabling technologies in malaria elimination and eradication

Science.gov (United States)

2017-01-01

Basic science holds enormous power for revealing the biological mechanisms of disease and, in turn, paving the way toward new, effective interventions. Recognizing this power, the 2011 Research Agenda for Malaria Eradication included key priorities in fundamental research that, if attained, could help accelerate progress toward disease elimination and eradication. The Malaria Eradication Research Agenda (malERA) Consultative Panel on Basic Science and Enabling Technologies reviewed the progress, continuing challenges, and major opportunities for future research. The recommendations come from a literature of published and unpublished materials and the deliberations of the malERA Refresh Consultative Panel. These areas span multiple aspects of the Plasmodium life cycle in both the human host and the Anopheles vector and include critical, unanswered questions about parasite transmission, human infection in the liver, asexual-stage biology, and malaria persistence. We believe an integrated approach encompassing human immunology, parasitology, and entomology, and harnessing new and emerging biomedical technologies offers the best path toward addressing these questions and, ultimately, lowering the worldwide burden of malaria. PMID:29190277

Wind Turbine Wake-Redirection Control at the Fishermen's Atlantic City Windfarm: Preprint

Energy Technology Data Exchange (ETDEWEB)

Churchfield, M.; Fleming, P.; Bulder, B.; White, S.

2015-05-06

In this paper, we will present our work towards designing a control strategy to mitigate wind turbine wake effects by redirecting the wakes, specifically applied to the Fishermen’s Atlantic City Windfarm (FACW), proposed for deployment off the shore of Atlantic City, New Jersey. As wind turbines extract energy from the air, they create low-speed wakes that extend behind them. Full wake recovery Full wake recovery to the undisturbed wind speed takes a significant distance. In a wind energy plant the wakes of upstream turbines may travel downstream to the next row of turbines, effectively subjecting them to lower wind speeds, meaning these waked turbines will produce less power.

Rotor wake and flow analysis using a coupled Eulerian–Lagrangian method

Directory of Open Access Journals (Sweden)

Yongjie Shi

2016-01-01

Full Text Available A coupled Eulerian–Lagrangian methodology was developed in this paper in order to provide an efficient and accurate tool for rotor wake and flow prediction. A Eulerian-based Reynolds-averaged Navier–Stokes (RANS solver was employed to simulate the grid-covered near-body zone, and a grid-free Lagrangian-based viscous wake method (VWM was implemented to model the complicated rotor-wake dynamics in the off-body wake zone. A carefully designed coupling strategy was developed to pass the flow variables between two solvers. A sample case of a forward flying rotor was performed first in order to show the capabilities of the VWM for wake simulations. Next, the coupled method was applied to rotors in several representative flight conditions. Excellent agreement regarding wake geometry, chordwise pressure distribution and sectional normal force with available experimental data demonstrated the validity of the method. In addition, a comparison with the full computational fluid dynamics (CFD method is presented to illustrate the efficiency and accuracy of the proposed coupled method.

Comparison of Wake models with data[Efficient Development of Offshore Windfarms

Energy Technology Data Exchange (ETDEWEB)

Rados, K. [Robert Gordon Univ., School of Engieering, Aberdeen, Scotland (United Kingdom); Larsen, G.; Barthelmie, R. [Risoe National Lab., Wind Energy Dept., Roskilde (Denmark); Schlez, W. [Garrad Hassan and Partners, Ltd., Bristol (United Kingdom); Lange, B. [Univ. of Oldenburg, Dept. of Energy and Semiconductor Research EHF, Oldenburg (Germany); Schepers, G.; Hegberg, T. [Netherlands Energy Research Foundation ECN, Solar and Wind Energy, Petten (NL); Magnusson, M. [Uppsala Univ., Dept. of Earth Sciences, Meterology, Uppsala (Sweden)

2002-03-01

A major objective of the ENDOW project is to evaluate the performance of wake models in offshore environments in order to ascertain the improvements required to enhance the prediction of power output within large offshore wind farms. The strategy for achieving this objective is to compare the performance of the models in a wide range of conditions which are expected to be encountered during turbine operation offshore. Six models of varying complexity have been evaluated initially against the Vindeby single wake data in where it was found that almost all of them overestimate the wake effects and also significant inconsistencies between the model predictions appeared in the near wake and turbulence intensity results. Based on the conclusions of that study, the wake modelling groups have already implemented a number of modifications to their original models. In the present paper, new single wake results are presented against experimental data at Vindeby and Bockstigen wind farms. Clearly, some of the model discrepancies previously observed in Vindeby cases have been smoothed and overall the performance is improved. (au)

E-Basics: Online Basic Training in Program Evaluation

Science.gov (United States)

Silliman, Ben

2016-01-01

E-Basics is an online training in program evaluation concepts and skills designed for youth development professionals, especially those working in nonformal science education. Ten hours of online training in seven modules is designed to prepare participants for mentoring and applied practice, mastery, and/or team leadership in program evaluation.…

[Platforms are needed for innovative basic research in ophthalmology].

Science.gov (United States)

Wang, Yi-qiang

2012-07-01

Basic research poses the cornerstone of technical innovation in all lines including medical sciences. Currently, there are shortages of professional scientists as well as technical supporting teams and facilities in the field of basic research of ophthalmology and visual science in China. Evaluation system and personnel policies are not supportive for innovative but high-risk-of-failure research projects. Discussion of reasons and possible solutions are given here to address these problems, aiming at promoting buildup of platforms hosting novel and important basic research in eye science in this country.

Making Basic Science Studies in Glaucoma More Clinically Relevant: The Need for a Consensus.

Science.gov (United States)

Toris, Carol B; Gelfman, Claire; Whitlock, Andy; Sponsel, William E; Rowe-Rendleman, Cheryl L

2017-09-01

Glaucoma is a chronic, progressive, and debilitating optic neuropathy that causes retinal damage and visual defects. The pathophysiologic mechanisms of glaucoma remain ill-defined, and there is an indisputable need for contributions from basic science researchers in defining pathways for translational research. However, glaucoma researchers today face significant challenges due to the lack of a map of integrated pathways from bench to bedside and the lack of consensus statements to guide in choosing the right research questions, techniques, and model systems. Here, we present the case for the development of such maps and consensus statements, which are critical for faster development of the most efficacious glaucoma therapy. We underscore that interrogating the preclinical path of both successful and unsuccessful clinical programs is essential to defining future research. One aspect of this is evaluation of available preclinical research tools. To begin this process, we highlight the utility of currently available animal models for glaucoma and emphasize that there is a particular need for models of glaucoma with normal intraocular pressure. In addition, we outline a series of discoveries from cell-based, animal, and translational research that begin to reveal a map of glaucoma from cell biology to physiology to disease pathology. Completion of these maps requires input and consensus from the global glaucoma research community. This article sets the stage by outlining various approaches to such a consensus. Together, these efforts will help accelerate basic science research, leading to discoveries with significant clinical impact for people with glaucoma.

Vertical axis wind turbine wake in boundary layer flow in a wind tunnel

Science.gov (United States)

Rolin, Vincent; Porté-Agel, Fernando

2016-04-01

A vertical axis wind turbine is placed in a boundary layer flow in a wind tunnel, and its wake is investigated. Measurements are performed using an x-wire to measure two components of velocity and turbulence statistics in the wake of the wind turbine. The study is performed at various heights and crosswind positions in order to investigate the full volume of the wake for a range of tip speed ratios. The velocity deficit and levels of turbulence in the wake are related to the performance of the turbine. The asymmetric incoming boundary layer flow causes the rate of recovery in the wake to change as a function of height. Higher shear between the wake and unperturbed flow occurs at the top edge of the wake, inducing stronger turbulence and mixing in this region. The difference in flow relative to the blades causes the velocity deficit and turbulence level to change as a function of crosswind position behind the rotor. The relative difference diminishes with increasing tip speed ratio. Therefore, the wake becomes more homogeneous as tip speed ratio increases.

Basics of Laser Physics For Students of Science and Engineering

CERN Document Server

Renk, Karl F

2012-01-01

Basics of Laser Physics provides an introductory presentation of the field of all types of lasers. It contains a general description of the laser, a theoretical treatment and a characterization of its operation as it deals with gas, solid state, free-electron and semiconductor lasers and, furthermore, with a few laser related topics. The different subjects are connected to each other by the central principle of the laser, namely, that it is a self-oscillating system. Special emphasis is put on a uniform treatment of gas and solid-state lasers, on the one hand, and semiconductor lasers, on the other hand. The discussions and the treatment of equations are presented in a way that a reader can immediately follow. The book addresses undergraduate and graduate students of science and engineering. Not only should it enable instructors to prepare their lectures, but it can be helpful to students for preparing for an examination.

Proceeding on the scientific meeting and presentation on basic research of nuclear science and technology (book I): physics, reactors

International Nuclear Information System (INIS)

Syarip; Prayitno; Samin; Agus Taftazani; Sudjatmoko; Pramudita Anggraita; Gede Sutresna W; Tjipto Sujitno; Slamet Santosa; Herry Poernomo; R Sukarsono; Prajitno

2014-06-01

Scientific Meeting and Presentation on Basic Research in Nuclear Science and Technology is an annual activity held by Centre for Accelerator Science and Technology, National Nuclear Energy Agency, in Yogyakarta, for monitoring research activities achieved by the Agency. The papers presented in the meeting were collected into proceedings which were divided into two groups that are physics and nuclear reactors. The proceedings consists of three articles from keynote speakers and 25 articles from BATAN and others participants.(PPIKSN)

Daily rhythms of the sleep-wake cycle

Directory of Open Access Journals (Sweden)

Waterhouse Jim

2012-03-01

Full Text Available Abstract The amount and timing of sleep and sleep architecture (sleep stages are determined by several factors, important among which are the environment, circadian rhythms and time awake. Separating the roles played by these factors requires specific protocols, including the constant routine and altered sleep-wake schedules. Results from such protocols have led to the discovery of the factors that determine the amounts and distribution of slow wave and rapid eye movement sleep as well as to the development of models to determine the amount and timing of sleep. One successful model postulates two processes. The first is process S, which is due to sleep pressure (and increases with time awake and is attributed to a 'sleep homeostat'. Process S reverses during slow wave sleep (when it is called process S'. The second is process C, which shows a daily rhythm that is parallel to the rhythm of core temperature. Processes S and C combine approximately additively to determine the times of sleep onset and waking. The model has proved useful in describing normal sleep in adults. Current work aims to identify the detailed nature of processes S and C. The model can also be applied to circumstances when the sleep-wake cycle is different from the norm in some way. These circumstances include: those who are poor sleepers or short sleepers; the role an individual's chronotype (a measure of how the timing of the individual's preferred sleep-wake cycle compares with the average for a population; and changes in the sleep-wake cycle with age, particularly in adolescence and aging, since individuals tend to prefer to go to sleep later during adolescence and earlier in old age. In all circumstances, the evidence that sleep times and architecture are altered and the possible causes of these changes (including altered S, S' and C processes are examined.

Surface wake in the random-phase approximation

International Nuclear Information System (INIS)

Garcia de Abajo, F.J.; Echenique, P.M.

1993-01-01

The scalar-electric-potential distribution set up by an ion traveling in the vicinity of a plane solid-vacuum interface, that is, the surface-wake potential, is investigated with the specular-reflection model to describe the response of the surface and with the random-phase approximation for the dielectric function of the bulk material. This permits us to address the study of the low-velocity surface wake: the static potential is found to have a dip at the position of the ion; that dip is shifted towards the direction opposite to the velocity vector for velocities smaller than the threshold of creation of plasmons (∼1.3v F ). Extensive numerical calculations are presented for an ion both inside and outside aluminum. Comparison to the results obtained with the plasmon-pole dielectric function indicates excellent agreement for velocities larger than ∼1.3v F . On the other side, the possibility of surface-wake riding is suggested, by analogy with bulk-wake riding postulated in the past. In it, the electron would be bound in the first trough of the surface-wake potential set up when the ion describes a grazing trajectory. The main feature introduced by the surface with respect to the bulk consists of allowing the use of ions of higher charge, reducing in this way the relative importance of the electron self-energy, and in addition, giving rise to larger binding energies. When the ion beam is directed along a special direction of an oriented crystal surface, the mechanism of resonant coherent excitation could provide a way for experimentally detecting this phenomenon through the emission of the bound electron with well-defined energy and around a preferential direction

Nonlinear Eddy Viscosity Models applied to Wind Turbine Wakes

DEFF Research Database (Denmark)

Laan, van der, Paul Maarten; Sørensen, Niels N.; Réthoré, Pierre-Elouan

2013-01-01

The linear k−ε eddy viscosity model and modified versions of two existing nonlinear eddy viscosity models are applied to single wind turbine wake simulations using a Reynolds Averaged Navier-Stokes code. Results are compared with field wake measurements. The nonlinear models give better results...

Cleft Palate-Craniofacial Journal 50th anniversary editorial board commentary: anatomy, basic sciences, and genetics--then and now.

Science.gov (United States)

Mooney, Mark P; Cooper, Gregory M; Marazita, Mary L

2014-05-01

To celebrate the 50th year of the Cleft Palate-Craniofacial Journal we look back to where we started in 1964 and where we are now, and we speculate about directions for the future in a "Then and Now" editorial series. This editorial examines changing trends and perspectives in anatomical, basic science, and genetic studies published in this 50-year interval. In volume 1 there were 45 total papers, seven (16%) of which were peer-reviewed basic science and genetic articles published: four in anatomy, three in craniofacial biology, and none in genetics. In contrast, in volume 50, of 113 articles there were 47 (42%) peer-reviewed basic science and genetic articles published: 30 in anatomy, five in craniofacial biology, and 12 in genetics. Topical analysis of published manuscripts then and now reveal that similar topics in anatomy and craniofacial biology are still being researched today (e.g., phenotypic variability, optimal timing of surgery, presurgical orthopedics, bone grafting); whereas, most of the more recent papers use advanced technology to address old questions. In contrast, genetic publications have clearly increased in frequency during the last 50 years, which parallels advances in the field during this time. However, all of us have noticed that the more "cutting-edge" papers in these areas are not being submitted for publication to the journal, but instead to discipline-specific journals. Concerted efforts are therefore indicated to attract and publish these cutting-edge papers in order to keep the Cleft Palate-Craniofacial Journal in the forefront of orofacial cleft and craniofacial anomaly research and to provide a valuable service to American Cleft Palate-Craniofacial Association members.

Developing a competency-based medical education curriculum for the core basic medical sciences in an African Medical School.

Science.gov (United States)

Olopade, Funmilayo Eniola; Adaramoye, Oluwatosin Adekunle; Raji, Yinusa; Fasola, Abiodun Olubayo; Olapade-Olaopa, Emiola Oluwabunmi

2016-01-01

The College of Medicine of the University of Ibadan recently revised its MBBS and BDS curricula to a competency-based medical education method of instruction. This paper reports the process of revising the methods of instruction and assessment in the core basic medical sciences directed at producing medical and dental graduates with a sound knowledge of the subjects sufficient for medical and dental practice and for future postgraduate efforts in the field or related disciplines. The health needs of the community and views of stakeholders in the Ibadan medical and dental schools were determined, and the "old" curriculum was reviewed. This process was directed at identifying the strengths and weaknesses of the old curricula and the newer competences required for modern-day medical/dental practice. The admission criteria and processes and the learning methods of the students were also studied. At the end of the review, an integrated, system-based, community-oriented, person-centered, and competency-driven curriculum was produced and approved for implementation. Four sets of students have been admitted into the curriculum. There have been challenges to the implementation process, but these have been overcome by continuous faculty development and reorientation programs for the nonteaching staff and students. Two sets of students have crossed over to the clinical school, and the consensus among the clinical teachers is that their knowledge and application of the basic medical sciences are satisfactory. The Ibadan medical and dental schools are implementing their competency-based medical education curricula successfully. The modifications to the teaching and assessment of the core basic medical science subjects have resulted in improved learning and performance at the final examinations.

The sleep-wake cycle and Alzheimer's disease: what do we know?

Science.gov (United States)

Lim, Miranda M; Gerstner, Jason R; Holtzman, David M

2014-01-01

Sleep-wake disturbances are a highly prevalent and often disabling feature of Alzheimer's disease (AD). A cardinal feature of AD includes the formation of amyloid plaques, associated with the extracellular accumulation of the amyloid-β (Aβ) peptide. Evidence from animal and human studies suggests that Aβ pathology may disrupt the sleep-wake cycle, in that as Aβ accumulates, more sleep-wake fragmentation develops. Furthermore, recent research in animal and human studies suggests that the sleep-wake cycle itself may influence Alzheimer's disease onset and progression. Chronic sleep deprivation increases amyloid plaque deposition, and sleep extension results in fewer plaques in experimental models. In this review geared towards the practicing clinician, we discuss possible mechanisms underlying the reciprocal relationship between the sleep-wake cycle and AD pathology and behavior, and present current approaches to therapy for sleep disorders in AD.

Terry Turbopump Expanded Operating Band Full-Scale Component and Basic Science Detailed Test Plan - Final.

Energy Technology Data Exchange (ETDEWEB)

Osborn, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Solom, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-02-01

This document details the milestone approach to define the true operating limitations (margins) of the Terry turbopump systems used in the nuclear industry for Milestone 3 (full-scale component experiments) and Milestone 4 (Terry turbopump basic science experiments) efforts. The overall multinational-sponsored program creates the technical basis to: (1) reduce and defer additional utility costs, (2) simplify plant operations, and (3) provide a better understanding of the true margin which could reduce overall risk of operations.

Why Does Rem Sleep Occur? A Wake-Up Hypothesis 1

OpenAIRE

Klemm, W. R.

2011-01-01

Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses rapid eye movement (REM) to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, (1) when first going to sleep, the brain plunges into ...

Improvement of a near wake model for trailing vorticity

International Nuclear Information System (INIS)

Pirrung, G R; Hansen, M H; Madsen, H A

2014-01-01

A near wake model, originally proposed by Beddoes, is further developed. The purpose of the model is to account for the radially dependent time constants of the fast aerodynamic response and to provide a tip loss correction. It is based on lifting line theory and models the downwash due to roughly the first 90 degrees of rotation. This restriction of the model to the near wake allows for using a computationally efficient indicial function algorithm. The aim of this study is to improve the accuracy of the downwash close to the root and tip of the blade and to decrease the sensitivity of the model to temporal discretization, both regarding numerical stability and quality of the results. The modified near wake model is coupled to an aerodynamics model, which consists of a blade element momentum model with dynamic inflow for the far wake and a 2D shed vorticity model that simulates the unsteady buildup of both lift and circulation in the attached flow region. The near wake model is validated against the test case of a finite wing with constant elliptical bound circulation. An unsteady simulation of the NREL 5 MW rotor shows the functionality of the coupled model

Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

Energy Technology Data Exchange (ETDEWEB)

Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Visser, T.J. [Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Krenning, E.P. [Dept. of Nuclear Medicine, Erasmus Medical Centre Rotterdam (Netherlands); Dept. of Internal Medicine, Erasmus Medical Centre Rotterdam (Netherlands)

2001-09-01

In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

Somatostatin receptor-mediated imaging and therapy: basic science, current knowledge, limitations and future perspectives

International Nuclear Information System (INIS)

Breeman, W.A.P.; Jong, M. de; Kwekkeboom, D.J.; Valkema, R.; Bakker, W.H.; Kooij, P.P.M.; Visser, T.J.; Krenning, E.P.

2001-01-01

In vivo somatostatin receptor-mediated scintigraphy has proven to be a valuable method for the visualisation of neuroendocrine tumours and their metastases. A new application is the use of radiolabelled analogues for somatostatin receptor-mediated therapy. This paper presents a review on the basic science, historical background and current knowledge of somatostatin receptor subtypes and their expression in neuroendocrine tumours. New somatostatin analogues, new chelators, ''new'' radionuclides and combinations thereof are also discussed. Due attention is given to limitations and future perspectives of somatostatin receptor-mediated imaging and therapy. (orig.)

Light detection and ranging measurements of wake dynamics. Part II: two-dimensional scanning

DEFF Research Database (Denmark)

Trujillo, Juan-José; Bingöl, Ferhat; Larsen, Gunner Chr.

2011-01-01

the instantaneous transversal wake position which is quantitatively compared with the prediction of the Dynamic Wake Meandering model. The results, shown for two 10-min time series, suggest that the conjecture of the wake behaving as a passive tracer is a fair approximation; this corroborates and expands...... the results of one-dimensional measurements already presented in the first part of this paper. Consequently, it is now possible to separate the deterministic and turbulent parts of the wake wind field, thus enabling capturing the wake in the meandering frame of reference. The results correspond, qualitatively...

Simulation of Wake Vortex Radiometric Detection via Jet Exhaust Proxy

Science.gov (United States)

Daniels, Taumi S.

2015-01-01

This paper describes an analysis of the potential of an airborne hyperspectral imaging IR instrument to infer wake vortices via turbine jet exhaust as a proxy. The goal was to determine the requirements for an imaging spectrometer or radiometer to effectively detect the exhaust plume, and by inference, the location of the wake vortices. The effort examines the gas spectroscopy of the various major constituents of turbine jet exhaust and their contributions to the modeled detectable radiance. Initially, a theoretical analysis of wake vortex proxy detection by thermal radiation was realized in a series of simulations. The first stage used the SLAB plume model to simulate turbine jet exhaust plume characteristics, including exhaust gas transport dynamics and concentrations. The second stage used these plume characteristics as input to the Line By Line Radiative Transfer Model (LBLRTM) to simulate responses from both an imaging IR hyperspectral spectrometer or radiometer. These numerical simulations generated thermal imagery that was compared with previously reported wake vortex temperature data. This research is a continuation of an effort to specify the requirements for an imaging IR spectrometer or radiometer to make wake vortex measurements. Results of the two-stage simulation will be reported, including instrument specifications for wake vortex thermal detection. These results will be compared with previously reported results for IR imaging spectrometer performance.

Neurological impairments and sleep-wake behaviour among the mentally retarded.

Science.gov (United States)

Lindblom, N; Heiskala, H; Kaski, M; Leinonen, L; Nevanlinna, A; Iivanainen, M; Laakso, M L

2001-12-01

The objective of the present study was to evaluate the relationship between the sleep-wake behaviour and neurological impairments among mentally retarded people. The sleep-wake behaviour of 293 mentally retarded subjects living in a rehabilitation center was studied by a standardized observation protocol carried out by trained staff members. The protocol consisted of brief check-ups of the subjects' sleep-wake status at 20-min intervals for five randomly chosen 24-h periods during 4 months. From the raw data five sleep-wake behaviour variables were formed. The data concerning the subject characteristics (age, body mass index (BMI), gender, degree of mental retardation, presence of locomotor disability, that of epilepsy, blindness or deafness and the usage of psychotropic medications) were collected from the medical records. Two main findings emerged: (1) severe locomotor disability, blindness and active epilepsy were found to be independent predictors of increased daytime sleep and increased number of wake-sleep transitions and (2) the subjects with a combination of two or all three of these impairments had a significantly more fragmented and abnormally distributed sleep than those with none or milder forms of these impairments. Age, BMI, degree of mental retardation and the studied medications played a minor role in the sleep disturbances of the study population. Finally, deafness was not found to be associated with any of the measured sleep-wake variables.

Sensitivity Analysis to Control the Far-Wake Unsteadiness Behind Turbines

Directory of Open Access Journals (Sweden)

Esteban Ferrer

2017-10-01

Full Text Available We explore the stability of wakes arising from 2D flow actuators based on linear momentum actuator disc theory. We use stability and sensitivity analysis (using adjoints to show that the wake stability is controlled by the Reynolds number and the thrust force (or flow resistance applied through the turbine. First, we report that decreasing the thrust force has a comparable stabilising effect to a decrease in Reynolds numbers (based on the turbine diameter. Second, a discrete sensitivity analysis identifies two regions for suitable placement of flow control forcing, one close to the turbines and one far downstream. Third, we show that adding a localised control force, in the regions identified by the sensitivity analysis, stabilises the wake. Particularly, locating the control forcing close to the turbines results in an enhanced stabilisation such that the wake remains steady for significantly higher Reynolds numbers or turbine thrusts. The analysis of the controlled flow fields confirms that modifying the velocity gradient close to the turbine is more efficient to stabilise the wake than controlling the wake far downstream. The analysis is performed for the first flow bifurcation (at low Reynolds numbers which serves as a foundation of the stabilization technique but the control strategy is tested at higher Reynolds numbers in the final section of the paper, showing enhanced stability for a turbulent flow case.

Four-dimensional characterization of inflow to and wakes from a multi-MW turbine: overview of the Turbine Wake and Inflow Characterization Study (TWICS2011)

Science.gov (United States)

Lundquist, J. K.; Banta, R. M.; Pichugina, Y.; Brewer, A.; Alvarez, R. J.; Sandberg, S. P.; Kelley, N. D.; Aitken, M.; Clifton, A.; Mirocha, J. D.

2011-12-01

To support substantial deployment of renewably-generated electricity from the wind, critical information about the variability of wind turbine wakes in the real atmosphere from multi-MW turbines is required. The assessment of the velocity deficit and turbulence associated with industrial-scale turbines is a major issue for wind farm design, particularly with respect to the optimization of the spacing between turbines. The significant velocity deficit and turbulence generated by upstream turbines can reduce the power production and produce harmful vibrations in downstream turbines, which can lead to excess maintenance costs. The complexity of wake effects depends on many factors arising from both hardware (turbine size, rotor speed, and blade geometry, etc.) and from meteorological considerations such as wind velocity, gradients of wind across the turbine rotor disk, atmospheric stability, and atmospheric turbulence. To characterize the relationships between the meteorological inflow and turbine wakes, a collaborative field campaign was designed and carried out at the Department of Energy's National Wind Technology Center (NREL/NWTC) in south Boulder, Colorado, in spring 2011. This site often experiences channeled flow with a consistent wind direction, enabling robust statistics of wake velocity deficits and turbulence enhancements. Using both in situ and remote sensing instrumentation, measurements upwind and downwind of multi-megawatt wind turbine in complex terrain quantified the variability of wind turbine inflow and wakes from an industrial-scale turbine. The turbine of interest has a rated power of 2.3 MW, a rotor diameter of 100m, and a hub height of 80m. In addition to several meteorological towers, one extending to hub height (80m) and another extending above the top of the rotor disk (135m), a Triton mini-sodar and a Windcube lidar characterized the inflow to the turbine and the variability across the site. The centerpiece instrument of the TWICS campaign

Improvement of a near wake model for trailing vorticity

DEFF Research Database (Denmark)

Pirrung, Georg; Hansen, Morten Hartvig; Aagaard Madsen, Helge

2014-01-01

A near wake model, originally proposed by Beddoes, is further developed. The purpose of the model is to account for the radially dependent time constants of the fast aerodynamic response and to provide a tip loss correction. It is based on lifting line theory and models the downwash due to roughly...... the first 90 degrees of rotation. This restriction of the model to the near wake allows for using a computationally efficient indicial function algorithm. The aim of this study is to improve the accuracy of the downwash close to the root and tip of the blade and to decrease the sensitivity of the model...... to temporal discretization, both regarding numerical stability and quality of the results. The modified near wake model is coupled to an aerodynamics model, which consists of a blade element momentum model with dynamic inflow for the far wake and a 2D shed vorticity model that simulates the unsteady buildup...

Wind Farm Wake: The Horns Rev Photo Case

Directory of Open Access Journals (Sweden)

Pierre-Elouan Réthoré

2013-02-01

Full Text Available The aim of the paper is to examine the nowadays well-known wind farm wake photographs taken on 12 February 2008 at the offshore Horns Rev 1 wind farm. The meteorological conditions are described from observations from several satellite sensors quantifying clouds, surface wind vectors and sea surface temperature as well as ground-based information at and near the wind farm, including Supervisory Control and Data Acquisition (SCADA data. The SCADA data reveal that the case of fog formation occurred 12 February 2008 on the 10:10 UTC. The fog formation is due to very special atmospheric conditions where a layer of cold humid air above a warmer sea surface re-condensates to fog in the wake of the turbines. The process is fed by warm humid air up-drafted from below in the counter-rotating swirl generated by the clock-wise rotating rotors. The condensation appears to take place primarily in the wake regions with relatively high axial velocities and high turbulent kinetic energy. The wind speed is near cut-in and most turbines produce very little power. The rotational pattern of spiraling bands produces the large-scale structure of the wake fog.

Experimental investigation of an actively controlled three-dimensional turret wake

Science.gov (United States)

Shea, Patrick R.

Hemispherical turrets are bluff bodies commonly used to house optical systems on airborne platforms. These bluff bodies develop complex, three-dimensional flow fields that introduce high mean and fluctuating loads to the turret as well as the airframe support structure which reduce the performance of both the optical systems and the aircraft. An experimental investigation of the wake of a three-dimensional, non-conformal turret was performed in a low-speed wind tunnel at Syracuse University to develop a better understanding of the fundamental flow physics associated with the turret wake. The flow field was studied at a diameter based Reynolds number of 550,000 using stereoscopic particle image velocimetry and dynamic pressure measurements both with and without active flow control. Pressure measurements were simultaneously sampled with the PIV measurements and taken on the surrounding boundary layer plate and at several locations on the turret geometry. Active flow control of the turret wake was performed around the leading edge of the turret aperture using dynamic suction in steady open-loop, unsteady open-loop, and simple closed-loop configurations. Analysis of the uncontrolled wake provided insight into the complex three-dimensional wake when evaluated spatially using PIV measurements and temporally using spectral analysis of the pressure measurements. Steady open-loop suction was found to significantly alter the spatial and temporal nature of the turret wake despite the control being applied locally to the aperture region of the turret. Unsteady open-loop and simple closed-loop control were found to provide similar levels of control to the steady open-loop forcing with a 45% reduction in the control input as calculated using the jet momentum coefficient. The data set collected provides unique information regarding the development of the baseline three-dimensional wake and the wake with three different active flow control configurations. These data can be used to

Documentation on the interlinked sponsorship programme of the BMFT for basic research in the natural sciences

International Nuclear Information System (INIS)

1993-02-01

The reports from the individual research teams working at various places in Germany show their particular achievements on the one hand, and at the same time illustrate the effectiveness of the interlinked sponsorship concept adopted by the Federal Ministry of Science and Technology (BMFT). There is an annex giving statistical data on the scope and organisation of state sponsorship of basic research bound to large-scale research equipment. (DG) [de

Mast Wake Reduction by Shaping

National Research Council Canada - National Science Library

Beauchamp, Charles H

2005-01-01

The present invention relates to various mast shapes, in which the mast shapes minimize the production of visible, electro-optic, infrared and radar cross section wake signatures produced by water surface piercing masts...

Wake interaction and power production of variable height model wind farms

International Nuclear Information System (INIS)

Vested, M H; Sørensen, J N; Hamilton, N; Cal, R B

2014-01-01

Understanding wake dynamics is an ongoing research topic in wind energy, since wakes have considerable effects on the power production when wind turbines are placed in a wind farm. Wind tunnel experiments have been conducted to study the wake to wake interaction in a model wind farm in tandem with measurements of the extracted power. The aim is to investigate how alternating mast height influences the interaction of the wakes and the power production. Via the use of stereo-particle image velocimetry, the flow field was obtained in the first and last rows of the wind turbine array as a basis of comparison. It was found that downstream of the exit row wind turbine, the power was increased by 25% in the case of a staggered height configuration. This is partly due to the fact that the taller turbines reach into a flow area with a softened velocity gradient. Another aspect is that the wake downstream of a tall wind turbine to some extent passes above the standard height wind turbine. Overall the experiments show that the velocity field downstream of the exit row changes considerably when the mast height is alternating

Benchmarking of wind farm scale wake models in the EERA - DTOC project

DEFF Research Database (Denmark)

Réthoré, Pierre-Elouan; Hansen, Kurt Schaldemose; Barthelmie, R.J.

2013-01-01

-flow to combine wind farm (micro) and cluster (meso) scale wake models. For this purpose, a benchmark campaign is organized on the existing wind farm wake models available within the project, in order to identify which model would be the most appropriate for this coupling. A number of standardized wake cases......Designing offshore wind farms next to existing or planned wind farm clusters has recently become a common practice in the North Sea. These types of projects face unprecedented challenges in term of wind energy siting. The currently ongoing European project FP7 EERA - DTOC (Design Tool for Offshore...... wind farm Clusters) is aiming at providing a new type of model work-flow to address this issue. The wake modeling part of the EERA - DTOC project is to improve the fundamental understanding of wind turbine wakes and modeling. One of these challenges is to create a new kind of wake modeling work...

Comparison of two LES codes for wind turbine wake studies

DEFF Research Database (Denmark)

Chivaee, Hamid Sarlak; Pierella, F.; Mikkelsen, Robert Flemming

2014-01-01

of this paper is to investigate on two CFD solvers, the DTU's in-house code, EllipSys3D and the open-sourse toolbox, OpenFoam, for a set of actuator line based LES computations. Two types of simulations are performed: the wake behind a signle rotor and the wake behind a cluster of three inline rotors. Results...... are compared in terms of velocity deficit, turbulence kinetic energy and eddy viscosity. It is seen that both codes predict similar near-wake flow structures with the exception of OpenFoam's simulations without the subgrid-scale model. The differences begin to increase with increasing the distance from...... of the wake structures and more homogenuous flow structures. It is finally observed that OpenFoam computations are more sensitive to the SGS models....

The chain reaction: a golden jubilee commemorative volume on research in basic sciences at DAE Institutions. V. 1

International Nuclear Information System (INIS)

2005-01-01

This book has been chosen to metaphorically reflect how research in basic sciences in various institutions of the Department of Atomic Energy (DAE) has evolved over the years, closely mimicking what goes on in a nuclear chain reactor. Since, for harnessing atomic energy for peaceful uses, nuclear physics and atomic physics are the two core activities, work was undertaken in these areas during initial days at the Tata Institute of Fundamental Research. These activities then promoted the growth of major programmes in a number of areas, such as, reactor physics, accelerator physics, condensed matter physics and materials science, theoretical physics and mathematical physics, astronomy and astrophysics, laser and plasma physics, radiation chemistry, photochemistry, chemical dynamics, nuclear chemistry, radiation biology and health sciences, molecular and cellular biology, structural biology and biophysics, agriculture and food sciences etc. In turn, all these programmes have been fostering the growth in several other domains of science, engineering and technology

Multisite accelerometry for sleep and wake classification in children.

Science.gov (United States)

Lamprecht, Marnie L; Bradley, Andrew P; Tran, Tommy; Boynton, Alison; Terrill, Philip I

2015-01-01

Actigraphy is a useful alternative to the gold standard polysomnogram for non-invasively measuring sleep and wakefulness. However, it is unable to accurately assess sleep fragmentation due to its inability to differentiate restless sleep from wakefulness and quiet wake from sleep. This presents significant limitations in the assessment of sleep-related breathing disorders where sleep fragmentation is a common symptom. We propose that this limitation may be caused by hardware constraints and movement representation techniques. Our objective was to determine if multisite tri-axial accelerometry improves sleep and wake classification. Twenty-four patients aged 6-15 years (median: 8 years, 16 male) underwent a diagnostic polysomnogram while simultaneously recording motion from the left wrist and index fingertip, upper thorax and left ankle and great toe using a custom accelerometry system. Movement was quantified using several features and two feature selection techniques were employed to select optimal features for restricted feature set sizes. A heuristic was also applied to identify movements during restless sleep. The sleep and wake classification performance was then assessed and validated against the manually scored polysomnogram using discriminant analysis. Tri-axial accelerometry measured at the wrist significantly improved the wake detection when compared to uni-axial accelerometry (specificity at 85% sensitivity: 71.3(14.2)% versus 55.2(24.7)%, p < 0.01). Multisite accelerometry significantly improved the performance when compared to the single wrist placement (specificity at 85% sensitivity: 82.1(12.5)% versus 71.3(14.2)%, p < 0.05). Our results indicate that multisite accelerometry offers a significant performance benefit which could be further improved by analysing movement in raw multisite accelerometry data.

Sleep-Wake Patterns and Sleep Disturbance among Hong Kong Chinese Adolescents

OpenAIRE

Chung, Ka-Fai; Cheung, Miao-Miao

2008-01-01

STUDY OBJECTIVES: To determine sleep-wake patterns and evaluate sleep disturbance in Hong Kong adolescents; to identify factors that are associated with sleep disturbance; and to examine the relationship of sleep-wake variables and academic performance. DESIGN AND SETTING: A school-based cross-sectional survey. PARTICIPANTS: Sample included 1629 adolescents aged 12 to 19 years. MEASUREMENTS AND RESULTS: Self-report questionnaires, including sleep-wake habit questionnaire,...

Auditory Verbal Experience and Agency in Waking, Sleep Onset, REM, and Non-REM Sleep.

Science.gov (United States)

Speth, Jana; Harley, Trevor A; Speth, Clemens

2017-04-01

We present one of the first quantitative studies on auditory verbal experiences ("hearing voices") and auditory verbal agency (inner speech, and specifically "talking to (imaginary) voices or characters") in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants' implicit knowledge of auditory verbal experiences (VE) and auditory verbal agencies (VA), displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement (REM) sleep, non-REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap sleep-wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. Copyright © 2016 Cognitive Science Society, Inc.

Pharmacology education in North American dental schools: the basic science survey series.

Science.gov (United States)

Gautam, Medha; Shaw, David H; Pate, Ted D; Lambert, H Wayne

2013-08-01

As part of the Basic Science Survey Series (BSSS) for Dentistry, members of the American Dental Education Association (ADEA) Physiology, Pharmacology, and Therapeutics Section surveyed course directors of basic pharmacology courses in North American dental schools. The survey was designed to assess, among other things, faculty affiliation and experience of course directors, teaching methods, general course content and emphasis, extent of interdisciplinary (shared) instruction, and impact of recent curricular changes. Responses were received from forty-nine of sixty-seven (73.1 percent) U.S. and Canadian dental schools. The findings suggest the following: 1) substantial variation exists in instructional hours, faculty affiliation, placement within curriculum, class size, and interdisciplinary nature of pharmacology courses; 2) pharmacology course content emphasis is similar among schools; 3) the number of contact hours in pharmacology has remained stable over the past three decades; 4) recent curricular changes were often directed towards enhancing the integrative and clinically relevant aspects of pharmacology instruction; and 5) a trend toward innovative content delivery, such as use of computer-assisted instruction applications, is evident. Data, derived from this study, may be useful to pharmacology course directors, curriculum committees, and other dental educators with an interest in integrative and interprofessional education.

Comparison of the far wake behind dual rotor and dual disk configurations

DEFF Research Database (Denmark)

Okulov, Valery; Mikkelsen, Robert Flemming; Naumov, I. V.

2016-01-01

wake features for two rotors subjected to different operating and spatial conditions. As a part of this, a comparison with the wake development behind two disks replacing the rotor models was performed to determine the difference between the two wake systems.LDA and Stereo PIV experiments were carried...

Wake of inertial waves of a horizontal cylinder in horizontal translation

Science.gov (United States)

Machicoane, Nathanaël; Labarre, Vincent; Voisin, Bruno; Moisy, Frédéric; Cortet, Pierre-Philippe

2018-03-01

We analyze theoretically and experimentally the wake behind a horizontal cylinder of diameter d horizontally translated at constant velocity U in a fluid rotating about the vertical axis at a rate Ω . Using particle image velocimetry measurements in the rotating frame, we show that the wake is stabilized by rotation for Reynolds number Re =U d /ν much larger than in a nonrotating fluid. Over the explored range of parameters, the limit of stability is Re ≃(275 ±25 )/Ro , with Ro =U /2 Ω d the Rossby number, indicating that the stabilizing process is governed by the Ekman pumping in the boundary layer. At low Rossby number, the wake takes the form of a stationary pattern of inertial waves, similar to the wake of surface gravity waves behind a ship. We compare this steady wake pattern to a model, originally developed by Johnson [E. R. Johnson, J. Fluid Mech. 120, 359 (1982), 10.1017/S0022112082002808], assuming a free-slip boundary condition and a weak streamwise perturbation. Our measurements show quantitative agreement with this model for Ro ≲0.3 . At larger Rossby number, the phase pattern of the wake is close to the prediction for an infinitely small line object. However, the wake amplitude and phase origin are not correctly described by the weak-streamwise-perturbation model, calling for an alternative model for the boundary condition at moderate rotation rate.

Analyzing complex wake-terrain interactions and its implications on wind-farm performance.

Science.gov (United States)

Tabib, Mandar; Rasheed, Adil; Fuchs, Franz

2016-09-01

Rotating wind turbine blades generate complex wakes involving vortices (helical tip-vortex, root-vortex etc.).These wakes are regions of high velocity deficits and high turbulence intensities and they tend to degrade the performance of down-stream turbines. Hence, a conservative inter-turbine distance of up-to 10 times turbine diameter (10D) is sometimes used in wind-farm layout (particularly in cases of flat terrain). This ensures that wake-effects will not reduce the overall wind-farm performance, but this leads to larger land footprint for establishing a wind-farm. In-case of complex-terrain, within a short distance (say 10D) itself, the nearby terrain can rise in altitude and be high enough to influence the wake dynamics. This wake-terrain interaction can happen either (a) indirectly, through an interaction of wake (both near tip vortex and far wake large-scale vortex) with terrain induced turbulence (especially, smaller eddies generated by small ridges within the terrain) or (b) directly, by obstructing the wake-region partially or fully in its flow-path. Hence, enhanced understanding of wake- development due to wake-terrain interaction will help in wind farm design. To this end the current study involves: (1) understanding the numerics for successful simulation of vortices, (2) understanding fundamental vortex-terrain interaction mechanism through studies devoted to interaction of a single vortex with different terrains, (3) relating influence of vortex-terrain interactions to performance of a wind-farm by studying a multi-turbine wind-farm layout under different terrains. The results on interaction of terrain and vortex has shown a much faster decay of vortex for complex terrain compared to a flatter-terrain. The potential reasons identified explaining the observation are (a) formation of secondary vortices in flow and its interaction with the primary vortex and (b) enhanced vorticity diffusion due to increased terrain-induced turbulence. The implications of

Peer review, basic research, and engineering: Defining a role for QA professionals in basic research environments

Energy Technology Data Exchange (ETDEWEB)

Bodnarczuk, M.

1989-02-01

Within the context of doing basic research, this paper seeks to answer four major questions: (1) What is the authority structure of science. (2) What is peer review. (3) Where is the interface between basic physics research and standard engineering. and (4) Given the conclusions to the first three questions, what is the role of the QA professional in a basic research environment like Fermilab. 23 refs.

Wake-field studies on photonic band gap accelerator cavities

International Nuclear Information System (INIS)

Li, D.; Kroll, N.; Stanford Linear Accelerator Center, M/S 26, P.O. Box 4349, Stanford, California; Smith, D.R.; Schultz, S.

1997-01-01

We have studied the wake-field of several metal Photonic Band Gap (PBG) cavities which consist of either a square or a hexagonal array of metal cylinders, bounded on top and bottom by conducting or superconducting sheets, surrounded by placing microwave absorber at the periphery or by replacing outer rows of metal cylinders with lossy dielectric ones, or by metallic walls. A removed cylinder from the center of the array constitutes a site defect where a localized electromagnetic mode can occur. While both monopole and dipole wake-fields have been studied, we confine our attention here mainly to the dipole case. The dipole wake-field is produced by modes in the propagation bands which tend to fill the entire cavity more or less uniformly and are thus easy to damp selectively. MAFIA time domain simulation of the transverse wake-field has been compared with that of a cylindrical pill-box comparison cavity. Even without damping the wake-field of the metal PBG cavity is substantially smaller than that of the pill-box cavity and may be further reduced by increasing the size of the lattice. By introducing lossy material at the periphery we have been able to produce Q factors for the dipole modes in the 40 to 120 range without significantly degrading the accelerating mode. copyright 1997 American Institute of Physics

Basic Research Needs for Advanced Nuclear Systems. Report of the Basic Energy Sciences Workshop on Basic Research Needs for Advanced Nuclear Energy Systems, July 31-August 3, 2006

Energy Technology Data Exchange (ETDEWEB)

Roberto, J.; Diaz de la Rubia, T.; Gibala, R.; Zinkle, S.; Miller, J.R.; Pimblott, S.; Burns, C.; Raymond, K.; Grimes, R.; Pasamehmetoglu, K.; Clark, S.; Ewing, R.; Wagner, A.; Yip, S.; Buchanan, M.; Crabtree, G.; Hemminger, J.; Poate, J.; Miller, J.C.; Edelstein, N.; Fitzsimmons, T.; Gruzalski, G.; Michaels, G.; Morss, L.; Peters, M.; Talamini, K.

2006-10-01

The global utilization of nuclear energy has come a long way from its humble beginnings in the first sustained nuclear reaction at the University of Chicago in 1942. Today, there are over 440 nuclear reactors in 31 countries producing approximately 16% of the electrical energy used worldwide. In the United States, 104 nuclear reactors currently provide 19% of electrical energy used nationally. The International Atomic Energy Agency projects significant growth in the utilization of nuclear power over the next several decades due to increasing demand for energy and environmental concerns related to emissions from fossil plants. There are 28 new nuclear plants currently under construction including 10 in China, 8 in India, and 4 in Russia. In the United States, there have been notifications to the Nuclear Regulatory Commission of intentions to apply for combined construction and operating licenses for 27 new units over the next decade. The projected growth in nuclear power has focused increasing attention on issues related to the permanent disposal of nuclear waste, the proliferation of nuclear weapons technologies and materials, and the sustainability of a once-through nuclear fuel cycle. In addition, the effective utilization of nuclear power will require continued improvements in nuclear technology, particularly related to safety and efficiency. In all of these areas, the performance of materials and chemical processes under extreme conditions is a limiting factor. The related basic research challenges represent some of the most demanding tests of our fundamental understanding of materials science and chemistry, and they provide significant opportunities for advancing basic science with broad impacts for nuclear reactor materials, fuels, waste forms, and separations techniques. Of particular importance is the role that new nanoscale characterization and computational tools can play in addressing these challenges. These tools, which include DOE synchrotron X

Basic Research Needs for Advanced Nuclear Systems. Report of the Basic Energy Sciences Workshop on Basic Research Needs for Advanced Nuclear Energy Systems, July 31-August 3, 2006

International Nuclear Information System (INIS)

Roberto, J.; Diaz de la Rubia, T.; Gibala, R.; Zinkle, S.; Miller, J.R.; Pimblott, S.; Burns, C.; Raymond, K.; Grimes, R.; Pasamehmetoglu, K.; Clark, S.; Ewing, R.; Wagner, A.; Yip, S.; Buchanan, M.; Crabtree, G.; Hemminger, J.; Poate, J.; Miller, J.C.; Edelstein, N.; Fitzsimmons, T.; Gruzalski, G.; Michaels, G.; Morss, L.; Peters, M.; Talamini, K.

2006-01-01

The global utilization of nuclear energy has come a long way from its humble beginnings in the first sustained nuclear reaction at the University of Chicago in 1942. Today, there are over 440 nuclear reactors in 31 countries producing approximately 16% of the electrical energy used worldwide. In the United States, 104 nuclear reactors currently provide 19% of electrical energy used nationally. The International Atomic Energy Agency projects significant growth in the utilization of nuclear power over the next several decades due to increasing demand for energy and environmental concerns related to emissions from fossil plants. There are 28 new nuclear plants currently under construction including 10 in China, 8 in India, and 4 in Russia. In the United States, there have been notifications to the Nuclear Regulatory Commission of intentions to apply for combined construction and operating licenses for 27 new units over the next decade. The projected growth in nuclear power has focused increasing attention on issues related to the permanent disposal of nuclear waste, the proliferation of nuclear weapons technologies and materials, and the sustainability of a once-through nuclear fuel cycle. In addition, the effective utilization of nuclear power will require continued improvements in nuclear technology, particularly related to safety and efficiency. In all of these areas, the performance of materials and chemical processes under extreme conditions is a limiting factor. The related basic research challenges represent some of the most demanding tests of our fundamental understanding of materials science and chemistry, and they provide significant opportunities for advancing basic science with broad impacts for nuclear reactor materials, fuels, waste forms, and separations techniques. Of particular importance is the role that new nanoscale characterization and computational tools can play in addressing these challenges. These tools, which include DOE synchrotron X

Comparison of two LES codes for wind turbine wake studies

International Nuclear Information System (INIS)

Sarlak, H; Mikkelsen, R; Sørensen, J N; Pierella, F

2014-01-01

For the third time a blind test comparison in Norway 2013, was conducted comparing numerical simulations for the rotor C p and C t and wake profiles with the experimental results. As the only large eddy simulation study among participants, results of the Technical University of Denmark (DTU) using their in-house CFD solver, EllipSys3D, proved to be more reliable among the other models for capturing the wake profiles and the turbulence intensities downstream the turbine. It was therefore remarked in the workshop to investigate other LES codes to compare their performance with EllipSys3D. The aim of this paper is to investigate on two CFD solvers, the DTU's in-house code, EllipSys3D and the open-sourse toolbox, OpenFoam, for a set of actuator line based LES computations. Two types of simulations are performed: the wake behind a signle rotor and the wake behind a cluster of three inline rotors. Results are compared in terms of velocity deficit, turbulence kinetic energy and eddy viscosity. It is seen that both codes predict similar near-wake flow structures with the exception of OpenFoam's simulations without the subgrid-scale model. The differences begin to increase with increasing the distance from the upstream rotor. From the single rotor simulations, EllipSys3D is found to predict a slower wake recovery in the case of uniform laminar flow. From the 3-rotor computations, it is seen that the difference between the codes is smaller as the disturbance created by the downstream rotors causes break down of the wake structures and more homogenuous flow structures. It is finally observed that OpenFoam computations are more sensitive to the SGS models

Maximum wind power plant generation by reducing the wake effect

International Nuclear Information System (INIS)

De-Prada-Gil, Mikel; Alías, César Guillén; Gomis-Bellmunt, Oriol; Sumper, Andreas

2015-01-01

Highlights: • To analyze the benefit of applying a new control strategy to maximise energy yield. • To operate some wind turbines at non-optimum points for reducing wake effects. • Single, partial and multiple wakes for any wind direction are taken into account. • Thrust coefficient is computed according to Blade Element Momentum (BEM) theory. - Abstract: This paper analyses, from a steady state point of view, the potential benefit of a Wind Power Plant (WPP) control strategy whose main objective is to maximise its total energy yield over its lifetime by taking into consideration that the wake effect within the WPP varies depending on the operation of each wind turbine. Unlike the conventional approach in which each wind turbine operation is optimised individually to maximise its own energy capture, the proposed control strategy aims to optimise the whole system by operating some wind turbines at sub-optimum points, so that the wake effect within the WPP is reduced and therefore the total power generation is maximised. The methodology used to assess the performance of both control approaches is presented and applied to two particular study cases. It contains a comprehensive wake model considering single, partial and multiple wake effects among turbines. The study also takes into account the Blade Element Momentum (BEM) theory to accurately compute both power and thrust coefficient of each wind turbine. The results suggest a good potential of the proposed concept, since an increase in the annual energy captured by the WPP from 1.86% up to 6.24% may be achieved (depending on the wind rose at the WPP location) by operating some specific wind turbines slightly away from their optimum point and reducing thus the wake effect

Local Use-Dependent Sleep in Wakefulness Links Performance Errors to Learning.

Science.gov (United States)

Quercia, Angelica; Zappasodi, Filippo; Committeri, Giorgia; Ferrara, Michele

2018-01-01

Sleep and wakefulness are no longer to be considered as discrete states. During wakefulness brain regions can enter a sleep-like state (off-periods) in response to a prolonged period of activity (local use-dependent sleep). Similarly, during nonREM sleep the slow-wave activity, the hallmark of sleep plasticity, increases locally in brain regions previously involved in a learning task. Recent studies have demonstrated that behavioral performance may be impaired by off-periods in wake in task-related regions. However, the relation between off-periods in wake, related performance errors and learning is still untested in humans. Here, by employing high density electroencephalographic (hd-EEG) recordings, we investigated local use-dependent sleep in wake, asking participants to repeat continuously two intensive spatial navigation tasks. Critically, one task relied on previous map learning (Wayfinding) while the other did not (Control). Behaviorally awake participants, who were not sleep deprived, showed progressive increments of delta activity only during the learning-based spatial navigation task. As shown by source localization, delta activity was mainly localized in the left parietal and bilateral frontal cortices, all regions known to be engaged in spatial navigation tasks. Moreover, during the Wayfinding task, these increments of delta power were specifically associated with errors, whose probability of occurrence was significantly higher compared to the Control task. Unlike the Wayfinding task, during the Control task neither delta activity nor the number of errors increased progressively. Furthermore, during the Wayfinding task, both the number and the amplitude of individual delta waves, as indexes of neuronal silence in wake (off-periods), were significantly higher during errors than hits. Finally, a path analysis linked the use of the spatial navigation circuits undergone to learning plasticity to off periods in wake. In conclusion, local sleep regulation in

Doppler lidar investigation of wind turbine wake characteristics and atmospheric turbulence under different surface roughness.

Science.gov (United States)

Zhai, Xiaochun; Wu, Songhua; Liu, Bingyi

2017-06-12

Four field experiments based on Pulsed Coherent Doppler Lidar with different surface roughness have been carried out in 2013-2015 to study the turbulent wind field in the vicinity of operating wind turbine in the onshore and offshore wind parks. The turbulence characteristics in ambient atmosphere and wake area was analyzed using transverse structure function based on Plane Position Indicator scanning mode. An automatic wake processing procedure was developed to determine the wake velocity deficit by considering the effect of ambient velocity disturbance and wake meandering with the mean wind direction. It is found that the turbine wake obviously enhances the atmospheric turbulence mixing, and the difference in the correlation of turbulence parameters under different surface roughness is significant. The dependence of wake parameters including the wake velocity deficit and wake length on wind velocity and turbulence intensity are analyzed and compared with other studies, which validates the empirical model and simulation of a turbine wake for various atmosphere conditions.

Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness.

Science.gov (United States)

Miller, Nita Lewis; Tvaryanas, Anthony P; Shattuck, Lawrence G

2012-08-01

This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. TRAINEES: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment.

Exploration of problem-based learning combined with standardized patient in the teaching of basic science of ophthalmology

Directory of Open Access Journals (Sweden)

Jin Yan

2015-08-01

Full Text Available AIM:To investigate the effect of problem-based learning(PBLcombined with standardized patient(SPin the teaching of basic science of ophthalmology. METHODS: Sixty-four students of Optometry in grade 2012 were randomly divided into experimental group(n=32and control group(n=32. Traditional teaching method was implemented in control group while PBL combined with SP was applied in experimental group. At the end of term students were interviewed using self-administered questionnaire to obtain their evaluation for teaching effect. Measurement data were expressed as (-overx±s and analyzed by independent samples t test. Enumeration data were analyzed by χ2 test, and PRESULTS:The mean scores of theory test(83.22±3.75and experimental test(94.28±2.20in experimental group were significantly higher than theory test(70.72±3.95and experimental test(85.44±3.52in control group(all PPPCONCLUSION:Using PBL combined with SP teaching mode in basic science of ophthalmology can highly improve learning enthusiasm of students and cultivate self-learning ability of students, practice ability and ability of clinical analysis.

Investigation of Pre-Service Teachers' Opinions about Science in Terms of the Basic Elements of the Education Program

Science.gov (United States)

Sengul, Ozge Aydin

2016-01-01

The purpose of the current study is to investigate the pre-service teachers' opinions about science within the context of the basic elements of the education program, such as objectives, content, learning-teaching process and evaluation. The study was designed as a case study, one of the qualitative research methods. The participants of the study…

Investigating fundamental properties of wind turbine wake structure using particle image velocimetry

Energy Technology Data Exchange (ETDEWEB)

Whale, J. [Univ. of Edinburgh, Dept. of Mechanical Engineering, Edinburgh (United Kingdom)

1997-08-01

Low Reynolds number flow visualization tests are often used for showing the flow pattern changes associated with changes in lift-coefficients at a higher Reynolds number. In wind turbine studies, analysis of measured wake structures at small scale may reveal fundamental properties of the wake which will offer wake modellers a more complete understanding of rotor flows. Measurements are presented from experiments on a model wind turbine rig conducted in a water channel. The laser-optics technique of Particle Image Velocimetry (PIV) is used to make simultaneous multi-point measurements of the wake flow behind small-scale rotors. Analysis of the PIV data shows trends in velocity and vorticity structure in the wake. Study of the flow close to the rotor plane reveals information on stalled flow and blade performance. (au)

Simulation of Rotary-Wing Near-Wake Vortex Structures Using Navier-Stokes CFD Methods

Science.gov (United States)

Kenwright, David; Strawn, Roger; Ahmad, Jasim; Duque, Earl; Warmbrodt, William (Technical Monitor)

1997-01-01

This paper will use high-resolution Navier-Stokes computational fluid dynamics (CFD) simulations to model the near-wake vortex roll-up behind rotor blades. The locations and strengths of the trailing vortices will be determined from newly-developed visualization and analysis software tools applied to the CFD solutions. Computational results for rotor nearwake vortices will be used to study the near-wake vortex roll up for highly-twisted tiltrotor blades. These rotor blades typically have combinations of positive and negative spanwise loading and complex vortex wake interactions. Results of the computational studies will be compared to vortex-lattice wake models that are frequently used in rotorcraft comprehensive codes. Information from these comparisons will be used to improve the rotor wake models in the Tilt-Rotor Acoustic Code (TRAC) portion of NASA's Short Haul Civil Transport program (SHCT). Accurate modeling of the rotor wake is an important part of this program and crucial to the successful design of future civil tiltrotor aircraft. The rotor wake system plays an important role in blade-vortex interaction noise, a major problem for all rotorcraft including tiltrotors.