Inspiring students through an authentic polar science expedition: the RESEt Project

Science.gov (United States)

Cattadori, Matteo

2016-04-01

RESEt (Research and Education Svalbard Experience www.resetsvalbard.it) is an ongoing educational project focusing mainly on polar and climate system topics. It started in 2014 and will end in 2017 with the high school diploma of the 22 students (16 y. o.) making the participant class. This class attend a school (Liceo Filzi, Rovereto, Trento. Italy) with a primary focus on disciplines like philosophy and education, rather then STEM (Science, Technology, Engineering, and Mathematics). Nevertheless their science curricula include climate topics that are rather challenging to grasp and, at the same time, crucial for their scientific citizenship. Some questions arise: How to foster their interest in geosciences topics? How to engage them in authentic scientific knowledge? How to increase their interest in scientific university courses during their post-secondary career? RESEt project will attempt to answer these questions through the development of integrated activities distributed over the last three years of their high school cycle. The most important moment will be an educational scientific expedition at the Svalbard, an archipelago located in the Arctic. The expedition be entirely organized, planned, and directed by students. In Svalbard, students will visit the main scientific facilities devoted to climate studies including those of Italian CNR (National Research Council) and they will perform some environmental measurement using data-loggers. Students are even involved in the fundraising process to raise more than ten thousand Euros needed to for travel expenses. This work is aimed mainly at presenting some of the preliminary data collected during the RESEt project, including the fundraising aspects. The management of the RESEt project strongly relies on the experience and network gained by the abstract author during the participation to the Education and Public Outreach (EPO) program of International Polar Year (IPY) 2007-2009 as well as the support of Polar

Promoting Diversity Through Polar Interdisciplinary Coordinated Education (Polar ICE)

Science.gov (United States)

McDonnell, J. D.; Hotaling, L. A.; Garza, C.; Van Dyk, P. B.; Hunter-thomson, K. I.; Middendorf, J.; Daniel, A.; Matsumoto, G. I.; Schofield, O.

2017-12-01

Polar Interdisciplinary Coordinated Education (ICE) is an education and outreach program designed to provide public access to the Antarctic and Arctic regions through polar data and interactions with the scientists. The program provides multi-faceted science communication training for early career scientists that consist of a face-to face workshop and opportunities to apply these skills. The key components of the scientist training workshop include cultural competency training, deconstructing/decoding science for non-expert audiences, the art of telling science stories, and networking with members of the education and outreach community and reflecting on communication skills. Scientists partner with educators to provide professional development for K-12 educators and support for student research symposia. Polar ICE has initiated a Polar Literacy initiative that provides both a grounding in big ideas in polar science and science communication training designed to underscore the importance of the Polar Regions to the public while promoting interdisciplinary collaborations between scientists and educators. Our ultimate objective is to promote STEM identity through professional development of scientists and educators while developing career awareness of STEM pathways in Polar science.

Polar Voices: Relaying the Science and Story of Polar Climate Change through Podcast

Science.gov (United States)

Moloney, M.; Quinney, A.; Murray, M. S.

2016-12-01

The resurgence of audio programming with the advent of podcasting in the early 2000's spawned a new medium for communicating advances in science, research, and technology. To capitalize on this informal educational outlet, the Arctic Institute of North America (AINA) partnered with the International Arctic Research Center, the University of Alaska Fairbanks, and the UA Museum of the North to develop a podcast series called PoLAR Voices for the Polar Learning and Responding (PoLAR) Climate Change Education Partnership. Now entering its third season of production, PoLAR Voices has facilitated the communication of scientific knowledge regarding the impact of climate change on the Arctic and Antarctic from the perspectives of both scientific researchers and Arctic indigenous peoples. We present a holistic program detailing both data and research related to climate change in addition to personal stories from those people and communities most affected. An evaluation of the program has been conducted by the Goodman Research Group to assess the effectiveness of the program for relaying the whole story of climate change to the public. The results of this assessment will be used to further develop the program to effectively reach larger and more diverse audiences. The series is currently available on thepolarhub.org and iTunes, and we are exploring opportunities to air the program on radio to reach as many people as possible.

A home for science: The life and times of Tropical and Polar field stations.

Science.gov (United States)

Geissler, P Wenzel; Kelly, Ann H

2016-12-01

A 'halfway house' between the generic, purified space of the laboratory and the varied and particular spaces of the field, the field station is a controlled yet uncontained setting from which nature can be accessed and anchored. As living quarters for visiting scientists, field stations are also enmeshed in the routine and rhythms of everyday domestic life, and in longer cycles of habitation, wear, and repair. This introduction considers the empirical and conceptual significance of Polar and Tropical field stations as homes for scientific work and scientific lives. The field station's extra-territorial yet intimate character affects the credibility and circulation of knowledge along science's frontiers. The challenge of making a home in the (non-temperate) field and the mundane experiences of expatriation and appropriation establish particular political dynamics of knowledge-making in these locations. They bring into focus the imaginaries of nature and science that drive transnational research and put into relief the aesthetic and affective dimensions of work and life in these distant homes for science. All these themes are pursued and amplified in a different medium by the artists who contributed to our research and are also featured in this special issue.

Social Work and Science

Science.gov (United States)

Gehlert, Sarah

2016-01-01

Interest has grown in the past few years about the place of social work in science. Questions remain, such as whether social work should be considered a science, and if so, where it fits into the constellation of sciences. This article attempts to shed light on these questions. After briefly considering past and present constructions of science…

NASA IceBridge and PolarTREC - Education and Outreach Partnership

Science.gov (United States)

Bartholow, S.; Warburton, J.; Beck, J.; Woods, J. E.

2015-12-01

PolarTREC-Teachers and Researchers Exploring and Collaborating, a teacher professional development program, began with the International Polar Year in 2004 and continues today in the United States. PolarTREC has worked specifically with OIB for 3 years and looking forward to ongoing collaboration. PolarTREC brings U.S. K­12 educators and polar researchers together through an innovative teacher research experience model. Participating teachers spend 3-6 weeks in the field with research teams conducting surveys and collecting data on various aspects of polar science. During their experience, teachers become research team members filling a variety of roles on the team. They also fulfill a unique role of public outreach officer, conducting live presentations about their field site and research as well as journaling, answering questions, and posting photos. Working with OIB has opened up the nature of science for the participating teachers. In developing the long-term relationship with OIB teams, teachers can now share (1) the diversity of training, backgrounds, and interests of OIB scientists, (2) identify the linkages between Greenlandic culture and community and cryospheric science and evidence of climate change, (3) network with Danish and Greenlandic educators on the mission (4) gain access to the full spectrum of a science project - development, implementation, analysis, networking, and dissemination of information. All aspects help these teachers become champions of NASA science and educational leaders in their communities. Evaluation data shows that PolarTREC has clearly achieved it goals with the OIB partnership and suggests that linking teachers and researchers can have the potential to transform the nature of science education. By giving teachers the content knowledge, pedagogical tools, confidence, understanding of science in the broader society, and experiences with scientific inquiry, participating teachers are using authentic scientific research in their

Real-Time Science Operations to Support a Lunar Polar Volatiles Rover Mission

Science.gov (United States)

Heldmann, Jennifer L.; Colaprete, Anthony; Elphic, Richard C.; Mattes, Greg; Ennico, Kimberly; Fritzler, Erin; Marinova, Margarita M.; McMurray, Robert; Morse, Stephanie; Roush, Ted L.;

PolarTREC-Celebrating the Legacy of the IPY Through Researcher-Educator Partnerships

Science.gov (United States)

Timm, K.; Warburton, J.; Larson, A. M.

2009-12-01

Polar TREC-Teachers and Researchers Exploring and Collaborating, a three-year (2007-2009) NSF-funded program, has matched over 40 teachers with polar researchers working in multiple scientific disciplines for 2-8 week Teacher Research Experiences (TRE) in the Arctic and Antarctica during the IPY. PolarTREC contributes to the legacy of the IPY through the creation and dissemination of polar education resources, prolonged teacher-researcher relationships, and contributions to scholarly knowledge on the impacts of TRE's. Products developed during PolarTREC are helping to sustain the widespread interest and enthusiasm in the polar regions generated during the IPY. During their expeditions, participating teachers brought science and information about profound changes at the poles to school, community, and professional audiences through web-based communications, journals, discussion forums, multimedia, and live events. PolarTREC teachers constructed nearly 100 classroom lesson plans and activities as products of their experiences. Live events from the field attracted over 11,000 participants, primarily K-12 students. Although the field experience is central to the PolarTREC TRE Model, many participants cite the relationship they built with their teacher/researcher as one of the best outcomes. Through personal communications, presentations at professional conferences, and continued support of each other’s work through classroom visits or joint proposal development, teachers and researchers have maintained the mutually beneficial relationships established during the IPY. Participating scientists gained access to professional educators with expertise in translating research approaches and results into programs. The need for researchers to explain their research and “boil it down to the raw essence” helped many see how their work fits into a bigger picture, often helping them communicate outside their scientific discipline and to diverse public audiences. Teachers, on

The Big Science Questions About Mercury's Ice-Bearing Polar Deposits After MESSENGER

Science.gov (United States)

Chabot, N. L.; Lawrence, D. J.

2018-05-01

Mercury’s polar deposits provide many well-characterized locations that are known to have large expanses of exposed water ice and/or other volatile materials — presenting unique opportunities to address fundamental science questions.

Integrating Felting in Elementary Science Classrooms to Facilitate Understanding of the Polar Auroras

Directory of Open Access Journals (Sweden)

Brandy Terrill

2017-10-01

Full Text Available The Next Generation Science Standards (NGSS emphasize conceptual science instruction that draws on students’ ability to make observations, explain natural phenomena, and examine concept relationships. This paper explores integrating the arts, in the form of felting, in elementary science classrooms as a way for students to model and demonstrate understanding of the complex scientific processes that cause the polar auroras. The steps for creating felting, and using the felting artwork students create for assessing science learning, are described.

Advanced research capabilities for neutron science and technology: Neutron polarizers for neutron scattering

International Nuclear Information System (INIS)

Penttila, S.I.; Fitzsimmons, M.R.; Delheij, P.J.

1998-01-01

The authors describe work on the development of polarized gaseous 3 He cells, which are intended for use as neutron polarizers. Laser diode arrays polarize Rb vapor in a sample cell and the 3 He is polarized via collisions. They describe development and tests of such a system at LANSCE

Communicating polar sciences to school children through a scientific expedition

Science.gov (United States)

Lacarra, Maite; Lamarque, Gaelle; Koenig, Zoé; Bourgain, Pascaline; Mathilde Thierry, Anne

2015-04-01

APECS-France, the French national committee of the Association of Polar Early Career Scientists (APECS), was created in 2013 to improve the dissemination of polar sciences towards the general public and school children in particular, through activities developed in French for French schools. During the autumn of 2014, a young polar oceanographer from the University Pierre and Marie Curie, Zoé Koenig, participated in an expedition on board a sailing vessel in the Southern Ocean. APECS-France set up a new education and outreach project called "Zoé en Expé". Using different media, about 800 children, aged 6 to 12, and from 40 schools, were actively involved in the project. Interactions between Zoé and the students occurred before, during, and after the expedition, through a newsletter, a blog updated in real-time during the expedition, webinars (interactive video-conferences), and visits in classrooms when possible. Teachers were given a list of websites dedicated to polar and oceanographic science outreach and activities adapted to the age and level of the students were offered. Different activities were developed around the expedition, depending on teachers' objectives and children affinities. In particular, students were able to relate to the expedition by imagining a day in the life of Chippy, the mascot of the expedition. They were then asked to draw and/or write Chippy's adventures. APECS-France is now planning to edit a children's book using students' drawings as well as photographs taken during the expedition. Older students were also able to follow in real-time sensors released in the Southern Ocean by Zoé, measuring salinity and temperature. Throughout this 3-month project, children were able to study a wide range of topics (oceanography, biology, history, geography…). The expedition and the educational project allowed raising the awareness of children about the fragile and badly known Antarctic environment.

Improving Geoscience Education through the PolarTREC Teacher Research Experience Model (Invited)

Science.gov (United States)

Warburton, J.; Timm, K.; Larson, A. M.

2010-12-01

Teacher Research Experiences (TRE’s) are not new. For more than a decade, the National Science Foundation (NSF) as well as other federal agencies have been funding programs that place teachers with researchers in efforts to invigorate science education by bringing educators and researchers together through hands-on experiences. Many of the TRE’s are successful in providing a hands-on field experience for the teachers and researchers however many of the programs lack the resources to continue the collaborations and support the growing network of teachers that have had these field experiences. In 2007, NSF provided funding for PolarTREC—Teachers and Researchers Exploring and Collaborating, a program of the Arctic Research Consortium of the U.S. (ARCUS). PolarTREC is a TRE where K-12 teachers participate in polar field research, working closely with scientists as a pathway to improving science education. In just three years, it has become a successful TRE. What makes PolarTREC different than other the teacher research experience programs and how can others benefit from what we have learned? During this presentation, we will share data collected through the program evaluation and on how PolarTREC contributes to the discipline of Science, Technology, Engineering, and Mathematics (STEM) education and pedagogy through a model program conceived and organized according to current best practices, such as pre-research training, mentoring, support for classroom transfer, and long-term access to resources and support. Data shows that PolarTREC’s comprehensive program activities have many positive impacts on educators and their ability to teach science concepts and improve their teaching methods. Additionally, K-12 students polled in interest surveys showed significant changes in key areas including amount of time spent in school exploring research activities, importance of understanding science for future work, importance of understanding the polar regions as a person

Antarctic Super Heroes: Using a Graphic Novel to Teach Students About Polar Science. (Invited)

Science.gov (United States)

Lougheed, V.; Palsole, S.; Rojas, C.; Tweedie, C. E.

2009-12-01

The University of Texas at El Paso received an IPY grant from the US National Science Foundation to take undergraduate and graduate students, as well as teachers, to Antarctica over winter break 2007. The program, called IPY-ROAM (International Polar Year - Research and Educational Experiences in Antarctica for Minorities) aimed to increase the number of underrepresented minorities in the sciences, and increase public awareness about the polar regions. Education and outreach activities have been designed to teach people of all ages about polar science. For example, an interactive museum exhibit was designed to describe how the polar regions are being affected by climate change, and how individuals can make a difference. Our latest outreach strategy involves taking the large amount of educational materials collected for the museum display and making it available to a broader audience. We have created a graphic novel where the story of the ROAM Antarctic trip and existing educational materials are communicated using a combination of comic strips, fact sheets, and classroom activities. Photographic images from the ROAM trip were digitized and converted to a comic strip format. These images were combined with text from film footage collected by a documentary film, as well as personal anecdotes, to convey the successes of the program and the primary messages participants wanted to share with the public. The graphic novel will be made available to local school groups and online, at our website: www.ipyroam.org.

PoLAR Voices: Informing Adult Learners about the Science and Story of Climate Change in the Polar Regions Through Audio Podcast

Science.gov (United States)

Quinney, A.; Murray, M. S.; Gobroski, K. A.; Topp, R. M.; Pfirman, S. L.

2015-12-01

The resurgence of audio programming with the advent of podcasting in the early 2000s spawned a new medium for communicating advances in science, research, and technology. To capitalize on this informal educational outlet, the Arctic Institute of North America partnered with the International Arctic Research Center, the University of Alaska Fairbanks, and the UA Museum of the North to develop a podcast series called PoLAR Voices for the Polar Learning and Responding (PoLAR) Climate Change Education Partnership. PoLAR Voices is a public education initiative that uses creative storytelling and novel narrative structures to immerse the listener in an auditory depiction of climate change. The programs will feature the science and story of climate change, approaching topics from both the points of view of researchers and Arctic indigenous peoples. This approach will engage the listener in the holistic story of climate change, addressing both scientific and personal perspectives, resulting in a program that is at once educational, entertaining and accessible. Feedback is being collected at each stage of development to ensure the content and format of the program satisfies listener interests and preferences. Once complete, the series will be released on thepolarhub.org and on iTunes. Additionally, blanket distribution of the programs will be accomplished via radio broadcast in urban, rural and remote areas, and in multiple languages to increase distribution and enhance accessibility.

Providing a Continuum of Leadership in Polar Science - An IPY Legacy

Science.gov (United States)

Baeseman, J.

2008-12-01

The Association of Polar Early Career Scientists (APECS) grew out of the 4th International Polar Year (IPY-4) 2007-08 and is an international and interdisciplinary organization of over 1200 undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and others with interests in Polar Regions and the wider cryosphere from more than 40 countries. Our aims are to stimulate interdisciplinary and international research collaborations, and develop effective future leaders in polar research, education and outreach. As potentially one of the major legacies of IPY-4, APECS members have been at the forefront of increasing scientific knowledge and public interest in the polar regions, centered around global climate change, and enhancing scientific understanding, media attention, primary and secondary school (K-12) educational programs, and public literacy campaigns. Research and Educational Outreach activities by APECS members during IPY-4 have improved both our understanding and the communication of all aspects of the Polar Regions and the importance of their broader global connections. APECS National Committees have run Polar Contests where young researchers partnered with teachers and students to develop curriculum and activities to share their research, have participated in many field based communication exchanges and are mentoring youth to pursue careers in science, and enhancing the public perception of scientists through photo, video and museum exhibits. In cooperation with the IPY Teachers Network and the IPY IPO, APECS is developing a polar education resource book that will feature education and outreach activities by young researchers, as well as provide examples of classroom activities for teachers to incorporate polar literacy into their curriculum and a 'how to' guide for researchers interested in conducting education and outreach. As young researchers share their excitement and experiences in deepening our understanding of the

Fostering science communication and outreach through video production in Dartmouth's IGERT Polar Environmental Change graduate program

Science.gov (United States)

Hammond Wagner, C. R.; McDavid, L. A.; Virginia, R. A.

2013-12-01

Dartmouth's NSF-supported IGERT Polar Environmental Change graduate program has focused on using video media to foster interdisciplinary thinking and to improve student skills in science communication and public outreach. Researchers, educators, and funding organizations alike recognize the value of video media for making research results more accessible and relevant to diverse audiences and across cultures. We present an affordable equipment set and the basic video training needed as well as available Dartmouth institutional support systems for students to produce outreach videos on climate change and its associated impacts on people. We highlight and discuss the successes and challenges of producing three types of video products created by graduate and undergraduate students affiliated with the Dartmouth IGERT. The video projects created include 1) graduate student profile videos, 2) a series of short student-created educational videos for Greenlandic high school students, and 3) an outreach video about women in science based on the experiences of women students conducting research during the IGERT field seminar at Summit Station and Kangerlussuaq, Greenland. The 'Science in Greenland--It's a Girl Thing' video was featured on The New York Times Dot Earth blog and the Huffington Post Green blog among others and received international recognition. While producing these videos, students 1) identified an audience and created story lines, 2) worked in front of and behind the camera, 3) utilized low-cost digital editing applications, and 4) shared the videos on multiple platforms from social media to live presentations. The three video projects were designed to reach different audiences, and presented unique challenges for content presentation and dissemination. Based on student and faculty assessment, we conclude that the video projects improved student science communication skills and increased public knowledge of polar science and the effects of climate change.

Future Marine Polar Research Capacities - Science Planning and Research Services for a Multi-National Research Icebreaker

Science.gov (United States)

Biebow, N.; Lembke-Jene, L.; Wolff-Boenisch, B.; Bergamasco, A.; De Santis, L.; Eldholm, O.; Mevel, C.; Willmott, V.; Thiede, J.

2011-12-01

Despite significant advances in Arctic and Antarctic marine science over the past years, the polar Southern Ocean remains a formidable frontier due to challenging technical and operational requirements. Thus, key data and observations from this important region are still missing or lack adequate lateral and temporal coverage, especially from time slots outside optimal weather seasons and ice conditions. These barriers combined with the obligation to efficiently use financial resources and funding for expeditions call for new approaches to create optimally equipped, but cost-effective infrastructures. These must serve the international science community in a dedicated long-term mode and enable participation in multi-disciplinary expeditions, with secured access to optimally equipped marine platforms for world-class research in a wide range of Antarctic science topics. The high operational and technical performance capacity of a future joint European Research Icebreaker and Deep-sea Drilling Vessel (the AURORA BOREALIS concept) aims at integrating still separately operating national science programmes with different strategic priorities into joint development of long-term research missions with international cooperation both in Arctic and Antarctica. The icebreaker is planned to enable, as a worldwide first, autonomous year-round operations in the central Arctic and polar Southern Ocean, including severest ice conditions in winter, and serving all polar marine disciplines. It will facilitate the implementation of atmospheric, oceanographic, cryospheric or geophysical observatories for long-term monitoring of the polar environment. Access to the biosphere and hydrosphere e.g. beneath ice shelves or in remote regions is made possible by acting as advanced deployment platform for instruments, robotic and autonomous vehicles and ship-based air operations. In addition to a report on the long-term strategic science and operational planning objectives, we describe foreseen

Bringing Society to a Changing Polar Ocean: Polar Interdisciplinary Coordinated Education (ICE)

Science.gov (United States)

Schofield, O.

2015-12-01

Environmental changes in the Arctic and Antarctic appear to be accelerating and scientists are trying to understand both the patterns and the impacts of change. These changes will have profound impact on humanity and create a need for public education about these critical habitats. We have focused on a two-pronged strategy to increase public awareness as well as enable educators to discuss comfortably the implications of climate change. Our first focus is on entraining public support through the development of science documentaries about the science and people who conduct it. Antarctic Edge is a feature length award-winning documentary about climate change that has been released in May 2015 and has garnered interest in movie theatres and on social media stores (NetFlix, ITunes). This broad outreach is coupled with our group's interest assisting educators formally. The majority of current polar education is focused on direct educator engagement through personal research experiences that have impact on the participating educators' classrooms. Polar Interdisciplinary Coordinated Education (ICE) proposes to improve educator and student engagement in polar sciences through exposure to scientists and polar data. Through professional development and the creation of data tools, Polar ICE will reduce the logistical costs of bringing polar science to students in grades 6-16. We will provide opportunities to: 1) build capacity of polar scientists in communicating and engaging with diverse audiences; 2) create scalable, in-person and virtual opportunities for educators and students to engage with polar scientists and their research through data visualizations, data activities, educator workshops, webinars, and student research symposia; and 3) evaluate the outcomes of Polar ICE and contribute to our understanding of science education practices. We will use a blended learning approach to promote partnerships and cross-disciplinary sharing. This combined multi-pronged approach

The Science of Social Work and Its Relationship to Social Work Practice

Science.gov (United States)

Anastas, Jeane W.

2014-01-01

As John Brekke has observed, social work does not use the word "science" to define itself, suggesting a need to articulate a science of social work. This article discusses the science of social work and its relationship to social work practice in the United States, arguing that a "rapprochement" between practice and science…

The International Polar Year in Portugal: A New National Polar Programme and a Major Education and Outreach project

Science.gov (United States)

Mendes-Victor, L.; Vieira, G.; Xavier, J.; Canario, A.

2008-12-01

Before the International Polar Year, in Portugal polar research was conducted by a very small group of scientists integrated in foreign projects or research institutions. Portugal was not member of the Scientific Committee for Antarctic Research (SCAR), the European Polar Board (EPB), neither a subscriber of the Antarctic Treaty. In 2004 Portuguese Polar researchers considered the IPY as an opportunity to change this situation and organized the national Committee for the IPY. The objectives were ambitious: to answer the aforementioned issues in defining and proposing a National Polar Programme. In late 2008, close to the end of the IPY, the objectives were attained, except the Antarctic Treaty signature that is, however, in an advanced stage, having been approved by consensus at the National Parliament in early 2007. Portugal joined SCAR in July 2006, the EPB in 2007 and a set of 5 Antarctic research projects forming the roots of the National Polar Programme (ProPolar) have been approved by the Foundation for Science and Technology (FCT-MCTES). Scientifically, the IPY can already be considered a major success in Portugal with an improvement in polar scientific research, in the number of scientists performing field work in the Antarctic, organizing polar science meetings and producing an expected increase in the number of polar science peer- reviewed papers. The Portuguese IPY scientific activities were accompanied by a major education and outreach project funded by the Agencia Ciência Viva (MCTES): LATITUDE60! Education for the Planet in the IPY. This project lead by the universities of Algarve, Lisbon and by the Portuguese Association of Geography Teachers is heavily interdisciplinary, programmed for all ages, from kindergarten to adults, and hoped to bring together scientists and society. LATITUDE60! was a major success and focussed on showing the importance of the polar regions for Earth's environment, emphasising on the implications of polar change for

PolarHub: A Global Hub for Polar Data Discovery

Science.gov (United States)

Li, W.

2014-12-01

This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

Our Polar Past

Science.gov (United States)

Clary, Renee; Wandersee, James

2009-01-01

The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

Broadband working-waveband-tunable polarization converter based on anisotropic metasurface

Science.gov (United States)

Lin, Yu; Wang, Lei; Gao, Jun; Lu, Yichao; Jiang, Suhua; Zeng, Wei

2017-03-01

We experimentally and theoretically demonstrate an ultrathin, broadband, and highly efficient metamaterial-based polarization converter with a metasurface/insulator/metal (MIM) configuration. In such a system, the resonance undergoes a transition from a vertical Fabry-Pérot type to a transverse type as the spacer thickness decreases. By changing the spacer thickness from 1 to 15 mm, the working waveband of this device could be tuned from 10.9-12.9 to 6-8 GHz without compromising the polarization conversion efficiency. Equivalent circuit theory and the transfer matrix method are used for demonstrating the physical mechanism of our device.

APECS: A Model Organization for Bridging Past to Present and Developing a New Generation of Polar Scientists (Invited)

Science.gov (United States)

Timm, K.; Baeseman, J. L.; Membership, Association Of Polar Early Career Scientists

2010-12-01

One of the greatest legacies of the International Polar Year (IPY) is the creation of APECS, the Association of Polar Early Career Scientists. As a grassroots effort, APECS was proposed, formed, and developed by and for early career polar researchers. While the young investigators who founded APECS had talent, ambition, and the desire to make things happen, partnerships with key organizations and experienced leaders in polar science were essential to provide the funding, leadership, and mentorship that has taken the organization well beyond the IPY and to over 2000 members. In four years, APECS has strived to foster the skills of and develop a group of early career interdisciplinary polar scientists through networking and mentoring among themselves and with senior scientists. Through diverse activities including, panel discussions, career development workshops, online seminars, a comprehensive job listing, formal mentoring, meeting travel support, and the APECS Virtual Poster Session, APECS goal is to support the early career researcher being trained to do the science, to become a well-rounded scientist prepared for 21st century careers in science. As part of that training, APECS members are encouraged to participate in activities and training related to science communication, education, and outreach; working with the media; participating in the science / public policy interface; and working with arctic communities and indigenous peoples. During the IPY, APECS members were guest speakers and presenters on International Polar Day activities; they contributed to resources for education and outreach such as the book: Polar Science and Global Climate: An International Resource for Education and Outreach; and they made connections with educators, community groups, the media through in-person presentations, blogs from the field, videos, and much more. Workshops, panels, and online discussions focusing on these activities helped develop the capacity to conduct such

Operationalizing Social Work Science through Research-Practice Partnerships: Lessons from Implementation Science

Science.gov (United States)

Palinkas, Lawrence A.; He, Amy S.; Choy-Brown, Mimi; Hertel, Amy Locklear

2017-01-01

Recent efforts to identify and promote a distinct science for the discipline of social work have led to an ongoing debate regarding the nature and function of such a science. Central to this debate is a lack of consensus as to how to operationalize a social work science. Drawing from the field of implementation science and its application in…

The United States Polar Rock Repository: A geological resource for the Earth science community

Science.gov (United States)

Grunow, Annie M.; Elliot, David H.; Codispoti, Julie E.

2007-01-01

The United States Polar Rock Repository (USPRR) is a U. S. national facility designed for the permanent curatorial preservation of rock samples, along with associated materials such as field notes, annotated air photos and maps, raw analytic data, paleomagnetic cores, ground rock and mineral residues, thin sections, and microfossil mounts, microslides and residues from Polar areas. This facility was established by the Office of Polar Programs at the U. S. National Science Foundation (NSF) to minimize redundant sample collecting, and also because the extreme cold and hazardous field conditions make fieldwork costly and difficult. The repository provides, along with an on-line database of sample information, an essential resource for proposal preparation, pilot studies and other sample based research that should make fieldwork more efficient and effective. This latter aspect should reduce the environmental impact of conducting research in sensitive Polar Regions. The USPRR also provides samples for educational outreach. Rock samples may be borrowed for research or educational purposes as well as for museum exhibits.

How to Teach High-School Students "How Science Really Works?"

Science.gov (United States)

Losiak, Anna; Students, High-School; Winiarska, Anna; Parys-Wasylkiewicz, Magdalena

2016-04-01

terrestrial glaciers and Martian North Polar Residual Cap. 3) Students were responsible for physically preparing scientific equipment (within a given budget). 4) Students prepared detailed procedures which were used during the experiment. The experiment was performed by the Austrian Space Forum analog astronauts during the Mars Analog Mission AMADEE-15 between 2nd and 14th of August 2015 at the Kaunertal Glacier in Austria. 5) During and after the mission students analyzed data collected during the experiment. 6) Students presented their findings during the regional science fair (Dolnoslaski Festiwal Nauki). Despite the fact the quality of the data produced during the experiment was not satisfactory, the project was a success in terms of explaining students "How Science Really Works" (e.g., how much depends on the properly designed and executed procedures).

Enhancement of molecular NMR signal induced by polarization transfer from laser-polarized 129Xe

International Nuclear Information System (INIS)

Sun Xianping

2001-01-01

There is a large non-equilibrium nuclear polarization and a longer relaxation time in the laser-polarized 129 Xe produced by means of optical pumping and spin exchange. The characteristics of the laser-polarized 129 Xe permit the transfer of the polarization to enhance the atomic nuclear spin in liquid, solid and surface of solid molecules. Therefore, the sensitivity in nuclear magnetic resonance measurements for the molecules is enhanced and applications in the investigations of materials and surface sciences are expanded. The progress in the investigations of materials and surface sciences are expanded. The progress in the investigations of the polarization transfer between laser-polarized 129 Xe and the atomic nuclei in the molecules, the relative physics and the measurement of some parameters are introduced

Climate Comics: polar research in a cartoon form

Science.gov (United States)

Courville, Z.; Carbaugh, S.; Defrancis, G.; Donegan, R.; Brown, C.; Perovich, D. K.; Richter-Menge, J.

2013-12-01

Climate Comics is a collaborative outreach effort between the Montshire Museum of Science, in Norwich, VT, the Cold Regions Research and Engineering Laboratory (CRREL) research staff, and freelance artist and recent graduate of the Center for Cartoon Studies in White River Junction, VT, Sam Carbaugh. The project involves the cartoonist, the education staff from the museum, and researchers from CRREL creating a series of comic books with polar science and research themes, including sea ice monitoring, sea ice albedo, ice cores, extreme microbial activity, and stories and the process of fieldwork. The aim of the comic series is to provide meaningful science information in a comic-format that is both informative and fun, while highlighting current polar research work done at the lab. The education staff at the Montshire Museum develops and provides a series of hands-on, inquiry-based activity descriptions to complement each comic book, and CRREL researchers provide science background information and reiterative feedback about the comic books as they are being developed. Here, we present the motivation for using the comic-book medium to present polar research topics, the process involved in creating the comics, some unique features of the series, and the finished comic books themselves. Cartoon illustrating ways snow pack can be used to determine past climate information.

2011 Joint Science Education Project: Research Experience in Polar Science

Science.gov (United States)

Wilkening, J.; Ader, V.

2011-12-01

The Joint Science Education Project (JSEP), sponsored by the National Science Foundation, is a two-part program that brings together students and teachers from the United States, Greenland, and Denmark, for a unique cross-cultural, first-hand experience of the realities of polar science field research in Greenland. During JSEP, students experienced research being conducted on and near the Greenland ice sheet by attending researcher presentations, visiting NSF-funded field sites (including Summit and NEEM field stations, both located on the Greenland ice sheet), and designing and conducting research projects in international teams. The results of two of these projects will be highlighted. The atmospheric project investigated the differences in CO2, UVA, UVB, temperature, and albedo in different Arctic microenvironments, while also examining the interaction between the atmosphere and water present in the given environments. It was found that the carbon dioxide levels varied: glacial environments having the lowest levels, with an average concentration of 272.500 ppm, and non-vegetated, terrestrial environments having the highest, with an average concentration of 395.143 ppm. Following up on these results, it is planned to further investigate the interaction of the water and atmosphere, including water's role in the uptake of carbon dioxide. The ecology project investigated the occurrence of unusual large blooms of Nostoc cyanobacteria in Kangerlussuaq area lakes. The water chemistry of the lakes which contained the cyanobacteria and the lakes that did not were compared. The only noticeable difference was of the lakes' acidity, lakes containing the blooms had an average pH value of 8.58, whereas lakes without the blooms had an average pH value of 6.60. Further investigation of these results is needed to determine whether or not this was a cause or effect of the cyanobacteria blooms. As a next step, it is planned to attempt to grow the blooms to monitor their effects on

Polarization recovery through scattering media.

Science.gov (United States)

de Aguiar, Hilton B; Gigan, Sylvain; Brasselet, Sophie

2017-09-01

The control and use of light polarization in optical sciences and engineering are widespread. Despite remarkable developments in polarization-resolved imaging for life sciences, their transposition to strongly scattering media is currently not possible, because of the inherent depolarization effects arising from multiple scattering. We show an unprecedented phenomenon that opens new possibilities for polarization-resolved microscopy in strongly scattering media: polarization recovery via broadband wavefront shaping. We demonstrate focusing and recovery of the original injected polarization state without using any polarizing optics at the detection. To enable molecular-level structural imaging, an arbitrary rotation of the input polarization does not degrade the quality of the focus. We further exploit the robustness of polarization recovery for structural imaging of biological tissues through scattering media. We retrieve molecular-level organization information of collagen fibers by polarization-resolved second harmonic generation, a topic of wide interest for diagnosis in biomedical optics. Ultimately, the observation of this new phenomenon paves the way for extending current polarization-based methods to strongly scattering environments.

The anxieties of a science diplomat: field coproduction of climate knowledge and the rise and fall of Hans Ahlmann's polar warming".

Science.gov (United States)

Sörlin, Sverker

2011-01-01

In the decades between the world wars there were several attempts to document and explain perceived tendencies of atmospheric warming. Hans Ahlmann, a seminal figure in modern glaciology and a science policy adviser and diplomat, constructed a theory of "polar warming" using field results from glacier melting in the Arctic. This article aims to link the rise and fall of "polar warming" with Ahlmann's style of fieldwork. In Ahlmann's view, fieldwork should (1) enhance credibility of polar climate science by emulating laboratory methods and (2) secure knowledge in remote places through collaboration with local residents and fieldworkers. The bodily nature of this style of knowledge production turned out to be an asset in establishing Ahlmann's theory of polar warming but ultimately proved nonresilient to theories of anthropogenic climate change, which became influential from the 1950s onward.

Recent advance in polar seismology: Global impact of the International Polar Year

Science.gov (United States)

Kanao, Masaki; Zhao, Dapeng; Wiens, Douglas A.; Stutzmann, Éléonore

2015-03-01

The most exciting initiative for the recent polar studies was the International Polar Year (IPY) in 2007-2008. The IPY has witnessed a growing community of seismologists who have made considerable efforts to acquire high-quality data in polar regions. It also provided an excellent opportunity to make significant advances in seismic instrumentation of the polar regions to achieve scientific targets involving global issues. Taking these aspects into account, we organize and publish a special issue in Polar Science on the recent advance in polar seismology and cryoseismology as fruitful achievements of the IPY.

Disseminated Museum Displays and Participation of Students from Underrepresented Populations in Polar Research: Education and Outreach for Joint Projects in GPS and Seismology Solid Earth Science Community

Science.gov (United States)

Eriksson, S. C.; Wilson, T. J.; Anandakrishnan, S.; Aster, R. C.; Johns, B.; Anderson, K.; Taber, J.

2006-12-01

Two Antarctic projects developed by solid earth scientists in the GPS and seismology communities have rich education and outreach activities focused on disseminating information gleaned from this research and on including students from underrepresented groups. Members of the UNAVCO and IRIS research consortia along with international partners from Australia, Canada, Chile, Germany, Italy, New Zealand and the U.K. aim to deploy an ambitious GPS/seismic network to observe the Antarctic glaciological and geologic system using a multidisciplinary and internationally coordinated approach. The second project supports this network. UNAVCO and IRIS are designing and building a reliable power and communication system for autonomous polar station operation which use the latest power and communication technologies for ease of deployment and reliable multi-year operation in severe polar environments. This project will disseminate research results through an IPY/POLENET web-based museum style display based on the next-generation "Museum Lite" capability primarily supported by IRIS. "Museum Lite" uses a standard PC, touch-screen monitor, and standard Internet browsers to exploit the scalability and access of the Internet and to provide customizable content in an interactive setting. The unit is suitable for research departments, public schools, and an assortment of public venues, and can provide wide access to real-time geophysical data, ongoing research, and general information. The POLENET group will work with members of the two consortia to provide content about the project and polar science in general. One unit is to be installed at Barrow's Ilisagvit College through the Barrow Arctic Science Consortium, one at McMurdo Station in Antarctica, and two at other sites to be determined (likely in New Zealand/Australia and in the U.S.). In January, 2006, Museum Lite exhibit was installed at the Amundsen-Scott South Pole Station. Evaluation of this prototype is underway. These

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

Energy Technology Data Exchange (ETDEWEB)

Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

2012-08-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

International Nuclear Information System (INIS)

Abeyratne, S.; Accardi, A.; Ahmed, S.; Barber, D.; Bisognano, J.; Bogacz, A.; Castilla, A.; Chevtsov, P.; Corneliussen, S.; Deconinck, W.; Degtiarenko, P.; Delayen, J.; Derbenev, Ya.; DeSilva, S.; Douglas, D.; Dudnikov, V.; Ent, R.; Erdelyi, B.; Evtushenko, P.; Fujii, Yu; Filatov, Yury; Gaskell, D.; Geng, R.; Guzey, V.; Horn, T.; Hutton, A.; Hyde, C.; Johnson, R.; Kim, Y.; Klein, F.; Kondratenko, A.; Kondratenko, M.; Krafft, G.; Li, R.; Lin, F.; Manikonda, S.; Marhauser, F.; McKeown, R.; Morozov, V.; Dadel-Turonski, P.; Nissen, E.; Ostroumov, P.; Pivi, M.; Pilat, F.; Poelker, M.; Prokudin, A.; Rimmer, R.; Satogata, T.; Sayed, H.; Spata, M.; Sullivan, M.; Tennant, C.; Terzic, B.; Tiefenback, M.; Wang, H.; Wang, S.; Weiss, C.; Yunn, B.; Zhang, Y.

2012-01-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very

Lowering the barriers for accessing distributed geospatial big data to advance spatial data science: the PolarHub solution

Science.gov (United States)

Li, W.

2017-12-01

Data is the crux of science. The widespread availability of big data today is of particular importance for fostering new forms of geospatial innovation. This paper reports a state-of-the-art solution that addresses a key cyberinfrastructure research problem—providing ready access to big, distributed geospatial data resources on the Web. We first formulate this data-access problem and introduce its indispensable elements, including identifying the cyber-location, space and time coverage, theme, and quality of the dataset. We then propose strategies to tackle each data-access issue and make the data more discoverable and usable for geospatial data users and decision makers. Among these strategies is large-scale web crawling as a key technique to support automatic collection of online geospatial data that are highly distributed, intrinsically heterogeneous, and known to be dynamic. To better understand the content and scientific meanings of the data, methods including space-time filtering, ontology-based thematic classification, and service quality evaluation are incorporated. To serve a broad scientific user community, these techniques are integrated into an operational data crawling system, PolarHub, which is also an important cyberinfrastructure building block to support effective data discovery. A series of experiments were conducted to demonstrate the outstanding performance of the PolarHub system. We expect this work to contribute significantly in building the theoretical and methodological foundation for data-driven geography and the emerging spatial data science.

Training the New Generation of Polar Researchers

Science.gov (United States)

Drobot, S.; Weiler, C. S.

2008-12-01

The polar regions are changing rapidly, and many of the pressing problems faced in the future will require a new generation of polar researchers to be disciplinary experts and work across traditional disciplinary boundaries to conduct socially relevant, transformative research, and translate it to more effective action. To learn about the past and better address these new challenges, a select international group of 35 students and early career researchers who are conducting research during the 2007-2009 International Polar Year were brought together May 4-11, 2008, at the La Foret Conference Center for the New Generation Polar Research (NGPR) Symposium. The participants were drawn from professional backgrounds spanning the spectrum of social, natural, and physical sciences and represented the research programs of 7 countries. In addition to the participants, 12 mentors, some of whom participated in the IGY, shared insights, stories, and expertise. This diverse and ambitious group spent an intensive week learning about many important aspects of IPY history and research, along with communication, outreach, interdisciplinary research and career development. Each of the participants presented a 7-minute overview of his or her IPY research and provided details and discussion in evening poster sessions. Polar history provided an informative and unifying context for discussions of the past, present, and future that lasted throughout the week. Mentors and guest speakers shared insights and advice on media interactions, and many participants were subsequently interviewed for an upcoming radio story to be aired on National Public Radio. Several presentations on outreach were followed by a hands-on session for a group 1st grade students who were visiting the La Foret Conference Center. The Symposium also featured several break-out sessions, where small groups of participants and mentors discussed challenges related to interdisciplinary research, science advocacy, and

"Live from IPY"--Connecting Students, Teachers and the Public to Polar Research

Science.gov (United States)

Breen, K.; Warnick, W. K.; Warburton, J.; Fischer, K.; Wiggins, H.

2007-12-01

PolarTREC-Teachers and Researchers Exploring and Collaborating is a three-year (2007-2009) teacher professional development program of the Arctic Research Consortium of the U.S. (ARCUS) that pairs K-12 teachers with researchers to improve science education through authentic polar research experiences. Each year of PolarTREC, approximately 15 teachers spend two to six weeks in the Arctic or Antarctic, working closely with researchers investigating a wide range of topics such as sea-ice dynamics, terrestrial ecology, marine biology, atmospheric chemistry, and long-term climate change. PolarTREC is funded by the National Science Foundation. While in the field, teachers and researchers communicate extensively with their colleagues, communities, and hundreds of students of all ages across the globe, using a variety of communication technologies and tools to appeal to broad student and public engagement in polar science. Through the PolarTREC website (www.polartrec.com) teachers connect from the field through the use of online journals and forums, photo galleries, podcasts, and learning resources. "Live from IPY," a key activity of PolarTREC, is a free, interactive, distance-learning experience that virtually transports students and the public to unique and remote polar locations through a live Internet interface. Rather than relying solely on the asynchronous elements of online journals, forums, photo albums, and podcasts, "Live from IPY" allows real-time interaction by adding elements including live voice, video, chat, application sharing, polling, and whiteboards, but requires only telephone and/or Internet access for participants and presenters to connect. "Live from IPY" and the online outreach elements of PolarTREC convey the excitement of polar research experiences to a broad audience far beyond the classrooms of the PolarTREC teachers, allowing anyone to join a global network of scientists, teachers, students, and communities and actively participate in the

Neutron beam effects on spin-exchange-polarized 3He.

Science.gov (United States)

Sharma, M; Babcock, E; Andersen, K H; Barrón-Palos, L; Becker, M; Boag, S; Chen, W C; Chupp, T E; Danagoulian, A; Gentile, T R; Klein, A; Penttila, S; Petoukhov, A; Soldner, T; Tardiff, E R; Walker, T G; Wilburn, W S

2008-08-22

We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal spin-exchange-polarized 3He cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable 3He polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation over a range of neutron fluxes at Los Alamos Neutron Science Center and Institute Laue-Langevin. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as sqrt[phi_{n}], where phi_{n} is the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the concentration of electron-ion pairs but is much larger than expected from earlier work.

Next Generation Polar Seismic Instrumentation Challenges

Science.gov (United States)

Parker, T.; Beaudoin, B. C.; Gridley, J.; Anderson, K. R.

2011-12-01

Polar region logistics are the limiting factor for deploying deep field seismic arrays. The IRIS PASSCAL Instrument Center, in collaboration with UNAVCO, designed and deployed several systems that address some of the logistical constraints of polar deployments. However, continued logistics' pressures coupled with increasingly ambitious science projects require further reducing the logistics required for deploying both summer and over winter stations. Our focus is to reduce station power requirements and bulk, thereby minimizing the time and effort required to deploy these arrays. We will reduce the weight of the battery bank by incorporating the most applicable new high energy-density battery technology. Using these batteries will require a completely new power management system along with an appropriate smart enclosure. The other aspect will be to integrate the digitizing system with the sensor. Both of these technologies should reduce the install time and shipping volume plus weight while reducing some instrument costs. We will also continue work on an effective Iridium telemetry solution for automated data return. The costs and limitations of polar deep-field science easily justifies a specialized development effort but pays off doubly in that we will continue to leverage the advancements in reduced logistics and increased performance for the benefit of low-latitude seismic research.

To the Extremes! A Teacher Research Experience Program in the Polar Regions

Science.gov (United States)

Warburton, J.; Bartholow, S.

2014-12-01

PolarTREC-Teachers and Researchers Exploring and Collaborating, a teacher professional development program, began with the International Polar Year in 2004 and continues today in the United States. In 2007, the National Science Foundation designated PolarTREC as potentially transformative, meaning that the "research results often do not fit within established models or theories and may initially be unexpected or difficult to interpret; their transformative nature and utility might not be recognized until years later." PolarTREC brings U.S. K-12 educators and polar researchers together through an innovative teacher research experience model. Teachers spend three to six weeks in remote arctic and Antarctic field camps. Since 2007, over 100 teachers have been placed in field experiences throughout the Arctic and Antarctic and with half of them participating in field experiences in Antarctica. During their experience, teachers become research team members filling a variety of roles on the team. They also fulfil a unique role of public outreach officer, conducting live presentations about their field site and research as well as journaling, answering questions, and posting photos. Evaluation data collected over the past eight years on program participants shows that PolarTREC has clearly achieved it goals and strongly suggests programs that link teachers and researchers can have the potential to transform the nature of science education. By giving teachers the content knowledge, pedagogical tools, confidence, understanding of science in the broader society, and experiences with scientific inquiry, participating teachers are using authentic scientific research in their classrooms. Not surprisingly this has also led to increases in student interest and knowledge about the Polar Regions. In this presentation, we will highlight the best practices of teacher research experiences as well as discuss why it is vital to have teachers and researchers work together to communicate

Natural Language Processing (NLP), Machine Learning (ML), and Semantics in Polar Science

Science.gov (United States)

Duerr, R.; Ramdeen, S.

2017-12-01

One of the interesting features of Polar Science is that it historically has been extremely interdisciplinary, encompassing all of the physical and social sciences. Given the ubiquity of specialized terminology in each field, enabling researchers to find, understand, and use all of the heterogeneous data needed for polar research continues to be a bottleneck. Within the informatics community, semantics has broadly accepted as a solution to these problems, yet progress in developing reusable semantic resources has been slow. The NSF-funded ClearEarth project has been adapting the methods and tools from other communities such as Biomedicine to the Earth sciences with the goal of enhancing progress and the rate at which the needed semantic resources can be created. One of the outcomes of the project has been a better understanding of the differences in the way linguists and physical scientists understand disciplinary text. One example of these differences is the tendency for each discipline and often disciplinary subfields to expend effort in creating discipline specific glossaries where individual terms often are comprised of more than one word (e.g., first-year sea ice). Often each term in a glossary is imbued with substantial contextual or physical meaning - meanings which are rarely explicitly called out within disciplinary texts; meaning which are therefore not immediately accessible to those outside that discipline or subfield; meanings which can often be represented semantically. Here we show how recognition of these difference and the use of glossaries can be used to speed up the annotation processes endemic to NLP, enable inter-community recognition and possible reconciliation of terminology differences. A number of processes and tools will be described, as will progress towards semi-automated generation of ontology structures.

Social Work Science and Knowledge Utilization

Science.gov (United States)

Marsh, Jeanne C.; Reed, Martena

2016-01-01

Objective: This article advances understanding of social work science by examining the content and methods of highly utilized or cited journal articles in social work. Methods: A data base of the 100 most frequently cited articles from 79 social work journals was coded and categorized into three primary domains: content, research versus…

The Polarity-Dependent Effects of the Bilateral Brain Stimulation on Working Memory

Directory of Open Access Journals (Sweden)

Fatemeh Keshvari

2013-08-01

Full Text Available Introduction: Working memory plays a critical role in cognitive processes which are central to our daily life. Neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (DLFPC. This study was aimed to assess whether bilateral modulation of the DLPFC using a noninvasive brain stimulation, namely transcranial direct current stimulation (tDCS, modi.es the working memory function in healthy adults.Methods: In a randomized sham-controlled cross-over study, 60 subjects (30 Males received sham and active tDCS in two subgroups (anode left/cathode right and anode right/cathode left of the DLPFC. Subjects were presented working memory n-back task while the reaction time and accuracy were recorded.Results: A repeated measures, mixed design ANOVA indicated a signi.cant difference between the type of stimulation (sham vs. active in anodal stimulation of the left DLPFC with cathodal stimulation of the right DLPFC [F(1,55= 5.29,  P=0.019], but not the inverse polarity worsened accuracy in the 2-back working memory task. There were also no statistically signi.cant changes in speed of working memory [F(1,55= 0.458 ,P=0.502] related to type or order of stimulation..Discussion: The results would imply to a polarity dependence of bilateral tDCS of working memory. Left anodal/ right cathodal stimulation of DLPFC could impair working memory, while the reverser stimulation had no effect. Meaning that bilateral stimulation of DLFC would not be a useful procedure to improve working memory. Further studies are required to understand subtle effects of different tDCS stimulation/inhibition electrode positioning on the working memory.

Working Alongside Scientists. Impacts on Primary Teacher Beliefs and Knowledge About Science and Science Education

Science.gov (United States)

Anderson, Dayle; Moeed, Azra

2017-05-01

Current curriculum demands require primary teachers to teach about the Nature of Science; yet, few primary teachers have had opportunity to learn about science as a discipline. Prior schooling and vicarious experiences of science may shape their beliefs about science and, as a result, their science teaching. This qualitative study describes the impact on teacher beliefs about science and science education of a programme where 26 New Zealand primary (elementary) teachers worked fulltime for 6 months alongside scientists, experiencing the nature of work in scientific research institutes. During the 6 months, teachers were supported, through a series of targeted professional development days, to make connections between their experiences working with scientists, the curriculum and the classroom. Data for the study consisted of mid- and end-of-programme written teacher reports and open-ended questionnaires collected at three points, prior to and following 6 months with the science host and after 6 to 12 months back in school. A shift in many teachers' beliefs was observed after the 6 months of working with scientists in combination with curriculum development days; for many, these changes were sustained 6 to 12 months after returning to school. Beliefs about the aims of science education became more closely aligned with the New Zealand curriculum and its goal of developing science for citizenship. Responses show greater appreciation of the value of scientific ways of thinking, deeper understanding about the nature of scientists' work and the ways in which science and society influence each other.

Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

Science.gov (United States)

Chandrasekaran, Ramya

Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

Extreme working hours in Western Europe and North America: A new aspect of polarization

OpenAIRE

Burger, Anna S.

2015-01-01

This paper analyzes the trends and root causes of extreme working hours in sixteen Western European countries, Canada, and the United States between 1970 and 2010. Earlier literature has revealed increasing trends in extreme working hours in the United States and recognized the negative repercussions of this new aspect of labor market polarization. As European average working hours have declined over the past decades, scholars have turned little attention to the analysis of extreme working ho...

Science, Innovation, and Social Work: Purpose: Clash or Convergence?

Science.gov (United States)

Flynn, Marilyn L.

2017-01-01

Social work as a human services profession has been distinctive for its inclusion of research as a required element of practice and instrument in instigating reform. At the present time, the relationship of social work to science and a redefinition of social work as a science have reentered our national dialogue with new force. This expansion of…

Response: From Fish and Bicycles to a Science of Social Work

Science.gov (United States)

Marsh, Jeanne Cay

2012-01-01

John Brekke challenges the field and profession of social work to define and develop the "science of social work". This response to Brekke's paper identifies the premises undergirding a discussion of the science of social work related to (1) a definition of "science";; (2 ) an organizing principle for social work; (3) a…

Teaching Political Science through Memory Work

Science.gov (United States)

Jansson, Maria; Wendt, Maria; Ase, Cecilia

2009-01-01

In this article, we present the results of a research project where we have tried to elaborate more socially inclusive ways of teaching and learning political science by making use of a specific feminist method of analyzing social relations--memory work. As a method, memory work involves writing and interpreting stories of personal experience,…

Neutron polarization in polarized 3He targets

International Nuclear Information System (INIS)

Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

1990-01-01

Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

Space Interferometry Science Working Group

Science.gov (United States)

Ridgway, Stephen T.

1992-12-01

Decisions taken by the astronomy and astrophysics survey committee and the interferometry panel which lead to the formation of the Space Interferometry Science Working Group (SISWG) are outlined. The SISWG was formed by the NASA astrophysics division to provide scientific and technical input from the community in planning for space interferometry and in support of an Astrometric Interferometry Mission (AIM). The AIM program hopes to measure the positions of astronomical objects with a precision of a few millionths of an arcsecond. The SISWG science and technical teams are described and the outcomes of its first meeting are given.

THE ROLE OF SCHOOL TECHNICIANS IN PROMOTING SCIENCE THROUGH PRACTICAL WORK

Directory of Open Access Journals (Sweden)

Anne T. Helliar

2011-11-01

Full Text Available This is a review of the role of practical work in UK’s secondary school science lessons, the impact that practical work has in the promotion of science, the challenges created through use of non-specialist science teachers and a possible additional role for science technicians. The paper considers how improved deployment of suitably experienced school science technicians and their recognition, by schools’ management, for their involvement in the delivery of training in the use of practical work, for less experienced teachers, could benefit schools and their students. This together with its companion paper endeavours to show how the more effective use of practical work and technicians can encourage more students to select science at higher, non-compulsory levels.

Packaging a successful NASA mission to reach a large audience within a small budget. Earth's Dynamic Space: Solar-Terrestrial Physics & NASA's Polar Mission

Science.gov (United States)

Fox, N. J.; Goldberg, R.; Barnes, R. J.; Sigwarth, J. B.; Beisser, K. B.; Moore, T. E.; Hoffman, R. A.; Russell, C. T.; Scudder, J.; Spann, J. F.; Newell, P. T.; Hobson, L. J.; Gribben, S. P.; Obrien, J. E.; Menietti, J. D.; Germany, G. G.; Mobilia, J.; Schulz, M.

2004-12-01

To showcase the on-going and wide-ranging scope of the Polar science discoveries, the Polar science team has created a one-stop shop for a thorough introduction to geospace physics, in the form of a DVD with supporting website. The DVD, Earth's Dynamic Space: Solar-Terrestrial Physics & NASA's Polar Mission, can be viewed as an end-to-end product or split into individual segments and tailored to lesson plans. Capitalizing on the Polar mission and its amazing science return, the Polar team created an exciting multi-use DVD intended for audiences ranging from a traditional classroom and after school clubs, to museums and science centers. The DVD tackles subjects such as the aurora, the magnetosphere and space weather, whilst highlighting the science discoveries of the Polar mission. This platform introduces the learner to key team members as well as the science principles. Dramatic visualizations are used to illustrate the complex principles that describe Earth’s dynamic space. In order to produce such a wide-ranging product on a shoe-string budget, the team poured through existing NASA resources to package them into the Polar story, and visualizations were created using Polar data to complement the NASA stock footage. Scientists donated their time to create and review scripts in order to make this a real team effort, working closely with the award winning audio-visual group at JHU/Applied Physics Laboratory. The team was excited to be invited to join NASA’s Sun-Earth Day 2005 E/PO program and the DVD will be distributed as part of the supporting educational packages.

Development in LIYaF of the method of polarized thermal neutron beam production by mirror reflection

International Nuclear Information System (INIS)

Borovikova, N.V.; Bulkin, A.P.; Gukasov, A.G.

1980-01-01

Main stages of development of polarizing neutron guide equipment in LIYaF of the USSR Academy of Sciences are described. To carry out experiments on solid-state physics constructed was a working mock-up of a polarizing neutron guide having 1570 mm length of a mirror channel. Successful application of polarizing mirrors to the working mock-up permitted to develop and fabricate five-meter polarizing neutron guide with output flux equal to 1.5x10 7 neutr/cm 2 xs. The following stage of development of polarizing neutron guides was the construction of four-meter neutron guide at the WWR-M reactor with output flux equal to the highest possible. Improvement of optical sections geometry made it possible to produce integral flux of 6.0x10 7 neutr/cm 2 xs in this neutron guide at 15 MW reactor power. The results obtained testify to prospects of the mirror method for polarization of thermal neutrons of a wave length lambda >= A. Neutron guides-polarizators permit to produce high fluxes of polarized thermal neutrons in the wide interval of wave length [ru

2013 POLAR MARINE SCIENCE GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR (MARCH 10-15, 2013 - FOUR POINTS SHERATON, VENTURA CA)

Energy Technology Data Exchange (ETDEWEB)

Bowman, Jeff S.

2012-12-15

As dynamic and thermodynamic processes associated with warming trends are impacting sea ice cover, oceanographic processes and atmosphere-ocean interactions across polar regions at unprecedented rate, observations and models show fundamentally different regional ecosystem responses. The non-linear and multi-directional biogeochemical responses of polar systems to atmospheric and oceanographic forcings emphasize the need to consider and reconcile observations and models at global and regional scales. The 9th GRC on Polar Marine Science will discuss recent developments and challenges emerging from contemporary and paleo-climate observations and models, encompassing regional and global scales. The GRC addresses the structure, functionalities and controls of polar marine systems through topics such as sea ice biogeochemistry, atmosphere-ocean forcings and interactions, food web trophodynamics, carbon and elemental cycling and fluxes, and a spectrum of ecological processes and interactions.

New York City International Polar Weekend at the American Museum of Natural History

Science.gov (United States)

Pfirman, S.; Turrin, M.; Macphee, R.

2008-12-01

The American Museum of Natural History, in partnership with Lamont-Doherty Earth Observatory and the Earth Institute of Columbia University and Barnard College, is featuring the International Polar Year through a New York City International Polar Weekend (NYC-IPW) in 2007, 2008 and 2009. The event showcases current polar research, polar environmental changes, history and culture during two days of family programs and activities, performances, and lectures. The goal of the NYC-IPW is to engage diverse audiences and enhance the public understanding of polar science, in particular IPY research, through close interactions with polar experts. Activities for the public include many disciplines, ranging from the physical sciences and cultural anthropology to music and art, and are presented in many forms, from lectures, panels and films to posters and play. Highlights of the NYC-IPW include: 1) A polar fair for youth and adults, showcasing scientists, artists, and educators who have worked at one or both poles and including many interactive exhibits featuring such topics as life in New York at the end of the last Ice Age, how Arctic sea ice is changing, and life on and under the ice. 2) Performances and presentations oriented towards children and families, including Inuit Throat Singers, Central Park Zoo Theater Group, and a northern lights show. 3) Lectures showcasing current IPY research and addressing such issues as the possible effects of climate change on the poles and the rest of the world, as well as polar poetry, art and film. 4) A partnership with New York City Urban Advantage program for Middle School students in the city to meet with scientists, teachers and students who had participated in polar research and travel. 5) Norwegian Consulate sponsorship of science presenters and Sami performers. The March 2007 event involved 85 presenters and volunteers from 22 institutions, and attracted ca. 3,500 visitors. Approximately 5,000 visitors attended the February 2008

Educational and Community Outreach Efforts by the United States Polar Rock Repository during the International Polar Year

Science.gov (United States)

Grunow, A.; Codispoti, J. E.

2010-12-01

The US Polar Rock Repository (USPRR) houses more than 19,000 rock samples from polar regions and these samples are made available to the scientific, educational and museum community. The USPRR has been active in promoting polar earth science to educational and community groups. During the past year, outreach efforts reached over 12,000 people. The USPRR outreach involve tours of the facility, school presentations, online laboratory exercises, working with the Columbus Metro Parks, teaching at summer camps, teaching special geology field assignments at the middle school level, as well as offering an ‘Antarctic Rock Box’ that contains representative samples of the three types of rocks, minerals, fossils, and books and activities about geology and Antarctica. The rock box activities have been designed and reviewed by educators and scientists to use as an educational supplement to the Earth Science course of study. The activities have been designed around the Academic Content Standards: k-12 Science manual published by the Ohio Department of Education to ensure that the activities and topics are focused on those mandated by the state of Ohio. The USPRR website has a Virtual Web Antarctic Expedition with many activities for Middle to High School age students. The students learn about how to plan a field season, safety techniques, how to make a remote field camp, identify what equipment is needed, learn about the different transportation choices, weather issues, understanding GPS, etc. Educational and community networks have been built in part, by directly contacting individuals at an institution and partnering with them on educational outreach. The institutions have been very interested in doing this because it brings scientists to the classroom and to the public. This type of outreach has also served as an opening for children to consider possible career choices in science that they may not have considered before. In many of the presentations, a female geologist

Exploring science teachers' perceptions of experimentation: implications for restructuring school practical work

Science.gov (United States)

Wei, Bing; Li, Xiaoxiao

2017-09-01

It is commonly recognised that practical work has a distinctive and central role in science teaching and learning. Although a large number of studies have addressed the definitions, typologies, and purposes of practical work, few have consulted practicing science teachers. This study explored science teachers' perceptions of experimentation for the purpose of restructuring school practical work in view of science practice. Qualitative interviews were conducted with 87 science teachers at the secondary school level. In the interviews, science teachers were asked to make a comparison between students' experiments and scientific experiments. Eight dimensions of experimentation were generated from the qualitative data analysis, and the distributions of these eight dimensions between the two types of experiments were compared and analysed. An ideal model of practical work was suggested for restructuring practical work at the secondary school level, and some issues related to the effective enactment of practical work were discussed.

Polarization-preserving holey fibers

DEFF Research Database (Denmark)

Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

2001-01-01

In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

The International Space Life Sciences Strategic Planning Working Group

Science.gov (United States)

White, Ronald J.; Rabin, Robert; Lujan, Barbara F.

1993-01-01

Throughout the 1980s, ESA and the space agencies of Canada, Germany, France, Japan, and the U.S. have pursued cooperative projects bilaterally and multilaterally to prepare for, and to respond to, opportunities in space life sciences research previously unapproachable in scale and sophistication. To cope effectively with likely future space research opportunities, broad, multilateral, coordinated strategic planning is required. Thus, life scientists from these agencies have allied to form the International Space Life Sciences Strategic Planning Working Group. This Group is formally organized under a charter that specifies the purpose of the Working Group as the development of an international strategic plan for the space life sciences, with periodic revisions as needed to keep the plan current. The plan will be policy-, not operations-oriented. The Working Group also may establish specific implementation teams to coordinate multilateral science policy in specific areas; such teams have been established for space station utilization, and for sharing of flight equipment.

Report on Workshop "Planning of Future Science in the Polar Ocean Study with Cooperation among Study Groups"

Directory of Open Access Journals (Sweden)

Mitsuo Fukuchi

2001-03-01

Full Text Available A workshop on "Planning of Future Science in the Polar Ocean Study with Cooperation among Study Groups" was held on November 1,2000,at the National Institute of Polar Research with 21 participants. In this workshop, a plan to charter a research vessel other than "Shirase" was introduced and a science plan using the chartered research vessel by 43rd Japanese Antarctic Research Expedition was discussed. This study is going to be conducted in the sea ice area around 140-150°E in mid-summer (February 2002, when biological production becomes active in the Antarctic Ocean. Oceanographic observations using "Shirase" are difficult to conduct in this season since she supports a wide range of summer operations around Syowa Station. The relationships between biological production and greenhouse effect gas production and the vertical transport of organic materials from the surface to deep ocean will be the focus of this study. At this stage, one deputy leader and three members of JARE, and 25-26 other scientists including graduate students and foreign scientists, will participate in the field observations using the chartered vessel. The members of JARE will conduct a project science program of the VI Phase of JARE, while the other participants will do part of the science program "Antarctic Ocean in Earth System". Since further observations for several years after the summer of 2002 will be required to understand the role of the Antarctic Ocean in global climate change, we have applied for a Grant-in-Aid for Scientific Research for the next project, which will start from 2001,to the Ministry of Education, Science, Sports and Culture of Japan. The proposal was discussed in detail in this workshop.

Many Paths toward Discovery: A Module for Teaching How Science Works

Science.gov (United States)

Price, Rebecca M.; Perez, Kathryn E.

2018-01-01

Improving students' understanding of how science works requires explicit instruction. Here, we test the efficacy of a module based on two previously published activities (the "Cube Puzzle" and the case study "Asteroids and Dinosaurs") that teach how science works to college science majors. Students also use the How Science…

A WIDER ROLE FOR TECHNICIANS IN SCIENCE PRACTICAL WORK WITH SCHOOL STUDENTS?

Directory of Open Access Journals (Sweden)

Timothy G. Harrison

2011-12-01

Full Text Available This paper reports the results of a study made on the impact of improved deployment of science technicians in the classroom could directly benefit students in practical science investigations. Science technicians are skilled individuals whose understanding of practical work is a valuable resource not being used of in support of students understanding of science. Aspects of practical work and technician support were scrutinised, through information attained from a post-16 student survey to improve understanding about this teaching tool, to establish if it was being used to its full potential within science lessons. Analysis was also made of students’ perceptions of school science. The main outcomes were that the majority of students enjoyed science practical work and felt that science could not be taught without it. Students studying science at pre-university level attained a greater understanding, through participating in relevant practical work, than students who had studied it at earlier, compulsory levels. Students reported that science technicians provide impact on student learning when contact time was the greatest.

Superconducting polarizing magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

Where civics meets science: building science for the public good through Civic Science.

Science.gov (United States)

Garlick, J A; Levine, P

2017-09-01

Public understanding of science and civic engagement on science issues that impact contemporary life matter more today than ever. From the Planned Parenthood controversy, to the Flint water crisis and the fluoridation debate, societal polarization about science issues has reached dramatic levels that present significant obstacles to public discussion and problem solving. This is happening, in part, because systems built to support science do not often reward open-minded thinking, inclusive dialogue, and moral responsibility regarding science issues. As a result, public faith in science continues to erode. This review explores how the field of Civic Science can impact public work on science issues by building new understanding of the practices, influences, and cultures of science. Civic Science is defined as a discipline that considers science practice and knowledge as resources for civic engagement, democratic action, and political change. This review considers how Civic Science informs the roles that key participants-scientists, public citizens and institutions of higher education-play in our national science dialogue. Civic Science aspires to teach civic capacities, to inform the responsibilities of scientists engaged in public science issues and to inspire an open-minded, inclusive dialogue where all voices are heard and shared commitments are acknowledged. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lunar polar rover science operations: Lessons learned and mission architecture implications derived from the Mojave Volatiles Prospector (MVP) terrestrial field campaign

Science.gov (United States)

Heldmann, Jennifer L.; Colaprete, Anthony; Elphic, Richard C.; Lim, Darlene; Deans, Matthew; Cook, Amanda; Roush, Ted; Skok, J. R.; Button, Nicole E.; Karunatillake, S.; Stoker, Carol; Marquez, Jessica J.; Shirley, Mark; Kobayashi, Linda; Lees, David; Bresina, John; Hunt, Rusty

2016-08-01

The Mojave Volatiles Prospector (MVP) project is a science-driven field program with the goal of producing critical knowledge for conducting robotic exploration of the Moon. Specifically, MVP focuses on studying a lunar mission analog to characterize the form and distribution of lunar volatiles. Although lunar volatiles are known to be present near the poles of the Moon, the three dimensional distribution and physical characteristics of lunar polar volatiles are largely unknown. A landed mission with the ability to traverse the lunar surface is thus required to characterize the spatial distribution of lunar polar volatiles. NASA's Resource Prospector (RP) mission is a lunar polar rover mission that will operate primarily in sunlit regions near a lunar pole with near-real time operations to characterize the vertical and horizontal distribution of volatiles. The MVP project was conducted as a field campaign relevant to the RP lunar mission to provide science, payload, and operational lessons learned to the development of a real-time, short-duration lunar polar volatiles prospecting mission. To achieve these goals, the MVP project conducted a simulated lunar rover mission to investigate the composition and distribution of surface and subsurface volatiles in a natural environment with an unknown volatile distribution within the Mojave Desert, improving our understanding of how to find, characterize, and access volatiles on the Moon.

UV Coatings, Polarization, and Coronagraphy

Science.gov (United States)

Bolcar, Matthew R.; Quijada, Manuel; West, Garrett; Balasubramanian, Bala; Krist, John; Martin, Stefan; Sabatke, Derek

2016-01-01

Presenation for the Large UltraViolet Optical Infrared (LUVOIR) and Habitable Exoplanet Imager (HabEx) Science and Technology Definition Teams (STDT) on technical considerations regarding ultraviolet coatings, polarization, and coronagraphy. The presentations review the state-of-the-art in ultraviolet coatings, how those coatings generate polarization aberrations, and recent study results from both the LUVOIR and HabEx teams.

Sciencey Girls: Discourses Supporting Working-Class Girls’ to Identify with Science

Directory of Open Access Journals (Sweden)

Spela Godec

2018-01-01

Full Text Available Women from working class and some ethnic minority backgrounds continue to be underrepresented in science, particularly in areas such as physical sciences and engineering. Many find it difficult to see science as something that is “for them”, which then has implications for their learning and participation in science. In this paper, I discuss findings from a U.K.-based qualitative study with 15 working-class girls, aged 11 to 13, from diverse ethnic backgrounds. Data were collected over the course of one academic year, through interviews and discussion groups with the girls and interviews with their science teachers, and analysed through a post-structural gender lens. The paper foregrounds five science-identifying girls, who negotiated their identification and engagement with science through the following discursive strategies: (i rendering gender invisible, (ii drawing attention to the presence of women in science, (iii reframing “science people” as caring and nurturing, and (iv cultural discourses of desirability of science. The findings contribute to the understanding of how working class girls—who are often “othered” and constructed as “unintelligible” within the dominant discursive regime of prototypical science—find identification with science possible. The paper discusses the affordances and challenges of each discursive strategy.

No More Polarization, Please!

OpenAIRE

Reinholt, Mia

2006-01-01

The organizational science literature on motivation has for long been polarized into two main positions; the organizational economic position focusing on extrinsic motivation and the organizational behavior position emphasizing intrinsic motivation. With the rise of the knowledge economy and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on mot...

United States Naval Academy Polar Science Program's Visual Arctic Observing Buoys; The IceGoat

Science.gov (United States)

Woods, J. E.; Clemente-Colon, P.; Nghiem, S. V.; Rigor, I.; Valentic, T. A.

2012-12-01

The U.S. Naval Academy Oceanography Department currently has a curriculum based Polar Science Program (USNA PSP). Within the PSP there is an Arctic Buoy Program (ABP) student research component that will include the design, build, testing and deployment of Arctic Buoys. Establishing an active, field-research program in Polar Science will greatly enhance Midshipman education and research, as well as introduce future Naval Officers to the Arctic environment. The Oceanography Department has engaged the USNA Ocean Engineering, Systems Engineering, Aerospace Engineering, and Computer Science Departments and developed a USNA Visual Arctic Observing Buoy, IceGoat1, which was designed, built, and deployed by midshipmen. The experience gained through Polar field studies and data derived from these buoys will be used to enhance course materials and laboratories and will also be used directly in Midshipman independent research projects. The USNA PSP successfully deployed IceGoat1 during the BROMEX 2012 field campaign out of Barrow, AK in March 2012. This buoy reports near real-time observation of Air Temperature, Sea Temperature, Atmospheric Pressure, Position and Images from 2 mounted webcams. The importance of this unique type of buoy being inserted into the U.S. Interagency Arctic Buoy Program and the International Arctic Buoy Programme (USIABP/IABP) array is cross validating satellite observations of sea ice cover in the Arctic with the buoys webcams. We also propose to develop multiple sensor packages for the IceGoat to include a more robust weather suite, and a passive acoustic hydrophone. Remote cameras on buoys have provided crucial qualitative information that complements the quantitative measurements of geophysical parameters. For example, the mechanical anemometers on the IABP Polar Arctic Weather Station at the North Pole Environmental Observatory (NPEO) have at times reported zero winds speeds, and inspection of the images from the NPEO cameras have showed

PoSSUM: Polar Suborbital Science in the Upper Mesosphere

Science.gov (United States)

Reimuller, J. D.; Fritts, D. C.; Thomas, G. E.; Taylor, M. J.; Mitchell, S.; Lehmacher, G. A.; Watchorn, S. R.; Baumgarten, G.; Plane, J. M.

2013-12-01

Project PoSSUM (www.projectpossum.org) is a suborbital research project leveraging imaging and remote sensing techniques from Reusable Suborbital Launch Vehicles (rSLVs) to gather critical climate data through use of the PoSSUM Observatory and the PoSSUM Aeronomy Laboratory. An acronym for Polar Suborbital Science in the Upper Mesosphere, PoSSUM grew from the opportunity created by the Noctilucent Cloud Imagery and Tomography Experiment, selected by the NASA Flight Opportunities Program as Experiment 46-S in March 2012. This experiment will employ an rSLV (e.g. the XCOR Lynx Mark II) launched from a high-latitude spaceport (e.g. Eielson AFB, Alaska or Kiruna, Sweden) during a week-long deployment scheduled for July 2015 to address critical questions concerning noctilucent clouds (NLCs) through flights that transition the cloud layer where the clouds will be under direct illumination from the sun. The 2015 Project PoSSUM NLC campaign will use the unique capability of rSLVs to address key under-answered questions pertaining to NLCs. Specifically, PoSSUM will answer: 1) What are the small-scale dynamics of NLCs and what does this tell us about the energy and momentum deposition from the lower atmosphere? 2) What is the seasonal variability of NLCs, mesospheric dynamics, and temperatures? 3) Are structures observed in the OH layer coupled with NLC structures? 4) How do NLCs nucleate? and 5) What is the geometry of NLC particles and how do they stratify? Instrumentation will include video and still-frame visible cameras (PoSSUMCam), infrared cameras, a mesospheric temperatures experiment, a depolarization LiDAR, a mesospheric density and temperatures experiment (MCAT), a mesospheric winds experiment, and a meteoric smoke detector (MASS). The instrument suite used on PoSSUM will mature through subsequent campaigns to develop an integrated, modular laboratory (the ';PoSSUM Observatory') that will provide repeatable, low cost, in-situ NLC and aeronomy observations as well

Practical work in secondary science a minds-on approach

CERN Document Server

Abrahams, Ian

2011-01-01

Practical work is an essential feature of secondary science education. However, questions have been raised by some science educators about its effectiveness as a teaching and learning strategy. Whilst such an approach is generally effective in getting pupils to do things with objects and materials, it is seen as relatively ineffective in developing their conceptual understanding of the associated scientific ideas and concepts. Ian Abrahams argues that this is because it is practiced as a 'hands-on' rather than 'minds-on' activity. Abrahams draws together theory and practice on effective teaching and learning in practical work in science - covering biology, chemistry and physics. He provides clear guidance to ensure that students are encouraged and supported to be 'minds-on' as well as a 'hands-on' so that they can make the most of this learning experience. An invaluable text for inspiringaspiring andexperienced secondary science professionals, especially for those on M-level secondary science PGCE programmes.

Sciencey Girls: Discourses Supporting Working-Class Girls’ to Identify with Science

OpenAIRE

Spela Godec

2018-01-01

Women from working class and some ethnic minority backgrounds continue to be underrepresented in science, particularly in areas such as physical sciences and engineering. Many find it difficult to see science as something that is “for them”, which then has implications for their learning and participation in science. In this paper, I discuss findings from a U.K.-based qualitative study with 15 working-class girls, aged 11 to 13, from diverse ethnic backgrounds. Data were collected over the co...

Implementing SPRINTT [Student Polar Research with IPY National(and International)Teacher Training] in 5th Grade Science

Science.gov (United States)

Glass, D. S.

2009-12-01

I implemented the new NSF-funded SPRINTT (Student Polar Research with IPY National (and International) Teacher Training) curriculum with a 5th grade science class. SPRINTT, developed at U.S. Satellite Laboratory, Inc., is a 5-8 week science program teaching 5th through 10th graders to investigate climate change using polar data. The program includes perspectives of both Western scientists and the indigenous Northern population. The course contains three phases: Phase 1 includes content, data interpretation, and hands-on experiments to study Frozen Water, Frozen Land, and Food; Phase 2 (optional) includes further content on specific polar topics; and Phase 3 is a scaffolded research investigation. Before the course, teachers were trained via live webinars. This curriculum capitalizes on children’s innate fascination with our planet’s final frontier and combines it with the politically and scientifically relevant topic of climate change. In 2009, I used SPRINTT with 23 heterogeneous fifth grade students at National Presbyterian School in Washington DC for an environmental science unit. Overall, it was a success. The students met most of the learning objectives and showed enthusiasm for the material. I share my experiences to help other educators and curriculum developers. The Phase 1 course includes earth science (glaciers, sea ice, weather and climate, greenhouse gases, seasons, and human impacts on environments), life science (needs of living things, food and energy transfer, adaptations, and ecosystems and biomes) and physical science (phases of matter). Tailoring the program, I focused on Phase 1, the most accessible material and content, while deemphasizing the more cumbersome Phase 3 online research project. Pre-assessments documented the students’ misconceptions and informed instruction. The investigations were appropriately educational and interesting. For example, students enjoyed looking at environmental factors and their impact on the people in the

Polar science, technology and information: Tenth anniversary conference of ACUNS (Association of Canadian Universities for Northern Studies), Ryerson Polytechnical Institute. La science, la technologie et l'information polaires: Dixieme conference anniversaire de l'AUCEN (Association Universitaire Canadienne d'Etudes Nordiques), Institut Polytechnique Ryerson

Energy Technology Data Exchange (ETDEWEB)

Adams, P.; Duerden, F. (eds.)

1988-01-01

A conference was held on the subject of polar science, technology and information, by the Association of Canadian Universities for Northern Studies (ACUNS). Papers were presented on varied subjects under the categories of technology and the north, polar science, information and the north, and ACUNS related activiities. Separate abstracts have been prepared for five papers from this conference.

How Science Works: Bringing the World of Science into the Classroom through Innovative Blended Media Approaches

Science.gov (United States)

Windale, Mark

2010-01-01

During the past three years, a team from the Centre for Science Education at Sheffield Hallam University, the University of Salford, the University of York, Glasshead and Teachers TV, has been working in collaboration to develop a series of blended media resources to support the teaching and learning of How Science Works (HSW) at Key Stages 3 and…

Three voices: women working in nuclear science and technology

International Nuclear Information System (INIS)

1999-01-01

Nuclear science and technology is a fascinating and growing work area for women. This short video portrays three professional women working within this field for the International Atomic Energy Agency

Reaching Across the Hemispheres with Science, Language, Arts and Technology

Science.gov (United States)

Sparrow, E. B.; Zicus, S.; Miller, A.; Baird, A.; Page, G.

2009-12-01

Twelve Alaskan elementary and middle school classes (grades 3-8) partnered with twelve Australian middle school classes, with each pair using web-based strategies to develop a collaborative ice-mystery fictional book incorporating authentic polar science. Three professional development workshops were held, bringing together educators and polar scientists in two IPY education outreach projects. The Alaska workshop provided an opportunity to bring together the North American teachers for lessons on arctic and antarctic science and an earth system science program Seasons and Biomes measurement protocols, as well as methods in collaborative e-writing and art in Ice e-Mysteries: Global Student Polar e-books project. Teachers worked with University of Alaska Fairbanks (UAF) and Australian scientists to become familiar with Arctic science research, science artifacts and resources available at UAF and the University of Alaska Museum of the North. In Australia, teachers received a similar project training through the Tasmania Museum and Art Gallery (TMAG) Center for Learning and Discovery on Antarctic science and the University of Tasmania. The long-distance collaboration was accomplished through Skype, emails and a TMAG supported website. A year later, Northern Hemisphere and Southern Hemisphere teacher partners met in a joint workshop in Tasmania, to share their experiences, do project assessments and propose activities for future collaborations. The Australian teachers received training on Seasons and Biomes scientific measurements and the Alaskan teachers, on Tasmanian vegetation, fauna and indigenous culture, Antarctic and Southern ocean studies. This innovative project produced twelve e-polar books written and illustrated by students; heightened scientific literacy about the polar regions and the earth system; increased awareness of the environment and indigenous cultures; stronger connections to the scientific community; and lasting friendships. It also resulted in

Educators Who Work in Science: The Narratives of Women Negotiating Careers in Academic Science

Science.gov (United States)

Tullos, Kimberly C.

2011-12-01

The purpose of this life story narrative study was to explore how women scientists develop views of self that enable them to negotiate careers within academic science. I framed the study using feminist standpoint theory as my theoretical foundation, and used possible selves theory as my conceptual framework. Eight women scientists working in academe described their journey regarding their views of self and career-related experiences. The study produced two key findings. First, seven themes emerged from my data analysis; these themes suggest that these women shared significant experiences in their quest to become scientists. Second, my feminist analysis of the participants' narratives indicates that distinct, but submerged gender-related tensions shaped their views of themselves as scientists and their science career decisions. These tensions include career choice and advancement constrained by family obligations, work environments that do not recognize or undervalue their skills and contributions to the profession, and perceived pressure to de-feminize their behavior to blend in to their work environment. Not unlike other women negotiating careers in academic science, they generally accepted their status as women to be an inherent part of their career pursuits and viewed workplace challenges as an opportunity to prove their competency. Seven of the eight women did not attribute their challenges to gender differences. However, the combined narratives revealed underlying conflicts between their views of self as women and as scientists resulting from their experiences in, and perceptions of, academic science environments. The study's principal theoretical contribution, from the feminist standpoint perspective, highlights the pervasive and unseen influence of gender dynamics. In this study, the participants developed views of themselves, not as scientists, but as "educators who work in science." This critical distinction enabled these participants, perhaps unknowingly

Invited article: polarization "down under": the polarized time-of-flight neutron reflectometer PLATYPUS.

Science.gov (United States)

Saerbeck, T; Klose, F; Le Brun, A P; Füzi, J; Brule, A; Nelson, A; Holt, S A; James, M

2012-08-01

This review presents the implementation and full characterization of the polarization equipment of the time-of-flight neutron reflectometer PLATYPUS at the Australian Nuclear Science and Technology Organisation (ANSTO). The functionality and efficiency of individual components are evaluated and found to maintain a high neutron beam polarization with a maximum of 99.3% through polarizing Fe/Si supermirrors. Neutron spin-flippers with efficiencies of 99.7% give full control over the incident and scattered neutron spin direction over the whole wavelength spectrum available in the instrument. The first scientific experiments illustrate data correction mechanisms for finite polarizations and reveal an extraordinarily high reproducibility for measuring magnetic thin film samples. The setup is now fully commissioned and available for users through the neutron beam proposal system of the Bragg Institute at ANSTO.

Work Values of Mortuary Science Students

Science.gov (United States)

Shaw, Thomas; Duys, David K.

2005-01-01

This article describes a descriptive study in an area significantly lacking validation. The focus of the study was the work values held by mortuary science students from 3 educational programs in the Midwest. The Values Scale (D. Nevill & D. Super, 1989) was used to measure the career-related values of a sample group of 116. According to…

"POLAR-PALOOZA" and "International POLAR-PALOOZA": Taking Researchers on the Road to Engage Public Audiences across America, and Around the World

Science.gov (United States)

Haines-Stiles, G.; Akuginow, E.

2010-12-01

POLAR-PALOOZA and its companion project, "International POLAR-PALOOZA" shared the same central premise: that polar researchers, speaking for themselves, could be powerful communicators about the science and mission of the 4th International Polar Year, and could successfully engage a wide variety of public audiences across America and around the world. Supported for the US tour by NSF and NASA, and internationally by NSF alone, the project enlisted more than forty American researchers, and 14 polar scientists from Brazil, China and Australia, to participate in events at science centers and natural history museums, universities, public libraries and schools, and also for targeted outreach to special audiences such as young female researchers in Oklahoma, or the Downtown Rotary in San Diego. Evaluations by two different ISE groups found similar results domestically and internationally. When supported by HD video clips and presenting informally in teams of 3, 4, 5 and sometimes even 6 researchers as part of a fast-paced "show," the scientists themselves were almost always rated as among the most important aspects of the program. Significant understandings about polar science and global climate change resulted, along with a positive impression of the research undertaken during IPY. This presentation at Fall AGU 2010 will present results from the Summative Evaluation of both projects, show representative video clips of the public presentations, share photographs of some of the most dramatically varied venues and candid behind-the-scenes action, and share "Lessons Learned" that can be broadly applied to the dissemination of Earth and space science research. These include: collaboration with partner institutions is never easy. (Duh.) Authentic props (such as ice cores, when not trashed by TSA) make a powerful impression on audiences, and give reality to remote places and complex science. And, most importantly, that since 85% of Americans have never met a scientist, that

Boundary-Work in Science Education: A Case Study of GM Food

Science.gov (United States)

Lin, Yin-Ling

2016-01-01

The term "boundary-work" is used to refer to the constant effort to draw and re-draw the boundary of science; it has long been portrayed as constructed by the stakeholders of science to demarcate science from non-science to establish the authority of science. Twenty-nine semi-structured interviews were carried out with students from one…

Implementation Science: Why It Matters for the Future of Social Work

Science.gov (United States)

Cabassa, Leopoldo J.

2016-01-01

Bridging the gap between research and practice is a critical frontier for the future of social work. Integrating implementation science into social work can advance our profession's effort to bring research and practice closer together. Implementation science examines the factors, processes, and strategies that influence the uptake, use, and…

Analyzing the Scientific Evolution of Social Work Using Science Mapping

Science.gov (United States)

Martínez, Ma Angeles; Cobo, Manuel Jesús; Herrera, Manuel; Herrera-Viedma, Enrique

2015-01-01

Objectives: This article reports the first science mapping analysis of the social work field, which shows its conceptual structure and scientific evolution. Methods: Science Mapping Analysis Software Tool, a bibliometric science mapping tool based on co-word analysis and h-index, is applied using a sample of 18,794 research articles published from…

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2000-01-01

The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li(p,n) 7 Be, and T(p,n) 3 He reactions. (authors)

Response: Social Work, Science, Social Impact--Crafting an Integrative Conversation

Science.gov (United States)

Nurius, Paula S.; Kemp, Susan P.

2012-01-01

Shifts in the ways that science is being undertaken and marshaled toward social change argue for a new kind of professional competence. Taking the view that the science of social work is centrally about the relationship of research to social impact, the authors extend Fong's focus on transdisciplinary and translational approaches to science,…

System for measuring the proton polarization in a polarized target

International Nuclear Information System (INIS)

Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1984-01-01

The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

A novel x-ray circularly polarized ranging method

Science.gov (United States)

Song, Shi-Bin; Xu, Lu-Ping; Zhang, Hua; Gao, Na; Shen, Yang-He

2015-05-01

Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. Projects supported by the National Natural Science Foundation of China (Grant Nos. 61172138 and 61401340), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2013JQ8040), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130203120004), the Open Research Fund of the Academy of Satellite Application, China (Grant No. 2014 CXJJ-DH 12), the Xi’an Science and Technology Plan, China (Grant No. CXY1350(4)), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 201413B, 201412B, and JB141303), and the Open Fund of Key Laboratory of Precision Navigation and Timing Technology, National Time Service Center, Chinese

Improving Group Work Practices in Teaching Life Sciences: Trialogical Learning

Science.gov (United States)

Tammeorg, Priit; Mykkänen, Anna; Rantamäki, Tomi; Lakkala, Minna; Muukkonen, Hanni

2017-08-01

Trialogical learning, a collaborative and iterative knowledge creation process using real-life artefacts or problems, familiarizes students with working life environments and aims to teach skills required in the professional world. We target one of the major limitation factors for optimal trialogical learning in university settings, inefficient group work. We propose a course design combining effective group working practices with trialogical learning principles in life sciences. We assess the usability of our design in (a) a case study on crop science education and (b) a questionnaire for university teachers in life science fields. Our approach was considered useful and supportive of the learning process by all the participants in the case study: the students, the stakeholders and the facilitator. Correspondingly, a group of university teachers expressed that the trialogical approach and the involvement of stakeholders could promote efficient learning. In our case in life sciences, we identified the key issues in facilitating effective group work to be the design of meaningful tasks and the allowance of sufficient time to take action based on formative feedback. Even though trialogical courses can be time consuming, the experience of applying knowledge in real-life cases justifies using the approach, particularly for students just about to enter their professional careers.

Sciencey Girls: Discourses Supporting Working-Class Girls to Identify with Science

Science.gov (United States)

Godec, Spela

2018-01-01

Women from working class and some ethnic minority backgrounds continue to be underrepresented in science, particularly in areas such as physical sciences and engineering. Many find it difficult to see science as something that is "for them", which then has implications for their learning and participation in science. In this paper, I…

Secondary school students' perceptions of working life skills in science-related careers

Science.gov (United States)

Salonen, Anssi; Hartikainen-Ahia, Anu; Hense, Jonathan; Scheersoi, Annette; Keinonen, Tuula

2017-07-01

School students demonstrate a lack of interest in choosing science studies and science-related careers. To better understand the underlying reasons, this study aims to examine secondary school students' perceptions of working life skills and how these perceptions relate to the skills of the twenty-first century. The participants in this study were 144 Finnish 7th graders (aged 13-14 years). Using a questionnaire and qualitative content analysis, we examined their perceptions of working life skills in 'careers in science' and 'careers with science'. Results reveal that although students have a great deal of knowledge about working life skills, it is often just stereotyped. Sector-specific knowledge and skills were highlighted in particular but skills related to society, organisation, time and higher order thinking, were often omitted. Results also indicate that students do not associate 'careers in science' with creativity, innovation, collaboration or technology and ICT skills. Conversely, according to the students, these careers demand more sector-specific knowledge and responsibility than 'careers with science'. We conclude that students need more wide-ranging information about scientific careers and the competencies demanded; such information can be acquired by e.g. interacting with professionals and their real working life problems.

In-line production of a bi-circular field for generation of helically polarized high-order harmonics

Energy Technology Data Exchange (ETDEWEB)

Kfir, Ofer, E-mail: ofertx@technion.ac.il, E-mail: oren@si.technion.ac.il; Bordo, Eliyahu; Ilan Haham, Gil; Lahav, Oren; Cohen, Oren, E-mail: ofertx@technion.ac.il, E-mail: oren@si.technion.ac.il [Solid State Institute and Physics Department, Technion, Haifa 32000 (Israel); Fleischer, Avner [Solid State Institute and Physics Department, Technion, Haifa 32000 (Israel); Department of Physics and Optical Engineering, Ort Braude College, Karmiel 21982 (Israel)

2016-05-23

The recent demonstration of bright circularly polarized high-order harmonics of a bi-circular pump field gave rise to new opportunities in ultrafast chiral science. In previous works, the required nontrivial bi-circular pump field was produced using a relatively complicated and sensitive Mach-Zehnder-like interferometer. We propose a compact and stable in-line apparatus for converting a quasi-monochromatic linearly polarized ultrashort driving laser field into a bi-circular field and employ it for generation of helically polarized high-harmonics. Furthermore, utilizing the apparatus for a spectroscopic spin-mixing measurement, we identify the photon spins of the bi-circular weak component field that are annihilated during the high harmonics process.

Graphics of polar figure; Graficado de figura polar

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R

1991-11-15

The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

Students' Views About Secondary School Science Lessons: The Role of Practical Work

Science.gov (United States)

Toplis, Rob

2012-06-01

This paper reports an interpretive study that sought students' views about the role that practical work plays in their school science lessons. Twenty-nine students aged between 13 and 16 years were selected from three secondary schools in England. Data were collected from initial lesson observations and in-depth interviews in order to explore students' views about practical work. The findings suggest that students have three main reasons why practical work is important in their school science lessons: for interest and activity, including social and personal features such as participation and autonomy; as an alternative to other forms of science teaching involving a pedagogy of transmission, and as a way of learning, including memorizing and recall. The findings are discussed in the context of a critical view of previous work on the role of practical work, work on attitudes to science and on the student voice. The paper concludes that practical work is seen to provide opportunities for students to engage with and influence their own learning but that learning with practical work remains a complex issue that needs further research and evaluation about its use, effectiveness and of the role of scientific inquiry as a component of practical activity.

Synthesis of focused beam with controllable arbitrary homogeneous polarization using engineered vectorial optical fields.

Science.gov (United States)

Rui, Guanghao; Chen, Jian; Wang, Xiaoyan; Gu, Bing; Cui, Yiping; Zhan, Qiwen

2016-10-17

The propagation and focusing properties of light beams continue to remain a research interest owning to their promising applications in physics, chemistry and biological sciences. One of the main challenges to these applications is the control of polarization distribution within the focal volume. In this work, we propose and experimentally demonstrate a method for generating a focused beam with arbitrary homogeneous polarization at any transverse plane. The required input field at the pupil plane of a high numerical aperture objective lens can be found analytically by solving an inverse problem with the Richard-Wolf vectorial diffraction method, and can be experimentally created with a vectorial optical field generator. Focused fields with various polarizations are successfully generated and verified using a Stokes parameter measurement to demonstrate the capability and versatility of proposed technique.

A Science of Social Work, and Social Work as an Integrative Scientific Discipline: Have We Gone Too Far, or Not Far Enough?

Science.gov (United States)

Brekke, John S.

2014-01-01

There are two purposes to this article. The first is to update the science of social work framework. The second is to use recent discussions on the nature of realist science and on social work science to propose a definition of social work as an integrative scientific discipline that complements its definition as a profession.

Libre: Freeing Polar Data in an Information Commons

Science.gov (United States)

Duerr, R. E.; Parsons, M. A.

2010-12-01

As noted in the session description “The polar regions are at the forefront of modern environmental change, currently experiencing the largest and fastest changes in climate and environment”. Wise use of resources, astute management of our environment, improved decision support, and effective international cooperation on natural resource and geopolitical issues require a deeper understanding of, and an ability to predict change and its impact. Understanding and knowledge are built on data and information, yet polar information is scattered, scarce, and sporadic. Rapid change demands rapid data access. We envision a system where investigators quickly expose their data to the world and share them, without restriction, through open protocols on the Internet. A single giant, central archive is not practical for all polar data held around the world. Instead, we seek a collaborative, virtual space, where scientific data and information could be shared ethically and with minimal constraints. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to generate greater scientific understanding, the International Council of Science leads the Polar Information Commons (PIC). The PIC, engendered by the International Polar Year (IPY) and work on the IPY data policy, serves as an open, virtual repository for vital scientific data and information. An international network of scientific and data management organizations concerned with the scientific quality, integrity, and stewardship of data is developing the PIC. The PIC utilizes the Science Commons Protocol for Implementing Open Access Data, including establishment of community norms to encourage appropriate contributions to and use of PIC content. Data descriptions (metadata) are not necessarily registered in formal repositories or catalogues. They may simply be exposed to search engines or broadcast through syndication services such as RSS or Atom. The data are labeled or branded as part

System of measurement of proton polarization in a polarized target

Energy Technology Data Exchange (ETDEWEB)

Karnaukov, I.M.; Chechetenko, V.F.; Lukhanin, A.A.; Telegin, Y.N.; Trotsenko, V.I.

1985-05-01

This paper describes a nuclear magnetic resonance spectrometer with high sensitivity. The signal of NMR absorption is recorded by a Q-meter with a series circuit and a circuit for compensation of the resonance characteristic of the measuring circuit. In order to ensure uniform sensitivity of the system to the state of polarization throughout the volume of the target and to enhance the S/N ration the measuring coil is made of a flat conductor. The polarization-measuring system works on-line with an M-6000 computer. The total error of measurement of the polarization of free protons in a target with allowance for the error due to local depolarization of free protons in a target with allowance for the error due to local depolarization of the working substance under irradiation with an intense photon beam is less than or equal to 6%.

Association of Polar Early Career Scientists: a model for experiential learning in professional development for students and early career researchers

Science.gov (United States)

Bradley, A. C.; Hindshaw, R. S.; Fugmann, G.; Mariash, H.

2016-12-01

The Association of Polar Early Career Scientists was established by early career researchers during the 2007-2008 International Polar Year as an organization for early career researchers in the polar and cryospheric sciences. APECS works to promote early career researchers through soft-skills training in both research and outreach activities, through advocating for including early career researchers in all levels of the scientific process and scientific management, and through supporting a world-wide network of researchers in varied fields. APECS is lead by early career researchers; this self-driven model has proved to be an effective means for developing the leadership, management, and communication skills that are essential in the sciences, and has shown to be sustainable even in a community where frequent turn-over is inherent to the members. Since its inception, APECS has reached over 5,500 members in more than 80 countries, and we have placed more than 50 early career researchers on working groups and steering committees with organizations around the world in the last two years alone. The close partnerships that APECS has with national and international organizations exposes members to both academic and alternative career paths, including those at the science-policy interface. This paper describes APECS's approach to experiential learning in professional development and the best practices identified over our nearly ten years as an organization.

Polarization phenomena in few-body systems

International Nuclear Information System (INIS)

Conzett, H.E.

1975-12-01

Recent polarization studies in N--N scattering at and below 50 MeV have provided specific and significant improvements in the phase-shift parameters. High energy investigations with both polarized proton beams and targets have shown unexpectedly large spin effects, and this provides a challenge for theoretical effort to explain these results. Experimental and theoretical work on the three-nucleon problem continues to yield new and interesting results, with the emphasis now shifting to polarization studies in the breakup reaction. On-going work on several-nucleon systems continues to provide polarization data for general analyses, nuclear structure information, or specific resonance effects. Finally, the basic interaction symmetries continue to have unique and important consequences for polarization observables. 17 figures

Freeing data through The Polar Information Commons

Science.gov (United States)

de Bruin, T.; Chen, R. S.; Parsons, M. A.; Carlson, D. J.; Cass, K.; Finney, K.; Wilbanks, J.; Jochum, K.

2010-12-01

The polar regions are changing rapidly with dramatic global effect. Wise management of resources, improved decision support, and effective international cooperation on resource and geopolitical issues require deeper understanding and better prediction of these changes. Unfortunately, polar data and information remain scattered, scarce, and sporadic. Inspired by the Antarctic Treaty of 1959 that established the Antarctic as a global commons to be used only for peaceful purposes and scientific research, we assert that data and information about the polar regions are themselves “public goods” that should be shared ethically and with minimal constraint. ICSU’s Committee on Data (CODATA) therefore started the Polar Information Commons (PIC) as an open, virtual repository for vital scientific data and information. The PIC provides a shared, community-based cyber-infrastructure fostering innovation, improving scientific efficiency, and encouraging participation in polar research, education, planning, and management. The PIC builds on the legacy of the International Polar Year (IPY), providing a long-term framework for access to and preservation of both existing and future data and information about the polar regions. Rapid change demands rapid data access. The PIC system enables scientists to quickly expose their data to the world and share them through open protocols on the Internet. A PIC digital label will alert users and data centers to new polar data and ensure that usage rights are clear. The PIC utilizes the Science Commons Protocol for Implementing Open Access Data, which promotes open data access through the public domain coupled with community norms of practice to ensure use of data in a fair and equitable manner. A set of PIC norms has been developed in consultation with key polar data organizations and other stakeholders. We welcome inputs from the broad science community as we further develop and refine the PIC approach and move ahead with

The Grand Challenges Discourse: Transforming Identity Work in Science and Science Policy.

Science.gov (United States)

Kaldewey, David

2018-01-01

This article analyzes the concept of "grand challenges" as part of a shift in how scientists and policymakers frame and communicate their respective agendas. The history of the grand challenges discourse helps to understand how identity work in science and science policy has been transformed in recent decades. Furthermore, the question is raised whether this discourse is only an indicator, or also a factor in this transformation. Building on conceptual history and historical semantics, the two parts of the article reconstruct two discursive shifts. First, the observation that in scientific communication references to "problems" are increasingly substituted by references to "challenges" indicates a broader cultural trend of how attitudes towards what is problematic have shifted in the last decades. Second, as the grand challenges discourse is rooted in the sphere of sports and competition, it introduces a specific new set of societal values and practices into the spheres of science and technology. The article concludes that this process can be characterized as the sportification of science, which contributes to self-mobilization and, ultimately, to self-optimization of the participating scientists, engineers, and policymakers.

Characterization of Partially Polarized Light Fields

CERN Document Server

Martínez-Herrero, Rosario; Piquero, Gemma

2009-01-01

Polarization involves the vectorial nature of light fields. In current applications of optical science, the electromagnetic description of light with its vector features has been shown to be essential: In practice, optical radiation also exhibits randomness and spatial non-uniformity of the polarization state. Moreover, propagation through photonic devices can alter the correlation properties of the light field, resulting in changes in polarization. All these vectorial properties have been gaining importance in recent years, and they are attracting increasing attention in the literature. This is the framework and the scope of the present book, which includes the authors’ own contributions to these issues.

Polarization for Background Reduction in EDXRF - The Technique That Would Not Work

International Nuclear Information System (INIS)

Ryon, R W

2002-01-01

As with all electromagnet radiation, polarization of x-rays is a general phenomenon. Such polarization has been known since the classic experiments of Barkla in 1906. The general implementation of polarization to x-ray analysis had to await the fixed geometry of energy-dispersive systems. The means of optimizing these systems is shown in this review paper. Improved detection limits are the result

Angular distribution coefficients for γ-ray polarization produced in polarized capture reactions

International Nuclear Information System (INIS)

Wulf, E.A.; Guillemette, J.; Weller, H.R.; Seyler, R.G.

1999-01-01

The previous publications have dealt with the angular momentum formalism of both linear and circularly polarized photons in (γ, x) reactions on both polarized and unpolarized targets, and the inverse (capture) reactions initiated by polarized beams. In the present work, utilizing the general formalism of Welton, the authors deal with the linear polarization of the γ-rays which are produced in capture reactions on unpolarized targets, including the possibility of having incident polarized spin 1/2 projectiles. These capture reactions are denoted by a(rvec x, rvec L)c, where rvec x is the incident polarized spin 1/2 projectile and rvec L represents the outgoing polarized γ-ray. They present here the formalism in a convenient form, display a sample table of coefficients, and illustrate its use by means of several examples. A FORTRAN code will be made available for generating similar coefficients for other reactions

Interdisciplinary technology assessment of service robots: the psychological/work science perspective.

Science.gov (United States)

Fischer, Martin

2012-12-01

The article sheds light on psychological and work science aspects of the design and utilization of service robots. An initial presentation of the characteristics of man-robot interaction is followed by a discussion of the principles of the division of functions between human beings and robots in service area work systems. The following aspects are to be considered: (1) the organisation of societal work (such as the different employment and professional profiles of service employees), (2) the work tasks to be performed by humans and robots (such as handling, monitoring or decision-making tasks), (3) the possibilities and the limitations of realizing such tasks by means of information technology (depending, for example, on the motoric capabilities, perception and cognition of the robot). Consideration of these three design perspectives gives rise to criteria of usability. Current debate focuses on the (work science) principles of man-machine communication, though in future these should be supplemented with robot-specific criteria such as "motoric capabilities" or "relationship quality." The article concludes by advocating the convergence and combination of work science criteria with ideas drawn from participative design approaches in the development and utilization of service robots.

Mathematics education a spectrum of work in mathematical sciences departments

CERN Document Server

Hsu, Pao-sheng; Pollatsek, Harriet

2016-01-01

Many in the mathematics community in the U.S. are involved in mathematics education in various capacities. This book highlights the breadth of the work in K-16 mathematics education done by members of US departments of mathematical sciences. It contains contributions by mathematicians and mathematics educators who do work in areas such as teacher education, quantitative literacy, informal education, writing and communication, social justice, outreach and mentoring, tactile learning, art and mathematics, ethnomathematics, scholarship of teaching and learning, and mathematics education research. Contributors describe their work, its impact, and how it is perceived and valued. In addition, there is a chapter, co-authored by two mathematicians who have become administrators, on the challenges of supporting, evaluating, and rewarding work in mathematics education in departments of mathematical sciences. This book is intended to inform the readership of the breadth of the work and to encourage discussion of its val...

Rich Support for Heterogeneous Polar Data in RAMADDA

Science.gov (United States)

McWhirter, J.; Crosby, C. J.; Griffith, P. C.; Khalsa, S.; Lazzara, M. A.; Weber, W. J.

2013-12-01

Difficult to navigate environments, tenuous logistics, strange forms, deeply rooted cultures - these are all experiences shared by Polar scientist in the field as well as the developers of the underlying data management systems back in the office. Among the key data management challenges that Polar investigations present are the heterogeneity and complexity of data that are generated. Polar regions are intensely studied across many science domains through a variety of techniques - satellite and aircraft remote sensing, in-situ observation networks, modeling, sociological investigations, and extensive PI-driven field project data collection. While many data management efforts focus on large homogeneous collections of data targeting specific science domains (e.g., satellite, GPS, modeling), multi-disciplinary efforts that focus on Polar data need to be able to address a wide range of data formats, science domains and user communities. There is growing use of the RAMADDA (Repository for Archiving, Managing and Accessing Diverse Data) system to manage and provide services for Polar data. RAMADDA is a freely available extensible data repository framework that supports a wide range of data types and services to allow the creation, management, discovery and use of data and metadata. The broad range of capabilities provided by RAMADDA and its extensibility makes it well-suited as an archive solution for Polar data. RAMADDA can run in a number of diverse contexts - as a centralized archive, at local institutions, and can even run on an investigator's laptop in the field, providing in-situ metadata and data management services. We are actively developing archives and support for a number of Polar initiatives: - NASA-Arctic Boreal Vulnerability Experiment (ABoVE): ABoVE is a long-term multi-instrument field campaign that will make use of a wide range of data. We have developed an extensive ontology of program, project and site metadata in RAMADDA, in support of the ABo

Shaping Social Work Science: What Should Quantitative Researchers Do?

Science.gov (United States)

Guo, Shenyang

2015-01-01

Based on a review of economists' debates on mathematical economics, this article discusses a key issue for shaping the science of social work--research methodology. The article describes three important tasks quantitative researchers need to fulfill in order to enhance the scientific rigor of social work research. First, to test theories using…

Revising laboratory work: sociological perspectives on the science classroom

Science.gov (United States)

Jobér, Anna

2017-09-01

This study uses sociological perspectives to analyse one of the core practices in science education: schoolchildren's and students' laboratory work. Applying an ethnographic approach to the laboratory work done by pupils at a Swedish compulsory school, data were generated through observations, field notes, interviews, and a questionnaire. The pupils, ages 14 and 15, were observed as they took a 5-week physics unit (specifically, mechanics). The analysis shows that the episodes of laboratory work could be filled with curiosity and exciting challenges; however, another picture emerged when sociological concepts and notions were applied to what is a very common way of working in the classroom. Laboratory work is characterised as a social activity that is expected to be organised as a group activity. This entails groups becoming, to some extent, `safe havens' for the pupils. On the other hand, this way of working in groups required pupils to subject to the groups and the peer effect, sometimes undermining their chances to learn and perform better. In addition, the practice of working in groups when doing laboratory work left some pupils and the teacher blaming themselves, even though the outcome of the learning situation was a result of a complex interplay of social processes. This article suggests a stronger emphasis on the contradictions and consequences of the science subjects, which are strongly influenced by their socio-historical legacy.

Making Science Work.

Science.gov (United States)

Thomas, Lewis

1981-01-01

Presents a viewpoint concerning the impact of recent scientific advances on society. Discusses biological discoveries, space exploration, computer technology, development of new astronomical theories, the behavioral sciences, and basic research. Challenges to keeping science current with technological advancement are also discussed. (DS)

Work function mediated by deposition of ultrathin polar FeO on Pt(111)

Energy Technology Data Exchange (ETDEWEB)

Lu, Shuangzan; Qin, Zhihui; Guo, Qinmin; Cao, Gengyu, E-mail: gycao@wipm.ac.cn

2017-01-15

Highlights: • Growth of FeO layers on Pt(111) is found to consecutively reduce the work function of the system. • The electrostatic compression effect and the structural relaxation make major contributions to the reductions. • Significant rectifying effect observed in the FeO layer is induced by band alignment shift as work function changing. - Abstract: Significant work function changes from bare Pt(111) surface to 1 monolayer and 2 monolayers of ultrathin iron oxide (FeO) films on it are investigated by means of scanning tunneling microscopy/spectroscopy (STM/STS). With FeO layer-by-layer growth, a continuous reduction of the work function along with the surface vacuum level (VL) shifting is observed. We found that the compression of the electron spill-out at the metal-oxide interface and the substantial reconstruction of 2 ML FeO film, respectively, make major contributions to the first and the second reductions of the work function. The rectifying effect in FeO films is also observed, which is attributed to the downward shift of band alignment imposed by the total change in surface dipole. Our work shows that the polar oxide films play an important role to adjust surface electronic structures for enhancing device functionality.

Work function mediated by deposition of ultrathin polar FeO on Pt(111)

International Nuclear Information System (INIS)

Lu, Shuangzan; Qin, Zhihui; Guo, Qinmin; Cao, Gengyu

2017-01-01

Highlights: • Growth of FeO layers on Pt(111) is found to consecutively reduce the work function of the system. • The electrostatic compression effect and the structural relaxation make major contributions to the reductions. • Significant rectifying effect observed in the FeO layer is induced by band alignment shift as work function changing. - Abstract: Significant work function changes from bare Pt(111) surface to 1 monolayer and 2 monolayers of ultrathin iron oxide (FeO) films on it are investigated by means of scanning tunneling microscopy/spectroscopy (STM/STS). With FeO layer-by-layer growth, a continuous reduction of the work function along with the surface vacuum level (VL) shifting is observed. We found that the compression of the electron spill-out at the metal-oxide interface and the substantial reconstruction of 2 ML FeO film, respectively, make major contributions to the first and the second reductions of the work function. The rectifying effect in FeO films is also observed, which is attributed to the downward shift of band alignment imposed by the total change in surface dipole. Our work shows that the polar oxide films play an important role to adjust surface electronic structures for enhancing device functionality.

The polarization response in InAs quantum dots: theoretical correlation between composition and electronic properties

International Nuclear Information System (INIS)

Usman, Muhammad; O’Reilly, Eoin P; Tasco, Vittorianna; Todaro, Maria Teresa; De Giorgi, Milena; Passaseo, Adriana; Klimeck, Gerhard

2012-01-01

III–V growth and surface conditions strongly influence the physical structure and resulting optical properties of self-assembled quantum dots (QDs). Beyond the design of a desired active optical wavelength, the polarization response of QDs is of particular interest for optical communications and quantum information science. Previous theoretical studies based on a pure InAs QD model failed to reproduce experimentally observed polarization properties. In this work, multi-million atom simulations are performed in an effort to understand the correlation between chemical composition and polarization properties of QDs. A systematic analysis of QD structural parameters leads us to propose a two-layer composition model, mimicking In segregation and In–Ga intermixing effects. This model, consistent with mostly accepted compositional findings, allows us to accurately fit the experimental PL spectra. The detailed study of QD morphology parameters presented here serves as a tool for using growth dynamics to engineer the strain field inside and around the QD structures, allowing tuning of the polarization response. (paper)

Carbon nanotube fiber terahertz polarizer

Energy Technology Data Exchange (ETDEWEB)

Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

2016-04-04

Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

The Work of Popper and Kuhn on the Nature of Science.

Science.gov (United States)

Donnelly, James

1979-01-01

Discusses the work of T. S. Kuhn and Sir Karl Popper. Current views on the nature of science and some current ideology of scientific education are also analyzed with regard to the views of science due to Kuhn and Popper. (HM)

Absolute Geostrophic Velocity Inverted from the Polar Science Center Hydrographic Climatology (PHC3.0) of the Arctic Ocean with the P-Vector Method (NCEI Accession 0156425)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset (called PHC-V) comprises 3D gridded climatological fields of absolute geostrophic velocity of the Arctic Ocean inverted from the Polar science center...

Wow, My Science Teacher Does Real Research! Engaging and Motivating Students Using Experiences from the Field

Science.gov (United States)

Scott, C.

2013-12-01

Students respond to personal connections. When K-12 science teachers are able to participate as field assistants on research projects, their students can benefit greatly from the stories, pictures, and video transmitted or brought back from the field. Teachers can translate and tailor their learning while in the field to the level of their students. Students are ';hooked' into science content by seeing their own teacher out there actually ';doing' science. The teacher is able to provide a direct content connection for the student, an avenue for understanding why ';learning this' is relevant and important. This presentation provides a case for why science teachers and researchers should collaborate as much as possible. The NSF funded PolarTREC program (Teachers and Researchers Exploring and Collaborating) is an excellent example of how to make this collaboration work. The presentation will also provide a look into how teachers can make an effective connection for their students between field science and classroom learning. Alaskan secondary science teacher Carol Scott spent a month at the Kevo Research Station in northern Finland in May/June 2013 as a PolarTREC teacher, and is translating this experience for students. She has also worked on an NSF Research Experience for Teachers grant in Prince William Sound, AK, and has successfully used this work to engage students in the classroom.

Revolutionizing Climate Science: Using Teachers as Communicators

Science.gov (United States)

Warburton, J.; Crowley, S.; Wood, J.

2012-12-01

PolarTREC (Teachers and Researchers Exploring and Collaborating) is a National Science Foundation (NSF) funded program in which K-12 teachers participate in hands-on field research experiences in the Polar Regions. Teachers are the dynamic conduits for communicating climate science. In the PolarTREC final report, researchers found that teachers were vital in refining the language of their science and have shaped the goals of the scientific project. Program data demonstrates that science in classrooms is better understood when teachers have a full-spectrum grasp of project intricacies from defining the project, to field data collection, encountering situations for creativity and critical thinking, as well as participating in data and project analysis. Teachers' translating the authentic scientific process is integral in communicating climate science to the broader public. Teachers playing a major role in polar science revolutionize the old paradigm of "in-school learning". Through daily online journaling and forums, social media communication, live webinars with public, and professional development events, these teachers are moving beyond classrooms to communicate with society. Through teachers, climate policy can be shaped for the future by having scientifically literate students as well as assessable science. New paradigms come as teachers attain proficient levels of scientific understanding paired with the expert abilities for communication with years of experience. PolarTREC teachers are a model for new interactions peer-to-peer learning and mentorship for young scientists. Our programmatic goal is to expand the opportunities for PolarTREC teachers to share their involvement in science with additional formal and informal educators. 'Teaching the teachers' will reach exponential audiences in media, policy, and classrooms. Modeling this program, we designed and conducted a teacher training on climate science in Denali National Park. Utilizing expert university

Broad-aperture polarized proton target with arbitrary orientation of polarization vector

International Nuclear Information System (INIS)

Belyaev, A.A.; Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporov, E.A.; Telegin, Yu.N.; Trotsenko, V.I.

1985-01-01

Polarized proton target with the Helmholtz broad-aperture superconducting magnetic system is described. Axial aperture α=95 deg, inter-coil access angle β=23 deg. The structure of the target allows various versions of the installation what make sure an arbitrary orientation of polarization vector. The 0.1 W cold output 3 He evaporation cryostat was used to obtain the work temperature 0.5 K allowing quick transformation to a 3 He- 4 He dilution refrigerator. Results of the study are given on the dynamical proton polarization in 1,2-propylenglycol with various stable Cr 5 complexes

Teleost polarization vision: how it might work and what it might be good for.

Science.gov (United States)

Kamermans, Maarten; Hawryshyn, Craig

2011-03-12

In this review, we will discuss the recent literature on fish polarization vision and we will present a model on how the retina processes polarization signals. The model is based on a general retinal-processing scheme and will be compared with the available electrophysiological data on polarization processing in the retina. The results of this model will help illustrate the functional significance of polarization vision for both feeding behaviour and navigation. First, we examine the linkage between structure and function in polarization vision in general.

1993 in review: Science policy developments

Science.gov (United States)

Jones, Richard M.; Mockler, Susan Bucci

Looking back over 1993, here are some of the major policy developments affecting the geophysical sciences community:JANUARY: John Gibbons confirmed as Office of Science and Technology Policy director and President Clinton's science advisor… Walter Massey resigns as National Science Foundation director… Hazel O'Leary becomes Department of Energy secretary … House Science, Space and Technology Committee is reorganized, reducing its six subcommittees to five… NSF's Division of Polar Programs elevated to the Office of Polar Programs, now a part of the Office of the Director… Bruce Babbitt confirmed as Secretary of the Interior.

A Si nanocube array polarizer

Science.gov (United States)

Chen, Linghua; Jiang, Yingjie; Xing, Li; Yao, Jun

2017-10-01

We have proposed a full dielectric (silicon) nanocube array polarizer based on a silicon dioxide substrate. Each polarization unit column includes a plurality of equal spaced polarization units. By optimizing the length, the width, the height of the polarization units and the center distance of adjacent polarization unit (x direction and y direction), an extinction ratio (ER) of higher than 25dB was obtained theoretically when the incident light wavelength is 1550nm. while for applications of most polarization optical elements, ER above 10dB is enough. With this condition, the polarizer we designed can work in a wide wavelength range from 1509.31nm to 1611.51nm. Compared with the previous polarizer, we have introduced a polarizer which is a full dielectric device, which solves the problems of low efficiency caused by Ohmic loss and weak coupling. Furthermore, compared with the existing optical polarizers, our polarizer has the advantages of thin thickness, small size, light weight, and low processing difficulty, which is in line with the future development trend of optical elements.

An organizing model for recent cognitive science work on the self.

Science.gov (United States)

Pageler, Ben

2016-10-01

An organizing model of 'the self' emerges from applying various kinds of brain injury to recent cognitive science and philosophical work on 'the self'. This model unifies various contents and mechanisms central to current notions of the self. The article then highlights several criteria and aspects of this notion of self. Qualities of the right type and level of psychological significance delineate 'the self' as an organizing concept useful for recent philosophical work and cognitive science research. Copyright © 2016 Elsevier Inc. All rights reserved.

Scientists and Science Education: Working at the Interface

Science.gov (United States)

DeVore, E. K.

2004-05-01

"Are we alone?" "Where did we come from?" "What is our future?" These questions lie at the juncture of astronomy and biology: astrobiology. It is intrinsically interdisciplinary in its study of the origin, evolution and future of life on Earth and beyond. The fundamental concepts of origin and evolution--of both living and non-living systems--are central to astrobiology, and provide powerful themes for unifying science teaching, learning, and appreciation in classrooms and laboratories, museums and science centers, and homes. Research scientists play a key role in communicating the nature of science and joy of scientific discovery with the public. Communicating the scientific discoveries with the public brings together diverse professionals: research scientists, graduate and undergraduate faculty, educators, journalists, media producers, web designers, publishers and others. Working with these science communicators, research scientists share their discoveries through teaching, popular articles, lectures, broadcast and print media, electronic publication, and developing materials for formal and informal education such as textbooks, museum exhibits and documentary television. There's lots of activity in science communication. Yet, the NSF and NASA have both identified science education as needing improvement. The quality of schools and the preparation of teachers receive national attention via "No Child Left Behind" requirements. The number of students headed toward careers in science, technology, engineering and mathematics (STEM) is not sufficient to meet national needs. How can the research community make a difference? What role can research scientists fulfill in improving STEM education? This talk will discuss the interface between research scientists and science educators to explore effective roles for scientists in science education partnerships. Astronomy and astrobiology education and outreach projects, materials, and programs will provide the context for

NOAA's Joint Polar Satellite System's (JPSS) Proving Ground and Risk Reduction (PGRR) Program - Bringing JPSS Science into Support of Key NOAA Missions!

Science.gov (United States)

Sjoberg, W.; McWilliams, G.

2017-12-01

This presentation will focus on the continuity of the NOAA Joint Polar Satellite System (JPSS) Program's Proving Ground and Risk Reduction (PGRR) and key activities of the PGRR Initiatives. The PGRR Program was established in 2012, following the launch of the Suomi National Polar Partnership (SNPP) satellite. The JPSS Program Office has used two PGRR Project Proposals to establish an effective approach to managing its science and algorithm teams in order to focus on key NOAA missions. The presenter will provide details of the Initiatives and the processes used by the initiatives that have proven so successful. Details of the new 2017 PGRR Call-for-Proposals and the status of project selections will be discussed.

Cosmic Microwave Background Polarization and Inflation

Science.gov (United States)

Chuss, David T.

2011-01-01

Measurements of the cosmic microwave background (CMB) offer a means to explore the universe at a very early epoch. Specifically, if the universe went through a brief period of exponential expansion called inflation as current data suggest, gravitational waves from this period would polarize the CMB in a specific pattern. At GSFC, we are currently working towards two experiments that work in concert to measure this polarization pattern in search of evidence for inflation. The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization at frequencies between 40 and 150 GHz from the Atacama Desert in Chile. The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne experiment that will make similar measurements at frequencies between 200 and 600 GHz.

CAREER Educational Outreach: Inquiry-based Atmospheric Science Lessons for K-12 students

Science.gov (United States)

Courville, Z.; Carbaugh, S.; Defrancis, G.; Donegan, R.; Brown, C.; Perovich, D. K.; Richter-Menge, J.

2011-12-01

Climate Comics is a collaborative outreach effort between the Montshire Museum of Science, in Norwich, VT, the Cold Regions Research and Engineering Laboratory (CRREL) research staff, and freelance artist and recent graduate of the Center for Cartoon Studies in White River Junction, VT, Sam Carbaugh. The project involves the cartoonist, the education staff from the museum, and researchers from CRREL creating a series of comic books with polar science and research themes, including sea ice monitoring, sea ice albedo, ice cores, extreme microbial activity, and stories and the process of fieldwork. The aim of the comic series is to provide meaningful science information in a comic-format that is both informative and fun, while highlighting current polar research work done at the lab. The education staff at the Montshire Museum develops and provides a series of hands-on, inquiry-based activity descriptions to complement each comic book, and CRREL researchers provide science background information and reiterative feedback about the comic books as they are being developed. Here, we present the motivation for using the comic-book medium to present polar research topics, the process involved in creating the comics, some unique features of the series, and the finished comic books themselves. Cartoon illustrating ways snow pack can be used to determine past climate information.

75 FR 57520 - NASA Advisory Council; Planetary Science Subcommittee; Supporting Research and Technology Working...

Science.gov (United States)

2010-09-21

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-112)] NASA Advisory Council; Planetary Science Subcommittee; Supporting Research and Technology Working Group; Meeting AGENCY: National... announces a meeting of the Supporting Research and Technology Working Group of the Planetary Science...

Spin-Polarization in Quasi-Magnetic Tunnel Junctions

Science.gov (United States)

Xie, Zheng-Wei; Li, Ling

2017-05-01

Spin polarization in ferromagnetic metal/insulator/spin-filter barrier/nonmagnetic metal, referred to as quasi-magnetic tunnel junctions, is studied within the free-electron model. Our results show that large positive or negative spin-polarization can be obtained at high bias in quasi-magnetic tunnel junctions, and within large bias variation regions, the degree of spin-polarization can be linearly tuned by bias. These linear variation regions of spin-polarization with bias are influenced by the barrier thicknesses, barrier heights and molecular fields in the spin-filter (SF) layer. Among them, the variations of thickness and heights of the insulating and SF barrier layers have influence on the value of spin-polarization and the linear variation regions of spin-polarization with bias. However, the variations of molecular field in the SF layer only have influence on the values of the spin-polarization and the influences on the linear variation regions of spin-polarization with bias are slight. Supported by the Key Natural Science Fund of Sichuan Province Education Department under Grant Nos 13ZA0149 and 16ZA0047, and the Construction Plan for Scientific Research Innovation Team of Universities in Sichuan Province under Grant No 12TD008.

Accelerator science and its civil and utility engineering work

International Nuclear Information System (INIS)

Yoshioka, Masakazu

2006-01-01

In large-scale accelerator projects such as TRISTAN and J-PARC, approximately half of the total project costs are spent on the civil and utility engineering work for the accelerator. In addition, the quality of civil and utility engineering has a large effect on the quality of the beam. With increasing scale of projects, there is growing specialization of the people in charge of the accelerator on the one hand, and the people in charge of civil and utility engineering on the other. Mutual understanding between the people in charge is therefore important in such cases. From the experience I have accumulated working on the facilities of many large projects, I have become keenly aware of the necessity for both accelerator-literate civil engineering specialists and civil engineering-literate accelerator researchers. A straight-forward method for satisfying this requirement is to systematize accelerator science as a science with civil and utility engineering for accelerators recognized as its sub-field. When new projects launched, the methodology of the natural sciences should be incorporated whereby past experience is fully utilized and then new technologies and knowledge are accumulated. (author)

Communicating Ocean Sciences College Courses: Science Faculty and Educators Working and Learning Together

Science.gov (United States)

Halversen, C.; Simms, E.; McDonnell, J. D.; Strang, C.

2011-12-01

scientists with experience using exemplary, research-based instructional materials that incorporate current learning theories and teaching strategies; 5) promote mutually beneficial collaborations between scientists and educators co-teaching the course; and 6) provide underrepresented K-12 students and visitors to informal science institutions with ocean sciences instruction and the opportunity to interact with the next generation of scientists. Evaluation findings over five years show that the course can be an effective mechanism to introduce scientists to education research and improve post-secondary science instruction. Students improved in their understanding of how people learn and how to effectively communicate. Science faculty reported that the course provided them with a heightened awareness and practical knowledge of learning theory and education research, and as a result, they felt they became more effective educators and communicators. This has implications for their work with future and fellow scientists, and the general public.

Communicating polar science to the general public: sharing the social media experience of @OceanSeaIceNPI

Science.gov (United States)

Rösel, Anja; Pavlov, Alexey K.; Granskog, Mats A.; Gerland, Sebastian; Meyer, Amelie; Hudson, Stephen R.; King, Jennifer; Itkin, Polona; Cohen, Lana; Dodd, Paul; de Steur, Laura

2016-04-01

The findings of climate science need to be communicated to the general public. Researchers are encouraged to do so by journalists, policy-makers and funding agencies and many of us want to become better science communicators. But how can we do this at the lab or small research group level without specifically allocated resources in terms of funds and communication officers? And how do we sustain communication on a regular basis and not just during the limited lifetime of a specific project? One of the solutions is to use the emerging platform of social media, which has become a powerful and inexpensive tool for communicating science to different target audiences. Many research institutions and individual researchers are already advanced users of social media, but small research groups and labs remain underrepresented. The group of oceanographers, sea ice and atmospheric scientists at the Norwegian Polar Institute (@OceanSeaIceNPI( will share our experiences developing and maintaining researcher-driven outreach for over a year through Instagram, Twitter and Facebook. We will present our solutions to some of the practical considerations such as identifying key target groups, defining the framework for sharing responsibilities and interactions within the research group, and choosing an up-to-date and appropriate social medium. By sharing this information, we aim to inspire and assist other research groups and labs in conducting their own effective science communication.

On feasibility of the experiments with a polarized deuteron beam and a polarized target at Charles University in relation with polarized fusion

International Nuclear Information System (INIS)

Plis, Yu.A.

2001-01-01

There is an interest in the problem of polarized fusion with the neutron-free d 3 He reaction. Up to now, the experimental data on the cross sections of two dd reactions, which produce neutrons at once or through secondary dt reaction, are absent for polarized deuterons. There is a relatively cheap way to carry out the experiments with polarized deuterons at the Charles University in Prague. A polarized deuteron beam with energy from 100 keV up to approximately 1 MeV may be produced on the Van de Graaff accelerator by the channeling of a deuteron beam through magnetized Ni single crystal foil, according M. Kaminsky [Phys. Rev. Lett. 23, 819 (1969)]. This method permits to produce a polarized deuteron beam of an energy ≤1 MeV with a current of ∼1 nA, vector polarization P 3 up to 2/3 and tensor polarization P 33 =0. It will be necessary to modify the existing polarized target at Charles University for work with a low energy deuteron beam [N. S. Borisov et al., Nucl. Instr. and Meth. A 345, 421 (1994)

NMR dispersion measurement of dynamic nuclear polarization

International Nuclear Information System (INIS)

Davies, K.; Cox, S.F.J.

1978-01-01

The feasibility of monitoring dynamic nuclear polarization from the NMR dispersive susceptibility is examined. Two prototype instruments are tested in a polarized proton target using organic target material. The more promising employs a tunnel diode oscillator, inside the target cavity, and should provide a precise polarization measurement working at a frequency far enough from the main resonance for the disturbance of the measured polarization to be negligible. Other existing methods for measuring target polarization are briefly reviewed. (author)

Polarized proton target with horizontal spin orientation

International Nuclear Information System (INIS)

Bunyatova, Eh.I.; Kiselev, Yu.F.; Kozlenko, N.G.

1988-01-01

Proton target, the polarization vector of which may be arbitrary oriented in horizontal plane relatively to the beam, is developed and tested. 70% value of polarization is obtained. 0.6 K temperature is acquired through 3 He pumping out continuous cycle. 1.2-propylene glycol - Cr(V) was used as working medium. Magnetic system is made in the form of Helmholtz sperconducting coils with working curren close to critical one. Target polarization is measured by NMR technique using original system of proton signal processing

Teleost polarization vision: how it might work and what it might be good for

NARCIS (Netherlands)

Kamermans, Maarten; Hawryshyn, Craig

2011-01-01

In this review, we will discuss the recent literature on fish polarization vision and we will present a model on how the retina processes polarization signals. The model is based on a general retinal-processing scheme and will be compared with the available electrophysiological data on polarization

The Community Earth System Model-Polar Climate Working Group and the status of CESM2.

Science.gov (United States)

Bailey, D. A.; Holland, M. M.; DuVivier, A. K.

2017-12-01

The Polar Climate Working Group (PCWG) is a consortium of scientists who are interested in modeling and understanding the climate in the Arctic and the Antarctic, and how polar climate processes interact with and influence climate at lower latitudes. Our members come from universities and laboratories, and our interests span all elements of polar climate, from the ocean depths to the top of the atmosphere. In addition to conducting scientific modeling experiments, we are charged with contributing to the development and maintenance of the state-of-the-art sea ice model component (CICE) used in the Community Earth System Model (CESM). A recent priority for the PCWG has been to come up with innovative ways to bring the observational and modeling communities together. This will allow for more robust validation of climate model simulations, the development and implementation of more physically-based model parameterizations, improved data assimilation capabilities, and the better use of models to design and implement field experiments. These have been informed by topical workshops and scientific visitors that we have hosted in these areas. These activities will be discussed and information on how the better integration of observations and models has influenced the new version of the CESM, which is due to be released in late 2017, will be provided. Additionally, we will address how enhanced interactions with the observational community will contribute to model developments and validation moving forward.

Work flows in life science

NARCIS (Netherlands)

Wassink, I.

2010-01-01

The introduction of computer science technology in the life science domain has resulted in a new life science discipline called bioinformatics. Bioinformaticians are biologists who know how to apply computer science technology to perform computer based experiments, also known as in-silico or dry lab

Polarized neutron spectrometer for inelastic experiments at J-PARC

Directory of Open Access Journals (Sweden)

Yokoo Tetsuya

2015-01-01

Full Text Available Construction of the newly developed polarization analysis neutron chopper spectrometer (POLANO commenced in the Japan Proton Accelerator Research Complex (J-PARC, Materials and Life Science Experimental Facility (MLF. The POLANO is a direct geometry chopper spectrometer with neutron polarization analysis capability. In the suite of inelastic spectrometers, six instruments are now in operation. POLANO will be the only spectrometer dedicated to polarization analysis experiments. The primary phase of the construction will be completed by 2014 with beam commissioning scheduled for 2015.

Preparing Science Teachers: Strong Emphasis on Science Content Course Work in a Master's Program in Education

Science.gov (United States)

Ajhar, Edward A.; Blackwell, E.; Quesada, D.

2010-05-01

In South Florida, science teacher preparation is often weak as a shortage of science teachers often prompts administrators to assign teachers to science classes just to cover the classroom needs. This results is poor preparation of students for college science course work, which, in turn, causes the next generation of science teachers to be even weaker than the first. This cycle must be broken in order to prepare better students in the sciences. At St. Thomas University in Miami Gardens, Florida, our School of Science has teamed with our Institute for Education to create a program to alleviate this problem: A Master of Science in Education with a Concentration in Earth/Space Science. The Master's program consists of 36 total credits. Half the curriculum consists of traditional educational foundation and instructional leadership courses while the other half is focused on Earth and Space Science content courses. The content area of 18 credits also provides a separate certificate program. Although traditional high school science education places a heavy emphasis on Earth Science, this program expands that emphasis to include the broader context of astronomy, astrophysics, astrobiology, planetary science, and the practice and philosophy of science. From this contextual basis the teacher is better prepared to educate and motivate middle and high school students in all areas of the physical sciences. Because hands-on experience is especially valuable to educators, our program uses materials and equipment including small optical telescopes (Galileoscopes), several 8-in and 14-in Celestron and Meade reflectors, and a Small Radio Telescope installed on site. (Partial funding provided by the US Department of Education through Minority Science and Engineering Improvement Program grant P120A050062.)

Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

Science.gov (United States)

Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

2017-06-01

In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

Polarized constituent quarks in NLO approximation

International Nuclear Information System (INIS)

Khorramian, Ali N.; Tehrani, S. Atashbar; Mirjalili, A.

2006-01-01

The valon representation provides a basis between hadrons and quarks, in terms of which the bound-state and scattering properties of hadrons can be united and described. We studied polarized valon distributions which have an important role in describing the spin dependence of parton distribution in leading and next-to-leading order approximation. Convolution integral in frame work of valon model as a useful tool, was used in polarized case. To obtain polarized parton distributions in a proton we need to polarized valon distribution in a proton and polarized parton distributions inside the valon. We employed Bernstein polynomial averages to get unknown parameters of polarized valon distributions by fitting to available experimental data

Coherent active polarization control without loss

Science.gov (United States)

Ye, Yuqian; Hay, Darrick; Shi, Zhimin

2017-11-01

We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2001-01-01

It is insufficient to know coordinates and momentum to describe a state of a neutron. It is necessary to define a spin orientation. As far as it is known from quantum mechanics, a half spin has a projection in the positive direction or in the negative direction. The probability of both projections in an unpolarized beam is equal. If a direction exists, in which the projection is more probably then beam is called polarized in this direction. It is essential to know polarization of neutrons for characteristics of a neutron source, which is emitting it. The question of polarization of fast neutrons came up in 50's. The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li (p,n) 7 Be, T(p,n) 3 He reactions. (authors)

Variety of Polarized Line Profiles in Interacting Supernovae

Science.gov (United States)

Hoffman, Jennifer L.; Huk, L. N.; Peters, C. L.

2013-01-01

The dense circumstellar material that creates strong emission lines in the spectra of interacting supernovae also gives rise to complex line polarization behavior. Viewed in polarized light, the emission line profiles of these supernovae encode information about the geometrical and optical characteristics of their surrounding circumstellar material (CSM) that is inaccessible by other observational techniques. To facilitate quantitative interpretation of these spectropolarimetric signatures, we have created a large grid of model polarized line profiles using a three-dimensional radiative transfer code that simulates polarization via electron and resonant/fluorescent line scattering. The simulated polarized lines take on an array of profile shapes that vary with viewing angle and CSM properties. We present the major results from the grid and investigate the dependence of polarized line profiles on CSM characteristics including temperature, optical depth, and geometry. These results will allow more straightforward interpretation of polarized line profiles in interacting supernovae than has previously been possible. This research is supported by the National Science Foundation through the AAG program and the XSEDE collaboration, and uses the resources of the Texas Advanced Computing Center.

Applying gene flow science to environmental policy needs: a boundary work perspective.

Science.gov (United States)

Ridley, Caroline E; Alexander, Laurie C

2016-08-01

One application of gene flow science is the policy arena. In this article, we describe two examples in which the topic of gene flow has entered into the U.S. national environmental policymaking process: regulation of genetically engineered crops and clarification of the jurisdictional scope of the Clean Water Act. We summarize both current scientific understanding and the legal context within which gene flow science has relevance. We also discuss the process by which scientific knowledge has been synthesized and communicated to decision-makers in these two contexts utilizing the concept of 'boundary work'. Boundary organizations, the work they engage in to bridge the worlds of science, policy, and practice, and the boundary objects they produce to translate scientific knowledge existed in both examples. However, the specific activities and attributes of the objects produced varied based on the needs of the decision-makers. We close with suggestions for how scientists can contribute to or engage in boundary work with policymakers.

PST 2009: XIII International Workshop on Polarized Sources Targets and Polarimetry

Science.gov (United States)

Lenisa, Paolo

2011-05-01

The workshops on polarized sources, targets, and polarimetry are held every two years. In 2009 the meeting took place in Ferrara, Italy, and was organized by the University of Ferrara and INFN. Sessions on Polarized Proton and Deuterium Sources, Polarized Electron Sources, Polarimetry, Polarized Solid Targets, and Polarized Internal Targets, highlighted topics, recent developments, and progress in the field. A session dedicated to Future Facilities provided an overview of a number of new activities in the spin-physics sector at facilities that are currently in the planning stage. Besides presenting a broad overview of polarized ion sources, electron sources, solid and gaseous targets, and their neighbouring fields, the workshop also addressed the application of polarized atoms in applied sciences and medicine that is becoming increasingly important.

16th International Workshop on Polarized Sources, Targets, and Polarimetry (PSTP 2015)

CERN Document Server

2015-01-01

The Workshop on Polarized Sources, Targets and Polarimetry has been a tradition for more than 20 years, moving between Europe, USA and Japan. The XVIth International Workshop on Polarized Sources, Targets and Polarimetry (PSTP 2015) will take place at the Ruhr-University of Bochum, Germany. The workshop addresses the physics and technological challenges related to polarized gas/solid targets, polarized electron/positron/ion/neutron sources, polarimetry and their applications. will be published in Proceedings of Science

Teaching science problem solving: an overview of experimental work

NARCIS (Netherlands)

Taconis, R.; Ferguson-Hessler, M.G.M.; Broekkamp, H.

2001-01-01

The traditional approach to teaching science problem solving is having the students work individually on a large number of problems. This approach has long been overtaken by research suggesting and testing other methods, which are expected to be more effective. To get an overview of the

Simulations to study the static polarization limit for RHIC lattice

Science.gov (United States)

Duan, Zhe; Qin, Qing

2016-01-01

A study of spin dynamics based on simulations with the Polymorphic Tracking Code (PTC) is reported, exploring the dependence of the static polarization limit on various beam parameters and lattice settings for a practical RHIC lattice. It is shown that the behavior of the static polarization limit is dominantly affected by the vertical motion, while the effect of beam-beam interaction is small. In addition, the “nonresonant beam polarization” observed and studied in the lattice-independent model is also observed in this lattice-dependent model. Therefore, this simulation study gives insights of polarization evolution at fixed beam energies, that are not available in simple spin tracking. Supported by the U.S. Department of Energy (DE-AC02-98CH10886), Hundred-Talent Program (Chinese Academy of Sciences), and National Natural Science Foundation of China (11105164)

Polarized ³He Neutron Spin Filters

Energy Technology Data Exchange (ETDEWEB)

Sno, William Michael [Indiana Univ., Bloomington, IN (United States)

2016-01-12

The goal of this grant to Indiana University and subcontractors at Hamilton College and Wisconsin and the associated Interagency Agreement with NIST was to extend the technique of polarized neutron scattering by the development and application of polarized ³He-based neutron spin filters. This effort was blessed with long-term support from the DOE Office of Science, which started in 2003 and continued until the end of a final no-cost extension of the last 3-year period of support in 2013. The steady support from the DOE Office of Science for this long-term development project was essential to its eventual success. Further ³He neutron spin filter development is now sited at NIST and ORNL.

Coherent active polarization control without loss

Directory of Open Access Journals (Sweden)

Yuqian Ye

2017-11-01

Full Text Available We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

Optimising neutron polarizers--measuring the flipping ratio and related quantities

CERN Document Server

Goossens, D J

2002-01-01

The continuing development of gaseous spin polarized sup 3 He transmission filters for use as neutron polarizers makes the choice of optimum thickness for these filters an important consideration. The 'quality factors' derived for the optimisation of transmission filters for particular measurements are general to all neutron polarizers. In this work optimisation conditions for neutron polarizers are derived and discussed for the family of studies related to measuring the flipping ratio from samples. The application of the optimisation conditions to sup 3 He transmission filters and other types of neutron polarizers is discussed. Absolute comparisons are made between the effectiveness of different types of polarizers for this sort of work.

Statistics of polarization speckle: theory versus experiment

DEFF Research Database (Denmark)

Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo

2010-01-01

In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

Polish polar research (outline

Directory of Open Access Journals (Sweden)

Krzysztof Ludwik Birkenmajer

2017-12-01

Full Text Available The article describes Polish research and discoveries in the Arctic and the Antarctic since the 19th century. The author is a geologist and since 1956 has been engaged in scientific field research on Spitsbergen, Greenland and Antarctica (23 expeditions. For many years chairman of the Committee on Polar Research of the Polish Academy of Sciences, he is now its Honorary Chairman.

Ultra-broadband and high-efficiency polarization conversion metasurface with multiple plasmon resonance modes

Science.gov (United States)

Dong, Guo-Xiang; Shi, Hong-Yu; Xia, Song; Li, Wei; Zhang, An-Xue; Xu, Zhuo; Wei, Xiao-Yong

2016-08-01

In this paper, we present a novel metasurface design that achieves a high-efficiency ultra-broadband cross polarization conversion. The metasurface is composed of an array of unit resonators, each of which combines an H-shaped structure and two rectangular metallic patches. Different plasmon resonance modes are excited in unit resonators and allow the polarization states to be manipulated. The bandwidth of the cross polarization converter is 82% of the central frequency, covering the range from 15.7 GHz to 37.5 GHz. The conversion efficiency of the innovative new design is higher than 90%. At 14.43 GHz and 40.95 GHz, the linearly polarized incident wave is converted into a circularly polarized wave. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471292, 61331005, 61471388, 51277012, 41404095, and 61501365), the 111 Project, China (Grant No. B14040), the National Basic Research Program of China (Grant No. 2015CB654602), and the China Postdoctoral Science Foundation ( Grant No. 2015M580849).

Python data science handbook essential tools for working with data

CERN Document Server

VanderPlas, Jake

2016-01-01

For many researchers, Python is a first-class tool mainly because of its libraries for storing, manipulating, and gaining insight from data. Several resources exist for individual pieces of this data science stack, but only with the Python Data Science Handbook do you get them all—IPython, NumPy, Pandas, Matplotlib, Scikit-Learn, and other related tools. Working scientists and data crunchers familiar with reading and writing Python code will find this comprehensive desk reference ideal for tackling day-to-day issues.

Ultra-wideband reflective polarization converter based on anisotropic metasurface

Science.gov (United States)

Wu, Jia-Liang; Lin, Bao-Qin; Da, Xin-Yu

2016-08-01

In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x- or y-polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471387, 61271250, and 61571460).

IPY 2007-2008 and Scientists, Science Organisations, and the Public

Science.gov (United States)

Carlson, D. J.

2006-12-01

An initial burst of enthusiasm resulted in more than 1000 expressions of interest and nearly 500 internationally coordinated proposals for polar research during IPY. An international committee has endorsed more than 200 of these proposals, and most other proposals and nearly all expressions of interest have found ways to join the endorsed programme. Ten nations have announced new IPY science funding totalling in excess of 300M USD for the two years of operations; several nations will make announcements soon. Most on-going funding for polar research, coming from at least 30 nations, approximately 1.6B USD over two years, will also support IPY activities. What should the thousands of scientists hoping to participate expect, personally and collectively? What should the overall science entity expect, during and after IPY? And, finally, what should the public expect, after much attention and the expenditure of 2B USD, not to mention the on-going and future costs of ice breakers and ice-monitoring satellites and polar bases? Many IPY scientists will initially experience disappointment. Funding, even with IPY infusions, will fall short of need, and initial proposal success rates will stay below 50% in almost every nation, far below in some nations. In many nations, however, a catch-up effect will occur, leading to more funds in 2008 or 2009 than in 2006 and 2007. A step-up effect will also occur, leading to increased on-going funds for polar research, although perhaps in smaller steps and in fewer countries than we might hope. Scientists should expect increased public attention to their work and increased demand for their cooperation and contribution to international data management and to public outreach. Individually and collectively, IPY scientists have the opportunity to interact with an amazing array of fellow scientists, exchanging experience and enthusiasm on topics from gravitational variations to genomic sequences to Gwich'in cultures. Science as an entity will

Ultra-wideband circular-polarization converter with micro-split Jerusalem-cross metasurfaces

Science.gov (United States)

Gao, Xi; Yu, Xing-Yang; Cao, Wei-Ping; Jiang, Yan-Nan; Yu, Xin-Hua

2016-12-01

An ultrathin micro-split Jerusalem-cross metasurface is proposed in this paper, which can efficiently convert the linear polarization of electromagnetic (EM) wave into the circular polarization in ultra-wideband. By symmetrically employing two micro-splits on the horizontal arm (in the x direction) of the Jerusalem-cross structure, the bandwidth of the proposed device is significantly extended. Both simulated and experimental results show that the proposed metasurface is able to convert linearly polarized waves into circularly polarized waves in a frequency range from 12.4 GHz to 21 GHz, with an axis ratio better than 1 dB. The simulated results also show that such a broadband and high-performance are maintained over a wide range of incident angle. The presented polarization converter can be used in a number of areas, such as spectroscopy and wireless communications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61461016 and 61661012), the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant Nos. 2014GXNSFAA118366, 2014GXNSFAA118283, and 2015jjBB7002), and the Innovation Project of Graduate Education of Guilin University of Electronic Technology, China (Grant No. 2016YJCX82).

Minutes of TOPEX/POSEIDON Science Working Team Meeting and Ocean Tides Workshop

Science.gov (United States)

Fu, Lee-Lueng (Editor)

1995-01-01

This third TOPEX/POSEIDON Science Working Team meeting was held on December 4, 1994 to review progress in defining ocean tide models, precision Earth orbits, and various science algorithms. A related workshop on ocean tides convened to select the best models to be used by scientists in the Geophysical Data Records.

Graphics of polar figure

International Nuclear Information System (INIS)

Macias B, L.R.

1991-11-01

The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

Building sustained partnerships in Greenland through shared science

Science.gov (United States)

Culler, L. E.; Albert, M. R.; Ayres, M. P.; Grenoble, L. A.; Virginia, R. A.

2013-12-01

Greenland is a hotspot for polar environmental change research due to rapidly changing physical and ecological conditions. Hundreds of international scientists visit the island each year to carry out research on diverse topics ranging from atmospheric chemistry to ice sheet dynamics to Arctic ecology. Despite the strong links between scientific, social, and political issues of rapid environmental change in Greenland, communication with residents of Greenland is often neglected by researchers. Reasons include language barriers, difficulties identifying pathways for communication, balancing research and outreach with limited resources, and limited social and cultural knowledge about Greenland by scientists. Dartmouth College has a legacy of work in the Polar Regions. In recent years, a National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) in Polar Environmental Change funded training for 25 Ph.D. students in the Ecology, Earth Science, and Engineering graduate programs at Dartmouth. An overarching goal of this program is science communication between these disciplines and to diverse audiences, including communicating about rapid environmental change with students, residents, and the government of Greenland. Students and faculty in IGERT have been involved in the process of engaging with and sustaining partnerships in Greenland that support shared cultural and educational experiences. We have done this in three ways. First, a key component of our program has been hosting students from Ilisimatusarfik (the University of Greenland). Since 2009, five Greenlandic students have come to Dartmouth and formed personal connections with Dartmouth students while introducing their Greenlandic culture and language (Kalaallisut). Second, we have used our resources to extend our visits to Greenland, which has allowed time to engage with the community in several ways, including sharing our science via oral and poster presentations at Katuaq

Accelerating and storing polarized hadron beams

International Nuclear Information System (INIS)

Teng, L.C.

1990-10-01

Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical side the recent understanding and confirmation of the actions of partial and multiple Siberian snakes made it possible to contemplate accelerating and storing polarized hadron beams to multi-TeV energies. In this paper, we will examine the equipment, the operation and the procedure required to obtain colliding beams of polarized protons at TeV energies

Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

DEFF Research Database (Denmark)

Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.

2015-01-01

Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind...... of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

First-principles calculation of the polarization-dependent force driving the Eg mode in bismuth under optical excitation.

Science.gov (United States)

Murray, Eamonn; Fahy, Stephen

2014-03-01

Using first principles electronic structure methods, we calculate the induced force on the Eg (zone centre transverse optical) phonon mode in bismuth immediately after absorption of polarized light. When radiation with polarization perpendicular to the c-axis is absorbed in bismuth, the distribution of excited electrons and holes breaks the three-fold rotational symmetry and leads to a net force on the atoms in the direction perpendicular to the axis. We calculate the initial excited electronic distribution as a function of photon energy and polarization and find the resulting transverse and longitudinal forces experienced by the atoms. Using the measured, temperature-dependent rate of decay of the transverse force[2], we predict the approximate amplitude of induced atomic motion in the Eg mode as a function of temperature and optical fluence. This work is supported by Science Foundation Ireland and a Marie Curie International Incoming Fellowship.

Framing Education for a Science of Social Work: Missions, Curriculum, and Doctoral Training

Science.gov (United States)

Fong, Rowena

2012-01-01

Social work education has historically been grounded in professional practice but recent discussions have urged a reconsideration of social work as a science. Social work is progressively doing more intervention work, service systems research, implementation research, and translational research which are elevating research standards to new levels…

Secondary School Students' Perceptions of Working Life Skills in Science-Related Careers

Science.gov (United States)

Salonen, Anssi; Hartikainen-Ahia, Anu; Hense, Jonathan; Scheersoi, Annette; Keinonen, Tuula

2017-01-01

School students demonstrate a lack of interest in choosing science studies and science-related careers. To better understand the underlying reasons, this study aims to examine secondary school students' perceptions of working life skills and how these perceptions relate to the skills of the twenty-first century. The participants in this study were…

Undergraduate honors students' images of science: Nature of scientific work and scientific knowledge

Science.gov (United States)

Wallace, Michael L.

This exploratory study assessed the influence of an implicit, inquiry-oriented nature of science (NOS) instructional approach undertaken in an interdisciplinary college science course on undergraduate honor students' (UHS) understanding of the aspects of NOS for scientific work and scientific knowledge. In this study, the nature of scientific work concentrated upon the delineation of science from pseudoscience and the value scientists place on reproducibility. The nature of scientific knowledge concentrated upon how UHS view scientific theories and how they believe scientists utilize scientific theories in their research. The 39 UHS who participated in the study were non-science majors enrolled in a Honors College sponsored interdisciplinary science course where the instructors took an implicit NOS instructional approach. An open-ended assessment instrument, the UFO Scenario, was designed for the course and used to assess UHS' images of science at the beginning and end of the semester. The mixed-design study employed both qualitative and quantitative techniques to analyze the open-ended responses. The qualitative techniques of open and axial coding were utilized to find recurring themes within UHS' responses. McNemar's chi-square test for two dependent samples was used to identify whether any statistically significant changes occurred within responses from the beginning to the end of the semester. At the start of the study, the majority of UHS held mixed NOS views, but were able to accurately define what a scientific theory is and explicate how scientists utilize theories within scientific research. Postinstruction assessment indicated that UHS did not make significant gains in their understanding of the nature of scientific work or scientific knowledge and their overall images of science remained static. The results of the present study found implicit NOS instruction even with an extensive inquiry-oriented component was an ineffective approach for modifying UHS

Generalized Expression for Polarization Density

International Nuclear Information System (INIS)

Wang, Lu; Hahm, T.S.

2009-01-01

A general polarization density which consists of classical and neoclassical parts is systematically derived via modern gyrokinetics and bounce-kinetics by employing a phase-space Lagrangian Lie-transform perturbation method. The origins of polarization density are further elucidated. Extending the work on neoclassical polarization for long wavelength compared to ion banana width [M. N. Rosenbluth and F. L. Hinton, Phys. Rev. Lett. 80, 724 (1998)], an analytical formula for the generalized neoclassical polarization including both finite-banana-width (FBW) and finite-Larmor-radius (FLR) effects for arbitrary radial wavelength in comparison to banana width and gyroradius is derived. In additional to the contribution from trapped particles, the contribution of passing particles to the neoclassical polarization is also explicitly calculated. Our analytic expression agrees very well with the previous numerical results for a wide range of radial wavelength.

Polarized proton and deuteron targets for the usage in intensive proton beams

International Nuclear Information System (INIS)

Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporo, E.A.; Telegin, Yu.N.

1982-01-01

Polarized proton and deuteron targets are developed and tested for conducting investigations in intense photon beams. A flowsheet of polarization targets which includes: working agent of the target, superconducting magnet, cryostat of 3 He evaporation with 3 He pumping and recirculation systems, SHF system of 4 mm range for polarization pumping, measuring system of target polarization protons is presented. Working agent of the targets includes frozen balls with 1.5 mm diameter. Ethylene-glucol and 1.2-propylene-glycol were used as a working substance for proton targets. Completely deuterated ethylene-glycol was used for the deuteron target. Vertical magnetic field with 2.7 T intensity is produced by a superconducting magnetic system. Polarization pumping is exercised at 75 GHz frequency. Q-meter of direct current is used for determination of polarization. Working temperature of the cryostat is approximately 0.5 K. The lock device permits to exercise replacement of the target working agent during 30 minutes

Summary of the XIII International Workshop on Polarized Sources, Targets and Polarimetry

Science.gov (United States)

Rathmann, F.

2011-01-01

The workshops on polarized sources, targets, and polarimetry are held every two years. The present meeting took place in Ferrara, Italy, and was organized by the University of Ferrara. Sessions on Polarized Proton and Deuterium Sources, Polarized Electron Sources, Polarimetry, Polarized Solid Targets, and Polarized Internal Targets, highlighted topics, recent developments, and progress in the field. A session decicated to Future Facilities provided an overview of a number of new activities in the spin-physics sector at facilities that are currently in the planning stage. Besides presenting a broad overview of polarized ion sources, electron sources, solid and gaseous targets, and their neighboring fields, the workshop also addressed the application of polarized atoms in applied sciences and medicine that is becoming increasingly important.

Fiscal 1982 plans of works in National Institute of Radiological Sciences, Science and Technology Agency

International Nuclear Information System (INIS)

1982-01-01

National Institute of Radiological Sciences, since its establishment in 1957, has engaged in the research and other works on the radiation injuries in human bodies, the medical utilization of radiation and the training and education of personnel in the field. The plans of works in fiscal 1982 in the NIRS are described. As special research works, there are the estimation of the degree of danger due to low level radiation for human bodies, environmental radiation exposure due to nuclear facilities, etc., the medical utilization of particle accelerators, and the biological effects of tritium in nuclear fusion reactor development. Ordinary research works include physics, chemistry, genetics, pharmacy, clinical research, etc. In other areas of activities are radiation risk evaluation, radioactivity investigation, technological aid, personnel education and training, and medical work. (Mori, K.)

Rómulo de Carvalho's Work on the Popularization of Science During Salazarism

Science.gov (United States)

Galamba, Arthur

2013-10-01

This article provides an account of Rómulo de Carvalho's most prominent works on the popularization of science during the Salazarist regime in Portugal. Carvalho has been praised for his `unique' writing style, for his uncommon ability to communicate scientific knowledge with clarity to a wide audience: he wrote to teachers, to secondary students, to the layman and even to the rural peasantry. Most of his books and articles on popularization explored the History and Philosophy of Science, and it has been claimed that he influenced many youngsters to pursue scientific careers. Given the repressive political context imposed by Salazarism, it is argued that Carvalho's work on the popularization of science had a humanist and libertarian connotation. However, intriguingly, different from some of his contemporaries who also promoted humanistic education for all, Carvalho was never targeted by the Dictatorship. The article seeks to shed light on this matter. It points out the educational reach of Carvalho's writings and suggests that popularization of science in repressive regimes is not necessarily a problematic issue as long as it does not threat the status quo.

Wien filter for a polarized ions source

International Nuclear Information System (INIS)

Perez A, P.I.

1977-01-01

In order to carry out investigation works about nuclear structure, the Nuclear Center of Mexico has an accelerator Tandem Van de Graff of 12 Mv. Now in this center there is a polarized ions source, in a setting phase, totally constructed in the workshop of the accelerator. This source, supplies an ion beam with a polarization whose propagation direction is not the adequate one for the dispersion and reaction processes wanted to be realized. A filter Wien was used to obtain the correct direction of the polarization vector. The purpose of this work is the study of the filter necessary conditions in order to reach the desirable objective. In the first part some generalities are given about: polarization phenomena, polarized ions source and description of the performance of the Wien filter. In the second part, the problem of the passage of a polarized beam through the filter is tried and solved. Finally, the design and construction of the filter is presented together with the results of the experimentation with the object to justify the suppositions which were taken into consideration in the solution of the filter problem. (author)

IceCube Polar Virtual Reality exhibit: immersive learning for learners of all ages

Science.gov (United States)

Madsen, J.; Bravo Gallart, S.; Chase, A.; Dougherty, P.; Gagnon, D.; Pronto, K.; Rush, M.; Tredinnick, R.

2017-12-01

The IceCube Polar Virtual Reality project is an innovative, interactive exhibit that explains the operation and science of a flagship experiment in polar research, the IceCube Neutrino Observatory. The exhibit allows users to travel from the South Pole, where the detector is located, to the furthest reaches of the universe, learning how the detection of high-energy neutrinos has opened a new view to the universe. This novel exhibit combines a multitouch tabletop display system and commercially available virtual reality (VR) head-mounted displays to enable informal STEM learning of polar research. The exhibit, launched in early November 2017 during the Wisconsin Science Festival in Madison, WI, will study how immersive VR can enhance informal STEM learning. The foundation of this project is built upon a strong collaborative effort between the Living Environments Laboratory (LEL), the Wisconsin IceCube Particle Astrophysics Center (WIPAC), and the Field Day Laboratory groups from the University of Wisconsin-Madison campus. The project is funded through an NSF Advancing Informal STEM Learning (AISL) grant, under a special call for engaging students and the public in polar research. This exploratory pathways project seeks to build expertise to allow future extensions. The plan is to submit a subsequent AISL Broad Implementation proposal to add more 3D environments for other Antarctic research topics and locations in the future. We will describe the current implementation of the project and discuss the challenges and opportunities of working with an interdisciplinary team of scientists and technology and education researchers. We will also present preliminary assessment results, which seek to answer questions such as: Did users gain a better understanding of IceCube research from interacting with the exhibit? Do both technologies (touch table and VR headset) provide the same level of engagement? Is one technology better suited for specific learning outcomes?

EDITORIAL: Non-polar and semipolar nitride semiconductors Non-polar and semipolar nitride semiconductors

Science.gov (United States)

Han, Jung; Kneissl, Michael

2012-02-01

Throughout the history of group-III-nitride materials and devices, scientific breakthroughs and technological advances have gone hand-in-hand. In the late 1980s and early 1990s, the discovery of the nucleation of smooth (0001) GaN films on c-plane sapphire and the activation of p-dopants in GaN led very quickly to the realization of high-brightness blue and green LEDs, followed by the first demonstration of GaN-based violet laser diodes in the mid 1990s. Today, blue InGaN LEDs boast record external quantum efficiencies exceeding 80% and the emission wavelength of the InGaN-based laser diode has been pushed into the green spectral range. Although these tremenduous advances have already spurred multi-billion dollar industries, there are still a number of scientific questions and technological issues that are unanswered. One key challenge is related to the polar nature of the III-nitride wurtzite crystal. Until a decade ago all research activities had almost exclusively concentrated on (0001)-oriented polar GaN layers and heterostructures. Although the device characteristics seem excellent, the strong polarization fields at GaN heterointerfaces can lead to a significant deterioration of the device performance. Triggered by the first demonstration non-polar GaN quantum wells grown on LiAlO2 by Waltereit and colleagues in 2000, impressive advances in the area of non-polar and semipolar nitride semiconductors and devices have been achieved. Today, a large variety of heterostructures free of polarization fields and exhibiting exceptional electronic and optical properties have been demonstrated, and the fundamental understanding of polar, semipolar and non-polar nitrides has made significant leaps forward. The contributions in this Semiconductor Science and Technology special issue on non-polar and semipolar nitride semiconductors provide an impressive and up-to-date cross-section of all areas of research and device physics in this field. The articles cover a wide range of

Optics. Observation of optical polarization Möbius strips.

Science.gov (United States)

Bauer, Thomas; Banzer, Peter; Karimi, Ebrahim; Orlov, Sergej; Rubano, Andrea; Marrucci, Lorenzo; Santamato, Enrico; Boyd, Robert W; Leuchs, Gerd

2015-02-27

Möbius strips are three-dimensional geometrical structures, fascinating for their peculiar property of being surfaces with only one "side"—or, more technically, being "nonorientable" surfaces. Despite being easily realized artificially, the spontaneous emergence of these structures in nature is exceedingly rare. Here, we generate Möbius strips of optical polarization by tightly focusing the light beam emerging from a q-plate, a liquid crystal device that modifies the polarization of light in a space-variant manner. Using a recently developed method for the three-dimensional nanotomography of optical vector fields, we fully reconstruct the light polarization structure in the focal region, confirming the appearance of Möbius polarization structures. The preparation of such structured light modes may be important for complex light beam engineering and optical micro- and nanofabrication. Copyright © 2015, American Association for the Advancement of Science.

A Science of Social Work? Response to John Brekke

Science.gov (United States)

Shaw, Ian

2014-01-01

I take the opportunity provided by John Brekke's (2012) article to respond to the general assumptions and approaches that may be brought when considering the question of a science of social work. I consider first, what should be our frames of reference, our communities of interest, or our boundaries of inclusion, for such a discussion?…

Preserving Geological Samples and Metadata from Polar Regions

Science.gov (United States)

Grunow, A.; Sjunneskog, C. M.

2011-12-01

The Office of Polar Programs at the National Science Foundation (NSF-OPP) has long recognized the value of preserving earth science collections due to the inherent logistical challenges and financial costs of collecting geological samples from Polar Regions. NSF-OPP established two national facilities to make Antarctic geological samples and drill cores openly and freely available for research. The Antarctic Marine Geology Research Facility (AMGRF) at Florida State University was established in 1963 and archives Antarctic marine sediment cores, dredge samples and smear slides along with ship logs. The United States Polar Rock Repository (USPRR) at Ohio State University was established in 2003 and archives polar rock samples, marine dredges, unconsolidated materials and terrestrial cores, along with associated materials such as field notes, maps, raw analytical data, paleomagnetic cores, thin sections, microfossil mounts, microslides and residues. The existence of the AMGRF and USPRR helps to minimize redundant sample collecting, lessen the environmental impact of doing polar field work, facilitates field logistics planning and complies with the data sharing requirement of the Antarctic Treaty. USPRR acquires collections through donations from institutions and scientists and then makes these samples available as no-cost loans for research, education and museum exhibits. The AMGRF acquires sediment cores from US based and international collaboration drilling projects in Antarctica. Destructive research techniques are allowed on the loaned samples and loan requests are accepted from any accredited scientific institution in the world. Currently, the USPRR has more than 22,000 cataloged rock samples available to scientists from around the world. All cataloged samples are relabeled with a USPRR number, weighed, photographed and measured for magnetic susceptibility. Many aspects of the sample metadata are included in the database, e.g. geographical location, sample

Innovations in Community-Based and Interdisciplinary Research: A Network Perspective on Innovation in Social Work Science

Science.gov (United States)

Rice, Eric; Petering, Robin; Stringfellow, Erin; Craddock, Jaih B.

2017-01-01

We present a preliminary theory of innovation in social work science. The focus of the piece is two case studies from our work that illustrate the social nature of innovations in the science of social work. This inductive theory focuses on a concept we refer to as transformative innovation, wherein two sets of individuals who possess different…

Optically enhanced nuclear cross polarization in acridine-doped fluorene

Energy Technology Data Exchange (ETDEWEB)

Oshiro, C.M.

1982-06-01

The objective of this work has been to create large polarizations of the dilute /sup 13/C nuclei in the solid state. The idea was to create /sup 1/H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the /sup 13/C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large /sup 1/H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large /sup 13/C polarizations have been created in fluorene single crystals. These large /sup 13/C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined.

Optically enhanced nuclear cross polarization in acridine-doped fluorene

International Nuclear Information System (INIS)

Oshiro, C.M.

1982-06-01

The objective of this work has been to create large polarizations of the dilute 13 C nuclei in the solid state. The idea was to create 1 H polarizations larger than Boltzmann and to use the proton enhanced nuclear induction spectroscopy cross polarization technique to then transfer this large polarization to the 13 C spin system. Optical Nuclear Polarization (ONP) of acridine-doped fluorene single crystals was studied. In addition, ONP of powdered samples of the acridine-doped fluorene was studied. In general, many compounds do not crystallize easily or do not form large crystals suitable for NMR experiments. Powdered, amorphous and randomly dispersed samples are generally far more readily available than single crystals. One objective of this work has been to (first) create large 1 H polarizations. Although large optical proton polarizations in single crystals have been reported previously, optically generated polarizations in powdered samples have not been reported. For these reasons, ONP studies of powdered samples of the acridine-doped fluorene were also undertaken. Using ONP in combination with the proton enhanced nuclear induction spectroscopy experiment, large 13 C polarizations have been created in fluorene single crystals. These large 13 C polarizations have permitted the determination of the seven incongruent chemical shielding tensors of the fluorene molecule. Part 2 of this thesis describes the proton enhanced nuclear induction spectroscopy experiment. Part 3 describes the ONP experiment. Part 4 is a description of the experimental set-up. Part 5 describes the data analysis for the determination of the chemical shielding tensors. Part 6 presents the results of the ONP experiments performed in this work and the chemical shielding tensors determined

Bringing Antarctic Weddell seals to the classroom through PolarTREC

Science.gov (United States)

Eilers, A. A.

2017-12-01

PolarTREC (Teachers and Researchers Exploring and Collaborating) is an NSF funded professional development opportunity in which K-12 teachers and informal educators participated in hands-on field research experiences in the Polar Regions. The program goal is to invigorate polar science education and understanding by bringing together educators and polar researchers. This unique opportunity for educators has two main components: a 4-6 week field experience and a classroom/community connection piece. In preparation for these experiences, museum educator Alex Eilers and science team lead Dr. Jennifer Burns planned, developed and executed extensive outreach efforts for both students and the community to highlight the Weddell seal research project during the 2012, 2014 and 2016 seasons. The following outreach activities summarize the team's most successful attempts at engaging schoolchildren, teachers and the public, creating a broader impact of the Weddell seal scientific project. On-line Daily journal entries were uploaded to the PolarTREC website encouraging an active interaction between the science team and participants. A Polar Connect event offered participants a real-time, interactive internet presentation with the team. Schools A multitude of on-site presentations were made in classrooms, at teacher workshops and faculty meetings. Two 45 minute labs were developed for students visiting the museum, Animals of the Antarctic and Journey to the Poles, the latter is now included in our ongoing program repertoire. Two travelling kits, Extreme Cold Weather Gear and The Weddell Seal, were developed by museum staff and continue to circulate through schools. A multi-lesson educational module was developed by museum staff to bridge the gap between the scientific research conducted in the field and students in grades 3-8. It contains curriculum-based lessons, field data and strategic methods to assist students in analyzing the data. Community Community-wide interest

Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

KAUST Repository

Yan, Long

2018-05-03

Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

KAUST Repository

Yan, Long; Zhang, Yuantao; Han, Xu; Deng, Gaoqiang; Li, Pengchong; Yu, Ye; Chen, Liang; Li, Xiaohang; Song, Junfeng

2018-01-01

Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

Detecting spin polarization of nano-crystalline manganese doped zinc oxide thin film using circular polarized light

Energy Technology Data Exchange (ETDEWEB)

El-Sayed, H.M., E-mail: h_m_elsaid@hotmail.com

2016-02-01

The presence of spin polarization in Mn-doped ZnO thin film is very important for spintronic applications. Spin polarization was detected using simple method. This method depends on measuring the optical transmittance using circular polarized light in visible and near infra-red region. It was found that, there is a difference in the optical energy gap of the film for circular left and circular polarized light. For temperatures > 310 K the difference in energy gap is vanished. This result is confirmed by measuring the magnetic hysteresis of the film. This work introduces a promising method for measuring the ferromagnetism in diluted magnetic semiconductors. - Highlights: • Highly oriented c-axis of Mn-ZnO thin film doped with nitrogen is prepared. • The optical energy gap depends on the state of circularly polarized light. • The presence of spin polarization is confirmed using simple optical method. • Magnetic measurements are consistent with the results of the optical method.

The case for a modern multiwavelength, polarization-sensitive LIDAR in orbit around Mars

International Nuclear Information System (INIS)

Brown, Adrian J.; Michaels, Timothy I.; Byrne, Shane; Sun, Wenbo; Titus, Timothy N.; Colaprete, Anthony; Wolff, Michael J.; Videen, Gorden; Grund, Christian J.

2015-01-01

We present the scientific case to build a multiple-wavelength, active, near-infrared (NIR) instrument to measure the reflected intensity and polarization characteristics of backscattered radiation from planetary surfaces and atmospheres. We focus on the ability of such an instrument to enhance, potentially revolutionize, our understanding of climate, volatiles and astrobiological potential of modern-day Mars. Such an instrument will address the following three major science themes, which we address in this paper: Science Theme 1. Surface. This would include global, night and day mapping of H 2 O and CO 2 surface ice properties. Science Theme 2. Ice Clouds. This would including unambiguous discrimination and seasonal mapping of CO 2 and H 2 O ice clouds. Science Theme 3. Dust Aerosols. This theme would include multiwavelength polarization measurements to infer dust grain shapes and size distributions. - Highlights: • We present the scientific rationale for a multi-wavelength, polarization sensitive lidar to be placed in orbit around Mars. • Scientific questions focus on the Martian climate and modern-day interactions between surface, ice clouds and dust aerosols. • What we would learn about volatile transport and deposition has implications for past, present and future life on Mars

Understanding the spin-driven polarizations in Bi MO3 (M = 3 d transition metals) multiferroics

Science.gov (United States)

Kc, Santosh; Lee, Jun Hee; Cooper, Valentino R.

Bismuth ferrite (BiFeO3) , a promising multiferroic, stabilizes in a perovskite type rhombohedral crystal structure (space group R3c) at room temperature. Recently, it has been reported that in its ground state it possess a huge spin-driven polarization. To probe the underlying mechanism of this large spin-phonon response, we examine these couplings within other Bi based 3 d transition metal oxides Bi MO3 (M = Ti, V, Cr, Mn, Fe, Co, Ni) using density functional theory. Our results demonstrate that this large spin-driven polarization is a consequence of symmetry breaking due to competition between ferroelectric distortions and anti-ferrodistortive octahedral rotations. Furthermore, we find a strong dependence of these enhanced spin-driven polarizations on the crystal structure; with the rhombohedral phase having the largest spin-induced atomic distortions along [111]. These results give us significant insights into the magneto-electric coupling in these materials which is essential to the magnetic and electric field control of electric polarization and magnetization in multiferroic based devices. Research is supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division and the Office of Science Early Career Research Program (V.R.C) and used computational resources at NERSC.

Polarization measurement for internal polarized gaseous targets

International Nuclear Information System (INIS)

Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

2004-01-01

The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

Goethe's Conception of "Experiment as Mediator" and Implications for Practical Work in School Science

Science.gov (United States)

Park, Wonyong; Song, Jinwoong

2018-03-01

There has been growing criticism over the aims, methods, and contents of practical work in school science, particularly concerning their tendency to oversimplify the scientific practice with focus on the hypothesis-testing function of experiments. In this article, we offer a reading of Johann Wolfgang von Goethe's scientific writings—particularly his works on color as an exquisite articulation of his ideas about experimentation—through the lens of practical school science. While avoiding the hasty conclusions made from isolated experiments and observations, Goethe sought in his experiments the interconnection among diverse natural phenomena and rejected the dualistic epistemology about the relation of humans and nature. Based on a close examination of his color theory and its underlying epistemology, we suggest three potential contributions that Goethe's conception of scientific experimentation can make to practical work in school science.

Science, Social Work, and Intervention Research: The Case of "Critical Time Intervention"

Science.gov (United States)

Jenson, Jeffrey M.

2014-01-01

Intervention research is an important, yet often neglected, focus of social work scholars and investigators. The purpose of this article is to review significant milestones and recent advances in intervention research. Methodological and analytical developments in intervention research are discussed in the context of science and social work.…

Quantum mechanical aspects of dynamical neutron polarization

International Nuclear Information System (INIS)

Betz, T.; Badurek, G.; Jericha, E.

2007-01-01

Dynamic Neutron Polarization (DNP) is a concept which allows to achieve complete polarization of slow neutrons, virtually without any loss of intensity. There the neutrons pass through a combination of a static and a rotating magnetic field in resonance, like in a standard NMR apparatus. Depending on their initial spin state, they end up with different kinetic energies and therefore different velocity. In a succeeding magnetic precession field this distinction causes a different total precession angle. Tuning the field strength can lead to a final state where two original anti-parallel spin states are aligned parallel and hence to polarization. The goal of this work is to describe the quantum mechanical aspects of DNP and to work out the differences to the semi-classical treatment. We show by quantum mechanical means, that the concept works and DNP is feasible, indeed. Therefore, we have to take a closer look to the behavior of neutron wave functions in magnetic fields. In the first Section we consider a monochromatic continuous beam. The more realistic case of a pulsed, polychromatic beam requires a time-dependent field configuration and will be treated in the second Section. In particular the spatial separation of the spin up- and down-states is considered, because it causes an effect of polarization damping so that one cannot achieve a fully polarized final state. This effect is not predicted by the semi-classical treatment of DNP. However, this reduction of polarization is very small and can be neglected in realistic DNP-setups

RHIC Proton Luminosity and Polarization Improvement

International Nuclear Information System (INIS)

Zhang, S. Y.

2014-01-01

The RHIC proton beam polarization can be improved by raising the Booster scraping, which also helps to reduce the RHIC transverse emittance, and therefore to improve the luminosity. By doing this, the beam-beam effect would be enhanced. Currently, the RHIC working point is constrained between 2/3 and 7/10, the 2/3 resonance would affect intensity and luminosity lifetime, and the working point close to 7/10 would enhance polarization decay in store. Run 2013 shows that average polarization decay is merely 1.8% in 8 hours, and most fills have the luminosity lifetime better than 14 hours, which is not a problem. Therefore, even without beam-beam correction, there is room to improve for RHIC polarization and luminosity. The key to push the Booster scraping is to raise the Booster input intensity; for that, two approaches can be used. The first is to extend the LINAC tank 9 pulse width, which has been successfully applied in run 2006. The second is to raise the source temperature, which has been successfully applied in run 2006 and run 2012.

Integrated polarization beam splitter with relaxed fabrication tolerances

OpenAIRE

Perez-Galacho, D.; Halir, R.; Ortega-Monux, A.; Alonso-Ramos, C.; Zhang, R.; Runge, P.; Janiak, K.; Bach, H-G; Steffan, A. G.; Molina-Fernandez, I.

2013-01-01

Polarization handling is a key requirement for the next generation of photonic integrated circuits (PICs). Integrated polarization beam splitters (PBS) are central elements for polarization management, but their use in PICs is hindered by poor fabrication tolerances. In this work we present a fully passive, highly fabrication tolerant polarization beam splitter, based on an asymmetrical Mach-Zehnder interferometer (MZI) with a Si/SiO2 Periodic Layer Structure (PLS) on top of one of its arms. ...

A Response to Anastas and Coffey: The Science of Social Work and Its Relationship to Social Work Education and Professional Organizations

Science.gov (United States)

Voisin, Dexter R.; Wong, Marleen; Samuels, Gina Miranda

2014-01-01

Relationships are central to the profession of social work; relationships with allied disciplines, among professional social work organizations, and between classroom and field education. However, embedded within these relationships are historical tensions, and contemporary opportunities that can advance both the science of social work and the…

Towards an International Polar Data Coordination Network

Directory of Open Access Journals (Sweden)

P L Pulsifer

2014-10-01

Full Text Available Data management is integral to sound polar science. Through analysis of documents reporting on meetings of the Arctic data management community, a set of priorities and strategies are identified. These include the need to improve data sharing, make use of existing resources, and better engage stakeholders. Network theory is applied to a preliminary inventory of polar and global data management actors to improve understanding of the emerging community of practice. Under the name the Arctic Data Coordination Network, we propose a model network that can support the community in achieving their goals through improving connectivity between existing actors.

Applying laser speckle images to skin science: skin lesion differentiation by polarization

Science.gov (United States)

Lee, Tim K.; Tchvialeva, Lioudmila; Dhadwal, Gurbir; Sotoodian, Bahman; Kalai, Sunil; Zeng, Haishan; Lui, Harvey; McLean, David I.

2012-01-01

Skin cancer is a worldwide health problem. It is the most common cancer in the countries with a large white population; furthermore, the incidence of malignant melanoma, the most dangerous form of skin cancer, has been increasing steadily over the last three decades. There is an urgent need to develop in-vivo, noninvasive diagnostic tools for the disease. This paper attempts to response to the challenge by introducing a simple and fast method based on polarization and laser speckle. The degree of maintaining polarization estimates the fraction of linearly maintaining polarization in the backscattered speckle field. Clinical experiments of 214 skin lesions including malignant melanomas, squamous cell carcinomas, basal cell carcinomas, nevi, and seborrheic keratoses demonstrated that such a parameter can potentially diagnose different skin lesion types. ROC analyses showed that malignant melanoma and seborrheic keratosis could be differentiated by both the blue and red lasers with the area under the curve (AUC) = 0.8 and 0.7, respectively. Also malignant melanoma and squamous cell carcinoma could be separated by the blue laser (AUC = 0.9), while nevus and seborrheic keratosis could be identified using the red laser (AUC = 0.7). These experiments demonstrated that polarization could be a potential in-vivo diagnostic indicator for skin diseases.

Polarization-controlled asymmetric excitation of surface plasmons

KAUST Repository

Xu, Quan

2017-08-28

Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

Children Working with Text in Science: disparities with 'Literacy Hour' practice

Science.gov (United States)

Peacock, Alan; Weedon, Helen

2002-02-01

The National Literacy Strategy (NLS) provides a coherent plan of what and how children should be taught about non-fiction text. Nevertheless, the difficulties that children actually experience when using science texts are not fully addressed: in particular, the use and interpretation of the visual elements of science text is given limited attention in the prescriptions for teaching the 'Literacy Hour'. Such disparities identified by prior research and by a content analysis of the NLS Framework Document are considered alongside evidence of the difficulties encountered by a class of Year 5 pupils working with a range of non-fiction texts during science lessons. Pupils' text use is studied through observations and interviews with children, through interviews with their teachers and through a questionnaire about text use strategies. The findings suggest that (1) the pupils experienced considerable difficulty in making sense of the science content of non-fiction text, particularly in terms of interpretation of visual elements and their links to written text and (2) use of retrieval strategies taught during the Literacy Hour was not transferred to learning from text during science lessons. The study proposes closer planning of text use in science and literacy lessons.

Reusing Joint Polar Satellite System (jpss) Ground System Components to Process AURA Ozone Monitoring Instrument (omi) Science Products

Science.gov (United States)

Moses, J. F.; Jain, P.; Johnson, J.; Doiron, J. A.

2017-12-01

New Earth observation instruments are planned to enable advancements in Earth science research over the next decade. Diversity of Earth observing instruments and their observing platforms will continue to increase as new instrument technologies emerge and are deployed as part of National programs such as Joint Polar Satellite System (JPSS), Geostationary Operational Environmental Satellite system (GOES), Landsat as well as the potential for many CubeSat and aircraft missions. The practical use and value of these observational data often extends well beyond their original purpose. The practicing community needs intuitive and standardized tools to enable quick unfettered development of tailored products for specific applications and decision support systems. However, the associated data processing system can take years to develop and requires inherent knowledge and the ability to integrate increasingly diverse data types from multiple sources. This paper describes the adaptation of a large-scale data processing system built for supporting JPSS algorithm calibration and validation (Cal/Val) node to a simplified science data system for rapid application. The new configurable data system reuses scalable JAVA technologies built for the JPSS Government Resource for Algorithm Verification, Independent Test, and Evaluation (GRAVITE) system to run within a laptop environment and support product generation and data processing of AURA Ozone Monitoring Instrument (OMI) science products. Of particular interest are the root requirements necessary for integrating experimental algorithms and Hierarchical Data Format (HDF) data access libraries into a science data production system. This study demonstrates the ability to reuse existing Ground System technologies to support future missions with minimal changes.

One directional polarized neutron reflectometry with optimized reference layer method

International Nuclear Information System (INIS)

Masoudi, S. Farhad; Jahromi, Saeed S.

2012-01-01

In the past decade, several neutron reflectometry methods for determining the modulus and phase of the complex reflection coefficient of an unknown multilayer thin film have been worked out among which the method of variation of surroundings and reference layers are of highest interest. These methods were later modified for measurement of the polarization of the reflected beam instead of the measurement of the intensities. In their new architecture, these methods not only suffered from the necessity of change of experimental setup but also another difficulty was added to their experimental implementations. This deficiency was related to the limitations of the technology of the neutron reflectometers that could only measure the polarization of the reflected neutrons in the same direction as the polarization of the incident beam. As the instruments are limited, the theory has to be optimized so that the experiment could be performed. In a recent work, we developed the method of variation of surroundings for one directional polarization analysis. In this new work, the method of reference layer with polarization analysis has been optimized to determine the phase and modulus of the unknown film with measurement of the polarization of the reflected neutrons in the same direction as the polarization of the incident beam.

Women Working in Engineering and Science

Science.gov (United States)

Luna, Bernadette; Kliss, Mark (Technical Monitor)

1998-01-01

The presentation will focus on topics of interest to young women pursuing an engineering or scientific career, such as intrinsic personality traits of most engineers, average salaries for the various types of engineers, appropriate preparation classes at the high school and undergraduate levels, gaining experience through internships, summer jobs and graduate school, skills necessary but not always included in engineering curricula (i.e., multimedia, computer skills, communication skills), the work environment, balancing family and career, and sexual harassment. Specific examples from the speaker's own experience in NASA's Space Life Sciences Program will be used to illustrate the above topics. In particular, projects from Extravehicular Activity and Protective Systems research and Regenerative Life Support research will be used as examples of real world problem-solving to enable human exploration of the solar system.

Inquiry Coaching: Scientists & Science Educators Energizing the Next Generation

Science.gov (United States)

Shope, R. E.; Alcantara Valverde, L.

2007-05-01

A recent National Academy of Sciences report recommends that science educators focus strategically on teaching the practice of science. To accomplish this, we have devised and implemented the Science Performance Laboratory, a collaborative research, education, and workforce model that brings scientists and science educators together to conduct scientific inquiry. In this session, we demonstrate how to form active inquiry teams around Arctica Science Research content areas related to the International Polar Year. We use the term "Arctica Science Research" to refer to the entire scope of exploration and discovery relating to: polar science and its global connections; Arctic and Antarctic research and climate sciences; ice and cryospheric studies on Earth; polar regions of the Moon, Mars, and Mercury; icy worlds throughout the Solar System, such as Europa, Enceladus, Titan, Pluto and the Comets; cryovolcanism; ice in interstellar space, and beyond. We apply the notion of teaching the practice science by enacting three effective strategies: 1) The Inquiry Wheel Game, in which we develop an expanded understanding of what has been traditionally taught as "the scientific method"; 2) Acting Out the Science Story, in which we develop a physicalized expression of our conceptual understanding; and 3) Selecting Success Criteria for Inquiry Coaching, in which we reframe how we evaluate science learning as we teach the practice of science.

An Exploration of Teachers' Efforts to Understand Identity Work and its Relevance to Science Instruction

Science.gov (United States)

Smith, M. Cecil; Darfler, Anne

2012-06-01

US educators express concern that students are turning away from the study of science and have little interest in pursuing science careers. Nationally, science achievement scores for 8th graders are unchanged since 1996, but 12th graders' scores have significantly decreased. A shortcoming of education reform efforts is lack of attention to students' developmental needs. Science study should enable students to learn about themselves—to develop and refine their skills, define their values, explore personal interests, and understand the importance of science to themselves and others. Effective secondary science instruction requires attention to students' identity development—the key developmental task of adolescence. Secondary science teachers participated in an 8-week course focused on understanding adolescent identity development and methods for addressing identity. Transcripts of the teachers' online discussions of salient issues were analyzed to determine their perceptions regarding classroom identity work. Teachers identified several assets and obstacles to identity work that were organized into two broad categories: teacher knowledge, training opportunities, and administrative support, or lack of these; and, presence of inflexible curricula, standardized testing regimes, and increased teacher accountability. Implications for student growth and science teacher professional development are discussed.

Acting Antarctica: science on stage

Science.gov (United States)

Ciceri, Piera; Tizzoni, Paola; Pierro, Luigia

2016-04-01

Key-words: Polar science, Earth science, Theatre, Hands on activities The legendary Antarctic Expedition of sir E. Shackleton and his crew of 27 aboard the Endurance (1914/16) trapped in the Antarctic ice has become the starting point to learn about Polar Science and Climate Change. While the students were involved into this incredible adventure by the astonishing images of the Australian photographer Frank Hurley (who joined the crew), they discovered the world in which this story happened. Students were then involved in hands-on activities and role plays and have become the writers of the play "Uomini a scienza ai confini del mondo". They act the story of Shackelton's expedition and they tell at the same time to the audience about ice pack, ice cores and their role in understanding the past of the climate, physical and geographical characteristic of polar regions, thermal phenomena related to adaptations of polar animals, solar radiation at different latitude, day/night duration. The theater was the place to "stage" some scientific experiments and to explain the current research carried out in polar regions and their importance in climate change studies and to stress some similarities between Antarctica and space. The project was carried out from teachers of science, letters and geography and was born in collaboration with the "Piccolo Teatro di Milano" and the association "Science Under 18" with the support of a professional actor and director and was played for other schools at "EXPO 2015" in Milano (Italy). In our opinion drama activities improve reading comprehension, and both verbal and non-verbal communication skills. To be able to write and to act, students need a deep understanding of contents. Arts, including theatre, are a good key to involve emotionally students. To have an audience different from their own teachers and classmates offers a real task and the opportunity to play and let grow real skills.

Working with Science Teachers to Transform the Opportunity Landscape for Regional and Rural Youth: A Qualitative Evaluation of the Science in Schools Program

Science.gov (United States)

Sheehan, Grania R.; Mosse, Jennifer

2013-01-01

This article reports on a qualitative evaluation of the Science in Schools program; a suite of science based activities delivered by staff of a regional university campus and designed to provide professional development for science teachers working in non-metropolitan schools in a socioeconomically disadvantaged region of Australia. The research…

North Polar Cap

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear.

Science.gov (United States)

Pagano, A M; Durner, G M; Rode, K D; Atwood, T C; Atkinson, S N; Peacock, E; Costa, D P; Owen, M A; Williams, T M

2018-02-02

Regional declines in polar bear ( Ursus maritimus ) populations have been attributed to changing sea ice conditions, but with limited information on the causative mechanisms. By simultaneously measuring field metabolic rates, daily activity patterns, body condition, and foraging success of polar bears moving on the spring sea ice, we found that high metabolic rates (1.6 times greater than previously assumed) coupled with low intake of fat-rich marine mammal prey resulted in an energy deficit for more than half of the bears examined. Activity and movement on the sea ice strongly influenced metabolic demands. Consequently, increases in mobility resulting from ongoing and forecasted declines in and fragmentation of sea ice are likely to increase energy demands and may be an important factor explaining observed declines in body condition and survival. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Production of a Science Documentary and Its Usefulness in Teaching the Nature of Science: Indirect Experience of How Science Works

Science.gov (United States)

Kim, Sun Young; Yi, Sang Wook; Cho, Eun Hee

2014-01-01

In this study, we produced a documentary which portrays scientists at work and critically evaluated the use of this film as a teaching tool to help students develop an understanding of the nature of science. The documentary, "Life as a Scientist: People in Love with 'Caenorhabditis elegans,' a Soil Nematode" encompasses the…

Effect of project work on secondary school students science process ...

African Journals Online (AJOL)

The study investigated the effect of students' project work on secondary school science process skills acquisition in Biology. The study was carried out in Owerri North Local Government Area of Imo State. Three research questions guided the study and three null hypotheses were postulated and tested at 0.05 level of ...

Group monopolization & collaborative work: the making of a science video project

NARCIS (Netherlands)

Jayme, B.; Roth, W.-M.; Reis, G.; Eijck, van M.W.

2007-01-01

ABSTRACT: In the present ethnographic case study, we investigate how monopolization emerges and is maintained during collaborative working situations in elementary science classroom tasks. Our analysis suggests that monopolization is achieved in part by the position of the students around the

On the large COMPASS polarized deuteron target

CERN Document Server

Finger, M; Baum, G; Doshita, N; Finger, M Jr; Gautheron, F; Goertz, St; Hasegawa, T; Heckmann, J; Hess, Ch; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Y; Koivuniemi, J; Kondo, K; Le Goff, J-M; Magnon, A; Marchand, C; Matsuda, T; Meyer, W; Reicherz, G; Srnka, A

2006-01-01

The spin structure of the nucleons is investigated in deep inelastic scattering of a polarized muon beam and a polarized nucleon target in the COMPASS experiment at CERN since 2001. To achieve high luminosities a large solid polarized target is used. The COMPASS polarized target consists of a high cooling power $^{3}$He/$^{4}$He dilution refrigerator capable to maintain working temperature of the target material at about 50mK, a superconducting solenoid and dipole magnet system for longitudinal and transversal magnetic field on the target material, respectively, target cells containing polarizable material, microwave cavities and high power microwave radiation systems for dynamic nuclear polarization and the nuclear magnetic resonance system for nuclear spin polarization measurements. During 2001–2004 experiments superconducting magnet system with opening angle $\\pm$69 mrad, polarized target holder with two target cells and corresponding microwave and NMR systems have been used. For the data taking from 200...

Measurement of the ψ(2S) Production Polarization in pbarp Collisions at √s = 1.8 TeV

Science.gov (United States)

Ngan, Ching-Yuk P.

1997-04-01

We present a measurement of the production polarization of ψ(2S) mesons in pbarp collisions. We consider the decay mode ψ(2S) -> J/ψ π^+ π^- with J/ψ -> μ^+ μ^- in a 110 pb-1 sample collected by the CDF detector during 1992-95. Results are discussed in the context of the color-octet fragmentation production mechanism which is a possible explanation of the anomalous prompt ψ(2S) production cross section. \\$^*We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation.

THE EFFECT OF GRAVITATION ON THE POLARIZATION STATE OF A LIGHT RAY

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Tanay; Sen, A. K. [Department of Physics Assam University, Silchar-788011, Assam (India)

2016-12-10

In the present work, detailed calculations have been carried out on the rotation of the polarization vector of an electromagnetic wave due to the presence of a gravitational field of a rotating body. This has been done using the general expression of Maxwell’s equation in curved spacetime. Considering the far-field approximation (i.e., the impact parameter is greater than the Schwarzschild radius and rotation parameter), the amount of rotation of the polarization vector as a function of impact parameter has been obtained for a rotating body (considering Kerr geometry). The present work shows that the rotation of the polarization vector cannot be observed in the case of Schwarzschild geometry. This work also calculates the rotational effect when considering prograde and retrograde orbits for the light ray. Although the present work demonstrates the effect of rotation of the polarization vector, it confirms that there would be no net polarization of an electromagnetic wave due to the curved spacetime geometry in a Kerr field.

Physics with polarized electrons and targets

International Nuclear Information System (INIS)

Donnelly, T.W.

1984-01-01

With the advent of electron stretcher or storage rings electron scattering from polarized targets becomes a general new tool for nuclear structure studies. Without such facilities it is necessary to have very dense polarized targets for use with the typical (less or approximately equal 50 μA) electron beams available and very few measurements of this type have been attempted. On the other hand, with electron rings the effective circulating current can be greatly increased. In this case much thinner internal targets may be used while still maintaining the same luminosity as in external beam experiments. In ancticipation of such new experimental capabilities we have re-developed the theoretical basis for discussions of electron scattering from polarized targets using either unpolarized or polarized electron beams. This work takes the formalism of unpolarized (e,e') and extends it in a straightforward way to include general polarizations of electrons, target nuclei, recoil nuclei or any combinations of these polarizations. In the present context it is only possible to provide a brief summary of the general form of the cross section and to present a few illustrative examples of the nuclear structure information that may be extracted from such polarization measurements

Polarization control of high order harmonics in the EUV photon energy range.

Science.gov (United States)

Vodungbo, Boris; Barszczak Sardinha, Anna; Gautier, Julien; Lambert, Guillaume; Valentin, Constance; Lozano, Magali; Iaquaniello, Grégory; Delmotte, Franck; Sebban, Stéphane; Lüning, Jan; Zeitoun, Philippe

2011-02-28

We report the generation of circularly polarized high order harmonics in the extreme ultraviolet range (18-27 nm) from a linearly polarized infrared laser (40 fs, 0.25 TW) focused into a neon filled gas cell. To circularly polarize the initially linearly polarized harmonics we have implemented a four-reflector phase-shifter. Fully circularly polarized radiation has been obtained with an efficiency of a few percents, thus being significantly more efficient than currently demonstrated direct generation of elliptically polarized harmonics. This demonstration opens up new experimental capabilities based on high order harmonics, for example, in biology and materials science. The inherent femtosecond time resolution of high order harmonic generating table top laser sources renders these an ideal tool for the investigation of ultrafast magnetization dynamics now that the magnetic circular dichroism at the absorption M-edges of transition metals can be exploited.

The Large Scale Structure: Polarization Aspects R. F. Pizzo

Indian Academy of Sciences (India)

ized radio sources in galaxy clusters and at their outskirts, emphasizing the crucial information provided by the polarized signal on the origin and evolution ..... Evrard, A. E., Gioia, I. M. 2002, in Astrophysics and Space Science Library, Vol. 272,.

Science as Content, Science as Context: Working in the Science Department

Science.gov (United States)

Wildy, Helen; Wallace, John

2004-01-01

In this study we explored how the science department shaped the relationship between a science department head, Mr Greg, and a teacher, Ms Horton, as they grappled with their expectations of, and responsibilities for, teaching and leadership in the daily life in the department. We found that, from their life histories and their positions in the…

77 FR 31592 - Notice of Proposed Information Collection Requests; Institute of Education Sciences; What Works...

Science.gov (United States)

2012-05-29

... Sciences; What Works Clearinghouse SUMMARY: The What Works Clearinghouse (WWC) was established to develop... of Collection: What Works Clearinghouse. OMB Control Number: 1850-0788. Type of Review: Extension.... Abstract: The What Works Clearinghouse (WWC) was established to develop, maintain, and make accessible a...

The Polar Rock Repository: Rescuing Polar Collections for New Research

Science.gov (United States)

Grunow, A.

2016-12-01

Geological field expeditions in polar regions are logistically difficult, financially expensive and can have a significant environmental impact on pristine regions. The scarcity of outcrop in Antarctica (98% ice-covered) makes previously collected rock samples very valuable to the science community. NSF recognized the need for preserving rock, dredge, and terrestrial core samples from polar areas and created the Polar Rock Repository (PRR). The PRR collection allows for full and open access to both samples and metadata via the PRR website. In addition to the physical samples and their basic metadata, the PRR archives supporting materials from the collector, field notebooks, images of the samples, field maps, air photos, thin sections and any associated bibliography/DOI's. Many of these supporting materials are unique. More than 40,000 samples are available from the PRR for scientific analysis to researchers around the globe. Most of the samples cataloged at the PRR were collected more than 30 years ago, some more than 100 years ago. The rock samples and metadata are made available online through an advanced search engine for the PRR website. This allows scientists to "drill down" into search results using categories and look-up object fields similar to websites like Amazon. Results can be viewed in a table, downloaded as a spreadsheet, or plotted on an interactive map that supports display of satellite imagery and bathymetry layers. Samples can be requested by placing them in the `shopping cart'. These old sample collections have been repeatedly used by scientists from around the world. One data request involved locating coal deposits in Antarctica for a global compilation and another for looking at the redox state of batholithic rocks from the Antarctic Peninsula using magnetic susceptibilities of PRR rocks. Sample usage has also included non-traditional geologic studies, such as a search for monopoles in Cenozoic volcanic samples, and remote sensing

Navigating the science-policy spectrum: Opportunities to work on policies related to your research

Science.gov (United States)

Licker, R.; Ekwurzel, B.; Goldman, G. T.; DeLonge, M. S.

2017-12-01

Many scientists conduct research with direct policy relevance, whether it be producing sea-level projections that are taken-up by local decision-makers, or developing new agricultural technologies. All scientists are affected by policies made by their respective local, regional, and federal governments. For example, budgets affect the grant resources available to conduct research and policies on visas influence the accessibility of new positions for foreign scientists. As a result, many scientists would like to engage with the policy domain, and either bring their science to bear on new policies that are in the works (science-for-policy) or inform policies on the scientific research enterprise (policy-for-science). Some scientists prefer to engage and be neutral to the policy outcome, serving primarily as an information resource. Many may choose to also advocate for a particular outcome based on their expertise and experience. Research shows that policy decisions benefit greatly from the input of scientific experts. We explore the spectrum between informing policies in a "non-prescriptive" manner to working on policies in an advocacy space. We highlight tips for successful engagement along this spectrum. Finally, we review current science-for-policy and policy-for-science issues of relevance to the geophysical sciences.

Work-Based Curriculum to Broaden Learners' Participation in Science: Insights for Designers

Science.gov (United States)

Bopardikar, Anushree; Bernstein, Debra; Drayton, Brian; McKenney, Susan

2018-05-01

Around the globe, science education during compulsory schooling is envisioned for all learners regardless of their educational and career aspirations, including learners bound to the workforce upon secondary school completion. Yet, a major barrier in attaining this vision is low learner participation in secondary school science. Because curricula play a major role in shaping enacted learning, this study investigated how designers developed a high school physics curriculum with positive learning outcomes in learners with varied inclinations. Qualitative analysis of documents and semistructured interviews with the designers focused on the curriculum in different stages—from designers' ideas about learning goals to their vision for enactment to the printed materials—and on the design processes that brought them to fruition. This revealed designers' emphases on fostering workplace connections via learning goals and activities, and printed supports. The curriculum supported workplace-inspired, hands-on design-and-build projects, developed to address deeply a limited set of standards aligned learning goals. The curriculum also supported learners' interactions with relevant workplace professionals. To create these features, the designers reviewed other curricula to develop vision and printed supports, tested activities internally to assess content coverage, surveyed states in the USA receiving federal school-to-work grants and reviewed occupational information to choose unit topics and career contexts, and visited actual workplaces to learn about authentic praxis. Based on the worked example, this paper offers guidelines for designing work-based science curriculum products and processes that can serve the work of other designers, as well as recommendations for research serving designers and policymakers.

Polarity of wurtzite crystals by photoelectron diffraction

Czech Academy of Sciences Publication Activity Database

Bartoš, Igor; Romanyuk, Olexandr

2014-01-01

Roč. 315, OCT (2014), s. 506-509 ISSN 0169-4332 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : wurtzite semiconductors * surface polarity * X-ray photoelectron diffraction * XPD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014 http://www.sciencedirect.com/science/article/pii/S016943321400066X

Fighting for life: Religion and science in the work of fish and wildlife biologists

Science.gov (United States)

Geffen, Joel Phillip

Philosophers, historians, and sociologists of science have argued that it is impossible to separate fact from value. Even so, Americans generally demand that scientists be "objective." No bias is permitted in their work. Religious motivations in particular are widely considered anathema within the halls of science. My dissertation addresses both theoretical and practical aspects concerning objectivity in science through an examination of fish and wildlife biologists. I hypothesized that they use the language of objective science as a tool to convince others to protect habitats and species. Further, I claimed that this "rhetoric of science" is employed either consciously or unconsciously on behalf of personal values, and that religious and/or spiritual values figure significantly among these. Regarding the issue's practical applications, I argued in support of Susan Longino's assertion that while subjective influences exist in science, they do not necessarily indicate that objectivity has been sacrificed. My primary methodology is ethnographic. Thirty-five biologists working in the Pacific Northwest were interviewed during the course of summer 2001. Participant ages ranged from 23 to 78. Both genders were represented, as were various ethnic and cultural backgrounds, including Native American. I used a questionnaire to guide respondents through a consistent set of open-ended queries. I organized their answers under four categories: the true, the good, the beautiful, and the holy. The first three were borrowed from the theoretical writings of philosopher Immanuel Kant. The last came from Rudolf Otto's theological work. These categories provided an excellent analytical framework. I found that the great majority of fish and wildlife biologists strive for objectivity. However, they are also informed by powerful contextual values. These are derived from environmental ethics, aesthetic preferences pertaining to ecosystem appearance and function, and visceral experiences of

NQRY Coaching: Scientists and Science Educators Energizing the Next Generation

Science.gov (United States)

Shope, R. E.

2007-12-01

A recent National Academy of Science report recommends that science educators focus strategically on teaching the practice of science. To accomplish this, we have devised and implemented the Science Performance Collaboratory, a collaborative research, education, and workforce model that brings scientists and science educators together to conduct scientific inquiry. In this session, we demonstrate how to form active inquiry teams around Arctica Science Research content areas related to the International Polar Year. We use the term Arctica Science Research to refer to the entire scope of exploration and discovery relating to: polar science and its global connections; Arctic and Antarctic research and climate sciences; ice and cryospheric studies on Earth; polar regions of the Moon, Mars, and Mercury; icy worlds throughout the Solar System, such as Europa, Enceladus, Titan, Pluto and the Comets; cryovolvanism; ice in interstellar space, and beyond. We apply the notion of teaching the practice science by enacting three effective strategies: 1) The Inquiry Wheel Game, in which we develop an expanded understanding of what has been traditionally taught as "the scientific method"; 2) Acting Out the Science Story, in which we develop a physicalized expression of our conceptual understanding; and 3) Selecting Success Criteria for Inquiry Coaching, in which we reframe how we evaluate science learning as we teach the practice of science.

Vertex Degrees and Isomorphic Properties in Complement of an m-Polar Fuzzy Graph

Directory of Open Access Journals (Sweden)

Ch. Ramprasad

2017-01-01

Full Text Available Computational intelligence and computer science rely on graph theory to solve combinatorial problems. Normal product and tensor product of an m-polar fuzzy graph have been introduced in this article. Degrees of vertices in various product graphs, like Cartesian product, composition, tensor product, and normal product, have been computed. Complement and μ-complement of an m-polar fuzzy graph are defined and some properties are studied. An application of an m-polar fuzzy graph is also presented in this article.

Nursing's Boundary Work: Theory Development and the Making of Nursing Science, ca. 1950-1980.

Science.gov (United States)

Tobbell, Dominique A

Beginning in the late 1950s and intensifying through the 1960s and 1970s, nurse educators, researchers, and scholars worked to establish nursing as an academic discipline. These nursing leaders argued that the development of nursing theory was not only critical to nursing's academic project but also to improving nursing practice and patient care. The purpose of the article is to examine the context for the development of nursing theory and the characteristics of early theory development from the 1950s through the early 1980s. The methods used were historical research and analysis of the social, cultural, and political context of nursing theory development from the 1950s through the early 1980s. How this context influenced the work of nurse theorists and researchers in these decades was addressed. The development of nursing theory was influenced by a context that included the increasing complexity of patient care, the relocation of nursing education from hospital-based diploma schools to colleges and universities, and the ongoing efforts of nurses to secure more professional autonomy and authority in the decades after World War II. In particular, from the 1960s through the early 1980s, nurse theorists, researchers, and educators viewed the establishment of nursing science, underpinned by nursing theory, as critical to establishing nursing as an academic discipline. To define nursing science, nurse theorists and researchers engaged in critical boundary work in order to draw epistemic boundaries between nursing science and the existing biomedical and behavioral sciences. By the early 1980s, the boundary work of nurse theorists and researchers was incomplete. Their efforts to define nursing science and establish nursing as an academic discipline were constrained by generational and intraprofessional politics, limited resources, the gendered and hierarchical politics, and the complexity of drawing disciplinary boundaries for a discipline that is inherently

Polarization of Cosmic Microwave Background

International Nuclear Information System (INIS)

Buzzelli, A; Cabella, P; De Gasperis, G; Vittorio, N

2016-01-01

In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross- correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales. (paper)

Polarization observables in Virtual Compton Scattering

Energy Technology Data Exchange (ETDEWEB)

Doria, Luca

2007-10-15

Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p){gamma} was measured at MAMI using the A1 Collaboration three spectrometer setup with Q{sup 2}=0.33 (GeV/c){sup 2}. Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

Polarization observables in Virtual Compton Scattering

International Nuclear Information System (INIS)

Doria, Luca

2007-10-01

Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p)γ was measured at MAMI using the A1 Collaboration three spectrometer setup with Q 2 =0.33 (GeV/c) 2 . Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 33; Issue 4 ... Permittivity; polarization effects; strontium tartrate; thermal properties; dielectric properties. ... It is explained that crystallographic change due to polymorphic phase transition may be occurring in the material, besides the change due to loss of water ...

New Data Services for Polar Investigators from Integrated Earth Data Applications (IEDA)

Science.gov (United States)

Nitsche, F. O.; Ferrini, V.; Morton, J. J.; Arko, R. A.; McLain, K.; O'hara, S. H.; Carbotte, S. M.; Lehnert, K. A.; IEDA Team, I.

2013-12-01

Accessibility and preservation of data is needed to support multi-disciplinary research in the key environmentally sensitive Polar Regions. IEDA (Integrated Earth Data Applications) is a community-based data facility funded by the US National Science Foundation (NSF) to support, sustain, and advance the geosciences by providing data services for observational solid earth data from the Ocean, Earth, and Polar Sciences. IEDA tools and services relevant to the Polar Research Community include the Antarctic and Southern Ocean Data System (ASODS), the U.S. Antarctic Program Data Coordination Center (USAP-DCC), GeoMapApp, as well as a number of services for sample-based data (SESAR and EarthChem). In addition to existing tools, which assist Polar investigators in archiving their data, and creating DIF records for global searches in AMD, IEDA recently added several new tools and services that will provide further support for investigators with the data life cycle process. These include a data management plan (http://www.iedadata.org/compliance/plan) and data compliance reporting tool (http://www.iedadata.org/compliance/report) that will help investigators comply with the requirements of funding agencies such as the National Science Foundation (NSF). Data, especially from challenging Polar Regions, are likely to be used by other scientists for future studies. Therefore, data acknowledgment is an important concern of many investigators. To encourage data acknowledgments by data users, we link references of publications (when known) to datasets and cruises registered within the ASODS system as part of our data curation services (http://www.marine-geo.org/portals/antarctic/references.php). In addition, IEDA offers a data publication service to register scientific data with DOI's, making data sets citable as publications with attribution to investigators as authors. IEDA is a publication agent of the DataCite consortium. Offering such services provides additional incentives

Hybrid fluorescent layer emitting polarized light

Directory of Open Access Journals (Sweden)

Mohammad Mohammadimasoudi

2017-07-01

Full Text Available Semiconductor nanorods have anisotropic absorption and emission properties. In this work a hybrid luminescent layer is produced based on a mixture of CdSe/CdS nanorods dispersed in a liquid crystal that is aligned by an electric field and polymerized by UV illumination. The film emits light with polarization ratio 0.6 (polarization contrast 4:1. Clusters of nanorods in liquid crystal can be avoided by applying an AC electric field with sufficient amplitude. This method can be made compatible with large-scale processing on flexible transparent substrates. Thin polarized light emitters can be used in LCD backlights or solar concentrators to increase the efficiency.

What does "success" in public engagement activities mean? A comparison of goals, motivations and embedded assumptions in four polar outreach activities.

Science.gov (United States)

Roop, H. A.; Salmon, R. A.

2015-12-01

Using four very different polar outreach case studies, we will discuss scientists' motivations, expectations, and institutional incentives (and dis-incentives) to engage with the public, and argue that improved training, evaluation, and academic value needs to be associated with scientist-led communication efforts - as well as clearer fora for sharing best practice in this field. We will illustrate our argument using examples from an Antarctic festival with public lectures and science cafes, outreach associated with an Antarctic expedition, the global launch of a climate change documentary that had a significant focus on Antarctica, and a series of "Polar Weeks" led by an international community of scientists and educators. While there is an excellent culture of accountability in both formal and informal science communication sectors, the same rigour is not applied to the majority of 'outreach' activities that are initiated by the science research community. Many of these activities are undertaken based on 'what feels right' and opportunism, and are proclaimed to be a success based on little or no formal evaluation. As a result, much of this work goes undocumented, is not evaluated from the perspective of the science community, and is rarely subject to peer-review and its associated benefits, including professional rewards. We therefore recommend new opportunities for publication in this field that would encourage science communication theory and practice to better inform each other, and for scientists to gain professional recognition for their efforts in this arena.

Mercury Orbiter: Report of the Science Working Team

Science.gov (United States)

Belcher, John W.; Slavin, James A.; Armstrong, Thomas P.; Farquhar, Robert W.; Akasofu, Syun I.; Baker, Daniel N.; Cattell, Cynthia A.; Cheng, Andrew F.; Chupp, Edward L.; Clark, Pamela E.

1991-01-01

The results are presented of the Mercury Orbiter Science Working Team which held three workshops in 1988 to 1989 under the auspices of the Space Physics and Planetary Exploration Divisions of NASA Headquarters. Spacecraft engineering and mission design studies at the Jet Propulsion Lab were conducted in parallel with this effort and are detailed elsewhere. The findings of the engineering study, summarized herein, indicate that spin stabilized spacecraft carrying comprehensive particles and fields experiments and key planetology instruments in high elliptical orbits can survive and function in Mercury orbit without costly sun shields and active cooling systems.

Report of the workshop on nuclear polarization phenomena

International Nuclear Information System (INIS)

1985-01-01

The third work shop on the study of the nuclear polarization was held in December 1984 at RCNP (Research Center for Nuclear Physics). Osaka University, in advance of the comming international conference. About 80 researchers gathered and discussed both theoretical and experimental aspects of nuclear polarization phenomena. Forty eight papers were presented at the work shop and they are collected in this report. Although almost all of them are written in Japanese, the abstracts are prepared in English. (Aoki, K.)

Reversible Polarization Rotation in Epitaxial Ferroelectric Bilayers

DEFF Research Database (Denmark)

Liu, Guangqing; Zhang, Qi; Huang, Hsin-Hui

2016-01-01

Polarization rotation engineering is a promising path to giant dielectric and electromechanical responses in ferroelectric materials and devices. This work demonstrates robust and reversible in- to out-of-plane polarization rotation in ultrathin (nanoscale) epitaxial (001) tetragonal PbZr0.3Ti0.7O3...... large-scale polarization rotation switching (≈60 μC cm−2) and an effective d 33 response 500% (≈250 pm V−1) larger than the PZT-R layer alone. Furthermore, this enhancement is stable for more than 107 electrical switching cycles. These bilayers present a simple and highly controllable means to design...... and optimize rotational polar systems as an alternate to traditional composition-based approaches. The precise control of the subtle interface-driven interactions between the lattice and the external factors that control polarization opens a new door to enhanced—or completely new—functional properties....

Ground-based Polarization Remote Sensing of Atmospheric Aerosols and the Correlation between Polarization Degree and PM2.5

International Nuclear Information System (INIS)

Cheng, Chen; Zhengqiang, Li; Weizhen, Hou; Yisong, Xie; Donghui, Li; Kaitao, Li; Ying, Zhang

2014-01-01

The ground-based polarization remote sensing adds the polarization dimension information to traditional intensity detection, which provides a new method to detect atmospheric aerosols properties. In this paper, the polarization measurements achieved by a new multi-wavelength sun photometer, CE318-DP, are used for the ground-based remote sensing of atmospheric aerosols. In addition, a polarized vector radiative transfer model is introduced to simulate the DOLP (Degree Of Linear Polarization) under different sky conditions. At last, the correlative analysis between mass density of PM 2.5 and multi-wavelength and multi-angular DOLP is carried out. The result shows that DOLP has a high correlation with mass density of PM 2.5 , R 2 >0.85. As a consequence, this work provides a new method to estimate the mass density of PM 2.5 by using the comprehensive network of ground-based sun photometer

Graduate teaching assistants' perceptions of teaching competencies required for work in undergraduate science labs

Science.gov (United States)

Deacon, Christopher; Hajek, Allyson; Schulz, Henry

2017-11-01

Many post-secondary institutions provide training and resources to help GTAs fulfil their teaching roles. However, few programmes focus specifically on the teaching competencies required by GTAs who work with undergraduate students in laboratory settings where learning tends to be more active and inquiry based than in classroom settings. From a review of 8 GTA manuals, we identified 20 competencies and then surveyed faculty and lab coordinators (FIS) and GTAs from a Faculty of Science at a comprehensive Canadian university to identify which of those competencies are required of GTAs who work in undergraduate science labs. GTAs and FIS did not significantly differ in the competencies they view as required for GTAs to work effectively in undergraduate labs. But, when comparing the responses of GTAs and FIS to TA manuals, 'Clearly and effectively communicates ideas and information with students' was the only competency for which there was agreement on the level of requirement. We also examined GTAs' self-efficacy for each of the identified competencies and found no overall relationship between self-efficacy and demographic characteristics, including experience and training. Our results can be used to inform the design of training programmes specifically for GTAs who work in undergraduate science labs, for example, programmes should provide strategies for GTAs to obtain feedback which they can use to enhance their teaching skills. The goal of this study is to improve undergraduate lab instruction in faculties of science and to enhance the teaching experience of GTAs by better preparing them for their role.

Proceedings of the workshop on polarized targets in storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1984-08-01

Polarization phenomena have played an increasingly important part in the study of nuclei and nucleons in recent years. Polarization studies have been hampered by the relatively few and rather fragile polarized targets which are presently available. The concept of polarized gas targets in storage rings opens a much wider range of possibilities than is available in the external target geometry. This novel method will represent a considerable advance in nuclear physics and will continue to receive much attention in plans for future facilities. An internal, polarized-target station is being planned for the cooler ring at the Indiana University Cyclotron Facility. Internal targets are compatible with recent designs of electron accelerators proposed by the Massachusetts Institute of Technology and the Southeastern Universities Research Association. The key to nuclear-science programs based on internal targets pivots on recent developments in polarized atomic beam methods, which include the more recent laser-driven polarized targets. The workshop drew together a unique group of physicists in the fields of high-energy, nuclear and atomic physics. The meeting was organized in a manner that stimulated discussion among the 58 participants and focused on developments in polarized target technology and the underlying atomic physics. An impressive array of future possibilities for polarized targets as well as current developments in polarized target technology were discussed at the workshop. Abstracts of individual items from the workshop were prepared separately for the data base

High magnetic field uniformity superconducting magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat with 'warm' aperture diameter of 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements using a NMR-magnetometer are given. The MPT set-up is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the Synchrophasotron of the Laboratory of High Energies (LHE), JINR, Dubna

Proceedings of the Workshop on future of nuclear physics in Europe with polarized electrons and photons

International Nuclear Information System (INIS)

Didelez, J.P.; Tamas, G.

1990-01-01

In the proceedings of the workshop, held at the Institut de Physique Nucleaire in Orsay, France, full texts of 20 contributions are presented. The two main topics were polarized electrons and polarized photons. It has been reported that significant processes have been made recently in the science and technology of polarized electron sources, polarized targets and polarimeters. The relevant tools are therefore now available to complete extensive experimental programs. The 20 papers are indexed and abstracted separately for the INIS database. (R.P.)

Magnetic field generation by circularly polarized laser light and inertial plasma confinement in a miniature 'Magnetic Bottle' induced by circularly polarized laser light

International Nuclear Information System (INIS)

Kolka, E.

1993-07-01

A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested in this work. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss. In this configuration the circularly polarized laser light is used to get confinement of a plasma contained in a good conductor vessel. The poloidal magnetic field induced by the circularly polarized laser and the efficiency of laser absorption by the plasma are calculated in this work. The confinement in this scheme is supported by the magnetic forces and the Lawson criterion for a DT plasma might be achieved for number density n=5*10 21 cm -3 and confinement time τ= 20 nsec. The laser and the plasma parameters required to get an energetic gain are calculated. (authors)

The potential improvement of team-working skills in Biomedical and Natural Science students using a problem-based learning approach

OpenAIRE

Forough L. Nowrouzian; Anne Farewell

2013-01-01

Teamwork has become an integral part of most organisations today, and it is clearly important in Science and other disciplines. In Science, research teams increase in size while the number of single-authored papers and patents decline. Team-work in laboratory sciences permits projects that are too big or complex for one individual to be tackled. This development requires that students gain experience of team-work before they start their professional career. Students working in teams this may ...

The potential improvement of team-working skills in Biomedical and Natural Science students using a problem-based learning approach

Directory of Open Access Journals (Sweden)

Forough L. Nowrouzian

2013-08-01

Full Text Available Teamwork has become an integral part of most organisations today, and it is clearly important in Science and other disciplines. In Science, research teams increase in size while the number of single-authored papers and patents decline. Team-work in laboratory sciences permits projects that are too big or complex for one individual to be tackled. This development requires that students gain experience of team-work before they start their professional career. Students working in teams this may increase productivity, confidence, innovative capacity and improvement of interpersonal skills. Problem-based learning (PBL is an instructional approach focusing on real analytical problems as a means of training an analytical scientist. PBL may have a positive impact on team-work skills that are important for undergraduates and postgraduates to enable effective collaborative work. This survey of the current literature explores the development of the team-work skills in Biomedical Science students using PBL.

Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

International Nuclear Information System (INIS)

Pierce, Josh; Zhao, J. K.; Crabb, Don

2009-01-01

The recently constructed Spallation Neutron Source at the Oak Ridge National Laboratory is quickly becoming the world's leader in neutron scattering sciences. In addition to the world's most intense pulsed neutron source, we are continuously constructing state of the art neutron scattering instruments as well as sample environments to address today and tomorrow's challenges in materials research. The Dynamically Polarized Sample project at the SNS is aimed at taking maximum advantage of polarized neutron scattering from polarized samples, especially biological samples that are abundant in hydrogen. Polarized neutron scattering will allow us drastically increase the signal to noise ratio in experiments such as neutron protein crystallography. The DPS project is near completion and all key components have been tested. Here we report the current status of the project.

Log-periodic dipole antenna with low cross-polarization

DEFF Research Database (Denmark)

Pivnenko, Sergey

2006-01-01

In this work, log-periodic antennas with improved cross-polarization level were studied. It was found that some modifications of the traditional design lead to an essential improvement of the co-to-cross polarization ratio up to 40 dB. An improved design of a log-periodic dipole antenna with low...

Polarization of lanthanum nucleus by dynamic polarization method

International Nuclear Information System (INIS)

Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

1989-01-01

Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

Linearly Polarized IR Spectroscopy Theory and Applications for Structural Analysis

CERN Document Server

Kolev, Tsonko

2011-01-01

A technique that is useful in the study of pharmaceutical products and biological molecules, polarization IR spectroscopy has undergone continuous development since it first emerged almost 100 years ago. Capturing the state of the science as it exists today, "Linearly Polarized IR Spectroscopy: Theory and Applications for Structural Analysis" demonstrates how the technique can be properly utilized to obtain important information about the structure and spectral properties of oriented compounds. The book starts with the theoretical basis of linear-dichroic infrared (IR-LD) spectroscop

Electro- and photonuclear physics with polarized beams and targets

International Nuclear Information System (INIS)

Holt, R.J.

1987-01-01

Two long-standing issues in photonuclear physics, the giant M1 resonance in Pb and deuteron photodisintegration, have been studied recently with polarized photons at Urbana and Frascati, respectively. The implications that this work has for settling these key issues will be discussed. In addition, the advantages of the internal polarized target method for electron scattering studies will be discussed and the technology of internal polarized target development will be reviewed. The first results from a spin-exchange, optically-pumped polarized H and D source will be presented

Polarized neutrons

International Nuclear Information System (INIS)

Williams, W.G.

1988-01-01

The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

NMR-Based Identification of Metabolites in Polar and Non-Polar Extracts of Avian Liver.

Science.gov (United States)

Fathi, Fariba; Brun, Antonio; Rott, Katherine H; Falco Cobra, Paulo; Tonelli, Marco; Eghbalnia, Hamid R; Caviedes-Vidal, Enrique; Karasov, William H; Markley, John L

2017-11-16

Metabolites present in liver provide important clues regarding the physiological state of an organism. The aim of this work was to evaluate a protocol for high-throughput NMR-based analysis of polar and non-polar metabolites from a small quantity of liver tissue. We extracted the tissue with a methanol/chloroform/water mixture and isolated the polar metabolites from the methanol/water layer and the non-polar metabolites from the chloroform layer. Following drying, we re-solubilized the fractions for analysis with a 600 MHz NMR spectrometer equipped with a 1.7 mm cryogenic probe. In order to evaluate the feasibility of this protocol for metabolomics studies, we analyzed the metabolic profile of livers from house sparrow ( Passer domesticus ) nestlings raised on two different diets: livers from 10 nestlings raised on a high protein diet (HP) for 4 d and livers from 12 nestlings raised on the HP diet for 3 d and then switched to a high carbohydrate diet (HC) for 1 d. The protocol enabled the detection of 52 polar and nine non-polar metabolites in ¹H NMR spectra of the extracts. We analyzed the lipophilic metabolites by one-way ANOVA to assess statistically significant concentration differences between the two groups. The results of our studies demonstrate that the protocol described here can be exploited for high-throughput screening of small quantities of liver tissue (approx. 100 mg wet mass) obtainable from small animals.

The BNL polarized H- ion source development program

International Nuclear Information System (INIS)

Kponou, A.; Alessi, J.; Hershcovitch, A.; DeVito, B.

1992-01-01

Polarized protons have been available for acceleration in the AGS for the high energy physics program since 1984. The polarized H - source, PONI-1, has routinely supplied a 0.4 Hz, 400 μsec pulse having a nominal intensity of 40 μA. Polarization is ∼80% out of the ion source. After PONI- 1 became operational, a program was initiated to develop a more intense source based on a cold ground state atomic beam source, followed by ionization of the polarized H degrees beam by D - charge exchange. Various phases of this work have been fully reported elsewhere, and only a summary is given here

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 40; Issue 3. Effect of composition on the polarization and ohmic resistances of LSM/YSZ composite cathodes in solid oxide fuel cell. B SHRI PRAKASH S SENTHIL KUMAR S T ARUNA. Volume 40 Issue 3 June 2017 pp 441-452 ...

An Octave/MATLAB® Interface for Rapid Processing of SMOS L1C Full Polarization Brightness Temperature

Directory of Open Access Journals (Sweden)

Pablo Saavedra

2018-01-01

Full Text Available A tool to process the SMOS microwave radiometer level 1C polarized brightness temperatures data product has been developed. The SMOS L1C science product contains the dual and full (Stokes vector polarization brightness temperatures at L-band for multiple incidence angles. In order to use the L1C product, the measurements are processed by a number of procedures including radio frequency interference (RFI filters, conversion of the polarization plane from the antenna (X- & Y-pol to the Earth’s surface frame (H- & V-pol, and averaging to fixed classes of incidence angles. The software allows for the processing of data for the entire daily half-orbit product, or for specific regions of interest, and can be adapted as a bash-job to process a large number of data files e.g. for time series analysis. This paper describes the tool which was developed in GNU C++ with the capability to be compiled as MEX function to work with Octave or MATLAB® without any source code adjustment. Funding statement: 'Deutsche Forschungsgemeinschaft' DFG under grant number SI 606/24-1.

Crafting a Future in Science: Tracing Middle School Girls' Identity Work over Time and Space

Science.gov (United States)

Barton, Angela Calabrese; Kang, Hosun; Tan, Edna; O'Neill, Tara B.; Bautista-Guerra, Juanita; Brecklin, Caitlin

2013-01-01

The underrepresentation of girls from nondominant backgrounds in the sciences and engineering continues despite recent gains in achievement. This longitudinal ethnographic study traces the identity work that girls from nondominant backgrounds do as they engage in science-related activities across school, club, and home during the middle school…

Integrated polarization beam splitter with relaxed fabrication tolerances.

Science.gov (United States)

Pérez-Galacho, D; Halir, R; Ortega-Moñux, A; Alonso-Ramos, C; Zhang, R; Runge, P; Janiak, K; Bach, H-G; Steffan, A G; Molina-Fernández, Í

2013-06-17

Polarization handling is a key requirement for the next generation of photonic integrated circuits (PICs). Integrated polarization beam splitters (PBS) are central elements for polarization management, but their use in PICs is hindered by poor fabrication tolerances. In this work we present a fully passive, highly fabrication tolerant polarization beam splitter, based on an asymmetrical Mach-Zehnder interferometer (MZI) with a Si/SiO(2) Periodic Layer Structure (PLS) on top of one of its arms. By engineering the birefringence of the PLS we are able to design the MZI arms so that sensitivities to the most critical fabrication errors are greatly reduced. Our PBS design tolerates waveguide width variations of 400nm maintaining a polarization extinction ratio better than 13dB in the complete C-Band.

"Solidarity and Support": Feminist Memory Work Focus Groups with Working-Class Women Studying Social Science Degrees in Australia

Science.gov (United States)

Michell, Dee; Beddoe, Liz; Fraser, Heather; Jarldorn, Michele

2017-01-01

This paper reports on our use of a two-phased, feminist memory work in a project conducted with 11 women, social science students at an Australian university. We begin by describing government-led attempts to widen participation in Australian universities because 10 of the 11 women who participated in our project were from…

The Federation of Earth Science Information Partners (ESIP Federation): Facilitating Partnerships that Work to Bring Earth Science Data into Educational Settings

Science.gov (United States)

Freuder, R.; Ledley, T. S.; Dahlman, L.

2004-12-01

The Federation of Earth Science Information Partners (ESIP Federation, http://www.esipfed.org) formed seven years ago and now with 77 member organizations is working to "increase the quality and value of Earth science products and services .for the benefit of the ESIP Federation's stakeholder communities." Education (both formal and informal) is a huge audience that we serve. Partnerships formed by members within the ESIP Federation have created bridges that close the gap between Earth science data collection and research and the effective use of that Earth science data to explore concepts in Earth system science by the educational community. The Earth Exploration Toolbook is one of those successful collaborations. The Earth Exploration Toolbook (EET, http://serc.carleton.edu/eet) grew out of a need of the educational community (articulated by the Digital Library for Earth System Education (DLESE) community) to have better access to Earth science data and data analysis tools and help in effectively using them with students. It is a collection of web-accessible chapters, each featuring step-by-step instructions on how to use an Earth science dataset and data analysis tool to investigate an issue or concept in Earth system science. Each chapter also provides the teacher information on the outcome of the activity, grade level, standards addressed, learning goals, time required, and ideas for exploring further. The individual ESIP Federation partners alone could not create the EET. However, the ESIP Federation facilitated the partnering of members, drawing from data providers, researchers and education tool developers, to create the EET. Interest in the EET has grown since it went live with five chapters in July 2003. There are currently seven chapters with another six soon to be released. Monthly online seminars in which over a hundred educators have participated have given very positive feedback. Post workshop surveys from our telecon-online workshops indicate that

Satellite stories: capturing professional experiences of academic health sciences librarians working in delocalized health sciences programs.

Science.gov (United States)

Phinney, Jackie; Horsman, Amanda Rose

2018-01-01

Health sciences training programs have progressively expanded onto satellite campuses, allowing students the opportunity to learn in communities away from an academic institution's main campus. This expansion has encouraged a new role for librarians to assume, in that a subset of health sciences librarians identify as "satellite librarians" who are permanently located at a distance from the main campus. Due to the unique nature of this role and lack of existing data on the topic, the authors investigated the experiences and perceptions of this unique group of information professionals. An electronic survey was distributed to health sciences librarians via two prominent North American email discussion lists. Questions addressed the librarians' demographics, feelings of social inclusion, technological support, autonomy, professional support, and more. Eighteen surveys were analyzed. While several respondents stated that they had positive working relationships with colleagues, many cited issues with technology, scheduling, and lack of consideration as barriers to feeling socially included at both the parent and local campuses. Social inclusion, policy creation, and collection management issues were subject to their unique situations and their colleagues' perceptions of their roles as satellite librarians. The results from this survey suggest that the role of the academic health sciences librarian at the satellite campus needs to be clearly communicated and defined. This, in turn, will enhance the experience for the librarian and provide better service to the client.

First-Principles Study of the Polar TiC/Ti Interface

Institute of Scientific and Technical Information of China (English)

Limin LIU; Shaoqing WANG; Hengqiang YE

2003-01-01

The interface structure, work of adhesion, and bonding character of the polar TiC/Ti interface have been examined by the first-principles density functional plane-wave pseudopotential calculations. Both Ti- and C-terminated interfaces including six different interface structures were calculated, which present quite different features. For the Ti-terminated interface, the interfacial Ti-Ti bond has a strong metallic and weak covalent character; while for the C-terminated interface, the interfacial bond is a strong polar covalent interaction between the Ti-3d and C-2p orbital.The work of adhesion of C-terminated interface is nearly 9 J/m2 stronger than that of the Ti-terminated. It is found that each termination has relatively large work of adhesion, which is consistent with other polar interfaces.

Continuous control of spin polarization using a magnetic field

Science.gov (United States)

Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y.

2016-05-01

The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

Continuous control of spin polarization using a magnetic field

International Nuclear Information System (INIS)

Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y.

2016-01-01

The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

Continuous control of spin polarization using a magnetic field

Energy Technology Data Exchange (ETDEWEB)

Gifford, J. A.; Zhao, G. J.; Li, B. C.; Tracy, Brian D.; Zhang, J.; Kim, D. R.; Smith, David J.; Chen, T. Y., E-mail: tingyong.chen@asu.edu [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)

2016-05-23

The giant magnetoresistance (GMR) of a point contact between a Co/Cu multilayer and a superconductor tip varies for different bias voltage. Direct measurement of spin polarization by Andreev reflection spectroscopy reveals that the GMR change is due to a change in spin polarization. This work demonstrates that the GMR structure can be utilized as a spin source and that the spin polarization can be continuously controlled by using an external magnetic field.

Circularly Polarized Microwave Antenna Element with Very Low Off-Axis Cross-Polarization

Science.gov (United States)

Greem. David; DuToit, Cornelis

2013-01-01

The goal of this work was to improve off-axis cross-polarization performance and ease of assembly of a circularly polarized microwave antenna element. To ease assembly, the initial design requirement of Hexweb support for the internal circuit part, as well as the radiating disks, was eliminated. There is a need for different plating techniques to improve soldering. It was also desirable to change the design to eliminate soldering as well as the need to use the Hexweb support. Thus, a technique was developed to build the feed without using solder, solving the lathing and soldering issue. Internal parts were strengthened by adding curvature to eliminate Hexweb support, and in the process, the new geometries of the internal parts opened the way for improving the off-axis cross-polarization performance as well. The radiating disks curvatures were increased for increased strength, but it was found that this also improved crosspolarization. Optimization of the curvatures leads to very low off-axis cross-polarization. The feed circuit was curved into a cylinder for improved strength, eliminating Hexweb support. An aperture coupling feed mechanism eliminated the need for feed pins to the disks, which would have required soldering. The aperture coupling technique also improves cross-polarization performance by effectively exciting the radiating disks very close to the antenna s central axis of symmetry. Because of the shape of the parts, it allowed for an all-aluminum design bolted together and assembled with no solder needed. The advantage of a solderless design is that the reliability is higher, with no single-point failure (solder), and no need for special plating techniques in order to solder the unit together. The shapes (curved or round) make for a more robust build without extra support materials, as well as improved offaxis cross-polarization.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 39; Issue 7. Theoretical study of built-in-polarization effect on relaxation time and mean free path of phonons in Al x Ga 1 − x N alloy. B K SAHOO A PANSARI. Volume 39 Issue 7 December 2016 pp 1835-1841 ...

Plasma science and engineering at NSF

International Nuclear Information System (INIS)

Goldberg, L.S.

1996-01-01

The author gives a perspective of the breadth of fundamental plasma science and engineering that the National Science Foundation supports through its Directorates for Engineering, Mathematical and Physical Sciences, Geosciences, and the Office of Polar Programs. He plans also to discuss the diverse interests and commitment within the Foundation to maintaining the vitality of research and education activities in this field

Investigating circular patterns in linear polarization observations of Venus

NARCIS (Netherlands)

Mahapatra, G.; Stam, D.M.; Rossi, L.C.G.; Rodenhuis, M.; Snik, Frans; Keller, C.U.

2017-01-01

In this work, we analyse linear polarization data of the planet at a distance, obtained with the Extreme Polarimeter (ExPo) on the William Herschel Telescope
on La Palma. These spatially resolved, high-accuracy polarization observations of Venus show faint circular patterns centered on the

Observation of Polarization Vortices in Momentum Space

Science.gov (United States)

Zhang, Yiwen; Chen, Ang; Liu, Wenzhe; Hsu, Chia Wei; Wang, Bo; Guan, Fang; Liu, Xiaohan; Shi, Lei; Lu, Ling; Zi, Jian

2018-05-01

The vortex, a fundamental topological excitation featuring the in-plane winding of a vector field, is important in various areas such as fluid dynamics, liquid crystals, and superconductors. Although commonly existing in nature, vortices were observed exclusively in real space. Here, we experimentally observed momentum-space vortices as the winding of far-field polarization vectors in the first Brillouin zone of periodic plasmonic structures. Using homemade polarization-resolved momentum-space imaging spectroscopy, we mapped out the dispersion, lifetime, and polarization of all radiative states at the visible wavelengths. The momentum-space vortices were experimentally identified by their winding patterns in the polarization-resolved isofrequency contours and their diverging radiative quality factors. Such polarization vortices can exist robustly on any periodic systems of vectorial fields, while they are not captured by the existing topological band theory developed for scalar fields. Our work provides a new way for designing high-Q plasmonic resonances, generating vector beams, and studying topological photonics in the momentum space.

ispace's Polar Ice Explorer: Commerically Exploring the Poles of the Moon

Science.gov (United States)

Calzada-Diaz, A.; Acierno, K.; Rasera, J. N.; Lamamy, J.-A.

2018-04-01

This work provides the background, rationales, and scientific objectives for the ispace Polar Ice Explorer Project, an ISRU exploratory mission that aims to provide data about the lunar polar environment.

Workshop on polarized neutron filters and polarized pulsed neutron experiments

International Nuclear Information System (INIS)

Itoh, Shinichi

2004-07-01

The workshop was held in KEK by thirty-three participants on April 26, 2004. The polarized neutron filter method was only discussed. It consists of three parts; the first part was discussed on the polarized neutron methods, the second part on the polarized neutron experiments and the third on the pulse neutron spectrometer and polarized neutron experiments. The six papers were presented such as the polarized 3 He neutron spin filter, neutron polarization by proton polarized filter, soft master and neutron scattering, polarized neutron in solid physics, polarization experiments by chopper spectroscope and neutron polarization system in superHRPD. (S.Y.)

The Community-based Organizations Working Group of the Space Science Education Support Network

Science.gov (United States)

Lutz, J. H.; Lowes, L. L.; Asplund, S.

2004-12-01

The NASA Space Science Support Network Community-based Organizations Working Group (CBOWG) has been working for the past two years on issues surrounding afterschool programs and programs for youth (e.g., Girl Scouts, Boy Scouts, Boys and Girls Clubs, 4-H, summer camps, afterschool and weekend programs for various ages, programs with emphases on minority youth). In this session the co-leaders of the CBOWG will discuss the challenges of working with community-based organizations on a regional or national level. We will highlight some ties that we have forged with the National Institute for Out of School Time (NIOST) and the National Afterschool Association (NAA). We will also talk about efforts to coordinate how various entities within NASA cooperate with community-based organizations to serve the best interests of these groups. We will give a couple of examples of how NASA space science organizations have partnered with community-based organizations. The session will include some handouts of information and resources that the CBOWG has found useful in developing an understanding of this segment of informal education groups. We would like to thank NASA for providing resources to support the work of the CBOWG.

Education of natural science in the work of the Municipal Center for Extracurricular Activities

Science.gov (United States)

Jokin, I.

2012-04-01

In the description of my work I presented my own experience in the organizing and carrying out of extracurricular activities with the students, the used modes and methods of work, the obtained results and some good practices in the field of natural sciences. Organizing and carrying out of scientific festivals, participation in joint projects together with scientific organizations. Key words: European dimension, interactive methods, key competences, natural sciences, extracurricular activities. We are witnesses of a fundamental change in the pedagogical culture and practice in our schools to establish the parameters of the quality of training. The good scientific culture is an important part of the students' education. Unfortunately, at the present time the scientific and technological culture is on a low level. One of the contemporary problems and realities of the education in natural science school subjects, as a whole and in particular in the secondary education, is the decreased interest for the training in them and in particular in physics, as well as synchronization of the interrelations: school environment - society. In many countries there is a drop in the orientation of the students towards the science and technology - the problem of Science and Technology (S&T). The training of the young people often creates some problems. The teachers meet with the problem of insufficient motivation of the learners for study and difficulties that they encounter in the process of training. The students find it difficult to apply the mastered knowledge to an applied context. The knowledge is rather academic and rather remote from the context, in which the children live and communicate, which makes it nonfunctional. At present there are not enough extracurricular activities that should meet these necessities of the Bulgarian school. The reasons are various, but they mainly consist in the lack of a material base, an exchange of experience and good practices and motivation

Electromagnetic cloaking devices for TE and TM polarizations

International Nuclear Information System (INIS)

Bilotti, Filiberto; Tricarico, Simone; Vegni, Lucio

2008-01-01

In this paper, we present the design of an electromagnetic cloaking device working for both transverse electric (TE) and transverse magnetic (TM) polarizations. The theoretical approach to cloaking used here is inspired by the one presented by Alu and Engheta (2005 Phys. Rev. E 72 016623) for TM polarization. The case of TE polarization is firstly considered and, then, an actual inclusion-based cloak for TE polarization is also designed. In such a case, the cloak is made of a mu-near-zero (MNZ) metamaterial, as the dual counterpart of the epsilon-near-zero (ENZ) material that can be used for purely dielectric objects. The operation and the robustness of the cloaking device for the TE polarization is deeply investigated through a complete set of full-wave numerical simulations. Finally, the design and an application of a cloak operating for both TE and TM polarizations employing both magnetic inclusions and the parallel plate medium already used by Silveirinha et al (Phys. Rev. E 75 036603) are presented.

THE LINE POLARIZATION WITHIN A GIANT Lyα NEBULA

International Nuclear Information System (INIS)

Prescott, Moire K. M.; Smith, Paul S.; Schmidt, Gary D.; Dey, Arjun

2011-01-01

Recent theoretical work has suggested that Lyα nebulae could be substantially polarized in the Lyα emission line, depending on the geometry, kinematics, and powering mechanism at work. Polarization observations can therefore provide a useful constraint on the source of ionization in these systems. In this Letter, we present the first Lyα polarization measurements for a giant Lyα nebula at z∼ 2.656. We do not detect any significant linear polarization of the Lyα emission: P Lyα = 2.6% ± 2.8% (corrected for statistical bias) within a single large aperture. The current data also do not show evidence for the radial polarization gradient predicted by some theoretical models. These results rule out singly scattered Lyα (e.g., from the nearby active galactic nucleus, AGN) and may be inconsistent with some models of backscattering in a spherical outflow. However, the effects of seeing, diminished signal-to-noise ratio, and angle averaging within radial bins make it difficult to put strong constraints on the radial polarization profile. The current constraints may be consistent with higher density outflow models, spherically symmetric infall models, photoionization by star formation within the nebula or the nearby AGN, resonant scattering, or non-spherically symmetric cold accretion (i.e., along filaments). Higher signal-to-noise ratio data probing to higher spatial resolution will allow us to harness the full diagnostic power of polarization observations in distinguishing between theoretical models of giant Lyα nebulae.

Polarized electrogowdy spacetimes censored

International Nuclear Information System (INIS)

Nungesser, Ernesto

2010-01-01

A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

Polarized electrogowdy spacetimes censored

Energy Technology Data Exchange (ETDEWEB)

Nungesser, Ernesto, E-mail: ernesto.nungesser@aei.mpg.d [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, 14476 Potsdam (Germany)

2010-05-01

A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

Upgrading the AGS polarized beam facility

International Nuclear Information System (INIS)

Ratner, L.G.

1991-01-01

Although present techniques for crossing depolarizing resonances in circular accelerators work, they are very time-consuming to implement and were only able to provide about a 40% polarized beam at 22 GeV in the Alternating Gradient Synchrotron (AGS). We propose to install a partial ''Siberian Snake'' solenoid in the AGS to eliminate the need to correct imperfection resonances and to make other modifications in our intrinsic resonance correctors. This will allow us to reach an energy of 25 GeV with 70% polarization and will enable the AGS to be an efficient injector of polarized protons into the Relativistic Heavy Ion Collider (RHIC), as well as being able to carry on a fixed-target program with minimum set-up time. 3 refs., 5 figs., 1 tab

Planning for a new polarized source

International Nuclear Information System (INIS)

Clegg, T.B.

1985-01-01

In anticipation of obtaining funds for a new polarized source, the authors have tried to stay abreast of new source technological developments. In particular, the authors have worked to try to understand methods for improving the atomic beam polarized source. It seems interesting to consider whether the large ionization efficiency of an electron-cyclotron-resonance source could be maintained if such a source were used as an ionizer for the polarized atomic beam. An analysis of this application suggests that such an ECR ionizer might produce outgoing ion-beam intensities which are up to five times larger than those presently achieved with electron bombardment ionizers. Furthermore, the concern previously expressed that the ECR ionizer would cause resonant depolarization of the atomic beam before ionization seems unlikely

Polarized gas targets for storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1990-01-01

It is widely recognized that polarized gas targets in electron storage rings represent a new opportunity for precision nuclear physics studies. New developments in polarized target technology specific to internal applications will be discussed. In particular, polarized gas targets have been used in the VEPP-3 electron ring in Novosibirsk. A simple storage cell was used to increase the total target thickness by a factor of 15 over the simple gas jet target from an atomic beam source. Results from the initial phase of this project will be reported. In addition, the plans for increasing the luminosity by an additional order or magnitude will be presented. The application of this work to polarized hydrogen and deuterium targets for the HERA ring will be noted. The influence of beam-induced depolarization, a phenomena encountered in short-pulse electron storage rings, will be discussed. Finally, the performance tests of laser-driven sources will be presented. 8 refs., 12 figs., 1 tab

When measured spin polarization is not spin polarization

International Nuclear Information System (INIS)

Dowben, P A; Wu Ning; Binek, Christian

2011-01-01

Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO 2 and Cr 2 O 3 illustrate some of the complications which hinders comparisons of spin polarization values. (viewpoint)

Gender-heterogeneous working groups produce higher quality science.

Directory of Open Access Journals (Sweden)

Lesley G Campbell

Full Text Available Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index. While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.

Gender-heterogeneous working groups produce higher quality science.

Science.gov (United States)

Campbell, Lesley G; Mehtani, Siya; Dozier, Mary E; Rinehart, Janice

2013-01-01

Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index). While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.

Participation in Science Practices while Working in a Multimedia Case-Based Environment

Science.gov (United States)

Kang, Hosun; Lundeberg, Mary A.

2010-01-01

The purpose of this study was to investigate how two female students participated in science practices as they worked in a multimedia case-based environment: interpreting simulated results, reading and writing multiple texts, role-playing, and Internet conferencing. Using discourse analysis, the following data were analyzed: students' published…

Bringing Experience from the Field into the Classroom with the NOAA Teacher at Sea and PolarTREC Teacher Research Experience Programs

Science.gov (United States)

Eubanks, E. D.; Kohin, S.; Oberbauer, S.

2008-12-01

As a participant of the National Oceanic and Atmospheric Administration (NOAA), Teacher at Sea (2007) and the Arctic Research Consortium of the U.S., PolarTREC (2008) programs, I have had the opportunity to participate in hands-on research with leading scientific researchers from the tropics to the Arctic. These Teacher Researcher Experiences (TRE's) and the resulting relationships that have developed with the scientific community have been an asset to my professional development and have greatly enhanced my students' learning. The opportunity to participate in data collection and hands-on research with a NOAA researcher, Dr. Kohin, helped me bring shark, ocean, and ship science from my expedition onboard the NOAA Ship David Starr Jordan in the Channel Island region into my classroom. The new knowledge, experiences, and resources that I brought back allowed me to create lesson plans and host Shark Month--an activity that involved all 300 students in my school. My students were able to link real data regarding the location of sharks to practical application and still meet state standards. Likewise, the scientist from my PolarTREC expedition, Dr. Oberbauer, is assisting me in a long-term plan to incorporate his data into my classroom curricula. Already, my experiences from Barrow, Alaska, have been shared through webinars with my community and as a keynote speaker to over 600 Palm Beach County science teachers. We are also working together to develop a yearlong curriculum, in which my entire school of 300 students will discover interdisciplinary polar science. Participation in TRE's has been beneficial for my students and my community, but what is the return on the investment for the scientists who invited me to participate in their research? Both scientists have transferred their knowledge out of the laboratory and made a link between their research and a different generation--our future scientists. They become instrumental science leaders in a community of young

Fast, High-Precision Optical Polarization Synthesizer for Ultracold-Atom Experiments

Science.gov (United States)

Robens, Carsten; Brakhane, Stefan; Alt, Wolfgang; Meschede, Dieter; Zopes, Jonathan; Alberti, Andrea

2018-03-01

We present a technique for the precision synthesis of arbitrary polarization states of light with a high modulation bandwidth. Our approach consists of superimposing two laser light fields with the same wavelength, but with opposite circular polarizations, where the phase and the amplitude of each light field are individually controlled. We find that the polarization-synthesized beam reaches a degree of polarization of 99.99%, which is mainly limited by static spatial variations of the polarization state over the beam profile. We also find that the depolarization caused by temporal fluctuations of the polarization state is about 2 orders of magnitude smaller. In a recent work, Robens et al. [Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices, Phys. Rev. Lett. 118, 065302 (2017), 10.1103/PhysRevLett.118.065302] demonstrated an application of the polarization synthesizer to create two independently controllable optical lattices which trap atoms depending on their internal spin state. We use ultracold atoms in polarization-synthesized optical lattices to give an independent, in situ demonstration of the performance of the polarization synthesizer.

The Telemachus mission: dynamics of the polar sun and heliosphere

Science.gov (United States)

Roelof, E.

Telemachus in Greek mythology was the faithful son of Ulysses. The Telemachus mission is envisioned as the next logical step in the exploration of the polar regions of the Sun and heliosphere so excitingly initiated by the ESA/NASA Ulysses mission. Telemachus is a polar solar-heliospheric mission described in the current NASA Sun-Earth Connections Roadmap (2003-2028) that has successfully undergone two Team X studies by NASA/JPL. The pioneering observations from Ulysses transformed our perception of the structure and dynamics of these polar regions through which flow the solar wind, magnetic fields and energetic particles that eventually populate most of the volume of the heliosphere. Ulysses carried only fields and particles detectors. Telemachus, in addition to modern versions of such essential in situ instruments, will carry imagers that will give solar astronomers a new viewpoint on coronal mass ejections and solar flares, as well as their first purely polar views of the photospheric magnetic field, thereby providing new helioseismology to probe the interior of the Sun. Unlike the RTG-powered Ulysses, the power for Telemachus will come simply from solar panels. Gravity assist encounters with Venus and Earth (twice) will yield ˜5 years of continuous in-ecliptic cruise science between 0.7 AU and 3.3 AU that will powerfully complement other contemporary solar-heliospheric missions. The Jupiter gravity assist, followed by a perihelion burn ˜8 years after launch, will place Telemachus in a permanent ˜0.2 AU by 2.5 AU heliographic polar orbit (inclination >80 deg) whose period will be 1.5 years. Telemachus will then pass over the solar poles at ˜0.4 AU (compared to 1.4 AU for Ulysses) and spend ˜2 weeks above 60 deg on each polar pass (alternating perihelions between east and west limbs as viewed from Earth). In 14 polar passes during a 10.5 year solar cycle, Telemachus would accumulate over half a year of polar science data. During the remainder of the time, it

Spin dynamics in polarized neutron interferometry

International Nuclear Information System (INIS)

Buchelt, R.J.

2000-05-01

Since its first implementation in 1974, perfect crystal neutron interferometry has become an extremely successful method applicable to a variety of research fields. Moreover, it proved as an illustrative and didactically valuable experiment for the demonstration of the fundamental principles of quantum mechanics, the neutron being an almost ideal probe for the detection of various effects, as it interacts by all four forces of nature. For instance, the first experimental verification of the 4-pi-periodicity of spinor wave functions was performed with perfect crystal neutron interferometry, and it remains the only method known which demonstrates the quantum mechanical wave-particle-duality of massive particles at a macroscopic separation of the coherent matter waves of several centimeters. A particular position is taken herein by polarized neutron interferometry, which as a collective term comprises all techniques and experiments which not only aim at the coherent splitting and macroscopic separation of neutron beams in the interferometer with the purpose of their separate treatment, but which aim to do so with explicit employment of the spin-magnetic properties of the neutron as a fermion. Remarkable aspects may arise, for example, if nuclear and magnetic potentials are concurrently applied to a partial beam of the interferometer: among other results, it is found that - in perfect agreement to the theoretical predictions - the neutron beam leaving the interferometer features non-zero polarization, even if the incident neutron beam, and hence either of the partial beams, is unpolarized. The main emphasis of the present work lies on the development of an appropriate formalism that describes the effect of simultaneous occurrence of nuclear and magnetic interaction on the emerging intensity and polarization for an arbitrary number of sequential magnetic regions, so-called domains. The confrontation with subtle theoretical problems was inevitable during the experimental

[The CSI effect and its impact on the perceptions of forensic science experts' work].

Science.gov (United States)

Stojer, Joanna

2011-01-01

The issue that has been analyzed in this work is the potential effect of crime films and TV series on people's perceptions of forensic medicine and science, and especially on the forming of expectations towards forensic science experts. This syndrome is being called the "CSI effect" after the popular franchise Crime Scene Investigation (CSI). Questionnaire surveys that have been conducted included "experts": 50 experts in various specialities, 77 prosecutors, 119 judges, 64 lay judges, 161 police staff and 80 members of general public. In-depth interviews have been conducted with 20 police staff, and also a focus group has been carried out with 15 law students. In the opinion of the respondents, people's perceptions and expectations of forensic science--as it can be observed during criminal trials--are largely inflated by the entertainment media. Among the surveyed persons, the category that declares watching crime series most rarely, is forensic science experts. Around half of the surveyed experts pointed out to excessive expectations towards they work instigated by TV crime series. The most common expectations towards forensic medicine experts are: immediate conclusiveness of post mortem examinations (going as far as indicating the cause of death at the crime scene), precision of death time estimation and a routine use of sophisticated methods known from TV.

Atomically-resolved mapping of polarization and electric fields across ferroelectric-oxide interfaces by Z-contrast imaging

Science.gov (United States)

Borisevich, Albina; Chang, Hye Jung; Kalinin, Sergei; Morozovska, Anna; Chu, Ying-Hao; Yu, Pu; Ramesh, Ramamoorthy; Pennycook, Stephen

2011-03-01

Polarization, electric field, charge and potential across ferroelectric-oxide interfaces are obtained from direct atomic position mapping by aberration corrected scanning transmission electron microscopy combined with Ginsburg-Landau-Devonshire theory. We compare two antiparallel polarization orientations, which allows separation of the polarization and intrinsic interface charge contributions. Using the Born effective charges, the complete interface electrostatics is obtained in real space, providing an alternative method to holography. The results provide new microscopic insight into the thermodynamics of polarization distribution at the atomic level. Research is sponsored by the of Materials Sciences and Engineering Division, U.S. DOE.

Polar bears at risk

Energy Technology Data Exchange (ETDEWEB)

Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

2002-05-01

rains also destroy the denning habitat of ringed seals, the polar bears' primary prey. Declines in the ringed seal population would mean a loss of food for polar bears. A trend toward stronger winds and increasing ice drift observed in some parts of the Arctic over the last five decades will likely increase energy expenditures and stress levels in polar bears that spend most of their lives on drifting sea ice. Polar bears face other limiting factors as well. Historically, the main threat to polar bears has been hunting. Satisfactory monitoring information has been obtained for most polar bear populations in recent years, however there is concern about hunting in areas without formal quota systems, such as Greenland. A range of toxic pollutants, including heavy metals, radioactivity, and persistent organic pollutants (POPs) are found throughout the Arctic. Of greatest concern are the effects of POPs on polar bears, which include a general weakening of the immune system, reduced reproductive success and physical deformities. The expansion of oil development in the Arctic poses additional threats; for example, disturbances to denning females in the Arctic National Wildlife Refuge in Alaska could undermine recruitment of the Beaufort Sea polar bear population. These threats, along with other effects of human activity in the Arctic, combine to pressure polar bears and their habitat. Large carnivores are sensitive indicators of ecosystem health and can be used to define the minimum area necessary to preserve intact ecosystems. WWF has identified the polar bear as a unique symbol of the complexities and interdependencies of the arctic marine ecosystem as it works toward its goal of preserving biodiversity for future generations.

Chip-based microtrap arrays for cold polar molecules

Science.gov (United States)

Hou, Shunyong; Wei, Bin; Deng, Lianzhong; Yin, Jianping

2017-12-01

Compared to the atomic chip, which has been a powerful platform to perform an astonishing range of applications from rapid Bose-Einstein condensate (BEC) production to the atomic clock, the molecular chip is only in its infant stages. Recently a one-dimensional electric lattice was demonstrated to trap polar molecules on a chip. This excellent work opens up the way to building a molecular chip laboratory. Here we propose a two-dimensional (2D) electric lattice on a chip with concise and robust structure, which is formed by arrays of squared gold wires. Arrays of microtraps that originate in the microsize electrodes offer a steep gradient and thus allow for confining both light and heavy polar molecules. Theoretical analysis and numerical calculations are performed using two types of sample molecules, N D3 and SrF, to justify the possibility of our proposal. The height of the minima of the potential wells is about 10 μm above the surface of the chip and can be easily adjusted in a wide range by changing the voltages applied on the electrodes. These microtraps offer intriguing perspectives for investigating cold molecules in periodic potentials, such as quantum computing science, low-dimensional physics, and some other possible applications amenable to magnetic or optical lattice. The 2D adjustable electric lattice is expected to act as a building block for a future gas-phase molecular chip laboratory.

Research on generating various polarization-modes in polarized illumination system

Science.gov (United States)

Huang, Jinping; Lin, Wumei; Fan, Zhenjie

2013-08-01

With the increase of the numerical aperture (NA), the polarization of light affects the imaging quality of projection lens more significantly. On the contrary, according to the mask pattern, the resolution of projection lens can be improved by using the polarized illumination. That is to say, using the corresponding polarized beam (or polarization-mode) along with the off-axis illumination will improve the resolution and the imaging quality of the of projection lens. Therefore, the research on the generation of various polarization modes and its conversion methods become more and more important. In order to realize various polarization modes in polarized illumination system, after read a lot of references, we provide a way that fitting for the illumination system with the wavelength of 193nm.Six polarization-modes and a depolarized mode are probably considered. Wave-plate stack is used to generate linearly polarization-mode, which have a higher degree polarization. In order to generate X-Y and Y-X polarization mode, the equipment consisting of four sectors of λ/2 wave plate was used. We combined 16 sectors of λ/2 wave plate which have different orientations of the "slow" axis to generate radial and azimuthal polarization. Finally, a multi-polarization control device was designed. Using the kind of multi-polarization control device which applying this method could help to choose the polarization modes conveniently and flexibility for the illumination system.

Myth polar light. Why sky bands, herring lightnings, and solar winds fascinate; Mythos Polarlicht. Warum Himmelsbaender, Heringsblitze und Sonnenwinde faszinieren

Energy Technology Data Exchange (ETDEWEB)

Hunnekuhl, Michael

2014-07-01

The actual state of knowledge of the polar-light research is in this illustrated volume as entertainingly as scientific-foundedly presented. The pecularities of pola lights beyond the polar-light zones as for instance in Germany are thematized and the conditions and periods, in which it there occurs, explained. Michael Hunnekuhl succeeds to mediate the fascination and emotion and simultaneously to explain the phenomena according to the latest state of science generally understandably. Which very old interpretations and descriptions are transmitted, which imaginations had men of polar lights long before the science could them explain? Hunnekuhl takes the reader along with into the world of legends and myths around the polar light. An experience report from the deeply snowed up wideness of Lapland lets everybody closely participate at a polar-light observation and feel the emotion, which it can fan. Above 70 polar-light pictures of high value and further explaining graphics show the continuously changing play of colors, supplement the explanations, and make the fascination comprehensible. Spectacular polar-light films from the international space station ISS, photographs from sun-observation satellites, as well as a polar-light film in real time are bound in the book via QR codes and make the time dimension and the dynamics of this fascinating natural spectacle alively comprehensible.

Polarization properties of linearly polarized parabolic scaling Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Guo, Mengwen; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

2016-10-07

The intensity profiles for the dominant polarization, cross polarization, and longitudinal components of modified parabolic scaling Bessel beams with linear polarization are investigated theoretically. The transverse intensity distributions of the three electric components are intimately connected to the topological charge. In particular, the intensity patterns of the cross polarization and longitudinal components near the apodization plane reflect the sign of the topological charge. - Highlights: • We investigated the polarization properties of modified parabolic scaling Bessel beams with linear polarization. • We studied the evolution of transverse intensity profiles for the three components of these beams. • The intensity patterns of the cross polarization and longitudinal components can reflect the sign of the topological charge.

Dual-band high-efficiency polarization converter using an anisotropic metasurface

Science.gov (United States)

Lin, Baoqin; Wang, Buhong; Meng, Wen; Da, Xinyu; Li, Wei; Fang, Yingwu; Zhu, Zihang

2016-05-01

In this work, a dual-band and high-efficiency reflective cross-polarization converter based on an anisotropic metasurface for linearly polarized electromagnetic waves is proposed. Its unit cell is composed of an elliptical disk-ring mounted on grounded dielectric substrate, which is an anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along ± 45 ° directions with respect to y-axis direction. Both the simulation and measured results show that the polarization converter can convert x- or y-polarized incident wave to its cross polarized wave in the two frequency bands (6.99-9.18 GHz, 11.66-20.40 GHz) with the conversion efficiency higher than 90%; moreover, the higher frequency band is an ultra-wide one with a relative bandwidth of 54.5% for multiple plasmon resonances. In addition, we present a detailed analysis for the polarization conversion of the polarization converter, and derive a formula to calculate the cross- and co-polarization reflections at y-polarized incidence according to the phase differences between the two reflected coefficients at u-polarized and v-polarized incidences. The simulated, calculated, and measured results are all in agreement with the entire frequency regions.

On gestation periods of creative work: an interface of Doig's art and science.

Science.gov (United States)

Erren, Thomas C

2010-01-01

This article is meant for, but not confined to, younger scientists who may have a series of ideas, hypotheses and projects--be they small or big--and might grapple with the objective to pursue and complete at least some, and preferably most, work in due course. And yet, the very generation, development and completion of numerous projects takes gestation periods which can be long and painful. Importantly, this simple but important truth is valid for any creative process, be it in the sciences or in the arts. With reference to luminaries like Max Perutz and George Wald, more general interfaces between science and the arts are identified. With reference to how some of Peter Doig's paintings evolve over long times and to how John Eccles and Isaac Newton worked, extended gestation periods as a key similarity of creative work by both artists and scientists are exemplified and vindicated. It is concluded that long gestation periods of creative work should be viewed as the expectation rather than the exception. Importantly, the evolutionary and somewhat intuitive commitment to several projects at the same, and often extended, periods of time can be a recipe for revolutionary results fostered by the required variation and diversity of thinking and cross-fertilization of--seemingly--unrelated themes and fields.

La nouvelle vague in polarized neutron scattering

International Nuclear Information System (INIS)

Mezei, F.

1986-01-01

Polarized neutron research, like many other subjects in neutron scattering developed in the footsteps of Cliff Shull. The classical polarized neutron technique he pioneered was generalized around 1970 to vectorial beam polarizations and this opened up the way to a ''nouvelle vague'' of neutron scattering experiments. In this paper I will first reexamine the old controversy on the question whether the nature of the neutron magnetic moment is that of a microscopic dipole or of an Amperian current loop. The problem is not only of historical interest, but also of relevance to modern applications. This will be followed by a review of the fundamentals on spin coherence effects in neutron beams and scattering, which are the basis of vectorial beam polarization work. As an example of practical importance, paramagnetic scattering will be discussed. The paper concludes with some examples of applications of the vector polarization techniques, such as study of ferromagnetic domains by neutron beam depolarization and Neutron Spin Echo high resolution inelastic spectroscopy. The sample results presented demonstrate the new opportunities this novel approach opened up in neutrons scattering research. (orig.)

Metal membrane with dimer slots as a universal polarizer

DEFF Research Database (Denmark)

Zhukovsky, Sergei; Zalkovskij, Maksim; Malureanu, Radu

2014-01-01

In this work, we show theoretically and confirm experimentally that thin metal membranes patterned with an array of slot dimers (or their Babinet analogue with metal rods) can function as a versatile spectral and polarization filter. We present a detailed covariant multipole theory for the electr......In this work, we show theoretically and confirm experimentally that thin metal membranes patterned with an array of slot dimers (or their Babinet analogue with metal rods) can function as a versatile spectral and polarization filter. We present a detailed covariant multipole theory...

Polarized nuclear target based on parahydrogen induced polarization

OpenAIRE

Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

2012-01-01

We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.

Development of a medium energy polarized neutron facility

International Nuclear Information System (INIS)

Burzynski, S.; Gysin, C.; Henneck, R.; Jourdan, J.; Kohler, D.; Pickar, M.A.; Plattner, G.R.; Sick, I.; Berdoz, A.; Foroughi, F.; Nussbaum, Ch.; Stammbach, Th.

1984-01-01

By the end of 1983 the major construction work for the new polarized neutron source was completed. The source will provide an essentially monoenergetic beam of both polarized and unpolarized neutrons in the energy range from 20 MeV to 70 MeV. Intensities are expected to be approx. 2 x 10 5 neutrons/s.cm 2 per μA of incident proton beam. The polarization is expected to be approx. 0.2 and can be chosen to be either longitudinal or transverse. Protons from the Philips injector cyclotron are focussed onto a liquid deuterium target and produce neutrons via the 2 H(p,n)2p reaction at 0 0 . This process provides essentially monoenergetic neutrons of almost the same energy as the incoming protons. The zero production angle implies that the neutron polarization comes from the polarization of the proton beam only. This allows an easy and fast change of the neutron spin direction by selecting proton spin states in the polarized ion source (atomic beam type). (Auth.)

A Novel Attitude Determination System Aided by Polarization Sensor

Directory of Open Access Journals (Sweden)

Wei Zhi

2018-01-01

Full Text Available This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle.

A Novel Attitude Determination System Aided by Polarization Sensor.

Science.gov (United States)

Zhi, Wei; Chu, Jinkui; Li, Jinshan; Wang, Yinlong

2018-01-09

This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF) with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV) flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle.

Energy transport, polar amplification, and ITCZ shifts in the GeoMIP G1 ensemble

Directory of Open Access Journals (Sweden)

R. D. Russotto

2018-02-01

Full Text Available The polar amplification of warming and the ability of the Intertropical Convergence Zone (ITCZ to shift to the north or south are two very important problems in climate science. Examining these behaviors in global climate models (GCMs running solar geoengineering experiments is helpful not only for predicting the effects of solar geoengineering but also for understanding how these processes work under increased carbon dioxide (CO2. Both polar amplification and ITCZ shifts are closely related to the meridional transport of moist static energy (MSE by the atmosphere. This study examines changes in MSE transport in 10 fully coupled GCMs in experiment G1 of the Geoengineering Model Intercomparison Project (GeoMIP, in which the solar constant is reduced to compensate for the radiative forcing from abruptly quadrupled CO2 concentrations. In G1, poleward MSE transport decreases relative to preindustrial conditions in all models, in contrast to the Coupled Model Intercomparison Project phase 5 (CMIP5 abrupt4xCO2 experiment, in which poleward MSE transport increases. We show that since poleward energy transport decreases rather than increases, and local feedbacks cannot change the sign of an initial temperature change, the residual polar amplification in the G1 experiment must be due to the net positive forcing in the polar regions and net negative forcing in the tropics, which arise from the different spatial patterns of the simultaneously imposed solar and CO2 forcings. However, the reduction in poleward energy transport likely plays a role in limiting the polar warming in G1. An attribution study with a moist energy balance model shows that cloud feedbacks are the largest source of uncertainty regarding changes in poleward energy transport in midlatitudes in G1, as well as for changes in cross-equatorial energy transport, which are anticorrelated with ITCZ shifts.

Incorporating the International Polar Year Into Introductory Geology Laboratories at Ohio State University

Science.gov (United States)

Judge, S. A.; Wilson, T. J.

2005-12-01

The International Polar Year (IPY) provides an excellent opportunity for highlighting polar research in education. The ultimate goal of our outreach and education program is to develop a series of modules that are focused on societally-relevant topics being investigated in Antarctic earth science, while teaching basic geologic concepts that are standard elements of school curricula. For example, we envision a university-level, undergraduate, introductory earth science class with the entire semester/quarter laboratory program focused on polar earth science research during the period of the International Polar Year. To attain this goal, a series of modules will be developed, including inquiry-based exercises founded on imagery (video, digital photos, digital core scans), GIS data layers, maps, and data sets available from OSU research groups. Modules that highlight polar research are also suitable for the K-12 audience. Scaleable/grade appropriate modules that use some of the same data sets as the undergraduate modules can be outlined for elementary through high school earth science classes. An initial module is being developed that focuses on paleoclimate data. The module provides a hands-on investigation of the climate history archived in both ice cores and sedimentary rock cores in order to understand time scales, drivers, and processes of global climate change. The paleoclimate module also demonstrates the types of polar research that are ongoing at OSU, allowing students to observe what research the faculty are undertaking in their respective fields. This will link faculty research with student education in the classroom, enhancing learning outcomes. Finally, this module will provide a direct link to U.S. Antarctic Program research related to the International Polar Year, when new ice and sedimentary rock cores will be obtained and analyzed. As a result of this laboratory exercise, the students will be able to: (1) Define an ice core and a sedimentary rock core

Development of high-polarization Fe/Ge neutron polarizing supermirror: Possibility of fine-tuning of scattering length density in ion beam sputtering

Science.gov (United States)

Maruyama, R.; Yamazaki, D.; Akutsu, K.; Hanashima, T.; Miyata, N.; Aoki, H.; Takeda, M.; Soyama, K.

2018-04-01

The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. Bundesmann et al. (2015) have shown that the implantation of primary Ar ions backscattered at the target is responsible for the incorporation of Ar particles and that the fraction increases with increasing ion incidence angle and increasing polar emission angle. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with m = 5 fabricated under the same condition showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the qz range where the correction for the polarization inefficiencies of the beamline works properly. The result of the polarized neutron reflectivity measurement suggests that the "magnetically-dead" layers formed at both sides of the Fe layer, together with the SLD contrast, play a critical role in determining the polarization performance of a polarizing supermirror.

Space Solar Power Technology for Lunar Polar Applications

Science.gov (United States)

Henley, Mark W.; Howell, Joe T.

2004-01-01

The technology for Laser-Photo-Voltaic Wireless Power Transistor (Laser-PV WPT) is being developed for lunar polar applications by Boeing and NASA Marshall Space Center. A lunar polar mission could demonstrate and validate Laser-PV WPT and other SSP technologies, while enabling access to cold, permanently shadowed craters that are believed to contain ice. Crater may hold frozen water and other volatiles deposited over billion of years, recording prior impact event on the moon (and Earth). A photo-voltaic-powered rover could use sunlight, when available, and laser light, when required, to explore a wide range of lunar terrain. The National Research Council recently found that a mission to the moon's south pole-Aitkir basin has priority for space science

Chairmanship of the Neptune/Pluto outer planets science working group

Science.gov (United States)

Stern, S. Alan

1993-11-01

The Outer Planets Science Working Group (OPSWG) is the NASA Solar System Exploration Division (SSED) scientific steering committee for the Outer Solar System missions. OPSWG consists of 19 members and is chaired by Dr. S. Alan Stern. This proposal summarizes the FY93 activities of OPSWG, describes a set of objectives for OPSWG in FY94, and outlines the SWG's activities for FY95. As chair of OPSWG, Dr. Stern will be responsible for: organizing priorities, setting agendas, conducting meetings of the Outer Planets SWG; reporting the results of OPSWG's work to SSED; supporting those activities relating to OPSWG work, such as briefings to the SSES, COMPLEX, and OSS; supporting the JPL/SAIC Pluto study team; and other tasks requested by SSED. As the Scientific Working Group (SWG) for Jupiter and the planets beyond, OPSWG is the SSED SWG chartered to study and develop mission plans for all missions to the giant planets, Pluto, and other distant objects in the remote outer solar system. In that role, OPSWG is responsible for: defining and prioritizing scientific objectives for missions to these bodies; defining and documenting the scientific goals and rationale behind such missions; defining and prioritizing the datasets to be obtained in these missions; defining and prioritizing measurement objectives for these missions; defining and documenting the scientific rationale for strawman instrument payloads; defining and prioritizing the scientific requirements for orbital tour and flyby encounter trajectories; defining cruise science opportunities plan; providing technical feedback to JPL and SSED on the scientific capabilities of engineering studies for these missions; providing documentation to SSED concerning the scientific goals, objectives, and rationale for the mission; interfacing with other SSED and OSS committees at the request of SSED's Director or those committee chairs; providing input to SSED concerning the structure and content of the Announcement of Opportunity

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.

Fusion of a polarized projectile with a polarized target

International Nuclear Information System (INIS)

Christley, J.A.; Johnson, R.C.; Thompson, I.J.

1995-01-01

The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

A polarized {sup 3}He target for the photon beam at MAMI

Energy Technology Data Exchange (ETDEWEB)

Krimmer, J., E-mail: j.krimmer@ipnl.in2p3.fr [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Institut de Physique Nucleaire de Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne cedex (France); Aguar Bartolome, P.; Ahrens, J. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany); Altieri, S. [INFN Sezione di Pavia, Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, Pavia (Italy); Arends, H.J. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany); Heil, W.; Karpuk, S.; Otten, E.W. [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Pedroni, P. [INFN Sezione di Pavia, Pavia (Italy); Salhi, Z. [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Thomas, A. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany)

2011-08-21

A polarized {sup 3}He target has been installed for the first time inside the 4{pi} Crystal Ball detector at the tagged photon beam of the MAinz MIcrotron (MAMI). It has been demonstrated that the system works reliably and that the polarization losses during handling of the polarized gas are under control. Initial polarization values up to 70% and total relaxation times up to 20 h could be obtained during a first test beam time devoted to the measurement of the double polarized photoabsorption cross-section in the {Delta}(1232) baryon resonance region.

Numerical modeling of polar mesocyclones generation mechanisms

Science.gov (United States)

Sergeev, Dennis; Stepanenko, Victor

2013-04-01

parameters, lateral boundary conditions are varied in the typically observed range. The approach is fully nonlinear: we use a three-dimensional non-hydrostatic mesoscale model NH3D_MPI [1] coupled with one-dimensional water body model LAKE. A key method used in the present study is the analysis of eddy kinetic and available potential energy budgets. References 1. Mikushin, D.N., and Stepanenko, V.M., The implementation of regional atmospheric model numerical algorithms for CBEA-based clusters. Lecture Notes in Computer Science, Parallel Processing and Applied Mathematics, 2010, vol. 6067, p. 525-534. 2. Rasmussen, E., and Turner, J. (eds), Polar Lows: Mesoscale Weather Systems in the Polar Regions. Cambridge: Cambridge University Press, 2003, 612 pp. 3. Yanase, W., and Niino, H., Dependence of Polar Low Development on Baroclinicity and Physical Processes: An Idealized High-Resolution Experiment, J. Atmos. Sci., 2006, vol. 64, p. 3044-3067.

Cool Science Explains a Warming World: Using Ice Core Science to Bridge the Gap Between Researchers and the K-12 Classroom

Science.gov (United States)

Huffman, L. T.

2017-12-01

Changing ice has urgent implications for people around the world. The Ice Drilling Program Office (IDPO) provides scientific leadership and oversight of ice coring and drilling activities funded by the US National Science Foundation and also has goals to enhance education and communication of current research information. In a time when misinformation is rampant and climate change science is suspect, it is essential that students receive accurate scientific information and engage in learning activities that model complex ideas through engaging and age appropriate ways, while also learning to validate and recognize reliable sources. The IDPO Education and Outreach (EO) office works to create resources, activities and professional development that bridge the gap between ice core science research and educators and their students. Ice core science is on the cutting edge of new discoveries about climate change and understanding better the past to predict the future. Hands-on inquiry activities based on ice core data allow teachers to lead their students to new discoveries about climate secrets hidden deep in the ice. Capitalizing on the inherent interest in the extremes of the Polar Regions, IDPO materials engage students in activities aligned with NGSS standards. Ice drilling technologies make an ideal platform for intertwining engineering concepts and practices with science research to meet the SEP (Science and Engineering Practices) in the NGSS. This session will highlight how the IDPO EO office has built a community of ice core scientists willing to take part in education and outreach projects and events and share some of the resources available to K-12 educators. We will highlight some of the successes and lessons learned as we continually evolve our work toward more effective science education and communication highlighting ice core and climate change science.

On the Wiener Polarity Index of Lattice Networks.

Science.gov (United States)

Chen, Lin; Li, Tao; Liu, Jinfeng; Shi, Yongtang; Wang, Hua

2016-01-01

Network structures are everywhere, including but not limited to applications in biological, physical and social sciences, information technology, and optimization. Network robustness is of crucial importance in all such applications. Research on this topic relies on finding a suitable measure and use this measure to quantify network robustness. A number of distance-based graph invariants, also known as topological indices, have recently been incorporated as descriptors of complex networks. Among them the Wiener type indices are the most well known and commonly used such descriptors. As one of the fundamental variants of the original Wiener index, the Wiener polarity index has been introduced for a long time and known to be related to the cluster coefficient of networks. In this paper, we consider the value of the Wiener polarity index of lattice networks, a common network structure known for its simplicity and symmetric structure. We first present a simple general formula for computing the Wiener polarity index of any graph. Using this formula, together with the symmetric and recursive topology of lattice networks, we provide explicit formulas of the Wiener polarity index of the square lattices, the hexagonal lattices, the triangular lattices, and the 33 ⋅ 42 lattices. We also comment on potential future research topics.

Polarity: The theology of anti-Judaism in Ephrem the Syrian's hymns ...

African Journals Online (AJOL)

century Syrian theologian Ephrem is investigated. This polarity is found to be polemical against the Jews. But since polarity is a constant feature in the work of Ephrem which serves to communicate his theological frame of mind, the question is ...

DETECTING CHANGING POLARIZATION STRUCTURES IN SAGITTARIUS A* WITH HIGH FREQUENCY VLBI

International Nuclear Information System (INIS)

Fish, Vincent L.; Doeleman, Sheperd S.; Rogers, Alan E. E.; Broderick, Avery E.; Loeb, Abraham

2009-01-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to 6 M sun black hole. In previous work, we demonstrated the potential for total-intensity (sub)millimeter-wavelength very long baseline interferometry (VLBI) to detect time-variable-and periodic-source structure changes in the Sgr A* black hole system using nonimaging analyses. Here, we extend this work to include full polarimetric VLBI observations. We simulate full-polarization (sub)millimeter VLBI data of Sgr A* using a hot spot model that is embedded within an accretion disk, with emphasis on nonimaging polarimetric data products that are robust against calibration errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

DETECTING CHANGING POLARIZATION STRUCTURES IN SAGITTARIUS A* WITH HIGH FREQUENCY VLBI

Energy Technology Data Exchange (ETDEWEB)

Fish, Vincent L; Doeleman, Sheperd S; Rogers, Alan E. E. [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Loeb, Abraham [Institute for Theory and Computation, Harvard University, Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2009-12-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to <10 Schwarzschild radii of the presumed 4 x 10{sup 6} M {sub sun} black hole. In previous work, we demonstrated the potential for total-intensity (sub)millimeter-wavelength very long baseline interferometry (VLBI) to detect time-variable-and periodic-source structure changes in the Sgr A* black hole system using nonimaging analyses. Here, we extend this work to include full polarimetric VLBI observations. We simulate full-polarization (sub)millimeter VLBI data of Sgr A* using a hot spot model that is embedded within an accretion disk, with emphasis on nonimaging polarimetric data products that are robust against calibration errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

Young Researchers Engaged in Educational Outreach to Increase Polar Literacy

Science.gov (United States)

Raymond, M.; Baeseman, J.; Xavier, J.; Kaiser, B.; Vendrell-Simon, B.

2008-12-01

The Association of Polar Early Career Scientists (APECS) grew out of the 4th International Polar Year (IPY-4) 2007-08 and is an international and interdisciplinary organization of over 1200 undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and others with interests in Polar Regions and the wider cryosphere from more than 40 countries. Our aims are to stimulate interdisciplinary and international research collaborations, and develop effective future leaders in polar research, education and outreach. As potentially one of the major legacies of IPY-4, APECS members have been at the forefront of increasing scientific knowledge and public interest in the polar regions, centered around global climate change, and enhancing scientific understanding, media attention, primary and secondary school (K-12) educational programs, undergraduate institutions, and public literacy campaigns. Research and Educational Outreach activities by APECS members during IPY-4 have improved both our understanding and the communication of all aspects of the Polar Regions and the importance of their broader global connections. APECS National Committees have run Polar Contests where young researchers partnered with teachers and students to develop curriculum and activities to share their research, have participated in many field based communication exchanges and are mentoring youth to pursue careers in science, and enhancing the public perception of scientists through photo, video and museum exhibits. In cooperation with the IPY Teachers Network and the IPY IPO, APECS is developing a polar education resource book that will feature education and outreach activities by young researchers, as well as provide examples of classroom activities for teachers to incorporate polar literacy into their curriculum and a How-To guide for researchers interested in conducting education and outreach. As young researchers interactively share their excitement and

Lateral polarity control of III-nitride thin film and application in GaN Schottky barrier diode

Science.gov (United States)

Li, Junmei; Guo, Wei; Sheikhi, Moheb; Li, Hongwei; Bo, Baoxue; Ye, Jichun

2018-05-01

N-polar and III-polar GaN and AlN epitaxial thin films grown side by side on single sapphire substrate was reported. Surface morphology, wet etching susceptibility and bi-axial strain conditions were investigated and the polarity control scheme was utilized in the fabrication of Schottky barrier diode where ohmic contact and Schottky contact were deposited on N-polar domains and Ga-polar domains, respectively. The influence of N-polarity on on-state resistivity and I–V characteristic was discussed, demonstrating that lateral polarity structure of GaN and AlN can be widely used in new designs of optoelectronic and electronic devices. Project partially supported by the National Key Research and Development Program of China (No. 2016YFB0400802), the National Natural Science Foundation of China (No. 61704176), and the Open project of Zhejiang Key Laboratory for Advanced Microelectronic Intelligent Systems and Applications (No. ZJUAMIS1704).

Design technique for all-dielectric non-polarizing beam splitter plate

Science.gov (United States)

Rizea, A.

2012-03-01

There are many situations when, for the proper working, an opto-electronic device requiring optical components does not change the polarization state of light after a reflection, splitting or filtering. In this paper, a design for a non-polarizing beam splitter plate is proposed. Based on certain optical properties of homogeneous dielectric materials we will establish a reliable thin film package formula, excellent for the start of optimization to obtain a 20-nm bandwidth non-polarizing beam splitter.

Scattering of polarized low-energy electrons by ferromagnetic metals

International Nuclear Information System (INIS)

Helman, J.S.

1981-01-01

A source of spin polarized electrons with remarkable characteristics based on negative electron affinity (NEA) GaAs has recently been developed. It constitutes a unique tool to investigate spin dependent interactions in electron scattering processes. The characteristics and working principles of the source are briefly described. Some theoretical aspects of the scattering of polarized low-energy electrons by ferromagnetic metals are discussed. Finally, the results of the first polarized low-energy electron diffraction experiment using the NEA GaAs source are reviewed; they give information about the surface magnetization of ferromagnetic Ni (110). (Author) [pt

New material equations for electromagnetism with toroid polarizations

International Nuclear Information System (INIS)

Dubovik, V.M.; Martsenyuk, M.A.; Saha, B.

1999-09-01

With regard to the toroid contributions, a modified system of equations of electrodynamics moving continuous media has been obtained. Alternative formalisms to introduce the toroid moment contributions in the equations of electromagnetism has been worked out. The two four-potential formalism has been developed. Lorentz transformation laws for the toroid polarizations has been given. Covariant form of equations of electrodynamics of continuous media with toroid polarizations has been written. (author)

Work and family conflict in academic science: patterns and predictors among women and men in research universities.

Science.gov (United States)

Fox, Mary Frank; Fonseca, Carolyn; Bao, Jinghui

2011-10-01

This article addresses work-family conflict as reported among women and men academic scientists in data systematically collected across fields of study in nine US research universities. Arguing that academic science is a particularly revealing case for studying work-family conflict, the article addresses: (1) the bi-directional conflict of work with family, and family with work, reported among the scientists; (2) the ways that higher, compared with lower, conflict, is predicted by key features of family, academic rank, and departments/institutions; and (3) patterns and predictors of work-family conflict that vary, as well as converge, by gender. Results point to notable differences, and commonalties, by gender, in factors affecting interference in both directions of work-family conflict reported by scientists. These findings have implications for understandings of how marriage and children, senior compared with junior academic rank, and departmental climates shape work-family conflict among women and men in US academic science.

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2)

Science.gov (United States)

Wohltmann, Ingo; Lehmann, Ralph; Rex, Markus

2017-07-01

The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx), HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect caused by the

High precision neutron polarization for PERC

International Nuclear Information System (INIS)

Klauser, C.

2013-01-01

The decay of the free neutron into a proton, an electron and an anti-electron neutrino offers a simple system to study the semi-leptonic weak decay. High precision measurements of angular correlation coefficients of this decay provide the opportunity to test the standard model on the low energy frontier. The Proton Electron Radiation Channel PERC is part of a new generation of expriments pushing the accuracy of such an angular correlation coefficient measurement towards 10 -4 . Past experiments have been limited to an accuracy of 10 -3 with uncertainties on the neutron polarization as one of the leading systematic errors. This thesis focuses on the development of a stable, highly precise neutron polarization for a large, divergent cold neutron beam. A diagnostic tool that provides polarization higher than 99.99 % and analyzes with an accuracy of 10 -4 , the Opaque Test Bench, is presented and validated. It consists of two highly opaque polarized helium cells. The Opaque Test Bench reveals depolarizing effects in polarizing supermirrors commonly used for polarization in neutron decay experiments. These effects are investigated in detail. They are due to imperfect lateral magnetization in supermirror layers and can be minimized by significantly increased magnetizing fields and low incidence angle and supermirror factor m. A subsequent test in the crossed (X-SM) geometry demonstrated polarizations up to 99.97% from supermirrors only, improving neutron polarization with supermirrors by an order of magnitude. The thesis also discusses other neutron optical components of the PERC beamline: Monte-Carlo simulations of the beamline under consideration of the primary guide are carried out. In addition, calculation shows that PERC would statistically profit from an installation at the European Spallation source. Furthermore, beamline components were tested. A radio-frequency spin flipper was confirmed to work with an efficiency higher than 0.9999. (author) [de

Thermal analysis of a prototype cryogenic polarization modulator for use in a space-borne CMB polarization experiment

Science.gov (United States)

Iida, T.; Sakurai, Y.; Matsumura, T.; Sugai, H.; Imada, H.; Kataza, H.; Ohsaki, H.; Hazumi, M.; Katayama, N.; Yamamoto, R.; Utsunomiya, S.; Terao, Y.

2017-12-01

We report a thermal analysis of a polarization modulator unit (PMU) for use in a space-borne cosmic microwave background (CMB) project. A measurement of the CMB polarization allows us to probe the physics of early universe, and that is the best method to test the cosmic inflation experimentally. One of the key instruments for this science is to use a halfwave plate (HWP) based polarization modulator. The HWP is required to rotate continuously at about 1 Hz below 10 K to minimize its own thermal emission to a detector system. The rotating HWP system at the cryogenic environment can be realized by using a superconducting magnetic bearing (SMB) without significant heat dissipation by mechanical friction. While the SMB achieves the smooth rotation due to the contactless bearing, an estimation of a levitating HWP temperature becomes a challenge. We manufactured a one-eighth scale prototype model of PMU and built a thermal model. We verified our thermal model with the experimental data. We forecasted the projected thermal performance of PMU for a full-scale model based on the thermal model. From this analysis, we discuss the design requirement toward constructing the full-scale model for use in a space environment such as a future CMB satellite mission, LiteBIRD.

Polarised light in science and nature

CERN Document Server

Pye, J David

2001-01-01

We humans cannot see when light is polarized and this leads to unfortunate misapprehensions about this aspect of nature. Even scientists who should know better often assume that it is an obscure topic of specialized interest in only a few rather isolated areas. In fact, it is a universal feature of our world and most natural light is at least partially polarized. In the animal kingdom, insects and other animals exploit such natural polarization in some fascinating ways since they do not share this human deficiency and can both detect and analyze polarization. It may be our unfamiliarity with this aspect of light that also makes people think it is a difficult subject, yet the basis is extremely simple. When these misconceptions are overcome, the phenomena associated with polarization are found to be important throughout science and technology, from physics, astronomy, natural history, geology, chemistry, and several branches of engineering to crafts such as glass-blowing and jewelry. Polarized light also invol...

Neutron polarization

International Nuclear Information System (INIS)

Firk, F.W.K.

1976-01-01

Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

Second-harmonic generation in shear wave beams with different polarizations

Science.gov (United States)

Spratt, Kyle S.; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F.

2015-10-01

A coupled pair of nonlinear parabolic equations was derived by Zabolotskaya [1] that model the transverse components of the particle motion in a collimated shear wave beam propagating in an isotropic elastic solid. Like the KZK equation, the parabolic equation for shear wave beams accounts consistently for the leading order effects of diffraction, viscosity and nonlinearity. The nonlinearity includes a cubic nonlinear term that is equivalent to that present in plane shear waves, as well as a quadratic nonlinear term that is unique to diffracting beams. The work by Wochner et al. [2] considered shear wave beams with translational polarizations (linear, circular and elliptical), wherein second-order nonlinear effects vanish and the leading order nonlinear effect is third-harmonic generation by the cubic nonlinearity. The purpose of the current work is to investigate the quadratic nonlinear term present in the parabolic equation for shear wave beams by considering second-harmonic generation in Gaussian beams as a second-order nonlinear effect using standard perturbation theory. In order for second-order nonlinear effects to be present, a broader class of source polarizations must be considered that includes not only the familiar translational polarizations, but also polarizations accounting for stretching, shearing and rotation of the source plane. It is found that the polarization of the second harmonic generated by the quadratic nonlinearity is not necessarily the same as the polarization of the source-frequency beam, and we are able to derive a general analytic solution for second-harmonic generation from a Gaussian source condition that gives explicitly the relationship between the polarization of the source-frequency beam and the polarization of the second harmonic.

Second-harmonic generation in shear wave beams with different polarizations

Energy Technology Data Exchange (ETDEWEB)

Spratt, Kyle S., E-mail: sprattkyle@gmail.com; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F. [Applied Research Laboratories, The University of Texas at Austin, P. O. Box 8029, Austin, Texas 78713–8029, US (United States)

2015-10-28

A coupled pair of nonlinear parabolic equations was derived by Zabolotskaya [1] that model the transverse components of the particle motion in a collimated shear wave beam propagating in an isotropic elastic solid. Like the KZK equation, the parabolic equation for shear wave beams accounts consistently for the leading order effects of diffraction, viscosity and nonlinearity. The nonlinearity includes a cubic nonlinear term that is equivalent to that present in plane shear waves, as well as a quadratic nonlinear term that is unique to diffracting beams. The work by Wochner et al. [2] considered shear wave beams with translational polarizations (linear, circular and elliptical), wherein second-order nonlinear effects vanish and the leading order nonlinear effect is third-harmonic generation by the cubic nonlinearity. The purpose of the current work is to investigate the quadratic nonlinear term present in the parabolic equation for shear wave beams by considering second-harmonic generation in Gaussian beams as a second-order nonlinear effect using standard perturbation theory. In order for second-order nonlinear effects to be present, a broader class of source polarizations must be considered that includes not only the familiar translational polarizations, but also polarizations accounting for stretching, shearing and rotation of the source plane. It is found that the polarization of the second harmonic generated by the quadratic nonlinearity is not necessarily the same as the polarization of the source-frequency beam, and we are able to derive a general analytic solution for second-harmonic generation from a Gaussian source condition that gives explicitly the relationship between the polarization of the source-frequency beam and the polarization of the second harmonic.

Second-harmonic generation in shear wave beams with different polarizations

International Nuclear Information System (INIS)

Spratt, Kyle S.; Ilinskii, Yurii A.; Zabolotskaya, Evgenia A.; Hamilton, Mark F.

2015-01-01

A coupled pair of nonlinear parabolic equations was derived by Zabolotskaya [1] that model the transverse components of the particle motion in a collimated shear wave beam propagating in an isotropic elastic solid. Like the KZK equation, the parabolic equation for shear wave beams accounts consistently for the leading order effects of diffraction, viscosity and nonlinearity. The nonlinearity includes a cubic nonlinear term that is equivalent to that present in plane shear waves, as well as a quadratic nonlinear term that is unique to diffracting beams. The work by Wochner et al. [2] considered shear wave beams with translational polarizations (linear, circular and elliptical), wherein second-order nonlinear effects vanish and the leading order nonlinear effect is third-harmonic generation by the cubic nonlinearity. The purpose of the current work is to investigate the quadratic nonlinear term present in the parabolic equation for shear wave beams by considering second-harmonic generation in Gaussian beams as a second-order nonlinear effect using standard perturbation theory. In order for second-order nonlinear effects to be present, a broader class of source polarizations must be considered that includes not only the familiar translational polarizations, but also polarizations accounting for stretching, shearing and rotation of the source plane. It is found that the polarization of the second harmonic generated by the quadratic nonlinearity is not necessarily the same as the polarization of the source-frequency beam, and we are able to derive a general analytic solution for second-harmonic generation from a Gaussian source condition that gives explicitly the relationship between the polarization of the source-frequency beam and the polarization of the second harmonic

Working for a not-for-Profit Research and Development Organization in the Earth Sciences

Science.gov (United States)

McKague, h L

2001-12-01

The Southwest Research Institute (SwRI) is an independent not-for-profit applied engineering and physical sciences research and development organization. This means that SwRI owes no allegiance to organizations other than its clients. As a not-for-profit organization, SwRI reinvests its net income into the organization to improve, strengthen, and expand facilities and to support internal research and development projects. Located in San Antonio, Texas, on 1200 acres, SwRI employs nearly 2800 staff and occupies nearly 2,000,000 square feet of office space. Its business is about equally divided between commercial and government clients, most of whom have specific scientific and technical problems that need to be solved in a timely, cost-effective manner. Governmental clients include local, state, and federal agencies and foreign governments. Commercial clients include local, national, and international businesses. Earth science disciplines at SwRI include geology, geophysics, hydrology, geochemistry, rock mechanics, mining engineering, and natural hazard assessment. Our overall approach is to systematically examine client problems and develop solutions that may include field work, laboratory work, numerical modeling, or some combination of these approaches. This method of problem solving places a strong emphasis on interdisciplinary teamwork. The work environment at SwRI strikes a balance among the freedom to attack technically important problems, consistent support to professional development, and a strong commitment to meeting client's deadlines and goals. Real problems with real consequences are routinely solved on a tight schedule. The diversity of clients gives exposure to an extraordinarily wide range of problems. Successful employees have sound technical backgrounds, are flexible in accommodating varying clients needs, bring creativity and energy to problem solving and applications of technologies, can work on multiple tasks in parallel, and can communicate

Polymer science applied to petroleum production; Ciencia de polimeros aplicada a producao de petroleo

Energy Technology Data Exchange (ETDEWEB)

Lucas, Elizabete F.; Mansur, Claudia R.E.; Garreto, Maria S.E.; Honse, Siller O.; Mazzeo, Claudia P.P. [Universidade Federal do Rio de Janeiro/ Instituto de Macromoleculas/ Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, Rio de Janeiro, RJ (Brazil)], e-mail: elucas@ima.ufrj.br

2011-07-01

The petroleum production comprises several operations, from well drilling to oil and water treatment, in which polymer science is applied. This work is focused in the phase behavior of asphaltenes that can be evaluated by precipitation tests and particle size determination. Recent researches show that the petroleum can be diluted with a specific model solvent, without causing any changes on asphaltenes phase behavior, and that a representative model system can be obtained if asphaltenes could be extracted using n-alkane as low as C1. The phase behavior of asphaltenes directly depends on the solubility parameter, which can be estimated for petroleum and asphaltenic fractions by microcalorimetry. More polar asphaltenes are not completely stabilized by less polar molecules, and this affects the stability of the A/O emulsions. There is a relationship between the amount of polar groups in the polymer chain and its capability in stabilizing/flocculating the asphaltenes, which interferes in the asphaltenes particle sizes. (author)

Using science to improve the dissemination and evaluation of scientific work.

Directory of Open Access Journals (Sweden)

Brett Thomas Buttliere

2014-08-01

Full Text Available Here we examine what science can tell us about the problems in psychological publishing and how to best address those problems. First, the motivation behind questionable research practices is examined (the desire to get ahead or, at least, not fall behind. Next, behavior modification strategies are discussed, pointing out that the carrot works better than the stick. Finally, we suggest that the best way to achieve real change is to make a tool so useful that academics make time to learn and utilize it on their own. Implementation of current change initiatives is hindered by a lack of norms, high initial buy-in costs, and uncertain payoffs. With this in mind, we pull together current open science tools to increase the utility while lowering effort and risk. One, centralized, easy to use, platform, with a profile, a feed of targeted science stories based on previous system interaction, a sophisticated (public comment and rating section, and impact metrics which use the available data can be used to realign individual and group motives. Some advantages of centrally digitizing communications are outlined, including ways the data could be used to improve the peer review process.

Three-photon polarization ququarts: polarization, entanglement and Schmidt decompositions

International Nuclear Information System (INIS)

Fedorov, M V; Miklin, N I

2015-01-01

We consider polarization states of three photons, propagating collinearly and having equal given frequencies but with arbitrary distributed horizontal or vertical polarizations of photons. A general form of such states is a superposition of four basic three-photon polarization modes, to be referred to as the three-photon polarization ququarts (TPPQ). All such states can be considered as consisting of one- and two-photon parts, which can be entangled with each other. The degrees of entanglement and polarization, as well as the Schmidt decomposition and Stokes vectors of TPPQ are found and discussed. (paper)

Piezoelectricity and rotostriction through polar and non-polar coupled instabilities in bismuth-based piezoceramics.

Science.gov (United States)

Acosta, Matias; Schmitt, Ljubomira A; Cazorla, Claudio; Studer, Andrew; Zintler, Alexander; Glaum, Julia; Kleebe, Hans-Joachim; Donner, Wolfgang; Hoffman, Mark; Rödel, Jürgen; Hinterstein, Manuel

2016-07-01

Coupling of order parameters provides a means to tune functionality in advanced materials including multiferroics, superconductors, and ionic conductors. We demonstrate that the response of a frustrated ferroelectric state leads to coupling between order parameters under electric field depending on grain orientation. The strain of grains oriented along a specific crystallographic direction, 〈h00〉, is caused by converse piezoelectricity originating from a ferrodistortive tetragonal phase. For 〈hhh〉 oriented grains, the strain results from converse piezoelectricity and rotostriction, as indicated by an antiferrodistortive instability that promotes octahedral tilting in a rhombohedral phase. Both strain mechanisms combined lead to a colossal local strain of (2.4 ± 0.1) % and indicate coupling between oxygen octahedral tilting and polarization, here termed "rotopolarization". These findings were confirmed with electromechanical experiments, in situ neutron diffraction, and in situ transmission electron microscopy in 0.75Bi1/2Na1/2TiO3-0.25SrTiO3. This work demonstrates that polar and non-polar instabilities can cooperate to provide colossal functional responses.

Polarization splitter and polarization rotator designs based on transformation optics.

Science.gov (United States)

Kwon, Do-Hoon; Werner, Douglas H

2008-11-10

The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

Applications of circularly polarized photons at the ALS with a bend magnet source

International Nuclear Information System (INIS)

1992-02-01

The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High T c Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements

MEASUREMENT OF POLARIZATION OBSERVABLES IN VECTOR MESON PHOTOPRODUCTION USING A TRANSVERSELY-POLARIZED FROZEN-SPIN TARGET AND POLARIZED PHOTONS AT CLAS, JEFFERSON LAB

Energy Technology Data Exchange (ETDEWEB)

Roy, Priyashree [Florida State Univ., Tallahassee, FL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-11-30

The study of baryon resonances provides a deeper understanding of the strong interaction because the dynamics and relevant degrees of freedom hidden within them are re ected by the properties of the excited states of baryons. Higher-lying excited states at and above 1.7 GeV/c2 are generally predicted to have strong couplings to final states involving a heavier meson, e. g. one of the vector mesons, ρ, ω φ, as compared to a lighter pseudoscalar meson, e. g. π and η. Decays to the ππΝ final states via πΔ also become more important through the population of intermediate resonances. We observe that nature invests in mass rather than momentum. The excited states of the nucleon are usually found as broadly overlapping resonances which may decay into a multitude of final states involving mesons and baryons. Polarization observables make it possible to isolate single resonance contributions from other interference terms. The CLAS g9 (FROST) experiment, as part of the N* spectroscopy program at Je?erson Laboratory, accumulated photoproduction data using circularly- & linearly-polarized photons incident on a transversely-polarized butanol target (g9b experiment) in the photon energy range 0:3-2:4 GeV & 0:7-2:1 GeV, respectively. In this work, the analysis of reactions and polarization observables which involve two charged pions, either in the fully exclusive reaction γρ -> ρπ+π- or in the semi-exclusive reaction with a missing neutral pion, γρ -> ρπ+π-(π0) will be presented. For the reaction ρπ+π-, eight polarization observables (Is, Ic, Px, Py, Psx; y, Pcx; y) have been extracted. The high statistics data rendered it possible to extract these observables in three dimensions. All of them are first-time measurements. The fairly good agreement of Is, Ic obtained from this analysis with the experimental results from a previous CLAS experiment provides support for the first-time measurements. For the reaction γρ -> ρω -> ρπ+π(π0, five polarization

Polarity Control in Group-III Nitrides beyond Pragmatism

Science.gov (United States)

Mohn, Stefan; Stolyarchuk, Natalia; Markurt, Toni; Kirste, Ronny; Hoffmann, Marc P.; Collazo, Ramón; Courville, Aimeric; Di Felice, Rosa; Sitar, Zlatko; Vennéguès, Philippe; Albrecht, Martin

2016-05-01

Controlling the polarity of polar semiconductors on nonpolar substrates offers a wealth of device concepts in the form of heteropolar junctions. A key to realize such structures is an appropriate buffer-layer design that, in the past, has been developed by empiricism. GaN or ZnO on sapphire are prominent examples for that. Understanding the basic processes that mediate polarity, however, is still an unsolved problem. In this work, we study the structure of buffer layers for group-III nitrides on sapphire by transmission electron microscopy as an example. We show that it is the conversion of the sapphire surface into a rhombohedral aluminum-oxynitride layer that converts the initial N-polar surface to Al polarity. With the various AlxOyNz phases of the pseudobinary Al2O3 -AlN system and their tolerance against intrinsic defects, typical for oxides, a smooth transition between the octahedrally coordinated Al in the sapphire and the tetrahedrally coordinated Al in AlN becomes feasible. Based on these results, we discuss the consequences for achieving either polarity and shed light on widely applied concepts in the field of group-III nitrides like nitridation and low-temperature buffer layers.

Vertically Polarized Omnidirectional Printed Slot Loop Antenna

DEFF Research Database (Denmark)

Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

2015-01-01

A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

International Nuclear Information System (INIS)

Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

2010-01-01

We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

NASA LWS Institute GIC Working Group: GIC science, engineering and applications readiness

Science.gov (United States)

Pulkkinen, A. A.; Thomson, A. W. P.; Bernabeu, E.

2016-12-01

In recognition of the rapidly growing interest on the topic, this paper is based on the findings of the very first NASA Living With a Star (LWS) Institute Working Group that was specifically targeting the GIC issue. The new LWS Institutes program element was launched 2014 and the concept is built around small working group style meetings that focus on well defined problems that demand intense, direct interactions between colleagues in neighboring disciplines to facilitate the development of a deeper understanding of the variety of processes that link the solar activity to Earth's environment. The LWS Institute Geomagnetically Induced Currents (GIC) Working Group (WG) led by A. Pulkkinen (NASA GSFC) and co-led by E. Bernabeu (PJM) and A. Thomson (BGS) was selected competitively as the pilot activity for the new LWS element. The GIC WG was tasked to 1) identify, advance, and address the open scientific and engineering questions pertaining to GIC, 2) advance predictive modeling of GIC, 3) advocate and act as a catalyst to identify resources for addressing the multidisciplinary topic of GIC. In this paper, we target the goal 1) of the GIC WG. More specifically, the goal of this paper is to review the current status and future challenges pertaining to science, engineering and applications of the GIC problem. Science is understood here as the basic space and Earth sciences research that allow improved understanding and physics-based modeling of physical processes behind GIC. Engineering in turn is understood here as the "impact" aspect of GIC. The impact includes any physical effects GIC may have on the performance of the manmade infrastructure. Applications is understood as the models, tools and activities that can provide actionable information to entities such as power systems operators for mitigating the effects of GIC and government for managing any potential consequences from GIC impact to critical infrastructure. In this sense, applications can be considered as

Polarized electron sources

Energy Technology Data Exchange (ETDEWEB)

Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

1994-12-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

Polarized electron sources

International Nuclear Information System (INIS)

Prepost, R.

1994-01-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

Polarization Of Light In The Natural Environment

Science.gov (United States)

Coulson, Kinsell L.

1990-01-01

This paper provides a characterization of the fields of light polarization with which the optical designer or user of optical devices in the natural environment must be concerned. After a brief historical outline of the principal developments in polarization theory and observations during the last two centuries, the main emphasis is on the two primary processes responsible for the polarization of light in nature--scattering of light by particles of the atmosphere and reflection from soils, vegetation, snow, and water at the earth's surface. Finally, a seven minute film on polarization effects which can be seen in everyday surroundings will be shown. Scattering by atmospheric particles is responsible for high values of polarization in various atmospheric conditions and at certain scattering geometries. Such scattering particles include molecules of the atmospheric gases, aerosols of dust, haze, and air pollution, water droplets of fog and clouds, and the ice crystals of cirrus. It is seen that development of the theory of scattering by such particles has outstripped the measurements necessary for validation of the theory, a fact which points up the importance of symposia such as the present one. The reverse is true, however, for the polarizing properties of natural surfaces. Only in the case of still water is the theory of reflection adequate to characterize in a quantitative fashion the polarizing effects produced by the reflection of light from such natural surfaces. Polarization of light by reflection from vegetation is of prime importance in a remote sensing context, but much further work is needed to characterize vegetative reflectance for the purpose. The short film on polarization effects provides a good visualization technique and training aid for students interested in the field.

Potential Uses of EarthSLOT (an Earth Science, Logistics, and Outreach Terrainbase) for Education and Integration in the International Polar Year

Science.gov (United States)

Nolan, M.

2004-12-01

EarthSLOT is an internet-based, 3D, interactive terrain and data visualization system that may have many potential uses as an education and integration tool for International Polar Year projects. Recently funded by NSF's Office of Polar Programs for use in the Arctic, the global nature of the application lends itself well for use at both poles and everywhere in between. The application allows one to start with a spinning earth and zoom down to surface level. The highest resolution digital elevation models available provide the necessary 3D topographic perspective and a variety of possible high-resolution satellite and aerial imagery layers add surface realism; resolution can be down to the centimeter level for either type of data, and frequently acquired satellite imagery may be updated automatically as it arrives. Superimposed on this can be nearly any form of vector or annotation layers, such as shapefiles, polygons, point data, and 3D models (still and moving), which can be easily imported from existing GIS applications or spreadsheets. External databases can also be queried and the results served seamlessly. The entire application is served over the internet, and any connection with speeds over 300kps allows one to interactively fly with a minimum of performance lag. EarthSLOT stands for Earth Science, Logistics, and Outreach Terrainbase, targeting the user-groups of scientists, logisticians, and the public. Approved scientific users can add their own vector content to the application on their own, such that they can create their own custom applications featuring their data but using our underlying earth model with a minimum of interaction with us. For example, an oceanographer can add ship tracks or buoy locations to the model with links to data, host the link on his or her own web page, and invite collaborators to view the spatial relationship of their data to underlying bathymetry. Logisticians or program managers interested in understanding the spatial

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2

Directory of Open Access Journals (Sweden)

I. Wohltmann

2017-07-01

Full Text Available The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs and Earth system models (ESMs to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx, HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect

Social and natural sciences differ in their research strategies, adapted to work for different knowledge landscapes.

Science.gov (United States)

Jaffe, Klaus

2014-01-01

Do different fields of knowledge require different research strategies? A numerical model exploring different virtual knowledge landscapes, revealed two diverging optimal search strategies. Trend following is maximized when the popularity of new discoveries determine the number of individuals researching it. This strategy works best when many researchers explore few large areas of knowledge. In contrast, individuals or small groups of researchers are better in discovering small bits of information in dispersed knowledge landscapes. Bibliometric data of scientific publications showed a continuous bipolar distribution of these strategies, ranging from natural sciences, with highly cited publications in journals containing a large number of articles, to the social sciences, with rarely cited publications in many journals containing a small number of articles. The natural sciences seem to adapt their research strategies to landscapes with large concentrated knowledge clusters, whereas social sciences seem to have adapted to search in landscapes with many small isolated knowledge clusters. Similar bipolar distributions were obtained when comparing levels of insularity estimated by indicators of international collaboration and levels of country-self citations: researchers in academic areas with many journals such as social sciences, arts and humanities, were the most isolated, and that was true in different regions of the world. The work shows that quantitative measures estimating differences between academic disciplines improve our understanding of different research strategies, eventually helping interdisciplinary research and may be also help improve science policies worldwide.

77 FR 48506 - Notice of Submission for OMB Review; Institute of Education Sciences; What Works Clearinghouse

Science.gov (United States)

2012-08-14

... DEPARTMENT OF EDUCATION Notice of Submission for OMB Review; Institute of Education Sciences; What... request to continue a currently approved collection under OMB Control Number 1850-0788 for the What Works... considered public records. Title of Collection: What Works Clearinghouse. OMB Control Number: 1850-0788. Type...

Post-doctoral research work developed at the National Institute for Fusion Science - Japan

International Nuclear Information System (INIS)

Ueda, M.

1992-05-01

This is a research report report on the work developed at the National Institute for Fusion Science - Japan, involving study of Beam Emission Spectroscopy. It describes the use of a fast neutral lithium beam (8 KeV) to measure the density profile in a Compact Helical Device. (A.C.A.S.)

Generation of coordinates in PC for graphics of polar figure; Generacion de coordenadas en microcomputadora para graficado de figura polar

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R

1991-10-15

The preferential orientation, not alone it exists in metals, but also in minerals or in general in crystalline materials, notwithstanding in the metals it can be transformed by means of those processes of having mechanical worked such as laminate, wrapping, etc. To the preferable orientation of the crystals is also known as texture and since the properties of the crystalline materials lens depend on the orientation that present its glasses, it is important to know its texture. The difficulty for to represent and to describe the grade of preferential orientation in textured materials take to F. Weber to adapt the stereo graphic projection of a monocrystal to a poles figure. Later on, its appeared but methods to obtain the polar figure, among them, that of reflection of L. G. Schultz, but again a technique appears it specifies for its obtaining. In all the cases, the methodology is the following one: a) It is obtained by means of the diffraction process, the correspondent spectra in digitized form. b) it is applied process of having softened mathematician of the spectrum. c) there are determined the fi coordinates, beta and intensity for graph nts of the polar figure. d) Its are graph the points generated in c obtaining the polar figures. The objective of this work, is leaving of a softened spectra, to generate the coordinated fi, beta and corresponding intensity to proceed to their graph and generation of the polar figure. In this specific work, the methodology of Philips is used that consists in making a sweeping in hairspring form with the radiation to detect in these points the execution of the Bragg law. (Author)

Improved Electron Yield and Spin-Polarization from III-V Photocathodes via Bias Enhanced Carrier Drift: Final Report

International Nuclear Information System (INIS)

Mulhollan, Gregory A.

2006-01-01

In this DOE STTR program, Saxet Surface Science, with the Stanford Linear Accelerator Center as partner, designed, built and tested photocathode structures such that optimal drift-enhanced spin-polarization from GaAs based photoemitters was achieved with minimal bias supply requirements. The forward bias surface grid composition was optimized for maximum polarization and yield, together with other construction parameters including doping profile. This program has culminated in a cathode bias structure affording increased electron spin polarization when applied to III-V based photocathodes. The optimized bias structure has been incorporated into a cathode mounting and biasing design for use in a polarized electron gun.

Understanding How Science Works: The Nature of Science as The Foundation for Science Teaching and Learning

Science.gov (United States)

McComas, William F.

2017-01-01

The nature of science (NOS) is a phrase used to represent the rules of the game of science. Arguably, NOS is the most important content issue in science instruction because it helps students understand the way in which knowledge is generated and validated within the scientific enterprise. This article offers a proposal for the elements of NOS that…

First Regge parameterisation of polarized DIS cross section

International Nuclear Information System (INIS)

Thomas, E.; Bianchi, N.

2000-01-01

The first Regge description of the virtual photon absorption cross section difference Δσ(γ*, N) = [σ 1/2 (γ*,N) - σ ((3)/(2)) (γ*, N)] was obtained from a global fit of all the data collected by the experiments measuring spin asymmetries in polarized lepton - polarized nucleon deep inelastic scattering. This work present a phenomenological and a numerical description of all the polarized deep inelastic data (Δσ(γ*, N), g l spin structure function) on the whole measured kinematical range (0.3 GeV 2 2 2 , 4 GeV 2 2 2 ). The fit also provide reliable predictions for the photo-production limit through a smooth Q 2 -transition

Polarizing matter and antimatter: A new method

International Nuclear Information System (INIS)

Onel, Y.

1992-02-01

Several years ago a self-polarization effect for stored (anti)- protons and ions was investigated theoretically. The effect is based on the well-known Stern-Gerlach effect in gradient fields. The aim of the ongoing measurements at the Indiana University Cyclotron Facility (IUCF) is to verify experimentally the various assumptions on which this effect is based. The final goal is to demonstrate this new polarization effect. The proposed effect could be a powerful tool to produce polarized stored hadron beams both in the low-energy range and at SSC and LHC energies. In this progress report we will describe our progress in three parts: (A) Experimental work at IUCF Cooler Ring; (B) Our extensive computer simulations of the spin stability for the IUCF Cooler Ring; and (C) Theoretical studies

Polarization-independent broadband meta-holograms via polarization-dependent nanoholes.

Science.gov (United States)

Zhang, Xiaohu; Li, Xiong; Jin, Jinjin; Pu, Mingbo; Ma, Xiaoliang; Luo, Jun; Guo, Yinghui; Wang, Changtao; Luo, Xiangang

2018-05-17

Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms. The fabricated meta-hologram exhibits a polarization insensitive feature with an acceptable image quality. We verify the feasibility of the design algorithm for three-dimensional (3D) meta-holograms with simulation and the feasibility for two-dimensional (2D) meta-holograms is experimentally demonstrated at a broadband wavelength range from 405 nm to 632.8 nm. The effective polarization-independent broadband complex wavefront control with anisotropic elliptical nanoholes proposed in this paper greatly promotes the practical applications of the metasurface in technologies associated with wavefront manipulation, such as flat lens, colorful holographic displays and optical storage.

Let’s Talk about Citizen Science: What Doesn’t Work

Directory of Open Access Journals (Sweden)

Allison B. Kaufman

2014-11-01

Full Text Available “Citizen Science,” or the idea of using interested laypeople to assist in data collection, has the potential to be a valuable resource to those who study animal cognition. This is largely due to the potential increase in sample size it can provide. However, this technique also has the potential to introduce a significant amount of error to an experiment. As a result, before citizen science can be used as a tool, it is important to determine how it best works; specifically, what methods best motivate people to participate and to provide the most accurate data. This includes sharing situations in which data collection was not successful. Presented here is a failed attempt at collecting data on mirror self-recognition (MSR in pet parrots, orchestrated via yahoo groups listservs. The goals in presenting this unsuccessful methodology are to encourage discussion, to prevent others from repeating the same ill-fated methodology, and to encourage others to attempt variations on said methods which might be more successful.

Thinking about information work of nuclear science and technology in the age of big data: speaking of the information analysis and research

International Nuclear Information System (INIS)

Chen Tieyong

2014-01-01

Human society is entering a 'PB' (1024TB) the new era as the unit of structured and unstructured data, In the network era, with the development of mobile communications, electronic commerce, the emergence and development of social network. Now, a large-scale production, sharing and application data era is opening. How to explore the value of data, to conquer big data, to get useful information, is an important task of our science and technology information workers. This paper tries to analyze the development of the nuclear science and technology information work from big data obtain, analysis, application. Our analysis and research work for information will be increasingly based on all data and analysis, Instead of random sampling. The data 'sound' is possible. A lot of results of information analysis and research can be expressed quantitatively. We should attach great importance to data collection, careful analysis of the big data. We involves the professional division of labor, but also to cooperation In nuclear science and technology information analysis and research process. In addition, we should strengthen the nuclear science and technology information resource construction, improve Information supply; strengthen the analysis and research of nuclear science and technology information, improve the information service; strengthen information management of nuclear science and technology, pay attention to the security problems and intellectual property rights in information sharing; strengthen personnel training, continuously improve the nuclear science and technology information work efficiency and performance. In the age of big data, our nuclear science and technology information workers shall be based on the information analysis and study as the core, one hand grasping information collection, another hand grasping information service, forge ahead and innovation, continuous improvement working ability of nuclear science and technology information, improve the

Science Communication versus Science Education: The Graduate Student Scientist as a K-12 Classroom Resource

Science.gov (United States)

Strauss, Jeff; Shope, Richard E., III; Terebey, Susan

2005-01-01

Science literacy is a major goal of science educational reform (NRC, 1996; AAAS, 1998; NCLB Act, 2001). Some believe that teaching science only requires pedagogical content knowledge (PCK). Others believe doing science requires knowledge of the methodologies of scientific inquiry (NRC, 1996). With these two mindsets, the challenge for science educators is to create models that bring the two together. The common ground between those who teach science and those who do science is science communication, an interactive process that galvanizes dialogue among scientists, teachers, and learners in a rich ambience of mutual respect and a common, inclusive language of discourse . The dialogue between science and non-science is reflected in the polarization that separates those who do science and those who teach science, especially as it plays out everyday in the science classroom. You may be thinking, why is this important? It is vital because, although not all science learners become scientists, all K-12 students are expected to acquire science literacy, especially with the implementation of the No Child Left Behind Act of 2001 (NCLB). Students are expected to acquire the ability to follow the discourse of science as well as connect the world of science to the context of their everyday life if they plan on moving to the next grade level, and in some states, to graduate from high school. This paper posits that science communication is highly effective in providing the missing link for K-12 students cognition in science and their attainment of science literacy. This paper will focus on the "Science For Our Schools" (SFOS) model implemented at California State Univetsity, Los Angeles (CSULA) as a project of the National Science Foundation s GK-12 program, (NSF 2001) which has been a huge success in bridging the gap between those who "know" science and those who "teach" science. The SFOS model makes clear the distinctions that identify science, science communication, science

The First Paleomagnetic Polar Wander Path

Science.gov (United States)

Creer, K. M.

2004-12-01

At the end of 1952, having completed my work on the Cambridge astatic magnetometer, I was motivated to embark on a "Preliminary Paleomagnetic Survey of Rocks from the British Isles" by exciting results obtained by two fellow research students:- Jan Hospers' proposal of the axial dipole hypothesis and Ted Irving's discovery of strongly oblique Pre-Cambrian paleomagnetic directions, substantiated by the oblique Triassic directions obtained by John Clegg's group. Geologists advised me to collect from palaeontologically well dated rock formations. But these turned out to be very weakly magnetized and thereafter I concentrated on purple and dark red coloured rock formations. By the end of July 1954 I had compiled a table of nine Period-mean paleomagnetic directions spanning the last 600 Myr. I passed a copy to Keith Runcorn to include in a talk (co-authors Creer and Irving) scheduled for the August 1954 Rome Assembly of IAGA. Meanwhile, background reading took me to Gutenberg's "Internal Constitution of the Earth (1951)" where I came across (Fig 12) paths of the north pole proposed by Kreichgauer (1902) and by Koppen and Wegener (1924). This prompted me to calculate a paleomagnetic polar wander path. I presented this at the Annual Meeting of the British Association for the Advancement of Science held at Oxford on September 8th. An artist's representation of it was published in Time Magazine of September 24th 1954 where the accompanying text records that I stressed that similar work on other continents would be necessary to distinguish whether the continents had drifted independently or whether the sole mechanism had been polar wander. On my return to Cambridge, Maurice Hill informally suggested that I should indicate precision, so for each pole I calculated semi-major and minor axes of the ellipse of confidence corresponding to the radius of confidence of each mean direction. These were shown in my Ph.D. thesis, where also I calculated a paleomagnetic pole for John

General experiences + race + racism = Work lives of Black faculty in postsecondary science education

Science.gov (United States)

Parsons, Eileen R. C.; Bulls, Domonique L.; Freeman, Tonjua B.; Butler, Malcolm B.; Atwater, Mary M.

2016-12-01

Existent research indicates that postsecondary Black faculty members, who are sorely underrepresented in the academy especially in STEM fields, assume essential roles; chief among these roles is diversifying higher education. Their recruitment and retention become more challenging in light of research findings on work life for postsecondary faculty. Research has shown that postsecondary faculty members in general have become increasingly stressed and job satisfaction has declined with dissatisfaction with endeavors and work overload cited as major stressors. In addition to the stresses managed by higher education faculty at large, Black faculty must navigate diversity-related challenges. Illuminating and understanding their experiences can be instrumental in lessening stress and job dissatisfaction, outcomes that facilitate recruitment and retention. This study featured the experiences and perceptions of Black faculty in science education. This study, framed by critical race theory, examines two questions: What characterizes the work life of some Black faculty members who teach, research, and serve in science education? How are race and racism present in the experiences of these postsecondary Black faculty members? A phenomenological approach to the study situates the experiences of the Black participants as valid phenomena worthy of investigation, illuminates their experiences, and seeks to retain the authenticity of their voices.

Polarized light scattering as a probe for changes in chromosome structure

Energy Technology Data Exchange (ETDEWEB)

Shapiro, Daniel Benjamin [Univ. of California, Berkeley, CA (United States)

1993-10-01

Measurements and calculations of polarized light scattering are applied to chromosomes. Calculations of the Mueller matrix, which completely describes how the polarization state of light is altered upon scattering, are developed for helical structures related to that of chromosomes. Measurements of the Mueller matrix are presented for octopus sperm heads, and dinoflagellates. Comparisons of theory and experiment are made. A working theory of polarized light scattering from helices is developed. The use of the first Born approximation vs the coupled dipole approximation are investigated. A comparison of continuous, calculated in this work, and discrete models is also discussed. By comparing light scattering measurements with theoretical predictions the average orientation of DNA in an octopus sperm head is determined. Calculations are made for the Mueller matrix of DNA plectonemic helices at UV, visible and X-ray wavelengths. Finally evidence is presented that the chromosomes of dinoflagellates are responsible for observed differential scattering of circularly-polarized light. This differential scattering is found to vary in a manner that is possibly correlated to the cell cycle of the dinoflagellates. It is concluded that by properly choosing the wavelength probe polarized light scattering can provide a useful tool to study chromosome structure.

Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

Science.gov (United States)

Dovhaliuk, Rostyslav Yu

2018-02-01

Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

Optical field-strength polarization of two-mode single-photon states

Energy Technology Data Exchange (ETDEWEB)

Linares, J; Nistal, M C; Barral, D; Moreno, V, E-mail: suso.linares.beiras@usc.e [Optics Area, Department of Applied Physics, Faculty of Physics and School of Optics and Optometry, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782-Santiago de Compostela, Galicia (Spain)

2010-09-15

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

Optical field-strength polarization of two-mode single-photon states

International Nuclear Information System (INIS)

Linares, J; Nistal, M C; Barral, D; Moreno, V

2010-01-01

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

An analog VLSI chip emulating polarization vision of Octopus retina.

Science.gov (United States)

Momeni, Massoud; Titus, Albert H

2006-01-01

Biological systems provide a wealth of information which form the basis for human-made artificial systems. In this work, the visual system of Octopus is investigated and its polarization sensitivity mimicked. While in actual Octopus retina, polarization vision is mainly based on the orthogonal arrangement of its photoreceptors, our implementation uses a birefringent micropolarizer made of YVO4 and mounted on a CMOS chip with neuromorphic circuitry to process linearly polarized light. Arranged in an 8 x 5 array with two photodiodes per pixel, each consuming typically 10 microW, this circuitry mimics both the functionality of individual Octopus retina cells by computing the state of polarization and the interconnection of these cells through a bias-controllable resistive network.

Applications of polarization speckle in skin cancer detection and monitoring

Science.gov (United States)

Lee, Tim K.; Tchvialeva, Lioudmila; Phillips, Jamie; Louie, Daniel C.; Zhao, Jianhua; Wang, Wei; Lui, Harvey; Kalia, Sunil

2018-01-01

Polarization speckle is a rapidly developed field. Unlike laser speckle, polarization speckle consists of stochastic interference patterns with spatially random polarizations, amplitudes and phases. We have been working in this exciting research field, developing techniques to generate polarization patterns from skin. We hypothesize that polarization speckle patterns could be used in biomedical applications, especially, for detecting and monitoring skin cancers, the most common neoplasmas for white populations around the world. This paper describes our effort in developing two polarization speckle devices. One of them captures the Stokes parameters So and S1 simultaneously, and another one captures all four Stokes parameters So, S1, S2, and S3 in one-shot, within milliseconds. Hence these two devices could be used in medical clinics and assessed skin conditions in-vivo. In order to validate our hypothesis, we conducted a series of three clinical studies. These are early pilot studies, and the results suggest that the devices have potential to detect and monitor skin cancers.

A Bionic Polarization Navigation Sensor and Its Calibration Method.

Science.gov (United States)

Zhao, Huijie; Xu, Wujian

2016-08-03

The polarization patterns of skylight which arise due to the scattering of sunlight in the atmosphere can be used by many insects for deriving compass information. Inspired by insects' polarized light compass, scientists have developed a new kind of navigation method. One of the key techniques in this method is the polarimetric sensor which is used to acquire direction information from skylight. In this paper, a polarization navigation sensor is proposed which imitates the working principles of the polarization vision systems of insects. We introduce the optical design and mathematical model of the sensor. In addition, a calibration method based on variable substitution and non-linear curve fitting is proposed. The results obtained from the outdoor experiments provide support for the feasibility and precision of the sensor. The sensor's signal processing can be well described using our mathematical model. A relatively high degree of accuracy in polarization measurement can be obtained without any error compensation.

Investigation on principle of polarization-difference imaging in turbid conditions

Science.gov (United States)

Ren, Wei; Guan, Jinge

2018-04-01

We investigate the principle of polarization-difference imaging (PDI) of objects in optically scattering environments. The work is performed by both Marius's law and Mueller-Stokes formalism, and is further demonstrated by simulation. The results show that the object image is obtained based on the difference in polarization direction between the scatter noise and the target signal, and imaging performance is closely related to the choice of polarization analyzer axis. In addition, this study illustrates the potential of Stoke vector for promoting application of PDI system in the real world scene.

Breaking the Ice: Strategies for Future European Research in the Polar Oceans - The AURORA BOREALIS Concept

Science.gov (United States)

Lembke-Jene, L.; Biebow, N.; Wolff-Boenisch, B.; Thiede, J.; European Research Icebreaker Consortium

2011-12-01

Research vessels dedicated to work in polar ice-covered waters have only rarely been built. Their history began with Fritjof Nansen's FRAM, which he used for his famous first crossing of the Arctic Ocean 1893-1896. She served as example for the first generation of polar research vessels, at their time being modern instruments planned with foresight. Ice breaker technology has developed substantially since then. However, it took almost 80 years until this technical advance also reached polar research, when the Russian AKADEMIK FEDEROV, the German POLARSTERN, the Swedish ODEN and the USCG Cutter HEALY were built. All of these house modern laboratories, are ice-breakers capable to move into the deep-Arctic during the summer time and represent the second generation of dedicated polar research vessels. Still, the increasing demand in polar marine research capacities by societies that call for action to better understand climate change, especially in the high latitudes is not matched by adequate facilities and resources. Today, no icebreaker platform exists that is permanently available to the international science community for year-round expeditions into the central Arctic Ocean or heavily ice-infested waters of the polar Southern Ocean around Antarctica. The AURORA BOREALIS concept plans for a heavy research icebreaker, which will enable polar scientists around the world to launch international research expeditions into the central Arctic Ocean and the Antarctic continental shelf seas autonomously during all seasons of the year. The European Research Icebreaker Consortium - AURORA BOREALIS (ERICON-AB) was established in 2008 to plan the scientific, governance, financial, and legal frameworks needed for the construction and operation of this first multi-nationally owned and operated research icebreaker and polar scientific drilling platform. By collaborating together and sharing common infrastructures it is envisioned that European nations make a major contribution to

Polarization holography

DEFF Research Database (Denmark)

Nikolova, L.; Ramanujam, P.S.

Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

Polarized neutron spectrometer

International Nuclear Information System (INIS)

Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

2000-01-01

The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

Direct Probing of Polarization Charge at Nanoscale Level

Energy Technology Data Exchange (ETDEWEB)

Kwon, Owoong [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Seol, Daehee [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Lee, Dongkyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Han, Hee [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Lindfors-Vrejoiu, Ionela [Univ. of Cologne (Germany). Physics Inst.; Lee, Woo [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Jesse, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Lee, Ho Nyung [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Kalinin, Sergei V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Alexe, Marin [Univ. of Warwick, Coventry (United Kingdom). Dept. of Physics; Kim, Yunseok [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering

2017-11-14

Ferroelectric materials possess spontaneous polarization that can be used for multiple applications. Owing to a long-term development of reducing the sizes of devices, the preparation of ferroelectric materials and devices is entering the nanometer-scale regime. In order to evaluate the ferroelectricity, there is a need to investigate the polarization charge at the nanoscale. Nonetheless, it is generally accepted that the detection of polarization charges using a conventional conductive atomic force microscopy (CAFM) without a top electrode is not feasible because the nanometer-scale radius of an atomic force microscopy (AFM) tip yields a very low signal-to-noise ratio. But, the detection is unrelated to the radius of an AFM tip and, in fact, a matter of the switched area. In this work, the direct probing of the polarization charge at the nanoscale is demonstrated using the positive-up-negative-down method based on the conventional CAFM approach without additional corrections or circuits to reduce the parasitic capacitance. The polarization charge densities of 73.7 and 119.0 µC cm^-2 are successfully probed in ferroelectric nanocapacitors and thin films, respectively. The results we obtained show the feasibility of the evaluation of polarization charge at the nanoscale and provide a new guideline for evaluating the ferroelectricity at the nanoscale.

Construction and test of a polarized proton target

International Nuclear Information System (INIS)

Aures, R.

1983-12-01

This work describes experiments in which for the first time a proton target has been constructed which is polarized by the ''brute-force'' method. This method requires very low temperatures and high magnetic fields. The low temperatures (down to 10 mK) are obtained by a 3 He/ 4 He dilution refrigerator, the magnetic field (up to 9 T) is produced by a superconducting split pair magnet. The proton target has a volume of about 18 cm 3 and consists of pressed titaniumhydride powder, which has a titanium/-hydrogen ratio of 1:1,96. The hydrogen content is 1,3 mol. Titaniumhydride has the advantage of sufficient heat conductivity at low temperatures and a very high proton density. The heat conductivity of the sample is measured, with and without the presence of a magnetic field. Thermodynamical measurements and adiabatic demagnetisation experiments proved quantitatively the polarization of the protons. The polarization of the proton has been measured in a transmission experiment using polarized neutrons of 1.2 MeV. The result shows a good agreement of theoretical and actual polarization. From the results it can be concluded, that this sample can be used successfully as a polarized proton target for neutron scattering experiments to measure spin-correlations. (orig.) [de

Reflection of a polarized light cone

Science.gov (United States)

Brody, Jed; Weiss, Daniel; Berland, Keith

2013-01-01

We introduce a visually appealing experimental demonstration of Fresnel reflection. In this simple optical experiment, a polarized light beam travels through a high numerical-aperture microscope objective, reflects off a glass slide, and travels back through the same objective lens. The return beam is sampled with a polarizing beam splitter and produces a surprising geometric pattern on an observation screen. Understanding the origin of this pattern requires careful attention to geometry and an understanding of the Fresnel coefficients for S and P polarized light. We demonstrate that in addition to a relatively simple experimental implementation, the shape of the observed pattern can be computed both analytically and by using optical modeling software. The experience of working through complex mathematical computations and demonstrating their agreement with a surprising experimental observation makes this a highly educational experiment for undergraduate optics or advanced-lab courses. It also provides a straightforward yet non-trivial system for teaching students how to use optical modeling software.

PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

DEFF Research Database (Denmark)

Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan

2018-01-01

PolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed....... The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment...... displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better...

Viewing past science from the point of view of present science, thereby illuminating both: Philosophy versus experiment in the work of Robert Boyle.

Science.gov (United States)

Chalmers, Alan

2016-02-01

The seventeenth century witnessed the replacement of an Aristotelian worldview by a mechanical one. It also witnessed the beginnings of significant experimental enquiry. Alerted by the fact that the methods involved in the latter, but not in the former, resemble those employed in later science, I argue the historical case that the emergence of the mechanical worldview and the emergence of science were not closely related and that it was the latter that was to develop into science as we have come to know it. The details are explored in the context of the philosophical and experimental work of Robert Boyle and the relationship between them. Copyright © 2015 Elsevier Ltd. All rights reserved.

A polarization system for persistent chemical detection

Science.gov (United States)

Craven-Jones, Julia; Appelhans, Leah; Couphos, Eric; Embree, Todd; Finnegan, Patrick; Goldstein, Dennis; Karelitz, David; LaCasse, Charles; Luk, Ting S.; Mahamat, Adoum; Massey, Lee; Tanbakuchi, Anthony; Washburn, Cody; Vigil, Steven

2015-09-01

We report on the development of a prototype polarization tag based system for detecting chemical vapors. The system primarily consists of two components, a chemically sensitive tag that experiences a change in its optical polarization properties when exposed to a specific chemical of interest, and an optical imaging polarimeter that is used to measure the polarization properties of the tags. Although the system concept could be extended to other chemicals, for the initial system prototype presented here the tags were developed to be sensitive to hydrogen fluoride (HF) vapors. HF is used in many industrial processes but is highly toxic and thus monitoring for its presence and concentration is often of interest for personnel and environmental safety. The tags are periodic multilayer structures that are produced using standard photolithographic processes. The polarimetric imager has been designed to measure the degree of linear polarization reflected from the tags in the short wave infrared. By monitoring the change in the reflected polarization signature from the tags, the polarimeter can be used to determine if the tag was exposed to HF gas. In this paper, a review of the system development effort and preliminary test results are presented and discussed, as well as our plan for future work.

Lunar true polar wander inferred from polar hydrogen.

Science.gov (United States)

Siegler, M A; Miller, R S; Keane, J T; Laneuville, M; Paige, D A; Matsuyama, I; Lawrence, D J; Crotts, A; Poston, M J

2016-03-24

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon

The Suomi National Polar-Orbiting Partnership (SNPP): Continuing NASA Research and Applications

Science.gov (United States)

Butler, James; Gleason, James; Jedlovec, Gary; Coronado, Patrick

2015-01-01