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Sample records for polar research columbus

  1. Candidate functions for advanced technology implementation in the Columbus mission planning environment

    Science.gov (United States)

    Loomis, Audrey; Kellner, Albrecht

    1988-01-01

    The Columbus Project is the European Space Agency's contribution to the International Space Station program. Columbus is planned to consist of three elements (a laboratory module attached to the Space Station base, a man-tended freeflyer orbiting with the Space Station base, and a platform in polar orbit). System definition and requirements analysis for Columbus are underway, scheduled for completion in mid-1990. An overview of the Columbus mission planning environment and operations concept as currently defined is given, and some of the challenges presented to software maintainers and ground segment personnel during mission operators are identified. The use of advanced technologies in system implementation is being explored. Both advantages of such solutions and potential problems they present are discussed, and the next steps to be taken by Columbus before targeting any functions for advanced technology implementation are summarized. Several functions in the mission planning process were identified as candidates for advanced technology implementation. These range from expert interaction with Columbus' data bases through activity scheduling and near-real-time response to departures from the planned timeline. Each function is described, and its potential for advanced technology implementation briefly assessed.

  2. The Columbus Myth: Power and Ideology in Picturebooks about Christopher Columbus

    Science.gov (United States)

    Desai, Christina M.

    2013-01-01

    In 1992, the 500th anniversary of Columbus's landing in the Bahamas was simultaneously celebrated and denounced in the US. Damaging facts about Columbus and the impact of his voyages were aired along with demands for truth and change. This study analyzes the power relationships and political ideology of picturebooks about Columbus published…

  3. Automation and robotics for COLUMBUS: An implementation concept for the free flying laboratory (MTFF)

    Science.gov (United States)

    Goelz, G.; Sommer, B.

    1992-01-01

    With nearly forty percent of the funding, Germany is the main contributor to the European COLUMBUS Programme, followed by Italy, France and further ESA member states. The COLUMBUS elements are the Attached Laboratory (APM) to be permanently attached to the Space Station FREEDOM, the polar platform (PPF) and the Man Tended Free Flyer (MTFF). The latter element is regarded to be of special interest for the German micro-g community. Until now the implementation of A&R Technologies has not been included as part of the system concept for the COLUMBUS laboratory modules. Yet especially for the Free Flyer, a high degree of A&R will be indispensible. An A&R system concept and implementation options for A&R are given to make the COLUMBUS labs 'intelligent' laboratories in orbit.

  4. 77 FR 62135 - Columbus Day, 2012

    Science.gov (United States)

    2012-10-12

    ... Columbus Day, 2012 By the President of the United States of America A Proclamation As dawn broke over the... spirit that carried Christopher Columbus and his crew from a Spanish port to North America, and we... Americans have summoned the same spirit of discovery that drove Christopher Columbus when he cast off from...

  5. Updates on HRF Payloads Operations in Columbus ATCS

    Science.gov (United States)

    DePalo, Savino; Wright, Bruce D.; La,e Robert E.; Challis, Simon; Davenport, Robert; Pietrafesa, Donata

    2011-01-01

    The NASA developed Human Research Facility 1 (HRF1) and Human Research Facility (HRF2) experiment racks have been operating in the European Space Agency (ESA) Columbus module of the International Space Station (ISS) since Summer 2008. The two racks are of the same design. Since the start of operations, unexpected pressure spikes were observed in the Columbus module's thermal-hydraulic system during the racks activation sequence. The root cause of these spikes was identified in the activation command sequence in the Rack Interface Controller (RIC), which controls the flow of thermal-hydraulic system fluid through the rack. A new Common RIC Software (CRS) release fixed the bug and was uploaded on both racks in late 2009. This paper gives a short introduction to the topic, describes the Columbus module countermeasures to mitigate the spikes, describes the ground validation test of the new software, and describes the flight checks performed before and after the final upload. Finally, the new on-orbit test designed to further simplify the racks hydraulic management is presented.

  6. Host plants, distribution, and ecological association of Hoplolaimus columbus.

    Science.gov (United States)

    Lewis, S A; Smith, F H

    1976-07-01

    Selected species and cultivars of plants were evaluated for host suitability for Hoplolaimus columbus under greenhouse and fieht conditions. Sixteen agronomic plant cultivars were assayed for infection and reproduction after 2-6 months. Lima bean, soybean, cotton, and sweet corn were most favorable for nematode reproduction, whereas sweet potato was a nonhost plant. Field corn and watermelon, which tolerated H. columbus without significant yield losses, are suited for alternative crops in the southern coastal plain. Populations of H. columbus occurred in 15% of soyhean and 25% of cotton soil samples assayed. Population levels of H. columbus and Helicotylenchus spp. were correlated with fluctuations in various soil nutrient factors, whereas Meloidogyne spp. and Scutellonema spp. were not. No correlation was detected between the presence of H. columbus and populations of other nematode genera stndied.

  7. Columbus and the Flat Earth Myth

    Science.gov (United States)

    Singham, Mano

    2007-01-01

    In this article, the author discusses the resilient myth that it was Columbus' journey to the New World that proved that the world was round. It is widely known that it was Columbus' journey to the New World that proved that the world was round. However, Thomas Kuhn in "The Copernican Revolution" showed clearly in 1957 that the idea of a flat…

  8. Advanced power supply and distribution systems for Columbus

    Science.gov (United States)

    Eggers, Gert

    1988-01-01

    The paper describes power supply and distribution systems to be used on unmanned/man-tended Columbus elements, capable of supplying 10 kW to 30 kW to a variety of users in low earth orbits (LEO's). For the definition of the Electrical Power System (EPS) challenging requirements as the provision of high power levels under hard LEO conditions, maintainability, commonality etc. are to be taken into account. These requirements are to be seen in conjunction with the Columbus IOC (initial operational capability) scenario stipulating that EPS hardware shall be used on the Polar Platform, the Pressurized Module attached to the U.S. Space Station and the Man-Tended Free Flier. According to the availability of European technologies, the baseline in the power generation area is a photovoltaic system which provides three regulated main buses (150 V d.c.) to the users. In order to maintain power supply during eclipse phases, nickel hydrogen batteries will be used for energy storage purposes with nickel cadmium as back-up solution. The power distribution system needs special attention. Due to the elevated voltage levels mechanical switch gear cannot be used any longer. It is to be replaced by solid state power controllers (SSPC). Because these devices show a totally different behaviour with regard to conventional relay contacts, new approaches in the area of switching and protection are necessary. In view of the crucial role of this new technology for the realization of medium voltage d.c. systems, it is of great importance for Columbus and, hence will receive adequate consideration in the paper. In order to cater for effective management and control of the power supply and distribution hardware, a so called power system internal data processing assembly (PINDAP) has been introduced in the EPS. PINDAP is the key to reduced dependence on ground stations (alleviated ground support requirements); it keeps crew involvement in the EPS control process to as minimum and provides

  9. Columbus safety and reliability

    Science.gov (United States)

    Longhurst, F.; Wessels, H.

    1988-10-01

    Analyses carried out to ensure Columbus reliability, availability, and maintainability, and operational and design safety are summarized. Failure modes/effects/criticality is the main qualitative tool used. The main aspects studied are fault tolerance, hazard consequence control, risk minimization, human error effects, restorability, and safe-life design.

  10. Decontamination of Battelle-Columbus' Plutonium Facility. Final report

    International Nuclear Information System (INIS)

    Rudolph, A.; Kirsch, G.; Toy, H.L.

    1984-01-01

    The Plutonium Laboratory, owned and operated by Battelle Memorial Institute's Columbus Division, was located in Battelle's Nuclear Sciences area near West Jefferson, Ohio, approximately 17 miles west of Columbus, Ohio. Originally built in 1960 for plutonium research and processing, the Plutonium Laboratory was enlarged in 1964 and again in 1967. With the termination of the Advanced Fuel Program in March, 1977, the decision was made to decommission the Plutonium Laboratory and to decontaminate the building for unrestricted use. Decontamination procedures began in January, 1978. All items which had come into contact with radioactivity from the plutonium operations were cleaned or disposed of through prescribed channels, maintaining procedures to ensure that D and D operations would pose no risk to the public, the environment, or the workers. The entire program was conducted under the cognizance of DOE's Chicago Operations Office. The building which housed the Plutonium Laboratory has now been decontaminated to levels allowing it to house ordinary laboratory and office operations. A ''Finding of No Significant Impact'' (FNSI) was issued in May, 1980

  11. Astronaut training in view of the future: A Columbus payload instructor perspective

    Science.gov (United States)

    Aguzzi, Manuela; Bosca, Riccardo; Müllerschkowski, Uwe

    2010-02-01

    In early 2008 the Columbus module was successfully attached to the ISS. Columbus is the main European contribution to the on-board scientific activity, and is the result of the interdisciplinary effort of European professionals involved from the concept to the utilisation of the laboratory. Astronauts from different Space Agencies have been trained to operate the scientific payloads aboard Columbus, in order to return fundamental data to the scientific community. The aim of this paper is to describe the current activity of the Columbus Payload Training Team (as part of the European Astronaut Centre of ESA) and from this experience derive lessons learned for the future training development, in view of long-term missions. The general structure of the training is described. The Columbus Payload Training Team activity is outlined and the process of the lesson development (Instructional System Design) is briefly described. Finally the features of the training process that can become critical in future scenario are highlighted.

  12. Inelastic analysis of Battelle-Columbus piping elbow creep test

    International Nuclear Information System (INIS)

    Dhalla, A.K.; Newman, S.Z.

    1979-01-01

    Analytical results are presented for room temperature and 593 deg. C creep bending deformation of a piping elbow structure tested at the Battelle-Columbus Laboratory. This analysis was performed in support of the International Piping Benchmark Problem Program being coordinated by ORNL. Results are presented for both simplified and refined structural models, and compared with test measurements reported by the Battelle-Columbus Laboratory. (author)

  13. The End-To-End Safety Verification Process Implemented to Ensure Safe Operations of the Columbus Research Module

    Science.gov (United States)

    Arndt, J.; Kreimer, J.

    2010-09-01

    The European Space Laboratory COLUMBUS was launched in February 2008 with NASA Space Shuttle Atlantis. Since successful docking and activation this manned laboratory forms part of the International Space Station(ISS). Depending on the objectives of the Mission Increments the on-orbit configuration of the COLUMBUS Module varies with each increment. This paper describes the end-to-end verification which has been implemented to ensure safe operations under the condition of a changing on-orbit configuration. That verification process has to cover not only the configuration changes as foreseen by the Mission Increment planning but also those configuration changes on short notice which become necessary due to near real-time requests initiated by crew or Flight Control, and changes - most challenging since unpredictable - due to on-orbit anomalies. Subject of the safety verification is on one hand the on orbit configuration itself including the hardware and software products, on the other hand the related Ground facilities needed for commanding of and communication to the on-orbit System. But also the operational products, e.g. the procedures prepared for crew and ground control in accordance to increment planning, are subject of the overall safety verification. In order to analyse the on-orbit configuration for potential hazards and to verify the implementation of the related Safety required hazard controls, a hierarchical approach is applied. The key element of the analytical safety integration of the whole COLUMBUS Payload Complement including hardware owned by International Partners is the Integrated Experiment Hazard Assessment(IEHA). The IEHA especially identifies those hazardous scenarios which could potentially arise through physical and operational interaction of experiments. A major challenge is the implementation of a Safety process which owns quite some rigidity in order to provide reliable verification of on-board Safety and which likewise provides enough

  14. Elevated indoor radon levels and elevated incidence of lung cancer in Columbus and Franklin County, Ohio: Cause or coincidence?

    International Nuclear Information System (INIS)

    Grafton, H.E.; West, D.R.

    1992-01-01

    Columbus, and Franklin County, Ohio, have been identified as having elevated residential radon levels. Research by the Columbus Health Department, the Ohio Department of Health, and the US Environmental Protection Agency has shown that average screening measurements for the county range from 63% to 73% above 148 Bq m -3 , 23% to 27% above 370 Bq m -3 , and 1% above 1850 Bq m -3 , for both males and females, respectively. The observed cancer rate per 100,000 persons for the period 1979-1986 for the City of Columbus was 62.8 and for the State of Ohio, 49.3, for the bronchi, lungs, and trachea. The reliability of residential radon data, the effect of smoking, mobility of residents, and other confounding factors are referenced. We suggest that while current evidence is insufficient to demonstrate a causal or coincidental relationship between elevated radon levels and higher-than-average rates of lung cancer, the measurement data suggest that Franklin County, Ohio, is an appropriate site for such research

  15. 3 CFR 8437 - Proclamation 8437 of October 9, 2009. Columbus Day, 2009

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Proclamation 8437 of October 9, 2009. Columbus Day... Proc. 8437 Columbus Day, 2009By the President of the United States of America A Proclamation More than... Mexico, explorers of Italian descent have directly influenced the growth of North America. Their...

  16. COLUMBUS as Engineering Testbed for Communications and Multimedia Equipment

    Science.gov (United States)

    Bank, C.; Anspach von Broecker, G. O.; Kolloge, H.-G.; Richters, M.; Rauer, D.; Urban, G.; Canovai, G.; Oesterle, E.

    2002-01-01

    The paper presents ongoing activities to prepare COLUMBUS for communications and multimedia technology experiments. For this purpose, Astrium SI, Bremen, has studied several options how to best combine the given system architecture with flexible and state-of-the-art interface avionics and software. These activities have been conducted in coordination with, and partially under contract of, DLR and ESA/ESTEC. Moreover, Astrium SI has realized three testbeds for multimedia software and hardware testing under own funding. The experimental core avionics unit - about a half double rack - establishes the core of a new multi-user experiment facility for this type of investigation onboard COLUMBUS, which shall be available to all users of COLUMBUS. It allows for the connection of 2nd generation payload, that is payload requiring broadband data transfer and near-real-time access by the Principal Investigator on ground, to test highly interactive and near-realtime payload operation. The facility is also foreseen to test new equipment to provide the astronauts onboard the ISS/COLUMBUS with bi- directional hi-fi voice and video connectivity to ground, private voice coms and e-mail, and a multimedia workstation for ops training and recreation. Connection to an appropriate Wide Area Network (WAN) on Earth is possible. The facility will include a broadband data transmission front-end terminal, which is mounted externally on the COLUMBUS module. This Equipment provides high flexibility due to the complete transparent transmit and receive chains, the steerable multi-frequency antenna system and its own thermal and power control and distribution. The Equipment is monitored and controlled via the COLUMBUS internal facility. It combines several new hardware items, which are newly developed for the next generation of broadband communication satellites and operates in Ka -Band with the experimental ESA data relay satellite ARTEMIS. The equipment is also TDRSS compatible; the open loop

  17. MEAT-GOAT MARKET ANALYSIS: A PILOT STUDY OF THE SOMALI MARKET IN COLUMBUS, OH

    OpenAIRE

    Worley, C. Thomas; Ellerman, John; Mangione, Dave; West, Travis; Yang, Y.

    2004-01-01

    This case study focuses on meat goat marketing involving one distinct immigrant group residing in one area of Columbus, Ohio: the Somalis. There are about 20,000-25,000 Somalis living in Columbus, the second largest concentration of Somalian immigrants in the U.S. after Minneapolis-St. Paul, Minnesota. It is estimated that Columbus Somalis consume the meat from about 14,000 goats each year. The objective of this pilot study is to analyze the meat goat marketing and consumption patterns of the...

  18. Polarized neutrons for Australian scientific research

    International Nuclear Information System (INIS)

    Kennedy, Shane J.

    2005-01-01

    Polarized neutron scattering has been a feature at ANSTO's HIFAR research reactor since the first polarization analysis (PA) spectrometer Longpol began operation over 30 years ago. Since that time, we have improved performance of Longpol and added new capabilities in several reincarnations of the instrument. Most of the polarized neutron experiments have been in the fields of magnetism and superconductivity, and most of that research has involved PA. Now as we plan our next generation neutron beam facility, at the Replacement Research Reactor (RRR), we intend to continue the tradition of PA but with a far broader scope in mind. Our new capabilities will combine PA and energy analysis with both cold and thermal neutron source spectra. We will also provide capabilities for research with polarized neutrons in small-angle neutron scattering and in neutron reflectometry. The discussion includes a brief historical account of the technical developments with a summary of past and present applications of polarized neutrons at HIFAR, and an outline of the polarized neutron capabilities that will be included in the first suite of instruments, which will begin operation at the new reactor in 2006

  19. Goodby Columbus and all that: history and textual criticism

    Directory of Open Access Journals (Sweden)

    Teofilo F. Ruiz

    1993-07-01

    Full Text Available [First paragraph] Columbus. FELIPE FERNANDEZ-ARMESTO. Oxford: Oxford University Press, 1991. xxvii + 218 pp. (Cloth US$ 16.95, Paper US$ 6.99 The Worlds of Christopher Columbus. WILLIAM D. PHILLIPS, JR. & CARLA RAHN PHILLIPS. Cambridge: Cambridge University Press, 1992. xii + 322 pp. (Cloth US$ 27.95 In Search of Columbus: The Sources for the First Voyage. DAVID HENIGE. Tucson: University of Arizona Press, 1991. xiii + 359 pp. (Cloth US$ 29.95 Columbus and the Golden World of the Island Arawaks: The Story of the First Americans and Their Caribbean Environment. D.J.R. WALKER. Kingston, Jamaica: Ian Randle, 1992. 320 pp. (Cloth US$ 12.95 By the time this review appears in print, the Quincentenary celebrations and/or deprecations of the event will be slowly fading into most welcomed oblivion. There will be, of course, the unavoidable local commemorations of specific events: the discovery of such and such island, the anniversary of some European misdeed, the struggle for the valley of Mexico; but the collective remembrance of the Encounter/Discovery will have been allowed to run its course. In truth, after a veritable flood of publications, seminars, operas, protests, and ghastly movies, one is not too sorry to see the whole affair put safely away for another century. If there is any consolation to this continuous process of recovered memories and history, it is that a good number of sensible and scholarly works have been published - including some of those reviewed here - which demolish the idealization and glorification of the Atlantic enterprise and set the history of the Encounter/Discovery within a proper historical context.

  20. 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.

  1. The Columbus-CC—Operating the European laboratory at ISS

    Science.gov (United States)

    Kuch, T.; Sabath, D.

    2008-07-01

    The European ISS Columbus Control Center (Col-CC) joined the club of ISS mission control centers in Moscow, Houston and Huntsville. It took some time to reach that goal. In 1998 the European Space Agency (ESA) awarded the German Aerospace Center DLR to design, develop and implement the Col-CC at its premises in Oberpfaffenhofen, near Munich, Germany. In 2002 a core mission operations team was built up. An integrated team of ESA, industry and control center started to define processes and implemented first operations products and tools. This was accompanied by regular meetings with the international partners in the US and Russia. With intensive training and numerous simulations the team was able to gain experience and is now eagerly waiting for the launch of Columbus. However, thanks to the involvement in some operational activities the Col-CC staff has already been able to gain operational ISS experience. After the inauguration in October 2004 Col-CC supported the Eneide mission in April 2005 when the Italian ESA-Astronaut Roberto Vittori flew onboard a Soyuz to the ISS where he spent 10 days. Another very important milestone was the operations support for ESA's Astrolab mission. The Astrolab mission was of major importance for Europe and particularly for Germany because it implied the first long duration flight of ESA astronaut Thomas Reiter, an astronaut of German nationality. The tasks of Col-CC are described and also the experiences made with the first operational long-term mission which took place from July to December 2006. Meanwhile the Col-CC was able to reach the operational readiness status for the Columbus mission which is set for a launch date later in 2007. Despite the concentration on the challenging Columbus Assembly and Checkout phase emphasis is already laid on the following increments for the European ISS operations. Early 2006 ESA transferred the operational tasks and responsibilities to the hands of the industrial operator. This approach creates

  2. Surface radiological free release program for the Battelle Columbus Laboratory Decommissioning Project

    International Nuclear Information System (INIS)

    Horton, C.N.

    1995-01-01

    This paper was prepared for the Second Residual Radioactivity and Recycling Criteria Workshop and discusses decommissioning and decontamination activities at the Battelle Columbus Laboratories Decommissioning Project (BCLDP). The BCLDP is a joint effort between the Department of Energy (DOE) and Battelle Columbus Operations to decontaminate fifteen Battelle-owned buildings contaminated with DOE radioactive materials. The privately owned buildings located across the street from The Ohio State University campus became contaminated with natural uranium and thorium during nuclear research activities. BCLDP waste management is supported by an extensive radiological free-release program. Miscellaneous materials and building surfaces have been free-released from the BCLDP. The free-release program has substantially reduced radioactive waste volumes and supported waste minimization. Free release for unrestricted use has challenged regulators and NRC licensees since the development of early surface-release criteria. This paper discusses the surface radiological free-release program incorporated by the BCLDP and the historical development of the surface radiological free-release criteria. Concerns regarding radiological free-release criteria are also presented. (author)

  3. 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.

  4. Efficacy of Cotton Root Destruction and Winter Cover Crops for Suppression of Hoplolaimus columbus.

    Science.gov (United States)

    Davis, R F; Baird, R E; McNeil, R D

    2000-12-01

    The efficacy of rye (Secale cereale) and wheat (Triticum aestivum) winter cover crops and cotton stalk and root destruction (i.e., pulling them up) were evaluated in field tests during two growing seasons for Hoplolaimus columbus management in cotton. The effect of removing debris from the field following root destruction also was evaluated. Wheat and rye produced similar amounts of biomass, and both crops produced more biomass (P Cover crops did not suppress H. columbus population levels or increase subsequent cotton yields. Cotton root destruction did not affect cotton stand or plant height the following year. Cotton root destruction lowered (P rye or wheat cover crop or cotton root destruction following harvest is ineffective for H. columbus management in cotton.

  5. Columbus electronic freight management evaluation final report : June 2008.

    Science.gov (United States)

    2008-06-01

    This document provides the independent evaluation of the USDOT-sponsored Columbus Electronic Freight Management (CEFM) Operational Test, which occurred from late May 2007 until December 2007. The Evaluation report includes descriptions of the CEFM sy...

  6. Toward a permanent lunar settlement in the coming decade: the Columbus Project

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R.A.; Ishikawa, M.Y.; Wood, L.L.

    1985-11-19

    The motivation for creating a permanent lunar settlement is sketched, and reasons for doing so in the coming decade are put forward. A basic plan to accomplish this is outlined, along technical and programmatic axes. It is concluded that founding a lunar settlement on the five hundredth anniversary of the Columbus landing - a Columbus Project - could be executed as a volunteer-intensive American enterprise requiring roughly six thousand man-years of skilled endeavor and a total Governmental contribution of the order of a half-billion dollars. 8 figs.

  7. Toward a permanent lunar settlement in the coming decade: the Columbus Project

    International Nuclear Information System (INIS)

    Hyde, R.A.; Ishikawa, M.Y.; Wood, L.L.

    1985-01-01

    The motivation for creating a permanent lunar settlement is sketched, and reasons for doing so in the coming decade are put forward. A basic plan to accomplish this is outlined, along technical and programmatic axes. It is concluded that founding a lunar settlement on the five hundredth anniversary of the Columbus landing - a Columbus Project - could be executed as a volunteer-intensive American enterprise requiring roughly six thousand man-years of skilled endeavor and a total Governmental contribution of the order of a half-billion dollars. 8 figs

  8. Cursory radiological assessment: Battelle Columbus Laboratory Decommissioning and Decontamination Project

    International Nuclear Information System (INIS)

    Smith, W.H.; Munyon, W.J.; Mosho, G.D.; Robinet, M.J.; Wynveen, R.A.

    1988-10-01

    This document reports on the results obtained from a cursory radiological assessment of various properties at the Battelle Columbus Laboratory, Columbia, Ohio. The cursory radiological assessment is part of a preliminary investigation for the Battelle Columbus Laboratory Decommissioning and Decontamination Project. The radiological assessment of Battelle Columbus Laboratory's two sites included conducting interior and exterior building surveys and collecting and analyzing air, sewer system, and soil samples. Direct radiological surveys were made of floor, wall, and overhead areas. Smear surveys were made on various interior building surfaces as well as the exterior building vents. Air samples were collected in select areas to determine concentrations of Rn-222, Rn-220, and Rn-219 daughters, in addition to any long-lived radioactive particulates. Radon-222 concentrations were continuously monitored over a 24-hr period at several building locations using a radon gas monitoring system. The sanitary sewer systems at King Avenue, West Jefferson-North, and West Jefferson-South were each sampled at select locations. All samples were submitted to the Argonne Analytical Chemistry Laboratory for various radiological and chemical analyses. Environmental soil corings were taken at both the King Avenue and West Jefferson sites to investigate the potential for soil contamination within the first 12-inches below grade. Further subsurface investigations at the West Jefferson-North and West Jefferson-South areas were conducted using soil boring techniques. 4 refs., 10 figs., 10 tabs

  9. 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

  10. Arctic Forecasts Available from Polar Bear Exhibit as an Example of Formal/Informal Collaboration

    Science.gov (United States)

    Landis, C. E.; Cervenec, J.

    2012-12-01

    A subset of the general population enjoys and frequents informal education venues, offering an opportunity for lifelong learning that also enhances and supports formal education efforts. The Byrd Polar Research Center (BPRC) at The Ohio State University collaborated with the Columbus Zoo & Aquarium (CZA) in the development of their Polar Frontier exhibit, from its initial planning to the Grand Opening of the exhibit, through the present. Of course, the addition to the Zoo of polar bears and Arctic fox in the Polar Frontier has been very popular, with almost a 7% increase in visitors in 2010 when the exhibit opened. The CZA and BPRC are now investigating ways to increase the climate literacy impact of the exhibit, and to increase engagement with the topics through follow-on activities. For example, individuals or classes anywhere in the world can check forecasts from the Polar Weather and Research Forecasting model and compare them to observed conditions-- allowing deep investigation into changes in the Arctic. In addition, opportunities exist to adapt the Zoo School experience (affecting several Central Ohio school districts) and/or to enable regular participation through social media such as Facebook, Twitter, and other forms of digital communication. BPRC's sustained engagement with the CZA is an example of a trusted and meaningful partnership where open dialogue exists about providing the best learning experience for visitors. This presentation will share some of the lessons learned from this unique partnership, and strategies that are adopted to move it forward.

  11. 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

  12. The Columbus Knee System: 4-Year Results of a New Deep Flexion Design Compared to the NexGen Full Flex Implant

    Directory of Open Access Journals (Sweden)

    D. Goebel

    2012-01-01

    Full Text Available The Columbus knee system is designed as a standard knee implant to allow high flexion without additional bone resection. Between August, 2004 and March, 2010 we performed 109 total knee arthroplasties of the Columbus knee system in 101 consecutive patients suffering from primary arthrosis of the knee. Mean age was 72.4 years in women and 70.3 years in men. Mean followup was 47.3 months. The 4-year results of a group of patients who received the NexGen Full Flex implant operated by the same surgeon were used for comparison. Mean total knee score was Columbus: 175.6 and NexGen Flex: 183.4; =0.037. Mean operation time was 53 min for Columbus and 66 min for NexGen Flex; 0.05. Radiological assessment showed no signs of loosening for both groups. Therefore, the Columbus knee system can be recommended for flexion angles up to 140∘.

  13. Outsourcing of Defense Supply Center, Columbus, Bus and Taxi Service Operations

    National Research Council Canada - National Science Library

    Granetto, Paul

    1999-01-01

    Introduction. We performed the audit in response to allegations to the Defense Hotline that the Defense Supply Center, Columbus, outsourcing study for bus and taxi service operations was based on incorrect methodology...

  14. Flood-inundation maps for the East Fork White River at Columbus, Indiana

    Science.gov (United States)

    Lombard, Pamela J.

    2013-01-01

    Digital flood-inundation maps for a 5.4-mile reach of the East Fork White River at Columbus, Indiana, from where the Flatrock and Driftwood Rivers combine to make up East Fork White River to just upstream of the confluence of Clifty Creek with the East Fork White River, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at USGS streamgage 03364000, East Fork White River at Columbus, Indiana. Current conditions at the USGS streamgage may be obtained on the Internet from the USGS National Water Information System (http://waterdata.usgs.gov/in/nwis/uv/?site_no=03364000&agency_cd=USGS&). The National Weather Service (NWS) forecasts flood hydrographs for the East Fork White River at Columbus, Indiana at their Advanced Hydrologic Prediction Service (AHPS) flood warning system Website (http://water.weather.gov/ahps/), that may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relation at USGS streamgage 03364000, East Fork White River at Columbus, Indiana. The calibrated hydraulic model was then used to determine 15 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data), having a 0.37-ft vertical accuracy and a 1.02 ft

  15. Payroll Expenses Reported by the Defense Finance and Accounting Service Columbus Center

    National Research Council Canada - National Science Library

    1998-01-01

    .... Specifically, we reviewed accounting records for payroll and related expenditures to determine the validity of payroll expenses that the DFAS Columbus Center submitted to the DFAS Indianapolis Center...

  16. Downlight Demonstration Program: Hilton Columbus Downtown

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Robert G.; Perrin, Tess E.

    2014-05-13

    The U.S. Department of Energy (DOE) estimates that there were about 700 million downlight luminaires installed in residential and commercial buildings in the U.S. as of 2012, with light-emitting diode (LED) luminaires representing less than 1% of this installed base. Downlight luminaires using conventional incandescent, halogen, and compact fluorescent lamps have lower efficacies and shorter expected lifetimes than comparable LED systems, but the lower initial cost of the conventional technology and the uncertainties associated with the newer LED technology have restricted widespread adoption of LED downlight luminaires. About 278 tBtu of energy could be saved annually if LED luminaires were to saturate the downlight market, equating to an annual energy cost savings of $2.6 billion. This report summarizes an evaluation of LED recessed downlight luminaires in the guest rooms at the Hilton Columbus Downtown hotel in Columbus, OH. The facility opened in October of 2012, and the U.S. Department of Energy (DOE) conducted a post-occupancy assessment of the facility in January–March of 2014. Each of the 484 guest rooms uses seven 15 W LED downlights: four downlights in the entry and bedroom and three downlights in the bathroom. The 48 suites use the seven 15 W LED downlights and additional fixtures depending on the space requirements, so that in total the facility has more than 3,700 LED downlights. The downlights are controlled through wall-mounted switches and dimmers. A ceiling-mounted vacancy sensor ensures that the bathroom luminaires are turned off when the room is not occupied.

  17. Fundamental research with polarized slow neutrons

    International Nuclear Information System (INIS)

    Krupchitsky, P.A.

    1987-01-01

    In the last twenty years polarized beams of slow neutrons have been used effectively in fundamental research in nuclear physics. This book gives a thorough introduction to these experimental methods including the most recent techniques of generating and analyzing polarized neutron beams. It clearly shows the close relationship between elementary particle physics and nuclear physics. The book not only addresses specialists but also those interested in the foundations of elementary particle and nuclear physics. With 42 figs

  18. An Innovative Virtual Training Simulator for Columbus Astronauts

    Science.gov (United States)

    Risola, F.; Morzuch, G.

    2004-06-01

    The International Space Station (ISS) is a co-operative programme among the main world space agencies. The European Space Agency contribution is the Automated Transfer Vehicle and the Columbus Orbital Facility, which is the European laboratory of the ISS. It provides a pressurized environment to house up to ten payload racks containing scientific instruments for the conduct of a broad band of experiments. The astronauts on-board of the ISS interact with the payloads for the preparation and execution of the experiments and before their expedition, they have to train on ground in the most realistic manner. The training is carried out at the European Astronauts Centre in the Columbus Trainer, a complex facility that reproduces the physical layout of the ISS European laboratory and a set of payload racks simulators. These simulators are being developed by Dataspazio with an innovative low-cost approach combining the high realism of the simulation with the flexibility and re-usability of the payloads simulators. The hearth of this approach is the interactive payload Virtual Front-panel Interface. The development of these high-realism training payload simulators incorporate several technological issues such as Digital Light ProcessingTM, projected capacitance touch-screen, high-fidelity graphics and simulation software.

  19. Cosmic radiation shielding properties of COLUMBUS and REMSIM multi-layer external shells

    Science.gov (United States)

    Durante, Marco; Manti, Lorenzo; Rusek, Adam; Belluco, Maurizio; Lobascio, Cesare

    The European module COLUMBUS has been recently installed on the International Space Station. Future plans for exploration involve the use of inflatable modules, such as the REMSIM concept proposed in a previous ESA funded study. We studied the radiation shielding properties of COLUMBUS and REMSIM external shell using 1 GeV/n Feor H-ions accelerated at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory (Long Island, NY, USA). COLUMBUS has a 22 mm rigid multi-layer shell with Al, Nextel and Kevlar, as materials of the double bumper for meteoroids and debris protection, MLI for thermal reasons and again Al as pressure shell. Inside the module, astronauts are further protected by secondary structures, including racks, a number of electronic devices and payload equipment. This internal equipment has been simulated using Al and Kevlar, bringing the total thickness to about 15 g/cm2. REMSIM consists of a thermal multi-layer (MLI), four Nextel layers used to provide shock of the impacting micro-meteoroids, a ballistic restraint multi-layer of Kevlar used to absorb debris cloud's kinetic energy, a Kevlar structural restraint to support pressure loads incurred from inflating the module. To contain air inside the module, REMSIM adopts three layers of airtight material separated by two layers of Kevlar (air bladder). A final layer of Nomex provide protection against punctures and fire. In the flight configuration there are also spacer elements (foam) needed to guarantee correct spacing between consecutive bumper layers. These spacers were not included in the tests, making the total thickness about 1.1 cm. The internal equipment in REMSIM was not been defined, but due to its application for exploration missions it was decided to exploit water, valuable resource used for drinking, washing and technical usage, as a radiation shielding. In this test, we have included about 8 cm of water. Measured dose attenuation shows that the Columbus module reduces the

  20. Promoting active transportation as a partnership between urban planning and public health: the columbus healthy places program.

    Science.gov (United States)

    Green, Christine Godward; Klein, Elizabeth G

    2011-01-01

    Active transportation has been considered as one method to address the American obesity epidemic. To address obesity prevention through built-environment change, the local public health department in Columbus, Ohio, established the Columbus Healthy Places (CHP) program to formally promote active transportation in numerous aspects of community design for the city. In this article, we present a case study of the CHP program and discuss the review of city development rezoning applications as a successful strategy to link public health to urban planning. Prior to the CHP review, 7% of development applications in Columbus included active transportation components; in 2009, 64% of development applications adopted active transportation components specifically recommended by the CHP review. Active transportation recommendations generally included adding bike racks, widening or adding sidewalks, and providing sidewalk connectivity. Recommendations and lessons learned from CHP are provided.

  1. Military Construction of the Defense Finance and Accounting Service Operations Facility, Columbus, Ohio

    National Research Council Canada - National Science Library

    Granetto, Paul

    1995-01-01

    The audit objectives were to determine whether the Defense Finance and Accounting Service Columbus Center properly planned and programmed the FY 1996 proposed military construction project and whether...

  2. 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.

  3. Research Activity and Infrastructure of Korea Polar Research Institute: Current and Future Perspectives

    Science.gov (United States)

    Jin, D.; Kim, S.; Lee, H.

    2011-12-01

    The Korea Polar Research Institute (KOPRI) opened the Antarctic King Sejong research station in 1988 at the King George Island off the Antarctic Peninsula and started the polar research mainly in the fields of biology and geology with some atmosphere observations. To extend the view of polar research, the KOPRI opened the Arctic Dasan research station at Ny-Alesund, Spitsbergen Island in 2002 and has studied the rapid climate change diagnostics and some microbiological observation. The KOPRI is now expanding the Arctic research into Alaska and Canada under the international collaboration, and planning to outreach to Russia to monitor the change in permafrost and to understand its impact on global warming. To deepen the views of polar research including the ice covered oceans in both poles, the ice-breaking vessel, the ARAON of about 7000 ton, was launched recently and successfully finished the Arctic and Antarctic cruises for research activity on all perspectives of ocean sciences and support for the King Sejong station. The KOPRI is now building another Antarctic research station, called Jangbogo, at the Terra Nova Bay off the Ross Sea and plan to open the station at the March of 2014. By building the second Antarctic station together with the ARAON, the KOPRI will focus its research on understanding the rapid climate change in west Antarctica such as to monitor the calving of the Larsen Ice shelf, rapid melting of Pine Island Glacier, and upper atmosphere, to study the sea ice and ecosystem change in the Amundsen Sea and the role of the southern annular mode in the west Antarctic warming, upper atmosphere and climate change, to reconstruct paleoclimate records from ice and sediment cores.

  4. Connecting polar research to NGSS STEM classroom lessons

    Science.gov (United States)

    Brinker, R.; Kast, D.

    2016-12-01

    Next Generation Science Standards (NGSS) are designed to bring consistent, rigorous science teaching across the United States. Topics are categorized as Performance Expectations (PE), Disciplinary Core Ideas (DCI), Cross-Cutting Concepts (CCC), and Science and Engineering Practices (SEP). NGSS includes a focus on environmental science and climate change across grade levels. Earth and planetary sciences are required at the high school level. Integrating polar science lessons into NGSS classrooms brings relevant, rigorous climate change curriculum across grade levels. Polar science provides opportunities for students to use current data during lessons, conduct their own field work, and collaborate with scientists. Polar science provides a framework of learning that is novel to most students. Inquiry and engagement are high with polar science lessons. Phenomenon related to polar science provide an excellent tool for science teachers to use to engage students in a lesson, stimulate inquiry, and promote critical thinking. When taught effectively, students see the connections between their community, polar regions and climate change, regardless of where on the planet students live. This presentation describes examples of how to effectively implement NGSS lessons by incorporating polar science lessons and field research. Examples of introductory phenomenon and aligned PEs, CCCs, DCIs, and SEPs are given. Suggested student activities, assessments, examples of student work, student research, labs, and PolarTREC fieldwork, use of current science data, and connections to scientists in the field are provided. The goals of the presentation are to give teachers a blueprint to follow when implementing NGSS lessons, and give scientists an understanding of the basics of NGSS so they may be better able to relate their work to U.S. science education and be more effective communicators of their science findings.

  5. “Pre-Columbus Voyage by Chinese"——Great Navigator Zheng He

    Institute of Scientific and Technical Information of China (English)

    Manfield Zhu

    2003-01-01

    <正> "British amateur historian Gavin Menzies received a book contract Tuesday for the publication of new theory that a Chinese admiral with a fleet of 100 ships beat Columbus to America and circumnavigated the globe almost a century before Magellan."

  6. "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

  7. Neutron polarizing set-up of the Sofia IRT research reactor

    International Nuclear Information System (INIS)

    Krezhov, K.; Mikhajlova, V.; Okorokov, A.

    1990-01-01

    Neutron polarizing set-up of one of the horizontal beam tubes of the IRT-200 research reactor of the Bulgarian Institute of Nuclear Research and Nuclear Energy is presented. Neutron mirrors are extensively used in an effort to compensate the moderate reactor beam intensity by the high reflected intensity and wide-band transmittance of the mirror neutron guides. Time-to-flight technique using a slotted neutron absorbing chopper with a horizontal rotation axis has been applied to obtain the exit neutron spectra. Beam polarization and flipping ratios have been determined. Cadmium ratio in the polarized beam has been found almost 10 4 and the average polarization has been measured to be higher than 96%. 3 figs, 3 refs

  8. Columbus stowage optimization by cast (cargo accommodation support tool)

    Science.gov (United States)

    Fasano, G.; Saia, D.; Piras, A.

    2010-08-01

    A challenging issue related to the International Space Station utilization concerns the on-board stowage, implying a strong impact on habitability, safety and crew productivity. This holds in particular for the European Columbus laboratory, nowadays also utilized to provide the station with logistic support. The volume exploitation has to be maximized, in compliance with the given accommodation rules. At each upload step, the stowage problem must be solved quickly and efficiently. This leads to the comparison of different scenarios to select the most suitable one. Last minute upgrades, due to possible re-planning, may, moreover arise, imposing the further capability to rapidly readapt the current solution to the updated status. In this context, looking into satisfactory solutions represents a very demanding job, even for experienced designers. Thales Alenia Space Italia has achieved a remarkable expertise in the field of cargo accommodation and stowage. The company has recently developed CAST, a dedicated in-house software tool, to support the cargo accommodation of the European automated transfer vehicle. An ad hoc version, tailored to the Columbus stowage, has been further implemented and is going to be used from now on. This paper surveys the on-board stowage issue, pointing out the advantages of the proposed approach.

  9. 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

  10. 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

  11. Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

    Science.gov (United States)

    Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

    2013-01-01

    Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

  12. Archive of information about geological samples available for research from the Ohio State University Byrd Polar and Climate Research Center (BPCRC) Polar Rock Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Polar Rock Repository (PRR) operated by the Byrd Polar and Climate Research Center (BPCRC) at the Ohio State University is a partner in the Index to Marine and...

  13. Guest Room Lighting at the Hilton Columbus Downtown

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-06-30

    At the Hilton Columbus Downtown hotel in Ohio, DOE's Better Buildings Alliance conducted a demonstration of Next Generation Luminaires-winning downlights installed in all guest rooms and suites prior to the hotel's 2012 opening. After a post-occupancy assessment, the LED downlights not only provided the aesthetic appearance and dimming functionality desired, but also provided 50% energy savings relative to a comparable CFL downlight and enabled the lighting power to be more than 20% below that allowed by code. This document is a summary case study of the report.

  14. In the footsteps of Columbus European missions to the International Space Station

    CERN Document Server

    O'Sullivan, John

    2016-01-01

    The European Space Agency has a long history of cooperating with NASA in human spaceflight, having developed the Spacelab module for carrying in the payload bay of the Space Shuttle. This book tells of the development of ESA’s Columbus microgravity science laboratory of the International Space Station and the European astronauts who work in it. From the beginning, ESA has been in close collaboration on the ISS, making a significant contribution to the station hardware. Special focus is given to Columbus and Copula as well as station resupply using the ATV. Each mission is also examined individually, creating a comprehensive picture of ESA's crucial involvement over the years. Extensive use of color photographs from NASA and ESA to depict the experiments carried out, the phases of the ISS construction, and the personal stories of the astronauts in space highlights the crucial European work on human spaceflight.

  15. 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

  16. Indoor radon levels in Columbus and Franklin county, Ohio residences, commercial buildings, and schools

    International Nuclear Information System (INIS)

    Grafton, H.E.

    1990-01-01

    In this paper data is presented for 2 residential radon surveys, one survey of city-owned buildings, and survey of Columbus Public Schools. The first residential survey used volunteer participants and employed a 48 hour activated carbon measurement: 4425 measurements in the data. The second survey consisted of 120 randomly selected residences in which alpha track detectors were placed for from 60 to 120 days. A survey of 52 city-owned buildings in which screening measurements were obtained using activated carbon, alpha track, and E-PERM radon detectors is included in the data. Also a survey of 25 Columbus Public Schools in which E-PERM radon monitors were used to obtain measurements is detailed in the data. More than 72% of the volunteer survey residences showed screening measurements of 4.0 pCi/L or greater while the random survey revealed 92% of the residences with radon levels of 4.0 pCi/L or higher. Schools tested in the survey also showed elevated radon levels with 20% of the tested structures with an average radon level of 4.0 pCi/L. Work is still in progress on city-owned buildings and Columbus Schools. The authors conclude that any owner or lessor of occupied buildings in Franklin County, Ohio should perform screening measurements and should be prepared to also perform follow-up measurements

  17. An early note on the occurrence of the Magnificent Frigate Bird, Fregata magnificens Mathews, 1914, in the Cape Verde Islands: Columbus as an ornithologist

    NARCIS (Netherlands)

    Hartog, den J.C.

    1993-01-01

    The importance of ornithological observations with respect to Columbus' discovery of America as recorded in the "Diario del descubrimiento" is recognized. The fact that his first and crucial crossing of the Atlantic coincided with the autumn migration may have contributed to its success. Columbus'

  18. Wild-type food in health promotion and disease prevention: the Columbus Concept

    National Research Council Canada - National Science Library

    Meester, Fabien De; Watson, Ronald R. (Ronald Ross)

    2008-01-01

    ... the expected benefits of the former versus the latter regarding quality of life. The leading market concept behind the rehabilitation of dietary/blood cholesterol is called "Columbus." Obviously, it borrows the significance of the name from the time when the earth was proven round rather than flat, and a dramatic leap was made in the way ...

  19. 76 FR 41855 - Columbus Geographic Systems (GIS) Ltd.; Order of Suspension of Trading

    Science.gov (United States)

    2011-07-15

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Columbus Geographic Systems (GIS) Ltd.; Order of Suspension of Trading July 13, 2011. It appears to the Securities and Exchange Commission that... Systems (GIS) Ltd. because it has not filed any periodic reports since the period ended June 30, 2008. The...

  20. 77 FR 62437 - Regulated Navigation Area; Columbus Day Weekend, Biscayne Bay, Miami, FL

    Science.gov (United States)

    2012-10-15

    ... Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking RNA Regulated Navigation Area I. Regulatory History and Information On July 25, 2012, we published a Notice of... Bay Columbus Day regulated navigation area (RNA), established in 2011 and contained in 33 CFR 165.779...

  1. Next Generation Luminaire (NGL) Downlight Demonstration Project, Hilton Columbus Downtown

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R. G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Perrin, T. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-30

    At the Hilton Columbus Downtown hotel in Ohio, DOE's Better Buildings Alliance conducted a demonstration of Next Generation Luminaires-winning downlights installed in all guest rooms and suites prior to the hotel's 2012 opening. After a post-occupancy assessment, the LED downlights not only provided the aesthetic appearance and dimming functionality desired, but also provided 50% energy savings relative to a comparable CFL downlight and enabled the lighting power to be more than 20% below that allowed by code.

  2. DOSIS & DOSIS 3D: long-term dose monitoring onboard the Columbus Laboratory of the International Space Station (ISS

    Directory of Open Access Journals (Sweden)

    Berger Thomas

    2016-01-01

    Full Text Available The radiation environment encountered in space differs in nature from that on Earth, consisting mostly of highly energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones present on Earth for occupational radiation workers. Since the beginning of the space era, the radiation exposure during space missions has been monitored with various active and passive radiation instruments. Also onboard the International Space Station (ISS, a number of area monitoring devices provide data related to the spatial and temporal variation of the radiation field in and outside the ISS. The aim of the DOSIS (2009–2011 and the DOSIS 3D (2012–ongoing experiments was and is to measure the radiation environment within the European Columbus Laboratory of the ISS. These measurements are, on the one hand, performed with passive radiation detectors mounted at 11 locations within Columbus for the determination of the spatial distribution of the radiation field parameters and, on the other, with two active radiation detectors mounted at a fixed position inside Columbus for the determination of the temporal variation of the radiation field parameters. Data measured with passive radiation detectors showed that the absorbed dose values inside the Columbus Laboratory follow a pattern, based on the local shielding configuration of the radiation detectors, with minimum dose values observed in the year 2010 of 195–270 μGy/day and maximum values observed in the year 2012 with values ranging from 260 to 360 μGy/day. The absorbed dose is modulated by (a the variation in solar activity and (b the changes in ISS altitude.

  3. Aerial gamma-ray and magnetic survey, Columbus Quadrangle, Ohio. Final report

    International Nuclear Information System (INIS)

    1981-07-01

    The Columbus quadrangle covers a 7100 square mile area of south central Ohio which is located within the Midwestern Physiographic Province. Up to 6000 feet of Paleozoic strata overlie the east dipping Precambrian basement. Flat lying Quaternary glacial sediments cover a large part of the surface in the north and west regions of the quadrangle. A search of available literature revealed no known uranium deposits. Ninety-nine uranium anomalies were detected and are disussed briefly. Radiometric data reflect the presence of two zones of higher than average uranium anomaly occurrences. One zone is the northerly continuation of a trend observed in a contiguous quadrangle and occurs over undifferentiated Devonian and Mississippian sediments. Some anomalies appear to be culturally induced such as those in the vicinity of the city of Columbus. The outlined area in Figure 3 (indicated by a dashed contour line) should be considered for further investigation. The magnetic data indicate more structural complexity in underlying rocks than inferred by the structural interpretation of the area. The broad zones with long wavelength magnetic signatures on the east are interrupted further west by many small magnetic features whose sources may be attributed to undefined lithologic and/or structural elements in the Precambrian basement

  4. Supply Inventory Management: Evaluation of the Defense Supply Center Columbus Qualified Products List and Qualified Manufacturers List Program

    National Research Council Canada - National Science Library

    2002-01-01

    ... was transitioned from the Military Departments. The Defense Supply Center Columbus currently has management responsibility for over 300 Qualified Products Lists and 4 Qualified Manufacturers Lists...

  5. PolarTREC-Teachers and Researchers Exploring and Collaborating: Science Education from the Poles to the World

    Science.gov (United States)

    Warnick, W. K.; Breen, K.; Warburton, J.; Fischer, K.; Wiggins, H.; Owens, R.; Polly, B.; Wade, B.; Buxbaum, T.

    2007-12-01

    PolarTREC-Teachers and Researchers Exploring and Collaborating is a three-year (2007-2009) teacher professional development program celebrating the International Polar Year (IPY) that advances polar science education by bringing K-12 educators and polar researchers together in hands-on field experiences in the Arctic and Antarctic. Currently in its second year, the program fosters the integration of research and education to produce a legacy of long-term teacher-researcher collaborations, improved teacher content knowledge through experiences in scientific inquiry, and broad public interest and engagement in polar science. Through PolarTREC, over 40 U.S. teachers will spend two to six weeks in the Arctic or Antarctic, working closely with researchers in the field as an integral part of the science team. Research projects focus on a wide range of IPY science themed topics such as sea-ice dynamics, terrestrial ecology, marine biology, atmospheric chemistry, and long-term climate change. While in the field, teachers and researchers will communicate extensively with their colleagues, communities, and hundreds of students of all ages across the globe, using a variety of tools including satellite phones, online journals, podcasts and interactive "Live from IPY" calls and web-based seminars. The online outreach elements of the project convey these experiences to a broad audience far beyond the classrooms of the PolarTREC teachers. In addition to field research experiences, PolarTREC will support teacher professional development and a sustained community of teachers, scientists, and the public through workshops, Internet seminars, an e-mail listserve, and teacher peer groups. To learn more about PolarTREC visit the website at: http://www.polartrec.com or contact info@polartrec.com or 907-474-1600. PolarTREC is funded by NSF and managed by the Arctic Research Consortium of the US (ARCUS).

  6. Tracer-tracer relations as a tool for research on polar ozone loss

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rolf

    2010-07-01

    The report includes the following chapters: (1) Introduction: ozone in the atmosphere, anthropogenic influence on the ozone layer, polar stratospheric ozone loss; (2) Tracer-tracer relations in the stratosphere: tracer-tracer relations as a tool in atmospheric research; impact of cosmic-ray-induced heterogeneous chemistry on polar ozone; (3) quantifying polar ozone loss from ozone-tracer relations: principles of tracer-tracer correlation techniques; reference ozone-tracer relations in the early polar vortex; impact of mixing on ozone-tracer relations in the polar vortex; impact of mesospheric intrusions on ozone-tracer relations in the stratospheric polar vortex calculation of chemical ozone loss in the arctic in March 2003 based on ILAS-II measurements; (4) epilogue.

  7. 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

  8. Research progress on polar lipids of deinococcus radiodurans

    International Nuclear Information System (INIS)

    Feng Qiong; Tian Bing; Hua Yuejin

    2013-01-01

    Deinococcus radiodurans is extremely resistant to radiation, desiccation, oxidizing agents and other extreme conditions. One of the unique lipids in Deinococcus radiodurans is the polar lipid phosphoglycolipid with alkylamine as the main component. Alkylamine derived from fatty acids. The composition characteristic of lipids is one of the classification criterias of Deinococcus. This article provided an overview of the main features of the Deinococcus radiodurans and introduced special polar lipids that have been found as well as the taxonomy significances of such lipids. The research progress of the relationship between lipids and their resistance mechanisms and the prospects of special lipids in Deinococcus radidurans have also been discussed. (authors)

  9. Carbon and hydrogen isotopic variations of natural gases in the southeast Columbus basin offshore southeastern Trinidad, West Indies - clues to origin and maturity

    International Nuclear Information System (INIS)

    Norville, Giselle A.; Dawe, Richard A.

    2007-01-01

    Natural gas can have two distinct origins, biogenic and thermogenic sources. This paper investigates the types and maturities of natural gas present in the SE Columbus basin, offshore Trinidad. The chemical composition and the isotope ratios of C and H were determined for approximately 100 samples of natural gas from eight areas within the SE Columbus basin. These compositions and isotopic data are interpreted to identify the origins of gas (biogenic, thermogenic) and maturity. The data showed that the gases in the SE Columbus basin are of both biogenic and thermogenic origin with a trend of mainly thermogenic to mixed to biogenic when moving from SW to NE across the basin. This trend suggests differential burial of the source rock. The presence of mixed gas indicates there was migration of gas in the basin resulting in deeper thermogenic gas mixing with shallow biogenic gas

  10. "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

  11. Rapid prototyping, astronaut training, and experiment control and supervision: distributed virtual worlds for COLUMBUS, the European Space Laboratory module

    Science.gov (United States)

    Freund, Eckhard; Rossmann, Juergen

    2002-02-01

    In 2004, the European COLUMBUS Module is to be attached to the International Space Station. On the way to the successful planning, deployment and operation of the module, computer generated and animated models are being used to optimize performance. Under contract of the German Space Agency DLR, it has become IRF's task to provide a Projective Virtual Reality System to provide a virtual world built after the planned layout of the COLUMBUS module let astronauts and experimentators practice operational procedures and the handling of experiments. The key features of the system currently being realized comprise the possibility for distributed multi-user access to the virtual lab and the visualization of real-world experiment data. Through the capabilities to share the virtual world, cooperative operations can be practiced easily, but also trainers and trainees can work together more effectively sharing the virtual environment. The capability to visualize real-world data will be used to introduce measured data of experiments into the virtual world online in order to realistically interact with the science-reference model hardware: The user's actions in the virtual world are translated into corresponding changes of the inputs of the science reference model hardware; the measured data is than in turn fed back into the virtual world. During the operation of COLUMBUS, the capabilities for distributed access and the capabilities to visualize measured data through the use of metaphors and augmentations of the virtual world may be used to provide virtual access to the COLUMBUS module, e.g. via Internet. Currently, finishing touches are being put to the system. In November 2001 the virtual world shall be operational, so that besides the design and the key ideas, first experimental results can be presented.

  12. PolarTREC-Teachers and Researchers Exploring and Collaborating: Innovative Science Education from the Poles to the World

    Science.gov (United States)

    Warnick, W. K.; Warburton, J.; Breen, K.; Wiggins, H. V.; Larson, A.; Behr, S.

    2006-12-01

    PolarTREC-Teachers and Researchers Exploring and Collaborating is a three-year (2007-2009) teacher professional development program celebrating the International Polar Year (IPY) that will advance polar science education by bringing K-12 educators and polar researchers together in hands-on field experiences in the Arctic and Antarctic. PolarTREC builds on the strengths of the existing TREC program in the Arctic, an NSF supported program managed by the Arctic Research Consortium of the US (ARCUS), to embrace a wide range of activities occurring at both poles during and after IPY. PolarTREC will foster the integration of research and education to produce a legacy of long-term teacher-researcher collaborations, improved teacher content knowledge through experiences in scientific inquiry, and broad public interest and engagement in polar science and IPY. PolarTREC will enable thirty-six teachers to spend two to six weeks in the Arctic or Antarctic, working closely with researchers investigating a wide range of IPY science themed topics such as sea-ice dynamics, terrestrial ecology, marine biology, atmospheric chemistry, and long-term climate change. While in the field, teachers and researchers will communicate extensively with their colleagues, communities, and hundreds of students of all ages across the globe, using a variety of tools including satellite phones, online journals, podcasts and interactive "Live from IPY" calls and web-based seminars. The online outreach elements of the project convey these experiences to a broad audience far beyond the classrooms of the PolarTREC teachers. In addition to field research experiences, PolarTREC will support teacher professional development and a sustained community of teachers, scientists, and the public through workshops, Internet seminars, an e-mail listserve, and teacher peer groups. For further information on PolarTREC, contact Wendy Warnick, ARCUS Executive Director at warnick@arcus.org or 907-474-1600 or visit www.arcus.org/trec/

  13. PolarTREC-Teachers and Researchers Exploring and Collaborating: Science Education from the Poles to the World

    Science.gov (United States)

    Timm, K. M.; Warburton, J.; Owens, R.; Warnick, W. K.

    2008-12-01

    PolarTREC--Teachers and Researchers Exploring and Collaborating, a program of the Arctic Research Consortium of the U.S. (ARCUS), is a National Science Foundation (NSF)--funded International Polar Year (IPY) project in which K-12 educators participate in hands-on field experiences, working closely with IPY scientists as a pathway to improving science education. PolarTREC has developed a successful internet-based platform for teachers and researchers to interact and share their diverse experiences and expertise by creating interdisciplinary educational tools including online journals and forums, real-time Internet seminars, lesson plans, activities, audio, and other educational resources that address a broad range of scientific topics. These highly relevant, adaptable, and accessible resources are available to educators across the globe and have connected thousands of students and citizens to the excitement of polar science. By fostering the integration of research and education and infusing education with the thrill of discovery, PolarTREC will produce a legacy of long-term teacher-researcher collaborations and increased student knowledge of and interest in the polar regions well beyond the IPY time period. Educator and student feedback from preliminary evaluations has shown 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 in today's world, as well as increased self-reported knowledge and interest in Science, Technology, Engineering, and Mathematics content areas. PolarTREC provides a tested approach and a clear route for researcher participation in the education community

  14. Flood-inundation maps for the Flatrock River at Columbus, Indiana, 2012

    Science.gov (United States)

    Coon, William F.

    2013-01-01

    Digital flood-inundation maps for a 5-mile reach of the Flatrock River on the western side of Columbus, Indiana, from County Road 400N to the river mouth at the confluence with Driftwood River, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ and the Federal Flood Inundation Mapper Web site at http://wim.usgs.gov/FIMI/FloodInundationMapper.html, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Flatrock River at Columbus (station number 03363900). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service, which also presents the USGS data, at http:/water.weather.gov/ahps/. Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at the Flatrock River streamgage, high-water marks that were surveyed following the flood of June 7, 2008, and water-surface profiles from the current flood-insurance study for the City of Columbus. The hydraulic model was then used to compute 12 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from 9 ft or near bankfull to 20 ft, which exceeds the stages that correspond to both the estimated 0.2-percent annual exceedance probability flood (500-year recurrence interval flood) and the maximum recorded peak flow. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from Light Detection and Ranging (LiDAR) data having a 0.37 ft

  15. 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

  16. POLAR-PALOOZA Polar Researchers and Arctic Residents Engage, Inform and Inspire Diverse Public Audiences by sharing Polar Science and Global Connections during the International Polar Year, using a New Model of Informal Science Education

    Science.gov (United States)

    Haines-Stiles, G.; Akuginow, E.

    2006-12-01

    (Please note that the POLAR-PALOOZA initiative described in this Abstract is-as of 9/7/2006-"pending" for possible support from NSF and NASA as part of this year's IPY solicitation. Subject to decisions expected by 9/30, this presentation would either be withdrawn, or amplified with specific participants, locations and dates.) Despite the success of well-regarded movies like "March of the Penguins", the polar regions remain a great unknown for most people. Public knowledge about the Arctic and Antarctic, and the critical role of the Poles in the entire Earth system, is nonexistent, incomplete or burdened with misperceptions. The International Polar Years of 2007-2009-and associated "I*Y" science years such as IHY, IYPE and eGY-present a unique opportunity to change this. The people who can best effect this change are those who know the Poles best, through living or working there. Based on innovative but proven models, POLAR-PALOOZA will use three complementary strategies to engage, inform and inspire large public audiences. (1) A national tour, under the working title "Stories from a Changing Planet", will include in-person presentations at science centers, museums, libraries and schools across North America, including Canada and Mexico. The presentations will be augmented by High Definition Video taped on location at the Poles, audio and video podcasts, and special education and outreach activities for targeted audiences. "Stories from a Changing Planet" will provide diverse audiences with an exciting opportunity to meet and interact directly with polar experts, and to appreciate why the Poles and the research done there are directly relevant to their lives. (2) The "HiDef Video Science Story Capture Corps" is a team of professional videographers, using the latest generation of low-cost, high-quality cameras, deployed to both Poles. They will document the work of multiple researchers and projects, rather than focusing on one topic for a single broadcast program

  17. 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

  18. SEA SURFACE TEMPERATURE and Other Data from COLUMBUS and Other Platforms from 19250801 to 19320914 (NODC Accession 9400016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea Surface Temperatures (SST) data from 1925 to 1932 collected using ships COLUMBUS and EUROPA was submitted in two diskettes by Dr. Gerd Becker, Bundesamt fuer...

  19. 78 FR 58995 - Foreign-Trade Zone (FTZ) 138-Columbus, Ohio; Notification of Proposed Production Activity; Rolls...

    Science.gov (United States)

    2013-09-25

    ... Gas Turbines, Power Generation Turbines, and Generator Sets); Mount Vernon, Ohio The Columbus Regional... production of industrial gas turbines, power generation turbines, and generator sets. Pursuant to 15 CFR 400... status components used in export production. On its domestic sales, RRES would be able to choose the duty...

  20. The Struggle for Industrial Education in the "Lowell of the South," Columbus, Georgia, 1850-1930

    Science.gov (United States)

    Bradshaw, Lauren Yarnell; Bohan, Chara Haeussler

    2013-01-01

    The history of Columbus, Georgia, cannot be separated from that of the local textile mills; the mills were important in defining the economic success, the social struggles, and the enduring legacy of southern industrial tycoons. Evidence of this industrial past can be seen on almost every street, school, and business located in the city along the…

  1. Large Cluster of Neisseria meningitidis Urethritis in Columbus, Ohio, 2015.

    Science.gov (United States)

    Bazan, Jose A; Turner, Abigail Norris; Kirkcaldy, Robert D; Retchless, Adam C; Kretz, Cecilia B; Briere, Elizabeth; Tzeng, Yih-Ling; Stephens, David S; Maierhofer, Courtney; Del Rio, Carlos; Abrams, A Jeanine; Trees, David L; Ervin, Melissa; Licon, Denisse B; Fields, Karen S; Roberts, Mysheika Williams; Dennison, Amanda; Wang, Xin

    2017-07-01

    Neisseria meningitidis (Nm) is a Gram-negative diplococcus that normally colonizes the nasopharynx and rarely infects the urogenital tract. On Gram stain of urethral exudates, Nm can be misidentified as the more common sexually transmitted pathogen Neisseria gonorrhoeae. In response to a large increase in cases of Nm urethritis identified among men presenting for screening at a sexually transmitted disease clinic in Columbus, Ohio, we investigated the epidemiologic characteristics of men with Nm urethritis and the molecular and phylogenetic characteristics of their Nm isolates. The study was conducted between 1 January and 18 November 2015. Seventy-five Nm urethritis cases were confirmed by biochemical and polymerase chain reaction testing. Men with Nm urethritis were a median age of 31 years (interquartile range [IQR] = 24-38) and had a median of 2 sex partners in the last 3 months (IQR = 1-3). Nm cases were predominantly black (81%) and heterosexual (99%). Most had urethral discharge (91%), reported oral sex with a female in the last 12 months (96%), and were treated with a ceftriaxone-based regimen (95%). A minority (15%) also had urethral chlamydia coinfection. All urethral Nm isolates were nongroupable, ST-11 clonal complex (cc11), ET-15, and clustered together phylogenetically. Urethral Nm isolates were similar by fine typing (PorA P1.5-1,10-8, PorB 2-2, FetA F3-6), except 2, which had different PorB types (2-78 and 2-52). Between January and November 2015, 75 urethritis cases due to a distinct Nm clade occurred among primarily black, heterosexual men in Columbus, Ohio. Future urogenital Nm infection studies should focus on pathogenesis and modes of sexual transmission. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  2. 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.)

  3. ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS, COLUMBUS INDUSTRIES SL-3 RING PANEL

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of the High Efficiency Mini Pleat air filter for dust and bioaerosol filtration manufactured by Columbus Industries. The pressure drop across the filter was 142 Pa clean and 283 Pa dust load...

  4. The fifth international conference on Arabidopsis research

    Energy Technology Data Exchange (ETDEWEB)

    Hangarter, R.; Scholl, R.; Davis, K.; Feldmann, K.

    1993-12-31

    This volume contains abstracts of oral and poster presentations made in conjunction with the Fifth International Conference on Arabidopsis Research held August 19--22, 1993 at the Ohio State University, Columbus, Ohio.

  5. Christopher Columbus, Hernando Cortes, and Francisco Pizzaro: A Qualitative Content Analysis Examining Cultural Bias in World History Textbooks

    Science.gov (United States)

    Lillejord, Jebadiah Serril

    2013-01-01

    The purpose of this study is to investigate to what extent contemporary high school world history textbooks portray Christopher Columbus, Hernán Cortés, and Francisco Pizarro within the context of being "sacred," "profane," or someplace in between. To evaluate for existence of content bias this study employed qualitative…

  6. DOSIS & DOSIS 3D: long-term dose monitoring onboard the Columbus Laboratory of the International Space Station (ISS)

    Czech Academy of Sciences Publication Activity Database

    Berger, T.; Przybyla, B.; Matthia, D.; Reitz, G.; Burmeister, S.; Labrenz, J.; Bilski, P.; Horwacik, T.; Twardak, A.; Hajek, M.; Fugger, M.; Hofstatter, C.; Sihver, L.; Palfalvi, J. K.; Szabó, J.; Stradi, A.; Ambrožová, Iva; Kubančák, Ján; Brabcová, Kateřina; Vanhavere, F.; Cauwels, V.; Van Hoey, O.; Schoonjans, W.; Parisi, A.; Gaza, R.; Semones, E.; Yukihara, E.; Benton, E.; Doull, B. A.; Uchihori, Y.; Kodaira, S.; Kitamura, H.; Böhme, M.

    2016-01-01

    Roč. 6, NOV (2016), č. článku A39. ISSN 2115-7251 R&D Projects: GA ČR GJ15-16622Y Institutional support: RVO:61389005 Keywords : International Space Station * Columbus * space radiation * DOSIS * DOSIS 3D Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.446, year: 2016

  7. ISS COLUMBUS laboratory experiment `GeoFlow I and II' -fluid physics research in microgravity environment to study convection phenomena inside deep Earth and mantle

    Science.gov (United States)

    Futterer, Birgit; Egbers, Christoph; Chossat, Pascal; Hollerbach, Rainer; Breuer, Doris; Feudel, Fred; Mutabazi, Innocent; Tuckerman, Laurette

    Overall driving mechanism of flow in inner Earth is convection in its gravitational buoyancy field. A lot of effort has been involved in theoretical prediction and numerical simulation of both the geodynamo, which is maintained by convection, and mantle convection, which is the main cause for plate tectonics. Especially resolution of convective patterns and heat transfer mechanisms has been in focus to reach the real, highly turbulent conditions inside Earth. To study specific phenomena experimentally different approaches has been observed, against the background of magneto-hydrodynamic but also on the pure hydrodynamic physics of fluids. With the experiment `GeoFlow' (Geophysical Flow Simulation) instability and transition of convection in spherical shells under the influence of central-symmetry buoyancy force field are traced for a wide range of rotation regimes within the limits between non-rotating and rapid rotating spheres. The special set-up of high voltage potential between inner and outer sphere and use of a dielectric fluid as working fluid induce an electro-hydrodynamic force, which is comparable to gravitational buoyancy force inside Earth. To reduce overall gravity in a laboratory this technique requires microgravity conditions. The `GeoFlow I' experiment was accomplished on International Space Station's module COLUM-BUS inside Fluid Science Laboratory FSL und supported by EADS Astrium, Friedrichshafen, User Support und Operations Centre E-USOC in Madrid, Microgravity Advanced Research and Support Centre MARS in Naples, as well as COLUMBUS Control Center COL-CC Munich. Running from August 2008 until January 2009 it delivered 100.000 images from FSL's optical diagnostics module; here more precisely the Wollaston shearing interferometry was used. Here we present the experimental alignment with numerical prediction for the non-rotating and rapid rotation case. The non-rotating case is characterized by a co-existence of several stationary supercritical

  8. NSF Antarctic and Arctic Data Consortium; Scientific Research Support & Data Services for the Polar Community

    Science.gov (United States)

    Morin, P. J.; Pundsack, J. W.; Carbotte, S. M.; Tweedie, C. E.; Grunow, A.; Lazzara, M. A.; Carpenter, P.; Sjunneskog, C. M.; Yarmey, L.; Bauer, R.; Adrian, B. M.; Pettit, J.

    2014-12-01

    The U.S. National Science Foundation Antarctic & Arctic Data Consortium (a2dc) is a collaboration of research centers and support organizations that provide polar scientists with data and tools to complete their research objectives. From searching historical weather observations to submitting geologic samples, polar researchers utilize the a2dc to search andcontribute to the wealth of polar scientific and geospatial data.The goals of the Antarctic & Arctic Data Consortium are to increase visibility in the research community of the services provided by resource and support facilities. Closer integration of individual facilities into a "one stop shop" will make it easier for researchers to take advantage of services and products provided by consortium members. The a2dc provides a common web portal where investigators can go to access data and samples needed to build research projects, develop student projects, or to do virtual field reconnaissance without having to utilize expensive logistics to go into the field.Participation by the international community is crucial for the success of a2dc. There are 48 nations that are signatories of the Antarctic Treaty, and 8 sovereign nations in the Arctic. Many of these organizations have unique capabilities and data that would benefit US ­funded polar science and vice versa.We'll present an overview of the Antarctic & Arctic Data Consortium, current participating organizations, challenges & opportunities, and plans to better coordinate data through a geospatial strategy and infrastructure.

  9. 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...

  10. Arctic Research and Writing: A Lasting Legacy of the International Polar Year

    Science.gov (United States)

    Englert, Karl; Coon, Brian; Hinckley, Matt; Pruis, Matt

    2009-01-01

    Recently, senior-level physics students joined thousands of scientists from over 60 nations to examine a wide range of physical, biological, and social research topics as part of the International Polar Year (IPY). Through a National Science Foundation (NSF)-funded research project, these students applied physics concepts to the study of Arctic…

  11. PolarTREC—A Model Program for Taking Polar Literacy into the Future

    Science.gov (United States)

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

    2009-12-01

    Polar TREC—Teachers and Researchers Exploring and Collaborating, is a three-year (2007-2009) NSF-funded International Polar Year (IPY) teacher professional development program that advances Science, Technology, Engineering, and Mathematics (STEM) education by improving teacher content knowledge and instructional practices through Teacher Research Experiences (TRE) in the Arctic and Antarctic. Leveraging profound changes and fascinating science taking place in the polar regions, PolarTREC broadly disseminates activities and products to students, educators, researchers, and the public, connecting them with the Arctic and Antarctica and sustaining the widespread interest in the polar regions and building on the enthusiasm that was generated through IPY. Central to the PolarTREC Teacher Research Experience Model, over 40 teachers have spent two to eight weeks participating in hands-on research in the polar regions and sharing their experiences with diverse audiences via live events, online multimedia journals, and interactive bulletin boards. The Connecting Arctic/Antarctic Researchers and Educators (CARE) Network unifies learning community members participants, alumni, and others, developing a sustainable association of education professionals networking to share and apply polar STEM content and pedagogical skills. Educator and student feedback from preliminary results of the program evaluation has shown 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 in today’s world, as well as increased self-reported knowledge and interest in numerous science content areas. Building

  12. Charging Electric Vehicles in Smart Cities: An EVI-Pro Analysis of Columbus, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rames, Clement L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muratori, Matteo [National Renewable Energy Lab. (NREL), Golden, CO (United States); Srinivasa Raghavan, Sesha [National Renewable Energy Lab. (NREL), Golden, CO (United States); Young, Stanley E. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2018-02-09

    With the support of the U.S. Department of Energy's Vehicle Technologies Office, the National Renewable Energy Laboratory (NREL) worked with the City of Columbus, Ohio, to develop a plan for the expansion of the region's network of charging stations to support increased adoption of plug-in electric vehicles (PEVs) in the local market. NREL's Electric Vehicle Infrastructure Projection (EVI-Pro) model was used to generate scenarios of regional charging infrastructure to support consumer PEV adoption. Results indicate that approximately 400 Level 2 plugs at multi-unit dwellings and 350 Level 2 plugs at non-residential locations are required to support Columbus' primary PEV goal of 5,300 PEVs on the road by the end of 2019. This analysis finds that while consumer demand for fast charging is expected to remain low (due to modest anticipated adoption of short-range battery electric vehicles), a minimum level of fast charging coverage across the city is required to ease consumer range anxiety concerns by providing a safety net for unexpected charging events. Sensitivity analyses around some key assumptions have also been performed; of these, consumer preference for PHEV versus BEV and for their electric driving range, ambient conditions, and availability of residential charging at multi-unit dwellings were identified as key determinants of the non-residential PEV charging infrastructure required to support PEV adoption. The results discussed in this report can be leveraged by similar U.S. cities as part of a strategy to accelerate PEV adoption in the light-duty vehicle market.

  13. Polarized neutron scattering research: the beginning

    International Nuclear Information System (INIS)

    Mezei, F.

    2005-01-01

    The visionary idea of using neutron scattering for the study of magnetic phenomena in condensed matter was proposed by Bloch in 1936, mere 4 years after the neutron was discovered. It was based on one of the surprises the neutron presented the scientific community with: it is neutral, yet it has a magnetic moment, which latter was then not yet directly observed though. Although the first results proved to be mathematically wrong, due to a non-trivial ambiguity of classical electromagnetism theory, which could only be settled by neutron beam experiments 15 years later, the recognition lead to the advent of a most productive area of modern research, which culminated in the development of the powerful and sophisticated techniques of polarized neutron scattering. This recollection traces the early milestones of the development of the field in strong interaction between theory and experiment

  14. PolarTREC: Successful Methods and Tools for Attaining Broad Educational Impacts with Interdisciplinary Polar Science

    Science.gov (United States)

    Timm, K. M.; Warburton, J.; Owens, R.; Warnick, W. K.

    2008-12-01

    PolarTREC--Teachers and Researchers Exploring and Collaborating, a program of the Arctic Research Consortium of the U.S. (ARCUS), is a National Science Foundation (NSF)-funded International Polar Year (IPY) project in which K-12 educators participate in hands-on field experiences in the polar regions, working closely with IPY scientists as a pathway to improving science education. Developing long-term teacher- researcher collaborations through PolarTREC ensures up-to-date climate change science content will permeate the K-12 education system long after the IPY. By infusing education with the cutting edge science from the polar regions, PolarTREC has already shown an increase in student and public knowledge of and interest in the polar regions and global climate change. Preliminary evaluations have shown that PolarTREC's 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 regarding the importance of understanding the polar regions as a person in today's world. Researchers have been overwhelmingly satisfied with PolarTREC and cited several specific strengths, including the program's crucial link between the teachers' field research experiences and their classroom and the extensive training provided to teachers prior to their expedition. This presentation will focus on other successful components of the PolarTREC program and how researchers and organizations might use these tools to reach out to the public for long-term impacts. Best practices include strategies for working with educators and the development of an internet-based platform for teachers and researchers to interact with the public, combining several communication tools such as online journals and forums, real-time Internet seminars, lesson plans, activities, audio, and other educational resources that address a broad range of scientific

  15. Research and development on optically pumped polarized ion sources. Technical progress report, February 1, 1985-January 31, 1986

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1985-07-01

    During the past year we have studied the relaxation times in an optically pumped 23 Na vapor target, studied the effects of radiation trapping on the polarization in a Na vapor target, and have studied the effects of spin exchange collisions on a beam of fast H 0 atoms as they pass through a polarized alkali target. This research is directed toward improvements in the optically pumped Na or other alkali vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source as well as discussing the progress of our research on optically pumped Na or other alkali vapor targets. 81 refs., 9 figs

  16. Polarization plasma spectroscopy (PPS) viewed from plasma physics and fusion research

    International Nuclear Information System (INIS)

    Ida, Katsumi

    1998-01-01

    Recently the measurements of poloidal magnetic field become important in plasma physics and nuclear fusion research, since an improved confinement mode associating with a negative magnetic shear has been found. The polarization plasma spectroscopy is recognized to be a useful tool to measure poloidal magnetic field and pitch angle of magnetic field. (author)

  17. Initial research of np scattering with polarized deuterium target at ANKE/COSY

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Boxing [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Institute of Modern Physics, Chinese Academy of Sciences, 73000 Lanzhou (China); Collaboration: ANKE-Collaboration

    2014-07-01

    With the goal of understanding the nuclear forces, the ANKE collaboration has been working on a systematic NN spin program for many years. Due to the lack of free neutron sources experimental data of np scattering are very rare, especially at higher energies. It has been shown that using phase shift analysis (PSA) it is possible to reconstruct np scattering amplitudes from the spin observables of pd → {pp}{sub {sup 1}S{sub 0}}n charge-exchange reaction. So far experiments were conducted using polarized deuteron beams and hydrogen target, which led to valuable results. To extend the research up to the highest nucleon energy available at COSY (2.8 GeV), proton beam and polarized deuterium target will be used. This talk presents the results of the commissioning experiment of a deuterium target at ANKE with emphasis on the initial research of charge-exchange reaction.

  18. Oceanographic profile temperature, salinity, oxygen, and nutrients measurements collected using bottle from the Iselin Columbus in the Indian Ocean (Somalia Coast) (NODC Accession 0002225)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and nutrients data were collected using bottle casts from the COLUMBUS ISELIN in the Indian Ocean. Data were collected from 26 February 1979 to...

  19. AURORA BOREALIS: a polar-dedicated European Research Platform

    Science.gov (United States)

    Wolff-Boenisch, Bonnie; Egerton, Paul; Thiede, Joern; Roberto, Azzolini; Lembke-Jene, Lester

    2010-05-01

    Polar research and in particular the properties of northern and southern high latitude oceans are currently a subject of intense scientific debate and investigations, because they are subject to rapid and dramatic climatic variations. Polar regions react more rapidly and intensively to global change than other regions of the earth. A shrinking of the Arctic sea-ice cover, potentially leading to an opening of sea passages to the north of North America and Eurasia, on the long to a "blue" Arctic Ocean would additionally have a strong impact on transport, commerce and tourism bearing potential risk for humans and complex ecosystems in the future. In spite of their critical role processes and feedbacks, especially in winter but not exclusively, are virtually unknown: The Arctic Ocean for example, it is the only basin of the world's oceans that has essentially not been sampled by the drill ships of the Deep-Sea Drilling Project (DSDP) or the Ocean Drilling Program (ODP) and its long-term environmental history and tectonic structure is therefore poorly known. Exceptions are the ODP Leg 151 and the more recent very successful ACEX-expedition of the Integrated Ocean Drilling Program (IODP) in 2004. To help to address the most pressing questions regarding climate change and related processes, a Pan-European initiative in the field of Earth system science has been put in place: AURORA BOREALIS is the largest environmental research infrastructure on the ESFRI roadmap of the European Community. AURORA BOREALIS is a very powerful research icebreaker, which will enable year-round operations in the Arctic and the Antarctic as well as in the adjacent ocean basins. Equipped with its drilling rig, the vessel is also capable to explore the presently completely unknown Arctic deep-sea floor. Last but not least, the ship is a floating observatory and mobile monitoring platform that permits to measure on a long-term basis comprehensive time series in all research fields relevant to

  20. Spatio-temporal variability of the polar middle atmosphere. Insights from over 30 years of research satellite observations

    Energy Technology Data Exchange (ETDEWEB)

    Lahoz, W.A.; Orsolini, Y.J.; Manney, G.L.; Minschwaner, K.; Allen, D.R.; Errera, Q.; Jackson, D.R.; Lambert, A.; Lee, J.; Pumphrey, H.; Schwartz, M.; Wu, D.

    2012-07-01

    We discuss the insights that research satellite observations from the last 30 years have provided on the spatio-temporal variability of the polar middle atmosphere. Starting from the time of the NASA LIMS (Limb Infrared Monitor of the Stratosphere) and TOMS (Total Ozone Mapping Spectrometer) instruments, both launched in 1978, we show how these observations have augmented our knowledge of the polar middle atmosphere, in particular how information on ozone and tracers has augmented our knowledge of: (i) the spatial and temporal characteristics of the wintertime polar stratosphere and the summertime circulation; and (ii) the roles of chemistry and transport in determining the stratospheric ozone distribution. We address the increasing joint use of observations and models, in particular in data assimilation, in contributing to this understanding. Finally, we outline requirements to allow continuation of the wealth of information on the polar middle atmosphere provided by research satellites over the last 30 years.(Author)

  1. [Research on Spectral Polarization Imaging System Based on Static Modulation].

    Science.gov (United States)

    Zhao, Hai-bo; Li, Huan; Lin, Xu-ling; Wang, Zheng

    2015-04-01

    The main disadvantages of traditional spectral polarization imaging system are: complex structure, with moving parts, low throughput. A novel method of spectral polarization imaging system is discussed, which is based on static polarization intensity modulation combined with Savart polariscope interference imaging. The imaging system can obtain real-time information of spectral and four Stokes polarization messages. Compared with the conventional methods, the advantages of the imaging system are compactness, low mass and no moving parts, no electrical control, no slit and big throughput. The system structure and the basic theory are introduced. The experimental system is established in the laboratory. The experimental system consists of reimaging optics, polarization intensity module, interference imaging module, and CCD data collecting and processing module. The spectral range is visible and near-infrared (480-950 nm). The white board and the plane toy are imaged by using the experimental system. The ability of obtaining spectral polarization imaging information is verified. The calibration system of static polarization modulation is set up. The statistical error of polarization degree detection is less than 5%. The validity and feasibility of the basic principle is proved by the experimental result. The spectral polarization data captured by the system can be applied to object identification, object classification and remote sensing detection.

  2. Research and development on optically pumped polarized ion sources. Technical progress report, July 1, 1985-June 30, 1986

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1986-07-01

    The development of an optically pumped polarized 23 Na target is discussed. The three categories of research are: (1) electron spin relaxation of the 23 Na due to wall collisions; (2) effects of radiation trapping on the polarization that can be produced in an alkali target by optical pumping; and (3) the effects of spin exchange collisions in the polarization of a fast H 0 beam formed by charge transfer as an H + beam passes through a polarized alkali target. 90 refs., 7 figs

  3. Research status of large mode area single polarization active fiber

    Science.gov (United States)

    Xiao, Chun; Zhang, Ge; Yang, Bin-hua; Cheng, Wei-feng; Gu, Shao-yi

    2018-03-01

    As high power fiber laser used more and more widely, to increase the output power of fiber laser and beam quality improvement have become an important goal for the development of high power fiber lasers. The use of large mode fiber is the most direct and effective way to solve the nonlinear effect and fiber damage in the fiber laser power lifting process. In order to reduce the effect of polarization of the fiber laser system, the study found that when introduces a birefringence in the single-mode fiber, the polarization state changes caused by the birefringence is far greater than the random polarization state changes, then the external disturbance is completely submerged, finally the polarization can be controlled and stabilized. Through the fine design of the fiber structure, if the birefringence is high enough to achieve the separation of the two polarization states, the fiber will have a different cut-off mechanism to eliminate polarization which is not need, which will realize single mode single polarization transmission in a band. In this paper, different types of single polarization fiber design are presented and the application of these fibers are also discussed.

  4. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  5. 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

  6. Polar Biomedical Research - An Assessment.

    Science.gov (United States)

    1982-10-01

    on agriculture and imported food and fuel silviculture Attenuated solar spectrum Reduces ultraviolet radiation, leading to possible vitamin D...for an expanded population. Any experiments in polar regions in food production involving geothermal heat, solar energy, hydroponics, or aquaculture...to water problems are those of accumulation of solid waste. During winter, such waste, including garbage and disposable diapers , near dwellings is a

  7. Research on Full-polarization Bistatic Scattering Characteristics of Aircraft

    Directory of Open Access Journals (Sweden)

    Ai Xiaofeng

    2016-12-01

    Full Text Available Whole space polarimetric bistatic scattering data of full-size aircraft targets were calculated via the mature electromagnetic calculation software. The fluctuation statistics characteristic of the polarimetric bistatic Radar Cross-Section (RCS was carried out. It was found that the statistical properties of the four polarimetric types (HH, HV, VH, VV of polarimetric bistatic RCSs are nearly the same, while the monostatic main and cross polarization RCSs statistical properties were quite different from each other. The characteristics of the distribution statistic for the monostatic and bistatic polarization ratio were carried out. Moreover, it was found that the cross-main polarization ratios were quite different, while the main polarization ratios were similar. The statistical results provide a theoretical reference for fully polarimetric bistatic radar aircraft target detection experiments.

  8. Magnetic materials research with polarized neutrons

    International Nuclear Information System (INIS)

    Hammer, J.; Rauch, H.; Badurek, G.

    1980-01-01

    In order to study the mechanisms of time dependent effects in magnetic materials with superparamagnetic or spinglass behaviour as well as in ferromagnetic materials a 'dynamic neutron depolarization' system has been developed as a beam hole experiment at the TRIGA Mark II Reactor in Vienna. In the course of this experiment an increasing or decreasing polarization can be observed as a consequence of the interaction between spins of the polarized neutron beam and the magnetic structure if the magnetic clusters in the sample are stimulated by a short magnetic pulse, lasting up to a few seconds. In accordance with numerical calculations and theoretical considerations we can draw conclusions from dynamics in the range of 10 ms to 1 h within magnetic materials which give us additional information that cannot be obtained from experiments used so far

  9. Polarization and Persuasion: Integrating the Elaboration Likelihood Model with Explanations of Group Polarization.

    Science.gov (United States)

    Mongeau, Paul A.

    Interest has recently focused on group polarization as a function of attitude processes. Several recent reviewers have challenged polarization researchers to integrate the explanations of polarization to existing theories of attitude change. This review suggests that there exists a clear similarity between the social comparison and persuasive…

  10. 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.

  11. Polarization Optics in Telecommunications

    CERN Document Server

    Damask, Jay N

    2005-01-01

    The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

  12. Temperature data from buoy casts in the North Atlantic Ocean from the COLUMBUS and HMAS SWAN from 01 August 1928 to 04 September 1932 (NODC Accession 0000242)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature data were collected using buoy casts from the COLUMBUS and HMAS SWAN from August 1, 1928 to September 4, 1932 in the North Atlantic Ocean. Data were...

  13. Application of circular polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Miyahara, Tsuneaki; Kawata, Hiroshi

    1988-03-01

    The idea of using the polarizing property of light for physical experiment by controlling it variously has been known from old time, and the Faraday effect and the research by polarizing microscopy are its examples. The light emitted from the electron orbit of an accelerator has the different polarizing characteristics from those of the light of a laboratory light source, and as far as observing it within the electron orbit plane, it becomes linearly polarized light. By utilizing this property well, research is carried out at present in synchrotron experimental facilities. Recently, the technology related to the insert type light cources using permanent magnets has advanced remarkably, and circular polarized light has become to be producible. If the light like this can be obtained with the energy not only in far ultraviolet region but also to x-ray region at high luminance, new possibility should open. At the stage that the design of an insert type light source was finished, and its manufacture was started, the research on the method of evaluating the degree of circular polarization and the research on the utilization of circular polarized synchrotron radiation are earnestly carried out. In this report, the results of researches presented at the study meeting are summarized. Moreover, the design and manufacture of the beam lines for exclusive use will be carried out. (Kako, I.)

  14. DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009-2016

    Czech Academy of Sciences Publication Activity Database

    Berger, T.; Burmeister, S.; Matthiae, D.; Przybyla, B.; Reitz, G.; Bilski, P.; Hajek, M.; Sihver, L.; Szabó, J.; Ambrožová, Iva; Vanhavere, F.; Gaza, R.; Semones, E.; Yukihara, E. G.; Benton, E.; Uchihori, Y.; Kodaira, S.; Kitamura, H.; Böhme, M.

    2017-01-01

    Roč. 7, MAR (2017), č. článku A8. ISSN 2115-7251 R&D Projects: GA ČR GJ15-16622Y Institutional support: RVO:61389005 Keywords : International Space Station * Columbus * space radiation * DOSTEL * DOSIS 3D Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics, space science) Impact factor: 2.446, year: 2016

  15. The Current State of Nanoparticle-Induced Macrophage Polarization and Reprogramming Research

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Miao

    2017-02-01

    Full Text Available Macrophages are vital regulators of the host defense in organisms. In response to different local microenvironments, resting macrophages (M0 can be polarized into different phenotypes, pro-inflammatory (M1 or anti-inflammatory (M2, and perform different roles in different physiological or pathological conditions. Polarized macrophages can also be further reprogrammed by reversing their phenotype according to the changed milieu. Macrophage polarization and reprogramming play essential roles in maintaining the steady state of the immune system and are involved in the processes of many diseases. As foreign substances, nanoparticles (NPs mainly target macrophages after entering the body. NPs can perturb the polarization and reprogramming of macrophages, affect their immunological function and, therefore, affect the pathological process of disease. Optimally-designed NPs for the modulation of macrophage polarization and reprogramming might provide new solutions for treating diseases. Systematically investigating how NPs affect macrophage polarization is crucial for understanding the regulatory effects of NPs on immune cells in vivo. In this review, macrophage polarization by NPs is summarized and discussed.

  16. Barriers and facilitators to learning and performing cardiopulmonary resuscitation in neighborhoods with low bystander cardiopulmonary resuscitation prevalence and high rates of cardiac arrest in Columbus, OH.

    Science.gov (United States)

    Sasson, Comilla; Haukoos, Jason S; Bond, Cindy; Rabe, Marilyn; Colbert, Susan H; King, Renee; Sayre, Michael; Heisler, Michele

    2013-09-01

    Residents who live in neighborhoods that are primarily black, Latino, or poor are more likely to have an out-of-hospital cardiac arrest, less likely to receive cardiopulmonary resuscitation (CPR), and less likely to survive. No prior studies have been conducted to understand the contributing factors that may decrease the likelihood of residents learning and performing CPR in these neighborhoods. The goal of this study was to identify barriers and facilitators to learning and performing CPR in 3 low-income, high-risk, and predominantly black neighborhoods in Columbus, OH. Community-Based Participatory Research approaches were used to develop and conduct 6 focus groups in conjunction with community partners in 3 target high-risk neighborhoods in Columbus, OH, in January to February 2011. Snowball and purposeful sampling, done by community liaisons, was used to recruit participants. Three reviewers analyzed the data in an iterative process to identify recurrent and unifying themes. Three major barriers to learning CPR were identified and included financial, informational, and motivational factors. Four major barriers were identified for performing CPR and included fear of legal consequences, emotional issues, knowledge, and situational concerns. Participants suggested that family/self-preservation, emotional, and economic factors may serve as potential facilitators in increasing the provision of bystander CPR. The financial cost of CPR training, lack of information, and the fear of risking one's own life must be addressed when designing a community-based CPR educational program. Using data from the community can facilitate improved design and implementation of CPR programs.

  17. Barriers and Facilitators to Learning and Performing Cardiopulmonary Resuscitation (CPR) in Neighborhoods with Low Bystander CPR Prevalence and High Rates of Cardiac Arrest in Columbus, Ohio

    Science.gov (United States)

    Sasson, Comilla; Haukoos, Jason S.; Bond, Cindy; Rabe, Marilyn; Colbert, Susan H.; King, Renee; Sayre, Michael; Heisler, Michele

    2013-01-01

    Background Residents who live in neighborhoods that are primarily African-American, Latino, or poor are more likely to have an out-of-hospital cardiac arrest (OHCA), less likely to receive cardiopulmonary resuscitation (CPR), and less likely to survive. No prior studies have been conducted to understand the contributing factors that may decrease the likelihood of residents learning and performing CPR in these neighborhoods. The goal of this study was to identify barriers and facilitators to learning and performing CPR in three low-income, “high-risk” predominantly African American, neighborhoods in Columbus, Ohio. Methods and Results Community-Based Participatory Research (CBPR) approaches were used to develop and conduct six focus groups in conjunction with community partners in three target high-risk neighborhoods in Columbus, Ohio in January-February 2011. Snowball and purposeful sampling, done by community liaisons, was used to recruit participants. Three reviewers analyzed the data in an iterative process to identify recurrent and unifying themes. Three major barriers to learning CPR were identified and included financial, informational, and motivational factors. Four major barriers were identified for performing CPR and included fear of legal consequences, emotional issues, knowledge, and situational concerns. Participants suggested that family/self-preservation, emotional, and economic factors may serve as potential facilitators in increasing the provision of bystander CPR. Conclusion The financial cost of CPR training, lack of information, and the fear of risking one's own life must be addressed when designing a community-based CPR educational program. Using data from the community can facilitate improved design and implementation of CPR programs. PMID:24021699

  18. Establishing a definition of polar bear (Ursus maritimus) health: A guide to research and management activities

    Science.gov (United States)

    Patyk, Kelly A.; Duncan, Colleen G.; Nol, Pauline; Sonne, C.; Laidre, Kristin L.; Obbard, Martyn E.; Wiig, Øystein; Aars, Jon; Regehr, Eric V.; Gustafson, L.; Atwood, Todd C.

    2015-01-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress.

  19. Establishing a definition of polar bear (Ursus maritimus) health: a guide to research and management activities.

    Science.gov (United States)

    Patyk, Kelly A; Duncan, Colleen; Nol, Pauline; Sonne, Christian; Laidre, Kristin; Obbard, Martyn; Wiig, Øystein; Aars, Jon; Regehr, Eric; Gustafson, Lori L; Atwood, Todd

    2015-05-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress. Published by Elsevier B.V.

  20. Polarized light and optical measurement

    CERN Document Server

    Clarke, D N; Ter Haar, D

    2013-01-01

    Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

  1. Charge transport in non-polar and semi-polar III-V nitride heterostructures

    International Nuclear Information System (INIS)

    Konar, Aniruddha; Verma, Amit; Fang, Tian; Zhao, Pei; Jana, Raj; Jena, Debdeep

    2012-01-01

    Compared to the intense research focus on the optical properties, the transport properties in non-polar and semi-polar III-nitride semiconductors remain relatively unexplored to date. The purpose of this paper is to discuss charge-transport properties in non-polar and semi-polar orientations of GaN in a comparative fashion to what is known for transport in polar orientations. A comprehensive approach is adopted, starting from an investigation of the differences in the electronic bandstructure along different polar orientations of GaN. The polarization fields along various orientations are then discussed, followed by the low-field electron and hole mobilities. A number of scattering mechanisms that are specific to non-polar and semi-polar GaN heterostructures are identified, and their effects are evaluated. Many of these scattering mechanisms originate due to the coupling of polarization with disorder and defects in various incarnations depending on the crystal orientation. The effect of polarization orientation on carrier injection into quantum-well light-emitting diodes is discussed. This paper ends with a discussion of orientation-dependent high-field charge-transport properties including velocity saturation, instabilities and tunneling transport. Possible open problems and opportunities are also discussed. (paper)

  2. 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

  3. 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…

  4. Dynamically polarized hydrogen target as a broadband, wavelength-independent thermal neutron spin polarizer

    International Nuclear Information System (INIS)

    Zhao Jinkui; Garamus, Vasil M.; Mueller, Wilhelm; Willumeit, Regine

    2005-01-01

    A hydrogen-rich sample with dynamically polarized hydrogen nuclei was tested as a wavelength-independent neutron transmission spin polarizer. The experiment used a modified setup of the dynamic nuclear polarization target station at the GKSS research center. The standard solvent sample at the GKSS DNP station was used. It is 2.8mm thick and consists of 43.4wt% water, 54.6wt% glycerol, and 2wt% of EHBA-Cr(v) complex. The wavelength of the incident neutrons for the transmission experiment was λ=8.1A with Δλ/λ=10%. The polarization of neutron beam after the target sample was analyzed with a supermirror analyzer. A neutron polarization of -52% was achieved at the hydrogen polarization of -69%. Further experiments will test the feasibility of other hydrogen-rich materials, such as methane, as the polarizer. A theoretical calculation shows that a polarized methane target would allow over 95% neutron polarizations with more than 30% transmission

  5. Transforming Polar Research with Google Glass Augmented Reality (Invited)

    Science.gov (United States)

    Ruthkoski, T.

    2013-12-01

    Augmented reality is a new technology with the potential to accelerate the advancement of science, particularly in geophysical research. Augmented reality is defined as a live, direct or indirect, view of a physical, real-world environment whose elements are augmented (or supplemented) by computer-generated sensory input such as sound, video, graphics or GPS data. When paired with advanced computing techniques on cloud resources, augmented reality has the potential to improve data collection techniques, visualizations, as well as in-situ analysis for many areas of research. Google is currently a pioneer of augmented reality technology and has released beta versions of their wearable computing device, Google Glass, to a select number of developers and beta testers. This community of 'Glass Explorers' is the vehicle from which Google shapes the future of their augmented reality device. Example applications of Google Glass in geophysical research range from use as a data gathering interface in harsh climates to an on-site visualization and analysis tool. Early participation in the shaping of the Google Glass device is an opportunity for researchers to tailor this new technology to their specific needs. The purpose of this presentation is to provide geophysical researchers with a hands-on first look at Google Glass and its potential as a scientific tool. Attendees will be given an overview of the technical specifications as well as a live demonstration of the device. Potential applications to geophysical research in polar regions will be the primary focus. The presentation will conclude with an open call to participate, during which attendees may indicate interest in developing projects that integrate Google Glass into their research. Application Mockup: Penguin Counter Google Glass Augmented Reality Device

  6. 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.

  7. Study on polarized optical flow algorithm for imaging bionic polarization navigation micro sensor

    Science.gov (United States)

    Guan, Le; Liu, Sheng; Li, Shi-qi; Lin, Wei; Zhai, Li-yuan; Chu, Jin-kui

    2018-05-01

    At present, both the point source and the imaging polarization navigation devices only can output the angle information, which means that the velocity information of the carrier cannot be extracted from the polarization field pattern directly. Optical flow is an image-based method for calculating the velocity of pixel point movement in an image. However, for ordinary optical flow, the difference in pixel value as well as the calculation accuracy can be reduced in weak light. Polarization imaging technology has the ability to improve both the detection accuracy and the recognition probability of the target because it can acquire the extra polarization multi-dimensional information of target radiation or reflection. In this paper, combining the polarization imaging technique with the traditional optical flow algorithm, a polarization optical flow algorithm is proposed, and it is verified that the polarized optical flow algorithm has good adaptation in weak light and can improve the application range of polarization navigation sensors. This research lays the foundation for day and night all-weather polarization navigation applications in future.

  8. 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.

  9. 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

  10. New materials research for high spin polarized current

    International Nuclear Information System (INIS)

    Tezuka, Nobuki

    2012-01-01

    The author reports here a thorough investigation of structural and magnetic properties of Co 2 FeAl 0.5 Si 0.5 Heusler alloy films, and the tunnel magnetoresistance effect for junctions with Co 2 FeAl 0.5 Si 0.5 electrodes, spin injection into GaAs semiconductor from Co 2 FeAl 0.5 Si 0.5 , and spin filtering phenomena for junctions with CoFe 2 O 4 ferrite barrier. It was observed that tunnel magnetoresistance ratio up to 832%(386%) at 9 K (room temperature), which corresponds to the tunnel spin polarization of 0.90 (0.81) for the junctions using Co 2 FeAl 0.5 Si 0.5 Heusler electrodes by optimizing the fabrication condition. It was also found that the tunnel magnetoresistance ratio are almost the same between the junctions with Co 2 FeAl 0.5 Si 0.5 Heusler electrodes on Cr buffered (1 0 0) and (1 1 0) MgO substrates, which indicates that tunnel spin polarization of Co 2 FeAl 0.5 Si 0.5 for these two direction are almost the same. The next part of this paper is a spin filtering effect using a Co ferrite. The spin filtering effect was observed through a thin Co-ferrite barrier. The inverse type tunnel magnetoresistance ratio of −124% measured at 10 K was obtained. The inverse type magnetoresistance suggests the negative spin polarization of Co-ferrite barrier. The magnetoresistance ratio of −124% corresponds to the spin polarization of −0.77 by the Co-ferrite barrier. The last part is devoted to the spin injection from Co 2 FeAl 0.5 Si 0.5 into GaAs. The spin injection signal was clearly obtained by three terminal Hanle measurement. The spin relaxation time was estimated to be 380 ps measured at 5 K.

  11. 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

  12. NATO Advanced Research Workshop on The Morphology and Dynamics of the Polar Cusp

    CERN Document Server

    Egeland, Alv

    1985-01-01

    These proceedings are based upon introductory talks, research reports and discussions from the NATO Advanced Workshop on the "Morphology and Dynamics of the Polar Cusp", held at Lillehammer, Norway, 7-12 May, 1984. The upper atmosphere at high latitudes is called the "Earth's win­ dow to outer space". Through various electrodynamic coupling process­ es as well as through direct transfer of particles many geophysical effects displayed there are direct manifestations of phenomena occurring in the deep space. The high latitude ionosphere will also exert a feedback on the regions of the magnetosphere and atmosphere to which it is coupled, acting as a momentum and energy source and sink, and a source of particles. Of particular interest are the sections of the near space known as the Polar Cusp. A vast portion of the earth's magnetic field envelope is electrically connected to these regions. This geometry results in a spatial mapping of the magnetospheric pro­ cesses and a focusing on to the ionosphere. In the ...

  13. The research of urban spatial polarization based on the space of flows theory——a case study of Shanghai

    Directory of Open Access Journals (Sweden)

    LIU Chaoqing

    2013-04-01

    Full Text Available Based on the elite space and the relation model between the space of flows and the urban space,the paper analyzed the mechanism and consequence of the new urban spatial polarization.Using the Shanghai sixth census data and the sample data,the paper discussed the new phenomenon of urban spatial polarization in the information age by the location quotient analysis and GIS spatial analysis.The research result showed that the space of flows influencing urban spatial polarization through the elite space is a higher level agglomeration,including the spatial concentration of the human capital,the concentration of wealth and knowledge of science and technology.

  14. Elite Polarization and Public Opinion

    DEFF Research Database (Denmark)

    Robison, Joshua; Mullinix, Kevin

    2016-01-01

    Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how...... polarization is communicated to the public by news media. We report the results of one of the first content analyses to delve into the nature of news coverage of elite polarization. We show that such coverage is predominantly critical of polarization. Moreover, we show that unlike coverage of politics focused...... on individual politicians, coverage of elite polarization principally frames partisan divisions as rooted in the values of the parties rather than strategic concerns. We build on these novel findings with two survey experiments exploring the influence of these features of polarization news coverage on public...

  15. Polarized proton beams since the ZGS

    International Nuclear Information System (INIS)

    Krisch, A.D.

    1994-01-01

    The author discusses research involving polarized proton beams since the ZGS's demise. He begins by reminding the attendee that in 1973 the ZGS accelerated the world's first high energy polarized proton beam; all in attendance at this meeting can be proud of this accomplishment. A few ZGS polarized proton beam experiments were done in the early 1970's; then from about 1976 until 1 October 1979, the majority of the ZGS running time was polarized running. A great deal of fundamental physics was done with the polarized beam when the ZGS ran as a dedicated polarized proton beam from about Fall 1977 until it shut down on 1 October 1979. The newly created polarization enthusiats then dispersed; some spread polarized seeds al over the world by polarizing beams elsewhere; some wound up running the High Energy and SSC programs at DOE

  16. Design of reproducible polarized and non-polarized edge filters using genetic algorithm

    International Nuclear Information System (INIS)

    Ejigu, Efrem Kebede; Lacquet, B M

    2010-01-01

    Recent advancement in optical fibre communications technology is partly due to the advancement of optical thin film technology. The advancement of optical thin film technology includes the development of new and existing optical filter design methods. The genetic algorithm is one of the new design methods that show promising results in designing a number of complicated design specifications. It is the finding of this study that the genetic algorithm design method, through its optimization capability, can give more reliable and reproducible designs of any specifications. The design method in this study optimizes the thickness of each layer to get to the best possible solution. Its capability and unavoidable limitations in designing polarized and non-polarized edge filters from absorptive and dispersive materials is well demonstrated. It is also demonstrated that polarized and non-polarized designs from the genetic algorithm are reproducible with great success. This research has accomplished the great task of formulating a computer program using the genetic algorithm in a Matlab environment for the design of a reproducible polarized and non-polarized filters of any sort from any kind of materials

  17. Not a polar island: yellow fever, Spanish medical research, and the struggle for scientific and political hegemony in late nineteenth century Cuba

    Directory of Open Access Journals (Sweden)

    Francisco Javier Martínez

    Full Text Available Abstract: This paper explores questions related to yellow fever and the political destiny of Cuba in the late nineteenth century. A forgotten therapeutic device to treat the disease invented in that period, the “polar chamber” (cámara polar, provides a useful standpoint for reconstructing the tradition of Spanish yellow fever research in Cuba, a topic largely neglected by the medical historiography. The failed history of this device can also illuminate the complex struggle for scientific hegemony between Spanish, Cuban, and US institutions and researchers. Finally, we focus on the politics of the polar chamber by analyzing how this invention intended to provide a particular solution for the complex, threefold struggle for Cuba’s political future.

  18. PARTICULATE ORGANIC CARBON, cloud amount/frequency and other data from COLUMBUS ISELIN in the North American Coastline-South and South Atlantic Ocean from 1990-05-23 to 1990-06-13 (NODC Accession 9100150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data was collected from R/V COLUMBUS ISELIN in South Atlantic Ocean and North American Coast line-South during the Amazon Shelf Sediment Study (AMASSEDS) between May...

  19. Research on fusion algorithm of polarization image in tetrolet domain

    Science.gov (United States)

    Zhang, Dexiang; Yuan, BaoHong; Zhang, Jingjing

    2015-12-01

    Tetrolets are Haar-type wavelets whose supports are tetrominoes which are shapes made by connecting four equal-sized squares. A fusion method for polarization images based on tetrolet transform is proposed. Firstly, the magnitude of polarization image and angle of polarization image can be decomposed into low-frequency coefficients and high-frequency coefficients with multi-scales and multi-directions using tetrolet transform. For the low-frequency coefficients, the average fusion method is used. According to edge distribution differences in high frequency sub-band images, for the directional high-frequency coefficients are used to select the better coefficients by region spectrum entropy algorithm for fusion. At last the fused image can be obtained by utilizing inverse transform for fused tetrolet coefficients. Experimental results show that the proposed method can detect image features more effectively and the fused image has better subjective visual effect

  20. 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

  1. Polarized light in optics and spectroscopy

    CERN Document Server

    Kliger, David S

    1990-01-01

    This comprehensive introduction to polarized light provides students and researchers with the background and the specialized knowledge needed to fully utilize polarized light. It provides a basic introduction to the interaction of light with matter for those unfamiliar with photochemistry and photophysics. An in-depth discussion of polarizing optics is also given. Different analytical techniques are introduced and compared and introductions to the use of polarized light in various forms of spectroscopy are provided.Key Features* Starts at a basic level and develops tools for resear

  2. Notes from the Field: Increase in Neisseria meningitidis-Associated Urethritis Among Men at Two Sentinel Clinics - Columbus, Ohio, and Oakland County, Michigan, 2015.

    Science.gov (United States)

    Bazan, Jose A; Peterson, Amy S; Kirkcaldy, Robert D; Briere, Elizabeth C; Maierhofer, Courtney; Turner, Abigail Norris; Licon, Denisse B; Parker, Nicole; Dennison, Amanda; Ervin, Melissa; Johnson, Laura; Weberman, Barbara; Hackert, Pamela; Wang, Xin; Kretz, Cecilia B; Abrams, A Jeanine; Trees, David L; Del Rio, Carlos; Stephens, David S; Tzeng, Yih-Ling; DiOrio, Mary; Roberts, Mysheika Williams

    2016-06-03

    Neisseria meningitidis (Nm) urogenital infections, although less common than infections caused by Neisseria gonorrhoeae (Ng), have been associated with urethritis, cervicitis, proctitis, and pelvic inflammatory disease. Nm can appear similar to Ng on Gram stain analysis (gram-negative intracellular diplococci) (1-5). Because Nm colonizes the nasopharynx, men who receive oral sex (fellatio) can acquire urethral Nm infections (1,3,5). This report describes an increase in Nm-associated urethritis in men attending sexual health clinics in Columbus, Ohio, and Oakland County, Michigan.

  3. 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)

  4. 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....

  5. Effects of capturing and collaring on polar bears: findings from long-term research on the southern Beaufort Sea population

    Science.gov (United States)

    Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Atwood, Todd C.; Durner, George M.; Simac, Kristin S.; Amstrup, Steven C.

    2014-01-01

    Context: The potential for research methods to affect wildlife is an increasing concern among both scientists and the public. This topic has a particular urgency for polar bears because additional research is needed to monitor and understand population responses to rapid loss of sea ice habitat.Aims: This study used data collected from polar bears sampled in the Alaska portion of the southern Beaufort Sea to investigate the potential for capture to adversely affect behaviour and vital rates. We evaluated the extent to which capture, collaring and handling may influence activity and movement days to weeks post-capture, and body mass, body condition, reproduction and survival over 6 months or more.Methods: We compared post-capture activity and movement rates, and relationships between prior capture history and body mass, body condition and reproductive success. We also summarised data on capture-related mortality.Key results: Individual-based estimates of activity and movement rates reached near-normal levels within 2–3 days and fully normal levels within 5 days post-capture. Models of activity and movement rates among all bears had poor fit, but suggested potential for prolonged, lower-level rate reductions. Repeated captures was not related to negative effects on body condition, reproduction or cub growth or survival. Capture-related mortality was substantially reduced after 1986, when immobilisation drugs were changed, with only 3 mortalities in 2517 captures from 1987–2013.Conclusions: Polar bears in the southern Beaufort Sea exhibited the greatest reductions in activity and movement rates 3.5 days post-capture. These shorter-term, post-capture effects do not appear to have translated into any long-term effects on body condition, reproduction, or cub survival. Additionally, collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival.Implications: This study provides empirical evidence that current capture

  6. Proceedings of the meeting on the acceleration of polarized beams

    International Nuclear Information System (INIS)

    Takagi, Akira; Mori, Yoshiharu

    1980-08-01

    The project for accelerating polarized proton beam with the 12 GeV synchrotron in the National Laboratory for High Energy Physics was started in full scale, and the development of a polarized ion source of high intensity and the analysis of reduced polarization problem on the way to accelerate in the booster or the main ring have been carried out. On the other hand, with the cyclotrons in the Research Center for Nuclear Physics, Osaka University, and the Institute for Nuclear Research, University of Tokyo, and with the tandem machine in the Accelerator Center, Tsukuba University, polarized beams have already been accelerated, and the steady operations have been continued. Taking this opportunity, this study meeting was planned, considering that it is necessary to exchange informations among the researchers on polarized beam. It was the significant study meeting as unexpectedly many persons took part and the useful advices to the polarized beam project in this Laboratory were obtained. The construction of the preaccelerator for polarized protons was commenced in this year in the National Laboratory for High Energy Physics. In the proceedings, the introduction, the foreword, and eight papers are summarized. The progress of polarized beam researches in the world was mentioned in the introduction, and the project for proton acceleration in this Laboratory was explained in the foreword. (Kako, I.)

  7. Research progress of anti-icing/deicing technologies for polar ships and offshore platforms

    Directory of Open Access Journals (Sweden)

    XIE Qiang

    2017-01-01

    Full Text Available The polar regions present adverse circumstances of high humidity and strong air-sea exchange. As such, the surfaces of ships and platforms (oil exploiting and drilling platforms serving in polar regions can easily be frozen by ice accretion, which not only affects the operation of the equipment but also threatens safety. This paper summarizes the status of the anti-icing/deicing technologies of both China and abroad for polar ships and offshore platforms, and introduces the various effects of ice accretion on polar ships and offshore platforms, and the resulting safety impacts. It then reviews existing anti-icing/deicing technologies and methods of both China and abroad, including such active deicing methods as electric heating, infrared heating and ultrasonic guided wave deicing, as well as such passive deicing methods as super hydrophobic coating, sacrificial coating, aqueous lubricating layer coating and low cross-link density (with interfacial slippage coating, summarizes their applicability to polar ships and offshore platforms, and finally discusses their advantages/disadvantages.

  8. Metastability-exchange optical pumping of 3He for neutron polarizers

    International Nuclear Information System (INIS)

    Gentile, T.R.; Thompson, A.K.; Snow, W.M.

    1995-01-01

    Research is underway at NIST and IU to develop neutron polarizers that are based on polarized 3 He. Such polarizers rely on the strong spin dependence of the cross section for neutron capture by polarized 3 He. Two methods can produce the high density of polarized 3 He gas (10 19 -10 20 cm -3 ) required for an effective neutron polarizer: spin-exchange optical pumping, which is performed directly at high pressure (1-10 bar), and metastability-exchange optical pumping, in which the gas is polarized at low pressure (1 mbar) and then compressed. While we are pursuing both methods, progress in the metastable method will be discussed. The features of the metastable method are the high rate at which the gas can be polarized and the inherent separation of the optical pumping and target cells. In a landmark achievement, researchers at the Univ. of Mainz have developed a piston compressor that can fill a 130 cm 3 cell to a pressure of 7 bar of 45% polarized 3 He gas in 2 hours. We plan to develop a compressor and test it at the NIST Cold Neutron Research Facility. We have constructed a metastable-pumping apparatus at NIST and have obtained 76% polarization with a pumping rate of 1.2 x 10 18 atoms/sec in a 0.4 mbar, 270 cm 3 cell

  9. The development of the Asian Forum for Polar Sciences (AFoPS)

    Science.gov (United States)

    Kim, Yeadong; Jeong, Jihoon

    2015-12-01

    The Asian Forum for Polar Sciences (AFoPS), an international forum of Asian polar research institutes, was established for the advancement of polar sciences among its members in 2004. The Forum has served as an important medium of Asian collective endeavors for polar affairs in human and information exchange, research collaboration, and logistics cooperation for the last decade. The historical development of the AFoPS in retrospect can be divided into four phases: inception and establishment (2003-2004), growth and expansion (2005-2007), review and restructuring (2008-2011), and achievements and further measures (2012-2014). The progress of the AFoPS has not been linear and this trend will continue into the next decades. The Forum, however, clearly made achievements in this period of time, realizing multilateral research and logistics cooperation that would have been previously unimaginable; by doing so, it has laid the foundation for the future. Responsible for a great portion of the world's polar activities, the AFoPS will rise to meet the expectations of the world by producing notable research output, initiating international cooperative programs, and supporting non-polar Asian countries with education and research collaboration. These are the tasks of the AFoPS for the next decade and they require strategy that promotes and facilitates collaboration in a practical way and draws attention of non-polar Asian countries to the polar sciences.

  10. Techniques of production and analysis of polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

    The use of the unique polarization properties of synchrotron radiation in the hard x-ray spectral region (E>3 KeV) is becoming increasingly important to many synchrotron radiation researchers. The radiation emitted from bending magnets and conventional (planar) insertion devices (IDs) is highly linearly polarized in the plane of the particle's orbit. Elliptically polarized x-rays can also be obtained by going off axis on a bending magnet source, albeit with considerable loss of flux. The polarization properties of synchrotron radiation can be further tailored to the researcher's specific needs through the use of specialized insertion devices such as helical and crossed undulators and asymmetrical wigglers. Even with the possibility of producing a specific polarization, there is still the need to develop x-ray optical components which can manipulate the polarization for both analysis and further modification of the polarization state. A survey of techniques for producing and analyzing both linear and circular polarized x-rays will be presented with emphasis on those techniques which rely on single crystal optical components

  11. 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

  12. Atomic processes relevant to polarization plasma spectroscopy

    International Nuclear Information System (INIS)

    Fujimoto, T.; Koike, F.; Sakimoto, K.; Okasaka, R.; Kawasaki, K.; Takiyama, K.; Oda, T.; Kato, T.

    1992-04-01

    When atoms (ions) are excited anisotropically, polarized excited atoms are produced and the radiation emitted by these atoms is polarized. From the standpoint of plasma spectroscopy research, we review the existing data for various atomic processes that are related to the polarization phenomena. These processes are: electron impact excitation, excitation by atomic and ionic collisions, photoexcitation, radiative recombination and bremsstrahlung. Collisional and radiative relaxation processes of atomic polarization follow. Other topics included are: electric-field measurement, self alignment, Lyman doublet intensity ratio, and magnetic-field measurement of the solar prominence. (author)

  13. Development of a polarized neutron beam line at Algerian research reactors using McStas software

    Energy Technology Data Exchange (ETDEWEB)

    Makhloufi, M., E-mail: makhloufi_8m@yahoo.fr [Centre de Recherche Nucléaire de Birine (Algeria); Salah, H. [Centre de Recherche Nucléaire d' Alger (Algeria)

    2017-02-01

    Unpolarized instrumentation has long been studied and designed using McStas simulation tool. But, only recently new models were developed for McStas to simulate polarized neutron scattering instruments. In the present contribution, we used McStas software to design a polarized neutron beam line, taking advantage of the available spectrometers reflectometer and diffractometer in Algeria. Both thermal and cold neutron was considered. The polarization was made by two types of supermirrors polarizers FeSi and CoCu provided by the HZB institute. For sake of performance and comparison, the polarizers were characterized and their characteristics reproduced. The simulated instruments are reported. Flipper and electromagnets for guide field are developed. Further developments including analyzers and upgrading of the existing spectrometers are underway. - Highlights: • Permit to evaluate the feasibility of a polarized neutron scattering instrument prior to its implementation. • Help to understand the origin of instrumental imperfections and offer an optimized set up configuration. • Provide the possibility to use the FeSi and CoCu supermirrors, designed to polarize spin up cold neutron, to polarize thermal neutron.

  14. Development of a polarized neutron beam line at Algerian research reactors using McStas software

    International Nuclear Information System (INIS)

    Makhloufi, M.; Salah, H.

    2017-01-01

    Unpolarized instrumentation has long been studied and designed using McStas simulation tool. But, only recently new models were developed for McStas to simulate polarized neutron scattering instruments. In the present contribution, we used McStas software to design a polarized neutron beam line, taking advantage of the available spectrometers reflectometer and diffractometer in Algeria. Both thermal and cold neutron was considered. The polarization was made by two types of supermirrors polarizers FeSi and CoCu provided by the HZB institute. For sake of performance and comparison, the polarizers were characterized and their characteristics reproduced. The simulated instruments are reported. Flipper and electromagnets for guide field are developed. Further developments including analyzers and upgrading of the existing spectrometers are underway. - Highlights: • Permit to evaluate the feasibility of a polarized neutron scattering instrument prior to its implementation. • Help to understand the origin of instrumental imperfections and offer an optimized set up configuration. • Provide the possibility to use the FeSi and CoCu supermirrors, designed to polarize spin up cold neutron, to polarize thermal neutron.

  15. Optically pumped polarized 23Na vapor target for use in polarized ion source. Technical progress report

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1984-01-01

    We are currently measuring relaxation times in an optically pumped 23 Na vapor target. Our research is directed toward improvements in the optically pumped Na vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source and especially the optically pumped Na vapor target employed in this source as well as discussing the progress of our research on relaxation times in an optically pumped Na vapor target. 30 references, 6 figures, 3 tables

  16. 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.)

  17. CSU's MWV Observatory: A Facility for Research, Education and Outreach

    Science.gov (United States)

    Hood, John; Carpenter, N. D.; McCarty, C. B.; Samford, J. H.; Johnson, M.; Puckett, A. W.; Williams, R. N.; Cruzen, S. T.

    2014-01-01

    The Mead Westvaco Observatory (MWVO), located in Columbus State University's Coca-Cola Space Science Center, is dedicated to education and research in astronomy through hands-on engagement and public participation. The MWVO has recently received funding to upgrade from a 16-inch Meade LX-200 telescope to a PlaneWave CDK 24-inch Corrected Dall-Kirkham Astrograph telescope. This and other technological upgrades will allow this observatory to stream live webcasts for astronomical events, allowing a worldwide public audience to become a part of the growing astronomical community. This poster will explain the upgrades that are currently in progress as well as the results from the current calibrations. The goal of these upgrades is to provide facilities capable of both research-class projects and widespread use in education and public outreach. We will present our initial calibration and tests of the observatory equipment, as well as its use in webcasts of astronomical events, in solar observing through the use of specialized piggy-backed telescopes, and in research into such topics as asteroids, planetary and nebula imaging. We will describe a pilot research project on asteroid orbit refinement and light curves, to be carried out by Columbus State University students. We will also outline many of the K-12 educational and public outreach activities we have designed for these facilities. Support and funding for the acquisition and installation of the new PlaneWave CDK 24 has been provided by the International Museum and Library Services via the Museums for America Award.

  18. Calculation of particulate dispersion in a design-basis tornadic storm from the Battelle Memorial Institute, Columbus, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, D.W.

    1980-10-01

    A three-dimensional numerical model is used to calculate ground-level air concentration and deposition (due to precipitation scavenging) after a hypothetical tornado strike at the Battelle Memorial Institute at Columbus, Ohio. Plutonium particles less than 20 ..mu..m in diameter are assumed to be lifted into the tornadic storm cell by the vortex. The rotational characteristics of the tornadic storm are embedded within the larger mesoscale flow of the storm system. The design-basis translational wind value is based on probabilities associated with existing records of tornado strikes in the vicinity of the plant site. Turbulence exchange coefficients are based on empirical values deduced from experimental data in severe storms and from theoretical assumptions obtained from the literature. The method of moments is used to incorporate subgrid-scale resolution of the concentration within a grid cell volume.

  19. Calculation of particulate dispersion in a design-basis tornadic storm from the Battelle Memorial Institute, Columbus, Ohio

    International Nuclear Information System (INIS)

    Pepper, D.W.

    1980-10-01

    A three-dimensional numerical model is used to calculate ground-level air concentration and deposition (due to precipitation scavenging) after a hypothetical tornado strike at the Battelle Memorial Institute at Columbus, Ohio. Plutonium particles less than 20 μm in diameter are assumed to be lifted into the tornadic storm cell by the vortex. The rotational characteristics of the tornadic storm are embedded within the larger mesoscale flow of the storm system. The design-basis translational wind value is based on probabilities associated with existing records of tornado strikes in the vicinity of the plant site. Turbulence exchange coefficients are based on empirical values deduced from experimental data in severe storms and from theoretical assumptions obtained from the literature. The method of moments is used to incorporate subgrid-scale resolution of the concentration within a grid cell volume

  20. Physics with polarized beams. Report of the ANL Technical Advisory Panel. [Research with polarized proton beams

    Energy Technology Data Exchange (ETDEWEB)

    1975-11-01

    Experimental directions which will be the most useful in developing underlying theories of hadronic collisions are outlined. As a pedagogical device to accomplish this, approximate percentages of a total program which could be devoted to different areas have been quoted. Findings are presented in the form of a short basic report with several long detailed appendices. In the basic report our opinion as to the amount of polarized beam experimental effort that should be applied to the following areas is stated: nucleon-nucleon scattering, quasi-two-body processes, inclusive production, and new or unexplored areas (such as large p/sub T/ and invariance principles). Our reasoning is discussed briefly, however, the details are left for the appendices. Members of the panel present certain aspects of the above areas, which should be useful for planning and/or performing polarized beam experiments. The seven presentations are abstracted separately in ERA.

  1. Water physical and chemical data from current meter and bottle casts from the COLUMBUS ISELIN as part of the Ocean Continental Shelf - Mid Atlantic (OCS - Mid Atlantic) project, 1975-10-27 to 1975-11-06 (NODC Accession 7700454)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water physical and chemical data were collected using current meter and bottle casts from the COLUMBUS ISELIN from October 27, 1975 to November 6, 1975. Data were...

  2. New Applications of m-Polar Fuzzy Matroids

    Directory of Open Access Journals (Sweden)

    Musavarah Sarwar

    2017-12-01

    Full Text Available Mathematical modelling is an important aspect in apprehending discrete and continuous physical systems. Multipolar uncertainty in data and information incorporates a significant role in various abstract and applied mathematical modelling and decision analysis. Graphical and algebraic models can be studied more precisely when multiple linguistic properties are dealt with, emphasizing the need for a multi-index, multi-object, multi-agent, multi-attribute and multi-polar mathematical approach. An m-polar fuzzy set is introduced to overcome the limitations entailed in single-valued and two-valued uncertainty. Our aim in this research study is to apply the powerful methodology of m-polar fuzzy sets to generalize the theory of matroids. We introduce the notion of m-polar fuzzy matroids and investigate certain properties of various types of m-polar fuzzy matroids. Moreover, we apply the notion of the m-polar fuzzy matroid to graph theory and linear algebra. We present m-polar fuzzy circuits, closures of m-polar fuzzy matroids and put special emphasis on m-polar fuzzy rank functions. Finally, we also describe certain applications of m-polar fuzzy matroids in decision support systems, ordering of machines and network analysis.

  3. Comments to a polar bear population model

    OpenAIRE

    Øritsland, Nils Are

    1985-01-01

    Larsen, T. & Ugland, K. I. (Polar Research 2 n.s., 117-118) note correctly that a Leslie matrix model treats cubs and females as independent units which is not the case for polar bears. Population projections using the Leslie model with hunting mortalities added are instructive first approximations in evaluations of field data, however, and are recommended as exercises also for polar bear biologists. An APL programme for such projections is available.

  4. 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

  5. Scheme of adaptive polarization filtering based on Kalman model

    Institute of Scientific and Technical Information of China (English)

    Song Lizhong; Qi Haiming; Qiao Xiaolin; Meng Xiande

    2006-01-01

    A new kind of adaptive polarization filtering algorithm in order to suppress the angle cheating interference for the active guidance radar is presented. The polarization characteristic of the interference is dynamically tracked by using Kalman estimator under variable environments with time. The polarization filter parameters are designed according to the polarization characteristic of the interference, and the polarization filtering is finished in the target cell. The system scheme of adaptive polarization filter is studied and the tracking performance of polarization filter and improvement of angle measurement precision are simulated. The research results demonstrate this technology can effectively suppress the angle cheating interference in guidance radar and is feasible in engineering.

  6. Polarization profile of RF-sputtered self-polarized PZT thin films

    Czech Academy of Sciences Publication Activity Database

    Suchaneck, G.; Koehler, R.; Sandner, T.; Gerlach, G.; Deineka, Alexander; Jastrabík, Lubomír; Kosarev, A. I.; Andronov, A. N.

    2001-01-01

    Roč. 32, - (2001), s. 861-869 ISSN 1058-4587 R&D Projects: GA ČR GA202/00/1425 Institutional research plan: CEZ:A02/98:Z1-010-914 Keywords : self-polarization * electrode interaction * interface layer Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.512, year: 2001

  7. 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

  8. APECS: A Network for Polar Early Career Scientist Professional Development

    Science.gov (United States)

    Enderlin, E. M.

    2014-12-01

    The Association of Polar Early Career Researchers (APECS) is an international and interdisciplinary organization for undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and others with interests in the polar regions, alpine regions and the wider Cryosphere. APECS is a scientific, non-profit organization with free individual membership that aims to stimulate research collaborations and develop effective future leaders in polar research, education, and outreach. APECS grew out of the 4th International Polar Year (2007-08), which emphasized the need to stimulate and nurture the next generation of scientists in order to improve the understanding and communication of the polar regions and its global connections. The APECS organizational structure includes a Council and an elected Executive Committee that are supported by a Directorate. These positions are open to all individual members through a democratic process. The APECS Directorate is funded by the Norwegian Research Council, the University of Tromsø and the Norwegian Polar Institute and is hosted by the University of Tromsø. Early career scientists benefit from a range of activities hosted/organized by APECS. Every year, numerous activities are run with partner organizations and in conjunction with major polar conferences and meetings. In-person and online panels and workshops focus on a range of topics, from developing field skills to applying for a job after graduate school. Career development webinars are hosted each fall and topical research webinars are hosted throughout the year and archived online (http://www.apecs.is). The APECS website also contains abundant information on polar news, upcoming conferences and meetings, and job postings for early career scientists. To better respond to members' needs, APECS has national/regional committees that are linked to the international overarching organization. Many of these committees organize regional meetings or

  9. 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.)

  10. Time reversal tests in polarized neutron reactions

    International Nuclear Information System (INIS)

    Asahi, Koichiro; Bowman, J.D.; Crawford, B.

    1998-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). In recent years the nuclear weak interaction has been studied in the compound nucleus via parity violation. The observed parity-violating effects are strongly enhanced by nuclear structure. The predictions are that the interaction of polarized neutrons with polarized nuclear targets could be also used to perform sensitive tests of time-reversal-violation because of the nuclear enhancements. The author has designed experiments to search for time-reversal violation in neutron-nucleus interactions. He has also developed techniques to polarize neutrons with laser-polarized 3 He gas targets. Using the polarized 3 He neutron spin filter, he has performed two experiments at LANSCE: an absolute neutron beam polarization measurement with an accuracy of 0.2--0.3% and a neutron spin-rotation measurement on a 139 La sample

  11. Development of a polarized neutron beam line at Algerian research reactors using McStas software

    Science.gov (United States)

    Makhloufi, M.; Salah, H.

    2017-02-01

    Unpolarized instrumentation has long been studied and designed using McStas simulation tool. But, only recently new models were developed for McStas to simulate polarized neutron scattering instruments. In the present contribution, we used McStas software to design a polarized neutron beam line, taking advantage of the available spectrometers reflectometer and diffractometer in Algeria. Both thermal and cold neutron was considered. The polarization was made by two types of supermirrors polarizers FeSi and CoCu provided by the HZB institute. For sake of performance and comparison, the polarizers were characterized and their characteristics reproduced. The simulated instruments are reported. Flipper and electromagnets for guide field are developed. Further developments including analyzers and upgrading of the existing spectrometers are underway.

  12. Electron-Spin Filters Would Offer Spin Polarization Greater than 1

    Science.gov (United States)

    Ting, David Z.

    2009-01-01

    A proposal has been made to develop devices that would generate spin-polarized electron currents characterized by polarization ratios having magnitudes in excess of 1. Heretofore, such devices (denoted, variously, as spin injectors, spin polarizers, and spin filters) have typically offered polarization ratios having magnitudes in the approximate range of 0.01 to 0.1. The proposed devices could be useful as efficient sources of spin-polarized electron currents for research on spintronics and development of practical spintronic devices.

  13. SYMPOSIUM ON REMOTE SENSING IN THE POLAR REGIONS

    Science.gov (United States)

    The Arctic Institute of North America long has been interested in encouraging full and specific attention to applications of remote sensing to polar...research problems. The major purpose of the symposium was to acquaint scientists and technicians concerned with remote sensing with some of the...special problems of the polar areas and, in turn, to acquaint polar scientists with the potential of the use of remote sensing . The Symposium therefore was

  14. Archive of Geosample Data and Information from the Ohio State University Byrd Polar and Climate Research Center (BPCRC) Sediment Core Repository

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Byrd Polar and Climate Research Center (BPCRC) Sediment Core Repository operated by the Ohio State University is a partner in the Index to Marine and Lacustrine...

  15. 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

  16. Observations on Polar Coding with CRC-Aided List Decoding

    Science.gov (United States)

    2016-09-01

    TECHNICAL REPORT 3041 September 2016 Observations on Polar Coding with CRC-Aided List Decoding David Wasserman Approved for public release. SSC...described in [2, 3]. In FY15 and FY16 we used cyclic redundancy check (CRC)-aided polar list decoding [4]. Section 2 describes the basics of polar coding ...and gives details of the encoders and decoders we used. In the course of our research, we performed simulations of polar codes in hundreds of cases

  17. 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.

  18. 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.

  19. 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.)

  20. Operation of the optically pumped polarized H- source at LAMPF

    International Nuclear Information System (INIS)

    York, R.L.; Tupa, D.; Swenson, D.R.; van Dyck, O.B.

    1991-01-01

    We report on the first five months of operation of the Optically Pumped Polarized Ion Source (OPPIS) for the nuclear physics research program at LAMPF. The LAMPF OPPIS is unique in using Ti: Sapphire lasers to polarize the potassium charge-exchange medium, and until recently was unique in using a superconducting magnet in the ECR source and polarizer regions. The ECR extraction electrode biasing arrangement is also unique. Typical performance was 25 microamps of peak current (measured at 750 keV) with 55% beam polarization or 15 microamps at 62%. Ion source availability was greater than 90%. We also report our planned improvements in preparation for research operation in May of 1991. 3 refs., 4 figs

  1. 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

  2. 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

  3. 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)

  4. Polar Environment and Climate. The Challenges

    International Nuclear Information System (INIS)

    Cardinal, D.; Lipiatou, E.

    2007-01-01

    This publication summarises the presentations and discussions held during the title symposium. It includes session reports by chairs and short papers from attendees who were also invited to contribute. The report follows the structure of this multidisciplinary symposium: General session on the International Polar Year (IPY); Past, present and future climate; Human and wildlife health; Natural and socioeconomics impacts of climate change and finally, Public outreach, education and policy makers. The publication illustrates the importance and diversity of European research in the Polar Regions. It also identifies gaps in our current understanding of these particularly complex and vulnerable environments and the related research needs

  5. Characterization of Iron-Bearing Solids Used by Naturally-Occurring Microbes in the Anaerobic Degradation of Hydrocarbons

    National Research Council Canada - National Science Library

    Powell, David

    2000-01-01

    ... during a field experiment at Columbus Air Force Base, Columbus, Mississippi. While this research could find no statistically significant changes in the iron oxides in the aquifer material over time, this work did produce three important findings...

  6. Advancing Environmental Prediction Capabilities for the Polar Regions and Beyond during The Year of Polar Prediction

    Science.gov (United States)

    Werner, Kirstin; Goessling, Helge; Hoke, Winfried; Kirchhoff, Katharina; Jung, Thomas

    2017-04-01

    Environmental changes in polar regions open up new opportunities for economic and societal operations such as vessel traffic related to scientific, fishery and tourism activities, and in the case of the Arctic also enhanced resource development. The availability of current and accurate weather and environmental information and forecasts will therefore play an increasingly important role in aiding risk reduction and safety management around the poles. The Year of Polar Prediction (YOPP) has been established by the World Meteorological Organization's World Weather Research Programme as the key activity of the ten-year Polar Prediction Project (PPP; see more on www.polarprediction.net). YOPP is an internationally coordinated initiative to significantly advance our environmental prediction capabilities for the polar regions and beyond, supporting improved weather and climate services. Scheduled to take place from mid-2017 to mid-2019, the YOPP core phase covers an extended period of intensive observing, modelling, prediction, verification, user-engagement and education activities in the Arctic and Antarctic, on a wide range of time scales from hours to seasons. The Year of Polar Prediction will entail periods of enhanced observational and modelling campaigns in both polar regions. With the purpose to close the gaps in the conventional polar observing systems in regions where the observation network is sparse, routine observations will be enhanced during Special Observing Periods for an extended period of time (several weeks) during YOPP. This will allow carrying out subsequent forecasting system experiments aimed at optimizing observing systems in the polar regions and providing insight into the impact of better polar observations on forecast skills in lower latitudes. With various activities and the involvement of a wide range of stakeholders, YOPP will contribute to the knowledge base needed to managing the opportunities and risks that come with polar climate change.

  7. Response of currents and water quality to changes in dam operations in Hoover Reservoir, Columbus, Ohio, August 24–28, 2015

    Science.gov (United States)

    Vonins, Branden L.; Jackson, P. Ryan

    2017-05-25

    Hoover Reservoir, an important drinking water supply for the City of Columbus, Ohio, has been the source of a series of taste and odor problems in treated drinking water during the past few years. These taste and odor problems were caused by the compounds geosmin and 2-methylisoborneol, which are thought to have been related to cyanobacteria blooms. In an effort to reduce the phosphorus available for cyanobacteria blooms at fall turnover, the City of Columbus began experimenting with the dam’s selective withdrawal system to remove excess phosphorus in the hypolimnion, which is released from bottom sediments during summer anoxic conditions.The U.S. Geological Survey completed two synoptic survey campaigns to assess distributions of water quality and water velocity in the lower part of Hoover Reservoir to provide information on the changes to reservoir dynamics caused by changing dam operations. One campaign (campaign 1) was done while water was being withdrawn from the reservoir through the dam’s middle gate and the other (campaign 2) while water was being withdrawn through the dam’s lower gate. Velocities were measured using an acoustic Doppler current profiler, and water-quality parameters were measured using an autonomous underwater vehicle equipped with water-quality sensors. Along with the water-quality and water-velocity data, meteorological, inflow and outflow discharges, and independent water-quality data were compiled to monitor changes in other parameters that affect reservoir behavior. Monthly nutrient data, collected by the City of Columbus, were also analyzed for trends in concentration during periods of expected stratification.Based on the results of the two campaigns, when compared to withdrawing water through the middle gate, withdrawing water through the lower gate seemed to increase shear-driven mixing across the thermocline, which resulted in an increase in the depth of the epilimnion throughout the lower part of Hoover Reservoir. The

  8. Exploring Science Through Polar Exploration

    Science.gov (United States)

    Pfirman, S. L.; Bell, R. E.; Zadoff, L.; Kelsey, R.

    2003-12-01

    Exploring the Poles is a First Year Seminar course taught at Barnard College, Columbia University. First Year Seminars are required of incoming students and are designed to encourage critical analysis in a small class setting with focused discussion. The class links historical polar exploration with current research in order to: introduce non-scientists to the value of environmental science through polar literature; discuss issues related to venturing into the unknown that are of relevance to any discipline: self-reliance, leadership, preparation, decisions under uncertainty; show students the human face of science; change attitudes about science and scientists; use data to engage students in exploring/understanding the environment and help them learn to draw conclusions from data; integrate research and education. These goals are met by bringing analysis of early exploration efforts together with a modern understanding of the polar environment. To date to class has followed the efforts of Nansen in the Fram, Scott and Amundsen in their race to the pole, and Shackleton's Endurance. As students read turn-of-the-century expedition journals, expedition progress is progressively revealed on an interactive map showing the environmental context. To bring the exploration process to life, students are assigned to expedition teams for specific years and the fates of the student "expeditions" are based on their own decisions. For example, in the Arctic, they navigate coastal sea ice and become frozen into the ice north of Siberia, re-creating Nansen's polar drift. Fates of the teams varied tremendously: some safely emerged at Fram Strait in 4 years, while others nearly became hopelessly lost in the Beaufort Gyre. Students thus learn about variability in the current polar environment through first hand experience, enabling them to appreciate the experiences, decisions, and, in some cases, the luck, of polar explorers. Evaluation by the Columbia Center for New Media, Teaching

  9. 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

  10. Core Technology Development of Nuclear spin polarization

    International Nuclear Information System (INIS)

    Yoo, Byung Duk; Gwon, Sung Ok; Kwon, Duck Hee; Lee, Sung Man

    2009-12-01

    In order to study nuclear spin polarization, we need several core technologies such as laser beam source to polarize the nuclear spin, low pressured helium cell development whose surface is essential to maintain polarization otherwise most of the polarized helium relaxed in short time, development of uniform magnetic field system which is essential for reducing relaxation, efficient vacuum system, development of polarization measuring system, and development of pressure raising system about 1000 times. The purpose of this study is to develop resonable power of laser system, that is at least 5 watt, 1083 nm, 4GHz tuneable. But the limitation of this research fund enforce to develop amplifying system into 5 watt with 1 watt system utilizing laser-diod which is already we have in stock. We succeeded in getting excellent specification of fiber laser system with power of 5 watts, 2 GHz linewidth, more than 80 GHz tuneable

  11. 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.)

  12. 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.

  13. Advances in high power linearly polarized fiber laser and its application

    Science.gov (United States)

    Zhou, Pu; Huang, Long; Ma, Pengfei; Xu, Jiangming; Su, Rongtao; Wang, Xiaolin

    2017-10-01

    Fiber lasers are now attracting more and more research interest due to their advantages in efficiency, beam quality and flexible operation. Up to now, most of the high power fiber lasers have random distributed polarization state. Linearlypolarized (LP) fiber lasers, which could find wide application potential in coherent detection, coherent/spectral beam combining, nonlinear frequency conversion, have been a research focus in recent years. In this paper, we will present a general review on the achievements of various kinds of high power linear-polarized fiber laser and its application. The recent progress in our group, including power scaling by using power amplifier with different mechanism, high power linearly polarized fiber laser with diversified properties, and various applications of high power linear-polarized fiber laser, are summarized. We have achieved 100 Watt level random distributed feedback fiber laser, kilowatt level continuous-wave (CW) all-fiber polarization-maintained fiber amplifier, 600 watt level average power picosecond polarization-maintained fiber amplifier and 300 watt level average power femtosecond polarization-maintained fiber amplifier. In addition, high power linearly polarized fiber lasers have been successfully applied in 5 kilowatt level coherent beam combining, structured light field and ultrasonic generation.

  14. Polar Applications of Spaceborne Scatterometers

    Science.gov (United States)

    Long, David G.

    2017-01-01

    Wind scatterometers were originally developed for observation of near-surface winds over the ocean. They retrieve wind indirectly by measuring the normalized radar cross section (σo) of the surface, and estimating the wind via a geophysical model function relating σo to the vector wind. The σo measurements have proven to be remarkably capable in studies of the polar regions where they can map snow cover; detect the freeze/thaw state of forest, tundra, and ice; map and classify sea ice; and track icebergs. Further, a long time series of scatterometer σo observations is available to support climate studies. In addition to fundamental scientific research, scatterometer data are operationally used for sea-ice mapping to support navigation. Scatterometers are, thus, invaluable tools for monitoring the polar regions. In this paper, a brief review of some of the polar applications of spaceborne wind scatterometer data is provided. The paper considers both C-band and Ku-band scatterometers, and the relative merits of fan-beam and pencil-beam scatterometers in polar remote sensing are discussed. PMID:28919936

  15. Polarization Control for Silicon Photonic Circuits

    Science.gov (United States)

    Caspers, Jan Niklas

    In recent years, the field of silicon photonics has received much interest from researchers and companies across the world. The idea is to use photons to transmit information on a computer chip in order to increase computational speed while decreasing the power required for computation. To allow for communication between the chip and other components, such as the computer memory, these silicon photonics circuits need to be interfaced with optical fiber. Unfortunately, in order to interface an optical fiber with an integrated photonics circuit two major challenges need to be overcome: a mode-size mismatch as well as a polarization mismatch. While the problem of mode-size has been well investigated, the polarization mismatch has yet to be addressed. In order to solve the polarization mismatch one needs to gain control over the polarization of the light in a waveguide. In this thesis, I will present the components required to solve the polarization mismatch. Using a novel wave guiding structure, the hybrid plasmonic waveguide, an ultra-compact polarization rotator is designed, fabricated, and tested. The hybrid plasmonic rotator has a performance similar to purely dielectric rotators while being more than an order of magnitude smaller. Additionally, a broadband hybrid plasmonic coupler is designed and measured. This coupler has a performance similar to dielectric couplers while having a footprint an order of magnitude smaller. Finally, a system solution to the polarization mismatch is provided. The system, a polarization adapter, matches the incoming changing polarization from the fiber actively to the correct one of the silicon photonics circuit. The polarization adapter is demonstrated experimentally to prove its operation. This proof is based on dielectric components, but the aforementioned hybrid plasmonic waveguide components would make the system more compact.

  16. 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.

  17. 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.

  18. 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

  19. Present situation of researches on polar ionosphere by C.C.I.R

    International Nuclear Information System (INIS)

    Ishikawa, Saburo

    1974-01-01

    Various subjects of studies made by the sixth research committee of C.C.I.R. (International Radio Consultative Committee) are reported. The C.C.I.R. has not any definite study programme and question concerning polar ionosphere, because it studies and delivers opinion on the techniques and operation of radio communication especially in developing countries. The subjects of study programme by the sixth research committee are as follows: estimation of the intensity and transmission loss of space wave electric field in a zone between 1.5 and 40 MHz, observation of the ionosphere of oblique entrance, scattering propagation of ionosphere, back scattering, fading of signal transmitted through ionosphere, transmission of space waves in the zone between 150 and 1,500 kHz, and effect of ionosphere on space communication. In addition, the following fourteen reports are cited: confirmation of prodromal phenomena of ionosphere disturbances, observation of the ionosphere of oblique entrance, remote propagation with supermode, basic information on forecast, back scattering, side scattering from the ground surface and ionosphere, Esub(s) propagation, scattering propagation, Esub(s) forecast, fading, effect of ionosphere on the transmission between the earth and space, radio noise produced in and above ionosphere, and propagation of standard broadcast wave. (Iwakiri, K.)

  20. 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

  1. Effect of polar surfaces on organic molecular crystals

    Science.gov (United States)

    Sharia, Onise; Tsyshevskiy, Roman; Kuklja, Maija; University of Maryland College Park Team

    Polar oxide materials reveal intriguing opportunities in the field of electronics, superconductivity and nanotechnology. While behavior of polar surfaces has been widely studied on oxide materials and oxide-oxide interfaces, manifestations and properties of polar surfaces in molecular crystals are still poorly understood. Here we discover that the polar catastrophe phenomenon, known on oxides, also takes place in molecular materials as illustrated with an example of cyclotetramethylene tetranitramine (HMX) crystals. We show that the surface charge separation is a feasible compensation mechanism to counterbalance the macroscopic dipole moment and remove the electrostatic instability. We discuss the role of surface charge on degradation of polar surfaces, electrical conductivity, optical band-gap closure and surface metallization. Research is supported by the US ONR (Grants N00014-16-1-2069 and N00014-16-1-2346) and NSF. We used NERSC, XSEDE and MARCC computational resources.

  2. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON RHIC SPIN PHYSICS III AND IV, POLARIZED PARTONS AT HIGH Q2 REGION (VOLUME 31)

    International Nuclear Information System (INIS)

    BUNCE, G.; VIGDOR, S.

    2001-01-01

    International workshop on II Polarized Partons at High Q2 region 11 was held at the Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan on October 13-14, 2000, as a satellite of the international conference ''SPIN 2000'' (Osaka, Japan, October 16-21,2000). This workshop was supported by RIKEN (The Institute of Physical and Chemical Research) and by Yukawa Institute. The scientific program was focused on the upcoming polarized collider RHIC. The workshop was also an annual meeting of RHIC Spin Collaboration (RSC). The number of participants was 55, including 28 foreign visitors and 8 foreign-resident Japanese participants, reflecting the international nature of the RHIC spin program. At the workshop there were 25 oral presentations in four sessions, (1) RHIC Spin Commissioning, (2) Polarized Partons, Present and Future, (3) New Ideas on Polarization Phenomena, (4) Strategy for the Coming Spin Running. In (1) the successful polarized proton commissioning and the readiness of the accelerator for the physics program impressed us. In (2) and (3) active discussions were made on the new structure function to be firstly measured at RHIC, and several new theoretical ideas were presented. In session (4) we have established a plan for the beam time requirement toward the first collision of polarized protons. These proceedings include the transparencies presented at the workshop. The discussion on ''Strategy for the Coming Spin Running'' was summarized by the chairman of the session, S. Vigdor and G. Bunce

  3. 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

  4. 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

  5. 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)

  6. 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.

  7. Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

    OpenAIRE

    DWI RAMADHANI; SITI NURHAYATI; TUR RAHARDJO

    2014-01-01

    The presence of malarial pigment (haemozoin) due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional ...

  8. 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.

  9. Time-of-flight and vector polarization analysis for diffuse neutron scattering

    International Nuclear Information System (INIS)

    Schweika, W.

    2003-01-01

    The potential of pulsed neutron sources for diffuse scattering including time-of-flight (TOF) and polarization analysis is discussed in comparison to the capabilities of the present instrument diffuse neutron scattering at the research center Juelich. We present first results of a new method for full polarization analysis using precessing neutron polarization. A proposal is made for a new type of instrument at pulsed sources, which allows for vector polarization analysis in TOF instruments with multi-detectors

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Polarization-Insensitive Tunable Optical Filters based on Liquid Crystal Polarization Gratings

    Science.gov (United States)

    Nicolescu, Elena

    Tunable optical filters are widely used for a variety of applications including spectroscopy, optical communication networks, remote sensing, and biomedical imaging and diagnostics. All of these application areas can greatly benefit from improvements in the key characteristics of the tunable optical filters embedded in them. Some of these key parameters include peak transmittance, bandwidth, tuning range, and transition width. In recent years research efforts have also focused on miniaturizing tunable optical filters into physically small packages for compact portable spectroscopy and hyperspectral imaging applications such as real-time medical diagnostics and defense applications. However, it is important that miniaturization not have a detrimental effect on filter performance. The overarching theme of this dissertation is to explore novel configurations of Polarization Gratings (PGs) as simple, low-cost, polarization-insensitive alternatives to conventional optical filtering technologies for applications including hyperspectral imaging and telecommunications. We approach this goal from several directions with a combination of theory and experimental demonstration leading to, in our opinion, a significant contribution to the field. We present three classes of tunable optical filters, the first of which is an angle-filtering scheme where the stop-band wavelengths are redirected off axis and the passband is transmitted on-axis. This is achieved using a stacked configuration of polarization gratings of various thicknesses. To improve this class of filter, we also introduce a novel optical element, the Bilayer Polarization Grating, exhibiting unique optical properties and demonstrating complex anchoring conditions with high quality. The second class of optical filter is analogous to a Lyot filter, utilizing stacks of static or tunable waveplates sandwiched with polarizing elements. However, we introduce a new configuration using PGs and static waveplates to replace

  15. 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.

  16. 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.

  17. 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.

  18. DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009-2016

    Science.gov (United States)

    Berger, Thomas; Burmeister, Sönke; Matthiä, Daniel; Przybyla, Bartos; Reitz, Günther; Bilski, Pawel; Hajek, Michael; Sihver, Lembit; Szabo, Julianna; Ambrozova, Iva; Vanhavere, Filip; Gaza, Ramona; Semones, Edward; Yukihara, Eduardo G.; Benton, Eric R.; Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Boehme, Matthias

    2017-03-01

    The natural radiation environment in Low Earth Orbit (LEO) differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR), as well as of protons and electrons trapped in the Earth's radiation belts (Van Allen belts). Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs) might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments "Dose Distribution within the ISS (DOSIS)" (2009-2011) and "Dose Distribution within the ISS 3D (DOSIS 3D)" (2012-onwards) onboard the Columbus Laboratory of the International Space Station (ISS) use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL) and passive radiation detector packages (PDP) and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments' changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016 reached up to 286

  19. Temperature and salinity profiles from CTD casts from the SE Pacific (limit-140 W) from the COLUMBUS ISELIN and other platforms as part of the International Decade of Ocean Exploration / Coastal Upwelling Ecosystems Analysis (IDOE/CUEA) from 1977-03-17 to 1977-03-30 (NODC Accession 7900205)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profiles were collected from CTD casts in the SE Pacific (limit 140 W) from the COLUMBUS ISELIN and other platforms from 17 March 1977 to 30...

  20. The polarizing effect of arousal on negotiation.

    Science.gov (United States)

    Brown, Ashley D; Curhan, Jared R

    2013-10-01

    In this research, we examined the impact of physiological arousal on negotiation outcomes. Conventional wisdom and the prescriptive literature suggest that arousal should be minimized given its negative effect on negotiations, whereas prior research on misattribution of arousal suggests that arousal might polarize outcomes, either negatively or positively. In two experiments, we manipulated arousal and measured its effect on subjective and objective negotiation outcomes. Our results support the polarization effect. When participants had negative prior attitudes toward negotiation, arousal had a detrimental effect on outcomes, whereas when participants had positive prior attitudes toward negotiation, arousal had a beneficial effect on outcomes. These effects occurred because of the construal of arousal as negative or positive affect, respectively. Our findings have important implications not only for negotiation, but also for research on misattribution of arousal, which previously has focused on the target of evaluation, in contrast to the current research, which focused on the critical role of the perceiver.

  1. [Analysis of influencing factors of snow hyperspectral polarized reflections].

    Science.gov (United States)

    Sun, Zhong-Qiu; Zhao, Yun-Sheng; Yan, Guo-Qian; Ning, Yan-Ling; Zhong, Gui-Xin

    2010-02-01

    Due to the need of snow monitoring and the impact of the global change on the snow, on the basis of the traditional research on snow, starting from the perspective of multi-angle polarized reflectance, we analyzed the influencing factors of snow from the incidence zenith angles, the detection zenith angles, the detection azimuth angles, polarized angles, the density of snow, the degree of pollution, and the background of the undersurface. It was found that these factors affected the spectral reflectance values of the snow, and the effect of some factors on the polarization hyperspectral reflectance observation is more evident than in the vertical observation. Among these influencing factors, the pollution of snow leads to an obvious change in the snow reflectance spectrum curve, while other factors have little effect on the shape of the snow reflectance spectrum curve and mainly impact the reflection ratio of the snow. Snow reflectance polarization information has not only important theoretical significance, but also wide application prospect, and provides new ideas and methods for the quantitative research on snow using the remote sensing technology.

  2. 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

  3. 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

  4. 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...

  5. 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

  6. Non-sky polarization-based dehazing algorithm for non-specular objects using polarization difference and global scene feature.

    Science.gov (United States)

    Qu, Yufu; Zou, Zhaofan

    2017-10-16

    Photographic images taken in foggy or hazy weather (hazy images) exhibit poor visibility and detail because of scattering and attenuation of light caused by suspended particles, and therefore, image dehazing has attracted considerable research attention. The current polarization-based dehazing algorithms strongly rely on the presence of a "sky area", and thus, the selection of model parameters is susceptible to external interference of high-brightness objects and strong light sources. In addition, the noise of the restored image is large. In order to solve these problems, we propose a polarization-based dehazing algorithm that does not rely on the sky area ("non-sky"). First, a linear polarizer is used to collect three polarized images. The maximum- and minimum-intensity images are then obtained by calculation, assuming the polarization of light emanating from objects is negligible in most scenarios involving non-specular objects. Subsequently, the polarization difference of the two images is used to determine a sky area and calculate the infinite atmospheric light value. Next, using the global features of the image, and based on the assumption that the airlight and object radiance are irrelevant, the degree of polarization of the airlight (DPA) is calculated by solving for the optimal solution of the correlation coefficient equation between airlight and object radiance; the optimal solution is obtained by setting the right-hand side of the equation to zero. Then, the hazy image is subjected to dehazing. Subsequently, a filtering denoising algorithm, which combines the polarization difference information and block-matching and 3D (BM3D) filtering, is designed to filter the image smoothly. Our experimental results show that the proposed polarization-based dehazing algorithm does not depend on whether the image includes a sky area and does not require complex models. Moreover, the dehazing image except specular object scenarios is superior to those obtained by Tarel

  7. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  8. 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

  9. Polarized proton and deuteron solid HD targets

    International Nuclear Information System (INIS)

    Honig, A.

    1977-01-01

    A decade has now elapsed since HD was proposed as a polarized proton and deuteron target with exceptionally desirable properties. These include a very high free proton proportion, independently polarizable proton and deuteron systems, and a ''frozen-spin'' mode of operation which allows separation of the functions of production and utilization of the highly polarized target. A discussion is given of what can be expected of the polarized HD system right now, without further research. The basic features of solid HD pertinent to its use as a ''frozen-spin'' target are outlined, then a summary is given of the particular experimental results which support the contention that the target will perform successfully, and finally, some feasible operating modes and the expected performances from them are presented

  10. High-energy nuclear optics of polarized particles

    CERN Document Server

    Baryshevsky, Vladimir G

    2012-01-01

    The various phenomena caused by refraction and diffraction of polarized elementary particles in matter have opened up a new research area in the particle physics: nuclear optics of polarized particles. Effects similar to the well-known optical phenomena such as birefringence and Faraday effects, exist also in particle physics, though the particle wavelength is much less than the distance between atoms of matter. Current knowledge of the quasi-optical effects, which exist for all particles in any wavelength range (and energies from low to extremely high), will enable us to investigate different properties of interacting particles (nuclei) in a new aspect. This pioneering book will provide detailed accounts of quasi-optical phenomena in the particle polarization, and will interest physicists and professionals in experimental particle physics.

  11. Leaving School — learning at SEA: Regular high school education alongside polar research, not only during IPY

    Science.gov (United States)

    Gatti, S.

    2006-12-01

    their final exams — with outstanding results. External evaluation of HIGHSEA performed by the University Duisburg-Essen presents spectacular results of HIGHSEA students when compared with a control group. By exploring and establishing new ways of teaching and learning we are contributing to the ongoing discussion about the renewal of the German school system. Drawing on our rich experience in cooperation with local schools we are offering an international role-play game focusing around the sustainable use of Polar regions in times of global climate change. After regional, national and international runs of the game the activities will culminate during an international "World Youth Polar Conference" (WYPC) late in 2007. We offer the unique opportunity for researchers in the field of polar research to actively contribute to a major outreach activity during IPY and participate in our role-play as national ambassadors.

  12. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Barometric pressure sensor, Carbon dioxide (CO2) gas analyzer and other instruments from COLUMBUS WAIKATO in the Bass Strait, North Pacific Ocean and others from 2004-03-03 to 2006-01-15 (NODC Accession 0080979)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0080979 includes Surface underway, chemical, meteorological and physical data collected from COLUMBUS WAIKATO in the Bass Strait, North Pacific Ocean,...

  13. 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.

  14. Test of sup 3 He-based neutron polarizers at NIST

    CERN Document Server

    Jones, G L; Thompson, A K; Chowdhuri, Z; Dewey, M S; Snow, W M; Wietfeldt, F E

    2000-01-01

    Neutron spin filters based on polarized sup 3 He are useful over a wide neutron energy range and have a large angular acceptance among other advantages. Two optical pumping methods, spin-exchange and metastability-exchange, can produce the volume of highly polarized sup 3 He gas required for such neutron spin filters. We report a test of polarizers based on each of these two methods on a new cold, monochromatic neutron beam line at the NIST Center for Neutron Research.

  15. Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements.

    Science.gov (United States)

    Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di

    2014-11-03

    Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

  16. 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

  17. Sources of polarized neutrons

    International Nuclear Information System (INIS)

    Walter, L.

    1983-01-01

    Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

  18. 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.

  19. Polarization extinction ratio of the polarization crosstalk caused by point pressure force in the polarization-maintaining fiber

    Science.gov (United States)

    Mukhtubayev, Azamat B.; Aksarin, Stanislav M.; Strigalev, Vladimir E.

    2017-11-01

    A study of the orthogonal polarization modes crosstalk changes in the point of different mechanical actions (pressure force) in the polarization-maintaining fiber with straining elliptical cladding is presented. It was found that by increasing of the pressure force the polarization extinction ratio increases nonlinearly. Also revealed the dependence of the extinction coefficient and the angle between vector of the mechanical action and polarization axes of the test fiber, which leads to change the extinction coefficient variable from -57 dB to -25 dB under the pressure force of 0.7 N. Also it was found that the cross angle of the fiber axes doesn't influence on the extinction ratio value of the mechanical induced polarization crosstalk.

  20. Polarized secondary radioactive beams

    International Nuclear Information System (INIS)

    Zaika, N.I.

    1992-01-01

    Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

  1. DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009–2016

    Directory of Open Access Journals (Sweden)

    Berger Thomas

    2017-01-01

    Full Text Available The natural radiation environment in Low Earth Orbit (LEO differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR, as well as of protons and electrons trapped in the Earth’s radiation belts (Van Allen belts. Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments “Dose Distribution within the ISS (DOSIS” (2009–2011 and “Dose Distribution within the ISS 3D (DOSIS 3D” (2012–onwards onboard the Columbus Laboratory of the International Space Station (ISS use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL and passive radiation detector packages (PDP and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments’ changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016

  2. Scattering of polarized electrons from polarized targets: Coincidence reactions and prescriptions for polarized half-off-shell single-nucleon cross sections

    International Nuclear Information System (INIS)

    Caballero, J.A.; Massachusetts Inst. of Tech., Cambridge, MA; Donnelly, T.W.; Massachusetts Inst. of Tech., Cambridge, MA; Poulis, G.I.; Massachusetts Inst. of Tech., Cambridge, MA

    1993-01-01

    Coincidence reactions of the type vector A( vector e, e'N)B involving the scattering of polarized electrons from polarized targets are discussed within the context of the plane-wave impulse approximation. Prescriptions are developed for polarized half-off single-nucleon cross sections; the different prescriptions are compared for typical quasi-free kinematics. Illustrative results are presented for coincidence polarized electron scattering from typical polarized nuclei. (orig.)

  3. Scientific Participation at the Poles: K-12 Teachers in Polar Science for Careers and Classrooms

    Science.gov (United States)

    Crowley, S.; Warburton, 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. PolarTREC highlights the importance of involving teachers in scientific research in regards to their careers as educators and their ability to engage students in the direct experience of science. To date, PolarTREC has placed over 90 teachers with research teams in the Arctic and Antarctic. Published results of our program evaluation quantify the effect of the field experience on the teachers' use of the real scientific process in the classroom, the improvement in science content taught in classrooms, and the use of non-fiction texts (real data and science papers) as primary learning tools for students. Teachers and students both report an increase of STEM literacy in the classroom content, confidence in science education, as well as a markedly broadened outlook of science as essential to their future. Research conducted with science teams affirms that they are achieving broader impacts when PolarTREC teachers are involved in their expeditions. Additionally, they reported that these teachers making vital contributions to the success of the scientific project.

  4. Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

    Science.gov (United States)

    Van Delden, Jay S

    2003-07-15

    A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

  5. Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal

    Science.gov (United States)

    Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.

    2016-01-01

    The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

  6. Experiments with Fermilab polarized proton and polarized antiproton beams

    International Nuclear Information System (INIS)

    Yokosawa, A.

    1990-01-01

    We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the π degree production at high p perpendicular and in the Λ (Σ degree), π ± , π degree production at large x F , and Δσ L (pp, bar pp) measurements. 18 refs

  7. COSY Juelich - a cooler synchrotron for unpolarized and polarized medium-energy studies

    International Nuclear Information System (INIS)

    Seyfarth, H.

    2001-01-01

    Full text: The Forschungszentrum Juelich (Research Center Juelich) is one of the sixteen national research institutions in the 'Hermann von Helmholtz Association of German Research Centers'. It is dedicated to fundamental and applied research and development which can be summarized under five priorities: (i) structure of matter and materials research, (ii) information technology, (iii) life sciences, (iv) environment precaution research, and (v) energy technology. As one of the institutes within (i). the Institut fur Kernphysik (Institute for Nuclear Research) operates the COSY cooler synchrotron which allows to accelerate unpolarized and polarized protons and deuterons to the maximum momentum of 3450 MeV/c (2640 MeV and 2050 MeV kinetic energy for protons and deuterons, respectively). At low energy electron cooling can be used for beam preparation, whereas stochastic cooling can be applied to the accelerated beam. In the first years of operation since 1993 the experiments have been performed with the unpolarized proton beam. Since 1997 the polarized proton beam is available with increasing intensity and a typical degree of polarization of about 75 % up to the maximum beam energy. In 2000 the first unpolarized deuteron beam could be accelerated and stored at the maximum energy. Four target places exist for the internal experiments PISA. EDDA, COSY-II, and ANKE which use the circulating beam with thin solid strip or fiber targets and gas targets. The four experiments TOF, MOMO, GEM, NESSI, and JESSICA are using external beams. The programs of the experiments JESSICA (Juelich Experimental Spallation Setup in the COSY Area), NESSI (Neutron Scintillator and Silicon), and PISA (Proton Induced Spallation) aim at the measurement of data needed or the design of the target station of the planned European Spallation neutron Source (ESS). The set-up of PISA is replacing the earlier experiment COSY-13 which successfully completed its investigations on the production of

  8. 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.

  9. 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.

  10. Study of excess carrier dynamics in polar, semi-polar, and non-polar (In,Ga)N epilayers and QWs

    Energy Technology Data Exchange (ETDEWEB)

    Aleksiejunas, R. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Lubys, L.; Jarasiunas, K. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Vengris, M. [Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Wernicke, T.; Hoffmann, V.; Netzel, C.; Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Kneissl, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Institute of Solid State Physics, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

    2011-07-15

    We studied carrier recombination and diffusion in GaN/sapphire templates, (In,Ga)N layers, and (In,Ga)N quantum well structures oriented along the polar [0001], semi-polar [11-22], and non-polar [11-20] orientations by means of light induced transient grating, differential transmission, and photoluminescence optical techniques. We show that the lifetime of excess carriers drops by orders of magnitude when changing the orientation from polar to non-polar, both in GaN templates and (In,Ga)N layers. We attribute the shorter lifetime to carrier trapping by extended structural defects that are more abundant in non-polar grown samples. In addition, we observe pronounced carrier localization effects in the semi- and non-polar layers. We show that thick (In,Ga)N layers inherit the properties of the GaN templates. However, the thin quantum well structures show a lower carrier trapping activity. So, a better electrical quality can be assumed as compared to the thick (In,Ga)N layers. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Polarization and Piezoelectric Properties of a Nitrile Substituted Polyimide

    Science.gov (United States)

    Simpson, Joycelyn; Ounaies, Zoubeida; Fay, Catharine

    1997-01-01

    This research focuses on the synthesis and characterization of a piezoelectric (beta-CN)- APB/ODPA polyimide. The remanent polarization and piezoelectric d(sub 31) and g(sub 33) coefficients are reported to assess the effect of synthesis variations. Each of the materials exhibits a level of piezoelectricity which increases with temperature. The remanent polarization is retained at temperatures close to the glass transition temperature of the polyimide.

  12. Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

    Directory of Open Access Journals (Sweden)

    DWI RAMADHANI

    2014-03-01

    Full Text Available The presence of malarial pigment (haemozoin due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional light microscope and simple polarized light microscope were collected. All images were analyzed using ImageJ 1.47 software to measure the haemozoin areas. Our results showed that non birefringent haemozoin and birefringent haemozoin area was significantly different. This was because when using conventional light microscope the brown area that contained images of non birefringent haemozoin images also contained Kupffer cells which appeared as the same brown color as haemozoin. In contrast, haemozoin gave bright effect and can be easily differentiated with Kupffer cells in the birefringent haemozoin images. This study concluded that haemozoin detection in mouse liver histology using a simple polarized light microscope was more accurate compared to that of conventional light microscope.

  13. Polarized targets and beams

    International Nuclear Information System (INIS)

    Meyer, W.

    1985-01-01

    First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

  14. Recent progress on HYSPEC, and its polarization analysis capabilities

    Directory of Open Access Journals (Sweden)

    Winn Barry

    2015-01-01

    Full Text Available HYSPEC is a high-intensity, direct-geometry time-of-flight spectrometer at the Spallation Neutron Source, optimized for measurement of excitations in small single-crystal specimens with optional polarization analysis capabilities. The incident neutron beam is monochromated using a Fermi chopper with short, straight blades, and is then vertically focused by Bragg scattering onto the sample position by either a highly oriented pyrolitic graphite (unpolarized or a Heusler (polarized crystal array. Neutrons are detected by a bank of 3He tubes that can be positioned over a wide range of scattering angles about the sample axis. HYSPEC entered the user program in February 2013 for unpolarized experiments, and is already experiencing a vibrant research program. Polarization analysis will be accomplished by using the Heusler crystal array to polarize the incident beam, and either a 3He spin filter or a supermirror wide-angle polarization analyser to analyse the scattered beam. The 3He spin filter employs the spin-exchange optical pumping technique. A 60∘ wide angle 3He cell that matches the detector coverage will be used for polarization analysis. The polarized gas in the post-sample wide angle cell is designed to be periodically and automatically refreshed with an adjustable pressure of polarized gas, optically pumped in a separate cell and then transferred to the wide angle cell. The supermirror analyser has 960 supermirror polarizers distributed over 60∘, and has been characterized at the Swiss Spallation Neutron Source. The current status of the instrument and the development of its polarization analysis capabilities are presented.

  15. Isolated elliptically polarized attosecond soft X-ray with high-brilliance using polarization gating of harmonics from relativistic plasmas at oblique incidence.

    Science.gov (United States)

    Chen, Zi-Yu; Li, Xiao-Ya; Li, Bo-Yuan; Chen, Min; Liu, Feng

    2018-02-19

    The production of intense isolated attosecond pulse is a major goal in ultrafast research. Recent advances in high harmonic generation from relativistic plasma mirrors under oblique incidence interactions gave rise to photon-rich attosecond pulses with circular or elliptical polarization. However, to achieve an isolated elliptical attosecond pulse via polarization gating using currently available long driving pulses remains a challenge, because polarization gating of high harmonics from relativistic plasmas is assumed only possible at normal or near-normal incidence. Here we numerically demonstrate a scheme around this problem. We show that via control of plasma dynamics by managing laser polarization, it is possible to gate an intense single attosecond pulse with high ellipticity extending to the soft X-ray regime at oblique incidence. This approach thus paves the way towards a powerful tool enabling high-time-resolution probe of dynamics of chiral systems and magnetic materials with current laser technology.

  16. Reduction of coating induced polarization aberrations by controlling the polarization state variation

    International Nuclear Information System (INIS)

    Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

    2011-01-01

    The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

  17. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.; Bazilevsky, A.

    2011-08-18

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

    ).

  18. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    International Nuclear Information System (INIS)

    Fischer, W.; Bazilevsky, A.

    2011-01-01

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. (bar P)), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g. ).

  19. Apico-basal polarity complex and cancer

    Indian Academy of Sciences (India)

    2014-01-27

    Jan 27, 2014 ... tions (e.g. stem cell migration for renewal of skin and intes- tinal cell) .... past two decades of research on polarity complex has provided a wealth of ..... Strand D 2005 Reduced expression of Hugl-1 the human homo- logue of ...

  20. N-polar GaN epitaxy and high electron mobility transistors

    International Nuclear Information System (INIS)

    Wong, Man Hoi; Keller, Stacia; Dasgupta, Nidhi Sansaptak; Denninghoff, Daniel J; Kolluri, Seshadri; Brown, David F; Lu, Jing; Fichtenbaum, Nicholas A; Ahmadi, Elaheh; DenBaars, Steven P; Speck, James S; Mishra, Umesh K; Singisetti, Uttam; Chini, Alessandro; Rajan, Siddharth

    2013-01-01

    This paper reviews the progress of N-polar (0001-bar) GaN high frequency electronics that aims at addressing the device scaling challenges faced by GaN high electron mobility transistors (HEMTs) for radio-frequency and mixed-signal applications. Device quality (Al, In, Ga)N materials for N-polar heterostructures are developed using molecular beam epitaxy and metalorganic chemical vapor deposition. The principles of polarization engineering for designing N-polar HEMT structures will be outlined. The performance, scaling behavior and challenges of microwave power devices as well as highly-scaled depletion- and enhancement-mode devices employing advanced technologies including self-aligned processes, n+ (In,Ga)N ohmic contact regrowth and high aspect ratio T-gates will be discussed. Recent research results on integrating N-polar GaN with Si for prospective novel applications will also be summarized. (invited review)

  1. Nuclear polarization and neutrons

    International Nuclear Information System (INIS)

    Glaettli, H.

    1985-01-01

    Different possibilities for the use of polarized nuclei in thermal neutron scattering on condensed matter are reviewed. Highly polarized nuclei are the starting point for studying dipolar magnetic order. Systematic measurement of spin-dependent scattering lengths is possible on samples with polarized nuclei. Highly polarized hydrogen should help to unravel complicated structures in chemistry and biology. The use of polarized proton targets as an energy-independent neutron polarizer in the thermal and epithermal region should be considered afresh. (author)

  2. Biological Response to the Dynamic Spectral-Polarized Underwater Light Field

    Science.gov (United States)

    2013-09-30

    by studying a homogeneous turbid medium. The diffuse reflection is produced by incoherent multiple scattering and is solved through radiative...polarization manipulation experiments revealed that polarization reflectance in Atlantic needlefish is controlled at the periphery (Fig 28). 6 19...with camouflage researchers on isopod and kelp crab camouflage against algae and seagrasses at several different west coast universities (Dierssen

  3. NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

    NARCIS (Netherlands)

    SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

    1993-01-01

    Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

  4. 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)

  5. 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

  6. CMB polarization at large angular scales: Data analysis of the POLAR experiment

    International Nuclear Information System (INIS)

    O'Dell, Christopher W.; Keating, Brian G.; Oliveira-Costa, Angelica de; Tegmark, Max; Timbie, Peter T.

    2003-01-01

    The coming flood of cosmic microwave background (CMB) polarization experiments, spurred by the recent detection of CMB polarization by the DASI and WMAP instruments, will be confronted by many new analysis tasks specific to polarization. For the analysis of CMB polarization data sets, the devil is truly in the details. With this in mind, we present details of the data analysis for the POLAR experiment, which recently led to the tightest upper limits on the polarization of the cosmic microwave background radiation at large angular scales. We discuss the data selection process, map-making algorithms, offset removal, and likelihood analysis which were used to find upper limits on the polarization. Stated using the modern convention for reporting CMB Stokes parameters, these limits are 5.0 μK on both E- and B-type polarization at 95% confidence. Finally, we discuss simulations used to test our analysis techniques and to probe the fundamental limitations of the experiment

  7. Demography and population status of polar bears in western Hudson Bay

    Science.gov (United States)

    Lunn, Nicholas J.; Regher, Eric V; Servanty, Sabrina; Converse, Sarah J.; Richardson, Evan S.; Stirling, Ian

    2013-01-01

    We evaluated the demography and population status of the Western Hudson Bay (WH) polar bear subpopulation for the period 1984-2011, using live-recapture data from research studies and management actions, and dead-recovery data from polar bears harvested for subsistence purposes or removed during human-bear conflicts.

  8. The DOSIS -Experiment onboard the Columbus Laboratory of the International Space Station -Overview and first mission results

    Science.gov (United States)

    Reitz, Guenther; Berger, Thomas; Kürner, Christine; Burmeister, Sünke; Hajek, Michael; Bilski, Pawel; Horwacik, Tomasz; Vanhavere, Filip; Spurny, Frantisek; Jadrnickova, Iva; Pálfalvi, József K.; O'Sullivan, Denis; Yasuda, Nakahiro; Uchihori, Yukio; Kitamura, Hisashi; Kodaira, Satoshi; Yukihara, Eduardo; Benton, Eric; Zapp, Neal; Gaza, Ramona; Zhou, Dazhuang; Semones, Edward; Roed, Yvonne; Boehme, Matthias; Haumann, Lutz

    Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long dura-tion human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. The DOSIS (Dose Distribution inside the ISS) experiment, under the project and science lead of DLR, aims for the spatial and tempo-ral measurement of the radiation field parameters inside the European Columbus laboratory onboard the International Space Station. This goal is achieved by applying a combination of passive (Thermo-and Optical luminescence detectors and Nuclear track etch detectors) and active (silicon telescope) radiation detectors. The passive radiation detectors -so called pas-sive detector packages (PDP) are mounted at eleven positions within the Columbus laboratory -aiming for a spatial dose distribution measurement of the absorbed dose, the linear energy transfer spectra and the dose equivalent with an average exposure time of six months. Two active silicon telescopes -so called Dosimetry Telescopes (DOSTEL 1 and DOSTEL 2) together with a Data and Power Unit (DDPU) are mounted within the DOSIS Main Box at a fixed loca-tion beneath the European Physiology Module (EPM) rack. The DOSTEL 1 and DOSTEL 2 detectors are positioned at a 90 angle to each other for a precise measurement of the temporal and spatial variation of the radiation field, especially during crossing of the South Atlantic Anomaly (SAA). The DOSIS hardware was launched with the

  9. Few-body experiments with polarized beams and polarized targets

    International Nuclear Information System (INIS)

    Simmons, J.E.

    1983-01-01

    A survey is presented concerning recent polarization experiments in the elastic p-d, p- 3 He, and p- 4 He systems. Mention is made of selected neutron experiments. The nominal energy range is 10 to 1000 MeV. Recent results and interpretations of the p-d system near 10 MeV are discussed. New experiments on the energy dependence of back angle p-d tensor polarization are discussed with respect to resolution of discrepancies and difficulty of theoretical interpretation. Progress is noted concerning multiple scattering interpretation of forward p-d deuteron polarization. Some new results are presented concerning the p- 3 He system and higher energy p- 4 He polarization experiments. 52 references

  10. Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

    International Nuclear Information System (INIS)

    Makita, K.; Meng, C.

    1987-01-01

    On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

  11. Degree of polarization and source counts of faint radio sources from Stacking Polarized intensity

    International Nuclear Information System (INIS)

    Stil, J. M.; George, S. J.; Keller, B. W.; Taylor, A. R.

    2014-01-01

    We present stacking polarized intensity as a means to study the polarization of sources that are too faint to be detected individually in surveys of polarized radio sources. Stacking offers not only high sensitivity to the median signal of a class of radio sources, but also avoids a detection threshold in polarized intensity, and therefore an arbitrary exclusion of sources with a low percentage of polarization. Correction for polarization bias is done through a Monte Carlo analysis and tested on a simulated survey. We show that the nonlinear relation between the real polarized signal and the detected signal requires knowledge of the shape of the distribution of fractional polarization, which we constrain using the ratio of the upper quartile to the lower quartile of the distribution of stacked polarized intensities. Stacking polarized intensity for NRAO VLA Sky Survey (NVSS) sources down to the detection limit in Stokes I, we find a gradual increase in median fractional polarization that is consistent with a trend that was noticed before for bright NVSS sources, but is much more gradual than found by previous deep surveys of radio polarization. Consequently, the polarized radio source counts derived from our stacking experiment predict fewer polarized radio sources for future surveys with the Square Kilometre Array and its pathfinders.

  12. 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

  13. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

  14. Perceiving polarization with the naked eye: characterization of human polarization sensitivity

    Science.gov (United States)

    Temple, Shelby E.; McGregor, Juliette E.; Miles, Camilla; Graham, Laura; Miller, Josie; Buck, Jordan; Scott-Samuel, Nicholas E.; Roberts, Nicholas W.

    2015-01-01

    Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance. We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration. PMID:26136441

  15. Measurement of the polarized neutron---polarized 3He total cross section

    International Nuclear Information System (INIS)

    Keith, C.D.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S.

    1995-01-01

    The first measurements of polarized neutron--polarized 3 He scattering in the few MeV energy region are reported. The total cross section difference Δσ T for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of Δσ T using various descriptions of the 4 He continuum. A brute-force polarized target of solid 3 He has been developed for these measurements. The target is 4.3x10 22 atoms/cm 2 thick and is polarized to 38% at 7 Telsa and 12 mK. copyright 1995 American Institute of Physics

  16. Scattering with polarized neutrons

    International Nuclear Information System (INIS)

    Schweizer, J.

    2007-01-01

    In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

  17. 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

  18. Neutron scattering investigation on low-dimensional, quantum and frustrated magnetism and utilization of neutron polarization analysis. My first encounter with neutron research

    International Nuclear Information System (INIS)

    Kakurai, Kazuhisa

    2013-01-01

    My first encounter with neutron scattering research on low-dimensional magnetism at the Hahn-Meitner Institut under the supervision of Prof. H. Dachs and Prof. M. Steiner, were it all began, is accounted for. The polarized neutron analysis research on low-dimensional magnetism at the Institut Laue Langevin under the supervision of Dr. R. Pynn is also reported. I would like to dedicate this article to late Prof. H. Dachs expressing may deepest gratitude for his warm guidance during the early period of my neutron science carrier. (author)

  19. Possibility of determining gluon polarization via polarized top pairs in gamma-proton scattering

    International Nuclear Information System (INIS)

    Atag, S.; Billur, A.A.

    2009-01-01

    We study the possibility for directly measuring the polarized gluon distribution in the process γp→t-bar t. It is shown that polarization asymmetry of the final top quarks is proportional to the gluon polarization. With available energy and luminosity, the collision of a polarized proton beam and a Compton backscattered photon beam can create polarized top quarks which carry the spin information of the process. Energy dependence and angular distributions of the polarization asymmetry of the top pairs has been discussed including statistical uncertainty.

  20. 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

  1. Peculiarities of annihilation of polarized positronium in polarized media

    International Nuclear Information System (INIS)

    Silenko, A.Ya.

    2005-01-01

    Features of positronium annihilation (PA) in polarized media are investigated. Strong exchange interaction with nonpaired electrons of paramagnetic atoms essentially accelerates the PA in comparison with annihilation of free positrons. The value of the spin projection on the direction of polarized nonpaired electrons has essential effect on the orthopositronium lifetime and on the width of the gamma spectrum annihilation line. It is shown that these features of PA permit to use it for studying the paramagnetic polarization [ru

  2. 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

  3. Polarization effects. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.

    1981-01-01

    The use of polarized proton beams in ISABELLE is important for several general reasons: (1) With a single longitudinally polarized proton beam, effects involving parity violation can be identified and hence processes involving weak interactions can be separated from those involving strong and electromagnetic interactions. (2) Spin effects are important in the strong interactions and can be useful for testing QCD. The technique for obtaining polarized proton beams in ISABELLE appears promising, particularly in view of the present development of a polarized proton beam for the AGS. Projections for the luminosity in ISABELLE for collisions of polarized protons - one or both beams polarized with longitudinal or transverse polarization - range from 1/100 to 1 times the luminosity for unpolarized protons.

  4. Polarization Properties of Laser Solitons

    Directory of Open Access Journals (Sweden)

    Pedro Rodriguez

    2017-04-01

    Full Text Available The objective of this paper is to summarize the results obtained for the state of polarization in the emission of a vertical-cavity surface-emitting laser with frequency-selective feedback added. We start our research with the single soliton; this situation presents two perpendicular main orientations, connected by a hysteresis loop. In addition, we also find the formation of a ring-shaped intensity distribution, the vortex state, that shows two homogeneous states of polarization with very close values to those found in the soliton. For both cases above, the study shows the spatially resolved value of the orientation angle. It is important to also remark the appearance of a non-negligible amount of circular light that gives vectorial character to all the different emissions investigated.

  5. Instrumentation with polarized neutrons

    International Nuclear Information System (INIS)

    Boeni, P.; Muenzer, W.; Ostermann, A.

    2009-01-01

    Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

  6. Feasibility studies of a polarized positron source based on the Bremsstrahlung of polarized electrons

    International Nuclear Information System (INIS)

    Dumas, J.

    2011-09-01

    The nuclear and high-energy physics communities have shown a growing interest in the availability of high current, highly-polarized positron beams. A sufficiently energetic polarized photon or lepton incident on a target may generate, via Bremsstrahlung and pair creation within a solid target foil, electron-positron pairs that should carry some fraction of the initial polarization. Recent advances in high current (> 1 mA) spin polarized electron sources at Jefferson Lab offer the perspective of creating polarized positrons from a low energy electron beam. This thesis discusses polarization transfer from electrons to positrons in the perspective of the design optimization of a polarized positron source. The PEPPo experiment, aiming at a measurement of the positron polarization from a low energy (< 10 MeV) highly spin polarized electron beam is discussed. A successful demonstration of this technique would provide an alternative scheme for the production of low energy polarized positrons and useful information for the optimization of the design of polarized positron sources in the sub-GeV energy range. (author)

  7. [Communication and citizenship empowerment in health care: a case of action-research in a polarized Venezuela].

    Science.gov (United States)

    Nahón Serfaty, Isaac; Eid, Mahmoud

    2015-07-01

    An action-research project was implemented in Venezuela from 2009-2013 to empower social activists and patients in their fight against breast cancer (BC). The project was implemented in a context of high political and social polarization of the so-called «Bolivarian revolution». Based on an ecological perspective of health activism and communication, that encompasses the interpersonal, group and social levels, a series of activities were celebrated to develop the advocacy capabilities of citizens, especially women, expand the collaborative networks among different stakeholders, and promote a consensual view between social and institutional actors about a national response to fight BC. A horizontal and participatory communication allowed that the voice of usually marginalized actors was heard in the process of shaping health care policy.

  8. Dispersing surface-modified imogolite nanotubes in polar and non-polar solvents

    Science.gov (United States)

    Li, Ming; Brant, Jonathan A.

    2018-02-01

    Furthering the development of nanocomposite structures, namely membranes for water treatment applications, requires that methods be developed to ensure nanoparticle dispersion in polar and non-polar solvents, as both are widely used in associated synthesis techniques. Here, we report on a two-step method to graft polyvinylpyrrolidone (PVP), and a one-step method for octadecylphosphonic acid (OPA), onto the outer surfaces of imogolite nanotubes. The goal of these approaches was to improve and maintain nanotube dispersion in polymer compatible polar and non-polar solvents. The PVP coating modified the imogolite surface charge from positive to weakly negative at pH ≤ 9; the OPA made it weakly positive at acidic pH values to negative at pH ≥ 7. The PVP surface coating stabilized the nanotubes through steric hindrance in polar protic, dipolar aprotic, and chloroform. In difference to the PVP, the OPA surface coating allowed the nanotubes to be dispersed in n-hexane and chloroform, but not in the polar solvents. The lack of miscibility in the polar solvents, as well as the better dispersion in n-hexane, was attributed to the stronger hydrophobicity of the OPA polymer relative to the PVP. [Figure not available: see fulltext.

  9. Assessing Challenges and Opportunities for Education and Communication Activities for International Polar Year 2007-2008

    Science.gov (United States)

    McCaffrey, M. S.

    2005-05-01

    Considerable planning has gone into identifying ways to maximize International Polar Year 2007-2008 (IPY) as a global event that will facilitate the integration of research and education inherent in IPY, and draw the interest and involvement of people around the world. Documents developed through the IPY planning process, including NRC Reports (2004), and drafts reports on education and outreach from the ICSU IPY Planning Group in the Fall of 2004, and the Bridging the Poles workshop of June, 2004, articulate the tremendous potential for IPY beyond the formal research agenda and goals. With less that two years before the start of IPY and fewer than fours years before the activities are completed, these and emerging opportunities face a number of challenges. In addition to the limited time frame remaining to prepare for these activities, participants involved with IPY education and outreach will also need to consider factors such as: uncertain funding for such activities; the lack of established international networks for geoscience education; the need for high level coordination of IPY education and communication; and the creative and intellectual challenge of making the polar regions relevant to people around the world. The planning process has identified six constituencies as key audiences of IPY communication efforts: i) the scientific/research community, ii) young and potentially new polar researchers, iii) the pre-university education community, iv) arctic communities, iv) the general public, and v) decision-makers. Understanding and meeting these audiences' expectations through on-going evaluation and engagement will be key to successful IPY education and outreach efforts. A number of distinct education and outreach projects have been proposed to the ICSU-WMO IPY planning process, such as courses and workshops on specific aspects of IPY, including efforts to address the social and cultural dimension of Arctic peoples. To help meet the challenges, achieve the

  10. Modeling optical and UV polarization of AGNs. IV. Polarization timing

    Science.gov (United States)

    Rojas Lobos, P. A.; Goosmann, R. W.; Marin, F.; Savić, D.

    2018-03-01

    Context. Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods, such as spectroscopy and variability studies. Optical reverberation mapping allowed us to constrain the spatial dimension of the broad emission line region and thereby to measure the mass of supermassive black holes. Recently, reverberation was also applied to the polarized signal emerging from different AGN components. In principle, this should allow us to measure the spatial dimensions of the sub-parsec reprocessing media. Aim. We conduct numerical modeling of polarization reverberation and provide theoretical predictions for the polarization time lag induced by different AGN components. The model parameters are adjusted to the observational appearance of the Seyfert 1 galaxy NGC 4151. Methods: We modeled scattering-induced polarization and tested different geometries for the circumnuclear dust component. Our tests included the effects of clumpiness and different dust prescriptions. To further extend the model, we also explored the effects of additional ionized winds stretched along the polar direction, and of an equatorial scattering ring that is responsible for the polarization angle observed in pole-on AGN. The simulations were run using a time-dependent version of the STOKES code. Results: Our modeling confirms the previously found polarization characteristics as a function of the observer`s viewing angle. When the dust adopts a flared-disk geometry, the lags reveal a clear difference between type 1 and type 2 AGN. This distinction is less clear for a torus geometry where the time lag is more sensitive to the geometry and optical depth of the inner surface layers of the funnel. The presence of a scattering equatorial ring and ionized outflows increased the recorded polarization time lags, and the polar outflows smooths out dependence on viewing angle, especially for the higher optical depth of the

  11. On the theory of polar ozone holes

    International Nuclear Information System (INIS)

    Njau, E.C.

    1990-12-01

    The viable theories already proposed to explain polar ozone holes generally fall into two main categories, namely, chemical theories and dynamical theories. In both of these categories, polar stratospheric clouds (PSCs) are taken as part of the essential basis. Besides, all the dynamical theories are based upon temperature changes. Since formation of the PSCs is highly temperature-dependent, it has been concluded from recent research (e.g. see Kawahira and Hirooka) that temperature changes are a cause, not a result of ozone depletion in polar regions. On this basis, formulations are developed that represent short-term and long-term temperature variations in the polar regions due to natural processes. These variations, which are confined to a limited area around each pole, include specific oscillations with periods ranging from ∼ 2 years up to ∼ 218,597 years. Polar ozone variations are normally expected to be influenced by these temperature oscillations. It is, therefore, apparent that the generally decreasing trend observed in mean October ozone column at Halley Bay (76 deg. S, 27 deg. W) from 1956 up to 1987 is mostly caused by the decreasing phase of a combination of two natural temperature oscillations, one with a period of ∼ 70-80 years and the other with a period of ∼ 160-180 years. Contributions of other natural temperature oscillations are also mentioned and briefly discussed. (author). 35 refs, 4 figs

  12. Design and simulation of a novel circularly polarized antenna with polarization reconfigurable characteristics

    Directory of Open Access Journals (Sweden)

    Zhang Hai

    2016-01-01

    Full Text Available A novel circularly polarized antenna with polarization reconfigurable characteristics was designed using co-simulation of Ansoft HFSS and Designer software. It consists of a dual-polarized antenna and phase switching network which act as the feed network for the dual-polarized antenna. The phase switching network was designed based on a Wilkinson power divider, where the output port was connected with SPDT to form a switching network. By controlling the SPDT state-off / on, the phase difference of the two ports could be alternated, which generated the orthogonal modes between the two ports of dual-polarized antenna. So that Left-hand circular polarization (LHCP and Right-hand circular polarization (RHCP could be achieved. The simulation shown that reflection coefficient was less than -12 dB and the axial ratio was below 3 dB between 1.8 GHz and 2.4 GHz with polarization reconfigurable characteristics.

  13. Research on disk amplifiers as polarizer of electro-optical switch

    CERN Document Server

    Zheng Kui Xing; Feng Bin; Zheng Jian; Dong Yun; Peng Zhi Tao; Lu Jing Ping; Jing Feng; Wei Xiao Feng

    2002-01-01

    It benefits to decrease the engineering cost and to debase the technical crisis by the polarizer composed of amplifier Nd sup 3 sup + : glass slabs located with the Brewster angle in large scale multi-passes laser facility. The relationships of the isolation efficiency with the numbers of slab, the growth of the amplifier and the switch efficiency of Pockels cell are calculated theoretically. The experimental results indicated that the output energy ratio of this Pockels cell-amplifier isolation system is 1 : 8 while Pockels cell is on and off

  14. 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.

  15. VIIRS-J1 Polarization Narrative

    Science.gov (United States)

    Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.

    2015-01-01

    The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

  16. Polarized Emission from Gamma-Ray Burst Jets

    Directory of Open Access Journals (Sweden)

    Shiho Kobayashi

    2017-11-01

    Full Text Available I review how polarization signals have been discussed in the research field of Gamma-Ray Bursts (GRBs. I mainly discuss two subjects in which polarimetry enables us to study the nature of relativistic jets. (1 Jet breaks: Gamma-ray bursts are produced in ultra-relativistic jets. Due to the relativistic beaming effect, the emission can be modeled in a spherical model at early times. However, as the jet gradually slows down, we begin to see the edge of the jet together with polarized signals at some point. (2 Optical flash: later time afterglow is known to be insensitive to the properties of the original ejecta from the GRB central engine. However, a short-lived, reverse shock emission would enable us to study the nature of of GRB jets. I also briefly discuss the recent detection of optical circular polarization in GRB afterglow.

  17. Polarization of Be stars

    International Nuclear Information System (INIS)

    Johns, M.W.

    1975-01-01

    Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

  18. Ionic polarization

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1992-01-01

    Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

  19. Validation and Training at the Erasmus-USOC Using Payload Simulators

    Science.gov (United States)

    Cornelissen, F.; Wormgoor, P.

    2008-08-01

    With the launch of Columbus this year, Europeans will have for the first time their own scientific lab in orbit, making it possible to actually start the real exploitation of the scientific lab. Since Columbus is build with a European effort, the scientific return of the Columbus exploitation has been organized in a combined European collaboration as well. Many research stations located in nearly all corners of Europe will benefit from the capability to perform scientific experiments in microgravity aboard the pressurized research module. This is the direct result of the geographically dispersion of the responsibility for gaining scientific benefits. The monitoring and control of Columbus and its payloads in the different operations centers throughout Europe is bound technically in the so-called Columbus Decentralized Monitoring and Control System (CD- MCS). With a growing set of (scientific) capabilities onboard the International Space Station whilst having a stable crew-size onboard, the crew-time per payload is diminishing. However, being able to perform scientific monitoring from the ground segment will secure and optimize the scientific return. This requires proper training of operators on ground as well as the validation of scientific operations controlled from ground. After all, erroneous operations will negatively impact scientific return, even more with limited flight crew time. Both training and validation benefit greatly from the use of simulation. In this paper we will put forward that the use of modular simulators has been of great benefit in supporting the Erasmus-USOC in the exploitation of the European Drawer Rack (EDR) and the European Technology Exposure Facility (EuTEF) of the Columbus science lab.

  20. Space Radiation Measurement on the Polar Route onboard the Korean Commercial Flights

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2010-03-01

    Full Text Available This study was performed by the policy research project of Ministry of Land, Transport and Maritime Affairs, which title is “Developing safety standards and management of space radiation on the polar route”. In this research, total six experiments were performed using Korean commercial flights (B747. Three of those are on the polar route and the other three are on the north pacific route. Space radiation exposure measured on the polar route is the average 84.7 uSv. The simulation result using CARI-6M program gives 84.9 uSv, which is very similar to measured value. For the departure flight using the north pacific route, the measured space radiation is the average 74.4 uSv. It seems that is not so different to use the polar route or not for the return flight because the higher latitude effect causing the increase of space radiation is compensated by the shortened flight time effect causing decreasing space radiation exposure.

  1. POLARIZED BEAMS: 1 - Longitudinal electron spin polarization at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-09-15

    Wednesday 4 May marked a turning point in the art of the manipulation of spins in electron storage rings: longitudinal electron spin polarization (with the spins oriented along the electrons' direction of motion) was established in the electron ring of HERA, the electronproton collider at DESY in Hamburg. A polarization level of about 55% was obtained and polarizations of over 60% were reproducibly obtained in the following days. The beam energy was 27.52 GeV, corresponding to half integer spin tune of 62.5.

  2. Active polarization imaging system based on optical heterodyne balanced receiver

    Science.gov (United States)

    Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren

    2017-08-01

    Active polarization imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active polarization imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the horizontal and vertical polarization of reflected optical field simultaneously, which contain the polarization characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.

  3. Polarized Electrons at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, C.K.

    1997-12-31

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

  4. Polarization-induced sigma-holes and hydrogen bonding

    Czech Academy of Sciences Publication Activity Database

    Hennemann, M.; Murray, J. S.; Politzer, P.; Riley, Kevin Eugene; Clark, T.

    2012-01-01

    Roč. 18, č. 6 (2012), s. 2461-2469 ISSN 1610-2940 Institutional research plan: CEZ:AV0Z40550506 Keywords : hydrogen bond * sigma-hole * polarization * field effect * ab initio calculation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.984, year: 2012

  5. Adapting the HSV polarization-color mapping for regions with low irradiance and high polarization.

    Science.gov (United States)

    Scott Tyo, J; Ratliff, Bradley M; Alenin, Andrey S

    2016-10-15

    Many mappings from polarization into color have been developed so that polarization information can be displayed. One of the most common of these maps the angle of linear polarization into color hue and degree of linear polarization into color saturation, while preserving the irradiance information from the polarization data. While this strategy enjoys wide popularity, there is a large class of polarization images for which it is not ideal. It is common to have images where the strongest polarization signatures (in terms of degree of polarization) occur in regions of relatively low irradiance: either in shadow in reflective bands or in cold regions in emissive bands. Since the irradiance is low, the chromatic properties of the resulting images are generally not apparent. Here we present an alternate mapping that uses the statistics of the angle of polarization as a measure of confidence in the polarization signature, then amplifies the irradiance in regions of high confidence, and leaves it unchanged in regions of low confidence. Results are shown from an LWIR and a visible spectrum imager.

  6. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  7. Numerical modeling of polar mesocyclones generation mechanisms

    Science.gov (United States)

    Sergeev, Dennis; Stepanenko, Victor

    2013-04-01

    Polar mesocyclones, commonly referred to as polar lows, remain of great interest due to their complicated dynamics. These mesoscale vortices are small short-living objects that are formed over the observation-sparse high-latitude oceans, and therefore, their evolution can hardly be observed and predicted numerically. The origin of polar mesoscale cyclones is still a matter of uncertainty, though the recent numerical investigations [3] have exposed a strong dependence of the polar mesocyclone development upon the magnitude of baroclinicity. Nevertheless, most of the previous studies focused on the individual polar low (the so-called case studies), with too many factors affecting it simultaneously. None of the earlier studies suggested a clear picture of polar mesocyclone generation within an idealized experiment, where it is possible to look deeper into each single physical process. The present paper concentrates on the initial triggering mechanism of the polar mesocyclone. As it is reported by many researchers, some mesocyclones are formed by the surface forcing, namely the uneven distribution of heat fluxes. That feature is common on the ice boundaries [2], where intense air stream flows from the cold ice surface to the warm sea surface. Hence, the resulting conditions are shallow baroclinicity and strong surface heat fluxes, which provide an arising polar mesocyclone with potential energy source converting it to the kinetic energy of the vortex. It is shown in this paper that different surface characteristics, including thermal parameters and, for example, the shape of an ice edge, determine an initial phase of a polar low life cycle. Moreover, it is shown what initial atmospheric state is most preferable for the formation of a new polar mesocyclone or in maintaining and reinforcing the existing one. The study is based on idealized high-resolution (~2 km) numerical experiment in which baroclinicity, stratification, initial wind profile and disturbance, surface

  8. Polarization division multiple access with polarization modulation for LOS wireless communications

    Directory of Open Access Journals (Sweden)

    Cao Bin

    2011-01-01

    Full Text Available Abstract In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS of electromagnetic (EM waves for line-of-sight (LOS communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate, the discussed polarization division multiple access (PDMA and polarization modulation (PM are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.

  9. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  10. Polarized electrons at Jefferson laboratory

    International Nuclear Information System (INIS)

    Sinclair, C.K.

    1998-01-01

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented. copyright 1998 American Institute of Physics

  11. Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

    2016-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

  12. 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.

  13. Polarization: A Must for Fusion

    Directory of Open Access Journals (Sweden)

    Guidal M.

    2012-10-01

    Full Text Available Recent realistic simulations confirm that the polarization of the fuel would improve significantly the DT fusion efficiency. We have proposed an experiment to test the persistence of the polarization in a fusion process, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the neutrons and the change in the corresponding total cross section are related to the polarization persistence. The experimental polarization of DT fuel is a technological challenge. Possible paths for Magnetic Confinement Fusion (MCF and for Inertial Confinement Fusion (ICF are reviewed. For MCF, polarized gas can be used. For ICF, cryogenic targets are required. We consider both, the polarization of gas and the polarization of solid DT, emphasizing the Dynamic Nuclear polarization (DNP of HD and DT molecules.

  14. Simulation of generation and dynamics of polarization singularities with circular Airy beams.

    Science.gov (United States)

    Ye, Dong; Peng, Xinyu; Zhou, Muchun; Xin, Yu; Song, Minmin

    2017-11-01

    The generation and dynamics of polarization singularities have been underresearched for years, while the focusing property of the topological configuration has not been explored much. In this paper, we simulated the generation of low-order polarization singularities with a circular Airy beam and explored the focusing property of the synthetic light field during propagation due to the autofocusing of the component. Our work researched the focusing properties of the polarization singularity configuration, which may help to develop its application prospect.

  15. Some applications of polarized inelastic neutron scattering

    Indian Academy of Sciences (India)

    A brief account of applications of polarized inelastic neutron scattering in condensed matter research is given. ... the itinerant antiferromagnet chromium we demonstrate that the dynamics of the longitudinal and transverse excitations are very different, resolving a long standing puzzle concerning the slope of their dispersion.

  16. Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Wolber, J.; Ellner, F.; Fridlund, B.

    2004-01-01

    A method to generate strongly polarized nuclear spins in solution has been developed, using Dynamic Nuclear Polarization (DNP) at a temperature of 1.2K, and at a field of 3.354T, corresponding to an electron spin resonance frequency of 94GHz. Trityl radicals are used to directly polarize 13C...... and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

  17. The new polarized neutron reflectometer in Juelich

    International Nuclear Information System (INIS)

    Ruecker, U.; Alefeld, B.; Bergs, W.; Kentzinger, E.; Brueckel, T.

    1999-01-01

    On the basis of the HADAS spectrometer in the guide hall of the Juelich research reactor FRJ-2 a polarized neutron reflectometer is build with a 2D-position sensitive detector system. The new spectrometer is optimized for reflectivity and diffuse magnetic scattering measurements with small incident angles on thin magnetic films with thicknesses in the nm range. The polarization analyzer covers the whole detector area, so that a range of 2.5 deg in the scattering angle can be measured simultaneously. The analyzer consists of a stack of supermirrors tilted against the scattering plane. In this reflection geometry, the momentum transfer resolution of the instrument is not reduced, but the sample height is limited to 17 mm. For the monochromator, polarizer and collimation different setups have been compared on the basis of Monte-Carlo calculations: a focusing elliptical supermirror monochromator, a cylindrical mirror, a focusing pyrolytic graphite double monochromator and a double monochromator with bent perfect Si crystals. (author)

  18. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  19. Non-polar InGaN quantum dot emission with crystal-axis oriented linear polarization

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Benjamin P. L., E-mail: benjamin.reid@physics.ox.ac.uk; Chan, Christopher C. S.; Taylor, Robert A. [Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Kocher, Claudius [Department of Physics, University of Konstanz, Konstanz 78457 (Germany); Zhu, Tongtong; Oehler, Fabrice; Oliver, Rachel A. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2015-04-27

    Polarization sensitive photoluminescence is performed on single non-polar InGaN quantum dots. The studied InGaN quantum dots are found to have linearly polarized emission with a common polarization direction defined by the [0001] crystal axis. Around half of ∼40 studied dots have a polarization degree of 1. For those lines with a polarization degree less than 1, we can resolve fine structure splittings between −800 μeV and +800 μeV, with no clear correlation between fine structure splitting and emission energy.

  20. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  1. Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hamid Pahlevaninezhad

    2014-09-01

    Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

  2. 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

    The Suomi National Polar-orbiting Partnership (SNPP) satellite was successfully launched into a polar orbit on October 28, 2011 carrying 5 remote sensing instruments designed to provide data to improve weather forecasts and to increase understanding of long-term climate change. SNPP provides operational continuity of satellite-based observations for NOAA's Polar-orbiting Operational Environmental Satellites (POES) and continues the long-term record of climate quality observations established by NASA's Earth Observing System (EOS) satellites. In the 2003 to 2011 pre-launch timeframe, NASA's SNPP Science Team assessed the adequacy of the operational Raw Data Records (RDRs), Sensor Data Records (SDRs), and Environmental Data Records (EDRs) from the SNPP instruments for use in NASA Earth Science research, examined the operational algorithms used to produce those data records, and proposed a path forward for the production of climate quality products from SNPP. In order to perform these tasks, a distributed data system, the NASA Science Data Segment (SDS), ingested RDRs, SDRs, and EDRs from the NOAA Archive and Distribution and Interface Data Processing Segments, ADS and IDPS, respectively. The SDS also obtained operational algorithms for evaluation purposes from the NOAA Government Resource for Algorithm Verification, Independent Testing and Evaluation (GRAVITE). Within the NASA SDS, five Product Evaluation and Test Elements (PEATEs) received, ingested, and stored data and performed NASA's data processing, evaluation, and analysis activities. The distributed nature of this data distribution system was established by physically housing each PEATE within one of five Climate Analysis Research Systems (CARS) located at either at a NASA or a university institution. The CARS were organized around 5 key EDRs directly in support of the following NASA Earth Science focus areas: atmospheric sounding, ocean, land, ozone, and atmospheric composition products. The PEATES provided

  3. Production and delivery of polarized Xenon-129 for in vivo MRS/MRI.

    Science.gov (United States)

    Rosen, Matthew S.; Chupp, Timothy E.; Coulter, Kevin P.; Welsh, Robert C.; Swanson, Scott

    1998-05-01

    Laser polarized ^129Xe can be used as an entirely new magnetic tracer, and is a powerful enhancement to currently existing MRI techniques. Inert laser polarized ^129Xe is inhaled and transported via blood flow where it is detected using MR spectroscopy and imaging techniques. The time-dependent distribution patterns of ^129Xe signal intensity directly reflect local blood volume, blood flow rates, and the efficiency of perfusion and diffusive transport in tissues. We have developed a uniquely constructed laser polarized ^129Xe production and delivery system that is used in both our in vitro and in vivo imaging experiments with rats. This reliable, effective, and relatively simple production method for large volumes of laser polarized ^129Xe is the key to all other areas of research involving use of laser polarized gases.

  4. Techniques in polarization physics

    International Nuclear Information System (INIS)

    Clausnitzer, G.

    1974-01-01

    A review of the current status of the technical tools necessary to perform different kinds of polarization experiments is presented, and the absolute and relative accuracy with which data can be obtained is discussed. A description of polarized targets and sources of polarized fast neutrons is included. Applications of polarization techniques to other fields is mentioned briefly. (14 figures, 3 tables, 110 references) (U.S.)

  5. Polarization: A must for fusion

    Directory of Open Access Journals (Sweden)

    Didelez J.-P.

    2013-11-01

    Full Text Available The complete polarization of DT fuel would increase the fusion reactivity by 50% in magnetic as well as in inertial confinements. The persistence of polarization in a fusion process could be tested, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the emitted neutrons and the change in the corresponding total Cross Section (CS can sign the polarization persistence. The polarization of solid H2, D2 or T2 Hydrogen isotopes is very difficult. However, it has been possible to polarize HD, a hetero-molecular form of Hydrogen, by static polarization, at very low temperature and very high field. The radioactivity of DT molecules forbids there high polarization by the static method, therefore one has to develop the Dynamic Nuclear Polarization (DNP by RF transitions. The DNP of HD has been investigated in the past. The magnetic properties of HD and DT molecules are very similar, it is therefore expected that any polarization result obtained with HD could be extrapolated to DT.

  6. Status of the hydrogen and deuterium atomic beam polarized target for NEPTUN experiment

    International Nuclear Information System (INIS)

    Balandikov, N.I.; Ershov, V.P.; Fimushkin, V.V.; Kulikov, M.V.; Pilipenko, Y.K.; Shutov, V.B.

    1995-01-01

    NEPTUN-NEPTUN-A is a polarized experiment at Accelerating and Storage Complex (UNK, IHEP) with two internal targets. Status of the atomic beam polarized target that is being developed at the Joint Institute for Nuclear Research, Dubna is presented. copyright 1995 American Institute of Physics

  7. An elliptically-polarizing undulator with phase adjustable energy and polarization

    International Nuclear Information System (INIS)

    Lidia, S.

    1993-08-01

    The authors present a planar helical undulator designed to produce elliptically polarized light. Helical magnetic fields may be produced by a variety of undulators with four parallel cassettes of magnets. In their design, all cassettes are mounted in two planes on slides so that they may be moved parallel to the electron beam. This allows the undulator to produce x-rays of left- or right-handed elliptical or circular polarization as well as horizontal or vertical linear polarization. In model calculations, they have found that by sliding the top pair of rows with respect to the bottom pair, or the left pair with respect to the right pair, they retain the polarization setting but change the magnetic field strength, and hence the x-ray energy. This allows them to select both energy and polarization by independent phase adjustments alone, without changing the gap between the rows. Such a design may be simpler to construct than an adjustable gap machine. The authors present calculations that model its operation and its effects on an electron beam

  8. Linearly polarized photons at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, Holger [Physikalisches Institut, Universitaet Bonn (Germany)

    2009-07-01

    To investigate the nucleon resonance regime in meson photoproduction, double polarization experiments are currently performed at the electron accelerator ELSA in Bonn. The experiments make use of a polarized target and circularly or linearly polarized photon beams. Linearly polarized photons are produced by coherent bremsstrahlung from an accurately aligned diamond crystal. The orientation of the crystal with respect to the electron beam is measured using the Stonehenge-Technique. Both, the energy of maximum polarization and the plane of polarization, can be deliberately chosen for the experiment. The linearly polarized beam provides the basis for the measurement of azimuthal beam asymmetries, such as {sigma} (unpolarized target) and G (polarized target). These observables are extracted in various single and multiple meson photoproduction channels.

  9. Polarized atomic beams for targets

    International Nuclear Information System (INIS)

    Grueebler, W.

    1984-01-01

    The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

  10. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  11. 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.

  12. A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words.

    Science.gov (United States)

    Wang, Bingkun; Huang, Yongfeng; Wu, Xian; Li, Xing

    2015-01-01

    With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods.

  13. Poisson cluster analysis of cardiac arrest incidence in Columbus, Ohio.

    Science.gov (United States)

    Warden, Craig; Cudnik, Michael T; Sasson, Comilla; Schwartz, Greg; Semple, Hugh

    2012-01-01

    Scarce resources in disease prevention and emergency medical services (EMS) need to be focused on high-risk areas of out-of-hospital cardiac arrest (OHCA). Cluster analysis using geographic information systems (GISs) was used to find these high-risk areas and test potential predictive variables. This was a retrospective cohort analysis of EMS-treated adults with OHCAs occurring in Columbus, Ohio, from April 1, 2004, through March 31, 2009. The OHCAs were aggregated to census tracts and incidence rates were calculated based on their adult populations. Poisson cluster analysis determined significant clusters of high-risk census tracts. Both census tract-level and case-level characteristics were tested for association with high-risk areas by multivariate logistic regression. A total of 2,037 eligible OHCAs occurred within the city limits during the study period. The mean incidence rate was 0.85 OHCAs/1,000 population/year. There were five significant geographic clusters with 76 high-risk census tracts out of the total of 245 census tracts. In the case-level analysis, being in a high-risk cluster was associated with a slightly younger age (-3 years, adjusted odds ratio [OR] 0.99, 95% confidence interval [CI] 0.99-1.00), not being white, non-Hispanic (OR 0.54, 95% CI 0.45-0.64), cardiac arrest occurring at home (OR 1.53, 95% CI 1.23-1.71), and not receiving bystander cardiopulmonary resuscitation (CPR) (OR 0.77, 95% CI 0.62-0.96), but with higher survival to hospital discharge (OR 1.78, 95% CI 1.30-2.46). In the census tract-level analysis, high-risk census tracts were also associated with a slightly lower average age (-0.1 years, OR 1.14, 95% CI 1.06-1.22) and a lower proportion of white, non-Hispanic patients (-0.298, OR 0.04, 95% CI 0.01-0.19), but also a lower proportion of high-school graduates (-0.184, OR 0.00, 95% CI 0.00-0.00). This analysis identified high-risk census tracts and associated census tract-level and case-level characteristics that can be used to

  14. 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)

  15. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  16. Polarized neutron capture in polarized 59Co and 165Ho nuclei

    International Nuclear Information System (INIS)

    Bosman, J.J.

    1976-01-01

    Gamma spectroscopy on the reactions 59 Co(n,γ) 60 Co and 165 Ho(n,γ) 166 Ho with polarized neutrons and polarized targets enabled the assignment of spins to 36 levels in 60 Co and 15 levels in 166 Ho. Several of them had not been reported earlier. The techniques used to polarize neutron beams and targets and the gamma-spectroscopy are extensively discussed

  17. Review of polarized ammonium target

    International Nuclear Information System (INIS)

    Matsuda, Tatsuo

    1987-01-01

    Recently, ammonia (NH 3 ) and deutron ammonia (ND 3 ), instead of conventional alcohol substances, have been used more frequently as a polarized target substance for experiments of polarization at high energy regions. This article reviews major features of the polarized (deutron) ammonia targets. The dynamic nuclear polarization (DNT) method is widely used in high energy polarization experiments. While only a low polarization degree of hydrogen nucleus of 1.7 percent can be obtained by the Brute force method, DNP can produce polarization as high as ∼ 90 percent (2.5 T, ∼ 200 mK). In 1979, ammonia was irradiated with radiations to form NH 2 free radicals, resulting in the achievement of a high polarization degree of greater than 90 percent (hydrogen). Since then, ammonia and deutron ammonia have increasingly been replacing alcohols including butanol. Irradiation of a target substance with radiations destroys the structure of the substance, leading to a decrease in polarization degree. However, ammonia produces unpaired electrons as a result of irradiation, allowing it to be highly resistant to radiation. This report also present some study results, including observations on effects of radiation on the polarization degree of a target, effects of annealing, and polarization of 14 N. A process for producing an ammonia target is also described. (Nogami, K.)

  18. Measuring azimuthal asymmetries in semi-inclusive deep-inelastic scattering off transversely polarized protons

    CERN Document Server

    Wollny, Heiner

    2010-01-01

    The COMPASS experiment at the international research center CERN (European Organization for Nuclear Research) is dedicated to study the longitudinal and transverse spin structure of the nucleon. It is a fixed target experiment at the end of the M2 beam line of the SPS accelerator, which provides a 160 GeV/c longitudinally polarized muon beam. In the years 2002, 2003, 2004 and 2006 COMPASS took data scattering off polarized deuterons and in the year 2007 scattering off polarized protons. The analysis of the data taken in 2007 with transversely polarized protons is the topic of this thesis. In leading order and integrating over quark transverse momenta three parton distribution functions are needed for a complete description of the nucleon. Two of them, the quark number density and the helicity distribution are well known. However, the third one, the transversity distribution is up to now almost unknown. In this thesis single spin asymmetries in the cross-section of one hadron and two hadron production are anal...

  19. Achievement of transportable polarized D, in solid HD, with a one day passively maintained polarization

    International Nuclear Information System (INIS)

    Honig, A.; Alexander, N.; Fan, Q.; Wei, X.; Yu, Y.Y.

    1993-01-01

    At a previous workshop, we discussed evaporating solid HD with spin-polarized deuterons to produce a high density polarized deuteron gaseous internal target. Since then, we have achieved in solid HD 38% polarized D, whose spin-lattice relaxation time at 1.5 K in a field of 0.1 T is of the order of a day. Optimization of the procedure with the present apparatus should result in 60% D polarization, and longer polarization holding times. The polarized sample of approximately 0.2 cm 3 volume used here is extractable from the dilution refrigerator with a cold-transfer apparatus which maintains the sample at or below 5 K, insuring retention of the high polarization. It is subsequently insertable into a variety of systems, and employable as a polarized solid, liquid, or gas. We are exploring the possibility of extending the polarization maintenance time to about a month (with a matched 1 month preparation time), of polarizing metastably H as well as D, and of producing much larger samples, of the order of 100 cm 3

  20. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    Buon, J.

    1992-05-01

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  1. Determination of the polarization states of an arbitrary polarized terahertz beam: vectorial vortex analysis.

    Science.gov (United States)

    Wakayama, Toshitaka; Higashiguchi, Takeshi; Oikawa, Hiroki; Sakaue, Kazuyuki; Washio, Masakazu; Yonemura, Motoki; Yoshizawa, Toru; Tyo, J Scott; Otani, Yukitoshi

    2015-03-24

    Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1-1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion, and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.

  2. Theory and analysis of a large field polarization imaging system with obliquely incident light.

    Science.gov (United States)

    Lu, Xiaotian; Jin, Weiqi; Li, Li; Wang, Xia; Qiu, Su; Liu, Jing

    2018-02-05

    Polarization imaging technology provides information about not only the irradiance of a target but also the polarization degree and angle of polarization, which indicates extensive application potential. However, polarization imaging theory is based on paraxial optics. When a beam of obliquely incident light passes an analyser, the direction of light propagation is not perpendicular to the surface of the analyser and the applicability of the traditional paraxial optical polarization imaging theory is challenged. This paper investigates a theoretical model of a polarization imaging system with obliquely incident light and establishes a polarization imaging transmission model with a large field of obliquely incident light. In an imaging experiment with an integrating sphere light source and rotatable polarizer, the polarization imaging transmission model is verified and analysed for two cases of natural light and linearly polarized light incidence. Although the results indicate that the theoretical model is consistent with the experimental results, the theoretical model distinctly differs from the traditional paraxial approximation model. The results prove the accuracy and necessity of the theoretical model and the theoretical guiding significance for theoretical and systematic research of large field polarization imaging.

  3. 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

  4. Building AN International Polar Data Coordination Network

    Science.gov (United States)

    Pulsifer, P. L.; Yarmey, L.; Manley, W. F.; Gaylord, A. G.; Tweedie, C. E.

    2013-12-01

    In the spirit of the World Data Center system developed to manage data resulting from the International Geophysical Year of 1957-58, the International Polar Year 2007-2009 (IPY) resulted in significant progress towards establishing an international polar data management network. However, a sustained international network is still evolving. In this paper we argue that the fundamental building blocks for such a network exist and that the time is right to move forward. We focus on the Arctic component of such a network with linkages to Antarctic network building activities. A review of an important set of Network building blocks is presented: i) the legacy of the IPY data and information service; ii) global data management services with a polar component (e.g. World Data System); iii) regional systems (e.g. Arctic Observing Viewer; iv) nationally focused programs (e.g. Arctic Observing Viewer, Advanced Cooperative Arctic Data and Information Service, Polar Data Catalogue, Inuit Knowledge Centre); v) programs focused on the local (e.g. Exchange for Local Observations and Knowledge of the Arctic, Geomatics and Cartographic Research Centre). We discuss current activities and results with respect to three priority areas needed to establish a strong and effective Network. First, a summary of network building activities reports on a series of productive meetings, including the Arctic Observing Summit and the Polar Data Forum, that have resulted in a core set of Network nodes and participants and a refined vision for the Network. Second, we recognize that interoperability for information sharing fundamentally relies on the creation and adoption of community-based data description standards and data delivery mechanisms. There is a broad range of interoperability frameworks and specifications available; however, these need to be adapted for polar community needs. Progress towards Network interoperability is reviewed, and a prototype distributed data systems is demonstrated. We

  5. Towards helium-3 neutron polarizers

    International Nuclear Information System (INIS)

    Tasset, F.

    1995-01-01

    With a large absorption cross-section entirely due to antiparallel spin capture, polarized helium-3 is presently the most promising broad-band polarizer for thermal and epithermal neutrons. Immediate interest was raised amongst the neutron community when a dense gaseous 3 He polarizer was used for the first time in 1988, on a pulsed neutron beam at Los Alamos. With 20 W of laser power on a 30 cm long, 8.6 atm target, 40% 3 He polarization was achieved in a recent polarized electron scattering experiment at SLAC. In this technique the 3 He nuclei are polarized directly at an appropriate high pressure through spin-exchange collisions with a thick, optically pumped rubidium vapor. A different and competitive approach is being presently developed at Mainz University in collaboration with ENS Paris and now the ILL. A discharge is established in pure 3 He at low pressure producing excited metastable atoms which can be optically pumped with infra-red light. Highly effective exchange collision with the atoms remaining in the ground state quickly produces 75% polarization at 1.5 mbar. A truly non-magnetic system then compresses the polarized gas up to several bars as required. The most recent machine comprises a two-stage glass-titanium compressor. In less than 1 h it can inflate a 100 cm 3 target cell with three bars of polarized gas. The very long relaxation times (several days) now being obtained at high pressure with a special metallic coating on the glass walls, the polarized cell can be detached and inserted in the neutron beam as polarizer. We expect 50% 3 He-polarization to be reached soon, allowing such filters to compete favorably with existing Heusler-crystal polarizers at thermal and short neutron wavelengths. It must be stressed that such a system based on a 3 He polarization factory able to feed several passive, transportable, polarizers is well matched to neutron scattering needs. (orig.)

  6. Physical trajectory profile data from glider ru24 deployed by Korea Polar Research Institute in the Southern Oceans from 2014-01-04 to 2014-01-13 (NCEI Accession 0145708)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — KOPRI is an international collaboration between the Korean Polar Research Institute and Rutgers University to deploy gliders in the Amundsen polynya. The ice sheets...

  7. A circumpolar monitoring framework for polar bears

    Science.gov (United States)

    Vongraven, Dag; Aars, Jon; Amstrup, Steven C.; Atkinson, Stephen N.; Belikov, Stanislav; Born, Erik W.; DeBruyn, T.D.; Derocher, Andrew E.; Durner, George M.; Gill, Michael J.; Lunn, Nicholas J.; Obbard, Martyn E.; Omelak, Jack; Ovsyanikov, Nikita; Peacock, Elizabeth; Richardson, E.E.; Sahanatien, Vicki; Stirling, Ian; Wiig, Øystein

    2012-01-01

    Polar bears (Ursus maritimus) occupy remote regions that are characterized by harsh weather and limited access. Polar bear populations can only persist where temporal and spatial availability of sea ice provides adequate access to their marine mammal prey. Observed declines in sea ice availability will continue as long as greenhouse gas concentrations rise. At the same time, human intrusion and pollution levels in the Arctic are expected to increase. A circumpolar understanding of the cumulative impacts of current and future stressors is lacking, long-term trends are known from only a few subpopulations, and there is no globally coordinated effort to monitor effects of stressors. Here, we describe a framework for an integrated circumpolar monitoring plan to detect ongoing patterns, predict future trends, and identify the most vulnerable polar bear subpopulations. We recommend strategies for monitoring subpopulation abundance and trends, reproduction, survival, ecosystem change, human-caused mortality, human–bear conflict, prey availability, health, stature, distribution, behavioral change, and the effects that monitoring itself may have on polar bears. We assign monitoring intensity for each subpopulation through adaptive assessment of the quality of existing baseline data and research accessibility. A global perspective is achieved by recommending high intensity monitoring for at least one subpopulation in each of four major polar bear ecoregions. Collection of data on harvest, where it occurs, and remote sensing of habitat, should occur with the same intensity for all subpopulations. We outline how local traditional knowledge may most effectively be combined with the best scientific methods to provide comparable and complementary lines of evidence. We also outline how previously collected intensive monitoring data may be sub-sampled to guide future sampling frequencies and develop indirect estimates or indices of subpopulation status. Adoption of this framework

  8. Design Concept of Superconducting Multipole Wiggler with Variably Polarized X-Ray

    International Nuclear Information System (INIS)

    Hwang, C.S.; Chang, C.H.; Li, W.P.; Lin, F.Y.

    2004-01-01

    In response to the growing demand for X-ray research, and to satisfy future needs for generating circularly polarized synchrotron radiation in the X-ray region, a 3.5 T superconducting multipole with a periodic length of 6 cm was designed to produce horizontal linearly polarized, and circularly polarized light on a 1.5 GeV electron storage ring. Differently arranged excitation current loop for the same coil design switched between the operation of symmetric and asymmetric modes to creat the linearly and circularly polarized light, respectively. This study elucidates the design concepts of the superconducting multipole wiggler with symmetric and asymmetric operation modes. The design of the magnetic circuit and the field calculation are also discussed. Meanwhile, the spectra characteristics of the symmetric and asymmetric modes are calculated and presented in this article

  9. 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.

  10. Polar bears: the fate of an icon.

    Science.gov (United States)

    Fitzgerald, Kevin T

    2013-11-01

    Polar bears are one of the most iconic animals on our planet. Worldwide, even people who would never see one are drawn to these charismatic arctic ice hunters. They are the world's largest terrestrial carnivore, and despite being born on land, they spend most of their lives out on the sea ice and are considered a marine mammal. Current global studies estimate there are around 20,000 animals in some 19 discrete circumpolar populations. Aside from pregnant females denning in the winter months to give birth, the white bears do not hibernate. They spend their winters on the sea ice hunting seals, an activity they are spectacularly adapted for. Research on these animals is incredibly difficult because of the inhospitable surroundings they inhabit and how inaccessible they make the bears. For many years, the sum of our understanding of the natural history of polar bears came from tracks, scats, the remains of their kills, abandoned dens, and anecdotal observations of native hunters, explorers, and early biologists. Nonetheless, the last 40 years have seen a much better picture of their biology emerge thanks to, first, dedicated Canadian researchers and, later, truly international efforts of workers from many countries. Veterinarians have contributed to our knowledge of the bears by delivering and monitoring anesthesia, obtaining blood samples, performing necropsies, investigating their reproduction, conducting radiotelemetry studies, and examining their behavior. Recently, new technologies have been developed that revolutionize the study of the lives and natural history of undisturbed polar bears. These advances include better satellite radiotelemetry equipment and the development of remote-controlled miniature devices equipped with high-definition cameras. Such new modalities provide dramatic new insights into the life of polar bears. The remarkable degree of specialized adaptation to life on the sea ice that allowed the bears to be successful is the very reason that

  11. Polarized target as analyzer of polarization of particle beam with spin Ssub(B)=1/2

    International Nuclear Information System (INIS)

    Golovin, V.M.; Golubeva, M.B.; Gornushkin, Yu.A.

    1982-01-01

    A possibility of using a polarized target as a target analyzer of beam particle polarization (Ssub(T)=1/2 Psub(T) vector) so that all the components of beam polarization Ssub(B)=1/2 anti Psub(B) should be determined in one experiment, is revealed. A proton polarization target is considered as a polarization target-analyzer. Asub(SK) and Asub(kk) asymmetry tensors are considered for elastic pp and pn scatterings by amplitudes of NN scattering which attain the values of 0.3-0.9 at 95-400 MeV. Asub(kk)(pp) and Asub(sk)(pp) are experimentally measured in the 445-576 MeV range. It is found that their highest absolute values are equal to 0.4-0.5 and 0.2-0.3 respectively. Elastic proton scattering on polarized electrons may be another variant of using polarized target for measuring proton beam polarization. Asub(sk) and Asub(kk) components of asymmetry tensor of elastic pe scattering are graphically presented. A possibility of using a polarized charge with spin I=1/2 as a target-analyzer of particle beam polarization is marked

  12. Improving Broader Impacts through Researcher-Educator Partnerships

    Science.gov (United States)

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

    2009-12-01

    Since 1998, the Arctic Research Consortium of the United States (ARCUS) has designed and implemented successful Teacher Research Experience (TRE) programs enabling teachers to work directly with polar scientists in the field and bring their experience back to their classrooms and communities. The PolarTREC TRE model, administered during the International Polar Year (2007-2009), is most effective, exhibiting far-reaching broader impacts when ideas are shared, each partners’ expertise is respected, and both work toward the common goal of delivering high-quality information. Between 2004 and 2009, ARCUS has selected, trained, and supported 77 teachers on polar teacher research experiences. Although a limited number of teachers are able to participate in a field experience, selected teachers have expertise in translating research approaches and results into widely shared learning tools and programs. Between 2007-2009, PolarTREC teachers have constructed nearly 100 classroom lesson plans and activities as a result of their experience. Selected teachers are usually well connected within their schools, communities, and professions, bringing the science to numerous followers during their expedition. Live events with teachers and researchers in the field have attracted over 11,000 participants, primarily K-12 students. The PolarTREC TRE Model includes numerous methods to support outreach activities while teachers and researchers are in the field. These include web-based communications, journals, discussion forums, multimedia, and live events—all easily replicable activities with the potential to affect large numbers of people. In addition, the TRE experience continues to produce broader impacts far into the future of the teacher and researcher’s careers through ongoing communications, presentations at professional conferences, and continued support of each other’s work through activities including classroom visits, joint proposal development, and much more

  13. Target recognition of log-polar ladar range images using moment invariants

    Science.gov (United States)

    Xia, Wenze; Han, Shaokun; Cao, Jie; Yu, Haoyong

    2017-01-01

    The ladar range image has received considerable attentions in the automatic target recognition field. However, previous research does not cover target recognition using log-polar ladar range images. Therefore, we construct a target recognition system based on log-polar ladar range images in this paper. In this system combined moment invariants and backpropagation neural network are selected as shape descriptor and shape classifier, respectively. In order to fully analyze the effect of log-polar sampling pattern on recognition result, several comparative experiments based on simulated and real range images are carried out. Eventually, several important conclusions are drawn: (i) if combined moments are computed directly by log-polar range images, translation, rotation and scaling invariant properties of combined moments will be invalid (ii) when object is located in the center of field of view, recognition rate of log-polar range images is less sensitive to the changing of field of view (iii) as object position changes from center to edge of field of view, recognition performance of log-polar range images will decline dramatically (iv) log-polar range images has a better noise robustness than Cartesian range images. Finally, we give a suggestion that it is better to divide field of view into recognition area and searching area in the real application.

  14. On the large COMPASS polarized deuteron target

    Czech Academy of Sciences Publication Activity Database

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

    2006-01-01

    Roč. 56, Suppl. F (2006), F295-F305 ISSN 0011-4626 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : COMPASS * polarized target * Dilution refrigerator Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.568, year: 2006

  15. Calculation of polarization effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful

  16. International Field School on Permafrost, Polar Urals, 2012

    Science.gov (United States)

    Streletskiy, D. A.; Grebenets, V.; Ivanov, M.; Sheinkman, V.; Shiklomanov, N. I.; Shmelev, D.

    2012-12-01

    The international field school on permafrost was held in the Polar Urals region from June, 30 to July 9, 2012 right after the Tenth International Conference on Permafrost which was held in Salekhard, Russia. The travel and accommodation support generously provided by government of Yamal-Nenets Autonomous Region allowed participation of 150 permafrost young research scientists, out of which 35 students from seven countries participated in the field school. The field school was organized under umbrella of International Permafrost Association and Permafrost Young Research Network. The students represented diverse educational backgrounds including hydrologists, engineers, geologists, soil scientists, geocryologists, glaciologists and geomorphologists. The base school camp was located near the Harp settlement in the vicinity of Polar Urals foothills. This unique location presented an opportunity to study a diversity of cryogenic processes and permafrost conditions characteristic for mountain and plain regions as well as transition between glacial and periglacial environments. A series of excursions was organized according to the following topics: structural geology of the Polar Urals and West Siberian Plain (Chromite mine "Centralnaya" and Core Storage in Labitnangy city); quaternary geomorphology (investigation of moraine complexes and glacial conditions of Ronamantikov and Topographov glaciers); principles of construction and maintains of structures built on permafrost (Labitnangy city and Obskaya-Bovanenkovo Railroad); methods of temperature and active-layer monitoring in tundra and forest-tundra; cryosols and soil formation in diverse landscape condition; periglacial geomorphology; types of ground ice, etc. Every evening students and professors gave a series of presentations on climate, vegetation, hydrology, soil conditions, permafrost and cryogenic processes of the region as well as on history, economic development, endogenous population of the Siberia and the

  17. Preliminary Analysis of Chinese GF-3 SAR Quad-Polarization Measurements to Extract Winds in Each Polarization

    Directory of Open Access Journals (Sweden)

    Lin Ren

    2017-11-01

    Full Text Available This study analyzed the noise equivalent sigma zero (NESZ and ocean wind sensitivity for Chinese C-band Gaofen-3 (GF-3 quad-polarization synthetic aperture radar (SAR measurements to facilitate further operational wind extraction from GF-3 data. Data from the GF-3 quad-polarization SAR and collocated winds from both NOAA/NCEP Global Forecast System (GFS atmospheric model and National Data Buoy Center (NDBC buoys were used in the analysis. For NESZ, the co-polarization was slightly higher compared to the cross-polarization. Regarding co-polarization and cross-polarization, NESZ was close to RadarSAT-2 and Sentinel-1 A. Wind sensitivity was analyzed by evaluating the dependence on winds in terms of normalized radar cross-sections (NRCS and polarization combinations. The closest geophysical model function (GMF and the polarization ratio (PR model to GF-3 data were determined by comparing data and the model results. The dependence of co-polarized NRCS on wind speed and azimuth angle was consistent with the proposed GMF models. The combination of CMOD5 and CMOD5.N was considered to be the closest GMF in co-polarization. The cross-polarized NRCS exhibited a strong linear relationship with moderate wind speeds higher than 4 m·s−1, but a weak correlation with the azimuth angle. The proposed model was considered as the closest GMF in cross-polarization. For polarization combinations, PR and polarization difference (PD were considered. PR increased only with the incidence angle, whereas PD increased with wind speed and varied with azimuth angle. There were three very close PR models and each can be considered as the closest. Preliminary results indicate that GF-3 quad-polarization data are valid and have the ability to extract winds in each polarization.

  18. Development of a cryogenic source of polarized deuterons ''Polaris''

    International Nuclear Information System (INIS)

    Anishchenko, N.G.; Belushkina, A.A.; Ershov, V.P.

    1985-01-01

    To obtain a beam of polarized deuterons, a cryogenic source ''Polaris'' has been developed according to the program of research at the Dubna synchrophasotron. The source is installed on a high-voltage terminal of the linac preaccelerator. A beam of deuterons from the source is accelerated in the synchrophasotron. At present the source is being improved. A polarimeter with 3 He and 4 He targets has been developed to measure the polarization of the beam of deuterons after the linac. Results of this work are presented in the report

  19. [Intermediate energy studies of polarization transfer, polarized deuteron scattering, and (p,π+-) reactions: Rapporteur's report

    International Nuclear Information System (INIS)

    Moss, J.M.

    1985-01-01

    An overview of intermediate energy (80 to 1000 MeV) study contributions to the International Polarization Symposium in Osaka, Japan, August 1985 is presented in this report. Contributions fall into three categories: polarization transfer, polarized deuteron scattering and polarized (p,π +- ) reactions

  20. 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

  1. 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)

  2. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  3. 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...

  4. Development of polarized {sup 3}He filter for polarized neutron experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, K.; Sato, H.; Yoshimi, A.; Asahi, K. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Masuda, Y.; Muto, S.; Ishimoto, S.; Morimoto, K.

    1996-08-01

    A high-pressure polarized {sup 3}He gas cell, pumped with two diode lasers, has been developed at KEK for use as a polarizer and a spin analyzer for low energy neutrons. The polarization attained of {sup 3}He was determined through the measurement of the transmission of the unpolarized neutrons through the {sup 3}He cell. So far we obtained P{sub He}=18% at 10 atm and P{sub He}=12% at 20 atm. (author)

  5. International Space Station Research and Facilities for Life Sciences

    Science.gov (United States)

    Robinson, Julie A.; Ruttley, Tara M.

    2009-01-01

    Assembly of the International Space Station is nearing completion in fall of 2010. Although assembly has been the primary objective of its first 11 years of operation, early science returns from the ISS have been growing at a steady pace. Laboratory facilities outfitting has increased dramatically 2008-2009 with the European Space Agency s Columbus and Japanese Aerospace Exploration Agency s Kibo scientific laboratories joining NASA s Destiny laboratory in orbit. In May 2009, the ISS Program met a major milestone with an increase in crew size from 3 to 6 crewmembers, thus greatly increasing the time available to perform on-orbit research. NASA will launch its remaining research facilities to occupy all 3 laboratories in fall 2009 and winter 2010. To date, early utilization of the US Operating Segment of the ISS has fielded nearly 200 experiments for hundreds of ground-based investigators supporting international and US partner research. With a specific focus on life sciences research, this paper will summarize the science accomplishments from early research aboard the ISS- both applied human research for exploration, and research on the effects of microgravity on life. We will also look ahead to the full capabilities for life sciences research when assembly of ISS is complete in 2010.

  6. Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

    International Nuclear Information System (INIS)

    Choi, Yunju; Kim, Yangsoo; Ahn, Kwang-Soon; Kim, Hyunsoo

    2014-01-01

    Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10 −3 , 4.3 × 10 −4 , and 1.1 × 10 −3 Ω cm 2 for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N 2 ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples

  7. Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yunju [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Kim, Yangsoo [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Ahn, Kwang-Soon, E-mail: kstheory@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Kim, Hyunsoo, E-mail: hskim7@jbnu.ac.kr [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2014-10-30

    Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10{sup −3}, 4.3 × 10{sup −4}, and 1.1 × 10{sup −3} Ω cm{sup 2} for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N{sub 2} ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples.

  8. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  9. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from COLUMBUS ISELIN, ENDEAVOR and others in the Coastal Waters of Florida, North Atlantic Ocean and South Atlantic Ocean from 1993-05-11 to 1996-10-17 (NODC Accession 0051984)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0051984 includes Surface underway, chemical and physical data collected from COLUMBUS ISELIN, ENDEAVOR, GYRE, OCEANUS and SEWARD JOHNSON in the...

  10. A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words

    Directory of Open Access Journals (Sweden)

    Bingkun Wang

    2015-01-01

    Full Text Available With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods.

  11. A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words

    Science.gov (United States)

    Huang, Yongfeng; Wu, Xian; Li, Xing

    2015-01-01

    With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods. PMID:26106409

  12. Characterization of RF-spittered self-polarized PZT thin films for sensors arrays

    Czech Academy of Sciences Publication Activity Database

    Suchaneck, G.; Lin, W. M.; Koehler, R.; Sandner, T.; Gerlach, G.; Krawietz, R.; Pompe, W.; Deineka, Alexander; Jastrabík, Lubomír

    2002-01-01

    Roč. 66, - (2002), s. 473-478 ISSN 0042-207X R&D Projects: GA MŠk LN00A015; GA ČR GA202/00/1425 Institutional research plan: CEZ:AV0Z1010914 Keywords : self-polarized PZT * polarization and refractive index profiles * IR sensor array Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.723, year: 2002

  13. 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

    Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

  14. Asymptotic behaviour in polarized and half-polarized U(1) symmetric vacuum spacetimes

    International Nuclear Information System (INIS)

    Isenberg, James; Moncrief, Vincent

    2002-01-01

    We use the Fuchsian algorithm to study the behaviour near the singularity of certain families of U(1) symmetric solutions of the vacuum Einstein equations (with the U(1) isometry group acting spatially). We consider an analytic family of polarized solutions with the maximum number of arbitrary functions consistent with the polarization condition (one of the 'gravitational degrees of freedom' is turned off) and show that all members of this family are asymptotically velocity term dominated (AVTD) as one approaches the singularity. We show that the same AVTD behaviour holds for a family of 'half-polarized' solutions, which is defined by adding one extra arbitrary function to those characterizing the polarized solutions. (The full set of nonpolarized solutions involves two extra arbitrary functions.) Using SL(2, R) Geroch transformations, we produce a further class of U(1) symmetric solutions with AVTD behaviour. We begin to address the issue of whether AVTD behaviour is independent of the choice of time foliation by showing that indeed AVTD behaviour is seen for a wide class of choices of harmonic time in the polarized and half-polarized (U(1) symmetric vacuum) solutions discussed here

  15. 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)

  16. FDTD simulation of trapping nanowires with linearly polarized and radially polarized optical tweezers.

    Science.gov (United States)

    Li, Jing; Wu, Xiaoping

    2011-10-10

    In this paper a model of the trapping force on nanowires is built by three dimensional finite-difference time-domain (FDTD) and Maxwell stress tensor methods, and the tightly focused laser beam is expressed by spherical vector wave functions (VSWFs). The trapping capacities on nanoscale-diameter nanowires are discussed in terms of a strongly focused linearly polarized beam and radially polarized beam. Simulation results demonstrate that the radially polarized beam has higher trapping efficiency on nanowires with higher refractive indices than linearly polarized beam.

  17. Polarization Property Measurement of the Long Undulator Radiation Using Cr/C Multilayer Polarization Elements

    International Nuclear Information System (INIS)

    Niibe, Masahito; Mukai, Mikihito; Shoji, Yoshihiko; Kimura, Hiroaki

    2004-01-01

    A rotating analyzer ellipsometry (RAE) system was developed with Cr/C multilayers that function as polarization elements for photon energy range of 110 - 280 eV. Polarization properties of a planar undulator change axisymmetrically in off-axial manner, and the second harmonic is more remarkable for the change. By using the RAE system, the polarization property of the second harmonic radiation from the NewSUBARU long undulator at the energy of 180 eV was examined. The degree of linear polarization of the on-axis radiation was over 0.996. The spatial distribution of the polarization azimuth was measured and was in fair agreement with the theoretical calculation. A peculiar behavior of the polarization property near the radiation peak of the second harmonic was observed by changing the height of the undulator gap

  18. 76 FR 59162 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-National Center...

    Science.gov (United States)

    2011-09-23

    .... Specifically, Anglicotech LLC, Washington, DC; Battelle, Columbus, OH; Baxter Healthcare Corporation, Round...; ARC Technology Solutions, LLC, Nashua, NH; BAE Systems, Wayne, NJ; BCT Technology, Inc., Keene, NH...

  19. The evolution of tensor polarization

    International Nuclear Information System (INIS)

    Huang, H.; Lee, S.Y.; Ratner, L.

    1993-01-01

    By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

  20. System for measuring of proton polarization in polarized target

    International Nuclear Information System (INIS)

    Derkach, A.Ya.; Lukhanin, A.A.; Karnaukhov, I.M.; Kuz'menko, V.S.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

    1981-01-01

    Measurement system of proton polarization in the target, which uses the method of nuclear magnetic resonance is described. To record the signal of NMR-absorption a parallel Q-meter of voltage with analogous subtraction of resonance characteristics of measurement circuit is used. To obtain gradual sensitivity of the system to polarization state in the whole volume of the target the measurement coils is made of tape conductor. The analysis and mathematical modelling of Q-meter are carried out. Corrections for nonlinearity and dispersion are calculated. Key diagrams of the main electron blocks of Q-meter are presented. The system described operates on line with the M6000 computer. Total error of measurement of polarization value of free protons in the target does not exceed 6% [ru

  1. Polarization experiments

    International Nuclear Information System (INIS)

    Halzen, F.

    1977-02-01

    In a theoretical review of polarization experiments two important points are emphasized: (a) their versatility and their relevance to a large variety of aspects of hadron physics (tests of basic symmetries; a probe of strong interaction dynamics; a tool for hadron spectroscopy); (b) the wealth of experimental data on polarization parameters in pp and np scattering in the Regge language and in the diffraction language. (author)

  2. Study of Jupiter polarization properties

    International Nuclear Information System (INIS)

    Bolkvadze, O.R.

    1980-01-01

    Investigations into polarization properties of the Jupiter reflected light were carried on at the Abastumani astrophysical observatory in 1967, 1968 and 1969 in the four spectral ranges: 4000, 4800, 5400 and 6600 A deg. Data on light polarization in different parts of the Jupiter visible disk are given. Curves of dependence of the planet light polarization degree on a phase angle are plotted. It is shown that in the central part of the visible planet disk the polarization degree is low. Atmosphere is in a stable state in this part of Jupiter. Mean radius of particles of a cloud layer is equal to 0.26μ, and optical thickness of overcloud atmosphere tau=0.05. Height of transition boundary of the cloud layer into overcloud gas atmosphere changes from year to year at the edges of the equatorial zone. Optical thickness of overcloud atmosphere changes also with changing height of a transient layer. The polar Jupiter regions possess a high degree of polarization which depends on a latitude. Polarization increases monotonously with the latitude and over polar regions accepts a maximum value [ru

  3. Physical trajectory profile data from glider ru25d deployed by Korea Polar Research Institute in the Southern Oceans from 2014-01-04 to 2014-01-13 (NCEI Accession 0145709)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — KOPRI is an international collaboration between the Korean Polar Research Institute and Rutgers University to deploy gliders in the Amundsen polynya. The ice sheets...

  4. Physical trajectory profile data from glider ru25d deployed by Korea Polar Research Institute in the Southern Oceans from 2016-01-21 to 2016-02-06 (NCEI Accession 0153546)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — KOPRI is an international collaboration between the Korean Polar Research Institute and Rutgers University to deploy gliders in the Amundsen polynya. The ice sheets...

  5. Mercury and cortisol in Western Hudson Bay polar bear hair.

    Science.gov (United States)

    Bechshoft, T; Derocher, A E; Richardson, E; Mislan, P; Lunn, N J; Sonne, C; Dietz, R; Janz, D M; St Louis, V L

    2015-08-01

    Non-invasive methods of assessing animal health and life history are becoming increasingly popular in wildlife research; hair samples from polar bears (Ursus maritimus), are being used to study an ever broader range of anthropogenic and endocrine compounds. A number of contaminants are known to disrupt endocrine function in polar bears. However, the relationship between mercury and cortisol remains unknown, although mercury is an endocrine disruptor in other species. Here, we examine the relationship between concentrations of cortisol and total mercury (THg) analyzed in guard hair from 378 polar bears (184 females, 194 males) sampled in Western Hudson Bay, 2004-2012. The difference in mean cortisol concentration between female (0.8 ± 0.6 pg/mg) and male (0.7 ± 0.5 pg/mg) polar bears bordered on significance (p = 0.054). However, mean mercury concentration was significantly greater (p = 0.009) in females (4.7 ± 1.4 μg/g) than males (4.3 ± 1.2 μg/g). Hair cortisol in males was significantly influenced by mercury, age, and fatness, as well as interactions between mercury and year, mercury and fatness, and year and fatness (all: p polar bears.

  6. High energy polarized electron beams

    International Nuclear Information System (INIS)

    Rossmanith, R.

    1987-01-01

    In nearly all high energy electron storage rings the effect of beam polarization by synchrotron radiation has been measured. The buildup time for polarization in storage rings is of the order of 10 6 to 10 7 revolutions; the spins must remain aligned over this time in order to avoid depolarization. Even extremely small spin deviations per revolution can add up and cause depolarization. The injection and the acceleration of polarized electrons in linacs is much easier. Although some improvements are still necessary, reliable polarized electron sources with sufficiently high intensity and polarization are available. With the linac-type machines SLC at Stanford and CEBAF in Virginia, experiments with polarized electrons will be possible

  7. Interferometric polarization control

    International Nuclear Information System (INIS)

    Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

    2006-01-01

    We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results

  8. Cryogenic polarized-target facility. Progress report, July 1, 1981-June 30, 1982

    International Nuclear Information System (INIS)

    Gould, C.R.; Haase, D.G.

    1982-01-01

    The goal of this three-year research project is to build a cryogenically polarized target facility for measuring total neutron cross sections for polarized neutrons incident on polarized nuclei. The components of the system have been assembled at TUNL during the current contract period. These include the dilution-refrigerator support assembly, the dilution-refrigerator itself, the dewar, the beam line, the shielding cave for the neutron source, and the neutron-detector shield and rolling-cart assembly. The dilution refrigerator is presently undergoing testing at liquid-nitrogen and liquid-helium temperatures. Experiments with aluminum and copper targets are scheduled for the coming contract period

  9. Photonic Crystal Polarizing and Non-Polarizing Beam Splitters

    International Nuclear Information System (INIS)

    Chun-Ying, Guan; Jin-Hui, Shi; Li-Boo, Yuan

    2008-01-01

    A polarizing beam splitter (PBS) and a non-polarizing beam splitter (NPBS) based on a photonic crystal (PC) directional coupler are demonstrated. The photonic crystal directional coupler consists of a hexagonal lattice of dielectric pillars in air and has a complete photonic band gap. The photonic band structure and the band gap map are calculated using the plane wave expansion (PWE) method. The splitting properties of the splitter are investigated numerically using the finite difference time domain (FDTD) method

  10. Sentiment Polarization and Balance among Users in Online Social Networks

    DEFF Research Database (Denmark)

    Hillmann, Robert; Trier, Matthias

    2012-01-01

    Communication within online social network applications enables users to express and share sentiments electronically. Existing studies examined the existence or distribution of sentiments in online communication at a general level or in small-observed groups. Our paper extends this research...... by analyzing sentiment exchange within social networks from an ego-network perspective. We draw from research on social influence and social attachment to develop theories of node polarization, balance effects and sentiment mirroring within communication dyads. Our empirical analysis covers a multitude...... of social networks in which the sentiment valence of all messages was determined. Subsequently we studied ego-networks of focal actors (ego) and their immediate contacts. Results support our theories and indicate that actors develop polarized sentiments towards individual peers but keep sentiment in balance...

  11. Recent results on polarizations and the present status of the Fermilab polarized beams

    International Nuclear Information System (INIS)

    Yokosawa, Akihiko.

    1986-01-01

    Experimental results are reviewed on polarization phenomena in nucleon-nucleon scattering at intermediate energies. The present status of S = 0 dibaryon resonances is presented. The status of the Fermilab polarized beam program is presented, including the construction of polarized beam, two polarimeters being installed in the experimental hall, and the experimental program

  12. Reciprocal and dynamic polarization of planar cell polarity core components and myosin

    Science.gov (United States)

    Newman-Smith, Erin; Kourakis, Matthew J; Reeves, Wendy; Veeman, Michael; Smith, William C

    2015-01-01

    The Ciona notochord displays planar cell polarity (PCP), with anterior localization of Prickle (Pk) and Strabismus (Stbm). We report that a myosin is polarized anteriorly in these cells and strongly colocalizes with Stbm. Disruption of the actin/myosin machinery with cytochalasin or blebbistatin disrupts polarization of Pk and Stbm, but not of myosin complexes, suggesting a PCP-independent aspect of myosin localization. Wash out of cytochalasin restored Pk polarization, but not if done in the presence of blebbistatin, suggesting an active role for myosin in core PCP protein localization. On the other hand, in the pk mutant line, aimless, myosin polarization is disrupted in approximately one third of the cells, indicating a reciprocal action of core PCP signaling on myosin localization. Our results indicate a complex relationship between the actomyosin cytoskeleton and core PCP components in which myosin is not simply a downstream target of PCP signaling, but also required for PCP protein localization. DOI: http://dx.doi.org/10.7554/eLife.05361.001 PMID:25866928

  13. Research on Copy-Move Image Forgery Detection Using Features of Discrete Polar Complex Exponential Transform

    Science.gov (United States)

    Gan, Yanfen; Zhong, Junliu

    2015-12-01

    With the aid of sophisticated photo-editing software, such as Photoshop, copy-move image forgery operation has been widely applied and has become a major concern in the field of information security in the modern society. A lot of work on detecting this kind of forgery has gained great achievements, but the detection results of geometrical transformations of copy-move regions are not so satisfactory. In this paper, a new method based on the Polar Complex Exponential Transform is proposed. This method addresses issues in image geometric moment, focusing on constructing rotation invariant moment and extracting features of the rotation invariant moment. In order to reduce rounding errors of the transform from the Polar coordinate system to the Cartesian coordinate system, a new transformation method is presented and discussed in detail at the same time. The new method constructs a 9 × 9 shrunk template to transform the Cartesian coordinate system back to the Polar coordinate system. It can reduce transform errors to a much greater degree. Forgery detection, such as copy-move image forgery detection, is a difficult procedure, but experiments prove our method is a great improvement in detecting and identifying forgery images affected by the rotated transform.

  14. Frequency and Polarization Diversity Jamming of Communications in Urban Environments

    National Research Council Canada - National Science Library

    Ulama, Tuncay

    2005-01-01

    The purpose of this research is to investigate how to exploit frequency and polarization techniques in reducing the effects of jamming against UAV relay communication links in an urban warfare environment...

  15. Polarization transfer from polarized nuclear spin to μ- spin in muonic atom

    International Nuclear Information System (INIS)

    Kuno, Yoshitaka; Nagamine, Kanetada; Yamazaki, Toshimitsu.

    1987-02-01

    A theoretical study of polarization transfer from an initially-polarized nuclear spin to a μ - spin in a muonic atom is given. The switching of the hyperfine interaction at excited muonic states as well as at the ground 1s state is taken into account. The upper state of hyperfine doublet at the muonic 1s state is considered to proceed down to the lower state. It is found that as the hyperfine interaction becomes effective at higher excited muonic orbitals, a less extent of polarization is transferred from the nuclear spin to the μ - spin. The theoretical values obtained are compared with the recent experiment of μ - repolarization in a polarized 209 Bi target. (author)

  16. Electroproduction of polarized Λ's

    International Nuclear Information System (INIS)

    Kunne, R.A.

    1992-01-01

    Lambdas are a powerful tool to explore spin effects of QCD. The λ polarization is self analyzing, as it is measurable from the angular distribution of the decay products. Two applications of polarized electroproduced λ's are suggested: the measurement of λ polarization at large transverse momentum as a possible test of QCD and the measurement of transversely polarized parton distributions

  17. Linearly polarized emission from an embedded quantum dot using nanowire morphology control.

    Science.gov (United States)

    Foster, Andrew P; Bradley, John P; Gardner, Kirsty; Krysa, Andrey B; Royall, Ben; Skolnick, Maurice S; Wilson, Luke R

    2015-03-11

    GaAs nanowires with elongated cross sections are formed using a catalyst-free growth technique. This is achieved by patterning elongated nanoscale openings within a silicon dioxide growth mask on a (111)B GaAs substrate. It is observed that MOVPE-grown vertical nanowires with cross section elongated in the [21̅1̅] and [1̅12] directions remain faithful to the geometry of the openings. An InGaAs quantum dot with weak radial confinement is realized within each nanowire by briefly introducing indium into the reactor during nanowire growth. Photoluminescence emission from an embedded nanowire quantum dot is strongly linearly polarized (typically >90%) with the polarization direction coincident with the axis of elongation. Linearly polarized PL emission is a result of embedding the quantum dot in an anisotropic nanowire structure that supports a single strongly confined, linearly polarized optical mode. This research provides a route to the bottom-up growth of linearly polarized single photon sources of interest for quantum information applications.

  18. Polarized proton collider at RHIC

    International Nuclear Information System (INIS)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N.

    2003-01-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

  19. Optical properties of polarization-dependent geometrical phase elements with partially polarized light

    International Nuclear Information System (INIS)

    Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

    2005-01-01

    Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

  20. An L-Band Polarized Electron PWT Photoinjector for the International Linear Collider (ILC)

    CERN Document Server

    Yu, David; Chen Ping; Lundquist, Martin; Luo, Yan; Smirnov, Alexei Yu

    2005-01-01

    A multi-cell, standing-wave, L-band, p-mode, plane-wave-transformer (PWT) photoinjector with an integrated photocathode in a novel linac structure is proposed by DULY Research Inc. as a polarized electron source. The PWT photoinjector is capable of operation in ultra high vacuum and moderate field gradient. Expected performance of an L-band polarized electron PWT injector operating under the parameters for the International Linear Collider is presented. The projected normalized transverse rms emittance is an order of magnitude lower than that produced with a polarized electron dc gun followed by subharmonic bunchers.

  1. POLARIZED BEAMS: 2 - Partial Siberian Snake rescues polarized protons at Brookhaven

    International Nuclear Information System (INIS)

    Huang, Haixin

    1994-01-01

    To boost the level of beam polarization (spin orientation), a partial 'Siberian Snake' was recently used to overcome imperfection depolarizing resonances in the Brookhaven Alternating Gradient Synchrotron (AGS). This 9-degree spin rotator recently permitted acceleration with no noticeable polarization loss. The intrinsic AGS depolarizing resonances (which degrade the polarization content) had been eliminated by betatron tune jumps, but the imperfection resonances were compensated by means of harmonic orbit corrections. However, at high energies these orbit corrections are difficult and tedious and a Siberian Snake became an attractive alternative

  2. Nuclear physics with polarized particles

    CERN Document Server

    Paetz gen Schieck, Hans

    2012-01-01

    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory-a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear rea...

  3. 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)

  4. 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.

  5. The Sub-Polar Gyre Index - a community data set for application in fisheries and environment research

    DEFF Research Database (Denmark)

    Berx, Barbara; Payne, Mark

    2017-01-01

    Scientific interest in the sub-polar gyre of the North Atlantic Ocean has increased in recent years. The sub-polar gyre has contracted and weakened, and changes in circulation pathways have been linked to changes in marine ecosystem productivity. To aid fisheries and environmental scientists, we...... series length are explored but found not to be important factors in terms of the SPG-I's interpretation. Our time series compares well with indices presented previously. The SPG-I time series is freely available online (http://dx.doi.org/10.7489/1806-1), and we invite the community to access, apply...

  6. Stanford polarized atomic beam target

    International Nuclear Information System (INIS)

    Mavis, D.G.; Dunham, J.S.; Hugg, J.W.; Glavish, H.F.

    1976-01-01

    A polarized atomic beam source was used to produce an atomic hydrogen beam which was in turn used as a polarized proton target. A target density of 2 x 10'' atoms/cm 3 and a target polarization of 0.37 without the use of rf transitions were measured. These measurements indicate that a number of experiments are currently feasible with a variety of polarized target beams

  7. The University of Delaware Carlson International Polar Year Events: Collaborative and Educational Outreach

    Science.gov (United States)

    Nelson, F. E.; Bryant, T.; Wellington, P.; Dooley, J.; Bird, M.

    2008-12-01

    Delaware is a small state with, by virtue of its coastal location, a large stake in climatic change in the polar regions. The University of Delaware has maintained a strong presence in cold-regions research since the mid-1940s, when William Samuel Carlson, a highly accomplished Arctic explorer, military strategist, and earth scientist, was named 20th President (1946-50) of the University. Carlson played a leading role in two of the University of Michigan's Greenland expeditions in the late 1920s and early 1930s. As Director of the Arctic, Desert, and Tropic Branch of the US Army Air Forces Tactical Center during World War II, Colonel Carlson played a role in developing several air transportation routes through the Arctic that helped to facilitate the Allied victory in Europe. Carlson authored many scientific and popular publications concerned with the Arctic, including the books Greenland Lies North (1940) and Lifelines Through the Arctic (1962). Although the University of Delaware has maintained a vigorous and continuous program of polar research since Carlson's tenure, the faculty, staff, and students involved are diffused throughout the University's colleges and departments, without an institutional focal point. Consequently, although many of these individuals are well known in their respective fields, the institution has not until recently been perceived widely as a center of polar-oriented research. The goals of the Carlson International Polar Year Events are to: (a) develop a sense of community among UD's diffuse polar-oriented researchers and educators; (b) create a distinctive and highly visible role for UD in the milieu of IPY activities; (c) promote interest in and knowledge about the polar regions in the State of Delaware, at all educational levels; (d) forge a close relationship between UD and the American Geographical Society, a national organization involved closely with previous International Polar Years; and (e) create a new basis for development

  8. Solar Spectral Lines with Special Polarization Properties for the Calibration of Instrument Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.; Casini, R.; Alemán, T. del Pino; Judge, P. G. [High Altitude Observatory, National Center for Atmospheric Research 1, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2017-10-20

    We investigate atomic transitions that have previously been identified as having zero polarization from the Zeeman effect. Our goal is to identify spectral lines that can be used for the calibration of instrumental polarization of large astronomical and solar telescopes, such as the Daniel K. Inouye Solar Telescope, which is currently under construction on Haleakala. We use a numerical model that takes into account the generation of scattering polarization and its modification by the presence of a magnetic field of arbitrary strength. We adopt values for the Landé factors from spectroscopic measurements or semi-empirical results, thus relaxing the common assumption of LS-coupling previously used in the literature. The mechanisms dominating the polarization of particular transitions are identified, and we summarize groups of various spectral lines useful for the calibration of spectropolarimetric instruments, classified according to their polarization properties.

  9. Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

    Science.gov (United States)

    Naramoto, Satoshi

    2017-12-01

    Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  11. Emergent chirality in the electric polarization texture of titanate superlattices.

    Science.gov (United States)

    Shafer, Padraic; García-Fernández, Pablo; Aguado-Puente, Pablo; Damodaran, Anoop R; Yadav, Ajay K; Nelson, Christopher T; Hsu, Shang-Lin; Wojdeł, Jacek C; Íñiguez, Jorge; Martin, Lane W; Arenholz, Elke; Junquera, Javier; Ramesh, Ramamoorthy

    2018-01-30

    Chirality is a geometrical property by which an object is not superimposable onto its mirror image, thereby imparting a handedness. Chirality determines many important properties in nature-from the strength of the weak interactions according to the electroweak theory in particle physics to the binding of enzymes with naturally occurring amino acids or sugars, reactions that are fundamental for life. In condensed matter physics, the prediction of topologically protected magnetic skyrmions and related spin textures in chiral magnets has stimulated significant research. If the magnetic dipoles were replaced by their electrical counterparts, then electrically controllable chiral devices could be designed. Complex oxide BaTiO 3 /SrTiO 3 nanocomposites and PbTiO 3 /SrTiO 3 superlattices are perfect candidates, since "polar vortices," in which a continuous rotation of ferroelectric polarization spontaneously forms, have been recently discovered. Using resonant soft X-ray diffraction, we report the observation of a strong circular dichroism from the interaction between circularly polarized light and the chiral electric polarization texture that emerges in PbTiO 3 /SrTiO 3 superlattices. This hallmark of chirality is explained by a helical rotation of electric polarization that second-principles simulations predict to reside within complex 3D polarization textures comprising ordered topological line defects. The handedness of the texture can be topologically characterized by the sign of the helicity number of the chiral line defects. This coupling between the optical and novel polar properties could be exploited to encode chiral signatures into photon or electron beams for information processing.

  12. Polarized deuteron elastic scattering from a polarized proton target

    International Nuclear Information System (INIS)

    Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R.; Zankel, H.

    1983-01-01

    Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76 0 ,85 0 ,98 0 ,115 0 ,132 0 ). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results. (orig.)

  13. 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?

  14. Psychrophilic and Psychrotolerant Microbial Extremophiles in Polar Environments

    Science.gov (United States)

    Hoover, Richard B.; Pikuta, Elena V.

    2010-01-01

    The microbial extremophiles that inhabit the polar regions of our planet are of tremendous significance. The psychrophilic and psychrotolerant microorganisms, which inhabit all of the cold environments on Earth have important applications to Bioremediation, Medicine, Pharmaceuticals, and many other areas of Biotechnology. Until recently, most of the research on polar microorganisms was confined to studies of polar diatoms, yeast, fungi and cyanobacteria. However, within the past three decades, extensive studies have been conducted to understand the bacteria and archaea that inhabit the Arctic and Antarctic sea-ice, glaciers, ice sheets, permafrost and the cryptoendolithic, cryoconite and ice-bubble environments. These investigations have resulted in the discovery of many new genera and species of anaerobic and aerobic microbial extremophiles. Exotic enzymes, cold-shock proteins and pigments produced by some of the extremophiles from polar environments have the potential to be of great benefit to Mankind. Knowledge about microbial life in the polar regions is crucial to understanding the limitations and biodiversity of life on Earth and may provide valuable clues to the Origin of Life on Earth. The discovery of viable microorganisms in ancient ice from the Fox Tunnel, Alaska and the deep Vostok Ice has shown that microorganisms can remain alive while cryopreserved in ancient ice. The psychrophilic lithoautotrophic homoacetogen isolated from the deep anoxic trough of Lake Untersee is an ideal candidate for life that might inhabit comets or the polar caps of Mars. The spontaneous release of gas from within the Anuchin Glacier above Lake Untersee may provide clues to the ice geysers that erupt from the tiger stripe regions of Saturn s moon Enceladus. The methane productivity in the lower regimes of Lake Untersee may also provide insights into possible mechanisms for the recently discovered methane releases on Mars. Since most of the other water bearing bodies of our

  15. Polarized vacuum ultraviolet and X-radiation

    International Nuclear Information System (INIS)

    Samson, J.A.R.

    1978-01-01

    The most intense source of polarized vacuum UV and X-radiation is synchrotron radiation, which exhibits a degree of partially polarized light between about 80-100%. However, the radiation transmitted by vacuum UV monochromators can also be highly polarized. The Seya-Namioka type of monochromator can produce partially polarized radiation between 50-80%. For certain experiments it is necessary to know the degree of polarisation of the radiation being used. Also, when synchrotron radiation and a monochromator are combined the polarization characteristic of both should be known in order to make full use of these polarization properties. The polarizing effect on monochromators (i.e. diffraction gratings) have been measured at the Seya angle and at grazing angles for various spectral orders. The author presents the first experimental evidence that the reciprocity law holds for polarization by reflection where the angle of incidence and diffraction are unequal. These results are reviewed along with the techniques for measuring the degree of polarization. (Auth.)

  16. Topological induced valley polarization in bilayer graphene/Boron Nitride

    Science.gov (United States)

    Basile, Leonardo; Idrobo, Juan C.

    2015-03-01

    Novel electronic devices relay in our ability to control internal quantum degrees of freedom of the electron e.g., its spin. The valley number degree of freedom is a pseudospin that labels degenerate eigenstates at local maximum/minimum on the valence/conduction band. Valley polarization, that is, selective electronic localization in a momentum valley and its manipulation can be achieved by means of circular polarized light (CPL) in a system with strong spin-orbit coupling (SOC). In this talk, we will show theoretically that despite the fact that neither graphene or BN have a strong SOC, a bilayer of graphene on BN oriented at a twist angle has different absorption for right- and left- CPL. This induced polarization occurs due to band folding of the electronic bands, i.e., it has a topological origin. This research was supported EPN multidisciplinary grant and by DOE SUFD MSED.

  17. Spin-polarized photoemission

    International Nuclear Information System (INIS)

    Johnson, Peter D.

    1997-01-01

    Spin-polarized photoemission has developed into a versatile tool for the study of surface and thin film magnetism. In this review, we examine the methodology of the technique and its application to a number of different problems, including both valence band and core level studies. After a detailed review of spin-polarization measurement techniques and the related experimental requirements we consider in detail studies of the bulk properties both above and below the Curie temperature. This section also includes a discussion of observations relating to unique metastable phases obtained via epitaxial growth. The application of the technique to the study of surfaces, both clean and adsorbate covered, is reviewed. The report then examines, in detail, studies of the spin-polarized electronic structure of thin films and the related interfacial magnetism. Finally, observations of spin-polarized quantum well states in non-magnetic thin films are discussed with particular reference to their mediation of the oscillatory exchange coupling in related magnetic multilayers. (author)

  18. A review of polarized ion sources

    International Nuclear Information System (INIS)

    Schmor, P.W.

    1995-06-01

    The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

  19. Polarization phenomena in heavy-ion reactions

    International Nuclear Information System (INIS)

    Sugimoto, K.; Ishihara, M.; Takahashi, N.

    1984-01-01

    This chapter presents a few key experiments which provide direct evidence of the polarization phenomena in heavy-ion reactions. The theory of polarization observables and measurements is given with the necessary formulae. The polarization phenomena is described and studies of product nuclear polarization in heavy-ion reactions are discussed. Studies of heavy-ion reactions induced by polarized beams are examined

  20. Polarimetry of the polarized hydrogen deuteride HDice target under an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Laine, Vivien E. [Blaise Pascal Univ., Aubiere (France)

    2013-10-01

    The study of the nucleon structure has been a major research focus in fundamental physics in the past decades and still is the main research line of the Thomas Jefferson National Accelerator Facility (Jefferson Lab). For this purpose and to obtain statistically meaningful results, having both a polarized beam and a highly efficient polarized target is essential. For the target, this means high polarization and high relative density of polarized material. A Hydrogen Deuteride (HD) target that presents both such characteristics has been developed first at Brookhaven National Lab (BNL) and brought to the Hall B of Jefferson Lab in 2008. The HD target has been shown to work successfully under a high intensity photon beam (BNL and Jefferson Lab). However, it remained to be seen if the target could stand an electron beam of reasonably high current (nA). In this perspective, the target was tested for the first time in its frozen spin mode under an electron beam at Jefferson Lab in 2012 during the g14 experiment. This dissertation presents the principles and usage procedures of this HD target. The polarimetry of this target with Nuclear Magnetic Resonance (NMR) during the electron beam tests is also discussed. In addition, this dissertation also describes another way to perform target polarimetry with the elastic scattering of electrons off a polarized target by using data taken on helium-3 during the E97-110 experiment that occurred in Jefferson Lab's Hall A in 2003.

  1. Dynamic nuclear polarization tests in some polymers for polarized targets

    International Nuclear Information System (INIS)

    Brandt, B. van den; Hautle, P.; Konter, J.A.; Mango, S.; Bunyatova, E.I.

    1998-01-01

    The results of dynamic polarization tests in polyethylene (PE) and ethylene propylene copolymer (EPC), doped with the stable free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), are presented. Sizable proton polarizations have been achieved in a magnetic field of 2.5 T at a temperature below 0.3 K and 5T at 1 K

  2. Fluvial geomorphology and aquatic-to-terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

    Science.gov (United States)

    Sullivan, S. Mažeika P.; Boaz, Lindsey E.; Hossler, Katie

    2016-04-01

    Although mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic-to-terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic-to-terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller-bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic-to-terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

  3. 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

  4. Do embryonic polar bodies commit suicide?

    Science.gov (United States)

    Fabian, Dušan; Čikoš, Štefan; Rehák, Pavol; Koppel, Juraj

    2014-02-01

    The extrusion and elimination of unnecessary gametic/embryonic material is one of the key events that determines the success of further development in all living organisms. Oocytes produce the first polar body to fulfill the maturation process just before ovulation, and release the second polar body immediately after fertilization. The aim of this study was to compile a physiological overview of elimination of polar bodies during early preimplantation development in mice. Our results show that three-quarters of the first polar bodies were lost even at the zygotic stage; the 4-cell stage embryos contained only one (second) polar body, and the elimination of second polar bodies proceeded continuously during later development. Both first and second polar bodies showed several typical features of apoptosis: phosphatidylserine redistribution (observed for the first time in the first polar body), specific DNA degradation, condensed nuclear morphology, and inability to exclude cationic dye from the nucleus during the terminal stage of the apoptotic process. Caspase-3 activity was recorded only in the second polar body. From the morphological point of view, mouse polar bodies acted very similarly to damaged embryonic cells which have lost contact with their neighboring blastomeres. In conclusion, polar bodies possess all the molecular equipment necessary for triggering and executing an active suicide process. Furthermore, similarly as in dying embryonic cells, stressing external conditions (culture in vitro) might accelerate and increase the incidence of apoptotic elimination of the polar bodies in embryos.

  5. Spin exchange in polarized deuterium

    International Nuclear Information System (INIS)

    Przewoski, B. von; Meyer, H.O.; Balewski, J.; Doskow, J.; Ibald, R.; Pollock, R.E.; Rinckel, T.; Wellinghausen, A.; Whitaker, T.J.; Daehnick, W.W.; Haeberli, W.; Schwartz, B.; Wise, T.; Lorentz, B.; Rathmann, F.; Pancella, P.V.; Saha, Swapan K.; Thoerngren-Engblom, P.

    2003-01-01

    We have measured the vector and tensor polarization of an atomic deuterium target as a function of the target density. The polarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam source was operated without rf transitions, in order to avoid complications from the unknown efficiency of these transitions. In this mode, the atomic beam is vector and tensor polarized and both polarizations can be measured simultaneously. We used a 1.2-cm-diam and 27-cm-long storage cell, which yielded an average target density between 3 and 9x10 11 at/cm 3 . We find that the tensor polarization decreases with increasing target density while the vector polarization remains constant. The data are in quantitative agreement with the calculated effect of spin exchange between deuterium atoms at low field

  6. Study by polarized muon

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu

    1977-01-01

    Experiments by using polarized muon beam are reported. The experiments were performed at Berkeley, U.S.A., and at Vancouver, Canada. The muon spin rotation is a useful method for the study of the spin polarization of conductive electrons in paramagnetic Pd metal. The muon Larmor frequency and the relaxation time can be obtained by measuring the time distribution of decay electrons of muon-electron process. The anomalous depolarization of negative muon spin rotation in the transitional metal was seen. The circular polarization of the negative muon X-ray was measured to make clear this phenomena. The experimental results show that the anomalous depolarization is caused at the 1-S-1/2 state. For the purpose to obtain the strong polarization of negative muon, a method of artificial polarization is proposed, and the test experiments are in progress. The study of the hyperfine structure of mu-mesic atoms is proposed. The muon capture rate was studied systematically. (Kato, T.)

  7. ACCELERATION OF POLARIZED PROTONS AT RHIC

    International Nuclear Information System (INIS)

    HUANG, H.

    2002-01-01

    Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined

  8. Polarization experiments with hadronic and electromagnetic probes

    International Nuclear Information System (INIS)

    Punjabi, V.

    1993-01-01

    The following research activities were carried out during the past year Calibration of focal plane polarimeter POMME up to 2.4 GeV at Saturne National Laboratory (LNS) in Saclay. Measurement of tensor analyzing power T 20 and polarization transfer κ 0 at Saturne up to 2.1 GeV in elastic backward dp scattering rvec dp → rvec pd. Measurement of tensor analyzing power T 20 at synchrophasotron in Dubha up to 4.4 Gev in elastic backward dp scattering rvec dp → pd. Resubmission of conditionally Approved G EP proposal 89-14 at CEBAF. Start construction of focal plane polarimeter (FPP) for CEBAF hall A hadron spectrometer. The planned work for the next year includes: Construction of FPP for CEBAF hall A hadron spectrometer; measurement of polarization transfer κ 0 and tensor analyzing power T 20 in elastic backward dp scattering at Saturne; measurements of tensor analyzing power in 1 H( 6 Li,d)X, 1 H( 6 Li,α)X, 1 H( 6 Li,t)X and 1 H( 6 Li, 3 He)X reactions at Saturne; and study of polarization transfer in 2 H(rvec e,e'rvec p)n reaction at Bates

  9. Polarized deuteron elastic scattering from a polarized proton target

    Energy Technology Data Exchange (ETDEWEB)

    Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Physikalisches Inst.); Zankel, H. (Graz Univ. (Austria). Inst. fuer Theoretische Physik)

    1983-01-13

    Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76/sup 0/,85/sup 0/,98/sup 0/,115/sup 0/,132/sup 0/). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results.

  10. The Polarization of Achernar

    Science.gov (United States)

    McDavid, D.

    2005-11-01

    Recent near-infrared measurements of the angular diameter of Achernar (the bright Be star alpha Eridani) with the ESO VLT interferometer have been interpreted as the detection of an extremely oblate photosphere, with a ratio of equatorial to polar radius of at least 1.56 ± 0.05 and a minor axis orientation of 39° ± 1° (from North to East). The optical linear polarization of this star during an emission phase in 1995 September was 0.12 ± 0.02% at position angle 37° ± 8° (in equatorial coordinates), which is the direction of the projection of the rotation axis on the plane of the sky according to the theory of polarization by electron scattering in an equatorially flattened circumstellar disk. These two independent determinations of the orientation of the rotation axis are therefore in agreement. The observational history of correlations between Hα emission and polarization as found in the literature is that of a typical Be star, with the exception of an interesting question raised by the contrast between Schröder's measurement of a small polarization perpendicular to the projected rotation axis in 1969--70 and Tinbergen's measurement of zero polarization in 1974.5, both at times when emission was reportedly absent.

  11. Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide

    Science.gov (United States)

    Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei

    2018-02-01

    CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.

  12. Optically pumped electron spin polarized targets for use in the production of polarized ion beams

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1979-01-01

    The production of relatively dense electron spin polarized alkali metal vapor targets by optical pumping with intense cw dye lasers is discussed. The target density and electron spin polarization depend on the dye laser intensity and bandwidth, the magnetic field at the target, and the electron spin depolarization time. For example in a magnetic field of 1.5 x 10 3 G, and using 1 W dye laser with a bandwidth of 10 10 Hz one can construct an electron spin polarized Na vapor target with a target thickness of 1.6 x 10 13 atoms/cm 2 and an average electron spin polarization of about 90% even though the Na atoms are completely depolarized at every wall collision. Possible uses of the electron spin polarized targets for the production of intense beams of polarized H - or 3 He - ions are discussed. (orig.)

  13. Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

    International Nuclear Information System (INIS)

    Green, M.C.

    1984-01-01

    A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target

  14. Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

    International Nuclear Information System (INIS)

    Green, M.C.

    1984-05-01

    A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target. 15 references, 10 figures

  15. Sources of linear polarized x-rays

    International Nuclear Information System (INIS)

    Aiginger, H.; Wobrauschek, P.

    1989-01-01

    Linear polarized X-rays are used in X-ray fluorescence analysis to decrease the background caused by scattered photons. Various experiments, calculations and constructions have demonstrated the possibility to produce polarized radiation in an analytical laboratory with an X-ray tube and polarizer-analyzer facilities as auxiliary equipment. The results obtained with Bragg-polarizers of flat and curved focussing geometry and of Barkla-polarizers are presented. The advantages and disadvantages of the method are discussed and compared with the respective quality of synchrotron radiation. Polarization by scattering reduces the intensity of the primary radiation. Recently much effort is devoted to the construction of integrated high power X-ray tube polarizer-analyzer arrangements. The detailed design, geometry and performance of such a facility is described. (author)

  16. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-01-01

    As a distinct field, elementary particle physics is now approximately forty years old. In all that time, only a few of the thousands of experiments that have been performed have made use of spin polarized particle beams (with apologies to those who have studied neutrino interactions, polarized beam are defined to refer to the case in which the experimenter has control over the polarization direction). If the discussion is restricted to spin polarized electron beams, the number of experiments becomes countable with the fingers of one hand (with several to spare). There are two reasons for this lack of interest. The first is that spin polarized beams are difficult to produce, accelerate, and transport. The second reason is that any physical process that can occur during the collision of a polarized particle with another (polarized or not) can also occur during the collision of unpolarized particles. One might ask then, why has any effort been expended on the subject. The answer, at least in the case of polarized electron beams, is that electron accelerators and storage rings have in recent years achieved sufficient energy to begin to probe the weak interaction directly. The weak interaction distinguishes between left- and right-handed fermionic currents. Left-handed particles interact in a fundamentally different way than their right-handed counterparts. If the experimenter wishes to explore or exploit this difference, he (or she) must either prepare the spin state of the incident particles or analyze the spin state of outgoing particles. For reasons of genearlity and improved statistical precision, the former is usually preferable to the latter. The first of these lectures will review some of the techniques necessary for the production, transport, and monitoring of polarized electron (or positron) beams. The second lecture will survey some of the physics possibilities of polarized electron-positron collisions

  17. Multiphoton polarization Bremsstrahlung effect

    International Nuclear Information System (INIS)

    Golovinskij, P.A.

    2001-01-01

    A general approach to induced polarization effects was formulated on the basis of theory of many particles in a strong periodic field. Correlation with the perturbation theory is shown and the types of effective polarization potentials both for isolated atoms and ions, and for ions in plasma, are provided. State of art in the theory of forced polarization Bremsstrahlung effect is analyzed and some outlooks for further experimental and theoretical studies are outlined [ru

  18. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  19. Effects of polarization-charge shielding in microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M. S.; Lin, S. M.; Chiang, W. Y.; Barnett, L. R.; Chu, K. R., E-mail: krchu@yahoo.com.tw [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

    2015-08-15

    Heating of dielectric objects by radio frequency (RF) and microwaves has long been a method widely employed in scientific research and industrial applications. However, RF and microwave heating are often susceptible to an excessive temperature spread due to uneven energy deposition. The current study elucidates an important physical reason for this difficulty and proposes an effective remedy. Non-spherical samples are placed in an anechoic chamber, where it is irradiated by a traveling microwave wave with 99% intensity uniformity. Polarization charges induced on the samples tend to partially cancel the incident electric field and hence reduce the heating rate. The polarization-charge shielded heating rate is shown to be highly dependent on the sample's shape and its orientation relative to the wave electric field. For samples with a relatively high permittivity, the resultant uneven heating can become a major cause for the excessive temperature spread. It is also demonstrated that a circularly polarized wave, with its rapidly rotating electric field, can effectively even out the heating rate and hence the temperature spread.

  20. 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.

  1. Polarized radio outbursts in BL Lacertae. I. Polarized emission from a compact jet. II. The flux and polarization of a piston-driven shock

    International Nuclear Information System (INIS)

    Aller, H.D.; Aller, M.F.; Hughes, P.A.

    1985-01-01

    A second highly polarized burst in BL Lacertae observed in 1983 which has very similar properties to the earlier burst in 1981-82 is described, and it is shown that in both bursts the electric vector of the polarized emission is nearly parallel to the observed extended structure. A weak shock, moving relativistically close to the line of sight, appears to be a very effective means of producing the observed behavior. A simple model is developed to represent the outbursts as due to a piston-driven shock which exhibits polarized emission due to compression of the otherwise random magnetic field of a collimated flow. It is shown that the general features of total flux, polarized flux, and polarization position angle as a function of frequency and time can be understood in terms of such a model. 34 references

  2. Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sen; Zhang, Yan, E-mail: yzhang@mail.cnu.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Wang, Xinke [Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Kan, Qiang [State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Qu, Shiliang [Optoelectronics Department, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2015-12-14

    A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology.

  3. Optically Polarized Conduction-Band Electrons in Tungsten Observed by Spin-Polarized Photoemission

    DEFF Research Database (Denmark)

    Zürcher, P.; Meier, F.; Christensen, N. E.

    1979-01-01

    Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV......Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV...

  4. Observation of interface dependent spin polarized photocurrents in InAs/GaSb superlattice

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan, E-mail: liyuan12@semi.ac.cn; Liu, Yu; Zhu, Laipan; Qin, Xudong; Wu, Qing; Huang, Wei; Chen, Yonghai, E-mail: yhchen@semi.ac.cn [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing (China); Niu, Zhichuan; Xiang, Wei; Hao, Hongyue [The State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing (China)

    2015-05-11

    In this letter, we investigated the spin polarized photocurrents excited by mid-infrared radiation and near-infrared radiation, respectively, in InAs/GaSb type II superlattices with different kinds of interfaces. By periodically varying the polarization state of the radiation, we analyzed Rashba-type and Dresselhaus-type spin polarized photocurrents, which present different features depending on the interface types and excitation conditions. Under mid-infrared excitation, the ratio of Rashba-type and Dresselhaus-type spin polarized photocurrents of the superlattice with InSb-like interface is obviously larger than that of the superlattice with GaAs-like interface, the ratio of the superlattice with alternate interface is in the middle. Whereas under near-infrared excitation, the ratios of the three superlattices are nearly the same. Further researches reveal the synactic effects of interface dependent strain and asymmetric interface potential on the spin splitting. Besides, the polarized Raman spectroscopies of these structures were also analyzed.

  5. Observation of interface dependent spin polarized photocurrents in InAs/GaSb superlattice

    International Nuclear Information System (INIS)

    Li, Yuan; Liu, Yu; Zhu, Laipan; Qin, Xudong; Wu, Qing; Huang, Wei; Chen, Yonghai; Niu, Zhichuan; Xiang, Wei; Hao, Hongyue

    2015-01-01

    In this letter, we investigated the spin polarized photocurrents excited by mid-infrared radiation and near-infrared radiation, respectively, in InAs/GaSb type II superlattices with different kinds of interfaces. By periodically varying the polarization state of the radiation, we analyzed Rashba-type and Dresselhaus-type spin polarized photocurrents, which present different features depending on the interface types and excitation conditions. Under mid-infrared excitation, the ratio of Rashba-type and Dresselhaus-type spin polarized photocurrents of the superlattice with InSb-like interface is obviously larger than that of the superlattice with GaAs-like interface, the ratio of the superlattice with alternate interface is in the middle. Whereas under near-infrared excitation, the ratios of the three superlattices are nearly the same. Further researches reveal the synactic effects of interface dependent strain and asymmetric interface potential on the spin splitting. Besides, the polarized Raman spectroscopies of these structures were also analyzed

  6. 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).

  7. 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).

  8. Rhizoids and protonemata of characean algae: model cells for research on polarized growth and plant gravity sensing.

    Science.gov (United States)

    Braun, M; Limbach, C

    2006-12-01

    Gravitropically tip-growing rhizoids and protonemata of characean algae are well-established unicellular plant model systems for research on gravitropism. In recent years, considerable progress has been made in the understanding of the cellular and molecular mechanisms underlying gravity sensing and gravity-oriented growth. While in higher-plant statocytes the role of cytoskeletal elements, especially the actin cytoskeleton, in the mechanisms of gravity sensing is still enigmatic, there is clear evidence that in the characean cells actin is intimately involved in polarized growth, gravity sensing, and the gravitropic response mechanisms. The multiple functions of actin are orchestrated by a variety of actin-binding proteins which control actin polymerisation, regulate the dynamic remodelling of the actin filament architecture, and mediate the transport of vesicles and organelles. Actin and a steep gradient of cytoplasmic free calcium are crucial components of a feedback mechanism that controls polarized growth. Experiments performed in microgravity provided evidence that actomyosin is a key player for gravity sensing: it coordinates the position of statoliths and, upon a change in the cell's orientation, directs sedimenting statoliths to specific areas of the plasma membrane, where contact with membrane-bound gravisensor molecules elicits short gravitropic pathways. In rhizoids, gravitropic signalling leads to a local reduction of cytoplasmic free calcium and results in differential growth of the opposite subapical cell flanks. The negative gravitropic response of protonemata involves actin-dependent relocation of the calcium gradient and displacement of the centre of maximal growth towards the upper flank. On the basis of the results obtained from the gravitropic model cells, a similar fine-tuning function of the actomyosin system is discussed for the early steps of gravity sensing in higher-plant statocytes.

  9. Polarization and ellipticity of high-order harmonics from aligned molecules generated by linearly polarized intense laser pulses

    International Nuclear Information System (INIS)

    Le, Anh-Thu; Lin, C. D.; Lucchese, R. R.

    2010-01-01

    We present theoretical calculations for polarization and ellipticity of high-order harmonics from aligned N 2 , CO 2 , and O 2 molecules generated by linearly polarized lasers. Within the rescattering model, the two polarization amplitudes of the harmonics are determined by the photo-recombination amplitudes for photons emitted with polarization parallel or perpendicular to the direction of the same returning electron wave packet. Our results show clear species-dependent polarization states, in excellent agreement with experiments. We further note that the measured polarization ellipse of the harmonic furnishes the needed parameters for a 'complete' experiment in molecules.

  10. Multiband Circular Polarizer Based on Fission Transmission of Linearly Polarized Wave for X-Band Applications

    Directory of Open Access Journals (Sweden)

    Farman Ali Mangi

    2016-01-01

    Full Text Available A multiband circular polarizer based on fission transmission of linearly polarized wave for x-band application is proposed, which is constructed of 2 × 2 metallic strips array. The linear-to-circular polarization conversion is obtained by decomposing the linearly incident x-polarized wave into two orthogonal vector components of equal amplitude and 90° phase difference between them. The innovative approach of “fission transmission of linear-to-circular polarized wave” is firstly introduced to obtain giant circular dichroism based on decomposition of orthogonal vector components through the structure. It means that the incident linearly polarized wave is converted into two orthogonal components through lower printed metallic strips layer and two transmitted waves impinge on the upper printed strips layer to convert into four orthogonal vector components at the end of structure. This projection and transmission sequence of orthogonal components sustain the chain transmission of electromagnetic wave and can achieve giant circular dichroism. Theoretical analysis and microwave experiments are presented to validate the performance of the structure. The measured results are in good agreement with simulation results. In addition, the proposed circular polarizer exhibits the optimal performance with respect to the normal incidence. The right handed circularly polarized wave is emitted ranging from 10.08 GHz to 10.53 GHz and 10.78 GHz to 11.12 GHz, while the left handed circular polarized wave is excited at 10.54 GHz–10.70 GHz and 11.13 GHz–11.14 GHz, respectively.

  11. 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.

  12. Polarized semi-inclusive deep-inelastic scattering on transversely and longitudinally polarized nucleons at HERMES

    International Nuclear Information System (INIS)

    Hommes, B.

    2005-01-01

    The HERMES experiment has measured double spin asymmetries in the cross section for deep-inelastic scattering of longitudinal polarized positrons off longitudinal polarized hydrogen and deuterium targets. From these asymmetries, based on inclusive and semi-inclusive measurements, polarized quark distributions were extracted as a function of x. Single-spin azimuthal asymmetries in semi-inclusive pion production were measured by the HERMES experiment for the first time, with a transversely polarized hydrogen target. Two different sine-dependencies were extracted which can be related to the quark transversity distribution h q 1 (x) and the Sivers function (Author)

  13. Polarized X-Ray Emission from Magnetized Neutron Stars: Signature of Strong-Field Vacuum Polarization

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C.

    2003-08-01

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  14. Optimization of incident EC wave polarization in real-time polarization scan experiments on LHD

    International Nuclear Information System (INIS)

    Tsujimura, Toru I.; Mizuno, Yoshinori; Makino, Ryohei

    2016-01-01

    Real-time polarization scan experiments were performed on the Large Helical Device (LHD) to search an optimal incident wave polarization for electron cyclotron resonance heating. The obtained optimal polarization state to maximize the power absorption to the LHD plasma is compared with the ray-tracing code that includes mode content analyses, which indicates that the calculated results are generally in good agreement with the experimental results. The analyses show that optimal coupling to plasma waves requires a fine adjustment for an incident wave polarization even for perpendicular injection due to the finite density profile and the magnetic shear at the peripheral region. (author)

  15. Polarized x-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization.

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C G

    2003-08-15

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  16. Spin-polarized tunneling through a ferromagnetic insulator

    NARCIS (Netherlands)

    Kok, M.; Kok, M.; Beukers, J.N.; Brinkman, Alexander

    2009-01-01

    The polarization of the tunnel conductance of spin-selective ferromagnetic insulators is modeled, providing a generalized concept of polarization including both the effects of electrode and barrier polarization. The polarization model is extended to take additional non-spin-polarizing insulating

  17. Constraining Polarized Foregrounds for EoR Experiments. II. Polarization Leakage Simulations in the Avoidance Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Nunhokee, C. D.; Bernardi, G.; Foster, G.; Grobler, T. L. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown, 6140 (South Africa); Kohn, S. A.; Aguirre, J. E.; Martinot, J. Z. E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Thyagarajan, N. [Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287 (United States); Dillon, J. S. [Berkeley Center for Cosmological Physics, Berkeley, CA 94720 (United States); Parsons, A. R., E-mail: cnunhokee@gmail.com [Dept. of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2017-10-10

    A critical challenge in the observation of the redshifted 21 cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc{sup −1} can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.

  18. Polarization-dependent optics using gauge-field metamaterials

    International Nuclear Information System (INIS)

    Liu, Fu; Xiao, Shiyi; Li, Jensen; Wang, Saisai; Hang, Zhi Hong

    2015-01-01

    We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework

  19. The Bochum Polarized Target

    International Nuclear Information System (INIS)

    Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

    2001-01-01

    The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

  20. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  1. Measuring fluorescence polarization with a dichrometer.

    Science.gov (United States)

    Sutherland, John C

    2017-09-01

    A method for obtaining fluorescence polarization data from an instrument designed to measure circular and linear dichroism is compared with a previously reported approach. The new method places a polarizer between the sample and a detector mounted perpendicular to the direction of the incident beam and results in determination of the fluorescence polarization ratio, whereas the previous method does not use a polarizer and yields the fluorescence anisotropy. A similar analysis with the detector located axially with the excitation beam demonstrates that there is no frequency modulated signal due to fluorescence polarization in the absence of a polarizer. Copyright © 2017. Published by Elsevier Inc.

  2. Microwave-gated dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Bornet, Aurélien; Pinon, Arthur; Jhajharia, Aditya

    2016-01-01

    Dissolution dynamic nuclear polarization (D-DNP) has become a method of choice to enhance signals in nuclear magnetic resonance (NMR). Recently, we have proposed to combine cross-polarization (CP) with D-DNP to provide high polarization P((13)C) in short build-up times. In this paper, we show...

  3. 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

  4. Polarization Effects at a Muon Collider

    International Nuclear Information System (INIS)

    Parsa, Z.

    1998-01-01

    For Muon Colliders, Polarization will be a useful tool if high polarization is achievable with little luminosity loss. Formulation and effects of beam polarization and luminosity including polarization effects in Higgs resonance studies are discussed for improving precision measurements and Higgs resonance ''discovery'' capability e.g. at the First Muon Collider (FMC)

  5. Neutron polarization measurements using the pulsed-polarized proton and deuteron beams at TUNL

    International Nuclear Information System (INIS)

    Walter, R.L.

    1981-01-01

    Nanosecond wide pulses of polarized protons or deuterons at a repetition rate of 4 MHz are now routinely available for studying interactions involving outgoing neutrons. Up to 90 nA of protons and 200 nA of deuterons have been observed on target. The authors' first experiments involved the determination of the analyzing power A /SUB y/ (UJ) for a few (→p,n) and (→d,n) reactions using conventional neutron time-of-flight detection. A major program for observing polarization effects in neutron elastic scattering has been initiated. The source of polarized neutrons for this program is the 2 H(→d,n→) 3 He reaction which yields a neutron beam having 90% of the polarization of the incident deuterons

  6. Ultra-thin, single-layer polarization rotator

    Directory of Open Access Journals (Sweden)

    T. V. Son

    2016-08-01

    Full Text Available We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal. Changes in refractive indices create unequal phase shifts on s- and p-polarization components of incident light, and rotation of linear polarization shows intensity modulation by a factor of 103 when transmitted through polarizers. This makes possible polarization rotation devices as thin as 50 nm that would be activated thermally, optically or electrically.

  7. 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

  8. Eddy intrusion of hot plasma into the polar cap and formation of polar-cap arcs

    International Nuclear Information System (INIS)

    Chiu, Y.T.; Gorney, D.J.

    1983-01-01

    We present plasma and electric field data obtained by the S3-3 satellite over the polar caps. We demonstrate that: (1) plasma signatures in the polar cap arc formation region near 5000 km altitude show clear intrusions of plasma sheet (approx.keV) and magneto sheath (approx.100 eV) plasma into a background of low-energy polar cap plasma; (2) the combined plasma and electric field signatures (electron inverted-V, ion beam and delxE<0) are exactly the same as in the evening discrete arc. We interpret this equivalence of polar cap and evening discrete arc signatures as indication that their formation processes are identical. The spatial structures of polar cap electric fields and the associated plasma signatures are consistent with the hypothesis that plasma intrusion into the polar cap takes the form of multiple cellular eddies. This hypothesis provides a unifying view of arc formation and arc configurations

  9. 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.

  10. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  11. Spin polarization and magnetic effects in radical reactions

    International Nuclear Information System (INIS)

    Salikhov, K.M.; Molin, Yu.N.; Sagdeev, R.Z.; Buchachenko, A.L.

    1984-01-01

    Studies on the effects of chemically induced dynamic nuclear and electron polarizations (CIDNP and CIDEP), and magnetic effects in radical reactions, have given rise to a new rapidly-progressing field of chemical physics. It came into being about ten years ago and has been attracting the ever-growing attention of researchers in related areas. The present book is a fairly all-embracing review of the state of affairs in this field. The book presents the physical background (both theoretical and experimental) of CIDNP and CIDEP, of the effects of an external magnetic field and magnetic nuclear moment (magnetic isotope effects) on radical reactions in solutions. Great attention has been paid to the application of chemical spin polarization and magnetic effects to solving various problems of chemical kinetics, structural chemistry, molecular physics, magnetobiology, and radiospectroscopy. The book will be useful for physicists, chemists and biologists employing CIDNP, CIDEP and magnetic effects in their investigations, as well as for researchers in related fields of chemical physics. The book can be also recommended for postgraduates and senior undergraduate students. (Auth.)

  12. Polarized epithermal neutron spectrometer at KENS

    International Nuclear Information System (INIS)

    Kohgi, M.

    1983-01-01

    A spectrometer employing a white, epithermal, polarized neutron beam is under construction at KENS. The neutron polarization is achieved by passage through a dynamically polarized proton filter (DPPF). The results of the test experiments show that the DPPF method is promising in obtaining polarized epithermal neutron beam. The basic design of the spectrometer is described

  13. The polarized neutron reflectometer 'Reverans'

    Energy Technology Data Exchange (ETDEWEB)

    Radzhabov, A.K. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation)]. E-mail: akr@pnpi.spb.ru; Gordeev, G.P. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Lazebnik, I.M. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Axelrod, L.A. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Zabenkin, V.N. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation)

    2007-07-15

    The polarized neutron reflectometer 'Reverans' with a vertical plane of scattering is being installed at the VVR-M reactor (Gatchina, Russia). It will be used for research on phase boundaries, interfaces and free surfaces. Systems under study can be both magnetic and nonmagnetic ones. At present the installation of the reflectometer is at the final stage. The parameters and abilities of the reflectometer are presented.

  14. Field data collection, analysis, and adaptive management of green infrastructure in the urban water cycle in Cleveland and Columbus, OH

    Science.gov (United States)

    Darner, R.; Shuster, W.

    2016-12-01

    Expansion of the urban environment can alter the landscape and creates challenges for how cities deal with energy and water. Large volumes of stormwater in areas that have combined septic and stormwater systems present on challenge. Managing the water as near to the source as possible by creates an environment that allows more infiltration and evapotranspiration. Stormwater control measures (SCM) associated with this type of development, often called green infrastructure, include rain gardens, pervious or porous pavements, bioswales, green or blue roofs, and others. In this presentation, we examine the hydrology of green infrastructure in urban sewersheds in Cleveland and Columbus, OH. We present the need for data throughout the water cycle and challenges to collecting field data at a small scale (single rain garden instrumented to measure inflows, outflow, weather, soil moisture, and groundwater levels) and at a macro scale (a project including low-cost rain gardens, highly engineered rain gardens, groundwater wells, weather stations, soil moisture, and combined sewer flow monitoring). Results will include quantifying the effectiveness of SCMs in intercepting stormwater for different precipitation event sizes. Small scale deployment analysis will demonstrate the role of active adaptive management in the ongoing optimization over multiple years of data collection.

  15. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H B [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  16. Observing the Cosmic Microwave Background Polarization with Variable-delay Polarization Modulators for the Cosmology Large Angular Scale Surveyor

    Science.gov (United States)

    Harrington, Kathleen; CLASS Collaboration

    2018-01-01

    The search for inflationary primordial gravitational waves and the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background (CMB), has created the need for high sensitivity measurements of polarization across large fractions of the sky at millimeter wavelengths. These measurements are subjected to instrumental and atmospheric 1/f noise, which has motivated the development of polarization modulators to facilitate the rejection of these large systematic effects.Variable-delay polarization modulators (VPMs) are used in the Cosmology Large Angular Scale Surveyor (CLASS) telescopes as the first element in the optical chain to rapidly modulate the incoming polarization. VPMs consist of a linearly polarizing wire grid in front of a moveable flat mirror; varying the distance between the grid and the mirror produces a changing phase shift between polarization states parallel and perpendicular to the grid which modulates Stokes U (linear polarization at 45°) and Stokes V (circular polarization). The reflective and scalable nature of the VPM enables its placement as the first optical element in a reflecting telescope. This simultaneously allows a lock-in style polarization measurement and the separation of sky polarization from any instrumental polarization farther along in the optical chain.The Q-Band CLASS VPM was the first VPM to begin observing the CMB full time in 2016. I will be presenting its design and characterization as well as demonstrating how modulating polarization significantly rejects atmospheric and instrumental long time scale noise.

  17. 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

    VE Science Definition Team and Project Office. See: http://above.nasa.gov - UNAVCO Terrestrial Laser Scanning (TLS): UNAVCO's Polar program provides support for terrestrial laser scanning field projects. We are using RAMADDA to archive these field projects, with over 40 projects ingested to date. - NASA-IceBridge: As part of the NASA LiDAR Access System (NLAS) project, RAMADDA supports numerous airborne and satellite LiDAR data sets - GLAS, LVIS, ATM, Paris, McORDS, etc. - Antarctic Meteorological Research Center (AMRC): Satellite and surface observation network - Support for numerous other data from AON-ACADIS, Greenland GC-Net, NOAA-GMD, AmeriFlux, etc. In this talk we will discuss some of the challenges that Polar data brings to geoinformatics and describe the approaches we have taken to address these challenges in RAMADDA.

  18. Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes

    Science.gov (United States)

    Zakerhamidi, M. S.; Golghasemi Sorkhabi, Sh.; Shamkhali, A. N.

    2014-06-01

    Absorption and fluorescence spectra of three Sudan dyes (SudanIII, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800 nm, at room temperature. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. Furthermore, analyze of solvent-solute interactions and value of ground and excited states dipole moments suggests different forms of resonance structures for Sudan dyes in polar and low-polar solvents.

  19. 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

  20. 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.

  1. Dynamic polarization of radioactive nuclei

    International Nuclear Information System (INIS)

    Kiselev, Yu.F.; Lyuboshits, V.L.; )

    2001-01-01

    Radioactive nuclei, embedded into a frozen polarized proton target, atr proposed to polarize by means of some dynamic polarization methods. Angular distributions of γ-quanta emitted ny 22 Na(3 + ) in the cascade β-γ-radiation are calculated. It is shown that this distribution does not depend on the spin temperature sing at the Boltzmann distribution of populations among the Zeeman magnetic substates, whereas the tensor polarization of quadrupole nuclei, placed in the electric field of the crystal, causes the considerable sing dependence. The new method promises wide opportunities for the magnetic structure investigations as well as for the study of spin-spin interaction dynamics of rare nuclei in dielectrics. Physical-technical advantages and disadvantages of the given method are discussed for the polarization of heavy nuclei in the on-line implantation mode [ru

  2. Latest polarization and beam characterization results of the Orsay polarized electron source

    International Nuclear Information System (INIS)

    Arianer, J.; Cohen, S.; Essabaa, S.; Frascaria, R.; Zerhouni, O.

    1995-01-01

    The Orsay polarized electron source based on the chemi-ionization of aligned He(2 3 S 1 ) atoms and CO 2 molecules is briefly described. The latest results concerning electron polarization and beam emittance are presented. The present development status is also discussed. (K.A.)

  3. Modeling diffusion coefficients in binary mixtures of polar and non-polar compounds

    DEFF Research Database (Denmark)

    Medvedev, Oleg; Shapiro, Alexander

    2005-01-01

    The theory of transport coefficients in liquids, developed previously, is tested on a description of the diffusion coefficients in binary polar/non-polar mixtures, by applying advanced thermodynamic models. Comparison to a large set of experimental data shows good performance of the model. Only f...

  4. Radiography and tomography with polarized neutrons

    International Nuclear Information System (INIS)

    Treimer, Wolfgang

    2014-01-01

    Neutron imaging became important when, besides providing impressive radiographic and tomographic images of various objects, physical, quantification of chemical, morphological or other parameters could be derived from 2D or 3D images. The spatial resolution of approximately 50 µm (and less) yields real space images of the bulk of specimens with more than some cm 3 in volume. Thus the physics or chemistry of structures in a sample can be compared with scattering functions obtained e.g. from neutron scattering. The advantages of using neutrons become more pronounced when the neutron spin comes into play. The interaction of neutrons with magnetism is unique due to their low attenuation by matter and because their spin is sensitive to magnetic fields. Magnetic fields, domains and quantum effects such as the Meissner effect and flux trapping can only be visualized and quantified in the bulk of matter by imaging with polarized neutrons. This additional experimental tool is gaining more and more importance. There is a large number of new fields that can be investigated by neutron imaging, not only in physics, but also in geology, archeology, cultural heritage, soil culture, applied material research, magnetism, etc. One of the top applications of polarized neutron imaging is the large field of superconductivity where the Meissner effect and flux pinning can be visualized and quantified. Here we will give a short summary of the results achieved by radiography and tomography with polarized neutrons. - Highlights: • Radiography and tomography with polarized neutrons yield new results concerning the suppressed Meissner effect and magnetic flux trapping. • Suppressed Meissner effect was observed in pure lead samples and niobium. • Trapped magnetic fields in cylindrical Pb samples are squeezed around the rod axis. • The shape and the amount of trapped fields could be determined and quantified

  5. Radiography and tomography with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Treimer, Wolfgang, E-mail: treimer@helmholtz-berlin.de [University of Applied Sciences, Beuth Hochschule für Technik Berlin, Department Mathematics Physics and Chemistry, Luxemburgerstr. 10, D-13353 Berlin (Germany); Helmholtz Zentrum für Materialien und Energie, Department G – GTOMO, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

    2014-01-15

    Neutron imaging became important when, besides providing impressive radiographic and tomographic images of various objects, physical, quantification of chemical, morphological or other parameters could be derived from 2D or 3D images. The spatial resolution of approximately 50 µm (and less) yields real space images of the bulk of specimens with more than some cm{sup 3} in volume. Thus the physics or chemistry of structures in a sample can be compared with scattering functions obtained e.g. from neutron scattering. The advantages of using neutrons become more pronounced when the neutron spin comes into play. The interaction of neutrons with magnetism is unique due to their low attenuation by matter and because their spin is sensitive to magnetic fields. Magnetic fields, domains and quantum effects such as the Meissner effect and flux trapping can only be visualized and quantified in the bulk of matter by imaging with polarized neutrons. This additional experimental tool is gaining more and more importance. There is a large number of new fields that can be investigated by neutron imaging, not only in physics, but also in geology, archeology, cultural heritage, soil culture, applied material research, magnetism, etc. One of the top applications of polarized neutron imaging is the large field of superconductivity where the Meissner effect and flux pinning can be visualized and quantified. Here we will give a short summary of the results achieved by radiography and tomography with polarized neutrons. - Highlights: • Radiography and tomography with polarized neutrons yield new results concerning the suppressed Meissner effect and magnetic flux trapping. • Suppressed Meissner effect was observed in pure lead samples and niobium. • Trapped magnetic fields in cylindrical Pb samples are squeezed around the rod axis. • The shape and the amount of trapped fields could be determined and quantified.

  6. Characterization of polarized THP-1 macrophages and polarizing ability of LPS and food compounds.

    Science.gov (United States)

    Chanput, Wasaporn; Mes, Jurriaan J; Savelkoul, Huub F J; Wichers, Harry J

    2013-02-01

    Little is known about the polarizing potential of currently used human macrophage cell lines, while a better understanding phenomena can support the prediction of effects in vivo based on in vitro analysis. To test the polarization capability of PMA differentiated-THP-1 macrophages (M0), cells were stimulated with 20 ng ml(-1) IFNγ + 1 μg ml(-1) LPS and 20 ng ml(-1) IL-4, which are known to influence macrophage polarization in vivo and ex vivo into the M1 and M2 state, respectively. Apart from several well-known M1 and M2 markers, also new possible markers for M1 and M2 polarization were analysed in this study. The expression of M1 marker genes was up-regulated in IFNγ + LPS stimulated-M0 THP-1 macrophages. The IL-4 stimulated-M0 THP-1 macrophages expressed M2 cell membrane receptor genes. However, M2 chemokine and their receptor genes were only slightly up-regulated which might be due to the complexity of the secondary cell-cell interaction of the chemokine system. Lipopolysaccharides from E. coli (LPS) and food compounds [lentinan, vitamin D3 (vD3) and the combination of lentinan + vitamin D3 (Len + vD3)] were investigated for their polarizing ability on M0 THP-1 macrophages towards either the M1 or M2 state. LPS (700 ng ml(-1)) was able to skew M0 THP-1 macrophages towards the M1 direction since all analysed M1 marker genes were strongly expressed. Lentinan, vD3 and Len + vD3 did not induce expression of either M1 or M2 markers, indicating no polarizing ability of these compounds. Based on the expression of M1 and M2 marker genes we concluded that THP-1 macrophages could be successfully polarized into either the M1 or M2 state. Therefore, they can be used as a new macrophage polarizing model to estimate the polarizing/switching ability of test food compounds.

  7. Radiochromic film and polarization effects

    International Nuclear Information System (INIS)

    Yu, P.K.N.; Cheung, T.; Butson, M.J.; Cancer Services, Wollongong, NSW; Inwood, D.

    2004-01-01

    Full text: A new high sensitivity radiochromic film has been tested for its polarization properties. Gafchromic HS film has been shown to produce a relatively small (less than 3%) variation in measured optical density measured at 660nm wavelength when the light source is fully linear polarized and the film is rotated through 360 deg angle. Similar variations are seen when the detector is linearly polarized. If both light source and detector is linearly polarised variations in measured optical density can reach 15% when the film is rotated through 360 deg angle. This seems to be due to a phase shift in polarised light caused by the radiochromic film resulting in the polarised light source becoming out of phase with the polarised detector. Gafchromic HS radiochromic film produces a minimal polarization response with varying angle of rotation however we recommend that a polarization test be performed on a densitometry system to establish the extent of its polarization properties before accuracy dosimetry is performed with radiochromic HS film. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  8. Tracking polar lows in CLM

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, M.; Storch, H. von [Inst. for Coastal Research, GKSS Research Center, Geesthacht (Germany); Meteorological Inst., Univ. of Hamburg (Germany)

    2008-08-15

    Polar lows are severe cyclones in sub-polar oceans sized beyond the resolved scale of existing global reanalysis products. We used the NCEP/NCAR reanalyses data to drive a regional climate model (CLM) in order to reproduce finer resolved atmospheric fields over the North Atlantic over a two year period. In these fields we detected polar lows by means of a detection algorithm based on a spatial digital bandpass filter. CLM was run in two different ways, the conventional way and with additionally prescribing the analysed large scale situation. The resulting temporal and spatial distributions of polar lows between the different simulations are compared. A reasonable seasonal cycle and spatial distribution was found for all simulations. A lower number of polar lows in the spectral nudged simulation indicates a closer vicinity to reality. Higher temporal and spatial variability between the conventional simulations suggest a more random generation of polar lows. Frequency distributions of track-lengths reveal shorter tracks when nudging is applied. Maximum wind speeds reveal only minor, insignificant differences between all runs and are higher in conventional mode. (orig.)

  9. 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.

  10. 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.

  11. Determining Polarities Of Distant Lightning Strokes

    Science.gov (United States)

    Blakeslee, Richard J.; Brook, Marx

    1990-01-01

    Method for determining polarities of lightning strokes more than 400 km away. Two features of signal from each stroke correlated. New method based on fact each stroke observed thus far for which polarity determined unambiguously, initial polarity of tail same as polarity of initial deflection before initial-deflection signal altered by propagation effects. Receiving station equipped with electric-field-change antenna coupled to charge amplifier having time constant of order of 1 to 10 seconds. Output of amplifier fed to signal-processing circuitry, which determines initial polarity of tail.

  12. Circularly polarized light to study linear magneto-optics for ferrofluids: θ-scan technique

    Science.gov (United States)

    Meng, Xiangshen; Huang, Yan; He, Zhenghong; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Li, Jian; Qiu, Xiaoyan

    2018-06-01

    Circularly polarized light can be divided into two vertically linearly polarized light beams with  ±π/2 phase differences. In the presence of an external magnetic field, when circularly polarized light travels through a ferrofluid film, whose thickness is no more than that of λ/4 plate, magneto-optical, magnetic birefringence and dichroism effects cause the transmitted light to behave as elliptically polarized light. Using angular scan by a continuously rotating polarizer as analyzer, the angular (θ) distribution curve of relative intensity (T) corresponding to elliptically polarized light can be measured. From the T  ‑  θ curve having ellipsometry, the parameters such as the ratio of short to long axis, and angular orientation of the long axis to the vertical field direction can be obtained. Thus, magnetic birefringence and dichroism can be probed simultaneously by measuring magneto-optical, positive or negative birefringence and dichroism features from the transmission mode. The proposed method is called θ-scan technique, and can accurately determine sample stability, magnetic field direction, and cancel intrinsic light source ellipticity. This study may be helpful to further research done to ferrofluids and other similar colloidal samples with anisotropic optics.

  13. 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%.

  14. 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.

  15. Polarization effects in hadron fragmentation

    International Nuclear Information System (INIS)

    Lednicky, R.

    1984-01-01

    Hadron polarization (spin alignment) and polarization asymmetry are discussed in terms of the quark recombination model with the spin-orbit interaction taken into account. It is shown that predictions of this model are at least in qualitative agreement with experimental data. Various polarization mechanisms in terms of this model and the possibility of their checking are also discussed

  16. FIRST POLARIZED PROTON COLLISIONS AT RHIC

    International Nuclear Information System (INIS)

    ROSER, T.; AHRENS, L.; ALESSI, J.; BAI, M.; BEEBE-WANG, J.; BRENNAN, J.M.; BROWN, K.A.; BUNCE, G.; CAMERON, P.; COURANT, E.D.; DREES, A.; FISCHER, W.; FLILLER, R. III; GLENN, W.; HUANG, H.; LUCCIO, A.U.; MACKAY, W.W.; MAKDISI, Y.; MONTAG, C.; PILAT, F.; PTITSYN, V.; SATOGATA, T.

    2002-01-01

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180 o about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV

  17. Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

    Directory of Open Access Journals (Sweden)

    Nicolas P. Tambellini

    2013-07-01

    Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

  18. Polarization Measurements in High-Energy Deuteron Photodisintegration

    International Nuclear Information System (INIS)

    Adam Sarty; Andrei Afanasev; Arunava Saha; Bogdan Wojtsekhowski; Brendan Fox; Chang, C.; Cathleen Jones; Charles Glashausser; Charles Perdrisat; Cornelis De Jager; Cornelis De Jager; Cornelis de Jager; Crovelli, D.; Daniel Simon; David Meekins; Demetrius Margaziotis; Dipangkar Dutta; Edgar Kooijman; Edward Brash; Edward Kinney; Elaine Schulte; Eugene Chudakov; Feng Xiong; Franco Garibaldi; Garth Huber; Gerfried Kumbartzki; Guido Urciuoli; Haiyan Gao; James Kelly; Javier Gomez; Jens-Ole Hansen; Jian-Ping Chen; John Calarco; John LeRose; Jordan Hovdebo; Joseph Mitchell; Juncai Gao; Kamal Benslama; Kathy McCormick; Kevin Fissum; Konrad Aniol; Krishni Wijesooriya; Louis Bimbot; Ludyvine Morand; Luminita Todor; Marat Rvachev; Mark Jones; Martin Epstein; Meihua Liang; Michael Kuss; Moskov Amarian; Nilanga Liyanage; Oleksandr Glamazdin; Olivier Gayou; Paul Ulmer; Pete Markowitz; Peter Bosted; Holt, R.; Riad Suleiman; Richard Lindgren; Rikki Roche; Robert Michaels; Roman Pomatsalyuk; Ronald Gilman; Ronald Ransome; Salvatore Frullani; Scott Dumalski; Seonho Choi; Sergey Malov; Sonja Dieterich; Steffen Strauch; Stephen Becher; Steve Churchwell; Ting Chang; Viktor Gorbenko; Vina Punjabi; Xiaodong Jiang; Zein-Eddine Meziani; Zhengwei Chai; Wang Xu

    2001-01-01

    We present measurements of the recoil proton polarization for the d(polarized y, polarized p)n reaction at thetac.m. = 90 degrees for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization py vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(y,p)n cross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime

  19. Polarization at LEP: Status and prospects

    International Nuclear Information System (INIS)

    Koutchouk, J.P.

    1993-01-01

    The first evidence of a measurable signal of transverse polarization was observed at the end of 1990. In 1991, polarized beams were repeatedly obtained with average and peak polarization levels of 10 and 19% and used to calibrate the beam energy by resonant depolarization. Simulation studies show that the polarization level can be increased above the 50% by harmonic spin matching. This is sufficient to open the possibility of doing physics with longitudinally polarized beams. A spin rotator has been designed for LEP. The feasibility study of operating LEP in this mode concludes at the possibility of providing polarized beams at a good performance level, if the high photon background can be reduced to a tolerable level. (author). 10 refs, 3 figs, 5 tabs

  20. 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.