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Sample records for learners anita bright

  1. Pollination biology of basal angiosperms (ANITA Grade)

    Science.gov (United States)

    Leonard B. Thien; Peter Bernhardt; Margaret S. Devall; Zhi-Duan Chen; Yi-bo Luo; Jian-Hua Fan; Liang-Chen Yuan; Joseph H. Williams

    2009-01-01

    The fi rst three branches of the angiosperm phylogenetic tree consist of eight families with ~201 species of plants (the ANITA grade). The oldest fl ower fossil for the group is dated to the Early Cretaceous (115 – 125 Mya) and identifi ed to the Nymphaeales. The fl owers of extant plants in the ANITA grade are small, and pollen is the edible reward (rarely nectar or...

  2. Krassavitsa protiv tshudovishtshja / Anita-Lucia Roddick ; interv. Oksana Bondar

    Index Scriptorium Estoniae

    Roddick, Anita-Lucia

    2005-01-01

    Intervjuu rahvusvahelise kosmeetikafirma The Body Shop looja, ühiskonnategelase ja keskkonnakaitsja Anita Roddick'uga. Firma The Body Shop osalemisest rahvusvahelises perevägivalla-vastases kampaanias

  3. Extreme Energy Particle Astrophysics with ANITA-V

    Science.gov (United States)

    Wissel, Stephanie

    This proposal is in collaboration with Peter Gorham at the University of Hawaii, who is the PI of the lead proposal. Co-I Wissel and her group at California Polytechnic State University (Cal Poly) will be responsible for calibration equipment upgrades, calibration equipment, and deployment of the calibration system. The Cal Poly group is planning to provide calibration hardware and software products in support of the analysis of ANITAV data in search of ultra high-energy (UHE) neutrinos and cosmic rays. Wissel (now at Cal Poly, a new collaborating institution for ANITA-5) brings significant experience in the detection of high-energy and ultra-high energy particles to the collaboration, leveraging her thirteen years of experience in particle astrophysics and previous work on ANITA-III and ANITA-IV.

  4. Listening for UHE Neutrinos with the ANITA LDB instrument

    International Nuclear Information System (INIS)

    Link, J.T.

    2005-01-01

    The Antarctic Impulsive Transient Antenna, ANITA is a balloon-borne array of sensitive antennas that will listen over the Antarctic continent for radio Cherenkov emissions caused by the interaction of ultra high energy neutrino particles due to the Askaryan effect in the Antarctic ice. These GZK neutrinos provide a unique opportunity to probe the ultra-high energy universe as they are not subject to interactions with or scattering off magnetic or radiation fields like the CMB. ANITA has been selected to fly on a NASA long duration balloon currently set for launch in December 2006

  5. ANITA-2000, Isotope Inventories from Neutron Irradiation, for Fusion Applications

    International Nuclear Information System (INIS)

    Cepraga, Dan-Gabriel

    2000-01-01

    1 - Description of program or function: ANITA-2000 is a code package for the activation characterisation of materials exposed to neutrons in fusion machines. The main component of the package is the activation code ANITA-4M that computes the radioactive inventory of a material exposed to neutron irradiation, continuous or stepwise. It provides activity, atomic density, decay heat, biological hazard, clearance index and gamma-ray source spectra at shut down and for different cooling times. An interactive utility module, MODBIN, to produce the neutron activation cross sections libraries in the required binary ANITA-4M Format, is also included. The GRANITA interactive module may plot activation parameters as a function of the cooling time. The main improvements include: -the number of irradiation time intervals has been increased to 2000; -different neutron wall loading can be used for each burn time interval; -the photon source calculation in the 18 energy group Scale structure has been added; -the clearance index can be calculated. In addition the code language has been standardized to Fortran '95 - by maintaining the backward compatibility (except for the time/date routines) - so as the same code package can be compiled and run on Unix environment and on PC, both under DOS-Windows and under Linux. 2 - Methods: The mathematical solution of the problem is given in analytical form using recurrence relations. Double precision arithmetic is used

  6. ANITA Air Monitoring on the International Space Station: Results Compared to Other Measurements

    Science.gov (United States)

    Honne, A.; Schumann-Olsen, H.; Kaspersen, K.; Limero, T.; Macatangay, A.; Mosebach, H.; Kampf, D.; Mudgett, P. D.; James, J. T.; Tan, G.; hide

    2009-01-01

    ANITA (Analysing Interferometer for Ambient Air) is a flight experiment precursor for a permanent continuous air quality monitoring system on the ISS (International Space Station). For the safety of the crew, ANITA can detect and quantify quasi-online and simultaneously 33 gas compounds in the air with ppm or sub-ppm detection limits. The autonomous measurement system is based on FTIR (Fourier Transform Infra-Red spectroscopy). The system represents a versatile air quality monitor, allowing for the first time the detection and monitoring of trace gas dynamics in a spacecraft atmosphere. ANITA operated on the ISS from September 2007 to August 2008. This paper summarizes the results of ANITA s air analyses with emphasis on comparisons to other measurements. The main basis of comparison is NASA s set of grab samples taken onboard the ISS and analysed on ground applying various GC-based (Gas Chromatography) systems.

  7. Guy ja Anita kõnelevad kaladega kui omasugustega / Kristel Kossar

    Index Scriptorium Estoniae

    Kossar, Kristel

    2005-01-01

    22.-25.09. 2005 toimuvalt Matsalu III rahvusvaheliselt loodusfilmide festivalilt Lihulas. Inglise-prantsuse merebioloogide-allveefilmide autorite Anita ja Guy Chaumette'i filmid "Täiuslik riff" ja "Räägime kaladega"

  8. Experience from start-ups of the first ANITA Mox plants.

    Science.gov (United States)

    Christensson, M; Ekström, S; Andersson Chan, A; Le Vaillant, E; Lemaire, R

    2013-01-01

    ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the 'BioFarm concept', has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3-15% of the added carriers being from the 'BioFarm', with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m³ d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N₂O emissions, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.

  9. DIASPORIC HISTORY AND TRANSNATIONAL NETWORKS IN ANITA DESAI’S BAUMGARTNER’S BOMBAY

    Directory of Open Access Journals (Sweden)

    Lucio De Capitani

    2015-11-01

    Full Text Available Anita Desai’s Baumgartner’s Bombay adopts the perspective of a German Jewish Holocaust survivor and of a former cabaret performer to connect the histories of Germany and India. This paper examines how these characters – witnesses to a multiplicity of stories and receptacles of a variety of cultural instances – engender a diasporic network that dismantles the solidity of official history and grants a meaning to the desolate experience of exile.

  10. Tropical, de Anita Malfatti: reorientando uma velha questão

    Directory of Open Access Journals (Sweden)

    Tadeu Chiarelli

    2008-03-01

    Full Text Available A partir da análise de Tropical, tela pintada por Anita Malfatti em 1917, este artigo propõe que a artista procedia a uma mudança em sua linguagem pictórica, afastando-se das concepções de vanguarda que adotara até então para, aderindo ao clima de retorno à ordem internacional, aproximar-se das discussões sobre o nacionalismo na arte, presentes na cena paulistana. Assim, a imagem de mulher insegura que mudou sua perspectiva por causa da crítica de Monteiro Lobato adquire outra conotação. Os modernistas teriam preferido essa interpretação a efetuar uma análise da obra de Anita Malfatti, por meio da qual se poderia desvelar uma deserção do programa vanguardista feita de forma consciente pela artista.Looking back at the issue of a lecture given at Pinacoteca do Estado (São Paulo, Brazil in 2003, this article, based on the analysis of Tropical, canvas painted by Anita Malfatti in 1917, proposes that the artist, contrary to what has traditionally been stated, was undergoing a change in her pictorial language, distancing herself from the vanguard conceptions she had been embracing up to that date. In so doing, she would align with the international trend of the Rappel à l'ordre and approach the discussions on nationalism in art, present in the art millieu of São Paulo city. Thus, the image of an insecure woman who changed her perspective because of the famous review by Monteiro Lobato, acquires another connotation. Modernists would have preferred, and reiterated, this interpretation instead of making an analysis of Anita Malfatti's work per se, through which a volunteer desertion from the vanguard program could be unveiled.

  11. Antarctic Surface Reflectivity Measurements from the ANITA-3 and HiCal-1 Experiments

    Science.gov (United States)

    Gorham, P. W.; Allison, P.; Banerjee, O.; Beatty, J. J.; Belov, K.; Besson, D. Z.; Binns, W. R.; Bugaev, V.; Cao, P.; Chen, C.; Chen, P.; Clem, J. M.; Connolly, A.; Dailey, B.; Dasgupta, P.; Deaconu, C.; Cremonesi, L.; Dowkontt, P. F.; Fox, B. D.; Gordon, J.; Hill, B.; Hupe, R.; Israel, M. H.; Jain, P.; Kowalski, J.; Lam, J.; Learned, J. G.; Liewer, K. M.; Liu, T. C.; Matsuno, S.; Miki, C.; Mottram, M.; Mulrey, K.; Nam, J.; Nichol, R. J.; Novikov, A.; Oberla, E.; Prohira, S.; Rauch, B. F.; Romero-Wolf, A.; Rotter, B.; Ratzlaff, K.; Russell, J.; Saltzberg, D.; Seckel, D.; Schoorlemmer, H.; Stafford, S.; Stockham, J.; Stockham, M.; Strutt, B.; Tatem, K.; Varner, G. S.; Vieregg, A. G.; Wissel, S. A.; Wu, F.; Young, R.

    The primary science goal of the NASA-sponsored ANITA project is measurement of ultra-high energy neutrinos and cosmic rays, observed via radio-frequency signals resulting from a neutrino or cosmic ray interaction with terrestrial matter (e.g. atmospheric or ice molecules). Accurate inference of the energies of these cosmic rays requires understanding the transmission/reflection of radio wave signals across the ice-air boundary. Satellite-based measurements of Antarctic surface reflectivity, using a co-located transmitter and receiver, have been performed more-or-less continuously for the last few decades. Our comparison of four different reflectivity surveys, at frequencies ranging from 2 to 45GHz and at near-normal incidence, yield generally consistent maps of high versus low reflectivity, as a function of location, across Antarctica. Using the Sun as an RF source, and the ANITA-3 balloon borne radio-frequency antenna array as the RF receiver, we have also measured the surface reflectivity over the interval 200-1000MHz, at elevation angles of 12-30∘. Consistent with our previous measurement using ANITA-2, we find good agreement, within systematic errors (dominated by antenna beam width uncertainties) and across Antarctica, with the expected reflectivity as prescribed by the Fresnel equations. To probe low incidence angles, inaccessible to the Antarctic Solar technique and not probed by previous satellite surveys, a novel experimental approach (“HiCal-1”) was devised. Unlike previous measurements, HiCal-ANITA constitute a bi-static transmitter-receiver pair separated by hundreds of kilometers. Data taken with HiCal, between 200 and 600MHz shows a significant departure from the Fresnel equations, constant with frequency over that band, with the deficit increasing with obliquity of incidence, which we attribute to the combined effects of possible surface roughness, surface grain effects, radar clutter and/or shadowing of the reflection zone due to Earth

  12. Noorte suitsidaalne käitumine - ennetus, märkamine ja sekkumine / Merike Sisask ; kommenteerinud Anita Rõbkina

    Index Scriptorium Estoniae

    Sisask, Merike, 1968-

    2015-01-01

    Kommentaaris Anita Rõbkina Tallinna Ülikooli Pedagoogilise Seminari noorsootöö eriala lõputööst, mille üks eesmärk oli uurida nootsootöötajate teadlikkust ja hinnanguid noorte suitsidaalse käitumise ennetamise võimalustest

  13. Energy and flux measurements of ultra-high energy cosmic rays observed during the first ANITA flight

    Energy Technology Data Exchange (ETDEWEB)

    Schoorlemmer, H.; Belov, K.; Romero-Wolf, A.; García-Fernández, D.; Bugaev, V.; Wissel, S. A.; Allison, P.; Alvarez-Muñiz, J.; Barwick, S. W.; Beatty, J. J.; Besson, D. Z.; Binns, W. R.; Carvalho Jr., W. R.; Chen, C.; Chen, P.; Clem, J. M.; Connolly, A.; Dowkontt, P. F.; DuVernois, M. A.; Field, R. C.; Goldstein, D.; Gorham, P. W.; Hast, C.; Huege, T.; Heber, C. L.; Hoover, S.; Israel, M. H.; Javaid, A.; Kowalski, J.; Lam, J.; Learned, J. G.; Link, J. T.; Lusczek, E.; Matsuno, S.; Mercurio, B. C.; Miki, C.; Miočinović, P.; Mulrey, K.; Nam, J.; Naudet, C. J.; Ng, J.; Nichol, R. J.; Palladino, K.; Rauch, B. F.; Roberts, J.; Reil, K.; Rotter, B.; Rosen, M.; Ruckman, L.; Saltzberg, D.; Seckel, D.; Urdaneta, D.; Varner, G. S.; Vieregg, A. G.; Walz, D.; Wu, F.; Zas, E.

    2016-04-01

    The first flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment recorded 16 radio signals that were emitted by cosmic-ray induced air showers. The dominant contribution to the radiation comes from the deflection of positrons and electrons in the geomagnetic field, which is beamed in the direction of motion of the air shower. For 14 of these events, this radiation is reflected from the ice and subsequently detected by the ANITA experiment at a flight altitude of ~36 km. In this paper, we estimate the energy of the 14 individual events and find that the mean energy of the cosmic-ray sample is 2.9 × 1018 eV, which is significantly lower than the previous estimate. By simulating the ANITA flight, we calculate its exposure for ultra-high energy cosmic rays. We estimate for the first time the cosmic-ray flux derived only from radio observations and find agreement with measurements performed at other observatories. In addition, we find that the ANITA data set is consistent with Monte Carlo simulations for the total number of observed events and with the properties of those events.

  14. Anita Fricek: la pintura contemporánea como mecanismo de crítica institucional

    Directory of Open Access Journals (Sweden)

    Stephen Zepke

    2009-04-01

    Full Text Available Este ensayo formula la pregunta acerca de las relaciones posibles entre el arte contemporáneo y la propuesta estética de Gilles Deleuze. Valiéndose de su propia disyunción, pone en contacto dos asuntos yuxtapuestos: lo “conceptual” y la “sensación”. A partir de esa conexión y a través de la obra pictórica de la artista suiza Anita Fricek, el autor critica la propuesta de estética inmanente de la sensación de Deleuze, y la vincula con el mecanismo de crítica institucional inmerso en la propuesta pictórica-crítica de Fricek.

  15. Clima organizacional percibido por los docentes de las instituciones educativas públicas del nivel inicial distrito de Santa Anita, 2015

    OpenAIRE

    Bernardo Santiago, Sara Marialena

    2015-01-01

    El presente trabajo de investigación titulado “Clima Organizacional Percibido por los docentes de las Instituciones Educativas Públicas del Nivel Inicial Distrito de Santa Anita 2015” contiene información real y confiable. Este consideró como objetivo principal determinar el nivel del Clima organizacional percibido por los docentes de las Instituciones Educativas Públicas del nivel Inicial, distrito de Santa Anita 2015. Se presenta la investigación, bajo un diseño descriptiv...

  16. ANITA (Advanced Network for Isotope and TArget laboratories) - The urgent need for a European target preparation network

    Science.gov (United States)

    Schumann, Dorothea; Sibbens, Goedele; Stolarz, Anna; Eberhardt, Klaus; Lommel, Bettina; Stodel, Christelle

    2018-05-01

    A wide number of research fields in the nuclear sector requires high-quality and well-characterized samples and targets. Currently, only a few laboratories own or have access to the equipment allowing fulfilling such demands. Coordination of activities and sharing resources is therefore mandatory to meet the increasing needs. This very urgent issue has now been addressed by six European target laboratories with an initiative called ANITA (Advanced Network for Isotope and TArget laboratories). The global aim of ANITA is to establish an overarching research infrastructure service for isotope and target production and develop a tight cooperation between the target laboratories in Europe in order to transfer the knowledge and improve the production techniques of well-characterized samples and targets. Moreover, the interaction of the target producers with the users shall be encouraged and intensified to deliver tailor-made targets best-suited to the envisaged experiments. For the realization of this ambitious goal, efforts within the European Commission and strong support by the target-using communities will be necessary. In particular, an appropriate funding instrument has to be found and applied, enabling ANITA to develop from an initiative employed by the interested parties to a real coordination platform.

  17. Residual activity evaluation: a benchmark between ANITA, FISPACT, FLUKA and PHITS codes

    Science.gov (United States)

    Firpo, Gabriele; Viberti, Carlo Maria; Ferrari, Anna; Frisoni, Manuela

    2017-09-01

    The activity of residual nuclides dictates the radiation fields in periodic inspections/repairs (maintenance periods) and dismantling operations (decommissioning phase) of accelerator facilities (i.e., medical, industrial, research) and nuclear reactors. Therefore, the correct prediction of the material activation allows for a more accurate planning of the activities, in line with the ALARA (As Low As Reasonably Achievable) principles. The scope of the present work is to show the results of a comparison between residual total specific activity versus a set of cooling time instants (from zero up to 10 years after irradiation) as obtained by two analytical (FISPACT and ANITA) and two Monte Carlo (FLUKA and PHITS) codes, making use of their default nuclear data libraries. A set of 40 irradiating scenarios is considered, i.e. neutron and proton particles of different energies, ranging from zero to many hundreds MeV, impinging on pure elements or materials of standard composition typically used in industrial applications (namely, AISI SS316 and Portland concrete). In some cases, experimental results were also available for a more thorough benchmark.

  18. Anita: cultivar de alface de verão para cultivo protegido no solo e em hidroponia 'Anita': a new summer lettuce cultivar suitable for protected cultivation in soil and hydroponics systems

    Directory of Open Access Journals (Sweden)

    Ernani Clarete da Silva

    2009-06-01

    Full Text Available 'Anita' é uma cultivar de alface (Lactuca sativa L. do grupo lisa, de cor verde-clara intensa, cujo desenvolvimento se deu a partir de 1994 no município de Campos dos Goytacazes, RJ. Foi selecionada pelo método genealógico a partir do cruzamento entre as cultivares comerciais Vitória e Brasil 303. As plantas contêm diâmetro médio de cabeça de 55 cm, massa fresca de 700 g e número médio de 55 folhas, conforme resultados de ensaios conduzidos nas quatro estações do ano. Possui resistência ao LMV e ao pendoamento precoce em cultivos de verão. As folhas são grandes, macias, crocrantes e adocicadas, sendo estas características mantidas tanto no cultivo protegido no solo quanto em hidroponia.'Anita' is a lettuce cultivar (Lactuca sativa L. of the loose-leaf group whose leaves are of intense green color. This cv. was developed in Campos dos Goytacazes, Rio de Janeiro State, Brazil, since 1994. "Anita" was selected by the pedigree method through crossings between commercial cultivars Vitória and Brasil 303. After evaluations done during four seasons, there were detected a head mean diameter around 55 cm, average fresh plant weight of 700 g and 55 leaves in average. Plants present resistance to Lettuce Mosaic Virus (LMV and high resistance to bolting in the summer. In both cultivation systems, protected environment or hydroponics, plants present leaves of great size, soft and sweet.

  19. Os talentos e a cultura: a trajetória de Anita Malfatti

    Directory of Open Access Journals (Sweden)

    Denise Rocha Belfort Arantes-Brero

    2016-08-01

    Full Text Available Muito se tem pesquisado sobre os indivíduos dotados e talentosos, havendo, em diversos momentos históricos, preocupação com essa população. No Brasil, uma das primeiras vezes em que se falou disso foi na década de 30, por ocasião da fundação da Sociedade Pestalozzi. Apesar desse interesse crescente, na atualidade, existem poucas pesquisas que versam sobre o tema. Este trabalho visa entender como dotação e talento podem se manifestar e serem reconhecidos pela sociedade e cultura na qual a pessoa está inserida, com base na análise da biografia de Anita Malfatti (1889-1964, pintora expressionista, incompreendida em sua época, por ter introduzido uma forma de pintar que não era reconhecida como arte no Brasil. Neste estudo, será apresentada a teoria de Gagné, bem como o que se pretende nomear com os termos dotação e talento. O grande desafio de nossa sociedade é reconhecer as diferenças e valorizá-las, oferecendo a essas pessoas condições para expressão de suas habilidades, garantindo-lhes plena inserção na vida em sociedade para que se sintam produtivas e autorrealizadas. Precisamos lutar contra a “solidão do fundista”, para que o talentoso não esteja sempre adiante dos demais no aspecto intelectual, mas emocionalmente solitário e incompreendido.

  20. La gestión de las políticas sobre los espacios públicos para la infancia en el distrito de Santa Anita

    OpenAIRE

    Torres Saco, José Martín

    2012-01-01

    La tesis titulada GESTIÓN DE LAS POLÍTICAS SOBRE LOS ESPACIOS PÚBLICOS PARA LA INFANCIA EN EL DISTRITO DE SANTA ANITA, que presento como trabajo de investigación para optar el grado de magíster en Gerencia Social, es un trabajo que tiene como esencia describir la preocupación y el estado de promoción del derecho a jugar y a recrearse de niños y niñas en espacios públicos, desde los ámbitos políticos (gobierno local), y sociales (dirigentes, padres y madres), en el distrito de Santa Anita. ...

  1. La gestión administrativa y su influencia en el comportamiento humano de la empresa mercado de productores de Santa Anita

    OpenAIRE

    Colan Aranda, Hugo Humberto

    2014-01-01

    El presente trabajo de investigación titulado "LA GESTIÓN ADMINISTRATIVA Y SU INFLUENCIA EN EL COMPORTAMIENTO HUMANO DE LA EMPRESA MERCADO DE PRODUCTORES DE SANTA ANITA" se realizó con la finalidad de determinar si la Gestión Administrativa, el planeamiento estratégico, la visión, la misión, los objetivos, los reglamentos, normas directivas influyen y son necesarias para brindar un mejor Comportamiento Humano en el Mercado de Productores de Santa Anita. El diseño metodológico de la investigac...

  2. Examining South Atlantic Subtropical Cyclone Anita using the Satellite-Enhanced Regional Downscaling for Applied Studies Hourly Outputs

    Science.gov (United States)

    Vaicberg, H.; Palmeira, A. C. P. A.; Nunes, A.

    2017-12-01

    Studies on South Atlantic cyclones are mainly compromised by scarcity of observations. Therefore, remote sensing and global (re) analysis products are usually employed in investigations of their evolution. However, the frequent use of global reanalysis might difficult the assessment of the characteristics of the cyclones found in South Atlantic. In that regard, studies on "subtropical" cyclones have been performed using the 25-km resolution, Satellite-enhanced Regional Downscaling for Applied Studies (SRDAS), a product developed at the Federal University of Rio de Janeiro in Brazil. In SRDAS, the Regional Spectral Model assimilates precipitation estimates from environmental satellites, while dynamically downscaling a global reanalysis using the spectral nudging technique to maintain the large-scale features in agreement with the regional model solution. The use of regional models in the downscaling of general circulation models provides more detailed information on weather and climate. As a way of illustrating the usefulness of SRDAS in the study of the subtropical South Atlantic cyclones, the subtropical cyclone Anita was selected because of its intensity. Anita developed near Brazilian south/southeast coast, with damages to local communities. Comparisons with available observations demonstrated the skill of SRDAS in simulating such an extreme event.

  3. Burkina Faso - BRIGHT II

    Data.gov (United States)

    Millennium Challenge Corporation — Millennium Challenge Corporation hired Mathematica Policy Research to conduct an independent evaluation of the BRIGHT II program. The three main research questions...

  4. Lasteaeda kujundatakse lapsekesksemaks / Punamäe, Anita; Sarap, Anu; Peterson, Ester; Kala, Sire; Laanemäe-Räim, Consuelo; küsitlenud Kaile Kabun

    Index Scriptorium Estoniae

    2007-01-01

    Vestlusringis on maavalitsuse haridus- ja kultuuriosakonna peaspetsialist Anita Punamäe, Parksepa lasteaia juhataja Anu Sarap, Päkapiku lasteaia juhataja asetäitja õppekasvatustöö alal Ester Peterson, Sõlekese lasteaia õpetaja Sire Kala, lapsevanem ja lasteaia Punamütsike hoolekogu liige Consuelo Laanemäe-Räim

  5. ANITA-2000 activation code package - updating of the decay data libraries and validation on the experimental data of the 14 MeV Frascati Neutron Generator

    Directory of Open Access Journals (Sweden)

    Frisoni Manuela

    2016-01-01

    Full Text Available ANITA-2000 is a code package for the activation characterization of materials exposed to neutron irradiation released by ENEA to OECD-NEADB and ORNL-RSICC. The main component of the package is the activation code ANITA-4M that computes the radioactive inventory of a material exposed to neutron irradiation. The code requires the decay data library (file fl1 containing the quantities describing the decay properties of the unstable nuclides and the library (file fl2 containing the gamma ray spectra emitted by the radioactive nuclei. The fl1 and fl2 files of the ANITA-2000 code package, originally based on the evaluated nuclear data library FENDL/D-2.0, were recently updated on the basis of the JEFF-3.1.1 Radioactive Decay Data Library. This paper presents the results of the validation of the new fl1 decay data library through the comparison of the ANITA-4M calculated values with the measured electron and photon decay heats and activities of fusion material samples irradiated at the 14 MeV Frascati Neutron Generator (FNG of the NEA-Frascati Research Centre. Twelve material samples were considered, namely: Mo, Cu, Hf, Mg, Ni, Cd, Sn, Re, Ti, W, Ag and Al. The ratios between calculated and experimental values (C/E are shown and discussed in this paper.

  6. Santa Anita: la finca, el feudo y el territorio en la nación imaginada por el personaje Fernando Vallejo Santa Anita: Farm, feud and territory in the nation imagined by the character Fernando Vallejo

    Directory of Open Access Journals (Sweden)

    Alberto Cueva Lobelle

    2010-07-01

    Full Text Available La finca de Santa Anita es un espacio emblemático que aparece constantemente en la narrativa de Fernando Vallejo; a través del recuerdo de la finca podemos observar una cosmovisión, una manera de ver el mundo ligada al territorio dentro de una escritura literaria que constituye una práctica social fuertemente contextualizada. En este sentido, la imaginación puede ser entendida como un acto comprometido con la realidad y por ello se apreciará el mérito de las variaciones ideológicas y políticas de las agencias humanas y sociales que la escritura literaria pone en movimiento. Por tanto, se analizará el texto como un documento en el que la relación con el poder se presenta como un testimonio de la existencia de unas más o menos abiertas relaciones de lucha y conflicto.The farm of Santa Anita is an emblematic place constantly appearing in Fernando Vallejo's narrative. Through the memory of the farm, we see a worldview, a way of seeing the world linked to the region within a literary writing which constitutes a highly contextualized social practice. In this sense, we consider the imagination as an act committed to reality and therefore we will appraise the ideological and political changes of human and social agencies that literary writing set in motion. Therefore, we will analyze the text as a document in which the relationship with power is presented as a testimony of the existence of more or less opened relations of struggle and conflict.

  7. BrightFocus Foundation

    Science.gov (United States)

    ... About BrightFocus Foundation Featured Content BrightFocus: Investing in Science to Save Mind and Sight We're here to help. Explore ... recognition is very important. Monday, November 6, 2017 New Diagnosis? Managing a mind and sight disease is a journey. And you’ ...

  8. SiPM-based azimuthal position sensor in ANITA-IV Hi-Cal Antarctic balloon experiment

    Science.gov (United States)

    Novikov, A.; Besson, D.; Chernysheva, I.; Dmitrenko, V.; Grachev, V.; Petrenko, D.; Prohira, S.; Shustov, A.; Ulin, S.; Uteshev, Z.; Vlasik, K.

    2017-01-01

    Hi-Cal (High-Altitude Calibration) is a balloon-borne experiment that will be launched in December, 2016 in Antarctica following ANITA-IV (Antarctic Impulsive Transient Antenna) and will generate a broad-band pulse over the frequency range expected from radiation induced by a cosmic ray shower. Here, we describe a device based on an array of silicon photomultipliers (SiPMs) for determination of the azimuthal position of Hi-Cal. The angular resolution of the device is about 3 degrees. Since at the float altitude of ˜38 km the pressure will be ˜0.5 mbar and temperature ˜ - 20 °C, the equipment has been tested in a chamber over a range of corresponding pressures (0.5 ÷ 1000) mbar and temperatures (-40 ÷ +50) °C.

  9. SiPM-based azimuthal position sensor in ANITA-IV Hi-Cal Antarctic balloon experiment

    International Nuclear Information System (INIS)

    Novikov, A; Besson, D; Chernysheva, I; Dmitrenko, V; Grachev, V; Petrenko, D; Shustov, A; Ulin, S; Uteshev, Z; Vlasik, K; Prohira, S

    2017-01-01

    Hi-Cal (High-Altitude Calibration) is a balloon-borne experiment that will be launched in December, 2016 in Antarctica following ANITA-IV (Antarctic Impulsive Transient Antenna) and will generate a broad-band pulse over the frequency range expected from radiation induced by a cosmic ray shower. Here, we describe a device based on an array of silicon photomultipliers (SiPMs) for determination of the azimuthal position of Hi-Cal. The angular resolution of the device is about 3 degrees. Since at the float altitude of ∼38 km the pressure will be ∼0.5 mbar and temperature ∼ − 20 °C, the equipment has been tested in a chamber over a range of corresponding pressures (0.5 ÷ 1000) mbar and temperatures (−40 ÷ +50) °C. (paper)

  10. Stunningly bright optical emission

    Science.gov (United States)

    Heinke, Craig O.

    2017-12-01

    The detection of bright, rapid optical pulsations from pulsar PSR J1023+0038 have provided a surprise for researchers working on neutron stars. This discovery poses more questions than it answers and will spur on future work and instrumentation.

  11. ANITA-IEAF activation code package - updating of the decay and cross section data libraries and validation on the experimental data from the Karlsruhe Isochronous Cyclotron

    Science.gov (United States)

    Frisoni, Manuela

    2017-09-01

    ANITA-IEAF is an activation package (code and libraries) developed in the past in ENEA-Bologna in order to assess the activation of materials exposed to neutrons with energies greater than 20 MeV. An updated version of the ANITA-IEAF activation code package has been developed. It is suitable to be applied to the study of the irradiation effects on materials in facilities like the International Fusion Materials Irradiation Facility (IFMIF) and the DEMO Oriented Neutron Source (DONES), in which a considerable amount of neutrons with energies above 20 MeV is produced. The present paper summarizes the main characteristics of the updated version of ANITA-IEAF, able to use decay and cross section data based on more recent evaluated nuclear data libraries, i.e. the JEFF-3.1.1 Radioactive Decay Data Library and the EAF-2010 neutron activation cross section library. In this paper the validation effort related to the comparison between the code predictions and the activity measurements obtained from the Karlsruhe Isochronous Cyclotron is presented. In this integral experiment samples of two different steels, SS-316 and F82H, pure vanadium and a vanadium alloy, structural materials of interest in fusion technology, were activated in a neutron spectrum similar to the IFMIF neutron field.

  12. Learner's Passport

    Directory of Open Access Journals (Sweden)

    Bogdan Jug

    1996-12-01

    Full Text Available For the first time learner's passport was pre­ sented at the international conference on permanent education, taking place in Rome in December 1994. This document is not meant for students only but for the entire population. It should contain notes on any format education, additional education, working experiences, cultural activities, sport results, awards, prizes and recommen­ dations. The mission of learner's passport is to gather all documents in one place, a handy book­ let which gives one an overall view over his/her achievements. It should help personnel departments in choosing the right person for a certain job as well as indirectly stimul ate additional activities of the learner's passport holder.

  13. High Brightness OLED Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, Jeffrey [OLEDWorks LLC; Kondakova, Marina [OLEDWorks LLC; Boroson, Michael [OLEDWorks LLC; Hamer, John [OLEDWorks LLC

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  14. High brightness ion source

    International Nuclear Information System (INIS)

    Dreyfus, R.W.; Hodgson, R.T.

    1975-01-01

    A high brightness ion beam is obtainable by using lasers to excite atoms or molecules from the ground state to an ionized state in increments, rather than in one step. The spectroscopic resonances of the atom or molecule are used so that relatively long wavelength, low power lasers can be used to obtain such ion beam

  15. The brightness of colour.

    Directory of Open Access Journals (Sweden)

    David Corney

    Full Text Available The perception of brightness depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its brightness. Specifically, stimuli that are more saturated (i.e. purer in colour appear brighter than stimuli that are less saturated at the same luminance. Similarly, stimuli that are red or blue appear brighter than equiluminant yellow and green stimuli. This non-linear relationship between stimulus intensity and brightness, called the Helmholtz-Kohlrausch (HK effect, was first described in the nineteenth century but has never been explained. Here, we take advantage of the relative simplicity of this 'illusion' to explain it and contextual effects more generally, by using a simple Bayesian ideal observer model of the human visual ecology. We also use fMRI brain scans to identify the neural correlates of brightness without changing the spatial context of the stimulus, which has complicated the interpretation of related fMRI studies.Rather than modelling human vision directly, we use a Bayesian ideal observer to model human visual ecology. We show that the HK effect is a result of encoding the non-linear statistical relationship between retinal images and natural scenes that would have been experienced by the human visual system in the past. We further show that the complexity of this relationship is due to the response functions of the cone photoreceptors, which themselves are thought to represent an efficient solution to encoding the statistics of images. Finally, we show that the locus of the response to the relationship between images and scenes lies in the primary visual cortex (V1, if not earlier in the visual system, since the brightness of colours (as opposed to their luminance accords with activity in V1 as measured with fMRI.The data suggest that perceptions of brightness represent a robust

  16. The Bright Universe Cosmology

    International Nuclear Information System (INIS)

    Surdin, M.

    1980-01-01

    It is shown that viewed from the 'outside', our universe is a black hole. Hence the 'inside' cosmology considered is termed as the Bright Universe Cosmology. The model proposed avoids the singularities of cosmologies of the Big Bang variety, it gives a good account of the redshifts, the cosmic background radiation, the number counts; it also gives a satisfactory explanation of the 'large numbers coincidence' and of the variation in time of fundamental constants. (Auth.)

  17. Kiloamp high-brightness beams

    International Nuclear Information System (INIS)

    Caporaso, G.J.

    1987-01-01

    Brightness preservation of high-current relativistic electron beams under two different types of transport is discussed. Recent progress in improving the brightness of laser-guided beams in the Advanced Test Accelerator is reviewed. A strategy for the preservation of the brightness of space-charge-dominated beams in a solenoidal transport system is presented

  18. Bright point study

    International Nuclear Information System (INIS)

    Tang, F.; Harvey, K.; Bruner, M.; Kent, B.; Antonucci, E.

    1982-01-01

    Transition region and coronal observations of bright points by instruments aboard the Solar Maximum Mission and high resolution photospheric magnetograph observations on September 11, 1980 are presented. A total of 31 bipolar ephemeral regions were found in the photosphere from birth in 9.3 hours of combined magnetograph observations from three observatories. Two of the three ephemeral regions present in the field of view of the Ultraviolet Spectrometer-Polarimeter were observed in the C IV 1548 line. The unobserved ephemeral region was determined to be the shortest-lived (2.5 hr) and lowest in magnetic flux density (13G) of the three regions. The Flat Crystal Spectrometer observed only low level signals in the O VIII 18.969 A line, which were not statistically significant to be positively identified with any of the 16 ephemeral regions detected in the photosphere. In addition, the data indicate that at any given time there lacked a one-to-one correspondence between observable bright points and photospheric ephemeral regions, while more ephemeral regions were observed than their counterparts in the transition region and the corona

  19. High brightness electron accelerator

    International Nuclear Information System (INIS)

    Sheffield, R.L.; Carlsten, B.E.; Young, L.M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of accelerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity. 5 figs

  20. Learner Personas in CALL

    Science.gov (United States)

    Heift, Trude

    2007-01-01

    In examining the titles of this year's conference presentations, the author noticed quite a few papers that focus on learner-specific issues, for instance, papers that address learning styles, learner needs, personality and learning, learner modeling and, more generally, pedagogical issues that deal with individual learner differences in…

  1. “One thing does not exist: Oblivion”. The Poiesis of Everness and the Wildness of Art in Anita Desai’s “The Artist of Disappearance”

    Directory of Open Access Journals (Sweden)

    Daniela Fargione

    2017-11-01

    Full Text Available Anita Desai’s The Artist of Disappearance opens with the first line of “Everness” by Jorge Luis Borges to suggest that nothing can be forgotten except for what is not strong enough to become memory. If oblivion is the main theme of this collection, the eponymous story illustrates the need to preserve (mainly from forgetfulness both cultural and natural artworks. The ethical role of the artist as transmitter of values, together with artistic travail as a tool of preservation are particularly evident in Desai’s reference to Nek Chand’s unauthorized “Rock Garden”. In this article I explore the literary representation of desecrated natural and cultural heritage, postcolonial India’s destruction of naturecultural biodiversity, the decentralization of the human, and the agency of elemental materiality.

  2. The ZTF Bright Transient Survey

    Science.gov (United States)

    Fremling, C.; Sharma, Y.; Kulkarni, S. R.; Miller, A. A.; Taggart, K.; Perley, D. A.; Gooba, A.

    2018-06-01

    As a supplement to the Zwicky Transient Facility (ZTF; ATel #11266) public alerts (ATel #11685) we plan to report (following ATel #11615) bright probable supernovae identified in the raw alert stream from the ZTF Northern Sky Survey ("Celestial Cinematography"; see Bellm & Kulkarni, 2017, Nature Astronomy 1, 71) to the Transient Name Server (https://wis-tns.weizmann.ac.il) on a daily basis; the ZTF Bright Transient Survey (BTS; see Kulkarni et al., 2018; arXiv:1710.04223).

  3. Whose voice matters? Learners

    Directory of Open Access Journals (Sweden)

    Sarah Bansilal

    2010-01-01

    Full Text Available International and national mathematics studies have revealed the poor mathematics skills of South African learners. An essential tool that can be used to improve learners' mathematical skills is for educators to use effective feedback. Our purpose in this study was to elicit learners' understanding and expectations of teacher assessment feedback. The study was conducted with five Grade 9 mathematics learners. Data were generated from one group interview, seven journal entries by each learner, video-taped classroom observations and researcher field notes. The study revealed that the learners have insightful perceptions of the concept of educator feedback. While some learners viewed educator feedback as a tool to probe their understanding, others viewed it as a mechanism to get the educator's point of view. A significant finding of the study was that learners viewed educator assessment feedback as instrumental in building or breaking their self-confidence.

  4. Teradiode's high brightness semiconductor lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

    2016-03-01

    TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

  5. Santa Anita: la finca, el feudo y el territorio en la nación imaginada por el personaje Fernando Vallejo

    Directory of Open Access Journals (Sweden)

    Alberto Cueva Lobelle

    2011-09-01

    Full Text Available La finca de Santa Anita es un espacio emblemático que aparece constantemente en la narrativa de Fernando Vallejo; a través del recuerdo de la finca podemos observar una cosmovisión, una manera de ver el mundo ligada al territorio dentro de una escritura literaria que constituye una práctica social fuertemente contextualizada. En este sentido, la imaginación puede ser entendida como un acto comprometido con la realidad y por ello se apreciará el mérito de las variaciones ideológicas y políticas de las agencias humanas y sociales que la escritura literaria pone en movimiento. Por tanto, se analizará el texto como un documento en el que la relación con el poder se presenta como un testimonio de la existencia de unas más o menos abiertas relaciones de lucha y conflicto.

  6. Helmholtz bright and boundary solitons

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J M [Joule Physics Laboratory, School of Computing, Science and Engineering, Institute for Materials Research, University of Salford, Salford M5 4WT (United Kingdom); McDonald, G S [Joule Physics Laboratory, School of Computing, Science and Engineering, Institute for Materials Research, University of Salford, Salford M5 4WT (United Kingdom); Chamorro-Posada, P [Departmento de TeorIa de la Senal y Comunicaciones e IngenierIa Telematica, Universidad de Valladolid, ETSI Telecomunicacion, Campus Miguel Delibes s/n, 47011 Valladolid (Spain)

    2007-02-16

    We report, for the first time, exact analytical boundary solitons of a generalized cubic-quintic nonlinear Helmholtz (NLH) equation. These solutions have a linked-plateau topology that is distinct from conventional dark soliton solutions; their amplitude and intensity distributions are spatially delocalized and connect regions of finite and zero wave-field disturbances (suggesting also the classification as 'edge solitons'). Extensive numerical simulations compare the stability properties of recently derived Helmholtz bright solitons, for this type of polynomial nonlinearity, to those of the new boundary solitons. The latter are found to possess a remarkable stability characteristic, exhibiting robustness against perturbations that would otherwise lead to the destabilizing of their bright-soliton counterparts.

  7. A New Sky Brightness Monitor

    Science.gov (United States)

    Crawford, David L.; McKenna, D.

    2006-12-01

    A good estimate of sky brightness and its variations throughout the night, the months, and even the years is an essential bit of knowledge both for good observing and especially as a tool in efforts to minimize sky brightness through local action. Hence a stable and accurate monitor can be a valuable and necessary tool. We have developed such a monitor, with the financial help of Vatican Observatory and Walker Management. The device is now undergoing its Beta test in preparation for production. It is simple, accurate, well calibrated, and automatic, sending its data directly to IDA over the internet via E-mail . Approximately 50 such monitors will be ready soon for deployment worldwide including most major observatories. Those interested in having one should enquire of IDA about details.

  8. High-brightness injector modeling

    International Nuclear Information System (INIS)

    Lewellen, J.W.

    2004-01-01

    There are many aspects to the successful conception, design, fabrication, and operation of high-brightness electron beam sources. Accurate and efficient modeling of the injector are critical to all phases of the process, from evaluating initial ideas to successful diagnosis of problems during routine operation. The basic modeling tasks will vary from design to design, according to the basic nature of the injector (dc, rf, hybrid, etc.), the type of cathode used (thermionic, photo, field emitter, etc.), and 'macro' factors such as average beam current and duty factor, as well as the usual list of desired beam properties. The injector designer must be at least aware of, if not proficient at addressing, the multitude of issues that arise from these considerations; and, as high-brightness injectors continue to move out of the laboratory, the number of such issues will continue to expand.

  9. Helmholtz bright and boundary solitons

    International Nuclear Information System (INIS)

    Christian, J M; McDonald, G S; Chamorro-Posada, P

    2007-01-01

    We report, for the first time, exact analytical boundary solitons of a generalized cubic-quintic nonlinear Helmholtz (NLH) equation. These solutions have a linked-plateau topology that is distinct from conventional dark soliton solutions; their amplitude and intensity distributions are spatially delocalized and connect regions of finite and zero wave-field disturbances (suggesting also the classification as 'edge solitons'). Extensive numerical simulations compare the stability properties of recently derived Helmholtz bright solitons, for this type of polynomial nonlinearity, to those of the new boundary solitons. The latter are found to possess a remarkable stability characteristic, exhibiting robustness against perturbations that would otherwise lead to the destabilizing of their bright-soliton counterparts

  10. Giant Low Surface Brightness Galaxies

    Science.gov (United States)

    Mishra, Alka; Kantharia, Nimisha G.; Das, Mousumi

    2018-04-01

    In this paper, we present radio observations of the giant low surface brightness (LSB) galaxies made using the Giant Metrewave Radio Telescope (GMRT). LSB galaxies are generally large, dark matter dominated spirals that have low star formation efficiencies and large HI gas disks. Their properties suggest that they are less evolved compared to high surface brightness galaxies. We present GMRT emission maps of LSB galaxies with an optically-identified active nucleus. Using our radio data and archival near-infrared (2MASS) and near-ultraviolet (GALEX) data, we studied morphology and star formation efficiencies in these galaxies. All the galaxies show radio continuum emission mostly associated with the centre of the galaxy.

  11. High brightness semiconductor lasers with reduced filamentation

    DEFF Research Database (Denmark)

    McInerney, John; O'Brien, Peter.; Skovgaard, Peter M. W.

    1999-01-01

    High brightness semiconductor lasers have applications in spectroscopy, fiber lasers, manufacturing and materials processing, medicine and free space communication or energy transfer. The main difficulty associated with high brightness is that, because of COD, high power requires a large aperture...

  12. Electron beam brightness with field immersed emission

    International Nuclear Information System (INIS)

    Boyd, J.K.; Neil, V.K.

    1985-01-01

    The beam quality or brightness of an electron beam produced with field immersed emission is studied with two models. First, an envelope formulation is used to determine the scaling of brightness with current, magnetic field and cathode radius, and examine the equilibrium beam radius. Second, the DPC computer code is used to calculate the brightness of two electron beam sources

  13. Does low surface brightness mean low density?

    NARCIS (Netherlands)

    deBlok, WJG; McGaugh, SS

    1996-01-01

    We compare the dynamical properties of two galaxies at identical positions on the Tully-Fisher relation, but with different surface brightnesses. We find that the low surface brightness galaxy UGC 128 has a higher mass-to-light ratio, and yet has lower mass densities than the high surface brightness

  14. High-brightness rf linear accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines

  15. A escrita de si como prática de uma literatura menor: cartas de Anita Malfatti a Mário de Andrade

    Directory of Open Access Journals (Sweden)

    Marilda Ionta

    2011-01-01

    Full Text Available http://dx.doi.org/10.1590/S0104-026X2011000100007 No interior de uma cultura falocêntrica a escrita epistolar foi considerada peloscríticos literários uma literatura menor. Por sua vez, os historiadores entenderam por longosanos as cartas pessoais como uma fonte de pesquisa inapropriada ao conhecimento histórico.Neste texto, procuro positivar a literatura de si oriunda das correspondências originadas noâmbito privado, destacando que essa forma de produção literária pode ser tão transgressivaquanto a denominada “grande literatura”, isto é, aquela que visa transpor os limites da linguagem,pois nesse caso específico trata-se de recriar a nós mesmos, de transpor as fronteiras do quesomos no espaço intersubjetivo da troca epistolar e da amizade. Assim, interpreto as cartaspessoais da artista plástica paulista Anita Malfatti (1889-1964 endereçadas ao escritor modernistaMário de Andrade (1893-1945 como uma literatura menor, no sentido apontado por GillesDeleuze e Felix Guattari. Essa escrita de caráter privado está associada à construção de umaescultura de si, de uma estética da existência para usar o conceito formulado por MichelFoucault. Portanto, leio a literatura de si das cartas da artista plástica como uma escrituracontra-hegemônica e política, pois nas linhas de suas missivas o enredo que se compõe é o daprodução de uma subjetividade feminina autônoma que resiste às subjetivações ligadas àfamília, ao Estado e à Igreja.

  16. Low surface brightness spiral galaxies

    International Nuclear Information System (INIS)

    Romanishin, W.

    1980-01-01

    This dissertation presents an observational overview of a sample of low surface brightness (LSB) spiral galaxies. The sample galaxies were chosen to have low surface brightness disks and indications of spiral structure visible on the Palomar Sky Survey. They are of sufficient angular size (diameter > 2.5 arcmin), to allow detailed surface photometry using Mayall 4-m prime focus plates. The major findings of this dissertation are: (1) The average disk central surface brightness of the LSB galaxies is 22.88 magnitude/arcsec 2 in the B passband. (2) From broadband color measurements of the old stellar population, we infer a low average stellar metallicity, on the order of 1/5 solar. (3) The spectra and optical colors of the HII regions in the LSB galaxies indicate a lack of hot ionizing stars compared to HII regions in other late-type galaxies. (4) The average surface mass density, measured within the radius containing half the total mass, is less than half that of a sample of normal late-type spirals. (5) The average LSB galaxy neutral hydrogen mass to blue luminosity ratio is about 0.6, significantly higher than in a sample of normal late-type galaxies. (6) We find no conclusive evidence of an abnormal mass-to-light ratio in the LSB galaxies. (7) Some of the LSB galaxies exhibit well-developed density wave patterns. (8) A very crude calculation shows the lower metallicity of the LSB galaxies compared with normal late-type spirals might be explained simply by the deficiency of massive stars in the LSB galaxies

  17. High brightness beams and applications

    International Nuclear Information System (INIS)

    Sheffield, R.L.

    1995-01-01

    This paper describes the present research on attaining intense bright electron beams. Thermionic systems are briefly covered. Recent and past results from the photoinjector programs are given. The performance advantages and difficulties presently faced by researchers using photoinjectors is discussed. The progress that has been made in photocathode materials, both in lifetime and quantum efficiency, is covered. Finally, a discussion of emittance measurements of photoinjector systems and how the measurement is complicated by the non-thermal nature of the electron beam is presented

  18. High-brightness electron injectors

    International Nuclear Information System (INIS)

    Sheffield, R.L.

    1987-01-01

    Free-electron laser (FEL) oscillators and synchrotron light sources require pulse trains of high peak brightness and, in some applications, high-average power. Recent developments in the technology of photoemissive and thermionic electron sources in rf cavities for electron-linac injector applications offer promising advances over conventional electron injectors. Reduced emittance growth in high peak-current electron injectors may be achieved by using high field strengths and by linearizing the radial component of the cavity electric field at the expense of lower shunt impedance

  19. La importancia de la coordinación para la prevención del delito y faltas: el caso de la Comisaría de Santa Anita y el Serenazgo (2015 – 2016)

    OpenAIRE

    Tiburcio Orbezo, Vicente

    2017-01-01

    Esta investigación se justifica, porque se tiene que mejorar esta política pública de coordinación entre instituciones encargadas de la prevención del delito y faltas, para mejorar la inseguridad ciudadana en el Perú. Tomando como referencia de investigación el distrito de Santa Anita, por ser uno de los distritos con más alto índice de inseguridad. Los objetivos están relacionados y enfocados a los factores que impiden una adecuada coordinación entre ambas instituciones, para hacer frente a ...

  20. Whose voice matters? LEARNERS

    African Journals Online (AJOL)

    Erna Kinsey

    the education quality and more specifically learners' mathematical skills are .... worth). Students with a high self-esteem displayed acceptance of feedback .... Thus feedback is portrayed as means of communication of the teacher's view.

  1. ("PROSECUTORS") IN LEARNER D

    African Journals Online (AJOL)

    21616744

    actions against those learners who disrupt teaching and learning or challenge the Code of Conduct. .... American "law" television series and movies);. 2. arrange ..... disciplinary committee, because they wanted to protect their children. It is the ...

  2. WORK AND LEARNER IDENTITY

    DEFF Research Database (Denmark)

    Kondrup, Sissel

    2015-01-01

    The aim of this article is to suggest a theoretical framework than can assess to how people’s engagement in specific historical and social work practices are significant to their development, maintenance or transformation of a learner identity. Such a framework is crucial in order to grasp how...... different groups have distinctive conditions for meeting the obligation of forming a proactive learner identity and engage in lifelong learning prevalent in both national and transnational policies on lifelong learning....

  3. Learner Motivation and Interest

    OpenAIRE

    Daskalovska, Nina; Gudeva, Liljana Koleva; Ivanovska, Biljana

    2012-01-01

    There are a lot of factors which influence success in learning. However, one of the most important factors is the learner’s motivation to reach the desired goals. Research and experience show that learners with strong motivation can achieve a lot regardless of circumstances. Studies of motivation in second language learning have led to several distinctions, one of which is the distinction between integrative and instrumental motivation. According to this distinction, some learners are motivat...

  4. The lowest surface brightness disc galaxy known

    International Nuclear Information System (INIS)

    Davies, J.I.; Phillipps, S.; Disney, M.J.

    1988-01-01

    The discovery of a galaxy with a prominent bulge and a dominant extremely low surface brightness disc component is reported. The profile of this galaxy is very similar to the recently discovered giant low surface brightness galaxy Malin 1. The disc central surface brightness is found to be ∼ 26.4 Rμ, some 1.5 mag fainter than Malin 1 and thus by far the lowest yet observed. (author)

  5. Increasing the Brightness of Light Sources

    OpenAIRE

    Fu, Ling

    2006-01-01

    In modern illumination systems, compact size and high brightness are important features. Light recycling allows an increase of the spectral radiance (brightness) emitted by a light source for the price of reducing the total radiant power. Light recycling means returning part of the emitted light to the source where part of it will escape absorption. As a result, the output brightness can be increased in a restricted phase space, ...

  6. The bright-bright and bright-dark mode coupling-based planar metamaterial for plasmonic EIT-like effect

    Science.gov (United States)

    Yu, Wei; Meng, Hongyun; Chen, Zhangjie; Li, Xianping; Zhang, Xing; Wang, Faqiang; Wei, Zhongchao; Tan, Chunhua; Huang, Xuguang; Li, Shuti

    2018-05-01

    In this paper, we propose a novel planar metamaterial structure for the electromagnetically induced transparency (EIT)-like effect, which consists of a split-ring resonator (SRR) and a pair of metal strips. The simulated results indicate that a single transparency window can be realized in the symmetry situation, which originates from the bright-bright mode coupling. Further, a dual-band EIT-like effect can be achieved in the asymmetry situation, which is due to the bright-bright mode coupling and bright-dark mode coupling, respectively. Different EIT-like effect can be simultaneously achieved in the proposed structure with the different situations. It is of certain significance for the study of EIT-like effect.

  7. Flexible provisioning for adult learners

    NARCIS (Netherlands)

    Hermans, Henry; Janssen, José; Vogten, Hubert; Koper, Rob

    2014-01-01

    In adult education there is a continuous, growing demand for learning opportunities that fit the specific characteristics and preferences of particular learner groups or individual learners. This requires educational institutions to rethink their business and educational models, and develop more

  8. Learners, teachers and curriculum

    DEFF Research Database (Denmark)

    Petersen, Karen Bjerg

    2008-01-01

    of virtual e-learning, interviews with teachers and 10 learner participants in a virtual classroom setting, and discourse analysis of curriculum developed for the particular e-learning course The research has taken place in the context of a study of e-learning and virtual teaching of Danish as a Second...... language for adults. The research results indicate that teachers seem to compensate by trying to create virtual communities of learning. Learners, however, experience disembedded relations. Conversely, curriculum development, on tends to ‘exploit’ the conditions of disembedding social relations in e-learning......, locationally distant”. The aim of the paper is to analyse and discuss how different positions in e-learning settings result in different answers to modernity. These settings can be applied to either teacher, learner or curriculum positions. The research was based on a qualitative longitudinal case study...

  9. Brightness and darkness as perceptual dimensions

    NARCIS (Netherlands)

    Vladusich, T.; Lucassen, M.P.; Cornelissen, F.W.

    2007-01-01

    A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D) space varying from bright to dark. The

  10. SURFACE PHOTOMETRY OF LOW SURFACE BRIGHTNESS GALAXIES

    NARCIS (Netherlands)

    DEBLOK, WJG; VANDERHULST, JM; BOTHUN, GD

    1995-01-01

    Low surface brightness (LSB) galaxies are galaxies dominated by an exponential disc whose central surface brightness is much fainter than the value of mu(B)(0) = 21.65 +/- 0.30 mag arcsec(-2) found by Freeman. In this paper we present broadband photometry of a sample of 21 late-type LSB galaxies.

  11. Brightness Alteration with Interweaving Contours

    Directory of Open Access Journals (Sweden)

    Sergio Roncato

    2012-12-01

    Full Text Available Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation or when lines of different colours are collinear (neon effect or adjacent (watercolour to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread. The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975 and Kanizsa (1979 in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.

  12. Põllumajandustehnikat uuenda aegsasti / Anita Hoole

    Index Scriptorium Estoniae

    Hoole, Anita

    2006-01-01

    Ilmunud ka: Võrumaa Teataja 13. apr. lk. 5. Kagu-Eesti regiooni liisinguhalduri sõnul ei ole põllumehed veel teadvustanud, millised on võimalused kasutada nii Euroopa Liidu fondide vahendeid, aga ka Eestist kättesaadavat ressurssi, mida annavad meie finantsasutused maapiirkondadele laenude ja liisingute näol

  13. The Anita Peridotite, New Zealand

    DEFF Research Database (Denmark)

    Czertowicz, Tom; Scott, James; Waight, Tod Earle

    2016-01-01

    –93, spinel Cr# of 70, orthopyroxene with low Al2O3, and extremely depleted whole-rock geochemical characteristics indicate that the peridotite body experienced >30% melt extraction, probably within the spinel facies. Mineral compositions show some similarity to those of cratonic peridotitic mantle. Rare Cr....../86Sr (0.705–0.706), eNd ( +6.3 to +11.1), 208Pb/204Pb (37.8–38.9) and eHf ( +5.6 to 36.9) indicate that the metasomatic agent, which caused crystallization of clinopyroxene and plagioclase, had an isotopic composition similar to ocean island basalt. On the basis of isotopic data and mineral chemistry...

  14. Bright Sparks of Our Future!

    Science.gov (United States)

    Riordan, Naoimh

    2016-04-01

    My name is Naoimh Riordan and I am the Vice Principal of Rockboro Primary School in Cork City, South of Ireland. I am a full time class primary teacher and I teach 4th class, my students are aged between 9-10 years. My passion for education has developed over the years and grown towards STEM (Science, Technology, Engineering and Mathematics) subjects. I believe these subjects are the way forward for our future. My passion and beliefs are driven by the unique after school programme that I have developed. It is titled "Sparks" coming from the term Bright Sparks. "Sparks" is an after school programme with a difference where the STEM subjects are concentrated on through lessons such as Science, Veterinary Science Computer Animation /Coding, Eco engineering, Robotics, Magical Maths, Chess and Creative Writing. All these subjects are taught through activity based learning and are one-hour long each week for a ten-week term. "Sparks" is fully inclusive and non-selective which gives all students of any level of ability an opportunity to engage into these subjects. "Sparks" is open to all primary students in County Cork. The "Sparks" after school programme is taught by tutors from the different Universities and Colleges in Cork City. It works very well because the tutor brings their knowledge, skills and specialised equipment from their respective universities and in turn the tutor gains invaluable teaching practise, can trial a pilot programme in a chosen STEM subject and gain an insight into what works in the physical classroom.

  15. Designers predict a bright future

    International Nuclear Information System (INIS)

    Statton, T.D.

    1996-01-01

    As power plant designers and builders, there is a bright future for the industry. The demand for electricity will continue to grow, and the need for new plants will increase accordingly. But companies that develop and supply these plants must adapt to new ways of doing business if they expect to see the dawn of this new age. Several factors will have a profound effect on the generation and use of electricity in future years. Instant communications now reach all corners of the globe, making people everywhere aspire to a higher standard of living. The economic surge needed to satisfy these appetites will, in turn, be fed by a network of suppliers who are themselves restructuring to serve global markets, unimpeded by past nationalistic barriers to trade. The strong correlation between economic progress and the growing demand for electricity is well recognized. A ready supply of affordable electricity is a necessary underpinning for any economic expansion. As economies advance and jobs increase, electric demand grows geometrically, fueled by an ever-improving quality of life. Coupled with increasing demand is the worldwide trend toward privatization of the generation industry. The reasons may vary in different parts of the world, but the effect is the same--companies are battling intensely for the right to build or purchase generating facilities. Those companies, like the industry they serve, are themselves in a period of transition. Once a closed, monopolistic group of owners in a predominantly services-based market, they are, thanks to competitive forces, being driven steadily toward a product-based structure

  16. Learners' Perspectives on Authenticity.

    Science.gov (United States)

    Chavez, Monika M. Th.

    A survey investigated the attitudes of second language learners about authentic texts, written and oral, used for language instruction. Respondents were 186 randomly-selected university students of German. The students were administered a 212-item questionnaire (the items are appended) that requested information concerning student demographic…

  17. Gender and Learner Characteristics

    Science.gov (United States)

    Hindal, Huda; Reid, Norman; Whitehead, Rex

    2013-01-01

    It is well established that girls and boys perform differently in traditional examinations in most countries. This study looks at a sample of 754 school students in Kuwait (aged about 13) and explores how boys and girls differ in the performance in a range of tests related to learner characteristics. The fundamental question is how boys and girls…

  18. Empowering Leaders & Learners

    Science.gov (United States)

    Umphrey, Jan

    2013-01-01

    Trevor Greene, the 2013 MetLife/NASSP National High School Principal of the Year, empowers staff members and students to be the best teachers and learners they can be and provides the community resources to support them. In this article, Greene, principal of Toppenish High School in Washington, shares his biggest motivator as a school leader and…

  19. Developing Responsible Learners

    Science.gov (United States)

    Gautum, Satyen; Jangam, Sachin; Loh, Kai Chee

    2018-01-01

    Developing responsible learners is one of the key education challenges of our time. Education literature suggests that for students to see themselves as active and necessary participants in their own learning, it is important that they view themselves as stakeholders in education. This research aims at exploring the effectiveness of instructional…

  20. Bright boys the making of information technology

    CERN Document Server

    Green, Tom

    2010-01-01

    Everything has a beginning. None was more profound-and quite as unexpected-than Information Technology. Here for the first time is the untold story of how our new age came to be and the bright boys who made it happen. What began on the bare floor of an old laundry building eventually grew to rival in size the Manhattan Project. The unexpected consequence of that journey was huge---what we now know as Information Technology. For sixty years the bright boys have been totally anonymous while their achievements have become a way of life for all of us. "Bright Boys" brings them home. By 1950 they'd

  1. Time-resolved brightness measurements by streaking

    Science.gov (United States)

    Torrance, Joshua S.; Speirs, Rory W.; McCulloch, Andrew J.; Scholten, Robert E.

    2018-03-01

    Brightness is a key figure of merit for charged particle beams, and time-resolved brightness measurements can elucidate the processes involved in beam creation and manipulation. Here we report on a simple, robust, and widely applicable method for the measurement of beam brightness with temporal resolution by streaking one-dimensional pepperpots, and demonstrate the technique to characterize electron bunches produced from a cold-atom electron source. We demonstrate brightness measurements with 145 ps temporal resolution and a minimum resolvable emittance of 40 nm rad. This technique provides an efficient method of exploring source parameters and will prove useful for examining the efficacy of techniques to counter space-charge expansion, a critical hurdle to achieving single-shot imaging of atomic scale targets.

  2. BrightStat.com: free statistics online.

    Science.gov (United States)

    Stricker, Daniel

    2008-10-01

    Powerful software for statistical analysis is expensive. Here I present BrightStat, a statistical software running on the Internet which is free of charge. BrightStat's goals, its main capabilities and functionalities are outlined. Three different sample runs, a Friedman test, a chi-square test, and a step-wise multiple regression are presented. The results obtained by BrightStat are compared with results computed by SPSS, one of the global leader in providing statistical software, and VassarStats, a collection of scripts for data analysis running on the Internet. Elementary statistics is an inherent part of academic education and BrightStat is an alternative to commercial products.

  3. Measuring brightness temperature distributions of plasma bunches

    International Nuclear Information System (INIS)

    Kirko, V.I.; Stadnichenko, I.A.

    1981-01-01

    The possibility of restoration of brightness temperature distribution along plasma jet on the base of a simple ultra high- speed photography and subsequent photometric treatment is shown. The developed technique has been applied for finding spectral radiation intensity and brightness temperature of plasma jets of a tubular gas-cumulative charge and explosive plasma compressor. The problem of shock wave front has been successfully solved and thus distribution of above parameters beginning from the region preceeding the shock wave has been obtained [ru

  4. Bright THz Instrument and Nonlinear THz Science

    Science.gov (United States)

    2017-10-30

    Report: Bright THz Instrument and Nonlinear THz Science The views, opinions and/or findings contained in this report are those of the author(s) and...Number: W911NF-16-1-0436 Organization: University of Rochester Title: Bright THz Instrument and Nonlinear THz Science Report Term: 0-Other Email: xi...exploring new cutting-edge research and broader applications, following the significant development of THz science and technology in the late 80’s, is the

  5. The surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1983-01-01

    It is proposed that Freeman's discovery that the extrapolated central surface brightness of spiral galaxies is approximately constant can be simply explained if the galaxies contain a spheroidal component which dominates the light in their outer isophotes. Calculations of an effective central surface brightness indicate a wide spread of values. This requires either a wide spread in disc properties or significant spheroidal components or, most probably, both. (author)

  6. The surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Disney, M.; Phillipps, S.

    1985-01-01

    The intrinsic surface brightness Ssub(e) of 500 disc galaxies (0<=T<=9) drawn from the Second Reference Catalogue is computed and it is shown that Ssub(e) does not correlate significantly with Msub(B), (B-V) or type. This is consistent with the notion that there is a heavy selection bias in favour of disc galaxies with that particular surface brightness which allows inclusion in the catalogue over the largest volume of space. (author)

  7. Brightness masking is modulated by disparity structure.

    Science.gov (United States)

    Pelekanos, Vassilis; Ban, Hiroshi; Welchman, Andrew E

    2015-05-01

    The luminance contrast at the borders of a surface strongly influences surface's apparent brightness, as demonstrated by a number of classic visual illusions. Such phenomena are compatible with a propagation mechanism believed to spread contrast information from borders to the interior. This process is disrupted by masking, where the perceived brightness of a target is reduced by the brief presentation of a mask (Paradiso & Nakayama, 1991), but the exact visual stage that this happens remains unclear. In the present study, we examined whether brightness masking occurs at a monocular-, or a binocular-level of the visual hierarchy. We used backward masking, whereby a briefly presented target stimulus is disrupted by a mask coming soon afterwards, to show that brightness masking is affected by binocular stages of the visual processing. We manipulated the 3-D configurations (slant direction) of the target and mask and measured the differential disruption that masking causes on brightness estimation. We found that the masking effect was weaker when stimuli had a different slant. We suggest that brightness masking is partly mediated by mid-level neuronal mechanisms, at a stage where binocular disparity edge structure has been extracted. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Learner corpus profiles the case of Romanian learner English

    CERN Document Server

    Chitez, Madalina

    2014-01-01

    The first three chapters of the book offer relevant information on the new methodological approach, learner corpus profiling, and the exemplifying case, Romanian Learner English. The description of the Romanian Corpus of Learner English is also given special attention. The following three chapters include corpus-based frequency analyses of selected grammatical categories (articles, prepositions, genitives), combined with error analyses. In the concluding discussion, the book summarizes the features compiled as lexico-grammatical profiles.

  9. Energy-exchange collisions of dark-bright-bright vector solitons.

    Science.gov (United States)

    Radhakrishnan, R; Manikandan, N; Aravinthan, K

    2015-12-01

    We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

  10. Unperturbed moderator brightness in pulsed neutron sources

    International Nuclear Information System (INIS)

    Batkov, K.; Takibayev, A.; Zanini, L.; Mezei, F.

    2013-01-01

    The unperturbed neutron brightness of a moderator can be defined from the number of neutrons leaving the surface of a moderator completely surrounded by a reflector. Without openings for beam extraction, it is the maximum brightness that can be theoretically achieved in a moderator. The unperturbed brightness of a cylindrical cold moderator filled with pure para-H 2 was calculated using MCNPX; the moderator dimensions were optimised, for a fixed target and reflector geometry corresponding to the present concept for the ESS spallation source. This quantity does not depend on openings for beam extraction and therefore can be used for a first-round optimisation of a moderator, before effects due to beam openings are considered. We find that such an optimisation yields to a factor of 2 increase with respect to a conventional volume moderator, large enough to accommodate a viewed surface of 12×12 cm 2 : the unperturbed neutron brightness is maximum for a disc-shaped moderator of 15 cm diameter, 1.4 cm height. The reasons for this increase can be related to the properties of the scattering cross-section of para-H 2 , to the added reflector around the exit surface in the case of a compact moderator, and to a directionality effect. This large optimisation gain in the unperturbed brightness hints towards similar potentials for the perturbed neutron brightness, in particular in conjunction with advancing the optical quality of neutron delivery from the moderator to the sample, where by Liouville theorem the brightness is conserved over the beam trajectory, except for absorption and similar type losses

  11. Intermittent episodes of bright light suppress myopia in the chicken more than continuous bright light.

    Science.gov (United States)

    Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

    2014-01-01

    Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light:dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1:1 or 7:7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1:1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies.

  12. Proxy magnetometry of the photosphere: why are G-band bright points so bright?

    NARCIS (Netherlands)

    Rutten, R.J.; Kiselman, Dan; Voort, Luc Rouppe van der; Plez, Bertrand

    2000-01-01

    We discuss the formation of G-band bright points in terms of standard uxtube modeling, in particular the 1D LTE models constructed by Solanki and coworkers. Combined with LTE spectral synthesis they explain observed G-band bright point contrasts quite well. The G-band contrast increase over the

  13. A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

    NARCIS (Netherlands)

    Nijboer, T.C.W.; Nys, G.M.S.; van der Smagt, M.J.; de Haan, E.H.F.

    2009-01-01

    We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level

  14. A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

    Science.gov (United States)

    Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F

    2009-01-01

    We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for brightness. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of brightness appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of 'brightness agnosia'.

  15. Plasmonic EIT-like switching in bright-dark-bright plasmon resonators.

    Science.gov (United States)

    Chen, Junxue; Wang, Pei; Chen, Chuncong; Lu, Yonghua; Ming, Hai; Zhan, Qiwen

    2011-03-28

    In this paper we report the study of the electromagnetically induced transparency (EIT)-like transmission in the bright-dark-bright plasmon resonators. It is demonstrated that the interferences between the dark plasmons excited by two bright plasmon resonators can be controlled by the incident light polarization. The constructive interference strengthens the coupling between the bright and dark resonators, leading to a more prominent EIT-like transparency window of the metamaterial. In contrary, destructive interference suppresses the coupling between the bright and dark resonators, destroying the interference pathway that forms the EIT-like transmission. Based on this observation, the plasmonic EIT switching can be realized by changing the polarization of incident light. This phenomenon may find applications in optical switching and plasmon-based information processing.

  16. STARS4ALL Night Sky Brightness Photometer

    Directory of Open Access Journals (Sweden)

    Jaime Zamorano

    2017-06-01

    Full Text Available We present the main features of TESS-W, the first version of a series of inexpensive but reliable photometers that will be used to measure night sky brightness. The bandpass is extended to the red with respect of that of the Sky Quality Meter (SQM. TESS-W connects to a router via WIFI and it sends automatically the brightness values to a data repository using Internet of Things protocols. The device includes an infrared sensor to estimate the cloud coverage. It is designed for fixed stations to monitor the evolution of the sky brightness. The photometer could also be used in local mode connected to a computer or tablet to gather data from a moving vehicle. The photometer is being developed within STARS4ALL project, a collective awareness platform for promoting dark skies in Europe, funded by the EU. We intend to extend the existing professional networks to a citizen-based network of photometers. 

  17. Increasing the brightness of light sources

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ling

    2006-11-16

    In this work the principle of light recycling is applied to artificial light sources in order to achieve brightness enhancement. Firstly, the feasibilities of increasing the brightness of light sources via light recycling are examined theoretically, based on the fundamental laws of thermodynamics including Kirchhoff's law on radiation, Planck's law, Lambert-Beer's law, the etendue conservation and the brightness theorem. From an experimental viewpoint, the radiation properties of three different kinds of light sources including short-arc lamps, incandescent lamps and LEDs characterized by their light-generating mechanisms are investigated. These three types of sources are used in light recycling experiments, for the purpose of 1. validating the intrinsic light recycling effect in light sources, e. g. the intrinsic light recycling effect in incandescent lamps stemming from the coiled filament structure. 2. acquiring the required parameters for establishing physical models, e.g. the emissivity/absorptivity of the short-arc lamps, the intrinsic reflectivity and the external quantum efficiency of LEDs. 3. laying the foundations for designing optics aimed at brightness enhancement according to the characteristics of the sources and applications. Based on the fundamental laws and experiments, two physical models for simulating the radiance distribution of light sources are established, one for thermal filament lamps, the other for luminescent sources, LEDs. As validation of the theoretical and experimental investigation of the light recycling effect, an optical device, the Carambola, is designed for achieving deterministic and multiple light recycling. The Carambola has the function of a concentrator. In order to achieve the maximum possible brightness enhancement with the Carambola, several combinations of sources and Carambolas are modelled in ray-tracing simulations. Sources with different light-emitting mechanisms and different radiation properties

  18. Richard Bright and his neurological studies.

    Science.gov (United States)

    Pearce, J M S

    2009-01-01

    Richard Bright was one of the famous triumvirate of Guy's Hospital physicians in the Victorian era. Remembered for his account of glomerulonephritis (Bright's disease) he also made many important and original contributions to medicine and neurology. These included his work on cortical epileptogenesis, descriptions of simple partial (Jacksonian) seizures, infantile convulsions, and a variety of nervous diseases. Most notable were his reports of neurological studies including papers on traumatic tetanus, syringomyelia, arteries of the brain, contractures of spinal origin, tumours of the base of the brain, and narcolepsy. His career and these contributions are outlined. Copyright 2009 S. Karger AG, Basel.

  19. Human CD56bright NK Cells

    DEFF Research Database (Denmark)

    Michel, Tatiana; Poli, Aurélie; Cuapio, Angelica

    2016-01-01

    Human NK cells can be subdivided into various subsets based on the relative expression of CD16 and CD56. In particular, CD56(bright)CD16(-/dim) NK cells are the focus of interest. They are considered efficient cytokine producers endowed with immunoregulatory properties, but they can also become c...... NK cell subsets is not fully defined, nor is their precise hematopoietic origin. In this article, we summarize recent studies about CD56(bright) NK cells in health and disease and briefly discuss the current controversies surrounding them....

  20. Diagnostics for high-brightness beams

    International Nuclear Information System (INIS)

    Shafer, R.E.

    1990-01-01

    Special techniques are required for beam diagnostics on high-brightness particle beams. Examples of high-brightness beams include low-emittance proton linacs (either pulsed or CW), electron linacs suitable for free-electron-laser applications, and future linear colliders. Non-interceptive and minimally-interceptive techniques for measuring beam current, position, profile, and transverse and longitudinal emittance will be reviewed. Included will be stripline, wire scanner, laser neutralization, beam-beam scattering, interceptive microgratings, spontaneous emission, optical transition radiation, and other techniques. 24 refs

  1. Learners' independent records of vocabulary

    DEFF Research Database (Denmark)

    Shaw, Philip; Leeke, Philip

    1999-01-01

    Handbooks recommend a variety of quite complicated procedures for learning and remembering vocabulary, but most learners only engage in very simple procedures. The aim of this project was to establish a basis for identifying optimal vocabulary recording procedures by finding out what learners...

  2. Profiling Mobile English Language Learners

    Science.gov (United States)

    Byrne, Jason; Diem, Robert

    2014-01-01

    The purpose of this study was to use an app-embedded survey to profile language learner demographics. A total of 3,759 EFL language learners from primarily eight L1 backgrounds (French, German, Italian, Japanese, Korean, Russian, Spanish and Thai) responded to the survey embedded within a popular English grammar app. This app has over 500,000…

  3. Tweetalige aanleerderswoordeboek . bilingual learner's dictionary ...

    African Journals Online (AJOL)

    Correct pronunciation is not guaranteed, because only syllabification and the main stress are indicated in words. Grammatical guidance is also not given to such an extent that learners will be able to generate correct sentences on their own. The role that contrastive analysis and error analysis can play to anticipate learners' ...

  4. Autonomous Learner Model Resource Book

    Science.gov (United States)

    Betts, George T.; Carey, Robin J.; Kapushion, Blanche M.

    2016-01-01

    "Autonomous Learner Model Resource Book" includes activities and strategies to support the development of autonomous learners. More than 40 activities are included, all geared to the emotional, social, cognitive, and physical development of students. Teachers may use these activities and strategies with the entire class, small groups, or…

  5. The Eindhoven High-Brightness Electron Programme

    NARCIS (Netherlands)

    Brussaard, G.J.H.; Wiel, van der M.J.

    2004-01-01

    The Eindhoven High-Brightness programme is aimed at producing ultra-short intense electron bunches from compact accelerators. The RF electron gun is capable of producing 100 fs electron bunches at 7.5 MeV and 10 pC bunch charge. The DC/RF hybrid gun under development will produce bunches <75 fs at

  6. Discussion of high brightness rf linear accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1987-01-01

    The fundamental aspects of high-brightness rf linacs are outlined, showing the breadth and complexity of the technology and indicating that synergism with advancements in other areas is important. Areas of technology reviewed include ion sources, injectors, rf accelerator structures, beam dynamics, rf power, and automatic control

  7. Simultaneous brightness contrast of foraging Papilio butterflies

    Science.gov (United States)

    Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

    2012-01-01

    This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

  8. Robust fitting of diurnal brightness temperature cycle

    CSIR Research Space (South Africa)

    Udahemuka, G

    2007-11-01

    Full Text Available for a pixel concerned. Robust fitting of observed Diurnal Temperature Cycle (DTC) taken over a day of a given pixel without cloud cover and other abnormally conditions such as fire can give a data based brightness temperature model for a given pixel...

  9. Intermittent Episodes of Bright Light Suppress Myopia in the Chicken More than Continuous Bright Light

    OpenAIRE

    Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

    2014-01-01

    PURPOSE: Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. METHODS: Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light:dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows....

  10. Intermittent episodes of bright light suppress myopia in the chicken more than continuous bright light.

    Directory of Open Access Journals (Sweden)

    Weizhong Lan

    Full Text Available PURPOSE: Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. METHODS: Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8 was kept under office-like illuminance (500 lux at a 10:14 light:dark cycle. Episodes of bright light (15 000 lux were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5, 2 hours (n = 5, 5 hours (n = 4 or 10 hours (n = 4. Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7, 30 minutes (n = 8, 15 minutes (n = 6, 7 minutes (n = 7 or 1 minute (n = 7 periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. RESULTS: Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1:1 or 7:7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. CONCLUSIONS: The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1:1 min provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies.

  11. Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise.

    Science.gov (United States)

    Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A

    2016-02-26

    Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) bright light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.

  12. Do Low Surface Brightness Galaxies Host Stellar Bars?

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes Sodi, Bernardo; Sánchez García, Osbaldo, E-mail: b.cervantes@irya.unam.mx, E-mail: o.sanchez@irya.unam.mx [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Campus Morelia, A.P. 3-72, C.P. 58089 Michoacán, México (Mexico)

    2017-09-20

    With the aim of assessing if low surface brightness galaxies host stellar bars and by studying the dependence of the occurrence of bars as a function of surface brightness, we use the Galaxy Zoo 2 data set to construct a large volume-limited sample of galaxies and then segregate these galaxies as having low or high surface brightness in terms of their central surface brightness. We find that the fraction of low surface brightness galaxies hosting strong bars is systematically lower than that found for high surface brightness galaxies. The dependence of the bar fraction on the central surface brightness is mostly driven by a correlation of the surface brightness with the spin and the gas richness of the galaxies, showing only a minor dependence on the surface brightness. We also find that the length of the bars is strongly dependent on the surface brightness, and although some of this dependence is attributed to the gas content, even at a fixed gas-to-stellar mass ratio, high surface brightness galaxies host longer bars than their low surface brightness counterparts, which we attribute to an anticorrelation of the surface brightness with the spin.

  13. Do Low Surface Brightness Galaxies Host Stellar Bars?

    International Nuclear Information System (INIS)

    Cervantes Sodi, Bernardo; Sánchez García, Osbaldo

    2017-01-01

    With the aim of assessing if low surface brightness galaxies host stellar bars and by studying the dependence of the occurrence of bars as a function of surface brightness, we use the Galaxy Zoo 2 data set to construct a large volume-limited sample of galaxies and then segregate these galaxies as having low or high surface brightness in terms of their central surface brightness. We find that the fraction of low surface brightness galaxies hosting strong bars is systematically lower than that found for high surface brightness galaxies. The dependence of the bar fraction on the central surface brightness is mostly driven by a correlation of the surface brightness with the spin and the gas richness of the galaxies, showing only a minor dependence on the surface brightness. We also find that the length of the bars is strongly dependent on the surface brightness, and although some of this dependence is attributed to the gas content, even at a fixed gas-to-stellar mass ratio, high surface brightness galaxies host longer bars than their low surface brightness counterparts, which we attribute to an anticorrelation of the surface brightness with the spin.

  14. Bright solitons in Bose-Fermi mixtures

    International Nuclear Information System (INIS)

    Karpiuk, Tomasz; Brewczyk, Miroslaw; RzaPewski, Kazimierz

    2006-01-01

    We consider the formation of bright solitons in a mixture of Bose and Fermi degenerate gases confined in a three-dimensional elongated harmonic trap. The Bose and Fermi atoms are assumed to effectively attract each other whereas bosonic atoms repel each other. Strong enough attraction between bosonic and fermionic components can change the character of the interaction within the bosonic cloud from repulsive to attractive making thus possible the generation of bright solitons in the mixture. On the other hand, such structures might be in danger due to the collapse phenomenon existing in attractive gases. We show, however, that under some conditions (defined by the strength of the Bose-Fermi components attraction) the structures which neither spread nor collapse can be generated. For elongated enough traps the formation of solitons is possible even at the 'natural' value of the mutual Bose-Fermi ( 87 Rb- 40 K in our case) scattering length

  15. Literacy Standards for Preschool Learners.

    Science.gov (United States)

    Bodrova, Elena; Leong, Deborah J.; Paynter, Diane E.

    1999-01-01

    Preschool and kindergarten teachers can help young learners meet early literacy standards without sacrificing developmentally appropriate practice. Several professional associations have described appropriate expectations for children of different age levels known as milestones, developmental accomplishments, and benchmarks. (MLH)

  16. Teachers of adults as learners

    DEFF Research Database (Denmark)

    Lund Larsen, Lea

    This poster is a part of an on-going qualitative empirical research project: “Teachers of adults as learners. A study on teachers’ experiences in practice”. Adult learners have particular needs and characteristics that their teachers must be able to address. Some of the competencies that teachers...... need can be taught in formal settings, but in most teaching settings, the teachers act alone and develop their pedagogical approaches/-teaching strategies with no synchronous sparring from a colleague. Adult learners have particular needs and characteristics that their teachers must be able to address...... (cf. Knowles, Brookfield, Illeris, Lawler, King, Wahlgreen). If we study adult teachers as learners in practice, we may be able to identify what the teachers’ practice requires, and thereby qualify the efforts of teacher educators....

  17. Extreme Ultraviolet Explorer Bright Source List

    Science.gov (United States)

    Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

    1994-01-01

    Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

  18. High-brightness H/sup -/ accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1987-01-01

    Neutral particle beam (NPB) devices based on high-brightness H/sup -/ accelerators are an important component of proposed strategic defense systems. The basic rational and R and D program are outlined and examples given of the underlying technology thrusts toward advanced systems. Much of the research accomplished in the past year is applicable to accelerator systems in general; some of these activities are discussed

  19. Brightness of synchrotron radiation from wigglers

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2014-12-01

    According to literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so called 'depth-of-field' effects. In fact, the particle beam cross section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. In the geometrical optics limit computations can be performed analytically. Within this limit, we restrict ourselves to the case of the beam size-dominated regime, which is typical for synchrotron radiation facilities in the X-ray wavelength range. We give a direct demonstration of the fact that the apparent horizontal source size is broadened in proportion to the beamline opening angle and to the length of the wiggler. While this effect is well-understood, a direct proof appears not to have been given elsewhere. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in literature.

  20. Modular Zero Energy. BrightBuilt Home

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Steven Winter Associates, Inc., Norwalk, CT (United States); Butterfield, Karla [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2016-03-01

    With funding from the Building America Program, part of the U.S. Department of Energy Building Technologies Office, the Consortium for Advanced Residential Buildings (CARB) worked with BrightBuilt Home (BBH) to evaluate and optimize building systems. CARB’s work focused on a home built by Black Bros. Builders in Lincolnville, Maine (International Energy Conservation Code Climate Zone 6). As with most BBH projects to date, modular boxes were built by Keiser Homes in Oxford, Maine.

  1. The surface brightness of spiral galaxies: Pt. 4

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.; Ohio State Univ., Columbus

    1988-01-01

    Using measurements from IRAS correlations are found between optical surface brightness and both infrared-to-optical flux ratio and infrared colour temperature, in the sense that galaxies with high surface brightness have higher FIR emission and higher temperatures. (author)

  2. Search for bright stars with infrared excess

    Energy Technology Data Exchange (ETDEWEB)

    Raharto, Moedji, E-mail: moedji@as.itb.ac.id [Astronomy Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Bright stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25μm (micron) with good flux quality are used to search for bright stars (from Bright Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}−m{sub 25}>0; where m{sub 12}−m{sub 25} = −2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25μm, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.

  3. Condensate bright solitons under transverse confinement

    International Nuclear Information System (INIS)

    Salasnich, L.; Reatto, L.; Parola, A.

    2002-01-01

    We investigate the dynamics of Bose-Einstein condensate bright solitons made of alkali-metal atoms with negative scattering length and under harmonic confinement in the transverse direction. Contrary to the one-dimensional (1D) case, the 3D bright soliton exists only below a critical attractive interaction that depends on the extent of confinement. Such a behavior is also found in multisoliton condensates with box boundary conditions. We obtain numerical and analytical estimates of the critical strength beyond which the solitons do not exist. By using an effective 1D nonpolynomial nonlinear Schroedinger equation, which accurately takes into account the transverse dynamics of cigarlike condensates, we numerically simulate the dynamics of the 'soliton train' reported in a recent experiment [Nature (London) 417, 150 (2002)]. Then, analyzing the macroscopic quantum tunneling of the bright soliton on a Gaussian barrier, we find that its interference in the tunneling region is strongly suppressed with respect to nonsolitonic case; moreover, the tunneling through a barrier breaks the shape invariance of the matter wave. Finally, we show that the collapse of the soliton is induced by the scattering on the barrier or by the collision with another matter wave when the density reaches a critical value, for which we derive an accurate analytical formula

  4. Possible Bright Starspots on TRAPPIST-1

    Science.gov (United States)

    Morris, Brett M.; Agol, Eric; Davenport, James R. A.; Hawley, Suzanne L.

    2018-04-01

    The M8V star TRAPPIST-1 hosts seven roughly Earth-sized planets and is a promising target for exoplanet characterization. Kepler/K2 Campaign 12 observations of TRAPPIST-1 in the optical show an apparent rotational modulation with a 3.3-day period, though that rotational signal is not readily detected in the Spitzer light curve at 4.5 μm. If the rotational modulation is due to starspots, persistent dark spots can be excluded from the lack of photometric variability in the Spitzer light curve. We construct a photometric model for rotational modulation due to photospheric bright spots on TRAPPIST-1 that is consistent with both the Kepler and Spitzer light curves. The maximum-likelihood model with three spots has typical spot sizes of R spot/R ⋆ ≈ 0.004 at temperature T spot ≳ 5300 ± 200 K. We also find that large flares are observed more often when the brightest spot is facing the observer, suggesting a correlation between the position of the bright spots and flare events. In addition, these flares may occur preferentially when the spots are increasing in brightness, which suggests that the 3.3-day periodicity may not be a rotational signal, but rather a characteristic timescale of active regions.

  5. Chinese English Learners' Strategic Competence.

    Science.gov (United States)

    Wang, Dianjian; Lai, Hongling; Leslie, Michael

    2015-12-01

    The present study aims to investigate Chinese English learners' ability to use communication strategies (CSs). The subjects are put in a relatively real English referential communication setting and the analyses of the research data show that Chinese English learners, when encountering problems in foreign language (FL) communication, are characterized by the frequent use of substitution, approximation, circumlocution, literal translation, exemplification, word-coinage, repetition, and the infrequent use of cultural-knowledge and paralinguistic CSs. The rare use of paralinguistic strategies is found to be typical of Chinese English learners. The high frequency of literal translation, one first language (L1)-based strategy in our study sample, suggests that FL learners' use of L1-based CSs may depend more upon the developmental stage of their target language than the typology distance between L1 and the target language. The frequency of repetition reveals one fact that the Chinese English learners lack variety and flexibility in their use of CSs. Based on these findings, it was indicated that learners' use of CSs is influenced by a variety of factors, among which the development stage of their interlanguage and their cultural background are identified as two important factors. Some implications are finally suggested for the English foreign language teaching practice in China.

  6. Star formation and the surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1985-01-01

    The (blue) surface brightness of spiral galaxies is significantly correlated with their Hα linewidth. This can be most plausibly interpreted as a correlation of surface brightness with star formation rate. There is also a significant difference in surface brightness between galaxies forming stars in a grand design spiral pattern and those with floc star formation regions. (author)

  7. Electromagnetically induced transparency control in terahertz metasurfaces based on bright-bright mode coupling

    Science.gov (United States)

    Yahiaoui, R.; Burrow, J. A.; Mekonen, S. M.; Sarangan, A.; Mathews, J.; Agha, I.; Searles, T. A.

    2018-04-01

    We demonstrate a classical analog of electromagnetically induced transparency (EIT) in a highly flexible planar terahertz metamaterial (MM) comprised of three-gap split-ring resonators. The keys to achieve EIT in this system are the frequency detuning and hybridization processes between two bright modes coexisting in the same unit cell as opposed to bright-dark modes. We present experimental verification of two bright modes coupling for a terahertz EIT-MM in the context of numerical results and theoretical analysis based on a coupled Lorentz oscillator model. In addition, a hybrid variation of the EIT-MM is proposed and implemented numerically to dynamically tune the EIT window by incorporating photosensitive silicon pads in the split gap region of the resonators. As a result, this hybrid MM enables the active optical control of a transition from the on state (EIT mode) to the off state (dipole mode).

  8. Investigating the Bright End of LSST Photometry

    Science.gov (United States)

    Ojala, Elle; Pepper, Joshua; LSST Collaboration

    2018-01-01

    The Large Synoptic Survey Telescope (LSST) will begin operations in 2022, conducting a wide-field, synoptic multiband survey of the southern sky. Some fraction of objects at the bright end of the magnitude regime observed by LSST will overlap with other wide-sky surveys, allowing for calibration and cross-checking between surveys. The LSST is optimized for observations of very faint objects, so much of this data overlap will be comprised of saturated images. This project provides the first in-depth analysis of saturation in LSST images. Using the PhoSim package to create simulated LSST images, we evaluate saturation properties of several types of stars to determine the brightness limitations of LSST. We also collect metadata from many wide-field photometric surveys to provide cross-survey accounting and comparison. Additionally, we evaluate the accuracy of the PhoSim modeling parameters to determine the reliability of the software. These efforts will allow us to determine the expected useable data overlap between bright-end LSST images and faint-end images in other wide-sky surveys. Our next steps are developing methods to extract photometry from saturated images.This material is based upon work supported in part by the National Science Foundation through Cooperative Agreement 1258333 managed by the Association of Universities for Research in Astronomy (AURA), and the Department of Energy under Contract No. DE-AC02-76SF00515 with the SLAC National Accelerator Laboratory. Additional LSST funding comes from private donations, grants to universities, and in-kind support from LSSTC Institutional Members.Thanks to NSF grant PHY-135195 and the 2017 LSSTC Grant Award #2017-UG06 for making this project possible.

  9. Selection effects in the bivariate brightness distribution for spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1986-01-01

    The joint distribution of total luminosity and characteristic surface brightness (the bivariate brightness distribution) is investigated for a complete sample of spiral galaxies in the Virgo cluster. The influence of selection and physical limits of various kinds on the apparent distribution are detailed. While the distribution of surface brightness for bright galaxies may be genuinely fairly narrow, faint galaxies exist right across the (quite small) range of accessible surface brightnesses so no statement can be made about the true extent of the distribution. The lack of high surface brightness bright galaxies in the Virgo sample relative to an overall RC2 sample (mostly field galaxies) supports the contention that the star-formation rate is reduced in the inner region of the cluster for environmental reasons. (author)

  10. Effective instruction for English learners.

    Science.gov (United States)

    Calderón, Margarita; Slavin, Robert; Sánchez, Marta

    2011-01-01

    The fastest-growing student population in U.S. schools today is children of immigrants, half of whom do not speak English fluently and are thus labeled English learners. Although the federal government requires school districts to provide services to English learners, it offers states no policies to follow in identifying, assessing, placing, or instructing them. Margarita Calderón, Robert Slavin, and Marta Sánchez identify the elements of effective instruction and review a variety of successful program models. During 2007-08, more than 5.3 million English learners made up 10.6 percent of the nation's K-12 public school enrollment. Wide and persistent achievement disparities between these English learners and English-proficient students show clearly, say the authors, that schools must address the language, literacy, and academic needs of English learners more effectively. Researchers have fiercely debated the merits of bilingual and English-only reading instruction. In elementary schools, English learners commonly receive thirty minutes of English as a Second Language (ESL) instruction but attend general education classes for the rest of the day, usually with teachers who are unprepared to teach them. Though English learners have strikingly diverse levels of skills, in high school they are typically lumped together, with one teacher to address their widely varying needs. These in-school factors contribute to the achievement disparities. Based on the studies presented here, Calderón, Slavin, and Sánchez assert that the quality of instruction is what matters most in educating English learners. They highlight comprehensive reform models, as well as individual components of these models: school structures and leadership; language and literacy instruction; integration of language, literacy, and content instruction in secondary schools; cooperative learning; professional development; parent and family support teams; tutoring; and monitoring implementation and outcomes

  11. Raman beam combining for laser brightness enhancement

    Science.gov (United States)

    Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

    2015-10-27

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  12. Bright emission lines in new Seyfert galaxies

    International Nuclear Information System (INIS)

    Afanasev, V.L.; Denisiuk, E.K.; Lipovetskii, V.A.; Shapovalova, A.I.

    1983-01-01

    Observational data are given on bright emission lines (H-alpha, H-beta, and forbidden N II, S II, and O III) for 14 recently discovered Seyfert galaxies. The investigated objects can be divided into three groups, which correspond approximately to the first (5 objects), the intermediate (4 objects), and the second (4 objects) Seyfert types. Attention is drawn to the properties of the galaxy Markaryan 1018, which has features of both the first and the second type and is distinguished by the weakness of its emission lines, which is probably due to a gas deficit. 7 references

  13. Implementing learnerships: learner recruitment and selection B ...

    African Journals Online (AJOL)

    Implementing learnerships: learner recruitment and selection B lessons learnt from the KwaZulu-Natal pilot projects. ... 2001 in KwaZulu-Natal, with specific reference to the recruitment and selection of learners. ... AJOL African Journals Online.

  14. Turning university professors into competent learners

    NARCIS (Netherlands)

    Stefanova, Eliza; Ilieva, Miroslava; Nikolova, Nikolina; Stefanov, Krassen

    2008-01-01

    Stefanova, E., Ilieva, M., Nikolova, N, & Stefanov, K. (2008). Turning university professors into competent learners. In H. W. Sligte & R. Koper (Eds.), Proceedings of the 4th TENCompetence Open Workshop. Empowering Learners for Lifelong Competence Development: pedagogical, organisational and

  15. Experiences of learners from informal settlements

    African Journals Online (AJOL)

    Erna Kinsey

    problem is further compounded if educators are not trained to work with learners from ... to locate problems that emerge with the learners themselves rather than within the system ..... "Black students' school success: coping with the burden of ...

  16. Assessing Learner Satisfaction by Simultaneously Measuring Learner Attitude, Motivation, Loyalty and Service Quality in English Academies

    Science.gov (United States)

    Huong, Vu Thi; Casadesus, Marti; Marimon, Frederic

    2017-01-01

    The aims of this study are threefold in their approach to English academy teaching: (i) to assess learner satisfaction, (ii) to assess the impact of satisfaction on loyalty and (iii) to assess the three constructs that we considered to be the antecedents of learner satisfaction: learner motivation, learner attitude and service quality. To collect…

  17. Focus on Form, Learner Uptake and Subsequent Lexical Gains in Learners' Oral Production

    Science.gov (United States)

    Alcon-Soler, Eva

    2009-01-01

    This descriptive study reports findings on the relationship between focus on form, learner uptake and subsequent lexical gains in learners' oral production. The data for the study consisted in 17 45-minute audio-recorded teacher-led conversations, 204 learners' diaries (17 sessions x 12 learners) reporting what they had learned after each…

  18. Next generation diode lasers with enhanced brightness

    Science.gov (United States)

    Ried, S.; Rauch, S.; Irmler, L.; Rikels, J.; Killi, A.; Papastathopoulos, E.; Sarailou, E.; Zimer, H.

    2018-02-01

    High-power diode lasers are nowadays well established manufacturing tools in high power materials processing, mainly for tactile welding, surface treatment and cladding applications. Typical beam parameter products (BPP) of such lasers range from 30 to 50 mm·mrad at several kilowatts of output power. TRUMPF offers a product line of diode lasers to its customers ranging from 150 W up to 6 kW of output power. These diode lasers combine high reliability with small footprint and high efficiency. However, up to now these lasers are limited in brightness due to the commonly used spatial and coarse spectral beam combining techniques. Recently diode lasers with enhanced brightness have been presented by use of dense wavelength multiplexing (DWM). In this paper we report on TRUMPF's diode lasers utilizing DWM. We demonstrate a 2 kW and a 4 kW system ideally suited for fine welding and scanner welding applications. The typical laser efficiency is in the range of 50%. The system offers plug and play exchange of the fiber beam delivery cable, multiple optical outputs and integrated cooling in a very compact package. An advanced control system offers flexible integration in any customer's shop floor environment and includes industry 4.0 capabilities (e.g. condition monitoring and predictive maintenance).

  19. Bright point study. [of solar corona

    Science.gov (United States)

    Tang, F.; Harvey, K.; Bruner, M.; Kent, B.; Antonucci, E.

    1982-01-01

    Transition region and coronal observations of bright points by instruments aboard the Solar Maximum Mission and high resolution photospheric magnetograph observations on September 11, 1980 are presented. A total of 31 bipolar ephemeral regions were found in the photosphere from birth in 9.3 hours of combined magnetograph observations from three observatories. Two of the three ephemeral regions present in the field of view of the Ultraviolet Spectrometer-Polarimeter were observed in the C IV 1548 line. The unobserved ephemeral region was determined to be the shortest-lived (2.5 hr) and lowest in magnetic flux density (13G) of the three regions. The Flat Crystal Spectrometer observed only low level signals in the O VIII 18.969 A line, which were not statistically significant to be positively identified with any of the 16 ephemeral regions detected in the photosphere. In addition, the data indicate that at any given time there lacked a one-to-one correspondence between observable bright points and photospheric ephemeral regions, while more ephemeral regions were observed than their counterparts in the transition region and the corona.

  20. Specialised Translation Dictionaries for Learners

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2010-01-01

    Specialised translation dictionaries for learners are reference tools that can help users with domain discourse in a foreign language in connection with translation. The most common type is the business dictionary covering several more or less related subject fields. However, business dictionaries...... the needs of learners, it is proposed that specialised translation dictionaries should be designed as augmented reference tools. It is argued that electronic and printed dictionaries should include sections or CD-ROMs with syntactic, translation etc. data as well as exercises and illustrative documents...

  1. Brightness and transparency in the early visual cortex.

    Science.gov (United States)

    Salmela, Viljami R; Vanni, Simo

    2013-06-24

    Several psychophysical studies have shown that transparency can have drastic effects on brightness and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for brightness perception. While single cell recordings suggest that surface brightness is represented in the primary visual cortex, the results of functional magnetic resonance imaging (fMRI) studies have been discrepant. In addition, the location of the neural representation of transparency is not yet known. We investigated whether the fMRI responses in areas V1, V2, and V3 correlate with brightness and transparency. To dissociate the blood oxygen level-dependent (BOLD) response to brightness from the response to local border contrast and mean luminance, we used variants of White's brightness illusion, both opaque and transparent, in which luminance increments and decrements cancel each other out. The stimuli consisted of a target surface and a surround. The surround luminance was always sinusoidally modulated at 0.5 Hz to induce brightness modulation to the target. The target luminance was constant or modulated in counterphase to null brightness modulation. The mean signal changes were calculated from the voxels in V1, V2, and V3 corresponding to the retinotopic location of the target surface. The BOLD responses were significantly stronger for modulating brightness than for stimuli with constant brightness. In addition, the responses were stronger for transparent than for opaque stimuli, but there was more individual variation. No interaction between brightness and transparency was found. The results show that the early visual areas V1-V3 are sensitive to surface brightness and transparency and suggest that brightness and transparency are represented separately.

  2. Emotional Intelligence of Self Regulated Learners

    Science.gov (United States)

    Rathore, Ami

    2018-01-01

    The study was conducted on self regulated learners of senior secondary school. The main objectives of the study were to find out significant dimensions of emotional intelligence held by self regulated learners. To compare the emotional intelligence dimensions of self regulated learners, in terms of subject and gender. To find out the relationship…

  3. Buffalo City learners' knowledge of abortion legislation

    African Journals Online (AJOL)

    2014-06-19

    Jun 19, 2014 ... Objectives: This research investigated Grade 11 learners' knowledge of the CTOP Act and ... those learners attending schools formerly designated for African learners during Apartheid .... be performed if, in the opinion of a medical practitioner, ..... of pre-termination of pregnancy counselling to the woman.

  4. High school learners' mental construction during solving ...

    African Journals Online (AJOL)

    Structured activity sheets with three tasks were given to learners; these tasks were done in groups, and the group leaders were interviewed. It was found that learners tended to do well with routine-type questions, implying that they were functioning at an action level. From the interviews it appeared that learners might have ...

  5. An Empirical Assessment of Dropout Rate of Learners at Selected High Schools in King William’s Town, South Africa

    Directory of Open Access Journals (Sweden)

    Wendy Manona

    2015-12-01

    Full Text Available This study investigated and analysed factors responsible for high dropout rate of learners at selected high schools in King William’s Town District, Province of the Eastern Cape. The aim of the study is provide an understanding into inherent problems of early exit of learners in the education sector, which impede the long-term production of professionals with bright future. The main findings of this study revealed that multiple motives, associated with individual characteristics of dropouts and social problems emanating from their family background and influence of the community, prompted learners to dropout. Moreover, learner dropout is inter alia caused by social factors such as lack of resources, the effect of poverty, orphans at school, the distance between the school and the community, drug abuse, pregnancy and HIV and AIDS prevalence in schools, gangsterism and learning barriers. The results of this research suggest that the government should make resources available with regard to scholar transport, school nurses to provide education awareness programmes in relation to early pregnancies, HIV and AIDS infection to improve attendance rate. The Department of Social Development should provide information with regard to benefits available to orphaned learners. The government should ensure sustainable provision of the school nutrition programme to alleviate hunger and poverty. School management should effectively regulate the behaviour of learners to promote discipline in schools so that substance abuse is eliminated.

  6. Very-High-Brightness Picosecond Electron Source

    International Nuclear Information System (INIS)

    Bluem, H.

    2003-01-01

    Bright, RF photocathode electron guns are the source of choice for most high-performance research accelerator applications. Some of these applications are pushing the performance boundaries of the present state-of-the-art guns. Advanced Energy Systems is developing a novel photocathode RF gun that shows excellent promise for extending gun performance. Initial gun simulations with only a short booster accelerator easily break the benchmark emittance of one micron for 1 nC of bunch charge. The pulse length in these simulations is less than 2 ps. It is expected that with more detailed optimization studies, the performance can be further improved. The performance details of the gun will be presented. In addition, we will discuss the present design concept along with the status of the project

  7. New redshifts of bright galaxies. III

    International Nuclear Information System (INIS)

    de Vaucouleurs, G.; de Vaucouleurs, A.; Nieto, J.

    1979-01-01

    Redshifts of 196 bright galaxies, and 2 QSO's are derived from 246 spectrograms obtained from 1972 to 1977 with the Galaxy meter's two-state image tube grism spectrograph attached at the Cassegrain focus of the McDonald Observatory Struve reflector. The reciprocal dispersion in 335 A/mm at Hα and the wavelength range lambdalambda 4500--8000 A. The galaxy redshifts are in the range -28 -1 , but few exceed 5,000 km s -1 . The internal mean errors of the weighted mean velocities range from 22 to 140 km s -1 . Comparisons with other systems of redshifts, particularly the RC2, 21-cm and Sandage systems, indicate a mean systematic error of -35 +- 16 km s -1 , but it is probably variable with V. The external mean error is sigma*=90 km s -1 for velocities V -1 having a mean weight =4.0

  8. Dark Skies, Bright Kids Year 8

    Science.gov (United States)

    Bittle, Lauren E.; Wenger, Trey; Johnson, Kelsey E.; Angell, Dylan; Burkhardt, Andrew; Davis, Blair; Firebaugh, Ariel; Hancock, Danielle; Richardson, Whitney; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; McNair, Shunlante; Prager, Brian; Pryal, Matthew; Troup, Nicholas William

    2017-01-01

    We present activities from the eighth year of Dark Skies Bright Kids (DSBK), an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Over the past seven years, our primary focus has been hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools, and over the past several years, we have partnered with local businesses to host our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows. This past summer we expanded our reach through a new initiative to bring week-long summer day camps to south and southwest Virginia, home to some of the most underserved communities in the commonwealth.

  9. Dark Skies, Bright Kids Year 7

    Science.gov (United States)

    Bittle, Lauren E.; Johnson, Kelsey E.; Borish, H. Jacob; Burkhardt, Andrew; Firebaugh, Ariel; Hancock, Danielle; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; Prager, Brian; Pryal, Matthew; Sokal, Kimberly R.; Troup, Nicholas William; Wenger, Trey

    2016-01-01

    We present updates from our seventh year of operation including new club content, continued assessments, and our fifth annual Star Party. Dark Skies, Bright Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.

  10. Considerations for high-brightness electron sources

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1990-01-01

    Particle accelerators are now used in many areas of physics research and in industrial and medical applications. New uses are being studied to address major societal needs in energy production, materials research, generation of intense beams of radiation at optical and suboptical wavelengths, treatment of various kinds of waste, and so on. Many of these modern applications require a high intensity beam at the desired energy, along with a very good beam quality in terms of the beam confinement, aiming, or focusing. Considerations for ion and electron accelerators are often different, but there are also many commonalties, and in fact, techniques derived for one should perhaps more often be considered for the other as well. We discuss some aspects of high-brightness electron sources here from that point of view. 6 refs

  11. Empowering Learners through Blended Learning

    Science.gov (United States)

    Owston, Ron

    2018-01-01

    Blended learning appears to facilitate learner empowerment more readily than either face-to-face or fully online courses. This contention is supported by a review of literature on the affordances of blended learning that support Thomas and Velthouse's (1990) four conditions of empowerment: choice, meaningfulness, competence, and impact. Blended…

  12. Factors Influencing Learner Permit Duration

    Directory of Open Access Journals (Sweden)

    Johnathon P. Ehsani

    2016-12-01

    Full Text Available An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to “push” and “pull” factors which may encourage or inhibit the process. To examine this question, we recruited a sample of 90 novice drivers (49 females and 41 males, average age of 15.6 years soon after they obtained a learner permit and instrumented their vehicles to collect a range of driving data. Participants completed a series of surveys at recruitment related to factors that may influence licensure timing. Two distinct findings emerged from the time-to-event analysis that tested these push and pull factors in relation to licensure timing. The first can be conceptualized as teens’ motivation to drive (push, reflected in a younger age when obtaining a learner permit and extensive pre-permit driving experience. The second finding was teens’ perceptions of their parents’ knowledge of their activities (pull; a proxy for a parents’ attentiveness to their teens’ lives. Teens who reported higher levels of their parents’ knowledge of their activities took longer to advance to independent driving. These findings suggest time-to-licensure may be related to teens’ internal motivation to drive, and the ability of parents to facilitate or impede early licensure.

  13. Rich Environments for Adult Learners

    Science.gov (United States)

    Bentham, Renee

    2008-01-01

    Unaware of the messages a bare adult learning environment sends and its effect on adult learners, a trainer attends an intensive Reggio Emilia course and learns that the physical environment is the "third teacher"--for adults as well as for children. Using principles of Reggio, she offers suggestions for enhancing adult learning spaces and…

  14. Shifting Power to the Learner

    Science.gov (United States)

    Wolf, Alison

    2010-01-01

    Decades of reform have resulted in a system of further education that treats adults like children, with limited control over the qualifications they choose to pursue. This needs to change. Money must follow learners, not government contracts, and so create a genuinely demand-led system. The author proposes new financial and regulatory structures…

  15. Tweetalige Aanleerderswoordeboek. Bilingual Learner's Dictionary

    African Journals Online (AJOL)

    ate medium for encoding. Correct pronunciation is not guaranteed, because only syllabification and the main stress are indicated in words. Grammatical guidance is also not given to such an extent that Learners will be able to generate correct sentences on their own. The role that con- trastive analysis and error analysis ...

  16. Can You Keep Learners Online?

    Science.gov (United States)

    Zielinski, Dave

    2000-01-01

    Reasons people do not complete online training courses include (1) no incentives, (2) lack of connectedness, (3) learner preference for instructor-led courses, (4) poor course design, (5) "some is enough," and (6) lack of perks. Course delivery must consider three elements: the technology, course design, and the learning environment. (JOW)

  17. Requirements for flexible learner monitoring

    NARCIS (Netherlands)

    Glahn, Christian; Specht, Marcus; Koper, Rob

    2007-01-01

    Glahn, C., Specht, M., & Koper, R. (2007). Requirements for flexible learner monitoring. In T. Navarette, J. Blat & R. Koper (Eds.). Proceedings of the 3rd TENCompetence Open Workshop 'Current Research on IMS Learning Design and Lifelong Competence Development Infrastructures' (pp. 89-96). June,

  18. Preparing Learners for the Future

    Directory of Open Access Journals (Sweden)

    Olga DeJesus

    2017-12-01

    Full Text Available Book review of “Teaching in a Globally Connected World: Preparing Learners for the Future.” Edited by Ervin F. Sparapani and Pamela L. Ross McClain. Lanham, MD: Hamilton Books, 2016. ISBN: 978-0-7618-6814-9

  19. Connected minds technology and today's learners

    CERN Document Server

    Pedrò, Francesc

    2012-01-01

    In all OECD countries, digital media and connectedness are integral to the lives of todays learners. It is often claimed that these learners are ""new millennium learners"", or ""digital natives"", who have different expectations about education. This book contributes to the debate about the effects of technology attachment and connectedness on todays learners, and their expectations about teaching. The book sets out to answer the following questions: Can the claim that todays students are ""new millenium learners"" or ""digital natives be sustained empirically? Is there consistent research evidence demonstrating the effects of technology on cognitive development, social values, and learning expectations? What are the implications for educational policy and practice?

  20. What Is This Thing Called Learner's Lexicography?

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2010-01-01

    Learner lexicography as a research area has attracted increased attention during the past decades, but what is actually the true nature of learner lexicography? This question calls for a complex answer. Learner lexicography has as its objective to develop principles that help practitioners......, namely its functions, data and structures, as this strengthens the basis of learner lexicography because it leads to a proper study and understanding of the competences and needs of learners. Finally, the modern theory of dictionary functions encourages theoretical and practical lexicographers to adopt...

  1. Life-threatening motor vehicle crashes in bright sunlight

    OpenAIRE

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estim...

  2. Study of Three-Dimensional Image Brightness Loss in Stereoscopy

    Directory of Open Access Journals (Sweden)

    Hsing-Cheng Yu

    2015-10-01

    Full Text Available When viewing three-dimensional (3D images, whether in cinemas or on stereoscopic televisions, viewers experience the same problem of image brightness loss. This study aims to investigate image brightness loss in 3D displays, with the primary aim being to quantify the image brightness degradation in the 3D mode. A further aim is to determine the image brightness relationship to the corresponding two-dimensional (2D images in order to adjust the 3D-image brightness values. In addition, the photographic principle is used in this study to measure metering values by capturing 2D and 3D images on television screens. By analyzing these images with statistical product and service solutions (SPSS software, the image brightness values can be estimated using the statistical regression model, which can also indicate the impact of various environmental factors or hardware on the image brightness. In analysis of the experimental results, comparison of the image brightness between 2D and 3D images indicates 60.8% degradation in the 3D image brightness amplitude. The experimental values, from 52.4% to 69.2%, are within the 95% confidence interval

  3. The night sky brightness at McDonald Observatory

    Science.gov (United States)

    Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.

    1975-01-01

    Baseline observations of the night sky brightness in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky brightness are found. Possible causes for these variations are discussed. The largest variation in sky brightness found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow brightness. The data are used to comment on the accuracy of previously published surface photometry of M 81.

  4. Bright environments vision of the Intelligent Lighting Institute (ILI)

    NARCIS (Netherlands)

    Özçelebi, T.

    2014-01-01

    The Bright Environments research program of the Eindhoven University of Technology Intelligent Lighting Institute aims to find new methods of intelligent lighting control and human interaction. We present a summary of the institute’s work on this research field and the research vision of the Bright

  5. Spatially single-mode source of bright squeezed vacuum

    OpenAIRE

    Pérez, A. M.; Iskhakov, T. Sh.; Sharapova, P.; Lemieux, S.; Tikhonova, O. V.; Chekhova, M. V.; Leuchs, G.

    2014-01-01

    Bright squeezed vacuum, a macroscopic nonclassical state of light, can be obtained at the output of a strongly pumped non-seeded traveling-wave optical parametric amplifier (OPA). By constructing the OPA of two consecutive crystals separated by a large distance we make the squeezed vacuum spatially single-mode without a significant decrease in the brightness or squeezing.

  6. The ASAS-SN bright supernova catalogue - III. 2016

    DEFF Research Database (Denmark)

    Holoien, T. W. -S.; Brown, J. S.; Stanek, K. Z.

    2017-01-01

    This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d......This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d...

  7. Analysis of Bright Harvest Remote Analysis for Residential Solar Installations

    Energy Technology Data Exchange (ETDEWEB)

    Nangle, John [National Renewable Energy Lab. (NREL), Golden, CO (United States); Simon, Joseph [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-06-17

    Bright Harvest provides remote shading analysis and design products for residential PV system installers. The National Renewable Energy Laboratory (NREL) through the NREL Commercialization Assistance Program, completed comparative assessments between on-site measurements and remotely calculated values to validate the accuracy of Bright Harvest’s remote shading and power generation.

  8. Dark and bright vortex solitons in electromagnetically induced transparent media

    International Nuclear Information System (INIS)

    Wu Xuan; Xie Xiaotao; Yang Xiaoxue

    2006-01-01

    We show that dark and bright vortex solitons can exist in three-state electromagnetically induced transparent media under some appropriate conditions. We also analyse the stability of the dark and bright vortex solitons. This work may provide other research opportunities in nonlinear optical experiments and may result in a substantial impact on technology

  9. Edge integration and the perception of brightness and darkness

    NARCIS (Netherlands)

    Vladusich, T.; Lucassen, M.P.; Cornelissen, F.W.

    2006-01-01

    How do induced brightness and darkness signals from local and remote surfaces interact to determine the final achromatic color percept of a target surface? An emerging theory of achromatic color perception posits that brightness and darkness percepts are computed by weighting and summing the

  10. Lamp spectrum and spatial brightness at photopic levels

    DEFF Research Database (Denmark)

    Fotios, Steve; Atli, Deniz; Cheal, Chris

    2015-01-01

    Light sources are available in a variety of spectral power distributions (SPDs) and this affects spatial brightness in a manner not predicted by quantities such as illuminance. Tuning light source SPD to better match the sensitivity of visual perception may allow the same spatial brightness but a...

  11. Unskilled Work and Learner Identity

    DEFF Research Database (Denmark)

    Kondrup, Sissel

    2014-01-01

    . The main argument is that participation research must abandon the notion of motivation as an individual attribute and apply a dialectic concept of learner identity acknowledging work-life as a pivotal space for learning and formation of identity. I outline how a work-life-historical approach combining......The paper examines how unskilled work forms conditions for meeting the obligation to position oneself as an educable subject and engage in formal learning activities. Sensitivity to peoples’ work-life-experiences is necessary to understand their orientation toward different learning activities...... a critical theoretical approach inspired by Salling-Olesen’s and Archer’s concepts of identity and concerns can contribute to an understanding of the relationship between work and learner identity. Through narrative work-life interviews I examine how engagement in unskilled work in small and medium sized...

  12. Brightness waves of electroluminescence in ZnO:La electroluminor

    International Nuclear Information System (INIS)

    Bhushan, S.; Pandey, A.N.; Kaza, Balakrishna Rao

    1979-01-01

    A cryostat for the measurement of different luminescent characteristics from liquid N 2 temperature to above has been fabricated. Using this cryostat brightness waves due to sinusoidal excitations for ZnO:La electroluminor (EL) has been studied at different temperatures from -168deg C. Brightness waves for this system consist of two primary peaks during each cycle of excitation. Each primary peak is associated with a secondary peak. This secondary peak at -168deg C exists at the left arm of the primary peak. As the temperature is increased to 18deg C it moves towards the right arm of the primary peak. At an intermediate temperature the secondary peaks are most pronounced. Possible mechanism for these phenomena have been discussed. Temperature dependence of time averaged EL brightness for this system has also been studied and three peaks have been found. The results of brightness waves have also been discussed in the light of temperature dependence of time averaged EL brightness. (auth.)

  13. Intrinsic brightness temperatures of blazar jets at 15 GHz

    Directory of Open Access Journals (Sweden)

    Hovatta Talvikki

    2013-12-01

    Full Text Available We have developed a new Bayesian Markov Chain Monte Carlo method to deconvolve light curves of blazars into individual flares, including proper estimation of the fit errors. We use the method to fit 15GHzlight curves obtained within the OVRO 40-m blazar monitoring program where a large number of AGN have been monitored since 2008 in support of the Fermi Gamma-Ray Space Telescope mission. The time scales obtained from the fitted models are used to calculate the variability brightness temperature of the sources. Additionally, we have calculated brightness temperatures of a sample of these objects using Very Long Baseline Array data from the MOJAVE survey. Combining these two data sets enables us to study the intrinsic brightness temperature distribution in these blazars at 15 GHz. Our preliminary results indicate that the mean intrinsic brightness temperature in a sample of 14 sources is near the equipartition brightness temperature of ~ 1011K.

  14. Intercomparisons of nine sky brightness detectors.

    Science.gov (United States)

    den Outer, Peter; Lolkema, Dorien; Haaima, Marty; van der Hoff, Rene; Spoelstra, Henk; Schmidt, Wim

    2011-01-01

    Nine Sky Quality Meters (SQMs) have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across The Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from -16% to +20%. Intercalibration reduces this to 0.5%, and -7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m(2) on 12 April, and the largest value was 5.94 ± 0.03 mcd/m(2) on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

  15. Dark Skies, Bright Kids Year 9

    Science.gov (United States)

    Burkhardt, Andrew Michael; Matthews, Allison M.; Johnson, Kelsey E.; Avilez, Ian; Beale, Luca; Bittle, Lauren E.; Bordenave, David; Finn, Molly; Firebaugh, Ariel; Hancock, Danielle; Hughes, Paul; Rochford Hayes, Christian; Lewis, Hannah; Linden, Sean; Liss, Sandra; Liu, Mengyao; McNair, Shunlante; Murphy, Edward; Prager, Brian; Pryal, Matthew; Richardson, Whitney; Song, Yiqing; Troup, Nicholas; Villadsen, Jackie; Wenger, Trey V.; Wilson, Robert Forrest

    2018-01-01

    We present updates from the ninth year of operation of Dark Skies, Bright Kids (DSBK) including new club content, continued assessments, and our seventh annual Star Party. DSBK is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Virginia through fun, hands-on activities that introduce basic Astronomy concepts. DSBK’s most fundamental program is an 8-10 week long after-school Astronomy camp at surrounding local elementary schools, where each week introduces new concepts through interactive hands-on activities. Over the past two summers, we have traveled to four rural Virginia locations to bring week-long Astronomy camps to otherwise overlooked elementary school districts. These programs aim to inspire a curiosity for science and include inquiry based activities in topics ranging from the electromagnetic spectrum to the classification and evolution of galaxies. We strive to be self-reflective in our mission to inspire scientific curiosity in the minds of underserved demographics. In this effort, we continually assess the effectiveness of each activity through feedback in student-kept journal pages and observed excitement levels. This self-reflection has initiated the development of new curriculum. In addition, differing from our normal collaboration with local elementary schools, we have found great success partnering with local youth organizations, who may better represent DSBK's target demographics and have infrastructure to support incoming outreach groups.

  16. Enhanced brightness x-ray lasers

    International Nuclear Information System (INIS)

    Wan, A.S.; Cauble, R.C.; Da Silva, L.B.; Moreno, J.C.; Nilsen, J.

    1994-09-01

    We are developing short-pulsed, enhanced-brightness, and coherent x-ray lasers (XRLs) for applications in areas such as plasma imaging. In a traveling wave pump setup the optical laser creating the XRL plasma sweeps along the lasant axis at the same speed as the x-rays. This technique becomes increasingly important as the target length increases and the gain duration shortens. An order of magnitude increase in output energy was measured with vs without traveling wave pump. Using multiple pulse techniques and multilayer mirrors to inject the output of one pulse back into the plasma formed by a later pulse we have begun to develop the x-ray analog of a multi-pass amplifler. The use of multiple pulses separated by as much as 1.6 ns reduces multilayer mirror damage. This injection technique is demonstrated by imaging the near-field emission profiles of the XRL. The addition of multilayer beamsplitter will allow us to effectively produce a soft XRL cavity

  17. Featured Image: Bright Dots in a Sunspot

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    This image of a sunspot, located in in NOAA AR 12227, was captured in December 2014 by the 0.5-meter Solar Optical Telescope on board the Hinode spacecraft. This image was processed by a team of scientists led by Rahul Yadav (Udaipur Solar Observatory, Physical Research Laboratory Dewali, India) in order to examine the properties of umbral dots: transient, bright features observed in the umbral region (the central, darkest part) of a sunspot. By exploring these dots, Yadav and collaborators learned how their properties relate to the large-scale properties of the sunspots in which they form for instance, how do the number, intensities, or filling factors of dots relate to the size of a sunspots umbra? To find out more about the authors results, check out the article below.Sunspot in NOAA AR 11921. Left: umbralpenumbral boundary. Center: the isolated umbra from the sunspot. Right: The umbra with locations of umbral dots indicated by yellow plus signs. [Adapted from Yadav et al. 2018]CitationRahul Yadav et al 2018 ApJ 855 8. doi:10.3847/1538-4357/aaaeba

  18. The Los Alamos high-brightness photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, P.G.

    1991-01-01

    For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven photocathode is placed directly in a high-gradient RF accelerating cavity. A photocathode allows unsurpassed control over the current, and the spatial and temporal profile of the beam. In addition the electrodeless emission'' avoids many of the difficulties associated with multi-electrode guns, i.e. the electrons are accelerated very rapidly to relativistic energies, and there are no electrodes to distort the accelerating fields. For the past two years we have been integrating a photocathode into our existing FEL facility by replacing our thermionic gun and subharmonic bunchers with a high-gradient 1.3 GHz photoinjector. The photoinjector, which is approximately 0.6 m in length, produces 6 MeV, 300 A, 15 ps linac, and accelerated to a final energy of 40 MeV. We have recently begun lasing at wavelengths near 3 {mu}m. 16 refs., 2 figs., 5 tabs.

  19. Modular Zero Energy. BrightBuilt Home

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.; Butterfield, Karla [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  20. Intercomparisons of Nine Sky Brightness Detectors

    Directory of Open Access Journals (Sweden)

    Henk Spoelstra

    2011-10-01

    Full Text Available Nine Sky Quality Meters (SQMs have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across the Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from −16% to +20%. Intercalibration reduces this to 0.5%, and −7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m2 on 12 April, and the largest value was 5.94 ± 0.03 mcd/m2 on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

  1. Dark Skies, Bright Kids Year 6

    Science.gov (United States)

    Liss, Sandra; Troup, Nicholas William; Johnson, Kelsey E.; Barcos-Munoz, Loreto D.; Beaton, Rachael; Bittle, Lauren; Borish, Henry J.; Burkhardt, Andrew; Corby, Joanna; Dean, Janice; Hancock, Danielle; King, Jennie; Prager, Brian; Romero, Charles; Sokal, Kimberly R.; Stierwalt, Sabrina; Wenger, Trey; Zucker, Catherine

    2015-01-01

    Now entering our sixth year of operation, Dark Skies, Bright Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in central Virginia through fun, hands-on activities that introduce basic Astronomy concepts beyond Virginia's Standards of Learning. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.DSBK has amassed over 15,000 contact hours since 2009 and we continue to broaden our impact. One important step we have taken in the past year is to establish a graduate student led assessment program to identify and implement directed learning goals for DSBK outreach. The collection of student workbooks, observations, and volunteer surveys indicates broad scale success for the program both in terms of student learning and their perception of science. The data also reveal opportunities to improve our organizational and educational practices to maximize student achievement and overall volunteer satisfaction for DSBK's future clubs and outreach endeavors.

  2. High Ability and Learner Characteristics

    Directory of Open Access Journals (Sweden)

    Huda Hindal

    2013-01-01

    Full Text Available The outstandingly able learner has been conceptualised, in terms of test and examination performance, as the learner showing superior academic performance which is markedly better than that of peers and in ways regarded as of value by wider society. In Kuwait, such superior examination performance leads to a classification regarded as being ‘gifted’. This study looks at the inter-correlations between performance in various subjects in examinations and then considers how examination performance correlates with measures of working memory capacity, extent of field dependency, extent of divergency and visual-spatial abilities. A very large sample of grade 7 Kuwaiti students (aged ~13 was involved, the sample being selected in such a way that it contained a high proportion of those regarded as ‘gifted’ under the procedures used in Kuwait. While specific learner characteristics have been related to examination performance, this study brings four different characteristics together to gain a picture of the way these characteristics may be seen in those who perform extremely well in examinations. Principal components analysis using varimax rotation, was used to look at the examination data and one factor accounted for 87% of the variance. A consideration of the examination papers led to the conclusion that the national examinations tested only recall-recognition. It was also found that those who performed best in all six subjects tended to be those who are highly divergent and strongly visual-spatial as well as those tending to have higher working memory capacities and being more field independent. The inter-correlations between the various learner characteristics are explained in terms of the way the brain is known to process information. The implications of the findings for assessment and for the way high ability is considered are discussed.

  3. Literacy for all young learners

    CERN Document Server

    Jalongo, Mary Renck

    2015-01-01

    Literacy for All Young Learners offers 65 strategies to support literacy learning with children from preschool through the third grade. Each strategy is designed to be simple to use with all of the children in your classroom-from the not-yet-readers to the fluent readers-and each strategy is tied to the Common Core State Standards for kindergarten through third grade.

  4. Learner discipline: An Australian perspective

    Directory of Open Access Journals (Sweden)

    D. Stewart

    2004-07-01

    Full Text Available Australian schools by and large are safe schools. Nonetheless discipline problems do exist – including bullying behaviour. For this kind of problem schools should have management policies in place. As traditional behaviour-management practices – including corporal punishment – are largely prohibited in Australian schools, contemporary practices centre on management through supportive school programmes, including appropriate curricula and school-support structures. This article supports the belief that measures such as the exclusion of misbehaving learners should be treated with caution. Measures such as this might not reflect accepted international principles and practices and should only be exercised in the most extreme circumstances. The article also supports the view that it is part of the school’s role to ensure that all learners are aware of the reality that while they have rights, they also have corresponding responsibilities. This awareness is more likely to be achieved in a supportive school culture where each learner is recognised as having unique qualities that can mature and grow in an appropriate learning environment.

  5. Learner-to-learner visual acuity screening: A solution for early ...

    African Journals Online (AJOL)

    The National School Health Policy guidelines (2002) stipulate that primary school learners should have their vision, speech, hearing, mental health, teeth, ... This project created greater awareness among learners, parents and teachers ...

  6. Dark Skies, Bright Kids! Year 3

    Science.gov (United States)

    Whelan, David G.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R. L.; Borish, J.; Corby, J. F.; Dorsey, G.; Gugliucci, N. E.; Prager, B. J.; Ries, P. A.; Romero, C. E.; Sokal, K. R.; Tang, X.; Walker, L. M.; Yang, A. J.; Zasowski, G.

    2012-01-01

    Dark Skies, Bright Kids! (DSBK) is a program that brings astronomy education to elementary schools throughout central Virginia. In a relaxed, out-of-classroom atmosphere, we are able to foster the innate curiosity that young students have about science and the world around them. We target schools that are under-served due to their rural locale or special needs students, demonstrating that science is a fun and creative process to a segment of the population that might not otherwise be exposed to astronomy. Families are included in the learning experience during semi-annual `star parties'. Since last January, we have expanded the breadth and depth of our educational capabilities. We have developed new programs for use in our digital planetarium. We held the first Central Virginia Star Party, providing an atmosphere where local children from multiple schools were able to share their love for astronomy. Local government and University officials were also invited so that they could experience our focused science outreach. Most recently, we have become part of Ivy Creek School's Club Day activities, bringing our program to a new segment of the elementary school system in Albemarle County: those that have `low-incidence' disabilities, requiring special attention. We continue to develop a curriculum for after-school programs that functions as either a series of one-time activities or several months of focused outreach at one school. Many of these activities are provided on our website, http://www.astro.virginia.edu/dsbk/, for the wider astronomical community, including the new planetarium work. We have extended our book project to include two bilingual astronomy books called `Snapshots of the Universe,' one in Spanish and English, the other in French and English. These books introduce young people to some of the many wonders of the Universe through art and captions developed by DSBK volunteers.

  7. Bright field electron microscopy of biological specimens

    International Nuclear Information System (INIS)

    Johansen, B.V.

    1976-01-01

    A preirradiation procedure is described which preserves negatively stained morphological features in bright field electron micrographs to a resolution of about 1.2 nm. Prior to microscopy the pre-irradiation dose (1.6 x 10 -3 C cm -2 ) is given at low electron optical magnification at five different areas on the grid (the centre plus four 'corners'). This pre-irradiation can be measured either with a Faraday cage or through controlled exposure-developing conditions. Uranyl formate stained T2 bacteriophages and stacked disk aggregates of Tobacco Mosaic Virus (TMV) protein served as test objects. A comparative study was performed on specimens using either the pre-irradiation procedure or direct irradiation by the 'minimum beam exposure' technique. Changes in the electron diffraction pattern of the stain-protein complex and the disappearance of certain morphological features in the specimens were both used in order to compare the pre-irradiation method with the direct exposure technique. After identical electron exposures the pre-irradiation approach gave a far better preservation of specimen morphology. Consequently this procedure gives the microscopist more time to select and focus appropriate areas for imaging before deteriorations take place. The investigation also suggested that microscopy should be carried out between 60,000 and 100,000 times magnification. Within this magnification range, it is possible to take advantage of the phase contrast transfer characteristics of the objective lens while the electron load on the object is kept at a moderate level. Using the pre-irradiation procedure special features of the T2 bacteriophage morphology could be established. (author)

  8. Dark Skies, Bright Kids! Year 4

    Science.gov (United States)

    Sokal, Kimberly R.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Borish, J.; Crawford, S. B.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Jackson, L.; Liss, S.; Oza, A.; Peacock, S.; Prager, B.; Romero, C.; Sivakoff, G. R.; Walker, L.; Whelan, D. G.; Zucker, C.

    2013-01-01

    Aiming to engage young children's natural excitement and curiosity, the outreach group Dark Skies, Bright Kids (DSBK) brings a hands-on approach to astronomy to elementary schools in Virginia. We hope to enhance children's view and understanding of science while exploring the Universe using fun activities. DSBK focuses on rural and underserved schools in Albemarle County and offers a semester-long astronomy club for third through fifth grade students. We believe regular interactions foster personal relationships between students and volunteers that encourage a life-long interest in science. In our fourth year of hosting clubs, we returned to Ivy Creek Elementary School, where we saw wonderful responses from a special group of students with `low-incidence' disabilities. DSBK has grown to realize a broader reach beyond local astronomy clubs; we hope to ignite a spark of interest in astronomy and science more widely- in more children, their families, and their teachers. We also hosted the Second Annual Central Virginia Star Party with an open invitation to the community to encourage families to enjoy astronomy together. Throughout the year, DSBK now holds 'one-off' programs (akin to astronomy field days) for elementary schools and children's groups throughout Virginia. Furthermore, we are in the final stages of a project to create two bilingual astronomy books called "Snapshots of the Universe", in Spanish and French with English translations. This art book will be made available online and we are working to get a copy in every elementary school in the state. DSBK has begun to reach out to elementary school teachers in order to provide them with useful and engaging classroom material. We have adapted our volunteer-created activities into useful and ready-to-use lessons, available online. After improvements based on research through interactions and feedback from teachers, we have explicitly identified the learning goals in terms of Virginia's Standards of Learning

  9. Why Do Learners Choose Online Learning: The Learners' Voices

    Science.gov (United States)

    Ilgaz, Hale; Gulbahar, Yasemin

    2017-01-01

    Offering many advantages to adult learners, e-Learning is now being recognized--and preferred--by more and more people, resulting in an increased number of distance learners in recent years. Numerous research studies focus on learner preferences for online learning, with most converging around the individual characteristics and differences, if not…

  10. Quantitative Brightness Analysis of Fluorescence Intensity Fluctuations in E. Coli.

    Directory of Open Access Journals (Sweden)

    Kwang-Ho Hur

    Full Text Available The brightness measured by fluorescence fluctuation spectroscopy specifies the average stoichiometry of a labeled protein in a sample. Here we extended brightness analysis, which has been mainly applied in eukaryotic cells, to prokaryotic cells with E. coli serving as a model system. The small size of the E. coli cell introduces unique challenges for applying brightness analysis that are addressed in this work. Photobleaching leads to a depletion of fluorophores and a reduction of the brightness of protein complexes. In addition, the E. coli cell and the point spread function of the instrument only partially overlap, which influences intensity fluctuations. To address these challenges we developed MSQ analysis, which is based on the mean Q-value of segmented photon count data, and combined it with the analysis of axial scans through the E. coli cell. The MSQ method recovers brightness, concentration, and diffusion time of soluble proteins in E. coli. We applied MSQ to measure the brightness of EGFP in E. coli and compared it to solution measurements. We further used MSQ analysis to determine the oligomeric state of nuclear transport factor 2 labeled with EGFP expressed in E. coli cells. The results obtained demonstrate the feasibility of quantifying the stoichiometry of proteins by brightness analysis in a prokaryotic cell.

  11. NIGHT SKY BRIGHTNESS ABOVE ZAGREB 2012.-2017.

    Directory of Open Access Journals (Sweden)

    Željko Andreić

    2018-01-01

    Full Text Available The night sky brightness at the RGN site (near the centre of Zagreb, Croatia was monitored form January 2012. to December 2017. The gathered data show that the average night sky brightness in this period did not change significantly, apart from differences caused by yearly variations in meteorological parameters. The nightly minima, maxima and mean values of the sky brightness do change considerably due to changes in meteorological conditions, often being between 2 and 3 magnitudes. The seasonal probability curves and histograms are constructed and are used to obtain additional information on the light pollution at the RGN site. They reveal that the night sky brightness clutters around two peaks, at about 15.0 mag/arcsec2 and at about 18.2 mag/arcsec2. The tendency to slightly lower brightness values in spring and summer can also be seen in the data. Two peaks correspond to cloudy and clear nights respectively, the difference in brightness between them being about 3 magnitudes. A crude clear/cloudy criterion can be defined too: the minimum between two peaks is around 16.7 mag/arcsec2. The brightness values smaller than thisare attributed to clear nights and vice-versa. Comparison with Vienna and Hong-Kong indicates that the light pollution of Zagreb is a few times larger.

  12. Quadrature measurements of a bright squeezed state via sideband swapping

    DEFF Research Database (Denmark)

    Schneider, J.; Glockl, O.; Leuchs, G.

    2009-01-01

    The measurement of an arbitrary quadrature of a bright quantum state of light is a commonly requested action in many quantum information protocols, but it is experimentally challenging with previously proposed schemes. We suggest that the quadrature be measured at a specific sideband frequency...... of a bright quantum state by transferring the sideband modes under interrogation to a vacuum state and subsequently measuring the quadrature via homodyne detection. The scheme is implemented experimentally, and it is successfully tested with a bright squeezed state of light....

  13. Learner-Generated Noticing Behavior by Novice Learners: Tracing the Effects of Learners' L1 on Their Emerging L2

    Science.gov (United States)

    Park, Eun Sung

    2013-01-01

    This study examines novice learners' self-generated input noticing approaches and strategies. It is motivated by previous research on input enhancement which yielded insights that learners are naturally prone to notice certain aspects of L2 input on their own without any external means to channel their attention. Two L1 groups (Japanese and…

  14. Learner Satisfaction in Online Learning: An Analysis of the Perceived Impact of Learner-Social Media and Learner-Instructor Interaction

    Science.gov (United States)

    Andersen, Jeffery C.

    2013-01-01

    The purpose of this study was to determine the relationships between general course satisfaction, learner-instructor interaction, and the learner-social media interaction scores of participants. This study used an online survey with 60 questions to gather the participants' demographic data, learner-instructor interaction data, learner-social…

  15. Elu algab teispool naudinguprintsiipi / Anita Vanaga

    Index Scriptorium Estoniae

    Vanaga, Anita

    2009-01-01

    Läti kunstniku Ilmars Blumbergsi näitus "Vihma tibutab, vihma tibutab! Vihma tibutab! Ostke mõni pilt, ostke mõni pilt! Ostke mõni pilt! Voldemars Irbe elu, töö ja surm" Tallinna Kunstihoone Galeriis 31. maini. Näitus on avatud rahvusvahelise joonistustriennaali "Manu propria" raames

  16. Monolingual and Bilingual Learners' Dictionaries*

    Directory of Open Access Journals (Sweden)

    Rufus H. Gouws

    2011-10-01

    Full Text Available

    Abstract: When deciding on the best learners' dictionary for a specific user and a specificsituation of usage one often has to make a choice between a monolingual and a bilingual learners'dictionary. This article discusses some aspects of the user-driven approach so prevalent in moderndaylexicographic thought, focuses broadly on dictionary typology and takes a closer look at monolingualand bilingual learners' dictionaries. Some problems users experience when learning a newlanguage, e.g. language distortion and problems related to the phenomenon of false friends, especiallyin closely related languages, are mentioned. It is indicated that a typological hybrid dictionarycould assist certain users. The importance of an unambiguous identification of the relevantlexicographic functions is emphasised and the notions of function condensation and function mergingare introduced. It is shown that the typological choice should be determined by a function-basedapproach to dictionary usage.

    Keywords: BILINGUAL DICTIONARY, FALSE FRIENDS, FUNCTION CONDENSATION,FUNCTION MERGING, GENUINE PURPOSE, LEARNERS' DICTIONARY, LEXICOGRAPHICFUNCTIONS, MONOLINGUAL DICTIONARY, TEXT PRODUCTION, TEXT RECEPTION,TYPOLOGICAL HYBRID, TYPOLOGY.

    Opsomming: Eentalige en tweetalige aanleerderwoordeboeke. Wanneerbesluit moet word oor die beste aanleerderwoordeboek vir 'n spesifieke gebruiker en 'n spesifiekegebruiksituasie moet daar dikwels gekies word tussen 'n eentalige en 'n tweetalige aanleerderwoordeboek.Hierdie artikel bespreek bepaalde aspekte van die gebruikersgedrewe benaderingwat kenmerkend is van die moderne leksikografiese denke, fokus breedweg op woordeboektipologieen gee in meer besonderhede aandag aan sekere aspekte van eentalige en tweetalige aanleerderwoordeboeke.Bepaalde probleme wat gebruikers ervaar by die aanleer van 'n vreemde taal,bv. taalversteuring en probleme verwant aan die verskynsel van valse vriende, veral in nou verwantetale, kry aandag

  17. Legal Translation Dictionaries for Learners

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2010-01-01

    in conditional clauses. When translating into languages not allowing such structures, for instance, English and French, learners need their legal translation dictionaries to help them with both the legal terms and the syntactic structures. The uses of textual conventions that characterise the legal genre vary....... Lexicographers should therefore design their dictionaries so that they contain intra-lingual or contrastive descriptions of the relevant genre conventions. As illustrated in Nielsen (2000) whether the best solution is to retain the genre conventions found in the SL text or to adopt the conventions used in TL...

  18. Identifying Bright X-Ray Beasts

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Ultraluminous X-ray sources (ULXs) are astronomical sources of X-rays that, while dimmer than active galactic nuclei, are nonetheless brighter than any known stellar process. What are these beasts and why do they shine so brightly?Exceeding the LimitFirst discovered in the 1980s, ULXs are rare sources that have nonetheless been found in all types of galaxies. Though the bright X-ray radiation seems likely to be coming from compact objects accreting gas, theres a problem with this theory: ULXs outshine the Eddington luminosity for stellar-mass compact objects. This means that a stellar-mass object couldnt emit this much radiation isotropically without blowing itself apart.There are two alternative explanations commonly proposed for ULXs:Rather than being accreting stellar-mass compact objects, they are accreting intermediate-mass black holes. A hypothetical black hole of 100 solar masses or more would have a much higher Eddington luminosity than a stellar-mass black hole, making the luminosities that we observe from ULXs feasible.An example of one of the common routes the authors find for a binary system to become a ULX. In this case, the binary begins as two main sequence stars. As one star evolves off the main sequence, the binary undergoes a common envelope phase and a stage of mass transfer. The star ends its life as a supernova, and the resulting neutron star then accretes matter from the main sequence star as a ULX. [Wiktorowicz et al. 2017]They are ordinary X-ray binaries (a stellar-mass compact object accreting matter from a companion star), but they are undergoing a short phase of extreme accretion. During this time, their emission is beamed into jets, making them appear brighter than the Eddington luminosity.Clues from a New DiscoveryA few years ago, a new discovery shed some light on ULXs: M82 X-2, a pulsing ULX. Two more pulsing ULXs have been discovered since then, demonstrating that at least some ULXs contain pulsars i.e., neutron stars as the

  19. A new perspective on the infrared brightness temperature ...

    Indian Academy of Sciences (India)

    CEAWMT), ... temperatures clearly discriminates the cloud pixels of deep convective and ... utilized in the modelling of the histogram of infrared brightness temperature of deep convective and ..... Henderson-Sellers A 1978 Surface type and its effect.

  20. Operational Bright-Band Snow Level Detection Using Doppler Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A method to detect the bright-band snow level from radar reflectivity and Doppler vertical velocity data collection with an atmospheric profiling Doppler radar. The...

  1. Visible Color and Photometry of Bright Materials on Vesta

    Science.gov (United States)

    Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.

    2012-01-01

    The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its brightness and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently bright materials on Vesta in order to study their origin. The global distribution and the spectroscopy of bright materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan bright materials are reported in [5].

  2. Nimbus-5 ESMR Polar Gridded Brightness Temperatures, Version 2

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR) data set consists of gridded brightness temperature arrays for the Arctic and Antarctic, spanning 11...

  3. Identifying Successful Learners from Interaction Behaviour

    Science.gov (United States)

    McCuaig, Judi; Baldwin, Julia

    2012-01-01

    The interaction behaviours of successful, high-achieving learners when using a Learning Management System (LMS) are different than the behaviours of learners who are having more difficulty mastering the course material. This paper explores the idea that conventional Learning Management Systems can exploit data mining techniques to predict the…

  4. Scaffolding Learner Autonomy in Online University Courses

    Science.gov (United States)

    Ribbe, Elisa; Bezanilla, María José

    2013-01-01

    This paper deals with the question in what ways teachers and course designers can support the development and exertion of learner autonomy among online university students. It advocates that a greater attention to learner autonomy could help more students to complete their course successfully and thus contribute the decrease of the high dropout…

  5. Language, Learners and Levels. Progression and Variation

    NARCIS (Netherlands)

    Haan, P.J.M. de; Vries, C.M. de; Vuuren, S. van

    2017-01-01

    Learner Corpus Research (LCR) is a vibrant discipline, which combines methodological rigour in the analysis of authentic learner data with a focus on practical pedagogical application. Following earlier successful conferences in Louvain and Bergen, the third LCR conference, hosted by Radboud

  6. "Harry Potter" and the English Language Learner.

    Science.gov (United States)

    Coatney, Kathy

    2001-01-01

    Describes one teacher's success with using "Harry Potter" in a program to teach elementary school English language learners. Provides comprehension strategies incorporated to help learners understand the story. Highlights the importance of creating a classroom environment with a low level of anxiety, the implications of the program, and the value…

  7. English Language Learners in a Digital Classroom

    Science.gov (United States)

    Prince, Johanna

    2017-01-01

    English language learners (ELLs) experience linguistic, cultural, and cognitive shifts that can be challenging and at times lead to isolation for ELLs. While education technology may be an instructional resource and engage learners, devices alone do not shift instructional practices or lead to student gains. This case study was performed at an…

  8. Promising Instructional Practices for English Language Learners

    Science.gov (United States)

    Prince, Johanna

    2018-01-01

    Aim/Purpose: The purpose of this exploratory case study was to understand how teachers, working with English Language Learners (ELLs), expanded their knowledge and instructional practices as they implemented a one-to-one iPad® program. Background: English Language Learners experience linguistic, cultural, and cognitive shifts that can be…

  9. An Empirical Investigation into Nigerian ESL Learners ...

    African Journals Online (AJOL)

    General observations indicate that ESL learners in Nigeria tend to manifest fear and anxiety in grammar classes, which could influence their performance negatively or positively. This study examines empirically some of the reasons for some ESL learners' apprehension of grammar classes. The data for the study were ...

  10. Multidimensional Learner Model In Intelligent Learning System

    Science.gov (United States)

    Deliyska, B.; Rozeva, A.

    2009-11-01

    The learner model in an intelligent learning system (ILS) has to ensure the personalization (individualization) and the adaptability of e-learning in an online learner-centered environment. ILS is a distributed e-learning system whose modules can be independent and located in different nodes (servers) on the Web. This kind of e-learning is achieved through the resources of the Semantic Web and is designed and developed around a course, group of courses or specialty. An essential part of ILS is learner model database which contains structured data about learner profile and temporal status in the learning process of one or more courses. In the paper a learner model position in ILS is considered and a relational database is designed from learner's domain ontology. Multidimensional modeling agent for the source database is designed and resultant learner data cube is presented. Agent's modules are proposed with corresponding algorithms and procedures. Multidimensional (OLAP) analysis guidelines on the resultant learner module for designing dynamic learning strategy have been highlighted.

  11. The Indonesian EFL Learners' Motivation in Reading

    Science.gov (United States)

    Salikin, Hairus; Bin-Tahir, Saidna Zulfiqar; Kusumaningputri, Reni; Yuliandari, Dian Puji

    2017-01-01

    The motivation will drive the EFL learners to be successful in reading. This study examined the Indonesian EFL learners' motivation in reading activity based on Deci and Ryans' theory of motivation including intrinsic and extrinsic. This study employed mixed-method design. The data obtained by distributing questionnaire and arranging the group…

  12. ICT Usage by Distance Learners in India

    Science.gov (United States)

    Awadhiya, Ashish Kumar; Gowthaman, K.

    2014-01-01

    Open Universities across the world are embracing ICT based teaching and learning process to disseminate quality education to their learners spread across the globe. In India availability and access of ICT and learner characteristics are uneven and vary from state to state. Hence it is important to establish the facts about ICT access among…

  13. Assessment concessions for learners with impairments

    African Journals Online (AJOL)

    Erna Kinsey

    Vol 25(3)185–189. Assessment ... We focus on the use of different types of assessment concessions as a basis for the development of .... to facilitate the development of meaning. .... changing the vocabulary in the test to make them more accessible to learners. .... For learners who are not able to produce recognizable words.

  14. Pairing the Adult Learner and Boutique Wineries

    Science.gov (United States)

    Holyoke, Laura; Heath-Simpson, Delta

    2013-01-01

    This study explored connections between adult learners and their experiences in the context of small boutique wineries operating in the start-up phase of the organizational life cycle. The research objective was to gain insight regarding the pairing of adult learners with the entering of a specialty industry. Fourteen individuals from four…

  15. Vocabulary Growth of the Advanced EFL Learner

    Science.gov (United States)

    Ozturk, Meral

    2015-01-01

    This article reports the results of two studies on the vocabulary growth of advanced learners of English as a foreign language in an English-medium degree programme. Growth in learners' written receptive and productive vocabularies was investigated in one cross-sectional and one longitudinal study over three years. The effect of word frequency on…

  16. Technologies for Learner-Centered Feedback

    Science.gov (United States)

    Costello, Jane; Crane, Daph

    2013-01-01

    As the number, type, and use of technologies to support learning increases, so do the opportunities for using these technologies for feedback. Learner-centered feedback is a core to the teaching-learning process. It is related to assessment in describing how learners perform in their learning, their gain in knowledge, skills, and attitudes.…

  17. Analytically derived conversion of spectral band radiance to brightness temperature

    Energy Technology Data Exchange (ETDEWEB)

    Berk, Alexander [Spectral Sciences, Inc., 44th Avenue, Burlington, MA 01803 (United States)], E-mail: lex@spectral.com

    2008-05-15

    Simple analytic expressions for brightness temperature have been derived in terms of band response function spectral moments. Accuracy measures are also derived. Application of these formulas to GOES-12 Sounder thermal infrared bands produces brightness temperature residuals between -5.0 and 2.5 mK for a 150-400 K temperature range. The magnitude of residuals for the five ASTER Radiometer thermal infrared bands over the same temperature range is less than 0.22 mK.

  18. Researching transformative learning spaces through learners' stories

    DEFF Research Database (Denmark)

    Maslo, Elina

    spaces, learning to learn through languages, learners´ stories, qualitative research method Methodology or Methods/Research Instruments or Sources Used A number of semi structured qualitative interviews have been conducted with three learners of Danish as second language. The language learners...... in the paper is on the research process and methodological tools. The goal of this paper is to show, that learners´ stories have a huge potential in researching learning processes. References Benson, P. & D. Nunan (2004). Lerners´ stories. Difference and Diversity in Language Learning. Cambridge University...... to use learners´ stories as a research methodology in the field of learning in general and language learning in particular....

  19. The effect of bright lines in environmental risk communication

    International Nuclear Information System (INIS)

    Wilson, K.N.; Desvousges, W.H.; Smith, K.V.; Payne, J.

    1993-01-01

    Bright lines in environmental risk communication refer to the specific levels at which an environmental risk becomes a serious health threat and action should be taken to mitigate its effects. This study examined the effect of ''bright lines'' in risk communication by emphasizing the radon exposure threshold level of 4 picocuries per liter. Specifically, the authors developed a computer-assisted interview containing bright-line versions of risk information. The bright-line version contained a range of possible radon levels, the corresponding number of estimated lung cancer cases, the relative health risk from radon compared to other health risks, and the EPA guidelines for mitigating levels above 4 picocuries in the home. The non-bright line version was identical to the bright-line version, except it did not include the EPA's mitigation recommendations. Effect measures included respondents' change in perceived risk after reading their materials, intended testing behavior, and advice to their neighbor for a specified radon level either above or below the 4 picocury threshold level. This paper discusses broader policy implications for designing effective risk communication programs

  20. Learner Corpora without Error Tagging

    Directory of Open Access Journals (Sweden)

    Rastelli, Stefano

    2009-01-01

    Full Text Available The article explores the possibility of adopting a form-to-function perspective when annotating learner corpora in order to get deeper insights about systematic features of interlanguage. A split between forms and functions (or categories is desirable in order to avoid the "comparative fallacy" and because – especially in basic varieties – forms may precede functions (e.g., what resembles to a "noun" might have a different function or a function may show up in unexpected forms. In the computer-aided error analysis tradition, all items produced by learners are traced to a grid of error tags which is based on the categories of the target language. Differently, we believe it is possible to record and make retrievable both words and sequence of characters independently from their functional-grammatical label in the target language. For this purpose at the University of Pavia we adapted a probabilistic POS tagger designed for L1 on L2 data. Despite the criticism that this operation can raise, we found that it is better to work with "virtual categories" rather than with errors. The article outlines the theoretical background of the project and shows some examples in which some potential of SLA-oriented (non error-based tagging will be possibly made clearer.

  1. Hábitos alimentarios y su relación con el estado nutricional de los estudiantes del V ciclo (5° y 6° grado) del nivel primaria de la Institución Educativa Nº 106 Abraham Valdelomar, Santa Anita - 2014

    OpenAIRE

    Vicente Huamán, Ibis Julia

    2015-01-01

    En el presente trabajo de investigación se planteó el problema ¿Cuál es la relación entre los hábitos alimentarios y el estado nutricional de los alumnos del V Ciclo (5º y 6º grado) de primaria de la Institución Educativa. Nº 106 Abraham Valdelomar del distrito de Santa Anita – 2014? Para lo cual se seleccionó una muestra probabilística constituida por 148 estudiantes en quienes se recogió las medidas antropométricas de peso y talla con las cuales se encontró el Índice de Masa Corporal. Los r...

  2. Color and emotion: effects of hue, saturation, and brightness.

    Science.gov (United States)

    Wilms, Lisa; Oberfeld, Daniel

    2017-06-13

    Previous studies on emotional effects of color often failed to control all the three perceptual dimensions of color: hue, saturation, and brightness. Here, we presented a three-dimensional space of chromatic colors by independently varying hue (blue, green, red), saturation (low, medium, high), and brightness (dark, medium, bright) in a factorial design. The 27 chromatic colors, plus 3 brightness-matched achromatic colors, were presented via an LED display. Participants (N = 62) viewed each color for 30 s and then rated their current emotional state (valence and arousal). Skin conductance and heart rate were measured continuously. The emotion ratings showed that saturated and bright colors were associated with higher arousal. The hue also had a significant effect on arousal, which increased from blue and green to red. The ratings of valence were the highest for saturated and bright colors, and also depended on the hue. Several interaction effects of the three color dimensions were observed for both arousal and valence. For instance, the valence ratings were higher for blue than for the remaining hues, but only for highly saturated colors. Saturated and bright colors caused significantly stronger skin conductance responses. Achromatic colors resulted in a short-term deceleration in the heart rate, while chromatic colors caused an acceleration. The results confirm that color stimuli have effects on the emotional state of the observer. These effects are not only determined by the hue of a color, as is often assumed, but by all the three color dimensions as well as their interactions.

  3. Beam brightness calculation for analytical and empirical distribution functions

    International Nuclear Information System (INIS)

    Myers, T.J.; Boulais, K.A.; O, Y.S.; Rhee, M.J.

    1992-01-01

    The beam brightness, a figure of merit for a beam quality useful for high-current low-emittance beams, was introduced by van Steenbergen as B = I/V 4 , where I is the beam current and V 4 is the hypervolume in the four-dimensional trace space occupied by the beam particles. Customarily, the brightness is expressed in terms of the product of emittances ε x ε y as B = ηI/(π 2 ε x ε y ), where η is a form factor of order unity which depends on the precise definition of emittance and hypervolume. Recently, a refined definition of the beam brightness based on the arithmetic mean value defined in statistics is proposed. The beam brightness is defined as B triple-bond 4 > = I -1 ∫ ρ 4 2 dxdydx'dy', where I is the beam current given by I ∫ ρ 4 dxdydx'dy'. Note that in this definition, neither the hypervolume V 4 nor the emittance, are explicitly used; the brightness is determined solely by the distribution function. Brightnesses are unambiguously calculated and expressed analytically in terms of the respective beam current and effective emittance for a few commonly used distribution functions, including Maxwellian and water-bag distributions. Other distributions of arbitrary shape frequently encountered in actual experiments are treated numerically. The resulting brightnesses are expressed in the form B = ηI/(π 2 ε x ε y ), and η is found to be weakly dependent on the form of velocity distribution as well as spatial distribution

  4. ICT USAGE BY DISTANCE LEARNERS IN INDIA

    Directory of Open Access Journals (Sweden)

    Ashish Kumar AWADHIYA

    2014-07-01

    Full Text Available Open Universities across the world are embracing ICT based teaching and learning process to disseminate quality education to their learners spread across the globe. In India availability and access of ICT and learner characteristics are uneven and vary from state to state. Hence it is important to establish the facts about ICT access among learners, their ICT usage patterns and their readiness to use ICT for educational purpose. In view of this, a study was conducted with the objective to find out the access level of ICT among distance learners. The analysis indicates that maximum learners have desktop/laptops and most of them are accessing internet very frequently from their home. The analysis also indicates that maximum respondents are browsing social networking sites followed by educational and e-mail service providing websites. Findings suggest that there is a need to generate ICT based tutorials complemented with social networking tools and mobile applications. Study also shows that learners are equipped with mobile phones and they are browsing internet through it and also availing support services offered by the university. Hence possibility of integrating mobile phone services may be used for providing learner support services and content delivery.

  5. Improving Learner Handovers in Medical Education.

    Science.gov (United States)

    Warm, Eric J; Englander, Robert; Pereira, Anne; Barach, Paul

    2017-07-01

    Multiple studies have demonstrated that the information included in the Medical Student Performance Evaluation fails to reliably predict medical students' future performance. This faulty transfer of information can lead to harm when poorly prepared students fail out of residency or, worse, are shuttled through the medical education system without an honest accounting of their performance. Such poor learner handovers likely arise from two root causes: (1) the absence of agreed-on outcomes of training and/or accepted assessments of those outcomes, and (2) the lack of standardized ways to communicate the results of those assessments. To improve the current learner handover situation, an authentic, shared mental model of competency is needed; high-quality tools to assess that competency must be developed and tested; and transparent, reliable, and safe ways to communicate this information must be created.To achieve these goals, the authors propose using a learner handover process modeled after a patient handover process. The CLASS model includes a description of the learner's Competency attainment, a summary of the Learner's performance, an Action list and statement of Situational awareness, and Synthesis by the receiving program. This model also includes coaching oriented towards improvement along the continuum of education and care. Just as studies have evaluated patient handover models using metrics that matter most to patients, studies must evaluate this learner handover model using metrics that matter most to providers, patients, and learners.

  6. Learner Agency within the Design of an EAP Course

    Science.gov (United States)

    Seppälä, Riina

    2015-01-01

    To meet the demands of today's society and working life, higher education should support the development of learner agency. How the agency of individual learners emerges in university courses and what kind of agency empowers the learners to face new challenges should be considered. In this article, the focus is on learner agency enabled and…

  7. Profiling Learners' Achievement Goals when Completing Academic Essays

    Science.gov (United States)

    Ng, Chi-Hung Clarence

    2009-01-01

    This study explored adult learners' goal profiles in relation to the completion of a compulsory academic essay. Based on learners' scores on items assessing mastery, performance-approach, and work-avoidance goals, cluster analyses produced three distinct categories of learners: performance-focused, work-avoidant, and multiple-goal learners. These…

  8. Unskilled work and learner identity

    DEFF Research Database (Denmark)

    Kondrup, Sissel

    The main argument in this paper is: In order to comprehend the ‘invisible’ conditions for forming motivation to participate in different kinds of learning activities (formal, non-formal and informal) in relation to work-life it is crucial to develop a dialectic concept of learner identity....... A concept enabling researcher in the field of work and learning to examine how the orientation toward learning activities are situated in and conditioned by specific work-life experiences. Based on a qualitative research-project (Kondrup 2012) the paper outlines how unskilled work forms a specific condition...... for engaging in learning. The aim of the project was to examine the challenges in order to fulfil the Danish national strategy on Lifelong learning and training for all. Danish as well as international research reveals that low skilled workers and workers in small and medium sized private companies tend...

  9. Brightness-normalized Partial Least Squares Regression for hyperspectral data

    International Nuclear Information System (INIS)

    Feilhauer, Hannes; Asner, Gregory P.; Martin, Roberta E.; Schmidtlein, Sebastian

    2010-01-01

    Developed in the field of chemometrics, Partial Least Squares Regression (PLSR) has become an established technique in vegetation remote sensing. PLSR was primarily designed for laboratory analysis of prepared material samples. Under field conditions in vegetation remote sensing, the performance of the technique may be negatively affected by differences in brightness due to amount and orientation of plant tissues in canopies or the observing conditions. To minimize these effects, we introduced brightness normalization to the PLSR approach and tested whether this modification improves the performance under changing canopy and observing conditions. This test was carried out using high-fidelity spectral data (400-2510 nm) to model observed leaf chemistry. The spectral data was combined with a canopy radiative transfer model to simulate effects of varying canopy structure and viewing geometry. Brightness normalization enhanced the performance of PLSR by dampening the effects of canopy shade, thus providing a significant improvement in predictions of leaf chemistry (up to 3.6% additional explained variance in validation) compared to conventional PLSR. Little improvement was made on effects due to variable leaf area index, while minor improvement (mostly not significant) was observed for effects of variable viewing geometry. In general, brightness normalization increased the stability of model fits and regression coefficients for all canopy scenarios. Brightness-normalized PLSR is thus a promising approach for application on airborne and space-based imaging spectrometer data.

  10. Sky brightness and twilight measurements at Jogyakarta city, Indonesia

    International Nuclear Information System (INIS)

    Herdiwijaya, Dhani

    2016-01-01

    The sky brightness measurements were performed using a portable photometer. A pocket-sized and low-cost photometer has 20 degree area measurement, and spectral ranges between 320-720 nm with output directly in magnitudes per arc second square (mass) unit. The sky brightness with 3 seconds temporal resolutions was recorded at Jogyakarta city (110° 25’ E; 70° 52’ S; elevation 100 m) within 136 days in years from 2014 to 2016. The darkest night could reach 22.61 mpass only in several seconds, with mean value 18.8±0.7 mpass and temperature variation 23.1±1.2 C. The difference of mean sky brightness between before and after midnight was about -0.76 mpass or 2.0 times brighter. Moreover, the sky brightness and temperature fluctuations were more stable in after midnight than in before midnight. It is suggested that city light pollution affects those variations, and subsequently duration of twilight. By comparing twilight brightness for several places, we also suggest a 17° solar dip or about 66 minutes before sunrise for new time of Fajr prayer. (paper)

  11. A New Approach of an Intelligent E-Learning System Based on Learners' Skill Level and Learners' Success Rate

    Science.gov (United States)

    Mohamed, Hafidi; Lamia, Mahnane

    2015-01-01

    Learners usually meet cognitive overload and disorientation problems when using e-learning system. At present, most of the studies in e-learning either concentrate on the technological aspect or focus on adapting learner's interests or browsing behaviors, while, learner's skill level and learners' success rate is usually neglected. In this paper,…

  12. Bright and Not-So-Bright Prospects for Women in Physics in China-Beijing

    Science.gov (United States)

    Wu, Ling-An; Yang, Zhongqin; Ma, Wanyun

    2009-04-01

    Science in China-Beijing is enjoying a healthy increase in funding year by year, so the prospects for physicists are also bright. However, employment discrimination against women, formerly unthinkable, is becoming more and more explicit as the country evolves toward a market economy. Some recruitment notices bluntly state that only men will be considered, or impose restrictions upon potential female candidates. Female associate professors in many institutions are forced to retire at age 55, compared with 60 for men. This double-pinching discrimination against both younger and older women threatens to lead to a "pincer" effect, more serious than the "scissors" effect. Indeed, the ratio of senior-level women physicists in general has dropped significantly in recent years in China. Ironically, the number of female students applying for graduate studies is on the rise, as it is becoming increasingly difficult for them to compete with men in the job market with just an undergraduate degree. The Chinese Physical Society has made certain efforts to promote the image of women physicists, but it will take time and effort to reverse the trend.

  13. Low dimensional neutron moderators for enhanced source brightness

    DEFF Research Database (Denmark)

    Mezei, Ferenc; Zanini, Luca; Takibayev, Alan

    2014-01-01

    In a recent numerical optimization study we have found that liquid para-hydrogen coupled cold neutron moderators deliver 3–5 times higher cold neutron brightness at a spallation neutron source if they take the form of a flat, quasi 2-dimensional disc, in contrast to the conventional more voluminous...... for cold neutrons. This model leads to the conclusions that the optimal shape for high brightness para-hydrogen neutron moderators is the quasi 1-dimensional tube and these low dimensional moderators can also deliver much enhanced cold neutron brightness in fission reactor neutron sources, compared...... to the much more voluminous liquid D2 or H2 moderators currently used. Neutronic simulation calculations confirm both of these theoretical conclusions....

  14. Bright Stuff on Ceres = Sulfates and Carbonates on CI Chondrites

    Science.gov (United States)

    Zolensky, Michael; Chan, Queenie H. S.; Gounelle, Matthieu; Fries, Marc

    2016-01-01

    Recent reports of the DAWN spacecraft's observations of the surface of Ceres indicate that there are bright areas, which can be explained by large amounts of the Mg sulfate hexahydrate (MgSO4•6(H2O)), although the identification appears tenuous. There are preliminary indications that water is being evolved from these bright areas, and some have inferred that these might be sites of contemporary hydro-volcanism. A heat source for such modern activity is not obvious, given the small size of Ceres, lack of any tidal forces from nearby giant planets, probable age and presumed bulk composition. We contend that observations of chondritic materials in the lab shed light on the nature of the bright spots on Ceres

  15. A high brightness probe of polymer nanoparticles for biological imaging

    Science.gov (United States)

    Zhou, Sirong; Zhu, Jiarong; Li, Yaping; Feng, Liheng

    2018-03-01

    Conjugated polymer nanoparticles (CPNs) with high brightness in long wavelength region were prepared by the nano-precipitation method. Based on fluorescence resonance energy transfer (FRET) mechanism, the high brightness property of the CPNs was realized by four different emission polymers. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) displayed that the CPNs possessed a spherical structure and an average diameter of 75 nm. Analysis assays showed that the CPNs had excellent biocompatibility, good photostability and low cytotoxicity. The CPNs were bio-modified with a cell penetrating peptide (Tat, a targeted element) through covalent link. Based on the entire wave fluorescence emission, the functionalized CPNs1-4 can meet multichannel and high throughput assays in cell and organ imaging. The contribution of the work lies in not only providing a new way to obtain a high brightness imaging probe in long wavelength region, but also using targeted cell and organ imaging.

  16. Low surface brightness galaxies in the cluster A1367

    International Nuclear Information System (INIS)

    Davies, J.I.; Phillipps, S.; Disney, M.J.

    1989-01-01

    We have obtained deep CCD frames of apparently blank regions of sky in the hope of detecting very low surface brightness (LSB) objects in the cluster A1367. We discuss our data reduction, and image detection and selection techniques. If the galaxies detected are actually cluster members then they are dwarfs and the conclusions of a previous paper on the Fornax cluster are essentially confirmed. One area of variance is that the lowest surface brightness galaxies do not appear to be preferentially concentrated towards the cluster centre. This can be explained by there being a much larger density of dwarf galaxies over this bright galaxy-rich region of the universe. We find over our small area approximately four times as many LSB galaxies as would be expected from our Fornax data. We speculate on the possible origin and likely intensity of intergalactic light within clusters. (author)

  17. The Rwandan teachers' and learners' perceived speaking ...

    African Journals Online (AJOL)

    owner

    The innovation of Spolsky's (1989) model of second language learning is that it was presented in the form of a mathematic ... perceived proficiency in speaking Kinyarwanda and English. Methods .... is very effective for the learners' learning.

  18. Early Learner Engagement in the Clinical Workplace

    NARCIS (Netherlands)

    Chen, H.C.

    2015-01-01

    Introduction Recent calls for medical education reform advocate for the integration of knowledge with clinical experience through early clinical immersion. Yet, early learners rarely are invited to participate in workplace activities and early clinical experiences remain largely observational.

  19. Leonids 2017 from Norway – A bright surprise!

    Science.gov (United States)

    Gaarder, K.

    2018-01-01

    I am very pleased to have been able to observe near maximum activity of the Leonids, and clearly witnessed the unequal mass distribution during these hours. A lot of bright Leonids were seen, followed by a short period of high activity of fainter meteors, before a sharp drop in activity. The Leonids is undoubtedly a shower to watch closely, with its many variations in activity level and magnitude distribution. I already look forward to observing the next years’ display, hopefully under a dark and clear sky, filled with bright meteors!

  20. Sky Brightness During Eclipses: A Compendium from the Literature

    Science.gov (United States)

    1974-08-05

    Star Sightings 1880A 11 Jan 1880 Santa- Lucia Jupiter -3 Mars .3 No stars 1882A 17 May 1882 Sohag, Egypt Stars shone brightly 1883A 6 M.»y 1883...1870 E 1880 A 1886 BA 1887 F 1889 A2 1900 EB 1914 A 1927 B Location London Venice Bue Island Gottenbui g Vumpurthy Seville Santa- Lucia ...manner, and at the peak of day the stars ap- peared brightly. (Tatti Annali sacri della citta di Como.) 5 MAY 840 840 DB Ginzel p. 668 Italy In

  1. Brightness distribution data on 2918 radio sources at 365 MHz

    International Nuclear Information System (INIS)

    Cotton, W.D.; Owen, F.N.; Ghigo, F.D.

    1975-01-01

    This paper is the second in a series describing the results of a program attempting to fit models of the brightness distribution to radio sources observed at 365 MHz with the Bandwidth Synthesis Interferometer (BSI) operated by the University of Texas Radio Astronomy Observatory. Results for a further 2918 radio sources are given. An unresolved model and three symmetric extended models with angular sizes in the range 10--70 arcsec were attempted for each radio source. In addition, for 348 sources for which other observations of brightness distribution are published, the reference to the observations and a brief description are included

  2. Language Learner Beliefs from an Attributional Perspective

    OpenAIRE

    Gabillon, Zehra

    2013-01-01

    International audience; This qualitative study, aimed to analyze eight French-speaking learners' beliefs about English and English language learning. The data were obtained via semi-structured interviews. The study drew on Weiner's attribution theory of achievement motivation and Bandura's self-efficacy theory. The novelty about this research is the employment of an attributional analysis framework to study and explain the learners' stated beliefs about English and English language learning.

  3. Exploring high school learners' perceptions of bullying.

    Science.gov (United States)

    Blake, Patricia; Louw, Johann

    2010-12-01

    Learners' perceptions of aspects of school life that are sufficiently serious to interfere with their schoolwork were investigated. Bullying was a form of behaviour that was singled out for inclusion and further exploration in the study. Learners from three coeducational Western Cape Education Department schools were surveyed: 414 Grade 8 and 474 Grade 9 learners completed an anonymous, voluntary self-report questionnaire. Factors identified as most frequently interfering with their schoolwork included classmates not listening in class, feeling overwhelmed by schoolwork, teacher absenteeism, and verbal fighting. When asked specifically about bullying, 40% of learners indicated that they frequently experienced bullying at school-although they ranked it as much lower when compared to other potentially problematic school experiences. Furthermore, although the majority of learners indicated they thought teachers considered bullying a problem, few felt there was anything that school staff could do to counteract bullying effectively. These findings suggest that learners perceive bullying as an unavoidable part of school experience and have normalised this aggressive behaviour.

  4. The Effect of Flipped Model of Instruction on EFL Learners' Reading Comprehension: Learners' Attitudes in Focus

    Science.gov (United States)

    Karimi, Mehrnoosh; Hamzavi, Raouf

    2017-01-01

    The present study aimed at investigating the effect of flipped model of instruction on EFL learners' reading comprehension ability. Moreover, this study aimed at identifying EFL students' attitudes toward flipped model of instruction. To this end, 60 EFL learners studying at an accredited private language institute in Isfahan were first…

  5. An Analysis of Lexical Errors of Korean Language Learners: Some American College Learners' Case

    Science.gov (United States)

    Kang, Manjin

    2014-01-01

    There has been a huge amount of research on errors of language learners. However, most of them have focused on syntactic errors and those about lexical errors are not found easily despite the importance of lexical learning for the language learners. The case is even rarer for Korean language. In line with this background, this study was designed…

  6. Learners' perceptions of learners regarded as having a homosexual orientation in an independent secondary school environment.

    Science.gov (United States)

    Mostert, Hendrik P; Myburgh, Chris; Poggenpoel, Marie

    2012-10-04

    In schools today discrimination based on sexual orientation takes place on a regular basis. This form of discrimination leads to aggression towards learners perceived to be homosexual, as well as towards those with a homosexual orientation. For more than 15 years South Africa has been a democratic country with laws that protect learners who have a homosexual orientation. Nevertheless, aggression and discrimination towards these learners still occur in schools. Aggression often leads to verbal and physical bullying of the victims by perpetrators. The objectives of this research were to explore and describe Grade 11 learners' experiences of aggression towards learners perceived to be homosexual as well as those with a homosexual orientation in an independent secondary school environment. The research design was qualitative, exploratory, descriptive and contextual in nature. The data for this investigation consisted of essays based on a published newspaper photograph, phenomenological group interviews, observations and field notes. Tesch's method of data analysis was used, and an independent coder assisted. Three themes were identified, discussed and supported by a literature control: that learners experience that it is right and acceptable to have a homosexual orientation; that they experience ambivalence towards homosexual orientation of learners; and experienced feelings that it is wrong to have a homosexual orientation. Recommended guidelines are provided to address aggression towards learners perceived to be homosexual and those with a homosexual orientation.

  7. ECG Rhythm Analysis with Expert and Learner-Generated Schemas in Novice Learners

    Science.gov (United States)

    Blissett, Sarah; Cavalcanti, Rodrigo; Sibbald, Matthew

    2015-01-01

    Although instruction using expert-generated schemas is associated with higher diagnostic performance, implementation is resource intensive. Learner-generated schemas are an alternative, but may be limited by increases in cognitive load. We compared expert- and learner-generated schemas for learning ECG rhythm interpretation on diagnostic accuracy,…

  8. Learner Beliefs about Sociolinguistic Competence: A Qualitative Case Study of Four University Second Language Learners

    Science.gov (United States)

    Yang, Jinsuk; Rehner, Katherine

    2015-01-01

    This article explores the beliefs about second language (L2) sociolinguistic competence of four university-level advanced L2 learners. It places particular emphasis on 1) how these university learners conceptualized L2 sociolinguistic competence; 2) how they thought about two different language learning contexts (viz., the L2 classroom versus…

  9. 41 CFR 50-202.3 - Learners, student learners, apprentices, and handicapped workers.

    Science.gov (United States)

    2010-07-01

    ... than the minimum wage prescribed in § 50-202.2 to the same extent such employment is permitted under... Management Other Provisions Relating to Public Contracts PUBLIC CONTRACTS, DEPARTMENT OF LABOR 202-MINIMUM WAGE DETERMINATIONS Groups of Industries § 50-202.3 Learners, student learners, apprentices, and...

  10. Fluorescence brightness and photostability of individual copper (I) oxide nanocubes.

    Science.gov (United States)

    Zohora, Nafisa; Kandjani, Ahmad Esmaielzadeh; Orth, Antony; Brown, Hannah M; Hutchinson, Mark R; Gibson, Brant C

    2017-12-04

    Conventional organic fluorophores lose their ability to fluoresce after repeated exposure to excitation light due to photobleaching. Therefore, research into emerging bright and photostable nanomaterials has become of great interest for a range of applications such as bio-imaging and tracking. Among these emerging fluorophores, metal oxide-based nanomaterials have attracted significant attention as a potential multifunctional material with photocatalytic and angeogenisis abilities in addition to fluorescnce applications. However, most of these applications are highly dependent on size, morphology, and chemo-physical properties of individual particles. In this manuscript, we present a method to study the intrinsic optical characteristics of individual copper (I) oxide (Cu 2 O) nanocubes. When excited at 520 nm using only 11 µW excitation power (1.7 W/cm2), individual nanocubes were observed to emit light with peak wavelengths ~760 nm which is conveniently within the near-infrared 1 (NIR1) biological window where tissue autofluorescence is minimal. Bright and photostable fluorescence was observed with intensities up to 487 K counts/s under constant illumination for at least 2 minutes with a brightness approximately four times higher than the autofluorescence from a fixed cumulus-oocyte complex. With near-IR emission, high fluorescence brightness, and outstanding photostability, Cu 2 O nanocubes are attractive candidates for long-term fluorescent bioimaging applications.

  11. Bright infrared LEDs based on colloidal quantum-dots

    KAUST Repository

    Sun, Liangfeng; Choi, Joshua J.; Stachnik, David; Bartnik, Adam C.; Hyun, Byung-Ryool; Malliaras, George G.; Hanrath, Tobias; Wise, Frank W.

    2013-01-01

    Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm. © 2013 Materials Research Society.

  12. The star-bright hour : [luuletused] / Betti Alver

    Index Scriptorium Estoniae

    Alver, Betti, 1906-1989

    2006-01-01

    Sisu: The star-bright hour ; Not a dream ; The Piper ; Corals in an ancent river. Luuletused pärinevad kogumikust "Tuulelaeval valgusest on aerud = Windship with Oars of Light. (Tallinn : Huma, 2001). Orig.: Tähetund ; Mitte viirastus, meelepett ; Vilepuhuja ; Korallid Emajões

  13. Optical variability of the medium-bright quasar sample

    International Nuclear Information System (INIS)

    Huang, K.; Mitchell, K.J.; Usher, P.D.

    1990-01-01

    A variability study of the 32-member Medium-Bright Quasar Sample is reported. It is found that the star US 1953 has undergone a noticeable variation in the course of 26 hr. Apparent variations in the extragalactic object US 3498 may be illusory, owing to its partially resolved appearance. No other evidence for variability was detected. 34 refs

  14. A surface brightness analysis of eight RR Lyrae stars

    International Nuclear Information System (INIS)

    Hawley, S.L.; Barnes, T.G. III; Moffett, T.J.

    1987-01-01

    The authors have used a surface brightness, (V-R) relation to analyze new contemporaneous photometry and radial velocity data for 6 RR-ab type stars and to re-analyze previously published data for RR Lyrae and X Arietis. Systematic effects were found in the surface brightness at phases near minimum radius. Excluding these phases, they determine the slope of the surface brightness relation and the mean radius for each star. They also find a zero point which includes both a distance term and the zero point of the surface brightness relation. The sample includes stars with Preston's metallicity indicator ΔS = 0 to 9, with periods ranging from 0.397 days to 0.651 days. Their results indicate a log(R/R solar ) vs. log P relation in the sense that stars with longer periods have larger radii, in agreement with theoretical predictions. Their radii are consistent with bolometric magnitudes in the range 0.2 - 0.8 magnitude but accurate magnitudes must await a reliable T e - color calibration

  15. Response of noctilucent cloud brightness to daily solar variations

    Science.gov (United States)

    Dalin, P.; Pertsev, N.; Perminov, V.; Dubietis, A.; Zadorozhny, A.; Zalcik, M.; McEachran, I.; McEwan, T.; Černis, K.; Grønne, J.; Taustrup, T.; Hansen, O.; Andersen, H.; Melnikov, D.; Manevich, A.; Romejko, V.; Lifatova, D.

    2018-04-01

    For the first time, long-term data sets of ground-based observations of noctilucent clouds (NLC) around the globe have been analyzed in order to investigate a response of NLC to solar UV irradiance variability on a day-to-day scale. NLC brightness has been considered versus variations of solar Lyman-alpha flux. We have found that day-to-day solar variability, whose effect is generally masked in the natural NLC variability, has a statistically significant effect when considering large statistics for more than ten years. Average increase in day-to-day solar Lyman-α flux results in average decrease in day-to-day NLC brightness that can be explained by robust physical mechanisms taking place in the summer mesosphere. Average time lags between variations of Lyman-α flux and NLC brightness are short (0-3 days), suggesting a dominant role of direct solar heating and of the dynamical mechanism compared to photodissociation of water vapor by solar Lyman-α flux. All found regularities are consistent between various ground-based NLC data sets collected at different locations around the globe and for various time intervals. Signatures of a 27-day periodicity seem to be present in the NLC brightness for individual summertime intervals; however, this oscillation cannot be unambiguously retrieved due to inevitable periods of tropospheric cloudiness.

  16. Matter-wave bright solitons in effective bichromatic lattice potentials

    Indian Academy of Sciences (India)

    Matter-wave bright solitons in bichromatic lattice potentials are considered and their dynamics for different lattice environments are studied. Bichromatic potentials are created from superpositions of (i) two linear optical lattices and (ii) a linear and a nonlinear optical lattice. Effective potentials are found for the solitons in both ...

  17. Matter wave interference pattern in the collision of bright solitons

    International Nuclear Information System (INIS)

    Kumar, V. Ramesh; Radha, R.; Panigrahi, Prasanta K.

    2009-01-01

    We investigate the dynamics of Bose-Einstein condensates in a quasi one-dimensional regime in a time-dependent trap and show analytically that it is possible to observe matter wave interference patterns in the intra-trap collision of two bright solitons by selectively tuning the trap frequency and scattering length.

  18. The morphology and surface brightness of extragalactic jets

    International Nuclear Information System (INIS)

    Bicknell, G.V.

    1983-01-01

    The problems associated with laminar flow models are reviewed, and an analogy between laboratory jets and astrophysical jets is given. The relationship between surface brightness and the jet full width half maximum is not in general as predicted by simple magnetohydrodynamic models. An alternative turbulent model is presented

  19. Minimum-phase distribution of cosmic source brightness

    International Nuclear Information System (INIS)

    Gal'chenko, A.A.; Malov, I.F.; Mogil'nitskaya, L.F.; Frolov, V.A.

    1984-01-01

    Minimum-phase distributions of brightness (profiles) for cosmic radio sources 3C 144 (the wave lambda=21 cm), 3C 338 (lambda=3.5 m), and 3C 353 (labda=31.3 cm and 3.5 m) are obtained. A real possibility for the profile recovery from module fragments of its Fourier-image is shown

  20. The "Brightness Rules" Alternative Conception for Light Bulb Circuits

    Science.gov (United States)

    Bryan, Joel A.; Stuessy, Carol

    2006-01-01

    An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the…

  1. The star-bright hour : [poems] / Betti Alver

    Index Scriptorium Estoniae

    Alver, Betti, 1906-1989

    2003-01-01

    Autori lühitutvustus lk. 231. Sisu: The star-bright hour ; The debt ; Not a dream ; Fog-bound ; Corals in an Ancient river ; Frou-frou 1-3. Orig.: Tähetund ; Vilepuhuja ; Võlg ; "Mitte viirastus, meelepett..." ; Udus ; Korallid Emajões ; Froufrou 1-3

  2. High-brightness fiber-coupled pump laser development

    Science.gov (United States)

    Price, Kirk; Karlsen, Scott; Leisher, Paul; Martinsen, Robert

    2010-02-01

    We report on the continued development of high brightness laser diode modules at nLIGHT Photonics. These modules, based on nLIGHT's PearlTM product platform, demonstrate excellence in output power, brightness, wavelength stabilization, and long wavelength performance. This system, based on 14 single emitters, is designed to couple diode laser light into a 105 μm fiber at an excitation NA of under 0.14. We demonstrate over 100W of optical power at 9xx nm with a diode brightness exceeding 20 MW/cm2-str with an operating efficiency of approximately 50%. Additional results show over 70W of optical coupled at 8xx nm. Record brilliance at wavelengths 14xx nm and longer will also be demonstrated, with over 15 W of optical power with a beam quality of 7.5 mm-mrad. These results of high brightness, high efficiency, and wavelength stabilization demonstrate the pump technology required for next generation solid state and fiber lasers.

  3. Near-infrared photometry of bright elliptical galaxies

    NARCIS (Netherlands)

    Peletier, R. F.; Valentijn, E. A.; Jameson, R. F.

    High-quality visual-infrared color profiles have been determined for elliptical galaxies for the first time. Surface photometry in J and K is presented for 12 bright elliptical galaxies, and the results have been combined with CCD data in visual passbands. It is shown that the galaxies become bluer

  4. 150 southern compact and bright-nucleus galaxies

    International Nuclear Information System (INIS)

    Fairall, A.P.

    1977-01-01

    Galaxies having regions of exceptionally high surface brightness have been selected from the ESO Quick Blue Survey and investigated by 'grating photography' -direct photography plus low-dispersion slitless spectroscopy. Two new Seyfert galaxies and a peculiar multiple system have been discovered. Differences in red continua are also noted. (author)

  5. Bright to dim oscillatory response of the Neurospora circadian oscillator.

    Science.gov (United States)

    Gooch, Van D; Johnson, Alicia E; Larrondo, Luis F; Loros, Jennifer J; Dunlap, Jay C

    2014-02-01

    The fungus Neurospora crassa constitutes an important model system extensively used in chronobiology. Several studies have addressed how environmental cues, such as light, can reset or synchronize a circadian system. By means of an optimized firefly luciferase reporter gene and a controllable lighting system, we show that Neurospora can display molecular circadian rhythms in dim light when cultures receive bright light prior to entering dim light conditions. We refer to this behavior as the "bright to dim oscillatory response" (BDOR). The bright light treatment can be applied up to 76 h prior to dim exposure, and it can be as short as 15 min in duration. We have characterized this response in respect to the duration of the light pulse, the time of the light pulse before dim, the intensity of dim light, and the oscillation dynamics in dim light. Although the molecular mechanism that drives the BDOR remains obscure, these findings suggest that a long-term memory of bright light exists as part of the circadian molecular components. It is important to consider the ecological significance of such dim light responses in respect to how organisms naturally maintain their timing mechanism in moonlight.

  6. Engaging learners in STEM education

    Directory of Open Access Journals (Sweden)

    Joseph Krajcik

    2017-04-01

    Full Text Available In this manuscript we focus on how to develop STEM learning environments, and how STEM can be implemented in K-12 schools. We focus on the following question: “How can we support students in building a deep, integrated knowledge of STEM so that they have the practical knowledge and problem solving skills necessary to live in and improve the world?” We also discuss criteria for evaluating STEM learning environments and the challenges teachers face in implementing STEM. We define STEM as the integration of science, engineering, technology, and mathematics to focus on solving pressing individual and societal problems. Engaging students in STEM also means engaging learners in the design process. Design is integral to student thinking in the STEM world. The design process is very non-linear and iterative in its nature but requires clearly articulating and identifying the design problem, researching what is known about the problem, generating potential solutions, developing prototype designs (artifacts that demonstrate solutions, and sharing and receiving feedback. With the integration of design, STEM education has the potential to support students in learning big ideas in science and engineering, as well as important scientific and engineering practices, and support students in developing important motivational outcomes such as ownership, agency and efficacy. Moreover, students who engage in STEM learning environments will also develop 21st century capabilities such as problem solving, communication, and collaboration skills.

  7. Progress in extremely high brightness LED-based light sources

    Science.gov (United States)

    Hoelen, Christoph; Antonis, Piet; de Boer, Dick; Koole, Rolf; Kadijk, Simon; Li, Yun; Vanbroekhoven, Vincent; Van De Voorde, Patrick

    2017-09-01

    Although the maximum brightness of LEDs has been increasing continuously during the past decade, their luminance is still far from what is required for multiple applications that still rely on the high brightness of discharge lamps. In particular for high brightness applications with limited étendue, e.g. front projection, only very modest luminance values in the beam can be achieved with LEDs compared to systems based on discharge lamps or lasers. With dedicated architectures, phosphor-converted green LEDs for projection may achieve luminance values up to 200-300 Mnit. In this paper we report on the progress made in the development of light engines based on an elongated luminescent concentrator pumped by blue LEDs. This concept has recently been introduced to the market as ColorSpark High Lumen Density LED technology. These sources outperform the maximum brightness of LEDs by multiple factors. In LED front projection, green LEDs are the main limiting factor. With our green modules, we now have achieved peak luminance values of 2 Gnit, enabling LED-based projection systems with over 4000 ANSI lm. Extension of this concept to yellow and red light sources is presented. The light source efficiency has been increased considerably, reaching 45-60 lm/W for green under practical application conditions. The module architecture, beam shaping, and performance characteristics are reviewed, as well as system aspects. The performance increase, spectral range extensions, beam-shaping flexibility, and cost reductions realized with the new module architecture enable a breakthrough in LED-based projection systems and in a wide variety of other high brightness applications.

  8. SKYMONITOR: A Global Network for Sky Brightness Measurements

    Science.gov (United States)

    Davis, Donald R.; Mckenna, D.; Pulvermacher, R.; Everett, M.

    2010-01-01

    We are implementing a global network to measure sky brightness at dark-sky critical sites with the goal of creating a multi-decade database. The heart of this project is the Night Sky Brightness Monitor (NSBM), an autonomous 2 channel photometer which measures night sky brightness in the visual wavelengths (Mckenna et al, AAS 2009). Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The NSBM consists of two parts, a remote unit and a base station with an internet connection. Currently these devices use 2.4 Ghz transceivers with a range of 100 meters. The remote unit is battery powered with daytime recharging using a solar panel. Data received by the base unit is transmitted via email protocol to IDA offices in Tucson where it will be collected, archived and made available to the user community via a web interface. Two other versions of the NSBM are under development: one for radio sensitive areas using an optical fiber link and the second that reads data directly to a laptop for sites without internet access. NSBM units are currently undergoing field testing at two observatories. With support from the National Science Foundation, we will construct and install a total of 10 units at astronomical observatories. With additional funding, we will locate additional units at other sites such as National Parks, dark-sky preserves and other sites where dark sky preservation is crucial. We will present the current comparison with the National Park Service sky monitoring camera. We anticipate that the SKYMONITOR network will be functioning by the end of 2010.

  9. Diode lasers optimized in brightness for fiber laser pumping

    Science.gov (United States)

    Kelemen, M.; Gilly, J.; Friedmann, P.; Hilzensauer, S.; Ogrodowski, L.; Kissel, H.; Biesenbach, J.

    2018-02-01

    In diode laser applications for fiber laser pumping and fiber-coupled direct diode laser systems high brightness becomes essential in the last years. Fiber coupled modules benefit from continuous improvements of high-power diode lasers on chip level regarding output power, efficiency and beam characteristics resulting in record highbrightness values and increased pump power. To gain high brightness not only output power must be increased, but also near field widths and far field angles have to be below a certain value for higher power levels because brightness is proportional to output power divided by beam quality. While fast axis far fields typically show a current independent behaviour, for broadarea lasers far-fields in the slow axis suffer from a strong current and temperature dependence, limiting the brightness and therefore their use in fibre coupled modules. These limitations can be overcome by carefully optimizing chip temperature, thermal lensing and lateral mode structure by epitaxial and lateral resonator designs and processing. We present our latest results for InGaAs/AlGaAs broad-area single emitters with resonator lengths of 4mm emitting at 976nm and illustrate the improvements in beam quality over the last years. By optimizing the diode laser design a record value of the brightness for broad-area lasers with 4mm resonator length of 126 MW/cm2sr has been demonstrated with a maximum wall-plug efficiency of more than 70%. From these design also pump modules based on 9 mini-bars consisting of 5 emitters each have been realized with 360W pump power.

  10. Learners' experiences of learning support in selected Western Cape schools

    Directory of Open Access Journals (Sweden)

    Olaniyi Bojuwoye

    2014-01-01

    Full Text Available The study explored Western Cape primary and secondary school learners' experiences regarding the provision and utilization of support services for improving learning. A qualitative interpretive approach was adopted and data gathered through focus group interviews involving 90 learners. Results revealed that learners received and utilized various forms of learning support from their schools, teachers, and peers. The learning support assisted in meeting learners' academic, social and emotional needs by addressing barriers to learning, creating conducive learning environments, enhancing learners' self-esteem and improving learners' academic performance.

  11. LEARNER AUTONOMY IN THE INDONESIAN EFL SETTINGS

    Directory of Open Access Journals (Sweden)

    Nenden Sri Lengkanawati

    2017-01-01

    Full Text Available Learner autonomy in Indonesian educational institutions has not commonly been listed as a teaching-learning objective, and most teachers seem to be hardly acquainted with learner autonomy (LA.  Therefore, it is very essential  to conduct a study of LA as perceived and experienced by school teachers and to find out the importance of LA training for professional development. A questionnaire was used to collect the data about English teachers’ perceptions regarding LA and LA-based practices. In addition, an LA training was conducted to see its significance for professional development.  After the data were qualitatively and quantitatively analyzed, it was found that the participating teachers tended to maintain that autonomy should be inculcated among learners, and that the LA concept should not be misinterpreted as learning without a teacher. Concerning choices and decisions by  the learners, it was believed that learners’ making choices about how they learned and what activities they did, and involving them to decide what and how to learn could promote autonomy among learners. As regards LA-based teaching-learning practices, it was revealed that most teachers desired to implement LA principles in their teaching-learning contexts, although they identified that many of the LA principles were not that feasible to apply in their situation. It was also found that LA training could improve the teachers’ perceptions regarding LA concepts and principles. There were some constraints which could make learner autonomy difficult to develop among Indonesian learners in general: limited time allotted for the implementation of the curriculum, learners’ lack of autonomous learning experience, too much focus on national examinations, and insufficient proficiency of English.  LA-based teaching-learning practices were most desired; however, many were considered as having insufficient feasibility. In this respect, commitment is certainly the key to

  12. LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' BRIGHTNESS VARIATIONS OF BRIGHT PLANET-HOST STARS

    International Nuclear Information System (INIS)

    Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua

    2014-01-01

    Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale brightness variations ( f licker ) of stars can be used to measure log g to a high accuracy of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 bright (Kepmag < 13) candidate planet-hosting stars with T eff = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the bright planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested

  13. The relationship between brightness temperature and soil moisture. Selection of frequency range for microwave remote sensing

    International Nuclear Information System (INIS)

    Rao, K.S.; Chandra, G.; Rao, P.V.N.

    1987-01-01

    The analysis of brightness temperature data acquired from field and aircraft experiments demonstrates a linear relationship between soil moisture and brightness temperature. However, the analysis of brightness temperature data acquired by the Skylab radiometer demonstrates a non-linear relationship between soil moisture and brightness temperature. In view of the above and also because of recent theoretical developments for the calculation of the dielectric constant and brightness temperature under varying soil moisture profile conditions, an attempt is made to study the theoretical relationship between brightness temperature and soil moisture as a function of frequency. Through the above analysis, the appropriate microwave frequency range for soil moisture studies is recommended

  14. Working with language learner histories from three perspectives: Teachers, learners and researchers

    Directory of Open Access Journals (Sweden)

    Sarah Mercer

    2013-10-01

    Full Text Available Recent developments in SLA, such as learner-centredness, social constructivism, the postmethod era, and complexity perspectives, have highlighted the need for more localized, situated understandings of teaching and learning and greater recognition of learner individuality and diversity. In this article, I suggest an effective way of meeting these needs is to employ learner histories. This powerful form of writing allows learners to use their L2 to engage in authentic, personally meaningful communication with others about their identities, experiences, perceptions and emotions related to their language learning histories. As a text type, they are able to facilitate a more holistic perspective of the learner’s life and reveal the unique interconnections that an individual makes across various domains. They also enable the situated, contextualised and dynamic nature of their learning experiences to become apparent and provide learners with a genuine, motivating purpose for writing. Exploring data generated in Austria with tertiary-level EFL learners, I seek to illustrate some of the rich potential of these text types from three perspectives, namely, those of the teacher, learner and researcher.

  15. 233 Meaning and the Second Language Learner Jane Nkechi ...

    African Journals Online (AJOL)

    Ike Odimegwu

    second language learner seeks to interpret word meaning without reference to the .... Meaning can be natural but language is conventional - that is there is no .... language learner is usually engaged in processing contextual information to ...

  16. The Teaching Strategies used by Teachers for Learners with Autism ...

    African Journals Online (AJOL)

    The learning needs of learners with multiple disabilities in Kenya are not ... of the Kenyan special schools and units combine learners with multiple disabilities into ... specific disabilities such as visual, hearing, mental and physical impairments.

  17. Free State educators' perceptions of the scope of learner crime

    African Journals Online (AJOL)

    Erna Kinsey

    preceding may prompt the community to label children who break the .... learning that sexual violence and abuse are an inescapable part of going to school every ..... Learners try to sidestep paying for movies, taxi travel, food, etc. Learners ...

  18. ADULT LEARNERS IN DISTANCE HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    NORICA-FELICIA BUCUR

    2012-05-01

    Full Text Available This paper attempts at identifying the main features that characterize distance higher education and adult education, respectively, in order to be able to establish to what extent adult learners can fit in distance higher education programs. The historical background of distance learning education, the factors that influence adult learners, and distance learning’s key objectives, effects, issues, advantages, and disadvantages are to be briefly investigated in order to reach the purpose of this paper. Recent developments in Information Technology have led to a new approach to teaching and learning, especially as far as adult learning and distance learning are concerned. Thus, this study will also focus on the consequences of using technology for course design, delivery, and the perception of adult learners participating in distance learning.

  19. Nurturing gifted learners in Mainland China

    DEFF Research Database (Denmark)

    Shi, Jiannong; Zhang, X.; Chen, N.

    2013-01-01

    -socio-intellectual model, illustrated the nature of human being and the nature of gifted learners. From the perspective of the BSI model, the authors suggested three aspects are very critical to curriculum design to meet the needs of gifted education: physical maturation or physical development, social maturation......In this article, based on the previous researches on the development of gifted learners, the authors summarized the problems in nurturing gifted learners due to lacking of the appropriate educational philosophy and educational methodology in Mainland China. The authors proposed the Bio...... or social and interpersonal development, and mental maturation or intellectual development. It was proved that BSI model has its theoretical rationality and practical validity in Mainland China...

  20. Technologies for learner-centered feedback

    Directory of Open Access Journals (Sweden)

    Jane Costello

    2013-09-01

    Full Text Available As the number, type, and use of technologies to support learning increases, so do the opportunities for using these technologies for feedback. Learner-centered feedback is a core to the teaching-learning process. It is related to assessment in describing how learners perform in their learning, their gain in knowledge, skills, and attitudes. Feedback, types of feedback, guidelines for effective learner-centered feedback, and feedback’s relationship to assessment are presented. Methods of providing feedback, for example, automated, audio scribe pens, digital audio, etc., and the related technologies are described. Technologies that allow instructors to make informed decisions about the use of various methods for feedback are discussed.

  1. Empowering the Learner through Digital Animated Storytelling

    DEFF Research Database (Denmark)

    Gjedde, Lisa

    2012-01-01

    The advent of new media offer potentials for multimodal learning [1] to the learners. This also calls for new learning designs that fully make use of digital media and explore how they can be used to create a motivating and meaningful learning environment that addresses the learner’s individual...... to the general ability to make meaning out of experience.” One way to design for narrative multimodal learning is to introduce the learners to the tools to make digital animated stories as a way to work with literacies in the classroom. In this way it may offer the learners a platform for meaningful involvement....... Storytelling and narrative is fundamental to the process of meaning making according to the seminal works of cultural psychologist Jerome Bruner [2]. .As the Canadian educational theorist Kieran Egan [3] suggests, there is an important relationship between storytelling and imagination because it is ”central...

  2. Developing the master learner: applying learning theory to the learner, the teacher, and the learning environment.

    Science.gov (United States)

    Schumacher, Daniel J; Englander, Robert; Carraccio, Carol

    2013-11-01

    As a result of the paradigm shift to a competency-based framework, both self-directed lifelong learning and learner-centeredness have become essential tenets of medical education. In the competency-based framework, learners drive their own educational process, and both learners and teachers share the responsibility for the path and content of learning. This learner-centered emphasis requires each physician to develop and maintain lifelong learning skills, which the authors propose culminate in becoming a "master leaner." To better understand the development of these skills and the attainment of that goal, the authors explore how learning theories inform the development of master learners and how to translate these theories into practical strategies for the learner, the teacher, and the learning environment so as to optimize this development.The authors begin by exploring self-determination theory, which lays the groundwork for understanding the motivation to learn. They next consider the theories of cognitive load and situated cognition, which inform the optimal context and environment for learning. Building from this foundation, the authors consider key educational theories that affect learners' abilities to serve as primary drivers of their learning, including self-directed learning (SDL); the self-assessment skills necessary for SDL; factors affecting self-assessment (self-concept, self-efficacy, illusory superiority, gap filling); and ways to mitigate the inaccuracies of self-assessment (reflection, self-monitoring, external information seeking, and self-directed assessment seeking).For each theory, they suggest practical action steps for the learner, the teacher, and the learning environment in an effort to provide a road map for developing master learners.

  3. Learner Autonomy in Foreign Language Education and in Cultural Context

    OpenAIRE

    Ivanovska, Biljana

    2015-01-01

    The present paper is a brief review of the theoretical concepts about learner autonomy focusing on highlighting the main themes on learner autonomy in foreign language education and in cultural context as a globalized construct. These themes are based on the concepts of learner responsibility and independence, the importance of the autonomy in foreign language education in both the Western and Eastern style and the role of the culture in the concept of learner independence. The present study ...

  4. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  5. Modeling laser brightness from cross Porro prism resonators

    Science.gov (United States)

    Forbes, Andrew; Burger, Liesl; Litvin, Igor Anatolievich

    2006-08-01

    Laser brightness is a parameter often used to compare high power laser beam delivery from various sources, and incorporates both the power contained in the particular mode, as well as the propagation of that mode through the beam quality factor, M2. In this study a cross Porro prism resonator is considered; crossed Porro prism resonators have been known for some time, but until recently have not been modeled as a complete physical optics system that allows the modal output to be determined as a function of the rotation angle of the prisms. In this paper we consider the diffraction losses as a function of the prism rotation angle relative to one another, and combine this with the propagation of the specific modes to determine the laser output brightness as a function of the prism orientation.

  6. Optical Observations of X-ray Bright, Optically Normal Galaxies

    Science.gov (United States)

    Sadun, Alberto C.; Aryan, N. S.; Ghosh, K. K.

    2007-05-01

    X-ray bright, optically normal galaxies (XBONGs) are galaxies that seem to have normal spectra and morphology, but are relatively bright x-ray sources. The large ratio of the x-ray to optical emission suggests that some activity, similar to that of active galactic nuclei (AGN), is occurring. Since the galaxies do not show any obvious sign of nuclear activity in their optical spectra, one possible explanation is that these galaxies do not have an optically thick accretion disk at small radii, as previously assumed. Previous data for NGC 7626 classifies it as an XBONG, and so we are studying optical features of this galaxy in order to determine better its features. After confirming an x-ray jet, we are now comparing this to optical features that we have found, including warped dust lanes and a possible optical jet.

  7. Large-scale brightness inhomogeneities in the solar atmosphere

    International Nuclear Information System (INIS)

    Mitchell, W.E. Jr.

    1982-01-01

    The intensity residuals are analyzed from a series of solar limb-darkening measurements in the wavelength range 5656 to 2997 A. The lengths of residual strings of the same sign exceed expectation by several orders of magnitude. The power spectrum fo the residuals shows a weak excess around 6000 km. For further study the 34000 limb-darkening residuals are subdivided into 5100 bright and faint cells. The frequency distribution of cell sizes peaks around 4500 km and increases from center to limb, the faint cells showing the greater center-limb effect. The cells are also studied as to contrast. A synoptic view indicates that only 12% of the cells are identifiable after a half hour. Phenomena that may combine to produce the observed wide spectrum of brightness inhomogeneities are briefly discussed. (orig.)

  8. The ASAS-SN bright supernova catalogue - III. 2016

    Science.gov (United States)

    Holoien, T. W.-S.; Brown, J. S.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Prieto, J. L.; Dong, Subo; Brimacombe, J.; Bishop, D. W.; Bose, S.; Beacom, J. F.; Bersier, D.; Chen, Ping; Chomiuk, L.; Falco, E.; Godoy-Rivera, D.; Morrell, N.; Pojmanski, G.; Shields, J. V.; Strader, J.; Stritzinger, M. D.; Thompson, Todd A.; Woźniak, P. R.; Bock, G.; Cacella, P.; Conseil, E.; Cruz, I.; Fernandez, J. M.; Kiyota, S.; Koff, R. A.; Krannich, G.; Marples, P.; Masi, G.; Monard, L. A. G.; Nicholls, B.; Nicolas, J.; Post, R. S.; Stone, G.; Wiethoff, W. S.

    2017-11-01

    This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (mpeak ≤ 17), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-infrared through ultraviolet magnitudes of all host galaxies and the offsets of the supernovae from the centres of their hosts from public data bases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogues, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.

  9. Recent advances in high-brightness electron guns at AES

    International Nuclear Information System (INIS)

    Bluem, H.; Todd, A.M.M.; Cole, M.D.; Rathke, J.; Schultheiss, T.

    2003-01-01

    We describe a number of active Advanced Energy Systems projects pertaining to the development of advanced, high-brightness electron guns for various applications. These projects include a fully superconducting, CW RF gun, nearing test, that utilizes the niobium surface as the photocathode material. An integrated 100 mA, low emittance DC/SRF gun, ideal as an injector for ERL-type light sources and intended as the injector for a 100 kW FEL, is in late design stage. A parallel high-power, CW, normal-conducting L-band RF gun project has just begun. The early performance analysis for this gun also shows good promise as an injector for ERL-type light sources. Lastly, a fully axisymmetric RF gun, operating in X-band, is being studied as a source of extremely bright electron bunches

  10. Bright breathers in nonlinear left-handed metamaterial lattices

    Science.gov (United States)

    Koukouloyannis, V.; Kevrekidis, P. G.; Veldes, G. P.; Frantzeskakis, D. J.; DiMarzio, D.; Lan, X.; Radisic, V.

    2018-02-01

    In the present work, we examine a prototypical model for the formation of bright breathers in nonlinear left-handed metamaterial lattices. Utilizing the paradigm of nonlinear transmission lines, we build a relevant lattice and develop a quasi-continuum multiscale approximation that enables us to appreciate both the underlying linear dispersion relation and the potential for bifurcation of nonlinear states. We focus here, more specifically, on bright discrete breathers which bifurcate from the lower edge of the linear dispersion relation at wavenumber k=π . Guided by the multiscale analysis, we calculate numerically both the stable inter-site centered and the unstable site-centered members of the relevant family. We quantify the associated stability via Floquet analysis and the Peierls-Nabarro barrier of the energy difference between these branches. Finally, we explore the dynamical implications of these findings towards the potential mobility or lack thereof (pinning) of such breather solutions.

  11. Quantitative Image Restoration in Bright Field Optical Microscopy.

    Science.gov (United States)

    Gutiérrez-Medina, Braulio; Sánchez Miranda, Manuel de Jesús

    2017-11-07

    Bright field (BF) optical microscopy is regarded as a poor method to observe unstained biological samples due to intrinsic low image contrast. We introduce quantitative image restoration in bright field (QRBF), a digital image processing method that restores out-of-focus BF images of unstained cells. Our procedure is based on deconvolution, using a point spread function modeled from theory. By comparing with reference images of bacteria observed in fluorescence, we show that QRBF faithfully recovers shape and enables quantify size of individual cells, even from a single input image. We applied QRBF in a high-throughput image cytometer to assess shape changes in Escherichia coli during hyperosmotic shock, finding size heterogeneity. We demonstrate that QRBF is also applicable to eukaryotic cells (yeast). Altogether, digital restoration emerges as a straightforward alternative to methods designed to generate contrast in BF imaging for quantitative analysis. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  12. Very bright, near-infrared single photon emitters in diamond

    Directory of Open Access Journals (Sweden)

    D. W. M. Lau

    2013-09-01

    Full Text Available We demonstrate activation of bright diamond single photon emitters in the near infrared range by thermal annealing alone, i.e., without ion implantation. The activation is crucially dependent on the annealing ambient. The activation of the single photon emitters is only observed when the sample is annealed in forming gas (4% H2 in Ar above temperatures of 1000 °C. By contrast, no emitters are activated by annealing in vacuum, oxygen, argon or deuterium. The emitters activated by annealing in forming gas exhibit very bright emission in the 730-760 nm wavelength range and have linewidths of ∼1.5-2.5 nm at room temperature.

  13. High-brightness tapered laser diodes with photonic crystal structures

    Science.gov (United States)

    Li, Yi; Du, Weichuan; Kun, Zhou; Gao, Songxin; Ma, Yi; Tang, Chun

    2018-02-01

    Beam quality of tapered laser diodes is limited by higher order lateral mode. On purpose of optimizing the brightness of tapered laser diodes, we developed a novel design of tapered diodes. This devices based on InGaAs/AlGaAs asymmetry epitaxial structure, containing higher order lateral mode filtering schemes especially photonic crystal structures, which fabricated cost effectively by using standard photolithography and dry etch processes. Meanwhile, the effects of photonic crystal structures on mode control are also investigated theoretically by FDBPM (Finite-Difference Beam Propagation Method) calculation. We achieved a CW optical output power of 6.9W at 940nm for a single emitter with 4 mm cavity length. A nearly diffraction limited beam of M2 ≍1.9 @ 0.5W has been demonstrated, and a highest brightness of β =75MW/(cm2 ·sr) was reached.

  14. Using RSpec in an introductory bright star spectroscopy lab activity

    Science.gov (United States)

    Howe, James; Sitar, David J.

    2018-01-01

    After presenting at the North Carolina Section of the American Association of Physics Teachers during the fall 2016 meeting, we were encouraged to turn our poster into a paper. This article describes the strengthening of a bright star spectroscopy lab activity for introductory astronomy lab students (AST1002) at Appalachian State University. Explanations of the tools and methods used in the activity are included, particularly the preparation of additional materials using RSpec and calibrated instrument response curves.

  15. Manakins can produce iridescent and bright feather colours without melanosomes.

    Science.gov (United States)

    Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

    2016-06-15

    Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

  16. Thoughts About Nursing Curricula: Dark Clouds and Bright Lights.

    Science.gov (United States)

    Turkel, Marian C; Fawcett, Jacqueline; Amankwaa, Linda; Clarke, Pamela N; Dee, Vivien; Eustace, Rosemary; Hansell, Phyllis Shanley; Jones, Dorothy A; Smith, Marlaine C; Zahourek, Rothlyn

    2018-04-01

    In this essay, several nurse scholars who are particularly concerned about the contemporary state of nursing science present their concerns about the inclusion of nursing conceptual models and theories in the curricula of nursing programs (dark clouds) and ways in which the concerns have been addressed (bright lights). This essay is the second of two essays that were catalyzed by Barrett's paper, "Again, What Is Nursing Science?" The first essay was published in the previous issue of Nursing Science Quarterly.

  17. Human Adolescent Phase Response Curves to Bright White Light.

    Science.gov (United States)

    Crowley, Stephanie J; Eastman, Charmane I

    2017-08-01

    Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

  18. High-brightness switchable multiwavelength remote laser in air

    Energy Technology Data Exchange (ETDEWEB)

    Yao Jinping; Cheng Ya; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Zeng Bin; Li Guihua; Chu Wei; Ni Jielei; Zhang Haisu [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100080 (China); Xu Huailiang [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Chin, See Leang [Center for Optics, Universite Laval, Quebec City, Quebec G1V 0A6 (Canada)

    2011-11-15

    We demonstrate a harmonic-seeded switchable multiwavelength laser in air driven by intense midinfrared femtosecond laser pulses, in which population inversion occurs at an ultrafast time scale (i.e., less than {approx}200 fs) owing to direct formation of excited molecular nitrogen ions by strong-field ionization of inner-valence electrons. The bright multiwavelength laser in air opens the perspective for remote detection of multiple pollutants based on nonlinear optical spectroscopy.

  19. Very bright optical transient near the Trifid and Lagoon Nebulae

    Science.gov (United States)

    Dunsby, Peter

    2018-03-01

    Peter Dunsby (University of Cape Town) reports the detection of a very bright optical transient in the region between the Lagoon and Trifid Nebulae based on observations obtained from Cape Town on 20 March 2018, between 01:00 and 03:45 UT. The object was visible throughout the full duration of the observations and not seen when this field was observed previously (08 March 2018).

  20. Bright spots among the world’s coral reefs

    Science.gov (United States)

    Cinner, Joshua E.; Huchery, Cindy; MacNeil, M. Aaron; Graham, Nicholas A. J.; McClanahan, Tim R.; Maina, Joseph; Maire, Eva; Kittinger, John N.; Hicks, Christina C.; Mora, Camilo; Allison, Edward H.; D'Agata, Stephanie; Hoey, Andrew; Feary, David A.; Crowder, Larry; Williams, Ivor D.; Kulbicki, Michel; Vigliola, Laurent; Wantiez, Laurent; Edgar, Graham; Stuart-Smith, Rick D.; Sandin, Stuart A.; Green, Alison L.; Hardt, Marah J.; Beger, Maria; Friedlander, Alan; Campbell, Stuart J.; Holmes, Katherine E.; Wilson, Shaun K.; Brokovich, Eran; Brooks, Andrew J.; Cruz-Motta, Juan J.; Booth, David J.; Chabanet, Pascale; Gough, Charlie; Tupper, Mark; Ferse, Sebastian C. A.; Sumaila, U. Rashid; Mouillot, David

    2016-07-01

    Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries

  1. The quiet Sun brightness temperature at 408 MHz

    International Nuclear Information System (INIS)

    Avignon, Y.; Lantos, P.; Palagi, F.; Patriarchi, P.

    1975-01-01

    The flux of the radio quiet Sun and the brightness temperature at 408 MHz (73cm) are derived from measurements with the E-W Nancay interferometer and the E-W arm of the Medicina North Cross. It is shown that the lowest envelopes, which defined the radio quiet Sun, correspond to transits of extended coronal holes across the disk of the Sun. (Auth.)

  2. Brightness/darkness induction and the genesis of a contour

    Directory of Open Access Journals (Sweden)

    Sergio eRoncato

    2014-10-01

    Full Text Available Visual contours often result from the integration or interpolation of fragmented edges.The strength of the completion increases when the edges share the same contrast polarity (CP. Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP. The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different grey shades.These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in are blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this solution by the visual system

  3. Bright triplet excitons in caesium lead halide perovskites

    Science.gov (United States)

    Becker, Michael A.; Vaxenburg, Roman; Nedelcu, Georgian; Sercel, Peter C.; Shabaev, Andrew; Mehl, Michael J.; Michopoulos, John G.; Lambrakos, Samuel G.; Bernstein, Noam; Lyons, John L.; Stöferle, Thilo; Mahrt, Rainer F.; Kovalenko, Maksym V.; Norris, David J.; Rainò, Gabriele; Efros, Alexander L.

    2018-01-01

    Nanostructured semiconductors emit light from electronic states known as excitons. For organic materials, Hund’s rules state that the lowest-energy exciton is a poorly emitting triplet state. For inorganic semiconductors, similar rules predict an analogue of this triplet state known as the ‘dark exciton’. Because dark excitons release photons slowly, hindering emission from inorganic nanostructures, materials that disobey these rules have been sought. However, despite considerable experimental and theoretical efforts, no inorganic semiconductors have been identified in which the lowest exciton is bright. Here we show that the lowest exciton in caesium lead halide perovskites (CsPbX3, with X = Cl, Br or I) involves a highly emissive triplet state. We first use an effective-mass model and group theory to demonstrate the possibility of such a state existing, which can occur when the strong spin-orbit coupling in the conduction band of a perovskite is combined with the Rashba effect. We then apply our model to CsPbX3 nanocrystals, and measure size- and composition-dependent fluorescence at the single-nanocrystal level. The bright triplet character of the lowest exciton explains the anomalous photon-emission rates of these materials, which emit about 20 and 1,000 times faster than any other semiconductor nanocrystal at room and cryogenic temperatures, respectively. The existence of this bright triplet exciton is further confirmed by analysis of the fine structure in low-temperature fluorescence spectra. For semiconductor nanocrystals, which are already used in lighting, lasers and displays, these excitons could lead to materials with brighter emission. More generally, our results provide criteria for identifying other semiconductors that exhibit bright excitons, with potential implications for optoelectronic devices.

  4. Bright to Dim Oscillatory Response of the Neurospora Circadian Oscillator

    OpenAIRE

    Gooch, Van D.; Johnson, Alicia E.; Larrondo, Luis F.; Loros, Jennifer J.; Dunlap, Jay C.

    2014-01-01

    The fungus Neurospora crassa constitutes an important model system extensively used in chronobiology. Several studies have addressed how environmental cues, such as light, can reset or synchronize a circadian system. By means of an optimized firefly luciferase reporter gene and a controllable lighting system, we show that Neurospora can display molecular circadian rhythms in dim light when cultures receive bright light prior to entering dim light conditions. We refer to this behavior as the “...

  5. Low-Surface-Brightness Galaxies: Hidden Galaxies Revealed

    Science.gov (United States)

    Bothun, G.; Impey, C.; McGaugh, S.

    1997-07-01

    In twenty years, low surface brightness (LSB) galaxies have evolved from being an idiosyncratic notion to being one of the major baryonic repositories in the Universe. The story of their discovery and the characterization of their properties is told here. Their recovery from the noise of the night sky background is a strong testament to the severity of surface brightness selection effects. LSB galaxies have a number of remarkable properties which distinguish them from the more familiar Hubble Sequence of spirals. The two most important are 1) they evolve at a significantly slower rate and may well experience star formation outside of the molecular cloud environment, 2) they are embedded in dark matter halos which are of lower density and more extended than the halos around high surface brightness (HSB) disk galaxies. Compared to HSB disks, LSB disks are strongly dark matter dominated at all radii and show a systematic increase in $M/L$ with decreasing central surface brightness. In addition, the recognition that large numbers of LSB galaxies actually exist has changed the form of the galaxy luminosity function and has clearly increased the space density of galaxies at z =0. Recent CCD surveys have uncovered a population of red LSB disks that may be related to the excess of faint blue galaxies detected at moderate redshifts. LSB galaxies offer us a new window into galaxy evolution and formation which is every bit as important as those processes which have produced easy to detect galaxies. Indeed, the apparent youth of some LSB galaxies suggest that galaxy formation is a greatly extended process. While the discovery of LSB galaxies have lead to new insights, it remains unwise to presume that we now have a representative sample which encompasses all galaxy types and forms. (SECTION: Invited Review Paper)

  6. English learners in the mathematics classroom

    CERN Document Server

    Coggins, Debra S (Susan)

    2014-01-01

    Research-based strategies to reach English learners - now aligned with the Common Core!Enable your English learners to build higher-level math skills and gain greater fluency in their new language-all while achieving the goals of the Common Core. Now in its second edition, this trusted resource includes:  Mathematics lesson scenarios in every chapter, directly connected to Common Core Standards and the Standards for Mathematical Practice Instructional approaches that promote participation, hands-on learning, and true comprehension of mathematics concepts that benefit ALL students Sample lessons, visuals, and essential vocabulary that connect mathematical concepts with language development.

  7. TEACHING ENGLISH TO YOUNG LEARNERS THROUGH SONGS

    Directory of Open Access Journals (Sweden)

    Yuliana Yuliana

    2003-01-01

    Full Text Available Teaching English to Young Learners has become a trend nowadays. In every school, English is taught as one of the main subjects. In teaching young learners is not like teaching adults, children have their own way of learning. Since children like to play and have fun, the learning and teaching process should be suited with the nature of the children themselves. One of the forms of fun activities for children is through music, and songs are the common form of music that children know. Through this paper, the writer wants to show that through songs, children could enhance their language skills, such as speaking, listening and writing.

  8. Teaching English to Young Learners Through Songs

    OpenAIRE

    Yuliana, Yuliana

    2003-01-01

    Teaching English to Young Learners has become a trend nowadays. In every school, English is taught as one of the main subjects. In teaching young learners is not like teaching adults, children have their own way of learning. Since children like to play and have fun, the learning and teaching process should be suited with the nature of the children themselves. One of the forms of fun activities for children is through music, and songs are the common form of music that children know. Through th...

  9. Work-life Experience and Learner Identity

    DEFF Research Database (Denmark)

    Kondrup, Sissel

    2013-01-01

    In order to examine how orientations toward learning activities are situated in and conditioned by specific work-life experiences it is crucial to develop a dialectic concept of learner identity. Based on a qualitative research-project (Kondrup 2012) this paper outlines how unskilled work forms...... a specific condition for engaging in lifelong learning. The aim of the study was to examine how an unskilled work-life presents certain conditions for the formation, maintenance and transformation of a learner identity, enabling workers to position themselves as educable subjects and engage in formal...

  10. Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — The Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperature product provides near-real-time brightness temperatures for both the Northern and...

  11. Educating English Learners: What Every Classroom Teacher Needs to Know

    Science.gov (United States)

    Nutta, Joyce W.; Strebel, Carine; Mokhtari, Kouider; Mihai, Florin M.; Crevecoeur-Bryant, Edwidge

    2014-01-01

    In "Educating English Learners," Joyce W. Nutta and her colleagues offer practical tools for helping schools and teachers successfully integrate English learners into mainstream classrooms. Drawing on the One Plus model presented in their award-winning book, "Preparing Every Teacher to Reach English Learners," the authors now…

  12. South African law and policy regulating learner absenteeism

    African Journals Online (AJOL)

    Packard Bell

    Learner absenteeism often occurs involuntarily due to learners' social and economic circumstances. ..... still a child; e.g. under 18 years of age, and ... schools to take the age and maturity of the ... 5). The Policy on Learner Attendance (DBE, RSA,. 2010, para. 13(i)) allows the ..... Emotional literacy and the ecology of.

  13. Which Dictionary? A Review of the Leading Learners' Dictionaries.

    Science.gov (United States)

    Nesi, Hilary

    Three major dictionaries designed for learners of English as a second language are reviewed, their elements and approaches compared and evaluated, their usefulness for different learners discussed, and recommendations for future dictionary improvement made. The dictionaries in question are the "Oxford Advanced Learner's Dictionary," the…

  14. Shopping [for] Power: How Adult Literacy Learners Negotiate the Marketplace

    Science.gov (United States)

    Ozanne, Julie L.; Adkins, Natalie Ross; Sandlin, Jennifer A.

    2005-01-01

    Little empirical evidence exists on how adult literacy learners act as consumers. Yet, adult literacy programs often employ a "functional" approach to consumer education and assume that adult learners are deficient in consumer skills. Data from a qualitative study of the consumer behaviors of adult literacy learners are used to explore how adult…

  15. Using Learner Corpora for L2 Lexicography: Information on ...

    African Journals Online (AJOL)

    In this paper, we describe an on-going project of the corpus of EFL (English as a Foreign Language) learners in Japan and its application for pedagogical dictionary compilation. We especially focus on the learners' errors in verb collocation patterns and describe how the leamer's dictionary can benefit from the learners' ...

  16. Advancing Learner Autonomy in TEFL via Collaborative Learning

    Science.gov (United States)

    Jacobs, George M.; Shan, Tan Hui

    2015-01-01

    The present paper begins by situating learner autonomy and collaborative learning as part of a larger paradigm shift towards student-centred learning. Next are brief discussions of learner autonomy and how learner autonomy links with collaborative learning. In the main part of the paper, four central principles of collaborative learning are…

  17. Language diversity in the mathematics classroom: does a learner ...

    African Journals Online (AJOL)

    In this study, the researchers developed an 'aid' that would assist learners to relate mathematics terms and concepts in English with terms in their own languages. The study determined whether a visual multilingual learner companion brought change in learners' performance in mathematics. Also what the educators' views ...

  18. Learners' experiences of learning support in selected Western Cape ...

    African Journals Online (AJOL)

    The learning support assisted in meeting learners' academic, social and emotional needs by addressing barriers to learning, creating conducive learning environments, enhancing learners' self-esteem and improving learners' academic performance. Keywords: academic needs; academic performance; barriers to learning; ...

  19. Young Learner Perspectives on Four Focus-on-Form Tasks

    Science.gov (United States)

    Shak, Juliana; Gardner, Sheena

    2008-01-01

    Recent studies suggest that focus-on-form (FonF) instruction has a positive effect on the second language proficiency of young learners. However, few have looked at learner perspectives on different FonF tasks, particularly in those young learners. This study investigates children's attitudes towards four FonF task-types in three Primary 5 English…

  20. An Investigation of Pronunciation Learning Strategies of Advanced EFL Learners

    Science.gov (United States)

    Hismanoglu, Murat

    2012-01-01

    This paper aims at investigating the kinds of strategies deployed by advanced EFL learners at English Language Teaching Department to learn or improve English pronunciation and revealing whether there are any significant differences between the strategies of successful pronunciation learners and those of unsuccessful pronunciation learners. After…

  1. Teaching strategies to support isiXhosa learners who receive ...

    African Journals Online (AJOL)

    how learners acquire learning, there is still a dearth of material on descriptions of current support provided to learners within the theoretical ... schools where the Language of Learning and Teaching (LOLT) is English and/or Afrikaans (i.e. the learner's second or third .... Languages (IIAL) policy for public comment. This.

  2. Dimensionality in Language Learners' Personal Epistemologies

    Science.gov (United States)

    Nikitina, Larisa; Furuoka, Fumitaka

    2018-01-01

    This study aimed to examine dimensionality in language learners' epistemic beliefs. To achieve this, a survey was conducted using a newly-developed research instrument-"Language Learners' Epistemic Beliefs" (LLEB) questionnaire. Based on a review of literature, it was proposed that language learners' epistemic beliefs would cluster in…

  3. Online Games for Young Learners' Foreign Language Learning

    Science.gov (United States)

    Butler, Yuko Goto; Someya, Yuumi; Fukuhara, Eiji

    2014-01-01

    Young learners' use of instructional games in foreign language learning is not yet well understood. Using games that were part of the learning tools for an online assessment, Jido-Eiken, a standardized English proficiency test for young learners in Japan, we examined young learners' game-playing behaviours and the relationship of these behaviours…

  4. The Evolving Military Learner Population: A Review of the Literature

    Science.gov (United States)

    Ford, Kate; Vignare, Karen

    2015-01-01

    This literature review examines the evolving online military learner population with emphasis on current generation military learners, who are most frequently Post-9/11 veterans. The review synthesizes recent scholarly and grey literature on military learner demographics and attributes, college experiences, and academic outcomes against a backdrop…

  5. Whose voice matters? LEARNERS | Bansilal | South African Journal ...

    African Journals Online (AJOL)

    International and national mathematics studies have revealed the poor mathematics skills of South African learners. An essential tool that can be used to improve learners' mathematical skills is for educators to use effective feedback. Our purpose in this study was to elicit learners' understanding and expectations of teacher ...

  6. Automatic Annotation Method on Learners' Opinions in Case Method Discussion

    Science.gov (United States)

    Samejima, Masaki; Hisakane, Daichi; Komoda, Norihisa

    2015-01-01

    Purpose: The purpose of this paper is to annotate an attribute of a problem, a solution or no annotation on learners' opinions automatically for supporting the learners' discussion without a facilitator. The case method aims at discussing problems and solutions in a target case. However, the learners miss discussing some of problems and solutions.…

  7. On correct evaluation techniques of brightness enhancement effect measurement data

    Science.gov (United States)

    Kukačka, Leoš; Dupuis, Pascal; Motomura, Hideki; Rozkovec, Jiří; Kolář, Milan; Zissis, Georges; Jinno, Masafumi

    2017-11-01

    This paper aims to establish confidence intervals of the quantification of brightness enhancement effects resulting from the use of pulsing bright light. It is found that the methods used so far may yield significant bias in the published results, overestimating or underestimating the enhancement effect. The authors propose to use a linear algebra method called the total least squares. Upon an example dataset, it is shown that this method does not yield biased results. The statistical significance of the results is also computed. It is concluded over an observation set that the currently used linear algebra methods present many patterns of noise sensitivity. Changing algorithm details leads to inconsistent results. It is thus recommended to use the method with the lowest noise sensitivity. Moreover, it is shown that this method also permits one to obtain an estimate of the confidence interval. This paper neither aims to publish results about a particular experiment nor to draw any particular conclusion about existence or nonexistence of the brightness enhancement effect.

  8. Bright Soil Churned by Spirit's Sol 1861 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit drove 22.7 meters (74 feet) toward the southwest on the 1,861st Martian day, or sol, of Spirit's mission on Mars (March 28, 2009). After the drive, the rover took this image with its front hazard-avoidance camera, looking back at the tracks from the drive. As usual since losing the use of its right-front wheel in 2006, Spirit drove backwards. The immobile right-front wheel churned up a long stripe of bright soil during this drive. Where Spirit has found such bright soil in the past, subsequent analysis of the composition found concentrations of sulfur or silica that testified to past action of water at the site. When members of the rover team saw the large quantity of bright soil exposed by the Sol 1861 drive, they quickly laid plans to investigate the composition with Spirit's alpha particle X-ray spectrometer. The Sol 1861 drive took the rover past the northwest corner of the low plateau called 'Home Plate,' making progress on a route around the western side of Home Plate. The edge of Home Plate forms the horizon on the right side of this image. Husband Hill is on the horizon on the left side. For scale, the parallel rover wheel tracks are about 1 meter (40 inches) apart. The rover's hazard-avoidance cameras take 'fisheye' wide-angle images.

  9. Inversion methods for analysis of neutron brightness measurements in tokamaks

    International Nuclear Information System (INIS)

    Gorini, G.; Gottardi, N.

    1990-02-01

    The problem of determining neutron emissivity from neutron brightness measurements in magnetic fusion plasmas is addressed. In the case of two-dimensional measurements with two orthogonal cameras, a complete, tomographic analysis of the data can in principle be performed. The results depend critically on the accuracy of the measurements and alternative solutions can be sought under the assumption of a known emissivity topology (Generalized Abel Inversion). In this work, neutron brightness data from the JET tokamak have been studied with both methods. We find that with the present experimental uncertainty (levels 10-20%) the Abel inversion method works best, while two-dimensional information cannot in general be deduced. This is confirmed by studies of the error propagation in the inversion using artificial data, which are also presented here. An important application of emissivity profile information is the determination of the plasma deuterium temperature profile, T D (R). Results are presented here from the analysis of JET data and the errors in T D (R) are discussed in some detail. It is found that, for typical JET plasma conditions, the dominant source of uncertainty arises from the high plasma impurity level and the fact that it is poorly known; these problems can be expected to be remedied and neutron brightness measurements would be expected to be very effective (especially in high density plasmas) as a T D (R) diagnostics. (author)

  10. SMOS brightness temperature assimilation into the Community Land Model

    Directory of Open Access Journals (Sweden)

    D. Rains

    2017-11-01

    Full Text Available SMOS (Soil Moisture and Ocean Salinity mission brightness temperatures at a single incident angle are assimilated into the Community Land Model (CLM across Australia to improve soil moisture simulations. Therefore, the data assimilation system DasPy is coupled to the local ensemble transform Kalman filter (LETKF as well as to the Community Microwave Emission Model (CMEM. Brightness temperature climatologies are precomputed to enable the assimilation of brightness temperature anomalies, making use of 6 years of SMOS data (2010–2015. Mean correlation R with in situ measurements increases moderately from 0.61 to 0.68 (11 % for upper soil layers if the root zone is included in the updates. A reduced improvement of 5 % is achieved if the assimilation is restricted to the upper soil layers. Root-zone simulations improve by 7 % when updating both the top layers and root zone, and by 4 % when only updating the top layers. Mean increments and increment standard deviations are compared for the experiments. The long-term assimilation impact is analysed by looking at a set of quantiles computed for soil moisture at each grid cell. Within hydrological monitoring systems, extreme dry or wet conditions are often defined via their relative occurrence, adding great importance to assimilation-induced quantile changes. Although still being limited now, longer L-band radiometer time series will become available and make model output improved by assimilating such data that are more usable for extreme event statistics.

  11. Three Bright X-ray Sources in NGC 1313

    Science.gov (United States)

    Colbert, E.; Petre, R.; Schlegel, E.

    1992-12-01

    Three bright X-ray sources were detected in a recent (April/May 1991) ROSAT PSPC observation of the nearby (D ~ 4.5 Mpc) face--on barred spiral galaxy NGC 1313. Two of the sources were at positions coincident with X-ray sources detected by Fabbiano & Trinchieri (ApJ 315, 1987) in a previous (Jan 1980) Einstein IPC observation. The position of the brightest Einstein source is near the center of NGC 1313, and the second Einstein source is ~ 7' south of the ``nuclear'' source, in the outskirts of the spiral arms. A third bright X-ray source was detected in the ROSAT observation ~ 7' southwest of the ``nuclear'' source. We present X-ray spectra and X-ray images for the three bright sources found in the ROSAT observation of NGC 1313, and compare with previous Einstein results. Spectral analysis of these sources require them to have very large soft X-ray luminosities ( ~ 10(40) erg s(-1) ) when compared with typical X-ray sources in our Galaxy. Feasible explanations for the X-ray emission are presented. The third X-ray source is positively identified with the recently discovered (Ryder et. al., ApJ 1992) peculiar type-II supernova 1978K.

  12. Speaking out on Behalf of the Voiceless Learners: Written Corrective Feedback for English Language Learners in Iran

    Science.gov (United States)

    Nemati, Majid; Alavi, Sayyed Mohammad; Mohebbi, Hassan; Masjedlou, Ali Panahi

    2017-01-01

    To date, L2 researchers have studied the effect of feedback on improving L2 learners' writing from different perspectives. However, there are a lot of aspects which are not comprehensively researched yet, such as L2 learners' and teachers' perceptions and practices about feedback. To close the gap, this study investigates language learners'…

  13. The Physics and Applications of High Brightness Electron Beams

    Science.gov (United States)

    Palumbo, Luigi; Rosenzweig, J.; Serafini, Luca

    2007-09-01

    Plenary sessions. RF deflector based sub-Ps beam diagnostics: application to FEL and advanced accelerators / D. Alesini. Production of fermtosecond pulses and micron beam spots for high brightness electron beam applications / S.G. Anderson ... [et al.]. Wakefields of sub-picosecond electron bunches / K.L.F. Bane. Diamond secondary emitter / I. Ben-Zvi ... [et al.]. Parametric optimization for an X-ray free electron laser with a laser wiggler / R. Bonifacio, N. Piovella and M.M. Cola. Needle cathodes for high-brightness beams / C.H. Boulware ... [et al.]. Non linear evolution of short pulses in FEL cascaded undulators and the FEL harmonic cascade / L. Giannessi and P. Musumeci. High brightness laser induced multi-meV electron/proton sources / D. Giulietti ... [et al.]. Emittance limitation of a conditioned beam in a strong focusing FEL undulator / Z. Huang, G. Stupakov and S. Reiche. Scaled models: space-charge dominated electron storage rings / R.A. Kishek ... [et al.]. High brightness beam applications: energy recovered linacs / G.A. Krafft. Maximizing brightness in photoinjectors / C. Limborg-Deprey and H. Tomizawa. Ultracold electron sources / O.J. Luiten ... [et al.]. Scaling laws of structure-based optical accelerators / A. Mizrahi, V. Karagodsky and L. Schächter. High brightness beams-applications to free-electron lasers / S. Reiche. Conception of photo-injectors for the CTF3 experiment / R. Roux. Superconducting RF photoinjectors: an overview / J. Sekutowicz. Status and perspectives of photo injector developments for high brightness beams / F. Stephan. Results from the UCLA/FNLP underdense plasma lens experiment / M.C. Thompson ... [et al.]. Medical application of multi-beam compton scattering monochromatic tunable hard X-ray source / M. Uesaka ... [et al.]. Design of a 2 kA, 30 fs RF-photoinjector for waterbag compression / S.B. Van Der Geer, O.J. Luiten and M.J. De Loos. Proposal for a high-brightness pulsed electron source / M. Zolotorev ... [et al

  14. Second Language Learners' Use of Marginal Glosses

    Science.gov (United States)

    O'Donnell, Mary E.

    2012-01-01

    The use of marginal reading glosses by 18 second language (L2) learners is examined through a quantitative and qualitative analysis of audiotaped think-aloud protocols. How these readers interact with the glosses is identified and divided into five categories or gloss interactions. Examples from each are presented. The primary research question…

  15. Rights of Postsecondary Readers and Learners

    Science.gov (United States)

    Greenbaum, JoAnne; Angus, Kathryn Bartle

    2018-01-01

    A position statement on the rights of adult readers and learners was adopted by the CRLA board in 2002 and published with a theoretical rationale in ["Journal of College Reading and Learning"] "JCRL," Spring 2003. The statement was a guideline for educators seeking to improve the quality of adult education. In 2016, at the…

  16. Exploring Linguistic Identity in Young Multilingual Learners

    Science.gov (United States)

    Dressler, Roswita

    2014-01-01

    This article explores the linguistic identity of young multilingual learners through the use of a Language Portrait Silhouette. Examples from a research study of children aged 6-8 years in a German bilingual program in Canada provide teachers with an understanding that linguistic identity comprises expertise, affiliation, and inheritance. This…

  17. Second Language Learners' Attitudes towards English Varieties

    Science.gov (United States)

    Zhang, Weimin; Hu, Guiling

    2008-01-01

    This pilot project investigates second language (L2) learners' attitudes towards three varieties of English: American (AmE), British (BrE) and Australian (AuE). A 69-word passage spoken by a female speaker of each variety was used. Participants were 30 Chinese students pursuing Masters or Doctoral degrees in the United States, who listened to each…

  18. Educational Transition of East Malaysian Distance Learners.

    Science.gov (United States)

    Saw, K. G.; Awang, M. N.; Idrus, R. M.; Atan, H.; Azli, N. A.; Jaafar, I.; Rahman, Z. A.; Latiff, Z. A.

    1999-01-01

    Describes results of a study of the changing perceptions of East Malaysian distance learners studying at the Universiti Sains Malaysia. Highlights include students' perceptions of their study skills; and the impact of their studies on other areas of their life, including social obligations, recreation, families, health, finances, work, and…

  19. Tracking the Progress of English Language Learners

    Science.gov (United States)

    Murphy, Audrey F.

    2009-01-01

    Educators need to document progress for English language learners, and the best structures to put into place in order to record their growth. Beginning with the stages of language proficiency, student progress can be tracked through the use of a baseline in all four language strands and the creation of rubrics to monitor performance. Language…

  20. Contextualized Workforce Skills and ESL Learner Identity

    Science.gov (United States)

    Vafai, Maliheh Mansuripur

    2016-01-01

    This article reports on an empirical case study centering on adult ESL learners' motivational patterns for learning English and its relevance to their career goals. It looks at past patterns of immigrant insertion within the socioeconomic context of the US and explores current trends in adult ESL curriculum development focused on the task of…

  1. Bilingualised Dictionaries: How Learners Really Use Them.

    Science.gov (United States)

    Laufer, Batia; Kimmel, Michal

    1997-01-01

    Seventy native Hebrew-speaking English-as-a-Second-Language students participated in a study that investigated what part of an entry second-language learners read when they look up an unfamiliar word in a bilingualised dictionary: the monolingual, the bilingual, or both. Results suggest the bilingualised dictionary is very effective because it is…

  2. Learner Ownership of Technology-Enhanced Learning

    Science.gov (United States)

    Dommett, Eleanor J.

    2018-01-01

    Purpose: This paper aims to examine the different ways in which learners may have ownership over technology-enhanced learning by reflecting on technical, legal and psychological ownership. Design/methodology/approach: The paper uses a variety of examples of technology-enhanced learning ranging from open-source software to cloud storage to discuss…

  3. Maximing Learning Strategies to Promote Learner Autonomy

    Directory of Open Access Journals (Sweden)

    Junaidi Mistar

    2001-01-01

    Full Text Available Learning a new language is ultimately to be able to communicate with it. Encouraging a sense of responsibility on the part of the learners is crucial for training them to be proficient communicators. As such, understanding the strategies that they employ in acquiring the language skill is important to come to ideas of how to promote learner autonomy. Research recently conducted with three different groups of learners of English at the tertiary education level in Malang indicated that they used metacognitive and social startegies at a high frequency, while memory, cognitive, conpensation, and affective strategies were exercised at a medium frewuency. This finding implies that the learners have acquired some degrees of autonomy because metacognive strategies requires them to independently make plans for their learning activities as well as evaluate the progress, and social strategies requires them to independently enhance communicative interactions with other people. Further actions are then to be taken increase their learning autonomy, that is by intensifying the practice of use of the other four strategy categories, which are not yet applied intensively.

  4. Hindsight of an English Language Learner.

    Science.gov (United States)

    Dam, Phap

    This keynote address by a native Vietnamese speaker who did not learn English until he was college-age, through the now obsolete "grammar-translation" method, recounts his difficulties in learning to converse orally in English. He stresses the need to teach conversational English to English Language Learners (ELLs) in addition to…

  5. Preparing English Language Learners for Complex Reading

    Science.gov (United States)

    Silva, Janice; Delleman, Paul; Phesia, Andria

    2013-01-01

    Although the Common Core state standards' goal of ensuring that every student leaves high school prepared to meet the demands of college and career is laudable, it's daunting for teachers who serve English language learners. The authors, educators at a private bilingual school in Mexico, describe how they used short excerpts of longer works giving…

  6. Teaching Mathematics That Addresses Learners' Multiple Intelligences

    Science.gov (United States)

    Gouws, E.; Dicker, A-M.

    2011-01-01

    To meet the demands of our highly technological and globally competitive society, it is becoming increasingly important for all learners in South Africa to obtain skills and knowledge in mathematics. However, South Africa performed the worst of all the countries who participated in the Trends in International Mathematics and Science Study (TIMMS).…

  7. Games for and by Teachers and Learners

    NARCIS (Netherlands)

    Van Rosmalen, Peter; Wilson, Amanda; Hummel, Hans

    2013-01-01

    With the advent of social media it is widely accepted that teachers and learners are not only consumers but also may have an active role in contributing and co-creating lesson materials and content. Paradoxically one strand of technology enhanced learning, i.e. game-based learning, aligns only

  8. Adult Learners: Considerations for Education and Training

    Science.gov (United States)

    Kistler, Mark J.

    2011-01-01

    As more and more adults seek out education and training programs to help them become more competitive in the job market, it provides an opportunity for career and technical education. Those who teach adult learners should take into consideration their particular learning traits. This article highlights a framework of core principles to be…

  9. Researching Oral Production Skills of Young Learners

    Science.gov (United States)

    Szpotowicz, Magdalena

    2012-01-01

    This chapter focuses on the development of young learners' ability to communicate in a foreign language. An empirical study was carried out to determine whether, after four years of learning English as a compulsory school subject, children are ready to engage in oral interaction in a semi-controlled task and produce answers and questions in…

  10. Exploring educators' understanding of developing learners' reading ...

    African Journals Online (AJOL)

    This study explored what three Intermediate Phase English First Additional Language teachers understood about reading and teaching reading, and the strategies they used to develop learners' reading skills. Data gathered through interviews and observations of classroom practice were used to consider the extent of their ...

  11. Workplace Learning in Malaysia: The Learner's Perspective

    Science.gov (United States)

    Muhamad, Mazanah; Idris, Khairuddin

    2005-01-01

    This paper offers a scenario of workplace learning as practiced in Malaysia. Based on survey research, the article describes learner profiles, learning provision and pattern. The analysis shows that Malaysians participate in formal workplace learning as part of their employment activities. Workplace learning in Malaysia is contextual, promoted by…

  12. BENCHMARKING LEARNER EDUCATION USING ONLINE BUSINESS SIMULATION

    Directory of Open Access Journals (Sweden)

    Alfred H. Miller

    2016-06-01

    Full Text Available For programmatic accreditation by the Accreditation Council of Business Schools and Programs (ACBSP, business programs are required to meet STANDARD #4, Measurement and Analysis of Student Learning and Performance. Business units must demonstrate that outcome assessment systems are in place using documented evidence that shows how the results are being used to further develop or improve the academic business program. The Higher Colleges of Technology, a 17 campus federal university in the United Arab Emirates, differentiates its applied degree programs through a ‘learning by doing ethos,’ which permeates the entire curricula. This paper documents benchmarking of education for managing innovation. Using business simulation for Bachelors of Business, Year 3 learners, in a business strategy class; learners explored through a simulated environment the following functional areas; research and development, production, and marketing of a technology product. Student teams were required to use finite resources and compete against other student teams in the same universe. The study employed an instrument developed in a 60-sample pilot study of business simulation learners against which subsequent learners participating in online business simulation could be benchmarked. The results showed incremental improvement in the program due to changes made in assessment strategies, including the oral defense.

  13. Learners for life : student approaches to learning

    NARCIS (Netherlands)

    Artelt, Cordula; Baumert, Jürgen; Julius-McElvany, Nele; Peschar, Jules

    2003-01-01

    What are students like as learners as they approach the end of compulsory education? The answer matters greatly, not only because those with stronger approaches to learning get better results at school but also because young adults able to set learning goals and manage their own learning are much

  14. Reading Interventions to Support English Language Learners

    Science.gov (United States)

    Corella, Jolene

    2012-01-01

    High stakes assessments conducted in the southwestern United States demonstrate that fewer than 50% of English language learners (ELLs) are achieving proficiency levels in reading fluency. The purpose of this study was to understand if reading interventions using the framework of Samuels's repeated reading (RR) strategy increased student…

  15. Discrimination of Arabic Contrasts by American Learners

    Science.gov (United States)

    Al Mahmoud, Mahmoud S.

    2013-01-01

    This article reports on second language perception of non-native contrasts. The study specifically tests the perceptual assimilation model (PAM) by examining American learners' ability to discriminate Arabic contrasts. Twenty two native American speakers enrolled in a university level Arabic language program took part in a forced choice AXB…

  16. "Becoming" Learners/Teachers in Nomadic Space

    Science.gov (United States)

    Gorodetsky, Malka; Barak, Judith

    2016-01-01

    This paper suggests a conjunction between the learning space of educational edge community (EEC) and the Deleuzeguattarian thought regarding the nature of teachers' "becoming." It attends to the emerging subjectivities of teachers/learners within an EEC, a nomadic, open, and smooth space of learning. It is suggested that autonomous…

  17. Language Anxiety among Gifted Learners in Malaysia

    Science.gov (United States)

    Kamarulzaman, Mohd Hasrul; Ibrahim, Noraniza; Yunus, Melor Md; Ishak, Noriah Mohd

    2013-01-01

    Language anxiety has significantly sparked great concern in the second and foreign language learning world. Researches have found negative correlation between language anxiety and academic achievement of English language learners; and, most of the studies focus on average school students and tertiary level students. This paper, however, explores…

  18. Teaching Science to Learners with Special Needs

    Science.gov (United States)

    McGinnis, J. Randy

    2013-01-01

    A fundamental social justice issue worldwide is how to meet the needs of all learners, especially those with special needs who historically have faced discrimination, exclusion, and oppression due to special needs (physical, cognitive, or behavioral dimensions). This article focuses on the key questions that researchers interested in improving…

  19. Internet Anxiety among Foreign Language Learners

    Science.gov (United States)

    Aydin, Selami

    2011-01-01

    Little attention has been paid to the demotivating potential of new technologies in foreign language research. Thus, this study aims to investigate Internet anxiety among foreign language learners and to determine the relationships between Internet anxiety and certain variables. A background questionnaire, an Internet information test, and an…

  20. Comparison of Learner Involvement in Biology Laboratory ...

    African Journals Online (AJOL)

    Performance in the biology practical paper has been poor at Kenya national examinations in the past five years (1998-2002). This may imply a lack of emphasis on the teaching of biology through the process-based approach. This study investigated the level of learner involvement in biology practical investigations in ...

  1. Learners' right to freedom of written expression

    African Journals Online (AJOL)

    Erna Kinsey

    Learners' right to freedom of written expression. W.J. van Vollenhoven. Department of Education Management and Policy Studies, University of Pretoria, Pretoria, 0002 South Africa wvvollen@postino.up.ac.za. Charles I. Glenn. Training and Policy Studies of the University Professors' Program, University of Boston. Although ...

  2. Motivating Learners at South Korean Universities

    Science.gov (United States)

    Niederhauser, Janet S.

    2012-01-01

    Students at many universities often fail to reach their full potential as English language learners due to low motivation. Some of the factors that affect their motivation relate to the country's education system in general. Others reflect institutional and cultural views of language learning in particular. Using a problem-solution format, this…

  3. Fairness in Assessment of English Learners

    Science.gov (United States)

    Abedi, Jamal; Levine, Harold G.

    2013-01-01

    English language learners (ELLs) face a challenging academic future in learning a new language while simultaneously mastering content in the language they may be struggling to learn. Assessment plays an extremely important role in the academic careers of ELL students, perhaps more so than for native speakers of English. Major changes and…

  4. System Approach to Pedagogical Discourse: CLD Learners

    Science.gov (United States)

    Rojas, Eliana D.; Avitia, Maria J.

    2017-01-01

    This paper examines the achievement gap for culturally and linguistically diverse (CLD) learners through the lens of Bronfenbrenner's bioecological theory of human development. The population of CLD students in the United States continues to grow. Across the nation, CLD students continue to struggle in an increasingly accountability-based…

  5. EFL Learner Collaborative Interaction in Second Life

    Science.gov (United States)

    Peterson, Mark

    2012-01-01

    This paper reports on the task-based interaction of English as a Foreign Language (EFL) learners in the 3D multiuser virtual environment (MUVE) Second Life. The discussion first explores research on the precursors of MUVEs, text-based 2D virtual worlds known as MOOs. This is followed by an examination of studies on the use of MUVEs in Computer…

  6. Translanguaging and the Writing of Bilingual Learners

    Science.gov (United States)

    Velasco, Patricia; García, Ofelia

    2014-01-01

    This article makes the case for using translanguaging in developing the academic writing of bilinguals. It reviews the emerging literature on learning and teaching theories of translanguaging and presents theoretical understandings of biliteracy development and specifically on the teaching of writing to bilingual learners. The article analyzes…

  7. Distinctiveness of Saudi Arabian EFL Learners

    Science.gov (United States)

    Habbash, Manssour; Idapalapati, Srinivasa Rao

    2016-01-01

    In view of the increasing concern among English language teachers dealing with students from Saudi Arabia, as it manifests in TESOL community discussions, about the uniqueness of Saudi Arabian EFL learners, this paper attempts to document the outcome of a study of their distinctiveness from the perspective of expatriate teachers working for PYPs…

  8. Topic Prominence in Chinese EFL Learners' Interlanguage

    Science.gov (United States)

    Li, Shaopeng; Yang, Lianrui

    2014-01-01

    The present study aims to investigate the general characteristics of topicprominent typological interlanguage development of Chinese learners of English in terms of acquiring subject-prominent English structures from a discourse perspective. Topic structures mainly appear in Chinese discourse in the form of topic chains (Wang, 2002; 2004). The…

  9. Correlates of parental influence, school environment, learners ...

    African Journals Online (AJOL)

    The study examined the predicting effects of parental influence, school environment, Learners\\' interest, and self–efficacy on academic performance of police children in Ibadan Metropolis, Oyo state, Nigeria. The sample consisted of 200 primary IV, V and VI pupils (Mean age = 9 years). The results of the multiple regression ...

  10. Teaching Vocabulary to English Language Learners

    Science.gov (United States)

    Daniels, Sharilyn Fox

    2009-01-01

    This study determined if the vocabulary gap for English Language Learners (ELLs) and their peers could be bridged through providing home interventions with multiple exposures to words, definitions, model sentences and context. Ninety-one first grade students from a public school in Southern California with a 95% ELL population were researched. ELL…

  11. Working with Bilingual Learners: An Introduction

    Science.gov (United States)

    Willenberg, Ingrid

    2015-01-01

    This article seeks to provide a theoretical overview of bilingualism and discuss the key concepts and theories that inform classroom pedagogy with bilingual learners. Although some specific classroom strategies are introduced, the primary purpose is not to offer strategies, but rather to offer guiding principles based on theory and research to…

  12. Development of affective modelling competencies in primary school learners

    Directory of Open Access Journals (Sweden)

    Piera Biccard

    2011-09-01

    Full Text Available Learner affect and beliefs about mathematics are complex and multifaceted aspects of mathematical learning. Traditional teaching and learning approaches in mathematics education often result in problematic beliefs about mathematics. Since beliefs influence what learners learn and how they deal with learning mathematics, it is essential that the roles of beliefs and affect in mathematics classrooms are carefully examined. In solving modelling problems, learners and teachers take on new roles in the classroom: learners are placed in an active, self-directing situation in which they solve real-world problems. When learners engage in modelling tasks, they display and integrate cognitive, meta-cognitive and affective competencies. A modelling approach therefore allows one to detect learner beliefs in an authentic learning environment. Will this environment lead to students having more positive and productive dispositions towards mathematics? This article presents partial results of a study documenting the development of modelling competencies in learners working in groups over a period of 12 weeks. Through a design research approach, 12 learners working in groups solved three modelling problems, and transcriptions of learner interactions, questionnaires and informal interviews revealed that learner beliefs improved over this short period when exposed to modelling tasks. The results are encouraging, and may provide mathematics education with an avenue to develop more positive learner beliefs in mathematics.

  13. THE ELUSIVENESS OF LEARNER-CENTRED TEACHING

    Directory of Open Access Journals (Sweden)

    Ervin Kovačević

    2016-03-01

    Full Text Available This research will explore teaching styles of university professors. Teaching style is an umbrella term for teaching decisions made during the entire teaching process – planning, delivery, and evaluation. Contemporary university teachers are advised to adopt the learner-centred teaching style which is assumed to produce remarkable possibilities. In the Fall Semester 2015 fifty-two respondents in different faculties of International University of Sarajevo were surveyed using The Principles of Adult Learning Scale inventory designed by Gary J. Conti. Inventory scores were calculated according to guidelines suggested by the author of the inventory. The scores revealed that majority of respondents strongly supported teacher-centred rather than learner-centred styles of instruction. Scores were analysed on gender lines and across three different faculties, namely: Arts and Social Sciences; Business and Administration; Engineering and Natural Sciences. In all five groups none of the seven teaching style indicators was found to conform with the learner-centred teaching criteria. There was no statistically significant difference between the two genders’ preference for a teaching style. And there was no statistically significant difference between teaching style preference across the three different faculties.The results of this research imply that the learner-centred style of instruction is not frequently implemented. Secondly, the results indicate that the requirements necessary for proper application of the learner-centred teaching style are not easy to meet in current written and unwritten norms. Finally, the results show that traditional teaching styles, which have been preserved in different scientific fields, still predominate in universities.

  14. Variation reduction of brightness and pH of pulp sent to a paper mill

    Directory of Open Access Journals (Sweden)

    Napassavong Rojanarowan

    2015-03-01

    Full Text Available The variance of the brightness of pulp sent to the paper mill during the changing period of dry pulp grades affects the chemical control in the paper mill. This research aims to determine the mixing formula of pulp with different brightness from the EOP and D1 stages to handle this variation issue. This research uses response surface design with Central Composite Design type, regression technique and optimization technique to find the optimal setting of the mixing formula for each of the seven brightness levels to obtain the target brightness of 86% and the pH of 5.25. The mixing formulas are determined by the pulp mixing percentage and the sulfuric acid consumption. The experimental results reveal that when using higher EOP mixing ratio, the brightness decreases and the pH increases. Regarding the effect of the sulfuric acid, increasing the sulfuric acid makes the brightness and the pH decrease. After implementing the optimal formula in the production line, the mean of pulp brightness is closer to the target compared with the brightness before improvement and the brightness variation decreases without affecting the quality of other pulp grades, average of brightness decreased from 87.4% to 86.3% and standard deviation of brightness decreased from 1.09 to 0.46.

  15. Flux and brightness calculations for various synchrotron radiation sources

    International Nuclear Information System (INIS)

    Weber, J.M.; Hulbert, S.L.

    1991-11-01

    Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring

  16. Low surface brightness galaxies in the Fornax Cluster: automated galaxy surface photometry

    International Nuclear Information System (INIS)

    Davies, J.I.; Phillipps, S.; Disney, M.J.

    1988-01-01

    A sample is presented of low surface brightness galaxies (with extrapolated central surface brightness fainter than 22.0 Bμ) in the Fornax Cluster region which has been measured by the APM machine. Photometric parameters, namely profile shape, scale length, central brightness and total magnitude, are derived for the sample galaxies and correlations between the parameters of low surface brightness dwarf galaxies are discussed, with particular reference to the selection limits. Contrary to previous authors we find no evidence for a luminosity-surface brightness correlation in the sense of lower surface brightness galaxies having lower luminosities and scale sizes. In fact, the present data suggest that it is the galaxies with the largest scale lengths which are more likely to be of very low surface brightness. In addition, the larger scale length galaxies occur preferentially towards the centre of the Cluster. (author)

  17. Bright, dark and singular optical solitons in a cascaded system

    International Nuclear Information System (INIS)

    Zhou, Qin; Zhu, Qiuping; Yu, Hua; Liu, Yaxian; Wei, Chun; Yao, Ping; Bhrawy, Ali H; Biswas, Anjan

    2015-01-01

    This work studies nonlinear dynamics of optical solitons in a cascaded system with Kerr law nonlinearity and spatio-temporal dispersion. The mathematical model that describes the propagation of optical solitons through a cascaded system is given by the vector-coupled nonlinear Schrödinger equation. It is investigated analytically using three integration algorithms. The Jacobian elliptic equation expansion method, Bernoulli equation expansion approach and Riccati equation expansion scheme are the integration tools of this model that are recruited to extract singular, bright and dark solitons. The restrictions that need to hold for the existence of these solitons are derived. (paper)

  18. The bright optical afterglow of the long GRB 001007

    DEFF Research Database (Denmark)

    Ceron, J.M.C.; Castro-Tirado, A.J.; Gorosabel, J.

    2002-01-01

    We present optical follow up observations of the long GRB 001007 between 6.14 hours and similar to468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light...... curve at t - t(0) hours after the gamma ray event provide tentative (1.2σ) evidence for a break in the optical light curve. The spectral index β of the OA yields -1.24 +/- 0.57. These values may be explained both...

  19. Bright X-ray transient in the LMC

    Science.gov (United States)

    Saxton, R.; Read, A. M.; Li, D. Y.

    2018-01-01

    We report a bright X-ray transient in the LMC from an XMM-Newton slew made on 5th January 2018. The source, XMMSL2 J053629.4-675940, had a soft X-ray (0.2-2 keV) count rate in the EPIC-pn detector, medium filter of 1.82+/-0.56 c/s, equivalent to a flux Fx=2.3+/-0.7E-12 ergs/s/cm2 for a nominal spectrum of a power-law of slope 2 absorbed by a column NH=3E20 cm^-2.

  20. Technological Challenges for High-Brightness Photo-Injectors

    CERN Multimedia

    Suberlucq, Guy

    2004-01-01

    Many applications, from linear colliders to free-electron lasers, passing through light sources and many other electron sources, require high brightness electron beams, usually produced by photo-injectors. Because certain parameters of these applications differ by several orders of magnitude, various solutions were implemented for the design and construction of the three main parts of the photo-injectors: lasers, photocathodes and guns. This paper summarizes the different requirements, how they lead to technological challenges and how R&D programs try to overcome these challenges. Some examples of state-of-the-art parts are presented.

  1. Bright photoactivatable fluorophores for single-molecule imaging.

    Science.gov (United States)

    Grimm, Jonathan B; English, Brian P; Choi, Heejun; Muthusamy, Anand K; Mehl, Brian P; Dong, Peng; Brown, Timothy A; Lippincott-Schwartz, Jennifer; Liu, Zhe; Lionnet, Timothée; Lavis, Luke D

    2016-12-01

    Small-molecule fluorophores are important tools for advanced imaging experiments. We previously reported a general method to improve small, cell-permeable fluorophores which resulted in the azetidine-containing 'Janelia Fluor' (JF) dyes. Here, we refine and extend the utility of these dyes by synthesizing photoactivatable derivatives that are compatible with live-cell labeling strategies. Once activated, these derived compounds retain the superior brightness and photostability of the JF dyes, enabling improved single-particle tracking and facile localization microscopy experiments.

  2. Completion of the brightness upgrade of the ALS

    International Nuclear Information System (INIS)

    Steier, C; Madur, A; Bailey, B; Berg, K; Biocca, A; Black, A; Casey, P; Colomb, D; Gunion, B; Li, N; Marks, S; Nishimura, H; Pappas, C; Petermann, K; Portmann, G; Prestemon, S; Rawlins, A; Robin, D; Rossi, S; Scarvie, T

    2014-01-01

    The Advanced Light Source (ALS) at Berkeley Lab remains one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade [1], which reduces the horizontal emittance from 6.3 to 2.0 nm (2.5 nm effective). Magnets for this upgrade were installed in late 2012 and early 2013 followed by user operation with the reduced emittance.

  3. Generation of high brightness ion beam from insulated anode PED

    International Nuclear Information System (INIS)

    Matsukawa, Yoshinobu

    1988-01-01

    Generation and focusing of a high density ion beam with high brightness from a organic center part of anode of a PED was reported previously. Mass, charge and energy distribution of this beam were analyzed. Three kind of anode were tried. Many highly ionized medium mass ions (up to C 4+ , O 6+ ) accelarated to several times of voltage difference between anode and cathode were observed. In the case of all insulator anode the current carried by the medium mass ions is about half of that carried by protons. (author)

  4. FACT — LONGTERM MONITORING OF BRIGHT TeV BLAZARS

    Directory of Open Access Journals (Sweden)

    Katja Meier

    2014-06-01

    Full Text Available The First G-APD Cherenkov Telescope (FACT, located on the Canary Island of La Palma, has been taking data since October 2011. FACT has been optimized for longterm monitoring of bright TeV blazars, to study their variability time scales and flare probability. G-APD photo-sensors allow for observations even under strong moonlight conditions, and the telescope can be operated remotely. The monitoring strategy of FACT is discussed and preliminary results of the flare of Mrk501 in June 2012 are shown.

  5. Automatic brightness control algorithms and their effect on fluoroscopic imaging

    International Nuclear Information System (INIS)

    Quinn, P.W.; Gagne, R.M.

    1989-01-01

    This paper reports a computer model used to investigate the effect on dose and image quality of three automatic brightness control (ABC) algorithms used in the imaging of barium during general-purpose fluoroscopy. A model incorporating all aspects of image formation - i.e., x- ray production, phantom attenuation, and energy absorption in the CSI phosphor - was driven according to each ABC algorithm as a function of patient thickness. The energy absorbed in the phosphor was kept constant, while the changes in exposure, integral dose, organ dose, and contrast were monitored

  6. The role of the second zero-dispersion wavelength in generation of supercontinua and bright-bright soliton-pairs across the zero-dispersion wavelength: erratum

    DEFF Research Database (Denmark)

    Frosz, Michael Henoch; Falk, Peter Andreas; Bang, Ole

    2007-01-01

    An erratum is presented explaining that the observation in the original paper (Optics Express, volume 13, issue 16, page 6181-6192, 2005), of a bright-bright soliton with one color in the anomalous dispersion region and the other color in the normal dispersion region was mistaken; both parts...

  7. TOWARDS UNDERSTANDING THE SUCCESSFUL LEARNER: A Case Study of IGNOU

    Directory of Open Access Journals (Sweden)

    Sindhu P. NAIR

    2012-04-01

    Full Text Available The growth of enrolment in the ODL system has been considerable. However, another parameter of significance in the context of Open and Distance learning is the learner success rate. While enrolment rates have been very encouraging in distance education, the pass-out rates haven’t been similar. There is a need to focus on the dynamics involved after a learner enrols himself in an OU and what drives him to stay focussed and complete his academic pursuit successfully or alternatively what holds or slows his academic progress and eventually makes him drop out. The study highlights that there are both institution-based (that is OU-based and learner-centric factors that could facilitate learners to successfully complete their studies. There are both controllable and uncontrollable factors that affect the OU learners’ success rate. This study attempts to capture the learner-centric factors and OU-related factors that have facilitated the learners to successfully complete their study. The paper delves into those key aspects or factors which would have facilitated the passed out learners in successfully completing their programmes in the open system. The findings are of direct interest, both from an institution perspective and that of a distance learner. It provides inputs to the Open and distance learning system, towards formulating appropriate strategies that further facilitate learners to successfully pass out. Also the findings serve as indicators/guide rules for any learner in the open system.

  8. Observations of Bright Massive Stars Using Small Size Telescopes

    Science.gov (United States)

    Beradze, Sopia; Kochiashvili, Nino

    2017-11-01

    The size of a telescope determines goals and objects of observations. During the latest decades it becomes more and more difficult to get photometric data of bright stars because most of telescopes of small sizes do not operate already. But there are rather interesting questions connected to the properties and evolution ties between different types of massive stars. Multi-wavelength photometric data are needed for solution of some of them. We are presenting our observational plans of bright Massive X-ray binaries, WR and LBV stars using a small size telescope. All these stars, which are presented in the poster are observational targets of Sopia Beradze's future PhD thesis. We already have got very interesting results on the reddening and possible future eruption of the massive hypergiant star P Cygni. Therefore, we decided to choose some additional interesting massive stars of different type for future observations. All Massive stars play an important role in the chemical evolution of galaxies because of they have very high mass loss - up to 10-4M⊙/a year. Our targets are on different evolutionary stages and three of them are the members of massive binaries. We plan to do UBVRI photometric observations of these stars using the 48 cm Cassegrain telescope of the Abastumani Astrophisical Observatory.

  9. Unveiling the Low Surface Brightness Stellar Peripheries of Galaxies

    Science.gov (United States)

    Ferguson, Annette M. N.

    2018-01-01

    The low surface brightness peripheral regions of galaxies contain a gold mine of information about how minor mergers and accretions have influenced their evolution over cosmic time. Enormous stellar envelopes and copious amounts of faint tidal debris are natural outcomes of the hierarchical assembly process and the search for and study of these features, albeit highly challenging, offers the potential for unrivalled insight into the mechanisms of galaxy growth. Over the last two decades, there has been burgeoning interest in probing galaxy outskirts using resolved stellar populations. Wide-field surveys have uncovered vast tidal debris features and new populations of very remote globular clusters, while deep Hubble Space Telescope photometry has provided exquisite star formation histories back to the earliest epochs. I will highlight some recent results from studies within and beyond the Local Group and conclude by briefly discussing the great potential of future facilities, such as JWST, Euclid, LSST and WFIRST, for major breakthroughs in low surface brightness galaxy periphery science.

  10. Bright PanSTARRS Nuclear Transients – what are they?

    Directory of Open Access Journals (Sweden)

    Smartt S.

    2012-12-01

    Full Text Available We present an initial analysis of 49 bright transients occurring in the nuclei of galaxies with no previous known Active Galactic Nucleus (AGN. They have been discovered as part of the PanSTARRs 3π survey, and followed up with the Liverpool Telescope. Based on colours, light curve shape, and a small number with optical spectra, these transients seem to fall into three groups. Red/fast transients are nuclear supernovae of various types. Some bright nuclear transients are blue and decay on a timescale of a few months; these may be candidates for tidal disruption events. However most of the events we have found are blue and are either still rising or decaying slowly, on a timescale of years; the few spectra we have show AGN at z ∼ 1. We argue that these transients are background AGN microlensed by stars in foreground galaxies by a factor 10–100. Monitoring such events gives us very promising prospects for measuring the structure of AGN and so testing current theories.

  11. IRAS surface brightness maps of reflection nebulae in the Pleiades

    Science.gov (United States)

    Castelaz, Michael W.; Werner, M. W.; Sellgren, K.

    1987-01-01

    Surface brightness maps at 12, 25, 60, and 100 microns were made of a 2.5 deg x 2.5 deg area of the reflection nebulae in the Pleiades by coadding IRAS scans of this region. Emission is seen surrounding 17 Tau, 20 Tau, 23 Tau, and 25 Tau in all four bands, coextensive with the visible reflection nebulosity, and extending as far as 30 arcminutes from the illuminating stars. The infrared energy distributions of the nebulae peak in the 100 micron band, but up to 40 percent of the total infrared power lies in the 12 and 25 micron bands. The brightness of the 12 and 25 micron emission and the absence of temperature gradients at these wavelengths are inconsistent with the predictions of equilibrium thermal emission models. The emission at these wavelengths appears to be the result of micron nonequilibrium emission from very small grains, or from molecules consisting of 10-100 carbon atoms, which have been excited by ultraviolet radiation from the illuminating stars.

  12. Bright Solitons in a PT-Symmetric Chain of Dimers

    Directory of Open Access Journals (Sweden)

    Omar B. Kirikchi

    2016-01-01

    Full Text Available We study the existence and stability of fundamental bright discrete solitons in a parity-time- (PT- symmetric coupler composed by a chain of dimers that is modelled by linearly coupled discrete nonlinear Schrödinger equations with gain and loss terms. We use a perturbation theory for small coupling between the lattices to perform the analysis, which is then confirmed by numerical calculations. Such analysis is based on the concept of the so-called anticontinuum limit approach. We consider the fundamental onsite and intersite bright solitons. Each solution has symmetric and antisymmetric configurations between the arms. The stability of the solutions is then determined by solving the corresponding eigenvalue problem. We obtain that both symmetric and antisymmetric onsite mode can be stable for small coupling, in contrast to the reported continuum limit where the antisymmetric solutions are always unstable. The instability is either due to the internal modes crossing the origin or the appearance of a quartet of complex eigenvalues. In general, the gain-loss term can be considered parasitic as it reduces the stability region of the onsite solitons. Additionally, we analyse the dynamic behaviour of the onsite and intersite solitons when unstable, where typically it is either in the form of travelling solitons or soliton blow-ups.

  13. Bright light treatment of depression for older adults [ISRCTN55452501

    Directory of Open Access Journals (Sweden)

    Knickerbocker Nancy C

    2005-11-01

    Full Text Available Abstract Background The incidence of insomnia and depression in the elder population is significant. It is hoped that use of light treatment for this group could provide safe, economic, and effective rapid recovery. Methods In this home-based trial we treated depressed elderly subjects with bright white (8,500 Lux and dim red ( Results Eighty-one volunteers, between 60 and 79 years old, completed the study. Both treatment and placebo groups experienced mood improvement. Average GDS scores improved 5 points, the Hamilton Depression Rating Scale (HDRS 17 scores (extracted from the self-rated SIGH-SAD-SR improved 6 points. There were no significant treatment effects or time-by-treatment interactions. No significant adverse reactions were observed in either treatment group. The assays of urine and saliva showed no significant differences between the treatment and placebo groups. The healthy control group was active earlier and slept earlier but received less light than the depressed group at baseline. Conclusion Antidepressant response to bright light treatment in this age group was not statistically superior to placebo. Both treatment and placebo groups experienced a clinically significant overall improvement of 16%.

  14. Suzaku observations of low surface brightness cluster Abell 1631

    Science.gov (United States)

    Babazaki, Yasunori; Mitsuishi, Ikuyuki; Ota, Naomi; Sasaki, Shin; Böhringer, Hans; Chon, Gayoung; Pratt, Gabriel W.; Matsumoto, Hironori

    2018-06-01

    We present analysis results for a nearby galaxy cluster Abell 1631 at z = 0.046 using the X-ray observatory Suzaku. This cluster is categorized as a low X-ray surface brightness cluster. To study the dynamical state of the cluster, we conduct four-pointed Suzaku observations and investigate physical properties of the Mpc-scale hot gas associated with the A 1631 cluster for the first time. Unlike relaxed clusters, the X-ray image shows no strong peak at the center and an irregular morphology. We perform spectral analysis and investigate the radial profiles of the gas temperature, density, and entropy out to approximately 1.5 Mpc in the east, north, west, and south directions by combining with the XMM-Newton data archive. The measured gas density in the central region is relatively low (a few ×10-4 cm-3) at the given temperature (˜2.9 keV) compared with X-ray-selected clusters. The entropy profile and value within the central region (r clusters. These features are also observed in another low surface brightness cluster, Abell 76. The spatial distributions of galaxies and the hot gas appear to be different. The X-ray luminosity is relatively lower than that expected from the velocity dispersion. A post-merger scenario may explain the observed results.

  15. BRITE-Constellation: Nanosatellites for precision photometry of bright stars

    Science.gov (United States)

    Weiss, W. W.; Moffat, A. F. J.; Schwarzenberg-Czerny, A.; Koudelka, O. F.; Grant, C. C.; Zee, R. E.; Kuschnig, R.; Mochnacki, St.; Rucinski, S. M.; Matthews, J. M.; Orleański, P.; Pamyatnykh, A. A.; Pigulski, A.; Alves, J.; Guedel, M.; Handler, G.; Wade, G. A.; Scholtz, A. L.; Scholtz

    2014-02-01

    BRITE-Constellation (where BRITE stands for BRIght Target Explorer) is an international nanosatellite mission to monitor photometrically, in two colours, brightness and temperature variations of stars brighter than V ~ 4, with precision and time coverage not possible from the ground. The current mission design consists of three pairs of 7 kg nanosats (hence ``Constellation'') from Austria, Canada and Poland carrying optical telescopes (3 cm aperture) and CCDs. One instrument in each pair is equipped with a blue filter; the other, a red filter. The first two nanosats (funded by Austria) are UniBRITE, designed and built by UTIAS-SFL (University of Toronto Institute for Aerospace Studies-Space Flight Laboratory) and its twin, BRITE-Austria, built by the Technical University Graz (TUG) with support of UTIAS-SFL. They were launched on 25 February 2013 by the Indian Space Agency, under contract to the Canadian Space Agency. Each BRITE instrument has a wide field of view (~ 24 degrees), so up to 15 bright stars can be observed simultaneously in 32 × 32 sub-rasters. Photometry (with reduced precision but thorough time sampling) of additional fainter targets will be possible through on-board data processing. A critical technical element of the BRITE mission is the three-axis attitude control system to stabilize a nanosat with very low inertia. The pointing stability is better than 1.5 arcminutes rms, a significant advance by UTIAS-SFL over any previous nanosatellite. BRITE-Constellation will primarily measure p- and g-mode pulsations to probe the interiors and ages of stars through asteroseismology. The BRITE sample of many of the brightest stars in the night sky is dominated by the most intrinsically luminous stars: massive stars seen at all evolutionary stages, and evolved medium-mass stars at the very end of their nuclear burning phases (cool giants and AGB stars). The Hertzsprung-Russell diagram for stars brighter than mag V=4 from which the BRITE-Constellation sample

  16. Fostering learners' interaction with content: A learner-centered mobile device interface

    Science.gov (United States)

    Abdous, M.

    2015-12-01

    With the ever-increasing omnipresence of mobile devices in student life, leveraging smart devices to foster students' interaction with course content is critical. Following a learner-centered design iterative approach, we designed a mobile interface that may enable learners to access and interact with online course content efficiently and intuitively. Our design process leveraged recent technologies, such as bootstrap, Google's Material Design, HTML5, and JavaScript to design an intuitive, efficient, and portable mobile interface with a variety of built-in features, including context sensitive bookmarking, searching, progress tracking, captioning, and transcript display. The mobile interface also offers students the ability to ask context-related questions and to complete self-checks as they watch audio/video presentations. Our design process involved ongoing iterative feedback from learners, allowing us to refine and tweak the interface to provide learners with a unified experience across platforms and devices. The innovative combination of technologies built around well-structured and well-designed content seems to provide an effective learning experience to mobile learners. Early feedback indicates a high level of satisfaction with the interface's efficiency, intuitiveness, and robustness from both students and faculty.

  17. LEARNERS SATISFACTION FACTORS IN NEUROLOGY RELATED MOOCs

    Directory of Open Access Journals (Sweden)

    Ionela MANIU

    2017-12-01

    Full Text Available The aim of this article is to investigate the factors that are influencing student satisfaction in case of neurology related massive open online courses (MOOCs. We analyzed data collected from learners enrolled in 40 neurology related MOOCs, by manually looking for information in these courses reviews. The main identified satisfaction factors can be grouped into the following categories: content related factors: course content, additional materials, assignments, external research and teaching - learning related factors (teacher presentation techniques / style: engaging, clear, coherent, knowledgeable, sharing / explanation, interactive, excitement, considering student’s needs, inspiring, sense of humor. Competences, skills and objectives pursued by neurology related MOOCs are also discussed. Analyzing these factors can be useful in new courses management (design and implementation and also in understanding the needs (motivation, behaviors, perception of 21st century learners interested in neurology related fields.

  18. Concept mapping for learners of all ages

    Directory of Open Access Journals (Sweden)

    Nancy L. Gallenstein

    2013-02-01

    Full Text Available Concept mapping is an inquiry technique that provides students at all ages with opportunities to demonstrate learning through performance. A concept map refers to a graphic/visual representation of concepts with linking connections that show various relationships between concepts (Novak & Gowin, 1984. Assessment is an ongoing process integrated with instruction across subject areas. The National Council of Teachers of Mathematics (NCTM emphasizes that assessment should focus on both the enhancement of student learning as well as serve as a valuable tool for making instructional decisions (NCTM, 2000. Assessment activities can take on a variety of forms, one being performance tasks. In this manuscript, an explanation of concept mapping is provided for learners ages 3 – 12 along with several examples of concept maps for young learners, including examples from an assessment project in the subject area of mathematics. Also presented are the numerous benefits of the concept mapping technique for both students and teachers.

  19. WORD-ATTACK SKILLS FOR INDONESIAN LEARNERS

    Directory of Open Access Journals (Sweden)

    Joko Pranowo

    2006-01-01

    Full Text Available The typical drawbacks that affect most Indonesian learners studying English as the target language concern the strategies in dealing with new dictions. The rule of thumb is that the learners are usually tempted to directly look up the meaning in a dictionary when other ways such as guessing the meaning from the context or by dissecting the words into smaller units so that they are able to get a hint from the base word cannot be engineered. As a result of this activity then, they miss crucial points in the realm of word enrichment. This article will shed some light on how to deal with new words and claim that it is not the meaning of a new word that should be the first priority.

  20. Classroom Grammar Teaching for Adult Learners

    Institute of Scientific and Technical Information of China (English)

    石怡

    2014-01-01

    As Wight (1999, p.33) pointed out to“know a language was to know the grammar of it”, hence grammar teaching is usually the main approach in second or foreign language teaching. This paper presents an analysis from three aspects to il-lustrate why classroom grammar teaching benefits adult learners. However, if grammar is overstated, some negative results will occur. Therefore a balance between grammar teaching and communicative skill teaching is need, as is a balance between accuracy and fluency.

  1. Handing over ownership of schools to learners

    CSIR Research Space (South Africa)

    Dlodlo, N

    2012-03-01

    Full Text Available uses the concept of crowd sourcing for social activism and public accountability, serving as a model for what is coined ?activist mapping? ? the combination of social activism, citizenship and geospatial information. It uses social media and mobile... phone coverage in South Africa is fast approaching 100%. Therefore irrespective of where the school is based, the learners are more likely to have access and use the system developed. This is about bridging the digital gap in access to technology...

  2. Micro Coronal Bright Points Observed in the Quiet Magnetic Network by SOHO/EIT

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.

    1997-01-01

    When one looks at SOHO/EIT Fe XII images of quiet regions, one can see the conventional coronal bright points (> 10 arcsec in diameter), but one will also notice many smaller faint enhancements in brightness (Figure 1). Do these micro coronal bright points belong to the same family as the conventional bright points? To investigate this question we compared SOHO/EIT Fe XII images with Kitt Peak magnetograms to determine whether the micro bright points are in the magnetic network and mark magnetic bipoles within the network. To identify the coronal bright points, we applied a picture frame filter to the Fe XII images; this brings out the Fe XII network and bright points (Figure 2) and allows us to study the bright points down to the resolution limit of the SOHO/EIT instrument. This picture frame filter is a square smoothing function (hlargelyalf a network cell wide) with a central square (quarter of a network cell wide) removed so that a bright point's intensity does not effect its own background. This smoothing function is applied to the full disk image. Then we divide the original image by the smoothed image to obtain our filtered image. A bright point is defined as any contiguous set of pixels (including diagonally) which have enhancements of 30% or more above the background; a micro bright point is any bright point 16 pixels or smaller in size. We then analyzed the bright points that were fully within quiet regions (0.6 x 0.6 solar radius) centered on disk center on six different days.

  3. The Relationship between Learner Autonomy and Vocabulary Learning Strategies in Iranian EFL Learners with Different Language Proficiency Level

    Directory of Open Access Journals (Sweden)

    Ebrahim Azimi Mohammad Abadi

    2013-05-01

    Full Text Available Vocabulary learning is incredibly noteworthy to English language acquisition. It is unfeasible for a learner to communicate without the required vocabulary. In high education levels, learners are habitually forced to become autonomous and make conscious effort to learn vocabulary outside of the classroom. Consequently, the autonomy of the learners plays an important role in developing and enhancing their vocabulary. Learner autonomy is a huge assistance for learners in vocabulary learning since it provides the learners with numerous diverse privileges such as independency from teacher. The researcher investigated whether there is any statistically significant relationship between learner autonomy and vocabulary learning strategies use in Iranian EFL learners with different language proficiency levels. To meet the above purpose, a total number of 190 male and female EFL learners participated in this study. The methodology underlying this study was quantitative (thorough the administration of two questionnaires and two language proficiency test – TOEFL for advanced group, and Nelson for intermediate level. The quantitative data was analyzed using a set of correlational analysis revealing a significant positive correlation between learner autonomy and vocabulary learning strategies use in high proficient group, and a significant positive relationship between these two constructs in low proficient group, however not as strong as in the advanced group.

  4. Learner characteristics involved in distance learning

    Energy Technology Data Exchange (ETDEWEB)

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  5. A career exploration programme for learners with special educational needs.

    Science.gov (United States)

    van Niekerk, Matty

    2007-01-01

    Learners with disabilities lag far behind their peers without disabilities in achievement, graduation rates, post-school education and employment outcomes [4]. Against the current state of education affairs in South Africa, where curriculum models for learners with special educational needs (LSEN) are still under revision, therapists and teachers are finding it difficult to prepare these learners for appropriate employment after school. Even where systems in education are established, persons with learning disabilities face more challenges to enter employment [5]. This article reports on a unique career exploration programme for grade 11 learners at a school for learners with special educational needs in Gauteng, South Africa. It is a collaborative strategy between the learners, their parents, a teacher and the occupational therapists at the school. Two case studies are described to indicate the success of the program.

  6. Effect of evening exposure to bright or dim light after daytime bright light on absorption of dietary carbohydrates the following morning.

    Science.gov (United States)

    Hirota, Naoko; Sone, Yoshiaki; Tokura, Hiromi

    2010-01-01

    We had previously reported on the effect of exposure to light on the human digestive system: daytime bright light exposure has a positive effect, whereas, evening bright light exposure has a negative effect on the efficiency of dietary carbohydrate absorption from the evening meal. These results prompted us to examine whether the light intensity to which subjects are exposed in the evening affects the efficiency of dietary carbohydrate absorption the following morning. In this study, subjects were exposed to either 50 lux (dim light conditions) or 2,000 lux (bright light conditions) in the evening for 9 h (from 15:00 to 24:00) after staying under bright light in the daytime (under 2,000 lux from 07:00 to 15:00). We measured unabsorbed dietary carbohydrates using the breath-hydrogen test the morning after exposure to either bright light or dim light the previous evening. Results showed that there was no significant difference between the two conditions in the amount of breath hydrogen. This indicates that evening exposure to bright or dim light after bright light exposure in the daytime has no varying effect on digestion or absorption of dietary carbohydrates in the following morning's breakfast.

  7. Overview English Asa Second Language for Young Learners

    OpenAIRE

    Rini, Setia

    2016-01-01

    Young learners have special charactheristics hence the teachers of English as a Second language needs special strategy too. It is indicated that the increas of abilities to learn second language is started from the early age. We can imagine when the teachers do not use and apply appropriate teaching methods and strategy in teaching English for young learners. As a result, the students’ achievement does not work well. Thus, except to be successful in teaching English for young learners, it is ...

  8. Learner Autonomy in Language Education : A Cross-Cultural Perspective

    OpenAIRE

    Kojima, Hideo

    2006-01-01

    In recent years, the importance of developing learner autonomy in language education hasbeen one of its more prominent themes in Japan as well as in the West. In spite of agreementconcerning its importance, there remains a good deal of uncertainty about its meaning inteaching and learning English as a foreign language (EFL). This paper aims to consider theconcept of learner autonomy amongst different cultures. Autonomy has a social as well as anindividual dimension. The promotion of learner a...

  9. A study on online learner profile for supporting personalized learning

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2013-09-01

    Full Text Available Digital learning as a popular learning approach has received increasing attention in modern education. The learner profile in online learning plays a critical role in supporting personalized learning. This article uses an information flow-based approach to build the learner profile for supporting personalized learning. The learner profile includes the individual profile to capture the personal features and the community profile to capture the social features in online learning environment.

  10. HOW TO MOTIVATE ENGLISH LEARNERS FACED WITH PSYCHOLOGICAL BURDEN

    Directory of Open Access Journals (Sweden)

    Himpun Panggabean

    2007-01-01

    Full Text Available The misleading assumptions of Indonesian-speaking learners of English on the nature of English results in psychological burden inhibiting the process of teaching and learning. The assumptions should be eliminated at the beginning of English class. Besides, the instructor should extensively motivate and encourage the learners to maximize their potentials in learning process. Such approach will gradually lead the learners to self-confidence and self-discovery.

  11. Factors Contributing Decreased Performance Of Slow Learners

    Directory of Open Access Journals (Sweden)

    Dr. L. Kannan

    2015-03-01

    Full Text Available Back ground Even experienced teaching faculty and administrators can be challenged by learners who have not able to perform up to expected need in their annual performance of their students these students are called as slow learnersStruggle learners. There should be a designed study to foster discussion about diagnosing particular problems that contribute with meeting objectives of slow learners. Methodology The study was performed on the entire current first year of Medical students were all the three internal assessments of 250 students performance is taken in to consideration for the study. This study is of cross section type.After obtaining the list of all students marks in internal examination from medical education unit supporting mentors are contacted to meet the students and confidentiality is maintained throughout the study. After obtaining informed consent a questionnaire was administered to the students by the investigator. The questionnaire contains the following sections. Section I will be on the background characteristics of the student name age sex type of family. Section II will be on the details of their learning capabilities. Section III will focus on the awareness of the slow learners in which the precipitating factors contributing to them. Results The prevalence of slow learners as low achievers were contributed to be 32.4 percentages.The performance of the students is based on combination of all three internal assessment marks including theory and practical performance. In this the students age ranges from 17 to 21 years the mean age of student was contributed to be 17.81 and majority of the students were in the age group of 18 years which contributed to be 16867.2.In the present study majority were males 13252.8 compared to females 11847.2.but when study is compared to percentage of attendance majority of the individual 15177 scored more than 50 percentage of marks have more than 80 percentage of attendance but when

  12. Large-area and bright pulsed electroluminescence in monolayer semiconductors

    KAUST Repository

    Lien, Der-Hsien; Amani, Matin; Desai, Sujay B.; Ahn, Geun Ho; Han, Kevin; He, Jr-Hau; Ager, Joel W.; Wu, Ming C.; Javey, Ali

    2018-01-01

    Transition-metal dichalcogenide monolayers have naturally terminated surfaces and can exhibit a near-unity photoluminescence quantum yield in the presence of suitable defect passivation. To date, steady-state monolayer light-emitting devices suffer from Schottky contacts or require complex heterostructures. We demonstrate a transient-mode electroluminescent device based on transition-metal dichalcogenide monolayers (MoS, WS, MoSe, and WSe) to overcome these problems. Electroluminescence from this dopant-free two-terminal device is obtained by applying an AC voltage between the gate and the semiconductor. Notably, the electroluminescence intensity is weakly dependent on the Schottky barrier height or polarity of the contact. We fabricate a monolayer seven-segment display and achieve the first transparent and bright millimeter-scale light-emitting monolayer semiconductor device.

  13. Hacking commercial quantum cryptography systems by tailored bright illumination

    Science.gov (United States)

    Lydersen, Lars; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim

    2010-10-01

    The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built from off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.

  14. Relationships between brightness of nighttime lights and population density

    Science.gov (United States)

    Naizhuo, Z.

    2012-12-01

    Brightness of nighttime lights has been proven to be a good proxy for socioeconomic and demographic statistics. Moreover, the satellite nighttime lights data have been used to spatially disaggregate amounts of gross domestic product (GDP), fossil fuel carbon dioxide emission, and electric power consumption (Ghosh et al., 2010; Oda and Maksyutov, 2011; Zhao et al., 2012). Spatial disaggregations were performed in these previous studies based on assumed linear relationships between digital number (DN) value of pixels in the nighttime light images and socioeconomic data. However, reliability of the linear relationships was never tested due to lack of relative high-spatial-resolution (equal to or finer than 1 km × 1 km) statistical data. With the similar assumption that brightness linearly correlates to population, Bharti et al. (2011) used nighttime light data as a proxy for population density and then developed a model about seasonal fluctuations of measles in West Africa. The Oak Ridge National Laboratory used sub-national census population data and high spatial resolution remotely-sensed-images to produce LandScan population raster datasets. The LandScan population datasets have 1 km × 1 km spatial resolution which is consistent with the spatial resolution of the nighttime light images. Therefore, in this study I selected 2008 LandScan population data as baseline reference data and the contiguous United State as study area. Relationships between DN value of pixels in the 2008 Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) stable light image and population density were established. Results showed that an exponential function can more accurately reflect the relationship between luminosity and population density than a linear function. Additionally, a certain number of saturated pixels with DN value of 63 exist in urban core areas. If directly using the exponential function to estimate the population density for the whole brightly

  15. Design of ultrahigh brightness solar-pumped disk laser.

    Science.gov (United States)

    Liang, Dawei; Almeida, Joana

    2012-09-10

    To significantly improve the solar-pumped laser beam brightness, a multi-Fresnel lens scheme is proposed for side-pumping either a single-crystal Nd:YAG or a core-doped ceramic Sm(3+) Nd:YAG disk. Optimum laser system parameters are found through ZEMAX and LASCAD numerical analysis. An ultrahigh laser beam figure of merit B of 53 W is numerically calculated, corresponding to a significant enhancement of more than 180 times over the previous record. 17.7 W/m(2) collection efficiency is also numerically attained. The strong thermal effects that have hampered present-day rod-type solar-pumped lasers can also be largely alleviated.

  16. PG 1553 + 11 - A bright optically selected BL Lacertae object

    International Nuclear Information System (INIS)

    Falomo, R.; Treves, A.

    1990-01-01

    A detailed study of the bright optically selected BL Lac object PG 1553 + 11 is presented. UV observations, obtained during a high state of the source, together with simultaneous optical spectrophotometry and near-IR photometry, allow the spectral flux distribution to be examined from 8 x 10 to the 13th to 2.5 x 10 to the 15th Hz. This distribution is compared with that derived from quasi-simultaneous observations obtained when the source was a factor of about 3 fainter. It is found that, in the higher state, the spectrum can be described by two power laws connected by a break at about 10 to the 15th Hz, while in the low state the shape is more complex. The overall spectrum of the object is compared with the average energy distribution of X-ray and radio-selected BL Lac objects, showing that it is closer to the former class. 25 refs

  17. Beyond the Kepler/K2 bright limit

    DEFF Research Database (Denmark)

    White, T. R.; Pope, B. J. S.; Antoci, V.

    2017-01-01

    The most powerful tests of stellar models come from the brightest stars in the sky, for which complementary techniques, such as astrometry, asteroseismology, spectroscopy and interferometry, can be combined. The K2 mission is providing a unique opportunity to obtain high-precision photometric time...... have developed a new photometric technique, which we call halo photometry, to observe very bright stars using a limited number of pixels. Halo photometry is simple, fast and does not require extensive pixel allocation, and will allow us to use K2 and other photometric missions, such as TESS, to observe...... to 2000 ppm. For the star Maia, we demonstrate the utility of combining K2 photometry with spectroscopy and interferometry to show that it is not a 'Maia variable', and to establish that its variability is caused by rotational modulation of a large chemical spot on a 10 d time-scale....

  18. ROLE OF DIAMOND SECONDARY EMITTERS IN HIGH BRIGHTNESS ELECTRON SOURCES

    International Nuclear Information System (INIS)

    2005-01-01

    In this paper we explore the possibility of using diamond secondary emitter in a high average current electron injector to amplify the current from the photocathode and to isolate the cathode and the injector from each other to increase the life time of the cathode and preserve the performance of the injector. Secondary electron yield of 225 and current density of 0.8 a/cm 2 have been measured in the transmission mode from type 2 a natural diamond. Although the diamond will be heated during normal operation in the injector, calculations indicate that by cryogenically cooling the diamond, the temperature gradient along the diamond can be maintained within the acceptable range. The electron energy and temporal distributions are expected to be narrow from this device resulting in high brightness beams. Plans are underway to measure the SEY in emission mode, fabricate photocathode-diamond capsule and test diamond and capsule in superconducting RF injector

  19. A new, bright and hard aluminum surface produced by anodization

    Science.gov (United States)

    Hou, Fengyan; Hu, Bo; Tay, See Leng; Wang, Yuxin; Xiong, Chao; Gao, Wei

    2017-07-01

    Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.

  20. High-brightness electron source driven by laser

    International Nuclear Information System (INIS)

    Zhao Kui; Geng Rongli; Wang Lifang

    1996-01-01

    A DC high-brightness laser driven by photo emissive electron gun is being developed at Beijing University, in order to produce 50∼100 ps electron bunches of high quality. The gun consists of a photocathode preparation chamber and a DC acceleration cavity. Different ways of fabricating photocathode, such as chemical vapor deposition, ion beam implantation and ion beam enhanced deposition, can be adopted. The acceleration gap is designed with the aid of simulation codes EGUN and POISSON. 100 kV DC high voltage is fed to the anode through a careful designed ceramic insulator. The laser system is a mode locked Nd-YAG oscillator proceeded by an amplifier at 10 Hz repetition rate, which can deliver three different wavelength (1064/532/266 nm). The combination of a superconducting cavity with the photocathode preparation chamber is discussed

  1. Efficiency of observer brightness discrimination in original and subracted images

    International Nuclear Information System (INIS)

    Swensson, R.G.; Kazda, I.; Nawfel, R.; Judy, P.F.

    1990-01-01

    This paper reports that, for an optimal image calculation, discriminating pairs of objects that differ only in brightness is equivalent to discriminating polarity differences in their subtraction images. This experiment measured and compared how efficiently human observers could perform the two different discriminations posed by such original and subtracted images. Disks of equal size, separated by their diameter, were superimposed on incorrelated, Gaussian noise backgrounds at different contrasts that made the two disks readily visible on the displayed radiographs. The digitally subtracted image-regions containing the two disks of each pair (shifted to registration) produced subtraction images with low-contrast disks that were either brighter or darker than the background. Observer performances in each task (measured by receiver operating characteristic [ROC] analysis) was compared with that of an optimal calculation (cross- correlator)

  2. Criteria for emittance compensation in high-brightness photoinjectors

    Directory of Open Access Journals (Sweden)

    Chun-xi Wang

    2007-10-01

    Full Text Available A critical process in high-brightness photoinjectors is emittance compensation, which brings under control the correlated transverse emittance growth due to the linear space-charge force. Although emittance compensation has been used and studied for almost two decades, the exact criteria to achieve emittance compensation is not as clear as it should be. In this paper, a perturbative analysis of slice envelopes and emittance evolution close to any reference envelope is developed, via which space-charge and chromatic effects are investigated. A new criterion for emittance compensation is found, which is complementary to the well-known matching condition for the invariant envelope and agrees very well with simulations.

  3. High Brightness Injectors Based On Photocathode DC Gun

    International Nuclear Information System (INIS)

    B. Yunn

    2001-01-01

    Sample results of new injector design method based on a photocathode dc gun are presented, based on other work analytically proving the validity of the emittance compensation scheme for the case even when beam bunching is involved. We have designed several new injectors appropriate for different bunch charge ranges accordingly. Excellent beam quality produced by these injectors clearly shows that a photocathode dc gun can compete with a rf gun on an equal footing as the source of an electron beam for the bunch charge ranging up to 2 nano Coulomb (nC). This work therefore elevates a dc gun based injector to the preferred choice for many ongoing high brightness accelerator projects considering the proven operational stability and high average power capability of the dc gun

  4. Beam position monitors for the high brightness lattice

    International Nuclear Information System (INIS)

    Ring, T.

    1985-06-01

    Engineering developments associated with the high brightness lattice and the projected change in machine operating parameters will inherently affect the diagnostics systems and devices installed at present in the storage ring. This is particularly true of the beam position monitoring (BPI) system. The new sixteen unit cell lattice with its higher betatron tune values and the limited space available in the redesigned machine straights for fitting standard BPI vessels forces a fundamental re-evaluation of the beam position monitor system. The design aims for the new system are based on accepting the space limitations imposed while still providing the monitor points required to give good radial and vertical closed orbit plots. The locations of BPI's in the redesigned machine straights is illustrated. A description of the new BPI assemblies and their calibration is given. The BPI's use capacitance button type pick-ups; their response is described. (U.K.)

  5. Multiwavelength Coverage of a Bright Flare from Sgr A

    International Nuclear Information System (INIS)

    Trap, G.; Goldwurm, A.; Terrier, R.

    2009-01-01

    The dynamical center of our galaxy hosts a supermassive black hole, Sgr A*, which has been the target of an extensive multiwavelength campaign for a week in April 2007. We report here the detection of a bright flare from the vicinity of the horizon, observed simultaneously in X-rays (XMM-Newton) and NIR (VLT/NACO) on April 4 th . For the first time, such an event also benefitted from a soft γ-rays (INTEGRAL/ISGRI) and MIR (VLT/VISIR) coverage, which enabled us to derive upper limits at both ends of Sgr A* spectral energy distribution (SED). We discuss the physical implications of the contemporaneous light curves as well as the SED, in terms of synchrotron, synchrotron self-Compton and external Compton emission processes.

  6. Discovery of a bright quasar without a massive host galaxy.

    Science.gov (United States)

    Magain, Pierre; Letawe, Géraldine; Courbin, Frédéric; Jablonka, Pascale; Jahnke, Knud; Meylan, Georges; Wisotzki, Lutz

    2005-09-15

    A quasar is thought to be powered by the infall of matter onto a supermassive black hole at the centre of a massive galaxy. Because the optical luminosity of quasars exceeds that of their host galaxy, disentangling the two components can be difficult. This led in the 1990s to the controversial claim of the discovery of 'naked' quasars. Since then, the connection between quasars and galaxies has been well established. Here we report the discovery of a quasar lying at the edge of a gas cloud, whose size is comparable to that of a small galaxy, but whose spectrum shows no evidence for stars. The gas in the cloud is excited by the quasar itself. If a host galaxy is present, it is at least six times fainter than would normally be expected for such a bright quasar. The quasar is interacting dynamically with a neighbouring galaxy, whose gas might be feeding the black hole.

  7. Investigation of fundamental limits to beam brightness available from photoinjectors

    International Nuclear Information System (INIS)

    Bazarov, Ivan

    2015-01-01

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.

  8. Large-area and bright pulsed electroluminescence in monolayer semiconductors

    KAUST Repository

    Lien, Der-Hsien

    2018-04-04

    Transition-metal dichalcogenide monolayers have naturally terminated surfaces and can exhibit a near-unity photoluminescence quantum yield in the presence of suitable defect passivation. To date, steady-state monolayer light-emitting devices suffer from Schottky contacts or require complex heterostructures. We demonstrate a transient-mode electroluminescent device based on transition-metal dichalcogenide monolayers (MoS, WS, MoSe, and WSe) to overcome these problems. Electroluminescence from this dopant-free two-terminal device is obtained by applying an AC voltage between the gate and the semiconductor. Notably, the electroluminescence intensity is weakly dependent on the Schottky barrier height or polarity of the contact. We fabricate a monolayer seven-segment display and achieve the first transparent and bright millimeter-scale light-emitting monolayer semiconductor device.

  9. Investigation of fundamental limits to beam brightness available from photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Bazarov, Ivan [Cornell Univ., Ithaca, NY (United States)

    2015-07-09

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.

  10. Three Millisecond Pulsars in Fermi LAT Unassociated Bright Sources

    Science.gov (United States)

    Ransom, S. M.; Ray, P. S.; Camilo, F.; Roberts, M. S. E.; Celik, O.; Wolff, M. T.; Cheung, C. C.; Kerr, M.; Pennucci, T.; DeCesar, M. E.; hide

    2010-01-01

    We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsar (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (pulsars are power law in nature with exponential cutoffs at a few Ge V, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of approx 10(exp 30) - 10(exp 31) erg/s are typical of the rare radio MSPs seen in X-rays.

  11. IRAS bright galaxy sample. II. The sample and luminosity function

    International Nuclear Information System (INIS)

    Soifer, B.T.; Sanders, D.B.; Neugebauer, G.; Madore, B.F.; Danielson, G.E.; David Dunlap Observatory, Richmond Hill, Canada; Palomar Observatory; California Institute of Technology, Pasadena)

    1987-01-01

    A statistically complete sample of 324 of the brightest infrared galaxies discovered at 60 microns in the IRAS all-sky survey is described. The results show that far-infrared emission is a significant luminosity component in the local universe, representing 25 percent of the luminosity emitted by stars in the same volume. Above 10 to the 11th solar luminosities, the infrared luminous galaxies are the dominant population of objects in the universe, being as numerous as the Seyfert galaxies and more numerous than quasars at higher luminosities. The infrared luminosity appears to be independent of the optical luminosity of galaxies. Most infrared bright galaxies appear to require much of the interstellar matter to be contributing to the observed infrared luminosity. Approximately 60-80 percent of the far-infrared luminosity of the local universe can be attributed, directly or indirectly, to recent or ongoing star formation. 67 references

  12. Kokugo Dictionaries as Tools for Learners: Problems and Potential

    Directory of Open Access Journals (Sweden)

    Tom GALLY

    2012-10-01

    Full Text Available For second-language learners, monolingual dictionaries can be useful tools because they often provide more detailed explanations of meanings and more extensive vocabulary coverage than bilingual dictionaries do. While learners of English have access to many monolingual dictionaries designed specifically to meet their needs, learners of Japanese must make do with Kokugo dictionaries, that is, monolingual dictionaries intended for native Japanese speakers. This paper, after briefly describing Kokugo dictionaries in general, analyzes a typical entry from such a dictionary to illustrate the advantages and challenges of the use of Kokugo dictionaries by learners of Japanese.

  13. Language Learner Strategies for Building EFL Learners’ Autonomy

    Directory of Open Access Journals (Sweden)

    Hooshang Khoshsima

    2015-11-01

    Full Text Available The critical discussions and matters in enhancing students’ learning performance, knowledge, and language proficiency have received a remarkable degree of attention in educational contexts. This study was undertaken to encourage learners to build the required competence in the foreign language by utilizing learning strategies so that they could become autonomous learners. Language learners' learning difficulties while learning a foreign language were identified in this study. With regard to problems which language learners faced in learning a foreign language, the teachers are able to recognize and to utilize appropriate language learning strategies in order to develop autonomy in learners who conceptualize and use those strategies in the foreign language. The research design adopted for the present study was survey method. The data for the study were collected with the use of a questionnaire. This questionnaire was administered to a total of 60 EFL learners who were selected from a university in Iran. It was used to assess learners’ awareness and perceived use of strategies and to provide data on their best utilized strategies. Results have been driven through statistical analysis. The analyzed data reveal the students’ styles and assist teachers to take part in shifting the strategies and heighten language learners' autonomy. The findings support the claim that knowing and making language learners aware of the most appropriate strategy would assist learners to improve their autonomy and to enhance their learning.

  14. 'n Evaluasie van Pharos Aanleerderwoordeboek vir skole/ Learner's ...

    African Journals Online (AJOL)

    'n Evaluasie van Pharos Aanleerderwoordeboek vir skole/ Learner's Dictionary for Schools en Longman-HAT Afrikaans Dictionary and Grammar for English Speakers in 'n Afrikaanse taalverwerwingskursus op universiteitsvlak.

  15. Issues of promoting learner autonomy in EFL context

    Directory of Open Access Journals (Sweden)

    Pichugova Inna L.

    2016-01-01

    Full Text Available The paper is focuded on investigating the phenomenon of learner autonomy, which has mostly been explored in Europe and the USA and is now attracting attention of researchers and academics in many other countries including Russia. Learner autonomy through a focus on learner reflection and taking responsibility for one’s own learning processes has become a central concern in the recent history of language teaching. However, many language teachers, who are committed to concepts of learnercentredness and autonomy, struggle with the ways to foster learner autonomy or at least to encourage the idea of learner autonomy in language classroom. The study aims at investigating what the most important issues which have a great impact on developing learner autonomy are. Having given special attention to conditions which can insure development of learner autonomy, a model covering seven issues relating to the subject matter has been designed. The authors state that such aspects as choice, goals and needs, support, emotional climate, learning strategies, learner attitude and motivation, and self-esteem should be considered as the goal to promote learner autonomy in EFL context.

  16. Multiwavelength Study of Gamma-Ray Bright Blazars

    Science.gov (United States)

    Morozova, Daria; Larionov, V. M.; Hagen-Thorn, V. A.; Jorstad, S. G.; Marscher, A. P.; Troitskii, I. S.

    2011-01-01

    We investigate total intensity radio images of 6 gamma-ray bright blazars (BL Lac, 3C 279, 3C 273, W Com, PKS 1510-089, and 3C 66A) and their optical and gamma-ray light curves to study connections between gamma-ray and optical brightness variations and changes in the parsec-scale radio structure. We use high-resolution maps obtained by the BU group at 43 GHz with the VLBA, optical light curves constructed by the St.Petersburg State U. (Russia) team using measurements with the 0.4 m telescope of St.Petersburg State U. (LX200) and the 0.7 m telescope of the Crimean Astrophysical Observatory (AZT-8), and gamma-ray light curves, which we have constructed with data provided by the Fermi Large Area Telescope. Over the period from August 2008 to November 2009, superluminal motion is found in all 6 objects with apparent speed ranging from 2c to 40c. The blazars with faster apparent speeds, 3C 273, 3C 279, PKS 1510-089, and 3C 66A, exhibit stronger variability of the gamma-ray emission. There is a tendency for sources with sharply peaked gamma-ray flares to have faster jet speed than sources with gamma-ray light curves with no sharp peaks. Gamma-ray light curves with sharply peaked gamma-ray flares possess a stronger gamma-ray/optical correlations. The research at St.Petersburg State U. was funded by the Minister of Education and Science of the Russian Federation (state contract N#P123). The research at BU was funded in part by NASA Fermi Guest Investigator grant NNX08AV65G and by NSF grant AST-0907893. The VLBA is an instrument of the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  17. Suzaku observations of low surface brightness cluster Abell 1631

    Science.gov (United States)

    Babazaki, Yasunori; Mitsuishi, Ikuyuki; Ota, Naomi; Sasaki, Shin; Böhringer, Hans; Chon, Gayoung; Pratt, Gabriel W.; Matsumoto, Hironori

    2018-04-01

    We present analysis results for a nearby galaxy cluster Abell 1631 at z = 0.046 using the X-ray observatory Suzaku. This cluster is categorized as a low X-ray surface brightness cluster. To study the dynamical state of the cluster, we conduct four-pointed Suzaku observations and investigate physical properties of the Mpc-scale hot gas associated with the A 1631 cluster for the first time. Unlike relaxed clusters, the X-ray image shows no strong peak at the center and an irregular morphology. We perform spectral analysis and investigate the radial profiles of the gas temperature, density, and entropy out to approximately 1.5 Mpc in the east, north, west, and south directions by combining with the XMM-Newton data archive. The measured gas density in the central region is relatively low (a few ×10-4 cm-3) at the given temperature (˜2.9 keV) compared with X-ray-selected clusters. The entropy profile and value within the central region (r < 0.1 r200) are found to be flatter and higher (≳400 keV cm2). The observed bolometric luminosity is approximately three times lower than that expected from the luminosity-temperature relation in previous studies of relaxed clusters. These features are also observed in another low surface brightness cluster, Abell 76. The spatial distributions of galaxies and the hot gas appear to be different. The X-ray luminosity is relatively lower than that expected from the velocity dispersion. A post-merger scenario may explain the observed results.

  18. Human responses to bright light of different durations.

    Science.gov (United States)

    Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

    2012-07-01

    Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

  19. State-Of High Brightness RF Photo-Injector Design

    Science.gov (United States)

    Ferrario, Massimo; Clendenin, Jym; Palmer, Dennis; Rosenzweig, James; Serafini, Luca

    2000-04-01

    The art of designing optimized high brightness electron RF Photo-Injectors has moved in the last decade from a cut and try procedure, guided by experimental experience and time consuming particle tracking simulations, up to a fast parameter space scanning, guided by recent analytical results and a fast running semi-analytical code, so to reach the optimum operating point which corresponds to maximum beam brightness. Scaling laws and the theory of invariant envelope provide to the designers excellent tools for a first parameters choice and the code HOMDYN, based on a multi-slice envelope description of the beam dynamics, is tailored to describe the space charge dominated dynamics of laminar beams in presence of time dependent space charge forces, giving rise to a very fast modeling capability for photo-injectors design. We report in this talk the results of a recent beam dynamics study, motivated by the need to redesign the LCLS photoinjector. During this work a new effective working point for a split RF photoinjector has been discovered by means of the previous mentioned approach. By a proper choice of rf gun and solenoid parameters, the emittance evolution shows a double minimum behavior in the drifting region. If the booster is located where the relative emittance maximum and the envelope waist occur, the second emittance minimum can be shifted at the booster exit and frozen at a very low level (0.3 mm-mrad for a 1 nC flat top bunch), to the extent that the invariant envelope matching conditions are satisfied.

  20. Advanced prior modeling for 3D bright field electron tomography

    Science.gov (United States)

    Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.

    2015-03-01

    Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.

  1. Characterizing bars in low surface brightness disc galaxies

    Science.gov (United States)

    Peters, Wesley; Kuzio de Naray, Rachel

    2018-05-01

    In this paper, we use B-band, I-band, and 3.6 μm azimuthal light profiles of four low surface brightness galaxies (LSBs; UGC 628, F568-1, F568-3, F563-V2) to characterize three bar parameters: length, strength, and corotation radius. We employ three techniques to measure the radius of the bars, including a new method using the azimuthal light profiles. We find comparable bar radii between the I-band and 3.6 μm for all four galaxies when using our azimuthal light profile method, and that our bar lengths are comparable to those in high surface brightness galaxies (HSBs). In addition, we find the bar strengths for our galaxies to be smaller than those for HSBs. Finally, we use Fourier transforms of the B-band, I-band, and 3.6 μm images to characterize the bars as either `fast' or `slow' by measuring the corotation radius via phase profiles. When using the B- and I-band phase crossings, we find three of our galaxies have faster than expected relative bar pattern speeds for galaxies expected to be embedded in centrally dense cold dark matter haloes. When using the B-band and 3.6 μm phase crossings, we find more ambiguous results, although the relative bar pattern speeds are still faster than expected. Since we find a very slow bar in F563-V2, we are confident that we are able to differentiate between fast and slow bars. Finally, we find no relation between bar strength and relative bar pattern speed when comparing our LSBs to HSBs.

  2. Differential Rotation via Tracking of Coronal Bright Points.

    Science.gov (United States)

    McAteer, James; Boucheron, Laura E.; Osorno, Marcy

    2016-05-01

    The accurate computation of solar differential rotation is important both as a constraint for, and evidence towards, support of models of the solar dynamo. As such, the use of Xray and Extreme Ultraviolet bright points to elucidate differential rotation has been studied in recent years. In this work, we propose the automated detection and tracking of coronal bright points (CBPs) in a large set of SDO data for re-evaluation of solar differential rotation and comparison to other results. The big data aspects, and high cadence, of SDO data mitigate a few issues common to detection and tracking of objects in image sequences and allow us to focus on the use of CBPs to determine differential rotation. The high cadence of the data allows to disambiguate individual CBPs between subsequent images by allowing for significant spatial overlap, i.e., by the fact that the CBPs will rotate a short distance relative to their size. The significant spatial overlap minimizes the effects of incorrectly detected CBPs by reducing the occurrence of outlier values of differential rotation. The big data aspects of the data allows to be more conservative in our detection of CBPs (i.e., to err on the side of missing CBPs rather than detecting extraneous CBPs) while still maintaining statistically larger populations over which to study characteristics. The ability to compute solar differential rotation through the automated detection and tracking of a large population of CBPs will allow for further analyses such as the N-S asymmetry of differential rotation, variation of differential rotation over the solar cycle, and a detailed study of the magnetic flux underlying the CBPs.

  3. SURFACE BRIGHTNESS PROFILES OF DWARF GALAXIES. I. PROFILES AND STATISTICS

    International Nuclear Information System (INIS)

    Herrmann, Kimberly A.; Hunter, Deidre A.; Elmegreen, Bruce G.

    2013-01-01

    Radial surface brightness profiles of spiral galaxies are classified into three types: (I) single exponential, or the light falls off with one exponential to a break before falling off (II) more steeply, or (III) less steeply. Profile breaks are also found in dwarf disks, but some dwarf Type IIs are flat or increasing out to a break before falling off. Here we re-examine the stellar disk profiles of 141 dwarfs: 96 dwarf irregulars (dIms), 26 Blue Compact Dwarfs (BCDs), and 19 Magellanic-type spirals (Sms). We fit single, double, or even triple exponential profiles in up to 11 passbands: GALEX FUV and NUV, ground-based UBVJHK and Hα, and Spitzer 3.6 and 4.5 μm. We find that more luminous galaxies have brighter centers, larger inner and outer scale lengths, and breaks at larger radii; dwarf trends with M B extend to spirals. However, the V-band break surface brightness is independent of break type, M B , and Hubble type. Dwarf Type II and III profiles fall off similarly beyond the breaks but have different interiors and IIs break ∼twice as far as IIIs. Outer Type II and III scale lengths may have weak trends with wavelength, but pure Type II inner scale lengths clearly decrease from the FUV to visible bands whereas Type III inner scale lengths increase with redder bands. This suggests the influence of different star formation histories on profile type, but nonetheless the break location is approximately the same in all passbands. Dwarfs continue trends between profile and Hubble types such that later-type galaxies have more Type II but fewer Type I and III profiles than early-type spirals. BCDs and Sms are over-represented as Types III and II, respectively, compared to dIms

  4. How Do Chinese ESL Learners Recognize English Words during a Reading Test? A Comparison with Romance-Language-Speaking ESL Learners

    Science.gov (United States)

    Li, Hongli; Suen, Hoi K.

    2015-01-01

    This study examines how Chinese ESL learners recognize English words while responding to a multiple-choice reading test as compared to Romance-language-speaking ESL learners. Four adult Chinese ESL learners and three adult Romance-language-speaking ESL learners participated in a think-aloud study with the Michigan English Language Assessment…

  5. Bright solitons in coupled defocusing NLS equation supported by coupling: Application to Bose-Einstein condensation

    International Nuclear Information System (INIS)

    Adhikari, Sadhan K.

    2005-01-01

    We demonstrate the formation of bright solitons in coupled self-defocusing nonlinear Schroedinger (NLS) equation supported by attractive coupling. As an application we use a time-dependent dynamical mean-field model to study the formation of stable bright solitons in two-component repulsive Bose-Einstein condensates (BECs) supported by interspecies attraction in a quasi one-dimensional geometry. When all interactions are repulsive, there cannot be bright solitons. However, bright solitons can be formed in two-component repulsive BECs for a sufficiently attractive interspecies interaction, which induces an attractive effective interaction among bosons of same type

  6. Dark and bright solitons in a quasi-one-dimensional Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Wang, Shun-Jin; Jia, Cheng-Long; An, Jun-Hong; Zhao, Dun; Luo, Hong-Gang

    2003-01-01

    The analytical dark and bright soliton solutions of the one-dimensional Gross-Pitaevskii equation with a confining potential are obtained. For the bright soliton, the recent experimental finding is studied, and the particle number of the soliton and the window of the particle numbers for the bright soliton to occur are estimated analytically and in good agreement with the experimental data. The existence of dark soliton for the attractive interaction and bright soliton for the repulsive interaction is predicted under proper conditions

  7. Bright galaxies in the Fornax cluster. Automated galaxy surface photometry: Pt. 7

    International Nuclear Information System (INIS)

    Disney, M.J.; Phillipps, S.; Davies, J.L.; Cawson, M.G.M.; Kibblewhite, E.J.

    1990-01-01

    We have determined surface-brightness profiles for all galaxies down to magnitude B = 16 in the central region of the Fornax cluster. Using existing redshift data, we have determined the distributions of surface brightness for both the whole sample and for cluster disc galaxies only. Although both distributions peak at extrapolated central surface brightness ∼ 21.7B mag/arcsec 2 (the canonical result), it is shown that they are, in fact, consistent with very broad distributions of disc central surface brightness once selection effects and the effects of bulge contamination of the profile are taken into account. (author)

  8. Observation of near-infrared surface brightness of the large Magellanic cloud

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Koizumi, Yutaka; Matsumoto, Toshio; Murakami, Hiroshi; Uyama, Kiichiro.

    1981-01-01

    The near-infrared surface brightness of the large Magellanic cloud was observed by an infrared telescope carried by a balloon. The balloon flight was made at Australian Balloon Launching Station. The brightness distribution of 2.4 Mu m radiation was obtained. A part of Bar was bright, and the expansion of the contour at the east end of Bar corresponded to the 30 Dor region. Many near-infrared sources distribute in this region. Discussions on the color and brightness of the center of Bar and the 30 Dor region are presented. (Kato, T.)

  9. Motivational Orientations and Second Learner Variables of East Asian Language Learners in the United States.

    Science.gov (United States)

    Yang, Jean Sook Ryu

    2003-01-01

    College Students enrolled in East Asian language classes were surveyed about their language learning motivational orientations (MOs). MOs were classified and measured on seven subscales; integrative, instrumental, heritage-related, travel, interest, school-related, and language use. Learners were highly influenced by interest, language use, and…

  10. The Correlation between Learner Autonomy and English Proficiency of Indonesian EFL College Learners

    Science.gov (United States)

    Myartawan, I. Putu Ngurah Wage; Latief, Mohammad Adnan; Suharmanto

    2013-01-01

    The present study aimed to investigate the correlation between learner autonomy psychologically defined in the study as a composite of behavioral intentions to do autonomous learning and self-efficacy in relation to autonomous learning, and English proficiency. The sample comprised 120 first semester English-majored students of a state university…

  11. Washback to the Learner: Learner and Teacher Perspectives on IELTS Preparation Course Expectations and Outcomes

    Science.gov (United States)

    Green, Anthony

    2006-01-01

    The washback effect of tests on teaching has attracted considerable attention over recent years, but the critical question of how this translates into washback on learning remains under-explored. To address this issue, questionnaires relating to academic writing instruction were distributed to 108 learners from mainland China preparing for…

  12. The Influence of Teacher Power on English Language Learners' Self-Perceptions of Learner Empowerment

    Science.gov (United States)

    Diaz, Abel; Cochran, Kathryn; Karlin, Nancy

    2016-01-01

    English language learners (ELL) are students with a primary language spoken other than English enrolled in U.S. educational settings. As ELL students take on the challenges of learning English and U.S. culture, they must also learn academic content. The expectation to succeed academically in a foreign culture and language, while learning to speak…

  13. Teaching language arts to English language learners

    CERN Document Server

    Vásquez, Anete; Smith, Philip C

    2013-01-01

    This thoroughly revised and updated edition of Teaching Language Arts to English Language Learners provides readers with the comprehensive understanding of both the challenges that face ELLs and ways in which educators might address them in the language arts classroom. The authors offer proven techniques that teachers can readily use to teach reading, writing, grammar, and vocabulary as well as speaking, listening, and viewing skills. A complete section is also devoted to ways teachers can integrate all five strands of the language arts curriculum into a comprehensive unit of study w

  14. Controlling excitons. Concepts for phosphorescent organic LEDs at high brightness

    Energy Technology Data Exchange (ETDEWEB)

    Reineke, Sebastian

    2009-11-15

    This work focusses on the high brightness performance of phosphorescent organic light-emitting diodes (OLEDs). The use of phosphorescent emitter molecules in OLEDs is essential to realize internal electron-photon conversion efficiencies of 100 %. However, due to their molecular nature, the excited triplet states have orders of magnitude longer time constants compared to their fluorescent counterparts which, in turn, strongly increases the probability of bimolecular annihilation. As a consequence, the efficiencies of phosphorescent OLEDs decline at high brightness - an effect known as efficiency roll-off, for which it has been shown to be dominated by triplet-triplet annihilation (TTA). In this work, TTA of the archetype phosphorescent emitter Ir(ppy){sub 3} is investigated in time-resolved photoluminescence experiments. For the widely used mixed system CBP:Ir(ppy){sub 3}, host-guest TTA - an additional unwanted TTA channel - is experimentally observed at high excitation levels. By using matrix materials with higher triplet energies, this effect is efficiently suppressed, however further studies show that the efficiency roll-off of Ir(ppy)3 is much more pronounced than predicted by a model based on Foerster-type energy transfer, which marks the intrinsic limit for TTA. These results suggest that the emitter molecules show a strong tendency to form aggregates in the mixed film as the origin for enhanced TTA. Transmission electron microscopy images of Ir(ppy){sub 3} doped mixed films give direct proof of emitter aggregates. Based on these results, two concepts are developed that improve the high brightness performance of OLEDs. In a first approach, thin intrinsic matrix interlayers are incorporated in the emission layer leading to a one-dimensional exciton confinement that suppresses exciton migration and, consequently, TTA. The second concept reduces the efficiency roll-off by using an emitter molecule with slightly different chemical structure, i.e. Ir(ppy){sub 2

  15. High Brightness Neutron Source for Radiography. Final report

    International Nuclear Information System (INIS)

    Cremer, J.T.; Piestrup, Melvin A.; Gary, Charles K.; Harris, Jack L.; Williams, David J.; Jones, Glenn E.; Vainionpaa, J.H.; Fuller, Michael J.; Rothbart, George H.; Kwan, J.W.; Ludewigt, B.A.; Gough, R.A.; Reijonen, Jani; Leung, Ka-Ngo

    2008-01-01

    This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases

  16. Emotional Intelligence in Learners with Attention Deficit Disorder

    Science.gov (United States)

    Wootton, Carol Anne; Roets, H. E.

    2013-01-01

    This study was undertaken to analyse and evaluate the nature and quality of emotional intelligence in learners with Attention Deficit Disorder (ADD), and to investigate whether their emotional intelligence was enhanced, and whether the symptoms and behaviour of these learners improved, after exposure to a programme on emotional intelligence.…

  17. Theories in Developing Oral Communication for Specific Learner Group

    Science.gov (United States)

    Hadi, Marham Jupri

    2016-01-01

    The current article presents some key theories most relevant to the development of oral communication skills in an Indonesian senior high school. Critical analysis on the learners' background is employed to figure out their strengths and weaknesses. The brief overview of the learning context and learners' characteristic are used to identify which…

  18. South African law and policy regulating learner absenteeism

    African Journals Online (AJOL)

    Packard Bell

    Department of Psychology of Education, College of Education, University of ... Keywords: ecosystemic theory; learner absenteeism; management approach; South African law and policy ..... learners, but can also be cultural and systemic ..... tesis. Pretoria, Suid-Afrika: Universiteit van Suid-. Afrika. Beskikbaar te .... Phd thesis.

  19. Supporting English Language Learners in Math Class, Grades K-2

    Science.gov (United States)

    Bresser, Rusty; Melanese, Kathy; Sphar, Christine

    2009-01-01

    More than 10 percent of the students in our nation's public schools are English language learners, and this number grows each year. Many of these students are falling behind in math. "Supporting English Language Learners in Math Class, Grades K-2" outlines the challenges ELL students face when learning math and provides a wealth of specific…

  20. Distribution of Articles in Written Composition among Malaysian ESL Learners

    Science.gov (United States)

    Rahim, Mia Emily Abdul; Rahim, Emma Marini Abdul; Ning, Chia Han

    2013-01-01

    The study aimed to investigate the distribution patterns of the English grammar articles (a, an, and the) as well as the distributions of their colligation patterns in written compositions of English among Malaysian ESL learners. This paper reports the results of a corpus-based study on articles used by these learners. The method used in this…

  1. Sensitizing Young English Language Learners Towards Environmental Care

    Science.gov (United States)

    Castillo, Rigoberto; Rojas, María del Pilar

    2014-01-01

    This paper reports an action research study aimed at understanding how to sensitize young English language learners towards caring for the environment. The pedagogical intervention in a 5th grade class consisted in the use of creative writing strategies to express learners' ideas. Three stages were followed: "recognizing facts,"…

  2. Action towards hope: Addressing learner behaviour in a classroom

    Directory of Open Access Journals (Sweden)

    Raelene LeeFon

    2013-11-01

    Full Text Available Unruly learners and disciplinary problems are an intractable part of every teacher’s teaching experience. It appears that, even though most schools have enacted a code of conduct to regulate learner behaviour, this does not always have the desired effect. Disciplinary problems in schools impact negatively on the teaching and learning environment as well as on teachers’ personal and professional well-being and morale. Framed within the context of a biblical worldview, this article narrates the experiences of one teacher who decided to take action towards hope. The situation in her classroom was quite desperate with learners coming to school unprepared and behaving very badly and parents being uninterested in the performance of their children at school. She realised that she could not change the learners or their parents unless she started with herself. In this context, she, as a postgraduate student under the supervision of the co-authors, embarked on an action-research project to promote positive learner behaviour. By collaborating with the learners on a set of classroom rules, engaging in reflective teaching and changing her own behaviour towards the learners, the situation in her classroom improved. Based on her experiences, this article argues that teachers should empower themselves with knowledge and a better understanding of the concept of discipline rather than viewing the classroom as a battlefield. It is important to acknowledge and show respect and appreciation for each learner in his or her own context.

  3. Equity in changing patterns of enrolment, in learner retentionand ...

    African Journals Online (AJOL)

    This article highlights the need to address the kind of knowledge and skills that staff need in order to design and deliver transformed curricula whilst designing and implementing comprehensive integrated learner-centred support strategies to ensure learner success and retention. South African Journal of Higher Education ...

  4. Improving the EFL Learners' Speaking Ability through Interactive Storytelling

    Science.gov (United States)

    Marzuki; Prayogo, Johannes Ananto; Wahyudi, Arwijati

    2016-01-01

    This present research was aimed to improve the EFL learners' speaking ability and their classroom activities through the implementation of Interactive Storytelling Strategy. Therefore, this study was directed to explore the beneficial of Interactive Storytelling that closely related to the EFL learners' everyday activities at their home and…

  5. Online Learner Engagement: Opportunities and Challenges with Using Data Analytics

    Science.gov (United States)

    Bodily, Robert; Graham, Charles R.; Bush, Michael D.

    2017-01-01

    This article describes the crossroads between learning analytics and learner engagement. The authors do this by describing specific challenges of using analytics to support student engagement from three distinct perspectives: pedagogical considerations, technological issues, and interface design concerns. While engaging online learners presents a…

  6. Fostering EFL Learners' Reading Comprehension: Animation Film Technique

    Science.gov (United States)

    Torabian, Asefeh; Tajadini, Massoud

    2017-01-01

    The current study investigated the effect of implementing animation films on developing reading comprehension texts among EFL learners of a language institute in Kerman. For this purpose, two groups of pre-intermediate EFL learners were chosen (30 participants in each group). After three months of instruction, twice a week, 2story books named the…

  7. Digital Learners: How Are They Expanding the Horizon of Learning?

    Science.gov (United States)

    Jackson, Sherion H.; Crawford, Debi

    2008-01-01

    Young learners today are not growing up at the foot of the family radio or spending a good portion of their childhood glued to the television while Sesame Street and Mr. Rogers disseminate information in a constant stream as did previous generations. Rather, this generation of young learners continues to spend many out-of-school hours in a digital…

  8. Predicting the Proficiency Level of Language Learners Using Lexical Indices

    Science.gov (United States)

    Crossley, Scott A.; Salsbury, Tom; McNamara, Danielle S.

    2012-01-01

    This study explores how second language (L2) texts written by learners at various proficiency levels can be classified using computational indices that characterize lexical competence. For this study, 100 writing samples taken from 100 L2 learners were analyzed using lexical indices reported by the computational tool Coh-Metrix. The L2 writing…

  9. Evaluating Bilingual and Monolingual Dictionaries for L2 Learners.

    Science.gov (United States)

    Hunt, Alan

    1997-01-01

    A discussion of dictionaries and their use for second language (L2) learning suggests that lack of computerized modern language corpora can adversely affect bilingual dictionaries, commonly used by L2 learners, and shows how use of such corpora has benefitted two contemporary monolingual L2 learner dictionaries (1995 editions of the Longman…

  10. Motivation and Attitude of Grade Nine Learners Towards ...

    African Journals Online (AJOL)

    Mathematics and Science Study (TIMSS, 2003) conducted a test in ... sharpen their skills and tap into modern learners' natural affinity for all things ... and psychological influence of learners and educators towards positive ... regulation theory postulates that individuals can fortify their own motivation ... The mastering of.

  11. Written Corrective Feedback: The Perception of Korean EFL Learners

    Science.gov (United States)

    Chung, Bohyon

    2015-01-01

    This paper reports on the perception of Korean EFL learners toward feedback types on their written errors. The survey was administered using an adopted questionnaire from previous studies (Ishii 2011; Leki, 1991). This further allows a comparison of Korean EFL learners' attitudes with the responses to an identical questionnaire by Japanese EFL…

  12. Teaching strategies to support isiXhosa learners who receive ...

    African Journals Online (AJOL)

    There are a number of challenges related to teaching in a multi-linguistic classroom. Despite the literature clearly indicating how learners acquire learning, there is still a dearth of material on descriptions of current support provided to learners within the theoretical framework of Bronfenbrenner's ecological systems theory.

  13. Information on Quantifiers and Argument Structure in English Learner's Dictionaries.

    Science.gov (United States)

    Lee, Thomas Hun-tak

    1993-01-01

    Lexicographers have been arguing for the inclusion of abstract and complex grammatical information in dictionaries. This paper examines the extent to which information about quantifiers and the argument structure of verbs is encoded in English learner's dictionaries. The Oxford Advanced Learner's Dictionary (1989), the Longman Dictionary of…

  14. Ambiguity Tolerance and Perceptual Learning Styles of Chinese EFL Learners

    Science.gov (United States)

    Li, Haishan; He, Qingshun

    2016-01-01

    Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…

  15. Facilitating and Dealing with Learner Differences in the Online Classroom

    Science.gov (United States)

    McFarlane, Donovan A.

    2012-01-01

    This paper explores the challenges faced by teachers and educators in the online classroom, especially in light of existing learner differences among students stemming from intelligence, socioeconomic status (SES), culture, gender, among other factors. The author examines the characteristics of the online classroom and looks at learner differences…

  16. Understanding Learner Agency as a Complex Dynamic System

    Science.gov (United States)

    Mercer, Sarah

    2011-01-01

    This paper attempts to contribute to a fuller understanding of the nature of language learner agency by considering it as a complex dynamic system. The purpose of the study was to explore detailed situated data to examine to what extent it is feasible to view learner agency through the lens of complexity theory. Data were generated through a…

  17. Experiences of learners from informal settlements | Pillay | South ...

    African Journals Online (AJOL)

    Analysis of the data revealed that learners experience a variety of negative feelings, that they were misunderstood by their educators and other learners and that they experienced racial discrimination, bullying and ganging-up. On the positive side, however, they felt privileged to be in schools where there was a good quality ...

  18. Equipping Learners with Listening Strategies in English Language Classes

    Science.gov (United States)

    Seferoglu, Golge; Uzakgoren, Sedef

    2004-01-01

    This study aimed at investigating beginner level English language learners' perspectives on the listening skill with regard to several dimensions, and to find out the extent to which the learners who have been trained in listening strategies actually use them while listening. The study took place at the English Preparatory School of an English…

  19. An exploratory survey of male and female learner opinions on ...

    African Journals Online (AJOL)

    An exploratory survey was undertaken to determine whether secondary school learners have certain preferences regarding the biology they study at school and whether learners from co-educational and single-sex schools hold the same opinions. A survey schedule comprising two components was developed. The first ...

  20. Developing an English Mobile Learning Attitude Scale for Adult Learners

    Science.gov (United States)

    Liu, Tzu-Ying

    2017-01-01

    In recent years, with the rapid development of mobile devices, mobile learning (m-learning) has becoming another popular topic. There is a strong need for both researchers and educators to be aware of adult learners' attitudes toward English mobile learning, yet relevant studies on mobile learning to promote English learning for adult learners are…

  1. College English Learners' Discursive Motivation Construction in China

    Science.gov (United States)

    Gu, Mingyue

    2009-01-01

    There are abundant studies of second/foreign language learning motivation. However, there appears to be insufficient research into how language learners' discourses mediate the construction of their learning/motivation. This paper investigated the discursive construction of two English language learners' motivation in a comprehensive university in…

  2. Learners' Motivation for Literacy in the Mother Tongue 1: Ibadan ...

    African Journals Online (AJOL)

    The study examines the desirability of and motivational needs for basic literacy in the mother tongue and library use in lbadan metropolis. Data were collected through indepth interviews with 25 adult basic learners. The study reveals a strong desire for literacy in the mother tongue by the respondents. The learners' ...

  3. Relational Aggression: The Voices of Primary School Learners

    Science.gov (United States)

    Botha, Johan

    2014-01-01

    The aim of this research was to explore and describe primary school learners' experiences of relational aggression at school. This was done within a qualitative research design with a phenomenological approach. In order to give a voice to primary school learners' lived experiences of relational aggression, 25 individual interviews were conducted…

  4. Semantic processing skills of Grade 1 English language learners in ...

    African Journals Online (AJOL)

    This paper reports on part of the first phase of a longitudinal project investigating the development of academic language in English as the Language of Teaching and Learning (LoLT) by Foundation phase learners in two different educational contexts. In the first context, the learners were all English additional language ...

  5. A Blended Learning Scenario to Enhance Learners' Oral Production Skills

    Science.gov (United States)

    Kim, Hee-Kyung

    2015-01-01

    This paper examines the effectiveness of a mobile assisted blended learning scenario for pronunciation in Korean language. In particular, we analyze how asynchronous oral communication between learners of Korean and native speakers via "kakaotalk" (an open source mobile phone application) may be beneficial to the learner in terms of…

  6. A Learner Perspective on Barriers to E-Learning

    Science.gov (United States)

    Becker, Karen; Newton, Cameron; Sawang, Sukanlaya

    2013-01-01

    This study aims to identify and categorize barriers to e-learning adoption and the relative impact of those barriers on learners. It contributes to the understanding of learner perceptions of barriers, the different types of barriers and their relative importance. This study used a quantitative methodology grounded in previous literature. The…

  7. Expanding Roles: Teacher Educators' Perspectives on Educating English Learners

    Science.gov (United States)

    Daniel, Shannon; Peercy, Megan Madigan

    2014-01-01

    Although the underpreparation of teachers to work with English learners is a documented problem in teacher education, little research has addressed teacher educators' perspectives in guiding prospective teachers to educate English learners. This case study of one 13-month elementary certification program highlights teacher educators' efforts and…

  8. Benchmarking the Degree of Implementation of Learner-Centered Approaches

    Science.gov (United States)

    Blumberg, Phyllis; Pontiggia, Laura

    2011-01-01

    We describe an objective way to measure whether curricula, educational programs, and institutions are learner-centered. This technique for benchmarking learner-centeredness uses rubrics to measure courses on 29 components within Weimer's five dimensions. We converted the scores on the rubrics to four-point indices and constructed histograms that…

  9. Emergent Target Language Identities among Latino English Language Learners

    Science.gov (United States)

    Ciriza-Lope, Maria; Shappeck, Marco; Arxer, Steven

    2016-01-01

    During 2nd language acquisition, a learner's identity is consigned, juxtaposed, coconstructed, and reified through various affective positions and mitigating linguistic behaviors. Our study of adult Latino ESL students in Dallas, Texas, shows how language socialization experiences are shaped by the learners' affective stances toward the project of…

  10. A Descriptive Study on EFL Learners' Perceptions of Facebook

    Science.gov (United States)

    Aydin, Selami

    2017-01-01

    There is a strong need to investigate English as a foreign language (EFL) learners' perceptions of Facebook as a language-learning environment, as their perceptions that directly influence their language development and achievement have not been examined within the EFL learning context. Thus, this study aims to investigate EFL learners'…

  11. Learner Managed Learning: Managing To Learn or Learning To Manage?

    Science.gov (United States)

    Harrison, Roger

    2000-01-01

    In the discourse of learner self-management, learners must take responsibility for learning and are offered the possibility of individual autonomy and control. A critical perspective reveals that environmental constraints inhibit the success of technical-rational self-management techniques. An alternative view is the entrepreneurial self, a…

  12. Learner Behaviors and Perceptions of Autonomous Language Learning

    Science.gov (United States)

    Bekleyen, Nilüfer; Selimoglu, Figen

    2016-01-01

    The purpose of the present study was to investigate the learners' behaviors and perceptions about autonomous language learning at the university level in Turkey. It attempts to reveal what type of perceptions learners held regarding teachers' and their own responsibilities in the language learning process. Their autonomous language learning…

  13. They're Not Just Big Kids: Motivating Adult Learners.

    Science.gov (United States)

    Thoms, Karen Jarrett

    This paper discusses motivation of adult learners. The first section discusses the adult learner, including the concepts of andragogy and pedagogy, as well as student-centered learning. The second section summarizes changing student demographics and predictions. The third section presents principles of adult learning. The fourth section covers…

  14. Speaking Self-Assessment: Mismatches between Learners' and Teachers' Criteria

    Science.gov (United States)

    Babaii, Esmat; Taghaddomi, Shahin; Pashmforoosh, Roya

    2016-01-01

    Perceptual (mis)matches between teachers and learners are said to affect learning success or failure. Self-assessment, as a formative assessment tool, may, inter alia, be considered a means to minimize such mismatches. Therefore, the present study investigated the extent to which learners' assessment of their own speaking performance, before and…

  15. Treating the Non-Learner: Penicillin or Placebo?

    Science.gov (United States)

    McDonald, Carl B.; Cotroneo, Keith

    Non-learners are externally controlled students conditioned to expect both failure and success. They are aware of their basic skill deficiencies yet know that passive behavior in high school classrooms has resulted in passing grades. Given the nature of the non-learner, developmental educators cannot achieve positive results through manipulating…

  16. Black Grade 9 learners in historically white suburban schools and ...

    African Journals Online (AJOL)

    Any school that denies that intercultural and interracial differences exist and that lacks effective accommodation strategies for all its learners could thwart learners' feelings of truly belonging to the school. This could leave them feeling like outsiders an experience that could have a negative impact on their school careers and ...

  17. Predictors of reading literacy for first and second language learners

    NARCIS (Netherlands)

    Netten, A.R.; Droop, W.; Verhoeven, L.T.W.

    2011-01-01

    In this study an attempt was made to construct a multi-factor model predicting the development of reading literacy in the upper grades of primary school in the Netherlands for subgroups of 729 first language (L1) learners and 93 second language (L2) learners. Following a longitudinal design, it was

  18. Communicating Grammatically: Evaluating a Learner Strategy Website for Spanish Grammar

    Science.gov (United States)

    Cohen, Andrew D.; Pinilla-Herrera, Angela; Thompson, Jonathan R.; Witzig, Lance E.

    2011-01-01

    After a brief introduction to language learner strategies and grammar strategies as a subcategory, it is pointed out that research on the use of grammar strategies by learners of a second language (L2) has been limited. The article then describes the construction of a website with strategies for learning and performing Spanish grammar, with a…

  19. Language Learning Strategies of Language e-Learners in Turkey

    Science.gov (United States)

    Solak, Ekrem; Cakir, Recep

    2015-01-01

    The purpose of this study was to determine the use of language learning strategies of e-learners and to understand whether there were any correlations between language learning strategies and academic achievement. Participants of the study were 274?e-learners, 132 males and 142 females, enrolled in an e-learning program from various majors and…

  20. Adapting Progress Feedback and Emotional Support to Learner Personality

    Science.gov (United States)

    Dennis, Matt; Masthoff, Judith; Mellish, Chris

    2016-01-01

    As feedback is an important part of learning and motivation, we investigate how to adapt the feedback of a conversational agent to learner personality (as well as to learner performance, as we expect an interaction effect between personality and performance on feedback). We investigate two aspects of feedback. Firstly, we investigate whether the…