WorldWideScience

Sample records for brisbane city hall

  1. Sustainable urban development in Brisbane City--the Holy Grail?

    Science.gov (United States)

    Rahman, K; Weber, T

    2003-01-01

    Impacts from urban stormwater runoff on receiving environments have been well documented, particularly through specific regional scientific studies. Using various local government planning and management elements, urban developments in Brisbane City are now able to address stormwater management in an increasingly holistic context. One key initiative includes facilitating Water Sensitive Urban Design (WSUD) components within an Integrated Water Management Strategy that looks at policy formation, planning strategies, design option, community marketing and acceptance, maintenance programs and finally evaluation of various WSUD approaches. These can include the use of Natural Channel Designs, grassed swales, bio-filtration systems, porous pavements and roofwater tanks in several economic combinations. By linking with the Cooperative Research Centre for Catchment Hydrology, Brisbane City Council has influenced the design of WSUD planning tools and benefited the city with academic inputs into extensive evaluation programs. As well, it has also contributed to the Cooperative Research Centre's research outcomes. These evaluation programs are increasingly providing better understanding of various stormwater quality best management practices throughout Australia. As part of the overall implementation process, active involvement by a range of stakeholders has been crucial. These stakeholders have included internal planning, development assessment and design staff, external consultants, developers, and other local and state government agencies. The latter two groups are assisting in the important task of "regionalisation" of Brisbane City Council's policies and guidelines. Implementation of WSUD initiatives and stormwater re-use strategies under Council's new "Integrated Water Management" agenda are showing some excellent results, suggesting that sustainable urban development is no longer like the search for the Holy Grail.

  2. City and Town Halls; townHalls13

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — Locations of city and town halls in Rhode Island. Derived using information originally compiled by the State of Rhode Island (http://www.ri.gov), and built upon...

  3. Did Brisbane Grow Smartly? Drivers of City Growth 1991-2001 and Lessons for Current Policies

    Directory of Open Access Journals (Sweden)

    Farjana Mostafiz Shatu

    2014-10-01

    Full Text Available Urban areas are growing unsustainably around the world; however, the growth patterns and their associated drivers vary between contexts. As a result, research has highlighted the need to adopt case study based approaches to stimulate the development of new theoretic understandings. Using land-cover data sets derived from Landsat images (30 m × 30 m, this research identifies both patterns and drivers of urban growth in a period (1991-2001 when a number of policy acts were enacted aimed at fostering smart growth in Brisbane, Australia. A linear multiple regression model was estimated using the proportion of lands that were converted from non-built-up (1991 to built-up usage (2001 within a suburb as a dependent variable to identify significant drivers of land-cover changes. In addition, the hot spot analysis was conducted to identify spatial biases of land-cover changes, if any. Results show that the built-up areas increased by 1.34% every year. About 19.56% of the non-built-up lands in 1991 were converted into built-up lands in 2001. This conversion pattern was significantly biased in the northernmost and southernmost suburbs in the city. This is due to the fact that, as evident from the regression analysis, these suburbs experienced a higher rate of population growth, and had the availability of habitable green field sites in relatively flat lands. The above findings suggest that the policy interventions undertaken between the periods were not as effective in promoting sustainable changes in the environment as they were aimed for.

  4. The Role Innovative Housing Models Play in the Struggle against Social Exclusion in Cities: The Brisbane Common Ground Model

    Directory of Open Access Journals (Sweden)

    Petra Perolini

    2015-04-01

    Full Text Available The history of housing in Australia is a textbook example of socio-spatial exclusion as described, defined and analysed by commentators from Mumford to Lefebvre. It has been exacerbated by a culture of home ownership that has led to an affordability crisis. An examination of the history reveals that the problems are structural and must be approached not as a practical solution to the public provision of housing, but as a reshaping of lives, a reconnection to community, and as an ethical and equitable “right to the city”. This “Right to the City” has underpinned the Common Ground approach, emerging in a range of cities and adopted in South Brisbane, Queensland Australia. This paper examines the Common Ground approach and the impacts on its residents and in the community with a view to exploring further developments in this direction. A clear understanding of these lessons underpins, and should inform, a new approach to reconnecting the displaced and to developing solutions that not only enhance their lives but also the community at large.

  5. Seville City Hall Chapter Room ceiling decoration

    Directory of Open Access Journals (Sweden)

    Robador, M. D.

    2010-02-01

    Full Text Available The present article describes a chemical and physical study of the colour, chemical composition and mineral phases of the decorative materials in the Seville City Hall Chapter House ceiling. The findings showed that the inner most layer of material, calcite, was covered with white lead, in turn concealed under a layer of gilded bole. The ceiling underwent re-gilding, also over bole, due in all likelihood to wear on the original gold leaf. In the nineteenth century, the entire ceiling with the exception of the inscriptions was whitewashed with calcite and white lead. Silver was employed on King John I’s sword (coffer 27. Gold leaf was used to adorn the royal attributes: crowns, belts, sceptres, swords and rosary beads. The high reliefs were likewise gilded. The pigments identified on the ceiling adornments included azurite, malachite, vermilion and gas black. A lime and ground dolomite mortar was used throughout.

    El objetivo de este trabajo es el estudio de diferentes aspectos, como el color, la composición química y las fases mineralógicas presentes en los diferentes materiales que forman la ornamentación del techo de la Sala Capitular del Ayuntamiento de Sevilla, mediante métodos físicos y químicos. Nuestros resultados muestran que el dorado fue realizado sobre una capa de bol previamente depositada sobre una lámina de blanco de plomo que cubría un estrato de calcita. Posteriormente, y probablemente debido a alteraciones en el dorado original, el techo fue de nuevo dorado usando una técnica similar. En el siglo XIX, casi todo el techo, excepto las zonas con inscripciones, fue blanqueado usando una mezcla de calcita y blanco de plomo. Se empleó plata para cubrir la espada del rey Juan I (casetón 27. Finísimas láminas de oro se usaron para decorar los atributos reales: coronas, cinturones, cetros, espadas y rosarios. En diferentes partes de la decoración fueron detectados pigmentos como azurita, malaquita, bermellón y

  6. Stop Tobacco in Restaurants: Fifth Grade Students STIR City Hall

    Science.gov (United States)

    Morris, Ronald Vaughan

    2008-01-01

    This article discusses a campaign called STIR: Stop Tobacco in Restaurants, that was started by fourth and fifth grade students. The goal was to end smoking in public places, including restaurants, bowling alleys, sports bars, and pool halls. For two years they motivated their peers, coordinated an information campaign to urge kids and adults to…

  7. CPT 2004 BRISBANE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Dear Colleagues, On behalf of the National Organizing Committee I am delighted to invite you to CPT2004 which will be hosted by the Australian Society of Clinical and Experimental Pharmacologists and Toxicologists (ASCEPT) and the Division of Clinical Pharmacology of IUPHAR. The South East Asian Western Pacific regional grouping of pharmacologists will be extensively involved. Major areas to be covered in an exciting scientific program will include drug discovery and development, the latest advances in therapeutic areas, clinical toxicology, pharmacogenomics, political and social pharmacology, education, quality use of medicines, pharmacoepidemiology and pharmacoeconomics. We will provide an outstanding social program and give your accompanying persons a personal welcome and sense of involvement. The 18th World Congress of the Intemational Society for Heart Research (ISHR) will be held at the same venue in Brisbane directly following CPT2004, and the programs will be coordinated to facilitate attendance at both meetings. Come to CPT2004 in Australia and enjoy our unique environment, and attractions that are as varied as skiing in August, Ulum (Ayers Rock) and the Great Barrier Reef. For any further enquiries, please contact: CPT2004 Secretariat, GPO Box 2609 Sydney NSW 2001 Australia Tel: +61-2-9241 1478 Fax: + 61-2-9521 3552 E-mail: reply@icmsaust. com. auIntemet: www. cpt @ icmsaust. com. au

  8. Study and Constructive Analysis of Deinze’s New City Hall

    OpenAIRE

    LATORRE ZAPLANA, LUIS

    2015-01-01

    [EN] This bachelor’s thesis develops the analysis of the construction works of the New City Hall in Deinze, Belgium. The study includes the organizational plan, the sections of the building general plant, the development of some of the constructive details, a detailed technical study of insulating elements, a comparative study between prefabricated columns and "in situ" built columns and the scheduling of tasks in a Gantt chart. [ES] En este TFG se desarrolla el análisis de las obras de co...

  9. Leadership Strategies in Promoting the Image of the Mayors on the Websites of Sector Town Halls and of Bucharest City Hall

    Directory of Open Access Journals (Sweden)

    Viorica PĂUȘ

    2016-02-01

    Full Text Available The research deals with the leadership strategies used by the mayors of the six sectors and the General Mayor of Bucharest in order to represent and promote the organizational image and their own image. The success, performance and competitiveness of sector town halls and Bucharest City Hall also depend on the quality of leadership and the leaders’ ability to use appropriate, attractive and customized online communication strategies in order to inform the citizens and achieve their electoral goals. This research has the following objectives: (a to identify the online strategies used by the seven mayors-leaders; (b to identify the salience of tactics used by the seven mayors; (c to identify the ethos categories within the mayors’ online messages.

  10. Evaluating integrated urban water systems alternatives for Brisbane, Australia.

    Science.gov (United States)

    Mitchell, G; Gray, S; Shipton, B; Woolley, R; Erbacher, J; Egerton, G; McKnoulty, J

    2003-01-01

    The Brazil Development Study investigates the feasibility of alternative approaches to providing sustainable water services to a 226 ha mixed residential and industrial greenfield development within the city of Brisbane, Australia. The alternatives include techniques such a the use of rainwater tanks, water use efficiency, a local wastewater treatment plant for recycling of reclaimed water and composting toilets amongst others. This paper evaluates a series of urban development scenarios against the objectives of the study. The insights gained into the drivers for cost and environmental impact for this particular site are discussed as well as a number of issues of concern and challenges to Council and the community.

  11. Characterization of Compounds Formed and added on surface of outdoor Seville city hall

    Science.gov (United States)

    Robador, Maria Dolores; Alcalde, Manuel; Arroyo, Fatima; Albardonedo, Antonio; Perez-Rodriguez, Jose Luis

    2013-04-01

    The building of the City Hall of Seville constitutes one of the samples more important of the architecture plateresque in Andalusia. For centuries the stone façade has suffered different stages of restoration. These treatments joined the effects of the environmental pollution are responsible for formation and deposition of different chemical compounds on the surface of the monuments. This study will supply information of the environmental effects on the rock, and the treatments that have been performed in previous interventions. The petrographic study showed the presence of a carbonate rock of thin grain constituted essentially by bioclastos and fine sand. The study by scanning electron microscopy showed a compact and continuous cover that suggested a polymer layer. The infrared spectroscopy study confirmed presence of acrylic resin. This resin covered sometimes a black crust constituted by alkanes characterized by mass spectrometry. In addition was found nodules constitutes by C, Ca, Fe, Si and Ca. These compounds appeared with gypsum and were attributed to environment contamination produced by combustion. Materials were observed that cover volumetric lagoons for losses of pieces or were used to fix fragments of stones that were free or displaced. The study by X-ray diffraction and infrared spectroscopy confirmed the presence of gypsum. Mortars constituted by calcite (60%) and inert material (40%; mainly quartz, feldspar and mica) were also characterized. In flute of the stone was found a black crust under which appeared a yellowish layer. The portable X-ray fluorescence and X-ray diffraction confirmed the presence of gypsum produced by environmental contamination. Gypsum was also found in the interior of the stone confirming that this mineral has emigrated due the high porosity of the stone. In some zones of the façade was detected some possible wall paintings. Cross-sections were prepared and studied by optical and scanning electron microscopes. A layer of

  12. Exploratory Analysis of Customer Satisfaction in Case of Cluj-Napoca City Hall Social Canteen

    Directory of Open Access Journals (Sweden)

    Horia M. RABOCA

    2009-02-01

    Full Text Available This study is an exploratory analysis ofcustomers’ satisfaction with regard to the servicesprovided to people on welfare by the socialcanteen organized by Cluj-Napoca City Hall. Inaddition to assessing customers’ satisfaction, italso aims to highlight the main factors influencingthe satisfaction level. The satisfaction modelwas constructed and tested on the results of asurvey conducted among the people benefiting theservices from the institution mentioned.The questionnaire’s structure allows for theassessment of satisfaction construct and role, andpays attention to the influence that quality attributesand client expectations have on satisfaction,revealing that these directly and significantly affectthe level of customers’ satisfaction.Univariate statistical analysis of data andstructural model analysis are used to emphasizethe attributes of the quality of service that affect toa high extent customer satisfaction and that can beused at managerial level to increase service qualityin order to achieve higher customer satisfaction.Also from the managerial point of view, thestudy has a dual significance. It is linked to theconcerns for ensuring and improving the qualityof services in order to increase the customers’satisfaction, as well as to concerns about theimage of the institution.

  13. Technical Note: Alterations in the stone masonry of the Capitol Room of Sevilla City Hall

    Directory of Open Access Journals (Sweden)

    García Navarro, J.

    2006-12-01

    Full Text Available The main aim of this work has been to determine the causes of stone loss (small particles and one larger piece and mortar loss in the coffered vault of the Capitol Room in the City Hall of Seville. The analyses and assays carried out during the course of this research have revealed that this masonry comprises a covering of oil paints over mortar-stucco of calcite, quartz, gypsum,and lead white with linseed oil when the walls were not covered. In addition, it was confirmed that the installation of air-conditioning caused a change in the humidity and temperature in the vault, aggravated by the elimination of the cross-ventilation that the structure had since it was built. The combination of these two circumstances likely triggered the pathology in the masonry.Este trabajo ha tenido como objetivo principal determinarlas causas que han originado desprendimientos de partículas y un fragmento importante de las piedras y del mortero que conforman la bóveda-artesonado de la Sala Capitular del Ayuntamiento de Sevilla. Los diferentes análisis y ensayos realizados evidencian que estas fábricas tienen un revestimiento realizado a base de pinturas al óleo sobre estuco-mortero de calcita, cuarzo, yeso y presencia de blanco de plomo con impregnación de aceite de linaza, en tanto que las fábricas de los muros no tienen revestimiento alguno. Igualmente se ha constatado el cambio de la humedad-temperatura ambiental en la bóveda, generado por la implantación de aire acondicionado y la eliminación de la ventilación cruzada natural que tenía desde su construcción. La conjunción de ambas acciones parece ser el desencadenante de las anomalías reseñadas.

  14. Excess deaths during the 2004 heatwave in Brisbane, Australia.

    Science.gov (United States)

    Tong, Shilu; Ren, Cizao; Becker, Niels

    2010-07-01

    The paper examines whether there was an excess of deaths and the relative role of temperature and ozone in a heatwave during 7-26 February 2004 in Brisbane, Australia, a subtropical city accustomed to warm weather. The data on daily counts of deaths from cardiovascular disease and non-external causes, meteorological conditions, and air pollution in Brisbane from 1 January 2001 to 31 October 2004 were supplied by the Australian Bureau of Statistics, Australian Bureau of Meteorology, and Queensland Environmental Protection Agency, respectively. The relationship between temperature and mortality was analysed using a Poisson time series regression model with smoothing splines to control for nonlinear effects of confounding factors. The highest temperature recorded in the 2004 heatwave was 42 degrees C compared with the highest recorded temperature of 34 degrees C during the same periods of 2001-2003. There was a significant relationship between exposure to heat and excess deaths in the 2004 heatwave [estimated increase in non-external deaths: 75 ([95% confidence interval, CI: 11-138; cardiovascular deaths: 41 (95% CI: -2 to 84)]. There was no apparent evidence of substantial short-term mortality displacement. The excess deaths were mainly attributed to temperature but exposure to ozone also contributed to these deaths.

  15. Depicting ‘Natural’ Disasters in U.S.-American History and Culture: San Francisco’s City Hall as an Icon of the 1906 Earthquake and Fire

    Directory of Open Access Journals (Sweden)

    Leikam, Susanne

    2009-01-01

    Full Text Available The article examines the role that visual representations of San Francisco’s first City Hall played in the aftermath of the 1906 Earthquake and Fire. Not only did they offer a projection screen for the collective trauma but they also provided a starting point for recollection and re-enactment. With the City Hall vicinity as an example, it is further shown that what was perceived at the time as nature’s obliteration of the metropolis was rather a man-made disaster.

  16. COMMUNICATION THROUGH WEBSITES ACHIEVED BY THE CITY HALLS OF PITESTI, BRAILA AND RÂMNICU-VÂLCEA

    Directory of Open Access Journals (Sweden)

    Elena, Enache

    2013-01-01

    Full Text Available Communication has a key role in the socio-economic and cultural-scientific relations, its quality largely leading to success in relations between individuals, between communities. Nowadays, increasingly more, the communication is based on the Internet development, a giant support with informational feature that connects thousands of local networks, keeping in touch millions of people around the world.Internet is a peak of communication: a world in which information transmission costs almost nothing, in which the distance is irrelevant and a lot of information is available. In order to reach its goal, this new mean of communication is equally affordable for an amateur and also for an informatics professional.The paper aims to investigate how the local government (Pite ti, Br ila and Râmnicu-Vâlcea city halls understood the importance of communication through the Internet, which facilitates interaction with external audiences and seek solutions in this way, one of them being the website.

  17. Increased risk of emergency hospital admissions for children with renal diseases during heatwaves in Brisbane, Australia

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yu Wang; Adrian Barnett; Yu-Ming Guo; Wei-Wei Yu; Xiao-Ming Shen; Shi-Lu Tong

    2014-01-01

    Background: Heatwaves have a significant impact on population health including both morbidity and mortality. In this study we examined the association between heatwaves and emergency hospital admissions (EHAs) for renal diseases in children (aged 0-14 years) in Brisbane, Australia. Methods: Daily data on EHAs for renal diseases in children and exposure to temperature and air pollution were obtained for Brisbane city from January 1, 1996 to December 31, 2005. A time-stratified case-crossover design was used to compare the risks for renal diseases between heatwave and non-heatwave periods. Results: There were 1565 EHAs for renal diseases in children during the study period. Heatwaves exhibited a signifi cant impact on EHAs for renal diseases in children after adjusting for confounding factors (odds ratio: 3.6; 95% confidence interval: 1.4-9.5). The risk estimates differed with lags and the use of different heatwave defi nitions. Conclusions: There was a significant increase in EHAs for renal diseases in children during heatwaves in Brisbane, a subtropical city where people are well accustomed to warm weather. This finding may have significant implications for pediatric renal care, particularly in subtropical and tropical regions.

  18. Central Places of Transit Riders: A Visual Story of Brisbane, Australia

    Directory of Open Access Journals (Sweden)

    Ming Wei

    2016-01-01

    Full Text Available This study uses smartcard data to quantify and visualize the most popular destinations (‘central places’ and corridors of transit riders in Brisbane, an emerging global city in Queensland, Australia. It shows that the number and distribution of central places vary significantly across different periods of the day and so are their respective scopes of influence, which are measured by a standard deviational ellipse, and the associated transit corridors, which connect visitors of central places to other locales in the city. As a whole, this study shows the potential of smartcard data in efficiently verifying and even extending existing economic geography theories, models or concepts.

  19. Informal urban green-space: comparison of quantity and characteristics in Brisbane, Australia and Sapporo, Japan.

    Directory of Open Access Journals (Sweden)

    Christoph D D Rupprecht

    Full Text Available Informal urban green-space (IGS such as vacant lots, brownfields and street or railway verges is receiving growing attention from urban scholars. Research has shown IGS can provide recreational space for residents and habitat for flora and fauna, yet we know little about the quantity, spatial distribution, vegetation structure or accessibility of IGS. We also lack a commonly accepted definition of IGS and a method that can be used for its rapid quantitative assessment. This paper advances a definition and typology of IGS that has potential for global application. Based on this definition, IGS land use percentage in central Brisbane, Australia and Sapporo, Japan was systematically surveyed in a 10×10 km grid containing 121 sampling sites of 2,500 m2 per city, drawing on data recorded in the field and aerial photography. Spatial distribution, vegetation structure and accessibility of IGS were also analyzed. We found approximately 6.3% of the surveyed urban area in Brisbane and 4.8% in Sapporo consisted of IGS, a non-significant difference. The street verge IGS type (80.4% of all IGS dominated in Brisbane, while lots (42.2% and gaps (19.2% were the two largest IGS types in Sapporo. IGS was widely distributed throughout both survey areas. Vegetation structure showed higher tree cover in Brisbane, but higher herb cover in Sapporo. In both cities over 80% of IGS was accessible or partly accessible. The amount of IGS we found suggests it could play a more important role than previously assumed for residents' recreation and nature experience as well as for fauna and flora, because it substantially increased the amount of potentially available greenspace in addition to parks and conservation greenspace. We argue that IGS has potential for recreation and conservation, but poses some challenges to urban planning. To address these challenges, we propose some directions for future research.

  20. Informal urban green-space: comparison of quantity and characteristics in Brisbane, Australia and Sapporo, Japan.

    Science.gov (United States)

    Rupprecht, Christoph D D; Byrne, Jason A

    2014-01-01

    Informal urban green-space (IGS) such as vacant lots, brownfields and street or railway verges is receiving growing attention from urban scholars. Research has shown IGS can provide recreational space for residents and habitat for flora and fauna, yet we know little about the quantity, spatial distribution, vegetation structure or accessibility of IGS. We also lack a commonly accepted definition of IGS and a method that can be used for its rapid quantitative assessment. This paper advances a definition and typology of IGS that has potential for global application. Based on this definition, IGS land use percentage in central Brisbane, Australia and Sapporo, Japan was systematically surveyed in a 10×10 km grid containing 121 sampling sites of 2,500 m2 per city, drawing on data recorded in the field and aerial photography. Spatial distribution, vegetation structure and accessibility of IGS were also analyzed. We found approximately 6.3% of the surveyed urban area in Brisbane and 4.8% in Sapporo consisted of IGS, a non-significant difference. The street verge IGS type (80.4% of all IGS) dominated in Brisbane, while lots (42.2%) and gaps (19.2%) were the two largest IGS types in Sapporo. IGS was widely distributed throughout both survey areas. Vegetation structure showed higher tree cover in Brisbane, but higher herb cover in Sapporo. In both cities over 80% of IGS was accessible or partly accessible. The amount of IGS we found suggests it could play a more important role than previously assumed for residents' recreation and nature experience as well as for fauna and flora, because it substantially increased the amount of potentially available greenspace in addition to parks and conservation greenspace. We argue that IGS has potential for recreation and conservation, but poses some challenges to urban planning. To address these challenges, we propose some directions for future research.

  1. Safety perceptions and behavior related to cycling in mixed traffic: A comparison between Brisbane and Copenhagen

    DEFF Research Database (Denmark)

    Chataway, Elijah Steven; Kaplan, Sigal; Nielsen, Thomas Alexander Sick;

    2014-01-01

    -based survey administered among cyclists in the two cities. Elicited items concerned perceived risk of infrastructure layouts, fear of traffic, cycling while distracted, use of safety gear, cycling avoidance due to feeling unsafe, and avoidance to cycle in mixed traffic conditions. The data were analyzed...... with structural equation models. Results show that, in comparison with cyclists in Copenhagen, cyclists in Brisbane perceive mixed traffic infrastructure layouts as less safe, feel more fear of traffic, and are more likely to adopt cycling avoidance as a coping strategy. Results also show that cyclists...

  2. The Effect of Selected Cleaning Techniques on Berkshire Lee Marble: A Scientific Study at Philadelphia City Hall

    Science.gov (United States)

    Mossotti, Victor G.; Eldeeb, A. Raouf; Fries, Terry L.; Coombs, Mary Jane; Naude, Virginia N.; Soderberg, Lisa; Wheeler, George S.

    2002-01-01

    This report describes a scientific investigation of the effects of eight different cleaning techniques on the Berkshire Lee marble component of the facade of the East Center Pavilion at Philadelphia City Hall; the study was commissioned by the city of Philadelphia. The eight cleaning techniques evaluated in this study were power wash (proprietary gel detergent followed by water rinse under pressure), misting (treatment with potable, nebulized water for 24-36 hours), gommage (proprietary Thomann-Hanry low-pressure, air-driven, small-particle, dry abrasion), combination (gommage followed by misting), Armax (sodium bicarbonate delivered under pressure in a water wash), JOS (dolomite powder delivered in a low-pressure, rotary-vortex water wash), laser (thermal ablation), and dry ice (powdered-dry-ice abrasion delivered under pressure). In our study approximately 160 cores were removed from the building for laboratory analysis. We developed a computer program to analyze scanning-electron-micrograph images for the microscale surface roughness and other morphologic parameters of the stone surface, including the near-surface fracture density of the stone. An analysis of more than 1,100 samples cut from the cores provided a statistical basis for crafting the essential elements of a reduced-form, mixed-kinetics conceptual model that represents the deterioration of calcareous stone in terms of self-organized soiling and erosion patterns. This model, in turn, provided a basis for identifying the variables that are affected by the cleaning techniques and for evaluating the extent to which such variables influence the stability of the stone. The model recognizes three classes of variables that may influence the soiling load on the stone, including such exogenous environmental variables as airborne moisture, pollutant concentrations, and local aerodynamics, and such endogenous stone variables as surface chemistry and microstructure (fracturing, roughness, and so on). This study

  3. The Brisbane Media Map: Participatory Design and Authentic Learning to Link Students and Industry

    Science.gov (United States)

    Collis, Christy; Foth, Marcus; Schroeter, Ronald

    2009-01-01

    The Brisbane Media Map is both an online resource and a tertiary-level authentic learning project. The Brisbane Media Map is an online database which provides a detailed overview of about 600 media industry organizations in Brisbane, Australia. In addition to providing contact details and synopses for each organization's profile, the Brisbane…

  4. The Brisbane Media Map: Participatory Design and Authentic Learning to Link Students and Industry

    Science.gov (United States)

    Collis, Christy; Foth, Marcus; Schroeter, Ronald

    2009-01-01

    The Brisbane Media Map is both an online resource and a tertiary-level authentic learning project. The Brisbane Media Map is an online database which provides a detailed overview of about 600 media industry organizations in Brisbane, Australia. In addition to providing contact details and synopses for each organization's profile, the Brisbane…

  5. The Brisbane Dental Hospital Building: "The Palace" An Era Ends.

    Science.gov (United States)

    Akers, Harry F; Foley, Michael A; Brown, John P

    2015-01-01

    Constitutional, educational, humanitarian and political considerations underpinned the design and construction of the Brisbane Dental Hospital Building, often colloquially referred to as "The Palace." The Queensland Heritage Council's listing of the Brisbane Dental Hospital Building on The Queensland Heritage Register in 1999 confirms the cultural significance of Nowland's architectural signature, the historical importance of the Wickham Park precinct and prior students' connection with the building. Influences on decisions determining the location, grand design and timing of construction of the Brisbane Dental Hospital Building emanated from a far bigger and largely unrecorded political picture. The authors argue that the political context in two tiers of government, the timing and nature of the proposal, town planning issues, the exigencies of the caries epidemic and Forgan Smith's post-Depression economic reconstruction across Queensland underpinned the project. Hanlon's personal attributes and disdain for the autonomy of the dental profession, together with his desire to reform dental education and to establish statewide government-administred dental clinics, were also relevant. Accordingly, the BDHD portrayed aspiration, purpose, symbolism, and vision. This paper, essentially an integration of dental and mainstream history, assembles and analyzes hitherto scattered and unpublished evidence to fill a gap in the current literature.

  6. Smoking habits of pregnant women in Brisbane, Australia.

    Science.gov (United States)

    Counsilman, J J; Mackay, E V

    1985-11-01

    A survey of postpartum women in Brisbane revealed that many gave up smoking just before or shortly after becoming pregnant, and that many of the remainder reduced their rate of consumption. Husbands who smoked showed no comparable changes in behaviour. Thus apparently many couples were aware of the dangers to the fetus of active smoking by the woman, but not of the dangers of her passive inhalation of smoke. Other significant findings included (i) increasing rates of consumption during successive pregnancies, (ii) high degrees of conformity for most habits (e.g. use of filters), and (iii) stronger addiction and earlier starting ages among heavy smokers than light smokers.

  7. The use of citizen’s charts on Local Administration: the case of the City Hall of Torrent. / El uso de las cartas de servicio en la administración local: el caso del Ayuntamiento de Torrent

    Directory of Open Access Journals (Sweden)

    Gonzalo Pardo Beneyto

    2016-10-01

    Full Text Available Public Administrations have suffered a sort of changes based in changing context and uncertainty. So, traditional Weberian bureaucracy has been adapting itself, embracing new values and tools. In this way, the City Hall of Torrent has developed the strategy called Torrent INNOVA. It was framed inside a quality management system named EVAM framework. Thereby, citizen’s charts are an important instrument in order to manage local context and apply new public administrative innovations.

  8. Residents’ Experiences of Privacy and Comfort in Multi-Storey Apartment Dwellings in Subtropical Brisbane

    Directory of Open Access Journals (Sweden)

    Rosemary Kennedy

    2015-06-01

    Full Text Available Dwellings in multi-storey apartment buildings (MSAB are predicted to increase dramatically as a proportion of housing stock in subtropical cities over coming decades. The problem of designing comfortable and healthy high-density residential environments and minimising energy consumption must be addressed urgently in subtropical cities globally. This paper explores private residents’ experiences of privacy and comfort and their perceptions of how well their apartment dwelling modulated the external environment in subtropical conditions through analysis of 636 survey responses and 24 interviews with residents of MSAB in inner urban neighbourhoods of Brisbane, Australia. The findings show that the availability of natural ventilation and outdoor private living spaces play important roles in resident perceptions of liveability in the subtropics where the climate is conducive to year round “outdoor living”. Residents valued choice with regard to climate control methods in their apartments. They overwhelmingly preferred natural ventilation to manage thermal comfort, and turned to the air-conditioner for limited periods, particularly when external conditions were too noisy. These findings provide a unique evidence base for reducing the environmental impact of MSAB and increasing the acceptability of apartment living, through incorporating residential attributes positioned around climate-responsive architecture.

  9. Hall C

    Data.gov (United States)

    Federal Laboratory Consortium — Hall C's initial complement of equipment (shown in the figure), includes two general-purpose magnetic spectrometers. The High Momentum Spectrometer (HMS) has a large...

  10. Hall A

    Data.gov (United States)

    Federal Laboratory Consortium — The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electroand photo-induced reactions at very high luminosity...

  11. Difference in mosquito species (Diptera: Culicidae) and the transmission of Ross River virus between coastline and inland areas in Brisbane, Australia.

    Science.gov (United States)

    Hu, W; Mengersen, K; Dale, P; Tong, S

    2010-02-01

    This study examined the distribution of major mosquito species and their roles in the transmission of Ross River virus (RRV) infection for coastline and inland areas in Brisbane, Australia (27 degrees 28' S, 153 degrees 2' E). We obtained data on the monthly counts of RRV cases in Brisbane between November 1998 and December 2001 by statistical local areas from the Queensland Department of Health and the monthly mosquito abundance from the Brisbane City Council. Correlation analysis was used to assess the pairwise relationships between mosquito density and the incidence of RRV disease. This study showed that the mosquito abundance of Aedes vigilax (Skuse), Culex annulirostris (Skuse), and Aedes vittiger (Skuse) were significantly associated with the monthly incidence of RRV in the coastline area, whereas Aedes vigilax, Culex annulirostris, and Aedes notoscriptus (Skuse) were significantly associated with the monthly incidence of RRV in the inland area. The results of the classification and regression tree (CART) analysis show that both occurrence and incidence of RRV were influenced by interactions between species in both coastal and inland regions. We found that there was an 89% chance for an occurrence of RRV if the abundance of Ae. vigilax was between 64 and 90 in the coastline region. There was an 80% chance for an occurrence of RRV if the density of Cx. annulirostris was between 53 and 74 in the inland area. The results of this study may have applications as a decision support tool in planning disease control of RRV and other mosquito-borne diseases.

  12. 从重庆湖广会馆管窥山城会馆园林特征%Analysis of the Features of Guild Hall Gardens in the Mountain City Chongqing——With Huguang Guild Hall as an Example

    Institute of Scientific and Technical Information of China (English)

    孙春红; 魏勇军

    2011-01-01

    以重庆湖广会馆为例,在前人的基础上,对会馆园林进行了概念上的界定.从相地选址、环境特征两个层面进行探究,以摸清会馆园林与中国古典主流园林类型的区别与联系,明确山城会馆园林的特征,进而挖掘我国这一特有的园林文化及对现代商务会所园林景观设计的借鉴意义.%With Chongqing Huguang Guild Hall as an example, this paper attempts to make a conceptual definition of guild hall gardens on the basis of the work of previous researchers.According to the study of location selection and environmental features, the differences and the interconnections between guild hall gardens and the main types of Chinese classical gardens are discussed so as to excavate the unique garden culture of our country and provide useful ,information for landscape design of modern business clubs.

  13. Radon and thoron concentrations in public workplaces in Brisbane, Australia.

    Science.gov (United States)

    Alharbi, Sami H; Akber, Riaz A

    2015-06-01

    Radon and thoron are radioactive gases that can emanate from soil and building materials, and it can accumulate in indoor environments. The concentrations of radon and thoron in the air from various workplace categories in Brisbane, Australia were measured using an active method. The average radon and thoron concentrations for all workplace categories were 10.5 ± 11.3 and 8.2 ± 1.4 Bq m(-3), respectively. The highest radon concentration was detected in a confined area, 86.6 ± 6.0 Bq m(-3), while the maximum thoron level was found in a storage room, 78.1 ± 14.0 Bq m(-3). At each site, the concentrations of radon and thoron were measured at two heights, 5 cm and 120 cm above the floor. The effect of the measurement heights on the concentration level was significant in the case of thoron. The monitoring of radon and thoron concentrations showed a lower radon concentration during work hours than at other times of the day. This can be attributed to the ventilation systems, including the air conditioner and natural ventilation, which normally operate during work hours. The diurnal variation was less observed in the case of thoron, as the change in its concentration during and after the working hours was insignificant. The study also investigated the influence of the floor level and flooring type on indoor radon and thoron concentrations. The elevated levels of radon and thoron were largely found in basements and ground floor levels and in rooms with concrete flooring.

  14. Dental health of aboriginal pre-school children in Brisbane, Australia.

    Science.gov (United States)

    Seow, W K; Amaratunge, A; Bennett, R; Bronsch, D; Lai, P Y

    1996-06-01

    This investigation studied the dental health status of a group of 184 Australian Aboriginal children with a mean age of 4.4 +/- 0.8 years, who were attending pre-schools in metropolitan Brisbane, a non-fluoridated state capital city. The DDE (Developmental Defects of Enamel) Index was used to chart enamel hypoplasia and enamel opacities. WHO criteria was used to diagnose dental caries. The results showed that 98% of children had at least one tooth showing developmental enamel defects. Each child had a mean of 3.8 +/- 1.7 teeth affected by enamel hypoplasia and another 1.1 +/- 0.8 teeth affected by enamel opacity. Seventy-eight percent of the children had dental caries. The mean number of decayed, missing, filled teeth (dmft) per child was 3.8 +/- 3.7. The decayed component constituted 3.5 (95%) of the mean dmft, indicating a high unmet restorative need in this group. The mean dmfs (decayed, missing, filled, surfaces) was 5.9 +/- 7.3. Maxillary anterior labial decay of at least one tooth affected 43 (23%) of the children. In this sub-group, the dmft and dmfs was 9.1 +/- 2.8 and 15.4 +/- 7.7 respectively. Oral debris was found in 98% of the children. It is hypothesized that the high levels of underlying developmental enamel defects, compounded by low fluoride exposure, poor oral hygiene and a diet high in refined sugars pose an important caries risk factor in this group of children.

  15. A New Definition in Atlanta: Q&A with Beverly Hall

    Science.gov (United States)

    Crow, Tracy

    2010-01-01

    Beverly Hall has been superintendent of Atlanta Public Schools since 1999. Before coming to Atlanta, Hall was state district superintendent of Newark Public Schools, deputy chancellor for instruction of New York City Public Schools, superintendent of Community School District 27 in New York City, and a principal in Brooklyn. Hall chairs Harvard…

  16. Healthy Dining Hall Eating

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Healthy Dining Hall Eating KidsHealth > For Teens > Healthy Dining Hall Eating ... likely to eat. previous continue Overcoming Common Dining Hall Mistakes Even the most attentive diners can still ...

  17. The Coordination Game between Concept and Construction Research on the Tectonic Strategies of Two City Halls%概念与建造的博弈 两个市政厅的建构策略研究

    Institute of Scientific and Technical Information of China (English)

    余国璞

    2012-01-01

    This article compares the tectonic strategies of two city halls designed by the Spanisharchitect Alejandro de la Sota and his proteges at S-M.A.O. It aims to explore the interplay between concept and construction in the design process and its influences on the finished architecture.%文章以西班牙建筑师阿里杭德罗·德拉索塔及其后辈S-M.A.O.事务所设计的两个市政厅为研究对象,分析比较了两者建构策略的异同,并对建筑设计中概念与建造的博弈及其对建筑建成状态的影响进行了探讨。

  18. Angry young architects: Counterculture and the critique of modernism in Brisbane, 1967-72

    NARCIS (Netherlands)

    Gosseye, J.

    2014-01-01

    By 1967, Brisbane architecture students had had enough. Disenchantment with their “out-dated” architectural education and the rigidity of the Australian architectural establishment opened out onto the wider context of the Moratorium opposing the Vietnam War, and the peculiarly conservative and react

  19. Angry young architects: Counterculture and the critique of modernism in Brisbane, 1967-72

    NARCIS (Netherlands)

    Gosseye, J.

    2014-01-01

    By 1967, Brisbane architecture students had had enough. Disenchantment with their “out-dated” architectural education and the rigidity of the Australian architectural establishment opened out onto the wider context of the Moratorium opposing the Vietnam War, and the peculiarly conservative and react

  20. Cities, Towns and Villages, Waverly Hall, Published in 2007, 1:100000 (1in=8333ft) scale, River Valley Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Cities, Towns and Villages dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Road Centerline Files information as of 2007. It...

  1. Characterisation of the impact of open biomass burning on urban air quality in Brisbane, Australia.

    Science.gov (United States)

    He, Congrong; Miljevic, Branka; Crilley, Leigh R; Surawski, Nicholas C; Bartsch, Jennifer; Salimi, Farhad; Uhde, Erik; Schnelle-Kreis, Jürgen; Orasche, Jürgen; Ristovski, Zoran; Ayoko, Godwin A; Zimmermann, Ralf; Morawska, Lidia

    2016-05-01

    Open biomass burning from wildfires and the prescribed burning of forests and farmland is a frequent occurrence in South-East Queensland (SEQ), Australia. This work reports on data collected from 10 to 30 September 2011, which covers the days before (10-14 September), during (15-20 September) and after (21-30 September) a period of biomass burning in SEQ. The aim of this project was to comprehensively quantify the impact of the biomass burning on air quality in Brisbane, the capital city of Queensland. A multi-parameter field measurement campaign was conducted and ambient air quality data from 13 monitoring stations across SEQ were analysed. During the burning period, the average concentrations of all measured pollutants increased (from 20% to 430%) compared to the non-burning period (both before and after burning), except for total xylenes. The average concentration of O3, NO2, SO2, benzene, formaldehyde, PM10, PM2.5 and visibility-reducing particles reached their highest levels for the year, which were up to 10 times higher than annual average levels, while PM10, PM2.5 and SO2 concentrations exceeded the WHO 24-hour guidelines and O3 concentration exceeded the WHO maximum 8-hour average threshold during the burning period. Overall spatial variations showed that all measured pollutants, with the exception of O3, were closer to spatial homogeneity during the burning compared to the non-burning period. In addition to the above, elevated concentrations of three biomass burning organic tracers (levoglucosan, mannosan and galactosan), together with the amount of non-refractory organic particles (PM1) and the average value of f60 (attributed to levoglucosan), reinforce that elevated pollutant concentration levels were due to emissions from open biomass burning events, 70% of which were prescribed burning events. This study, which is the first and most comprehensive of its kind in Australia, provides quantitative evidence of the significant impact of open biomass burning

  2. Mary E. Hall: Dawn of the Professional School Librarian

    Science.gov (United States)

    Alto, Teresa

    2012-01-01

    A century ago, a woman named Mary E. Hall convinced school leaders of the need for the professional school librarian--a librarian who cultivated a love of reading, academic achievement, and independent learning skills. After graduating from New York City's Pratt Institute Library School in 1895, Hall developed her vision for the high school…

  3. Sexual and reproductive health communication among Sudanese and Eritrean women: an exploratory study from Brisbane, Australia.

    Science.gov (United States)

    Rogers, Claire; Earnest, Jaya

    2015-01-01

    This exploratory study piloted in Brisbane, Australia, reports on findings from in-depth focus-group discussions conducted with Sudanese and Eritrean women in Brisbane. We investigated and documented their experiences and knowledge of sexual and reproductive health and contraception, and explored their views on sexuality and relationships education within the family environment of minority ethnic communities in Australia. Underpinned by a qualitative psychosocial framework, the study also involved key-informant interviews with health and multicultural not-for-profit sector professionals. Through the knowledge and experiences shared by the participants, the key themes of cultural insensitivity, exclusion and poor communication within the family were highlighted by participants as determining factors in the achievement of sexual and reproductive health and good quality sex and relationships education. Participants proposed recommendations for how minority ethnic communities in Australia can more effectively support and communicate within the family environment to increase their own and their children's knowledge and understanding.

  4. Social change or business as usual at city hall? Examining an urban municipal government's response to neighbourhood-level health inequities.

    Science.gov (United States)

    Cahuas, Madelaine C; Wakefield, Sarah; Peng, Yun

    2015-05-01

    There is a renewed interest in the potential of municipal governments working collaboratively with local communities to address health inequities. A growing body of literature has also highlighted the benefits and limitations of participatory approaches in neighbourhood interventions initiated by municipal governments. However, few studies have investigated how neighbourhood interventions tackling health inequities work in real-time and in context, from the perspectives of Community Developers (CDs) who promote community participation. This study uses a process evaluation approach and semi-structured interviews with CDs to explore the challenges they face in implementing a community development, participatory process in the City of Hamilton's strategy to reduce health inequities - Neighbourhood Action. Findings demonstrate that municipal government can facilitate and suppress community participation in complex ways. CDs serve as significant but conflicted intermediaries as they negotiate and navigate power differentials between city and community actors, while also facing structural challenges. We conclude that community participation is important to bottom-up, resident-led social change, and that CDs are central to this work. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Correlation or Causality between Land Cover Patterns and the Urban Heat Island Effect? Evidence from Brisbane, Australia

    Directory of Open Access Journals (Sweden)

    Kaveh Deilami

    2016-08-01

    Full Text Available Numerous studies have identified associations between the surface urban heat island (SUHI effect (i.e., SUHI, hereinafter is referred to as UHI and urban growth, particularly changes in land cover patterns. This research questions their causal links to answer a key policy question: If cities restrict urban expansion and encourage people to live within existing urban areas, will that help in controlling UHI? The question has been answered by estimating four models using data from Brisbane, Australia: Model 1—cross-sectional ordinary least square (OLS regression—to examine the association between the UHI effect and land cover patterns in 2013; Model 2—cross-sectional geographically weighted regression (GWR—to examine whether the outputs generated from Model 1 possess significant spatial variations; Model 3—longitudinal OLS—to examine whether changes in land cover patterns led to changes in UHI effects between 2004 and 2013; and Model 4—longitudinal GWR—to examine whether the outputs generated from Model 3 vary significantly over space. All estimations were controlled for potential confounding effects (e.g., population, employment and dwelling densities. Results from the cross-sectional OLS and GWR models were consistent with previous findings and showed that porosity is negatively associated with the UHI effect in 2013. In contrast, population density has a positive association. Results from the longitudinal OLS and GWR models confirm their causal linkages and showed that an increase in porosity level reduced the UHI effect, whereas an increase in population density increased the UHI effect. The findings suggest that even a containment of population growth within existing urban areas will lead to the UHI effect. However, this can be significantly minimized through proper land use planning, by creating a balance between urban and non-urban uses of existing urban areas.

  6. Characterisation of chemical composition and energy content of green waste and municipal solid waste from Greater Brisbane, Australia.

    Science.gov (United States)

    Hla, San Shwe; Roberts, Daniel

    2015-07-01

    The development and deployment of thermochemical waste-to-energy systems requires an understanding of the fundamental characteristics of waste streams. Despite Australia's growing interest in gasification of waste streams, no data are available on their thermochemical properties. This work presents, for the first time, a characterisation of green waste and municipal solid waste in terms of chemistry and energy content. The study took place in Brisbane, the capital city of Queensland. The municipal solid waste was hand-sorted and classified into ten groups, including non-combustibles. The chemical properties of the combustible portion of municipal solid waste were measured directly and compared with calculations made based on their weight ratios in the overall municipal solid waste. The results obtained from both methods were in good agreement. The moisture content of green waste ranged from 29% to 46%. This variability - and the tendency for soil material to contaminate the samples - was the main contributor to the variation of samples' energy content, which ranged between 7.8 and 10.7MJ/kg. The total moisture content of food wastes and garden wastes was as high as 70% and 60%, respectively, while the total moisture content of non-packaging plastics was as low as 2.2%. The overall energy content (lower heating value on a wet basis, LHVwb) of the municipal solid waste was 7.9MJ/kg, which is well above the World Bank-recommended value for utilisation in thermochemical conversion processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Quantum Spin Hall Effect

    Energy Technology Data Exchange (ETDEWEB)

    Bernevig, B.Andrei; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-01-15

    The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of 2 e/4{pi}. The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new state of matter has many profound correlated properties described by a topological field theory.

  8. Assessment of heat-related health impacts in Brisbane, Australia: comparison of different heatwave definitions.

    Directory of Open Access Journals (Sweden)

    Shilu Tong

    Full Text Available BACKGROUND: There is no global definition of a heatwave because local acclimatisation and adaptation influence the impact of extreme heat. Even at a local level there can be multiple heatwave definitions, based on varying temperature levels or time periods. We investigated the relationship between heatwaves and health outcomes using ten different heatwave definitions in Brisbane, Australia. METHODOLOGY/PRINCIPAL FINDINGS: We used daily data on climate, air pollution, and emergency hospital admissions in Brisbane between January 1996 and December 2005; and mortality between January 1996 and November 2004. Case-crossover analyses were used to assess the relationship between each of the ten heatwave definitions and health outcomes. During heatwaves there was a statistically significant increase in emergency hospital admissions for all ten definitions, with odds ratios ranging from 1.03 to 1.18. A statistically significant increase in the odds ratios of mortality was also found for eight definitions. The size of the heat-related impact varied between definitions. CONCLUSIONS/SIGNIFICANCE: Even a small change in the heatwave definition had an appreciable effect on the estimated health impact. It is important to identify an appropriate definition of heatwave locally and to understand its health effects in order to develop appropriate public health intervention strategies to prevent and mitigate the impact of heatwaves.

  9. Assessment of the health impacts of the 2011 summer floods in Brisbane.

    Science.gov (United States)

    Alderman, Katarzyna; Turner, Lyle R; Tong, Shilu

    2013-08-01

    To assess the effects of the 2011 floods in Brisbane, Australia, on residents' physical and mental health. Residents who had been affected by the floods completed a community-based survey that examined the direct impact of flooding on households and their perceived physical and mental health. Outcome variables included overall and respiratory health and mental health outcomes related to psychological distress, sleep quality, and posttraumatic stress disorder (PTSD). Multivariable logistic regression was used to examine the association between flooding and perceived health outcome variables, adjusted for current health status and sociodemographic factors. Residents whose households were directly affected by flooding were more likely to report poor overall (Odds Ratio [OR] 5.3; 95% CI, 2.8-10.1) and respiratory (OR 2.3; 95% CI, 1.1-4.6) health, psychological distress (OR 1.9; 95% CI, 1.1-3.5), poor sleep quality (OR 2.3; 95% CI, 1.2-4.4), and probable PTSD (OR 2.3; 95% CI, 1.2-4.5). The 2011 Brisbane floods had significant impact on the physical and psychosocial health of residents. Improved support strategies may need to be integrated into existing disaster management programs to reduce flood-related health impacts, particularly those related to mental health.

  10. Skyrmions and Hall Transport

    Science.gov (United States)

    Kim, Bom Soo; Shapere, Alfred D.

    2016-09-01

    We derive a generalized set of Ward identities that captures the effects of topological charge on Hall transport. The Ward identities follow from the (2 +1 )-dimensional momentum algebra, which includes a central extension proportional to the topological charge density. In the presence of topological objects like Skyrmions, we observe that the central term leads to a direct relation between the thermal Hall conductivity and the topological charge density. We extend this relation to incorporate the effects of a magnetic field and an electric current. The topological charge density produces a distinct signature in the electric Hall conductivity, which is identified in existing experimental data and yields further novel predictions. For insulating materials with translation invariance, the Hall viscosity can be directly determined from the Skyrmion density and the thermal Hall conductivity to be measured as a function of momentum.

  11. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  12. The first vineyard concert hall in North America

    Science.gov (United States)

    Jaffe, Christopher; Rivera, Carlos

    2002-11-01

    The first vineyard or surround concert hall designed and built in the Western Hemisphere is the Sala Nezahualcoyotl in Mexico City. The Hall was completed in 1976 and is part of the Cultural Center at the Universidad Nacional Autonoma de Mexico. The hall was named after a Toltec poet, architect, and musician who lived in the 15th century and was the Renaissance man of his day. In order to provide the familiar traditional sound of the rectangular (shoebox) European Hall, the acoustic designers set the criteria for reverberation times through the frequency spectrum and the Initial Time Delay Gap at every seat in the house to match the measurements taken at the Grosser Musik vereinssaal in Vienna and Boston Symphony Hall. In this paper we discuss the techniques used to create the traditional sound in a vineyard hall and the reaction of musicians and audiences to the completed facility. The Sala was the model for Suntory Hall in Japan which in turn spawned a number of vineyard halls in Japan. Most recently, the vineyard style seems to be appealing to more and more symphonic organizations in Europe and North America.

  13. General footage ISOLDE experimental hall

    CERN Multimedia

    2016-01-01

    Overview of the ISOLDE experimental hall. Equipment and experiments. Taken from the WITCH / EBIS platform: ISOLDE hall infrastructure, GHM line, LA1, LA2, LA0, central beamline, COLLAPS experiment, CRIS experiment, ISOLTRAP experiment, laser guidance from building 508 into the hall for laser spectroscopy COLLAPS and CRIS. Taken from the HIE ISOLDE shielding tunnel roof: ISOLDE hall infrastructure, WITCH experiment, VITO line, TAS experiment. General footage: High Tension room entrance and EBIS platform, staircases and passages in the experimental hall.

  14. Nonlocal Anomalous Hall Effect

    Science.gov (United States)

    Zhang, Steven S.-L.; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect—the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt /YIG structures.

  15. Conducting Wall Hall Thrusters

    Science.gov (United States)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  16. Nonlocal Anomalous Hall Effect.

    Science.gov (United States)

    Zhang, Steven S-L; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect-the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt/YIG structures.

  17. [University residence halls: socialization processes and drug consumption].

    Science.gov (United States)

    Laranjo, Thais Helena Mourão; Soares, Cássia Baldini

    2006-12-01

    To investigate and analyze the discourse of students living in university residence halls regarding socialization processes and drug consumption. This was qualitative research among 20 undergraduate students living in university residence halls in the city of São Paulo, Brazil, in 2003. Residence halls were taken to be socialization spaces for young people that enable the presence of low-income students at university. The interviews covered students' knowledge of the history of the residence hall, their experience of living in student residences and their perceptions regarding drug consumption. The methodological procedure that served as the basis for collection, organization and analysis of the interview data was examination of the collective discourse of the subjects. It was shown that the students had little knowledge of the history of the residence hall; solutions for problems they faced in the residence hall were sought individually; and the two main concepts observed among the people living there for preventing drug consumption were war on drugs and damage limitation. It was seen that there was a negative view regarding student residence halls that related to the constant publication of disturbing events and lack of knowledge of the importance of residence halls for enabling poor students to remain at university. In the opinion of the people living in student residence halls, such accommodation enables access to university, despite the difficulties in living together and in administration by the university. With regard to the use of drugs in the residence hall, some of the people living there emphasized the need for less tolerance towards drug consumption, while others stressed the importance of educational work, particularly among those who are just starting to live there.

  18. Hall Effect in Quasicrystals

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiang; HU Cheng-zheng; GONG Ping; WANG Ai-jun

    2005-01-01

    The relations between Hall effect and symmetry are discussed for all 2- and 3 dimensional quasicrystals with crystallographically forbidden symmetries. The results show that the numbers of independent components of the Hall coefficient (RH) are one for 3-dimensional quasicrystals, two for those 2 dimensional quasicrystals whose symmetry group is non-Abelian, and three for those 2-dimensional quasicrystals whose symmetry group is Abelian, respectively. The quasicrystals with the same number of independent components have the same form of the components of RH.

  19. Hall effect in hopping regime

    Energy Technology Data Exchange (ETDEWEB)

    Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

    2016-02-15

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

  20. Hall Effect in a Plasma.

    Science.gov (United States)

    Kunkel, W. B.

    1981-01-01

    Describes an apparatus and procedure for conducting an undergraduate laboratory experiment to quantitatively study the Hall effect in a plasma. Includes background information on the Hall effect and rationale for conducting the experiment. (JN)

  1. Laurance David Hall.

    Science.gov (United States)

    Coxon, Bruce

    2011-01-01

    An account is given of the life, scientific contributions, and passing of Laurance David Hall (1938-2009), including his early history and education at the University of Bristol, UK, and the synthesis and NMR spectroscopy of carbohydrates and other natural products during ∼20 years of research and teaching at the University of British Columbia in Vancouver, Canada. Lists of graduate students, post-doctoral fellows, and sabbatical visitors are provided for this period. Following a generous endowment by Dr. Herchel Smith, Professor Hall built a new Department of Medicinal Chemistry at Cambridge University, UK, and greatly expanded his researches into the technology and applications of magnetic resonance imaging (MRI) and zero quantum NMR. MRI technology was applied both to medical problems such as the characterization of cartilage degeneration in knee joints, the measurement of ventricular function, lipid localization in animal models of atherosclerosis, paramagnetic metal complexes of polysaccharides as contrast agents, and studies of many other anatomical features, but also to several aspects of materials analysis, including food analyses, process control, and the elucidation of such physical phenomena as the flow of liquids through porous media, defects in concrete, and the visualization of fungal damage to wood. Professor Hall's many publications, patents, lectures, and honors and awards are described, and also his successful effort to keep the Asilomar facility in Pacific Grove, California as the alternating venue for the annual Experimental NMR Conference. Two memorial services for Professor Hall are remembered.

  2. Strained graphene Hall bar

    Science.gov (United States)

    Milovanović, S. P.; Peeters, F. M.

    2017-02-01

    The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, R B, around zero-magnetic field and the occurrence of side-peaks in R B. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in R B are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads.

  3. The Inhomogeneous Hall's Ray

    OpenAIRE

    Crisp, D J; W Moran; Pollington, A. D.

    2012-01-01

    We show that the inhomogenous approximation spectrum, associated to an irrational number \\alpha\\ always has a Hall's Ray; that is, there is an \\epsilon>0 such that [0,\\epsilon) is a subset of the spectrum. In the case when \\alpha\\ has unbounded partial quotients we show that the spectrum is just a ray.

  4. Hall Sweet Home

    Science.gov (United States)

    Oguntoyinbo, Lekan

    2011-01-01

    Many urban and commuter universities have their sights set on students who are unlikely to connect with the college and likely to fail unless the right strategies are put in place to help them graduate. In efforts to improve retention rates, commuter colleges are looking to an unusual suspect: residence halls. The author discusses how these…

  5. Photon thermal Hall effect

    CERN Document Server

    Ben-Abdallah, Philippe

    2015-01-01

    A near-field thermal Hall effect (i.e.Righi-Leduc effect) in lattices of magneto-optical particles placed in a constant magnetic field is predicted. This effect is related to a symetry breaking in the system induced by the magnetic field which gives rise to preferential channels for the heat-transport by photon tunneling thanks to the particles anisotropy tuning.

  6. The Monty Hall Dilemma

    NARCIS (Netherlands)

    Barteld Kooi, [No Value

    2006-01-01

    Samenvatting: In het begin van de jaren negentig brak een wereldwijde discussie los over een probleem dat in het Engels 'The Monty Hall Dilemma' wordt genoemd. Marilyn vos Savant, die in het Guinness Book of World Records wordt genoemd als degene met het

  7. Sex partying among gay men in Sydney, Melbourne and Brisbane, Australia.

    Science.gov (United States)

    Prestage, Garrett; Down, Ian; Grulich, Andrew; Zablotska, Iryna

    2011-02-01

    Group sex is relatively common among gay men, and is a likely risk factor for infection with HIV and other sexually transmissible infections (STI). The 5,432 participants in the 2008 Gay Community Periodic Survey in Sydney, Melbourne and Brisbane, Australia, were asked about their participation in group sex. Nearly half (44.0%) of those who reported sex with casual male partners in the previous 6 months also reported engaging in group sex. Among other factors, using drugs odds ratios (OR) and confidence intervals (CI) (OR = 1.89, CI = 1.61-2.21), being HIV-positive (OR = 1.62, CI = 1.13-2.32), and engaging in anal intercourse, both with a condom (OR = 3.03, CI = 2.46-3.73) and without a condom (OR = 5.68, CI = 4.53-7.12) were independently associated with having engaged in group sex. This study suggests that gay men who engage in group sex represent an important priority for targeted HIV and STI prevention activities and research.

  8. Long-term exposure to gaseous air pollutants and cardio-respiratory mortality in Brisbane, Australia

    Directory of Open Access Journals (Sweden)

    Xiao Yu Wang

    2009-05-01

    Full Text Available This study examines the association of long-term exposure to gaseous air pollution with cardio-respiratory mortality in Brisbane, Australia, in the period 1996-2004. The pollutant concentrations were estimated using geographical information system (GIS techniques at the statistical local area (SLA level. The generalized estimating equations model was used to investigate the impact of nitrogen dioxide (NO2, ozone (O3 and sulphur dioxide (SO2 on mortality due to cardio-respiratory disease after adjusting for a range of potential confounders. An increase of 4.7% (95% confidence interval = 0.7-8.9% in cardio-respiratory mortality for 1 part per billion (ppb increment in annual average concentration of SO2 was estimated. However, there was no significant association between long-term exposures to NO2 or O3 and death due to cardio-respiratory disease. The results indicate that the annual average concentration of SO2 is associated with cardio-respiratory mortality at the SLA level and this association appears to vary with the geographical area.

  9. The Mosque and Social Networks: The Case of Muslim Youth in Brisbane

    Directory of Open Access Journals (Sweden)

    Ameera Karimshah

    2014-08-01

    Full Text Available Much of the existing public discourse surrounding Muslim youth in Western societies is framed through a simplistic and static understanding of the role of the Mosque in their everyday life. Mosques are often seen as places for the development of Muslim conservatism where membership is gender and ethno-specific and activities are socially restrictive (Spalek & Imtoual, 2007, p. 195; Spalek & Lambert, 2008; Poynting & Mason, 2008, p. 237. This contributes to an ongoing public preoccupation with the idea that it is necessary to integrate Muslim youth into “mainstream society” as a counter measure to anti-social behaviour and attributed outcomes (i.e. terrorism. This paper, building on the work of Dialmy (2007, p. 70 and Jamal (2005, p. 523, offers an account of how young Muslims network and socialise around the Mosque in Brisbane, Australia. We show that contrary to popular public conception, the role of the Mosque in the lives of Muslim youth is multifaceted and serves as the centrepiece from which the majority of socialisation, across variety formal and informal networks, occurs. This paper also explores the reasons underpinning Muslim youth’s social participation, emphasizing the socio-cultural factors (both within and beyond the place of worship that facilitate and hinder participation across a range of social settings. We argue that discussions on Muslim youth and social engagement must be positioned within an informed understanding of the nuanced role of the Mosque in the generation of social networks within Western contexts.

  10. Doing belonging: Meanings of home and settlement among the Karen Community in Brisbane, Australia

    Directory of Open Access Journals (Sweden)

    Jessica Nancy Bird

    2016-07-01

    Full Text Available The phenomenon of belonging allows diasporic people to negotiate socio-cultural terrains that go beyond singular attachments to “here” or “there”.  This paper interrogates doing belonging amongst members of the Karen refugee community from Burma settling in Brisbane, Australia.  We use data collected over twelve months of ethnographic fieldwork using the methods of participant observation and semi-structured interviews.  This paper presents an interpretation of challenges faced by Karen community members as they grapple with local and transnational complexities of belonging within their own community, whilst also establishing belonging to Australian social environments.  We argue that Karen participants’ lived experiences of settlement challenge bounded notions of belonging, thereby allowing us to extend dominant constructions of settlement and social inclusion and give way to a more nuanced representation of an emerging diasporic community.  We thus reposition a resettled refugee community away from disempowering and exclusionary notions that dominant constructions of belonging and inclusion tend to impose. Keywords: Karen, belonging, settlement, refugee, transnational

  11. The resilience of neighborhood social processes: A case study of the 2011 Brisbane flood.

    Science.gov (United States)

    Wickes, Rebecca; Britt, Chester; Broidy, Lisa

    2017-02-01

    Social disorganization theories position neighborhood social capital and collective efficacy as key social processes that should facilitate community resilience in the aftermath of disaster. Yet limited evidence demonstrates that these social processes are themselves resilient with some studies showing that disaster can fracture even once cohesive neighborhoods. In this paper we assess the stability of neighborhood level collective efficacy and social capital before and after a disaster. We use multilevel structural equation modeling and draw on census and longitudinal survey data collected from over 4000 residents living in 148 neighborhoods in Brisbane, Australia before and after a significant flood event. We examine what happens to social capital and collective efficacy in flooded and non-flooded neighborhoods and assess whether demographic shifts are associated with change and/or stability in these processes. We find strong evidence that these processes operate similarly across flooded and not flooded communities. Our findings also reveal significant stability for our measures of social capital across time, while collective efficacy increases post flood across all neighborhoods, but more so in flooded neighborhoods. Neighborhood demographics have limited effect on patterns of stability or change in these social processes. We discuss the theoretical and practical implications of these findings for our understanding of neighborhood resilience in the wake of disaster.

  12. Comparison of pollution indices for the assessment of heavy metal in Brisbane River sediment.

    Science.gov (United States)

    Duodu, Godfred Odame; Goonetilleke, Ashantha; Ayoko, Godwin A

    2016-12-01

    Estuarine environment is complex and receives different contaminants from numerous sources that are persistent, bioaccumulative and toxic. The distribution, source, contamination and ecological risk status of heavy metals in sediment of Brisbane River, Australia were investigated. Sediment samples were analysed for major and minor elements using LA-ICP-MS. Principal component analysis and cluster analysis identified three main sources of metals in the samples: marine sand intrusion, mixed lithogenic and sand intrusion as well as transport related. To overcome inherent deficiencies in using a single index, a range of sediment quality indices, including contamination factor, enrichment factor, index of geo-accumulation, modified degree of contamination, pollution index and modified pollution index were utilised to ascertain the sediment quality. Generally, the sediment is deemed to be "slightly" to "heavily" polluted. A further comparison with the Australian Sediment Quality Guidelines indicated that Ag, Cr, Cu, Ni, Pb and Zn had the potential to rarely cause biological effects while Hg could frequently cause biological effects. Application of potential ecological risk index (RI) revealed that the sediment poses moderate to considerable ecological risk. However, RI could not account for the complex sediment behaviour because it uses a simple contamination factor. Consequently, a modified ecological risk index (MRI) employing enrichment factor is proposed. This provides a more reliable understanding of whole sediment behaviour and classified the ecological risk of the sediment as moderate to very high. The results demonstrate the need for further investigation into heavy metal speciation and bioavailability in the sediment to ascertain the degree of toxicity.

  13. Crustal architecture across Phanerozoic Australia along the Eromanga-Brisbane Geoscience Transect: evolution and analogues

    Science.gov (United States)

    Finlayson, D. M.

    1993-03-01

    The crustal architecture across Phanerozoic Australia has been established from seismic data along an 1100-km-long east-west transect, the Eromanga-Brisbane Geoscience Transect. This has enabled a better understanding of deep structures and processes that have controlled the development of major sedimentary basin systems. It has shown that crustal dynamics throughout geological history have played an important role in the development of these sedimentary basins and that structures developed during the early Palaeozoic have influenced, and continue to influence, basin systems. The transect crosses three major basement provinces of the Tasman Orogenic System in eastern Australia - the Thomson, northern Lachlan, and New England Orogens. The basement geology in the transect region has, until now, been only poorly understood because it is largely obscured by the Mesozoic cover rocks of the Eromanga, Surat and Clarence-Moreton Basins. The transect interpretation has firmly identified crustal-scale ramp structures, multiple intra-crustal detachment surfaces, strike-slip fault architecture, lower-crustal magmatism/underplating, Mono remobilisation, and intra-crustal terranes in the geological reconstructions of southern Queensland. The boundaries between the orogens, the Foyleview and Burunga—Mooki Geosutures, have been identified as lithospheric-scale structures that have influenced the evolution of the Tasman Orogenic System as a whole.

  14. Plasma Relaxation in Hall Magnetohydrodynamics

    CERN Document Server

    Shivamoggi, B K

    2011-01-01

    Parker's formulation of isotopological plasma relaxation process in magnetohydrodynamics (MHD) is extended to Hall MHD. The torsion coefficient alpha in the Hall MHD Beltrami condition turns out now to be proportional to the "potential vorticity." The Hall MHD Beltrami condition becomes equivalent to the "potential vorticity" conservation equation in two-dimensional hydrodynamics if the Hall MHD Lagrange multiplier beta is taken to be proportional to the "potential vorticity" as well. The winding pattern of the magnetic field lines in Hall MHD then appears to evolve in the same way as "potential vorticity" lines in 2D hydrodynamics.

  15. Cylindrical geometry hall thruster

    Science.gov (United States)

    Raitses, Yevgeny; Fisch, Nathaniel J.

    2002-01-01

    An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.

  16. Relativistic Hall Effect

    CERN Document Server

    Bliokh, Konstantin Y

    2011-01-01

    We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.

  17. Planar Hall Effect MRAM

    OpenAIRE

    Bason, Y.; Klein, L.; Yau, J. -B.; Hong, X.; Hoffman, J.; Ahn, C. H.

    2005-01-01

    We suggest a new type of magnetic random access memory (MRAM) that is based on the phenomenon of the planar Hall effect (PHE) in magnetic films, and we demonstrate this idea with manganite films. The PHE-MRAM is structurally simpler than currently developed MRAM that is based on magnetoresistance tunnel junctions (MTJ), with the tunnel junction structure being replaced by a single layer film.

  18. Health beliefs, perceived self-efficacy, and breast self-examination among Thai migrants in Brisbane.

    Science.gov (United States)

    Jirojwong, Sansnee; MacLennan, Robert

    2003-02-01

    Women in Thailand have a relatively low risk of developing breast cancer; however, death rates from breast cancer are increasing. Rates in many migrant groups are also known to be on the increase. Little is known about breast cancer screening, particularly breast self-examination (BSE), among Thai migrant women in other countries. In Australia, non-English-speaking-background migrants are known to be low users of preventive health services. To investigate, using the health belief model (HBM) and self-efficacy as a theoretical framework, the use of BSE in a recent migrant group, Thai women in Australia, and to identify sociodemographic variables that influence the women's regular use of BSE. In 1998, a cross-sectional study was conducted among 145 Thai women in Brisbane recruited through a snowball-sampling method, which used personal contacts and key persons within the Thai community. The study was approved by the University Human Ethics Review Committee. Data were collected through designed closed-ended questions. Only 25% of the women performed BSE regularly. HBM indices were strongly associated with BSE. Beliefs in high personal susceptibility to breast cancer strongly increased the likelihood of BSE. After adjusting for potential confounding factors, cues or triggers to undertake BSE and self-efficacy, or the ability to do BSE were found to be important determinants of regular BSE. Study limitations, including data collection methods, are discussed. A low percentage of women practised BSE regularly. The HBM is a useful framework for identifying factors influencing the use of BSE. Strategies that increase the confidence of women to undertake preventive health behaviour or increase self-efficacy are likely to increase their regular screening for breast cancer.

  19. Polycyclic Aromatic Hydrocarbons in Biota from the Brisbane River Estuary, Australia

    Science.gov (United States)

    Kayal, S.; Connell, D. W.

    1995-05-01

    Six species of aquatic organisms from the Brisbane River estuarine system were sampled and their tissues analysed for polycyclic aromatic hydrocarbons (PAHs). These were the sea mullet, Mugil cephalus, bony bream, Nematolosa come, blue catfish, Arius graffei, mud crab, Scylla serrata, pelican, Pelecanus conspicillatus, and silver gull, Larus novaehollandiae. PAHs in the muscle (fish and birds) and soft (crab) tissue samples were isolated by first hydrolysing these samples and then solvent extraction followed by column chromatography. The compounds were then identified and quantified by gas chromatography and gas chromatography coupled with mass spectrometry. The samples contained low levels of PAHs that ranged in molecular weight from 128 (naphthalene) to 252 (benzo[k]fluoranthene). The highest total PAH level of 195 ng g -1, wet weight, was recorded in mullet samples whereas the blue catfish samples yielded the lowest level of 43 ng g -1. Relative ratios of low molecular weight (≤3-rings) compounds to those with high molecular weights (≤4-rings) suggested a petroleum related origin for the PAHs detected in the organisms. Results indicated that significant biomagnification of PAHs in the estuarine ecosystem sampled is highly unlikely. Characteristics such as the trophic level and size/age were not significant factors in determining the corresponding tissue PAH levels in the fish and crab species. Tissue lipid content, however, was found to be a primary factor in determining the PAH concentrations in fish species. PAH levels recorded in the samples are comparable to those levels reported from similarly urbanized areas in other geographical locations.

  20. "Hall viscosity" and intrinsic metric of incompressible fractional Hall fluids

    OpenAIRE

    Haldane, F. D. M.

    2009-01-01

    The (guiding-center) "Hall viscosity" is a fundamental tensor property of incompressible ``Hall fluids'' exhibiting the fractional quantum Hall effect; it determines the stress induced by a non-uniform electric field, and the intrinsic dipole moment on (unreconstructed) edges. It is characterized by a rational number and an intrinsic metric tensor that defines distances on an ``incompressibility lengthscale''. These properties do not require rotational invariance in the 2D plane. The sign of ...

  1. Wheel of concert hall acoustics

    OpenAIRE

    Kuusinen, A.; Lokki, T.

    2017-01-01

    More than a hundred years of research on concert hall acoustics has provided an extensive list of attributes to describe and evaluate the perceptual aspects of sound in concert halls. This brief overview discusses the current knowledge, and presents a "wheel of concert hall acoustics" in which the main aspects are gathered together with the descriptive attributes that are commonly encountered in the research literature. Peer reviewed

  2. Thermal Hall Effect of Magnons

    Science.gov (United States)

    Murakami, Shuichi; Okamoto, Akihiro

    2017-01-01

    We review recent developments in theories and experiments on the magnon Hall effect. We derive the thermal Hall conductivity of magnons in terms of the Berry curvature of magnonic bands. In addition to the Dzyaloshinskii-Moriya interaction, we show that the dipolar interaction can make the Berry curvature nonzero. We mainly discuss theoretical aspects of the magnon Hall effect and related theoretical works. Experimental progress in this field is also mentioned.

  3. Magnesium Hall Thruster

    Science.gov (United States)

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  4. Hall Effect Spintronics

    Science.gov (United States)

    2008-09-23

    in Fig. 1. An alternating current source operating at frequency f1 is attached to contacts B and D with a respective lock-in amplifier monitoring...that floats the signal and a transconductance amplifier . The input voltage of each lock-in amplifier is composed of two signals: the Hall voltage at...alternating current sources operating at frequencies f1 and f2 respectively. VAC and VDB are lock-in amplifiers set for the reference frequencies f2 and f1

  5. The Microwave Hall Effect

    OpenAIRE

    2015-01-01

    This paper describes a simple microwave apparatus to measure the Hall effect in semiconductor wafers. The advantage of this technique is that it does not require contacts on the sample or the use of a resonant cavity. Our method consists of placing the semiconductor wafer into a slot cut in an X-band (8 - 12 GHz) waveguide series tee, injecting microwave power into the two opposite arms of the tee, and measuring the microwave output at the third arm. A magnetic field applied perpendicular to ...

  6. The ISOLDE hall

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Since 1992, after its move from the 600 MeV SC, ISOLDE is a customer of the Booster (then 1 GeV, now 1.4 GeV). The intense Booster beam (some 3E13 protons per pulse) is directed onto a target, from which a mixture of isotopes emanates. After ionization and electrostatic acceleration to 60 keV, they enter one of the 2 spectrometers (General Purpose Separator: GPS, and High Resolution Separator: HRS) from which the selected ions are directed to the experiments. The photos show: the REX-ISOLDE post accelerator; the mini-ball experiment; an overview of the ISOLDE hall. In the picture (_12) of the hall, the separators are behind the wall. From either of them, beams can be directed into any of the many beamlines towards the experiments, some of which are visible in the foreground. The elevated cubicle at the left is EBIS (Electron Beam Ion Source), which acts as a charge-state multiplier for the REX facility. The ions are further mass analzyzed and passed on to the linac which accelerates them to higher energies. T...

  7. Cosmopolitanism - Conversation with Stuart Hall

    OpenAIRE

    Hall, Stuart

    2006-01-01

    Forty minute conversation between Stuart Hall and Pnina Werbner, filmed and edited by Haim Bresheeth. Synopsis by Sarah Harrison. Conversation between Stuart Hall and Pnina Werbner on the theme of Cosmopolitanism (to be shown at the Association of Social Anthropologists Silver Jubilee conference in 2006), in March 2006

  8. The virtual reconstruction of the ancient Roman concert hall in Aphrodisias, Turkey

    DEFF Research Database (Denmark)

    Rindel, Jens Holger; Gade, Anders Christian; Nielsen, Martin Lisa

    2006-01-01

    About two thousand years ago one of the world’s earliest and most beautiful concert halls were built in the city Aphrodisias, named after the goddess Aphrodite. It was a rich society, renowned for its marble and mastery in sculptures. Like many other cities in the Roman Empire there was an open......-air theatre for plays and a roofed theatre, Odeon, for concerts. In the framework of an EU-project the Odeon or concert hall has been reconstructed in a virtual environment, visually and acoustically. The capacity of the hall was around 1000 in the audience. There has been some uncertainty about the original...... with reconstructed music, has been made with the ODEON room acoustic modelling program. From January 2006 the reconstructed concert hall will be open for visitors, although in a virtual environment. The address is: http://www.at.oersted.dtu.dk/~erato....

  9. Intercomparison of Terrestrial Laser Scanning Instruments for Assessing Forested Ecosystems: A Brisbane Field Experiment

    Science.gov (United States)

    Armston, J.; Newnham, G.; Strahler, A. H.; Schaaf, C.; Danson, M.; Gaulton, R.; Zhang, Z.; Disney, M.; Sparrow, B.; Phinn, S. R.; Schaefer, M.; Burt, A.; Counter, S.; Erb, A.; Goodwin, N.; Hancock, S.; Howe, G.; Johansen, K.; Li, Z.; Lollback, G.; Martel, J.; Muir, J.; Paynter, I.; Saenz, E.; Scarth, P.; Tindall, D.; Walker, L.; Witte, C.; Woodgate, W.; Wu, S.

    2013-12-01

    During 28th July - 3rd August, 2013, an international group of researchers brought five terrestrial laser scanners (TLS) to long-term monitoring plots in three eucalyptus-dominated woodland sites near Brisbane, Queensland, Australia, to acquire scans at common locations for calibration and intercomparison.They included: DWEL - a dual-wavelength full-waveform laser scanner (Boston U., U. Massachusetts Lowell, U. Massachusetts Boston, USA) SALCA - a dual-wavelength full-waveform laser scanner (U. Salford, UK) CBL - a canopy biomass lidar, a small ultraportable low-cost multiple discrete return scanner (U. Massachusetts Boston, USA) Riegl VZ400 - a survey-grade commercial waveform scanner (Queensland Government and TERN, U. Queensland, Australia) FARO Focus 3D - a lightweight commercial phase-shift ranging laser scanner (U. Southern Queensland) Two plots were scanned at Karawatha Forest Park, a Terrestrial Ecosystem Research Network (TERN) Supersite, and one plot at D'Aguilar National Park. At each 50 x 100 m plot, a center scan point was surrounded by four scan points located 25 m away in a cross pattern allowing for 3-D reconstructions of scan sites in the form of point clouds. At several center points, multiple instrument configurations (i.e. different beam divergence, angular resolution, pulse rate) were acquired to test the impact of instrument specifications on separation of woody and non-woody materials and estimation of vegetation structure parameters. Three-dimensional Photopoint photographic panoramas were also acquired, providing reconstructions of stems in the form of point clouds using photogrammetric correlation methods. Calibrated reflectance targets were also scanned to compare instrument geometric and radiometric performance. Ancillary data included hemispherical photos, TRAC LAI/clumping measurements, spectra of leaves, bark, litter, and other target components. Wet and dry leaf weights determined water content. Planned intercomparison topics and

  10. BOOK REVIEW: The limits of boundaries. Why city-regions cannot be self-governing.

    Directory of Open Access Journals (Sweden)

    Jeremy Dawkins

    2009-05-01

    Full Text Available If it really matters how a metropolitan region is governed, should it not be obvious on the ground? To take just three NewWorld examples of metropolitan-scale city councils, Calgary, Houston and Brisbane should have a different ‘look and feel’ to that of their fragmented equivalents, not to mention greater efficiency and equity stemming from their ability to manage growth across all or most of the urban region.

  11. Hall Effect Gyrators and Circulators

    Science.gov (United States)

    Viola, Giovanni; DiVincenzo, David P.

    2014-04-01

    The electronic circulator and its close relative the gyrator are invaluable tools for noise management and signal routing in the current generation of low-temperature microwave systems for the implementation of new quantum technologies. The current implementation of these devices using the Faraday effect is satisfactory but requires a bulky structure whose physical dimension is close to the microwave wavelength employed. The Hall effect is an alternative nonreciprocal effect that can also be used to produce desired device functionality. We review earlier efforts to use an Ohmically contacted four-terminal Hall bar, explaining why this approach leads to unacceptably high device loss. We find that capacitive coupling to such a Hall conductor has much greater promise for achieving good circulator and gyrator functionality. We formulate a classical Ohm-Hall analysis for calculating the properties of such a device, and show how this classical theory simplifies remarkably in the limiting case of the Hall angle approaching 90°. In this limit, we find that either a four-terminal or a three-terminal capacitive device can give excellent circulator behavior, with device dimensions far smaller than the ac wavelength. An experiment is proposed to achieve GHz-band gyration in millimeter (and smaller) scale structures employing either semiconductor heterostructure or graphene Hall conductors. An inductively coupled scheme for realizing a Hall gyrator is also analyzed.

  12. Food Behavior In Student Residence Halls: A Setting For Health Promotion

    OpenAIRE

    Alves, Hayda Josiane; Boog,Maria Cristina Faber

    2007-01-01

    Objective: To qualitatively describe food practices of students living in a residence hall. Methods: A quantitative and qualitative study was carried out in a drawn sample of 100 university students living in a residence hall in the city of Campinas, Southeastern Brazil, in 2004. Students were interviewed using a questionnaire to collect 24-hour food recall information including open questions on shopping and intake practices. Criteria were established for the analysis of meal quality. The Ch...

  13. Topological Hall and spin Hall effects in disordered skyrmionic textures

    KAUST Repository

    Ndiaye, Papa Birame

    2017-02-24

    We carry out a thorough study of the topological Hall and topological spin Hall effects in disordered skyrmionic systems: the dimensionless (spin) Hall angles are evaluated across the energy-band structure in the multiprobe Landauer-Büttiker formalism and their link to the effective magnetic field emerging from the real-space topology of the spin texture is highlighted. We discuss these results for an optimal skyrmion size and for various sizes of the sample and find that the adiabatic approximation still holds for large skyrmions as well as for nanoskyrmions. Finally, we test the robustness of the topological signals against disorder strength and show that the topological Hall effect is highly sensitive to momentum scattering.

  14. Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. Y.; Yang, G. [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S. G., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, J. L. [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang, R. M. [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Amsellem, E.; Kohn, A. [Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Yu, G. H., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-04-13

    Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

  15. Ward Identities for Hall Transport

    CERN Document Server

    Hoyos, Carlos; Oz, Yaron

    2014-01-01

    We derive quantum field theory Ward identities based on linear area preserving and conformal transformations in 2+1 dimensions. The identities relate Hall viscosities, Hall conductivities and the angular momentum. They apply both for relativistic and non relativistic systems, at zero and at finite temperature. We consider systems with or without translation invariance, and introduce an external magnetic field and viscous drag terms. A special case of the identities yields the well known relation between the Hall conductivity and half the angular momentum density.

  16. Shifting fortunes of neighbouring cities

    NARCIS (Netherlands)

    Meijers, E.J.; Lambregts, B.W.

    2009-01-01

    Polycentricity is often conceived to be the product of “a long process of very extended decentralization from big central cities to adjacent smaller ones, old and new” (Hall and Pain, 2006: 3). Accordingly, polycentric spatial development (as a process) is usually identified with a development

  17. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

    Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.

    2010-01-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... Hall effect bridge sensors....

  18. Shared Magnetics Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the proposed Phase II program, Busek Co. will demonstrate an innovative methodology for clustering Hall thrusters into a high performance, very high power...

  19. Shared Magnetics Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the proposed Phase I program, Busek Co. will demonstrate an innovative methodology for clustering Hall thrusters into a high performance, very high power...

  20. "Hall mees" Linnateatris / Triin Sinissaar

    Index Scriptorium Estoniae

    Sinissaar, Triin

    1999-01-01

    Tallinn Linnateatri ja Raadioteatri ühislavastus "Hall mees" Gill Adamsi näidendi järgi, lavastaja Eero Spriit, osades Helene Vannari ja Väino Laes, kunstnik Kustav - Agu Püüman. Esietendus 22. okt

  1. "Hall mees" Linnateatris / Triin Sinissaar

    Index Scriptorium Estoniae

    Sinissaar, Triin

    1999-01-01

    Tallinn Linnateatri ja Raadioteatri ühislavastus "Hall mees" Gill Adamsi näidendi järgi, lavastaja Eero Spriit, osades Helene Vannari ja Väino Laes, kunstnik Kustav - Agu Püüman. Esietendus 22. okt

  2. A survey of cervical screening among refugee and non-refugee African immigrant women in Brisbane, Australia.

    Science.gov (United States)

    Anaman, Judith A; Correa-Velez, Ignacio; King, Julie

    2016-10-31

    Issue addressed: To compare the level of cervical screening uptake between refugee and non-refugee African immigrant women living in Brisbane, Australia, and examine factors associated with Pap smear testing. Methods: Cross-sectional survey with a convenience sample of 254 women aged 21-62 years from 22 African countries (144 refugees, 110 non-refugees). Chi-square tests were used to compare the demographic and health-related characteristics between refugee and non-refugee women. Bivariate and multiple logistic regression analyses were used to assess the relationship between the outcome variable (Pap smear testing) and the independent variables. Results: Two-thirds of women had used Pap smear services in Australia. Chi-square test analysis established that non-refugee women were significantly more likely to have used Pap smear services than refugee women (73.6% vs 61.8% respectively; P=0.047). Immigration status, however, was not a significant predictor of cervical screening uptake in the multiple regression analyses. The significant predictors for screening uptake in these analyses were work arrangement, parity, healthcare visit, knowledge about Pap smear and perceived susceptibility to cervical cancer. Conclusion: Most women relied on opportunistic screening after receiving invitation letters to screen or after visiting health professionals for antenatal or postnatal care. So what?: The findings suggest that organised cervical screening programs are not reaching most African immigrant women living in Brisbane. It is incumbent on the public health sector, including healthcare professionals and settlement agencies working with African communities, to develop health promotion strategies that meaningfully engage African immigrant women, including those from refugee backgrounds, to enhance their knowledge about cervical cancer and screening practices.

  3. General footage ISOLDE experimental hall HD

    CERN Multimedia

    2016-01-01

    Overview of the ISOLDE experimental hall. Equipment and experiments. Taken from the WITCH / EBIS platform: ISOLDE hall infrastructure, GHM line, LA1, LA2, LA0, central beamline, COLLAPS experiment, CRIS experiment, ISOLTRAP experiment, laser guidance from building 508 into the hall for laser spectroscopy COLLAPS and CRIS. Taken from the HIE ISOLDE shielding tunnel roof: ISOLDE hall infrastructure, WITCH experiment, VITO line, TAS experiment. General footage: High Tension room entrance and EBIS platform, staircases and passages in the experimental hall.

  4. Sheldon-Hall syndrome

    Directory of Open Access Journals (Sweden)

    Bamshad Michael J

    2009-03-01

    Full Text Available Abstract Sheldon-Hall syndrome (SHS is a rare multiple congenital contracture syndrome characterized by contractures of the distal joints of the limbs, triangular face, downslanting palpebral fissures, small mouth, and high arched palate. Epidemiological data for the prevalence of SHS are not available, but less than 100 cases have been reported in the literature. Other common clinical features of SHS include prominent nasolabial folds, high arched palate, attached earlobes, mild cervical webbing, short stature, severe camptodactyly, ulnar deviation, and vertical talus and/or talipes equinovarus. Typically, the contractures are most severe at birth and non-progressive. SHS is inherited in an autosomal dominant pattern but about half the cases are sporadic. Mutations in either MYH3, TNNI2, or TNNT3 have been found in about 50% of cases. These genes encode proteins of the contractile apparatus of fast twitch skeletal muscle fibers. The diagnosis of SHS is based on clinical criteria. Mutation analysis is useful to distinguish SHS from arthrogryposis syndromes with similar features (e.g. distal arthrogryposis 1 and Freeman-Sheldon syndrome. Prenatal diagnosis by ultrasonography is feasible at 18–24 weeks of gestation. If the family history is positive and the mutation is known in the family, prenatal molecular genetic diagnosis is possible. There is no specific therapy for SHS. However, patients benefit from early intervention with occupational and physical therapy, serial casting, and/or surgery. Life expectancy and cognitive abilities are normal.

  5. Feasibility Study of Economics and Performance of Solar Photovoltaics at the Brisbane Baylands Brownfield Site in Brisbane, California. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

    Energy Technology Data Exchange (ETDEWEB)

    Salasovich, J.; Geiger, J.; Healey, V.; Mosey, G.

    2013-04-01

    The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Brisbane Baylands site in Brisbane, California, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this report is to assess the site for a possible photovoltaic (PV) system installation and estimate the cost, performance, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.

  6. Iodine Hall Thruster

    Science.gov (United States)

    Szabo, James

    2015-01-01

    Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars. In the Phase I project, Busek Company, Inc., tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high-flow iodine feed system and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200 to 600 V was demonstrated. Testing showed that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering a slightly higher thrust-to-power (T/P) ratio. In Phase II, a complete iodine-fueled system was developed, including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW; however, it can be deeply throttled as well as clustered to much higher power levels. The technology also can be scaled to greater than 100 kW per thruster to support megawatt-class missions. The target thruster efficiency for the full-scale system is 65 percent at high specific impulse (Isp) (approximately 3,000 s) and 60 percent at high thrust (Isp approximately 2,000 s).

  7. 500 Cities: City Boundaries

    Data.gov (United States)

    U.S. Department of Health & Human Services — This city boundary shapefile was extracted from Esri Data and Maps for ArcGIS 2014 - U.S. Populated Place Areas. This shapefile can be joined to 500 Cities...

  8. Psychosocial intervention, as a contribution to local human development within Medellin’s public scope. Case study: project aps - “buenvivir” (good living into a family. sponsor: City hall of Medellin, Colombia

    Directory of Open Access Journals (Sweden)

    J. J. García

    2013-10-01

    Full Text Available This article provides information about a research held on the psychosocial intervention offered from social projects such as educational formative spaces. A critical analysis is made by means of a government project conducted by the local administration of the city of Medellin known as “APS Buenvivir en Familia, 2011”, compiled by the Social Welfare Town Council Office, in association with the Municipality’s Health Department. Its purpose was to examine the logic and approach of psychosocial intervention as an input to human development. It was carried out through a qualitative focusing, taking in consideration the following categories: The psychosocial intervention has a definite impact on local human development, psychosocial praxis from the point of view of a public action strategy, community involvement taken as a true political act. The results showed that the psychosocial as a public exercise makes a contribution to local human development starting from the social involvement of communities and, in its everyday doing, presents structural and formal contradictions between the way they are designed and how the projects are planned and implemented among the people. 

  9. Displacement ventilation in lecture halls

    OpenAIRE

    Egorov, Artem

    2013-01-01

    This thesis considers several important goals. The main purpose is to see how displacement ventilation sys-tem works in the lecture hall of M-building and compare obtained results with D2 and Indoor Climate Classi-fication. The second one is to analyze the function of the ventilation system. The last one is to realize when displacement ventilation is preferable to mixing ventilation. Analysis of the system was carried out with instruments from MUAS HVAC laboratory. In lecture hall were me...

  10. Bound values for Hall conductivity of heterogeneous medium under quantum Hall effect conditions

    Indian Academy of Sciences (India)

    V E Arkhincheev

    2008-02-01

    Bound values for Hall conductivity under quantum Hall effect (QHE) conditions in inhomogeneous medium has been studied. It is shown that bound values for Hall conductivity differ from bound values for metallic conductivity. This is due to the unusual character of current percolation under quantum Hall effect conditions.

  11. Optimization of the energy performance of shipbuilding halls in Dubai; Optimalisatie energieprestatie van scheepshallen in Dubai

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xichun; Yu, Bing [Royal Haskoning Consulting Company, Shanghai (China); Luscuere, P. [Divisie Gebouwinstallaties, Haskoning Nederland, Nijmegen (Netherlands)

    2010-03-15

    This article describes the optimization of the energy performance of three shipbuilding halls in Dubai Maritime City (DMC) in Dubai, using the simulation programs EnergyPlus, Designbuilder and WINDOW5. The energy performance of the building envelope is primarily optimized by means of external sun blinds. In simulations the energy performance of shipbuilding halls was examined while using air-cooled and water-cooled cooling units. Based on the results the designers optimized the energy performance of the shipbuilding halls. [Dutch] In dit artikel wordt de optimalisatie van de energieprestatie van drie scheepshallen in Dubai Maritime City (DMC) te Dubai beschreven, waarbij de simulatieprogramma's EnergyPlus, Designbuilder en WINDOW5 zijn gebruikt. De energieprestatie van de bouwenvelop is primair geoptimaliseerd met externe zonwering, Met simulaties is gekeken naar de energieprestatie van de scheepshallen bij toepassing van luchtgekoelde en watergekoelde koelunits. Op basis van de resultaten hebben de ontwerpers de energieprestatie van de scheepshallen geoptimaliseerd.

  12. Berry curvature and various thermal Hall effects

    Science.gov (United States)

    Zhang, Lifa

    2016-10-01

    Applying the approach of semiclassical wave packet dynamics, we study various thermal Hall effects where carriers can be electron, phonon, magnon, etc. A general formula of thermal Hall conductivity is obtained to provide an essential physics for various thermal Hall effects, where the Berry phase effect manifests naturally. All the formulas of electron thermal Hall effect, phonon Hall effect, and magnon Hall effect can be directly reproduced from the general formula. It is also found that the Strěda formula can not be directly applied to the thermal Hall effects, where only the edge magnetization contributes to the Hall effects. Furthermore, we obtain a combined formula for anomalous Hall conductivity, thermal Hall electronic conductivity and thermal Hall conductivity for electron systems, where the Berry curvature is weighted by a different function. Finally, we discuss particle magnetization and its relation to angular momentum of the carrier, change of which could induce a mechanical rotation; and possible experiments for thermal Hall effect associated with a mechanical rotation are also proposed.

  13. The Other Hall Effect: College Board Physics

    Science.gov (United States)

    Sheppard, Keith; Gunning, Amanda M.

    2013-01-01

    Edwin Herbert Hall (1855-1938), discoverer of the Hall effect, was one of the first winners of the AAPT Oersted Medal for his contributions to the teaching of physics. While Hall's role in establishing laboratory work in high schools is widely acknowledged, his position as chair of the physics section of the Committee on College Entrance…

  14. A Gift for Reading Hall No. 1

    Science.gov (United States)

    MacWilliams, Bryon

    2009-01-01

    In this article, the author describes Reading Hall No. 1 of the Russian State Library. He was placed in the first reading hall in the mid-1990s, when the Russian government still honored Soviet traditions of granting certain privileges to certain foreigners. In the first hall, the rules are different. He can request as many books as he wants. He…

  15. Ultrafine Particles from Traffic Emissions and Children’s Health (UPTECH in Brisbane, Queensland (Australia: Study Design and Implementation

    Directory of Open Access Journals (Sweden)

    Wafaa Nabil Ezz

    2015-02-01

    Full Text Available Ultrafine particles are particles that are less than 0.1 micrometres (µm in diameter. Due to their very small size they can penetrate deep into the lungs, and potentially cause more damage than larger particles. The Ultrafine Particles from Traffic Emissions and Children’s Health (UPTECH study is the first Australian epidemiological study to assess the health effects of ultrafine particles on children’s health in general and peripheral airways in particular. The study is being conducted in Brisbane, Australia. Continuous indoor and outdoor air pollution monitoring was conducted within each of the twenty five participating school campuses to measure particulate matter, including in the ultrafine size range, and gases. Respiratory health effects were evaluated by conducting the following tests on participating children at each school: spirometry, forced oscillation technique (FOT and multiple breath nitrogen washout test (MBNW (to assess airway function, fraction of exhaled nitric oxide (FeNO, to assess airway inflammation, blood cotinine levels (to assess exposure to second-hand tobacco smoke, and serum C-reactive protein (CRP levels (to measure systemic inflammation. A pilot study was conducted prior to commencing the main study to assess the feasibility and reliably of measurement of some of the clinical tests that have been proposed for the main study. Air pollutant exposure measurements were not included in the pilot study.

  16. Community perceptions on the significant extension of life: an exploratory study among urban adults in Brisbane, Australia.

    Science.gov (United States)

    Underwood, Mair; Bartlett, Helen P; Partridge, Brad; Lucke, Jayne; Hall, Wayne D

    2009-02-01

    Some researchers in the field of ageing claim that significant extension of the human lifespan will be possible in the near future. While many of these researchers have assumed that the community will welcome this technology, there has been very little research on community attitudes to life extension. This paper presents the results of an in-depth qualitative study of community attitudes to life extension across age groups and religious boundaries. There were 57 individual interviews, and 8 focus groups (totalling 72 focus group participants) conducted with community members in Brisbane, Australia. Community attitudes to life extension were more varied and complex than have been assumed by some biogerontologists and bioethicists. While some participants would welcome the opportunity to extend their lives others would not even entertain the possibility. This paper details these differences of opinion and reveals contrasting positions that reflect individualism or social concern among community members. The findings also highlight the relationship between Christianity, in particular belief in an afterlife, and attitudes to life extension technology. Overall, the study raises questions about the relationship between interest in life extension, the medicalisation of ageing and the increasing acceptability of enhancement technologies that need to be addressed in more representative samples of the community.

  17. Cleaner in Hall of Residence

    Science.gov (United States)

    Hotel and Catering Industry Training Board, Wembley (England).

    This syllabus is intended for the use of training personnel in drawing up training programs for cleaners in halls of residence. Its main objective is to produce fully trained cleaners, thereby maintaining and raising standards. The syllabus is divided into three sections: Introduction to Housekeeping Employees, and Tasks Performed by the Majority…

  18. Hall / Madle Mühlbach

    Index Scriptorium Estoniae

    Mühlbach, Madle

    2008-01-01

    Hallist värvusest interjööris, olles oma passiivsuses ja lakoonilisuses nii efektne, kui seda ilmestab mõni värvikam detail või neutraalne tasakaalustaja. Lk. 73 Eva Toome valitud halle esemeid müügivõrgust

  19. ATLAS Assembly Hall Open Day

    CERN Document Server

    Patrice Loiez

    2004-01-01

    To mark the 50th Anniversary of the founding of CERN, a day of tours, displays and presentations was held in October 2004. The assembly halls for the experiments that were waiting to be installed on the LHC, such as ATLAS shown here, were transformed into display areas and cafés.

  20. Breastfeeding beliefs and practices of African women living in Brisbane and Perth, Australia.

    Science.gov (United States)

    Gallegos, Danielle; Vicca, Natalie; Streiner, Samantha

    2015-10-01

    The purpose of this study was to explore the experience of breastfeeding among refugee women from Liberia, Sierra Leone, Burundi and the Democratic Republic of Congo living in two major capital cities in Australia. Participants were recruited from their relevant community associations and via a snowballing technique. Thirty-one women took part in either individual interviews or facilitated group discussions to explore their experiences of breastfeeding in their home country and in Australia. Thematic analysis revealed four main themes: cultural breastfeeding beliefs and practices; stigma and shame around breastfeeding in public; ambivalence towards breastfeeding and breastfeeding support. Women who originated from these four African countries highlighted a significant desire for breastfeeding and an understanding that it was the best method for feeding their infants. Their breastfeeding practices in Australia were a combination of practices maintained from their countries of origin and those adopted according to Australian cultural norms. They exemplified the complexity of breastfeeding behaviour and the relationship between infant feeding with economic status and the perceived social norms of the host country. The results illustrate the need for policy makers and health professionals to take into consideration the environmental, social and cultural contexts of the women who are purportedly targeted for the promotion of breastfeeding. © 2013 John Wiley & Sons, Ltd.

  1. Aasta betoonehitis on Tondiraba jäähall / Silvia Pärmann

    Index Scriptorium Estoniae

    Pärmann, Silvia

    2015-01-01

    Konkursi "Aasta betoonehitis 2014" võidutööks valiti Kadarik Tüür Arhitektide loodud Tondiraba jäähall. Eriauhinnad pälvisid arhitektuuribüroo Studio-3 Eesti saatkonnahoone eest Pekingis, Novarc Group AS ja Ilmar Klammer parkimismaja eest Ülemiste Citys, Lauri Tuulberg korteri eest Tallinnas Kosemetsa teel

  2. Planar Hall effect bridge magnetic field sensors

    Science.gov (United States)

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  3. Fresh air for an event hall. Power/heat/cold generation; Gute Luft fuer Veranstaltungshalle. Kraft-Waerme-Kaelte-Kopplung

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Wolfgang

    2009-02-15

    Many towns would be able to offer an attractive congress and cultural programme if the room climate in their event halls would be more comfortable. The city of Wunsidel modernized the space HVAC system of its event hall (''Fichtelgebirgshalle'') and installed a new cooling system. The operator had already used cogeneration systems with satisfactory results, so the existing cogeneration system was expanded and a refrigerating absorber was installed additionally. With the better room climate, the hall was booked for more events than ever before. (orig.)

  4. Optical Hall effect-model description: tutorial.

    Science.gov (United States)

    Schubert, Mathias; Kühne, Philipp; Darakchieva, Vanya; Hofmann, Tino

    2016-08-01

    The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors. Among many advantages, while the optical Hall effect dispenses with the need of electrical contacts, electrical material properties such as effective mass and mobility parameters, including their anisotropy as well as carrier type and density, can be determined from the optical Hall effect. Measurement of the optical Hall effect can be performed within the concept of generalized ellipsometry at an oblique angle of incidence. In this paper, we review and discuss physical model equations, which can be used to calculate the optical Hall effect in single- and multiple-layered structures of semiconductor materials. We define the optical Hall effect dielectric function tensor, demonstrate diagonalization approaches, and show requirements for the optical Hall effect tensor from energy conservation. We discuss both continuum and quantum approaches, and we provide a brief description of the generalized ellipsometry concept, the Mueller matrix calculus, and a 4×4 matrix algebra to calculate data accessible by experiment. In a follow-up paper, we will discuss strategies and approaches for experimental data acquisition and analysis.

  5. Electron dynamics in Hall thruster

    Science.gov (United States)

    Marini, Samuel; Pakter, Renato

    2015-11-01

    Hall thrusters are plasma engines those use an electromagnetic fields combination to confine electrons, generate and accelerate ions. Widely used by aerospace industries those thrusters stand out for its simple geometry, high specific impulse and low demand for electric power. Propulsion generated by those systems is due to acceleration of ions produced in an acceleration channel. The ions are generated by collision of electrons with propellant gas atoms. In this context, we can realize how important is characterizing the electronic dynamics. Using Hamiltonian formalism, we derive the electron motion equation in a simplified electromagnetic fields configuration observed in hall thrusters. We found conditions those must be satisfied by electromagnetic fields to have electronic confinement in acceleration channel. We present configurations of electromagnetic fields those maximize propellant gas ionization and thus make propulsion more efficient. This work was supported by CNPq.

  6. Symmetric functions and Hall polynomials

    CERN Document Server

    MacDonald, Ian Grant

    1998-01-01

    This reissued classic text is the acclaimed second edition of Professor Ian Macdonald's groundbreaking monograph on symmetric functions and Hall polynomials. The first edition was published in 1979, before being significantly expanded into the present edition in 1995. This text is widely regarded as the best source of information on Hall polynomials and what have come to be known as Macdonald polynomials, central to a number of key developments in mathematics and mathematical physics in the 21st century Macdonald polynomials gave rise to the subject of double affine Hecke algebras (or Cherednik algebras) important in representation theory. String theorists use Macdonald polynomials to attack the so-called AGT conjectures. Macdonald polynomials have been recently used to construct knot invariants. They are also a central tool for a theory of integrable stochastic models that have found a number of applications in probability, such as random matrices, directed polymers in random media, driven lattice gases, and...

  7. Spin Hall effect by surface roughness

    KAUST Repository

    Zhou, Lingjun

    2015-01-08

    The spin Hall and its inverse effects, driven by the spin orbit interaction, provide an interconversion mechanism between spin and charge currents. Since the spin Hall effect generates and manipulates spin current electrically, to achieve a large effect is becoming an important topic in both academia and industries. So far, materials with heavy elements carrying a strong spin orbit interaction, provide the only option. We propose here a new mechanism, using the surface roughness in ultrathin films, to enhance the spin Hall effect without heavy elements. Our analysis based on Cu and Al thin films suggests that surface roughness is capable of driving a spin Hall angle that is comparable to that in bulk Au. We also demonstrate that the spin Hall effect induced by surface roughness subscribes only to the side-jump contribution but not the skew scattering. The paradigm proposed in this paper provides the second, not if only, alternative to generate a sizable spin Hall effect.

  8. Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu

    2015-09-16

    We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.

  9. Low-Voltage Hall Thruster Mode Transitions

    Science.gov (United States)

    2014-06-01

    Technical Paper 3. DATES COVERED (From - To) June 2014- July 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER In-House Low-Voltage Hall Thruster Mode...ABSTRACT Past investigations of the 6kW-class H6 Hall thruster during low-voltage operation revealed two operating modes, corresponding to the...topologies were characterized for the H6 Hall thruster from 100V to 200V discharge, with variation in cathode flow fraction, cathode position inside and

  10. Listening to the acoustics in concert halls

    Science.gov (United States)

    Beranek, Leo L.; Griesinger, David

    2004-05-01

    How does acoustics affect the symphonic music performed in a concert hall? The lecture begins with an illustrated discussion of the architectural features that influence the acoustics. Boston Symphony Hall, which was built in 1900 when only one facet of architectural design was known, now rates as one of the world's great halls. How this occurred will be presented. Music is composed with some acoustical environment in mind and this varies with time from the Baroque to the Romantic to the Modern musical period. Conductors vary their interpretation according to the hall they are in. Well-traveled listeners and music critics have favorite halls. The lecture then presents a list of 58 halls rank ordered according to their acoustical quality based on interviews of music critics and conductors. Modern acoustical measurements made in these halls are compared with their rankings. Music recordings will be presented that demonstrate how halls sound that have different measured acoustical parameters. Photographs of a number of recently built halls are shown as examples of how these known acoustical factors have been incorporated into architectural design.

  11. Hall probes: physics and application to magnetometry

    CERN Document Server

    Sanfilippo, S

    2010-01-01

    This lecture aims to present an overview of the properties of Hall effect devices. Descriptions of the Hall phenomenon, a review of the Hall effect device characteristics and of the various types of probes are presented. Particular attention is paid to the recent development of three-axis sensors and the related techniques to cancel the offsets and the planar Hall effect. The lecture introduces the delicate problem of the calibration of a three-dimensional sensor and ends with a section devoted to magnetic measurements in conventional beam line magnets and undulators.

  12. DEVELOPMENT OF IMPROVED HALL EFFECT SENSORS.

    Science.gov (United States)

    HALL EFFECT , MAGNETOMETERS, GAIN, SENSITIVITY, MAGNETIC FIELDS, DETECTION, ELECTROMAGNETIC PROBES, WEIGHT, VOLUME, BATTERY COMPONENTS, INDIUM ALLOYS, ANTIMONY ALLOYS, FERRITES, MANPORTABLE EQUIPMENT.

  13. AN A. C. HALL EFFECT GAUSSMETER,

    Science.gov (United States)

    MEASURING INSTRUMENTS, MEASURING INSTRUMENTS, HALL EFFECT , MAGNETOMETERS, MEASUREMENT, GENERATORS, CIRCUITS, ALTERNATING CURRENT, GERMANIUM, SEMICONDUCTOR DIODES, GALVANOMETERS, VOLTAGE, DIRECT CURRENT, MAGNETIC FIELDS.

  14. Lectures on the Quantum Hall Effect

    CERN Document Server

    Tong, David

    2016-01-01

    The purpose of these lectures is to describe the basic theoretical structures underlying the rich and beautiful physics of the quantum Hall effect. The focus is on the interplay between microscopic wavefunctions, long-distance effective Chern-Simons theories, and the modes which live on the boundary. The notes are aimed at graduate students in any discipline where $\\hbar=1$. A working knowledge of quantum field theory is assumed. Contents: 1. The Basics (Landau levels and Berry phase). 2. The Integer Quantum Hall Effect. 3. The Fractional Quantum Hall Effect. 4. Non-Abelian Quantum Hall States. 5. Chern-Simons Theories. 6. Edge Modes.

  15. Anomalous Hall effect in polycrystalline Ni films

    KAUST Repository

    Guo, Zaibing

    2012-02-01

    We systematically studied the anomalous Hall effect in a series of polycrystalline Ni films with thickness ranging from 4 to 200 nm. It is found that both the longitudinal and anomalous Hall resistivity increased greatly as film thickness decreased. This enhancement should be related to the surface scattering. In the ultrathin films (46 nm thick), weak localization corrections to anomalous Hall conductivity were studied. The granular model, taking into account the dominated intergranular tunneling, has been employed to explain this phenomenon, which can explain the weak dependence of anomalous Hall resistivity on longitudinal resistivity as well. © 2011 Elsevier Ltd. All rights reserved.

  16. Automated Micro Hall Effect measurements

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Henrichsen, Henrik Hartmann; Lin, Rong

    2014-01-01

    With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods for characteriza......With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods...... for characterization and monitoring of sheet resistance as well as sheet carrier density and mobility via the Micro Hall Effect (MHE) method....

  17. Temperature Gradient in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    D. Staack; Y. Raitses; N.J. Fisch

    2003-11-24

    Plasma potentials and electron temperatures were deduced from emissive and cold floating probe measurements in a 2 kW Hall thruster, operated in the discharge voltage range of 200-400 V. An almost linear dependence of the electron temperature on the plasma potential was observed in the acceleration region of the thruster both inside and outside the thruster. This result calls into question whether secondary electron emission from the ceramic channel walls plays a significant role in electron energy balance. The proportionality factor between the axial electron temperature gradient and the electric field is significantly smaller than might be expected by models employing Ohmic heating of electrons.

  18. 76 FR 55157 - Public Meeting in Midwest City, OK, for the Proposed Keystone XL Project; Correction

    Science.gov (United States)

    2011-09-06

    ...). The referenced notice is corrected as to the meeting times: Friday, September 30, 2011. Reed Center Exhibition Hall, 5800 Will Rogers Road, Midwest City, Oklahoma 73110, 4:30-10 p.m. FOR FURTHER INFORMATION...

  19. A Holographic Quantum Hall Ferromagnet

    CERN Document Server

    Kristjansen, C; Semenoff, G W

    2013-01-01

    A detailed numerical study of a recent proposal for exotic states of the D3-probe D5 brane system with charge density and an external magnetic field is presented. The state has a large number of coincident D5 branes blowing up to a D7 brane in the presence of the worldvolume electric and magnetic fields which are necessary to construct the holographic state. Numerical solutions have shown that these states can compete with the the previously known chiral symmetry breaking and maximally symmetric phases of the D3-D5 system. Moreover, at integer filling fractions, they are incompressible with integer quantized Hall conductivities. In the dual superconformal defect field theory, these solutions correspond to states which break the chiral and global flavor symmetries spontaneously. The region of the temperature-density plane where the D7 brane has lower energy than the other known D5 brane solutions is identified. A hypothesis for the structure of states with filling fraction and Hall conductivity greater than on...

  20. Infrared Hall Conductivity in Graphene

    Science.gov (United States)

    Ellis, C. T.; Kim, M.-H.; Wu, T.; Sambandamurthy, G.; Cerne, J.; Lee, V.; Banerjee, S.

    2009-03-01

    Among the many different techniques which have revealed graphene's remarkable properties, infrared conductivity (σxx) (Jiang, PRL 2007) and the DC Hall effect (Novoselov, Nature 2005; Zhang, Nature 2005; Zhang, PRL 2006) have provided new insights into this material. In our study we determine the infrared Hall conductivity (σxy) for graphene in the 120-1000 meV range at temperatures down to 7K and magnetic fields up to 7T using Faraday measurements. Unlike σxx, which measures the sum of the optical responses for left and right circularly polarized light, σxy measures the difference and therefore is sensitive to small changes in symmetry. We compare graphene samples that are prepared using several methods, including cleaving from parent materials such as highly ordered pyrolytic graphite, as well as sonication-assisted solution-phase exfoliation of natural flake graphite powder. The films are then deposited onto Si/SiO2 substrates for infrared measurements. This work is supported by the NSF-CAREER-DMR0449899, also GS and SB thank the UB-IRDF for financial support.

  1. Effect of broadcast baiting on abundance patterns of red imported fire ants (Hymenoptera: Formicidae) and key local ant genera at long-term monitoring sites in Brisbane, Australia.

    Science.gov (United States)

    McNaught, Melinda K; Wylie, F Ross; Harris, Evan J; Alston, Clair L; Burwell, Chris J; Jennings, Craig

    2014-08-01

    In 2001, the red imported fire ant (Solenopsis invicta Buren) was identified in Brisbane, Australia. An eradication program involving broadcast bait treatment with two insect growth regulators and a metabolic inhibitor began in September of that year and is currently ongoing. To gauge the impacts of these treatments on local ant populations, we examined long-term monitoring data and quantified abundance patterns of S. invicta and common local ant genera using a linear mixed-effects model. For S. invicta, presence in pitfalls reduced over time to zero on every site. Significantly higher numbers of S. invicta workers were collected on high-density polygyne sites, which took longer to disinfest compared with monogyne and low-density polygyne sites. For local ants, nine genus groups of the 10 most common genera analyzed either increased in abundance or showed no significant trend. Five of these genus groups were significantly less abundant at the start of monitoring on high-density polygyne sites compared with monogyne and low-density polygyne sites. The genus Pheidole significantly reduced in abundance over time, suggesting that it was affected by treatment efforts. These results demonstrate that the treatment regime used at the time successfully removed S. invicta from these sites in Brisbane, and that most local ant genera were not seriously impacted by the treatment. These results have important implications for current and future prophylactic treatment efforts, and suggest that native ants remain in treated areas to provide some biological resistance to S. invicta.

  2. Immune Analysis of Brisbane and California H1N1 in Human Sera and the MIMIC System, and Correlating a H1N1 Pandemic Influenza Clinical Trial with a Clinical Trial in a Test Tube

    Science.gov (United States)

    2013-02-15

    Cal. Brisbane Wisc . Brisbane Wisc adult 0.86 0.87 0.98 0.98 0.94 0.57 0.99 0.69 elderly 0.94 0.96 0.83 0.84 0.63 0.92 1.00 0.97 24 MIMIC® samples...culture (Figure 29). This result Tr yp an b lu e n eg at iv e ce lls ( % r ec o ve re d ) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 3ng 500ng 166ng

  3. Library rooms or Library halls

    Directory of Open Access Journals (Sweden)

    Alfredo Serrai

    2013-12-01

    Full Text Available Library Halls, understood as Renaissance and Baroque architectural creations, along with the furnishings and decorations, accomplish a cognitive task and serve to transmit knowledge. The design of these spaces based on the idea that they should reflect the merits and content of the collections housed within them, in order to prepare the mind of the reader to respect and admire the volumes. In accordance with this principle, in the fifteenth century library rooms had a basilican shape, with two or three naves, like churches, reflecting thus the spiritual value of the books contained there. Next to that inspiring function, library rooms had also the task of representing the entire logical and conceptual universe of human knowledge in a figurative way, including for this purpose also the and Kunst- und Wunderkammern, namely the collections of natural, artficial objects, and works of art. The importance of library rooms and their function was understood already in the early decades of the seventeenth century, as underlined in the treatise, Musei sive Bibliothecae tam privatae quam publicae Extructio, Instructio, Cura, Usus, written by the Jesuit Claude Clément and published in 1635. Almost the entire volume is dedicated to the decoration and ornamentation of the Saloni, and the function of the library is identified exclusively with the preservation and decoration of the collection, neglecting more specifically bibliographic aspects or those connected to library science. The architectural structure of the Saloni was destined to change in relation to two factors, namely the form of books, and the sources of light. As a consequence, from the end of the sixteenth century – or perhaps even before if one considers the fragments of the Library of Urbino belonging to Federico da Montefeltro – shelves and cabinets have been placed no longer in the center of the room, but were set against the walls. This new disposition of the furniture, surmounted by

  4. Training Top 10 Hall of Fame

    Science.gov (United States)

    Training, 2012

    2012-01-01

    Microsoft Corporation and SCC Soft Computer are the newest inductees into the Training Top 10 Hall of Fame, joining the ranks of the 11 companies named to the hall since its inception in 2008 (Wyeth Pharmaceuticals subsequently was acquired by Pfizer Inc. in 2009). These 11 companies held Top 10 spots in the Training Top 50, Top 100, and now Top…

  5. 20th Annual Residence Hall Construction Report

    Science.gov (United States)

    Agron, Joe

    2009-01-01

    Even in difficult economic times, colleges and universities continue to invest in residence hall construction projects as a way to attract new students and keep existing ones on campus. According to data from "American School & University"'s 20th annual Residence Hall Construction Report, the median new project completed in 2008 was…

  6. 19th Annual Residence Hall Construction Report

    Science.gov (United States)

    Agron, Joe

    2008-01-01

    The construction of residence hall facilities at colleges and universities continues to be strong, as institutions scramble to meet the housing needs and varied demands of a growing student population. This article presents data collected from 39 new residence hall projects completed in 2007. According to American School & University's 19th…

  7. Hall effect accompanying a static skin effect

    Energy Technology Data Exchange (ETDEWEB)

    Volkenshtein, N.V.; Marchenkov, V.V.; Startsev, V.E.; Cherepanov, A.N.; Glin' skii, M.

    1985-05-10

    The Hall effect and the magnetoresistance of tungsten single crystals with rho/sub 293K//rho/sub 4.2K/ = 80 000 have been measured at 4.2 K in magnetic fields up to 150 kOe. The results reveal that a static skin effect gives rise to an anomalously pronounced increase in the Hall coefficient.

  8. Acoustical parameters in concert hall acoustics

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; ZHOU Qijun

    2003-01-01

    Professor Beranek talked about the sound qualities of concert hall. The 58 famousconcert halls in the world were graded according to the subjective comparison from the profes-sional musicians and music lovers. Six measurable objective parameters were proposed. Theranking according to these parameters were presented.

  9. The Scientific Humanism of G. Stanley Hall

    Science.gov (United States)

    Meyer, Donald H.

    1971-01-01

    This paper presents the humanistic psychology of the pioneer American psychologist Granville Stanley Hall (1844-1924), examining Hall's effort to develop a system of psychology that is at once rigorously scientific and, simultaneously, capable of verifying essential human values. (Author)

  10. Evolution of water recycling in Australian cities since 2003.

    Science.gov (United States)

    Radcliffe, J C

    2010-01-01

    The prolonged Australian drought which commenced in 2002, and the agreement between Australia's Commonwealth and States/Territories governments to progress water reform through the National Water Initiative, has resulted in many new recycling projects in Australia's capital cities. Dual reticulation systems are being advanced in new subdivision developments in Sydney, Melbourne and Adelaide. Brisbane has installed three large Advanced Water Treatment Plants that are designed to send indirect potable recycled water to the Wivenhoe Dam which is Brisbane's principal water reservoir. Numerous water recycling projects are serving industry and agriculture. Experimental managed aquifer recharge is being undertaken with wetland-treated stormwater in Adelaide and reverse osmosis treated wastewater in Perth. New National Water Quality Management Strategy recycled water guidelines have been developed for managing environmental risks, for augmentation of drinking water supplies, for managed aquifer recharge and for stormwater harvesting and reuse. Many recent investments are part-supported through Commonwealth government grants. Desalination plants are being established in Melbourne and Adelaide and a second one in Perth in addition to the newly-operational plants in Perth, South-East Queensland and Sydney. Despite there being numerous examples of unplanned indirect potable recycling, most governments remain reluctant about moving towards planned potable recycling. There is evidence of some policy bans still being maintained by governments but the National Water Commission continues to reinforce the necessity of an even-handed objective consideration of all water supply options.

  11. Star Formation and the Hall Effect

    CERN Document Server

    Braiding, Catherine

    2011-01-01

    Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the intermediate densities and field strengths encountered during the gravitational collapse of molecular cloud cores into protostars, and yet its role in the star formation process is not well-studied. This thesis describes a semianalytic self-similar model of the collapse of rotating isothermal molecular cloud cores with both Hall and ambipolar diffusion, presenting similarity solutions that demonstrate that the Hall effect has a profound influence on the dynamics of collapse. ... Hall diffusion also determines the strength of the magnetic diffusion and centrifugal shocks that bound the pseudo and rotationally-supported discs, and can introduce subshocks that further slow accretion onto the protostar. In cores that are not initially rotating Hall diffusion can even induce rotation, whic...

  12. Image city

    DEFF Research Database (Denmark)

    2003-01-01

    Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities.......Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities....

  13. Stuart Hall: An Organic Intellectual

    Directory of Open Access Journals (Sweden)

    Johanna Fernández Castro

    2017-01-01

    Full Text Available Stuart Hall (3 February 1932 – 10 February 2014 is acknowledged as one of the founding figures of British Cultural Studies. His extensive academic work on topics such as race, ethnicity and identity reflects his own position as a diasporic intellectual. His contribution to the study of popular culture is determined by the importance of his political character in every social act, his non-deterministic view of Marxism, and is especially determined by his insistence on playing an active role beyond academia in order to contribute to the transformation of hegemonic structures. The following biography aims to give a focused view of his personal history and its direct influence on his key theoretical reflections.

  14. Optical Hall effect in strained graphene

    Science.gov (United States)

    Nguyen, V. Hung; Lherbier, A.; Charlier, J.-C.

    2017-06-01

    When passing an optical medium in the presence of a magnetic field, the polarization of light can be rotated either when reflected at the surface (Kerr effect) or when transmitted through the material (Faraday rotation). This phenomenon is a direct consequence of the optical Hall effect arising from the light-charge carrier interaction in solid state systems subjected to an external magnetic field, in analogy with the conventional Hall effect. The optical Hall effect has been explored in many thin films and also more recently in 2D layered materials. Here, an alternative approach based on strain engineering is proposed to achieve an optical Hall conductivity in graphene without magnetic field. Indeed, strain induces lattice symmetry breaking and hence can result in a finite optical Hall conductivity. First-principles calculations also predict this strain-induced optical Hall effect in other 2D materials. Combining with the possibility of tuning the light energy and polarization, the strain amplitude and direction, and the nature of the optical medium, large ranges of positive and negative optical Hall conductivities are predicted, thus opening the way to use these atomistic thin materials in novel specific opto-electro-mechanical devices.

  15. The quantum Hall effects: Philosophical approach

    Science.gov (United States)

    Lederer, P.

    2015-05-01

    The Quantum Hall Effects offer a rich variety of theoretical and experimental advances. They provide interesting insights on such topics as gauge invariance, strong interactions in Condensed Matter physics, emergence of new paradigms. This paper focuses on some related philosophical questions. Various brands of positivism or agnosticism are confronted with the physics of the Quantum Hall Effects. Hacking's views on Scientific Realism, Chalmers' on Non-Figurative Realism are discussed. It is argued that the difficulties with those versions of realism may be resolved within a dialectical materialist approach. The latter is argued to provide a rational approach to the phenomena, theory and ontology of the Quantum Hall Effects.

  16. Quantum Hall Effect in Higher Dimensions

    CERN Document Server

    Karabali, Dimitra; Karabali, Dimitra

    2002-01-01

    Following recent work on the quantum Hall effect on $S^4$, we solve the Landau problem on the complex projective spaces ${\\bf C}P^k$ and discuss quantum Hall states for such spaces. Unlike the case of $S^4$, a finite spatial density can be obtained with a finite number of internal states for each particle. We treat the case of ${\\bf C}P^2$ in some detail considering both Abelian and nonabelian background fields. The wavefunctions are obtained and incompressibility of the Hall states is shown. The case of ${\\bf C}P^3$ is related to the case of $S^4$.

  17. Joule heating in spin Hall geometry

    Science.gov (United States)

    Taniguchi, Tomohiro

    2016-07-01

    The theoretical formula for the entropy production rate in the presence of spin current is derived using the spin-dependent transport equation and thermodynamics. This theory is applicable regardless of the source of the spin current, for example, an electric field, a temperature gradient, or the Hall effect. It reproduces the result in a previous work on the dissipation formula when the relaxation time approximation is applied to the spin relaxation rate. By using the developed theory, it is found that the dissipation in the spin Hall geometry has a contribution proportional to the square of the spin Hall angle.

  18. Piezo Voltage Controlled Planar Hall Effect Devices

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  19. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  20. An urban informatics approach to smart city learning in architecture and urban design education

    Directory of Open Access Journals (Sweden)

    Mirko Guaralda

    2013-08-01

    Full Text Available This study aims to redefine spaces of learning to places of learning through the direct engagement of local communities as a way to examine and learn from real world issues in the city. This paper exemplifies Smart City Learning, where the key goal is to promote the generation and exchange of urban design ideas for the future development of South Bank, in Brisbane, Australia, informing the creation of new design policies responding to the needs of local citizens. Specific to this project was the implementation of urban informatics techniques and approaches to promote innovative engagement strategies. Architecture and Urban Design students were encouraged to review and appropriate real-time, ubiquitous technology, social media, and mobile devices that were used by urban residents to augment and mediate the physical and digital layers of urban infrastructures. Our study’s experience found that urban informatics provide an innovative opportunity to enrich students’ place of learning within the city.

  1. The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Tinh, Bui Duc, E-mail: tinhbd@hnue.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Hoc, Nguyen Quang; Thu, Le Minh [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)

    2016-02-15

    Highlights: • The time-dependent Ginzburg–Landau was used to calculate fluctuation Hall conductivity and Hall angle in type-II superconductor in 2D and 3D. • We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. • The results were compared to the experimental data on YBCO. - Abstract: The fluctuation Hall conductivity and the Hall angle, describing the Hall effect, are calculated for arbitrary value of the imaginary part of the relaxation time in the frame of the time-dependent Ginzburg–Landau theory in type II-superconductor with thermal noise describing strong thermal fluctuations. The self-consistent Gaussian approximation is used to treat the nonlinear interaction term in dynamics. We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. The results are compared with experimental data on high-T{sub c} superconductor.

  2. Light Metal Propellant Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to develop light metal Hall Effect thrusters that will help reduce the travel time, mass, and cost of SMD spacecraft. Busek has identified three...

  3. Success of Hall technique crowns questioned.

    Science.gov (United States)

    Nainar, S M Hashim

    2012-01-01

    Hall technique is a method of providing stainless steel crowns for primary molars without tooth preparation and requires no local anesthesia. Literature review showed inconclusive evidence and therefore this technique should not be used in clinical practice.

  4. Dual Mode Low Power Hall Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sample and return missions desire and missions like Saturn Observer require a low power Hall thruster that can operate at high thrust to power as well as high...

  5. Iodine Hall Thruster for Space Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to develop a high power (high thrust) electric propulsion system featuring an iodine fueled Hall Effect Thruster (HET). The system to be...

  6. The phonon Hall effect: theory and application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lifa; Wang Jiansheng; Li Baowen [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Ren Jie [NUS Graduate School for Integrative Sciences and Engineering, Singapore 117456 (Singapore)

    2011-08-03

    We present a systematic theory of the phonon Hall effect in a ballistic crystal lattice system, and apply it on the kagome lattice which is ubiquitous in various real materials. By proposing a proper second quantization for the non-Hermitian in the polarization-vector space, we obtain a new heat current density operator with two separate contributions: the normal velocity responsible for the longitudinal phonon transport, and the anomalous velocity manifesting itself as the Hall effect of transverse phonon transport. As exemplified in kagome lattices, our theory predicts that the direction of Hall conductivity at low magnetic field can be reversed by tuning the temperatures, which we hope can be verified by experiments in the future. Three phonon-Hall-conductivity singularities induced by phonon-band-topology change are discovered as well, which correspond to the degeneracies at three different symmetric center points, {Gamma}, K, X, in the wavevector space of the kagome lattice.

  7. Students halls – humane lifestyle for students

    Directory of Open Access Journals (Sweden)

    Igor Seljak

    2000-01-01

    Full Text Available With the increasing number of students at the University of Ljubljana (Slovenia, the shortage of student’s accommodation in student’s halls has increased. Alongside the necessity for building new accommodation capacities an opportunity has emerged for the enforcement of new living standards that should replace outdated guidelines from the sixties. During the preparation of the project we analysed all the important elements of students accommodation in students halls. Analyses of the present conditions in existing halls were performed, including positive and negative elements. We also conducted a comparative research of student’s halls in various European countries. In conclusion a list of recommendations with real guidelines was prepared that could be used by investors when proposing new development of such buildings, as well as architects and planners.

  8. Athletics hall, Odenwald school, Heppenheim, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, M. [Trans Solar GmbH, Stuttgart (Germany)

    1999-07-01

    This building, completed in 1995, is a good example of how to use a glazed foyer, not only as a climatic buffer zone, but also for preheating the inlet air by solar gains. The completely glazed west-oriented foyer is used as a huge air collector to preheat ventilation air during the heating period. The glass superstructure across the hall stores a movable curtain, serves as a skylight and enhances the natural ventilation of the hall due to the chimney effect. The stiffening ribs of the floor are also used as an air duct to the hall and as an installation duct. Photovoltaic-powered fans are used to move solar preheated air into the hall. (author)

  9. Quantum Hall effect in momentum space

    Science.gov (United States)

    Ozawa, Tomoki; Price, Hannah M.; Carusotto, Iacopo

    2016-05-01

    We theoretically discuss a momentum-space analog of the quantum Hall effect, which could be observed in topologically nontrivial lattice models subject to an external harmonic trapping potential. In our proposal, the Niu-Thouless-Wu formulation of the quantum Hall effect on a torus is realized in the toroidally shaped Brillouin zone. In this analogy, the position of the trap center in real space controls the magnetic fluxes that are inserted through the holes of the torus in momentum space. We illustrate the momentum-space quantum Hall effect with the noninteracting trapped Harper-Hofstadter model, for which we numerically demonstrate how this effect manifests itself in experimental observables. Extension to the interacting trapped Harper-Hofstadter model is also briefly considered. We finally discuss possible experimental platforms where our proposal for the momentum-space quantum Hall effect could be realized.

  10. Multiscale Modeling of Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New multiscale modeling capability for analyzing advanced Hall thrusters is proposed. This technology offers NASA the ability to reduce development effort of new...

  11. Observation of the magnon Hall effect.

    Science.gov (United States)

    Onose, Y; Ideue, T; Katsura, H; Shiomi, Y; Nagaosa, N; Tokura, Y

    2010-07-16

    The Hall effect usually occurs in conductors when the Lorentz force acts on a charge current in the presence of a perpendicular magnetic field. Neutral quasi-particles such as phonons and spins can, however, carry heat current and potentially exhibit the thermal Hall effect without resorting to the Lorentz force. We report experimental evidence for the anomalous thermal Hall effect caused by spin excitations (magnons) in an insulating ferromagnet with a pyrochlore lattice structure. Our theoretical analysis indicates that the propagation of the spin waves is influenced by the Dzyaloshinskii-Moriya spin-orbit interaction, which plays the role of the vector potential, much as in the intrinsic anomalous Hall effect in metallic ferromagnets.

  12. Hall effect degradation of rail gun performance

    Science.gov (United States)

    Witalis, E. A.; Gunnarsson, Patrik

    1993-01-01

    The paper discusses the Hall effect and shows it to be significant in the low-density and high-field trailing part of a plasma armature. Without the Hall effect a simple armature model is derived. It exhibits properties expected from classical MHD theory and shows that the purely relativistic electric charge buildup on the rails is a fundamental gun property, leading to V(breech) = 1.5 V(muzzle). The mathematics involved in accounting for Hall effect phenomena is described. These are of two types: the Hall-skewing of the armature current and the superimposed plasma flow rotation. For decreasing gun current the two effects efficiently combine to eject armature plasma rearwards, thus creating conditions for arc separation and parasitic arcs.

  13. Iodine Hall Thruster for Space Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the Phase I program, Busek Co. Inc. tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high flow iodine feed system,...

  14. Beer City

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Shandong Province’s Qingdao is becoming China’s great beer city sicenically located on a peninsula over-looking the Pacific Ocean, Qingdao, |or Tsingtao, is a coastal city soaked in two kinds of foam. One floats in

  15. 75 FR 7467 - Gary E. Hall and Rita C. Hall; Notice of Application Accepted for Filing With the Commision...

    Science.gov (United States)

    2010-02-19

    .... Applicant: Gary E. Hall and Rita C. Hall. e. Name of Project: Potter Creek Hydroelectric Project. f. Location: The project is located on Potter Creek in Flathead County, Montana. The project would be located...: Mr. Gary E. Hall and Ms. Rita C. Hall, P.O. Box 133, Olney, MT 59927, (406) 881-2345. i. FERC Contact...

  16. Cohomological Hall algebras and character varieties

    CERN Document Server

    Davison, Ben

    2015-01-01

    In this paper we investigate the relationship between twisted and untwisted character varieties via a specific instance of the Cohomological Hall algebra for moduli of objects in 3-Calabi-Yau categories introduced by Kontsevich and Soibelman. In terms of Donaldson--Thomas theory, this relationship is completely understood via the calculations of Hausel and Villegas of the E polynomials of twisted character varieties and untwisted character stacks. We present a conjectural lift of this relationship to the cohomological Hall algebra setting.

  17. Hall effect on the triangular lattice

    OpenAIRE

    Leon Suros, Gladys Eliana; Berthod, Christophe; Giamarchi, Thierry; Millis, A.

    2008-01-01

    We investigate the high frequency Hall effect on a two-dimensional triangular lattice with nearest-neighbor hopping and a local Hubbard interaction. The complete temperature and doping dependencies of the high-frequency Hall coefficient $R_H$ are evaluated analytically and numerically for small, intermediate, and strong interactions using various approximation schemes. We find that $R_H$ follows the semiclassical $1/qn^*$ law near T=0, but exhibits a striking $T$-linear behavior with an inter...

  18. Are tent halls subject to property tax?

    Directory of Open Access Journals (Sweden)

    Mariusz Macudziński

    2016-12-01

    Full Text Available The presented publication is a response to currently asked questions and interpretative doubts of taxpayers and tax authorities, namely whether tent halls are subject to property tax. General issues connected with an entity and a subject of taxation of this tax are presented herein. The answer to the question asked is then provided through the qualification of constructions works and the allocation of tent halls in the proper category of the works, with the use of the current law.

  19. Piezo Voltage Controlled Planar Hall Effect Devices

    OpenAIRE

    Bao Zhang; Kang-Kang Meng; Mei-Yin Yang; Edmonds, K. W.; Hao Zhang; Kai-Ming Cai; Yu Sheng; Nan Zhang; Yang Ji; Jian-Hua Zhao; Hou-Zhi Zheng; Kai-You Wang

    2015-01-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the pie...

  20. Hall effect in organic layered conductors

    Directory of Open Access Journals (Sweden)

    R.A.Hasan

    2006-01-01

    Full Text Available The Hall effect in organic layered conductors with a multisheeted Fermi surfaces was considered. It is shown that the experimental study of Hall effect and magnetoresistance anisotropy at different orientations of current and a quantizing magnetic field relative to the layers makes it possible to determine the contribution of various charge carriers groups to the conductivity, and to find out the character of Fermi surface anisotropy in the plane of layers.

  1. An introduction to motivic Hall algebras

    CERN Document Server

    Bridgeland, Tom

    2010-01-01

    We give an introduction to Joyce's construction of the motivic Hall algebra of coherent sheaves on a variety M. When M is a Calabi-Yau threefold we define a semi-classical integration map from a Poisson subalgebra of this Hall algebra to the ring of functions on a symplectic torus. This material will be used in arxiv:1002.4374 to prove some basic properties of Donaldson-Thomas curve-counting invariants on Calabi-Yau threefolds.

  2. Dachang International Fishing Tackle City

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Dachang International Fishing Tackle City, in the National Industrial Park, Dachang Hui Autonomous County, Hebei Province, is 40 kilometers west of Beijing, adjacent to state highway 102.The complex was completed in April 1999, and occupies an area of 50,000 square meters with a floorage of 40,000 square meters. It comprises 368 business and display units, and a 2,100-square-meter exhibition hall. To date, 128 companies from China’s mainland, Taiwan, Japan and the Republic of Korea have set up retail outlets here. The largest of

  3. Sin City?

    DEFF Research Database (Denmark)

    Svarer, Michael; Gautier, Pieter A.; Teulings, Coen n.

    , the ones who stay in the city have significant higher divorce rates. Similarly, for the couples who married outside the city, the ones who move to the city are more likely to divorce. This correlation can be explained by both a causal and a sorting effect. We disentangle them by using the timing...

  4. Turbulence Measurements in a Tropical Zoo Hall

    Science.gov (United States)

    Eugster, Werner; Denzler, Basil; Bogdal, Christian

    2017-04-01

    The Masoala rainforest hall of the Zurich Zoo, Switzerland, covers a ground surface area of 10,856 m2 and reaches 30 m in height. With its transparent ETFE foiled roof it provides a tropical climate for a large diversity of plants and animals. In combination with an effort to estimate dry deposition of elemental mercury, we made an attempt to measure turbulent transfer velocity with an ultrasonic anemometer inside the hall. Not surprising, the largest turbulence elements were on the order of the hall dimension. Although the dimensions of the hall seem to be small (200,000 m3) for eddy covariance flux measurements and the air circulation inside the hall was extremely weak, the spectra of wind velocity components and virtual (sonic) temperature obeyed the general statistical description expected under unconstrained outdoor measurement conditions. We will present results from a two-week measurement campaign in the Masoala rainforest hall and make a suggestion for the deposition velocity to be used to estimate dry deposition of atmospheric components to the tropical vegetation surface.

  5. City PLANTastic

    DEFF Research Database (Denmark)

    The city is going green. From New York to Copenhagen vegetables are enthusiastically planted on city squares, and buildings are turning green everywhere . The word “plant” is on everyone’s lips, reflecting a growing desire to solve ecological, technical and social challenges in the city. Hovever,...... and urbanism, who reflect upon the multiple roles of plants in the future city through their most recent projects. The theme for the 2012 World in Denmark conference is City PLANTastic, which will also be explored by researchers through their works....

  6. 75 FR 22770 - Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2010-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment April 22, 2010. In accordance with the National Environmental Policy Act of 1969, as amended,...

  7. Charge carrier coherence and Hall effect in organic semiconductors.

    Science.gov (United States)

    Yi, H T; Gartstein, Y N; Podzorov, V

    2016-03-30

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.

  8. Edge reconstructions in fractional quantum Hall systems.

    Science.gov (United States)

    Joglekar, Yogesh; Nguyen, Hoang; Murthy, Ganpathy

    2003-03-01

    Two dimensional electron systems exhibiting fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs only at the edges where gapless excitations are possible [1]. We present a microscopic calculation of these egde-states at filling factors ν=1/3 and ν=2/5 using the Hamiltonian theory of the fractional quantum Hall effect [2]. We find that the quantum Hall egde undergoes a reconstruction as the confining potential, produced by the background charge density, softens [3,4]. Our results have implications to the tunneling experiments into the edge of a fractional quantum Hall system [5]. 1: X. G.Wen, Phys. Rev. Lett. 64, 2206 (1990). 2: R. Shankar and G. Murthy, Phys. Rev. Lett. 79, 4437 (1997). 3: C. de C. Chamon and X. G. Wen, Phys. Rev. B 49, 8227 (1994). 4: X. Wan, K. Yang, and E. H. Razayi, Phys. Rev. Lett. 88, 056802 (2002). 5: A.M.Chang et al., Phys. Rev. Lett. 86, 143 (2000).

  9. The Hall effect in star formation

    CERN Document Server

    Braiding, Catherine R

    2011-01-01

    Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the intermediate densities and field strengths encountered during the gravitational collapse of molecular cloud cores into protostars, and yet its role in the star formation process is not well-studied. We present a semianalytic self-similar model of the collapse of rotating isothermal molecular cloud cores with both Hall and ambipolar diffusion, and similarity solutions that demonstrate the profound influence of the Hall effect on the dynamics of collapse. The solutions show that the size and sign of the Hall parameter can change the size of the protostellar disc by up to an order of magnitude and the protostellar accretion rate by fifty per cent when the ratio of the Hall to ambipolar diffusivities is varied between -0.5 <= eta_H / eta_A <= 0.2. These changes depend upon the orien...

  10. INSTANT CITY

    DEFF Research Database (Denmark)

    Marling, Gitte; Kiib, Hans

    2013-01-01

    experiments are taking place in ‘the instant city’, and how can it be characterized? It also emphasizes the relation between city life, urban design, and the aesthetics of architecture and urban spaces. The question here is, in what way architecture and urban scenography are used as tools to support the goal...... emphasis has been laid on creating a vivid, and engaging social environment in order to create a lab for social, and architectural experi- ments. These goals challenge the city planning as well as the urban sce- nography. The article addresses the research questions: What kind of city life and social...... of an experimental and social en- gaged city environment? The analysis shows that the specific city life at the instant city, Roskilde Festival, can be characterized by being ‘open minded’, ‘playful’ and ‘inclusive’, but also by ‘a culture of laughter’ that penetrates the aesthetics and the urban scenography....

  11. Eating Cities

    DEFF Research Database (Denmark)

    Mikkelsen, Bent Egberg; Fisker, Anna Marie; Clausen, Katja Seerup

    2016-01-01

    This paper analyzed the development of a city based sustainable food strategy for the city of Aalborg. It’s based on 3 cases of food service: food for the elderly as operated by the Municipality, food the hospital patients as operated by the region and food for defense staff as operated by the st......This paper analyzed the development of a city based sustainable food strategy for the city of Aalborg. It’s based on 3 cases of food service: food for the elderly as operated by the Municipality, food the hospital patients as operated by the region and food for defense staff as operated...

  12. Leading Cities

    DEFF Research Database (Denmark)

    Pogner, Karl-Heinz

    2017-01-01

    and technical engineering; Smart Cities) is very prominent in the traditional mass media discourse, in PR / PA of tech companies and traditional municipal administrations; whereas the second one (participation; Livable Cities) is mostly enacted in social media, (local) initiatives, movements, (virtual......) communities, new forms of urban governance in municipal administration and co-competitive city networks. Both forms seem to struggle for getting voice and power in the discourses, negotiations, struggles, and conflicts in Urban Governance about the question how to manage or lead (in) a city. Talking about...

  13. Mesoscopic effects in the quantum Hall regime

    Indian Academy of Sciences (India)

    R N Bhatt; Xin Wan

    2002-02-01

    We report results of a study of (integer) quantum Hall transitions in a single or multiple Landau levels for non-interacting electrons in disordered two-dimensional systems, obtained by projecting a tight-binding Hamiltonian to the corresponding magnetic subbands. In finite-size systems, we find that mesoscopic effects often dominate, leading to apparent non-universal scaling behavior in higher Landau levels. This is because localization length, which grows exponentially with Landau level index, exceeds the system sizes amenable to the numerical study at present. When band mixing between multiple Landau levels is present, mesoscopic effects cause a crossover from a sequence of quantum Hall transitions for weak disorder to classical behavior for strong disorder. This behavior may be of relevance to experimentally observed transitions between quantum Hall states and the insulating phase at low magnetic fields.

  14. Quantized photonic spin Hall effect in graphene

    Science.gov (United States)

    Cai, Liang; Liu, Mengxia; Chen, Shizhen; Liu, Yachao; Shu, Weixing; Luo, Hailu; Wen, Shuangchun

    2017-01-01

    We examine the photonic spin Hall effect (SHE) in a graphene-substrate system with the presence of an external magnetic field. In the quantum Hall regime, we demonstrate that the in-plane and transverse spin-dependent splittings in the photonic SHE exhibit different quantized behaviors. The quantized SHE can be described as a consequence of a quantized geometric phase (Berry phase), which corresponds to the quantized spin-orbit interaction. Furthermore, an experimental scheme based on quantum weak value amplification is proposed to detect the quantized SHE in the terahertz frequency regime. By incorporating the quantum weak measurement techniques, the quantized photonic SHE holds great promise for detecting quantized Hall conductivity and the Berry phase. These results may bridge the gap between the electronic SHE and photonic SHE in graphene.

  15. Graphene-based Hall Sensors for direct magnetic imaging by using Scanning Hall Probe Microscope

    Science.gov (United States)

    Sonusen, Selda; Aksoy, Seda; Dede, Munir; Oral, Ahmet

    2013-03-01

    Graphene has been attracting great interest due to its unique electronic and mechanical properties for both fundamental and experimental studies since 2004. Graphene is a promising material for many applications in high speed electronic and spintronic devices as well as sensors. Its high mobility makes graphene a good candidate for magnetic imaging in Scanning Hall Probe Microscope (SHPM). Hall probes are used to scan the magnetic samples to image magnetic domains in SHPM. In this work, single layer graphene produced by chemical vapor deposition technique is used to fabricate Hall sensors by optical and the e-beam lithography with sizes from 500 nm to a few micrometers. The Hall crosses are characterized by Raman mapping to make sure that they are made of a single layer graphene. The Graphene Hall Sensors noise spectra is measured as a function of different bias currents and carrier concentrations at 300 K, 77 K and 4.24K. The imaging performance of the Hall sensor will be demonstrated at different temperatures by imaging a garnet crystal using a Low Temperature Scanning Hall Probe Microscope (LT-SHPM).

  16. EL CROWN HALL. CONTEXTO Y PROYECTO

    Directory of Open Access Journals (Sweden)

    Laura Lizondo Sevilla

    2010-05-01

    Full Text Available RESUMEN El artículo enmarca el edificio del Crown Hall en el contexto docente y arquitectónico de Mies van der Rohe. Revisa sus inicios en la Bauhaus con su primera intervención en un espacio docente para la Bauhaus de Berlín en 1932, así como su marcha a Estados Unidos, los planteamientos arquitectónicos del campus del IIT y el proyecto del Crown Hall. El texto incide en el estudio del proceso proyectual del Crown Hall analizando la evolución de su concepción arquitectónica a través de las diferentes versiones del proyecto. Se constata la transición desde los primeros planteamientos arquitectónicos de los edificios del campus del IIT proyectados por Mies hacia el planteamiento del gran espacio unitario del Crown Hall. Este proyecto se puede entender desde la creciente importancia de la estructura, la claridad constructiva y el manejo del acero y vidrio como únicos materiales de la imagen del edificio y el carácter flexible y unitario del espacio. Finalmente se hace referencia al concepto del "espacio universal" en la arquitectura de Mies, como un concepto abstracto que supera los de flexibilidad de uso o unidad espacial, insinuando, a modo de reflexión, las principales variables que definirían el espacio universal miesiano.SUMMARY The article showcases the Crown Hall building in the educational and architectural context of Mies van der Rohe. It reviews his beginnings in the Bauhaus with his first intervention in an educational space for the Bauhaus of Berlin in 1932, as well as his sojourn to the United States, and the architectural approaches to the IIT campus and the Crown Hall project. The text touches on the study of the planning process for the Crown Hall, analysing the evolution of its architectural conception, through the different versions of the project. The article covers the transition from the first architectural approaches for the IIT campus buildings, planned by Mies, to the approach of the large unitary space of

  17. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...

  18. Inverse spin Hall effect by spin injection

    Science.gov (United States)

    Liu, S. Y.; Horing, Norman J. M.; Lei, X. L.

    2007-09-01

    Motivated by a recent experiment [S. O. Valenzuela and M. Tinkham, Nature (London) 442, 176 (2006)], the authors present a quantitative microscopic theory to investigate the inverse spin-Hall effect with spin injection into aluminum considering both intrinsic and extrinsic spin-orbit couplings using the orthogonalized-plane-wave method. Their theoretical results are in good agreement with the experimental data. It is also clear that the magnitude of the anomalous Hall resistivity is mainly due to contributions from extrinsic skew scattering.

  19. Integer quantum Hall effect in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Jellal, Ahmed, E-mail: ahmed.jellal@gmail.com [Saudi Center for Theoretical Physics, Dhahran (Saudi Arabia); Theoretical Physics Group, Faculty of Sciences, Chouaïb Doukkali University, 24000 El Jadida (Morocco)

    2016-04-08

    We study the quantum Hall effect in a monolayer graphene by using an approach based on thermodynamical properties. This can be done by considering a system of Dirac particles in an electromagnetic field and taking into account of the edges effect as a pseudo-potential varying continuously along the x direction. At low temperature and in the weak electric field limit, we explicitly determine the thermodynamical potential. With this, we derive the particle numbers in terms of the quantized flux and therefore the Hall conductivity immediately follows.

  20. Atypical Cities

    Science.gov (United States)

    DiJulio, Betsy

    2011-01-01

    In this creative challenge, Surrealism and one-point perspective combine to produce images that not only go "beyond the real" but also beyond the ubiquitous "imaginary city" assignment often used to teach one-point perspective. Perhaps the difference is that in the "atypical cities challenge," an understanding of one-point perspective is a means…

  1. Soft Cities

    DEFF Research Database (Denmark)

    Brix, Anders; Yoneda, Akira; Nakamura, Kiyoshi

    2015-01-01

    of a sustainable future. The project is the result of a joint research study between Denmark and Japan. Taking as its example the city of Kyoto, the project investigates some possible strategies on how cities more generally may be transformed into liveable, healthy and ecologically sensible environments....

  2. INSTANT CITY

    DEFF Research Database (Denmark)

    Marling, Gitte; Kiib, Hans

    2013-01-01

    experiments are taking place in ‘the instant city’, and how can it be characterized? It also emphasizes the relation between city life, urban design, and the aesthetics of architecture and urban spaces. The question here is, in what way architecture and urban scenography are used as tools to support the goal...... of an experimental and social en- gaged city environment? The analysis shows that the specific city life at the instant city, Roskilde Festival, can be characterized by being ‘open minded’, ‘playful’ and ‘inclusive’, but also by ‘a culture of laughter’ that penetrates the aesthetics and the urban scenography.......This article analyses Roskilde Festival as an Instant City. For more than 40 years, Roskilde Festival has had many thousands participants for a weeklong festival on music, performances and cultural experiences in a layout designed as an urban environment. During the last ten years, in- creasing...

  3. Destruction of the Fractional Quantum Hall Effect by Disorder

    Science.gov (United States)

    Laughlin, R. B.

    1985-07-01

    It is suggested that Hall steps in the fractional quantum Hall effect are physically similar to those in the ordinary quantum Hall effect. This proposition leads to a simple scaling diagram containing a new type of fixed point, which is identified with the destruction of the fractional states by disorder. 15 refs., 3 figs.

  4. Digital technology impacts on the Arnhem transfer hall structural design

    NARCIS (Netherlands)

    Van de Straat, R.; Hofman, S.; Coenders, J.L.; Paul, J.C.

    2015-01-01

    The new Transfer Hall in Arnhem is one of the key projects to prepare the Dutch railways for the increased future demands for capacity. UNStudio developed a master plan in 1996 for the station area of which the completion of the Transfer Hall in 2015 will be a final milestone. The Transfer Hall is a

  5. New type of magnetization equipment using a commercial Hall sensor

    Science.gov (United States)

    Nishioka, T.; Sato, N. K.

    2004-05-01

    We have developed a new method of the magnetization measurement using a commercial Hall sensor (Hall magnetometer), which enables us to measure the static magnetization very easily at temperatures as low as about 0.1 K and under pressure. We describe specifications of the Hall magnetometer, and show results of the magnetization measurement for UGe 2 as an example.

  6. Towards a Better Understanding of the Anomalous Hall Effect

    Science.gov (United States)

    Yue, Di; Jin, Xiaofeng

    2017-01-01

    Recent experimental efforts to identify the intrinsic and extrinsic contributions in the anomalous Hall effect are reviewed. Benefited from the experimental control of artificial impurity density in single crystalline magnetic thin films, a comprehensive physical picture of the anomalous Hall effect involving multiple competing scattering processes has been established. Some new insights into the microscopic mechanisms of the anomalous Hall effect are discussed.

  7. Accurate micro Hall effect measurements on scribe line pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei

    2009-01-01

    Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...

  8. Parametric Investigations of Non-Conventional Hall Thruster

    Energy Technology Data Exchange (ETDEWEB)

    Raitses, Y.; Fisch, N.J.

    2001-01-12

    Hall thrusters might better scale to low power with non-conventional geometry. A 9 cm cylindrical, ceramic-channel, Hall thruster with a cusp-type magnetic field distribution has been investigated. It exhibits discharge characteristics similar to conventional coaxial Hall thrusters, but does not expose as much channel surface. Significantly, its operation is not accompanied by large amplitude discharge low frequency oscillations.

  9. Digital technology impacts on the Arnhem transfer hall structural design

    NARCIS (Netherlands)

    Van de Straat, R.; Hofman, S.; Coenders, J.L.; Paul, J.C.

    2015-01-01

    The new Transfer Hall in Arnhem is one of the key projects to prepare the Dutch railways for the increased future demands for capacity. UNStudio developed a master plan in 1996 for the station area of which the completion of the Transfer Hall in 2015 will be a final milestone. The Transfer Hall is a

  10. Improved Hall-Effect Sensors For Magnetic Memories

    Science.gov (United States)

    Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.; Chen, Y. C.; Bhattacharya, Pallab K.

    1993-01-01

    High-electron-mobility sensor films deposited on superlattice buffer (strain) layers. Improved Hall-effect sensors offer combination of adequate response and high speed needed for use in micromagnet/Hall-effect random-access memories. Hall-effect material chosen for use in sensors is InAs.

  11. Dark cities? Developing a methodology for researching dark tourism in European cities

    OpenAIRE

    Kennell, James; Powell, Raymond

    2016-01-01

    Despite the recent growth of research into dark tourism (Dale & Robinson, 2011; Lennon & Foley, 2000; Stone, 2013; Tarlow, 2005) and the growth of the dark tourism market (Biran & Hyde, 2013; Stone 2005; Stone & Sharpley, 2008), there has been little interest shown in understanding the relationship between dark tourism and urban tourism (Page & Hall 2002). This paper presents the initial findings of a research project that investigates the dark tourism products offered by European cities. A s...

  12. Dark cities? Developing a methodology for researching dark tourism in European cities

    OpenAIRE

    Kennell, James; Powell, Raymond

    2016-01-01

    Despite the recent growth of research into dark tourism (Dale & Robinson, 2011; Lennon & Foley, 2000; Stone, 2013; Tarlow, 2005) and the growth of the dark tourism market (Biran & Hyde, 2013; Stone 2005; Stone & Sharpley, 2008), there has been little interest shown in understanding the relationship between dark tourism and urban tourism (Page & Hall 2002). This paper presents the initial findings of a research project that investigates the dark tourism products offered by European cities. A s...

  13. Inertial-Hall effect: the influence of rotation on the Hall conductivity

    Science.gov (United States)

    Brandão, Julio E.; Moraes, F.; Cunha, M. M.; Lima, Jonas R. F.; Filgueiras, C.

    Inertial effects play an important role in classical mechanics but have been largely overlooked in quantum mechanics. Nevertheless, the analogy between inertial forces on mass particles and electromagnetic forces on charged particles is not new. In this paper, we consider a rotating non-interacting planar two-dimensional electron gas with a perpendicular uniform magnetic field and investigate the effects of the rotation in the Hall conductivity. The rotation introduces a shift and a split in the Landau levels. As a consequence of the break of the degeneracy, the counting of the states fully occupied below the Fermi energy increases, tuning the Hall quantization steps. The rotation also changes the quantum Hall plateau widths. Additionally, we find the Hall quantization steps as a function of rotation at a fixed value of the magnetic field.

  14. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-05-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  15. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators.

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O; Valentí, Roser

    2016-05-17

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions.

  16. The magneto-Hall difference and the planar extraordinary Hall balance

    Directory of Open Access Journals (Sweden)

    S. L. Zhang

    2016-04-01

    Full Text Available The extraordinary Hall balance (EHB is a general device concept that harnesses the net extraordinary Hall effect (EHE arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect, will be discussed. A discrepancy between the magnetization and the Hall effect, called the magneto-Hall difference (MHD is found, which is not expected in conventional EHE systems. By taking advantage of the MHD effect, and by optimizing the materials structure, magnetoresistance ratios in excess of 40,000% can be achieved at room-temperature. We present a new design, the planar EHB, which has the potential to achieve significantly larger magnetoresistance ratios.

  17. The magneto-Hall difference and the planar extraordinary Hall balance

    Science.gov (United States)

    Zhang, S. L.; Hesjedal, T.

    2016-04-01

    The extraordinary Hall balance (EHB) is a general device concept that harnesses the net extraordinary Hall effect (EHE) arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect, will be discussed. A discrepancy between the magnetization and the Hall effect, called the magneto-Hall difference (MHD) is found, which is not expected in conventional EHE systems. By taking advantage of the MHD effect, and by optimizing the materials structure, magnetoresistance ratios in excess of 40,000% can be achieved at room-temperature. We present a new design, the planar EHB, which has the potential to achieve significantly larger magnetoresistance ratios.

  18. Inertial-Hall effect: the influence of rotation on the Hall conductivity

    Directory of Open Access Journals (Sweden)

    Julio E. Brandão

    2015-01-01

    Full Text Available Inertial effects play an important role in classical mechanics but have been largely overlooked in quantum mechanics. Nevertheless, the analogy between inertial forces on mass particles and electromagnetic forces on charged particles is not new. In this paper, we consider a rotating non-interacting planar two-dimensional electron gas with a perpendicular uniform magnetic field and investigate the effects of the rotation in the Hall conductivity. The rotation introduces a shift and a split in the Landau levels. As a consequence of the break of the degeneracy, the counting of the states fully occupied below the Fermi energy increases, tuning the Hall quantization steps. The rotation also changes the quantum Hall plateau widths. Additionally, we find the Hall quantization steps as a function of rotation at a fixed value of the magnetic field.

  19. Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

    Science.gov (United States)

    Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

    2016-01-01

    Electronic states with non-trivial topology host a number of novel phenomena with potential for revolutionizing information technology. The quantum anomalous Hall effect provides spin-polarized dissipation-free transport of electrons, while the quantum spin Hall effect in combination with superconductivity has been proposed as the basis for realizing decoherence-free quantum computing. We introduce a new strategy for realizing these effects, namely by hole and electron doping kagome lattice Mott insulators through, for instance, chemical substitution. As an example, we apply this new approach to the natural mineral herbertsmithite. We prove the feasibility of the proposed modifications by performing ab-initio density functional theory calculations and demonstrate the occurrence of the predicted effects using realistic models. Our results herald a new family of quantum anomalous Hall and quantum spin Hall insulators at affordable energy/temperature scales based on kagome lattices of transition metal ions. PMID:27185665

  20. Hall instability of solar flux tubes

    CERN Document Server

    Pandey, B P

    2011-01-01

    The magnetic network which consists of vertical flux tubes located in intergranular lanes is dominated by Hall drift in the photosphere-lower chromosphere region ($\\lesssim 1\\,{Mm}$). In the internetwork regions, Hall drift dominates above $0.25\\,{Mm}$ in the photosphere and below $2.5\\,{Mm}$ in the chromosphere. Although Hall drift does not cause any dissipation in the ambient plasma, it can destabilise flux tubes and magnetic elements in the presence of an azimuthal shear flow, which destabilises whistler waves. The physical mechanism of this instability is quite simple: the shear flow twists the radial magnetic field and generates azimuthal field; torsional oscillations of the azimuthal field in turn generates the radial field completing a feedback loop. The maximum growth rate of the Hall instability is proportional to the absolute value of the shear gradient and is dependent on the ambient diffusivity. The diffusivity also determines the cut--off wavenumber which is narrower for the stronger fields. We a...

  1. Room acoustic properties of concert halls

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1996-01-01

    A large database of values of various room acoustic parameters has provided the basis for statistical analyses of how and how much the acoustic properties of concert halls are influenced by their size, shape, and absorption area (as deduced from measured reverberation time). The data have been...

  2. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...

  3. Anomalous Hall Effect for chiral fermions

    CERN Document Server

    Zhang, P -M

    2014-01-01

    Semiclassical chiral fermions manifest the anomalous spin-Hall effect: when put into a pure electric field, they suffer a side jump, analogous to what happens to their massive counterparts in non-commutative mechanics. The transverse shift is consistent with the conservation of the angular momentum. In a pure magnetic field a cork-screw-like, spiraling motion is found.

  4. Supersymmetry in the Fractional Quantum Hall Regime

    CERN Document Server

    Sagi, Eran

    2016-01-01

    Supersymmetry (SUSY) is a symmetry transforming bosons to fermions and vice versa. Indications of its existence have been extensively sought after in high-energy experiments. However, signatures of SUSY have yet to be detected. In this manuscript we propose a condensed matter realization of SUSY on the edge of a Read-Rezayi quantum Hall state, given by filling factors of the form $\

  5. Hall Effect Thruster Ground Testing Challenges

    Science.gov (United States)

    2009-08-18

    conditional stability of the inverted pendulum thrust stand provides improved measurement sensitivity.5 With the displacement of the inverted pendulum...July 2005. 12Samiento, C., “RHETT2/ EPDM Hall Thruster Propulsion System Electromagnetic Compatability Evaluation,” Proceed- ings of the 25th

  6. Development and applications of mesoscopic hall microprobes

    NARCIS (Netherlands)

    Novoselov, Konstantin S.

    2004-01-01

    This thesis is devoted to the further development of the local Hall magnetometery technique, and its application for studying ferromagnetic domain wall propagation on the sub-atomic scale. First the ballistic electron transport in a strong, non-uniform magnetic field is discussed. Than a possible in

  7. Fractional Quantization of the Hall Effect

    Science.gov (United States)

    Laughlin, R. B.

    1984-02-27

    The Fractional Quantum Hall Effect is caused by the condensation of a two-dimensional electron gas in a strong magnetic field into a new type of macroscopic ground state, the elementary excitations of which are fermions of charge 1/m, where m is an odd integer. A mathematical description is presented.

  8. Moderate positive spin Hall angle in uranium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del, E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Springell, Ross [H. H. Will Laboratory, University of Bristol, Bristol BS2 8BS (United Kingdom); Miller, Casey W., E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York 14623 (United States)

    2015-12-07

    We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  9. Dust exposure in indoor climbing halls.

    Science.gov (United States)

    Weinbruch, Stephan; Dirsch, Thomas; Ebert, Martin; Hofmann, Heiko; Kandler, Konrad

    2008-05-01

    The use of hydrated magnesium carbonate hydroxide (magnesia alba) for drying the hands is a strong source for particulate matter in indoor climbing halls. Particle mass concentrations (PM10, PM2.5 and PM1) were measured with an optical particle counter in 9 indoor climbing halls and in 5 sports halls. Mean values for PM10 in indoor climbing halls are generally on the order of 200-500 microg m(-3). For periods of high activity, which last for several hours, PM10 values between 1000 and 4000 microg m(-3) were observed. PM(2.5) is on the order of 30-100 microg m(-3) and reaches values up to 500 microg m(-3), if many users are present. In sports halls, the mass concentrations are usually much lower (PM10 sport in which magnesia alba is also used) similar dust concentrations as for indoor climbing were observed. The size distribution and the total particle number concentration (3.7 nm-10 microm electrical mobility diameter) were determined in one climbing hall by an electrical aerosol spectrometer. The highest number concentrations were between 8000 and 12 000 cm(-3), indicating that the use of magnesia alba is no strong source for ultrafine particles. Scanning electron microscopy and energy-dispersive X-ray microanalysis revealed that virtually all particles are hydrated magnesium carbonate hydroxide. In-situ experiments in an environmental scanning electron microscope showed that the particles do not dissolve at relative humidities up to 100%. Thus, it is concluded that solid particles of magnesia alba are airborne and have the potential to deposit in the human respiratory tract. The particle mass concentrations in indoor climbing halls are much higher than those reported for schools and reach, in many cases, levels which are observed for industrial occupations. The observed dust concentrations are below the current occupational exposure limits in Germany of 3 and 10 mg m(-3) for respirable and inhalable dust. However, the dust concentrations exceed the German guide

  10. The Magneto-Hall Difference and the Planar Extraordinary Hall Balance

    OpenAIRE

    S. L. Zhang; Hesjedal, T.

    2016-01-01

    The extraordinary Hall balance (EHB) is a general device concept that harnesses the net extraordinary Hall effect (EHE) arising from two independent magnetic layers, which are electrically in parallel. Different EHB behavior can be achieved by tuning the strength and type of interlayer coupling, i.e., ferromagnetic or antiferromagnetic of varying strength, allowing for logic and memory applications. The physics of the EHE in such a multilayered systems, especially the interface-induced effect...

  11. Flying Cities

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan

    2008-01-01

    . This cross-modal interaction not only supports our artistic messages, but also aims at providing anyone with a pleasant and stimulating feedback from her/his speech activity. As the feedback we have received when presenting Flying Cities was very positive, our objective is now to cross the bridge between art......Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction...

  12. City Branding

    DEFF Research Database (Denmark)

    Frimann, Søren; Stigel, Jørgen

    2006-01-01

    with their relatively concrete dimensions are absent when the main question is one of values. Furthermore, when  the relatively straightforward identification and power structures of corporations and consumers are replaced by the more diversified structures of city government, their poplulations, and potential visitors......, problems seem to multiply in what has becom known as city branding. This analysis of the communicational aspects of two Danish provincial towns´ branding efforts examines both their internally and externally directed communication. It demonstrates that an insufficient understanding of - or willingness...... to face - these differences will inevitably hamper such branding efforts because of the consequential inconsistencies. Finally, paths to more effective city branding are indicated...

  13. Sin City?

    DEFF Research Database (Denmark)

    Svarer, Michael; Gautier, Pieter A.; Teulings, Coen n.

    , the ones who stay in the city have significant higher divorce rates. Similarly, for the couples who married outside the city, the ones who move to the city are more likely to divorce. This correlation can be explained by both a causal and a sorting effect. We disentangle them by using the timing......-of-events approach. In addition we use information on father's location as an instrument. We find that the sorting effect dominates. Moving to the countryside is therefore not a cheap way to prolong relationships....

  14. Topological honeycomb magnon Hall effect: A calculation of thermal Hall conductivity of magnetic spin excitations

    Science.gov (United States)

    Owerre, S. A.

    2016-07-01

    Quite recently, the magnon Hall effect of spin excitations has been observed experimentally on the kagome and pyrochlore lattices. The thermal Hall conductivity κxy changes sign as a function of magnetic field or temperature on the kagome lattice, and κxy changes sign upon reversing the sign of the magnetic field on the pyrochlore lattice. Motivated by these recent exciting experimental observations, we theoretically propose a simple realization of the magnon Hall effect in a two-band model on the honeycomb lattice. The magnon Hall effect of spin excitations arises in the usual way via the breaking of inversion symmetry of the lattice, however, by a next-nearest-neighbour Dzyaloshinsky-Moriya interaction. We find that κxy has a fixed sign for all parameter regimes considered. These results are in contrast to the Lieb, kagome, and pyrochlore lattices. We further show that the low-temperature dependence on the magnon Hall conductivity follows a T2 law, as opposed to the kagome and pyrochlore lattices. These results suggest an experimental procedure to measure thermal Hall conductivity within a class of 2D honeycomb quantum magnets and ultracold atoms trapped in a honeycomb optical lattice.

  15. Comparison of secondary islands in collisional reconnection to Hall reconnection.

    Science.gov (United States)

    Shepherd, L S; Cassak, P A

    2010-07-02

    Large-scale resistive Hall-magnetohydrodynamic simulations of the transition from Sweet-Parker (collisional) to Hall (collisionless) magnetic reconnection are presented; the first to separate secondary islands from collisionless effects. Three main results are described. There exists a regime with secondary islands but without collisionless effects, and the reconnection rate is faster than Sweet-Parker, but significantly slower than Hall reconnection. This implies that secondary islands do not cause the fastest reconnection rates. The onset of Hall reconnection ejects secondary islands from the vicinity of the X line, implying that energy is released more rapidly during Hall reconnection. Coronal applications are discussed.

  16. Parallel Hall effect from 3D single-component metamaterials

    CERN Document Server

    Kern, Christian; Wegener, Martin

    2015-01-01

    We propose a class of three-dimensional metamaterial architectures composed of a single doped semiconductor (e.g., n-Si) in air or vacuum that lead to unusual effective behavior of the classical Hall effect. Using an anisotropic structure, we numerically demonstrate a Hall voltage that is parallel---rather than orthogonal---to the external static magnetic-field vector ("parallel Hall effect"). The sign of this parallel Hall voltage can be determined by a structure parameter. Together with the previously demonstrated positive or negative orthogonal Hall voltage, we demonstrate four different sign combinations

  17. City Streets

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set contains roadway centerlines for city streets found on the USGS 1:24,000 mapping series. In some areas, these roadways are current through the 2000...

  18. City Branding

    DEFF Research Database (Denmark)

    Frimann, Søren; Stigel, Jørgen

    2006-01-01

    with their relatively concrete dimensions are absent when the main question is one of values. Furthermore, when  the relatively straightforward identification and power structures of corporations and consumers are replaced by the more diversified structures of city government, their poplulations, and potential visitors...... to face - these differences will inevitably hamper such branding efforts because of the consequential inconsistencies. Finally, paths to more effective city branding are indicated...

  19. Model cities

    OpenAIRE

    Batty, M.

    2007-01-01

    The term ?model? is now central to our thinking about how weunderstand and design cities. We suggest a variety of ways inwhich we use ?models?, linking these ideas to Abercrombie?sexposition of Town and Country Planning which represented thestate of the art fifty years ago. Here we focus on using models asphysical representations of the city, tracing the development ofsymbolic models where the focus is on simulating how functiongenerates form, to iconic models where the focus is on representi...

  20. Diagnostics Systems for Permanent Hall Thrusters Development

    Science.gov (United States)

    Ferreira, Jose Leonardo; Soares Ferreira, Ivan; Santos, Jean; Miranda, Rodrigo; Possa, M. Gabriela

    This work describes the development of Permanent Magnet Hall Effect Plasma Thruster (PHALL) and its diagnostic systems at The Plasma Physics Laboratory of University of Brasilia. The project consists on the construction and characterization of plasma propulsion engines based on the Hall Effect. Electric thrusters have been employed in over 220 successful space missions. Two types stand out: the Hall-Effect Thruster (HET) and the Gridded Ion Engine (GIE). The first, which we deal with in this project, has the advantage of greater simplicity of operation, a smaller weight for the propulsion subsystem and a longer shelf life. It can operate in two configurations: magnetic layer and anode layer, the difference between the two lying in the positioning of the anode inside the plasma channel. A Hall-Effect Thruster-HET is a type of plasma thruster in which the propellant gas is ionized and accelerated by a magneto hydrodynamic effect combined with electrostatic ion acceleration. So the essential operating principle of the HET is that it uses a J x B force and an electrostatic potential to accelerate ions up to high speeds. In a HET, the attractive negative charge is provided by electrons at the open end of the Thruster instead of a grid, as in the case of the electrostatic ion thrusters. A strong radial magnetic field is used to hold the electrons in place, with the combination of the magnetic field and the electrostatic potential force generating a fast circulating electron current, the Hall current, around the axis of the Thruster, mainly composed by drifting electrons in an ion plasma background. Only a slow axial drift towards the anode occurs. The main attractive features of the Hall-Effect Thruster are its simple design and operating principles. Most of the Hall-Effect Thrusters use electromagnet coils to produce the main magnetic field responsible for plasma generation and acceleration. In this paper we present a different new concept, a Permanent Magnet Hall

  1. Serial Cities: Australian Literary Cities and the Rhetoric of Scale

    Directory of Open Access Journals (Sweden)

    Brigid Rooney

    2015-03-01

    Sophie Cunningham, Melbourne (2011 Matthew Condon, Brisbane (2010 Paul Daley, Canberra (2012 Delia Falconer, Sydney (2010 Kerryn Goldsworthy, Adelaide (2011 Eleanor Hogan, Alice Springs (2012 Tess Lea, Darwin (2014 Peter Timms, In Search of Hobart (2012 David Whish-Wilson, Perth (2013

  2. The Hall Algebra of Cyclic Serial Algebra

    Institute of Scientific and Technical Information of China (English)

    郭晋云

    1994-01-01

    In this paper, orders <1 and <2 on ((Z)+)nm are introduced and also regarded as orders on the isomorphism classes of finite modules of finite .cyclic algebra R with n simple modules and all the indecomposable projective modules have length m through a one-to-one correspondence between ((Z)+)nm and the isomorphism classes of finite R modules. Using this we prove that the Hall algebra of a cyclic serial algebra is identified with its Loewy subalgebra, and its rational extension has a basis of BPW type, and is a (((Z)+)nm, <2) filtered ring with the associated graded ring as an iterated skew polynomial ring. These results are also generalized to the Hall algebra of a tube over a finite field.

  3. Three halls for music performance in Chile

    Science.gov (United States)

    Delannoy, Jaime; Heuffemann, Carolina; Ramirez, Daniel; Galvez, Fernando

    2002-11-01

    The primary purpose of this work was to investigate about the present acoustic conditions of used architectonic spaces in Santiago of Chile for orchestras of classic music performance. The studied halls were three: Aula Magna Universidad de Santiago, Teatro Municipal de Nunoa, and Teatro Baquedano. The used methodology was based on studies made by L. Beranek, M. Barron, among others, in concert halls worldwide. As it guides, for the measurement procedure, physical parameters RT, EDT, C50, C80, LF, BR, G, U50 were evaluated according to norm ISO 3382. On the other hand, it has been defined, to proposal way, a questionnaire of subjective valuation directed to musicians, specialized conductors, and listeners.

  4. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...... frequency sounds are typically highly amplified, they play an important role in the subjective ratings and the 63-Hz-band must be included in objective measurements and recommendations....

  5. Judy Estes Hall (1940-2015).

    Science.gov (United States)

    Sammons, Morgan T; Boucher, Andrew

    2016-01-01

    Presents an obituary for Judy Estes Hall, who passed away on November 24, 2015. Hall served as the Executive Officer of the National Register of Health Service Psychologists until her retirement in 2013. She is a recognized expert in the development of education and training standards for the profession of psychology, she also made significant contributions in the field of international psychology, where she was a renowned expert in cross-national credentialing and an advocate for commonality in licensing standards. She was the coauthor of one edited volume and author of more than 60 journal articles, book chapters, and professional publications. A passionate advocate for the advancement of women in psychology, a devoted mother and grandmother, a connoisseur of wine and international traveler extraordinaire, she touched the personal and professional lives of many. (PsycINFO Database Record

  6. Hall Scrambling on Black Hole Horizon

    CERN Document Server

    Fischler, Willy

    2015-01-01

    We explore the effect of the electrodynamics $\\theta$-angle on the macroscopic properties of black hole horizons. Using only classical Einstein-Maxwell-Chern-Simons theory in (3+1)-dimensions, in the form of the membrane paradigm, we show that in the presence of the $\\theta$-term, a black hole horizon behaves as a Hall conductor, for an observer hovering outside. We study how localized perturbations created on the stretched horizon scramble on the horizon by dropping a charged particle. We show that the $\\theta$-angle affects the way perturbations scramble on the horizon, in particular, it introduces vortices without changing the scrambling time. This Hall scrambling of information is also expected to occur on cosmological horizons.

  7. Music hall Markneukirchen; Musikhalle in Markneukirchen

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-01-01

    The article presents the new building of the music hall Markneukirchen. From the planned use of the building result very high demands on the ventilation system in order to keep to a sound power level of less than 30 dB(A) in the hall. The building services are dealt with using numerous flowsheets and diagrams: Heat supply, ventilation system, sanitary system, building management, instrumentation and control, electric and lighting systems. (BWI) [Deutsch] Der vorliegende Beitrag stellt den Neubau der Musikhalle Markneukirchen vor. Durch das Nutzungskonzept ergeben sich fuer die Einhaltung eines Schalleistungspegels von weniger als 30 dB(A) im Saalbereich an die Lueftungsanlage sehr hohe Ansprueche. Es werden die raumlufttechnischen Anlagen anhand zahlreicher Flussbilder und Abbildungen vorgestellt: Waermeversorgung, Lueftungstechnik, Sanitaertechnik, Gebaeudeleit- und MSR-Technik, Elektro- und Lichttechnik. (BWI)

  8. Drone City

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2016-01-01

    design” will be used as a background perspective to reflect upon the future of drones in cities. The other perspective used to frame the phenomenon is the emerging discourse of the “smart city”. A city of proliferating digital information and data communication may be termed a smart city as shorthand......This paper address the phenomenon of drones and their potential relationship with the city from the point of view of the so-called “mobilities turn”. This is done in such a way that turns attention to a recent redevelopment of the “turn” towards design; so the emerging perspective of “mobilities...... for a new urban condition where cities are networked and connected (as well as disconnected) from the local block to global digital spheres. In the midst of many of the well-known data-creating devices (e.g. Bluetooth, radio-frequency identification (RFID), GPS, smartphone applications) there is a “new kid...

  9. SPS beam to the West Hall

    CERN Multimedia

    1976-01-01

    One of the two target stations feeding the West Hall (see Annual Report 1976). After the proton beam was split into three branches, the outer two were directed on to targets in the cast iron shielding box, the centre one passing through the box to another target station downstream. Five different targets could be put in each beam, controlled by the mechanism seen on top.

  10. Geometric Photonic Spin Hall Effect with Metapolarization

    OpenAIRE

    2014-01-01

    We develop a geometric photonic spin Hall effect (PSHE) which manifests as spin-dependent shift in momentum space. It originates from an effective space-variant Pancharatnam-Berry (PB) phase created by artificially engineering the polarization distribution of the incident light. Unlikely the previously reported PSHE involving the light-matter interaction, the resulting spin-dependent splitting in the geometric PSHE is purely geometrically depend upon the polarization distribution of light whi...

  11. Thermal Characterization of a Hall Effect Thruster

    Science.gov (United States)

    2008-03-01

    Material Curie Temperature Iron 770 °C Nickel 358 °C Cobalt 1130 °C Gadolinium 20 °C Terfenol 380-430 °C Alnico 850 °C Hard Ferrites 400-700...C Barium Ferrite 450 °C Hall Effect thrusters generally use iron magnets with a Curie temperature of 770 °C. Decreasing the magnetic strength

  12. Electron-wall Interaction in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; M. Keidar; N.J. Fisch

    2005-02-11

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates.

  13. Homotopy arguments for quantized Hall conductivity

    CERN Document Server

    Richter, T

    2002-01-01

    Using the strong localization bounds obtained by the Aizenman-Molcanov method for a particle in a magnetic field and a disordered potential, we show that the zero-temperature Hall conductivity of a gas of such particles is quantized and constant as long as both Fermi energy and disorder coupling parameter vary in a region of strong localization of the corresponding two-dimensional phase diagram.

  14. Industrial steel hall with bridge grane

    OpenAIRE

    Jurejevčič, Nejc

    2016-01-01

    In introduction this diploma thesis describes all main characteristics of (single block)? industrial steel hall with bridge crane. Load arrangement on the supporting structure which covers general actions (snow load and wind action), self-weight and dynamic load of bridge crane was designed with moment resisting frame in transverse direction and frame with concentric diagonal bracing in longitudinual direction. Actions induced by crane bridge was considered in design of runway beam. Steel hal...

  15. The Hall D Physics Program at JLab

    Energy Technology Data Exchange (ETDEWEB)

    Leckey, John P. [Indiana U.

    2012-09-01

    GlueX is one of the flagship experiments of the 12 GeV era at the Thomas Jefferson National Accelerator Facility (JLab). The energy of the electron accelerator at JLab is presently undergoing an upgrade from 6 GeV to 12 GeV and a 4th experimental hall (Hall D) is being added. The GlueX experimental apparatus consists of a tagged coherent bremsstrahlung photon beam incident on a liquid hydrogen target. The photoproduced mesons, which are created inside of a 2.2 T solenoid, will then pass through a pair of drift chambers and eventually deposit their energy into either of two calorimeters, depending on their respective angles. GlueX will attempt to map out the light meson spectrum and search for meson-gluon hybrids to better understand the confinement of quarks and gluons in quantum chromodynamics (QCD). There is little data on the photoproduction of light mesons and the GlueX experiment will exceed the current photoproduction data by several orders of magnitude in the first year alone. Photoproduction is specifically well suited to search for meson-gluon hybrids because in the flux tube model the production cross-sections are higher for meson-gluon hybrids from photons, with the spins of the virtual quark-antiquark pair aligned, than from other sources such as pions, with the spins of the quark-antiquark pair anti-aligned. There are also other Hall D experiments proposed to look for physics beyond the Standard Model by studying Eta rare or forbidden decay channels such as eta to two neutral pions. The 12 GeV upgrade of the JLab accelerator and the complete physics program of Hall D will be presented.

  16. Views of the ATLAS experimental hall

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The shell of the ATLAS detector is seen from many angles within its cavernous underground hall. All of the eight huge toroid magnets have been installed and fixed in place. The core of the detector, the largest of its type in the world, will soon be filled with many different detector-elements to observe the results of proton-proton collisions at the LHC when it is turned on in 2008.

  17. Acoustics in rock and pop music halls

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues in D...... frequency sounds are typically highly amplified, they play an important role in the subjective ratings and the 63-Hz-band must be included in objective measurements and recommendations....

  18. SERVIR Town Hall - Connecting Space to Village

    Science.gov (United States)

    Limaye, Ashutosh S.; Searby, Nancy D.; Irwin, Daniel; Albers, Cerese

    2013-01-01

    SERVIR, a joint NASA-USAID project, strives to improve environmental decision making through the use of Earth observations, models, and geospatial technology innovations. SERVIR connects these assets with the needs of end users in Mesoamerica, East Africa, and Hindu Kush-Himalaya regions. This Town Hall meeting will engage the AGU community by exploring examples of connecting Space to Village with SERVIR science applications.

  19. A Magnetic Balance with Hall Effect Sensors

    Science.gov (United States)

    Sawada, Hideo; Kunimasu, Tetsuya; Suda, Shinichi; Mizoguti, Yasushi; Okada, Takumi

    Magnetic force acting on a model fixed at the center of the JAXA 60cm MSBS was measured with an industry manufactured balance system when MSBS control coil currents were varied. At the same time, magnetic field intensity was also measured with 11 Hall sensors, which were arranged around the MSBS test section. From relations between coil currents and its corresponding controlled magnetic forces, regressive curves were given and maximum deviation from the curves was evaluated. From relations between Hall sensor outputs and the magnetic forces, regressive curves and deviation were also obtained. Obtained results show Hall sensor outputs are much better indexes of balance than the coil currents. The maximum deviations were reduced to a half or one-third times as much as those evaluated using the control coil currents. However, when couples acting on the model are controlled, they are not effective to reduce hysteresis phenomenon in the relation. The deviation can be reduced by decreasing the range of calibration. Then, the error of the balance of the MSBS was reduced to about 1% of the calibration range.

  20. Hall measurements on InAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Bloemers, Christian; Grap, Thomas; Lepsa, Mihail I.; Gruetzmacher, Detlev; Lueth, Hans [Peter Gruenberg Institut (PGI-9), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); Trellenkamp, Stefan [Peter Gruenberg Institut (PGI-8), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); Schaepers, Thomas [Peter Gruenberg Institut (PGI-9), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany); II. Physikalisches Institut, RWTH Aachen, 52074 Aachen (Germany)

    2012-07-01

    In search of novel concepts for the realization of nanoelectronic devices, semiconductor nanowires grown by ''bottom-up'' techniques have shown great promise. Without any doubt, the knowledge about the free carrier concentration n{sub el} is crucial for the fabrication of such devices on the nanometer scale. The most common method to determine n{sub el} in nanowires is to utilize the field effect in a gate measurement setup. However, within this method, uncertainties such as the density of surface states between the nanowire and the dielectric material or the resulting nanowire capacitance influence results. Additionally, source and drain electrodes tend to screen the gate potential in devices of small size. Here we report on Hall measurements on InAs nanowires as an alternative method to determine n{sub el}. By electron beam lithography we are able to fabricate side contacts to single nanowires to realize a Hall-measurement geometry. The side contacts allow us to measure a Hall-voltage, from which we deduce the carrier concentration in the wires.

  1. Quantum anomalous Hall effect in real materials

    Science.gov (United States)

    Zhang, Jiayong; Zhao, Bao; Zhou, Tong; Yang, Zhongqin

    2016-11-01

    Under a strong magnetic field, the quantum Hall (QH) effect can be observed in two-dimensional electronic gas systems. If the quantized Hall conductivity is acquired in a system without the need of an external magnetic field, then it will give rise to a new quantum state, the quantum anomalous Hall (QAH) state. The QAH state is a novel quantum state that is insulating in the bulk but exhibits unique conducting edge states topologically protected from backscattering and holds great potential for applications in low-power-consumption electronics. The realization of the QAH effect in real materials is of great significance. In this paper, we systematically review the theoretical proposals that have been brought forward to realize the QAH effect in various real material systems or structures, including magnetically doped topological insulators, graphene-based systems, silicene-based systems, two-dimensional organometallic frameworks, quantum wells, and functionalized Sb(111) monolayers, etc. Our paper can help our readers to quickly grasp the recent developments in this field. Project supported by the National Basic Research Program of China (Grant No. 2011CB921803), the National Natural Science Foundation of China (Grant No. 11574051), the Natural Science Foundation of Shanghai, China (Grant No. 14ZR1403400), and Fudan High-end Computing Center, China.

  2. Generic superweak chaos induced by Hall effect.

    Science.gov (United States)

    Ben-Harush, Moti; Dana, Itzhack

    2016-05-01

    We introduce and study the "kicked Hall system" (KHS), i.e., charged particles periodically kicked in the presence of uniform magnetic (B) and electric (E) fields that are perpendicular to each other and to the kicking direction. We show that for resonant values of B and E and in the weak-chaos regime of sufficiently small nonintegrability parameter κ (the kicking strength), there exists a generic family of periodic kicking potentials for which the Hall effect from B and E significantly suppresses the weak chaos, replacing it by "superweak" chaos (SWC). This means that the system behaves as if the kicking strength were κ^{2} rather than κ. For E=0, SWC is known to be a classical fingerprint of quantum antiresonance, but it occurs under much less generic conditions, in particular only for very special kicking potentials. Manifestations of SWC are a decrease in the instability of periodic orbits and a narrowing of the chaotic layers, relative to the ordinary weak-chaos case. Also, for global SWC, taking place on an infinite "stochastic web" in phase space, the chaotic diffusion on the web is much slower than the weak-chaos one. Thus, the Hall effect can be relatively stabilizing for small κ. In some special cases, the effect is shown to cause ballistic motion for almost all parameter values. The generic global SWC on stochastic webs in the KHS appears to be the two-dimensional closest analog to the Arnol'd web in higher dimensional systems.

  3. Flying Cities

    DEFF Research Database (Denmark)

    Ciger, Jan

    2006-01-01

    The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property...... of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal performance....... As the feedback we have received when presenting Flying Cities was very positive, our objective now is to cross the bridge between art and the potential applications to the rehabilitation of people with reduced mobility or for the treatment of language impairments....

  4. Soft Cities

    DEFF Research Database (Denmark)

    Brix, Anders; Yoneda, Akira; Nakamura, Kiyoshi

    2015-01-01

    This paper presents a project exploring sustainable ways of urban living. The project renders a scenario comprised of an array of simple conversions of existing urban spaces and buildings, in the attempt to tie strategies ranging from urban planning to interior design into a coherent vision...... of a sustainable future. The project is the result of a joint research study between Denmark and Japan. Taking as its example the city of Kyoto, the project investigates some possible strategies on how cities more generally may be transformed into liveable, healthy and ecologically sensible environments....

  5. Fun City

    DEFF Research Database (Denmark)

    Once the blues guitarist B.B. King sang that when he "didn't wanna live no more", he would go shopping instead. Now, however, shopping has become a lifestyle... The city of today has become "Disneyfied" and "Tivolized". It has become a scene for events. The aim of the book is to encircle and pin...... down the consquences of these developments, to elocidate the interplay between funscapes and fear culture, and to account for the meaning of new concepts and new phenomena such as "event culture", "urban scenography", "experience economy","city branding" and "cultural planning"....

  6. Unhappy Cities

    Science.gov (United States)

    Glaeser, Edward L.; Gottlieb, Joshua D.; Ziv, Oren

    2016-01-01

    There are persistent differences in self-reported subjective well-being across US metropolitan areas, and residents of declining cities appear less happy than others. Yet some people continue to move to these areas, and newer residents appear to be as unhappy as longer-term residents. While historical data on happiness are limited, the available facts suggest that cities that are now declining were also unhappy in their more prosperous past. These facts support the view that individuals do not maximize happiness alone but include it in the utility function along with other arguments. People may trade off happiness against other competing objectives. PMID:27546979

  7. Flying Cities

    DEFF Research Database (Denmark)

    Ciger, Jan

    2006-01-01

    of providing a tangible correspondence between the two spaces. This interaction mean has proved to suit the artistic expression well but it also aims at providing anyone with a pleasant and stimulating feedback from speech activity, a new medium for creativity and a way to visually perceive a vocal performance......The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property...

  8. Antiferromagnetic skyrmion crystals: Generation, topological Hall, and topological spin Hall effect

    Science.gov (United States)

    Göbel, Börge; Mook, Alexander; Henk, Jürgen; Mertig, Ingrid

    2017-08-01

    Skyrmions are topologically nontrivial, magnetic quasiparticles that are characterized by a topological charge. A regular array of skyrmions, a skyrmion crystal (SkX), features the topological Hall effect (THE) of electrons, which, in turn, gives rise to the Hall effect of the skyrmions themselves. It is commonly believed that antiferromagnetic skyrmion crystals (AFM-SkXs) lack both effects. In this Rapid Communication, we present a generally applicable method to create stable AFM-SkXs by growing a two-sublattice SkX onto a collinear antiferromagnet. As an example we show that both types of skyrmion crystals, conventional and antiferromagnetic, exist in honeycomb lattices. While AFM-SkXs with equivalent lattice sites do not show a THE, they exhibit a topological spin Hall effect. On top of this, AFM-SkXs on inequivalent sublattices exhibit a nonzero THE, which may be utilized in spintronics devices. Our theoretical findings call for experimental realization.

  9. Dissipationless spin-Hall current contribution in the extrinsic spin-Hall effect

    Institute of Scientific and Technical Information of China (English)

    Yan Yu-Zhen; Li Hui-Wu; Hu Liang-Bin

    2009-01-01

    This paper shows that a substantial amount of dissipationless spin-Hall current contribution may exist in the extrinsic spin-Hall effect, which originates from the spin-orbit coupling induced by the applied external electric field itself that drives the extrinsic spin-Hall effect in a nonmagnetic semiconductor (or metal). By assuming that the impurity density is in a moderate range such that the total scattering potential due to all randomly distributed impurities is a smooth function of the space coordinate, it is shown that this dissipationless contribution shall be of the same orders of magnitude as the usual extrinsic contribution from spin-orbit dependent impurity scatterings (or may even be larger than the latter one). The theoretical results obtained are in good agreement with recent relevant experimental results.

  10. City 2020+

    Science.gov (United States)

    Schneider, C.; Buttstädt, M.; Merbitz, H.; Sachsen, T.; Ketzler, G.; Michael, S.; Klemme, M.; Dott, W.; Selle, K.; Hofmeister, H.

    2010-09-01

    This research initiative CITY 2020+ assesses the risks and opportunities for residents in urban built environments under projected demographic and climate change for the year 2020 and beyond, using the City of Aachen as a case study. CITY 2020+ develops scenarios, options and tools for planning and developing sustainable future city structures. We investigate how urban environment, political structure and residential behavior can best be adapted, with attention to the interactions among structural, political, and sociological configurations and with their consequences on human health. Demographers project that in the EU-25-States by 2050, approximately 30% of the population will be over age 65. Also by 2050, average tem¬peratures are projected to rise by 1 to 2 K. Combined, Europe can expect enhanced thermal stress and higher levels of particulate matter. CITY 2020+ amongst other sub-projects includes research project dealing with (1) a micro-scale assessment of blockages to low-level cold-air drainage flow into the city centre by vegetation and building structures, (2) a detailed analysis of the change of probability density functions related to the occurrence of heat waves during summer and the spatial and temporal structure of the urban heat island (UHI) (3) a meso-scale analysis of particulate matter (PM) concentrations depending on topography, local meteorological conditions and synoptic-scale weather patterns. First results will be presented specifically from sub-projects related to vegetation barriers within cold air drainage, the assessment of the UHI and the temporal and spatial pattern of PM loadings in the city centre. The analysis of the cold air drainage flow is investigated in two consecutive years with a clearing of vegetation stands in the beginning of the second year early in 2010. The spatial pattern of the UHI and its possible enhancement by climate change is addressed employing a unique setup using GPS devices and temperature probes fixed to

  11. Commemorative Symposium on the Hall Effect and its Applications

    CERN Document Server

    Westgate, C

    1980-01-01

    In 1879, while a graduate student under Henry Rowland at the Physics Department of The Johns Hopkins University, Edwin Herbert Hall discovered what is now universally known as the Hall effect. A symposium was held at The Johns Hopkins University on November 13, 1979 to commemorate the lOOth anniversary of the discovery. Over 170 participants attended the symposium which included eleven in­ vited lectures and three speeches during the luncheon. During the past one hundred years, we have witnessed ever ex­ panding activities in the field of the Hall effect. The Hall effect is now an indispensable tool in the studies of many branches of condensed matter physics, especially in metals, semiconductors, and magnetic solids. Various components (over 200 million!) that utilize the Hall effect have been successfully incorporated into such devices as keyboards, automobile ignitions, gaussmeters, and satellites. This volume attempts to capture the important aspects of the Hall effect and its applications. It includes t...

  12. Sin City?

    NARCIS (Netherlands)

    Gautier, Pieter A.; Svarer, Michael; Teulings, Coen N.

    2007-01-01

    Is moving to the countryside a credible commitment device for couples? We investigate whether lowering the arrival rate of potential alternative partners by moving to a less populated area lowers the dissolution risk for a sample of Danish couples. We find that of the couples who married in the city

  13. Excite City

    DEFF Research Database (Denmark)

    Marling, Gitte; Kiib, Hans; Jensen, Ole B.

    This paper takes its point of departure in the pressure of the experience economy on European cities - a pressure which in recent years has found its expression in a number of comprehensive transformations of the physical and architectural environments, and new eventscapes related to fun and cult...

  14. Vacant city

    NARCIS (Netherlands)

    Marzot, N.

    2013-01-01

    Abandoned places that the crisis has multiplied, unaware wrecks of a project of civilization that has consumed its thrust and life-giving function, are waiting for new desirable interpretations, they are an expression of a possible city in opposition to the existing, even if not recognized by any in

  15. Drone City

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2016-01-01

    This paper address the phenomenon of drones and their potential relationship with the city from the point of view of the so-called “mobilities turn”. This is done in such a way that turns attention to a recent redevelopment of the “turn” towards design; so the emerging perspective of “mobilities...... design” will be used as a background perspective to reflect upon the future of drones in cities. The other perspective used to frame the phenomenon is the emerging discourse of the “smart city”. A city of proliferating digital information and data communication may be termed a smart city as shorthand...... on the block” that will potentially be a game-changer for urban governance, economics and everyday life. Here we are thinking of the unmanned aerial vehicle or drone as the popular term has it. Therefore, the paper asks how life in “drone city” may play out. Drones may alter the notion of surveillance by means...

  16. Sustainable Cities

    DEFF Research Database (Denmark)

    Georg, Susse; Garza de Linde, Gabriela Lucía

    /assessment tool. The context for our study is urban regeneration in one Danish city, which had been suffering from industrial decline and which is currently investing in establishing a “sustainable city”. Based on this case study we explore how the insights and inspiration evoked in working with the tool...

  17. Basic Instrumentation for Hall A at Jefferson Jab

    Energy Technology Data Exchange (ETDEWEB)

    The Jefferson Lab Hall A Collaboration

    2003-07-01

    The instrumentation in Hall A at the JLab was designed to study electro- and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. A collaboration of approximately 50 institutions from all over the world has actively contributed and participated in the design, construction and commissioning of the Hall A instrumentation. The basic Hall A equipment is described herein.

  18. Estimates of Quantities in a Hall Effect Geodynamo Theory

    Directory of Open Access Journals (Sweden)

    Annraoi M de Paor

    2008-01-01

    Full Text Available Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect. It is concluded that the Hall Coefficient in the bulk liquid core of the Earth is approximately 1.512x10-1, orders of magnitude greater than in normal liquid metals. The ordering effect of enormous pressure is a possible cause.

  19. Estimates of quantities in a Hall effect geodynamo theory

    OpenAIRE

    Annraoi M de Paor

    2008-01-01

    Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect. It is concluded that the Hall Coefficient in the bulk liquid core of the Earth is approximately 1.512x10-1, orders of magnitude greater than in normal liquid metals. The ordering effect of enormous pressure is a possible cause.

  20. Charge and Current in the Quantum Hall Matrix Model

    OpenAIRE

    2003-01-01

    We extend the quantum Hall matrix model to include couplings to external electric and magnetic fields. The associated current suffers from matrix ordering ambiguities even at the classical level. We calculate the linear response at low momenta -- this is unambigously defined. In particular, we obtain the correct fractional quantum Hall conductivity, and the expected density modulations in response to a weak and slowly varying magnetic field. These results show that the classical quantum Hall ...

  1. Hall effect in strongly correlated low dimensional systems

    OpenAIRE

    Leon Suros, Gladys Eliana; Berthod, Christophe; Giamarchi, Thierry

    2006-01-01

    We investigate the Hall effect in a quasi one-dimensional system made of weakly coupled Luttinger Liquids at half filling. Using a memory function approach, we compute the Hall coefficient as a function of temperature and frequency in the presence of umklapp scattering. We find a power-law correction to the free-fermion value (band value), with an exponent depending on the Luttinger parameter $K_{\\rho}$. At high enough temperature or frequency the Hall coefficient approaches the band value.

  2. Fabrication of a vector Hall sensor for magnetic microscopy

    Science.gov (United States)

    Gregušová, D.; Cambel, V.; Fedor, J.; Kúdela, R.; Šoltýs, J.; Lalinský, T.; Kostič, I.; Bending, S. J.

    2003-05-01

    We have developed a micromachined Hall sensor for scanning the entire magnetic field vector whose active dimensions are an order of magnitude smaller (˜5 μm) than the smallest existing vector field sensor. It is realized by patterning three Hall probes on the tilted faces of epitaxy-overgrown GaAs-based pyramidal-shaped mesa structures. Data from these "tilted" Hall probes are used to reconstruct the full magnetic field vector.

  3. Quantized Thermal Transport in the Fractional Quantum Hall Effect

    OpenAIRE

    Kane, C. L.; Fisher, Matthew P. A.

    1996-01-01

    We analyze thermal transport in the fractional quantum Hall effect (FQHE), employing a Luttinger liquid model of edge states. Impurity mediated inter-channel scattering events are incorporated in a hydrodynamic description of heat and charge transport. The thermal Hall conductance, $K_H$, is shown to provide a new and universal characterization of the FQHE state, and reveals non-trivial information about the edge structure. The Lorenz ratio between thermal and electrical Hall conductances {\\i...

  4. Pseudospectral Model for Hybrid PIC Hall-effect Thruster Simulation

    Science.gov (United States)

    2015-07-01

    1149. 8Goebel, D. M. and Katz, I., Fundamentals of Electric Propulsion : Ion and Hall Thrusters, John Wiley & Sons, Inc., 2008. 9Martin, R., J.W., K...Bilyeu, D., and Tran, J., “Dynamic Particle Weight Remapping in Hybrid PIC Hall -effect Thruster Simulation,” 34th Int. Electric Propulsion Conf...Paper 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE Pseudospectral model for hybrid PIC Hall -effect thruster simulationect

  5. The Hall module of an exact category with duality

    OpenAIRE

    Young, Matthew B.

    2012-01-01

    We construct from a finitary exact category with duality a module over its Hall algebra, called the Hall module, encoding the first order self-dual extension structure of the category. We study in detail Hall modules arising from the representation theory of a quiver with involution. In this case we show that the Hall module is naturally a module over the specialized reduced sigma-analogue of the quantum Kac-Moody algebra attached to the quiver. For finite type quivers, we explicitly determin...

  6. Dynamic Feedback in Ferromagnet-Spin Hall Metal Heterostructures

    Science.gov (United States)

    Cheng, Ran; Zhu, Jian-Gang; Xiao, Di

    2016-08-01

    In ferromagnet-normal-metal heterostructures, spin pumping and spin-transfer torques are two reciprocal processes that occur concomitantly. Their interplay introduces a dynamic feedback effect interconnecting energy dissipation channels of both magnetization and current. By solving the spin diffusion process in the presence of the spin Hall effect in the normal metal, we show that the dynamic feedback gives rise to (i) a nonlinear magnetic damping that is crucial to sustain uniform steady-state oscillations of a spin Hall oscillator at large angles and (ii) a frequency-dependent spin Hall magnetoimpedance that reduces to the spin Hall magnetoresistance in the dc limit.

  7. Composite particle and field theory in atomic quantum Hall effect

    Institute of Scientific and Technical Information of China (English)

    Zhao Bo; Chen Zeng-Bing

    2005-01-01

    In this paper, we explore the composite particle description of the atomic quantum Hall (QH) effect. We further give the Chern-Simon-Gross-Pitaevskii (CSGP) effective theory for the atomic Hall liquid, which is the counterpart of Chern-Simon theory in electron Hall effect. What we obtained is equivalent to the Laughlin wavefunction approach.Our results show that in terms of composite particles, the atomic Hall effect is really the same as the electronic QH effect. The CSGP effective theory would shed new light on the atomic QH effect.

  8. High Efficiency Hall Thruster Discharge Power Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek leveraged previous, internally sponsored, high power, Hall thruster discharge converter development which allowed it to design, build, and test new printed...

  9. Hall Sensor Output Signal Fault-Detection & Safety Implementation Logic

    Directory of Open Access Journals (Sweden)

    Lee SangHun

    2016-01-01

    Full Text Available Recently BLDC motors have been popular in various industrial applications and electric mobility. Recently BLDC motors have been popular in various industrial applications and electric mobility. In most brushless direct current (BLDC motor drives, there are three hall sensors as a position reference. Low resolution hall effect sensor is popularly used to estimate the rotor position because of its good comprehensive performance such as low cost, high reliability and sufficient precision. Various possible faults may happen in a hall effect sensor. This paper presents a fault-tolerant operation method that allows the control of a BLDC motor with one faulty hall sensor and presents the hall sensor output fault-tolerant control strategy. The situations considered are when the output from a hall sensor stays continuously at low or high levels, or a short-time pulse appears on a hall sensor signal. For fault detection, identification of a faulty signal and generating a substitute signal, this method only needs the information from the hall sensors. There are a few research work on hall effect sensor failure of BLDC motor. The conventional fault diagnosis methods are signal analysis, model based analysis and knowledge based analysis. The proposed method is signal based analysis using a compensation signal for reconfiguration and therefore fault diagnosis can be fast. The proposed method is validated to execute the simulation using PSIM.

  10. Probing magnetic microstructures with quasi-ballistic Hall crosses

    Science.gov (United States)

    Fasbender, S.; Schluck, J.; Cerchez, M.; Heinzel, T.; Sievers, S.; Pierz, K.; Schumacher, H. W.

    2016-03-01

    Hall sensing is performed on a localized magnetic field pattern using a quasi-ballistic Hall cross device. The Hall resistance shows a pronounced peak as a function of the magnetic field amplitude which is absent in the magnetization hysteresis loop. This non-monotonic response exemplifies qualitatively the failure of conventional Hall sensing. It is demonstrated how, by using a numerical simulation based on the Landauer-Büttiker model, the amplitude of the magnetic field profile can be determined from such measurements.

  11. Hall and Nernst effects in monolayer MoS2

    Science.gov (United States)

    Zhang, Yun-Hai; Zhang, Ming-Hua

    2016-03-01

    We study Hall and Nernst transports in monolayer MoS2 based on Green’s function formalism. We have derived analytical results for spin and valley Hall conductivities in the zero temperature and spin and valley Nernst conductivities in the low temperature. We found that tuning of the band gap and spin-orbit splitting can drive system transition from spin Hall insulator (SHI) to valley Hall insulator (VHI). When the system is subjected to a temperature gradient, the spin and valley Nernst conductivities are dependent on Berry curvature.

  12. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    @@ The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are fundamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively.The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.Recent progress on the mechanism of AHE has established a link between the AHE and the topological nature of the Hall current by adopting the Berry-phase concepts in close analogy to the intrinsic spin Hall effect.Given the experimental discovery of the quantum Hall and the quantum spin Hall effects, it is natural to ask whether the AHE can also be quantized.In a quantized anomalous Hall (QAH) insulator, spontaneous magnetic moments and spin-orbit coupling combine to give rise to a topologically non-trivial electronic structure, leading to the quantized Hall effect without any external magnetic field.

  13. MAGNETORESISTANCE AND HALL EFFECT IN SINGLE CRYSTALS OF ALUMINUM

    Science.gov (United States)

    ALUMINUM, *SINGLE CRYSTALS, CRYSTALS, HALL EFFECT , IMPURITIES, LOW PRESSURE, MAGNETIC FIELDS, MAGNETIC PROPERTIES, PARTICLE TRAJECTORIES, ELECTRICAL RESISTANCE, SOLID STATE PHYSICS, SURFACE PROPERTIES.

  14. Laughlin's argument for the quantized thermal Hall effect

    CERN Document Server

    Nakai, Ryota; Nomura, Kentaro

    2016-01-01

    We extend Laughlin's magnetic-flux-threading argument to the quantized thermal Hall effect. A proper analogue of Laughlin's adiabatic magnetic-flux threading process for the case of the thermal Hall effect is given in terms of an external gravitational field. From the perspective of the edge theories of quantum Hall systems, the quantized thermal Hall effect is closely tied to the breakdown of large diffeomorphism invariance, that is, a global gravitational anomaly. In addition, we also give an argument from the bulk perspective in which a free energy, decomposed into its Fourier modes, is adiabatically transferred under an adiabatic process involving external gravitational perturbations.

  15. Modelling the Price of Unleaded Petrol in Australia’s Capital Cities

    Directory of Open Access Journals (Sweden)

    Abbas Valadkhani

    2010-06-01

    Full Text Available This paper examines the long-run and short-run determinants of unleaded petrol price in Australia’s capitalcities using monthly data to find out whether prices respond asymmetrically to external shocks. Based on thecointegration test results and the estimated asymmetric short-run dynamic models, it is found that: (1 in thelong-run petrol prices are mainly determined by Tapis crude oil and Singapore petrol prices; (2 there issome evidence of asymmetric price adjustments in the short-run since petrol price increases have been mostlypassed on to the consumer faster than price decreases in four capital cities. More specifically, this paperprovides convincing evidence in support of asymmetric price adjustments and the “rockets-and-feathershypothesis” in Adelaide, Brisbane, Melbourne and Sydney. One can thus argue that there are a significantdegree of market inefficiency and/or collusion, requiring a closer government price monitoring and scrutiny.

  16. Duality in the quantum Hall system

    Science.gov (United States)

    Lütken, C. A.; Ross, G. G.

    1992-05-01

    We suggest that a unified description of the integer and fractional phases of the quantum Hall system may be possible if the scaling diagram of transport coefficients is invariant under linear fractional (modular) transformations. In this model the hierarchy of states, as well as the observed universality of critical exponents, are consequences of a discrete SL(2,openZ) symmetry acting on the parameter space of an effective quantum-field theory. Available scaling data on the position of delocalization fixed points in the integer case and the position of mobility fixed points in the fractional case agree with the model within experimental accuracy.

  17. Twisted CFT and bilayer Quantum Hall systems

    CERN Document Server

    Cristofano, G; Naddeo, A

    2003-01-01

    We identify the impurity interactions of the recently proposed CFT description of a bilayer Quantum Hall system at filling nu =m/(pm+2) in Mod. Phys. Lett. A 15 (2000) 1679. Such a CFT is obtained by m-reduction on the one layer system, with a resulting pairing symmetry and presence of quasi-holes. For the m=2 case boundary terms are shown to describe an impurity interaction which allows for a localized tunnel of the Kondo problem type. The presence of an anomalous fixed point is evidenced at finite coupling which is unstable with respect to unbalance and flows to a vacuum state with no quasi-holes.

  18. Hypernuclear spectroscopy program at JLab Hall C

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Osamu; Hashimoto, Osamu; Nakamura, Satoshi; Acha Quimper, Armando; Ahmidouch, Abdellah; Androic, Darko; Asaturyan, Arshak; Asaturyan, Razmik; Baker, O.; Baturin, Pavlo; Benmokhtar, Fatiha; Bosted, Peter; Carlini, Roger; Chen, X.; Christy, Michael; Cole, Leon; Danagoulian, Samuel; Daniel, AJI; Dharmawardane, Kahanawita; Egiyan, Kim; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gan, Liping; Gaskell, David; Gasparian, Ashot; Gibson, Edward; Gueye, Paul; Halkyard, Rebekah; Honda, D.; Horn, Tanja; Hu, Bitao; Hu, S.; Hungerford, Ed; Ispiryan, Mikayel; Johnston, Kathleen; Jones, Mark; Kalantarians, Narbe; Kaneta, M.; Kato, F.; Kato, Seigo; Kawama, Daisuke; Keppel, Cynthia; Li, Ya; Luo, Wei; Mack, David; Margaryan, Amur; Marikyan, Gagik; Maruyama, Nayuta; Matsumura, Akihiko; Miyoshi, Toshinobu; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Navasardyan, Tigran; Niculescu, Gabriel; Niculescu, Maria-Ioana; Nomura, Hiroshi; Nonaka, Kenichi; Ohtani, Atsushi; Okayasu, Yuichi; Pamela, Priscilla; Perez, Naipy; Petkovic, Tomislav; Randeniya, Kapugodage; Reinhold, Joerg; Rivera Castillo, Roberto; Roche, Julie; Rodriguez, Victor; Sato, Yoshinori; Seva, Tomislav; Tang, Liguang; Simicevic, Neven; Smith, Gregory; Sumihama, Mizuki; Song, Y.; Tadevosyan, Vardan; Takahashi, Toshiyuki; Tamura, Hirokazu; Tvaskis, Vladas; Vulcan, William; Wang, B.; Wells, Steven; Yan, Chen; Yuan, Lulin; Zamkochian, S.

    2008-05-01

    DOI: http://dx.doi.org/10.1016/j.nuclphysa.2008.01.029
    Hypernuclear production by the (e,e?K+) reaction has unique advantages in hypernuclear spectroscopy of the S=?1 regime. The second-generation spectroscopy experiment on 12C, 7Li and 28Si targets has been recently carried out at JLab Hall C with a new experimental configuration (Tilt method) and also using a new high-resolution kaon spectrometer (HKS). The experiment is described and preliminary results are presented together with the empasis of significance of the (e,e?K+) reaction for ? hypernuclear spectroscopy and its future prospects.

  19. Current correlations in quantum spin Hall insulators.

    Science.gov (United States)

    Schmidt, Thomas L

    2011-08-26

    We consider a four-terminal setup of a two-dimensional topological insulator (quantum spin Hall insulator) with local tunneling between the upper and lower edges. The edge modes are modeled as helical Luttinger liquids and the electron-electron interactions are taken into account exactly. Using perturbation theory in the tunneling, we derive the cumulant generating function for the interedge current. We show that different possible transport channels give rise to different signatures in the current noise and current cross correlations, which could be exploited in experiments to elucidate the interplay between electron-electron interactions and the helical nature of the edge states.

  20. Anomalous Hall Effect in a Kagome Ferromagnet

    Science.gov (United States)

    Ye, Linda; Wicker, Christina; Suzuki, Takehito; Checkelsky, Joseph; Joseph Checkelsky Team

    The ferromagnetic kagome lattice is theoretically known to possess topological band structures. We have synthesized large single crystals of a kagome ferromagnet Fe3Sn2 which orders ferromagnetically well above room temperature. We have studied the electrical and magnetic properties of these crystals over a broad temperature and magnetic field range. Both the scaling relation of anomalous Hall effect and anisotropic magnetic susceptibility show that the ferromagnetism of Fe3Sn2 is unconventional. We discuss these results in the context of magnetism in kagome systems and relevance to the predicted topological properties in this class of compounds. This research is supported by DMR-1231319.

  1. Supercurrent in the quantum Hall regime

    Science.gov (United States)

    Amet, F.; Ke, C. T.; Borzenets, I. V.; Wang, J.; Watanabe, K.; Taniguchi, T.; Deacon, R. S.; Yamamoto, M.; Bomze, Y.; Tarucha, S.; Finkelstein, G.

    2016-05-01

    A promising route for creating topological states and excitations is to combine superconductivity and the quantum Hall (QH) effect. Despite this potential, signatures of superconductivity in the QH regime remain scarce, and a superconducting current through a QH weak link has been challenging to observe. We demonstrate the existence of a distinct supercurrent mechanism in encapsulated graphene samples contacted by superconducting electrodes, in magnetic fields as high as 2 tesla. The observation of a supercurrent in the QH regime marks an important step in the quest for exotic topological excitations, such as Majorana fermions and parafermions, which may find applications in fault-tolerant quantum computing.

  2. Novel optical probe for quantum Hall system

    Indian Academy of Sciences (India)

    Biswajit Karmakar; Brij Mohan Arora

    2006-07-01

    Surface photovoltage (SPV) spectroscopy has been used for the first time to explore Landau levels of a two-dimensional electron gas (2DEG) in modulation doped InP/InGaAs/InP QW in the quantum Hall regime. The technique gives spectroscopically distinct signals from the bulk Landau levels and the edge states. Evolution of the bulk Landau levels and the edge electronic states is investigated at 2.0 K for magnetic field up to 8 T using SPV spectroscopy.

  3. Excitons in the Fractional Quantum Hall Effect

    Science.gov (United States)

    Laughlin, R. B.

    1984-09-01

    Quasiparticles of charge 1/m in the Fractional Quantum Hall Effect form excitons, which are collective excitations physically similar to the transverse magnetoplasma oscillations of a Wigner crystal. A variational exciton wavefunction which shows explicitly that the magnetic length is effectively longer for quasiparticles than for electrons is proposed. This wavefunction is used to estimate the dispersion relation of these excitons and the matrix elements to generate them optically out of the ground state. These quantities are then used to describe a type of nonlinear conductivity which may occur in these systems when they are relatively clean.

  4. Anesthetic considerations in Sheldon-Hall syndrome.

    Science.gov (United States)

    Anderson, Thomas Anthony; Kasser, James R; Holzman, Robert S

    2014-05-01

    Arthrogryposis is characterized by multiple, nonprogressive joint contractures which may be caused by maternal disorders such as oligohydramnios as well as fetal akinesia resulting from primary disorders of muscle, connective tissue, or neurologic tissue. Its prevalence is about 1 : 3000. Distal arthrogryposis (DA) is a heterogenous group of genetic disorders with a characteristic flexion of the joints of the hands and feet divided into different types with additional features. Sheldon-Hall Syndrome (SHS), also known as distal arthrogryposis type 2A (DA2A), has some nonorthopedic features of specific importance to anesthetic care.

  5. A pilot investigation into associations between indoor airborne fungal and non-biological particle concentrations in residential houses in Brisbane, Australia.

    Science.gov (United States)

    Hargreaves, Megan; Parappukkaran, Sandhya; Morawska, Lidia; Hitchins, Jane; He, Congrong; Gilbert, Dale

    2003-08-01

    Indoor air contains a complex mixture of bioaerosols such as fungi, bacteria and allergens, as well as non-biological particles including products from various combustion processes. To date little work has been done to investigate the interactions and associations between particles of biological and non-biological origin, however, any occurring interactions could affect pollutant behaviour in the air and ultimately the effect they have on health. The aim of this work was to examine associations between the concentration levels of airborne particles and fungi measured in 14 residential suburban houses in Brisbane. The most frequently isolated fungal genus was Cladosporium, Curvularia, Alternaria, Fusarium and Penicillium. The average outdoor and indoor (living room) concentrations of fungal colony forming units were 1133+/-759 and 810+/-389, respectively. Average outdoor and indoor (normal ventilation) concentrations of submicrometre and supermicrometre particles were 23.8 x 10(3) and 21.7 x 10(3) (particles/cm(3)), 1.78 and 1.74 (particles/cm(3)), respectively. The study showed that no statistically significant associations between the fungal spore and submicrometre particle concentrations or PM(2.5) were present, while a weak but statistically significant relationship was found between fungal and supermicrometre particle concentrations (for the outdoors R(2)=0.4, P=0.03 and for a living room R(2)=0.3, P=0.04). A similarity in behaviour between the submicrometre particle and fungal spore concentrations was that the fungal spore concentrations were related directly to the distance from the source (a nearby park), in a very similar way in which the submicrometre particles originating from vehicle emissions from a road, were dependent on the distance to the road. In the immediate proximity to the park, fungal concentrations rose up to approximately 3100 CFU/m(3), whereas for houses more than 150 m away from the park the concentrations of fungi were below 1000 CFU/m(3

  6. Upper airway viruses and bacteria in urban Aboriginal and Torres Strait Islander children in Brisbane, Australia: a cross-sectional study.

    Science.gov (United States)

    O'Grady, Kerry-Ann F; Hall, Kerry K; Sloots, Theo P; Anderson, Jennie; Chang, Anne B

    2017-04-04

    Respiratory morbidity in Australian Indigenous children is higher than their non-Indigenous counterparts, irrespective of urban or remote residence. There are limited studies addressing acute respiratory illness (ARI) in urban Indigenous children, particularly those that address the upper airway microbiome and its relationship to disease. We aimed to describe the prevalence of upper airway viruses and bacteria in symptomatic and asymptomatic urban-based Australian Indigenous children aged less than 5 years. A cross-sectional analysis of data collected at baseline in an ongoing prospective cohort study of urban Aboriginal and Torres Strait Islander children registered with a primary health care service in the northern suburbs of Brisbane, Australia. Clinical, demographic and epidemiological data and bilateral anterior nasal swabs were collected on enrolment. Polymerase chain reaction was performed on nasal swabs to detect 17 respiratory viruses and 7 bacteria. The primary outcome was the prevalence of these microbes at enrolment. Logistic regression was performed to investigate differences in microbe prevalence between children with and without acute respiratory illness with cough as a symptom (ARIwC) at time of specimen collection. Between February 2013 and October 2015, 164 children were enrolled. The median age at enrolment was 18.0 months (IQR 7.2-34.3), 49.4% were boys and 56 children (34.2%) had ARIwC. Overall, 133/164 (81%) nasal swabs were positive for at least one organism; 131 (79.9%) for any bacteria, 59 (36.2%) for any virus and 57 (34.8%) for both viruses and bacteria. Co-detection of viruses and bacteria was more common in females than males (61.4% vs 38.6%, p = 0.044). No microbes, alone or in combination, were significantly associated with the presence of ARIwC. The prevalence of upper airways microbes in asymptomatic children is similar to non-Indigenous children with ARIwC from the same region. Determining the aetiology of ARIwC in this

  7. Effect of Joule heating on current-induced asymmetries and breakdown of the quantum Hall effect in narrow Hall bars

    Science.gov (United States)

    Gerhardts, Rolf R.

    2017-01-01

    Recent low-temperature scanning-force-microscopy experiments on narrow Hall bars, under the conditions of the integer quantum Hall effect (IQHE) and its breakdown, have revealed an interesting position dependence of the Hall potential, which changes drastically with the applied magnetic field and the strength of the imposed current through the sample. The present paper shows, that inclusion of Joule heating into an existing self-consistent theory of screening and magneto-transport, which assumes translation invariant Hall bars with a homogeneous background charge due to doping, can explain the experimental results on the breakdown of the IQHE in the so called edge-dominated regime.

  8. Sustainable Cities

    DEFF Research Database (Denmark)

    Georg, Susse; Garza de Linde, Gabriela Lucía

    Judging from the number of communities and cities striving or claiming to be sustainable and how often eco-development is invoked as the means for urban regeneration, it appears that sustainable and eco-development have become “the leading paradigm within urban development” (Whitehead 2003......), urban design competitions are understudied mechanisms for bringing about field level changes. Drawing on actor network theory, this paper examines how urban design competitions may bring about changes within the professional field through the use of intermediaries such as a sustainable planning....../assessment tool. The context for our study is urban regeneration in one Danish city, which had been suffering from industrial decline and which is currently investing in establishing a “sustainable city”. Based on this case study we explore how the insights and inspiration evoked in working with the tool...

  9. Sharing City

    DEFF Research Database (Denmark)

    This magazine offers an insight into the growing commercial innovation, civic movements, and political narratives surrounding sharing economy services, solutions and organisational types. It presents a cross-section of the manifold sharing economy services and solutions that can be found in Denmark....... Solutions of sharing that seeks to improve our cities and local communities in both urban and rural environments. 24 sharing economy organisations and businesses addressing urban and rural issues are being portrayed and seven Danish municipalities that have explored the potentials of sharing economy....... Moreover, 15 thought leading experts - professionals and academic - have been invited to give their perspective on sharing economy for cities. This magazine touches upon aspects of the sharing economy as mobility, communities, sustainability, business development, mobility, and urban-rural relation....

  10. Analysis on the Construction of Rural Culture Hall in the New Period%新时期农村文化礼堂建设工作探析

    Institute of Scientific and Technical Information of China (English)

    陈磊; 华东杰

    2015-01-01

    This paper introduces the overall conditions of the construction of rural cultural hall in Chayuan Town,Ninghai County,Ningbo City,analyzes some problems existing in the construction of the rural cultural hall,and puts forward some corresponding suggestions and countermeasures for how to better construct the rural cultural hall.%介绍了宁波市宁海县茶院乡农村文化礼堂建设总体情况,分析了农村文化礼堂建设中存在的问题,并就新时期如何更好地建设农村文化礼堂提出了相应的建议与对策.

  11. Intrinsic valley Hall effect in graphene

    Science.gov (United States)

    Yang, Mou; Zhang, Wen-Lian; Liu, Hai; Bai, Yan-Kui

    2017-04-01

    If electrons are incident from an armchair graphene ribbon into the bulk graphene region, the electronic diffraction occurs. Because of the different triangular wrapping of the energy dispersion between valleys K and K ‧ , the electrons of valley K tend to be diffracted to one side and those of valley K ‧ to the other side. When the current is injected from the armchair ribbon of a four-terminal graphene device, the major portion of the incident current of valley K flows through one side arm and the minor portion through the other side arm. The ratio between them is derived to be 1 + 4 E / 3 in the low energy limit, where E is the energy in units of hopping parameter. The major arm for valley K is the minor arm for valley K ‧ . This results in the rise of the valley Hall effect, which is an intrinsic property of graphene stemming from the different electronic structure of the two valleys. The valley Hall conductance is calculated to be (2 E / 3)G0 with G0 being the conductance supported by the injection ribbon.

  12. Repurposing the Caltech Robinson Hall Coelostat

    Science.gov (United States)

    Treffers, Richard R.; Loisos, G.; Ubbelohde, M.; Douglas, S.; Martinez, M.

    2013-01-01

    We describe the repurposing of the historic coelostat atop Caltech’s Robinson Hall for building lighting, public education and scientific research. The coelostat was originally part of George Ellery Hale’s vision of the Astrophysical Laboratory on the Caltech campus in 1932. The coelostat, designed by Russell Porter, has a 36 inch diameter primary mirror a 30 inch diameter secondary mirror and provides a 24 inch un-vignetted beam of sunlight into the building. Although constructed in the 1930s, due to wartime pressures and other projects, it was used only briefly in the 1970s and never fully realized. Recently Robinson Hall has been fully renovated to house the Ronald and Maxine Linde Center for Global Environmental Science. The coelostat operation was modernized replacing the old motors and automating all the motions. Each morning, if the weather cooperates, the dome slit opens, the mirrors configured and sunlight pours into the building. The beam of sunlight is divided into three parts. One part goes into a refracting telescope which projects a ten inch diameter of the sun onto a ground glass screen visible to the public. A second fraction is distributed to fiber optic fixtures that illuminate some of the basement rooms. The final fraction goes into two laboratories where it is used in experiments monitoring trace constituents of our atmosphere and for solar catalysis experiments. The instrument as originally conceived required at least two human operators. Now it is fully automatic and doing real science

  13. Plume Comparisons between Segmented Channel Hall Thrusters

    Science.gov (United States)

    Niemack, Michael; Staack, David; Raitses, Yevgeny; Fisch, Nathaniel

    2001-10-01

    Angular ion flux plume measurements were taken in several configurations of segmented channel Hall thrusters. The configurations differed by the placement of relatively short rings made from materials with different conductive and secondary electron emission properties along the boron nitride ceramic channel of the thrusters (these have been shown to affect the plume [1]). The ion fluxes are compared with ion trajectory simulations based on plasma potential data acquired with a high speed emissive probe [2]. Preliminary results indicate that in addition to the physical properties of the segments, the plume angle can be strongly affected by the placement of segmented rings relative to the external and internal walls of the channel. [1] Y. Raitses, L. Dorf, A. Litvak and N. J. Fisch, Journal of Applied Physics 88, 1263, 2000 [2] D. Staack, Y. Raitses, N. J. Fisch, Parametric Investigations of Langmuir Probe Induced Perturbations in a Hall Thruster, DPP01 Poster Presentation This work was supported by the U.S. DOE Contract No. DE-ACO2-76-CHO3073.

  14. 阿房宫前殿遗址的考古勘探与发掘%ARCHAEOLOGICAL PROSPECTION AND EXCAVATION OF THE ANTERIOR HALL SITE OF THE EPANGGONG PALACE

    Institute of Scientific and Technical Information of China (English)

    李毓芳; 孙福喜; 王自力; 张建锋

    2005-01-01

    The Epanggong Palace site of Qin period lies to the south of the Weihe River and to the west of the old Zaohe River course that extends 13 km west of Xi'an City. It stands opposite to the Qin capital Xianyang across the river. From October 2002 to December 2004, the Epanggong Palace Archaeological Team made a prospection on the anterior hall site,covering :350, 000 sq m, and revealed an area of 3, 000 sq m by trial and extensive excavations. The results include a rough understanding of the limits of the hall and the layout of its auxiliary buildings. It can be confirmed that the rammed earth foundations of the hall represents just the anterior hall of that of the Qin Epanggong Palace. What merits special notice is that there are no fire traces on the site of the anterior hall of the Qin Epanggong Palace, which forms a clear contrast to the archaeologically excavated Nos. 1-3 palaces in the Qin capital Xianyang that were destroyed by a great fire. Thus the excavations prove that the historically handed-down belief taking the Qin Epanggong Palace to have been fired by Xiang Yu is actually incorrect. There are no any building remains on the excavated hall foundations, which demonstrate that the anterior hall was not completed and that the Qin Epanggong Palace was destroyed not by fire。

  15. Radiation heating in sports halls. Stralingsverwarming in sporthallen

    Energy Technology Data Exchange (ETDEWEB)

    Blokpoel, L.

    1994-03-01

    The aim of the study on the title subject was to determine whether by means of the application of radiation heating the required level of thermal comfort in sporting halls can be realized and how much energy is needed to realize such comfort. In two sporting halls the air heating installation was replaced by a radiant heating system. In the sports hall 'D'n Treffer' in Maasbree, Netherlands, infrared radiators were installed, and in the sports hall 'de Taxandriahal' in Waalwijk, Netherlands, so-called dark radiators were installed. After a brief introduction on how to define and quantify thermal comfort, measured results for both sporting halls are presented and discussed. Also the results of a survey among the users of the sporting halls to determine their opinion on the thermal comfort in the halls are presented. The survey was carried out by the authority that commissioned this study, The Dutch National Sports Federation (NSF). In general it can be concluded that radiation heating is a well applicable heating system for sports halls. 17 figs., 8 ills., 10 tabs., 8 appendices

  16. A Larger Scale. Tenth Annual Residence Hall Construction Report.

    Science.gov (United States)

    Argon, Joe

    1999-01-01

    Presents data from the American School & University's 10th Annual Residence Hall Construction Report that show dormitories are costing more per square foot to build while also becoming larger accommodations. Data tables are provided as are highlighted discussions that include residence hall design flexibility, environmental concerns and building…

  17. Stuart Hall on Racism and the Importance of Diasporic Thinking

    Science.gov (United States)

    Rizvi, Fazal

    2015-01-01

    In this article, I want to show how my initial encounter with the work of Stuart Hall was grounded in my reading of the later philosophy of Ludwig Wittgenstein, and was shaped by my interest in understanding the nature of racism across the three countries in which I had lived. Over the years, Hall's various writings have helped me to make sense of…

  18. Acoustic investigations of concert halls for rock music

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2007-01-01

    Objective measurement data and subjective evaluations have been collected from 20 small-/medium-sized halls in Denmark used for amplified rhythmic music concerts (pop, rock, jazz). The purpose of the study was to obtain knowledge about optimum acoustic conditions for this type of hall. The study...

  19. Cultural Composition: Stuart Hall on Ethnicity and the Discursive Turn.

    Science.gov (United States)

    Drew, Julie

    1998-01-01

    Interviews Stuart Hall, a black public intellectual and an activist of the New Left. Discusses the growing disillusionment with cultural studies now that it is no longer in its ascendancy; the proliferation of pedagogical practices given a cultural studies tag; Hall's approval of the use of popular culture in the composition classroom; and the…

  20. Stuart Hall on Racism and the Importance of Diasporic Thinking

    Science.gov (United States)

    Rizvi, Fazal

    2015-01-01

    In this article, I want to show how my initial encounter with the work of Stuart Hall was grounded in my reading of the later philosophy of Ludwig Wittgenstein, and was shaped by my interest in understanding the nature of racism across the three countries in which I had lived. Over the years, Hall's various writings have helped me to make sense of…

  1. Pair spectrometer hodoscope for Hall D at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, F.; Hutton, C.; Sitnikov, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Somov, A., E-mail: somov@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Somov, S.; Tolstukhin, I. [National Research Nuclear University MEPhI, Moscow (Russian Federation)

    2015-09-21

    We present the design of the pair spectrometer hodoscope fabricated at Jefferson Lab and installed in the experimental Hall D. The hodoscope consists of thin scintillator tiles; the light from each tile is collected using wave-length shifting fibers and detected using a Hamamatsu silicon photomultiplier. Light collection was measured using relativistic electrons produced in the tagger area of the experimental Hall B.

  2. Varsity Hall: The Infirmary at the University of Virginia

    Science.gov (United States)

    Christmas, William A.; Turner, James C.

    2008-01-01

    In the past 5 years, an important treasure for the field of college health was rediscovered and has been completely renovated. It is the original student infirmary, now called Varsity Hall, at the University of Virginia in Charlottesville. Varsity Hall is a significant rediscovery for those who are interested in the history of college health. This…

  3. Useful Pedagogical Applications of the Classical Hall Effect

    Science.gov (United States)

    Houari, Ahmed

    2007-01-01

    One of the most known phenomena in physics is the Hall effect. This is mainly due to its simplicity and to the wide range of its theoretical and practical applications. To complete the pedagogical utility of the Hall effect in physics teaching, I will apply it here to determine the Faraday constant as a fundamental physical number and the number…

  4. Spatial sensitivity mapping of Hall crosses using patterned magnetic nanostructures

    NARCIS (Netherlands)

    Alexandrou, M.; Nutter, P.W.; Delalande, M.Y.; Vries, de J.; Hill, E.W.; Schedin, F.; Abelmann, L.; Thomson, T.

    2010-01-01

    Obtaining an accurate profile of the spatial sensitivity of Hall cross structures is crucial if such devices are to be used to analyze the switching behavior of magnetic nanostructures and determine the switching field distribution of bit patterned media. Here, we have used the anomalous Hall effect

  5. Bulk Versus Edge in the Quantum Hall Effect

    OpenAIRE

    Kao, Y. -C.; Lee, D.-H.

    1996-01-01

    The manifestation of the bulk quantum Hall effect on edge is the chiral anomaly. The chiral anomaly {\\it is} the underlying principle of the ``edge approach'' of quantum Hall effect. In that approach, $\\sxy$ should not be taken as the conductance derived from the space-local current-current correlation function of the pure one-dimensional edge problem.

  6. Efecto Hall del In en Película Evaporada

    OpenAIRE

    Herrera de Camboa, María Elena

    2015-01-01

    El efecto Hall demostrado por Edwin Herbert Hall (1) en 1879 ha venido a ser un hecho importante para la comprension del coruportamiento de los portadores de carga en la conduccion electrica. Es por esto que es necesario investigar este fenomeno en Ia Física del Estado Solido en los diferentes solidos.

  7. Energy and the city

    Directory of Open Access Journals (Sweden)

    Francesco Martinico

    2017-06-01

    Africa (MENA countries will face stronger heat waves in the near future (Fischer and Schär, 2001. Their cities, often poorly planned for decades, will be considerably affected by these temperature upsurges.A further complexity arises from the fact that the energy approach in land use plans is not direct. Including energy considerations in urban and regional planning is hardly a technological issue. On the contrary, it requires a deep change in the mind-set of urban planners that have to think at the whole city structure wearing the new “energy glasses”.It is possible to trace the energy issue in land use planning back to its history. Spatial planning has a long lasting tradition in defining the shape of urban fabric and the layout of buildings, taking into account the role of the sun and the wind. This tradition has evolved from the seminal experiences of modernist planning to the new sustainable districts, recently developed in several countries like Germany, the Netherlands, France and Sweden,  including the ones described by Peter Hall (2014 in his last book.But Mediterranean countries have an even longer tradition in building cities and houses that were capable of facing hot temperatures, without any of the electric appliances that are consuming now a considerable share of energy. As part of this long-established tradition, it is worth remembering the inspiring contribution of the Egyptian architect Hassan Fathy. Looking back at the city history is not a mere exercise based on nostalgia. Making greener Mediterranean cities, as they were up to a recent past, is a complex task but it will become unavoidable in order to guarantee forms of sustainable cooling.This is especially true in those cities that have grown considerably in the second half of the 20th century, according to high-density models.Urban planning has been also concerned with defining the proper mix of land uses, taking into account the key role of transports. Compact and walkable cites, rich of

  8. Birmingham-Britain’s Second Largest City

    Institute of Scientific and Technical Information of China (English)

    汪伦

    2009-01-01

    Surrounded by several motorways, separated by canals and with many modem shopping centres, Birmingham seems like a huge maze (迷宫). (1) Best to.set your bearings on the great Council House 19th-century buildings which is located in the heart of town. This area consists of Victoria and Chamberlain Squares, which are the most attractive architecture in the city. To the west are Centenary Square, the International Convention Centre and Symphony Hall, as well as the popular bars and cafes. To the northwest is the colourful Jewellery Quarter. In the southeast of the area are the Pallasades and Pavilions shopping centres and the City Plaza.

  9. Fractional quantum Hall states of bosons on cones

    Science.gov (United States)

    Wu, Ying-Hai; Tu, Hong-Hao; Sreejith, G. J.

    2017-09-01

    Motivated by a recent experiment, which synthesizes Landau levels for photons on cones [Schine et al., Nature (London) 534, 671 (2016), 10.1038/nature17943], and more generally the interest in understanding gravitational responses of quantum Hall states, we study fractional quantum Hall states of bosons on cones. A variety of trial wave functions for conical systems are constructed and compared with exact diagonalization results. The tip of a cone is a localized geometrical defect with singular curvature, which can modify the density profiles of quantum Hall states. The density profiles on cones can be used to extract some universal information about quantum Hall states. The values of certain quantities are computed numerically using the density profiles of some quantum Hall states and they agree with analytical predictions.

  10. Construction and Operation of a Differential Hall Element Magnetometer

    Science.gov (United States)

    Calkins, Matthew W.; Javernick, Philip D.; Quintero, Pedro A.; Calm, Yitzi M.; Meisel, Mark W.

    2012-02-01

    A Differential Hall Element Magnetometer (DHEM) was constructed to measure the magnetic saturation and coercive fields of small samples consisting of magnetic nanoparticles that may have biomedical applications. The device consists of two matched Hall elements that can be moved through the room temperature bore of a 9 Tesla superconducting magnet. The Hall elements are wired in opposition such that a null response, to within a small offset, is measured in the absence of a sample that may be located on top of one unit. A LabVIEW program controls the current through the Hall elements and measures the net Hall voltage while simultaneously moving the probe through the magnetic field by regulating a linear stepper motor. Ultimately, the system will be tested to obtain a figure of merit using successively smaller samples. Details of the apparatus will be provided along with preliminary data.

  11. Topological insulator in junction with ferromagnets: Quantum Hall effects

    Science.gov (United States)

    Chudnovskiy, A. L.; Kagalovsky, V.

    2015-06-01

    The ferromagnet-topological insulator-ferromagnet (FM-TI-FM) junction exhibits thermal and electrical quantum Hall effects. The generated Hall voltage and transverse temperature gradient can be controlled by the directions of magnetizations in the FM leads, which inspires the use of FM-TI-FM junctions as electrical and as heat switches in spintronic devices. Thermal and electrical Hall coefficients are calculated as functions of the magnetization directions in ferromagnets and the spin-relaxation time in TI. Both the Hall voltage and the transverse temperature gradient decrease but are not completely suppressed even at very short spin-relaxation times. The Hall coefficients turn out to be independent of the spin-relaxation time for symmetric configuration of FM leads.

  12. Quantum Hall effect in kagome lattices under staggered magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhiyong, E-mail: zyzhang@nju.edu.cn [Department of Physics, Nanjing University, Nanjing 210093 (China)

    2011-10-26

    The interplay of staggered magnetic field (SMF) and uniform magnetic field (UMF) on the quantum Hall effect (QHE) in kagome lattices is investigated in the weak UMF limit. The topological band gaps coming from SMF are robust against UMF although the extended bands split into a series of Landau levels. With SMF applied, in the unconventional QHE region, one plateau of Hall conductance becomes wider and the others are compressed. Meanwhile, one of the two series of integer Hall plateaus splits and the resulting two series of Hall plateaus still exhibit the integer behavior. The Hall conductance varies with SMF step by step with the step height being e{sup 2}/h or 2e{sup 2}/h according to the QHE being conventional or unconventional. In the transitional regions, redistribution of Chern numbers happens even in the weak UMF limit. (paper)

  13. Unconventional quantum Hall effect in Floquet topological insulators

    KAUST Repository

    Tahir, M.

    2016-07-27

    We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the lights polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity αyx = 0 at zero Fermi energy, to a Hall insulator state with αyx = e2/2h. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at (±1/2,±3/2,±5/2, ...)e2/h. © 2016 IOP Publishing Ltd Printed in the UK.

  14. Axisymmetric Nonlinear Waves And Structures in Hall Plasmas

    CERN Document Server

    Islam, Tanim

    2011-01-01

    A Hall plasma consists of a plasma with not all species frozen into the magnetic field. In this paper, a general equation for the evolution of an axisymmetric magnetic field in a Hall plasma is derived, with an integral similar to the Grad-Shafranov equation. Special solutions arising from curvature -- whistler drift modes that propagate along the electron drift as a Burger's shock, and nonlinear periodic and soliton-like solutions to the generalized Grad-Shafranov integral -- are analyzed. We derive analytical and numerical solutions in an electron-ion Hall plasma, in which electrons and ions are the only species in the plasmas. Results may then be applied to electron-ion-gas Hall plasmas, in which the ions are coupled to the motion of gases in low ionized plasmas (lower ionosphere and protostellar disks), and to dusty Hall plasmas (such as molecular clouds), in which the much heavier charged dust may be collisionally coupled to the gas.

  15. Experimental evidence for a two-dimensional quantized Hall insulator

    Science.gov (United States)

    Hilke, M.; Shahar, D.; Song, S. H.; Tsui, D. C.; Xie, Y. H.; Monroe, Don

    1998-10-01

    The general theoretical definition of an insulator is a material in which the conductivity vanishes at the absolute zero of temperature. In classical insulators, such as materials with a band gap, vanishing conductivities lead to diverging resistivities. But other insulators can show more complex behaviour, particularly in the presence of a high magnetic field, where different components of the resistivity tensor can display different behaviours: the magnetoresistance diverges as the temperature approaches absolute zero, but the transverse (Hall) resistance remains finite. Such a system is known as a Hall insulator. Here we report experimental evidence for a quantized Hall insulator in a two-dimensional electron system-confined in a semiconductor quantum well. The Hall resistance is quantized in the quantum unit of resistance h/e2, where h is Planck's constant and e the electronic charge. At low fields, the sample reverts to being a normal Hall insulator.

  16. Geometric spin Hall effect of light with inhomogeneous polarization

    Science.gov (United States)

    Ling, Xiaohui; Zhou, Xinxing; Yi, Xunong

    2017-01-01

    The spin Hall effect of light originates from spin-orbit interaction of light, which manifests two types of geometric phases. In this paper, we report the observation of a geometric spin Hall effect by generating a light beam with inhomogeneous polarization distribution. Unlike the previously reported geometric spin Hall effect observed in a tilted beam-detector system, which is believed to result from an effective spin-redirection Berry geometric phase, the geometric spin Hall effect demonstrated here is attributed to an effective, spatially varying Pancharatnam-Berry geometric phase generated by the inhomogeneous polarization geometry. Our further experiments show that the geometric spin Hall effect can be tuned by tailoring the polarization geometry of light, demonstrating the spin states of photons can be steered with a great flexibility.

  17. In-plane magnetization-induced quantum anomalous Hall effect.

    Science.gov (United States)

    Liu, Xin; Hsu, Hsiu-Chuan; Liu, Chao-Xing

    2013-08-23

    The quantum Hall effect can only be induced by an out-of-plane magnetic field for two-dimensional electron gases, and similarly, the quantum anomalous Hall effect has also usually been considered for systems with only out-of-plane magnetization. In the present work, we predict that the quantum anomalous Hall effect can be induced by in-plane magnetization that is not accompanied by any out-of-plane magnetic field. Two realistic two-dimensional systems, Bi2Te3 thin film with magnetic doping and HgMnTe quantum wells with shear strains, are presented and the general condition for the in-plane magnetization-induced quantum anomalous Hall effect is discussed based on the symmetry analysis. Nonetheless, an experimental setup is proposed to confirm this effect, the observation of which will pave the way to search for the quantum anomalous Hall effect in a wider range of materials.

  18. Unconventional quantum Hall effect in Floquet topological insulators.

    Science.gov (United States)

    Tahir, M; Vasilopoulos, P; Schwingenschlögl, U

    2016-09-28

    We study an unconventional quantum Hall effect for the surface states of ultrathin Floquet topological insulators in a perpendicular magnetic field. The resulting band structure is modified by photon dressing and the topological property is governed by the low-energy dynamics of a single surface. An exchange of symmetric and antisymmetric surface states occurs by reversing the light's polarization. We find a novel quantum Hall state in which the zeroth Landau level undergoes a phase transition from a trivial insulator state, with Hall conductivity [Formula: see text] at zero Fermi energy, to a Hall insulator state with [Formula: see text]. These findings open new possibilities for experimentally realizing nontrivial quantum states and unusual quantum Hall plateaus at [Formula: see text].

  19. Formulation of the Relativistic Quantum Hall Effect and "Parity Anomaly"

    CERN Document Server

    Yonaga, Kouki; Shibata, Naokazu

    2016-01-01

    We present a relativistic formulation of the quantum Hall effect on a Riemann sphere. An explicit form of the pseudopotential is derived for the relativistic quantum Hall effect with/without mass term.We clarify particular features of the relativistic quantum Hall states with use of the exact diagonalization study of the pseudopotential Hamiltonian. Physical effects of the mass term to relativistic quantum Hall states are investigated in detail.The mass term acts as an interporating parameter between the relativistic and non-relativistic quantum Hall effects. It is pointed out that the mass term inequivalently affects to many-body physics of the positive and negative Landau levels and brings instability of the Laughlin state of the positive first relativistic Landau level as a consequence of the "parity anomaly".

  20. Geometric Photonic Spin Hall Effect with Metapolarization

    CERN Document Server

    Ling, Xiaohui; Yi, Xunong; Luo, Hailu; Wen, Shuangchun

    2014-01-01

    We develop a geometric photonic spin Hall effect (PSHE) which manifests as spin-dependent shift in momentum space. It originates from an effective space-variant Pancharatnam-Berry (PB) phase created by artificially engineering the polarization distribution of the incident light. Unlikely the previously reported PSHE involving the light-matter interaction, the resulting spin-dependent splitting in the geometric PSHE is purely geometrically depend upon the polarization distribution of light which can be tailored by assembling its circular polarization basis with suitably magnitude and phase. This metapolarization idea enables us to manipulate the geometric PSHE by suitably tailoring the polarization geometry of light. Our scheme provides great flexibility in the design of various polarization geometry and polarization-dependent application, and can be extrapolated to other physical system, such as electron beam or atom beam, with the similar spin-orbit coupling underlying.

  1. Photonic analogue of quantum spin Hall effect

    CERN Document Server

    He, Cheng; Liu, Xiao-ping; Lu, Ming-Hui; Chen, Yulin; Feng, Liang; Chen, Yan-Feng

    2014-01-01

    Symmetry-protected photonic topological insulator exhibiting robust pseudo-spin-dependent transportation, analogous to quantum spin Hall (QSH) phases and topological insulators, are of great importance in fundamental physics. Such transportation robustness is protected by time-reversal symmetry. Since electrons (fermion) and photons (boson) obey different statistics rules and associate with different time-reversal operators (i.e., Tf and Tb, respectively), whether photonic counterpart of Kramers degeneracy is topologically protected by bosonic Tb remains unidentified. Here, we construct the degenerate gapless edge states of two photonic pseudo-spins (left/right circular polarizations) in the band gap of a two-dimensional photonic crystal with strong magneto-electric coupling. We further demonstrated that the topological edge states are in fact protected by Tf rather than commonly believed Tb and their pseudo-spin dependent transportation is robust against Tf invariant impurities, discovering for the first tim...

  2. Gauge Physics of Spin Hall Effect

    Science.gov (United States)

    Tan, Seng Ghee; Jalil, Mansoor B. A.; Ho, Cong Son; Siu, Zhuobin; Murakami, Shuichi

    2015-12-01

    Spin Hall effect (SHE) has been discussed in the context of Kubo formulation, geometric physics, spin orbit force, and numerous semi-classical treatments. It can be confusing if the different pictures have partial or overlapping claims of contribution to the SHE. In this article, we present a gauge-theoretic, time-momentum elucidation, which provides a general SHE equation of motion, that unifies under one theoretical framework, all contributions of SHE conductivity due to the kinetic, the spin orbit force (Yang-Mills), and the geometric (Murakami-Fujita) effects. Our work puts right an ambiguity surrounding previously partial treatments involving the Kubo, semiclassical, Berry curvatures, or the spin orbit force. Our full treatment shows the Rashba 2DEG SHE conductivity to be instead of -, and Rashba heavy hole instead of -. This renewed treatment suggests a need to re-derive and re-calculate previously studied SHE conductivity.

  3. On-Chip Microwave Quantum Hall Circulator

    Science.gov (United States)

    Mahoney, A. C.; Colless, J. I.; Pauka, S. J.; Hornibrook, J. M.; Watson, J. D.; Gardner, G. C.; Manfra, M. J.; Doherty, A. C.; Reilly, D. J.

    2017-01-01

    Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1 /1000 th the wavelength by exploiting the chiral, "slow-light" response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330 μ m diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  4. Photonic spin Hall effect in topological insulators

    CERN Document Server

    Zhou, Xinxing; Ling, Xiaohui; Chen, Shizhen; Luo, Hailu; Wen, Shuangchun

    2013-01-01

    In this paper we theoretically investigate the photonic spin Hall effect (SHE) of a Gaussian beam reflected from the interface between air and topological insulators (TIs). The photonic SHE is attributed to spin-orbit coupling and manifests itself as in-plane and transverse spin-dependent splitting. We reveal that the spin-orbit coupling effect in TIs can be routed by adjusting the axion angle variations. Unlike the transverse spin-dependent splitting, we find that the in-plane one is sensitive to the axion angle. It is shown that the polarization structure in magneto-optical Kerr effect is significantly altered due to the spin-dependent splitting in photonic SHE. We theoretically propose a weak measurement method to determine the strength of axion coupling by probing the in-plane splitting of photonic SHE.

  5. Hydrodynamic Electron Flow and Hall Viscosity

    Science.gov (United States)

    Scaffidi, Thomas; Nandi, Nabhanila; Schmidt, Burkhard; Mackenzie, Andrew P.; Moore, Joel E.

    2017-06-01

    In metallic samples of small enough size and sufficiently strong momentum-conserving scattering, the viscosity of the electron gas can become the dominant process governing transport. In this regime, momentum is a long-lived quantity whose evolution is described by an emergent hydrodynamical theory. Furthermore, breaking time-reversal symmetry leads to the appearance of an odd component to the viscosity called the Hall viscosity, which has attracted considerable attention recently due to its quantized nature in gapped systems but still eludes experimental confirmation. Based on microscopic calculations, we discuss how to measure the effects of both the even and odd components of the viscosity using hydrodynamic electronic transport in mesoscopic samples under applied magnetic fields.

  6. Geometric Defects in Quantum Hall States

    CERN Document Server

    Gromov, Andrey

    2016-01-01

    We describe a geometric (or gravitational) analogue of the Laughlin quasiholes in the fractional quantum Hall states. Analogously to the quasiholes these defects can be constructed by an insertion of an appropriate vertex operator into the conformal block representation of a trial wavefunction, however, unlike the quasiholes these defects are extrinsic and do not correspond to true excitations of the quantum fluid. We construct a wavefunction in the presence of such defects and explain how to assign an electric charge and a spin to each defect, and calculate the adiabatic, non-abelian statistics of the defects. The defects turn out to be equivalent to the genons in that their adiabatic exchange statistics can be described in terms of representations of the mapping class group of an appropriate higher genus Riemann surface. We present a general construction that, in principle, allows to calculate the statistics of $\\mathbb Z_n$ genons for any "parent" topological phase. We illustrate the construction on the ex...

  7. Concept of Operating Indoor Skiing Halls with

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....

  8. Magnetic circuit for hall effect plasma accelerator

    Science.gov (United States)

    Manzella, David H. (Inventor); Jacobson, David T. (Inventor); Jankovsky, Robert S. (Inventor); Hofer, Richard (Inventor); Peterson, Peter (Inventor)

    2009-01-01

    A Hall effect plasma accelerator includes inner and outer electromagnets, circumferentially surrounding the inner electromagnet along a thruster centerline axis and separated therefrom, inner and outer magnetic conductors, in physical connection with their respective inner and outer electromagnets, with the inner magnetic conductor having a mostly circular shape and the outer magnetic conductor having a mostly annular shape, a discharge chamber, located between the inner and outer magnetic conductors, a magnetically conducting back plate, in magnetic contact with the inner and outer magnetic conductors, and a combined anode electrode/gaseous propellant distributor, located at a bottom portion of the discharge chamber. The inner and outer electromagnets, the inner and outer magnetic conductors and the magnetically conducting back plate form a magnetic circuit that produces a magnetic field that is largely axial and radially symmetric with respect to the thruster centerline.

  9. Hall MHD Equilibrium of Accelerated Compact Toroids

    Science.gov (United States)

    Howard, S. J.; Hwang, D. Q.; Horton, R. D.; Evans, R. W.; Brockington, S. J.

    2007-11-01

    We examine the structure and dynamics of the compact toroid's magnetic field. The compact toroid is dramatically accelerated by a large rail-gun Lorentz force density equal to j xB. We use magnetic data from the Compact Toroid Injection Experiment to answer the question of exactly where in the system j xB has nonzero values, and to what extent we can apply the standard model of force-free equilibrium. In particular we present a method of analysis of the magnetic field probe signals that allows direct comparison to the predictions of the Woltjer-Taylor force-free model and Turner's generalization of magnetic relaxation in the presence of a non-zero Hall term and fluid vorticity.

  10. Mesoscopic spin Hall effect in semiconductor nanostructures

    Science.gov (United States)

    Zarbo, Liviu

    The spin Hall effect (SHE) is a name given to a collection of diverse phenomena which share two principal features: (i) longitudinal electric current flowing through a paramagnetic semiconductor or metallic sample leads to transverse spin current and spin accumulation of opposite sign at opposing lateral edges; (ii) SHE does not require externally applied magnetic field or magnetic ordering in the equilibrium state of the sample, instead it relies on the presence of spin-orbit (SO) couplings within the sample. This thesis elaborates on a new type of phenomenon within the SHE family, predicted in our recent studies [Phys. Rev. B 72, 075361 (2005); Phys. Rev. Lett. 95, 046601 (2005); Phys. Rev. B 72, 075335 (2005); Phys. Rev. B 73 , 075303 (2006); and Europhys. Lett. 77, 47004 (2007)], where pure spin current flows through the transverse electrodes attached to a clean finitesize two-dimensional electron gas (2DEG) due to unpolarized charge current injected through its longitudinal leads. If transverse leads are removed, the effect manifests as nonequilibrium spin Hall accumulation at the lateral edges of 2DEG wires. The SO coupling driving this SHE effect is of the Rashba type, which arises due to structural inversion asymmetry of semiconductor heterostructure hosting the 2DEG. We term the effect "mesoscopic" because the spin Hall currents and accumulations reach optimal value in samples of the size of the spin precession length---the distance over which the spin of an electron precesses by an angle pi. In strongly SO-coupled structures this scale is of the order of ˜100 nm, and, therefore, mesoscopic in the sense of being much larger than the characteristic microscopic scales (such as the Fermi wavelength, screening length, or the mean free path in disordered systems), but still much smaller than the macroscopic ones. Although the first theoretical proposal for SHE, driven by asymmetry in SO-dependent scattering of spin-up and spin-down electrons off impurities

  11. Concept of Operating Indoor Skiing Halls with

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....

  12. The quantum Hall effect and its contexts

    OpenAIRE

    Rodríguez,Víctor

    2017-01-01

    En este artículo, se atienden ciertas facetas conceptuales y experimentales del efecto Hall cuántico. Se argumenta que el mismo ofrece variados matices para la reflexión filosófica, desde la generación de entidades teóricas hasta la epistemología de la experimentación. La exposición pretende mantener cierta sensibilidad por la dinámica histórica en torno del tema, como así también por las implicaciones metrológicas de ámbitos cuánticos específicos. Dada la enorme producción científica sobre e...

  13. Stacking order dependence of inverse spin Hall effect and anomalous Hall effect in spin pumping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young, E-mail: parksy@kbsi.re.kr [Division of Materials Science, Korea Basic Science Institute, Daejeon 305-806 (Korea, Republic of); Kim, Dong-Jun; Park, Byong-Guk [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-07

    The dependence of the measured DC voltage on the non-magnetic material (NM) in NM/CoFeB and CoFeB/NM bilayers is studied under ferromagnetic resonance conditions in a TE{sub 011} resonant cavity. The directional change of the inverse spin Hall effect (ISHE) voltage V{sub ISHE} for the stacking order of the bilayer can separate the pure V{sub ISHE} and the anomalous Hall effect (AHE) voltage V{sub AHE} utilizing the method of addition and subtraction. The Ta and Ti NMs show a broad deviation of the spin Hall angle θ{sub ISH}, which originates from the AHE in accordance with the high resistivity of NMs. However, the Pt and Pd NMs show that the kinds of NMs with low resistivity are consistent with the previously reported θ{sub ISH} values. Therefore, the characteristics that NM should simultaneously satisfy to obtain a reasonable V{sub ISHE} value in bilayer systems are large θ{sub ISH} and low resistivity.

  14. Learning Cities as Healthy Green Cities: Building Sustainable Opportunity Cities

    Science.gov (United States)

    Kearns, Peter

    2012-01-01

    This paper discusses a new generation of learning cities we have called EcCoWell cities (Economy, Community, Well-being). The paper was prepared for the PASCAL International Exchanges (PIE) and is based on international experiences with PIE and developments in some cities. The paper argues for more holistic and integrated development so that…

  15. Residencia hall del Obispado, en Gescher, Alemania

    Directory of Open Access Journals (Sweden)

    Deilmann, Harald

    1969-02-01

    Full Text Available This Hall has four lecture rooms, each with a capacity for twenty students. They all face north, have lateral and cenithal illumination and cross ventilation. The workshop training halls face south, and there is a gymnasium. Each classroom is also connected with a protected open air space, so that in suitable weather, teaching can be practised out of doors. As the school is devoted to mentally retarded boys and youths, over 2 m2 of floor area has been allowed for each student in the classrooms, since it was estimated that many students would be of the nervous type and would need more room to work freely. Most of the construction is made with unfaced brick and concrete, which are long lasting materials, requiring little maintenance.Comprende cuatro clases propiamente dichas, con una capacidad total de 80 alumnos, a razón de 20 por cada clase, y orientadas al norte, con iluminación cenital y lateral y ventilación cruzada. Los locales donde se imparten las enseñanzas de taller tienen orientación sur. Se ha previsto, además, un gimnasio. Cada clase dispone de un recinto protegido para que, cuando las condiciones atmosféricas lo permitan, se pueda desarrollar en él la enseñanza al aire libre. Como la escuela está destinada a niños y adolescentes retrasados mentales, se partió de un espacio superior a los 2 m2 por alumno, pensando en que parte de ellos iban a ser niños nerviosos y, como consecuencia, la necesidad que tendrían de amplitud suficiente para desenvolverse adecuadamente. La construcción se ha desarrollado, en general, a base de fábrica de ladrillo a cara vista y hormigón visto, materiales de gran duración y prácticamente exentos de entretenimiento.

  16. Branding Cities, Changing Societies

    DEFF Research Database (Denmark)

    Ooi, Can-Seng

    Societal changes are seldom discussed in the literature on city branding. The time element is important because it highlights the fluctuating reality of society. The city brand message freezes the place but in fact, the city branding exercise is a continuous process. Society emerges too. City...... brands are supposed to accentuate the uniqueness of the city, be built from the bottom-up and reflect the city's identity. This paper highlights three paradoxes, pointing out that city branding processes can also make cities more alike, bring about societal changes and forge new city identities. A city...... branding campaign does not just present the city, it may change the city. The relationships between the branding exercise and the city are intertwined in the evolution of the place....

  17. Hall transport of divalent metal ion modified DNA lattices

    Energy Technology Data Exchange (ETDEWEB)

    Dugasani, Sreekantha Reddy; Lee, Keun Woo; Yoo, Sanghyun; Gnapareddy, Bramaramba; Bashar, Saima; Park, Sung Ha, E-mail: sunghapark@skku.edu [Department of Physics and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Si Joon; Jung, Joohye; Jung, Tae Soo; Kim, Hyun Jae, E-mail: hjk3@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2015-06-29

    We investigate the Hall transport characteristics of double-crossover divalent metal ion (Cu{sup 2+}, Ni{sup 2+}, Zn{sup 2+}, and Co{sup 2+})-modified DNA (M-DNA) lattices grown on silica via substrate-assisted growth. The electronic characteristics of the M-DNA lattices are investigated by varying the concentration of the metal ions and then conducting Hall measurements, including resistivity, Hall mobility, carrier concentration, and magneto resistance. The tendency of the resistivity and Hall mobility was to initially decrease as the ion concentration increased, until reaching the saturation concentration (C{sub s}) of each metal ion, and then to increase as the ion concentration increased further. On the other hand, the carrier concentration revealed the opposite tendency as the resistivity and Hall mobility. The specific binding (≤C{sub s}) and the nonspecific aggregates (>C{sub s}) of the ions into the DNA lattices were significantly affected by the Hall characteristics. The numerical ranges of the Hall parameters revealed that the M-DNA lattices with metal ions had semiconductor-like characteristics. Consequently, the distinct characteristics of the electrical transport through M-DNA lattices will provide useful information on the practical use of such structures in physical devices and chemical sensors.

  18. Effective Field Theory of Fractional Quantized Hall Nematics

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Michael; /MIT, LNS; Nayak, Chetan; /Station Q, UCSB; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

    2012-06-06

    We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.

  19. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Marie, Pierre; Jeong, Cheol-Ho; Brunskog, Jonas

    2012-01-01

    Noise generated by the audience during musical performances is audible and sometimes disturbing. In this study, an attempt to estimate such audience noise was carried out. From the recordings of performances in five performance spaces (four concert halls and one opera house), probability density...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended....

  20. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Marie, Pierre; Brunskog, Jonas

    2012-01-01

    Noise generated by the audience during musical performances is audible and sometimes disturbing. In this study, an attempt to estimate such audience noise was carried out. From the recordings of performances in five performance spaces (four concert halls and one opera house), probability density...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended...

  1. Anomalous Hall effect in Fe/Gd bilayers

    KAUST Repository

    Xu, W. J.

    2010-04-01

    Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

  2. Modelling of micro-Hall sensors for magnetization imaging

    Science.gov (United States)

    Manzin, A.; Nabaei, V.

    2014-05-01

    This paper presents a numerical model for the study of micro-Hall magnetometry applications, aiming at evaluating the sensitivity of semiconductor miniaturized devices to the stray field of permalloy nanostructures with ring and disk geometry. The procedure couples a micromagnetic code, for the calculation of the stray field generated by the nanomagnet, to a 2D classical transport model for the determination of the electric potential distribution inside the Hall plate. The model is applied to study the sensitivity of a micro-Hall device in the detection of magnetization switching processes characterized by vortex state, focusing on the influence of magnetic nanostructure position.

  3. TCC2, the target hall of the SPS North Area

    CERN Multimedia

    1978-01-01

    In the foreground can be seen the three proton beam branches leading to the targets enclosed in an assembly of iron blocks with the positioning mechanism on top. In the background, the six secondary beams lead off towards the experimental areas, H2/P2, H4/E4/P4 (from T2 via TT81) and H6, H8 (from T4 via TT82) towards the hall EHN1, M2 from T6 via TT83 towards the hall EHN2. The development proton beam line P0 leads off from T4 via TT83 towards TCC8 and hall ECN3 (NAHIF).

  4. Composed planar Hall effect sensors with dual-mode operation

    OpenAIRE

    Vladislav Mor; Debangsu Roy; Moty Schultz; Lior Klein

    2016-01-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make ...

  5. Hall conductance and topological invariant for open systems.

    Science.gov (United States)

    Shen, H Z; Wang, W; Yi, X X

    2014-09-24

    The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.

  6. Hall effect in CNT doped YBCO high temperature superconductor

    Directory of Open Access Journals (Sweden)

    S Dadras

    2010-09-01

    Full Text Available In order to study Hall effect in pure and CNT doped YBCO polycrystalline samples, we have measured longitudinal and transverse voltages at the different magnetic field (0-9T in the vortex state. We found a sign reversal for pure sample near 3T and double sign reversal of the Hall coefficient for CNT doped sample near 3 and 5T. It can be deduced that CNT doping caused strong flux pinning and Hall double sign reversal in this compound.

  7. Quantized Anomalous Hall Effect in Magnetic Topological Insulators

    Institute of Scientific and Technical Information of China (English)

    YU Rui

    2011-01-01

    The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are thndamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively. The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.

  8. Kelvin-Helmholtz versus Hall magnetoshear instability in astrophysical flows.

    Science.gov (United States)

    Gómez, Daniel O; Bejarano, Cecilia; Mininni, Pablo D

    2014-05-01

    We study the stability of shear flows in a fully ionized plasma. Kelvin-Helmholtz is a well-known macroscopic and ideal shear-driven instability. In sufficiently low-density plasmas, also the microscopic Hall magnetoshear instability can take place. We performed three-dimensional simulations of the Hall-magnetohydrodynamic equations where these two instabilities are present, and carried out a comparative study. We find that when the shear flow is so intense that its vorticity surpasses the ion-cyclotron frequency of the plasma, the Hall magnetoshear instability is not only non-negligible, but it actually displays growth rates larger than those of the Kelvin-Helmholtz instability.

  9. Expats rank Chinese cities

    Institute of Scientific and Technical Information of China (English)

    By Lv Dong

    2012-01-01

    Beijing, April The results of the "2011 Amazing China- The Most Attractive Chinese Cities for Foreigners" election are released. Expats choose Beijing, Shanghai, Tianjin and other cities as Chinas 10 most attractive cities for foreigners.

  10. Pittsburgh City Facilities

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Pittsburgh City FacilitiesIncludes: City Administrative Buildings, Police Stations, Fire Stations, EMS Stations, DPW Sites, Senior Centers, Recreation Centers, Pool...

  11. Pittsburgh City Facilities

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Pittsburgh City FacilitiesIncludes: City Administrative Buildings, Police Stations, Fire Stations, EMS Stations, DPW Sites, Senior Centers, Recreation Centers,...

  12. Cities, Towns and Villages - City Limit (polygon)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Data available online through GeoStor at http://www.geostor.arkansas.gov. Arkansas Cities: This data set contains all of the city limit boundaries within the state...

  13. From University Heights to Cooperstown: Halls of Fame and American Memory

    Science.gov (United States)

    Friss, Evan J.

    2005-01-01

    This article examines the development and function of American halls of fame as cultural memory institutions. By comparing the Hall of Fame for Great Americans with the National Baseball Hall of Fame, the author posits that halls of fame illuminate the ways in which cultural memory institutions can, through an archival process, preserve, instill,…

  14. Energy Efficiency Improvements to Wundar Hall, a Historic Building on the Concordia Campus, Milwaukee, Wisconsin

    Energy Technology Data Exchange (ETDEWEB)

    Karman, Nathan

    2012-11-29

    The Forest County Potawatomi Community (FCPC or Community) implemented energy efficiency improvements to revitalize Wundar Hall, a 34,000 square foot (SF) building that was formerly used as a dormitory and is listed on the National Registry of Historic Places, into an office building. Wundar Hall is the first of many architecturally and historically significant buildings that the Community hopes to renovate at the former Concordia College campus, property on the near west side of Milwaukee that was taken into trust for the Community by the United States on July 10, 1990 (collectively, the Concordia Trust Property). As part of this project, which was conducted with assistance from the Department of Energy's Tribal Energy Program (TEP), the Community updated and/or replaced the building envelope, mechanical systems, the plumbing system, the electrical infrastructure, and building control systems. The project is expected to reduce the building's natural gas consumption by 58% and the electricity consumption by 55%. In addition, the project was designed to act as a catalyst to further renovation of the Concordia Trust Property and the neighborhood. The City of Milwaukee has identified redevelopment of the Concordia Trust Property as a Catalytic Project for revitalizing the near west side. The Tribe envisions a revitalized, mixed-use campus of community services, education, and economic developmen-providing services to the Indian community and jobs to the neighborhood.

  15. City positioning theories and city core competencies

    Institute of Scientific and Technical Information of China (English)

    Xinquan; Zhu

    2007-01-01

    Gity positioning The Chinese city in a decision develops the topic of the destiny. Since the 90's of 20 centuries, the economic integral and globalization developed rapidly. The development make national boundary become not so important, the function of the city is increasingly outstanding. In other words, national competition ability is morally now on the city competition ability. At the same time, this development result that the industry is divided internationally and is divided in cities. Therefore, under the condition of globalization, if the city wants the superior development, it must take advantages and avoid shortage, to position the city accurately, establish the competition and development the strategy. The city positioning is clearly defined the city competition ability, more important it indicated the direction of the city development. Trough the analysis of the resource and environment of the city, decide an accurate position of the best function of the city, well configure the inner and outside resource, catch the opportunities,face the challenges, maximized the market share in order to maximized the wealth and city competition ability.

  16. Summer residence hall renovations focus on student comfort, environmental sustainability

    OpenAIRE

    DeLauder, Rachel

    2009-01-01

    With the majority of students home for the summer, Virginia Tech Housing Services has undertaken a variety of improvements and renovations in its residence halls aimed at increasing comfort and safety for students, while decreasing overall environmental impact.

  17. Segal-Bargmann-Hall Transform and Geometric Quantization

    Institute of Scientific and Technical Information of China (English)

    刘卫平; 王正栋; 胡大鹏

    2003-01-01

    @@ Using geometric methods, Hall has proved that the Segal-Bargmann transform for a con-nected Lie group K of compact type is an isometric isomorphism [H1] and is unique when Kis simply connected [H7].

  18. A High Performance Cathode Heater for Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High current hollow cathodes are the baseline electron source for next generation high power Hall thrusters. Currently for electron sources providing current levels...

  19. Wellness: A Developmental Programming Model for Residence Halls.

    Science.gov (United States)

    Warner, Mark J.

    1985-01-01

    Demonstrates how a Wellness model can be an effective vehicle for promoting developmental programs in residence halls. The Wellness model is examined in terms of marketing, student development theory, and balanced programming. (BL)

  20. High Throughput Hall Thruster for Small Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Co. Inc. proposes to develop a high throughput, nominal 100 W Hall Effect Thruster (HET). This HET will be sized for small spacecraft (< 180 kg), including...

  1. Magnesium Hall Thruster for Solar System Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation being developed in this program is a Mg Hall Effect Thruster system that would open the door for In-Situ Resource Utilization based solar system...

  2. High Input Voltage Hall Thruster Discharge Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall scope of this Phase I/II effort is the development of a high efficiency 15kW (nominal) Hall thruster discharge converter. In Phase I, Busek Co. Inc. will...

  3. High Throughput Hall Thruster for Small Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek is developing a high throughput nominal 100-W Hall Effect Thruster. This device is well sized for spacecraft ranging in size from several tens of kilograms to...

  4. The Dream Comes True in the Golden Hall

    Institute of Scientific and Technical Information of China (English)

    JianZhong; ChenJianguo

    2004-01-01

    Nanjing Traditional Music Ensemble has long dreamed of performing in Vienna's Golden Hall.Now the dream has come true.the whole troupe felt so exciting that they did not even sleep well during the flight.

  5. Mini array of quantum Hall devices based on epitaxial graphene

    Science.gov (United States)

    Novikov, S.; Lebedeva, N.; Hämäläinen, J.; Iisakka, I.; Immonen, P.; Manninen, A. J.; Satrapinski, A.

    2016-05-01

    Series connection of four quantum Hall effect (QHE) devices based on epitaxial graphene films was studied for realization of a quantum resistance standard with an up-scaled value. The tested devices showed quantum Hall plateaux RH,2 at a filling factor v = 2 starting from a relatively low magnetic field (between 4 T and 5 T) when the temperature was 1.5 K. The precision measurements of quantized Hall resistance of four QHE devices connected by triple series connections and external bonding wires were done at B = 7 T and T = 1.5 K using a commercial precision resistance bridge with 50 μA current through the QHE device. The results showed that the deviation of the quantized Hall resistance of the series connection of four graphene-based QHE devices from the expected value of 4×RH,2 = 2 h/e2 was smaller than the relative standard uncertainty of the measurement (resistance bridge.

  6. Magnesium Hall Thruster for Solar System Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to prove the feasibility of a Mg Hall effect thruster system that would open the door for In-Situ Resource Utilization (ISRU) based solar system...

  7. Pragmatic data fusion uncertainty concerns: Tribute to Dave L. Hall

    CSIR Research Space (South Africa)

    Blasch, E

    2016-07-01

    Full Text Available to knowledge acquisition and delivery. A summary of the uncertainty issues from Dave Hall, originating with the Joint Directors of the Laboratories (JDL) model, include these attributes across the JDL Levels which are: data (variance), object assessment...

  8. Hall Determination of Atomic Radii of Alkali Metals

    Science.gov (United States)

    Houari, Ahmed

    2008-01-01

    I will propose here an alternative method for determining atomic radii of alkali metals based on the Hall measurements of their free electron densities and the knowledge of their crystal structure. (Contains 2 figures.)

  9. Valleytronics. The valley Hall effect in MoS₂ transistors.

    Science.gov (United States)

    Mak, K F; McGill, K L; Park, J; McEuen, P L

    2014-06-27

    Electrons in two-dimensional crystals with a honeycomb lattice structure possess a valley degree of freedom (DOF) in addition to charge and spin. These systems are predicted to exhibit an anomalous Hall effect whose sign depends on the valley index. Here, we report the observation of this so-called valley Hall effect (VHE). Monolayer MoS2 transistors are illuminated with circularly polarized light, which preferentially excites electrons into a specific valley, causing a finite anomalous Hall voltage whose sign is controlled by the helicity of the light. No anomalous Hall effect is observed in bilayer devices, which have crystal inversion symmetry. Our observation of the VHE opens up new possibilities for using the valley DOF as an information carrier in next-generation electronics and optoelectronics.

  10. Fractional quantum Hall effect in the absence of Landau levels.

    Science.gov (United States)

    Sheng, D N; Gu, Zheng-Cheng; Sun, Kai; Sheng, L

    2011-07-12

    It is well known that the topological phenomena with fractional excitations, the fractional quantum Hall effect, will emerge when electrons move in Landau levels. Here we show the theoretical discovery of the fractional quantum Hall effect in the absence of Landau levels in an interacting fermion model. The non-interacting part of our Hamiltonian is the recently proposed topologically non-trivial flat-band model on a checkerboard lattice. In the presence of nearest-neighbouring repulsion, we find that at 1/3 filling, the Fermi-liquid state is unstable towards the fractional quantum Hall effect. At 1/5 filling, however, a next-nearest-neighbouring repulsion is needed for the occurrence of the 1/5 fractional quantum Hall effect when nearest-neighbouring repulsion is not too strong. We demonstrate the characteristic features of these novel states and determine the corresponding phase diagram.

  11. Hall Viscosity I: Linear Response Theory for Viscosity

    Science.gov (United States)

    Bradlyn, Barry; Goldstein, Moshe; Read, Nicholas

    2012-02-01

    In two dimensional systems with broken time-reversal symmetry, there can exist a non-dissipative viscosity coefficient [1,2,3]. This Hall viscosity is similar in nature to the non-dissipative Hall conductivity. In order to investigate this phenomenon further, we develop a linear response formalism for viscosity. We derive a Kubo formula for the frequency dependent viscosity tensor in the long wavelength limit. We compute the viscosity tensor for the free electron gas, integer quantum Hall systems, and two-dimensional paired superfluids. In the zero frequency limit, we show how the known results [3,4] for the Hall viscosity are recovered.[4pt] [1] J. Avron, R. Seiler, and P. Zograf, Phys. Rev. Lett. 75, 697 (1995).[0pt] [2] P. Levay, J. Math. Phys. 36, 2792 (1995).[0pt] [3] N. Read, Phys. Rev. B 79, 045308 (2009).[0pt] [4] N. Read and E. Rezayi, Phys. Rev. B 84, 085316 (2011).

  12. Global regularity for generalized Hall magneto-hydrodynamics systems

    Directory of Open Access Journals (Sweden)

    Renhui Wan

    2015-06-01

    Full Text Available In this article, we consider the tridimensional generalized Hall magneto-hydrodynamics (Hall-MHD system, with $(-\\Delta^\\alpha u$ and $(-\\Delta^\\beta b$. For $\\alpha\\ge 5/4$, $\\beta\\ge 7/4$, we obtain the global regularity of classical solutions. For $0<\\alpha<5/4$ and $1/2<\\beta<7/4$, with small data, the system also possesses global classical solutions. In addition, for the standard Hall-MHD system, $\\alpha=\\beta=1$, by adding a suitable condition, we give a positive answer to the open question in [3]. At last, we study the regularity criterions of generalized Hall-MHD system. In particular, we prove the regularity criterion in terms of horizontal gradient $\

  13. Sports hall: a technical challenge; Gym artistique en Suisse romande. Salle de sport: defit technique

    Energy Technology Data Exchange (ETDEWEB)

    Scaramiglia, V.

    2004-07-01

    Not far away from the airport at Vernier, the city of Geneva has built a novel gym hall, 'la Salle de l'Ecu'. It's an oblong building of 39 x 54 meters ground surface covered by a curved roof reaching a height of 8 meters at the center and 4 meters at the sides. The building shape allows to minimize the facade area resulting in low costs for heating and maintenance. The main building materials are wood, glass and metal. The facades consist of two thermovarnished metal sheets perforated on the inner side and embracing the thermal/acoustical insulation. The area of openings and insulating windows is minimized for energetic reasons and a number of photovoltaic arrays has been mounted on the roof for energetic and ecological reasons.

  14. Phonon Hall Effect in Four-Terminal Junctions

    OpenAIRE

    Zhang, Lifa; Wang, Jian-Sheng; Li, Baowen

    2009-01-01

    Using an exact nonequilibrium Green's function formulism, the phonon Hall effect for paramagnetic dielectrics is studied in a four-terminal device setting. The temperature difference in the transverse direction of the heat current is calculated for two-dimensional models with the magnetic field perpendicular to the plane. We find a surprising result that the square lattice does not have the phonon Hall effect while a honeycomb lattice has. This can be explained by symmetry. The temperature di...

  15. Chern-Simons Dynamics and the Quantum Hall Effect

    CERN Document Server

    Balachandran, A P

    1991-01-01

    Theoretical developments during the past several years have shown that large scale properties of the Quantum Hall system can be successfully described by effective field theories which use the Chern-Simons interaction. In this article, we first recall certain salient features of the Quantum Hall Effect and their microscopic explanation. We then review one particular approach to their description based on the Chern-Simons Lagrangian and its variants.

  16. Spin and Isospin: Exotic Order in Quantum Hall Ferromagnets

    Science.gov (United States)

    Girvin, Steven M.

    Quantum mechanics is a strange business, and the quantum physics of strongly correlated many-electron systems can be stranger still. Good examples are the various quantum Hall effects. They are among the most remarkable many-body quantum phenomena discovered in the second half of the 20th century, comparable in intellectual import to superconductivity and superfluidity. The quantum Hall effects are an extremely rich set of phenomena with deep and truly fundamental theoretical implications...

  17. Hall viscosity and electromagnetic response of electrons in graphene

    Science.gov (United States)

    Sherafati, Mohammad; Principi, Alessandro; Vignale, Giovanni

    2016-09-01

    We derive an analytic expression for the geometric Hall viscosity of noninteracting electrons in a single graphene layer in the presence of a perpendicular magnetic field. We show that a recently derived formula in C. Hoyos and D. T. Son [Phys. Rev. Lett. 108, 066805 (2012), 10.1103/PhysRevLett.108.066805], which connects the coefficient of q2 in the wave-vector expansion of the Hall conductivity σx y(q ) of the two-dimensional electron gas (2DEG) to the Hall viscosity and the orbital diamagnetic susceptibility of that system, continues to hold for graphene, in spite of the lack of Galilean invariance, with a suitable definition of the effective mass. We also show that, for a sufficiently large number of occupied Landau levels in the positive-energy sector, the Hall conductivity of electrons in graphene reduces to that of a Galilean-invariant 2DEG with an effective mass given by ℏ kF/vF (cyclotron mass). Even in the most demanding case, i.e., when the chemical potential falls between the zeroth and the first Landau levels, the cyclotron mass formula gives results accurate to better than 1%. The connection between the Hall conductivity and the viscosity provides a possible avenue to measure the Hall viscosity in graphene.

  18. Tunnelling anomalous and planar Hall effects (Conference Presentation)

    Science.gov (United States)

    Matos-Abiague, Alex; Scharf, Benedikt; Han, Jong E.; Hankiewicz, Ewelina M.; Zutic, Igor

    2016-10-01

    We theoretically show how the interplay between spin-orbit coupling (SOC) and magnetism can result in a finite tunneling Hall conductance, transverse to the applied bias. For two-dimensional tunnel junctions with a ferromagnetic lead and magnetization perpendicular to the current flow, the detected anomalous Hall voltage can be used to extract information not only about the spin polarization but also about the strength of the interfacial SOC. In contrast, a tunneling current across a ferromagnetic barrier on the surface of a three-dimensional topological insulator (TI) can induce a planar Hall response even when the magnetization is oriented along the current flow[1]. The tunneling nature of the states contributing to the planar Hall conductance can be switched from the ordinary to the Klein regimes by the electrostatic control of the barrier strength. This allows for an enhancement of the transverse response and a giant Hall angle, with the tunneling planar Hall conductance exceeding the longitudinal component. Despite the simplicity of a single ferromagnetic region, the TI/ferromagnet system exhibits a variety of functionalities. In addition to a spin-valve operation for magnetic sensing and storing information, positive, negative, and negative differential conductances can be tuned by properly adjusting the barrier potential and/or varying the magnetization direction. Such different resistive behaviors in the same system are attractive for potential applications in reconfigurable spintronic devices. [1] B. Scharf, A. Matos-Abiague, J. E. Han, E. M. Hankiewicz, and I. Zutic, arXiv:1601.01009 (2016).

  19. The quantum Hall's effect:A quantum electrodynamic phenomenon

    Institute of Scientific and Technical Information of China (English)

    A.I. Arbab

    2012-01-01

    We have applied Maxwell's equations to study the physics of quantum Hall's effect.The electromagnetic properties of this system are obtained.The Hall's voltage,VH =2πh2ns/e rn,where ns is the electron number density,for a 2-dimensional system,and h =2πh is the Planck's constant,is found to coincide with the voltage drop across the quantum capacitor.Consideration of the cyclotronic motion of electrons is found to give rise to Hall's resistance.Ohmic resistances in the horizontal and vertical directions have been found to exist before equilibrium state is reached.At a fundamental level,the Hall's effect is found to be equivalent to a resonant LCR circuit with LH =2π m/e2ns and CH =me2/2πh2ns satisfying the resonance condition with resonant frequency equal to the inverse of the scattering (relaxation) time,Ts.The Hall's resistance is found to be RH =√LH/CH.The Hall's resistance may be connected with the impedance that the electron wave experiences when it propagates in the 2-dimeasional gas.

  20. Magnetometry of micro-magnets with electrostatically defined Hall bars

    Energy Technology Data Exchange (ETDEWEB)

    Lachance-Quirion, Dany; Camirand Lemyre, Julien; Bergeron, Laurent; Sarra-Bournet, Christian [Département de Physique, Université de Sherbrooke, J1K 2R1 Sherbrooke, Québec (Canada); Pioro-Ladrière, Michel, E-mail: michel.pioro-ladriere@usherbrooke.ca [Département de Physique, Université de Sherbrooke, J1K 2R1 Sherbrooke, Québec (Canada); CIFAR Program in Quantum Information Science, Canadian Institute for Advanced Research (CIFAR), M5G 1Z8 Toronto, Ontario (Canada)

    2015-11-30

    Micro-magnets are key components for quantum information processing with individual spins, enabling arbitrary rotations and addressability. In this work, characterization of sub-micrometer sized CoFe ferromagnets is performed with Hall bars electrostatically defined in a two-dimensional electron gas. Due to the ballistic nature of electron transport in the cross junction of the Hall bar, anomalies such as the quenched Hall effect appear near zero external magnetic field, thus hindering the sensitivity of the magnetometer to small magnetic fields. However, it is shown that the sensitivity of the diffusive limit can be almost completely restored at low temperatures using a large current density in the Hall bar of about 10 A/m. Overcoming the size limitation of conventional etched Hall bars with electrostatic gating enables the measurement of magnetization curves of 440 nm wide micro-magnets with a signal-to-noise ratio above 10{sup 3}. Furthermore, the inhomogeneity of the stray magnetic field created by the micro-magnets is directly measured using the gate-voltage-dependent width of the sensitive area of the Hall bar.

  1. Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials.

    Science.gov (United States)

    Song, Justin C W; Kats, Mikhail A

    2016-12-14

    Carrier dynamics acquire a new character in the presence of Bloch-band Berry curvature, which naturally arises in gapped Dirac materials (GDMs). Here, we argue that photoresponse in GDMs with small band gaps is dramatically enhanced by Berry curvature. This manifests in a giant and saturable Hall photoconductivity when illuminated by circularly polarized light. Unlike Hall motion arising from a Lorentz force in a magnetic field, which impedes longitudinal carrier motion, Hall photoconductivity arising from Berry curvature can boost longitudinal carrier transport. In GDMs, this results in a helicity-dependent photoresponse in the Hall regime, where photoconductivity is dominated by its Hall component. We find that the induced Hall conductivity per incident irradiance is enhanced by up to 6 orders of magnitude when moving from the visible regime (with corresponding band gaps) to the far infrared. These results suggest that narrow-gap GDMs are an ideal test-bed for the unique physics that arise in the presence of Berry curvature and open a new avenue for infrared and terahertz optoelectronics.

  2. The spin Hall effect in a quantum gas.

    Science.gov (United States)

    Beeler, M C; Williams, R A; Jiménez-García, K; LeBlanc, L J; Perry, A R; Spielman, I B

    2013-06-13

    Electronic properties such as current flow are generally independent of the electron's spin angular momentum, an internal degree of freedom possessed by quantum particles. The spin Hall effect, first proposed 40 years ago, is an unusual class of phenomena in which flowing particles experience orthogonally directed, spin-dependent forces--analogous to the conventional Lorentz force that gives the Hall effect, but opposite in sign for two spin states. Spin Hall effects have been observed for electrons flowing in spin-orbit-coupled materials such as GaAs and InGaAs (refs 2, 3) and for laser light traversing dielectric junctions. Here we observe the spin Hall effect in a quantum-degenerate Bose gas, and use the resulting spin-dependent Lorentz forces to realize a cold-atom spin transistor. By engineering a spatially inhomogeneous spin-orbit coupling field for our quantum gas, we explicitly introduce and measure the requisite spin-dependent Lorentz forces, finding them to be in excellent agreement with our calculations. This 'atomtronic' transistor behaves as a type of velocity-insensitive adiabatic spin selector, with potential application in devices such as magnetic or inertial sensors. In addition, such techniques for creating and measuring the spin Hall effect are clear prerequisites for engineering topological insulators and detecting their associated quantized spin Hall effects in quantum gases. As implemented, our system realizes a laser-actuated analogue to the archetypal semiconductor spintronic device, the Datta-Das spin transistor.

  3. Anisotropic intrinsic spin Hall effect in quantum wires.

    Science.gov (United States)

    Cummings, A W; Akis, R; Ferry, D K

    2011-11-23

    We use numerical simulations to investigate the spin Hall effect in quantum wires in the presence of both Rashba and Dresselhaus spin-orbit coupling. We find that the intrinsic spin Hall effect is highly anisotropic with respect to the orientation of the wire, and that the nature of this anisotropy depends strongly on the electron density and the relative strengths of the Rashba and Dresselhaus spin-orbit couplings. In particular, at low densities, when only one subband of the quantum wire is occupied, the spin Hall effect is strongest for electron momentum along the [N110] axis, which is the opposite of what is expected for the purely 2D case. In addition, when more than one subband is occupied, the strength and anisotropy of the spin Hall effect can vary greatly over relatively small changes in electron density, which makes it difficult to predict which wire orientation will maximize the strength of the spin Hall effect. These results help to illuminate the role of quantum confinement in spin-orbit-coupled systems, and can serve as a guide for future experimental work on the use of quantum wires for spin-Hall-based spintronic applications.

  4. Planar Hall magnetoresistive aptasensor for thrombin detection.

    Science.gov (United States)

    Sinha, B; Ramulu, T S; Kim, K W; Venu, R; Lee, J J; Kim, C G

    2014-09-15

    The use of aptamer-based assays is an emerging and attractive approach in disease research and clinical diagnostics. A sensitive aptamer-based sandwich-type sensor is presented to detect human thrombin using a planar Hall magnetoresistive (PHR) sensor in cooperation with superparamagnetic labels. A PHR sensor has the great advantages of a high signal-to-noise ratio, a small offset voltage and linear response in the low-field region, allowing it to act as a high-resolution biosensor. In the system presented here, the sensor has an active area of 50 µm × 50 µm with a 10-nm gold layer deposited onto the sensor surface prior to the binding of thiolated DNA primary aptamer. A polydimethylsiloxane well of 600-µm radius and 1-mm height was prepared around the sensor surface to maintain the same specific area and volume for each sensor. The sensor response was traced in real time upon the addition of streptavidin-functionalized magnetic labels on the sensor. A linear response to the thrombin concentration in the range of 86 pM-8.6 µM and a lower detection limit down to 86 pM was achieved by the proposed present method with a sample volume consumption of 2 µl. The proposed aptasensor has a strong potential for application in clinical diagnosis.

  5. Acoustics in Halls for Speech and Music

    Science.gov (United States)

    Gade, Anders C.

    This chapter deals specifically with concepts, tools, and architectural variables of importance when designing auditoria for speech and music. The focus will be on cultivating the useful components of the sound in the room rather than on avoiding noise from outside or from installations, which is dealt with in Chap. 11. The chapter starts by presenting the subjective aspects of the room acoustic experience according to consensus at the time of writing. Then follows a description of their objective counterparts, the objective room acoustic parameters, among which the classical reverberation time measure is only one of many, but still of fundamental value. After explanations on how these parameters can be measured and predicted during the design phase, the remainder of the chapter deals with how the acoustic properties can be controlled by the architectural design of auditoria. This is done by presenting the influence of individual design elements as well as brief descriptions of halls designed for specific purposes, such as drama, opera, and symphonic concerts. Finally, some important aspects of loudspeaker installations in auditoria are briefly touched upon.

  6. Brand new hall in the main building

    CERN Multimedia

    Corinne Pralavorio

    2014-01-01

    The renovation of the UNIQA and post office premises is getting under way, with their reopening scheduled for the spring.   The renovation of the large hall in the main building (Building 500) has finally reached the home straight. As of this week, building contractors will get to work on the last part – the offices of UNIQA and La Poste. In the last week of November, the two concessions moved their offices across Route Scherrer to the same part of Building 510 where UBS was temporarily housed during the bank’s refurbishment. Their services were therefore unavailable for one day. The renovation work will last until the spring, with the new offices expected to open in May 2015. Between now and then, the windows and insulation will be completely refitted, with a view to reducing heat loss considerably, and, above all, the premises will be modernised to improve customer reception and service. For example, UNIQA’s new premises will feature a confidential area, guarantee...

  7. The integer quantum hall effect revisited

    Energy Technology Data Exchange (ETDEWEB)

    Michalakis, Spyridon [Los Alamos National Laboratory; Hastings, Matthew [Q STATION, CALIFORNIA

    2009-01-01

    For T - L x L a finite subset of Z{sup 2}, let H{sub o} denote a Hamiltonian on T with periodic boundary conditions and finite range, finite strength intetactions and a unique ground state with a nonvanishing spectral gap. For S {element_of} T, let q{sub s} denote the charge at site s and assume that the total charge Q = {Sigma}{sub s {element_of} T} q{sub s} is conserved. Using the local charge operators q{sub s}, we introduce a boundary magnetic flux in the horizontal and vertical direction and allow the ground state to evolve quasiadiabatically around a square of size one magnetic flux, in flux space. At the end of the evolution we obtain a trivial Berry phase, which we compare, via a method reminiscent of Stokes Theorem. to the Berry phase obtained from an evolution around an exponentially small loop near the origin. As a result, we show, without any averaging assumption, that the Hall conductance is quantized in integer multiples of e{sup 2}/h up to exponentially small corrections of order e{sup -L/{zeta}}, where {zeta}, is a correlation length that depends only on the gap and the range and strength of the interactions.

  8. Magnetized Epsilon-Near-Zero (ENZ) Structures: Hall Opacity, Hall Transparency, and One-Way Photonic Surface States

    CERN Document Server

    Davoyan, Arthur

    2013-01-01

    We study propagation of transverse-magnetic (TM) electromagnetic waves in the bulk and at the surface of magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge: we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one-way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to a possibility for backscattering immune wave propagation and isolation.

  9. Numerical analysis of Hall effect on the performance of magnetohydrodynamic heat shield system based on nonequilibrium Hall parameter model

    Science.gov (United States)

    Li, Kai; Liu, Jun; Liu, Weiqiang

    2017-01-01

    Magnetohydrodynamic (MHD) heat shield system, a novel thermal protection technique in the hypersonic field, has been paid much attention in recent years. In the real flight condition, not only the Lorentz force but also the Hall electric field is induced by the interaction between ionized air post shock and magnetic field. In order to analyze the action mechanisms of the Hall effect, numerical methods of coupling thermochemical nonequilibrium flow field with externally applied magnetic field as well as the induced electric field are constructed and validated. Based on the nonequilibrium model of Hall parameter, numerical simulations of the MHD heat shield system is conducted under two different magnetic induction strengths (B0=0.2 T, 0.5 T) on a reentry capsule forebody. Results show that, the Hall effect is the same under the two magnetic induction strengths when the wall is assumed to be conductive. For this case, with the Hall effect taken into account, the Lorentz force counter stream diminishes a lot and the circumferential component dominates, resulting that the heat flux and shock-off distance approach the case without MHD control. However, for the insulating wall, the Hall effect acts in different ways under these two magnetic induction strengths. For this case, with the Hall effect taken into account, the performance of MHD heat shield system approaches the case neglecting the Hall effect when B0 equals 0.2 T. Such performance becomes worse when B0 equals 0.5 T and the aerothermal environment on the capsule shoulder is even worse than the case without MHD control.

  10. Water changed the cities

    DEFF Research Database (Denmark)

    Elle, Morten; Jensen, Marina Bergen

    An improvement in water infrastructure and cleaning up the waters changed many harbour cities in Denmark at the beginning of the 90s. The harbour cities changed from drity, run-down industrial harbours to clean and attractive harbour dwelling creating new city centres and vital city areas...

  11. Water changed the cities

    DEFF Research Database (Denmark)

    Elle, Morten; Jensen, Marina Bergen

    An improvement in water infrastructure and cleaning up the waters changed many harbour cities in Denmark at the beginning of the 90s. The harbour cities changed from drity, run-down industrial harbours to clean and attractive harbour dwelling creating new city centres and vital city areas...

  12. Observational evidence for Hall drift and Hall waves in the crusts of isolated young neutron stars

    CERN Document Server

    Xie, Yi

    2013-01-01

    The observed long-term spin-down evolution of isolated radio pulsars cannot be explained by the standard magnetic dipole radiation with a constant braking torque. However how and why the torque varies still remains controversial, which is an outstanding problem in our understanding of neutron stars. Many pulsars have been observed with significant long-term changes of their spin-down rates modulated by quasi-periodic oscillations. Applying the phenomenological model of pulsar timing noise we developed recently to the observed precise pulsar timing data, here we show that, the Hall drift and Hall waves in their crusts are responsible for the observed long-term evolution of the spin-down rates and their quasi-periodic modulations, respectively. Consequently the majority of dipolar magnetic field lines are restricted to their outer crusts, rather than penetrating the cores of the neutron stars. Understanding of the nature of pulsar timing noise not only reveals the interior physics of neutron stars, but also all...

  13. The Impacts of Heatwaves on Mortality Differ with Different Study Periods: A Multi-City Time Series Investigation.

    Science.gov (United States)

    Wang, Xiao Yu; Guo, Yuming; FitzGerald, Gerry; Aitken, Peter; Tippett, Vivienne; Chen, Dong; Wang, Xiaoming; Tong, Shilu

    2015-01-01

    Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney). Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality. Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data. The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.

  14. The Impacts of Heatwaves on Mortality Differ with Different Study Periods: A Multi-City Time Series Investigation.

    Directory of Open Access Journals (Sweden)

    Xiao Yu Wang

    Full Text Available Different locations and study periods were used in the assessment of the relationships between heatwaves and mortality. However, little is known about the comparability and consistency of the previous effect estimates in the literature. This study assessed the heatwave-mortality relationship using different study periods in the three largest Australian cities (Brisbane, Melbourne and Sydney.Daily data on climatic variables and mortality for the three cities were obtained from relevant government agencies between 1988 and 2011. A consistent definition of heatwaves was used for these cities. Poisson generalised additive model was fitted to assess the impact of heatwaves on mortality.Non-accidental and circulatory mortality significantly increased during heatwaves across the three cities even with different heatwave definitions and study periods. Using the summer data resulted in the largest increase in effect estimates compared to those using the warm season or the whole year data.The findings may have implications for developing standard approaches to evaluating the heatwave-mortality relationship and advancing heat health warning systems. It also provides an impetus to methodological advance for assessing climate change-related health consequences.

  15. Eigenanalysis of Ideal Hall MHD Turbulence

    Science.gov (United States)

    Fu, T.; Shebalin, J. V.

    2011-12-01

    Ideal, incompressible, homogeneous, Hall magnetohydrodynamic (HMHD) turbulence may be investigated through a Fourier spectral method. In three-dimensional periodic geometry, the independent Fourier coefficients represent a canonical ensemble described by a Gaussian probability density. The canonical ensemble is based on the conservation of three invariants: total energy, generalized helicity, and magnetic helicity. Generalized helicity in HMHD takes the place of cross helicity in MHD. The invariants determine the modal probability density giving the spectral structure and equilibrium statistics of ideal HMHD, which are compared to known MHD results. New results in absolute equilibrium ensemble theory are derived using a novel approach that involves finding the eigenvalues of a Hermitian covariance matrix for each modal probability density. The associated eigenvectors transform the original phase space variables into eigenvariables through a special unitary transformation. These are the normal modes which facilitate the analysis of ideal HMHD non-linear dynamics. The eigenanalysis predicts that the low wavenumber modes with very small eigenvalues may have mean values that are large compared to their standard deviations, contrary to the ideal ensemble prediction of zero mean values. (Expectation values may also be relatively large at the highest wave numbers, but the addition of even small levels of dissipation removes any relevance this may have for real-world turbulence.) This behavior is non-ergodic over very long times for a numerical simulation and is termed 'broken ergodicity'. For fixed values of the ideal invariants, the effect is seen to be enhanced with increased numerical grid size. Broken ergodicity at low wave number modes gives rise to large-scale, quasi-stationary, coherent structure. Physically, this corresponds to plasma relaxation to force-free states. For real HMHD turbulence with dissipation, broken ergodicity and coherent structure are still

  16. Azimuthal Spoke Propagation in Hall Effect Thrusters

    Science.gov (United States)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Spokes are azimuthally propagating perturbations in the plasma discharge of Hall Effect Thrusters (HETs) that travel in the E x B direction and have been observed in many different systems. The propagation of azimuthal spokes are investigated in a 6 kW HET known as the H6 using ultra-fast imaging and azimuthally spaced probes. A spoke surface is a 2-D plot of azimuthal light intensity evolution over time calculated from 87,500 frames/s videos. The spoke velocity has been determined using three methods with similar results: manual fitting of diagonal lines on the spoke surface, linear cross-correlation between azimuthal locations and an approximated dispersion relation. The spoke velocity for three discharge voltages (300, 400 and 450 V) and three anode mass flow rates (14.7, 19.5 and 25.2 mg/s) yielded spoke velocities between 1500 and 2200 m/s across a range of normalized magnetic field settings. The spoke velocity was inversely dependent on magnetic field strength for low B-field settings and asymptoted at B-field higher values. The velocities and frequencies are compared to standard drifts and plasma waves such as E x B drift, electrostatic ion cyclotron, magnetosonic and various drift waves. The empirically approximated dispersion relation yielded a characteristic velocity that matched the ion acoustic speed for 5 eV electrons that exist in the near-anode and near-field plume regions of the discharge channel based on internal measurements. Thruster performance has been linked to operating mode where thrust-to-power is maximized when azimuthal spokes are present so investigating the underlying mechanism of spokes will benefit thruster operation.

  17. Mode Transitions in Hall Effect Thrusters

    Science.gov (United States)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Mode transitions have been commonly observed in Hall Effect Thruster (HET) operation where a small change in a thruster operating parameter such as discharge voltage, magnetic field or mass flow rate causes the thruster discharge current mean value and oscillation amplitude to increase significantly. Mode transitions in a 6-kW-class HET called the H6 are induced by varying the magnetic field intensity while holding all other operating parameters constant and measurements are acquired with ion saturation probes and ultra-fast imaging. Global and local oscillation modes are identified. In the global mode, the entire discharge channel oscillates in unison and azimuthal perturbations (spokes) are either absent or negligible. Downstream azimuthally spaced probes show no signal delay between each other and are very well correlated to the discharge current signal. In the local mode, signals from the azimuthally spaced probes exhibit a clear delay indicating the passage of "spokes" and are not well correlated to the discharge current. These spokes are localized oscillations propagating in the ExB direction that are typically 10-20% of the mean value. In contrast, the oscillations in the global mode can be 100% of the mean value. The transition between global and local modes occurs at higher relative magnetic field strengths for higher mass flow rates or higher discharge voltages. The thrust is constant through mode transition but the thrust-to-power decreased by 25% due to increasing discharge current. The plume shows significant differences between modes with the global mode significantly brighter in the channel and the near-field plasma plume as well as exhibiting a luminous spike on thruster centerline. Mode transitions provide valuable insight to thruster operation and suggest improved methods for thruster performance characterization.

  18. Dos escudos de madera policromada del Ayuntamiento de Toledo = Two Wooden Polychromated Coat of Arms from the Town Hall of Toledo

    Directory of Open Access Journals (Sweden)

    Antonio Perla de las Parras

    2016-05-01

    Full Text Available El presente estudio trata de aportar información de carácter histórico sobre dos escudos de madera policromada que se encontraban descontextualizados en las Casas Consistoriales de Toledo y que muy probablemente pertenecieron a la desaparecida armadura del Salón de Capítulos del piso alto. Tras las reformas llevadas a cabo en los últimos años, aparecieron en alguna de las dependencias municipales, siendo recogidos en el Archivo Municipal de Toledo, organismo que se hizo cargo de su restauración. Una vez concluida ésta, han vuelto a ser colgados en el Ayuntamiento, en un nuevo emplazamiento.The current research tries to render information regarding the historical characteristics about two coat of arms made of polychromated wood, which were found out of his original location in the Town Hall of Toledo. It is probable that they belonged to the lost framework of the Assembly Hall in the high floor, although it is not an affirmation which pretends to be conclusive nor it is the main purpose of this article. After the repairings made during the past years, these coat of arms were found in the Town Hall premises, and were then stored by the Archivo Municipal de Toledo, organisation that has been in charge of its restoration. Once the restoration was completed, they were hanged again at the City Hall in a new emplacement. 

  19. City health development planning.

    Science.gov (United States)

    Green, Geoff; Acres, John; Price, Charles; Tsouros, Agis

    2009-11-01

    The objective of this evaluation was to review the evolution and process of city health development planning (CHDP) in municipalities participating in the Healthy Cities Network organized by the European Region of the World Health Organization. The concept of CHDP combines elements from three theoretical domains: (a) health development, (b) city governance and (c) urban planning. The setting was the 56 cities which participated in Phase III (1998-2002) of the Network. Evidence was gathered from documents either held in WHO archives or made available from Network cities and from interviews with city representatives. CHDPs were the centrepiece of Phase III, evolving from city health plans developed in Phase II. They are strategic documents giving direction to municipalities and partner agencies. Analysis revealed three types of CHDP, reflecting the realpolitik of each city. For many cities, the process of CHDP was as important as the plan itself.

  20. High temperature Hall measurement setup for thin film characterization

    Science.gov (United States)

    Adnane, L.; Gokirmak, A.; Silva, H.

    2016-07-01

    Hall measurement using the van der Pauw technique is a common characterization approach that does not require patterning of contacts. Measurements of the Hall voltage and electrical resistivity lead to the product of carrier mobility and carrier concentration (Hall coefficient) which can be decoupled through transport models. Based on the van der Paw method, we have developed an automated setup for Hall measurements from room temperature to ˜500 °C of semiconducting thin films of a wide resistivity range. The resistivity of the film and Hall coefficient is obtained from multiple current-voltage (I-V) measurements performed using a semiconductor parameter analyzer under applied constant "up," zero, and "down" magnetic field generated with two neodymium permanent magnets. The use of slopes obtained from multiple I-Vs for the three magnetic field conditions offer improved accuracy. Samples are preferred in square shape geometry and can range from 2 mm to 25 mm side length. Example measurements of single-crystal silicon with known doping concentration show the accuracy and reliability of the measurement.

  1. Stability of Hall equilibria in neutron star crusts

    CERN Document Server

    Marchant, Pablo; Valdivia, Juan Alejandro; Hoyos, Jaime H

    2014-01-01

    In the solid crusts of neutron stars, the advection of the magnetic field by the current-carrying electrons, an effect known as Hall drift, should play a very important role as the ions remain essentially fixed (as long as the solid does not break). Although Hall drift preserves the magnetic field energy, it has been argued that it may drive a turbulent cascade to scales at which Ohmic dissipation becomes effective, allowing a much faster decay in objects with very strong fields. On the other hand, it has been found that there are "Hall equilibria", i.e., field configurations that are unaffected by Hall drift. Here, we address the crucial question of the stability of these equilibria through axially symmetric (2D) numerical simulations of Hall drift and Ohmic diffusion, with the simplifying assumption of uniform electron density and conductivity. We demonstrate the 2D-stability of a purely poloidal equilibrium, for which Ohmic dissipation makes the field evolve towards an attractor state through adjacent stab...

  2. Suitable reverberation times for halls for rock and pop music.

    Science.gov (United States)

    Adelman-Larsen, Niels Werner; Thompson, Eric R; Gade, Anders C

    2010-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers as expert listeners. Correlations between the measurements show that clarity, including bass frequencies down to 63 Hz, is important for the general impression of the acoustics of the hall. The best-rated halls in the study have reverberation times that are approximately frequency independent from 0.6 to 1.2 s for hall volumes from 1000 to 6000 m(3). The worst rated halls in the study had significantly higher reverberation times in the 63 and 125 Hz bands. Since most audiences at rock concerts are standing, absorption coefficients were measured with a standing audience from 63 Hz to 4 kHz. These measurements showed that a standing audience absorbs about five times as much energy in mid-/high-frequency bands as in low-frequency bands.

  3. Reconnection dynamics with secondary tearing instability in compressible Hall plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Z. W., E-mail: zwma@zju.edu.cn; Wang, L. C.; Li, L. J. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

    2015-06-15

    The dynamics of a secondary tearing instability is systematically investigated based on compressible Hall magnetohydrodynamic. It is found that in the early nonlinear phase of magnetic reconnection before onset of the secondary tearing instability, the geometry of the magnetic field in the reconnection region tends to form a Y-type structure in a weak Hall regime, instead of an X-type structure in a strong Hall regime. A new scaling law is found that the maximum reconnection rate in the early nonlinear stage is proportional to the square of the ion inertial length (γ∝d{sub i}{sup 2}) in the weak Hall regime. In the late nonlinear phase, the thin elongated current sheet associated with the Y-type geometry of the magnetic field breaks up to form a magnetic island due to a secondary tearing instability. After the onset of the secondary tearing mode, the reconnection rate is substantially boosted by the formation of the X-type geometries of magnetic field in the reconnection regions. With a strong Hall effect, the maximum reconnection rate linearly increases with the increase of the ion inertial length (γ∝d{sub i})

  4. The local nature of incompressibility of quantum Hall effect

    Science.gov (United States)

    Kendirlik, E. M.; Sirt, S.; Kalkan, S. B.; Ofek, N.; Umansky, V.; Siddiki, A.

    2017-01-01

    Since the experimental realization of the integer quantum Hall effect in a two-dimensional electron system, the interrelation between the conductance quantization and the topological properties of the system has been investigated. Assuming that the two-dimensional electron system is described by a Bloch Hamiltonian, system is insulating in the bulk of sample throughout the quantum Hall plateau due to a magnetic field induced energy gap. Meanwhile, the system is conducting at the edges resembling a 2+1 dimensional topological insulator without time-reversal symmetry. Here, by our magneto-transport measurements performed on GaAs/AlGaAs high purity Hall bars with two inner contacts we show that incompressible strips formed at the edges result in Hall quantization, even if the bulk is compressible. Consequently, the relationship between the quantum Hall effect and topological bulk insulator breaks for specific field intervals within the plateaus. The measurement of conducting bulk, strongly challenges all existing single-particle theories. PMID:28071652

  5. Higher (odd dimensional quantum Hall effect and extended dimensional hierarchy

    Directory of Open Access Journals (Sweden)

    Kazuki Hasebe

    2017-07-01

    Full Text Available We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S2k−1 in the SO(2k−1 monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S2k−1 to the one-dimension higher SO(2k gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah–Patodi–Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.

  6. Higher (odd) dimensional quantum Hall effect and extended dimensional hierarchy

    Science.gov (United States)

    Hasebe, Kazuki

    2017-07-01

    We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S 2 k - 1 in the SO (2 k - 1) monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S 2 k - 1 to the one-dimension higher SO (2 k) gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah-Patodi-Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.

  7. Spin Hall effects in mesoscopic Pt films with high resistivity

    Science.gov (United States)

    Qin, Chuan; Luo, Yongming; Zhou, Chao; Cai, Yunjiao; Jia, Mengwen; Chen, Shuhan; Wu, Yizheng; Ji, Yi

    2016-10-01

    The energy efficiency of the spin Hall effects (SHE) can be enhanced if the electrical conductivity is decreased without sacrificing the spin Hall conductivity. The resistivity of Pt films can be increased to 150-300 µΩ · cm by mesoscopic lateral confinement, thereby decreasing the conductivity. The SHE and inverse spin Hall effects (ISHE) in these mesoscopic Pt films are explored at 10 K by using the nonlocal spin injection/detection method. All relevant physical quantities are determined in situ on the same substrate, and a quantitative approach is developed to characterize all processes effectively. Extensive measurements with various Pt thickness values reveal an upper limit for the Pt spin diffusion length: {λ\\text{pt}}   ⩽  0.8 nm. The average product of {λ\\text{pt}} and the Pt spin Hall angle {α\\text{H}} is substantial: {α\\text{H}}{λ\\text{pt}}   =  (0.142  ±  0.040) nm for 4 nm thick Pt, though a gradual decrease is observed at larger Pt thickness. The results suggest enhanced spin Hall effects in resistive mesoscopic Pt films.

  8. Concert halls with strong lateral reflections enhance musical dynamics.

    Science.gov (United States)

    Pätynen, Jukka; Tervo, Sakari; Robinson, Philip W; Lokki, Tapio

    2014-03-25

    One of the most thrilling cultural experiences is to hear live symphony-orchestra music build up from a whispering passage to a monumental fortissimo. The impact of such a crescendo has been thought to depend only on the musicians' skill, but here we show that interactions between the concert-hall acoustics and listeners' hearing also play a major role in musical dynamics. These interactions contribute to the shoebox-type concert hall's established success, but little prior research has been devoted to dynamic expression in this three-part transmission chain as a complete system. More forceful orchestral playing disproportionately excites high frequency harmonics more than those near the note's fundamental. This effect results in not only more sound energy, but also a different tone color. The concert hall transmits this sound, and the room geometry defines from which directions acoustic reflections arrive at the listener. Binaural directional hearing emphasizes high frequencies more when sound arrives from the sides of the head rather than from the median plane. Simultaneously, these same frequencies are emphasized by higher orchestral-playing dynamics. When the room geometry provides reflections from these directions, the perceived dynamic range is enhanced. Current room-acoustic evaluation methods assume linear behavior and thus neglect this effect. The hypothesis presented here is that the auditory excitation by reflections is emphasized with an orchestra forte most in concert halls with strong lateral reflections. The enhanced dynamic range provides an explanation for the success of rectangularly shaped concert-hall geometry.

  9. NASA HERMeS Hall Thruster Electrical Configuration Characterization

    Science.gov (United States)

    Peterson, Peter Y.; Kamhawi, Hani; Huang, Wensheng; Yim, John; Herman, Daniel; Williams, George; Gilland, James; Hofer, Richard

    2015-01-01

    The NASA Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) Hall thruster has been the subject of extensive technology maturation in preparation for development into a flight ready propulsion system. Part of the technology maturation was to test the TDU-1 thruster in several ground based electrical configurations to assess the thruster robustness and suitability to successful in-space operation. The ground based electrical configuration testing has recently been demonstrated as an important step in understanding and assessing how a Hall thruster may operate differently in-space compared to ground based testing, and to determine the best configuration to conduct development and qualification testing. This paper describes the electrical configuration testing of the HERMeS TDU-1 Hall thruster in NASA Glenn Research Center's Vacuum Facility 5. The three electrical configurations examined were 1) thruster body tied to facility ground, 2) thruster floating, and 3) thruster body electrically tied to cathode common. The HERMeS TDU-1 Hall thruster was also configured with two different exit plane boundary conditions, dielectric and conducting, to examine the influence on the electrical configuration characterization.

  10. The local nature of incompressibility of quantum Hall effect

    Science.gov (United States)

    Kendirlik, E. M.; Sirt, S.; Kalkan, S. B.; Ofek, N.; Umansky, V.; Siddiki, A.

    2017-01-01

    Since the experimental realization of the integer quantum Hall effect in a two-dimensional electron system, the interrelation between the conductance quantization and the topological properties of the system has been investigated. Assuming that the two-dimensional electron system is described by a Bloch Hamiltonian, system is insulating in the bulk of sample throughout the quantum Hall plateau due to a magnetic field induced energy gap. Meanwhile, the system is conducting at the edges resembling a 2+1 dimensional topological insulator without time-reversal symmetry. Here, by our magneto-transport measurements performed on GaAs/AlGaAs high purity Hall bars with two inner contacts we show that incompressible strips formed at the edges result in Hall quantization, even if the bulk is compressible. Consequently, the relationship between the quantum Hall effect and topological bulk insulator breaks for specific field intervals within the plateaus. The measurement of conducting bulk, strongly challenges all existing single-particle theories.

  11. Nonlinear Quantum Hall effects in Rarita-Schwinger gas

    CERN Document Server

    Luo, Xi; Wan, Xiangang; Yu, Yue

    2016-01-01

    Emergence of higher spin relativistic fermionic materials becomes a new favorite in the study of condensed matter physics. Massive Rarita-Schwinger 3/2-spinor was known owning very exotic properties, such as the superluminal fermionic modes and even being unstable in an external magnetic field. Due to the superluminal modes and the non-trivial constraints on the Rarita-Schwinger gas, we exposit anomalous properties of the Hall effects in (2+1)-dimensions which subvert the well-known quantum Hall paradigms. First, the Hall conductance of a pure Rarita-Schwinger gas is step-like but not plateau-quantized, instead of the linear dependence on the filling factor for a pure spin-1/2 Dirac gas. In reality, the Hall conductance of the Dirac gas is of quantized integer plateaus with the unit $\\frac{e^2}h$ due to the localization away from the Landau level centers. If the general localization rule is applicable to the disordered Rarita-Schwinger gas, the Hall plateaus are also expected to appear but they are nonlinearl...

  12. Spin Hall torques generated by rare-earth thin films

    Science.gov (United States)

    Reynolds, Neal; Jadaun, Priyamvada; Heron, John T.; Jermain, Colin L.; Gibbons, Jonathan; Collette, Robyn; Buhrman, R. A.; Schlom, D. G.; Ralph, D. C.

    2017-02-01

    We report an initial experimental survey of spin Hall torques generated by the rare-earth metals Gd, Dy, Ho, and Lu, along with comparisons to first-principles calculations of their spin Hall conductivities. Using spin torque ferromagnetic resonance (ST-FMR) measurements and dc-biased ST-FMR, we estimate lower bounds for the spin Hall torque ratio, ξSH, of ≈0.04 for Gd, ≈0.05 for Dy, ≈0.14 for Ho, and ≈0.014 for Lu. The variations among these elements are qualitatively consistent with results from first principles [density-functional theory (DFT) in the local density approximation with a Hubbard-U correction]. The DFT calculations indicate that the spin Hall conductivity is enhanced by the presence of the partially filled f orbitals in Dy and Ho, which suggests a strategy to further strengthen the contribution of the f orbitals to the spin Hall effect by shifting the electron chemical potential.

  13. SHORT ANALYSIS OF THE BUDGETARY REVENUE OF BAIA MARE CITY HALL

    Directory of Open Access Journals (Sweden)

    Vasile Berlingher

    2013-09-01

    Full Text Available The understanding of theoretical approaches associated with public organization and its management elements which are different from a financial point of view can be achieved only if it provides a clarification of the concepts that are related to public concept. Demarcations are necessary to create a discussion basis with management and economic identity. Thus, there is a distinction to public management, which is a different concept, but similar in popularity among study subjects. Economic and managerial perspective forces to the selection of a number of concepts that are associated with the public concept adapted to the organization (public good, public company, public sector, public management. Each of these should be explained briefly, even if the basic concept of “public” may be subject of interpretation and dispute. It is natural that the definition of other concepts can generate a variety of interpretations, it is preferred succinct definition, although thus eliminates certain details which, from another perspective, would seem important.

  14. Gender Representation in an Electronic City Hall: Female Adoption of Santa Monica's PEN System.

    Science.gov (United States)

    Collins-Jarvis, Lori A.

    1993-01-01

    Discussion of the use of electronic networking systems by women focuses on a study of their use of the Public Electronic Network (PEN) in Santa Monica (California). Characteristics of PEN that contributed to female adoption are described; gender, political participation, and motivation are examined; and future research is suggested. (46…

  15. Micro-four-point Probe Hall effect Measurement method

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong

    2008-01-01

    barriers and with a magnetic field applied normal to the plane of the sheet. Based on this potential, analytical expressions for the measured four-point resistance in presence of a magnetic field are derived for several simple sample geometries. We show how the sheet resistance and Hall effect......We report a new microscale Hall effect measurement method for characterization of semiconductor thin films without need for conventional Hall effect geometries and metal contact pads. We derive the electrostatic potential resulting from current flow in a conductive filamentary sheet with insulating...... contributions may be separated using dual configuration measurements. The method differs from conventional van der Pauw measurements since the probe pins are placed in the interior of the sample region, not just on the perimeter. We experimentally verify the method by micro-four-point probe measurements...

  16. Axisymmetric nonlinear waves and structures in Hall plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Tanim [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, California 94551-0808 (United States)

    2012-06-15

    In this paper, a general equation for the evolution of an axisymmetric magnetic field in a Hall plasma is derived, with an integral similar to the Grad-Shafranov equation. Special solutions arising from curvature-whistler drift modes that propagate along the electron drift as a Burger's shock and nonlinear periodic and soliton-like solutions to the generalized Grad-Shafranov integral-are analyzed. We derive analytical and numerical solutions in a classical electron-ion Hall plasma, in which electrons and ions are the only species in the plasmas. Results may then be applied to the following low-ionized astrophysical plasmas: in protostellar disks, in which the ions may be coupled to the motion of gases; and in molecular clouds and protostellar jets, in which the much heavier charged dust in a dusty Hall plasma may be collisionally coupled to the gas.

  17. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    the number of participants 7.5 persons higher pr. activity compared to club activities. This implies that clubs during peak hours could include more participants. Another possibility to increase utilization is if the management of sport facilities forced sport clubs and other organisers to adapt......BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...... be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...

  18. Precise quantization of anomalous Hall effect near zero magnetic field

    Science.gov (United States)

    Bestwick, Andrew; Fox, Eli; Kou, Xufeng; Pan, Lei; Wang, Kang; Goldhaber-Gordon, David

    2015-03-01

    The quantum anomalous Hall effect (QAHE) has recently been of great interest due to its recent experimental realization in thin films of Cr-doped (Bi, Sb)2Te3, a ferromagnetic 3D topological insulator. The presence of ferromagnetic exchange breaks time-reversal symmetry, opening a gap in the surface states, but gives rise to dissipationless chiral conduction at the edge of a magnetized film. Ideally, this leads to vanishing longitudinal resistance and Hall resistance quantized to h /e2 , where h is Planck's constant and e is the electron charge, but perfect quantization has so far proved elusive. Here, we study the QAHE in the limit of zero applied magnetic field, and measure Hall resistance quantized to within one part per 10,000. Deviation from quantization is due primarily to thermally activated carriers, which can be nearly eliminated through adiabatic demagnetization cooling. This result demonstrates an important step toward dissipationless electron transport in technologically relevant conditions.

  19. Crossover between spin swapping and Hall effect in disordered systems

    KAUST Repository

    Saidaoui, Hamed Ben Mohamed

    2015-07-16

    We theoretically study the crossover between spin Hall effect and spin swapping, a recently predicted phenomenon that consists of the interchange between the current flow and its spin polarization directions [M. B. Lifshits and M. I. Dyakonov, Phys. Rev. Lett. 103, 186601 (2009)]. Using a tight-binding model with spin-orbit coupled disorder, spin Hall effect, spin relaxation, and spin swapping are treated on equal footing. We demonstrate that spin swapping and spin Hall effect present very different dependencies as a function of the spin-orbit coupling and disorder strengths and confirm that the former exceeds the latter in the parameter range considered. Three setups are proposed for the experimental observation of the spin swapping effect.

  20. Quantum Hall fluids in the presence of topological defects

    CERN Document Server

    Iacomino, Patrizia; Naddeo, Adele

    2013-01-01

    We review our recent results on the physics of quantum Hall fluids at Jain and non conventional fillings within a general field theoretic framework. We focus on a peculiar conformal field theory (CFT), the one obtained by means of the m-reduction technique, and stress its power in describing strongly correlated low dimensional condensed matter systems in the presence of localized impurities or topological defects. By exploiting the notion of Morita equivalence for field theories on noncommutative two-tori and choosing rational values of the noncommutativity parameter, we find a general one-to-one correspondence between the m-reduced conformal field theory describing the quantum Hall fluid and an Abelian noncommutative field theory. As an example of application of the formalism, we study a quantum Hall bilayer at nonconventional fillings in the presence of a localized topological defect and briefly recall its boundary state structure corresponding to two different boundary conditions, the periodic as well as t...

  1. Novel Hall sensors developed for magnetic field imaging systems

    Science.gov (United States)

    Cambel, Vladimír; Karapetrov, Goran; Novosad, Valentyn; Bartolomé, Elena; Gregušová, Dagmar; Fedor, Ján; Kúdela, Robert; Šoltýs, Ján

    2007-09-01

    We report here on the fabrication and application of novel planar Hall sensors based on shallow InGaP/AlGaAs/GaAs heterostructure with a two-dimensional electron gas (2DEG) as an active layer. The sensors are developed for two kinds of experiments. In the first one, magnetic samples are placed directly on the Hall sensor. Room temperature experiments of permalloy objects evaporated onto the sensor are presented. In the second experiment, the sensor scans close over a multigranular superconducting sample prepared on a YBCO thin film. Large-area and high-resolution scanning experiments were performed at 4.2 K with the Hall probe scanning system in a liquid helium flow cryostat.

  2. Graphene and the universality of the quantum Hall effect

    DEFF Research Database (Denmark)

    Tzalenchuk, A.; Janssen, T. J.B.M.; Kazakova, O.

    2013-01-01

    The quantum Hall effect allows the standard for resistance to be defined in terms of the elementary charge and Planck's constant alone. The effect comprises the quantization of the Hall resistance in two-dimensional electron systems in rational fractions of RK=h/e2=25812.8074434(84) Ω (Mohr P. J....... et al., Rev. Mod. Phys., 84 (2012) 1527), the resistance quantum. Despite 30 years of research into the quantum Hall effect, the level of precision necessary for metrology, a few parts per billion, has been achieved only in silicon and III-V heterostructure devices. In this lecture we show...... that graphene - a single layer of carbon atoms - beats these well-established semiconductor materials as the system of choice for the realisation of the quantum resistance standard. Here we shall briefly describe graphene technology, discuss the structure and electronic properties of graphene, including...

  3. Collective edge modes in fractional quantum Hall systems

    Science.gov (United States)

    Nguyen, Hoang K.; Joglekar, Yogesh N.; Murthy, Ganpathy

    2004-07-01

    Over the past few years one of us (Murthy) in collaboration with Shankar has developed an extended Hamiltonian formalism capable of describing the ground-state and low-energy excitations in the fractional quantum Hall regime. The Hamiltonian, expressed in terms of composite fermion operators, incorporates all the nonperturbative features of the fractional Hall regime, so that conventional many-body approximations such as Hartree-Fock and time-dependent Hartree-Fock are applicable. We apply this formalism to develop a microscopic theory of the collective edge modes in fractional quantum Hall regime. We present the results for edge mode dispersions at principal filling factors ν=1/3 , 1/5 , and 2/5 for systems with unreconstructed edges. The primary advantage of the method is that one works in the thermodynamic limit right from the beginning, thus avoiding the finite-size effects which ultimately limit exact diagonalization studies.

  4. Metal-to-insulator switching in quantum anomalous Hall states

    Science.gov (United States)

    Pan, Lei; Kou, Xufeng; Wang, Jing; Fan, Yabin; Choi, Eun Sang; Shao, Qiming; Zhang, Shou Cheng; Wang, Kang Lung

    Quantum anomalous Hall effect (QAHE) was recently achieved in magnetic topological insulator films as a form of dissipationless transport without external magnetic field. However, the universal phase diagram of QAHE and its relation with quantum Hall effect (QHE) remain to be investigated. Here, we report the experimental observation of the giant longitudinal resistance peak and zero Hall conductance plateau at the coercive field in the six quintuple-layer (Cr0.12Bi0.26Sb0.62)2 Te3 film, and demonstrate the metal-to-insulator switching between two opposite QAHE plateau states up to 0.3 K. The universal QAHE phase diagram is further confirmed through the angle-dependent measurements. Our results address that the quantum phase transitions in both QAHE and QHE regimes are in the same universality class, yet the microscopic details are different.

  5. Quantitative Analysis of Spin Hall Effect in Nanostructures

    Directory of Open Access Journals (Sweden)

    S. Katiyal

    2012-07-01

    Full Text Available Spin transport in nano structured devices depends on interfaceresistance, electrode resistance, Spin polarization and Spindiffusion length. Spin Hall Effect (SHE, caused by Spin–orbitscattering in nonmagnetic conductors, gives rise to theconversion between Spin and charge currents in a non localdevice. Recently, SHE has been observed using non local Spininjection in metal-based nanostructured devices, which pavesthe way for future Spin electronic applications. In presentwork we have theoretically analyzed the SHE phenomenabased on experimental results obtained till date. We have usedthe Hamiltonian of two dimensional electron systems withRashba Spin-orbit coupling. We undertake the quantitativeanalysis of Spin Hall Effect in low dimensional materialsusing Spin dynamical equations and Spin Hall conductivity.

  6. Thermal Hall Effect of Spin Excitations in a Kagome Magnet.

    Science.gov (United States)

    Hirschberger, Max; Chisnell, Robin; Lee, Young S; Ong, N P

    2015-09-04

    At low temperatures, the thermal conductivity of spin excitations in a magnetic insulator can exceed that of phonons. However, because they are charge neutral, the spin waves are not expected to display a thermal Hall effect. However, in the kagome lattice, theory predicts that the Berry curvature leads to a thermal Hall conductivity κ(xy). Here we report observation of a large κ(xy) in the kagome magnet Cu(1-3, bdc) which orders magnetically at 1.8 K. The observed κ(xy) undergoes a remarkable sign reversal with changes in temperature or magnetic field, associated with sign alternation of the Chern flux between magnon bands. The close correlation between κ(xy) and κ(xx) firmly precludes a phonon origin for the thermal Hall effect.

  7. The onset of MHD nanofluid convection with Hall current effect

    Science.gov (United States)

    Yadav, Dhananjay; Lee, Jinho

    2015-08-01

    In this paper, the combined effects of Hall current and magnetic field on the onset of convection in an electrically conducting nanofluid layer heated from below is investigated. A physically more realistic boundary condition on the nanoparticle volume fraction is taken i.e. the nanoparticle flux is assumed to be zero rather than prescribing a nanoparticle volume fraction on the rigid impermeable boundaries. The employed model incorporates the effects of Brownian motion and thermophoresis. The resulting eigenvalue problem is solved using the Galerkin method. The results obtained during the analysis are presented graphically for an alumina-water nanofluid. It is observed that the effect of smaller values of the Hall current parameter and the nanoparticle parameters accelerate the onset of convection, while larger values of the Hall current parameter (≥ 15) have no effect on the system stabilities.

  8. The complete set of Casimirs in Hall-magnetohydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kawazura, Yohei [Graduate School of Frontier Sciences, University of Tokyo Kashiwa, Chiba 277-8561 (Japan); Hameiri, Eliezer [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

    2012-08-15

    A procedure for determining all the Casimir constants of motion in magnetohydrodynamics (MHD) [E. Hameiri, Phys. Plasmas 11, 3423 (2004)] is extended to Hall-MHD. We obtain and solve differential equations for the variational derivatives of all the Casimirs, which must be satisfied for any dynamically accessible motion in Hall-MHD. In an extension of the more commonly considered Hall-MHD model, we also include the electron fluid entropy. The most interesting case for plasma confinement, which is usually true for axisymmetric configurations but desirable in general, is when both the magnetic field and the ion velocity field form the two separate families of nested toroidal surfaces. The Casimirs are then three functionals for each surface, involving the fluxes of certain vector fields and the number of particles contained in each. We also determine a family of independent Casimirs in a general configuration.

  9. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...... been collected. RESULTS The number of participants per activity is higher during peak hours, which is expected when demand is high. However, the usage of sport floor only differs slightly between peak and low hours. Both during peak and low hours on average 80-100 per cent of floor space is used......BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...

  10. Spontaneous chiral symmetry breaking of Hall magnetohydrodynamic turbulence.

    Science.gov (United States)

    Meyrand, Romain; Galtier, Sébastien

    2012-11-01

    Hall magnetohydrodynamics (MHD) is investigated through three-dimensional direct numerical simulations. We show that the Hall effect induces a spontaneous chiral symmetry breaking of the turbulent dynamics. The normalized magnetic polarization is introduced to separate the right- (R) and left-handed (L) fluctuations. A classical k(-7/3) spectrum is found at small scales for R magnetic fluctuations which corresponds to the electron MHD prediction. A spectrum compatible with k(-11/3) is obtained at large-scales for the L magnetic fluctuations; we call this regime the ion MHD. These results are explained heuristically by rewriting the Hall MHD equations in a succinct vortex dynamical form. Applications to solar wind turbulence are discussed.

  11. D0 Detector Collision Hall Oxygen Deficiancy Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; /Fermilab

    1992-08-06

    EN-258, D0 Platform ODH Analysts. provided the oxygen deficiency hazard analysts for the D0 detector in the Assembly Hall. This note covers the same analysis. but revised for the Collision Hall. Liquid cryogens. released and warming to atmosphere conditions, expand to, on average, seven hundred times their liquid volume, and displace vital atmospheric oxygen. An oxygen deficiency hazard analysis assesses the increased risk to personnel in areas containing cryogenic systems. The D0 detector Collision Hall ODH analysis has been approached five different ways using established methods. If the low beta quad magnets are powered, and the exhaust rate is below 4220 scfm, the area is ODH class 1. In any other case, the analysis shows the area to be ODH class 0 as equipped (with ventilation fans) and requiring no special safety provisions. System designers have provided for a reduced oxygen level detection and warning system as well as emergency procedures to address fault conditions.

  12. The complete set of Casimirs in Hall-magnetohydrodynamics

    Science.gov (United States)

    Kawazura, Yohei; Hameiri, Eliezer

    2012-08-01

    A procedure for determining all the Casimir constants of motion in magnetohydrodynamics (MHD) [E. Hameiri, Phys. Plasmas 11, 3423 (2004)] is extended to Hall-MHD. We obtain and solve differential equations for the variational derivatives of all the Casimirs, which must be satisfied for any dynamically accessible motion in Hall-MHD. In an extension of the more commonly considered Hall-MHD model, we also include the electron fluid entropy. The most interesting case for plasma confinement, which is usually true for axisymmetric configurations but desirable in general, is when both the magnetic field and the ion velocity field form the two separate families of nested toroidal surfaces. The Casimirs are then three functionals for each surface, involving the fluxes of certain vector fields and the number of particles contained in each. We also determine a family of independent Casimirs in a general configuration.

  13. Risk factors for meningococcal disease in university halls of residence.

    Science.gov (United States)

    Nelson, S. J.; Charlett, A.; Orr, H. J.; Barker, R. M.; Neal, K. R.; Taylor, C.; Monk, P. N.; Evans, M. R.; Stuart, J. M.

    2001-01-01

    A retrospective ecological study was undertaken to identify social and environmental factors associated with increased incidence of meningococcal disease in university halls of residence. A standardized questionnaire was sent to UK universities and colleges of higher education outside London, for distribution to halls containing at least 50 students. Incidence rate ratios of invasive meningococcal disease were obtained for a range of social and environmental variables. Multi-variable Poisson regression analysis identified 3 factors as having a strong association: a high proportion of first year undergraduate residents (P = 0.0008), decreasing smokiness of the hall bar (P Universities should continue to promote awareness of meningococcal disease, encourage vaccination of first year students against serogroup C disease, and where appropriate, take measures to reduce overcrowding. PMID:11349971

  14. Composed planar Hall effect sensors with dual-mode operation

    Science.gov (United States)

    Mor, Vladislav; Roy, Debangsu; Schultz, Moty; Klein, Lior

    2016-02-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make it useful as a switch triggered by magnetic field and as a sensing device with memory, as its mode of operation indicates exposure to a magnetic field larger than a certain threshold without the need to be activated during the exposure itself.

  15. Nonlinear transport of graphene in the quantum Hall regime

    Science.gov (United States)

    Tian, Shibing; Wang, Pengjie; Liu, Xin; Zhu, Junbo; Fu, Hailong; Taniguchi, Takashi; Watanabe, Kenji; Chen, Jian-Hao; Lin, Xi

    2017-03-01

    We have studied the breakdown of the integer quantum Hall (QH) effect with fully broken symmetry, in an ultra-high mobility graphene device sandwiched between two single crystal hexagonal boron nitride substrates. The evolution and stabilities of the QH states are studied quantitatively through the nonlinear transport with dc Hall voltage bias. The mechanism of the QH breakdown in graphene and the movement of the Fermi energy with the electrical Hall field are discussed. This is the first study in which the stabilities of fully symmetry broken QH states are probed all together. Our results raise the possibility that the ν = ±6 states might be a better target for the quantum resistance standard.

  16. μHall chip for sensitive detection of bacteria.

    Science.gov (United States)

    Issadore, David; Chung, Hyun Jung; Chung, Jaehoon; Budin, Ghyslain; Weissleder, Ralph; Lee, Hakho

    2013-09-01

    Sensitive, rapid and phenotype-specific enumeration of pathogens is essential for the diagnosis of infectious disease, monitoring of food chains, and for defense against bioterrorism. Microbiological culture and genotyping, techniques that sensitively and selectively detect bacteria in laboratory settings, have limited application in clinical environments due to high cost, slow response times, and the need for specially trained staff and laboratory infrastructure. To address these challenges, we developed a microfluidic chip-based micro-HallHall) platform capable of measuring single, magnetically tagged bacteria directly in clinical specimens with minimal sample processing. We demonstrated the clinical utility of the μHall chip by enumerating Gram-positive bacteria. The overall detection limit of the system was similar to that of culture tests (~10 bacteria), but the assay time was 50-times faster. This low-cost, single-cell analytical technique is especially well-suited to diagnose infectious diseases in resource-limited clinical settings.

  17. Overview of NASA Iodine Hall Thruster Propulsion System Development

    Science.gov (United States)

    Smith, Timothy D.; Kamhawi, Hani; Hickman, Tyler; Haag, Thomas; Dankanich, John; Polzin, Kurt; Byrne, Lawrence; Szabo, James

    2016-01-01

    NASA is continuing to invest in advancing Hall thruster technologies for implementation in commercial and government missions. The most recent focus has been on increasing the power level for large-scale exploration applications. However, there has also been a similar push to examine applications of electric propulsion for small spacecraft in the range of 300 kg or less. There have been several recent iodine Hall propulsion system development activities performed by the team of the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and Busek Co. Inc. In particular, the work focused on qualification of the Busek 200-W BHT-200-I and development of the 600-W BHT-600-I systems. This paper discusses the current status of iodine Hall propulsion system developments along with supporting technology development efforts.

  18. Hall coefficient of insulating n-type CdSe

    Energy Technology Data Exchange (ETDEWEB)

    Roy, A.; Levy, M.; Guo, X.M.; Sarachik, M.P.; Ledesma, R.; Isaacs, L.L.

    1989-05-15

    We report measurements of the conductivity and Hall coefficient of insulating n-type CdSe with dopant concentrations near the critical concentration for the metal-insulator transition. In the temperature range 1.2--4.2 K, where the resistivity is consistent with variable-range hopping, the Hall coefficient is finite and observable and follows an analogous temperature dependence, R/sub H//similar to/exp(K/sub H/(T/sub 0//T)/sup n/). We find n<1, so that the observed Hall coefficient is not due to carriers activated to extended states; the data are consistent instead with an exponent n = 1/4 or 1/2. We compare this result with previous experiments and with current theory.

  19. Non-Abelian 3d Bosonization and Quantum Hall States

    CERN Document Server

    Radicevic, Djordje; Turner, Carl

    2016-01-01

    Bosonization dualities relate two different Chern-Simons-matter theories, with bosonic matter on one side replaced by fermionic matter on the other. We first describe a more general class of non-Abelian bosonization dualities. We then explore the non-relativistic physics of these theories in the quantum Hall regime. The bosonic theory lies in a condensed phase and admits vortices which are known to form a non-Abelian quantum Hall state. We ask how this same physics arises in the fermionic theory. We find that a condensed boson corresponds to a fully filled Landau level of fermions, while bosonic vortices map to fermionic holes. We confirm that the ground state of the two theories is indeed described by the same quantum Hall wavefunction.

  20. Carl Gustav Jung and Granville Stanley Hall on Religious Experience.

    Science.gov (United States)

    Kim, Chae Young

    2016-08-01

    Granville Stanley Hall (1844-1924) with William James (1842-1910) is the key founder of psychology of religion movement and the first American experimental or genetic psychologist, and Carl Gustav Jung (1875-1961) is the founder of the analytical psychology concerned sympathetically about the religious dimension rooted in the human subject. Their fundamental works are mutually connected. Among other things, both Hall and Jung were deeply interested in how the study of religious experience is indispensable for the depth understanding of human subject. Nevertheless, except for the slight indication, this common interest between them has not yet been examined in academic research paper. So this paper aims to articulate preliminary evidence of affinities focusing on the locus and its function of the inner deep psychic dimension as the religious in the work of Hall and Jung.

  1. The spin Hall effect of light in moving medium

    Science.gov (United States)

    Li, Hehe; Li, Xinzhong; Wang, Jingge

    2017-01-01

    In this paper, we investigate the spin Hall effect of light in moving inhomogeneous medium using the Gordon metric and the Maxwell’s equations in the gravitational field. Light experiences a moving medium as a gravitational field by means of the Gordon metric. It is shown that the spin Hall effect of light is modified by the motion of medium, and the deflection of the ray trajectory is dependent on the polarization and the motion of the medium. It is interesting that there is no coupling of the spin angular momentum of light and the effective gravitational field when the medium is moving along the direction of the gradient ∇n(r). The results provide a potential method for controlling the spin Hall effect of light in medium.

  2. A Simulation Study of Hall Effect on Double Tearing Modes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chenglong; MA Zhiwei; DONG Jiaqi

    2008-01-01

    A Hall magnetohydrodynamics (MHD) simulation is carried out to study the dy-namic process of double tearing mode. The results indicated that the growth rates in the earlier nonlinear and transition phases agree with the previous results. With further development of reconnection, the current sheet thickness is much smaller than the ion inertia length, which leads to a strong influence of the Hall effects. As a result, the reconnection in the late nonlinear phase exhibits an explosive nature with a time scale nearly independent of resistivity. A localized and severely intensified current density is observed and the maximum kinetic energy is over one order of magnitude higher in Hall MHD than that in resistive MHD.

  3. Quantum anomalous Hall effect in magnetic insulator heterostructure.

    Science.gov (United States)

    Xu, Gang; Wang, Jing; Felser, Claudia; Qi, Xiao-Liang; Zhang, Shou-Cheng

    2015-03-11

    On the basis of ab initio calculations, we predict that a monolayer of Cr-doped (Bi,Sb)2Te3 and GdI2 heterostructure is a quantum anomalous Hall insulator with a nontrivial band gap up to 38 meV. The principle behind our prediction is that the band inversion between two topologically trivial ferromagnetic insulators can result in a nonzero Chern number, which offers a better way to realize the quantum anomalous Hall state without random magnetic doping. In addition, a simple effective model is presented to describe the basic mechanism of spin polarized band inversion in this system. Moreover, we predict that 3D quantum anomalous Hall insulator could be realized in (Bi2/3Cr1/3)2Te3 /GdI2 superlattice.

  4. Plasma Diagnostic and Performance of a Permanent Magnet Hall Thruster

    CERN Document Server

    Ferreira, J L; Rego, I D S; Ferreira, I S; Ferreira, Jose Leonardo; Souza, Joao Henrique Campos De; Rego, Israel Da Silveira; Ferreira, Ivan Soares

    2004-01-01

    Electric propulsion is now a sucessfull method for primary propulsion of deep space long duration missions and for geosyncronous satellite attitude control. Closed Drift Plasma Thruster, so called Hall Thruster or SPT (stationary plasma thruster) were primarily conceived in USSR (the ancient Soviet Union) and now it is been developed by space agencies, space research institutes and industries in several countries such as France, USA, Israel, Russian Federation and Brazil. In this work, we show plasma characteristics and performance of a Hall Thruster designed with an innovative concept which uses an array of permanent magnets, instead of an eletromagnet, to produce a radial magnetic field inside its cylindrical plasma drift channel. Within this new concept, we expect to develop a Hall Thruster within power consuption that will scale up to small and medium size satellites. A plasma density and temperature space profiles inside and outside the thruster channel will be shown. Space plasma potential, ion temperat...

  5. Diaphragm Effect of Steel Space Roof Systems in Hall Structures

    Directory of Open Access Journals (Sweden)

    Mehmet FENKLİ

    2015-09-01

    Full Text Available Hall structures have been used widely for different purposes. They have are reinforced concrete frames and shear wall with steel space roof systems. Earthquake response of hall structures is different from building type structures. One of the most critical nodes is diaphragm effect of steel space roof on earthquake response of hall structures. Diaphragm effect is depending on lateral stiffness capacity of steel space roof system. Lateral stiffness of steel space roof system is related to modulation geometry, support conditions, selected sections and system geometry. In current paper, three representative models which are commonly used in Turkey were taken in to account for investigation. Results of numerical tests were present comparatively

  6. Composed planar Hall effect sensors with dual-mode operation

    Directory of Open Access Journals (Sweden)

    Vladislav Mor

    2016-02-01

    Full Text Available We present a composed planar Hall effect sensor with two modes of operation: (a an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make it useful as a switch triggered by magnetic field and as a sensing device with memory, as its mode of operation indicates exposure to a magnetic field larger than a certain threshold without the need to be activated during the exposure itself.

  7. The transport mechanism of the integer quantum Hall effect

    CERN Document Server

    LiMing, W

    2016-01-01

    The integer quantum Hall effect is analysed using a transport mechanism with a semi-classic wave packages of electrons in this paper. A strong magnetic field perpendicular to a slab separates the electron current into two branches with opposite wave vectors $({\\it k})$ and locating at the two edges of the slab, respectively, along the current. In this case back scattering of electrons ($k\\rightarrow -k$) is prohibited by the separation of electron currents. Thus the slab exhibits zero longitudinal resistance and plateaus of Hall resistance. When the Fermi level is scanning over a Landau level when the magnetic field increases, however, the electron waves locate around the central axis of the slab and overlap each other thus back scattering of electrons takes place frequently. Then longitudinal resistance appears and the Hall resistance goes up from one plateau to a new plateau.

  8. Jerusalem: City of Dreams, City of Sorrows

    Science.gov (United States)

    Ricks, Thomas

    2011-01-01

    Jerusalem is more than an intriguing global historical city; it is a classroom for liberal learning and international understanding. It had never been a city of one language, one religion and one culture. Looking at the origins of Jerusalem's name indicates its international and multicultural nature. While Israelis designate Jerusalem as their…

  9. City Car = The City Car / Andres Sevtshuk

    Index Scriptorium Estoniae

    Sevtshuk, Andres, 1981-

    2008-01-01

    Massachusettsi Tehnoloogiainstituudi (MIT) meedialaboratooriumi juures tegutseva Targa Linna Grupi (Smart City Group) ja General Motorsi koostööna sündinud kaheistmelisest linnasõbralikust elektriautost City Car. Nimetatud töögrupi liikmed (juht William J. Mitchell, töögruppi kuulus A. Sevtshuk Eestist)

  10. City Car = The City Car / Andres Sevtshuk

    Index Scriptorium Estoniae

    Sevtshuk, Andres, 1981-

    2008-01-01

    Massachusettsi Tehnoloogiainstituudi (MIT) meedialaboratooriumi juures tegutseva Targa Linna Grupi (Smart City Group) ja General Motorsi koostööna sündinud kaheistmelisest linnasõbralikust elektriautost City Car. Nimetatud töögrupi liikmed (juht William J. Mitchell, töögruppi kuulus A. Sevtshuk Eestist)

  11. European Cities in the World City Network

    NARCIS (Netherlands)

    P. Taylor (Peter)

    2003-01-01

    textabstractThis is primarily an empirical paper that brings together selected results from the GaWC research programme. The latter studies inter-city relations at a global scale. Empirical research is based upon a model of world city network network formation as a product of the location strategies

  12. Pairing in Luttinger Liquids and Quantum Hall States

    Science.gov (United States)

    Kane, Charles L.; Stern, Ady; Halperin, Bertrand I.

    2017-07-01

    We study spinless electrons in a single-channel quantum wire interacting through attractive interaction, and the quantum Hall states that may be constructed by an array of such wires. For a single wire, the electrons may form two phases, the Luttinger liquid and the strongly paired phase. The Luttinger liquid is gapless to one- and two-electron excitations, while the strongly paired state is gapped to the former and gapless to the latter. In contrast to the case in which the wire is proximity coupled to an external superconductor, for an isolated wire there is no separate phase of a topological, weakly paired superconductor. Rather, this phase is adiabatically connected to the Luttinger liquid phase. The properties of the one-dimensional topological superconductor emerge when the number of channels in the wire becomes large. The quantum Hall states that may be formed by an array of single-channel wires depend on the Landau-level filling factors. For odd-denominator fillings ν =1 /(2 n +1 ), wires at the Luttinger phase form Laughlin states, while wires in the strongly paired phase form a bosonic fractional quantum Hall state of strongly bound pairs at a filling of 1 /(8 n +4 ). The transition between the two is of the universality class of Ising transitions in three dimensions. For even-denominator fractions ν =1 /2 n , the two single-wire phases translate into four quantum Hall states. Two of those states are bosonic fractional quantum Hall states of weakly and strongly bound pairs of electrons. The other two are non-Abelian quantum Hall states, which originate from coupling wires close to their critical point. One of these non-Abelian states is the Moore-Read state. The transitions between all of these states are of the universality class of Majorana transitions. We point out some of the properties that characterize the different phases and the phase transitions.

  13. Hall Effect–Mediated Magnetic Flux Transport in Protoplanetary Disks

    Science.gov (United States)

    Bai, Xue-Ning; Stone, James M.

    2017-02-01

    The global evolution of protoplanetary disks (PPDs) has recently been shown to be largely controlled by the amount of poloidal magnetic flux threading the disk. The amount of magnetic flux must also coevolve with the disk, as a result of magnetic flux transport, a process that is poorly understood. In weakly ionized gas as in PPDs, magnetic flux is largely frozen in the electron fluid, except when resistivity is large. When the disk is largely laminar, we show that the relative drift between the electrons and ions (the Hall drift), and the ions and neutral fluids (ambipolar drift) can play a dominant role on the transport of magnetic flux. Using two-dimensional simulations that incorporate the Hall effect and ambipolar diffusion (AD) with prescribed diffusivities, we show that when large-scale poloidal field is aligned with disk rotation, the Hall effect rapidly drags magnetic flux inward at the midplane region, while it slowly pushes flux outward above/below the midplane. This leads to a highly radially elongated field configuration as a global manifestation of the Hall-shear instability. This field configuration further promotes rapid outward flux transport by AD at the midplane, leading to instability saturation. In quasi-steady state, magnetic flux is transported outward at approximately the same rate at all heights, and the rate is comparable to the Hall-free case. For anti-aligned field polarity, the Hall effect consistently transports magnetic flux outward, leading to a largely vertical field configuration in the midplane region. The field lines in the upper layer first bend radially inward and then outward to launch a disk wind. Overall, the net rate of outward flux transport is about twice as fast as that of the aligned case. In addition, the rate of flux transport increases with increasing disk magnetization. The absolute rate of transport is sensitive to disk microphysics, which remains to be explored in future studies.

  14. An Important Forum for the Future of the World's Rivers: The 8th International Riversymposium in Brisbane%未来世界河流的重要讨论会--第8届国际河流研讨会在布里斯班召开

    Institute of Scientific and Technical Information of China (English)

    姚鲁烽

    2005-01-01

    @@ The 8th International Riversymposium was held in Brisbane, Australia on 6-9 September 2005. The International Riversymposium is an integral part of Brisbane's annual broadbased cultural event.The Queensland Government is a foundation partner of the International River Foundation, formed to secure the future of the International and National Thiess Riverprize. The theme of symposium in this year is "Water and Food Security- Rivers in a Global Context" ( www.riversymposium.com ).The Riversymposium provides a global forum which aims to make a difference to the declining state of rivers and waterways globally. Its strength lies in the breadth of its challenging program content of important keynote presentations and case studies of rivers in crisis, attracting a diverse range of national and international delegates. Some 450 scientists from 38 countries attended this conference, and about 100 papers were presented on the symposium in 2005.

  15. Suitable reverberation time for halls for rock and pop music

    DEFF Research Database (Denmark)

    Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian

    2010-01-01

    The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark...... and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers as expert listeners. Correlations between the measurements show that clarity, including bass frequencies down to 63 Hz, is important for the general impression of the acoustics of the hall...

  16. Anomalous Hall Effect in a 2D Rashba Ferromagnet.

    Science.gov (United States)

    Ado, I A; Dmitriev, I A; Ostrovsky, P M; Titov, M

    2016-07-22

    Skew scattering on rare impurity configurations is shown to dominate the anomalous Hall effect in a 2D Rashba ferromagnet. The mechanism originates in scattering on rare impurity pairs separated by distances of the order of the Fermi wavelength. The corresponding theoretical description goes beyond the conventional noncrossing approximation. The mechanism provides the only contribution to the anomalous Hall conductivity in the most relevant metallic regime and strongly modifies previously obtained results for lower energies in the leading order with respect to impurity strength.

  17. Quantum inferring acausal structures and the Monty Hall problem

    Science.gov (United States)

    Kurzyk, Dariusz; Glos, Adam

    2016-09-01

    This paper presents a quantum version of the Monty Hall problem based upon the quantum inferring acausal structures, which can be identified with generalization of Bayesian networks. Considered structures are expressed in formalism of quantum information theory, where density operators are identified with quantum generalization of probability distributions. Conditional relations between quantum counterpart of random variables are described by quantum conditional operators. Presented quantum inferring structures are used to construct a model inspired by scenario of well-known Monty Hall game, where we show the differences between classical and quantum Bayesian reasoning.

  18. Magnetic noise measurements using cross-correlated Hall sensor arrays

    Science.gov (United States)

    Jung, G.; Ocio, M.; Paltiel, Y.; Shtrikman, H.; Zeldov, E.

    2001-01-01

    An experimental technique for measuring magnetic fluctuations by means of a double-layer Hall sensor array is described. The technique relies on cross-correlating Hall signals from two independent sensors positioned one above the other in two separate two-dimensional-electron-gas layers of a GaAs/AlGaAs heterostructure. The effectiveness of the technique is demonstrated by a reduction of the magnitude of the background noise floor of the correlated sensors with respect to the noise level of the best single sensor.

  19. Quantum anomalous Hall effect in topological insulator memory

    Energy Technology Data Exchange (ETDEWEB)

    Jalil, Mansoor B. A., E-mail: elembaj@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore 117576 (Singapore); Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); Tan, S. G. [Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore 117576 (Singapore); Siu, Z. B. [Data Storage Institute, Agency for Science, Technology and Research A*STAR, DSI Building, 5 Engineering Drive 1, Singapore, Singapore 117608 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (Singapore)

    2015-05-07

    We theoretically investigate the quantum anomalous Hall effect (QAHE) in a magnetically coupled three-dimensional-topological insulator (3D-TI) system. We apply the generalized spin-orbit coupling Hamiltonian to obtain the Hall conductivity σ{sup xy} of the system. The underlying topology of the QAHE phenomenon is then analyzed to show the quantization of σ{sup xy} and its relation to the Berry phase of the system. Finally, we analyze the feasibility of utilizing σ{sup xy} as a memory read-out in a 3D-TI based memory at finite temperatures, with comparison to known magnetically doped 3D-TIs.

  20. Background Pressure Effects on Krypton Hall Effect Thruster Internal Acceleration

    Science.gov (United States)

    2013-08-01

    krypton operation of the BHT -600 at the conditions in Table 2 yields a thrust of 22.4 mN corresponding to an anode efficiency of approximately 31...measurement volume is ap- proximately 500 µm diameter by 1 mm length.   Measurement Domain Figure 3 shows a cross-section of the BHT -600 Hall effect...of the BHT -600 Hall effect thruster with measurement volume shown in red. All dimensions are given in mm.     tion of the transition

  1. Few-body, hyperspherical treatment of the quantum Hall effect

    Directory of Open Access Journals (Sweden)

    Wooten R. E.

    2016-01-01

    Full Text Available The quantum Hall effect arises from the quantum behavior of two-dimensional, strongly-interacting electrons exposed to a strong, perpendicular magnetic field [1, 2]. Conventionally treated from a many-body perspective, we instead treat the system from the few-body perspective using collective coordinates and the hyperspherical adiabatic technique developed originally for atomic systems [3]. The grand angular momentum K from K-harmonic few-body theory, is shown to be an approximate good collective quantum number in this system, and is shown to correlate with known fractional quantum Hall (FQH states at experimentally observed filling factors.

  2. Phonon Hall effect in four-terminal nano-junctions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lifa; Wang Jiansheng; Li Baowen [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, 117546 Singapore (Singapore)], E-mail: phylibw@nus.edu.sg

    2009-11-15

    Using an exact nonequilibrium Green's function formulation, the phonon Hall effect (PHE) for paramagnetic dielectrics is studied in a nanoscale four-terminal device setting. The temperature difference in the transverse direction of the heat current is calculated for two-dimensional models with the magnetic field perpendicular to the plane. We find that there is a PHE in nanoscale paramagnetic dielectrics, the magnitude of which is comparable to millimeter scale experiments. If the dynamic matrix of the system satisfies mirror reflection symmetry, the PHE disappears. The Hall temperature difference changes sign if the magnetic field is sufficiently large or if the size increases.

  3. Color Ferromagnetism and Quantum Hall states in Quark Matter

    CERN Document Server

    Iwazaki, A

    2003-01-01

    We discuss a possibility of the presence of a stable color ferromagnetic state in SU(2) gauge theory of quark matter; a color magnetic field is spontaneously generated due tothe gluon's dynamics. The state arises between the hadronic state and the color superconducting state when the density of quarks is varied. Although the state has been known to have unstable modes, we show that unstable modes form quantum Hall states, in which the instability disappears. Namely, the quark matter possesses a stable phase with the ferromagnetic state and the quantum Hall state of gluons.

  4. Inverse spin Hall effect in a closed loop circuit

    Energy Technology Data Exchange (ETDEWEB)

    Omori, Y.; Auvray, F.; Wakamura, T.; Niimi, Y., E-mail: niimi@issp.u-tokyo.ac.jp [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8581 (Japan); Fert, A. [Unité Mixte de Physique CNRS/Thales, 91767 Palaiseau France associée à l' Université de Paris-Sud, 91405 Orsay (France); Otani, Y. [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8581 (Japan); RIKEN-CEMS, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2014-06-16

    We present measurements of inverse spin Hall effects (ISHEs), in which the conversion of a spin current into a charge current via the ISHE is detected not as a voltage in a standard open circuit but directly as the charge current generated in a closed loop. The method is applied to the ISHEs of Bi-doped Cu and Pt. The derived expression of ISHE for the loop structure can relate the charge current flowing into the loop to the spin Hall angle of the SHE material and the resistance of the loop.

  5. Observation of the Spin Hall Effect in Semiconductors

    Science.gov (United States)

    Kato, Y. K.; Myers, R. C.; Gossard, A. C.; Awschalom, D. D.

    2004-12-01

    Electrically induced electron-spin polarization near the edges of a semiconductor channel was detected and imaged with the use of Kerr rotation microscopy. The polarization is out-of-plane and has opposite sign for the two edges, consistent with the predictions of the spin Hall effect. Measurements of unstrained gallium arsenide and strained indium gallium arsenide samples reveal that strain modifies spin accumulation at zero magnetic field. A weak dependence on crystal orientation for the strained samples suggests that the mechanism is the extrinsic spin Hall effect.

  6. Porting a Hall MHD Code to a Graphic Processing Unit

    Science.gov (United States)

    Dorelli, John C.

    2011-01-01

    We present our experience porting a Hall MHD code to a Graphics Processing Unit (GPU). The code is a 2nd order accurate MUSCL-Hancock scheme which makes use of an HLL Riemann solver to compute numerical fluxes and second-order finite differences to compute the Hall contribution to the electric field. The divergence of the magnetic field is controlled with Dedner?s hyperbolic divergence cleaning method. Preliminary benchmark tests indicate a speedup (relative to a single Nehalem core) of 58x for a double precision calculation. We discuss scaling issues which arise when distributing work across multiple GPUs in a CPU-GPU cluster.

  7. The Quantum Hall Effect in Supersymmetric Chern-Simons Theories

    CERN Document Server

    Tong, David

    2015-01-01

    In d=2+1 dimensions, there exist gauge theories which are supersymmetric but non-relativistic. We solve the simplest U(1) gauge theory in this class and show that the low-energy physics is that of the fractional quantum Hall effect, with ground states given by the Laughlin wavefunctions. We do this by quantising the vortices and relating them to the quantum Hall matrix model. We further construct coherent state representations of the excitations of vortices. These are quasi-holes. By an explicit computation of the Berry phase, without resorting to a plasma analogy, we show that these excitations have fractional charge and spin.

  8. Stability of Hall equilibria in neutron star crusts

    OpenAIRE

    Marchant P.; Reisenegger A.; Valdivia J.A.; Hoyos J.H.

    2014-01-01

    In the solid crusts of neutron stars, the advection of the magnetic field by the current-carrying electrons, an effect known as Hall drift, should play a very important role as the ions remain essentially fixed (as long as the solid does not break). Although Hall drift preserves the magnetic field energy, it has been argued that it may drive a turbulent cascade to scales at which Ohmic dissipation becomes effective, allowing a much faster decay in objects with very strong fields. On the other...

  9. Fractional quantum Hall states of bosons on cones

    CERN Document Server

    Wu, Ying-Hai; Sreejith, G J

    2016-01-01

    Motivated by a recent experiment which synthesizes Landau levels for photons on cones (Schine {\\em et al.}, arXiv: 1511.07381), and more generally the interest in understanding gravitational responses of quantum Hall systems, we study fractional quantum Hall states of bosons on cones. We construct several trial wave functions and compare them with exact diagonalization results. The tip of a cone is a localized geometrical defect with singular curvature around which excessive charges accumulate. We study the density profiles of some states on cones and show that the excessive charges agree with analytical predictions.

  10. Magnetar Outbursts from Avalanches of Hall Waves and Crustal Failures

    CERN Document Server

    Li, Xinyu; Belovorodov, Andrei M

    2016-01-01

    We explore the interaction between Hall waves and mechanical failures inside a magnetar crust, using detailed one-dimentional models that consider temperature-sensitive plastic flow, heat transport and cooling by neutrino emission, as well as the coupling of the crustal motion to the magnetosphere. We find that the dynamics is enriched and accelerated by the fast, short-wavelength Hall waves that are emitted by each failure. The waves propagate and cause failures elsewhere, triggering avalanches. We argue that these avalanches are the likely sources of outbursts in transient magnetars.

  11. Spin-Hall nano-oscillator: A micromagnetic study

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, A.; Azzerboni, B.; Finocchio, G. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy); Carpentieri, M. [Department of Electrical and Information Engineering, Politecnico of Bari, via E. Orabona 4, I-70125 Bari (Italy); Laudani, A. [Department of Engineering, University of Roma Tre, via V. Volterra 62, I-00146 Roma (Italy); Gubbiotti, G. [Istituto Officina dei Materiali del CNR (CNR-IOM), Unità di Perugia c/o Dipartimento di Fisica e Geologia, Via A. Pascoli, 06123 Perugia (Italy)

    2014-07-28

    This Letter studies the dynamical behavior of spin-Hall nanoscillators from a micromagnetic point of view. The model parameters have been identified by reproducing recent experimental data quantitatively. Our results indicate that a strongly localized mode is observed for in-plane bias fields such as in the experiments, while predict the excitation of an asymmetric propagating mode for large enough out-of plane bias field similarly to what observed in spin-torque nanocontact oscillators. Our findings show that spin-Hall nanoscillators can find application as spin-wave emitters for magnonic applications where spin waves are used for transmission and processing information on nanoscale.

  12. Moiré assisted fractional quantum Hall state spectroscopy

    Science.gov (United States)

    Wu, Fengcheng; MacDonald, A. H.

    2016-12-01

    Intra-Landau level excitations in the fractional quantum Hall regime are not accessible via optical absorption measurements. We point out that optical probes are enabled by the periodic potentials produced by a moiré pattern. Our observation is motivated by the recent observations of fractional quantum Hall incompressible states in moiré-patterned graphene on a hexagonal boron nitride substrate, and is theoretically based on f -sum rule considerations supplemented by a perturbative analysis of the influence of the moiré potential on many-body states.

  13. Geometric phase gradient and spin Hall effect of light

    Science.gov (United States)

    Ling, Xiaohui; Zhou, Xinxing; Qiu, Cheng-Wei

    2016-10-01

    The spin Hall effect (SHE) of light originates from the spin-orbit interaction, which can be explained in terms of two geometric phases: the Rytov-Vladimirskii-Berry phase and the Pancharatnam-Berry phase. Here we present a unified theoretical description of the SHE based on the two types of geometric phase gradients, and observe experimentally the SHE in structured dielectric metasurfaces induced by the PB phase. Unlike the weak real-space spin-Hall shift induced by the SRB phase occurring at interfacial reflection/refraction, the observed SHE occurs in momentum space is large enough to be measured directly.

  14. Inverse spin Hall effect in Pt/(Ga,Mn)As

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, H. [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Chen, L. [WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Chang, H. W. [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Ohno, H.; Matsukura, F., E-mail: f-matsu@wpi-aimr.tohoku.ac.jp [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2015-06-01

    We investigate dc voltages under ferromagnetic resonance in a Pt/(Ga,Mn)As bilayer structure. A part of the observed dc voltage is shown to originate from the inverse spin Hall effect. The sign of the inverse spin Hall voltage is the same as that in Py/Pt bilayer structure, even though the stacking order of ferromagnetic and nonmagnetic layers is opposite to each other. The spin mixing conductance at the Pt/(Ga,Mn)As interface is determined to be of the order of 10{sup 19 }m{sup −2}, which is about ten times greater than that of (Ga,Mn)As/p-GaAs.

  15. Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers

    KAUST Repository

    Manchon, Aurelien

    2017-01-01

    We investigate the emergence of spin Hall magnetoresistance in a magnetic bilayer composed of a normal metal adjacent to an antiferromagnet. Based on a recently derived drift diffusion equation, we show that the resistance of the bilayer depends on the relative angle between the direction transverse to the current flow and the Néel order parameter. While this effect presents striking similarities with the spin Hall magnetoresistance recently reported in ferromagnetic bilayers, its physical origin is attributed to the anisotropic spin relaxation of itinerant spins in the antiferromagnet.

  16. A Crowded City

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Over 4 million vehicles on road challenge Beijing’s city management Beijing, the city once known as the kingdom of bicycles, has become clogged with automobiles, the Beijing Municipal Government Publicity Office said on December 18.

  17. Build a Green City

    Institute of Scientific and Technical Information of China (English)

    XUYING; HAOXUE

    2005-01-01

    MA'ANSHAN,dubbed ""City of Iron and Steel,""is on the south bank of the Yangtze River in eastern Anhui Province, bordering Jiangsu Province. One of the city's most impressive features is its clean environment.

  18. EU Smart City Governance

    National Research Council Canada - National Science Library

    Carmela Gargiulo; Valentina Pinto; Floriana Zucaro

    2013-01-01

    .... The paper wants to outline which future EU draws for the city, through an integrated and contextual reading of addresses and strategies contained in the last documents, a future often suggested as Smart City...

  19. Hall Effect Thruster for High Power Solar Electric Propulsion Technology Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek proposes to develop a flight version of a high power Hall Effect thruster. While numerous high power Hall Effect thrusters have been demonstrated in the...

  20. Recent multi-purpose hall designs in Denmark with physically variable acoustics

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1999-01-01

    ) and so clarity (C), but also the strength parameter (G) could be varied in a favorable direction in view of the prescribed uses of the halls. The hall with variable absorption is the assembly hall in the new extension to the Royal Library in Copenhagen to open in fall 1999. This hall will seat 600 people...... and be used for chamber music concerts, symphony orchestra rehearsals, and amplified speech. For the latter two functions, a reduction in G along with reduction in T was considered favorable. The hall with variable volume is the recently opened Esbjerg Musikhus seating 1100 and equipped with a full stage...... house. This hall is used for symphonic concerts and musicals as well as drama and conferences. In this hall, maintaining or even increasing G along with a reduction in T is advantageous, especially in the drama theatre mode. The paper will describe the design of these two halls along with acoustic...