Miele, Eleanor; Shanley, Deborah; Steiner, Robert V.
2010-01-01
This article describes the evolution of a partnership between Brooklyn College (BC) of the City University of New York (CUNY) and the American Museum of Natural History (AMNH) that ultimately resulted in the formal incorporation of the museum's online Seminars on Science (SoS) courses into master's degree programs at Brooklyn College for teachers…
The Other Hall Effect: College Board Physics
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…
David J. Nowak; Daniel E. Crane; Jack C. Stevens; Myriam Ibarra
2002-01-01
An assessment of trees in Brooklyn, New York, reveal that this borough has approximately 610,000 trees with canopies that cover 11.4 percent of the area. The most common trees are estimated to be tree of heaven, white mulberry, black locust, Norway maple and black cherry. Brooklyn's trees currently store approximately 172,000 metric tons of carbon with an...
Gilgour, Joseph G.
2012-01-01
Community colleges in the United States have long been known as institutions of equal opportunity and affordable education. One facet of student life appearing at more and more community colleges is the addition of residence halls. Still, the number of community colleges with on-campus living is relatively small, and for the campuses with…
Residence Hall Room Type and Alcohol Use among College Students Living on Campus
Cross, Jennifer E.; Zimmerman, Don; O'Grady, Megan A.
2009-01-01
The objectives were to explore the relation between the built environment of residence halls and the alcohol use of college students living on campus from the perspective of the theory of routine activity. This exploratory study examined data from two samples on one college campus. Online surveys assessed alcohol use, attitudes toward alcohol use,…
Sussman, Herbert M.
1977-01-01
A retrospective look at how severe budget reduction during the last two years affected New York City Community College, and at the difficult decisions made and issues considered in retrenchment of services and staff. (JG)
The Virtual Core: Distance Learning, Brooklyn Style
Barbra Higginbotham
2001-04-01
Full Text Available
頁次：98-105
Educators nation-wide are experimenting with the use of technology to enhance undergraduates' academic success. Brooklyn College, part of the City University of New York (CUNY, has developed a sequence of general education courses that join one-half class time with one-half Web-based instruction--a fresh, inventive model that gives students the best aspects of both the traditional and the online educational experience. As a result, Brooklyn's core curriculum has become more inviting, effective, and activity-based. The grant that supported this project was written by Dr. Barbra Buckner Higginbotham, Chief Librarian and Executive Director of Academic Information Technologies, and this major faculty training and development effort is occurring under the aegis of the Library.
Boekeloo, Bradley O.; Bush, Elizabeth N.; Novik, Melinda G.
2009-01-01
Objective: The authors examined the secondhand effects among college freshmen of others' alcohol use and related student characteristics, and perceptions about residence hallmates. Participants: The authors surveyed 509 incoming freshmen residing in predominantly freshman residence halls. Methods: The authors administered a Web-based survey 2…
77 FR 21436 - Safety Zone, East River, Brooklyn Bridge Scaffolding Repair, Brooklyn, NY
2012-04-10
... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, East River, Brooklyn Bridge Scaffolding... in the vicinity of the Brooklyn Bridge where damaged corrugated metal scaffoldings and loosely... and their occupants transiting the East River in the vicinity of the Brooklyn Bridge. Therefore, a...
Jumping from the Brooklyn Bridge.
Kurtz, R J; Pizzi, W F; Richman, H; Tiefenbrun, J
1987-07-01
In an attempt to identify factors contributing to survival of free fall and impact, we evaluated the records of four patients who survived a jump from the Brooklyn Bridge into the East River in New York Harbor between 1977 and 1985. All four patients were male and ranged in age from 22 to 67 years. They had free falls of between 41.0 and 48.8 meters. All of the patients were brought to the hospital within 24 minutes of entering the water. Three of the four had emergency surgical treatment and the fourth patient had only minor injuries. All four patients survived the suicide attempts. The length of the hospital stay ranged from two to 26 days.
Cullum, Jerry; Harton, Helen C
2007-10-01
This article investigates cultural evolution in four college residence halls. Up to four attitude surveys were completed by 1,252 participants in a semester. Participants' attitudes became more similar to those living closest to them over time as a result of localized interpersonal influence processes. Correlations between attitudes also increased with time as these cultural attributes grew increasingly interdependent. These basic findings support the predictions of dynamic social impact theory. However, these effects were stronger for more important issues even when controlling for discussion. These findings are likely the result of (a) individual-level selective attention to personally important information, (b) greater attitude-behavior consistency for important issues, and/or (c) nonlinear attitude change processes for important issues as suggested by the catastrophe theory of attitudes. These results suggest that intrapsychic processes as well as interpersonal processes contribute to cultural evolution.
Johnson, Kamauru
2016-01-01
The building that houses Brooklyn Friends School's (New York) preschool, lower, and middle divisions stands on a quiet one-way street in an otherwise bustling downtown Brooklyn business district. After most students head home for the day, others come to the school to participate in the Horizons Program. The Horizons Program at Brooklyn Friends…
Brooklyn Dreams: My Life in Public Education
Nieto, Sonia
2015-01-01
In "Brooklyn Dreams," Sonia Nieto--one of the leading authors and teachers in the field of multicultural education--looks back on her formative experiences as a student, activist, and educator, and shows how they reflect and illuminate the themes of her life's work. Nieto offers a poignant account of her childhood and the complexities of…
A New Definition in Atlanta: Q&A with Beverly Hall
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…
Peterson, Sharon; Duncan, Diana Poovey; Null, Dawn Bloyd; Roth, Sara Long; Gill, Lynn
2010-01-01
Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students' perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18-23) completed pre-I and post-I surveys.…
Peterson, Sharon; Duncan, Diana Poovey; Null, Dawn Bloyd; Roth, Sara Long; Gill, Lynn
2010-01-01
Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students' perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18-23) completed pre-I and post-I surveys.…
The Antibureaucrat: Mary Graham--Brooklyn Public Library, NY
Library Journal, 2004
2004-01-01
It is tough to make the staff of a large, highly centralized urban library system believe they should make their own decisions and even take risks--all to serve their community better. But that is what Mary Graham has achieved as Brooklyn Public Library's director of the Office of Neighborhood Services. A study of Brooklyn Public Library (BPL) in…
High-Society Framing: The Brooklyn Eagle and the Popularity of Twilight Sleep in Brooklyn.
Johnson, Bethany; Quinlan, Margaret M
2017-01-01
Twilight Sleep (TS) is an obstetric intervention during which a laboring woman enters a semiconscious state via injection. TS received enthusiastic support in Brooklyn, NY, in The Brooklyn Eagle (TBE) newspaper between 1914 and 1918. The purpose of this article is to analyze the framing of TS in TBE as the most popular obstetric intervention among wealthy, White socialites in Brooklyn during the period. The coverage in TBE prompted a nearly universally positive perception of TS among the newspaper's wider readership. After extensive historiographical research and rhetorical analysis of newspaper coverage of TS in TBE, we discovered a form of framing we call "high-society framing," rooted in both wealth and notoriety. We discuss four possible effects of high-society framing: The first is the ability of high-society framing to attract or repel the public regarding a health care issue, and the second is the impact of high-society framing on public perception of medical interventions, procedures, or pharmaceuticals. A third possible effect of high-society framing is that it can alter notions of necessity, and a fourth is that high-society framing can elicit a tacit acceptance of medical interventions, procedures, and pharmaceuticals, thus obfuscating risk. Finally, we argue that high-society framing has implications for the discussion of health care in present-day mediated discourses.
76 FR 6728 - Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn, NY
2011-02-08
... the Verrazano Bridge Brooklyn tower. Entry into the proposed safety zone by any person or vessel will... southeast of the Verrazano Bridge Brooklyn tower. (b) Effective date. This safety zone is effective on July... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn...
76 FR 31233 - Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn, NY
2011-05-31
... 83), approximately 70-yards southeast of the Verrazano Bridge Brooklyn tower. Entry into the safety...'' N, 074 02'14'' W (NAD 83), approximately 70-yards southeast of the Verrazano Bridge Brooklyn tower... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn...
76 FR 4529 - Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn, NY
2011-01-26
... 02'14'' W (NAD 83), approximately 70 yards southeast of the Verrazano Bridge Brooklyn tower. All... Bridge, Brooklyn, NY. This safety zone will not have a significant economic impact on a substantial...), approximately 70-yards southeast of the Verrazano Bridge Brooklyn tower. (b) Effective period. This regulation...
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…
Solar Hydrogen Fuel Cell Projects at Brooklyn Tech
Fedotov, Alex; Farah, Shadia; Farley, Daithi; Ghani, Naureen; Kuo, Emmy; Aponte, Cecielo; Abrescia, Leo; Kwan, Laiyee; Khan, Ussamah; Khizner, Felix; Yam, Anthony; Sakeeb, Khan; Grey, Daniel; Anika, Zarin; Issa, Fouad; Boussayoud, Chayama; Abdeldayem, Mahmoud; Zhang, Alvin; Chen, Kelin; Chan, Kameron Chuen; Roytman, Viktor; Yee, Michael
2010-01-01
This article describes the projects on solar hydrogen powered vehicles using water as fuel conducted by teams at Brooklyn Technical High School. Their investigations into the pure and applied chemical thermodynamics of hydrogen fuel cells and bio-inspired devices have been consolidated in a new and emerging sub-discipline that they define as solar…
Polytechnic Institute of Brooklyn Agreement 1971-74.
New York Polytechnic Inst., NY.
This document contains the agreement between the Polytechnic Institute of Brooklyn (PIB) and the American Association of University Professors, PIB Chapter, covering the period from September 1, 1971 through May 31, 1974. Covered in the articles of the agreement are sections on appointments, promotions, tenure, teaching load, compensation, leaves…
InnovateEDU, Inc.: Brooklyn Laboratory Charter Schools (LAB)
EDUCAUSE, 2015
2015-01-01
Entrepreneurial learning is the backbone of this Brooklyn charter school network which opened in Fall 2014 to serve grades 6-12, including English language learners and students with disabilities. LAB's academic model combines empirically effective learning practices with innovative implementation strategies, including a blended learning model…
White, Cindy; Kolble, Robin; Carlson, Rebecca; Lipson, Natasha
2005-01-01
Hand hygiene is a key element in preventing the transmission of cold and flu viruses. The authors conducted an experimental-control design study in 4 campus residence halls to determine whether a message campaign about hand hygiene and the availability of gel hand sanitizer could decrease cold and flu illness and school and work absenteeism. Their…
White, Cindy; Kolble, Robin; Carlson, Rebecca; Lipson, Natasha
2005-01-01
Hand hygiene is a key element in preventing the transmission of cold and flu viruses. The authors conducted an experimental-control design study in 4 campus residence halls to determine whether a message campaign about hand hygiene and the availability of gel hand sanitizer could decrease cold and flu illness and school and work absenteeism. Their…
A Conversation with Randy Asher, Principal of New York City's Brooklyn Technical High School
Asher, Randy J.
2016-01-01
This is a conversation with Randy Asher, principal of New York City's Brooklyn Technical High School. Brooklyn Tech is a selective science high school in New York City, founded in 1922 as a school for boys with potential for careers in engineering and applied science. Today, it provides full-time education for both male and female students from…
Testing of the masonry arches of the Brooklyn Bridge approaches
Limaye, Hemant S.
1996-11-01
Diagnostic procedures play an important role in performing a condition survey of a structure. Specialized tests are used during a field survey to supplement visual observations. The tests provide valuable information regarding the internal condition of the structure and quality of the construction materials. The tests also help in determining the extent of damage, if any. Recently, a team of consulting engineers performed a study to determine the remaining capacity of the Brooklyn Bridge approaches for the Department of Transportation, City of New York. Using advanced diagnostic procedures such as impact-echo and flatjack testing, additional information was gathered to assist in the study. Impact-echo testing was helpful in identifying the condition of the brick soffits which were covered with pneumatically- applied concrete, and flatjack testing was useful in determining in-situ compressive strength and compression modulus of the brick masonry. The paper describes the work and the testing results.
Financial planning for district heating: The Brooklyn Navy Yard project: A project report
1984-05-01
Financial planning for the Brooklyn Navy Cogeneration and District Heating Project involved the establishment of three distinct potential markets, a determination of economic feasibility and the development of a financial structure that could accommodate the diverse social objectives of the project and the nature of the markets to be served. The Brooklyn Navy Yard (BNY) is owned by the City of New York (City) and managed by the non-profit Brooklyn Navy Yard Development Corporation for operation as an industrial park. Development of a cogeneration/district heating facility at the Navy Yard was undertaken to meet multiple community and economic development objectives.
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...
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...
“New York and yet not New York”: Reading the Region in Contemporary Brooklyn Fictions
James Peacock
2008-12-01
Full Text Available The article analyzes the depiction of Brooklyn as an urban region in a number of recent American novels, including Lynne Sharon Schwartz’s Leaving Brooklyn and Kitty Burns Florey’s Solos. It argues that Brooklyn is frequently defined in opposition to Manhattan: the former being viewed as the epitome of American ideals of community-in-diversity, the latter as homogenizing, globalizing and obsessed with newness. In a time when regions and communities are frequently regarded as under threat from, amongst other things, globalization and terrorism, it is interesting to examine whether the ideals of diversity and community associated with Brooklyn are based on nostalgic, mythic notions of land and family or are in fact based on superficial signifiers of diversity and a range of consumer choices. The article goes on to argue that the complex interactions between the regional and the global in these novels can be seen as analogous to processes of reading regional texts themselves.
叶常富
2011-01-01
This paper analyzes the colleges or universities＇ mess hall business model and the operating status. To think and explore the process of reformation in the colleges or universities＇ mess hall, there are still some problems, the more prominent three aspects of the problems are included that the management team members of the mess hall is not in place, the health conditions of the mess hall needs to be more stringent rules and regulations management systems are not executed and proposing some practical solutions and measures.%分析高校食堂的经营模式和现状，思考和探索了高校食堂改革过程中存在的问题，从食堂班组人员管理不到位、食堂卫生条件需要更严格、规章制度管理流于形式等三个方面分析较为突出的问题，提出了切实可行的解决方案和措施。
20th Annual Residence Hall Construction Report
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…
19th Annual Residence Hall Construction Report
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…
Retrofitting Garden-Style Apartments in Brooklyn, New York
Nolen, Heather [Steven Winter Associates, Inc., Norwalk, CT (United States); Maxwell, Sean [Steven Winter Associates, Inc., Norwalk, CT (United States); Neri, Robin [Steven Winter Associates, Inc., Norwalk, CT (United States); Grab, Joanna [Steven Winter Associates, Inc., Norwalk, CT (United States)
2016-02-01
This research effort sought to achieve a solution package that yields energy savings greater than 30% over the pre-existing conditions in a minimally intrusive multifamily retrofit project. The Consortium for Advanced Residential Buildings (CARB) partnered with L+M Development Partners, Inc. on a Mitchell-Lama Housing Program project, Marcus Garvey Village, in Brooklyn, NY (Climate Zone 4A). The Mitchell-Lama Housing Program is a form of housing subsidy in the state of New York that provides affordable rental and cooperative housing to moderate- and middle-income families. Marcus Garvey Village was founded in 1975 and contains 625 residential units (ranging from studios to 5-bedroom units) in thirty-two 4-story garden-style apartment structures built with concrete and faced in light brown brick. The single largest challenge for implementation of energy conservation measures at Marcus Garvey was working within occupied spaces. Measures are being implemented in phases to minimize disruption. As of August 2015, the retrofit work is over 50% complete. The wall insulation, sealing of the through wall AC vent, and installation of new oil-filled electric baseboards with advanced controls are conducted at one time, limiting disruption to the living room space. In a similar fashion, the kitchen work is done, then the bathroom. The final selection of energy conservation measures is projected to save 26.5% in source energy with a cost just under $3.7 million and utility bill savings of nearly $480,000 (of an average $1.8 million annual utility cost for the development).
Varsity Hall: The Infirmary at the University of Virginia
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…
... 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 ...
Israel, Benjamin L.; Litwin, Zelda
This progress report covers a 6-month period in the second year of an experimental research project to test the utility of the Edison Responsive Environment Talking Typewriter as a major tool for teaching both initial and remedial reading to educationally disadvantaged youth. Conducted in six schools in Brooklyn, New York, the study included…
78 FR 71546 - Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY
2013-11-29
... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The Coast... Belt Parkway Bridge. This proposed rule would allow the Coast Guard to prohibit all vessel traffic...
Weissman, Evan
2015-01-01
Driven by social and environmental criticism of the neoliberalization of agro-food systems, urban agriculture today enjoys renewed interest throughout the United States as a primary space to engage the politics of food. Using Brooklyn, New York as a case study, I employ mixed qualitative methods to investigate the contradictions that arise in…
The TRUST Partnership: Institutional Impacts at Lehman College
Sloan, Heather; Kelly, Angela M.
2010-01-01
This work explores the institutional impacts at Lehman College, City University of New York, of the Teacher Renewal for Urban Science Teaching (TRUST) Project, a partnership between the American Museum of Natural History and Brooklyn and Lehman Colleges funded by the National Science Foundation. We examine the impact that TRUST had and continues…
Zimbardo, Philip G.
Extensive observations of the pattern of seating by Negro and white college students in the cafeterias of Brooklyn College (1953) and City College of New York (1963 and 1965) revealed consistent isolation of the Negro students. This pattern of social (self) segregation existed within environments which have always been physically integrated and…
Kelleher, Mary E; Swan, Kenneth G; Kelleher, Denis P
2011-06-01
The Fowler position, widely used in surgery and obstetrics for patient placement, marks a fraction of 19th-century Brooklyn surgeon George Ryerson Fowler's prodigious accomplishments. Fowler was a pioneer who refined the appendectomy, performed the first lung decortication, advocated for sterile techniques, introduced first aid in the US Army, and helped start a precursor to Annals of Surgery. His publications include the first US textbook on appendicitis--ironically, the disease that killed him.
Caisson disease during the construction of the Eads and Brooklyn Bridges: A review.
Butler, W P
2004-01-01
The Eads Bridge (St. Louis) and the Brooklyn Bridge (New York City) were testing grounds for caisson construction. These caissons were enormous compressed air boxes used to build riverine piers and abutments anchoring the bridges. Caisson meant faster and cheaper construction, but there was a hidden cost---caisson disease (decompression sickness). Within caissons, workers labored at pressures as high as 55 psig and caisson disease was common. This discourse is a brief history of the caisson, a brief discussion of the illness as viewed in the mid 1800's, and an abbreviated history of the Eads and Brooklyn Bridges. It also provides a detailed description and evaluation of the observations, countermeasures, and recommendations of Dr. Alphonse Jaminet, the Eads Bridge physician, and Dr. Andrew Smith, the Brooklyn Bridge physician, who published reports of their experience in 1871 and 1873, respectively. These and other primary sources permit a detailed examination of early caisson disease and Jaminet's and Smith's thinking also serve as good examples from which to study and learn.
Muir, Gary M; Van Wylen, David G L
2009-01-01
Planning for new science facilities at your institution is an exciting, challenging, and rewarding endeavor. Perhaps most significantly, it also embodies a rare opportunity to provide new infrastructure to support a programmatic vision for the future. Here, we describe St. Olaf's new Regents Hall of Natural and Mathematical Sciences, beginning with an outline of the planning/design process, then an overview of the features of the building - with particular regard to the Neuroscience Program facilities - and finally a discussion of lessons learned. We hope our experiences may benefit those engaged in the facilities planning process at their own institutions.
The Evolution of College Residence Halls in the United States%美国高校宿舍教育的历史分析：宿舍与人才培养
徐波; 苍玉权
2014-01-01
美国高校学生宿舍从早期承担的生活功能、管理功能，到近50年才开拓的教育功能，走过了漫长的历史。殖民时期，受英国牛津剑桥模式的影响，采用住宿学院制，宿舍主要作用是代替父母监督；内战结束后至19世纪后期，受德国大学影响，认为为学生提供宿舍没有意义；19世纪后期至20世纪中期，伴随赠地学院的发展，宿舍建设再次兴起，这个时期宿舍主要作用是为学生提供生活服务；20世纪60年代以后，宿舍教育功能被广泛认可，开始有目的地设计宿舍教育环境，宿舍成为学生课堂教育与非课堂教育的衔接，成为促进学生全面发展的教育资源。%Collegiate housing has been in existence for more than 300 years in the United States. During the early period, American residence halls followed the English residential college model of Oxford and Cambridge with the function of supervision. Between 1850 and the late nineteenth century, influenced by the German university model, residence halls were denounced as inappropriate and a waste of money in American universities. Between the late nineteenth century and the mid-twentieth century, trends in American higher education once again encouraged the construction of residence halls. Since 1960s, to extend learning outside of the classroom, student affairs educators have infused programmatic curriculums and strategic management techniques into the residential experience.
Bollen, Katrien
2012-01-01
On 13 September 1994, a loose collective of Downtown poets known as the Unbearables lined up on the Brooklyn Bridge pedestrian walkway, all the way from Manhattan to Brooklyn. During rush hour, they simultaneously ranted erotic poems in six-minute loops, so that, at least theoretically, "a few words from each reader would have reached each pedestrian's ear, and the whole string of phrases would add up to a single 'stochastic' poem, a different version for each and every passerby" (Bey 1994, n...
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.
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.
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...
General footage ISOLDE experimental hall
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.
Mehrdad, M; Park, H; Ramalingam, K; Fillos, J; Beckmann, K; Deur, A; Chandran, K
2014-01-01
New York City Environmental Protection in conjunction with City College of New York assessed the application of the anammox process in the reject water treatment using a moving bed biofilm reactor (MBBR) located at the 26th Ward wastewater treatment plant, in Brooklyn, NY. The single-stage nitritation/anammox MBBR was seeded with activated sludge and consequently was enriched with its own 'homegrown' anammox bacteria (AMX). Objectives of this study included collection of additional process kinetic and operating data and assessment of the effect of nitrogen loading rates on process performance. The initial target total inorganic nitrogen removal of 70% was limited by the low alkalinity concentration available in the influent reject water. Higher removals were achieved after supplementing the alkalinity by adding sodium hydroxide. Throughout startup and process optimization, quantitative real-time polymerase chain reaction (qPCR) analyses were used for monitoring the relevant species enriched in the biofilm and in the suspension. Maximum nitrogen removal rate was achieved by stimulating the growth of a thick biofilm on the carriers, and controlling the concentration of dissolved oxygen in the bulk flow and the nitrogen loading rates per surface area; all three appear to have contributed in suppressing nitrite-oxidizing bacteria activity while enriching AMX density within the biofilm.
Nonlocal Anomalous Hall Effect
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.
Conducting Wall Hall Thrusters
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.
Nonlocal Anomalous Hall Effect.
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.
F.W. Dobbs-Allsopp
2016-04-01
Full Text Available A collaborative project of the Brooklyn Museum and a number of allied institutions, including Princeton Theological Seminary and West Semitic Research, the Digital Brooklyn Museum Aramaic Papyri (DBMAP is to be both an image-based electronic facsimile edition of the important collection of Aramaic papyri from Elephantine housed at the Brooklyn Museum and an archival resource to support ongoing research on these papyri and the public dissemination of knowledge about them. In the process of building out a (partial prototype of the edition, to serve as a proof of concept, we have discovered little field-specific discussion that might guide our markup decisions. Consequently, here our chief ambition is to initiate such a conversation. After a brief overview of DBMAP, we offer some initial reflection on and assessment of XML markup schemes specifically for Semitic texts from the ancient Near East that comply with TEI, CSE, and MEP guidelines. We take as our example BMAP 3 (=TAD B3.4 and we focus on markup as pertains to the editorial transcription of this documentary text and to the linguistic analysis of the text’s language.
Virginia Tech Residence Hall Federation recognized with multiple awards at annual conference
Gehrt, Katie
2009-01-01
On Feb. 8, 2009, the Virginia Tech Residence Hall Federation took home five awards at the 2009 Virginia Association of College and University Residence Halls (VACURH) conference, held this year at The University of Virginia-Wise, located in Wise, Va.
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.
Lessons from Hurricane Sandy: a community response in Brooklyn, New York.
Schmeltz, Michael T; González, Sonia K; Fuentes, Liza; Kwan, Amy; Ortega-Williams, Anna; Cowan, Lisa Pilar
2013-10-01
The frequency and intensity of extreme weather events have increased in recent decades; one example is Hurricane Sandy. If the frequency and severity continue or increase, adaptation and mitigation efforts are needed to protect vulnerable populations and improve daily life under changed weather conditions. This field report examines the devastation due to Hurricane Sandy experienced in Red Hook, Brooklyn, New York, a neighborhood consisting of geographically isolated low-lying commercial and residential units, with a concentration of low-income housing, and disproportionate rates of poverty and poor health outcomes largely experienced by Black and Latino residents. Multiple sources of data were reviewed, including street canvasses, governmental reports, community flyers, and meeting transcripts, as well as firsthand observations by a local nonprofit Red Hook Initiative (RHI) and community members, and social media accounts of the effects of Sandy and the response to daily needs. These data are considered within existing theory, evidence, and practice on protecting public health during extreme weather events. Firsthand observations show that a community-based organization in Red Hook, RHI, was at the center of the response to disaster relief, despite the lack of staff training in response to events such as Hurricane Sandy. Review of these data underscores that adaptation and response to climate change and likely resultant extreme weather is a dynamic process requiring an official coordinated governmental response along with on-the-ground volunteer community responders.
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.
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)
Sexiled: Privacy Acquisition Strategies of College Roommates
Erlandson, Karen
2014-01-01
This study sought to understand how roommates make privacy bids in college residence halls. The results indicate that privacy for sexual activity is a problem for students living in college residence halls, as almost all participants (82%) reported having dealt with this issue. Two sets of responses were collected and analyzed: privacy acquisition…
Sexiled: Privacy Acquisition Strategies of College Roommates
Erlandson, Karen
2014-01-01
This study sought to understand how roommates make privacy bids in college residence halls. The results indicate that privacy for sexual activity is a problem for students living in college residence halls, as almost all participants (82%) reported having dealt with this issue. Two sets of responses were collected and analyzed: privacy acquisition…
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.
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.
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.
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.
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
The Challenges and Opportunities of Residence Hall Facilities.
Thaler-Carter, Ruth E.
2001-01-01
Explores the challenges facing college and university residence hall facility managers and how different schools address these issues in diverse ways. Ongoing concerns involving funding needs and maintenance are examined followed by discussions on the new challenges in managing student life, health, and safety. Concluding comments reveal where…
Sjostrom, Barbara R.; Sica, Michael
The Bilingual Demonstration College Preparatory Program, in its second year of funding, provided English as a second language (ESL) and native language instruction, in addition to bilingual instruction in mathematics, social studies, and science, to 120 Spanish-speaking students in grades 9-12 at George W. Wingate High School (Brooklyn, New York).…
Plasma Relaxation in Hall Magnetohydrodynamics
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.
Alcohol Trajectories over Three Years in a Swedish Residence Hall Student Population
Henriettae Ståhlbrandt
2010-03-01
Full Text Available Although it is known that college students have a high alcohol consumption, less is known about the long-term drinking trajectories amongst college students and, in particular, students living in residence halls, known to be high-risk drinkers. Over four consecutive years, the drinking habits of 556 Swedish residence hall students were analyzed. The main instruments for measuring outcome were AUDIT (Alcohol Use Identification Disorders Test, SIP (Short Index of Problems and eBAC (estimated Blood Alcohol Concentration. The drinking trajectories among Swedish residence hall students showed stable and decreasing drinking patterns, with age and gender being predictors of group membership.
Building America Case Study: Retrofitting Garden-Style Apartments, Brooklyn, New York
2016-12-01
This research effort sought to achieve a solution package that yields energy savings greater than 30 percent over the pre-existing conditions in a minimally intrusive multifamily retrofit project. The Consortium for Advanced Residential Buildings (CARB) partnered with L+M Development Partners, Inc. on a Mitchell-Lama Housing Program project, Marcus Garvey Village, in Brooklyn, NY (Climate Zone 4A). The Mitchell-Lama Housing Program is a form of housing subsidy in the state of New York that provides affordable rental and cooperative housing to moderate- and middle-income families. Marcus Garvey Village was founded in 1975 and contains 625 residential units (ranging from studios to 5-bedroom units) in thirty-two 4-story garden-style apartment structures built with concrete and faced in light brown brick. The single largest challenge for implementation of energy conservation measures at Marcus Garvey was working within occupied spaces. Measures are being implemented in phases to minimize disruption. As of August 2015, the retrofit work is over 50 percent complete. The wall insulation, sealing of the through wall AC vent, and installation of new oil-filled electric baseboards with advanced controls are conducted at one time, limiting disruption to the living room space. In a similar fashion, the kitchen work is done, then the bathroom. The final selection of energy conservation measures is projected to save 26.5 percent in source energy with a cost just under $3.7 million and utility bill savings of nearly $480,000 (of an average $1.8 million annual utility cost for the development).
Building America Case Study: Retrofitting Garden-Style Apartments, Brooklyn, New York
H. Nolen, S. Maxwell, R. Neri, J. Grab
2016-12-01
This research effort sought to achieve a solution package that yields energy savings greater than 30 percent over the pre-existing conditions in a minimally intrusive multifamily retrofit project. The Consortium for Advanced Residential Buildings (CARB) partnered with L+M Development Partners, Inc. on a Mitchell-Lama Housing Program project, Marcus Garvey Village, in Brooklyn, NY (Climate Zone 4A). The Mitchell-Lama Housing Program is a form of housing subsidy in the state of New York that provides affordable rental and cooperative housing to moderate- and middle-income families. Marcus Garvey Village was founded in 1975 and contains 625 residential units (ranging from studios to 5-bedroom units) in thirty-two 4-story garden-style apartment structures built with concrete and faced in light brown brick. The single largest challenge for implementation of energy conservation measures at Marcus Garvey was working within occupied spaces. Measures are being implemented in phases to minimize disruption. As of August 2015, the retrofit work is over 50 percent complete. The wall insulation, sealing of the through wall AC vent, and installation of new oil-filled electric baseboards with advanced controls are conducted at one time, limiting disruption to the living room space. In a similar fashion, the kitchen work is done, then the bathroom. The final selection of energy conservation measures is projected to save 26.5 percent in source energy with a cost just under $3.7 million and utility bill savings of nearly $480,000 (of an average $1.8 million annual utility cost for the development).
Cylindrical geometry hall thruster
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.
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.
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.
"Hall viscosity" and intrinsic metric of incompressible fractional Hall fluids
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 ...
Wheel of concert hall acoustics
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
Thermal Hall Effect of Magnons
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.
The Role of Municipal Water Ortho-Phosphate on Eutrophication at Prospect Park, Brooklyn, New York
Liu, Y.; Cheng, Z.; Jordan, J.; Doan, A.
2008-05-01
Ortho-phosphate has been added to municipal supply as one of the measures for drinking water lead control since 1990's. In New York City, P concentration of tap water has been maintained at about 2 ppm for the past decade. As a result, on average 4 metric tons of P enter the drinking water supply and eventually it is deposited, accumulated and recycled in urban water systems. The impact of this excessive nutrient on urban environment and ecosystems, especially over the long term, has not been adequately addressed. Prospect Lake in Brooklyn is composed of a series of ponds whose water are fed mainly by municipal water supply. More and more severe eutrophication symptoms have become apparent in the past decade. Prospect Park is one of the largest parks in New York City that is visited by millions of people each year. Eutrophication prevailing almost all year in its water system poses management challenges. Finding ways to cure this "chronic disease" requires pinpointing the main source of the nutrients for algal boom. There is an ongoing controversy as to the importance of orthophosphate from the municipal water supply. Preliminary measurements indicate that most P gradually deposit into the series of ponds as it runs through the water system. Although fertilizer has rarely been used at Prospect Park, runoff from nearby lands could have also brought in nutrients that need to be quantified. The contributions from groundwater and animals also remain poorly understood. In addition, there is lack of fundamental understanding of the effects of hydrodynamics and recycling of P among the sediment-water-ecological systems. A phosphorus budget model is being established to study the distribution, recycling, and transport of inorganic and organic P. Ongoing experiments isolate the contributions from dissolved P and sediment P for algal growth. Sediment and water samples are taken from the lake, and then placed in a microcosm system to study the effect of aqueous and sediment
Human fetal exposure to triclosan and triclocarban in an urban population from Brooklyn, New York.
Pycke, Benny F G; Geer, Laura A; Dalloul, Mudar; Abulafia, Ovadia; Jenck, Alizee M; Halden, Rolf U
2014-01-01
Triclosan (TCS) and triclocarban (TCC) are antimicrobial agents formulated in a wide variety of consumer products (including soaps, toothpaste, medical devices, plastics, and fabrics) that are regulated by the U.S. Food and Drug Administration (FDA) and U.S. Environmental Protection Agency. In late 2014, the FDA will consider regulating the use of both chemicals, which are under scrutiny regarding lack of effectiveness, potential for endocrine disruption, and potential contribution to bacterial resistance to antibiotics. Here, we report on body burdens of TCS and TCC resulting from real-world exposures during pregnancy. Using liquid chromatography tandem mass spectrometry, we determined the concentrations of TCS, TCC, and its human metabolites (2'-hydroxy-TCC and 3'-hydroxy-TCC) as well as the manufacturing byproduct (3'-chloro-TCC) as total concentrations (Σ-) after conjugate hydrolysis in maternal urine and cord blood plasma from a cohort of 181 expecting mother/infant pairs in an urban multiethnic population from Brooklyn, NY recruited in 2007-09. TCS was detected in 100% of urine and 51% of cord blood samples after conjugate hydrolysis. The interquartile range (IQR) of detected TCS concentrations in urine was highly similar to the IQR reported previously for the age-matched population of the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2004, but typically higher than the IQR reported previously for the general population (detection frequency = 74.6%). Urinary levels of TCC are reported here for the first time from real-world exposures during pregnancy, showing a median concentration of 0.21 μg/L. Urinary concentrations of TCC correlated well with its phase-I metabolite ∑-2'-hydroxy-TCC (r = 0.49) and the manufacturing byproduct ∑-3'-chloro-TCC C (r = 0.79), and ∑-2'-hydroxy-TCC correlated strongly with ∑-3'-hydroxy-TCC (r = 0.99). This human biomonitoring study presents the first body burden data for TCC from exposures
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.
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
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 ...
Risk factors for meningococcal disease in university halls of residence.
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
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...
Cosmopolitanism - Conversation with Stuart Hall
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
Lynch, Joanne
This report presents an evaluation of the Excellence and Success through Career Understanding and Enriched Language Activities (Project ESCUELA), an Elementary and Secondary Education Act Title VII-funded project in its second year of operation at five schools in Brooklyn, New York. The project served 415 Spanish-speaking and 178 Yiddish-speaking…
Hall Effect Gyrators and Circulators
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.
Topological Hall and spin Hall effects in disordered skyrmionic textures
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.
Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance
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.
City and Town Halls; townHalls13
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...
Ward Identities for Hall Transport
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.
Planar Hall effect bridge magnetic field sensors
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....
Shared Magnetics Hall Thruster Project
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...
Shared Magnetics Hall Thruster Project
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...
"Hall mees" Linnateatris / Triin Sinissaar
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
"Hall mees" Linnateatris / Triin Sinissaar
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
General footage ISOLDE experimental hall HD
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.
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.
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).
卢洁峰
2012-01-01
摘要：1923年7月投入使用的金陵女子大学新校区,拥有一个中国宫殿式的建筑群。此建筑群构思独特,器宇轩昂。1919年～1923年春,吕彦直参与了金陵女子大学建筑群的建筑设计和建筑监理等工作。以往,建筑史学界对金陵女子大学建筑群尚缺乏深入的研究。本文独辟蹊径,通过研究金陵女子大学建筑群与南京中山陵和广州中山纪念堂这两座中山纪念建筑之间的联系,追溯其对中国第一代建筑师的杰出代表吕彦直建筑思想形成的启始作用。%The new campus of Ginling College, put into use since July 1923, owns a Chinese palace-style buildings group, which brought the unique and magnificent experience. Lu Yen-chih took part in designing the buildings of Ginling College and construction management during 1919 to 1923. Few in-depth studies on the buildings groups of Ginling College have been made. This article starts a new way of study, through its links with Sun Yat-sen Mausoleum and Guangzhou Sun Yat-sen Memorial Hall, to explore for initial impact on the shaping program of Lu Yen-chih＇ architectural thoughts.
Displacement ventilation in lecture halls
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...
Angotti, T
2015-04-01
Proponents of urban agriculture have identified its potential to improve health and the environment but in New York City and other densely developed and populated urban areas, it faces huge challenges because of the shortage of space, cost of land, and the lack of contemporary local food production. However, large portions of the city and metropolitan region do have open land and a history of agricultural production in the not-too-distant past. Local food movements and concerns about food security have sparked a growing interest in urban farming. Policies in other sectors to address diet-related illnesses, environmental quality and climate change may also provide opportunities to expand urban farming. Nevertheless, for any major advances in urban agriculture, significant changes in local and regional land use policies are needed. These do not appear to be forthcoming any time soon unless food movements amplify their voices in local and national food policy. Based on his experiences as founder of a small farm in Brooklyn, New York and his engagement with local food movements, the author analyzes obstacles and opportunities for expanding urban agriculture in New York. Copyright © 2014 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Bound values for Hall conductivity of heterogeneous medium under quantum Hall effect conditions
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.
Berry curvature and various thermal Hall effects
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.
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…
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…
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
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.
Planar Hall effect bridge magnetic field sensors
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.
Optical Hall effect-model description: tutorial.
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.
Misut, P.E.; Voss, C.I.
2007-01-01
Freshwater storage in deep aquifers of Brooklyn and Queens, New York, USA, is under consideration as an emergency water supply for New York City. The purpose of a New York City storage and recovery system is to provide an emergency water supply during times of drought or other contingencies and would entail longer-term storage phases than a typical annual cycle. There is concern amongst neighboring coastal communities that such a system would adversely impact their local water supplies via increased saltwater intrusion. This analysis uses three-dimensional modeling of variable-density ground-water flow and salt transport to study conditions under which hypothetical aquifer storage and recovery (ASR) may not adversely impact the coastal water supplies. A range of storage, pause, and recovery phase lengths and ASR cycle repetitions were used to test scenarios that emphasize control of potential saltwater intrusion. The USGS SUTRA code was used to simulate movement of the freshwater-saltwater transition zones in a detailed model of the upper glacial, Jameco, Magothy, and Lloyd aquifers of western Long Island, New York. Simulated transition zones in the upper glacial, Jameco, and Magothy aquifers reach a steady state for 1999 stress and recharge conditions within 1 ka; however, saltwater encroachment is ongoing in the Lloyd (deepest) aquifer, for which the effects of the rise in sea level since deglaciation on transition zone equilibration are retarded by many ka due to the thick, overlying Raritan confining unit. Pumping in the 20th century has also caused widening and landward movement of the Lloyd aquifer transition zone. Simulation of scenarios of freshwater storage by injection followed by phases of pause and recovery by extraction indicates that the effect of net storage when less water is recovered than injected is to set up a hydraulic saltwater intrusion barrier in the Lloyd aquifer which may have beneficial effects to coastal water users. ?? 2007 Elsevier B
Electron dynamics in Hall thruster
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.
Symmetric functions and Hall polynomials
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...
El Puente de Brooklyn y el cine. Análisis fílmico-estético de la estructura
Plasencia Lozano, Pedro
2011-01-01
Actas del Segundo Congreso Internacional de Historia y Cine organizado por el Instituto de Cultura y Tecnología Miguel de Unamuno y celebrado del 9 al 11 de septiembre de 2010 en la Universidad Carlos III de Madrid El puente de Brooklyn es posiblemente la estructura más filmada en toda la historia del cine. En el artículo se analiza si esta circunstancia se debe a sus cualidades ingenieriles, a las innovaciones técnicas que presentó en su momento y a sus virtudes paisajísticas, estudiando ...
Spin Hall effect by surface roughness
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.
Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator
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.
Low-Voltage Hall Thruster Mode Transitions
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
Listening to the acoustics in concert halls
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.
Hall probes: physics and application to magnetometry
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.
DEVELOPMENT OF IMPROVED HALL EFFECT SENSORS.
HALL EFFECT , MAGNETOMETERS, GAIN, SENSITIVITY, MAGNETIC FIELDS, DETECTION, ELECTROMAGNETIC PROBES, WEIGHT, VOLUME, BATTERY COMPONENTS, INDIUM ALLOYS, ANTIMONY ALLOYS, FERRITES, MANPORTABLE EQUIPMENT.
AN A. C. HALL EFFECT GAUSSMETER,
MEASURING INSTRUMENTS, MEASURING INSTRUMENTS, HALL EFFECT , MAGNETOMETERS, MEASUREMENT, GENERATORS, CIRCUITS, ALTERNATING CURRENT, GERMANIUM, SEMICONDUCTOR DIODES, GALVANOMETERS, VOLTAGE, DIRECT CURRENT, MAGNETIC FIELDS.
Lectures on the Quantum Hall Effect
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.
Anomalous Hall effect in polycrystalline Ni films
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.
(MOthers from the Motherland in Edna O’Brien’s The Light of Evening and Colm Tóibín’s Brooklyn
Marisol Morales Ladrón
2014-01-01
Full Text Available From the last decade, interest in the rewriting of received notions of the Irish diaspora and of the great famine in the literature produced in Ireland has notably increased, in an attempt to revise both Irish history and identity. Within this impulse in contemporary Irish literature, two enduring authors stand out, Edna O’Brien and Colm Tóibín, whose novels, The Light of Evening (2006 and Brooklyn (2009, focus on the individual experiences of post-famine female emigrants to the United States in their unsuccessful attempts to find better living conditions either in the so-called “Promised land” or in their homeland. Taking O’Brien’s The Light of Evening as a predecessor of Tóibín’s Brooklyn, I will argue along this paper that the stories of female emigration unfolded in the two narratives complement each other in ways that, by and large, have passed unnoticed by critics and reviewers. Considering the bond to the land as a metaphor of the bond to the mother, through the present discussion I will also explore O Brien’s and Toíbín’s current discourses on emigration in light of their portrayal of the conflictive mother figures that mirror their own motherland.
Automated Micro Hall Effect measurements
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....
Temperature Gradient in Hall Thrusters
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.
Physics with a focal plane proton polarimeter for hall A at CEBAF
Gilman, R. [Continuous Electron Beam Accelerator Facility, Newport News, Virginia 23606 (United States)]|[Rutgers University, Piscataway, New Jersey 08855 (United States); Baker, F.T. [University of Georgia, Athens, Georgia 30602 (United States); Bimbot, L. [Rutgers University, Piscataway, New Jersey 08855 (United States); Brash, E. [College of William and Mary, Williamsburg, Virginia 23187 (United States); Glashausser, C. [Rutgers University, Piscataway, New Jersey 08855 (United States); Jones, M. [College of William and Mary, Williamsburg, Virginia 23187 (United States); Kumbartzki, G. [Rutgers University, Piscataway, New Jersey 08855 (United States); Nanda, S. [Continuous Electron Beam Accelerator Facility, Newport News, Virginia 23606 (United States); Perdrisat, C. [College of William and Mary, Williamsburg, Virginia 23187 (United States); Punjabi, V. [Norfolk State University, Norfolk, Virginia 23504 (United States); Ransome, R. [Rutgers University, Piscataway, New Jersey 08855 (United States); Rutt, P. [Rutgers University, Piscataway, New Jersey 08855 (United States)]|[University of Georgia, Athens, Georgia 30602 (United States)
1995-09-01
A focal plane polarimeter intended for the CEBAF Hall A high resolution hadron spectrometer is under construction at Rutgers University and the College of William and Mary. Experiments with focal plane polarimeters are only now beginning at electron accelerators; they play a prominent role in the list of approved experiments for Hall A. Construction of the polarimeter is in progress, it is expected to be brought to CEBAF in spring 1995. Several coincidence (e,e{prime}{bar p}) and singles ({gamma},{bar p}) measurements by the Hall A Collaboration are expected to start in 1996. In this paper we describe the polarimeter and the physics program planned for it. {copyright} {ital 1995 American Institute of Physics.}
A Holographic Quantum Hall Ferromagnet
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...
Infrared Hall Conductivity in Graphene
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.
Library rooms or Library halls
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
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…
Hall effect accompanying a static skin effect
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.
Acoustical parameters in concert hall acoustics
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.
The Scientific Humanism of G. Stanley Hall
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)
Star Formation and the Hall Effect
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...
Stuart Hall: An Organic Intellectual
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.
Matthias, Ruth
This program was devised in an attempt to train more effective resident advisors for the 1972-73 school year at a dormitory at California State University. The special characteristics of the dormitory--racially mixed and discordant--seemed to indicate a need for a special kind of resident advisor training program, one that attempted to better…
Optical Hall effect in strained graphene
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.
Cynthia J. Bashore
2014-08-01
Full Text Available Adverse birth outcomes including preterm birth (PTB: <37 weeks gestation and low birth weight (LBW: <2500 g can result in severe infant morbidity and mortality. In the United States, there are racial and ethnic differences in the prevalence of PTB and LBW. We investigated the association between PTB and LBW with prenatal mercury (Hg exposure and season of conception in an urban immigrant community in Brooklyn, New York. We recruited 191 pregnant women aged 18–45 in a Brooklyn Prenatal Clinic and followed them until delivery. Urine specimens were collected from the participants during the 6th to 9th month of pregnancy. Cord blood specimens and neonate anthropometric data were collected at birth. We used multivariate logistic regression models to investigate the odds of LBW or PTB with either maternal urinary mercury or neonate cord blood mercury. We used linear regression models to investigate the association between continuous anthropometric outcomes and maternal urinary mercury or neonate cord blood mercury. We also examined the association between LBW and PTB and the season that pregnancy began. Results showed higher rates of PTB and LBW in this cohort of women compared to other studies. Pregnancies beginning in winter (December, January, February were at increased odds of LBW births compared with births from pregnancies that began in all other months (OR7.52 [95% CI 1.65, 34.29]. We observed no association between maternal exposure to Hg, and either LBW or PTB. The apparent lack of association is consistent with other studies. Further examination of seasonal association with LBW is warranted.
The quantum Hall effects: Philosophical approach
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.
Quantum Hall Effect in Higher Dimensions
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 $S^4$.
Joule heating in spin Hall geometry
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.
Piezo Voltage Controlled Planar Hall Effect Devices
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.
Piezo Voltage Controlled Planar Hall Effect Devices.
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.
The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field
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.
Light Metal Propellant Hall Thruster Project
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...
Success of Hall technique crowns questioned.
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.
Dual Mode Low Power Hall Thruster Project
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...
Iodine Hall Thruster for Space Exploration Project
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...
The phonon Hall effect: theory and application
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.
Students halls – humane lifestyle for students
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.
Athletics hall, Odenwald school, Heppenheim, Germany
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)
Quantum Hall effect in momentum space
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.
Multiscale Modeling of Hall Thrusters Project
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...
Observation of the magnon Hall effect.
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.
Hall effect degradation of rail gun performance
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.
Iodine Hall Thruster for Space Exploration Project
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,...
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...
Cohomological Hall algebras and character varieties
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.
Hall effect on the triangular lattice
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...
Are tent halls subject to property tax?
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.
Piezo Voltage Controlled Planar Hall Effect Devices
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...
Hall effect in organic layered conductors
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.
An introduction to motivic Hall algebras
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.
Turbulence Measurements in a Tropical Zoo Hall
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.
75 FR 22770 - Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment
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,...
Charge carrier coherence and Hall effect in organic semiconductors.
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.
Edge reconstructions in fractional quantum Hall systems.
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).
The Hall effect in star formation
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...
Mesoscopic effects in the quantum Hall regime
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.
Quantized photonic spin Hall effect in graphene
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.
Graphene-based Hall Sensors for direct magnetic imaging by using Scanning Hall Probe Microscope
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).
EL CROWN HALL. CONTEXTO Y PROYECTO
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
Acoustics in rock and pop music halls
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...
Inverse spin Hall effect by spin injection
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.
Integer quantum Hall effect in graphene
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.
Messite, J.; Fannick, N.L.
1978-07-01
In response to a request from a representative of the nursing staff, an investigation was made of possible methadone exposures at the Cumberland Outpatient Department of Beth Israel Hospital, Brooklyn, New York, a methadone-dispensing clinic. The distribution room measured 12 feet in all dimensions and was enclosed on three sides. Methadone had previously been received in prepackaged doses, but more recently the nurses had to count the contents of each 100-count bottle of methadone hydrochloride and separate tablets or diskets into individual doses. Nurses involved in dispensing the medication reported intermittent sleepiness, itching of the face, nose, and eyes, and dryness of skin on the hands and face. Urine studies indicated no detectable methadone or methadone metabolites at a limit of 1 microgram per milliliter. There is no evidence of methadone absorption; however, they recommend that skin contact with the tablets and diskets be kept to a minimum by use of instruments for moving the pills on the counting tray, frequent clean up of dust, and periodic hand washing.
Interpersonal Proximity and Impression Formation: A Partial Examination of Hall's Proxemic Model.
Tesch, Frederick E
1979-02-01
Interpersonal proximity was examined as a cue in impression formation by varying factorially four interpersonal distances (2', 3 1/4', 5 1/2', 9 1/2'), sex of S (48 male and 48 female American college students), and sex of C (three male and three female students). Interpersonal proximity in the interview situation did not directly affect Ss' impressions of the Cs as measured by the Gough and Heilbrun Adjective Check List and Schutz's FIRO-B test. Although the four distances operationalized two of the interpersonal distance zones in Hall's normative model of human spatial behavior, Ss did not report the expected differences in the experiences of these two zones. The implications of the present findings for the limited role of interpersonal proximity as a cue in impression formation and for Hall's model are discussed.
Destruction of the Fractional Quantum Hall Effect by Disorder
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.
Digital technology impacts on the Arnhem transfer hall structural design
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
New type of magnetization equipment using a commercial Hall sensor
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.
Towards a Better Understanding of the Anomalous Hall Effect
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.
Accurate micro Hall effect measurements on scribe line pads
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...
Parametric Investigations of Non-Conventional Hall Thruster
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.
Digital technology impacts on the Arnhem transfer hall structural design
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
Improved Hall-Effect Sensors For Magnetic Memories
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.
Inertial-Hall effect: the influence of rotation on the Hall conductivity
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.
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.
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.
The magneto-Hall difference and the planar extraordinary Hall balance
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.
The magneto-Hall difference and the planar extraordinary Hall balance
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.
Inertial-Hall effect: the influence of rotation on the Hall conductivity
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.
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
Hall instability of solar flux tubes
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...
Room acoustic properties of concert halls
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...
Acoustics in rock and pop music halls
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...
Anomalous Hall Effect for chiral fermions
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.
Supersymmetry in the Fractional Quantum Hall Regime
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 $\
Hall Effect Thruster Ground Testing Challenges
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
Development and applications of mesoscopic hall microprobes
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
Fractional Quantization of the Hall Effect
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.
Moderate positive spin Hall angle in uranium
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.
Dust exposure in indoor climbing halls.
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
The Magneto-Hall Difference and the Planar Extraordinary Hall Balance
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...
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.
Comparison of secondary islands in collisional reconnection to Hall reconnection.
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.
Parallel Hall effect from 3D single-component metamaterials
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
Diagnostics Systems for Permanent Hall Thrusters Development
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
Hahn, Intaek; Wiener, Russell W; Richmond-Bryant, Jennifer; Brixey, Laurie A; Henkle, Stacy W
2009-12-01
The Brooklyn traffic real-time ambient pollutant penetration and environmental dispersion (B-TRAPPED) study was a multidisciplinary field research project that investigated the transport, dispersion, and infiltration processes of traffic emission particulate matter (PM) pollutants in a near-highway urban residential area. The urban PM transport, dispersion, and infiltration processes were described mathematically in a theoretical model that was constructed to develop the experimental objectives of the B-TRAPPED study. In the study, simultaneous and continuous time-series PM concentration and meteorological data collected at multiple outdoor and indoor monitoring locations were used to characterize both temporal and spatial patterns of the PM concentration movements within microscale distances (dispersion of PM; (3) studying the influence of meteorological variables on the transport, dispersion, and infiltration processes; (4) characterizing the relationships between the building parameters and the infiltration mechanisms; (5) establishing a cause-and-effect relationship between outdoor-released PM and indoor PM concentrations and identifying the dominant mechanisms involved in the infiltration process; (6) evaluating the effectiveness of a shelter-in-place area for protection against outdoor-released PM pollutants; and (7) understanding the predominant airflow and pollutant dispersion patterns within the neighborhood using wind tunnel and CFD simulations. The 10 papers in this first set of papers presenting the results from the B-TRAPPED study address these objectives. This paper describes the theoretical background and models representing the interrelated processes of transport, dispersion, and infiltration. The theoretical solution for the relationship between the time-dependent indoor PM concentration and the initial PM concentration at the outdoor source was obtained. The theoretical models and solutions helped us to identify important parameters in the
谢雪清
2014-01-01
The construction of Moral Lecture Hall is an important plan of Central Civilization Office, as well as an effective carrier to develop and practice the socialist core values.Centering on moral theme, moral character, procedures and actual effect, Moral Lecture Hall of Hezhou University sets a party of typical moral examples who are around us.This helps to improve university students'ideological and moral cultivation and guide the students to effectively practise the socialist core values.Moral Lecture Hall will become a thematic educational platform with rich contents and flexible forms.%“道德讲堂”建设是中央文明办的一个重要部署，同时也是高校培育和践行社会主义核心价值观的一个有效载体。贺州学院道德讲堂以道德主题为核心，道德人物为灵魂，流程环节为关键，活动实效为目的，树立了一批“接地气”的身边道德人物典型，有利于提高大学生思想道德修养和文明程度，引导大学生更加积极有效地践行社会主义核心价值观，成为一个内容丰富、形式灵活的主题教育平台。
The Hall Algebra of Cyclic Serial Algebra
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.
Three halls for music performance in Chile
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.
Acoustics in rock and pop music halls
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....
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
Hall Scrambling on Black Hole Horizon
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.
Music hall Markneukirchen; Musikhalle in Markneukirchen
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)
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.
Geometric Photonic Spin Hall Effect with Metapolarization
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...
Thermal Characterization of a Hall Effect Thruster
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
Electron-wall Interaction in Hall Thrusters
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.
Homotopy arguments for quantized Hall conductivity
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.
Industrial steel hall with bridge grane
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...
The Hall D Physics Program at JLab
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.
Views of the ATLAS experimental hall
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.
Acoustics in rock and pop music halls
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....
SERVIR Town Hall - Connecting Space to Village
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.
2012-03-16
... National Park Service Notice of Intent To Repatriate Cultural Items: The Colorado College, Colorado Springs..., Colorado College, Armstrong Hall, Room 201, 14 E. Cache La Poudre, Colorado Springs, CO 80903, telephone... as the Taylor Museum and the Colorado Springs Fine Arts Center) and the Denver Museum of...
2012-04-19
... National Park Service Notice of Intent To Repatriate Cultural Items: The Colorado College, Colorado Springs..., Colorado College, Armstrong Hall, Room 201, 14 E. Cache La Poudre, Colorado Springs, CO 80903, telephone... Fine Arts Center (formerly known as the Taylor Museum and the Colorado Springs Fine Arts Center)...
2013-03-29
... National Park Service Notice of Intent To Repatriate Cultural Items: The Colorado College, Colorado Springs... College, Armstrong Hall, Room 201, 14 E. Cache La Poudre, Colorado Springs, CO 80903, telephone (719) 389... Center (formerly known as the Taylor Museum and the Colorado Springs Fine Arts Center) and the...
A Magnetic Balance with Hall Effect Sensors
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.
Hall measurements on InAs nanowires
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.
Quantum anomalous Hall effect in real materials
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.
Generic superweak chaos induced by Hall effect.
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.
Antiferromagnetic skyrmion crystals: Generation, topological Hall, and topological spin Hall effect
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.
Dissipationless spin-Hall current contribution in the extrinsic spin-Hall effect
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.
Department of Homeland Security — The Supplemental Colleges layer attempts to capture additional Post Secondary Education campuses of colleges and universities associated with a single campus listed...
Commemorative Symposium on the Hall Effect and its Applications
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...
Basic Instrumentation for Hall A at Jefferson Jab
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.
Estimates of Quantities in a Hall Effect Geodynamo Theory
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.
Estimates of quantities in a Hall effect geodynamo theory
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.
Charge and Current in the Quantum Hall Matrix Model
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 ...
Hall effect in strongly correlated low dimensional systems
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.
Fabrication of a vector Hall sensor for magnetic microscopy
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.
Quantized Thermal Transport in the Fractional Quantum Hall Effect
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...
Pseudospectral Model for Hybrid PIC Hall-effect Thruster Simulation
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
The Hall module of an exact category with duality
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...
Dynamic Feedback in Ferromagnet-Spin Hall Metal Heterostructures
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.
Composite particle and field theory in atomic quantum Hall effect
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.
High Efficiency Hall Thruster Discharge Power Converter Project
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...
Hall Sensor Output Signal Fault-Detection & Safety Implementation Logic
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.
Probing magnetic microstructures with quasi-ballistic Hall crosses
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.
Hall and Nernst effects in monolayer MoS2
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.
Quantized Anomalous Hall Effect in Magnetic Topological Insulators
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.
MAGNETORESISTANCE AND HALL EFFECT IN SINGLE CRYSTALS OF ALUMINUM
ALUMINUM, *SINGLE CRYSTALS, CRYSTALS, HALL EFFECT , IMPURITIES, LOW PRESSURE, MAGNETIC FIELDS, MAGNETIC PROPERTIES, PARTICLE TRAJECTORIES, ELECTRICAL RESISTANCE, SOLID STATE PHYSICS, SURFACE PROPERTIES.
Laughlin's argument for the quantized thermal Hall effect
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.
Duality in the quantum Hall system
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.
Twisted CFT and bilayer Quantum Hall systems
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.
Hypernuclear spectroscopy program at JLab Hall C
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.
Current correlations in quantum spin Hall insulators.
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.
Anomalous Hall Effect in a Kagome Ferromagnet
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.
Supercurrent in the quantum Hall regime
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.
Novel optical probe for quantum Hall system
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.
Excitons in the Fractional Quantum Hall Effect
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.
Anesthetic considerations in Sheldon-Hall syndrome.
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.
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.
Intrinsic valley Hall effect in graphene
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.
Repurposing the Caltech Robinson Hall Coelostat
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
Plume Comparisons between Segmented Channel Hall Thrusters
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.
Radiation heating in sports halls. Stralingsverwarming in sporthallen
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
A Larger Scale. Tenth Annual Residence Hall Construction Report.
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…
The first vineyard concert hall in North America
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.
Stuart Hall on Racism and the Importance of Diasporic Thinking
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…
Acoustic investigations of concert halls for rock music
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...
Cultural Composition: Stuart Hall on Ethnicity and the Discursive Turn.
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…
Stuart Hall on Racism and the Importance of Diasporic Thinking
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…
Pair spectrometer hodoscope for Hall D at Jefferson Lab
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.
Mary E. Hall: Dawn of the Professional School Librarian
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…
Useful Pedagogical Applications of the Classical Hall Effect
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…
Spatial sensitivity mapping of Hall crosses using patterned magnetic nanostructures
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
Bulk Versus Edge in the Quantum Hall Effect
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.
Efecto Hall del In en Película Evaporada
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.
Fractional quantum Hall states of bosons on cones
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.
Construction and Operation of a Differential Hall Element Magnetometer
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.
Topological insulator in junction with ferromagnets: Quantum Hall effects
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.
Quantum Hall effect in kagome lattices under staggered magnetic field
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)
Unconventional quantum Hall effect in Floquet topological insulators
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.
Axisymmetric Nonlinear Waves And Structures in Hall Plasmas
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.
Experimental evidence for a two-dimensional quantized Hall insulator
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.
Geometric spin Hall effect of light with inhomogeneous polarization
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.
In-plane magnetization-induced quantum anomalous Hall effect.
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.
Unconventional quantum Hall effect in Floquet topological insulators.
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].
Formulation of the Relativistic Quantum Hall Effect and "Parity Anomaly"
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".
[University residence halls: socialization processes and drug consumption].
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.
College life involves excitement, along with new challenges, risks, and responsibilities. You are meeting new people, learning ... stay healthy and safe while you're in college: Eat a balanced diet Get enough sleep Get ...
Geometric Photonic Spin Hall Effect with Metapolarization
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.
Photonic analogue of quantum spin Hall effect
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...
Gauge Physics of Spin Hall Effect
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.
On-Chip Microwave Quantum Hall Circulator
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.
Photonic spin Hall effect in topological insulators
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.
Hydrodynamic Electron Flow and Hall Viscosity
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.
Geometric Defects in Quantum Hall States
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...
Concept of Operating Indoor Skiing Halls with
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....
Magnetic circuit for hall effect plasma accelerator
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.
Hall MHD Equilibrium of Accelerated Compact Toroids
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.
Mesoscopic spin Hall effect in semiconductor nanostructures
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
Concept of Operating Indoor Skiing Halls with
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....
The quantum Hall effect and its contexts
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...
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.
Residencia hall del Obispado, en Gescher, Alemania
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.
... Harmful and Underage College Drinking Drinking affects college students, their families, and college communities at large. Researchers estimate that ... heavy drinking and alcohol-related consequences because of student expectations and social pressures at the start of the academic year. How ...
Chapa, Marisa; Galvan-De Leon, Vanessa; Solis, Judith; Mundy, Marie-Anne
2014-01-01
During the 79th Texas Legislature, the bill "Advancement of College Readiness in Curriculum" was passed (THECB). As a response to this, high schools and colleges have combined forming an early college high school. The result of this union was a program that condensed the time it took to complete both the high school diploma and up to two…
Hall transport of divalent metal ion modified DNA lattices
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.
Effective Field Theory of Fractional Quantized Hall Nematics
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.
Audience noise in concert halls during musical performances
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....
Audience noise in concert halls during musical performances
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...
Anomalous Hall effect in Fe/Gd bilayers
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
Modelling of micro-Hall sensors for magnetization imaging
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.
TCC2, the target hall of the SPS North Area
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).
Composed planar Hall effect sensors with dual-mode operation
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 ...
Hall conductance and topological invariant for open systems.
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.
Hall effect in CNT doped YBCO high temperature superconductor
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.
Quantized Anomalous Hall Effect in Magnetic Topological Insulators
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.
Kelvin-Helmholtz versus Hall magnetoshear instability in astrophysical flows.
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.
From University Heights to Cooperstown: Halls of Fame and American Memory
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,…
Obituary: R(oyal) Glenn Hall, 1921-2004
McCarthy, Dennis Dean
2004-12-01
R. Glenn Hall died on 25 June 2004 following a battle with prostate cancer. His contributions to the determination of the frequency corresponding to an energy level transition in the Cesium atom led to the definition of the length of the second and formed the basis for precise modern timekeeping. Glenn was born on 23 June 1921 in Koloa, Hawaii, and together with a brother and three sisters, grew up in Albion, Michigan. His father was a professor of political science at Albion College. He graduated from Park College in Parkville, Missouri with a degree in mathematics in 1941. He served as a corpsman in the U. S. Navy during World War II, and went on to earn a PhD at the University of Chicago in 1949. Glenn joined the faculty at the University of Chicago as an instructor from 1949 through 1952 and became a research associate there in 1953. While at the U. of Chicago he worked extensively on mass ratios of binary stars, binary star orbits and the determination of stellar parallaxes. In 1953 Glenn came to the U. S. Naval Observatory (USNO) where he became the Assistant Director of the Time Service Division. His early work at the Naval Observatory was related to the determination of Ephemeris Time (ET) from photographic observations of the Moon with respect to background stars. This work provided a time scale more uniform than that based on the Earth's rotation, which was the internationally accepted time scale at the time. As a result, the International Astronomical Union in 1955 redefined the second to be the second as determined from Ephemeris Time. In June 1955, L. Essen and J.V.L. Parry placed in operation a Cesium beam atomic standard at the National Physical Laboratory in Teddington, England. William Markowitz (1907-1998), the director of the Time Service, and Hall together with Essen and Parry then began the work leading to the determination of the frequency of the Cesium atom in terms of the second of the seasonally corrected time scale determined from the
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.
Summer residence hall renovations focus on student comfort, environmental sustainability
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.
Segal-Bargmann-Hall Transform and Geometric Quantization
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].
A High Performance Cathode Heater for Hall Thrusters Project
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...
Wellness: A Developmental Programming Model for Residence Halls.
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)
High Throughput Hall Thruster for Small Spacecraft Project
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...
Magnesium Hall Thruster for Solar System Exploration Project
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...
High Input Voltage Hall Thruster Discharge Converter Project
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...
High Throughput Hall Thruster for Small Spacecraft Project
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...
The Dream Comes True in the Golden Hall
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.
Mini array of quantum Hall devices based on epitaxial graphene
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.
Magnesium Hall Thruster for Solar System Exploration Project
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...
Pragmatic data fusion uncertainty concerns: Tribute to Dave L. Hall
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...
Hall Determination of Atomic Radii of Alkali Metals
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.)
Valleytronics. The valley Hall effect in MoS₂ transistors.
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.
Fractional quantum Hall effect in the absence of Landau levels.
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.
Hall Viscosity I: Linear Response Theory for Viscosity
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).
Global regularity for generalized Hall magneto-hydrodynamics systems
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 $\
Phonon Hall Effect in Four-Terminal Junctions
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...
Chern-Simons Dynamics and the Quantum Hall Effect
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.
Spin and Isospin: Exotic Order in Quantum Hall Ferromagnets
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...
Hall viscosity and electromagnetic response of electrons in graphene
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.
Tunnelling anomalous and planar Hall effects (Conference Presentation)
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).
The quantum Hall's effect:A quantum electrodynamic phenomenon
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.
Magnetometry of micro-magnets with electrostatically defined Hall bars
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.
Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials.
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.
The spin Hall effect in a quantum gas.
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.
Anisotropic intrinsic spin Hall effect in quantum wires.
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.
Planar Hall magnetoresistive aptasensor for thrombin detection.
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.
Acoustics in Halls for Speech and Music
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.
Brand new hall in the main building
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...
The integer quantum hall effect revisited
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.
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.
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.
Observational evidence for Hall drift and Hall waves in the crusts of isolated young neutron stars
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...
Eigenanalysis of Ideal Hall MHD Turbulence
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
Azimuthal Spoke Propagation in Hall Effect Thrusters
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.
Mode Transitions in Hall Effect Thrusters
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.
Surajit Kundu
2015-06-01
Full Text Available Introduction: Formaldehyde has been used since decades as a time tested embalming fluid material either alone or in mixture with methyl alcohol, thymol crystals, glycerin and water. We in Medical College, Raigarh use 37% formaldehyde, 7% methyl alcohol and the remaining water to prepare embalming solution for cadavers. The concentration of formaldehyde is usually expressed in terms of parts per million (1 ppm= 1.248 mg/cu.m.. Vapours emanating out of the cadavers within the dissection hall is a potential source of health hazard for all medical professionals, student, faculty or technicians. The discomfort includes irritation to the mucous membrane of the nose, respiratory tract, eyes and also causes allergic reaction of the skin. Materials and Methods: Keeping track of the unconsciously caused complaints, we made a sincere attempt to chalk out the effects of formaldehyde fumes on 100 first MBBS students of Medical College, Raigarh (C.G as they are virgin in terms of formalin exposure. Results: The obtained results were quite dramatic. Maximum number of students was positive as among the various symptoms described. Discussion: Medical students during their dissection course are exposed to formaldehyde, whose exposure is recently considered to be one of the causes of multiple chemical sensitivity. The present study broadly reflects the toxic effects over the first MBBS Indian medical students Conclusion: The presentation also recommends possible methods for reduction of formalin exposure so that the medical students can enter the dissection hall without any mental tension of toxicity of formalin vapours.
High temperature Hall measurement setup for thin film characterization
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.
Stability of Hall equilibria in neutron star crusts
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...
Suitable reverberation times for halls for rock and pop music.
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.
Reconnection dynamics with secondary tearing instability in compressible Hall plasmas
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})
The local nature of incompressibility of quantum Hall effect
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
Higher (odd dimensional quantum Hall effect and extended dimensional hierarchy
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.
Higher (odd) dimensional quantum Hall effect and extended dimensional hierarchy
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.
Spin Hall effects in mesoscopic Pt films with high resistivity
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.
Concert halls with strong lateral reflections enhance musical dynamics.
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.
NASA HERMeS Hall Thruster Electrical Configuration Characterization
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.
The local nature of incompressibility of quantum Hall effect
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.
Nonlinear Quantum Hall effects in Rarita-Schwinger gas
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...
Spin Hall torques generated by rare-earth thin films
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.
Encouraging College Student Active Engagement in Learning: The Influence of Response Methods
Barr, Michele L.
2014-01-01
The purpose of this study was to examine the use of two student response methods within selected college lecture halls. Kinesiology majors from three universities were asked to respond to questions during two consecutive lectures, one using "clickers" and the other using hand-raising. Participation and comprehension rates were…
Revamped Curriculum at a Vermont College Focuses on Life Skills and Career Goals
Bushong, Steven
2009-01-01
The Vermont college has radically revamped its class structure to better prepare students for life beyond the lecture halls. The collegewide program, "Education in 3 Dimensions," centers on three main parts: life-skills workshops, an interdisciplinary core curriculum, and professional courses. Required courses make up all three…
The Efficacy of the Theory of Reasoned Action to Explain Gambling Behavior in College Students
Thrasher, Robert G.; Andrew, Damon P. S.; Mahony, Daniel F.
2007-01-01
Shaffer and Hall (1997) have estimated college student gambling to be three times as high as their adult counterparts. Despite a considerable amount of research on gambling, researchers have struggled to develop a universal theory that explains gambling behavior. This study explored the potential of Ajzen and Fishbein's (1980) Theory of Reasoned…
77 FR 13626 - Notice of Inventory Completion: Maxey Museum, Whitman College, Walla Walla, WA
2012-03-07
... determined that there is a cultural affiliation between the human remains and associated funerary objects and... additional claimants come forward. DATES: Representatives of any Indian tribe that believes it has a cultural... Memorial Hall, the main administrative building of Whitman College, and subsequently moved to Maxey...
Encouraging College Student Active Engagement in Learning: The Influence of Response Methods
Barr, Michele L.
2014-01-01
The purpose of this study was to examine the use of two student response methods within selected college lecture halls. Kinesiology majors from three universities were asked to respond to questions during two consecutive lectures, one using "clickers" and the other using hand-raising. Participation and comprehension rates were…
A Health Communication Intervention to Reduce High-Risk Drinking among College Students
Glassman, Tavis; Haughton, Noela; Wohlwend, Jennifer; Roberts, Stephen; Jordan, Timothy; Yingling, Faith; Blavos, Alexis
2013-01-01
This investigation examined the effect of a health communication intervention on the alcohol consumption patterns of first-year college students. Researchers employed a quasi-experimental design consisting of students in three residence halls at two Midwestern universities. Between-group comparisons revealed students receiving the intervention…
A Health Communication Intervention to Reduce High-Risk Drinking among College Students
Glassman, Tavis; Haughton, Noela; Wohlwend, Jennifer; Roberts, Stephen; Jordan, Timothy; Yingling, Faith; Blavos, Alexis
2013-01-01
This investigation examined the effect of a health communication intervention on the alcohol consumption patterns of first-year college students. Researchers employed a quasi-experimental design consisting of students in three residence halls at two Midwestern universities. Between-group comparisons revealed students receiving the intervention…
Seville City Hall Chapter Room ceiling decoration
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
Micro-four-point Probe Hall effect Measurement method
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...
Axisymmetric nonlinear waves and structures in Hall plasmas
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.
Maximizing utilization of sport halls during peak hours
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...
Precise quantization of anomalous Hall effect near zero magnetic field
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.
Crossover between spin swapping and Hall effect in disordered systems
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.
Quantum Hall fluids in the presence of topological defects
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...
Novel Hall sensors developed for magnetic field imaging systems
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.
Graphene and the universality of the quantum Hall effect
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...
Collective edge modes in fractional quantum Hall systems
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.
Metal-to-insulator switching in quantum anomalous Hall 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.
Quantitative Analysis of Spin Hall Effect in Nanostructures
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.
Thermal Hall Effect of Spin Excitations in a Kagome Magnet.
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.
The onset of MHD nanofluid convection with Hall current effect
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.
The complete set of Casimirs in Hall-magnetohydrodynamics
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.
Maximizing utilization of sport halls during peak hours
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...
Spontaneous chiral symmetry breaking of Hall magnetohydrodynamic turbulence.
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.
D0 Detector Collision Hall Oxygen Deficiancy Hazard Analysis
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.
The complete set of Casimirs in Hall-magnetohydrodynamics
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.
Composed planar Hall effect sensors with dual-mode operation
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.
Nonlinear transport of graphene in the quantum Hall regime
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.
μHall chip for sensitive detection of bacteria.
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-Hall (μHall) 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.
Overview of NASA Iodine Hall Thruster Propulsion System Development
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.
Hall coefficient of insulating n-type CdSe
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.
Non-Abelian 3d Bosonization and Quantum Hall States
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.
Carl Gustav Jung and Granville Stanley Hall on Religious Experience.
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.
The spin Hall effect of light in moving medium
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.
A Simulation Study of Hall Effect on Double Tearing Modes
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.
Quantum anomalous Hall effect in magnetic insulator heterostructure.
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.
Plasma Diagnostic and Performance of a Permanent Magnet Hall Thruster
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...
Diaphragm Effect of Steel Space Roof Systems in Hall Structures
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
Composed planar Hall effect sensors with dual-mode operation
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.
The transport mechanism of the integer quantum Hall effect
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.
Pairing in Luttinger Liquids and Quantum Hall 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.
Hall Effect–Mediated Magnetic Flux Transport in Protoplanetary Disks
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.
Suitable reverberation time for halls for rock and pop music
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...
Anomalous Hall Effect in a 2D Rashba Ferromagnet.
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.
Quantum inferring acausal structures and the Monty Hall problem
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.
Magnetic noise measurements using cross-correlated Hall sensor arrays
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.
Quantum anomalous Hall effect in topological insulator memory
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.
Background Pressure Effects on Krypton Hall Effect Thruster Internal Acceleration
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
Few-body, hyperspherical treatment of the quantum Hall effect
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.
Phonon Hall effect in four-terminal nano-junctions
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.
Color Ferromagnetism and Quantum Hall states in Quark Matter
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.
Inverse spin Hall effect in a closed loop circuit
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.
Observation of the Spin Hall Effect in Semiconductors
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.
Porting a Hall MHD Code to a Graphic Processing Unit
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.
The Quantum Hall Effect in Supersymmetric Chern-Simons Theories
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.
Stability of Hall equilibria in neutron star crusts
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...
Fractional quantum Hall states of bosons on cones
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.
Magnetar Outbursts from Avalanches of Hall Waves and Crustal Failures
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.
Spin-Hall nano-oscillator: A micromagnetic study
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.
Moiré assisted fractional quantum Hall state spectroscopy
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.
Geometric phase gradient and spin Hall effect of light
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.
Inverse spin Hall effect in Pt/(Ga,Mn)As
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.
Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers
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.
Hall Effect Thruster for High Power Solar Electric Propulsion Technology Demonstration Project
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...
Recent multi-purpose hall designs in Denmark with physically variable acoustics
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...
Measured Early Lateral Energy Fractions in Concert Halls and Opera Houses
BARRON, M.
2000-04-01
In the 30 years since early lateral reflections were first suggested as important for concert halls, spatial impression and source broadening have become almost universally accepted as essential characteristics of halls with good acoustics. Two objective measures of source broadening have been proposed. Measured values of the best defined of these measures, the early lateral energy fraction (LF), are considered here. Results from two independent measurement surveys are discussed. Comparisons of LF values by hall show a significant link between hall mean LF and hall width. There is however considerable overlap between measured LF values in different halls so the relevance of describing halls by their mean early lateral energy fraction values is questionable. The behaviour of LF values within auditoria is discussed for different concert hall plan forms and within opera houses. A measure of source broadening including sound level is proposed and results considered in the context of auditorium design.
Men'shov, Vladimir N.; Tugushev, Victor V.; Chulkov, Evgueni V.
2016-05-01
In this letter we theoretically demonstrate how an interface perturbation and size effect can be used to manipulate the transport properties of semiconductor heterostructures composed of a thin film of a three-dimensional topological insulator (TI) doped with magnetic impurities and sandwiched between topologically normal insulators. In the framework of a continual scheme, we argue that electron states of the TI film are strongly dominated by its thickness and magnetization as well as by an interface potential whose variation can lead to the modification of topological properties of the heterostructure. This opens diverse possibilities to efficiently tune intrinsic Hall conductivity in the system. We calculate a phase diagram of the heterostructure, which demonstrates a series of quantum transitions between distinct regimes of conductivity. We derive the anomalous Hall conductivity and the spin Hall conductivity dependences on the chemical potential. Applicability conditions of the used approach are also discussed.
Mani, Arjun; Benjamin, Colin
2016-04-13
On the surface of 2D topological insulators, 1D quantum spin Hall (QSH) edge modes occur with Dirac-like dispersion. Unlike quantum Hall (QH) edge modes, which occur at high magnetic fields in 2D electron gases, the occurrence of QSH edge modes is due to spin-orbit scattering in the bulk of the material. These QSH edge modes are spin-dependent, and chiral-opposite spins move in opposing directions. Electronic spin has a larger decoherence and relaxation time than charge. In view of this, it is expected that QSH edge modes will be more robust to disorder and inelastic scattering than QH edge modes, which are charge-dependent and spin-unpolarized. However, we notice no such advantage accrues in QSH edge modes when subjected to the same degree of contact disorder and/or inelastic scattering in similar setups as QH edge modes. In fact we observe that QSH edge modes are more susceptible to inelastic scattering and contact disorder than QH edge modes. Furthermore, while a single disordered contact has no effect on QH edge modes, it leads to a finite charge Hall current in the case of QSH edge modes, and thus a vanishing of the pure QSH effect. For more than a single disordered contact while QH states continue to remain immune to disorder, QSH edge modes become more susceptible--the Hall resistance for the QSH effect changes sign with increasing disorder. In the case of many disordered contacts with inelastic scattering included, while quantization of Hall edge modes holds, for QSH edge modes a finite charge Hall current still flows. For QSH edge modes in the inelastic scattering regime we distinguish between two cases: with spin-flip and without spin-flip scattering. Finally, while asymmetry in sample geometry can have a deleterious effect in the QSH case, it has no impact in the QH case.
78 FR 19799 - National Baseball Hall of Fame Commemorative Coin Program Design Competition
2013-04-02
... United States Mint National Baseball Hall of Fame Commemorative Coin Program Design Competition ACTION: Notification of the Opening of the National Baseball Hall of Fame Commemorative Coin Program Design Competition... (heads side) of the 2014 National Baseball Hall of Fame Commemorative Coins. The competition, which...
Comparison of a shielded "One-sided" planar hall-transducer with an MR-head
Fluitman, J.H.J.; Groenland, J.P.J.
1981-01-01
The resistance anisotropy in ferromagnetic conductors gives rise to the related planar magneto-resistive and Hall-effects. The magneto-resistive effect is exploited in several field sensing transducers, while the planar Hall-effect is not. In this paper the output of direct sensing Hall-heads is com
Current Percolation in Medium with Boundaries under Quantum Hall Effect Conditions
M. U. Malakeeva
2012-01-01
Full Text Available The current percolation has been considered in the medium with boundaries under quantum Hall effect conditions. It has been shown that in that case the effective Hall conductivity has a nonzero value due to percolation of the Hall current through the finite number of singular points (in our model these are corners at the phase joints.
HS Jebeli
2012-12-01
Full Text Available Calculation of Hall coefficient in semiclassical approach requires the first and the second derivatives of the energy bands at the Fermi level. We use the Maximally Localized Wannier Function technique to determine the required band derivatives and calculate the ordinary Hall conductivity and ordinary Hall coefficient in Al,Cu, Pd, Li, Au, Ag and Pb cubic metals.
A conjugacy criterion for Hall subgroups in finite groups
Revin, D O
2010-01-01
A finite group $G$ is said to satisfy $C_\\pi$ for a set of primes $\\pi$, if $G$ possesses exactly one class of conjugate $\\pi$-Hall subgroups. In the paper we obtain a criterion for a finite group $G$ to satisfy $C_\\pi$ in terms of a normal series of the group.
Energy efficient heating and ventilation of large halls
Hojer, Ondrej; Kabele, Karel; Kotrbaty, Miroslav; Sommer, Klaus; Petras, Dusan
2011-01-01
This guidebook is focused on modern methods for design, control and operation of energy efficient heating systems in large spaces and industrial halls. The book deals with thermal comfort, light and dark gas radiant heaters, panel radiant heating, floor heating and industrial air heating systems. Various heating systems are illustrated with case studies. Design principles, methods and modeling tools are presented for various systems.
Magnetic vector sensors based on the Hall effect
Roumenin, Ch. S.
Integrated two- and three-dimensional vector versions of the parallel-field Hall microsensor proposed by Roumenin (1987) are presented. The characteristics of Roumenin's microsensor, which is activated by the external magnetic field parallel to the IC plane, are reviewed. The configurations of the magnetic two- and three-dimensional vector microsensors are illustrated and the operation of the microsensors is discussed.
Precision of single-engage micro Hall effect measurements
Henrichsen, Henrik Hartmann; Hansen, Ole; Kjær, Daniel
2014-01-01
]. In this study we calculate the measurement error on RS, NHS and μH resulting from electrode position errors, probe placement, sample size and Hall signal magnitude. We show the relationship between measurement precision and electrode pitch, which is important when down-scaling the micro 4-point probe to fit...
A two fluid description of the Quantum Hall Soliton
Freivogel, Ben [Stanford Univ., Stanford, CA (United States); Susskind, Leonard [Stanford Univ., Stanford, CA (United States); Toumbas, Nicolaos [Stanford Univ., Stanford, CA (United States)
2015-02-03
We show that the Quantum Hall Soliton constructed in [1] is stable under small perturbations. We find that creating quasiparticles actually lowers the energy of the system, and discuss whether this indicates an instability on the time scales relevant to the problem.
Graphene/Si CMOS hybrid hall integrated circuits.
Huang, Le; Xu, Huilong; Zhang, Zhiyong; Chen, Chengying; Jiang, Jianhua; Ma, Xiaomeng; Chen, Bingyan; Li, Zishen; Zhong, Hua; Peng, Lian-Mao
2014-07-07
Graphene/silicon CMOS hybrid integrated circuits (ICs) should provide powerful functions which combines the ultra-high carrier mobility of graphene and the sophisticated functions of silicon CMOS ICs. But it is difficult to integrate these two kinds of heterogeneous devices on a single chip. In this work a low temperature process is developed for integrating graphene devices onto silicon CMOS ICs for the first time, and a high performance graphene/CMOS hybrid Hall IC is demonstrated. Signal amplifying/process ICs are manufactured via commercial 0.18 um silicon CMOS technology, and graphene Hall elements (GHEs) are fabricated on top of the passivation layer of the CMOS chip via a low-temperature micro-fabrication process. The sensitivity of the GHE on CMOS chip is further improved by integrating the GHE with the CMOS amplifier on the Si chip. This work not only paves the way to fabricate graphene/Si CMOS Hall ICs with much higher performance than that of conventional Hall ICs, but also provides a general method for scalable integration of graphene devices with silicon CMOS ICs via a low-temperature process.
Anomalous Hall effect in Cr doped FeSi
Yadam, Sankararao, E-mail: sankararao.yadam@gmail.com; Lakhani, Archana; Singh, Durgesh; Prasad, Rudra; Ganesan, V. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452001 (India)
2016-05-23
Investigations of economically affordable bulk materials for the spin based electronics are in huge demand. In this direction, electrical and Hall transport properties of the polycrystalline Cr doped Kondo insulator FeSi, i.e Fe{sub 0.975}Cr{sub 0.025}Si is reported. Well agreement between temperature dependence of the Hall and linear resistivity are observed. The observed minimum at ~19 K in the resistivity is attributed to the ferromagnetic transition temperature (T{sub C}). Anomalous Hall resistivity is seen in the itinerant ferromagnet, Fe{sub 0.975}Cr{sub 0.025}Si well below the T{sub C}. The obtained Hall resistivity is comparable with that of the spintronic material Fe{sub 0.9}Co{sub 0.1}Si. The present study proves that the electrical transport properties of bulk materials made by low cost elements such as Fe, Cr and Si exhibits large magnetic field effects and are useful for the spintronics applications, unlike spintronics material (Ga, Mn)As that demand higher costs.
Tondiraba jäähall = Tondiraba ice arena
2015-01-01
Tondiraba jäähall Tallinnas Varraku tänav 14, valminud 2014. Arhitektid Ott Kadarik, Mihkel Tüür, Kadri Tamme (Kadarik Tüür Arhitektid OÜ), insener Paavo Pikand. Eesti Kultuurkapitali Arhitektuuri sihtkapitali aastapreemia 2014
Stuart Hall and the Theory and Practice of Articulation
Clarke, John
2015-01-01
In this article, I argue that the idea of articulation links three different dimensions of Stuart Hall's work: it is central to the work of cultural politics, to the work of hegemony and to his practice of embodied pedagogy. I claim that his approach to pedagogy entails the art of listening combined with the practice of theorising in the service…
Hall kirjandus võrgustunud maailmas / Anneli Kuiv
Kuiv, Anneli
2003-01-01
1997. aasta määratluse kohaselt on hall kirjandus "kirjandus, mida toodetakse kõikidel tasanditel valitsus- ja teadusasutuste, äri- ja tootmisringkondade poolt nii trükituna kui ka elektroonselt, kuid mis ei ole kirjastustööstuse kontrolli all"
Towards a quantum Hall effect for atoms using electric fields
Ericsson, M; Ericsson, Marie; Sjoqvist, Erik
2002-01-01
An atomic analogue of Landau quantization based on the Aharonov-Casher (AC) interaction is developed. The effect provides a first step towards an atomic quantum Hall system using electric fields, which may be realized in a Bose-Einstein condensate.
Virtual Environment of Real Sport Hall and Analyzing Rendering Quality
Filip Popovski
2015-02-01
Full Text Available Here is presented virtual environment of a real sport hall created in Quest3D VR Edition. All analyzes of the rendering quality, techniques of interaction and performance of the system in real time are presented. We made critical analysis on all of these techniques on different machines and have excellent results.
Low-frequency noise in planar Hall effect bridge sensors
Persson, Anders; Bejhedb, R.S.; Bejhed, R.S.
2011-01-01
The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a knee...
Hall kirjandus võrgustunud maailmas / Anneli Kuiv
Kuiv, Anneli
2003-01-01
1997. aasta määratluse kohaselt on hall kirjandus "kirjandus, mida toodetakse kõikidel tasanditel valitsus- ja teadusasutuste, äri- ja tootmisringkondade poolt nii trükituna kui ka elektroonselt, kuid mis ei ole kirjastustööstuse kontrolli all"
NASA HERMeS Hall Thruster Electrical Configuration Characterization
Peterson, Peter; Kamhawi, Hani; Huang, Wensheng; Yim, John; Herman, Daniel; Williams, George; Gilland, James; Hofer, Richard
2016-01-01
NASAs 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 presentation will cover the electrical configuration testing of the TDU-1 HERMeS Hall thruster in NASA Glenn Research Centers Vacuum Facility 5. The three electrical configurations examined are the thruster body tied to facility ground, thruster floating, and finally the thruster body electrically tied to cathode common. The TDU-1 HERMeS was configured with two different exit plane boundary conditions, dielectric and conducting, to examine the influence on the electrical configuration characterization.
Single particle detection: Phase control in submicron Hall sensors
Di Michele, Lorenzo; Shelly, Connor; Gallop, John; Kazakova, Olga
2010-11-01
We present a phase-sensitive ac-dc Hall magnetometry method which allows a clear and reliable separation of real and parasitic magnetic signals of a very small magnitude. High-sensitivity semiconductor-based Hall crosses are generally accepted as a preferential solution for non-invasive detection of superparamagnetic nanobeads used in molecular biology, nanomedicine, and nanochemistry. However, detection of such small beads is often hindered by inductive pick-up and other spurious signals. The present work demonstrates an unambiguous experimental route for detection of small magnetic moments and provides a simple theoretical background for it. The reliability of the method has been tested for a variety of InSb Hall sensors in the range 600 nm-5 μm. Complete characterization of empty devices, involving Hall coefficients and noise measurements, has been performed and detection of a single FePt bead with diameter of 140 nm and magnetic moment of μ ≈108 μB has been achieved with a 600 nm-wide sensor.
The Double Ringel-Hall Algebras of Valued Quivers
Yanxin WANG; Jie XIAO
2006-01-01
This paper is devoted to the study of the structure of the double Ringel-Hall algebra D(Λ) for an infinite dimensional hereditary algebra Λ, which is given by a valued quiver Г over a finite field, and also to the study of the relations of D(Λ)-modules with representations of valued quiver Г.
A remark about the Mermin-Squires Music Hall's inteludium
Segre, G
2004-01-01
The Mermin-Squires Music Hall inteludium on the Einstein-Podolsky-Rosen affair is analyzed by showing the fallacity of the One-Borel-Normality Criterion and the necessity of replacing it with the more restrictive Algorithmic-Randomness Criterion
Decomposition of fractional quantum Hall states: New symmetries and approximations
Thomale, R.; Estienne, B.; Regnault, N.; Bernevig, B.A.
2010-01-01
Abstract: We provide a detailed description of a new symmetry structure of the monomial (Slater) expansion coefficients of bosonic (fermionic) fractional quantum Hall states first obtained in Ref. 1, which we now extend to spin-singlet states. We show that the Haldane-Rezayi spin-singlet state can
Light-induced electron localization in a quantum Hall system
Arikawa, T.; Hyodo, K.; Kadoya, Y.; Tanaka, K.
2017-07-01
An insulating bulk state is a prerequisite for the protection of topological edge states. In quantum Hall systems, the thermal excitation of delocalized electrons is the main route to breaking bulk insulation. In equilibrium, the only way to achieve a clear bulk gap is to use a high-quality crystal under high magnetic field at low temperature. However, bulk conduction could also be suppressed in a system driven out of equilibrium such that localized states in the Landau levels are selectively occupied. Here we report a transient suppression of bulk conduction induced by terahertz wave excitation between the Landau levels in a GaAs quantum Hall system. Strikingly, the Hall resistivity almost reaches the quantized value at a temperature where the exact quantization is normally disrupted by thermal fluctuations. The electron localization is realized by the long-range potential fluctuations, which are a unique and inherent feature of quantum Hall systems. Our results demonstrate a new means of effecting dynamical control of topology by manipulating bulk conduction using light.
Graphene/Si CMOS Hybrid Hall Integrated Circuits
Huang, Le; Xu, Huilong; Zhang, Zhiyong; Chen, Chengying; Jiang, Jianhua; Ma, Xiaomeng; Chen, Bingyan; Li, Zishen; Zhong, Hua; Peng, Lian-Mao
2014-07-01
Graphene/silicon CMOS hybrid integrated circuits (ICs) should provide powerful functions which combines the ultra-high carrier mobility of graphene and the sophisticated functions of silicon CMOS ICs. But it is difficult to integrate these two kinds of heterogeneous devices on a single chip. In this work a low temperature process is developed for integrating graphene devices onto silicon CMOS ICs for the first time, and a high performance graphene/CMOS hybrid Hall IC is demonstrated. Signal amplifying/process ICs are manufactured via commercial 0.18 um silicon CMOS technology, and graphene Hall elements (GHEs) are fabricated on top of the passivation layer of the CMOS chip via a low-temperature micro-fabrication process. The sensitivity of the GHE on CMOS chip is further improved by integrating the GHE with the CMOS amplifier on the Si chip. This work not only paves the way to fabricate graphene/Si CMOS Hall ICs with much higher performance than that of conventional Hall ICs, but also provides a general method for scalable integration of graphene devices with silicon CMOS ICs via a low-temperature process.
Planar Hall effect sensor for magnetic micro- and nanobead detection
Ejsing, Louise Wellendorph; Hansen, Mikkel Fougt; Menon, Aric Kumaran
2004-01-01
Magnetic bead sensors based on the planar Hall effect in thin films of exchange-biased permalloy have been fabricated and characterized. Typical sensitivities are 3 muV/Oe mA. The sensor response to an applied magnetic field has been measured without and with coatings of commercially available 2 ...
Dynamics of antiferromagnetic skyrmion driven by the spin Hall effect
Jin, Chendong; Song, Chengkun; Wang, Jianbo; Liu, Qingfang
2016-10-01
Magnetic skyrmion moved by the spin-Hall effect is promising for the application of the generation racetrack memories. However, the Magnus force causes a deflected motion of skyrmion, which limits its application. Here, we create an antiferromagnetic skyrmion by injecting a spin-polarized pulse in the nanostripe and investigate the spin Hall effect-induced motion of antiferromagnetic skyrmion by micromagnetic simulations. In contrast to ferromagnetic skyrmion, we find that the antiferromagnetic skyrmion has three evident advantages: (i) the minimum driving current density of antiferromagnetic skyrmion is about two orders smaller than the ferromagnetic skyrmion; (ii) the velocity of the antiferromagnetic skyrmion is about 57 times larger than the ferromagnetic skyrmion driven by the same value of current density; (iii) antiferromagnetic skyrmion can be driven by the spin Hall effect without the influence of Magnus force. In addition, antiferromagnetic skyrmion can move around the pinning sites due to its property of topological protection. Our results present the understanding of antiferromagnetic skyrmion motion driven by the spin Hall effect and may also contribute to the development of antiferromagnetic skyrmion-based racetrack memories.
Relationship between room shape and acoustics of rectangular concert halls
Klosak, Andrzej K.; Gade, Anders Christian
2008-01-01
Extensive acoustics computer simulations have been made using Odeon computer simulation software. In 24 rectangular rooms representing "shoe-box" type concert halls with volumes of 8 000 m3, 12 000 m3 and 16 000 m3 from 300 to 850 measurements positions have been analysed. Only room averaged...
Can ensemble condition in a hall be improved and measured?
Gade, Anders Christian
1988-01-01
In collaboration with the Danish Broadcasting Corporation an extensive series of experiments has been carried out in The Danish Radio Concert Hall with the practical purpose of trying to improve the ensemble conditions on the platform for the resident symphony orchestra. First, a series of experi......In collaboration with the Danish Broadcasting Corporation an extensive series of experiments has been carried out in The Danish Radio Concert Hall with the practical purpose of trying to improve the ensemble conditions on the platform for the resident symphony orchestra. First, a series...... of the ceiling reflectors; and (c) changing the position of the orchestra on the platform. These variables were then tested in full scale experiments in the hall including subjective evaluation by the orchestra in order to verify their effects under practical conditions. New objective parameters, which showed...... very high correlations with the subjective data, also made it possible to compare the improvements with conditions as recently measured in famous European Halls. Besides providing the needed results, the experiments also shed some light on how musicians change their criteria for judging acoustic...
Stuart Hall and the Theory and Practice of Articulation
Clarke, John
2015-01-01
In this article, I argue that the idea of articulation links three different dimensions of Stuart Hall's work: it is central to the work of cultural politics, to the work of hegemony and to his practice of embodied pedagogy. I claim that his approach to pedagogy entails the art of listening combined with the practice of theorising in the service…
A Two Fluid Description of the Quantum Hall Soliton
Freivogel, Ben; Susskind, Leonard; Toumbas, Nicolaos
2001-01-01
We show that the Quantum Hall Soliton constructed in \\cite{giantbob} is stable under small perturbations. We find that creating quasiparticles actually lowers the energy of the system, and discuss whether this indicates an instability on the time scales relevant to the problem.
Stop Tobacco in Restaurants: Fifth Grade Students STIR City Hall
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…
A topological Dirac insulator in a quantum spin Hall phase
Hsieh, David; Qian, Dong; Wray, Lewis; Xia, Yuqi; San Hor, Yew; Cava, Robert; Hasan, Zahid
2009-03-01
When electrons are subject to a large external magnetic field, the conventional charge quantum Hall effect dictates that an electronic excitation gap is generated in the sample bulk, but metallic conduction is permitted at the boundary. Recent theoretical models suggest that certain bulk insulators with large spin orbit interactions may also naturally support conducting topological boundary states in the quantum limit, which opens up the possibility for studying unusual quantum Hall-like phenomena in zero external magnetic fields. Bulk Bi1-xSbx single crystals are predicted to be prime candidates for one such unusual Hall phase of matter known as the topological insulator. The hallmark of a topological insulator is the existence of metallic surface states that are higher-dimensional analogues of the edge states that characterize a quantum spin Hall insulator. Here, using incident-photon-energy-modulated angle-resolved photoemission spectroscopy, we report the direct observation of massive Dirac particles in the bulk of Bi0.9Sb0.1 and provide a comprehensive mapping of the Dirac insulators gapless surface electron bands. These findings taken together suggest that the observed surface state on the boundary of the bulk insulator is a realization of the topological metal.
Tondiraba jäähall = Tondiraba ice arena
2015-01-01
Tondiraba jäähall Tallinnas Varraku tänav 14, valminud 2014. Arhitektid Ott Kadarik, Mihkel Tüür, Kadri Tamme (Kadarik Tüür Arhitektid OÜ), insener Paavo Pikand. Eesti Kultuurkapitali Arhitektuuri sihtkapitali aastapreemia 2014
Active Learning with Monty Hall in a Game Theory Class
Brokaw, Alan J.; Merz, Thomas E.
2004-01-01
The authors describe a game that students can play on the first day of a game theory class. The game introduces the 4 essential elements of any game and is designed so that its sequel, also played on the first day of class, has students playing the well-known Monty Hall game, which raises the question: Should you switch doors? By implementing a…
Mini array of quantum Hall devices based on epitaxial graphene
Novikov, S.; Lebedeva, N. [Department of Micro and Nanosciences, Aalto University, Micronova, Tietotie 3, Espoo (Finland); Hämäläinen, J.; Iisakka, I.; Immonen, P.; Manninen, A. J.; Satrapinski, A. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, 02044 VTT (Finland)
2016-05-07
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 R{sub H,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×R{sub H,2} = 2 h/e{sup 2} was smaller than the relative standard uncertainty of the measurement (<1 × 10{sup −7}) limited by the used resistance bridge.
Skew Pieri Rules for Hall-Littlewood Functions
Konvalinka, Matjaz
2012-01-01
We produce skew Pieri Rules for Hall--Littlewood functions in the spirit of Assaf and McNamara. The first two were conjectured by the first author. The key ingredients in the proofs are a q-binomial identity for skew partitions and a Hopf algebraic identity that expands products of skew elements in terms of the coproduct and the antipode.
Quantum energy teleportation in a quantum Hall system
Yusa, Go; Izumida, Wataru; Hotta, Masahiro [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
2011-09-15
We propose an experimental method for a quantum protocol termed quantum energy teleportation (QET), which allows energy transportation to a remote location without physical carriers. Using a quantum Hall system as a realistic model, we discuss the physical significance of QET and estimate the order of energy gain using reasonable experimental parameters.
Mechanism of sound absorption by seated audience in halls.
Nishihara, N; Hidaka, T; Beranek, L L
2001-11-01
Four methods are explored for predicting the reverberation times in fully occupied halls for music as related to the sound absorption by their audiences. The methods for providing audience absorptions include two that use reverberation chambers, namely, the ISO 354 method (and other similar standards) (ISO) and Kath and Kuhl's method (K & K) [Acustica 15, 127-131 (1965)], and two that use average data from halls, i.e., Beranek's method (COH) [Concert and Opera Halls: How They Sound (Acoustical Society of America, Melville, NY, 1996)], and the average audience power-per-seat absorption which in practice is multiplied by the number of seats (AA). These methods are applied to the calculation of reverberation times in six existing halls, fully occupied, and the results were compared with actual measurements. The COH method was best for predictions over the entire frequency range. The K & K method showed the highest accuracy at mid-frequencies. Both the ISO and the K & K methods yielded wide differences for the measurements in the 125- and 250-Hz bands. The AA method was as good as the COH method when the measurements for the six halls were averaged, but showed a wide spread in the predictions around the average because it does not consider the degree of upholstering of the seats. It was hypothecated by the authors that the principal reasons for the ISO and K & K discrepancies at low frequencies were (a) differences between the degree of sound diffusion in actual halls and that in reverberation chambers, and (b) lack of information on the mechanisms of absorption of sound by people seated side-by-side in rows, particularly for near-grazing incidence sound fields. First, this article explores the sound diffusivity in a reverberation chamber and in the halls using CAD models. A probability density function of the incident angles of the sound rays that impinge on the audiences is defined and was measured for each case. Using a unique method, the sound absorption
Thermoluminescence measurements of neutron streaming through JET Torus Hall ducts
Obryk, Barbara, E-mail: barbara.obryk@ifj.edu.pl [Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków (Poland); Batistoni, Paola [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); EURATOM–CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Conroy, Sean [EURATOM-VR Association, Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala (Sweden); EURATOM–CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Syme, Brian D.; Popovichev, Sergey [EURATOM–CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Stamatelatos, Ion E.; Vasilopoulou, Theodora [Institute of Nuclear and Radiological Sciences, Energy, Technology and Safety, NCSR “Demokritos”, Athens (Greece); Bilski, Paweł [Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków (Poland)
2014-10-15
Highlights: •Thermoluminescence detectors (TLDs) were used for dose measurements at JET. •Pairs of {sup 6}LiF/{sup 7}LiF TLDs allow to measure thermal neutron component of a radiation field. •For detection of neutrons of higher energy, polyethylene (PE-300) moderators were used. •TLDs were installed at eleven positions in the JET hall and the hall labyrinth. •The experimental results are compared with calculations using the MCNP code. -- Abstract: Thermoluminescence detectors (TLD) were used for dose measurements at JET. Several hundreds of LiF detectors of various types, standard LiF:Mg,Ti and highly sensitive LiF:Mg,Cu,P were produced. LiF detectors consisting of natural lithium are sensitive to slow neutrons, their response to neutrons being enhanced by {sup 6}Li-enriched lithium or suppressed by using lithium consisting entirely of {sup 7}Li. Pairs of {sup 6}LiF/{sup 7}LiF detectors allow distinguishing between neutron/non-neutron components of a radiation field. For detection of neutrons of higher energy, polyethylene (PE-300) moderators were used. TLDs, located in the centre of cylindrical moderators, were installed at eleven positions in the JET hall and the hall labyrinth in July 2012, and exposure took place during the last two weeks of the experimental campaign. Measurements of the gamma dose were obtained for all positions over a range of about five orders of magnitude variation. As the TLDs were also calibrated in a thermal neutron field, the neutron fluence at the experimental position could be derived. The experimental results are compared with calculations using the MCNP code. The results confirm that the TLD technology can be usefully applied to measurements of neutron streaming through JET Torus Hall ducts.
Hall Effect Devices with Three Terminals: Their Magnetic Sensitivity and Offset Cancellation Scheme
Udo Ausserlechner
2016-01-01
Full Text Available This paper discusses properties of Hall effect sensors with only three terminals and compares them to conventional four-terminal devices. It covers both Horizontal and Vertical Hall effect devices. Their Hall-geometry factor is computed analytically. Several modes of operation are proposed and their signal-to-noise ratio is compared. A six-phase offset cancellation scheme is developed. All theoretical results are checked by measurements. The residual offset of Vertical Hall effect devices with three contacts is found to be smaller than the offset of conventional Vertical Hall effect devices with five contacts.
Anomalous Hall effect of heavy holes in Ⅲ-Ⅴ semiconductor quantum wells
Wang Zhi-Gang; Zhang Ping
2007-01-01
The anomalous Hall effect of heavy holes in semiconductor quantum wells is studied in the intrinsic transport regime, where the Berry curvature governs the Hall current properties. Based on the first-order perturbation of wave function the expression of the Hall conductivity the same as that from the semiclassical equation of motion of the Bloch particles is derived. The dependence of Hall conductivity on the system parameters is shown. The amplitude of Hall conductivity is found to be balanced by a competition between the Zeeman splitting and the spin-orbit splitting.
Kolman, Bernard
1985-01-01
College Algebra, Second Edition is a comprehensive presentation of the fundamental concepts and techniques of algebra. The book incorporates some improvements from the previous edition to provide a better learning experience. It provides sufficient materials for use in the study of college algebra. It contains chapters that are devoted to various mathematical concepts, such as the real number system, the theory of polynomial equations, exponential and logarithmic functions, and the geometric definition of each conic section. Progress checks, warnings, and features are inserted. Every chapter c
A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics.
Huang, Haiyun; Wang, Dejun; Xu, Yue
2015-10-27
This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS) technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW.
Steep Houses in Basic Writing: Advocating for Latino Immigrants in a North Georgia Two-Year College
Salas, Spencer
2012-01-01
Recounting the controversy surrounding a town hall meeting on "illegal" Latino immigration at a two-year college in North Georgia, this ethnographic narrative details the aftermath that ensued and its consequences for an ESL basic writing instructor. Fallout included the potential loss of her job, the rumored reallocation of a $5 million…
Bekker, Marthinus J; Cumming, Tania D; Osborne, Nikola K.P; Bruining, Angela M; McClean, Julia I; Leland, Louis S
2010-01-01
This experiment investigated the combined use of visual prompts, daily feedback, and rewards to reduce electricity consumption in a university residential hall. After a 17-day baseline period, the experimental intervention was introduced in the intervention hall, and no change was made in the control hall. Energy usage decreased in the intervention hall, but energy usage did not change appreciably in the control hall. In the intervention hall, mean daytime and nighttime savings were 16.2% and 10.7%, respectively, compared to savings of 3.8% (day) and 6.5% (night) in the control hall. PMID:21119909
Meron-Pair Excitations in Bilayer Quantum Hall System
Moon, Kyungsun
Bilayer two-dimensional electron gas systems can form unusual broken symmetry states with spontaneous inter-layer phase coherence at certain filling factors. At total filling factor νT = 1, the lowest energy charged excitation of the system is theoretically suggested to be a linearly-confined meron-pair, which is topologically identical to a single skyrmion. We will review how this remarkable excitation arises and can help unravel various experimental results demonstrated in bilayer quantum Hall system. In order to detect the linearly-confined meron-pair excitation directly, we propose a gated bilayer Hall bar experiment, where the magnitude and orientation of magnetic field B‖ applied parallel to the 2D plane can be controlled. We demonstrate a strong angle-dependent transport due to the anisotropic nature of linearly-confined meron-pairs and discuss how it would be manifested in experiment.
Spin rectification induced by spin Hall magnetoresistance at room temperature
Wang, P.; Jiang, S. W.; Luan, Z. Z.; Zhou, L. F.; Ding, H. F.; Zhou, Y.; Tao, X. D.; Wu, D.
2016-09-01
We have experimentally and theoretically investigated the dc voltage generation in the heterostructure of Pt and yttrium iron garnet under the ferromagnetic resonance. Besides a symmetric Lorenz line shape dc voltage, an antisymmetric Lorenz line shape dc voltage is observed in field scan, which can solely originate from the spin rectification effect due to the spin Hall magnetoresistance. The angular dependence of the dc voltage is theoretically analyzed by taking into account both the spin pumping and the spin rectification effects. We find that the experimental results are in excellent agreement with the theoretical model, further identifying the spin Hall magnetoresistance origin of the spin rectification effect. Moreover, the spin pumping and the spin rectification effects are quantitatively separated by their different angular dependence at particular experimental geometry.
Local magnetization fluctuations in superconducting glasses resolved by Hall sensors
Lefebvre, J.; Hilke, M.; Altounian, Z.; West, K. W.; Pfeiffer, L. N.
2009-05-01
We report on magnetization measurements performed on a series of FexNi1-xZr2 superconducting metallic glasses with 0≤x≤0.5 using the Hall effect of a nearby two-dimensional electron gas (2DEG) in a GaAs/Al0.33Ga0.67As heterostructure as a local probe. The great sensitivity of the Hall effect of the 2DEG in such heterostructure is exploited to determine the magnetization of the superconductor due to the Meissner effect and flux trapping. The data are used to determine the lower critical-field Bc1 of the superconductors as a function of temperature. Surprisingly large fluctuations in the magnetization are also observed and attributed to the presence of large flux clusters in the superconductor.
Generalized Surface Polaritons and their quantum spin Hall effect
Xu, Yadong; Chen, Huanyang
2016-01-01
Surface polaritons, e.g., surface plasmon polaritons, are invaluable tools in nanophotonics. However, considerable plasmon loss narrows the application regime of plasmonic devices. Here we reveal some general conditions for lossless surface polaritons to emerge at the interface of a gain and a loss media. The gain medium does not only compensate the energy loss, but also modifies surface wave oscillation mechanisms. A new type of surface polaritons induced by the sign switch of the imaginary part of the permittivity across the interface is discovered. The surface polaritons exhibit spin Hall effect due to spin-momentum locking and unique Berry phase. The spin Hall coefficient changes the sign across the parity-time symmetric limit and becomes quantized for perfect metal-dielectric interface and for dielectric-dielectric interface with very large permittivity contrast, carrying opposite topological numbers. Our study opens a new direction for manipulating light with surface polaritons in non-Hermitian optical ...