Unions, Vitamins, Exercise: Unionized Graduate Students
Dewberry, David R.
2005-01-01
After the turbulent labor history of America in the early to mid twentieth century, there has been a general decline of unions. Nevertheless, many graduate school teaching assistants are unionizing in attempts to gain better pay and benefits and remove themselves from an "Ivory Sweatshop." This article discusses a history of unions…
Students Union, University Administration and Political Development ...
African Journals Online (AJOL)
Students Union, University Administration and Political Development of Nations. ... African Research Review ... resting on the reciprocal determinism of the social learning theory, that students union makes university administration smooth.
A Residential Paradox?: Residence Hall Attributes and College Student Outcomes
Bronkema, Ryan; Bowman, Nicholas A.
2017-01-01
The researchers of this brief observed that few environments have the potential to shape the outcomes of college students as much as residence halls. As a result, residence halls have the capacity to foster a strong sense of community as well as other important outcomes such as college satisfaction and academic achievement. However, given the high…
Involving Students in Residence Halls in Hong Kong
Ting, S. Raymond; Chan, Rebecca; Lee, Esther
2016-01-01
This article reports a study based on A. W. Astin's (1984) involvement theory applied in residence halls at a public university in Hong Kong, China. The resident students who were involved as participants or student leaders in this study were found to be better developed in terms of leadership, career development, multicultural experience,…
Students' Unions, Consumerism and the Neo-Liberal University
Brooks, Rachel; Byford, Kate; Sela, Katherine
2016-01-01
This article explores the economic relationships between individual students' unions and their wider institutions, and the ways in which they articulate with a pervasive consumerist agenda across the higher education sector. We draw on data from a UK-wide study to argue that students' unions have an ambivalent relationship with consumerist…
election malpractice in students union government of nnamdi
African Journals Online (AJOL)
JONATHAN
in student's union government of Nnmadi Azikiwe University Awka. ... Apparently, in the organization and conduct of election, it must be free and fair. ... electoral body and the security, misinformation of date, time and venue, use of electronic ...
Alcohol Trajectories over Three Years in a Swedish Residence Hall Student Population
Directory of Open Access Journals (Sweden)
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.
How to Arrange Student Tours to the Soviet Union.
Winokur, Marshall
The details of planning a student tour to the Soviet Union are described by an experienced tour organizer. Student tours of one to three weeks are presented as rewarding alternatives to lengthy overseas study. Recommendations are made regarding choice of tour type, length of tour, travel agencies, time of year to travel, advertising a tour,…
Geographic Constructions of Race: The Midwest Asian American Students Union
Kodama, Corinne M.; Poon, OiYan A.; Manzano, Lester J.; Sihite, Ester U.
2017-01-01
This case study was focused on the establishment of the Midwest Asian American Students Union (MAASU) as a racial project reflecting students' articulations of a regional, panethnic identity in response to racism. A critical race theory lens was used to analyze interviews with 13 MAASU founders. Findings highlight the role of social context (in…
Students' Sense of Community in Residence Halls, Social Integration, and First-Year Persistence.
Berger, Joseph B.
1997-01-01
Used concepts from community psychology literature to elaborate a revised version of Tinto's model of individual student departure. Employed a longitudinal analysis of 718 college students. Results indicate that students' sense of community in their residence halls was a source of social integration and a precursor to student departure decisions.…
Benoit Jeannet
2011-01-01
23rd August 2011 - Turkish Representatives of the Union of Chambers and Commodity Exchanges, E. Uluatam and S. Kologlu, visiting the LHC superconducting magnet test hall with Engineering Department Head R. Saban.
Students' Perceptions of the Residence Hall Living Environment at Kuwait University
Al Kandari, Nabila
2007-01-01
The purpose of this study is to explore students' perceptions of the residence hall living environment at Kuwait University. The researcher developed a questionnaire for this purpose that included 36 items. The sample of the study consisted of 191 residential students, of whom 98 were male and 93 were female. The research findings indicated that:…
This Year, Colleges Recruited Students in a "Hall of Mirrors"
Hoover, Eric; Supiano, Beckie
2009-01-01
Admissions deans everywhere shared concerns about recruiting students during a recession as they tried to discern how, or if, the economy would affect demand for their institutions. Amid this uncertainty, colleges used many different strategies. Some recruited more here and less there. Some offered more merit aid, while others scaled back. Some…
The effect of hand hygiene on illness rate among students in university residence halls.
White, Cindy; Kolble, Robin; Carlson, Rebecca; Lipson, Natasha; Dolan, Mike; Ali, Yusuf; Cline, Mojee
2003-10-01
Several studies have indicated a connection between hand sanitization and infection control in numerous settings such as extended care facilities, schools, and hospitals. The purpose of this study was to assess the effectiveness of both a hand-hygiene message campaign and the use of an alcohol gel hand sanitizer in decreasing the incidence of upper-respiratory illness among students living in university residence halls. This study involved a total of 430 students recruited from 4 residence halls during the fall semester at the University of Colorado at the Boulder campus. Dormitories were paired into control and product groups. In the product groups, alcohol gel hand-sanitizer dispensers were installed in every room, bathroom, and dining hall. The data were statistically analyzed for the differences between product and control groups in reported symptoms, illness rates, and absenteeism from classes. The overall increase in hand-hygiene behavior and reduction in symptoms, illness rates, and absenteeism between the product group and control group was statistically significant. Reductions in upper respiratory-illness symptoms ranged from 14.8% to 39.9%. Total improvement in illness rate was 20%. The product group had 43% less missed school/work days. Hand-hygiene practices were improved with increased frequency of handwashing through increasing awareness of the importance of hand hygiene, and the use of alcohol gel hand sanitizer in university dormitories. This resulted in fewer upper respiratory-illness symptoms, lower illness rates, and lower absenteeism.
Dispersed or destroyed: archives, the West Indian Students' Union, and public memory
Clover, David
2005-01-01
I wish to address a gap in the recorded history of the Caribbean and the United Kingdom, and describe how information professionals and historians can work together, to reclaim a history before it is lost. \\ud The West Indian Students’ Union was formed in 1945 with the expansion in the number of students arriving in London for further and higher education. Acting as a welfare, political and social organisation the union represented students and their interests as students, as (predominantly) ...
Amber, Khuram Pervez; Aslam, Muhammad Waqar
2018-03-01
Student residence halls occupy 26% of the total area of a typical university campus in the UK and are directly responsible for 24% of university's annual CO2 emissions. Based on five years measured data, this paper aims to investigate the energy-related environmental and economic performance of electrically heated residence halls in which space heating is provided by two different types of electric heaters, that is, panel heater (PHT) and storage heater (SHT). Secondly, using statistical and machine learning methods, the paper attempts to investigate the relationship between daily electricity consumption and five factors (ambient temperature, solar radiation, relative humidity, wind speed and type of day). Data analysis revealed that electricity consumption of both halls is mainly driven by ambient temperature only, whereas SHT residence has 39% higher annual electricity bill and emits 70% higher CO2 emissions on a per square metre basis compared to the PHT residence hall.
Student internships with unions and workers: building the occupational health and safety movement.
Bateson, Gail
2013-01-01
One of the most successful programs to recruit young professionals to the occupational safety and health field was launched more than 35 years ago, in 1976. Created by the Montefiore Medical Center's Department of Social Medicine collaborating with Tony Mazzocchi of the Oil, Chemical and Atomic Workers International Union (OCAW), it placed medical, nursing, and public health students in summer internships with local unions to identify and solve health and safety problems in the workplace. The experience of working with and learning from workers about the complex interactions of political, economic, and scientific-technological issues surrounding workplace conditions inspired many students to enter and stay in our field. Many former interns went on to make important medical and scientific contributions directly linked to their union-based projects. Former interns are now among the leaders within the occupational health and safety community, holding key positions in leading academic institutions and governmental agencies.
[Student Magazine of the ESL Classes of the International Ladies' Garment Workers' Union (ILGWU).
Alvarez, Manuel, Ed.; Zetino, Alfredo, Ed.
This student magazine created by the English-as-a-Second-Language (ESL) classes of the International Ladies' Garment Workers' Union (ILGWU) is a collection of personal opinions, reports, and creative writing with illustrations. Each item was written as a voluntary collaboration, homework, or classwork. Items include poems, letters, accounts of…
Style of Life and Student Personnel Policy in College Residence Halls
White, Julie E.
1969-01-01
Doctoral dissertation, Dimensions of Conformity and Evasion in Residence Halls for University Women: A Sociological Analysis of Normative Behavior in a Large-Scale Social Organization, 1962, University of Illinois, Urbana.
Directory of Open Access Journals (Sweden)
Ozge Yavuz Sari
2015-04-01
Full Text Available AIM: Sleep disorders are remarkable public health problems as they adversely affect physical, mental and social health and may cause accidents and decline in academic performance and labor productivity. Aim of the study is assessing sleep quality and determining some factors affecting sleep quality in the students living in the residence hall of a university. METHOD: It is a cross sectional study conducted with 277 students, 180 of whom are female. Data were collected via a questionnaire including Pittsburgh Sleep Quality Index (PSQI, Epworth Sleepiness Scale (ESS and socio-demographic characteristics query. RESULTS: According to PSQI, 41.1% of students have bad sleep quality. Sleep quality of male students and students who are overweight/obese or living in more crowded rooms in the hall of residence is worse than other students and #8217;. Prevalence of bad sleep quality is higher in medication users, participants thinking that they have problems in sleeping or falling asleep and had stressful experience in the last month. The differences between groups were statistically significant. In logistic regression analyzes, using medication (OR=2.54, having problems in sleep (OR=12.75, having problems in falling asleep (OR=8.83 and bad experiences in the last month (OR=2.66 have effects on sleep quality. CONCLUSIONS: Interventions about sleep disorders are important due to their preventable characteristics. Developing healthy life habits, improving physical conditions and coping with stress will be effective on preventing and treating sleep disorders. [TAF Prev Med Bull 2015; 14(2.000: 93-100
The relationship between burnout and mood state among student rugby union players
Grobbelaar, H.W.; Malan, D.D.J.; Steyn, B.J.M.; Ellis, S.M.
2011-01-01
Mood state changes are widely regarded as a symptom of athlete burnout and show potential to be used as a marker for this condition. The aim of this study was to determine whether changes in burnout scores would be accompanied by similar changes in mood state scores, and to determine the strength of the relationship between burnout and mood state scores at different test points. Forty-one male student rugby union players (mean age: 22.26 ± 1.39 years) completed the Athlete Burnout Questionnai...
Seabourg, Deborah; And Others
At the beginning of the 1973-74 academic year alcohol usage was officially permitted for the first time in residence halls at the Twin Cities Campus of the University of Minnesota. To determine residents' perceptions of the effects of the change in drinking policy, interviews were conducted with 49 current dormitory residents, who had also lived…
Moore, Graham F; Williams, Annie; Moore, Laurence; Murphy, Simon
2013-04-18
This exploratory trial examines the feasibility of implementing a social norms marketing campaign to reduce student drinking in universities in Wales, and evaluating it using cluster randomised trial methodology. Fifty residence halls in 4 universities in Wales were randomly assigned to intervention or control arms. Web and paper surveys were distributed to students within these halls (n = 3800), assessing exposure/contamination, recall of and evaluative responses to intervention messages, perceived drinking norms and personal drinking behaviour. Measures included the Drinking Norms Rating Form, the Daily Drinking Questionnaire and AUDIT-C. A response rate of 15% (n = 554) was achieved, varying substantially between sites. Intervention posters were seen by 80% and 43% of students in intervention and control halls respectively, with most remaining materials seen by a minority in both groups. Intervention messages were rated as credible and relevant by little more than half of students, though fewer felt they would influence their behaviour, with lighter drinkers more likely to perceive messages as credible. No differences in perceived norms were observed between intervention and control groups. Students reporting having seen intervention materials reported lower descriptive and injunctive norms than those who did not. Attention is needed to enhancing exposure, credibility and perceived relevance of intervention messages, particularly among heavier drinkers, before definitive evaluation can be recommended. A definitive evaluation would need to consider how it would achieve sufficient response rates, whilst hall-level cluster randomisation appears subject to a significant degree of contamination. ISRCTN: ISRCTN48556384.
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...
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...
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…
The Witnesses Walk Your Halls: The School Counselor and Student Victims of Domestic Violence.
Refvem, Joanna
More than three million children witness domestic violence each year. School counselors need to understand the dynamics of domestic violence, learn the most effective assessments of violence in the lives of their students, and be familiar with the interventions that can be implemented. External stresses on the family do not appear to influence the…
A Reflection on Educating College Students about the Value of Public-Sector Unions
Mooney, Christine; Volchok, Edward
2016-01-01
This year, labor unions got a reprieve: The Supreme Court deadlocked in a much-anticipated case that could have turned almost every state into Wisconsin, where partisan interests have crippled union power. The case, "Friedrichs vs. California Teachers Association," addressed a previous case, "Abood v. Detroit Board of…
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. Copyright © 2011 Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Anne Charlotte Behler
2008-06-01
Full Text Available The Web 2.0 generation presents many service challenges to libraries. College students of today have work styles that emphasize collaboration, preference for flexible and comfortable spaces, and independent discovery of information. Given that challenge, it is important for libraries to experiment with new and unique models of service. Librarians and Staff at the Penn State University Libraries explored offering library service at the main campus’s student union building during two trials, during the Spring and Fall semesters of 2006.
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 new science competition for secondary school students : the First European Union Science Olympiad
van Kampen, P; Browne, WR; Burke, M; Cotter, MA; James, P; McGlynn, E; O'Kennedy, R; Smyth, P; Whelan, G
The first European Union Science Olympiad (EUSO2003) took place at Dublin City University in April 2003. In this paper we discuss the philosophy behind and implementation of this new competition, and the role third-level institutions can play in making science more attractive to second-level
Teachers Unions and Management Partnerships: How Working Together Improves Student Achievement
Rubinstein, Saul A.; McCarthy, John E.
2014-01-01
For more than a decade, the debate over public school reform has created friction between teachers unions, administrators, school boards, parents, policymakers, and other stakeholders in public education and has fueled disagreements over how to improve the quality of teaching and learning for children. While many factors make consensus elusive…
Experimental halls workshop summary
International Nuclear Information System (INIS)
Thorndike, A.
1976-01-01
A brief discussion is given of: (1) pros and cons of open areas as compared with enclosed halls; (2) experimental hall needs of ep, anti p p, and other options; (3) hall for the lepton detector; and, (4) hall for the hadron spectrometer
Experimental halls workshop summary
International Nuclear Information System (INIS)
Thorndike, A.
1976-01-01
On May 26 and 27, 1976, approximately 50 people met for an informal workshop on plans for experimental halls for ISABELLE. Plans as they exist in the May 1976 version of the ISABELLE proposal were presented. Discussions were held on the following four general topics by separate working groups: (1) pros and cons of open areas as compared with enclosed halls; (2) experimental hall needs of ep, anti pp, and other options; (3) hall for the lepton detector; and (4) hall for the hadron spectrometer. The planning for experimental halls at PEP, the hall for the lepton detector, the hadron spectrometer, and open areas are discussed
Experimental halls workshop summary
International Nuclear Information System (INIS)
Thorndike, A.
1976-01-01
At the experimental halls workshop, discussions were held on: (1) open areas as compared with enclosed halls; (2) the needs of ep, anti pp, and other options; (3) the hall for the lepton detector; and (4) the hall for the hadron spectrometer. The value of different possibilities for the future experimental program was explored. A number of suggestions emerged which will be used as the design of the experimental halls progresses
The Ideas of the Students of Education Faculty about the European Union Education and Youth Programs
Ergün, Muammer; Kamer, S. Tunay
2009-01-01
The most important issue that Turkey has been dealing with since the beginning of 2000s is the entrance to the European Union and the preparatory activities for this period. No what how it is evaluated, as an opportunity or a threat to which will break us off our cultural values, EU is a reality that our country faces. The programs such as FORCE,…
DEFF Research Database (Denmark)
Caudery, Tim; Petersen, Margrethe; Shaw, Philip
' language learning and use in study abroad contexts. The study involves exchange students - but not language students - at four Scandinavian universities - two traditional ones and two specialised ones. Data for the project, which closes at the end of 2007, were collected through semi-structured individual...
Witecki, Gwendolyn; Nonnecke, Blair
2015-01-01
Universities have experienced increases in technology ownership and usage amongst students entering undergraduate programs. Almost all students report owning a mobile phone and many students view laptops and tablets as educational tools, though they also report using them for nonacademic activities during lectures. We explored the relationship…
Directory of Open Access Journals (Sweden)
Gwendolyn Witecki
2015-01-01
Full Text Available Universities have experienced increases in technology ownership and usage amongst students entering undergraduate programs. Almost all students report owning a mobile phone and many students view laptops and tablets as educational tools, though they also report using them for non-academic activities during lectures. We explored the relationship between student course engagement and the use of smartphones, laptops, cell phones, and tablets during lecture. Undergraduate students responded to an online survey asking about both course engagement and mobile device habits. Results show that smartphone use was most strongly related to lowered course engagement and while laptop use was related to lowered engagement, it was to a lesser extent. In contrast, overall engagement of students using tablets or cell phones was not significantly different than those who did not.
Genicot, Geneviève
2012-01-01
Similarities between French and Italian political culture of student representation include a conflictual culture in a weak national system of intermediation of interests, and a mimetic relationship with national conflictual party politics. New international topics, such as the Bologna Process or the growing commodification of education, have…
Cryogenic microsize Hall sensors
International Nuclear Information System (INIS)
Kvitkovic, J.; Polak, M.
1993-01-01
Hall sensors have a variety of applications in magnetic field measurements. The active area of the Hall sensor does not play an important role in measuring of homogeneous magnetic field. Actually Hall sensors are widely used to measure profiles of magnetic fields produced by magnetization currents in samples of HTC superconductors, as well as of LTC ones. Similar techniques are used to measure magnetization of both HTC and LTC superconductors. In these cases Hall sensor operates in highly inhomogeneous magnetic fields. Because of that, Hall sensors with very small active area are required. We developed and tested Hall sensors with active area 100 μm x 100 μm - type M and 50 μm x 50 μm - type V. Here we report on the most imporant parameters of these units, as well as on their properties as differential magnetometer. (orig.)
Kim, Bom Soo
2018-05-01
We discuss the contribution of magnetic Skyrmions to the Hall viscosity and propose a simple way to identify it in experiments. The topological Skyrmion charge density has a distinct signature in the electric Hall conductivity that is identified in existing experimental data. In an electrically neutral system, the Skyrmion charge density is directly related to the thermal Hall conductivity. These results are direct consequences of the field theory Ward identities, which relate various physical quantities based on symmetries and have been previously applied to quantum Hall systems.
International Nuclear Information System (INIS)
Schaller, K.
1995-01-01
Different instruments used by European Commission of the European Union for financial support radioactive waste management activities in the Russian Federation are outlined. Three particular programmes in the area are described
Schachter, Ron
2010-01-01
This article explores school districts such as New Haven (Connecticut) Public Schools, whose local union is an American Federation of Teachers (AFT) affiliate and where a shared concern for students has trumped the often adversarial union-management relationship. The author discusses what makes the successful contract negotiations headed by David…
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...
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...
International Nuclear Information System (INIS)
El-Arabi, N. M.
1993-01-01
Transport phenomena in two dimensional semiconductors have revealed unusual properties. In this thesis these systems are considered and discussed. The theories explain the Integral Quantum Hall Effect (IQHE) and the Fractional Quantum Hall Effect (FQHE). The thesis is composed of five chapters. The first and the second chapters lay down the theory of the IQHE, the third and fourth consider the theory of the FQHE. Chapter five deals with the statistics of particles in two dimension. (author). Refs
Hall viscosity of hierarchical quantum Hall states
Fremling, M.; Hansson, T. H.; Suorsa, J.
2014-03-01
Using methods based on conformal field theory, we construct model wave functions on a torus with arbitrary flat metric for all chiral states in the abelian quantum Hall hierarchy. These functions have no variational parameters, and they transform under the modular group in the same way as the multicomponent generalizations of the Laughlin wave functions. Assuming the absence of Berry phases upon adiabatic variations of the modular parameter τ, we calculate the quantum Hall viscosity and find it to be in agreement with the formula, given by Read, which relates the viscosity to the average orbital spin of the electrons. For the filling factor ν =2/5 Jain state, which is at the second level in the hierarchy, we compare our model wave function with the numerically obtained ground state of the Coulomb interaction Hamiltonian in the lowest Landau level, and find very good agreement in a large region of the complex τ plane. For the same example, we also numerically compute the Hall viscosity and find good agreement with the analytical result for both the model wave function and the numerically obtained Coulomb wave function. We argue that this supports the notion of a generalized plasma analogy that would ensure that wave functions obtained using the conformal field theory methods do not acquire Berry phases upon adiabatic evolution.
International Nuclear Information System (INIS)
Klitzing von, K.
1989-01-01
The quantized Hall effect is theoretically explained in detail as are its basic properties. The explanation is completed with the pertinent mathematical relations and illustrative figures. Experimental data are critically assessed obtained by quantum transport measurement in a magnetic field on two-dimensional systems. The results are reported for a MOSFET silicon transistor and for GaAs-Al x Ga 1-x As heterostructures. The application is discussed of the quantized Hall effect in determining the fine structure constant or in implementing the resistance standard. (M.D.). 27 figs., 57 refs
Intrinsic superspin Hall current
Linder, Jacob; Amundsen, Morten; Risinggârd, Vetle
2017-09-01
We discover an intrinsic superspin Hall current: an injected charge supercurrent in a Josephson junction containing heavy normal metals and a ferromagnet generates a transverse spin supercurrent. There is no accompanying dissipation of energy, in contrast to the conventional spin Hall effect. The physical origin of the effect is an antisymmetric spin density induced among transverse modes ky near the interface of the superconductor arising due to the coexistence of p -wave and conventional s -wave superconducting correlations with a belonging phase mismatch. Our predictions can be tested in hybrid structures including thin heavy metal layers combined with strong ferromagnets and ordinary s -wave superconductors.
International Nuclear Information System (INIS)
Avdonin, A.; Skupiński, P.; Grasza, K.
2016-01-01
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.
Energy Technology Data Exchange (ETDEWEB)
Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)
2016-02-15
A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.
Growing Up Gifted in the Soviet Union.
Stevens, Robert E.
1987-01-01
A review of the educational program for gifted students in the Soviet Union discusses student responsibilities, program admission, and specialized schools featuring foreign languages, mathematics and physics, music, ballet and arts, sports, and "little academics" (advanced studies). (CB)
Granberg, Donald; Brown, Thad A.
1995-01-01
Examines people's behavior in the Monty Hall Dilemma (MHD), in which a person must make two decisions to win a prize. In a series of five studies, found that people misapprehend probabilities in the MHD. Discusses the MHD's relation to illusion of control, belief perseverance, and the status quo bias. (RJM)
Laurent Guiraud
2000-01-01
General view of the Isotope-Separator On-Line (ISOLDE) hall. ISOLDE is dedicated to the production of a large variety of radioactive ion beams for many different experiments. Rare isotopes can be produced allowing the study of spectra for neutrino beam production.
Czech Academy of Sciences Publication Activity Database
Nagaosa, N.; Sinova, Jairo; Onoda, S.; MacDonald, A. H.; Ong, N. P.
2010-01-01
Roč. 82, č. 2 (2010), s. 1539-1592 ISSN 0034-6861 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 51.695, year: 2010
Directory of Open Access Journals (Sweden)
Khuram Pervez Amber
2018-06-01
Full Text Available University buildings, such as student residence halls with year-round consistent energy demands, offer strong opportunities for Combined Heat and Power (CHP systems. The economic and environmental feasibility of a CHP project is strongly linked with its optimum sizing. This study aims to undertake such an assessment for a CHP system for a student residence hall located in London, the United Kingdom (UK. The study also aims to undertake a sensitivity analysis to investigate the effect of different parameters on the project’s economics. Necessary data are collected via interviews with the University’s Energy Manager. Modeling of the CHP system is performed using the London South Bank University (LSBU, London, the UK CHP model. Results demonstrate that optimum sizing of CHP is crucial for achieving higher economic and environmental benefits and strongly depends on the authenticity of the energy consumption data, based on which the CHP is being sized. Use of incorrect energy data could result in an undersized or oversized CHP system, where an oversized system will result in higher negative results compared to an undersized system. Finally, Monto Carlo statistical analysis shows that electricity price is the significant factor that could affect the project’s economics. With an increasing spark gap, the payback period decreases, and vice versa.
Amin, Rucha; Teli, Despoina; James, Patrick; Bourikas, Leonidas
2016-01-01
Adaptive comfort theory states that over time people adapt to their normal environment. Therefore, people from different climates are expected to have different thermal preferences and behaviours, which could lead to ‘performance gap’ in buildings with occupants of diverse climate backgrounds. This study investigates the influence of occupants’ thermal history on use of controls and indoor temperature preference in a newly built halls of residence building complex in Southampton, UK, which pr...
Sinova, Jairo; Valenzuela, Sergio O.; Wunderlich, J.; Back, C. H.; Jungwirth, T.
2015-10-01
Spin Hall effects are a collection of relativistic spin-orbit coupling phenomena in which electrical currents can generate transverse spin currents and vice versa. Despite being observed only a decade ago, these effects are already ubiquitous within spintronics, as standard spin-current generators and detectors. Here the theoretical and experimental results that have established this subfield of spintronics are reviewed. The focus is on the results that have converged to give us the current understanding of the phenomena, which has evolved from a qualitative to a more quantitative measurement of spin currents and their associated spin accumulation. Within the experimental framework, optical-, transport-, and magnetization-dynamics-based measurements are reviewed and linked to both phenomenological and microscopic theories of the effect. Within the theoretical framework, the basic mechanisms in both the extrinsic and intrinsic regimes are reviewed, which are linked to the mechanisms present in their closely related phenomenon in ferromagnets, the anomalous Hall effect. Also reviewed is the connection to the phenomenological treatment based on spin-diffusion equations applicable to certain regimes, as well as the spin-pumping theory of spin generation used in many measurements of the spin Hall angle. A further connection to the spin-current-generating spin Hall effect to the inverse spin galvanic effect is given, in which an electrical current induces a nonequilibrium spin polarization. This effect often accompanies the spin Hall effect since they share common microscopic origins. Both can exhibit the same symmetries when present in structures comprising ferromagnetic and nonmagnetic layers through their induced current-driven spin torques or induced voltages. Although a short chronological overview of the evolution of the spin Hall effect field and the resolution of some early controversies is given, the main body of this review is structured from a pedagogical
International Nuclear Information System (INIS)
Greiter, M.
1992-01-01
This dissertation contains a collection of individual articles on various topics. Their significance in the corresponding field as well as connections between them are emphasized in a general and comprehensive introduction. In the first article, the author explores the consequences for macroscopic effective Lagrangians of assuming that the momentum density is proportional to the flow of conserved current. The universal corrections obtained for the macroscopic Lagrangian of a superconductor describe the London Hall effect, and provide a fully consistent derivation of it. In the second article, a heuristic principle is proposed for quantized Hall states: the existence and incompressibility of fractionally quantized Hall states is explained by an argument based on an adiabatic localization of magnetic flux, the process of trading uniform flux for an equal amount of fictitious flux attached to the particles. This principle is exactly implemented in the third article. For a certain class of model Hamiltonians, the author obtains Laughlin's Jastrow type wave functions explicitly from a filled Landau level, by smooth extrapolation in quantum statistics. The generalization of this analysis to the torus geometry shows that theorems restricting the possibilities of quantum statistics on closed surfaces are circumvented in the presence of a magnetic field. In the last article, the existence is proposed of a novel incompressible quantum liquid, a paired Hall state, at a half filled Landau level. This state arises adiabatically from free fermions in zero magnetic field, and reduces to a state previously proposed by Halperin in the limit of tightly bound pairs. It supports unusual excitations, including neutral fermions and charge e/4 anyons with statistical parameter θ = π/8
Energy Technology Data Exchange (ETDEWEB)
1984-08-01
This report demonstrates the economic viability of an exterior rewrap retrofit performed on a public community facility for the performing arts. This facility originally consisted of two mess halls built by the American army. The exterior retrofit consisted of constructing a super-insulated passageway to link the two halls as well as completely wrapping the facility with six millimetre polyethylene to provide an airtight barrier. The roofs and walls were reinsulated and insulation levels were increased to RSI 10.5 in the ceilings and RSI 7.7 in the walls. The installation of a propane fuelled furnace was also included in the retrofit package. Prior to the renovations and retrofitting, the Guild Hall facility was almost unusable. The demonstration project transformed the cold, drafty buildings into an attractive, comfortable and functional centre for the performing arts. Heating requirements have been reduced to 500 MJ/m {sup 2} of floor space annually compared to a predicted 1,760 MJ/m{sup 2} of floor space based on HOTCAN analysis of the heating requirements without the energy conservation measures. 9 figs., 10 tabs.
Quantum critical Hall exponents
Lütken, C A
2014-01-01
We investigate a finite size "double scaling" hypothesis using data from an experiment on a quantum Hall system with short range disorder [1-3]. For Hall bars of width w at temperature T the scaling form is w(-mu)T(-kappa), where the critical exponent mu approximate to 0.23 we extract from the data is comparable to the multi-fractal exponent alpha(0) - 2 obtained from the Chalker-Coddington (CC) model [4]. We also use the data to find the approximate location (in the resistivity plane) of seven quantum critical points, all of which closely agree with the predictions derived long ago from the modular symmetry of a toroidal sigma-model with m matter fields [5]. The value nu(8) = 2.60513 ... of the localisation exponent obtained from the m = 8 model is in excellent agreement with the best available numerical value nu(num) = 2.607 +/- 0.004 derived from the CC-model [6]. Existing experimental data appear to favour the m = 9 model, suggesting that the quantum Hall system is not in the same universality class as th...
Topological Hall and Spin Hall Effects in Disordered Skyrmionic Textures
N'diaye, P. B.; Akosa, C. A.; Manchon, A.
2016-01-01
We carry out a throughout 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-B\\"uttiker 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 found that the adiabatic a...
Quantum hall effect. A perspective
International Nuclear Information System (INIS)
Aoki, Hideo
2006-01-01
Novel concepts and phenomena are emerging recently in the physics of quantum Hall effect. This article gives an overview, which starts from the fractional quantum Hall system viewed as an extremely strongly correlated system, and move on to present various phenomena involving internal degrees of freedom (spin and layer), non-equilibrium and optical properties, and finally the spinoff to anomalous Hall effect and the rotating Bose-Einstein condensate. (author)
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.
Czech Academy of Sciences Publication Activity Database
Wunderlich, Joerg; Park, B.G.; Irvine, A.C.; Zarbo, Liviu; Rozkotová, E.; Němec, P.; Novák, Vít; Sinova, Jairo; Jungwirth, Tomáš
2010-01-01
Roč. 330, č. 6012 (2010), s. 1801-1804 ISSN 0036-8075 R&D Projects: GA AV ČR KAN400100652; GA MŠk LC510 EU Projects: European Commission(XE) 215368 - SemiSpinNet Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : spin Hall effect * spintronics * spin transistor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 31.364, year: 2010
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…
Quantum Hall Electron Nematics
MacDonald, Allan
In 2D electron systems hosted by crystals with hexagonal symmetry, electron nematic phases with spontaneously broken C3 symmetry are expected to occur in the quantum Hall regime when triplets of Landau levels associated with three different Fermi surface pockets are partially filled. The broken symmetry state is driven by intravalley Coulombic exchange interactions that favor spontaneously polarized valley occupations. I will discuss three different examples of 2D electron systems in which this type of broken symmetry state is expected to occur: i) the SnTe (111) surface, ii) the Bi (111) surface. and iii) unbalanced bilayer graphene. This type of quantum Hall electron nematic state has so far been confirmed only in the Bi (111) case, in which the anisotropic quasiparticle wavefunctions of the broken symmetry state were directly imaged. In the SnTe case the nematic state phase boundary is controlled by a competition between intravalley Coulomb interactions and intervalley scattering processes that increase in relative strength with magnetic field. An in-plane Zeeman field alters the phase diagram by lifting the three-fold Landau level degeneracy, yielding a ground state energy with 2 π/3 periodicity as a function of Zeeman-field orientation angle. I will comment on the possibility of observing similar states in the absence of a magnetic field. Supported by DOE Division of Materials Sciences and Engineering Grant DE-FG03-02ER45958.
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...
Energy consumption of sport halls
Energy Technology Data Exchange (ETDEWEB)
1983-01-01
The energy consumption of Finland's sports halls (ball games halls, ice hockey halls and swimming halls) represent approximately 1% of that of the country's whole building stock. In the light of the facts revealed by the energy study the potential energy saving rate in sports halls is 15-25%. The total savings would be something like FIM 30-40 million per annum, of which about a half would be achieved without energy-economic investments only by changing utilization habits and by automatic control measures. The energy-economic investments are for the most part connected with ventilation and their repayment period is from one to five years. On the basis of the energy study the following specific consumption are presented as target values: swimming halls: heat (kWh/m*H3/a)100, electricity (kWh/m*H3/a)35, water (l/m*H3/a)1000 icehockey halls (warm): heat (kWh/m*H3/a)25, electricity (kWh/m*H3/a)15, water (l/m*H3/a)200, ball games halls (multi-purpose halls): heat (kWh/m*H3/a)30, electricity (kWh/m*H3/a)25, water (l/m*H3/a)130. In the study the following points proved to be the central areas of energy saving in sports halls: 1. Flexible regulation of the temperature in sports spaces on the basis of the sport in question. 2. The ventilation of swimming halls should be adjusted in such a way that the humidity of the hall air would comply with the limit humidity curve determined by the quality of structures and the temperature of the outdoor air. 3. An ice skating hall is an establishment producing condensing energy from 8 to 9 months a year worth of approx. 100.000-150.000 Finnmarks. The development of the recovery of condensing energy has become more important. 4. The ventilation of ball games halls may account for over 50% of the energy consumption of the whole building. Therefore special attention should be paid to the optimatization of ventilation as a whole.
Sargeant, Marcel Andre Almont
Problem. Science education has long been a great concern in the United States, where less than one-third of the students perform at or above the proficient level. The purpose of this study was to investigate the status of the science program in a selected Union Conference of the Seventh-day Adventist school system. Specifically, this study investigated the perceptions of teachers and students regarding the extent to which the science program meets the criteria of the National Commission on Mathematics and Science Teaching for the 21st century and to what extent these criteria are related to academic performance as indicated by Iowa Test of Basic Skills (ITBS) science scores. Method. Two questionnaires designed by the researcher were used to get responses from 424 students in seventh and eighth grades and 68 teachers to see how this school system compares to the criteria of National Commission on Mathematics and Science Teaching for the 21 st century. Three classroom configurations were investigated in this study, namely: (a) multigrade, (b) two-grade, and (c) single-grade. Crosstabulation, one-way analysis of variance, Kruskal-Wallis test, and linear regression were used to analyze the four research questions of this study. Results. The single-grade classroom configuration received a better rating for the science criteria (p century. Conclusions. The differences in teaching practices explained the discrepancies in the three classroom configurations. Schools can therefore develop policies and strategies to improve the practices in the teaching and learning process in science education that were identified as being deficient by the criteria of National Commission on Mathematics and Science Teaching for the 21st century.
Scanning vector Hall probe microscopy
International Nuclear Information System (INIS)
Cambel, V.; Gregusova, D.; Fedor, J.; Kudela, R.; Bending, S.J.
2004-01-01
We have developed a scanning vector Hall probe microscope for mapping magnetic field vector over magnetic samples. The microscope is based on a micromachined Hall sensor and the cryostat with scanning system. The vector Hall sensor active area is ∼5x5 μm 2 . It is realized by patterning three Hall probes on the tilted faces of GaAs pyramids. Data from these 'tilted' Hall probes are used to reconstruct the full magnetic field vector. The scanning area of the microscope is 5x5 mm 2 , space resolution 2.5 μm, field resolution ∼1 μT Hz -1/2 at temperatures 10-300 K
International Nuclear Information System (INIS)
Shen, M.C.; Ebel, D.
1987-01-01
In this paper some new results concerning magnetohydrodynamic (MHD) equations with the Hall current (HC) term in the Ohm's law are presented. For the cylindrical pinch of a compressible HC fluid, it is found that for large time and long wave length the solution to the governing equations exhibits the behavior of solitons as in the case of an ideal MHD model. In some special cases, the HC model appears to be better posed. An open question is whether a simple toroidal equilibrium of an HC fluid with resistivity and viscosity exists. The answer to this question is affirmative if the prescribed velocity on the boundary has a small norm. Furthermore, the equilibrium is also linearly and nonlinearly stable
Cassidy, David C.
2013-03-01
It's July 1945. Germany is in defeat and the atomic bombs are on their way to Japan. Under the direction of Samuel Goudsmit, the Allies are holding some of the top German nuclear scientists-among them Heisenberg, Hahn, and Gerlach-captive in Farm Hall, an English country manor near Cambridge, England. As secret microphones record their conversations, the scientists are unaware of why they are being held or for how long. Thinking themselves far ahead of the Allies, how will they react to the news of the atomic bombs? How will these famous scientists explain to themselves and to the world their failure to achieve even a chain reaction? How will they come to terms with the horror of the Third Reich, their work for such a regime, and their behavior during that period? This one-act play is based upon the transcripts of their conversations as well as the author's historical work on the subject.
International Nuclear Information System (INIS)
Joynt, R.J.
1982-01-01
A general investigation of the electronic structure of two dimensional systems is undertaken with a view towards understanding the quantum Hall effect. The work is limited to the case of a strong perpendicular magnetic field, with a disordered potential and an externally applied electric field. The electrons are treated as noninteracting. First, the scattering theory of the system is worked out. The surprising result is found that a wavepacket will reform after scattering from an isolated potential. Also it will tend to be accelerated in the neighborhood of the scatterer if the potential has bound states. Fredholm theory can then be used to show that the extended states carry an additional current which compensates for the zero current of the bound states. Together, these give the quantized conductance. The complementary case of a smooth random potential is treated by a path-integral approach which exploits the analogies to the classical equations of motion. The Green's function can be calculated approximately, which gives the general character of both the bound and extended states. Also the ratio of these two types of states can be computed for a given potential. The charge density is uniform in first approximation, and the Hall conductance is quantized. Higher-order corrections for more rapidly fluctuating potential are calculated. The most general conditions under which the conductance is quantized are discussed. Because of the peculiar scattering properties of the system, numerical solution of the Schroedinger equation is of interest, both to confirm the analytical results, and for pedagogical reasons. The stability and convergence problems inherent in the computer solution of the problem are analyzed. Results for some model scattering potentials are presented
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; Akosa, Collins Ashu; Manchon, Aurelien
2017-01-01
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.
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
Energy Technology Data Exchange (ETDEWEB)
Zhang, J. Y.; Yang, G. [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, S. G., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, J. L. [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang, R. M. [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Amsellem, E.; Kohn, A. [Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Yu, G. H., E-mail: sgwang@iphy.ac.cn, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)
2015-04-13
Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.
The Role of Social Influence on How Residence Hall Inhabitants Respond to Fire Alarms
Leytem, Michael; Stark, Emily
2016-01-01
College resident halls pose a threat for a catastrophic event in the case of fire, but little research has examined potential influences on students' responses to fire alarms, particularly the role of social influence in affecting their behaviors. In the current study, residence hall inhabitants reported their knowledge about fire safety, their…
Nagaosa, Naoto; Sinova, Jairo; Onoda, Shigeki; MacDonald, A. H.; Ong, N. P.
2010-04-01
The anomalous Hall effect (AHE) occurs in solids with broken time-reversal symmetry, typically in a ferromagnetic phase, as a consequence of spin-orbit coupling. Experimental and theoretical studies of the AHE are reviewed, focusing on recent developments that have provided a more complete framework for understanding this subtle phenomenon and have, in many instances, replaced controversy by clarity. Synergy between experimental and theoretical works, both playing a crucial role, has been at the heart of these advances. On the theoretical front, the adoption of the Berry-phase concepts has established a link between the AHE and the topological nature of the Hall currents. On the experimental front, new experimental studies of the AHE in transition metals, transition-metal oxides, spinels, pyrochlores, and metallic dilute magnetic semiconductors have established systematic trends. These two developments, in concert with first-principles electronic structure calculations, strongly favor the dominance of an intrinsic Berry-phase-related AHE mechanism in metallic ferromagnets with moderate conductivity. The intrinsic AHE can be expressed in terms of the Berry-phase curvatures and it is therefore an intrinsic quantum-mechanical property of a perfect crystal. An extrinsic mechanism, skew scattering from disorder, tends to dominate the AHE in highly conductive ferromagnets. The full modern semiclassical treatment of the AHE is reviewed which incorporates an anomalous contribution to wave-packet group velocity due to momentum-space Berry curvatures and correctly combines the roles of intrinsic and extrinsic (skew-scattering and side-jump) scattering-related mechanisms. In addition, more rigorous quantum-mechanical treatments based on the Kubo and Keldysh formalisms are reviewed, taking into account multiband effects, and demonstrate the equivalence of all three linear response theories in the metallic regime. Building on results from recent experiment and theory, a
Department of Homeland Security — The National Credit Union Administration (NCUA) is the independent federal agency that charters and supervises federal credit unions. NCUA, backed of the full faith...
Planar Hall effect bridge magnetic field sensors
DEFF Research Database (Denmark)
Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.
2010-01-01
Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... Hall effect bridge sensors....
Gauge invariance and fractional quantized Hall effect
International Nuclear Information System (INIS)
Tao, R.; Wu, Y.S.
1984-01-01
It is shown that gauge invariance arguments imply the possibility of fractional quantized Hall effect; the Hall conductance is accurately quantized to a rational value. The ground state of a system showing the fractional quantized Hall effect must be degenerate; the non-degenerate ground state can only produce the integral quantized Hall effect. 12 references
"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
Directory of Open Access Journals (Sweden)
Bamshad Michael J
2009-03-01
Full Text Available Abstract Sheldon-Hall syndrome (SHS is a rare multiple congenital contracture syndrome characterized by contractures of the distal joints of the limbs, triangular face, downslanting palpebral fissures, small mouth, and high arched palate. Epidemiological data for the prevalence of SHS are not available, but less than 100 cases have been reported in the literature. Other common clinical features of SHS include prominent nasolabial folds, high arched palate, attached earlobes, mild cervical webbing, short stature, severe camptodactyly, ulnar deviation, and vertical talus and/or talipes equinovarus. Typically, the contractures are most severe at birth and non-progressive. SHS is inherited in an autosomal dominant pattern but about half the cases are sporadic. Mutations in either MYH3, TNNI2, or TNNT3 have been found in about 50% of cases. These genes encode proteins of the contractile apparatus of fast twitch skeletal muscle fibers. The diagnosis of SHS is based on clinical criteria. Mutation analysis is useful to distinguish SHS from arthrogryposis syndromes with similar features (e.g. distal arthrogryposis 1 and Freeman-Sheldon syndrome. Prenatal diagnosis by ultrasonography is feasible at 18–24 weeks of gestation. If the family history is positive and the mutation is known in the family, prenatal molecular genetic diagnosis is possible. There is no specific therapy for SHS. However, patients benefit from early intervention with occupational and physical therapy, serial casting, and/or surgery. Life expectancy and cognitive abilities are normal.
Anode sheath in Hall thrusters
International Nuclear Information System (INIS)
Dorf, L.; Semenov, V.; Raitses, Y.
2003-01-01
A set of hydrodynamic equations is used to describe quasineutral plasma in ionization and acceleration regions of a Hall thruster. The electron distribution function and Poisson equation are invoked for description of a near-anode region. Numerical solutions suggest that steady-state operation of a Hall thruster can be achieved at different anode sheath regimes. It is shown that the anode sheath depends on the thruster operating conditions, namely the discharge voltage and the mass flow rate
Chudnovsky, Eugene M.
2007-01-01
An extension of Drude model is proposed that accounts for spin and spin-orbit interaction of charge carriers. Spin currents appear due to combined action of the external electric field, crystal field and scattering of charge carriers. The expression for spin Hall conductivity is derived for metals and semiconductors that is independent of the scattering mechanism. In cubic metals, spin Hall conductivity $\\sigma_s$ and charge conductivity $\\sigma_c$ are related through $\\sigma_s = [2 \\pi \\hbar...
Optimization of Cylindrical Hall Thrusters
International Nuclear Information System (INIS)
Raitses, Yevgeny; Smirnov, Artem; Granstedt, Erik; Fisch, Nathaniel J.
2007-01-01
The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation.
Optimization of Cylindrical Hall Thrusters
International Nuclear Information System (INIS)
Raitses, Yevgeny; Smirnov, Artem; Granstedt, Erik; Fi, Nathaniel J.
2007-01-01
The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation
Hartley, R. J.; Booth, Helen
2006-01-01
Union catalogues have had an important place in libraries for many years. Their use has been little investigated. Recent interest in the relative merits of physical and virtual union catalogues and a recent collaborative project between a physical and several virtual union catalogues in the United Kingdom led to the opportunity to study how users…
Not your grandfather's concert hall
Cooper, Russell; Malenka, Richard; Griffith, Charles; Friedlander, Steven
2004-05-01
The opening of Judy and Arthur Zankel Hall on 12 September 2003, restores Andrew Carnegie's original 1891 concept of having three outstanding auditoriums of different sizes under one roof, and creates a 21st-century venue for music performance and education. With concerts ranging from early music to avant-garde multimedia productions, from jazz to world music, and from solo recitals to chamber music, Zankel Hall expands the breadth and depth of Carnegie Hall's offerings. It allows for the integration of programming across three halls with minifestivals tailored both to the size and strengths of each hall and to the artists and music to be performed. The new flexible space also provides Carnegie Hall with an education center equipped with advanced communications technology. This paper discusses the unique program planned for this facility and how the architects, theatre consultants, and acousticians developed a design that fulfilled the client's expectations and coordinated the construction of the facility under the floor of the main Isaac Stern Auditorium without having to cancel a single performance.
Schneier, Lisa
2018-01-01
Originally written 30 years ago, this paper is an analysis of the central challenge of schooling--that of engaging fully the powers of students' minds in classroom learning. This challenge maintains its relevance today. The work of engaging what John Dewey referred to as students' "inner attention" becomes the focus of an investigation…
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).
International Nuclear Information System (INIS)
Entin-Wohlman, O.
2005-01-01
Full Text:The spin-Hall effect is described. The Rashba and Dresselhaus spin-orbit interactions are both shown to yield the low temperature spin-Hall effect for strongly localized electrons coupled to phonons. A frequency-dependent electric field E(ω) generates a spin-polarization current, normal to E, due to interference of hopping paths. At zero temperature the corresponding spin-Hall conductivity is real and is proportional to ω 2 . At non-zero temperatures the coupling to the phonons yields an imaginary term proportional to ω. The interference also yields persistent spin currents at thermal equilibrium, at E = 0. The contributions from the Dresselhaus and Rashba interactions to the interference oppose each other
DEFF Research Database (Denmark)
Ibsen, Christian Lyhne; Tapia, Maite
2017-01-01
In this article, we review and assess research on the role of trade unions in labour markets and society, the current decline of unions and union revitalisation. The review shows three main trends. First, trade unions are converging into similar strategies of revitalisation. The ‘organising model...... their traditional strongholds of collective bargaining and corporatist policy-making. Second, research has shown that used strategies are not a panacea for success for unions in countries that pearheaded revitalisation. This finding points to the importance of supportive institutional frameworks if unions...... in adverse institutional contexts, can be effective when they reinvent their repertoires of contention, through political action or campaigning along global value chains....
Residencia hall del Obispado, en Gescher, Alemania
Directory of Open Access Journals (Sweden)
Deilmann, Harald
1969-02-01
Full Text Available This Hall has four lecture rooms, each with a capacity for twenty students. They all face north, have lateral and cenithal illumination and cross ventilation. The workshop training halls face south, and there is a gymnasium. Each classroom is also connected with a protected open air space, so that in suitable weather, teaching can be practised out of doors. As the school is devoted to mentally retarded boys and youths, over 2 m2 of floor area has been allowed for each student in the classrooms, since it was estimated that many students would be of the nervous type and would need more room to work freely. Most of the construction is made with unfaced brick and concrete, which are long lasting materials, requiring little maintenance.Comprende cuatro clases propiamente dichas, con una capacidad total de 80 alumnos, a razón de 20 por cada clase, y orientadas al norte, con iluminación cenital y lateral y ventilación cruzada. Los locales donde se imparten las enseñanzas de taller tienen orientación sur. Se ha previsto, además, un gimnasio. Cada clase dispone de un recinto protegido para que, cuando las condiciones atmosféricas lo permitan, se pueda desarrollar en él la enseñanza al aire libre. Como la escuela está destinada a niños y adolescentes retrasados mentales, se partió de un espacio superior a los 2 m2 por alumno, pensando en que parte de ellos iban a ser niños nerviosos y, como consecuencia, la necesidad que tendrían de amplitud suficiente para desenvolverse adecuadamente. La construcción se ha desarrollado, en general, a base de fábrica de ladrillo a cara vista y hormigón visto, materiales de gran duración y prácticamente exentos de entretenimiento.
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.
Universal intrinsic spin Hall effect
Czech Academy of Sciences Publication Activity Database
Sinova, J.; Culcer, D.; Sinitsyn, N. A.; Niu, Q.; Jungwirth, Tomáš; MacDonald, A. H.
2004-01-01
Roč. 92, č. 12 (2004), 126603/1-126603/4 ISSN 0031-9007 R&D Projects: GA ČR GA202/02/0912 Institutional research plan: CEZ:AV0Z1010914 Keywords : semiconductor quantum wells * spin-orbit interaction * spin Hall effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.218, year: 2004
International Nuclear Information System (INIS)
Dhar, S.; Basu, B.; Ghosh, Subir
2007-01-01
We explain the intrinsic spin Hall effect from generic anyon dynamics in the presence of external electromagnetic field. The free anyon is represented as a spinning particle with an underlying non-commutative configuration space. The Berry curvature plays a major role in the analysis
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…
BANKING UNION - ROMANIAN PERSPECTIVE
Directory of Open Access Journals (Sweden)
Coroiu Sorina Ioana
2015-07-01
Full Text Available The financial crisis showed that banks were not able to face the loss, because there is no framework for a resolution, so that it intervened with money from taxpayers. So, it has been highlighted the need to update the regulations applicable to the banking sector. Creating a single supervisory mechanism in the fall of 2014 was a time reference point to achieve a banking union in Europe. Banking Union is one of the four foundations for a genuine Economic and Monetary Union. The paper’s purpose is to analyze the Banking Union structure, based on three pillars: (i The Single Supervisory Mechanism - the transfer of the main responsibility regarding banking supervision from national to European level, (ii The Single Resolution Mechanism - introduction of common provisions to ensure legal support required to manage bank failures problem, (iii The Deposit Guarantee Schemes - harmonization of deposit guarantee rules. These measures were adopted at European Union level to ensure the stability of the European banking system and to prevent future crises. Because countries that are not part of the euro area are not required to join the Banking Union, the dilemma of these countries lies in the decision to join the Banking Union quickly or to wait. It is the case of Romania, also, so, this paper analyze the opportunity of Romania's accession to the Banking Union before adopting the euro. There are analyzed the advantages and disadvantages of Romania's participation in the Banking Union, showing that, in the context of single currency introduction, Romania's participation is required. So far, there are reduced debates regarding the need, advantages and disadvantages of Romania's participation in the European Banking Union, the top representatives of the National Bank of Romania being among the few who expressed their views in public and published papers on the subject.
McCarty, Shane M.; Mullins, Taris G.; Geller, E. Scott; Shushok, Frank, Jr.
2013-01-01
A professor and a group of student leaders initiated the Actively Caring for People (AC4P) Movement to establish a more civil, compassionate, and inclusive culture by inspiring intentional acts of kindness. This article explores the AC4P Movement in a first-year residence hall at Virginia Tech and a second-year residence hall at University of…
Hall effect in noncommutative coordinates
International Nuclear Information System (INIS)
Dayi, Oemer F.; Jellal, Ahmed
2002-01-01
We consider electrons in uniform external magnetic and electric fields which move on a plane whose coordinates are noncommuting. Spectrum and eigenfunctions of the related Hamiltonian are obtained. We derive the electric current whose expectation value gives the Hall effect in terms of an effective magnetic field. We present a receipt to find the action which can be utilized in path integrals for noncommuting coordinates. In terms of this action we calculate the related Aharonov-Bohm phase and show that it also yields the same effective magnetic field. When magnetic field is strong enough this phase becomes independent of magnetic field. Measurement of it may give some hints on spatial noncommutativity. The noncommutativity parameter θ can be tuned such that electrons moving in noncommutative coordinates are interpreted as either leading to the fractional quantum Hall effect or composite fermions in the usual coordinates
General vibration monitoring: Experimental hall
International Nuclear Information System (INIS)
Jendrzejczyk, J.A.; Wambsganss, M.W.; Smith, R.K.
1993-01-01
The reported vibration data were generated from measurements made on the experimental hall floor on December 2, 1992. At the time of the measurements, the ESRF hydrolevel was set-up in the Early Assembly Area (EAA) of the experimental hall and was being used to measure static displacement (settlement) of the floor. The vibration measurement area was on and adjacent to the EAA, in the vicinity of the ESRF hydrolevel test which was in progress. This report summarizes the objectives, instrumentation, measurement locations, observations, and conclusions, and provides selected results in the form of RMS vs. time plots, and power spectral densities from which frequency information can be derived. Measured response amplitudes were within the vibration criteria established for the APS
Looker, Gerard
2015-01-01
This thesis considers the role of union full time officers in union organising strategies. Two decades of promoting union organising influenced by models developed by the AFL-CIO, has failed to arrest the decline of UK trade unions let alone produce evidence of renewal. Focusing mainly on one region in the UKs largest public sector trade union, Unison, the research provides for a detailed account of how organising strategies affect union work, presenting thick and deep data from full time off...
Scanning vector Hall probe microscope
Czech Academy of Sciences Publication Activity Database
Fedor, J.; Cambel, V.; Gregušová, D.; Hanzelka, Pavel; Dérer, J.; Volko, J.
2003-01-01
Roč. 74, č. 12 (2003), s. 5105 - 5110 ISSN 0034-6748 Institutional research plan: CEZ:AV0Z2065902 Keywords : VHPM * Hall sensor * Helium cryostat Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.343, year: 2003 http://web. ebscohost .com/ehost/pdf?vid=8&hid=115&sid=a7c0555a-21f4-4932-b1c6-a308ac4dd50b%40sessionmgr2
Samson, Thomas
Nous proposons une methode permettant d'obtenir une expression pour la conductivite de Hall de structures electroniques bidimensionnelles et nous examinons celle -ci a la limite d'une temperature nulle dans le but de verifier l'effet Hall quantique. Nous allons nous interesser essentiellement a l'effet Hall quantique entier et aux effets fractionnaires inferieurs a un. Le systeme considere est forme d'un gaz d'electrons en interaction faible avec les impuretes de l'echantillon. Le modele du gaz d'electrons consiste en un gaz bidimensionnel d'electrons sans spin expose perpendiculairement a un champ magnetique uniforme. Ce dernier est decrit par le potentiel vecteur vec{rm A} defini dans la jauge de Dingle ou jauge symetrique. Conformement au formalisme de la seconde quantification, l'hamiltonien de ce gaz est represente dans la base des etats a un-corps de Dingle |n,m> et exprime ainsi en terme des operateurs de creation et d'annihilation correspondants a_sp{ rm n m}{dag} et a _{rm n m}. Nous supposons de plus que les electrons du niveau fondamental de Dingle interagissent entre eux via le potentiel coulombien. La methode utilisee fait appel a une equation mai tresse a N-corps, de nature quantique et statistique, et verifiant le second principe de la thermodynamique. A partir de celle-ci, nous obtenons un systeme d'equations differentielles appele hierarchie d'equations quantique dont la resolution nous permet de determiner une equation a un-corps, dite de Boltzmann quantique, et dictant l'evolution de la moyenne statistique de l'operateur non-diagonal a _sp{rm n m}{dag } a_{rm n}, _{rm m}, sous l'action du champ electrique applique vec{rm E}(t). C'est sa solution Tr(p(t) a _sp{rm n m}{dag} a_{rm n},_ {rm m}), qui definit la relation de convolution entre la densite courant de Hall vec{rm J}_{rm H }(t) et le champ electrique vec {rm E}(t) dont la transformee de Laplace-Fourier du noyau nous fournit l'expression de la conductivite de Hall desiree. Pour une valeur de
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.
Tunneling Anomalous and Spin Hall Effects.
Matos-Abiague, A; Fabian, J
2015-07-31
We predict, theoretically, the existence of the anomalous Hall effect when a tunneling current flows through a tunnel junction in which only one of the electrodes is magnetic. The interfacial spin-orbit coupling present in the barrier region induces a spin-dependent momentum filtering in the directions perpendicular to the tunneling current, resulting in a skew tunneling even in the absence of impurities. This produces an anomalous Hall conductance and spin Hall currents in the nonmagnetic electrode when a bias voltage is applied across the tunneling heterojunction. If the barrier is composed of a noncentrosymmetric material, the anomalous Hall conductance and spin Hall currents become anisotropic with respect to both the magnetization and crystallographic directions, allowing us to separate this interfacial phenomenon from the bulk anomalous and spin Hall contributions. The proposed effect should be useful for proving and quantifying the interfacial spin-orbit fields in metallic and metal-semiconductor systems.
The contribution of teacher unions in the restoration of teacher ...
African Journals Online (AJOL)
lynette
privileged colleagues, and can be implemented in higher education by the use of long-term, .... role of the teachers unions in the improvement teacher motivation and ...... graphic profile of students, the article reports on the service levels that.
Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator
Energy Technology Data Exchange (ETDEWEB)
Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu
2015-09-16
We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.
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.
Temperature Gradient in Hall Thrusters
International Nuclear Information System (INIS)
Staack, D.; Raitses, Y.; Fisch, N.J.
2003-01-01
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
Union banking a step towards achieving fiscal Union in the European Union
Directory of Open Access Journals (Sweden)
Ionuţ Marius Croitoru
2015-05-01
Full Text Available Introduction: Union policy needs in addition to the official language of four major components: a monetary union, a fiscal union, a union diplomatic and military union A stage in the Union is the Union banking tax. Materials and Methods: Union Bank has three pillars: a single banking supervisor (single supervisory mechanism, the only mechanism of bank resolution and a single scheme of bank guarantees. Results and conclusions: Union Bank, strengthen supervision is an inevitable process, and Romania will have to enroll in it. Option Romania is to be part of Romania deaorece bank Union can not remain outside the structures of decision as long as banks operating in Romania are predominantly Eurozone.
Schrank, R
1979-01-01
The labor movement in the United States has its roots deep in the soil of worker discontent over grueling working conditions, low pay, and indifference of bosses, who profited from others' sweaty labor. As more and more grubby jobs are replaced by technological innovations, as work becomes more abstract and everyone wears a white shirt, and as managers schooled in motivation theory and humane ideals of participation replace the owner-bosses of yesterday, what role will the unions have left to play? The author of this article, who has been in both the labor force and management, explores what the changes in the labor market will be in the future and what these changes will mean for labor-management relations. He does not conclude that there is no role for unions-only that it will be very different and that to survive unions will have to tackle new issues in the workplace. That adaptation will affect management's stance as well.
2010-02-19
... Rita C. Hall; Notice of Application Accepted for Filing With the Commision, Soliciting Motions To.... Project No.: 13652-000. c. Date filed: January 11, 2010. d. Applicant: Gary E. Hall and Rita C. Hall. e... Policies Act of 1978, 16 U.S.C. 2705, 2708. h. Applicant Contact: Mr. Gary E. Hall and Ms. Rita C. Hall, P...
DEFF Research Database (Denmark)
Manners, Ian James
2013-01-01
The past 20 years, since the 1992 Treaty on European Union, have seen the gradual creation of both an “Area of Freedom, Security and Justice” and a “Common Foreign and Security Policy”. More recent is the development of a “European Neighbourhood Policy” over the past 10 years. All three...... of these policies involved the navigation and negotiation of security, borders and governance in and by the European Union (EU). This article analyses these practices of bordering and governance through a five-fold security framework. The article argues that a richer understanding of EU security discourses can...
Nondestructive hall coefficient measurements using ACPD techniques
Velicheti, Dheeraj; Nagy, Peter B.; Hassan, Waled
2018-04-01
Hall coefficient measurements offer great opportunities as well as major challenges for nondestructive materials characterization. The Hall effect is produced by the magnetic Lorentz force acting on moving charge carriers in the presence of an applied magnetic field. The magnetic perturbation gives rise to a Hall current that is normal to the conduction current but does not directly perturb the electric potential distribution. Therefore, Hall coefficient measurements usually exploit the so-called transverse galvanomagnetic potential drop effect that arises when the Hall current is intercepted by the boundaries of the specimen and thereby produce a measurable potential drop. In contrast, no Hall potential is produced in a large plate in the presence of a uniform normal field at quasi-static low frequencies. In other words, conventional Hall coefficient measurements are inherently destructive since they require cutting the material under tests. This study investigated the feasibility of using alternating current potential drop (ACPD) techniques for nondestructive Hall coefficient measurements in plates. Specifically, the directional four-point square-electrode configuration is investigated with superimposed external magnetic field. Two methods are suggested to make Hall coefficient measurements in large plates without destructive machining. At low frequencies, constraining the bias magnetic field can replace constraining the dimensions of the specimen, which is inherently destructive. For example, when a cylindrical permanent magnet is used to provide the bias magnetic field, the peak Hall voltage is produced when the diameter of the magnet is equal to the diagonal of the square ACPD probe. Although this method is less effective than cutting the specimen to a finite size, the loss of sensitivity is less than one order of magnitude even at very low frequencies. In contrast, at sufficiently high inspection frequencies the magnetic field of the Hall current induces a
Hall magnetohydrodynamics of neutral layers
International Nuclear Information System (INIS)
Huba, J.D.; Rudakov, L.I.
2003-01-01
New analytical and numerical results of the dynamics of inhomogeneous, reversed field current layers in the Hall limit (i.e., characteristic length scales < or approx. the ion inertial length) are presented. Specifically, the two- and three-dimensional evolution of a current layer that supports a reversed field plasma configuration and has a density gradient along the current direction is studied. The two-dimensional study demonstrates that a density inhomogeneity along the current direction can dramatically redistribute the magnetic field and plasma via magnetic shock-like or rarefaction waves. The relative direction between the density gradient and current flow plays a critical role in the evolution of the current sheet. One important result is that the current sheet can become very thin rapidly when the density gradient is directed opposite to the current. The three-dimensional study uses the same plasma and field configuration as the two-dimensional study but is also initialized with a magnetic field perturbation localized along the current channel upstream of the plasma inhomogeneity. The perturbation induces a magnetic wave structure that propagates in the direction of the electron drift (i.e., opposite to the current). The propagating wave structure is a Hall phenomenon associated with magnetic field curvature. The interaction between the propagating wave structure and the evolving current layer can lead to rapid magnetic field line reconnection. The results are applied to laboratory and space plasma processes
McCarthy, Linda; Sziarto, Kristin
2015-01-01
This paper reports on an introductory world regional geography course with a role-playing exercise. The goal was to situate students in a form of popular geopolitics that engaged them viscerally with positionality and othering. Students were assigned different positionalities in a liminal active learning environment within a context of fear of…
Coke, Lileth Althea
2013-01-01
Purpose of the Study. Support programs have been known to be very effective in helping students succeed academically, socially, behaviorally, and emotionally. The purpose of this study was to investigate teachers' perceptions of the availability and need of a support program for students with learning difficulties who attend elementary schools…
Trade Union Channels for Influencing European Union Policies
Directory of Open Access Journals (Sweden)
Bengt Larsson
2015-10-01
Full Text Available This paper analyzes what channels trade unions in Europe use when trying to influence European Union (EU policies. It compares and contrasts trade unions in different industrial relations regimes with regard to the degree to which they cooperate with different actors to influence EU policies, while also touching on the importance of sector differences and organizational resources. The study is based on survey data collected in 2010–2011 from unions affiliated with the European Trade Union Confederation and from below peak unions in 14 European countries. Results of the survey show that the ‘national route’ is generally the most important for trade unions in influencing EU policies in the sense that this channel is, on average, used to the highest degree. In addition, the survey delineates some important differences between trade unions in different industrial relations regimes with regard to the balance between the national route and different access points in the ‘Brussels route’.
Quantum Hall effect in quantum electrodynamics
International Nuclear Information System (INIS)
Penin, Alexander A.
2009-01-01
We consider the quantum Hall effect in quantum electrodynamics and find a deviation from the quantum-mechanical prediction for the Hall conductivity due to radiative antiscreening of electric charge in an external magnetic field. A weak dependence of the universal von Klitzing constant on the magnetic field strength, which can possibly be observed in a dedicated experiment, is predicted
Hall devices improve electric motor efficiency
Haeussermann, W.
1979-01-01
Efficiency of electric motors and generators is reduced by radial magnetic forces created by symmetric fields within device. Forces are sensed and counteracted by Hall devices on excitation or control windings. Hall generators directly measure and provide compensating control of anu asymmetry, eliminating additional measurements needed for calibration feedback control loop.
Higher fractions theory of fractional hall effect
International Nuclear Information System (INIS)
Kostadinov, I.Z.; Popov, V.N.
1985-07-01
A theory of fractional quantum Hall effect is generalized to higher fractions. N-particle model interaction is used and the gap is expressed through n-particles wave function. The excitation spectrum in general and the mean field critical behaviour are determined. The Hall conductivity is calculated from first principles. (author)
Dynamics Of Human Motion The Case Study of an Examination Hall
Ogunjo, Samuel; Ajayi, Oluwaseyi; Fuwape, Ibiyinka; Dansu, Emmanuel
Human behaviour is difficult to characterize and generalize due to ITS complex nature. Advances in mathematical models have enabled human systems such as love interaction, alcohol abuse, admission problem to be described using models. This study investigates one of such problems, the dynamics of human motion in an examination hall with limited computer systems such that students write their examination in batches. The examination is characterized by time (t) allocated to each students and difficulty level (dl) associated with the examination. A stochastic model based on the difficulty level of the examination was developed for the prediction of student's motion around the examination hall. A good agreement was obtained between theoretical predictions and numerical simulation. The result obtained will help in better planning of examination session to maximize available resources. Furthermore, results obtained in the research can be extended to other areas such as banking hall, customer service points where available resources will be shared amongst many users.
Geber, Beverly
1987-01-01
The author discusses the concept, first encouraged by Irving Bluestone of the United Auto Workers, that union and management personnel should work together to achieve company goals. The history of this cooperative effort movement within the United Auto Workers is described. (CH)
Perspectives and expectations of union member and non- union member teachers on teacher unions
Directory of Open Access Journals (Sweden)
Tuncer FİDAN
2015-12-01
Full Text Available Unions, which can be regarded as one of the constitutive elements of democracy, are the pressure groups in political and social fields. Unions were born out of industrial confrontations and expanded into the field of public services over time, and thus teachers – who are also public employees-, also obtained the right to establish and affiliate to unions. In this research the views of union member and non-union member teachers on the most important functions and operational effectiveness of unions, teachers’ expectations from unions and teachers’ evaluation of the solidarity, competition and cooperation between unions were determined and the perspectives of teachers on unionization were revealed. qualitative research design was used. The data needed were collected through semi-structured interviews from volunteering union member and non-union member teachers who were working in the primary and secondary schools in Ankara province and who were selected through “maximum variation sampling approach”. The data were then analyzed by using the content analysis technique. In conclusion, it was found that political ideology was the most important reason for membership of teachers’ unions. Protection and development of personal rights was found to be the most important function of teacher unions and unions were thought to be insufficient in performing those functions.
Report of experimental hall subworking group
International Nuclear Information System (INIS)
Miyake, K.; Ohama, T.; Takahashi, K.
1982-01-01
The general plan of constructing the TRISTAN e + e - colliding beam experimental halls may be divided into two parts. The first step is to construct two test-experimental halls associated with the 6.5 GeV x 6.5 GeV e + e - accumulator ring, and the second step is to build four experimental halls at the 30 GeV x 30 GeV e + e - TRISTAN main ring. At this workshop, extensive discussions on the detailed design of the four main ring experimental halls have been made. Four experimental areas will be built at the main ring, and two test-experimental halls at the accumulating ring. Among the four areas at the main ring, two will be used for electron-proton possible as well as electron-positron colliding beam experiment. The other two will be used exclusively for e + e - colliding experiments. Only a preliminary design has been made for these four experimental areas. A tentative plan of a larger experimental hall includes a counting and data processing room, a utility room, and a radiation safety control room. Two smaller halls have simpler structure. The figures of the experimental halls are presented. The two test-experimental halls at the accumulator ring will be used to test the detectors for e + e - colliding experiments before the final installation. The utility rooms designed for the halls are used to supply coolant and electric power of superconducting magnets. At the workshop, various ideas concerning the preliminary plan are presented. (Kato, T.)
The Development of Trade Unionism.
Parker, Ronald W.
1979-01-01
Traces the growth and evolution of the British labor union movement, troubles between the national officials and the local shop stewards, class differences and conflict between the artisans and laborers, violence between unions, and eventual transition to peaceful constitutionalism. (MF)
The quantum Hall effect helicity
Energy Technology Data Exchange (ETDEWEB)
Shrivastava, Keshav N., E-mail: keshav1001@yahoo.com [Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia); School of Physics, University of Hyderabad, Hyderabad 500046 (India)
2015-04-16
The quantum Hall effect in semiconductor heterostructures is explained by two signs in the angular momentum j=l±s and g=(2j+1)/(2l+1) along with the Landau factor (n+1/2). These modifications in the existing theories explain all of the fractional charges. The helicity which is the sign of the product of the linear momentum with the spin p.s plays an important role for the understanding of the data at high magnetic fields. In particular it is found that particles with positive sign in the spin move in one direction and those with negative sign move in another direction which explains the up and down stream motion of the particles.
Stuart Hall: An Organic Intellectual
Directory of Open Access Journals (Sweden)
Johanna Fernández Castro
2017-01-01
Full Text Available Stuart Hall (3 February 1932 – 10 February 2014 is acknowledged as one of the founding figures of British Cultural Studies. His extensive academic work on topics such as race, ethnicity and identity reflects his own position as a diasporic intellectual. His contribution to the study of popular culture is determined by the importance of his political character in every social act, his non-deterministic view of Marxism, and is especially determined by his insistence on playing an active role beyond academia in order to contribute to the transformation of hegemonic structures. The following biography aims to give a focused view of his personal history and its direct influence on his key theoretical reflections.
The fractional quantum Hall effect
International Nuclear Information System (INIS)
Stormer, H.L.
1988-01-01
The fractional quantum Hall effect (FQHE), is the manifestation of a new, highly correlated, many-particle ground state that forms in a two-dimensional electron system at low temperatures and in high magnetic fields. It is an example of the new physics that has grown out of the tremendous recent advances in semiconductor material science, which has provided us with high-quality, lower-dimensional carrier systems. The novel electronic state exposes itself in transport experiments through quantization of the Hall resistance to an exact rational fraction of h/e, and concomitantly vanishing longitudinal resistivity. Its relevant energy scale is only a few degrees kelvin. The quantization is a consequence of the spontaneous formation of an energy gap separating the condensed ground state from its rather elusive quasiparticle excitations. The theoretical understanding of the novel quantum liquids which underlie the FQHE has predominantly emerged from an ingenious many-particle wave function strongly supported by numerous few-particle simulations. Theory has now constructed a complex model for ideal two-dimensional electron systems in the presence of high magnetic fields and makes definitive, often fascinating predictions. Experiments have successively uncovered odd-denominator fractional states reaching presently to 7/13. The application of new experimental tools to the FQHE, such as optics, microwaves, and phonon techniques promises the direct observation of such parameters as the gap energy and possibly even some of the more elusive quantities in the future. While theory and experiment in the FQHE appear to be converging, there remains considerable room for challenging surprises. This paper provides a concise overview of the FQHE. It focuses on the experimental aspects and states, but does not expand on the theoretical advances. 70 refs., 11 figs
Union Directions - Army Response.
1985-12-06
reflects the long-held belief in the Army that employee participation in decisions that affect their worklife is healthy and desirable. Although some...pluralistic society, checks and balances are as important for the economy as for the government. Business executives who salivate at the thought of vanishing...Unions. Reading, MA: Addison-Wesley, 1976. 37. National Federation of Federal Employees. NFFE’s Guide to Quality of Worklife Programs. No. G-21
European Union Budget Politics
DEFF Research Database (Denmark)
Citi, Manuele
2015-01-01
The marginal involvement of the European Union (EU) in redistributive policies and its limited fiscal resources have led to a notable lack of attention by EU scholars towards the EU budget and its dynamics. Yet the nature of the budgetary data and their high usability for statistical analysis make...... to form winning coalitions in the Council, the ideological positioning of the co-legislators and the inclusion of the cohesion countries have played a significant role in driving budget change....
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.
Quantized Hall conductance as a topological invariant
International Nuclear Information System (INIS)
Niu, Q.; Thouless, Ds.J.; Wu, Y.S.
1984-10-01
Whenever the Fermi level lies in a gap (or mobility gap) the bulk Hall conductance can be expressed in a topologically invariant form showing the quantization explicitly. The new formulation generalizes the earlier result by TKNN to the situation where many body interaction and substrate disorder are also present. When applying to the fractional quantized Hall effect we draw the conclusion that there must be a symmetry breaking in the many body ground state. The possibility of writing the fractionally quantized Hall conductance as a topological invariant is also carefully discussed. 19 references
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.
Anderson, Scott; Raasch, Kevin
2002-01-01
Provides an evaluation template for student activities professionals charged with evaluating competitive event scheduling software. Guides staff in making an informed decision on whether to retain event management technology provided through an existing vendor or choose "best-of-breed" scheduling software. (EV)
Contribution of the study of the Hall Effect. Hall Effect of powder products
International Nuclear Information System (INIS)
Cherville, Jean
1961-01-01
This research thesis reports the development of an apparatus aimed at measuring the Hall Effect and the magneto-resistance of powders at room temperature and at the liquid nitrogen temperature. The author also proposes a theoretical contribution to the Hall Effect and reports the calculation of conditions to be met to obtain a correct value for the Hall constant. Results are experimentally verified. The method is then applied to the study of a set of powdered pre-graphitic graphites. The author shows that their Hall coefficient confirms the model already proposed by Mrozowski. The study of the Hall Effect of any kind of powders can thus be performed, and the Hall Effect can therefore be a mean to study mineral and organic compounds, and notably powdered biological molecules [fr
The infrared Hall effect in YBCO: Temperature and frequency dependence of Hall scattering
International Nuclear Information System (INIS)
Grayson, M.; Cerne, J.; Drew, H.D.; Schmadel, D.C.; Hughes, R.; Preston, J.S.; Kung, P.J.; Vale, L.
1999-01-01
The authors measure the Hall angle, θ H , in YBCO films in the far- and mid-infrared to determine the temperature and frequency dependence of the Hall scattering. Using novel modulation techniques they measure both the Faraday rotation and ellipticity induced by these films in high magnetic fields to deduce the complex conductivity tensor. They observe a strong temperature dependence of the mid-infrared Hall conductivity in sharp contrast to the weak dependence of the longitudinal conductivity. By fitting the frequency dependent normal state Hall angle to a Lorentzian θ H (ω) = ω H /(γ H minus iω) they find the Hall frequency, ω H , is nearly independent of temperature. The Hall scattering rate, γ H , is consistent with γ H ∼ T 2 up to 200 K and is remarkably independent of IR frequency suggesting non-Fermi liquid behavior
Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2
Firoz Islam, SK; Benjamin, Colin
2016-09-01
The quantum magnetotransport properties of a monolayer of molybdenum disulfide are derived using linear response theory. In particular, the effect of topological terms on longitudinal and Hall conductivity is analyzed. The Hall conductivity exhibits fractional steps in the integer quantum Hall regime. Further complete spin and valley polarization of the longitudinal conductivitity is seen in presence of these topological terms. Finally, the Shubnikov-de Hass oscillations are suppressed or enhanced contingent on the sign of these topological terms.
Spin Hall effect by surface roughness
Zhou, Lingjun; Grigoryan, Vahram L.; Maekawa, Sadamichi; Wang, Xuhui; Xiao, Jiang
2015-01-01
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.
Mesoscopic effects in the quantum Hall regime
Indian Academy of Sciences (India)
. 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 ...
Plasmon Geometric Phase and Plasmon Hall Shift
Shi, Li-kun; Song, Justin C. W.
2018-04-01
The collective plasmonic modes of a metal comprise a simple pattern of oscillating charge density that yields enhanced light-matter interaction. Here we unveil that beneath this familiar facade plasmons possess a hidden internal structure that fundamentally alters its dynamics. In particular, we find that metals with nonzero Hall conductivity host plasmons with an intricate current density configuration that sharply departs from that of ordinary zero Hall conductivity metals. This nontrivial internal structure dramatically enriches the dynamics of plasmon propagation, enabling plasmon wave packets to acquire geometric phases as they scatter. At boundaries, these phases accumulate allowing plasmon waves that reflect off to experience a nonreciprocal parallel shift. This plasmon Hall shift, tunable by Hall conductivity as well as plasmon wavelength, displaces the incident and reflected plasmon trajectories and can be readily probed by near-field photonics techniques. Anomalous plasmon geometric phases dramatically enrich the nanophotonics toolbox, and yield radical new means for directing plasmonic beams.
A system for pulse Hall effect measurements
International Nuclear Information System (INIS)
Orzechowski, T.; Kupczak, R.
1975-01-01
Measuring system for fast Hall-voltage changes in an n-type germanium sample irradiated at liquid nitrogen temperature with a high-energy electron-beam from the Van de Graaff accelerator is described. (author)
Novel optical probe for quantum Hall system
Indian Academy of Sciences (India)
to explore Landau levels of a two-dimensional electron gas (2DEG) in modulation doped ... Keywords. Surface photovoltage spectroscopy; quantum Hall effect; Landau levels; edge states. ... An optical fibre carries light from tunable diode laser.
AA under construction in its hall
CERN PhotoLab
1980-01-01
The Antiproton Accumulator was installed in a specially built hall. Here we see it at an "early" stage of installation, just a few magnets on the floor, no vacuum chamber at all, but: 3 months later there was circulating beam !
Elementary theory of quantum Hall effect
Directory of Open Access Journals (Sweden)
Keshav N. Shrivastava
2008-04-01
Full Text Available The Hall effect is the generation of a current perpendicular to both the direction of the applied electric as well as magnetic field in a metal or in a semiconductor. It is used to determine the concentration of electrons. The quantum Hall effect with integer quantization was discovered by von Klitzing and fractionally charged states were found by Tsui, Stormer and Gossard. Robert Laughlin explained the quantization of Hall current by using “flux quantization” and introduced incompressibility to obtain the fractional charge. We have developed the theory of the quantum Hall effect by using the theory of angular momentum. Our predicted fractions are in accord with those measured. We emphasize our explanation of the observed phenomena. We use spin to explain the fractional charge and hence we discover spin-charge locking.
The fluctuation Hall conductivity and the Hall angle in type-II superconductor under magnetic field
Energy Technology Data Exchange (ETDEWEB)
Tinh, Bui Duc, E-mail: tinhbd@hnue.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Hoc, Nguyen Quang; Thu, Le Minh [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)
2016-02-15
Highlights: • The time-dependent Ginzburg–Landau was used to calculate fluctuation Hall conductivity and Hall angle in type-II superconductor in 2D and 3D. • We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. • The results were compared to the experimental data on YBCO. - Abstract: The fluctuation Hall conductivity and the Hall angle, describing the Hall effect, are calculated for arbitrary value of the imaginary part of the relaxation time in the frame of the time-dependent Ginzburg–Landau theory in type II-superconductor with thermal noise describing strong thermal fluctuations. The self-consistent Gaussian approximation is used to treat the nonlinear interaction term in dynamics. We obtain analytical expressions for the fluctuation Hall conductivity and the Hall angle summing all Landau levels without need to cutoff higher Landau levels to treat arbitrary magnetic field. The results are compared with experimental data on high-T{sub c} superconductor.
The National Academies of Sciences, Engineering and Medicine is seeking community input for a study on the future of materials research (MR). Frontiers of Materials Research: A Decadal Survey will look at defining the frontiers of materials research ranging from traditional materials science and engineering to condensed matter physics. Please join members of the study committee for a town hall to discuss future directions for materials research in the United States in the context of worldwide efforts. In particular, input on the following topics will be of great value: progress, achievements, and principal changes in the R&D landscape over the past decade; identification of key MR areas that have major scientific gaps or offer promising investment opportunities from 2020-2030; and the challenges that MR may face over the next decade and how those challenges might be addressed. This study was requested by the Department of Energy and the National Science Foundation. The National Academies will issue a report in 2018 that will offer guidance to federal agencies that support materials research, science policymakers, and researchers in materials research and other adjoining fields. Learn more about the study at http://nas.edu/materials.
Teacher Salaries and Teacher Unions: A Spatial Econometric Approach
John V. Winters
2011-01-01
The author uses a spatial econometric framework to examine the determinants of teacher salaries in the United States, including union activity in the teachers' own and in neighboring districts, teacher salaries in nearby districts, and other school district characteristics such as size and student-teacher ratios. Using the 1999-2000 Schools and Staffing Survey as well as the School District Demographic System and Bureau of Labor Statistics data sets, he finds that union activity increases sal...
Resistive Instabilities in Hall Current Plasma Discharge
International Nuclear Information System (INIS)
Litvak, Andrei A.; Fisch, Nathaniel J.
2000-01-01
Plasma perturbations in the acceleration channel of a Hall thruster are found to be unstable in the presence of collisions. Both electrostatic lower-hybrid waves and electromagnetic Alfven waves transverse to the applied electric and magnetic field are found to be unstable due to collisions in the E X B electron flow. These results are obtained assuming a two-fluid hydrodynamic model in slab geometry. The characteristic frequencies of these modes are consistent with experimental observations in Hall current plasma thrusters
Are tent halls subject to property tax?
Directory of Open Access Journals (Sweden)
Mariusz Macudziński
2016-12-01
Full Text Available The presented publication is a response to currently asked questions and interpretative doubts of taxpayers and tax authorities, namely whether tent halls are subject to property tax. General issues connected with an entity and a subject of taxation of this tax are presented herein. The answer to the question asked is then provided through the qualification of constructions works and the allocation of tent halls in the proper category of the works, with the use of the current law.
Fractional statistics and fractional quantized Hall effect
International Nuclear Information System (INIS)
Tao, R.; Wu, Y.S.
1985-01-01
The authors suggest that the origin of the odd-denominator rule observed in the fractional quantized Hall effect (FQHE) may lie in fractional statistics which govern quasiparticles in FQHE. A theorem concerning statistics of clusters of quasiparticles implies that fractional statistics do not allow coexistence of a large number of quasiparticles at fillings with an even denominator. Thus, no Hall plateau can be formed at these fillings, regardless of the presence of an energy gap. 15 references
Hall effect in organic layered conductors
Directory of Open Access Journals (Sweden)
R.A.Hasan
2006-01-01
Full Text Available The Hall effect in organic layered conductors with a multisheeted Fermi surfaces was considered. It is shown that the experimental study of Hall effect and magnetoresistance anisotropy at different orientations of current and a quantizing magnetic field relative to the layers makes it possible to determine the contribution of various charge carriers groups to the conductivity, and to find out the character of Fermi surface anisotropy in the plane of layers.
Recent Migrants and Education in the European Union
Osadan, Robert; Reid, Elizabeth
2016-01-01
European schools should improve their methods for teaching migrant students. The European Union has been making efforts to meet the needs of migrant students for some time. From the 2009 Eurydice report "Integrating Immigrant Children into Schools in Europe," which suggests measures to foster inclusion in the larger community and…
Malone Margaret Mary
2018-01-01
The year 2017 was eventful for the EU and its member states. Given the widespread Euroscepticism and populism which appeared to be on the rise last year, election results in the Netherlands, France and Germany were greeted with relief and hope for the future. The EU was in an optimistic mood. European Commission President Jean- Claude Juncker used his State of the European Union speech in September to note that the EU had the ‘wind in its sails’ (Juncker, 2017). At the same time, he cautioned...
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…
Prentice Hall/Pearson Literature© (2007-15). What Works Clearinghouse Intervention Report
What Works Clearinghouse, 2017
2017-01-01
"Prentice Hall/Pearson Literature©" (2007-15) is an English language arts curriculum designed for students in grades 6-12 that focuses on building reading, vocabulary, literary analysis, and writing skills. It uses passages from fiction and nonfiction texts, poetry, and contemporary digital media. The curriculum is based on a textbook.…
Raising the Bar: Standards and Tests in California's High Schools. A Town Hall Meeting.
Arnstine, Barbara; Futernick, Ken; Hodson, Timothy A.; Ostgaard, Kolleen
In 1999, the LegiSchool Project planned to conduct the 12th in its series of televised Town Hall Meetings to provide a forum in which California high school students, educators, and legislators can engage in face-to-face dialogue about problems of mutual interest. For 1999, the topic is standards and tests in California high schools. This guide…
Currency union entries and trade
Nitsch, Volker
2005-01-01
Recent research suggests that adopting a common currency increases bilateral trade. In this paper, I explore experiences of currency union entry in the post-war period and find no effect on trade. Previous results derived from a large panel data set (covering more than 200 countries from 1948 through 1997) appear to depend crucially on the assumption of symmetry between currency union exits and entries: While countries leaving a currency union experience significant declines in trade, currenc...
Official Union Time Tracking System
Social Security Administration — Official Union Time Tracking System captures the reporting and accounting of the representational activity for all American Federation of Government Employees (AFGE)...
75 FR 22770 - Gary E. Hall and Rita Hall; Notice of Availability of Environmental Assessment
2010-04-30
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13652-000-Montana] 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, and the Federal Energy Regulatory...
Charge carrier coherence and Hall effect in organic semiconductors
Yi, H. T.; Gartstein, Y. N.; Podzorov, V.
2016-01-01
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. PMID:27025354
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.
Reed, Kathlyn L
2005-01-01
Herbert James Hall, MD (1870-1923), was a pioneer in the systematic and organized study of occupation as therapy for persons with nervous and mental disorders that he called the "work cure." He began his work in 1904 during the early years of the Arts and Crafts Movement in the United States. His primary interest was the disorder neurasthenia, a condition with many symptoms including chronic fatigue, stress, and inability to work or perform everyday tasks. The prevailing treatment of the day was absolute bed rest known as the "rest cure." Hall believed that neurasthenia was not caused by overwork but by faulty living habits that could be corrected through an ordered life schedule and selected occupations. He identified several principles of therapy that are still used today including graded activity and energy conservation. Dr. Adolph Meyer credits Hall for organizing the ideas on the therapeutic use of occupation (Meyer, 1922). Hall also provided the name American Occupational Therapy Association for the professional organization and served as the fourth president. For his many contributions to the profession Hall deserves to be recognized as a major contributor to the development and organization of occupational therapy.
A new CMOS Hall angular position sensor
Energy Technology Data Exchange (ETDEWEB)
Popovic, R.S.; Drljaca, P. [Swiss Federal Inst. of Tech., Lausanne (Switzerland); Schott, C.; Racz, R. [SENTRON AG, Zug (Switzerland)
2001-06-01
The new angular position sensor consists of a combination of a permanent magnet attached to a shaft and of a two-axis magnetic sensor. The permanent magnet produces a magnetic field parallel with the magnetic sensor plane. As the shaft rotates, the magnetic field also rotates. The magnetic sensor is an integrated combination of a CMOS Hall integrated circuit and a thin ferromagnetic disk. The CMOS part of the system contains two or more conventional Hall devices positioned under the periphery of the disk. The ferromagnetic disk converts locally a magnetic field parallel with the chip surface into a field perpendicular to the chip surface. Therefore, a conventional Hall element can detect an external magnetic field parallel with the chip surface. As the direction of the external magnetic field rotates in the chip plane, the output voltage of the Hall element varies as the cosine of the rotation angle. By placing the Hall elements at the appropriate places under the disk periphery, we may obtain the cosine signals shifted by 90 , 120 , or by any other angle. (orig.)
Composite fermions in the quantum Hall effect
International Nuclear Information System (INIS)
Johnson, B.L.; Kirczenow, G.
1997-01-01
The quantum Hall effect and associated quantum transport phenomena in low-dimensional systems have been the focus of much attention for more than a decade. Recent theoretical development of interesting quasiparticles - 'composite fermions' - has led to significant advances in understanding and predicting the behaviour of two-dimensional electron systems under high transverse magnetic fields. Composite fermions may be viewed as fermions carrying attached (fictitious) magnetic flux. Here we review models of the integer and fractional quantum Hall effects, including the development of a unified picture of the integer and fractional effects based upon composite fermions. The composite fermion picture predicts remarkable new physics: the formation of a Fermi surface at high magnetic fields, and anomalous ballistic transport, thermopower, and surface acoustic wave behaviour. The specific theoretical predictions of the model, as well as the body of experimental evidence for these phenomena are reviewed. We also review recent edge-state models for magnetotransport in low-dimensional devices based on the composite fermion picture. These models explain the fractional quantum Hall effect and transport phenomena in nanoscale devices in a unified framework that also includes edge state models of the integer quantum Hall effect. The features of the composite fermion edge-state model are compared and contrasted with those of other recent edge-state models of the fractional quantum Hall effect. (author)
Air temperature gradient in large industrial hall
Karpuk, Michał; Pełech, Aleksander; Przydróżny, Edward; Walaszczyk, Juliusz; Szczęśniak, Sylwia
2017-11-01
In the rooms with dominant sensible heat load, volume airflow depends on many factors incl. pre-established temperature difference between exhaust and supply airflow. As the temperature difference is getting higher, airflow volume drops down, consequently, the cost of AHU is reduced. In high industrial halls with air exhaust grids located under the ceiling additional temperature gradient above working zone should be taken into consideration. In this regard, experimental research of the vertical air temperature gradient in high industrial halls were carried out for the case of mixing ventilation system The paper presents the results of air temperature distribution measurements in high technological hall (mechanically ventilated) under significant sensible heat load conditions. The supply airflow was delivered to the hall with the help of the swirl diffusers while exhaust grids were located under the hall ceiling. Basing on the air temperature distribution measurements performed on the seven pre-established levels, air temperature gradient in the area between 2.0 and 7.0 m above the floor was calculated and analysed.
Field theory approach to quantum hall effect
International Nuclear Information System (INIS)
Cabo, A.; Chaichian, M.
1990-07-01
The Fradkin's formulation of statistical field theory is applied to the Coulomb interacting electron gas in a magnetic field. The electrons are confined to a plane in normal 3D-space and also interact with the physical 3D-electromagnetic field. The magnetic translation group (MTG) Ward identities are derived. Using them it is shown that the exact electron propagator is diagonalized in the basis of the wave functions of the free electron in a magnetic field whenever the MTG is unbroken. The general tensor structure of the polarization operator is obtained and used to show that the Chern-Simons action always describes the Hall effect properties of the system. A general proof of the Streda formula for the Hall conductivity is presented. It follows that the coefficient of the Chern-Simons terms in the long-wavelength approximation is exactly given by this relation. Such a formula, expressing the Hall conductivity as a simple derivative, in combination with diagonal form of the full propagator allows to obtain a simple expressions for the filling factor and the Hall conductivity. Indeed, these results, after assuming that the chemical potential lies in a gap of the density of states, lead to the conclusion that the Hall conductivity is given without corrections by σ xy = νe 2 /h where ν is the filling factor. In addition it follows that the filling factor is independent of the magnetic field if the chemical potential remains in the gap. (author). 21 ref, 1 fig
Extrinsic spin Hall effect in graphene
Rappoport, Tatiana
The intrinsic spin-orbit coupling in graphene is extremely weak, making it a promising spin conductor for spintronic devices. In addition, many applications also require the generation of spin currents in graphene. Theoretical predictions and recent experimental results suggest one can engineer the spin Hall effect in graphene by greatly enhancing the spin-orbit coupling in the vicinity of an impurity. The extrinsic spin Hall effect then results from the spin-dependent skew scattering of electrons by impurities in the presence of spin-orbit interaction. This effect can be used to efficiently convert charge currents into spin-polarized currents. I will discuss recent experimental results on spin Hall effect in graphene decorated with adatoms and metallic cluster and show that a large spin Hall effect can appear due to skew scattering. While this spin-orbit coupling is small if compared with what it is found in metals, the effect is strongly enhanced in the presence of resonant scattering, giving rise to robust spin Hall angles. I will present our single impurity scattering calculations done with exact partial-wave expansions and complement the analysis with numerical results from a novel real-space implementation of the Kubo formalism for tight-binding Hamiltonians. The author acknowledges the Brazilian agencies CNPq, CAPES, FAPERJ and INCT de Nanoestruturas de Carbono for financial support.
Directory of Open Access Journals (Sweden)
Malone Margaret Mary
2018-02-01
Full Text Available The year 2017 was eventful for the EU and its member states. Given the widespread Euroscepticism and populism which appeared to be on the rise last year, election results in the Netherlands, France and Germany were greeted with relief and hope for the future. The EU was in an optimistic mood. European Commission President Jean- Claude Juncker used his State of the European Union speech in September to note that the EU had the ‘wind in its sails’ (Juncker, 2017. At the same time, he cautioned that the fair weather conditions would not last long - there was no room for complacency. The EU had to act to protect, empower and defend its citizens. The EU moved forward on a number of policy fronts in the wake of the Brexit vote and also concluded high-profile international trade deals in an effort to fill the vacuum left by the protectionist policies of the Trump administration.
Professional Employees Turn to Unions
Chamot, Dennis
1976-01-01
White-collar and professional employees are increasingly turning to unions to combat their loss of independence as employees of large organizations. Managers should realize that they and professional employees have different viewpoints about job situations and that the current trend toward white-collar unionism is apt to continue. (JG)
Is Union Job Dissatisfaction Real?
Hersch, Joni; Stone, Joe A.
1990-01-01
A comparison of data from a Eugene, Oregon, worker survey with data from the Quality of Employment Survey found that union job dissatisfaction arises from factors independent of wages and working conditions. Union perspectives of working conditions do not accurately reflect objective measures of conditions. The dissatisfaction expressed has real…
Grassmann codes and Schubert unions
DEFF Research Database (Denmark)
Hansen, Johan Peder; Johnsen, Trygve; Ranestad, Kristian
2009-01-01
We study subsets of Grassmann varieties over a field , such that these subsets are unions of Schubert cycles, with respect to a fixed flag. We study such sets in detail, and give applications to coding theory, in particular for Grassmann codes. For much is known about such Schubert unions with a ...
Science Careers and Disabled Students.
Jagoda, Sue; Cremer, Bob
1981-01-01
Summarizes proceedings and student experiences at the 1980 Science Career Workshop for Physically Disabled Students at the Lawrence Hall of Science (University of California). Includes a description of the key-note speaker's topics, and other workshop activities. (DS)
The Role of Graduate Employee Unions in Gender Equality (abstract)
Murphy, Nicholas A.; Freeland, Emily
2009-04-01
Graduate employee unions represent a significant fraction of graduate employees in the United States, Canada, and other nations. The collective bargaining process is a unique forum where issues ranging from paid parental leave, hostile work environment, and access to lactation rooms can be addressed on an even footing with the employing universities. Because employment is governed by a collective bargaining agreement, violations are subject to a grievance policy. The Teaching Assistants' Association at the University of Wisconsin-Madison is one of the oldest graduate employee unions in the world. We discuss this example union, including successes in both the collective bargaining process and the grievance procedure. In particular, we find that graduate employee unions are an effective means of fighting pregnancy discrimination. We also provide a comparison of parental leave policies for graduate students at various universities.
Localization in a quantum spin Hall system.
Onoda, Masaru; Avishai, Yshai; Nagaosa, Naoto
2007-02-16
The localization problem of electronic states in a two-dimensional quantum spin Hall system (that is, a symplectic ensemble with topological term) is studied by the transfer matrix method. The phase diagram in the plane of energy and disorder strength is exposed, and demonstrates "levitation" and "pair annihilation" of the domains of extended states analogous to that of the integer quantum Hall system. The critical exponent nu for the divergence of the localization length is estimated as nu congruent with 1.6, which is distinct from both exponents pertaining to the conventional symplectic and the unitary quantum Hall systems. Our analysis strongly suggests a different universality class related to the topology of the pertinent system.
Hall probe magnetometer for SSC magnet cables
International Nuclear Information System (INIS)
Cross, R.W.; Goldfarb, R.B.
1991-01-01
The authors of this paper constructed a Hall probe magnetometer to measure the magnetization hysteresis loops of Superconducting Super Collider magnet cables. The instrument uses two Hall-effect field sensors to measure the applied field H and the magnetic induction B. Magnetization M is calculated from the difference of the two quantities. The Hall probes are centered coaxially in the bore of a superconducting solenoid with the B probe against the sample's broad surface. An alternative probe arrangement, in which M is measured directly, aligns the sample probe parallel to the field. The authors measured M as a function of H and field cycle rate both with and without a dc transport current. Flux creep as a function of current was measured from the dependence of ac loss on the cycling rate and from the decay of magnetization with time. Transport currents up to 20% of the critical current have minimal effect on magnetization and flux creep
Spin Hall Effect in Doped Semiconductor Structures
Tse, Wang-Kong; Das Sarma, Sankar
2006-03-01
We present a microscopic theory of the extrinsic spin Hall effect based on the diagrammatic perturbation theory. Side-jump (SJ) and skew-scattering (SS) contributions are explicitly taken into account to calculate the spin Hall conductivity, and we show their effects scale as σxy^SJ/σxy^SS ˜(/τ)/ɛF, where τ being the transport relaxation time. Motivated by recent experimental work we apply our theory to n-doped and p-doped 3D and 2D GaAs structures, obtaining analytical formulas for the SJ and SS contributions. Moreover, the ratio of the spin Hall conductivity to longitudinal conductivity is found as σs/σc˜10-3-10-4, in reasonable agreement with the recent experimental results of Kato et al. [Science 306, 1910 (2004)] in n-doped 3D GaAs system.
Shielding consideration for the SSCL experimental halls
International Nuclear Information System (INIS)
Bull, J.; Coyne, J.; Mokhov, N.; Stapleton, G.
1994-03-01
The Superconducting Super Collider which is being designed and built in Waxahachie, Texas consists Of series of proton accelerators, culminating in a 20 Te proton on proton collider. The collider will be in a tunnel which will be 87 km in circumference and. on average about 30 meters underground. The present design calls for two large interaction halls on the east side of the ring. The shielding for these halls is being designed for an interaction rate of 10 9 Hz or 10 16 interactions per year, based on 10 7 seconds per operational year. SSC guidelines require that the shielding be designed to meet the criterion of 1mSv per year for open areas off site 2mSv per year for open areas on site, and 2mSv per year for controlled areas. Only radiation workers will be routinely allowed to work in controlled areas. It should be pointed that there is a potential for an accidental full beam loss in either of the experimental halls, and this event would consist of the loss of the full circulating beam up to 4 x 10 14 protons. With the present design. the calculated dose equivalent for this event is about 10% of the annual dose equivalent for the normal p-p interactions, so that die accident condition does not control the shielding. If, for instance, local shielding within the experimental hall is introduced into the calculations, this could change. The shielding requirements presented here are controlled by the normal p-p interactions. Three important questions were addressed in the present calculations. They are (1) the thickness of the roof over the experimental halls, (2) the configuration of the shafts and adits which give access to the halls, and (3) the problem of ground water and air activation
Developments in Scanning Hall Probe Microscopy
Chouinard, Taras; Chu, Ricky; David, Nigel; Broun, David
2009-05-01
Low temperature scanning Hall probe microscopy is a sensitive means of imaging magnetic structures with high spatial resolution and magnetic flux sensitivity approaching that of a Superconducting Quantum Interference Device. We have developed a scanning Hall probe microscope with novel features, including highly reliable coarse positioning, in situ optimization of sensor-sample alignment and capacitive transducers for linear, long range positioning measurement. This has been motivated by the need to reposition accurately above fabricated nanostructures such as small superconducting rings. Details of the design and performance will be presented as well as recent progress towards time-resolved measurements with sub nanosecond resolution.
Enhanced Performance of Cylindrical Hall Thrusters
International Nuclear Information System (INIS)
Raitses, Y.; Smirnov, A.; Fisch, N.J.
2007-01-01
The cylindrical thruster differs significantly in its underlying physical mechanisms from the conventional annular Hall thruster. It features high ionization efficiency, quiet operation, ion acceleration in a large volume-to-surface ratio channel, and performance comparable with the state-of-the-art conventional Hall thrusters. Very significant plume narrowing, accompanied by the increase of the energetic ion fraction and improvement of ion focusing, led to 50-60% increase of the thruster anode efficiency. These improvements were achieved by overrunning the discharge current in the magnetized thruster plasma
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.
Prototype dining hall energy efficiency study
Energy Technology Data Exchange (ETDEWEB)
Mazzucchi, R.P.; Bailey, S.A.; Zimmerman, P.W.
1988-06-01
The energy consumption of food service facilities is among the highest of any commercial building type, owing to the special requirements for food preparation, sanitation, and ventilation. Consequently, the US Air Force Engineering and Services Center (AFESC) contracted with Pacific Northwest Laboratory (PNL) to collect and analyze end-use energy consumption data for a prototypical dining hall and make specific recommendations on cost-effective energy conservation options. This information will be used to establish or update criteria for dining hall designs and retrofits as appropriate. 6 refs., 21 figs., 23 tabs.
Acoustics in rock and pop music halls
DEFF Research Database (Denmark)
Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian
2007-01-01
The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of rhythmic music, including rock and pop. Objective measurements were made of the acoustics of twenty rock music venues...... in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers. Correlations between the objective and subjective results lead, among others, to a recommendation for reverberation time as a function of hall volume. Since the bass...
International Nuclear Information System (INIS)
Jager, K. de
2003-01-01
Proton knock-out is studied in a broad program in Hall A at Jefferson Lab. The first experiment performed in Hall A studied the 16 O(e,e'p) reaction. Since then proton knock-out experiments have studied a variety of aspects of that reaction, from single-nucleon properties to its mechanism, such as final-state interactions and two-body currents, in nuclei from 2 H to 16 O. In this review the accomplishments of this program will be summarized and an outlook given of expected future results. (orig.)
Theory of fractional quantum Hall effect
International Nuclear Information System (INIS)
Kostadinov, I.Z.
1984-09-01
A theory of the fractional quantum Hall effect is constructed by introducing 3-particle interactions breaking the symmetry for ν=1/3 according to a degeneracy theorem proved here. An order parameter is introduced and a gap in the single particle spectrum is found. The critical temperature, critical filling number and critical behaviour are determined as well as the Ginzburg-Landau equation coefficients. A first principle calculation of the Hall current is given. 3, 5, 7 electron tunneling and Josephson interference effects are predicted. (author)
Bound values for Hall conductivity of heterogeneous medium under ...
Indian Academy of Sciences (India)
- ditions 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 ...
International Nuclear Information System (INIS)
Auverlot, Dominique; Beeeker, Etienne; Hossie, Gaelle; Bettzuege, Marc Oliver; Helm, Dieter; Roques, Fabien
2015-08-01
A synthesis of contributions is firstly proposed in this collective publication. In this synthesis, the authors describes the crisis faced by European energy (economic crisis, closure of some thermal power plants due to a lack of profitability, increase of electricity prices, low CO 2 quota prices resulting in a greater use of coal, an ageing refinery system, dependence on the Russian gas for some countries), identify four principles which could be used as guidelines for the European policy (responsibility, solidarity, economic rationality, resilience), define seven recommendations as objectives of a European energy policy. Then, the contributions address the following topics: security of electricity supply, security of European Union's gas supply called into question again, reforming the ETS market to strengthen the credibility of the European climate policy, a necessary evolution of the European energy and climate policy, the issue of a definition of a European energy policy as a dogma or a strategy, the challenge for building up a sustainable and consistent European energy and climate policy
DEFF Research Database (Denmark)
This special issue of Angles marks the three hundredth anniversary of the Union of the two kingdoms of Scotland and England. The nature and development of the relations between the constituent parts of the United Kingdom is a fascinating topic also to outside observers, and some of the contributi...... of the contributions to this volume deal with the Union in a comparative European context. Both Scottish nationalism and Scottish unionism are analysed, and Anglo-Scottish relations are looked at from historical, sociological, linguistic and literary angles...
A Small Modular Laboratory Hall Effect Thruster
Lee, Ty Davis
Electric propulsion technologies promise to revolutionize access to space, opening the door for mission concepts unfeasible by traditional propulsion methods alone. The Hall effect thruster is a relatively high thrust, moderate specific impulse electric propulsion device that belongs to the class of electrostatic thrusters. Hall effect thrusters benefit from an extensive flight history, and offer significant performance and cost advantages when compared to other forms of electric propulsion. Ongoing research on these devices includes the investigation of mechanisms that tend to decrease overall thruster efficiency, as well as the development of new techniques to extend operational lifetimes. This thesis is primarily concerned with the design and construction of a Small Modular Laboratory Hall Effect Thruster (SMLHET), and its operation on argon propellant gas. Particular attention was addressed at low-cost, modular design principles, that would facilitate simple replacement and modification of key thruster parts such as the magnetic circuit and discharge channel. This capability is intended to facilitate future studies of device physics such as anomalous electron transport and magnetic shielding of the channel walls, that have an impact on thruster performance and life. Preliminary results demonstrate SMLHET running on argon in a manner characteristic of Hall effect thrusters, additionally a power balance method was utilized to estimate thruster performance. It is expected that future thruster studies utilizing heavier though more expensive gases like xenon or krypton, will observe increased efficiency and stability.
June 1992 Hall B collaboation meeting
International Nuclear Information System (INIS)
Dennis, L.
1992-01-01
The Hall B collaboration meeting at the CEBAF 1992 Summer Workshop consisted of technical and physics working group meetings, a special beam line devices working group meeting the first meeting of the membership committee, a technical representatives meeting and a full collaboration meeting. Highlights of these meetings are presented in this report
Chapin Hall Projects and Publications. Autumn 1999.
Chicago Univ., IL. Chapin Hall Center for Children.
This guide chronicles the ongoing work and writings of the Chapin Hall Center for Children at the University of Chicago, a policy research center dedicated to bringing sound information, rigorous analyses, innovative ideas, and an independent, multidisciplinary perspective to bear on policies and programs affecting children. This guide, organized…
Quantum Hall Conductivity and Topological Invariants
Reyes, Andres
2001-04-01
A short survey of the theory of the Quantum Hall effect is given emphasizing topological aspects of the quantization of the conductivity and showing how topological invariants can be derived from the hamiltonian. We express these invariants in terms of Chern numbers and show in precise mathematical terms how this relates to the Kubo formula.
Room acoustic properties of concert halls
DEFF Research Database (Denmark)
Gade, Anders Christian
1996-01-01
A large database of values of various room acoustic parameters has provided the basis for statistical analyses of how and how much the acoustic properties of concert halls are influenced by their size, shape, and absorption area (as deduced from measured reverberation time). The data have been...
Pseudospin anisotropy classification of quantum Hall ferromagnets
Czech Academy of Sciences Publication Activity Database
Jungwirth, Tomáš; MacDonald, A. H.
2000-01-01
Roč. 63, č. 3 (2000), s. 035305-1 - 035305-9 ISSN 0163-1829 R&D Projects: GA ČR GA202/98/0085 Institutional research plan: CEZ:AV0Z1010914 Keywords : quantum Hall ferromagnets * anisotropy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.065, year: 2000
Anomalous Hall effect in disordered multiband metals
Czech Academy of Sciences Publication Activity Database
Kovalev, A.A.; Sinova, Jairo; Tserkovnyak, Y.
2010-01-01
Roč. 105, č. 3 (2010), 036601/1-036601/4 ISSN 0031-9007 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.621, year: 2010
Anomalous Hall conductivity: Local orbitals approach
Czech Academy of Sciences Publication Activity Database
Středa, Pavel
2010-01-01
Roč. 82, č. 4 (2010), 045115/1-045115/9 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100521 Keywords : anomalous Hall effect * Berry phase correction * orbital polarization momentum Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010
Quantization and hall effect: necessities and difficulties
International Nuclear Information System (INIS)
Ahmed Bouketir; Hishamuddin Zainuddin
1999-01-01
The quantization procedure is a necessary tool for a proper understanding of many interesting quantum phenomena in modern physics. In this note, we focus on geometrical framework for such procedures, particularly the group-theoretic approach and their difficulties. Finally we look through the example of Hall effect as a quantized macroscopic phenomenon with group-theoretic quantization approach. (author)
Spin Hall effect on a noncommutative space
International Nuclear Information System (INIS)
Ma Kai; Dulat, Sayipjamal
2011-01-01
We study the spin-orbital interaction and the spin Hall effect of an electron moving on a noncommutative space under the influence of a vector potential A(vector sign). On a noncommutative space, we find that the commutator between the vector potential A(vector sign) and the electric potential V 1 (r(vector sign)) of the lattice induces a new term, which can be treated as an effective electric field, and the spin Hall conductivity obtains some correction. On a noncommutative space, the spin current and spin Hall conductivity have distinct values in different directions, and depend explicitly on the noncommutative parameter. Once this spin Hall conductivity in different directions can be measured experimentally with a high level of accuracy, the data can then be used to impose bounds on the value of the space noncommutativity parameter. We have also defined a new parameter, σ=ρθ (ρ is the electron concentration, θ is the noncommutativity parameter), which can be measured experimentally. Our approach is based on the Foldy-Wouthuysen transformation, which gives a general Hamiltonian of a nonrelativistic electron moving on a noncommutative space.
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.
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
Magnetoresistance in quantum Hall metals due to Pancharatnam ...
Indian Academy of Sciences (India)
Abstract. We derive the trial Hall resistance formula for the quantum Hall metals to address both the integer and fractional quantum Hall effects. Within the degenerate (and crossed) Landau levels, and in the presence of changing magnetic field strength, one can invoke two physical processes responsible for the electron ...
Destruction of the fractional quantum Hall effect by disorder
International Nuclear Information System (INIS)
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
A Hall probe technique for characterizing high-temperature superconductors
International Nuclear Information System (INIS)
Zhang, J.; Sheldon, P.; Ahrenkiel, R.K.
1992-01-01
Thin-film GaAs Hall probes were fabricated by molecular beam epitaxy technology. A contactless technique was developed to characterize thin-film, high-temperature superconducting (HTSC) materials. The Hall probes detected the ac magnetic flux penetration through the high-temperature superconducting materials. The Hall detector has advantages over the mutual inductance magnetic flux detector
Spin-singlet hierarchy in the fractional quantum Hall effect
Ino, Kazusumi
1999-01-01
We show that the so-called permanent quantum Hall states are formed by the integer quantum Hall effects on the Haldane-Rezayi quantum Hall state. Novel conformal field theory description along with this picture is deduced. The odd denominator plateaux observed around $\
Energy Technology Data Exchange (ETDEWEB)
Owerre, S. A., E-mail: solomon@aims.ac.za [African Institute for Mathematical Sciences, 6 Melrose Road, Muizenberg, Cape Town 7945, South Africa and Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, Ontario N2L 2Y5 (Canada)
2016-07-28
Quite recently, the magnon Hall effect of spin excitations has been observed experimentally on the kagome and pyrochlore lattices. The thermal Hall conductivity κ{sup xy} changes sign as a function of magnetic field or temperature on the kagome lattice, and κ{sup xy} 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 κ{sup xy} 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 T{sup 2} 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.
International Nuclear Information System (INIS)
Lynch, A.
1991-01-01
William T. R. Fox's pre-nuclear age analysis provides an excellent starting point for the authors' discussion of the role of nuclear weapons in Soviet security policy. By pointing to some of the non-nuclear, more properly geopolitical sources of peace in East-West relations, Fox's forceful analysis serves as a reminder to approach the authors' study with caution. Too often, there has been a tendency to reduce the etiology of war and peace in East-West relations to its nuclear aspect without proper regard for other, primarily geopolitical, components which provide the all-important context in which nuclear weapons work their indisputable deterrent effect. Two geopolitical sources for the relative peace in post-war East-West relations have been the inability of either the Soviet Union or the United states to employ direct military force in politically significant terms against the vital interests of the other; and an abiding preference, on the part of both, for a divided Germany within a divided Europe. Any other plausible alternative, of course, would almost certainly have involved a united Germany and the related likelihood that it would either gravitate to one or the other alliance or, itself, would constitute the third leg of an intrinsically unstable tri-polar relationship. This paper reports that the prevailing inclination to analyze East-West security as a direct function of nuclear deterrence (witness the Western consternation about INF and denuclearization, and the proliferation of think-tank study groups on post-nuclear security) begs the probability that there are in fact a variety of deeply rooted structures of stability in East-West relations and so exaggerates the delicacy of the existing security order in Europe. to an extent, this follows form the general acceptance of deterrence theory in the West, especially in the United States, and the undoubtedly singular character and role of nuclear weapons in that order
European Union Energy Research
International Nuclear Information System (INIS)
Valdalbero, D.R.; Schmitz, B.; Raldow, W.; Poireau, M.
2007-01-01
This article presents an extensive state of the art of the energy research conducted at European Union level between 1984 and 2006, i.e. from the first to the sixth European Community Framework Programmes (FP1-FP6) for Research, Technological Development and Demonstration (RTD and D). The FP is the main legal tool and financial instrument of EU RTD and D policy. It sets the objectives, priorities and budgets for a period of several years. It has been complemented over time with a number of policy oriented initiatives and notably with the launch of the European Research Area. FP7 will cover the period 2007-2013 and will have a total budget of more than euros 50 billion. Energy has been a main research area in Europe since the founding Treaties (European Coal and Steel Community, European Atomic Energy Community-Euratom and European Economic Community), and energy RTD and D has always been a substantial part of common EU research. Nevertheless, when inflation and successive European enlargements are taken into account, over time the RTD and D effort in the field of energy has decreased significantly in relative terms. In nominal terms it has remained relatively stable at about euros 500 million per year. For the next years (FP7), it is expected that energy will still represent about 10 % of total EU research effort but with an annual budget of more than euros 800 million per year. This article presents a detailed review of the thematic areas and budget in both European nuclear energy research (fusion and fission) and non-nuclear energy research (energy efficiency/rational use of energy, fossil fuels, CO 2 capture and storage, fuel cells and hydrogen, renewable energy sources, strategic energy research/socio-economy). (authors)
European Union: US Hegemonic Competitor
National Research Council Canada - National Science Library
Kellar, Ronald
2001-01-01
.... Intergovernmentalism in the European Community has evolved into an economic form of supranationalism with the persona change form Community to Union after ratification of the Treaty of Maastricht in 1993...
Public Sector Unions and Privatization
DEFF Research Database (Denmark)
Foged, Søren Kjær; Aaskoven, Lasse
2016-01-01
Privatization varies considerably among local governments. One of the oft-listed explanations is the ability of public employees to block privatization. However, many studies on the influence of public employees on privatization do not use very precise measures of the influence of public employees...... Danish municipalities in 2012, we are able to measure the strength of the public eldercare union as well as the number of the public eldercare workers relative to the number of local voters. We find that the increased union strength measured in terms of union density at the municipal level leads...... to substantially and significantly less privatization through the voucher market. By comparison, the estimated relationship between the relative number of public workers and privatization does not reach statistical significance. Features of the voucher market and qualitative evidence suggest that the union...
DEFF Research Database (Denmark)
Jensen, Mads Dagnis; Snaith, Holly
2018-01-01
When on 23 June 2016 a majority voted in favour of the United Kingdom (UK) leaving the European Union (EU), it generated a host of unknowns. Prior to the referendum, scholars had already started to anticipate the implications of a potential Brexit from different perspectives, including considering...... lie and suggesting where Britain’s exit will leave the greatest strategic vacuums. The subsequent analysis centres on the actors that will likely win and lose from the UK’s exit from the Union....
Coordination in the European Union
Martin Feldstein
2013-01-01
This paper examines the sources of current conflict within the EU and the EMU. The topics discussed include the recent ECB policy of bond buying (the OMT policy), the attempts to advance the "European Project" of stronger political union (the fiscal compact, the banking union, and the proposals for budget supervision). Contrary to the claims of the European leadership, the progress that has been made has been by individual countries and not by coordinated action. The special problems of Franc...
Vocation or Vocational? Reviewing European Union Education and Mobility Structures
Hadfield, Amelia; Summerby-Murray, Robert
2016-01-01
This article examines the role that education plays in European Union (EU) integration. We ask whether efforts which historically have been designed to endow European students with a "knowledge of Europe" in terms of an understanding of culture, politics and sensibility have been circumscribed by, or augmented, by the recently…
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
Valley-chiral quantum Hall state in graphene superlattice structure
Tian, H. Y.; Tao, W. W.; Wang, J.; Cui, Y. H.; Xu, N.; Huang, B. B.; Luo, G. X.; Hao, Y. H.
2016-05-01
We theoretically investigate the quantum Hall effect in a graphene superlattice (GS) system, in which the two valleys of graphene are coupled together. In the presence of a perpendicular magnetic field, an ordinary quantum Hall effect is found with the sequence σxy=ν e^2/h(ν=0,+/-1,+/-2,\\cdots) . At the zeroth Hall platform, a valley-chiral Hall state stemming from the single K or K' valley is found and it is localized only on one sample boundary contributing to the longitudinal conductance but not to the Hall conductivity. Our findings may shed light on the graphene-based valleytronics applications.
Accurate micro Hall effect measurements on scribe line pads
DEFF Research Database (Denmark)
Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei
2009-01-01
Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...... be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 Ã— 430 Â¿m2, and the probe pitches range from 20 Â¿m to 50 Â¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...
Why do people join trade unions?
DEFF Research Database (Denmark)
Toubøl, Jonas; Jensen, Carsten Strøby
level on union recruitment, which is not done before. Workplace union density is taken to measure the strength of the workplace’s custom of being union member creating an instrumental incentive to join the union. Self-placement on a political left-right scale measures political attitude taken...
Predictors of Time to Union After Operative Fixation of Closed Ankle Fractures.
Matson, Andrew P; Hamid, Kamran S; Adams, Samuel B
2017-08-01
Ankle fractures are common and represent a significant burden to society. We aim to report the rate of union as determined by clinical and radiographic data, and to identify factors that predict time to union. A cohort of 112 consecutive patients with isolated, closed, operative malleolar ankle fractures treated with open reduction and internal fixation was retrospectively reviewed for time to clinical union. Clinical union was defined based on radiographic and clinical parameters, and delayed union was defined by time to union >12 weeks. Injury characteristics, patient factors and treatment variables were recorded, and statistical techniques employed included the Chi-square test, the Student's T-test, and multivariate linear regression modeling. Forty-two (37.5%) of patients who achieved union did so in less than 12 weeks, and 69 (61.6%) of these patients demonstrated delayed union at a mean of 16.7 weeks (range, 12.1-26.7 weeks), and the remaining patient required revision surgery. Factors associated with higher rates of delayed union or increased time to union included tobacco use, bimalleolar fixation, and high energy mechanism (all punion were BMI, dislocation of the tibiotalar joint, external fixation for initial stabilization and delay of definitive management (all punion following open reduction and internal fixation of closed ankle fractures. These findings should assist with patient counseling, and help guide the provider when considering adjunctive therapies that promote bone healing. Prognostic, Level IV: Case series.
Giant photonic Hall effect in magnetophotonic crystals.
Merzlikin, A M; Vinogradov, A P; Inoue, M; Granovsky, A B
2005-10-01
We have considered a simple, square, two-dimensional (2D) PC built of a magneto-optic matrix with square holes. It is shown that using such a magnetophotonic crystal it is possible to deflect a light beam at very large angles by applying a nonzero external magnetic field. The effect is called the giant photonic Hall effect (GPHE) or the magnetic superprism effect. The GPHE is based on magneto-optical properties, as is the photonic Hall effect [B. A. van Tiggelen and G. L. J. A. Rikken, in, edited by V. M. Shalaev (Springer-Verlag, Berlin, 2002), p. 275]; however GPHE is not caused by asymmetrical light scattering but rather by the influence of an external magnetic field on the photonic band structure.
Assessment of elevator rope using Hall Sensor
Energy Technology Data Exchange (ETDEWEB)
Lee, Jong O; Yoon, Woon Ha; Son, Young Ho; Kim, Jung Woo [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Lee, Jong Ku [Pukyung National University, Pusan (Korea, Republic of)
2003-07-01
Defect detection of wire rope for an elevator was investigated through the measurement of magnetic flux leakage. The types of defect usually found in wire rope categorized such as inner and outer wire breakage and wear. The specimens that has artificial defects were magnetized via permanent magnet, and measurement of magnetic flux leakage on the defects was performed with Hall sensor. In wire broken model, a defect smaller than 0.4 mm and 1 mm in depth on outer and inner wire rope, respectively, could be detected well. In wear model, smaller defect could not be detected clearly, however, appearance of changing of total magnetic flux during magnetic pole of the sensor passing through a defect 0.2 mm in depth at 4 mm or above width could make possible to detect it. From the results, the measurement via Hall sensor might be useful tool for defect detection of wire rope.
Assesment of elevator rope using hall sensor
Energy Technology Data Exchange (ETDEWEB)
Lee, Jong O; Yoon, Woon Ha; Son, Young Ho [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Kim, Jung Woo; Lee, Jong Ku [Pukyong National University, Pusan (Korea, Republic of)
2003-05-15
Defect detection of wire rope for an elevator was investigated through the measurement of magnetic flux leakage. The types of defect usually found in wire rope categorized such as inner and outer wire breakage and wear. The specimens that has artificial defects were magnetized via permanent magnet, and measurement of magnetic flux leakage on the defects was performed with Hall sensor. In wire broken model, a defect smaller than 0.4mm and 1mm in depth on outer and inner wire rope, respectively, could be detected well. In wear model, smaller defect could not be detected clearly, however, appearance of changing of total magnetic flux during magnetic pole of the sensor passing through a defect 0.2mm in depth at 4mm or above width could make possible to detect it. From the results, the measurement via Hall sensor might be useful tool for defect detection of wire rope.
Infinite symmetry in the quantum Hall effect
Directory of Open Access Journals (Sweden)
Lütken C.A.
2014-04-01
Full Text Available The new states of matter and concomitant quantum critical phenomena revealed by the quantum Hall effect appear to be accompanied by an emergent modular symmetry. The extreme rigidity of this infinite symmetry makes it easy to falsify, but two decades of experiments have failed to do so, and the location of quantum critical points predicted by the symmetry is in increasingly accurate agreement with scaling experiments. The symmetry severely constrains the structure of the effective quantum field theory that encodes the low energy limit of quantum electrodynamics of 1010 charges in two dirty dimensions. If this is a non-linear σ-model the target space is a torus, rather than the more familiar sphere. One of the simplest toroidal models gives a critical (correlation length exponent that agrees with the value obtained from numerical simulations of the quantum Hall effect.
Stuart Hall and Cultural Studies, circa 1983
Directory of Open Access Journals (Sweden)
Ann Curthoys
2017-11-01
Full Text Available Stuart Hall sought to internationalise theoretical debates and to create Cultural Studies as interdisciplinary. We chart his theoretical journey through a detailed examination of a series of lectures delivered in 1983 and now published for the first time. In these lectures, he discusses theorists such as E.P. Thompson, Raymond Williams, Louis Althusser, Levi Strauss and Antonio Gramsci, and explores the relationship between ideas and social structure, the specificities of class and race, and the legacies of slavery. We note his turn towards metaphors of divergence and dispersal and highlight how autobiographical and deeply personal Hall is in these lectures, especially in his ego histoire moment of traumatic memory recovery.
Hall magnetohydrodynamics: Conservation laws and Lyapunov stability
International Nuclear Information System (INIS)
Holm, D.D.
1987-01-01
Hall electric fields produce circulating mass flow in confined ideal-fluid plasmas. The conservation laws, Hamiltonian structure, equilibrium state relations, and Lyapunov stability conditions are presented here for ideal Hall magnetohydrodynamics (HMHD) in two and three dimensions. The approach here is to use the remarkable array of nonlinear conservation laws for HMHD that follow from its Hamiltonian structure in order to construct explicit Lyapunov functionals for the HMHD equilibrium states. In this way, the Lyapunov stability analysis provides classes of HMHD equilibria that are stable and whose linearized initial-value problems are well posed (in the sense of possessing continuous dependence on initial conditions). Several examples are discussed in both two and three dimensions
Music hall Markneukirchen; Musikhalle in Markneukirchen
Energy Technology Data Exchange (ETDEWEB)
Anon.
1996-01-01
The article presents the new building of the music hall Markneukirchen. From the planned use of the building result very high demands on the ventilation system in order to keep to a sound power level of less than 30 dB(A) in the hall. The building services are dealt with using numerous flowsheets and diagrams: Heat supply, ventilation system, sanitary system, building management, instrumentation and control, electric and lighting systems. (BWI) [Deutsch] Der vorliegende Beitrag stellt den Neubau der Musikhalle Markneukirchen vor. Durch das Nutzungskonzept ergeben sich fuer die Einhaltung eines Schalleistungspegels von weniger als 30 dB(A) im Saalbereich an die Lueftungsanlage sehr hohe Ansprueche. Es werden die raumlufttechnischen Anlagen anhand zahlreicher Flussbilder und Abbildungen vorgestellt: Waermeversorgung, Lueftungstechnik, Sanitaertechnik, Gebaeudeleit- und MSR-Technik, Elektro- und Lichttechnik. (BWI)
Theory of fractional quantum hall effect
International Nuclear Information System (INIS)
Kostadinov, I.Z.
1985-08-01
A theory of the Fractional Quantum Hall Effect is constructed based on magnetic flux fractionization, which lead to instability of the system against selfcompression. A theorem is proved stating that arbitrary potentials fail to lift a specific degeneracy of the Landau level. For the case of 1/3 fractional filling a model 3-particles interaction is constructed breaking the symmetry. The rigid 3-particles wave function plays the role of order parameter. In a BCS type of theory the gap in the single particles spectrum is produced by the 3-particles interaction. The mean field critical behaviour and critical parameters are determined as well as the Ginsburg-Landau equation coefficients. The Hall conductivity is calculated from the first principles and its temperature dependence is found. The simultaneous tunnelling of 3,5,7 etc. electrons and quantum interference effects are predicted. (author)
Coulomb blockade in hierarchical quantum Hall droplets
International Nuclear Information System (INIS)
Cappelli, Andrea; Georgiev, Lachezar S; Zemba, Guillermo R
2009-01-01
The degeneracy of energy levels in a quantum dot of Hall fluid, leading to conductance peaks, can be readily derived from the partition functions of conformal field theory. Their complete expressions can be found for Hall states with both Abelian and non-Abelian statistics, upon adapting known results for the annulus geometry. We analyze the Abelian states with hierarchical filling fractions, ν = m/(mp ± 1), and find a non-trivial pattern of conductance peaks. In particular, each one of them occurs with a characteristic multiplicity, which is due to the extended symmetry of the m-folded edge. Experimental tests of the multiplicity can shed more light on the dynamics of this composite edge. (fast track communication)
Assessment of elevator rope using Hall Sensor
International Nuclear Information System (INIS)
Lee, Jong O; Yoon, Woon Ha; Son, Young Ho; Kim, Jung Woo; Lee, Jong Ku
2003-01-01
Defect detection of wire rope for an elevator was investigated through the measurement of magnetic flux leakage. The types of defect usually found in wire rope categorized such as inner and outer wire breakage and wear. The specimens that has artificial defects were magnetized via permanent magnet, and measurement of magnetic flux leakage on the defects was performed with Hall sensor. In wire broken model, a defect smaller than 0.4 mm and 1 mm in depth on outer and inner wire rope, respectively, could be detected well. In wear model, smaller defect could not be detected clearly, however, appearance of changing of total magnetic flux during magnetic pole of the sensor passing through a defect 0.2 mm in depth at 4 mm or above width could make possible to detect it. From the results, the measurement via Hall sensor might be useful tool for defect detection of wire rope.
Assesment of elevator rope using hall sensor
International Nuclear Information System (INIS)
Lee, Jong O; Yoon, Woon Ha; Son, Young Ho; Kim, Jung Woo; Lee, Jong Ku
2003-01-01
Defect detection of wire rope for an elevator was investigated through the measurement of magnetic flux leakage. The types of defect usually found in wire rope categorized such as inner and outer wire breakage and wear. The specimens that has artificial defects were magnetized via permanent magnet, and measurement of magnetic flux leakage on the defects was performed with Hall sensor. In wire broken model, a defect smaller than 0.4mm and 1mm in depth on outer and inner wire rope, respectively, could be detected well. In wear model, smaller defect could not be detected clearly, however, appearance of changing of total magnetic flux during magnetic pole of the sensor passing through a defect 0.2mm in depth at 4mm or above width could make possible to detect it. From the results, the measurement via Hall sensor might be useful tool for defect detection of wire rope.
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 (c) 2016 APA, all rights reserved).
Testing a Beverage and Fruit/Vegetable Education Intervention in a University Dining Hall.
Scourboutakos, Mary J; Mah, Catherine L; Murphy, Sarah A; Mazza, Frank N; Barrett, Nathanael; McFadden, Bill; L'Abbé, Mary R
2017-06-01
To test the effect of a nutrition intervention that included education and 2 labeling components on students' food choices. Repeat cross-sectional study taking place on 6 dinner occasions before and 6 afterward. The study was conducted during dinner meals in a buffet-style dining hall in a university campus residence, where students paid a set price and consumed all they cared to eat. University students (n = 368 to 510) visited the cafeteria on each of the data collection dates. Fruit and vegetable consumption were encouraged; sugar-sweetened beverage consumption was discouraged using physical activity calorie equivalent labeling. Beverage choices and vegetable/fruit bar visits. Logistic regression was used to compare the proportion of student who selected each beverage, fruit, or vegetable before and after the intervention, while controlling for menu and gender as covariates. There was a significant decrease in the proportion of students selecting a sugar-sweetened beverage before vs after the intervention (49% vs 41%, respectively; P = .004) and an increase in students choosing water (43% vs 54%, respectively; P < .001). There was a significant increase in students who took fruit after the intervention (36%; P < .001) vs before (30%). The number of students visiting the vegetable bar significantly increased from 60% to 72% (P < .001). This intervention may be a way to encourage healthy dietary choices in campus dining halls. Copyright © 2017. Published by Elsevier Inc.
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.
CERN PhotoLab
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.
Anomalous hall effect in ferromagnetic semiconductors
Czech Academy of Sciences Publication Activity Database
Jungwirth, Tomáš; Niu, Q.; MacDonald, A. H.
2002-01-01
Roč. 88, č. 20 (2002), s. 207208-1-207208-4 ISSN 0031-9007 R&D Projects: GA ČR GA202/02/0912; GA MŠk OC P5.10 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * anomalous Hall effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.323, year: 2002
A hall for assembly and cryogenic tests
International Nuclear Information System (INIS)
Beaunier, J.; Buhler, S.; Caruette, A.; Chevrollier, R.; Junquera, T.; Le Scornet, J.C.
1999-01-01
Cryodrome, an assembly hall and the testing ground for cryogenic equipment and R and D experiments for the superconducting cavities is going to be transformed for its future missions. The cryogenic utilities, especially the He low pressure pumping capacity, was rearranged and extended to a new area. Space was provided to install CRYHOLAB, a new horizontal cryostat for cavity testing. Automatic control and supervision of the utilities and the experimental area are rebuilt and updated. (authors)
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 κ2 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.
Anode Fall Formation in a Hall Thruster
International Nuclear Information System (INIS)
Dorf, Leonid A.; Raitses, Yevgeny F.; Smirnov, Artem N.; Fisch, Nathaniel J.
2004-01-01
As was reported in our previous work, accurate, nondisturbing near-anode measurements of the plasma density, electron temperature, and plasma potential performed with biased and emissive probes allowed the first experimental identification of both electron-repelling (negative anode fall) and electron-attracting (positive anode fall) anode sheaths in Hall thrusters. An interesting new phenomenon revealed by the probe measurements is that the anode fall changes from positive to negative upon removal of the dielectric coating, which appears on the anode surface during the course of Hall thruster operation. As reported in the present work, energy dispersion spectroscopy analysis of the chemical composition of the anode dielectric coating indicates that the coating layer consists essentially of an oxide of the anode material (stainless steel). However, it is still unclear how oxygen gets into the thruster channel. Most importantly, possible mechanisms of anode fall formation in a Hall thruster with a clean and a coated anodes are analyzed in this work; practical implication of understanding the general structure of the electron-attracting anode sheath in the case of a coated anode is also discussed
Josephson tunneling in bilayer quantum Hall system
International Nuclear Information System (INIS)
Ezawa, Z.F.; Tsitsishvili, G.; Sawada, A.
2012-01-01
A Bose–Einstein condensation is formed by composite bosons in the quantum Hall state. A composite boson carries the fundamental charge (−e). We investigate Josephson tunneling of such charges in the bilayer quantum Hall system at the total filling ν=1. We show the existence of the critical current for the tunneling current to be coherent and dissipationless. Our results explain recent experiments due to [L. Tiemann, Y. Yoon, W. Dietsche, K. von Klitzing, W. Wegscheider, Phys. Rev. B 80 (2009) 165120] and due to [Y. Yoon, L. Tiemann, S. Schmult, W. Dietsche, K. von Klitzing, Phys. Rev. Lett. 104 (2010) 116802]. We predict also how the critical current changes as the sample is tilted in the magnetic field. -- Highlights: ► Composite bosons undergo Bose–Einstein condensation to form the bilayer quantum Hall state. ► A composite boson is a single electron bound to a flux quantum and carries one unit charge. ► Quantum coherence develops due to the condensation. ► Quantum coherence drives the supercurrent in each layer and the tunneling current. ► There exists the critical input current so that the tunneling current is coherent and dissipationless.
Familial Pallister-Hall in adulthood.
Talsania, Mitali; Sharma, Rohan; Sughrue, Michael E; Scofield, R Hal; Lim, Jonea
2017-10-01
Pallister Hall syndrome is autosomal dominant disorder usually diagnosed in infants and children. Current diagnostic criteria include presence of hypothalamic hamartoma, post axial polydactyly and positive family history, but the disease has variable manifestations. Herein we report Pallister Hall syndrome diagnosed in a family where both patients were adults. A 59 year old man developed seizures 4 years prior to our evaluation of him, at which time imaging showed a hypothalamic hamartoma. The seizures were controlled medically. He did well until he had visual changes after a traumatic head injury. Repeat MRI showed slight expansion of the mass with formal visual field testing demonstrating bitemporal hemianopsia. There was no evidence of pituitary dysfunction except for large urine volume. He underwent surgery to debulk the hamartoma and the visual field defects improved. There was no hypopituitarism post-operatively, and the polydyspia resolved. His 29 year old daughter also had seizures and hypothalamic hamartoma. Both patients had had polydactyly with prior surgical correction in childhood. The daughter underwent genetic testing, which revealed a previously undescribed heterozygous single base pair deletion in exon 13 of the GLI3 gene causing a frameshift mutation. Further investigation into family history revealed multiple members in previous generations with polydactyly and/or seizures. Pallister-Hall syndrome is caused by an inherited autosomal dominant or de novo mutation in GLI3 gene. This rare syndrome has not had prevalence defined, however. Generally, diagnoses are made in the pediatric population. Our report adds to the few cases detected in adulthood.
Osteoporosis in the European Union
DEFF Research Database (Denmark)
Svedbom, A; Hernlund, E; Ivergård, M
2013-01-01
the burden of osteoporosis in each of the EU27 countries in 2010 and beyond. METHODS: The data on fracture incidence and costs of fractures in the EU27 were taken from a concurrent publication in this journal (Osteoporosis in the European Union: Medical Management, Epidemiology and Economic Burden......UNLABELLED: This report describes epidemiology, burden, and treatment of osteoporosis in each of the 27 countries of the European Union (EU27). INTRODUCTION: In 2010, 22 million women and 5.5 million men were estimated to have osteoporosis in the EU; and 3.5 million new fragility fractures were...
Union members at the polls in diverse trade union landscapes
DEFF Research Database (Denmark)
Arndt, Christoph; Rennwald, Line
2016-01-01
still enjoy important support from trade union members, but at the same time are under fierce competition from bourgeois and green parties among members of white-collar confederations. This reinforces the challenges for social democracy to build new voters’ coalitions in post-industrial societies....
The STEM Lecture Hall: A Study of Effective Instructional Practices for Diverse Learners
Reimer, Lynn Christine
First-generation, low-income, underrepresented minority (URM) and female undergraduates are matriculating into science, technology, engineering, and math (STEM) majors at unprecedented levels. However, a disproportionate number of these students end up graduating in non-STEM disciplines. Attrition rates have been observed to spike in conjunction with introductory STEM courses in chemistry, biology, and physics. These "gateway" courses tend to be housed in large, impersonal lecture halls. First-generation and URM students struggle in this environment, possibly because of instructors' reliance on lecture-based content delivery and rote memorization. Recent social psychological studies suggest the problem may be related to cultural mismatch, or misalignment between independent learning norms typical of American universities and interdependent learning expectancies for first-generation and URM students. Value-affirming and utility-value interventions yield impressive academic achievement gains for these students. These findings overlap with a second body of literature on culturally responsive instruction. Active gateway learning practices that emphasize interactive instruction, frequent assessment, and epistemological instruction can be successful because of their propensity to incorporate values affirming and utility-value techniques. The present study observed instruction for gateway STEM courses over a three-year period at the University of California, Irvine (N = 13,856 undergraduates in 168 courses). Exploratory polychoric factor analysis was used to identify latent variables for observational data on gateway STEM instructional practices. Variables were regressed on institutional student data. Practices implemented in large lecture halls fall into three general categories: Faculty-Student Interaction, Epistemological Instruction, and Peer Interaction . The present study found that Faculty-Student Interaction was negatively associated with student outcomes for
Experimental test of 200 W Hall thruster with titanium wall
Ding, Yongjie; Sun, Hezhi; Peng, Wuji; Xu, Yu; Wei, Liqiu; Li, Hong; Li, Peng; Su, Hongbo; Yu, Daren
2017-05-01
We designed a 200 W Hall thruster based on the technology of pushing down a magnetic field with two permanent magnetic rings. Boron nitride (BN) is an important insulating wall material for Hall thrusters. The discharge characteristics of the designed Hall thruster were studied by replacing BN with titanium (Ti). Experimental results show that the designed Hall thruster can discharge stably for a long time under a Ti channel. Experiments were performed to determine whether the channel and cathode are electrically connected. When the channel wall and cathode are insulated, the divergence angle of the plume increases, but the performance of the Hall thruster is improved in terms of thrust, specific impulse, anode efficiency, and thrust-to-power ratio. Ti exhibits a powerful antisputtering capability, a low emanation rate of gas, and a large structural strength, making it a potential candidate wall material in the design of low-power Hall thrusters.
TOWARDS THE CAPITAL MARKET UNION
Directory of Open Access Journals (Sweden)
Iulian PANAIT
2015-06-01
Full Text Available This paper discusses the main characteristics of the proposed Capital Markets Union in Europe, as they are introduced by the European Commission and various authors, and emphasises some important advantages and disadvantages of this project for the developing and frontier markets in UE, especially for Romania.
Rationalities in trade union work
DEFF Research Database (Denmark)
Buch, Anders; Andersen, Vibeke
2011-01-01
The ambition of this paper is to analyze the discursive practices of three Danish trade unions for professional and managerial staff (The Danish Society of Engineers, The Association of Lawyers and Economists, and The Danish Association of Masters and PhD’s) as found in their strategy and positio...
Intersectionality in European Union policymaking
DEFF Research Database (Denmark)
Lombardo, Emanuela; Agustin, Lise Rolandsen
2016-01-01
is particularly apt to deal with equality and diversity in policymaking. By analysing a selection of European Union policy documents on gender-based violence in the period 2000–2014, we attend to the question of what intersectionality can bring to policymaking in terms of strengthening inclusiveness and address...
Forsythe, Linda
1982-01-01
A course combining English in the workplace, information seeking and job application skills, occupational safety, and other workplace skills conducted by a community college and a major industrial union is described. The very successful program will be continued and developed based on the initial experience. (MSE)
Kamminga, Menno R.
2014-01-01
Renowned political philosopher John Rawls once expressed skepticism about the moral status of the European Union (EU). Yet generally EU scholars have either ignored Rawls or rather uncritically established positive links between his theory of domestic and international justice and the EU. This
Effects of facility backpressure on the performance and plume of a Hall thruster
Walker, Mitchell Louis Ronald
2005-07-01
this work aims to develop a fundamental understanding of how multi-kW clustered Hall thrusters operate and how to use single-engine ground-based data to predict the performance, plume interaction, and operation of a cluster. The results show that the plume and operating characteristics of the cluster are governed primarily by the facility backpressure and not the adjacent thruster. At nearly equal backpressure, the thrust is equal to the sum of the thrust of the monolithic thrusters at the lower anode flow rate. At the upper anode flow rate, the sum of the thrust of the monolithic thrusters under predicts the cluster thrust by 5%. This may be caused by each cluster element ingesting unionized propellant from the adjacent thruster. In addition, a cathode sharing investigation shows negligible change in the discharge current and cathode-to-ground voltage for thruster centerline separation distances up to 2 meters. A cathode displacement investigation shows that the Hall thruster starts reliably and performs nominally at cathode separation distances up to 1.1 meters. Collectively, the results of this work shed light on future facility designs that can reduce facility effects at pumping speeds that are not significantly above those of current facilities.
Hall Sensor Output Signal Fault-Detection & Safety Implementation Logic
Directory of Open Access Journals (Sweden)
Lee SangHun
2016-01-01
Full Text Available Recently BLDC motors have been popular in various industrial applications and electric mobility. Recently BLDC motors have been popular in various industrial applications and electric mobility. In most brushless direct current (BLDC motor drives, there are three hall sensors as a position reference. Low resolution hall effect sensor is popularly used to estimate the rotor position because of its good comprehensive performance such as low cost, high reliability and sufficient precision. Various possible faults may happen in a hall effect sensor. This paper presents a fault-tolerant operation method that allows the control of a BLDC motor with one faulty hall sensor and presents the hall sensor output fault-tolerant control strategy. The situations considered are when the output from a hall sensor stays continuously at low or high levels, or a short-time pulse appears on a hall sensor signal. For fault detection, identification of a faulty signal and generating a substitute signal, this method only needs the information from the hall sensors. There are a few research work on hall effect sensor failure of BLDC motor. The conventional fault diagnosis methods are signal analysis, model based analysis and knowledge based analysis. The proposed method is signal based analysis using a compensation signal for reconfiguration and therefore fault diagnosis can be fast. The proposed method is validated to execute the simulation using PSIM.
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...
DESIGN OF SUBSOIL IMPROVEMENT BELOW HALL FLOORS
Directory of Open Access Journals (Sweden)
Peter Turček
2017-10-01
Full Text Available The construction of an industrial park is now being prepared near the town of Nitra. The investor fixed very strict conditions for the bearing capacity and, above all, the settlement of halls and their floors. The geological conditions at the construction site are difficult: there are soft clay soils with high compressibility and low bearing capacity. A detailed analysis of soil improvement was made. Stone columns were prepared to be fitted into an approximately 5 m thick layer of soft clay. The paper shows the main steps used in the design of the stone columns.
Optically induced Hall effect in semiconductors
Energy Technology Data Exchange (ETDEWEB)
Idrish Miah, M; Gray, E Mac A, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)
2009-03-01
We describe an experiment which investigates the effect of a longitudinal electric field on the spin-polarized carriers generated by a circularly polarized light in semiconductors. Our experiment observes the effect as a Hall voltage resulting from nonequilibrium magnetization induced by the spin-carrier electrons accumulating at the transverse boundaries of the sample as a result of asymmetries in scattering for spin-up and spin-down electrons in the presence of spin-orbit interaction. It is found that the effect depends on the longitudinal electric field and doping density as well as on temperature. The results are presented by discussing the dominant spin relaxation mechanisms in semiconductors.
Fractional quantization and the quantum hall effect
International Nuclear Information System (INIS)
Guerrero, J.; Calixto, M.; Aldaya, V.
1998-01-01
Quantization with constrains is considered in a group-theoretical framework, providing a precise characterization of the set of good operators, i.e., those preserving the constrained Hilbert space, in terms of the representation of the subgroup of constraints. This machinery is applied to the quantization of the torus as symplectic manifold, obtaining that fractional quantum numbers are permitted, provided that we allow for vector valued representations. The good operators turn out to be the Wilson loops and, for certain representations of the subgroup of constraints, the modular transformations. These results are applied to the Fractional Quantum Hall Effect, where interesting implications are derived
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.
The fractional quantum Hall effect goes organic
International Nuclear Information System (INIS)
Smet, Jurgen
2000-01-01
Physicists have been fascinated by the behaviour of two-dimensional electron gases for the past two decades. All of these experiments were performed on inorganic semiconductor devices, most of them based on gallium arsenide. Indeed, until recently it was thought that the subtle effects that arise due to electron-electron interactions in these devices required levels of purity that could not be achieved in other material systems. However, Hendrik Schoen, Christian Kloc and Bertram Batlogg of Bell Laboratories in the US have now observed the fractional quantum Hall effect - the most dramatic signature of electron-electron interactions - in two organic semiconductors. (U.K.)
A Compton polarimeter for CEBAF Hall A
Energy Technology Data Exchange (ETDEWEB)
Bardin, G; Cavata, C; Frois, B; Juillard, M; Kerhoas, S; Languillat, J C; Legoff, J M; Mangeot, P; Martino, J; Platchkov, S; Rebourgeard, P; Vernin, P; Veyssiere, C; CEBAF Hall A Collaboration
1994-09-01
The physic program at CEBAF Hall A includes several experiments using 4 GeV polarized electron beam: parity violation in electron elastic scattering from proton and {sup 4}He, electric form factor of the proton by recoil polarization, neutron spin structure function at low Q{sup 2}. Some of these experiments will need beam polarization measurement and monitoring with an accuracy close to 4%, for beam currents ranging from 100 nA to 100 microA. A project of a Compton Polarimeter that will meet these requirements is presented. It will comprise four dipoles and a symmetric cavity consisting of two identical mirrors. 1 fig., 10 refs.
Hall conductivity for two dimensional magnetic systems
International Nuclear Information System (INIS)
Desbois, J.; Ouvry, S.; Texier, C.
1996-01-01
A Kubo inspired formalism is proposed to compute the longitudinal and transverse dynamical conductivities of an electron in a plane (or a gas of electrons at zero temperature) coupled to the potential vector of an external local magnetic field, with the additional coupling of the spin degree of freedom of the electron to the local magnetic field (Pauli Hamiltonian). As an example, the homogeneous magnetic field Hall conductivity is rederived. The case of the vortex at the origin is worked out in detail. A perturbative analysis is proposed for the conductivity in the random magnetic impurity problem (Poissonian vortices in the plane). (author)
Portfolio Optimization for Multiple Group Credit Unions
National Research Council Canada - National Science Library
Willis, John
1999-01-01
...) to diversify, credit unions now have the opportunity to market their services to specific employee groups or industries which can reduce the overall risk to the credit unions' health or solvency...
Gender Differences in Attitudes toward Unions.
Schur, Lisa A.; Kruse, Douglas L.
1992-01-01
A 1984 survey of 250 union members (86 women and 164 men) showed that most women, especially those in private sector white collar jobs, were interested in joining unions but face barriers such as family responsibilities. (SK)
Partnership Creates Centre for Union Studies
Smart, Carol; Roman, Stephen
1978-01-01
A unique cooperative venture between the city of Coventry and local trade unions is establishing a library collection of books, periodicals, historical documents, tapes, and films dealing with unions, labor studies, and industrial problems. (JAB)
Unions and the Economic Basis of Attitudes
White, Michael; Bryson, Alex
2016-01-01
Unions make differences to employee satisfaction that correspond to their effects on individual economic advantage. Panel data reveal how changes in economic circumstance and changes in job satisfaction are linked to changes in union coverage. When individuals move into a union covered job they receive a wage mark-up and express enhanced pay satisfaction. Conversely, those moving from a union covered job on average lose any mark-up and have significantly reduced satisfaction. Similar findings...
ETUDE - European Trade Union Distance Education.
Creanor, Linda; Walker, Steve
2000-01-01
Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…
The African Union and Conflict Management
2006-03-02
USAWC STRATEGY RESEARCH PROJECT THE AFRICAN UNION AND CONFLICT MANAGEMENT by Lieutenant Colonel Flemming Mathiasen Royal Danish Army Colonel Patrick...AUTHOR: Lieutenant Colonel Flemming Mathiasen TITLE: The African Union and Conflict Management FORMAT: Strategy Research Project DATE: 2 March 2006...WORD COUNT: 5850 PAGES: 28 KEY TERMS: African Union, Africa, Conflict Management , Capabilities CLASSIFICATION: Unclassified Africa is a continent with a
Transit-time instability in Hall thrusters
International Nuclear Information System (INIS)
Barral, Serge; Makowski, Karol; Peradzynski, Zbigniew; Dudeck, Michel
2005-01-01
Longitudinal waves characterized by a phase velocity of the order of the velocity of ions have been recurrently observed in Hall thruster experiments and simulations. The origin of this so-called ion transit-time instability is investigated with a simple one-dimensional fluid model of a Hall thruster discharge in which cold ions are accelerated between two electrodes within a quasineutral plasma. A short-wave asymptotics applied to linearized equations shows that plasma perturbations in such a device consist of quasineutral ion acoustic waves superimposed on a background standing wave generated by discharge current oscillations. Under adequate circumstances and, in particular, at high ionization levels, acoustic waves are amplified as they propagate, inducing strong perturbation of the ion density and velocity. Responding to the subsequent perturbation of the column resistivity, the discharge current generates a standing wave, the reflection of which sustains the generation of acoustic waves at the inlet boundary. A calculation of the frequency and growth rate of this resonance mechanism for a supersonic ion flow is proposed, which illustrates the influence of the ionization degree on their onset and the approximate scaling of the frequency with the ion transit time. Consistent with experimental reports, the traveling wave can be observed on plasma density and velocity perturbations, while the plasma potential ostensibly oscillates in phase along the discharge
Cylindrical Hall Thrusters with Permanent Magnets
International Nuclear Information System (INIS)
Raitses, Yevgeny; Merino, Enrique; Fisch, Nathaniel J.
2010-01-01
The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT.
Bimetric Theory of Fractional Quantum Hall States
Directory of Open Access Journals (Sweden)
Andrey Gromov
2017-11-01
Full Text Available We present a bimetric low-energy effective theory of fractional quantum Hall (FQH states that describes the topological properties and a gapped collective excitation, known as the Girvin-Macdonald-Platzman (GMP mode. The theory consists of a topological Chern-Simons action, coupled to a symmetric rank-2 tensor, and an action à la bimetric gravity, describing the gapped dynamics of a spin-2 mode. The theory is formulated in curved ambient space and is spatially covariant, which allows us to restrict the form of the effective action and the values of phenomenological coefficients. Using bimetric theory, we calculate the projected static structure factor up to the k^{6} order in the momentum expansion. To provide further support for the theory, we derive the long-wave limit of the GMP algebra, the dispersion relation of the GMP mode, and the Hall viscosity of FQH states. The particle-hole (PH transformation of the theory takes a very simple form, making the duality between FQH states and their PH conjugates manifest. We also comment on the possible applications to fractional Chern insulators, where closely related structures arise. It is shown that the familiar FQH observables acquire a curious geometric interpretation within the bimetric formalism.
Hypernuclear Spectroscopy at JLab Hall C
International Nuclear Information System (INIS)
Hashimoto, Osamu; Chiba, Atsushi; Doi, Daisuke; Fujii, Yu; Toshiyuki, Gogami; Kanda, Hiroki; Kaneta, M.; Kawama, Daisuke; Maeda, Kazushige; Maruta, Tomofumi; Matsumura, Akihiko; Nagao, Sho; Nakamura, Satoshi; Shichijo, Ayako; Tamura, Hirokazu; Taniya, Naotaka; Yamamoto, Taku; Yokota, Kosuke; Kato, S.; Sato, Yoshinori; Takahashi, Toshiyuki; Noumi, Hiroyuki; Motoba, T.; Hiyama, E.; Albayrak, Ibrahim; Ates, Ozgur; Chen, Chunhua; Christy, Michael; Keppel, Cynthia; Kohl, Karl; Li, Ya; Liyanage, Anusha Habarakada; Tang, Liguang; Walton, T.; Ye, Zhihong; Yuan, Lulin; Zhu, Lingyan; Baturin, Pavlo; Boeglin, Werner; Dhamija, Seema; Markowitz, Pete; Raue, Brian; Reinhold, Joerg; Hungerford, Ed; Ent, Rolf; Fenker, Howard; Gaskell, David; Horn, Tanja; Jones, Mark; Smith, Gregory; Vulcan, William; Wood, Stephen; Johnston, C.; Simicevic, Neven; Wells, Stephen; Samanta, Chhanda; Hu, Bitao; Shen, Ji; Wang, W.; Zhang, Xiaozhuo; Zhang, Yi; Feng, Jing; Fu, Y.; Zhou, Jian; Zhou, S.; Jiang, Yi; Lu, H.; Yan, Xinhu; Ye, Yunxiu; Gan, Liping; Ahmidouch, Abdellah; Danagoulian, Samuel; Gasparian, Ashot; Elaasar, Mostafa; Wesselmann, Frank; Asaturyan, Arshak; Margaryan, Amur; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Tadevosyan, Vardan; Androic, Darko; Furic, Miroslav; Petkovic, Tomislav; Seva, Tomislav; Niculescu, Gabriel; Niculescu, Maria-Ioana; Rodriguez, Victor; Cisbani, Evaristo; Cusanno, Francesco; Garibaldi, Franco; Urciuoli, Guido; De Leo, Raffaele; Maronne, S.; Achenbach, Carsten; Pochodzalla, J.
2010-01-01
Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e(prime)K + ) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e(prime)K + ) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the 'Tilt method' was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7 ΛHe and 28 ΛAl together with that of 12 ΛB that achieved resolution better than 500 keV(FWHM) were obtained. The third generation experiment, E05-115, has completed data taking with an experimental setup combining a new splitter magnet, high resolution electron spectrometer (HES) and the HKS used in the 2nd generation experiment. The data were accumulated with targets of 7 Li, 9 Be, 10 B, 12 C and 52 Cr as well as with those of CH 2 and H 2 O for calibration. The analysis is under way with particular emphasis of determining precision absolute hypernuclear masses. In this article, hypernuclear spectroscopy program in the wide mass range at JLab Hall C that has undergone three generation is described.
Bimetric Theory of Fractional Quantum Hall States
Gromov, Andrey; Son, Dam Thanh
2017-10-01
We present a bimetric low-energy effective theory of fractional quantum Hall (FQH) states that describes the topological properties and a gapped collective excitation, known as the Girvin-Macdonald-Platzman (GMP) mode. The theory consists of a topological Chern-Simons action, coupled to a symmetric rank-2 tensor, and an action à la bimetric gravity, describing the gapped dynamics of a spin-2 mode. The theory is formulated in curved ambient space and is spatially covariant, which allows us to restrict the form of the effective action and the values of phenomenological coefficients. Using bimetric theory, we calculate the projected static structure factor up to the k6 order in the momentum expansion. To provide further support for the theory, we derive the long-wave limit of the GMP algebra, the dispersion relation of the GMP mode, and the Hall viscosity of FQH states. The particle-hole (PH) transformation of the theory takes a very simple form, making the duality between FQH states and their PH conjugates manifest. We also comment on the possible applications to fractional Chern insulators, where closely related structures arise. It is shown that the familiar FQH observables acquire a curious geometric interpretation within the bimetric formalism.
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
Undulator Hall Air Temperature Fault Scenarios
International Nuclear Information System (INIS)
Sevilla, J.
2010-01-01
Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about ±2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.
Nuclear Energy and European Union
International Nuclear Information System (INIS)
Picamal, B.
2010-01-01
The interest shown by the European Institutions in the energy debates, in which the nuclear energy is included as a key component within the energy mix, is obvious. Climate change and energy supply have pushed some countries to publicly express their interest for developing the nuclear energy. These positions are however in contradiction with some others within the European Union which are a lot more critical towards this type of energy and where face-out policies still prevail. Despite the fact that the use of the nuclear energy will remain within the competence of each Member State, the European Union will continue to play a prominent role in the development of an energy strategy based on a low carbon economy. (Author)
The European Union's Africa Policy
DEFF Research Database (Denmark)
Olsen, Gorm Rye
2013-01-01
For a number of years, there has been an international debate on whether and to what extent small member states can influence the common external policies of the European Union. Recent research on the role of small EU states concludes that these states are neither per se political dwarfs nor power...... including North–South and specifically Africa policies. Five separate analyses are carried out addressing the question of Nordicization and Europeanization. Based on the empirical analyses, it is not possible to confirm the hypothesis that a Nordicization of the European Union's Africa policy has taken...... place. Rather, it appears adequate to talk about convergence of policies between the Nordics and the EU and therefore, the Africa policies of both actors are basically the result of Europeanization....
DEFF Research Database (Denmark)
Busato, Francesco; Addessi, William
The paper investigates the nexus between labor and financial markets, focusing on the interaction between labor union behavior in setting wages, firms' investment strategy and asset prices. The way unions set wage claims after observing firm's financial performance increases the volatility of firms......' returns and the riskiness of corporate ownership. To remunerate this higher volatility and stronger risk, firms' equities have to grant high return. This mechanism is able to offer an explanation of for the "equity puzzle", that is it can explain the difference between equity returns and the risk free...... rate. It is a welcome result that the simulated excess return is about the empirical estimate and this result is obtained with a logarithmic specification of the shareholders preferences....
European Union: fears and hopes
Directory of Open Access Journals (Sweden)
Gilles ROUET
2016-06-01
Full Text Available This contribution analyses some data from Eurobarometer 83, spring 2015, especially to draw a map of Fears. The European Union is a divided space and one of the main consequences of the budget (financial crisis of Greece, followed by the crisis caused by the arrival of thousands of immigrants is an enhanced communication difficulty between the Western and Eastern parts of the EU But all citizens have some new rights with the European Citizenship, which are additional. One of the main issues for the future could be to change the fundamental basis of the Union, thus trying to organize a new articulation between local and supranational, with another role for States, for example to change the organisation of European elections, and to pursue the connection of public spaces with mobility.
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
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…
What is the Hallé? | Smith | Philosophical Papers
African Journals Online (AJOL)
The bulk of the paper examines the difficulty of reconciling the view that the Hallé is several individuals with two prima facie plausible theses about the manner of its persistence through time. The paper is structured around some remarks made by Peter Simons about groups, and the Hallé in particular, in his Parts.
Spin hall effect associated with SU(2) gauge field
Tao, Y.
2010-01-01
In this paper, we focus on the connection between spin Hall effect and spin force. Here we investigate that the spin force due to spin-orbit coupling, which, in two-dimensional system, is equivalent to forces of Hirsch and Chudnovsky besides constant factors 3 and frac{3}{2} respectively, is a part of classic Anandan force, and that the spin Hall effect is an anomalous Hall effect. Furthermore, we develop the method of AC phase to derive the expression for the spin force, and note that the most basic spin Hall effect indeed originate from the AC phase and is therefore an intrinsic quantum mechanical property of spin. This method differs from approach of Berry phase in the study of anomalous Hall effect , which is the intrinsic property of the perfect crystal. On the other hand, we use an elegant skill to show that the Chudnovsky-Drude model is reasonable. Here we have improved the theoretical values of spin Hall conductivity of Chudnovsky. Compared to the theoretical values of spin Hall conductivity in the Chudnovsky-Drude model, ours are in better agreement with experimentation. Finally, we discuss the relation between spin Hall effect and fractional statistics.
Energy spectrum, dissipation, and spatial structures in reduced Hall magnetohydrodynamic
Energy Technology Data Exchange (ETDEWEB)
Martin, L. N.; Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Gomez, D. O. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, CONICET, Buenos Aires (Argentina)
2012-05-15
We analyze the effect of the Hall term in the magnetohydrodynamic turbulence under a strong externally supported magnetic field, seeing how this changes the energy cascade, the characteristic scales of the flow, and the dynamics of global magnitudes, with particular interest in the dissipation. Numerical simulations of freely evolving three-dimensional reduced magnetohydrodynamics are performed, for different values of the Hall parameter (the ratio of the ion skin depth to the macroscopic scale of the turbulence) controlling the impact of the Hall term. The Hall effect modifies the transfer of energy across scales, slowing down the transfer of energy from the large scales up to the Hall scale (ion skin depth) and carrying faster the energy from the Hall scale to smaller scales. The final outcome is an effective shift of the dissipation scale to larger scales but also a development of smaller scales. Current sheets (fundamental structures for energy dissipation) are affected in two ways by increasing the Hall effect, with a widening but at the same time generating an internal structure within them. In the case where the Hall term is sufficiently intense, the current sheet is fully delocalized. The effect appears to reduce impulsive effects in the flow, making it less intermittent.
Quantifying Spin Hall Angles from Spin Pumping : Experiments and Theory
Mosendz, O.; Pearson, J.E.; Fradin, F.Y.; Bauer, G.E.W.; Bader, S.D.; Hoffmann, A.
2010-01-01
Spin Hall effects intermix spin and charge currents even in nonmagnetic materials and, therefore, ultimately may allow the use of spin transport without the need for ferromagnets. We show how spin Hall effects can be quantified by integrating Ni80Fe20|normal metal (N) bilayers into a coplanar
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…
Theory of the quantum hall effects in lattice systems
International Nuclear Information System (INIS)
Kliros, G.S.
1990-06-01
The Fractional Quantum Hall Effect is identified as an Integral Quantum Hall Effect of electrons on a lattice with an even number of statistical flux quanta. A variational wavefunction in terms of the Hofstadter lattice eigenstates is proposed. (author). 21 refs
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.
Critical current in the Integral Quantum Hall Effect
International Nuclear Information System (INIS)
Kostadinov, I.Z.
1985-11-01
A multiparticle theory of the Integral Quantum Hall Effect (IQHE) was constructed operating with pairs wave function as an order parameter. The IQHE is described with bosonic macroscopic states while the fractional QHE with fermionic ones. The calculation of the critical current and Hall conductivity temperature dependence is presented. (author)
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…
CERN. Geneva
2010-01-01
Chers Collègues,Je me permets de vous rappeler qu'une réunion publique organisée par le Département HR se tiendra aujourd'hui:Vendredi 30 avril 2010 à 9h30 dans l'Amphithéâtre principal (café offert dès 9h00).Durant cette réunion, des informations générales seront données sur:le CERN Admin e-guide, qui est un nouveau guide des procédures administratives du CERN ayant pour but de faciliter la recherche d'informations pratiques et d'offrir un format de lecture convivial;le régime d'Assurance Maladie de l'Organisation (présentation effectuée par Philippe Charpentier, Président du CHIS Board) et;la Caisse de Pensions (présentation effectuée par Théodore Economou, Administrateur de la Caisse de Pensions du CERN).Une transmission simultanée de cette réunion sera assur...
A Novel Hall Effect Sensor Using Elaborate Offset Cancellation Method
Directory of Open Access Journals (Sweden)
Vlassis N. Petoussis
2009-01-01
Full Text Available The Hall effect is caused by a traverse force that is formed in the electrons or holes of metal element or semiconductor when are polarized by current source and simultaneously all the system it is found vertical in external magnetic field. Result is finally the production of difference of potential (Hall voltage in address vertical in that of current and magnetic field directions. In the present work is presented a new Hall sensor exploiting the former operation. In combination with his pioneering form and using dynamic spinning current technique with an elaborate sequence, it leads to satisfactory results of produced Hall voltage with small noise in a presence of external magnetic field. Anyone can see both the spinning current and anti-Hall technique in the same sensor simultaneously.
Migrants and Their Experiences of Time: Edward T. Hall Revisited
Directory of Open Access Journals (Sweden)
Elisabeth Schilling
2009-01-01
Full Text Available In this paper we reassess the scientific heritage of Edward T. HALL and his contribution to the area of intercultural communication. The key objectives of our study are to demonstrate the applicability of HALL's theory of culture to empirical research and to establish its compatibility with other methods. Specifically, we propose that Alfred SCHÜTZ's phenomenology of sociality be taken as an extension to HALL. The connection between HALL and SCHÜTZ is made possible by the mutual emphases on the temporal dimension of culture and the temporal aspects of migration. With these foci we analyze six narratives by two groups of migrants: German and Russian. By combining HALL's theory of the cultural time with SCHÜTZ's phenomenological perspective on time and the Other and then applying them to empirical data, we show the terms in which different cultures experience time. URN: urn:nbn:de:0114-fqs0901357
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.
Magnetic Measurements of the Background Field in the Undulator Hall
International Nuclear Information System (INIS)
Fisher, Andrew
2010-01-01
The steel present in the construction of the undulator hall facility has the potential for changing the ambient fields present in the undulator hall. This note describes a measurement done to make a comparison between the fields in the hall and in the Magnetic Measurement Facility. In order for the undulators to have the proper tuning, the background magnetic field in the Undulator Hall should agree with the background field in the Magnetic Measurements Facility within .5 gauss. In order to verify that this was the case measurements were taken along the length of the undulator hall, and the point measurements were compared to the mean field which was measured on the MMF test bench.
Unconventional quantum Hall effect in Floquet topological insulators
Tahir, M.; Vasilopoulos, P.; Schwingenschlö gl, Udo
2016-01-01
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.
Revitalizing the Malaysian Trade Union Movement
DEFF Research Database (Denmark)
Wad, Peter
2012-01-01
The article takes an historic perspective on contemporary issues of trade union revival in Malaysia, focusing on the challenge of raising union density and analysing the process of organizing employees in the strategically important electronics industry. It concludes that the political support...... for transnational corporations in the electronics industry is declining. This strategic shift enables union activists to bypass enterprise and state-based unions and to establish larger, regionally based unions. However, newly organized unions have not yet overcome resistance from global corporations, nor have...... organizations prefer non-partisan engagement. In order to revitalize themselves, the unions must demonstrate to the Malaysian public that they are both relevant and important for increased productivity and that they can play a significant role in enabling Malaysia to move beyond the middle-income ‘trap’ towards...
Social Customs and Trade Union Membership
DEFF Research Database (Denmark)
Ibsen, Christian Lyhne; Toubøl, Jonas; Jensen, Daniel Sparwath
2017-01-01
In this article, we investigate the effect of social customs on one of the most important instances of collective action, namely, workers uniting in trade unions. Although many studies have used social custom theory to explain unionization, existing studies have not adequately analysed social...... customs at the workplace. Using workplace union density as a proxy for social custom, this analysis improves existing studies in a number of ways. First, multi-level analyses of a large panel data set from Denmark reveal that there is a significant positive effect of workplace union density...... in unionization are required to create self-sustaining social customs for union membership. Thirdly, we test the acceleration using segmented regression analysis and find a significant acceleration around 45–65 per cent workplace union density. In the conclusion, we discuss the implications of our study...
Planar Hall Effect Sensors for Biodetection
DEFF Research Database (Denmark)
Rizzi, Giovanni
. In the second geometry (dPHEB) half of the sensor is used as a local negative reference to subtract the background signal from magnetic beads in suspension. In all applications below, the magnetic beads are magnetised using the magnetic field due to the bias current passed through the sensor, i.e., no external...... as labels and planar Hall effect bridge (PHEB) magnetic field sensor as readout for the beads. The choice of magnetic beads as label is motivated by the lack of virtually any magnetic background from biological samples. Moreover, magnetic beads can be manipulated via an external magnetic field...... hybridisation in real-time, in a background of suspended magnetic beads. This characteristic is employed in single nucleotide polymorphism (SNP) genotyping, where the denaturation of DNA is monitored in real-time upon washing with a stringency buffer. The sensor setup includes temperature control and a fluidic...
Numerical investigation of a Hall thruster plasma
International Nuclear Information System (INIS)
Roy, Subrata; Pandey, B.P.
2002-01-01
The dynamics of the Hall thruster is investigated numerically in the framework of a one-dimensional, multifluid macroscopic description of a partially ionized xenon plasma using finite element formulation. The model includes neutral dynamics, inelastic processes, and plasma-wall interaction. Owing to disparate temporal scales, ions and neutrals have been described by set of time-dependent equations, while electrons are considered in steady state. Based on the experimental observations, a third order polynomial in electron temperature is used to calculate ionization rate. The results show that in the acceleration channel the increase in the ion number density is related to the decrease in the neutral number density. The electron and ion velocity profiles are consistent with the imposed electric field. The electron temperature remains uniform for nearly two-thirds of the channel; then sharply increases to a peak before dropping slightly at the exit. This is consistent with the predicted electron gyration velocity distribution
Quantum Hall effect on Riemann surfaces
Tejero Prieto, Carlos
2009-06-01
We study the family of Landau Hamiltonians compatible with a magnetic field on a Riemann surface S by means of Fourier-Mukai and Nahm transforms. Starting from the geometric formulation of adiabatic charge transport on Riemann surfaces, we prove that Hall conductivity is proportional to the intersection product on the first homology group of S and therefore it is quantized. Finally, by using the theory of determinant bundles developed by Bismut, Gillet and Soul, we compute the adiabatic curvature of the spectral bundles defined by the holomorphic Landau levels. We prove that it is given by the polarization of the jacobian variety of the Riemann surface, plus a term depending on the relative analytic torsion.
Quantum Hall effect on Riemann surfaces
International Nuclear Information System (INIS)
Tejero Prieto, Carlos
2009-01-01
We study the family of Landau Hamiltonians compatible with a magnetic field on a Riemann surface S by means of Fourier-Mukai and Nahm transforms. Starting from the geometric formulation of adiabatic charge transport on Riemann surfaces, we prove that Hall conductivity is proportional to the intersection product on the first homology group of S and therefore it is quantized. Finally, by using the theory of determinant bundles developed by Bismut, Gillet and Soul, we compute the adiabatic curvature of the spectral bundles defined by the holomorphic Landau levels. We prove that it is given by the polarization of the jacobian variety of the Riemann surface, plus a term depending on the relative analytic torsion.
Frequency spectrum of Calder Hall reactor noise
International Nuclear Information System (INIS)
Cummins, J.D.
1960-01-01
The frequency spectrum of the noise power of Calder Hall reactor No. 1 has been obtained by analysing a tape recording of the backed off power. The root mean square noise power due to all frequencies above 0.001 cycles per second was found to be 0.13%. The noise power for this reactor, is due mainly to modulations of the power level by reactivity variations caused in turn by gas temperature changes. These gas temperature changes are caused by a Cyclic variation in the feedwater regulator to the heat exchanger. The apparatus and method used to determine the noise power are described in this memorandum. It is shown that for frequencies in the range 0.001 to 0.030 cycles per second the noise spectrum falls at 60 decibels per decade of frequency. (author)
OPTICS. Quantum spin Hall effect of light.
Bliokh, Konstantin Y; Smirnova, Daria; Nori, Franco
2015-06-26
Maxwell's equations, formulated 150 years ago, ultimately describe properties of light, from classical electromagnetism to quantum and relativistic aspects. The latter ones result in remarkable geometric and topological phenomena related to the spin-1 massless nature of photons. By analyzing fundamental spin properties of Maxwell waves, we show that free-space light exhibits an intrinsic quantum spin Hall effect—surface modes with strong spin-momentum locking. These modes are evanescent waves that form, for example, surface plasmon-polaritons at vacuum-metal interfaces. Our findings illuminate the unusual transverse spin in evanescent waves and explain recent experiments that have demonstrated the transverse spin-direction locking in the excitation of surface optical modes. This deepens our understanding of Maxwell's theory, reveals analogies with topological insulators for electrons, and offers applications for robust spin-directional optical interfaces. Copyright © 2015, American Association for the Advancement of Science.
Determination of the Hall Thruster Operating Regimes
International Nuclear Information System (INIS)
L. Dorf; V. Semenov; Y. Raitses; N.J. Fisch
2002-04-01
A quasi one-dimensional (1-D) steady-state model of the Hall thruster is presented. For the same discharge voltage two operating regimes are possible -- with and without the anode sheath. For given mass flow rate, magnetic field profile and discharge voltage a unique solution can be constructed, assuming that the thruster operates in one of the regimes. However, we show that for a given temperature profile the applied discharge voltage uniquely determines the operating regime: for discharge voltages greater than a certain value, the sheath disappears. That result is obtained over a wide range of incoming neutral velocities, channel lengths and widths, and cathode plane locations. It is also shown that a good correlation between the quasi 1-D model and experimental results can be achieved by selecting an appropriate electron mobility and temperature profile
Chaotic waves in Hall thruster plasma
International Nuclear Information System (INIS)
Peradzynski, Zbigniew; Barral, S.; Kurzyna, J.; Makowski, K.; Dudeck, M.
2006-01-01
The set of hyperbolic equations of the fluid model describing the acceleration of plasma in a Hall thruster is analyzed. The characteristic feature of the flow is the existence of a trapped characteristic; i.e. there exists a characteristic line, which never intersects the boundary of the flow region in the thruster. To study the propagation of short wave perturbations, the approach of geometrical optics (like WKB) can be applied. This can be done in a linear as well as in a nonlinear version. The nonlinear version describes the waves of small but finite amplitude. As a result of such an approach one obtains so called transport equation, which are governing the wave amplitude. Due to the existence of trapped characteristics this transport equation appears to have chaotic (turbulent) solutions in both, linear and nonlinear versions
Spin Hall magnetoresistance at high temperatures
International Nuclear Information System (INIS)
Uchida, Ken-ichi; Qiu, Zhiyong; Kikkawa, Takashi; Iguchi, Ryo; Saitoh, Eiji
2015-01-01
The temperature dependence of spin Hall magnetoresistance (SMR) in Pt/Y 3 Fe 5 O 12 (YIG) bilayer films has been investigated in a high temperature range from room temperature to near the Curie temperature of YIG. The experimental results show that the magnitude of the magnetoresistance ratio induced by the SMR monotonically decreases with increasing the temperature and almost disappears near the Curie temperature. We found that, near the Curie temperature, the temperature dependence of the SMR in the Pt/YIG film is steeper than that of a magnetization curve of the YIG; the critical exponent of the magnetoresistance ratio is estimated to be 0.9. This critical behavior of the SMR is attributed mainly to the temperature dependence of the spin-mixing conductance at the Pt/YIG interface
Concept of Operating Indoor Skiing Halls with
DEFF Research Database (Denmark)
Paul, Joachim
2003-01-01
Indoor skiing halls are conventionally operated at low temperatures and with either crushed ice as snow substitute or snow made from freezing water in cold air. Both systems have a high energy demand for air cooling, floor freezing and consequently snow harvest. At the same time the snow at the top...... floor cooling/freezing and insulation become obsolete, significant savings in piping and building costs can be achieved. Due to the much higher evaporating temperature for the refrigeration system, the energy demand is kept low. Since the same equipment is used for both snowmaking and air cooling......, the running time of the equipment is high, resulting in a better economy. Using Binary Snow, with its unique qualities such as fluffy, crisp, white and ¿ since made daily ¿ "fresh and hygienic", offers great advantages in operating costs, investment costs and quality....
Geometrical Description of fractional quantum Hall quasiparticles
Park, Yeje; Yang, Bo; Haldane, F. D. M.
2012-02-01
We examine a description of fractional quantum Hall quasiparticles and quasiholes suggested by a recent geometrical approach (F. D. M. Haldane, Phys. Rev. Lett. 108, 116801 (2011)) to FQH systems, where the local excess electric charge density in the incompressible state is given by a topologically-quantized ``guiding-center spin'' times the Gaussian curvature of a ``guiding-center metric tensor'' that characterizes the local shape of the correlation hole around electrons in the fluid. We use a phenomenological energy function with two ingredients: the shear distortion energy of area-preserving distortions of the fluid, and a local (short-range) approximation to the Coulomb energy of the fluctuation of charge density associated with the Gaussian curvature. Quasiparticles and quasiholes of the 1/3 Laughlin state are modeled as ``punctures'' in the incompressible fluid which then relax by geometric distortion which generates Gaussian curvature, giving rise to the charge-density profile around the topological excitation.
Cathode Effects in Cylindrical Hall Thrusters
Energy Technology Data Exchange (ETDEWEB)
Granstedt, E.M.; Raitses, Y.; Fisch, N. J.
2008-09-12
Stable operation of a cylindrical Hall thruster (CHT) has been achieved using a hot wire cathode, which functions as a controllable electron emission source. It is shown that as the electron emission from the cathode increases with wire heating, the discharge current increases, the plasma plume angle reduces, and the ion energy distribution function shifts toward higher energies. The observed effect of cathode electron emission on thruster parameters extends and clarifies performance improvements previously obtained for the overrun discharge current regime of the same type of thruster, but using a hollow cathode-neutralizer. Once thruster discharge current saturates with wire heating, further filament heating does not affect other discharge parameters. The saturated values of thruster discharge parameters can be further enhanced by optimal placement of the cathode wire with respect to the magnetic field.
On-Chip Microwave Quantum Hall Circulator
Directory of Open Access Journals (Sweden)
A. C. Mahoney
2017-01-01
Full Text Available 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 1/1000th 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 μm 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.
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
50 KW Class Krypton Hall Thruster Performance
Jacobson, David T.; Manzella, David H.
2003-01-01
The performance of a 50-kilowatt-class Hall thruster designed for operation on xenon propellant was measured using kryton propellant. The thruster was operated at discharge power levels ranging from 6.4 to 72.5 kilowatts. The device produced thrust ranging from 0.3 to 2.5 newtons. The thruster was operated at discharge voltages between 250 and 1000 volts. At the highest anode mass flow rate and discharge voltage and assuming a 100 percent singly charged condition, the discharge specific impulse approached the theoretical value. Discharge specific impulse of 4500 seconds was demonstrated at a discharge voltage of 1000 volts. The peak discharge efficiency was 64 percent at 650 volts.
Magnon Hall effect on the Lieb lattice.
Cao, Xiaodong; Chen, Kai; He, Dahai
2015-04-29
Ferromagnetic insulators without inversion symmetry may show magnon Hall effect (MHE) in the presence of a temperature gradient due to the existence of Dzyaloshinskii-Moriya interaction (DMI). In this theoretical study, we investigate MHE on a lattice with inversion symmetry, namely the Lieb lattice, where the DMI is introduced by adding an external electric field. We show the nontrivial topology of this model by examining the existence of edge states and computing the topological phase diagram characterized by the Chern numbers of different bands. Together with the topological phase diagram, we can further determine the sign and magnitude of the transverse thermal conductivity. The impact of the flat band possessed by this model on the thermal conductivity is discussed by computing the Berry curvature analytically.
Photonic spin Hall effect at metasurfaces.
Yin, Xiaobo; Ye, Ziliang; Rho, Junsuk; Wang, Yuan; Zhang, Xiang
2013-03-22
The spin Hall effect (SHE) of light is very weak because of the extremely small photon momentum and spin-orbit interaction. Here, we report a strong photonic SHE resulting in a measured large splitting of polarized light at metasurfaces. The rapidly varying phase discontinuities along a metasurface, breaking the axial symmetry of the system, enable the direct observation of large transverse motion of circularly polarized light, even at normal incidence. The strong spin-orbit interaction deviates the polarized light from the trajectory prescribed by the ordinary Fermat principle. Such a strong and broadband photonic SHE may provide a route for exploiting the spin and orbit angular momentum of light for information processing and communication.
A Charlwood; K Hansen; David Metcalf
2000-01-01
Dispersion in pay is lower among union members than among non-unionists. This reflects two factors. First, union members and jobs are more homogeneous than their non-union counterparts. Second, union wage policies within and across firms lower pay dispersion. Unions'' minimum wage targets also truncate the lower tail of the union distribution. There are two major consequences of these egalitarian union wage policies. First, the return to human capital is lower in firms which recognise unions ...
Nonadiabatic effects in the Quantum Hall regime
International Nuclear Information System (INIS)
Page, D.A.; Brown, E.
1993-01-01
The authors consider the effect of a finite electric field on the states of a Bloch electron in two dimensions, with a uniform magnetic field present. They make use of the concept of electric time translation symmetry and treat the electric and magnetic fields symmetrically in a time dependent formalism. In addition to a wave vector k, the states are characterized by a frequency specifying the behavior under electric time translations. An effective Hamiltonian is employed to obtain the splitting of an isolated Bloch band into open-quotes frequencyclose quotes subbands. The time-averaged velocity and energy of the states are expressed in terms of the frequency dispersion. The relationship to the Stark ladder eigenstates in a scalar potential representation of the electric field is examined. This is seen to justify the use of the averaged energy in determining occupation of the states. In the weak electric field (adiabatic) limit, an expression is recovered for the quantized Hall conductivity of a magnetic subband as a topological invariant. A numerical procedure is outlined and results obtained over a range of electric field strengths. A transition between strong and weak field regimes is seen, with level repulsions between the frequencies playing an important role. The numerical results show how the magnetic subband structure and quantized Hall conductivity emerge as the electric field becomes weaker. In this regime, the behavior can be understood by comparison to the predictions of the adiabatic approximation. The latter predicts crossings in the frequencies at certain locations in wave vector space. Nonadiabatic effects are seen to produce gaps in the frequency spectrum at these locations. 35 refs., 14 figs
Temperature dependence of collapse of quantized hall resistance
International Nuclear Information System (INIS)
Tanaka, Hiroyasu; Kawashima, Hironori; Iizuka, Hisamitsu; Fukuda, Hideaki; Kawaji, Shinji
2006-01-01
Similarity is observed in the deviation of Hall resistance from the quantized value with the increase in the source-drain current I SD in our butterfly-type Hall bars and in the Hall bars used by Jeanneret et al., while changes in the diagonal resistivity ρ xx with I SD are significantly different between these Hall bars. The temperature dependence of the critical Hall electric field F cr (T) for the collapse of R H (4) measured in these Hall bars is approximated using F cr (T) = F cr (0)(1 - (T/T cr ) 2 ). Here, the critical Hall electric field at zero temperature depends on the magnetic field B as F cr (0) ∝ B 3/2 . Theoretical considerations are given on F cr (T) on the basis of a temperature-dependent mobility edge model and a schema of temperature-dependent inter-Landau level tunneling probability arising from the Fermi distribution function. The former does not fit in with the I SD dependence of activation energy in ρ xx . (author)
Spontaneous Hall effect in a chiral p-wave superconductor
Furusaki, Akira; Matsumoto, Masashige; Sigrist, Manfred
2001-08-01
In a chiral superconductor with broken time-reversal symmetry a ``spontaneous Hall effect'' may be observed. We analyze this phenomenon by taking into account the surface properties of a chiral superconductor. We identify two main contributions to the spontaneous Hall effect. One contribution originates from the Bernoulli (or Lorentz) force due to spontaneous currents running along the surfaces of the superconductor. The other contribution has a topological origin and is related to the intrinsic angular momentum of Cooper pairs. The latter can be described in terms of a Chern-Simons-like term in the low-energy field theory of the superconductor and has some similarities with the quantum Hall effect. The spontaneous Hall effect in a chiral superconductor is, however, nonuniversal. Our analysis is based on three approaches to the problem: a self-consistent solution of the Bogoliubov-de Gennes equation, a generalized Ginzburg-Landau theory, and a hydrodynamic formulation. All three methods consistently lead to the same conclusion that the spontaneous Hall resistance of a two-dimensional superconducting Hall bar is of order h/(ekFλ)2, where kF is the Fermi wave vector and λ is the London penetration depth; the Hall resistance is substantially suppressed from a quantum unit of resistance. Experimental issues in measuring this effect are briefly discussed.
Hall current effects in dynamic magnetic reconnection solutions
International Nuclear Information System (INIS)
Craig, I.J.D.; Heerikhuisen, J.; Watson, P.G.
2003-01-01
The impact of Hall current contributions on flow driven planar magnetic merging solutions is discussed. The Hall current is important if the dimensionless Hall parameter (or normalized ion skin depth) satisfies c H >η, where η is the inverse Lundquist number for the plasma. A dynamic analysis of the problem shows, however, that the Hall current initially manifests itself, not by modifying the planar reconnection field, but by inducing a non-reconnecting perpendicular 'separator' component in the magnetic field. Only if the stronger condition c H 2 >η is satisfied can Hall currents be expected to affect the planar merging. These analytic predictions are then tested by performing a series of numerical experiments in periodic geometry, using the full system of planar magnetohydrodynamic (MHD) equations. The numerical results confirm that the nature of the merging changes dramatically when the Hall coupling satisfies c H 2 >η. In line with the analytic treatment of sheared reconnection, the coupling provided by the Hall term leads to the emergence of multiple current layers that can enhance the global Ohmic dissipation at the expense of the reconnection rate. However, the details of the dissipation depend critically on the symmetries of the simulation, and when the merging is 'head-on' (i.e., comprises fourfold symmetry) the reconnection rate can be enhanced
Graphene and the universality of the quantum Hall effect
DEFF Research Database (Denmark)
Tzalenchuk, A.; Janssen, T. J.B.M.; Kazakova, O.
2013-01-01
The quantum Hall effect allows the standard for resistance to be defined in terms of the elementary charge and Planck's constant alone. The effect comprises the quantization of the Hall resistance in two-dimensional electron systems in rational fractions of RK=h/e2=25812.8074434(84) Ω (Mohr P. J....... the unconventional quantum Hall effect and then present in detail the route, which led to the most precise quantum Hall resistance universality test ever performed.......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...
Women, Working Families, and Unions
Janelle Jones; John Schmitt; Nicole Woo
2014-01-01
One of every nine women in the United States (11.8 percent in 2013) is represented by a union at her place of work. The annual number of hours of paid work performed by women has increased dramatically over the last four decades. In 1979, the typical woman was on the job 925 hours per year; by 2012, the typical woman did 1,664 hours of paid work per year. Meanwhile, women's share of unpaid care work and housework has remained high. Various time-use studies conclude that women continue to do a...
Trade unions and energy policy
International Nuclear Information System (INIS)
Evans, M.
1984-01-01
The subject is discussed under the headings: introduction (the review of energy policy by the Trades Union Congress); energy objectives and the energy crisis; energy planning (a planning framework for supply and demand; energy demand management; public planning inquiries; a plan for Britain; beyond Britain); a low energy growth strategy (UK primary energy demand); choice of supplies (coal; oil and gas; nuclear energy); new sources of energy (e.g.solar, geothermal, biofuels, wave, wind, tidal); conservation; health and safety - employers in the energy industries; conclusions. (U.K.)
Soviet Union's Nuclear Power Program
International Nuclear Information System (INIS)
Anon.
1991-01-01
Glasnost has dramatically increased the availability of information about the Soviet Union's nuclear industry. In the future, even more information is likely to become known as Soviet participation in international forums increases. Not only is much more general information now available, but up-to-date details are regularly provided, including information such as the Soviet nuclear industry's strategic direction and goals, recent reactor design changes, safety inspection results, and reports of public opposition and protest. This article summarizes the current status of the Soviet nuclear power program, reconciling the often conflicting reports from various public sources
Passmore, Cheryl
2002-01-01
Describes the use of plastic identity badges with photographs and barcodes issued to all administrators, teachers, staff members, and students in grades 6-12 at the Cleveland Hill Union Free School District in Cheektowaga, New York. (PKP)
Signal conditioning and processing for metallic Hall sensors.
Czech Academy of Sciences Publication Activity Database
Entler, Slavomír; Ďuran, Ivan; Sládek, P.; Vayakis, G.; Kočan, M.
2017-01-01
Roč. 123, November (2017), s. 783-786 ISSN 0920-3796. [SOFT 2016: Symposium on Fusion Technology /29./. Prague, 05.09.2016-09.09.2016] R&D Projects: GA MŠk LG14002 Institutional support: RVO:61389021 Keywords : Hall sensor * Lock-in * Synchronous detection * Current spinning * Hall effect * Planar hall effect suppression Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.319, year: 2016 http://www.sciencedirect.com/science/article/pii/S0920379617305070
Anomalous Hall effect in Fe/Gd bilayers
Xu, W. J.; Zhang, Bei; Liu, Z. X.; Wang, Z.; Li, W.; Wu, Z. B.; Yu, R. H.; Zhang, Xixiang
2010-01-01
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
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.
Acoustic investigations of concert halls for rock music
DEFF Research Database (Denmark)
Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian
2007-01-01
Objective measurement data and subjective evaluations have been collected from 20 small-/medium-sized halls in Denmark used for amplified rhythmic music concerts (pop, rock, jazz). The purpose of the study was to obtain knowledge about optimum acoustic conditions for this type of hall. The study...... is motivated by the fact that most concert tickets sold in Denmark relate to concerts within these genres in this kind of venue. The subjective evaluations were carried out by professional musicians and sound engineers who responded on the basis of their experiences working in these (and other) halls. From...
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
All Optical Measurement Proposed for the Photovoltaic Hall Effect
International Nuclear Information System (INIS)
Oka, Takashi; Aoki, Hideo
2011-01-01
We propose an all optical way to measure the recently proposed p hotovoltaic Hall effect , i.e., a Hall effect induced by a circularly polarized light in the absence of static magnetic fields. This is done in a pump-probe experiment with the Faraday rotation angle being the probe. The Floquet extended Kubo formula for photo-induced optical response is formulated and the ac-Hall conductivity is calculated. We also point out the possibility of observing the effect in two layered graphene, three-dimensional graphite, and more generally in multi-band systems such as materials described by the dp-model.
Determination of intrinsic spin Hall angle in Pt
Energy Technology Data Exchange (ETDEWEB)
Wang, Yi; Deorani, Praveen; Qiu, Xuepeng; Kwon, Jae Hyun; Yang, Hyunsoo, E-mail: eleyang@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 117576 (Singapore)
2014-10-13
The spin Hall angle in Pt is evaluated in Pt/NiFe bilayers by spin torque ferromagnetic resonance measurements and is found to increase with increasing the NiFe thickness. To extract the intrinsic spin Hall angle in Pt by estimating the total spin current injected into NiFe from Pt, the NiFe thickness dependent measurements are performed and the spin diffusion in the NiFe layer is taken into account. The intrinsic spin Hall angle of Pt is determined to be 0.068 at room temperature and is found to be almost constant in the temperature range of 13–300 K.
Determination of intrinsic spin Hall angle in Pt
International Nuclear Information System (INIS)
Wang, Yi; Deorani, Praveen; Qiu, Xuepeng; Kwon, Jae Hyun; Yang, Hyunsoo
2014-01-01
The spin Hall angle in Pt is evaluated in Pt/NiFe bilayers by spin torque ferromagnetic resonance measurements and is found to increase with increasing the NiFe thickness. To extract the intrinsic spin Hall angle in Pt by estimating the total spin current injected into NiFe from Pt, the NiFe thickness dependent measurements are performed and the spin diffusion in the NiFe layer is taken into account. The intrinsic spin Hall angle of Pt is determined to be 0.068 at room temperature and is found to be almost constant in the temperature range of 13–300 K.
Energy Technology Data Exchange (ETDEWEB)
Shan, H.; Hu, E.; Zhi, L.; Zhang, L.; Zhang, M.
2016-07-01
Purpose: Given the current lack of literature in the background of China labor force, this study aims to investigate the relationships among job satisfaction, perceived union instrumentality, and unionization from a reference-frame-based perspective and explore the referred relationships in the context of Chinese labor market. Design/methodology/approach: The study introduces perceived union instrumentality as a mediator to the relationship between job satisfaction and unionization. The applicability of western theories was tested in the Chinese context by a questionnaire survey on 390 employees who were working in private sectors of Jiangsu Province in China. Four hypothesis were proposed and tested by data analysis to verify the model. Findings: The study found that most aspects of job satisfaction were negatively correlated with unionization and perceived union instrumentality, while perceived union instrumentality had a positive relationship with unionization. Perceived union instrumentality was also found to have a mediating effect on the relationship between job satisfaction and unionization. Originality/value: The paper adapted and tested a number of western industrial relation theories in the backdrop of China, contributing to the gap in Chinese-context research by examining the relationships between job satisfaction, unionization and union instrumentality of Chinese employees. It pays a regular contribution to labor union studies both inside and outside China. (Author)
Linking Public Administration and Law Studies within European Union
Directory of Open Access Journals (Sweden)
Mihaela V. Cărăuşan
2012-05-01
Full Text Available The year 1987 represented for us, scholars, the turning point for the Europeanization of highdegree studies. The European Region Action Scheme for the Mobility of University Students (ERASMUS isa European Union student exchange program which has proved its utility in the last two decade. The publicadministration and law studies are two of the fields of studies which have benefited from the ERASMUSProgramme. In this respect we will try to learn the lesson of internationalization from the European contactthrough ERASMUS programme. The ‘win win’ for students is not just in the increase of knowledge in thearea of administrative sciences and law, but also in the share of cultures. The ERASMUS gives students abetter sense of what it means to be a European citizen. In addition, many employers highly value such aperiod abroad, which increases the students’ employability and job prospects.
The European Union: Challenges and Perspectives
Directory of Open Access Journals (Sweden)
Botescu Ion
2017-01-01
If to all these we add the protectionist measures that the new president of the United States wishes to implement, as well as some deterioration in the European Union credibility generated by Brexit, the bureaucratic aspects that characterize the European institutions, etc., we can outline the context of the European Union, which requires a series of measures to ensure the progress of the European Union as a whole and, in particular, the effective integration of each Community country.
Trade union policy and nuclear power
International Nuclear Information System (INIS)
Elliot, D.
1981-01-01
The subject is discussed under the headings: introduction; energy policy; the beginning of doubt; SERA's role [SERA = Socialist Environment and Resources Association]; the 1980 nuclear debate [within the trade union movement]; the 1981 nuclear debate [within the trade union movement]; the issues reviewed (supply and demand; safety and employment; security); review of policy trends; conclusions. Appendix: a review of union policy statements. (U.K.)
Currency Unions, Trade Flows, and Capital Flows
James Yetman
2003-01-01
Trade within currency unions has been shown to be much larger than outside of currency unions, even after factoring in many relevant variables. The existing empirical evidence is based on reduced form models of trade, and therefore indicates that there exists a high correlation between currency union membership and trade, but does not indicate the causality, or the mechanism at work. This paper argues that the balance of evidence points to a large and statistically significant causal relation...
Wage Setting in Democratic Labour Unions
DEFF Research Database (Denmark)
Filges, Trine
1999-01-01
In this paper, we analyse the wage setting of a democratic labour union. The union members differ with respect to their employment probabilities. The union wage only changes if the parameters of the median member change. An exogenous shock to revenue may increase the wage, even if labour demand...... is iso-elastic and unemployment benefits may have only a small effect on wages if the median member differs from the average. These findings are in accordance with empirical results....
Properties of Nonabelian Quantum Hall States
Simon, Steven H.
2004-03-01
The quantum statistics of particles refers to the behavior of a multiparticle wavefunction under adiabatic interchange of two identical particles. While a three dimensional world affords the possibilities of Bosons or Fermions, the two dimensional world has more exotic possibilities such as Fractional and Nonabelian statistics (J. Frölich, in ``Nonperturbative Quantum Field Theory", ed, G. t'Hooft. 1988). The latter is perhaps the most interesting where the wavefunction obeys a ``nonabelian'' representation of the braid group - meaning that braiding A around B then B around C is not the same as braiding B around C then A around B. This property enables one to think about using these exotic systems for robust topological quantum computation (M. Freedman, A. Kitaev, et al, Bull Am Math Soc 40, 31 (2003)). Surprisingly, it is thought that quasiparticles excitations with such nonabelian statistics may actually exist in certain quantum Hall states that have already been observed. The most likely such candidate is the quantum Hall ν=5/2 state(R. L. Willett et al, Phys. Rev. Lett. 59, 1776-1779 (1987)), thought to be a so-called Moore-Read Pfaffian state(G. Moore and N. Read, Nucl Phys. B360 362 (1991)), which can be thought of as a p-wave paired superconducting state of composite fermions(M. Greiter, X. G. Wen, and F. Wilczek, PRL 66, 3205 (1991)). Using this superconducting analogy, we use a Chern-Simons field theory approach to make a number of predictions as to what experimental signatures one should expect for this state if it really is this Moore-Read state(K. Foster, N. Bonesteel, and S. H. Simon, PRL 91 046804 (2003)). We will then discuss how the nonabelian statistics can be explored in detail using a quantum monte-carlo approach (Y. Tserkovnyak and S. H. Simon, PRL 90 106802 (2003)), (I. Finkler, Y. Tserkovnyak, and S. H. Simon, work in progress.) that allows one to explicitly drag one particle around another and observe the change in the wavefunctions
Adolescent Violent Victimization and Precocious Union Formation*
C. Kuhl, Danielle; Warner, David F.; Wilczak, Andrew
2013-01-01
This article bridges scholarship in criminology and family sociology by extending arguments about “precocious exits” from adolescence to consider early union formation as a salient outcome of violent victimization for youths. Research indicates that early union formation is associated with several negative outcomes; yet the absence of attention to union formation as a consequence of violent victimization is noteworthy. We address this gap by drawing on life course theory and data from the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of violent victimization (“street” violence) on the timing of first co-residential union formation—differentiating between marriage and cohabitation—in young adulthood. Estimates from Cox proportional hazard models show that adolescent victims of street violence experience higher rates of first union formation, especially marriage, early in the transition to adulthood; however, this effect declines with age, as such unions become more normative. Importantly, the effect of violent victimization on first union timing is robust to controls for nonviolent delinquency, substance abuse, and violent perpetration. We conclude by discussing directions for future research on the association between violent victimization and coresidential unions with an eye toward the implications of such early union formation for desistance. PMID:24431471
Adolescent Violent Victimization and Precocious Union Formation.
C Kuhl, Danielle; Warner, David F; Wilczak, Andrew
2012-11-01
This article bridges scholarship in criminology and family sociology by extending arguments about "precocious exits" from adolescence to consider early union formation as a salient outcome of violent victimization for youths. Research indicates that early union formation is associated with several negative outcomes; yet the absence of attention to union formation as a consequence of violent victimization is noteworthy. We address this gap by drawing on life course theory and data from the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of violent victimization ("street" violence) on the timing of first co-residential union formation-differentiating between marriage and cohabitation-in young adulthood. Estimates from Cox proportional hazard models show that adolescent victims of street violence experience higher rates of first union formation, especially marriage, early in the transition to adulthood; however, this effect declines with age, as such unions become more normative. Importantly, the effect of violent victimization on first union timing is robust to controls for nonviolent delinquency, substance abuse, and violent perpetration. We conclude by discussing directions for future research on the association between violent victimization and coresidential unions with an eye toward the implications of such early union formation for desistance.
Unionism Comes to the Public Sector
Richard B. Freeman
1984-01-01
This paper argues that public sector labor relations is best understood in a framework that focuses on unions' ability to shift demand curves rather than to raise wages, as is the case in the private sector. It reviews the public sector labor relations literature and finds that: (i) public sector unionism has flourished as a result of changes in laws; (2) the effects of public sector unions on wages are likely to have been underestimated; (3) public sector unions have a somewhat different eff...
Quantum Theory of Conducting Matter Superconductivity and Quantum Hall Effect
Fujita, Shigeji; Godoy, Salvador
2009-01-01
Explains major superconducting properties including zero resistance, Meissner effect, sharp phase change, flux quantization, excitation energy gap, and Josephson effects using quantum statistical mechanical calculations. This book covers the 2D superconductivity and the quantum Hall effects
Magnesium Hall Thruster for Solar System Exploration, Phase II
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...
W∞ gauge theory and the quantum Hall effect
International Nuclear Information System (INIS)
Shizuya, K.
1994-05-01
It is shown that a planar system of Hall electrons coupled to an applied electromagnetic field is written in the form of a W ∞ gauge theory. The associated W ∞ gauge field is expressed nonlinearly in terms of an infinite set of multipoles of the electromagnetic field. The W ∞ transformations generate mixing among the Landau levels. They provide a systematic way to classify the electromagnetic characteristics of the Hall system according to the resolution of external probes. In particular, an exact long-wavelength connection is derived between the carrier density and the Hall conductance in the presence of electron-electron interactions. Our approach is complementary to an earlier one and reveals a dual role the W ∞ gauge symmetry plays in the Hall dynamics. (author)
Magnetohydrodynamic simulations of Gamble I POS with Hall effect
International Nuclear Information System (INIS)
Roderick, N.F.; Frese, M.H.; Peterkin, R.E.; Payne, S.S.
1989-01-01
Two dimensional single fluid magnetohydrodynamic simulations have been conducted to investigate the effects of the Hall electric field on magnetic field transport in plasma opening switches of the type used on Gamble I. The Hall terms were included in the magnetic field transport equation in the two dimensional simulation code MACH2 through the use of a generalized Ohm's law. Calculations show the Hall terms augment the field transport previously observed to occur through ion fluid motion and diffusion. For modest values of microturbulent collision frequency, board current channels were observed . Results also show the magnetic field transport to be affected by the cathode boundary conditions with the Hall terms included. In all cases center of mass motion was slight
The Dream Comes True in the Golden Hall
Institute of Scientific and Technical Information of China (English)
JianZhong; ChenJianguo
2004-01-01
Nanjing Traditional Music Ensemble has long dreamed of performing in Vienna's Golden Hall.Now the dream has come true.the whole troupe felt so exciting that they did not even sleep well during the flight.
Observation of the anomalous Hall effect in GaAs
International Nuclear Information System (INIS)
Miah, M Idrish
2007-01-01
Devices for the direct detection of the spin current, based on the anomalous Hall effect (AHE), are fabricated on n-type GaAs bulk semiconductor materials. The AHE is observed in the device when the photoinduced spin-polarized electrons are injected into it, and it is found that the effect depends on the applied electric field. The origin of the field-dependent observed Hall effect is discussed based on the D'yakonov-Perel' (DP) spin relaxation mechanism. The spin-dependent Hall effect is also found to be enhanced with increasing doping concentration. The present experimental results might have potential applications in semiconductor spintronic devices since the effect is closely related to the spin Hall effect
Observation of the anomalous Hall effect in GaAs
Energy Technology Data Exchange (ETDEWEB)
Miah, M Idrish [Nanoscale Science and Technology Centre, School of Science, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong, Chittagong - 4331 (Bangladesh)
2007-03-21
Devices for the direct detection of the spin current, based on the anomalous Hall effect (AHE), are fabricated on n-type GaAs bulk semiconductor materials. The AHE is observed in the device when the photoinduced spin-polarized electrons are injected into it, and it is found that the effect depends on the applied electric field. The origin of the field-dependent observed Hall effect is discussed based on the D'yakonov-Perel' (DP) spin relaxation mechanism. The spin-dependent Hall effect is also found to be enhanced with increasing doping concentration. The present experimental results might have potential applications in semiconductor spintronic devices since the effect is closely related to the spin Hall effect.
Nobel Prize in physics 1985: Quantum Hall effect
International Nuclear Information System (INIS)
Herrmann, R.
1986-01-01
The conditions (like very strong magnetic fields, ultralow temperatures, and occurrence of a two-dimensional electron gas in microelectronic structures) for the measurement of the quantum Hall effect are explained. Two possible measuring methods are described. Measuring results for p-Si-MOSFET, GaAs/AlGaAs heterojuntions and grain boundaries in InSb crystals are reported. Differences between normal (integer) and fractional quantum Hall effect are discussed. One of the important consequences is that by means of the quantum Hall effect the value h/e 2 can be determined with very high accuracy. In 1985 Klaus von Klitzing was awarded the Nobel Prize for his work on the quantum Hall effect
Quantum Computing With Quasiparticles of the Fractional Quantum Hall Effect
National Research Council Canada - National Science Library
Averin, Dmitri
2001-01-01
The focus of this project was the theoretical study of quantum computation based on controlled transfer of individual quasiparticles in systems of quantum antidots in the regime of the Fractional Quantum Hall Effect (FQHE...
Quantum Hall Ferroelectrics and Nematics in Multivalley Systems
Sodemann, Inti; Zhu, Zheng; Fu, Liang
2017-10-01
We study broken symmetry states at integer Landau-level fillings in multivalley quantum Hall systems whose low-energy dispersions are anisotropic. When the Fermi surface of individual pockets lacks twofold rotational symmetry, like in bismuth (111) [Feldman et al. , Observation of a Nematic Quantum Hall Liquid on the Surface of Bismuth, Science 354, 316 (2016), 10.1126/science.aag1715] and in Sn1 -xPbxSe (001) [Dziawa et al., Topological Crystalline Insulator States in Pb1 -xSnxSe , Nat. Mater. 11, 1023 (2012), 10.1038/nmat3449] surfaces, interactions tend to drive the formation of quantum Hall ferroelectric states. We demonstrate that the dipole moment in these states has an intimate relation to the Fermi surface geometry of the parent metal. In quantum Hall nematic states, like those arising in AlAs quantum wells, we demonstrate the existence of unusually robust Skyrmion quasiparticles.
Hall effects and related phenomena in disordered Rashba 2DEG
International Nuclear Information System (INIS)
Inoue, Jun-ichiro; Kato, Takashi; Bauer, Gerrit E W; Molenkamp, Laurens W
2009-01-01
We review our recent work on the spin and anomalous Hall effects and other related phenomena caused by the intrinsic spin–orbit interaction. We focus our attention on disorder effects on these transport properties by adopting a model of a two-dimensional electron gas with a Rashba-type spin–orbit interaction. A spin-polarized model is adopted to calculate the anomalous Hall effect and anisotropic magnetoresistance. It is shown that the spin Hall conductivity in the ballistic transport regime is cancelled by the so-called vertex corrections for the disorder scattering, and that the anomalous Hall conductivity and anisotropic magnetoresistance vanish unless the lifetime is spin dependent. We further present results on spin accumulation under an electric field
Dual Mode Low Power Hall Thruster, Phase I
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...
Suitable reverberation time for halls for rock and pop music
DEFF Research Database (Denmark)
Adelman-Larsen, Niels Werner; Thompson, Eric Robert; Gade, Anders Christian
2010-01-01
The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark....... 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 m3. 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....
Analysis of Hall Probe Precise Positioning with Cylindrical Permanent Magnet
International Nuclear Information System (INIS)
Belicev, P.; Vorozhtsov, A.S.; Vorozhtsov, S.B.
2007-01-01
Precise positioning of a Hall probe for cyclotron magnetic field mapping, using cylindrical permanent magnets, was analyzed. The necessary permanent magnet parameters in order to achieve ±20 μm position precision, were determined. (author)
High Input Voltage Hall Thruster Discharge Converter, Phase I
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...
Pragmatic data fusion uncertainty concerns: Tribute to Dave L. Hall
CSIR Research Space (South Africa)
Blasch, E
2016-07-01
Full Text Available Over the course of Dave Hall's career, he highlighted various concerns associated with the implementation of data fusion methods. Many of the issues included the role of uncertainty in data fusion, practical implementation of sensor fusion systems...
2D Electrostatic Potential Solver for Hall Thruster Simulation
National Research Council Canada - National Science Library
Koo, Justin W
2006-01-01
...) for Hall thruster simulation. It is based on a finite volume discretization of a current conservation equation where the electron current density is described by a Generalized Ohm's law description...
Precision of single-engage micro Hall effect measurements
DEFF Research Database (Denmark)
Henrichsen, Henrik Hartmann; Hansen, Ole; Kjær, Daniel
2014-01-01
Recently a novel microscale Hall effect measurement technique has been developed to extract sheet resistance (RS), Hall sheet carrier density (NHS) and Hall mobility (μH) from collinear micro 4-point probe measurements in the vicinity of an insulating boundary [1]. The technique measures in less...... than a minute directly the local transport properties, which enables in-line production monitoring on scribe line test pads [2]. To increase measurement speed and reliability, a method in which 4-point measurements are performed using two different electrode pitches has been developed [3......]. 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...
The integer quantum hall effect revisited
Energy Technology Data Exchange (ETDEWEB)
Michalakis, Spyridon [Los Alamos National Laboratory; Hastings, Matthew [Q STATION, CALIFORNIA
2009-01-01
For T - L x L a finite subset of Z{sup 2}, let H{sub o} denote a Hamiltonian on T with periodic boundary conditions and finite range, finite strength intetactions and a unique ground state with a nonvanishing spectral gap. For S {element_of} T, let q{sub s} denote the charge at site s and assume that the total charge Q = {Sigma}{sub s {element_of} T} q{sub s} is conserved. Using the local charge operators q{sub s}, we introduce a boundary magnetic flux in the horizontal and vertical direction and allow the ground state to evolve quasiadiabatically around a square of size one magnetic flux, in flux space. At the end of the evolution we obtain a trivial Berry phase, which we compare, via a method reminiscent of Stokes Theorem. to the Berry phase obtained from an evolution around an exponentially small loop near the origin. As a result, we show, without any averaging assumption, that the Hall conductance is quantized in integer multiples of e{sup 2}/h up to exponentially small corrections of order e{sup -L/{zeta}}, where {zeta}, is a correlation length that depends only on the gap and the range and strength of the interactions.
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...
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.
Hall MHD reconnection in cometary magnetotail
International Nuclear Information System (INIS)
Jovanovic, Dusan; Shukla, Padma Kant; Morfill, Gregor
2005-01-01
The fine structure of cometary tails (swirls, loops and blobs) is studied in the framework of resistive magnetic reconnection without a guide field in a dusty plasma. For a high-beta plasma (β ∼ 1) consisting of electrons, ions, and immobile dust grains, a two-fluid description is used to study electromagnetic perturbations with the frequency below Ωi, propagating at an arbitrary angle, and including the effects of Hall current. A zero-order current associated with the anti-parallel magnetic configuration may exist even in the limit of zero plasma temperature in a dusty plasma due to a symmetry breaking between electrons and ions by dust grains that yields an E-vector x B-vector current. In the perturbed state, a new linear electromagnetic mode is found in dusty plasma which is evanescent below the Rao cut-off frequency and has the characteristic wavelength comparable to the ion skin depth, which enables the reconnection at short spatial scales. The role of the dust is found to be twofold, yielding a new mode outside of the current sheet and altering the continuity conditions at its edge by an inhomogeneous Doppler shift associated with the E-vector x B-vector current
Linear waves in a resistive plasma with Hall current
International Nuclear Information System (INIS)
Almaguer, J.A.
1992-01-01
Dispersion relations for the case of a magnetized plasma are determined taking into account the Hall current and a constant resistivity, η, in Ohm's law. It is found that the Hall effect is relevant only for parallel (to the equilibrium magnetic field) wave numbers in the case of uniform plasmas, giving place to a dispersive behavior. In particular, the cases of η→0 and small (nonzero) resistivity are discussed
Hall effect in the two-dimensional Luttinger liquid
International Nuclear Information System (INIS)
Anderson, P.W.
1991-01-01
The temperature dependence of the Hall effect in the normal state is a commom theme of all the cuprate superconductors and has been one of the more puzzling observations on these puzzling materials. We describe a general scheme within the Luttinger liquid theory of these two-dimensional quantum fluids which corrrelates the anomalous Hall and resistivity observations on a wide variety of both pure and doped single crystals, especially the data in the accompanying Letter of Chien, Wang, and Ong
Thermoelectric and Hall-effect studies in hydrogenerated nickel foils
International Nuclear Information System (INIS)
Rani, R.; Nigam, A.N.
1978-01-01
Thermo e.m.f. and Hall constant of hydrogenerated nickel foils have been measured. Termo e.m.f. shows a sign reversal which is not due to the change in sign of the charge carriers, as indicated by the Hall-effect measurements. To account for the sign reversal of thermo e.m.f., it is found necessary to take into account the surface states of chemisorbed hydrogen on nickel
Fractional statistics and fractional quantized Hall effect. Revision
International Nuclear Information System (INIS)
Tao, R.; Wu, Y.S.
1984-01-01
We suggest that the origin of the odd denominator rule observed in the fractional quantized Hall effect (FQHE) may lie in fractional statistics which governs quasiparticles in FQHE. A theorem concerning statistics of clusters of quasiparticles implies that fractional statistics does not allow coexistence of a large number of quasiparticles at fillings with an even denominator. Thus no Hall plateau can be formed at these fillings, regardless of the presence of an energy gap. 15 references
Hall probe for measuring high currents in superconducting coils
International Nuclear Information System (INIS)
Ferendeci, A.M.
1986-01-01
Constructional details of a compact Hall probe for measuring high currents in superconducting coils are given. The Hall probe is easy to assemble and can be inserted or removed from the system without breaking the superconducting loop. Upper current limit of the probe can be increased by using larger magnetic core material. Shielding becomes necessary if the probe holder is to be placed near large current dependent magnetic fields
Low-Cost, High-Performance Hall Thruster Support System
Hesterman, Bryce
2015-01-01
Colorado Power Electronics (CPE) has built an innovative modular PPU for Hall thrusters, including discharge, magnet, heater and keeper supplies, and an interface module. This high-performance PPU offers resonant circuit topologies, magnetics design, modularity, and a stable and sustained operation during severe Hall effect thruster current oscillations. Laboratory testing has demonstrated discharge module efficiency of 96 percent, which is considerably higher than current state of the art.
High-performance LED luminaire for sports hall
Lee, Xuan-Hao; Yang, Jin-Tsung; Chien, Wei-Ting; Chang, Jung-Hsuan; Lo, Yi-Chien; Lin, Che-Chu; Sun, Ching-Cherng
2015-09-01
In this paper, we present a luminaire design with anti-glare and energy-saving effects for sports hall. Compared with traditional lamps using in a badminton court, the average illuminance on the ground of the proposed LED luminaire is enhanced about 300%. Besides, the uniformity is obviously enhanced and improved. The switch-on speed of lighting in sports hall is greatly reduced from 5-10 minutes to 1 second. The simulation analysis and the corresponding experiment results are demonstrated.
Brazilian union actions for workers' health protection
Directory of Open Access Journals (Sweden)
Rodolpho Repullo Junior
Full Text Available CONTEXT: Many authors have emphasized the importance of worker strength through unionized organizations, in relation to the improvement of working procedures, and have reported on the decisiveness of labor movement actions in achieving modifications within the field of work and health. OBJECTIVE: To describe the ways in which Brazilian unions have tried to intervene in health-illness and work processes, identifying the existence of commonality in union actions in this field. TYPE OF STUDY: Qualitative study. SETTING: Postgraduate Program, Environmental Health Department, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil. METHODS: Union health advisers and directors were interviewed. Documents relating to union action towards protecting workers' health were collected and analyzed. RESULTS: Unions articulate actions regarding workers' health of a technical and political nature that involve many aspects and high complexity. These have been divided into thematic categories for better analysis. DISCUSSION: Union actions regarding workers' health in Brazil are restricted to some unions, located mainly in the southern, southeastern and northeastern regions of the country. Nonetheless, the unions undertaking such actions represent many professions of great economic and political importance. CONCLUSIONS: The recent changes in health and safety at work regulations, recognition of professional diseases, creation of workers' health services and programs within the unified health system, and operational improvements in companies' specialized safety and occupational medicine services, all basically result from union action. There is commonality of union action in this field in its seeking of technical and political strengthening for all workers and their general and local representation. This has the objective of benefiting collective bargaining between employers and workers. Inter-institutional action on behalf of workers' rights
Anisotropic intrinsic spin Hall effect in quantum wires
International Nuclear Information System (INIS)
Cummings, A W; Akis, R; Ferry, D K
2011-01-01
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 [1-bar 10] 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. (paper)
The quantum Hall's effect: A quantum electrodynamic phenomenon
International Nuclear Information System (INIS)
Arbab, A. I.
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, V H = 2πħ 2 n s /em, where n s is the electron number density, for a 2-dimensional system, and h = 2πħ 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 L H = 2π m/e 2 n s and C H = me 2 /2πħ 2 n s satisfying the resonance condition with resonant frequency equal to the inverse of the scattering (relaxation) time, τ s . The Hall's resistance is found to be R H = √L H /C H . The Hall's resistance may be connected with the impedance that the electron wave experiences when it propagates in the 2-dimensional gas. (condensed matter: electronic structure, electrical, magnetic, and optical properties)
Signatures of lattice geometry in quantum and topological Hall effect
International Nuclear Information System (INIS)
Göbel, Börge; Mook, Alexander; Mertig, Ingrid; Henk, Jürgen
2017-01-01
The topological Hall effect (THE) of electrons in skyrmion crystals (SkXs) is strongly related to the quantum Hall effect (QHE) on lattices. This relation suggests to revisit the QHE because its Hall conductivity can be unconventionally quantized. It exhibits a jump and changes sign abruptly if the Fermi level crosses a van Hove singularity. In this Paper, we investigate the unconventional QHE features by discussing band structures, Hall conductivities, and topological edge states for square and triangular lattices; their origin are Chern numbers of bands in the SkX (THE) or of the corresponding Landau levels (QHE). Striking features in the energy dependence of the Hall conductivities are traced back to the band structure without magnetic field whose properties are dictated by the lattice geometry. Based on these findings, we derive an approximation that allows us to determine the energy dependence of the topological Hall conductivity on any two-dimensional lattice. The validity of this approximation is proven for the honeycomb lattice. We conclude that SkXs lend themselves for experiments to validate our findings for the THE and—indirectly—the QHE. (paper)
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).
A holographic model for the fractional quantum Hall effect
Energy Technology Data Exchange (ETDEWEB)
Lippert, Matthew [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, 1090GL Amsterdam (Netherlands); Meyer, René [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo,Kashiwa, Chiba 277-8568 (Japan); Taliotis, Anastasios [Theoretische Natuurkunde, Vrije Universiteit Brussel andThe International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2015-01-08
Experimental data for fractional quantum Hall systems can to a large extent be explained by assuming the existence of a Γ{sub 0}(2) modular symmetry group commuting with the renormalization group flow and hence mapping different phases of two-dimensional electron gases into each other. Based on this insight, we construct a phenomenological holographic model which captures many features of the fractional quantum Hall effect. Using an SL(2,ℤ)-invariant Einstein-Maxwell-axio-dilaton theory capturing the important modular transformation properties of quantum Hall physics, we find dyonic diatonic black hole solutions which are gapped and have a Hall conductivity equal to the filling fraction, as expected for quantum Hall states. We also provide several technical results on the general behavior of the gauge field fluctuations around these dyonic dilatonic black hole solutions: we specify a sufficient criterion for IR normalizability of the fluctuations, demonstrate the preservation of the gap under the SL(2,ℤ) action, and prove that the singularity of the fluctuation problem in the presence of a magnetic field is an accessory singularity. We finish with a preliminary investigation of the possible IR scaling solutions of our model and some speculations on how they could be important for the observed universality of quantum Hall transitions.
A holographic model for the fractional quantum Hall effect
Lippert, Matthew; Meyer, René; Taliotis, Anastasios
2015-01-01
Experimental data for fractional quantum Hall systems can to a large extent be explained by assuming the existence of a Γ0(2) modular symmetry group commuting with the renormalization group flow and hence mapping different phases of two-dimensional electron gases into each other. Based on this insight, we construct a phenomenological holographic model which captures many features of the fractional quantum Hall effect. Using an -invariant Einstein-Maxwell-axio-dilaton theory capturing the important modular transformation properties of quantum Hall physics, we find dyonic diatonic black hole solutions which are gapped and have a Hall conductivity equal to the filling fraction, as expected for quantum Hall states. We also provide several technical results on the general behavior of the gauge field fluctuations around these dyonic dilatonic black hole solutions: we specify a sufficient criterion for IR normalizability of the fluctuations, demonstrate the preservation of the gap under the action, and prove that the singularity of the fluctuation problem in the presence of a magnetic field is an accessory singularity. We finish with a preliminary investigation of the possible IR scaling solutions of our model and some speculations on how they could be important for the observed universality of quantum Hall transitions.
Denmark and the European Union
DEFF Research Database (Denmark)
Manners, Ian
2011-01-01
Over the past two decades Morten Kelstrup’s work has been at the centre of three important intellectual innovations in political science – the study of the EU as a regional political system; European security studies; and small states in European integration. Kelstrup’s best known books (Buzan, K...... of this book, two of Kelstrup’s most important intellectual contributions come from his work on Denmark’s relations with the European Union, and his use of systems theory to understand the EU.......Over the past two decades Morten Kelstrup’s work has been at the centre of three important intellectual innovations in political science – the study of the EU as a regional political system; European security studies; and small states in European integration. Kelstrup’s best known books (Buzan...
IDENTITY AND THE EUROPEAN UNION
Directory of Open Access Journals (Sweden)
Abrudan Cristina
2008-05-01
Full Text Available The purpose of this article is to throw some light on the question of identity in the European Union. The challenge is to understand how identity formation takes place in the contemporary world. The European integration has to be understood both as a process of socio-economic convergence among European states but also as a process of co-operation on different other levels, too. It seems that cultures, traditions and interests are more and more interconnected as societies become increasingly multicultural. This is the reason why people are concerned with the concept of identity and the recognition of their uniqueness in terms of traditions, values and ways of lives.
INNOVATION IN THE EUROPEAN UNION
Directory of Open Access Journals (Sweden)
VLADIMIR-CODRIN IONESCU
2014-11-01
Full Text Available In the contemporary knowledge-based society, innovation, as a vector used for the application and promotion of inventions and innovations, is one of the main sources used for obtaining a sustainable competitive advantage. The present paper points out the main directions which the European Commission aims to develop in the sphere of innovation, within the context of the Initiative: “A Union of Innovation”, which is part of the Europe 2020 Strategy. The paper analyses the performances accomplished by the EU states in the area of innovation while developing an international perspective that may represent the starting point in identifying solutions whereby the EU could reduce the gaps that exist in relation to the main international competitors, i.e. South Korea, USA and Japan.
INNOVATION IN THE EUROPEAN UNION
Directory of Open Access Journals (Sweden)
Vladimir-Codrin IONESCU
2014-05-01
Full Text Available In the contemporary knowledge-based society, innovation, as a vector used for the application and promotion of inventions and innovations, is one of the main sources used for obtaining a sustainable competitive advantage. The present paper points out the main directions which the European Commission aims to develop in the sphere of innovation, within the context of the Initiative: “A Union of Innovation”, which is part of the Europe 2020 Strategy. The paper analyses the performances accomplished by the EU states in the area of innovation while developing an international perspective that may represent the starting point in identifying solutions whereby the EU could reduce the gaps that exist in relation to the main international competitors, i.e. South Korea, USA and Japan.
International Union of Radioecologists' activities
International Nuclear Information System (INIS)
Auerbach, S.I.
1983-01-01
The International Union of Radioecologists (I.U.R.) has maintained a vigorous program of activities in accordance with the goals of its charter. To meet these goals, the I.U.R. has sponsored a number of workshops, meetings, and other related activities aimed at improving our ability to understand and predict the consequences of release of radionuclides to the environment. These include: intercomparison and harmonization of methodologies and a continuous feedback between scientists engaged in mathematical modeling and those carrying out field studies. Specialized workshops dealing with problems in understanding transfer coefficients in the terrestrial environment are being held. In the marine environment, long-distance transport in sediments plays an important role for the spread of radioisotopes released from reprocessing plants (e.g., in the Eastern Atlantic, the Northland Baltic Sea). Representatives of the countries concerned (including from Northern Countries) will define conditions of information exchange, sampling (time, character of sediments), and modelisation
Teacher Union Legitimacy: Shifting the Moral Center for Member Engagement
Popiel, Kara
2013-01-01
This mixed-method case study explored teacher union members' beliefs about the teacher union and their reasons for being active or inactive in the union. Findings suggest that teacher unions have gained pragmatic and cognitive legitimacy (Chaison and Bigelow in Unions and legitimacy. Cornell University Press, Ithaca, NY, 2002), but that…
New Roles for the Trade Unions
DEFF Research Database (Denmark)
Hull Kristensen, Peer; Sø Rocha, Robson
2012-01-01
This article builds on lessons from Denmark and the Nordic area to offer a novel and comprehensive logic of action within the emerging political economy that may be used to assess the possible new roles that unions can take on. The authors argue that unions are capable of “civilizing” globalizati...
Bovine cysticercosis in the European Union
DEFF Research Database (Denmark)
Blagojevic, Bojan; Robertson, Lucy J.; Vieira-Pinto, Madalena
2017-01-01
-only inspection of slaughtered cattle in order to reduce the potential for cross-contamination with bacteria that are of greatest public health risk, is expected in the European Union in the near future. With this system, the detection sensitivity for bovine cysticercosis that is already low with the current meat...... of bovine cysticercosis in the European Union....
Environment in the European Union 1995
DEFF Research Database (Denmark)
The update to the 1992 report on the state of the environment in the European Union requested by the European Commission......The update to the 1992 report on the state of the environment in the European Union requested by the European Commission...
Union innovation in Ontario's nuclear industry
International Nuclear Information System (INIS)
MacKinnon, D.
2003-01-01
Over the last decade the Power Worker's Union (PWU) has embarked on a number of innovative approaches that have provided significant benefit to the nuclear industry. These include advanced labour relations approaches, equity participation and groundbreaking skills training initiatives. This presentation outlines these and other initiatives in the context of the union's view of the nuclear generation industry's future. (author)
LIMITING ORGANISATIONAL RIGHTS OF MINORITY UNIONS ...
African Journals Online (AJOL)
Administrator
1996-02-19
Feb 19, 1996 ... market in recent times can be attributed, in part, to inter-union rivalry.1 Minority unions ... March 2013 – resulting in a negative impact on South Africa's GDP and currency depreciation. In. 2013, the .... Organisational rights are regulated by Part A and B of Chapter 111 of the LRA, and the right to strike is ...
Banking Union- Present Stage and its Perspectives
Directory of Open Access Journals (Sweden)
Petre Prisecaru
2014-05-01
Full Text Available Banking Union is very important for financial stability of EU, for preventing any future crisis, for improving corporate governance in the banking sector, for completing the single market for financial services and for the strengthening of monetary union, for opening the way to fiscal union and to political union. There is not enough theoretical research in the field of banking union, but there are many recent contributions on behalf of foreign and Romanian experts and analysts, which refer mainly to the three components/pillars of EU banking union: a Single Supervision Mechanism (SSM, a Single Resolution Mechanism (SRM and an harmonized system of deposit guarantee schemes. Some micro studies and surveys carried out by prestigious institutions, like Deutsche Bank, Brookings Institution, CEPS have been run over and analyzed together with the positions and opinions of different European officials, and also with the content of EU secondary legislation. An empirical research was made with the aim to identify all essential aspects relating to EU banking union, which may concern the academics, researchers and business community. The paper is based on a previous research study coordinated by author and contains his own conclusions focused on the main arguments in favour of banking union.
Should the 'Outs' Join the Banking Union?
P. Hüttl (Pia); D. Schoenmaker (Dirk)
2016-01-01
textabstractThe Single Market stimulates cross-border banking throughout the European Union. This paper documents the banking linkages between the 9 ‘outs’ and 19 ‘ins’ of the Banking Union. We find that some of the major banks, based in Sweden and Denmark, have substantial banking claims across the
76 FR 79531 - Corporate Credit Unions
2011-12-22
... exclude CLF stock subscriptions, based on the asset's negligible credit risk and to facilitate corporate... removing paragraphs (c)(3) and (f)(4) and adding paragraph (h) to read as follows: Sec. 704.6 Credit risk... NATIONAL CREDIT UNION ADMINISTRATION 12 CFR Part 704 RIN 3133-AD95 Corporate Credit Unions AGENCY...
The Defense of Teachers' Trade Union Rights.
Pepin, Luce
1990-01-01
The author sees cause for concern in the number of complaints to the International Labour Organisation alleging violations of teachers' union rights. She examines the right of public employees to organize and strike and government interference, concluding that greater protection for teachers' unions may be needed. (SK)
Immigration and the transformation of American unionism
Burgoon, B.; Fine, J.; Jacoby, W.; Tichenor, D.
2010-01-01
Does immigration hamper union organizing in the United States? The prevailing literature strongly suggests that it does and for two reasons: first, immigrants increase the labor pool and diminish union influence over the labor market. And second, immigrants may be harder to organize than native
The two union catalogues of Myanmar
Energy Technology Data Exchange (ETDEWEB)
Hla, Win [Myanmar Scientific and Technological Research Dept., Yangon (Myanmar)
1995-04-01
The article mentions about the two union catalogues of Myanmar. The first one is the ``Consolidated Catalogue of journals and the periodicals contained in the libraries of Kasuali, Calcutta, Bombay, Madras, Coonoor, Rangoon and Shillong``. This was published by Indian Research Fund Association of Calcutta in 1933. This is the first union catalogue of medical periodicals for both Myanmar and India as well. The second one is ``the Regional Union Catalogue of Scientific Serials: Yangon``. This was published in 1977, its second printing in 1989. This union catalogue excludes medical serials. Twenty libraries took part in the compilation and publishing of the union catalogue with Technical Information Centre of Myanmar Scientific and Technological Research Department, (formerly Central Research Organization), No. 6, Kaba Aye Pagoda Road, Yankin P.O. Yangon, Myanmar, taking the leading role.
Greece and the Missing Banking Union
DEFF Research Database (Denmark)
N. Gordon, Jeffery; Ringe, Georg
2015-01-01
The Greek Crisis is a crisis rather than a problem due to the vulnerability of Greek banks. While the banks have deep problems, this column argues that these would have been mitigated if a fully operational banking union were in place. A full banking union requires joint banking supervision, join...... bank resolution, and joint deposit insurance. The EZ only has the first so far. Completing the banking union must be part of any long-term solution.......The Greek Crisis is a crisis rather than a problem due to the vulnerability of Greek banks. While the banks have deep problems, this column argues that these would have been mitigated if a fully operational banking union were in place. A full banking union requires joint banking supervision, joint...
The two union catalogues of Myanmar
International Nuclear Information System (INIS)
Hla, Win
1995-01-01
The article mentions about the two union catalogues of Myanmar. The first one is the ''Consolidated Catalogue of journals and the periodicals contained in the libraries of Kasuali, Calcutta, Bombay, Madras, Coonoor, Rangoon and Shillong''. This was published by Indian Research Fund Association of Calcutta in 1933. This is the first union catalogue of medical periodicals for both Myanmar and India as well. The second one is ''the Regional Union Catalogue of Scientific Serials: Yangon''. This was published in 1977, its second printing in 1989. This union catalogue excludes medical serials. Twenty libraries took part in the compilation and publishing of the union catalogue with Technical Information Centre of Myanmar Scientific and Technological Research Department, (formerly Central Research Organization), No. 6, Kaba Aye Pagoda Road, Yankin P.O. Yangon, Myanmar, taking the leading role
The european union as subjects of law
Directory of Open Access Journals (Sweden)
Fila R.
2012-10-01
Full Text Available At the international level it is recognized that development and progress of the new and unique international organization – European Union – is one of the appropriate form of the international organization’s integration. Although European Union was establish as international economic organization, it has gradually integrated the various “best practices” ideas from different governmental systems. Encouragement and motives for cooperation of Member states indicate that member states give more competences of government to the international organization’s institutes. Wherewith, it is observed that the economic and political internationalization has led to disappearance of integrity of territory of member states. The above mentioned opinion is not based on research of the European Union as international organization from standpoint of international law, but from standpoint of theory law – could give juridical estimate regarding executive power in European Union and who could define particular source and entity of administrative law of European Union.
CFC legislation in the European Union
Directory of Open Access Journals (Sweden)
Cvjetković Cvjetana M.
2015-01-01
Full Text Available In this paper the author considers CFC legislation in the Member States of the European Union, and points to the official attitude of the institutions of the European Union toward CFC legislation. Special attention in this paper is focused on Judgment of the Court of Justice of the European Union in the case Cadbury Schweppes. The aim of the paper is to analyze CFC legislation in the Member States in order to determine its basic characteristics, as well as to determine its compatibility with freedoms guaranteed by the primary law of the European Union, i.e. with Judgment of the Court of Justice of the European Union in the Cadbury Schweppes case.
Vocational Training in the European Union
Directory of Open Access Journals (Sweden)
Mehmet BALCI
2013-01-01
Full Text Available European Union requires some standards in all areas. Today, the importance of training qualified individuals which holds an important place in the development of countries increases and certain standards are adopted creating common European Union tools in the field of vocational and technical education. In this study, vocational education and training policies system and the standards adopted by the European Union are discussed. Furthermore, this study was accepted as a European Union project in 2010 and the results obtained from the Leonardo Da Vinci Life Learning European Union project called “Web Based Basic Vocational Training” between the years 2010-2012 were presented. Since the partners of these projects are Turkey, Spain and Germany, the structure of vocational education, institutions of public and private vocational education and the diplomas and certificates entitled after these educations are included. As Turkey is on its way to become a European Union member, a number of advices are presented for Turkey to reach its destination about vocational education standards that European Union has aimed. The purpose of the study is not only to be a guide for the young who want to get professional training in the countries that are European Union members or candidates about how and where to have education opportunities but also to give a chance for trainers and training managers, participating in vocational training, so as to glimpse different practices from different countries and compare these practices between the countries of European Union and their countries. The study is also very important as it has the opportunities for training managers to see if their countries' vocational education is close enough to vocational education in European Union.
DISK FORMATION IN MAGNETIZED CLOUDS ENABLED BY THE HALL EFFECT
International Nuclear Information System (INIS)
Krasnopolsky, Ruben; Shang, Hsien; Li Zhiyun
2011-01-01
Stars form in dense cores of molecular clouds that are observed to be significantly magnetized. A dynamically important magnetic field presents a significant obstacle to the formation of protostellar disks. Recent studies have shown that magnetic braking is strong enough to suppress the formation of rotationally supported disks in the ideal MHD limit. Whether non-ideal MHD effects can enable disk formation remains unsettled. We carry out a first study on how disk formation in magnetic clouds is modified by the Hall effect, the least explored of the three non-ideal MHD effects in star formation (the other two being ambipolar diffusion and Ohmic dissipation). For illustrative purposes, we consider a simplified problem of a non-self-gravitating, magnetized envelope collapsing onto a central protostar of fixed mass. We find that the Hall effect can spin up the inner part of the collapsing flow to Keplerian speed, producing a rotationally supported disk. The disk is generated through a Hall-induced magnetic torque. Disk formation occurs even when the envelope is initially non-rotating, provided that the Hall coefficient is large enough. When the magnetic field orientation is flipped, the direction of disk rotation is reversed as well. The implication is that the Hall effect can in principle produce both regularly rotating and counter-rotating disks around protostars. The Hall coefficient expected in dense cores is about one order of magnitude smaller than that needed for efficient spin-up in these models. We conclude that the Hall effect is an important factor to consider in studying the angular momentum evolution of magnetized star formation in general and disk formation in particular.
Discerning The Motivational Basis For Trade Unionism In Public And ...
African Journals Online (AJOL)
Discerning The Motivational Basis For Trade Unionism In Public And Private ... private businesses are very clear to the actors of industrial relations; those of their ... selfish interests; unions in the public sector ought to function as uplift unions, ...
IMPORTANCE OF THE EUROPEAN BANKING UNION NEW DIRECTIVES
MEDAR LUCIAN-ION; Irina-Elena Chirtoc
2014-01-01
European Banking Union has set new rules on monetary market especially for credit institutions and for financial banking groups in general. Economic and monetary union requires accomplishment of political and monetary union and democratic control of the European institutions on a single financial market. In this respect through its management organisms, EU has designed a series of unique mechanisms of financial union and called for a fiscal union. Union of European financial marke...
Acquired Credit Unions: Drivers of Takeover
Directory of Open Access Journals (Sweden)
R. Raymond Sant
2015-08-01
Full Text Available In this paper we study acquired credit unions and analyze their financial performance up to six years prior to merger, on a quarterly basis. The primary focus is on balance sheet (asset liability management and profitability variables (return on assets. We find that acquired credit unions during the period 2008 (third quarter to 2014 (first quarter experienced negative return on assets for several quarters prior to their takeover. This was the result of a declining loan portfolio and increasing charge offs. In spite of decreasing lending activity, such credit unions continued to increase their deposits, i.e., adding to their cost base. Due to declining loans, their net interest margin as a proportion of deposits was also in decline. We argue that this is an indicator of poor management ability. Furthermore, our analysis finds that operating expenses were increasing over time, something that has been documented in previous literature also for smaller credit unions and is attributable to lack of economies of scale. The average asset size of the acquired credit unions in our sample is about $22 million just before acquisition. We attribute our findings to poor business strategy followed by such credit unions. We also conclude that signs of trouble are evident up to two years before merger on average and regulatory policy may have to become more proactive to manage the consolidation challenge faced by the credit union industry in general.
Church unions and their consequences in Poland
Directory of Open Access Journals (Sweden)
Antoni Mironowicz
2014-11-01
Full Text Available Orthodox Christians in Poland have faced numerous attempts to be forced into union with the Roman Catholic Church, ranging from the thirteenth to the twentieth century. The first attempt at a union between the Roman Catholic Church and the Orthodox Church took place as early as the mid-thirteenth century. Another attempt at forcing the Orthodox Church into union with Rome took place during the reign of Ladislaŭ II Yagiello. The problem of church union returned in the reign of Alexander the Yagiellonian. When Ivan III rejected all projects for bringing the Florence such a union into practice, discussion on church union disappeared until the end of the sixteenth century. The mission of the papal legate, Father Antonio Possevino, to Ivan IV, had been intended to draw Moscow into the union, and its failure caused the papacy to concentrate its efforts on the Orthodox Church in Poland. The Ruthenian bishops’ obedience to the Pope was officially announced on the 8 October 1596. The decisions of the Uniate-Catholic synod were met with numerous protests from the Orthodox clergy and nobility. The larger part of the clergy and the faithful, together with bishops remained in the Orthodox camp. Despite the failure of the Brest Synod in fully uniting Orthodox and Roman churches, new union projects concerning the Orthodox Church in Poland continued to arise prior to the end of 18th century. The Vatican’s interest in the Orthodox Church in Central Europe was renewed at the end of the First World War. On April 1st, 1917, the Pope created the Congregation for the Oriental Churches which was responsibile for all issues relating to the activities of all the Eastern denominations. Despite aims at unification, attempts at church union have had a negative influence on the relations between the Roman Catholic and Polish Orthodox Church in contemporary Poland. The result of centuries of attempts at unification under the Pope has been fragmentation and division.
Hamaoka Atomic Energy Hall, Chubu Electric Power Co. , Inc
Energy Technology Data Exchange (ETDEWEB)
Kawasaki, Y [Chubu Electric Power Co. Inc., Nagoya (Japan)
1979-10-01
Hamaoka Nuclear Power Station was constructed in the very large site of about 1.6 million m/sup 2/ surrounded by sand dunes and pine forests at the southern tip of Shizuoka Prefecture. Hamaoka Atomic Energy Hall was built on the right side of this power station. This hall had been planned as a part of the works commemorating the 20th anniversary of the founding of the company, and was opened in August, 1972. The building is of steel frame type, and has two floors of 1135 m/sup 2/ total area. The first floor comprises cinema room, power generation corner and open gallery, and the second floor comprises meeting room, native land corner and observation room. Moreover, there is observation platform on the roof. The purpose of the hall is coexistence and coprosperity with the regional residents, and 13 persons make explanations to visitors having reached to 1.9 million as of the end of June, 1979. It is incorporated in the sightseeing route centering around the Omaezaki lighthouse. The cinema hall accommodates 120 men, and the films concerning nuclear power generation and the construction of a nuclear power plant are shown. In the power generation corner, the explanation on nuclear power generation is made with models and panels. The third hall is being built now as energy corner, and it will be completed in autumn, 1979.
Hamaoka Atomic Energy Hall, Chubu Electric Power Co., Inc
International Nuclear Information System (INIS)
Kawasaki, Yukio
1979-01-01
Hamaoka Nuclear Power Station was constructed in the very large site of about 1.6 million m 2 surrounded by sand dunes and pine forests at the southern tip of Shizuoka Prefecture. Hamaoka Atomic Energy Hall was built on the right side of this power station. This hall had been planned as a part of the works commemorating the 20th anniversary of the founding of the company, and was opened in August, 1972. The building is of steel frame type, and has two floors of 1135 m 2 total area. The first floor comprises cinema room, power generation corner and open gallery, and the second floor comprises meeting room, native land corner and observation room. Moreover, there is observation platform on the roof. The purpose of the hall is coexistence and coprosperity with the regional residents, and 13 persons make explanations to visitors having reached to 1.9 million as of the end of June, 1979. It is incorporated in the sightseeing route centering around the Omaezaki lighthouse. The cinema hall accommodates 120 men, and the films concerning nuclear power generation and the construction of a nuclear power plant are shown. In the power generation corner, the explanation on nuclear power generation is made with models and panels. The third hall is being built now as energy corner, and it will be completed in autumn, 1979. (Kako, I.)
Higher (odd dimensional quantum Hall effect and extended dimensional hierarchy
Directory of Open Access Journals (Sweden)
Kazuki Hasebe
2017-07-01
Full Text Available We demonstrate dimensional ladder of higher dimensional quantum Hall effects by exploiting quantum Hall effects on arbitrary odd dimensional spheres. Non-relativistic and relativistic Landau models are analyzed on S2k−1 in the SO(2k−1 monopole background. The total sub-band degeneracy of the odd dimensional lowest Landau level is shown to be equal to the winding number from the base-manifold S2k−1 to the one-dimension higher SO(2k gauge group. Based on the chiral Hopf maps, we clarify the underlying quantum Nambu geometry for odd dimensional quantum Hall effect and the resulting quantum geometry is naturally embedded also in one-dimension higher quantum geometry. An origin of such dimensional ladder connecting even and odd dimensional quantum Hall effects is illuminated from a viewpoint of the spectral flow of Atiyah–Patodi–Singer index theorem in differential topology. We also present a BF topological field theory as an effective field theory in which membranes with different dimensions undergo non-trivial linking in odd dimensional space. Finally, an extended version of the dimensional hierarchy for higher dimensional quantum Hall liquids is proposed, and its relationship to quantum anomaly and D-brane physics is discussed.
G. Stanley Hall, Child Study, and the American Public.
Young, Jacy L
2016-01-01
In the final decades of the 19th century psychologist Granville Stanley Hall was among the most prominent pedagogical experts in the nation. The author explores Hall's carefully crafted persona as an educational expert, and his engagements with the American public, from 1880 to 1900, arguably the height of his influence. Drawing from accounts of Hall's lecture circuit in the popular press, a map of his talks across the nation is constructed to assess the geographic scope of his influence. These talks to educators on the psychology underlying childhood and pedagogy, and his views and research on child life more generally, were regularly discussed in newspapers and popular periodicals. The venues in which Hall's ideas were disseminated, discussed, and in some cases, dismissed are described. His efforts to mobilize popular support for, and assistance with, his research endeavors in child study are also discussed. Such efforts were controversial both within the burgeoning field of psychology and among the public. Through his various involvements in pedagogy, and concerted efforts to engage with the American public, Hall helped establish psychology's relevance to parenting and educational practices.
Seville City Hall Chapter Room ceiling decoration
Directory of Open Access Journals (Sweden)
Robador, M. D.
2010-02-01
Full Text Available The present article describes a chemical and physical study of the colour, chemical composition and mineral phases of the decorative materials in the Seville City Hall Chapter House ceiling. The findings showed that the inner most layer of material, calcite, was covered with white lead, in turn concealed under a layer of gilded bole. The ceiling underwent re-gilding, also over bole, due in all likelihood to wear on the original gold leaf. In the nineteenth century, the entire ceiling with the exception of the inscriptions was whitewashed with calcite and white lead. Silver was employed on King John I’s sword (coffer 27. Gold leaf was used to adorn the royal attributes: crowns, belts, sceptres, swords and rosary beads. The high reliefs were likewise gilded. The pigments identified on the ceiling adornments included azurite, malachite, vermilion and gas black. A lime and ground dolomite mortar was used throughout.
El objetivo de este trabajo es el estudio de diferentes aspectos, como el color, la composición química y las fases mineralógicas presentes en los diferentes materiales que forman la ornamentación del techo de la Sala Capitular del Ayuntamiento de Sevilla, mediante métodos físicos y químicos. Nuestros resultados muestran que el dorado fue realizado sobre una capa de bol previamente depositada sobre una lámina de blanco de plomo que cubría un estrato de calcita. Posteriormente, y probablemente debido a alteraciones en el dorado original, el techo fue de nuevo dorado usando una técnica similar. En el siglo XIX, casi todo el techo, excepto las zonas con inscripciones, fue blanqueado usando una mezcla de calcita y blanco de plomo. Se empleó plata para cubrir la espada del rey Juan I (casetón 27. Finísimas láminas de oro se usaron para decorar los atributos reales: coronas, cinturones, cetros, espadas y rosarios. En diferentes partes de la decoración fueron detectados pigmentos como azurita, malaquita, bermellón y
Green Capital: Student Capital student-led evaluation
Runkle, Q.; Haines, T.; Piper, K.; Leach, S.
2016-01-01
To assess and evaluate the impact of the Green Capital: Student Capital project, the partnership (the University of the West of England, the University of Bristol, the Students’ Union at UWE, and Bristol Students’ Union) worked with NUS to train a team of students from both universities to lead an evaluation process. There were two key aims for the evaluation: \\ud \\ud • To verify the quantitative outputs of the Green Capital: Student Capital project; \\ud • And to make a qualitative assessment...
The European Union in International Financial Governance
Directory of Open Access Journals (Sweden)
Niamh Moloney
2017-01-01
Full Text Available This article considers the role of the European Union in international financial governance after the institutional reforms it undertook in connection with the global financial crisis. It suggests that the new administrative actors that support the governance of the European Union's single financial market, notably the European Supervisory Authorities, have the potential to reshape how the European Union engages with international financial governance. It finds that the European Union’s effectiveness in influencing international financial governance—and the effectiveness of international financial governance more generally—is likely to strengthen as a result.
Trends in preference, programming and design of concert halls for symphonic music
DEFF Research Database (Denmark)
Gade, Anders Christian
2008-01-01
This paper discusses the evolution in taste regarding concert hall acoustics and how this can be reflected in the new halls being built today. The clients' and listener's preferences are not only based on listening in existing halls; but also on listening to reproduced music recorded with microph......This paper discusses the evolution in taste regarding concert hall acoustics and how this can be reflected in the new halls being built today. The clients' and listener's preferences are not only based on listening in existing halls; but also on listening to reproduced music recorded...
Modular invariance, universality and crossover in the quantum Hall effect
International Nuclear Information System (INIS)
Dolan, Brian P.
1999-01-01
An analytic form for the conductivity tensor in crossover between two quantum Hall plateaux is derived, which appears to be in good agreement with existing experimental data. The derivation relies on an assumed symmetry between quantum Hall states, a generalisation of the law of corresponding states from rational filling factors to complex conductivity, which has a mathematical expression in terms of an action of the modular group on the upper-half complex conductivity plane. This symmetry implies universality in quantum Hall crossovers. The assumption that the β-function for the complex conductivity is a complex analytic function, together with some experimental constraints, results in an analytic expression for the crossover, as a function of the external magnetic field
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.
Admittance of multiterminal quantum Hall conductors at kilohertz frequencies
International Nuclear Information System (INIS)
Hernández, C.; Consejo, C.; Chaubet, C.; Degiovanni, P.
2014-01-01
We present an experimental study of the low frequency admittance of quantum Hall conductors in the [100 Hz, 1 MHz] frequency range. We show that the frequency dependence of the admittance of the sample strongly depends on the topology of the contacts connections. Our experimental results are well explained within the Christen and Büttiker approach for finite frequency transport in quantum Hall edge channels taking into account the influence of the coaxial cables capacitance. In the Hall bar geometry, we demonstrate that there exists a configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the sample and observe its dependence on the filling factor
Admittance of multiterminal quantum Hall conductors at kilohertz frequencies
Energy Technology Data Exchange (ETDEWEB)
Hernández, C. [Departamento de Física, Universidad Militar Nueva Granada, Carrera 11 101-80 Bogotá D.C. (Colombia); Consejo, C.; Chaubet, C., E-mail: christophe.chaubet@univ-montp2.fr [Université Montpellier 2, Laboratoire Charles Coulomb UMR5221, F-34095 Montpellier, France and CNRS, Laboratoire Charles Coulomb UMR5221, F-34095 Montpellier (France); Degiovanni, P. [Université de Lyon, Fédération de Physique Andrée Marie Ampère, CNRS, Laboratoire de Physique de l' Ecole Normale Supérieure de Lyon, 46 allée d' Italie, 69364 Lyon Cedex 07 (France)
2014-03-28
We present an experimental study of the low frequency admittance of quantum Hall conductors in the [100 Hz, 1 MHz] frequency range. We show that the frequency dependence of the admittance of the sample strongly depends on the topology of the contacts connections. Our experimental results are well explained within the Christen and Büttiker approach for finite frequency transport in quantum Hall edge channels taking into account the influence of the coaxial cables capacitance. In the Hall bar geometry, we demonstrate that there exists a configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the sample and observe its dependence on the filling factor.
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.
The quantum Hall effect in quantum dot systems
International Nuclear Information System (INIS)
Beltukov, Y M; Greshnov, A A
2014-01-01
It is proposed to use quantum dots in order to increase the temperatures suitable for observation of the integer quantum Hall effect. A simple estimation using Fock-Darwin spectrum of a quantum dot shows that good part of carriers localized in quantum dots generate the intervals of plateaus robust against elevated temperatures. Numerical calculations employing local trigonometric basis and highly efficient kernel polynomial method adopted for computing the Hall conductivity reveal that quantum dots may enhance peak temperature for the effect by an order of magnitude, possibly above 77 K. Requirements to potentials, quality and arrangement of the quantum dots essential for practical realization of such enhancement are indicated. Comparison of our theoretical results with the quantum Hall measurements in InAs quantum dot systems from two experimental groups is also given
Diaphragm Effect of Steel Space Roof Systems in Hall Structures
Directory of Open Access Journals (Sweden)
Mehmet FENKLİ
2015-09-01
Full Text Available Hall structures have been used widely for different purposes. They have are reinforced concrete frames and shear wall with steel space roof systems. Earthquake response of hall structures is different from building type structures. One of the most critical nodes is diaphragm effect of steel space roof on earthquake response of hall structures. Diaphragm effect is depending on lateral stiffness capacity of steel space roof system. Lateral stiffness of steel space roof system is related to modulation geometry, support conditions, selected sections and system geometry. In current paper, three representative models which are commonly used in Turkey were taken in to account for investigation. Results of numerical tests were present comparatively
Novel Hall sensors developed for magnetic field imaging systems
International Nuclear Information System (INIS)
Cambel, Vladimir; Karapetrov, Goran; Novosad, Valentyn; Bartolome, Elena; Gregusova, Dagmar; Fedor, Jan; Kudela, Robert; Soltys, Jan
2007-01-01
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
Crossover between spin swapping and Hall effect in disordered systems
Saidaoui, Hamed Ben Mohamed; Otani, Y.; Manchon, Aurelien
2015-01-01
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.
ε-iron nitrides: Intrinsic anomalous Hall ferromagnets
Directory of Open Access Journals (Sweden)
Guo-Ke Li
2015-02-01
Full Text Available The anomalous Hall effect in ε-iron nitrides (ε-Fe3-xN, 0 ≤ x ≤ 1 has been systematically investigated taking advantage of the fact that the exchange splitting of ε-Fe3-xN can be continuously tuned through the nitrogen concentration. It has been found that the anomalous Hall conductivity, σ x y A H , is proportional to the saturation magnetization MS, i.e., σ x y A H = S H M S , across significant variations in the saturation magnetization (96–1146 emu/cc. This relationship is in excellent agreement with the intrinsic mechanism as well as with the unified theory of AHE. Our results also demonstrate that the anomalous Hall conductivity is sensitive to the exchange splitting of the band structure.
Can ensemble condition in a hall be improved and measured?
DEFF Research Database (Denmark)
Gade, Anders Christian
1988-01-01
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......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...... 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...
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.
International Nuclear Information System (INIS)
Martin, L. N.; Dmitruk, P.; Gomez, D. O.
2010-01-01
In this work we numerically test a model of Hall magnetohydrodynamics in the presence of a strong mean magnetic field: the reduced Hall magnetohydrodynamic model (RHMHD) derived by [Gomez et al., Phys. Plasmas 15, 102303 (2008)] with the addition of weak compressible effects. The main advantage of this model lies in the reduction of computational cost. Nevertheless, up until now the degree of agreement with the original Hall MHD system and the range of validity in a regime of turbulence were not established. In this work direct numerical simulations of three-dimensional Hall MHD turbulence in the presence of a strong mean magnetic field are compared with simulations of the weak compressible RHMHD model. The results show that the degree of agreement is very high (when the different assumptions of RHMHD, such as spectral anisotropy, are satisfied). Nevertheless, when the initial conditions are isotropic but the mean magnetic field is maintained strong, the results differ at the beginning but asymptotically reach a good agreement at relatively short times. We also found evidence that the compressibility still plays a role in the dynamics of these systems, and the weak compressible RHMHD model is able to capture these effects. In conclusion the weak compressible RHMHD model is a valid approximation of the Hall MHD turbulence in the relevant physical context.
Trade Union Cooperation in the EU: Views Among Swedish Trade Unions and Their Members
Directory of Open Access Journals (Sweden)
Bengt Furåker
2013-09-01
Full Text Available This article compares views among Swedish trade unions with those of their members regarding cross-national union cooperation in Europe or the EU. Data are derived from two different surveys, one among trade unions in 2010–2011 and the other among employees in 2006. It turns out that trade unions are generally more affirmative than their members to transnational union cooperation. In the employee survey, differences appear between members of the three peak-level organizations—the LO (manual workers, the TCO (white-collar workers, and Saco (professionals. However, controlling for education, these differences cannot be verified statistically. Higher education—which above all Saco members have—is linked to more positive attitudes toward transnational union cooperation. The gap between the organizations and their affiliates concerning engagement in European issues appears to be larger in the LO than in Saco, with the TCO somewhere in the middle.
Children's Literature in the Soviet Union
Miller, D. D.; And Others
1976-01-01
Children's literature in the Soviet Union is of four types: 17 stories based on old tales, adaptations from great Russian literature, original writings for children, and translations from foreign works. (JH)
Former Soviet Union (FSU) Gravity Data
National Oceanic and Atmospheric Administration, Department of Commerce — Gridded gravity anomaly data for the Former Soviet Union (FSU) and Eastern Europe has been received by the National Geophysical Data Center(NGDC). The data file...
The public control of credit unions
Directory of Open Access Journals (Sweden)
Alberto García Müller
2006-12-01
Full Text Available Public control is the activity of investigation or review by the government takes over a company, to verify the conformity of its actions to law. This paper analyzes the control over credit unions.
Greiter, Martin
2011-01-01
This monograph introduces an exact model for a critical spin chain with arbitrary spin S, which includes the Haldane--Shastry model as the special case S=1/2. While spinons in the Haldane-Shastry model obey abelian half-fermi statistics, the spinons in the general model introduced here obey non-abelian statistics. This manifests itself through topological choices for the fractional momentum spacings. The general model is derived by mapping exact models of quantized Hall states onto spin chains. The book begins with pedagogical review of all the relevant models including the non-abelian statistics in the Pfaffian Hall state, and is understandable to every student with a graduate course in quantum mechanics.
Radioactive waste management in European Union countries
International Nuclear Information System (INIS)
Vico, E.
2002-01-01
Although the Euratom Treaty does not assign direct authorities to the European Union in the Field of radioactive waste, the Commission has developed a series of activities related to this type of waste. The article deals with these Community initiatives, and the problems of radioactive waste management in the different Member States, and future plans in the field in the light of forthcoming European Union enlargement in 2004. (Author)
Does union membership really reduce job satisfaction?
Alex Bryson; Lorenzo Cappellari; Claudio Lucifora
2003-01-01
We investigate the effect of union membership on job satisfaction. Whilst it is common to study the effects of union status on satisfaction treating individual membership as given, in this paper, we account for the endogenous selection induced by the sorting of workers into unionised jobs. Using linked employer-employee data from the 1998 British Workplace Employee Relations Survey, we address the question of how the membership decision is related to overall job satisfaction and to satisfacti...
Taxation of credit unions in Ukraine
Directory of Open Access Journals (Sweden)
Оксана Георгіївна Волкова
2015-10-01
Full Text Available The article deals with the issues of income taxation of credit unions in Ukraine by the tax on profits of enterprises and tax of revenues of their members accrued on the interest of contributions (deposits on deposit accounts and mutual funds the tax to incomes of physical persons. The consequences of the influence of tax rules on capitalization of unions and the level of their financial support is defined
Spin-Hall nano-oscillator: A micromagnetic study
Energy Technology Data Exchange (ETDEWEB)
Giordano, A.; Azzerboni, B.; Finocchio, G. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy); Carpentieri, M. [Department of Electrical and Information Engineering, Politecnico of Bari, via E. Orabona 4, I-70125 Bari (Italy); Laudani, A. [Department of Engineering, University of Roma Tre, via V. Volterra 62, I-00146 Roma (Italy); Gubbiotti, G. [Istituto Officina dei Materiali del CNR (CNR-IOM), Unità di Perugia c/o Dipartimento di Fisica e Geologia, Via A. Pascoli, 06123 Perugia (Italy)
2014-07-28
This Letter studies the dynamical behavior of spin-Hall nanoscillators from a micromagnetic point of view. The model parameters have been identified by reproducing recent experimental data quantitatively. Our results indicate that a strongly localized mode is observed for in-plane bias fields such as in the experiments, while predict the excitation of an asymmetric propagating mode for large enough out-of plane bias field similarly to what observed in spin-torque nanocontact oscillators. Our findings show that spin-Hall nanoscillators can find application as spin-wave emitters for magnonic applications where spin waves are used for transmission and processing information on nanoscale.
Complex scattering dynamics and the quantum Hall effects
International Nuclear Information System (INIS)
Trugman, S.A.
1994-01-01
We review both classical and quantum potential scattering in two dimensions in a magnetic field, with applications to the quantum Hall effect. Classical scattering is complex, due to the approach of scattering states to an infinite number of dynamically bound states. Quantum scattering follows the classical behavior rather closely, exhibiting sharp resonances in place of the classical bound states. Extended scatterers provide a quantitative explanation for the breakdown of the QHE at a comparatively small Hall voltage as seen by Kawaji et al., and possibly for noise effects
Impact of external conditions on energy consumption in industrial halls
Żabnieńśka-Góra, Alina
2017-11-01
The energy demand for heating the halls buildings is high. The impact on this may have the technology of production, building construction and technology requirements (HVAC systems). The isolation of the external partitions, the location of the object in relation to the surrounding buildings and the degree of the interior insolation (windows and skylights) are important in the context of energy consumption. The article discusses the impact of external conditions, wind and sunlight on energy demand in the industrial hall. The building model was prepared in IDA ICE 4.0 simulation software. Model validation was done based on measurements taken in the analyzed building.
Hall effects on MHD flow past an accelerated plate
Directory of Open Access Journals (Sweden)
Deka R.K.
2008-01-01
Full Text Available The simultaneous effects of rotation and Hall current on the hydromagnetic flow past an accelerated horizontal plate relative to a rotating fluid is presented. It is found that for given values of m (Hall parameter, M (Hartmann number and an imposed rotation parameter Ω satisfying Ω = M 2m/(1 + m2, the transverse motion (transverse to the main flow disappears and the fluid moves in the direction of the plate only. The effects of the parameters m, M and Ω on the axial and transverse velocity profiles are shown graphically, whereas the effects of the parameters on the skin-friction components are shown by tabular values.
Spectroscopy of snake states using a graphene Hall bar
Energy Technology Data Exchange (ETDEWEB)
Milovanović, S. P., E-mail: slavisa.milovanovic@gmail.com; Ramezani Masir, M., E-mail: mrmphys@gmail.com; Peeters, F. M., E-mail: francois.peeters@ua.ac.be [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)
2013-12-02
An approach to observe snake states in a graphene Hall bar containing a pn-junction is proposed. The magnetic field dependence of the bend resistance in a ballistic graphene Hall bar structure containing a tilted pn-junction oscillates as a function of applied magnetic field. We show that each oscillation is due to a specific snake state that moves along the pn-interface. Furthermore, depending on the value of the magnetic field and applied potential, we can control the lead in which the electrons will end up and hence control the response of the system.
Theory of spin Hall effect: extension of the Drude model.
Chudnovsky, Eugene M
2007-11-16
An extension of the Drude model is proposed that accounts for the spin and spin-orbit interaction of charge carriers. Spin currents appear due to the combined action of the external electric field, crystal field, and scattering of charge carriers. The expression for the spin Hall conductivity is derived for metals and semiconductors that is independent of the scattering mechanism. In cubic metals, the spin Hall conductivity sigma s and charge conductivity sigma c are related through sigma s=[2pi variant /(3mc2)]sigma2c with m being the bare electron mass. The theoretically computed value is in agreement with experiment.
Hall measurements and grain-size effects in polycrystalline silicon
International Nuclear Information System (INIS)
Ghosh, A.K.; Rose, A.; Maruska, H.P.; Eustace, D.J.; Feng, T.
1980-01-01
The effects of grain size on Hall measurements in polycrystalline silicon are analyzed and interpreted, with some modifications, using the model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge regions. For materials with large grain sizes, the carrier concentration is independent of the intergrain boundary barrier, whereas the mobility is dependent on it. However, for small grains, both the carrier density and mobility depend on the barrier. These predictions are consistent with experimental results of mm-size Wacker and μm-size neutron-transmutation-doped polycrystalline silicon
Fractional quantum Hall states of atoms in optical lattices
International Nuclear Information System (INIS)
Soerensen, Anders S.; Demler, Eugene; Lukin, Mikhail D.
2005-01-01
We describe a method to create fractional quantum Hall states of atoms confined in optical lattices. We show that the dynamics of the atoms in the lattice is analogous to the motion of a charged particle in a magnetic field if an oscillating quadrupole potential is applied together with a periodic modulation of the tunneling between lattice sites. In a suitable parameter regime the ground state in the lattice is of the fractional quantum Hall type, and we show how these states can be reached by melting a Mott-insulator state in a superlattice potential. Finally, we discuss techniques to observe these strongly correlated states
Theory of the quantized Hall effect. Pt. 3
International Nuclear Information System (INIS)
Levine, H.; Pruisken, A.M.M.; Libby, S.B.
1984-01-01
In the previous paper, we have demonstrated the need for a phase transition as a function of theta in the non-liner sigma-model describing the quantized Hall effect. In this work, we present arguments for the occurrence of exactly such a transition. We make use of a dilute gas instanton approximation as well as present a more rigorous duality argument to show that the usual scaling of the conductivity to zero at large distances is altered whenever sigmasub(xy)sup((0)) approx.= 1/2ne 2 /h, n integer. This then completes our theory of the quantized Hall effect. (orig.)
Complex dynamics of the integer quantum Hall effect
International Nuclear Information System (INIS)
Trugman, S.A.; Nicopoulos, V.N.; Florida Univ., Gainesville, FL
1991-01-01
We investigate both classical and quantum potential scattering in two dimensions in a magnetic field, with applications to the integer quantum Hall effect. Classical scattering is complex, due in one case to the approach of scattering states to an infinite number of bound states. We show that bound states are generic, and occur for all but extremely smooth scattering potentials (|rvec ∇| → 0). Quantum scattering follows the classical behavior rather closely, exhibiting sharp resonances rather than classical bound states. Extended scatterers provide an explanation for the breakdown of the QHE at a comparatively small Hall voltage. 16 refs., 14 figs
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.
Quantum hall fluid on fuzzy two dimensional sphere
International Nuclear Information System (INIS)
Luo Xudong; Peng Dantao
2004-01-01
After reviewing the Haldane's description about the quantum Hall effect on the fuzzy two-sphere S 2 , authors construct the noncommutative algebra on the fuzzy sphere S 2 and the Moyal structure of the Hilbert space. By constructing noncommutative Chern-Simons theory of the incompressible Hall fluid on the fuzzy sphere and solving the Gaussian constraint with quasiparticle source, authors find the Calogero matrix on S 2 and the complete set of the Laughlin wave function for the lowest Landau level, and this wave function is expressed by the generalized Jack polynomials in terms of spinor coordinates. (author)
Bingo halls and smoking: perspectives of First Nations women.
Bottorff, Joan L; Carey, Joanne; Mowatt, Roberta; Varcoe, Colleen; Johnson, Joy L; Hutchinson, Peter; Sullivan, Debbie; Williams, Wanda; Wardman, Dennis
2009-12-01
The purpose of this study was to examine bingo halls as a frequent site for exposure to secondhand cigarette smoke for First Nations women in rural communities. Thematic analysis of interviews with key informants, group discussions with young women, and observations in the study communities revealed that smoky bingo halls provided an important refuge from everyday experiences of stress and trauma, as well as increased women's risk for addiction, marginalization, and criticism. The findings illustrate how the bingo economy in isolated, rural First Nation communities influences tobacco use and second-hand smoke exposure, and how efforts to establish smoke-free bingos can be supported.
Effect of Anode Dielectric Coating on Hall Thruster Operation
International Nuclear Information System (INIS)
Dorf, L.; Raitses, Y.; Fisch, N.J.; Semenov, V.
2003-01-01
An interesting phenomenon observed in the near-anode region of a Hall thruster is that the anode fall changes from positive to negative upon removal of the dielectric coating, which is produced on the anode surface during the normal course of Hall thruster operation. The anode fall might affect the thruster lifetime and acceleration efficiency. The effect of the anode coating on the anode fall is studied experimentally using both biased and emissive probes. Measurements of discharge current oscillations indicate that thruster operation is more stable with the coated anode
Magnetoresistance and Hall resistivity of semimetal WTe2 ultrathin flakes.
Luo, Xin; Fang, Chi; Wan, Caihua; Cai, Jialin; Liu, Yong; Han, Xiufeng; Lu, Zhihong; Shi, Wenhua; Xiong, Rui; Zeng, Zhongming
2017-04-07
This article reports the characterization of WTe 2 thin flake magnetoresistance and Hall resistivity. We found it does not exhibit magnetoresistance saturation when subject to high fields, in a manner similar to their bulk characteristics. The linearity of Hall resistivity in our devices confirms the compensation of electrons and holes. By relating experimental results to a classic two-band model, the lower magnetoresistance values in our samples is demonstrated to be caused by decreased carrier mobility. The dependence of mobility on temperature indicates the main role of optical phonon scattering at high temperatures. Our results provide more detailed information on carrier behavior and scattering mechanisms in WTe 2 thin films.
Measurement of the Hall effect in semiconductors at supersonic frequencies
International Nuclear Information System (INIS)
Putyato, I.V.; Sukhanov, S.; Lezhnev, N.B.
1978-01-01
A new method of measuring the Hall effect in variable magnetic fields at super-high frequencies using slotted line is proposed. The method is applied to the measurement of the Hall effect in n-InSb samples. It is shown that the level of output signal of samples reduces with the increasing the charge carrier concentration and with decreasing the mobility. But the range of quadratic part of the dependence of the output signal power on the control current increases. It is stated that the output signal of samples does not depend on the magnetic field frequency in the range of 4-7.3 GHz
Measurement of the Hall effect in semiconductors at supersonic frequencies
Energy Technology Data Exchange (ETDEWEB)
Putyato, I V; Sukhanov, S; Lezhnev, N B [AN Tadzhikskoj SSR, Khorog. Pamirskij Biologicheskij Inst.
1978-01-01
A new method of measuring the Hall effect in variable magnetic fields at super-high frequencies using slotted line is proposed. The method is applied to the measurement of the Hall effect in n-InSb samples. It is shown that the level of output signal of samples reduces with the increasing the charge carrier concentration and with decreasing the mobility. But the range of quadratic part of the dependence of the output signal power on the control current increases. It is stated that the output signal of samples does not depend on the magnetic field frequency in the range of 4-7.3 GHz.
European Union security policy through strategic culture
Directory of Open Access Journals (Sweden)
Beriša Hatidža
2014-01-01
Full Text Available In this paper, we shall pay attention to the security policy of the European Union, through the strategic culture, starting from the existing various options for cooperation in the field of security and defense. Our goal is to look at the implementation of the Strategic Culture of the European Union (EU SK, research ways to improve the international position of the Union and its impact on policy cooperation and trust with other collectives. Analysis of flexible cooperation between the European Union, as well as access to special procedures in the field of security and defense policy, we will follow the ambition and capacity in implementing the same. Paper aims to introduce the idea of the European Union, which allows its members to rationally consider and check the box of options available to decision makers. In this regard, the EU seeks to build its own armed forces to protect the association of interests-investment terms. Reviewing and understanding the strategic culture of the EU by countries that are not its members can be seen as reasons for strengthening the capacity of the Union for the realization of the impact of the global security as well as predicting its future steps.
Labor unions and safety climate: perceived union safety values and retail employee safety outcomes.
Sinclair, Robert R; Martin, James E; Sears, Lindsay E
2010-09-01
Although trade unions have long been recognized as a critical advocate for employee safety and health, safety climate research has not paid much attention to the role unions play in workplace safety. We proposed a multiple constituency model of workplace safety which focused on three central safety stakeholders: top management, ones' immediate supervisor, and the labor union. Safety climate research focuses on management and supervisors as key stakeholders, but has not considered whether employee perceptions about the priority their union places on safety contributes contribute to safety outcomes. We addressed this gap in the literature by investigating unionized retail employee (N=535) perceptions about the extent to which their top management, immediate supervisors, and union valued safety. Confirmatory factor analyses demonstrated that perceived union safety values could be distinguished from measures of safety training, workplace hazards, top management safety values, and supervisor values. Structural equation analyses indicated that union safety values influenced safety outcomes through its association with higher safety motivation, showing a similar effect as that of supervisor safety values. These findings highlight the need for further attention to union-focused measures related to workplace safety as well as further study of retail employees in general. We discuss the practical implications of our findings and identify several directions for future safety research. 2009 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Fuller-Rowell, T.J.; Evans, D.S.
1987-01-01
The series of polar-orbiting National Oceanic and Atmospheric Administration spacecraft TIROS, NOAA 6, and NOAA 7 have been monitoring the particle influx into the atmosphere since late 1978. This data base has been used to construct statistical global patterns of height-integrated Pedersen and Hall conductivities for a discrete set of auroral activity ranges. The observations of energy influx and ''characteristic electron energy'' have been binned in a 1 0 latitude and 2 0 magnetic local time grid and ordered by an auroral activity index. This index is an estimate of the energy deposited into a single hemisphere by incident particles, a parameter generated directly from the particle observations and, therefore, internally consistent with the statistical patterns that are constructed. An average electron spectrum is associated with each characteristic energy, which enables a height profile of ionization rate in the upper atmosphere to be determined. The use of a pressure coordinate system insures that the normalized ionization rate profiles are independent of atmospheric model parameters. To create the statistical pattern of height-integrated conductivities, however, vertical profiles of atmospheric temperature and composition are assumed, and the ion density enhancements are evaluated from a chemical balance between ion production and recombination based on an ''effective'' recombination coefficient. The data base can also provide the statistical pattern of particle heating rates and ionization rates over a three-dimensional grid suitable as input to more sophisticated ionospheric and neutral thermospheric codes. copyright American Geophysical Union
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.
International Nuclear Information System (INIS)
Mani, Arjun; Benjamin, Colin
2016-01-01
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. (paper)
Student representation and activism in universities in Kenya
African Journals Online (AJOL)
Higher education; student politics; student activism; student unionism; university governance; ..... These titles may differ from one university to another, but ..... Qualitative Research for Education: An Introduction to Theory and .... Doctoral thesis.
[Female nuptiality: the importance of consensual unions].
Ojeda, N
1988-01-01
Mexico's National Demographic Survey of 1982 indicated that 58.4% of ever married women had been in marriages celebrated both civilly and religiously, 24.4% had been in civil marriages only, 3.0% had been in religious marriages only, and 14.2% had been in consensual unions. Transitions from 1 type of union to another by the same couple are very common, however. 53.6% of women began their conjugal lives in civil and religious marriages, 19.3% in civil marriages only, 2.3% in religious marriages only, and 24.6% in consensual unions. About 1/2 of consensual unions are eventually legalized, but the rate is lower in the less advantaged socioeconomic sectors which have a higher proportion of consensual unions. Corrected data show that only 7.5% of Mexican women remain single at the age of 45. The average age at 1st union is 21.4 years. Marriage patterns differ significantly in different social sectors. The proportion of women consensual unions varied from 16.1% for the new bourgeoisie, defined as administrators, technicians, high-level workers, and professional public officials, to over 30% for nonsalaried workers, peasants, and agricultural wage workers. Peasants, agricultural wage workers and nonagricultural nonsalaried workers had the lowest marriage ages and the highest proportion married by age 20. In the various proletarian groups, only 2.8-3.7% remained single at age 45, and 42.5%-51.3% were married or in union by age 20. Proletarian women had intermediate ages at 1st marriage. Women of the new bourgeoisie had the highest age at 1st union, 23 years, but the lowest proportion single at age 45, 1.8%. The traditional bourgeoisie and new bourgeoisie had the 2nd lowest age at 1st union, 21.9, and a proportion never married at age 45 that was similar to the national average. The proportion single at age 45 was highest among peasants and agricultural wage workers, reaching 11.3%.
Valley polarized quantum Hall effect and topological insulator phase transitions in silicene
Tahir, M.; Schwingenschlö gl, Udo
2013-01-01
encountered for graphene, in particular the zero band gap and weak spin orbit interaction. We demonstrate a valley polarized quantum Hall effect and topological insulator phase transitions. We use the Kubo formalism to discuss the Hall conductivity and address
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.
Trade Union Mergers: A Survey of the Literature.
Michelson, Grant
2000-01-01
Examines trade union mergers highlighting merger forms, merger motivation, role played by union officers, and merger waves. Discusses the consequences of mergers on members and union performance and concludes that union merger activity has had little impact. (Contains 74 references.) (JOW)
Zheng Manqing: The Memorial Hall and Legacy of the Master of Five Excellences in Taiwan
Directory of Open Access Journals (Sweden)
Russ Mason
2012-07-01
Full Text Available Professor Zheng Manqing (1902-1975, a fine artist and a notable taijiquan disciple of Yang Chengfu, emigrated to Taiwan in 1949 following the Chinese civil war between the Guomindang and Maoist factions. Under Republic of China President Chiang Kai-shek’s Cultural Renaissance Movement, Zheng played an important role in preserving the cultural treasures of traditional China. During the period of Mao Zedong’s Cultural Revolution when the Mainland was veiled to foreign eyes behind the Bamboo Curtain, Zheng was instrumental in introducing taijiquan and other elements of Chinese culture to the West. Zheng passed away at his home in Yonghe, Taiwan in 1975 but not before establishing an international reputation for his mastery in taijiquan and other arts. Recently, a portion of his former residence was converted into a memorial hall (the Zheng Manqing Jinian Guan by senior students interested in preserving his martial tradition, paintings, calligraphy, and other artifacts. This article provides a brief history of Zheng’s life and his legacy in Taiwan, as well as a photographic tour of the Zheng Manqing Memorial Hall.
The effects of union mergers and internal restructuring:
DEFF Research Database (Denmark)
Navrbjerg, Steen Erik; Larsen, Trine Pernille
2016-01-01
Trade union mergers and restructuring are often seen as strategy for union revitalisation and renewal and have been ongoing in the majority of European trade unions. This paper explores how recent union mergers and internal restructuring has affected unions service provision, union democracy...... and interest representation. This is analysed drawing on longitudinal data from two Danish shop steward surveys conducted in 1998 and 2010, comparing shop stewards in merged and non-merged unions respectively. The main results are that although it could be expected that union mergers and internal restructuring......, where union size and less so the union’s recent merger and restructuring history appears to affect shop stewards’ relations with their unions....
Directory of Open Access Journals (Sweden)
López-Torrijo, Manuel
2009-06-01
Full Text Available This article presents a comparative study of the care of students with severe and permanent educational needs in the six EU countries with greater rates of educational inclusion, (Italy, Greece, Portugal, Norway, Cyprus and Iceland. Such study has been done bearing in mind the following indicators: Analysis of educational needs, identification of deficit, schooling of students in Specific Centres for Special Education, legislative frame, responsibility for schooling and rendering of services, frame and models of schooling, state and functions of Specific Centres of Special Education, curricula of the inclusion, Human resources, family role and funding. From the aforementioned lines are deduced the trends in policies and educational practices carried out are followed. Conclude the necessary changes for the improvement of the future educational educational inclusion. Este artículo presenta un estudio comparado de la atención realizada a los alumnos con discapacidades graves y permanentes en los seis países de la UE que presentan mayores índices de inclusión educativa (Italia, Grecia, Portugal, Noruega, Chipre e Islandia. Dicho estudio está realizado teniendo en cuenta los siguientes indicadores: concepción de las necesidades educativas especiales, identificación de los déficit, alumnado escolarizado en Centros Específicos de Educación Especial, marco legislativo, responsabilidad de escolarización y prestación de servicios, modelo y modalidades de escolarización, estado y funciones de los Centros Específicos de Educación Especial, currículo de la inclusión, recursos humanos, papel de las familias y financiación. De ahí se deducen las tendencias en las políticas y las prácticas educativas realizadas y se concluyen los cambios necesarios para mejorar la inclusión educativa en un futuro.
A conformal field theory description of fractional quantum Hall states
Ardonne, E.
2002-01-01
In this thesis, we give a description of fractional quantum Hall states in terms of conformal field theory (CFT). As was known for a long time, the Laughlin states could be written in terms of correlators of chiral vertex operators of a c=1 CFT. It was shown by G. Moore and N. Read that more general
The Hall-induced stability of gravitating fluids
Karmakar, P. K.; Goutam, H. P.
2018-05-01
We analyze the stability behavior of low-density partially ionized self-gravitating magnetized unbounded dusty plasma fluid in the presence of the Hall diffusion effects (HDEs) in the non-ideal magnetohydrodynamic (MHD) equilibrium framework. The effects of inhomogeneous self-gravity are methodically included in the basic model tapestry. Application of the Fourier plane-wave perturbative treatment decouples the structuration representative parameters into a linear generalized dispersion relation (sextic) in a judicious mean-fluid approximation. The dispersion analysis shows that the normal mode, termed as the gravito-magneto-acoustic (GMA) mode, is drastically modified due to the HDEs. This mode is highly dispersive, and driven unstable by the Hall current resulting from the symmetry-breaking of electrons and ions relative to the magnetic field. The mode feature, which is derived from a modified induction with the positive Hall, is against the ideal MHD. It is further demonstrated that the HDEs play stabilizing roles by supporting the cloud against gravitational collapse. Provided that the HDEs are concurrently switched off, the collapse occurs on the global spatial scale due to enhanced inward accretion of the gravitating dust constituents. It is seen explicitly that the enhanced dust-charge leads to stabilizing effects. Besides, the Hall-induced fluctuations, as propagatory wave modes, exhibit both normal and anomalous dispersions. The reliability checkup of the entailed results as diverse corollaries and special cases are illustratively discussed in the panoptic light of the earlier paradigmatic predictions available in the literature.
Numerical simulation of SMART-1 Hall-thruster plasma interactions
Tajmar, Martin; Sedmik, René; Scharlemann, Carsten
2009-01-01
SMART-1 has been the first European mission using a Hall thruster to reach the moon. An onboard plasma diagnostic package allowed a detailed characterization of the thruster exhaust plasma and its interactions with the spacecraft. Analysis of in-flight data revealed, amongst others, an unpredicted
Imaging of Coulomb-Driven Quantum Hall Edge States
Lai, Keji; Kundhikanjana, Worasom; Kelly, Michael A.; Shen, Zhi-Xun; Shabani, Javad; Shayegan, Mansour
2011-01-01
The edges of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime are divided into alternating metallic and insulating strips, with their widths determined by the energy gaps of the QHE states and the electrostatic Coulomb
Quantum energy teleportation in a quantum Hall system
Energy Technology Data Exchange (ETDEWEB)
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.
Interaction Induced Quantum Valley Hall Effect in Graphene
Directory of Open Access Journals (Sweden)
E. C. Marino
2015-03-01
Full Text Available We use pseudo-quantum electrodynamics in order to describe the full electromagnetic interaction of the p electrons in graphene in a consistent 2D formulation. We first consider the effect of this interaction in the vacuum polarization tensor or, equivalently, in the current correlator. This allows us to obtain the T→0 conductivity after a smooth zero-frequency limit is taken in Kubo’s formula. Thereby, we obtain the usual expression for the minimal conductivity plus corrections due to the interaction that bring it closer to the experimental value. We then predict the onset of an interaction-driven spontaneous quantum valley Hall effect below an activation temperature of the order of 2 K. The transverse (Hall valley conductivity is evaluated exactly and shown to coincide with the one in the usual quantum Hall effect. Finally, by considering the effects of pseudo-quantum electrodynamics, we show that the electron self-energy is such that a set of P- and T-symmetric gapped electron energy eigenstates are dynamically generated, in association with the quantum valley Hall effect.
Micro-four-point Probe Hall effect Measurement method
DEFF Research Database (Denmark)
Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong
2008-01-01
barriers and with a magnetic field applied normal to the plane of the sheet. Based on this potential, analytical expressions for the measured four-point resistance in presence of a magnetic field are derived for several simple sample geometries. We show how the sheet resistance and Hall effect...
Magnetic microbead detection using the planar Hall effect
International Nuclear Information System (INIS)
Ejsing, Louise; Hansen, Mikkel F.; Menon, Aric K.; Ferreira, Hugo A.; Graham, Daniel L.; Freitas, Paulo P.
2005-01-01
Magnetic sensors based on the planar Hall effect of exchanged-biased permalloy have been fabricated and characterized. It is demonstrated that the sensors are feasible for detecting just a few commercial 2.0 μm magnetic beads commonly used for bioseparation (Micromer-M, Micromod, Germany) and that the sensor sense current is sufficient to generate a signal from the beads
Particle-in-cell simulations of Hall plasma thrusters
Miranda, Rodrigo; Ferreira, Jose Leonardo; Martins, Alexandre
2016-07-01
Hall plasma thrusters can be modelled using particle-in-cell (PIC) simulations. In these simulations, the plasma is described by a set of equations which represent a coupled system of charged particles and electromagnetic fields. The fields are computed using a spatial grid (i.e., a discretization in space), whereas the particles can move continuously in space. Briefly, the particle and fields dynamics are computed as follows. First, forces due to electric and magnetic fields are employed to calculate the velocities and positions of particles. Next, the velocities and positions of particles are used to compute the charge and current densities at discrete positions in space. Finally, these densities are used to solve the electromagnetic field equations in the grid, which are interpolated at the position of the particles to obtain the acting forces, and restart this cycle. We will present numerical simulations using software for PIC simulations to study turbulence, wave and instabilities that arise in Hall plasma thrusters. We have sucessfully reproduced a numerical simulation of a SPT-100 Hall thruster using a two-dimensional (2D) model. In addition, we are developing a 2D model of a cylindrical Hall thruster. The results of these simulations will contribute to improve the performance of plasma thrusters to be used in Cubesats satellites currenty in development at the Plasma Laboratory at University of Brasília.
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"
Hall effects on MHD flow past an accelerated plate
International Nuclear Information System (INIS)
Soundalgekar, V.M.; Ravi, S.; Hiremath, S.B.
1980-01-01
An exact solution of the MHD flow of an incompressible, electrically conducting, viscous fluid past a uniformly accelerated plate is presented. The velocity profiles are shown graphically and the numerical values of axial and transverse components of skin friction are tabulated. At high values of the Hall parameter, ωtau, the velocity is found to be oscillatory near the plate. (author)
new concepts of a modified hall - petch type relationship
African Journals Online (AJOL)
NIJOTECH
Abstract. A modified form of the Hall - Perch equation, where the average grain diameter is replaced by the surface to volume ratio of internal boundaries (Sv), is considered. Working with this model, a flow stress – Sv relationship dominated by geometrically necessary dislocations (GNDs) is derived for the low strain region.
Effect of Hall Current and Finite Larmor Radius Corrections on ...
Indian Academy of Sciences (India)
Home; Journals; Journal of Astrophysics and Astronomy; Volume 37; Issue 3. Effect of Hall Current and Finite Larmor Radius Corrections on Thermal Instability of Radiative Plasma for Star Formation in Interstellar Medium (ISM). Sachin Kaothekar. Research Article Volume 37 Issue 3 September 2016 Article ID 23 ...
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.
Composite fermions a unified view of the quantum Hall regime
1998-01-01
One of the most exciting recent developments to have emerged from the quantum Hall effect is the subject of composite fermions. This important volume gives a self-contained, comprehensive description of the subject, including fundamentals, more advanced theoretical work, and results from experimental observations of composite fermions.
The Marketing of Residence Halls: A Question of Positioning.
Parker, R. Stephen; And Others
1996-01-01
A survey of 343 college residence hall directors revealed percentages of private and public institutions offering different amenities, main selling points in promotional brochures, and the most common resident complaints. Results were compared with those of a resident survey concerning the importance of various housing attributes. Implications for…
Virginia Tech's College Of Natural Resources Dedicates Cheatham Hall Expansion
Davis, Lynn
2003-01-01
Thanks to funding by private donors, Alyce Cheatham and her family of Portland, Oregon, Virginia Tech's College of Natural Resources will dedicate a much-needed, three-story addition to its current Cheatham Hall on Wednesday, March 19, at 2:30 p.m.
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
Field theory of anyons and the fractional quantum Hall effect
International Nuclear Information System (INIS)
Viefers, S.F.
1997-11-01
The thesis is devoted to a theoretical study of anyons, i.e. particles with fractional statistics moving in two space dimensions, and the quantum Hall effect. The latter constitutes the only known experimental realization of anyons in that the quasiparticle excitations in the fractional quantum Hall system are believed to obey fractional statistics. First, the properties of ideal quantum gases in two dimensions and in particular the equation of state of the free anyons gas are discussed. Then, a field theory formulation of anyons in a strong magnetic field is presented and later extended to a system with several species of anyons. The relation of this model to fractional exclusion statistics, i.e. intermediate statistics introduced by a generalization of the Pauli principle, and to the low-energy excitations at the edge of the quantum Hall system is discussed. Finally, the Chern-Simons-Landau-Ginzburg theory of the fractional quantum Hall effect is studied, mainly focusing on edge effects; both the ground state and the low-energy edge excitations are examined in the simple one-component model and in an extended model which includes spin effects
Magnus force on quantum Hall skyrmions and vortices
International Nuclear Information System (INIS)
Dhar, S.; Basu, B.; Bandyopadhyay, P.
2003-01-01
We have discussed here the Magnus force acting on the vortices and skyrmions in the quantum Hall systems. We have found that it is generated by the chirality of the system which is associated with the Berry phase and is same for both the cases
Single particle detection: Phase control in submicron Hall sensors
International Nuclear Information System (INIS)
Di Michele, Lorenzo; Shelly, Connor; Gallop, John; Kazakova, Olga
2010-01-01
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≅10 8 μ B has been achieved with a 600 nm-wide sensor.
Low-frequency noise in planar Hall effect bridge sensors
DEFF Research Database (Denmark)
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 kn...
Quantum Hall Effect: proposed multi-electron tunneling experiment
International Nuclear Information System (INIS)
Kostadinov, I.Z.
1985-11-01
Here we propose a tunneling experiment for the fractional and Integral Quantum Hall Effect. It may demonstrate multi-electron tunneling and may provide information about the nature of the macroscopic quantum states of 2D electronic liquid or solid. (author)
Observation of the fractional quantum Hall effect in graphene.
Bolotin, Kirill I; Ghahari, Fereshte; Shulman, Michael D; Stormer, Horst L; Kim, Philip
2009-11-12
When electrons are confined in two dimensions and subject to strong magnetic fields, the Coulomb interactions between them can become very strong, leading to the formation of correlated states of matter, such as the fractional quantum Hall liquid. In this strong quantum regime, electrons and magnetic flux quanta bind to form complex composite quasiparticles with fractional electronic charge; these are manifest in transport measurements of the Hall conductivity as rational fractions of the elementary conductance quantum. The experimental discovery of an anomalous integer quantum Hall effect in graphene has enabled the study of a correlated two-dimensional electronic system, in which the interacting electrons behave like massless chiral fermions. However, owing to the prevailing disorder, graphene has so far exhibited only weak signatures of correlated electron phenomena, despite intense experimental and theoretical efforts. Here we report the observation of the fractional quantum Hall effect in ultraclean, suspended graphene. In addition, we show that at low carrier density graphene becomes an insulator with a magnetic-field-tunable energy gap. These newly discovered quantum states offer the opportunity to study correlated Dirac fermions in graphene in the presence of large magnetic fields.
Mechanism of plateau formation in the fractional quantum Hall effect
International Nuclear Information System (INIS)
Bruus, H.; Hansen, O.P.; Hansen, E.B.
1988-01-01
Laughlin's fractionally charged quasi-holes and quasi-electrons are assumed to be pinned, and to be subject to a force j vectorxΦ 0 vector from the transport current. A force balance argument then explains the existence of Hall plateaus. (orig.)
Planar Hall effect sensor for magnetic micro- and nanobead detection
DEFF Research Database (Denmark)
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 ...
Mini array of quantum Hall devices based on epitaxial graphene
International Nuclear Information System (INIS)
Novikov, S.; Lebedeva, N.; Hämäläinen, J.; Iisakka, I.; Immonen, P.; Manninen, A. J.; Satrapinski, A.
2016-01-01
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 R 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 H,2 = 2 h/e 2 was smaller than the relative standard uncertainty of the measurement (<1 × 10 −7 ) limited by the used resistance bridge.
Hall Thruster Thermal Modeling and Test Data Correlation
Myers, James; Kamhawi, Hani; Yim, John; Clayman, Lauren
2016-01-01
The life of Hall Effect thrusters are primarily limited by plasma erosion and thermal related failures. NASA Glenn Research Center (GRC) in cooperation with the Jet Propulsion Laboratory (JPL) have recently completed development of a Hall thruster with specific emphasis to mitigate these limitations. Extending the operational life of Hall thursters makes them more suitable for some of NASA's longer duration interplanetary missions. This paper documents the thermal model development, refinement and correlation of results with thruster test data. Correlation was achieved by minimizing uncertainties in model input and recognizing the relevant parameters for effective model tuning. Throughout the thruster design phase the model was used to evaluate design options and systematically reduce component temperatures. Hall thrusters are inherently complex assemblies of high temperature components relying on internal conduction and external radiation for heat dispersion and rejection. System solutions are necessary in most cases to fully assess the benefits and/or consequences of any potential design change. Thermal model correlation is critical since thruster operational parameters can push some components/materials beyond their temperature limits. This thruster incorporates a state-of-the-art magnetic shielding system to reduce plasma erosion and to a lesser extend power/heat deposition. Additionally a comprehensive thermal design strategy was employed to reduce temperatures of critical thruster components (primarily the magnet coils and the discharge channel). Long term wear testing is currently underway to assess the effectiveness of these systems and consequently thruster longevity.
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.
An evaluation of krypton propellant in Hall thrusters
Linnell, Jesse Allen
Due to its high specific impulse and low price, krypton has long sparked interest as an alternate Hall thruster propellant. Unfortunately at the moment, krypton's relatively poor performance precludes it as a legitimate option. This thesis presents a detailed investigation into krypton operation in Hall thrusters. These findings suggest that the performance gap can be decreased to 4% and krypton can finally become a realistic propellant option. Although krypton has demonstrated superior specific impulse, the xenon-krypton absolute efficiency gap ranges between 2 and 15%. A phenomenological performance model indicates that the main contributors to the efficiency gap are propellant utilization and beam divergence. Propellant utilization and beam divergence have relative efficiency deficits of 5 and 8%, respectively. A detailed characterization of internal phenomena is conducted to better understand the xenon-krypton efficiency gap. Krypton's large beam divergence is found to be related to a defocusing equipotential structure and a weaker magnetic field topology. Ionization processes are shown to be linked to the Hall current, the magnetic mirror topology, and the perpendicular gradient of the magnetic field. Several thruster design and operational suggestions are made to optimize krypton efficiency. Krypton performance is optimized for discharge voltages above 500 V and flow rates corresponding to an a greater than 0.015 mg/(mm-s), where alpha is a function of flow rate and discharge channel dimensions (alpha = m˙alphab/Ach). Performance can be further improved by increasing channel length or decreasing channel width for a given flow rate. Also, several magnetic field design suggestions are made to enhance ionization and beam focusing. Several findings are presented that improve the understanding of general Hall thruster physics. Excellent agreement is shown between equipotential lines and magnetic field lines. The trim coil is shown to enhance beam focusing
Citizenship of the European Union under the Treaty of Lisbon
Directory of Open Access Journals (Sweden)
Ioana Nely MILITARU
2011-06-01
Full Text Available The paper is structured in two parts. The first part covers history, "Union citizenship, according to previous Treaties Lisbon Treaty, and the second refers to the privileges which they have as citizens of the Union Treaty as a result of reforming the European Union, referring to documents on which this Treaty adhere it recognizes as having the same legal force, treaties, (Treaty on European Union and the Treaty on the Functioning of the European Union.
Unions in small and medium-sized enterprises
DEFF Research Database (Denmark)
Holten, Ann-Louise; Crouch, Colin
2014-01-01
Trade unions are commonly weak in small- and medium-sized enterprises, which constitute a majority of European firms and are often family-owned. We investigate the influence of family ownership on employee membership, perceptions and experience with unions in Danish and Italian firms in the textile...... and clothing sector. Family ownership reduces union membership; and within family firms, the number of family members employed is negatively associated with unionization rates and employee perceptions of unions....
Quantum Hall conductivity in a Landau type model with a realistic geometry
International Nuclear Information System (INIS)
Chandelier, F.; Georgelin, Y.; Masson, T.; Wallet, J.-C.
2003-01-01
In this paper, we revisit some quantum mechanical aspects related to the quantum Hall effect. We consider a Landau type model, paying a special attention to the experimental and geometrical features of quantum Hall experiments. The resulting formalism is then used to compute explicitly the Hall conductivity from a Kubo formula
Current Percolation in Medium with Boundaries under Quantum Hall Effect Conditions
Directory of Open Access Journals (Sweden)
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.