Resident physicians in Mexico: tradition or humiliation

Directory of Open Access Journals (Sweden)

Donovan Casas Patiño

2013-08-01

Full Text Available Mexico has a great history and tradition in relation to the training of resident physicians, but what we find behind this process?, Power relations implied and not implied, unnoticed or ignored for convenience by the academic and health institutions, with the aggravation of forgetting its commitment to the training of men and women "professionals" and limited to meet another indicator of "human resources for health." The resident physician in academic and scientific training is immersed in this dehumanized maelstrom and ends up becoming a character for the domain of knowledge as power, forgetting that his act and its rationale lies in the principle of "primum non nocere" to that we would add: nor your person, nor your fellowman, much less whom you have the moral, ethical and civic responsibility to convey some of your knowledge and your experience, that is, part of your essence”.

Hall Sweet Home

Science.gov (United States)

Oguntoyinbo, Lekan

2011-01-01

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

Zheng Manqing: The Memorial Hall and Legacy of the Master of Five Excellences in Taiwan

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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 influence of a student's 'home' climate on room temperature and indoor environmental controls use in a modern halls of residence

OpenAIRE

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...

Sleep quality and some factors affecting sleep quality in the students living in the residence hall of a university

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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

Kertha Gosa Court Hall of Klungkung Bali as an effort to conserve cultural heritage based on traditional culture

Science.gov (United States)

Kurnia Widianti, An-nisaa; Bambang Studyanto, Anung

2018-03-01

Kertha Gosa Klungkung Court Hall in Bali is one of the relics of the cultural heritage of The Kingdom of Bali which is a part of the Klungkung Castle. The existence of Kertha Gosa Architecture Hall as one of the relics of cultural heritage holds historical values, especially Bali traditional values. Indonesia is a country which has the rich culture heritage history, especially on historical buildings. This research seeks for a redenomination to solve problems being faced recently, namely the lack of activities to conserve a historic building as an asset of the country and source of knowledge in education. Listed in Law Number 11 of 2010 the conservation has some criteria, such as : 1.it has 50 years or more; represents the period of a certain style lat least 50 years; has special meaning for the history, science, education, religion, and culture or cultural value as a nation’s personality. The procedure to conduct this research uses a descriptive method by doing observation, interviews, taking some pictures, official documents or personal and other data that have a relevance to the research related to object to describing the condition of the building systematically, factual and actual. Consideration of the selection of objects is based on research by looking at the criteria of architectural, historical and symbolic criteria. Kertha Gosa Hall classic has been there for 395 years was built with zoning system called Sanga Mandala or similar to a chess board using natural materials such as eben wood, and padas rocks which make it authentic and possesses characteristic values of patriotism expression. During the kingdom of Kertha Gosa, Court Hall was like a court nowadays, but people still trust the constructive value of Hindu religion and culture as a product of thinking and live experience.

FACTORS INFLUENCING PURCHASING DECISIONS FOR TRADITIONAL AND REGIONAL PRODUCTS AMONG RESIDENTS OF THE PODKARPACIE VOIVODESHIP

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Marta Kawa

2014-09-01

Full Text Available The paper presents the factors determining the choice of traditional and regional products by Podkarpacie residents. The surveyed consumers found the quality as the most important trait that encourages the purchase of traditional and regional products. The price has an important impact on decision in terms of purchase.

High-performance LED luminaire for sports hall

Science.gov (United States)

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.

An exploratory cluster randomised trial of a university halls of residence based social norms marketing campaign to reduce alcohol consumption among 1st year students.

Science.gov (United States)

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.

Structural Analysis of the Resident Assistant Cultural Diversity Questionnaire

Science.gov (United States)

Johnson, Vanessa D.; Kang, Young-Shin; Thompson, George F.

2011-01-01

This study investigated the five-factor structure of the Resident Assistant Cultural Diversity (RACD) instrument, which assesses resident assistant (RA) confidence in addressing issues of cultural diversity in college and university residence halls. The instrument has five components that explore RA confidence: (1) belief in the need for cultural…

A Redundancy Mechanism Design for Hall-Based Electronic Current Transformers

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Kun-Long Chen

2017-03-01

Full Text Available Traditional current transformers (CTs suffer from DC and AC saturation and remanent magnetization in many industrial applications. Moreover, the drawbacks of traditional CTs, such as closed iron cores, bulky volume, and heavy weight, further limit the development of an intelligent power protection system. In order to compensate for these drawbacks, we proposed a novel current measurement method by using Hall sensors, which is called the Hall-effect current transformer (HCT. The existing commercial Hall sensors are electronic components, so the reliability of the HCT is normally worse than that of the traditional CT. Therefore, our study proposes a redundancy mechanism for the HCT to strengthen its reliability. With multiple sensor modules, the method has the ability to improve the accuracy of the HCT as well. Additionally, the proposed redundancy mechanism monitoring system provides a condition-based maintenance for the HCT. We verify our method with both simulations and an experimental test. The results demonstrate that the proposed HCT with a redundancy mechanism can almost achieve Class 0.2 for measuring CTs according to IEC Standard 60044-8.

Experimental Studies of Anode Sheath Phenomena in a Hall Thruster Discharge

International Nuclear Information System (INIS)

Dorf, L.; Raitses, Y.; Fisch, N.J.

2004-01-01

Both electron-repelling and electron-attracting anode sheaths in a Hall thruster were characterized by measuring the plasma potential with biased and emissive probes [L. Dorf, Y. Raitses, V. Semenov, and N.J. Fisch, Appl. Phys. Let. 84 (2004) 1070]. In the present work, two-dimensional structures of the plasma potential, electron temperature, and plasma density in the near-anode region of a Hall thruster with clean and dielectrically coated anodes are identified. Possible mechanisms of anode sheath formation in a Hall thruster are analyzed. The path for current closure to the anode appears to be the determining factor in the anode sheath formation process. The main conclusion of this work is that the anode sheath formation in Hall thrusters differs essentially from that in the other gas discharge devices, like a glow discharge or a hollow anode, because the Hall thruster utilizes long electron residence times to ionize rather than high neutral pressures

Evacuation Simulation in Kalayaan Residence Hall, up Diliman Using Gama Simulation Software

Science.gov (United States)

Claridades, A. R. C.; Villanueva, J. K. S.; Macatulad, E. G.

2016-09-01

Agent-Based Modeling (ABM) has recently been adopted in some studies for the modelling of events as a dynamic system given a set of events and parameters. In principle, ABM employs individual agents with assigned attributes and behaviors and simulates their behavior around their environment and interaction with other agents. This can be a useful tool in both micro and macroscale-applications. In this study, a model initially created and applied to an academic building was implemented in a dormitory. In particular, this research integrates three-dimensional Geographic Information System (GIS) with GAMA as the multi-agent based evacuation simulation and is implemented in Kalayaan Residence Hall. A three-dimensional GIS model is created based on the floor plans and demographic data of the dorm, including respective pathways as networks, rooms, floors, exits and appropriate attributes. This model is then re-implemented in GAMA. Different states of the agents and their effect on their evacuation time were then observed. GAMA simulation with varying path width was also implemented. It has been found out that compared to their original states, panic, eating and studying will hasten evacuation, and on the other hand, sleeping and being on the bathrooms will be impedances. It is also concluded that evacuation time will be halved when path widths are doubled, however it is recommended for further studies for pathways to be modeled as spaces instead of lines. A more scientific basis for predicting agent behavior in these states is also recommended for more realistic results.

Sustainable livable housing: A review of what traditional urban areas residents find important

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Musibau Lukuman

2017-09-01

Full Text Available Sustainable livable housing is pre-condition for healthy living, improve quality of life and critical to economic and social survival. It also encompasses various aspects that predominantly depend on economic, social, cultural and environmental (ESCE conditions within the locality. To this end, this paper seeks to explore, classify and assess the sustainable livable housing attributes from the existing literatures through content analysis. A review of literature revealed a total of ninety two (92 constructs, which were further grouped nine (9 livable housing-related attributes groups. Well-structured questionnaires were administered to residents of traditional urban areas (TUA of Iwo Osun State, Nigeria with ninety two (92 constructs on Likert scale. Data were analyzed using descriptive statistic and relative importance index (RII. Out of (92 constructs from nine (9 livable housing-related attributes groups, the results identified seventy eight (78 important attributes (i.e. 35 most important and 43 important across groups and construct that TUA residents found important. Over RII was 0.409 for overall assessment of sustainable livable housing condition by TUA residents indicating that TUA residents are dissatisfied with their current housing conditions.

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.

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...

The Significance of a Building’s Energy Consumption Profiles for the Optimum Sizing of a Combined Heat and Power (CHP System—A Case Study for a Student Residence Hall

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.

Men's Identity Development: Issues and Implications for Residence Life

Science.gov (United States)

Scott, David A.; Livingston, Wade G.; Havice, Pamela A.; Cawthon, Tony W.

2012-01-01

Young men struggle with privilege and oppression in college and university residence halls just as they do in other educational and social contexts. While discussions and research about adolescent and adult identity development continue, little attention has focused on how a male student's identity development can impact residence life cultures on…

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.)

Resident training for eclampsia and magnesium toxicity management: simulation or traditional lecture?

Science.gov (United States)

Fisher, Nelli; Bernstein, Peter S; Satin, Andrew; Pardanani, Setul; Heo, Hye; Merkatz, Irwin R; Goffman, Dena

2010-10-01

To compare eclampsia and magnesium toxicity management among residents randomly assigned to lecture or simulation-based education. Statified by year, residents (n = 38) were randomly assigned to 3 educational intervention groups: Simulation→Lecture, Simulation, and Lecture. Postintervention simulations were performed for all and scored using standardized lists. Maternal, fetal, eclampsia management, and magnesium toxcity scores were assigned. Mann-Whitney U, Wilcoxon rank sum and χ(2) tests were used for analysis. Postintervention maternal (16 and 15 vs 12; P < .05) and eclampsia (19 vs 16; P < .05) scores were significantly better in simulation based compared with lecture groups. Postintervention magnesium toxcitiy and fetal scores were not different among groups. Lecture added to simulation did not lead to incremental benefit when eclampsia scores were compared between Simulation→Lecture and Simulation (19 vs 19; P = nonsignificant). Simulation training is superior to traditional lecture alone for teaching crucial skills for the optimal management of both eclampsia and magnesium toxicity, 2 life-threatening obstetric emergencies. Published by Mosby, Inc.

Speaking up about traditional and professionalism-related patient safety threats: a national survey of interns and residents.

Science.gov (United States)

Martinez, William; Lehmann, Lisa Soleymani; Thomas, Eric J; Etchegaray, Jason M; Shelburne, Julia T; Hickson, Gerald B; Brady, Donald W; Schleyer, Anneliese M; Best, Jennifer A; May, Natalie B; Bell, Sigall K

2017-11-01

Open communication between healthcare professionals about care concerns, also known as 'speaking up', is essential to patient safety. Compare interns' and residents' experiences, attitudes and factors associated with speaking up about traditional versus professionalism-related safety threats. Anonymous, cross-sectional survey. Six US academic medical centres, 2013-2014. 1800 medical and surgical interns and residents (47% responded). Attitudes about, barriers and facilitators for, and self-reported experience with speaking up. Likelihood of speaking up and the potential for patient harm in two vignettes. Safety Attitude Questionnaire (SAQ) teamwork and safety scales; and Speaking Up Climate for Patient Safety (SUC-Safe) and Speaking Up Climate for Professionalism (SUC-Prof) scales. Respondents more commonly observed unprofessional behaviour (75%, 628/837) than traditional safety threats (49%, 410/837); pbarrier to speaking up about unprofessional behaviour compared with traditional safety threats (58%, 482/837 vs 42%, 348/837; psafety vignette, even when they perceived high potential patient harm (20%, 49/251 vs 71%, 179/251; psafety vignette (OR 1.90, 99% CI 1.36 to 2.66 and 1.46, 1.02 to 2.09, respectively), while only a positive perception of SUC-Prof was associated with speaking up in the professionalism vignette (1.76, 1.23 to 2.50). Interns and residents commonly observed unprofessional behaviour yet were less likely to speak up about it compared with traditional safety threats even when they perceived high potential patient harm. Measuring SUC-Safe, and particularly SUC-Prof, may fill an existing gap in safety culture assessment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Investigations of Probe Induced Perturbations in a Hall Thruster

International Nuclear Information System (INIS)

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

2002-01-01

An electrostatic probe used to measure spatial plasma parameters in a Hall thruster generates perturbations of the plasma. These perturbations are examined by varying the probe material, penetration distance, residence time, and the nominal thruster conditions. The study leads us to recommendations for probe design and thruster operating conditions to reduce discharge perturbations, including metal shielding of the probe insulator and operation of the thruster at lower densities

[Common household traditional Chinese medicines].

Science.gov (United States)

Zhang, Shu-Yuan; Li, Mei; Fu, Dan; Liu, Yang; Wang, Hui; Tan, Wei

2016-02-01

With the enhancement in the awareness of self-diagnosis among residents, it's very common for each family to prepare common medicines for unexpected needs. Meanwhile, with the popularization of the traditional Chinese medicine knowledge, the proportion of common traditional Chinese medicines prepared at residents' families is increasingly higher than western medicines year by year. To make it clear, both pre-research and closed questionnaire research were adopted for residents in Chaoyang District, Beijing, excluding residents with a medical background. Based on the results of data, a analysis was made to define the role and influence on the quality of life of residents and give suggestions for relevant departments to improve the traditional Chinese medicine popularization and promote the traditional Chinese medicine market. Copyright© by the Chinese Pharmaceutical Association.

Burnout is Associated With Emotional Intelligence but not Traditional Job Performance Measurements in Surgical Residents.

Science.gov (United States)

Cofer, Kevin D; Hollis, Robert H; Goss, Lauren; Morris, Melanie S; Porterfield, John R; Chu, Daniel I

2018-02-23

.049). None of the 16 surgical milestone scores were significantly associated with burnout. Burnout is present in surgery residents and associated with emotional intelligence. There was no association of burnout with USMLE scores, ABSITE percentile, or surgical milestones. Traditional methods of assessing resident performance may not be capturing burnout and strategies to reduce burnout should consider targeting emotional intelligence. Published by Elsevier Inc.

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

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

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

A Small Modular Laboratory Hall Effect Thruster

Science.gov (United States)

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.

Applying mathematical models to predict resident physician performance and alertness on traditional and novel work schedules.

Science.gov (United States)

Klerman, Elizabeth B; Beckett, Scott A; Landrigan, Christopher P

2016-09-13

In 2011 the U.S. Accreditation Council for Graduate Medical Education began limiting first year resident physicians (interns) to shifts of ≤16 consecutive hours. Controversy persists regarding the effectiveness of this policy for reducing errors and accidents while promoting education and patient care. Using a mathematical model of the effects of circadian rhythms and length of time awake on objective performance and subjective alertness, we quantitatively compared predictions for traditional intern schedules to those that limit work to ≤ 16 consecutive hours. We simulated two traditional schedules and three novel schedules using the mathematical model. The traditional schedules had extended duration work shifts (≥24 h) with overnight work shifts every second shift (including every third night, Q3) or every third shift (including every fourth night, Q4) night; the novel schedules had two different cross-cover (XC) night team schedules (XC-V1 and XC-V2) and a Rapid Cycle Rotation (RCR) schedule. Predicted objective performance and subjective alertness for each work shift were computed for each individual's schedule within a team and then combined for the team as a whole. Our primary outcome was the amount of time within a work shift during which a team's model-predicted objective performance and subjective alertness were lower than that expected after 16 or 24 h of continuous wake in an otherwise rested individual. The model predicted fewer hours with poor performance and alertness, especially during night-time work hours, for all three novel schedules than for either the traditional Q3 or Q4 schedules. Three proposed schedules that eliminate extended shifts may improve performance and alertness compared with traditional Q3 or Q4 schedules. Predicted times of worse performance and alertness were at night, which is also a time when supervision of trainees is lower. Mathematical modeling provides a quantitative comparison approach with potential to aid

Psychiatry residents in a milieu participatory democracy: a resident's view.

Science.gov (United States)

Gersten, D

1978-11-01

Psychiatry residents respond with a variety of coping mechanisms to the lack of traditional structure in a milieu participatory democracy. To incorporate themselves into the system they must accept such democratic ideals as equality among staff and patients, group decision making, and free self-expression and give up some of their traditional ideas about staff and patient roles, treatment modalities, and the therapeutic environment. The author was a first-year resident in psychiatry on a university hospital inpatient therapeutic community; he discusses the conflicts between residents, who often adopt a "we-they" attitude, and the permanent staff, whose protectiveness of the ward community reflects their personal commitment to its ideals.

Topological Hall and spin Hall effects in disordered skyrmionic textures

KAUST Repository

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

KAUST Repository

Ndiaye, Papa Birame

2017-02-24

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

Nematic and Valley Ordering in Anisotropic Quantum Hall Systems

Science.gov (United States)

Parameswaran, S. A.; Abanin, D. A.; Kivelson, S. A.; Sondhi, S. L.

2010-03-01

We consider a multi-valley two dimensional electron system in the quantum Hall effect (QHE) regime. We focus on QHE states that arise due to spontaneous breaking of the valley symmetry by the Coulomb interactions. We show that the anisotropy of the Fermi surface in each valley, which is generally present in such systems, favors states where all the electrons reside in one of the valleys. In a clean system, the valley ordering occurs via a finite temperature Ising-like phase transition, which, owing to the Fermi surface anisotropy, is accompanied by the onset of nematic order. In a disordered system, domains of opposite polarization are formed, and therefore long-range valley order is destroyed, however, the resulting state is still compressible. We discuss the transport properties in ordered and disordered regimes, and point out the possible relation of our results to recent experiments in AlAs [1]. [1] Y. P. Shkolnikov, S. Misra, N. C. Bishop, E. P. De Poortere, and M. Shayegan, Observation of Quantum Hall ``Valley Skyrmions", Phys. Rev. Lett. 95, 068809 (2005)[2] D.A. Abanin, S.A. Parameswaran, S.A. Kivelson and S.L. Sondhi, Nematic and Valley Ordering in Anisotropic Quantum Hall Systems, to be published.

Hall effect in hopping regime

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.

Hall effect in hopping regime

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-15

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

Giant anisotropic magnetoresistance in a quantum anomalous Hall insulator

Science.gov (United States)

Kandala, Abhinav; Richardella, Anthony; Kempinger, Susan; Liu, Chao-Xing; Samarth, Nitin

2015-01-01

When a three-dimensional ferromagnetic topological insulator thin film is magnetized out-of-plane, conduction ideally occurs through dissipationless, one-dimensional (1D) chiral states that are characterized by a quantized, zero-field Hall conductance. The recent realization of this phenomenon, the quantum anomalous Hall effect, provides a conceptually new platform for studies of 1D transport, distinct from the traditionally studied quantum Hall effects that arise from Landau level formation. An important question arises in this context: how do these 1D edge states evolve as the magnetization is changed from out-of-plane to in-plane? We examine this question by studying the field-tilt-driven crossover from predominantly edge-state transport to diffusive transport in Crx(Bi,Sb)2−xTe3 thin films. This crossover manifests itself in a giant, electrically tunable anisotropic magnetoresistance that we explain by employing a Landauer–Büttiker formalism. Our methodology provides a powerful means of quantifying dissipative effects in temperature and chemical potential regimes far from perfect quantization. PMID:26151318

The role of the men's hall in the development of the Anglo-Saxon superego.

Science.gov (United States)

Earl, J W

1983-05-01

This paper is a historical study of ritual space--a bit of psychoanalytic anthropology applied to a particular case, the evolution of the men's hall among the early Anglo-Saxons. I focus particularly on the ritual functions of poetry in the hall, the same poetry which is our major evidence regarding the hall, especially the epic Beowulf. I define the hall as a cultural institution, and redefine the native poetic tradition in relation to the hall's varied ritual life, with which the poetry is so occupied. Though my argument is focused on the hall, it includes a framework of theoretical concerns. Early Anglo-Saxon culture is of anthropological interest chiefly because of its rapid and dramatic emergence from Germanic tribal prehistory into a leading role in the civilization of Christian Europe. The conquest of Britain by the Anglo-Saxons in the fifth and sixth centuries, and their conversion soon afterward, is a case history of the transformations of a tribal society suddenly introduced to the special forces of civilization and the higher religions that control them. The Anglo-Saxons are fascinating in this regard because of the fortuitous developments that prepared for this transformation and made it so successful.

How Expectations Do Not Equate with Practice: The Gendered Reality of the Female Resident Assistant

Science.gov (United States)

Cousineau, Luc; Chambers, Lori

2015-01-01

Residence hall and house employees (resident assistants) at postsecondary institutions in Canada are an important part of the social and rules-based structure that allows these facilities to operate. These employees are challenged with varied situations that require the application of mediation, authoritarian, recognition, and referral skills. To…

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

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.)

Virtual surgery simulation versus traditional approaches in training of residents in cervical pedicle screw placement.

Science.gov (United States)

Hou, Yang; Shi, Jiangang; Lin, Yanping; Chen, Huajiang; Yuan, Wen

2018-06-01

The cervical screw placement is one of the most difficult procedures in spine surgery, which often needs a long period of repeated practices and could cause screw placement-related complications. We performed this cadaver study to investigate the effectiveness of virtual surgical training system (VSTS) on cervical pedicle screw instrumentation for residents. A total of ten novice residents were randomly assigned to two groups: the simulation training (ST) group (n = 5) and control group (n = 5). The ST group received a surgical training of cervical pedicle screw placement on VSTS and the control group was given an introductory teaching session before cadaver test. Ten fresh adult spine specimens including 6 males and 4 females were collected, and were randomly allocated to the two groups. The bilateral C3-C6 pedicle screw instrumentation was performed in the specimens of the two groups, respectively. After instrumentation, screw positions of the two groups were evaluated by image examinations. There was significantly statistical difference in screw penetration rates between the ST (10%) and control group (62.5%, P VSTS as an advanced training tool exhibited promising effects on improving performance of novice residents in cervical pedicle screw placement compared with the traditional teaching methods.

Topological Hall and Spin Hall Effects in Disordered Skyrmionic Textures

OpenAIRE

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...

Video-Based Learning vs Traditional Lecture for Instructing Emergency Medicine Residents in Disaster Medicine Principles of Mass Triage, Decontamination, and Personal Protective Equipment.

Science.gov (United States)

Curtis, Henry A; Trang, Karen; Chason, Kevin W; Biddinger, Paul D

2018-02-01

Introduction Great demands have been placed on disaster medicine educators. There is a need to develop innovative methods to educate Emergency Physicians in the ever-expanding body of disaster medicine knowledge. The authors sought to demonstrate that video-based learning (VBL) could be a promising alternative to traditional learning methods for teaching disaster medicine core competencies. Hypothesis/Problem The objective was to compare VBL to traditional lecture (TL) for instructing Emergency Medicine residents in the American College of Emergency Physicians (ACEP; Irving, Texas USA) disaster medicine core competencies of patient triage and decontamination. A randomized, controlled pilot study compared two methods of instruction for mass triage, decontamination, and personal protective equipment (PPE). Emergency Medicine resident learning was measured with a knowledge quiz, a Likert scale measuring comfort, and a practical exercise. An independent samples t-test compared the scoring of the VBL with the TL group. Twenty-six residents were randomized to VBL (n=13) or TL (n=13). Knowledge score improvement following video (14.9%) versus lecture (14.1%) did not differ significantly between the groups (P=.74). Comfort score improvement also did not differ (P=.64) between video (18.3%) and lecture groups (15.8%). In the practical skills assessment, the VBL group outperformed the TL group overall (70.4% vs 55.5%; Plearning vs traditional lecture for instructing emergency medicine residents in disaster medicine principles of mass triage, decontamination, and personal protective equipment. Prehosp Disaster Med. 2018;33(1):7-12.

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 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

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 understanding of art students toward characteristic of Negeri Sembilan Minangkabau Traditional House

Directory of Open Access Journals (Sweden)

Taharuddin Nurul Shima

2016-01-01

Full Text Available In Negeri Sembilan, they are still practicing Minangkabau culture and custom. Element of uniqueness in Negeri. Sembilan has been shown on its architectural where the houses have dramatic curved roof structures with multitier. The art and architecture features a unique regional style. This house fills with cultural values, customs and reflects the people’s understanding about designing art and architecture that is in harmony with nature. The house serves as a residence, a hall for family meetings, and for ceremonial activities. This research, studies the understanding of art students towards the characteristic that are found in the Negeri Sembilan Minangkabau Traditional House (NSMTH in Negeri Sembilan, Malaysia. The objectives are to identify the element of characteristic that shows the identity of Negeri Sembilan Minangkabau Traditional House and to determine the level of understanding on characteristic of a Minangkabau house by art students. Scope of this research is on understanding of Faculty Art & Design student that has syllabus on Malay art. The research methodology that been use in this research is quantitative where surveys are made among the art students

Skyrmions and Hall viscosity

Science.gov (United States)

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.

Using the Leaderless Group Discussion Technique for the Selection of Residence Hall Counselors

Science.gov (United States)

Banta, Trudy W.; McCormick, Jane E.

1969-01-01

Describes successful effort to involve head residents in selection responsibilities. Discusses use of Record of Previous Leadership Experience, behavior ratings adapted from Interview and LGD Rating Scale (T. W. Banta) recommendation from head resident as selection criteria. (CJ)

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.

A Study to Identify the Transitional Training Needs for United States Army Medical Residents

Science.gov (United States)

1988-07-29

Books Kotler , Philip, and Roberta Clarke. Marketing for Health Care Organizations. Englewood Cliffs: Prentice Hall, 1987. Runyon, Richard P., and...8217 and most can benefit from instruction in administrative principles and practices during residency" (444). A focus began to turn toward residency...leadership development, office communi-ations, professional and legal obligations, Rawls 8 and practice marketing . Because these newly trained physicians

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

A Comparison of Training Experience, Training Satisfaction, and Job Search Experiences between Integrated Vascular Surgery Residency and Traditional Vascular Surgery Fellowship Graduates.

Science.gov (United States)

Colvard, Benjamin; Shames, Murray; Schanzer, Andres; Rectenwald, John; Chaer, Rabih; Lee, Jason T

2015-10-01

The first 2 integrated vascular residents in the United States graduated in 2012, and in 2013, 11 more entered the job market. The purpose of this study was to compare the job search experiences of the first cohort of integrated 0 + 5 graduates to their counterparts completing traditional 5 + 2 fellowship programs. An anonymous, Web-based, 15-question survey was sent to all 11 graduating integrated residents in 2013 and to the 25 corresponding 5 + 2 graduating fellows within the same institution. Questions focused on the following domains: training experience, job search timelines and outcomes, and overall satisfaction with each training paradigm. Survey response was nearly 81% for the 0 + 5 graduates and 64% for the 5 + 2 graduates. Overall, there was no significant difference between residents and fellows in the operative experience obtained as measured by the number of open and endovascular cases logged. Dedicated research time during the entire training period was similar between residents and fellows. Nearly all graduates were extremely satisfied with their training and had positive experiences during their job searches with respect to starting salaries, numbers of offers, and desired practice type. More 0 + 5 residents chose academic and mixed practices over private practices compared with 5 + 2 fellowship graduates. Although longer term data are needed to understand the impact of the addition of 0 + 5 graduating residents to the vascular surgery work force, preliminary survey results suggest that both training paradigms (0 + 5 and 5 + 2) provide positive training experiences that result in excellent job search experiences. Based on the current and future need for vascular surgeons in the work force, the continued growth and expansion of integrated 0 + 5 vascular surgery residency positions as an alternative to traditional fellowship training is thus far justified. Copyright © 2015 Elsevier Inc. All rights reserved.

High-speed Internet Use and Academic Gratifications in the College Residence.

Science.gov (United States)

Matthews, Denise; Schrum, Lynne

2003-01-01

A multimethod exploration of undergraduates' high-speed Internet use in residence halls took a uses-and-gratifications approach and revealed Internet use as integral to students' lives. Students' negative comments about Internet distractions from academic work led to identification of an individual difference variable, internal locus of control of…

A review of the quantum Hall effects in MgZnO/ZnO heterostructures

Science.gov (United States)

Falson, Joseph; Kawasaki, Masashi

2018-05-01

This review visits recent experimental efforts on high mobility two-dimensional electron systems (2DES) hosted at the Mg x Zn1-x O/ZnO heterointerface. We begin with the growth of these samples, and highlight the key characteristics of ozone-assisted molecular beam epitaxy required for their production. The transport characteristics of these structures are found to rival that of traditional semiconductor material systems, as signified by the high electron mobility (μ > 1000 000 cm2 Vs‑1) and rich quantum Hall features. Owing to a large effective mass and small dielectric constant, interaction effects are an order of magnitude stronger in comparison with the well studied GaAs-based 2DES. The strong correlation physics results in robust Fermi-liquid renormalization of the effective mass and spin susceptibility of carriers, which in turn dictates the parameter space for the quantum Hall effect. Finally, we explore the quantum Hall effect with a particular emphasis on the spin degree of freedom of carriers, and how their large spin splitting allows control of the ground states encountered at ultra-low temperatures within the fractional quantum Hall regime. We discuss in detail the physics of even-denominator fractional quantum Hall states, whose observation and underlying character remain elusive and exotic.

Residents' Perceptions of Property Rating in a Traditional African City

African Journals Online (AJOL)

The success of any revenue generation drive by government depends on the support shown by an area's residents. This in turn depends on the latter's perceptions of the revenue. This study examines the influence of residents' perceptions of a property tax in the different residential districts of Ogbomoso, Oyo State, Nigeria.

Breathing oscillations in enlarged cylindrical-anode-layer Hall plasma accelerator

Energy Technology Data Exchange (ETDEWEB)

Geng, S. F.; Wang, C. X. [Southwestern Institute of Physics, Chengdu 610041 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Tang, D. L.; Qiu, X. M. [Southwestern Institute of Physics, Chengdu 610041 (China); Fu, R. K. Y. [Plasma Technology Limited, Festival Walk Tower, Tat Chee Avenue, Kowloon, Hong Kong (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

2013-05-28

Breathing oscillations in the discharge of an enlarged cylindrical-anode-layer Hall plasma accelerator are investigated by three-dimensional particle-in-cell (PIC) simulation. Different from the traditional breathing mode in a circular Hall plasma accelerator, the bulk plasma oscillation here is trigged by the potential barrier generated by the concentrated ion beam and substantial enough to compete with the anode voltage. The electric field near the anode is suppressed by the potential barrier thereby decreasing the electron density by {approx}36%. The discharge is restored to the normal level after the concentrated beam explodes and then it completes one cycle of electro-driven breathing oscillation. The breathing mode identified by the PIC simulation has a frequency range of {approx}156 kHz-{approx}250 kHz and does not vary monotonically with the discharge voltage.

Not your grandfather's concert hall

Science.gov (United States)

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.

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.)

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

Science.gov (United States)

2010-02-19

... 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...

Hall Effect Gyrators and Circulators

Science.gov (United States)

Viola, Giovanni; DiVincenzo, David P.

2014-04-01

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

"But It's Not the Space That I Would Need": Narrative of LGBTQ Students' Experiences in Campus Housing

Science.gov (United States)

Kortegast, Carrie A.

2017-01-01

Lesbian, gay, bisexual, transgender, and queer (LGBTQ) student perceptions of their residence hall environments are influenced by interactions with peers, resident assistants, residential life administrators, and campus policies. Using the tradition of storytelling and drawing upon the experience of 11 LGBTQ participants, this article provides a…

First-Year Residents Outperform Third-Year Residents after Simulation-Based Education in Critical Care Medicine

Science.gov (United States)

Singer, Benjamin D.; Corbridge, Thomas C.; Schroedl, Clara J.; Wilcox, Jane E.; Cohen, Elaine R.; McGaghie, William C.; Wayne, Diane B.

2012-01-01

Introduction Prior research shows that gaps exist in internal medicine residents’ critical care knowledge and skills. The purpose of this study was to compare the bedside critical care competency of first-year residents who received a simulation-based educational intervention plus clinical training to third-year residents who received clinical training alone. Methods During their first three months of residency, a group of first-year residents completed a simulation-based educational intervention. A group of traditionally-trained third-year residents who did not receive simulation-based training served as a comparison group. Both groups were evaluated using a 20-item clinical skills assessment at the bedside of a patient receiving mechanical ventilation at the end of their medical intensive care unit rotation. Scores on the skills assessment were compared between groups. Results Simulator-trained first-year residents (n=40) scored significantly higher compared to traditionally-trained third-year residents (n=27) on the bedside assessment, 91.3% (95% CI 88.2% to 94.3%) vs. 80.9% (95% CI 76.8% to 85.0%), P = simulation-based educational intervention demonstrated higher clinical competency than third-year residents who did not undergo simulation training. Critical care competency cannot be assumed after clinical ICU rotations; simulation-based curricula can help ensure residents are proficient to care for critically ill patients. PMID:23222546

Use of a Behavioral Contract with Resident Assistants: Prelude to a Health Fair.

Science.gov (United States)

Morgan, John D.; Hyner, Gerald C.

1984-01-01

Presents a conceptual model which focuses on goals of student government in residence halls. The model has two fundamental processes. One focuses on short term goals and activities catering to creation of environment. The second has long term effects referred to as lifelong personal development. (JAC)

Spin Hall effects

Science.gov (United States)

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

Discharge Oscillations in a Permanent Magnet Cylindrical Hall-Effect Thruster

Science.gov (United States)

Polzin, K. A.; Sooby, E. S.; Raitses, Y.; Merino, E.; Fisch, N. J.

2009-01-01

Measurements of the discharge current in a cylindrical Hall thruster are presented to quantify plasma oscillations and instabilities without introducing an intrusive probe into the plasma. The time-varying component of the discharge current is measured using a current monitor that possesses a wide frequency bandwidth and the signal is Fourier transformed to yield the frequency spectra present, allowing for the identification of plasma oscillations. The data show that the discharge current oscillations become generally greater in amplitude and complexity as the voltage is increased, and are reduced in severity with increasing flow rate. The breathing mode ionization instability is identified, with frequency as a function of discharge voltage not increasing with discharge voltage as has been observed in some traditional Hall thruster geometries, but instead following a scaling similar to a large-amplitude, nonlinear oscillation mode recently predicted in for annular Hall thrusters. A transition from lower amplitude oscillations to large relative fluctuations in the oscillating discharge current is observed at low flow rates and is suppressed as the mass flow rate is increased. A second set of peaks in the frequency spectra are observed at the highest propellant flow rate tested. Possible mechanisms that might give rise to these peaks include ionization instabilities and interactions between various oscillatory modes.

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

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.

Tunneling Anomalous and Spin Hall Effects.

Science.gov (United States)

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.

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)

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....

Hall viscosity of hierarchical quantum Hall states

Science.gov (United 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.

Spin Hall effect by surface roughness

KAUST Repository

Zhou, Lingjun

2015-01-08

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

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

Nondestructive hall coefficient measurements using ACPD techniques

Science.gov (United States)

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

Particle-in-cell numerical simulations of a cylindrical Hall thruster with permanent magnets

Science.gov (United States)

Miranda, Rodrigo A.; Martins, Alexandre A.; Ferreira, José L.

2017-10-01

The cylindrical Hall thruster (CHT) is a propulsion device that offers high propellant utilization and performance at smaller dimensions and lower power levels than traditional Hall thrusters. In this paper we present first results of a numerical model of a CHT. This model solves particle and field dynamics self-consistently using a particle-in-cell approach. We describe a number of techniques applied to reduce the execution time of the numerical simulations. The specific impulse and thrust computed from our simulations are in agreement with laboratory experiments. This simplified model will allow for a detailed analysis of different thruster operational parameters and obtain an optimal configuration to be implemented at the Plasma Physics Laboratory at the University of Brasília.

Topologically induced fractional Hall steps in the integer quantum Hall regime of MoS 2

Science.gov (United States)

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.

Stephen Hall Receives 2012 Walter Sullivan Award for Excellence in Science Journalism-Features: Citation

Science.gov (United States)

Pearson, Helen

2013-01-01

Stephen Hall, a freelance science writer and science-communication teacher, received the Walter Sullivan Award for Excellence in Science Journalism-Features at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. Hall was honored for the article "At Fault?" published 15 September 2011 in Nature. The article examines the legal, personal, and political repercussions from a 2009 earthquake in L'Aquila, Italy for seismologists who had attempted to convey seismic risk assessments to the public. The 6.3 magnitude quake devastated the medieval town and caused more than 300 deaths. Six scientists and one government official were subsequently convicted of manslaughter and sentenced to prison for inadequately assessing and mischaracterizing the risks to city residents, despite the inexact nature of seismic risk assessment. The Sullivan award is for work published with a deadline pressure of more than 1 week.

Does the Room Matter? Active Learning in Traditional and Enhanced Lecture Spaces

Science.gov (United States)

Stoltzfus, Jon R.; Libarkin, Julie

2016-01-01

SCALE-UP–type classrooms, originating with the Student-Centered Active Learning Environment with Upside-down Pedagogies project, are designed to facilitate active learning by maximizing opportunities for interactions between students and embedding technology in the classroom. Positive impacts when active learning replaces lecture are well documented, both in traditional lecture halls and SCALE-UP–type classrooms. However, few studies have carefully analyzed student outcomes when comparable active learning–based instruction takes place in a traditional lecture hall and a SCALE-UP–type classroom. Using a quasi-experimental design, we compared student perceptions and performance between sections of a nonmajors biology course, one taught in a traditional lecture hall and one taught in a SCALE-UP–type classroom. Instruction in both sections followed a flipped model that relied heavily on cooperative learning and was as identical as possible given the infrastructure differences between classrooms. Results showed that students in both sections thought that SCALE-UP infrastructure would enhance performance. However, measures of actual student performance showed no difference between the two sections. We conclude that, while SCALE-UP–type classrooms may facilitate implementation of active learning, it is the active learning and not the SCALE-UP infrastructure that enhances student performance. As a consequence, we suggest that institutions can modify existing classrooms to enhance student engagement without incorporating expensive technology. PMID:27909018

ac spin-Hall effect

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

Hall C

Data.gov (United States)

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

Hall A

Data.gov (United States)

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

The role of traditional healers in the provision of health care and family planning services: Sinseh.

Science.gov (United States)

Kuek, K; Liow, T S

1985-01-01

The Chinese traditional medical system and pharmacology have a 1000-year history, and practitioners of Chinese traditional medicine play an important role in providing health care and family planning services in China. Vast numbers of patients from all walks of life and of all races benefit from Chinese traditional medicine. Although there are no official government records on the activities of practitioners of traditional medicine, the Chinese charitable medical organizations have some data on the nature of available services and their use. In China, in the context of significant government investment in health care facilities throughout the country and the proliferation of private hospitals, specialist centers, and general practitioners providing modern health care, the number of Chinese traditional charity medical aid departments, instead of falling by the wayside, has increased. The Chinese Traditional Medicine and Physician and Medicine Dealers Association of Malaysia was established 27 years ago. There are now officially 719 Chinese physicians and 1869 medical halls and Chinese physician infirmaries in Malaysia. The authors describe the status of Chinese physicians and medical halls in Malaysia, charitable organizations, and applications of Chinese traditional medicine.

Comparison of a traditional and non-traditional residential care facility for persons living with dementia and the impact of the environment on occupational engagement.

Science.gov (United States)

Richards, Kieva; D'Cruz, Rachel; Harman, Suzanne; Stagnitti, Karen

2015-12-01

Dementia residential facilities can be described as traditional or non-traditional facilities. Non-traditional facilities aim to utilise principles of environmental design to create a milieu that supports persons experiencing cognitive decline. This study aimed to compare these two environments in rural Australia, and their influence on residents' occupational engagement. The Residential Environment Impact Survey (REIS) was used and consists of: a walk-through of the facility; activity observation; interviews with residents and employees. Thirteen residents were observed and four employees interviewed. Resident interviews did not occur given the population diagnosis of moderate to severe dementia. Descriptive data from the walk-through and activity observation were analysed for potential opportunities of occupational engagement. Interviews were thematically analysed to discern perception of occupational engagement of residents within their facility. Both facilities provided opportunities for occupational engagement. However, the non-traditional facility provided additional opportunities through employee interactions and features of the physical environment. Interviews revealed six themes: Comfortable environment; roles and responsibilities; getting to know the resident; more stimulation can elicit increased engagement; the home-like experience and environmental layout. These themes coupled with the features of the environment provided insight into the complexity of occupational engagement within this population. This study emphasises the influence of the physical and social environment on occupational engagement opportunities. A non-traditional dementia facility maximises these opportunities and can support development of best-practice guidelines within this population. © 2015 Occupational Therapy Australia.

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

Science.gov (United States)

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

Science.gov (United States)

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.

Science.gov (United States)

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

2016-03-30

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

Guild Hall retrofit

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.

Anonymity and Electronics: Adapting Preparation for Radiology Resident Examination.

Science.gov (United States)

Chapman, Teresa; Reid, Janet R; O'Conner, Erin E

2017-06-01

Diagnostic radiology resident assessment has evolved from a traditional oral examination to computerized testing. Teaching faculty struggle to reconcile the differences between traditional teaching methods and residents' new preferences for computerized testing models generated by new examination styles. We aim to summarize the collective experiences of senior residents at three different teaching hospitals who participated in case review sessions using a computer-based, interactive, anonymous teaching tool, rather than the Socratic method. Feedback was collected from radiology residents following participation in a senior resident case review session using Nearpod, which allows residents to anonymously respond to the teaching material. Subjective resident feedback was uniformly enthusiastic. Ninety percent of residents favor a case-based board review incorporating multiple-choice questions, and 94% favor an anonymous response system. Nearpod allows for inclusion of multiple-choice questions while also providing direct feedback to the teaching faculty, helping to direct the instruction and clarify residents' gaps in knowledge before the Core Examination. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Laurance David Hall.

Science.gov (United States)

Coxon, Bruce

2011-01-01

An account is given of the life, scientific contributions, and passing of Laurance David Hall (1938-2009), including his early history and education at the University of Bristol, UK, and the synthesis and NMR spectroscopy of carbohydrates and other natural products during ∼20 years of research and teaching at the University of British Columbia in Vancouver, Canada. Lists of graduate students, post-doctoral fellows, and sabbatical visitors are provided for this period. Following a generous endowment by Dr. Herchel Smith, Professor Hall built a new Department of Medicinal Chemistry at Cambridge University, UK, and greatly expanded his researches into the technology and applications of magnetic resonance imaging (MRI) and zero quantum NMR. MRI technology was applied both to medical problems such as the characterization of cartilage degeneration in knee joints, the measurement of ventricular function, lipid localization in animal models of atherosclerosis, paramagnetic metal complexes of polysaccharides as contrast agents, and studies of many other anatomical features, but also to several aspects of materials analysis, including food analyses, process control, and the elucidation of such physical phenomena as the flow of liquids through porous media, defects in concrete, and the visualization of fungal damage to wood. Professor Hall's many publications, patents, lectures, and honors and awards are described, and also his successful effort to keep the Asilomar facility in Pacific Grove, California as the alternating venue for the annual Experimental NMR Conference. Two memorial services for Professor Hall are remembered. Copyright © 2011 Elsevier Inc. All rights reserved.

Simulation-based education with mastery learning improves residents' lumbar puncture skills

Science.gov (United States)

Cohen, Elaine R.; Caprio, Timothy; McGaghie, William C.; Simuni, Tanya; Wayne, Diane B.

2012-01-01

Objective: To evaluate the effect of simulation-based mastery learning (SBML) on internal medicine residents' lumbar puncture (LP) skills, assess neurology residents' acquired LP skills from traditional clinical education, and compare the results of SBML to traditional clinical education. Methods: This study was a pretest-posttest design with a comparison group. Fifty-eight postgraduate year (PGY) 1 internal medicine residents received an SBML intervention in LP. Residents completed a baseline skill assessment (pretest) using a 21-item LP checklist. After a 3-hour session featuring deliberate practice and feedback, residents completed a posttest and were expected to meet or exceed a minimum passing score (MPS) set by an expert panel. Simulator-trained residents' pretest and posttest scores were compared to assess the impact of the intervention. Thirty-six PGY2, 3, and 4 neurology residents from 3 medical centers completed the same simulated LP assessment without SBML. SBML posttest scores were compared to neurology residents' baseline scores. Results: PGY1 internal medicine residents improved from a mean of 46.3% to 95.7% after SBML (p < 0.001) and all met the MPS at final posttest. The performance of traditionally trained neurology residents was significantly lower than simulator-trained residents (mean 65.4%, p < 0.001) and only 6% met the MPS. Conclusions: Residents who completed SBML showed significant improvement in LP procedural skills. Few neurology residents were competent to perform a simulated LP despite clinical experience with the procedure. PMID:22675080

The Other Hall Effect: College Board Physics

Science.gov (United States)

Sheppard, Keith; Gunning, Amanda M.

2013-01-01

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

Anomalous Hall effect in polycrystalline Ni films

KAUST Repository

Guo, Zaibing

2012-02-01

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

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.

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)

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

Science.gov (United States)

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

2016-05-17

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

The quantum hall effect

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

Paired Hall states

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

A comparison of simulation-based education versus lecture-based instruction for toxicology training in emergency medicine residents.

Science.gov (United States)

Maddry, Joseph K; Varney, Shawn M; Sessions, Daniel; Heard, Kennon; Thaxton, Robert E; Ganem, Victoria J; Zarzabal, Lee A; Bebarta, Vikhyat S

2014-12-01

Simulation-based teaching (SIM) is a common method for medical education. SIM exposes residents to uncommon scenarios that require critical, timely actions. SIM may be a valuable training method for critically ill poisoned patients whose diagnosis and treatment depend on key clinical findings. Our objective was to compare medical simulation (SIM) to traditional lecture-based instruction (LEC) for training emergency medicine (EM) residents in the acute management of critically ill poisoned patients. EM residents completed two pre-intervention questionnaires: (1) a 24-item multiple-choice test of four toxicological emergencies and (2) a questionnaire using a five-point Likert scale to rate the residents' comfort level in diagnosing and treating patients with specific toxicological emergencies. After completing the pre-intervention questionnaires, residents were randomized to SIM or LEC instruction. Two toxicologists and three EM physicians presented four toxicology topics to both groups in four 20-min sessions. One group was in the simulation center, and the other in a lecture hall. Each group then repeated the multiple-choice test and questionnaire immediately after instruction and again at 3 months after training. Answers were not discussed. The primary outcome was comparison of immediate mean post-intervention test scores and final scores 3 months later between SIM and LEC groups. Test score outcomes between groups were compared at each time point (pre-test, post-instruction, 3-month follow-up) using Wilcoxon rank sum test. Data were summarized by descriptive statistics. Continuous variables were characterized by means (SD) and tested using t tests or Wilcoxon rank sum. Categorical variables were summarized by frequencies (%) and compared between training groups with chi-square or Fisher's exact test. Thirty-two EM residents completed pre- and post-intervention tests and comfort questionnaires on the study day. Both groups had higher post-intervention mean test

Dr. Hall and the work cure.

Science.gov (United States)

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 simulation Model of the Reactor Hall Ventilation and air Conditioning Systems of ETRR-2

International Nuclear Information System (INIS)

Abd El-Rahman, M.F.

2004-01-01

Although the conceptual design for any system differs from one designer to another. each of them aims to achieve the function of the system required. the ventilation and air conditioning system of reactors hall is one of those systems that really differs but always dose its function for which it is designed. thus, ventilation and air conditioning in some reactor hall constitute only one system whereas in some other ones, they are separate systems. the Egypt Research Reactor-2 (ETRR-2)represents the second type. most studies conducted on ventilation and air conditioning simulation models either in traditional building or for research rectors show that those models were not designed similarly to the model of the hall of ETRR-2 in which ventilation and air conditioning constitute two separate systems.besides, those studies experimented on ventilation and air conditioning simulation models of reactor building predict the temperature and humidity inside these buildings at certain outside condition and it is difficult to predict when the outside conditions are changed . also those studies do not discuss the influences of reactor power changes. therefore, the present work deals with a computational study backed by infield experimental measurements of the performance of the ventilation and air conditioning systems of reactor hall during normal operation at different outside conditions as well as at different levels of reactor power

The Effectiveness of Hypermedia Instructional Modules for Radiology Residents.

Science.gov (United States)

Shaw, Steven G.; And Others

1995-01-01

Details the development and field testing of hypermedia training materials for teaching radiology residents at the Montreal General Hospital (Canada). Compares results of randomly teaching 24 residents with either hypermedia or traditional classroom methods. Results indicate that residents who learned with hypermedia generally performed as well as…

Resident response to integration of simulation-based education into emergency medicine conference.

Science.gov (United States)

Wang, Ernest E; Beaumont, Jennifer; Kharasch, Morris; Vozenilek, John A

2008-11-01

Utilization of simulation-based training has become increasingly prevalent in residency training. The authors compared emergency medicine (EM) resident feedback for simulation sessions to traditional lectures from an EM residency didactic program. The authors performed a retrospective review of all written EM conference evaluations over a 29-month period. Evaluation questions were scored on a 1-9 Likert scale. Lectures and simulation accounted for 77.6 and 22.4% of the conferences, respectively. Scored means (+/-standard deviations [SDs]) were as follows: overall, lecture 7.97 +/- 0.74 versus simulation 8.373 +/- 0.44 (p higher than traditional lectures. The scores over time suggest that this preference for simulation can be sustainable long term. Residents perceive simulation as more desirable teaching method compared to the traditional lecture format.

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 ...

Spin hall effect associated with SU(2) gauge field

Science.gov (United States)

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.

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 quantized Hall effect

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

Valley-chiral quantum Hall state in graphene superlattice structure

Science.gov (United States)

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.

Air temperature gradient in large industrial hall

Science.gov (United States)

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.

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.)

The quantum Hall effects: Philosophical approach

Science.gov (United States)

Lederer, P.

2015-05-01

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

Quantum critical Hall exponents

CERN Document Server

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...

Hall devices improve electric motor efficiency

Science.gov (United States)

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.

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...

Unconventional quantum Hall effect in Floquet topological insulators

KAUST Repository

Tahir, M.

2016-07-27

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

Unconventional quantum Hall effect in Floquet topological insulators

KAUST Repository

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.

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 × 430 ¿m2, and the probe pitches range from 20 ¿m to 50 ¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...

Extrinsic spin Hall effect in graphene

Science.gov (United States)

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.

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

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

Spin-singlet hierarchy in the fractional quantum Hall effect

OpenAIRE

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 $\

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)

Surface and 3D Quantum Hall Effects from Engineering of Exceptional Points in Nodal-Line Semimetals

Science.gov (United States)

Molina, Rafael A.; González, José

2018-04-01

We show that, under a strong magnetic field, a 3D nodal-line semimetal is driven into a topological insulating phase in which the electronic transport takes place at the surface of the material. When the magnetic field is perpendicular to the nodal ring, the surface states of the semimetal are transmuted into Landau states which correspond to exceptional points, i.e., branch points in the spectrum of a non-Hermitian Hamiltonian which arise upon the extension to complex values of the momentum. The complex structure of the spectrum then allows us to express the number of zero-energy flat bands in terms of a new topological invariant counting the number of exceptional points. When the magnetic field is parallel to the nodal ring, we find that the bulk states are built from the pairing of surfacelike evanescent waves, giving rise to a 3D quantum Hall effect with a flat level of Landau states residing in parallel 2D slices of the 3D material. The Hall conductance is quantized in either case in units of e2/h , leading in the 3D Hall effect to a number of channels growing linearly with the section of the surface and opening the possibility to observe a macroscopic chiral current at the surface of the material.

The Hall module of an exact category with duality

OpenAIRE

Young, Matthew B.

2012-01-01

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

Theory of spin Hall effect

OpenAIRE

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...

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

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

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

Curricula and Organization of Primary Care Residencies in Internal Medicine.

Science.gov (United States)

Eisenberg, John M.

1980-01-01

The organization and curricula of internal medicine residencies programs that emphasize primary care are described and compared with traditional residencies in internal medicine. It is noted that primary care residents spend more time in ambulatory care and are allowed more electives in specialties outside of internal medicine. Out-of-hospital…

Results of a Flipped Classroom Teaching Approach in Anesthesiology Residents.

Science.gov (United States)

Martinelli, Susan M; Chen, Fei; DiLorenzo, Amy N; Mayer, David C; Fairbanks, Stacy; Moran, Kenneth; Ku, Cindy; Mitchell, John D; Bowe, Edwin A; Royal, Kenneth D; Hendrickse, Adrian; VanDyke, Kenneth; Trawicki, Michael C; Rankin, Demicha; Guldan, George J; Hand, Will; Gallagher, Christopher; Jacob, Zvi; Zvara, David A; McEvoy, Matthew D; Schell, Randall M

2017-08-01

In a flipped classroom approach, learners view educational content prior to class and engage in active learning during didactic sessions. We hypothesized that a flipped classroom improves knowledge acquisition and retention for residents compared to traditional lecture, and that residents prefer this approach. We completed 2 iterations of a study in 2014 and 2015. Institutions were assigned to either flipped classroom or traditional lecture for 4 weekly sessions. The flipped classroom consisted of reviewing a 15-minute video, followed by 45-minute in-class interactive sessions with audience response questions, think-pair-share questions, and case discussions. The traditional lecture approach consisted of a 55-minute lecture given by faculty with 5 minutes for questions. Residents completed 3 knowledge tests (pretest, posttest, and 4-month retention) and surveys of their perceptions of the didactic sessions. A linear mixed model was used to compare the effect of both formats on knowledge acquisition and retention. Of 182 eligible postgraduate year 2 anesthesiology residents, 155 (85%) participated in the entire intervention, and 142 (78%) completed all tests. The flipped classroom approach improved knowledge retention after 4 months (adjusted mean = 6%; P  = .014; d  = 0.56), and residents preferred the flipped classroom (pre = 46%; post = 82%; P  flipped classroom approach to didactic education resulted in a small improvement in knowledge retention and was preferred by anesthesiology residents.

Commemorative Symposium on the Hall Effect and its Applications

CERN Document Server

Westgate, C

1980-01-01

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

A novel adjuvant to the resident selection process: the hartman value profile.

Science.gov (United States)

Cone, Jeffrey D; Byrum, C Stephen; Payne, Wyatt G; Smith, David J

2012-01-01

The goal of resident selection is twofold: (1) select candidates who will be successful residents and eventually successful practitioners and (2) avoid selecting candidates who will be unsuccessful residents and/or eventually unsuccessful practitioners. Traditional tools used to select residents have well-known limitations. The Hartman Value Profile (HVP) is a proven adjuvant tool to predicting future performance in candidates for advanced positions in the corporate setting. No literature exists to indicate use of the HVP for resident selection. The HVP evaluates the structure and the dynamics of an individual value system. Given the potential impact, we implemented its use beginning in 2007 as an adjuvant tool to the traditional selection process. Experience gained from incorporating the HVP into the residency selection process suggests that it may add objectivity and refinement in predicting resident performance. Further evaluation is warranted with longer follow-up times.

Halls Lake 1990

Data.gov (United States)

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

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

Intrinsic superspin Hall current

Science.gov (United States)

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.

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)

Spontaneous Hall effect in a chiral p-wave superconductor

Science.gov (United States)

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.

Anomalous Hall effect in Fe/Gd bilayers

KAUST Repository

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

Anomalous Hall effect in Fe/Gd bilayers

KAUST Repository

Xu, W. J.

2010-04-01

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

Anomalous Hall effect

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

Hall effect in a strong magnetic field: Direct comparisons of compressible magnetohydrodynamics and the reduced Hall magnetohydrodynamic equations

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.

Measured Early Lateral Energy Fractions in Concert Halls and Opera Houses

Science.gov (United States)

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.

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

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)

Intrinsic quantum spin Hall and anomalous Hall effects in h-Sb/Bi epitaxial growth on a ferromagnetic MnO2 thin film.

Science.gov (United States)

Zhou, Jian; Sun, Qiang; Wang, Qian; Kawazoe, Yoshiyuki; Jena, Puru

2016-06-07

Exploring a two-dimensional intrinsic quantum spin Hall state with a large band gap as well as an anomalous Hall state in realizable materials is one of the most fundamental and important goals for future applications in spintronics, valleytronics, and quantum computing. Here, by combining first-principles calculations with a tight-binding model, we predict that Sb or Bi can epitaxially grow on a stable and ferromagnetic MnO2 thin film substrate, forming a flat honeycomb sheet. The flatness of Sb or Bi provides an opportunity for the existence of Dirac points in the Brillouin zone, with its position effectively tuned by surface hydrogenation. The Dirac points in spin up and spin down channels split due to the proximity effects induced by MnO2. In the presence of both intrinsic and Rashba spin-orbit coupling, we find two band gaps exhibiting a large band gap quantum spin Hall state and a nearly quantized anomalous Hall state which can be tuned by adjusting the Fermi level. Our findings provide an efficient way to realize both quantized intrinsic spin Hall conductivity and anomalous Hall conductivity in a single material.

Plasmon Geometric Phase and Plasmon Hall Shift

Science.gov (United States)

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.

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

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.

Spin disorder effect in anomalous Hall effect in MnGa

Science.gov (United States)

Mendonça, A. P. A.; Varalda, J.; Schreiner, W. H.; Mosca, D. H.

2017-12-01

We report on resistivity and Hall effect in MnGa thin films grown by molecular beam epitaxy on GaAs substrates. Highly (1 1 1)-textured MnGa film with L10 structure exhibits hard magnetic properties with coercivities as high as 20 kOe and spin disorder mechanisms contributing to the Hall conductivity at room temperature. Density functional theory calculations were performed to determine the intrinsic Berry curvature in the momentum space with chiral spin structure that results in an anomalous Hall conductivity of 127 (Ωcm)-1 comparable to that measured at low temperature. In addition to residual and side-jump contributions, which are enhanced by thermal activation, both anomalous Hall conductivity and Hall angle increase between 100 K and room temperature. The present results reinforce the potential of Mn-Ga system for developing Hall effect-based spintronic devices.

Development of a novel sports medicine rotation for emergency medicine residents.

Science.gov (United States)

Waterbrook, Anna L; Pritchard, T Gail; Lane, Allison D; Stoneking, Lisa R; Koch, Bryna; McAtee, Robert; Grall, Kristi H; Min, Alice A; Prior, Jessica; Farrell, Isaac; McNulty, Holly G; Stolz, Uwe

2016-01-01

Musculoskeletal complaints are the most common reason for patients to visit a physician, yet competency in musculoskeletal medicine is invariably reported as a deficiency in medical education in the USA. Sports medicine clinical rotations improve both medical students' and residents' musculoskeletal knowledge. Despite the importance of this knowledge, a standardized sports medicine curriculum in emergency medicine (EM) does not exist. Hence, we developed a novel sports medicine rotation for EM residents to improve their musculoskeletal educational experience and to improve their knowledge in musculoskeletal medicine by teaching the evaluation and management of many common musculoskeletal disorders and injuries that are encountered in the emergency department. The University of Arizona has two distinct EM residency programs, South Campus (SC) and University Campus (UC). The UC curriculum includes a traditional 4-week orthopedic rotation, which consistently rated poorly on evaluations by residents. Therefore, with the initiation of a new EM residency at SC, we replaced the standard orthopedic rotation with a novel sports medicine rotation for EM interns. This rotation includes attendance at sports medicine clinics with primary care and orthopedic sports medicine physicians, involvement in sport event coverage, assigned reading materials, didactic experiences, and an on-call schedule to assist with reductions in the emergency department. We analyzed postrotation surveys completed by residents, postrotation evaluations of the residents completed by primary care sports medicine faculty and orthopedic chief residents, as well as the total number of dislocation reductions performed by each graduating resident at both programs over the last 5 years. While all residents in both programs exceeded the ten dislocation reductions required for graduation, residents on the sports medicine rotation had a statistically significant higher rate of satisfaction of their educational

L'effet Hall Quantique

Science.gov (United States)

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

Piezo Voltage Controlled Planar Hall Effect Devices.

Science.gov (United States)

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

2016-06-22

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

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)

Experimental test of 200 W Hall thruster with titanium wall

Science.gov (United States)

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.

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)

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.

Magnesium Hall Thruster

Science.gov (United States)

Szabo, James J.

2015-01-01

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

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...

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.

Tunnelling anomalous and planar Hall effects (Conference Presentation)

Science.gov (United States)

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

2016-10-01

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

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

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...

Media education in pediatric residencies: a national survey.

Science.gov (United States)

Christakis, Dimitri A; Frintner, Mary Pat; Mulligan, Deborah A; Fuld, Gilbert L; Olson, Lynn M

2013-01-01

Little is known about the current state of residency education with respect to counseling parents about media usage and whether trainees consider it to be adequate. A national survey of graduating pediatric residents was conducted in the United States to determine the amount of training they receive on traditional and new media, their perceptions of its quality, and their self-reported practices regarding talking to families about media usage. A 58% response rate was achieved with no evidence of response bias based on age or gender. Only 38% rated their residency program as "very good" or "excellent" in preparing them to provide anticipatory guidance on the effects of media on children and adolescents. In logistic regression analyses, controlling for demographic characteristics, more training on media issues was a significant predictor for usually/always advising families on traditional, passive media (adjusted odds ratio = 3.29; 95% confidence interval 2.26-4.81) and usually/always advising families on new, interactive media use (adjusted odds ratio = 3.96; 95% confidence interval 2.61-6.00) during well-child visits. The majority of residents believe their training on children in media is inadequate. Enhanced training on media is needed in US pediatric residencies. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Evaluation of Problem- and Simulator-Based Learning in Lumbar Puncture in Adult Neurology Residency Training.

Science.gov (United States)

Sun, Chenjing; Qi, Xiaokun

2018-01-01

Lumbar puncture (LP) is an essential part of adult neurology residency training. Technologic as well as nontechnologic training is needed. However, current assessment tools mostly focus on the technologic aspects of LP. We propose a training method-problem- and simulator-based learning (PSBL)-in LP residency training to develop overall skills of neurology residents. We enrolled 60 neurology postgraduate-year-1 residents from our standardized residents training center and randomly divided them into 2 groups: traditional teaching group and PSBL group. After training, we assessed the extent that the residents were ready to perform LP and tracked successful LPs performed by the residents. We then asked residents to complete questionnaires about the training models. Performance scores and the results of questionnaires were compared between the 2 groups. Students and faculty concluded that PSBL provided a more effective learning experience than the traditional teaching model. Although no statistical difference was found in the pretest, posttest, and improvement rate scores between the 2 groups, based on questionnaire scores and number of successful LPs after training, the PSBL group showed a statistically significant improvement compared with the traditional group. Findings indicated that nontechnical elements, such as planning before the procedure and controlling uncertainties during the procedure, are more crucial than technical elements. Compared with traditional teaching model, PSBL for LP training can develop overall surgical skills, including technical and nontechnical elements, improving performance. Residents in the PSBL group were more confident and effective in performing LP. Copyright © 2017 Elsevier Inc. All rights reserved.

Localization in a quantum spin Hall system.

Science.gov (United States)

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.

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.

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

Science.gov (United States)

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.

NAS Decadal Review Town Hall

Science.gov (United States)

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.

Quantum Hall Ferroelectrics and Nematics in Multivalley Systems

Science.gov (United States)

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.

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.

Digital technology impacts on the Arnhem transfer hall structural design

NARCIS (Netherlands)

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

2015-01-01

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

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...

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

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.

Diagnostics Systems for Permanent Hall Thrusters Development

Science.gov (United States)

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

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

Hole mobilities and the effective Hall factor in p-type GaAs

Science.gov (United States)

Wenzel, M.; Irmer, G.; Monecke, J.; Siegel, W.

1997-06-01

We prove the effective Hall factor in p-GaAs to be larger than values discussed in the literature up to now. The scattering rates for the relevant scattering mechanisms in p-GaAs have been recalculated after critical testing the existing models. These calculations allow to deduce theoretical drift and theoretical Hall mobilities as functions of temperature which can be compared with measured data. Theoretical Hall factors in the heavy and light hole bands and an effective Hall factor result. The calculated room temperature values of the drift mobility and of the effective Hall factor are 118 cm2/V s and 3.6, respectively. The fitted acoustic deformation potential E1=7.9 eV and the fitted optical coupling constant DK=1.24×1011 eV/m are close to values published before. It is shown that the measured strong dependence of the Hall mobility on the Hall concentration is not mainly caused by scattering by ionized impurities but by the dependence of the effective Hall factor on the hole concentration.

Resident Perception of Technical Skills Education and Preparation for Independent Practice.

Science.gov (United States)

Odell, David D; Macke, Ryan A; Tchantchaleishvili, Vakhtang; Loor, Gabriel; Nelson, Jennifer S; LaPar, Damien J; LaZar, John F; Wei, Benjamin; DeNino, Walter F; Berfield, Kathleen; Stein, William; Youssef, Samuel J; Nguyen, Tom C

2015-12-01

Surgical skills are traditionally taught and practiced in the operating room. However, changes in health care policy and outcome-based evaluation have decreased trainee operative autonomy. We examined cardiothoracic residents' perceptions of operative experience and the role of simulation. The In-Training Examination (ITE) is taken each year by all residents. Completion of a 30-question preexamination survey is mandatory, ensuring a 100% response rate. Survey data related to operative experience, career preparedness, and surgical simulation were analyzed. Opinion questions were asked on a 5-point Likert scale. Respondents were grouped into three cohorts by training paradigm (2-year versus 3-year traditional programs and 6-year integrated programs). In all, 314 respondents (122 2-year, 96 3-year, and 96 6-year integrated) completed the survey. Of the three groups, residents in 3-year programs had the highest levels of satisfaction. Advanced training was most common among residents in 6-year integrated programs (66%, versus 49% for 2-year and 26% for 3-year programs; p = 0.63). Desire to specialize drove further training (97%), with 2% stating further training was needed owing to inadequacy and 1% owing to a poor job market. In all assessed categories, the majority of residents believed that simulation did not completely replicate the educational value of an operative case. Cardiothoracic residents largely feel well prepared for the transition to practice under the current educational paradigm. Although many residents seek advanced training, it seems driven by the desire for specialization. Residents view simulation as an adjunct to traditional intraoperative education, but not as a viable replacement. Further study is necessary to better understand how best to integrate simulation with operative experience. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

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

Are quantum spin Hall edge modes more resilient to disorder, sample geometry and inelastic scattering than quantum Hall edge modes?

Science.gov (United States)

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.

Are quantum spin Hall edge modes more resilient to disorder, sample geometry and inelastic scattering than quantum Hall edge modes?

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)

Performance Comparison of Cross-Like Hall Plates with Different Covering Layers

Directory of Open Access Journals (Sweden)

Fei Lyu

2014-12-01

Full Text Available This paper studies the effects of the covering layers on the performance of a cross-like Hall plate. Three different structures of a cross-like Hall plate in various sizes are designed and analyzed. The Hall plate sensitivity and offset are characterized using a self-built measurement system. The effect of the P-type region over the active area on the current-related sensitivity is studied for different Hall plate designs. In addition, the correlation between the P-type covering layer and offset is analyzed. The best structure out of three designs is determined. Besides, a modified eight-resistor circuit model for the Hall plate is presented with improved accuracy by taking the offset into account.

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

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)

Competencies "plus": the nature of written comments on internal medicine residents' evaluation forms.

Science.gov (United States)

Ginsburg, Shiphra; Gold, Wayne; Cavalcanti, Rodrigo B; Kurabi, Bochra; McDonald-Blumer, Heather

2011-10-01

Comments on residents' in-training evaluation reports (ITERs) may be more useful than scores in identifying trainees in difficulty. However, little is known about the nature of comments written by internal medicine faculty on residents' ITERs. Comments on 1,770 ITERs (from 180 residents in postgraduate years 1-3) were analyzed using constructivist grounded theory beginning with an existing framework. Ninety-three percent of ITERs contained comments, which were frequently easy to map onto traditional competencies, such as knowledge base (n = 1,075 comments) to the CanMEDs Medical Expert role. Many comments, however, could be linked to several overlapping competencies. Also common were comments completely unrelated to competencies, for instance, the resident's impact on staff (813), or personality issues (450). Residents' "trajectory" was a major theme (performance in relation to expected norms [494], improvement seen [286], or future predictions [286]). Faculty's assessments of residents are underpinned by factors related and unrelated to traditional competencies. Future evaluations should attempt to capture these holistic, integrated impressions.

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.

Hospital Medicine Resident Training Tracks: Developing the Hospital Medicine Pipeline.

Science.gov (United States)

Sweigart, Joseph R; Tad-Y, Darlene; Kneeland, Patrick; Williams, Mark V; Glasheen, Jeffrey J

2017-03-01

Hospital medicine (HM) is rapidly evolving into new clinical and nonclinical roles. Traditional internal medicine (IM) residency training likely does not optimally prepare residents for success in HM. Hospital medicine residency training tracks may offer a preferred method for specialized HM education. Internet searches and professional networks were used to identify HM training tracks. Information was gathered from program websites and discussions with track directors. The 11 HM tracks at academic medical centers across the United States focus mostly on senior residents. Track structure and curricular content are determined largely by the structure and curricula of the IM residency programs in which they exist. Almost all tracks feature experiential quality improvement projects. Content on healthcare economics and value is common, and numerous track leaders report this content is expanding from HM tracks into entire residency programs. Tracks also provide opportunities for scholarship and professional development, such as workshops on abstract creation and job procurement skills. Almost all tracks include HM preceptorships as well as rotations within various disciplines of HM. HM residency training tracks focus largely on quality improvement, health care economics, and professional development. The structures and curricula of these tracks are tightly linked to opportunities within IM residency programs. As HM continues to evolve, these tracks likely will expand to bridge clinical and extra-clinical gaps between traditional IM training and contemporary HM practice. Journal of Hospital Medicine 2017;12:173-176. © 2017 Society of Hospital Medicine

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)

Hall conductance and topological invariant for open systems.

Science.gov (United States)

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

2014-09-24

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

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.

Fast surface waves in an ideal Hall-magnetohydrodynamic plasma slab

International Nuclear Information System (INIS)

Zhelyazkov, I.; Debosscher, A.; Goossens, M.

1996-01-01

The propagation of fast sausage and kink magnetohydrodynamic (MHD) surface waves in an ideal magnetized plasma slab is studied taking into account the Hall term in the generalized Ohm close-quote s law. It is found that the Hall effect modifies the dispersion characteristics of MHD surface modes when the Hall term scaling length is not negligible (less than, but comparable to the slab thickness). The dispersion relations for both modes have been derived for parallel propagation (along the ambient equilibrium magnetic field lines).The Hall term imposes some limits on the possible wave number range. It turns out that the space distribution of almost all perturbed quantities in sausage and kink surface waves with Hall effect is rather complicated as compared to that of usual fast MHD surface waves. The applicability to solar wind aspects of the results obtained, is briefly discussed. copyright 1996 American Institute of Physics

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

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)

Emergency Medicine Resident Perceptions of Medical Professionalism.

Science.gov (United States)

Jauregui, Joshua; Gatewood, Medley O; Ilgen, Jonathan S; Schaninger, Caitlin; Strote, Jared

2016-05-01

Medical professionalism is a core competency for emergency medicine (EM) trainees; but defining professionalism remains challenging, leading to difficulties creating objectives and performing assessment. Because professionalism is dynamic, culture-specific, and often taught by modeling, an exploration of trainees' perceptions can highlight their educational baseline and elucidate the importance they place on general conventional professionalism domains. To this end, our objective was to assess the relative value EM residents place on traditional components of professionalism. We performed a cross-sectional, multi-institutional survey of incoming and graduating EM residents at four programs. The survey was developed using the American Board of Internal Medicine's "Project Professionalism" and the Accreditation Council of Graduate Medical Education definition of professionalism competency. We identified 27 attributes within seven domains: clinical excellence, humanism, accountability, altruism, duty and service, honor and integrity, and respect for others. Residents were asked to rate each attribute on a 10-point scale. We analyzed data to assess variance across attributes as well as differences between residents at different training levels or different institutions. Of the 114 residents eligible, 100 (88%) completed the survey. The relative value assigned to different professional attributes varied considerably, with those in the altruism domain valued significantly lower and those in the "respect for others" and "honor and integrity" valued significantly higher (p<0.001). Significant differences were found between interns and seniors for five attributes primarily in the "duty and service" domain (p<0.05). Among different residencies, significant differences were found with attributes within the "altruism" and "duty and service" domains (p<0.05). Residents perceive differences in the relative importance of traditionally defined professional attributes and this may

Emergency Medicine Resident Perceptions of Medical Professionalism

Directory of Open Access Journals (Sweden)

Joshua Jauregui

2016-05-01

Full Text Available Introduction: Medical professionalism is a core competency for emergency medicine (EM trainees; but defining professionalism remains challenging, leading to difficulties creating objectives and performing assessment. Because professionalism is dynamic, culture-specific, and often taught by modeling, an exploration of trainees’ perceptions can highlight their educational baseline and elucidate the importance they place on general conventional professionalism domains. To this end, our objective was to assess the relative value EM residents place on traditional components of professionalism. Methods: We performed a cross-sectional, multi-institutional survey of incoming and graduating EM residents at four programs. The survey was developed using the American Board of Internal Medicine’s “Project Professionalism” and the Accreditation Council of Graduate Medical Education definition of professionalism competency. We identified 27 attributes within seven domains: clinical excellence, humanism, accountability, altruism, duty and service, honor and integrity, and respect for others. Residents were asked to rate each attribute on a 10-point scale. We analyzed data to assess variance across attributes as well as differences between residents at different training levels or different institutions. Results: Of the 114 residents eligible, 100 (88% completed the survey. The relative value assigned to different professional attributes varied considerably, with those in the altruism domain valued significantly lower and those in the “respect for others” and “honor and integrity” valued significantly higher (p<0.001. Significant differences were found between interns and seniors for five attributes primarily in the “duty and service” domain (p<0.05. Among different residencies, significant differences were found with attributes within the “altruism” and “duty and service” domains (p<0.05. Conclusion: Residents perceive differences in

Virtual alternative to the oral examination for emergency medicine residents.

Science.gov (United States)

McGrath, Jillian; Kman, Nicholas; Danforth, Douglas; Bahner, David P; Khandelwal, Sorabh; Martin, Daniel R; Nagel, Rollin; Verbeck, Nicole; Way, David P; Nelson, Richard

2015-03-01

The oral examination is a traditional method for assessing the developing physician's medical knowledge, clinical reasoning and interpersonal skills. The typical oral examination is a face-to-face encounter in which examiners quiz examinees on how they would confront a patient case. The advantage of the oral exam is that the examiner can adapt questions to the examinee's response. The disadvantage is the potential for examiner bias and intimidation. Computer-based virtual simulation technology has been widely used in the gaming industry. We wondered whether virtual simulation could serve as a practical format for delivery of an oral examination. For this project, we compared the attitudes and performance of emergency medicine (EM) residents who took our traditional oral exam to those who took the exam using virtual simulation. EM residents (n=35) were randomized to a traditional oral examination format (n=17) or a simulated virtual examination format (n=18) conducted within an immersive learning environment, Second Life (SL). Proctors scored residents using the American Board of Emergency Medicine oral examination assessment instruments, which included execution of critical actions and ratings on eight competency categories (1-8 scale). Study participants were also surveyed about their oral examination experience. We observed no differences between virtual and traditional groups on critical action scores or scores on eight competency categories. However, we noted moderate effect sizes favoring the Second Life group on the clinical competence score. Examinees from both groups thought that their assessment was realistic, fair, objective, and efficient. Examinees from the virtual group reported a preference for the virtual format and felt that the format was less intimidating. The virtual simulated oral examination was shown to be a feasible alternative to the traditional oral examination format for assessing EM residents. Virtual environments for oral examinations

A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics.

Science.gov (United States)

Huang, Haiyun; Wang, Dejun; Xu, Yue

2015-10-27

This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS) technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW.

A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics

Directory of Open Access Journals (Sweden)

Haiyun Huang

2015-10-01

Full Text Available This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW.

The ISOLDE hall

CERN Multimedia

Maximilien Brice

2002-01-01

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

Medical humanities: a resident doctor's perspective.

Science.gov (United States)

Pauranik, Anvita

2012-01-01

The barrage of competitive examinations, overwork, sleep deprivation, and the pressure of expectations all combine to destroy the dreams that resident doctors have when they start medical school. The empathy they had before entering this field fades away, and they eventually become insensitive to their patients. Medical humanities may be the means to halt this trend. Sensitising young minds, using the arts, literature, history and lessons on social issues, may bring about a paradigm shift in these doctors' outlook towards their patients. However, for the humanities to be integrated into medical education, the current curriculum must be modified and made more clinically and socially relevant. Further, the humanities cannot be taught in lecture halls; they need to be integrated into all aspects of medical school. For this, the medical school faculty should be sensitised to, and trained in, humanities education.

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.

Proton knock-out in Hall A

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.)

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 ...

G. Stanley Hall, Child Study, and the American Public.

Science.gov (United States)

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.

Four-dimensional Hall mechanics as a particle on CP3

International Nuclear Information System (INIS)

Bellucci, Stefano; Casteill, Pierre-Yves; Nersessian, Armen

2003-01-01

In order to establish an explicit connection between four-dimensional Hall effect on S 4 and six-dimensional Hall effect on CP 3 , we perform the Hamiltonian reduction of a particle moving on CP 3 in a constant magnetic field to the four-dimensional Hall mechanics (i.e., a-bar particle on S 4 in a SU(2) instanton field). This reduction corresponds to fixing the isospin of the latter system

Spin Hall Effect in Doped Semiconductor Structures

Science.gov (United States)

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.

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.

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.

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

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

Pediatric resident perceptions of shift work in ward rotations.

Science.gov (United States)

Nomura, Osamu; Mishina, Hiroki; Jasti, Harish; Sakai, Hirokazu; Ishiguro, Akira

2017-10-01

Although the long working hours of physicians are considered to be a social issue, no effective policies such as duty hour regulations have so far been proposed in Japan. We implemented an overnight call shift (OCS) system for ward rotations to improve the working environment for residents in a pediatric residency program. We later conducted a cross-sectional questionnaire asking the residents to compare this system with the traditional overnight call system. Forty-one pediatric residents participated in this survey. The residents felt that the quality of patient care improved (80.4% agreed). Most felt that there was less emphasis on education (26.8%) and more emphasis on service (31.7%). Overall, the residents reported that the OCS was beneficial (90.2%). In conclusion, the pediatric residents considered the OCS system during ward rotations as beneficial. Alternative solutions are vital to balance improvements in resident work conditions with the requirement for a high quality of education. © 2017 Japan Pediatric Society.

Literature Review of Residents as Teachers from an Adult Learning Perspective

Science.gov (United States)

Blanchard, Rebecca D.; Hinchey, Kevin T.; Bennett, Elisabeth E.

2011-01-01

Academic medical centers represent the intersection of higher education and workforce development. However residents often utilize traditional pedagogical approaches learned from higher education settings that fail to translate with adult learners. The purpose of this study is to synthesize literature on resident teachers from the perspective of…

The Isolde experimental hall

CERN Multimedia

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.

Bulk Versus Edge in the Quantum Hall Effect

OpenAIRE

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

1996-01-01

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

An evaluation of krypton propellant in Hall thrusters

Science.gov (United States)

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

Magnetic field deformation due to electron drift in a Hall thruster

Directory of Open Access Journals (Sweden)

Han Liang

2017-01-01

Full Text Available The strength and shape of the magnetic field are the core factors in the design of the Hall thruster. However, Hall current can affect the distribution of static magnetic field. In this paper, the Particle-In-Cell (PIC method is used to obtain the distribution of Hall current in the discharge channel. The Hall current is separated into a direct and an alternating part to calculate the induced magnetic field using Finite Element Method Magnetics (FEMM. The results show that the direct Hall current decreases the magnetic field strength in the acceleration region and also changes the shape of the magnetic field. The maximum reduction in radial magnetic field strength in the exit plane is 10.8 G for an anode flow rate of 15 mg/s and the maximum angle change of the magnetic field line is close to 3° in the acceleration region. The alternating Hall current induces an oscillating magnetic field in the whole discharge channel. The actual magnetic deformation is shown to contain these two parts.

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.

Developments in Scanning Hall Probe Microscopy

Science.gov (United States)

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.

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

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

Adapted Traditions: The Case of Traditional Palestinian Women Healers in Israel

Directory of Open Access Journals (Sweden)

Ariela Popper-Giveon

2009-02-01

Full Text Available This article examines transformations in the roles and treatment practices of traditional Palestinian women healers in Israel. Comparing narratives of women healers residing in Jewish-Arab mixed cities in central Israel with those of their counterparts in the Bedouin community of the Negev reveals that traditional healing has not disappeared as a result of modernization but rather has transformed. Urban women healers are abandoning treatment of physical problems in favor of addressing life hardships; they distance themselves from problems whose cause and treatment are considered natural and prefer those perceived as derived from supernatural causes and treated through supernatural, magical and religious means. Despite these transformations, traditional Palestinian women healers appear as agents of preservation and conservatism, a role that imbues them with a central position in their community. Hence, their place is currently secured and expected to remain so as processes of modernization and acculturation increase in intensity. URN: urn:nbn:de:0114-fqs0902119

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.

Useful Pedagogical Applications of the Classical Hall Effect

Science.gov (United States)

Houari, Ahmed

2007-01-01

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

To love or hate thy neighbor : The role of authoritarianism and traditionalism in explaining the link between fundamentalism and racial prejudice

NARCIS (Netherlands)

Brandt, M.J.; Reyna, C.

2014-01-01

Fundamentalism is consistently related to racial prejudice (Hall, Matz, & Wood, 2010), yet the mechanisms for this relationship are unclear. We identify two core values of fundamentalism, authoritarianism and traditionalism, that independently contribute to the fundamentalism‐racial prejudice

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.

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.

Staffing and Technology Maximize Dorm Security.

Science.gov (United States)

George, Stephen C.

1996-01-01

Loyola University of Chicago uses uniformed guards and electronic monitoring to prevent unauthorized entry into its 11 residence halls. Access to all residence halls is regulated by bar-code readers. Student ID cards also have color-coded stickers corresponding to specific residence halls. (MLF)

NASA HERMeS Hall Thruster Electrical Configuration Characterization

Science.gov (United States)

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.

Inverse spin Hall effect by spin injection

Science.gov (United States)

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

2007-09-01

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

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.

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

Hall Conductivity in a Quasi-Two-Dimensional Disordered Electron System

Institute of Scientific and Technical Information of China (English)

YANG Yong-Hong; WANG Yong-Gang; LIU Mei

2002-01-01

By making use of the diagrammatic techniques in perturbation theory,we have investigated the Hall effect in a quasi-two-dimensional disordered electron system.In the weakly localized regime,the analytical expression for quantum correction to Hall conductivity has been obtained using the Kubo formalism and quasiclassical approximation.The relevant dimensional crossover behavior from three dimensions to two dimensions with decreasing the interlayer hopping energy is discussed.The quantum interference effect is shown to have a vanishing correction t,o the Hall coefficient.

Algorithm and exploratory study of the Hall MHD Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Gardiner, Thomas Anthony

2010-01-01

This report is concerned with the influence of the Hall term on the nonlinear evolution of the Rayleigh-Taylor (RT) instability. This begins with a review of the magnetohydrodynamic (MHD) equations including the Hall term and the wave modes which are present in the system on time scales short enough that the plasma can be approximated as being stationary. In this limit one obtains what are known as the electron MHD (EMHD) equations which support two characteristic wave modes known as the whistler and Hall drift modes. Each of these modes is considered in some detail in order to draw attention to their key features. This analysis also serves to provide a background for testing the numerical algorithms used in this work. The numerical methods are briefly described and the EMHD solver is then tested for the evolution of whistler and Hall drift modes. These methods are then applied to study the nonlinear evolution of the MHD RT instability with and without the Hall term for two different configurations. The influence of the Hall term on the mixing and bubble growth rate are analyzed.

G. Stanley Hall and The Journal of Genetic Psychology: A Note.

Science.gov (United States)

Hogan, John D

2016-01-01

The Journal of Genetic Psychology (originally called The Pedagogical Seminary) has a complicated history. Known primarily as a journal of development psychology, it was originally intended to be a journal of higher education. In addition, G. Stanley Hall created it, at least in part, to curry favor with Jonas Clark, the benefactor of Clark University. The journal had a cumbersome start, with irregular issues for most of its first decade. Hall was a hands-on editor, often contributing articles and reviews as well as the texts of many of his speeches. A substantial number of additional articles were written by Clark University faculty and fellows where Hall was president. After Hall.s death, the editor became Carl Murchison who eventually left Clark University with the journal and continued to publish it privately until his death. Through the years, the journal has been the source for many classic articles in developmental psychology.

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

Testing a Beverage and Fruit/Vegetable Education Intervention in a University Dining Hall.

Science.gov (United States)

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.

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

Development of a novel sports medicine rotation for emergency medicine residents

Directory of Open Access Journals (Sweden)

Waterbrook AL

2016-04-01

Full Text Available Anna L Waterbrook,1 T Gail Pritchard,2 Allison D Lane,1 Lisa R Stoneking,1 Bryna Koch,2 Robert McAtee,1 Kristi H Grall,1 Alice A Min,1 Jessica Prior,1 Isaac Farrell,1 Holly G McNulty,1 Uwe Stolz1 1Department of Emergency Medicine, 2Office of Medical Student Education, The University of Arizona, Tucson, AZ, USA Abstract: Musculoskeletal complaints are the most common reason for patients to visit a physician, yet competency in musculoskeletal medicine is invariably reported as a deficiency in medical education in the USA. Sports medicine clinical rotations improve both medical students' and residents' musculoskeletal knowledge. Despite the importance of this knowledge, a standardized sports medicine curriculum in emergency medicine (EM does not exist. Hence, we developed a novel sports medicine rotation for EM residents to improve their musculoskeletal educational experience and to improve their knowledge in musculoskeletal medicine by teaching the evaluation and management of many common musculoskeletal disorders and injuries that are encountered in the emergency department. The University of Arizona has two distinct EM residency programs, South Campus (SC and University Campus (UC. The UC curriculum includes a traditional 4-week orthopedic rotation, which consistently rated poorly on evaluations by residents. Therefore, with the initiation of a new EM residency at SC, we replaced the standard orthopedic rotation with a novel sports medicine rotation for EM interns. This rotation includes attendance at sports medicine clinics with primary care and orthopedic sports medicine physicians, involvement in sport event coverage, assigned reading materials, didactic experiences, and an on-call schedule to assist with reductions in the emergency department. We analyzed postrotation surveys completed by residents, postrotation evaluations of the residents completed by primary care sports medicine faculty and orthopedic chief residents, as well as the

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

"Hall mees" Linnateatris / Triin Sinissaar

Index Scriptorium Estoniae

Sinissaar, Triin

1999-01-01

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

Virtual Alternative to the Oral Examination for Emergency Medicine Residents

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McGrath, Jillian

2015-02-01

Full Text Available Introduction: The oral examination is a traditional method for assessing the developing physician’s medical knowledge, clinical reasoning and interpersonal skills. The typical oral examination is a face-to-face encounter in which examiners quiz examinees on how they would confront a patient case. The advantage of the oral exam is that the examiner can adapt questions to the examinee’s response. The disadvantage is the potential for examiner bias and intimidation. Computer-based virtual simulation technology has been widely used in the gaming industry. We wondered whether virtual simulation could serve as a practical format for delivery of an oral examination. For this project, we compared the attitudes and performance of emergency medicine (EM residents who took our traditional oral exam to those who took the exam using virtual simulation. Methods: EM residents (n=35 were randomized to a traditional oral examination format (n=17 or a simulated virtual examination format (n=18 conducted within an immersive learning environment, Second Life (SL. Proctors scored residents using the American Board of Emergency Medicine oral examination assessment instruments, which included execution of critical actions and ratings on eight competency categories (1-8 scale. Study participants were also surveyed about their oral examination experience. Results: We observed no differences between virtual and traditional groups on critical action scores or scores on eight competency categories. However, we noted moderate effect sizes favoring the Second Life group on the clinical competence score. Examinees from both groups thought that their assessment was realistic, fair, objective, and efficient. Examinees from the virtual group reported a preference for the virtual format and felt that the format was less intimidating. Conclusion: The virtual simulated oral examination was shown to be a feasible alternative to the traditional oral examination format for

A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

Science.gov (United States)

Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

2013-01-01

This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

Radiation conditions in the ring hall of the IHEP proton synchrotron

International Nuclear Information System (INIS)

Borodin, V.E.; Ermolenko, L.S.; Obryashchikova, L.P.

1975-01-01

The paper presents the results on studying the radiation conditions caused by induced radioactivity of the accelerator units in the ring hall. The data on the induced radioactivity level just on the ring vacuum chamber are reported. Radiation conditions in the most characteristic areas of the hall are considered. The changes in time of the dose rate at the internal target and at the entrance to the hall are shown

The Monty Hall Dilemma.

Science.gov (United States)

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)

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....

Low-Cost, High-Performance Hall Thruster Support System

Science.gov (United States)

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.

The Hall-induced stability of gravitating fluids

Science.gov (United States)

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.

Comparison of the multiple mini-interview with the traditional interview for U.S. emergency medicine residency applicants: a single-institution experience.

Science.gov (United States)

Soares, William E; Sohoni, Aparajita; Hern, Herbert G; Wills, Charlotte P; Alter, Harrison J; Simon, Barry C

2015-01-01

The multiple mini-interview (MMI) is a validated interview technique used primarily to evaluate medical school applicants. No study has compared MMIs with traditional interviews (TIs) in the evaluation of U.S. emergency medicine residency (EMR) applicants. During the 2011-2012 interview season, a four-station MMI was incorporated into the interview process for EMR applicants at Alameda Health System-Highland Hospital (AHS). A postinterview anonymous questionnaire was offered to all applicants after they submitted their rank lists but prior to release of National Residency Matching Program results. Respondents rated their perceptions of the MMI and TI on a five-point Likert scale. McNemar chi-square test was used to explore differences in respondents' perceptions of interview styles. One hundred ten interviewees completed the survey (73%). Overall, applicants found the TI more enjoyable than the MMI process (98 [89%] compared with 48 [44%], McNemar chi-square=28.66, P<.01) and preferred the TI process to the MMI (66 [60%] compared with 9 [10%], McNemar chi-square=40.81, P<.01). Sixteen applicants (14%) indicated that the use of the MMI would negatively affect their ranking of the program. In contrast to prior studies, U.S. EMR applicants to AHS preferred the TI to the MMI. Further investigation into the use of the MMI for selecting U.S. EMR applicants is warranted.

3D Quantum Hall Effect of Fermi Arc in Topological Semimetals

Science.gov (United States)

Wang, C. M.; Sun, Hai-Peng; Lu, Hai-Zhou; Xie, X. C.

2017-09-01

The quantum Hall effect is usually observed in 2D systems. We show that the Fermi arcs can give rise to a distinctive 3D quantum Hall effect in topological semimetals. Because of the topological constraint, the Fermi arc at a single surface has an open Fermi surface, which cannot host the quantum Hall effect. Via a "wormhole" tunneling assisted by the Weyl nodes, the Fermi arcs at opposite surfaces can form a complete Fermi loop and support the quantum Hall effect. The edge states of the Fermi arcs show a unique 3D distribution, giving an example of (d -2 )-dimensional boundary states. This is distinctly different from the surface-state quantum Hall effect from a single surface of topological insulator. As the Fermi energy sweeps through the Weyl nodes, the sheet Hall conductivity evolves from the 1 /B dependence to quantized plateaus at the Weyl nodes. This behavior can be realized by tuning gate voltages in a slab of topological semimetal, such as the TaAs family, Cd3 As2 , or Na3Bi . This work will be instructive not only for searching transport signatures of the Fermi arcs but also for exploring novel electron gases in other topological phases of matter.

Mary E. Hall: Dawn of the Professional School Librarian

Science.gov (United States)

Alto, Teresa

2012-01-01

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

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...

Experimental and theoretical studies of cylindrical Hall thrusters

International Nuclear Information System (INIS)

Smirnov, Artem; Raitses, Yegeny; Fisch, Nathaniel J.

2007-01-01

The Hall thruster is a mature electric propulsion device that holds considerable promise in terms of the propellant saving potential. The annular design of the conventional Hall thruster, however, does not naturally scale to low power. The efficiency tends to be lower and the lifetime issues are more aggravated. Cylindrical geometry Hall thrusters have lower surface-to-volume ratio than conventional thrusters and, thus, seem to be more promising for scaling down. The cylindrical Hall thruster (CHT) is fundamentally different from the conventional design in the way the electrons are confined and the ion space charge is neutralized. The performances of both the large (9-cm channel diameter, 600-1000 W) and miniaturized (2.6-cm channel diameter, 50-300 W) CHTs are comparable with those of the state-of-the-art conventional (annular) design Hall thrusters of similar sizes. A comprehensive experimental and theoretical study of the CHT physics has been conducted, addressing the questions of electron cross-field transport, propellant ionization, plasma-wall interaction, and formation of the electron distribution function. Probe measurements in the harsh plasma environment of the microthruster were performed. Several interesting effects, such as the unusually high ionization efficiency and enhanced electron transport, were observed. Kinetic simulations suggest the existence of the strong fluctuation-enhanced electron diffusion and predict the non-Maxwellian shape of the electron distribution function. Through the acquired understanding of the new physics, ways for further optimization of this means for low-power space propulsion are suggested. Substantial flexibility in the magnetic field configuration of the CHT is the key tool in achieving the high-efficiency operation

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

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

Judy Estes Hall (1940-2015).

Science.gov (United States)

Sammons, Morgan T; Boucher, Andrew

2016-01-01

Presents an obituary for Judy Estes Hall, who passed away on November 24, 2015. Hall served as the Executive Officer of the National Register of Health Service Psychologists until her retirement in 2013. She is a recognized expert in the development of education and training standards for the profession of psychology, she also made significant contributions in the field of international psychology, where she was a renowned expert in cross-national credentialing and an advocate for commonality in licensing standards. She was the coauthor of one edited volume and author of more than 60 journal articles, book chapters, and professional publications. A passionate advocate for the advancement of women in psychology, a devoted mother and grandmother, a connoisseur of wine and international traveler extraordinaire, she touched the personal and professional lives of many. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Effect of hall currents on thermal instability of dusty couple stress fluid

Directory of Open Access Journals (Sweden)

Aggarwal Amrish Kumar

2016-09-01

Full Text Available In this paper, effect of Hall currents on the thermal instability of couple-stress fluid permeated with dust particles has been considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For the case of stationary convection, dust particles and Hall currents are found to have destabilizing effect while couple stresses have stabilizing effect on the system. Magnetic field induced by Hall currents has stabilizing/destabilizing effect under certain conditions. It is found that due to the presence of Hall currents (hence magnetic field, oscillatory modes are produced which were non-existent in their absence.

Hall Measurements on Carbon Nanotube Paper Modified With Electroless Deposited Platinum

Directory of Open Access Journals (Sweden)

Iwuoha Emmanuel

2009-01-01

Full Text Available Abstract Carbon nanotube paper, sometimes referred to as bucky paper, is a random arrangement of carbon nanotubes meshed into a single robust structure, which can be manipulated with relative ease. Multi-walled carbon nanotubes were used to make the nanotube paper, and were subsequently modified with platinum using an electroless deposition method based on substrate enhanced electroless deposition. This involves the use of a sacrificial metal substrate that undergoes electro-dissolution while the platinum metal deposits out of solution onto the nanotube paper via a galvanic displacement reaction. The samples were characterized using SEM/EDS, and Hall-effect measurements. The SEM/EDS analysis clearly revealed deposits of platinum (Pt distributed over the nanotube paper surface, and the qualitative elemental analysis revealed co-deposition of other elements from the metal substrates used. When stainless steel was used as sacrificial metal a large degree of Pt contamination with various other metals was observed. Whereas when pure sacrificial metals were used bimetallic Pt clusters resulted. The co-deposition of a bimetallic system upon carbon nanotubes was a function of the metal type and the time of exposure. Hall-effect measurements revealed some interesting fluctuations in sheet carrier density and the dominant carrier switched from N- to P-type when Pt was deposited onto the nanotube paper. Perspectives on the use of the nanotube paper as a replacement to traditional carbon cloth in water electrolysis systems are also discussed.

Electron Cross-field Transport in a Miniaturized Cylindrical Hall Thruster

International Nuclear Information System (INIS)

Smirnov Artem; Raitses Yevgeny; Fisch Nathaniel J

2005-01-01

Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. The present paper gives a review of the experimental and numerical investigations of electron crossfield transport in the 2.6 cm miniaturized cylindrical Hall thruster (100 W power level). We show that, in order to explain the discharge current observed for the typical operating conditions, the electron anomalous collision frequency ν b has to be on the order of the Bohm value, ν B ∼ ω c /16. The contribution of electron-wall collisions to cross-field transport is found to be insignificant. The optimal regimes of thruster operation at low background pressure (below 10 -5 Torr) in the vacuum tank appear to be different from those at higher pressure (∼ 10 -4 Torr)

Academicians and Neurologic Physical Therapy Residents Partner to Expand Clinical Reflection Using the SOLO Taxonomy: A Novel Approach.

Science.gov (United States)

Pinto Zipp, Genevieve; Maher, Catherine; Donnelly, Erin; Fritz, Brian; Snowdon, Lauren

2016-01-01

Creating curriculums that develop physical therapy (PT) students into evidenced-based, critically reflective, entry-level practitioners is one of the primary goals for PT programs. Academic faculty partnering with neurologic residency programs to design learning environments that capitalize upon the strengths of both can create insightful educational experiences for students during their didactic training. These partnerships support the development of critical thinking skills and provide mentorship for residents transitioning from their role as a clinician to that of an educator. Using the SOLO (structure of observed learning outcomes) taxonomy as a framework for developing learning experiences, Seton Hall University neurologic academic faculty and program directors from the Kessler Institute for Rehabilitation Residency in Neurologic Physical Therapy have built a partnership that seeks to develop critical reflection skills in both the neurologic resident and entry-level PT students. While integration of residents into entry-level PT curriculum may not be novel, we believe that utilizing the SOLO model within this partnership is unique. This paper describes the partnership and learning experiences rooted in the SOLO taxonomy theoretical framework and discusses perceived benefits of this learning experience across professional health science programs.

Magnetotransport properties of 8-Pmmn borophene: effects of Hall field and strain.

Science.gov (United States)

Islam, S K Firoz

2018-07-11

The polymorph of 8-Pmmn borophene is an anisotropic Dirac material with tilted Dirac cones at two valleys. The tilting of the Dirac cones at two valleys are in opposite directions, which manifests itself via the valley dependent Landau levels in presence of an in-plane electric field (Hall field). The valley dependent Landau levels cause valley polarized magnetotransport properties in presence of the Hall field, which is in contrast to the monolayer graphene with isotropic non-tilted Dirac cones. The longitudinal conductivity and Hall conductivity are evaluated by using linear response theory in low temperature regime. An analytical approximate form of the longitudinal conductivity is also obtained. It is observed that the tilting of the Dirac cones amplifies the frequency of the longitudinal conductivity oscillation (Shubnikov-de Haas). On the other hand, the Hall conductivity exhibits graphene-like plateaus except the appearance of valley dependent steps which are purely attributed to the Hall field induced lifting of the valley degeneracy in the Landau levels. Finally we look into the different cases when the Hall field is applied to the strained borophene and find that valley dependency is fully dominated by strain rather than Hall field. Another noticeable point is that if the real magnetic field is replaced by the strain induced pseudo magnetic field then the electric field looses its ability to cause valley polarized transport.

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

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.

SUSTAINABLE WASTE MANAGEMENT OF TRADITIONAL CRAFT INDUSTRY IN LOPATI TOURISM VILLAGE, YOGYAKARTA

Directory of Open Access Journals (Sweden)

VITASURYA Vincentia Reni

2016-12-01

Full Text Available Ecotourism has been growing in Yogyakarta that can be seen through the development of rural tourism. The development of rural tourism has positive impact to improve local community’s welfare nevertheless, it has also negative impact onto environmental carrying capacity. Lopati tourism village is located in Bantul, Yogyakarta, relying on traditional craft industry as tourism attraction. Traditional crafts are livelihood of local residents, so that environmental management efforts become part of their daily lives. This research aims to review the roles of community to reduce environmental impacts through analyzing the waste management of traditional craft industry. It used case study method to examine the uniqueness of Lopati village. Data collecting used participatory action research techniques in order to gather information from residents. Community participation acted to anticipate negative impact on development of rural tourism.  Waste management in Lopati committed by local residents not to cause adverse environmental impacts. The result show that waste management based on community participation supports the development of rural tourism.

Is integrated nursing home care cheaper than traditional care? A cost comparison.

Science.gov (United States)

Paulus, Aggie T G; van Raak, Arno J A; Maarse, Hans J A M

2008-12-01

It is generally assumed that integrated care has a cost-saving potential in comparison with traditional care. However, there is little evidence on this potential with respect to integrated nursing home care. DESIGN/METHODS/SETTINGS/PARTICIPANTS: Between 1999 and 2003, formal and informal caregivers of different nursing homes in the Netherlands recorded activities performed for residents with somatic or psycho-social problems. In total, 23,380 lists were analysed to determine the average costs of formal and informal care per activity, per type of resident and per nursing home care type. For formal care activities, the total personnel costs per minute (in Euro) were calculated. For informal care costs, two shadow prices were used. Compared to traditional care, integrated care had lower informal direct care costs per resident and per activity and lower average costs per direct activity (for a set of activities performed by formal caregivers). The total average costs per resident per day and the costs of formal direct care per resident, however, were higher as were the costs of delivering a set of indirect activities to residents with somatic problems. The general assumption that integrated care has a cost-saving potential (per resident or per individual activity) was only partially supported by our research. Our study also raised issues which should be investigated in future research on integrated nursing home care.

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

Evaluation of Pressure Changes in HANARO Reactor Hall after a Reactor Shutdown

International Nuclear Information System (INIS)

Han, Geeyang; Han, Jaesam; Ahn, Gukhoon; Jung, Hoansung

2013-01-01

The major objective of this work is intended to evaluate the characteristics of the thermal behavior regarding how the decay heat will be affected by the reactor hall pressure change and the increase of pool water temperature induced in the primary coolant after a reactor shutdown. The particular reactor pool water temperature at the surface where it is evaporated owing to the decay heat resulting in the local heat transfer rate is related to the pressure change response in the reactor hall associated with the primary cooling system because of the reduction of the heat exchanger to remove the heat. The increase in the pool water temperature is proportional to the heat transfer rate in the reactor pool. Consequently, any limit on the reactor pool water temperature imposes a corresponding limit on the reactor hall pressure. At HANARO, the decay heat after a reactor shutdown is mainly removed by the natural circulation cooling in the reactor pool. This paper is written for the safety feature of the pressure change related leakage rate from the reactor hall. The calculation results show that the increase of pressure in the reactor hall will not cause any serious problems to the safety limits although the reactor hall pressure is slightly increased. Therefore, it was concluded that the pool water temperature increase is not so rapid as to cause the pressure to vary significantly in the reactor hall. Furthermore, the mathematical model developed in this work can be a useful analytical tool for scoping and parametric studies in the area of thermal transient analysis, with its proper representation of the interaction between the temperature and pressure in the reactor hall

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.

A highly sensitive CMOS digital Hall sensor for low magnetic field applications.

Science.gov (United States)

Xu, Yue; Pan, Hong-Bin; He, Shu-Zhuan; Li, Li

2012-01-01

Integrated CMOS Hall sensors have been widely used to measure magnetic fields. However, they are difficult to work with in a low magnetic field environment due to their low sensitivity and large offset. This paper describes a highly sensitive digital Hall sensor fabricated in 0.18 μm high voltage CMOS technology for low field applications. The sensor consists of a switched cross-shaped Hall plate and a novel signal conditioner. It effectively eliminates offset and low frequency 1/f noise by applying a dynamic quadrature offset cancellation technique. The measured results show the optimal Hall plate achieves a high current related sensitivity of about 310 V/AT. The whole sensor has a remarkable ability to measure a minimum ± 2 mT magnetic field and output a digital Hall signal in a wide temperature range from -40 °C to 120 °C.

Edge states and integer quantum Hall effect in topological insulator thin films.

Science.gov (United States)

Zhang, Song-Bo; Lu, Hai-Zhou; Shen, Shun-Qing

2015-08-25

The integer quantum Hall effect is a topological state of quantum matter in two dimensions, and has recently been observed in three-dimensional topological insulator thin films. Here we study the Landau levels and edge states of surface Dirac fermions in topological insulators under strong magnetic field. We examine the formation of the quantum plateaux of the Hall conductance and find two different patterns, in one pattern the filling number covers all integers while only odd integers in the other. We focus on the quantum plateau closest to zero energy and demonstrate the breakdown of the quantum spin Hall effect resulting from structure inversion asymmetry. The phase diagrams of the quantum Hall states are presented as functions of magnetic field, gate voltage and chemical potential. This work establishes an intuitive picture of the edge states to understand the integer quantum Hall effect for Dirac electrons in topological insulator thin films.

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.

Comparison of teaching about breast cancer via mobile or traditional learning methods in gynecology residents.

Science.gov (United States)

Alipour, Sadaf; Moini, Ashraf; Jafari-Adli, Shahrzad; Gharaie, Nooshin; Mansouri, Khorshid

2012-01-01

Mobile learning enables users to interact with educational resources while in variable locations. Medical students in residency positions need to assimilate considerable knowledge besides their practical training and we therefore aimed to evaluate the impact of using short message service via cell phone as a learning tool in residents of Obstetrics and Gynecology in our hospital. We sent short messages including data about breast cancer to the cell phones of 25 residents of gynecology and obstetrics and asked them to study a well-designed booklet containing another set of information about the disease in the same period. The rate of learning derived from the two methods was compared by pre- and post-tests and self-satisfaction assessed by a relevant questionnaire at the end of the program. The mobile learning method had a significantly better effect on learning and created more interest in the subject. Learning via receiving SMS can be an effective and appealing method of knowledge acquisition in higher levels of education.

Hall effect on magnetohydrodynamic instabilities at an elliptic magnetic stagnation line

Science.gov (United States)

Spies, Günther O.; Faghihi, Mustafa

1987-06-01

To answer the question whether the Hall effect removes the unphysical feature of ideal magnetohydrodynamics of predicting small wavelength kink instabilities at any elliptic magnetic stagnation line, a normal mode analysis is performed of the motion of an incompressible Hall fluid about cylindrical Z-pinch equilibria with circular cross sections. The eigenvalue loci in the complex frequency plane are derived for the equilibrium with constant current density. Every particular mode becomes stable as the Hall parameter exceeds a critical value. This value, however, depends on the mode such that it increases to infinity as the ideal growth rate decreases to zero, implying that there always remains an infinite number of slowly growing instabilities. Correspondingly, the stability criterion for equilibria with arbitrary current distributions is independent of the Hall parameter.

Hall effect on magnetohydrodynamic instabilities at an elliptic magnetic stagnation line

International Nuclear Information System (INIS)

Spies, G.O.; Faghihi, M.

1987-01-01

To answer the question whether the Hall effect removes the unphysical feature of ideal magnetohydrodynamics of predicting small wavelength kink instabilities at any elliptic magnetic stagnation line, a normal mode analysis is performed of the motion of an incompressible Hall fluid about cylindrical Z-pinch equilibria with circular cross sections. The eigenvalue loci in the complex frequency plane are derived for the equilibrium with constant current density. Every particular mode becomes stable as the Hall parameter exceeds a critical value. This value, however, depends on the mode such that it increases to infinity as the ideal growth rate decreases to zero, implying that there always remains an infinite number of slowly growing instabilities. Correspondingly, the stability criterion for equilibria with arbitrary current distributions is independent of the Hall parameter

Influence of energy bands on the Hall effect in degenerate semiconductors

International Nuclear Information System (INIS)

Wu, Chhi-Chong; Tsai, Jensan

1989-01-01

The influence of energy bands on the Hall effect and transverse magnetoresistance has been investigated according to the scattering processes of carriers in degenerate semiconductors such as InSb. Results show that the Hall angle, Hall coefficient, and transverse magnetoresistance depend on the dc magnetic field for both parabolic and nonparabolic band structures of semiconductors and also depend on the scattering processes of carriers in semiconductors due to the energy-dependent relaxation time. From their numerical analysis for the Hall effect, it is shown that the conduction electrons in degenerate semiconductors play a major role for the carrier transport phenomenon. By comparing with experimental data of the transverse magnetoresistance, it shows that the nonparabolic band model is better in agreement with the experimental work than the parabolic band model of semiconductors

1000 Hours of Testing Completed on 10-kW Hall Thruster

Science.gov (United States)

Mason, Lee S.

2001-01-01

Between the months of April and August 2000, a 10-kW Hall effect thruster, designated T- 220, was subjected to a 1000-hr life test evaluation. Hall effect thrusters are propulsion devices that electrostatically accelerate xenon ions to produce thrust. Hall effect propulsion has been in development for many years, and low-power devices (1.35 kW) have been used in space for satellite orbit maintenance. The T-220, shown in the photo, produces sufficient thrust to enable efficient orbital transfers, saving hundreds of kilograms in propellant over conventional chemical propulsion systems. This test is the longest operation ever achieved on a high-power Hall thruster (greater than 4.5 kW) and is a key milestone leading to the use of this technology for future NASA, commercial, and military missions.

Particle-in-cell simulations of Hall plasma thrusters

Science.gov (United States)

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.

Observation of the fractional quantum Hall effect in graphene.

Science.gov (United States)

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.

Quantifying Spin Hall Angles from Spin Pumping : Experiments and Theory

NARCIS (Netherlands)

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

Familial Pallister-Hall in adulthood.

Science.gov (United States)

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.

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

Main Parameters Characterization of Bulk CMOS Cross-Like Hall Structures

Directory of Open Access Journals (Sweden)

Maria-Alexandra Paun

2016-01-01

Full Text Available A detailed analysis of the cross-like Hall cells integrated in regular bulk CMOS technological process is performed. To this purpose their main parameters have been evaluated. A three-dimensional physical model was employed in order to evaluate the structures. On this occasion, numerical information on the input resistance, Hall voltage, conduction current, and electrical potential distribution has been obtained. Experimental results for the absolute sensitivity, offset, and offset temperature drift have also been provided. A quadratic behavior of the residual offset with the temperature was obtained and the temperature points leading to the minimum offset for the three Hall cells were identified.

An Innovative Clinical Skills “Boot Camp” for Dental Medicine Residents

Directory of Open Access Journals (Sweden)

Jenny Castillo

2017-05-01

Full Text Available During a 1-year hospital-based residency, dental residents are required to rotate through many departments including surgery, medicine, and emergency medicine. It became apparent that there was a gap between clinical skills knowledge taught in dental school curriculum and skills required for hospital-based patient care. In response, a simulation-based intensive clinical skill “boot camp” was created. The boot camp provided an intensive, interactive 3-day session for the dental residents. During the 3 days, residents were introduced to medical knowledge and skills that were necessary for their inpatient hospital rotations but were lacking in traditional dental school curriculum. Effectiveness of the boot camp was assessed in terms of knowledge base and comfort through presession and postsession surveys. According to resident feedback, this intensive introduction for the dental residents improved their readiness for their inpatient hospital-based residency.

Spin Hall effect for anyons

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

Pediatric Integrative Medicine in Residency Program: Relationship between Lifestyle Behaviors and Burnout and Wellbeing Measures in First-Year Residents.

Science.gov (United States)

McClafferty, Hilary; Brooks, Audrey J; Chen, Mei-Kuang; Brenner, Michelle; Brown, Melanie; Esparham, Anna; Gerstbacher, Dana; Golianu, Brenda; Mark, John; Weydert, Joy; Yeh, Ann Ming; Maizes, Victoria

2018-04-23

It is widely recognized that burnout is prevalent in medical culture and begins early in training. Studies show pediatricians and pediatric trainees experience burnout rates comparable to other specialties. Newly developed Accreditation Council for Graduate Medical Education (ACGME) core competencies in professionalism and personal development recognize the unacceptably high resident burnout rates and present an important opportunity for programs to improve residents experience throughout training. These competencies encourage healthy lifestyle practices and cultivation of self-awareness, self-regulation, empathy, mindfulness, and compassion—a paradigm shift from traditional medical training underpinned by a culture of unrealistic endurance and self-sacrifice. To date, few successful and sustainable programs in resident burnout prevention and wellness promotion have been described. The University of Arizona Center for Integrative Medicine Pediatric Integrative Medicine in Residency (PIMR) curriculum, developed in 2011, was designed in part to help pediatric programs meet new resident wellbeing requirements. The purpose of this paper is to detail levels of lifestyle behaviors, burnout, and wellbeing for the PIMR program’s first-year residents ( N = 203), and to examine the impact of lifestyle behaviors on burnout and wellbeing. The potential of the PIMR to provide interventions addressing gaps in lifestyle behaviors with recognized association to burnout is discussed.

Pediatric Integrative Medicine in Residency Program: Relationship between Lifestyle Behaviors and Burnout and Wellbeing Measures in First-Year Residents

Directory of Open Access Journals (Sweden)

Hilary McClafferty

2018-04-01

Full Text Available It is widely recognized that burnout is prevalent in medical culture and begins early in training. Studies show pediatricians and pediatric trainees experience burnout rates comparable to other specialties. Newly developed Accreditation Council for Graduate Medical Education (ACGME core competencies in professionalism and personal development recognize the unacceptably high resident burnout rates and present an important opportunity for programs to improve residents experience throughout training. These competencies encourage healthy lifestyle practices and cultivation of self-awareness, self-regulation, empathy, mindfulness, and compassion—a paradigm shift from traditional medical training underpinned by a culture of unrealistic endurance and self-sacrifice. To date, few successful and sustainable programs in resident burnout prevention and wellness promotion have been described. The University of Arizona Center for Integrative Medicine Pediatric Integrative Medicine in Residency (PIMR curriculum, developed in 2011, was designed in part to help pediatric programs meet new resident wellbeing requirements. The purpose of this paper is to detail levels of lifestyle behaviors, burnout, and wellbeing for the PIMR program’s first-year residents (N = 203, and to examine the impact of lifestyle behaviors on burnout and wellbeing. The potential of the PIMR to provide interventions addressing gaps in lifestyle behaviors with recognized association to burnout is discussed.

Effects of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers

KAUST Repository

Guo, Zaibing

2012-09-27

In this paper, we report the results of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers with perpendicular magnetic anisotropy. The surface scattering effect has been extracted from the total anomalous Hall effect. By scaling surface scattering contribution with ρAHs∼ργss, the exponent γ has been found to decrease with the increase of surface scattering resistivity, which could account for the thickness-dependent anomalous Hall effect. Interface diffusion induced by rapid thermal annealing modifies not only the magnetization and longitudinal resistivity but also the anomalous Hall effect; a large exponent γ ∼ 5.7 has been attributed to interface scattering-dominated anomalous Hall effect.

On-tip sub-micrometer Hall probes for magnetic microscopy prepared by AFM lithography

International Nuclear Information System (INIS)

Gregusova, D.; Martaus, J.; Fedor, J.; Kudela, R.; Kostic, I.; Cambel, V.

2009-01-01

We developed a technology of sub-micrometer Hall probes for future application in scanning hall probe microscopy (SHPM) and magnetic force microscopy (MFM). First, the Hall probes of ∼9-μm dimensions are prepared on the top of high-aspect-ratio GaAs pyramids with an InGaP/AlGaAs/GaAs active layer using wet-chemical etching and non-planar lithography. Then we show that the active area of planar Hall probes can be downsized to sub-micrometer dimensions by local anodic oxidation technique using an atomic force microscope. Such planar probes are tested and their noise and magnetic field sensitivity are evaluated. Finally, the two technologies are combined to fabricate sub-micrometer Hall probes on the top of high-aspect ratio mesa for future SHPM and MFM techniques.

Room acoustic enhancement in a small hall with very low natural reverberation time

DEFF Research Database (Denmark)

Gade, Anders Christian

1996-01-01

natural combinations of room acoustic properties. Consequently, the natural reverberation time in a newly opened 350 seat multipurpose hall in Denmark was designed as low as 0.7 sec. Two different reverberation enhancement systems were considered and tested in the hall. The objective and subjective...... testing results are reported and compared with previous results obtained in another small hall supplied with a similar enhancement system. The results concerning 'realism' are also compared with acoustic properties found in 'natural' halls of different sizes and reverberation times.......In small multipurpose halls to be equipped with electronic reverberation enhancement systems, selecting a very low natural reverberation time is advantageous for several reasons. It will 1) reduce the risk of feedback, 2) increase the possible range of room acoustic variation and 3) allow for more...

The Hall coefficient: a tool for characterizing graphene field effect transistors

International Nuclear Information System (INIS)

Wehrfritz, Peter; Seyller, Thomas

2014-01-01

Graphene field effect transistors are considered as a candidate for future high-frequency applications. For their realization, the optimal combination of substrate, graphene preparation, and insulator deposition and composition is required. This optimization must be based on an in-depth characterization of the obtained graphene insulator metal (GIM) stack. Hall effect measurements are frequently employed to study such systems, thereby focussing primarily on the charge carrier mobility. In this work we show how an analysis of the sheet Hall coefficient can reveal further important properties of the GIM stack, like, e.g., the interface trap density and the spacial charge inhomogeneity. To that end, we provide an extensive description of the GIM diode, which leads to an accurate calculation of the sheet Hall coefficient dependent on temperature and gate voltage. The gate dependent inverse sheet Hall coefficient is discussed in detail before we introduce the concept of an equivalent temperature, which is a measure of the spacial charge inhomogeneity. In order to test the concept, we apply it to evaluate already measured Hall data taken from the literature. This evaluation allows us to determine the Drude mobility, even at the charge neutrality point, which is inaccessible with a simple one band Hall mobility analysis, and to shed light on the spacial charge inhomogeneity. The formalism is easily adaptable and provides experimentalists a powerful tool for the characterization of their graphene field effect devices. (paper)

Overview of NASA Iodine Hall Thruster Propulsion System Development

Science.gov (United States)

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

2016-01-01

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

Electrical control of the anomalous valley Hall effect in antiferrovalley bilayers

Science.gov (United States)

Tong, Wen-Yi; Duan, Chun-Gang

2017-08-01

In analogy to all-electric spintronics, all-electric valleytronics, i.e., valley manipulation via electric means, becomes an exciting new frontier as it may bring revolutions in the field of data storage with ultra-high speed and ultra-low power consumption. The existence of the anomalous valley Hall effect in ferrovalley materials demonstrates the possibility of electrical detection for valley polarization. However, in previously proposed valley-polarized monolayers, the anomalous valley Hall effect is controlled by external magnetic fields. Here, through elaborate structural design, we propose the antiferrovally bilayer as an ideal candidate for realizing all-electric valleytronic devices. Using the minimal k.p model, we show that the energy degeneracy between valley indexes in such system can be lifted by electric approaches. Subsequently, the anomalous valley Hall effect strongly depends on the electric field as well. Taking the bilayer VSe2 as an example, all-electric tuning and detecting of anomalous valley Hall effect is confirmed by density-functional theory calculations, indicating that the valley information in such antiferrovalley bilayer can be reversed by an electric field perpendicular to the plane of the system and easily probed through the sign of the Hall voltage.

Sub-grid-scale effects on short-wave instability in magnetized hall-MHD plasma

International Nuclear Information System (INIS)

Miura, H.; Nakajima, N.

2010-11-01

Aiming to clarify effects of short-wave modes on nonlinear evolution/saturation of the ballooning instability in the Large Helical Device, fully three-dimensional simulations of the single-fluid MHD and the Hall MHD equations are carried out. A moderate parallel heat conductivity plays an important role both in the two kinds of simulations. In the single-fluid MHD simulations, the parallel heat conduction effectively suppresses short-wave ballooning modes but it turns out that the suppression is insufficient in comparison to an experimental result. In the Hall MHD simulations, the parallel heat conduction triggers a rapid growth of the parallel flow and enhance nonlinear couplings. A comparison between single-fluid and the Hall MHD simulations reveals that the Hall MHD model does not necessarily improve the saturated pressure profile, and that we may need a further extension of the model. We also find by a comparison between two Hall MHD simulations with different numerical resolutions that sub-grid-scales of the Hall term should be modeled to mimic an inverse energy transfer in the wave number space. (author)

A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C., E-mail: acbruno@puc-rio.br

2017-03-15

We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10{sup −7} Am{sup 2}. We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am{sup 2}/kg (i.e 0.4%) at saturation and below 0.5 Am{sup 2}/kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

International Nuclear Information System (INIS)

Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C.

2017-01-01

We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10 −7 Am 2 . We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am 2 /kg (i.e 0.4%) at saturation and below 0.5 Am 2 /kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

Hallé SHINE on Manchester: Evaluation Report and Executive Summary

Science.gov (United States)

Menzies, Victoria; Kasim, Adetayo; Kokotsaki, Dimitra; Hewitt, Catherine; Akhter, Nasima; Collyer, Clare; Younger, Kirsty; Wiggins, Andy; Torgerson, Carole

2016-01-01

The "Hallé SHINE on Manchester" (HSoM) programme is a Saturday school educational programme designed to increase the reading and maths attainment, as well as engagement with school, of underachieving and disadvantaged pupils at Key Stage 2. Developed in collaboration between the SHINE Trust and Hallé Orchestra, the intervention provides…

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.

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

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

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

Multi-region relaxed Hall magnetohydrodynamics with flow

Energy Technology Data Exchange (ETDEWEB)

Lingam, Manasvi, E-mail: mlingam@princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Abdelhamid, Hamdi M., E-mail: hamdi@ppl.k.u-tokyo.ac.jp [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Physics Department, Faculty of Science, Mansoura University, Mansoura 35516 (Egypt); Hudson, Stuart R., E-mail: shudson@pppl.gov [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, New Jersey 08543 (United States)

2016-08-15

The recent formulations of multi-region relaxed magnetohydrodynamics (MRxMHD) have generalized the famous Woltjer-Taylor states by incorporating a collection of “ideal barriers” that prevent global relaxation and flow. In this paper, we generalize MRxMHD with flow to include Hall effects, and thereby obtain the partially relaxed counterparts of the famous double Beltrami states as a special subset. The physical and mathematical consequences arising from the introduction of the Hall term are also presented. We demonstrate that our results (in the ideal MHD limit) constitute an important subset of ideal MHD equilibria, and we compare our approach against other variational principles proposed for deriving the partially relaxed states.

Use of simulation-based education to improve resident learning and patient care in the medical intensive care unit: a randomized trial.

Science.gov (United States)

Schroedl, Clara J; Corbridge, Thomas C; Cohen, Elaine R; Fakhran, Sherene S; Schimmel, Daniel; McGaghie, William C; Wayne, Diane B

2012-04-01

The purpose of this study is to determine the effect of simulation-based education on the knowledge and skills of internal medicine residents in the medical intensive care unit (MICU). From January 2009 to January 2010, 60 first-year residents at a tertiary care teaching hospital were randomized by month of rotation to an intervention group (simulator-trained, n = 26) and a control group (traditionally trained, n = 34). Simulator-trained residents completed 4 hours of simulation-based education before their medical intensive care unit (MICU) rotation. Topics included circulatory shock, respiratory failure, and mechanical ventilation. After their rotation, residents completed a standardized bedside skills assessment using a 14-item checklist regarding respiratory mechanics, ventilator settings, and circulatory parameters. Performance of simulator-trained and traditionally trained residents was compared using a 2-tailed independent-samples t test. Simulator-trained residents scored significantly higher on the bedside skills assessment compared with traditionally trained residents (82.5% ± 10.6% vs 74.8% ± 14.1%, P = .027). Simulator-trained residents were highly satisfied with the simulation curriculum. Simulation-based education significantly improved resident knowledge and skill in the MICU. Knowledge acquired in the simulated environment was transferred to improved bedside skills caring for MICU patients. Simulation-based education is a valuable adjunct to standard clinical training for residents in the MICU. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

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)

Assembly Hall de la Universidad de Illinois, USA

Directory of Open Access Journals (Sweden)

Harrison & Abramovitz, Arquitectos

1970-05-01

Full Text Available The Assembly Hall of Illinois University has been constructed with an original reinforced and prestressed concrete structure. It has a seating capacity for 15,565 spectators, in addition to space for press, radio and TV. staff, for the performers, and for invalid spectators who use wheeled chairs. The seating capacity can be further extended by providing 1,500 portable chairs. This hall can be adapted to many uses, and has suitable equipment and installations for assemblies, theatrical and musical performances, ice skating, sports competitions and circus shows. The provision of this magnificent hall has made it possible to organise at the University of Illinois many activities that were not practicable before.Con una original estructura realizada a base de hormigón armado y pretensado ha sido construido el «Assembly Hall», de la Universidad de Illinois, con capacidad para 15.565 espectadores sentados —además de los espacios reservados a los representantes de la prensa, radio y T.V., artistas y espectadores inválidos que acudan en carritos de ruedas—. Puede ser ampliada colocando unas 1.500 sillas portátiles. El edificio está destinado a múltiples usos y dispone de los equipos e instalaciones adecuadas para todo tipo de celebraciones: asambleas, representaciones teatrales y musicales; espectáculos de: circo, patinaje sobre hielo, competiciones deportivas, etc., y ha permitido organizar, en el seno de la Universidad de Illinois, una serie de actividades que antes resultaban imposibles.

Hall Thruster Thermal Modeling and Test Data Correlation

Science.gov (United States)

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.

2D massless QED Hall half-integer conductivity and graphene

International Nuclear Information System (INIS)

Martínez, A Pérez; Querts, E Rodriguez; Rojas, H Pérez; Gaitan, R; Rodriguez-Romo, S

2011-01-01

Starting from the photon self-energy tensor in a magnetized medium, the 3D complete antisymmetric form of the conductivity tensor is found in the static limit of a fermion system C-non-invariant under fermion–antifermion exchange. The massless relativistic 2D fermion limit in QED is derived by using the compactification along the dimension parallel to the magnetic field. In the static limit and at zero temperature, the main features of the quantum Hall effect (QHE) are obtained: the half-integer QHE and the minimum value proportional to e 2 /h for the Hall conductivity. For typical values of graphene the plateaus of the Hall conductivity are also reproduced. (paper)

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

Crossover between spin swapping and Hall effect in disordered systems

KAUST Repository

Saidaoui, Hamed Ben Mohamed

2015-07-16

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

Diaphragm Effect of Steel Space Roof Systems in Hall Structures

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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

Crossover between spin swapping and Hall effect in disordered systems

KAUST Repository

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.

Residents' Appreciation of Cultural Heritage in Tourist Centres: A Microsimulation Modelling Approach to Amsterdam

NARCIS (Netherlands)

van Leeuwen, E.S.; Kourtit, K.; Nijkamp, P.

2013-01-01

This paper addresses the question of the value attached by residents to the wealth of cultural heritage in their city. Particular attention is given to the impact of various types of information (ranging from traditional to advanced ICT sources) on residents' valuation of cultural heritage. Based on

Minimizing Barriers in Learning for On-Call Radiology Residents-End-to-End Web-Based Resident Feedback System.

Science.gov (United States)

Choi, Hailey H; Clark, Jennifer; Jay, Ann K; Filice, Ross W

2018-02-01

Feedback is an essential part of medical training, where trainees are provided with information regarding their performance and further directions for improvement. In diagnostic radiology, feedback entails a detailed review of the differences between the residents' preliminary interpretation and the attendings' final interpretation of imaging studies. While the on-call experience of independently interpreting complex cases is important to resident education, the more traditional synchronous "read-out" or joint review is impossible due to multiple constraints. Without an efficient method to compare reports, grade discrepancies, convey salient teaching points, and view images, valuable lessons in image interpretation and report construction are lost. We developed a streamlined web-based system, including report comparison and image viewing, to minimize barriers in asynchronous communication between attending radiologists and on-call residents. Our system provides real-time, end-to-end delivery of case-specific and user-specific feedback in a streamlined, easy-to-view format. We assessed quality improvement subjectively through surveys and objectively through participation metrics. Our web-based feedback system improved user satisfaction for both attending and resident radiologists, and increased attending participation, particularly with regards to cases where substantive discrepancies were identified.

Voltage transients in thin-film InSb Hall sensor

Directory of Open Access Journals (Sweden)

Alexey Bardin

Full Text Available The work is reached to study temperature transients in thin-film Hall sensors. We experimentally study InSb thin-film Hall sensor. We find transients of voltage with amplitude about 10 μV on the sensor ports after current switching. We demonstrate by direct measurements that the transients is caused by thermo-e.m.f., and both non-stationarity and heterogeneity of temperature in the film. We find significant asymmetry of temperature field for different direction of the current, which is probably related to Peltier effect. The result can be useful for wide range of scientist who works with switching of high density currents in any thin semiconductor films. 2000 MSC: 41A05, 41A10, 65D05, 65D17, Keywords: Thin-films, Semiconductors, Hall sensor, InSb, thermo-e.m.f.

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

Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers

KAUST Repository

Manchon, Aurelien

2017-01-01

We investigate the emergence of spin Hall magnetoresistance in a magnetic bilayer composed of a normal metal adjacent to an antiferromagnet. Based on a recently derived drift diffusion equation, we show that the resistance of the bilayer depends on the relative angle between the direction transverse to the current flow and the Néel order parameter. While this effect presents striking similarities with the spin Hall magnetoresistance recently reported in ferromagnetic bilayers, its physical origin is attributed to the anisotropic spin relaxation of itinerant spins in the antiferromagnet.

Spin Hall effect by surface roughness

KAUST Repository

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.

On electrostatic acceleration of plasmas with the Hall effect using electrode shaping

International Nuclear Information System (INIS)

Wang, Zhehui; Barnes, Cris W.

2001-01-01

Resistive magnetohydrodynamics (MHD) is used to model the electromagnetic acceleration of plasmas in coaxial channels. When the Hall effect is considered, the inclusion of resistivity is necessary to obtain physically meaningful solutions. In resistive MHD with the Hall effect, if and only if the electric current and the plasma flow are orthogonal (J·U=0), then there is a conserved quantity, in the form of U 2 /2+w+eΦ/M, along the flow, where U is the flow velocity, Φ is the electric potential, w is the enthalpy, and M is the ion mass. New solutions suggest that in coaxial geometry the Hall effect along the axial plasma flow can be balanced by proper shaping of conducting electrodes, with acceleration then caused by an electrostatic potential drop along the streamlines of the flow. The Hall effect separation of ion and electron flow then just cancels the electrostatic charge separation. Assuming particle ionization increases with energy density in the system, the resulting particle flow rates (J p ) scales with accelerator bias (V bias ) as J p ∝V bias 2 , exceeding the Child--Langmuir limit. The magnitude of the Hall effect (as determined by the Morozov Hall parameter, Ξ, which is defined as the ratio of electric current to particle current) is related to the energy needed for the creation of each ion--electron pair

THE PREVALENCE OF ELEVATED LEVELS OF C-REACTIVE PROTEIN AND ITS ASSOCIATION WITH TRADITIONAL RISK FACTORS AND MORBIDITY AMONG RESIDENTS OF THE RUSSIAN FEDERATION (ACCORDING TO THE ESSE-RF STUDY

Directory of Open Access Journals (Sweden)

S. E. Evstifeeva

2014-01-01

Full Text Available Aim. To study the association of high-sensitivity C-reactive protein (hsCRP level with socio-demographic, behavioral and traditional risk factors in different regions of the Russian Federation (RF.Material and methods. Data of the multicenter epidemiological study of cardiovascular disease in different regions of the Russian Federation (ESSE-RF were used. Representative sample of the unorganized male and female population aged 25-64 from 6 regions of the Russian Federation was drown. 3407 men and 6354 women (n=9761 were included into the study. Standard questionnaire was applied in all subjects. Gender, age, level of education, place of residence and region of residence, traditional risk factors and diseases were analyzed. HsCRP level (level ≥3.0 mg/l was defined as elevated one was evaluated to detect of indolent inflammation.Results. HsCRP levels in women was significantly higher compared to males (p<0.005. The average prevalence of elevated hsCRP in the regions was 24.2%, for men - 21.4%, and for women - 25.7% (p<0.005. Significant age-related dynamics of hsCRP (p<0.0001 was found. The average level of hsCRP was significantly lower (p<0.0001 in a cohort of persons with higher education against these with lower level of education. Level of hsCRP as well as prevalence of elevated hsCRP level were higher in villagers than this in the urban population (p<0.05. Prevalence of elevated hsCRP in patients with traditional risk factors after adjustment for sex, age, and region of residence showed that the elevated hsCRP was mostly associated with metabolic factors and diseases that were characterized by systemic inflammation.Conclusion. Elevated level of hsCRP (≥3.0 mg/l was significantly associated with female gender, with an older, less educated, and smoking population of Russians. After the multivariate adjustment there remained significant associations (p<0.0001 of elevated hsCRP level with obesity, including abdominal obesity, hyperglycemia

THE PREVALENCE OF ELEVATED LEVELS OF C-REACTIVE PROTEIN AND ITS ASSOCIATION WITH TRADITIONAL RISK FACTORS AND MORBIDITY AMONG RESIDENTS OF THE RUSSIAN FEDERATION (ACCORDING TO THE ESSE-RF STUDY

Directory of Open Access Journals (Sweden)

S. E. Evstifeeva

2015-09-01

Full Text Available Aim. To study the association of high-sensitivity C-reactive protein (hsCRP level with socio-demographic, behavioral and traditional risk factors in different regions of the Russian Federation (RF.Material and methods. Data of the multicenter epidemiological study of cardiovascular disease in different regions of the Russian Federation (ESSE-RF were used. Representative sample of the unorganized male and female population aged 25-64 from 6 regions of the Russian Federation was drown. 3407 men and 6354 women (n=9761 were included into the study. Standard questionnaire was applied in all subjects. Gender, age, level of education, place of residence and region of residence, traditional risk factors and diseases were analyzed. HsCRP level (level ≥3.0 mg/l was defined as elevated one was evaluated to detect of indolent inflammation.Results. HsCRP levels in women was significantly higher compared to males (p<0.005. The average prevalence of elevated hsCRP in the regions was 24.2%, for men - 21.4%, and for women - 25.7% (p<0.005. Significant age-related dynamics of hsCRP (p<0.0001 was found. The average level of hsCRP was significantly lower (p<0.0001 in a cohort of persons with higher education against these with lower level of education. Level of hsCRP as well as prevalence of elevated hsCRP level were higher in villagers than this in the urban population (p<0.05. Prevalence of elevated hsCRP in patients with traditional risk factors after adjustment for sex, age, and region of residence showed that the elevated hsCRP was mostly associated with metabolic factors and diseases that were characterized by systemic inflammation.Conclusion. Elevated level of hsCRP (≥3.0 mg/l was significantly associated with female gender, with an older, less educated, and smoking population of Russians. After the multivariate adjustment there remained significant associations (p<0.0001 of elevated hsCRP level with obesity, including abdominal obesity, hyperglycemia

The flipped classroom: a modality for mixed asynchronous and synchronous learning in a residency program.

Science.gov (United States)

Young, Timothy P; Bailey, Caleb J; Guptill, Mindi; Thorp, Andrea W; Thomas, Tamara L

2014-11-01

A "flipped classroom" educational model exchanges the traditional format of a classroom lecture and homework problem set. We piloted two flipped classroom sessions in our emergency medicine (EM) residency didactic schedule. We aimed to learn about resident and faculty impressions of the sessions, in order to develop them as a regular component of our residency curriculum. We evaluated residents' impression of the asynchronous video component and synchronous classroom component using four Likert items. We used open-ended questions to inquire about resident and faculty impressions of the advantages and disadvantages of the format. For the Likert items evaluating the video lectures, 33/35 residents (94%, 95% CI 80%-99%) responded that the video lecture added to their knowledge about the topic, and 33/35 residents felt that watching the video was a valuable use of their time. For items evaluating the flipped classroom format, 36/38 residents (95%, 95% CI 82%-99%) preferred the format to a traditional lecture on the topic, and 38/38 residents (100%, 95% CI 89%-100%) felt that the small group session was effective in helping them learn about the topic. Most residents preferred to see the format monthly in our curriculum and chose an ideal group size of 5.5 (first session) and 7 (second session). Residents cited the interactivity of the sessions and access to experts as advantages of the format. Faculty felt the ability to assess residents' understanding of concepts and provide feedback were advantages. Our flipped classroom model was positively received by EM residents. Residents preferred a small group size and favored frequent use of the format in our curriculum. The flipped classroom represents one modality that programs may use to incorporate a mixture of asynchronous and interactive synchronous learning and provide additional opportunities to evaluate residents.

Hall mobility of free charge carriers in highly compensated p-Germanium

International Nuclear Information System (INIS)

Gavrilyuk, V.Yi.; Kirnas, Yi.G.; Balakyin, V.D.

2000-01-01

Hall mobility of free charge carriers in initial detectors Ge (Ga) is studied. It is established that an increase in the compensation factor results in the enlargement of Hall mobility in germanium highly compensated by introduction of Li ions during their drift in an electrical field

Quasi-one-dimensional Hall physics in the Harper–Hofstadter–Mott model

Science.gov (United States)

Kozarski, Filip; Hügel, Dario; Pollet, Lode

2018-04-01

We study the ground-state phase diagram of the strongly interacting Harper–Hofstadter–Mott model at quarter flux on a quasi-one-dimensional lattice consisting of a single magnetic flux quantum in y-direction. In addition to superfluid phases with various density patterns, the ground-state phase diagram features quasi-one-dimensional analogs of fractional quantum Hall phases at fillings ν = 1/2 and 3/2, where the latter is only found thanks to the hopping anisotropy and the quasi-one-dimensional geometry. At integer fillings—where in the full two-dimensional system the ground-state is expected to be gapless—we observe gapped non-degenerate ground-states: at ν = 1 it shows an odd ‘fermionic’ Hall conductance, while the Hall response at ν = 2 consists of the transverse transport of a single particle–hole pair, resulting in a net zero Hall conductance. The results are obtained by exact diagonalization and in the reciprocal mean-field approximation.

Paired quantum Hall states on noncommutative two-tori

Energy Technology Data Exchange (ETDEWEB)

Marotta, Vincenzo [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' and INFN, Sezione di Napoli, Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy); Naddeo, Adele, E-mail: naddeo@sa.infn.i [CNISM, Unita di Ricerca di Salerno and Dipartimento di Fisica ' E. R. Caianiello' , Universita degli Studi di Salerno, Via Salvador Allende, 84081 Baronissi (Italy)

2010-08-01

By exploiting the notion of Morita equivalence for field theories on noncommutative tori and choosing rational values of the noncommutativity parameter theta (in appropriate units), a one-to-one correspondence between an Abelian noncommutative field theory (NCFT) and a non-Abelian theory of twisted fields on ordinary space can be established. Starting from this general result, we focus on the conformal field theory (CFT) describing a quantum Hall fluid (QHF) at paired states fillings nu=m/(pm+2) Cristofano et al. (2000) , recently obtained by means of m-reduction procedure, and show that it is the Morita equivalent of a NCFT. In this way we extend the construction proposed in Marotta and Naddeo (2008) for the Jain series nu=m/(2pm+1) . The case m=2 is explicitly discussed and the role of noncommutativity in the physics of quantum Hall bilayers is emphasized. Our results represent a step forward the construction of a new effective low energy description of certain condensed matter phenomena and help to clarify the relationship between noncommutativity and quantum Hall fluids.

ADHM and the 4d quantum Hall effect

Science.gov (United States)

Barns-Graham, Alec; Dorey, Nick; Lohitsiri, Nakarin; Tong, David; Turner, Carl

2018-04-01

Yang-Mills instantons are solitonic particles in d = 4 + 1 dimensional gauge theories. We construct and analyse the quantum Hall states that arise when these particles are restricted to the lowest Landau level. We describe the ground state wavefunctions for both Abelian and non-Abelian quantum Hall states. Although our model is purely bosonic, we show that the excitations of this 4d quantum Hall state are governed by the Nekrasov partition function of a certain five dimensional supersymmetric gauge theory with Chern-Simons term. The partition function can also be interpreted as a variant of the Hilbert series of the instanton moduli space, counting holomorphic sections rather than holomorphic functions. It is known that the Hilbert series of the instanton moduli space can be rewritten using mirror symmetry of 3d gauge theories in terms of Coulomb branch variables. We generalise this approach to include the effect of a five dimensional Chern-Simons term. We demonstrate that the resulting Coulomb branch formula coincides with the corresponding Higgs branch Molien integral which, in turn, reproduces the standard formula for the Nekrasov partition function.

Mission and System Advantages of Iodine Hall Thrusters

Science.gov (United States)

Dankanich, John W.; Szabo, James; Pote, Bruce; Oleson, Steve; Kamhawi, Hani

2014-01-01

The exploration of alternative propellants for Hall thrusters continues to be of interest to the community. Investments have been made and continue for the maturation of iodine based Hall thrusters. Iodine testing has shown comparable performance to xenon. However, iodine has a higher storage density and resulting higher ?V capability for volume constrained systems. Iodine's vapor pressure is low enough to permit low-pressure storage, but high enough to minimize potential adverse spacecraft-thruster interactions. The low vapor pressure also means that iodine does not condense inside the thruster at ordinary operating temperatures. Iodine is safe, it stores at sub-atmospheric pressure, and can be stored unregulated for years on end; whether on the ground or on orbit. Iodine fills a niche for both low power (10kW) electric propulsion regimes. A range of missions have been evaluated for direct comparison of Iodine and Xenon options. The results show advantages of iodine Hall systems for both small and microsatellite application and for very large exploration class missions.

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

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)

Stuart Hall on Racism and the Importance of Diasporic Thinking

Science.gov (United States)

Rizvi, Fazal

2015-01-01

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

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)

ATLAS Assembly Hall Open Day

CERN Multimedia

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.

SPATIAL ANALYSIS OF RESIDENTS' FEAR AND FEELING OF ...

African Journals Online (AJOL)

Osondu

Abstract. This study examined spatial pattern of crime and residents' fear and feeling of insecurity in Ile-Ife,. Nigeria. To obtain the primary data, Ile-Ife was stratified into four residential zones namely traditional town centre, middle income, high income and post-crisis residential areas. Sample was selected using systematic ...

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

Sensitivity Enhancement of a Vertical-Type CMOS Hall Device for a Magnetic Sensor

Directory of Open Access Journals (Sweden)

Sein Oh

2018-01-01

Full Text Available This study presents a vertical-type CMOS Hall device with improved sensitivity to detect a 3D magnetic field in various types of sensors or communication devices. To improve sensitivity, trenches are implanted next to the current input terminal, so that the Hall current becomes maximum. The effect of the dimension and location of trenches on sensitivity is simulated in the COMSOL simulator. A vertical-type Hall device with a width of 16 μm and a height of 2 μm is optimized for maximum sensitivity. The simulation result shows that it has a 23% better result than a conventional vertical-type CMOS Hall device without a trench.

Photo-modulation of the spin Hall conductivity of mono-layer transition metal dichalcogenides

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Parijat; Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 (United States)

2016-05-23

We report on a possible optical tuning of the spin Hall conductivity in mono-layer transition metal dichalcogenides. Light beams of frequencies much higher than the energy scale of the system (the off-resonant condition) do not excite electrons but rearrange the band structure. The rearrangement is quantitatively established using the Floquet formalism. For such a system of mono-layer transition metal dichalcogenides, the spin Hall conductivity (calculated with the Kubo expression in presence of disorder) exhibits a drop at higher frequencies and lower intensities. Finally, we compare the spin Hall conductivity of the higher spin-orbit coupled WSe{sub 2} to MoS{sub 2}; the spin Hall conductivity of WSe{sub 2} was found to be larger.

Overview of Iodine Propellant Hall Thruster Development Activities at NASA Glenn Research Center

Science.gov (United States)

Kamhawi, Hani; Benavides, Gabriel; Haag, Thomas; Hickman, Tyler; Smith, Timothy; Williams, George; Myers, James; Polzin, Kurt; Dankanich, John; Byrne, Larry;

Hall viscosity of a chiral two-orbital superconductor at finite temperatures

Science.gov (United States)

Yazdani-Hamid, Meghdad; Shahzamanian, Mohammad Ali

2018-06-01

The Hall viscosity known as the anti-symmetric part of the viscosity fourth-rank tensor. Such dissipationless response which appears for systems with broken time reversal symmetry. We calculate this non-dissipative quantity for a chiral two-orbital superconductor placed in a viscoelastic magnetic field using the linear response theory and apply our calculations to the putative multiband chiral superconductor Sr2RuO4. The chirality origin of a multiband superconductor arises from the interorbital coupling of the superconducting state. This feature leads to the robustness of the Hall viscosity against temperature and impurity effects. We study the temperature effect on the Hall viscosity at the one-loop approximation.

AA under construction in its hall

CERN Multimedia

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 !

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

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.)

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)

TH-E-201-00: Teaching Radiology Residents: What, How, and Expectation

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant.

TH-E-201-01: Diagnostic Radiology Residents Physics Curriculum and Updates

Energy Technology Data Exchange (ETDEWEB)

Sensakovic, W. [Florida Hospital (United States)

2016-06-15

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant.

TH-E-201-00: Teaching Radiology Residents: What, How, and Expectation

International Nuclear Information System (INIS)

2016-01-01

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant

TH-E-201-01: Diagnostic Radiology Residents Physics Curriculum and Updates

International Nuclear Information System (INIS)

Sensakovic, W.

2016-01-01

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant

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

SUSTAINED LIVEABILITY: A FRAMEWORK BEYOND ENERGY CONSCIOUS BUILDING CONSERVATION OF MARKET HALLS

Directory of Open Access Journals (Sweden)

Neveen Hamza

2017-11-01

Full Text Available Market halls are commonly found in  contexts of cultural and heritage value. Positioned in urban centres and transport networks, these unique buildings were originally constructed in the 19th century to ensure better food distribution in growing European cities, then copied to other territories such as Egypt.  We argue that leaving market halls, with their large spanning structures and indoor open space, for dilapidation is a lost opportunity for sustaining community engagement, and educating the public on the original sustainability, neighbourhood regeneration and cultural thinking that underpinned these buildings. The proposed framework extends current sustainable ‘heritage conservation frameworks’ beyond concepts of adding renewable energy technologies, recycling and sustainable goods movement,  to ‘sustaining liveability and social inclusion’. We argue that market halls offer the opportunities to merge the daily activities of buying and selling food with creating local creative economies such as culinary art exhibitions, and culinary schools. The paper consists of two parts: the first discusses the historical urban context of market halls in Cairo; the second proposes a sustainable heritage conservation model for market halls.

AdS/QHE: towards a holographic description of quantum Hall experiments

International Nuclear Information System (INIS)

Bayntun, Allan; Burgess, C P; Lee, Sung-Sik; Dolan, Brian P

2011-01-01

Transitions among quantum Hall plateaux share a suite of remarkable experimental features, such as semicircle laws and duality relations, whose accuracy and robustness are difficult to explain directly in terms of the detailed dynamics of the microscopic electrons. They would naturally follow if the low-energy transport properties were governed by an emergent discrete duality group relating the different plateaux, but no explicit examples of interacting systems having such a group are known. Recent progress using the AdS/CFT correspondence has identified examples with similar duality groups, but without the dc ohmic conductivity characteristic of quantum Hall experiments. We use this to propose a simple holographic model for low-energy quantum Hall systems, with a nonzero dc conductivity that automatically exhibits all of the observed consequences of duality, including the existence of the plateaux and the semicircle transitions between them. The model can be regarded as a strongly coupled analogue of the old 'composite boson' picture of quantum Hall systems. Non-universal features of the model can be used to test whether it describes actual materials, and we comment on some of these in our proposed model. In particular, the model indicates the value 2/5 for low-temperature scaling exponents for transitions among quantum Hall plateaux, in agreement with the measured value 0.42±0.01.

Magnetic properties and Hall effect of single-crystalline YMn6Sn6

International Nuclear Information System (INIS)

Uhlirova, K.; Sechovsky, V.; Boer, F.R. de; Yoshii, S.; Yamamoto, T.; Hagiwara, M.; Lefevre, C.; Venturini, G.

2007-01-01

Magnetization behavior and Hall resistivity of YMn 6 Sn 6 , which crystallizes in the hexagonal HfFe 6 Ge 6 -type of structure, have been investigated on single crystals at various temperatures in the ordered magnetic state. The field dependence of the Hall resistivity shows anomalies, which are related to the field-induced spin reorientations occurring in YMn 6 Sn 6 . It is also found that the Hall resistivity cannot simply be described by the anomalous contribution proportional to the magnetization, but that an additional field-dependent contribution is present

Valley polarized quantum Hall effect and topological insulator phase transitions in silicene

KAUST Repository

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

The Flipped Classroom: A Modality for Mixed Asynchronous and Synchronous Learning in a Residency Program

Science.gov (United States)

Young, Timothy P.; Bailey, Caleb J.; Guptill, Mindi; Thorp, Andrea W.; Thomas, Tamara L.

2014-01-01

Introduction A “flipped classroom” educational model exchanges the traditional format of a classroom lecture and homework problem set. We piloted two flipped classroom sessions in our emergency medicine (EM) residency didactic schedule. We aimed to learn about resident and faculty impressions of the sessions, in order to develop them as a regular component of our residency curriculum. Methods We evaluated residents’ impression of the asynchronous video component and synchronous classroom component using four Likert items. We used open-ended questions to inquire about resident and faculty impressions of the advantages and disadvantages of the format. Results For the Likert items evaluating the video lectures, 33/35 residents (94%, 95% CI 80%–99%) responded that the video lecture added to their knowledge about the topic, and 33/35 residents felt that watching the video was a valuable use of their time. For items evaluating the flipped classroom format, 36/38 residents (95%, 95% CI 82%–99%) preferred the format to a traditional lecture on the topic, and 38/38 residents (100%, 95% CI 89%–100%) felt that the small group session was effective in helping them learn about the topic. Most residents preferred to see the format monthly in our curriculum and chose an ideal group size of 5.5 (first session) and 7 (second session). Residents cited the interactivity of the sessions and access to experts as advantages of the format. Faculty felt the ability to assess residents’ understanding of concepts and provide feedback were advantages. Conclusion Our flipped classroom model was positively received by EM residents. Residents preferred a small group size and favored frequent use of the format in our curriculum. The flipped classroom represents one modality that programs may use to incorporate a mixture of asynchronous and interactive synchronous learning and provide additional opportunities to evaluate residents. PMID:25493157

Education research: evaluating the use of podcasting for residents during EEG instruction: a pilot study.

Science.gov (United States)

Bensalem-Owen, Meriem; Chau, Destiny F; Sardam, Sean C; Fahy, Brenda G

2011-08-23

Educational methods for residents are shifting toward greater learner independence aided by technological advances. A Web-based program using a podcast was created for resident EEG instruction, replacing conventional didactics. The EEG curriculum also consisted of EEG interpretations under the tutelage of a neurophysiologist. This pilot study aimed to objectively evaluate the effectiveness of the podcast as a new teaching tool. A podcast for resident EEG instruction was implemented on the Web, replacing the traditional lecture. After Institutional Review Board approval, consent was obtained from the participating residents. Using 25-question evaluation tools, participants were assessed at baseline before any EEG instruction, and reassessed after podcasting and after 10 clinical EEG exposures. Each 25-item evaluation tool contained tracings used for clinical EEG interpretations. Scores after podcast training were also compared to scores after traditional didactic training from a previous study among anesthesiology trainees. Ten anesthesiology residents completed the study. The mean scores with standard deviations are 9.50 ± 2.92 at baseline, 13.40 ± 3.31 (p = 0.034) after the podcast, and 16.20 ± 1.87 (p = 0.019) after interpreting 10 EEGs. No differences were noted between the mean educational tool scores for those who underwent podcasting training compared to those who had undergone traditional didactic training. In this pilot study, podcast training was as effective as the prior conventional lecture in meeting the curricular goals of increasing EEG knowledge after 10 EEG interpretations as measured by assessment tools.

Axial Hall effect and universality of holographic Weyl semi-metals

Energy Technology Data Exchange (ETDEWEB)

Copetti, Christian; Fernández-Pendás, Jorge; Landsteiner, Karl [Instituto de Física Teórica UAM/CSIC,c/ Nicolás Cabrera 13-15, Cantoblanco, 28049 Madrid (Spain)

2017-02-28

The holographic Weyl semimetal is a model of a strongly coupled topological semi-metal. A topological quantum phase transition separates a topological phase with non-vanishing anomalous Hall conductivity from a trivial state. We investigate how this phase transition depends on the parameters of the scalar potential (mass and quartic self coupling) finding that the quantum phase transition persists for a large region in parameter space. We then compute the axial Hall conductivity. The algebraic structure of the axial anomaly predicts it to be 1/3 of the electric Hall conductivity. We find that this holds once a non-trivial renormalization effect on the external axial gauge fields is taken into account. Finally we show that the phase transition also occurs in a top-down model based on a consistent truncation of type IIB supergravity.

Understanding and Interrupting Hegemonic Projects in Education: Learning from Stuart Hall

Science.gov (United States)

Apple, Michael W.

2015-01-01

Stuart Hall had a significant impact on critical analyses of rightist mobilizations in education. This is very visible in my own work, for example, in such volumes as "Official Knowledge" (2014) and "Educating the 'Right' Way" (2006). After describing an important series of lectures that Stuart Hall gave at the Havens Center…

An edge index for the quantum spin-Hall effect

International Nuclear Information System (INIS)

Prodan, Emil

2009-01-01

Quantum spin-Hall systems are topological insulators displaying dissipationless spin currents flowing at the edges of the samples. In contradistinction to the quantum Hall systems where the charge conductance of the edge modes is quantized, the spin conductance is not and it remained an open problem to find the observable whose edge current is quantized. In this paper, we define a particular observable and the edge current corresponding to this observable. We show that this current is quantized and that the quantization is given by the index of a certain Fredholm operator. This provides a new topological invariant that is shown to take the generic values 0 and 2, in line with the Z 2 topological classification of time-reversal invariant systems. The result gives an effective tool for the investigation of the edge structure in quantum spin-Hall systems. Based on a reasonable assumption, we also show that the edge conducting channels are not destroyed by a random edge. (fast track communication)

Resistivity and Hall voltage in gold thin films deposited on mica at room temperature

Energy Technology Data Exchange (ETDEWEB)

Bahamondes, Sebastián; Donoso, Sebastián; Ibañez-Landeta, Antonio; Flores, Marcos [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Blanco Encalada 2008, Santiago (Chile); Henriquez, Ricardo, E-mail: ricardo.henriquez@usm.cl [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaiso 2390123 (Chile)

2015-03-30

Highlights: • We determined the 4 K thickness dependence of resistivity for a family of gold thin films. • We determined the thickness dependence of resistivity during the growth process. • Both behaviors are well represented by the Mayadas–Shatzkes theory. • We determined Hall tangent and Hall resistance at 4 K and up to 4.5 T. • Hall mobility is always higher than the drift mobility. - Abstract: We report the thickness dependence of the resistivity measured at 4 K of gold films grown onto mica at room temperature (RT), for thickness ranging from 8 to 100 nm. This dependence was compared to the one obtained for a sample during its growth process at RT. Both behaviors are well represented by the Mayadas–Shatzkes theory. Using this model, we found comparable contributions of electron surface and electron grain boundary scattering to the resistivity at 4 K. Hall effect measurements were performed using a variable transverse magnetic field up to 4.5 T. Hall tangent and Hall resistance exhibit a linear dependence on the magnetic field. For this magnetic field range, the Hall mobility is always larger than the drift mobility. This result is explained through the presence of the above-mentioned scattering mechanisms acting on the galvanomagnetic coefficients. In addition, we report the temperature dependence of the resistivity between 4 and 70 K.

The Value of a Resident Aesthetic Clinic: A 7-Year Institutional Review and Survey of the Chief Resident Experience.

Science.gov (United States)

Weissler, Jason M; Carney, Martin J; Yan, Chen; Percec, Ivona

2017-10-16

With the evolving plastic surgery training paradigm, there is an increasing emphasis on aesthetic surgery education during residency. In an effort to improve aesthetic education and to encourage preparation for independent practice, our institution has supported a resident-run aesthetic clinic for over two decades. To provide insight into the educational benefits of a resident-run cosmetic clinic through longitudinal resident follow up and institutional experiential review. A retrospective review was conducted to identify all clinic-based aesthetic operations performed between 2009 and 2016. To capture residents' perspectives on the cosmetic resident clinic, questionnaires were distributed to the cohort. Primary outcome measures included: volume and types of cases performed, impact of clinic experience on training, confidence level performing cosmetic procedures, and satisfaction with chief clinic. Unpaired t tests were calculated to compare case volume/type with level of confidence and degree of preparedness to perform cosmetic procedures independently. Overall, 264 operations performed by 18 graduated chief residents were reviewed. Surveys were distributed to 28 chief residents (71.4% completion rate). Performing twenty or more clinic-based procedures was associated with higher levels of preparedness to perform cosmetic procedures independently (P = 0.037). Residents reported the highest confidence when performing cosmetic breast procedures when compared to face/neck (P = 0.005), body/trunk procedures (P = 0.39), and noninvasive facial procedures (P = 0.85). The continued growth of aesthetic surgery highlights the need for comprehensive training and preparation for the new generation of plastic surgeons. Performing cosmetic procedures in clinic is a valuable adjunct to the traditional educational curriculum and increases preparedness and confidence for independent practice. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission

Giant photonic Hall effect in magnetophotonic crystals.

Science.gov (United States)

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.

The Influence Of Switching-Off The Big Lamps On The Humidity Operation Hall

International Nuclear Information System (INIS)

Wiranto, Slamet; Sriawan

2001-01-01

When there is no activity in the Operation Hall, the big lamps in this are switched off. Due to the water trap of ventilation system is not in good function, the humidity of the Operation Hall increases. In any point of time the humidity rise over the permitted limit value. To avoid this problem it is needed to investigate the characteristic by measuring the humidity of the Operation Hall at various condition and situation. From the characteristic, it can be determined that for normal condition, the Operation Hall big lamps should be switched off, and 2 days before start-up reactor, the all operation building lamps should be switched on for about 5 days as the operation building humidity back to normal value

Spin Hall effect in a 2DEG in the presence of magnetic couplings

International Nuclear Information System (INIS)

Gorini, C; Schwab, P; Dzierzawa, M; Raimondi, R; Milletari, M

2009-01-01

It is now well established that the peculiar linear-in-momentum dependence of the Rashba (and of the Dresselhaus) spin-orbit coupling leads to the vanishing of the spin Hall conductivity in the bulk of a two-dimensional electron gas (2DEG). In this paper we discuss how generic magnetic couplings change this behaviour providing then a potential handle on the spin Hall effect. In particular we examine the influence of magnetic impurities and an in-plane magnetic field. We find that in both cases there is a finite spin Hall effect and we provide explicit expressions for the spin Hall conductivity. The results can be obtained by means of the quasiclassical Green function approach, that we have recently extended to spin-orbit coupled electron systems.

Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra

International Nuclear Information System (INIS)

Duran, I.; Bolshakova, I.; Holyaka, R.; Viererbl, L.; Lahodova, Z.; Sentkerestiova, J.; Bem, P.

2010-01-01

We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10 16 cm -2 was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

Matsu Cultural Heritage and Its Conservation in Bohai Rim - Case Study on the Hall of Fujian in Yantai

Science.gov (United States)

Yao, S.

2015-08-01

Since the Yuan Dynasty, the belief of Matsu had started to spread from the birthplace to the northern coastal areas in China. Matsu worship developed to the pinnacle with the official promotion on account of the government's dependence on grain transported by sea since the mid-Qing Dynasty. A large amount of Matsu temples emerged in coastal cities of Bohai Rim where it still keeps a large number of them until now. It has much relationship between the spread of Matsu culture and the flow of Fujian population. It was one of the main building way that the Matsu temples attached to the local hall of Fujian in Bohai Rim. The Hall of Fujian in Yantai, Which was built with materials taken from Fujian, in the feature of traditional architectural style from QuanZhou, is very different from the local building style of Yantai. This case indicates that maritime culture of the south area had spread and developed in the north areas under the promotion of the population flow and the economic transaction. The essay introduces briefly about the development of Matsu culture in Bohai Rim and takes the case study of the Hall of Fujian in Yantai analyzing its causes and features, and the value as Matsu heritage. Then the paper will discuss the conservation of Matsu culture mere include the tangible and the intangible culture heritage around the origin area, the heritages of the spread area also have the same importance significance. With the evolution of the society, it calls urgent attention and protection of Matsu culture in Bohai Rim.

Electrocardiographic interpretation skills of cardiology residents: are they competent?

Science.gov (United States)

Sibbald, Matthew; Davies, Edward G; Dorian, Paul; Yu, Eric H C

2014-12-01

Achieving competency at electrocardiogram (ECG) interpretation among cardiology subspecialty residents has traditionally focused on interpreting a target number of ECGs during training. However, there is little evidence to support this approach. Further, there are no data documenting the competency of ECG interpretation skills among cardiology residents, who become de facto the gold standard in their practice communities. We tested 29 Cardiology residents from all 3 years in a large training program using a set of 20 ECGs collected from a community cardiology practice over a 1-month period. Residents interpreted half of the ECGs using a standard analytic framework, and half using their own approach. Residents were scored on the number of correct and incorrect diagnoses listed. Overall diagnostic accuracy was 58%. Of 6 potentially life-threatening diagnoses, residents missed 36% (123 of 348) including hyperkalemia (81%), long QT (52%), complete heart block (35%), and ventricular tachycardia (19%). Residents provided additional inappropriate diagnoses on 238 ECGs (41%). Diagnostic accuracy was similar between ECGs interpreted using an analytic framework vs ECGs interpreted without an analytic framework (59% vs 58%; F(1,1333) = 0.26; P = 0.61). Cardiology resident proficiency at ECG interpretation is suboptimal. Despite the use of an analytic framework, there remain significant deficiencies in ECG interpretation among Cardiology residents. A more systematic method of addressing these important learning gaps is urgently needed. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Integrated Stirling Convertor and Hall Thruster Test Conducted

Science.gov (United States)

Mason, Lee S.

2002-01-01

An important aspect of implementing Stirling Radioisotope Generators on future NASA missions is the integration of the generator and controller with potential spacecraft loads. Some recent studies have indicated that the combination of Stirling Radioisotope Generators and electric propulsion devices offer significant trip time and payload fraction benefits for deep space missions. A test was devised to begin to understand the interactions between Stirling generators and electric thrusters. An electrically heated RG- 350 (350-W output) Stirling convertor, designed and built by Stirling Technology Company of Kennewick, Washington, under a NASA Small Business Innovation Research agreement, was coupled to a 300-W SPT-50 Hall-effect thruster built for NASA by the Moscow Aviation Institute (RIAME). The RG-350 and the SPT-50 shown, were installed in adjacent vacuum chamber ports at NASA Glenn Research Center's Electric Propulsion Laboratory, Vacuum Facility 8. The Stirling electrical controller interfaced directly with the Hall thruster power-processing unit, both of which were located outside of the vacuum chamber. The power-processing unit accepted the 48 Vdc output from the Stirling controller and distributed the power to all the loads of the SPT-50, including the magnets, keeper, heater, and discharge. On February 28, 2001, the Glenn test team successfully operated the Hall-effect thruster with the Stirling convertor. This is the world's first known test of a dynamic power source with electric propulsion. The RG-350 successfully managed the transition from the purely resistive load bank within the Stirling controller to the highly capacitive power-processing unit load. At the time of the demonstration, the Stirling convertor was operating at a hot temperature of 530 C and a cold temperature of -6 C. The linear alternator was producing approximately 250 W at 109 Vac, while the power-processing unit was drawing 175 W at 48 Vdc. The majority of power was delivered to the

Parity effect of bipolar quantum Hall edge transport around graphene antidots.

Science.gov (United States)

Matsuo, Sadashige; Nakaharai, Shu; Komatsu, Katsuyoshi; Tsukagoshi, Kazuhito; Moriyama, Takahiro; Ono, Teruo; Kobayashi, Kensuke

2015-06-30

Parity effect, which means that even-odd property of an integer physical parameter results in an essential difference, ubiquitously appears and enables us to grasp its physical essence as the microscopic mechanism is less significant in coarse graining. Here we report a new parity effect of quantum Hall edge transport in graphene antidot devices with pn junctions (PNJs). We found and experimentally verified that the bipolar quantum Hall edge transport is drastically affected by the parity of the number of PNJs. This parity effect is universal in bipolar quantum Hall edge transport of not only graphene but also massless Dirac electron systems. These results offer a promising way to design electron interferometers in graphene.

Mode transition of a Hall thruster discharge plasma

International Nuclear Information System (INIS)

Hara, Kentaro; Sekerak, Michael J.; Boyd, Iain D.; Gallimore, Alec D.

2014-01-01

A Hall thruster is a cross-field plasma device used for spacecraft propulsion. An important unresolved issue in the development of Hall thrusters concerns the effect of discharge oscillations in the range of 10–30 kHz on their performance. The use of a high speed Langmuir probe system and ultra-fast imaging of the discharge plasma of a Hall thruster suggests that the discharge oscillation mode, often called the breathing mode, is strongly correlated to an axial global ionization mode. Stabilization of the global oscillation mode is achieved as the magnetic field is increased and azimuthally rotating spokes are observed. A hybrid-direct kinetic simulation that takes into account the transport of electronically excited atoms is used to model the discharge plasma of a Hall thruster. The predicted mode transition agrees with experiments in terms of the mean discharge current, the amplitude of discharge current oscillation, and the breathing mode frequency. It is observed that the stabilization of the global oscillation mode is associated with reduced electron transport that suppresses the ionization process inside the channel. As the Joule heating balances the other loss terms including the effects of wall loss and inelastic collisions, the ionization oscillation is damped, and the discharge oscillation stabilizes. A wide range of the stable operation is supported by the formation of a space charge saturated sheath that stabilizes the electron axial drift and balances the Joule heating as the magnetic field increases. Finally, it is indicated from the numerical results that there is a strong correlation between the emitted light intensity and the discharge current.

Disorder effect on chiral edge modes and anomalous Hall conductance in Weyl semimetals

International Nuclear Information System (INIS)

Takane, Yositake

2016-01-01

Typical Weyl semimetals host chiral surface states and hence show an anomalous Hall response. Although a Weyl semimetal phase is known to be robust against weak disorder, the effect of disorder on chiral states has not been fully clarified so far. We study the behavior of such chiral states in the presence of disorder and its consequences on an anomalous Hall response, focusing on a thin slab of Weyl semimetal with chiral surface states along its edge. It is shown that weak disorder does not disrupt chiral edge states but crucially affects them owing to the renormalization of a mass parameter: the number of chiral edge states changes depending on the strength of disorder. It is also shown that the Hall conductance is quantized when the Fermi level is located near Weyl nodes within a finite-size gap. This quantization of the Hall conductance collapses once the strength of disorder exceeds a critical value, suggesting that it serves as a probe to distinguish a Weyl semimetal phase from a diffusive anomalous Hall metal phase. (author)

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

Parametric studies of the Hall Thruster at Soreq

International Nuclear Information System (INIS)

Ashkenazy, J.; Rattses, Y.; Appelbaum, G.

1997-01-01

An electric propulsion program was initiated at Soreq a few years ago, aiming at the research and development of advanced Hall thrusters for various space applications. The Hall thruster accelerates a plasma jet by an axial electric field and an applied radial magnetic field in an annular ceramic channel. A relatively large current density (> 0.1 A/cm 2 ) can be obtained, since the acceleration mechanism is not limited by space charge effects. Such a device can be used as a small rocket engine onboard spacecraft with the advantage of a large jet velocity compared with conventional rocket engines (10,000-30,000 m/s vs. 2,000-4,800 m/s). An experimental Hall thruster was constructed at Soreq and operated under a broad range of operating conditions and under various configurational variations. Electrical, magnetic and plasma diagnostics, as well as accurate thrust and gas flow rate measurements, have been used to investigate the dependence of thruster behavior on the applied voltage, gas flow rate, magnetic field, channel geometry and wall material. Representative results highlighting the major findings of the studies conducted so far are presented

Dynamical quantum Hall effect in the parameter space.

Science.gov (United States)

Gritsev, V; Polkovnikov, A

2012-04-24

Geometric phases in quantum mechanics play an extraordinary role in broadening our understanding of fundamental significance of geometry in nature. One of the best known examples is the Berry phase [M.V. Berry (1984), Proc. Royal. Soc. London A, 392:45], which naturally emerges in quantum adiabatic evolution. So far the applicability and measurements of the Berry phase were mostly limited to systems of weakly interacting quasi-particles, where interference experiments are feasible. Here we show how one can go beyond this limitation and observe the Berry curvature, and hence the Berry phase, in generic systems as a nonadiabatic response of physical observables to the rate of change of an external parameter. These results can be interpreted as a dynamical quantum Hall effect in a parameter space. The conventional quantum Hall effect is a particular example of the general relation if one views the electric field as a rate of change of the vector potential. We illustrate our findings by analyzing the response of interacting spin chains to a rotating magnetic field. We observe the quantization of this response, which we term the rotational quantum Hall effect.

Extraordinary Hall effect in Co implanted GaAs hybrid magnetic semiconductors

International Nuclear Information System (INIS)

Honda, S.; Tateishi, K.; Nawate, M.; Sakamoto, I.

2004-01-01

Hybrid Co/GaAs ferromagnetic semiconductors have been prepared by implantation method. In these samples, sheet resistance shows weak temperature dependence, and the extraordinary Hall effect with positive coefficient is observed. In small Co content samples, Hall resistance increases with decreasing temperature and maximum value of 3.6x10 -2 Ω is obtained at 150 K

Exploring 4D quantum Hall physics with a 2D topological charge pump.

Science.gov (United States)

Lohse, Michael; Schweizer, Christian; Price, Hannah M; Zilberberg, Oded; Bloch, Immanuel

2018-01-03

The discovery of topological states of matter has greatly improved our understanding of phase transitions in physical systems. Instead of being described by local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example is the two-dimensional (2D) integer quantum Hall effect: it is characterized by the first Chern number, which manifests in the quantized Hall response that is induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional (4D) systems leads to the appearance of an additional quantized Hall response, but one that is nonlinear and described by a 4D topological invariant-the second Chern number. Here we report the observation of a bulk response with intrinsic 4D topology and demonstrate its quantization by measuring the associated second Chern number. By implementing a 2D topological charge pump using ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small cloud of atoms as a local probe, we fully characterize the nonlinear response of the system via in situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probing higher-dimensional quantum Hall systems, in which additional strongly correlated topological phases, exotic collective excitations and boundary phenomena such as isolated Weyl fermions are predicted.

Exploring 4D quantum Hall physics with a 2D topological charge pump

Science.gov (United States)

Lohse, Michael; Schweizer, Christian; Price, Hannah M.; Zilberberg, Oded; Bloch, Immanuel

2018-01-01

The discovery of topological states of matter has greatly improved our understanding of phase transitions in physical systems. Instead of being described by local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example is the two-dimensional (2D) integer quantum Hall effect: it is characterized by the first Chern number, which manifests in the quantized Hall response that is induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional (4D) systems leads to the appearance of an additional quantized Hall response, but one that is nonlinear and described by a 4D topological invariant—the second Chern number. Here we report the observation of a bulk response with intrinsic 4D topology and demonstrate its quantization by measuring the associated second Chern number. By implementing a 2D topological charge pump using ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small cloud of atoms as a local probe, we fully characterize the nonlinear response of the system via in situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probing higher-dimensional quantum Hall systems, in which additional strongly correlated topological phases, exotic collective excitations and boundary phenomena such as isolated Weyl fermions are predicted.

Fundamental piezo-Hall coefficients of single crystal p-type 3C-SiC for arbitrary crystallographic orientation

Science.gov (United States)

Qamar, Afzaal; Dao, Dzung Viet; Phan, Hoang-Phuong; Dinh, Toan; Dimitrijev, Sima

2016-08-01

Piezo-Hall effect in a single crystal p-type 3C-SiC, grown by LPCVD process, has been characterized for various crystallographic orientations. The quantified values of the piezo-Hall effect in heavily doped p-type 3C-SiC(100) and 3C-SiC(111) for different crystallographic orientations were used to obtain the fundamental piezo-Hall coefficients, P 12 = ( 5.3 ± 0.4 ) × 10 - 11 Pa - 1 , P 11 = ( - 2.6 ± 0.6 ) × 10 - 11 Pa - 1 , and P 44 = ( 11.42 ± 0.6 ) × 10 - 11 Pa - 1 . Unlike the piezoresistive effect, the piezo-Hall effect for (100) and (111) planes is found to be independent of the angle of rotation of the device within the crystal plane. The values of fundamental piezo-Hall coefficients obtained in this study can be used to predict the piezo-Hall coefficients in any crystal orientation which is very important for designing of 3C-SiC Hall sensors to minimize the piezo-Hall effect for stable magnetic field sensitivity.

Interactive case-based learning improves resident knowledge and confidence in reproductive endocrinology and infertility.

Science.gov (United States)

Goldman, Kara N; Tiegs, Ashley W; Uquillas, Kristen; Nachtigall, Margaret; Fino, M Elizabeth; Winkel, Abigail F; Lerner, Veronica

2017-06-01

Resident physicians' scores on the REI section of the CREOG exam are traditionally low, and nearly 40% of house staff nation-wide perceive their REI knowledge to be poor. We aimed to assess whether an interactive case-based group-learning curriculum would narrow the REI knowledge gap by improving understanding and retention of core REI concepts under the time constraints affecting residents. A three-hour case-based workshop was developed to address four primary CREOG objectives. A multiple-choice test was administered immediately before and after the intervention and 7 weeks post-workshop, to evaluate both knowledge and confidence. Following the intervention, residents self-reported increased confidence with counseling and treatment of PCOS, ovulation induction cycle monitoring, counseling and treatment of POI, and breaking bad news related to infertility (p < 0.05). The multiple-choice exam was re-administered 7 weeks post-intervention, and scores remained significantly improved compared to pre-workshop scores (p < 0.05). At that time, all residents either strongly agreed (91.7%) or agreed (8.3%) that the case-based interactive format was preferable to traditional lecture-based teaching. In conclusion, a nontraditional curriculum aimed at teaching core REI concepts to residents through interactive case-based learning can be successfully integrated into a residency curriculum, and significantly improves knowledge and confidence of critical concepts in REI.

Hall-magnetohydrodynamic waves in flowing ideal incompressible solar-wind plasmas

International Nuclear Information System (INIS)

Zhelyazkov, I

2010-01-01

It is well established now that the solar atmosphere, from the photosphere to the corona and the solar wind, is a highly structured medium. Satellite observations have confirmed the presence of steady flows there. Here, we investigate the propagation of magnetohydrodynamic (MHD) eigenmodes (kink and sausage surface waves) travelling along an ideal incompressible flowing plasma cylinder (flux tube) surrounded by a flowing plasma environment in the framework of the Hall magnetohydrodynamics. The propagation characteristics of the waves are studied in a reference frame moving with the mass flow outside the tube. In general, the flows change the waves' phase velocities compared with their magnitudes in a static MHD flux tube and the Hall effect extends the number of the possible wave dispersion curves. It turns out that while the kink waves, considered in the context of the standard magnetohydrodynamics, are unstable against the Kelvin-Helmholtz instability, they become stable when the Hall term in the generalized Ohm's law is taken into account. The sausage waves are stable in both considerations. All results concerning the waves' propagation and their stability/instability status are obtained on the basis of the linearized Hall-magnetohydrodynamic equations and are applicable mainly to the solar wind plasmas.

A New Design of a Single-Device 3D Hall Sensor: Cross-Shaped 3D Hall Sensor

Directory of Open Access Journals (Sweden)

Wei Tang

2018-04-01

Full Text Available In this paper, a new single-device three-dimensional (3D Hall sensor called a cross-shaped 3D Hall device is designed based on the five-contact vertical Hall device. Some of the device parameters are based on 0.18 μm BCDliteTM technology provided by GLOBALFOUNDRIES. Two-dimensional (2D and 3D finite element models implemented in COMSOL are applied to understand the device behavior under a constant magnetic field. Besides this, the influence of the sensing contacts, active region’s depth, and P-type layers are taken into account by analyzing the distribution of the voltage along the top edge and the current density inside the devices. Due to the short-circuiting effect, the sensing contacts lead to degradation in sensitivities. The P-type layers and a deeper active region in turn are responsible for the improvement of sensitivities. To distinguish the P-type layer from the active region which plays the dominant role in reducing the short-circuiting effect, the current-related sensitivity of the top edge (Stop is defined. It is found that the short-circuiting effect fades as the depth of the active region grows. Despite the P-type layers, the behavior changes a little. When the depth of the active region is 7 μm and the thickness of the P-type layers is 3 μm, the sensitivities in the x, y, and z directions can reach 91.70 V/AT, 92.36 V/AT, and 87.10 V/AT, respectively.

Quantum spin/valley Hall effect and topological insulator phase transitions in silicene

KAUST Repository

Tahir, M.

2013-04-26

We present a theoretical realization of quantum spin and quantum valley Hall effects in silicene. We show that combination of an electric field and intrinsic spin-orbit interaction leads to quantum phase transitions at the charge neutrality point. This phase transition from a two dimensional topological insulator to a trivial insulating state is accompanied by a quenching of the quantum spin Hall effect and the onset of a quantum valley Hall effect, providing a tool to experimentally tune the topological state of silicene. In contrast to graphene and other conventional topological insulators, the proposed effects in silicene are accessible to experiments.

Quantum spin/valley Hall effect and topological insulator phase transitions in silicene

KAUST Repository

Tahir, M.; Manchon, Aurelien; Sabeeh, K.; Schwingenschlö gl, Udo

2013-01-01

We present a theoretical realization of quantum spin and quantum valley Hall effects in silicene. We show that combination of an electric field and intrinsic spin-orbit interaction leads to quantum phase transitions at the charge neutrality point. This phase transition from a two dimensional topological insulator to a trivial insulating state is accompanied by a quenching of the quantum spin Hall effect and the onset of a quantum valley Hall effect, providing a tool to experimentally tune the topological state of silicene. In contrast to graphene and other conventional topological insulators, the proposed effects in silicene are accessible to experiments.

Can Hall effect trigger Kelvin-Helmholtz instability in sub-Alfvénic flows?

Science.gov (United States)

Pandey, B. P.

2018-05-01

In the Hall magnetohydrodynamics, the onset condition of the Kelvin-Helmholtz instability is solely determined by the Hall effect and is independent of the nature of shear flows. In addition, the physical mechanism behind the super- and sub-Alfvénic flows becoming unstable is quite different: the high-frequency right circularly polarized whistler becomes unstable in the super-Alfvénic flows whereas low-frequency, left circularly polarized ion-cyclotron wave becomes unstable in the presence of sub-Alfvénic shear flows. The growth rate of the Kelvin-Helmholtz instability in the super-Alfvénic case is higher than the corresponding ideal magnetohydrodynamic rate. In the sub-Alfvénic case, the Hall effect opens up a new, hitherto inaccessible (to the magnetohydrodynamics) channel through which the partially or fully ionized fluid can become Kelvin-Helmholtz unstable. The instability growth rate in this case is smaller than the super-Alfvénic case owing to the smaller free shear energy content of the flow. When the Hall term is somewhat smaller than the advection term in the induction equation, the Hall effect is also responsible for the appearance of a new overstable mode whose growth rate is smaller than the purely growing Kelvin-Helmholtz mode. On the other hand, when the Hall diffusion dominates the advection term, the growth rate of the instability depends only on the Alfvén -Mach number and is independent of the Hall diffusion coefficient. Further, the growth rate in this case linearly increases with the Alfvén frequency with smaller slope for sub-Alfvénic flows.

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)

Carl Gustav Jung and Granville Stanley Hall on Religious Experience.

Science.gov (United States)

Kim, Chae Young

2016-08-01

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

Spin Hall effect transistor

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

Structure of the electromagnetic field in three-dimensional Hall magnetohydrodynamic turbulence

International Nuclear Information System (INIS)

Dmitruk, Pablo; Matthaeus, W.H.

2006-01-01

Numerical simulations of freely evolving three-dimensional compressible magnetohydrodynamics (MHD) are performed, with and without the Hall term in Ohm's law. The parameter controlling the presence of the Hall term is the ratio of the ion skin depth to the macroscopic scale of the turbulence. The ion skin depth is set to be slightly larger than the dissipation length scale (controlled by the resistivity) for the Hall MHD simulations, while it is set to zero for non-Hall MHD simulations. Small initial cross helicity, hybrid helicity, and magnetic helicity are considered. The system is left to evolve for a few turbulent characteristic times and the magnetic field and electric field are analyzed in real and wavenumber space. Distributions (histograms) of the fields are also computed. It is found that the turbulent magnetic field (as well as the velocity field) is almost unaffected by the presence of the Hall term, while the electric field is affected at scales smaller than the ion skin depth, that is, close to the dissipation range in these simulations. The importance of each term in Ohm's law for the electric field is analyzed in wavenumber space. Furthermore, reconnection-like zones are identified, where the importance of each term in Ohm's law can be seen in real space. Reconnection-like zones with magnetic field B=0 (or small) and B≠0 are found within the turbulent state of the system

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.

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

Comparisons of auditorium acoustics measurements as a function of location in halls (A)

DEFF Research Database (Denmark)

Bradley, J. S.; Gade, Anders Christian; Siebein, G W

1993-01-01

In a measurement tour of nine U.S. concert halls measurements were made at 30 or more combinations of source and receiver position in each hall. Each of the three measurement teams (the University of Florida, the Danish Technical University, and the National Research Council of Canada) made paral....... The measurement results were also used to examine the influence of different measurement equipment and measurement procedures on the within hall variations of the various acoustical quantities. [Work partially supported by the Concert Hall Research Group.]...... parallel measurements of a number of modern room acoustics quantities using different equipment and measurement procedures. These results are compared on a seat-by-seat basis and the differences are explained in terms of earlier systematic studies of the effects of measurement procedure details...

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...

High precision micro-scale Hall Effect characterization method using in-line micro four-point probes

DEFF Research Database (Denmark)

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

2008-01-01

Accurate characterization of ultra shallow junctions (USJ) is important in order to understand the principles of junction formation and to develop the appropriate implant and annealing technologies. We investigate the capabilities of a new micro-scale Hall effect measurement method where Hall...... effect is measured with collinear micro four-point probes (M4PP). We derive the sensitivity to electrode position errors and describe a position error suppression method to enable rapid reliable Hall effect measurements with just two measurement points. We show with both Monte Carlo simulations...... and experimental measurements, that the repeatability of a micro-scale Hall effect measurement is better than 1 %. We demonstrate the ability to spatially resolve Hall effect on micro-scale by characterization of an USJ with a single laser stripe anneal. The micro sheet resistance variations resulting from...

Effect of anisotropy on anomalous Hall effect in Tb-Fe thin films

International Nuclear Information System (INIS)

Babu, V. Hari; Markandeyulu, G.; Subrahmanyam, A.

2009-01-01

The electrical and Hall resistivities of Tb x Fe 100-x thin films in the temperature range 13-300 K were investigated. The sign of Hall resistivity at 300 K is found to change from positive for x=28 film to negative for x=30 film, in accordance with the compensation of Tb and Fe moments. All the films are seen to have planar magnetic anisotropy at 13 K. The temperature coefficients of electrical resistivities of the amorphous films with 19≤x≤51 are seen to be negative. The temperature dependence of Hall resistivity of these films is explained on the basis of random magnetic anisotropy model. The temperature dependences of Hall resistivities of the x=22 and 41 films are seen to exhibit a nonmonotonous behavior due to change in anisotropy from perpendicular to planar. The same behavior is considered for the explanation regarding the probable formation of Berry phase curvature in these films.

Welcome to USA 15, the first large underground hall for the LHC

CERN Multimedia

2001-01-01

The first of the four huge underground halls for LHC is ready. USA 15 will be the service hall for ATLAS. It has taken three years to finish the first underground hall for LHC. It is 62 metres long and 20 metres diameter. USA 15 could be called the 'new world' for LHC construction. Although the acronym has nothing to do with the United States. In the terminology of the underground construction for the future accelerator, USA stands for Underground Service ATLAS. This is the first of the four big underground halls for LHC to be finished. Wednesday 8 August, it was officially handed over to the ST division by the collaboration of contractors and consultants who carried out the work. These are CCC (CERN civil contractors) composed of the companies Porr-Asdag (Austria), Baresel (Germany) and Zschokke-Locher (Switzerland) and the consultant EDF-KP composed of EDF (France) and Knight and Piésold (United Kingdom). For three years these firms excavated and concreted the undergro...

Hall and ion slip effects on peristaltic flow of Jeffrey nanofluid with Joule heating

Energy Technology Data Exchange (ETDEWEB)

Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); NAAM Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Shafique, Maryam [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Tanveer, A., E-mail: anum@math.qau.edu.pk [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alsaedi, A. [NAAM Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2016-06-01

This paper addresses mixed convective peristaltic flow of Jeffrey nanofluid in a channel with complaint walls. The present investigation includes the viscous dissipation, thermal radiation and Joule heating. Hall and ion slip effects are also taken into account. Related problems through long wavelength and low Reynolds number are examined for stream function, temperature and concentration. Impacts of thermal radiation, Hartman number, Brownian motion parameter, thermophoresis, Joule heating, Hall and ion slip parameters are investigated in detail. It is observed that velocity increases and temperature decreases with Hall and ion slip parameters. Further the thermal radiation on temperature has qualitatively similar role to that of Hall and ion slip effects. - Highlights: • Peristalsis in the presence of Jeffery nanofluid is formulated. • Compliant properties of channel walls are addressed. • Impact of Hall and ion slip effects is outlined. • Influence of Joule heating and radiation is investigated. • Mixed convection for both heat and mass transfer is present.

Magnetoresistivity and Hall resistivity of a YBCO thin film in a tilted magnetic field

International Nuclear Information System (INIS)

Amirfeiz, M.; Cimberle, M. R.; Ferdeghini, C.; Giannini, E.; Grassano, G.; Marre', D.; Putti, M.; Siri, A. S.

1997-01-01

In this paper they present magnetoresistivity and Hall effect measurements performed on a YBCO epitaxial film as a function of the angle θ between the external magnetic field and the a-b planes. The resistivity and Hall effect measurements are analyzed in term of the general scaling approach proposed by Blatter and coworkers; the Hall conductivity data are examined to separate the contributions due to vortices and quasi particles

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.

Tritium monitoring within the reactor hall of a DT fusion reactor

International Nuclear Information System (INIS)

Jalbert, R.A.

1983-01-01

Monitoring the reactor hall atmosphere of DT-fueled fusion reactors will probably be performed with conventional ion chamber and proportional counter instruments modified as necessry to deal with the background radiation. Background includes external neutron and gamma radiation and internal beta-gamma radiation from the activated atmosphere. Although locating instruments in remote areas of the reactor hall and adding local shielding and electronic compensation may be feasible, placing the instruments in accessible low-background areas outside of the reactor hall and doing remote sampling is preferable and solves most of the radiation problems. The remaining problem of the activated atmosphere may be solved by recently developed instruments in conjunction with the use of semi-permeable membranes currently under development and evaluation

Hall MHD Modeling of Two-dimensional Reconnection: Application to MRX Experiment

International Nuclear Information System (INIS)

Lukin, V.S.; Jardin, S.C.

2003-01-01

Two-dimensional resistive Hall magnetohydrodynamics (MHD) code is used to investigate the dynamical evolution of driven reconnection in the Magnetic Reconnection Experiment (MRX). The initial conditions and dimensionless parameters of the simulation are set to be similar to the experimental values. We successfully reproduce many features of the time evolution of magnetic configurations for both co- and counter-helicity reconnection in MRX. The Hall effect is shown to be important during the early dynamic X-phase of MRX reconnection, while effectively negligible during the late ''steady-state'' Y-phase, when plasma heating takes place. Based on simple symmetry considerations, an experiment to directly measure the Hall effect in MRX configuration is proposed and numerical evidence for the expected outcome is given

The electronic residency application service application can predict accreditation council for graduate medical education competency-based surgical resident performance.

Science.gov (United States)

Tolan, Amy M; Kaji, Amy H; Quach, Chi; Hines, O Joe; de Virgilio, Christian

2010-01-01

Program directors often struggle to determine which factors in the Electronic Residency Application Service (ERAS) application are important in the residency selection process. With the establishment of the Accreditation Council for Graduate Medical Education (ACGME) competencies, it would be important to know whether information available in the ERAS application can predict subsequent competency-based performance of general surgery residents. This study is a retrospective correlation of data points found in the ERAS application with core competency-based clinical rotation evaluations. ACGME competency-based evaluations as well as technical skills assessment from all rotations during residency were collected. The overall competency score was defined as an average of all 6 competencies and technical skills. A total of77 residents from two (one university and one community based university-affiliate) general surgery residency programs were included in the analysis. Receiving honors for many of the third year clerkships and AOA membership were associated with a number of the individual competencies. USMLE scores were predictive only of Medical Knowledge (p = 0.004). Factors associated with higher overall competency were female gender (p = 0.02), AOA (p = 0.06), overall number of honors received (p = 0.04), and honors in Ob/Gyn (p = 0.03) and Pediatrics (p = 0.05). Multivariable analysis showed honors in Ob/Gyn, female gender, older age, and total number of honors to be predictive of a number of individual core competencies. USMLE scores were only predictive of Medical Knowledge. The ERAS application is useful for predicting subsequent competency based performance in surgical residents. Receiving honors in the surgery clerkship, which has traditionally carried weight when evaluating a potential surgery resident, may not be as strong a predictor of future success. Copyright © 2010 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights

Noodles, traditionally and today

Directory of Open Access Journals (Sweden)

Na Zhang

2016-09-01

Full Text Available Chinese noodles originated in the Han dynasty, which has more than 4,000 years of history. There are many stories about the origin of noodles. To a certain extent, noodles also reflect the cultural traditions and customs of China, which essentially means “human nature” and “worldly common sense”. There are thousands of varieties of noodles in China, according to the classification of the shape of noodles, seasoning gravy, cooking craft, and so on. Many noodles have local characteristics. Noodles are accepted by people from all over the world. The industrial revolution and the development of the food industry realized the transition from a traditional handicraft industry to mass production using machinery. In addition, the invention of instant noodles and their mass production also greatly changed the noodle industry. In essence, noodles are a kind of cereal food, which is the main body of the traditional Chinese diet. It is the main source of energy for Chinese people and the most economical energy food. Adhering to the principle of “making cereal food the main food”, is to maintain our Chinese good diet tradition, which can avoid the disadvantages of a high energy, high fat, and low carbohydrate diet, and promote health. The importance of the status of noodles in the dietary structure of residents in our country and the health impact should not be ignored.

Facility Energy Performance Benchmarking in a Data-Scarce Environment

Science.gov (United States)

2017-08-01

0.10 0.43 Commercial Studies Barracks Dining Facilities Vehicle Maintenance CBECS - 2003 •Dormitory •Fraternity •Sorority • Restaurant •Cafeteria...Vehicle service/repair shop CTS •Residence Hall/Dormitory •Food service • Restaurant /cafeteria •Vehicle service/repair •Vehicle DC - 2013 •Residence...Hall/Dormitory N/A N/A NYC - 2013 •Residence Hall/Dormitory • Restaurant •Food service •Automobile dealership CEUS •Lodging • Restaurant N/A CEC

Scaling of the anomalous Hall current in Fe100−x(SiO2)x films

KAUST Repository

Xu, W. J.

2011-05-20

To study the origin of the anomalous Hall effect, Fe100−x(SiO2)x granular films with a volume fraction of SiO2 (0 ⩽ x ⩽ 40.51) were fabricated using cosputtering. Hall and longitudinal resistivities were measured in the temperature range of 5–350 K with magnetic fields up to 5 T. As x increased from 0 to 40.51, the anomalous Hall resistivity and longitudinal resistivity increased by about four and three orders in magnitude, respectively. Analysis of the results revealed that the normalized anomalous Hall conductivity is a constant for all of the samples, which may suggest a scattering-independent anomalous Hall conductivity in Fe.

Hall effect mobility for SiC MOSFETs with increasing dose of nitrogen implantation into channel region

Science.gov (United States)

Noguchi, Munetaka; Iwamatsu, Toshiaki; Amishiro, Hiroyuki; Watanabe, Hiroshi; Kita, Koji; Yamakawa, Satoshi

2018-04-01

The Hall effect mobility (μHall) of the Si-face 4H-SiC metal–oxide–semiconductor field effect transistor (MOSFET) with a nitrogen (N)-implanted channel region was investigated by increasing the N dose. The μHall in the channel region was systematically examined regarding channel structures, that is, the surface and buried channels. It was experimentally demonstrated that increasing the N dose results in an improvement in μHall in the channel region due to the formation of the buried channel. However, further increase in N dose was found to decrease the μHall in the channel region, owing to the decrease in the electron mobility in the N-implanted bulk region.

Stability of the Hall sensors performance under neutron irradiation

International Nuclear Information System (INIS)

Duran, I.; Hron, M.; Stockel, J.; Viererbl, L.; Vsolak, R.; Cerva, V.; Bolshakova, I.; Holyaka, R.; Vayakis, G.

2004-01-01

A principally new diagnostic method must be developed for magnetic measurements in steady state regime of operation of fusion reactor. One of the options is the use of transducers based on Hall effect. The use of Hall sensors in ITER is presently limited by their questionable radiation and thermal stability. Issues of reliable operation in ITER like radiation and thermal environment are addressed in the paper. The results of irradiation tests of candidate Hall sensors in LVR-15 and IBR-2 experimental fission reactors are presented. Stable operation (deterioration of sensitivity below one percent) of the specially prepared sensors was demonstrated during irradiation by the total fluence of 3.10 16 n/cm 2 in IBR-2 reactor. Increasing the total neutron fluence up to 3.10 17 n/cm 2 resulted in deterioration of the best sensor's output still below 10% as demonstrated during irradiation in LVR-15 fission reactor. This level of neutron is already higher than the expected ITER life time neutron fluence for a sensor location just outside the ITER vessel. (authors)

Direct comparison of fractional and integer quantized Hall resistance

Science.gov (United States)

Ahlers, Franz J.; Götz, Martin; Pierz, Klaus

2017-08-01

We present precision measurements of the fractional quantized Hall effect, where the quantized resistance {{R}≤ft[ 1/3 \\right]} in the fractional quantum Hall state at filling factor 1/3 was compared with a quantized resistance {{R}[2]} , represented by an integer quantum Hall state at filling factor 2. A cryogenic current comparator bridge capable of currents down to the nanoampere range was used to directly compare two resistance values of two GaAs-based devices located in two cryostats. A value of 1-(5.3  ±  6.3) 10-8 (95% confidence level) was obtained for the ratio ({{R}≤ft[ 1/3 \\right]}/6{{R}[2]} ). This constitutes the most precise comparison of integer resistance quantization (in terms of h/e 2) in single-particle systems and of fractional quantization in fractionally charged quasi-particle systems. While not relevant for practical metrology, such a test of the validity of the underlying physics is of significance in the context of the upcoming revision of the SI.

Status of the MIT-Bates South Hall Ring commissioning

International Nuclear Information System (INIS)

Flanz, J.B.; Jacobs, K.D.; McAllister, B.; Averill, R.; Bradley, S.; Carter, A.; Dow, K.; Farkondeh, M.; Ihloff, E.; Kowalski, S.

1993-01-01

The MIT-Bates South Hall Ring construction project is now nearly complete. At this time the Energy Compression System, the SHR Injection Line and the South Hall Ring itself are complete. The SHR Extraction Line is complete but has not been connected to the ring. Commissioning with beam of the completed beam lines has been started. The MIT-Bates South Hall Ring (SHR) is an electron storage ring used with the 1 GeV Bates electron accelerator to increase the effective duty factor and luminosity. A beam can be stored for use with an internal target, thus allowing for high duty factor, high luminosity experiments. External beams with high duty factor can be obtained using resonant extraction. The new systems associated with the SHR include the Energy Compression System (ECS), the Injection line, and the Extraction line. The authors have commissioned the ECS, the new injection line and the SHR without RF. This includes transporting beam, measuring beam phase space parameters using critical injection elements including a high voltage electrostatic septum, a fast beam kicker, and storing a beam in the SHR

Framing anomaly in the effective theory of the fractional quantum Hall effect.

Science.gov (United States)

Gromov, Andrey; Cho, Gil Young; You, Yizhi; Abanov, Alexander G; Fradkin, Eduardo

2015-01-09

We consider the geometric part of the effective action for the fractional quantum Hall effect (FQHE). It is shown that accounting for the framing anomaly of the quantum Chern-Simons theory is essential to obtain the correct gravitational linear response functions. In the lowest order in gradients, the linear response generating functional includes Chern-Simons, Wen-Zee, and gravitational Chern-Simons terms. The latter term has a contribution from the framing anomaly which fixes the value of thermal Hall conductivity and contributes to the Hall viscosity of the FQH states on a sphere. We also discuss the effects of the framing anomaly on linear responses for non-Abelian FQH states.

Spin precession and spin Hall effect in monolayer graphene/Pt nanostructures

Science.gov (United States)

Savero Torres, W.; Sierra, J. F.; Benítez, L. A.; Bonell, F.; Costache, M. V.; Valenzuela, S. O.

2017-12-01

Spin Hall effects have surged as promising phenomena for spin logics operations without ferromagnets. However, the magnitude of the detected electric signals at room temperature in metallic systems has been so far underwhelming. Here, we demonstrate a two-order of magnitude enhancement of the signal in monolayer graphene/Pt devices when compared to their fully metallic counterparts. The enhancement stems in part from efficient spin injection and the large spin resistance of graphene but we also observe 100% spin absorption in Pt and find an unusually large effective spin Hall angle of up to 0.15. The large spin-to-charge conversion allows us to characterise spin precession in graphene under the presence of a magnetic field. Furthermore, by developing an analytical model based on the 1D diffusive spin-transport, we demonstrate that the effective spin-relaxation time in graphene can be accurately determined using the (inverse) spin Hall effect as a means of detection. This is a necessary step to gather full understanding of the consequences of spin absorption in spin Hall devices, which is known to suppress effective spin lifetimes in both metallic and graphene systems.

Magnetotransport properties of Ni-Mn-In Heusler Alloys: Giant Hall angle

Energy Technology Data Exchange (ETDEWEB)

Dubenko, I; Pathak, A K; Ali, N [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Kovarskii, Y A; Prudnikov, V N; Perov, N S; Granovsky, A B, E-mail: granov@magn.r [Faculty of Physics, Moscow State University, Moscow, 111991 (Russian Federation)

2010-01-01

We report experimental results on phase transitions, magnetic properties, resistivity, and Hall effect in Ni{sub 50}Mn{sub 50-x}In{sub x} (15Hall resistivity {rho}{sub H}(at H = 15 kOe) is positive in martensitic and negative in austenitic phase, sharply increases in the vicinity of T{sub M} up to {rho}{sub H}(15 kOe)= 50 {mu}{Omega}{center_dot}cm. This value is almost two orders of magnitude larger than that observed at high temperature (T{approx}200 K) for any common magnetic materials, and comparable to the giant Hall effect resistivity in magnetic nanogranular alloys. The Hall angle {Theta}{sub H}=tan{sup -} {sup 1}({rho}{sub H}/{rho}) close to T{sub M} reaches tan{sup -1}(0.5) which is the highest value for known magnetic materials.

Experimental approach of plasma supersonic expansion physics and of Hall effect propulsion systems

International Nuclear Information System (INIS)

Mazouffre, Stephane

2009-01-01

This report for accreditation to supervise research (HDR) proposes a synthesis of scientific and research works performed by the author during about ten years. Thus, a first part addresses studies on plasma rarefied supersonic flows: expansion through a sonic hole and through a Laval nozzle. The next part addresses the study of plasma propulsion for spacecraft, and more particularly electric propulsion based on the Hall effect: phenomena of ionic and atomic transport, characteristics of the electric field, energy deposition on walls, basic scale laws, related works, hybrid Hall-RF propulsion systems. The third part presents perspectives and projects related to propulsion by Hall effect (research topics, planned researches, a European project on high power, hybrid Hall-RF propulsion) and to ions-ions plasma (the PEGASES concept, the NExET test installation, RF source of negative ions and magnetic trap)

Unconventional scaling of the anomalous Hall effect accompanying electron localization correction in the dirty regime

KAUST Repository

Lu, Y. M.

2013-03-05

Scaling of the anomalous Hall conductivity to longitudinal conductivity σAH∝σ2xx has been observed in the dirty regime of two-dimensional weak and strong localization regions in ultrathin, polycrystalline, chemically disordered, ferromagnetic FePt films. The relationship between electron transport and temperature reveals a quantitatively insignificant Coulomb interaction in these films, while the temperature dependent anomalous Hall conductivity experiences quantum correction from electron localization. At the onset of this correction, the low-temperature anomalous Hall resistivity begins to be saturated when the thickness of the FePt film is reduced, and the corresponding Hall conductivity scaling exponent becomes 2, which is above the recent unified theory of 1.6 (σAH∝σ1.6xx). Our results strongly suggest that the correction of the electron localization modulates the scaling exponent of the anomalous Hall effect.

The Interactive Candidate Assessment Tool: A New Way to Interview Residents.

Science.gov (United States)

Platt, Michael P; Akhtar-Khavari, Vafa; Ortega, Rafael; Schneider, Jeffrey I; Fineberg, Tabitha; Grundfast, Kenneth M

2017-06-01

The purpose of the residency interview is to determine the extent to which a well-qualified applicant is a good fit with a residency program. However, questions asked during residency interviews tend to be standard and repetitive, and they may not elicit information that best differentiates one applicant from another. The iCAT (interactive Candidate Assessment Tool) is a novel interview instrument that allows both interviewers and interviewees to learn about each other in a meaningful way. The iCAT uses a tablet computer to enable the candidate to select questions from an array of video and nonvideo vignettes. Vignettes include recorded videos regarding some aspect of the program, while other icons include questions within recognizable categories. Postinterview surveys demonstrated advantages over traditional interview methods, with 93% agreeing that it was an innovative and effective tool for conducting residency program interviews. The iCAT for residency interviews is a technological advancement that facilitates in-depth candidate assessment.

Development of a micro-Hall magnetometer and studies of individual Fe-filled carbon nanotubes

OpenAIRE

Lipert, Kamil

2011-01-01

This work presents Hall magnetometry studies on individual Fe-filled carbon nanotubes (CNT). For this approach high sensitivity micro Hall sensors based on a GaAs/AlGaAs heterostructure with two dimensional electron gas (2DEG) were developed. Electron beam lithography and wet chemical etching were utilized for patterning Hall sensors onto the heterostructure surface. The devices were characterized by means of scanning electron microscopy, atomic force microscopy and transport measurements. In...

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 ...

Quantum Hall effect

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

Generic superweak chaos induced by Hall effect

Science.gov (United States)

Ben-Harush, Moti; Dana, Itzhack

2016-05-01

We introduce and study the "kicked Hall system" (KHS), i.e., charged particles periodically kicked in the presence of uniform magnetic (B ) and electric (E ) fields that are perpendicular to each other and to the kicking direction. We show that for resonant values of B and E and in the weak-chaos regime of sufficiently small nonintegrability parameter κ (the kicking strength), there exists a generic family of periodic kicking potentials for which the Hall effect from B and E significantly suppresses the weak chaos, replacing it by "superweak" chaos (SWC). This means that the system behaves as if the kicking strength were 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.

The Flipped Classroom: A Modality for Mixed Asynchronous and Synchronous Learning in a Residency Program

Directory of Open Access Journals (Sweden)

Timothy P. Young

2014-11-01

Full Text Available Introduction: A “flipped classroom” educational model exchanges the traditional format of a classroom lecture and homework problem set. We piloted two flipped classroom sessions in our emergency medicine (EM residency didactic schedule. We aimed to learn about resident and faculty impressions of the sessions, in order to develop them as a regular component of our residency curriculum. Methods: We evaluated residents’ impression of the asynchronous video component and synchronous classroom component using four Likert items. We used open-ended questions to inquire about resident and faculty impressions of the advantages and disadvantages of the format. Results: For the Likert items evaluating the video lectures, 33/35 residents (94%, 95% CI 80%-99% responded that the video lecture added to their knowledge about the topic, and 33/35 residents felt that watching the video was a valuable use of their time. For items evaluating the flipped classroom format, 36/38 residents (95%, 95% CI 82%-99% preferred the format to a traditional lecture on the topic, and 38/38 residents (100%, 95% CI 89%-100% felt that the small group session was effective in helping them learn about the topic. Most residents preferred to see the format monthly in our curriculum and chose an ideal group size of 5.5 (first session and 7 (second session. Residents cited the interactivity of the sessions and access to experts as advantages of the format. Faculty felt the ability to assess residents’ understanding of concepts and provide feedback were advantages. Conclusion: Our flipped classroom model was positively received by EM residents. Residents preferred a small group size and favored frequent use of the format in our curriculum. The flipped classroom represents one modality that programs may use to incorporate a mixture of asynchronous and interactive synchronous learning and provide additional opportunities to evaluate residents. [West J Emerg Med. 2014;15(7:-0.

Comment on 'Effects of Magnetic Field Gradient on Ion Beam Current in Cylindrical Hall Ion Source

International Nuclear Information System (INIS)

Raitses, Y.; Smirnov A.; Fisch, N.J.

2008-01-01

It is argued that the key difference of the cylindrical Hall thruster (CHT) as compared to the end-Hall ion source cannot be exclusively attributed to the magnetic field topology [Tang et al. J. Appl. Phys., 102, 123305 (2007)]. With a similar mirror-type topology, the CHT configuration provides the electric field with nearly equipotential magnetic field surfaces and a better suppression of the electron cross-field transport, as compared to both the end-Hall ion source and the cylindrical Hall ion source of Tang et al

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.

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

Exchange magnon induced resistance asymmetry in permalloy spin-Hall oscillators

Energy Technology Data Exchange (ETDEWEB)

Langenfeld, S. [Microelectronics Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE (United Kingdom); Walter Schottky Institut and Physik-Department, Technische Universität München, 85748 Garching (Germany); Tshitoyan, V.; Fang, Z.; Ferguson, A. J., E-mail: ajf1006@cam.ac.uk [Microelectronics Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE (United Kingdom); Wells, A.; Moore, T. A. [School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT (United Kingdom)

2016-05-09

We investigate magnetization dynamics in a spin-Hall oscillator using a direct current measurement as well as conventional microwave spectrum analysis. When the current applies an anti-damping spin-transfer torque, we observe a change in resistance which we ascribe mainly to the excitation of incoherent exchange magnons. A simple model is developed based on the reduction of the effective saturation magnetization, quantitatively explaining the data. The observed phenomena highlight the importance of exchange magnons on the operation of spin-Hall oscillators.

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

Quantum Hall effect and hopping conductivity in n-InGaAs/InAlAs nanoheterostructures

Energy Technology Data Exchange (ETDEWEB)

Gudina, S. V., E-mail: svpopova@imp.uran.ru; Arapov, Yu. G.; Saveliev, A. P.; Neverov, V. N.; Podgornykh, S. M.; Shelushinina, N. G.; Yakunin, M. V. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation); Vasil’evskii, I. S.; Vinichenko, A. N. [National Research Nuclear University MEPhI (Russian Federation)

2016-12-15

The longitudinal and Hall magnetoresistances are measured in the quantum Hall effect regime in the n-InGaAs/InAlAs heterostructures at temperatures of T = (1.8–30) K in magnetic fields up to B = 9 T. Temperature-induced transport in the region of the longitudinal resistance minima, corresponding to the plateau regions at Hall resistance, is investigated within the framework of the concept of hopping conductivity in a strongly localized electron system. The analysis of variable-range hopping conductivity in the region of the second, third, and fourth plateau of the quantum Hall effect provides the possibility of determining the localization length exponent.

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

Hall Current Plasma Source Having a Center-Mounted or a Surface-Mounted Cathode

Science.gov (United States)

Martinez, Rafael A. (Inventor); Williams, John D. (Inventor); Moritz, Jr., Joel A. (Inventor); Farnell, Casey C. (Inventor)

2018-01-01

A miniature Hall current plasma source apparatus having magnetic shielding of the walls from ionized plasma, an integrated discharge channel and gas distributor, an instant-start hollow cathode mounted to the plasma source, and an externally mounted keeper, is described. The apparatus offers advantages over other Hall current plasma sources having similar power levels, including: lower mass, longer lifetime, lower part count including fewer power supplies, and the ability to be continuously adjustable to lower average power levels using pulsed operation and adjustment of the pulse duty cycle. The Hall current plasma source can provide propulsion for small spacecraft that either do not have sufficient power to accommodate a propulsion system or do not have available volume to incorporate the larger propulsion systems currently available. The present low-power Hall current plasma source can be used to provide energetic ions to assist the deposition of thin films in plasma processing applications.

Precision Electron Beam Polarimetry in Hall C at Jefferson Lab

Science.gov (United States)

Gaskell, David

2013-10-01

The electron beam polarization in experimental Hall C at Jefferson Lab is measured using two devices. The Hall-C/Basel Møller polarimeter measures the beam polarization via electron-electron scattering and utilizes a novel target system in which a pure iron foil is driven to magnetic saturation (out of plane) using a superconducting solenoid. A Compton polarimeter measures the polarization via electron-photon scattering, where the photons are provided by a high-power, CW laser coupled to a low gain Fabry-Perot cavity. In this case, both the Compton-scattered electrons and backscattered photons provide measurements of the beam polarization. Results from both polarimeters, acquired during the Q-Weak experiment in Hall C, will be presented. In particular, the results of a test in which the Møller and Compton polarimeters made interleaving measurements at identical beam currents will be shown. In addition, plans for operation of both devices after completion of the Jefferson Lab 12 GeV Upgrade will also be discussed.

Hall kirjandus võrgustunud maailmas / Anneli Kuiv

Index Scriptorium Estoniae

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"

Nonlinear response of the quantum Hall system to a strong electromagnetic radiation

International Nuclear Information System (INIS)

Avetissian, H.K.; Mkrtchian, G.F.

2016-01-01

We study nonlinear response of a quantum Hall system in semiconductor-hetero-structures via third harmonic generation process and nonlinear Faraday effect. We demonstrate that Faraday rotation angle and third harmonic radiation intensity have a characteristic Hall plateaus feature. These nonlinear effects remain robust against the significant broadening of Landau levels. We predict realization of an experiment through the observation of the third harmonic signal and Faraday rotation angle, which are within the experimental feasibility. - Highlights: • Nonlinear optical response of a quantum Hall system has specific plateaus feature. • This effect remains robust against the significant broadening of Landau levels. • It can be observed via the third harmonic signal and the nonlinear Faraday effect.

Hořava-Lifshitz gravity and effective theory of the fractional quantum Hall effect

Energy Technology Data Exchange (ETDEWEB)

Wu, Chaolun [Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States); Wu, Shao-Feng [Department of Physics, Shanghai University,Shanghai 200444 (China); Kadanoff Center for Theoretical Physics and Enrico Fermi Institute, University of Chicago,Chicago, Illinois 60637 (United States)

2015-01-22

We show that Hořava-Lifshitz gravity theory can be employed as a covariant framework to build an effective field theory for the fractional quantum Hall effect that respects all the spacetime symmetries such as non-relativistic diffeomorphism invariance and anisotropic Weyl invariance as well as the gauge symmetry. The key to this formalism is a set of correspondence relations that maps all the field degrees of freedom in the Hořava-Lifshitz gravity theory to external background (source) fields among others in the effective action of the quantum Hall effect, according to their symmetry transformation properties. We originally derive the map as a holographic dictionary, but its form is independent of the existence of holographic duality. This paves the way for the application of Hořava-Lifshitz holography on fractional quantum Hall effect. Using the simplest holographic Chern-Simons model, we compute the low energy effective action at leading orders and show that it captures universal electromagnetic and geometric properties of quantum Hall states, including the Wen-Zee shift, Hall viscosity, angular momentum density and their relations. We identify the shift function in Hořava-Lifshitz gravity theory as minus of guiding center velocity and conjugate to guiding center momentum. This enables us to distinguish guiding center angular momentum density from the internal one, which is the sum of Landau orbit spin and intrinsic (topological) spin of the composite particles. Our effective action shows that Hall viscosity is minus half of the internal angular momentum density and proportional to Wen-Zee shift, and Hall bulk viscosity is half of the guiding center angular momentum density.

Neuroscience and humanistic psychiatry: a residency curriculum.

Science.gov (United States)

Griffith, James L

2014-04-01

Psychiatry residencies with a commitment to humanism commonly prioritize training in psychotherapy, cultural psychiatry, mental health policy, promotion of human rights, and similar areas reliant upon dialogue and collaborative therapeutic relationships. The advent of neuroscience as a defining paradigm for psychiatry has challenged residencies with a humanistic focus due to common perceptions that it would entail constriction of psychiatric practice to diagnostic and psychopharmacology roles. The author describes a neuroscience curriculum that has taught psychopharmacology effectively, while also advancing effectiveness of language-based and relationship-based therapeutics. In 2000, the George Washington University psychiatry residency initiated a neuroscience curriculum consisting of (1) a foundational postgraduate year 2 seminar teaching cognitive and social neuroscience and its integration into clinical psychopharmacology, (2) advanced seminars that utilized a neuroscience perspective in teaching specific psychotherapeutic skill sets, and (3) case-based teaching in outpatient clinical supervisions that incorporated a neuroscience perspective into traditional psychotherapy supervisions. Curricular assessment was conducted by (1) RRC reaccreditation site visit feedback, (2) examining career trajectories of residency graduates, (3) comparing PRITE exam Somatic Treatments subscale scores for 2010-2012 residents with pre-implementation residents, and (4) postresidency survey assessment by 2010-2012 graduates. The 2011 RRC site visit report recommended a "notable practice" citation for "innovative neurosciences curriculum." Three of twenty 2010-2012 graduates entered neuroscience research fellowships, as compared to none before the new curriculum. PRITE Somatic Treatments subscale scores improved from the 23rd percentile to the 62nd percentile in pre- to post-implementation of curriculum (p neuroscience curriculum for a residency committed to humanistic psychiatry

Two dimensional Hall MHD modeling of a plasma opening switch with density inhomogeneities

Energy Technology Data Exchange (ETDEWEB)

Zabaidullin, O [Kurchatov Institute, Moscow (Russian Federation); Chuvatin, A; Etlicher, B [Ecole Polytechnique, Palaiseau (France). Laboratoire de Physique des Milieux Ionises

1997-12-31

The results of two-dimensional numerical modeling of the Plasma Opening Switch in the MHD framework with Hall effect are presented. An enhanced Hall diffusion coefficient was used in the simulations. Recent experiments justify the application of this approach. The result of the modeling also correlates better with the experiment than in the case of the classical diffusion coefficient. Numerically generated pictures propose a switching scenario in which the translation between the conduction and opening phases can be explained by an abrupt `switching on` and further domination of the Hall effect at the end of the conduction phase. (author). 3 figs., 6 refs.

Detection and Solution of Indoor Air Quality Problems in a Danish Town Hall

DEFF Research Database (Denmark)

Hyldgård, Carl-Erik; Brohus, Henrik

In connection with the research programme "Healthy Buildings", a building with indoor air quality problems was selected for further investigations. A Danish town hall was chosen because of many complaints over several years. A full-scale mock-up of a typical town hall office was built...... in the climate laboratory. A new heating and ventilating system and a new control strategy were chosen and implemented into the town hall. It was found that air supply upwards along a window may make it nearly impossible to achieve comfort and a good air quality the year round without full-scale measurements....

A two-year experience of an integrated simulation residency curriculum.

Science.gov (United States)

Wittels, Kathleen A; Takayesu, James K; Nadel, Eric S

2012-07-01

Human Patient Simulation (HPS) is increasingly used in medical education, but its role in Emergency Medicine (EM) residency education is uncertain. The objective of this study was to evaluate the perceived effectiveness of HPS when fully integrated into an EM residency didactic curriculum. The study design was a cross-sectional survey performed in 2006, 2 years after the implementation of an integrated simulation curriculum. Fifty-four residents (postgraduate year [PGY] 1-4) of a 4-year EM residency were surveyed with demographic and curricular questions on the perceived value of simulation relative to other teaching formats. Survey items were rated on a bipolar linear numeric scale of 1 (strongly disagree) to 9 (strongly agree), with 5 being neutral. Data were analyzed using Student t-tests. Forty residents responded to the survey (74% response rate). The perceived effectiveness of HPS was higher for junior residents than senior residents (8.0 vs. 6.2, respectively, peffectiveness of lectures (7.8 vs. 7.9, respectively, p=0.1), morbidity and mortality conference (8.5 vs. 8.7, respectively, p=0.3), and trauma conference (8.4 vs. 8.8, respectively, p=0.2) between junior and senior residents. Scores for perceptions of improvement in residency training (knowledge acquisition and clinical decision-making) after the integration of HPS into the curriculum were positive for all residents. Residents' perceptions of HPS integration into an EM residency curriculum are positive for both improving knowledge acquisition and learning clinical decision-making. HPS was rated as more effective during junior years than senior years, while the perceived efficacy of more traditional educational modalities remained constant throughout residency training. Copyright © 2012. Published by Elsevier Inc.

The multiple mini-interview for emergency medicine resident selection.

Science.gov (United States)

Hopson, Laura R; Burkhardt, John C; Stansfield, R Brent; Vohra, Taher; Turner-Lawrence, Danielle; Losman, Eve D

2014-04-01

The Multiple Mini-Interview (MMI) uses multiple, short-structured contacts to evaluate communication and professionalism. It predicts medical school success better than the traditional interview and application. Its acceptability and utility in emergency medicine (EM) residency selection are unknown. We theorized that participants would judge the MMI equal to a traditional unstructured interview and it would provide new information for candidate assessment. Seventy-one interns from 3 programs in the first month of training completed an eight-station MMI focused on EM topics. Pre- and post-surveys assessed reactions. MMI scores were compared with application data. EM grades correlated with MMI performance (F[1, 66] = 4.18; p interview (mean difference = 1.36; p interview and MMI) was preferred over a MMI alone (mean difference = 1.1; p interview, participants were receptive to a mixed-methods interview. The MMI does correlate with performance on the EM clerkship and therefore can measure important abilities for EM success. Future work will determine whether MMI performance predicts residency performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Hall mobility maps for 4H-silicon carbide by Monte Carlo simulations

International Nuclear Information System (INIS)

Woźny, J; Lisik, Z; Podgórski, J

2014-01-01

The Monte Carlo Single Particle approach was used to analyze electron transport in 4H-SiC taking into account the influence of the magnetic field. Within the numerical approach it was possible to evaluate electron Hall mobility and the Hall factor for the wide range of donor concentrations and temperatures varying from 300 K up to 700 K

Interplay of Rashba effect and spin Hall effect in perpendicular Pt/Co/MgO magnetic multilayers

Institute of Scientific and Technical Information of China (English)

赵云驰; 杨光; 董博闻; 王守国; 王超; 孙阳; 张静言; 于广华

2016-01-01

The interplay of the Rashba effect and the spin Hall effect originating from current induced spin–orbit coupling was investigated in the as-deposited and annealed Pt/Co/MgO stacks with perpendicular magnetic anisotropy. The above two effects were analyzed based on Hall measurements under external magnetic fields longitudinal and vertical to dc current, respectively. The coercive field as a function of dc current in vertical mode with only the Rashba effect involved decreases due to thermal annealing. Meanwhile, spin orbit torques calculated from Hall resistance with only the spin Hall effect involved in the longitudinal mode decrease in the annealed sample. The experimental results prove that the bottom Pt/Co interface rather than the Co/MgO top one plays a more critical role in both Rashba effect and spin Hall effect.

Quantum Hall Electron Nematics

Science.gov (United States)

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.

Quantum Hall Conductivity and Topological Invariants

Science.gov (United States)

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.

Error modelling of quantum Hall array resistance standards

Science.gov (United States)

Marzano, Martina; Oe, Takehiko; Ortolano, Massimo; Callegaro, Luca; Kaneko, Nobu-Hisa

2018-04-01

Quantum Hall array resistance standards (QHARSs) are integrated circuits composed of interconnected quantum Hall effect elements that allow the realization of virtually arbitrary resistance values. In recent years, techniques were presented to efficiently design QHARS networks. An open problem is that of the evaluation of the accuracy of a QHARS, which is affected by contact and wire resistances. In this work, we present a general and systematic procedure for the error modelling of QHARSs, which is based on modern circuit analysis techniques and Monte Carlo evaluation of the uncertainty. As a practical example, this method of analysis is applied to the characterization of a 1 MΩ QHARS developed by the National Metrology Institute of Japan. Software tools are provided to apply the procedure to other arrays.

Extraordinary Hall-effect in colloidal magnetic nanoparticle films

Energy Technology Data Exchange (ETDEWEB)

Ben Gur, Leah; Tirosh, Einat [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Segal, Amir [School of Physics, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Markovich, Gil, E-mail: gilmar@post.tau.ac.il [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Gerber, Alexander, E-mail: gerber@post.tau.ac.il [School of Physics, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel)

2017-03-15

Colloidal nickel nanoparticles (NPs) coated with polyvinylpyrrolidone (PVP) were synthesized. The nanoparticle dispersions were deposited on substrates and dried under mild heating to form conductive films. The films exhibited very small coercivity, nearly metallic conductivity, and a significant extraordinary Hall effect signal. This method could be useful for preparing simple, printed magnetic field sensors with the advantage of relatively high sensitivity around zero magnetic field, in contrast to magnetoresistive sensors, which have maximal field sensitivity away from zero magnetic field. - Highlights: • Ni nanoparticle ink capable of forming conductive films on drying. • The Ni nanoparticle films exhibit significant extraordinary Hall effect. • This system could be used for preparing printed magnetic field sensors integrated in 3D printed structures.

Edge states in quantum Hall effect in graphene

International Nuclear Information System (INIS)

Gusynin, V.P.; Miransky, V.A.; Sharapov, S.G.; Shovkovy, I.A.

2008-01-01

We review recent results concerning the spectrum of edge states in the quantum Hall effect in graphene. In particular, special attention is paid to the derivation of the conditions under which gapless edge states exist in the spectrum of graphene with 'zigzag' and 'armchair' edges. It is found that in the case of a half-plane or a ribbon with zigzag edges, there are gapless edge states only when a spin gap dominates over a Dirac mass gap. In the case of a half-plane with an armchair edge, the existence of the gapless edge states depends on the specific type of Dirac mass gaps. The implications of these results for the dynamics in the quantum Hall effect in graphene are discussed

TH-E-201-02: Hands-On Physics Teaching of Residents in Diagnostic Radiology

Energy Technology Data Exchange (ETDEWEB)

Zhang, J. [University of Kentucky (United States)

2016-06-15

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant.

TH-E-201-02: Hands-On Physics Teaching of Residents in Diagnostic Radiology

International Nuclear Information System (INIS)

Zhang, J.

2016-01-01

The ABR Core Examination stresses integrating physics into real-world clinical practice and, accordingly, has shifted its focus from passive recall of facts to active application of physics principles. Physics education of radiology residents poses a challenge. The traditional method of didactic lectures alone is insufficient, yet it is difficult to incorporate physics teaching consistently into clinical rotations due to time constraints. Faced with this challenge, diagnostic medical physicists who teach radiology residents, have been thinking about how to adapt their teaching to the new paradigm, what to teach and meet expectation of the radiology resident and the radiology residency program. The proposed lecture attempts to discuss above questions. Newly developed diagnostic radiology residents physics curriculum by the AAPM Imaging Physics Curricula Subcommittee will be reviewed. Initial experience on hands-on physics teaching will be discussed. Radiology resident who will have taken the BAR Core Examination will share the expectation of physics teaching from a resident perspective. The lecture will help develop robust educational approaches to prepare radiology residents for safer and more effective lifelong practice. Learning Objectives: Learn updated physics requirements for radiology residents Pursue effective approaches to teach physics to radiology residents Learn expectation of physics teaching from resident perspective J. Zhang, This topic is partially supported by RSNA Education Scholar Grant

Optimal Volume for Concert Halls Based on Ando’s Subjective Preference and Barron Revised Theories

Directory of Open Access Journals (Sweden)

Salvador Cerdá

2014-03-01

Full Text Available The Ando-Beranek’s model, a linear version of Ando’s subjective preference theory, obtained by the authors in a recent work, was combined with Barron revised theory. An optimal volume region for each reverberation time was obtained for classical music in symphony orchestra concert halls. The obtained relation was tested with good agreement with the top rated halls reported by Beranek and other halls with reported anomalies.

Increasing First-Semester Student Engagement: A Residential Community Retention Study

Science.gov (United States)

Briggs, Ronald

2012-01-01

The purpose of this study was to increase first year residential student engagement and participation in residence hall programs during the 2011 fall semester at the Downtown Phoenix Campus of Arizona State University. Six upperclassmen (Taylor Place Leaders) residing in a residence hall (Taylor Place) were matched by academic major with 17 first…

Use of computers and the Internet by residents in US family medicine programmes.

Science.gov (United States)

King, Richard V; Murphy-Cullen, Cassie L; Mayo, Helen G; Marcee, Alice K; Schneider, Gregory W

2007-06-01

Computers, personal digital assistants (PDA), and the Internet are widely used as resources in medical education and clinical care. Educators who intend to incorporate these resources effectively into residency education programmes can benefit from understanding how residents currently use these tools, their skills, and their preferences. The researchers sent questionnaires to 306 US family medicine residency programmes for all of their residents to complete. Respondents were 1177 residents from 125 (41%) programmes. Access to a computer was reported by 95% of respondents. Of these, 97% of desktop and 89% of laptop computers could access the Internet. Residents accessed various educational and clinical resources. Half felt they had 'intermediate' skills at Web searches, 23% had 'some skills,' and 27% were 'quite skilled.' Those under 30 years of age reported higher skill levels. Those who experienced a Web-based curriculum in medical school reported higher search skills and greater success in finding clinical information. Respondents preferred to use technology to supplement the didactic sessions offered in resident teaching conferences. Favourable conditions exist in family medicine residency programmes to implement a blend of traditional and technology-based learning experiences. These conditions include residents' experience, skills, and preferences.

A model study of present-day Hall-effect circulators

International Nuclear Information System (INIS)

Placke, B.; Bosco, S.; DiVincenzo, D.P.

2017-01-01

Stimulated by the recent implementation of a three-port Hall-effect microwave circulator of Mahoney et al. (MEA), we present model studies of the performance of this device. Our calculations are based on the capacitive-coupling model of Viola and DiVincenzo (VD). Based on conductance data from a typical Hall-bar device obtained from a two-dimensional electron gas (2DEG) in a magnetic field, we numerically solve the coupled field-circuit equations to calculate the expected performance of the circulator, as determined by the S parameters of the device when coupled to 50Ω ports, as a function of frequency and magnetic field. Above magnetic fields of 1.5 T, for which a typical 2DEG enters the quantum Hall regime (corresponding to a Landau-level filling fraction ν of 20), the Hall angle θ_H = tan"-"1 σ_x_y/σ_x_x always remains close to 90 , and the S parameters are close to the analytic predictions of VD for θ_H = π/2. As anticipated by VD, MEA find the device to have rather high (kΩ) impedance, and thus to be extremely mismatched to 50Ω, requiring the use of impedance matching. We incorporate the lumped matching circuits of MEA in our modeling and confirm that they can produce excellent circulation, although confined to a very small bandwidth. We predict that this bandwidth is significantly improved by working at lower magnetic field when the Landau index is high, e.g. ν = 20, and the impedance mismatch is correspondingly less extreme. Our modeling also confirms the observation of MEA that parasitic port-to-port capacitance can produce very interesting countercirculation effects. (orig.)

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.

Anomalous Hall effect in ZrTe5

Science.gov (United States)

Liang, Tian; Lin, Jingjing; Gibson, Quinn; Kushwaha, Satya; Liu, Minhao; Wang, Wudi; Xiong, Hongyu; Sobota, Jonathan A.; Hashimoto, Makoto; Kirchmann, Patrick S.; Shen, Zhi-Xun; Cava, R. J.; Ong, N. P.

2018-05-01

Research in topological matter has expanded to include the Dirac and Weyl semimetals1-10, which feature three-dimensional Dirac states protected by symmetry. Zirconium pentatelluride has been of recent interest as a potential Dirac or Weyl semimetal material. Here, we report the results of experiments performed by in situ three-dimensional double-axis rotation to extract the full 4π solid angular dependence of the transport properties. A clear anomalous Hall effect is detected in every sample studied, with no magnetic ordering observed in the system to the experimental sensitivity of torque magnetometry. Large anomalous Hall signals develop when the magnetic field is rotated in the plane of the stacked quasi-two-dimensional layers, with the values vanishing above about 60 K, where the negative longitudinal magnetoresistance also disappears. This suggests a close relation in their origins, which we attribute to the Berry curvature generated by the Weyl nodes.

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.

Radioactivity and chromosome aberrations of residents of Misasa Spa

International Nuclear Information System (INIS)

Morinaga, Hiroshi; Mifune, Masaaki; Furuno, Katsushi

1985-01-01

Misasa Spa is one of the most highly radioactive hot springs in Japan, the waters of which contain mainly 222 Rn (437 ± 132 Bq/liter). Radon contents of indoor air of private houses and health resort hotels (built of wood) at Misasa Spa range from 18.5 to 55.5 mBq/liter and 22.2 to 129.5 mBq/liter, respectively. Radon contents in the air of facilities using spring waters at Misasa Branch Hospital of Okayama University were measured to be; bathroom 807 ± 78 mBq/liter; Hubbardtank bathroom 5306 ± 2568 mBq/liter; the drinking hall 1491 ± 178 mBq/liter. The environmental and dose rate inside private house's has been measured to be 14.0 ± 1.8 μR/h. Chromosome aberrations (dicentrics) in the peripheral blood lymphocytes of residents of Misasa Spa were investigated in 14 persons; the mean value of aberration frequencies were 0.21 %. (Kubozono, M.)

Hall-Effect Sensors for Real-Time Monitoring Pier Scour

Directory of Open Access Journals (Sweden)

Chen-Chia CHEN

2015-01-01

Full Text Available Scour around bridge pier is a major cause of bridge failure such as collapse resulted in loss of life and property. Most of available sensors and approaches for monitoring bridge pier scour are very expensive, which is a main challenge for mass deployment of numerous bridges. Our proposed scour monitoring system utilized low-cost commercial sensors, hall-effect sensors (unit price< $1 that are capable of real-time measuring bridge pier scour with resolution of ~ 2.5 cm, and overall cost for single sensor node of our proposed work is at least 40 % less expensive than existing work. The hall- effect sensor is evaluated under controlled conditions in two laboratory flumes. After scour event, the typical voltage change of the hall-effect sensor is ~ 300 mV, and the system achieve signal-to-noise ratio performance of ~ 60 dB. Finally, we also provide an equation to predict the time variation of scour depth around pier model. Moreover, the master-slave architecture of bridge pier scour monitoring system has scalability and flexibility for mass deployment. This technique has the potential for further widespread implementation in the field.

Strong quasi-particle tunneling study in the paired quantum Hall states

OpenAIRE

Nomura, Kentaro; Yoshioka, Daijiro

2001-01-01

The quasi-particle tunneling phenomena in the paired fractional quantum Hall states are studied. A single point-contact system is first considered. Because of relevancy of the quasi-particle tunneling term, the strong tunneling regime should be investigated. Using the instanton method it is shown that the strong quasi-particle tunneling regime is described as the weak electron tunneling regime effectively. Expanding to the network model the paired quantum Hall liquid to insulator transition i...

Prediction of a quantum anomalous Hall state in Co-decorated silicene

KAUST Repository

Kaloni, Thaneshwor P.

2014-01-09

Based on first-principles calculations, we demonstrate that Co-decorated silicene can host a quantum anomalous Hall state. The exchange field induced by the Co atoms combined with the strong spin-orbit coupling of the silicene opens a nontrivial band gap at the K point. As compared to other transition metals, Co-decorated silicene is unique in this respect, since usually hybridization and spin-polarization induced in the silicene suppress a quantum anomalous Hall state.

Prediction of a quantum anomalous Hall state in Co-decorated silicene

KAUST Repository

Kaloni, Thaneshwor P.; Schwingenschlö gl, Udo; Singh, Nirpendra

2014-01-01

Based on first-principles calculations, we demonstrate that Co-decorated silicene can host a quantum anomalous Hall state. The exchange field induced by the Co atoms combined with the strong spin-orbit coupling of the silicene opens a nontrivial band gap at the K point. As compared to other transition metals, Co-decorated silicene is unique in this respect, since usually hybridization and spin-polarization induced in the silicene suppress a quantum anomalous Hall state.

SUSTAINABLE WASTE MANAGEMENT OF TRADITIONAL CRAFT INDUSTRY IN LOPATI TOURISM VILLAGE, YOGYAKARTA

OpenAIRE

VITASURYA Vincentia Reni; PUDIANTI Anna

2016-01-01

Ecotourism has been growing in Yogyakarta that can be seen through the development of rural tourism. The development of rural tourism has positive impact to improve local community’s welfare nevertheless, it has also negative impact onto environmental carrying capacity. Lopati tourism village is located in Bantul, Yogyakarta, relying on traditional craft industry as tourism attraction. Traditional crafts are livelihood of local residents, so that environmental management efforts become part o...

Voltage transients in thin-film InSb Hall sensor

Science.gov (United States)

Bardin, Alexey; Ignatjev, Vyacheslav; Orlov, Andrey; Perchenko, Sergey

The work is reached to study temperature transients in thin-film Hall sensors. We experimentally study InSb thin-film Hall sensor. We find transients of voltage with amplitude about 10 μ V on the sensor ports after current switching. We demonstrate by direct measurements that the transients is caused by thermo-e.m.f., and both non-stationarity and heterogeneity of temperature in the film. We find significant asymmetry of temperature field for different direction of the current, which is probably related to Peltier effect. The result can be useful for wide range of scientist who works with switching of high density currents in any thin semiconductor films.

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

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.

Bingo halls and smoking: perspectives of First Nations women.

Science.gov (United States)

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.