5,463 research outputs found
Specific Plateaus of the Quantum Hall Effect Induced by an Applied Bias
The spectrum and the eigenstates of a finite 2D tight-binding electronic
system, with Dirichlet boundary conditions, in magnetic field and external
linear potential are studied. The eigenstates show an equipotential character
and may cross the plaquette in the direction perpendicular to the electric
field. When leads are added to the plaquette, the channels carrying the current
may be shortcut by equipotentials, resulting in additional plateaus situated
inbetween the usual IQHE plateaus. This idea is confirmed by a numerical
calculation within the four-terminal Landauer-B\"{u}ttiker approach.Comment: 9 pages, revtex, 2 gif figures and 5 postscript figure
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The therapist\u27s experience of psychotherapy with adult vs. adolescent patients : an empirical study.
Restructuring the Marital Bedroom: The Role of the Privacy Doctrine in Advocating the Legalization of Same-Sex Marriage
Part I of this paper examines the reasons underlying queer rights advocates\u27 reluctance to insert privacy arguments into the case for legalizing same-sex marriage. Part II illustrates that, due to such disinclination, advocates transformed notions of privacy into concepts of liberty. Part III argues that, after the Lawrence decision, proponents of same-sex marriage can and should use privacy-based arguments to fortify their claims
Restructuring the Marital Bedroom: The Role of the Privacy Doctrine in Advocating the Legalization of Same-Sex Marriage
Part I of this paper examines the reasons underlying queer rights advocates\u27 reluctance to insert privacy arguments into the case for legalizing same-sex marriage. Part II illustrates that, due to such disinclination, advocates transformed notions of privacy into concepts of liberty. Part III argues that, after the Lawrence decision, proponents of same-sex marriage can and should use privacy-based arguments to fortify their claims
Applications of thermal energy storage in the cement industry
In the manufacture of cement, literally trillions of Btu's are rejected to the environment each year. The purpose of this feasibility study program was to determine whether thermal energy storage could be used to conserve or allow alternative uses of this rejected energy. This study identifies and quantifies the sources of rejected energy in the cement manufacturing process, established use of this energy, investigates various storage system concepts, and selects energy conservation systems for further study. Thermal performance and economic analyses are performed on candidate storage systems for four typical cement plants representing various methods of manufacturing cement. Through the use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 10 to the 13th power Btu/year, or an equivalent on investment of the proposed systems are an incentive for further development
Optical properties of self-organized wurtzite InN/GaN quantum dots: A combined atomistic tight-binding and full configuration interaction calculation
In this work we investigate the electronic and optical properties of
self-assembled InN/GaN quantum dots. The one-particle states of the
low-dimensional heterostructures are provided by a tight-binding model that
fully includes the wurtzite crystal structure on an atomistic level. Optical
dipole and Coulomb matrix elements are calculated from these one-particle wave
functions and serve as an input for full configuration interaction
calculations. We present multi-exciton emission spectra and discuss in detail
how Coulomb correlations and oscillator strengths are changed by the
piezoelectric fields present in the structure. Vanishing exciton and biexciton
ground state emission for small lens-shaped dots is predicted.Comment: 3 pages, 2 figure
Parvovirus B19 infection in pediatric transplant patients
Evidence of recent parvovirus virus infection (as determined by the presence of a positive IgM antibody titer) without other identified causes of anemia was found in 5 of 26 pediatric solid-organ transplant recipients evaluated for moderate-to-severe anemia between June 1990 and July 1991. Anemia tended to be chronic (median duration of anemia at the time of diagnosis was 12 weeks) and was associated with normal red blood cell indices in the absence of reticulocytes. The median age of the children at the time of presentation with anemia due to parvovirus was 1.8 years at a median time of 8 months after transplantation. Four of the 5 children were treated with i.v. immunoglobulin because of persistance of anemia requiring blood transfusions. A response characterized by an increase in reticulocyte count and normalization of hemoglobin was seen in each of these patients 2-4 weeks after treatment. The remaining patient experienced a spontaneous recovery from her anemia. Parvovirus infection should be included in the differential diagnosis of solid-organ transplant recipients presenting with severe anemia associated with low or absent reticulocytes
A rolling-horizon quadratic-programming approach to the signal control problem in large-scale congested urban road networks
The paper investigates the efficiency of a recently developed signal control methodology, which offers a computationally feasible technique for real-time network-wide signal control in large-scale urban traffic networks and is applicable also under congested traffic conditions. In this methodology, the traffic flow process is modeled by use of the store-and-forward modeling paradigm, and the problem of network-wide signal control (including all constraints) is formulated as a quadratic-programming problem that aims at minimizing and balancing the link queues so as to minimize the risk of queue spillback. For the application of the proposed methodology in real time, the corresponding optimization algorithm is embedded in a rolling-horizon (model-predictive) control scheme. The control strategy’s efficiency and real-time feasibility is demonstrated and compared with the Linear-Quadratic approach taken by the signal control strategy TUC (Traffic-responsive Urban Control) as well as with optimized fixed-control settings via their simulation-based application to the road network of the city centre of Chania, Greece, under a number of different demand scenarios. The comparative evaluation is based on various criteria and tools including the recently proposed fundamental diagram for urban network traffic
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