11,096 research outputs found
An analytic model of plasma-neutral coupling in the heliosphere plasma
We have developed an analytic model to describe coupling of plasma and
neutral fluids in the partially ionized heliosphere plasma medium. The sources
employed in our analytic model are based on a -distribution as opposed
to the Maxwellian distribution function. Our model uses the
-distribution to analytically model the energetic neutral atoms that
result in the heliosphere partially ionized plasma from charge exchange with
the protons and subsequently produce a long tail which is otherwise not
describable by the Maxwellian distribution. We present our analytic formulation
and describe major differences in the sources emerging from these two distinct
distributions.Comment: This paper has been accepted in Journal of Plasma Physics. It is in
pres
Nonlinear Phenomena of Ultracold Atomic Gases in Optical Lattices: Emergence of Novel Features in Extended States
The system of a cold atomic gas in an optical lattice is governed by two
factors: nonlinearity originating from the interparticle interaction, and the
periodicity of the system set by the lattice. The high level of controllability
associated with such an arrangement allows for the study of the competition and
interplay between these two, and gives rise to a whole range of interesting and
rich nonlinear effects. This review covers the basic idea and overview of such
nonlinear phenomena, especially those corresponding to extended states. This
includes "swallowtail" loop structures of the energy band, Bloch states with
multiple periodicity, and those in "nonlinear lattices", i.e., systems with the
nonlinear interaction term itself being a periodic function in space.Comment: 39 pages, 21 figures; review article to be published in a Special
Issue of Entropy on "Non-Linear Lattice
Power Corrections to Fragmentation Functions in Non-Singlet Deep Inelastic Scattering
We investigate the power-suppressed corrections to the fragmentation
functions of the current jet in non-singlet deep inelastic lepton-hadron
scattering. The current jet is defined by selecting final-state particles in
the current hemisphere in the Breit frame of reference. Our method is based on
an analysis of one-loop Feynman graphs containing a massive gluon, which is
equivalent to the evaluation of leading infrared renormalon contributions. We
find that the leading corrections are proportional to , as in
annihilation, but their functional forms are different. We give quantitative
estimates based on the hypothesis of universal low-energy behaviour of the
strong coupling.Comment: 14 pages, 4 figures, LaTeX2e, uses JHEP.cls (included) and epsfi
Small manufacturing plants, pollution, and poverty : new evidence from Brazil and Mexico
The authors use new data from Brazil and Mexico to analyze relationships linking economic development, the size distribution of manufacturing plants, and exposure to industrial pollution. For lack of data, prior work in this field has been limited largely to water pollution and medium-size plants. This study examines air pollution and encompasses small plants (with 1 to 20 employees) as well as medium-size and large plants. Four main questions are addressed (with answers from plant-level data): a) Are small plants more pollution-intensive than large facilities? Clearly, yes. b) Are there proportionately more small plants in low-income regions? The answer is yes, in thousands of Brazilian municipalities. Small plants dominate poor regions and are a relatively low source of employment in high-income areas. c) Is industry more pollution-intensive in low-income regions? In Brazil, yes. For each municipality, the authors estimate the share of the six most pollution-intensive ("dirty") sectors in total industrial activity. They find that the dirty-sector share declines continuously with increases in municipality income per capita. d) Do poor areas suffer more than wealthy areas from industrial air pollution? Paradoxically, no. The risk of mortality from industrial air pollution is much higher in the top two income deciles among Brazil's municipalities and the great majority of projected deaths is attributable to emissions from large plants.The scale of large-plant emissions dominates all other factors. Lower-income areas suffer much less from industrial air pollution in Brazil, despite the greater emissions-intensity of smaller plants and the prevalence of smaller plants in lower income areas.Water and Industry,Environmental Economics&Policies,Sanitation and Sewerage,Public Health Promotion,Health Monitoring&Evaluation,Environmental Economics&Policies,Water and Industry,Health Monitoring&Evaluation,Sanitation and Sewerage,TF030632-DANISH CTF - FY05 (DAC PART COUNTRIES GNP PER CAPITA BELOW USD 2,500/AL
Measuring Visual Complexity of Cluster-Based Visualizations
Handling visual complexity is a challenging problem in visualization owing to
the subjectiveness of its definition and the difficulty in devising
generalizable quantitative metrics. In this paper we address this challenge by
measuring the visual complexity of two common forms of cluster-based
visualizations: scatter plots and parallel coordinatess. We conceptualize
visual complexity as a form of visual uncertainty, which is a measure of the
degree of difficulty for humans to interpret a visual representation correctly.
We propose an algorithm for estimating visual complexity for the aforementioned
visualizations using Allen's interval algebra. We first establish a set of
primitive 2-cluster cases in scatter plots and another set for parallel
coordinatess based on symmetric isomorphism. We confirm that both are the
minimal sets and verify the correctness of their members computationally. We
score the uncertainty of each primitive case based on its topological
properties, including the existence of overlapping regions, splitting regions
and meeting points or edges. We compare a few optional scoring schemes against
a set of subjective scores by humans, and identify the one that is the most
consistent with the subjective scores. Finally, we extend the 2-cluster measure
to k-cluster measure as a general purpose estimator of visual complexity for
these two forms of cluster-based visualization
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