3,476 research outputs found
Newly discovered halos and outer features around southern planetary nebulae
We have used the SuperCOSMOS H-alpha Survey to look for faint outer
structures such as halos, ansae and jets around known planetary nebulae across
4000 square degrees of the southern Milky Way. Our search will contribute to a
more accurate census of these features in the Galactic PN population. Candidate
common-envelope PNe have also been identified on the basis of their
microstructures. We also intend to determine more reliable distances for these
PNe, which should allow a much better statistical basis for the post-AGB total
mass budget. Our survey offers fresh scope to address this important issue.Comment: 2 pages, 1 figure. To be published in Planetary Nebulae: an Eye to
the Future, Proceedings of IAU Symposium 283, held in Puerto de la Cruz,
Tenerife, Spain, July 25-29 201
Interpreting the Atmospheric Neutrino Anomaly
We suggest that the atmospheric neutrino anomaly observed in the
Super-Kamiokande (and other) experiments results from the combined effects of
muon-neutrino to tau-neutrino oscillations with a Delta m^2 value of
approximately 0.4 eV^2 and oscillations between muon neutrinos and electron
neutrinos (and vice-versa) with 0.0001 < Delta m^2 < 0.001 eV^2. With an
appropriate choice of a three-neutrino mixing matrix, such a hypothesis is
consistent with essentially all neutrino observations.Comment: 12 pages, 2 eps figures, Latex2e, elsart style, submitted to Physics
Letters B --REV2-- Updated figure 1 and added figure 2: Super-K single R dat
Revisiting Joan Acker's work with the support of Joan Acker
This article is a personal tribute to working with Joan Acker. I worked with Joan in 2012, helping to edit her own thoughts and reflection on how other academics evaluate and used her own theorizing, specifically her seminal work on the gender substructure and inequality regimes. However, while this article is a tribute to Joan, her work and her thinking; it is also a personal thank you to someone I will miss for her generosity and also her activism in challenging inequalities in organizations and beyond. She continues to inspire me and hopefully others to challenge for social justice. In her 80s, Joan remained committed to addressing inequalities in social relations and how these were experienced within a dynamic social and work environment. During our collaboration, she called upon academics to put theory into practice to help address visible and invisible inequalities in organizational processes. This article is inspired by that experience and it will reveal Joan's views about her own, and other academics, theorizing of her two key concepts: the gender substructure of organizations and inequality regimes in organizations and the overlap with intersectionality. This article will offer a unique opportunity to gain insight into Joan's thinking as an academic sociologist as well as a feminist activist thereby uniting Joan as a person with her concepts
Alien Registration- Acker, Freeman S. (Bar Harbor, Hancock County)
https://digitalmaine.com/alien_docs/19897/thumbnail.jp
Spatial Analysis of Environmental Factors Affecting Endangered and Invasive Fish Species on the Belize Barrier Reef
The second largest reef in the world is experiencing a dramatic change in its environment with continued development and an influx in tourism having a direct impact on the physical and ecological balance of the reef. The introduction of hazardous materials and practices have contributed to reef degradation through excess sedimentation, overfishing, and increased shipping and have the ability to influence some of the reef’s most endangered inhabitants. A spatial examination using multiple variables impacting changes in certain populations of endangered and invasive fish species are studied, incorporating integrated species abundance and sighting data as well as potential environmental threats to aim to understand the trends and correlations between Belize’s recent spike in development, and the implications on its barrier reef
Generalizing about trade show effectiveness: a cross-national comparison.
Trade shows are a multi-billion dollar business in the US and the UK, but little is known about the determinants of trade show effectiveness. In this paper, we build a model that explains differences in trade show effectiveness across industries, across companies and across two countries. We focus on the differences in trade show effectiveness measured in a similar way across similar samples of 171 US and 135 UK firm-show experiences between 1980 and 1991. While the similarities outweigh the differences, we find evidence that trade shows are viewed differently by exhibitors and attendees in these two countries. We are able to make substantial generalizations about the effect of various show selection (go-not go) variables (booth size, personnel, etc.) on observed performance. We discuss the implications of our research for developing benchmarks for trade show performance and for better global management of the business marketing communications mix.Effectiveness; Trade;
MSW mediated neutrino decay and the solar neutrino problem
We investigate the solar neutrino problem assuming simultaneous presence of
MSW transitions in the sun and neutrino decay on the way from sun to earth. We
do a global -analysis of the data on total rates in Cl, Ga and
Superkamiokande (SK) experiments and the SK day-night spectrum data and
determine the changes in the allowed region in the \dm - \tan^2\theta plane
in presence of decay. We also discuss the implications for unstable neutrinos
in the SNO experiment.Comment: Final version to appear in Phys. Rev.
Constraints on decay plus oscillation solutions of the solar neutrino problem
We examine the constraints on non-radiative decay of neutrinos from the
observations of solar neutrino experiments. The standard oscillation hypothesis
among three neutrinos solves the solar and atmospheric neutrino problems. Decay
of a massive neutrino mixed with the electron neutrino results in the depletion
of the solar neutrino flux. We introduce neutrino decay in the oscillation
hypothesis and demand that decay does not spoil the successful explanation of
solar and atmospheric observations. We obtain a lower bound on the ratio of the
lifetime over the mass of , (\tau_2/m_2) > 22.7 (\srm/\MeV) for the
MSW solution of the solar neutrino problem and (\tau_2/m_2) > 27.8
(\srm/\MeV) for the VO solution (at 99% C.L.).Comment: 8 pages latex file with 4 figure
The dynamics of planetary nebulae in the Galaxy: evidence for a third integral
We present a dynamical analysis of 673 galactic Planetary Nebulae, using a
two-integral axisymmetric model with a Kuzmin-Kutuzov St\"{a}ckel potential.
The method fits the kinematics to the projected moments of a distribution
function, by means of Quadratic Programming. The 2.2 m COBE brightness map
has been used after correction for the interstellar extinction as a projected
star counts map in the modeling, because it constitutes a galactic distribution
view of evolved red populations which are considered to be the progenitors of
PNe. The model we have obtained provides a 2-integral distribution function for
the COBE 2.2 m map, and thus {\it a fortiori} a deprojection of it, which
allows moreover the identification of all the major Galactic components. We
derive the density laws for them. The projected velocity dispersions are not
well fitted though, especially in the disk, which points at the likely presence
of a third integral. If this result can be confirmed by additional data, this
would mean that for the first time the presence and importance of a third
integral on a global scale is demonstrated.Comment: 9 pages, uuencoded gzipped postscript file, 9 figures include
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