3,159 research outputs found
Loops, Cutoffs and Anomalous Gauge Boson Couplings
We discuss several issues regarding analyses which use loop calculations to
put constraints on anomalous trilinear gauge boson couplings (TGC's). Many such
analyses give far too stringent bounds. This is independent of questions of
gauge invariance, contrary to the recent claims of de Rujula et. al., since the
lagrangians used in these calculations ARE gauge invariant, but the SU(2)_L X
U(1)_Y symmetry is nonlinearly realized. The real source of the problem is the
incorrect use of cutoffs -- the cutoff dependence of a loop integral does not
necessarily reflect the true dependence on the heavy physics scale M. If done
carefully, one finds that the constraints on anomalous TGC's are much weaker.
We also compare effective lagrangians in which SU(2)_L X U(1)_Y is realized
linearly and nonlinearly, and discuss the role of custodial SU(2) in each
formulation.Comment: talk presented at the XXVI International Conference on High Energy
Physics, Dallas, USA, August 1992, plain TeX, 12 pages, 3 figures (not
included), UdeM-LPN-TH-105, McGill-92/3
Transient growth in stable collisionless plasma
The first kinetic study of transient growth for a collisionless homogeneous
Maxwellian plasma in a uniform magnetic field is presented. A system which is
linearly stable may display transient growth if the linear operator describing
its evolution is non-normal, so that its eigenvectors are non-orthogonal. In
order to include plasma kinetic effects a Landau fluid model is employed. The
linear operator of the model is shown to be non-normal and the results suggest
that the nonnormality of a collisionless plasma is intrinsically related to its
kinetic nature, with the transient growth being more accentuated for smaller
scales and higher plasma beta. The results based on linear spectral theory have
been confirmed with nonlinear simulations.Comment: accepted as a Letter in Physics of Plasma
Jobs, Workers and Changes in Earnings Dispersion
The 'fractal' nature of the rise in earnings dispersion is one of its key features and remains a puzzle. In this paper, we offer a new perspective on the causes of changes in earnings dispersion, focusing on the role of labour reallocation. Once we drop the assumption that all firms pay a given worker the same, the allocation of workers to firms matters for the dispersion of earnings. This perspective highlights two new factors that can affect the dispersion of earnings: rates of job and worker reallocation, and the nature of the process allocating workers to jobs. We set out a framework capturing this idea and quantify the impact of reallocation on earnings dispersion, using a dataset that comprises almost the universe of workers and the universe of employers in Maryland. We show that these factors have potentially large effects in general on earnings dispersion. In the case of Maryland over the period 1985-1994, the changing allocation of workers to jobs played a significant role in explaining movements in the dispersion of earnings.Earnings inequality, labour reallocation, matched worker and firm panels
The chemistry of ultrasonic degradation of organic compounds
The destruction of toxic organic molecules using advanced oxidation processes (AOPs) is a potent tool for pollution control and environmental protection. Ultrasound is a convenient and effective method of generating hydroxyl radicals which is the key oxidant in AOPs. This review describes the use of ultrasound and associated chemical reactions, with and without additives, as a powerful means of remediating water contaminated with organic pollutants. After a brief introduction to ultrasound and sonochemistry, their application for the oxidation of polycyclic aromatic hydrocarbons, phenol and substituted phenols is considered. Next is the decomposition of chlorinated phenols, and other chlorinated organics, then removal of recalcitrant smaller organic molecules. A discussion follows of recent work that has investigated the effects of initial concentration of substrates; the use of different ultrasonic frequencies; the inclusion of oxidising species, inorganic particles, or salts and their contribution to enhanced degradation. Finally, brief comments are made on the status of ultrasound as an AOP treatment
Concert recording 2018-03-08
[Track 1]. Mafuá / Armando Neves -- [Track 2]. Suite SudAmericana. Preludio Choro/Brazil Takirari/Bolivia Tonada/Chile Gato y Malambo/Argentina / Hector Ayala -- [Track 3]. Four pieces. Jorge do Fusa Dua contas [Track 4]. Aquelles Velhos Tempos Lamentos do Morro / Garoto Anibal Augusto Sardinha -- [Track 5]. Three Cuban pieces. Son del barrio Drume negrita La comprasa / Eduardo Martin Emilio Grenet / Ernesto Lecuona -- [Track 6]. Two pieces. Preludio Choro/Brazil / Yamandú Costa
Engaging with a history of counselling, spirituality and faith in Scotland: a readers' theatre script
This paper presents an abbreviated version of a verbatim script developed from oral history interviews with individuals key to the development of counselling and psychotherapy in Scotland from 1960 to 2000. Earlier versions were used in workshops with counsellors and pastoral care practitioners to share counter-narratives of counselling and to provide opportunities for conversations about historical and contemporary relationships between faith, spirituality, counselling and psychotherapy. By presenting intertwined histories in a readers' theatre script, the narrative nature of lives lived in context was respected. By bringing oral histories into virtual dialogue with each other and with contemporary practitioners, whether through workshops or through publications, the interplay between individual, institutional and societal narratives remains visible and open to change
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