10,280 research outputs found
Review of: Elizabeth M. Whelan, Toxic Terror: The Truth Behind the Cancer Scares
Review of: Elizabeth M. Whelan, Toxic Terror: The Truth Behind the Cancer Scares (Prometheus Books 1993). Acknowledgements, appendix, figures, foreword by Norman F. Borlaug, index, notes tables. LC 92-34154; ISBN 0-87975-788-4. [476 pp. Cloth $26.95. 59 John Glenn Drive, Buffalo NY 14228-2197.
Properties of Turbulence in the Very Local Interstellar Clouds
We have investigated the degree to which turbulence in the Very Local
Interstellar Clouds resembles the highly-studied turbulence in the solar corona
and the solar wind. The turbulence diagnostics for the Local Clouds are the
absorption line widths measured along 32 lines of sight to nearby stars,
yielding measurements for 53 absorption components (Redfield and Linsky 2004).
We have tested whether the Local Cloud turbulence has the following properties
of turbulence in the solar corona or the solar wind: (a) velocity fluctuations
mainly perpendicular to the average magnetic field, (b) a temperature
anisotropy in the sense that the perpendicular temperature is larger than the
parallel temperature (or at least enhanced relative to expectation), and (c) an
ion temperature which is dependent on the ion Larmor radius, in the sense that
more massive ions have higher temperatures. Our analysis of the data does not
show compelling evidence for any of these properties in Local Cloud turbulence,
indicating possible differences with heliospheric plasmas. In the case of
anisotropy of velocity fluctuations, although the expected observational
signature is not seen, we cannot exclude the possibility of relatively high
degrees of anisotropy (anisotropy parameter ), if
some other process in the the Local Clouds is causing variations in the
turbulent line width from one line of sight to another. We briefly consider
possible reasons for differences between coronal and solar wind turbulence and
that in the Local Clouds.Comment: Submitted to the Astrophysical Journa
Evaluation and verification of epitaxial process sequence for silicon solar cell production
The applicability of solar cell and module processing sequences, to be used on lower cost epitaxial silicon wafers was evaluated. The extent to which the process sequences perform effectively when applied to film solar cells formed by epitaxial deposition of Si on potentially inexpensive substrates of upgraded metallurgical grade Si is examined. It is concluded that these substrates are satisfactory in their cell performance
Understanding and addressing the challenges of job loss for low-wage workers
Minimum wage ; Unemployment ; Displaced workers ; Wages
Steady state quantum mechanics of thermally relaxing systems
A theoretical description of quantum mechanical steady states is developed.
Applications for simple quantum mechanical systems described in terms of
coupled level structures yield a formulation equivalent to time independent
scattering theory. Applications to steady states of thermally relaxing systems
leads to time independent scattering theory in Liouville space that is
equivalent to the tetradic Green's function formalism. It provides however a
direct route to derive particular forms of the Liouville equation applicable in
steady state situations. The theory is applied to study the conduction
properties in the super-exchange model of a metal-molecule-metal contact weakly
coupled to the thermal environment. The energy resolved temperature dependent
transmission probability, as well as its coherent (tunneling) and incoherent
(activated) parts, are calculated using the Redfield approximation. These
components depend differently on the energy gap (or barrier), on the
temperature and on the bridge length. The coherent component is most important
at low temperatures, large energy gaps and small chain lengths. The incoherent
component dominates in the opposite limits. The integrated transmission
provides a generalization of the Landauer conduction formula for small
junctions in the presence of thermal relaxation.Comment: 31 pages, 6 figures. Chemical Physics, in pres
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