4,896 research outputs found
Examining the mortality effects of the Irish National Smoking Ban.
Secondhand smoke causes disease and death in those exposed, with cardiovascular and respiratory problems as the most likely outcomes. The purpose of this study was to examine the mortality effects of the Irish national smoking ban of 2004
Colliding String Waves and Duality
The collision of plane waves corresponding to massless states of closed
string is considered in -dimensional space-time. The reduced tree level
effective action is known to be manifestly invariant, being the
number of transverse spatial dimensions in the collision process. We adopt a
coset space reformulation of the effective two dimensional theory and discuss
the relation of this process with classical integrable systems in two
dimensions in the presence of gravity. We show how it is possible to generate
new backgrounds for the scattering process, from known background solutions to
the equations of motion, in the coset reformulation. We present explicit
calculations for the case of four space-time dimensions as an illustrative
example.Comment: 14 page
Wind mapping in Venus' upper mesosphere with the IRAM-Plateau de Bure interferometer
The dynamics of the upper mesosphere of Venus (~85-115 km) have been
characterized as a combination of a retrograde superrotating zonal wind (RSZ)
with a subsolar-to-antisolar flow (SSAS). Numerous mm-wave single-dish
observations have been obtained and could directly measure mesospheric
line-of-sight winds by mapping Doppler-shifts on CO rotational lines, but their
limited spatial resolution makes their interpretation difficult. By using
interferometric facilities, one can obtain better resolution on Doppler-shifts
maps, allowing in particular to put firmer constraints on the respective
contributions of the SSAS and RSZ circulations to the global mesospheric wind
field. We report on interferometric observations of the CO(1-0) line obtained
with the IRAM-Plateau de Bure interferometer in November 2007 and June 2009,
that could map the upper mesosphere dynamics on the morning hemisphere with a
very good spatial resolution (3.5-5.5"). All the obtained measurements show,
with a remarkably good temporal stability, that the wind globally flows in the
(sky) East-West direction, corresponding in the observed geometry either to an
unexpected prograde zonal wind or a SSAS flow. A very localized inversion of
the wind direction, that could correspond to a RSZ wind, is also repeatedly
detected in the night hemisphere. The presence of significant meridional winds
is not evidenced. Using models with different combinations of zonal and SSAS
winds, we find that the data is best reproduced by a dominant SSAS flow with a
maximal velocity at the terminator of ~200 m/s, displaying large diurnal and
latitudinal asymmetries, combined with an equatorial RSZ wind of 70-100 m/s,
overall indicating a wind-field structure consistent with but much more complex
than the usual representation of the mesospheric dynamics.Comment: Accepted for publication in A&
Excess mortality during heat waves in Ireland
Ireland is not known for having extreme high temperatures, with values above 30C uncommon. Ireland has significant excess winter mortality compared to summer. The objective of this study is to estimate the impact of nation-wide heat waves on the total, cardiovascular and respiratory relationship, for the period 1981â2003, to determine if there are any periods of excess summer mortality
Effect of air pollution controls on black smoke and sulfur dioxide concentrations across Ireland
During the 1980s Ireland experienced severe pollution episodes, principally because of domestic coal burning. In 1990, the Irish government introduced a ban on the marketing, sale, and distribution of coal in Dublin. They extended the ban to Cork in 1995 and to ten other communities in 1998 and 2000. We previously reported declines in particulate (black smoke [BS]) and sulfur dioxide (SO2) concentrations in Dublin following the 1990 coal ban. We now explore and compare the effectiveness of these sequential bans in 1990, 1995, 1998, and 2000. Daily BS and total gaseous acidity (502) measurements were compiled between 1980 and 2004. We calculated descriptive statistics for the pre-ban (5 yr before ban) and post-ban (5 yr after ban) periods for BS and SO2 concentrations and for season-specific periods. Mean BS levels fell in all centers post-ban compared with the pre-ban period, with decreases ranging; from 4 to 35 mu g.m(-3) (-45 to -70%). These reductions were smallest in the summer and largest in the winter. These BS, reductions were sustained in all centers until the end of the study period. We observed no clear pattern in SO2 changes associated with the coal bans. The 1990, 1995, 1998, and 2000 Irish coal sale bans resulted in immediate and sustained decreases in particulate levels in centers, with the largest declines in the winter. In contrast, we did not observe consistent declines in total acidity as a measure of SO2. It may be that coal was not the major source. of SO2. Simple legislation was very effective at improving ambient air quality in Irish cities with varying populations, geography/topography, and meteorological conditions
Defining the Identity of a Human Clone
Researchers have successfully created therapeutic cloning, but how advanced will technology become before scientists start replicating the DNA of humans to create a whole human clone? The idea of human cloning has been a big controversy since 1996. In 1996, scientists made it possible to clone the first mammal, which was âDollyâ the sheep. When they finally do replicate their first human clone, will this new clone have its own personal identity or the identity of who it was replicated of? Arguments have come about whether this reproductive cloned human will have a unique new identity, or whether it will just be a mere identical âcopy.â Before scientists make reproductive human clones, these questions need to be addressed.
My research will attempt to define the essential nature of a human clone, by examining whether this âcopyâ represents an individual human, or a new species. The project will ultimately define what a clone is, but specifically defining what it means to be a human clone. Will the clone have the same identity or will it be unique? I will propose my own ideaâs on why I believe a human clone will have its own unique qualities. In order to answer my research question, I plan to discuss what makes one considered a human; physically and mentally. I will use literature such as Science Fiction & Philosophy, by Susan Schneider, and films such as The Island (2005), to gain the knowledge in order to gather the research to better answer these questions
Decomposition of Cr(OH)â to form active CrâCâ
This study was concerned with the sinterability of CrâCâ powders produced by the calcination of a Cr(OH)â gel. The decomposition of the gel was investigated by thermogravimetric analysis, X-ray analysis and microscopic examination. Comparison was made between the size of crystallites as determined by X-ray line broadening and the size of aggregated particles as determined by independent means. These lineal measurements were compared to surface area measurements on the calcined powders. The degree of sinterability was judged from the density measurements on CrâCâ pellets fired under air, oxygen and nitrogen atmospheres. Energies of activation of 25 and 20 kilocalories per mole were found for the decomposition process and the crystallite growth process, respectively. The decomposition process can be described as a unimolecular mechanism obeying first-order reaction kinetics. The calcined powders were found to be composed of small hexagonal platelets arranged in loosely packed aggregates. The optimum calcination temperature was determined to be approximately 500â°C. A maximum sintered density of 4.35 grams per cubic centimeter illustrated the effectiveness of a nitrogen sintering atmosphere --Abstract, page ii-iii
A "partitioned leaping" approach for multiscale modeling of chemical reaction dynamics
We present a novel multiscale simulation approach for modeling stochasticity
in chemical reaction networks. The approach seamlessly integrates
exact-stochastic and "leaping" methodologies into a single "partitioned
leaping" algorithmic framework. The technique correctly accounts for stochastic
noise at significantly reduced computational cost, requires the definition of
only three model-independent parameters and is particularly well-suited for
simulating systems containing widely disparate species populations. We present
the theoretical foundations of partitioned leaping, discuss various options for
its practical implementation and demonstrate the utility of the method via
illustrative examples.Comment: v4: 12 pages, 5 figures, final accepted version. Error found and
fixed in Appendi
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Topology Driven Improvement of FDC Build Parameters
The likeliest failure origin for advanced ceramics parts, prepared by fused
deposition, is a void from improper fill. Adequate filling of each cross-section is dependent upon the deposition toolpath. Cross-sectional spaces are conventionally
filled with pre-defined parameters. We propose that adaptive build parameters will
control variations in geometry and property of a part. Voids, overfilling,
incomplete bonding and excess traversing can be suppressed by adjusting the fill
parameters for cross-sectional areas. Improved build parameters and toolpath
allows for faster build time and components ofj full density. Some implementations
are discussed and presented.Mechanical Engineerin
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