3,364 research outputs found
Volume 13. Article 3. Hydrographic and biological studies of Block Island Sound.
https://elischolar.library.yale.edu/bulletin_yale_bingham_oceanographic_collection/1150/thumbnail.jp
Kinematic classifications of local interacting galaxies: implications for the merger/disk classifications at high-z
The classification of galaxy mergers and isolated disks is key for
understanding the relative importance of galaxy interactions and secular
evolution during the assembly of galaxies. The kinematic properties of galaxies
as traced by emission lines have been used to suggest the existence of a
significant population of high-z star-forming galaxies consistent with isolated
rotating disks. However, recent studies have cautioned that post-coalescence
mergers may also display disk-like kinematics. To further investigate the
robustness of merger/disk classifications based on kinematic properties, we
carry out a systematic classification of 24 local (U)LIRGs spanning a range of
galaxy morphologies: from isolated spiral galaxies, ongoing interacting
systems, to fully merged remnants. We artificially redshift the WiFeS
observations of these local (U)LIRGs to z=1.5 to make a realistic comparison
with observations at high-z, and also to ensure that all galaxies have the same
spatial sampling of ~900 pc. Using both kinemetry-based and visual
classifications, we find that the reliability of kinematic classification shows
a strong trend with the interaction stage of galaxies. Mergers with two nuclei
and tidal tails have the most distinct kinematic properties compared to
isolated disks, whereas a significant population of the interacting disks and
merger remnants are indistinguishable from isolated disks. The high fraction of
late-stage mergers showing disk-like kinematics reflects the complexity of the
dynamics during galaxy interactions. However, the exact fractions of
misidentified disks and mergers depend on the definition of kinematic
asymmetries and the classification threshold when using kinemetry-based
classifications. Our results suggest that additional indicators such as
morphologies traced by stars or molecular gas are required to further constrain
the merger/disk classifications at high-z.Comment: 16 pages, 5 figures, ApJ accepte
The West Falmouth oil spill : persistence of the pollution eight months after the accident
A spill of 650,000-700,000 liters of #2 fuel oil has contaminated the coastal areas of Buzzards Bay, Mass. The present report summarizes the results of our continuing
chemical and biological study which were available at the end of May 1970, more than eight months after the accident.
The effects of environmental exposure on the composition of the oil are discussed; many analytical parameters are sufficiently stable to permit continued correlation of
the oil remaining in sediments and organisms with the fuel oil involved in the spill.
Oil from the spill is still present in the sediments, inshore and offshore and in the shellfish. A further spread of the pollution to more distant offshore regions has occurred during midwinter; as a result, the pollution now covers a much larger area than immediately after the accident. The first stages of biological (presumably bacterial) degradation of the oil are now evident especially in the least polluted regions; however, it has depleted predominantely the straight and branched chain alkanes. The more toxic aromatic hydrocarbons are resistant; as a result, the toxicity of the oil has not been diminished.
Where oil can be detected in the sediments there has been a kill of animals; in the most polluted areas the kill has been almost total. Shellfish that survived the accident have taken up the fuel oil. The 1970 crop of shellfish is as heavily polluted as was last year’s crop. Oysters transplanted to unpolluted water for as long as 6 months retained the oil without change in composition or concentration.Submitted to the Office of Naval Research under Contract ONR N00014-66-C0241; NR 083-0043 and partially supported by the Federal Water Quality Act Grant 18050-EBN3 and with the National Science Foundation Grant GA-1625
Anatomy of an oil spill : long-term effects from the grounding of the barge Florida off West Falmouth, Massachusetts
Author Posting. © Yale University, 1980. This article is posted here by permission of Yale University for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 38 (1980): 265-380.To determine carefully the effects on the marine and estuarine benthos of Number 2 fuel oil
spilled by the barge FLORIDA off West Falmouth, Massachusetts, we sampled for many
months along an onshore-offshore gradient of pollution, and less intensively at unoiled sites.
Analyses of hydrocarbons established that pollution was greatest and most persistent in the
intertidal and subtidal zones of Wild Harbor River, less severe in degree and duration at stations farthest from shore. A variety of concurrent analyses showed that disturbance of the fauna
was most severe and longest lasting at the most heavily oiled sites, and least severe but perceptible
at lightly oiled stations. Patterns of disturbance were not related to granulometry of
the sediments. Plants, ctustaceans, fish, and birds suffered both high mortality immediately
after the spill, and physiological and behavioral abnormalities directly related to high concentrations
of the fuel oil. Five years after the spill its effects on the biota were still detectable, and
partly degraded #2 fuel oil was still present in the sediments in Wild Harbor River and estuary.Our study was partially supported by the Federal Water Pollution Control
Contract 15080, the Environmental Protection Agency Grant No. R80100102 and Massachusetts
Division of Water Pollution Control primarily during the initial three years and by
the Woods Hole Oceanographic Institution at specific key periods
Volume 15. Article 1. Oceanography of Long Island Sound, 1952–1954.
https://elischolar.library.yale.edu/bulletin_yale_bingham_oceanographic_collection/1154/thumbnail.jp
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Pulsed, Inductively Generated, Streaming Plasma Ion Source for Heavy Ion Fusion Linacs
This report describes a compact, high current density, pulsed ion source, based on electrodeless, inductively driven gas breakdown, developed to meet the requirements on normalized emittance, current density, uniformity and pulse duration for an ion injector in a heavy-ion fusion driver. The plasma source produces >10 μs pulse of Argon plasma with ion current densities >100 mA/cm2 at 30 cm from the source and with strongly axially directed ion energy of about 80 eV, and sub-eV transverse temperature. The source has good reproducibility and spatial uniformity. Control of the current density during the pulse has been demonstrated with a novel modulator coil method which allows attenuation of the ion current density without significantly affecting the beam quality. This project was carried out in two phases. Phase 1 used source configurations adapted from light ion sources to demonstrate the feasibility of the concept. In Phase 2 the performance of the source was enhanced and quantified in greater detail, a modulator for controlling the pulse shape was developed, and experiments were conducted with the ions accelerated to >40 kV
Compendium of Current Single Event Effects Results for Candidate Spacecraft Electronics for NASA
Sensitivity of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects is presented. Devices tested include digital, linear, and hybrid devices
Merger Signatures in the Dynamics of Star-forming Gas
The recent advent of integral field spectrographs and millimeter interferometers has revealed the internal dynamics of many hundreds of star-forming galaxies. Spatially resolved kinematics have been used to determine the dynamical status of star-forming galaxies with ambiguous morphologies, and constrain the importance of galaxy interactions during the assembly of galaxies. However, measuring the importance of interactions or galaxy merger rates requires knowledge of the systematics in kinematic diagnostics and the visible time with merger indicators. We analyze the dynamics of star-forming gas in a set of binary merger hydrodynamic simulations with stellar mass ratios of 1:1 and 1:4. We find that the evolution of kinematic asymmetries traced by star-forming gas mirrors morphological asymmetries derived from mock optical images, in which both merger indicators show the largest deviation from isolated disks during strong interaction phases. Based on a series of simulations with various initial disk orientations, orbital parameters, gas fractions, and mass ratios, we find that the merger signatures are visible for ~0.2–0.4 Gyr with kinematic merger indicators but can be approximately twice as long for equal-mass mergers of massive gas-rich disk galaxies designed to be analogs of z ~ 2–3 submillimeter galaxies. Merger signatures are most apparent after the second passage and before the black holes coalescence, but in some cases they persist up to several hundred Myr after coalescence. About 20%–60% of the simulated galaxies are not identified as mergers during the strong interaction phase, implying that galaxies undergoing violent merging process do not necessarily exhibit highly asymmetric kinematics in their star-forming gas. The lack of identifiable merger signatures in this population can lead to an underestimation of merger abundances in star-forming galaxies, and including them in samples of star-forming disks may bias the measurements of disk properties such as intrinsic velocity dispersion
Implementing Disruptive Technological Change in UK Healthcare: Exploring the Development of a Smart Phone App for Remote Patient Monitoring as a Boundary Object
Developing and applying technological innovations in healthcare is a complex and uncertain process, due to the many surprising and unexpected effects upon the practices, perspectives and interests of the variety of professional and managerial stakeholders involved. In this paper, we draw upon the concept of boundary object to explore processes of collaboration, knowledge transformation and learning associated with the development, use and (prospective) wider diffusion in the English healthcare system of a particular type of healthcare innovation: a smart phone app for use by rheumatoid arthritis patients. Taking into account that technological artefacts can both enable and inhibit collaboration, as well as evolve during their development, we explore the challenges of overcoming tensions between the transformative and learning capabilities of such technological artefacts and the inhibitions that these capabilities simultaneously create for change at a wider system level
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