856 research outputs found
Accidental Releases of Sour Gas From Wells and Collection Pipelines in the Overthrust Belt: Calculating and Assessing Potential Health and Environmental Risks
Parts of the Overthrust Belt of western Wyoming and adjoining areas in Utah and Idaho contain geologic formations with significant accumulations of oil and natural gas. Some of these formations, though, yield gas that is contaminated with toxic hydrogen sulfide. As a consequence, the development of these so-called sour-gas reservoirs requires special safety procedures and technologies in order to prevent accidental releases of gas to the atmosphere that could cause adverse occupational and public health effects. To improve the analysis and assessment of wells and collection pipelines completed on lands leased from the Federal Government, the Minerals Management Service, Onshore Operations, now part of the Bureau of Land Management (BLM), asked Lawrence Livermore National Laboratory to conduct a study to test methods to the analysis of the potential risks associated with the development of sour-gas resources located near Evanston, Wyoming. The process of assessing the health risks of a potential sour-gas release involves estimation of the emission rate of hydrogen sulfide, specification of how the gas is released (e.g., vertically into the atmosphere or horizontally), prediction of downwind concentrations of the gas, analysis of the potential health effects, and finally, review of safety methods required to minimize the potential health risks. The first part of the report includes an analysis of data on the health effects of hydrogen sulfide to determine the nature of its dose-response relationship. Following that review is a study of the different methods of quantifying the emission rate of gas from wells and pipelines. Data on the frequency of accidental releases from those facilities are also analyzed. To assess the health risks of an accidental release from a well under BLM supervision located near Evanston, we collected meteorological data for 1 yr from four stations in that area. Our analysis of a worst-case release scenario (i.e., a gas plume that is near the surface) using those data indicates that the greatest risks of incurring an acute health effect (e.g., unconsciousness, respiratory arrest, pulmonary edema, or death) are located in the northwest sector downwind from the well because of the occurrence of stable atmospheric conditions along with slow winds from the southeast. The risks of an acute health effect in that northwest sector over the 20-yr operation of the well were on the order of 10 -4 to 10 -5 -- similar to the risk of accidental death caused by a natural disaster over the same period
Threshold meson production and cosmic ray transport
An interesting accident of nature is that the peak of the cosmic ray
spectrum, for both protons and heavier nuclei, occurs near the pion production
threshold. The Boltzmann transport equation contains a term which is the cosmic
ray flux multiplied by the cross section. Therefore when considering pion and
kaon production from proton-proton reactions, small cross sections at low
energy can be as important as larger cross sections at higher energy. This is
also true for subthreshold kaon production in nuclear collisions, but not for
subthreshold pion production.Comment: 9 pages, 1 figur
Geographical distribution of Gyrodactylus salaris Malmberg, 1957 (Monogenea, Gyrodactylidae)
Background Gyrodactylus salaris Malmberg, 1957 is an OIE (Office International des Epizooties)-listed parasitic pathogen and had until the current study been reported from 19 countries across Europe, although many of these records require confirmation. The last comprehensive evaluation regarding the distribution of G. salaris, however, was made in 2007, although some of the states identified as being G. salaris-positive were ascribed this status based on misidentifications, on partial data resulting from either morphological or molecular tests, or from records that have not been revisited since their early reporting. It is thus important to go through the reports on G. salaris to obtain a status for each country. Methods To provide a revised update of the G. salaris distribution, a literature review was necessary. This literature, however, was not always readily accessible and, in certain cases, the article only made superficial reference to the parasite without providing details or data to support the identification. In most cases, the original specimens were not deposited in a national collection. Additional Gyrodactylus material for the current study was obtained from selected salmonid populations with the aim to contribute to current understanding regarding the distribution of G. salaris. Additional parasite material collected for this study was processed following standard procedures for species identification in Gyrodactylus [1]. Results From the work conducted in the current study, G. salaris is reported from a further three regions in Italy, alongside three other species, and appears to occur extensively throughout central Italy without causing significant mortalities to its rainbow trout, Oncorhynchus mykiss (Walbaum), host. The analysis of archive material from G. salaris-positive farms would suggest that G. salaris has been in this country since at least 2000. Material obtained from rainbow trout from Finland and Germany are confirmed as G. salaris, supporting existing data for these countries. No specimens of G. salaris, however, were found in the additional Gyrodactylus material obtained from rainbow trout reared in Portugal and Spain. A morphologically similar species, Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel et Vigneulle, 1999, however, was found. Conclusions Following the present review, Gyrodactylus salaris is reported from 23 out of 50 recognised states throughout Europe; only records from 14 of these states have been confirmed by either morphology and/or by an appropriate molecular test and are considered valid, while only nine of these records have been confirmed by a combination of both methods
Attributing scientific and technical progress: the case of holography
Holography, the three-dimensional imaging technology, was portrayed widely as a paradigm
of progress during its decade of explosive expansion 1964–73, and during its subsequent
consolidation for commercial and artistic uses up to the mid 1980s. An unusually
seductive and prolific subject, holography successively spawned scientific insights, putative
applications and new constituencies of practitioners and consumers. Waves of forecasts,
associated with different sponsors and user communities, cast holography as a field on the
verge of success—but with the dimensions of success repeatedly refashioned. This retargeting
of the subject represented a degree of cynical marketeering, but was underpinned by
implicit confidence in philosophical positivism and faith in technological progressivism.
Each of its communities defined success in terms of expansion, and anticipated continual
progressive increase. This paper discusses the contrasting definitions of progress in holography,
and how they were fashioned in changing contexts. Focusing equally on reputed ‘failures’ of some aspects of the subject, it explores the varied attributes by which success and failure were linked with progress by different technical communities. This important case illuminates the peculiar post-World War II environment that melded the military, commercial and popular engagement with scientific and technological subjects, and the
competing criteria by which they assessed the products of science
A fresh look at instrumentation - an introduction
The theme of "instrumentation between science, state and industry" does not square well with the venerable discourse which opposes "science" and "technology" in social studies of science. In this discourse, "technology" stands for the contrary of "science"; it represents the practical uses of science in society at large and is understood as separate from the somehow autonomous sphere of "science" (Layton 1971a). This vocabulary, widespread as it may be, is not very useful for our purposes, and, for that matter, for any inquiry into the role of instruments. Technology, in the sense of technical instruments and the knowledge systems that go with them, pervades all societal systems. There are technologies of science, of industry, of state, and so forth, and it would be ill-advised to assume that, in the end, they all flow out of "science." But even if the crude opposition of science and technology has little analytic value, the dual problem remains: how to effectively conceive the dynamic relationship between scientific spheres and other societal spheres, and how to conceive the role that technological matters play in this relationship
The Spectroscopy of Plasma Evolution from Astrophysical Radiation Mission
The Spectroscopy of Plasma Evolution from Astrophysical Radiation (or the
Far-ultraviolet Imaging Spectrograph) instruments, flown aboard the STSAT-1
satellite mission, have provided the first large-area spectral mapping of the
cosmic far ultraviolet (FUV, lambda 900-1750 Ang) background. We observe
diffuse radiation from hot (10^4 to 10^6 K) and ionized plasmas, molecular
hydrogen, and dust scattered starlight. These data provide for the
unprecedented detection and discovery of spectral emission from a variety of
interstellar environments, including the general medium, molecular clouds,
supernova remnants, and super-bubbles. We describe the mission and its data,
present an overview of the diffuse FUV sky's appearance and spectrum, and
introduce the scientific findings detailed later in this volume
The SPEAR Instrument and On-Orbit Performance
The SPEAR (or 'FIMS') instrumentation has been used to conduct the first
large-scale spectral mapping of diffuse cosmic far ultraviolet (FUV, 900-1750
AA) emission, including important diagnostics of interstellar hot (10^4 K -
10^6 K) and photoionized plasmas, H_2, and dust scattered starlight. The
instrumentation's performance has allowed for the unprecedented detection of
astrophysical diffuse far UV emission lines. A spectral resolution of 550 and
an imaging resolution of 5' is achieved on-orbit in the Short (900 - 1175 AA)
and Long (1335 - 1750 AA) bandpass channels within their respective 7.4 deg x
4.3' and 4.0 deg x 4.6' fields of view. We describe the SPEAR imaging
spectrographs, their performance, and the nature and handling of their data
Sociological and Communication-Theoretical Perspectives on the Commercialization of the Sciences
Both self-organization and organization are important for the further
development of the sciences: the two dynamics condition and enable each other.
Commercial and public considerations can interact and "interpenetrate" in
historical organization; different codes of communication are then
"recombined." However, self-organization in the symbolically generalized codes
of communication can be expected to operate at the global level. The Triple
Helix model allows for both a neo-institutional appreciation in terms of
historical networks of university-industry-government relations and a
neo-evolutionary interpretation in terms of three functions: (i) novelty
production, (i) wealth generation, and (iii) political control. Using this
model, one can appreciate both subdynamics. The mutual information in three
dimensions enables us to measure the trade-off between organization and
self-organization as a possible synergy. The question of optimization between
commercial and public interests in the different sciences can thus be made
empirical.Comment: Science & Education (forthcoming
- …