29 research outputs found
Comparison of advanced gravitational-wave detectors
We compare two advanced designs for gravitational-wave antennas in terms of
their ability to detect two possible gravitational wave sources. Spherical,
resonant mass antennas and interferometers incorporating resonant sideband
extraction (RSE) were modeled using experimentally measurable parameters. The
signal-to-noise ratio of each detector for a binary neutron star system and a
rapidly rotating stellar core were calculated. For a range of plausible
parameters we found that the advanced LIGO interferometer incorporating RSE
gave higher signal-to-noise ratios than a spherical detector resonant at the
same frequency for both sources. Spheres were found to be sensitive to these
sources at distances beyond our galaxy. Interferometers were sensitive to these
sources at far enough distances that several events per year would be expected
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Applications of electrified dust and dust devil electrodynamics to Martian atmospheric electricity
Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kVm-1 to 100 kVm-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)-MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ measurements
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Effective management of regulator RI/FS comments
This paper describes a successful strategy that facilitates regulatory approval of CERCLA documents required by compliance agreement and CERCLA, based on the experience of Operable Unit 1, Waste Storage Area, of the Fernald Environmental Management Project (FEMP). This strategy, which has become the site standard at the FEMP, was instrumental in obtaining regulator approval of the OU1 RI and FS, and early approval of the Record of Decision during a very tight compliance agreement-driven schedule. This strategy can be applied at any DOE Superfund site, especially where there is need to recover lost schedule, an incentive to meet milestones early, a need to improve the relationship between the DOE and the regulators, or where the regulatory agencies have historically provided a large volume of comments on CERCLA documents. The strategy focuses on early identification and resolution of issues relating to draft RI/FS documents, as raised in regulatory agency review comments. This pro-active strategy has the potential for schedule and cost savings, as well as for improved communication between DOE and the regulators. The strategy includes preparation of a separate comment response document, integration of comment responses with RI/FS documents, development of a database of agency comments and their resolution, and sharing lessons learned with preparers of subsequent RI/FS documents. The paper provides background on the FEMP and describes the FEMP comment response strategy; DOE and regulator interface; the Sitewide Comment Database; networked electronic file management; the process for classifying, analyzing, and responding to comments; integration with base RI/FS documents; and a conclusion
Assessment of Rip-Current Hazards Using Alongshore Topographic Anisotropy at Bondi Beach, Australia
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Enhanced work planning for reduction in landlord costs
The cost of Landlord services constitutes a major portion of the Fernald Environmental Management Project (FEMP) budget. In order to place more resources in the area of actual remediation and cleanup, the Fernald Environmental Restoration Management Corporation (FERMCO) has established a new enhanced work planning initiative through the Integrated Safe Shutdown, Waste Management, and Landlord (ISWL) Project Team. The ISWL Project Team is a planning and coordination group which meets weekly at no additional cost to the DOE; actual field work is funded and implemented through the remedial or operational projects. The purpose of this team is to address issues that will facilitate safe shutdown and/or reduction of utilities in facilities thereby decreasing the infrastructure costs and increasing integration/advanced planning between Waste Management, Safe Shutdown, and Landlord Programs. The ISWL Project Team is the key planning and integration link for near term (one month to one year) integration activities. The ISWL Team is planning for the coordination of integration activities which must be completed to support and facilitate the FEMP`s (1) Safe Shutdown Program, (2) Utility Reduction Program, (3) Waste Programs Management, (4) remediation of all FEMP structures, and (5) ongoing remediation projects
Study Abroad Field Trip Improves Test Performance through Engagement and New Social Networks
Although study abroad trips provide an opportunity for affective and cognitive learning, it is largely assumed that they improve learning outcomes. The purpose of this study is to determine whether a study abroad field trip improved cognitive learning by comparing test performance between the study abroad participants (n = 20) and their peers who did not participate (n = 365). Test performance was statistically identical between these groups before and immediately after the study abroad program. On the final exam, the study abroad participants scored significantly higher. Qualitative methods were used to identify increased engagement with the course material and the creation of new social networks as likely explanations. © 2011 Copyright Taylor and Francis Group, LLC