3,595 research outputs found
Deep Space Network utilization for flight projects, calendar year 1981
A report on the utilization of the Deep Space Network during calendar year 1981 in support of all flight projects is presented. The network expended 63% of its total capability in support of Space Flight projects
A search for massive neutral bosons in orthopositronium decay
We have searched for an exotic decay of orthopositronium into a single photon
and a short-lived neutral boson in the hitherto unexplored mass region above
900 , by noting that this decay is one of few remaining
candidates which could explain the discrepancy of the orthopositronium
decay-rate. A high-resolution measurement of the associated photon energy
spectrum was carried out with a germanium detector to search for a sharp peak
from this two-body decay. Our negative result provides the upper-limits
of\mbox{ } on the branching ratio of such a decay in the
mass region from 847 to 1013 , and excludes the
possibility of this decay mode explaining the discrepancy in the
orthopositronium decay-rate.Comment: a LaTeX file (text 7 pages) and a uuencoded gz-compressed PostScript
file (text 7 pages + figures 4 pages
Two-loop corrections to the decay rate of parapositronium
Order corrections to the decay rate of parapositronium are
calculated. A QED scattering calculation of the amplitude for electron-positron
annihilation into two photons at threshold is combined with the technique of
effective field theory to determine an NRQED Hamiltonian, which is then used in
a bound state calculation to determine the decay rate. Our result for the
two-loop correction is in units of times the
lowest order rate. This is consistent with but more precise than the result
of a previous calculation.Comment: 26 pages, 7 figure
Ventilation of the North Atlantic Ocean during the Last Glacial Maximum: A comparison between simulated and observed radiocarbon ages
The distribution of radiocarbon during simulations of the Last Glacial Maximum with a coupled ocean-atmosphere-sea ice model is compared with sediment core measurements from the equatorial Atlantic Ceara Rise, Blake Ridge, Caribbean Sea, and South China Sea. During these simulations we introduce a perturbation of North Atlantic freshwater fluxes leading to varying strengths of the Atlantic meridional overturning. The best fit with the observations is obtained for an overturning weakened by 40% compared with today. Further, we simulate the phenomenon of an “age reversal” found in deep sea corals, but we suggest that this indicates rather a sudden interruption of deep water formation instead of an increase in ventilation, which was suggested earlier
Ask and You Might Receive: Gender Dynamics and Workplace Negotiations
This thesis explores negotiation processes for remuneration in the workplace. Drawing on a survey of 97 respondents and interviews with employees at a large private university on the East Coast of the United States, it analyzes the impact of gender on negotiation outcomes. It demonstrates that gender-based disparities persist, even when women enter into negotiation processes. The survey and interviews investigate six consequential aspects of workplace negotiation: (1) fear and assumptions in early career negotiations, (2) penalization and deviance, (3) the role of an advocate in the negotiation process, (4) generational differences in approaches to negotiation and in sharing information about remuneration, (5) drivers of negotiation, and (6) tactics and approaches to advance successful negotiation outcomes. In compiling shared experiences and identifying patterns in negotiation outcomes, constructive strategies for successful negotiation in the workplace are developed
Benthic Collector and Grazer Communities Are Threatened by Hemlock Woolly Adelgid-Induced Eastern Hemlock Loss
Eastern hemlock (Tsuga canadensis (L.) is a foundation species in eastern North America where it is under threat from the highly invasive, exotic hemlock woolly adelgid (Adelges tsugae). Eastern hemlock is especially important in riparian areas of Central and Southern Appalachia, so we compared the spatial and temporal composition of benthic collector-gatherers, collector-filterers, and grazers in headwater streams with hemlock-dominated riparian vegetation to those with deciduous tree-dominated riparian vegetation to evaluate the extent to which adelgid-induced hemlock loss could influence composition and abundance of these two functional feeding groups. We found differences in benthic invertebrate abundance and family-level diversity based on riparian vegetation and sampling approach, and, often, riparian vegetation significantly interacted with location or season. Collector-gatherers and grazers were more abundant in eastern hemlock streams in the summer, when hemlock litter is readily available and deciduous litter is relatively sparse. Riparian eastern hemlock appears to exert considerable influence on benthic invertebrate functional feeding group composition in headwater stream communities, as expected with a foundation species. With the loss of eastern hemlock due to adelgid-induced mortality, we should expect to see alterations in spatial and temporal patterns of benthic invertebrate abundance and diversity, with potential consequences to both benthic and terrestrial ecosystem function
Composite Skyrme Model with Vector Mesons
We study the composite Skyrme model, proposed by Cheung and G\"{u}rsey,
introducing vector mesons in a chiral Lagrangian. We calculate the static
properties of baryons and compare with results obtained from models without
vector mesons.Comment: LaTeX, 9 pages, 3 figures, to be published in Phys. Rev.
Borderlands
An audio performance, co-created by Monty Adkins (music) and Deborah Middleton (text and voice) and presented by IOU Theatre in the audio-visual laboratory, 'Totum-One'. Middleton's work is presented under the pen-name, Deborah Templeton
Reducing Animal Numbers in a Contact Sentinel Program
Rodent health surveillance using sentinel animals is a critical part of
the preventative health program for most laboratory rodent facilities.
Introduction of animals through a quarantine area is generally one of
the highest biosecurity risk areas in a rodent housing facility. Adequate
health surveillance of animals during the quarantine period is critical
to prevent introducing unwanted microorganisms
Remarks on the Collective Quantization of the SU(2) Skyrme Model
We point out the question of ordering momentum operator in the canonical
\break quantization of the SU(2) Skyrme Model. Thus, we suggest a new
definition for the momentum operator that may solve the infrared problem that
appears when we try to minimize the Quantum Hamiltonian.Comment: 8 pages, plain tex, IF/UFRJ/9
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