127 research outputs found
High Frequency Radar Wind Turbine Interference Community Working Group Report
Land-based High Frequency (HF) Radars provide critically important observations of the coastal ocean that will be adversely affected by the spinning blades of utility-scale wind turbines. Pathways to mitigate the interference of turbines on HF radar observations exist for small number of turbines; however, a greatly increased pace of research is required to understand how
to minimize the complex interference patterns that will be caused by the large arrays of turbines planned for the U.S. outer continental shelf. To support the U.S.âs operational and scientific needs, HF radars must be able to collect high-quality measurements of the oceanâs surface inand around areas with significant numbers of wind turbines. This is a solvable problem, but given the rapid pace of wind energy development, immediate action is needed to ensure that HF radar wind turbine interference mitigation efforts keep pace with the planned build out of turbines
Ornamental marine species culture in the coral triangle: seahorse demonstration project in the Spermonde Islands, Sulawesi, Indonesia.
Ornamental marine species ('OMS') provide valuable income for developing nations in the Indo-Pacific Coral Triangle, from which most of the specimens are exported. OMS culture can help diversify livelihoods in the region, in support of management and conservation efforts to reduce destructive fishing and collection practices that threaten coral reef and seagrass ecosystems. Adoption of OMS culture depends on demonstrating its success as a livelihood, yet few studies of OMS culture exist in the region. We present a case study of a land-based culture project for an endangered seahorse (Hippocampus barbouri) in the Spermonde Islands, Sulawesi, Indonesia. The business model demonstrated that culturing can increase family income by seven times. A Strengths Weaknesses Opportunities Threats (SWOT) analysis indicated good collaboration among diverse stakeholders and opportunities for culturing non-endangered species and for offshoot projects, but complicated permitting was an issue as were threats of market flooding and production declines. The OMS international market is strong, Indonesian exporters expressed great interest in cultured product, and Indonesia is the largest exporting country for H. barbouri. Yet, a comparison of Indonesia ornamental marine fish exports to fish abundance in a single local market indicated that OMS culture cannot replace fishing livelihoods. Nevertheless, seahorse and other OMS culture can play a role in management and conservation by supplementing and diversifying the fishing and collecting livelihoods in the developing nations that provide the majority of the global OMS
The Balanced Threat Agreement for Individual Externality Negotiation Problems
This paper introduces a model to analyze individual externalities and the associated negotiation problem, which has been largely neglected in the game theoretic literature. Following an axiomatic perspective, we propose a solution, as a payoff sharing scheme, called the balanced threat agreement, for such problems. It highlights an agentâs potential influences on all agents by threatening to enter or quit. We further study the solution by investigating its consistency. We also offer a discussion on the related stability issue
Signals for a Transition from Surface to Bulk Emission in Thermal Multifragmentation
Excitation-energy-gated two-fragment correlation functions have been studied
between 2 to 9A MeV of excitation energy for equilibrium-like sources formed in
and p + Au reactions at beam momenta of 8,9.2 and 10.2 GeV/c.
Comparison of the data to an N-body Coulomb-trajectory code shows a decrease of
one order of magnitude in the fragment emission time in the excitation energy
interval 2-5A MeV, followed by a nearly constant breakup time at higher
excitation energy. The observed decrease in emission time is shown to be
strongly correlated with the increase of the fragment emission probability, and
the onset of thermally-induced radial expansion. This result is interpreted as
evidence consistent with a transition from surface-dominated to bulk emission
expected for spinodal decomposition.Comment: 11 pages including 3 postscript figures (1 color
Statistical Multifragmentation in Central Au+Au Collisions at 35 MeV/u
Multifragment disintegrations, measured for central Au + Au collisions at E/A
= 35 MeV, are analyzed with the Statistical Multifragmentation Model. Charge
distributions, mean fragment energies, and two-fragment correlation functions
are well reproduced by the statistical breakup of a large, diluted and
thermalized system slightly above the multifragmentation threshold.Comment: Latex file, 8 pages + 4 postscript figures available upon request
from [email protected]
Multifragment production in Au+Au at 35 MeV/u
Multifragment disintegration has been measured with a high efficiency
detection system for the reaction at . From the event
shape analysis and the comparison with the predictions of a many-body
trajectories calculation the data, for central collisions, are compatible with
a fast emission from a unique fragment source.Comment: 9 pages, LaTex file, 4 postscript figures available upon request from
[email protected]. - to appear in Phys. Lett.
Correlations and Characterization of Emitting Sources
Dynamical and thermal characterizations of excited nuclear systems produced
during the collisions between two heavy ions at intermediate incident energies
are presented by means of a review of experimental and theoretical work
performed in the last two decades. Intensity interferometry, applied to both
charged particles (light particles and intermediate mass fragments) and to
uncharged radiation (gamma rays and neutrons) has provided relevant information
about the space-time properties of nuclear reactions. The volume, lifetime,
density and relative chronology of particle emission from decaying nuclear
sources has been extensively explored and has provided valuable information
about the dynamics of heavy-ion collisions. Similar correlation techniques
applied to coincidences between light particles and complex fragments are also
presented as a tool to determine the internal excitation energy of excited
primary fragments as it appears in secondary-decay phenomena.Comment: To appear on Euorpean Physics Journal A as part of the Topical Volume
"Dynamics and Thermodynamics with Nuclear Degrees of Freedom
Source shape determination with directional fragment-fragment velocity correlations
Correlation functions, constructed from directional projections of the
relative velocities of fragments, are used to determine the shape of the
breakup volume in coordinate space. For central collisions of 129Xe + natSn at
50 MeV per nucleon incident energy, measured with the 4pi multi-detector INDRA
at GSI, a prolate shape aligned along the beam direction with an axis ratio of
1:0.7 is deduced. The sensitivity of the method is discussed in comparison with
conventional fragment-fragment velocity correlations.Comment: 12 pages, 5 figures, subm. to Phys. Lett.
Light-Ion-Induced Multifragmentation: The ISiS Project
An extensive study of GeV light-ion-induced multifragmentation and its
possible interpretation in terms of a nuclear liquid-gas phase transition has
been performed with the Indiana Silicon Sphere (ISiS)4 pi detector array.
Measurements were performed with 5-15 GeV/c p, pbar, and pion beams incident on
Au and 2-5 GeV He incident on Ag and Au targets.
Both the reaction dynamics and the subsequent decay of the heavy residues have
been explored. The data provide evidence for a dramatic change in the reaction
observables near an excitation energy of E*/A = 4-5 MeV per residue nucleon. In
this region, fragment multiplicities and energy spectra indicate emission from
an expanded/dilute source on a very short time scale (20-50 fm/c). These
properties, along with caloric curve and scaling-law behavior, yield a pattern
that is consistent with a nuclear liquid-gas phase transition.Comment: 67 pages, 44 figures, all included in tar fil
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