2,957 research outputs found
Dungeness crab research program
In 1974, the California State Legislature, recognizing the
problem of low yields from the Dungeness crab resource of
central California, directed the Department of Fish and Game
to conduct an investigation into the causes of the decline.
The Operations Research Branch of the Department has conducted
preliminary studies and field operations necessary to formulate the Dungeness Crab Research Program. The objectives,
research design, and work plans are presented for a 4-year
program from July 1, 1975 through August 31, 1979. (38pp.
Structures and materials technology for hypersonic aerospacecraft
Major considerations in structural design of a transatmospheric aerospacecraft are discussed. The general direction of progress in structures and materials technology is indicated, and technical areas in structures and materials where further research and development is necessary are indicated. Various structural concepts under study and materials which appear to be most applicable are discussed. Structural design criteria are discussed with particular attention to the factor-of-safety approach and the probabilistic approach. Structural certification requirements for the aerospacecraft are discussed. The kinds of analyses and tests which would be required to certify the structural integrity, safety, and durability of the aerospacecraft are discussed, and the type of test facility needed to perform structural certification tests is identified
Mesozooplankton Distribution and Abundance in the Pagan River: A Nutrient Enriched Subestuary of the James River, Virginia
The mesozooplankton in the Pagan River was dominated by calanoid copepods, with abundance peaks occurring during late winter-early spring and from late summer into early fall. This included spring, summer, and fall abundance maxima. The total mean abundance of the mesozooplankton was 3,008/m3
Dungeness crab research program: Report for the Year 1976
All larval stages of the 1976 year class, with the exception of the 5th zoeal stage, were found in Gu1f waters January through March. The first post-larval stage was collected in San Pablo Bay in May. Fifty percent of 1976 year class crabs entered the Bay complex as compared to nearly 80% in 1975. The 1976 year class appears relatively weak. No electrophoretic polymorphism was found in Cancer magister to be of value in Dungeness crab population determinations.
Multi-variate correlations comparing crab landings with an
array of oceanographic parameters and the crab density dependent factor were computer-run for both northern and
central California. The most significant correlating factors at the time late stage larvae prevail were sea level and atmospheric pressure for central California and, for northern California, the density dependent factor and sea
surface temperature. Female crabs held at controlled temperatures indicated gonad maturation and spawning
may be induced by increased temperature. Analyses of crab
tissues revealed burdens of petroleum hydrocarbons, silver,
selenium, cadmium, and PCB's higher in central California
crabs, while DDE was found in higher amounts in northern
California crab tissue.
Thru-flow culture systems were developed which should yield about 163 megalopae of Dungeness crabs in 63 days from 1,200 laboratory hatched zoeae.(46pp.
Seasonal Abundance of Autotrophic Picoplankton in the Pagan River, a Nutrient Enriched Subestuary of the James River, Virginia
Autotrophic picoplankton had average monthly concentrations of 73.5 X 106 cells/L in the Pagan River, with summer-early fall maxima of 108 cells/L. The abundance peaks increased with rising water temperatures, declining to their least abundance in mid-winter (105 cells/L)
The compact far infrared emission from the young stellar object IRAS 16293-2422
High resolution far IR observations at 50 and 100 microns were made of the young stellar object (YSO), IRAS 16293-2422. The observations are part of a systematic high resolution study of nearby YSO's. The purpose is to obtain resolution in the far IR comparable to that at other wavelengths. Until recently, the high resolution that has been available in the far IR has been from either IRAS (angular resolution of approx 4 min) or the KAO using standard FIR photometry (approx 35 sec). With scanning techniques, it is possible to obtain 10 sec resolution on bright sources. Such a resolution is necessary to better determine the physical conditions of the YSO, and to compare with model of star formation. In order to better constrain the models for the source, the YSO was observed at both 50 and 100 microns on several flights in 1988 April from the KAO. Estimates are presented of the size both along the major and minor axis of the disk, as well as estimates of the dust temperature and 100 micron opacity for the YSO
Baryon chiral perturbation theory with virtual photons and leptons
We construct the general pion-nucleon SU(2) Lagrangian including both virtual
photons and leptons for relativistic baryon chiral perturbation theory up to
fourth order. We include the light leptons as explicit dynamical degrees of
freedom by introducing new building blocks which represent these leptons.Comment: 11 page
Bosonized noncommutative bi-fundamental fermion and S-duality
We perform the path-integral bosonization of the recently proposed
noncommutative massive Thirring model (NCMT) [JHEP0503(2005)037]. This
model presents two types of current-current interaction terms related to the
bi-fundamental representation of the group U(1). Firstly, we address the
bosonization of a bi-fundamental free Dirac fermion defined on a noncommutative
(NC) Euclidean plane \IR_{\theta}^{2}. In this case we show that the fermion
system is dual to two copies of the NC Wess-Zumino-Novikov-Witten model. Next,
we apply the bosonization prescription to the NCMT model living on
\IR_{\theta}^{2} and show that this model is equivalent to two-copies of the
WZNW model and a two-field potential defined for scalar fields corresponding to
the global symmetry plus additional bosonized terms for the
four fermion interactions. The bosonic sector resembles to the one proposed by
Lechtenfeld et al. [Nucl. Phys. B705(2005)477] as the noncommutative
sine-Gordon for a {\sl pair} of scalar fields. The bosonic and fermionic
couplings are related by a strong-weak duality. We show that the couplings of
the both sectors for some representations satisfy similar relationships up to
relevant re-scalings, thus the NC bi-fundamental couplings are two times the
corresponding ones of the NC fundamental (anti-fundamental) and eight times the
couplings of the ordinary massive Thirring and sine-Gordon models.Comment: 18 pages, LaTex. References added. A general product has been considered in the conclusion section . Version to appear in
JHE
Unbraiding the braided tensor product
We show that the braided tensor product algebra
of two module algebras of a quasitriangular Hopf algebra is
equal to the ordinary tensor product algebra of with a subalgebra of
isomorphic to , provided there exists a
realization of within . In other words, under this assumption we
construct a transformation of generators which `decouples' (i.e.
makes them commuting). We apply the theorem to the braided tensor product
algebras of two or more quantum group covariant quantum spaces, deformed
Heisenberg algebras and q-deformed fuzzy spheres.Comment: LaTex file, 29 page
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