2,095 research outputs found
Flood of September 20-23, 1969 in the Gadsden County area, Florida
The center of low pressure of a tropical disturbance which
moved northward in the Gulf of Mexico, reached land between
Panama City and Port St. Joe, Florida, on September 20, 1969. This
system was nearly stationary for 48 hours producing heavy rainfall
in the Quincy-Havana area, 70-80 miles northeast of the center.
Rainfall associated with the tropical disturbance exceeded 20
inches over a part of Gadsden County, Florida, during September 20
through 23, 1969, and the maximum rainfall of record occurred at
Quincy with 10.87 inches during a 6-hour period on September 21.
The 48-hour maximum of 17.71 inches exceeded the 1 in 100-year
probability of 16 inches for a 7-day period.
The previous maximum rainfall of record at Quincy (more than
12 inches) was on September 14-15, 1924. The characteristics of this
historical storm were similar in path and effect to the September
1969 tropical disturbance.
Peak runoff from a 1.4-square mile area near Midway, Florida,
was 1,540 cfs (cubic feet per second) per square mile. A peak discharge
of 45,600 cfs on September 22 at the gaging station on the
Little River near Quincy exceeded the previous peak of 25,400 cfs
which occurred on December 4, 1964. The peak discharge of 89,400
cfs at Ochlockonee River near Bloxham exceeded the April 1948
peak of 50,200 cfs, which was the previous maximum of record, by
1.8 times. Many flood-measurement sites had peak discharges in
excess of that of a 50-year flood.
Nearly 520,000 in contractual work was required to replace four
bridges that were destroyed. Agricultural losses were estimated at
$1,000,000. (44 page document
State of the Great Barrier Reef World Heritage Area Workshop : proceedings of a technical workshop held in Townsville, Queensland, Australia, 27-29 November 1995
State of the Environment Reporting is increasingly being seen as an important part of
environmental management and is required at the national level as well as within several states.
Although there are or have been, a number of long-standing and quite comprehensive
monitoring and assessment programs on the Great Barrier Reef, the results of many of these
programs have never been summarised in a management context and no overall summary of all
of these programs has ever been attempted
Polarized Dirac fermions in de Sitter spacetime
The tetrad gauge invariant theory of the free Dirac field in two special
moving charts of the de Sitter spacetime is investigated pointing out the
operators that commute with the Dirac one. These are the generators of the
symmetry transformations corresponding to isometries that give rise to
conserved quantities according to the Noether theorem. With their help the
plane wave spinor solutions of the Dirac equation with given momentum and
helicity are derived and the final form of the quantum Dirac field is
established. It is shown that the canonical quantization leads to a correct
physical interpretation of the massive or massless fermion quantum fields.Comment: 19 pages, LaTeX w AMS sym
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Combining Sources of Description for Approximating Music Similarity Ratings
In this paper, we compare the effectiveness of basic acoustic features and genre annotations when adapting a music similarity model to user ratings. We use the Metric Learning to Rank algorithm to learn a Mahalanobis metric from comparative similarity ratings in in the MagnaTagATune database. Using common formats for feature data, our approach can easily be transferred to other existing databases. Our results show that genre data allow more effective learning of a metric than simple audio features, but a combination of both feature sets clearly outperforms either individual set
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Case study: Evaluation of a scenario for the reuse of structures in the production area at Fernald
The potential for the reuse of uncontaminated structures at federal facilities that are being remediated should be evaluated. Although various factors often limit the viability of such reuse, it may be economically attractive to reuse selected structures. Consideration of a hypothetical reuse scenario for the US Department of Energy`s Fernald, Ohio facility shows that the reuse of selected buildings that were not significantly contaminated by production activities at the site may be considerably less expensive than the construction of new ones. The cost of removal of existing buildings is a major factor influencing the relative advantages of these two options. For Fernald, no need for the facility`s buildings has been identified; however, the reuse of structures may be a viable option at other facilities
Cryptic loxP sites in mammalian genomes: genome-wide distribution and relevance for the efficiency of BAC/PAC recombineering techniques
Cre is widely used for DNA tailoring and, in combination with recombineering techniques, to modify BAC/PAC sequences for generating transgenic animals. However, mammalian genomes contain recombinase recognition sites (cryptic loxP sites) that can promote illegitimate DNA recombination and damage when cells express the Cre recombinase gene. We have created a new bioinformatic tool, FuzznucComparator, which searches for cryptic loxP sites and we have applied it to the analysis of the whole mouse genome. We found that cryptic loxP sites occur frequently and are homogeneously distributed in the genome. Given the mammalian nature of BAC/PAC genomic inserts, we hypothesised that the presence of cryptic loxP sites may affect the ability to grow and modify BAC and PAC clones in E. coli expressing Cre recombinase. We have observed a defect in bacterial growth when some BACs and PACs were transformed into EL350, a DH10B-derived bacterial strain that expresses Cre recombinase under the control of an arabinose-inducible promoter. In this study, we have demonstrated that Cre recombinase expression is leaky in un-induced EL350 cells and that some BAC/PAC sequences contain cryptic loxP sites, which are active and mediate the introduction of single-strand nicks in BAC/PAC genomic inserts
Dynamics of the Hubbard model: a general approach by time dependent variational principle
We describe the quantum dynamics of the Hubbard model at semi-classical
level, by implementing the Time-Dependent Variational Principle (TDVP)
procedure on appropriate macroscopic wavefunctions constructed in terms of
su(2)-coherent states. Within the TDVP procedure, such states turn out to
include a time-dependent quantum phase, part of which can be recognized as
Berry's phase. We derive two new semi-classical model Hamiltonians for
describing the dynamics in the paramagnetic, superconducting, antiferromagnetic
and charge density wave phases and solve the corresponding canonical equations
of motion in various cases. Noticeably, a vortex-like ground state phase
dynamics is found to take place for U>0 away from half filling. Moreover, it
appears that an oscillatory-like ground state dynamics survives at the Fermi
surface at half-filling for any U. The low-energy dynamics is also exactly
solved by separating fast and slow variables. The role of the time-dependent
phase is shown to be particularly interesting in the ordered phases.Comment: ReVTeX file, 38 pages, to appear on Phys. Rev.
Upper estimate of martingale dimension for self-similar fractals
We study upper estimates of the martingale dimension of diffusion
processes associated with strong local Dirichlet forms. By applying a general
strategy to self-similar Dirichlet forms on self-similar fractals, we prove
that for natural diffusions on post-critically finite self-similar sets
and that is dominated by the spectral dimension for the Brownian motion
on Sierpinski carpets.Comment: 49 pages, 7 figures; minor revision with adding a referenc
Effect of Chaotic Noise on Multistable Systems
In a recent letter [Phys.Rev.Lett. {\bf 30}, 3269 (1995), chao-dyn/9510011],
we reported that a macroscopic chaotic determinism emerges in a multistable
system: the unidirectional motion of a dissipative particle subject to an
apparently symmetric chaotic noise occurs even if the particle is in a
spatially symmetric potential. In this paper, we study the global dynamics of a
dissipative particle by investigating the barrier crossing probability of the
particle between two basins of the multistable potential. We derive
analytically an expression of the barrier crossing probability of the particle
subject to a chaotic noise generated by a general piecewise linear map. We also
show that the obtained analytical barrier crossing probability is applicable to
a chaotic noise generated not only by a piecewise linear map with a uniform
invariant density but also by a non-piecewise linear map with non-uniform
invariant density. We claim, from the viewpoint of the noise induced motion in
a multistable system, that chaotic noise is a first realization of the effect
of {\em dynamical asymmetry} of general noise which induces the symmetry
breaking dynamics.Comment: 14 pages, 9 figures, to appear in Phys.Rev.
Chemically induced solidification : a new way to produce thin solid-near- net shapes
In-situ observation of the solidification of high carbon steel (4 wt% C) through decarburization has been carried out as a feasibility study into reducing high power usage and high CO2 production involved in steel making. Decarburization has been carried out under both air and pure N2 atmospheres at temperature of 1573K (1300 Ā°C) and 1673K (1400 Ā°C). A solidified shell of around 500Ī¼m was formed with carbon concentrations reduced down to 1% in as short as 18s
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