17,528 research outputs found
Chemical Analysis of Fish Tissue: Kentucky Army National Guard Wendell H. Ford Western Kentucky Training Site, Muhlenberg County, Kentucky
Thirty-one analytes were measured in fish tissue taken from largemouth bass, catfish, and bluegill harvested from lakes and ponds in reclaimed and unreclaimed coal-mine spoil of Pennsylvanian age. The spoil area is approximately 7,756 acres created primarily from surface mining, and has been used in increasing intensity since 1969 as a training site by the Kentucky Army National Guard. Four fish were harvested for analysis from the area of unreclaimed spoil that resulted from mining prior to 1977, and 15 fish were harvested for analysis from the part of the training facility that was reclaimed by 1985. Twenty-six analytes had values above the method reporting limit, and only one sample, L15-8A, had a mercury concentration of 1.22 mg/kg. This concentration is slightly above the federal Food and Drug Administration action concentration level of 1 mg/kg
A bright coronal downflow seen in multi-wavelength observations: evidence of a bifurcating flux-rope?
Aims: To study the origin and characteristics of a bright coronal downflow
seen after a coronal mass ejection associated with erupting prominences on 5
March 2000.
Methods: This study extends that of Tripathi et al. (A&A, v. 449, pp. 369)
based on the Extreme-ultraviolet Imaging Telescope (EIT), the Soft X-ray
Telescope (SXT) and the Large Angle Spectrometric Coronagraph (LASCO)
observations. We combined those results with an analysis of the observations
taken by the H and the Mk4 coronagraphs at the Mauna Loa Solar
Observatory (MLSO). The combined data-set spans a broad range of temperature as
well as continuous observations from the solar surface out to 30 R_{\sun}.
Results: The downflow started at around 1.6R_{\sun} and contained both hot
and cold gas. The downflow was observed in the H and the Mk4
coronagraphs as well as the EIT and the SXT and was approximately co-spatial
and co-temporal providing evidence of multi-thermal plasma. The H and
Mk4 images show cusp-shaped structures close to the location where the downflow
started. Mk4 observations reveal that the speed of the downflow in the early
phase was substantially higher than the free-fall speed, implying a strong
downward acceleration near the height at which the downflow started.
Conclusions: The origin of the downflow was likely to have been magnetic
reconnection taking place inside the erupting flux rope that led to its
bifurcation.Comment: 15 pages, 11 figure
Water-Quality and -Quantity Data for Abandoned Underground Coal Mines in Eastern Kentucky
Water-quality and -quantity analyses were performed between 1997 and 2003 by the Kentucky Geological Survey under contract from the Kentucky River Authority and the Kentucky Infrastructure Authority to study abandoned underground coal mines as possible water supplies for communities in the Eastern Kentucky Coal Field. The steep terrain of the coal field limits surface-water supplies, and groundwater systems are difficult to locate and often have too low a yield to provide community water supplies. KGS has been working with the Kentucky River Authority, the Kentucky Infrastructure Authority, and local government officials to search for water supplies in abandoned underground coal mines.
The data in the appendices of this report are interpreted in Cumbie and others (2006)
Co-seismic slip from the 1995 July 30 M_w=8.1 Antofagasta, Chile, earthquake as constrained by InSAR and GPS observations
We analyse radar interferometric and GPS observations of the displacement field from the 1995 July 30 M_w= 8.1 Antofagasta, Chile, earthquake and invert for the distribution of slip along the co-seismic fault plane. Using a fixed fault geometry, we compare the use of singular-value decomposition and constrained linear inversion to invert for the slip distribution and find that the latter approach is better resolved and more physically reasonable. Separate inversions using only GPS data, only InSAR data from descending orbits, and InSAR data from both ascending and descending orbits without the GPS data illustrate the complimentary nature of GPS and the presently available InSAR data. The GPS data resolve slip near GPS benchmarks well, while the InSAR provides greater spatial sampling. The combination of ascending and descending InSAR data contributes greatly to the ability of InSAR to resolve the slip model, thereby emphasizing the need to acquire this data for future earthquakes. The rake, distribution of slip and seismic moment of our preferred model are generally consistent with previous seismic and geodetic inversions, although significant differences do exist. GPS data projected in the radar line-of-sight (LOS) and corresponding InSAR pixels have a root mean square (rms) difference of about 3 cm. Comparison of our predictions of vertical displacement and observed uplift from corraline algae have an rms of 10 cm. Our inversion and previous results reveal that the location of slip might be influenced by the 1987 M_w= 7.5 event. Our analysis further reveals that the 1995 slip distribution was affected by a 1988 M_w= 7.2 event, and might have influenced a 1998 M_w= 7.0 earthquake that occurred downdip of the 1995 rupture. Our slip inversion reveals a potential change in mechanism in the southern portion of the rupture, consistent with seismic results. Predictions of the satellite LOS displacement from a seismic inversion and a joint seismic/GPS inversion do not compare favourably with the InSAR observations
Aharonov-Bohm interference in the presence of metallic mesoscopic cylinders
This work studies the interference of electrons in the presence of a line of
magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low
temperature. It is found that, while there is a supplementary phase
contribution from each electron of the mesoscopic cylinder, the sum of these
individual supplementary phases is equal to zero, so that the presence of a
normal-conducting mesoscopic ring at low temperature does not change the
Aharonov-Bohm interference pattern of the incident electron. It is shown that
it is not possible to ascertain by experimental observation that the shielding
electrons have responded to the field of an incident electron, and at the same
time to preserve the interference pattern of the incident electron. It is also
shown that the measuring of the transient magnetic field in the region between
the two paths of an electron interference experiment with an accuracy at least
equal to the magnetic field of the incident electron generates a phase
uncertainty which destroys the interference pattern.Comment: 15 pages, 5 Postscript figure
Teleportation of Nonclassical Wave Packets of light
We report on the experimental quantum teleportation of strongly nonclassical
wave packets of light. To perform this full quantum operation while preserving
and retrieving the fragile non-classicality of the input state, we have
developed a broadband, zero-dispersion teleportation apparatus that works in
conjunction with time-resolved state preparation equipment. Our approach brings
within experimental reach a whole new set of hybrid protocols involving
discrete- and continuous-variable techniques in quantum information processing
for optical sciences
Microstructure identification via detrended fluctuation analysis of ultrasound signals
We describe an algorithm for simulating ultrasound propagation in random
one-dimensional media, mimicking different microstructures by choosing physical
properties such as domain sizes and mass densities from probability
distributions. By combining a detrended fluctuation analysis (DFA) of the
simulated ultrasound signals with tools from the pattern-recognition
literature, we build a Gaussian classifier which is able to associate each
ultrasound signal with its corresponding microstructure with a very high
success rate. Furthermore, we also show that DFA data can be used to train a
multilayer perceptron which estimates numerical values of physical properties
associated with distinct microstructures.Comment: Submitted to Phys. Rev.
Allometric trajectories of body and head morphology in three sympatric Arctic charr (Salvelinus alpinus (L.)) morphs
A study of body and head development in three sympatric reproductively isolated Arctic charr (Salvelinus alpinus (L.)) morphs from a subarctic lake (Skogsfjordvatn, northern Norway) revealed allometric trajectories that resulted in morphological differences. The three morphs were ecologically assigned to a littoral omnivore, a profundal benthivore and a profundal piscivore, and this was confirmed by genetic analyses (microsatellites). Principal component analysis was used to identify the variables responsible for most of the morphological variation of the body and head shape. The littoral omnivore and the profundal piscivore morph had convergent allometric trajectories for the most important head shape variables, developing bigger mouths and relatively smaller eyes with increasing head size. The two profundal morphs shared common trajectories for the variables explaining most of the body and head shape variation, namely head size relative to body size, placement of the dorsal and pelvic fins, eye size and mouth size. In contrast, the littoral omnivore and the profundal benthivore morphs were not on common allometric trajectories for any of the examined variables. The findings suggest that different selective pressures could have been working on traits related to their trophic niche such as habitat and diet utilization of the three morphs, with the two profundal morphs experiencing almost identical environmental conditions
AEGIS: Infrared Spectroscopy of An Infrared Luminous Lyman Break Galaxy at z=3.01
We report the detection of rest--frame 6.2 and 7.7 \micron emission features
arising from Polycyclic Aromatic Hydrocarbons (PAH) in the Spitzer/IRS spectrum
of an infrared-luminous Lyman break galaxy at z=3.01. This is currently the
highest redshift galaxy where these PAH emission features have been detected.
The total infrared luminosity inferred from the MIPS 24 \micron and radio flux
density is 2 L, which qualifies this object as a
so--called hyperluminous infrared galaxy (HyLIRG). However, unlike local
HyLIRGs which are generally associated with QSO/AGNs and have weak or absent
PAH emission features, this HyLIRG has very strong 6.2 and 7.7 \micron PAH
emission. We argue that intense star formation dominates the infrared emission
of this source, although we cannot rule out the presence of a deeply obscured
AGN. This LBG appears to be a distorted system in the HST ACS F606W and F814W
images, possibly indicating that a significant merger or interaction is driving
the large IR luminosity
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