3,729 research outputs found
The artesian water of the Ruskin area of Hillsborough County, Florida: interim report
The purpose of the investigation is to make a detailed study of the
geology and ground water in the Ruskin area, especially as related to the
problem of salt-water encroachment. The major objectives of the program
includes:
(1) An inventory of wells to determine their number and distribution,
their depths and diameters, and other pertinent information.
(2) A study of artesian pressures.
(3) Analyses of water from selected wells to determine the location
and extent of any areas in which the artesian water is salty.
(4) A study of the surface and subsurface geology as related to the
occurrence and movement of ground water.
(5) An estimate of the quantity of ground water withdrawn.
(PDF contains 24 pages.
A New Technique for Determining Europium Abundances in Solar-Metallicity Stars
We present a new technique for measuring the abundance of europium, a
representative r-process element, in solar-metallicity stars. Our algorithm
compares LTE synthetic spectra with high-resolution observational spectra using
a chi-square-minimization routine. The analysis is fully automated, and
therefore allows consistent measurement of blended lines even across very large
stellar samples. We compare our results with literature europium abundance
measurements and find them to be consistent; we also find our method generates
smaller errors.Comment: 10 pages, 7 figure
Interim report on the ground-water resources of Manatee County, Florida
A large part of western Manatee County is devoted to the growing of
winter vegetables and citrus fruits. As in most of peninsular Florida,
rainfall in the county during the growing season is not sufficient for crop
production and large quantites of artesian water are used for irrigation.
The large withdrawals of artesian water for irrigation result in a considerable
decline of the artesian head in the western part of the county. This seasonal
decline of the artesian head has become larger as the withdrawal of artesian
water has increased. The lowering of the fresh-water head in some coastal areas in the State
has resulted in an infiltration of sea water into the water-bearing formations.
The presence of salty water in the artesian aquifer in parts of the coastal area
of Manatee County indicates that sea water may also have entered the waterbearing
formations in this area as a result of the decline of artesian pressure
during the growing season. The purpose of the investigation is to make a detailed study of the geology
and ground-water resources of the county, primarily to determine whether
salt-water encroachment has occurred or is likely to occur in the coastal area. (PDF contains 38 pages.
The Local Leo Cold Cloud and New Limits on a Local Hot Bubble
We present a multi-wavelength study of the local Leo cold cloud (LLCC), a
very nearby, very cold cloud in the interstellar medium. Through stellar
absorption studies we find that the LLCC is between 11.3 pc and 24.3 pc away,
making it the closest known cold neutral medium cloud and well within the
boundaries of the local cavity. Observations of the cloud in the 21-cm HI line
reveal that the LLCC is very cold, with temperatures ranging from 15 K to 30 K,
and is best fit with a model composed of two colliding components. The cloud
has associated 100 micron thermal dust emission, pointing to a somewhat low
dust-to-gas ratio of 48 x 10^-22 MJy sr^-1 cm^2. We find that the LLCC is too
far away to be generated by the collision among the nearby complex of local
interstellar clouds, but that the small relative velocities indicate that the
LLCC is somehow related to these clouds. We use the LLCC to conduct a shadowing
experiment in 1/4 keV X-rays, allowing us to differentiate between different
possible origins for the observed soft X-ray background. We find that a local
hot bubble model alone cannot account for the low-latitude soft X-ray
background, but that isotropic emission from solar wind charge exchange does
reproduce our data. In a combined local hot bubble and solar wind charge
exchange scenario, we rule out emission from a local hot bubble with an 1/4 keV
emissivity greater than 1.1 Snowdens / pc at 3 sigma, 4 times lower than
previous estimates. This result dramatically changes our perspective on our
local interstellar medium.Comment: 13 pages, 12 figures. Accepted for publication in the Astrophysical
Journal. Vector figure version available at
http://www.astro.columbia.edu/~jpeek
The use of phenyl-Sepharose for the affinity purification of proteinases
Phenyl-Sepharose is most often used as an adsorbent for hydrophobic interaction chromatography (HIC). We report on its effective use for the affinity purification of some extracellular thermostable proteinases from bacterial sources. Proteinases belonging to the serine, aspartate and metallo mechanistic classes were effective retained by the media. Purification factors in the range of 2.9–60 and enzyme activity yields in excess of 88% were obtained. In some cases homogeneous enzyme was obtained from culture supernatants in a single step. A number of other proteinases from mammalian sources were also retained. The specificity of the enzyme/support interaction was studied. Proteinases complexed with peptide inhibitors (pepstatin and chymostatin) showed reduced binding to phenyl Sepharose indicating with the active site cleft whereas modification with low molecular weight active site directed inactivators such as PMSF and DAN did not, indicating that binding may not be dependent on the catalytic site. Pepsinogen and the pro-enzyme form of the serine proteinase from the thermophilic Bacillus sp. strain Ak.1 were not retained by the media and could be resolved in an efficient manner from their active counterparts
Record of wells in the Ruskin area of Hillsborough County, FLorida
A detailed study of the geology and ground-water
resources of the Ruskin area (fig. 1) was made during the
period from 1950 to 1955, by the U. S. Geological Survey in
cooperation with the Florida Geological Survey and the Board
of County Commissioners of Hillsborough County. The
results of this study are given in a report by Harry M. Peek
entitled "The artesian water of the Ruskin area of Hillsborough
County, Florida" and published by the Florida Geological
Survey as Report of Investigations No. 21.
This report contains tables of well records that were
compiled from data collected during that investigation. The
well-numbering system used in the tables is based on latitude
and longitude. (PDF contains 88 pages.
Record of wells in Manatee County, Florida
A detailed study of the geology and ground-water
resources of Manatee County (fig. 1) was made during the
period from 1950 to 1955. This report contains a table of well records that was
compiled from data collected during that investigation. The
well-numbering system used in the table is based on latitude
and longitude. (PDF contains 204 pages.
Physical Properties of Complex C Halo Clouds
Observations from the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) Survey
of the tail of Complex C are presented and the halo clouds associated with this
complex cataloged. The properties of the Complex C clouds are compared to
clouds cataloged at the tail of the Magellanic Stream to provide insight into
the origin and destruction mechanism of Complex C. Magellanic Stream and
Complex C clouds show similarities in their mass distributions (slope = -0.7
and -0.6, respectively) and have a common linewidth of 20 - 30 km/s (indicative
of a warm component), which may indicate a common origin and/or physical
process breaking down the clouds. The clouds cataloged at the tail of Complex C
extend over a mass range of 10^1.1 to 10^4.8 solar masses, sizes of 10^1.2 to
10^2.6 pc, and have a median volume density of 0.065 cm^(-3) and median
pressure of (P/k) = 580 K cm^{-3}. We do not see a prominent two-phase
structure in Complex C, possibly due to its low metallicity and inefficient
cooling compared to other halo clouds. From assuming the Complex C clouds are
in pressure equilibrium with a hot halo medium, we find a median halo density
of 5.8 x 10^(-4) cm^(-3), which given a constant distance of 10 kpc, is at a
z-height of ~3 kpc. Using the same argument for the Stream results in a median
halo density of 8.4 x 10^(-5) x (60kpc/d) cm^(-3). These densities are
consistent with previous observational constraints and cosmological
simulations. We also assess the derived cloud and halo properties with three
dimensional grid simulations of halo HI clouds and find the temperature is
generally consistent within a factor of 1.5 and the volume densities, pressures
and halo densities are consistent within a factor of 3.Comment: Accepted for publication in AJ. 54 pages, including 6 tables and 16
figure
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