13,828 research outputs found
Negative thermal expansion in the Prussian Blue analog Zn3[Fe(CN)6]2: X-ray diffraction and neutron vibrational studies
The cubic Prussian Blue (PB) analog, Zn3 [Fe(CN)6]2, has been studied by
X-ray powder diffraction and inelastic neutron scattering (INS). X-ray data
collected at 300 and 84 K revealed negative thermal expansion (NTE) behaviour
for this material. The NTE coefficient was found to be -31.1 x 10-6 K-1. The
neutron vibrational spectrum for Zn3[Fe(CN)6]2.xH2O, was studied in detail. The
INS spectrum showed well-defined, well-separated bands corresponding to the
stretching of and deformation modes of the Fe and Zn octahedra, all below 800
cm-1.Comment: 4 pages, 3 figure
ESTIMATING THE OPPORTUNITY COST OF RECREATION TIME IN AN INTEGRABLE 2-CONSTRAINT COUNT DEMAND MODEL
How researchers treat the opportunity cost of time substantially influences recreation demand parameter and welfare estimates. This paper presents a utility-theoretic and implementable approach, estimating the shadow value of time jointly with recreation demands for coastal activities, using a generalization of the semilog demand system in a two-constraint model.Consumer/Household Economics, Demand and Price Analysis,
Population polygons of tektite specific gravity for various localities in australasia
Comparison of specific gravity of tektites from australia, asia, texas, and czechoslovaki
The LISA Gravitational Wave Foreground: A Study of Double White Dwarfs
Double white dwarfs are expected to be a source of confusion-limited noise
for the future gravitational wave observatory LISA. In a specific frequency
range, this 'foreground noise' is predicted to rise above the instrumental
noise and hinder the detection of other types of signals, e.g., gravitational
waves arising from stellar mass objects inspiraling into massive black holes.
In many previous studies only detached populations of compact object binaries
have been considered in estimating the LISA gravitational wave foreground
signal. Here, we investigate the influence of compact object detached and
Roche-Lobe Overflow Galactic binaries on the shape and strength of the LISA
signal. Since >99% of remnant binaries which have orbital periods within the
LISA sensitivity range are white dwarf binaries, we consider only these
binaries when calculating the LISA signal. We find that the contribution of
RLOF binaries to the foreground noise is negligible at low frequencies, but
becomes significant at higher frequencies, pushing the frequency at which the
foreground noise drops below the instrumental noise to >6 mHz. We find that it
is important to consider the population of mass transferring binaries in order
to obtain an accurate assessment of the foreground noise on the LISA data
stream. However, we estimate that there still exists a sizeable number (~11300)
of Galactic double white dwarf binaries which will have a signal-to-noise ratio
>5, and thus will be potentially resolvable with LISA. We present the LISA
gravitational wave signal from the Galactic population of white dwarf binaries,
show the most important formation channels contributing to the LISA disc and
bulge populations and discuss the implications of these new findings.Comment: ApJ accepted. 28 pages, 11 figures (low resolution), 5 tables, some
new references and changed content since last astro-ph versio
FACTORS INFLUENCING WEST TENNESSEE FARMERS' WILLINGNESS TO PAY FOR A BOLL WEEVIL ERADICATION PROGRAM
Data from a survey were used to evaluate Tennessee farmers' willingness to pay for the boll weevil eradication program. Producer experience, boll weevil control costs, and attitudes about boll weevil damage and insecticide usage after the program were significant explanatory variables and had a positive influence on willingness to pay.Contingent valuation, cotton, regional pest control, pest management groups, Demand and Price Analysis, Resource /Energy Economics and Policy,
A revision of the fish genus Oxyurichthys (Gobioidei: Gobiidae) with descriptions of four new species
The widespread tropical gobionelline fish genus Oxyurichthys is monophyletic due to its species sharing two characters considered derived within the Stenogobius Group of the Gobionellinae (Gobioidei: Gobiidae), a transversely broadened (spatulate) third neural spine that is usually bifid, and no preopercular cephalic lateralis canal. It is most closely related to Oligolepis, also of the Indo-west Pacific, and Ctenogobius, an Atlantic-eastern Pacific genus. Sixteen valid species of Oxyurichthys are redescribed and illustrated and four new species are described, O. limophilus from the western Indian Ocean, O. rapa from French Polynesia, and O. chinensis and O. zeta from the western Pacific. Nineteen species share two additional synapomorphies, a rounded fleshy tongue and a palatine lacking an elongate posterior strut, and form the sister group to the plesiomorphous Oxyurichthys keiensis, known from South Africa and Madagascar. One species, O. stigmalophius, occurs in the western Atlantic. There are no records of this genus from the continental eastern Pacific or the eastern Atlantic. Previous accounts from the Gulf of Guinea region of West Africa are references to Gobionellus occidentalis. Many Oxyurichthys species are limited to shallow estuarine and coastal waters with bottom substrates of silt or other fine sediments, but several are known from depths exceeding 10 m and are often collected by trawling
A revision of the fish genus Oxyurichthys (Gobioidei: Gobiidae) with descriptions of four new species
The widespread tropical gobionelline fish genus Oxyurichthys is monophyletic due to its species sharing two characters considered derived within the Stenogobius Group of the Gobionellinae (Gobioidei: Gobiidae), a transversely broadened (spatulate) third neural spine that is usually bifid, and no preopercular cephalic lateralis canal. It is most closely related to Oligolepis, also of the Indo-west Pacific, and Ctenogobius, an Atlantic-eastern Pacific genus. Sixteen valid species of Oxyurichthys are redescribed and illustrated and four new species are described, O. limophilus from the western Indian Ocean, O. rapa from French Polynesia, and O. chinensis and O. zeta from the western Pacific. Nineteen species share two additional synapomorphies, a rounded fleshy tongue and a palatine lacking an elongate posterior strut, and form the sister group to the plesiomorphous Oxyurichthys keiensis, known from South Africa and Madagascar. One species, O. stigmalophius, occurs in the western Atlantic. There are no records of this genus from the continental eastern Pacific or the eastern Atlantic. Previous accounts from the Gulf of Guinea region of West Africa are references to Gobionellus occidentalis. Many Oxyurichthys species are limited to shallow estuarine and coastal waters with bottom substrates of silt or other fine sediments, but several are known from depths exceeding 10 m and are often collected by trawling
Damaging Economies and Ecosystems: Light Pollution in Logan City
Though the view of city lights is considered a modern beauty, indicative of the strength of the human intellect, it is the cause of an assortment of negative effects. Most street lights emit light radially, sending large portions of the light into the sky, leaving the ground dim. The excess light- light pollution- directed at the atmosphere destroys our ability to view beauty of the night sky and represents a loss of energy and money. Damage is also done to nocturnal and migratory animals as well as greatly affecting local ecosystems. To improve the efficiency of astronomical endeavors, the economy, and ecosystems, small innovations must be made to outdoor light fixtures. This project analyzes the luminosity output of outdoor light fixtures and the ambient light pollution of Utah State University Campus. As Utah State University has a sustainability program, Blue Goes Green, that has already implement lighting codes, the goal of this project is the work with the collegiate administration to renovate old lighting fixtures
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