867 research outputs found
Feasibility of surveying pesticide coverage with airborne fluorometer
Response of a Fraunhofer line discriminator (FLD) to varying distributions of granulated corncobs stained with varying concentrations of Rhodamine WT dye was tested on the ground and from an H-19 helicopter. The granules are used as a vehicle for airborne emplacement of poison to control fire ants in the eastern and southeastern United States. Test results showed that the granules are detectable by FLD but that the concentration must be too great to be practical with the present apparatus. Possible methods for enhancement of response may include: (1) increasing dye concentration; (2) incorporating with the poisoned granules a second material to carry the dye alone; (3) use of a more strongly fluorescent substance (at 5890 A); (4) modifying the time interval after dyeing, or modifying the method of dyeing; (5) modifying the FLD for greater efficiency, increased field of view or larger optics; or (6) experimenting with laser-stimulated fluorescence
Test of airborne fluorometer over land surfaces and geologic materials
Response of an experimental Fraunhofer line discriminator to a wide range of surficial deposits common in deserts and semideserts was tested in the laboratory and from an H-19 helicopter. No signals attributable to fluorescence were recorded during 540 miles of aerial traverses over southeastern California and west-central Arizona. It was concluded that exposed surfaces of target materials throughout the traverses were either nonluminescent at 5890 A or not sufficiently so to be detectable. It cannot be ruled out that the lack of fluorescence is partly attributable to surficial coatings of nonluminescent weathered material. The principal route surveyed from the air was from Needles, California to Furnace Creek Ranch, Death Valley and return, via the Amargosa River valley, Silurian Lake (dry), Silver Lake (dry), and Soda Lake (dry). Principal targets traversed were unconsolidated clastic sediments ranging from silty clay to cobbles, and a wide range of evaporite deposits
Spin-lattice Interaction in Ruby Measured by ESR in Uniaxially Stressed Crystals
Spin-lattice Hamiltonian determined for chromium ions in ruby single crystal
Commercial strawberry varieties for Missouri
"MP272/1972/3M"MP272/1972/3
Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling
Electron cyclotron resonant scattering features (CRSFs) are observed as
absorption-like lines in the spectra of X-ray pulsars. A significant fraction
of the computing time for Monte Carlo simulations of these quantum mechanical
features is spent on the calculation of the mean free path for each individual
photon before scattering, since it involves a complex numerical integration
over the scattering cross section and the (thermal) velocity distribution of
the scattering electrons.
We aim to numerically calculate interpolation tables which can be used in
CRSF simulations to sample the mean free path of the scattering photon and the
momentum of the scattering electron. The tables also contain all the
information required for sampling the scattering electron's final spin.
The tables were calculated using an adaptive Simpson integration scheme. The
energy and angle grids were refined until a prescribed accuracy is reached. The
tables are used by our simulation code to produce artificial CRSF spectra. The
electron momenta sampled during these simulations were analyzed and justified
using theoretically determined boundaries.
We present a complete set of tables suited for mean free path calculations of
Monte Carlo simulations of the cyclotron scattering process for conditions
expected in typical X-ray pulsar accretion columns (0.01<B/B_{crit}<=0.12,
where B_{crit}=4.413x10^{13} G and 3keV<=kT<15keV). The sampling of the tables
is chosen such that the results have an estimated relative error of at most
1/15 for all points in the grid. The tables are available online at
http://www.sternwarte.uni-erlangen.de/research/cyclo.Comment: A&A, in pres
Be-Phenomenon in Neutron Star X-ray Binaries
In this work we provide a brief insight into two aspects of Be/X-ray binaries, which are probably involved in production of X-ray outbursts: the evolution of the Be star disk, in particular of its size, and the binary geometry which drives gravitational interaction. Simultaneous X-ray and optical data will aid our investigation of the evolution of Be stars in binaries and the X-ray outburst mechanism
Fish Colonization of a Newly Deployed Vessel-reef off Southeast Florida: Preliminary Results
Fish colonization on the Ebenezer II, a 25.5m merchant marine vessel, was studied from May 2002 - July 2003. The ship was scuttled in May 2002 off Broward County, Florida at a depth of 21m and was censused 10 times during the study period using a modified Bohnsack and Bannerot visual census method. Adjacent natural reefs and the Mcallister, a nearby, 30m tugboat deployed in June 1998, were censused during the same period.
Distinct changes in the fish assemblage on the Ebenezer II were observed throughout the sample period. A pioneer assemblage was observed during the first three months, characterized by the settlement of juvenile fishes «5 cm). Subsequently, numbers of juveniles decreased either through emigration, predation or growth. Resident species made up 52.5% of the total abundance but transient fish species made up 78% of the total fish biomass during the study period.
Surprisingly, attraction of adult fish from both natural reefs and the Mcallister was not a major factor in assemblage fonnation. The primary adult fishes attracted to the Ebenezer II were herbivores. These fishes steadily increased in abundance throughout the study period, presumably due to increased food availability as benthic algal communities developed. A similar trend of increasing herbivores with increasing soak time was observed on the Spiegel Grove, a 153m vessel-reef sunk off Key Largo in May 2002.
The fish assemblages on the artificial reefs were more similar to each other than to natural reefs. Vessel-reefs had sixty species in common, while the Ebenezer II only had thirty-nine species in common with natural reefs. Several species common to vessel-reefs were absent or rare on nearby natural reefs. This may indicate that vessel-reefs are providing early juvenile and adult habitat that is not available on natural reefs
Ab-initio design of perovskite alloys with predetermined properties: The case of Pb(Sc_{0.5} Nb_{0.5})O_{3}
A first-principles derived approach is combined with the inverse Monte Carlo
technique to determine the atomic orderings leading to prefixed properties in
Pb(Sc_{0.5}Nb_{0.5})O_{3} perovskite alloy. We find that some arrangements
between Sc and Nb atoms result in drastic changes with respect to the
disordered material, including ground states of new symmetries, large
enhancement of electromechanical responses, and considerable shift of the Curie
temperature. We discuss the microscopic mechanisms responsible for these
unusual effects.Comment: 5 pages with 2 postscript figures embedde
NuSTAR observation of GRO J1744-28 at low mass accretion rate
We present the spectral analysis of the LMXB GRO J1744-28 using 29 ks
of NuSTAR data taken in 2017 February at a low luminosity of erg/s (3-50 keV). The continuum spectrum is modeled with an absorbed
power-law with exponential cut-off, and an additional iron line component. We
find no obvious indications for a CRSF and therefore perform a detailed
cyclotron line search using statistical methods on the pulse phase-averaged as
well as phase-resolved spectra. The previously detected Type II X-ray bursts
are absent. Clear pulsations at a period of 2.141124(9) Hz are detected. The
pulse profile shows an indication of a secondary peak, which was not seen at
higher flux. The 4 upper limit for the strength of a CRSF in the 3-20
keV band is 0.07 keV, lower than the strength of the line found at higher
luminosity. The detection of pulsations shows that the source did not enter the
"propeller" regime, even though the source flux of
erg/cm/s was almost one order of magnitude below the threshold for the
propeller regime claimed in previous studies on this source. The transition
into the propeller regime in GRO J1744-28 must therefore be below a luminosity
of erg/s, which implies a surface magnetic field G and mass accretion rate g/s.
A change of the CRSF depth as function of luminosity is not unexpected and has
been observed in other sources. This result possibly implies a change in
emission geometry as function of mass accretion rate to reduce the depth of the
line below our detection limit
Feminist phenomenology and the woman in the running body
Modern phenomenology, with its roots in Husserlian philosophy, has been taken up and utilised in a myriad of ways within different disciplines, but until recently has remained relatively under-used within sports studies. A corpus of sociological-phenomenological work is now beginning to develop in this domain, alongside a longer standing literature in feminist phenomenology. These specific social-phenomenological forms explore the situatedness of lived-body experience within a particular social structure. After providing a brief overview of key strands of phenomenology, this article considers some of the ways in which sociological, and particularly feminist phenomenology, might be used to analyse female sporting embodiment. For illustrative purposes, data from an autophenomenographic project on female distance running are also included, in order briefly to demonstrate the application of phenomenology within sociology, as both theoretical framework and methodological approach
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