7,427 research outputs found
Optical BVRI Photometry of Common Proper Motion F/G/K+M Wide Separation Binaries
We present optical (BVRI) photometric measurements of a sample of 76 common
proper motion wide separation main sequence binary pairs. The pairs are
composed of a F-, G-, or K-type primary star and an M-type secondary. The
sample is selected from the revised NLTT catalog and the LSPM catalog. The
photometry is generally precise to 0.03 mag in all bands. We separate our
sample into two groups, dwarf candidates and subdwarf candidates, using the
reduced proper motion (RPM) diagram constructed with our improved photometry.
The M subdwarf candidates in general have larger colors than the M dwarf
candidates at a given color. This is consistent with an average
metallicity difference between the two groups, as predicted by the
PHOENIX/BT-Settl models. The improved photometry will be used as input into a
technique to determine the metallicities of the M-type stars.Comment: 26 pages, 8 figures, accepted for publication in A
Slip Along the Superstition Hills Fault Associated with the 24 November 1987 Superstition Hills, California, Earthquake
Surficial slip along the entire mapped length of the Superstition Hills fault in southern California occurred in association with the Superstition Hills earthquake (M_s 6.6)of 24 November 1987. We made repeated measurements of surface slip at 36 sites along the fault and occupied 64 sites at least once. At our sites, dextral slip was as high as 48.5 cm 1 day after the earthquake and 71 cm 2 months after. The measurements show that slip during the period from hr to several hundred hr following the event is described by a simple power law of time. Extrapolation to t = 1 min indicates that co-seismic slippage ranged from 5
to 23 cm at 10 of our best recorded sites, suggesting that finite co-seismic slippage occurred along the length of the fault. These extrapolations are supported by a measurement made at Imler Road 30 min after the shock.
Measurements are complete through October 1988. At many sites, the form of slip-rate was decay changed from power law to a function of log time during the interval between 300 and 500 hr after the earthquake. Logarithmic slip-rate decay in time was observed for a period of several yr after the Parkfield, Borrego Mountain, and Imperial Valley earthquakes. Those measurements may have begun too late to resolve power-law behavior at early times. If current logarithmic behavior of the Superstition Hills fault persists, right-lateral slippage will approach 90 cm 10 yr after the rupture.
Changes in the along-fault displacement profile correlate well with geometric features including a fault bend and a major fault step. Moreover, slip behavior appears to be correlated to the thickness of sedimentary cover along the fault. Also, the northern half of the fault is bounded by a large block of continental crystalline basement. The presence of this block may have contributed to the
relatively uniform early slip behavior observed there
The effect of boundary adaptivity on hexagonal ordering and bistability in circularly confined quasi hard discs
The behaviour of materials under spatial confinement is sensitively dependent
on the nature of the confining boundaries. In two dimensions, confinement
within a hard circular boundary inhibits the hexagonal ordering observed in
bulk systems at high density. Using colloidal experiments and Monte Carlo
simulations, we investigate two model systems of quasi hard discs under
circularly symmetric confinement. The first system employs an adaptive circular
boundary, defined experimentally using holographic optical tweezers. We show
that deformation of this boundary allows, and indeed is required for, hexagonal
ordering in the confined system. The second system employs a circularly
symmetric optical potential to confine particles without a physical boundary.
We show that, in the absence of a curved wall, near perfect hexagonal ordering
is possible. We propose that the degree to which hexagonal ordering is
suppressed by a curved boundary is determined by the `strictness' of that wall.Comment: 10 pages, 8 figure
An Economic Comparison of Composted Manure and Commercial Nitrogen with Imperfect Information
The economic feasibility of fertilizing irrigated grain sorghum with compos ted manure is evaluated using net return budgeting and production function analysis. Although the use of compost is technically feasible, the economic analysis indicates that compost does not comprise a large percentage of the nitrogen source in the profit-maximizing combination with commercial fertilizer.Composted manure, commercial nitrogen, net returns budgeting, production function analysis, irrigated grain sorghum, Crop Production/Industries,
Landau-gauge condensates from the quark propagator on the lattice
We compute the dimension-2 condensate, , and the dimension-4 mixed
condensate, , from the recent quenched lattice results for the
quark propagator in the Landau gauge. We fit the lattice data to the Operator
Product Expansion in the "fiducial" region 1.2 GeV < Q < 3 GeV. Our result for
the dynamical gluon mass at the scale of 10 GeV^2 is m_A=600-650 MeV, in
agreement with independent determinations. For the mixed Landau gauge
condensate of dimension-4 we get alpha_s = (-0.11 +/- 0.03)
GeV^4. This value is an order of magnitude larger than the gluon
condensate.Comment: 4 pages, 3 figures, references adde
Identification of structure in condensed matter with the topological cluster classification
We describe the topological cluster classification (TCC) algorithm. The TCC
detects local structures with bond topologies similar to isolated clusters
which minimise the potential energy for a number of monatomic and binary simple
liquids with particles. We detail a modified Voronoi bond detection
method that optimizes the cluster detection. The method to identify each
cluster is outlined, and a test example of Lennard-Jones liquid and crystal
phases is considered and critically examined.Comment: 28 pages, 28 figure
Gender Presentation and Membership Bias in Greek Organizations
The study objective was to explore the possibility of discrimination and bias based on perceived gender presentation. In this study, subjects were female and male undergraduate students of both Greek and non-Greek affiliations at a University in the Southeastern United States. Subjects were asked to rate the probability of extending group membership to others based on perceived visual gender appearance. In the pilot study, 150 University of Central Florida students were polled to assess three categories of visual gender presentation in pictures: average gender presentation (typical female or male), extreme gender presentation (extremely feminine or extremely masculine) and non-traditional gender presentation (masculine females or effeminate males). Three pictures of each gender presentation category were then chosen for the final study. In both studies, The Crowne-Marlowe (1964) Social Desirability Scale (CMDS) was administered. Results indicated no difference in the ratings between Greek and non-Greek participants. However, the results did show a statistically significant bias against individuals of average and non-traditional gender presentation versus individuals who represented extreme gender presentation. Hence, subjects were more likely to extend membership to individuals who appeared to be extremely feminine or extremely masculine. There was also a statistically significant bias favoring average over non-traditional gender presentation individuals. Additionally, social desirability bias played a significant role in how subjects made their selection. The study not only shows significant relationships between gender presentation and discrimination, but also provides evidence that male students prefer hyper-masculine males and female students prefer hyper-feminine females
Ultrasonic Bacscatter from Embedded Cylinders
Advanced composite materials present unique challenges for nondestructive evaluation of their material properties and state of health or damage. Stitches and other through-the-thickness reinforcements are becoming much more common because of their ability to give substantially improved three-dimensional strength to finished components. They also allow textile preforms to hold their shapes before and during resin transfer molding, and can be important in automated tow-placement processes. Ultrasonic testing of advanced composites is desirable before, during and after consolidation and curing in order to monitor both the initial fabrication and the eventual inevitable structural degradation as the composite structure ages. Unfortunately, the very stitches that improve the properties of the composites interfere with the usual inspection methods. This difficulty can be overcome, however, if the interaction of the probing ultrasonic radiation with the through-the-thickness reinforcements can be understood and quantified. In this paper we present the results of our recent study which has considered theoretically and experimentally the scattering of elastic waves from embedded cylindrical elastic scatterers. In particular, we have derived an exact and analytic, closed-form solution for the oblique polar backscatter from these structures and then have compared our theoretical results with ultrasonic immersion tank experiments conducted on wires, fibers and tows embedded in polymeric materials
Maximizing Access through Consortial Partnership: Mississippi State Univeristy Libraries\u27 Journal Expansion Project
Consortial licenses with online access clauses can offer libraries the opportunity to begin new journal subscriptions at no additional cost and without losing access to existing subscriptions. Mississippi State University (MSU) participates in consortial partnerships that provide online access to all Elsevier and Wiley journals to which any partner subscribes. The license agreements prohibit simply canceling duplicate subscriptions, but allow any library to swap existing subscriptions for titles of equal cost. In 2006, librarians realized MSU was paying for access that it would retain regardless of whether it maintained subscriptions because many subscriptions were duplicated with partner libraries. This article describes a project that allowed MSU to provide online access to an additional 60 journals at no additional cost
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