10,091 research outputs found

    Large negotiable certificates of deposit

    Get PDF
    Certificates of deposit ; Money market

    Chameleon effect and the Pioneer anomaly

    Full text link
    The possibility that the apparent anomalous acceleration of the Pioneer 10 and 11 spacecraft may be due, at least in part, to a chameleon field effect is examined. A small spacecraft, with no thin shell, can have a more pronounced anomalous acceleration than a large compact body, such as a planet, having a thin shell. The chameleon effect seems to present a natural way to explain the differences seen in deviations from pure Newtonian gravity for a spacecraft and for a planet, and appears to be compatible with the basic features of the Pioneer anomaly, including the appearance of a jerk term. However, estimates of the size of the chameleon effect indicate that its contribution to the anomalous acceleration is negligible. We conclude that any inverse-square component in the anomalous acceleration is more likely caused by an unmodelled reaction force from solar-radiation pressure, rather than a chameleon field effect.Comment: 16 pages; to appear in Phys.Rev.

    Identification of Ichnofossils in the Glen Rose Limestone, Central Texas

    Get PDF
    Fossil tracks discovered in the Paluxy River bed near Glen Rose, Texas, have for years been presented as important evidence in the creation-evolution controversy. Some of the tracks were Interpreted as human-like, while others were obviously made by a dinosaur and since humans and dinosaurs were supposedly separated (in evolutionary thinking) by about 65 million years, this interpretation was not allowable by evolutionists. As anticreationists Milne and Schafersman admit, Such an occurrence, if verified, would seriously disrupt conventional interpretations of biological and geological history and would support the doctrines of creationism and catastrophism. These data were the data which evolutionists feared the most as paleontologist Tony Thulburn, President of the Australian APE (Association for the Protection of Evolution) related to me on January 8 1986. In 1982, the American Humanist Association began sponsoring a team of four scientists In a continuing attempt to discredit the project, and anti-creationists have over the years published a number of tirades consisting primarily of ridicule and ad hominem arguments

    Three Concurrent Phases of Massive-Star Evolution in a Pulsar-Wind Nebula

    Get PDF
    The nebular material associated the the SNR G54.1+0.3 (hereafter G54) contains the the first reported instance of triggered star formation in the immediate vicinity of a Pulsar and its Wind Nebula (PWN). With 2MASS and Spitzer colors and followup near-IR spectroscopy, we have discovered the presence of a hot, massive and most likely evolved Be-type star among the cluster of stars hosted by the pulsar. This star has probably triggered cloud collapse and formation of at least 11 YSOs, which ring the nebula. In this unique cluster are now identified three concurrent stages of stellar evolution, from massive star birth, post-Main-Sequence transition, and stellar death

    Effect of Superhydrophobic Surface Microstructure on Transient Jet Impingement Cooling

    Get PDF
    Jet impingement is an effective method of rapid surface cooling, and is highly dependent on surface condition and properties. Here, silicon surfaces are modified by ion-etching different micropatterns (posts or holes) on one side and coated with Teflon to make them superhydrophobic (SH). The other side of the surface has a screen-printed resistance heater. Surfaces are heated to temperatures between 200 to 320 °C, and then impinged on by a pure water jet at room temperature with flow rates ranging from 6 to 18 mL/s. Results show that there is little effect of microstructure, although hole surfaces and shorter microstructures tend to have slightly higher heat transfer. Heat transfer from the surfaces to the jet is shown to be highly dependent on jet flow rate, but not surface temperature

    A comparative study of herbage intake, ingestive behaviour and diet selection, and effects of condensed tannins upon body and wool growth in lambs grazing Yorkshire fog (Holcus lanatus) and annual ryegrass (Lolium multiflorum) dominant swards

    Get PDF
    An experiment was carried out from August to early November 1994 to examine differences in diet selection, herbage intake, grazing behaviour and animal performance between weaned lambs rotationally grazing swards of annual ryegrass (Lolium multiflorum)/white clover (Trifolium repens) and Yorkshire fog (Holcus lanatus)/T. repens with or without Lotus corniculatus. There were four replicate groups of six lambs per treatment. The effects of condensed tannins (CT) on lamb production were assessed by twice-daily oral administration of 10g polyethylene glycol (PEG; molecular weight 4000) to half the lambs on each sward. The Lotus content of all swards was very low, and results are presented here for main sward comparisons meaned over lotus treatments. Overall mean estimates of pre-grazing herbage mass and sward surface height for the annual ryegrass and Yorkshire fog swards respectively, were 5820 v. 4360 +/- 190 kg DM/ha (P , P < 0.01) and liveweight gain (141 v. 120 +/- 4.3 g per lamb per day, P < 0.01), although differences in carcass weight (17.9 v. 18.2 +/- 0.3 kg) and FEC transformed values (9.6 v. 11.0 +/- 06 eggs/g fresh faeces) were not significant. The effects of CT on animal performance were greater in Yorkshire fog swards. CT had no significant effects on diet selection, herbage intake and grazing behaviour patterns

    Porous silica spheres as indoor air pollutant scavengers

    Get PDF
    Porous silica spheres were investigated for their effectiveness in removing typical indoor air pollutants, such as aromatic and carbonyl-containing volatile organic compounds (VOCs), and compared to the commercially available polymer styrene-divinylbenzene (XAD-4). The silica spheres and the XAD-4 resin were coated on denuder sampling devices and their adsorption efficiencies for volatile organic compounds evaluated using an indoor air simulation chamber. Real indoor sampling was also undertaken to evaluate the affinity of the silica adsorbents for a variety of indoor VOCs. The silica sphere adsorbents were found to have a high affinity for polar carbonyls and found to be more efficient than the XAD-4 resin at adsorbing carbonyls in an indoor environment

    η\eta Carinae's Dusty Homunculus Nebula from Near-Infrared to Submillimeter Wavelengths: Mass, Composition, and Evidence for Fading Opacity

    Get PDF
    Infrared observations of the dusty, massive Homunculus Nebula around the luminous blue variable η\eta Carinae are crucial to characterize the mass-loss history and help constrain the mechanisms leading to the Great Eruption. We present the 2.4 - 670 μ\mum spectral energy distribution, constructed from legacy ISO observations and new spectroscopy obtained with the {\em{Herschel Space Observatory}}. Using radiative transfer modeling, we find that the two best-fit dust models yield compositions which are consistent with CNO-processed material, with iron, pyroxene and other metal-rich silicates, corundum, and magnesium-iron sulfide in common. Spherical corundum grains are supported by the good match to a narrow 20.2 μ\mum feature. Our preferred model contains nitrides AlN and Si3_3N4_4 in low abundances. Dust masses range from 0.25 to 0.44 MM_\odot but MtotM_{\rm{tot}} \ge 45 MM_\odot in both cases due to an expected high Fe gas-to-dust ratio. The bulk of dust is within a 5"" ×\times 7"" central region. An additional compact feature is detected at 390 μ\mum. We obtain LIRL_{\rm{IR}} = 2.96 ×\times 106^6 LL_\odot, a 25\% decline from an average of mid-IR photometric levels observed in 1971-1977. This indicates a reduction in circumstellar extinction in conjunction with an increase in visual brightness, allowing 25-40\% of optical and UV radiation to escape from the central source. We also present an analysis of 12^{12}CO and 13^{13}CO J=54J = 5-4 through 989-8 lines, showing that the abundances are consistent with expectations for CNO-processed material. The [12^{12}C~{\sc{ii}}] line is detected in absorption, which we suspect originates in foreground material at very low excitation temperatures.Comment: Accepted in Ap

    Interior Models of Uranus and Neptune

    Full text link
    'Empirical' models (pressure vs. density) of Uranus and Neptune interiors constrained by the gravitational coefficients J_2, J_4, the planetary radii and masses, and Voyager solid-body rotation periods are presented. The empirical pressure-density profiles are then interpreted in terms of physical equations of state of hydrogen, helium, ice (H_2O), and rock (SiO_2) to test the physical plausibility of the models. The compositions of Uranus and Neptune are found to be similar with somewhat different distributions of the high-Z material. The big difference between the two planets is that Neptune requires a non-solar envelope while Uranus is best matched with a solar composition envelope. Our analysis suggests that the heavier elements in both Uranus' and Neptune's interior might increase gradually towards the planetary centers. Indeed it is possible to fit the gravitational moments without sharp compositional transitions.Comment: 16 pages, accepted for publication in Ap

    Biological Network Exploration with Cytoscape 3

    Full text link
    Cytoscape is one of the most popular open‐source software tools for the visual exploration of biomedical networks composed of protein, gene, and other types of interactions. It offers researchers a versatile and interactive visualization interface for exploring complex biological interconnections supported by diverse annotation and experimental data, thereby facilitating research tasks such as predicting gene function and constructing pathways. Cytoscape provides core functionality to load, visualize, search, filter, and save networks, and hundreds of Apps extend this functionality to address specific research needs. The latest generation of Cytoscape (version 3.0 and later) has substantial improvements in function, user interface, and performance relative to previous versions. This protocol aims to jump‐start new users with specific protocols for basic Cytoscape functions, such as installing Cytoscape and Cytoscape Apps, loading data, visualizing and navigating the networks, visualizing network associated data (attributes), and identifying clusters. It also highlights new features that benefit experienced users. Curr. Protoc. Bioinform. 47:8.13.1‐8.13.24. © 2014 by John Wiley & Sons, Inc.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143619/1/cpbi0813.pd
    corecore