482 research outputs found

    Results of investigations on an 0.015-scale 140A/B configuration of the Rockwell International space shuttle orbiter (model 49-O) in the NASA/Ames Research Center 3.5-foot hypersonic wind tunnel (OA36)

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    The results of wind tunnel tests of the 140A/B configuration components are reported for the fuselage, canopy, elevons, bodyflaps, pods, engine nozzles, rudder, vertical tail, and wing. The test facility, and data reduction procedures are described. Test results for each component are graphed, and tabulated source data are included

    Examining a Neural Measure of Attentional Bias to Emotional Faces in Social Anxiety and Depression

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    Cognitive theories suggest that attentional biases may contribute to both social anxiety and depression, such that attention may be biased to focus on or away from certain information (e.g., rejecting or sad images; Clark & McManus, 2002; Lemoult & Gotlib, 2019). Although research is mixed, recent studies using a neural measure called the N2pc (an event-related potential) has indicated attentional biases in social anxiety. However, little N2pc research has examined depression or co-occurring depression and social anxiety. The current study used electroencephalography to measure the N2pc during a dot-probe task in which images of faces with emotional or neutral expressions competed for attention. Undergraduates (N = 102) completed the task and self-report measures of social anxiety and depression. Hierarchical linear regressions examined the hypotheses that social anxiety would be associated with attentional biases toward both angry and disgust faces and that depression would be associated with biases away from happy faces and toward sad faces. Social anxiety was associated with a more negative N2pc for (i.e. greater bias toward) happy faces (β = -.32, p \u3c .01) when holding depression constant. Depression was only marginally associated with bias toward sad faces (β = -.20, p = .09), given average social anxiety, and the interaction of depression and social anxiety marginally predicted less bias toward sad faces (β = .21, p = .08). The social anxiety bias toward happy faces supports the fear of positive evaluation theory (Weeks et al., 2008). Individuals with social anxiety may rapidly attend to positive evaluation because it signals being pulled further into an anxious situation. The depression bias toward sad faces was marginal but provides some support for the cognitive perspective that attentional vigilance for depressive content influences negative thoughts and mood. This research informs interventions such as attentional bias modification and cognitive-behavioral therapy.https://digitalcommons.odu.edu/gradposters2022_sciences/1006/thumbnail.jp

    Ground-Based Centimeter, Millimeter, and Submillimeter Observations of Recent Comets

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    Comets provide important clues to the physical and chemical processes that occurred during the formation and early evolution of the Solar System, and could also have been important for initiating prebiotic chemistry on the early Earth [I]. Comets are comprised of molecular ices, that may be pristine interstellar remnants of Solar System formation, along with high-temperature crystalline silicate dust that is indicative of a more thermally varied history in the protosolar nebula [2]. Comparing abundances of cometary parent volatiles, and isotopic fractionation ratios, to those found in the interstellar medium, in disks around young stars, and between cometary families, is vital to understanding planetary system formation and the processing history experienced by organic matter in the so-called interstellar-comet connection [3]. In the classical picture, the long-period comets probably formed in the nebular disk across the giant planet formation region (5-40 AU) with the majority of them originating from the Uranus-Neptune region. They were subsequently scattered out to the Oort Cloud (OC) by Jupiter. The short-period comets (also known as ecliptic or Jupiter Family Comets - JFC) reside mainly in the Edgeworth-Kuiper belt where they were formed. Given the gradient in physical conditions expected across this region of the nebula, chemical diversity in this comet population is to be expected [4,5]. We have conducted observations of comets I 03P/Hartley 2 (JFC) and C/2009 PI (Garradd) (OC), at primarily millimeter and submillimeter wavelengths, to determine important cosmogonic quantities, such as the ortho:para ratio and isotope ratios, as well as probe the origin of cometary organics and if they vary between the two dynamic reservoirs

    Ground-Based Centimeter, Millimeter, and Submillimeter Observations of Comet 103P/Hartley 2

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    Comets provide important clues to the physical and chemical processes that occurred during the formation and early evolution of the Solar System, and could also have been important for initiating prebiotic chemistry on the early Earth [1]. Comets are comprised of molecular ices, that may be pristine interstellar remnants of Solar System formation, along with high-temperature crystalline silicate dust that is indicative of a more thermally varied history in the protosolar nebula [2]. Comparing abundances of cometary parent volatiles, and isotopic fractionation ratios, to those found in the interstellar medium, in disks around young stars, and between cometary families, is vital to understanding planetary system formation and the processing history experienced by organic matter in the so-called interstellar-comet connection [3]. We have conducted observations, at primarily millimeter and submillimeter wavelengths, where molecular emission is easily resolved, towards comets to determine important cosmogonic quantities, such as the ortl1o:pal'a ratio and isotope ratios, as well as probe the origin of cometary organics. Comets provide important clues to the processes that occurred during the formation and early evolution of the Solar System. Past observations, as well as laboratory measurements of cometary material obtained from Stardust, have shown that comets appear to contain a mixture of the products from both interstellar and nebular chemistries. A major observational challenge in cometary science is to quantify the extent to which chemical compounds can be linked to either reservoir

    On the nature of the enigmatic object IRAS 19312+1950: A rare phase of massive star formation?

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    IRAS 19312+1950 is a peculiar object that has eluded firm characterization since its discovery, with combined maser properties similar to an evolved star and a young stellar object (YSO). To help determine its true nature, we obtained infrared spectra of IRAS 19312+1950 in the range 5-550 μ\mum using the Herschel and Spitzer space observatories. The Herschel PACS maps exhibit a compact, slightly asymmetric continuum source at 170 μ\mum, indicative of a large, dusty circumstellar envelope. The far-IR CO emission line spectrum reveals two gas temperature components: ≈0.22M⊙\approx0.22M_{\odot} of material at 280±18280\pm18 K, and ≈1.6M⊙\approx1.6M_{\odot} of material at 157±3157\pm3 K. The OI 63 μ\mum line is detected on-source but no significant emission from atomic ions was found. The HIFI observations display shocked, high-velocity gas with outflow speeds up to 90 km s−1^{-1} along the line of sight. From Spitzer spectroscopy, we identify ice absorption bands due to H2_2O at 5.8 μ\mum and CO2_2 at 15 μ\mum. The spectral energy distribution is consistent with a massive, luminous (∼2×104L⊙\sim2\times10^4L_{\odot}) central source surrounded by a dense, warm circumstellar disk and envelope of total mass ∼500\sim500-700M⊙700M_{\odot}, with large bipolar outflow cavities. The combination of distinctive far-IR spectral features suggest that IRAS 19312+1950 should be classified as an accreting high-mass YSO rather than an evolved star. In light of this reclassification, IRAS 19312+1950 becomes only the 5th high-mass protostar known to exhibit SiO maser activity, and demonstrates that 18 cm OH maser line ratios may not be reliable observational discriminators between evolved stars and YSOs.Comment: 16 pages. Accepted for publication in Ap

    JWST observations of stellar occultations by solar system bodies and rings

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    In this paper we investigate the opportunities provided by the James Webb Space Telescope (JWST) for significant scientific advances in the study of solar system bodies and rings using stellar occultations. The strengths and weaknesses of the stellar occultation technique are evaluated in light of JWST's unique capabilities. We identify several possible JWST occultation events by minor bodies and rings, and evaluate their potential scientific value. These predictions depend critically on accurate a priori knowledge of the orbit of JWST near the Sun-Earth Lagrange-point 2 (L2). We also explore the possibility of serendipitous stellar occultations by very small minor bodies as a by-product of other JWST observing programs. Finally, to optimize the potential scientific return of stellar occultation observations, we identify several characteristics of JWST's orbit and instrumentation that should be taken into account during JWST's development.Comment: This paper is one of a series for a special issue on Solar System observations with JWST in PASP. Accepted 2-Oct-2015. Preprint 30 pages, 5 tables, 8 figure

    When Worlds Collide: Boundary Management of Adolescent and Young Adult Childhood Cancer Survivors and Caregivers

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    Adolescent and young adult childhood cancer survivors experience health complications, late or long-term biomedical complications, as well as economic and psychosocial challenges that can have a lifelong impact on their quality-of-life. As childhood cancer survivors transition into adulthood, they must learn to balance their identity development with demands of everyday life and the near- and long-term consequences of their cancer experience, all of which have implications for the ways they use existing technologies and the design of novel technologies. In this study, we interviewed 24 childhood cancer survivors and six caregivers about their cancer survivorship experiences. The results of our analysis indicate that the challenges of transitioning to adulthood as a cancer survivor necessitate the development and management of multiple societal, relational, and personal boundaries, processes that social computing technologies can help or hinder. This paper contributes to the empirical understanding of adolescent and young adult cancer survivors’ social experiences. We further contribute sociotechnical design provocations for researchers, designers, and community members to support survivors

    The Distribution, Excitation and Formation of Cometary Molecules: Methanol, Methyl Cyanide and Ethylene Glycol

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    We present an interferometric and single dish study of small organic species toward Comets C/1995 O1 (Hale-Bopp) and C/2002 T7 (LINEAR) using the BIMA interferometer at 3 mm and the ARO 12m telescope at 2 mm. For Comet Hale-Bopp, both the single-dish and interferometer observations of CH3OH indicate an excitation temperature of 105+/-5 K and an average production rate ratio Q(CH3OH)/Q(H2O)~1.3% at ~1 AU. Additionally, the aperture synthesis observations of CH3OH suggest a distribution well described by a spherical outflow and no evidence of significant extended emission. Single-dish observations of CH3CN in Comet Hale-Bopp indicate an excitation temperature of 200+/-10 K and a production rate ratio of Q(CH3CN)/Q(H2O)~0.017% at ~1 AU. The non-detection of a previously claimed transition of cometary (CH2OH)2 toward Comet Hale-Bopp with the 12m telescope indicates a compact distribution of emission, D<9'' (<8500 km). For the single-dish observations of Comet T7 LINEAR, we find an excitation temperature of CH3OH of 35+/-5 K and a CH3OH production rate ratio of Q(CH3OH)/Q(H2O)~1.5% at ~0.3 AU. Our data support current chemical models that CH3OH, CH3CN and (CH2OH)2 are parent nuclear species distributed into the coma via direct sublimation off cometary ices from the nucleus with no evidence of significant production in the outer coma.Comment: accepted for publication in Ap
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