3,951 research outputs found

    Investigation of the fiber reinforcement of a cobalt base alloy for application at elevated temperature

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    Technique developed for incorporating alumina and silicon carbide fibers in cobalt base alloy for application at high temperature

    A global magnetic anomaly map

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    A subset of POGO satellite magnetometer data has been formed that is suitable for analysis of crustal magnetic anomalies. Using a thirteenth order field model, fit to these data, magnetic residuals have been calculated over the world to latitude limits of plus 50 deg. These residuals averaged over one degree latitude-longitude blocks represent a detailed global magnetic anomaly map derived solely from satellite data. Preliminary analysis of the map indicates that the anomalies are real and of geological origin

    Improved definition of crustal magnetic anomalies for MAGSAT data

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    The routine correction of MAGSAT vector magnetometer data for external field effects such as the ring current and the daily variation by filtering long wavelength harmonics from the data is described. Separation of fields due to low altitude sources from those caused by high altitude sources is affected by means of dual harmonic expansions in the solution of Dirichlet's problem. This regression/harmonic filter procedure is applied on an orbit by orbit basis, and initial tests on MAGSAT data from orbit 1176 show reduction in external field residuals by 24.33 nT RMS in the horizontal component, and 10.95 nT RMS in the radial component

    The Priming Function of In-car Audio Instruction

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    Studies to date have focused on the priming power of visual road signs, but not the priming potential of audio road scene instruction. Here, the relative priming power of visual, audio and multisensory road scene instructions were assessed. In a lab-based study, participants responded to target road scene turns following visual, audio or multisensory road turn primes which were congruent or incongruent to the primes in direction, or control primes. All types of instruction (visual, audio, multisensory) were successful in priming responses to a road scene. Responses to multisensory-primed targets (both audio and visual) were faster than responses to either audio or visual primes alone. Incongruent audio primes did not affect performance negatively in the manner of incongruent visual or multisensory primes. Results suggest that audio instructions have the potential to prime drivers to respond quickly and safely to their road environment. Peak performance will be observed if audio and visual road instruction primes can be timed to co-occur

    Inner Molecular Rings in Barred Galaxies: BIMA SONG CO Observations

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    Although inner star-forming rings are common in optical images of barred spiral galaxies, observational evidence for the accompanying molecular gas has been scarce. In this paper we present images of molecular inner rings, traced using the CO (1-0) emission line, from the Berkeley-Illinois-Maryland-Association Survey of Nearby Galaxies (BIMA SONG). We detect inner ring CO emission from all five SONG barred galaxies classified as inner ring (type (r)). We also examine the seven SONG barred galaxies classified as inner spiral (type (s)); in one of these, NGC 3627, we find morphological and kinematic evidence for a molecular inner ring. Inner ring galaxies have been classified as such based on optical images, which emphasize recent star formation. We consider the possibility that there may exist inner rings in which star formation efficiency is not enhanced. However, we find that in NGC 3627 the inner ring star formation efficiency is enhanced relative to most other regions in that galaxy. We note that the SONG (r) galaxies have a paucity of CO and H alpha emission interior to the inner ring (except near the nucleus), while NGC 3627 has relatively bright bar CO and H alpha emission; we suggest that galaxies with inner rings such as NGC 3627 may be misclassified if there are significant amounts of gas and star formation in the bar.Comment: To be published in the Astrophysical Journal, July 2002 A version of the paper with full resolution figures is available at: http://www.astro.umd.edu/~mregan/ms.ps.g

    A Connection between Star Formation in Nuclear Rings and their Host Galaxies

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    We present results from a photometric H-alpha survey of 22 nuclear rings, aiming to provide insight into their star formation properties, including age distribution, dynamical timescales, star formation rates, and galactic bar influence. We find a clear relationship between the position angles and ellipticities of the rings and those of their host galaxies, which indicates the rings are in the same plane as the disk and circular. We use population synthesis models to estimate ages of each H-alpha emitting HII region, which range from 1 Myr to 10 Myrs throughout the rings. We find that approximately half of the rings contain azimuthal age gradients that encompass at least 25% of the ring, although there is no apparent relationship between the presence or absence of age gradients and the morphology of the rings or their host galaxies. NGC1343, NGC1530, and NGC4321 show clear bipolar age gradients, where the youngest HII regions are located near the two contact points of the bar and ring. We speculate in these cases that the gradients are related to an increased mass inflow rate and/or an overall higher gas density in the ring, which would allow for massive star formation to occur on short timescales, after which the galactic rotation would transport the HII regions around the ring as they age. Two-thirds of the barred galaxies show correlation between the locations of the youngest HII region(s) in the ring and the location of the contact points, which is consistent with predictions from numerical modeling.Comment: 23 pages, 10 figures (7 color), 23 tables, accepted for publication in ApJS (Feb 08); NASA-GSFC, IAC, University of Maryland, STSc

    Patient Perceptions of Trauma-Focused Telemental Health Services Using the Telehealth Satisfaction Questionnaire (TSQ)

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    Telehealth services can address many barriers to traditional office-based mental health services. Few studies have assessed youth and caregiver perceptions of and satisfaction with trauma-focused interventions delivered via telemental health. The current study presents data collected using the Telehealth Satisfaction Questionnaire (TSQ), which was developed to measure child and caregiver satisfaction with services, comfort with the telehealth equipment, and barriers to traditional office-based services. Thirteen clinicians delivered home- and school-based Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) via videoconferencing on tablets and computers to 60 child patients (71.7% Latinx, 18.3% Black, and 10.0% non-Hispanic White). Patients and caregivers completed the TSQ at treatment discharge via telephone, videoconferencing, or in-person interviews. There was a high level of satisfaction among patients and caregivers receiving TF-CBT via telemental health. Furthermore, most youth and caregivers felt comfortable using the telehealth equipment from the outset of therapy, and all participants who were not initially comfortable using the equipment reported feeling more comfortable over time. The most common barriers to traditional office-based services were caregiver work schedule (57.7%), distance to mental health clinic (55.8%), and lack of transportation (44.2%). Patients and caregivers expressed a preference for telemental health services if given the option between receiving therapy via videoconferencing versus going to an office-based clinic. Findings indicated telemental health treatment addressed barriers that would have otherwise prevented families from accessing office-based services. The Telehealth Satisfaction Questionnaire can be used to help clinics and providers assess patient and caregiver satisfaction with telehealth services in various settings

    Tetrahedral Symmetry in Ground- and Low-Lying States of Exotic A ~ 110 Nuclei

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    Recent theoretical calculations predict a possible existence of nuclei with tetrahedral symmetry: more precisely, the mean-field hamiltonians of such nuclei are symmetric with respect to double point-group Td. In this paper, we focus on the neutron-rich Zirconium isotopes as an example and present realistic mean-field calculations which predict tetrahedral ground-state configurations in 108,110Zr and low-lying excited states of tetrahedral symmetry in a number of N > 66 isotopes. The motivations for focusing on these nuclei, as well as a discussion of the possible experimental signatures of tetrahedral symmetry are also presented.Comment: Accepted in Phys. Rev. C - Rapid Communication
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