7,043 research outputs found
Micromechanics of cyclic deformation in SSME turbopump blade materials
Current and candidate Space Shuttle Main Engine (SSME) turbopump blade materials are anisotropic, both in their elastic and plastic response. The major objective is to characterize the plastic deformation behavior of a typical single crystal nickel-base superalloy, PWA 1480, and to use this information to help guide the development of anisotropic constitutive models
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Information Structures to Secure Control of Rigid Formations with Leader-Follower Structure
This paper is concerned with rigid formations of mobile autonomous agents using a leader-follower structure. A formation is a group of agents moving in real 2- or 3- dimensional space. A formation is called rigid if the distance between each pair of agents does not change over time under ideal conditions. Sensing/communication links between agents are used to maintain a rigid formation. Two agents connected by a sensing/communication link are called neighbors. There are two types of neighbor relations in rigid formations. In the first type, the neighbor relation is symmetric. In the second type, the neighbor relation is asymmetric. Rigid formations with a leader-follower structure have the asymmetric neighbor relation. A framework to analyze rigid formations with symmetric neighbor relations is given in our previous work. This paper suggests an approach to analyze rigid formations that have a leader-follower structure
Laboratory measurements of electrostatic solitary structures generated by electron beam injection
Electrostatic solitary structures are generated by injection of a
suprathermal electron beam parallel to the magnetic field in a laboratory
plasma. Electric microprobes with tips smaller than the Debye length
() enabled the measurement of positive potential pulses with
half-widths 4 to 25 and velocities 1 to 3 times the background
electron thermal speed. Nonlinear wave packets of similar velocities and scales
are also observed, indicating that the two descend from the same mode which is
consistent with the electrostatic whistler mode and result from an instability
likely to be driven by field-aligned currents.Comment: 5 pages, 4 figures
http://link.aps.org/doi/10.1103/PhysRevLett.105.11500
Erenumab in chronic migraine: Patient-reported outcomes in a randomized double-blind study.
OBJECTIVE: To determine the effect of erenumab, a human monoclonal antibody targeting the calcitonin gene-related peptide receptor, on health-related quality of life (HRQoL), headache impact, and disability in patients with chronic migraine (CM).
METHODS: In this double-blind, placebo-controlled study, 667 adults with CM were randomized (3:2:2) to placebo or erenumab (70 or 140 mg monthly). Exploratory endpoints included migraine-specific HRQoL (Migraine-Specific Quality-of-Life Questionnaire [MSQ]), headache impact (Headache Impact Test-6 [HIT-6]), migraine-related disability (Migraine Disability Assessment [MIDAS] test), and pain interference (Patient-Reported Outcomes Measurement Information System [PROMIS] Pain Interference Scale short form 6b).
RESULTS: Improvements were observed for all endpoints in both erenumab groups at month 3, with greater changes relative to placebo observed at month 1 for many outcomes. All 3 MSQ domains were improved from baseline with treatment differences for both doses exceeding minimally important differences established for MSQ-role function-restrictive (≥3.2) and MSQ-emotional functioning (≥7.5) and for MSQ-role function-preventive (≥4.5) for erenumab 140 mg. Changes from baseline in HIT-6 scores at month 3 were -5.6 for both doses vs -3.1 for placebo. MIDAS scores at month 3 improved by -19.4 days for 70 mg and -19.8 days for 140 mg vs -7.5 days for placebo. Individual-level minimally important difference was achieved by larger proportions of erenumab-treated participants than placebo for all MSQ domains and HIT-6. Lower proportions of erenumab-treated participants had MIDAS scores of severe (≥21) or very severe (≥41) or PROMIS scores ≥60 at month 3.
CONCLUSIONS: Erenumab-treated patients with CM experienced clinically relevant improvements across a broad range of patient-reported outcomes.
CLINICALTRIALSGOV IDENTIFIER: NCT02066415.
CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with CM, erenumab treatment improves HRQoL, headache impact, and disability
Intrinsic Absorption Lines in Seyfert 1 Galaxies. I. Ultraviolet Spectra from the Hubble Space Telescope
We present a study of the intrinsic absorption lines in the ultraviolet
spectra of Seyfert 1 galaxies. We find that the fraction of Seyfert 1 galaxies
that show absorption associated with their active nuclei is more than one-half
(10/17), which is much higher than previous estimates (3 - 10%) . There is a
one-to-one correspondence between Seyferts that show intrinsic UV absorption
and X-ray ``warm absorbers''. The intrinsic UV absorption is generally
characterized by high ionization: C IV and N V are seen in all 10 Seyferts with
detected absorption (in addition to Ly-alpha), whereas Si IV is present in only
four of these Seyferts, and Mg II absorption is only detected in NGC 4151. The
absorption lines are blueshifted (or in a few cases at rest) with respect to
the narrow emission lines, indicating that the absorbing gas is undergoing net
radial outflow. At high resolution, the absorption often splits into distinct
kinematic components that show a wide range in widths (20 - 400 km/s FWHM),
indicating macroscopic motions (e.g., radial velocity subcomponents or
turbulence) within a component. The strong absorption components have cores
that are much deeper than the continuum flux levels, indicating that the
regions responsible for these components lie completely outside of the broad
emission-line regions. The covering factor of the absorbing gas in the line of
sight, relative to the total underlying emission, is C > 0.86, on average. The
global covering factor, which is the fraction of emission intercepted by the
absorber averaged over all lines of sight, is C > 0.5.Comment: 56 pages, Latex, includes 4 figures (encapsulated postscript), Fig. 1
has 2 parts and Fig. 2 has 3 parts, to appear in the Astrophysical Journa
The 3rd IBIS/ISGRI soft gamma-ray survey catalog
In this paper we report on the third soft gamma-ray source catalog obtained
with the IBIS/ISGRI gamma-ray imager on board the INTEGRAL satellite. The
scientific dataset is based on more than 40 Ms of high quality observations
performed during the first three and a half years of Core Program and public
IBIS/ISGRI observations. Compared to previous IBIS/ISGRI surveys, this catalog
includes a substantially increased coverage of extragalactic fields, and
comprises more than 400 high-energy sources detected in the energy range 17-100
keV, including both transients and faint persistent objects which can only be
revealed with longer exposure times.Comment: Accepted for publication in ApJ Suppl.; 11 pages; 4 figures Minor
changes to conten
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uC: Ubiquitous Collaboration Platform for Multimodal Team Interaction Support
A human-centered computing platform that improves teamwork and transforms the “human- computer interaction experience” for distributed teams is presented. This Ubiquitous Collaboration, or uC (“you see”), platform\u27s objective is to transform distributed teamwork (i.e., work occurring when teams of workers and learners are geographically dispersed and often interacting at different times). It achieves this goal through a multimodal team interaction interface realized through a reconfigurable open architecture. The approach taken is to integrate: (1) an intuitive speech- and video-centric multi-modal interface to augment more conventional methods (e.g., mouse, stylus and touch), (2) an open and reconfigurable architecture supporting information gathering, and (3) a machine intelligent approach to analysis and management of heterogeneous live and stored sensor data to support collaboration. The system will transform how teams of people interact with computers by drawing on both the virtual and physical environment
Unveiling the nature of INTEGRAL objects through optical spectroscopy. IV. A study of six new hard X-ray sources
We present further results from our ongoing optical spectrophotometric
campaign at the Astronomical Observatory of Bologna in Loiano (Italy) on
unidentified hard X-ray sources detected by INTEGRAL. We observed
spectroscopically the putative optical counterparts of the INTEGRAL sources IGR
J00234+6141, IGR J01583+6713, IGR J06074+2205, IGR J13091+1137 and IGR
J20286+2544. We find that the first two are Galactic objects, namely a
Cataclysmic Variable at a distance of about 300 pc and a Be/X transient
High-Mass X-ray Binary (HMXB) located at about 6.4 kpc, respectively, whereas
the last one is identified with MCG +04-48-002, a Starburst/HII galaxy at
redshift z = 0.013 hiding a Seyfert 2 nucleus. We identify IGR J13091+1137 as
the (likely Seyfert 2 type) active nucleus of galaxy NGC 4992, which we
classify as an X-ray Bright, Optically Normal Galaxy; this is the first example
of this type of object to be detected by INTEGRAL, and one of the closest of
this class. We moreover confirm the possible Be/X nature of IGR J06074+2205,
and we estimate it to be at a distance of about 1 kpc. We also reexamine the
spectrum of the z = 0.087 elliptical radio galaxy PKS 0352-686, the possible
counterpart of the INTEGRAL source IGR J03532-6829, and we find that it is a BL
Lac. Physical parameters for these sources are also evaluated by discussing our
findings in the context of the available multiwavelength information. These
identifications further stress the importance of INTEGRAL in the study of the
hard X-ray spectrum of Active Galactic Nuclei, HMXBs and Cataclysmic Variables.Comment: 11 pages, 3 figures, 2 tables, accepted for publication on A&A, main
journal. The quality of Fig. 1 was degraded to fit the arXiv uploads size
limits. Revised version matches the A&A corrected proof
Scientific approaches to the deposit insurance scheme classification
У статті систематизовано існуючі підходи до класифікації систем гарантування вкладів, визначено сутність, переваги та недоліки різних видів систем гарантування вкладів. Досліджено місце вітчизняної системи гарантування вкладів у загальній класифікаціїThe article defines the existing approaches to the deposit insurance scheme classification, the essence, advantages and disadvantages of various types of deposit insurance schemes. It is also given the place of national deposit guarantee system in the general classificatio
IGR J18483-0311: an accreting X-ray pulsar observed by INTEGRAL
IGR J18483-0311 is a poorly known transient hard X-ray source discovered by
INTEGRAL during observations of the Galactic Center region performed between
23--28 April 2003. Aims: To detect new outbursts from IGR J18483-0311 using
INTEGRAL and archival Swift XRT observations and finally to characterize the
nature of this source using the optical/near-infrared (NIR) information
available through catalogue searches. Results: We report on 5 newly discovered
outbursts from IGR J18483-0311 detected by INTEGRAL.For two of them it was
possible to constrain a duration of the order of a few days. The strongest
outburst reached a peak flux of 120 mCrab (20--100 keV): its broad band
JEM--X/ISGRI spectrum (3--50 keV) is best fitted by an absorbed cutoff power
law with photon index=1.4+/-0.3, cutoff energy of ~22 keV and Nh ~9x10^22
cm^-2. Timing analysis of INTEGRAL data allowed us to identify periodicities of
18.52 days and 21.0526 seconds which are likely the orbital period of the
system and the spin period of the X-ray pulsar respectively. Swift XRT
observations of IGR J184830311 provided a very accurate source position
which strongly indicates a highly reddened star in the USNO--B1.0 and 2MASS
catalogues as its possible optical/NIR counterpart. Conclusions: The X-ray
spectral shape, the periods of 18.52 days and 21.0526 seconds, the high
intrinsic absorption, the location in the direction of the Scutum spiral arm
and the highly reddened optical object as possible counterpart, all favour the
hypothesis that IGR J18483-0311 is a HMXB with a neutron star as compact
companion. The system is most likely a Be X-ray binary, but a Supergiant Fast
X-ray Transient nature can not be entirely excluded.Comment: accepted for publication in A&A, 10 pages, 17 figures, 4 table
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