5,630 research outputs found
A Type Inference Algorithm for Secure Ambients
We consider a type discipline for the Ambient Calculus that associates ambients with security levels and constrains them to be traversed by or opened in ambients of higher security clearance only. We present a bottom-up algorithm that, given an untyped process , computes a minimal set of constraints on security levels such that all actions during runs of are performed without violating the security level priorities. Such an algorithm appears to be a prerequisite to use type systems to ensure security properties in the web scenario
LLNL's Diagram of Chronological Events and B695 Weekly Inspection Reports
Activities leading to the incident were: (1) RCRA Class 2 Permit Modification granted on July 25, 2007 to install a walk-in fume hood in room 1025; (2) USQ-695-07-148 to do the work approved on 9/17; (3) ducting removed early October done by Facility Personnel under IWS 10331.09; (4) ducting swiped for 'free release' radioactivity only by team 1 personnel on 10/16; (5) all ducting and valves remained in building 695 room 1025 except for one piece delivered to building 391 (MMED shop); (6) material delivered by facility personnel to MMED shope B391 on about 10/19; (7) MMED personnel took a duct piece to B511 shop and removed the flange which went to salvage; (8) MMED personnel took the duct piece back to B391 shop and welded on a cap; (9) RHWM personnel picked up the welded duct from B391 around 10/26 and returned ti to B695 room 1025; and (10) the analysis report receive don 12/3 indicated that beryllium swipes take on 11/16, in B695 room 1025, and on ducting that did not leave the room where personnel worked, were above the release level for beryllium
The Transversity Function and Double Spin Azimuthal Asymmetry in Semi-Inclusive Pion Leptoproduction
We show that the transverse momentum dependent transversity function is
proportional to the longitudinal polarization of a quark in a transversely
polarized proton. This result suggests an alternative, convenient method for
determining transversity, without knowing unusual fragmentation functions. The
method consists of measuring the double spin azimuthal asymmetry in
semi-inclusive pion leptoproduction by a transversely polarized proton target.
The asymmetry, which is twist 3, is estimated to be more than 10% under the
most favorable conditions. The experiment we suggest is feasible at facilities
like DESY and CERN.Comment: extended version; to appear on Int. Jou. Mod. Phys.
Evidence for a resonant cyclotron line in IGR J16493-4348 from the Swift-BAT hard X-ray survey
Resonant absorption cyclotron features are a key diagnostic tool to directly
measure the strength of the magnetic field of accreting neutron stars. However,
typical values for cyclotron features lie in the high-energy part of the
spectrum between 20 keV and 50 keV, where detection is often damped by the low
statistics from single pointed observations. We show that long-term monitoring
campaign performed with Swift-BAT of persistently, but faint, accreting
high-mass X-ray binaries is able to reveal in their spectra the presence of
cyclotron features. We extracted the average Swift-BAT 15-150 keV spectrum from
the 54 months long Swift-BAT survey of the high-mass X-ray source IGR
J16493-4348. To constrain the broadband spectrum we used soft X-ray spectra
from Swift-XRT and Suzaku pointed observations. We model the spectra using a
set of phenomenological models usually adopted to describe the energy spectrum
of accreting high-mass X-ray binaries; irrespective of the models we used, we
found significant improvements in the spectral fits adding to the models a
broad (10 keV width) absorption feature, with best-fitting energy estimate
between 30 and 33 keV, that we interpret as evidence for a resonant cyclotron
absorption feature. We also discuss instrumental issues related to the use of
Swift-BAT for this kind of studies and the statistical method to weight the
confidence level of this detection. Correcting for the gravitational redshift
of a 1.4 M_{\sun} neutron star, the inferred surface magnetic field is Bsurf
3.7 x 10^{12} Gauss. The spectral parameters of IGR J16493-4348 fit well with
empirical correlations observed when the whole sample of high-mass binaries
with detected cyclotron features is considered.Comment: Published in Astronomy & Astrophysics, 2011, 532, A7
X-ray spectral evolution of the extragalactic Z-source, LMC X-2
We present the results obtained by a detailed study of the extragalactic Z
source, LMC X-2, using broad band Suzaku data and a large ( ksec)
data set obtained with the proportional counter array (PCA) onboard RXTE. The
PCA data allows for studying the complete spectral evolution along the
horizontal, normal and flaring branches of the Z-track. Comparison with
previous study show that the details of spectral evolution (like variation of
Comptonizing electron temperature), is similar to that of GX 17+2 but unlike
that of Cyg X-2 and GX 349+2. This suggests that Z sources are heterogeneous
group with perhaps LMC X-2 and GX 17+2 being member of a subclass. However non
monotonic evolution of the Compton y-parameter seems to be generic to all
sources. The broad band {\it Suzaku} data reveals that the additional soft
component of the source modelled as a disk blackbody emission is strongly
preferred over one where it is taken to be a blackbody spectrum. This component
as well as the temperature of seed photons do not vary when source goes into a
flaring mode and the entire variation can be ascribed to the Comptonizing
cloud. The bolometric unabsorbed luminosity of the source is well constrained
to be ergs/sec which if the source is Eddington
limited implies a neutron star mass of 1.6 M. We discuss the
implications of these results.Comment: 9 pages, 8 figures, accepted for the publicatin in MNRA
Adolescentes no consultantes en riesgo: una evaluación a través del MACI.
This study measures and describes characteristics of adolescents' psychological functioning which, at more intense levels, may become developmental or psychopatological disorders. The Millon Adolescent Clinical Inventory (MACI; Millon, 1993) was administered to a group of 561 Chilean adolescents, from 14 to 18 years old, non-consulting and with normal school attainment. In this group, increased scores on the MACI scales identified 150 at-risk adolescents who dis not present evident emotional or behavioral problems. In this group the score's clinical significance were assessed by means of a cluster analysis that found three types of profiles on the basis of the MACI scores
Self-efficacy for coping. Utility of the Cancer behavior inventory (Italian) for use in palliative care
Background: Newer models of palliative and supportive cancer care view the person as an active agent in managing physical and psychosocial challenges. Therefore, personal efficacy is an integral part of this model. Due to the lack of instruments in Italian to assess coping self-efficacy, the present study included the translation and validation of the Italian version of the Cancer Behavior Inventory-Brief (CBI-B/I) and an initial analysis of the utility of self-efficacy for coping in an Italian sample of palliative care patients. Methods: 216 advanced cancer patients who attended palliative care clinics were enrolled. The CBI-B/I was administered along with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), the Mini Mental Adjustment to Cancer Scale (Mini-MAC), the Cancer Concerns Checklist (CCL), and the Hospital Anxiety and Depression Scale (HADS). The Eastern Cooperative Oncology Group Performance Status (ECOG-PS) ratings of functional capacity were completed by physicians. Results: Factor analysis confirmed that the structure of the CBI-B/I was consistent with the English version. Internal consistency reliability and significant correlations with the EORTC QLQ-C30, Mini-MAC, and HADS supported the concurrent validity of the CBI-B/I. Differences in CBI-B/I scores for high versus low levels of the CCL and ECOG-PS supported the clinical utility of the CBI-B/I. Conclusions: The CBI-B/I has strong psychometric properties and represents an important addition to newer model of palliative and supportive care. In order to improve clinical practice, the CBI-B/I could be useful in identifying specific self-efficacy goals for coping in structured psychosocial intervention
Ytterbium disilicate-based glass-ceramic as joining material for ceramic matrix composites
A key aspect of ceramic matrix composites integration is related to a reliable joining technique. An ytterbium disilicate based glass-ceramic material is processed by reactive viscous flow sintering between a barium aluminium borosilicate glass and ytterbium oxide and it is used to join SiC/SiC and C/SiC composites. The joining temperature and the in situ formation of the Yb2Si2O7 is optimised at 1200°C without pressure, on the basis of the sintering and crystallisation mechanisms. The mechanical characterization of SiC/SiC and C/SiC joined with the ytterbium disilicate-based glass-ceramic, tested by single-lap offset at RT, exhibits an apparent shear strength of 35 MPa, similar to their interlaminar shear strength. The proposed system displays self-healing behaviour at 1000 °C and 1150 °C, as demonstrated by the partial and complete sealing of induced cracks by Vickers indentation on its surface at different loads, thus suggesting that it can effectively be used as promising joining material for CMCs
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