5,307 research outputs found
The Advanced Photon Source Injector Test Stand Control System
The Advanced Photon Source (APS) primary and backup injectors consist of two
thermionic-cathode rf guns. These guns are being upgraded to provide improved
performance, to improve ease of maintenance, and to reduce downtime required
for repair or replacement of a failed injector. As part of the process, an
injector test stand is being prepared. This stand is effectively independent of
the APS linac and will allow for complete characterization and validation of an
injector prior to its installation into the APS linac.
A modular control system for the test stand has been developed using standard
APS control solutions with EPICS to deliver a flexible and comprehensive
control system. The modularity of the system will allow both future expansion
of test stand functionality and evaluation of new control techniques and
solutions.Comment: Poster paper (TUAP015) at ICALEPCS 2001, 3 pages, 2 figures, pd
A Modified Linear Integral Resonant Controller for suppressing jump-phenomenon and hysteresis in micro-cantilever beam structures
Credit author statement James MacLean: developed the theory and performed the simulations. Sumeet S. Aphale: supervised the overall research, helped with theoretical development, presentation of results and document formatting.Peer reviewedPostprin
An extreme paucity of second population AGB stars in the normal globular cluster M4
Galactic Globular clusters (GCs) are now known to harbour multiple stellar
populations, which are chemically distinct in many light element abundances. It
is becoming increasingly clear that asymptotic giant branch (AGB) stars in GCs
show different abundance distributions in light elements compared to those in
the red giant branch (RGB) and other phases, skewing toward more primordial,
field-star-like abundances, which we refer to as subpopulation one (SP1). As
part of a larger program targeting giants in GCs, we obtained high-resolution
spectra for a sample of 106 RGB and 15 AGB stars in Messier 4 (NGC 6121) using
the 2dF+HERMES facility on the Anglo-Australian Telescope. In this Letter we
report an extreme paucity of AGB stars with [Na/O] > -0.17 in M4, which
contrasts with the RGB that has abundances up to [Na/O] =0.55. The AGB
abundance distribution is consistent with all AGB stars being from SP1. This
result appears to imply that all subpopulation two stars (SP2; Na-rich, O-poor)
avoid the AGB phase. This is an unexpected result given M4's horizontal branch
morphology -- it does not have an extended blue horizontal branch. This is the
first abundance study to be performed utilising the HERMES spectrograph.Comment: 5 pages, 2 figures, 4 tables (full Table 1 online). Accepted for
publication in MNRAS Letter
Continuous-wave Raman laser pumped within a semiconductor disk laser cavity
A KGd(WO4)(2) Raman laser was pumped within the cavity of a cw diode-pumped InGaAs semiconductor disk laser (SDL). The Raman laser threshold was reached for 5: 6W of absorbed diode pump power, and output power up to 0.8W at 1143nm, with optical conversion efficiency of 7.5% with respect to the absorbed diode pump power, was demonstrated. Tuning the SDL resulted in tuning of the Raman laser output between 1133 and 1157nm
Patient Perspectives on Medication Assisted Therapy in Vermont
Introduction. Medication-Assisted Therapy (MAT) for opioid addiction has dramatically increased in Vermont, supported by a novel statewide system that integrates specialty treatment centers ( Hubs ) with primary care office-based opioid therapy ( Spokes ). In 2010, Vermont had the highest per capita buprenorphine use in the US. Previous studies of patient perspectives of MAT have identified social barriers, rigid program rules, and concerns about withdrawal and relapse as common causes of treatment failure. Our goal was to elicit patient perspectives on barriers and enablers of successful MAT to further inform system refinement.
Methods. An interview guide was developed based on previous literature as well as discussions with program leadership, staff and clinicians, and community stakeholders. Responses were organized using thematic content analysis with consensus across seven interviewers and two analysts. The interviews were conducted with 44 patients enrolled in MAT at two Hub sites in Burlington, VT in October 2016.
Results. The median age of subjects was 34 years, 34% were employed at least part-time, and 72% were female. Half reported a mental health condition and 20% reported chronic pain. Barriers included transportation (25%), lack of stable housing, and stigma (41%). Enablers included feeling supported (82% felt well-supported; 52% felt supported by healthcare professionals). Subjects expressed high confidence in the treatment system and high self-efficacy for sobriety.
Conclusions. Patients in MAT have complex medical, mental health, social, personal, and work lives. A comprehensive system that addresses this wide range of domains is critical to achieving optimal outcomes.https://scholarworks.uvm.edu/comphp_gallery/1245/thumbnail.jp
New proof-of-concept in viral inactivation: virucidal efficacy of 405 nm light against feline calicivirus as a model for norovirus decontamination
The requirement for novel decontamination technologies for use in hospitals is ever present. One such system uses 405 nm visible light to inactivate microorganisms via ROS-generated oxidative damage. Although effective for bacterial and fungal inactivation, little is known about the virucidal effects of 405 nm light. Norovirus (NoV) gastroenteritis outbreaks often occur in the clinical setting, and this study was designed to investigate potential inactivation effects of 405 nm light on the NoV surrogate, feline calicivirus (FCV). FCV was exposed to 405 nm light whilst suspended in minimal and organically-rich media to establish the virucidal efficacy and the effect biologically-relevant material may play in viral susceptibility. Antiviral activity was successfully demonstrated with a 4 Log10 (99.99%) reduction in infectivity when suspended in minimal media evident after a dose of 2.8 kJ cm−2. FCV exposed in artificial faeces, artificial saliva, blood plasma and other organically rich media exhibited an equivalent level of inactivation using between 50–85% less dose of the light, indicating enhanced inactivation when the virus is present in organically-rich biologically-relevant media. Further research in this area could aid in the development of 405 nm light technology for effective NoV decontamination within the hospital environment
Spectroscopy of Sc and ab initio calculations of strengths
The GRIFFIN spectrometer at TRIUMF-ISAC has been used to study excited states
and transitions in Sc following the -decay of Ca.
Branching ratios were determined from the measured -ray intensities,
and angular correlations of rays have been used to firmly assign the
spins of excited states. The presence of an isomeric state that decays by an
transition with a strength of 13.6(7)\,W.u. has been confirmed. We
compare with the first {\it ab initio} calculations of ) strengths in
light and medium-mass nuclei from the valence-space in-medium similarity
renormalization group approach, using consistently derived effective
Hamiltonians and operator. The experimental data are well reproduced for
isoscalar transitions when using bare -factors, but the strength of
isovector transitions are found to be underestimated by an order of
magnitude
Climate Change and Malaria in Canada: A Systems Approach
This article examines the potential for changes in imported and autochthonous malaria incidence in Canada as a consequence of climate change. Drawing on a systems framework, we qualitatively characterize and assess the potential direct and indirect impact of climate change on malaria in Canada within the context of other concurrent ecological and social trends. Competent malaria vectors currently exist in southern Canada, including within this range several major urban centres, and conditions here have historically supported endemic malaria transmission. Climate change will increase the occurrence of temperature conditions suitable for malaria transmission in Canada, which, combined with trends in international travel, immigration, drug resistance, and inexperience in both clinical and laboratory diagnosis, may increase malaria incidence in Canada and permit sporadic autochthonous cases. This conclusion challenges the general assumption of negligible malaria risk in Canada with climate change
- …