4,213 research outputs found
Evaluation of the Beam Coupling Impedance of New Beam Screen Designs for the LHC Injection Kicker Magnets
During the 2011 run of the LHC there was a significant measured temperature
increase in the LHC Injection Kicker Magnets (MKI) during operation with 50ns
bunch spacing. This was due to increased beam-induced heating of the magnet due
to beam impedance. Due to concerns about future heating with the increased
total intensity to nominal and ultimate luminosities a review of the impedance
reduction techniques within the magnet was required. A number of new beam
screen designs are proposed and their impedance evaluated. Heating estimates
are also given with a particular attention paid to future intensity upgrades to
ultimate parameters
Coaxial Wire Measurements of Ferrite Kicker Magnets
Fast kicker magnets are used to inject beam into and eject beam out of the
CERN accelerator rings. These kickers are generally transmission line type
magnets with a rectangular shaped aperture through which the beam passes.
Unless special precautions are taken the impedance of the yoke can provoke
significant beam induced heating, especially for high intensities. In addition
the impedance may contribute to beam instabilities. The results of longitudinal
and transverse impedance measurements, for various kicker magnets, are
presented and compared with analytical calculations: in addition predictions
from a numerical analysis are discussed
Concordance between Sources of Morbidity Reports: Self-Reports and Medical Records
As part of a 10-year follow-up study of morbidity following spouse bereavement, concordance between subject reports of their illness experience and that given by their doctorsâ and other medical records has been assessed. Enumeration from medical records involved extensive and careful perusal of general practitioner, specialist, and hospital records while subject reports were aided by a structured questionnaire which helped to prompt subjectsâ memories. The findings showed generally poor concordance between these two sources of morbidity data. Overall only 22% of disease events were found in both sources: of the diseases that did not match 65% were from the record source and 35% were from the self-report source. Despite finding that concordance rates varied with some subject and disease factors, concordance was always less than might be expected to occur by random chance (the throw of a coin). These findings have serious implications for epidemiological and pharmacoeconomic research involving morbidity history as they suggest that neither the subject nor their medical record can generally be assumed to provide a complete enumeration of morbidity burden. Indeed, irrespective of the significant factors under consideration, the maximum concordance reached in this study was 45.7%
Spacing of Connections in Compression Flanges of Built-up Cold-formed Steel Beams
Built-up cold-formed steel sections may offer greater economy in building construction. Typical built-up sections are cellular decks or door and window header beams. A research project was initiated to determine if the current spacing criteria outlined in Section D1.2 of the AISI Specification accurately predicted the capacity of built-up sections with the cover plate in compression. This study showed that criteria No.2 of the AISI Design Specification spacing criteria is restrictive when applied to built-up cross sections in bending. All test sections continued to carry additional load after the cover plate buckled. The tests showed that as the spacing of connectors increased the moment capacity of the section decreased. An analytical procedure was developed to compute the nominal moment capacity for a range of connector spacings
Spacing of connections in compression elements for cold-formed steel members (beams)
PREFACE The spacing of connectors in compression elements of built-up flexural members was evaluated both experimentally and analytically at the University ofMissouri-Rolla (UMR) under the sponsorship of the American Iron and Steel Institute. A computational model was developed for determining the bending capacity of single-fluted sections with cover plates that do not have edge stiffeners. The results of the investigation are presented and recommendations are made for design of single-flute cross sections having cover plates without edge stiffeners. Previous research developments by Yener, at Purdue University, and Luttrell, at the University of West Virginia, were compared to the UMR experimental data, which consisted of 83 single flute built-up hat sections with and without edge stiffened cover plates. All hat sections were tested as simple span beams with cover plates in compression. The buckling behavior of edge stiffened cover plates and cover plates without edge stiffeners was investigated and discussed herein. The effective length factor and plate buckling coefficient were determined from the test results. A discussion of the correlation between the UMR experimental findings and the work of both Luttrell and Yener is presented. The UMR research validates the AISI Design Specification spacing criteria (Section D1.2) which restricts spacing to a value that will prevent any separation of the cover plate from the hat section between the connectors. This provision, however, is very conservative when applied to a section in bending because it yields very small connector spacings. The spacing of the connectors may be increased beyond that required by Section D1.2 which results in a reduction of strength. Tests have indicated that the capacity of the hat section is not diminished due to the onset of plate buckling in the cover plate. The hat section will continue to carry additional load because of the post-buckling strength provided by the cover plate. This report is based on a thesis submitted to the Faculty of the Graduate School of the University ofMissouri-Rolla in partial fulfillment of the requirements for the degree of Masters of Science in Civil Engineering. Technical guidance for this investigation was provided by the American Iron and Steel Institute\u27s Subcommittee on Flexural Members (J.N. Nunnery, Chairman) and Connections (M.Golovin, Chairman). The Subcommittees\u27 guidance is gratefully acknowledged. Thanks are also extended to H. H. Chen, D. F. Boring and S.P. Bridgewater, AISI staff, for their assistance
User-centered development of a Virtual Research Environment to support collaborative research events
This paper discusses the user-centred development process within the Collaborative Research Events on the Web (CREW) project, funded under the JISC Virtual Research Environments (VRE) programme. After presenting the project, its aims and the functionality
of the CREW VRE, we focus on the user engagement approach, grounded in the method of co-realisation. We describe the different research settings and requirements of our three embedded user groups and the respective activities conducted so far. Finally we elaborate on
the main challenges of our user engagement approach and end with the projectâs next steps
Inefficiency as the major driver of excess costs in lung resection
BackgroundRisk-adjusted outcomes of surgical care are important for quality and cost assessments. Although cardiac surgery is commonly studied, risk-adjusted analysis of excess costs of lung resection has not been pursued.MethodsWe used 2002 to 2005 National Inpatient Sample of the Healthcare Cost and Utilization Project data to evaluate adverse outcomes and costs in elective lung resections in hospitals with more than 20 cases during that period. Adverse outcomes were inpatient death or excessive risk-adjusted postoperative stay. Logistic models were defined to predict adverse outcomes. Linear models were designed to predict costs. Hospital-specific adverse outcome rates and costs were measured to define performance outliers. Cost-effective reference hospitals were used to define total excess costs.ResultsAmong 12,182 patients at 215 hospitals undergoing lung resection, there were 336 inpatient deaths (2.8%) and 880 live discharges with prolonged risk-adjusted postoperative stay (7.2%). Predictive models for mortality and risk-adjusted postoperative stay had C statistics of 0.773 and 0.643, respectively. There were 11 ineffective hospitals (5.1%) with excessive adverse outcomes (PÂ <Â .005) and 34 inefficient hospitals (15.8%) meeting quality measures but with higher than predicted costs (PÂ <Â .0005). Ineffective hospitals had costs 9978 higher than predicted.ConclusionsInefficiency is the major factor in excess inpatient costs associated with lung resection in this model. Although refinements in databases, including total physician costs and postdischarge adverse event costs, will alter models, excess costs of lung resection appear to be driven by inefficiency, not adverse outcomes
Some remarks on the notions of general covariance and background independence
In the first part of this paper I review some of the difficulties that seem
to obstruct generally valid definitions of "general covariance" and/or
"background independence" The second and more historical part deals with a
rather strange argument that Einstein put forward in his 1913 "Entwurf paper"
with M. Grossmann to discredit scalar theories of gravity in order to promote
general covariance.Comment: 26 pages, 3 figures. Contribution to ``An assessment of current
paradigms in the physics of fundamental interactions'', edited by I.O.
Stamatescu (Springer Verlag, to appear
THE RELATIONSHIP BETWEEN THYROID DYSFUNCTION AND ADVANCED LIPOPROTEIN CHOLESTEROL SUBFRACTIONS IN A CONTEMPORARY SAMPLE OF US ADULTS: THE VERY LARGE DATABASE OF LIPIDS THYROID SUB-STUDY
Anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize.
Tumour resistance to radiotherapy remains a barrier to improving cancer patient outcomes. To overcome radioresistance, certain drugs have been found to sensitize cells to ionizing radiation (IR). In theory, more potent radiosensitizing drugs should increase tumour kill and improve patient outcomes. In practice, clinical utility of potent radiosensitizing drugs is curtailed by off-target side effects. Here we report potent anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize to tumours based on surface receptor expression. While two classes of potent anti-tubulins, auristatins and maytansinoids, indiscriminately radiosensitize tumour cells, conjugating these potent anti-tubulins to anti-ErbB antibodies restrict their radiosensitizing capacity. Of translational significance, we report that a clinically used maytansinoid ADC, ado-trastuzumab emtansine (T-DM1), with IR prolongs tumour control in target expressing HER2+ tumours but not target negative tumours. In contrast to ErbB signal inhibition, our findings establish an alternative therapeutic paradigm for ErbB-based radiosensitization using antibodies to restrict radiosensitizer delivery
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