216 research outputs found

    A magnetic damper for first mode vibration reduction in multimass flexible rotors

    Get PDF
    Many rotating machines such as compressors, turbines and pumps have long thin shafts with resulting vibration problems, and would benefit from additional damping near the center of the shaft. Magnetic dampers have the potential to be employed in these machines because they can operate in the working fluid environment unlike conventional bearings. An experimental test rig is described which was set up with a long thin shaft and several masses to represent a flexible shaft machine. An active magnetic damper was placed in three locations: near the midspan, near one end disk, and close to the bearing. With typical control parameter settings, the midspan location reduced the first mode vibration 82 percent, the disk location reduced it 75 percent and the bearing location attained a 74 percent reduction. Magnetic damper stiffness and damping values used to obtain these reductions were only a few percent of the bearing stiffness and damping values. A theoretical model of both the rotor and the damper was developed and compared to the measured results. The agreement was good

    High Performance Magnetic Bearings for Aero Applications

    Get PDF
    Several previous annual reports were written and numerous papers published on the topics for this grant. That work is not repeated here in this final report. Only the work completed in the final year of the grant is presented in this final report. This final year effort concentrated on power loss measurements in magnetic bearing rotors. The effect of rotor power losses in magnetic bearings are very important for many applications. In some cases, these losses must be minimized to maximize the length of time the rotating machine can operate on a fixed energy or power supply. Examples include aircraft gas turbine engines, space devices, or energy storage flywheels. In other applications, the heating caused by the magnetic bearing must be removed. Excessive heating can be a significant problem in machines as diverse as large compressors, electric motors, textile spindles, and artificial heart pumps

    Globally aligned photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18.5′N) : release of georeferenced data, mosaic construction, and viewing software

    Get PDF
    Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q12009, doi:10.1029/2008GC002204.We present a georeferenced photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18′N). The photomosaic was generated from digital photographs acquired using the ARGO II seafloor imaging system during the 1996 LUSTRE cruise, which surveyed a ∼1 km2 zone and provided a coverage of ∼20% of the seafloor. The photomosaic has a pixel resolution of 15 mm and encloses the areas with known active hydrothermal venting. The final mosaic is generated after an optimization that includes the automatic detection of the same benthic features across different images (feature-matching), followed by a global alignment of images based on the vehicle navigation. We also provide software to construct mosaics from large sets of images for which georeferencing information exists (location, attitude, and altitude per image), to visualize them, and to extract data. Georeferencing information can be provided by the raw navigation data (collected during the survey) or result from the optimization obtained from image matching. Mosaics based solely on navigation can be readily generated by any user but the optimization and global alignment of the mosaic requires a case-by-case approach for which no universally software is available. The Lucky Strike photomosaics (optimized and navigated-only) are publicly available through the Marine Geoscience Data System (MGDS, http://www.marine-geo.org). The mosaic-generating and viewing software is available through the Computer Vision and Robotics Group Web page at the University of Girona (http://eia.udg.es/∼rafa/mosaicviewer.html).This work has been supported by the EU Marie Curie RTNs MOMARNet (OD, RG, JE, LN, JF, NG) and FREESUBNet (RG, NG, XC), the Spanish Ministry of Science and Innovation (grant CTM2007–64751; RG, JE), CNRS and ANR (grant ANR NT05–3_42212, JE), ICREA (LN), and by the Generalitat de Catalunya (JE, RG). JF has been funded by MICINN under FPI grant BES-2006-12733 and NG has been supported by MICINN under the ‘‘Ramon y Cajal’’ program

    A controlled pilot trial of a nurse-led intervention (Mini-AFTERc) to manage fear of cancer recurrence in patients affected by breast cancer

    Get PDF
    Funding: This pilot trial was funded by the Chief Scientist Office (CSO), which is part ofthe Scottish Government Heath Directorates (reference: HIPS/17/57).Background: Fear of cancer recurrence (FCR) is common in people affected by breast cancer. FCR is associated with increased health service and medication use, anxiety, depression and reduced quality of life. Existing interventions for FCR are time and resource intensive, making implementation in a National Health Service (NHS) setting challenging. To effectively manage FCR in current clinical practice, less intensive FCR interventions are required. Mini-AFTERc is a structured 30-min counselling intervention delivered over the telephone and is designed to normalise moderate FCR levels by targeting unhelpful behaviours and misconceptions about cancer recurrence. This multi-centre non-randomised controlled pilot trial will investigate the feasibility of delivering the Mini-AFTERc intervention, its acceptability and usefulness, in relation to specialist breast cancer nurses (SBCNs) and patients. This protocol describes the rationale, methods and analysis plan for this pilot trial of the Mini-AFTERc intervention in everyday practice. Methods: This study will run in four breast cancer centres in NHS Scotland, two intervention and two control centres. SBCNs at intervention centres will be trained to deliver the Mini-AFTERc intervention. Female patients who have completed primary breast cancer treatment in the previous 6 months will be screened for moderate FCR (FCR4 score: 10‑14). Participants at intervention centres will receive the Mini-AFTERc intervention within 2 weeks of recruitment. SBCNs will audio record the intervention telephone discussions with participants. Fidelity of intervention implementation will be assessed from audio recordings. All participants will complete three separate follow-up questionnaires assessing changes in FCR, anxiety, depression and quality of life over 3 months. Normalisation process theory (NPT) will form the framework for semi-structured interviews with 20% of patients and all SBCNs. Interviews will explore participants’ experience of the study, acceptability and usefulness of the intervention and factors influencing implementation within clinical practice. The ADePT process will be adopted to systematically problem solve and refine the trial design. Discussion: Findings will provide evidence for the potential effectiveness, fidelity, acceptability and practicality of the Mini-AFTERc intervention, and will inform the design and development of a large randomised controlled trial (RCT).Publisher PDFPeer reviewe

    Specialized dynamical properties of promiscuous residues revealed by simulated conformational ensembles

    Get PDF
    The ability to interact with different partners is one of the most important features in proteins. Proteins that bind a large number of partners (hubs) have been often associated with intrinsic disorder. However, many examples exist of hubs with an ordered structure, and evidence of a general mechanism promoting promiscuity in ordered proteins is still elusive. An intriguing hypothesis is that promiscuous binding sites have specific dynamical properties, distinct from the rest of the interface and pre-existing in the protein isolated state. Here, we present the first comprehensive study of the intrinsic dynamics of promiscuous residues in a large protein data set. Different computational methods, from coarse-grained elastic models to geometry-based sampling methods and to full-atom Molecular Dynamics simulations, were used to generate conformational ensembles for the isolated proteins. The flexibility and dynamic correlations of interface residues with a different degree of binding promiscuity were calculated and compared considering side chain and backbone motions, the latter both on a local and on a global scale. The study revealed that (a) promiscuous residues tend to be more flexible than nonpromiscuous ones, (b) this additional flexibility has a higher degree of organization, and (c) evolutionary conservation and binding promiscuity have opposite effects on intrinsic dynamics. Findings on simulated ensembles were also validated on ensembles of experimental structures extracted from the Protein Data Bank (PDB). Additionally, the low occurrence of single nucleotide polymorphisms observed for promiscuous residues indicated a tendency to preserve binding diversity at these positions. A case study on two ubiquitin-like proteins exemplifies how binding promiscuity in evolutionary related proteins can be modulated by the fine-tuning of the interface dynamics. The interplay between promiscuity and flexibility highlighted here can inspire new directions in protein-protein interaction prediction and design methods. © 2013 American Chemical Society

    What is the prevalence of fear of cancer recurrence in cancer survivors and patients? A systematic review and individual participant data meta-analysis

    Get PDF
    This study was supported by the Dutch Cancer Society (KWF) grant number 10936.Objective Care for fear of cancer recurrence (FCR) is considered the most common unmet need among cancer survivors. Yet the prevalence of FCR and predisposing factors remain inconclusive. To support targeted care, we provide a comprehensive overview of the prevalence and severity of FCR among cancer survivors and patients, as measured using the short form of the validated Fear of Cancer Recurrence Inventory (FCRI-SF). We also report on associations between FCR and clinical and demographic characteristics. Methods This is a systematic review and individual participant data (IPD) meta-analysis on the prevalence of FCR. In the review, we included all studies that used the FCRI-SF with adult (≥18 years) cancer survivors and patients. Date of search: 7 February 2020. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool. Results IPD were requested from 87 unique studies and provided for 46 studies comprising 11,226 participants from 13 countries. 9311 respondents were included for the main analyses. On the FCRI-SF (range 0–36), 58.8% of respondents scored ≥13, 45.1% scored ≥16 and 19.2% scored ≥22. FCR decreased with age and women reported more FCR than men. FCR was found across cancer types and continents and for all time periods since cancer diagnosis. Conclusions FCR affects a considerable number of cancer survivors and patients. It is therefore important that healthcare providers discuss this issue with their patients and provide treatment when needed. Further research is needed to investigate how best to prevent and treat FCR and to identify other factors associated with FCR. The protocol was prospectively registered (PROSPERO CRD42020142185).Publisher PDFPeer reviewe

    United States contributions to the Second International Indian Ocean Expedition (US IIOE-2)

    Get PDF
    From the Preface: The purpose of this document is to motivate and coordinate U.S. participation in the Second International Indian Ocean Expedition (IIOE-2) by outlining a core set of research priorities that will accelerate our understanding of geologic, oceanic, and atmospheric processes and their interactions in the Indian Ocean. These research priorities have been developed by the U.S. IIOE-2 Steering Committee based on the outcomes of an interdisciplinary Indian Ocean science workshop held at the Scripps Institution of Oceanography on September 11-13, 2017. The workshop was attended by 70 scientists with expertise spanning climate, atmospheric sciences, and multiple sub-disciplines of oceanography. Workshop participants were largely drawn from U.S. academic institutions and government agencies, with a few experts invited from India, China, and France to provide a broader perspective on international programs and activities and opportunities for collaboration. These research priorities also build upon the previously developed International IIOE-2 Science Plan and Implementation Strategy. Outcomes from the workshop are condensed into five scientific themes: Upwelling, inter-ocean exchanges, monsoon dynamics, inter-basin contrasts, marine geology and the deep ocean. Each theme is identified with priority questions that the U.S. research community would like to address and the measurements that need to be made in the Indian Ocean to address them.We thank the following organizations and programs for financial contributions, support and endorsement: the U.S. National Oceanic and Atmospheric Administration; the U.S. Ocean Carbon and Biogeochemistry program funded by the National Science Foundation and the National Aeronautics and Space Administration; the NASA Physical Oceanography Program; Scripps Institution of Oceanography; and the Indo-US Science and Technology Forum

    Additional psychometric data for the Spanish Modified Dental Anxiety Scale, and psychometric data for a Spanish version of the Revised Dental Beliefs Survey

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Hispanics comprise the largest ethnic minority group in the United States. Previous work with the Spanish Modified Dental Anxiety Scale (MDAS) yielded good validity, but lower test-retest reliability. We report the performance of the Spanish MDAS in a new sample, as well as the performance of the Spanish Revised Dental Beliefs Survey (R-DBS).</p> <p>Methods</p> <p>One hundred sixty two Spanish-speaking adults attending Spanish-language church services or an Hispanic cultural festival completed questionnaires containing the Spanish MDAS, Spanish R-DBS, and dental attendance questions, and underwent a brief oral examination. Church attendees completed the questionnaire a second time, for test-retest purposes.</p> <p>Results</p> <p>The Spanish MDAS and R-DBS were completed by 156 and 136 adults, respectively. The test-retest reliability of the Spanish MDAS was 0.83 (95% CI = 0.60-0.92). The internal reliability of the Spanish R-DBS was 0.96 (95% CI = 0.94-0.97), and the test-retest reliability was 0.86 (95% CI = 0.64-0.94). The two measures were significantly correlated (Spearman's rho = 0.38, p < 0.001). Participants who do not currently go to a dentist had significantly higher MDAS scores (t = 3.40, df = 106, p = 0.003) as well as significantly higher R-DBS scores (t = 2.21, df = 131, p = 0.029). Participants whose most recent dental visit was for pain or a problem, rather than for a check-up, scored significantly higher on both the MDAS (t = 3.00, df = 106, p = 0.003) and the R-DBS (t = 2.85, df = 92, p = 0.005). Those with high dental fear (MDAS score 19 or greater) were significantly more likely to have severe caries (Chi square = 6.644, df = 2, p = 0.036). Higher scores on the R-DBS were significantly related to having more missing teeth (Spearman's rho = 0.23, p = 0.009).</p> <p>Conclusion</p> <p>In this sample, the test-retest reliability of the Spanish MDAS was higher. The significant relationships between dental attendance and questionnaire scores, as well as the difference in caries severity seen in those with high fear, add to the evidence of this scale's construct validity in Hispanic samples. Our results also provide evidence for the internal and test-retest reliabilities, as well as the construct validity, of the Spanish R-DBS.</p

    Service evaluation of a nurse-led dental anxiety management service for adult patients

    Get PDF
    Objective: Evaluate patients’ and professionals’ experiences of a Nurse-led Dental Anxiety Management Service (NDAMS). Design: Service evaluation. Setting: The NDAMS operates as part of Sheffield Salaried Primary Dental Care Service. Subjects and methods: Questionnaire survey of anxious patients and qualitative interviews with patients and professionals Interventions: Dental nurses delivered low-level psychological interventions as part of an Integrated Care Pathway (ICP) for dental anxiety. Main outcome Measures: Dental anxiety and oral health-related quality of life (OHRQoL) questionnaires were completed by patients prior to and following NDAM. Results: A total of 187 patients were assessed as suitable for NDAM (mean age= 33.7, 77% female) and 33 had completed it at the time of the service evaluation. Of those patients who had completed the intervention significant improvements in dental anxiety and OHRQoL were reported. Professionals highlighted the importance of integrated working, adequate support and training and assessing the suitability of patients for NDAM. Conclusion: ICPs that combine pharmacological and psychological management approaches can help meet the needs of dentally anxious patients, however, early identification of patients most likely to benefit from psychological intervention should be a priority

    Utilization of the ART approach in a group of public oral health operators in South Africa: a 5-year longitudinal study

    Get PDF
    Contains fulltext : 80990.pdf (publisher's version ) (Open Access)BACKGROUND: A significant increase in the proportion of restorations to the number of tooth extractions was reported after the introduction of ART in an academic mobile dental service in South Africa. The changes were ascribed to its less threatening procedure. Based on these findings, ART was subsequently introduced into the public oral health service of Ekurhuleni district in the South African province of Gauteng. This article reports on the 5-year restorative treatment pattern of operators in the Ekurhuleni district, who adopted the ART approach into their daily dental practice. METHODS: Of the 21 trained operators, 11 had placed more than 10% of restorations using ART at year 1 and were evaluated after 5 years. Data, including number of restored and extracted teeth and type of restoration, were drawn from clinical records 4 months before, and up to 5 years after training. The restoration/extraction ratio (REX score) and the proportion of ART restorations to the total number of restorations were calculated. The paired sample t-test and linear regression analysis were applied. RESULTS: The mean percentage of ART restorations after 1 year was 24.0% (SE 7.2) and significantly increased annually to 42.7% (SE 9.2) after 5 years in permanent dentitions. In primary dentitions the mean percentage of ART restorations after 1 year was 80.6% (SE 4.9) and 72.6% (SE 8.8) after 5 years. The mean REX score before ART training was 0.08 (SE 0.03) and 0.07 (SE 0.04) for permanent and primary teeth, respectively and 0.11 (SE 0.03) and 0.17 (SE 0.05) after 5 years. CONCLUSION: Five years after training, ART had been used consistently in this selected group of operators as the predominant restorative treatment used for primary teeth and showed a significant annual increase in permanent teeth. However, this change had not resulted in an increase in the REX score in both dentitions
    • …
    corecore