193 research outputs found

    Simulating eddy current sensor outputs for blade tip timing

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    Blade tip timing is a contactless method used to monitor the vibration of blades in rotating machinery. Blade vibration and clearance are important diagnostic features for condition monitoring, including the detection of blade cracks. Eddy current sensors are a practical choice for blade tip timing and have been used extensively. As the data requirements from the timing measurement become more stringent and the systems become more complicated, including the use of multiple sensors, the ability to fully understand and optimize the measurement system becomes more important. This requires detailed modeling of eddy current sensors in the blade tip timing application; the current approaches often rely on experimental trials. Existing simulations for eddy current sensors have not considered the particular case of a blade rotating past the sensor. Hence, the novel aspect of this article is the development of a detailed quasi-static finite element model of the electro-magnetic field to simulate the integrated measured output of the sensor. This model is demonstrated by simulating the effect of tip clearance, blade geometry, and blade velocity on the output of the eddy current sensor. This allows an understanding of the sources of error in the blade time of arrival estimate and hence insight into the accuracy of the blade vibration measurement

    Broadening our Understanding of Adversarial Growth: The Contribution of Narrative Methods

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    After adversity, individuals sometimes report adversarial growth - positive changes in their identity, relationships, and worldviews. We examined how narrative methods enhanced understanding of adversarial growth compared to standard questionnaires. Participants (N = 411) from college and community samples reported on their well-being, wrote a narrative about a highly challenging experience, and answered questionnaires on adversarial growth. Results showed that adversarial growth coded in narratives was positively associated with widely used self-report questionnaires of adversarial growth. Unexpectedly, narrative growth did not predict incremental validity in well-being outcomes compared to standard questionnaires. We found unique expressions of adversarial growth in a qualitative analysis of the narratives. We discuss the added value of using narratives for the assessment of adversarial growth

    Supervised exercise therapy and revascularization: Single-center experience of intermittent claudication management

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    Guidelines recommend supervised exercise therapy (SET) as first-line treatment for intermittent claudication. However, the use of revascularization is widespread. We addressed the effectiveness of preventing (additional) invasive revascularization after primary SET or revascularization based on lesion and patient characteristics. In this single-center, retrospective, cohort study, 474 patients with intermittent claudication were included. Patients with occlusive disease of the aortoiliac tract and/or common femoral artery (inflow) were primarily considered for revascularization, while patients with more distal disease (outflow) were primarily considered for SET. In total, 232 patients were referred for SET and 242 patients received revascularization. The primary outcome was freedom from (additional) intervention, analyzed by Kaplan–Meier estimates. Secondary outcomes were survival, critical ischemia, freedom from target lesion revascularization (TLR), and an increase in maximum walking distance. In the SET-first strategy, 71% of patients had significant outflow lesions. Freedom from intervention was 0.90 ± 0.02 at 1-year and 0.82 ± 0.03 at 2-year follow-up. In the primary revascularization group, 90% of patients had inflow lesions. Freedom from additional intervention was 0.78 ± 0.03 at 1-year and only 0.65 ± 0.04 at 2-year follow-up, despite freedom from TLR of 0.91 ± 0.02 and 0.85 ± 0.03 at 1- and 2-year follow-up, respectively. In conclusion, SET was effective in preventing invasive treatment for patients with mainly outflow lesions. In contrast, secondary intervention rates following our strategy of primary revascularization for inflow lesions were unexpectedly high. These findings further support the guideline recommendations of SET as first-line treatment for all patients with intermittent claudication irrespective of level of disease

    Efficient concurrent simulation of large networks using various fault models

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    Factors influencing nurse participation in continuing professional development activities: Survey results from the Netherlands

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    Background Professionals are individually responsible for planning and carrying out continuing professional development (CPD) activities, ensuring their relevance to current practice and career development. The key factors that encourage nurses to undertake CPD activities are not yet clear. Several studies have investigated motives of nurses to participate in CPD programmes (“Motives”), the importance they attach to CPD (“Importance”), the conditions they consider necessary for participation (“Conditions”), and their actual participation in CPD activities (“Pursued”). The relationships among these variables, however, have neither been investigated nor reported to date. Objectives The aim of this study is to investigate the nature of the relationships among those factors that influence nurse participation in CPD in the Netherlands. Design An exploratory cross-sectional study was carried out using quantitative data collected with the previously validated Questionnaire Professional Development of Nurses (Q-PDN). Settings and Participants A convenience sample of 5500 registered nurses working at one Dutch university hospital and several general hospitals was addressed. Methods A descriptive study using a survey was undertaken. The questionnaire was completed and returned by 1226 nurses. Correlation analyses were conducted to determine which factors were related to nurses undertaking CPD activities. Structural equation modelling was deployed to determine the relationships among the variables. Results “Conditions” was found to be moderately related to “Motives”, which itself was strongly related to “Importance”, which itself was very strongly related to “CPD activities pursued”. If nurses considered a CPD activity important they were highly likely to pursue it; however, the importance attached to specific CPD activities was influenced by the presence of particular motives, which depended in part on the way CPD conditions were perceived. Conclusions The key factor influencing CPD participation of nurses is how important they deem particular CPD activities; the latter is a function of their CPD motives and of their perceptions that the right conditions for participation are in place. Implications are discussed. Keywords: Continuing professional development, CPD, Nurses, Survey, the Netherlands, Motives for participation in CP
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