1,004 research outputs found
A new CAE procedure for railway wheel tribological design
New demands are being imposed on railway wheel wear and reliability to increase the time between wheel reprofiling, improve safety and reduce total wheelset lifecycle costs. In parallel with these requirements, changes in railway vehicle missions are also occurring. These have led to the need to operate rolling stock on track with low as well as high radius curves; increase speeds and axle loads; and contend with a decrease in track quality due to a reduction in maintenance. These changes are leading to an increase in the severity of the wheel/rail contact conditions, which may increase the likelihood of wear or damage occurring.
The aim of this work was to develop a new CAE design methodology to deal with these demands. The model should integrate advanced numerical tools for modelling of railway vehicle dynamics and suitable models to predict wheelset durability under typical operating conditions. This will help in designing wheels for minimum wheel and rail wear; optimising railway vehicle suspensions and wheel profiles; maintenance scheduling and the evaluation of new wheel materials. This work was carried out as part of the project HIPERWheel, funded by the European Community within the Vth Framework Programme
High-precision lateral distortion correction in coherence scanning interferometry using an arbitrary surface
High-precision lateral distortion measurement and correction in coherence scanning interferometry using an arbitrary surface
Lateral optical distortion is present in most optical imaging systems. In coherence scanning interferometry, distortion may cause field-dependent systematic errors in the measurement of surface topography. These errors become critical when high-precision surfaces, e.g. precision optics, are measured. Current calibration and correction methods for distortion require some form of calibration artefact that has a smooth local surface and a grid of high-precision manufactured features. Moreover, to ensure high accuracy and precision of the absolute and relative locations of the features of these artefacts, requires their positions to be determined using a traceable measuring instrument, e.g. a metrological atomic force microscope. Thus, the manufacturing and calibration processes for calibration artefacts are often expensive and complex. In this paper, we demonstrate for the first time the calibration and correction of optical distortion in a coherence scanning interferometer system by using an arbitrary surface that contains some deviations from flat and has some features (possibly just contamination), such that feature detection is possible. By using image processing and a self-calibration technique, a precision of a few nanometres is achieved for the distortion correction. An inexpensive metal surface, e.g. the surface of a coin, or a scratched and defected mirror, which can be easily found in a laboratory or workshop, may be used. The cost of the distortion correction with nanometre level precision is reduced to almost zero if the absolute scale is not required. Although an absolute scale is still needed to make the calibration traceable, the problem of obtaining the traceability is simplified as only a traceable measure of the distance between two arbitrary points is needed. Thus, the total cost of transferring the traceability may also be reduced significantly using the proposed method
The pervasive relevance of COVID-19 within routine paediatric palliative care consultations during the pandemic: a conversation analytic study
Background: The importance of caring for children with complex and serious conditions means that paediatric palliative care must continue during pandemics. The recent pandemic of Coronavirus Disease 2019 (COVID-19) provides a natural experiment to study health communication during pandemic times. However, it is unknown how communication within consultations might change during pandemics. Aim: This study, a sub-study of a larger project, aimed to examine real-world instances of communication in paediatric palliative care consultations prior to and during the COVID-19 pandemic to understand how clinicians and families talk about the pandemic. Design: Paediatric palliative care consultations prior to, during, and immediately following the initial peak of COVID-19 cases in Australia were video recorded and analysed using Conversation Analysis methods. Setting/Participants: Twenty-five paediatric palliative care consultations (including face-to-face outpatient, telehealth outpatient and inpatient consultations) were video recorded within a public children's hospital in Australia. Participants included 14 health professionals, 15 child patients, 23 adult family members and 5 child siblings. Results: There was a pervasive relevance of both serious and non-serious talk about COVID-19 within the consultations recorded during the pandemic. Topics typical of a standard paediatric palliative care consultation often led to discussion of the pandemic. Clinicians (55%) and parents (45%) initiated talk about the pandemic. Conclusions: Clinicians should not be surprised by the pervasiveness of COVID-19 or other pandemic talk within standard paediatric palliative care consultations. This awareness will enable clinicians to flexibly address family needs and concerns about pandemic-related matters that may impact health and wellbeing.Katie Ekberg, Lara Weinglass, Stuart Ekberg, Susan Danby and Anthony Herber
Rationalisation in public dental care â impact on clinical work tasks and mechanical exposure for dentists â a prospective study
Swedish dentistry has been exposed to frequent rationalisation initiatives during the last half century. Previous research has shown that rationalisation often results in increased risk of developing work-related musculoskeletal disorders, thus reducing sustainability in the production system. In this prospective study, we assessed mechanical exposures among Swedish dentists in relation to specific rationalisations of clinical dental work during a six-year period. Body postures and movements of 12 dentists were assessed by inclinometry synchronised to video recordings of their work. No rationalisation effects could be shown in terms of a reduction in non-value-adding work (waste'), and at job level, no major differences in mechanical exposure could be shown between baseline and follow-up. Conclusion: The present rationalisation measures in dentistry do not seem to result in rationalisation at job level, but may potentially be more successful at the overall dental system level. Practitioner summary: In contrast to many previous investigations of the mechanical exposure implications of rationalisation, the present rationalisation measures did not increase the level of risk for dentists. It is highlighted that all occupations involved in the production system should be investigated to assess production system sustainability
Managing the therapeutic relationship in online cognitive behavioural therapy for depression:Therapists' treatment of clients' contributions
This article examines how therapists and clients manage the therapeutic relationship in online psychotherapy. Our study focuses on early sessions of therapy involving 22 therapist-client pairs participating in online Cognitive Behavioural Therapy (CBT) for depression. Using Conversation Analysis (CA), we examine how therapists can orient to clientsâ contributions, while also retaining control of the therapeutic trajectory. We report two practices that therapists can use, at their discretion, following clientsâ responses to requests for information. The first, thanking, accepts clientsâ responses, orienting to the neutral affective valence of those responses. The second, commiseration, orients to the negative affective valence of clientsâ responses. We argue that both practices are a means by which therapists can simultaneously manage developing rapport, while also retaining control of the therapeutic process
Managing clientsâ expectations at the outset of online Cognitive Behavioural Therapy (CBT) for depression
Background\ud
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Engaging clients in psychotherapy by managing their expectations is important for therapeutic success. Initial moments in first sessions of therapy are thought to afford an opportunity to establish a shared understanding of how therapy will proceed. However there is little evidence from analysis of actual sessions of therapy to support this.\ud
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Objective\ud
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This study utilised recordings to examine how therapists manage clientsâ expectations during the first two sessions of online Cognitive Behavioural Therapy (CBT). \ud
Methods Expectation management was investigated through conversation analysis of sessions from 176 client-therapist dyads involved in online CBT. The primary focus of analysis was expectation management during the initial moments of first sessions, with a secondary focus on expectations at subsequent points. \ud
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Analysis\ud
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Clientsâ expectations for therapy were most commonly managed during the initial moments of first sessions of therapy. At this point, most therapists either outlined the tasks of the first and subsequent sessions (n=36), or the first session only (n=108). On other occasions (n = 32), no attempt was made to manage clientsâ expectations by outlining what would happen in therapy. Observations of the interactional consequences of such an absence suggest clients may struggle to engage with the therapeutic process in the absence of appropriate expectation management by therapists. \ud
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Conclusion\ud
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Clients may more readily engage from the outset of therapy when provided with an explanation that manages their expectation of what is involved. Therapists can accomplish this by projecting how therapy will proceed, particularly beyond the initial session
Bronchial mucosal mast cells in asymptomatic smokers relation to structure, lung function and emphysema
AbstractThe pathologic mechanisms of chronic obstructive pulmonary disease (COPD) most certainly involves neutrophil granulocytes, cytotoxic T-cells, macophages and mast cells. The aim of this study was to investigate the relation between the number of mast cells in different compartments in bronchial biopsies of central proximal airways to structural changes, lung function tests and emphysema detected by high resolution computed tomography (HRCT).Twenty nine asymptomatic smoking and 16 never-smoking men from a population study were recruited. Central bronchial biopsies were stained to identify mast cells by immunohistochemistry. The number of mast cells in the epithelium, lamina propria and smooth muscle as well as epithelial integrity and thickness of the tenascin and laminin layer were determined.Smokers had increased numbers of mast cells in all compartments (P<0.001). Structural changes were correlated to mast cell numbers with the closest associations to mast cell numbers in the smooth muscle [epithelial integrity (Rs=â0.48, P=0.008), laminin layer (Rs=0.63, P=0.0002), tenascin layer (Rs=0.40, P=0.03)]. Similar correlations between mast cells and lung function tests were seen [functional residual capacity (FRC) (Rs=0.60, P=0.0006), total lung capacity (TLC) (Rs=0.44, P=0.02) and residual volume (RV) (Rs=0.41, P=0.03)]. No correlations could be detected between mast cells and FEV1 or to emphysema.Smoking is associated with an increase of mast cells in all compartments of the bronchial mucosa, including smooth muscle, and this is related to altered airway structure and function
Posterior cricoid region fluoroscopic findings: the posterior cricoid plication.
The region posterior to the cricoid cartilage is challenging to assess fluoroscopically. The purpose of this investigation is to critically evaluate the posterior cricoid (PC) region on fluoroscopy and describe patterns of common findings. This was a case control study. All fluoroscopic swallowing studies performed between June 16, 2009, and February 9, 2010, were reviewed for features seen in the PC region. These findings were categorized into distinct patterns and compared to fluoroscopic studies performed in a cohort of normal volunteers. Two hundred patient studies and 149 healthy volunteer studies were reviewed. The mean age of the referred patient cohort and the volunteer cohort was 57 years (±19) and 61 years (±16), respectively (p > 0.05). The patient cohort was 53% male and the control cohort was 56% female (p > 0.05). Four groups were identified. Pharyngoesophageal webs were seen in 7% (10/149) of controls and 14% (28/200) of patients (p = 0.03). A PC arch impression was seen in 16% of patients (32/200) and controls (24/149) (p = 1). A PC plication was demonstrated in 23% (34/149) of controls and 30% (60/200) of patients (p = 0.13). No distinctive PC region findings were seen in 54% (81/149) of controls and 42% (84/200) of referred patients (p = 0.02). Four patients (2%) had both a web and a PC plication. Four categories of PC region findings were identified (unremarkable PC region, web, PC arch impression, and PC plication). Both patients referred for swallowing studies and healthy volunteers demonstrated esophageal webs, PC arch impressions, and PC plications. Only webs were more common in patients than in control subjects (p = 0.03). The PC impression and PC plication are likely to represent normal variants that may be identified on fluoroscopic swallow studies
How Can eHealth Meet the Hearing and Communication Needs of Adults With Hearing Impairment and their Significant Others? A Group Concept Mapping Study
Objectives:
To seek the perspectives of key stakeholders regarding: (1) how eHealth could help meet the hearing and communication needs of adults with hearing impairment and their significant others; and (2) how helpful each aspect of eHealth would be to key stakeholders personally. /
Design:
Group concept mapping, a mixed-methods participatory research method, was used to seek the perspectives of key stakeholders: adults with hearing impairment (nâ=â39), significant others (nâ=â28), and hearing care professionals (nâ=â56). All participants completed a short online survey before completing one or more of the following activities: brainstorming, sorting, and rating. Brainstorming required participants to generate ideas in response to the focus prompt, âOne way I would like to use information and communication technologies to address the hearing and communication needs of adults with hearing loss and their family and friends is toâŠ.â The sorting task required participants to sort all statements into groups that made sense to them. Finally, the rating task required participants to rate each of the statements according to âHow helpful would this idea be to you?â using a 5-point Likert scale. Hierarchical cluster analysis was applied to the âsortingâ data to develop a cluster map using the Concept Systems software. The âratingâ data were subsequently analyzed at a cluster level and an individual-item level using descriptive statistics. Differences in cluster ratings between stakeholder groups were examined using Kruskal-Wallis tests. /
Results:
Overall, 123 statements were generated by participants in response to the focus prompt and were included in subsequent analyses. Based on the âsortingâ data and hierarchical cluster analysis, a seven-cluster map was deemed to be the best representation of the data. Three key themes emerged from the data, including using eHealth to (1) Educate and Involve Others; (2) Support Aural Rehabilitation; and (3) Educate About and Demonstrate the Impacts of Hearing Impairment and Benefits of Hearing Rehabilitation. Overall median rating scores for each cluster ranged from 3.97 (educate and involve significant others) to 3.44 (empower adults with hearing impairment to manage their hearing impairment from home). /
Conclusions:
These research findings demonstrate the broad range of clinical applications of eHealth that have the capacity to support the implementation of patient- and family-centered hearing care, with self-directed educational tools and resources typically being rated as most helpful. Therefore, eHealth appears to be a viable option for enabling a more biopsychosocial approach to hearing healthcare and educating and involving significant others in the hearing rehabilitation process without adding more pressure on clinical time. More research is needed to inform the subsequent development of eHealth interventions, and it is recommended that health behavior change theory be adhered to for such interventions
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