1,078 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
CHIANTI - An atomic database for emission lines. XI. EUV emission lines of Fe VII, Fe VIII and Fe IX observed by Hinode/EIS
A detailed study of emission lines from Fe VII, Fe VIII and Fe IX observed by
the EUV Imaging Spectrometer on board the Hinode satellite is presented.
Spectra in the ranges 170-212 A and 246-292 A show strongly enhanced lines from
the upper solar transition region (temperatures 5.4 <= log T <= 5.9) allowing a
number of new line identifications to be made. Comparisons of Fe VII lines with
predictions from a new atomic model reveal new plasma diagnostics, however
there are a number of disagreements between theory and observation for emission
line ratios insensitive to density and temperature, suggesting improved atomic
data are required. Line ratios for Fe VIII also show discrepancies with theory,
with the strong 185.21 and 186.60 lines under-estimated by 60-80 % compared to
lines between 192 and 198 A. A newly-identified multiplet between 253.9 and
255.8 A offers excellent temperature diagnostic opportunities relative to the
lines between 185-198 A, however the atomic model under-estimates the strength
of these lines by factors 3-6. Two new line identifications are made for Fe IX
at wavelengths 176.959 A and 177.594 A, while seven other lines between 186 and
200 A are suggested to be due to Fe IX but for which transition identifications
can not be made. The new atomic data for Fe VII and Fe IX are demonstrated to
significantly modify models for the response function of the TRACE 195 A
imaging channel, affecting temperature determinations from this channel. The
data will also affect the response functions for other solar EUV imaging
instruments such as SOHO/EIT, STEREO/EUVI and the upcoming AIA instrument on
the Solar Dynamics Observatory.Comment: 51 pages, submitted to Ap
Assessment of the Food-Swallowing Process Using Bolus Visualisation and Manometry Simultaneously in a Device that Models Human Swallowing
The characteristics of the flows of boluses with different consistencies, i.e. different rheological properties, through the pharynx have not been fully elucidated. The results obtained using a novel in vitro device, the Gothenburg Throat, which allows simultaneous bolus flow visualisation and manometry assessments in the pharynx geometry, are presented, to explain the dependence of bolus flow on bolus consistency. Four different bolus consistencies of a commercial food thickener, 0.5, 1, 1.5 and 2\ua0Pa\ua0s (at a shear rate of 50\ua0s â1 )âcorresponding to a range from low honey-thick to pudding-thick consistencies on the National Dysphagia Diet (NDD) scaleâwere examined in the in vitro pharynx. The bolus velocities recorded in the simulator pharynx were in the range of 0.046â0.48\ua0m/s, which is within the range reported in clinical studies. The corresponding wall shear rates associated with these velocities ranged from 13\ua0s â1 (pudding consistency) to 209\ua0s â1 (honey-thick consistency). The results of the in vitro manometry tests using different consistencies and bolus volumes were rather similar to those obtained in clinical studies. The in vitro device used in this study appears to be a valuable tool for pre-clinical analyses of thickened fluids. Furthermore, the results show that it is desirable to consider a broad range of shear rates when assessing the suitability of a certain consistency for swallowing
Orienting to Emotion in Computer-Mediated Cognitive Behavioral Therapy
Exploring emotions is a defining feature of psychotherapy. This study explores how therapists explore emotions when they cannot see or hear their clients. In analysing 1,279 sessions of online text-based Cognitive Behavioural Therapy (<i>CBT</i>) we focused on therapistsâ commiserations (e.g., âIâm sorry to hear thatâ) and their affective inferences (e.g., âthat sounds very scary for youâ). Both practices routinely prefaced moves to pursue a range of therapeutic activities, many of which did not prioritise sustained focus on the emotion that had just been oriented to. By separating message composition from message transmission, the modality used for these therapy sessions enabled therapists to combine orientations to emotion with attempts to shift the focus of discussion. Our analysis finds that although physically co-present and computer-mediated psychotherapy share a common focus on emotional experience, the modality used for therapy can be relevant in the design and use of these orientations. Data are in British English
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
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