Measurements of some parameters of thermal sparks with respect to their ability to ignite aviation fuel/air mixtures

A method used to generate thermal sparks for experimental purposes and methods by which parameters of the sparks, such as speed, size, and temperature, were measured are described. Values are given of the range of such parameters within these spark showers. Titanium sparks were used almost exclusively, since it is particles of this metal which are found to be ejected during simulation tests to carbon fiber composite (CFC) joints. Tests were then carried out in which titanium sparks and spark showers were injected into JP4/(AVTAG F40) mixtures with air. Single large sparks and dense showers of small sparks were found to be capable of causing ignition. Tests were then repeated using ethylene/air mixtures, which were found to be more easily ignited by thermal sparks than the JP4/ air mixtures

Review of top of rail friction modifier tribology

© 2016 Informa UK Limited, trading as Taylor & Francis Group.The aim of this paper was to review the current state of research for top of rail friction modifiers (TORFM). In the railway industry, friction modifiers is a catch all term for a wide range of products applied for different purposes which has led to confusion. It is hoped that recently published definitions will aid industry to a better understanding of the different products and how they function. The benefits of friction modifiers are well understood with a large body of research supporting the benefits. Comparatively, there is a lot less knowledge of the optimum amount of product to achieve the benefits or how far down the track from an application site the benefit will be seen. Modelling of the products is another area where there is little research, with most of the modelling papers found focussing on dry wheel–rail contact due to the complexity of introducing a third-body layer to a friction force model. Furthermore, only one paper was found which relates how friction modifiers are affected by contaminants or other applied products such as lubricants. With many different products applied to wheels and rail for different purposes, understanding their interaction is key. At the time of this review, there are currently no standards that prescribe how TORFM should behave although the European Committee for Standardisation is currently developing them at the moment. This review has also attempted to appraise the research against a set of criteria. Depending on how many of the criteria the piece of research filled, it was categorised as A, B or C. It was found that most of the research was of category, this was mainly due to only one test method being used or the scale presented. Category A research incorporated modelling or multiple test-scales to support the results presented

New laboratory methodologies to analyse the top of rail friction modifier performance across different test scales

Test methodologies originally developed for greases have been adapted to be used for top of rail friction modifiers (TORFMs). This has included: a small-scale benchtop tribometer to measure the tackiness of different TORFMs, attaching an applicator bar to a section of rail and rolling a scaled-wheel through the TORFM applied to the rail head to analyse the effect of different variables on pick-up, and applying TORFM to a full-scale test facility to analyse the scaling effects and the effect of slip, load and speed on pick-up. These methods can be used to measure the relative performance of different TORFMs with respect to how much product is picked up by the wheel. The results have shown that the relative ranking of different TORFMs is the same across the three test scales. This shows that these small-scale test methods that are more suitable for inclusion in test standards could be used to reduce the need for the more time-consuming and expensive larger scale tests, as the relative performance is the same

A comparison of friction modifier performance using two laboratory test scales

This paper describes two methods, carried out at two different test scales, for assessing the friction modifier performance. Study A used the wear data from a full-scale rig test at the voestalpine Schienen GmbH and compared it with the wear data from twin disc tests using the SUROS test machine at the University of Sheffield. Study B compared the ‘retentivity’ data, from a full-scale rig at the University of Sheffield, with the data from the SUROS tests. Study A concluded that a good correlation existed between the two scales although assumptions made in the full-scale contact calculation introduce a large spread into the results. There was a greater correlation between the two data sets at more severe contact conditions. Study B showed a different baseline coefficient of traction between the two scales and that a longer test length is required to fully evaluate the ‘retention’ of the friction modifier on the full-scale rig. The paper expands on a previous conference presentation on the same subject. Additional information on the test procedure and test rigs is included here. Surface and subsurface analyses of the SUROS test samples have also been added. The analyses have shown that applying the friction modifier leads to a similar wear mechanism as for the dry contact, but the wear is less severe and there is less subsurface deformation. A discussion describing the differences in test scales and comparing lab tests to field operation is also included

Using realist approaches in nutrition and dietetics research

Aim: The aim of this study was to explore the use and future potential of realist approaches to research in nutrition and dietetics. Methods: A targeted literature review was used to search key journals (n = 7) in nutrition and dietetics to identify existing research using a realist approach. A narrative synthesis was conducted to explore findings in relation to the research aim. Results: Nine research papers (four realist evaluations, five realist reviews) describing seven nutrition interventions were found, which revealed the application of realist research in nutrition and dietetics has focused on public health interventions. Realist research provided a deeper, more nuanced understanding of varied outcomes including the role of context, and contributed to the development of theory about how and why interventions work. As a theory-driven research method, realist research was able to assist in overcoming methodological shortcomings to contribute to meaningful, transferable findings. Conclusion: The results highlight the potential contribution of the realist research in nutrition and dietetics to evaluate interventions and inform future practice

Web-based multimodal graphs for visually impaired people

This paper describes the development and evaluation of Web-based multimodal graphs designed for visually impaired and blind people. The information in the graphs is conveyed to visually impaired people through haptic and audio channels. The motivation of this work is to address problems faced by visually impaired people in accessing graphical information on the Internet, particularly the common types of graphs for data visualization. In our work, line graphs, bar charts and pie charts are accessible through a force feedback device, the Logitech WingMan Force Feedback Mouse. Pre-recorded sound files are used to represent graph contents to users. In order to test the usability of the developed Web graphs, an evaluation was conducted with bar charts as the experimental platform. The results showed that the participants could successfully use the haptic and audio features to extract information from the Web graphs

Ultrasonic monitoring of insulated block joints

Insulated block joints are essential components used in railway tracks, to separate them into circuits used for train detection and signalling. However, they also represent a week point in the track system, and have a finite life. Condition monitoring of these components in order to plan preventative maintenance is currently labour intensive, and can lead to significant costs for the rail operator. In this study, IBJ’s were fatigued via shear load, whilst being condition monitored for degradation using a normally incident ultrasonic technique. Tests were also initially performed on lap-joints and shear specimens to further understand the response of the ultrasonic signal to failure of the adhesive layer under controlled conditions. Dynamic reflection coefficients as well as applied load were recorded in all tests, and results compared to failure zones on the specimens. The results showed that the ultrasonic technique was able to determine the on-set of failure and de-bonding of the adhesive layer, as well as degradation and wear. The technique was also able to highlight differences in performance between two different liners, pultruded glass reinforced polyester resin and a flexible glass fibre sheet, with the latter showing improved resistance. The outcomes of this study have highlighted the viability of condition monitoring IBJs using an ultrasonic approach, and have provided a basis for a future field trial

Magnescope: Applications in nondestructive evaluation

This paper describes recent results obtained with the Magnescope, which has been used on location in industrial environments and has successfully detected impending fatigue failure, creep damage, applied stress, and microstructural differences. It is concluded that the device provides a useful nondestructive method for evaluating the mechanical properties of materials through the measurement of their structure sensitive magnetic properties

A Feasibility Study of Quantifying Longitudinal Brain Changes in Herpes Simplex Virus (HSV) Encephalitis Using Magnetic Resonance Imaging (MRI) and Stereology.

OBJECTIVES: To assess whether it is feasible to quantify acute change in temporal lobe volume and total oedema volumes in herpes simplex virus (HSV) encephalitis as a preliminary to a trial of corticosteroid therapy. METHODS: The study analysed serially acquired magnetic resonance images (MRI), of patients with acute HSV encephalitis who had neuroimaging repeated within four weeks of the first scan. We performed volumetric measurements of the left and right temporal lobes and of cerebral oedema visible on T2 weighted Fluid Attenuated Inversion Recovery (FLAIR) images using stereology in conjunction with point counting. RESULTS: Temporal lobe volumes increased on average by 1.6% (standard deviation (SD 11%) in five patients who had not received corticosteroid therapy and decreased in two patients who had received corticosteroids by 8.5%. FLAIR hyperintensity volumes increased by 9% in patients not receiving treatment with corticosteroids and decreased by 29% in the two patients that had received corticosteroids. CONCLUSIONS: This study has shown it is feasible to quantify acute change in temporal lobe and total oedema volumes in HSV encephalitis and suggests a potential resolution of swelling in response to corticosteroid therapy. These techniques could be used as part of a randomized control trial to investigate the efficacy of corticosteroids for treating HSV encephalitis in conjunction with assessing clinical outcomes and could be of potential value in helping to predict the clinical outcomes of patients with HSV encephalitis

The Mental Wellbeing of Child and Adolescent Mental Health Service (CAMHS) Workers in England: A Cross-Sectional Descriptive Study Reporting Levels of Burnout, Wellbeing and Job Satisfaction

In the UK, there has been a notable increase in referrals to specialist children’s mental health services. This, coupled with shortages of qualified staff, has raised concerns about the escalating occupational stress experienced by staff in this sector. In this brief report, we present cross-sectional quantitative data from 97 staff members working in one Child and Adolescent Mental Health Service (CAMHS) in the UK during spring 2023, reporting on their wellbeing, job satisfaction, and burnout. Our findings reveal that over a third of CAMHS staff experienced moderate or high levels of work-related burnout; 39% reported moderate or high levels of personal burnout, but levels of client-related burnout were much lower (13%). Both work- and client-related burnout showed a robust negative relationship with job satisfaction, with higher burnout predicting lower levels of job satisfaction. Only a small proportion of respondents reported high levels of wellbeing, with about a quarter experiencing levels of wellbeing that can be considered indicative of mild or clinical depressive symptoms. Whilst these results are from a small sample in one area of the UK, they present an important snapshot of CAMHS staff wellbeing and are discussed in the context of similar trends reported in the wider NHS sector