Temperature and strain rate effects on the mechanical properties of a polymer-bonded explosive

© 2018, The Author(s). The aim of the research reported here was to investigate the strain rate and temperature sensitivity of Rowanex 1100 Type 1A, a polymer-bonded explosive (PBX). The stress supported by this PBX at high rates of deformation (1750 ± 225 s−1) was found to be about an order of magnitude greater than that supported at low rates (0.015 s−1). Temperature was also found to have a large effect, with the strength of the material decreasing exponentially with temperature over the range studied (–60 to +60 °C). The exponents for the decay of the PBX’s strength with temperature at both low and high strain rates were the same within experimental error. So a temperature/strain rate shift factor could be determined and was found to be 31.2 ± 2.4 K/decade of strain rate.BAe Systems, Glascoed, U

Clinical effectiveness of a rehabilitation program integrating exercise, self-management, and active coping strategies for chronic knee pain: a cluster randomized trial.

OBJECTIVE: Chronic knee pain is a major cause of disability and health care expenditure, but there are concerns about efficacy, cost, and side effects associated with usual primary care. Conservative rehabilitation may offer a safe, effective, affordable alternative. We compared the effectiveness of a rehabilitation program integrating exercise, self-management, and active coping strategies (Enabling Self-management and Coping with Arthritic Knee Pain through Exercise [ESCAPE-knee pain]) with usual primary care in improving functioning in persons with chronic knee pain. METHODS: We conducted a single-blind, pragmatic, cluster randomized controlled trial. Participants age >/=50 years, reporting knee pain for >6 months, were recruited from 54 inner-city primary care practices. Primary care practices were randomized to continued usual primary care (i.e., whatever intervention a participant's primary care physician deemed appropriate), usual primary care plus the rehabilitation program delivered to individual participants, or usual primary care plus the rehabilitation program delivered to groups of 8 participants. The primary outcome was self-reported functioning (Western Ontario and McMaster Universities Osteoarthritis Index physical functioning [WOMAC-func]) 6 months after completing rehabilitation. RESULTS: A total of 418 participants were recruited; 76 (18%) withdrew, only 5 (1%) due to adverse events. Rehabilitated participants had better functioning than participants continuing usual primary care (-3.33 difference in WOMAC-func score; 95% confidence interval [95% CI] -5.88, -0.78; P = 0.01). Improvements were similar whether participants received individual rehabilitation (-3.53; 95% CI -6.52, -0.55) or group rehabilitation (-3.16; 95% CI -6.55, -0.12). CONCLUSION: ESCAPE-knee pain provides a safe, relatively brief intervention for chronic knee pain that is equally effective whether delivered to individuals or groups of participants

Characterisation of the impact response of energetic materials: Observation of a low-level reaction in 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

Time resolved and integrated diagnostics including high speed photography, mass and optical spectroscopy, and optical-radiometry used to study impact response of high explosives in far more detail than possible with conventional sensitiveness tests.The authors wish to acknowledge the funding and provision of samples for this research by AWE plc.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C6RA03096

Approximating k-Forest with Resource Augmentation: A Primal-Dual Approach

In this paper, we study the $k$-forest problem in the model of resource augmentation. In the $k$-forest problem, given an edge-weighted graph $G(V,E)$, a parameter $k$, and a set of $m$ demand pairs $\subseteq V \times V$, the objective is to construct a minimum-cost subgraph that connects at least $k$ demands. The problem is hard to approximate---the best-known approximation ratio is $O(\min\{\sqrt{n}, \sqrt{k}\})$. Furthermore, $k$-forest is as hard to approximate as the notoriously-hard densest $k$-subgraph problem. While the $k$-forest problem is hard to approximate in the worst-case, we show that with the use of resource augmentation, we can efficiently approximate it up to a constant factor. First, we restate the problem in terms of the number of demands that are {\em not} connected. In particular, the objective of the $k$-forest problem can be viewed as to remove at most $m-k$ demands and find a minimum-cost subgraph that connects the remaining demands. We use this perspective of the problem to explain the performance of our algorithm (in terms of the augmentation) in a more intuitive way. Specifically, we present a polynomial-time algorithm for the $k$-forest problem that, for every $\epsilon>0$, removes at most $m-k$ demands and has cost no more than $O(1/\epsilon^{2})$ times the cost of an optimal algorithm that removes at most $(1-\epsilon)(m-k)$ demands

Prescribing hand strengthening exercise for patients with rheumatoid arthritis; clinical cues influencing occupational therapists' and physiotherapists' judgements

Acknowledgements: The authors acknowledge the therapists who took part in both phases of this study. This work was supported by Brunel University London and the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care Oxford at Oxford Health NHS Foundation Trust, and supported by the NIHR Biomedical Research Centre, Oxford.Data Availability Statement: The data that support the findings for phase 2 of this study are openly available in figshare at https://doi.org/10.6084/m9.figshare.24681309 .Supporting Information is available online at: https://onlinelibrary.wiley.com/doi/full/10.1002/msc.1849#support-information-section .Copyright © 2023 The Authors. Objective: To explore the clinical judgements of therapists in prescribing the intensity of hand strengthening exercise in rheumatoid arthritis (RA). Methods: Phase I: Eleven therapists knowledgeable in treating patients with RA subjectively identified seven clinical cues. These were incorporated into 54 hypothetical patient case scenarios. Phase II: Therapists with ≥2 years post-registration experience and current or recent experience in treating patients with RA were asked to assess 69 case scenarios in total (54 + 15 repeats) and judge what intensity of hand strengthening exercise they would prescribe using the OMNI-Resistance Exercise Scale of perceived exertion. Using responses to the repeated cases, the Cochran-Weiss-Shanteau index of expertise was used to identify therapists who prescribed more consistently. Multiple regression was used to determine which clinical cues were most strongly associated with the intensity of exercise prescribed. A sub-group analysis explored differences between consistent and inconsistent prescribers. Results: Fifty-three therapists took part. Thirty completed all 69 case scenarios. Across all therapists, the three most important clinical cues associated with lower intensity of exercise prescribed were (1) Patient's reported pain intensity whilst practising the exercise (β = −1.150, p < 0.001), (2) Disease activity (β = −0.425, p < 0.001) and (3) average hand pain over the last week (β = −0.353 p < 0.001). Twelve therapists were categorised as consistent prescribers. This group relied on fewer clinical cues (three vs. seven) when judging what intensity of exercise to prescribe. Conclusion: This study provides insights into how therapists prescribe hand exercises. Intensity of hand strengthening exercise was influenced by three key clinical cues, including pain intensity and disease activity.Brunel University London; National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care Oxford at Oxford Health NHS Foundation Trust; NIHR Biomedical Research Centre, Oxford

Recommendations for exercise adherence measures in musculoskeletal settings : a systematic review and consensus meeting (protocol)

Background: Exercise programmes are frequently advocated for the management of musculoskeletal disorders; however, adherence is an important pre-requisite for their success. The assessment of exercise adherence requires the use of relevant and appropriate measures, but guidance for appropriate assessment does not exist. This research will identify and evaluate the quality and acceptability of all measures used to assess exercise adherence within a musculoskeletal setting, seeking to reach consensus for the most relevant and appropriate measures for application in research and/or clinical practice settings. Methods/design: There are two key stages to the proposed research. First, a systematic review of the quality and acceptability of measures used to assess exercise adherence in musculoskeletal disorders; second, a consensus meeting. The systematic review will be conducted in two phases and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to ensure a robust methodology. Phase one will identify all measures that have been used to assess exercise adherence in a musculoskeletal setting. Phase two will seek to identify published and unpublished evidence of the measurement and practical properties of identified measures. Study quality will be assessed against the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidelines. A shortlist of best quality measures will be produced for consideration during stage two: a meeting of relevant stakeholders in the United Kingdom during which consensus on the most relevant and appropriate measures of exercise adherence for application in research and/or clinical practice settings will be sought. Discussion: This study will benefit clinicians who seek to evaluate patients’ levels of exercise adherence and those intending to undertake research, service evaluation, or audit relating to exercise adherence in the musculoskeletal field. The findings will impact upon new research studies which aim to understand the factors that predict adherence with exercise and which test different adherence-enhancing interventions. PROSPERO reference: CRD4201300621

Neonicotinoid pesticide limits improvement in buzz pollination by bumblebees

Neonicotinoid pesticides have been linked to global declines of beneficial insects such as bumblebees. Exposure to trace levels of these chemicals causes sub-lethal effects, such as reduced learning and foraging efficiency. Complex behaviours may be particularly vulnerable to the neurotoxic effects of neonicotinoids. Such behaviours may include buzz pollination (sonication), in which pollinators, usually bees, use innate and learned behaviours to generate high-frequency vibrations to release pollen from flowers with specialised anther morphologies. This study assesses the effect of field-realistic, chronic exposure to the widely-used neonicotinoid thiamethoxam on the development of sonication buzz characteristics over time, as well as the collection of pollen from buzz-pollinated flowers. We found that the pollen collection of exposed bees improved less with increasing experience than that of unexposed bees, with exposed bees collecting between 47% and 56% less pollen by the end of 10 trials. We also found evidence of two distinct strategies for maximising pollen collection: (1) extensions to the duration of individual buzzes and (2) extensions of the overall time spent buzzing. We find new complexities in buzz pollination, and conclude that the impacts of field-realistic exposure to a neonicotinoid pesticide may seriously compromise this important ecosystem service

Fuzzy Inference Systems for Invariant Pattern Recognition in MFL NDE

Defect related information present in NDE signals is frequently obscured by the presence of operational variables inherent in the system. A typical NDE system comprises of an energy source, a test specimen and a sensor array. Operational variables include uncontrollable changes in source signal strength and/or frequency, variations in the sensitivity of the sensor and alterations in the material properties of the test specimen. These operational variables can confuse subsequent signal interpretation schemes, such as those relying on artificial neural networks. Invariant pattern recognition methods are required to ensure accurate signal characterization in terms of the underlying defect geometry. This paper describes a generalized invariance transformation technique to compensate for operational variables in NDE systems. An application to magnetic flux leakage (MFL) inspection of gas transmission pipelines is presented. The technique is employed to compensate for variations in magnetization characteristics in the pipe wall