PTC (United Kingdom)

Summary This study shows the use of Distributed Acoustic Sensing (DAS) to monitor seasonal changes in shear wave velocity (Vs) on a railway embankment in Southern England. Fibre optic cables were installed along a 350m long embankment, and active seismic surveys using hammer impacts were conducted from Aug 2022 to Aug 2023. DAS measurements, correlated with soil moisture and matric suction, showed good agreement between seasonal moisture fluctuations and Vs. During dry periods, Vs values were higher, while wetter conditions resulted in lower values, indicating reduced soil stiffness. The findings demonstrate DAS-based MASW as an effective, high-resolution alternative to traditional geophysical methods to monitor railway embankments.

PurposeThe changes now being experienced in the workplace, driven by market pressures, changing demographics and new technologies, are real and accelerating. Since change remains the one constant when it comes to workplace planning, further transformations within the workplace over the next 20 or 30 years can be expected. Hence, this paper aims to demonstrate how to use a scenario planning futures approach in a changing, complex and uncertain workplace environment. As well as provoke thought and discussion about its long‐term future.Design/methodology/approachAt the Futures Academy in Dublin Institute of Technology, a systematic methodology for exploring and shaping the future has been developed, called the “Prospective through scenario” process. Each stage of the process is discussed in detail throughout this paper, as well as how the process is applied in the Johnson Controls workplace of the future study.FindingsThe creative “futures studies” approach can deal effectively with change, uncertainty and complexity in the workplace environment, by allowing those concerned to think, plan and act proactively rather than reactively as well as provide effective facilities management and real estate strategies.Practical implicationsReal estate organisations need to take the long view, for the greatest risk of our time is being overtaken by inevitable surprises that could have been foreseen and for which we could have been prepared.Originality/valueDiscussion and debate about the future of the workplace is inevitable and futures tools and techniques can facilitate this process.

Parachute recovery systems are described from a systems perspective. Parachute recovery is particularly suited to tactical fixed wing UAV systems that require a high degree of mobility by allowing air vehicle recovery onto unprepared terrain. The descent environment is described, and the impact of wind on recovery is considered. The relative merits of cruciform, round and parafoil canopies are assessed, taking three real‐world systems as design examples. Throughout, design considerations are approached from a systems perspective, with a view to producing safe, autonomous and accurate recovery systems.

SummaryThe microstructure of a metal matrix composite (MMC) consisting of 20 wt% 3 μm SiC particles in a 2124 Al alloy matrix has been examined and the relationship to corrosion pitting processes investigated. Standard bulk corrosion tests show that the MMC forms a higher density of pits than the unreinforced alloy, although the overall performance is similar as the pits are shallower. In a new addition to conventional characterization techniques, transmission electron microscopy samples have been directly subjected to ‘flash’ corrosion treatment and subsequently examined. This technique is shown to be effective in studying the initiation of pits. The SiC particles and the widespread 9 intermetallic precipitates are shown to play little, if any, role. A sparse population of features introduced during powder processing and consolidation procedures, probably linked with strong magnesium segregation, is suggested to be responsible for pit initiation.

This paper presents a range of techniques for image segmentation and edge detection based on co-occurrence matrices. Co-occurrence matrices are described and transforms are defined which adapt to global image characteristics and emphasise the differences between typical and atypical image features using co-occurrence matrices as look-up tables. The techniques are extended by analysing the matrices and labelling them, with the result that a labelled matrix can be used to segment the regions of an image and to simultaneously detect prominent edges. Examples are given for a variety of images: synthetic, infrared, multispectral and temporal. It is also shown that the techniques presented can be integrated easily with a variety of postprocessing techniques such as hysteresis and relaxation labelling for enhanced performance.

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