1,987 research outputs found

    Advances in the inspection of unpiggable pipelines

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    The field of in-pipe robotics covers a vast and varied number of approaches to the inspection of pipelines with robots specialising in pipes ranging anywhere from 10 mm to 1200 mm in diameter. Many of these developed systems focus on overcoming in-pipe obstacles such as T-sections and elbows, as a result important aspects of exploration are treated as sub-systems, namely shape adaptability. One of the most prevalent methods of hybridised locomotion today is wall-pressing; generating traction using the encompassing pipe walls. A review of wall-pressing systems has been performed, covering the different approaches taken since their introduction. The advantages and disadvantages of these systems is discussed as well as their effectiveness in the inspection of networks with highly varying pipe diameters. When compared to unconventional in-pipe robotic techniques, traditional full-bore wall-pressing robots were found to be at a disadvantage

    Modeled and Observed Volcanic Aerosol Control on Stratospheric NOy and Cly

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    Decreases in stratospheric NOx associated with enhanced aerosol have been observed after large volcanic eruptions, for example, after the eruption of Mount Pinatubo in 1991. While the 1991 Mount Pinatubo eruption was the last large explosive eruption, recent studies have shed light on the impacts of moderate-sized eruptions since the year 2000 on the global stratospheric aerosol budget. We use an ensemble of simulations from a coupled climate-chemistry model to quantify and analyze changes in NO and NO2 (NOx), N2O5, HNO3, ClO, and ClONO2 during periods of increased stratospheric volcanic aerosol concentrations since 2000. By using an ensemble approach, we are able to distinguish forced responses from internal variability. We also compare the model ensemble results to satellite measurements of these changes in atmospheric composition, including measurements from the Optical Spectrograph and Infrared Imaging Spectrometer on the Odin satellite and the Aura Microwave Limb Sounder. We find decreases in stratospheric NOx concentrations up to 20 hPa, consistent with increases in stratospheric HNO3 concentrations. The HNO3 perturbations also extend higher, up to 5 hPa, associated with periods of increased volcanic aerosol concentrations in both model simulations and observations, though correlations with volcanic aerosol are considerably higher in the model simulations. The model simulates increases in ClO at altitudes and magnitudes similar to the NOx reductions, but this response is below the detectable limit in the available observations (100 pptv). We also demonstrate the value of accounting for transport-related anomalies of atmospheric trace gases by regression onto N2O anomalies

    Miniature Magnetic Robots For In-Pipe Locomotion

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    Inspection of both small and large diameter bore pipelines for pipe integrity and defect identification with a single system has previously been impractical; especially using wall-press locomotion methods with low adaptive range. A miniature magnetic wallclimbing robot has been developed as a robotic solution for the inspection of 50mm bore diameter pipelines which can scale in-pipe geometry obstacles to access larger connected pipelines. Using magnetic arrays directed through steel flux plates within the wheels, the robot uses magnetic forces to adhere to the pipe. The system is 3D printed and includes soft printed material rubber wheels. The robot prototype is wirelessly driven, controlled remotely through serial Bluetooth communication radio at 2.4 GHz rated up to 100m. The robot’s unique compact geometry and magnetic design allows it to scale concave rightangle wall cases in just a 50mm diameter bore. By entering pipe networks through these small existing access points the robot removes the need for expensive drilling procedures required to fit launch vessels

    Sensory ways to indigenous multimodal literacies : Hands and feet tell the story

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    This chapter reports original research that asks the question: What are the ways of knowing, being, and communicating that are valued and practiced in Indigenous communities? Literacy curricula, internationally and nationally, typically do not take into account the multi-sensorial dimensions of non-Western forms of representation that go beyond narrow conceptions of print. For example, literacies are often conceived as drawing on print, visual, spatial, gestural, and audio modes, but the role of haptics and locomotion has typically received little attention. This chapter highlights examples of the multi-sensoriality of Indigenous literacies observed in participatory community research with an Indigenous school. It extends recent theories of sensory studies in the history and cultural anthropology of the senses, applying these principles to literacy education. Sensory literacies is a theoretical perspective that gives priority to the sensorial dimensions of the body and its role in communication in literacy practice, because without a sensing body, we cannot know about or communicate with the world. The data demonstrates how the forgotten role of the hands and feet in dominant theories of communication is central to Indigenous identity and literacies. Written by a white academic with an Indigenous researcher, the chapter problematises the privileging of narrow, logocentric, and Western forms of literacy and its implications for rethinking the role of the whole body in literacy and the literacy curriculum for Indigenous students

    Contractility Dominates Adhesive Ligand Density in Regulating Cellular De-adhesion and Retraction Kinetics

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    Cells that are enzymatically detached from a solid substrate rapidly round up as the tensile prestress in the cytoskeleton is suddenly unopposed by cell–ECM adhesions. We recently showed that this retraction follows sigmoidal kinetics with time constants that correlate closely with cortical stiffness values. This raises the promising prospect that these de-adhesion measurements may be used for high-throughput screening of cell mechanical properties; however, an important limitation to doing so is the possibility that the retraction kinetics may also be influenced and potentially rate-limited by the time needed to sever matrix adhesions. In this study, we address this open question by separating contributions of contractility and adhesion to cellular de-adhesion and retraction kinetics. We first develop serum-free conditions under which U373 MG glioma cells can be cultured on substrates of fixed fibronectin density without direct matrix contributions from the medium. We show that while spreading area increases with ECM protein density, cortical stiffness and the time constants of retraction do not. Conversely, addition of lysophosphatidic acid (LPA) to stimulate cell contractility strongly speeds retraction, independent of the initial matrix protein density and LPA’s contributions to spreading area. All of these trends hold in serum-rich medium commonly used in tissue culture, with the time constants of retraction much more closely tracking cortical stiffness than adhesive ligand density or cell spreading. These results support the use of cellular de-adhesion measurements to track cellular mechanical properties

    "I could cry, the amount of shoes I can't get into": A qualitative exploration of the factors that influence retail footwear selection in women with rheumatoid arthritis

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    <p>Abstract</p> <p>Background</p> <p>Studies have reported that women with rheumatoid arthritis (RA) are not wearing NHS supplied therapeutic footwear; therefore it is likely they are wearing footwear sourced through retailers. Previous research gives limited information (largely associated with cosmesis) on people's perceptions on the relationships that exist between retail footwear, well-being and quality of life. This study aimed to explore the perceptions of women with RA regarding their choice of retail footwear and identify the factors influencing retail footwear selection.</p> <p>Methods</p> <p>Eleven women with RA wearing normal retail footwear were recruited from an out-patient podiatry clinic in the south east of England. Semi-structured interviews were carried out and an interpretative phenomenological approach was adopted for data collection and transcript analysis.</p> <p>Results</p> <p>Six key themes were revealed from the analysis: (1) the nature of foot complaints and deformities, (2) aesthetic appearance and design of footwear, (3) body image, (4) psychosocial aspects, (5) Perceptions of footwear and (6) the therapeutic value of retail shoes. These contributed to an overarching concept of loss of choice associated with retail footwear. In particular, the areas discussed most frequently throughout were themes (2), (3) and (4), which were notably more 'emotional' in nature.</p> <p>Conclusions</p> <p>Limitations in retail footwear for these women have impacted on their individuality, linking significantly with their body image. The loss of choice in footwear as a consequence of the disease impacts negatively on emotions, wellbeing and was identified in reduced self-perceived quality of life.</p
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