4,714 research outputs found

    Trajectory dynamics in innovation: developing and transforming a mobile money service across time and place

    Get PDF
    This paper examines how and why innovations are reshaped as they become implemented and used in locales that are distant and distinct from those where the innovation was initially developed. Drawing on an in-depth field study of the innovation process that produced a mobile money system for Kenya, we contribute an understanding of the particular dynamics that arise when an innovation trajectory interacts with local trajectories that constitute the local conditions and practices of specific places. We identify four distinct patterns of trajectory dynamics — separation, coordination, diversification, and integration — each of which has different implications for the innovation, its implementation, and consequences on the ground. Developing a model of trajectory dynamics in innovation, we theorize the processes through which innovations are transformed over time as they interact with multiple local trajectories, and the specific innovation outcomes that are generated as a result. Such theorizing reconceptualizes traditional notions of innovation diffusion by explicating how and why innovations change in multiple and unexpected ways as they move to particular places and engage with local conditions and practices

    The Megafobia V-armchair thrill-seeking experience for older audiences - An artistic intervention at Age UK Barnet

    Get PDF
    This demonstration session presents the artistic and experimental explorations of using VR technology and a motion simulator to allow older people to experience the thrill of roller coasters

    Microplastic in Riverine Fish is Connected to Species Traits

    Get PDF
    Microplastic is a contaminant of concern worldwide. Rivers are implicated as major pathways of microplastic transport to marine and lake ecosystems, and microplastic ingestion by freshwater biota is a risk associated with microplastic contamination, but there is little research on microplastic ecology within freshwater ecosystems. Microplastic uptake by fish is likely affected by environmental microplastic abundance and aspects of fish ecology, but these relationships have rarely been addressed. We measured the abundance and composition of microplastic in fish and surface waters from 3 major tributaries of Lake Michigan, USA. Microplastic was detected in fish and surface waters from all 3 sites, but there was no correlation between microplastic concentrations in fish and surface waters. Rather, there was a significant effect of functional feeding group on microplastic concentration in fish. Neogobius melanostomus (round goby, a zoobenthivore) had the highest concentration of gut microplastic (19 particles fish−1) compared to 10 other fish taxa measured, and had a positive linear relationship between body size and number of microplastic particles. Surface water microplastic concentrations were lowest in the most northern, forested watershed, and highest in the most southern, agriculturally dominated watershed. Results suggest microplastic pollution is common in river food webs and is connected to species feeding characteristics. Future research should focus on understanding the movement of microplastic from point-source and diffuse sources and into aquatic ecosystems, which will support pollution management efforts on inland waters

    Li Intercalation into Graphite: Direct Optical Imaging and Cahn–Hilliard Reaction Dynamics

    Get PDF
    Lithium intercalation into graphite is a critical process in energy storage technology. Studies of Li intercalation kinetics have proved challenging due to structural and phase complexity, and sample heterogeneity. Here we report direct time- and space-resolved, all-optical measurement of Li intercalation. We use a single crystal graphite electrode with lithographically defined disc geometry. All-optical, Raman and reflectance measurements distinguish the intrinsic intercalation process from side reactions, and provide new insight into the microscopic intercalation process. The recently proposed Cahn–Hilliard reaction (CHR) theory quantitatively captures the observed phase front spatial patterns and dynamics, using a two-layer free-energy model with novel, generalized Butler–Volmer kinetics. This approach unites Cahn–Hilliard and electrochemical kinetics, using a thermodynamically consistent description of the Li injection reaction at the crystal edge that involves a cooperative opening of graphene planes. The excellent agreement between experiment and theory presented here, with single-crystal resolution, provides strong support for the CHR theory of solid-state reactions.United States. Dept. of Energy. Office of Basic Energy Sciences (DE-SC0001085

    Use of a radiopaque localizer grid to reduce radiation exposure

    Get PDF
    Abstract Background Minimally invasive spine surgery requires placement of the skin incision at an ideal location in the patient's back by the surgeon. However, numerous fluoroscopic x-ray images are sometimes required to find the site of entry, thereby exposing patients and Operating Room personnel to additional radiation. To minimize this exposure, a radiopaque localizer grid was devised to increase planning efficiency and reduce radiation exposure. Results The radiopaque localizer grid was utilized to plan the point of entry for minimally invasive spine surgery. Use of the grid allowed the surgeon to accurately pinpoint the ideal entry point for the procedure with just one or two fluoroscopic X-ray images. Conclusions The reusable localizer grid is a simple and practical device that may be utilized to more efficiently plan an entry site on the skin, thus reducing radiation exposure. This device or a modified version may be utilized for any procedure involving the spine
    • 

    corecore