Modelling the failure modes in geobag revetments

In recent years, sand filled geotextile bags (geobags) have been used as a means of long-term riverbank revetment stabilization. However, despite their deployment in a significant number of locations, the failure modes of such structures are not well understood. Three interactions influence the geobag performance, i.e. geobag-geobag, geobag-water flow and geobag-water flow-river bank. The aim of the research reported here is to develop a detailed understanding of the failure mechanisms in a geobag revetment using a discrete element model (DEM) validated by laboratory data. The laboratory measured velocity data were used for preparing a mapped velocity field for a coupled DEM simulation of geobag revetment failure. The validated DEM model could identify well the critical bag location in varying water depths. Toe scour, one of the major instability factors in revetments, and its influence on the bottom-most layer of the bags were also reasonably represented in this DEM model. It is envisaged that the use of a DEM model will provide more details on geobag revetment performance in riverbanks.     

Advances in the display quality of dye-doped polymer-dispersed liquid crystal films by addition of disc-shaped multidirectional light-control film

Typically, the addition of a dye is considered to increase the contrast ratio (CR) of a polymer-dispersed liquid crystal (PDLC) display; however, with the addition of a small amount of dye, the contrast ratio (CR) unexpectedly decreased as compare to the CR of a normal white PDLC display, attributed to various reasons. In this study, an additional multidirectional light scattering polymer film is developed over a conventional dye-doped polymer-dispersed liquid crystal (DPDLC) film to enhance the CR. For this, a disc-shape (DS) pattern on PN393 film is coated. This structure is believed to enhance the scattering properties of DPDLC displays via multiple-directional scattering nature of DS pattern film. Fabrications of such devices are simple and have advantageous of its low-cost production. This optimal designed disc-shaped light-scattering (DSS) film resulted in the enhancement of the CR of the DPDLCs.     

Continuance of mHealth services at the bottom of the pyramid: the roles of service quality and trust

Continued usage of information systems (or, IS continuance) has proven to be a critical success parameter for ICT implementation at the top of the global economic pyramid. However, there are few studies which have explored continued IS usage at the bottom of the economic pyramid (BOP) though it represents the majority of the world’s population. To fill this knowledge gap, this study develops an mHealth continuance model at the BOP framing the impact of two post adoption expectation beliefs (i.e., perceived service quality and perceived trust). This study extends ECM (expectation confirmation model) perspective synthesizing the extant literature on continued IS usage, service quality and consumer trust. The proposed model was empirically tested within the context of mHealth (mobile health) services at the BOP, applying PLS (partial least squares) under a cross sectional study. The findings confirm that both perceived service quality and perceived trust have significant explanatory power under an integrated ECM providing superior prediction of continuance intentions. The study concludes by discussing conceptual contributions, practical implications, limitations and future research directions.