Azobenzene-based gel coated fibre Bragg grating sensor for moisture measurement

A fibre Bragg grating sensor is coated with a novel polymer gel in order to investigate its suitability for nondestructive measurement of moisture in materials that can potentially lose their integrity due to moisture ingress. Absorption and desorption of moisture lead to swelling/shrinkage of an azobenzene-based gel, which induces a strain in the Bragg grating resulting in wavelength shifts. The results demonstrated that the amount of wavelength shift is linearly dependent on the amount of water ingress by the gel. The performance of the proposed optical fibre moisture sensor was found to be repeatable with no detectable hysteresis and has the potential to offer a low-cost route for monitoring moisture content

Self-healing in epoxy thermoset polymer films triggered by UV light

Self-healing of damaged structures can occur in three processes: capsule-based healing, vascular healing and intrinsic healing of polymers. The latest concept has a tremendous potential to repair damaged polymers and composite structures. Until now self-healing of composite materials has been addressed using capsule based resin with an initiator that polymerises in the damaged region. In this study, self-healing behaviour of cured epoxy thermoset resins modified with an epoxy-functionalised photoresponsive azobenzene molecule has been addressed by UV light without the use of any resin capsules or other component that is not chemically joined with the composites. The study was executed by nanoindentation and atomic force microscopy (AFM). Artificially damaged thermoset films exhibited good self-healing behaviour under UV irradiation only. This effect is attributed to the intrinsic healing mechanism triggered by UV-induced trans→cis isomerization of the azobenzene chromophore which enables the damaged polymeric matrix to recover.Funded by Defence Science and Technology Laboratory (DSTL

A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing

This article proposes a design and implementation of a low cost two-tier architecture model for high availability cluster combined with load-balancing and shared storage technology to achieve desired scale of three-tier architecture for application load balancing e.g. web servers. The research work proposes a design that physically omits Network File System (NFS) server nodes and implements NFS server functionalities within the cluster nodes, through Red Hat Cluster Suite (RHCS) with High Availability (HA) proxy load balancing technologies. In order to achieve a low-cost implementation in terms of investment in hardware and computing solutions, the proposed architecture will be beneficial. This system intends to provide steady service despite any system components fails due to uncertainly such as network system, storage and applications.Comment: Load balancing, high availability cluster, web server cluster

Comparative Study on Agile software development methodologies

Today-s business environment is very much dynamic, and organisations are constantly changing their software requirements to adjust with new environment. They also demand for fast delivery of software products as well as for accepting changing requirements. In this aspect, traditional plan-driven developments fail to meet up these requirements. Though traditional software development methodologies, such as life cycle-based structured and object oriented approaches, continue to dominate the systems development few decades and much research has done in traditional methodologies, Agile software development brings its own set of novel challenges that must be addressed to satisfy the customer through early and continuous delivery of the valuable software. It is a set of software development methods based on iterative and incremental development process, where requirements and development evolve through collaboration between self-organizing, cross-functional teams that allows rapid delivery of high quality software to meet customer needs and also accommodate changes in the requirements. In this paper, we significantly identify and describe the major factors, that Agile development approach improves software development process to meet the rapid changing business environments. We also provide a brief comparison of agile development methodologies with traditional systems development methodologies, and discuss current state of adopting agile methodologies. We speculate that from the need to satisfy the customer through early and continuous delivery of the valuable software, Agile software development is emerged as an alternative to traditional plan-based software development methods. The purpose of this paper, is to provide an in-depth understanding, the major benefits of agile development approach to software development industry, as well as provide a comparison study report of ASDM over TSDM.Comment: 25 pages, 25 images, 86 references used, with authors biographie

Electoral Legitimacy, Preventive Representation, and Regularization of Authoritarian Democracy in Bangladesh

Despite variations in its forms, contents, and qualities, arguably regular election is the only tool that upholds the “democratic” label of a government. Election works as the only legitimizing factor and, over the past several decades, it has become a popular means for authoritarian political leaders or dominant political parties in young or transitional democracies to consolidate their powerbase. Hence, elections have apparently lost their representative value and have, increasingly, been turned into a democratic means to legitimize and institutionalize undemocratic regimes. This has been the most obvious trend in Bangladesh electoral politics over the past decade. Both national and local level elections are engineered in such ways through manipulating electoral laws, the election commission, and the legal system that effectively developed an intended mechanism of preventive representation. A field of electoral competition emerged from such a mechanism where the opposition parties are formally and informally prevented from entering competition in the first place. Technically, this is shown as deliberate nonparticipation by the opposition parties but, in effect, nonparticipation is deliberately orchestrated by the ruling party. An eventual outcome is a government that is free from the parliamentary or legislative opposition, which helps to regularize an authoritarian democracy in the country