384 research outputs found

    Preparation of exfoliated Mica using phlogophite

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    Mica is a generic term for long group of poly-silicates mineral with a unique structure. Mica can be found in nature in the form of sheets connected together by surface force between by layers. Mica has often been used for a wide variety of economical uses including the electronic industry, paints and fillers. The expansion behavior of the natural mica has been studied for industrial use of exfoliated mica. The development of exfoliated mica technology was initiated with a two prolonged approach namely to develop cheaper value added products. Natural mica (Phlogophite) acquired from Feldspar mine at Rattota, Matale, Sri Lanka. The selected mica samples were washed and crushed by using an agate mortar and separated for few minutes to the particle size of 63um and approximately separated in to l-2mm particle size by using a mechanical sieve-shaker. Lithium Nitrate was used for chemical intercalation with mica. The expansion factor (degree of expansion) was determined using the ratio between original volume and maximum volume which was measured. Characterization of the exfoliated mica was carried out with X-ray powder diffractometry (Cu K a, Philips X-Ray generator) and The SEM studies are performed on a JSM 6400 scanning electron microscope. Thickness of the intercalate layers, interplanar distances were studied using 001 diffraction pattern. The exfoliation behavior of the natural graphite mainly depends on the particle size & shape and experimental conditions such as temperature and further it depends on the order of the crystal lattice, the secondary structure; size and shape of the particles, the amount of gangue minerals with the mica and the technological pretreatment of the mica

    High tech applications of Sri Lankan vein graphite; future trends

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    Minerals can play a pivotal role in determining and improving economic performance and the quality of life. Sri Lanka has been well known for processing a variety of economically useful vein type graphite, which are mainly being exported as cheap raw materials but played a main role in modern manufacturing industry internationally. Natural graphite (NG) is an attractive material for Li-ion batteries (LIB) because of its high capacity (372 mAh/g) and low working voltage yields with high energy density (Wh/kg). Introducing performance enhanced cheaper NG electrodes for LIB will definitely reduce their cost and improve the capacity. The objective of the research is to introduce cost effective, time saving, highly economical and more convenient method to convert Sri Lankan vein graphite directly in to the battery grade anode material for Li-ion batteries. Powdered natural graphite sample was treated with mixture of HF, HNO3 and H2SO4 acids at 120 0C till the evaporation of mixture. Results of the Carbon content measurements (ASTM – 561), XRD, SEM and FTIR evidenced that the acid digestion method was successfully purified the Sri Lankan vein graphite over 99.9%. In the preliminary chemical purification study done by acid leaching, revealed the possibility of purifying local graphite using mineral acids with low concentrations at low temperature. It further indicated the ability of surface modification of the vein graphite by mild oxidation. The preliminary investigations on Sri Lankan graphite for rechargeable Li-ion battery (LIB) application and graphite oxide (GO) synthesis has revealed the potentiality of this cheap local mineral for technological applications. Further, it indicated the worthiness of conducting further investigations on the vein graphite to enhance the purity and the properties (homogeneity and particle morphology, electrical conductivity ... etc.) appropriate for the expected high tech applications

    Distributed Web Service Coordination for Collaboration Applications and Biological Workflows

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    In this dissertation work, we have investigated the main research thrust of decentralized coordination of workflows over web services. To address distributed workflow coordination, first we have developed “Web Coordination Bonds” as a capable set of dependency modeling primitives that enable each web service to manage its own dependencies. Web bond primitives are as powerful as extended Petri nets and have sufficient modeling and expressive capabilities to model workflow dependencies. We have designed and prototyped our “Web Service Coordination Management Middleware” (WSCMM) system that enhances current web services infrastructure to accommodate web bond enabled web services. Finally, based on core concepts of web coordination bonds and WSCMM, we have developed the “BondFlow” system that allows easy configuration distributed coordination of workflows. The footprint of the BonFlow runtime is 24KB and the additional third party software packages, SOAP client and XML parser, account for 115KB

    A Confirmatory Investigation of the Factors Influencing the Cloud Adoption in Local Government Organisations in Australia.

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    The purpose of this paper is to discuss major factors of two well-known theoretical frameworks namely Technology-Organization-Environment (TOE) and Technology Acceptance Model (TAM), and examine how those factors could influence the Organizational decision on Cloud technology adoption. The research underlining was carried out using quantitative research methodology based on a survey questionnaire distributed to IT professionals across Australia. The survey questionnaire was developed based on 12 hypotheses and 24 indicator variables. Around 200 responses were analysed by using two-tier approach (a) confirmatory factor analysis to confirm the reliability and validity of the latent variables, and (b) analysis of the structural model to confirm or reject the hypothesis. The final analysis of the results has revealed that only 8 hypotheses are significant and can be adopted. Furthermore, results have revealed that 4 hypotheses have a non-significant impact on the proposed framework and can be rejected from the framework

    Manufacturing of laterite bricks as an environmental friendly alternative row material

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    There is a deficiency of row materials for housing in Sri Lanka because of population growth. So there is an unfulfilled demand for traditional row materials such as river sand and clay. Serious environmental problems are caused because of over excavation of above row materials. To minimize the environmental problems, it should be focused towards low cost and environmental friendly alternative row materials which are occurring in sufficient amount in Sri Lanka. In order to fulfill the demand of row material for housing and other constructions, laterite soil can be used with quarry dust and cement as additives. Particle size distribution of the laterite was poorly graded and addition of quarry dust corrected this deficiency. The bricks which are made from laterite and quarry dust mixture can be stabilized using low amount of cement while achieving required compressive strength for walling. This material mixture is more economical and environmental friendly for bricks production

    Long term solution for flood in Malala Lagoon, Hambantota

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    The lagoon systems play a major role in maintaining the balance of the organisms as well as the physical environment. The lagoon resources were misused due to unavailability of a proper management plan, environment pollution and lagoons converted into lands and polluted due to natural disasters. Therefore, the research was focused to find the vulnerable area and vulnerable communities to the flood; to carry out a scientific study to assess the hydrological, ecological, and biological impacts of the increased inflow into the lagoon; to study how the above problems affect the fishing community who depend on the lagoon for their livelihood , the farmers community who rely on paddy fields of vulnerable area and the other organisms who depend on the lagoon and surrounding area for their livelihoods; to find a long term solution for the flood in Malala and Embilikala lagoons, situated inside the Bundala conservation area of Hambanthota district. Considering the biological environment and the inundation affects the divert water directly to the sea from a canal through the reserved area is the best alternative to be acceptable by both farming and fishing communities and the environment

    Chemical intercalation of potassium into natural graphite

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    The potassium binary graphite intercalation compound [GIC (K)] was prepared using classical double bulb chemical method and compared with different types of natural vein graphite from Sri Lanka and natural flake graphite of Madagascar. The first stage GIC (K) was always obtained for natural vein and flake graphite. These result indicated that the potassium intercalation does not depend on the graphite‘s physical texture or their morphology

    Natural hazards and vulnerability in South Eastern coastal region of Sri Lanka: a case study in Maruthamunai area

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    Sri Lanka has experienced several disasters including cyclone, typhoons, tornadoes, flood, drought, landslide, epidemics, lightening, accident related disaster and tsunami. Tsunami occurred on 24th December 2004 which was the biggest catastrophic disaster in Sri Lanka, affected entire north, east and south coastal belt and killing people and destroying properties. Maruthamunai in Ampara district in the south eastern coastal region was severely affected than other coastal regions of Sri Lanka. A questionnaire survey was carried out on hazard awareness in Maruthamunai area. The purpose of this study was to identify the community perception on hazards and vulnerability by mapping at community level. The study describes the factors or constraints of economic, social, physical or geographic nature, which reduce the ability to prepare and to cope with the impact of hazards. Throughout the study it was found that people are not aware about all the hazards around them and hazard mapping. More than 95 percent of residents lacked tsunami knowledge prior to the 2004 tsunami. People consider the reason for flooding as heavy rainfall and inadequate drainage system, but not aware that water disposal into marshy lands too contribute to flood the area. All the people who are living in the coastal area are vulnerable to the hazards, and it is recommended to educate the people on disaster and its management and also to develop a land use plan by authorities with the support of the community. Adequate drainage network systems have to be developed and implemented by the local authority

    An evaluation of the impact of school-based resource management and formula funding of schools on the efficiency and equity of resource allocation in Sri Lanka

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    Issues of school financing and school-based resource management (SBRM) in Sri\ud Lanka were discussed during the past two decades, and actions were taken to minimize\ud resource allocation disparities; nonetheless the unequal distribution of resources to\ud schools was still evident. Since 2000, the government of Sri Lanka, with the financial\ud assistance of the World Bank, has employed a norm-based unit cost resource\ud allocation mechanism (NBUCRAM) as a new policy for the formula funding of\ud schools (FFS), notably for ensuring equity in the provision of learning resources. The\ud government implemented two types of SBRM programme: 'strengthened basic'\ud SBRM, and the 'extension' of SBRM, to improve efficiency. Strengthened basic\ud SBRM was for all public schools to receive cash allocated by formula for spending on\ud learning materials, consisting of consumables and perishables (excluding chemicals).\ud The extension of SBRM was piloted to enable schools to also decide on the purchase\ud of inexpensive equipment (capital expenditure) to support teaching and learning. This\ud thesis attempts to evaluate the impact of SBRM and FFS on the efficiency and equity\ud of resource allocation in Sri Lanka. The required data were gathered using\ud questionnaires, semi-structured interviews and documentary analysis.\ud Longitudinal and c ross-sectional d ata reveal t hat b efore the introduction oft he new\ud mechanism, there were vast disparities in school funding for learning resources. At\ud present, schools have adopted a rational and transparent mechanism of allocation, to\ud ensure procedural and distributional equity. Qualitative interpretative data show that\ud since 2000 this has contributed to minimizing the gaps among and within the schools.\ud Evidence shows a substantial improvement in real per-pupil expenditure on learning\ud resources, compared to the previous three years. Legal support for resourcing\ud disadvantaged schools is another principal impact of NBUCRAM. The evidence of\ud school revenues highlights socio-economic factors as challenges to equity.\ud Constitutionally, education is free for all children, although it is still expensive for\ud low-income families. The system has established a national policy for funding schools,\ud although more consideration of adequacy criteria is needed. The present formula\ud funding system does not fully address some essential issues (i.e. pupils with special\ud educational needs, lack of identification of disadvantaged children and schools, and of\ud adequacy criteria) in relation to resourcing schools. It is impossible to achieve a perfect solution, since equity is a subjective issue; but it is essential to reduce the\ud disparities in resourcing schools. Moreover, it is crucial to apply procedural and\ud distributional (including horizontal and vertical) equity principles, as well as adequacy\ud criteria.\ud Longitudinal and cross-sectional data further suggest that strengthened basic SBRM is\ud a preliminary step in the delegation of power and decision-making authority to schools\ud to purchase consumable learning materials (recurrent expenditure) compared to basic\ud SBRM and non-SBRM regimes. The extension of SBRM is the way to delegate\ud extensive power and decision-making authority to schools, beyond strengthened basic\ud SBRM to purchase inexpensive capital learning resources (capital expenditure).\ud Longitudinal, quasi-experimental and cross-sectional data suggest that both\ud programmes have led to increasing participation in decision-making and to\ud improvement in the process of acquisition of learning resources. Expenditure per pupil\ud for learning resources, both materials and equipment, considerably improved under\ud these two programmes, a result of efficiency incentives. In the extension of SBRM,\ud pilot schools get more expenditure per pupil for inexpensive capital learning\ud equipment than non-pilot schools. Non-pilot schools still depend upon centralized\ud provisions. While these two programmes show some successes, some weaknesses are\ud also evident. Both SBRM policies do not identify the relationships between\ud educational inputs and outputs, access to local market, institutional capacities, and\ud regional imbalances.\ud NBUCRAM and the two SBRM practices are intervention policies meant to improve\ud equity and efficiency significantly, although at present the improvement seems to be\ud insufficient

    A Methodology for Engineering Collaborative and ad-hoc Mobile Applications using SyD Middleware

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    Today’s web applications are more collaborative and utilize standard and ubiquitous Internet protocols. We have earlier developed System on Mobile Devices (SyD) middleware to rapidly develop and deploy collaborative applications over heterogeneous and possibly mobile devices hosting web objects. In this paper, we present the software engineering methodology for developing SyD-enabled web applications and illustrate it through a case study on two representative applications: (i) a calendar of meeting application, which is a collaborative application and (ii) a travel application which is an ad-hoc collaborative application. SyD-enabled web objects allow us to create a collaborative application rapidly with limited coding effort. In this case study, the modular software architecture allowed us to hide the inherent heterogeneity among devices, data stores, and networks by presenting a uniform and persistent object view of mobile objects interacting through XML/SOAP requests and responses. The performance results we obtained show that the application scales well as we increase the group size and adapts well within the constraints of mobile devices
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