36 research outputs found

    Thermogravimetric study of Chlorella vulgaris for syngas production

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    The present study investigates the thermal degradation behavior of Chlorella vulgaris using a thermogravimetric analyzer (TGA) to explore application as feedstock for syngas production. The biomass was heated continuously from room temperature to 1000 °C at different heating rates (5, 10 and 20 °C min− 1) under N2/air conditions at a constant flow rate of 25 mL min− 1. Experimental results showed that the combustion process of C. vulgaris can be divided into three major phases; (1) moisture removal, (2) devolatilization of carbohydrates, protein and lipids and (3) degradation of carbonaceous material. A degradation rate of 80% was obtained at the second phase of the combustion process in the presence of air whilst a degradation rate of 60% was obtained under N2 atmosphere at the same phase. The biomass was further gasified for syngas production using a Temperature Programmed Gasifier (TPG). The effect of three different process variables, temperature, microalgal loading, and heating rate was investigated. The maximum H2 production was found at 800 °C temperature with a biomass loading of 0.5 g. No significant effect of heating rate was observed on H2 production. The activation energy values, based on the Kissinger method, were evaluated to be 45.38 ± 0.5 kJ mol− 1 (1st stage), 61.20 ± 0.5 kJ mol− 1 (2nd stage) and 97.22 ± 0.5 kJ mol− 1 (3rd stage). The results demonstrate a significant potential for the utilization of the microalgae biomass as feedstock for large-scale production of syngas via gasification

    Thermochemical conversion of microalgal biomass for biofuel production

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    Reliable and sustainable energy supply is critical to effective natural resource management, and it encompasses functioning efficiency of energy resources as well as socio-economic and environmental impact considerations. The complete reliance on fossil fuels is recognized as unsustainable throughout the world, and this is due to, amongst others, the rapid declining of fossil fuel reserves and the emission of significant quantities of greenhouse gases associated with their production and combustion. This has resulted in escalating interest in research activities aiming to develop alternative and somewhat carbon neutral energy sources. Algal biofuels, so called third generation biofuels, appear to be promising in delivering sustainable and complementary energy platforms essential to formulate a major component of the renewable and sustainable energy mix for the future. Algal biomass can be converted into various portfolios of biofuel products, such as bio-hydrogen, biodiesel, bioethanol and biogas, via two different pathways: biochemical and thermochemical pathways. Thermochemical conversion is considered as a viable method to overcome the existing problems related with biochemical conversion such as lengthy reaction time, low conversion efficiency by microbes and enzymes, and high production costs. This paper discusses process technologies for microalgae-to-biofuel production systems, focusing on thermochemical conversion technologies such as gasification, pyrolysis, and liquefaction. The benefits of exploiting upstream microalgal biomass development for bioremediation such as carbon dioxide mitigation and wastewater treatment are also discussed

    The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

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    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    Essential elements for Radio Frequency Identification (RFID) adoption for industry 4.0 Smart Manufacturing in Context of Technology-Organization-Environment (TOE) Framework – a review

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    Automatic identification and data collection provides an ideal basis for Industry 4.0 Smart Manufacturing. The manufacturing sectors, involving a wide spectrum of physical and digital world, are functioning in extremely challenging environment. To optimize production efficiency, the incorporation of automated data collection technologies such as Bar Code and Radio Frequency Identification (RFID) is essential. Both these technologies have a great overlap in terms of industrial applications and no study reviews the existing literature in this regard. Therefore to cope up this matter, a systematic literature review has been conducted in which the technologies have been studied and compared, followed by the detailed discussion under various contexts of Technology-Organization-Environment (TOE) Framework. It has been observed that both these technologies have been employed in various manufacturing domains such as lean manufacturing, inventory management and production planning. However, it has been observed that RFID technology carried technological superiority over Bar Code technology. The systems utilizing the former are highly reliable, exquisitely capable and perform excellent in case of automation. However, issues such as high capital costs and increased level of technical complexity are few dilemmas in case of adopting RFID based systems. In addition to that, the implementation of RFID systems is complemented by certain essential features of TOE framework, which can help to elevate competitiveness and efficiency of an organization regarding tracking and identification of assets and inventory

    A systematic literature review of software help systems limitations

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    Software help systems are content viewers which are integrated into operating systems designed to assist users in learning to use software applications. Help systems provide information directly from the developers of software applications. Help systems have been neglected for a while and often replaced by unofficial resources. This research aims to review the limitations of the current help systems and find the reasons why users are less likely to use the integrated help systems to obtain information. A systematic literature review (SLR) was conducted to collect data from all studies that investigate the limitations of help systems. The data collected were statistically analyzed to draw conclusions on the probable causes. The SLR reviewed 602 studies from 2010 to 2017 from nine online databases. 13 studies matched the selection criteria and were therefore included in the study. The data asserted the fact that users rarely use the integrated help systems and often preferred alternative methods. The analysis pointed at three major limitations of the help systems that caused users to underutilize the systems. These limitations include the inability of the help systems to adapt to users’ learning styles, difficulty in locating information, and overall ineffectiveness of the help systems. Addressing these limitations in help systems will help create a system that can reduce the need for unofficial resources, and therefore reducing the risks of cyber-attacks
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