47 research outputs found

    Modelling Calcium Signal Intensity Difference Between Cells

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    Cell signaling involves the transmission of a signal from a sending cell to a receiving cell. Calcium ions (Ca2+) are a widely used type of messenger. In this study the evolution over time of calcium signal intensity and how these evolutions depend on the four groups of cells of subjects with different health condition was investigated. A longitudinal data analysis based on 110 subjects was used and to account non-linearity and correlated nature of the data, non-linear mixed model was used. Based on the exploratory data analysis result supported with CurveExpert professional software the model used has sigmoid structure. From the result, the rate of change of average signal intensity was nearly 0.033 and the time at which the rate of change of average calcium signal intensity reaches its maximum (i.e. the inflection point) was nearly 198 seconds. Furthermore, there were statistically significant differences in average calcium signal intensity between the groups. It is also observed that significant differences between mild hyperplasia and benign tumor patient’s cells and also between malignant tumor and healthy subject’s cells. Keywords: Calcium, Cell Signaling, Non Linear Mixed Model, Random Effect, Signal Intensit

    Bio-Hydrogen Production from Wastewater: A Comparative Study of Low Energy Intensive Production Processes

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    Billions of litres of wastewater are produced daily from domestic and industrial areas, and whilst wastewater is often perceived as a problem, it has the potential to be viewed as a rich source for resources and energy. Wastewater contains between four and five times more energy than is required to treat it, and is a potential source of bio-hydrogen—a clean energy vector, a feedstock chemical and a fuel, widely recognised to have a role in the decarbonisation of the future energy system. This paper investigates sustainable, low-energy intensive routes for hydrogen production from wastewater, critically analysing five technologies, namely photo-fermentation, dark fermentation, photocatalysis, microbial photo electrochemical processes and microbial electrolysis cells (MECs). The paper compares key parameters influencing H2 production yield, such as pH, temperature and reactor design, summarises the state of the art in each area, and highlights the scale-up technical challenges. In addition to H2 production, these processes can be used for partial wastewater remediation, providing at least 45% reduction in chemical oxygen demand (COD), and are suitable for integration into existing wastewater treatment plants. Key advancements in lab-based research are included, highlighting the potential for each technology to contribute to the development of clean energy. Whilst there have been efforts to scale dark fermentation, electro and photo chemical technologies are still at the early stages of development (Technology Readiness Levels below 4); therefore, pilot plants and demonstrators sited at wastewater treatment facilities are needed to assess commercial viability. As such, a multidisciplinary approach is needed to overcome the current barriers to implementation, integrating expertise in engineering, chemistry and microbiology with the commercial experience of both water and energy sectors. The review concludes by highlighting MECs as a promising technology, due to excellent system modularity, good hydrogen yield (3.6–7.9 L/L/d from synthetic wastewater) and the potential to remove up to 80% COD from influent streams

    An Experimental Investigation of Hydrogen Production Through Biomass Electrolysis

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    This work investigated hydrogen production from biomass feedstocks (i.e. glucose, starch, lignin and cellulose) using a 100 ml h-type proton exchange membrane electrolysis cell. Biomass electrolysis is a promising process for hydrogen production, although low in technology readiness level, but with a series of recognised advantages: (i) lower temperature conditions (compared to thermochemical processes), (ii) minimal energy consumption and low-cost post-production, (iii) potential to synthesis high volume H2 and (iv) smaller carbon footprint compared to thermochemical processes. A Lewis acid (FeCl3) was employed as a charge carrier and redox media to aid in the depolymerisation/oxidation of biomass components. A comprehensive analysis was conducted, measuring the H2 and CO2 emission volume and performing electrochemical analysis (i.e. linear sweep voltammetry and chronoamperometry) to better understand the process. For the first time, the temperature's influence on current density and H2 evolution was studied under a temperature ranging from ambient temperature (i.e., 19 °C) to 80 °C. The highest H2 volume was 12.1 mL, which was produced by FeCl3-mediated-electrolysis of glucose at ambient temperature, which was up to two times higher than starch, lignin and cellulose at 1.20 V. Of the substrates examined, glucose also showed the maximum power to H2 yield ratio of 30.99 kWh/kg. Results show that hydrogen can be produced from biomass feedstock at ambient temperature when Lewis acid (FeCl3) is employed and with a higher yield rate and a lower electricity consumption compared to water electrolysis

    Technoeconomic and Environmental Assessment of Biomass Chemical Looping Gasification for Advanced Biofuel Production

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    Chemical looping gasification is a promising biomass conversion technology that could produce sustainable liquid transportation fuels on a large scale to reduce fossil fuel dependency. The current paper examines the technical, economic, and environmental performance of a biomass-to-liquid (BtL) process based on chemical looping gasification and Fischer-Tropsch synthesis. Two biomass feedstocks, i.e., pine forest residues and wheat straw, are selected for assessing the complete BtL production chain. The results of process simulations showed that both biomass types are suitable gasification feedstocks, with an overall energy efficiency of 53% and 52% for pine residues and wheat straw, respectively. The economic results show that the breakeven selling prices (BESP) are €816 and €781 per m3 for the pine forest residues and wheat straw pellets, respectively. However, if low-grade excess heat valorisation and CO2 credits are considered, the BESPs could meet or become lower than the target value of €700 per m3, making the BtL plant competitive with other biofuel plants. The CO2 avoidance cost is estimated at €74.4/tCO2 for pine residues and €61.3/tCO2 for wheat straw, when replacing fossil fuels. The results of the life cycle assessment study showed that the produced biofuels fulfil the requirements of the EU Renewable Energy Directive II, achieving the reduction in greenhouse gases emissions of up to 79% without carbon capture and storage (CCS) and up to 264% with CCS compared to fossil fuels

    Comparative performance of sustainable anode materials in microbial fuel cells (MFCs) for electricity generation from wastewater

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    Microbial fuel cells (MFCs) are a promising technology to generate electricity from wastewater and reduce the organic content. Whilst there has been a significant enhancement in MFC efficiency arising from the introduction of novel materials and cell designs, challenges remain with respect to the performance, cost, and sustainability of anode materials. This paper reports the development of single chamber MFCs with a focus on novel, cost-effective, and recycled carbon-based anode materials, including Recycled Water Filter Block/Powder (RWFB/RWFP), Recycled Chopped Carbon Fibre (RCCF), Carbon Felt (CF) and Graphite Flexible powder (GFG). Anodes prepared from GFG were shown to provide high power density (342.8 mW/m2), followed by RCCF, CF, RWFP, RWFB and CF (77.6, 71.8, 59.0 and 57.9 mW/m2, respectively). Chemical Oxygen Demand (COD) reduction was measured initially and at day 30, with GFG anodes observed to remove 83% of the initial load, compared to RCCF, RWFB, RWFP and CF anodes, where COD reductions of 69%, 61%, 65% and 73% were observed, respectively. Electrochemical analysis and biofilm imaging confirmed recycled materials were colonised by microorganisms and performed to high standards. GFG offers significant promise as an anode material, with excellent performance supported by a reduction in capital cost of up to 90% in comparison to CF. The use of recycled carbon material as MFC anodes shows promise, but requires additional work to improve the stability and durability of systems to permit scale-up
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