29 research outputs found

    Economic feasibility of small wind turbines for domestic consumers in Egypt based on the new feed-in tariff

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    This paper provides an overview of the wind power potential at different regions in Egypt, along the Mediterranean and Red Sea, and the Western desert. A further technical and economic assessment is conducted for the electricity generation with 8 different small wind turbines at 17 locations. The annual electricity generation from selected wind turbines is evaluated. The obtained data are presented and discussed investigating the net present value and the payback period analyzing the profitability of selected wind turbines. The dependence of the turbine profitability from the feed-in tariff is specifically addressed

    Experimental measurement technique for the assessment of the fuel crossover diffusion coefficient in the membrane electrode assembly of a direct methanol fuel cell

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    Since the cross-over still seems to be the main issue of the direct methanol fuel cells, an experimental evaluation of the diffusive cross-over is performed. Even if the relationship of the rate through the membrane is the sum of the three terms of diffusive, osmotic and drag, the diffusive component is also present at open circuit lowering the Open Circuit Voltage of the single cell up to 50 % with respect to the Nernst potential. The goal of the research is to develop a direct measurement technique of the crossover that can provide the effective values of the parameters that characterize the membrane electrode assembly. The experimental set up consists in the pressure, flow and temperature control and acquisition using Labview. A sensitive analysis for three values of temperatures at 60°C, 65°C and 70°C is performed for first. Then, a small overpressure was generated in the cathode side by a valve located at the cathode outlet. A set of pressure were analysed for 0, 30 and 90 mbar of overpressure at the cathode. The tested fuel cell has a commercial Nafion 117 membrane and carbon paper gas diffusion layers 700 cm2 large. Preliminary results show that the differential concentration term seems to be significantly larger than the osmotic term. The diffusion coefficients are useful for fuel cell modelling and for the calibration of the operating conditions in the sensor less DMFC systems

    Assessment of CO2 bubble generation influence on direct methanol fuel cell performance

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    Fuel cells fed directly by liquid methanol represent a class of suitable devices for supply portable small power applications. To become a market attractive technology some issues must be properly addressed and resolved. The presence of gaseous CO2 generated in the anode channels is the main issue as it can hinder the free surface of the Gas Diffusion Layer reducing the active area and the methanol flux through the porous media towards the catalyst layer. In this work the influence of gas phase fraction on the cell performance and the relationship with the operating parameters such as air flow rate, methanol-water solution flow rate and current density is investigated. The characterization of CO2 bubbles flow in the anode channel is carried out

    Economic Feasibility of Small Wind Turbines for Domestic Consumers in Egypt Based on the New Feed-in Tariff

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    Abstract This paper provides an overview of the wind power potential at different regions in Egypt, along the Mediterranean and Red Sea, and the Western desert. A further technical and economic assessment is conducted for the electricity generation with 8 different small wind turbines at 17 locations. The annual electricity generation from selected wind turbines is evaluated. The obtained data are presented and discussed investigating the net present value and the payback period analyzing the profitability of selected wind turbines. The dependence of the turbine profitability from the feed-in tariff is specifically addressed

    Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

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    Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

    Development of Improved Passive Configurations of DMFC with Reduced Contact Resistance

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    Abstract The Direct Methanol Fuel Cell (DMFC) represents today an appropriate solution for powering portable applications and small electronic devices, due to: 1) its compactness, 2) the high power density when compared with batteries and 3) the facility in transporting proper quantities of fuel (generally a liquid mixture of methanol and water). In order to further reduce the DMFCs size, passive configurations without external pumps and auxiliary devices are actively studied. Oxygen is supplied from the surrounding air while methanol-water solution is stored into a built-in tank in contact with the gas diffusion layer (GDL) that is constantly kept wet. Such configurations have a lower current density, roughly around 10÷30 mA/cm2, when compared with active configuration (40÷80 mA/cm2). It is then important to improve the baseline performance (power and efficiency) of such cells by optimizing all system components. Here we aim at reducing the effects of the contact resistance between GDL and current collectors by carrying out a sensitivity analysis on a number of relevant cells parameters such as:. assembly shape, gaskets, current collectors materials and open ratios. Analysis will be carried out at different molar concentrations (1 to 4 M) of the water-methanol solution used as fuel

    techno economic analysis of in situ production by electrolysis biomass gasification and delivery systems for hydrogen refuelling stations rome case study

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    Abstract Starting from the Rome Hydrogen Refuelling Station demand of 65 kg/day, techno-economics of production systems and balance of plant for small scale stations have been analysed. A sensitivity analysis has been done on Levelised Cost of Hydrogen (LCOH) in the range of 0 to 400 kg/day, varying capacity factor and availability hours or travel distance for alkaline electrolysers, biomass gasification and hydrogen delivery. As expected, minimum LCOH for electrolyser and gasifier is found at 400 kg/day and 24 h/day, equal to 12.71 €/kg and 5.99 €/kg however, for operating hours over 12 and 10 h/day the differential cost reaches a plateau (below 5%), for electrolyser and gasifier respectively. For the Rome station design, 160 kWe of electrolysers 24 h/day and 100 kWth gasifier at 8 h/day, LCOH (11.85 €/kg) was calculated considering the modification of the cost structure due to the existing equipment, which is convenient respect the use of a single technology, except for 24 h/day gasification

    Conditional displacement operator for traveling fields

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    We show that the conditional displacement operator U^CD=exp[b^b^(βa^βa^)]\hat{U}_{CD}=\exp [\hat{b}^{\dagger}\hat{b}(\beta \hat{a}^{\dagger}-\beta ^{\ast}\hat{a})] acting upon an arbitrary state of traveling waves can be well approximated by the action of a Kerr medium placed between two beam splitters whose respective second ports are fed by highly excited coherent states. Applications to the generation of nonclassical states and measurement of Wigner function of arbitrary states are also considered

    Effectiveness of patients’ involvement in a medical and nursing pain education programme: a protocol for an open-label randomised controlled trial including qualitative data

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    Introduction Pain is a multidimensional experience that varies among individuals and has a significant impact on their health. A biopsychosocial approach is recommended for effective pain management; however, health professionals’ education is weak on this issue. Patient involvement is a promising didactic methodology in developing a more holistic perspective, however there is a lack of reliable evidence on this topic. The aim of the present study is to evaluate the effectiveness of patient involvement in pain education in undergraduate medicine and nursing students. Methods and analysis An open-label randomised controlled trial including qualitative data will be conducted. After an introductory lesson, each student will be randomly assigned to the intervention group, which includes an educational session conducted by a patient–partner along with an educator, or to the control group in which the session is exclusively conducted by an educator. Both sessions will be carried out according to the Case-Based Learning approach. Primary outcomes will be students’ knowledge, attitudes, opinions and beliefs about pain management, whereas the secondary outcome will be students’ satisfaction. The Pain Knowledge and Attitudes (PAK) and Chronic Pain Myth Scale (CPMS) will be administered preintervention and postintervention to measure primary outcomes. Students’ satisfaction will be measured by a questionnaire at the end of the session. Two focus groups will be conducted to evaluate non-quantifiable aspects of learning. Ethics and dissemination The protocol of this study was approved by the independent Area Vasta Emilia Nord ethics committee
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