Considering uncertainty in the optimal energy management of renewable micro-grids including storage devices

This paper proposes a new probabilistic framework based on 2m Point Estimate Method (2m PEM) to consider the uncertainties in the optimal energy management of the Micro Girds (MGs) including different renewable power sources like Photovoltaics (PVs), Wind Turbine (WT), Micro Turbine (MT), Fuel Cell (FC) as well as storage devices. The proposed probabilistic framework requires 2m runs of the deterministic framework to consider the uncertainty of m uncertain variables in the terms of the first three moments of the relevant probability density functions. Therefore, the uncertainty regarding the load demand forecasting error, grid bid changes and WT and PV output power variations are considered concurrently. Investigating the MG problem with uncertainty in a 24 h time interval with several equality and inequality constraints requires a powerful optimization technique which could escape from the local optima as well as premature convergence. Consequently, a novel self adaptive optimization algorithm based on θ-Particle Swarm Optimization (θ-PSO) algorithm is proposed to explore the total search space globally. The θ-PSO algorithm uses the phase angle vectors to update the velocity/position of particles such that faster and more stable convergence is achieved. In addition, the proposed self adaptive modification method consists of three sub-modification methods which will let the particles choosel the modification method which best fits their current situation. The feasibility and satisfying performance of the proposed method is tested on a typical grid-connected MG as the case study.     

Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts

The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal hydroxides. Previous research indicated coagulants were not effective at removing Hg from solution; however these studies used high concentrations of Hg and did not reflect naturally occurring concentrations of Hg. In this study, water collected from an agricultural drain in the Sacramento-San Joaquin Delta was filtered to isolate the dissolved organic matter (DOM) fraction. The DOM was then treated with a range of coagulant doses to determine the efficacy of removing all forms of Hg from solution. Three industrial-grade coagulants were tested: ferric chloride, ferric sulfate, and polyaluminum chloride. Coagulation removed up to 85% of DOM from solution. In the absence of DOM, all three coagulants released IHg into solution, however in the presence of DOM the coagulants removed up to 97% of IHg and 80% of MeHg. Results suggest that the removal of Hg is mediated by DOM-coagulant interactions. There was a preferential association of IHg with the more aromatic, higher molecular weight fraction of DOM but no such relationship was found for MeHg. This study offers new fundamental insights regarding large-scale removal of Hg at environmentally relevant regarding large-scale removal of Hg at environmentally relevant concentrations.     

Numerical and experimental studies on unitized regenerative proton exchange membrane fuel cell

Increasing energy need and running out of fossil-based fuels direct us to renewable energy resources. Although hydrogen is not an energy source by itself, it is an energy carrier with a high specific heat capacity. As it is used as fuel in unitized regenerative PEM fuel cells, water is separated in electrolyzer mode and stored by producing hydrogen when there is no need for energy. In this study, performance tests on the unitized regenerative PEM electrolyzer/fuel cell were carried out and numerical modelling has been performed. The validity of the developed model was confirmed by the results of the experimental study. Before starting the performance tests, the cell's leakproofness tests were carried out, and the appropriate torque force was optimized, reducing the contact resistance that causes performance loss. The material selection of the cell components and corrosion-resistant materials that can operate in both electrolyzer and fuel cell modes were preferred.In this study, 0.019 slpm of hydrogen and 0.0095 slpm of oxygen gas is produced in the electrolyzer mode, while a power density of 0.353 W/cm² is obtained in the fuel cell mode at 80 °C, from a unitized regenerative PEM fuel cell with a 5 cm² active area, whose cell elements are combined with a 3 Nm clamping torque by using 12 bolts.     

电力变压器蒸发冷却装置FC液位监控系统

介绍电力变压器蒸发冷却装置的液位控制系统,该系统以嵌入式以太网芯片为核心构成网络终端．实现了冷却介质FC液位的远程监测调节．     

离子修饰纳米Pt的合成及其在FC中的应用

介绍了Nation聚合物作为修饰离子,合成具有原位质子导电能力的纳米Pt颗粒;TEM分析显示：Pt颗粒的平均粒径为4nm,颗粒之间界限明显,分散状态良好;将这种离子导体修饰的纳米Pt沉积到纳米碳管(CNTs)表面作为质子交换膜燃料电池催化电极,纳米碳管相互缠绕在催化层形成交联的电子通道。实验结果表明：Pt颗粒表面具有良好的质子、电子和气体通道,单电池具有良好的输出功率,达到2．8W／mg。     

SrRuO3铁磁性能研究

测量了烧结SrRuO3的零场冷却和加场冷却磁化强度和交流磁化率。随外加直流偏场的增加,交流磁化率与温度关系曲线向低温方向移动。继续增加直流偏场,一个峰分裂为两个峰,其中低温下的峰继续向低温方向移动,另一个高温处的峰却向高温方向移动。在不同频率下测量零偏场下的交流磁化率,随频率增加峰值减小,但峰的位置并没有像以前报道得那样向高温方向移动。可见,烧结SrRuO3并没有显示自旋玻璃行为,而是普通铁磁体。     

Health-promoting substances and antioxidant properties of Opuntia sp. fruits. Changes in bioactive-compound contents during ripening process

Several Opuntia cactus fruits of different pulp colours from Argentina were studied at their physiological mature states. Analyses of these fruits showed very variable total soluble solid values and ascorbic acid contents ranging from 0.26 to 0.48 mg/g. Total phenolic compounds contents were between 0.54 and 1.2 mg of gallic acid/g, respectively. Purple Opuntia spp., dark purple Opuntia ficus-indica and orange Opuntia megacantha presented the highest levels amongst the samples studied. The antioxidant activity of Opuntia fruits was very variable and presented vitamin C equivalent values (VCEAC) between 0.25 and 0.57 mg/g. Purple Opuntia ficus-indica showed the highest antiradical ability. Besides, the antioxidant activity, ascorbic acid and phenolic compound contents in yellow and orange Opuntia megacantha fruits were monitored in different stages during their ripening process. Concentration changes of betalains and chlorophylls comparing skin and pulp and other physicochemical parameters were also measured in these fruits.     

Effect of anodes-cathodes inter-distances of HHO fuel cell on gasoline engine performance operating by a blend of HHO

Control emission pollution associated with oil combustion is a major concern of researchers worldwide. A blend of HHO has been introduced to the combustion elements to reduce emission and drive the combustion reaction toward stoichiometric condition. HHO fuel production unit based on an electrolysis process has been designed and built with an ability to alter Anode-Cathode plate's inter-distances and integrated to Honda G 200 (197 cc single cylinder engine). The gap between the plates was adjusted to 3, 5, 7 and 10 mm. Tests reveal that mixing HHO, air, and gasoline cause an enhancement in engine performance and emissions. The emission tests have been done with varying the engine speed and preserve the electrolyte concentration and temperature. The results show that enhancement in combustion characteristics is strongly affected by the gap between cell plates. The maximum produced power and minimum fuel consumption were associated with the case of 10 mm cathode-anode plates distance where hydrocarbons (HCs) and carbon monoxide emissions have been reduced to about 40% at different operating speeds. Whereas, 5 mm gap case has the highest impact on emission reduction.     

Fuel cell vehicles: State of the art with economic and environmental concerns

Hydrogen fueled fuel cell vehicles (FCVs) will play a major role as a part of the change toward the hydrogen based energy system. When combined with the right source of energy, fuel cells have the highest potential efficiencies and lowest potential emissions of any vehicular power source. As a result, extensive work into the development of hydrogen fueled FCVs is taking place. The aim of this paper is to highlight some of the research and development work which has occurred in the past five years on fuel cell vehicle technology, with a focus on economic and environmental concerns. It is observed that the current efforts are divided up into several parts. The performance, durability, and cost of fuel cell technology continue to be improved, and some fuel cells are currently ready to be mounted on vehicles and tested. Environmental and economic assessments of the entire hydrogen supply chain, including fuel cell end-use, are being carried out by groups of researchers around the world. It is currently believed that fuel cells need at least five more years of testing and improvement before large scale commercialization can begin. Economic and environmental analyses show that FCVs will likely be both economically competitive and environmentally benign. Indeed, the transition of the transportation sector to the use of hydrogen FCVs will represent one of the biggest steps toward the hydrogen economy.