Catalytic hollow fiber membranes prepared using layer-by-layer adsorption of polyelectrolytes and metal nanoparticles

Immobilization of metalnanoparticles in hollowfibermembranes via alternating adsorption of polyelectrolytes and negatively charged Au nanoparticles yields catalytic reactors with high surface areas. SEM images show that this technique deposits a high density of unaggregated metalnanoparticles both on the surfaces and in the pores of the hollowfibers. Catalytic reduction of 4-nitrophenol with NaBH4, which can be easily monitored by UV–vis spectrophotometry, demonstrates that the nanoparticles in the hollowfibermembrane are highly catalytically active. In a single pass through the membrane, >99% of the 4-nitrophenol is reduced to 4-aminophenol, but this conversion decreases over time. The conversion decline may stem from catalyst fouling caused by by-products of 4-aminophenol oxidation

Cost-effective policy instruments for greenhouse gas emission reduction and fossil fuel substitution through bioenergy production in Austria

Climate change mitigation and security of energy supply are important targets of Austrian energy policy. Bioenergy production based on resources from agriculture and forestry is an important option for attaining these targets. To increase the share of bioenergy in the energy supply, supporting policy instruments are necessary. The cost-effectiveness of these instruments in attaining policy targets depends on the availability of bioenergy technologies. Advanced technologies such as second generation biofuels, biomass gasification for power production, and bioenergy with carbon capture and storage (BECCS) will likely change the performance of policy instruments. This article assesses the cost-effectiveness of energy policy instruments, considering new bioenergy technologies for the year 2030, with respect to greenhouse gas emission (GHG) reduction and fossil fuel substitution. Instruments that directly subsidize bioenergy are compared with instruments that aim at reducing GHG emissions. A spatially explicit modeling approach is used to account for biomass supply and energy distribution costs in Austria. Results indicate that a carbon tax performs cost-effectively with respect to both policy targets in BECCS is not available. However, the availability of BECCS creates a trade-off between GHG emission reduction and fossil fuel substitution. Biofuel blending obligations are costly in terms of attaining the policy targets

Biofuel production in Europe - Potential from lignocellulosic waste

The objective of this study is to analyze the biofuel potential in Europe from lignocellulosic waste (wood waste and paper and cardboard waste). Ethanol from fermentation and Fischer-Tropsch (FT) diesel from gasification are the two biofuels considered. As those biofuels are not yet commercially available, the optimal locations of the production plants have to be determined. The analysis is carried out with a geographic explicit model that minimizes the total cost of the biofuel supply chain. A mixed integer linear program is used for the optimization. The results show that ethanol production plants are selected in a majority of the studied cases. Ethanol plants are mainly set up in areas with a high heat demand and/or high electricity or heat price, whereas FT diesel production plants are set up in areas where the heat demand is low all year round. A high cost for emitting CO2 as well as high transport fossil fuel prices favor the selection of FT diesel over ethanol production plants. With a CO2 cost of 100 Euros/tCO2 applied, the biofuel production from waste can potentially meet around 4% of the European transport fuel demand

CHP or biofuel production in Europe?

In this study, the opportunity to invest in combined heat and power (CHP) plants and second-generation biofuel production plants in Europe is investigated. To determine the number and type of production plants, a mixed integer linear model is used, based on minimization of the total cost of the whole suply chain. Different policy scenarios are studied with varying values of carbon cost and biofuel support. The study focuses on the type of technology to invest in and the CO2 emission substitution potential, at constant energy prices. The CHP plants and the biofuel production plants are competing for the same feedstock (forest biomass), which is available in limited quantities. The results show that CP plants are preferred over biofuel production plants at high carbon costs (over 50 EUR/tCO2) and low biofuel support (below 10 EUR/GJ), whereas more biofuel production plants would be set up at high biofuel support (over 15 EUR/GJ), irrespective of the carbon cost. Regarding the CO2 emission substitution potential, the highest potential can be reached at a high carbon cost and low biofuel support. It is concluded that there is a potential conflict of interest between policies promoting increased use of biofuels, and policies aiming at decreased CO2 emissions

Dynamic Modeling of Fuel Cells for Applications in Aviation

In the development of more electric aircraft, hydrogen powered fuel cells are one possible solution to progress towards emission reductions in aviation. Currently, there are numerous concepts for integrating fuel cells into future aircraft. The goal of this work was to develop a dynamic fuel cell model for simulations of the powertrain. The Modelica language together with the ThermoFluidStream (TFS) library from the German Aerospace Center (DLR) provided a suitable framework. The fuel cell model takes into account the electrochemical as well as thermodynamic behavior. Hence, the proposed multi-physics model allows simulating the whole fuel cell system, from the hydrogen tank to the electric grid. Under certain simplifications, this enables performing mission simulations of the complete powertrain of future aircraft. As such, polymer electrolyte membrane (PEM) fuel cells and solid oxide fuel cells (SOFC) were considered. The fuel cell models are checked for plausibility in a simple test case against data from the literature. Furthermore, two setups of possible applications are introduced: one for each fuel cell type, which come from two projects. The preliminary control systems of these architectures are presented. Afterwards, the first results of the fuel cell systems are discussed. These results show that the models ran robustly in various environments and operational states. They provided the desired accuracy to predict the behavior of a fuel cell, while maintaining low CPU times and being capable of enabling real-time simulations in the future

Experience with the eCall system in Paramedic Practise

Bakalářská práce se zabývá zkušenostmi se systémem eCall v praxi zdravotnických záchranářů v přednemocniční péči. Cílem práce je zjistit četnost setkání zdravotnických pracovníků s nehodami hlášenými systémem eCall a jejich relevantnost. Jako další cíl práce bylo stanoveno ověření získávaných dat ve výzvě od zdravotnického operačního střediska (ZOS), výhody a nevýhody systému eCall z praxe. V teoretické části je popsáno, co přesně je systém eCall, princip jeho fungování a technické parametry systému. Poté jsou rozebrány důvody vzniku tohoto systému a jeho očekávané benefity. Dále zde je popsána legislativní cesta k zavedení tohoto systému. V praktické části jsou interpretovány výsledky kvalitativních studií, přesněji polostrukturované rozhovory s respondenty, kteří pracující na zdravotnické záchranné službě (ZZS). Získané informace o relevantnosti, četnostech výskytu, dostupnosti informací, výhodách a nevýhodách systému jsou poté analyzovány a graficky znázorněny.The bachelor thesis deals with the experience with the eCall system in the practice of paramedics in pre-hospital care. The aim of the thesis is to determine the frequency of encounters of healthcare workers with accidents reported by the eCall system and their relevance. Another objective of the work was set as the verification of the data obtained in the call from the medical operations centre, the advantages and disadvantages of the eCall system in practice. The theoretical part describes what exactly the eCall system is, its principle of functioning and technical parameters of the system. The reasons for the development of the system and its expected benefits are then discussed. The legislative path to the introduction of this system is also described. In the practical part, the results of qualitative studies, more precisely semi-structured interviews with respondents who work in the emergency medical service (EMS), are interpreted. The information obtained about the relevance, frequency of call, availability of information, advantages and disadvantages of the system are then analysed and graphically illustrated