Thin film transformer and its analysis by integral equation method

We propose a thin film transformer for small electronic devices, and apply the integral equation method to analyze this transformer. Both the primary and secondary coils of the film transformer are arranged coaxially on the layer and multiply laminated. The operation principal of the transformer is based on the skin effect and the mutual effect between the coils at high frequency. Because of the coaxially arranged coils, the magnetic field of the transformer can be modeled with an axisymmetric assumption. Using the model, we evaluate the electromagnetic field and calculate the lumped circuit parameters, i.e., inductance and resistance, which are compared with experimental values     

Implementation of a Forest Biomass-Based Biofuel Industry： A Canadian Experience

The forest biomass is an abundant renewable resource from which biofuels can be derived. In the Kraft process, the cellulose is extracted from the wood to form the paper pulp while the other organic components, primarily hemicelluloses and lignin, are burnt to produce steam. It is possible to divert part of the hemicelluloses or lignin to produce fuels on site, a mode of operation referred to as the integrated forest biorefinery. Hemicelluloses can be hydrolysed into sugars which in turn are converted into ethanol or butanol, while lignin can be extracted from a residual process stream, the black liquor, by acid precipitation, de-ionized, dried and directly used as a fuel or further processed into value added chemicals. Biorefinery processes have been proposed and analysed by simulation on Aspen Plus. Intensive integration of thermal energy, water and material systems is of paramount importance to the sustainability of the global site; the increased energy load on the utility systems could cause rising dependency of the global site on fossil fuels. To avoid this consequence, a new original energy efficiency analysis and enhancement methodology has been developed and validated on actual Canadian Kraft mills before being applied to the integrated biorefinery and, has produced remarkable results far superior to the current engineering practice. This has led to the concept of the GIFBR （green integrated forest biorefinery）, i.e., an industrial site with zero fossil fuel consumption and reduced GHG （greenhouse gases） emissions vs. the Kraft process and biorefinery plant alone. The GIFBR incorporates a woody biomass gasifier producing syngas as a fuel for the integrated biorefinery and for steam production or sale. It can also include a CHP （combined heat and power） unit driven by steam made available by liberated production capacity from the installed power plant.     

Low Temperature Geothermal Applications as Enablers of Sustainable Development: Practical Case Studies from Australia and UK

This paper provides recent examples of geothermal energy application in high profile public buildings within urban settings. It outlines the application of a low temperature geothermal resource as a source of heating for the Challenge Stadium in Perth, Western Australia and the use of ambient temperature groundwater in UK for cooling at the Royal Festival Hall and the Tate Modern Gallery in Central London. Key benefits from the Challenge Stadium project completed in 2004 include reduced consumption of fossil based fuel, cost savings, water supply and water infrastructure development for a local school, enhanced sustainability profile for the sports and recreation facility. The groundwater cooling system at the Royal Festival Hall was commissioned in 2004 and fully operational in 2008 whilst the system at the Tate Modern Gallery is at an advanced stage of development. Sustainable development, specifically economic, planning, architectural and environmental factors, were the key reasons for groundwater being used as a low temperature geothermal sink for the latter projects. For cities situated on geothermal resources or productive aquifer systems, one of the greatest potential benefits from low temperature geothermal applications is the demonstration of sustainability principles, especially reduction of CO₂ emissions due to displaced usage of fossil fuels. Projects such as Challenge Geothermal, Royal Festival Hall and Tate Modern Gallery can be legitimately recognised as sustainable as they are ecologically friendly and support locally appropriate technological solutions whilst benefitting the community and economy of the city.     

Characterization of Co/ZrO2 de-NOX Thin Film Catalysts Prepared by Magnetron Sputtering

This paper reports the preparation and characterization of Co/ZrO₂ thin film catalysts. ZrO₂ thin films (S_BET～25 m² g^-1) have been prepared at low temperature by magnetron sputtering. This procedure is typically used to get compact thin films and has been modified to prepare porous catalyst layers. The obtained results prove that this can be an interesting alternative for catalyst shaping of interest for different applications. Incorporation on the zirconia support of a well-dispersed cobalt phase is achieved by electrochemical and wetness impregnation methods. Catalyst thin films deposited on stainless-steel plates have been characterized by SEM and XPS. BET measurements, carried out according to a special procedure, have been used to determine the specific surface area of the thin film catalysts. Catalytic tests for NO (1000?ppm) reduction with CH₄ or C₃H₈ (2500 ppm) in the presence or absence of O₂ (3%;) in the reactant flow show that the thin film catalyst depicts a similar catalytic behavior than a Co/ZrO₂ powder catalyst prepared by conventional methods. The results can be summarized as follows: (i) with CH₄ in the absence of O₂, a maximum of 50% reduction of NO to N₂ was obtained at 823 K; (ii) a similar conversion was obtained at 623 K when O₂ was present in the reaction flow; (iii) with C₃H₈ a 90%; conversion was obtained at 823 K without O₂, while no conversion at all was detected in the presence of O₂, although 90%; of the hydrocarbon was oxidized to CO₂ and H₂O at this temperature. The advantages and possibilities of using non-conventional methods of synthesis of thin film catalysts are highlighted.