The paper studies the theoretical analysis of silicon purification process using the method of extraction from solid phase in fine-dyspersated condition. Axial profile impurity concentration in silicon particles, time dynamics of average impurity concentration at various purification conditions (temperature, particle size, impurity concentration in extractant) are obtained by numerical simulation. The requirements to a particle size and temperature condition when practically important purification efficiency is reached, are determined. The design of an industrial-scale plant is shown schematically.

Microbial fuel cells (MFCs) use microorganisms to simultaneously break down organic materials and generate electricity. One of the greatest challenges in the practical application of MFCs is to sufficiently increase their power generation. Nanomodified graphite carbon anodes were prepared for use in MFCs to enhance the electron transport from the microbes to the electrode. Nanomodification to the anodes included growth of nanoparticles and multi-walled carbon nanotubes (MWCNTs). Nanoparticles of various metals, including Au, Ni, Pd, and Fe, were synthesized through thermal annealing and Fe catalyzed MWCNTs were synthesized through chemical vapor deposition. Power density was measured in MFCs for each type of nanomodified electrodes. Significant increase in power density was observed for the MFC with anodes decorated with MWCNTs (with 50-100nm diameters).

Microwave assisted syntheses of stable solvent based colloidal sols of tailored ceria nanoparticles Olivier Poncelet*, Julien Jouhannaud*, Denis Chaumont** *CEA Liten DTNM/L2T , 17 rue des Martyrs F-38054 Grenoble Cedex9, France **Institut Carnot Bourgogne (ICB), UMR5209 CNRS, Facult� des Sciences Mirande, Universit� de Bourgogne, 9 Av. Alain Savary, BP 47870, F-21078 Dijon Cedex The pressure of environmental laws in many advanced countries becoming more restricting year after year, it is asked to automobile companies to strongly control the carburant consumption of cars that they put on the market and also to eliminate toxic chemicals coming from exhaust emission gases. This is particularly true for diesel oil which is particularly efficient in terms of carburant consumption but known to release toxic chemicals in exhaust gases. Among the materials able to solve these concerns, ceria (CeO2) is a choice catalyst because it can work in two different ways first as an oxygen store by release of oxygen in the presence of reductives gases (CnHn and CO), and also by removing oxygen by interaction with oxidising species (NOx), leaving finally in exhaust gases H2O, CO2 and N2. To be efficient ceria has to be used under nanoparticle form directly added in the diesel oil. The surface developed by the nanoparticles due to their small size positively influence the catalytic properties (both oxidation and reduction step) in terms of kinetic, so the ignition delay time for nanosized particles in the combustion chamber of diesel motors fits well with the high performance diesel motor characteristics. The true challenge is to be able to prepare stable solvent based sols of crystalline ceria nanoparticles which could be used without plugging the injection nozzles. We present various synthetic ways to produce ceria nanoparticles in water followed by their surface modification allowing stable colloidal sols in organic medium to be designed. We emphasize more particularly the microwave assisted synthesis which by enhancing nucleation of the nanosized particles versus growth of nanoparticles allows very narrow sized distribution of nanoparticles to be obtained. Moreover in terms of synthetic processes, microwave assisted syntheses allow to strongly reduced the synthetic time without compromise in terms of cristallinity (TEM and XRD). Surface modifications of the nanoparticles have been monitored by FT-IR, FT-Raman, while their sizes have been monitored by DLS (differential light scattering) from water to solvents suspension proving the efficiency of ether carboxylic acids as surface modifiers. Finally we will show preliminary results on the microwave assisted syntheses of mixed oxides materials (CeZrOx) and the way to design organic based sols of nanoparticles.

LiFePO4/C composite cathode materials were synthesized by one-step solid-state reaction using FePO4 as main raw materials and solid PVA (Polyvinyl Alcohol) as a reductive agent and carbon source. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis and charge-discharge test. The results indicated that the carbon generated from the pyrogenation of PVA did not affect the olivine structure of the cathode materials but considerably improved its high-rate discharge ability and cycle performance. The initial discharge capacity of the sample was 149.7, 133.1, 120.6, 93.0 mAh/g at 0.2C, 1C, 2C, 5C respectively, and the discharge capacity could reach 90 mAh/g at 5C rates after 80 cycles. It is believed that the carbon coating could lead to small particle size and high electronic conductivity of active materials, thus leading to excellent electrochemical performance of LiFePO4/C cathode materials.

Permeable pavement systems to alleviate urban heat island phenomena are suitable for a variety of residential, commercial and industrial applications, yet are confined to light duty and infrequent usage. And Most of study for the permeable pavement is limited to asphalt pavement. Also, immense quantities of coal combustion by-products are produced every year, but only a small fraction of them are currently utilized, particularly bottom ash which is used in this study. In this study, we aimed at the development of new permeable and water absorbing pavement blocks. Optimum conditions for compressive strength and water absorption, volume of water retention and porosity characteristics were investigated for production of the pavement blocks from bottom ash. In addition, removal efficiencies of pollutants in road runoff by the pavement blocks were compared under various conditions. Experimental results showed that the compressive strengths and water absorption after 7 and 28days for blocks were 12˜15MPa and 18%, respectively. Also, turbidity and heavy metals in rainwater were successfully removed. So, further study on the durability test such as the effect of surface fouling by dust is possibly needed prior to use the new bricks as construction materials.

This work investigates the critical stress and morphological evolutions which occur during the high-temperature oxidation of metallic alloys for SOFC interconnects. Two mechanisms of stress generation are considered related to (1) the local volume change associated with the direct oxidation of the metal and to (2) a secondary oxidation process within grain boundaries. A specific formulation is developed to include the influence of the stress state at the metal-oxide interface on the local oxidation kinetics. The oxidation of a chromia-forming SOFC interconnect metallic alloy is simulated and stress and morphological evolutions are investigated.

It is clear that in the next ten years major changes will be required in our liquids for transportation energy scenario. These changes are driven by two major factors. The first is the desire to achieve 'energy independence' and the second is the desire to achieve an 'environmentally friendly' fuel supply. These two forces will dominate energy research and development in the near future. This presupposes that the lack of viable hydrogen storage materials and the long-range electric vehicle materials will continue to be limiting the hydrogen and electric vehicle technology. The DOE recently reported that the available amounts of heavy hydrocarbons (tars, coal and shale oils) in North America (United States, Canada and Mexico) are sufficient for 500 years at current rates of usage. However, these sources must be converted to liquid transportation fuels in an environmentally favorable manner. Also, promising sources of sustainable liquid transportation fuels maybe found in growing algae and converting the contained lipids to biodiesel. In this presentation we discuss recent development in both areas that promise a smooth transition from conventional to the use of sustainable transportation fuel sources.

We have recently reported a solid-state, mass-quantity transformation from V2O5 powders to nanorods via a two-step approach [1]. In this paper we present detailed investigation of the growth process using x-ray diffraction, scanning/transmission electron microscopy and electron spin resonance. The growth of nanorods at intermediate stages has been examined. Oxidation, surface energy minimization and surface diffusion play important roles in the growth mechanism.

The paper addresses the �green innovation� in the non-fossil fuel energy industry. The objective of the study is to identify the changes in trends of non-fossil fuel energy industry demand, growth and opportunities. The study uses the databases such as patents, news events, income/financial statements to assess the company status and the track record of the industry. The research adopts the methodology of Innovation Radar (Sawhney, MIT Sloan Management Research, 2001) to assess the positioning of the dominant company and design in photovoltaic, geothermal and wind renewable energy industry. The study also summarizes the sustainable competitive advantages of some of the successful companies in the energy sector. This study correlates the gains in innovation tripartite (product, process, business) to the corporate competitive advantage. The companies selected in this study are based on the innovations brought to improve the product, process and business aspects and are evaluated in terms of market adaptability.

Exergy is the useful portion of energy that allows us to do work and perform energy services. While energy is conserved, exergy is not; some exergy is destroyed whenever energy undergoes a conversion. We gather exergy from distinct, energy-carrying resources that are found in the natural world. These resources are converted into energy carriers that are convenient to use in our factories, vehicles, and buildings for heating, lighting and mechanical services. While there is no shortage of exergy resources, there are considerable environmental, economic, and other constraints associated with the manner and magnitude of their use. This article describes an approach to examining and presenting data on energy use at a global scale. It provides insights into the efficiencies and carbon emissions of many energy pathways, and can provide a basis for an examination of future energy options. In this study, we trace the flow of exergy and carbon through the natural and human systems, revealing the major destructions of exergy, the exergy efficiency of engineered energy processes, and the processes with the highest associated atmospheric carbon emissions. These data have been collected in a relational database available online at http://gcep.stanford.edu/research/exergy/data.html and are presented here in a set of exergy and carbon flow charts.

The effect of the electropulsing on recrystallized microstructure and on texture evolution of a cold rolling (CR) AZ31 strip was studied with the help of light microscopy and X-ray diffraction technique. It was exciting that the completed recrystallization state of sample subjected to the electropulsing treatment (EPT) could be obtained rapidly in ˜7s with the basal texture weakened. The favoring mechanism of static recrystallization (SRX) of MPT could be attributed to the coupled action of the thermal and athermal effects, thereinto, the latter one activated dislocation climb effectively.