Systemic analysis of production scenarios for bioethanol produced from ligno-cellulosic biomass [abstract]

Defining alternatives for non-renewable energy sources constitutes a priority to the development of our societies. One of these alternatives is biofuels production starting from energy crops, agricultural wastes, forest products or wastes. In this context, a "second generation" biofuels production, aiming at utilizing the whole plant, including ligno-cellulosic (hemicelluloses, cellulose, lignin) fractions (Ogier et al., 1999) that are not used for human food, would allow the reduction of the drawbacks of bioethanol production (Schoeling, 2007). However, numerous technical, economical, ethical and environmental questions are still pending. One of the aims of the BioEtha2 project, directed by the Walloon Agricultural Research Centre, is to define the position of bioethanol produced from ligno-cellulosic biomass among the different renewable energy alternatives that could be developed in Wallonia towards 2020. With this aim, and in order to answer the numerous questions in this field, the project aims at using tools and methods coming from the concept of "forecasting scenarios" (Sebillotte, 2002; Slegten et al., 2007; For-learn, 2008). This concept, based on a contemporary reality, aims to explore different possible scenarios for the future development of alternative sources of energy production. The principle is to evaluate, explore, possible futures of the studied problematic, through the establishment of possible evolution trajectories. We contribute to this prospective through a systemic approach (Vanloqueren, 2007) that allows lightening the existing interactions within the system "ligno-cellulosic biomass chain" without isolating it from its environment. We explain and sketch the two contexts needed to identify primary stakes. The global context includes inter-dependant and auto-regulating fields such as society, politics, technology and economy. These four fields influence each part of the "chain" with specific tools. However, the interest and possible action fields lay within the intermediary context representing the "resources" such as agriculture, forestry, "driving" elements such as mobility, mediation elements such as territories and environment and concurrent elements such as non-cellulosic biomass, the energy mix and the non-energy valorization

Involvement of pholcodine in the cause of death in 127 forensic cases in France

Date du colloque&nbsp;: 2008</p

1,3-Diacylaminopropan-2-ols and corresponding 2-acyl derivatives as drug carriers: unexpected pharmacological properties.

The design of lipid vectors (pseudotriglycerides, PTGs), achieved by the amide isosteric substitution of the ester moieties of 1,3-diacylglycerols, is based on the structural similarity with natural triglycerides facilitating the passage of pharmacological agents across biological membranes. 2-S-Acetylthiorphan (hemiacetorphan) pseudotriglycerides, Z-glycine pseudotriglycerides and 1,3-diacylaminopropan-2-ols vector molecules differing by the nature of the acid side-chain are examined in acute toxicity, radioligand binding and guinea-pig ileum experiments. These evaluations have led us to distinguish two types of compounds. Linear derivatives, palmitoyl and decanoyl, are devoid of toxicity and intrinsic activity. Cyclic derivatives, which contain in the acyl chain a phenyl, cyclohexyl, cyclopentyl or adamantoyl ring, present additional properties. Cyclic derivatives of hemiacetorphan are lethal after intravenous administration. The mortality is governed by the 2-hemiacetorphan moiety in the cyclic vector molecules. Hemiacetorphan alone is also lethal. Cyclic vector molecules and related compounds inhibit the contractile response of the guinea-pig ileum induced by electrical stimulation, histamine or acetylcholine (noncompetitive antagonism) whereas linear entities and parent compounds are not active. In particular, the 2-hemiacetorphan 1,3-diadamantoylamide PTG presents pD'2 values 7.87 +/- 0.29 (vs histamine) and 7.97 +/- 0.12 (vs acetylcholine)

Heavy-ion irradiation of pyrochlore oxides: Comparison between low and high energy regimes

International audienceA summary of the results on the radiation stability of pyrochlores (Gd2Zr2O7, Nd2Zr2O7, Gd2Ti2O7) in the electronic stopping regime is given. X-ray diffraction and Raman spectroscopy show a transformation from the ordered pyrochlores (Fd3m) to the anion deficient fluorite (Fm3m) structure in Gd2Zr2O7 or amorphization in Nd2Zr2O7. The track diameter, crystallite size and progression in structural modifications have been monitored. It is found that radiation stability of these pyrochlores depends on the energy to form cation antisites and delocalized anion vacancies. This in turn is correlated to the radius ratio of A-B cations. This criterion for evaluating radiation resistance of pyrochlores has important implications in the field of inert matrix fuels. (C) 2008 Elsevier B.V. All rights reserved

Imputabilité en toxicologie postmortem : exemple d'un travail sur la pholcodine

Date du colloque&nbsp;: 10/2008</p