SUITABILITY OF WOOD CHIPS FROM FORESTRY AND DIFFERENT BIOMASS FEEDSTOCKS FOR USE IN A SEMI-INDUSTRIAL PLANT OF BTL PRODUCTION BY GASIFICATION

A semi-industrial plant of BtL production by biomass gasification is planned to be operating in 2011 in the Northern-East of France by a French Energy Research Centre, called Commissariat à l’Energie Atomique (CEA), and several partners. This demonstration plant will be a 50 MW plant, based on an entrained flow reactor, followed by different stages of syngas cleaning and a final stage of Fischer-Tropsch synthesis. One study has been launched on the biomass regional resources that may be used as feedstock in the plant. The first task of this study deals with the availability of the resources and their feasibility and cost of supply. This paper is focused on the second task, whose aim is to check the suitability of the potential resources with the process, in order to define which one should be chosen. A sampling based on several tens samples from the region was first used, both from wood chips from forestry, wood chips from Short Rotation Coppice (SRC) and agricultural raw materials including straw and energy crops. Measurements were done on the main influential properties of biomass, either physical (granulometry, density, moisture), thermal (LHV) or physico-chemical (proximate analysis, elemental composition, particularly in minor elements, ash composition and fusibility). Results show that there is not much variability in the biomass properties inside the different families (wood chips, agricultural raw materials). The values of most properties fall in the range of the required specifications. However, some properties may be questionable: (i) wood chips granulometry, with too many fine particles (ii) density, which is too low in agricultural products (0.05), (iii) sulphur, fluorine and chlorine contents, which are too high, especially chlorine in agricultural residues (1000-8000 ppm) (iv) other impurities amounts, such as Cr, Cu, Zn, Ni, that are above specifications in some samples (v) ash content, which is slightly too high in SRC (3 wmf%) and too high in most agricultural raw materials (5 wmf%) (vi) ash melting point - whose measurement still needs to be confirmed - but which is apparently too low in most agricultural samples and in some SRC. Based on these statements, wood chips from forestry appear as the most suitable resource for the process. SRC also seem quite suitable for the process and may be seen as a short-term alternative. Agricultural raw materials are more problematical and may be seen as a short to mid-term option. Therefore, wood chips will be the first resource to be used in the demonstration plant and a complimentary sampling has been recently performed on this kind of feedstock, leading to the adjunction of 60 new samples. These measurements should enable to define more precisely the range of variation of the problematic properties

A combination of methotrexate and zoledronic acid prevents bone erosions and systemic bone mass loss in collagen induced arthritis

Introduction Osteoclasts play a key role in the pathogenesis of bone erosion and systemic bone mass loss during rheumatoid arthritis (RA). In this study, we aimed to determine the effect of methotrexate (MTX) and zoledronic acid (ZA), used alone or in combination, on osteoclast-mediated bone erosions and systemic bone mass loss in a rat model of collagen induced arthritis (CIA). We hypothesized that MTX and ZA could have an additive effect to prevent both bone erosion and systemic bone loss. Methods Arthritis was induced in 64 female Sprague-Dawley rats. After the clinical onset of CIA, rats were assigned to treatment with MTX (1 mg/kg/week), ZA (100 μg/kg twice weekly), both treatments at the same regimens, or vehicle. Arthritis score and paw thickness were recorded twice weekly. The rats were sacrificed on D28 and hind paws were removed for radiographic, histological and immunohistochemical analysis. The effects of treatments on osteoclastogenesis were determined by Tartrate resistant acid phosphatase (TRAP) staining. Micro-CT of the tibia was carried out for histomorphometric analysis. Bone mass density was evaluated by densitometry. Results MTX significantly decreased the severity of CIA, whereas ZA slightly exacerbated it. When these two drugs were used in combination, MTX prevented the pro-inflammatory effect of ZA. The combination of ZA with MTX was more effective than MTX alone for reducing structural joint damage with a dramatic decrease of osteoclasts' number in the eroded joints. However, MTX alone also significantly reduced the number of osteoclasts and the number of CD68+ mononuclear cells. ZA alone, or ZA with MTX, significantly increased the systemic bone mass density measured by densitometry and bone volume on histomorphometric analysis. Conclusions A combination of MTX and ZA prevented both bone erosion and systemic bone loss in a rat model of arthritis. Both treatments independently decreased the number of osteoclasts in the eroded joint. However, while MTX probably acts mainly through a decrease of inflammation, ZA has a direct effect on osteoclasts, allowing a dramatic down-regulation of these cells in inflamed joints. These two different mechanisms of action provide support for the use of a combination of these two drugs to improve the prevention of structural joint damage in RA

Screening for Toxic Amyloid in Yeast Exemplifies the Role of Alternative Pathway Responsible for Cytotoxicity

The relationship between amyloid and toxic species is a central problem since the discovery of amyloid structures in different diseases. Despite intensive efforts in the field, the deleterious species remains unknown at the molecular level. This may reflect the lack of any structure-toxicity study based on a genetic approach. Here we show that a structure-toxicity study without any biochemical prerequisite can be successfully achieved in yeast. A PCR mutagenesis of the amyloid domain of HET-s leads to the identification of a mutant that might impair cellular viability. Cellular and biochemical analyses demonstrate that this toxic mutant forms GFP-amyloid aggregates that differ from the wild-type aggregates in their shape, size and molecular organization. The chaperone Hsp104 that helps to disassemble protein aggregates is strictly required for the cellular toxicity. Our structure-toxicity study suggests that the smallest aggregates are the most toxic, and opens a new way to analyze the relationship between structure and toxicity of amyloid species

Le point sur les technologies de l'embryon : outil d'avenir pour l'assainissement des troupeaux

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In vivo development after surgical transfer of porcine embryos vitrified with the Open Pulled Straw method

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Déterminants et enjeux sociétaux d'une réforme scolaire (le cas de la rénovation de l'enseignement agricole, 1984-2000)

Bureau de recherches géologiques et minières - Orléans (brgm) / SudocSudocFranceF

Collection A.M. 850 monnaies d'or du monde entier de Darius à nos jours : Vente des 9 & 10 juin 2014 / Françoise Berthelot-Vinchon

[Vente. Art. 2009-06-09 - 06-10. Paris]Avec mode text

Cryopréservation et transfert des embryons porcins produits in vivo : état des lieux

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Surgical transfer of porcine vitrified blastocysts to different uterine sites

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