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Nuclear membrane attached DNA enriched in repetitive sequences 总被引:1,自引:0,他引:1
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Pieternel A.M. Claassen Truus de Vrije Emmanuel Koukios Ed van Niel Inci Eroglu Michael Modigell Anton Friedl Walter Wukovits Werner Ahrer 《Journal of Cleaner Production》2010
The objectives and methodology of the EU-funded research project HYVOLUTION devoted to hydrogen production from biomass are reviewed.The main scientific objective of this project is the development of a novel two-stage bioprocess employing thermophilic and phototrophic bacteria, for the cost-effective production of pure hydrogen from multiple biomass feedstocks in small-scale, cost-effective industries. Results are summarised of the work on pretreatment technologies for optimal biodegradation of energy crops and bio-residues, conditions for maximum efficiency in conversion of fermentable biomass to hydrogen and CO2, concepts of dedicated installations for optimal gas cleaning and gas quality protocols, as well as innovative system integration aimed at minimizing energy demand and maximizing product output.The main technological objective is the construction of prototype modules of the plant which, when assembled, form the basis of a blueprint for the whole chain for converting biomass to pure hydrogen. A brief outline is presented of the progress made towards developing reactors for thermophilic hydrogen production, reactors for photoheterotrophic hydrogen production and equipment for optimal gas cleaning procedures. 相似文献
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The environmental impact of hydrogen production in a 2-step fermentation process from potato steam peels was identified. Based on the ISO 14040, ISO 14044, ecoinvent data base and SimaPro 7.1 software, a life cycle inventory analysis was performed. Reflecting the current state of process development, the LCA shows an impact of 4.3 points (pts) which is at least 5.7 times higher than the selected reference technologies regarded as state-of-the-art. Over half (53.5%) of the environmental impact is generated by the use of phosphate in the fermentation processes. A sensitivity analysis shows a potential impact reduction of 65.8% due to recirculation of sewage or reduction of buffer concentration. The analysis also demonstrates that the production of the process ingredients cause 98.3% of the environmental impact. The impact of the process itself is 0.07 pts which is up to 10 times lower than the reference technologies. 相似文献
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Understanding the factors responsible for generating size variation in cohorts of organisms is important for predicting their population and evolutionary dynamics. We group these factors into two broad classes: those due to scaling relationships between growth and size (size-dependent factors), and those due to individual trait differences other than size (size-independent factors; e.g., morphology, behavior, etc.). We develop a framework predicting that the nonlethal presence of predators can have a strong effect on size variation, the magnitude and sign of which depend on the relative influence of both factors. We present experimental results showing that size-independent factors can strongly contribute to size variation in anuran larvae, and that the presence of a larval dragonfly predator reduced expression of these size-independent factors. Further, a review of a number of experiments shows that the effect of this predator on relative size variation of a cohort ranged from negative at low growth rates to positive at high growth rates. At high growth rates, effects of size-dependent factors predominate, and predator presence causes an increase in the scaling of growth rate with size (larger individuals respond less strongly to predator presence than small individuals). Thus predator presence led to an increase in size variation. In contrast, at low growth rates, size-independent factors were relatively more important, and predator presence reduced expression of these size-independent factors. Consequently, predator presence led to a decrease in size variation. Our results therefore indicate a further mechanism whereby nonlethal predator effects can be manifest on prey species performance. These results have strong implications for both ecological and evolutionary processes. Theoretical studies indicate that changes in cohort size variation can have profound effects on population dynamics and stability, and therefore the mere presence of a predator could have important ecological consequences. Further, changes in cohort size variation can have important evolutionary implications through changes in trait heritability. 相似文献