49 research outputs found

    Qualifying tests and economic analysis of electrolyzers for grid services

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    As part of the European project QualyGridS, drafts for standardized testing protocols for electrolyzers to perform electricity grid services are defined and elaborated. These protocols are designed to be used by alkaline and proton exchange membrane (PEM) electrolyzers up to the Megawatt scale. The protocols are being submitted for standardisation. Testing results using these protocols on a state-of-the-art PEM electrolyzer system of 50 kW with 1500 cm2 area stack are presented with considerations of the influence of balance of plant (BOP) components. System behaviour of 50 kW and Megawatt PEM electrolyzers are compared to determine the influence of their scale in performance and response time. An economic analysis has been conducted in the scope of the project. Today’s situation has been analyzed in a first part: the objective was to identify the best way to combine H2 supply for a primary value stream and provision of grid services. A second part of the analysis studied the potential future evolutions that could change the current pictur

    A communal catalogue reveals Earth's multiscale microbial diversity

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    Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

    A communal catalogue reveals Earth’s multiscale microbial diversity

    Get PDF
    Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

    Neodymium Photoluminescence in Whispering Gallery Modes of Toroidal Microcavities.

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    We report on light emission from high-Q neodymium-implanted silica microtoroids. After description of the fabrication process of microtoroids, Neodymium light emission is analysed. This emission is coupled to various modes of the cavity. Using evanescent wave detection, we achieve selective detection of Whispering Gallery Modes of a microtoroid

    Barriers and facilitators to adoption and use of fuel pellets and improved cookstoves in urban Rwanda.

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    BACKGROUND:The environmental and health impacts of reliance on solid fuels and traditional cookstoves in low-income countries have motivated the promotion of household cooking energy systems that use cleaner burning fuels and cookstoves that lead to reduced exposure to harmful pollutants. Little is known about adoption and use of such systems from the users' perspective. METHODS:We explored the facilitators and barriers to adoption and use of a private sector marketed household cooking energy system that uses sustainably produced biomass pellets and the cleanest burning fan micro-gasification stove currently available. We conducted 48 in-depth qualitative interviews in Gisenyi, Rwanda with decision-makers and cooks in 16 households that adopted the improved cookstove system and 8 non-adopter households. RESULTS:Reported facilitators and barriers to adoption and non-adoption, as well as use and non-use were complex, and in some cases, contradictory. Some adopters noted that cleanliness and low smoke production were major facilitators to adoption and use, while other adopters and non-adopters said the cookstoves blackened and damaged cooking pots and produced excessive smoke. Our findings suggest that correct use of the stove mediates user experience. Cost was likewise reported as a facilitator among some adopters and a barrier among other adopters and non-adopters. Peer influence played a significant role as both a barrier and a facilitator to adoption and transcended other factors. Positive peer influence describing the cleanliness, affordability, and efficiency of the cookstove system encouraged adoption and use, while negative comments by peers regarding excessive smoke and damaged cooking pots discouraged adoption. Commentaries by some participants suggest that inadequate training and instruction may be primary causes of the discrepancies. CONCLUSION:Cost, cleanliness, communication among peer networks, and adequate training and instruction are important factors associated with the adoption and use of improved cookstoves and should be prioritized in the implementation of improved cookstove programs

    HIGHER PRICES FROM ENTRY: PRICING OF BRAND-NAME DRUGS

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    When a new firm enters a market and starts selling a spatially-differentiated product, the prices of existing products may rise due to a better match between consumers and products. Entry may have three unusual effects. First, the new price is above the monopoly price if the two firms collude and may be above the monopoly price even if the firms play Bertrand. Second, the Bertrand and collusive price may be identical. Third, prices, combined profits, and consumer surplus may all rise with entry. Consistent with our theory, the real prices of some anti-ulcer drugs rose as new products entered the market
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