3,951 research outputs found

    Investigation of the reactivity of organic materials in liquid oxygen

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    Measurements of impact-ignition sensitivity and studies of the relative reactivity of t-butoxy and t-butyl peroxy radicals toward a variety of organic compounds reveal improved methods of selection of materials for safe use in a liquid oxygen environment

    Integrated Life Cycle and Techno-Economic Assessment of the Conversion of High Productivity, Low Lipid Algae to Renewable Fuels

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    The production of alternative transportation fuels is imperative to meet future energy demands without contributing to global climate change. Advances in alternative processing techniques that have emerged due to interest in microalgae as a feedstock have led to a variety of potential processing pathways for the production of bio-based fuels. A major hurdle in the algal production process is maintaining a fast and stable algae culture. Monocultures, developed for their high lipid content, suffer from low productivity, are susceptible to crashes and require a constant supply of carbon dioxide to maintain productivity. In an effort to circumvent these obstacles, algal turf scrubber systems (ATS) are now being targeted not only for water purification, but as a means of producing algae feedstocks for fuel conversion. The resulting algae are capable of being harvested at a much higher density, requiring less energy for dewatering purposes. ATS systems do present other drawbacks that downstream technologies need to account for to make this system a viable means for fuel conversion. While polyculture algae species display great growth characteristics, they contain high percentages of nitrogen containing proteins and low lipid content. If not removed this nitrogen pollutes any resulting biocrude making it unacceptable for diesel fuel blends. This study investigates a processing method which reduces the nitrogen content of the resulting fuel by fermenting both carbohydrates and proteins into intermediate compounds. By tuning the E. coli fermentation stain it is hoped that the process will yield higher value co-products than those investigated in this study. The research contained herein incorporates laboratory experimentation with engineering systems modeling to assess the economic feasibility and environmental impacts of generating biofuels from ATS cultivated algae. Results show a minimum fuel selling price of $5.93 per gasoline gallon equivalent and greenhouse gas emissions of -0.0185 kg CO2eq per MJ fuel. Discussion points include process optimization in terms of minimum fuel selling price and global warming potential

    Fundamentfokkerij Fries Hollands vee

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    Dit onderzoeksverslag is tot stand gekomen vanuit het netwerk Fundamentfokekrij Fries Hollands Vee, een praktijknetwerk veehouderij dat wordt gefinancierd door Dienst Regelingen (LNV) met geld voor plattelandsontwikkeling in Europa. Vanuit dit netwerk is fokkerij data verzameld van de fundamentfokbedrijven van de FH vereniging. Met deze data is de fokkerijpraktijk van deze bedrijven in beeld gebracht voor de vereniging zelf en ook om deze fokkerij te kunnen gebruiken als voorbeeld voor andere veehouders die ook met eigen stieren fokken of dat willen gaan doen

    Investigation of Reactivity of Launch Vehicle Materials with Liquid Oxygen

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    Impact sensitivity and ignition mechanism of organic compounds in liquid oxygen correlated with chemical and physical propertie

    A yellowwood by any other name: molecular systematics and the taxonomy of Podocarpus and the Podocarpaceae in southern Africa

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    We briefly review the taxonomic history of the Podocarpaceae, with an emphasis on the recognition of numerous segregate genera out of Podocarpus sensu lato. Despite some controversy over the recognition of these genera, molecular data (DNA sequences) provide evidence that supports this taxonomy. The implications for African Podocarpaceae are discussed. In particular, molecular data support the recognition of Afrocarpus as distinct from Podocarpus. Additional taxonomic problems concerning the possible segregation of Podocarpus milanjianus from P. latifolius are addressed using DNA sequence data from the nuclear internal transcribed spacer 2 (ITS2) region. Results of this are inconclusive, and suggest that alternative DNA-based evidence, such as from AFLPs or microsatellites, may be more informative in resolving such species complexes in African Podocarpus

    A New Species of Pedicularis (Scrophulariaceae) from the Yaoshan Mountain, Yunnan, China

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    Elucidating novel dysfunctional pathways in Alzheimer's disease by integrating loci identified in genetic and epigenetic studies

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    AbstractAlzheimer's disease is a complex neurodegenerative disorder. A large number of genome-wide association studies have been performed, which have been supplemented more recently by the first epigenome-wide association studies, leading to the identification of a number of novel loci altered in disease. Twin studies have shown monozygotic twin discordance for Alzheimer's disease (Gatz et al., 2006), leading to the conclusion that a combination of genetic and epigenetic mechanisms is likely to be involved in disease etiology (Lunnon & Mill, 2013). This review focuses on identifying overlapping pathways between published genome-wide association studies and epigenome-wide association studies, highlighting dysfunctional synaptic, lipid metabolism, plasma membrane/cytoskeleton, mitochondrial, and immune cell activation pathways. Identifying common pathways altered in genetic and epigenetic studies will aid our understanding of disease mechanisms and identify potential novel targets for pharmacological intervention
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