4,362 research outputs found

    Shale oil : potential economies of large-scale production, preliminary phase

    Get PDF
    Producing shale oil on a large scale is one of the possible alternatives for reducing dependence of the United States on imported petroleum. Industry is not producing shale oil on a commercial scale now because costs are too high even though industry dissatisfaction is most frequently expressed about "non-economic" barriers: innumerable permits, changing environmental regulations, lease limitations, water rights conflicts, legal challenges, and so on. The overall purpose of this study is to estimate whether improved technology might significantly reduce unit costs for production of shale oil in a planned large-scale industry as contrasted to the case usually contemplated: a small industry evolving slowly on a project-by-project basis. In this preliminary phase of the study, we collected published data on the costs of present shale oil technology and adjusted them to common conditions; these data were assembled to help identify the best targets for cost reduction through improved large-scale technology They show that the total cost of producing upgraded shale oil (i.e. shale oil accpetable as a feed to a petroleum refinery) by surface retorting ranges from about 18to18 to 28/barrel in late '78 dollars with a 20% chance that the costs would be lower than and 20% higher than that range. The probability distribution reflects our assumptions about ranges of shale richness, process performance, rate of return, and other factors that seem likely in a total industry portfolio of projects. About 40% of the total median cost is attributable to retorting, 20% to upgrading, and the remaining 40% to resource acquisition, mining, crushing, and spent shale disposal and revegetation. Capital charges account for about 70% of the median total cost and operating costs for the other 30%. There is a reasonable chance that modified in-situ processes (like Occidental's) may be able to produce shale oil more cheaply than surface retorting, but no reliable cost data have been published; in 1978, DOE estimated a saving of roughly $5/B for in-situ. Because the total costs of shale oil are spread over many steps in the production process, improvements in most or all of those steps are required if we seek a significant reduction in total cost. A June 1979 workshop of industry experts was held to help us identify possible cost-reduction technologies. Examples of the improved large-scale technologies proposed (for further evaluation) to the workshop were: - Instead of hydrotreating raw shale oil to make syncrude capable of being refined conventionally, rebalance all of a refinery's processes (or develop new catalysts/processes less sensitive to feed nitrogen) to accommodate shale oil feed -- a change analogous to a shift from sweet crude to sour crude. - Instead of refining at or near the retort site, use heated pipelines to move raw shale oil to existing major refining areas. - Instead of operating individual mines, open-pit mine all or much of the Piceance Creek Basin. - Instead of building individual retorts, develop new methods for mass production of hundreds of retorts

    Parents, children and the porous boundaries of the sexual family in law and popular culture

    No full text
    This article focuses on a perceived ideological overlap between popular cultural and judicial treatments of sex and conjugality that contributes to a discursive construction of parenthood and parenting. The author perceives that in both legal and popular cultural texts, there is a sense in which notions of ‘natural’ childhood are discursively constituted as being put at risk by those who reproduce outside of dominant sexual norms, and that signs of normative sexuality (typically in the form of heterosexual coupling) may be treated as a sign of safety. These ideas are rooted in ancient associations between fertility, sexuality and femininity that can also be traced in the historical development of the English language. With the help of commentators such as Martha Fineman, the article situates parents and children within a discourse of family which prioritises conjugality, with consequences for the ways in which the internal and external boundaries of families are delineated

    Joint and individual analysis of breast cancer histologic images and genomic covariates

    Get PDF
    A key challenge in modern data analysis is understanding connections between complex and differing modalities of data. For example, two of the main approaches to the study of breast cancer are histopathology (analyzing visual characteristics of tumors) and genetics. While histopathology is the gold standard for diagnostics and there have been many recent breakthroughs in genetics, there is little overlap between these two fields. We aim to bridge this gap by developing methods based on Angle-based Joint and Individual Variation Explained (AJIVE) to directly explore similarities and differences between these two modalities. Our approach exploits Convolutional Neural Networks (CNNs) as a powerful, automatic method for image feature extraction to address some of the challenges presented by statistical analysis of histopathology image data. CNNs raise issues of interpretability that we address by developing novel methods to explore visual modes of variation captured by statistical algorithms (e.g. PCA or AJIVE) applied to CNN features. Our results provide many interpretable connections and contrasts between histopathology and genetics

    Mercury Bioaccumulation in Wood Frogs Developing in Seasonal Pools

    Get PDF
    Seasonal woodland pools contribute significant biomass to terrestrial ecosystems through production of pool-breeding amphibians. The movement of amphibian metamorphs potentially transports toxins bioaccumulated during larval development in the natal pool into the surrounding terrestrial environment. We documented total mercury (THg) in seasonal woodland pool water, sediment, litter, and Lithobates sylvaticus LeConte (Wood Frog) in Acadia National Park, ME. THg concentrations in pool water varied over the study season, increasing during April-June and remaining high in 2 of 4 pools upon October refill. Water in pools surrounded by softwoods had lower pH, greater dissolved organic carbon, and greater THg concentrations than pools surrounded by hardwoods, with seasonal patterns in sediment THg but not litter THg. THg increased rapidly from near or below detection in 1-2 week old embryos (\u3c 0.2 ng; 0-0.49 ppb wet weight) to 17.1-54.2 ppb in tadpoles within 6 weeks; 7.2-42.0% of THg was methyl Hg in tadpoles near metamorphosis. Metamorphs emigrating from seasonal pools may transfer mercury into terrestrial food webs

    Scholar-activists in an expanding European food sovereignty movement

    Get PDF
    This article analyzes the roles, relations, and positions of scholar-activists in the European food sovereignty movement. In doing so, we document, make visible and question the political dimensions of researchers' participation in the movement. We argue that scholar-activists are part of the movement, but are distinct from the affected constituencies, put in place to ensure adequate representation of key movement actors. This is because scholar-activists lack a collective identity, have no processes to formulate collective demands, and no mechanisms for inter-researcher and researchers-movement communication. We reflect on whether and how scholar-activists could organize, and discuss possible pathways for a more cohesive and stronger researcher engagement in the movement.</p

    The Jurisdiction of the D.C. Circuit

    Get PDF

    The Jurisdiction of the D.C. Circuit

    Get PDF
    The U.S. Court of Appeals for the D.C. Circuit is unique among federal courts, well known for an unusual caseload that is disproportionally weighted toward administrative law. What explains that unusual caseload? This Article explores that question. We identify several factors that “push” some types of cases away from the Circuit and several factors that “pull” other cases to it. We give particular focus to the jurisdictional provisions of federal statutes, which reveal congressional intent about the types of actions over which the D.C. Circuit should have special jurisdiction. Through a comprehensive examination of the U.S. Code, we identify several trends. First, the Congress is more likely to give the D.C. Circuit exclusive jurisdiction over the review of administrative rulemaking than over the review of agency decisions imposing a penalty. Second, the Congress is more likely to give the D.C. Circuit exclusive jurisdiction over the review of independent agency actions than over the review of executive agency actions. Finally, the Congress tends to grant the D.C. Circuit exclusive jurisdiction over matters that are likely to have a national effect. In sum, we explore what makes this court unique, from its history to its modern docket and jurisdiction

    Long-lived quantum coherence in photosynthetic complexes at physiological temperature

    Full text link
    Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center which stores energy from the photon in chemical bonds. This process occurs with near-perfect quantum efficiency. Recent experiments at cryogenic temperatures have revealed that coherent energy transfer - a wavelike transfer mechanism - occurs in many photosynthetic pigment-protein complexes (1-4). Using the Fenna-Matthews-Olson antenna complex (FMO) as a model system, theoretical studies incorporating both incoherent and coherent transfer as well as thermal dephasing predict that environmentally assisted quantum transfer efficiency peaks near physiological temperature; these studies further show that this process is equivalent to a quantum random walk algorithm (5-8). This theory requires long-lived quantum coherence at room temperature, which never has been observed in FMO. Here we present the first evidence that quantum coherence survives in FMO at physiological temperature for at least 300 fs, long enough to perform a rudimentary quantum computational operation. This data proves that the wave-like energy transfer process discovered at 77 K is directly relevant to biological function. Microscopically, we attribute this long coherence lifetime to correlated motions within the protein matrix encapsulating the chromophores, and we find that the degree of protection afforded by the protein appears constant between 77 K and 277 K. The protein shapes the energy landscape and mediates an efficient energy transfer despite thermal fluctuations. The persistence of quantum coherence in a dynamic, disordered system under these conditions suggests a new biomimetic strategy for designing dedicated quantum computational devices that can operate at high temperature.Comment: PDF files, 15 pages, 3 figures (included in the PDF file

    An integrated cell-free metabolic platform for protein production and synthetic biology

    Get PDF
    Cell-free systems offer a unique platform for expanding the capabilities of natural biological systems for useful purposes, i.e. synthetic biology. They reduce complexity, remove structural barriers, and do not require the maintenance of cell viability. Cell-free systems, however, have been limited by their inability to co-activate multiple biochemical networks in a single integrated platform. Here, we report the assessment of biochemical reactions in an Escherichia coli cell-free platform designed to activate natural metabolism, the Cytomim system. We reveal that central catabolism, oxidative phosphorylation, and protein synthesis can be co-activated in a single reaction system. Never before have these complex systems been shown to be simultaneously activated without living cells. The Cytomim system therefore promises to provide the metabolic foundation for diverse ab initio cell-free synthetic biology projects. In addition, we describe an improved Cytomim system with enhanced protein synthesis yields (up to 1200 mg/l in 2 h) and lower costs to facilitate production of protein therapeutics and biochemicals that are difficult to make in vivo because of their toxicity, complexity, or unusual cofactor requirements
    corecore