3,488 research outputs found

    Ammonia removal in anaerobic digestion by biogas stripping: an evaluation of process alternatives using a first order rate model based on experimental findings

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    The feasibility of biogas stripping to remove ammonia in the anaerobic digestion of source segregated food waste was investigated. It was found in batch experiments that ammonia could be removed from digestate and that the removal followed 1st order kinetics with respect to total ammonia nitrogen concentration. Increasing temperature, biogas flow rate and initial pH all increased removal rates. Using kinetic data gathered in these experiments allowed the integration of ammonia stripping with an anaerobic digestion plant to be modelled for different configurations. Four scenarios were identified: post digestion, in situ, side-stream and pre-digestion ammonia removal relating to where in the process the ammonia stripping was performed. The modelling showed that in situ ammonia removal may be best able to reduce in-digester ammonia concentrations over a wide range of organic loading rates whereas pre-digestion showed most promise in terms of application due to the flexibility to control each part of the process separately. Further experimental work is required into these scenarios to confirm their viability

    Group B Streptococcus Meningitis Following Elective Termination of Pregnancy: Two Case Reports

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    Background: Although maternal group B streptococcus (GBS) infections are common, serious infections are rare with prompt diagnosis and treatment. We present 2 cases of GBS meningitis occurring 3 and 10 days after elective abortion. In the first patient, GBS meningitis was definitely related to the elective termination. In the second patient, however, no evidence for a causal relationship could be established and can only be presumed

    A human factors approach to analysing military command and control

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    This paper applies the Event Analysis for Systemic Teamwork (EAST) method to an example of military command and control. EAST offers a way to describe system level 'emergent properties' that arise from the complex interactions of system components (human and technical). These are described using an integrated methods approach and modelled using Task, Social and Knowledge networks. The current article is divided into three parts: a brief description of the military command and control context, a brief description of the EAST method, and a more in depth presentation of the analysis outcomes. Numerous findings emerge from the application of the method. These findings are compared with similar analyses undertaken in civilian domains, where Network Enabled Capability (NEC) is already in place. The emergent properties of the military scenario relate to the degree of system reconfigurability, systems level Situational Awareness (SA), team-working and the role of mediating technology. It is argued that the EAST method can be used to offer several interesting perspectives on designing and specifying NEC capability in military context

    TPL-2 restricts Ccl24-dependent immunity to Heligmosomoides polygyrus

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    Funding: This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001220), the UK Medical Research Council (FC001220), and the Wellcome Trust (FC001200). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We are indebted to The Francis Crick Institute Flow Cytometry facility, and in particular Bhavik Patel, Graham Preece, Wayne Turnbull and Phil Hobson. We would also like to thank The Francis Crick Institute Procedural Service Section for production of GA lines and Biological Services, especially Trisha Norton, Keith Williams and Adebambo Adekoya for animal husbandry and technical support; to Riccardo Guidi for constructive discussions and technical assistance. We would like to thank Gitta Stockinger and AhR Immunity Laboratory for providing technical support and reagents throughout this study. We also thank Richard Rance and the Wellcome Trust Sanger Institute’s 454 pyrosequencing team for generating 16S rRNA gene data.Peer reviewedPublisher PD

    Structural discordance between neogene detachments and frontal sevier thrusts, central Mormon Mountains, southern Nevada

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    This is the published version. Copyright 1985 American Geophysical Union. All Rights Reserved.Detailed geologic mapping in the Mormon Mountains of southern Nevada provides significant insight into processes of extensional tectonics developed within older compressional orogens. A newly discovered, WSW-directed low-angle normal fault, the Mormon Peak detachment, juxtaposes the highest levels of the frontal most part of the east-vergent, Mesozoic Sevier thrust belt with autochthonous crystalline basement. Palinspastic analysis suggests that the detachment initially dipped 20–25° to the west and cut discordantly across thrust faults. Nearly complete lateral removal of the hanging wall from the area has exposed a 5 km thick longitudinal cross-section through the thrust belt in the footwall, while highly attenuated remnants of the hanging wall (nowhere more than a few hundred meters thick) structurally veneer the range. The present arched configuration of the detachment resulted in part from progressive “domino-style” rotation of a few degrees while it was active, but is largely due to rotation on younger, structurally lower, basement-penetrating normal faults that initiated at high-angle. The geometry and kinematics of normal faulting in the Mormon Mountains suggest that pre-existing thrust planes are not required for the initiation of low-angle normal faults, and even where closely overlapped by extensional tectonism, need not function as a primary control of detachment geometry. Caution must thus be exercised in interpreting low-angle normal faults of uncertain tectonic heritage such as those seen in the COCORP west-central Utah and BIRP's MOIST deep-reflection profiles. Although thrust fault reactivation has reasonably been shown to be the origin of a very few low-angle normal faults, our results indicate that it may not be as fundamental a component of orogenic architecture as it is now widely perceived to be. We conclude that while in many instances thrust fault reactivation may be both a plausible and attractive hypothesis, it may never be assumed

    Numerical Modeling of Ablation Heat Transfer

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    A unique numerical method has been developed for solving one-dimensional ablation heat transfer problems. This paper provides a comprehensive description of the method, along with detailed derivations of the governing equations. This methodology supports solutions for traditional ablation modeling including such effects as heat transfer, material decomposition, pyrolysis gas permeation and heat exchange, and thermochemical surface erosion. The numerical scheme utilizes a control-volume approach with a variable grid to account for surface movement. This method directly supports implementation of nontraditional models such as material swelling and mechanical erosion, extending capabilities for modeling complex ablation phenomena. Verifications of the numerical implementation are provided using analytical solutions, code comparisons, and the method of manufactured solutions. These verifications are used to demonstrate solution accuracy and proper error convergence rates. A simple demonstration of a mechanical erosion (spallation) model is also provided to illustrate the unique capabilities of the method

    Optimum community energy storage for renewable energy and demand load management

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    While the management of PV generation is the prime application of residential batteries, they can deliver additional services in order to help systems to become cost-competitive. They can level-out the demand and potentially reduce the cost and emissions of the energy system by reducing demand peaks. In this study, community energy storage (CES) is optimised to perform both PV energy time-shift and demand load shifting (using retail tariffs with varying prices blocks) simultaneously. The optimisation method obtains the techno-economic benefits of CES systems as a function of the size of the community ranging from a single home to a 100-home community in two different scenarios for the United Kingdom: the year 2020 and a hypothetical zero emissions target. It is demonstrated that the levelised cost and levelised value of CES systems reach intermediate values to those achieved when both applications are performed independently. For the optimal performance of a battery system being charged from both local PV plants and the grid, our results suggest that the battery should be sized suitable to ensure it can fully discharge during the peak period
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