16 research outputs found

    A Practical Approach for Biochemical Modeling in the CFD Evaluation of Novel Anaerobic Digester Concepts for Biogas Production

    Get PDF
    The detailed physics-based description of anaerobic digesters is characterized by their multiscale and multiphysics nature, with Computational Fluid Dynamics (CFD) simulations being the most comprehensive approach. In practice, difficulties in obtaining a detailed characterization of the involved biochemical reactions hinder its application in the design of novel reactor concepts, where all physics interplays in the reactor must be considered. To solve this limitation, a practical approach is introduced where a calibration step using actual process data was applied for the simplified biochemical reactions involved, allowing us to efficiently manage uncertainties arising when characterizing biochemical reactions with lab scale facilities. A complete CFD modeling approach is proposed for the anaerobic digestion of wastewater, including heat transfer and multiphasic flow. The proposed multiphase model was verified using reference data and, jointly with the biochemical modeling approach, applied to a lab-scale non-conventional anaerobic digester for winery wastewater treatment. The results showed qualitative improvement in predicting methane production when the diameter of the particles was reduced, since larger particles tend to move downwards. The biochemistry of the process could be simplified introducing a preexponential factor of 380 (kmol/m3)(1 – n)/s for each considered chemical reaction. In general, the proposed approach can be used to overcome limitations when using CFD to scale-up optimization of non-conventional reactors involving biochemical reactions

    Characterization of endosperm proteins and bread-making quality in wheat breeding lines carrying resistance genes for Mayetiola destructor and/or Heterodera avenae.

    Get PDF
    The experimental material included thirteen bread wheat-breeding lines that carry genes for resistance to M. destruc¬tor and/or H. avenae. The sources of these resistances are the wild species Ae. triuncialis and Ae. ventricosa (lines TR and H-93, respectively) (Delibes et al. 1993, 1997; Romero et al. 1998). We have determined the composition in HMW-glutenin subunits (related with bread-making quality), puroindoline proteins (related with hardness of grain), and waxy proteins (related with starch viscosity). In addition to, of prolamins by electrophoresis SDS-PAGE indicated the homogeneity of the lines

    The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

    Full text link
    WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366-959\,nm at R5000R\sim5000, or two shorter ranges at R20000R\sim20\,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for \sim3 million stars and detailed abundances for 1.5\sim1.5 million brighter field and open-cluster stars; (ii) survey 0.4\sim0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey 400\sim400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z<0.5z<0.5 cluster galaxies; (vi) survey stellar populations and kinematics in 25000\sim25\,000 field galaxies at 0.3z0.70.3\lesssim z \lesssim 0.7; (vii) study the cosmic evolution of accretion and star formation using >1>1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z>2z>2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.Comment: 41 pages, 27 figures, accepted for publication by MNRA

    The wide-field, multiplexed, spectroscopic facility WEAVE : survey design, overview, and simulated implementation

    Get PDF
    Funding for the WEAVE facility has been provided by UKRI STFC, the University of Oxford, NOVA, NWO, Instituto de Astrofísica de Canarias (IAC), the Isaac Newton Group partners (STFC, NWO, and Spain, led by the IAC), INAF, CNRS-INSU, the Observatoire de Paris, Région Île-de-France, CONCYT through INAOE, Konkoly Observatory (CSFK), Max-Planck-Institut für Astronomie (MPIA Heidelberg), Lund University, the Leibniz Institute for Astrophysics Potsdam (AIP), the Swedish Research Council, the European Commission, and the University of Pennsylvania.WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366-959 nm at R ∼ 5000, or two shorter ranges at R ∼ 20,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∼ 3 million stars and detailed abundances for ∼ 1.5 million brighter field and open-cluster stars; (ii) survey ∼ 0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey  ∼ 400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z 1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z > 2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.PostprintPeer reviewe

    The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

    Get PDF
    WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−959\,nm at R∼5000, or two shorter ranges at R∼20000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∼3 million stars and detailed abundances for ∼1.5 million brighter field and open-cluster stars; (ii) survey ∼0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey ∼400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z>2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator

    Potential of CO2 capture from flue gases by physicochemical and biological methods: a comparative study

    No full text
    The industrial viability of two emerging technologies for CO2 capture from flue gases, i.e., adsorption in porous commercial zeolites and biomass production by microalgae, is compared. Our study is organized in two steps: first, the best system is selected (either zeolite type or microalgae strain). Second, their performance is quantified and their advantages at real conditions discussed. For the physicochemical process, we find that commercial zeolite MFI is the best choice for CO2 capture from a typical industrial flue gas emission. Numerical dual PSA cycle simulations at ambient conditions yield 8 kg m-3 bed h-1 and an energy consumption of 0.987 MJ per kg of captured CO2. As regards the biological process, evaluation of several microalgae strains in continuous mode using low cost resources (waste water, fertilizers, flue gases), results in Scenedesmus almeriensis as the most promising strain. The maximal capacity of CO2 capture at laboratory conditions was 0.1 kg m-3 h -1 , allowing to produce up to 0.06 of kg m-3 h -1 of biomass (3% maximal photosynthetic efficiency). Although this is a significantly lower value, the produced biomass, being composed by carbohydrates, entails an overall economic yield of 0.6 € m- 3 ·day. To demonstrate reliability at large scale, experiments were performed in a 100 m2 pilot raceway reactor under outdoor conditions. We measured 54 g of CO2/m2 ·day (= 197 tn/ha·year) and a biomass productivity of 21 g/m2·day (= 75 tn/ha·year). The energy consumption approaches to 0.48 MJ/kgCO2, lower than zeolites adsorption. Still, zeolites can be advantageous as they offer higher productivity, lower energy consumption than amines-based methods, and possibility of producing added-value chemical products, such as methanol, CO or CH4
    corecore