9,504 research outputs found

    Microalgal Growth in Paper Industry Effluent: Coupling Biomass Production with Nutrients Removal

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    Paper and pulp industries produce effluents with high phosphorus concentrations, which need to be treated before their discharge in watercourses. The use of microalgae for this purpose has attracted the attention of researchers because: (i) microalgae can assimilate phosphorus (one of the main nutrients for their growth); and (ii) growing on effluents can significantly reduce the costs and environmental impact of microalgal biomass production. This study evaluated the growth and ability of Chlorella vulgaris to remove the phosphorus from a secondary-treated effluent of a Portuguese paper company. Batch experiments were performed for 11 days using different dilutions of the effluent to evaluate its inhibitory effect on microalgae. Results showed that the non-diluted effluent inhibited microalgal growth, indicating that this bioremediation process is possible after a previous dilution of the effluent. Regarding phosphorus removal, promising results were achieved, especially in the experiments conducted with the most diluted effluent: removal efficiencies obtained in these conditions were (54 +/- 1)%. Another interesting finding of this study was microalgal growth in flakes' form (mainly due to the compounds present in the effluent and to the pH values achieved), which can be an important economic advantage for biomass recovery after the remediation step

    Numerical Analysis of a Swirl Stabilized Premixed Combustor with the Flamelet Generated Manifold approach

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    In this paper the effectiveness of LES for modeling premixed methane combustion will be investigated in the context of gas turbine modeling. The required reduction of the chemistry is provided by the flamelet generated manifold (FGM) approach of van Oijen (2002). For turbulence-chemistry interactions an algebraic model is used to calculate variations which are used to invoke a pre-assumed pdf, Vreman et al. (2009). The algebraic model has a tunable parameter

    Complex coastal change in response to autogenic basin infilling: An example from a sub-tropical Holocene strandplain

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    Thick bay-fill sequences that often culminate in strandplain development serve as important sedimentary archives of land-ocean interaction, although distinguishing between internal and external forcings is an ongoing challenge. This study employs sediment cores, ground-penetrating radar surveys, radiocarbon dates, palaeogeographic reconstructions and hydrodynamic modelling to explore the role of autogenic processes - notably a reduction in wave energy in response to coastal embayment infilling - in coastal evolution and shoreline morphodynamics. Following a regional 2 to 4m highstand at ca 58ka, the 75km(2) Tijucas Strandplain in southern Brazil built from fluvial sediments deposited into a semi-enclosed bay. Holocene regressive deposits are underlain by fluvial sands and a Pleistocene transgressive-regressive sequence, and backed by a highstand barrier-island. The strandplain is immediately underlain by 5 to 16m of seaward-thickening, fluvially derived, Holocene-age, basin-fill mud. Several trends are observed from the landward (oldest) to the seaward (youngest) sections of the strandplain: (i) the upper shoreface and foreshore become finer and thinner and shift from sand-dominated to mud-dominated; (ii) beachface slopes decrease from \u3e11 degrees to ca 7 degrees; and (iii) progradation rates increase from 04 to 18myr(-1). Hydrodynamic modelling demonstrates a correlation between progressive shoaling of Tijucas Bay driven by sea-level fall and sediment infilling and a decrease in onshore wave-energy transport from 18 to 4kWm(-1). The combination of allogenic (sediment supply, falling relative sea-level and geology) and autogenic (decrease in wave energy due to bay shoaling) processes drove the development of a regressive system with characteristics that are rare, if not unique, in the Holocene and rock records. These findings demonstrate the complexities in architecture styles of highstand and regressive systems tracts. Furthermore, this article highlights the diverse internal and external processes and feedbacks responsible for the development of these intricate marginal marine sedimentary systems

    Production of bacteriocin-like inhibitory substances (BLIS) by Bifidobacterium lactis using whey as a substrate

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    The objective of this work was to evaluate the production of bacteriocin-like inhibitory substances (BLIS) by Bifidobacterium animalis subsp. lactis in whey supplemented with yeast extract, inulin, Tween 80 or L-cysteine. Cell growth, acidification, glucose and lactose consumption as well as BLIS production were measured during fermentations carried out in shake flasks. The best additive for both cell growth and BLIS production was shown to be yeast extract, which gave the highest concentrations of biomass (9.9 log CFU/mL) and BLIS (800 AU/mL). In a bench-scale fermenter, B. lactis growth and BLIS production were between 6 and 25 % higher than in flasks depending on the conditions assayed

    Assessing Islamic religious education curriculum in Flemish public secondary schools

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    Islamic tradition promotes a holistic approach of personality development in which, we argue, three educational concepts take the centre stage: tarbiyah, ta’leem and ta’deeb. Looking through the lens of these concepts, we analyse two Islamic religious education (IRE) curricula: the 2001 and 2012 curricula for Flemish public secondary education provided by the Representative Body for IRE. We conduct a systematic thematic document analysis of the 2001 and 2012 curricula to map curricula elements that potentially contribute to Islamic personality development through IRE classes. Crucially, this article seeks to investigate whether the 2001 and 2012 curricula for Flemish public secondary education are in line with these central IRE concepts. We observe that the 2012 curriculum does contain relevant anchor points to work on tarbiyah, ta’leem and ta’deeb and to strengthen an Islamic personality in Muslim pupils. Hence, we argue that there is an urgent need for a new, adequate and sufficiently comprehensive IRE curriculum for Flemish public secondary education, developed by an expert committee—which should include Belgian-educated educational experts—in order to meet the expectations of all the stakeholders. Since in our view, this is the first step for a qualitative update of Flemish IRE. Further reflections on both curricula and recommendations for a new IRE curriculum are outlined in the discussion and conclusion sections

    Reaction mechanisms in the 6Li+59Co system

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    The reactions induced by the weakly bound 6Li projectile interacting with the intermediate mass target 59Co were investigated. Light charged particles singles and α\alpha-dd coincidence measurements were performed at the near barrier energies E_lab = 17.4, 21.5, 25.5 and 29.6 MeV. The main contributions of the different competing mechanisms are discussed. A statistical model analysis, Continuum-Discretized Coupled-Channels calculations and two-body kinematics were used as tools to provide information to disentangle the main components of these mechanisms. A significant contribution of the direct breakup was observed through the difference between the experimental sequential breakup cross section and the CDCC prediction for the non-capture breakup cross section.Comment: 30 pages, 8 figure

    The KASCADE-Grande experiment

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    KASCADE-Grande is the enlargement of the KASCADE extensive air shower detector, realized to expand the cosmic ray studies from the previous 1014–1017 eV primary energy range to 1018 eV. This is performed by extending the area covered by the KASCADE electromagnetic array from 200×200 to 700×700 m2 by means of 37 scintillator detector stations of 10 m2 area each. This new array is named Grande and provides measurements of the all-charged particle component of extensive air showers (Nch), while the original KASCADE array particularly provides information on the muon content (Nμ)(Nμ). Additional dense compact detector set-ups being sensitive to energetic hadrons and muons are used for data consistency checks and calibration purposes. The performance of the Grande array and its integration into the entire experimental complex is discussed. It is demonstrated that the overall observable resolutions are adequate to meet the physical requirements of the measurements, i.e. primary energy spectrum and elemental composition studies in the primary cosmic ray energy range of 1016–1018 eV.MIURBMBFINAFEntre outra

    ADJUSTMENT OF SOIL SOLUTE TRANSPORT PARAMETERS WITH MATLAB 6.5

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    The successful use of mathematical models in studies of solute transport in soil is dependent on the accuracy to which the transport parameters involved in this process can be specified. In general, these parameters are determined by using nonlinear optimization techniques to fit theoretical models to experimental data obtained in miscible displacement experiments. The use, therefore, of high-performance software to evaluate these parameters appears to be advantageous since, in addition to consistency and the availability of pre-existing numerical routines, such software allows for the incorporation of new routines that are specifically tailored for the phenomena being simulated. The main objective of this study was to develop a MATLAB 6.5 computational routine to optimize the evaluation of retardation factor (R) and dispersion coefficient (D) from miscible displacement data. This routine was applied to experimental data from three miscible displacement studies of potassium transport in columns filled with an Oxisol of sandy phase, with the setting quality being assessed by the coefficient of accuracy. The proposal routine gave excellent results, reinforcing the consistency of the numerical method used, and indicating that this routine can contribute to the advancement of theoretical studies of the solute-water dynamics in unsaturated porous media.3161064107
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