192 research outputs found

    Elliptic flow from color strings

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    It is shown that the elliptic flow can be successfully described in the color string picture with fusion and percolation provided anisotropy of particle emission from the fused string is taken into account. Two possible sources of this anisotropy are considered, propagation of the string in the transverse plane and quenching of produced particles in the strong color field of the string. Calculations show that the second source gives an overwhelming contribution to the flow at accessible energies.Comment: 23 pages, 11 figure

    Updated opacities from the opacity project

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    Using the code autostructure, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. The results are used to obtain updated opacities from the Opacity Project (OP). A number of other improvements on earlier work have also been included. Rosseland-mean opacities from the OP are compared with those from OPAL. Differences of 5-10 per cent occur. The OP gives the 'Z-bump', at log(T) 5.2, to be shifted to slightly higher temperatures. The opacities from the OP, as functions of temperature and density, are smoother than those from OPAL. The accuracy of the integrations used to obtain mean opacities can depend on the frequency mesh used. Tests involving variation of the numbers of frequency points show that for typical chemical mixtures the OP integrations are numerically correct to within 0.1 per cent. The accuracy of the interpolations used to obtain mean opacities for any required values of temperature and density depends on the temperature-density meshes used. Extensive tests show that, for all cases of practical interest, the OP interpolations give results correct to better than 1 per cent. Prior to a number of recent investigations which have indicated a need for downward revisions in the solar abundances of oxygen and other elements, there was good agreement between properties of the Sun deduced from helioseismology and from stellar evolution models calculated using OPAL opacities. The revisions destroy that agreement. In a recent paper, Bahcall et al. argue that the agreement would be restored if opacities for the regions of the Sun with 2 × 106T 5 × 106 K (0.7-0.4 R) were larger than those given by OPAL by about 10 per cent. In the region concerned, the present results from the OP do not differ from those of OPAL by more than 2.5 per cent

    Anisotropic flows from colour strings: Monte-Carlo simulations

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    By direct Monte-Carlo simulations it is shown that the anisotropic flows can be successfully described in the colour string picture with fusion and percolation provided anisotropy of particle emission from the fused string is taken into account. Quenching of produced particles in the strong colour field of the string is the basic mechanism for this anisotropy. The concrete realization of this mechanism is borrowed from the QED. Due to dependence of this mechanism on the external field strength the found flows grow with energy, with values for v2v_2 at LHC energies greater by ~15% than at RHIC energies.Comment: New version with a non-static distribution of string

    The probiotic strain Shewanella putrefaciens Pdp11 strongly modulates gene expression of the fish pathogen Vibrio harveyi

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    In this work, the interaction between the fish probiotic Shewanella putrefaciens Pdp11 and the fish pathogen V. harveyi was studied by RNA-seq to understand how SpPdp11 interferes with the pathogen through bioinformatics analysis. Three types of cultures were performed: SpPdp11 alone, V. harveyi alone and SpPdp11 and V. harveyi together. RNA was extracted and sequenced (paired end, 2x75 bp) at the Ultrasequencing Service of the University of Málaga using the Illumina NextSeqTM 550 platform. Raw reads were processed using a bioinformatic pipeline and a network analysis was performed for the most relevant functional enrichment results. The results suggest that the presence of SpPdp11 affects V. harveyi to a greater extent than V. harveyi affects SpPdp11. Considering that V. harveyi is a pathogenic strain and SpPdp11 is a probiotic strain, this may be positive for its probiotic capacity, as it not only maintains its functionality almost intact, but also produces a huge imbalance in that of V. harveyiThis work was funded by project AG-2017-509 83370-C3-3-R (MINECO, Spain)

    Nitrogen K-shell photoabsorption

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    Reliable atomic data have been computed for the spectral modeling of the nitrogen K lines, which may lead to useful astrophysical diagnostics. Data sets comprise valence and K-vacancy level energies, wavelengths, Einstein AA-coefficients, radiative and Auger widths and K-edge photoionization cross sections. An important issue is the lack of measurements which are usually employed to fine-tune calculations so as to attain spectroscopic accuracy. In order to estimate data quality, several atomic structure codes are used and extensive comparisons with previous theoretical data have been carried out. In the calculation of K photoabsorption with the Breit--Pauli RR-matrix method, both radiation and Auger damping, which cause the smearing of the K edge, are taken into account. This work is part of a wider project to compute atomic data in the X-ray regime to be included in the database of the popular {\sc xstar} modeling code

    De semillas a bioenergía: un camino de conversión para la valorización de semillas de ricino y jatrofa

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    The world’s energy matrix can be diversified with biodiesel from castor and jatropha oil. Hence, the objective of this study was to assess a conversion path for the valorization of castor and jatropha seeds. The results showed the maximum extraction of castor oil at 90 °C, 2 rpm, and 6 mm nozzle, achieving a yield of 36.97% and for jatropha oil at 100 °C, 1.5 rpm, and 10 mm nozzle, achieving a yield of 20.11%. The acid value and cloud point of castor and jatropha oil were 0.797 and 23.44 mg KOH/g, 10±1 °C and 12±0.55 °C, respectively; while the pour point was -3 °C for both. The acid value and cloud point for biodiesels ranged from 0.26-0.43 mg KOH/g, and -12.50-6.10 °C, respectively. The viscosity of oils and biodiesel ranged from 0.02-1.3 P. GC-MS indicated 66.38% of methyl ricinoleate in castor biodiesel and 31.64% of methyl oleate in jatropha biodiesel. The HHV for castor and jatropha biodiesel ranged from 32.37-40.25 MJ/kg.La matriz energética mundial puede diversificarse con biodiesel de ricino y de jatrofa. Por lo tanto, el objetivo de este trabajo fue evaluar la ruta de conversión de las semillas de ricino y jatrofa. Los resultados mostraron que la máxima extracción de aceite de ricino se dio a 90 °C, 2 rpm, y boquilla de 6 mm, alcanzando un rendimiento de 36,97% y para el aceite de jatrofa fue a 100 °C, 1,5 rpm, y boquilla de 10 mm, obteniendo un rendimiento de 20,11%. El índice de acidez y punto de nube del aceite de ricino y jatrofa fue de 0,797 y 23,44 mg de KOH/g, 10 ± 1 °C y 12 ± 0,55 °C, respectivamente, mientras que el punto de fluidez fue de -3 °C para ambos. El índice de acidez y el punto de nube del biodiésel de ricino y jatropha fueron 0,43 y 0,26 mg KOH/g, -12,50 °C y 6,10 °C, respectivamente. La viscosidad dinámica de los aceites y el biodiesel osciló entre 0,02 y 1,3 P. El análisis GC-MS indicó 66,38% de ricinoleato de metilo en biodiesel de higuerilla y 31,64% de oleato de metilo en biodiesel de jatrofa. El HHV para el biodiésel de ricino y jatrofa osciló entre 32,37 y 40,25 MJ/kg

    Percolation of Color Sources and the determination of the Equation of State of the Quark-Gluon Plasma (QGP) produced in central Au-Au collisions at \sqrt S_{NN}= 200 GeV

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    The Color String Percolation Model (CSPM) is used to determine the equation of state (EOS) of the QGP produced in central Au-Au collisions at sNN\sqrt{s_{NN}} = 200 A GeV using STAR data at RHIC. When the initial density of interacting colored strings exceeds the 2D percolation threshold a cluster is formed, which defines the onset of color deconfinement. These interactions also produce fluctuations in the string tension which transforms the Schwinger particle (gluon) production mechanism into a maximum entropy thermal distribution. The single string tension is determined by identifying the known value of the universal hadron limiting temperature TcT_{c} = 167.7 ±\pm 2.6 MeV with the CSPM percolation temperature at the critical threshold ξc\xi_{c} =1.2. At mid-rapidity the initial Bjorken energy density and the initial temperature determine the number of degrees of freedom consistent with the formation of a \sim 2+1 flavor QGP. An analytic expression for the equation of state, the sound velocity Cs2(ξ)C_{s}^{2}(\xi) is obtained in CSPM. The CSPM Cs2(ξ)C_{s}^{2}(\xi) and the bulk thermodynamic values ε/T4\varepsilon /T^{4} and s/T3s /T^{3} are in excellent agreement in the phase transition region with recent lattice QCD simulations (LQCD) by the HotQCD Collaboration.Comment: 4 pages, 3 figure

    Atopic dermatitis incidence and risk factors in young adults in Castellon (Spain): A prospective cohort study

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    Introduction: There are few atopic dermatitis (AD) incidence cohort studies in young adults, the etiology of this disease remains obscure, and AD risk factors in adults are not well understood. The objective of this study was to estimate AD ten-year incidence and prevalence in a cohort of adolescent aged 14–16 at inception in Castellon province in Valencia Region, Spain and describe related risk factors. Material and methods: From 2002 to 2012, a population-based prospective cohort study was carried out. Questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC) were used with an additional questionnaire for related factors completed by participants and their parents, respectively, in 2002. In 2012 the same questionnaires were completed by the participants’ through a telephone interview, and incidence and prevalence of AD were estimated. Directed acyclic graphs, Poisson regression and inverse probability weighted regression adjustment were used. Results: The participation rate was 79.5% (1435/1805) with AD lifetime prevalence of 34.9% and AD incidence of 13.5 per 1000 person years. Females presented higher prevalence and incidence than males. After adjustment significant risk factors were being female, history of asthma or allergic rhinitis, family history of AD, history of respiratory infections, history of bronchitis, history of pneumonia, history of sinusitis, and birthplace outside Castellon province. The highest AD population attributable risks were female, 30.3%, and history of respiratory infections 15.3%. Differences with AD childhood risk factors were found. Conclusions: AD incidence in our cohort was high and several risks factors were related to AD

    AFBC of coal with tyre rubber. Influence of the co-combustion variables on the mineral matter of solid by-products and on Zn lixiviation

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    The study focuses on the generation and distribution of mineral species in fly and bottom ashes. These were formed during a fluidised co-combustion of a fossil fuel (coal) and a non-fossil fuel (tyre rubber) in a small fluidised bed combustor (7cm x 70cm). The pilot plant had continuous fuel feed using varying ratios of coal and rubber. The study also focuses on the lixiviation behaviour of metallic elements with the assessement of zinc recovering

    Trifoliata hybrids rootstocks for 'Lane Late' navel orange in Spain

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    Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] and Cleopatra mandarin (C. reshni Hort. ex Tan.) are the most important rootstocks used in Spain, but they are problematic and it is necessary to search for new rootstocks with better all-round performance. The performance of 'Lane Late' navel orange [Citrus sinensis (L.) Osb] on ten rootstocks was determined in the South of the province of Alicante (Spain). They are Carrizo citrange, Cleopatra mandarin and eight new hybrids obtained at the Instituto Valenciano de Investigaciones Agrarias in Valencia (Spain): 020324 [Troyer citrange (C. sinensis × P. trifoliata) × Cleopatra mandarin], Forner-Alcaide 418 (F&A 418) [Troyer citrange × common mandarin (C. deliciosa Ten.)], Forner-Alcaide 13 (F&A 13), 030118, 030127 and 030131 (Cleopatra mandarin × P. trifoliata) and 030212 and 030230 (Cleopatra mandarin × Troyer citrange). Soil is clay loam, with pH 8.5 and electric conductivity in the saturation extract at 25ºC of 5.79 mS cm-1. Yield was weighed during the first nine harvests, fruit quality was determined in the last three. Pre-harvest fruit-drop was controlled for the 4th until 9th harvests. The trees of 'Lane Late' navel budded on Cleopatra mandarin were the tallest (2.5 m) and F&A 418 (1.6 m) the shortest of all rootstocks tested. Trees on 030131 hybrid and Carrizo citrange rootstocks had the highest mean yield (81.2 and 80.3 kg per tree per year respectively), while trees on F&A 418 produced the lowest mean yield (22.3 kg per tree per year). Trees on 030131, 020324 and 030212 had the highest yield efficiency as total cumulative yield per cubic meter of canopy volume (62.1, 58.7 and 55.9 kg m-3 respectively) whereas trees on 030127, F&A 418 and Cleopatra mandarin had lower yield efficiencies (45.0, 44.4 and 38.6 kg m-3, respectively). Pre-harvest fruit-drop was lower in trees grafted on Cleopatra mandarin (24.62 %) and on 030212 (26.61 %), and was also low on F&A 418 (27.76 %), 020324 (28.14 %) and 030230 (29.18 %) rootstocks. Trees on Carrizo citrange and 030127 experienced important fruit-drop (40.24 % and 38.27 % respectively). Trees on F&A 418 had the highest fruit weight and fruit size whereas trees on 030118 induced the lowest ones. The ripeness index was the highest on F&A 13 (18.3) and lowest on F&A 418 (15.3), 030212 (15.3)
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