388 research outputs found

    Modeling and Simulation of an Oxygen Delignification Industrial Process of Cellulosic Pulp using Kinetic Expressions and the software CADSIM Plus

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    <p>The Brazilian productive sector of pulp and paper represents a relevant contribution for the development of Brazil. To increase the competitiveness of Brazilian companies to an International level, products must have high standards of quality and high added value. Thus, the mathematical modeling and simulation of industrial processes ensures the stability of production. This study presents the fit of mathematical models for the Oxygen Delignification process of eucalyptus pulp of the industry Klabin Monte Alegre. The mathematical model estimates the kappa number after the reactor, based on two kinetic models given by the literature, one of these models considers oxygen excess in the reaction medium. The models showed a mean relative error of 10 %. The adjustment of the kinetic parameters equations was done in Matlab software, using classical methods of optimization, such as BFGS, DFP, Steepest Descent, Gauss Newton, Simplex and Levenberg Marquardt. The models were incorporated in the commercial simulator CADSIM Plus to provide an optimization tool to the pulp industries. The simulator predicts the kappa number after the Oxygen Delignification reactor. The results of the phenomenological models indicate that possibly there is excess of oxygen in the reaction media. Only the model that considered the presence of the oxygen in the kinetic equation was able to be implemented in the simulator CADSIM Plus, generating consistent results, with an absolute error of ± 2 kappa number. Application: The kinetic model applied to the CADSIM Plus software in this study may be used to optimize the Oxygen Delignification process either by reducing chemical consumptions or by testing different process conditions without changing production.</p&gt

    Analysis of Mechanical Response during Folding of Creased and Uncreased Paperboard

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    Creasing and folding of paperboard are two essential operations to obtain a well-defined shape and strength of a package. Relative Crease Strength, RCS, is specified for process control of creasing and folding and is defined as the ratio between the maximal bending force for a crease and uncreased sample bend to the bending angle of 30 degrees at a rate of 5 degrees/sec. Thus, the present work had as objective to evaluate RCS measured in real industrial samples used for process control of creasing and evaluate the influence of paperboard properties and converting processes creasing and folding. As RCS can be measured only after creasing, the study can give directions to paperboard production process control. Creasing measurements were done on both machine direction (MD) and cross machine direction (CD) samples. The paperboard property that showed the highest correlation to RCS was Scott Bond. Based on this one pilot production with lower Scott Bond was evaluated. Lower values of RCS were obtained, as predicted. X-Ray microtomography revealed higher stratification between fiber layers in the paperboard with lower Scott Bond

    Cosmology with a TeV mass GUT Higgs

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    The most natural way to break the GUT gauge symmetry is with a Higgs field whose vacuum expectation value is of order 10^{16}\,\mbox{GeV} but whose mass is of order 10210^2 to 10^3\,\mbox{GeV}. This can lead to a cosmological history radically different from what is usually assumed to have occurred between the standard inflationary and nucleosynthesis epochs, which may solve the gravitino and Polonyi/moduli problems in a natural way.Comment: 4 pages, revte

    Neuroplastinβ-mediated upregulation of solute carrier family 22 member 18 antisense (SLC22A18AS) plays a crucial role in the epithelial-mesenchymal transition, leading to lung cancer cells' enhanced motility

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    Our recent study revealed an important role of the neuroplastin (NPTN)β downstream signal in lung cancer dissemination in the lung. The molecular mechanism of the signal pathway downstream of NPTNβ is a serial activation of the key molecules we identified: tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) adaptor, nuclear factor (NF)IA/NFIB heterodimer transcription factor, and SAM pointed-domain containing ETS transcription factor (SPDEF). The question of how dissemination is controlled by SPDEF under the activated NPTNβ has not been answered. Here, we show that the NPTNβ-SPDEF-mediated induction of solute carrier family 22 member 18 antisense (SLC22A18AS) is definitely required for the epithelial-mesenchymal transition (EMT) through the NPTNβ pathway in lung cancer cells. In vitro, the induced EMT is linked to the acquisition of active cellular motility but not growth, and this is correlated with highly disseminative tumor progression in vivo. The publicly available data also show the poor survival of SLC22A18AS-overexpressing lung cancer patients. Taken together, these data highlight a crucial role of SLC22A18AS in lung cancer dissemination, which provides novel input of this molecule to the signal cascade of NPTNβ. Our findings contribute to a better understanding of NPTNβ-mediated lung cancer metastasis

    Thermal Inflation and the Moduli Problem

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    In supersymmetric theories a field can develop a vacuum expectation value M103GeVM \gg 10^3\,{\rm GeV}, even though its mass mm is of order 10210^2 to 103GeV10^3\,{\rm GeV}. The finite temperature in the early Universe can hold such a field at zero, corresponding to a false vacuum with energy density V0m2M2 V_0 \sim m^2 M^2 . When the temperature falls below V01/4V_0^{1/4}, the thermal energy density becomes negligible and an era of thermal inflation begins. It ends when the field rolls away from zero at a temperature of order mm, corresponding to of order 10 ee-folds of inflation which does not affect the density perturbation generated during ordinary inflation. Thermal inflation can solve the Polonyi/moduli problem if MM is within one or two orders of magnitude of 1012GeV10^{12}\,{\rm GeV}.Comment: Revised version to appear in Phys Rev D. Improved discussion of the possible effect of parametric resonance. Latex, 31 page

    Accelerating Universe and Cosmological Perturbation in the Ghost Condensate

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    In the simplest Higgs phase of gravity called ghost condensation, an accelerating universe with a phantom era (w<-1) can be realized without ghost or any other instabilities. In this paper we show how to reconstruct the potential in the Higgs sector Lagrangian from a given cosmological history (H(t), \rho(t)). This in principle allows us to constrain the potential by geometrical information of the universe such as supernova distance-redshift relation. We also derive the evolution equation for cosmological perturbations in the Higgs phase of gravity by employing a systematic low energy expansion. This formalism is expected to be useful to test the theory by dynamical information of large scale structure in the universe such as cosmic microwave background anisotropy, weak gravitational lensing and galaxy clustering.Comment: 30 pages; typos corrected; version accepted for publication in JCA

    The WiggleZ Dark Energy Survey: the growth rate of cosmic structure since redshift z=0.9

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    We present precise measurements of the growth rate of cosmic structure for the redshift range 0.1 < z < 0.9, using redshift-space distortions in the galaxy power spectrum of the WiggleZ Dark Energy Survey. Our results, which have a precision of around 10% in four independent redshift bins, are well-fit by a flat LCDM cosmological model with matter density parameter Omega_m = 0.27. Our analysis hence indicates that this model provides a self-consistent description of the growth of cosmic structure through large-scale perturbations and the homogeneous cosmic expansion mapped by supernovae and baryon acoustic oscillations. We achieve robust results by systematically comparing our data with several different models of the quasi-linear growth of structure including empirical models, fitting formulae calibrated to N-body simulations, and perturbation theory techniques. We extract the first measurements of the power spectrum of the velocity divergence field, P_vv(k), as a function of redshift (under the assumption that P_gv(k) = -sqrt[P_gg(k) P_vv(k)] where g is the galaxy overdensity field), and demonstrate that the WiggleZ galaxy-mass cross-correlation is consistent with a deterministic (rather than stochastic) scale-independent bias model for WiggleZ galaxies for scales k < 0.3 h/Mpc. Measurements of the cosmic growth rate from the WiggleZ Survey and other current and future observations offer a powerful test of the physical nature of dark energy that is complementary to distance-redshift measures such as supernovae and baryon acoustic oscillations.Comment: 17 pages, 11 figures, accepted for publication by MNRA

    Evidence of a landlocked reproducing population of the marine pejerrey Odontesthes argentinensis (Actinopterygii; Atherinopsidae)

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    In South America, the order Atheriniformes includes the monophyletic genus Odontesthes with 20 species that inhabit freshwater, estuarine and coastal environments. Pejerrey Odontesthes argentinensis is widely distributed in coastal and estuarine areas of the Atlantic Ocean and is known to foray into estuaries of river systems, particularly in conditions of elevated salinity. However, to our knowledge, a landlocked self‐sustaining population has never been recorded. In this study, we examined the pejerrey population of Salada de Pedro Luro Lake (south‐east of Buenos Aires Province, Argentina) to clarify its taxonomic identity. An integrative taxonomic analysis based on traditional meristic, landmark‐based morphometrics and genetic techniques suggests that the Salada de Pedro Luro pejerrey population represents a novel case of physiological and morphological adaptation of a marine pejerrey species to a landlocked environment and emphasises the environmental plasticity of this group of fishesFil: Colautti, Dario César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Miranda, Leandro Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: González Castro, M.. Universidad Nacional de Mar del Plata; ArgentinaFil: Villanova, Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Strüssmann, Carlos A.. Tokyo University Of Marine Science And Technology; JapónFil: Mancini, Miguel Alberto. Universidad Nacional de Río Cuarto; ArgentinaFil: Maiztegui, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Berasain, Gustavo. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios; ArgentinaFil: Hattori, Ricardo Shohei. Tokyo University of Marine Science and Technology; JapónFil: Grosman, Manuel Fabián. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Sanzano, Pablo Miguel. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Lozano, I.. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llamazares Vegh, Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salinas, V.. Universidad Nacional de Río Cuarto; ArgentinaFil: Del Ponti, O.. Universidad Nacional de La Pampa; ArgentinaFil: Fresno, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Minotti, Priscilla Gail. Universidad Nacional de San Martín; ArgentinaFil: Yamamoto, Y.. Tokyo University Of Marine Science And Technology; JapónFil: Baigún, C.. Universidad Nacional de San Martín; Argentin

    EXPRESS: Atomic Absorption Spectrometry Methods to Access the Metal Solubility of Aerosols in Artificial Lung Fluid

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    Recent studies to quantify the health risks that fine particulate matter with anaerodynamic lessthan 2.5 micrometers (PM2.5) poseuse in vitro approaches. One of these approaches is to incubate PM2.5in artificial lysosomal fluid for a given period at body temperature. These body fluids used have a high ionic strength and as such can be challenging samples to analyzewith atomic spectroscopy techniques. AsPM2.5isaprimary healthhazard because it is tiny enough to penetrate deep into the lungsand could, in addition, dissolve in the lung fluid it is important to quantify elements of toxic and/or carcinogenic concerns, reliably and accurately. Sophisticated instrumentation and expensive pre-treatment of challenging samples are not always available, especially in developing countries. Toevaluatethe applicability of GFAAS without Zeeman correction capability to detect trace quantities of heavy metals leached from PM2.5on to artificial lungfluid, uni-and multivariate approaches have been used for optimization purposes. The limits of quantification, LOQ,obtained by theoptimizedmethod were:2μgL-1(Cu), 3μg L-1(Cr), 1μg L-1(Mn) and 10μg L-1(Pb). The addition/recovery experiments had amean accuracy of: (Cu) 99 ± 7%; 110± 8% (Cr); 95 ± 9% (Mn) and 96 ± 11% (Pb). The average soluble fractions of PM2.5incubated in artificial lysosomal fluid (ALF)for 1 hour were:1.2 0.01ng m-3Cu, 0.40.01ng m-3Cr,0.60.01ng m-3Mnand4.8 0.03ng m-3Pb.Using historical elemental 2averagesof PM2.5 in Curitiba(Cu 3.3 ng m-3, Cr 2.1 ng m-3, Mn 6.1 ng m-3, Pb 21 ng m-3), the percentage bioaccessibility were determined to beCu 38%; Cr 20%; Mn 10%; and Pb 23%.The elemental values of the atmospheric soluble fraction of Cu, Cr and,Mn were below the inhalation risk concentrations.However, for Pb, the atmospheric soluble fraction exceeded the inhalation unit risk of 0.012 ng m-3.This robust and straightforward GF AASmethod is pivotal for low and middle-income countries were most air pollution adverse effects occur andestablished lower-costtechnologies are likelyunavailable

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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