98 research outputs found

    Adsorption of 2, 4 dinitrophenol from aqueous solutions using ordered mesoporous carbon CMK-3

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    Background and purpose: 2, 4 dinitrophenol is the most important nitrophenol compound that is widely used in paints, adhesives, wood preservatives, solvents, pesticides, and explosive materials. Because of the high toxicity and non-biodegradability of 2, 4 DNP, must be prevented from entering the water body. The aim of this study was to evaluate the performance of ordered mesoporous carbon CMK-3 in adsorption of 2, 4 dinitrophenol from aqueous solutions and the effect of various parameters on the performance of this process. Materials and methods: In this experimental study, mesoporous carbon, CMK-3 was prepared using hexagonal SBA-15 mesoporous silica in a batch reactor. The synthesized materials were characterized by XRD, BET and TEM. After Synthesis of CMK-3, the effect of different parameters were investigated on adsorption process including pH (3-11), contact time (20 -180 min) initial concentration of 2, 4 dinitrophenol (10-500mg/L), and adsorbent dose (0.2-1.2 gr/L). Results: Removal efficiency increased when pH and initial concentration of 2, 4-dinitrophenol decreased and contact time and adsorbant doze increased. The optimum pH was 5 and the equilibrium time was 100 minutes. The optimal dose of CMK-3 was 0.4 g/L and the adsorption capacity of 2, 4 dinitrophenol by CMK-3 was 194 mg/g. Conclusion: In general, mesoporous carbon CMK-3 showed high capacity in removal of 2,4 dinitrophenol from aqueous solutions. Therefore, it can be used in the treatment of wastewater containing 2,4 dinitrophenol. © 2016, Mazandaran University of Medical Sciences. All rights reserved

    Application of ion exchange and air stripping methods to remove ammonium in recirculation fish culture system effluents

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    Increase in water pH in recirculation fish culture systems turns ammonium into ammonia which can kill fish even in low concentrations. The purpose of this study was to apply ion exchange and air stripping methods to remove ammonium in effluents of recirculation fish culture systems. Ion exchange method was done using Graded Zeolite Clinoptilolite from Semnan Province to remove ammonium and air stripping was applied to zap ammonium from Zeoilte. Regeneration tests were conducted in which known weights of ammonium saturated Clinoptilolite were contacted with 1 normal concentration of CINa solution. Different concentrations of ammonium were selected and the effects of temperature and pH in releasing ammonia were also investigated. Results show that the cation exchange capacities in continuous systems were 7.61 to 11.22 (in breakthrough point) and 16.31 to 19.5mg ammonium per gram of ion exchanger as total capacity. The results of regeneration experiments by NaCI (1 normal) solution proved the efficiency of chemical regeneration of zeolite column to be as high as 94.9% to 99.1%. The efficiency of regeneration by air stripping was determined to be 92% in 16 hours. The efficiency of acid absorption of released ammonia in stripping process was determined as 55% where the surplus was rejected to the atmosphere. It is concluded that the method may be regarded as a completing process for water treatment in closed fish tanks

    Influence of soy oil source and supplementation of the diet with vitamin E and vi tamin C on performance and egg quality of Single Comb White Leghourn lyaing hens from forty four to fity six weeks of age

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    Two experiments (Exp.) were conducted to determine the AME content of refined soybean oil (SO), recycled soybean oil (RSO), and acidulated soybean oil soapstocks (ASO) and the effects of inclusion of vitamin E and vitamin C in diets containing 3.5% of these soy oils on performance and egg quality of Hy-line hens from 44 to 56 wks of age

    Determinación del contenido en energía metabolizable de distintas fuentes de lípidos procedentes de la industria del aceite de soja

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    Los aceites vegetales se utilizan en la alimentación de gallinas ponedoras para aumentar la concentración energética de los piensos y como fuente de ácido linoleico. Además, Mateos y Sell (1981) han demostrado que la inclusión de grasas ralentiza la velocidad de tránsito de la digesta lo que favorece el contacto entre los nutrientes de la dieta y las enzimas digestivas, mejorando su utilización digestiva. Como consecuencia, la inclusión de grasas es una práctica común en la formulación de piensos comerciales para aves de puesta. El aceite de soja (AS) debido a su alto contenido energético y en ácido linoleico es el aceite de elección en piensos para avicultura pero su alto coste limita su utilización en piensos comerciales. Dos co-productos de la industria del aceite de soja, las oleínas (OAS) y el aceite de freiduría (ASR) podrían sustituir al AS en piensos para avicultura. El objetivo de este trabajo es determinar el contenido en energía metabolizable aparente (EMA) de estos aceites y comparar los resultados obtenidos utilizando dos metodologías de cálculo

    Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

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    Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe

    Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

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    The second-order Fourier coefficients (υ2_{2}) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb1^{-1}. The scalar product method is used to extract the υ2_{2} coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < pT_{T} < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ2_{2} values for the Υ mesons are found to be consistent with zero

    Measurement of prompt D0^{0} and D\overline{D}0^{0} meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root SNN\sqrt{S_{NN}} = 5.02 TeV

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    The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licens

    Performance of reconstruction and identification of τ leptons decaying to hadrons and vτ in pp collisions at √s=13 TeV

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    The algorithm developed by the CMS Collaboration to reconstruct and identify τ leptons produced in proton-proton collisions at √s=7 and 8 TeV, via their decays to hadrons and a neutrino, has been significantly improved. The changes include a revised reconstruction of π⁰ candidates, and improvements in multivariate discriminants to separate τ leptons from jets and electrons. The algorithm is extended to reconstruct τ leptons in highly Lorentz-boosted pair production, and in the high-level trigger. The performance of the algorithm is studied using proton-proton collisions recorded during 2016 at √s=13 TeV, corresponding to an integrated luminosity of 35.9 fb¯¹. The performance is evaluated in terms of the efficiency for a genuine τ lepton to pass the identification criteria and of the probabilities for jets, electrons, and muons to be misidentified as τ leptons. The results are found to be very close to those expected from Monte Carlo simulation

    Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

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    At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 1034^{34} cm2^{-2}s1^{-1}, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals

    Studies of charm and beauty hadron long-range correlations in pp and pPb collisions at LHC energies

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