79 research outputs found

    Removal of hazardous material from wastewater by using metal organic framework (MOF) embedded polymeric membranes

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    © 2018, © 2018 Taylor & Francis. Heavy metals in wastewater can cause acute and chronic toxicity which leads to learning disabilities, cancer, and even death. In the present work, Zn-based MOF (MOF-5) was prepared, and it is characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscope (SEM) analyses. MOF-5-incorporated polymeric membranes (polyethersulfone [PES], cellulose acetate [CA], and polyvinylidene fluoride [PVDF]) prepared by phase inversion method. The morphology, hydrophilicity, porosity, permeation performance, antifouling properties, and the rejection of Cu (II) and Co (II) metal ions of the membranes were significantly improved with the addition of MOF-5. Higher rejection efficiency for Co (II) in PES/MOF-5 and CA/MOF-5 was found to be 74.40% and 77%, respectively

    Influences of nano zero valent ion of kaolin and Fe2+ supported kaolin nanoparticles for metal ion separation thorough ultrafiltration

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    In this work, clay based nanocomposite material was synthesized by wet chemical route and nano zero valent ion of kaolin (nZVI:Kaolin) were prepared using sodium borohydride reduction method. The nZVI:Kaolin and Fe:Kaolin nanoparticles were characterized using XRD, FTIR and SEM and antimicrobial activity. The nZVI:Kaolin and Fe:Kaolin were incorporated into polyethersulfone (PES) membranes for metal ion separation through ultrafiltration. The influences of nZVI:Kaolin and Fe supported clay nanoparticles on PES membranes were characterized their modification in functional properties, hydrophilicity and morphological structure. The clean water flux was enhanced to PES membrane by addition of nZVI:Kaolin and Fe:Kaolin nanoparticles. The Cu (ii), Ni (ii) and Cd (ii) metal ions flux was increased for 0.15 wt% of nZVI and Fe:Kaolin nanoparticles in PES which is due to increase in hydrophilicity and change in morphological structure

    Identifying LISA verification binaries among the Galactic population of double white dwarfs

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    Double white dwarfs (DWDs) will be the most numerous gravitational-wave (GW) sources for the Laser Interferometer Space Antenna (LISA). Most of the Galactic DWDs will be unresolved and will superpose to form a confusion noise foreground, the dominant LISA noise source around 0.53mHz\sim 0.5\mathrm{-}3\,\mathrm{mHz}. A small fraction of these sources will stand out from the background and be individually detectable. Uniquely among GW sources, a handful of these binaries will be known in advance from electromagnetic (EM) observations and will be guaranteed sources of detectable GWs in the LISA band; these are known as verification binaries (VBs). High-cadence photometric surveys are continuously discovering new VB systems, and their number will continue to grow ahead of the launch of LISA. We analyse, in a fully Bayesian framework, all the currently known VB candidates with the latest design requirements for the LISA mission and find that 25 of the considered sources can be detected within a 4yr4\,\mathrm{yr} observation time. We explore what can be expected from GW observations, both alone and in combination with EM observations, and estimate the VB's time to detection in the early months of LISA operations. We also show how VBs can be analysed in the case where their GW signals compete with many other unknown binary signals (both resolved and unresolved) from a realistic Galactic population of DWDs

    Consistency tests of AMPCALCULATOR and chiral amplitudes in SU(3) Chiral Perturbation Theory: A tutorial based approach

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    Ampcalculator is a Mathematica based program that was made publicly available some time ago by Unterdorfer and Ecker. It enables the user to compute several processes at one-loop (upto O(p4)O(p^4)) in SU(3) chiral perturbation theory. They include computing matrix elements and form factors for strong and non-leptonic weak processes with at most six external states. It was used to compute some novel processes and was tested against well-known results by the original authors. Here we present the results of several thorough checks of the package. Exhaustive checks performed by the original authors are not publicly available, and hence the present effort. Some new results are obtained from the software especially in the kaon odd-intrinsic parity non-leptonic decay sector involving the coupling G27G_{27}. Another illustrative set of amplitudes at tree level we provide is in the context of τ\tau-decays with several mesons including quark mass effects, of use to the BELLE experiment. All eight meson-meson scattering amplitudes have been checked. Kaon-Compton amplitude has been checked and a minor error in published results has been pointed out. This exercise is a tutorial based one, wherein several input and output notebooks are also being made available as ancillary files on the arXiv. Some of the additional notebooks we provide contain explicit expressions that we have used for comparison with established results. The purpose is to encourage users to apply the software to suit their specific needs. An automatic amplitude generator of this type can provide error-free outputs that could be used as inputs for further simplification, and used in varied scenarios such as applications of chiral perturbation theory at finite temperature, density and volume. This can also be used by students as a learning aid in low-energy hadron dynamics.Comment: 25 pages, plain latex, corresponds to version to appear in EPJA, additional ancillary files adde

    Model independent bounds on the modulus of the pion form factor on the unitarity cut below the ωπ\omega\pi threshold

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    We calculate upper and lower bounds on the modulus of the pion electro magnetic form factor on the unitarity cut below the ωπ\omega\pi inelastic threshold, using as input the phase in the elastic region known via the Fermi-Watson theorem from the ππ\pi\pi PP-wave phase shift, and a suitably weighted integral of the modulus squared above the inelastic threshold. The normalization at t=0t=0, the pion charge radius and experimental values at spacelike momenta are used as additional input information. The bounds are model independent, in the sense that they do not rely on specific parametrizations and do not require assumptions on the phase of the form factor above the inelastic threshold. The results provide nontrivial consistencychecks on the recent experimental data on the modulus available below the ωπ\omega\pi threshold from e+ee^+ e^- annihilation and τ\tau-decay experiments. In particular, at low energies the calculated bounds offer a more precise description of the modulus than the experimental data.Comment: 12 pages, 23 figures, prepared using EPJ style files; v2 corresponds to proofs version to appear in European Physical Journal C; extended discussion compared to v

    Covalent Modification of Lipids and Proteins in Rat Hepatocytes, and In Vitro, by Thioacetamide Metabolites

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Research in Toxicology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/tx3001658Thioacetamide (TA) is a well-known hepatotoxin in rats. Acute doses cause centrilobular necrosis and hyperbilirubinemia while chronic administration leads to biliary hyperplasia and cholangiocarcinoma. Its acute toxicity requires its oxidation to a stable S-oxide (TASO) that is oxidized further to a highly reactive S,S-dioxide (TASO2). To explore possible parallels between the metabolism, covalent binding and toxicity of TA and thiobenzamide (TB) we exposed freshly isolated rat hepatocytes to [14C]-TASO or [13C2D3]-TASO. TLC analysis of the cellular lipids showed a single major spot of radioactivity that mass spectral analysis showed to consist of N-acetimidoyl PE lipids having the same side chain composition as the PE fraction from untreated cells; no carbons or hydrogens from TASO were incorporated into the fatty acyl chains. Many cellular proteins contained N-acetyl- or N-acetimidoyl lysine residues in a 3:1 ratio (details to be reported separately). We also oxidized TASO with hydrogen peroxide in the presence of dipalmitoyl phosphatidylenthanolamine (DPPE) or lysozyme. Lysozyme was covalently modified at five of its six lysine side chains; only acetamide-type adducts were formed. DPPE in liposomes also gave only amide-type adducts, even when the reaction was carried out in tetrahydrofuran with only 10% water added. The exclusive formation of N-acetimidoyl PE in hepatocytes means that the concentration or activity of water must be extremely low in the region where TASO2 is formed, whereas at least some of the TASO2 can hydrolyze to acetylsulfinic acid before it reacts with cellular proteins. The requirement for two sequential oxidations to produce a reactive metabolite is unusual, but it is even more unusual that a reactive metabolite would react with water to form a new compound that retains a high degree of chemical reactivity toward biological nucleophiles. The possible contribution of lipid modification to the hepatotoxicity of TA/TASO remains to be determined
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