Synthesis of Nanocomposite Adsorbent on the Base of Polypropylene Fabric with Copper Ferrocyanide Grains

Composite adsorbents based on polypropylene fibers with chemically bound nanopartices of copper fer-rocyanide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto non-woven polypropylene fabric followed by in-situ formation of copper ferrocyanize nanoparticles and their stabilization on the fabric surface within the grafted layer. Scanning electron microscope investiga-tions revealed a homogeneous compact layer of copper ferrocynide nanosized aggregates (65-70 nm). The synthesized composite material was stable in the base solutions (pH 10.5) and exhibited high efficiency for cesium adsorption. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545

Synthesis of Polypropylene Fiber / Hydrated Iron Oxide Nanocomposite Adsorbent

Composite adsorbent based on the polypropylene fibers with chemically bound nanoparticles of hydrated iron (III) oxide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto the surface of polypropylene fibers followed by the in-situ formation of hydrated iron oxide nanoparticles and their stabilization on the fibers‟ surface within the grafted layer. SEM and XRD investigations revealed a compact homogeneous layer of amorphous nanoaggregates (70-100 nm) formed by iron hydroxide on the fibers‟ surface. The synthesized nanocomposite fibers were stable in the aggressive medium for a long time and exhibited good adsorption properties for uranyl ions. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3558

Production of Sorption Active Polypropylene Fabrics with Sulfonic Acid Groups by Radiation-Induced Modification of Polymer Surface

Sorption active material carrying sulfonic acid groups was synthesized by radiation-induced graft polymerization of styrene monomer onto the surface of non-woven polypropylene fabric followed by sulfonation of grafted polystyrene chains. The effect of the main experimental parameters on styrene grafting degree (absorbed dose, monomer concentration, reaction time) was investigated. It was found that sulfonation degree of the grafted polystyrene chains with 5% chlorosulfonic acid at room temperature depends on the reaction time and reaches 80% for the samples with a medium value of styrene grafting degree. Sorption active polypropylene fabrics with sulfonic acid group densities of 3.5–5 meq/g were obtained.Радіаційно-індукована прищеплювальна полімеризація стиролу на неткану поліпропіленову тканину з подальшим сульфуванням прищеплених ланцюгів полістиролу була використана для синтезу сорбційно-активного матеріалу. Проведено дослідження впливу основних експериментальних параметрів (поглинена доза, концентрація мономера, час реакції) на ступінь прищеплювальної полімеризації стиролу. Встановлено, що ефективність сульфування прищеплених ланцюгів полістиролу при кімнатній температурі в 5% розчині хлорсульфонової кислоти залежить від часу реакції і для зразків з середніми ступенями прищеплення досягає 80%. Були синтезовані сорбційно-активні поліпропіленові тканини з щільністю кислотних груп 3,5–5 мг-екв/г.Радиационно-индуцированная прививочная полимеризация стирола на нетканной полипропиленовой материи с последующим сульфированием привитых цепей полистирола была использована для синтеза сорбционно-активного материала. Проведено исследование влияния основных экспериментальных параметров (поглощенная доза, концентрация мономера, время реакции) на степень прививочной полимеризации стирола. Установлено, что эффективность сульфирования привитых цепей полистирола при комнатной температуре в 5% растворе хлорсульфоновой кислоты зависит от времени реакции и для образцов со средними степенями прививки достигает 80%. Были синтезированы сорбционно-активные полипропиленовые ткани с плотностью кислотных групп 3,5–5 мг-экв/г

Coupled superconducting qudit-resonator system: Energy spectrum, state population, and state transition under microwave drive

Superconducting quantum multilevel systems coupled to resonators have recently been considered in some applications such as microwave lasing and high-fidelity quantum logical gates. In this work, using an rf-SQUID type phase qudit coupled to a microwave coplanar waveguide resonator, we study both theoretically and experimentally the energy spectrum of the system when the qudit level spacings are varied around the resonator frequency by changing the magnetic flux applied to the qudit loop. We show that the experimental result can be well described by a theoretical model that extends from the usual two-level Jaynes-Cummings system to the present four-level system. It is also shown that due to the small anharmonicity of the phase device a simplified model capturing the leading state interactions fits the experimental spectra very well. Furthermore we use the Lindblad master equation containing various relaxation and dephasing processes to calculate the level populations in the simpler qutrit-resonator system, which allows a clear understanding of the dynamics of the system under the microwave drive. Our results help to better understand and perform the experiments of coupled multilevel and resonator systems and can be applied in the case of transmon or Xmon qudits having similar anharmonicity to the present phase device.This work was supported by the Ministry of Science and Technology of China (Grants No. 2014CB921202, No. 2015CB921104, and No. 2016YFA0300601),the National Natural Science Foundation of China (Grants No. 91321208 and No. 11674380)the Key Research Program of the Chinese Academy of Sciences (Grant No. XDPB08-3)S.H. acknowledges support by the US NSF (PHY-1314861)

Biophysical and enzymatic properties of aminoglycoside adenylyltransferase AadA6 from Pseudomonas aeruginosa

AbstractThe gene coding for the aminoglycoside adenylyltransferase (aadA6) from a clinical isolate of Pseudomonas aeruginosa was cloned and expressed in Escherichia coli strain BL21(DE3)pLysS. The overexpressed enzyme (AadA6, 281 amino-acid residues) and a carboxy-terminal truncated variant molecule ([1-264]AadA6) were purified to near homogeneity and characterized. Light scattering experiments conducted under low ionic strength supported equilibrium between monomeric and homodimeric arrangements of the enzyme subunits. Circular Dichroism spectropolarimetry indicated a close structural relation to adenylate kinases. Both forms modified covalently the aminoglycosides streptomycin and spectinomycin. The enzyme required at least 5mM MgCl2 for normal Michaelis–Menten kinetics. Streptomycin exhibited a strong substrate inhibition effect at 1mM MgCl2. The truncated 17 residues at the C-terminus have little influence on protein folding, whereas they have a positive effect on the enzymic activity and stabilize dimers at high protein concentrations (>100μM). Homology modelling and docking based on known crystal structures yielded models of the central ternary complex of monomeric AadA6 with ATP and streptomycin or spectinomycin

An origin for small neutrino masses in the NMSSM

We consider the Next to Minimal Supersymmetric Standard Model (NMSSM) which provides a natural solution to the so-called mu problem by introducing a new gauge-singlet superfield S. We realize that a new mechanism of neutrino mass suppression, based on the R-parity violating bilinear terms mu_i L_i H_u mixing neutrinos and higgsinos, arises within the NMSSM, offering thus an original solution to the neutrino mass problem (connected to the solution for the mu problem). We generate realistic (Majorana) neutrino mass values without requiring any strong hierarchy amongst the fundamental parameters, in contrast with the alternative models. In particular, the ratio |mu_i/mu| can reach about 10^-1, unlike in the MSSM where it has to be much smaller than unity. We check that the obtained parameters also satisfy the collider constraints and internal consistencies of the NMSSM. The price to pay for this new cancellation-type mechanism of neutrino mass reduction is a certain fine tuning, which get significantly improved in some regions of parameter space. Besides, we discuss the feasibility of our scenario when the R-parity violating bilinear terms have a common origin with the mu term, namely when those are generated via a VEV of the S scalar component from the couplings lambda_i S L_i H_u. Finally, we make comments on some specific phenomenology of the NMSSM in the presence of R-parity violating bilinear terms.Comment: 21 pages, 5 figures, Latex fil

W^+W^+ plus dijet production in the POWHEGBOX

We present an implementation of the calculation of the production of W^+W^+ plus two jets at hadron colliders, at next-to-leading order (NLO) in QCD, in the POWHEG framework, which is a method that allows the interfacing of NLO calculations to shower Monte Carlo programs. This is the first 2 -> 4 process to be described to NLO accuracy within a shower Monte Carlo framework. The implementation was built within the POWHEGBOX package. We discuss a few technical improvements that were needed in the POWHEGBOX to deal with the computer intensive nature of the NLO calculation, and argue that further improvements are possible, so that the method can match the complexity that is reached today in NLO calculations. We have interfaced our POWHEG implementation with PYTHIA and HERWIG, and present some phenomenological results, discussing similarities and differences between the pure NLO and the POWHEG+PYTHIA calculation both for inclusive and more exclusive distributions. We have made the relevant code available at the POWHEGBOX web site.Comment: 16 pages, 5 figure

Energy Spectrum of Bloch Electrons Under Checkerboard Field Modulations

Two-dimensional Bloch electrons in a uniform magnetic field exhibit complex energy spectrum. When static electric and magnetic modulations with a checkerboard pattern are superimposed on the uniform magnetic field, more structures and symmetries of the spectra are found, due to the additional adjustable parameters from the modulations. We give a comprehensive report on these new symmetries. We have also found an electric-modulation induced energy gap, whose magnitude is independent of the strength of either the uniform or the modulated magnetic field. This study is applicable to experimentally accessible systems and is related to the investigations on frustrated antiferromagnetism.Comment: 8 pages, 6 figures (reduced in sizes), submitted to Phys. Rev.

Randomised comparison of initial triple DMARD therapy with methotrexate monotherapy in combination with low-dose glucocorticoid bridging therapy; 1-year data of the tREACH trial

Objectives To compare 1-year clinical efficacy of (1) initial triple disease-modifying antirheumatic drug therapy (iTDT) with initial methotrexate (MTX) monotherapy (iMM) and (2) different glucocorticoid (GC) bridging therapies: oral versus a single intramuscular injection in early rheumatoid arthritis. Methods In a single-blinded randomised clinical trial patients were randomised into three arms: (A) iTDT (methotrexate+sulfasalazine+hydroxychloroquine) with GCs intramuscularly; (B) iTDT with an oral GC tapering scheme and (C) MTX with oral GCs similar to B. Primary outcomes were (1) area under the curve (AUC) of Health Assessment Questionnaire (HAQ) and Disease Activity Score (DAS) and (2) the proportion of patients with radiographic progression. Results 281 patients were randomly assigned to arms A (n=91), B (n=93) or C (n=97). The AUC DAS and HAQ were respectively -2.39 (95% CI -4.77 to -0.00) and -1.67 (95% CI -3.35 to 0.02) lower in patients receiving iTDT than in those receiving iMM. After 3 months, treatment failure occurred less often in the iTDT group, resulting in 40% fewer treatment intensifications. The difference in treatment intensifications between the arms required to maintain the predefined treatment goal remained over time. No differences were seen between the two GC bridging therapies. Respectively 21%, 24% and 23% of patients in arms A, B and C had radiographic progression after 1 year. Patients receiving iTDT had more adjustments of their medication owing to adverse events than those receiving iMM. Conclusions Treatment goals are attained more quickly and maintained with fewer treatment intensifications with iTDT than with iMM. However, no difference in radiographic progression is seen. Both GC bridging therapies are equally effective and, therefore, both can be used

Novel LiAlO2 Material for Scalable and Facile Lithium Recovery Using Electrochemical Ion Pumping

In this study, α-LiAlO2 was investigated for the first time as a Li-capturing positive electrode material to recover Li from aqueous Li resources. The material was synthesized using hydrothermal synthesis and air annealing, which is a low-cost and low-energy fabrication process. The physical characterization showed that the material formed an α-LiAlO2 phase, and electrochemical activation revealed the presence of AlO2* as a Li deficient form that can intercalate Li+. The AlO2*/activated carbon electrode pair showed selective capture of Li+ ions when the concentrations were between 100 mM and 25 mM. In mono salt solution comprising 25 mM LiCl, the adsorption capacity was 8.25 mg g−1, and the energy consumption was 27.98 Wh mol Li−1. The system can also handle complex solutions such as first-pass seawater reverse osmosis brine, which has a slightly higher concentration of Li than seawater at 0.34 ppm. © 2023 by the authors.This study is made possible by Qatar National Research Fund (QNRF) under National Priorities Research Program (NPRP) grant (#NPRP12S-0227-190166) and Graduate Student Research Award (GSRA) grant (#GSRA8-L-2-0411-21011).Scopu