Synthesis, characterization and performance of polystyrene/PMMA blend membranes for potential water treatment

© 2017 Elsevier B.V. PS membranes were prepared from polymeric blends of PS and PMMA via a phase inversion induced by an immersion precipitation in water coagulation baths. The effects of the casting parameters (e.g., solvent selection, the composition of the coagulation bath) and the type of polystyrene (substituents at the aromatic ring, tacticity) on the morphology and water permeation flux were studied. The findings reveal that modified PS promoting instantaneous demixing with NMP/water systems result in membranes wit- h macrovoids while the addition of 2% of PS-r-PMMA results in membranes with high water fluxes. The membranes morphologies were governed by a trade-off between thermodynamic and kinetic aspects. The antibacterial effect of (aPS)70-co-aPS(I)30/PMMA-based membrane was examined using static and cross-flow systems. These results illustrate the diversity in the design of these PS/PMMA based membranes and highlight the possibility to control the polymer chemistry for tailoring specific morphology, permeation, and antibacterial properties for the desired function

Fast Primal-Dual Gradient Method for Strongly Convex Minimization Problems with Linear Constraints

In this paper we consider a class of optimization problems with a strongly convex objective function and the feasible set given by an intersection of a simple convex set with a set given by a number of linear equality and inequality constraints. A number of optimization problems in applications can be stated in this form, examples being the entropy-linear programming, the ridge regression, the elastic net, the regularized optimal transport, etc. We extend the Fast Gradient Method applied to the dual problem in order to make it primal-dual so that it allows not only to solve the dual problem, but also to construct nearly optimal and nearly feasible solution of the primal problem. We also prove a theorem about the convergence rate for the proposed algorithm in terms of the objective function and the linear constraints infeasibility.Comment: Submitted for DOOR 201

Final State Interactions Effects in Neutrino-Nucleus Interactions

Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $\pi^0$ production data in $\sim 1$ GeV neutrino flux experiments is demonstrated.Comment: 13 pages, 16 figure

Magnetic-film atom chip with 10 μ\mum period lattices of microtraps for quantum information science with Rydberg atoms

We describe the fabrication and construction of a setup for creating lattices of magnetic microtraps for ultracold atoms on an atom chip. The lattice is defined by lithographic patterning of a permanent magnetic film. Patterned magnetic-film atom chips enable a large variety of trapping geometries over a wide range of length scales. We demonstrate an atom chip with a lattice constant of 10 $\mu$m, suitable for experiments in quantum information science employing the interaction between atoms in highly-excited Rydberg energy levels. The active trapping region contains lattice regions with square and hexagonal symmetry, with the two regions joined at an interface. A structure of macroscopic wires, cut out of a silver foil, was mounted under the atom chip in order to load ultracold $^{87}$Rb atoms into the microtraps. We demonstrate loading of atoms into the square and hexagonal lattice sections simultaneously and show resolved imaging of individual lattice sites. Magnetic-film lattices on atom chips provide a versatile platform for experiments with ultracold atoms, in particular for quantum information science and quantum simulation.Comment: 7 pages, 7 figure

Weighted pooling—practical and cost-effective techniques for pooled high-throughput sequencing

Motivation: Despite the rapid decline in sequencing costs, sequencing large cohorts of individuals is still prohibitively expensive. Recently, several sophisticated pooling designs were suggested that can identify carriers of rare alleles in large cohorts with a significantly smaller number of pools, thus dramatically reducing the cost of such large-scale sequencing projects. These approaches use combinatorial pooling designs where each individual is either present or absent from a pool. One can then infer the number of carriers in a pool, and by combining information across pools, reconstruct the identity of the carriers

Semiring and semimodule issues in MV-algebras

In this paper we propose a semiring-theoretic approach to MV-algebras based on the connection between such algebras and idempotent semirings - such an approach naturally imposing the introduction and study of a suitable corresponding class of semimodules, called MV-semimodules. We present several results addressed toward a semiring theory for MV-algebras. In particular we show a representation of MV-algebras as a subsemiring of the endomorphism semiring of a semilattice, the construction of the Grothendieck group of a semiring and its functorial nature, and the effect of Mundici categorical equivalence between MV-algebras and lattice-ordered Abelian groups with a distinguished strong order unit upon the relationship between MV-semimodules and semimodules over idempotent semifields.Comment: This version contains some corrections to some results at the end of Section

Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≥ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters

Post-Socialist Self-Censorship:Russia, Hungary and Latvia

This article argues that today in Central and Eastern Europe self-censorship, journalistic freedom and autonomy are just as severely affected by economic constraints, oligarchic influences and new authoritarianism as they are by their Communist pasts. Either way, journalists know exactly what to report, what to omit and how to advance their careers. This is reminiscent of adekvatnost’; a distinct strategy employed by Russian journalists, who regard this skill as an expression of professionalism. It implies having a ‘feel for the game’ and the ‘right instinct’, which allows them to enjoy a certain level of freedom in their work and express their creativity. The authors’ interviews with Latvian and Hungarian journalists, editors and producers examined the extent to which adekvatnost’ might be a feature of journalism beyond Russia, in particular when a media system faces rising populism and authoritarianism, paired with oligarch-dominated ownership. As such, knowledge gained about journalistic practices in the countries under investigation might also be useful in understanding media development beyond the post-Communist space, including Western Europe