The effect of back electrode on the formation of electrodeposited CoNiFe magnetic nanotubes and nanowires

The electrodeposition of cobalt + nickel + iron alloy nanostructures in aqueous sulfate solution has been studied using vitreous templates placed on highly ordered porous anodic alumina oxide (AAO). During the deposition process some electrochemical bath parameters such as ion content, deposition voltage, pH and temperature of solution were kept constant. The morphological properties of the nanostructures were studied by scanning electron microscopy (SEM) and the chemical composition was determined by examination of the energy dispersive X-ray (EDX) spectra. The magnetic behaviour of the arrays was determined with a vibrating sample magnetometer (VSM). Voltammetric and galvanostatic results indicate that the back electrodes placed on AAO plays the main role in obtaining nanowire or nanotube structured material.     

Force constant calculations for octahedral complexes of the type M(CO)5L, based on the CO-factored force field

Using the maximum value of the sum of the interaction constants, the CO-factored force field of octahedral M(CO)₅L molecules was solved to give the relations which allow direct calculation of force constants from C---O stretching frequencies of the all-¹²C¹⁶O molecule. The force constants calculated by these relations were used to predict C---O stretching frequencies of isotopically enriched species of some complexes of the type M(CO)₅L. The results obtained showed that there exists a very good agreement between observed and calculated frequencies. This led us to conclude that the solution presented for the force field of M(CO)₅L molecules is a valid solution.     

Selective determination of total normal microcystin by colorimetry, LC/UV detection and/or LC/MS

Microcystins, hepatotoxic cyclic heptapeptides, are produced by freshwater cyanobacteria, and are classified four groups according to the amino acid structure at unit 7. Normal microcystins contain N-methyldehydroalanine (Mdha) or dehydroalanine (Dha) at unit 7, and command the great part of all microcystins. As unusual microcystin classes, [Dhb⁷]microcystins, [ - and -Ala⁷, or N-MeAla⁷]microcystins and [ -Ser⁷]microcystins have been found.

On tumor initiation and/or promotion activities of microcystins, the tumor promotion activity of normal microcystins has been found, but cancer-related activities of microcystins belonging in the other classes have not been clear.

To determine normal microcystins as hepatotoxic tumor promoters, a selective determination method was developed. Only Mdha or Dha in normal microcystins was reacted with glutathione (GSH). The GSH-normal microcystins conjugates were reacted with trinitrobenzene sulfonate (TNBS). The TNB–GSH-normal microcystin conjugate can be determined as the total normal microcystin by colorimetry. After methanolysis of the conjugate, dimethyl TNB–glutamate from the conjugate was determined by liquid chromatography/ultraviolet detection (LC/UV) and/or liquid chromatography/mass spectrometry (LC/MS). The detection limits of the total normal microcystin by colorimetry, LC/UV and/or LC/MS were 1 μg, 10 and 0.1 ng, respectively.     

Impacts of uniaxial elongation on the bandstructures of two-dimensional sonic crystals and associated applications

Influences of uniaxial elongation along the [11] direction of triangular and [10] direction of square sonic crystals under the constraint of conserved unit cell area are investigated by examining band structures and equi-frequency contours. Lowest-lying band gap of the triangular lattice observed at high filling fractions diminishes for negative elongation (compression), whereas another band gap develops at lower frequencies whose width reaches appreciable values for moderate elongation. The band gap of the square lattice, which appears at high filling fractions, is modified slightly with elongation. Frequency ranges of the bands, and thus the group velocities along the high-symmetry directions, vary with elongation which may be useful in applications like slow sound propagation. Elongation is observed to modify the equi-frequency contours significantly through reducing the lattice symmetry. The most prominent impact is the transformation of closed contours into open ones, whereas the rest are stretched either along or normal to the elongation axis of the 1st Brillouin Zone. This observation is utilized to implement wide-band all-angle self-collimation and superprism effect, which are demonstrated through Finite-Element computations.     

“Synthesis and properties of N′-hydroxy-2-(hydroxyimino)-N-(4-{[(2-hydroxyphenyl)-methylene]amino}-1-naphthyl)ethanimidamide and its metal complexes”

Russian Journal of Organic Chemistry -     

Syntheses and characterization of poly(iminophenol)s derived from 4-bromobenzaldehyde: Thermal, optical, electrochemical and fluorescent properties

Schiff base monomers[2-（4-bromobenzylideneamino）phenol and 2-（4-bromobenzylideneamino）-5-methylphenol] were synthesized by the condensation reaction of 4-bromobenzaldehyde with aromatic aminophenols.Then,the monomers were converted to their polyphenol derivatives by oxidative polycondensation reactions（OP） in an aqueous alkaline medium. The structures of the synthesized compounds were characterized by solubility tests,FT-IR,NMR,TG-DTA,DSC and SEC techniques.The HOMO-LUMO energy levels and electrochemical（E_g ） and optical（E_g） band gaps were calculated from cyclic voltammetry（CV） and UV-Vis measurements,respectively.Cyclic voltammetry（CV） was used to determine the electrochemical oxidation-reduction characteristics.Optical properties were investigated by UV-Vis and fluorescence analyses.Solid state electrical conductivities were measured on polymer films by four point probe technique using a Keifhley 2400 electrometer.The effects of electron-donating（-CH₃） group at p-position of -NH₂ group in aminophenol on electrochemical and thermal properties were also discussed.Photoluminescence（PL） properties of the synthesized materials were determined in solution forms using different solvents.Fluorescence measurements were carried out in various concentrated solutions to determine the optimum concentrations to obtain the maximal PL intensities.     

An adaptive large neighborhood search algorithm for a selective and periodic inventory routing problem

We study a selective and periodic inventory routing problem (SPIRP) and develop an Adaptive Large Neighborhood Search (ALNS) algorithm for its solution. The problem concerns a biodiesel production facility collecting used vegetable oil from sources, such as restaurants, catering companies and hotels that produce waste vegetable oil in considerable amounts. The facility reuses the collected waste oil as raw material to produce biodiesel. It has to meet certain raw material requirements either from daily collection, or from its inventory, or by purchasing virgin oil. SPIRP involves decisions about which of the present source nodes to include in the collection program, and which periodic (weekly) routing schedule to repeat over an infinite planning horizon. The objective is to minimize the total collection, inventory and purchasing costs while meeting the raw material requirements and operational constraints. A single-commodity flow-based mixed integer linear programming (MILP) model was proposed for this problem in an earlier study. The model was solved with 25 source nodes on a 7-day cyclic planning horizon. In order to tackle larger instances, we develop an ALNS algorithm that is based on a rich neighborhood structure with 11 distinct moves tailored to this problem. We demonstrate the performance of the ALNS, and compare it with the MILP model on test instances containing up to 100 source nodes.     

Interior Epigraph Directions method for nonsmooth and nonconvex optimization via generalized augmented Lagrangian duality

We propose and study a new method, called the Interior Epigraph Directions (IED) method, for solving constrained nonsmooth and nonconvex optimization. The IED method considers the dual problem induced by a generalized augmented Lagrangian duality scheme, and obtains the primal solution by generating a sequence of iterates in the interior of the dual epigraph. First, a deflected subgradient (DSG) direction is used to generate a linear approximation to the dual problem. Second, this linear approximation is solved using a Newton-like step. This Newton-like step is inspired by the Nonsmooth Feasible Directions Algorithm (NFDA), recently proposed by Freire and co-workers for solving unconstrained, nonsmooth convex problems. We have modified the NFDA so that it takes advantage of the special structure of the epigraph of the dual function. We prove that all the accumulation points of the primal sequence generated by the IED method are solutions of the original problem. We carry out numerical experiments by using test problems from the literature. In particular, we study several instances of the Kissing Number Problem, previously solved by various approaches such as an augmented penalty method, the DSG method, as well as several popular differentiable solvers. Our experiments show that the quality of the solutions obtained by the IED method is comparable with (and sometimes favourable over) those obtained by the differentiable solvers.     

A numerical method for nonconvex multi-objective optimal control problems

A numerical method is proposed for constructing an approximation of the Pareto front of nonconvex multi-objective optimal control problems. First, a suitable scalarization technique is employed for the multi-objective optimal control problem. Then by using a grid of scalarization parameter values, i.e., a grid of weights, a sequence of single-objective optimal control problems are solved to obtain points which are spread over the Pareto front. The technique is illustrated on problems involving tumor anti-angiogenesis and a fed-batch bioreactor, which exhibit bang–bang, singular and boundary types of optimal control. We illustrate that the Bolza form, the traditional scalarization in optimal control, fails to represent all the compromise, i.e., Pareto optimal, solutions.