Application of Lobatto polynomials in atomic physics

The approximation properties of Lobatto polynomials are analyzed and then applied to approximate the atomic Kohn–Sham eigenfunction. In the first part of this article the approximation algorithm based on the Galerkin finite element method is derived. To obtain the approximation of the function, based on the presented algorithm, the linear set of equations must be solved. The matrix of the equation set is very sparse and its elements can be evaluated analytically. In the second part of this article, the algorithm is applied to evaluate adaptive polynomial approximation of selected Kohn–Sham eigenstates of indium (In) atom. The proposed r‐adaptive algorithm evaluates the minimum number of subintervals needed to represent the eigenfunction with required accuracy. Based on the r‐adaptive algorithm, the approximations of 4d, 5s 5p In eigenfunctions were calculated. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Dynamic behavior of cracked rotor subjected to multisine excitation

It is widely known that a developing shaft crack manifests itself in the appearance of nonlinear effects resulting in higher harmonics in a vibration spectrum. However, such symptoms are characteristic not only for developing shaft cracks but also for other malfunctions such as a shaft bow, a coupling misalignment, etc. That is why novel shaft crack detection methods introduce a specially designed diagnostic force applied to the shaft in order to amplify the particular symptoms of the crack. Most often a simple harmonic force is used for such purposes, yet the results may not be reliable.     

Investigation of the benefits of unsteady blowing actuation on a 2D wind turbine blade

This paper investigates the benefit of unsteady blowing actuation over a two-dimensional (2D) airfoil specially designed for wind turbine applications. The experiments were carried out in Syracuse University’s anechoic wind tunnel, both with and without large-scale unsteadiness in the free stream generated by a 2D cylinder upstream of the airfoil. By analyzing both surface pressure through wavelet analysis and Particle Image Velocimetry (PIV) velocity field measurements, we found a drastic change in the flow physics and the aerodynamic loading on the airfoil between steady and unsteady free-stream conditions. When there was no large-scale unsteadiness introduced in the flow, under open-loop flow control conditions with unsteady blowing, the leading-edge separation was delayed and the maximum lift coefficient was increased. For the cases where large-scale unsteadiness was introduced into the flow, the experiments showed that both open-loop and closed-loop control cases were capable of reducing load fluctuations by a measurable amount. However, only the closed-loop control case that utilized dynamic surface pressure information from the airfoil suction side near the leading edge was capable of consistently mitigating the fluctuating load.     

Novel family of fused tricyclic [1,4]diazepines: Design,synthesis, crystal structures and molecular docking studies

An efficient one-pot strategy for the synthesis of a new family of imidazo[1,4]diazepines has been developed and its mechanism has been proposed, which follows a seven-membered ring closure reaction. The condensation of 2- and 4-imidazolecarboxaldehyde with pyrazole amines provides six compounds 1–6, which are based on two types of fused tricyclic scaffolds. All presented compounds were fully spectroscopically characterized and their structure was unambiguously determined by single crystal X-ray crystallography. Molecular docking studies reveal a high similarity between binding modes of diazepines 1, 6 and eticlopride in the dopamine D₃ receptor, as well as between enantiomers 2S, 6S and nortriptyline in dopamine transporter DAT.     

Synthesis of Oligomers with Unsaturated End-Groups Based on Dianic Epoxy Resin and Crotonic Acid

Abstract

The synthesis of oligomers with unsaturated double end-bonds based on the reaction of dianic epoxy resin and crotonic acid was investigated. Experimental conditions included temperatures from 353–383 K and reaction times from 3.5–4.0h in the presence of quaternary ammonium salts dissolved in various organic solvents. The main kinetic parameters of the reaction were determined.     

Noether's theorem on time scales

We show that for any variational symmetry of the problem of the calculus of variations on time scales there exists a conserved quantity along the respective Euler-Lagrange extremals.     

In Memoriam Jaime Keller (1936–2011)

Jaime Keller passed away on January 7, 2011. He was the founder of Advances in Applied Clifford Algebras and its Editor-in-Chief since 1991. We recall the pre-history of AACA.     

Pharmacokinetic study of amoxicillin in human plasma by solid‐phase microextraction followed by high‐performance liquid chromatography–triple quadrupole mass spectrometry

Sensitive and selective analytical procedures based on high‐performance liquid chromatography with mass spectrometric detection were developed for the determination of amoxicillin in human plasma samples. Samples were prepared by applying in‐house manufactured molecularly imprinted solid‐phase microextraction probes. The detection of target compounds was performed in multiple reaction monitoring mode. The multiple reaction monitoring detection was operated in the positive electrospray ionization mode using the transitions of m/z 366 ([M + H]⁺) → 349 for amoxicillin and m/z 390 ([M + H]⁺) → 372 for gemifloxacin. The method was validated with precision within 15% relative standard deviation and accuracy within 15% relative error. The method was successfully applied to study of the pharmacokinetics of amoxicillin in human plasma after oral administration of amoxicillin. Copyright © 2013 John Wiley & Sons, Ltd.