On Affine Normal Forms and a Classification of Homogeneous Surfaces in Affine Three-Space

We classify homogeneous surfaces in real and complex affine three-space. This is achieved by choosing affine coordinates so that the surface is defined by a function whose Taylor series is in a preferred normal form.     

Dynamics of surface reactions: from “hot” precursors to conventional thermal activation

Heterogeneous catalytic reactions usually contain steps, e.g., adsorption, generating energy-rich (“hot”) precursors for other steps. With increasing the rate of energy relaxation one can observe a transition from the reaction regime dominated by “hot” precursors to conventional thermal activation. To illustrate this transition in detail and to show what may happen in various situations, I present an analytical model based on the Fokker-Planck equation for energy relaxation.     

Synaptic Coupling Between Two Electronic Neurons

An electrical circuit is proposed to realize an unidirectional coupling between two cells, mimicking chemical synaptic coupling. Each cell represents the FitzHugh–Nagumo (FHN) model of neuron with a modified exitability (MFHN). We present experimental results on frequency doublings and on the chaotic dynamics depending on the coupling strength in a master–slave configuration. In all experiments, we stress the influence of the coupling strength on the control of the slave neuron.     

Extracting metabolite ions out of a matrix background by combined mass defect,neutral loss and isotope filtration

Mass defect, neutral loss and isotope filtration techniques were applied to electrospray ionization mass spectrometry (ESI‐MS) data obtained for in vivo and in vitro samples of drug metabolism studies. A combination of these post‐acquisition processing techniques was shown to be more powerful than the use of one of these tools alone for the detection in complex matrices of metabolites of candidate drugs with a characteristic isotope pattern (e.g. containing bromine, chlorine, or a high proportion of radiolabeled drug (¹²C/¹⁴C)) or characteristic neutral losses. In combination with ‘all‐in‐one’ data acquisition this methodology is able to perform software‐driven constant neutral loss scanning for an unlimited number of mass differences at any time after analysis. Highly selective MS chromatograms were obtained with excellent correlation with their corresponding radiochromatograms. Copyright © 2009 John Wiley & Sons, Ltd.     

Quasi-contraction on a cone metric space

In this work we define and study quasi-contraction on a cone metric space. For such a mapping we prove a fixed point theorem. Among other things, we generalize a recent result of H. L. Guang and Z. Xian, and the main result of ?iri? is also recovered.     

NMR investigation of chlorophosphorylation products of N‐vinylazoles

The structure of novel phosphorus‐containing N‐vinylazoles prepared by action of phosphorus pentachloride has been studied by multinuclear ¹H, ¹³C, ¹⁵N, ³¹P and two‐dimensional (2D) NMR spectroscopy. N‐vinyl‐substituted 1,2‐diazoles and 1,2,3‐triazoles have undergone phosphorylation, exclusively, on double bond. N‐vinylazoles‐based hexa‐coordinated phosphorus compounds have been synthesized for the first time. ³¹P NMR spectroscopy provides the most convenient and unambiguous method for the investigation of E—Z‐isomeric structures of phosphorylated enamines. Copyright © 2008 John Wiley & Sons, Ltd.     

Calibration and use of a MEMS surface fence for wall shear stress measurements in turbulent flows

Microelectromechanical systems (MEMS) sensors are increasingly used for measurements in fluid dynamics since, because of their inherently compact size, they allow access to the information that was previously unavailable. In this paper we describe further testing of a MEMS sensor used to measure surface shear stress. It is a wall-mounted fence that bends under the influence of the pressure difference resulting from the velocity shear at the wall. The fences have been successfully calibrated in a wind tunnel and, as an example of their application, used to determine mean and fluctuating shear stress (along with spectra) in a cylindrical cavity flow.