Modified N–P Interpolation Theory for Closed Loop Pole Placement

Khargonekar and Tannenbaum have shown how to modify the Nevanlinna‐Pick (N–P) interpolation theory to design an internally stable and robust controller. In this paper, we present a new modification of the N‐P theory so that closed‐loop poles can be placed inside a circular region in the left half of the complex plane, in addition to the control system design being robust and internally stable. This ensures a minimum damping of the closed‐loop system. Numerical examples illustrate the theory.     

Synthesis and characterization of D-2PA-Pd(II)@SBA-15 catalyst via “click chemistry”: highly active catalyst for Suzuki coupling reactions

Copper catalysed cycloaddition reaction between azide and terminal alkyne, called as “click reaction”, was found to be modular approach for the synthesis of facile, highly efficient and recoverable D-2PA-Pd(II)@SBA-15 catalyst. In efforts to synthesize the catalyst, the cycloaddition reaction between azido-functionalized mesoporous SBA-15 and N,N-dimethyl-2-propynylamine (D-2PA) has been carried out, followed by the complexation with PdCl₂. To analyze physiochemical properties of synthesized materials, various characterization techniques such as CHN elemental analysis, X-ray diffraction, solid state ¹³C and ²⁹Si NMR spectra, FT-IR, XPS, SEM, TEM and N₂ sorption analysis, TGA and DTA, UV–Vis spectroscopy have been carried out. The synthesized catalyst, D-2PA-Pd(II)@SBA-15, exhibited excellent catalytic activities with good product yield and high TON towards Suzuki coupling reaction of various aryl halides with phenylboronic acid. The effect of solvent, base and temperature on coupling reactions has also been described. The developed protocol offers recyclability of catalyst for multiple (four) times without any appreciable loss in stability and catalytic reactivity.     

Copolymerization of γ-methacryloxy propyl trimethoxy silane and methyl methacrylate

Copolymerization of methyl methacrylate (MMA) with low mole fractions of γ-methacryloxypropyl trimethoxy silane (MTS) was investigated with an aim to synthesize copolymers which can be cross-linked by hydrolytic cleavage of methoxy groups. Several copolymer samples were prepared by changing the molar ratios of two monomers in the initial monomer feed. Rate of copolymerization depended on the concentration of monomers and increased with an increase in MTS concentration. The copolymers were characterized by infrared (IR) and ¹H nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, and intrinsic viscosity determination. The effect of structure on thermal behavior was investigated by using dynamic thermogravimetry in nitrogen atmosphere. An attempt was made to identify products of degradation using mass spectrometry. Copolymers were also hydrolyzed in water and cross-linked. The effect of MTS in copolymers on percentage gel formation was determined.     

Categorizing facial expressions: a comparison of computational models

Recognizing expressions is a key part of human social interaction, and processing of facial expression information is largely automatic for humans, but it is a non-trivial task for a computational system. The purpose of this work is to develop computational models capable of differentiating between a range of human facial expressions. Raw face images are examples of high-dimensional data, so here we use two dimensionality reduction techniques: principal component analysis and curvilinear component analysis. We also preprocess the images with a bank of Gabor filters, so that important features in the face images may be identified. Subsequently, the faces are classified using a support vector machine. We show that it is possible to differentiate faces with a prototypical expression from the neutral expression. Moreover, we can achieve this with data that has been massively reduced in size: in the best case the original images are reduced to just 5 components. We also investigate the effect size on face images, a concept which has not been reported previously on faces. This enables us to identify those areas of the face that are involved in the production of a facial expression.     

Depth-dependent anisotropies of amides and sugar in perpendicular and parallel sections of articular cartilage by Fourier transform infrared imaging

Full thickness blocks of canine humeral cartilage were microtomed into both perpendicular sections and a series of 100 parallel sections, each 6 μm thick. Fourier transform infrared (IR) imaging was used to image each tissue section eleven times under different IR polarizations (from 0° to 180° polarization states in 20° increments and with an additional 90° polarization), at a spatial resolution of 6.25 μm and a wavenumber step of 8 cm^?1. With increasing depth from the articular surface, amide anisotropies increased in the perpendicular sections and decreased in the parallel sections. Both types of tissue sectioning identified a 90° difference between amide I and amide II in the superficial zone (SZ) of cartilage. The fibrillar distribution in the parallel sections from the SZ was shown to not be random. Sugar had a weak but recognizable anisotropy in the upper part of the radial zone (RZ) in the perpendicular sections. The depth‐dependent anisotropic data were fitted with a theoretical equation that contained three signature parameters, which illustrate the arcade structure of collagens with the aid of a fibril model. Fourier‐transform IR imaging of both perpendicular and parallel sections provides the possibility of determining the three‐dimensional macromolecular structures in articular cartilage. Being sensitive to the orientation of the macromolecular structure in healthy articular cartilage aids the prospect of detecting the early onset of the tissue degradation that may lead to pathological conditions such as osteoarthritis. Microsc. Res. Tech. 74:122–132, 2011. © 2010 Wiley‐Liss, Inc.     

Solubility Properties of Chlorhexidine Salts

Chlorhexidine (CHX) is effective in treating oral bacterial infections. The solubility was shown to be highly dependent on the salt present in solution. Gluconate enhances the amount of CHX diacetate in solution possibly through mixed micelles formation, because the solubility product is such that the concentration of CHX will exceed the critical micelle concentration. However, only low concentrations of CHX dichloride can be obtained, which is not appreciably solubilized by gluconate ions. The low concentration of CHX that can be achieved in physiological concentrations of chloride in the oral cavity may be problematic for dental, slow release formulations.     

Lipid Profiling Reveals Tissue-Specific Differences for Ethanolamide Lipids in Mice Lacking Fatty Acid Amide Hydrolase

N-Acylethanolamines (NAE) are fatty acid derivatives, some of which function as endocannabinoids in mammals. NAE metabolism involves common (phosphatidylethanolamines, PEs) and uncommon (N-acylphosphatidylethanolamines, NAPEs) membrane phospholipids. Here we have identified and quantified more than a hundred metabolites in the NAE/endocannabinoid pathway in mouse brain and heart tissues, including many previously unreported molecular species of NAPE. We found that brain tissue of mice lacking fatty acid amide hydrolase (FAAH ^−/−) had elevated PE and NAPE molecular species in addition to elevated NAEs, suggesting that FAAH activity participates in the overall regulation of this pathway. This perturbation of the NAE pathway in brain was not observed in heart tissue of FAAH ^−/− mice, indicating that metabolic regulation of the NAE pathway differs in these two organs and the metabolic enzymes that catabolize NAEs are most likely differentially distributed and/or regulated. Targeted lipidomics analysis, like that presented here, will continue to provide important insights into cellular lipid signaling networks.     

Mild Solution and Constrained Local Controllability of Semilinear Boundary Control Systems

The existence of mild solution and the constrained local controllability of a retarded boundary control system with nonlocal delay condition have been established. The theory of extrapolation spaces is applied to derive the mild solution. Then, the constrained local controllability is established using the generalized open mapping theorem. In the last section, application of the result is shown through examples of control systems represented by hyperbolic partial differential equations.