Thiophenol derivatives as a reducing agent for in situ generation of Cu(I) species via electron transfer reaction in copper‐catalyzed living/controlled radical polymerization of styrene

The copper‐catalyzed living radical polymerization (LRP) of styrene (St) was carried out in the presence of thiophenol derivative such as sodium thiophenolate (PhSNa) or p‐methoxythiophenol as a reducing agent for Cu(II) by using either 1‐chloro‐1‐phenyl ethane or ethyl‐2‐bromoisobutyrate as an initiator and N,N,N′,N″,N″‐pentamethyldiethylenetriamine as ligand at 110 °C. Kinetic experiments were carried out to reveal the effect of PhSNa concentration on copper‐catalyzed LRP of St. This technique was successfully applied for the preparation of both chain‐extended polymer and block copolymer polystyrene‐b‐poly(methyl methacrylate). The obtained polymers were characterized using GPC, ¹H‐NMR, and MALDI‐TOF measurements. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5923–5932, 2006     

Low temperature CO induced growth of Pd supported on a monolayer silica film

Nucleation, growth and sintering of Pd deposited on an ultra-thin silica film were studied by scanning tunneling microscopy and infrared reflection absorption spectroscopy. No preferential nucleation of Pd on the silica surface was observed both at 90 and 300 K deposition. When adsorbed on Pd clusters formed at 90 K, CO causes a strong sintering effect even at this temperature. The results are rationalized on the basis of a high mobility of Pd carbonyl-like species on the silica film. At a given Pd coverage, the extent of CO induced sintering cannot be achieved by annealing in vacuum. In addition, vacuum sintering, which commences above 700 K, goes simultaneously with interdiffusion of Pd and support.     

Performance of Airyprime beam in turbulent atmosphere

Photonic Network Communications - In this paper, we present scintillation and bit error rate (BER) behavior of Airyprime beam in turbulent atmosphere. We use numerical setup random phase screen...     

Focusing with two-dimensional angular-symmetric circular acoustic lenses

Focusing properties of an acoustic lens based on a modified triangular sonic crystal slab whose columns are aligned on concentric arcs of equal radial distance are investigated. Capability of focusing normally-incident plane waves is demonstrated by means of Finite Element Method. Focusing mechanisms are discussed on the basis of band structures and equifrequency contours considering a model where triangular lattice is elongated along ΓK direction. Focusing behavior of the proposed lens is argued to arise from negative refractions at the air-lens interfaces accompanied by index guiding in its interiors. Wavelength-order confinement in the transverse direction is observed. Double focusing is attributed to geometrical effects and contribution of self guiding is discussed. Possibility of occurrence of birefraction at the input face of the lens together with positive refraction at the output face is also discussed.     

Parametric analysis of flare edge rolling throat bending and asymmetric flare effects for H-plane horn radiator

In this paper, radiation characteristics of H-plane sectoral horn antenna are treated systematically by investigation of main structural design parameters and, flare edge rolling, throat bending and asymmetric flare effects. The analytical regularization method (ARM) is used to solve the problem of E-polarized wave diffraction in a fast and accurate way. The numerical procedure is initially verified by the analytical solutions, and then the calculated directivity gain patterns are demonstrated for the modeled horn antenna configurations. Proper choices of the antenna parameters, such as horn depth, aperture length, feeder waveguide width, flare angle, wall thickness, flare edge rolling and throat bending are proposed for the designers to reach high directivity gain, narrow beam width, suppressed side lobe levels, increased front-to back ratio and improved aperture efficiency.     

Syntheses,characterizations and electrochromic applications of polymers derived from carbazole containing thiophene rings in side chain with electrochemical and FeCl3 methods

1,8-Bis(3,6-di(thiophen-3-yl)-9H-carbazol-9-yl)octane (BDTCO) was synthesized via Ullmann and Suzuki couplings. Additionally, its homopolymer and copolymers with 3,4-ethylenedioxythiophene (EDOT), pyrrole (Py) and thiophene (Th) were synthesized and coated onto an ITO–glass surface via electrochemical oxidative polymerization. The spectroelectrochemical and electrochromic properties of the polymers were also investigated. The switching ability of these polymers was measured as the percent transmittance (T%) at their point of maximum contrast. Moreover, the polymer of BDTCO (P-BDTCO) was successfully synthesized through FeCl₃ oxidative polymerization. The compounds were characterized by FT-IR, NMR and X-ray Photoelectron Spectroscopy (XPS), and their thermal stabilities were determined via TG measurements. The solid state conductivities of the polymeric films coated onto the ITO–glass surface were measured via the four point probe technique using an electrometer. In addition, the surface morphological properties were investigated by Scanning Electron Microscopy (SEM) for different magnifications.     

Recent biopharmaceutical applications of capillary electrophoresis methods on recombinant DNA technology-based products

Biopharmaceuticals (recombinant technology-based products, vaccines, whole blood and blood components, gene therapy, cells, tissues, etc.,) are described as biological medical products produced from various living sources such as human, microbial, animal, and so on by manufacturing, extraction, or semi-synthesis. They are complex molecules having high molecular weights. For their safety and efficacy, their structural, clinical, physicochemical, and chemical features must be carefully controlled, and they must be well characterized by analytical techniques before the approval of the final product. Capillary electrophoresis (CE) having versatile modes can provide valuable safety and efficacy information, such as amino acid sequence, size variants (low and high molecular weight variants), charged variants (acidic and basic impurities), aggregates, N-linked glycosylation, and O-linked glycosylation. There are numerous applications of CE in the literature. In this review, the most significant and recent studies on the analysis of recombinant DNA technology-based products using different CE modes in the last ten years have been overviewed. It was seen that the researches mostly focus on the analysis of mAbs and IgG. In addition, in recent years, researchers have started to prefer CE combined mass spectrometry (MS) techniques to provide a more detailed characterization for protein and peptide fragments.     

Simultaneous reconstruction of the source term and the surface heat transfer coefficient

We study the problem of identifying unknown source terms in an inverse parabolic problem, when the overspecified (measured) data are given in form of Dirichlet boundary condition u(0,t) = h(t) and , where is an arbitrarily prescribed subregion. The main goal here is to show that the gradient of cost functional can be expressed via the solutions of the direct and corresponding adjoint problems. We prove Hölder continuity of the cost functional and derive the Lipschitz constant in the explicit form via the given data. On the basis of the obtained results, we propose a monotone iteration process. Copyright © 2014 John Wiley & Sons, Ltd.     

Global attractor for the regularized Bénard problem

In this paper, we study the asymptotic behaviour of weak solutions for the regularized Bénard problem. We establish the global existence and uniqueness of weak solutions of this problem and give a proof for the existence of global attractor in the three-dimensional case for this system.     

Expanding stereochemical and skeletal diversity using petasis reactions and 1,3-dipolar cycloadditions

A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis.