Ultraviolet-radiation-curing of an organically modified silicate-based material system with epoxy functionality,and the role of titanium

An organically modified silicate-based material system with epoxy functionality was synthesised by the sol–gel method using some certain Si- and Ti-alkoxide precursors. The resultant system was processed with ultraviolet (UV)-radiation. Influences of certain synthesis and process parameters, including Ti content, sol ageing time, and UV-irradiation time, on various properties of the system were detailed. Overall results demonstrated that Ti-based precursors and UV-radiation could be employed to modify the microstructure, and that the final properties of the system might be tuned by an optimal combination of these two parameters. This preliminary study therefore revealed that this technique described herein might be used to develop a new process regime to obtain materials of this type with desired properties.     

The effect of time fractality on the transition coefficients: Historical Stern–Gerlach experiment revisited

In this article, the influence of time discreteness on the transition coefficients is investigated within the framework of time fractional development of quantum systems which has been developed recently by the present authors [22]. In this formalism, fractional mathematics which is a powerful tool to study the non-Markovian and non-Gaussian properties of physical processes is used in order to obtain time fractional evolution operator and transition probability. They are given in terms of Mittag–Leffler function which plays an important role in the mathematical structure as well as the physical interpretation of the phenomena under investigation. In order to place the presented formalism on a concrete basis, historical Stern–Gerlach experiment has been revisited with the purpose of studying transition coefficients which have a non-Markovian feature. The effect of the time fractionalization has been clearly illustrated in the figures via fractional derivative order α.     

Homotopy perturbation method to obtain new solitary solutions with compact support for Boussinesq‐like B(2n, 2n) equations with fully nonlinear dispersion

The aim of this paper is to obtain new solitary solutions with compact support for Boussinesq‐like B(2n, 2n) equations with fully nonlinear dispersion using the homotopy perturbation method (HPM). The special case B(2, 2) is chosen to illustrate the concrete scheme of the HPM in B(2n, 2n) equations. General formulas for the solutions of B(2n, 2n) equations are established. Copyright © 2009 John Wiley & Sons, Ltd.     

Poly(glycidylmethacrylate-co-vinyl ferrocene)-grafted iron oxide nanoparticles as an electron transfer mediator for amperometric phenol detection

An amperometric phenol biosensor was constructed by using poly(glycidylmethacrylate-co-vinyl ferrocene) grafted iron oxide nanoparticles for detection of different phenolic compounds (catechol, aminophenol, phenol, p-cresol, pyrogallol). The poly(glycidylmethacrylate-co-vinyl ferrocene) and nanoparticles were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The copolymer grafted iron oxide nanoparticles and Horseradish peroxidase (HRP) were covalently attached on gold (Au) electrode surface. The effect of pH, temperature and characteristic features such as; reusability and storage stability were studied. The electrode showed good response time within ～3 s. The electrocatalytic response showed a linear dependence on the phenolic compounds concentration ranging from 0.5 to 17.0 mM.     

Statistical Convergence in Probability for a Sequence of Random Functions

In this paper, we introduce a new type of convergence for a sequence of random functions, namely, statistical convergence in probability, which is a natural generalization of convergence in probability. In this approach, we allow such a sequence to go far away from the limit point infinitely many times by presenting random deviations, provided that these deviations are negligible in some sense of measure. In this context, the set of values of a random function is considered as a probabilistic metric (PM) space of random variables, and some basic results are obtained using the tools of PM spaces.     

Molecular alignment during gel formation from methyl methacrylate: An excimer fluorescence study

Glass transition during bulk polymerization was studied in free-radical cross-linking copolymerization (FCC) of methyl methacrylate (MMA) using the steady-state fluorescence (SSF) technique. Naphthalene (N) was used as a monomer and excimer forming probe. Changes in the viscosity of the pregel solutions due to gel formation dramatically enhance both monomer and excimer fluorescent yield of N molecules. The reaction time at which the monomer and excimer intensities exhibit a sudden increase corresponds to the reaction time at which the rate of polymerization becomes maximum resulting from the gel effect. This effect was used to study the gelation of MMA, as a function of time, in various N concentrations. The results were interpreted in the view of percolation theory. The gel fraction, β, and weight average degree of polymerization, γ, exponents β?=?0.40?±?0.02 and γ?=?1.70?±?0.07 were found in agreement with percolation results for both monomer and excimer measurements, respectively.     

Comparison of trace metal concentrations in sediments and algae samples from the Küçükçekmece Lagoon and Marmara Sea

NAA has been applied to determine the concentration of K, As, Se, Zn, Cr, Cs, Fe, Co, Sb, Ni and Ca in sediments and a macroalgae species collected from the Küçükçekmece Lagoon and Marmara Sea. The lagoon sediment showed higher metal levels than the sea sediment. The metal contents in algae species are not changed significantly between months and sampling sites except Zn and Cr. The profile of the lagoon sediments was also investigated.