Macroporous SnO2 (mp-SnO2(P-n); P means polymethylmethacrylate (PMMA) and n = diameter of PMMA microsphere) thick film gas sensors were fabricated by a modified sol-gel method by employing PMMA microspheres (n = 800, 400, 250 and 150 nm) as a template and SnCl2 as a tin source. Morphology of mp-SnO2 films was markedly dependent on the SnCl2 concentration and the diameter of PMMA microspheres. E...

In this study, we tailor the microstructure of hydroxyapatite/zirconia nanocrystalline composites by optimizing processing parameters, namely, introducing an atmosphere of water vapor during sintering in order to control the thermal stability of hydroxyapatite, and a modified sol-gel process that yields to an excellent intergranular distribution of zirconia phase dispersed intergranularly withi...

Bimodal nanoprobes comprising both magnetic and optical functionalities have been prepared via a sequential two-step process. Firstly, magnetite nanoparticles (MNPs) with well-defined cubic shape and an average dimension of 80 nm were produced by hydrolysis of iron sulfate and were then surface modified with silica shells by using the sol-gel method. The Fe₃O₄@SiO₂ particles were then functiona...

Both firstand second-order logic (FOL and SOL, respectively) as we use them today were arguably created by Frege in his Begriffsschrift – if we ignore the notational differences. SOL also suggests itself as a natural, and because of its much greater strength, desirable extension of FOL. But at least since W. V. Quine’s famous claim that SOL is “set theory in sheep’s clothing” it is widely held ...

We report that oxidized multiwalled carbon nanotubes (MWCNTs) can be synchronously dispersed and functionalized in TiO2 sol via an in situ sol-gel process. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy (AFM) were used to characterize the functionalized MWCNTs. The results revealed that the hydrolysis and condensat...

We show that if M is an oriented closed geometric four manifold the following notions are equivalent, (i) M has zero minimal entropy, h(M) = 0. (ii) M collapses with bounded curvature, VolK(M) = 0. (iii) The simplicial volume of M vanishes, ||M || = 0. (iv) M admits a T -structure. (v) M is modelled on one of the geometries S, CP , S × E, H × E, S̃L2 × E, Nil × E, Nil, Sol 1 , S × E, H × E, Sol ...

The spectral problem of the three-dimensional manifolds M3 A admitting Sol-geometry in Thurston’s sense is investigated. Topologically M3 A are the torus bundles over a circle with a hyperbolic glueing map A. The eigenfunctions of the corresponding Laplace-Beltrami operators are described in terms of the modified Mathieu functions. It is shown that the multiplicities of the eigenvalues do not d...

In this paper a novel elctrochemical HbA1c biosensor based on flow injection and screen-printed electrode was developed. The reticulated vitreous carbon (RVC) electrode was modified with 3aminophenylboronic acid, chitosan (CS), and tetraenthoxyl silica (TEOS), which entrapped carbon nanotubes to form a sol-gel film at the surface of the screen-printed electrode. The electrochemical behavior of ...

Co3 O4 -modified CeO2 (Co/Ce 1:4) was prepared by a combination of sol-gel processing and solvothermal treatment. The distribution of Co was controlled by means of the synthesis protocol to yield three different morphologies, namely, Co3 O4 nanoparticles located on the surface of CeO2 particles, coexistent Co3 O4 and CeO2 nanoparticles, or Co oxide structures homogeneously distributed within Ce...

The paper proposed a method to improve the anti-oxidation performance of carbon fibers (CF) at high temperature environment by coating silicon dioxide (SiO₂) and silicon carbide (SiC). The modified sol-gel method had been used to ensure the proper interface between fibers and coating. We used polydimethylsiloxane and ethyl orthosilicate to make stable emulsion to uniformly disperse SiC nanopart...