Search results for "Composites"
showing 10 items of 1905 documents
Development of curcumin loaded sodium hyaluronate immobilized vesicles (hyalurosomes) and their potential on skin inflammation and wound restoring.
2015
In the present work new highly biocompatible nanovesicles were developed using polyanion sodium hyaluronate to form polymer immobilized vesicles, so called hyalurosomes. Curcumin, at high concentration was loaded into hyalurosomes and physico-chemical properties and in vitro/in vivo performances of the formulations were compared to those of liposomes having the same lipid and drug content. Vesicles were prepared by direct addition of dispersion containing the polysaccharide sodium hyaluronate and the polyphenol curcumin to a commercial mixture of soy phospholipids, thus avoiding the use of organic solvents. An extensive study was carried out on the physico-chemical features and properties o…
Structure and magnetic properties of AgFeP2O7
2010
Abstract AgFeP2O7 has been synthesized by flux crystallization and characterized by single crystal and powder X-ray diffraction (sp. gr. P21/c, a=7.3298(2), b=7.9702(2), c=9.5653(2) A, β=111.842(1)°, V=518.68(2) A3) and FTIR-spectroscopy. The structure is composed of isolated iron octahedra and phosphate tetrahedra interconnected into 3D network with hexagonal channels, where silver counter-ions are located. The magnetic behavior of the compound approaches the Curie–Weiss equation with a Weiss constant θ=−165.9 K indicating strong antiferromagnetic interaction between iron(III) ions.
A novel two-dimensional honeycomb-like bimetallic iron(iii)–nickel(ii) cyanide-bridged magnetic material [Ni(cyclam)]3[Fe(CN)6]2·nH2O (cyclam = 1,4,8…
1999
The 2D honeycomb-like layered iron(iii)–nickel(ii) cyanidebridged complex [Ni(cyclam)]3[Fe(CN)6]2·nH2O exhibits ferromagnetic intralayer and antiferromagnetic interlayer interactions; above 3 K the magnetic properties are typical of a metamagnet with Hc = 5000 G, whereas below 3 K a canted structure is formed, leading to a long range ferromagnetic ordering. Lloret Pastor, Francisco, Francisco.Lloret@uv.es
Micromechanisms of load transfer in a unidirectional carbon fibre–reinforced epoxy composite due to fibre failures. Part 2: Influence of viscoelastic…
2006
A local three-dimensional (3D) finite element analysis (FEA), of the mechanisms governing composite damage (in the region around a fibre break), has been carried out. The model considers viscoelastic and plastic matrix behaviours with and without debonding at the broken fibre/matrix interface. The finite element analysis has shown that even a simple viscoelastic law describing the behaviour of the epoxy resin leads to an increasing load on the neighbouring intact fibres, as a function of time. The plastic behaviour of the matrix has been shown to have consequences on reloading after unloading. In contrast to other studies reported in the literature, the calculations were carried out on diff…
Modelling of Pe C alloys solidification using the artificial heat source method
1997
Abstract In the paper the numerical solutions concerning the cast iron and also the carbon steel solidification are presented. In order to take into account the non-linearities appearing in differential equations describing the boundary-initial problem considered — a certain algorithm called the artificial heat source method has been used. The examples illustrating the possibilities of proposed method applications have been solved by means of the boundary element method, but the others numerical methods can be also utilized.
DIRECT NUMERICAL SIMULATION OF MOTION OF FERROMAGNETIC PARTICLES IN MAGNETORHEOLOGICAL SUSPENSION
2008
ABSTRACT Results simulation of magnetorheological suspension at particle level are reported. The present approach accounts for a better description of hydrodynamic interaction between close spheres. Development of lamellar structures similar to those obtained by other researchers in Poiseuille flow is observed in shear flow. Studies of single layer lamellar structures reveal presence of short chains and more complex aggregates.
On the dynamics of non-local fractional viscoelastic beams under stochastic agencies
2018
Abstract Non-local viscoelasticity is a subject of great interest in the context of non-local theories. In a recent study, the authors have proposed a non-local fractional beam model where non-local effects are represented as viscoelastic long-range volume forces and moments, exchanged by non-adjacent beam segments depending on their relative motion, while local effects are modelled by elastic classical stress resultants. Long-range interactions have been given a fractional constitutive law, involving the Caputo's fractional derivative. This paper introduces a comprehensive numerical approach to calculate the stochastic response of the non-local fractional beam model under Gaussian white no…
Optimization of MCM-41 type silica nanoparticles for biological applications: Control of size and absence of aggregation and cell cytotoxicity
2015
Abstract Mesoporous silica nanoparticles were synthesized at high pH using CTAB as a template and TEOS as a silica precursor. It was shown that varying the NaOH concentration between 5 and 27.5 mM allows the size, pore and silica structure of mesoporous nanoparticles to be precisely tuned. In particular, monodisperse nanoparticles with the MCM-41 structure with size ranging from 90 nm to 450 nm were obtained by increasing the NaOH concentration from 12.5 to 22.5 mM. It thus demonstrates that NaOH concentration must range between 12.5 and 15 mM in order to prepare MCM-41 silica nanoparticles with optimal size for nanovectorization. We also found that under usual conditions the aggregation of…
Citrate–nitrate auto-combustion synthesis of perovskite-type nanopowders: A systematic approach
2009
Abstract Citrate–nitrate auto-combustion synthesis is used to prepare an iron, a cobalt and a cerium-perovskite. The influence of different synthesis conditions on the combustion process, phase composition, textural and morphological properties is studied in detail by X-ray diffraction, nitrogen adsorption and scanning electron microscopy. Results show that the combustion intensity increases from iron, to cerium, to cobalt-perovskite. Conversely, the combustion intensity decreases and thus the safety and the gain of the combustion process increase by using high fuel/oxidant ratios, low pH values or combustion reactors with high heat dispersion capacity. High fuel/oxidant ratios increase par…
Yttrium-doped hematite photoanodes for solar water splitting: Photoelectrochemical and electronic properties
2018
Abstract We investigate yttrium-doped hematite thin-film photoelectrochemical properties and find yttrium incorporation to amply improve the performance as a photoanode for water splitting under visible light. We used the spray pyrolysis method to prepare a set of yttrium doped Fe2-xYxO3 (x = 0, 0.05, 0.10, 0.15, 0.2) thin films (thickness below 500 nm) on glass and transparent conductive oxide coated glass slides. Using a substitutional homovalent (Y3+) dopant, the effect on functionality is rationalised as a combined effect on the electronic structure and small polaron mobility from the lattice structure, impurity levels, lattice stability and variance in hybridisation. The photoelectroch…