Search results for "COMPOSITE"
showing 10 items of 4584 documents
Studies and Research on the Stress – Strain Analyses of the Polyethylene Pipe-Fitting Assemblies Accidentally Subjected to an External Force
2019
Abstract The paper aims at analyzing the behavior of the polyethylene pipe - fitting assembly in the case of accidental stress due to the accidentally occurring external forces (mechanized excavation in the assembly area). The study will identify the necessary computing relationships and the minimum value of the force to which the analyzed assembly breaks, as well as some solutions for avoiding these accidental stresses. A three-dimensional model of the assembly will be made by applying the external forces on three main directions, following the maximum stresses for the same value of the external force. Also, a welding of a polyethylene pipe-fitting assembly will be carried out and it will …
Structure and mechanical properties of Al–B composite powder
1997
Abstract Al-B composite powder has been obtained by crushing pieces of composite material presenting industrial waste. Structural peculiarities and microhardness of separate powder particles (d∼1 mm) have been investigated. Original design of high precision microhardness tester made it possible to detect the properties of powder both in near-surface layer and below it. The powder represents a new structurally non-homogenous material with the increased microhardness (1.5 GPa) which grows up to 4 GPa in near-surface layers. Stable oxide compounds are formed on internal surfaces and defects of the aluminium alloy. Powder compacts were obtained. Adhesion on Al–B and Al–Al interfaces at various …
Mechanical properties and XRD of Nafion modified by 2-hydroxyethylammonium ionic liquids
2013
In this work, the Nafion 112 membrane impregnated with 2-hydroxyethylammonium carboxylate ionic liquids have been investigated. The used ionic liquids were 2-hydroxyethylammonium formate [HEA]F, acetate [HEA]A and lactate [HEA]L. Prepared composite membranes Nafion/ionic liquid are characterized by mechanical testing, such as tensile test and creep test. It is found that ionic liquids decrease elastic modulus and creep compliance, but do not have significant effect on the tensile strength. Also, composite membranes were studied by wide angle X-ray diffraction. All ionic liquids shift the peak maximum to the lower angle. In this work, only biodegradable ionic liquids were used for composite …
Manufacturing, structure and properties of recycled polyethylene terephthalate /liquid crystal polymer/montmorillonite clay nanocomposites
2013
Polyethylene terephthalate (PET)/liquid crystal polymer (LCP)/monthmorillonite clay (MMT) compositions were obtained by melt mixing. Their mechanical, structural, rheological and thermal properties were investigated.
CdSe-Sensitized p-CuSCN/Nanowire n-ZnO Heterojunctions
2005
Morphological Characterisation of Bacterial Cellulose-Starch Nanocomposites
2008
Acetobacter sp. growing medium was modified in order to produce bacterial cellulose (BC) nanocomposites using a bottom-up technique that allowed starch to be introduced into the cellulose network. The BC-starch mats were hot-pressed to obtain nanocomposites sheets. Morphological characterisation was carried out using Atomic Force Microscopy and Environmental Scanning Electron Microscopy. The images obtained from microscopy were then processed using image analysis. Network properties, such as mesh size and fibre orientation were characterised. Fracture surfaces of these new nanocomposites were analysed.
Electrical tree growth in EVA-layered silicate nanocomposites
2006
This work deals with the growth of electrical treeing in different EVA-layered silicate nanostructured compounds. The experimental activity evidenced that the intercalated nanocomposites have longer lifetimes than pure EVA under the same constant AC stress conditions. A monitoring of the tree growth morphology allowed to evidence very interesting features of the intercalated nano-compounds showing a barrier effect to the treeing path. A preliminary investigation on the possible arrangement of the filler particles inside the matrix was also carried out.
ChemInform Abstract: Palladium-Polypyrrole Nanocomposites Pd@PPy for Direct C-H Functionalization of Pyrroles and Imidazoles with Bromoarenes.
2016
Palladium–polypyrrole nanocomposites (Pd@PPy) with unique combination of high palladium dispersion (nanoparticle size 2.4 nm) and high palladium content (35 wt%) are efficient catalysts for the selective arylation of substituted pyrroles and imidazoles with either activated or deactivated aryl bromides. The performances of the recoverable supported palladium catalyst matches the best performances of homogeneous systems based on Pd(OAc)2 at 0.5–0.2 mol%, and largely overwhelm the classical Pd/C catalyst.
New Porphyrin/Fe-Loaded TiO2 Composites as Heterogeneous Photo-Fenton Catalysts for the Efficient Degradation of 4-Nitrophenol
2013
A new class of porphyrin(Pp)/Fe co-loaded TiO2 composites opportunely prepared by impregnation of [5,10,15,20-tetra(4-tert-butylphenyl)] porphyrin (H2Pp) or Cu(II)[5,10,15,20-tetra(4-tert-butylphenyl)] porphyrin (CuPp) onto Fe-loaded TiO2 particles showed high activities by carrying out the degradation of 4-nitrophenol (4-NP) as probe reaction in aqueous suspension under heterogeneous photo-Fenton-like reactions by using UV-visible light. The combination of porphyrin-Fe-TiO2 in the presence of H2O2 showed to be more efficient than the simple bare TiO2 or Fe-TiO2.