Search results for "COMPOSITE"
showing 10 items of 4584 documents
Molecular Dynamics Study of Copper and Aluminum under Mechanical Strain
1998
AbstractMechanical properties of copper and aluminum have been studied using finite temperature molecular dynamics simulations. Atomic interactions have been described by a many-atom effective medium potential, which takes into account interactions up to third neighbors. The computed elastic constants showed good agreement with experimental data. Encouraged by these results the model was applied to study fracture in copper. Systems with a grain boundary and an initial cut serving as a crack seed have been studied. In the first case, crack nucleation and propagation took place exclusively at the grain boundary. In the second case, dislocation propagation was observed in one of the <110>…
Effect of kind and content of organo-modified clay on properties of PET nanocomposites
2011
In this work we report the properties of nanocomposite based on PET with two different samples of organically modified montmorillonites. In particular, we studied the effect of the filler concentration on morphology, rheology, and mechanical performance, focusing our attention on the effect of the degradation phenomena of the clay modifiers. The results indicate that at low clay level the morphology achieved is mainly intercalated. On increasing the filler level, coalescence and/or bad defragmentation phenomena induce a coarser morphology, as confirmed by XRD, SEM, and TEM observations. When a more polar organic modifier is used to modify the clay, the particle adhesion and distribution is …
Evolution Characteristics of Delamination Damage in CFRP Composites Under Transverse Loading
2012
The initiation and subsequent progression of delamination in CFRP composite laminates is examined using finite element method. A 12-ply CFRP composite, with a total thickness of 2.4 mm and anti-symmetric ply sequence is simulated under three-point bend test setup. Each unidirectional composite lamina is treated as an equivalent elastic and orthotropic panel. Interface behavior is defined using cohesive damage model. Complementary three-point bend test on the specimen is performed at crosshead speed of 2 mm/min. The measured load–deflection response at mid-span location compares well with predicted values. Interface delamination accounts for up to 46.7% reduction in flexural stiffness from t…
Material-driven fibronectin assembly rescues matrix defects due to mutations in collagen IV in fibroblasts
2020
Basement membranes (BMs) are specialised extracellular matrices that provide structural support to tissues as well as influence cell behaviour and signalling. Mutations in COL4A1/COL4A2, a major BM component, cause a familial form of eye, kidney and cerebrovascular disease, including stroke, while common variants in these genes are a risk factor for intracerebral haemorrhage in the general population. These phenotypes are associated with matrix defects, due to mutant protein incorporation in the BM and/or its absence by endoplasmic reticulum (ER) retention. However, the effects of these mutations on matrix stiffness, the contribution of the matrix to the disease mechanism(s) and its effects…
Unveiling anion-induced folding in tripodal imidazolium receptors by ion-mobility mass spectrometry.
2021
The anion-induced folding of tripodal imidazolium receptors has been investigated by NMR spectroscopy, electrospray ionization ion mobility mass spectrometry and DFT calculations. Such folding can be switched by anion release upon collision induced dissociation.
Synthesis of Hierarchically Grown ZnO@NT-WS2 Nanocomposites
2009
A chemically specific and facile method for growth of ZnO nanorods on WS2 nanotubes (NT-WS2) is reported. The modification strategy is based on the chalcophilic affinity of Zn, which serves as an anchor to immobilize ZnO colloids onto the WS2 nanotubes. The surface bound ZnO colloids have been used as a seed to grow ZnO nanorods on WS2 nanotubes. The immobilization of ZnO colloids was monitored by UV−vis spectroscopy and photoluminescence spectroscopy whereas the growth of ZnO nanorods was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Using Taguchi method for the optimization of processing variables to prepare porous scaffolds by combined melt mixing/particulate leaching
2017
Synthetic biopolymers have made significant inroads into the development of devices for tissue regeneration. In this context, a challenge is the achievement of appropriate properties mimicking the natural extracellular matrix by fabricating scaffolds presenting mechanical properties, specific surface, porosity and pore interconnection adequate for the final application. This study involved a systematic procedure based on Taguchi method for parameters optimization of melt mixing/particulate leaching combined processes aiming to enhance the performance of the scaffolds. In particular, it was evaluated the effect of time and temperature of melt mixing of the poly(lactic acid) matrix with two w…
Monitoring multidimensional phenomena with a multicriteria composite performance interval approach
2021
[EN] In the last two decades, the construction of composite indicators to measure and compare multidimensional phenomena in a broad spectrum of domains has increased considerably. Different methodological approaches are used to summarise huge datasets of information in a single figure. This paper proposes a new approach that consists in computing a multicriteria composite performance interval based on different aggregation rules. The suggested approach provides an additional layer of information as the performance interval displays a lower bound from a non-compensability perspective, and an upper bound allowing for full-compensability. The outstanding features of this proposal are: 1) a dis…
Two are not always better than one: ligand optimisation for long-living light-emitting electrochemical cells
2009
The complex [Ir(ppy)2(dpbpy)][PF6] (Hppy = 2-phenylpyridine, dpbpy = 6,6'-diphenyl-2,2'-bipyridine) has been prepared and evaluated as an electroluminescent component for light-emitting electrochemical cells (LECs); the complex exhibits two intramolecular face-to-face π-stacking interactions and long-lived LECs have been constructed; the device characteristics are not significantly improved in comparison to analogous LECs with 6-phenyl-2,2'-bipyridine. Costa Riquelme, Ruben Dario, Ruben.Costa@uv.es ; Orti Guillen, Enrique, Enrique.Orti@uv.es ; Bolink, Henk, Henk.Bolink@uv.es
A model for multilayered beams undergoing end loads
2013
A formulation for layered beams undergoing end loads, namely axial, shear and bending actions, is developed and presented in this paper. A layer-wise kinematical model is first derived so that the point-wise balance relationships are fulfilled at the layer level. Successively, by enforcing the interface continuity conditions and taking the traction–free conditions on the top and bottom surfaces of the laminate into account, the layer-wise kinematical quantities are written in terms of generalized kinematical variables representative of the beam displacements field. The beam problem is then formulated in terms of these generalized variables leading to a model that shows the positive characte…