Search results for "Composite"

1980

Compression creep and stress-relaxation tests have been performed on PMMA at several deformations after the sample yielding. At large loading rates, the behaviour observed was found significantly affected by the temperature rise due to the plastic deformation. Creep and stress-relaxation data taken holding the samples at constant temperature after the material loading could be collected into single curves by means of a time shift factor proportional to the loading rate. Retardations- und Relaxationsuntersuchungen bei Druckbeanspruchung von PMMA wurden bei verschiedenen Deformationen oberhalb des Fliespunktes durchgefuhrt. Bei hohen Beanspruchungsgeschwindigkeiten wurde festgestellt, das das…

A Study on the Propagation of Plane Stress Waves across the Thickness of a Plate by the Method of Analytic Continuation in Time

2004

The interaction of plane tension/compression waves propagating within a plate perpendicularly to its surface is considered. The analytic solution is obtained by a modified method of characteristics for the one-dimensional wave equation used in problems on an impact of a rigid body on the surface of a plate. The displacements, velocities, and stresses in the plate are determined by the edge disturbance caused by the initial velocity and the stationary force field of masses of the striker and the plate. The method of analytic continuation in time put forward allows a stress analysis for an arbitrary time interval by using finite expressions. Contrary to a stress analysis in the frequency doma…

An assembly of organic-inorganic composites using halloysite clay nanotubes

2018

Halloysite is natural tubular clay suitable as a component of biocompatible nanosystems with specific functionalities. The selective modification of halloysite inner/outer surfaces can be achieved by exploiting supramolecular and covalent interactions resulting in controlled colloidal stability adjusted to the solvent polarity. The functionalized halloysite nanotubes can be employed as reinforcing filler for polymers as well as carriers for the sustained release of active molecules, such as antioxidants, flame-retardants, corrosion inhibitors, biocides and drugs. The tubular morphology makes halloysite a perspective template for core-shell metal supports for mesoporous catalysts. The cataly…

Role of organo-modifier and metal impurities of commercial nanoclays in the photo-and thermo-oxidation of polyamide 11 nanocomposites

2020

The photo-oxidative degradation processes of bio-based PA11 nanocomposites containing montmorillonite (MMT) and the organo-modified Cloisite&reg

Determination of the oxygen transmissibility and permeability of hydrogel contact lenses

1999

To test the validity of the method of stacked hydrogel contact lenses to obtain the oxygen permeability and transmissibility coefficients of the lenses, the coefficients of one low hydration (38% water) and two high hydration (55 and 58% water) hydrogel contact lenses stacked one to five on an oxygen electrode were deter- mined. From the oxygen diffusion through the lenses, the current intensity in the stationary state was determined, and from this the "instrument" the oxygen transmis- sibility was obtained. The permeability coefficients of the lenses, corrected for edge effects, were obtained from the slope of the plot of the reciprocal of the transmissibility coefficients versus the lens …

Ultra-small gold nanoclusters assembled on plasma polymer-modified zeolites: a multifunctional nanohybrid with anti-haemorrhagic and anti-inflammator…

2021

Refereed/Peer-reviewed Hemostatic agents are pivotal for managing clinical and traumatic bleeding during emergency and domestic circumstances. Herein, a novel functional hybrid nanocomposite material consisting of plasma polymer-modified zeolite 13X and ultra-small gold nanoclusters (AuNCs) was fabricated as an efficient hemostatic agent. The surface of zeolite 13X was functionalised with amine groups which served as binding sites for carboxylate terminated AuNCs. Protein corona studies revealed the enhanced adsorption of two proteins, namely, coagulation factors and plasminogen as a result of AuNCs immobilization on the zeolite surface. The immune response studies showed that the hybrid na…

NO2-controlled cargo delivery from gated silica mesoporous nanoparticles

2017

[EN] Cargo delivery from mesoporous silica nanoparticles loaded with sulforhodamine B and capped with a difluoroboron-dipyrromethene (BODIPY) derivative was triggered by a NO2-induced oxidative process.

Coordination polymers undergoing spin crossover and reversible ligand exchange in the solid

2006

Here we report the synthesis and characterisation of a polymer made up of a system of parallel 2-D grids of Fe(II) ions linked by [Au(CN)2]– bridges and its transformation into a new system of three interpenetrated 3-D coordination open frameworks with the NbO topology. Reversibility of this crystal-to-crystal transformation is evidenced by X-ray crystallographic data and from their spin crossover properties. Real Cabezos, Jose Antonio, Jose.A.Real@uv.es

A family of higher-order single layer plate models meeting Cz0-requirements for arbitrary laminates

2019

Abstract In the framework of displacement-based equivalent single layer (ESL) plate theories for laminates, this paper presents a generic and automatic method to extend a basis higher-order shear deformation theory (polynomial, trigonometric, hyperbolic…) to a multilayer C z 0 higher-order shear deformation theory. The key idea is to enhance the description of the cross-sectional warping: the odd high-order C z 1 function of the basis model is replaced by one odd and one even high-order function and including the characteristic zig-zag behaviour by means of piecewise linear functions. In order to account for arbitrary lamination schemes, four such piecewise continuous functions are consider…

Heptanuclear hydroxo-bridged copper cluster of the dicubane-like type: structural and magnetic characterisations of [Cu7(OH)6Cl2(pn)6(H2O)2](C(CN)3)4…

2002

A new polynuclear copper(II) complex [Cu7(OH)6Cl2- (pn)6(H2O)2](C(CN)3)4Cl2 with hydroxo-bridging ligands has been prepared; the centrosymmetric cluster cation can be described as two Cu4O3Cl distorted cubane units sharing one copper cation. Clemente Juan, Juan Modesto, Juan.M.Clemente@uv.es ; Gomez Garcia, Carlos Jose, Carlos.Gomez@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es