Search Results

You are looking at 101 - 110 of 1,395 items for :

  • "composites" x
  • All content x
Clear All

The primary aim of the paper is to present a simple method for determining the changes in stiffness of a composite beam. The experimental model was made from wood and plaster boards. It was simply supported beam with a length of 4 m. Accelerations were measured at 24 points along the beam. In either case data for intact and damaged models were acquired. The identification of the damage was done using a code developed by the authors. The vertical mode-shapes were analyzed, so changes in the stiffness could be detected.

Restricted access

Summary The penetration of the phenanthroline ligand into the interlayer space of the Cu-bentonite results in the formation of Cu(Phen)3-bentonite composite. The expansion of the d 001 basal spacing of the Cu-Bent from 14.24 to 17.7 Å on intercalation and the colour change indicate the cation immobilized dimeric ligand species’ presence, which are thermally stable up to 315°C. The shift to higher frequency of the ring vibrations resulted from the π interactions is associated with the linkage of the tilted monomers to the smectite layers at elevated temperatures. The OH stretches and the bending peaks decrease in the intensity in parallel with an easy exchange between the water groups and the aromatic backboned ligands at room temperature.

Restricted access

/modulus, low melt viscosity, low gas permeability, and high chemical/thermal resistances [ 1 – 3 ]. Therefore, TLCPs have been used to blend with a variety of thermoplastics (TPs) to obtain the composite-like materials with a strongly mechanical reinforcement

Restricted access

Introduction Thermoset polymer composites are preferred for many applications because of their strength, dimensional stability, resistance to heat, solvents and corrosive environments. They usually have a high glass transition

Restricted access

Abstract  

Presented work describes mechanical treatment as a non-conventional solid-state process for preparation of some functional materials. Mechanochemical syntheses may be alternative as waste-free and ecologically safer methods of preparing pigments, composites, catalysts, biomaterials, which obey main principles of Green Chemistry.

Restricted access

DTA traces of epoxy resins and composites

Effect of fibers on the polymerization kinetics

Journal of Thermal Analysis and Calorimetry
Authors: A. Schiraldi, P. Baldini, G. Samanni, and M. Gardenal

Four CIBA epoxy composites. A, B, C and D, have been investigated with the aim of verifying the effects of the respective fibers upon polymerization rate.

Restricted access

Abstract  

The thermal diffusivity and the thermal conductivity of polypropylene-based composite polymer were simultaneously measured with a temperature wave analysis method. We can measure the thermal properties under cooling process which are important to consider the polymer processing. The effect of filler in the composite was analyzed by thermal diffusivity and thermal conductivity as a function of temperature. The thermal conductivity of particle dispersed composite was confirmed as a reasonable value and was explained with a series model.

Restricted access

Summary In this study, the thermal properties of agro-flour-filled polybutylene succinate (PBS) bio-composites were investigated. PBS is one of the biodegradable polymers made from the condensation reaction of glycols and dicarboxylic acid and is naturally degraded by natural soil burial system. The thermal properties of the bio-composites were analyzed according to the agro-flour content and mesh size. On increasing agro-flour content, the thermal stability, degradation temperature and derivative thermogravimetric curve (DTGmax) temperature of the bio-composites decreased while the ash content increased. The thermal degradation of the bio-composites was not affected by agro-flour mesh size. The glass transition (T g) and melting (T m) temperatures of the bio-composites were not significantly changed. The storage modulus (E’) of the bio-composites was higher than that of neat PBS, because the incorporation of agro-flour increased the stiffness of the bio-composites. At higher temperatures, E’ of the bio-composites decreased due to the increasing viscosity and chain mobility of neat PBS. The thermal properties of bio-composites have an important effect on the manufacturing system and application methods.

Restricted access

Abstract  

The composite ion exchangers were tested for their ability to remove UO2 2+ from aqueous solutions. Polyacrylonitrile (PAN) composites having natural zeolite, clinoptilolite, and synthetic zeolite, zeolite X, were used as an adsorbents. The influences of pH, U(VI) concentration, temperature and contact time on the sorption behavior of U(VI) were investigated in order to gain a macroscopic understanding of the sorption mechanism. The optimum adsorption conditions were determined for two composites. The sorption behaviors of uranium on both composites from aqueous systems have been studied by batch technique. Parameters on desorption were also investigated to recover the adsorbed uranium.

Restricted access

Nicolau-Catling 1968 = K. Nicolau-H. W. Catling: Composite anchors in late Bronze Age Cyprus. Antiquity 41 (1968) 225-229. Composite anchors in late Bronze Age Cyprus. Antiquity

Restricted access