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.
Authors:A. Tabak, B. Afsin, S. F. Aygun, and H. Icbudak
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 d001 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.
/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
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
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.
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.
Authors:H.-S. Kim, H.-S. Yang, H.-J. Kim, B.-J. Lee, and T.-S. Hwang
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 (Tg) and melting (Tm) 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.
The composite ion exchangers were tested for their ability to remove UO22+ 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.