Prediction of the pipe buckling by using broadening factor with distributed Brillouin fiber sensors

We successfully measured longitudinal strains in two full-scale steel pipe specimens subjected to loading combinations of internal pressure, axial tensile force and bending moments undergoing local buckling under controlled laboratory conditions. Carbon-coated fibers, for the first time, and standard communication fibers were used. By using the broadening factor of the Brillouin spectrum width, we can successfully predict the location and progression sequence of buckling patterns, prior their visual detection in the laboratory. The broadening factor processing time is more efficient than multiple-peak fitting of the Brillouin spectrum method. Thus, it is capable of proving real-time deformation progression in structural health monitoring applications. High strength carbon-coated fibers are found to be superior to standard communication fibers in two respects: they provide more accurate readings and are able to measure significantly larger strains.     

Potential Modulated Attenuated Total Reflectance Spectroscopy of Prussian Blue Films on ITO

Potential modulated attenuated total reflectance (PM-ATR) spectroscopy has been employed to study charge transfer processes in Prussian blue (PB) films deposited on indium tin oxide (ITO) electrodes. PM-ATR is a planar waveguide-based spectroelectrochemical technique in which the optical response of an electroactive film is measured as a function of applied potential and modulation frequency. The multiple internal reflection geometry of PM-ATR provides a significant sensitivity advantage over the single external reflectance geometry that has been employed in most prior electroreflectance studies. The apparent electron transfer rate of PB on ITO obtained using PM-ATR was compared to that obtained with conventional cyclic voltammetry; the respective rates, 0.33 ± 0.15 s⁻¹ (n = 3) and 0.71 ± 0.37 s⁻¹ (n = 10), are in good agreement.     

Removal of copper ions from aqueous solutions by kaolinite and batch design

The removal of copper ions from aqueous solutions by kaolinite was investigated by using a batch-type method. Effects of factors such as pH, ionic strength, temperature, acid-activation and calcination on copper adsorption were investigated. The uptake of copper was determined from changes in concentration as measured by atomic absorption spectrometry. The extent of copper adsorption increased with increasing pH and temperature and with decreasing ionic strength, acid-activation and calcination temperature. The Langmuir and Freundlich adsorption models were used to determine the isotherm parameters associated with the adsorption process. The results provide support for the adsorption of copper ions onto kaolinite. Thermodynamic parameters indicated the endothermic nature of copper adsorption on kaolinite. The experimental results were applied a batch design. As a result, the kaolinite may be used for removal of copper ions from aqueous solutions.     

Removal of copper ions from aqueous solutions by hazelnut shell

There is a great potential of woody hazelnut shell to use in some applications. Sorption studies are one of these. For this reason in this paper, batch adsorption of Cu(2+) ions onto hazelnut shells was studied. The capacity of the adsorption for the removal of copper ions from aqueous solution was investigated under different conditions such as solution contact time (1-360 min), particle size (0-75, 75-150 and 150-200 microm), temperature of solution (25-60 degrees ) and solution pH (3-7). Moreover, zeta potential of particles at different initial pHs (2-10) was measured. The equilibrium data were processed according to Langmuir and Freundlich's models and higher adsorption capacity values towards Cu(2+) ions were shown. The adsorption kinetics was investigated and the best fit was achieved by a second-order equation.     

Self Assembly of Polymer Structures Induced by Electric Field

A method has been developed for fabricating polymer microstructures based on electric field induced self assembly and pattern formation. A dielectric fluid placed in between two conductive plates experience a force in an applied electric field gradient across the plates, which can induce a diffusive surface instability and self construction of the fluid surface. This process is exploited for the fabrication of self assembled polymer microstructures as well as replicated patterns through the use of pre-patterned plates or electrodes. FEM simulation is used to decide the minimum wavelength and electric gradient distribution of polymer structures. A variety of structures in the micron and nanometer scales including bio-fluidic MEMS, polymer optoelectronic devices can be fabricated using this method.