Materials Engineering

This experimental field study interrupted the protection current offered by Impressed Current Cathodic Protection (ICCP) to ten in-service reinforced concrete structures. The study aimed to identify the long-term effects of ICCP after it was recognised that some of the systems are now reaching the end of their design life and require a significant level of maintenance. It was found that after five or more years of ICCP, the steel remained passive for at least 24 months after interrupting the protection current despite chloride contamination that would represent a corrosion risk.

Conducting polymers are excellent microwave absorb-ers and they show technological advantage when com-pared with inorganic electromagnetic absorbing materi-als, being light weight, easily processable, and the ability of changing the electromagnetic properties with nature and ...

— In digital communication system, digital information can be sent on a carrier through changes in its fundamental characteristics such as phase, frequency and amplitude. The use of a filter plays an important part in a communication channel because it is effective at eliminating spectral leakage, reducing channel width, and eliminating interference from adjacent symbols (Inter Symbol Interference) ISI. It describe the developed and dynamic method of designing finite impulse response filter with automatic rapid and less error by an efficient genetic and neural approach. GA and Neural are powerful global optimization algorithm introduced in combinational optimization problems. Here, FIR filter is designed using Genetic, Neural approach by efficient coding schemes. We need to design these filters with some constraints imposed by requirements of the communication system in which we are going to use them. The use of optimization techniques have been proved to be quite useful towards the design of those digital filters with certain specifications. This paper reviews about the uses of optimization systems in digital filter design.

The crystal structure and the cationic distribution of BaFe4Ti2O11 R-type hexagonal ferrite has been studied from room-temperature powder neutron diffraction and 57Fe Mössbauer spectroscopy data. The compound is hexagonal (S.G.: P63/mmc, Z = 2) with cell parameters and . Our data indicate that in BaFe4Ti2O11 the 5-fold sublattice is only occupied by Fe ions, while the two remaining octahedral sublattices are occupied by Fe and Ti ions with a slight preference of Ti ions for the 4e octahedral sites. As in the BaFe12O19 M-structure, the 5-fold Fe cations present a disorder between the two pseudotetrahedral sites forming the trigonal bipyramid. Our Mössbauer spectroscopy results seem to suggest that this disorder is a static one. The remaining cationic polyhedra show some important additional distortions, as compared to BaFe12O19 M-structure, which are likely due to the augmented intercationic electrostatic repulsion.

Torsion extrusion (TE) process was performed successfully for consolidation of commercially pure aluminum powder at 350 °C. It was shown by a specific mechanism that the shear strains applied during consolidation of aluminum powder by the TE process have a considerable effect on the micro-structural shape of the porosities and also their omission efficiency. Density measurements showed that in the TE process a better consolidation, with respect to hot forward extrusion, was accomplished. Tensile and hardness tests results showed superior values for the ultimate tensile strength (UTS) and hardness values in the specimens produced by the TE process.