the nylon and nylon/lycra yarns were coated with electrically conductive polymers such as polyaniline and polypyrrole, via chemical polymerization process. electrical conductivity of the coated yarns was measured at variousstrain levels using two-point probe technique and their strain sensitivities were studied. the results showed that, electrical conductivity of the coated yarns decreased with...

Marine microorganisms have unique physiological properties and novel metabolites such as biosurfactant to live in extreme habitats (e.g. oil polluted environment). The aim of this study was to characterize some biosurfactant-producing bacteria collected from sediment and seawater samples from the Caspian Sea. These bacteria were isolated using enrichment method in ONR7a medium with crude oil as...

background and objective: molecular epidemiological studies have shown that certain genotypes of mycobacterium tuberculosis (mtb) are over-represented in limited geographical regions, suggesting of evolution of certain genotypes with increasing virulence and pathogenicity. beijing strain of mtb was initially described by its potential to cause outbreaks worldwide and its association with drug r...

In this paper, low cycle fatigue life of CK45 steel and SS316 stainless steel under strain-controlled loading are experimentally investigated. In addition, the impact of mean strain and strain amplitude on the fatigue life and cyclic behavior of the materials are studied. Furthermore, it is attempted to predict fatigue life using energy and SWT damage parameters. The experimental results demons...

In this work, dynamic mechanical properties of three high-manganese steels with TRIP/TWIP or fully TWIP characteristics are studied. High strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. All the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). Bu...

Production of oxytetracycline by an isolated strain of Streptomyces rimosus from Iranian soil was investigated using a special fermentation medium. A comparative study was performed with standard strain PTCC 1144 using the following parameters optimum growth conditions with respect to time, pH, and different amounts of corn steep liquor. Surprisingly, the production yield of the wild strai...

in this paper, the accumulative channel-die compression bounding (accb) method is investigated as a new method of severe plastic deformation to produce nano-crystalline bulk metals on the basis of pressing in a channel mold. aluminum as one of the most usable metal in industry is processed using this method. analyzing the processed samples show that after four passes of accb method, the ultimat...