Development of Transparent LSCO and LSCNO Conductors for Optical Shutter Systems

We have prepared lanthanum strontium cobalt oxide (La0.50Sr0.50CoO3; LSCO 50/50) and lanthanum strontium cobalt nickel oxide (La0.50Sr0.50Co0.50Ni0.50O3; LSCNO) as candidate transparent electrodes for use in a shutter-based infrared sensor protection device. The shutter device requires that the electrode be transparent (80% transmission) and have moderate sheet resistance (300 Ω/sq.). Because of the effects of film thickness on intrinsic material properties, such as resistivity and extinction coefficient, and simple engineering issues (i.e., the relationship between film thickness, resistance and transmission), films of various thicknesses were prepared to achieve an optimal balance of electrical and optical performance. van der Pauw measurements and FTIR spectroscopy were used to study thin film properties. The best LSCO films prepared demonstrated electrical (438 Ω/sq.) and optical (68% transmission at 8 μm) properties that did not meet the target property goals for this application. However, the LSCNO films (of optimal thickness) offered performance (323 Ω/sq. and 73% transmission) close to the device requirements

Antibacterial activity of cyclo(L-Pro-L-Tyr) and cyclo(D-Pro-L-Tyr) from <i>Streptomyces</i> sp<i>.</i> strain 22-4 against phytopathogenic bacteria

<p>Two bioactive cyclic dipeptides, cyclo(L-Pro-L-Tyr) and cyclo(D-Pro-L-Tyr), were isolated from the culture broth of <i>Streptomyces</i> sp. strain 22-4 and tested against three economically important plant pathogens, <i>Xanthomonas axonopodis</i> pv. citri, <i>Ralstonia solanacearum</i> and <i>Clavibacter michiganensis</i>. Both cyclic dipeptides were active against <i>X. axonopodis</i> pv. citri and <i>R. Solanacearum</i> with MIC of 31.25 <i>μ</i>g/mL<i>.</i> No activity could be observed against <i>C. michiganensis</i>.</p