The model complex [(64)Cu((S)-p-NH(2)-Bn-NOTA)](-) ([(64)Cu]1) was used to study the isomerism of [(64)Cu-NOTA-Bn]-labeled radiotracers. Two complex isomers [(64)Cu]1a and [(64)Cu]1b, which were formed at a ratio of 1:9 during the complexation of [(64)Cu]Cu(2+) with (S)-p-NH(2)-Bn-NOTA, were separated using ion pair chromatography. To study the interconversion, the nonradioactive complex isomers Cu1a and Cu1b were separated and thermally treated at 90 °C in both ammonium acetate solution and deionized water. A faster interconversion rate was observed for both isomers with lower concentrations of ammonium ions. At the end of reaction, the thermodynamic Cu1a to Cu1b equilibrium ratio was 6:94. The particular energy barriers of the interconversion for Cu1a and Cu1b were 130 kJ mol(-1) and 140 kJ mol(-1). Spectrophotometric measurements with Cu1a and Cu1b revealed two isomers adopting different geometrical configurations.

Dielectric polyvinylidene fluoride (PVDF) and Barium titanate (BaTiO3)-PVDF nano-fibrous composites were made using the electrospinning process based on a design of experiments approach. An ultrasonication process was optimized using 2 k factorial DoE approach to disperse BaTiO3 particles in PVDF solution in DMF. Scanning electron microscopy was used to characterize the microstructure of the fabricated mesh. The FT-IR and Raman analysis were carried out to investigate the crystal structure of the prepared mesh. Surface morphology contribution to the adhesive property of the composite was explained through contact angle measurements. The capacitance of the prepared PVDF-BaTiO3 nanofibrous mesh was a more than 40% increase over the pure PVDF nanofibers. The results obtained indicates that electrospinning offers a potential way to produce nanofibers with desired crystalline nature which was not observed in molded samples. In addition, BaTiO3 can be used to increase the capacitance, desired surface characteristics of the PVDF nanofibers which can find potential application as flexible piezoelectric sensor mimicking biological skin for use in structural health monitoring applications.

Bast fibers grow in the bark layer of many plants and have been used for textiles and cordage for over 6000 years. Bast fibers are expanding into new markets of non-woven fabrics and composite materials, and a comparative assessment of surface reactive groups and mechanical properties after different retting procedures is of value. Here, bast fiber of kenaf ( Hibiscus cannabinus L., Malvaceae) were prepared by (1) alkali retting with 2% NaOH and (2) enzymatic retting with pectinase, and compared with commercially-available fiber retted by the natural microbe population in ocean water. Fiber structure was analyzed by fluorescence and electron microscopy; fiber chemistry was assessed by Raman and X-ray photoelectron spectroscopy, and by carbohydrate analysis; and mechanical properties were determined by dynamic mechanical analysis. Collectively, these show that enzymatic and microbial retting preserve the natural fiber structure and result in superior mechanical properties compared with alkali retting, which disrupts structure and degrades quality. The impacts of the retting procedure on fiber chemistry, morphology and mechanical properties are discussed.

Photoproduction of hydrogen by Rhodopseudomonas palustris KU003 under different cultural conditions with various carbon and nitrogen sources was investigated. Hydrogen production was measured using a Gas chromatograph. Malate promoted more amounts of hydrogen production under anaerobic light conditions than anaerobic dark conditions. Cumulative hydrogen production by the organism was recorded at various time intervals. Incubation period of 120 hrs was optimum for production of hydrogen. pH 7.0 ± 0.4 was optimum for production of hydrogen. L-glutamic acid was a good nitrogen source for production of hydrogen. Growing cells produced more amount of hydrogen than resting cells. Significance of the above results in presence of existing literature is discussed.