Thin films of Ln1−xn_{^1-x}Srxr_{^x}CoO3O_{^3} (Ln=La, Nd and Gd) and SrRuO3RuO_{^3} by nebulized spray pyrolysis

Thin films of La1-xSrxCoO3, Nd0.5Sr0.5CoO3, Gd0.5Sr0.5CoO3 and SrRuO3 have been deposited on Si(100), LaAlO3(100) and SrTiO3(100) single crystal substrates by nebulized spray pyrolysis. The films deposited on Si are generally polycrystalline, but they are highly oriented on the oxide substrates. The cobaltate films are generally not metallic, but exhibit low resistivity specially when x = 0.3 and 0.5, the latter also exhibiting ferromagnetic characteristics. Films of La0.7Sr0.3CoO3 show negative magnetoresistance of 35% around 180 K. Films of SrRuO3 are metallic on Si and LaAlO3 substrates but show an insulator-metal transition on SrTiO3 around 130 K, around which temperature negative magnetoresistance is observed

Comparative Catalytic Properties of Ni(OH)2 and NiO Nanoparticles Towards the Degradation of Nitrite (NO2 - ) and Nitric Oxide (NO)

Nitrite (NO2 - ) and nitric oxide (NO) have been identified as an environmentally hazardous analytes from discharged industrial effluents. Thus in this study, nickel oxide (NiO) and nickel hydroxide (Ni(OH)2) nanoparticles were synthesized using the complexation-precipitation method and their catalytic properties towards NO2 - and NO investigated. The success of the synthesised nanoparticles was confirmed using characterisation techniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and the Fourier transformed infrared (FTIR) spectroscopy. The sizes of the synthesized NiO and Ni(OH)2 nanoparticles were estimated to be 5.39 and 5.07 nm respectively. The catalytic behaviour of NiO and Ni(OH)2 nanoparticles towards the oxidative degradation of NO and NO2 - in acidic and neutral media respectively was studied using UV-Vis spectrophotometer. Result indicated that NiO nanoparticles demonstrated better catalytic properties at different reaction time towards NO2 - and NO oxidation compared to Ni(OH)2, while NiO and Ni(OH)2 at nano scale showed enhanced catalysis towards the analytes compared with the bulk Ni salt. The bulk Ni salt did not show any sensing properties towards NO2 - . However in NO, the absorbance intensity due to the generation of nitrate (NO2 - ) was five times higher in the presence of NiO nanoparticles compared with the bulk Ni salt. The improved catalysis of Ni(OH)2 and NiO nanoparticles in this study was attributed to effective pore sizes and large surface area which expose the analytes to more catalytic site. The nanoparticles are simple to prepare, therefore can be used for the fabrication of a simple, portable, miniaturized nitrite and nitric oxide nanosensor for potential clinical and analytical application

Effect of carbamate molluscicide on African giant land snail Limicolaria Aurora

The effect of 50, 100, 200, 300, 400 and 500mg/ml of carbamate molluscicide on the behavioural and macroscopic changes of Limicolaria aurora were investigated in the laboratory using Carica papaya as bait for 120h. The data showed that 48h after dosing the organism with furadan, 60% mortality was recorded. Above 200mg/ml deters snails from feeding and becomes sub-lethal. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 99-10