Nanostructured ZrO2 Thick Film Resistors as H2-Gas Sensors Operable at Room Temperature

Nanostructured ZrO2 powder was synthesized by microwave assisted sol-gel method. The material was characterized by XRD and SEM techniques. X-Ray diffraction studies confirm that a combination of tetragonal and monoclinic zirconia nanoparticles is obtained by using microwave-assisted method. The nanopowder was calcined at an optimized temperature of 400 °C for 3 h. The prepared powder had crystalline size about 25 nm. Thick films of synthesized ZrO2 powder were prepared by screen printing technique. The gas sensing performances of these films for various gases were tested. Films showed highest response to H2 (50 ppm) gas at room temperature with poor responses to others (1000 ppm). The quick response and fast recovery are the main features of this sensor. The effects of microstructure, operating temperature and gas concentration on the gas response, selectivity, response time and recovery time of the sensor in the presence of H2 gas and others were studied and discussed

Synthesis and characterization of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and mercury(II) complexes with 2-hydroxyimino-3-(2' -imino-4-phenylthiazolyl)-butane and 2-hydroxyimino-3-[2' -imino-4' (<i>p-</i>tolulylthiazolyl)]-butane

1145-1149The complexes of the composition [M(HL)2(H2O)2].Cl2 [HL = 2-hydroxyimino-3-(2'-imino-4-phenylthiazolyl)butane(HL1), 2-hydroxyimino-3-[2'-imino-4-(p-tolulylthiazolyl)]-butane(HL2)]; M=Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)] have been synthesised and characterised by elemental analysis, magnetic susceptibility, molar conductance, TGA, X-ray diffraction and spectral studies. HL1 and HL2 acts as neutral bidenate ligands and the complexes appear to be octahedral. Antibacterial activities of ligands and their metal complexes have been determined against Escherichiacoli, Bacillus substilis; Klebsiella pbeumoniae, Pseudomonas aerogens, Salmonalla paratyphi B, Staphylococcus aureus, and Proteus vulgaris.</i

Synthesis and X-ray diffraction studies of 4-[2'-hydroxy salicylidene-5' (2"-thiazolylazo)] methoxy benzene

817-820<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">The new compounds having azo Schiff base characteristics have been synthesized by condensing 5-(2'-thiazolylazo) salicylaldehyde with para-substituted aniline and subjected for structural characterization. X-ray diffraction study has been carried out for 4-[2'-hydroxy salicylidene-5'-(2'-thiazolylazo)]methoxy benzene. The structure of compound is found to be <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">tetragonal, belonging to non-primitive system. The strain broadening effects are also examined and discussed. </span