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Multiple sensor array comprising 16 x 2 sensing elements were realized using RF sputtered WO3 thin films. The sensor films were modified with a thin layer of sensitizers namely Au, Ni, Cu, Al, Pd, Ti, Pt. The resulting sensor array were tested for their response towards different gases namely H2S, NH3, NO and C2H5OH. The sensor response values measured from the response curves indicates that the sensor array generates a unique signature pattern (bar chart) for the gases. The sensor response values can be used to get both qualitative and quantitative information about the gas. [ABSTRACT FROM AUTHOR]

Hydrothermal growth of ZnO nanowires were performed using ZnO nanoparticles as a seed layer. The growth was found to depend strongly on the reaction duration. These nanowires detected H2S with faster response and recovery time of 13 and 78 s, respectively towards 20 ppm at 350° C. The lowest detection limit was improved to 0.6 ppm upon annealing in O2 flow of 50 sccm. The response time was further improved to just 6 s towards 20 ppm of H2S at 350° C. The enhanced response characteristics have been attributed to the high surface area to volume ratio of nanowires. Photoluminescence (PL) studies showed increase in the green emission related to defect states in ZnO. This is also expected to contribute for the improved sensing characteristics. [ABSTRACT FROM AUTHOR]

Fabrication of a 2 × 4 multiple sensor array based on SnO2 thin films was demonstrated. SnO2 thin films were deposited on Al2O3 substrates and modified selectively using Au and CuO by sputtering. The sensor array was tested for its gas sensing characteristics towards H2S. The maximum sensor response (S=52) was observed in case of Au modified SnO2 thin films. By the surface modification using Au there is increase in the sensor response at all temperature. With the increase in temperature, sensor response decreases. [ABSTRACT FROM AUTHOR]

A 2 × 3 sensor array based on pure, Au and CuO modified (two of each kind) WO3 films was fabricated for e-nose application. Effect of surface modification has been investigated and correlated with the observed sensor response values. The sensor array was able to detect H2S,NH3 and NO selectively based on the sensor response pattern exhibited by the sensor array. WO3 sensor film modified with CuO exhibited a maximum sensitivity towards H2S (S = 92, 10 ppm, 250°C) while pure WO3 films exhibited better sensing characteristics towards NO (S=2.3, 10 ppm, 300°C) and NH3 (S=4.5, 50 ppm, 300°C). The shape of the curve remains unaltered by the change in the concentration of the gas. The shape and position of the combined response curve could be used to determine an unknown gas both qualitatively and quantitatively. [ABSTRACT FROM AUTHOR]

Pure and Au incorporated WO3 thin films have been investigated for their sensing properties towards CO. Pure WO3 sensor film exhibited an increase in resistance while Au: WO3 films showed opposite behavior i.e. a decrease in resistance. We propose mechanism(s) for this anomalous sensing behavior of CO. [ABSTRACT FROM AUTHOR]

Gas sensing properties of pure and Au incorporated WO3 thin films towards H2S and Cl2 have been investigated. The sensor films were able to detect H2S and Cl2 selectively at an operating temperature of 150 and 200 °C, respectively. Effect of gas concentration and Au loading have been investigated and correlated with the observed sensitivity values. Pure WO3 films exhibited better sensing characteristics towards H2S (S = 17, 10 ppm, 150 °C) while sensor film containing Au thickness of 21.6 nm exhibited a maximum sensitivity towards Cl2 (S = 89, 10 ppm, 200 °C).. [ABSTRACT FROM AUTHOR]

Explains the importance of library and information systems in agricultural education, research and development. Points out the challenges offered to library executives by information explosion, developments in computer and communication technology, and information awareness. Opines that agricultural library systems in India as they exist now are not sustainable. They have to be totally recast and made more productive to the needs by application of modern management techniques. Discusses in detail the concept of sustainable library management, its functions, techniques, TQM, and Automated Management Information System for the library. Stresses that the success of the library system in an agricultural university depends on how appropriately it could conceive the university's information requirements and develop appropriate strategies for providing effective information, support to agricultural research, development and extension.