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Showing papers by "L. John Kennedy published in 2007"


Journal ArticleDOI
TL;DR: In this article, the adsorption behavior of phenol onto the porous carbon was studied by varying the parameters such as agitation time, phenol concentration, pH and temperature, and the results showed that the sorption process was found to be exothermic in nature.

206 citations


Journal ArticleDOI
TL;DR: Investigations were conducted in batch mode to study the adsorption behaviour of m-cresol on a porous carbon prepared from rice husk by varying the parameters such as agitation time, m- cresol concentration, pH, and temperature, and it was showed that the Adsorption decreased with increase in pH and temperature.

103 citations


Journal ArticleDOI
TL;DR: Investigations were carried out in batch modes for studying the immobilization behavior of polyphenol oxidase (PPO) on two different mesoporous activated carbon matrices and non-linear pseudo first order, pseudo second order and intraparticle diffusion models were evaluated to understand the mechanism of immobilization.

35 citations


Journal ArticleDOI
TL;DR: In this article, the effect of strontium addition on the CoAl 2 O 4 composites prepared by sol-gel technique was investigated for humidity sensing properties, and the results revealed that the sensitivity factor increased with an increase in the Strontium molar ratio.
Abstract: The effect of Sr addition on the CoAl 2 O 4 composites prepared by sol–gel technique was investigated for humidity sensing properties. X-ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy and nitrogen adsorption–desorption isotherm at 77 K was employed respectively to identify the structural phases, surface morphology, vibrational stretching frequencies and BET surface area of the composites. The composites were prepared with the addition of strontium of different molar ratios (0, 0.2, 0.4, 0.6, 0.8 and 1.0) to CoAl 2 O 4 and were labeled as CoSA1, CoSA2, CoSA3, CoSA4, CoSA5 and CoSA6, respectively. The samples sintered at 900 °C for 5 h, were subjected to dc resistance measurements as a function of relative humidity (RH) in the range 5–98% and the results revealed that the sensitivity factor increased with an increase in strontium molar ratio. Among the different strontium-added composites, CoSA5 possessed the highest humidity sensitivity of 56,000 while the pure composite CoSA1 possessed a low sensitivity of 14,000. The response and recovery characteristics of the maximum sensitivity sample CoSA5 were 120 and 70 s.

29 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used X-Ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy and nitrogen adsorption/desorption isotherms at 77 K to identify the structural phases, surface morphology, vibrational stretching frequencies and surface area of the composites.
Abstract: Strontium(II)-added BaAl2O4 composites prepared by sol–gel technique was investigated for humidity sensing properties. X-Ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy and nitrogen adsorption/desorption isotherms at 77 K were employed to identify the structural phases, surface morphology, vibrational stretching frequencies and BET surface area of the composites, respectively. The composites were prepared with the addition of Sr(II) of different molar ratios (0, 0.2, 0.4, 0.6, 0.8 and 1.0) to BaAl2O4 and were labeled as BaSA1, BaSA2, BaSA3, BaSA4, BaSA5 and BaSA6, respectively. The samples sintered at 900 ◦ C for 5 h were subjected to dc resistance measurements as a function of relative humidity (RH) in the range 5–98% and the results revealed that the sensitivity factor (Sf = R5%/R98% were the dc resistances at 5% and 98% RH) increased with an increase in strontium molar ratio. Among the different composites prepared, BaSA5 possessed the highest humidity sensitivity of Sf = 39,000, while the pure composite BaSA1 possessed a low sensitivity of Sf = 8700. The response and recovery characteristics of the maximum sensitivity sample BaSA5 were 120 and 50 s. © 2007 Elsevier B.V. All rights reserved.

25 citations


Journal ArticleDOI
TL;DR: Strontium(II) added NiAl2O4 composites prepared by sol-gel technique was utilized for the detection of benzene and toluene vapors in this article.

23 citations


Journal ArticleDOI
TL;DR: In this paper, a set of strontium-II-added ZnAl2O4 composites were analyzed by X-ray diffraction, scanning electron microscopy (SEM) and nitrogen adsorption/desorption isotherms at 77 K and studied for humidity sensing characteristics.
Abstract: Strontium(II)-added ZnAl2O4 composites prepared by a sol–gel method were characterised by X-ray diffraction, scanning electron microscopy (SEM) and nitrogen adsorption/desorption isotherms at 77 K and studied for humidity sensing characteristics. The composites were prepared with the addition of Sr(II) of different molar ratios (0, 0.2, 0.4, 0.6, 0.8 and 1.0) to ZnAl2O4 and were labeled as ZnSA1, ZnSA2, ZnSA3, ZnSA4, ZnSA5 and ZnSA6, respectively. The samples sintered at 900 °C for 5 h were subjected to dc resistance measurements as a function of relative humidity (RH) in the range of 5–98% and the results revealed that the humidity response (Sf = R5%/R98%; R5% and R98% were the dc resistances at 5 and 98% RH) increased with an increase in strontium molar ratio. Among the different composites prepared, ZnSA5 possessed the highest humidity response of Sf = 38,744, while the pure composite ZnSA1 possessed a low humidity response of Sf = 10,000. The response and recovery times of the most sensitive sample ZnSA5 were 120 and 50 s.

17 citations


Journal ArticleDOI
TL;DR: The focal theme of the present investigation was to use a chemo-autotrophic activated carbon oxidation (CAACO) system, an immobilized cell reactor using chemoautotrophs (Bacillus sp.) for the treatment of domestic wastewater.

8 citations


Journal ArticleDOI
TL;DR: Strontium(II)-added CaAl2O4 composites were investigated for the sensitive properties of volatile organic compounds (VOCs) like benzene, toluene, cyclohexane, hexane, and acetone as mentioned in this paper.
Abstract: Strontium(II)-added CaAl2O4 composites prepared by sol−gel technique were investigated for the sensitive properties of volatile organic compounds (VOCs) like benzene, toluene, cyclohexane, hexane, and acetone. X-ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy, and nitrogen adsorption/desorption isotherm at 77 K were employed, respectively, to identify the structural phases, surface morphology, vibrational stretching frequencies, and Brunauer−Emmett−Teller (BET) surface area of the composites. The composites were prepared with the molar ratios of Ca/Sr as (1.0:0.0−0.0:1.0), keeping the aluminum molar ratio as constant, and were labeled as CaSA1, CaSA2, CaSA3, CaSA4, CaSA5, and CaSA6, respectively. The samples, sintered at 900 °C for 5 h, were subjected to dc resistance measurements in the temperature range from 30 to 200 °C to study the VOC vapor-sensing characteristics. The results revealed that the sensitivity factor increased with an increase in temperature up to 150 °C and there...

6 citations