NOPR Collection:

Performance evaluation of CALINE 4 dispersion model for an urban highway corridor in Delhi

2013-08-01T00:00:00Z

Title: Performance evaluation of CALINE 4 dispersion model for an urban highway corridor in Delhi Authors: Sharma, Niraj; Gulia, Sunil; Dhyani, Rajni; Singh, Anil Abstract: The paper focuses on the performance evaluation of CALINE 4 model for predicting carbon monoxide (CO) concentrations along an urban highway corridor passing through the city of Delhi. The model was applied using two different sets of Indian emission factors for different categories of vehicles specified by Central Pollution Control Board (CPCB), and Automotive Research Association of India (ARAI) in conjunction with on-site traffic and micro-meteorological inputs. The modelling results indicate that the dispersion of CO along the corridor was limited to a distance of ~150m from the edge of the mixing zone width (road width+3m on each side of the road). The concentrations were found to be 12% higher in the case of ARAI emission factors as compared to the CPCB emission factors. The correlation coefficient values (r²) between predicted and observed 1-hour concentrations for CPCB and ARAI emission factors were found to be 0.60 and 0.65 respectively. In addition, the estimated index of agreement (d) values of 0.86 and 0.85 respectively indicate satisfactory model performance. However, the estimated fractional bias (FB) values of 0.04 for CPCB and 0.06 for ARAI emission factors indicate that the CALINE 4 model under predicts the concentrations in both the cases. Page(s): 521-530

Experimental Investigation of Performance and Emission Characteristics of Coated Squish Piston in a CI Engine Fueled With Vegetable Oil

2013-08-01T00:00:00Z

Title: Experimental Investigation of Performance and Emission Characteristics of Coated Squish Piston in a CI Engine Fueled With Vegetable Oil Authors: Pachamuthu, Senthil Kumar; Azarudeen, P Mohamed; Prabhakar, S Abstract: In this study, the performance and emission characteristics of the CI engine using coated squish piston fueled with Jatropha oil is investigated experimentally. The obtained results were compared with the conventional piston. The test was conducted in single cylinder naturally aspirated water cooled direct injection diesel engine. The squish head and Partially Stabilized Zirconia coating was provided in the conventional piston bowl which helps in better turbulence, i.e., better mixing of air and fuel mixture resulting in improved combustion with the reduced emissions. Because of improved combustion, the peak cycle temperature in the combustion chamber increases. This increase in peak cycle temperature helps in better atomization and vaporization of the fuel used, i.e., Jatropha biodiesel. The increase in the combustion chamber temperature reduces the viscosity of the Jatropha biodiesel resulting in improved combustion. The performance and emission characteristics were improved much better with the squish piston when compared with the conventional piston. Improved brake thermal efficiency was obtained with the coated squish piston. Emissions like HC, CO and Smoke was considerably reduced with the coated squish piston. But in turn, NOX and CO₂ are increased due to the increase in peak cycle temperature inside the combustion chamber. Page(s): 515-520

Isolation, antifungal activity and characterization of soil actinomycetes

2013-08-01T00:00:00Z

Title: Isolation, antifungal activity and characterization of soil actinomycetes Authors: Saxena, Akansha; Upadhyay, Ramraj; Kumar, Dhaneshwar; Kango, Naveen Abstract: Actinomycetes were isolated from eight samples of two different habitats, i.e., garden soil and cultivated field soil. Isolation of actinomycetes was carried out on soil extract agar medium using serial dilution method and forty seven isolates were obtained. All these actinomycetes were then assessed for their antifungal activity against two fungal pathogens i.e., Candida albicans and Aspergillus niger by cross streak method. Eleven actinomycetes were found to inhibit A. niger. Out of 11 actinomycetes, only 6 showed antifungal activity against both test organisms. On the basis of screening, one potential actinomycete GS 22 was selected for further studies. The antibitiotic was extracted with methanol from cellular extract of actinomycete GS 22. The extract of GS 22 culture filtrate produced a clear zone of 27 mm against C. albicans by agar well diffusion method. Actinomycete strain GS 22 was further characterized on the basis of morphological, biochemical and physiological characteristics and identified using probabilistic identification of bacteria (PIBWin) software as Streptomyces phaeochromogenes. Page(s): 491-497

Design and performance evaluation of a novel biomass feeding system

2013-08-01T00:00:00Z

Title: Design and performance evaluation of a novel biomass feeding system Authors: Kalita, P; Nanibabu, G; Vivek, K P; Saha, U K; Mahanta, P Abstract: A novel feeding system has been designed and fabricated in order to provide an uniform and continuous flow of low bulk density biomass in a circulating fluidized bed (CFB) unit. The novel feeding system removes the difficulties associated with the various existing biomass feeding system such as bridge formation in the feeder and chocking. In the novel design, a hollow pipe with holes at its surface has been installed at the core of the hopper to provide the aeration effect. The experiments were carried out at four different inventories of 250, 500, 750 and 1000 gm and at three different sawdust particle sizes of mean diameter 732, 853 and 921 μm. Results of the experiment show that, the developed feeding system is suitable for supplying biomass without chocking to a CFB reactor to generate power for more than 5 kW-hr. Page(s): 511-514