Effect of different organic materials on maize at different concentrations of lead.

The present study has been undertaken to know the effect of concentrations of lead (Pb) and different organic materials on the maize yield, concentrations of lead on maize plants and diethylene triamine penta-acetic acid (DTPA) extractable lead (Pb) on the post harvested soils. The results revealed that growth of maize increased by adding lead (Pb) upto 25 mg kg(-1) soil and thereafter the growth decreased. Application of organic matter increased the growth of maize in Pb-contaminated soil. With the increase in Pb concentration in soil, the concentration of Pb in plants also increased, however, application of organic material decreased Pb concentration in maize. The concentration of DTPA extractable lead (Pb) in post harvested soil samples significantly and consistently increased with increase in Pb. The addition of organic manure decreased the DTPA extractable Pb in soil which might be due to complexation/chelation of Pb with organic matter.

Biochemical methane potential of vegetable wastes.

Anaerobic digestion of vegetable waste slurry carried out in the laboratory using 2.5L capacity bottle reactors for 60 days at ambient temperature conditions resulted in a biogas yield of 0.391 L/g of VS fed. The methane content of the biogas generated from the reactors was in the range of 67%-70%. The biochemical methane potential obtained from the laboratory was 0.269 L CH4/g VS added.

Hydrochemical investigations and correlation--analysis of ground water quality of Jaipur city, Rajasthan (India).

The objective was to investigate the quality of drinking water of Jaipur city during pre-monsoon session (April 2006 to June 2006). Physico-chemical parameters like pH, EC, TDS, Ca2+, Mg2+, Na+, K+, CO3(2-), HCO3(-), Cl(-), SO4(2-), NO3(-), F(-) and TH were analyzed by adopting the standard method of APHA. To assess the quality of ground water, each parameter was compared with the standard desirable limit of that parameter stipulated for drinking water as prescribed by BIS. A correlation analysis was conducted to determine the correlation coefficient (r) among the parameters. The highest correlation was found between EC and chloride (r = 0.986, p = < .0001). EC showed highly significant positive correlation with chloride, Mg++, Na+, TDS and TH while significant inverse correlations were found in four cases, i.e. between pH and bicarbonate, between carbonate and bicarbonate, between pH and TDS and between sulphate and pH, while potassium, nitrate and fluoride did not show any significant correlations with any other parameters studied.

Physico-chemical characteristics and correlation, and regression study on ground water of Coimbatore north zone.

Ground water samples were collected from 18 wards of Coimbatore City north zone, among which 2 samples were collected from 2 different locations from each ward, total 36 samples: Water quality assessment was carried out for the parameters like temperature, odour, taste, colour, turbidity, pH, electrical conductivity, total dissolved solids, chlorides, hardness, alkalinity, calcium, sodium and potassium. Correlation coefficients were determined to identify the highly correlated and interrelated water quality parameters. Regression equations relating these identified correlated parameters were formulated. Comparison of observed and estimated values of the different parameters reveals that the regression equations developed in the study can be very well used for making water quality monitoring by observing the above said parameters alone. This provides an easy and rapid method of monitoring of water quality.

Comparative QSAR modeling of COX-2 inhibitor 1,2-diarylimidazoles using E-state and physicochemical parameters.

Considering importance of developing selective COX-2 inhibitors, COX-2 binding affinity data of 4-(2-aryl-1-imidazolyl)-phenyl methyl sulfones and sulfonamides (n = 83) have been modeled using electrotopological state (E-state) index as electronic parameter, hydrophobic substituent constant (pi) and molar refractivity (MR) of aryl ring substituents as lipophilic and steric parameters, respectively. Additionally, suitable dummy parameters have been used for the development of multiple regression equations in a stepwise manner. The study suggests that lipophilicity of ortho, meta and para substituents of the aryl ring increases the binding affinity, while molar refractivity (MR) of ortho and meta substituents of the aryl ring decreases the binding affinity. Again, electron-withdrawing substituents at meta and para positions of the aryl ring increase the binding affinity. Additionally, a 4-fluoro substituent on the aryl ring, a trifluoromethyl substituent at R position and simultaneous presence of 3-chloro and 4-methyl groups on the aryl ring are conducive to the binding affinity. Also, an amino substituent is preferred over a methyl group at R2 position suggesting preference of the sulfonamide moiety over the methyl sulfone moiety for the COX-2 binding affinity. Furthermore, importance of E-state values of different atoms in the generated relations suggests the influence of electron density distribution over the 1,2-diarylimidazole nucleus for the binding affinity. For this data set, E-state parameters perform better as electronic parameters in comparison to Hammett sigma parameters. When lipophilic whole molecular descriptor (ClogP) is used, instead of hydrophobic substituent constant (pi), the former performs better than the latter.

Effects of drop acceleration and deceleration on particle capture in a cross-flow gravity tower at intermediate drop Reynolds numbers.

Cross-flow gravity towers are particle scrubbing devices in which water is sprayed from the top into particle-laden flow moving horizontally. Models for predicting particle capture assume drops traveling at terminal velocity and potential flow (ReD > 1000) around it, however, Reynolds numbers in the intermediate range of 1 to 1000 are common in gravity towers. Drops are usually injected at velocities greater than their terminal velocities (as in nozzles) or from near rest (perforated tray) and they accelerate/decelerate to their terminal velocity in the tower. Also, the effects of intermediate drop Reynolds number on capture efficiency have been simulated for (a) drops at their terminal velocity and (b) drops accelerating/decelerating to their terminal velocity. Tower efficiency based on potential flow about the drop is 40%-50% greater than for 200 mm drops traveling at their terminal velocity. The corresponding values for 500 mm drops are about 10%-20%. The drop injection velocity is important operating parameter. Increase in tower efficiency by about 40% for particles smaller than 5 mm is observed for increase in injection velocity from 0 to 20 m/s for 200 and 500mm drops.