Hydrochemical profile for assessing the groundwater quality of Sambhar lake City and its Adjoining area

Quality assessment of water is essential to ensure sustainable safe use of it for drinking, agricultural, and industrial purposes. For the same purpose the study was conducted for the samples of water of Sambhar lake city and its adjoining areas. The standard methods of APHA were used to analysis 15 samples collected from hand pumps and tube wells of the specified area. The analytical results show higher concentration of total dissolved solids, electrical conductivity sodium, nitrate, sulfate, and fluoride, which indicate signs of deterioration but values of pH, calcium, magnesium, total hardness, and carbonate are within permissible limits as per WHO standards. From the Hill-piper trilinear diagram, it is observed that the majority of groundwater from sampling stations are sodium?Cpotassium?Cchloride?Csulfate type water. The values of sodium absorption ratio and electrical conductivity of the groundwater were plotted in the US salinity laboratory diagram for irrigation water. Only the one sample fall in C₃S₁ quality with high salinity hazard and low sodium hazard. Other samples fall in high salinity hazard and high sodium hazard. Chemical analysis of groundwater shows that mean concentration of cation is in order sodium > magnesium > calcium > potassium while for the anion it is chloride > bicarbonate > nitrate > sulfate.     

The role of positive affectivity in team effectiveness during crises

Organizational efforts to improve team effectiveness in crisis situations primarily have focused on team training initiatives and, to a lesser degree, on staffing teams with respect to members' ability, experience, and functional backgrounds. Largely neglected in these efforts is the emotional component of crises and, correspondingly, the notion of staffing teams with consideration for their affective makeup. To address this void, we examined the impact of team member dispositional positive affect (PA) on team crisis effectiveness and the role of felt negative emotion in transmitting that influence. A study of 21 nuclear power plant crews engaged in crisis training simulations revealed that homogeneity in PA, but not mean‐level PA, was associated with greater team effectiveness. Mediation analysis suggested that homogeneity in PA leads to greater team effectiveness by reducing the amount of negative emotions that team members experience during crises. Furthermore, homogeneity in PA compensated for lower mean‐level PA in predicting effectiveness. Discussion focuses on the implications of these findings for understanding and further exploring the importance of affective factors and especially team affective composition in team crisis performance. Copyright © 2012 John Wiley & Sons, Ltd.     

Workers’ Perceptions of Workplace Safety and Job Satisfaction

A lot of attention has beenfocused on workers ‘ perceptions of workplace safety but relatively little or no research has been done on the impact of job satisfaction on safety climate. This study investigated this relationship. It also examined the relationships between job satisfaction and workers’ compliance with safety management policies and accident frequency. A positive association was found between job satisfaction and safety climate. Workers who expressed more satisfaction at their posts had positive perceptions of safety climate. Correspondingly, they were more committed to safety management policies and consequently registered a lower rate of accident involvement. The results were thus consistent with the notion that workers ‘ positive perceptions of organisational climate influence their perceptions of safety at the workplace. The findings, which have implications in the work environment, are discussed.     

Managing Forests for Increased Regional Water Yield in the Southeastern U.S. Coastal Plain

With growing populations fueling increased groundwater abstraction and forecasts of greater water scarcity in the southeastern United States, identifying land management strategies that enhance water availability will be vital to maintaining hydrologic resources and protecting natural systems. Management of forested uplands for lower basal area, currently a priority for habitat improvement on public lands, may also increase water yield through decreased evapotranspiration (ET). To explore this hypothesis, we synthesized studies of precipitation and ET in coastal plain pine stands to develop a statistical model of water yield as a function of management strategy, stand structure, and ecosystem water use. This model allowed us to estimate changes in water yield in response to varying management strategies across spatial scales from the individual stand to a regional watershed. Results suggest that slash pine stands managed at lower basal areas can have up to 64% more cumulative water yield over a 25‐year rotation compared to systems managed for high‐density timber production, with the greatest increases in stands also managed for recurrent understory fire. Although there are important uncertainties in the magnitude of additional water yield and its final destination (i.e., surface water bodies vs. groundwater), this analysis highlights the potential for management activities on public and private timber lands to partially offset increasing demand on surface and groundwater resources.     

Simulated marine respirometry of biodegradable polymers

Eleven microorganisms were isolated from several temperate marine locations in the northeast Altantic coast of the United States and one tropical location in the Pacific Ocean (Hawaii) for the purpose of developing a rapid and accurate method of screening biodegradable materials for their susceptibility to mineralization. The materials evaluated in this study included chemically modified starch, amylose and pullulan, poly(3-hydroxybutyrate-co-valerate), (PHB/V), cellulose acetate, and a modified lignin/styrene. Some of the soluble, unmodified, biologically produced substrates such as starch, pullulan, and amylose mineralized rapidly. In general, the synthetic, insoluble polymers and the chemically modified polymers, such as acetylated and chlorinated amylose and pullulan, mineralized more slowly, although the ultimate mineralization of some of the substituted polysaccharides equaled or exceeded that of the unmodified substrate. The insoluble bacterial polyester, PHB/V, degraded rapidly after a short induction period. Initial respiration rate data, in general, could not be used as a predictor of ultimate mineralization. It was found that the cumulative level of carbon dioxide evolved signifies the minimum extent of biodegradation of the substrate, and the oxygen consumed is a good indicator of the maximum extent of substrate degradation.Paper presented at the Biodegradable Materials and Packaging Conference, September 22–23, 1993, Natick, Massachusetts.     

δ15N and δ13C values in dental collagen as a proxy for age- and sex-related variation in foraging strategies of California sea lions

We assessed the foraging habits of California sea lions, Zalophus californianus, from Isla Santa Margarita, BCS, Mexico, by analyzing δ¹³C and δ¹⁵N values of dentin collagen. Since dentin is deposited annually in growth layer groups (GLGs), it can be subsampled to construct ontogenetic isotopic profiles at the individual level. We drilled 20 canine teeth and obtained 141 samples for isotopic analysis that were assigned to age-specific categories from GLG-based estimated ages. Pups’ GLGs had the highest mean δ¹⁵N values and the lowest mean δ¹³C values, a pattern likely driven by the consumption of milk. Juveniles had δ¹⁵N values between those of pups and adult females, which may reflect continued nursing into the second year or preferential consumption of coastal benthic versus pelagic prey. Significant differences were observed between the sexes of adults; adult females had lower mean δ¹³C and δ¹⁵N values than adult males. Higher isotope values in adult males relative to females may reflect a higher trophic position, but differences in foraging grounds cannot be excluded as a potential explanation because tracking data are not available at this time. Evidence of intra-specific foraging diversification may be related to a strategy to reduce competition within and among age and sex categories.     

Modeled response of ozone to electricity generation emissions in the northeastern United States using three sensitivity techniques

Electrical generation units (EGUs) are important sources of nitrogen oxides (NO_x) that contribute to ozone air pollution. A dynamic management system can anticipate high ozone and dispatch EGU generation on a daily basis to attempt to avoid violations, temporarily scaling back or shutting down EGUs that most influence the high ozone while compensating for that generation elsewhere. Here we investigate the contributions of NO_x from individual EGUs to high daily ozone, with the goal of informing the design of a dynamic management system. In particular, we illustrate the use of three sensitivity techniques in air quality models—brute force, decoupled direct method (DDM), and higher-order DDM—to quantify the sensitivity of high ozone to NO_x emissions from 80 individual EGUs. We model two episodes with high ozone in the region around Pittsburgh, PA, on August 4 and 13, 2005, showing that the contribution of 80 EGUs to 8-hr daily maximum ozone ranges from 1 to >5 ppb at particular locations. At these locations and on the two high ozone days, shutting down power plants roughly 1.5 days before the 8-hr ozone violation causes greater ozone reductions than 1 full day before; however, the benefits of shutting down roughly 2 days before the high ozone are modest compared with 1.5 days. Using DDM, we find that six EGUs are responsible for >65% of the total EGU ozone contribution at locations of interest; in some locations, a single EGU is responsible for most of the contribution. Considering ozone sensitivities for all 80 EGUs, DDM performs well compared with a brute-force simulation with a small normalized mean bias (–0.20), while this bias is reduced when using the higher-order DDM (–0.10).

Implications: Dynamic management of electrical generation has the potential to meet daily ozone air quality standards at low cost. We show that dynamic management can be effective at reducing ozone, as EGU contributions are important and as the number of EGUs that contribute to high ozone in a given location is small (<6). For two high ozone days and seven geographic regions, EGUs would best be shut down or their production scaled back roughly 1.5 days before the forecasted exceedance. Including online sensitivity techniques in an air quality forecasting model can provide timely and useful information on which EGUs would be most beneficial to shut down or scale back temporarily.     

Sorption kinetics and leachability of heavy metal from the contaminated soil amended with immobilizing agent (humus soil and hydroxyapatite)

Release of heavy metals onto the soil as a result of agricultural and industrial activities may pose a serious threat to the environment. This study investigated the kinetics of sorption of heavy metals on the non-humus soil amended with (1:3) humus soil and 1% hydroxyapatite used for in situ immobilization and leachability of heavy metals from these soils. For this, a batch equilibrium experiment was performed to evaluate metal sorption in the presence of 0.05 M KNO(3) background electrolyte solutions. The Langmuir isotherms applied for sorption studies showed that the amount of metal sorbed on the amended soil decreased in the order of Pb(2+)>Zn(2+)>Cd(2+). The data suggested the possibility of immobilization of Pb due to sorption process and immobilization of Zn and Cd by other processes like co-precipitation and ion exchange. The sorption kinetics data showed the pseudo-second-order reaction kinetics rather than pseudo-first-order kinetics. Leachability study was performed at various pHs (ranging from 3 to 10). Leachability rate was slowest for the Pb(2+) followed by Zn(2+) and Cd(2+). Out of the metal adsorbed on the soil only 6.1-21.6% of Pb, 7.3-39% of Zn and 9.3-44.3% of Cd leached out from the amended soil.     

Biodegradation of Polyaromatics Synthesized by Peroxidase-Catalyzed Free-Radical Polymerization

Polymers formed from peroxidase-based free-radical polymerization reactions were characterized for rates of mineralization against lignin and humic acid controls. Degradation studies were carried out in soil systems over 202 days and cumulative net CO₂ was determined. Whereas mineralization of the humic acid and alkali lignin controls totaled ca. 20% at the end of the test exposure, there was essentially no net mineralization of the hydrolytic lignin control. Mineralization of the test samples totaled 5% for poly(p-ethylphenol) and 11% for poly(m-cresol). At the same time, mineralization of the poly(p-phenyl phenol) totaled 64%. Conversely, the readily biodegradable polymers cellulose and PHB reached values of 91 to 97% in less than 60 days. Our data suggest that the mineralization kinetics of the enzymatically derived polyaromatics mimic those of the naturally occurring heteropolymers.