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591.
Priyadarshi Ruchir Khan Ajahar Ezati Parya Tammina Sai Kumar Priyadarshi Sunaina Bhattacharya Tanima Kim Jun Tae Rhim Jong-Whan 《Environmental Chemistry Letters》2023,21(3):1673-1699
Environmental Chemistry Letters - About 70 million tons of sulfur are produced yearly as a by-product of petroleum refining, and 10 millions are overproduced and accumulated, thus requiring... 相似文献
592.
Ishtiaq Muhammad Jehan Noor Khan Said Akbar Muhammad Said Saddique Umar Iftikhar Bushra Zahidullah 《Environmental science and pollution research international》2018,25(15):14666-14673
Environmental Science and Pollution Research - This study was aimed to investigate the potential harmful element (PHE) concentrations in coal dust and evaluate the human risk assessment and health... 相似文献
593.
The article draws attention towards the importance ofgreenbelts in attenuating gaseous pollutants andpresents the meteorological, physico-chemical,biological, and horticultural dimensions associatedwith effective greenbelt design.We have presented the gist of a system ofmethodologies, developed by us, for greenbelt design. A case study demonstrating the applicability of thesystem has been presented. 相似文献
594.
An assessment of air quality in the vicinity of a selected school has been carried out by monitoring the concentrations of primary pollutants. The results has shown that during the school hours, the measured pollutants emitted from the cars next to the selected school, such as CO and NO(2), are always under the allowable limits for Kuwaiti air quality standards. On the other hand, the concentrations of non methane hydrocarbon pollutant (nm-HC), some of which are considered to be cancergenic, are found to be above the Kuwaiti standard most of the times. A traffic counter is used to record the number of cars in the main road next to the school in 15 min intervals for 10 days during the monitoring period for air quality. Statistical analysis is performed to develop a relation for prediction of the necessary reduction in traffic, based on CO concentrations, during morning and afternoon periods on working days. A computer dispersion model (CALINE4) is also used to assess the CO concentrations based on recorded flow of traffic and emission inventory with the prevailing meteorological conditions existed at the specified time. After the validation of model, different scenarios have been evaluated to provide an acceptable solution to resolve the traffic congestion problem near the schools in the early morning hours with substantial reduction in pollution levels. The optimal solution for CO concentration reduction by managing smooth traffic flow is to reduce the traffic intensity by half in early morning and afternoon rush hours. The results of the predicted CO concentration in the vicinity of the school for the model and the statistical analysis has shown reduction of 30% and 42% respectively, for approximately 50% decrease in the car use. On the other hand the predicted CO concentration for the model and the statistics reached 24% and 33% respectively when 50% of students opted for buses instead of using private cars. 相似文献
595.
The accurate predictions of ground ozone concentrations are required for proper management, control, and making public warning strategies. Due to the difficulties in handling phenomenological models that are based on complex chemical reactions of ozone production, neural network models gained popularity in the last decade. These models also have some limitations due to problems of overfitting, local minima, and tuning of network parameters. In this study, the predictions of daily maximum ozone concentrations are attempted using support vector machines (SVMs). The comparison between the accuracy of SVM and neural network predictions is performed to evaluate their performance. For this, the daily maximum ozone concentration data observed during 2002–2004 at a site in Delhi is utilized. The models are developed using the available meteorological parameters. The results indicated the promising performance of SVM over neural networks in predicting daily maximum ozone concentrations. 相似文献
596.
Monitoring results for organochlorine pesticides in soil and water from selected obsolete pesticide stores in Pakistan 总被引:1,自引:0,他引:1
Karam Ahad Ashiq Mohammad Hizbullah Khan Iftikhar Ahmad Yousaf Hayat 《Environmental monitoring and assessment》2010,162(1-4):191-199
Seasonal changes in micromineral and macromineral concentrations in tissues of shrimp (Parapenaus longirostris) from Marmara Sea were measured for a 1-year period by using inductively coupled plasma mass spectrometer. The contents of investigated minerals in shrimp were found to be in the range of 0.374–0.716 mg/kg for Hg, 0.526–1.286 mg/kg for Se, 0.007–0.098 mg/kg for Cd, 0.197–0.230 mg/kg for Pb, 5.194–7.600 mg/kg for Cu, 11.090–17.707 mg/kg for Zn, 22.128–38.850 mg/kg for Al, 61.769–88.437 mg/kg for Fe, 0.262–0.368 mg/kg for As, 0.081–0.249 mg/kg for Co, 0.850–1.459 mg/kg for Mn, 0.316–0.507 mg/kg for Ni, 0.032–0.107 mg/kg for Sn, 1.262–1.502 mg/kg for Cr, 2,813.770–3,317.819 mg/kg for Na, 3,702.230–4,479.648 mg/kg for K, 495.782–650.280 mg/kg for Mg, 790.407–1,016.112 mg/kg for Ca, 2,685.873–3,657.658 mg/kg for P, and 0.454–0.942 mg/kg for I. The levels of Hg found in autumn were higher than maximum levels proposed by the European legislation. 相似文献
597.
Amin U. Khan 《Environmental monitoring and assessment》2010,168(1-4):121-131
This paper provides a framework for the managers to devise means to protect, restore, and maintain the remaining bi-species groves for sustainable management of fragile arid land ecosystem. At the moment, there is no information available about the structural and functional ecology of these dwindling remnants. The selection criteria for the classification of the groves are based on understanding the positive association between the two species, Prosopis cineraria and Salvadora oleoides, in terms of spatial pattern and morphological features. It was achieved by highlighting the attributes of the benchmark grove and classification of other groves in reference to it. The results clearly show that positive association in the groves is due to differences in the growth strategies of the two species in terms of above- and belowground biomass allocation and architecture. Most of the groves are in various stages of degradation, and anthropogenic interferences are the major determinant linked with the declining status of the groves. These activities affect the complimentary attributes of the bi-species groves, thus disturbing the characteristic structural features which contributed to the stability of this fragile landscape. 相似文献
598.
We examine the frequency of reciprocal exchanges of helping behavior in three red-cockaded woodpecker populations to determine
if such exchanges might constitute a significant fitness benefit of helping. Specifically, we determine how often helpers,
once they become breeders, are assisted by young they previously helped raise. The estimated frequencies of reciprocal exchange
of helping based on survival and status transition probabilities are low (2%). Observed frequencies of reciprocity are significantly
higher than estimated frequencies in two of the three populations studied, suggesting that male fledglings more often remain
on their natal territory as helpers if another helper is already present. High rates of retention of young males as helpers
on high-quality territories or preferential helping of kin, as well as preferential helping of former care-givers, might explain
this result. When the analysis is restricted to helpers unrelated to the young they help raise, which controls for preferential
helping of kin and largely eliminates effects of territory quality, empirical estimates of the frequency of reciprocity do
not differ from estimates calculated from population demography. We conclude that young males do not preferentially help former
care-givers and that reciprocal exchange of help is not an important factor in the evolution of helping behavior in the red-cockaded
woodpecker. In this species, all known benefits of helping behavior are indirect (i.e., derived through kin selection ) rather
than direct. We discuss the occurrence of unrelated helpers in this context.
Received: 10 August 1999 / Received in revised form: 13 February 2000 / Accepted: 19 February 2000 相似文献
599.
Shabnam Shahida Akbar Ali Muhammad Haleem Khan Muhammad Mufazzal Saeed 《Environmental monitoring and assessment》2013,185(2):1613-1626
In this work, spectrophotometer was used as a detector for the determination of uranium from water, biological, and ore samples with a flow injection system coupled with solid phase extraction. In order to promote the online preconcentration of uranium, a minicolumn packed with XAD-4 resin impregnated with nalidixic acid was utilized. The system operation was based on U(VI) ion retention at pH 6 in the minicolumn at flow rate of 15.2 mL min?1. The uranium complex was removed from the resin by 0.1 mol dm?3 HCl at flow rate of 3.2 mL min?1 and was mixed with arsenazo III solution (0.05 % solution in 0.1 mol dm?3 HCl, 3.2 mL min?1) and driven to flow through cell of spectrophotometer where its absorbance was measured at 651 nm. The influence of chemical (pH and HCl (as eluent and reagent medium) concentration) and flow (sample and eluent flow rate and preconcentration time) parameters that could affect the performance of the system as well as the possible interferents was investigated. At the optimum conditions for 60 s preconcentration time (15.2 mL of sample volume), the method presented a detection limit of 1.1 μg L?1, a relative standard deviation (RSD) of 0.8 % at 100 μg L?1, enrichment factor of 30, and a sample throughput of 42 h?1, whereas for 300 s of the preconcentration time (76 mL of sample volume), a detection limit of 0.22 μg L?1, a RSD of 1.32 % at 10 μg L?1, enrichment factor of 150, and a sampling frequency of 11 h?1 were reported. 相似文献
600.
Different multivariate statistical analysis such as, cluster analysis, principal component analysis, and multidimensional
scale plot were employed to evaluate the trophic status of water quality for four monitoring stations. The present study was
carried out to determine the physicochemical parameters of water and sediment characteristics of Pondicherry mangroves—southeast
coast of India, during September 2008–December 2010. Seasonal variations of different parameters investigated were as follows:
salinity (10.26–35.20 psu), dissolved oxygen (3.71–5.33 mg/L), pH (7.05–8.36), electrical conductivity (26.41–41.33 ms−1), sulfide (1.98–40.43 mg/L), sediment texture sand (39.54–87.31%), silt (9.89–32.97%), clay (3.06–31.20%), and organic matter
(0.94–4.64%). pH, temperature, salinity, sand, silt, clay, and organic matter indicated a correlation at P < 0.01. CA grouped the four seasons in to four groups (pre-monsoon, monsoon, post-monsoon, summer) and the sampling sites
in to three groups. PCA identified the spatial and temporal characteristics of trophic stations and showed that the water
quality was worse in stations 3 and 4 in the Pondicherry mangroves. 相似文献