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81.
The coarser (CPM) and respirable (RPM) fractions of aerosol loads collected in a time sequence, during the onset of winter season in Delhi region, were subjected to Principal Component Analysis (15 elemental variables, 39 samples); the absolute mass contributed by each identified source to the CPM and RPM was quantified by using Absolute Principal Component Score (APCS) and Positive Matrix Factorization (PMF) method. Interestingly, the mass contributed by the local crustal source (material) to both fractions manifested undulating periodic behavior, a dominating harmonic corresponding to 24-h period was detected by using Discrete Fourier Transform (DFT). The corresponding harmonics, of varying strengths, were also detected in the recorded meteorological factors: Planetary Boundary Layer (PBL), Surface Level Temperature (T), Surface Level Relative Humidity (RH) and Wind Speed (WS). The analysis of the respective harmonic strength within the CPM, RPM, and meteorological factors suggested that the undulation observed in both size fractions of aerosol load from the local crust was affected by the meteorological factors. The large proportion of undulating loads (CPM and RPM), explained by the dominating harmonic, was fully accounted for by the empirical relation involving the discrete coupling parameters, and the recorded meteorological factors: PBL, T, RH and WS. The analysis suggests that the magnitude and the direction (‘positive’ load increase and ‘negative’ the reverse) of coupled meteorological factors'(s) effect on ambient CPM, RPM load is determined by the phase difference between the harmonic explaining the aerosol fraction's load and the corresponding harmonic present in the respective meteorological factor. The absolute mass contributions arising from the identified sources (APCS and PMF) allowed us to calculate the baseline ambient concentrations of undulating CPM and RPM loads, in the region of this study, affected by meteorological factors only.  相似文献   
82.
Forest certification has emerged as a marketing tool for linking the good forest management practices with the environmentally conscious consumers. Its genesis can be attributed to the society’s concern for the social and environmental significance of forests. Forest management certification when coupled with the chain-of-custody certification; then, the supply chain stages for such forest products can carry an ecolabel. Non-timber forest products (NTFPs) are of socio-economic and cultural importance for the forest dwelling communities, particularly for the tropical countries like India. India is home to an amazing diversity of plants, with over 46,000 plant species recorded to occur there. NTFP’s availability, utilization, commercialization, exploitation, management practices, policies and tenure systems in different parts of India have high diversity and variability. There is concern, however, that collection methods for most of NTFP species are destructive and wild populations are declining as a result. Thus, the harvest of NTFPs is coming under increasing scrutiny from certification programmes, as it plays a key role in the sustainable management of forest resources and community benefit worldwide. Thus, the present research paper highlights the issues relevant to certification of NTFPs in India, based on more than a decadal experience in dealing with this subject at Indian Institute of Forest Management, Bhopal.  相似文献   
83.
Illicit trade in wildlife products is rapidly decimating many species across the globe. Such trade is often underestimated for wide‐ranging species until it is too late for the survival of their remaining populations. Policing this trade could be vastly improved if one could reliably determine geographic origins of illegal wildlife products and identify areas where greater enforcement is needed. Using DNA‐based assignment tests (i.e., samples are assigned to geographic locations), we addressed these factors for leopards (Panthera pardus) on the Indian subcontinent. We created geography‐specific allele frequencies from a genetic reference database of 173 leopards across India to infer geographic origins of DNA samples from 40 seized leopard skins. Sensitivity analyses of samples of known geographic origins and assignments of seized skins demonstrated robust assignments for Indian leopards. We found that confiscated pelts seized in small numbers were not necessarily from local leopards. The geographic footprint of large seizures appeared to be bigger than the cumulative footprint of several smaller seizures, indicating widespread leopard poaching across the subcontinent. Our seized samples had male‐biased sex ratios, especially the large seizures. From multiple seized sample assignments, we identified central India as a poaching hotspot for leopards. The techniques we applied can be used to identify origins of seized illegal wildlife products and trade routes at the subcontinent scale and beyond.  相似文献   
84.
Causes of salinity and plant manifestations to salt stress: a review   总被引:5,自引:0,他引:5  
Salinity in agricultutal terms is the excess of salts above the level plant require. Most often it poses constrains in the growth hence productivity of the category of plants called glycophytes, wherein falls major crops, therefore is a serious concern. It is often recognized as excess of sodium ions (sodicity) that imparts life threatening consequences in plant due to mal-textured soil hindered porosity and aeration leads to physiological water deficit. Mingling with other edaphic/environmental factors viz. precipitation, temperature, flooding, soil profile, water table exaggerates the catastrophe synergistically. Improper irrigations system, leaching fraction added with land clearing and deforestation have been marked as the major cause. The present review underlines the different sources of salinity stress and their physiological manifestations, toxicity responses alongwith tolerance in plants and management strategies in affected landscapes.  相似文献   
85.
Seeing the sustainability of rice-wheat cropping system (RWCS) of the Indo-Gangetic Plain, adequate crop nutrition in general and nitrogen (N) in particular holds the key to sound crop management. The excessive application or insufficient management of N means an economic loss to the farmer and may lead to yield penalties and environmental problems. Improving N management in consonance with other nutrients is much important to break yield plateaus as breeding for high yielding is not happening in recent years. Findings from farm survey are used to evaluate the on-farm N management practices in rice crop of the study area. The crop management practices (especially time of sowing/transplanting and irrigation requirement) and resource base of the farmers decided the N use pattern of the farmers. The N(Physical optimum) and N(economic optimum) exceeding the recommended levels revealed the apparent need for the revalidation of the existing recommendations. Paddy yield increased significantly within different rice types. This study generated comprehensive data on N use pattern in rice in the study area.  相似文献   
86.
Aluminum and its salts widely used in our daily life have been reported nephrotoxic to humans and animals following prolonged exposure. Therefore, the present study was made to examine the renoprotective role of Spirulina platensis against Al3+ and AlF3 in male Swiss albino mice. Exposure to these chemicals decreased feed and water intake, and body and kidney weights. Histology of kidney and their biochemistry were also markedly altered along with that of serum biochemistry. Spirulina not only minimize toxic effects of test chemicals but also favored faster recovery of treated mice after their withdrawal.  相似文献   
87.
This paper reports a regional contamination of the environment in central-east India that does not share geology or boundary with the Bengal Delta Plain. About 30,000 people residing in 30 villages and towns are directly exposed to arsenic and more than 200,000 people are "at risk." Complete geographical extent of this contamination is being established, and this newly reported contaminated area could be quite large. This paper further reports that the mechanisms involved in arsenic mobilisation are complex and the two theories of arsenic mobilisation, i.e., pyrite oxidation and oxyhydroxides reduction, do not fully explain the high levels of arsenic contamination. This paper also proposes the "oxidation-reduction theory" for arsenic mobilisation where the arsenic originates from the arsenopyrite oxidation and the arsenic thus mobilised forms the minerals and gets reduced underground in favourable Eh conditions. The stoppage of water withdrawal from the contaminated sources did not result in lowering of arsenic levels as expected according to the heavy groundwater extraction theory (pyrite oxidation theory). Cases of arsenicosis in the region are on the rise and the switchover to less contaminated water has not reversed the arsenicosis progression in the affected persons even after 2 years. Surface water of the rivers is also being contaminated because of the probable dislocation of contaminated groundwater due to the heavy rains in monsoon season, which indicates that the river water could be a major carrier of arsenic in dissolved or adsorbed forms that may be a cause of contamination of the delta plains.  相似文献   
88.
The proper disposal of discarded waste tires is becoming a serious matter of concern worldwide as huge proportion of this waste is being generated which makes the proper disposal virtually infeasible. About 1000 million of waste tires are discarded every year, and by the year 2030, it will turn up to 1200 million per year. If this enormous quantum of waste remains unattended, it would led to serious health and environmental problems. The investigation aims at appraising the compaction and strength characteristics of clayey soil incorporated with waste crumb rubber and cement for its sustainable use in geotechnical application. A series of unconfined compression strength and split tensile strength tests were carried out on clayey soil incorporated with two percentages of cement (3 and 6%) by weight and four percentages of crumb rubber (2.5, 5.0, 7.5, and 10.0%) by weight. Moreover, scanning electron microscope analysis was also carried out to get better intuition about the behaviour of the composite. Test results suggested that crumb rubber (up to 5%) could be mixed with uncemented/cemented clay soil with the congruent impression. The inclusion of discarded waste tires in cemented clay would be one of the congenial methods for the disposal of this waste as it substantially reduces the deleterious influence of waste tire disposal on human health and ecology.  相似文献   
89.
Environmental Science and Pollution Research - Reversible hydrogen storage in MgH2 under specified conditions is a possible way for the positive reception of hydrogen economy, in which the...  相似文献   
90.
Environmental Science and Pollution Research - In this study, we synthesized recyclable Fe3O4-functionalized MIL101(Fe) chitosan composite beads for the removal of tetracycline (TC), doxycycline...  相似文献   
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