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841.
This paper describes a participatory multi-stakeholder impact assessment approach based on the concept of a value tree (VT), generated using the value focused thinking method (VFT) developed by Keeney (1992 Keeney, R. 1992. Value-focused thinking, Cambridge, MA: Harvard University Press.  [Google Scholar]). This approach allows stakeholders to specify impact parameters to be evaluated, which in the context of the VT, are organized as goals, objectives and alternatives. The approach is implemented in two phases: Phase I is designed to formulate stakeholders' collective VT following VFT concepts and the cognitive mapping method, and Phase II is a participatory valuation approach based on the VT formed in Phase I. The VT and the VFT concepts are adopted as tools to capture different stakeholders' values, goals and perceptions. The resulting VT is structured as a hierarchy between goals and objectives, and a network consisting of relationships, linkages and cross-impacts of the different alternatives and objectives. The hierarchy and network structure enables stakeholders to decompose complex assessment problem into ‘smaller’ units, which makes for easier and clearer assessment context, without ignoring linkages of the units or assessment elements. The second phase allows stakeholders to express their preferences with respect to each assessment element, through a voting system that ultimately leads to measures of importance or relative weights associated with each element. A modified Analytic Hierarchy Process (called Analytic Network Process) was used to distill relative weights from the voting results. Results obtained from a case study in a Zimbabwean community forest show that the proposed approach is easy to implement and can address questions about whether a project can lead to a positive change in attitudes, and whether the changes actually lead to a propensity to adopt alternatives that the project supports (e.g. conservation-oriented alternatives).  相似文献   
842.
843.
Distribution (seasonal and spatial) of aliphatic and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Chitrapuzha River, Cochin, India, was investigated using gas chromatography. Significantly high concentrations prevailed during the pre-monsoon season with the industrial zones of the river appearing to be hot spots with particularly elevated levels of the hydrocarbons. AHCs ranged between 7754 and 41,173?ng/g with an average of 25,256?ng/g, while total PAHs varied from 5046 to 33,087?ng/g. n-Alkane indices and PAH diagnostic ratios point to petroleum contamination in the sediments. The significance of PAHs in the sediments was explored using universally accepted interpretation tools. Observed levels of PAHs in sediments of Chitrapuzha are likely to cause adverse effects on biota.  相似文献   
844.
This study emphasizes on identification of source and accessing the spatial variation of dissolved heavy metals (Cu, Cd, Fe, Ni, Pb and Zn) in the rivers of Sundarban Biosphere Reserve India, the UNESCO world heritage site. ANOVA (Analysis of Variance), PCA (Principal Component Analysis) as well as FA (Factor Analysis) are used for assessing the significant difference in means of metals concentration among the sites and understanding the sources of these pollutants. Three principal components with cumulative variance of 32, 55, and 73 %, show that Pb, Ni and Cd are closely associated with each other indicating an anthropogenic origin of these metals. Heavy metal evaluation index (HEI) values indicate that areas close to densely populated sites are affected by elevated metals concentration due to anthropogenic activities. The ratio between the concentration of Cd, Ni and Pb in sites and the maximum respective permissible limit for these metals for conserved habitat is Log10 normalized to understand the threats of these pollutants over the distributaries of Sundarbans. Pb pollution is prevalent in the areas that rely on the fossil fuel-operated boats, for transport, whereas higher Cd concentration is found in the areas dependent on rechargeable batteries to meet their energy demand. So these anthropogenic activities and mal-practices may be responsible for the heavy metal pollution in this region. The study concludes that gradual increase in metal pollution in river water due to anthropogenic activities, particularly Pb and Cd, could have a negative impact on the conserved flora and fauna of this ecosystem.  相似文献   
845.
The Gulf of Kachchh is characterised by a strong tidal variation and the reef communities are capable of higher exposure time during negative tides. About 11 sites located along the Marine National Park (MNP) from west to east were studied for assessing the present status of live coral cover along with other life-form categories. In the present study, the maximum live coral cover was recorded in Pirotan Island, followed by Laku Point, Mithapur and Boriya reef. Multivariate analyses such as Principal Component Analysis and Correspondence Analysis supported that the contribution of live coral cover was more towards Pirotan Island whereas the contribution of coral species cover was more towards Laku Point. Bray-Curtis cluster analysis categorized all the study sites into four major clusters with 78 % similarity based on life-form categories. Among them, two clusters from western region (one forming site from Mithapur Reef to Lakku Point and another one forming from Ashaba Gugar Reef to Dabdaba Island), the third one combines the western and eastern regions (Boriya Reef to Kalubar Island), the fourth one comprises the eastern region (Narara Reef to Sikka), and one outlier Pirotan Island. Based on coral species cover, two major clusters with 55 % similarity were formed. Among them, one cluster was formed from Pirotan Island to Kalubar Island in the eastern side of MNP and the second one comprised the western region of MNP (Boriya Reef to Laku Point), and one outlier Mithapur Reef. Thirty one species of live corals belonging to 8 families and 18 genera were recorded in the Marine National Park itself during the study period.  相似文献   
846.
Nanotechnology is expected to have a beneficial influence on agriculture, food and environment, due to the unique properties of nanomaterials. However, little is known about their safety and potential toxicity. Here we review metal nanoparticles, nanometal oxides, carbon nanotubes, liposomes and dendrimers. We present the application of these nanomaterials in agriculture, food and environment for plant protection; disease treatment; packing materials; development of new tastes, textures and sensations; pathogen detection; and delivery systems. We discuss risk assessment of nanomaterials and toxicological impacts of nanomaterials on agriculture, food and environment. We then provide regulatory guidelines for the safer use of nanomaterials.  相似文献   
847.
Roughly one-third of the food produced in the world for human consumption every year, approximately 1.3 billion tonnes, gets lost or wasted, according to the Food and Agriculture Organization (FAO). There is therefore an urgent need for new methods to preserve food. Encapsulation using nanoemulsions is a powerful technique for the protection of food-grade ingredients including vitamins, lipids, antioxidants and antimicrobial agents. In general, nanoemulsion systems demonstrate superior characteristics over conventional emulsions. This is due to their smaller droplet size, transparent optical properties, higher physical stability against droplet destabilization factors and improved bioavailability of the entrapped active ingredients. In general, nanoemulsions have been prepared with different sizes of droplets. However, a droplet size higher than 200 nm is generally preferred for food applications. Here we review nanoemulsion compositions, types of active ingredients, applications in different types of food systems, toxicological and safety aspects, and future directions.  相似文献   
848.
Journal of Material Cycles and Waste Management - In this study, pyrolysis of agricultural residues, such as rice straw (RS), wheat straw (WS), and sugarcane bagasse (SB), was performed in a...  相似文献   
849.
Masto  R. E.  Singh  M. K.  Rout  T. K.  Kumar  A.  Kumar  S.  George  J.  Selvi  V. A.  Dutta  P.  Tripathi  R. C.  Srivastava  N. K. 《Environmental geochemistry and health》2019,41(5):1923-1937
Environmental Geochemistry and Health - Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal...  相似文献   
850.
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