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681.
Precipitation scavenging coefficient: influence of measured aerosol and raindrop size distributions 总被引:2,自引:0,他引:2
Mihaela Mircea Sabina Stefan Sandro Fuzzi 《Atmospheric environment (Oxford, England : 1994)》2000,34(29-30)
Precipitation scavenging coefficients, widely used in pollution studies, are derived from microphysical parameterisations of aerosol particles and raindrop populations and parameterisations of their interactions. The present study investigates the effects of measured aerosol and raindrop size distributions in a microphysical polydisperse framework. The interactions between aerosol and raindrops parameterised as collision efficiency are explicitly included to account for Brownian diffusion, inertial impaction and interception. Estimated values of the polydisperse scavenging coefficients exhibit variations of orders of magnitude depending on the aerosol type and almost no variation with the raindrop size distributions. For practical use, linear relationships between the scavenging coefficients and rain intensity for different aerosol types are derived. 相似文献
682.
Richard Schuster Rachel Buxton Jeffrey O. Hanson Allison D. Binley Jeremy Pittman Vivitskaia Tulloch Frank A. La Sorte Patrick R. Roehrdanz Peter H. Verburg Amanda D. Rodewald Scott Wilson Hugh P. Possingham Joseph R. Bennett 《Conservation biology》2023,37(3):e14048
Protected areas are a key instrument for conservation. Despite this, they are vulnerable to risks associated with weak governance, land-use intensification, and climate change. We used a novel hierarchical optimization approach to identify priority areas for expanding the global protected area system that explicitly accounted for such risks while maximizing protection of all known terrestrial vertebrate species. To incorporate risk categories, we built on the minimum set problem, where the objective is to reach species distribution protection targets while accounting for 1 constraint, such as land cost or area. We expanded this approach to include multiple objectives accounting for risk in the problem formulation by treating each risk layer as a separate objective in the problem formulation. Reducing exposure to these risks required expanding the area of the global protected area system by 1.6% while still meeting conservation targets. Incorporating risks from weak governance drove the greatest changes in spatial priorities for protection, and incorporating risks from climate change required the largest increase (2.52%) in global protected area. Conserving wide-ranging species required countries with relatively strong governance to protect more land when they bordered nations with comparatively weak governance. Our results underscore the need for cross-jurisdictional coordination and demonstrate how risk can be efficiently incorporated into conservation planning. Planeación de las áreas protegidas para conservar la biodiversidad en un futuro incierto 相似文献
683.
The input of acidity to Swedish forest soils through forestry between 1955 and 2010 is compared with the acid input from atmospheric deposition. Depending on region, input of acidity from forestry was the minor part (25–45%) of the study period’s accumulated acid input but is now the dominating source (140–270 molc ha−1 year−1). The net uptake of cations due to the increase in standing forest biomass, ranged between 35 and 45% of the forestry related input of acidity while whole-tree harvesting, introduced in the late 1990s, contributed only marginally (< 2%). The geographical gradient in acid input is reflected in the proportion of acidified soils in Sweden but edaphic properties contribute to variations in acidification sensitivity. It is important to consider the acid input due to increases in standing forest biomass in acidification assessments since it is long-term and quantitatively important.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01540-y. 相似文献
684.
Medić Dragana V. Sokić Miroslav D. Nujkić Maja M. Đorđievski Stefan S. Milić Snežana M. Alagić Slađana Č. Antonijević Milan M. 《Journal of Material Cycles and Waste Management》2023,25(2):1008-1018
Journal of Material Cycles and Waste Management - To increase the degree of cobalt (Co) extraction, the process of the cathode material leaching was performed in a sulfuric acid (H2SO4) solution... 相似文献
685.
Gheorghe Maria Dragos-Nicolae Stefan 《Journal of Loss Prevention in the Process Industries》2010,23(1):112-126
The safety in operation of a fixed-bed catalytic reactor remains a sensitive issue when a highly exothermic reaction is conducted and various process development elements such as controllability, stability, risk, and economic aspects are considered. Several model-based methods are used to estimate the safe operating region limits. Nominal conditions are set to limit the hot spot in the tubular reactor and avoid excessive thermal sensitivity to variations in the process parameters. When the catalyst or its characteristics are changed, the operating conditions have to be adjusted accordingly. The safety problem becomes more important when the production optimization requires setting the nominal operating point in the vicinity of the safety limits. This paper investigates the advantages as well as the precautions that need to be taken when using a more sophisticated model-based global sensitivity criterion (MV of Morbidelli & Varma) to routinely update the runaway critical conditions when changes in the investigated system frequently occur. A concrete example is provided for the case of an industrial fixed-bed catalytic reactor for nitrobenzene hydrogenation in vapour-phase. The analysis points out the discrepancies in predicting the runaway boundaries for complex processes between precise sensitivity-based MV-method and shortcut methods, and the importance of accounting for parameter uncertainty for both evaluation of the confidence region around the runaway boundaries and for the optimal set-point location. The close connection between the operating risk limits and the process kinetics is also highlighted even if the reactor geometry and the main flow conditions are kept unchanged. 相似文献
686.
Rooney James P. K. Michalke Bernhard Geoghegan Gráinne Heverin Mark Bose-O’Reilly Stephan Hardiman Orla Rakete Stefan 《Environmental science and pollution research international》2022,29(50):75356-75364
Environmental Science and Pollution Research - Human biomonitoring studies are of increasing importance in regulatory toxicology; however, there is a paucity of human biomonitoring data for the... 相似文献
687.
Daniele Baisero PhD Richard Schuster PhD Andrew J. Plumptre PhD 《Conservation biology》2022,36(2):e13806
Irreplaceability is a concept used to describe how close a site is to being essential for achieving conservation targets. Current methods for measuring irreplaceability are based on representative combinations of sites, giving them an extrinsic nature and exponential computational requirements. Surrogate measures based on efficiency (complementarity) are often used as alternatives, but they were never intended for this purpose and do not measure irreplaceability. Current approaches used to estimate irreplaceability have key limitations. Some of these are a result of the tools used, but some are due to the nature of the current definition of irreplaceability. For irreplaceability to be stable and useful for conservation purposes and to resolve limitations, irreplaceability measures should adhere to five axioms; baseline coherence, monotonic responsiveness, proportional responsiveness, intrinsic stability, and bounded outputs. We designed a robust method for measuring a site's proximity to irreplaceability that adheres to these requirements and used it to develop the first systematic global map of irreplaceability based on data for terrestrial vertebrates (n = 29,837 species, >1 million grid cells). At least 3.5% of land surface was highly irreplaceable, and 47.6% of highly irreplaceable cells were contained in 12 countries. More generous thresholds of irreplaceability flag greater portions of land surface that would still be realistic to protect under current global objectives. Irreplaceable sites should form a critical component of any global conservation plan and should be part of the UN Convention on Biological Diversity's post2020 Global Biodiversity Framework strategy, forming part of the 30% protection by 2030 target that is gaining support. The reliable identification of irreplaceable sites will be crucial to halting extinctions. 相似文献