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401.
The catalytic activity of Pd catalysts supported on Ce0.73Tb0.27Ox/SiO2, Ce0.6Zr0.4Ox/SiO2, Ce0.73Tb0.27Ox/La2O3-Al2O3 and Ce0.6Zr0.4Ox/La2O3-Al2O3 was studied using the reduction of NO by CO. The catalysts were characterized by X-ray fluorescence, surface area, X-ray diffraction, temperature-programmed reduction, CO chemisorption and oxygen storage capacity. Temperature-programmed reduction results indicated that Tb or Zr incorporation improves the reducibility and oxygen storage capacity. CO chemisorption data suggested the presence of large PdO particles due to the low CO/Pd ratio. No significant differences were obtained in light off temperatures (TLight off) for all Pd catalysts and the most active was 1.5%Pd/Ce0.6Zr0.4Ox/SiO2. 相似文献
402.
Caitlin D. Kuempel Vivitskaia J. D. Tulloch Alyssa L. Giffin B. Alexander Simmons Valerie Hagger Carol Phua Ove Hoegh-Guldberg 《Conservation biology》2022,36(3):e13856
Conserving coral reefs is critical for maintaining marine biodiversity, protecting coastlines, and supporting livelihoods in many coastal communities. Climate change threatens coral reefs globally, but researchers have identified a portfolio of coral reefs (bioclimatic units [BCUs]) that are relatively less exposed to climate impacts and strongly connected to other coral reef systems. These reefs provide a proactive opportunity to secure a long-term future for coral reefs under climate change. To help guide local management efforts, we quantified marine cumulative human impact (CHI) from climate, marine, and land pressures (2013 and from 2008 to 2013) in BCUs and across countries tasked with BCU management. Additionally, we created a management index based on common management measures and policies for each pressure source (climate, marine, and land) to identify a country's intent and commitment to effectively manage these pressures. Twenty-two countries (79%) had increases in CHI from 2008 to 2013. Climate change pressures had the highest proportional contribution to CHI across all reefs and in all but one country (Singapore), but 18 BCUs (35%) and nine countries containing BCUs (32%) had relatively high land and marine impacts. There was a significant positive relationship between climate impact and the climate management index across countries (R2 = 0.43, p = 0.02), potentially signifying that countries with greater climate impacts are more committed to managing them. However, this trend was driven by climate management intent in Fiji and Bangladesh. Our results can be used to guide future fine-scale analyses, national policies, and local management decisions, and our management indices reveal areas where management components can be improved. Cost-effectively managing local pressures (e.g., fishing and nutrients) in BCUs is essential for building a climate-ready future that benefits coral reefs and people. 相似文献
403.
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405.
Meneses-Jácome Alexander Ruiz-Colorado Angela Adriana 《Environmental science and pollution research international》2021,28(4):4195-4208
Environmental Science and Pollution Research - The energy potential of high-organic loaded agro-industrial effluents receiving biological treatment is often neglected, particularly in emergent... 相似文献
406.
Maximilian Berthold Ulf Karsten Mario von Weber Alexander Bachor Rhena Schumann 《Ambio》2018,47(1):146-158
The EU-water framework directive aims at nutrient reductions, since anthropogenically induced eutrophication is a major threat for coastal waters. However, phytoplankton biomass in southern Baltic Sea coastal water bodies (CWB) remains high and the underlying mechanisms are not well understood. Therefore, a CWB data set was analysed regarding changes in phytoplankton biomass and nutrient concentration of nitrogen (N) and phosphorus (P) from 2000 to 2014. It was expected to find imbalances between produced phytoplankton biomass and total nutrient concentrations. Inner CWB were cyanobacteria-dominated and showed up to five times higher chlorophyll a-concentrations compared to outer CWB with similar total phosphorus-concentrations. Phytoplankton tended to be P-limited during spring and N-limited during summer. Phytoplankton biomass and nutrient concentrations were even higher during very humid years, which indicated a close coupling of the CWB with their catchment areas. This study suggests that re-mesotrophication efforts need to consider the importance of changed phytoplankton composition and nutrient availabilities. 相似文献
407.
Adrienne I. Greve Jim C. Loftis Juliane B. Brown Rob R. Buirgy Ben Alexander 《Journal of the American Water Resources Association》2003,39(6):1409-1418
ABSTRACT: In 1996, the Big Thompson Watershed Forum (BTWF) was formed “to assess and protect the quality of water” in the Big Thompson Watershed in northern Colorado. However, until 1999, water quality monitoring in the watershed was performed by many state, local, and federal agencies with no coordination among programs and with few efforts toward efficiency, data comparability, or information exchange. To better meet the needs of its stakeholders, the BTWF since 1999 has been actively pursuing the design and implementation of a cooperative water quality monitoring program. The program design involved consensus building among the funding participants, primarily drinking water providers. The final design included 38 parameters to be sampled 15 times per year at 24 stream and canal locations plus two reservoirs. Although the collaborative consensus based approach has been successful for the BTWF, this approach has its drawbacks; most notable among these are the time and labor this approach requires. Also, the BTWF struggled with achieving equal representation of all interests, since those agencies that provided funding had the greatest voice in the final product. While a collaborative approach may not always be best for monitoring program design, it should be appropriate for many watershed organizations that face the common problem of severe financial constraints. 相似文献
408.
Sven Adler Thomas Hübener Mirko Dreßler André F. Lotter N. John Anderson 《Journal of environmental management》2010,91(6):1380-1388
Relative species abundances are the most frequently applied data type used for modern or paleolimnological diatom studies. In contrast, plant ecologists save time by commonly using ordinal scale data (class data), where the abundance of a species is estimated using dominance classes, instead of relative abundance data. This study compares the performance of models based on ordinal diatom species class data (class 1: sporadic (<0–1%) up to class 6: dominant (>60%)) with similar model types based on relative abundance data for different regional training sets and sediment cores. First, relative diatom abundances were converted into ordinal classes. Species response to total phosphorous (TP) was modelled using both types of data - relative abundance and ordinal class data. Secondly, TP was reconstructed for six sediment cores from North-East Germany, Switzerland, and Denmark using WA and WA-PLS based on both types of data. Thirdly, 20 lake sediment surface samples with known relative diatom abundances and known water TP concentrations were recounted using an ordinal data scale to create an independent test set. No significant differences were found between relative abundance and class data for (1) explained species variance, (2) reconstructed TP values, and (3) inferred TP values of the 20 recounted samples. This approach demonstrates that past TP concentrations may also be reliably reconstructed using class data instead of relative diatom abundances. Thus, by using class data lake managers may not only obtain more long-term records past water quality, but this approach is also quicker and therefore more cost effective. Moreover, the findings of this study may also advance the use of automatic diatom identification with digital image recognition, as we demonstrate that not every damaged diatom valve needs to be identified. 相似文献
409.
Sudden Oak Death has been impacting California’s coastal forests for more than a decade. In that time, and in the absence
of a centrally organized and coordinated set of mandatory management actions for this disease in California’s wildlands and
open spaces, many local communities have initiated their own management programs. We present five case studies to explore
how local-level management has attempted to control this disease. From these case studies, we glean three lessons: connections
count, scale matters, and building capacity is crucial. These lessons may help management, research, and education planning
for future pest and disease outbreaks. 相似文献
410.
Alexander P. Economopoulos 《Waste management (New York, N.Y.)》2010,30(4):707-715
This paper considers selected treatment technologies for comingled domestic and similar wastes and provides technoeconomic data and information, useful for the development of strategic management plans. For this purpose, treatment technologies of interest are reviewed and representative flow diagrams, along with material and energy balances, are presented for the typical composition of wastes in Greece; possible difficulties in the use of treatment products, along with their management implications, are discussed, and; cost functions are developed, allowing assessment of the initial capital investment and annual operating costs. Based on the latter, cost functions are developed for predicting the normalized treatment costs of alternative methods (in €/t of MSW treated), as function of the quantity of MSW processed by plants built and operated (a) by municipality associations, and (b) by private enterprises. Finally, the alternative technologies considered are evaluated on the basis of their cost aspects, product utilization and compatibility with the EU waste framework Directive 2008/98. 相似文献