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Nolasco Maria E. Lemos Viviane A. S. López Gina Soares Sandra A. Feitosa Johnny P. M. Araújo Bruno S. Ayala Alejandro P. de Azevedo Marleane M. F. Santos Francisco E. P. Cavalcante Rivelino M. 《Journal of Polymers and the Environment》2022,30(7):2862-2874
Journal of Polymers and the Environment - The aim of the present study was to perform morphological and chemical characterizations of microplastics (MPs) found in seawater samples from the coast of... 相似文献
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Shaohua Hu Jorn D. Herner Martin Shafer William Robertson James J. Schauer Harry Dwyer John Collins Tao Huai Alberto Ayala 《Atmospheric environment (Oxford, England : 1994)》2009,43(18):2950-2959
Emission factors for elemental metals were determined from several heavy-duty diesel vehicles (HDDV) of 1998–2007 vintage, operating with advanced PM and/or NOX emissions control retrofits on a heavy-duty chassis dynamometer, under steady state cruise, transient, and idle conditions. The emission control retrofits included diesel particulate filters (DPF): catalyzed and uncatalyzed, passive and active prototype vanadium- or zeolite-based selective catalytic reduction (SCR) systems, and a catalyzed DPF fitted on a hybrid diesel electric drive vehicle. The prototype SCR systems in combination with DPF retrofits are of particular interest because they represent the expected emissions controls for compliance with PM and NOX regulations in 2010. PM samples from a full-exhaust dilution tunnel were collected on bulk filters, and on a Personal Cascade Impactor Sampler (PCIS) for total and water-soluble elemental analysis. All the DPFs significantly reduced emissions of total trace elements (>85% and >95% for cruise and for the Urban Dynamometer Driving Schedule (UDDS), respectively). However, we observed differences in the post-retrofit metals emissions due to driving cycle effects (i.e., exhaust temperature) and type of retrofit. In general, the metals emissions over cruise conditions (which leads to higher exhaust temperatures) were substantially different from the emissions over a transient cycle or while idling. For instance, during cruise, we observed higher levels of platinum (1.1 ± 0.6–4.2 ± 3.6 ng km?1) for most of the retrofit-equipped vehicle tests compared to the baseline configuration (0.3 ± 0.1 ng km?1). The vanadium-based DPF + SCR vehicle during cruise operation exhibited emissions of vanadium (562 ± 265 ng km?1) and titanium (5841 ± 3050 ng km?1), suggesting the possible release of actual SCR wash-coat (V2O5/TiO2) from the catalyst under the higher temperatures characteristic of cruise operation. The vanadium emissions exhibited a bi-modal mass size distribution, with modes at <0.25 μm and 1.0–2.5 μm size ranges for the vanadium-based SCR system. For the DPF + SCR systems, a greater fraction of the metal emissions from the zeolite-based system is water-soluble compared to emissions from the vanadium-based system. 相似文献
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Harry Dwyer Alberto Ayala Sherry Zhang John Collins Tao Huai Jorn Herner Wilson Chau 《Atmospheric environment (Oxford, England : 1994)》2010,44(29):3469-3476
The California Air Resources Board, CARB, has participated in a program to quantify particulate matter (PM) emissions with a European methodology, which is known as the Particulate Measurement Programme (PMP). The essence of the PMP methodology is that the diesel PM from a Euro 4 vehicle equipped with a Diesel Particulate Filter (DPF) consists primarily of solid particles with a size range greater than 23 nm. The PMP testing and the enhanced testing performed by CARB have enabled an increased understanding of both the progress that has been made in PM reduction, and the future remaining challenges for new and improved DPF-equipped diesel vehicles. A comparison of measured regulated emissions and solid particle number emissions with the results obtained by the PMP participating international laboratories was a success, and CARB’s measurements and standard deviations compared well with the other laboratories. Enhanced measurements of the influence of vehicle conditioning prior to testing on PM mass and solid particle number results were performed, and some significant influences were discovered. For example, the influence of vehicle preconditioning on particle number results was significant for both the European and USA test driving cycles. However, the trends for the cycles were opposite with one cycle showing an increase and the other cycle showing a decrease in particle number emissions. If solid particle size distribution and total particle numbers are to be used as proposed in PMP, then a greater understanding of the quality and errors associated with measurement technologies is advisable.In general, particle counting instruments gave results with similar trends, but cycle-to-cycle testing variation was observed. Continuous measurements of particle number concentrations during test cycles have given detailed insight into PM generation. At the present time there is significant variation in the capabilities of the particle counting instruments in terms of particle size and concentration.Current measurements show the existence of a large number of volatile and semi-volatile particles of yet-to-be-resolved chemical composition in diesel exhaust, especially during DPF regeneration, and these particles are not included in the PMP methodology because they are smaller than 20 nm. It will be very challenging to improve our understanding of this class of diesel particulate matter. 相似文献
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Melissa S. Gerald James Ayala Angelina Ruíz-Lambides Corri Waitt Alexander Weiss 《Die Naturwissenschaften》2010,97(1):89-96
Several primate species show sexual dichromatism with males displaying conspicuous coloration of the pelage or skin. Studies
of scrotal coloration in male vervet monkeys (Chlorocebus aethiops) suggest that it is an important intrasexual signal, with relatively dark, colourful males dominating paler males. To date,
no studies have examined the influence of male colour on intersexual social interactions in vervet monkeys. The primary goal
of the present study was to evaluate whether female vervet monkeys attend to male coloration. We experimentally introduced
females, housed with either “pale” or “dark” males, to stimulus males whose scrota were pale, dark, or pale but painted to
look dark. Overall, during introductions, females did not differ in time spent directing affiliative behaviour toward pale,
dark, and painted males; however, females, permanently housed with dark males, spent significantly more time directing affiliative
behaviour toward pale than painted males. When the stimulus male was pale, affiliative exchanges between males and females
were longer than when the stimulus male was painted. Home male colour was not related to female-initiated aggression. Home
male colour was also not related to male-initiated aggression, although painted stimulus males were more likely to initiate
aggression than pale stimulus males. These findings lead us to conclude that females pay attention to male coloration, but
do not bias their interactions toward males solely on the basis of natural male coloration. 相似文献
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Irasema Alcntara‐Ayala 《Disasters》2019,43(Z1):S18-S27
LA RED (Network of Social Studies on the Prevention of Disasters in Latin America) has become the most influential group analysing disasters in Latin America and the Caribbean. Its contributions have paved the way for a new way of understanding disasters, disaster risk, and their management, concerning: (i) that disasters are not natural, but socially constructed; (ii) the inherent nexus between disaster risk, development, and the environment; (iii) the significance of small‐ and medium‐sized disasters and extensive and intensive risks; (iv) disaster risk management at the local level; and (v) integrated disaster risk research and the need for forensic investigations of disasters. As a result of this unification of challenges, intellectual communities of connected individuals were formed. Nonetheless, a focus on territorial management, exposure, and vulnerability remains a challenge for academia. In addition, the labyrinths of disaster risk governance must be disentangled by other stakeholders, such as national authorities, policymakers, and practitioners. 相似文献