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11.
12.
Kasper AC Berselli GB Freitas BD Tenório JA Bernardes AM Veit HM 《Waste management (New York, N.Y.)》2011,31(12):2536-2545
The popularization of mobile phones, combined with a technological evolution, means a large number of scrap and obsolete equipment are discarded every year, thereby causing economic losses and environmental pollution. In the present study, the printed wiring boards scrap of mobile phones were characterized in order to recycle some of the device components, using techniques of mechanical processing, hydrometallurgy and electrometallurgy. The use of the techniques of mechanical processing (milling, particle size classification, magnetic and electrostatic separation) was an efficient alternative to obtain a concentrated fraction (mainly iron in the magnetic fraction and copper in the conductive fraction) and another fraction containing polymers and ceramics. At the end of mechanical processing, a concentrated fraction of metals could be obtained with an average concentration of 60% copper. This concentrated fraction in metals was dissolved in aqua regia and sent to electrowinning to recover 92% of the dissolved copper. The obtained cathodes have a copper content above 95%, which demonstrates the technical feasibility of recovery of copper using the techniques of mechanical processing, hydrometallurgy and electrometallurgy. 相似文献
13.
Interference competition is often due to kleptoparasitism (food stealing). In which case, the attack distance, the distance over which one animal attacks another in an attempt to steal food, determines to a large extent the competitor density range over which interference significantly affects the intake rate of foraging animals.We develop a simple model of kleptoparasitism containing three parameters: attack distance, the density of foraging animals and a single dimensionless parameter α which summarizes the non-geometrical aspects of the interference process. Dominant and subdominant animals are not considered separately. The model predicts that the average intake rate will decrease exponentially with animal density and that a measure of the strength of interference depends on attack distance squared.The simple model is compared with a much more detailed individual-based foraging model from the literature. Simulated average intake rates are indeed well approximated by an exponential decrease with competitor density. Also the measure of interference behaves in the way expected from the simple model. By explaining the shape of the relationship between intake rate and animal density, the simple model provides insight into the behaviour of the detailed behavioural model.Insight into the role of geometry is important in the interpretation of field results and in the further development of detailed foraging models. 相似文献
14.
15.
Bruno G. Lages Beatriz G. Fleury Ana M. C. Hovell Claudia M. Rezende Angelo C. Pinto Joel C. Creed 《Marine Biology》2012,159(7):1551-1559
Competition for space changes species’ distributions and community organization on tropical rocky shores, and the presence of secondary metabolites in the tissues of non-indigenous species may aid them in establishing and expanding their range through negative competitive interactions. The aim of this study was to describe the range of chemical substances produced by the non-indigenous cup corals Tubastraea coccinea and T. tagusensis and to test whether they varied in the field when the corals were placed in proximity to two local competitors. Cholest-5-en-3β-ol and 9-octadecanoic acid were two common secondary metabolites found in the tissues of Tubastraea. In the competition interaction experiment, necrosis was detected on the tissues of the coral Mussismilia hispida, and this species induced variation in sterol, alkaloid, and fatty acid production in Tubastraea tissues. In contrast, a sponge overgrew Tubastraea colonies. These results indicate that chemical defense may contribute to the ability of these non-indigenous corals to invade native communities. 相似文献
16.
Adriana Melo Jousilene de Sales Tavares Marianny de Assis Costa Renato Santana de Aguiar Gustavo Malinger Fabiana de Oliveira Melo Mariana Balbino da-Silva Bruno Luiz Fonseca Schamber-Reis Gabriela Gama Amilcar Tanuri Leila Chimelli Patricia Oliveira-Szejnfeld Melania M. Ramos de Amorim 《黑龙江环境通报》2020,40(13):1732-1740
17.
Pienkoß Fabian Abis Marco Bruno Martina Grönholm Raul Hoppe Michel Kuchta Kerstin Fiore Silvia Simon Franz-Georg 《Journal of Material Cycles and Waste Management》2022,24(1):364-377
Journal of Material Cycles and Waste Management - This work is aimed at exploring the recovery of heavy metals from the fine fraction of solid waste incineration bottom ash. For this study,... 相似文献
18.
Because of fast urban sprawl, land use competition, and the gap in available funds and needed funds, municipal decision makers
and planners are looking for more cost-effective and sustainable ways to improve their sewer infrastructure systems. The dominant
approaches have turned to planning the sanitary sewer systems within a regional context, while the decentralized and on-site/cluster
wastewater systems have not overcome the application barriers. But regionalization policy confers uncertainties and risks
upon cities while planning for future events. Following the philosophy of smart growth, this paper presents several optimal
expansion schemes for a fast-growing city in the US/Mexico borderlands—the city of Pharr in Texas under uncertainty. The waste
stream generated in Pharr is divided into three distinct sewer sheds within the city limit, including south region, central
region, and north region. The options available include routing the wastewater to a neighboring municipality (i.e., McAllen)
for treatment and reuse, expanding the existing wastewater treatment plant (WWTP) in the south sewer shed, and constructing
a new WWTP in the north sewer shed. Traditional deterministic least-cost optimization applied in the first stage can provide
a cost-effective and technology-based decision without respect to associated uncertainties system wide. As the model is primarily
driven by the fees charged for wastewater transfer, sensitivity analysis was emphasized by the inclusion of varying flat-rate
fees for adjustable transfer schemes before contracting process that may support the assessment of fiscal benefits to all
parties involved. Yet uncertainties might arise from wastewater generation, wastewater reuse, and cost increase in constructing
and operating the new wastewater treatment plant simultaneously. When dealing with multiple sources of uncertainty, the grey
mixed integer programming (GIP) model, formulated in the second stage, can further allow all sources of uncertainties to propagate
throughout the optimization context, simultaneously leading to determine a wealth of optimal decisions within a reasonable
range. Both models ran for three 5-year periods beginning in 2005 and ending in 2020. The dynamic outputs of this analysis
reflect the systematic concerns about integrative uncertainties within this decision analysis, which enable decision makers
and stakeholders to make all-inclusive decisions for sanitary sewer system expansion in an economically growing region. 相似文献
19.
20.
Goebes MD Hildemann LM Kujundzic E Hernandez M 《Journal of environmental monitoring : JEM》2007,9(6):599-609
Aspergillus is a genus of mold that has strong indoor sources, including several species capable of acting as opportunistic pathogens. Previous studies suggest that Aspergillus could serve as an indicator for abnormal mold growth or moisture, making it an important genus for environmental monitoring. Here, a quantitative polymerase chain reaction (qPCR, or real-time PCR) assay is presented for Aspergillus. The assay shows good specificity for the genus, detecting all Aspergillus species tested, although a few non-Aspergillus species are also amplified. Sensitivity testing demonstrates that DNA representing one conidium can be detected. A validation study compared qPCR results against direct microscopy counts using A. fumigatus conidia aerosolized into a laboratory chamber. The assay was then used to quantify Aspergillus in indoor air samples, demonstrating its utility for environmental monitoring. Analysis of a small number of clinical sputum samples showed complete agreement with culturing results. 相似文献