Search results for "feature"
showing 10 items of 4091 documents
Presence of polycyclic aromatic hydrocarbons in sediments and surface water from Shadegan wetland – Iran: A focus on source apportionment, human and …
2018
Abstract Polycyclic aromatic hydrocarbons (PAHs) contamination in aquatic system is of concern since it may constitute a sink of these contaminants for wetland ecosystem. We investigated pollution characteristics and ecological risks of PAHs by sampling contaminated sediments and water from the Shadegan wetland in Khuzestan province, south-west Iran. Concentrations of total PAHs in water and sediment samples varied from 42 ± 2.3–136 ± 7.5 ng/L and 10 ± 0.5–317 ± 14.3 µg/kg, respectively. Source apportionment of PAHs by both approaches (Principal component analysis-multiple linear regression (PCA-MLR) and molecular isomeric ratios of specific PAHs), indicated impact of potential anthropogeni…
Analysis of Mercury Pollution in Air in Urban Area of Riga Using Atomic Absorption Spectrometry
2015
Toxicity of mercury and its compounds is well known, and they are considered as substances of heightened concern. Though mercury is to some extent released into the environment by natural processes such as volcanic eruptions, additional releases from anthropogenic sources have increased the environmental exposure and deposition significantly. There are many commonly used items containing mercury, for instance, mercury light bulbs, switches, and mercury thermometers, the disposal of which into trashcans can cause an increase of mercury concentration in the air of the local area. The paper reports mercury pollution surveys performed in several districts of Riga (the capital of Latvia). Using …
Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling
2011
Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial survei…
Development of pipette tip-based poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolith for the extraction of drugs of abuse from oral flu…
2019
Abstract In this work, a monolithic polymer based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) was prepared inside 200 μL pipette tips for the extraction of drug of abuse from oral fluid samples. After an appropriate surface tip modification, several polymerization mixtures with different monomer/cross-linker ratios, and percentage of porogen were studied. The most appropriate monolith to easily flow organic solvents and oral fluid samples was prepared with a MAA/EDMA ratio of 8:92 wt/wt and dodecanol containing 10 wt% toluene, as porogenic solvent. Parameters affecting the extraction procedure were evaluated and the monolith was characterized in terms of bindin…
Distributed learning automata-based scheme for classification using novel pursuit scheme
2020
Learning Automata (LA) is a popular decision making mechanism to “determine the optimal action out of a set of allowable actions” (Agache and Oommen, IEEE Trans Syst Man Cybern-Part B Cybern 2002(6): 738–749, 2002). The distinguishing characteristic of automata-based learning is that the search for the optimising parameter vector is conducted in the space of probability distributions defined over the parameter space, rather than in the parameter space itself (Thathachar and Sastry, IEEE Trans Syst Man Cybern-Part B Cybern 32(6): 711–722, 2002). Recently, Goodwin and Yazidi pioneered the use of Ant Colony Optimisation (ACO) for solving classification problems (Goodwin and Yazidi 2016). In th…
Principal polynomial analysis for remote sensing data processing
2011
Inspired by the concept of Principal Curves, in this paper, we define Principal Polynomials as a non-linear generalization of Principal Components to overcome the conditional mean independence restriction of PCA. Principal Polynomials deform the straight Principal Components by minimizing the regression error (or variance) in the corresponding orthogonal subspaces. We propose to use a projection on a series of these polynomials to set a new nonlinear data representation: the Principal Polynomial Analysis (PPA). We prove that the dimensionality reduction error in PPA is always lower than in PCA. Lower truncation error and increased independence suggest that unsupervised PPA features can be b…
Dynamic Animal Populations in Managed Forests: Species Ecological Requirements and Sustainable Harvesting
2015
Forest management has altered forested environments and provoked stress to many natural habitats and biodiversity. The goal of biodiversity management is the long-term persistence of populations in human-modified environments. We demonstrate a spatio-temporal modeling approach to address the relationship between various management objectives and population persistence in the long-term in a commercial forest landscape. We used the flying squirrel (Pteromys volans), the three-toed woodpecker (Picoides tridactylus) and the long-tailed tit (Aegithalos caudatus) as example species. They are all forest species but they have distinctly different habitat requirements. In the model, forest growth, f…
Mercury uptake into poplar leaves
2016
International audience; Tailings dumps require mercury stabilization to prevent air pollution by evaporated mercury, which can be achieved through plant covers. Plants are considered a net sink for atmospheric Hg via incorporation into leaf tissues. However, most studies related to Hg uptake by plants have considered plants exposed to only atmospheric Hg, whereas in the case of tailings dumps, plants are potentially exposed to both soil and atmospheric Hg. The goal of this work is to evaluate the relative contributions of root and atmospheric pathways by growing poplar (Populus trichocarpa X Populus maximowiczii/var Skado) cuttings on either control or polluted substrates and under either n…
Determination of tocopherols in vegetable oils by CEC using methacrylate ester-based monolithic columns
2007
The separation and determination of tocopherols (Ts) in vegetable oils by CEC using methacrylate ester-based monolithic columns has been developed. The effects of pore size of the monolithic columns were studied, and the composition of mobile phase was optimized. The optimal pore size of the monolith was obtained with 12 wt% 1,4-butanediol in the polymerization mixture. Excellent resolution between tocopherols was achieved within 10 min analysis time with a 99:1 v/v MeOH-aqueous buffer containing 5 mM tris(hydroxymethyl)aminomethane at pH 8.0. The LODs were lower than 2.3 microg/mL, and interday and column-to-column reproducibilities at 25 microg/mL were better than 5.6%. Using a 93:7 v/v M…
Multi-objective DSE algorithms' evaluations on processor optimization
2013
Very complex micro-architectures, like complex superscalar/SMT or multicore systems, have lots of configurations. Exploring this huge design space and trying to optimize multiple objectives, like performance, power consumption and hardware complexity is a real challenge. In this paper, using the multi-objective design space exploration tool FADSE, we tried to optimize the hardware parameters of the complex superscalar Grid ALU Processor. We compared how different heuristic algorithms handle the DSE optimization. Three of these algorithms are taken from the jMetal library (NSGAII, SPEA2 and SMPSO) while the other two, CNSGAII and MOHC were implemented by us. We show that in this huge design …