Search results for "DFI"
showing 10 items of 128 documents
The impact of landfills on the air quality of towns: A simple heuristic model for the city of Palermo
2009
In this study, the landfill of Palermo, is investigated as a potential source of the unusual methane concentrations found in the urban context. The source for these pollution episodes is identified by means of a simple heuristic method. A cross-correlation analysis between wind data and methane concentration levels is also used to confirm the hypotheses formulated. Doppler Sound Detection And Ranging (SODAR) measurements are used to investigate the air masses dynamics at the landfill, in order to better support the adopted assumptions. This interpretative method can be adopted in the first assessment stages of the environmental site performance in order to single out the candidate pollution…
Spatial characterization of leachate plume using electrical resistivity tomography in a landfill composed of old and new cells (Belfort, France)
2016
International audience; Located near Belfort (France), the Etueffont landfill was in operation from 1976 to 2002 for the disposal and storage of domestic waste produced by 47,650 inhabitants. The site is comprised of the original landfill site called the old landfill (OL), in operation from 1976 to 1999, and a newer section known as the new cell (NC) which operated from 1999 to 2002. The objective of this study is to determine, using electrical resistivity tomography (ERT), the extent of the leachate plume from the OL and to monitor the efficiency of the liner of the NC. The entire Etueffont site was crisscrossed with 21 electrical profile lines which were traced in summer between 2009 and …
Effect of solid waste landfill organic pollutants on groundwater in three areas of Sicily (Italy) characterized by different vulnerability
2017
The aim of this study was to obtain information on the presence and levels of hazardous organic pollutants in groundwater located close to solid waste landfills. Eighty-two environmental contaminants, including 16 polycyclic aromatic hydrocarbons (PAHs), 20 volatile organic compounds (VOCs), 29 polychlorinated biphenyls (PCBs), 7 dioxins (polychlorinated dibenzo-p-dioxins, PCDDs) and 10 furans (polychlorinated dibenzofurans, PCDFs) were monitored in areas characterised by different geological environments surrounding three municipal solid waste landfills (Palermo, Siculiana and Ragusa) in Sicily (Italy) in three sampling campaigns. The total concentrations of the 16 PAHs were always below t…
Separate processing of “color” and “brightness” in goldfish
1991
Spectral sensitivity was measured under different adaptation levels using a behavioral training technique in which the fish had to discriminate between a dark test field and a test field illuminated with monochromatic light. Depending on which of the two test fields was used as training test field, two functions were obtained which differ (1) in absolute sensitivity and (2) in shape. When trained on the dark test field, the fish seems to discriminate on the basis of a "color" cue, but it uses a "brightness" cue when trained on the illuminated test field. This was concluded from measurements of wavelength discrimination. Under low levels of the adaptation light (1.5 and 0.2 lx instead of 20 …
Condition Assessment and Analysis of Bearing of Doubly Fed Wind Turbines Using Machine Learning Technique
2023
Condition monitoring of wind turbines is progressively increasing to maintain the continuity of clean energy supply to power grids. This issue is of great importance since it prevents wind turbines from failing and overheating, as most wind turbines with doubly fed induction generators (DFIG) are overheated due to faults in generator bearings. Bearing fault detection has become a main topic targeting the optimum operation, unscheduled downtime, and maintenance cost of turbine generators. Wind turbines are equipped with condition monitoring devices. However, effective and reliable fault detection still faces significant difficulties. As the majority of health monitoring techniques are primar…
In spermatozoa collected after pellet swim up, when total dna fragmentation is higher than 15%, the normal morphologically spermatozoa population sho…
2020
Study question: We investigated the DNA Fragmentation Index (DFI) in motile normal morphologically spermatozoa comparing samples with total DFI < 15% Vs ≥ 15% collected after pellet swim up Summary answer: In the case of DFI ≥15% the percentage of normal morphologically spermatozoa with fragmented DNA is significantly higher than the population with DFI < 15% What is known already: Intracytoplasmic sperm injection (ICSI) is widely used in the treatment of male infertility. Only morphologically normal spermatozoa are mainly used by embryologists to fertilize an oocyte. Different papers have reported that spermatozoa with apparently normal morphology may have DNA fragmentation. These ev…
New historical data for long-term swordfish ecological studies in the Mediterranean Sea
2021
Abstract. Management of marine fisheries and ecosystems is constrained by knowledge based on datasets with limited temporal coverage. Many populations and ecosystems were perturbed long before scientific investigations began. This situation is particularly acute for the largest and commercially most valuable species. We hypothesized that historical trap fishery records for bluefin tuna (Thunnus thynnus Linnaeus, 1758) could contain catch data and information for other, bycatch species, such as swordfish (Xiphias gladius Linnaeus, 1758). This species has a long history of exploitation and is presently overexploited, yet indicators of its status (biomass) used in fishery management only start…
The cork oak in the Mountains of Palermo (Italy): ecological insights from the south-eastern edge of its distribution range
2020
Abstract: The uneven presence of the cork oak (Quercus suber L.) within its distribution range is not only determined by its climatic requirements but also by specific edaphic needs. Although most of the natural populations thrive in acidic soils deriving from metamorphic or volcanic rock outcrops, some cork oak populations are found growing in soils deriving from calcareous bedrock, which are considered less suitable. We carried out a multidisciplinary investigation at the south eastern edge of the Q. suber distribution range (Mountains of Palermo, NW Sicily), including soil, floristic, and vegetation surveys, aimed at: (i) assessing the native or introduced origin of some peculiar cork oa…
Neglected fishery data sources as indicators of pre‐industrial ecological properties of Mediterranean swordfish ( Xiphias gladius , Xiphiidae)
2022
Management of fish populations and ecosystems suffers from data and knowledge gaps, particularly with respect to how humans and nature affect dynamics at multi-decadal and longer time scales. However, collection of new data which indicates population or ecosystem status is slow and expensive. Here we analyse c. 110 years of neglected fishery data for an overexploited top predator, swordfish, in the Mediterranean Sea. These data are available at scales of high time–space–biological resolution (i.e., sub-weekly, sub-regional sea; individual weights) and allow different ecological questions to be addressed than is possible with coarsely scaled data (e.g., annually resolved total catches aggreg…
Sequestering ability of landfill leachate towards toxic metal ions
2017
The great part of municipal solid wastes is worldwide stored in sanitary landfills. The interaction of organic and inorganic wastes with rainwater produces in the landfill a leachate of extremely variable composition. It depends on several variables such as the type of wastes, the age of landfill, the pH, the redox potential, etc [1-2]. Four are the recognized categories of pollutants in landfill leachate: inorganic macrocomponents, dissolved organic matter (DOM), heavy metals and xenobiotic organic compounds [3]. In particular, heavy metals (arsenic, cadmium, copper, lead, mercury, etc.) are usually present at concentration of few ppb and up to some ppm. A variable but consistent fraction …