Search results for " elements"
showing 10 items of 732 documents
Potentially toxic elements in fen peatland soils located near lignite-fired power plants in Central Poland
2021
Abstract The Grojec Valley (GV) peatland area in Central Poland is located close to lignite-fired power plants, which could be sources of potentially toxic elements (PTE). The aims of this study are: (1) to determine the effect of the lignite-fired power plants on soil pollution, (2) to evaluate pollution indices and magnetic susceptibility methods for determining the origin and distribution of PTE in soils, and (3) to demonstrate the importance of appropriate geochemical background (GB) selection for pollution studies in peatland soils. In order to comprehensively assess the soil pollution, four pollution indices (calculated using various types of GBs), and the mass-specific magnetic susce…
Major and trace element distribution in the peat from ombrotrophic bogs in Latvia.
2011
This study was undertaken to analyse major and trace elements and the nature of their accumulation in peat, with a particular emphasis on peat properties and the impact of local and regional pollution sources on the character of element accumulation in ombrotrophic bogs in Latvia. The element concentration values in peat from Latvia reflect the local processes that affect element concentrations in the peat mass, indicating accumulation of trace elements – apparently of anthropogenic origin (Pb, Cd, Co, Ni and others) – in the upper layers of the peat profiles. In addition, they indicate accumulation of several elements (for example, As, Cr and others) in deeper layers of bog, possibly due t…
Exploring a new incubation model for FinTechs: Regulatory sandboxes
2021
Research on incubation models indicates that incubators and accelerators are crucial catalysts for the development of start-ups. To facilitate start-ups in financial markets, several regulatory authorities have adopted a new incubation model called a ‘regulatory sandbox’. Regulatory sandboxes enable eligible applicants to test their technology-enabled financial solutions for a certain period of time (subject to conditions the regulator imposes). As such, these instruments allow innovation while preventing severe instability in financial markets caused by systemic risk. Despite their importance, management research has devoted little attention to studying how sandboxes operate as a new incub…
Modulation of Nrf2/ARE pathway by food polyphenols: a nutritional neuroprotective strategy for cognitive and neurodegenerative disorders
2011
In recent years, there has been a growing interest, supported by a large number of experimental and epidemi-ological studies, for the beneficial effects of some phenolic substances, contained in commonly used spices and herbs, in preventing various age-related pathologic conditions, ranging from cancer to neurodegenerative diseases. Although the exact mechanisms by which polyphenols promote these effects remain to be elucidated, several reports have shown their ability to stimulate a general xenobiotic response in the target cells, activating multiple defense genes. Data from our and other laboratories have previously demonstrated that curcumin, the yellow pigment of curry, strongly induces…
Material sources of the Roman brick-making industry in the I and II century A.D. from Regio IX, Regio XI and Alpes Cottiae
2015
International audience; Bricks, fine pottery, ceramic gears and tiles are among the human-made objects routinely recovered in archaeological documentation. Sites associated with early civilizations can provide thousands of samples from a single excavation. They come in endless varieties according to economic and social circumstances and, as debris can last almost forever, provide important clues about the past behaviours in human societies. Any information about the provenance of ceramics is highly valuable in archaeological analysis. In the case of Roman brick-making, the provenance and manufacture of clayey materials are usually interpreted only by studying stamps imprinted on the artefac…
Background element content in the lichen Pseudevernia furfuracea: a comparative analysis of digestion methods
2019
In bioaccumulation studies, the interpretation of pollutant contents in the target biomonitor has to be performed by assessing a deviation from an unaltered reference condition. A common strategy consists in the comparison with background element content (BEC) values, often built up by uncritically merging methodologically heterogeneous data. In this respect, the acid digestion of samples was identified as a major step affecting BEC data. Here, the analytical outcomes of two acid mixtures were compared on a set of matched paired samples of the lichen Pseudevernia furfuracea, a widely used biomonitor for which BEC values based on partial digestion were previously provided. The standard refer…
New Interpretative Scales for Lichen Bioaccumulation Data: The Italian Proposal
2019
The interpretation of lichen bioaccumulation data is of paramount importance in environmental forensics and decision-making processes. By implementing basic ideas underlying previous interpretative scales, new dimensionless, species-independent &ldquo
An overview on bounded elements in some partial algebraic structures
2015
The notion of bounded element is fundamental in the framework of the spectral theory. Before implanting a spectral theory in some algebraic or topological structure it is needed to establish which are its bounded elements. In this paper, we want to give an overview on bounded elements of some particular algebraic and topological structures, summarizing our most recent results on this matter.
Bounded elements in certain topological partial *-algebras
2011
We continue our study of topological partial *algebras, focusing our attention to the interplay between the various partial multiplications. The special case of partial *-algebras of operators is examined first, in particular the link between the strong and the weak multiplications, on one hand, and invariant positive sesquilinear (ips) forms, on the other. Then the analysis is extended to abstract topological partial *algebras, emphasizing the crucial role played by appropriate bounded elements, called $\M$-bounded. Finally, some remarks are made concerning representations in terms of the so-called partial GC*-algebras of operators.
Conflicting coccolithophore and geochemical evidence for productivity levels in the Eastern Mediterranean sapropel S1
2011
Abstract The cyclic development of anoxic conditions in the eastern Mediterranean deep sea waters is one of the most fascinating research topics in paleoceanographic studies. In combination with bottom water stagnation, enhanced primary production is a common explanation for the deposition of organic-rich layers (sapropels). This is supported by extensive evidence from both geochemical and micropaleontological studies. The correspondence of recent sapropel layers with peaks of the lower photic zone coccolithophore species Florisphaera profunda has been interpreted as a proxy for the development of a deep chlorophyll maximum (DCM), due to the pycnocline/nutricline shallowing into the lower p…