Search results for "Trace Element"

Trace element behavior in the fluidized bed gasification of solid recovered fuels

2013

Gasification of biomass and recycled fuels is of particular interest for the efficient production of power and heat. Trace elements present as impurities in the product gas should be removed very efficiently. The objective of this work has been to develop and test thermodynamic models for the reactions of trace elements with chlorine and sulfur in the gasification processes of recycled fuels. In particular, the chemical reactions of trace elements with main thermochemical conversion products, main ash components, and bed and sorbent material are implemented into the model. The possibilities of gas cleaning devices in condensing and removing the trace element compounds are studied by establi…

Tracking trace elements from soil to Lebanese bread and Populations Exposure

2021

In Lebanon, the agri-food industry represents 18% of the industrial sector and yet food safety remains a major problem. In this interdisciplinary thesis, we followed the Trace Elements (TEs) in the Lebanese white bread sector "from farm to fork" based on the reality on the ground, and on two links in the sector: (i) the geogenic or anthropogenic origin of TEs present in the soil and their transfer to the wheat grain, for which 10 plots cultivated in wheat, covering the diversity of soils, irrigation practices and anthropogenic environments of the central Bekaa were chosen ; (ii) the exposure of populations to TEs present in bread, for which a survey of consumption habits across Lebanon was …

Food and Environment: Trace Element Content of Hen Eggs from Different Housing Types

2013

AbstractEleven trace elements (Ba, Cu, Fe, Mn, Ni, Pb, Rb, Se, Sr, V, Zn) were quantitatively determined in hen egg samples collected from different poultry housing types (large-scale poultry farms, organic farms and domestic farms) over the territory of Latvia. Samples were wet digested and quantitatively analysed by total reflection X-ray fluorescence spectrometry (TXRF). The accuracy of analytical method was verified with analysis of certified reference material NCS ZC73017 (GSB-10)-Apple. The most variable range of concentrations and the highest content of elements were determined for hen egg samples derived from organic farms, while egg samples from domestic farms and poultry farms mos…

Nutrient intakes of children aged 1-2 years as a function of milk consumption, cows' milk or growing-up milk.

2012

AbstractObjectiveTo evaluate the nutritional adequacy of diets in early childhood as a function of milk intake, cows’ milk (CM) or growing-up milk (GUM).DesignFrom a cross-sectional food consumption survey, two groups of children aged 1–2 years were defined: Group CM fed exclusively on CM ≥ 250 ml/d and Group GUM fed on GUM ≥ 250 ml/d. Proportions of children at risk of nutrient excess or insufficiency were estimated relative to the French Recommended Daily Allowances, Estimated Average Requirements or Adequate Intakes.SettingParents participating in the survey were recruited from all regions of France by a polling organization. Distribution was adjusted to that of the French population.Sub…

Vitamin and Mineral Supplementation and Neuromuscular Recovery after a Running Race

2006

International audience; Purpose: This double-blind study investigated the effects of vitamin and mineral complex supplementation on the neuromuscular function of the knee-extensor muscles after a prolonged trail running race. Methods: Twenty-two well-trained endurance runners took either placebo (Pl group) or vitamins and minerals (Vm group) for 21 d before the race and for 2 d after the race. Maximal voluntary contractions (MVC) and surface EMG activity of the vastus lateralis (VL) muscle were recorded before (pre) and 1 h (post), 24 h (post 24) and 48 h (post 48) after the race. Central activation ratio (CAR), neural (M-wave), and contractile (muscular twitch) properties of the quadriceps…

Volcanic signature of volatile trace elements on atmospheric deposition at Mt. Etna, Italy

2009

Volcanic volatiles and aerosol emitted into the atmosphere ultimately fall on the Earth’s surface as wet or dry deposition, and they can influence the environment and the ecosystems at local and regional scales. Therefore, atmospheric deposition plays a key-role in the geochemical cycles, redistributing volcanogenic elements to the ground. For this reason, estimating the volcanogenic trace element fluxes from the atmosphere to the surface is necessary for a better knowledge of the environmental impact of the volcanic emissions. Nevertheless, from a literature review, we have recognized the scarcity of investigation on trace element deposition in the surroundings of active volcanoes. Here, w…

Impact of Volcanic Emissions on Trace Elements Contents Measured in Endemic Plants at Mt. Etna (Italy)

2011

TRACE ELEMENT BEHAVIOUR IN SEAWATER DURING PYROCLASTIC ETNA'S ACTIVITY IN 2001. CONCURRENT EFFECTS OF NUTRIENTS AND FORMATION OF ALTERATION MINERALS

2010

From July 13 2001 began the most intense Etna's eruptive activity in the last 300 years. While this phenomenon occurred the oceanographic cruise ANSIC 01 was carrying out. Therefore the unique opportunity is arisen to investigate the chemical effects on marine system of delivery of large amount of pyroclastic particles (about 1 g m-2) into seawater. Comparing collected trace element data with those analysed during the oceanographic cruise JUVENILE 99, carried out two years before, large enrichments in V, Cr, Mn, Fe, Co, Cu and Pb contents have been recognised and attributed to leaching of freshly-erupted volcanic ash. Further comparison between to-day and previous collected trace element da…

The Cycle of volcanogenic trace elements at Mt Etna (Italy): From volcanic emissions to atmospheric deposition

2009

Volcanogenic particulates and gases from Etna volcano (Italy)

2014

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity they may have important environmental impacts from the local to the global scale and they can severely affect the atmospheric and terrestrial environment also at timescales ranging from a few to million years. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. The aim of this study was to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Nine samples were coll…