Search results for "heavy [dark matter]"
showing 10 items of 385 documents
Metals distribution in the organic and inorganic fractions of soil: A case study on soils from Sicily
2005
The content of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, has been determined in the organic and inorganic fraction of eight soil samples from Sicily. A modified type-Tessier sequential extraction procedure has been used to recognize metals in five different fractions categorised as follows: (a) exchangeable metals, (b) metals bound to carbonates, (c) metals bound to iron and manganese oxides, (d) metals bound to organic matter, and (e) metals in residual fraction. The mineralogical composition of soils samples was characterized by X-ray diffraction. Humic substances were extracted by means of an alkaline extraction procedure. It has been found that both the mineralogical composition and the di…
Determination of trace elements in gluten-free food for celiac people by ICP-MS
2014
Abstract This paper is the first analytical approach to the study of twenty heavy metals in the gluten-free foods for celiac people. Only the ICP-MS technique was used. One of the advantages about the use of ICP-MS for this characterization is the high sensitivity that improved the limits of quantification levels for some elements that are present at low quantities in some samples. The concentration values of As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn in seventeen gluten-free food samples are reported. The highest arsenic and molybdenum levels were measured in Rice noodle from China (0.088 and 0.47 mg kg − 1 , respectively). The highest concentrations of some metal…
A multi-criteria evaluation system for arable land resource assessment
2020
This study proposed a multi-criteria evaluation system for arable land resources by combining the soil integrated fertility index (IFI) with a soil cleanliness index (based on heavy metals and metalloid content). A total of 16 typical arable land units in Chongming District, China, were evaluated using the proposed evaluation system based on 104 collected soil samples in 16 towns. The comprehensive soil evaluation scores of arable lands in 16 towns were in the range of 90.7 to 99.2 with a mean of 96.2, indicating that the arable land in all 16 towns was at the level of excellent (≥ 90.0). Lower cleanliness indices had a significant impact on the final evaluation score. In comparison with si…
Influence of Heavy Metal Concentration on Chlorophyll Content in Pleurozium schreberi Mosses
2020
Abstract The aim of biomonitoring is assessment of environment condition. Biomonitoring studies with the use of mosses focus mainly on analytes accumulation and determining elements’ concentrations in the study area. It is often forgotten that a bioindicator should be alive during biomonitoring studies (which can be determined by, e.g., analysis of chlorophyll content). The objective of the carried out research was an assessment of the influence of selected heavy metals concentration: Ni, Cu, Zn, Cd and Pb accumulated by Pleurozium schreberi mosses during 3-month exposition within active biomonitoring, on their vitality, assessed by an analysis of a and b chlorophyll concentrations. The stu…
Cr(VI) sorption by intact and dehydrated Candida utilis cells in the presence of other metals
2002
This study examined the Cr(VI), Cu(II), Zn(II), Cd(II), Pb(II) sorption by intact and dehydrated Candida utilis cells. The anion [Cr2O7]2− and cation Me2+ sorption kinetics was investigated in both single- and dual-metal situations. Uptake of chromate anions occurred much more slowly singularly than with metal cations. A combination of Pb or Cu and chromate anions gave a synergistic effect for Cr(VI) sorption, but not Cd and Zn, which inhibited Cr(VI) sorption by dehydrated cells. The use of alcian blue to occupy maximum vacant adsorption sites on the cell surface unexpectedly did not influence further adsorption of Me2+. Metal uptake by C. utilis was 7 mg (135 μM) Cr, 23 mg (362 μM) Cu, 39…
Effect of pruning-derived biochar on heavy metals removal and water dynamics
2014
Biomass-derived biochar is considered as a promising heavy metal adsorbent, due to abundance of polar functional groups, such as carboxylic, hydroxyl, and amino groups, which are available for heavy metal removal. The aims of this study were to evaluate the effectiveness of an orchard pruning-derived biochar in removing some heavy metals (through the evaluation of isotherms) and to study water dynamics at the solid-liquid interface as affected by heavy metal adsorption (through an innovative nuclear magnetic resonance (NMR) relaxometry approach). Both isotherms and NMR spectra revealed that Pb and Cr showed a good affinity for the biochar surface (Pb > Cr), while Cu was less affine. Accordi…
Statistical characterisation of heavy metal contents inParacentrotus lividusfrom Mediterranean Sea
2014
This work focuses on the estimation of Hg, As, Cr, Ni, Cu, V, Cd and Pb by inductively coupled plasma mass spectrometry in 135 adult specimens of Paracentrotus lividus collected in different coastal areas of Sicily (Gela, Punta Secca, Ragusa (RG), Siracusa, Priolo, Catania, Messina, Milazzo, Brolo and Filicudi), in order to monitor the Mediterranean marine ecosystem by use of sea urchin as bioindicator. Moreover, the paper deals with the statistical classification of the tested samples according to the sampling area based on metal concentrations. The descriptive statistics findings were obtained and, a starting multivariate matrix was built. Data-sets were subjected to Kruskal-Wallis test t…
ELSA 2014 Cohort: Risk Factors Associated With Heavy Episodic Drinking Trajectories in Argentinean College Students
2020
Heavy episodic drinking (HED) is highly prevalent in college students. In Argentina, there is a notable lack of longitudinal studies examining drinking trajectories. The present study identified HED trajectories in Argentinean college students during the first 3 years of college (seven waves) and examined the association between risk factors for alcohol use and HED trajectories. The sample was composed of 1,240 college students [63.1% women, aged 18–25 years (M = 19.1 ± 1.7)] who completed at least three waves (the first data collection and ≥2 follow-ups). For 3 years, participants completed seven surveys that measured HED frequency, age of drinking onset, drunkenness occurrence, trait impu…
Coping with uncertainty in the assessment of atmospheric pollution with lichen transplants
2019
In the assessment of atmospheric deposition using lichen transplants, coping with uncertainty is mandatory in cases of environmental forensics, when understanding whether an area is polluted or not, or tracing a given pollution source is of paramount importance. In this article, we have suggested a method based on the calculation of exposed-to-control ratios of element concentrations and on the quantification of the overall uncertainty associated with such calculation, which proved to be very robust and can be applied in most cases using a minimum of three replicates. The method allowed the selection of significantly accumulated elements i.e. those polluting the site under study, as well as…
Functions of adolescent drinking in Finland and the Soviet Union
1987
The present study was conducted in Finland and the USSR (Estonia) with two birth cohorts (14 and 17 years old) and their parents. The subjects, 504 in Finland and 329 in Estonia, were drawn from urban and rural areas. 85% of the Estonian and 55% of the Finnish parents returned the questionnaire. The results supported the hypothesis that adolescent drinking is an age-related behaviour aimed at active coping efforts to adopt adult-like behaviour. In both countries abstinence decreased with age, and the use of alcohol was seen as behaviour which became acceptable at an older age than the age when the actual initiation occurred. However, the use of alcohol remained occasional through the ages o…