Search results for "Pollution"

TOXICITY INDUCED BY GADOLINIUM IONS ON DEVELOPING SEA URCHIN EMBRYOS

2016

Pharmaceuticals are a class of emerging environmental contaminants. Gadolinium (Gd) is a metal of the lanthanide series of the elements whose chelates are commonly employed as contrast agents for magnetic resonance imaging, and subsequently released into the aquatic environment. We investigated the effects of exposure to sublethal Gd concentrations on the development of four phylogenetically and geographically distant species: two Mediterranean species, Paracentrotus lividus and Arbacia lixula, and two species living in the East coast of Australia, Heliocidaris tuberculata and Centrostephanus rodgersii. Measures of the Gd and Ca content inside embryos by ICPMS showed a time- and dose-depend…

Innovative and Applied Research in Biology: Proceedings

2022

The collection contains SCIENTIFIC articles on the topics of the LU 80 conference reports. The main focus is on innovative and applied research in biology and interdisciplinary fields.

Pesticides in the Ebro River basin: Occurrence and risk assessment

2016

In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 2…

Effect of Sublethal Concentrations of Pesticides on the Feeding Behavior of Daphnia magna

1994

Daphnia magna was exposed to sublethal levels (1/4, 1/2, and 2/3 LC50 and LC50) of endosulfan and diazinon to determine the effect of these pesticides on filtration and ingestion rates. The experiments were performed with the unicellular algae Nannochloris oculata in a density of 5 x 10(5) cells/ml. Prior to these experiments, the acute toxicity of both pesticides was evaluated to calculate the LC50s. The 24-hr LC50 values were 0.62 mg/liter and 0.9 microgram/liter for endosulfan and diazinon, respectively. Rates of filtration and ingestion declined with increasing toxicant concentrations after a short exposure of 5 hr. The effective concentration at which feeding rates were reduced to 50% …

Organochlorinated pesticides in sediments from the Lake Albufera of Valencia (Spain).

2005

Bottom sediment samples from 121 sites of the Lake Albufera of Valencia were analyzed. Dieldrin, endrin, heptachlor and op'-DDT were not detected (0.01 ng g(-1)) in 88-93% of the sites. Aldrin and HCB concentration ranges were between0.01 and 0.1 ng g(-1) in 86% and 94% of the sites, respectively. Heptachlor-epoxide and lindane 95% confidence intervals were 0.2-0.5 and 0.06-0.12, respectively. The greatest average concentration corresponds to pp'-DDE, pp'-DDD and pp'-DDT. The sum of six isomers and derivatives of the DDT average concentration reaches 2.1 ng g(-1), as opposed to 2.7 ng g(-1) for the sum of 13 pesticides considered. In the site with a major contamination, 27.0 ng g(-1) of pp'…

Simultaneous clean up of fish fat containing low levels of residues and separation of PCB from chlorinated pesticides by thin-layer chromatography

1974

A fugacity model assessment of ibuprofen, diclofenac, carbamazepine, and their transformation product concentrations in an aquatic environment

2018

An updated version of FATEMOD, a multimedia fugacity model for environmental fate of organic chemicals, was set up to assess environmental behaviour of three pharmaceuticals in northern Lake Päijänne, Finland. Concentrations of ibuprofen, diclofenac, and carbamazepine were estimated at various depths at two sites: near a wastewater treatment plant and 3.5 km downstream the plant. When compared with environmental sampling data from corresponding depths and sites, the predicted concentrations, ranging from nanograms to hundreds of nanograms per litre, were found to be in good agreement. Weather data were utilised with the model to rationalise the effects of various environmental parameters on…

Structural characterization of Nigerian coals by X-ray diffraction, Raman and FTIR spectroscopy

2010

Abstract The structural parameters of six Nigerian coals were determined by X-ray diffraction, Raman and FTIR spectroscopy. This study reveals that the coals contain crystalline carbon of turbostratic structure with some amount of highly disordered amorphous carbon. The average lateral sizes ( L a ), stacking heights ( L c ) and interlayer spacing ( d 002 ) of the crystallite structures calculated from the X-ray intensities range from 16.47 to 25.70, 8.12 to 13.25 and 3.48 to 3.58 A, respectively. The L a values derived from the Raman spectra analyses using the classical linear relationship between 1/ L a and the D/G band ratio are higher (27.53–34.67 A) than values obtained from X-ray diff…

ASSESMENT OF TEMPERATURE POLARIZATION IN MEMBRANE DISTILLATION CHANNELS BY LIQUID CRYSTAL THERMOGRAPHY

2014

AbstractThe measurement of local temperature distributions within a membrane distillation (MD) channel is a crucial step for the optimization of the channel and spacer geometry. This information allows the estimation of temperature polarization phenomena, which can dramatically influence the thermal efficiency of the process and the optimal choice of the geometric configuration (net spacer features, channel size, etc.). In the present work, a recently presented experimental technique, based on the use of thermochromic liquid crystals and digital image analysis, has been employed in order to assess the temperature polarization phenomena. The local heat transfer coefficient distribution on th…

Il diritto come relazione comunicativa

2012

Da un punto di vista sociologico, il diritto può essere inteso come sistema informativo ed in particolare la norma non è altro che un atto di comunicazione, cioè un messaggio, avente particolari caratteristiche di descrittività e, in senso lato, di prescrittività. Un messaggio, cioè, che appare indirizzato a orientare azioni e aspettative d’azione. In questo senso, dunque, la norma conferisce senso e significato all’azione, in senso weberiano.