Search results for "Ethylene"
showing 10 items of 2589 documents
The trophic transfer of persistent pollutants (HCB, DDTs, PCBs) within polar marine food webs.
2017
Biomagnification (increase in contaminant concentrations at successively higher levels of trophic web), is a process that can transversally impair biodiversity and human health. Most research shows that biomagnification should be higher at poles with northern sites having a major tendency to biomagnify Persistent Organic Pollutants (POPs) through their marine food webs. We investigated the biomagnification degree into two marine trophic webs combining carbon and nitrogen stable isotopes and POP analyses. We showed that the Antarctic trophic web was more depleted than the sub-Arctic one and the differences highlighted for the basal part could explain the difference in length between them. Co…
HCB, p,p'-DDE and PCB ontogenetic transfer and magnification in bluefin tuna (Thunnus thynnus) from the Mediterranean Sea.
2007
The bluefin tuna, Thunnus thynnus (Linnaeus 1758), is biologically and economically important in the Atlantic--Mediterranean ecosystems. Bluefin tuna feed on diverse food items depending on their age, thus they occupy different trophic levels during their lifespan. Hexachlorobenzene (HCB), p,p'-DDE and polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants (POPs) in the Mediterranean basin. The relationship between stable isotopes of nitrogen (N) and the POP residue levels in tissues has recently increased knowledge on the link between the trophic levels and the contaminant accumulation. Trophic levels were estimated by using 15N/14N ratio (delta15N) and HCB, p,p'-DDE…
POLYMERIC MICELLES BASED ON A PHOSPHOLIPID/ POLYASPARTAMIDIC COPOLYMER FOR BECLOMETHASONE DIPROPIONATE DELIVERY TO THE LUNGS
2010
Reprocessing of polyethyleneterephthalate and characterisation of monopolymer blends of virgin and recycled polymers
1997
Recycling of polyethyleneterephthalate (PET from bottles is considered by changing both reprocessing machines and the effect of humidity. The rheological and mechanical properties of this recycled material remain very close to that of the virgin material provided that a careful drying is carried out before any melt operation. The reprocessing has been carried out mainly in view of the use of this secondary material in blends with virgin PET-monopolymer or homopolymer blends. Indeed, this use is a common industrial practice to reuse plastic scraps. Most monopolymer blends show properties between those of the two components but in some cases lower than those expected on the basis of an additi…