Search results for "oceanic"

Impact of rocket exhaust plumes on atmospheric composition and climate – an overview

2013

Rockets are the only direct anthropogenic emission sources into the upper atmosphere. Gaseous rocket emissions include CO, N2, H2, H2O, and CO2, while solid rocket motors (SRM) additionally inject significant amounts of aluminum oxide (Al2O3) particles and gaseous chlorine species into the atmosphere. These emissions strongly perturb local at- mospheric trace gas and aerosol distributions. Here, the previous aircraft measurements in various rocket exhaust plumes including several large space shuttle launch vehicles are compiled. The observed changes of the lower stratospheric composition in the near field are summarized.

A particle based simulation model for glacier dynamics

2013

This publication is contribution number 22 of the Nordic Centre of Excellence SVALI, “Stability and Variations of Arctic Land Ice”, funded by the Nordic Top-level Research Initiative (TRI). The work has been supported by the SVALI project through the University of Lapland, Arctic Centre, and through the University Centre in Svalbard. Funding was also provided by the Conoco-Phillips and Lunding High North Research Program (CRIOS: Calving Rates and Impact on Society). A particle-based computer simulation model was developed for investigating the dynamics of glaciers. In the model, large ice bodies are made of discrete elastic particles which are bound together by massless elastic beams. These…

Third-harmonic generation in optical microfibers: From silica experiments to highly nonlinear glass prospects

2012

International audience; Using optical microfibers, phase matching between different propagation modes allows for third-harmonic generation (THG). After detailing the relevant phase matching conditions and overlap integrals, we provide a comparison between THG effective efficiencies in silica and tellurite glasses. We also explain the relatively easy, wideband, conversion that we observe experimentally in silica glass microfibers, from 155 mu m to the green, by the geometry of the tapering region.

AQUEOUS EXTRACTS FROM LEAVES AND RHIZOMES OF THE MARINE SEAGRASS POSIDONIA OCEANICA EXHIBIT ANTI-LIVER CANCER ABILITY IN VITRO

2022

In vitro effects of extracts from leaves and rhizomes of P.oceanica on HepG2 tumor cells

2023

Thin crust and exposed mantle control sulfide differentiation in slow-spreading ridge magmas

2017

Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties

2021

Abstract In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, c…

Effect of the crystallization on the phase transitions IV ⇐ III and IV ⇐ II of ammonium nitrate

1993

Abstract The solid state phase transition path of ammonium nitrate is influenced by the manner of crystallization. Slow crystallization from water gives ideal crystals, which behaved differently from crystals prepared by rapid crystallization from the melt.

Relationships between sediment physico-chemical characteristics and heavy metal bioaccumulation in Mediterranean soft-bottom macrophytes

2001

Abstract Concentrations of Hg, Cd, Pb and Zn in the two seagrasses ( Posidonia oceanica and Cymodocea nodosa ), green alga Caulerpa prolifera and sediment and some physico-chemical characteristics of the sediment (organic matter, fine fraction (particles Significant correlations between the concentrations of metals in the plants and sediment (alone or normalized with respect to the physico-chemical characteristics) were usually found for Hg and Zn. For Pb only C . prolifera fractions were correlated to the Pb content of the sediment. For Cd no significant correlations were obtained between the metal in the plants and sediment. The concentration factors of the metals in the plants with respe…

Holothuria tubulosa Gmelin 1791 (Holothuroidea, Echinodermata) enhances organic matter recycling in Posidonia oceanica meadows

2014

Abstract The role of Holothuria tubulosa in organic matter recycling of Posidonia oceanica detritus was estimated in a laboratory feeding experiment. The individual mean ingestion rate of seagrass detritus by holothurians was evaluated and carbon and nitrogen stable isotopes, carbon and nitrogen content and C:N ratio analyzed in H. tubulosa , P. oceanica detritus and surface sediment. Results showed that H. tubulosa is capable of ingesting from 30% to 100% of the detritus produced by P. oceanica meadows, depending on the holothurian density. Stable isotope analysis provided evidence for the assimilation of seagrass detritus by H. tubulosa as their signatures were compatible with 1 trophic l…