Search results for "soufre"

Role of the AM interaction on S-uptake and S-starvation resistance in Medicago truncatula

2010

Sulphur is an essential macronutrient for plant growth, development, and response to various abiotic and biotic stresses due to its key role in the biosynthesis of many S-containing compounds. Sulphate represents a very small portion of soil S pull and it’s the only form that plant roots can uptake and mobilize through H+-dependent co-transport processes implying sulphate transporters. Unlike the other organically bound forms of S, sulphate is normally leached from soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge of plant sulphate transporters has been growing significantly in the last decades, little is still known about the effect of t…

Adsorption and diffusion study, in gazeous phase, of wine active molecules in cork

2010

During wine ageing, oxidation reactions occur and can lead to wine sensory defaults. The main factors involved in this phenomenon are oxygen and gas barrier properties of stoppers. During the last ten years, some studies investigated oxygen transfer during winemaking and wine storage. However, only few of them deal with the interactions between molecules and sealing materials. The material studied in this work is raw cork, without any treatment, neither washed nor surface treated (with paraffin or silicone). This Phd work focuses on mass transfer of some wine active molecules, in gas phase, through the cork. The selected molecules are water, ethanol, sulphur dioxide and oxygen. An adsorptio…

Vers des systèmes viticoles économes en pesticides

2022

L’utilisation de produits phytosanitaires (cuivre, soufre et produits de synthèses) est à ce jour le moyen de lutte le plus efficace pour garantir une vendange qualitative et quantitative (Pujol, 2017). Face aux préoccupations sociétales croissantes concernant l’impact des pesticides sur l’environnement et la santé, la viticulture se doit pourtant de réduire sa dépendance aux produits phytosanitaires. Une transition agroécologique est ainsi nécessaire et implique de changer les pratiques afin de parvenir à diminuer l’utilisation des produits phytosanitaires. Le réseau DEPHY-Ferme a été créé en 2010 afin d’initier et stimuler cette transition agroécologique et répondre aux enjeux ambitieux i…

Contribution and limitation of infrared spectroscopy technique to understand physisorption processes on MFI zeolites

2011

This manuscript is devoted to the study of adsorption processes by FTIR spectroscopy. The experimental results concern the adsorption of ethylene, trichloroethylene, tetrachloroethylene, sulfur hexafluoride or p-xylene on MFI zeolites, more especially on silicalite-1. The first step of the work was to develop a new experimental device and procedure in order to obtain reliable absorption infrared data and to improve results previously obtained by a prototype. The first main result is to characterize, maybe for the first time, the evolution of the spectrum of the adsorbent all during the adsorption process. Experiments reveal that the zeolite infrared spectrum undergoes strong modifications w…

Indicateurs pour l'évaluation de l'impact de produits phytosanitaires sur la composante microbienne de la qualité biologique des sols

2011

National audience

Impact d’une carence en soufre sur la composition protéique des graines d’une collection de pois (Pisum sp.)

2019

Le comportement du soufre et les conditions d'oxydoréduction dans les basaltes hydratés de l'Etna inférés par des inclusions vitreuses et des verres …

2017

Sulfur is an important volatile component of magmas that presents different oxidation states, depending on the redox conditions and on the phase of occurrence: in silicate melts it is typically dissolved as S⁶⁺ and/or S²⁻ , in the gas phase it occurs principally as SO₂ (S⁴⁺ ) and H₂S (S²⁻). Mount Etna, in which magmatic redox conditions are poorly constrained, is used as a case study to investigate sulfur behavior in hydrous basaltic magmas during magma differentiation and degassing. This research integrates the study of natural olivine-hosted melt inclusions with an experimental study on S solubility in hydrous alkali basalts at magmatic conditions.Experimental results suggest the importan…

Identification des fonctions microbiennes associées à la dégradation du soufre organique dans les sols par une approche de métaprotéomique

2009

National audience

Retinas of the Diurnal RodentArvicanthis ansorgeiAre Highly Resistant to Experimentally Induced Stress and Degeneration

2011

International audience; PURPOSE. Environmentally induced stress plays a significant role in retinal degeneration and blindness both in animals and in humans. Among such sources of stress, phototoxicity is well studied and has been shown to lead to photoreceptor-specific loss in a number of species. However, the vast majority of studies have been conducted in nocturnal, albino rod-dominant rat and mouse strains, and the pertinence of such findings to human pathology and cone loss is debatable. The authors examined retinal vulnerability to damage in the diurnal murid rodent Arvicanthis ansorgei, a pigmented species with a large number of cones. METHODS. The authors used established protocols …

High-resolution FTIR spectra analysis of sulfur dioxide isotopologues

2019

In this thesis we considered the spectral properties of the sulfur dioxide. The experimental FTIR spectra of numerous sulfur dioxide isotopologues, 32S16O2, 34S16O2, 32S18O2 and 32S16O18O, were first recorded in the regions of fundamental, «hot», combination and overtone bands. The wide variability of the experimental conditions gave possibility to observe and identify for the first time transitions be¬ longing to the following of ro-vibrational bands: 3v2, 3v2 - v2, 2v2 - v2 bands of 32S16O2; 2v2 - v2 band of 34S16O2; v1 + v2, v2 + v3, v1 + v3, 2v1, 2v3 bands of 32S18O2; v1, v3, 2v1, v1 + v3, 2v3 bands of 32S16O18O. The inverse spectroscopic problems were solved for the studied states with…