returning crop residues into the soil as a source of organic matter are an important source of copper and can play an important role in the soil fertility. in addition to the role of the organic matter in increasing the concentration of micronutrients in soil solution, attention should be also paid to the role of the kind and the quantity of the root’s exudates released in response to the incor...

A sensitive laser spectrometer, named IRIS (water isotope ratio infrared spectrometer), was developed for the in situ detection of the isotopic composition of water vapour in the upper troposphere and the lower stratosphere. Isotope ratio measurements can be used to quantify troposphere-stratosphere exchange, and to study the water chemistry in the stratosphere. IRIS is based on the technique o...

A general method of automated multidimensional fractionation has been developed. Its basic ingredients are: (a) cascade fractionation, i.e., the sequential fractionation of components obtained from each chromatographic dimension on the same or a different dimension, (b) on-line acquisition and processing of data at each stage in the fractionation procedure, (c) a method for determining the begi...

High precision oxygen three-isotope ratios were measured for four mineral phases (olivine, low-Ca and high-Ca pyroxene, and plagioclase) in equilibrated ordinary chondrites (EOC) using a secondary ion mass spectrometer. Eleven EOCs were studied that cover all groups (H, L, LL) and petrologic types (4, 5, 6), including S1-S4 shock stages, as well as unbrecciated and brecciated meteorites. SIMS a...

We report Li isotopic measurements in seawater derived waters discharged from geothermal wells, thermal and submarine springs located in volcanic island arc areas in Guadeloupe (the Bouillante geothermal field) and Martinique (Lamentin plain and the Diamant areas). The lithium isotopic signatures of the geothermal fluids collected from deep reservoirs are homogeneous for a given site. However, ...

Poly(vinyl acetate-co-vinyl alcohol) (PVA), well-known as emulsion stabilizers, are obtained by partial hydrolysis of poly(vinyl acetate) (PVAc). Their thermal cloud point fractionation was performed in aqueous medium between 40 and 75 °C. This fractionation was carried out in order to get an insight in the partition of the initially present nanogels in the different fractions. All the fraction...

Gases contained within near-surface marine sediments can be derived from multiple sources: shallow microbial activity, thermal cracking of organic matter and inorganic materials, or magmatic-mantle degassing. Each origin will display a distinctive hydrocarbon and non-hydrocarbon composition as well as compound-specific isotope signature and thus the interpretation of origin should be relatively...