Search results for " Dissolution"

Processi paleocarsici e geositi: il caso del “libeccio antico” nel distretto marmifero di Custonaci, Sicilia nord-occidentale

2016

Abstract The Upper Triassic strata that crops out along the northern slope of Monte Sparagio, in the Custonaci “marble” district in northwestern Sicily, show an extensive development of dissolution cavities with a very variable shape and dimensions. Several different types of dissolution morphologies can be differentiated from microkarst to giant caverns. The cavities are filled up by polychrome silts or calcite cements or, in the larger caverns, by collapse breccias. The matrix between the collapse breccias is a polychrome silt that gives rise to an attractive ornamental stone, quarried in the past with the name of “Libeccio Antico”. The diagenetic processes that have controlled the format…

Mine sinkhole in Siciliy: geomorphologic and environment hazard

2009

Preparation of drug-polymer composites by polymerization in supercritical carbon dioxide: a new method to increase the dissolution rate of bioactive …

2008

Effects of Dissolved Complexation on REE Fate During Interactions between Volcanic Ash and Coexisting Fluids

2013

AbstractThis work analyzes REE behavior during the delivery of volcanic ash into a marine system and highlights the effects induced by dissolved carbonate and humate complexes on REE release. Kinetic experiments were carried out during a 6-month period using a batch method approach. Results show that the highest degree of REE leaching occurs during the early stage. Altered phases that crystallize induce REE sorption and dissolved complexation towards surface complexation, concurrent processes that are enhanced by Y/Ho, La/Yb, and Ce/Ce* changes, whereas dissolved humates and carbonates influence the dissolution rate of ash and the dissolved REE behavior.

Graphical analysis of electrochemical impedance spectroscopy of two consecutive irreversible electron transfers. 2. Zinc anodic dissolution in acid m…

2006

The graphical analysis of the impedance plots is used in the study of the electrodic systems that take place through two consecutive single electron transfers. The zinc anodic dissolution is studied by using this procedure. The characteristic points easily allow us to explain and to simulate the impedance behavior of this electrodic system according to the steady-state potential and the roughness of the working electrode. The direct procedure for parametrical identification from the graphical analysis allows us to reduce the time needed for an impedance experiment. This graphical analysis is suggested for studying thin coated galvanized steels.

Correlationship between microscopic observations and electrochemical behaviour of different kind of galvanized steel.

2005

Zinc anodic dissolution has been studied according to the steel galvanized method by means of the electrochemical impedance spectroscopy (EIS) and microscopic observations. Relevant information on the galvanized method is provided by the analysis of experimental data. The galvanized method has no influence on the kinetics parameters of the zinc anodic dissolution process. The galvanized method only changes the surface texture of the working electrode. Thus, the EIS fitting allows to calculate the fractal dimension of the surface of the working electrode.

Synchronie entre l'offre et la demande dans le cycle des nutriments: apprendre des écosystèmes naturels pour construire des agrosystèmes durables

2023

Redesigning agrosystems with more ecological regulations can help feed a growing population, preserve soils for future productivity and reduce environmental impacts. However, guidelines for redesigning agrosystems from natural systems are limited. Reviewing the last knowledge of ecosystem functioning, we outlined four ecological systems synchronizing the supply of soluble nutrients by soil biota to fluctuating plant nutrient demand. This synchrony limits deficiencies and excesses of soluble nutrient, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. We detail how ecological systems promoting synchrony can be ins…

La loi n° 2006-728 du 23 juin 2006 et le pacte civil de solidarité

2006

International audience

La collection historique d’échantillons de sols de l’essai patrimonial des ‘42 parcelles’ (INRAE, Versailles) : une machine à remonter le temps...

2020

Following three previous papers (van Oort et al., 2016, 2017, 2020) dealing with current soil characteristics and geochemical budgets in surface horizons, as well as the impacts of fertilization in subsurface horizons in soils of INRAE’s long term bare fallow experiment (the 42-plots trial), we now present some chronological aspects of soil evolution at the soil’s surface since 1928. For that, we analyzed several series of about 15 samples from the historical sample archive for 10 representative treatments: fertilizers with acidifying effects (ammonium sulphate, ammonium phosphate), fertilizers with dispersive effects (sodium nitrate, sylvinite, and potassium chloride), superphosphate, amen…

Multicomponent solid dispersion a new generation of solid dispersion produced by spray-drying

2020

Abstract The term “multicomponent solid dispersion” is widely used in recent literature to describe solid formulations consisting of a special excipient's mixture and active molecules finely dispersed. However, this term has not yet been defined. In this review, we aimed to improve the definition of multicomponent solid dispersions as a new generation of solid dispersions capable to improve both formulation issues and the therapeutic effect of the final dosage form. As it is well-known the use of solid dispersions to improve drug dissolution rate and solubility, this review describes the field of solid dispersions as well as the formulation strategies available for their production. In part…