Earthquake dynamics. Mapping pressurized volcanic fluids from induced crustal seismic velocity drops.

Volcanic eruptions are caused by the release of pressure that has accumulated due to hot volcanic fluids at depth. Here, we show that the extent of the regions affected by pressurized fluids can be imaged through the measurement of their response to transient stress perturbations. We used records of seismic noise from the Japanese Hi-net seismic network to measure the crustal seismic velocity changes below volcanic regions caused by the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake. We interpret coseismic crustal seismic velocity reductions as related to the mechanical weakening of the pressurized crust by the dynamic stress associated with the seismic waves. We suggest, therefore, that mapping seismic velocity susceptibility to dynamic stress perturbations can be used for the imaging and characterization of volcanic systems.

Coating of fertilizers by degradable polymers.

The conventional agriculture leads to some important pollution of ground water (particularly, by nitrates). The solution is the coating of fertilizers by degradable polymers. In this work, we have studied the water vapour and liquid diffusion through polymer films detached from their support. Therefore, we may classify polymers as a function of their properties like water vapour and liquid barrier. We may choose the best polymer(s) for coating.coated fertilizers by chosen polymer(s) with mechanical techniques such as fluidised bed and pan coating. Moreover, the electron microscopy used to see the quality of the wall has showed the presence of pores due to the rapid evaporation of solvent. A drying in air current and an annealing could be done to avoid this problem.followed the ions release of fertilizers immersed in distilled water by conductimetry. The more interesting result was obtained with fertilizers coated by polylactic acid. In effect, the total release reached three weeks.

Separation of enantiomers by packed capillary electrochromatography on a cellulose-based stationary phase.

Separation of enantiomers was performed by applying packed capillary electrochromatography (CEC). Fused-silica capillaries of different lengths with an inner diameter of 100 microm were packed with a cellulose derivative immobilized onto macroporous silica gel. Parameters such as content of modifier in the mobile phase, concentration and pH of the buffer were varied for a set of test capillaries to determine their influence on enantioselectivity. In packed CEC the highest influence on resolution of the test racemates was found by changing the acetonitrile content, while variation of the buffer concentration mostly affects the electroosmotic velocity. The performance of packed CEC and nano-LC was also compared. Packed CEC showed much better column efficiency and enantioselectivity under similar flow/electroosmotic velocity.