Papers published on a yearly basis
Papers
More filters
••
TL;DR: Deposition is modeled as a first order reaction on the Darcy scale for porous media which are statistically homogeneous and the influence of the correlation of the initial porosity field is studied.
Abstract: Deposition is modeled as a first order reaction on the Darcy scale for porous media which are statistically homogeneous. An elementary analytical solution is derived. A parametric study was done with a three-dimensional code which is briefly described and checked in media where the solution is known. The role of the parameters, including the artificial ones, is discussed with an illustrative example. When the Damkohler number is small, deposition causes smooth changes to the porosity field; the evolution of porosity is well described by the analytical solution. Very different results are obtained for large Damkohler numbers. The influence of the correlation of the initial porosity field is studied.
27 citations
••
TL;DR: In this article, it was shown that Cs, where in close proximity to BOs of Q4 species, promotes the polarizability of tetrahedra and these primed Q4-p species produce a strong Q4 signal.
27 citations
••
TL;DR: In this article, sediment fingerprinting approaches quantified the source of radiocesium contaminated sediment in the Mano and Niida coastal catchments were used to determine the contribution of upstream, more contaminated areas to sediment transiting the more densely populated coastal plain.
27 citations
••
TL;DR: Soufriere volcano is an andesite explosive volcano located in Guadeloupe in the lesser Antilles arc as discussed by the authors, and it has been reported that about 1400 earthquakes were recorded between May and December 1992.
Abstract: Soufriere volcano is an andesite explosive volcano located in Guadeloupe in the lesser Antilles arc. Since the last magmatic eruption dated 1440 ± 40 AD several violent phreatic eruptions have occurred. The two last 1956 and 1976-1977 phreatic/phreato magmatic eruptions were preceded by several decades of quietness. During these quiet periods, hydrothermalization and argillization are expanding due to high tropical rainfalls (10 to 12 m per year). Sealing of fractures yields more and more difficult the release of thermal stresses developed by the magmatic body supposed to be at 6 km depth. Overpressures are increasing in confined superficial water tables. Renew of seismic activity started in May 1992. About 1400 earthquakes were recorded between May and December 1992. The onset of activity was preceded, one year before, by a slight increase of vapor emission inside South crater located on Soufriere dome at the upper end of August 30, 1976 fault, by the reactivation of the small Tarade hot spring dried up since the 1976-1977 eruption, and by the appearance of a new, low flow rate, hot spring called Pas du Roy (about 30°C). A Self Potential (S.P.) survey has been performed in July 1992 on Soufriere massif. The S.P. anomalies evidence structural heterogeneities and ground waters flowing within the massif. A large, smooth, positive S.P. anomaly, composed of two localized and pronounced anomalous zones, is spreading on the south-west-south-east sector of the dome basis. The larger anomalous zone is located on Morne Mitan in the axis of the regional Ty and August, 30, 1976 faults. This zone is extending along the contact zone between Soufriere dome and Carmichael cone. The 1992 survey is compared with 1987 survey. Soufriere dome is now submitted to a ring of positive S.P. anomalies which are lying along the inner part of Amic crater. The positive anomalous zone located on Morne Mitan has developed since 1987. The second anomalous zone, located on the south-west part of the dome, was not observed in 1987. The amplitude reaches 200 mV. The S.P. mapping points out that warm ground water beneath the south part of the volcano summit, along clayey beds, could generate the collapse of the south-west-south-east sector of Soufriere dome.
27 citations
••
TL;DR: In this article, trapped holes located on Al-O-Al bonds in kaolinite were studied by electron paramagnetic resonance spectroscopy at 9.3 and 35 GHz applied to well-crystallized, X-ray irradiated and oriented samples.
Abstract: Trapped holes located on Al-O-Al bonds in kaolinite were studied by electron paramagnetic resonance spectroscopy (EPR) at 9.3 and 35 GHz applied to well-crystallized, X-ray irradiated and oriented samples. The Q-band EPR spectrum is characterized by three clearly separated groups of 11 quasi-equidistant superhyperfine lines centered at gxx=2.040±0.0005, gyy=2.020±0.0005 and gzz=2.002±0.001. In each of these groups, the 11 superhyperfine lines exhibit intensities according to the ratios 1∶2∶3∶4∶5∶6∶5∶4∶3∶2∶1. An angular dependence of the Q-band EPR spectrum with respect to the magnetic field is demonstrated by measurements on oriented films of kaolinite. An appropriate numerical treatment of the EPR spectra is described, which allowed extraction of the SuperHyperfine Structures (SHFS). X-and Q-band spectra have also been simulated. It is concluded from these experiments that only one type of center is present. This center, labelled the B-center in the literature, is very probably a hole trapped on oxygen (O- center) atoms coupled to two octahedral aluminium.
27 citations
Authors
Showing all 903 results
Name | H-index | Papers | Citations |
---|---|---|---|
Claude J. Allègre | 106 | 327 | 35092 |
Paul Tapponnier | 99 | 294 | 42855 |
Francesco Mauri | 85 | 352 | 69332 |
Barbara Romanowicz | 67 | 284 | 14950 |
Geoffrey C. P. King | 64 | 157 | 17177 |
Yi-Gang Xu | 64 | 271 | 14292 |
Jérôme Gaillardet | 63 | 199 | 14878 |
François Guyot | 61 | 292 | 12444 |
Georges Calas | 60 | 266 | 10901 |
Ari P. Seitsonen | 59 | 212 | 45684 |
Michele Lazzeri | 58 | 140 | 57079 |
Bernard Bourdon | 58 | 118 | 9962 |
Gianreto Manatschal | 56 | 200 | 10063 |
Nikolai M. Shapiro | 56 | 154 | 15508 |
Guillaume Morin | 55 | 156 | 7218 |