Split Comet C/2001 A2 (LINEAR)     

Jehin  Emmanuel  Boehnhardt  Hermann  Sekanina  Zdenek  Bonfils  Xavier  Schütz  Oliver  Beuzit  Jean-Luc  Billeres  Malvina  Garradd  Gordon J.  Leisy  Pierre  Marchis  Franck  Más  Antonio  Origlia  Livia  Scarpa  Daniel  Thomas  Daniel  Tozzi  Gian Paolo 《Earth, Moon, and Planets》2002,90(1-4):147-151

Comet C/2001 A2 experienced several splitting events duringits 2001 perihelion passage. The first break-upevent was observed in March 2001 (IAUC 7616).In this paper we report the first results of ourextensive imaging and spectroscopic monitoring campaignwith ESO telescopes over several weeks before andafter the perihelion passage on May 25 2001.  相似文献   

Progress on the Front of Pulsating Subdwarf B Stars     

Gilles Fontaine  Elizabeth M. Green  Pierre Brassard  Stéphane Charpinet  Pierre Chayer  Malvina Billères  Suzanna K. Randall  Ben Dorman 《Astrophysics and Space Science》2004,291(3-4):379-386

We briefly review the recent advances that have been made on the front of pulsating subdwarf B (sdB) stars. The first family of sdB pulsators, the EC 14026 stars, was discovered a few years ago and consists of short-period (～100?200 s) p-mode variables. The second type of pulsating sdB’s consists of the PG 1716+426 stars, a group of variables showing long-period (～1 h) g-mode pulsations. The existence of the latter was first reported less than a year ago. While the two types of sdB pulsators differ markedly in their observational characteristics, we recently found a unifying property in the sense that the observed modes in these objects are excited through the same driving process, a classic kappa mechanism associated with the radiative levitation of iron in the stellar envelope.  相似文献   

Improving Properties of Sand Using Epoxy Resin and Electrokinetics     

Costas A. Anagnostopoulos  Panagiotis Kandiliotis  Malvina Lola  Sarafianos Karavatos 《Geotechnical and Geological Engineering》2014,32(4):859-872

The use of new materials for soil strengthening is crucial for geotechnical engineering, especially in foundation construction. The main objective of this study was to investigate the potential use of two-component water-soluble epoxy resin to improve the physical and mechanical properties of medium sand, because the efficacy of these resins on soil strengthening has not yet been properly investigated. The experiments were conducted using resins with different epoxy resin-to-water ratios. The results of this study indicate that the epoxy resins improve the physical and mechanical properties of the sand significantly, and if successfully grouted into a formation, the resins could provide a suitable solution for the stabilization of the foundation material. In separate experiments, electroosmotic treatment of sand/resin mixtures was conducted with the aim of identifying the effectiveness of electro kinetic method on the early strength development of sand/resin mixtures. From the results it was observed that the electroosmotically treated specimens appeared to have much greater strength enhancement than the one of the untreated specimens.  相似文献