Sodium recycling at Europa: what do we learn from the sodium cloud variability ?

International audienceWe study the ejection of sodium atoms from Europa's surface by both magnetospheric ion and electron sputtering and desorption stimulated by UV solar photons. The depletion of the surface by ejection and its enrichment by redeposition of sodium atoms are described. The redistribution of sodium atoms at the surface induced by photo-stimulated desorption from the dayside and by sputtering ejection from the trailing hemisphere cannot explain the observed variation of the Na emission brightness. However, a transient increase of the sputtering rate due to a plasma injection may explain such an increase. The relationship between the sodium surface content and the sodium exosphere are also discussed

Three\u27s Company: Collaborative Instructional Design on a Librarian-Instructor Team

This session will describe a unique collaboration that resulted in development of a strategic research assignment design supported by relevant information literacy sessions. This effort stems from an existing relationship between research librarians and an instructor who was previously a graduate assistant in Research & Instruction Services and became an instructor of a general education course in Communication Sciences and Disorders. Through this collective, a synergistic arrangement developed where librarians contribute to research assignment design and the instructor contributes to developing the information literacy sessions to prepare students for finding, evaluating, and understanding relevant scholarly articles early in their college career. We will provide suggestions for developing librarian-instructor relationships that help identify student pain points as well as guide the development of customized classroom assignments relevant to beginning a student’s research path. We will also introduce strategies we have found successful in helping students locate and synthesize relevant scholarly articles, in the classroom and online, for more effective information literacy session activities

The motley family of polar compounds (MV) M(X5-xX (x)) based on anionic chains of trans-connected M-(III)(X,X)(6) octahedra (M=Bi, Sb; X, X=Cl, Br, I) and methylviologen (MV) dications

The search for hybrid organic-inorganic materials remains a great challenge in the field of ferroelectrics. Following the discovery of the room temperature ferroelectric material (MV)[BiI3Cl2] (MV2+: methyl-viologen) exhibiting the highest polarization value in the field of hybrid ferroelectrics, we report here nine new hybrids with the general formulation (MV)[(MX5-xX)-X-(III)(x)] (M=Bi, Sb; X, X=CI, Br, I): (MV)[BiCl3.3Br1.7] (1), (MV)[BiCl1.3Br3.7] (2), (MV)[BiBr3.2I1.8] (3), (MV)[SbCl5] (4), (MV)[SbBr5] (5), (MV)[SbCl3.8Br1.2] (6). (MV)[SbCl2.4Br2.6] (7), (MV)[SbI3Cl2] (8) and (MV)[SbBr3.8I1.2] (9). Depending on the presence of polar chains or not, and on the coupling of polar chains, two types of centrosymmetrical structures [C1] and [C2] and two types of polar structures [P1] and [P2] are defined. (2) undergoes a paraelectric-to-relaxor ferroelectric transition around 100-150 K depending of the frequency showing that the Curie temperature, T-C, of (MV)[BiBr5] (243 K) can be modulated by the substitution of Br by Cl. The most interesting family is the [P2] type because the syn coupling of polar chains is in favor of high polarization values, as in (MV)[BiI3Cl2]. Five of the nine new hybrids, (4), (6-9), which have the [P2] type structure are potential ferroelectrics. (C) 2012 Elsevier Inc. All rights reserved