Omprioritering av gatuutrymmet : En kunskapsöversikt

Rapporten ger en översyn kring forskning gällande olika sätt att förstå och omprioritera existerande gatuutrymme

A Sr-Rich Star on the Main Sequence of Omega Centauri

Abundance ratios relative to iron for carbon, nitrogen, strontium and barium are presented for a metal-rich main sequence star ([Fe/H]=--0.74) in the globular cluster omega Centauri. This star, designated 2015448, shows depleted carbon and solar nitrogen, but more interestingly, shows an enhanced abundance ratio of strontium [Sr/Fe] ~ 1.6 dex, while the barium abundance ratio is [Ba/Fe]<0.6 dex. At this metallicity one usually sees strontium and barium abundance ratios that are roughly equal. Possible formation scenarios of this peculiar object are considered.Comment: 13 pages, 3 figures. Accepted to ApJ

Isophotal Shapes of Early-type Galaxies to Very Faint Levels

We report on a study of the isophotal shapes of early-type galaxies to very faint levels, reaching ~0.1% of the sky brightness. The galaxies are from the Large Format Camera (LFC) fields obtained using the Palomar 5 m Hale Telescope, with integrated exposures ranging from 1 to 4 hr in the Sloan Digital Sky Survey r, i, and z bands. The shapes of isophotes of early-type galaxies are important, as they are correlated with the physical properties of the galaxies and are influenced by galaxy formation processes. In this paper, we report on a sample of 132 E and SO galaxies in one LFC field. We have redshifts for 53 of these, obtained using AAOmega on the Anglo-Australian Telescope. The shapes of early-type galaxies often vary with radius. We derive average values of isophotal shape parameters in four different radial bins along the semi-major axis in each galaxy. We obtain empirical fitting formulae for the probability distribution of the isophotal parameters in each bin and investigate for possible correlations with other global properties of the galaxies. Our main finding is that the isophotal shapes of the inner regions are statistically different from those in the outer regions. This suggests that the outer and inner parts of early-type galaxies have evolved somewhat independently

Sodium naphthalene-2,6-dicarboxylate : an anode for sodium batteries

We thank the EPSRC (EP/K025112/1) and the Leverhulme Trust (RPG-2016-323) for funding and Diamond Light Source for rapid access to synchrotron radiation facilities.The conjugated dicarboxylate, sodium naphthalene-2,6-dicarboxylate (Na2NDC), has been prepared by a low energy consumption reflux method and its performance as a negative electrode for sodium-ion batteries evaluated in electrochemical cells. The structure of Na2NDC was solved for the first time (monoclinic P21/c) from powder X-ray diffraction data and consists of π-stacked naphthalene units separated by sodium-oxygen layers. Through an appropriate choice of binder and conducting carbon additive Na2NDC exhibits a reversible two electron sodium insertion at around 0.4 V vs. Na+/Na with remarkably stable capacities of ca. 200 mA h g-1 at a rate of C/2 and good rate capability (~133 mA h g-1 at 5C). In parallel the high thermal stability of the material is demonstrated by HT-X-ray diffraction, the framework remaining intact to above 500 °C.PostprintPeer reviewe

Abundances on the Main Sequence of Omega Centauri

Abundance ratios of carbon, nitrogen and strontium relative to iron, calculated using spectrum synthesis techniques, are given for a sample of main sequence and turnoff stars that belong to the globular cluster omega Centauri. The variations of carbon, nitrogen and/or strontium show several different abundance patterns as a function of [Fe/H]. The source of the enhancements/depletions in carbon, nitrogen and/or strontium may be enrichment from asymptotic giant branch stars of low (1--3 solar masses) and intermediate (3--8 solar masses) mass. Massive rotating stars which produce excess nitrogen without carbon and oxygen overabundances may also play a role. These abundances enable different contributors to be considered and incorporated into the evolutionary picture of omega Cen.Comment: 43 Pages, 13 Figures. Accepted for publication in Ap

Book Reviews

Review of the following books: Nearby History: Exploring the Past Around You by David E. Kyvig and Myron A. Marty; The Forerunners: The Tragic Story of 156 Down-East Americans Led to Jaffa in 1866 by Charismatic G.J. Adams to Plant the Seeds of Modern Israel by Reed M. Holmes; Islands of Maine: Where America Really Began by Bill Caldwell; Foundations of Northeast Archaeology edited by Dean R. Snow; A Short History of the American Locomotive Builders in the Steam Era by John H. Whit

Working Together: Building K-12/College Mentor Partnerships to Support Students with Learning Differences

In an interactive discussion with audience members, presenters will share ideas for developing positive mentor-mentee partnerships between K-12 schools and colleges; discuss the impact of two recently established mentor partnerships, as well as perspectives from college student mentors and K-12 teachers of student mentees with learning differences; collaboratively examine data to discuss potential program adaptations; and provide mentoring activities that audience members can utilize