Chemical compositions and plasma parameters of planetary nebulae with Wolf-Rayet and wels type central stars

Aims: Chemical compositions and other properties of planetary nebulae around central stars of spectral types [WC], [WO], and wels are compared with those of `normal' central stars, in order to clarify the evolutionary status of each type and their interrelation. Methods: We use plasma diagnostics to derive from optical spectra the plasma parameters and chemical compositions of 48 planetary nebulae. We also reanalyze the published spectra of a sample of 167 non-WR PN. The results as well as the observational data are compared in detail with those from other studies of the objects in common. Results: The central star's spectral type is clearly correlated with electron density, temperature and excitation class of the nebula, [WC] nebulae tend to be smaller than the other types. All this corroborates the view of an evolutionary sequence from cool [WC 11] central stars inside dense, low excitation nebulae towards hot [WO 1] stars with low density, high excitation nebulae. The wels PN, however, appear to be a separate class of objects, not linked to WRPN by evolution, --abridged--Comment: 17 pages, 28 figures, Accepted in A&A. Accepted in A&

For Joan:Some letters with reverence, an honorary degree, and a dialogical tribute

In 2012, I co‐taught, with Anne‐Charlott Callerstig, a master's course module at Linköping University in Swedenentitled ‘Intersectional Gender, and Institutional and Organizational Work’. Towards the end of the course I was emailed by Donald Van Houten asking for contributions to a text to be presented at a reception on International Women's Day, 8 March 2012, at the University of Oregon, honouring Joan Acker and her remarkable career. The reception was part of the Lorwin Lecture Series on ‘Civil Rights and Civil Liberties’ and the Wayne Morse Center symposium on ‘Gender Equity and Capitalism’. To honour Joan and her legacy, I was asked to send a personal statement testifying to Joan's impact on her life and work, to be collected together in a small book. We were using some of Joan's writing as key texts on the module, so it seemed appropriate to do something collectively, and accordingly I asked the students to write short ‘letters’ to Joan. I sent off our letters, which we called ‘Some Letters Written with Reverence’; I trust Joan received them and liked them. Therefore, here in this writing for Joan there are three parts. In the first, the ‘letters’ are reproduced; the next is the edited proposal I wrote for Joan to be awarded an honorary doctorate at Hanken School of Economics, the Swedish‐language business school in Helsinki, Finland; she received the honour in 2011; and for the last part, I add an additional personal tribute and reflection from the vantage point of now, today

Newly discovered halos and outer features around southern planetary nebulae

We have used the SuperCOSMOS H-alpha Survey to look for faint outer structures such as halos, ansae and jets around known planetary nebulae across 4000 square degrees of the southern Milky Way. Our search will contribute to a more accurate census of these features in the Galactic PN population. Candidate common-envelope PNe have also been identified on the basis of their microstructures. We also intend to determine more reliable distances for these PNe, which should allow a much better statistical basis for the post-AGB total mass budget. Our survey offers fresh scope to address this important issue.Comment: 2 pages, 1 figure. To be published in Planetary Nebulae: an Eye to the Future, Proceedings of IAU Symposium 283, held in Puerto de la Cruz, Tenerife, Spain, July 25-29 201

Revisiting Joan Acker's work with the support of Joan Acker

This article is a personal tribute to working with Joan Acker. I worked with Joan in 2012, helping to edit her own thoughts and reflection on how other academics evaluate and used her own theorizing, specifically her seminal work on the gender substructure and inequality regimes. However, while this article is a tribute to Joan, her work and her thinking; it is also a personal thank you to someone I will miss for her generosity and also her activism in challenging inequalities in organizations and beyond. She continues to inspire me and hopefully others to challenge for social justice. In her 80s, Joan remained committed to addressing inequalities in social relations and how these were experienced within a dynamic social and work environment. During our collaboration, she called upon academics to put theory into practice to help address visible and invisible inequalities in organizational processes. This article is inspired by that experience and it will reveal Joan's views about her own, and other academics, theorizing of her two key concepts: the gender substructure of organizations and inequality regimes in organizations and the overlap with intersectionality. This article will offer a unique opportunity to gain insight into Joan's thinking as an academic sociologist as well as a feminist activist thereby uniting Joan as a person with her concepts

Follow-up Study of Seventh Grade Students Attending McLoughlin Junior High who, in the Previous Year, were Sixth Graders at King, Harney, Lieser, or Marshall Elementary Schools

The purpose of this field study is actually two-fold. First, one must understand Martin Luther King Elementary School. King is an open concept school. The program is based upon different teaching techniques and philosophies than a more traditional type elementary school. After his years at King, a student then goes on to McLaughlin Junior High. McLaughlin is a typical junior high that is somewhat more regimented than the open environment at King. Parents have asked numerous times, How do these students perform after they leave King and go to a more structured junior high? Until now I have had no data that could be relayed to parents that would answer this question. This study should provide a better understanding of my students and their adjustment to their new environment. Second, during my teaching career I have often wondered how my previous students have adjusted socially and academically to their new surroundings. This study should give insights into the successes or failures of techniques and philosophies in education. From these findings modification can be made if necessary

Binary planetary nebulae nuclei towards the Galactic bulge. II. A penchant for bipolarity and low-ionisation structures

Considerable effort has been applied towards understanding the precise shaping mechanisms responsible for the diverse range of morphologies exhibited by planetary nebulae (PNe). A binary companion is increasingly gaining support as a dominant shaping mechanism, however morphological studies of the few PNe that we know for certain were shaped by binary evolution are scarce or biased. Newly discovered binary central stars (CSPN) from the OGLE-III photometric variability survey have significantly increased the sample of post common-envelope (CE) nebulae available for morphological analysis. We present Gemini South narrow-band images for most of the new sample to complement existing data in a qualitative morphological study of 30 post-CE nebulae. Nearly 30% of nebulae have canonical bipolar morphologies, however this rises to 60% once inclination effects are incorporated with the aid of geometric models. This is the strongest observational evidence yet linking CE evolution to bipolar morphologies. A higher than average proportion of the sample shows low-ionisation knots, filaments or jets suggestive of a binary origin. These features are also common around emission-line nuclei which may be explained by speculative binary formation scenarios for H-deficient CSPN.Comment: Accepted for publication in A&

Experimental steady-state performance of a multitube, centrally finned, potassium condensing radiator

Steady state performance of multitube, centrally finned, potassium condensing radiato