Proceedings of the 7th Semiannual Meeting of the Nozzle Initiative Industry Advisory Committee on Standardization of Carbon-Phenolic Test Methods and Specifications

The application of carbon fibers and fabrics (CF) for producing rocket nozzles is discussed. These materials which are essential for fabricating the carbon composites used in aerospace systems gasify when exposed to high temperatures and the mechanical properties of the composites degrade. The oxidation kinetics under isothermal (IC) and non-isothermal (NIC) conditions are examined and a comparison is made between the characteristics of IC and NIC oxidation. Several CF, chars, and carbon blacks were examined, including a microporous char, a graphitized rayon fabric, and several carbonized rayon fabrics. A summary is given of the advantages and drawbacks of isothermal and non-isothermal oxidation of carbons. The proceedings are assembled in the form of a roundtable discussion

Aquilegia, Vol. 25 No. 1-2, January-February 2001: Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1183/thumbnail.jp

Magnetic White Dwarfs from the SDSS II. The Second and Third Data Releases

Fifty-two magnetic white dwarfs have been identified in spectroscopic observations from the Sloan Digital Sky Survey (SDSS) obtained between mid-2002 and the end of 2004, including Data Releases 2 and 3. Though not as numerous nor as diverse as the discoveries from the first Data Release, the collection exhibits polar field strengths ranging from 1.5MG to ~1000MG, and includes two new unusual atomic DQA examples, a molecular DQ, and five stars that show hydrogen in fields above 500MG. The highest-field example, SDSSJ2346+3853, may be the most strongly magnetic white dwarf yet discovered. Analysis of the photometric data indicates that the magnetic sample spans the same temperature range as for nonmagnetic white dwarfs from the SDSS, and support is found for previous claims that magnetic white dwarfs tend to have larger masses than their nonmagnetic counterparts. A glaring exception to this trend is the apparently low-gravity object SDSSJ0933+1022, which may have a history involving a close binary companion.Comment: 20 pages, 4 figures Accepted for publication in the Astronomical Journa

Double-Peaked Low-Ionization Emission Lines in Active Galactic Nuclei

We present a new sample of 116 double-peaked Balmer line Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey. Double-peaked emission lines are believed to originate in the accretion disks of AGN, a few hundred gravitational radii (Rg) from the supermassive black hole. We investigate the properties of the candidate disk emitters with respect to the full sample of AGN over the same redshifts, focusing on optical, radio and X-ray flux, broad line shapes and narrow line equivalent widths and line flux-ratios. We find that the disk-emitters have medium luminosities (~10^44erg/s) and FWHM on average six times broader than the AGN in the parent sample. The double-peaked AGN are 1.6 times more likely to be radio-sources and are predominantly (76%) radio quiet, with about 12% of the objects classified as LINERs. Statistical comparison of the observed double-peaked line profiles with those produced by axisymmetric and non-axisymmetric accretion disk models allows us to impose constraints on accretion disk parameters. The observed Halpha line profiles are consistent with accretion disks with inclinations smaller than 50 deg, surface emissivity slopes of 1.0-2.5, outer radii larger than ~2000 Rg, inner radii between 200-800Rg, and local turbulent broadening of 780-1800 km/s. The comparison suggests that 60% of accretion disks require some form of asymmetry (e.g., elliptical disks, warps, spiral shocks or hot spots).Comment: 60 pages, 19 figures, accepted for publication in AJ. For high quality figures and full tables, please see http://astro.princeton.edu/~iskra/disks.htm

‘Everyone can imagine their own Gellert’: the democratic artist and ‘inclusion’ in primary and nursery classrooms

What do artists do when they work in schools? Can teachers do the same? These were the questions at the heart of our recent research, investigating the work of 12 artists working in primary and secondary schools in England. Funded by Creativity, Culture and Education as a ‘legacy’ project of Creative Partnerships (2003–2011) our intention was to develop a theorisation of artists’ practice that could inform the work that teachers do. In this paper, we report on a key aspect of the Signature Pedagogies project (www.signaturepedagogies.org.uk) the way in which artists approached the issue of inclusion. Through an examination of the work of three story-makers in primary and nursery schools, documented through observation, film and interview, we show that the democratic participatory practices they adopted were based on a fundamental belief that: every child was capable of having ideas; every child could contribute meaningfully to discussions; and every child was integral to a collective ‘performance’. We conclude that these artists’ democratic orientations may well be difficult for teachers to adopt in the current moment, but that this artistic work in schools may still provide a welcome relief for all involved, as well as maintaining an exemplar of alternative pedagogical practice that might be expanded in a changed policy environment

"From ‘What the hell is going on?’ to the ‘Mushy middle ground’ to ‘getting used to a new normal’: Young people’s biographical narratives around navigating parental dementia"

The number of young people who have a parent with dementia is rising as a result of improvements in diagnosis of young onset variants and demographic shifts. There has, however, been very little research focusing on this group. Accounts elicited as part of the Perceptions and Experiences of Young People With a Parent With Dementia described the period, usually some years, leading up to a diagnosis of a dementia and then the progress of the condition post diagnosis. These narratives were characterised by confusion, uncertainty, trauma and distress as the young people struggled to make sense of the significant and often extreme, behavioural and attitudinal changes that were symptoms of the illness. This paper describes and discusses how the young people experienced and navigated the temporal messiness and consequent biographical disruption arising from parental dementia

Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys

We discuss the optical and radio properties of 30,000 FIRST sources positionally associated with an SDSS source in 1230 deg$^2$ of sky. The majority (83%) of the FIRST sources identified with an SDSS source brighter than r=21 are optically resolved. We estimate an upper limit of 5% for the fraction of quasars with broad-band optical colors indistinguishable from those of stars. The distribution of quasars in the radio flux -- optical flux plane supports the existence of the "quasar radio-dichotomy"; 8% of all quasars with i<18.5 are radio-loud and this fraction seems independent of redshift and optical luminosity. The radio-loud quasars have a redder median color by 0.08 mag, and a 3 times larger fraction of objects with red colors. FIRST galaxies represent 5% of all SDSS galaxies with r<17.5, and 1% for r<20, and are dominated by red galaxies. Magnitude and redshift limited samples show that radio galaxies have a different optical luminosity distribution than non-radio galaxies selected by the same criteria; when galaxies are further separated by their colors, this result remains valid for both blue and red galaxies. The distributions of radio-to-optical flux ratio are similar for blue and red galaxies in redshift-limited samples; this similarity implies that the difference in their luminosity functions, and resulting selection effects, are the dominant cause for the preponderance of red radio galaxies in flux-limited samples. We confirm that the AGN-to-starburst galaxy number ratio increases with radio flux, and find that radio emission from AGNs is more concentrated than radio emission from starburst galaxies (abridged).Comment: submitted to AJ, color gif figures, PS figures available from [email protected]

'It would be easier if she’d died’: young people with parents with dementia articulating inadmissible stories

In the U.K. context where the emphasis is (quite rightly) on living well with dementia, on positivity and enabling approaches, it can be difficult for researchers to investigate and report negative experiences. Failing to re-present perceptions and experiences as they are lived, however, does a serious disservice to the research endeavor and can prevent policy and service development and positive change. In this article, we present some stories told by participants in an Alzheimer’s Society (United Kingdom) Funded project uniquely investigating the perceptions and experiences of children and young people who have a parent with dementia. Sometimes the stories were not easy to hear, especially when they challenged dominant master narratives around dementia. We discuss our view that when the young people we spoke with told us how things were for them, we were ethically bound to respect and disseminate their accounts

‘Scaling up’ educational change: some musings on misrecognition and doxic challenges

Educational policy-makers around the world are strongly committed to the notion of ‘scaling up’. This can mean anything from encouraging more teachers to take up a pedagogical innovation, all the way through to system-wide efforts to implement ‘what works’ across all schools. In this paper, I use Bourdieu’s notions of misrecognition to consider the current orthodoxies of scaling up. I argue that the focus on ‘process’ and ‘implementation problems’: (1) both obscures and legitimates the ways in which the field logics of practice actually work and, (2) produces/reproduces the inequitable distribution of educational benefits (capitals and life opportunities). I suggest that the notion of misrecognition might provide a useful lens through which to examine reform initiatives and explanations of their success/failure

Trans youth, science and art: creating (trans) gendered space

This article is based on empirical research which was undertaken as part of the Sci:dentity project funded by the Wellcome Trust. Sci:dentity was a year-long participatory arts project which ran between March 2006 and March 2007. The project offered 18 young transgendered and transsexual people, aged between 14 and 22, an opportunity to come together to explore the science of sex and gender through art. This article focuses on four creative workshops which ran over two months, being the ‘creative engagement’ phase of the project. It offers an analysis of the transgendered space created which was constituted through the logics of recognition, creativity and pedagogy. Following this, the article explores the ways in which these transgendered and transsexual young people navigate gendered practices, and the gendered spaces these practices constitute, in their everyday lives shaped by gendered and sexual normativities. It goes on to consider the significance of trans virtual and physical cultural spaces for the development of trans young peoples' ontological security and their navigations and negotiations of a gendered social world