Fixation of virgin lunar surface soil

Two systems are shown to be suitable for fixing loose particulate soils with a polymer film, without visually detectable disturbance of the soil particle spatial relationships. A two-component system is described, which uses a gas monomer condensible at the soil temperature and a gas phase catalyst acting to polymerize the monomer. A one-component system using a monomer which polymerizes spontaneously on and within the top few millimeters of the soil is also considered. The two-component system employs a simpler apparatus, but it operates over a narrower temperature range (approximately -40 to -10 C). Other two-component systems were identified which may operate at soil temperatures as high as +100 C, at relatively narrow temperature ranges of approximately 30 C. The one-component system was demonstrated to operate successfully with initial soil temperatures from -70 C or lower to +150 C

Forest diagrams for elements of Thompson's group F

We introduce forest diagrams to represent elements of Thompson's group F. These diagrams relate to a certain action of F on the real line in the same way that tree diagrams relate to the standard action of F on the unit interval. Using forest diagrams, we give a conceptually simple length formula for elements of F with respect to the {x_0,x_1} generating set, and we discuss the construction of minimum-length words for positive elements. Finally, we use forest diagrams and the length formula to examine the structure of the Cayley graph of F.Comment: 44 pages, 70 figure

MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E

We report on the discovery of ionised gas filaments in the circum-galactic halo of the extremely metal-poor compact starburst SBS 0335-052E in a 1.5h integration with the MUSE integral-field spectrograph. We detect these features in H${\alpha}$ and [OIII] emission down to surface-brightness levels of $5 \times 10^{-19}$erg s$^{-1}$cm$^{-2}$arcsec$^{-2}$. The filaments have projected diameters of 2.1 kpc and extend more than 9 kpc to the north and north-west from the main stellar body. We also detect extended nebular HeII $\lambda$4686 emission that brightens towards the north-west at the rim of a star-burst driven super-shell, suggestive of a locally enhanced UV radiation field due to shocks. We also present a velocity field of the ionised gas. The filaments appear to connect seamlessly in velocity space to the kinematical disturbances caused by the shell. Similar to high-$z$ star-forming galaxies, the ionised gas in this galaxy is dispersion dominated. We argue that the filaments were created via feedback from the starburst and that these ionised structures in the halo may act as escape channels for Lyman continuum radiation in this gas-rich system.Comment: Revised version after peer review. Accepted for publication in A&A letter

Pedagogies of production: Re-imagining literacies for the digital age

This chapter reflects on the relationships between film, digital media, and new literacy and learning practices and explores the ways in which the study and production of audiovisual texts can be integrated into school settings. The chapter also considers the attendant new pedagogies to which film and media-making give rise, including the development of fluid and less hierarchical teaching practices that speak better to the everyday digital lives of children and young people in relation to the sociopolitical barriers to progressive education. Arguing in favor of more collaborative, social, and dynamic literacies inclusive of the moving image, the authors support the view that film is one of the foremost art forms of the last and the current century

Phase Diagram of One-Dimensional Extended Hubbard Model at Half Filling

We reexamine the ground-state phase diagram of the one-dimensional half-filled Hubbard model with on-site and nearest-neighbor repulsive interactions. We calculate second-order corrections to coupling constants in the g-ology to show that the bond-charge-density-wave (BCDW) phase exists for weak couplings in between the charge density wave (CDW) and spin density wave (SDW) phases. We find that the umklapp scattering of parallel-spin electrons destabilizes the BCDW state and gives rise to a bicritical point where the CDW-BCDW and SDW-BCDW continuous-transition lines merge into the CDW-SDW first-order transition line.Comment: 4 pages, 3 figure

Dynamic, Playful and Productive Literacies

This paper reflects on recent projects in a variety of media forms, in both formal and informal educational settings, discussing ways of expanding our notions of literacy practices which reflect their place in the wider lived experience of digital culture. We have collected these reflections under three headings. The first of these, Dynamic Literacies, presents an overarching view of literacy as both ideological, following the ‘new literacy studies’, and dynamic, incorporating both semiotic and sociocultural versions of literacy in ways which reflect the changing nature of lived experience in the digital age. The second strand, Productive Literacies, constructs an argument around digital making practices with younger learners which views these as media crafting, critique and artistry. The third strand, Playful Literacies, explores recent projects which are located in games and game-authoring practices as a specific example of connecting pedagogy to contemporary media forms and learner agency in formal and informal settings. Taken together, the three perspectives allow for common ground to be established between multimodal production practices, whilst providing suggestions for framing literacy pedagogy in response to the pervasive use of media and technology in contemporary digital culture