2,973 research outputs found
Allendeite and Hexamolybdenum: Two New Ultra-Refractory Minerals in Allende and Two Missing Links
During our nano-mineralogy investigation
of the Allende meteorite, we discovered two
new minerals that occur as micro- to nano-crystals in
refractory inclusions: Allendeite, Sc_4Zr_3O_(12), a new Scand
Zr-rich oxide; and hexamolybdenum, (Mo,Ru,Fe),
a Mo-dominant alloy. Allendeite, which may be an
important ultra-refractory carrier linking Zr-, Sc- oxides
and the more common Sc-, Zr-enriched clinopyroxenes
(Cpx) in CAIs, hosts perovskite (Pv), spinel
(Sp), Os-Ir-W-Mo alloys, and hexamolybdenum. The
observation of two structurally and chemically distinct
highly refractory, low-Pt alloy minerals not associated
with Fe-Ni alloys provides the first direct physical
evidence for at least two separate carriers of the highly
refractory metals in CAIs. Hexamolybdenum links Osrich
and Pt-rich meteoritic alloys and may be a precursor
of the latter. Both new minerals have been approved
by the Commission on New Minerals, Nomenclature
and Classification of the International Mineralogical
Association (IMA 2007-027, 029)
Humility, Self-Awareness, and Religious Ambivalence: Another Look at Beckett's âHumanistic Quietismâ
This is the accepted manuscript. The final version is available from Edinburgh University Press at http://www.euppublishing.com/doi/abs/10.3366/jobs.2014.0104. This article provides a commentary on the opaque and often contradictory arguments of âHumanistic Quietismâ, Samuel Beckett's 1934 review of Thomas MacGreevy's Poems. Using Beckett's complicated relationship to both his own Protestant upbringing and the Catholicism of MacGreevy as a starting point, the article proposes new ways of understanding Beckett's ambivalent comments about MacGreevy's interiority, prayer-like poetry, humility, and quietism. It draws on Beckett's comments on Rilke, AndrĂ© Gide, and Arnold Geulincx, as well as his familiarity with Dante, to unpack the review's dense allusions and make sense of Beckett's aesthetic allegiances. </jats:p
Media coverage and public understanding of sentencing policy in relation to crimes against children
This research examines how the media report on sentences given to those who commit serious crimes against children and how this impacts on public knowledge and attitudes. Three months of press and television coverage were analysed in order to establish the editorial lines that are taken in different sections of the media and how they are promoted by selective reporting of sentencing. Results indicate that a small number of very high profile crimes account for a significant proportion of reporting in this area and often, particularly in the tabloid press, important information regarding sentencing rationale is sidelined in favour of moral condemnation and criticism of the judiciary. Polling data indicate that public attitudes are highly critical of sentencing but also confused about the meaning of tariffs. The article concludes by discussing what can be done to promote a more informed public debate over penal policy in this area
An Experimental Study of Metallic Diffusion and Phase Equilibria in Fremdlinge
Fremdlinge are opaque assemblages within CAis that are mainly composed of NiFe metal, V-magnetite and ”m-sized RuOs nuggets. The prevailing scenario for their origin includes condensation, aggregation and equilibration at low T (⟠600°C); they are then thought to be introduced into CAis at high T, followed by rapid cooling, thereby preserving the textures and assemblages from the pre-CAl, low T histories (Armstrong et al., 1985; Armstrong et al., 1987). A constraint on cooling rates of Fremdlinge comes from sharp contacts observed between RuOs nuggets and NiFe
metals that enclose them. To determine the length of time that these contacts could have been held at high T, thin-film diffusion experiments were conducted with an
electroplated Ru film on Ni. Samples were annealed at 1400, 1200, 1000 and 800°C for 0.3-137 hours. Measured Ru profiles in Ni were consistent with the following Arrhenius expression: D(cm^2/sec) = 0.0050exp(-2.3 x 10^(12)/RT) (T in K, R in Cgs units). Based on these data, we calculate that cooling rates of Ⳡ10^5C/hr are necessary to preserve sharp contacts between RuOs and NiFe metals if they experienced the T of CAl melting (~ 1400°C) (Stolper and Paque, 1986). We consider this rate unreasonable in light of cooling rates inferred from experimental studies of the silicate portions of CAis (10^(-1) to 10^2°C/hr) (Stolper and Paque, 1986)
Human mummification practices among the Ibaloy of Kabayan, North Luzon, the Philippines
The province of Benguet, situated in North Luzon, the Philippines, holds a large number of ancient mummified remains, mostly located within the municipality of Kabayan. Such bodies are mainly associated to the Ibaloy â one of the indigenous groups collectively known as Igorot â and are stored in natural rockshelters or caves carved into the stone, inside wooden coffins often obtained from hollowed pine tree segments. Recent inspections of some of these corpses, carried out in 2002 and 2012, indicated the nature of their mummification process as well as some details regarding their bioanthropological features. Although very little information was initially available on these bodies, the authors have gathered significant oral information on funerary rituals and attitudes towards the ancestors via interviews with the local elders, as well as data on the vegetal materials employed and the practice of tattooing. This paper is the first critical evaluation of these mummies and demonstrates the uniqueness and preciousness of this biocultural heritage now in danger
The Las Campanas IR Survey: Early Type Galaxy Progenitors Beyond Redshift One
(Abridged) We have identified a population of faint red galaxies from a 0.62
square degree region of the Las Campanas Infrared Survey whose properties are
consistent with their being the progenitors of early-type galaxies. The optical
and IR colors, number-magnitude relation and angular clustering together
indicate modest evolution and increased star formation rates among the
early-type field population at redshifts between one and two. The counts of red
galaxies with magnitudes between 17 and 20 rise with a slope that is much
steeper than that of the total H sample. The surface density of red galaxies
drops from roughly 3000 per square degree at H = 20.5, I-H > 3 to ~ 20 per
square degree at H = 20, I-H > 5. The V-I colors are approximately 1.5
magnitudes bluer on average than a pure old population and span a range of more
than three magnitudes. The colors, and photometric redshifts derived from them,
indicate that the red galaxies have redshift distributions adequately described
by Gaussians with sigma_z ~ 0.2V-I3$ are primarily in the 1.5 < z < 2
range. We find co-moving correlation lengths of 9-10 Mpc at z ~ 1, comparable
to, or larger than, those found for early-type galaxies at lower redshifts. A
simple photometric evolution model reproduces the counts of the red galaxies,
with only a ~ 30% decline in the underlying space density of early-type
galaxies at z ~ 1.2. We suggest on the basis of the colors, counts, and
clustering that these red galaxies are the bulk of the progenitors of present
day early-type galaxies.Comment: 5 pages, 3 figures, accepted for publication in the ApJ Letter
The Las Campanas Infrared Survey. III. The H-band Imaging Survey and the Near-Infrared and Optical Photometric Catalogs
(Abridged) The Las Campanas Infrared Survey, based on broad-band optical and
near-infrared photometry, is designed to robustly identify a statistically
significant and representative sample of evolved galaxies at redshifts z>1. We
have completed an H-band imaging survey over 1.1 square degrees of sky in six
separate fields. The average 5 sigma detection limit in a four arcsecond
diameter aperture is H ~ 20. Here we describe the design of the survey, the
observation strategies, data reduction techniques, and object identification
procedures. We present sample near-infrared and optical photometric catalogs
for objects identified in two survey fields. We perform object detection in all
bandpasses and identify ~ 54,000 galaxies over 1,408 square arcminutes of sky
in the two fields. Of these galaxies, ~ 14,000 are detected in the H-band and ~
2,000 have the colors of evolved galaxies, I - H >3, at z > 1. We find that (1)
the differential number counts N(m) for the H-band detected objects has a slope
of 0.44 at H 19. In addition, we find that (2) the
differential number counts for the H detected red objects has a slope of 0.85
at H 20, with a mean surface density ~ 3,000 degree^{-2}
mag^{-1} at H=20. Finally, we find that (3) galaxies with red optical to
near-IR colors (I-H > 3) constitute ~ 20% of the H detected galaxies at H ~ 21,
but only 2% at H = 19. We show that red galaxies are strongly clustered, which
results in a strong field to field variation in their surface density.
Comparisons of observations and predictions based on various formation
scenarios indicate that these red galaxies are consistent with mildly evolving
early-type galaxies at z ~ 1, although with a significant amount of on-going
star formation as indicated by the large scatter in their V-I colors.Comment: 48 pages, 13 figures, accepted for publication in the Astrophysical
Journa
Urban informality and confinement: toward a relational framework
In the 21st century, a growing number of people live âinformalâ lives within fissures between legality and informality. Concomitantly, power relations are increasingly expressed through devices of confinement. While urban informality and confinement are on the rise often occurring simultaneously, scholars have so far studied them separately. By contrast, this article proposes a new framework for analysing urban informality and confinement relationally. It generates new insights into the role of informality in the (re)production of confinement and, vice versa, the role of confinement in shaping informal practices. While these insights are valuable for urban studies in general, the article charts new lines of research on urban marginality. It also discusses how the six articles included in this special issue signal the heuristic potential of this relational framework by empirically examining distinct urban configurations of âconfined informalitiesâ and âinformal confinementsâ across the Global North and the Global South
In-situ Discovery of a Cluster of Refractory Grains in an Allende Ferromagnesian Chondrule
During our nano-mineralogy investigation of the Allende meteorite, we discovered a unique corundum-rich cluster of irregular micrometer-sized refractory grains in a type IA chondrule. The presence of relatively oxidized (rutile) and highly reduced (a new mineral Ti_2O_3, khamrabaevite) phases in the same cluster reflects distinctly different environments prior to incorporation of the cluster into the chondrule. To our knowledge, this is the first occurrence of such a cluster. Investigation of phases that are clearly exotic to the host chondrule and may predate its formation can provide not only important constraints on the materials present when chondrules formed and the enviroments within or outside the Protoplanetary disk, but also on the chondrule formation event. Herein we report our prelimary results on the mineralogy of these grains and the overall petrology of their host chondrule
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