454 research outputs found
Lava Butte wildlife crossing monitoring project
No full textThis archived document is maintained by the Oregon State Library as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Title from PDF caption (viewed on April 20, 2016)."Prepared on: June 30th 2015, finalized: October 8th, 2015."Evaluates the effectiveness of crossing structures located near Crawford Road Bridges near Lava Lands Visitor Center and South Lava Butte Bridges.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
Pressurized lunar lava tubes for habitation
No full textLava tubes are subterranean tubes that form as a result of lava flows and extend for long distances beneath the surface of a planet. They are a naturally occurring feature of Earth’s Moon. For decades these cave systems have piqued the interest of researchers, not just for their geological complexity, but also for their potential as a future human habitation site on the Moon. The internal environment of lunar lava tubes promises a benign alternative in comparison to the harsh lunar surface; they provide natural protection from radiation, micrometeoroids, and extreme temperature fluctuations. This thesis furthers the study of lunar lava tubes by presenting the possibility of pressurizing them with breathable air. Using a 2D ANSYS simulation model, a range of lava tube sizes are subjected to varied magnitude of internal pressurization. It is ultimately concluded that it is possible to pressurize a small lava tube while maintaining its structural integrity.M.S.Includes bibliographical reference
Local adaptation does not lead to genome-wide differentiation in lava flow lizards
No full textAdaptation can occur with or without genome-wide differentiation. If adaptive loci are linked to traits involved in reproductive isolation, genome-wide divergence is likely, and speciation is possible. However, adaptation can also lead to phenotypic differentiation without genome-wide divergence if levels of ongoing gene flow are high. Here, we use the replicated occurrence of melanism in lava flow lizards to assess the relationship between local adaptation and genome-wide differentiation. We compare patterns of phenotypic and genomic divergence among lava flow and nonlava populations for three lizard species and three lava flows in the Chihuahuan Desert. We find that local phenotypic adaptation (melanism) is not typically accompanied by genome-wide differentiation. Specifically, lava populations do not generally exhibit greater divergence from nonlava populations than expected by geography alone, regardless of whether the lava formation is 5,000 or 760,000 years old. We also infer that gene flow between lava and nonlava populations is ongoing in all lava populations surveyed. Recent work in the isolation by environment and ecological speciation literature suggests that environmentally driven genome-wide differentiation is common in nature. However, local adaptation may often simply be local adaptation rather than an early stage of ecological speciation.BN/Liedewij Laan La
Mellan hemmet och bergen : Fängslade kurdiska partikvinnors vokala motstånd och sångens politik
No full textAs one of the largest demographics of political prisoners in Turkey and among the most incarcerated women politicians in the world, Kurdish women are able to share precious knowledge about anti-imperialist feminist struggle. Framed by Adriana Cavarero’s (2005) theory of vocal expression, Patricia Hill Collins’ (2000) notion of self-definition, and Saidiya Hartman’s (2019) critical fabulation of the Black chorus, I have conducted a text analysis of imprisoned Kurdish women MPs’ letters to understand how they practice a vocal resistance in contradiction to the binary economy that privileges political speech to Man and relegates Woman to silence or the maternal lullaby. Instead, this thesis argues that Kurdish party women practice a politics of song. Meaning, that the sound of the Kurdish party women’s voices communicate their uniqueness in excess of patriarchal scripts, creating in-between them a co-sonorous, democratic space where speech itself becomes the embodied site of political subjectivity and freedom affirmed through the sensuous act of reciprocal listening. Emerging from the rupture between their lips is a voice of “I am”, neither confined to the domestic sphere nor distanced in the guerrilla mountains, but “here”.
Mellan hemmet och bergen : Fängslade kurdiska partikvinnors vokala motstånd och sångens politik
No full textAs one of the largest demographics of political prisoners in Turkey and among the most incarcerated women politicians in the world, Kurdish women are able to share precious knowledge about anti-imperialist feminist struggle. Framed by Adriana Cavarero’s (2005) theory of vocal expression, Patricia Hill Collins’ (2000) notion of self-definition, and Saidiya Hartman’s (2019) critical fabulation of the Black chorus, I have conducted a text analysis of imprisoned Kurdish women MPs’ letters to understand how they practice a vocal resistance in contradiction to the binary economy that privileges political speech to Man and relegates Woman to silence or the maternal lullaby. Instead, this thesis argues that Kurdish party women practice a politics of song. Meaning, that the sound of the Kurdish party women’s voices communicate their uniqueness in excess of patriarchal scripts, creating in-between them a co-sonorous, democratic space where speech itself becomes the embodied site of political subjectivity and freedom affirmed through the sensuous act of reciprocal listening. Emerging from the rupture between their lips is a voice of “I am”, neither confined to the domestic sphere nor distanced in the guerrilla mountains, but “here”.
Mellan hemmet och bergen : Fängslade kurdiska partikvinnors vokala motstånd och sångens politik
No full textAs one of the largest demographics of political prisoners in Turkey and among the most incarcerated women politicians in the world, Kurdish women are able to share precious knowledge about anti-imperialist feminist struggle. Framed by Adriana Cavarero’s (2005) theory of vocal expression, Patricia Hill Collins’ (2000) notion of self-definition, and Saidiya Hartman’s (2019) critical fabulation of the Black chorus, I have conducted a text analysis of imprisoned Kurdish women MPs’ letters to understand how they practice a vocal resistance in contradiction to the binary economy that privileges political speech to Man and relegates Woman to silence or the maternal lullaby. Instead, this thesis argues that Kurdish party women practice a politics of song. Meaning, that the sound of the Kurdish party women’s voices communicate their uniqueness in excess of patriarchal scripts, creating in-between them a co-sonorous, democratic space where speech itself becomes the embodied site of political subjectivity and freedom affirmed through the sensuous act of reciprocal listening. Emerging from the rupture between their lips is a voice of “I am”, neither confined to the domestic sphere nor distanced in the guerrilla mountains, but “here”.
Studies of fluid instabilities in flows of lava and debris
No full textAt least two instabilities have been identified and utilized in lava flow studies: surface folding and gravity instability. Both lead to the development of regularly spaced structures on the surfaces of lava flows. The geometry of surface folds have been used to estimate the rheology of lava flows on other planets. One investigation's analysis assumed that lava flows have a temperature-dependent Newtonian rheology, and that the lava's viscosity decreased exponentially inward from the upper surface. The author reviews studies by other investigators on the analysis of surface folding, the analysis of Taylor instability in lava flows, and the effect of surface folding on debris flows
Lava Flow Roughness on the 2014–2015 Lava Flow-Field at Holuhraun, Iceland, Derived from Airborne LiDAR and Photogrammetry
No full textPublisher's version (útgefin grein)Roughness can be used to characterize the morphologies of a lava flow. It can be used to identify lava flow features, provide insight into eruption conditions, and link roughness pattern across a lava flow to emplacement conditions. In this study, we use both the topographic position index (TPI) and the one-dimensional Hurst exponent (H) to derive lava flow unit roughness on the 2014–2015 lava field at Holuhraun using both airborne LiDAR and photogrammetric datasets. The roughness assessment was acquired from four lava flow features: (1) spiny lava, (2) lava pond, (3) blocky surface, and (4) inflated channel. The TPI patterns on spiny lava and inflated channels show that the intermediate TPI values correspond to a small surficial slope indicating a flat and smooth surface. Lava pond is characterized by low to high TPI values and forms a wave-like pattern. Meanwhile, irregular transitions patterns from low to high TPI values indicate a rough surface that is found in blocky surface and flow margins. The surface roughness of these lava features falls within the H range of 0.30 ± 0.05 to 0.76 ± 0.04. The roughest surface is the blocky, and inflated lava flows appear to be the smoothest surface among these four lava units. In general, the Hurst exponent values in the 2014–2015 lava field at Holuhraun has a strong tendency in 0.5, both TPI and Hurst exponent successfully derive quantitative flow roughnessThe first author was supported by the Indonesia Endowment Fund for Education (LPDP) Grant
No. 20160222025516, European Network of Observatories and Research Infrastructures for Volcanology
(EUROVOLC), and Vinir Vatnajökuls during his Ph.D. project. LiDAR airborne datasets provided by The European
Facility for Airborne Research (EUFAR) and airborne photogrammetry provided by Loftmyndir ehf.Peer Reviewe
Visco-plastic models of isothermal lava domes
No full textAuthor Posting. © Cambridge University Press, 2000. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 403 (2000): 37-65, doi:10.1017/S0022112099006916.The dynamics of expanding domes of isothermal lava are studied by treating the lava as a viscoplastic material with the Herschel–Bulkley constitutive law. Thin-layer theory is developed for radially symmetric extrusions onto horizontal plates. This provides an evolution equation for the thickness of the fluid that can be used to model expanding isothermal lava domes. Numerical and analytical solutions are derived that explore the effects of yield stress, shear thinning and basal sliding on the dome evolution. The results are briefly compared with an experimental study. It is found that it is difficult to unravel the combined effects of shear thinning and yield stress; this may prove important to studies that attempt to infer yield stress from morphology of flowing lava.The financial support
of an EPSRC Advanced Fellowship is gratefully acknowledged by R.V. C. N. J. B. was partially supported by the NSF
Grant OCE-9616017 and an EPSRC Visiting Fellowship Grant GR/M50409
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