A Numerical Treatment of Melt/Solid Segregation: Size of the Eucrite Parent Body and Stability of the Terrestrial Low-Velocity Zone

Crystal sinking to form cumulates and melt percolation toward segregation in magma pools can be treated with modifications of Stokes' and Darcy's laws, respectively. The velocity of crystals and melt depends, among other things, on the force of gravity (g) driving the separations and the cooling time of the environment. The increase of g promotes more efficient differentiation, whereas the increase of cooling rate limits the extent to which crystals and liquid can separate. The rate at which separation occurs is strongly dependent on the proportion of liquid that is present. As a result, cumulate formation is a process with a negative feedback; the more densely aggregated the crystals become, the slower the process can proceed. In contrast, melt accumulation is a process with a positive feedback; partial accumulation of melt leads to more rapid accumulation of subsequent melt. This positive feedback can cause melt accumulation to run rapidly to completion once a critical stability limit is passed. The observation of cumulates and segregated melts among the eucrite meteorites is used as a basis for calculating the g (and planet size) required to perform these differentiations. The eucrite parent body was probably at least 10-100 km in radius. The earth's low velocity zone (LVZ) is shown to be unstable with respect to draining itself of excess melt if the melt forms an interconnecting network. A geologically persistent LVZ with a homogeneous distribution of melt can be maintained with melt fractions only on the order of 0.1% or less

Expository Text Structure and Student Learning

Upper elementary teachers may wonder why some of their students with no history of comprehension problems suddenly struggle with understanding their social studies, science and health texts. These teachers might correctly point to the more difficult concepts presented in these texts and to the more technical vocabulary that their students will now encounter. Yet these factors are only part of the problem that students face when they move from stories to content material

Mohawk

David Hays Denney is a college student at the University of Arkansas as a Creative Writing major. He is interested in pursuing a career in screenwriting and enjoys writing poetry and prose. As an Eagle Scout, he is interested in nature and the outdoors, which often influences his work

Protecting Research: Copyright, Common-Law Alternatives, and Federal Preemption

Under federal copyright law, an author\u27s expression is protected but his ideas and discoveries are not. Professor Shipley explores the possibility of expanding copyright to protect the research of nonfiction authors, but concludes that such an expansion would undermine federal copyright policy. State-law remedies exist that will provide such protection if they are not preempted by federal law. Professor Shipley concludes that most contract claims and some misappropriation claims will survive preemption and therefore are a means by which nonfiction authors can protect their research

PARTY WITH THE COURT: POLITICAL PARTIES AND THE NATIONAL JUDICIARY IN THE CREATION, MAINTENANCE, AND TRANSFORMATION OF POLITICAL ORDERS

In the United States, the national judiciary plays a vital role in the creation, maintenance, and transformation of political orders. Political parties, the institutions primarily responsible for the operation of a political order, tend to be large and heterogeneous. This heterogeneity creates disjunction within the party and threatens to undermine partisan unity. In order to hold power over an extended period of time, parties-in-power must diffuse their intra-party tension. This dissertation explores the phenomena of parties using courts to diffuse intra-party tension by displacing highly divisive issues onto the national judiciary. This exploration reveals a pattern whereby the dominant wing of the party-in-power consistently secures its preferences through the courts to the detriment of minority wing preferences. To elucidate this pattern, three different political orders are examined. First, the Republican political order is examined to reveal how the dominant, conservative wing of the Party used the courts to protect against invasive regulatory schemes favored by the progressive, minority wing of the Party. Second, an examination of the New Deal/Great Society Democratic political order reveals the role the courts played in enabling the liberal, dominant wing of the Party to circumvent conservative, minority wing obstruction of civil rights and how the courts helped liberal Democrats woo African American voters so as to transform and liberalize the Democratic Party. Third, the period of divided government is detailed to reveal how the dominant, economically conservative wing of the Republican Party uses the Supreme Court to manage issues highly salient to the socially conservative minority wing. Judicial administration of religion in education, homosexual rights, and abortion resulted in the Republican Party eschewing those issues from its legislative agenda and, simultaneously, resulted in center-left policy consistent with dominant wing preferences. By judicializing social issues, the Republican Party created greater Party unity than what would otherwise be possible, which enabled it to rise to power at the turn of the 21st Century. The party-court dynamic has implications for judicial power, party government, and constitutional theory and each are explored in the conclusion

Knowing and Not Knowing, Moving and Not Moving, in Alain Resnais’s L’Année dernière à Marienbad (1961)

Selon le critique et théoricien du cinéma André Bazin, la photographie “tire avantage” de son aspect mécanique, à savoir le processus par lequel chaque objet donne forme à sa propre représentation. C’est ainsi que les photographies et autres médias indexicaux, y compris les films, opèrent la jonction entre le passé et le présent et ont en cela un pouvoir étrangement inquiétant. Dans le film d’Alain Resnais, L’Année dernière à Marienbad (1961), la photographie présente un intérêt particulier du fait de la relation que ces éléments entretiennent avec le trauma. La protagoniste est traumatisée en découvrant une photo d’elle-même, ce qui brouille les frontières entre mémoire et perception et la place, non pas dans l’incertitude, mais à la croisée du savoir et du non-savoir. De manière similaire, la reconstruction mémorielle et les blocages hantent Marienbad en mettant en évidence le paradoxe cinématographique du mouvement et de l’absence de mouvement. Des formes de corps humain sont mises en miroir à l’écran dans des prises de vue où évoluent d’autres éléments visuels, et les comédiens mettent en scène cet effet de temps suspendu en se figeant tels des statues, comme s’ils étaient pétrifiés. À travers ces procédés, et avec à l’esprit l’idée de transformer le cinéma, Resnais testait la relation entre représentation, histoire, et corps humain, exploration déjà menée dans ses films précédents. Dans le film Marienbad, les deux paradoxes pertinents pour cette réflexion – le savoir et le non-savoir, le mouvement et le non-mouvement – se chevauchent dans le plan emblématique, très près du milieu du film, dans lequel la caméra s’avance pour révéler neuf silhouettes qui se tiennent dans l’axe “vide” d’un jardin à la française et dont l’agencement énigmatique correspond à la conception type du jardin japonais : le jardin de la méditation à Ryoan-ji, temple zen important de Kyoto, au Japon.According to film theorist and critic André Bazin, photography “derives an advantage” from its mechanical aspect: the process through which each object gives form to its own representation. In that way, photographs and other indexical media, including films, bridge past and present and have uncanny power. In Alain Resnais’s film L’Année dernière à Marienbad (1961), photography is of special interest because of how those aspects relate to trauma. Confronting a photograph of herself traumatizes the principal female character, blurring the distinction between memory and perception and locating her not in uncertainty but at the intersection of knowing and not knowing. In a related way, editing and blocking haunt Marienbad by making evident the filmic paradox of moving and not moving. Forms of the human body are graphically matched across cuts in which other visual elements change, and performers stage the time freeze effect by holding their positions like statues or as if frozen. In those ways, the body develops a reputation for stability and coherence usually reserved for filmic space but here denied to it. Through such devices, and with an eye to transforming cinema, Resnais tested the relationship among representation, history, and the human body, an exploration sustained throughout his early films. In Marienbad, the two paradoxes pertinent to that interest — knowing and not knowing, moving and not moving — overlap in the iconic shot near the film’s midpoint, in which the camera advances to reveal nine figures standing in the “empty” axis of a French-style garden and arranged enigmatically following a paragon of Japanese garden design: the meditation garden at Ryoan-ji, an important Zen temple in Kyoto, Japan

Studies toward dioxirane mediated catalytic asymmetric epoxidations of olefins

Thesis (B.S.) in Chemistry--University of Illinois at Urbana-Champaign, 1992.Includes bibliographical references (leaves 35-36)Microfiche of typescript. [Urbana, Ill.]: Photographic Services, University of Illinois, U of I Library, [1992]. 2 microfiches (41 frames): negative.s 1992 ilu n

Pterodactyl: Thermal Protection System for Integrated Control Design of a Mechanically Deployed Entry Vehicle

The need for precision landing of high mass payloads on Mars and the return of sensitive samples from other planetary bodies to specific locations on Earth is driving the development of an innovative NASA technology referred to as the Deployable Entry Vehicle (DEV). A DEV has the potential to deliver an equivalent science payload with a stowed diameter 3 to 4 times smaller than a traditional rigid capsule configuration. However, the DEV design does not easily lend itself to traditional methods of directional control. The NASA Space Technology Mission Directorate (STMD)s Pterodactyl project is currently investigating the effectiveness of three different Guidance and Control (G&C) systems actuated flaps, Center of Gravity (CG) or mass movement, and Reaction Control System (RCS) for use with a DEV using the Adaptable, Deployable, Entry, and Placement Technology (ADEPT) design. This paper details the Thermal Protection System (TPS) design and associated mass estimation efforts for each of the G&C systems. TPS is needed for the nose cap of the DEV and the flaps of the actuated flap control system. The development of a TPS selection, sizing, and mass estimation method designed to deal with the varying requirements for the G&C options throughout the trajectory is presented. The paper discusses the methods used to i) obtain heating environments throughout the trajectory with respect to the chosen control system and resulting geometry; ii) determine a suitable TPS material; iii) produce TPS thickness estimations; and, iv) determine the final TPS mass estimation based on TPS thickness, vehicle control system, vehicle structure, and vehicle payload

Dive performance in a small-bodied, semi-aquatic mammal in the wild

Aquatic foraging is a fundamental component of the behavior of a number of small mammals, yet comprehensive observations of diving are often difficult to obtain under natural circumstances. Semiaquatic mammals, having evolved to exploit prey in both aquatic and terrestrial environments, are generally not as well adapted for diving (or for life in the water) as are fully aquatic species. Because dive ability also tends to increase with body size, small, semiaquatic mammals are presumed to have fairly limited dive ability. Nevertheless, diving plays an important role in food acquisition for many such species. We used time–depth recorders (TDRs) to measure and describe the dive performance of 9 female and 5 male free-living American mink (Neovison vison; body mass approximately 1 kg) on lowland rivers in the southern United Kingdom. We recorded dives up to 2.96 m deep (maximum depth X ¯ 5 1.82 m) and up to 57.9 s in duration (maximum duration X ¯ 5 37.2 s). Dive duration was approximately 40% of that predicted by allometry for all air-breathing diving vertebrates (as might be expected for a small, semiaquatic animal) but was twice as long as previously measured for mink in captivity. Mink performed up to 189 dives per day (X ¯ 5 35.7 dives/day), mostly during daylight, and spent a maximum of 38.4 minutes diving per day (X ¯ 5 7.6 min/day). Some individuals maintained particularly high diving rates over the coldest months, suggesting that the benefits of aquatic foraging in winter outweigh the costs of heat loss. We observed a number of very shallow dives (depth approximately 0.3 m) of particularly long duration (up to 30 s). The function of these dives is currently unknown, but possibilities include searching for prey, travelling, or avoidance of threats. There is only 1 other study of which we are aware that presents detailed measurements of dive performance in a small, shallow-diving, semiaquatic mammal.Fil: Harrington, Lauren. University of Oxford; Reino UnidoFil: Hays, Graeme C.. Swansea University; Reino UnidoFil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Harrington, Andrew L.. University of Oxford; Reino UnidoFil: Righton, David. No especifíca;Fil: Macdonald, David W.. University of Oxford; Reino Unid