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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

THE EXPERIMENTAL PARTITIONING BEHAVIOR OF TUNGSTEN AND PHOSPHORUS: IMPLICATIONS FOR THE COMPOSITION AND FORMATION OF THE EARTH, MOON AND EUCRITE PARENT BODY.

NEWSOM, HORTON ELWOOD. January 1982 (has links)
The solid-metal/silicate-melt partition coefficient for W has been determined experimentally for the temperature and oxygen fugacity conditions at which eucritic basalts formed. The partition coefficient for W is 25 ± 5 at 1190°C and an oxygen fugacity of 10⁻¹³∙⁴. The solid-metal/silicate-melt partition coefficient for P, D(P), has been determined experimentally at 1190°C and 1300°C. The dependence of the partition coefficient on oxygen fugacity is consistent with a valence state of 5 for P in the silicate melt. The experimental partition coefficients are given by: (1) log D(P) = -1.21 log fO₂ -15.95 at 1190°C (2) log D(P) = -1.53 log fO₂ -17.73 at 1300°C The partition coefficients may be used to interpret the depletion of W/La and P/La ratios in the Earth, Moon, and eucrites relative to Cl chondrites. The depletion of the W/La ratios in the eucrites may be explained by partitioning of W into 2% to 10% solid metal assuming equilibration and separation of the metal from the silicates at low degrees of partial melting of the silicates. The depletion of P/La ratios requires an additional 5% to 25% sulfur-bearing metallic liquid. The depletion of both P/La and W/La ratios in the Moon can be explained by partitioning of P and W into liquid metal during formation of a small lunar core by metal-silicate separation at low degrees of partial melting of the silicates. The W/La ratios in the Earth and Moon are virtually indistinguishable, while P/La ratios differ by a factor of two. The concentrations of FeO also appear to be different. These observations are difficult to reconcile with the hypothesis of a terrestrial origin of the Moon following formation of the Earth's core, but are consistent with an independent formation of the Earth and Moon. In contrast to the Moon and eucrites, the depletion of P/La and W/La ratios in the Earth cannot be explained by an internally consistent model involving equilibrium between metal and silicate at low pressures.
102

The silicon isotopic composition of inner Solar System materials

Armytage, Rosalind M. G. January 2011 (has links)
This study uses high precision silicon isotopic measurements to understand events that occurred during the earliest stages of formation of the terrestrial planets. The isotopic compositions of diverse materials such as chondrites, lunar rocks and asteroidal basalts can shed light on the homogeneity of the solar nebula, metal-silicate differentiation on planetary bodies, and terrestrial moon formation. Limited variation in the Si isotopic composition of meteorites is evidence for a relatively homogeneous inner solar system with respect to silicon isotopes. The Si isotopic composition of bulk silicate Earth (BSE) is, however, heavier than meteorites. This points to an event unique to Earth that fractionated Si isotopes, such as core formation at terrestrial conditions. The Δ<sup>30</sup>Si<sub>BSE-meteorite</sub> value from this study indicates that the Earth’s core contains 8.7 (+8.1/−6.2) wt% Si. No systematic δ<sup>30</sup>Si differences were found between any of the lunar lithologies analysed, implying a Si isotopic homogeneity of the sampled lunar source regions. The lunar average, δ<sup>30</sup>Si = −0.29±0.08permil (2σ<sub>SD</sub>), is identical to the recent value of Savage et al. (2010) for BSE of δ<sup>30</sup>Si = −0.29 ± 0.08permil (2σ<sub>SD</sub>). The best explanation of the data is that Si isotopes must have homogenised in the aftermath of the Moon-forming impact with no subsequent fractionation in the proto-lunar disk. The Si isotopic composition of olivine within lunar basalts was found to be the same or heavier than δ<sup>30</sup>Si(pyroxene). This is not consistent with terrestrial data where δ<sup>30</sup>Si(pyroxene) is always lighter than δ<sup>30</sup>Si(olivine). Crystallisation history cannot explain the data, and the slow diffusion rates of Si rule out cooling rates as a cause. Therefore, it appears that inter-mineral fractionation of Si isotopes occurs differently on the Moon. The δ<sup>30</sup>Si of chondrules picked from Allende spanned a range of ~0.6permil, a factor of two greater than the bulk meteorite range. There is no evidence for the variable δ30Si of the chondrules being the result of post-formation alteration and there is no convincing evidence for precursor heterogeneity being the primary cause. It is likely that Si isotopic composition of chondrules is the result of evaporation and reequilibration with the evaporated phase.
103

Measurement of properties of the lunar surface using the Diviner Lunar Radiometer experiment on the NASA Lunar Reconnaissance Orbiter

Thomas, Ian Richard January 2011 (has links)
The Diviner Lunar Radiometer is a nine-channel radiometer on board the Lunar Reconnaissance Orbiter, launched in June 2009 and currently orbiting the Moon. Diviner is the first orbiting multi-spectral instrument to observe the lunar surface in the mid- and far- infrared, therefore this thesis details the first steps towards utilising observations in this new spectral region. The author, as part of the Diviner instrument team, contributed to the pre-launch testing and calibration of Diviner. Specifically, the transmission profiles of the B2 and B3 filters, which could not be measured after integration into the instrument due to their long wavelength passbands, were determined. Further investigations of the far-infrared mesh filters were also conducted, as the spectral responses of similar mesh filters were found to have broadened after integration into the Mars Climate Sounder instrument, the pre-cursor instrument to Diviner. To test if this would occur in Diviner also, a new setup was made to approximately re-create the instruments' optical layout. No such spectral broadening was measured in the B1, B2 or B3 filters. The linearities of Diviner's detectors were also confirmed through analysis of the pre-flight calibration data. Laboratory emission spectra taken under ambient conditions differ from those taken in a lunar environment, which induces a temperature gradient in soil and mineral samples. Due to a lack of spectra measured under such conditions, which are directly comparable to Diviner‟s measurements, a new chamber for performing high-resolution emission measurements in a simulated lunar environment was built and calibrated. This setup induces a temperature gradient in each sample by heating it from below while it is surrounded by a cooled radiation shield, all enclosed in a very low pressure vacuum chamber. Lunar analogue minerals have been measured, first in reflectance, and then in simulated lunar conditions, forming the basis of a new lunar spectral library. The uses of the mid- and far-infrared have been described herein, utilising calibrated Diviner observations to: [1] map the temperatures of the lunar poles; [2] investigate regions containing higher than average abundances of rocks; and [3] determine the composition of regions of the lunar surface by combining observations with the new spectral library made during this project.
104

Science et fiction dans trois récits de voyage sur la Lune

Dupuis-Plamondon, Alexandre January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
105

A Post-Communist Picnic

Sheng, Yi 01 January 2010 (has links)
Signaling the moon, packing balls of mud, carving a big sphere, cleaning with a giant unwieldy mop, playing with indigo, wrangling cardboard, setting sunflowers ablaze, playing a tune with a soda bottle, taking a walk with other people’s laundry, kindling smoke signals, weaving a bed, cracking seeds all night, listening to sleep, dressing a plant, these are some of the activities that have been incorporated into my work over the last two years. Most ideas begin in the studio and then are realized outside. Many of the tasks mentioned allow me to easily integrate into a crowd, where the project and I go unnoticed and remain indistinguishable from the buzz of day to day life. Other projects however, have been done with more consideration for its secrecy. The narratives that are incorporated in this thesis, both personal and culled from research, attempt to unpack some of the fleeting yet conceptually interwoven curiosities that have propelled me to search for these experiences.
106

Apollo - člověk na Měsíci / Apollo - the man on the Moon

Švancara, Marek January 2011 (has links)
The aim of this study is to outline circumstances and reasons which caused a birth of an ambitious plan which enabled the USA to land a man on the Moon and return him safely to the Earth. The impact of this thesis is to chart individual pilot expeditions also from the eyes of real participants. One part of this study is a chapter dealing with astronauts' preparation and training. The thesis also reminds the fact that among people who landed on the Moon was also the astronaut of the Czech origin, Eugene A. Cernan. In the end the study deal with technology that helped to include program Apollo among the greatest events of the 20th century.
107

Modelování intenzity slunečního záření pro místa měsíčních základen / Modeling of solar irradiance for lunar base locations

Čašek, Jakub January 2014 (has links)
Modeling of solar irradiance for lunar base locations Abstract An incident radiation is an essential factor for a discovery of a place suitable for building a lunar base. This thesis presents a new approach for modeling of solar irradiance in an arbitrary lunar location at selected time. Shadowing by surrounding terrain is calculated by spatial intersection between lines of illumination and digital terrain model. Model also takes variable distance between Moon and Sun and areal representation of the Sun into account. In this thesis a new geometrical procedure for calculation of reflected irradiance is designed. The resulting model is implemented within ArcGIS software as an executable script, which utilizes the freely available data from Lunar Reconnaissance Orbiter as an input. Key words: Moon, solar irradiance, geoinformatic modelling, scripting
108

Representation of moon phases : a textbook analysis and case study of Grade 8 learners understanding

Bhulana, Lubabalo Albert 05 March 2014 (has links)
The aim of the study was to investigate the quality of diagrams and explanations of moon phases in grade 6 to 8 Natural Science textbooks; to establish whether the textbooks provide scientifically correct content information for learners and teachers and to investigate whether the textbooks used for teaching are effective conceptual development tools for grade 8 learners, specifically when exploring moon phases. The research consisted of two phases, where the first phase investigated the quality of textbooks, and the second phase investigating learners’ ideas about moon phases.
109

FACES DO FEMININO SAGRADO: O ARQUÉTIPO DA MULHER SELVAGEM / Faces of the sacred feminine: the archetype of the wild woman.

Martins, Camila Alves 15 December 2006 (has links)
Made available in DSpace on 2016-07-27T13:49:20Z (GMT). No. of bitstreams: 1 CAMILA ALVES MARTINS.pdf: 834302 bytes, checksum: 35370a532ae830dce2772d41bbd2759f (MD5) Previous issue date: 2006-12-15 / The images of the sacred feminine are erased in face of male power. The search for an integrative space between the feminine and the masculine principles becomes necessary because of the manifestation of the sacred that inhabits each one. This is a theoretical and qualitative work that considers three aspects of an analogy between the archetype of the Wild Woman , the mythical figure of Lilith and the biblical character of Maria Magdalena. In the historical aspect of the mythical reports we notice a demonized image of these women and a diminishment of their shine as sacred manifestations, due to the annulment of the integrating space of each one. The Wild Woman IS WHAT SHE IS, and belongs to herself. The danger of the wild lies in the negation of her feminine power. The symbolic movement occurs when the woman touches her corporality, and her feminine power to generate and nurture encompasses the experience of becoming one-in-herself. These experiences mould her vase-body and recreate new forms of integration. Lilith and Maria Magdalena find divine wisdom in the wild and in nature, and teach us to come into contact with our lunar aspects. In the androgyny, through the encounter between the feminine and masculine poles, re-creation/resurrection blows life into the aspects that need restoration, composing the truth and wisdom of its sacred space. Meeting the wolf gives light to obscure aspects and brings consciousness to the path of knowledge of the soul. This is the point where the female divinities were demonized, renounced and confined to the obscure side of their dark moons. / As imagens do feminino sagrado encontram-se apagadas diante da formação do poderio masculino, por isso, a busca de um espaço de integração entre o princípio feminino e o masculino se faz necessária. O trabalho é uma pesquisa teórica e qualitativa dividida em três capítulos que retrata uma analogia entre o arquétipo da Mulher Selvagem , a figura mítica de Lilith, e a personagem bíblica de Maria Madalena. Na historicidade dos relatos míticos percebemos uma imagem demonizada das mulheres e um apaguizamento do seu brilho devido ao anulamento do espaço integrador de cada uma. A Mulher Selvagem é O QUE É e pertence a si própria. O perigo do selvagem encontra-se na negação de seu poder. O movimento simbólico ocorre quando a mulher toca sua corporalidade, e quando seu poder feminino de gerar e nutrir abrange as experiências de tornar-se uma-em-si-mesma. Estas experiências moldam o seu Vaso-corpo e recriam novas formas de integração. Lilith e Maria Madalena encontram no selvagem e na sua essência, a sabedoria divina, e nos ensinam a entrar em contato com nossos aspectos lunares. Na androginia, a recriação/ ressurreição sopra vida nos aspectos que necessitam de restauração, compondo a verdade e a sabedoria de seu espaço sagrado através da integração das polaridades femininas e masculinas. O encontro da Mulher Selvagem traz luz aos aspectos obscuros, clarificando a consciência no caminho do conhecimento da alma. Neste ponto é que as divindades femininas foram demonizadas, negadas e confinadas ao lado obscuro de suas luas negras.
110

A systems analysis of space industrialization

Akin, D. L. (David L.) January 1981 (has links)
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1981. / Microfiche copy available in Archives and Barker. / Includes bibliographical references. / by David L. Akin. / Sc.D.

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