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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.
91

Effects of microhabitat and temporal factors on foraging behavior of white-footed mice (Peromyscus leucopus)

Jacob, Suellen A. 18 September 2012 (has links)
No description available.
92

The Higher Learning

Thompson, Alison 11 January 2016 (has links)
No description available.
93

Wishing on the Moon

Hung, Tsun-Hui 27 September 2007 (has links)
No description available.
94

A Novel Architecture for Supply-Regulated Voltage-Controlled Oscillators

Chakravarty, Anu 15 January 2010 (has links)
No description available.
95

Moon base: ad lunam

Voelcker, Ana Carolina January 2023 (has links)
The Moon is the closest celestial body to us. It is also the one we know most about, the only one we have visited so far, and our constant companion. With NASA's new Artemis program and newfound interest in exploring the Moon and beyond, my proposal is to create a base on the Moon for further space exploration, scientific development and establishment of an extraterrestrial colony. Dealing with obstacles such as lack of resources, radiation and no atmosphere, my project combines different constructive strategies, such as 3D-printing, excavating and inflatable membranes, to create an environment where humans can live and thrive on the Moon. The habitat allows for performing experiments and engaging in the basic survival activities, but also creates a home in such a challenging and distant place. Creating varied layers of habitability and protection ensure for a productive and entertaining existence on our one and only satellite, paving way to further explore the Solar System.
96

The motion of a lunar satellite under the influence of the moons noncentral force field

Tolson, Robert Heath January 1963 (has links)
For lunar satellites within a few hundred miles of the lunar surface the primary cause of disturbance from pure Keplerian motion is the disturbing force due to the moon's noncentral gravitational field which, unlike the earth's field, is unsymmetrical and rotating. This thesis presents a first-order approximation to the motion of lunar satellites under the forces resulting from this field. The results are a set of equations which give the short period, long period and secular variations of a slightly modified set of Delauney elements. A typical set of orbital characteristics are utilized to obtain an estimate of the order of magnitude of the variations in the various elements. / Master of Science
97

La croûte lunaire : étude de la composition et de l’organisation de la croûte lunaire avec les données spectroscopiques de l’instrument Moon Mineralogy Mapper / The lunar crust : a study of the lunar crust composition and organisation with spectroscopic data from the Moon Mineralogy Mapper

Martinot, Mélissa 07 October 2019 (has links)
Au cours des cinquante dernières années, notre niveau de connaissance sur la Lune a fortement évolué. Les progrès en science lunaire sont survenus selon plusieurs phases. La première phase eut lieu pendant les missions Apollo et Luna dans les années 1960 et 1970, avec l’étude des échantillons de roches lunaires rapportées pendant les missions du même nom. La caractérisation pétrologique des échantillons lunaires a fait naître le concept d’Océan de Magma Lunaire, qui est à l’origine de la vue traditionnelle de la croûte et du manteau lunaires. Ce modèle prédit que la croûte lunaire est riche en plagioclase et que sa composition devient plus mafique en profondeur. Il est communément admis que le manteau lunaire est riche en olivine et qu’il contient du pyroxène, conformément au manteau terrestre. La seconde phase de l’exploration lunaire eut lieu dans les années 1990, lorsque des satellites lancés en orbite lunaire collectèrent les premiers jeux de données globaux de télédétection. En raison de leur couverture spatiale globale, les données de télédétection apportèrent une vision complémentaire à celle conférée par l’étude des échantillons lunaires. Pendant la troisième phase de l’exploration lunaire, qui a commencé dans les années 2000 et a toujours cours aujourd’hui, de nouveaux jeux de données ont été collectés par des satellites en orbite autour de la Lune. Les données de télédétection acquises durant ces deux dernières phases ont permis de prendre connaissance de processus complexes encore inconnus et de nuancer l’image initialement simple que les scientifiques se faisaient de la Lune. En effet, l’étude des jeux de données de haute résolution et des données radar a conduit à l’identification d’édifices volcaniques (dômes ; zones de mare irrégulières, dites irregular mare patches ou IMP), et à la découverte sans équivoque de volatils dans les régions ombragées en permanence. Des volatils ont également été découverts dans des échantillons lunaires issus de l’intérieur de la Lune, démontrant ainsi la complexité de l’histoire géologique de la Lune.Durant cette thèse, des cratères d’impact ont été utilisés comme forages naturels de la croûte lunaire. En effet, lors de l’impact, des roches profondes sont excavées et mises à l’affleurement dans le pic central du cratère par rebond élastique. Il est alors possible d’étudier la composition des roches crustales profondes en examinant le pic central d’un cratère à la surface d’une planète. Ici, le pic central de cratères échantillonnant la croûte lunaire a été étudié avec les données spectroscopiques de l’instrument Moon Mineralogy Mapper (Cartographe de la Minéralogie de la Lune, aussi noté M³) à bord de la mission Chandrayaan-1. Ce travail illustre l’utilisation de données de télédétection sur le pic central de cratères, dans l’optique de caractériser l’intérieur peu profond de la Lune. Les données de télédétection peuvent également être utilisées pour aider à cibler des régions à la surface de la Lune dont le retour d’échantillons pourrait donner des indices importants sur l’organisation de la croûte et du manteau supérieur lunaires / Over the past 50 years, our knowledge of the Moon has grown immensely. Progress in lunar science occurred through several phases. The first phase happened in the 1960s and 70s, during the Apollo and Luna missions, with the study of samples returned from the lunar surface. Petrological characterisation of lunar samples sparked the Lunar Magma Ocean concept, from which ensued the traditional view of the lunar crust and mantle organisation: the crust is plagioclase-rich, and its mafic content increases with increasing depth. The lunar mantle is commonly thought to be olivine-rich, like that of the Earth. The second lunar exploration phase happened in the 1990s, when satellites were launched into lunar orbit, collecting the first global remote sensing datasets. Owing to their wide to global coverage, remote sensing brought new insight into lunar science that is complementary to that provided by lunar samples. During the third, current phase of lunar exploration, new datasets were collected by spacecrafts orbiting the Moon between the 2000s and today. The remote sensing datasets acquired during the second and third phases of lunar exploration progressively complicated the initially simple picture that scientists drew from earlier studies. Indeed, high resolution remote sensing images and radar data led to the identification of volcanic features (domes, irregular mare patches), and the unambiguous discovery of volatiles in permanently shadowed regions and in lunar samples originating at depth in the Moon, demonstrating the Moon’s complex geological history. During this PhD, impact craters were used as natural drill holes through the lunar crust to sample material located underneath the surface. During impact, rocks from depth are emplaced in crater central peaks through elastic rebound, making it possible to investigate the composition of the crust at depth. Spectroscopic data from Chandrayaan-1’s Moon Mineralogy Mapper instrument were exploited to gather information on the composition of the crust in those central peaks. This work illustrates the use of remote sensing data on crater central peaks in order to constrain the shallow interior of the Moon. Remote sensing data can also be used to help locate which type of samples would need to be returned in the future from the lunar surface, in order to contribute to further elucidating the organisation of the lunar crust and upper mantle
98

Transfer design methodology between neighborhoods of planetary moons in the circular restricted three-body problem

David Canales Garcia (11812925) 19 December 2021 (has links)
<div>There is an increasing interest in future space missions devoted to the exploration of key moons in the Solar system. These many different missions may involve libration point orbits as well as trajectories that satisfy different endgames in the vicinities of the moons. To this end, an efficient design strategy to produce low-energy transfers between the vicinities of adjacent moons of a planetary system is introduced that leverages the dynamics in these multi-body systems. Such a design strategy is denoted as the moon-to-moon analytical transfer (MMAT) method. It consists of a general methodology for transfer design between the vicinities of the moons in any given system within the context of the circular restricted three-body problem, useful regardless of the orbital planes in which the moons reside. A simplified model enables analytical constraints to efficiently determine the feasibility of a transfer between two different moons moving in the vicinity of a common planet. Subsequently, the strategy builds moon-to-moon transfers based on invariant manifold and transit orbits exploiting some analytical techniques. The strategy is applicable for direct as well as indirect transfers that satisfy the analytical constraints. The transition of the transfers into higher-fidelity ephemeris models confirms the validity of the MMAT method as a fast tool to provide possible transfer options between two consecutive moons. </div><div> </div><div>The current work includes sample applications of transfers between different orbits and planetary systems. The method is efficient and identifies optimal solutions. However, for certain orbital geometries, the direct transfer cannot be constructed because the invariant manifolds do not intersect (due to their mutual inclination, distance, and/or orbital phase). To overcome this difficulty, specific strategies are proposed that introduce intermediate Keplerian arcs and additional impulsive maneuvers to bridge the gaps between trajectories that connect any two moons. The updated techniques are based on the same analytical methods as the original MMAT concept. Therefore, they preserve the optimality of the previous methodology. The basic strategy and the significant additions are demonstrated through a number of applications for transfer scenarios of different types in the Galilean, Uranian, Saturnian and Martian systems. Results are compared with the traditional Lambert arcs. The propellant and time-performance for the transfers are also illustrated and discussed. As far as the exploration of Phobos and Deimos is concerned, a specific design framework that generates transfer trajectories between the Martian moons while leveraging resonant orbits is also introduced. Mars-Deimos resonant orbits that offer repeated flybys of Deimos and arrive at Mars-Phobos libration point orbits are investigated, and a nominal mission scenario with transfer trajectories connecting the two is presented. The MMAT method is used to select the appropriate resonant orbits, and the associated impulsive transfer costs are analyzed. The trajectory concepts are also validated in a higher-fidelity ephemeris model.</div><div> </div><div>Finally, an efficient and general design strategy for transfers between planetary moons that fulfill specific requirements is also included. In particular, the strategy leverages Finite-Time Lyapunov Exponent (FTLE) maps within the context of the MMAT scheme. Incorporating these two techniques enables direct transfers between moons that offer a wide variety of trajectory patterns and endgames designed in the circular restricted three-body problem, such as temporary captures, transits, takeoffs and landings. The technique is applicable to several mission scenarios. Additionally, an efficient strategy that aids in the design of tour missions that involve impulsive transfers between three moons located in their true orbital planes is also included. The result is a computationally efficient technique that allows three-moon tours designed within the context of the circular restricted three-body problem. The method is demonstrated for a Ganymede->Europa->Io tour.</div>
99

Improvement and use of radiative transfer models to assess lunar space weathering and mechanisms for swirl formation

Liu, Dawei 15 June 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This dissertation focuses on quantification of submicroscopic iron of different sizes, mineral abundance and grain size of lunar soils using Hapke's radiative transfer model. The main objective is to explore implications of these results for assessing the relative importance of solar wind implantation versus micrometeorite impacts for lunar space weathering as well as three hypotheses (solar wind deflection, comet impact and dust transport) for swirl formation on the Moon. Results from this study can help to make connections between ordinary chondritic meteorites and asteroids, and put physical and chemical constraints on heating processes in the early solar system.
100

The Powerpuff Girls vs. Sailor Moon : En jämförelse av två animerade barnprograms underliggande diskurser / The Powerpuff Girls vs. Sailor Moon

Lörtscher, Yasmin January 2014 (has links)
This study is about underlying discourses of two tv-series for children from opposite parts of the globe. Focus lays on which morals and values adults choose to teach children through popular culture, even on an unaware basis and how does differ, or not, between different societies. The theoretical framework chosen for this study are semiotics in combination with the concept of the gaze by Laura Mulvey. Semiotics is the study of signs and their underlying meanings constructed by society. By studying popular culture with the tools provided by semiotic analysis it is possible to discouver underlying myths, social constructions of society, that are reproduced over and over again to remain alive. Mulveys theory of the gaze is helpfull in the process of decoding those constructions to discover the dominant partys and norms represented. In this particular study underlying structures such as patriarcal power relations, unequality between the representation of different ethnicities and the consistent presents of the male gaze where discovered. The conclusions made are that some social constructions are more global then others and that popular culture in a high degree mirrors societies norms, preferences and values.

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