A drawbar pull (DP) test procedure was developed at the NASA Glenn Research Center (GRC) for testing and developing designs for off-road vehicles. The motivation was to develop a procedure that would produce repeatable results and could be replicated by other researchers. While developing the test methodology, it became apparent that there was a certain degree of scatter in the results among identical tests. In order to characterize the disparities, an experimental study was conducted consisting of systematically varying specific test parameters. The selected performance metric was the DP-TR (travel reduction) relation. The selected parameters were: 1) the starting terrain condition, 2) the distance traveled by the vehicle under an applied, constant DP force, and 3) the density of the prepared terrain. Respectively, these parameters were selected to observe: 1) how differences in the starting area, or "launch pad," would affect the resulting performance of a test, 2) if a steady-state region of performance exists and how does performance change with the distance traveled, and 3) the relationship between prepared terrain density and performance. These experiments were conducted in a dry, granular, cohesionless, silica based soil called the GRC-1 Lunar Soil Simulant. The results of these studies were that the variations in both the starting terrain condition and the distance traveled did not significantly affect performance. The relationship between performance and terrain density was that only in a region of low density was the TR constant; subsequently, the TR decreased steadily with increasing density. / Master of Science

Recently there is an increase in interest in the Moon as a destination for space missions. This increased interest is in the composition and geography of the Moon as well as using the Moon to travel beyond the Earth to other planets in the solar system. This thesis explores the mechanics behind a lunar mission and the costs and benefits of different approaches. To constrain this problem, the launch criteria are those of Wallops Flight Facility (WFF), which has expressed interest in launching small spacecraft to the Moon for exploration and study of the lunar surface. The flight from the Earth to the Moon and subsequent lunar orbits, referred to hereafter as the mission, is broken up into three different phases: first the launch and parking orbit around the Earth, second the transfer orbit, and finally the lunar capture and orbit. A launch from WFF constrains the direction of the launch and the possible initial parking orbits. Recently WFF has been offered the use of a Taurus XL launch vehicle whose specifications will be used for all other limitations of the launch and initial parking orbit. The orbit investigated in this part of the mission is a simple circular orbit with limited disturbances. These disturbances are only a major factor for long duration orbits and don't affect the parking orbit significantly. The transfer orbit from the Earth to the Moon is the most complex and interesting part of the mission. To fully describe the dynamics of the Earth-Moon system a three-body model is used. The model is a restricted three-body problem keeping the Earth and Moon orbiting circularly around the system barycenter. This model allows the spacecraft to experience the influence of the Earth and Moon during the entire transfer orbit, making the simulation more closely related to what will actually happen rather than what a patched conic solution would give. This trajectory is examined using Newtonian, Lagrangian, and Hamiltonian mechanics along with using a rotating and non-rotating frame of reference for the equations of motion. The objective of the transfer orbit is to reduce the time and fuel cost of the mission as well as allow for various insertion angles to the Moon. The final phase of the mission is the lunar orbit and the analysis also uses a simple two body model similar to the parking orbit. The analysis investigates how the orbits around the Moon evolve and decay and explores more than just circular orbits, but orbits with different eccentricities. The non-uniform lunar gravity field is investigated to accurately model the lunar orbit. These factors give a proper simulation of what happens to the craft for the duration of the lunar orbit. Tracking the changes in the orbit gives a description of where it will be and how much of the lunar surface it can observe without any active changes to the orbit. The analysis allows for either pursuing a long duration sustained orbit or a more interesting orbit that covers more of the lunar surface. These three phases are numerically simulated using MATLAB, which is a focus of this thesis. In all parts of the mission the simulations are refined and optimized to reduce the time of the simulation. Also this refinement gives a more accurate portrayal of what would really happen in orbit. This reduction in time is necessary to allow for many different orbits and scenarios to be investigated without using an unreasonable amount of time. / Master of Science

This analysis examines Jane Eyre and Wide Sargasso Sea through the lens of lunar imagery and the irrational feminine, arguing that both texts are aspects of an extended, collective narrative in which both heroines rescue and reclaim their feminine essence from the construction of a masculine idealism.

A resposta da fauna à fragmentação e perda de hábitat pode variar amplamente segundo os requerimentos ecológicos, a configuração da paisagem, a conectividade e as pressões antrópicas. Os morcegos são bons candidatos para trabalhar os efeitos da fragmentação na fauna mas, mesmo assim, existem poucos estudos a respeito da diversidade dos morcegos frugívoros e sua dieta em áreas de cerrado do estado de São Paulo e nas demais áreas de cerrado do país, tendo em conta que este bioma vem sofrendo processos de mudança muito rápidos nas últimas décadas. Assim, vimos a importância de incorporar este grupo de fauna nos estudos que tem sido desenvolvidos na região. Durante 48 dias de coleta ao longo de um ano (2012), procurou-se inventariar a quiropterofauna de dois fragmentos de Cerrado correspondentes à Estação Ecológica de Jataí e ao Cerrado Pé-do-Gigante, nos municípios de Luiz Antônio e Santa Rita do Passa Quatro, localizados ao noroeste do Estado de São Paulo, sendo amostradas fisionomias diferentes: cerradão, cerrado sensu stricto, cerrado adensado e cerrado em estado de regeneração. Foram realizadas duas coletas mensais, de 4 horas cada, iniciadas após o pôr do sol, totalizando 24 amostragens em cada unidade de conservação. Os morcegos foram coletados com redes de neblina situadas a 50 cm do solo, em trilhas preexistentes e em áreas abertas, e identificados em nível de espécie. Outros dados ecológicos, como frequência, dominância, riqueza, constância, horário de atividade, dieta, dispersão de sementes através das fezes dos indivíduos capturados e a influência da luminosidade lunar foram analisados. Foram capturados e anilhados 195 indivíduos de 3 famílias e 7 subfamílias, pertencentes a 17 espécies diferentes, sendo 113 na estação chuvosa e 82 na estação seca. Na E.E. Jataí foram capturados 118 indivíduos de 15 espécies e, no Cerrado Pé-do-Gigante, 77 indivíduos, de 13 espécies, com um esforço amostral de de 31680 m². O índice de Shannon-Wiener apresentou uma diferencia sutil entre a diversidade de espécies em ambas as unidades de Conservação, constatada também pelo alto índice de similaridade de Sorensen (0,75). Obtiveram-se 5 recapturas, uma delas confirmando o fluxo entre unidades de conservação. As espécies dominantes foram: Artibeus lituratus, Anoura caudifer, Sturnira lilium, Glossophaga soricina e Carollia perspicillata. Com relação à dispersão de sementes, obtiveram-se 39 amostras de fezes, das quais 11 continham sementes que posteriormente foram germinadas em laboratório, obtendo-se assim 9 espécies de plantas petencentes a 4 gêneros, potencialmente dispersadas pela quiropterofauna local / The response of wildlife to fragmentation and habitat loss may vary widely according to the ecological requirements, landscape configuration, connectivity among landscape units, and anthropogenic pressures. Bats are ideal species to study fragmentation effects on wildlife, however, studies on the diversity of frugivore bats and their diet in savanna biomes are scarce, despite the intense changes linked to human pressures this biome has been recently submitted to. Therefore, we considered relevant to incorporate the evaluation of the regional bat assembly to fauna studies in Cerrado areas of São Paulo state. During a period of 48 days, representative of both rainy and dry seasons of 2012, we surveyed chiropterofauna in two Cerrado fragments, in the northwestern Sao Paulo state: Jataí Ecological Station (Luiz Antônio municipality) and Cerrado Pé-do-Gigante (Santa Rita de Passa-Quatro municipality). These units show different physiognomies: cerradão, cerrado sensu stricto, dense cerrado and cerrado in regeneration. The surveys were carried out under two nights per month in each conservation area. Bats were collected using mist nets located 50 cm above ground in existing trails in open areas. A total of 195 individuals belonging to 3 families, 7 subfamilies and 17 species were captured and ringed: 113 of these during the rainy season and the remaining 82 during dry season. In E.E. Jataí we registered 118 individuals belonging to 15 species, and in Cerrado Pé-do-Gigante, 77 individuals from 13 species (31680 m² of mist net in the two fragments of Cerrado). Most of the individuals recorded during the study belong to 5 species: Artibeuslituratus, Anoura caudifer, Sturnira Lilium, Glossophaga soricina and Carollia perspicillata. In relation to seed dispersion, 39 fecal samples were obtained, of these, 11 contained seeds that later were germinated in laboratory, obtaining nine species of plants of 4 geners potentiality dispersed by the local bats

A linear covariance analysis is conducted to assess closed-loop guidance, navigation, and control system (GN&C) performance of the Altair vehicle during lunar powered descent. Guidance algorithms designed for lunar landing are presented and incorporated into the closed-loop covariance equations. Navigation-based event triggering is also included in the covariance formulation to trigger maneuvers and control dispersions. Several navigation and guidance trade studies are presented demonstrating the influence of triggering and guidance and study parameters on the vehicle GN&C performance.

Shadow shielding is a novel and practical concept for waste heat rejection from lunar surface spacecraft systems. A shadow shield is a light shield that shades the radiator from parasitic thermal radiation emanating from the sun or lunar surface. Radiator size and mass can reduce if the radiator is not required to account for parasitic heat loads in addition to system energy rejection requirements. The lunar thermal environment can be very harsh towards radiative heat rejection. Parasitic heat loads force the radiator to expand in size and mass to compensate. On the Moon, there are three types: surface infrared, solar insulation, and albedo. This thesis tests shadow shielding geometry and its effect on the radiator and nuclear reactor in a reactor-powered Carnot heat engine. Due to the nature of cooling by radiative heat transfer, the maximum shaft work a Carnot system can produce and the minimal required radiator area occurs when the Carnot efficiency is 25%. First, a case for shadow shielding is made using an isothermal, control radiator model in Thermal Desktop. Six radiator temperatures and three latitudes are considered in the tests. Test variables in this section include radiator shapes and shade geometry. The simulations found that shadow shielding is best suited for a low-temperature radiator at the lunar equator. Optimized parabolic shade geometry includes a focus right above or at the top of the radiator and full to three-quarters shade height. The most useful rectangular radiator shape for shadow shielding is that which has a low height and long width. All simulations were conducted using a shade with a 10 kg/m2 area mass. A sensitivity study was conducted for different shade area masses using high and low values found in the literature. The shade is the most useful when the shade's area mass is less than or equal to that of the radiator. If the shade mass is below this threshold, the shade would be applicable to all radiator temperatures tested. Optimized shade and radiator geometry results were then factored into a second model where the radiator is comprised of heat pipes which is similar to radiators from actual system designs. Further simulations were conducted implementing the SAFE-4001 fast fission nuclear reactor design. The study found that shadow shielding allowed the system to use a low-temperature radiator where other configurations were not viable because shadow shielding drastically improves radiative heat transfer from the radiator, but at the consequence of raising radiator mass.

The nervous systems of animals evolved to exert dynamic control of behavior in response to the needs of the animal and changing signals from the environment. To understand the mechanisms of dynamic control, we need a means of predicting how individual neural and body elements will interact to produce the performance of the entire system. We have developed a neuromechanical application named AnimatLab that addresses this problem through simulation. A computational model of a body and nervous system can be constructed from simple components and situated in a virtual world for testing. Simulations and live experiments were used to investigate questions about locust jumping. The neural circuitry and biomechanics of kicking in locusts have been extensively studied. It has been hypothesized that the same neural circuit and biomechanics governed both behaviors, but this hypothesis was not testable with current technology. We built a neuromechanical model to test this and to gain a better understanding of the role of the semi-lunar process (SLP) in jump dynamics. The SLP are bands of cuticle that store energy for use during jumping. The results of the model were compared to a variety of published data and were similar. The SLP significantly increased jump distance, power, total energy, and duration of the jump impulse. Locust can jump precisely to a target, but also exhibit tumbling. We proposed two mechanisms for controlling tumbling during the jump. The first was that locusts adjust the pitch of their body prior to the jump to move the center of mass closer to the thrust vector. The second was that contraction of the abdominal muscles during the jump produced torques that countered the torque due to thrust. There was a strong correlation relating increased pitch and takeoff angle. In simulations there was an optimal pitch-takeoff combination that minimized tumbling that was similar to the live data. The direction and magnitude of tumbling could be controlled by adjusting abdominal tension. Tumbling also influenced jump elevation. Neuromechanical simulation addressed problems that would be difficult to examine using traditional physiological approaches. It is a powerful tool for understanding the neural basis of behavior.

In January 2005, President Bush announced the Vision for Space Exploration. This vision involved a progressive expansion of human capabilities beyond Low Earth Orbit beginning with a return to the moon no later than 2020. Current design processes utilized to meet this vision employ performance based trade studies to determine the lowest cost, highest reliability solution. The methodology implemented in this dissertation focuses on a concurrent evaluation of the performance, cost, and reliabilities of lunar architectures. This process directly addresses the top level requirements early in the design process and allows the decision maker to evaluate the highest reliability, lowest cost lunar architectures without being distracted by the performance details of the architecture. To achieve this methodology of bringing optimal cost and reliability solutions to the decision maker, parametric performance, cost, and reliability models are created to model each vehicle element. These models were combined using multidisciplinary optimization techniques and response surface equations to create parametric vehicle models which quickly evaluate the performance, reliability, and cost of the vehicles. These parametric models, known as ROSETTA models, combined with a life cycle cost calculator provide the tools necessary to create a lunar architecture simulation. The integration of the tools into an integrated framework that can quickly and accurately evaluate the lunar architectures is presented. This lunar architecture selection tool is verified and validated against the Apollo and ESAS lunar architectures. The results of this lunar architecture selection tool are then combined into a Pareto frontier to guide the decision maker to producing the highest reliability architecture for a given life cycle cost. With this presented methodology, the decision maker can transparently choose a lunar architecture solution based upon the high level design discriminators. This method can achieve significant reductions in life cycle costs (over 40%) keeping the same architecture reliability as a traditional design process. This methodology also allows the decision maker to choose a solution which achieves a significant reduction in failure rate (over 50%) while maintaining the same life cycle costs as the point solution of a traditional design process.

abstract: Several short term exogenic forcings affecting Earth's climate are but recently identified. Lunar nutation periodicity has implications for numerical meteorological prediction. Abrupt shifts in solar wind bulk velocity, particle density, and polarity exhibit correlation with terrestrial hemispheric vorticity changes, cyclonic strengthening and the intensification of baroclinic disturbances. Galactic Cosmic ray induced tropospheric ionization modifies cloud microphysics, and modulates the global electric circuit. This dissertation is constructed around three research questions: (1): What are the biweekly declination effects of lunar gravitation upon the troposphere? (2): How do United States severe weather reports correlate with heliospheric current sheet crossings? and (3): How does cloud cover spatially and temporally vary with galactic cosmic rays? Study 1 findings show spatial consistency concerning lunar declination extremes upon Rossby longwaves. Due to the influence of Rossby longwaves on synoptic scale circulation, our results could theoretically extend numerical meteorological forecasting. Study 2 results indicate a preference for violent tornadoes to occur prior to a HCS crossing. Violent tornadoes (EF3+) are 10% more probable to occur near, and 4% less probable immediately after a HCS crossing. The distribution of hail and damaging wind reports do not mirror this pattern. Polarity is critical for the effect. Study 3 results confirm anticorrelation between solar flux and low-level marine-layer cloud cover, but indicate substantial regional variability between cloud cover altitude and GCRs. Ultimately, this dissertation serves to extend short term meteorological forecasting, enhance climatological modeling and through analysis of severe violent weather and heliospheric events, protect property and save lives. / Dissertation/Thesis / Ph.D. Geography 2013

A resposta da fauna à fragmentação e perda de hábitat pode variar amplamente segundo os requerimentos ecológicos, a configuração da paisagem, a conectividade e as pressões antrópicas. Os morcegos são bons candidatos para trabalhar os efeitos da fragmentação na fauna mas, mesmo assim, existem poucos estudos a respeito da diversidade dos morcegos frugívoros e sua dieta em áreas de cerrado do estado de São Paulo e nas demais áreas de cerrado do país, tendo em conta que este bioma vem sofrendo processos de mudança muito rápidos nas últimas décadas. Assim, vimos a importância de incorporar este grupo de fauna nos estudos que tem sido desenvolvidos na região. Durante 48 dias de coleta ao longo de um ano (2012), procurou-se inventariar a quiropterofauna de dois fragmentos de Cerrado correspondentes à Estação Ecológica de Jataí e ao Cerrado Pé-do-Gigante, nos municípios de Luiz Antônio e Santa Rita do Passa Quatro, localizados ao noroeste do Estado de São Paulo, sendo amostradas fisionomias diferentes: cerradão, cerrado sensu stricto, cerrado adensado e cerrado em estado de regeneração. Foram realizadas duas coletas mensais, de 4 horas cada, iniciadas após o pôr do sol, totalizando 24 amostragens em cada unidade de conservação. Os morcegos foram coletados com redes de neblina situadas a 50 cm do solo, em trilhas preexistentes e em áreas abertas, e identificados em nível de espécie. Outros dados ecológicos, como frequência, dominância, riqueza, constância, horário de atividade, dieta, dispersão de sementes através das fezes dos indivíduos capturados e a influência da luminosidade lunar foram analisados. Foram capturados e anilhados 195 indivíduos de 3 famílias e 7 subfamílias, pertencentes a 17 espécies diferentes, sendo 113 na estação chuvosa e 82 na estação seca. Na E.E. Jataí foram capturados 118 indivíduos de 15 espécies e, no Cerrado Pé-do-Gigante, 77 indivíduos, de 13 espécies, com um esforço amostral de de 31680 m². O índice de Shannon-Wiener apresentou uma diferencia sutil entre a diversidade de espécies em ambas as unidades de Conservação, constatada também pelo alto índice de similaridade de Sorensen (0,75). Obtiveram-se 5 recapturas, uma delas confirmando o fluxo entre unidades de conservação. As espécies dominantes foram: Artibeus lituratus, Anoura caudifer, Sturnira lilium, Glossophaga soricina e Carollia perspicillata. Com relação à dispersão de sementes, obtiveram-se 39 amostras de fezes, das quais 11 continham sementes que posteriormente foram germinadas em laboratório, obtendo-se assim 9 espécies de plantas petencentes a 4 gêneros, potencialmente dispersadas pela quiropterofauna local / The response of wildlife to fragmentation and habitat loss may vary widely according to the ecological requirements, landscape configuration, connectivity among landscape units, and anthropogenic pressures. Bats are ideal species to study fragmentation effects on wildlife, however, studies on the diversity of frugivore bats and their diet in savanna biomes are scarce, despite the intense changes linked to human pressures this biome has been recently submitted to. Therefore, we considered relevant to incorporate the evaluation of the regional bat assembly to fauna studies in Cerrado areas of São Paulo state. During a period of 48 days, representative of both rainy and dry seasons of 2012, we surveyed chiropterofauna in two Cerrado fragments, in the northwestern Sao Paulo state: Jataí Ecological Station (Luiz Antônio municipality) and Cerrado Pé-do-Gigante (Santa Rita de Passa-Quatro municipality). These units show different physiognomies: cerradão, cerrado sensu stricto, dense cerrado and cerrado in regeneration. The surveys were carried out under two nights per month in each conservation area. Bats were collected using mist nets located 50 cm above ground in existing trails in open areas. A total of 195 individuals belonging to 3 families, 7 subfamilies and 17 species were captured and ringed: 113 of these during the rainy season and the remaining 82 during dry season. In E.E. Jataí we registered 118 individuals belonging to 15 species, and in Cerrado Pé-do-Gigante, 77 individuals from 13 species (31680 m² of mist net in the two fragments of Cerrado). Most of the individuals recorded during the study belong to 5 species: Artibeuslituratus, Anoura caudifer, Sturnira Lilium, Glossophaga soricina and Carollia perspicillata. In relation to seed dispersion, 39 fecal samples were obtained, of these, 11 contained seeds that later were germinated in laboratory, obtaining nine species of plants of 4 geners potentiality dispersed by the local bats