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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.
141

INHIBITED MINERALIZATION IN OSTEOBLASTS CULTURED UNDER VARIED SIMULATED PARTIAL GRAVITY CONDITIONS AND THE USE OF PHYTONUTRIENTS FOR MITIGATING THE EFFECTS OF REDUCED GRAVITY

Braveboy-Wagner, Justin, 0000-0002-6301-1394 January 2022 (has links)
The multifaceted adverse effects of reduced gravity on the skeletal system pose a significant challenge to human spaceflight. There is an interest in investigating any hypothetical differences between partial gravity and microgravity, and in the unmet need to identify countermeasures to both. A hypothesis to be tested is that reduced gravity impairs a variety of osteogenic cell functions, such as proliferation and differentiation, and that these inhibitory effects can be mitigated by nutritional countermeasures or by interrupting signaling pathways that drive undesired osteogenic remodeling. Utilizing the Random Positioning Machine, it is possible to simulate a variety of reduced gravity levels relevant to future manned space missions: Mars, Moon, and Microgravity of the Low Earth Orbit (LEO) environment. In this study, the effects of altered gravity on the physiology and morphology of cultured osteoblasts were investigated, specifically on their proliferation, osteogenic differentiation, and matrix mineralization. In assessing the role of mechanotransduction in microgravity-induced cytoskeletal dysfunction, this thesis also explored whether selective inhibition of specific signaling steps within the Rho-ROCK pathway can be used to modulate the effects of microgravity on osteoblast differentiation and function. Finally, in developing new countermeasures, an investigation was made into the effectiveness of curcumin and carnosic acid, two nutritional antioxidants with pro-osteogenic properties, contrasted with the trace element zinc, as potential alimentary supplements that may mitigate or alleviate the deleterious effects of microgravity. Results showed that short-term (6 days) culture yielded a dose-dependent reduction in proliferation and the enzymatic activity of alkaline phosphatase (ALP), while long-term studies (21 days) showed a distinct dose-dependent inhibition of mineralization. By contrast, expression levels of key osteogenic genes (Alkaline phosphatase, Runt-related Transcription Factor 2, Sparc/osteonectin) exhibited a threshold behavior: gene expression was significantly inhibited when the cells were exposed to Mars-simulating partial gravity, and this was not reduced further when the cells were cultured under simulated Moon or microgravity conditions. My data suggests that impairment of cell function with decreasing simulated gravity levels is graded and that the threshold profile observed for reduced gene expression is distinct from the dose dependence observed for cell proliferation, ALP activity, and mineral deposition. My studies into the gravity-induced re-organization of the cytoskeleton indicate that selective interruption of the Rho-ROCK pathway at ROCK can prevent morphological changes that result in impaired differentiation and mineralization. Further, I found that nutraceuticals partially reversed the inhibitory effects of SMG on ALP activity and promoted osteoblast proliferation and differentiation in the absence of traditional osteogenic media. I further observed a synergistic effect of the intermix of the phytonutrients on ALP activity. Intermixes of phytonutrients may serve as convenient and effective nutritional countermeasures against bone loss in space. / Bioengineering
142

Search for a Lunar Architecture (Designing With Modular Systems)

Bachsoliani, Lukas Wachtang January 2022 (has links)
This project explores methods to build habitats on the moon. It specifically explores the design of an interior modular system for inflatable habitats. Lunar Architecture can broadly be divided into three stages, pre-integrated, semi-integrated and built on site. Pre-integrated habitats, are fully assembled on earth and shipped with a rocket to the Moon, which has initial practicality, but constrains structure size to a rockets cargo space. Inflatable habitats fall under the semi-integrated category, which means that all the added interior volume created after inflation, will need to be built out onsite. It makes most sense to design a well-functioning modular system for this purpose, as modularity can provided the required redundancy and minimize the total amount of unique parts needed. The system needs to be lightweight, compact when stored, yet versatile enough to create flexible and engaging interiors. The project asks what a self-sufficient architecture in a lunar context would look like, if it were built with a modular approach and if it is possible to create sustainable, engaging environments through modularity.
143

Vhled / Insight

Valentová, Aneta Unknown Date (has links)
This diploma thesis Insight brings philosophical reflection on photographic media in the form of installation with video-projection in space. Issues over problems of photographic media (locked doubles, stopped time, framed imprint of reality, real raw depiction) are opening by using story about creation of picture of a rabbit on the moon in the style of open metaphors in a white room. Through this myth photographic medium gets the concrete form - in the form of symbolic environment with objets and signs. The whole work is free personification of photograph in whose inside the audience may find themselves.
144

RADIATIVE TRANSFER MODELING FOR QUANTIFYING LUNAR SURFACE MINERALS, PARTICLE SIZE AND SUBMICROSCOPIC IRON (SMFe)

Li, Shuai 16 March 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The main objective of this work is to better quantify lunar surface minerals (agglutinate, clinopyroxene, orthopyroxene, plagioclase, olivine, ilmenite, and volcanic glass), particle sizes and the abundance of SMFe from the lunar soil characterization consortium (LSCC) dataset with our improved model based on Hapke's radiative transfer theory. The model is implemented for both forward and inverse modeling. Hapke's radiative transfer theory is implemented in the inverse model means Newton's method and least squares are jointly used to solve nonlinear questions rather than commonly used look-up Table (LUT). Although the effects of temperature and surface topography are incorporated into the implementation to improve the model performance for application of lunar spacecraft data, these effects cannot be extensively addressed in the current work because of the use of lab measured reflectance data. Our forward radiative transfer model (RTM) results show that the correlation coefficients between modeled and measured spectra are over 0.99. For the inverse model, the distribution of the calculated particle sizes is all within their measured range. The range of modeled SMFe for highland samples is 0.01% - 0.5 % and for mare samples is 0.03% - 1 %. The linear trend between SMFe and ferromagnetic resonance (Is) for all the LSCC samples is consistent with laboratory measurements. For quantifying lunar mineral abundances, the results show that the R-squared for the training samples (Is/FeO <= 65) are over 0.65 with plagioclase having highest correlation (0.94) and pyroxene the lowest (0.68). In the future work, the model needs to be improved for handling more mature lunar soil samples.
145

Three Recitals of Music by German and Danish Composers, J.S. Bach, and Contemporary North American Composers, and a Lecture Recital on the Registration of Orchestral Textures in Organ Music

Haller, William P. (William Paul) 08 1900 (has links)
Four contrasting recitals were presented to fulfill the requirements for the degree Doctor of Musical Arts. The first recital contained music of miscellaneous composers. Two Preludes and Fugues by the North German Baroque composers Vincent Libeck and Dietrich Buxtehude were separated by Samuel Scheidt's Variations on the Netherlands folk song "Ach du feiner Reiter". The Brahms Chorale Prelude "0 wie selig seid ihr doch, ihr Frommen" and the Louis Vierne "Intermezzo" from the Third Symphony represented Romantic-style composition. The major work of the program was the Carl Nielsen Commotio, a large work in orchestral style. The second recital consisted completely of music by J. S. Bach. Four works of contrasting styles were presented: Concerto, Opus 3, No. 8, composed by Antonio Vivaldi and transcribed by Bach, Partita on Sie gegrisset, Jesu gtig, Sonata IV, and Fantasy and Fugue in G Minor. The third recital was the lecture recital: Registration of Orchestral Textures in Organ Music. This lecture was an attempt to deal with the contemporary problem in performance practice of registration of Romantic organ music. The trends in organ building in the twentieth century have ranged from a deeper exploration of the possibilities of the Romantic organ to the reevaluation of and rededication to principles of organ building popular in the seventeenth and eighteenth centuries.
146

Molten Regolith Electrolysis Processing for Lunar ISRU: Financial and Physics Analysis of SpaceX Starship Transportation

Harper, Cheyenne 01 January 2021 (has links)
The purpose of the following research is to explore molten regolith electrolysis (MRE) methodology for in-situ resource utilization (ISRU) of Highlands lunar regolith, to be explored during the initial Artemis missions. An analysis of potential commercial launch providers for MRE-equipment based on technology-readiness level (TRL), payload mass support, and $ USD/kg payload price is provided. SpaceX is ultimately proposed as a launch provider of MRE equipment following multi-factorial analysis, with the SpaceX Starship human landing system (HLS) variant proposed for supporting MRE payload. Finally, customers of regolith-derived oxygen, aluminum, and silicon are distinguished to form the business case for operating MRE equipment on the lunar surface.
147

Relationship Dynamics in the Films Twilight and New Moon: An Ideological Analysis

Burke, Maura Dianne 07 September 2010 (has links)
No description available.
148

Songs to the moon: a song cycle by Jake Heggie from poems by Vachel Lindsay

Redman, Carolyn E. January 2004 (has links)
No description available.
149

Young Elementary Students' Conceptual Understandings of Lunar Phases Before and After an Inquiry-Based and Technology-Enhanced Instructional Intervention

Hobson, Sally Merryman 10 December 2008 (has links)
No description available.
150

Influences of Reaction Parameters on the Product of a Geothermite Reaction: A Multi-Component Oxidation-Reduction Reaction Study

Faierson, Eric J. 29 May 2009 (has links)
This study investigated an oxidation-reduction reaction involving a mixture of minerals, glass, and aluminum that exhibited thermite-type reaction behavior. Thermite reactions are a class of Self-propagating High-temperature Synthesis (SHS) reactions. Chemical reactions between raw minerals and a reducing agent, which exhibit thermite-type reaction behavior, are termed geothermite reactions by the author. Geothermite reactions have the potential for use in In-Situ Resource Utilization (ISRU) applications on the Earth, the Moon, Mars, and beyond. A geothermite reaction was shown to occur between two particle size distributions of lunar regolith simulant. Regolith simulant is a naturally occurring mixture of minerals and glass mined from a volcanic ash deposit. The chemical composition of the simulant is similar to actual lunar regolith found on the Moon. The product of the reaction was a ceramic-composite material. The effect of reactant stoichiometry, regolith simulant particle size, and reaction environment on phase formation, microstructure, and compressive strength of the reaction product was investigated. Reaction environments used in this study included a standard atmosphere and a vacuum environment of 0.600 Torr. In addition, the energy required to initiate each reaction using various reaction parameters was measured. X-ray diffraction (XRD) analysis of reaction products synthesized in a standard atmosphere and in vacuum typically indicated the presence of the chemical species: silicon, corundum (α -Al₂O₃), spinel (MgAl₂O₄), and grossite (CaAl₄O₇). Many additional chemical species were present; their occurrence depended on reaction parameters used during synthesis. Diffraction peaks were observed for phases of aluminum nitride within all reaction products formed in a standard atmosphere. Scanning Electron Microscopy (SEM) showed the presence of whisker networks throughout the microstructure for all reactions conducted in a standard atmosphere. Energy Dispersive Spectroscopy (EDS) indicated the presence of aluminum and nitrogen within many of the whiskers. It was hypothesized that many of the whisker networks were composed of phases of aluminum nitride. No whisker networks were observed in the vacuum synthesized reaction products. Maximum mean compressive strengths were found to be ~ 18 MPa and occurred in the coarse particle size distribution of simulant using the smallest quantity of aluminum. Reactant mixtures using a coarse particle size distribution of regolith simulant were found to require substantially more energy to initiate the reaction than the simulant with the fine particle size distribution. / Master of Science

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