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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.
11

AERO|ASTRO Architecture: the hybridizing frontier of emergent industries

Yuen Fung, Jonathan Lim 22 January 2013 (has links)
Architectural designers often need to strike an uneasy balance between idealism and reality. Under most circumstances, architects are restricted by clients, budgets, and available technologies. However, divorced from traditional constraints, visionary concepts of new dwellings, new cities, and new “worlds” will spark greater forms of innovation and drive creativity for future generations. The exploration of new spatial boundaries and conceptual environments for design will irrevocably alter the human experience while adapting new challenging roles for future architects. Architecture can be understood in part as the art of organizing spaces through the manipulation of materials and forms. Designed spaces are arranged to provide unique sensory reactions for their occupants while emotionally and physically orientating them on Earth. As a catalyst towards the awareness of one’s surroundings, architecture has always had to contend with the many limiting factors imposed by the forces on Earth. These include, but are not limited to, gravity and climate. On Earth, structurally sound construction is limited by the forces of gravity as it influences design capabilities by standardizing forms, functions, and structural elements of architectural spaces. New design challenges and opportunities arrive when we look to create structures outside of Earth’s boundaries. This thesis proposes a futuristic model of an efficient and unique passenger transport system that connects Earth-based hybrid air/space ports with an outer space orbital infrastructural hub. This modern intervention will allow for new outer space industries, such as transit, tourism, and hospitality, which will provide unique opportunities for the future of humanity. Additionally, the thesis studies the positive architectural and experiential potentials for the future living occupancy of outer space. In recognizing the financial and logistical limitations of current space constructions, such as the International Space Station, the thesis looks beyond the limitations of current technologies and towards designs that are driven by the fulfillment of human experiences in space. Life in space, the thesis envisions, will spark new human experiences and rituals while necessitating new forms and designs in architecture. Weightlessness and its related spatial disorientations, in addition to the many other unique conditions in this unfamiliar territory, will inspire a new conceptual language for architecture and human cultures. The thesis will demonstrate that spaces designed for extraterrestrial experiences can be innovatively dynamic as they respond to new cultures and activities that evolve as a reaction to extreme conditions. Introducing humans to the environs of orbital space will be the initial stage in a long-term phasing tactic to colonize and commercialize beyond the expanse of Earth, eventually extending humanity to the remote neighbouring planets of the universe.
12

Astrophysical radiation environments of habitable worlds

Smith, David Samuel, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
13

An investigation of extraterrestrial radio radiation in the cygnus region at 915 megacycles per second /

Eaton, Joy Jean January 1957 (has links)
No description available.
14

The analysis of current-mirror MOSFETs for use in radiation environments

Martinez, Marino Juan, 1965- January 1988 (has links)
Experiments were conducted on current-mirror MOSFETs to examine their suitability for use in radiation environments. These devices, which allow low loss load current sensing (defined by a current-ratio n'), are an important element of many power integrated circuits (PICs). Total-dose testing demonstrated that the current ratio was virtually unaffected for many operating conditions. In all cases, changes were largest when sense resistance was largest and minimal when sense voltage was approximately equal to the load source's voltage. In addition, testing verified the feasibility of using sense-cell MOSFETs for applications which require radiation exposure. A constant-current op-amp circuit showed minimal current shifts, using proper circuit design, following total-dose exposure. Dose-rate testing showed the feasibility of using sense voltage to trigger g&d2; protection through drain-source voltage clamping, providing a relatively inexpensive alternative to voltage derating.
15

Studying the Effects of Galactic and Extragalactic Foregrounds on Cosmic Microwave Background Observations

Abitbol, Maximilian H. January 2018 (has links)
Cosmic microwave background observations have been fundamental in forming the standard model of cosmology. Ongoing and upcoming cosmic microwave background experiments aim to confirm this model and push the boundaries of our knowledge to the very first moments of the Universe. Non-cosmological microwave radiation from the Galaxy and beyond, called foregrounds, obscures and contaminates these measurements. Understanding the sources and effects of foregrounds and removing their imprint in cosmic microwave background observations is a major obstacle to making cosmological inferences. This thesis contains my work studying these foregrounds. First, I will present observations of a well-known but poorly understood foreground called anomalous microwave emission. Second, I will present results forecasting the capability of a next-generation satellite experiment to detect cosmic microwave background spectral distortions in the presence of foregrounds. Third, I will present results studying the effect of foregrounds on the cosmic microwave background self-calibration method, which allows experiments to calibrate the telescope polarization angle using the cosmic microwave background itself. Fourth, I will present my analysis characterizing the performance of and producing maps for the E and B Experiment. Fifth, I will present my research contributions to the readout system that used in the laboratory to operate kinetic inductance detectors, which are being developed for cosmic microwave background observations. Lastly, I will conclude with future prospects in the field of foregrounds and cosmic microwave background cosmology.
16

Etude d'une série de micrométéorites antarctiques : caractérisation multi-analytique et comparaison à des chondrites carbonées / Study of a series of Antarctic micrometeorites : multi-analytic characterization and comparison with carbonaceous chondrites

Battandier, Manon 17 October 2018 (has links)
L'étude des petits corps de système solaire (astéroïdes et comètes), qui se sont formés il y a 4.567 milliards d'années, nous renseigne sur les matériaux initialement présents dans la nébuleuse solaire et sur les processus opérants dans le système solaire primitif. Cette étude peut être notamment menée par l'analyse de cosmomatériaux dits primitifs, telles que des météorites (principalement les chondrites), des poussières interplanétaires (IDPs) ou encore des micrométéorites.Ce travail de thèse consiste en une multi-analyse d'une série de 58 micrométéorites antarctiques (AMMs) provenant de la collection CONCORDIA 2006 et 2016. Parmi elles, différents types texturaux reflétant les différents degrés de chauffage subi durant l'entrée atmosphérique sont représentés: 40 particules non fondues à grains fins (Fgs), 12 particules intermédiaires partiellement fondues (Fg-Scs), 1 particule partiellement fondue scoriacée (Sc) et 5 sphérules cosmiques complètement fondues (CSs). Les échantillons ont été étudiés par différentes méthodes analytiques: i) par spectroscopie Raman, permettant ici d'étudier la structure de la matière organique polyaromatique; ii) par spectroscopie IR, permettant ici d'étudier la matière organique essentiellement aliphatique ainsi que l'état d'hydratation et la minéralogie des échantillons; et 3) par spectrométrie de masse à ionisation secondaire (NanoSIMS), utilisée ici pour mesurer la composition isotopique du carbone et de l'azote de la matière organique contenue dans les AMMs. Dans le but de contraindre la diversité des corps parents échantillonnés par les cosmomatériaux, des chondrites carbonées de types 1 et 2 CM, CR et CI sont également étudiées.La combinaison des caractérisations Raman et IR a permi de mettre en évidence des différences entre les AMMs, en terme d'abondance, de structure et de composition chimique de la matière organique, de minéralogie et d'état d'hydratation. En particulier, 7 Fgs se distinguent des autres AMMs de part: i) une minéralogie hydratée avec phyllosilicates, ii) une richesse en matière organique polyaromatique et aliphatique, iii) une structure de la matière organique polyaromatique différente. Des expériences de chauffage, mises en place dans le présent travail, sur des grains de matrice de chondrites carbonées CM, CR, CI montrent que la traversée atmosphérique peut induire: la déshydratation des échantillons, une diminution de l'abondance en matière organique et une modification structurale de la matière organique polyaromatique. L'identification de 17 Fgs non hydratées montre que malgré une texture à grains fins, certaines Fgs peuvent avoir subi un chauffage significatif durant l'entrée atmosphérique. Les 7 Fgs identifiées apparaissent alors comme celles ayant été le moins modifiées par la traversée atmosphérique et sont donc les plus primitives de notre série. De plus, cette étude montre que l'état d'hydratation, la minéralogie et la matière organique sont des traceurs encore plus sensibles au chauffage subi lors de la traversée atmosphérique que la texture des micrométéorites.Des différences propres, ne s'expliquant pas par le chauffage atmosphérique, sont révélées entre les 7 Fgs hydratées et les chondrites carbonées CM, CR, CI étudiées. Ces différences sont: i) une signature spectrale spécifique des silicates en IR, ii) une richesse en matière organique aliphatique et iii) des caractérisques différentes de la matière organique aliphatique. De plus, l'analyse des compositions isotopiques du carbone et de l'azote montre une grande variabilité des rapports isotopiques parmi les AMMs contrairement aux observations dans les chondrites carbonées. Ces différences propres sont ici interprétées par l'échantillonnage de corps parents différents entre AMMs et chondrites carbonées. / The study of the Solar System's small bodies (asteroids and comets), formed 4.567 billions years ago, gives us an insight on the materials initially present in the solar nebula and on the mechanisms operating in the primitive Solar System. This study can be performed via the analysis of the so-called primitive cosmomaterials, as meteorites (mainly chondrites), interplanetary dust particles (IDPs) or even micrometeorites.This PhD thesis consists of a multi-analysis of a series of 58 Antarctic micrometeorites (AMMs) from the CONCORDIA 2006 and 2016 collections. This set of AMMs provides a large range of textural types reflecting different intensities of heating experienced during the entry in the atmosphere : 40 unmelted fine-grained particles (Fgs), 12 particles intermediate partially melted (Fg-Scs), 1 partially melted scoriaceous particle (Sc) and 5 completely melted cosmic spherules (CSs). To study these samples, I used different analytical methods : i) Raman spectroscopy, to study the structure of the polyaromatic organic matter; ii) infrared (IR) spectroscopy, to analyze the aliphatic organic matter as well as the hydration state and the mineralogy of these samples; and iii) nanoscale secondary ion mass spectroscopy (NanoSIMS) to measure the isotopic composition of carbon and nitrogen of the organic matter contained in the AMMs. In order to constrain the diversity of parent bodies sampled by cosmomaterials, I also studied type 1 and 2 CM, CR and CI carbonaceous chondrites.The combination of Raman and IR techniques reveals differences among AMMs in terms of abundance, structure and chemical composition of the organic matter, mineralogy and hydration state. In particular, 7 Fgs distinguishing themselves from others AMMs as they show : i) a hydrated mineralogy with phyllosilicates, ii) an abundance in polyaromatic and aliphatic organic matter and iii) structural differences in the polyaromatic organic matter. Heating laboratory experiments, on CM, CR and CI carbonaceous chondrite matrices show that the atmospheric entry can induce : a dehydration of the samples, a drop in the abundance of organic material and a structural modification of polyaromatic organic matter. The identification of 17 non-hydrated Fgs reveals that, in spite of their fined-grained texture, some Fgsmay have experienced significant heating during their entry in the atmosphere. The 7 identified Fgs then appears as the ones that were the least affected by the atmospheric entry and thus the most primitive of our series. Moreover, this study shows that the hydration state, the mineralogy and the organic matter are more sensitive tracers to heating experienced during the atmospheric entry than the texture of micrometeorites.Intrinsic differences, which cannot be explained by the atmospheric entry, are also revealed between the 7 hydrated Fgs and CM, CR and CI chondrites. These differences are : i) a specific spectral signature of silicates in IR, ii) an abundance in organic and aliphatic material and iii) different characteristics of the aliphatic organic matter. Moreover, the analysis of the isotopic composition of carbon and nitrogen shows large variabilities among AMMs, in opposition with observations among carbonaceous chondrites. These intrinsic differences are explained here as AMMs and carbonaceous chondrites sampling distinct parent bodies.
17

Rotating Magnetometry For Terrestrial And Extraterrestrial Subsurface Explorations

Farrell, Robert 01 January 2018 (has links)
Signaling and sensing with rotating magnet sources have both Terrestrial and Extraterrestrial applications. The dual spinning magnet unit presented in this paper is a simple, lightweight solution to help understand soil densities and locate water and ice pockets, for example, on Mars. Traditional magnetic telemetry systems that use energy-inefficient large induction coils and antennas as sources and receivers are not practical for extraterrestrial and remote field sensing applications. The recent proliferation of strong rare-earth permanent magnets and high-sensitivity magnetometers enables alternative magnetic telemetry system concepts with significantly more compact formats and lower energy consumption. There are also terrestrial applications, for example, subterranean objects such as underground infrastructure and unexploded ordnances (UXO) that are often unmapped and difficult to find on Earth. Current ground penetrating radar units are expensive, large, and heavy. The research presented explores the viability and possibility to develop a unit that will induce an oscillating magnetic field with controllable shape to reliably locate buried ferromagnetic and non-ferromagnetic objects while remaining lightweight and cost effective. A Dual Rotating Magnet (DRM) design is presented. Experiments and numerical simulations assess the system for terrestrial and extraterrestrial detection of: 1) differences in soil densities, 2) water and ice pockets at shallow depths in the subsurface, and 3) subterranean ferromagnetic and non-ferromagnetic objects of interest.
18

Electrohydrodynamic enhancement of extraterrestrial capilliary pumped loops for nuclear applications

Lipchitz, Adam 01 December 2010 (has links)
This work examines electrohydrodynamic enhancement of capillary pump loops (CPL) for use in extraterrestrial nuclear applications. A capillary pump uses capillary action through a porous wick to transport heat and mass. The capillary pump is being considered as a method to improve heat transport in extraterrestrial nuclear applications. The work consists of a literature review of electrohydrodynamics, capillary pumped loops and space type nuclear reactors. Current CPLs are assessed for their performance and several design solutions are investigated using theoretical and analytical techniques. Experimental analysis is performed on an electrohydrodynamic gas pump to determine their suitability for implementation into the vapour leg of a capillary pump loop. The results suggest the EHD gas pumps could offer improved performance and it is recommended experiments should be performed in future work with an EHD gas pump in a CPL for verification. A new design for the electrohydrodynamic evaporator is also developed for enhanced performance. / UOIT
19

A Configurable Terasample-per-second Imaging System for Optical SETI

Mead, Curtis Charles 08 October 2013 (has links)
A new instrument for conducting astronomical searches for nanosecond-scale optical pulses has been designed, built, and is now operating at Oak Ridge Observatory in Harvard, MA. The Advanced All-sky Camera, based on the previous generation ASIC-based design, is implemented using Xilinx Virtex-5 LX110 FPGAs to create a flexible and configurable system. Each FPGA has 32 1.5 Gsps analog-to-digital converters, implemented as 8-level flash ADCs using 256 of the Virtex-5's LVDS input pairs. Thirty-two FPGAs in the system total 1024 ADC channels, each with 8kB of sample memory, for triggering on and recording coincident pulse waveforms from an array of 1024 photomultiplier tube anodes. / Engineering and Applied Sciences
20

Exopolitika a problém bezpečnosti v 21. století / Exopolitics and Security in the 21. Century

Zelinka, Ladislav January 2013 (has links)
The thesis introduces a new field of social sciences, the exopolitics, and poses a question, whether extra-terrestial intelligence constitutes a threat to security. The problem is discussed through analysis of primary data, which are in particular these: official documents, studies, letters, memoranda, witnesses' testimonies, official statements and other reliable evidence. Theoreticaly I refer to the existing exopolitical literature, mainly of M. Salla, and two selected papers. The aim is to show that the exopolitical study is actual, legitimate and well-founded and deserves more attention and credit. The thesis wishes to give an inspiring appeal to promote further study of the field through academia and other educational institutions.

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