Global ETD Search

171	NASA på Nya äventyr i rymden : Populariseringen av den amerikanska visionen om rymden Nord, Johan January 2008 (has links) <p>The purpose of this thesis is to bring forward and discuss the American vision for space exploration found at NASA's homepage, how the vision is popularised and why. NASA's homepage is analyzed as popularized science and the theoretical perspective emanates from the field of popular science and especially the work of Johan Kärnfelt. The historical reference is made up by Howard E McCurdy and he's thoughts about space and the American imagination. The analysis is based on a number of documents that popularize the vision for space exploration and is intended for the public. These documents describe the future plan for NASA and US space exploration.</p> / <p>Syftet med denna uppsats är att undersöka hur de amerikanska rymdvisionerna gestaltats på NASA:s hemsida, hur dessa populariseras samt vilka de bakomliggande drivkrafterna kan tänkas vara. NASA:s hemsida kommer att ses som populariserad vetenskap och det teoretiska perspektivet utgår från den populärvetenskapliga genren där en stor del av det teoretiska underlaget utgår från docenten Johan Kärnfelts tankar om populariseringen av vetenskap. Som historisk referens används professor Howard E. McCurdys tankar om den amerikanska rymdvisionen. Materialet som ingår i analysen är hämtat från NASA:s hemsida. Samtliga dokument handlar om den amerikanska visionen om rymden och USA:s fortsatta aktiviteter i rymden.</p> Space NASA Rymdresor Kalla kriget Race to the Moon kapplöpning månen Utforskning Kolonisering The Frontier Kreationsmyten The American Creation myth Space program Howard E McCurdy Michael Godhe Rymden Populärvetenskap USA Visionen om rymden New Vision for Space Exploration Space and the American Imagination George W Bush Kulturarv och kulturproduktion
172	Pekskärmar i turbulenta miljöer : I vilken utsträckning kan precision upprätthållas / Touchscreens in turbulent conditions : To what extent is precision possible Eriksson, Alexander January 2013 (has links) Pekskärmar används i allt större utsträckning som interaktionsteknik för hemelektronik. Tekniken har traditionellt sett inte använts i krävande miljöer, exempelvis i miljöer där skakningar och g-laster förekommer. Introduktionen av pekskärmsteknologi i cockpitmiljö får konsekvenser för utformningen av förarmiljön vilka bör utredas. Denna studie syftade till att empiriskt utvärdera användarnas prestation med avseende på precision vid olika interaktionsmanövrar på en pekskärm. Fyra försök genomfördes med 14 försöksdeltagare i en simulerad miljö där olika grader av skakningar förekom. Precisionsmätningar genomfördes i samband med försöken och försöksdeltagarnas subjektivt upplevda arbetsbelastning mättes med hjälp av NASAs självskattningsformulär för upplevd arbetsbelastning (TLX). Korrelationsanalyser genomfördes mellan försöksdeltagarnas subjektiva arbetsbelastning och data från försöken. Det genomfördes också differensanalyser mellan försökens olika betingelser för att se om det förekom någon inlärningseffekt. Testresultaten visar att relativt god precision går att uppnå vid interaktion med pekskärm men att vissa typer av interaktion är svårare och skattas högre med avseende på arbetsbelastning än andra. Resultatet från en inledande workshop med förare och ingenjörer visar på en positiv inställning till pekskärmar som komplement till inmatning i cockpit. Rapporten ger rekommendationer för utformningen av gränssnitt för pekskärm för att undvika interaktionsproblem vid skakningar och g-laster. / Touchscreens are a common occurrence in everyday applications these days. The technology is not traditionally used in high hazard environments, in example where vibrations and G-forces is frequently occurring. The consequences of introducing touchscreens to the cockpit environment are something to consider when designing the pilot environment. The purpose of this study is to empirically evaluate the user performance and precision when interacting with touchscreens. Four tests were conducted with 14 trial participants in a semi-controlled environment where varying degrees of vibrations occurred. Measurements of the participants’ precision were measured together with a subjective workload measure developed by NASA (TLX). Correlation analyses were carried out between the experimental participants’ subjective workload and data from the experiments. The difference in precision and performance was also analysed between the precision tests to see if there was any learning effects. The test results show that good precision was possible to some extent but that some types of interaction is more difficult then others hence increasing workload for the participants. The results of an initial workshop with pilots and engineers show a positive attitude towards touchscreens as complement for the currently available input methods. The report provides recommendations for the design of touchscreen interfaces to avoid issues caused by shaking and g-loads. Aviation Aeronautics Turbulent conditions Interaction Precision Touchscreen interaction Touchscreens Workload Erconomics Human machine interaction HMI Human factors Flyg Flygteknik Pekskärmar turbulent miljö Interaktion Precision Pekskärm Pekskärmsinteraktion NASA-TLX Arbetsbelastning Ergonomi Människa teknik interaktion människa teknik organisation HMI MTO Human Computer Interaction
173	Nitrogen Tetroxide to Mixed Oxides of Nitrogen: History, Usage, Synthesis, and Composition Determination Andrew W Head (11181636) 22 November 2021 (has links) <div>Since as early as the 1920s, dinitrogen tetroxide (N2O4) has been regarded as a promising oxidizer in rocket propulsion systems. In more recent times, its predecessor, mixed oxides of nitrogen (MON), remains a top contender among oxidizers, due to its unique characteristics such as low freezing temperature and compatibility with common spacecraft materials. Today, these N2O4-based oxidizers are the preferred choice in many upper stages, launch escape systems, reaction control systems, liquid apogee engines, and in-space primary propulsion systems. N2O4-based oxidizers are a key factor in rocket propulsion, and thoroughly understanding their history, development, characteristics, synthesis, and composition analysis are crucial for space exploration today and into the future.<br><br></div><div>To fully understand and predict the physical properties of a MON sample, it is important to measure and quantify its chemical composition. The recommended method for MON composition analysis, as prescribed by the Department of Defense’s Defense Specification (MIL-SPEC) document on N2O4, involves the oxidation of NO and dinitrogen trioxide (N2O3) in the MON sample to determine their amounts. An equation unofficially called the “MIL-SPEC equation” is then used to determine the amount of NO needed to mix with N2O4 to synthesize that particular MON sample. However, no explanation is given as to how the equation was derived, or its significance.<br><br></div><div>This thesis aims to collect and organize key information on the synthesis, handling, and composition analysis of MON propellant. First, the history of development of N2O4-based oxidizers was researched, and current and future uses of N2O4 and MON propellants were identified. Then a method for synthesis and composition analysis was devised and tested. Water contamination was expected of skewing the results, so the process of water contamination was examined analytically. Then a detailed derivation of the MIL-SPEC equation was conducted, to fully understand its mechanics. An attempt was then made to reverse-engineer an unexplained numerical value in the equation, labeled by the author as the “solubility factor”. Several derivations were provided with varying degrees of complexity, producing alternative solubility factors of varying accuracies. Finally, experimental data was applied to these derived, hypothetical solubility factors and the MIL-SPEC solubility factor, with the intent of determining whether improvements could be made to the MON composition determination process.<br><br></div><div>The results suggest that the MIL-SPEC equation is sufficient for providing a relatively accurate measurement of the composition of a MON sample, while also being easy to implement, both in taking the necessary measurements and in conducting the numerical calculation. However, some minor adjustments to the equation could produce consistently more accurate composition measurements without adding any more difficulty or complication.</div> Aerospace Engineering rocket propellant oxidizer nitrogen dinitrogen tetroxide nitric oxide mixed oxides MON NTO N2O4 mixed oxides of nitrogen nitrogen tetroxide dinitrogen tetroxide nitric oxide NO2 space propulsion spacecraft astronautics aerospace engineering missile launch history synthesis composition equation derivation NASA Department of Defense Air Force freezing point corrosion solubility oxidation MIL-SPEC military specification
174	Critical perspectives: North Sea offshore wind farms. : Oral histories, aesthetics and selected legal frameworks relating to the North Sea. / Kritiska perspektiv: vindkraftparker i Nordsjön : Muntlig historia, estetik och utvalda rättsliga ramar relaterade till Nordsjön Moss, Joanne January 2021 (has links) The study is developed from five in-depth interviews with individuals from different walks of life who have interacted significantly with the North Sea. The study discusses change in the North Sea specifically in the development of fixed turbine wind farms and their physical and aesthetic effects. Observations speakers make as to changes in the North Sea and as to its beauty are contextualised and discussed using NASA satellite images, photographs and review of available academic literature, UK policy documents and law. This context includes a study of the industrialised North Sea with reference to the sediment sea plumes behind monopile turbines. The United Kingdom was selected for particular study of its wind farm development permissions process, including evaluations of seascape and the requirement of independence for expert evidence. Decline of trawler access to the North Sea is referenced to wind farm growth, and to adverse changes in public opinion leading to closure of the UK Dogger Bank to trawlers. Finality of wind farm development decisions is considered against the prospect of overturn by the courts. This aspect covers the application and development of principles relating to appeal by way of judicial review in the UK jurisdictions of Scotland, England and Wales, and Northern Ireland. The study identifies, and explains the English aesthetic evaluation of wind farms. It concludes that sea plumes are the result of a legal choice to allow permit applications to succeed without testing by reference to detailed in-sea turbine dimensions. In the permissions process (a) sea plumes are not evaluated by the seascape criteria applicable to coastal or off-coastal wind farms (b) deep offshore wind farms are instead evaluated by possible changes to character of the sea. The study further concludes that (i) the open horizon of the North Sea has been lost in significant part (ii) the combined aesthetic of transience, decay, and nostalgia underlies the aesthetic of the North Sea Maunsell forts (contrasted to Sealand), and also underlies attitudes to decommissioning wind farms, and (iii) concepts of sea beauty may be based on appearance or health, being regulated by different legal regimes in each eventuality (respectively the European Landscape Convention, or the OSPAR/ biodiversity/ habitat initiatives) Aesthetics Coastal Decay Decommission Development permission European Landscape Convention Fluid dynamics Horizon Industrial Judicial review Marine management Maunsell Monopile NASA North Sea Offshore Oral history OSPAR Scotland Scour Sealand Sea plumes Seascape Sediment SPM Suspended particulate matter Transience Trawler Turbine United Kingdom Wind farm. Other Humanities not elsewhere specified Övrig annan humaniora
175	A Case Study of NASA's Columbia Tragedy: An Organizational Learning and Sensemaking Approach to Organizational Crisis. James, Eric Preston 12 1900 (has links) No other government agency receives as much attention as the National Aeronautics and Space Administration (NASA). The high-profile agency frequently captures attention of the media in both positive and negative contexts. This thesis takes a case study approach using organizational learning and sensemaking theories to investigate crisis communication within NASA's 2003 Columbia tragedy. Eight participants, who in some capacity had worked for NASA during the Columbia tragedy in a communication centered position, were interviewed. Using a grounded theory framework, nine themes emerged pertaining to organizational learning, leadership, structure, and organizational culture. The results of the study aid in understanding how high risk organization's (HROs) can learn from previous failures and details how organizational culture can hinder organizational change. organizational culture Organizational communication organizational learning sensemaking NASA Columbia (Spacecraft) -- Accidents. Organizational behavior -- Case studies. Corporate culture -- Case studies.
176	Veil of Protection: Operation Paperclip and the Contrasting Fates of Wernher von Braun and Arthur Rudolph Eldridge-Nelson, Allison 05 December 2017 (has links) No description available. Ethics History International Relations Military History American History World History Public Policy Operation Paperclip NASA World War II Cold War Soviet Union Germany slave labor Nazi Wernher von Braun Arthur Rudolph space race rocketry V-2 immigration policy State Department Justice Department intelligence
177	Reducing turbulence- and transition-driven uncertainty in aerothermodynamic heating predictions for blunt-bodied reentry vehicles Ulerich, Rhys David 24 October 2014 (has links) Turbulent boundary layers approximating those found on the NASA Orion Multi-Purpose Crew Vehicle (MPCV) thermal protection system during atmospheric reentry from the International Space Station have been studied by direct numerical simulation, with the ultimate goal of reducing aerothermodynamic heating prediction uncertainty. Simulations were performed using a new, well-verified, openly available Fourier/B-spline pseudospectral code called Suzerain equipped with a ``slow growth'' spatiotemporal homogenization approximation recently developed by Topalian et al. A first study aimed to reduce turbulence-driven heating prediction uncertainty by providing high-quality data suitable for calibrating Reynolds-averaged Navier--Stokes turbulence models to address the atypical boundary layer characteristics found in such reentry problems. The two data sets generated were Ma[approximate symbol] 0.9 and 1.15 homogenized boundary layers possessing Re[subscript theta, approximate symbol] 382 and 531, respectively. Edge-to-wall temperature ratios, T[subscript e]/T[subscript w], were close to 4.15 and wall blowing velocities, v[subscript w, superscript plus symbol]= v[subscript w]/u[subscript tau], were about 8 x 10-3 . The favorable pressure gradients had Pohlhausen parameters between 25 and 42. Skin frictions coefficients around 6 x10-3 and Nusselt numbers under 22 were observed. Near-wall vorticity fluctuations show qualitatively different profiles than observed by Spalart (J. Fluid Mech. 187 (1988)) or Guarini et al. (J. Fluid Mech. 414 (2000)). Small or negative displacement effects are evident. Uncertainty estimates and Favre-averaged equation budgets are provided. A second study aimed to reduce transition-driven uncertainty by determining where on the thermal protection system surface the boundary layer could sustain turbulence. Local boundary layer conditions were extracted from a laminar flow solution over the MPCV which included the bow shock, aerothermochemistry, heat shield surface curvature, and ablation. That information, as a function of leeward distance from the stagnation point, was approximated by Re[subscript theta], Ma[subscript e], [mathematical equation], v[subscript w, superscript plus sign], and T[subscript e]/T[subscript w] along with perfect gas assumptions. Homogenized turbulent boundary layers were initialized at those local conditions and evolved until either stationarity, implying the conditions could sustain turbulence, or relaminarization, implying the conditions could not. Fully turbulent fields relaminarized subject to conditions 4.134 m and 3.199 m leeward of the stagnation point. However, different initial conditions produced long-lived fluctuations at leeward position 2.299 m. Locations more than 1.389 m leeward of the stagnation point are predicted to sustain turbulence in this scenario. / text Atmospheric reentry B-spline collocation Channel flow Cold wall Direct numerical simulation Energy perturbation method Favorable pressure gradient Flat plate Homogenized boundary layer Inviscid base flow Isothermal wall Low Reynolds number Manufactured solution NASA Orion Negative displacement thickness Predictive computation Pseudospectral method Radial nozzle Reducing uncertainty Reentry vehicle Relaminarization Sampling uncertainty Simulation framework Slow growth formulation Software verification Transition modeling Turbulence budgets Turbulent boundary layer Wall blowing Wall transpiration
178	Secondary World: The Limits of Ludonarrative Dannelly, David 01 January 2014 (has links) Secondary World: The Limits of Ludonarrative is a series of short narrative animations that are a theoretical treatise on the limitations of western storytelling in video games. The series covers specific topics relating to film theory, game design and art theory: specifically those associated with Gilles Deleuze, Jean Baudrillard, Jay Bolter, Richard Grusin and Andy Clark. The use of imagery, editing and presentation is intended to physically represent an extension of myself and my thinking process and which are united through the common thread of my personal feelings, thoughts and experiences in the digital age. Ludonarrative ludonarrative dissonance secondary world virtuality actual virtual hyperreality the real game design gilles deleuze simulation storytelling video game narrative ludology mind extension hypothesis virtual reality immediacy transparent immediacy jay bolter tolkien film theory art theory game studies andy clark appropriation associative thought animation thesis video art 2-d animation video games thinking process video installation video game art sign signifier signified the matrix nasa the last of us lucas pope papers please the stanley parable yahtzee croshaw zero punctuation persistence of vision immersion Film and Media Studies Game Design
179	The Biowall Field Test Analysis and Optimization Jacob J. Torres (5930906) 14 May 2019 (has links) <div> <p>A residential botanical air filtration system (Biowall) to investigate the potential for using phytoremediation to remove contaminants from indoor air was developed. A full scale and functioning prototype was installed in a residence located in West Lafayette, Indiana. The prototype was integrated into the central Heating, Ventilating, and Air Conditioning (HVAC) system of the home. This research evaluated the Biowall operation to further its potential as an energy efficient and sustainable residential air filtration system.<br></p> <p> </p> <p>The main research effort began after the Biowall was installed in the residence. A field evaluation, which involved a series of measurements and data analysis, was conducted to identify treatments to improve Biowall performance. The study was conducted for approximately one year (Spring 2017-Spring 2018). Based on the initial data set, prioritization of systems in need of improvement was identified and changes were imposed. Following a post-treatment testing period, a comparison between the initial and final performances was completed with conclusions based on this comparison. </p> <p> </p> <p>The engineering and analysis reported in this document focus on the air flow path through the Biowall, plant growth, and the irrigation system. The conclusions provide an extensive evaluation of the design, operation, and function of the Biowall subsystems under review.</p> </div> <br> Botany CAD/CAM Systems Metals and Alloy Materials Engineering not elsewhere classified Simulation and Modelling Computational Logic and Formal Languages Engineering Design Methods Engineering Systems Design Additive Manufacturing Botanical air filtration Building Automated System BAS Biowall phytoremediation. Sick Building Syndrome Controlled Environments NCERA-101 Six Sigma whirlpool ReNEWW Home plant growth experiment irrigation system Air Flow Distribution Characteristics Air Flow growth media experiments Plant Growth in Controlled Environments NASA Residential Air Filtration HVAC Automated Logic
180	Implementation and Analysis of Co-Located Virtual Reality for Scientific Data Visualization Jordan M McGraw (8803076) 07 May 2020 (has links) <div>Advancements in virtual reality (VR) technologies have led to overwhelming critique and acclaim in recent years. Academic researchers have already begun to take advantage of these immersive technologies across all manner of settings. Using immersive technologies, educators are able to more easily interpret complex information with students and colleagues. Despite the advantages these technologies bring, some drawbacks still remain. One particular drawback is the difficulty of engaging in immersive environments with others in a shared physical space (i.e., with a shared virtual environment). A common strategy for improving collaborative data exploration has been to use technological substitutions to make distant users feel they are collaborating in the same space. This research, however, is focused on how virtual reality can be used to build upon real-world interactions which take place in the same physical space (i.e., collaborative, co-located, multi-user virtual reality).</div><div><br></div><div>In this study we address two primary dimensions of collaborative data visualization and analysis as follows: [1] we detail the implementation of a novel co-located VR hardware and software system, [2] we conduct a formal user experience study of the novel system using the NASA Task Load Index (Hart, 1986) and introduce the Modified User Experience Inventory, a new user study inventory based upon the Unified User Experience Inventory, (Tcha-Tokey, Christmann, Loup-Escande, Richir, 2016) to empirically observe the dependent measures of Workload, Presence, Engagement, Consequence, and Immersion. A total of 77 participants volunteered to join a demonstration of this technology at Purdue University. In groups ranging from two to four, participants shared a co-located virtual environment built to visualize point cloud measurements of exploded supernovae. This study is not experimental but observational. We found there to be moderately high levels of user experience and moderate levels of workload demand in our results. We describe the implementation of the software platform and present user reactions to the technology that was created. These are described in detail within this manuscript.</div> Software Engineering Computer Software Computer Graphics Simulation and Modelling Virtual Reality and Related Simulation Mobile Technologies Networking and Communications Computer-Human Interaction Collaborative Virtual Reality Virtual Reality Collaborative Virtual Reality Networking Networked VR Mulitplayer Multiplayer VR Data Visualization Data Exploration Head Mounted Display Cyberspace Augmented Reality Emerging Technologies Consumer Devices Virtual Environment Virtual Aesthetics Collaborative VR Simulation Training Simulation and Training Colocated Colocated Virtual Environment Immersive Media Immersive Technology Collaborative Tools Educational Virtual Environment Point Cloud Representations Isosurface Representations Mesh Smoothng Supernova Supernovae Supernova Remnant Modeling Astronomy and Astrophysics Cassiopeia N132D E0102 Crab Nebula CAVE CAVE Theater Mobile VR Virtual Classrooms STEM Workload Workload Assessment Tool Presence Engagement Immersion Experience Consequence Simulator sickness Simulator Sickness Questionnaire NASA TLX NASA Task Load Index Unified User Experience Quesionnaire Modified User Experience Questionnaire Oculus Oculus Go Oculus Quest Novel Solutions Optitrack Motive Motion Capture Mocap User Experience Unity3D Game Engine Lidgren Room Scale VR Hall Scale VR Co-location Colocation Virtual Training Collaborative Virtual Environments Shared Virtual Environments Collaboration Whiteboard Mobile Virtual Reality VR HMD LAN UX CSCL UXQ TLX AR VE CVE 3D UI EVE

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