Дисертації з теми "Space and Solar Physics"
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Khotyaintsev, Mykola. "Radar Probing of the Sun." Doctoral thesis, Uppsala University, Department of Astronomy and Space Physics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7192.
Повний текст джерелаThis thesis is dedicated to the theory of solar radar experiments. The Sun exhibits a variety of interesting and complicated physical phenomena, examined mainly through analysis of its radiation. Active solar probing by radar provides an alternative possibility to study the Sun. This concept was tested originally in the 1960's by solar radar experiments at El Campo, Texas, but due to an insufficient level of technology at that time the experimental results were of a poor quality and thus difficult to interpret. Recently, the space weather program has stimulated interest in this topic. New experimental proposals require further development of the theory of solar radar experiments to meet the current knowledge about the Sun and the modern level of technology.
Three important elements of solar radar experiments are addressed in this thesis: i) generation of wave turbulence and radiation in the solar corona, ii) propagation of the radar signal to the reflection point, and iii) reflection (scattering) of the incident radar signal from the Sun.
It is believed that the radio emission of solar type II and III bursts occurs due to conversion of Langmuir waves, generated by electron beams, into electromagnetic radiation (plasma emission mechanism). The radar signal propagating through the emission source region can get scattered by the Langmuir turbulence and finally deliver the observer insights of the physics of this turbulence. Such process of scattering is considered in this thesis in the weak turbulence limit by means of the wave-kinetic theory. Scattering frequency shifts, scattering cross-sections, efficiency of scattering (the coefficient of absorption due to scattering), optical depths, and the spectra of the scattered signal are estimated.
Type II solar radio bursts are known to be associated with the electron beams accelerated by interplanetary shocks. From their dynamic spectra the properties of the shocks and regions in the vicinity of the shock are usually inferred by assuming a plasma emission mechanism. In situ observations of the source region of type II burst, presented in this thesis, suggest that an additional emission mechanism may be present. This mechanism is related to energetic particles crossing the shock front, known in electrodynamics as transition radiation.
Plasma density fluctuations are known to scatter radio waves and thus broadening their angular dispersion. In the thesis this process is studied in the solar wind and terrestrial electron and ion foreshocks on the basis of in situ observations of density fluctuations. It is shown that the angular broadening of the radar signal is negligible in this regions.
The results of this thesis can be applied for the preparation of future solar radar experiments and interpretation of experimental data.
Moore, Christopher Samuel. "Atomic Layer Deposition Re ective Coatings for future Astronomical Space Telescopes and the Solar Corona viewed through the MinXSS (Miniature X-ray Solar Spectrometer) CubeSats." Thesis, University of Colorado at Boulder, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10680697.
Повний текст джерелаAdvances in technology and instrumentation open new windows for observing astrophysical objects. The first half of my dissertation involves the development of atomic layer deposition (ALD) coatings to create high reflectivity UV mirrors for future satellite astronomical telescopes. Aluminum (Al) has intrinsic reflectance greater than 80% from 90 ? 2,000 nm, but develops a native aluminum oxide (Al2O3) layer upon exposure to air that readily absorbs light below 250 nm. Thus, Al based UV mirrors must be protected by a transmissive overcoat. Traditionally, metal-fluoride overcoats such as MgF2 and LiF are used to mitigate oxidation but with caveats. We utilize a new metal fluoride (AlF3) to protect Al mirrors deposited by ALD. ALD allows for precise thickness control, conformal and near stoichiometric thin films. We prove that depositing ultra-thin (~3 nm) ALD ALF3 to protect Al mirrors after removing the native oxide layer via atomic layer etching (ALE) enhances the reflectance near 90 nm from ~5% to ~30%. X-ray detector technology with high readout rates are necessary for the relatively bright Sun, particularly during large flares. The hot plasma in the solar corona generates X-rays, which yield information on the physical conditions of the plasma. The second half of my dissertation includes detector testing, characterization and solar science with the Miniature X-ray Solar Spectrometer (MinXSS) CubeSats. The MinXSS CubeSats employ Silicon Drift Diode (SDD) detectors called X123, which generate full sun spectrally resolved (~0.15 FWHM at 5.9 keV) measurements of the sparsely measured, 0.5 ? 12 keV range. The absolute radiometric calibration of the MinXSS instrument suite was performed at the National Institute for Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF) and spectral resolution determined from radioactive sources. I used MinXSS along with data from the Geostationary Operational Environmental Satellites (GOES), Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), Hinode X-ray Telescope (XRT), Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) and Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) to study the solar corona. This resulted in new insights on the coronal temperature distribution and elemental abundance variations for quiescence, active regions and during solar flares.
Seki, Daikichi. "Space Weather Prediction Using Ground-Based Observations." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263804.
Повний текст джерела京都大学
新制・課程博士
博士(総合学術)
甲第23343号
総総博第16号
京都大学大学院総合生存学館総合生存学専攻
(主査)教授 山敷 庸亮, 教授 寶 馨, 准教授 浅井 歩
学位規則第4条第1項該当
Doctor of Philosophy
Kyoto University
DFAM
Retinò, Alessandro. "Magnetic Reconnection in Space Plasmas : Cluster Spacecraft Observations." Doctoral thesis, Uppsala University, Department of Astronomy and Space Physics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7891.
Повний текст джерелаMagnetic reconnection is a universal process occurring at boundaries between magnetized plasmas, where changes in the topology of the magnetic field lead to the transport of charged particles across the boundaries and to the conversion of electromagnetic energy into kinetic and thermal energy of the particles. Reconnection occurs in laboratory plasmas, in solar system plasmas and it is considered to play a key role in many other space environments such as magnetized stars and accretion disks around stars and planets under formation. Magnetic reconnection is a multi-scale plasma process where the small spatial and temporal scales are strongly coupled to the large scales. Reconnection is initiated rapidly in small regions by microphysical processes but it affects very large volumes of space for long times. The best laboratory to experimentally study magnetic reconnection at different scales is the near-Earth space, the so-called Geospace, where Cluster spacecraft in situ measurements are available. The European Space Agency Cluster mission is composed of four-spacecraft flying in a formation and this allows, for the first time, simultaneous four-point measurements at different scales, thanks to the changeable spacecraft separation. In this thesis Cluster observations of magnetic reconnection in Geospace are presented both at large and at small scales.
At large temporal (a few hours) and spatial (several thousands km) scales, both fluid and kinetic evidence of reconnection is provided. The evidence consist of ions accelerated and transmitted across the Earth’s magnetopause. The observations show that component reconnection occurs at the magnetopause and that reconnection is continuous in time.
The microphysics of reconnection is investigated at smaller temporal (a few ion gyroperiods) and spatial (a few ion gyroradii) scales. Two regions are important for the microphysics: the X-region, around the X-line, where reconnection is initiated and the separatrix region, away from the X-line, where most of the energy conversion occurs. Observations of a separatrix region at the magnetopause are shown and the microphysics is described in detail. The separatrix region is shown to be highly structured and dynamic even away from the X-line.
Finally the discovery of magnetic reconnection in turbulent plasma is presented by showing, for the first time, in situ evidence of reconnection in a thin current sheet found in the turbulent plasma downstream of the quasi-parallel Earth’s bow shock. It is shown that turbulent reconnection is fast and that electromagnetic energy is converted into heating and acceleration of particles in turbulent plasma. It is also shown that reconnecting current sheets are abundant in turbulent plasma and that reconnection can be an efficient energy dissipation mechanism.
Rosenqvist, Lisa. "Energy Transfer and Conversion in the Magnetosphere-Ionosphere System." Doctoral thesis, Uppsala University, Department of Astronomy and Space Physics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8716.
Повний текст джерелаMagnetized planets, such as Earth, are strongly influenced by the solar wind. The Sun is very dynamic, releasing varying amounts of energy, resulting in a fluctuating energy and momentum exchange between the solar wind and planetary magnetospheres. The efficiency of this coupling is thought to be controlled by magnetic reconnection occurring at the boundary between solar wind and planetary magnetic fields. One of the main tasks in space physics research is to increase the understanding of this coupling between the Sun and other solar system bodies. Perhaps the most important aspect regards the transfer of energy from the solar wind to the terrestrial magnetosphere as this is the main source for driving plasma processes in the magnetosphere-ionosphere system. This may also have a direct practical influence on our life here on Earth as it is responsible for Space Weather effects. In this thesis I investigate both the global scale of the varying solar-terrestrial coupling and local phenomena in more detail. I use mainly the European Space Agency Cluster mission which provide unprecedented three-dimensional observations via its formation of four identical spacecraft. The Cluster data are complimented with observations from a broad range of instruments both onboard spacecraft and from groundbased magnetometers and radars.
A period of very strong solar driving in late October 2003 is investigated. We show that some of the strongest substorms in the history of magnetic recordings were triggered by pressure pulses impacting a quasi-stable magnetosphere. We make for the first time direct estimates of the local energy flow into the magnetotail using Cluster measurements. Observational estimates suggest a good energy balance between the magnetosphere-ionosphere system while empirical proxies seem to suffer from over/under estimations during such extreme conditions.
Another period of extreme interplanetary conditions give rise to accelerated flows along the magnetopause which could account for an enhanced energy coupling between the solar wind and the magnetosphere. We discuss whether such conditions could explain the simultaneous observation of a large auroral spiral across the polar cap.
Contrary to extreme conditions the energy conversion across the dayside magnetopause has been estimated during an extended period of steady interplanetary conditions. A new method to determine the rate at which reconnection occurs is described that utilizes the magnitude of the local energy conversion from Cluster. The observations show a varying reconnection rate which support the previous interpretation that reconnection is continuous but its rate is modulated.
Finally, we compare local energy estimates from Cluster with a global magnetohydrodynamic simulation. The results show that the observations are reliably reproduced by the model and may be used to validate and scale global magnetohydrodynamic models.
Pacheco, Mateo Daniel. "Analysis and modelling of the solar energetic particle radiation environment in the inner heliosphere in preparation for Solar Orbiter." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/667033.
Повний текст джерелаEl Sol és la principal font de partícules que podem trobar al medi interplanetari del sistema solar, i els esdeveniments solars de partícules energètiques són la principal font de radiació dins de l'heliosfera. L'estudi i predicció d'aquest tipus d'esdeveniments i les seves causes i conseqüències ha esdevingut una àrea d'especial interès per la seva importància enfront dels perills que suposa aquesta radiació per a les telecomunicacions i la salut durant missions espacials tripulades. En aquesta tesi exposem el treball que hem desenvolupat en aquest camp, dividit en 3 àmbits diferents: i) estudi observacional d'esdeveniments de partícules fent servir dades observacionals de missions espacials com STEREO i Helios, i eines com SEPEM; ii) desenvolupament d'eines i modalització d'instruments de partícules per fer-los servir conjuntament amb els models preexistents per la simulació d'esdeveniments; iii) simulació d'esdeveniments de partícules mitjançant models de transport, tant adaptant eines prèviament desenvolupades pel nostre grup, com SEPInversion, com nou programari capaç de realitzar inversions totals, es a dir, tenint en compte la resposta angular i energètica dels instruments. Les eines desenvolupades ens han permès estudiar les condicions de radiació a l'heliosfera interior com no s'havia fet fins ara. Els resultats obtinguts així com aquestes eines seran molt útils per a l'estudi i interpretació de les dades científiques provinents de les futures missions espacials com Parker Solar Probe o Solar Orbiter. A més a més, les eines desenvolupades ens permetran fer un ús efectiu d'aquestes dades tan aviat com estiguin disponibles.
Cimaroli, Alexander J. "Development of Deposition and Characterization Systems for Thin Film Solar Cells." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1481295690696407.
Повний текст джерелаPerna, Davide. "Physical properties of asteroid targets of the Rosetta space mission, and of minor bodies of the outer Solar System." Observatoire de Paris (1667-....), 2010. https://hal.science/tel-02094984.
Повний текст джерелаThe minor bodies of the Solar System are the remnants of the primordial planetesimal population, their investigation can hence improve our knowledge about the environment conditions in the solar nebula, and the thermal and physical processes that took place in the early phases of the Solar System. During my Phd, I focused on the physical characterization of the asteroids (2867) Steins and (21) Lutetia, targets of the Esa-Rosetta space mission, and of the minor bodies of the outer Solar System (Centaurs et Trans-Neptunian Objects, TNOS). I performed visible photometric and spectroscopic observations of Steins and Lutetia using the Telescopio Nazionale Galileo, from the reduction, and the analysis, and the interpretation of the obtained data, I improved the physical knowledge of both the objects prior to the Rosetta fly-by. In this thesis I also present the results I obtained as part of large programme performed at the European Southern Observatory on Centaurs and the Trans-Neptunian Objects. I contributed to the interpretation of the obtained spectra using radiative transfer models. On the basis of the obtained photometric colors, I derived the taxonomic classification of the observed objects, and I performed a statistical analysis using also the whole available literature looking for correlations between taxonomy and dynamics. From the interpretation of the light curves I gathered information about the rotation, shape and density of the objects under analysis, and I investigated the density statistics of the small bodies of the outer Solar System combining these new results with literature data
Jaklovsky, Simon. "Drag based forecast for CME arrival." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415153.
Повний текст джерелаHåkansson, Marcus. "Back-tracing of water ions at comet 67P/Churyumov–Gerasimenko." Thesis, Luleå tekniska universitet, Rymdteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67050.
Повний текст джерелаGrigoriev, Alexander. "The Neutral Particle Detector on the Mars and Venus Express missions." Doctoral thesis, Kiruna : Swedish Institute of Space Physics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1339.
Повний текст джерелаGadisa, Abay. "Studies of Charge Transport and Energy Level in Solar Cells Based on Polymer/Fullerene Bulk Heterojunction." Doctoral thesis, Linköping : LInköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8047.
Повний текст джерелаRamstad, Robin. "Ion escape from Mars : measurements in the present to understand the past." Doctoral thesis, Umeå universitet, Institutionen för fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-141892.
Повний текст джерелаÅgren, Karin. "On the Formation and Structure of the Ionosphere of Titan." Doctoral thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172148.
Повний текст джерелаArvelius, Sachiko. "Energization and Acceleration of Dayside Polar Outflowing Oxygen." Doctoral thesis, Kiruna : Swedish Institute of Space Physics, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-647.
Повний текст джерелаBrinkfeldt, Klas. "Instrumentation for energetic Neutral atom measurements at Mars, Venus and The Earth." Doctoral thesis, Kiruna : Swedish Institute of Space Physics, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-657.
Повний текст джерелаGazda, Daniel Bryan. "Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies." Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835309-K3fMzj/webviewable/.
Повний текст джерелаTrella, Fredrik, and Nils Paakkonen. "Development of a Cost-Effective, Reliable and Versatile Monitoring System for Solar Power Installations in Developing Countries : A Minor Field Study as a Master Thesis of the Master Programme in Engineering Physics, Electrical Engineering." Thesis, Uppsala universitet, Fasta tillståndets elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302815.
Повний текст джерелаBusch, Brian C. "Space-based solar power system architecture." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/27802.
Повний текст джерелаOza, Shefali Bharat 1982. "Forging the inner space- outer space connection." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32756.
Повний текст джерелаIncludes bibliographical references (p. 59).
In this thesis, I discuss the Brans-Dicke theory of gravitation, the Higgs mechanism, and the relevance of these two theories to the bridging of cosmology and particle physics. Although the former theory is in the field of cosmology while the latter is in particle physics, their similarities are impressive. Both attempt to understand the origins of mass. Even more striking is the mathematics involved in each of these theories. The Brans-Dicke theory and the Higgs mechanism both introduce a new scalar field that is coupled to matter in the universe. Although these theories were formulated around the same time in the early 1960s, are so similar in motivation and method, and became quite popular in their own respective fields, they remained relatively unknown outside of their field for quite some time. In this thesis, I have summarized both the Brans-Dicke theory and the Higgs mechanism. Then, I have analyzed the number of articles citing the Brans-Dicke and Higgs papers to understand when particle physics and cosmology first began integrating. To extend this further, I have looked at how many articles in 1961, 1971, 1981, and 1991 can be categorized as both particle physics and cosmology. In conclusion, we see that the two fields were slow to build common ground, although this has improved since the 1980s. By the 1990s, collaboration between particle physics and cosmology had greatly increased, most likely because of attempts to unify gravity with the other three forces.
by Shefali Bharat Oza.
S.B.
Lo, S. N. G. "Passive solar space and water heating systems." Thesis, Cranfield University, 1990. http://hdl.handle.net/1826/3935.
Повний текст джерелаTress, Wolfgang. "Device Physics of Organic Solar Cells." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-89501.
Повний текст джерелаDiese Dissertation beschäftigt sich mit der Physik organischer Solarzellen. Die organische Photovoltaik ist ein Forschungsgebiet, dem in den letzten zehn Jahren enorme Aufmerksamkeit zu Teil wurde. Der Grund liegt darin, dass diese neuartigen Solarzellen, deren aktueller Rekordwirkungsgrad bei 10 Prozent liegt, ein Potential für eine kostengünstige Produktion auf flexiblem (Polymer)substrat aufweisen und aufgrund ihrer Vielfältigkeit neue Anwendungsbereiche für die Photovoltaik erschließen. Organische Solarzellen bestehen aus ultradünnen (einige 10 nm) Schichten aus Kohlenwasserstoffverbindungen. Damit der photovoltaische Effekt genutzt werden kann, müssen die durch Licht angeregten Molekülzustände zu freien Ladungsträgern führen, wobei positive und negative Ladung an unterschiedlichen Kontakten extrahiert werden. Für eine effektive Trennung dieser stark gebundenden lokalisierten angeregten Zustände (Exzitonen) ist eine Grenzfläche zwischen Molekülen mit unterschiedlichen Energieniveaus der Grenzorbitale erforderlich, sodass ein Elektron auf einem Akzeptor- und eine positive Ladung auf einem Donatormolekül entstehen. Diese Grenzschicht kann als planarer Heteroübergang durch zwei getrennte Schichten oder als Volumen-Heteroübergang in einer Mischschicht realisiert werden. Die Absorberschichten werden durch Elektroden kontaktiert, wobei es für effiziente Solarzellen erforderlich ist, dass diese einen ohmschen Kontakt ausbilden, da ansonsten Verluste zu erwarten sind. Diese Arbeit behandelt im Besonderen die elektrischen Prozesse einer organischen Solarzelle. Dafür wird ein eindimensionales Drift-Diffusionsmodell entwickelt, das den Transport von Exzitonen, deren Trennung an einer Grenzfläche und die Ladungsträgerdynamik beschreibt. Abgesehen von den Exzitonen gilt als weitere Besonderheit einer organischen Solarzelle, dass sie aus amorphen, intrinsischen und sehr schlecht leitfähigen Absorberschichten besteht. Elektrische Effekte sind an der Strom-Spannungskennlinie (I-U ) sichtbar, die in dieser Arbeit als Hauptvergleichspunkt zwischen experimentellen Solarzellendaten und den Simulationsergebnissen dient. Durch einen weitgehend qualitativen Vergleich können dominierende Prozesse bestimmt und mikroskopische Erklärungen gefunden werden. Ein wichtiger Punkt ist der schon erwähnte Kontakt zwischen Absorberschicht und Elektrode. Dort auftretende Energiebarrieren führen zu einem Einbruch im Solarzellenwirkungsgrad, der sich durch eine Verringerung der Leerlaufspanung und/oder S-förmigen Kennlinien (S-Knick) bemerkbar macht. Anhand einer systematischen Studie der Grenzfläche Lochleiter/Donator wird gezeigt, dass Energiebarrieren sowohl für die Ladungsträgerextraktion als auch für die -injektion zu S-Knicken führen können. Insbesondere die Tatsache, dass Injektionsbarrieren sich auch negativ auf den Photostrom auswirken, wird anhand von simulierten Ladungsträger- und elektrischen Feldprofilen erklärt. Das Aufstauen von Ladungsträgern an Extraktionsbarrieren wird durch Messungen transienter Photoströme bestätigt. Da S-Knicke in organischen Solarzellen im Allgemeinen häufig beobachtet werden, werden weitere Methoden vorgeschlagen, die die Identifikation der Ursachen ermöglichen. Dazu zählen I-U Messungen in Abhängigkeit von Temperatur und Schichtdicken. Als eine weitere Ursache von S-Knicken werden unausgeglichene Ladungsträgerbeweglichkeiten in einer Solarzelle mit flachem Übergang identifiziert und von den Barrierefällen unterschieden. Weiterer Forschungsgegenstand dieser Arbeit sind Mischschichtsolarzellen aus dem Donator-Farbstoff Zink-Phthalozyanin ZnPc und dem Akzeptor Fulleren C60. Dort wird beobachtet, dass die Leerlaufspannung vom Mischverhältnis abhängt. Ein Vergleich von Experiment und Simulation zeigt, dass sich das Ionisationspotenzial von ZnPc und dadurch die effektive Energielücke des Mischsystems ändern. Zusätzlich zu homogenen Mischschichten werden Solarzellen untersucht, die einen Gradienten im Mischungsverhältnis aufweisen. Die Vermutung liegt nahe, dass ein hoher Donatorgehalt am Löcherkontakt und ein hoher Akzeptorgehalt nahe des Elektronenkontakts die Ladungsträgerextraktion begünstigen. Dieser Effekt ist in dem hier untersuchten System allerdings vergleichsweise irrelevant gegenüber der Tatsache, dass der Gradient das Abfließen bzw. die Rekombination von Ladungsträgern am “falschen” Kontakt reduziert und somit die Leerlaufspannung erhöht. Der wichtigste intrinsische Verlustmechanismus einer Solarzelle ist die Rekombination von Ladungsträgern. Diese wird im letzten Teil der Arbeit anhand der ZnPc:C60 Solarzelle behandelt. Messungen der Leerlaufspannung in Abhängigkeit von der Beleuchtungsintensität zeigen, dass sich der dominierende Rekombinationsprozess mit zunehmender Intensität von Störstellenrekombination zu direkter Rekombination von freien Ladungsträgern verschiebt. Eine gezielte Variation des Absorptionsprofils in der Absorberschicht zeigt, dass die Ladungsträgerextraktionswahrscheinlickeit vom Ort der Ladungsträgergeneration abhängt. Dieser Effekt wird hervorgerufen durch unausgeglichene Elektronen- und Löcherbeweglichkeiten und äußert sich im Füllfaktor. Weitere Simulationsergebnisse bezüglich des Einflusses von Ladungsträgerbeweglichkeiten und verschiedener Rekombinationsmechanismen auf die I-U Kennlinie und die experimentelle Identifikation eines Photoshunts, der den Photostrom in Rückwärtsrichtung unter Beleuchtung dominiert, runden die Arbeit ab
Perez-Davis, Marla Esther. "Heat receivers for solar dynamic space power systems." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055525095.
Повний текст джерелаFeteha, Mohamed Yousef Mohamed. "Heterojunction AlGaAs-GaAs solar cells for space applications." Thesis, University of Central Lancashire, 1995. http://clok.uclan.ac.uk/18836/.
Повний текст джерелаGiersch, Owen David. "Solar Variability and Automated Analysis for Space Weather." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/48641.
Повний текст джерелаGibbard, Seran Gwen 1967. "Lightning in the solar system." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/290640.
Повний текст джерелаDowker, Fay H. "Space-time wormholes." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359554.
Повний текст джерелаSeeluangsawat, Paisa 1980. "Magnetic holes in the solar wind." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8536.
Повний текст джерелаIncludes bibliographical references (p. 41).
We attempt to locate magnetic holes from several years of data collected from WIND and ACE spacecraft and use them to study some statistical properties of the magnetic holes.
by Paisa Seeluangsawat.
S.B.
Kargel, Jeffrey Stuart. "Cryomagmatism in the outer solar system." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185177.
Повний текст джерелаPotscavage, William J. Jr. "Physics and engineering of organic solar cells." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39634.
Повний текст джерелаLewis, Jason Erik. "Device Physics of Solution Processable Solar Cells." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3205.
Повний текст джерелаBhattacharya, Yajnavalkya. "Analysis of a solar occultation experiment from the space shuttle Columbia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0030/MQ27334.pdf.
Повний текст джерелаWoolsey, Lauren. "Magnetic Influences on the Solar Wind." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493537.
Повний текст джерелаAstronomy
Hudec, Chris L. "Construction of Gallium Arsenide Solar Concentrator for space use." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22989.
Повний текст джерелаFernandez, Randyll R. M. "A novel Photovoltaic Power Converter for military and space applications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FFernandez.pdf.
Повний текст джерелаWoodcock, Jonathan Peter. "Simulations of space plasma instabilities." Thesis, Queen Mary, University of London, 1997. http://qmro.qmul.ac.uk/xmlui/handle/123456789/131.
Повний текст джерелаRobbins, Glenn. "New Physics at Colliders and in Space." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1149/document.
Повний текст джерелаThe quest for new physics is a challenging task which involves, on the one hand, the search for dark matter particles from space, and on the other hand, the search at colliders for particles predicted by theories beyond the Standard Model, such as supersymmetry. With the experimental constraints on new particles getting stronger, it becomes crucial to combine the limits from both sectors in order to guide future searches. To this end, it is essential to estimate and take into account correctly the astrophysical, nuclear and cosmological uncertainties, which are most often ignored. The first part of this thesis is dedicated to the study of such uncertainties and to their impact on the constraints applied on supersymmetry. Moreover, we investigate the interplay between the constraints from colliders and dark matter searches in some detail. The second part concerns the development and the implementation in the public code SuperIso Relic of numerical tools for the calculation of direct and indirect dark matter detection constraints which were designed specifically to take correctly into account astrophysical and nuclear uncertainties. Finally, in the third part of this work, we consider the cosmological implications of a hypothetical discovery of new particles at colliders. We show that it would be possible to test the assumptions of the standard cosmological model and to obtain information on the properties of the primordial Universe at an epoch which is beyond observational reach
Do, Changwoo 1978. "Reciprocal space phase gradient neutron imaging." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/16932.
Повний текст джерелаIncludes bibliographical references (leaves 77-78).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Perfect crystal real space imaging has limitations in its resolution imposed by position sensitive detectors. The disadvantage, its limited resolution, of a position-sensitive detector can be overcome by replacing the conventional detector with an area detector and moving to reciprocal space. Reciprocal space imaging is proposed in this thesis with the state-of-the-art neutron interferometry at National Institute of Standard and Technology. An aluminum wedge produces various phase gradients and a specially designed sample is introduced as a test subject. Superposition of the waves from the sample beam path and the gradient wedge beam path creates an interferogram that suggests an inhomogeneous phase distribution. The result shows the existence of spatially encoded phase gradients, even though imaging was unsuccessful. A next generation design of reciprocal space imaging is proposed in the conclusion.
by Changwoo Do.
S.M.
Mattingly, Sean Walter. "Velocity Space Degrees of Freedom of Plasma Fluctuations." Thesis, The University of Iowa, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10263114.
Повний текст джерелаThis thesis demonstrates a measurement of a plasma fluctuation velocity-space cross-correlation matrix using laser induced fluorescence. The plasma fluctuation eigenmode structure on the ion velocity distribution function can be empirically determined through singular value decomposition from this measurement. This decomposition also gives the relative strengths of the modes as a function of frequency. Symmetry properties of the matrix quantify systematic error. The relation between the eigenmodes and plasma kinetic fluctuation modes is explored. A generalized wave admittance is calculated for these eigenmodes. Since the measurement is a localized technique, it may be applied to plasmas in which a single point measurement is possible, multipoint measurements may be difficult, and a velocity sensitive measurement technique is available.
Domert, Daniel. "Explorations of University Physics in Abstract Contexts : From de Sitter Space to Learning Space." Doctoral thesis, Uppsala universitet, Fysikundervisningen didaktik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7265.
Повний текст джерелаLysko, Meena Devi. "Measurement and Models of Solar Irradiance." Doctoral thesis, Norwegian University of Science and Technology, Department of Physics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-779.
Повний текст джерелаSolar radiation is the main driving force for the Earth’s weather and climate. It is also the prime source for renewable energy technologies.Solar energy technologies can satisfy the current energy demand and at the same time reduce anthropogenic greenhouse gas emissions. It follows from scientific and engineering research within the field that accurate terrestrial solar radiation data and derived models can improve the detection of longterm climate change, the validation of Earth radiation budget estimates, and the deployment of solar energy systems. But, accurate assessment of solar energy at the Earth’s surface is difficult due to spatial, temporal and angular variability. These variations emphasise the need for localised solar radiation measurements and models.
In light of the above, this work has aimed at improving the quality of radiation data at two specific locations; one in Trondheim, Norway and the other in Durban, South Africa. This has entailed the development of an automatic data logging system, and frequent radiometer calibrations with traceability to the World Radiometric Reference. In addition, a radiometer called the Direct-Diffuse Solar Radiometer has been developed for the mapping of sky radiance. Supplementary work has been done to re-affirm the need for quality ground-based data.
The work done is twofold, the first on the measurements of solar irradiance and the second on the implementation of solar radiation models. So, the presentation of the work is divided into two parts. Chapters 1 to 5 are included in Part A under the heading “Measurement of Solar Irradiance”. Chapters 6 is given in Part B, “Data Modelling”.
Chapter 1 describes the concept of solar irradiance, discusses the components of solar radiation and introduces the radiometers in common use for the measurements of solar irradiance. Motivations for the development of the Direct-Diffuse Solar Radiometer are also included.
Chapter 2 describes the radiation mapping at the two sites, with particular emphasis on methods implemented for higher accuracy sampling, data reliability and continuity.
Regular radiometer calibration is necessary to ensure the data quality. Therefore the methodology for and results from calibration of the site radiometers are given in Chapter 3.
The acquired direct and global data for the sites are presented in Chapter 4. Diurnal 1-minute variations are discussed along with estimates of monthly and annual trends, with particular emphasis on atmospheric transmittance and the clearness index.
The last chapter in Part A, i.e. Chapter 5, presents the work done on the Direct-Diffuse Solar Radiometer (DDSR-1B). The instrument is designed for measuring sky irradiance as well as direct solar irradiance. The DDSR-1B is a prototype ground based instrument which is mounted on a remotely controlled solar tracker/sky positioner. The Chapter discusses the DDSR- 1B’s design, control, calibration and field tests in detail.
Chapter 6 in Part B considers 2 available software products that can generate estimates of direct normal solar irradiances for any ground location. This chapter also concludes the work for this thesis by reemphasising the need for localised solar radiation measurements and models.
Finally, Chapter 7 collects the major conclusions given through the course of this text.
Jungbluth, Anna S. B. Massachusetts Institute of Technology. "Demonstrating visibly transparent solar cells and photodetectors." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111885.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 62-66).
The fabrication of inorganic semiconductor devices, such as silicon solar cells and photodetectors, is despite significant research still expensive and energy intensive. Especially for solar cells, high upfront costs are a limiting factor for large-scale fabrication and implementation. Organic semiconductors have attracted increasing attention over the last decade for their optoelectronic properties and potential applications in electronics and photonics. The ease of processing, light weight and low cost of organic semiconductors provides the opportunity for inexpensive, large-scale fabrication. In addition, the mechanical flexibility and bandgap tunability of organic materials enables the fabrication of flexible and semi-transparent organic solar cells and photodetectors that could be installed on any surface and integrated into windows and displays. This thesis demonstrates visibly transparent solar cells and photodetectors, fabricated using the organic materials tetraphenyldibenzoperiflanthene (DBP) and chloroaluminum phthalocyanine (CIAlPc). We fabricated our devices through spin-coating, thermal evaporation and sputtering and characterized the performance of our devices by measuring the current-voltage behavior, external quantum efficiency and visible transparency. Our devices demonstrate an average visible transparency of around 56%, power conversion efficiencies between 0.53% and 1.36% and specific detectivities on the order of 1011 to 1012 Jones. These values are comparable to results found in literature. The primary goal of this work is to highlight the potential of organic materials for transparent electronics and to provide a detailed overview of the fabrication and characterization techniques needed to advance research in this area.
by Anna Jungbluth.
S.B.
Ghamande, Maithili. "Optical Modeling of Organic Photovoltaic Solar Cells." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1320329919.
Повний текст джерелаLoughman, Robert Paul 1971. "A detailed numerical description of the solar aureole." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/291355.
Повний текст джерелаKabir, Saqib. "Designing of a solar panel deployment mechanism for small satellite." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33822.
Повний текст джерелаCyr, Kimberly Ellen 1964. "The distribution of water in the solar nebula: Implications for solar system formation." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288870.
Повний текст джерелаNoel, Nakita K. "Advances in hybrid solar cells : from dye-sensitised to perovskite solar cells." Thesis, University of Oxford, 2014. https://ora.ox.ac.uk/objects/uuid:e0f54943-546a-49cd-8fd9-5ff07ec7bf0a.
Повний текст джерелаAppleby, David Marcus. "Quantum mechanics on phase space." Thesis, Queen Mary, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267642.
Повний текст джерелаAwan, G. R. "Cadmium telluride for solar cells." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6852/.
Повний текст джерелаKumar, Praveen. "Kinematic bifurcations and deployment simulation of foldable space structures." Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/271901.
Повний текст джерела