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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.
231

Os diários de juventude de Liev Tolstói, tradução e questões sobre o gênero de diário / The youth diaries of Leo Tolstoy, translation and studies on the diary genre

Natalia Cristina Quintero Erasso 24 March 2011 (has links)
Liev Tolstói, autor russo do século XIX, reconhecido tanto pelos acadêmicos como pelo público geral como um dos maiores romancistas da história, ao longo de mais de sessenta anos escreveu um diário paralelamente a sua vasta obra artística. No conjunto de toda a produção escrita do autor, o diário constitui a sua obra mais volumosa, contudo, quase inexplorada em língua portuguesa. O presente trabalho propõe-se aproximar o leitor brasileiro dessa faceta menos conhecida de Tolstói por meio da tradução, direta do russo, dos primeiros sete anos do diário (1847 1854). Observa-se o que há de particular nesse texto de Tolstói, no âmbito do diário como gênero literário e, por fim, questiona-se a possibilidade de ler o diário de Tolstói como criação artística independente ou se deve ele ser tratado como um coadjuvante na interpretação das obras literárias do autor. / Leo Tolstoy, great Russian writer of the nineteenth century, recognized as one of the leading novelists in the history of the genre, both by scholars and the general public, spent over sixty years writing a diary. Throughout the vast production written by the author, this diary is his most voluminous work, yet still unexplored and almost unknown in Portuguese. This work presents a translation directly from Russian of the first seven years of the diary (1847 - 1854) and also makes a first reflection on the nature of the text which encompasses the characteristics of Tolstoy\'s diary related to the genre. Then it analyzes whether Tolstoys diary can be treated as an artistic creation or as supporting text in the interpretation of literary works of the author.
232

Caracteriza??o qu?mica e atividade inseticida dos ?leos essenciais de plantas arom?ticas procedentes do Brasil e de Cuba sobre o desenvolvimento p?s-embrion?rio de d?pteros muscoides.

PINTO, Zeneida Teixeira 10 February 2015 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-22T17:12:01Z No. of bitstreams: 1 2015 - Zeneida Teixeira Pinto.pdf: 2580042 bytes, checksum: 0224e4e1200e83ae2a5e09bfaf7ca97d (MD5) / Made available in DSpace on 2017-06-22T17:12:01Z (GMT). No. of bitstreams: 1 2015 - Zeneida Teixeira Pinto.pdf: 2580042 bytes, checksum: 0224e4e1200e83ae2a5e09bfaf7ca97d (MD5) Previous issue date: 2015-02-10 / CAPES / The muscoid flies have important public health because it acts as a mechanical vector of pathogens (bacteria, viruses, helminth eggs) and cause secondary myiasis in humans and animals. Chemical insecticides have been of great importance in the control of synanthropic flies, but have great persistence and a broad spectrum of action, causing a prolonged impact on the environment. An alternative way to this type of control are secondary metabolites of plants, which are considered the active principle of natural insecticides. This study was divided into two chapters that approached the the theme of natural control. The first chapter is related to the essential oil chemical composition of Cymbopogon citratus collected d in Brazil and Cuba, and evaluation of oil and its major component citral against the post-embryonic development of Musca domestica, Chrysomya putoria, C. megacephala and Lucilia cuprina. The chemical analysis of the essential oils allowed the identification of 13 and 12 chemical components, respectively, and in both the major components were the isomers Neral (35.21% ? Cuba) (36.37% - Brazil) and Geranial (53.2% - Brazil) (51.14% - Cuba) and, Myrcene (6.52%), in a smaller proportion, was only found in Cuban oil. The results show that there were no differences between the activity of Cuban oil and Brazilian. The post-embryonic period of L. cuprina, M. domestica and C. megacephala elongated with the treatment with both oils, but it shortened the larval and neolarva to adult periods for C. putoria. All groups presented morphological alterations. The results of the the test showed that C. megacephala was the most sensitive species killing 73% in larval stage and 77% in newly-hatched larvae to adult and less sensitive was C. putoria with 40% mortality in the larval stage and 57% in newly-hatched larvae to adult. Citral shortened post-embryonic development period (larval, pupal and newly hatched larvae to adult) of M. domestica, L. cuprina and C. megacephala but C. putoria was delayed. In the second chapter, the aim was to analyze the chemical composition and insecticidal effect of the essential oils extracted from leaves of Pinus caribaea Morelet collected in Brazil and Cuba and the terpene Caryophyllene, on the post- embryonic development of the species Musca domestica, Chrysomya megacephala, C. putoria e Lucilia cuprina. Twelve components were identified in the essential oil of P. cariabea collected in Brazil, and ? Phellandrene and Germacren D and (E) Caryophyllene were the major components, with relative areas of 39.57, 26.57 and 16.85% respectively. In comparison, 20 components were identified from the essential oil of the same species originated from Cuba with the major components, Germacrene D (48.25%), o ?-Phellandrene (12.10%) and Caryophyllene Oxide (12.41%). Caryophyllene was more toxic to M. domestica with an 87% of mortality for the newly hatched larvae to adult, the less affected species were L. cuprina and C. megacephala with 83% of mortality and for C. putoria the mortality was 63%. The post-embryonic development period was shortened in the species M. domestica, L. cuprina and C. megacephala and prolonged in C. putoria. The pupal weight was reduced in most species except in C. putoria that it had increased; there was no change in the sex ratio in the species in the study. / Os d?pteros muscoides apresentam import?ncia em sa?de p?blica, pois atua como vetor mec?nico de pat?genos (bact?rias, v?rus, ovos de helmintos), al?m de causar mi?ases secund?rias no homem e nos animais. Os inseticidas qu?micos t?m sido de grande import?ncia no controle de d?pteros sinantr?picos, mas apresentam grande persist?ncia e um amplo espectro de a??o, causando um impacto prolongado ao ambiente. Uma forma alternativa a este tipo de controle s?o os metab?litos secund?rios de plantas, que s?o considerados o princ?pio ativo dos inseticidas naturais. O presente estudo foi dividido em dois cap?tulos que abordam o tema do controle natural. O primeiro cap?tulo foi relativo a analise da composi??o qu?mica do ?leo essencial de Cymbopogon citratus coletado no Brasil e Cuba, e da avalia??o do ?leo e do seu componente majorit?rio citral sob o desenvolvimento p?s-embrion?rio de Musca domestica, Chrysomya putoria, C. megacephala e Lucilia cuprina. A an?lise da composi?ao qu?mica dos ?leos essenciais (Brasil/Cuba), por Cromatografia Gasosa acoplada ao espectr?metro de massa (GC-EM), permitiu a identifica?ao de 13 e 12 componentes principais, respectivamente; nove deles comuns aos dois. Em ambos os ?leos, os principais componentes foram os is?meros geranial e neral, que, juntos, formam o composto citral. Esse corresponde a um total de 97,92%/Brasil e 97,69%/Cuba dos compostos identificados. O monoterpeno mirceno, observado na amostra cubana, apresentou grande abund?ncia relativa (6,52%). Os d?pteros foram submetidos a diferentes concentra??es do ?leo de C. citratus (5, 10, 25, 75 e 100%) (Brasil/Cuba). As subst?ncias foram aplicadas topicamente nas neolarvas (1?L/larva). N?o houve grandes diferen?as entre a atividade do ?leo cubano e brasileiro. As esp?cies L. cuprina, M. domestica, C. megacephala tiveram o seu per?odo p?s-embrion?rio aumentado pelos dois ?leos (Brasil/Cuba), por?m em C. putoria ela apresentou um encurtamento no per?odo larval e no per?odo de neolarva a adulto. Todos os grupos tratados apresentaram deformidades. Os resultados do teste com o monoterpeno Citral mostraram que C. megacephala foi a esp?cie mais sens?vel matando 73% no per?odo larval e 77% no per?odo de neolarva a adulto e a esp?cie menos sens?vel foi C. putoria que apresentou 40% de mortalidade no per?odo larval e 57% no per?odo de neolarva a adulto. O Citral encurtou o per?odo p?s-embrion?rio das esp?cies M. domestica, L. cuprina e C. megacephala, por?m na esp?cie C. putoria ele atrasou. No segundo cap?tulo objetivou analisar a composi??o qu?mica do ?leo essencial de Pinus caribaea coletado no Brasil e Cuba, e avaliar a sua a??o e a do seu componente cariofileno sob o desenvolvimento p?s-embrion?rio analise da composi??o qu?mica do ?leo essencial de Cymbopogon citratus coletado no Brasil e Cuba, e da avalia??o do ?leo e do seu componente majorit?rio citral sob o desenvolvimento p?s-embrion?rio de Musca domestica, Chrysomya putoria, C. megacephala e Lucilia cuprina. Para o ?leo essencial obtido das folhas de P. caribaea coletadas no Brasil foram identificadas 12 subst?ncias qu?micas, sendo o ?-Felandreno (39,57%), Germacreno D (26,57%) e (E) Cariofileno (16,85%) os majorit?rios. A an?lise do ?leo das folhas de P. cariabea provenientes de Cuba resultou na identifica??o de 20 subst?ncias, sendo o Germacreno D (48,25%), ?xido de Cariofileno (12,41%) e ? Felandreno (12,10%) Germacreno D (48,25%) os constituintes majorit?rios. O Cariofileno mostrou ser mais t?xico para M. domestica com uma mortalidade de 87% na fase de neolarva a adulto e as esp?cies menos afetadas foram L. cuprina e C. megacephala com 83% de mortalidade e para C. putoria a mortalidade observada foi de 63%. O per?odo p?s- embrion?rio foi encurtado nas esp?cies M. domestica, L. cuprina e C. megacephala e aumentado em C. putoria. O peso pupal foi reduzido na maioria das esp?cies com exce??o de C. putoria que teve ele aumentado e n?o houve altera??o na propor??o sexual nas esp?cies estudadas.
233

The histopathology of lions (Panthera leo) suffering from chronic debility in the Kruger National Park

Ide, Annalize 09 March 2005 (has links)
Studies on the health status of lions (Panthera leo) in the Kruger National Park (KNP) have revealed certain lions suffering from chronic debility (“poor doers”). Clinical signs include chronic emaciation, renal failure and chronic bacterial infections. The diagnosis of Mycobacterium bovis in KNP lions in 1995 raised the question of whether these “poor doer” lions were suffering from tuberculosis. Tests confirmed tuberculosis in some cases, but no aetiology for the poor condition was found in a large percentage of the animals tested. Extensive literature review failed to reveal reports of similar findings of chronic debility in free living lion populations, although various disease outbreaks and infectious diseases of lions are described. These are briefly reviewed. Surveys have confirmed that the majority of the KNP lions are serologically positive for feline immunodeficiency virus (FIV), the clinical importance of which is questioned as a possible cause of immunosuppression in lions. Tissue samples from eleven lions suffering from chronic debility and six clinically healthy lions were studied by light microscopy. Changes in the various organ systems were reported and tabulated with reference to degree and relevance. Frozen lymph node samples from some animals in both groups were collected for immunohistochemical staining for T and B lymphocytes and CD4 and CD8 subsets. In some cases serology was done for FIV using a Puma Lentivirus ELISA and a Puma Lentivirus Western Blot technique. Mycobacterial culture results were available for some animals. The histopathological features varied, but notable changes were seen in the lymph nodes. These included generalized lymphoid hyperplasia (predominantly affecting clinically healthy lions), progressing through combined hyperplasia and atrophy in different nodes to lymphoid atrophy affecting most of the lions suffering from chronic debility. These are non-specific findings seen in various systemic diseases, including canine distemper virus infection and toxoplasmosis, but they have also been described in domestic cats suffering from FIV infection and humans with HIV. Further findings in lymph node sections included mineral deposition and multifocal cystic spaces. Other important histopathological changes included chronic interstitial pneumonia, renal amyloidosis, chronic interstitial nephritis, Wallerian degeneration of the spinal cord, encephalomalacia and anterior uveitis. Two animals suffered from multifocal, multisystemic granulomatous inflammation. Mycobacterium bovis was cultured from one of these cases, but no apparent aetiology could be found in the other. Eosinophilia was a consistent finding in many tissues and most likely related to the high parasite load in many of the animals. Parasites found included Hepatozoon spp., microfilaria, cestodes, nematodes and trematodes and Sarcocystis spp. and Trichinella spp. Immunohistochemical staining for B and T lymphocytes and CD4 and CD8 subsets showed a normal distribution of the staining pattern within the lymph node sections, although the samples were all from FIV positive lions. The histopathology in both study groups was of a non-specific nature and not indicative of any particular disease syndrome, although many of the changes are similar to those described in domestic cats infected with FIV. There are indications of possible immunocompromise in the “poor doer” lions, which warrants further investigation. / Dissertation (MMedVet (Pathology))--University of Pretoria, 2006. / Oral Pathology and Oral Biology / unrestricted
234

Lectures contemporaines de Machiavel: la question de l'interprétation chez Leo Strauss, Quentin Skinner et Claude Lefort

Marcotte Chénard, Sophie January 2011 (has links)
Dans cette thèse, nous cherchons à penser les enjeux philosophiques de l’application de méthodes herméneutiques en histoire de la philosophie politique. À partir d’une étude comparative des interprétations de l’œuvre de Nicolas Machiavel offertes par Leo Strauss, Quentin Skinner et Claude Lefort, nous interrogeons le rapport que l’interprète institue avec le texte qu’il étudie. Nous montrons qu’il y a dans les trois cas un écart entre l’exposition théorique des principes herméneutiques et l’application effective de ces derniers. Nous soutenons que les divergences fondamentales entre les trois lectures des écrits machiavéliens ne trouvent pas leur fondement dans la différence des méthodes employées, mais proviennent en dernier lieu de la compréhension particulière qu’ils ont du rôle et du statut de la pensée de Machiavel. Autrement dit, nous cherchons à montrer que l’intérêt pour la signification de l’œuvre machiavélienne dépasse la simple analyse des écrits d’un auteur du passé; les trois interprètes entretiennent un rapport singulier à la pensée du secrétaire florentin. En ce sens, l’étude des herméneutiques de Strauss, Skinner et Lefort appliquées à Machiavel est indissociable d’une interrogation sur l’articulation entre interprétation et politique.
235

Les racines grecques de la philosophie : theôria et praxis dans le platonisme de Hans-Georg Gadamer et Leo Strauss

Pageau St-Hilaire, Antoine January 2017 (has links)
Bien qu’ils soient généralement opposés sur la question de l’herméneutique et de l’historicisme, Hans-Georg Gadamer (1900-2002) et Leo Strauss (1899-1973) sont deux des plus grands représentants du retour contemporain à la pensée grecque, et plus particulièrement à Platon. Cette thèse cherche à éclairer le débat entre Gadamer et Strauss en insistant sur cet élément central de leurs philosophies respectives. En dépit de multiples accords interprétatifs sur les Dialogues, nous soutenons qu’un désaccord est également perceptible à même leurs lectures de Platon, à savoir qu’ils ne s’entendent pas sur la relation de la dimension théorétique et la dimension pratique de l’existence humaine dans la philosophie platonicienne. Nous cherchons d’abord à introduire les problématiques platoniciennes en analysant les réceptions gadamérienne et straussienne de l’interprétation d’Aristote proposée par Martin Heidegger dans les années 1920, laquelle influença de manière déterminante leur approche de Platon. Nous comparons ensuite leurs compréhensions de l’articulation entre theôria et praxis dans la philosophie platonicienne à l’égard de trois questions : 1) la signification pratique de la forme dialoguée ou dialogique de la philosophie ; 2) le rapport entre philosophie et poésie ; 3) le rapport entre politique et philosophie, a fortiori la philosophie comme recherche des Idées. En éclairant ainsi des points de convergence et de divergence entre Gadamer et Strauss en amont de la question de l’herméneutique et de l’historicisme, nous proposons un portrait plus complet et nuancé d’un dialogue qu’on tend trop souvent à réduire à une stricte opposition.
236

Guilda de abelhas coletoras de ?leo (APOIDEA) associada ? Byrsonima sericea e Byrsonima cydoniifolia (Malpighiaceae)

Lua, Shantala 22 March 2013 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-03-23T23:54:57Z No. of bitstreams: 1 Disserta??o ShantalaLua.pdf: 1071615 bytes, checksum: 15159372342693f6876667ee25762bff (MD5) / Made available in DSpace on 2016-03-23T23:54:57Z (GMT). No. of bitstreams: 1 Disserta??o ShantalaLua.pdf: 1071615 bytes, checksum: 15159372342693f6876667ee25762bff (MD5) Previous issue date: 2013-03-22 / Floral oil-collecting bees have close relations with Malpighiaceae species. This study aims to characterize the bee guilds that visit two Byrsonima (Malpighiaceae) species and investigate if the variation in floral oil supply influences on the richness and local abundance of these bees in an area in Chapada Diamantina. Bees were collected using entomological nets during the visit to Byrsonima and the floral oil supply was estimated at 12 transects through the Byrsonima spp density and the amount of oil available per flower and per plant. A large variation in Byrsonima spp density was detected among the 12 transects sampled what resulted in differences in floral oil supply among transects (1320.4g-16397.2g). The sample was 638 individuals belonging to 34 Apoidea species, being 24 species components of the floral oil-collecting bee guild. Centridini was the tribe with the largest representation of species richness and in abundance. The richness and abundance of Centridini were positively correlated to both Byrsonima spp density and the amount of oil estimated to each transect. However, the richness and abundance of Tapinotaspidini and Tetrapediini didn?t correlate to Byrsonima spp density or the amount of oil estimated to each transect. / As abelhas coletoras de ?leos florais apresentam rela??es bastante estreitas com esp?cies de Malpighiaceae. Este estudo tem como objetivo caracterizar a guilda de abelhas que visitam duas esp?cies de Byrsonima (Malpighiaceae) e investigar se a varia??o na oferta de ?leo floral influencia na riqueza e abund?ncia local destas abelhas, em uma ?rea na Chapada Diamantina. As abelhas foram coletadas com redes entomol?gicas durante a visita ?s flores de Byrsonima e a oferta de ?leo floral foi estimada em 12 transectos, atrav?s das medidas de densidade de Byrsonima spp e da quantidade de ?leo disponibilizada por flor e por planta. Foi detectada uma grande varia??o na densidade de Byrsonima spp entre os 12 transectos amostrados, o que resultou em diferen?as na oferta de ?leos florais entre os transectos (1320,4g-16397,2g). Foram amostrados 638 indiv?duos, pertencentes a 34 esp?cies de Apoidea, sendo 24 esp?cies componentes da guilda de abelhas coletoras de ?leo. Centridini foi a tribo com maior representatividade, tanto em riqueza de esp?cies quanto em abund?ncia. A riqueza e abund?ncia de Centridini estiveram positivamente correlacionadas tanto com a densidade de Byrsonima spp quanto com a quantidade de ?leo estimada para cada transecto. Entretanto a riqueza e abund?ncia de Tapinotaspidini e Tetrapediini n?o apresentaram correla??o nem com a densidade de Byrsonima spp, nem com a quantidade de ?leo estimada para cada transecto.
237

Stochastic Geometry-based Analysis of LEO Satellite Communication Systems

Talgat, Anna 21 July 2020 (has links)
Wireless coverage becomes one of the most significant needs of modern society because of its importance in various applications such as health, distance education, industry, and much more. Therefore, it is essential to provide wireless coverage worldwide, including remote areas, rural areas, and poorly served locations. Recent advances in Low Earth Orbit (LEO) satellite communications provide a promising solution to address these issues in poorly served locations. The thesis studies the performance of a multi-level LEO satellite communication system. More precisely, we model the LEO satellites’ location as Binomial Point Process (BPP) on a spherical surface at n different altitudes given that the number of satellites at each altitude ak is Nk where 1 ≤ k ≤ n and study the distance distribution. The distance distribution is characterized in two categories depending on the location of the observation point: contact distance and the nearest neighbor distance. For that proposed model, we study the user coverage probability by using tools from stochastic geometry for a scenario where satellite earth stations (ESs) with two antennas are deployed on the ground where one of the antennas communicates with the user while the other communicates with LEO satellite. Additionally, we consider a practical use case where satellite communication systems are deployed to increase coverage in remote and rural areas. For that purpose, we compare the coverage probability of the satellite-based communication system in such regions with the coverage probability in case of relying on the nearest anchored base station (ABS), which is usually located at far distances from rural and remote areas.
238

Arterial supply and histology of the female reproductive organs of the African lion (Panthera leo)

Hartman, Marthinus Jacobus January 2013 (has links)
This masters project was undertaken to have a better knowledge of the female lion reproductive tract and to equip the author for future surgical studies on this organ system. The objectives of this study were to describe the arterial supply and histology of the female reproductive organs of the African lion. The reproductive organs of three embalmed cadavers and two fresh carcasses from three-year-old known aged nulliparous lionesses weighing between 120 kg and 140 kg were studied. The project was approved by the Animal Use and Care Committee and Research Committee of the University of Pretoria (protocol number V038-09). The arterial supply of the reproductive organs was studied and described in situ and after removal and histology was subsequently performed. A novel technique in Veterinary anatomy involving the maceration of a silicone cast was used in the two fresh carcasses and all five specimens were incorporated in the comparative and arterial studies. Histology was performed on organs from the three embalmed cadavers. The anatomical information obtained during this study was subsequently applied in a surgical study on sixteen lionesses using laparoscopy to perform laparoscopic ovariectomy and salpingectomy. The availability of these two laparoscopic procedures subsequently led to a wider interest to its application in population control of lions in the smaller national parks of South Africa. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Anatomy and Physiology / unrestricted
239

California As Music to American Ears: Migration, Technology, and Rock and Roll in the Golden State, 1946–2000

Willett, Toby T 01 March 2010 (has links) (PDF)
Migrations and technological advances in California following World War II, spurred radical changes in the production and development of popular music, most notably rock and roll. California largely lacked the entrenched traditions of the American Northeast, and in many ways its exploding population translated into the growth of a culture built around embracing newer methodologies, whether technological innovations or radical artistic departures. In large part owing to its increasing ethnic diversity during the economic expansion, California was uniquely poised to become a center of incredible postwar dynamism, especially when seen in the production, consumption, and stylistic development of music. Nevertheless, many of the radical departures in American music were contingent upon the contributions of a small group of inter-connected musical equipment manufacturers and musicians in California from the 1940s through the 1960s. As the United States experienced dramatic changes during the awesome postwar boom, Californian artists, merchants, and equipment makers exploited opportunities, making the Golden State the national trendsetter in musical developments both technological and stylistic. In particular, the invention, development, and further refinement of solid bodied electric guitars and basses in Southern California permanently changed how music would be made. The transformation of West Coast music would produce differing reactions nationally, while foreign developments would impact California, challenging its hegemony.
240

Atomic Oxygen Considerations for LEO De-orbit Trajectories Using Solar Sails

Fugett, Daniel A. 01 June 2017 (has links) (PDF)
Solar sails have the potential to benefit many future space exploration missions, but they lack the heritage required for present-day use. To grow confidence in solar sail technology, they could be deployed on LEO satellites higher than 600 km to help de-orbit the satellite within 25 years upon mission termination. To determine how atomic oxygen would affect the solar sail, material from Lightsail-2 was tested in a thermal-energy, isotropic, atomic oxygen vacuum chamber based in the space environments laboratory in California Polytechnic State University. The sail material, aluminized Mylar, was tested for its survivability on both the coated and uncoated side, as well as tested for the optical degradation of the coated side. The uncoated side was found to be completely eroded after a fluence of 2.27 x1020 atoms/cm2, or ~40 days in International Space Station orbit. The coated side experienced no mass loss, but signs of significant undercutting were found with a fluence of 1.19 x1021 atoms/cm2, or ~200 days at station orbit. The stitches present on the coated side, meant to prevent tear propagation, eroded before the sample experienced a fluence of 4.13 x1020 atoms/cm2, or ~70 days at station orbit. The average total reflectivity of the material dropped by ~5% after atomic oxygen exposure, however no correlation with fluence was found. Average specular reflectivity remained unchanged after atomic oxygen exposure. The reflectivity results were impacted by wrinkling in the material, which was found to have a much larger impact than atomic oxygen exposure. These results were paired with an optimal de-orbit trajectory algorithm, developed in this thesis, to determine how atomic oxygen would affect a solar sail deployed to de-orbit an 800 km LEO satellite with a ballistic coefficient of 0.1. Using a simplified 2D orbit case, it was found that the satellite would de-orbit within 12-18 years, depending primarily on the solar activity level. The measured worst-case for optical degradation increased de-orbit time by ~6 months. Additionally, assuming that the sail material was perfectly reflecting decreased de-orbit time by 2-4 years. The amount of fluence required to erode the uncoated Mylar, and the amount required to erode the stitches, were both reached long before the satellite re-entered. It is therefore recommended that the solar sail minimize uncoated side exposure to atomic oxygen, and a more atomic oxygen-resistant stitch material be found. The fluence required to produce significant material undercutting was reached only once the satellite’s orbit had degraded to below 400 km. But the undercutting was observed to structurally compromise the material; thus, future LEO solar sail mission designers must take care when balancing added performance with higher failure risk when considering the tension in the deployed sail.

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