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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.
221

Analysis of shallow seismicity and stress fields in Southeastern Alaska

Rodriguez, Hugo, January 2009 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
222

Structure and salt tectonics of Messinian evaporites in the Cilicia Basin, eastern Mediterranean /

Bridge, Colleen, January 2004 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 244-253. Also available online.
223

Kinematics and dynamics of the Pacific-North American plate boundary in the western United States /

Fay, Noah Patrick, January 2006 (has links)
Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 118-140). Also available for download via the World Wide Web; free to University of Oregon users.
224

Sequence stratigraphic evolution of the Albian to recent section of the Dampier Sub-basin, North West Shelf, Australia

Hull, Jonathan N. F. January 1999 (has links) (PDF)
Four folded maps in pocket on back cover. Copy of author's previously published work inserted. Includes bibliographical references (9 leaves). An integrated biostratigraphic, wireline, seismic, lithological and 3D-Chronostrat sequence stratigraphic study has been conducted to investigate the evolution of the Albian to recent section of the Dampier Sub-basin on Australia's North West Shelf,.
225

Μελέτη και διάγνωση σφαλμάτων στάτη ασύγχρονης μηχανής με τη μέθοδο πεπερασμένων στοιχείων

Τζελέπη, Σοφία-Βασιλική 24 October 2012 (has links)
Στην παρούσα διπλωματική εργασία ασχοληθήκαμε με το θέμα της μελέτης και διάγνωσης σφαλμάτων στάτη μιας ασύγχρονης μηχανής. Μοντελοποιήθηκε και αναλύθηκε η λειτουργία ενός ασύγχρονου τριφασικού κινητήρα κλωβού, σε υγιή κατάσταση αλλά και υπό συνθήκες σφάλματος. Πιο συγκεκριμένα, με τη χρήση του προγράμματος πεπερασμένων στοιχείων σε δυο διαστάσεις εξομοιώθηκαν πιθανά σφάλματα στο στάτη της ασύγχρονης μηχανής. Αναλυτικότερα, στο πρώτο κεφάλαιο παρουσιάζονται κάποιες βασικές αρχές λειτουργίας των ασύγχρονων μηχανών, μελετώνται τα κυριότερα σφάλματα που συναντώνται σε αυτές τις μηχανές και παρουσιάζονται οι γνωστότερες διαγνωστικές μέθοδοι σφαλμάτων που υπάρχουν στη βιβλιογραφία. Κυρίως αναλύεται η μέθοδος διάγνωσης σφαλμάτων που χρησιμοποιεί την ανάλυση στο πεδίο της συχνότητας του ρεύματος στάτη (MCSA) η οποία και χρησιμοποιείται τελικά για τη διάγνωση των συγκεκριμένων σφαλμάτων. Ειδικότερα, μελετήθηκαν δυο ειδών σφάλματα στάτη, τα οποία είναι πιθανόν να συμβούν σε αυτήν τη μηχανή, το βραχυκύκλωμα κάποιων σπειρών εντός της ίδιας αυλάκωσης μιας φάσης και το βραχυκύκλωμα σπειρών σε δυο γειτονικές αυλακώσεις της ίδιας πάλι φάσης του στάτη τα οποία και μελετώνται αναλυτικά παρακάτω. Στο επόμενο κεφάλαιο εξομοιώθηκαν τα δύο μοντέλα με σφάλμα, όπως προαναφέρθηκε με χρήση του προγράμματος πεπερασμένων στοιχείων κάνοντας όλες τις απαραίτητες τροποποιήσεις στις παραμέτρους των αρχικών μοντέλων ώστε να απεικονιστούν στα μοντέλα τα σφάλματα που επιθυμούμε. Στο τρίτο κεφάλαιο παρουσιάζονται όλες οι γραφικές παραστάσεις των ηλεκτρομαγνητικών μεγεθών για όλες τις περιπτώσεις όπως αυτές προέκυψαν από την ανάλυση με το πρόγραμμα της Opera -2d. Συγκεκριμένα, τα μοντέλα αναλύθηκαν με έναν επιλυτή που λαμβάνει υπ’ όψιν και την κίνηση του δρομέα (RM solver), όπου ενώ η μηχανή στρέφεται με σταθερό αριθμό στροφών στην ονομαστική κατάσταση βλέπουμε τη συμπεριφορά της με και χωρίς τα σφάλματα. Στο τελευταίο κεφάλαιο χρησιμοποιούνται οι διαγνωστικές μέθοδοι για την ανίχνευση των σφαλμάτων και παρατίθενται τα αποτελέσματά τους. Πιο συγκεκριμένα, αναλύθηκε το φάσμα συχνοτήτων των κυματομορφών του ρεύματος στάτη και της ηλεκτρομαγνητικής ροπής (FFΤ), ώστε να εντοπιστούν οι συχνότητες στις οποίες εισάγονται αρμονικές λόγω του σφάλματος. Επίσης μελετήθηκε η μορφή της χρονικής συνάρτησης του μαγνητικού πεδίου σε ορισμένα χαρακτηριστικά σημεία της μηχανής. Τέλος παρατίθενται τα συμπεράσματα , μαζί με την συνεισφορά της εργασίας καθώς και θέματα για διερεύνηση. / In this paper we dealt with the topic of the study and diagnosis of errors stator asynchronous machine. Modeled and analyzed the function of a three-phase asynchronous motor cage, but in a healthy state and under fault conditions.
226

Determinacao da energia de defeito de empilhamento em metais e ligas com estrutura cubica de face centrada por difracao de raios-X

BORGES, JOSE F.A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:56Z (GMT). No. of bitstreams: 1 02299.pdf: 1814894 bytes, checksum: cf49ad3b5d16cf422dd5e56dd657a29f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
227

Identificação e quantificação de bismuto total em amostras de solo em regiões de falhas geológicas por análise eletroquímica / Electrochemical determination of lead and bismuth radioisotopes in geological fault zones and its correlation

Borsato, Natíza Graziele Martins [UNESP] 11 August 2017 (has links)
Submitted by Natíza Graziele Martins Borsato null (natiza_gmb@hotmail.com) on 2017-09-22T13:29:54Z No. of bitstreams: 1 DEFESA Natiza G M Borsato.pdf: 2718459 bytes, checksum: 27005db75663dcc081fd9ab405793b95 (MD5) / Rejected by Monique Sasaki (sayumi_sasaki@hotmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2017-09-27T18:30:18Z (GMT) / Submitted by Natíza Graziele Martins Borsato null (natiza_gmb@hotmail.com) on 2017-10-04T02:10:48Z No. of bitstreams: 1 DEFESA Natiza G M Borsato.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-10-04T17:27:11Z (GMT) No. of bitstreams: 1 borsato_ngm_me_sjrp.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) / Made available in DSpace on 2017-10-04T17:27:11Z (GMT). No. of bitstreams: 1 borsato_ngm_me_sjrp.pdf: 2725342 bytes, checksum: 2ca43e2f0da0345b3a705c0777b90ef3 (MD5) Previous issue date: 2017-08-11 / No presente trabalho estudou-se, a concentração de bismuto total em áreas com falhas tectônicas e sua correlação com os níveis de radioisótopos de chumbo e de emissão de radônio-222. As determinações de bismuto total em diferentes solos foram realizadas por análise eletroquímica pela técnica de voltametria de redissolução anódica. Os valores de bismuto total aumentaram de acordo com o aumento da profundidade na extração do solo em estudo. Evidenciando a existência de bismuto decorrente da emanação de radônio-222 e sugerindo a existência de falhas geológicas nas áreas estudadas. Por análise estatística (ANOVA) verificou-se uma correlação da concentração de chumbo total e o nível de emissão de radônio-222 com a concentração de bismuto total. Essa correlação indica que a fonte de bismuto é proveniente da cadeia de decaimento radioativo do urânio-238 e tório-232. / In this work, the total concentration of bismuth areas with tectonic faults and their correlation and their correlation with the levels of lead radioisotopes and radon-222 emission. The determination of total bismuth in different soils were performed by electrochemical analysis using anodic redissolution voltammetry technique. The total bismuth values increased according to the depth increase in the extraction of the soil under study, evidencing the existence of bismuth due to the emanation of radon-222 and suggesting the existence of geological faults in the studied areas. Statistical analysis (ANOVA) showed a correlation between the total lead concentration and the emission level of radon-222 with the total bismuth concentration. This correlation indicates that the bismuth source is from the radioactive decay chain of uranium-238 and thorium-232.
228

Determinacao da energia de defeito de empilhamento em metais e ligas com estrutura cubica de face centrada por difracao de raios-X

BORGES, JOSE F.A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:56Z (GMT). No. of bitstreams: 1 02299.pdf: 1814894 bytes, checksum: cf49ad3b5d16cf422dd5e56dd657a29f (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
229

[en] FAULT TOLERANCE IN DISTRIBUTED SYSTEMS / [pt] RECUPERAÇÃO DE ERROS EM SISTEMAS DE PROCESSOS DISTRIBUÍDOS

ALEXANDRE DE REZENDE ABIBE 27 December 2006 (has links)
[pt] Esta dissertação aborda o problema da recuperação de erros em sistemas distribuídos. Inicialmente, é feita uma breve análise sobre a origem deste problema e as soluções encontradas. Alguns métodos de resolução são então apresentados. Para a simulação do sistema distribuído foi desenvolvido um núcleo multi-tarefa numa máquina compatível com o PC-IBM-XT, utilizando o MS-DOS (versão 3.0 ou acima) como servidor. Finalmente, são apresentadas duas propostas. A primeira visa fornecer a um processo recursos que possibilitem a recuperação por retorno. A segunda utiliza redundância em um conjunto de processos em diferentes estações para garantir que o sistema como um todo continue operativo, mesmo com uma estação de falha / [en] This dissertation deals with the problem of fault tolerance in distributed systems. Initially, a brief analysis on the origins of this problem and its solutions is made. Some of the resolutions methods are then presented. In order to simulate a distributed system, a multi tasking operating system kernel was developed in an IBM PC-XT compatible machine, making use of the MS-DOS (version 3.0 or above) as a server. Finally, two proposals are presented. The first, is intended to supply a process with resources that allow recovery in case of algorithmic faults, making use of the backward error recovery method. The second, uses redundancy in a set of processes over different stations in order to warrant that the system as a whole keeps operative, even with a faulty s
230

Interpretation of a seismic refraction profile from the Richardson Mountains, Yukon territory

O'Brien, Simon January 1990 (has links)
In March of 1987, the Geologic Survey of Canada conducted a major seismic refraction experiment in the Mackenzie Delta-Southern Beaufort Sea-Northern Yukon area. This study involves the analysis of a portion of the resulting data set. A 2D velocity profile through the Richardson Mountains of the northern Yukon has been constructed using raytracing to model the travel-times and amplitudes. The line is approximately 320 km long, running from a shotpointon the Eagle Plains in the south to one 50 km offshore in Mackenzie Bay to the north, with an average receiver spacing of 3.5 km. An additional shotpoint is located at Shingle Point, on the shore of Mackenzie Bay. A series of four sedimentary basins separated by major structural highs produces a complex basement structure. Two distinct upper crustal layers were modelled, a 5.95 km/s layer overlying a 6.3 km/s layer, as well as a lower crustal layer with a velocity of 7.25 km/s. Crustal velocity gradients are low (≤ 0.005 s⁻¹). The 6.3 km/s layer pinches out beneath the Beaufort-Mackenzie Basin in the north, accompanied by a thinning of the lower crust from a thickness of 20 km in the south to less than 10 km beneath MB. This results in the crust as a whole thinning from a thickness of 50 km under the Richardson Mountains to only 40 km under the Beaufort-Mackenzie Basin. The velocity of the upper mantle is 7.95 km/s. The modelling of shear wave arrivals indicate Poisson's ratios of 0.23 ±0.02 in the upper crust and 0.25 + 0.02 in the lower crust. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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