Dissertations / Theses on the topic 'Magnetism history'
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CALI, ELISA. "Data Analysis and Pattern Recognition in a Magnetometer Experiment." Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1214194.
Full textWhiting, Thomas H. "A study of the lithology and structure of the eastern Arunta Inlier based on aeromagnetic interpretation : a lithological subdivision and structural history of the eastern Arunta Inlier, with particular emphasis on the relationship between magnetic mineral petrogenesis, rock magnetism and aeromagnetic signature /." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phw6125.pdf.
Full textBaias, Maria Antoaneta. "Science and history explored by nuclear magnetic resonance." Aachen Shaker, 2009. http://d-nb.info/99887499X/04.
Full textMorton, David Lindsay Jr. "The History of magnetic recording in the United States, 1888-1978." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/24235.
Full textColeman, Jessica. "Applying Geoarchaeological Methods on an Iron Age site : Part two of a two-part study discussing Archaeological Prospection for Ytings, Gotland." Thesis, Umeå universitet, Institutionen för idé- och samhällsstudier, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-185792.
Full textBaias, Maria Antoaneta [Verfasser]. "Science and history explored by nuclear magnetic resonance / vorgelegt von Maria Antoaneta Baias." Aachen : Shaker, 2009. http://d-nb.info/1002320704/34.
Full textJones, J. M. "Magnetic minerals and heavy metals in ombrotrophic peat." Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372671.
Full textClarke, Michèle Louise. "Formation, depositional history and magnetic properties of loessic silt from the Tibetan Front, China." Thesis, University of Leicester, 1992. http://hdl.handle.net/2381/34479.
Full textDussauge, Isabelle. "Technomedical Visions : Magnetic Resonance Imaging in 1980s Sweden." Doctoral thesis, Stockholm : Filosofi och teknikhistoria, Philosophy and the History of Technology, Kungliga Teknsika högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4671.
Full textMartineau, Ryan J. "Parameterized Least-Squares Attitude History Estimation and Magnetic Field Observations of the Auroral Spatial Structures Probe." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4482.
Full textWilder, Douglas T. "Relative Motion History of the Pacific-Nazca (Farallon) Plates since 30 Million Years Ago." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000069.
Full textDitty, Melissa Lynn. "FINDING MARS PALEOPOLES FROM MAGNETIZATION EDGE EFFECTS TO DETERMINE THE HISTORY OF MARS’ CORE DYNAMO." UKnowledge, 2015. http://uknowledge.uky.edu/ees_etds/30.
Full textJordan, D. W. "Authority, mediation, and response case studies in electrotechnical theory 1880 - 1890." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315221.
Full textWillis, Tracey Anne. "A natural history study in Limb Girdle Muscular Dystrophy 2I : magnetic resonance imaging, spectroscopy and physical outcome measures." Thesis, University of Newcastle upon Tyne, 2012. http://hdl.handle.net/10443/1595.
Full textHendricks, Hays Birkhead. "Louisville's Lustrons : houses with magnetic appeal." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/897512.
Full textDepartment of Architecture
Smith, Dominic. "Magnetics and Electromagnetics on Monks Mound at the Cahokia Mounds State Historic Site near St. Louis, Missouri." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1674100591&sid=3&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text"Department of Geology." Keywords: Cahokia Mounds, Electromagnetics, Magnetics, Monks Mound. Includes bibliographical references (p. 143-148). Also available online.
Cerf, Corinne. "Structure of the globular domain of histone H1 determined by nuclear magnetic resonance." Doctoral thesis, Universite Libre de Bruxelles, 1994. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212678.
Full textLUZZAGO, STEFANO. "REPEATED MRI SCANS DURING ACTIVE SURVEILLANCE FOR PROSTATE CANCER: NATURAL HISTORY OF PROSTATIC LESIONS AND UPGRADING RATES OVER TIME." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/881234.
Full textSullivan, Nicholas B. "Refinements to the Depositional History of Lower Silurian Strata in the Northeastern United States by means of Conodont Biostratigraphy, d13C Chemostratigraphy, Sequence Stratigraphy, and Magnetic Susceptibility." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112630.
Full textSpurgeon, V. Leanne. "Sedimentology of historic and prehistoric deposits in the drainage basin of Deep River and Muddy Creek on the Piedmont of North Carolina." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1268.
Full textTitle from document title page. Document formatted into pages; contains viii, 152 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 62-64).
Di, Chiara Anita <1983>. "Paleosecular variation of the magnetic field recorded in Pleistocene-holocene volcanics from Pantelleria (italy) and Azores archipelago (portugal): implications for local volcanic history." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5177/1/DI_CHIARA_ANITA_TESI.pdf.
Full textDi, Chiara Anita <1983>. "Paleosecular variation of the magnetic field recorded in Pleistocene-holocene volcanics from Pantelleria (italy) and Azores archipelago (portugal): implications for local volcanic history." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5177/.
Full textBoland, Paul William. "Morphometric analysis of data inherent in examination by magnetic resonance imaging : importance to natural history, prognosis and disease staging of squamous carcinoma of the oral cavity." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:934e1e5a-24db-40ab-ab54-5e58901a9c2a.
Full textRaúl, Sitoe Sandra. "Environmental history in southern Mozambique : Reconstruction of flooding events, hydroclimate and sea-level dynamics since mid-Holocene." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148465.
Full textDenna avhandling behandlar studier av paleomiljöer i södra Mozambique med fokus på översvämningshistorik i Limpopo-flodens nedre lopp. Tidsspannet är mitt- och sen-holocen och inkluderar även klimat och havsnivåvariationer. Följande analysmetoder har applicerats på ett flertal sedimentkärnor för att belysa ovanstående frågeställningar: mineralmagnetiska parameterar, kornstorlek, organiskt kol samt kiselmikrofossil (diatoméeter och fytoliter). Åldrar har bestämts med 14C-metoden. Analyserna visar att mineralmagnetiska parametrar är lämpliga för att identifiera översvämningar, speciellt magnetisk susceptibilitet och SIRM. Dessa parametrar visar på ett sediments magnetiska kornstorlerkar och koncentrationen av finkorniga magnetiska mineral. Även kornstorleksanalyser fungerade som ett bra komplement till dessa metoder. Sammantaget har ett minimum av 16 översvämningar registrerats i Limpopo/flodens nedre lopp under de senaste 1100 åren. Särskilt stora översvämningar har daterats till AD 1250 (700 kal år BP), AD 1370 (580 kal år BP), AD 1580 (370 kal år BP), AD 1855 (95 kal år BP), AD 1920 (30 kal år BP), AD 1970 (20 kal år AP) och AD 2000 (50 kal år AP), där AP betyder ”after present”, vilket är 1950. Mindre kraftiga översvämningar har daterats till AD 940 (1010 kal år BP), AD 980 (970 kal år BP), AD 1040 (910 kal år BP), AD 1100 (850 kal år BP), AD 1300 (650 kal år BP), AD 1665 (285 kal år BP), AD 1730 (220 kal år BP), AD 1755 (195 kal år BP) och AD 1945 (5 kal år BP). Skriftliga källor visar på att åtminstone åtta översvämningar har ägt rum under de senaste 62 åren. Under samma period har denna undersökning registrerat två händelser, vilket indikerar att endast ett fåtal har registrerats med ovan nämnda metoder. Det är sannolikt att sedimentationsmönstret under en översvämning är komplicerat och inte heller likartad från gång till gång. Detta innebär att ett flertal sedimentkärnor behöver analyseras och dateras väl. Ytterligare en försvårande faktor är flodens mycket aktiva meandringsaktivitet. Analys av diatoméer har visats vara värdefulla när det gäller översvämningshistorik, klimatförändringar och havsytevariationer. Sedimenten i den något till flodslättens nedre lopp perifert belägna sjön Lungué indikerar fuktiga förhållanden mellan AD 1360 och 1560 (590 till 390 kal år BP). Kombinerade fytolit- och diatoméanalyser av sedimenten i sjön Chilau indikerar fuktiga förhållanden från AD 1200 till 1400 (750 till 550 kal år BP), varefter torrare förhållanden rådde till ca AD 1600 (350 kal år BP). Diatoméanalys av sedimenten i sjön Nhauhache indikerar generellt sett torrare förhållanden mellan AD 1200 och AD 1700 (750 till 250 kal år BP) då klimatet blev fuktigare. De fuktiga och torra förhållanden som dokumenterats i sjön Lungué och översvämningshistoriken korrelerar inte helt med lokala nederbördsförhållanden. Däremot stämmer erhållna data bättre med förhållanden i den övre delen av Limpopoflodens dräneringsområde. Även sjöar och fyllda meanderbågar på själva flodslätten verkar reagera tydligare på översvämningar orsakade av nederbörd i den övre delen av flodloppet. Undersökningen indikerar två faser av en förhöjd havsyta längs kusten i södra Mozambique. En äldre fas är daterad till ca 5000–4200 f.Kr. (6950–6150 kal år BP), vilken representerar den mellersta delen av det postglaciala värmeoptimet. Denna tolkning stöds även av andra undersökningar. En yngre fas har daterats till AD 300–950 (1650–1000 kal år BP), vilken korresponderar till en period med något förhöjda temperaturer i ett globalt perspektiv.
O presente projecto teve como objectivo a reconstrução do paleoambiente, paleohidrologia e paleoclima da costa Sul de Moçambique, com ênfase na identificação de vestígios de eventos de cheias que tenham, no passado, afectado a planície de inundação do Rio Limpopo, com vista a fazer a extensão das datações de cheias para o período anterior aos instrumentos de medição. Deste modo, foram estudados sedimentos recuperados através de testemunhos de sondagem em lagos dentro da planície de inundação (Lago Magandane, Lago Lungué, Lago Soane e o canal abandonado Coassane). As variações do nível do mar e mudanças climáticas do passado foram deduzidas a partir da análise de sedimentos de áreas costeiras a norte da planície de inundação (Lago Chilau, Lago Nhauhache e a Baía de Macassa). Para o alcance destes objectivos, os sedimentos dos testemunhos de sondagem recuperados foram submetidos a várias análises laboratoriais que incluem propriedades de minerais magnéticos, granulometria, teor de matéria orgânica e de microfósseis (diatomáceas e fitólitos). Para o estabelecimento do modelo cronológico foram usadas datações pelo método 14C feitas em matéria orgânica, assim como conchas de gastrópodes e bivalves. A combinação dos resultados obtidos para os pontos de amostragem localizados dentro da planície de inundação do Rio Limpopo, sugerem que esta área foi afectada por um mínimo de 16 eventos de cheias de variada magnitude nos últimos 1100 anos. As cheias de alta magnitude tiveram lugar nos anos 1250, 1370, 1580, 1855, 1920, 1970 e 2000. Por seu turno, as cheias de magnitude moderada ocorrerram nos anos 940, 980, 1040, 1100, 1300, 1665, 1730, 1755 e 1945.. Os anos a negrito são indicativos de eventos de cheias de alta magnitude. O número total de eventos identificados no presente estudo é um mínimo que poderá ter afectado a planície de inundação, tendo em consideração que fontes escritas reportam a ocorrência de pelo menos oito eventos nos últimos 62 anos, tendo o presente estudo revelado somente dois. Isto indica que apenas eventos de cheias intensos podem ser revelados pelos métodos aplicados nesta investigação. Adicionalmente, este estudo mostra a necessidade de aumentar o número de pontos de amostragem para permitir a identificação de mais eventos de cheias ocorridos no passado, devido à diferenciada resposta sedimentológica e geomagnética às cheias, a qual se encontra directamente relacionada à distância do rio meandrante. As análises de microfósseis de diatomáceas permitiram reconstruir o paleoclima e as influências do nível do mar nas áreas de estudo deste projecto. Os registros de diatomáceas do Lago Lungué indicam um período húmido entre AD 1360 e 1560. No Lago Chilau, dados de diatomáceas e fitólitos sugerem condições de humidade entre AD 1200 e 1400. Por seu turno, no Lago Nhauhache, condições de seca dominam entre AD 1200 e 1700. As condições de seca e humidade documentadas no Lago Lungué e os eventos de cheias revelados pelos sedimentos analisados da planície de inundação do Rio Limpopo não mostram total correlação com períodos de baixa e alta precipitação a nível local, mas apresentam boa correlação com evidências a montante na área de drenagem do Rio Limpopo. Em geral, lagos activos ou preenchidos por sedimentos mostrarão ser mais susceptíveis a cheias com origem a montante do que a nível local. As investigações conduzidas permitiram identificar dois períodos de alto nível do mar na região sul de Moçambique. A fase mais antiga teve lugar há cerca de 5000–4200 BC (6950–6150 anos do calendário BP), representando a fase mais recente do pós-glaciar climático óptimo (postglacial climatic optimum, PCA). A fase recente é datada de AD 300–950 (1650–1000 anos do calendário BP), correspondendo a um período de temperaturas relativamente altas a nível global.
Climate and Environmental Research
Farwig, Victoria Jane. "Evaluation of mineral magnetic properties and thermal activation characteristics of soil material in reconstructing post-fire sediment redistribution and fire history, Sydney Basin, Australia." Thesis, Swansea University, 2006. https://cronfa.swan.ac.uk/Record/cronfa43195.
Full textMagalhães, Antônio de Pádua. "Matéria Elétrica e Forma Magnética: Experimentos e concepções de William Gilbert no De Magnete." Pontifícia Universidade Católica de São Paulo, 2007. https://tede2.pucsp.br/handle/handle/13358.
Full textWilliam Gilbert of Colchester (1544-1603), one of the many personal physicians of Queen Elizabeth the First, was a prominent figure regarding the studies of electric and magnetic phenomena between the end of the XVI century and the beginning of the XVII century. In his attempt to reformulate the approach given to knowledge about the nature of these phenomena in his days, as well as the appropriate way to elaborate such process, William Gilbert would then develop various original and influent works, which would be published in the year of 1600 in his book De Magnete. His declared purpose would be to establish a new philosophy based on arguments and true observations, demonstrated by experiments and experiences. Consequently, he would then create new concepts and conceptions about the nature of electric and magnetic matter. The present work aims to go further in the analysis of this specific book, undertaking initially some aspects of its structure, editions and repercussions, as well as the rare biographical data on the author. Next, we investigate the relationship between De Magnete and some of the sources suggested by the author. Particularly those concerning the experiments regarding the magnetic phenomenon, specially the Epistola attributed to the medieval thinker Petrus Peregrinus, The New attractive (1581), written by the navigation craftsman Robert Norman. We also take into consideration, William Gilbert s criticism of book VII of Magia Naturalis (1558) written by the renaissance magician, Giambattista della Porta. We finally deal with the conceptions of electric matter and magnetic form proposed by William Gilbert. The study of the attractions would force him to separate electric bodies, imperfect for acting through matter, from magnetic bodies, perfect for acting through form. Therefore, form should present similarity with a superior soul and a resemblance with the skies
William Gilbert de Colchester (1544-1603), um dos muitos médicos pessoais da Rainha Elizabeth I, foi uma das mais destacadas figuras no que diz respeito aos estudos sobre os fenômenos elétrico e magnético entre o final do século XVI e início do século XVII. Em sua tentativa de reformular a abordagem dada ao conhecimento sobre a natureza desses fenômenos, em seus dias, bem como a própria maneira de elaborá-lo, William Gilbert desenvolveria trabalhos em muitos pontos originais e influentes, que seriam publicados, no ano de 1600, em seu livro De Magnete. Seu objetivo declarado seria estabelecer uma nova Filosofia baseada em argumentos e observações verdadeiros, demonstrados por experimentos e experiências. Assim, ele criaria novos conceitos e concepções sobre a natureza da matéria elétrica e magnética. O presente trabalho propõe-se a aprofundar a análise dessa obra, retomando inicialmente alguns aspectos de sua estruturação, edições e repercussões, bem como os raros dados biográficos de seu autor. Em seguida, busca-se investigar relações dessa obra com algumas das fontes sugeridas pelo autor, particularmente aquelas concernentes a experimentos relacionados ao fenômeno magnético, em especial a Epistola atribuída ao pensado medieval Petrus Peregrinus, o The New attractiue (1581), escrito pelo artesão náutico Robert Norman e também as críticas que William Gilbert desferiu contra o livro VII do Magia Naturalis (1558) escrito pelo mago renascentista, Giambattista della Porta. Por fim abordam-se as concepções de matéria elétrica e forma magnética propostas por William Gilbert. O estudo das atrações exigia-lhe separar os corpos elétricos, imperfeitos por atuarem através da matéria, dos corpos magnéticos, perfeitos por atuarem através da forma. Dessa maneira, a forma deveria apresentar similaridade com uma alma superior, à semelhança dos céus
Roberts, Jody Alan. "Instruments and Domains of Knowledge: The Case of Nuclear Magnetic Resonance Spectroscopy, 1956-1969." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/42766.
Full textMaster of Science
Yeh, Ping-Hong. "Traumatic osteochondrosis of the third metacarpal bone condyle in thoroughbred racehorses : gross, histological, high detail radiographic, microradiographic and magnetic resonance imaging findings and their relationships with exercise history /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Full textSimon, Marek. "Chromatin Modified! Dynamics, Mechanics, Structure, and HIV Integration." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1336752099.
Full textBolteau, Blandine. "La magnétisante histoire de la goutte fakir ou étude des propriétés de mouillage de surfaces superhydrophobes à géométrie magnétiquement modulable." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS062/document.
Full textDuring this thesis, we have developped superhydrophobic surfaces whose wettability can be controlled by an external magnetic stimulus. Formulating a network of elastomeric and magnetic micro-pillars with high aspect ratio allows the orientation of the pillars through magnetic forces, hence an adaptable surface roughness. Moreover, modulating the geometry, elasticity and magnetization of pillars allowed us to highlight the following conclusions.We have seen first that in agreement with the literature, without magnetic field, the wetting hysteresis increased with the surface fraction. However, it remains constant varying the elasticity of pillars. This conclusion is confusing, because at the pillar scale, there is indeed a difference of mobility between rigid and flexible pillars due to the force exerted by the triple line.We then demonstrated that the deflexion of the pillars can change significantly the sliding angle due to the applied magnetic field. Moreover, sliding of the droplet on such a surface is promoted when pillars are deflected against the slope.Finally, we managed to control the displacement of a droplet on a surface which is tilted with an angle below the sliding angle : it moves forward from the surface only if magnetic actuation is applied. This surfaces will be an attractive source of study in order to understand how to modulate wetting and liquid flow in fakir state
Mitchell, Stephanie Bianca. "Sediment Dispersal Processes and Anthropogenic Impacts at Rex Lake, Summit County, Ohio." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1442416877.
Full textPflug, Norbert. "Der historische Eisenerzbergbau im Osterzgebirge und Elbtalschiefergebirge – eine geographisch-geologische Landschaftsanalyse." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-126893.
Full textPflug, Norbert. "Der historische Eisenerzbergbau im Osterzgebirge und Elbtalschiefergebirge – eine geographisch-geologische Landschaftsanalyse." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-131472.
Full textGreen, Heather F. "Casting no shadow : overlapping soilscapes of European-Indigenous interaction in northern Sweden." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/13133.
Full textLin, Chih-Fang, and 林志芳. "An Action Research of Integrating Chinese Magnetism Technology History into the Teaching of Elementary School Science Curriculum." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99772169689739241621.
Full text國立臺中教育大學
科學應用與推廣學系科學教育碩士班
96
This study adopted the action research method to investigate how to integrate Chinese magnetism technology history into the teaching of elementary school science curriculum and further review the problems encountered, solving strategies, and professional growth of the researcher. The researcher first collected historical materials related to the Chinese magnetism and referred to the current concepts for the design of Science and Life Technology Curriculum to develop a teaching activity based on 「exploration of the myth of compass". The research subjects were 31 fifth-year students regularly distributed to a class and 2 groups of students (5 students in each group) in a mid-scale suburban elementary school in Changhua County. The 3.5-month experimental teaching was provided in the first and second semesters since Oct 2006. During the research process, data were collected from observation, interview, video-recording, and audio-recording, and further analyzed to modify, examine, and improve the designed teaching activity. Through the implementation, modification, and discussion of the teaching activity, the following results were obtained: 1. In the aspect of teaching design: The teaching design of technology history should be related to student’s interests and life experiences, and the content can be implemented and applied. According to student’s competence, the historical content can be modified into supplementary materials acceptable to students. 2. In the aspect of teaching implementation: When integrating technology history into teaching, it is necessary to adopt diverse teaching methods, so as to let students adequately engage into the exploration activities and increase their autonomous learning ability. Most of the students responded that they liked the teaching and felt they could acquire the knowledge about magnet and compassion and be benefited in the experiment. 3. In the aspect of teacher’s professional growth: The entire implementation process and presentation of the report were the source of the researcher’s growth. The researcher has gained improvement in the following aspects: knowledge about magnetism technology history, ability to compile computer programs, practical ability to teach technology history, and personal research ability. Finally, based on the research conclusions, some suggestions were proposed as a reference for practical applications and follow-up studies.
Ferrer, Marta. "Alternative Presence: the Cultural Meaning of Heterodox Sciences in Nineteenth-Century Spain." Thesis, 2021. https://doi.org/10.7916/d8-03ka-ga18.
Full textAudunsson, Haraldur. "Paleomagnetism, magnetic properties and thermal history of a thick transitional-polarity lava." Thesis, 1989. http://hdl.handle.net/1957/29359.
Full textGraduation date: 1990
Maré, Leonie Pauline. "Geothermal history of the Karoo Basin in South Africa inferred from magnetic studies." Thesis, 2015. http://hdl.handle.net/10210/13879.
Full textThe Karoo succession has economic significance through the exploitation of extensive coal deposits and in recent years has seen significant international interest due to potentially large shale gas resources. The thermal history of sedimentary basins affects the genesis of hydrocarbon deposits and it is therefore essential to model and reconstruct the geothermal variation across the Karoo Basin before evaluation of the hydrocarbon resources can take place. The main scientific questions related to the thermal history of the Karoo Basin are whether the emplacement of large volumes of magma was preceded by a large-scale lowgrade thermal doming as proposed for continental rift settings. Alternatively, was the Karoo thermal event restricted to the contact aureole of intrusives, as well as the question whether the intrusion of dolerite resulted in large-scale CO2 or CH4 degassing from coalbeds and carbonaceous shales based on similarities to other large igneous provinces? Magnetic techniques provide an alternative to more traditional methods to study the geothermal history of sedimentary basins (such as illite crystallinity and vitrinite reflectance), which are often associated with significant uncertainty. Three experiments using existing magnetic and palaeomagnetic methods were conducted to determine the peak temperatures reached by Karoo sedimentary rocks before and after the Karoo magmatic event. These experiments include the classic palaeomagnetic baked contact tests (magnetostratigraphy), analyses of the variation of magnetic susceptibility during repeated progressive heating (alteration index method) as well the variation of relative concentrations of fine grained pyrrhotite and magnetite in sedimentary strata relative to their distance from an intrusive (pyrrhotite/magnetite geothermometer). Additionally various magnetic fabric analyses were performed including a study of the variation in anisotropy of magnetic susceptibility (AMS). Although these techniques were successful in delineating the extent of the contact aureoles, only the alternating index (A40) had the ability to give estimated peak temperatures. Results indicate a general elevation of palaeotemperatures of the organic-rich sedimentary rocks of the Ecca Group to temperatures where hydrocarbons are normally converted into gas. Importantly, it is clear from this study that the greatest thermal effects of the sill intrusions on the sedimentary strata are limited to the contact aureoles, suggesting that there is an, as yet unquantified, potential for hydrocarbon resources remaining between these intrusions. A general increase in the palaeotemperatures from southwest to northeast across the basin was observed. This is mainly due to differences in thermal conductivity of the various lithologies across the basin from tight low porosity marine shales in the south and southwest towards more lacustrine mudstone and porous sandstone in the northeast.
Barrulas, Raquel Alexandra Valadares. "Treatment of paper biodeterioration by fungi: An NMR approach to the preservation of human history." Master's thesis, 2019. http://hdl.handle.net/10362/63791.
Full textGayler, Lucyna Maria. "A palaeoenvironmental history of the Paroo and Warrego Regions, Australia: a multi-proxy, multi-site approach." Thesis, 2008. http://hdl.handle.net/1959.13/33470.
Full textThe records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.
Gayler, Lucyna Maria. "A palaeoenvironmental history of the Paroo and Warrego Regions, Australia: a multi-proxy, multi-site approach." 2008. http://hdl.handle.net/1959.13/33470.
Full textThe records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.
Fushai, Felix. "Fermentability of dietary fibre and metabolic impacts of including high levels of fibrous feed ingedients in maize-soyabean growing pig diets supplemented with exogenous enzymes." Thesis, 2014. http://hdl.handle.net/10500/14220.
Full textEnvironmental Sciences
Ph.D. (Environmental Sciences)