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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.
271

The Potential of Hyperspectral Imaging to Detect Tree Species and Evaluate Their Condition / Hiperspektrinio skenavimo galimybės miško medžių rūšims atpažinti ir jų būklei įvertinti

Masaitis, Gediminas 18 December 2013 (has links)
For the first time in Lithuania the foliage spectral reflectance properties of common tree species were investigated using hyperspectral imaging. The methodological outline was formulated and the procedures of practical hyperspectral imaging application were developed to stimulate the progress of hyperspectral remote sensing in Lithuanian forestry. Information extracted from foliage hyperspectral reflectance data was used to accurately determine forest tree species and the provenances of Scots Pine trees. The satisfactory results of determination of Scots Pine crown defoliation and the concentration of some needles chemical constituents were achieved investigating the foliar hyperspectral reflectance, too. The first spectral libraries of common Lithuanian tree species foliar reflectance were built considering the growing season. / Suformuoti hiperspektrinio skenavimo naudojimo įvairioms miško medžių savybėms tirti metodiniai ir praktiniai pagrindai – sukurtos ir išbandytos mėginių paėmimo, jų paruošimo skenuoti, skenavimo atlikimo ir gautos informacijos apdorojimo metodikos, kurios aprobuotos vykdant mokslinius tyrimus. Nustatyti vegetacijos sezono momentai, kuriais skirtingų miško medžių rūšių atpažinimas nuotoliniu būdu pagal jų spektrinus atspindžius būtų tiksliausias, o tai sudaro prielaidas tobulinti kitas nuotoliniais. Pasiūlyti metodai paprastosios pušies spyglių kai kurių cheminių elementų koncentracijai nustatyti naudojant hiperspektrinį skenavimą. Sukurtos Lietuvos miškuose augančių pagrindinių medžių rūšių lapijos spektrinio atspindžio kreivių bibliotekos, naudotinos miškų inventorizacijoje, kalibruoti ir klasifikuoti orlaiviuose sumontuotais jutikliais išgautus Lietuvos medynų hiperspektrinius vaizdus.
272

Political attitudes in the Sudanese diaspora and the influence of region of origin

Baird, Stephen 04 1900 (has links) (PDF)
Les attitudes politiques des membres des diasporas ont été peu étudiées à ce jour; ce constat s'applique tout particulièrement à la diaspora soudanaise (connue avant 2011 en tant que diaspora « nord-soudanaise »). Ce mémoire présente un portrait des perceptions de la diaspora soudanaise au Canada en lien avec les conflits armés au Soudan, l'implication du gouvernement soudanais et des pays occidentaux, de même que la démocratisation du pays, réelle et envisagée. Le mémoire analyse également les liens entre la région d'origine des membres de la diaspora et les opinions politiques, posant l'hypothèse que l'affiliation régionale est un point d'ancrage important pour un clivage attitudinal. L'hypothèse est testée grâce à des données d'entrevues recueillies auprès de quinze membres de la diaspora soudanaise au Canada à l'automne 2011 et à l'hiver 2012. Les résultats confirment que l'origine régionale, définie en termes de territoires marginalisés et non-marginalisés, est associée aux attitudes à l'égard des conflits au Soudan et de certains des acteurs qui y sont impliqués. La plupart de ceux qui proviennent de régions marginalisées croient qu'un génocide a eu lieu au Darfour. Ils sont aussi plus nombreux à soutenir une intervention étrangère au Soudan sous une forme ou une autre en 2011-2012. Ceux qui proviennent de régions non-marginalisées rejettent pour leur part la notion de génocide et sont généralement opposés à une intervention extérieure. La région d'origine est également liée à la vision du changement politique au Soudan. La majorité des répondants originaires de territoires non-marginalisés invoquent la possibilité d'un soulèvement populaire menant à une transition démocratique; certains mettent l'accent sur le rôle de la société civile soudanaise dans un éventuel changement de régime, par opposition à toute intervention extérieure. Au contraire, les interviewés de régions marginalisés envisagent une intervention étrangère comme un instrument d'un éventuel changement et ne font pas mention de la société civile. Les opinions recueillies ne sont pas toujours distinctes en fonction de la région d'origine. C'est le cas des perceptions (négatives) à l'égard du rôle du gouvernement du Soudan dans les récents conflits et élections. La nature de l'échantillon colore incontestablement ces perceptions; en effet, la plupart des Soudanais vivant au Canada s'y sont réfugiés pour fuir la répression; il s'agit également d'individus particulièrement informés et engagés politiquement. En dépit de cette limite, cette étude nous permet de jeter un éclairage inédit sur les attitudes des Soudanais au Canada. Elle montre également qu'il est fructueux de mettre en œuvre le concept de clivage dans un contexte de diaspora, notamment lorsqu'elle est issue d'une immigration récente. Enfin, ses résultats vont dans le sens des études qui remettent en cause l'ethnicité comme principal, voire l'unique facteur pouvant expliquer les attitudes politiques des Africains. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Soudan, diaspora, attitudes politiques, opinions politiques, clivages
273

Bibliotheken in der NS-Zeit

Alker, Stefan, Köstner, Christina, Stumpf, Markus 15 September 2014 (has links) (PDF)
Im vorliegenden Band sind die Beiträge der vom 25. bis zum 27. März 2008 in Wien stattgefundenen Tagung Bibliotheken in der NS-Zeit – Provenienzforschung und Bibliotheksgeschichte zusammengefasst. Die Universität Wien und das Wiener Rathaus bildeten einen würdigen und ansprechenden Rahmen für die Vorträge und Diskussionen. Der Band folgt dabei in seiner Struktur den Panels der Tagung mit ihren eng miteinander verwobenen Themenschwerpunkten: Provenienzforschung, Bibliotheken in der NS-Zeit, Wien und Bücherraub in den besetzten Gebieten.
274

Spurensuche

Kocourek, Jana, Köhler, Norman 15 July 2010 (has links) (PDF)
Provenienzforschung ist heute ein gern und oft gebrauchtes Schlagwort in Bibliotheken. Bund und Länder haben in Magdeburg eine zentrale Einrichtung zur Provenienzrecherche im deutschsprachigen Raum eingerichtet. Mit der Lost-Art-Internetdatenbank ist die weltweite Recherche nach Kunstwerken und Büchern und ihren Verlustumständen möglich. Die entsprechenden Objekte können zweifelsfrei identifiziert werden und dem rechtmäßigen Eigentümer zurück erstattet werden. Im April 2009 startete an der SLUB Dresden ein Projekt zur Provenienzerschließung. Bis Ende April 2010 sind knapp 74.000 Exemplare mit ca. 128.000 Provenienzen erfasst worden.
275

’Source to sink’ sedimentology and petrology of a dryland fluvial system, and implications for reservoir quality, Lake Eyre Basin, Central Australia.

Menacherry, Saju January 2008 (has links)
Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008
276

Provenance establishment and authentication of South-East Asian ceramics using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

Bartle, Emma Kathleen January 2009 (has links)
[Truncated abstract] The sale of fraudulent South-East Asian ceramics constitutes a large proportion of the illegal artefact and antique trade and threatens to undermine the legitimate international market. The sophistication and skill of forgers has reached a level where, using traditional appraisal by eye and hand, even the most experienced specialist is often unable to distinguish between a genuine and fraudulent piece. In addition, the current scientific method of authentication used by the international antiques and art industry, thermoluminescence (TL) dating, carries severe limitations. The technique has an error margin of +/-20 % and requires the removal of a significant piece of the sample being tested, which decreases both the monetary and cultural value of the artefact. Of more concern, forgers have developed methods which produce false test results and which appear to corroborate false claims for the age of artefacts. Consequently, the use of TL dating for authentication of ancient ceramics, especially those of South-East Asian origin, has now come into serious question. The most suitable method for authenticating ceramics is through provenance establishment. Studies published in the literature have investigated the application of various analytical techniques to provide this information for ceramic wares and have highlighted their potential to be used for provenance establishment. However, the value of each of these techniques is limited rendering them generally unsuitable for practical use in the international antiques and art world to authenticate high-value South-East Asian artefacts. Consequently, there is a desperate need for the development of a robust, accurate and non-destructive method which can be practically applied in the industry to authenticate South-East Asian ceramics. ... Minor variations between spectral profiles of artefacts produced in the same country have also been used to further provenance artefacts to a specific production region or kiln site. The results of analyses have been compiled to form a unique reference database which can be added to in the future and used by experts internationally. Adaptation of the developed sampling and analytical methodologies to allow in-situ sampling of large artefacts using the
277

’Source to sink’ sedimentology and petrology of a dryland fluvial system, and implications for reservoir quality, Lake Eyre Basin, Central Australia.

Menacherry, Saju January 2008 (has links)
Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008
278

’Source to sink’ sedimentology and petrology of a dryland fluvial system, and implications for reservoir quality, Lake Eyre Basin, Central Australia.

Menacherry, Saju January 2008 (has links)
Reservoir quality of subsurface sandstones depends on the composition, texture and grain size of the initial sediments. These factors are a function of hinterland processes: tectonic setting, provenance, climate and depositional environment, and sediment transportation processes. This study focuses on a modern, dryland, fluvial deposition system from source-to-sink that aims to provide a quantitative dataset analogue to facilitate forward modelling for prediction of subsurface compositions, grain size and textures of reservoir sandstones. Umbum Creek, in the western Lake Eyre Basin of Central Australia, was selected as a small river network (~ 100km²) in order to study source-to-sink sedimentation. The provenance area was analysed using isopach maps derived from a 783 drill-hole dataset, which included stratigraphy and lithology information. Subsequently forty-three samples of different provenance lithotypes from the Umbum Creek catchment were collected for petrographic thin-section analysis. Recent sediments were then sampled from 90 strategically located stream confluences along Umbum Creek and tributaries (proximal, medial and distal subsets). A quantitative textural and compositional dataset was subsequently generated from 34 selected samples. With half-phi sieve analysis (4mm to 32 microns), and an associated petrographic description recognising 72 categories of grain composition was undertaken for each sample. The provenance analysis using isopach maps demonstrated that Palaeozoic and Mesozoic sedimentary basin evolution in the study area was controlled by northeast and northwest-trending structural elements. The regional uplift of the Peake and Denison Inliers that occurred during the Cenozoic had a significant impact on the evolution of the Lake Eyre Basin, causing changes in the provenance of Late Neogene sedimentation and on through to the present. The sink area represents a shallow intracratonic basin whereby a thin veneer of fluvial/lacustrine sediments is accumulating adjacent to a basement uplift. This study has highlighted the importance of multiple sediment provenances. Five different provenance lithotype grains were identified in the Umbum Creek modern sediments: the Gawler Craton plutonic / basement provenance (recycled) the Peake and Denison Inliers Proterozoic volcanic provenance (recycled), the Davenport Ranges metamorphic provenance, the Mesozoic sedimentary provenance and the Cenozoic sedimentary provenance. Whereas a downstream fining of grain size was expected, a general trend of downstream coarsening of grain size was noted being the result of aeolian deflation of fines and intra-basinal coarse-grained sediment contributions. In the sink area, modern sediments from the terminal splay complex comprise 70-80% quartz, 10-20% lithic fragments (of which ~ 7% are ductile lithic grains), < 3% feldspar, and clay (<2%). Grains are sub-angular to well-rounded and moderately well sorted. The compositional and textural maturity of the terminal splay sediments is attributed to reworked plutonic quartz grains, the dissolution and disintegration of feldspar and carbonate grains during transportation, along with the breakdown of lithic fragments due to fluvio-aeolian interactions and subsequent mechanical/ chemical weathering processes. These data were used to build a predictive forward model for modal sandstone analysis that achieved a fair to good correlation between predicted and observed grain lithotypes and provenance categories. These results illustrate that the character of sands in the Umbum Creek catchment are governed by a multiplicity of controls such as tectonic setting, provenance lithotype analysis, climate, regional topographic gradient, hinterland transport distance, basin subsidence rate and depositional environment. The fluvio-aeolian depositional environment along with the current arid to semi-arid playa climatic conditions of Umbum Creek catchment facilitate the growth of clay coatings, however accounts for a low clay matrix within the deposits. In addition, the playa environment also facilitates the alteration of infiltrated detrital clay to kaolinite, the formation of evaporites (gypsum, halite and anhydrite) and the formation of authigenic clays. These factors are all significant in determining the ultimate reservoir quality of reservoir sandstones, emphasising the importance of this study as an analogue for modelling ‘buried’ dryland depositional systems. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337211 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2008
279

Integrace a konzumace důvěryhodných Linked Data / Towards Trustworthy Linked Data Integration and Consumption

Knap, Tomáš January 2013 (has links)
Title: Towards Trustworthy Linked Data Integration and Consumption Author: RNDr. Tomáš Knap Department: Department of Software Engineering Supervisor: RNDr. Irena Holubová, PhD., Department of Software Engineering Abstract: We are now finally at a point when datasets based upon open standards are being published on an increasing basis by a variety of Web communities, governmental initiatives, and various companies. Linked Data offers information consumers a level of information integration and aggregation agility that has up to now not been possible. Consumers can now "mashup" and readily integrate information for use in a myriad of alternative end uses. Indiscriminate addition of information can, however, come with inherent problems, such as the provision of poor quality, inaccurate, irrelevant or fraudulent information. All will come with associated costs of the consumed data which will negatively affect data consumer's benefit and Linked Data applications usage and uptake. In this thesis, we address these issues by proposing ODCleanStore, a Linked Da- ta management and querying tool able to provide data consumers with Linked Data, which is cleansed, properly linked, integrated, and trustworthy accord- ing to consumer's subjective requirements. Trustworthiness of data means that the data has associated...
280

Is?topos de Nd na proveni?ncia de rochas e sedimentos da Bacia Potiguar, NE do Brasil

Maruoka, Miriam Tyoka da Silva 04 May 2007 (has links)
Made available in DSpace on 2015-03-13T17:08:28Z (GMT). No. of bitstreams: 1 MiriamTSM_DISSERT.pdf: 746109 bytes, checksum: 9993efc70026d11b86a511c7cf5aa9bc (MD5) Previous issue date: 2007-05-04 / Nd ISOTOPES IN THE PROVENANCE OF TERRIGENOUS AND CARBONATE ROCKS AND SEDIMENTS OF THE POTIGUAR BASIN, NORTHEASTERN BRAZIL. Mesozoic and Cenozoic rocks from the Potiguar Basin, including terrigenous and carbonate sediments have been investigated to identify their isotopic signature and source areas. Additionally, this study aims to determine the provenance of terrigenous and carbonate sediments on the Brazilian Continental shelf adjacent to Potiguar Basin. The Sm-Nd isotopic signatures of the rocks yielded model ages (TDM) in the range of 2,19- 2,88 Ga, indicating archean to paleoproterozoic sources from the basement. The terrigenous sediments yielded model ages (TDM) in the range of 2,31-2,26 Ga, from 17,5 to 0 cm depth. Despite the small number of samples, limited variations of provenance ages indicates the homogenization of the sediments, probably due to the strong influence of the basement, as the main source of sediments to the shelf. The Sm-Nd isotopic signatures of the carbonate sediments yielded model ages (TDM) in the range of 2,09-2,61 Ga, indicating archean to paleoproterozoic sources from the basement. The results also indicate that the shelf sediments are mainly derived from the A?u River or other small rivers from the Setentrional Sector of Rio Grande do Norte State. The littoral drift doesn?t seem to contribute with sediments from the Oriental Sector since isotopic signatures from this sector were not detected. / An?lises isot?picas Sm-Nd em rochas mesoz?icas e cenoz?icas da Bacia Potiguar, incluindo sedimentos terr?genos e carbon?ticos que aportam do Rio Piranhas-A?u, foram realizadas objetivando a caracteriza??o de suas assinaturas isot?picas e identifica??o de suas ?reas fonte. As assinaturas isot?picas Sm-Nd das rochas apresentaram idades modelo (TDM) variando de 2,88 a 2,19 Ga, indicando fontes, principalmente, paleoproteroz?icas e arquenas do embasamento. Os sedimentos terr?genos plataformais apresentaram idades modelo (TDM) de 2,31 Ga e 2,26 Ga, coletados, respectivamente, nas profundidades de 10-17,5 cm e 0-5 cm. Apesar do n?mero pequeno de amostras, a pequena varia??o na idade indica homogeneiza??o dos sedimentos, talvez devido a forte influ?ncia do embasamento como fonte de material para a plataforma. As assinaturas isot?picas Sm-Nd dos sedimentos carbon?ticos plataformais apresentaram idades modelo (TDM) variando de 2,61 a 2,09 Ga, indicando fontes do embasamento arqueano a paleoproteroz?ico. Estes resultados indicam ainda que os sedimentos terr?genos presentes na plataforma em estudo s?o ou foram trazidos principalmente pelo rio A?u, ou outros rios menores da por??o setentrional do Rio Grande do Norte. A deriva litor?nea aparentemente n?o tem compet?ncia para arrastar sedimentos da por??o oriental para a setentrional, tendo em vista que os valores ?Nd registrados n?o s?o compat?veis com as rochas da por??o oriental.

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