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Thermalhydraulic behavior of electrically heated rod during a critical heat flux transient

Lima,Rita de Cássia Fernandes de; Carajilescov,Pedro
Fonte: The Brazilian Society of Mechanical Sciences Publicador: The Brazilian Society of Mechanical Sciences
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2000 EN
Relevância na Pesquisa
36.13%
In nuclear reactors, the occurrence of critical heat flux leads to fuel rod overheating with clad fusion and radioactive products leakage. To predict the effects of such phenomenon, experiments are performed using electrically heated rods to simulate operational and accidental conditions of nuclear fuel rods. In the present work, it is performed a theoretical analysis of the drying and rewetting front propagation during a critical heat flux experiment, starting with the application of an electrical power step from steady state condition. After the occurrence of critical heat flux, the drying front propagation is predicted. After a few seconds, a power cut is considered and the rewetting front behavior is analytically observed. Studies performed with various values of coolant mass flow rate show that this variable has more influence on the drying front velocity than on the rewetting one.

Evidence of neutron leakage at the Fukushima nuclear plant from measurements of radioactive 35S in California

Priyadarshi, Antra; Dominguez, Gerardo; Thiemens, Mark H.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.04%
A recent earthquake and the subsequent tsunami have extensively damaged the Fukushima nuclear power plant, releasing harmful radiation into the environment. Despite the obvious implication for human health and the surrounding ecology, there are no quantitative estimates of the neutron flux leakage during the weeks following the earthquake. Here, using measurements of radioactive 35S contained in sulfate aerosols and SO2 gas at a coastal site in La Jolla, California, we show that nearly 4 × 1011 neutrons per m2 leaked at the Fukushima nuclear power plant before March 20, 2011. A significantly higher activity as measured on March 28 is in accord with neutrons escaping the reactor core and being absorbed by the coolant seawater 35Cl to produce 35S by a (n, p) reaction. Once produced, 35S oxidizes to and and was then transported to Southern California due to the presence of strong prevailing westerly winds at this time. Based on a moving box model, we show that the observed activity enhancement in is compatible with long-range transport of the radiation plume from Fukushima. Our model predicts that , the concentration in the marine boundary layer at Fukushima, was approximately 2 × 105 atoms per m3, which is approximately 365 times above expected natural concentrations. These measurements and model calculations imply that approximately 0.7% of the total radioactive sulfate present at the marine boundary layer at Fukushima reached Southern California as a result of the trans-Pacific transport.

A Magnetic Flux Leakage and Magnetostrictive Guided Wave Hybrid Transducer for Detecting Bridge Cables

Xu, Jiang; Wu, Xinjun; Cheng, Cheng; Ben, Anran
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 05/01/2012 EN
Relevância na Pesquisa
46.49%
Condition assessment of cables has gained considerable attention for the bridge safety. A magnetic flux leakage and magnetostrictive guided wave hybrid transducer is provided to inspect bridge cables. The similarities and differences between the two methods are investigated. The hybrid transducer for bridge cables consists of an aluminum framework, climbing modules, embedded magnetizers and a ribbon coil. The static axial magnetic field provided by the magnetizers meets the needs of the magnetic flux leakage testing and the magnetostrictive guided wave testing. The magnetizers also provide the attraction for the climbing modules. In the magnetic flux leakage testing for the free length of cable, the coil induces the axial leakage magnetic field. In the magnetostrictive guided wave testing for the anchorage zone, the coil provides a pulse high power variational magnetic field for generating guided waves; the coil induces the magnetic field variation for receiving guided waves. The experimental results show that the transducer with the corresponding inspection system could be applied to detect the broken wires in the free length and in the anchorage zone of bridge cables.

Routes for GMR-Sensor Design in Non-Destructive Testing

Pelkner, Matthias; Neubauer, Andreas; Reimund, Verena; Kreutzbruck, Marc; Schütze, Andreas
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 05/09/2012 EN
Relevância na Pesquisa
26.34%
GMR sensors are widely used in many industrial segments such as information technology, automotive, automation and production, and safety applications. Each area requires an adaption of the sensor arrangement in terms of size adaption and alignment with respect to the field source involved. This paper deals with an analysis of geometric sensor parameters and the arrangement of GMR sensors providing a design roadmap for non-destructive testing (NDT) applications. For this purpose we use an analytical model simulating the magnetic flux leakage (MFL) distribution of surface breaking defects and investigate the flux leakage signal as a function of various sensor parameters. Our calculations show both the influence of sensor length and height and that when detecting the magnetic flux leakage of μm sized defects a gradiometer base line of 250 μm leads to a signal strength loss of less than 10% in comparison with a magnetometer response. To validate the simulation results we finally performed measurements with a GMR magnetometer sensor on a test plate with artificial μm-range cracks. The differences between simulation and measurement are below 6%. We report on the routes for a GMR gradiometer design as a basis for the fabrication of NDT-adapted sensor arrays. The results are also helpful for the use of GMR in other application when it comes to measure positions...

Defect Profile Estimation from Magnetic Flux Leakage Signal via Efficient Managing Particle Swarm Optimization

Han, Wenhua; Xu, Jun; Wang, Ping; Tian, Guiyun
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 12/06/2014 EN
Relevância na Pesquisa
46.17%
In this paper, efficient managing particle swarm optimization (EMPSO) for high dimension problem is proposed to estimate defect profile from magnetic flux leakage (MFL) signal. In the proposed EMPSO, in order to strengthen exchange of information among particles, particle pair model was built. For more efficient searching when facing different landscapes of problems, velocity updating scheme including three velocity updating models was also proposed. In addition, for more chances to search optimum solution out, automatic particle selection for re-initialization was implemented. The optimization results of six benchmark functions show EMPSO performs well when optimizing 100-D problems. The defect simulation results demonstrate that the inversing technique based on EMPSO outperforms the one based on self-learning particle swarm optimizer (SLPSO), and the estimated profiles are still close to the desired profiles with the presence of low noise in MFL signal. The results estimated from real MFL signal by EMPSO-based inversing technique also indicate that the algorithm is capable of providing an accurate solution of the defect profile with real signal. Both the simulation results and experiment results show the computing time of the EMPSO-based inversing technique is reduced by 20%–30% than that of the SLPSO-based inversing technique.

Fast Estimation of Defect Profiles from the Magnetic Flux Leakage Signal Based on a Multi-Power Affine Projection Algorithm

Han, Wenhua; Shen, Xiaohui; Xu, Jun; Wang, Ping; Tian, Guiyun; Wu, Zhengyang
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 04/09/2014 EN
Relevância na Pesquisa
46.17%
Magnetic flux leakage (MFL) inspection is one of the most important and sensitive nondestructive testing approaches. For online MFL inspection of a long-range railway track or oil pipeline, a fast and effective defect profile estimating method based on a multi-power affine projection algorithm (MAPA) is proposed, where the depth of a sampling point is related with not only the MFL signals before it, but also the ones after it, and all of the sampling points related to one point appear as serials or multi-power. Defect profile estimation has two steps: regulating a weight vector in an MAPA filter and estimating a defect profile with the MAPA filter. Both simulation and experimental data are used to test the performance of the proposed method. The results demonstrate that the proposed method exhibits high speed while maintaining the estimated profiles clearly close to the desired ones in a noisy environment, thereby meeting the demand of accurate online inspection.

An assessment of near surface CO2 leakage detection techniques under Australian conditions

Feitz, A.; Jenkins, C.; Schacht, U.; McGrath, A.; Berko, H.; Schroder, I.; Kuske, T.; Curnow, S.; George, S.; Heath, C.; Zegelin, S.; Zhang, H.; Sirault, X.; Jimenez-Berni, J.
Fonte: Elsevier Publicador: Elsevier
Tipo: Conference paper
Publicado em //2014 EN
Relevância na Pesquisa
36.04%
Geoscience Australia and the CO2CRC operate a greenhouse gas controlled release facility at an experimental agricultural station maintained by CSIRO Plant Industry in Canberra, Australia. The facility is designed to simulate surface emissions of CO2 and other greenhouse gases from the soil into the atmosphere. Over 10 different near surface monitoring techniques were trialled at the Ginninderra controlled release site during 2012-2013. These included soil gas, soil CO2 flux, soil analysis, eddy covariance, CO2 laser, noble gas tracers, airborne hyperspectral, in-field phenotyping (thermal, hyperspectral and 3D imaging), and microbial soil genomics. Result highlights are presented. Different climatic conditions for the early 2012 release experiment (wet) and late 2013 release experiment (dry) resulted in markedly different sub-surface plume behaviour and surface expression of CO2. The differences between the years are attributed to changes in groundwater levels and drier conditions leading to a larger vadose zone during the 2013 experiment.; Andrew Feitz, Charles Jenkins, Ulrike Schacht, Andrew McGrath, Henry Berko, Ivan Schroder, Ryan Noble, Tehani Kuske, Suman George, Charles Heath, Steve Zegelin, Steve Curnow, Hui Zhang, Xavier Sirault Jose Jimenez-Berni...

Magnetic flux leakage sensing: The forward and inverse problems

Dutta, Sushant M.
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
46.17%
Nondestructive evaluation (NDE) is the inspection of samples for corrosion and physical defects without altering them in any way. NDE has a critical role in the robotic inspection of energy pipelines in order to prevent catastrophic failures. Magnetic flux leakage (MFL) sensing is by far the most effective technique for robotic inspection of ferromagnetic pipes and tubular specimens. Defect detection using MFL sensing is a mature area of work, but defect characterization using MFL sensing is an open research problem. Several issues involved in this process are not well understood---for example, the interplay of the components of the 3-dimensional MFL field for 3-dimensional defects, the spatial properties of the MFL field components, the effect of sensor lift-off on MFL signals, and the relationships between defect properties and MFL signal properties. This dissertation addresses these issues using a systematic approach. First the MFL sensing problem is decomposed into the forward and inverse problems. Subsequently, a tractable forward model is presented which is capable of predicting the 3-dimensional MFL field of a known 3-dimensional surface-breaking defect. Important properties of the MFL field and their correlation with sensing parameters and defect parameters are established using the model and simulation. A linear inversion technique is presented which exploits the structure and properties of the forward model to characterize defects based on measured MFL signals. This dissertation also proposes a general framework to solve the inverse problem independent of the NDE modality in use. This framework uses the principles of data fusion and neural networks...

Measurement of pipe wall thickness using magnetic flux leakage signals

Dutta, Sushant Madhukul; Ghorbel, Fathi Hassan
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
46.17%
An apparatus comprising a processor configured to implement a method comprising obtaining a pipe profile comprising a diameter, a nominal thickness, and a material, receiving a magnetic flux leakage (MFL) indication for a pipe associated with the pipe profile, and determining a wall thickness for the pipe using the pipe profile and the MFL indication. Also disclosed is a method comprising modeling an apparatus comprising a magnet configured to induce a magnetic field in a pipe, and determining a wall thickness measurement (WTM) for the pipe using a model of the apparatus and the pipe, a detected MFL signal, and a simulated MFL signal.

Modeling and Interpretation Magnetic Flux Leakage

Trevino Garcia, David A.
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text Formato: 99 p.; application/pdf
ENG
Relevância na Pesquisa
46.17%
This work presents an analysis of Magnetic Flux Leakage (MFL) signal to better understand the forward problem and the physics contributing to the nature of the signals. The analysis of the MFL signal was done through the implementation of two mathematical models such as the Magnetic Dipole Model (MDM) and Finite Element Method (FEM). This thesis shows that MFL signals presents a similar behavior even if the defect's characteristics differ (length, shape and depth). Also, this thesis introduces a Wavelet Analysis (WA) as a tool for further characterization of the MFL signal. This study presents how WA can identify and expose specific characteristics of each defect's MFL signal, even though the signals of different defect shapes were very similar to each other. The main advantage of this work is that it can achieve without changing the current MFL technique, additional information of the defect can be extracted.

Understanding Magnetic Flux Leakage from Gouges and Dents Containing Gouges

CHEN, JIA DIAN
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
46.17%
Magnetic flux leakage (MFL) is the most widely used non-destructive evaluation (NDE) technique for operating gas and oil transmission pipelines. The Queen’s Applied Magnetics Group (AMG) has been studying MFL signals from dents for the past 5 years, and recently began considering MFL signals from gouges, and gouge/dent combinations. It is believed that MFL signals from gouges may arise from three factors: the gouge geometry, residual stresses, and a severe plastically deformed layer that is often present at the base of the gouge. The last factor has been studied by another MSc student, Kris Marble. The present thesis work primarily considers the effects of the first two factors – gouge geometry in combination with residual stress. Samples containing realistic gouges, produced under field-like conditions, were obtained from two sources - Stress Engineering Services (SES) in Houston, Texas and GdF Suez in St. Denis, France. At SES, ten different gouges on five pipes (two on each pipe) with increasing severity were produced for the current thesis project. Three gouged pipe samples were obtained from GdF Suez. The bulk of the thesis study involved experimental MFL measurements made for each of the gouges and gouge/dents of SES samples in the study...

Invesigation of the Magnetic Flux Leakage Signatures of Dents and Gouges

Marble, KRISTOPHER
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado Formato: 12964838 bytes; application/pdf
EN; EN
Relevância na Pesquisa
66.34%
A study of gouges and dents in the context of pipelines has been completed, using the non-destructive evaluation (NDE) techniques of magnetic flux leakage (MFL) and magnetic Barkhausen noise (MBN). The research is part of an ongoing effort by the Applied Magnetics Group (AMG) at Queen's University to improve the interpretation of the MFL signal, which is used extensively by industry for defect detection and evaluation. The gouges were found to have distinctive MFL signatures depending on their orientation relative to the magnetization axis. Features in the MFL signal were identified as superpositions of geometry-related effects and strain or work hardening of the surface material. A qualitative magnetic permeability distribution in the material near a gouge has been proposed. The distribution is expected to vary in magnitude and extent according to the defect severity. The MFL results of the dent studies, on samples made available by Gaz de France (GdF), largely agreed qualitatively with previous research of dents. However, the differences pointed to the need for study of more varied dent shapes; new signal features were observed that suggested tensile residual strain in the dent rim is more prominent than earlier studies and modeling have predicted. Additionally...

A Magnetic Flux Leakage NDE System for CANDU Feeder Pipes

Mak, Thomas
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
46.24%
This work examines the application of different magnetic flux leakage (MFL) inspection concepts to the non destructive evaluation (NDE) of residual (elastic) stresses in CANDU reactor feeder pipes. The stress sensitivity of three MFL inspection techniques was examined with flat plate samples, with stress-induced magnetic anisotropy (SMA) demonstrating the greatest stress sensitivity. A prototype SMA testing system was developed to apply magnetic NDE to feeders. The system consists of a flux controller that incorporates feedback from a wire coil and a Hall sensor (FCV2), and a magnetic anisotropy prototype (MAP) probe. The combination of FCV2 and the MAP probe was shown to provide SMA measurements on feeder pipe samples and predict stresses from SMA measurements with a mean accuracy of ±38MPa.; Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-03-11 15:59:23.978

Medida do buckling e da probabilidade de fuga de nêutrons do núcleo do reator IPEN/MB-01; Determination of buckling and probability of leakage of neutron in the IPEN/MB-01 reactor in cylindrical configuration

Purgato, Rafael Turrini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/09/2014 PT
Relevância na Pesquisa
36.27%
Um dos parâmetros fundamentais da física de reatores é a curvatura do fluxo de nêutrons (Buckling) do núcleo do reator. Ele está relacionado com outros parâmetros importantes, tais como as taxas de reação, potencia de operação, queima de combustível, entre outros. Num reator crítico, o Buckling depende das características geométricas e de material do núcleo do reator. Este trabalho apresenta os resultados do Buckling experimental para o reator nuclear IPEN/MB-01 em sua configuração cilíndrica com 28 barras de combustível ao longo de seu diâmetro. O IPEN/MB-01 é um reator de potência zero projetado para operar em uma potência máxima nominal de 100 watts. É uma instalação nuclear versátil que permite a simulação de todas as características de um grande reator nuclear e ideal para este tipo de medição. Foi realizado um mapeamento do fluxo de nêutrons no interior do reator e, assim, determinado o Buckling total da configuração cilíndrica. O reator foi operado durante uma hora para cada experimento. Em seguida, a taxa de reação nuclear das varetas de combustível foram medidas por espectrometria gama em um detector de germânio hiper-puro (HPGe) que escaneou as varetas axial e radialmente. Foram analisados os fótons gama do 239Np ( 276...

Intrinsic leakage of the Josephson flux qubit and breakdown of the two-level approximation for strong driving

Ferron, Alejandro; Dominguez, Daniel
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.54%
Solid state devices for quantum bit computation (qubits) are not perfect isolated two-level systems, since additional higher energy levels always exist. One example is the Josephson flux qubit, which consists on a mesoscopic SQUID loop with three Josephson junctions operated at or near a magnetic flux of half quantum. We study intrinsic leakage effects, i.e., direct transitions from the allowed qubit states to higher excited states of the system during the application of pulses for quantum computation operations. The system is started in the ground state and rf- magnetic field pulses are applied at the qubit resonant frequency with pulse intensity $f_p$. A perturbative calculation of the average leakage for small $f_p$ is performed for this case, obtaining that the leakage is quadratic in $f_p$, and that it depends mainly on the matrix elements of the supercurrent. Numerical simulations of the time dependent Schr\"odinger equation corresponding to the full Hamiltonian of this device were also performed. From the simulations we obtain the value of $f_p$ above which the two-level approximation breaks down, and we estimate the maximum Rabi frequency that can be achieved. We study the leakage as a function of the ratio $\alpha$ among the Josephson energies of the junctions of the device...

Influence of specimen velocity on the leakage signal in magnetic flux leakage type nondestructive testing

Zhang, Lintao; Belblidia, Fawzi; Cameron, Ian; Sienz, Johann; Boat, Matthew; Pearson, Neil
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/12/2014
Relevância na Pesquisa
46.27%
We investigate the influence of the specimen velocity on the magnetic flux leakage with the aim of selecting the optimum sensor locations. Parametric numerical simulations where the specimen velocity was in the range [0.1-20] m$\cdot$s$^{-1}$ were carried out. As the specimen velocity is increased, the magnetic field varies from being symmetrical to being asymmetric. For the radial magnetic induction, the peak to peak value moves from the centre of the bridge towards the direction of the specimen movement. For the axial magnetic induction, the specimen velocity influence is dependent on the sensor location and a signal-velocity independent region was discussed.

Magnetic Flux Leakage Method: Large-Scale Approximation

Pimenova, Anastasiya V.; Goldobin, Denis S.; Levesley, Jeremy; Ivantsov, Andrey O.; Elkington, Peter; Bacciarelli, Mark
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/01/2015
Relevância na Pesquisa
46.17%
We consider the application of the magnetic flux leakage (MFL) method to the detection of defects in ferromagnetic (steel) tubulars. The problem setup corresponds to the cases where the distance from the casing and the point where the magnetic field is measured is small compared to the curvature radius of the undamaged casing and the scale of inhomogeneity of the magnetic field in the defect-free case. Mathematically this corresponds to the planar ferromagnetic layer in a uniform magnetic field oriented along this layer. Defects in the layer surface result in a strong deformation of the magnetic field, which provides opportunities for the reconstruction of the surface profile from measurements of the magnetic field. We deal with large-scale defects whose depth is small compared to their longitudinal sizes---these being typical of corrosive damage. Within the framework of large-scale approximation, analytical relations between the casing thickness profile and the measured magnetic field can be derived.; Comment: 12 pages, 3 figures

Noise-Produced Patterns in Images Constructed from Magnetic Flux Leakage Data

Pimenova, Anastasiya V.; Goldobin, Denis S.; Levesley, Jeremy; Elkington, Peter; Bacciarelli, Mark
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/01/2015
Relevância na Pesquisa
46.34%
Magnetic flux leakage measurements help identify the position, size and shape of corrosion-related defects in steel casings used to protect boreholes drilled into oil and gas reservoirs. Images constructed from magnetic flux leakage data contain patterns related to noise inherent in the method. We investigate the patterns and their scaling properties for the case of delta-correlated input noise, and consider the implications for the method's ability to resolve defects. The analytical evaluation of the noise-produced patterns is made possible by model reduction facilitated by large-scale approximation. With appropriate modification, the approach can be employed to analyze noise-produced patterns in other situations where the data of interest are not measured directly, but are related to the measured data by a complex linear transform involving integrations with respect to spatial coordinates.; Comment: 11 pages, 2 figures

Numerical simulation of leakage effect for quantum NOT operation on three-Josephson-junction flux qubit

Wu, Tao; Liu, Jianshe; Li, Zheng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.39%
Superconducting flux qubits with three Josephson junctions are promising candidates for the building blocks of a quantum computer. We have applied the imaginary time evolution method to study the model of this qubit accurately by calculating its wave functions and eigenenergies. Because such qubits are manipulated with magnetic flux microwave pulses they might be irradiated into non-computational states which is called the leakage effect. Through the evolution of the density matrix of the qubit under either hard-shaped pulse or Gaussian-shaped pulse to carry out quantum NOT operation, we show that the leakage effect is not a serious problem for a flux qubit.; Comment: 6pages, 3figures; accepted by Chinese Physics Letters

Surface and deep circulation off South Africa Agulhas leakage influence on the meridional overturning circulation during the last 345 kyr /

Martínez Méndez, Gema
Fonte: Bellaterra: Universitat Autònoma de Barcelona, Publicador: Bellaterra: Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis Formato: application/pdf
Publicado em //2010 SPA; SPA
Relevância na Pesquisa
26.33%
Descripció del recurs: el 11 d'agost de 2010; Investigaciones paleocenográficas y simulaciones numéricas están mostrando que el Hemisferio Sur desempeña un papel importante, tanto en los cambios de la circulación global como en la definición del estado climático terrestre. Una región clave para la circulación global se encuentra en la región alrededor de Sudáfrica. Aquí, aguas superficiales y de termoclina del Océano Índico son transferidas al Atlántico a través de anillos y de filamentos de la Corriente de Agulhas. En profundidad, la transferencia de agua se produce en la dirección opuesta, con Agua Profunda del Atlántico Norte (North Atlantic Deep Water, NADW), abandonando la cuenca atlántica y entrando en la índica. La entrada de aguas cálidas y saladas de Agulhas al Atlántico Sur se cree que puede influir en el Atlántico Norte a través de perturbaciones en los balances de flotabilidad, siendo crucial para el modo y estabilidad de la Circulación Meridional Atlántica (Meridional Overturning Circulation, MOC). En esta Tesis presento registros de 345.000 años de isótopos estables de foraminíferos planctónicos y bentónicos, Cd/Ca de bentónicos, Mg/Ca de planctónicos, granoclasificación de arcillas (sortable silt) y censos de foraminíferos de un registro combinado de dos testigos sedimentarios recuperados a profundidades medias (~ 2500 m) aguas adentro de Sudáfrica. Los registros permiten discernir la circulación superficial y profunda pasada y evaluar la conexión entre el flujo superficial de aguas índicas hacia el Atlántico y el flujo de aguas profundas atlánticas hacia el Índico. La circulación profunda del Atlántico se cree que era diferente durante el Último Máximo Glacial (Last Glacial Maximum...