Sedimentology on two cores from Scoresby Sund, Greenland

Reconstruction of the postglacial palaeoenvironmental evolution was the main objective of marine geological investigations in the Scorcsby Sund fjord system. For this purpose, samples of marine sediments, taken on RV Polarstern cruises ARK-V/3b and ARK-VII/3b in 1988 and 1990, have been analysed. All investigated fjord sediments are paratills. However, remarkable changes in sediment fabric and composition occur with depth in cores. They are attributable to different modes of sediment deposition. Therefore, a subdivision of the postglacial palaeoenvironmental history into periods of considerably different sedimentary conditions is feasible. The change of sedimentary fades with time is interpreted by deposition under changing climatic conditions during the postglacial. Displacements of cyclonic and anticyclonic centers in the atmosphere change amount of precipitation at the east coast of Greenland. Precipitation strongly influences extension of local ice caps of coastal areas and duration of coverage of the fjords by sea ice. These factors again control the sedimentary regime in the fjord system.

Aglomeração urbana descontínua: o exemplo de Araguari e Uberlândia/MG

The analysis of urban conurbations demands the understanding regarding the difference between urban territorial continuity and spatial continuity. While the spatial continuity is understood due to its interrelations and established fluxes, in other words, through the spatial integration, the territorial continuity is related to the urban tissue. Therefore, the spatial continuity can manifest in a simultaneous way or associated to the territorial discontinuity. From this perspective, the main objective of this research consists on identifying and dimensioning the spatial interactions that are driven to a urban conurbation process between the municipalities of Araguari and Uberlândia/MG, besides the not continuity of the territorial urban area. The intensity of these interactions was identified from the displacements by the dwellers from both municipalities in search of job occupations, education and health assistance. So it would be able to reach the proposed objectives we used several methodological procedures, such as a bibliographic and documental researches. In order to identify the education and work fluxes we analyzed the micro data from the Demographic Census 2010. For the educational sector it was also accomplished a research, in Araguari, the place of residence of students enrolled at Instituto Master de Ensino Presidente Antônio Carlos (IMEPAC) and, in Uberlândia, the place of residence of students enrolled at Universidade Federal de Uberlândia (UFU). The identification of health fluxes was done through a research, in Uberlândia, of the inpatients' origin at Hospital de Clínicas de Uberlândia of the Universidade Federal de Uberlândia (HCU/UFU) and, in Araguari, of the origin of patients that are attended at the Pronto-Socorro Municipal. Semi structured interviews were also accomplished with different social actors. Another important step was the use of questionnaires with the inter-municipal public transportation users at their boarding place in Araguari and Uberlândia. This paper was organized in five chapters, while in the first one we accomplished a theoretical discussion over the concept of urban conurbation, in order to presenting the identification and classification criteria and the urban conurbation of non metropolitan criteria. The second chapter analyses the differentiation process between Araguari and Uberlândia, which is a result of the distinct territorial formation of the municipalities. The third chapter analyses the intensity and degree of the spatial interactions between the two municipalities, having as a focus the established fluxes in the work sector. The fourth chapter, on the other hand, focuses on the education and health sectors, while the last chapter accomplishes a discussion to investigate if the analyzed fluxes in the previous chapters make it able to identify if the spatial interactions established between Araguari and Uberlândia are measured through complementarities or dependence. As a result it was possible to identify that, due to the expressiveness of the established fluxes between the two municipalities, beyond the further ones of Triângulo Mineiro and Alto Paranaíba in the three selected sectors, there is a configuration of a discontinuous urban conurbation process. It was also possible to conclude that, despite the fluxes between Araguari and Uberlândia being more representative than the other way around there's a coexistence dependence relationship and complementarity between the two municipalities.

Haematite natural crystals: non-linear initial susceptibility at low temperature

Several works have reported that haematite has non-linear initial susceptibility at room temperature, like pyrrhotite or titanomagnetite, but there is no explanation for the observed behaviours yet. This study sets out to determine which physical property (grain size, foreign cations content and domain walls displacements) controls the initial susceptibility. The performed measurements include microprobe analysis to determine magnetic phases different to haematite; initial susceptibility (300 K); hysteresis loops, SIRM and backfield curves at 77 and 300 K to calculate magnetic parameters and minor loops at 77 K, to analyse initial susceptibility and magnetization behaviours below Morin transition. The magnetic moment study at low temperature is completed with measurements of zero field cooled-field cooled and AC susceptibility in a range from 5 to 300 K. The minor loops show that the non-linearity of initial susceptibility is closely related to Barkhausen jumps. Because of initial magnetic susceptibility is controlled by domain structure it is difficult to establish a mathematical model to separate magnetic subfabrics in haematite-bearing rocks.

Towards the design of monolithic decoupled XYZ compliant parallel mechanisms for multi-function applications

This paper deals with the monolithic decoupled XYZ compliant parallel mechanisms (CPMs) for multi-function applications, which can be fabricated monolithically without assembly and has the capability of kinetostatic decoupling. At first, the conceptual design of monolithic decoupled XYZ CPMs is presented using identical spatial compliant multi-beam modules based on a decoupled 3-PPPR parallel kinematic mechanism. Three types of applications: motion/positioning stages, force/acceleration sensors and energy harvesting devices are described in principle. The kinetostatic and dynamic modelling is then conducted to capture the displacements of any stage under loads acting at any stage and the natural frequency with the comparisons with FEA results. Finally, performance characteristics analysis for motion stage applications is detailed investigated to show how the change of the geometrical parameter can affect the performance characteristics, which provides initial optimal estimations. Results show that the smaller thickness of beams and larger dimension of cubic stages can improve the performance characteristics excluding natural frequency under allowable conditions. In order to improve the natural frequency characteristic, a stiffness-enhanced monolithic decoupled configuration that is achieved through employing more beams in the spatial modules or reducing the mass of each cubic stage mass can be adopted. In addition, an isotropic variation with different motion range along each axis and same payload in each leg is proposed. The redundant design for monolithic fabrication is introduced in this paper, which can overcome the drawback of monolithic fabrication that the failed compliant beam is difficult to replace, and extend the CPM’s life.

Large magnetoelectric coupling in nanoscale BiFeO3 from direct electrical measurements

We report the results of direct measurement of remanent hysteresis loops on nanochains of BiFeO3 at room temperature under zero and ∼20 kOe magnetic field. We noticed a suppression of remanent polarization by nearly ∼40% under the magnetic field. The powder neutron diffraction data reveal significant ion displacements under a magnetic field which seems to be the origin of the suppression of polarization. The isolated nanoparticles, comprising the chains, exhibit evolution of ferroelectric domains under dc electric field and complete 180 switching in switching-spectroscopy piezoresponse force microscopy. They also exhibit stronger ferromagnetism with nearly an order of magnitude higher saturation magnetization than that of the bulk sample. These results show that the nanoscale BiFeO3 exhibits coexistence of ferroelectric and ferromagnetic order and a strong magnetoelectric multiferroic coupling at room temperature comparable to what some of the type-II multiferroics show at a very low temperature.

Constraint-force-based approach of modelling compliant mechanisms: principle and application

Numerous works have been conducted on modelling basic compliant elements such as wire beams, and closed-form analytical models of most basic compliant elements have been well developed. However, the modelling of complex compliant mechanisms is still a challenging work. This paper proposes a constraint-force-based (CFB) modelling approach to model compliant mechanisms with a particular emphasis on modelling complex compliant mechanisms. The proposed CFB modelling approach can be regarded as an improved free-body- diagram (FBD) based modelling approach, and can be extended to a development of the screw-theory-based design approach. A compliant mechanism can be decomposed into rigid stages and compliant modules. A compliant module can offer elastic forces due to its deformation. Such elastic forces are regarded as variable constraint forces in the CFB modelling approach. Additionally, the CFB modelling approach defines external forces applied on a compliant mechanism as constant constraint forces. If a compliant mechanism is at static equilibrium, all the rigid stages are also at static equilibrium under the influence of the variable and constant constraint forces. Therefore, the constraint force equilibrium equations for all the rigid stages can be obtained, and the analytical model of the compliant mechanism can be derived based on the constraint force equilibrium equations. The CFB modelling approach can model a compliant mechanism linearly and nonlinearly, can obtain displacements of any points of the rigid stages, and allows external forces to be exerted on any positions of the rigid stages. Compared with the FBD based modelling approach, the CFB modelling approach does not need to identify the possible deformed configuration of a complex compliant mechanism to obtain the geometric compatibility conditions and the force equilibrium equations. Additionally, the mathematical expressions in the CFB approach have an easily understood physical meaning. Using the CFB modelling approach, the variable constraint forces of three compliant modules, a wire beam, a four-beam compliant module and an eight-beam compliant module, have been derived in this paper. Based on these variable constraint forces, the linear and non-linear models of a decoupled XYZ compliant parallel mechanism are derived, and verified by FEA simulations and experimental tests.

Accumulation de dose à partir de champs de déformation 4D appliqués aux traitements au CyberKnife et à l'IMRT

Le cancer pulmonaire est la principale cause de décès parmi tous les cancers au Canada. Le pronostic est généralement faible, de l'ordre de 15% de taux de survie après 5 ans. Les déplacements internes des structures anatomiques apportent une incertitude sur la précision des traitements en radio-oncologie, ce qui diminue leur efficacité. Dans cette optique, certaines techniques comme la radio-chirurgie et la radiothérapie par modulation de l'intensité (IMRT) visent à améliorer les résultats cliniques en ciblant davantage la tumeur. Ceci permet d'augmenter la dose reçue par les tissus cancéreux et de réduire celle administrée aux tissus sains avoisinants. Ce projet vise à mieux évaluer la dose réelle reçue pendant un traitement considérant une anatomie en mouvement. Pour ce faire, des plans de CyberKnife et d'IMRT sont recalculés en utilisant un algorithme Monte Carlo 4D de transport de particules qui permet d'effectuer de l'accumulation de dose dans une géométrie déformable. Un environnement de simulation a été développé afin de modéliser ces deux modalités pour comparer les distributions de doses standard et 4D. Les déformations dans le patient sont obtenues en utilisant un algorithme de recalage déformable d'image (DIR) entre les différentes phases respiratoire générées par le scan CT 4D. Ceci permet de conserver une correspondance de voxels à voxels entre la géométrie de référence et celles déformées. La DIR est calculée en utilisant la suite ANTs («Advanced Normalization Tools») et est basée sur des difféomorphismes. Une version modifiée de DOSXYZnrc de la suite EGSnrc, defDOSXYZnrc, est utilisée pour le transport de particule en 4D. Les résultats sont comparés à une planification standard afin de valider le modèle actuel qui constitue une approximation par rapport à une vraie accumulation de dose en 4D.

Modeling of a Heat-Induced Buckling of Plates Using the Mesh-free Method

In the process of engineering design of structural shapes, the flat plate analysis results can be generalized to predict behaviors of complete structural shapes. In this case, the purpose of this project is to analyze a thin flat plate under conductive heat transfer and to simulate the temperature distribution, thermal stresses, total displacements, and buckling deformations. The current approach in these cases has been using the Finite Element Method (FEM), whose basis is the construction of a conforming mesh. In contrast, this project uses the mesh-free Scan Solve Method. This method eliminates the meshing limitation using a non-conforming mesh. I implemented this modeling process developing numerical algorithms and software tools to model thermally induced buckling. In addition, convergence analysis was achieved, and the results were compared with FEM. In conclusion, the results demonstrate that the method gives similar solutions to FEM in quality, but it is computationally less time consuming.

Recorridos, tensiones y desplazamientos en el ideario de Alicia Moreau

Este estudio es, en primer lugar, un ejercicio de visibilización de la obra de Alicia Moreau de Justo -una de las figuras centrales del feminismo sufragista argentino y un primer paso para problematizar la relación entre su ideario, la coyuntura y los procesos históricos que le tocaron vivir. Nos proponemos analizar su producción profesional y política señalando cómo va modelando sus miradas sobre las mujeres y la acción política. Al mismo tiempo, y en estrecha vinculación a lo anterior, ella construye una propuesta democratizadora que se tensará con la llegada de Juan Domingo Perón al gobierno en 1946 y aún después de que éste fue derrocado

Recorridos, tensiones y desplazamientos en el ideario de Alicia Moreau

Este estudio es, en primer lugar, un ejercicio de visibilización de la obra de Alicia Moreau de Justo -una de las figuras centrales del feminismo sufragista argentino y un primer paso para problematizar la relación entre su ideario, la coyuntura y los procesos históricos que le tocaron vivir. Nos proponemos analizar su producción profesional y política señalando cómo va modelando sus miradas sobre las mujeres y la acción política. Al mismo tiempo, y en estrecha vinculación a lo anterior, ella construye una propuesta democratizadora que se tensará con la llegada de Juan Domingo Perón al gobierno en 1946 y aún después de que éste fue derrocado

Recorridos, tensiones y desplazamientos en el ideario de Alicia Moreau

Este estudio es, en primer lugar, un ejercicio de visibilización de la obra de Alicia Moreau de Justo -una de las figuras centrales del feminismo sufragista argentino y un primer paso para problematizar la relación entre su ideario, la coyuntura y los procesos históricos que le tocaron vivir. Nos proponemos analizar su producción profesional y política señalando cómo va modelando sus miradas sobre las mujeres y la acción política. Al mismo tiempo, y en estrecha vinculación a lo anterior, ella construye una propuesta democratizadora que se tensará con la llegada de Juan Domingo Perón al gobierno en 1946 y aún después de que éste fue derrocado

Monitoring of Dynamic Bridge Behaviour Using Digital Image Correlation

Bridges are a critical part of North America’s transportation network that need to be assessed frequently to inform bridge management decision making. Visual inspections are usually implemented for this purpose, during which inspectors must observe and report any excess displacements or vibrations. Unfortunately, these visual inspections are subjective and often highly variable and so a monitoring technology that can provide quantitative measurements to supplement inspections is needed. Digital Image Correlation (DIC) is a novel monitoring technology that uses digital images to measure displacement fields without any contact with the bridge. In this research, DIC and accelerometers were used to investigate the dynamic response of a railway bridge reported to experience large lateral displacements. Displacements were estimated using accelerometer measurements and were compared to DIC measurements. It was shown that accelerometers can provide reasonable estimates of displacement for zero-mean lateral displacements. By comparing measurements in the girder and in the piers, it was shown that for the bridge monitored, the large lateral displacements originated in the steel casting bearings positioned above the piers, and not in the piers themselves. The use of DIC for evaluating the effectiveness of rehabilitation of the LaSalle Causeway lift bridge in Kingston, Ontario was also investigated. Vertical displacements were measured at midspan and at the lifting end of the bridge during a static test and under dynamic live loading. The bridge displacements were well within the operating limits, however a gap at the lifting end of the bridge was identified. Rehabilitation of the bridge was conducted and by comparing measurements before and after rehabilitation, it was shown that the gap was successfully closed. Finally, DIC was used to monitor the midspan vertical and lateral displacements in a monitoring campaign of five steel rail bridges. DIC was also used to evaluate the effectiveness of structural rehabilitation of the lateral bracing of a bridge. Simple finite element models are developed using DIC measurements of displacement. Several lessons learned throughout this monitoring campaign are discussed in the hope of aiding future researchers.

Metamorfosis en la energía mítica:de la libido freudiana a la libido electrónica y digital

La historia de la mitología puede ser narrada como la crónica de las sucesivas metamorfosis de las fuentes de energía mítica y sus desplazamientos metafóricos de sentido. La modernidad se distingue por haber descubierto un manantial inédito de energía mítica, la libido freudiana. Desde su despertar surrealista, donde se creía inagotable, hasta su empleo por parte de los dispositivos pulsionales de Internet, el imaginario de la libido freudiana está sufriendo una mutación como libido digital: una crisis energética que supone una lectura renovada del imaginario edípico (crisis de la diacronía) y un estudio de sus más recientes rituales electrónicos (crisis de la sincronía) en la era de Internet.

Model reduction for nonlinear aerodynamics and aeroelasticity using a Discrete Empirical Interpolation Method

A novel surrogate model is proposed in lieu of Computational Fluid Dynamics (CFD) solvers, for fast nonlinear aerodynamic and aeroelastic modeling. A nonlinear function is identified on selected interpolation points by
a discrete empirical interpolation method (DEIM). The flow field is then reconstructed using a least square approximation of the flow modes extracted
by proper orthogonal decomposition (POD). The aeroelastic reduce order
model (ROM) is completed by introducing a nonlinear mapping function
between displacements and the DEIM points. The proposed model is investigated to predict the aerodynamic forces due to forced motions using
a N ACA 0012 airfoil undergoing a prescribed pitching oscillation. To investigate aeroelastic problems at transonic conditions, a pitch/plunge airfoil
and a cropped delta wing aeroelastic models are built using linear structural models. The presence of shock-waves triggers the appearance of limit
cycle oscillations (LCO), which the model is able to predict. For all cases
tested, the new ROM shows the ability to replicate the nonlinear aerodynamic forces, structural displacements and reconstruct the complete flow
field with sufficient accuracy at a fraction of the cost of full order CFD
model.