988 resultados para seismic reflection


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Aspirations for higher education by people from low socioeconomic status backgrounds are now a focus of government policy in many OECD nations. This is part of a global trend emphasizing the perceived benefits of ‘raising’ aspirations among under-represented groups as a social inclusion strategy to widen university participation, but also ultimately as a strategy to increase national competitiveness in the global knowledge economy. Yet despite its importance, aspiration tends to carry simplistic meanings in much higher education policy and practice. This paper attempts to craft a more nuanced account of the term, informed by four concept-clusters derived from sociological and philosophical literatures and research, and with a more mutual relation of public and private interests. It complements this ‘intellectual craftsmanship’ or ‘systematic reflection’ (Mills in The sociological imagination, 1959) with data drawn from a future-focused survey of secondary school students from low and low-mid socioeconomic status backgrounds in regional Australia. Results from the survey provide illustrations that help expand understandings of student aspirations for higher education, from a group presumed to be deficit in aspirations.

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Short-term international practicum experience is now a feature of many university education programs in Australia in an attempt to engage students with the growing multi-cultural aspects of Australian life. The stated purposes of such practicum experiences generally highlight intercultural learning, which is associated with the development of intercultural sensitivity, cultural identity, global citizenship and global competence. This paper tracks and documents the early and developing attitudes and dispositions of a group of pre-service teachers (PSTs) and academic staffwho were engaged with the pilot project of a pre-service placement in Malaysian secondary schools. The behaviours associated with intercultural learning are observed in association with the students' responses to changing circumstances. The paper draws attention to lessons learnt about orientation for intercultural exchanges in the development of intercultural learning and suggests ways to enhance the development of intercultural understandings and minimize cultural difference through more targeted interventions.

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© 2015 Australian Psychological Society. Objective: The use of self-practice and self-reflection has been proposed as an efficacious strategy in the training of therapists. It has been argued to enhance therapist skills, and a key factor in the development of expertise. This systematic literature review investigated the effect of self-practice and self-reflection on therapist skills development. Method: Studies were identified through Medline, Academic Search Complete, PsychINFO, PsycARTICLES, Proquest, ISI, CINAHL, Cochrane, and Scopus databases. Additional studies were identified through lateral searches of relevant papers' reference lists and direct correspondence with authors of unpublished material. The selection criteria were studies that investigated the effect of self-practice and/or self-reflection on therapist skill development. There was no restriction on sample sizes, design of studies, dates of publication, or peer-reviewed papers. All studies were published in English. Results: Ten studies were included in this review. A thematic analysis was undertaken to analyse qualitative data. Due to inconsistency in the variables investigated across the quantitative studies, quantitative results were not subject to a meta-analysis but simply reported. Finally, qualitative and quantitative data were juxtaposed in a meta-synthesis. Conclusion: The meta-synthesis revealed inconsistencies between the qualitative and quantitative literature and a gap in relation to declarative knowledge. Methodological limitations across studies are discussed and recommendations for future research provided.

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Technologies, such as Atomic Force Microscopy (AFM), have proven to be one of the most versatile research equipments in the field of nanotechnology by providing physical access to the materials at nanoscale. Working principles of AFM involve physical interaction with the sample at nanometre scale to estimate the topography of the sample surface. Size of the cantilever tip, within the range of few nanometres diameter, and inherent elasticity of the cantilever allow it to bend in response to the changes in the sample surface leading to accurate estimation of the sample topography. Despite the capabilities of the AFM, there is a lack of intuitive user interfaces that could allow interaction with the materials at nanoscale, analogous to the way we are accustomed to at macro level. To bridge this gap of intuitive interface design and development, a haptics interface is designed in conjunction with Bruker Nanos AFM. Interaction with the materials at nanoscale is characterised by estimating the forces experienced by the cantilever tip employing geometric deformation principles. Estimated forces are reflected to the user, in a controlled manner, through haptics interface. Established mathematical framework for force estimation can be adopted for AFM operations in air as well as in liquid mediums.

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Critical reflection (CR) is at the core of postgraduate studies in c, and students from Asia in general, and from c in particular, often find the concept challenging when reading texts or applying it to written texts in English. This study reports on a case study of a Chinese postgraduate student in Australia. It explores the challenges and obstacles in terms of CR that she faced while completing her subjects in a TESOL program in Australia. These challenges were articulated in a semi-structured interview conducted with the student. Challenges include English language proficiency, lack of focus on writing in China where there is a lot of emphasis on memorisation, different systems of conceptualisation of topics in Chinese and English, and limited freedom of expression which is expressed as ‘authoritative’ control in the Chinese educational context.

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Trabalho apresentado na conferência Os Desafios das Bibliotecas Digitais realizado na Fundação Getulio Vargas em agosto 2014

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In geophysics there are several steps in the study of the Earth, one of them is the processing of seismic records. These records are obtained through observations made on the earth surface and are useful for information about the structure and composition of the inaccessible parts in great depths. Most of the tools and techniques developed for such studies has been applied in academic projects. The big problem is that the seismic processing power unwanted, recorded by receivers that do not bring any kind of information related to the reflectors can mask the information and/or generate erroneous information from the subsurface. This energy is known as unwanted seismic noise. To reduce the noise and improve a signal indicating a reflection, without losing desirable signals is sometimes a problem of difficult solution. The project aims to get rid of the ground roll noise, which shows a pattern characterized by low frequency, low rate of decay, low velocity and high amplituds. The Karhunen-Loève Transform is a great tool for identification of patterns based on the eigenvalues and eigenvectors. Together with the Karhunen-Loève Transform we will be using the Singular Value Decomposition, since it is a great mathematical technique for manipulating data

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This work presents recent improvements in a density measurement cell with a double-element transducer that can eliminate diffraction effects. A new mechanical design combined with the use of more appropriate materials has resulted in better parallelism between interfaces, more robust assembly, and chemical resistance. A novel method of signal processing, named energy method, is introduced to obtain the reflection coefficient, reducing sensitivity to noise and improving accuracy. The measurement cell operation is verified both theoretically, using an acoustic wave propagation model, and experimentally, using homogeneous liquids with different densities. The accuracy in the density measurement is 0.2% when compared with the measurements made with a pycnometer.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In Fazenda Belém oil field (Potiguar Basin, Ceará State, Brazil) occur frequently sinkholes and sudden terrain collapses associated to an unconsolidated sedimentary cap covering the Jandaíra karst. This research was carried out in order to understand the mechanisms of generation of these collapses. The main tool used was Ground Penetrating Radar (GPR). This work is developed twofold: one aspect concerns methodology improvements in GPR data processing whilst another aspect concerns the geological study of the Jandaíra karst. This second aspect was strongly supported both by the analysis of outcropping karst structures (in another regions of Potiguar Basin) and by the interpretation of radargrams from the subsurface karst in Fazenda Belém. It was designed and tested an adequate flux to process GPR data which was adapted from an usual flux to process seismic data. The changes were introduced to take into account important differences between GPR and Reflection Seismic methods, in particular: poor coupling between source and ground, mixed phase of the wavelet, low signal-to-noise ratio, monochannel acquisition, and high influence of wave propagation effects, notably dispersion. High frequency components of the GPR pulse suffer more pronounced effects of attenuation than low frequency components resulting in resolution losses in radargrams. In Fazenda Belém, there is a stronger need of an suitable flux to process GPR data because both the presence of a very high level of aerial events and the complexity of the imaged subsurface karst structures. The key point of the processing flux was an improvement in the correction of the attenuation effects on the GPR pulse based on their influence on the amplitude and phase spectra of GPR signals. In low and moderate losses dielectric media the propagated signal suffers significant changes only in its amplitude spectrum; that is, the phase spectrum of the propagated signal remains practically unaltered for the usual travel time ranges. Based on this fact, it is shown using real data that the judicious application of the well known tools of time gain and spectral balancing can efficiently correct the attenuation effects. The proposed approach can be applied in heterogeneous media and it does not require the precise knowledge of the attenuation parameters of the media. As an additional benefit, the judicious application of spectral balancing promotes a partial deconvolution of the data without changing its phase. In other words, the spectral balancing acts in a similar way to a zero phase deconvolution. In GPR data the resolution increase obtained with spectral balancing is greater than those obtained with spike and predictive deconvolutions. The evolution of the Jandaíra karst in Potiguar Basin is associated to at least three events of subaerial exposition of the carbonatic plataform during the Turonian, Santonian, and Campanian. In Fazenda Belém region, during the mid Miocene, the Jandaíra karst was covered by continental siliciclastic sediments. These sediments partially filled the void space associated to the dissolution structures and fractures. Therefore, the development of the karst in this region was attenuated in comparison to other places in Potiguar Basin where this karst is exposed. In Fazenda Belém, the generation of sinkholes and terrain collapses are controlled mainly by: (i) the presence of an unconsolidated sedimentary cap which is thick enough to cover completely the karst but with sediment volume lower than the available space associated to the dissolution structures in the karst; (ii) the existence of important structural of SW-NE and NW-SE alignments which promote a localized increase in the hydraulic connectivity allowing the channeling of underground water, thus facilitating the carbonatic dissolution; and (iii) the existence of a hydraulic barrier to the groundwater flow, associated to the Açu-4 Unity. The terrain collapse mechanisms in Fazenda Belém occur according to the following temporal evolution. The meteoric water infiltrates through the unconsolidated sedimentary cap and promotes its remobilization to the void space associated with the dissolution structures in Jandaíra Formation. This remobilization is initiated at the base of the sedimentary cap where the flow increases its abrasion due to a change from laminar to turbulent flow regime when the underground water flow reaches the open karst structures. The remobilized sediments progressively fill from bottom to top the void karst space. So, the void space is continuously migrated upwards ultimately reaching the surface and causing the sudden observed terrain collapses. This phenomenon is particularly active during the raining season, when the water table that normally is located in the karst may be temporarily located in the unconsolidated sedimentary cap

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The main objective of the present thesis was the seismic interpretation and seismic attribute analysis of the 3D seismic data from the Siririzinho high, located in the Sergipe Sub-basin (southern portion of Sergipe-Alagoas Basin). This study has enabled a better understanding of the stratigraphy and structure that the Siririzinho high experienced during its development. In a first analysis, we used two types of filters: the dip-steered median filter, was used to remove random noise and increase the lateral continuity of reflections, and fault-enhancement filter was applied to enhance the reflection discontinuities. After this filtering step similarity and curvature attributes were applied in order to identify and enhance the distribution of faults and fractures. The use of attributes and filtering greatly contributed to the identification and enhancement of continuity of faults. Besides the application of typical attributes (similarity and curvature) neural network and fingerprint techniques were also used, which generate meta-attributes, also aiming to highlight the faults; however, the results were not satisfactory. In a subsequent step, well log and seismic data analysis were performed, which allowed the understanding of the distribution and arrangement of sequences that occur in the Siririzinho high, as well as an understanding of how these units are affected by main structures in the region. The Siririzinho high comprises an elongated structure elongated in the NS direction, capped by four seismo-sequences (informally named, from bottom to top, the sequences I to IV, plus the top of the basement). It was possible to recognize the main NS-oriented faults, which especially affect the sequences I and II, and faults oriented NE-SW, that reach the younger sequences, III and IV. Finally, with the interpretation of seismic horizons corresponding to each of these sequences, it was possible to define a better understanding of geometry, deposition and structural relations in the area.

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Saliva has become an important resource for evaluating physiological and pathological conditions in humans. The use of saliva has many advantages, including the simple and non-invasive method of collection and its easy, low-cost storage. With the addition of modern techniques and chemical instrumentation equipment, there has been an increase in its use for laboratory investigations, applicable for basic and clinical analyses in the fields of medicine and dentistry. The value of these methods for the diagnosis of oral and systemic diseases has been the subject of study by several researchers with the aim of increasing its use alongside complementary exams. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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We consider numerical data for the lattice Landau gluon propagator obtained at very large lattice volumes in three-dimensional pure SU(2) Yang-Mills gauge theory (YM32). We find that the temporal correlator C(t) shows an oscillatory pattern and is negative for several values of t. This is an explicit violation of reflection positivity and can be related to gluon confinement. We also obtain a good fit for this quantity in the whole time interval using a sum of Stingl-like propagators.