10 research outputs found

    Scientific and Technical Publishing at Goddard Space Flight Center in Fiscal Year 1994

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    This publication is a compilation of scientific and technical material that was researched, written, prepared, and disseminated by the Center's scientists and engineers during FY94. It is presented in numerical order of the GSFC author's sponsoring technical directorate; i.e., Code 300 is the Office of Flight Assurance, Code 400 is the Flight Projects Directorate, Code 500 is the Mission Operations and Data Systems Directorate, Code 600 is the Space Sciences Directorate, Code 700 is the Engineering Directorate, Code 800 is the Suborbital Projects and Operations Directorate, and Code 900 is the Earth Sciences Directorate. The publication database contains publication or presentation title, author(s), document type, sponsor, and organizational code. This is the second annual compilation for the Center

    A gravel-sand bifurcation:a simple model and the stability of the equilibrium states

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    A river bifurcation, can be found in, for instance, a river delta, in braided or anabranching reaches, and in manmade side channels in restored river reaches. Depending on the partitioning of water and sediment over the bifurcating branches, the bifurcation develops toward (a) a stable state with two downstream branches or (b) a state in which the water discharge in one of the branches continues to increase at the expense of the other branch (Wang et al., 1995). This may lead to excessive deposition in the latter branch that eventually silts up. For navigation, flood safety, and river restoration purposes, it is important to assess and develop tools to predict such long-term behavior of the bifurcation. A first and highly schematized one-dimensional model describing (the development towards) the equilibrium states of two bifurcating branches was developed by Wang et al (1995). The use of a one-dimensional model implies the need for a nodal point relation that describes the partitioning of sediment over the bifurcating branches. Wang et al (1995) introduce a nodal point relation as a function of the partitioning of the water discharge. They simplify their nodal point relation to the following form: s*=q*k , where s* denotes the ratio of the sediment discharges per unit width in the bifurcating branches, q* denotes the ratio of the water discharges per unit width in the bifurcating branches, and k is a constant. The Wang et al. (1995) model is limited to conditions with unisize sediment and application of the Engelund & Hansen (1967) sediment transport relation. They assume the same constant base level for the two bifurcating branches, and constant water and sediment discharges in the upstream channel. A mathematical stability analysis is conducted to predict the stability of the equilibrium states. Depending on the exponent k they find a stable equilibrium state with two downstream branches or a stable state with one branch only (i.e. the other branch has silted up). Here we extend the Wang et al. (1995) model to conditions with gravel and sand and study the stability of the equilibrium states

    Deep learning of brain asymmetry digital biomarkers to support early diagnosis of cognitive decline and dementia

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    Early identification of degenerative processes in the human brain is essential for proper care and treatment. This may involve different instrumental diagnostic methods, including the most popular computer tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. These technologies provide detailed information about the shape, size, and function of the human brain. Structural and functional cerebral changes can be detected by computational algorithms and used to diagnose dementia and its stages (amnestic early mild cognitive impairment - EMCI, Alzheimer’s Disease - AD). They can help monitor the progress of the disease. Transformation shifts in the degree of asymmetry between the left and right hemispheres illustrate the initialization or development of a pathological process in the brain. In this vein, this study proposes a new digital biomarker for the diagnosis of early dementia based on the detection of image asymmetries and crosssectional comparison of NC (normal cognitively), EMCI and AD subjects. Features of brain asymmetries extracted from MRI of the ADNI and OASIS databases are used to analyze structural brain changes and machine learning classification of the pathology. The experimental part of the study includes results of supervised machine learning algorithms and transfer learning architectures of convolutional neural networks for distinguishing between cognitively normal subjects and patients with early or progressive dementia. The proposed pipeline offers a low-cost imaging biomarker for the classification of dementia. It can be potentially helpful to other brain degenerative disorders accompanied by changes in brain asymmetries

    GEOBIA 2016 : Solutions and Synergies., 14-16 September 2016, University of Twente Faculty of Geo-Information and Earth Observation (ITC): open access e-book

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    An integrated seismic-scale analysis of reservoir compartmentalisation on continental margins : the Espirito Santo Basin, SE Brazil

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    Deepwater continental margins constitute one of the ultimate exploration frontiers where giant oilfields have been discovered. These comprise reservoirs units affected by multi‐scale compartmentalisation resultant from stratigraphic, structural and/or diagenetic processes that compromise the lateral and/or vertical connectivity of permeable strata. A 3D seismic dataset from the deepwater Espírito Santo Basin (SE Brazil) was analysed to assess and quantify the architectural elements that influence the compartmentalisation of reservoir units. Mass‐Transport Deposits (MTDs) have growing importance on reservoir studies as they highly impact the compartmentalisation of contemporaneous reservoir‐prone turbidite strata. More significant compartmentalisation occurs in areas with higher MTD proportion, which are associated to wider dimensional ranges of laterally limited turbidites. However, salt diapirs constitute important barriers for MTD erosion, thus aiding the preservation of reservoir‐prone turbidites. The internal compositional heterogeneities and cohese strata on remnant and rafted blocks identified within the studied MTDs constitute important fluid flow or accumulation compartments, particularly when linked to underlying permeable faults. Submarine channels in Palaeocene and Neogene Units comprise important reservoir‐prone strata, thus it is crucial to understand their spatial distribution. Large channels are focused along the axis of salt‐withdrawal basins, whereas in sub‐units with numerous smaller channels these are laterally scattered across the basin. A new quantitative method used in this study shows that channel confluences and topographic confinement control significantly the density and spatial distribution patterns of submarine channels. A novel classification for submarine channel confluences is proposed, based on channel morphology and distribution of sediment facies within the tributaries. The key aim of this thesis was to undertake a seismic‐scale qualitative and quantitative analysis of the compartmentalisation of reservoir units on the Brazilian margin using methodologies that can be applied to other continental margins worldwide. As such, the results of this study can provide significant contributions for hydrocarbon exploration.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    INTER-ENG 2020

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    These proceedings contain research papers that were accepted for presentation at the 14th International Conference Inter-Eng 2020 ,Interdisciplinarity in Engineering, which was held on 8–9 October 2020, in Târgu Mureș, Romania. It is a leading international professional and scientific forum for engineers and scientists to present research works, contributions, and recent developments, as well as current practices in engineering, which is falling into a tradition of important scientific events occurring at Faculty of Engineering and Information Technology in the George Emil Palade University of Medicine, Pharmacy Science, and Technology of Târgu Mures, Romania. The Inter-Eng conference started from the observation that in the 21st century, the era of high technology, without new approaches in research, we cannot speak of a harmonious society. The theme of the conference, proposing a new approach related to Industry 4.0, was the development of a new generation of smart factories based on the manufacturing and assembly process digitalization, related to advanced manufacturing technology, lean manufacturing, sustainable manufacturing, additive manufacturing, and manufacturing tools and equipment. The conference slogan was “Europe’s future is digital: a broad vision of the Industry 4.0 concept beyond direct manufacturing in the company”

    An integrated seismic-scale analysis of reservoir compartmentalisation on continental margins: the Espirito Santo Basin, SE Brazil

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    Deepwater continental margins constitute one of the ultimate exploration frontiers where giant oilfields have been discovered. These comprise reservoirs units affected by multi‐scale compartmentalisation resultant from stratigraphic, structural and/or diagenetic processes that compromise the lateral and/or vertical connectivity of permeable strata. A 3D seismic dataset from the deepwater Espírito Santo Basin (SE Brazil) was analysed to assess and quantify the architectural elements that influence the compartmentalisation of reservoir units. Mass‐Transport Deposits (MTDs) have growing importance on reservoir studies as they highly impact the compartmentalisation of contemporaneous reservoir‐prone turbidite strata. More significant compartmentalisation occurs in areas with higher MTD proportion, which are associated to wider dimensional ranges of laterally limited turbidites. However, salt diapirs constitute important barriers for MTD erosion, thus aiding the preservation of reservoir‐prone turbidites. The internal compositional heterogeneities and cohese strata on remnant and rafted blocks identified within the studied MTDs constitute important fluid flow or accumulation compartments, particularly when linked to underlying permeable faults. Submarine channels in Palaeocene and Neogene Units comprise important reservoir‐prone strata, thus it is crucial to understand their spatial distribution. Large channels are focused along the axis of salt‐withdrawal basins, whereas in sub‐units with numerous smaller channels these are laterally scattered across the basin. A new quantitative method used in this study shows that channel confluences and topographic confinement control significantly the density and spatial distribution patterns of submarine channels. A novel classification for submarine channel confluences is proposed, based on channel morphology and distribution of sediment facies within the tributaries. The key aim of this thesis was to undertake a seismic‐scale qualitative and quantitative analysis of the compartmentalisation of reservoir units on the Brazilian margin using methodologies that can be applied to other continental margins worldwide. As such, the results of this study can provide significant contributions for hydrocarbon exploration

    Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

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    Second International Conference on Sustainable Futures: Environmental, Technological, Social and Economic Matters (ICSF 2021). Kryvyi Rih, Ukraine, May 19-21, 2021.Друга міжнародна конференція зі сталого майбутнього: екологічні, технологічні, соціальні та економічні питання (ICSF 2021). Кривий Ріг, Україна, 19-21 травня 2021 року

    Spacelab Science Results Study

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    Beginning with OSTA-1 in November 1981 and ending with Neurolab in March 1998, a total of 36 Shuttle missions carried various Spacelab components such as the Spacelab module, pallet, instrument pointing system, or mission peculiar experiment support structure. The experiments carried out during these flights included astrophysics, solar physics, plasma physics, atmospheric science, Earth observations, and a wide range of microgravity experiments in life sciences, biotechnology, materials science, and fluid physics which includes combustion and critical point phenomena. In all, some 764 experiments were conducted by investigators from the U.S., Europe, and Japan. The purpose of this Spacelab Science Results Study is to document the contributions made in each of the major research areas by giving a brief synopsis of the more significant experiments and an extensive list of the publications that were produced. We have also endeavored to show how these results impacted the existing body of knowledge, where they have spawned new fields, and if appropriate, where the knowledge they produced has been applied
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