2,229 research outputs found

    Time comparison via OTS-2

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    The time comparisons carried out via OTS-2 between the Technical University Graz (Austria) and the Van Swinden Laboratory Delft (Netherlands) are discussed. The method is based on the use of the synchronization pulse in the TV-frame of the daily evening broadcasting of a French TV-program to Northern Africa. Corrections, as a consequence of changes in the position of the satellite coordinates are applied weekly after reception of satellite coordinates. A description of the method is given as well as some of the particular techniques used in both the participating laboratories. Preliminary results are presented

    High spring temperatures decrease peach fruit size

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    The hippocampus and its role in memory : Clinical manifestations and theoretical considerations

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    Using as the basis for discussion a case report of a patient who had developed severe memory impairment without other evidence of neurologic involvement following barbiturate and nitrous oxide anesthesia, and who was found to have bilateral infarcts involving the hippocampi and neighboring structures, the relationship of the hippocampus to memory is discussed. There have been a few other similar cases reported. Memory loss often follows bilateral temporal lobectomy, and even unilateral temporal lobectomy if section includes portions of the uncus, parahippocampal gyrus and hippocampus. Stimulation of the hippocampus also causes disturbances of memory. While there is no memory "center", and lesions of various portions of the nervous system may affect memory, the hippocampi appear to be crucial for certain memory functions, and small lesions in them may cause profound disturbances of memory and learning.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33882/1/0000147.pd

    Space construction system analysis. Part 2: Platform definition

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    The top level system requirements are summarized and the accompanying conceptual design for an engineering and technology verification platform (ETVP) system is presented. An encompassing statement of the system objectives which drive the system requirements is presented and the major mission and subsystem requirements are described with emphasis on the advanced communications technology mission payload. The platform design is defined and used as a reference configuration for an end to space construction analyses. The preferred construction methods and processes, the important interactions between the platform design and the construction system design and operation, and the technology development efforts required to support the design and space construction of the ETVP are outlined

    CFD analyses for advanced pump design

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    As one of the activities of the NASA/MSFC Pump Stage Technology Team, the present effort was focused on using CFD in the design and analysis of high performance rocket engine pumps. Under this effort, a three-dimensional Navier-Stokes code was used for various inducer and impeller flow field calculations. An existing algebraic grid generation procedure was-extended to allow for nonzero blade thickness, splitter blades, and hub/shroud cavities upstream or downstream of the (main) blades. This resulted in a fast, robust inducer/impeller geometry/grid generation package. Problems associated with running a compressible flow code to simulate an incompressible flow were resolved; related aspects of the numerical algorithm (viz., the matrix preconditioning, the artificial dissipation, and the treatment of low Mach number flows) were addressed. As shown by the calculations performed under the present effort, the resulting code, in conjunction with the grid generation package, is an effective tool for the rapid solution of three-dimensional viscous inducer and impeller flows

    Effects of Sample Disturbance and Consolidation Procedures on Cyclic Strengths of Intermediate Soils

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    Sampling and testing of soils to measure engineering properties, such as monotonic and cyclic undrained shear strengths, requires an understanding of the potential effects of sampling disturbance and the selection of appropriate laboratory testing procedures. For clays, past research has provided insights on how sampling methods and laboratory testing procedures can be used in practice to assess and minimize sample disturbance effects. For sands, past research has shown that conventional tube sampling techniques cause excessive disturbance to the soil fabric, such that subsequent measurement of monotonic or cyclic strengths can be greatly in error and misleading. For intermediate soils, the effects of disturbance and consolidation procedures on monotonic and cyclic strengths are not well understood. In the present study, a test protocol was developed to assess the effects that disturbance during sample extrusion, trimming, and mounting have on subsequent measurements of compressibility, monotonic undrained strength, and cyclic undrained strength. Detailed laboratory tests were performed on tube samples from deposits of low-plasticity silty clay, for which conventional sampling and testing were expected to work reasonably well, and low-plasticity clayey sand, for which the effects of sample disturbance were of primary concern. Test results using this protocol for these two soils are presented and discussed

    Guided self-help interventions for mental health disorders in children with neurological conditions: study protocol for a pilot randomised controlled

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    Background: Rates of mental health disorders are significantly greater in children with physical illnesses than in physically well children. Children with neurological conditions, such as epilepsy, are known to have particularly high rates of mental health disorders. Despite this, mental health problems in children with neurological conditions have remained under-recognised and under-treated in clinical settings. Evidence-based guided self-help interventions are efficacious in reducing symptoms of mental health disorders in children, but their efficacy in reducing symptoms of common mental health disorders in children with neurological conditions has not been investigated. We aim to pilot a guided self-help intervention for the treatment of mental health disorders in children with neurological conditions. Methods/design: A pilot randomised controlled trial with 18 patients with neurological conditions and mental health disorders will be conducted. Participants attending specialist neurology clinics at a National UK Children’s Hospital will be randomised to receive guided self-help for common mental health disorders or to a 12-week waiting list control. Participants in the treatment group will receive 10 sessions of guided self-help delivered over the telephone. The waiting list control group will receive the intervention after a waiting period of 12 weeks. The primary outcome measure is reduction in symptoms of mental health disorders. Exclusion criteria are limited to those at significant risk of harm to self or others, the presence of primary mental health disorder other than anxiety, depression or disruptive behaviour (e.g. psychosis, eating disorder, obsessive-compulsive disorder) or intellectual disability at a level meaning potential participants would be unable to access the intervention. The study has ethical approval from the Camden and Islington NHS Research Ethics Committee, registration number 14.LO.1353. Results will be disseminated to patients, the wider public, clinicians and researchers through publication in journals and presentation at conferences. Discussion: This is the first study to investigate guided self-help interventions for mental health problems in children with neurological conditions, a group which is currently under-represented in mental health research. The intervention is modular and adapted from an empirically supported cognitive behavioural treatment. The generalisability and broad inclusion criteria are strengths but may also lead to some weaknesses

    Earth imaging results from Galileo's second encounter

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    The recent flyby of the Galileo spacecraft en route to Jupiter contributes a unique perspective to our view of our home planet. Imaging activities conducted during the second Earth encounter provide an important opportunity to assess new methods and approaches on familiar territory. These include unique multispectral observations, low light-level imaging (searches for aurorae, lightning and artificial lights on the nightside) and experiments with multiple exposure times to extend the effective radiometric resolution and dynamic range of the camera system. Galileo imaging data has the potential to make important contributions to terrestrial remote sensing. This is because the particular set of filters included in the Solid State Imaging system are not presently incorporated in any currently operating Earth-orbiting sensor system. The visible/near-infrared bandpasses of the SSI filters are well suited to remote sensing of geological, glaciological, botanical, and meteorological phenomena. Data from this and the previous Earth encounter may provide an extremely valuable reference point in time for comparison with similar data expected from EOS or other systems in the future, contributing directly to our knowledge of global change. The highest resolution imaging (0.2 km/pixel) during the December, 1992 encounter occurred over the central Andes; a five filter mosaic of visible and near infrared bands displays the remarkable spectral heterogeneity of this geologically diverse region. As Galileo departed the Earth, cooperative imaging with the Near Infrared Mapping Spectrometer (NIMS) instrument targeted Antarctica, Australia, and Indonesia at 1.0 to 2.5 km/pixel resolutions in the early morning local times near the terminator. The Antarctic data are of particular interest, potentially allowing ice grain size mapping using the 889 and 968 nm filters and providing an important means of calibrating the technique for application to the Galilean satellites. As the spacecraft receded further, regional scale imaging provided data which, along with data from the previous encounter, will enable the production of global multispectral mosaics of Earth in each of the SSI filters
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