884 research outputs found

    Containerless preparation of advanced optical glasses: Experiment 77F095

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    Containerless processing of optical glasses was studied in preparation for space shuttle MEA flight experiments. Ground based investigation, experiment/hardware coordination activities and development of flight experiment and sample characterization plans were investigated. In the ground based investigation over 100 candidate glass materials for space processing were screened and promising compositions were identified. The system of Nb2O5-TiO2-CaO was found to be very rich with containerless glass compositions and as extensive number of the oxides combinations were tried resulting in a glass formation ternary phase diagram. The frequent occurrence of glass formation by containerless processing among the compositions for which no glass formations were previously reported indicated the possibility and an advantage of containerless processing in a terrestrial environment

    SPAR 6 experiment report containerless processing of glass experiment 74-42

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    Pertinent portions of the ground based research are described, including experiments leading to the selection of the flight sample composition: a silica modified gallia-calcia glass. Included are details of the preparation of an approximately .25 in diameter flight sample

    Photoheliograph study for the Apollo telescope mount

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    Photoheliograph study for Apollo telescope moun

    Experiences of social isolation and loneliness in middle-aged and older autistic adults

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    Background: Young autistic people often experience social isolation and loneliness. Despite social isolation and loneliness increasing in later life in non-autistic populations, few studies have examined whether middle-aged and older autistic adults are at an increased likelihood of these experiences. Methods: 428 adults (51% female, autistic n=265) aged 40-93 (mean age=60.5 years) completed online questionnaires related to their experiences of social isolation, loneliness, and mental health. Group differences and associations were examined. Results: The autistic group were more socially isolated and lonelier than the non-autistic group. While there were few gender differences in social isolation, women reported being lonelier than men in both groups, including when controlling for age and mental health. While social isolation increased with age in both groups, loneliness only increased with age in the autistic group. For both social isolation and loneliness, the associations with age were significantly stronger in men than women. Conclusions: These findings suggest that autistic adults may be particularly susceptible to social isolation and loneliness in midlife and older age. While autistic women reported being lonelier, autistic men may be at greater risk of increasing social isolation and loneliness with older age. This study highlights the need for evidence-based interventions to address social isolation and to reduce loneliness for autistic people as they age

    Effects of Frontal Transcranial Direct Current Stimulation on Emotional State and Processing in Healthy Humans

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    The prefrontal cortex is involved in mood and emotional processing. In patients suffering from depression, the left dorsolateral prefrontal cortex (DLPFC) is hypoactive, while activity of the right DLPFC is enhanced. Counterbalancing these pathological excitability alterations by repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) improves mood in these patients. In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed. We aimed to evaluate the effects of prefrontal tDCS on emotion and emotion-related cognitive processing in healthy humans. In a first study, we administered excitability-enhancing anodal, excitability-diminishing cathodal, and placebo tDCS to the left DLPFC, combined with antagonistic stimulation of the right frontopolar cortex, and tested acute emotional changes by an adjective checklist. Subjective emotions were not influenced by tDCS. Emotional face identification, however, which was explored in a second experiment, was subtly improved by a tDCS-driven excitability modulation of the prefrontal cortex, markedly by anodal tDCS of the left DLPFC for positive emotional content. We conclude that tDCS of the prefrontal cortex improves emotion processing in healthy subjects, but does not influence subjective emotional state

    Using Performance Forecasting to Accelerate Elasticity

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    Cloud computing facilitates dynamic resource provisioning. The automation of resource management, known as elasticity, has been subject to much research. In this context, monitoring of a running service plays a crucial role, and adjustments are made when certain thresholds are crossed. On such occasions, it is common practice to simply add or remove resources. In this paper we investigate how we can predict the performance of a service to dynamically adjust allocated resources based on predictions. In other words, instead of “repairing” because a threshold has been crossed, we attempt to stay ahead and allocate an optimized amount of resources in advance. To do so, we need to have accurate predictive models that are based on workloads. We present our approach, based on the Universal Scalability Law, and discuss initial experiments
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