1,040 research outputs found

    Current status of metric reduction of (passive) scanner data

    Get PDF
    The extraction of metric information from scanner (particularly multispectral) data is presented. Data from both aircraft and spacecraft; singly scanned areas and areas with multiple coverage; various mathematical models used up to the present time; and published numerical results are considered. Future trends are also discussed

    Sensor failure detection system

    Get PDF
    Advanced concepts for detecting, isolating, and accommodating sensor failures were studied to determine their applicability to the gas turbine control problem. Five concepts were formulated based upon such techniques as Kalman filters and a screening process led to the selection of one advanced concept for further evaluation. The selected advanced concept uses a Kalman filter to generate residuals, a weighted sum square residuals technique to detect soft failures, likelihood ratio testing of a bank of Kalman filters for isolation, and reconfiguring of the normal mode Kalman filter by eliminating the failed input to accommodate the failure. The advanced concept was compared to a baseline parameter synthesis technique. The advanced concept was shown to be a viable concept for detecting, isolating, and accommodating sensor failures for the gas turbine applications

    NASA Desert RATS 2011 Education Pilot Project and Classroom Activities

    Get PDF
    The National Aeronautics and Space Administration's (NASA's) Desert Research and Technology Studies (Desert RATS) is a multi-year series of tests of hardware and operations carried out annually in the high desert of Arizona, as an analog to future exploration activities beyond low Earth orbit [1]. For the past several years, these tests have occurred in the San Francisco Volcanic Field, north of Flagstaff. For the 2011 Desert RATS season, the Exploration Systems Mission Directorate (ESMD) at NASA headquarters provided support to develop an education pilot project that would include student activities to parallel the Desert RATS mission planning and exploration activities in the classroom, and educator training sessions. The development of the pilot project was a joint effort between the NASA Johnson Space Center (JSC) Astromaterials Research and Exploration Science (ARES) Directorate and the Aerospace Education Services Project (AESP), managed at Penn State University

    Effectiveness of a social support intervention on infant feeding practices : randomised controlled trial

    Get PDF
    Background: To assess whether monthly home visits from trained volunteers could improve infant feeding practices at age 12 months, a randomised controlled trial was carried out in two disadvantaged inner city London boroughs. Methods: Women attending baby clinics with their infants (312) were randomised to receive monthly home visits from trained volunteers over a 9-month period (intervention group) or standard professional care only (control group). The primary outcome was vitamin C intakes from fruit. Secondary outcomes included selected macro and micro-nutrients, infant feeding habits, supine length and weight. Data were collected at baseline when infants were aged approximately 10 weeks, and subsequently when the child was 12 and 18 months old. Results: Two-hundred and twelve women (68%) completed the trial. At both follow-up points no significant differences were found between the groups for vitamin C intakes from fruit or other nutrients. At first follow-up, however, infants in the intervention group were significantly less likely to be given goats’ or soya milks, and were more likely to have three solid meals per day. At the second follow-up, intervention group children were significantly less likely to be still using a bottle. At both follow-up points, intervention group children also consumed significantly more specific fruit and vegetables. Conclusions: Home visits from trained volunteers had no significant effect on nutrient intakes but did promote some other recommended infant feeding practices

    From discovery to scale-up: alpha-lipoic acid : nicotinamide co-crystals in a continuous oscillatory baffled crystalliser

    Get PDF
    The crystalline nutritional supplement alpha-lipoic acid degrades rapidly on exposure to temperatures above its melting point 65 degrees C and to light. A small-scale experimental co-crystal screen has produced three novel co-crystals of alpha-lipoic acid that each display enhanced thermal stability and differences in aqueous solubilities compared to alpha-lipoic acid. In each case, the initial screening procedure produced tens of milligrams of material enabling initial identification, characterisation and crystal structure determination. The structure of the alpha-lipoic acid : nicotinamide co-crystal was determined by single crystal X-ray diffraction and used for subsequent phase identification. Scale-up of the co-crystallisation process of alpha-lipoic acid with nicotinamide was then investigated in a continuous oscillatory baffled crystalliser. Over 1 kg of solid co-crystals was produced using a continuous crystallisation process in a continuous oscillatory baffled crystalliser at a throughput of 350 g h-1 yielding a purity of 99% demonstrating this as an effective route to rapid scale-up of a novel co-crystal system

    From discovery to scale-up: alpha-lipoic acid : nicotinamide co-crystals in a continuous oscillatory baffled crystalliser

    Get PDF
    The crystalline nutritional supplement alpha-lipoic acid degrades rapidly on exposure to temperatures above its melting point 65 degrees C and to light. A small-scale experimental co-crystal screen has produced three novel co-crystals of alpha-lipoic acid that each display enhanced thermal stability and differences in aqueous solubilities compared to alpha-lipoic acid. In each case, the initial screening procedure produced tens of milligrams of material enabling initial identification, characterisation and crystal structure determination. The structure of the alpha-lipoic acid : nicotinamide co-crystal was determined by single crystal X-ray diffraction and used for subsequent phase identification. Scale-up of the co-crystallisation process of alpha-lipoic acid with nicotinamide was then investigated in a continuous oscillatory baffled crystalliser. Over 1 kg of solid co-crystals was produced using a continuous crystallisation process in a continuous oscillatory baffled crystalliser at a throughput of 350 g h-1 yielding a purity of 99% demonstrating this as an effective route to rapid scale-up of a novel co-crystal system

    How old is the Tasmanian cultural landscape? a test of landscape openness using quantitative land-cover reconstructions

    Get PDF
    Aim: To test competing hypotheses about the timing and extent of Holocene landscape opening using pollen-based quantitative land-cover estimates. Location: Dove Lake, Tasmanian Wilderness World Heritage Area, Australia. Methods: Fossil pollen data were incorporated into pollen dispersal models and corrected for differences in pollen productivity among key plant taxa. Mechanistic models (REVEALS-Regional Estimates of VEgetation Abundance from Large Sites) employing different models for pollen dispersal (Gaussian plume and Lagrangian stochastic models) were evaluated and applied in the Southern Hemisphere for the first time. Results: Validation of the REVEALS model with vegetation cover data suggests an overall better performance of the Lagrangian stochastic model. Regional land-cover estimates for forest and non-forest plant taxa show persistent landscape openness throughout the Holocene (average landscape openness similar to 50%). Gymnoschoenus sphaerocephalus, an indicator of moorland vegetation, shows higher values during the early Holocene (11.7-9 ka) and declines slightly through the mid-Holocene (9-4.5 ka) during a phase of partial landscape afforestation. Rain forest cover reduced (from similar to 40% to similar to 20%) during the period between 4.2-3.5 ka. Main conclusions: Pollen percentages severely under-represent landscape openness in western Tasmania and this bias has fostered an over-estimation of Holocene forest cover from pollen data. Treeless vegetation dominated Holocene landscapes of the Dove Lake area, allowing us to reject models of landscape evolution that invoke late-Holocene replacement of a rain forest-dominated landscape by moorland. Instead, we confirm a model of Late Pleistocene inheritance of open vegetation. Rapid forest decline occurred after c.4 ka, likely in response to regional moisture decline.Australian Research Council; AINSE AWARD [ALNGRA16024]; AINSE PGRA scholarship [12039]info:eu-repo/semantics/publishedVersio

    Facial lesions in piglets with intact or grinded teeth

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Piglets are born with eight sharp teeth that during nursing can cause facial lesions on littermates and teat lesions on the sow. Teeth grinding in piglets is therefore often practiced to reduce these lesions. The aim of this study was to assess the consequences of grinding piglet teeth in regard to the occurrence of lesions.</p> <p>In this study the piglets' teeth were grinded in 28 litters, and in 36 litters the piglets' teeth were kept intact. Twice, one time during the first week and one time during the second week after birth facial lesions of the piglets were scored and the teats of the sows were examined for lesions. The facial lesion score accounted for the amount and severity of lesions. The individual observations on piglets in the litter were synthesized in a litter facial lesion score.</p> <p>Findings</p> <p>69.8% and 43.5% of the piglets had facial lesions in week 1 and week 2 respectively. The effect of treatment was not significant on litter facial lesion score. The litter facial lesion score was higher in week 1 than in week 2 (<it>p </it>< 0.001) and higher in large litters (<it>p </it>= 0.003) than in small litters. Mortality between week 1 and week 2 was higher in litters with intact teeth (<it>p </it>= 0.02). Sow teat lesions only occurred if litters had intact teeth.</p> <p>Conclusions</p> <p>According to our results teeth grinding is only justifiable in large litters.</p
    • …
    corecore