175 research outputs found

    Open Circuit Resonant (SansEC) Sensor for Composite Damage Detection and Diagnosis in Aircraft Lightning Environments

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    Composite materials are increasingly used in modern aircraft for reducing weight, improving fuel efficiency, and enhancing the overall design, performance, and manufacturability of airborne vehicles. Materials such as fiberglass reinforced composites (FRC) and carbon-fiber-reinforced polymers (CFRP) are being used to great advantage in airframes, wings, engine nacelles, turbine blades, fairings, fuselage and empennage structures, control surfaces and coverings. However, the potential damage from the direct and indirect effects of lightning strikes is of increased concern to aircraft designers and operators. When a lightning strike occurs, the points of attachment and detachment on the aircraft surface must be found by visual inspection, and then assessed for damage by maintenance personnel to ensure continued safe flight operations. In this paper, a new method and system for aircraft in-situ damage detection and diagnosis are presented. The method and system are based on open circuit (SansEC) sensor technology developed at NASA Langley Research Center. SansEC (Sans Electric Connection) sensor technology is a new technical framework for designing, powering, and interrogating sensors to detect damage in composite materials. Damage in composite material is generally associated with a localized change in material permittivity and/or conductivity. These changes are sensed using SansEC. Unique electrical signatures are used for damage detection and diagnosis. NASA LaRC has both experimentally and theoretically demonstrated that SansEC sensors can be effectively used for in-situ composite damage detection

    Computational Electromagnetic Modeling of SansEC(Trade Mark) Sensors

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    This paper describes the preliminary effort to apply computational design tools to aid in the development of an electromagnetic SansEC resonant sensor composite materials damage detection system. The computational methods and models employed on this research problem will evolve in complexity over time and will lead to the development of new computational methods and experimental sensor systems that demonstrate the capability to detect, diagnose, and monitor the damage of composite materials and structures on aerospace vehicles

    Atmospheric Environmental Safety Technologies Project Atmospheric Hazard Safety Mitigation: Lightning and EM Effects Mitigation

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    This viewgraph presentation describes various lightning strike and electromagnetic sensing mitigation technologies to minimize flight safety risks

    Completeness of maternal smoking status recording during pregnancy in United Kingdom primary care data.

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    BACKGROUND: Given the health impacts of smoking during pregnancy and the opportunity for primary healthcare teams to encourage pregnant smokers to quit, our primary aim was to assess the completeness of gestational smoking status recording in primary care data and investigate whether completeness varied with women's characteristics. As a secondary aim we assessed whether completeness of recording varied before and after the introduction of the Quality and Outcomes Framework (QOF). METHODS: In The Health Improvement Network (THIN) database we calculated the proportion of pregnancies ending in live births or stillbirths where there was a recording of maternal smoking status for each year from 2000 to 2009. Logistic regression was used to assess variation in the completeness of maternal smoking recording by maternal characteristics, before and after the introduction of QOF. RESULTS: Women had a record of smoking status during the gestational period in 28% of the 277,552 pregnancies identified. In 2000, smoking status was recorded in 9% of pregnancies, rising to 43% in 2009. Pregnant women from the most deprived group were 17% more likely to have their smoking status recorded than pregnant women from the least deprived group before QOF implementation (OR 1.17, 95% CI 1.10-1.25) and 42% more likely afterwards (OR 1.42, 95% CI 1.37-1.47). A diagnosis of asthma was related to recording of smoking status during pregnancy in both the pre-QOF (OR 1.63, 95% CI 1.53-1.74) and post-QOF periods (OR 2.08, 95% CI 2.02-2.15). There was no association between having a diagnosis of diabetes and recording of smoking status during pregnancy pre-QOF however, post-QOF diagnosis of diabetes was associated with a 12% increase in recording of smoking status (OR 1.12, 95% CI 1.05-1.19). CONCLUSION: Recording of smoking status during pregnancy in primary care data is incomplete though has improved over time, especially after the implementation of the QOF, and varies by maternal characteristics and QOF-incentivised morbidities

    Can primary care data be used to monitor regional smoking prevalence? An analysis of The Health Improvement Network primary care data

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    <p>Abstract</p> <p>Background</p> <p>Accurate and timely regional data on smoking trends allow tobacco control interventions to be targeted at the areas most in need and facilitate the evaluation of such interventions. Electronic primary care databases have the potential to provide a valuable source of such data due to their size, continuity and the availability of socio-demographic data. UK electronic primary care data on smoking prevalence from The Health Improvement Network (THIN) have previously been validated at the national level, but may be less representative at the regional level due to reduced sample sizes. We investigated whether this database provides valid regional data and whether it can be used to compare smoking prevalence in different UK regions.</p> <p>Methods</p> <p>Annual estimates of smoking prevalence by government office region (GOR) from THIN were compared with estimates of smoking prevalence from the General Lifestyle Survey (GLF) from 2000 to 2008.</p> <p>Results</p> <p>For all regions, THIN prevalence data were generally found to be highly comparable with GLF data from 2006 onwards.</p> <p>Conclusions</p> <p>THIN primary care data could be used to monitor regional smoking prevalence and highlight regional differences in smoking in the UK.</p

    Open Circuit Resonant (SansEC) Sensor Technology for Lightning Mitigation and Damage Detection and Diagnosis for Composite Aircraft Applications

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    Traditional methods to protect composite aircraft from lightning strike damage rely on a conductive layer embedded on or within the surface of the aircraft composite skin. This method is effective at preventing major direct effect damage and minimizes indirect effects to aircraft systems from lightning strike attachment, but provides no additional benefit for the added parasitic weight from the conductive layer. When a known lightning strike occurs, the points of attachment and detachment on the aircraft surface are visually inspected and checked for damage by maintenance personnel to ensure continued safe flight operations. A new multi-functional lightning strike protection (LSP) method has been developed to provide aircraft lightning strike protection, damage detection and diagnosis for composite aircraft surfaces. The method incorporates a SansEC sensor array on the aircraft exterior surfaces forming a "Smart skin" surface for aircraft lightning zones certified to withstand strikes up to 100 kiloamperes peak current. SansEC sensors are open-circuit devices comprised of conductive trace spiral patterns sans (without) electrical connections. The SansEC sensor is an electromagnetic resonator having specific resonant parameters (frequency, amplitude, bandwidth & phase) which when electromagnetically coupled with a composite substrate will indicate the electrical impedance of the composite through a change in its resonant response. Any measureable shift in the resonant characteristics can be an indication of damage to the composite caused by a lightning strike or from other means. The SansEC sensor method is intended to diagnose damage for both in-situ health monitoring or ground inspections. In this paper, the theoretical mathematical framework is established for the use of open circuit sensors to perform damage detection and diagnosis on carbon fiber composites. Both computational and experimental analyses were conducted to validate this new method and system for aircraft composite damage detection and diagnosis. Experimental test results on seeded fault damage coupons and computational modeling simulation results are presented. This paper also presents the shielding effectiveness along with the lightning direct effect test results from several different SansEC LSP and baseline protected and unprotected carbon fiber reinforced polymer (CFRP) test panels struck at 40 and 100 kiloamperes following a universal common practice test procedure to enable damage comparisons between SansEC LSP configurations and common practice copper mesh LSP approaches. The SansEC test panels were mounted in a LSP test bed during the lightning test. Electrical, mechanical and thermal parameters were measured during lightning attachment and are presented with post test nondestructive inspection comparisons. The paper provides correlational results between the SansEC sensors computed electric field distribution and the location of the lightning attachment on the sensor trace and visual observations showing the SansEC sensor's affinity for dispersing the lightning attachment

    Surgical management of patent ductus arteriosus in pre-term infants - a british paediatric surveillance study.

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    BACKGROUND: This study aimed to provide UK data describing the incidence of patent ductus arteriosus (PDA) surgery in the neonatal population, including: pre-ligation management, and outcomes until discharge. We used British Paediatric Surveillance Unit (BPSU) methodology; collecting data via questionnaires for preterm neonates undergoing PDA ligation (PDAL) between 1st Sept 2012 - 30th Sept 2013. Infants born less than 37 weeks gestation, who underwent PDAL prior to discharge home, with no other structural cardiac abnormality, were included. Information collected included: patient demographics, pre and post-operative clinical characteristics, pre-operative medical management, post-operative complications and outcome. RESULTS: Over the study, 263 infants underwent PDAL an incidence of 3.07 per 10,000 live births. 88% were born extremely preterm (< 28 weeks) and 60% were male. The commonest reasons for ligation were inability to wean respiratory support (83.7%) and haemodynamically significant PDA (87.8%). Pre-operatively 65.7% received medical therapy. Surgery was performed at a median age of 33 days (range 9-260, IQR 24-48); the corrected age was less than 31 + 6 week in 50.6% babies at PDAL. Most, (90%), of procedures were open ligation; only 9 (3.4%) were catheter occlusions (PDACO). 20.5% of patients had post-operative complications. The 30-day mortality was 3%, with 93.5% surviving to hospital discharge. CONCLUSION: This study showed there was little consensus over medical and surgical management of the PDA or timing of surgery

    Insights into social disparities in smoking prevalence using Mosaic, a novel measure of socioeconomic status: an analysis using a large primary care dataset

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    <p>Abstract</p> <p>Background</p> <p>There are well-established socio-economic differences in the prevalence of smoking in the UK, but conventional socio-economic measures may not capture the range and degree of these associations. We have used a commercial geodemographic profiling system, Mosaic, to explore associations with smoking prevalence in a large primary care dataset and to establish whether this tool provides new insights into socio-economic determinants of smoking.</p> <p>Methods</p> <p>We analysed anonymised data on over 2 million patients from The Health Improvement Network (THIN) database, linked via patients' postcodes to Mosaic classifications (11 groups and 61 types) and quintiles of Townsend Index of Multiple Deprivation. Patients' current smoking status was identified using Read Codes, and logistic regression was used to explore the associations between the available measures of socioeconomic status and smoking prevalence.</p> <p>Results</p> <p>As anticipated, smoking prevalence increased with increasing deprivation according to the Townsend Index (age and sex adjusted OR for highest vs lowest quintile 2.96, 95% CI 2.92-2.99). There were more marked differences in prevalence across Mosaic groups (OR for group G vs group A 4.41, 95% CI 4.33-4.49). Across the 61 Mosaic types, smoking prevalence varied from 8.6% to 42.7%. Mosaic types with high smoking prevalence were characterised by relative deprivation, but also more specifically by single-parent households living in public rented accommodation in areas with little community support, having no access to a car, few qualifications and high TV viewing behaviour.</p> <p>Conclusion</p> <p>Conventional socio-economic measures may underplay social disparities in smoking prevalence. Newer classification systems, such as Mosaic, encompass a wider range of demographic, lifestyle and behaviour data, and are valuable in identifying characteristics of groups of heavy smokers which might be used to tailor cessation interventions.</p

    Evaluation of a novel intervention providing insight into the tobacco industry to prevent the uptake of smoking in school-aged children: a mixed-methods study

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    Objectives: Evidence from the US Truth® campaign suggests that interventions focusing on tobacco industry practices and ethics may be effective in preventing youth smoking uptake. We developed, piloted and evaluated a school-based intervention based on this premise. Methods: Exploratory study Students in Years 7–8 (aged 11–13) in two UK schools received Operation Smoke Storm, comprising three 50-minute classroom-based sessions in Year 7, an accompanying family booklet and a 1-hour classroom-based booster session in Year 8. We compared the risk and odds of ever smoking and susceptibility to smoking in Year 8 students in study schools post-intervention compared with students in control schools. Focus groups and interviews with students, teachers and parents evaluated the acceptability of the intervention. Results: In intervention schools the combined prevalence of ever smoking and susceptibility increased from 18.2% in Year 7 to 33.8% in Year 8. There was no significant difference in the odds of a Year 8 student in an intervention school being an ever smoker or susceptible never smoker compared with controls [adjusted OR 1.28, 95%CI 0.83-1.97, p=0.263] and no significant difference in the odds of ever smoking (aOR 0.82, 95%CI 0.42-1.58, p=0.549). Teachers highlighted differences by academic ability in how well the messages presented were understood. Use of the family component was low but was received positively by parents who engaged with it. Conclusions: Operation Smoke Storm is an acceptable resource for delivering smoking-prevention education but it does not appear to have reduced smoking and susceptibility

    Multi-Layer Wireless Sensor Construct for Use at Electrically-Conductive Material Surfaces

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    A multi-layer wireless sensor construct is provided. The construct includes a first dielectric layer adapted to be attached to a portion of a first surface of an electrically-conductive material. A layer of mu metal is provided on the first dielectric layer. A second dielectric layer is provided on the layer of mu metal. An electrical conductor is provided on the second dielectric layer wherein the second dielectric layer separates the electrical conductor from the layer of mu metal. The electrical conductor has first and second ends and is shaped to form an unconnected open-circuit that, in the presence of a time-varying magnetic field, resonates to generate a harmonic magnetic field response having a frequency, amplitude and bandwidth
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