1,771 research outputs found

    Charged-particle orbits near a magnetic null point

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    An approximate analytical expression is obtained for the orbits of a charged particle moving in a cusp magnetic field. The particle orbits pass close to or through a region of zero magnetic field before being reflected in regions where the magnetic field is strong. Comparison with numerically evaluated orbits shows that the analytical formula is surprisingly good and captures all the main features of the particle motion. A map describing the long-time behaviour of such orbits is obtained

    Postabortion contraception

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    The European Society of Contraception Expert Group on Abor tion identified as one of its priorities to disseminate up-to-date evidence-based information on postabortion contraception to healthcare providers. A concise communication was produced which summarises the latest research in an easy-to-read format suitable for busy clinicians. Information about individual methods is presented in boxes for ease of reference

    Field assisted processing of 3D printed ceramics

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    Advanced ceramic products for highly demanding applications in electronics, energy, healthcare and defence sectors require densification/sintering, a high temperature process (~1000–2000oC) that in industry can take days. The amount of energy needed, and CO2 emitted, is therefore very significant. Conventional processing of these functional devices/components are often plagued by interfacial issues, unwanted grain growth and limitations of co-firing dissimilar materials. Thus, rapid and efficient sintering methods such as SPS, Microwave Assisted Sintering (MAS) and Flash Sintering (FS) are continuously being developed. These approaches referred as Field Assisted Sintering Techniques (FAST) use an external field that was demonstrated to have a positive effect on densification. For example, the FS method, for reasons that are far from fully understood, has yielded full densification in very short periods (5 s) at very low furnace temperatures (850oC) for zirconia, and at a surprisingly low temperature of 325oC for Co2MnO4 spinel ceramics. The associated time and energy advantage is estimated to be staggering, as well as the ability to tailor the microstructure. In this talk, we will have a closer look at MAS and FS methods– one a well-established and the other a newly emerging densification method. The MAS method can be suitable for the processing of various simple and complex shaped engineering components, the early use of FS method was restricted to dog-bone shaped ceramic specimens – that are both difficult to make and do not have much industrial applicability. However, the recent developments have demonstrated that FS can also be used to sinter different sample shapes. We investigated the feasibility of sintering of 3D printed ultra-low loss 5G microwave dielectrics, YSZ/ZTA biomedical components using MS and FS methods along with measurements of shrinkage and thermal mapping. This talk will review these developments on FS along with the operative mechanisms in comparison with MAS

    Johnson Space Center's Solar and Wind-Based Renewable Energy System

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    The NASA Johnson Space Center (JSC) in Houston, Texas has a Sustainability Partnership team that seeks ways for earth-based sustainability practices to also benefit space exploration research. A renewable energy gathering system was installed in 2007 at the JSC Child Care Center (CCC) which also offers a potential test bed for space exploration power generation and remote monitoring and control concepts. The system comprises: 1) several different types of photovoltaic panels (29 kW), 2) two wind-turbines (3.6 kW total), and 3) one roof-mounted solar thermal water heater and tank. A tie to the JSC local electrical grid was provided to accommodate excess power. The total first year electrical energy production was 53 megawatt-hours. A web-based real-time metering system collects and reports system performance and weather data. Improvements in areas of the CCC that were detected during subsequent energy analyses and some concepts for future efforts are also presented

    Mapping a nation’s landslides: a novel multi-stage methodology

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    Through combining new technologies and traditional mapping techniques, the British Geological Survey (BGS) has developed a novel, multi-stage methodology for landslide mapping. 3-D aerial photograph interpretation, variable-perspective 3-D topographic visualisation and field mapping with digital data capture are being used to map the UK’s landslides. The resulting ESRI ArcGIS polygons are published on BGS 1:50,000 geological maps and as digital data products. Data collected during mapping are also uploaded directly into the National Landslides Database maintaining a systematic, nationally-uniform landslide inventory. Repeat monitoring of selected landslides using terrestrial LIDAR and dGPS allows the database to be frequently updated and the proactive Landslide Response Team means that new landslide events can be mapped within days, if not hours, of their occurrence. The long-term aim is to apply this methodology throughout the UK, providing a wealth of data for scientific research and hazard assessment. This methodology is also suitable for application in an international context

    Differences in digital health literacy and future anxiety between health care and other university students in England during the COVID-19 pandemic.

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    Background: This study investigates university students' digital health literacy and web-based information-seeking behaviours during the early stages of the COVID-19 pandemic in England. It compares undergraduate and postgraduate students in non-health related subjects with health care students, many of whom were preparing for, or working in, frontline roles. The survey was conducted as part of a wider study by the COVID-HL research consortium. Methods: A cross-sectional study was conducted among n=691 university students aged ≥18 years from 25 universities across England using an adapted digital survey developed by COVID-HL. Data were collected regarding sociodemographic characteristics and specific measures drawn from the Future Anxiety Scale and the Digital Health Literacy Instrument (DHLI). These had been adapted for use in an English setting and to the specific context of the COVID-19 pandemic. Other data collected included students’ anxiety or worries about the future using the Dark Future Scale as well as behaviours in online information-seeking. Data were analysed using correlations to test for relationships between constructs and also between group comparisons to test for differences between students studying health and non-health related subjects. Results: Across digital health literacy dimensions, there was no significant difference between students studying health-related subjects and other students. Health care students did report greater difficulties in relation to how to behave online. They also relied less on public body sources for information about the pandemic. A significant difference was found between the two student populations in relation to their anxiety about the future with health care students reporting fewer fears about the future. Conclusions: Although digital health literacy is well developed in university students, a significant proportion of students still face difficulties with evaluating online information which may frustrate public health efforts. This could be addressed by ensuring health students’ curriculum in particular encompasses digital health literac
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