528 research outputs found

    Magnetic local time dependency on cusp ion velocity dispersions in the mid-altitude cusp

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    Observations of cusp ion velocity dispersions made by the TIMAS instrument on the Polar spacecraft in the mid-altitude cusp during intervals of northward interplanetary magnetic field (IMF) reveal a clear ordering with magnetic local time (MLT). Between 1100 and 1300 MLT the injected ion velocity increased with invariant latitude for 78% of the cusp crossings, between 0900 and 1100 MLT this percentage reduced to 35% and between 1300 and 1500 MLT the percentage reduced to 57%. In contrast similar observations made during intervals of southward IMF revealed no MLT dependency. Between 0900 and 1500 MLT the injected ion velocity increased with invariant latitude for only 17% of the observed cusp crossings. We suggest that the difference in the MLT dependency between northward and southward IMF can be best explained by the different characteristics of polar convection patterns for sub-solar and lobe reconnection

    Automation of optimal laminate design

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    Composite laminates are in widespread use in the aerospace industry. As well as sa tisfying strength and stiffness criteria, the final laminate design has to be manufacturable in terms of compatibility between adjacent panels, thus introducing conflicting constraints on the allowed laminate stacking sequences. An attempt to automate the laminate design process is described. The method uses a mixture of a genetic algorithm and heuristics to satisfy the various design and manufacturing constraints. Multiple zones are allowed, where each zone defines a panel together with a set of applied loads. Guide laminates and a blending methodology allow each zone to share common plies. This creates ply continuity across the structure and avoids the scenario seen in other laminate optimisation tools where each optimised zone contains unrelated laminates which are not practical from a manufacturing perspective

    Sugar maple (Acer saccharum March.) growth is influenced by close conspecifics and skid trait proximity following selection harvest

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    In this study, we quantified the effects of local neighbourhood competition, light availability, and proximity to skid trails on the growth of sugar maple (Acer saccharum Marsh.) trees following selection harvest. We hypothesized that growth would increase with decreasing competition and increasing light availability, but that proximity to skid trails would negatively affect growth. A total of 300 sugar maples were sampled 10 years after selection harvesting in 18 stands in Témiscamingue (Québec, Canada). Detailed tree and skid trail maps were obtained in one 0.4 ha plot per stand. Square-root transformed radial growth data were fitted to a linear mixed model that included tree diameter, crown position, a neighbourhood competition index, light availability (estimated using the SORTIE light model), and distance to the nearest skid trail as explanatory variables. We considered various distance-dependent or -independent indices based on neighbourhood radii ranging from 6 to 12 m. The competition index that provided the best fit to the data was a distance-dependent index computed in a 6 m search radius, but a\ud distance-independent version of the competition index provided an almost equivalent fit to data. Models corresponding to all combinations of main effects were fit to data using maximum likelihood, and weighted averages of parameter estimates were obtained usingmultimodel inference. All predictors had\ud an influence on growth, with the exception of light. Radial growth decreased with increasing tree diameter, level of competition and proximity to skid trails, and varied among crown positions with trees in suppressed and intermediate positions having lower growth rates than codominants and dominants. Our results indicate that in selection managed stands, the radial growth of sugarmaple trees depends on\ud competition from close (6 m) conspecific neighbours, and is still affected by proximity to skid trails 10 years after harvesting. Such results underscore the importance of minimizing the extent of skid trail networks by careful pre-harvest planning of trail layout. We also conclude that the impact of heterogeneity among individual-tree neighbourhoods, such as those resulting from alternative spatial patterns of harvest, can usefully be integrated into models of post-harvest tree growth

    Beliefs, benefits, barriers, attitude, intake and knowledge about peanuts and tree nuts among WIC participants in eastern North Carolina

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    The objective of this study was to assess beliefs (e.g. advantages, disadvantages, benefits, barriers) and knowledge about eating peanuts and tree nuts. Personal interviews based on the Theory of Planned Behavior were conducted to elicit beliefs about eating nuts. Then, a cross-sectional survey was administered to WIC participants from one county in North Carolina. One-hundred-twenty-four WIC participants (mean (SD) age=28.39 (8.09) completed the study. Most were Caucasian (51.6%) females (96%). About one third believed that eating nuts may help to lower cholesterol level. However, only about one forth believed that nuts can lower a risk of a heart attack or diabetes. More than one third believed that eating nuts will cause weight gain. The knowledge of respondents' about nutrient content of nuts was low with correct answers to most questions about 20% or below. The mean (SD) positive attitude, negative attitude, benefits and barriers scores, based on a range from 1 to 5, were 2.53 (0.91), 3.25 (0.89), 2.97 (0.85) and 2.90 (0.76), respectively. WIC participants' beliefs regarding the health effects of nuts are inconsistent with the most recent research findings. They are in a need to education about benefits of eating nuts

    Model insights into energetic photoelectrons measured at Mars by MAVEN

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    Photoelectrons are important for heating, ionization, and airglow production in planetary atmospheres. Measured electron fluxes provide insight into the sources and sinks of energy in the Martian upper atmosphere. The Solar Wind Electron Analyzer instrument on board the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft measured photoelectrons including Auger electrons with 500 eV energies. A two-stream electron transport code was used to interpret the observations, including Auger electrons associated with K shell ionization of carbon, oxygen, and nitrogen. It explains the processes that control the photoelectron spectrum, such as the solar irradiance at different wavelengths, external electron fluxes from the Martian magnetosheath or tail, and the structure of the upper atmosphere (e.g., the thermal electron density). Our understanding of the complex processes related to the conversion of solar irradiances to thermal energy in the Martian ionosphere will be advanced by model comparisons with measurements of suprathermal electrons by MAVEN

    The electric wind of Venus: A global and persistent "polar wind"-like ambipolar electric field sufficient for the direct escape of heavy ionospheric ions

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    Understanding what processes govern atmospheric escape and the loss of planetary water is of paramount importance for understanding how life in the universe can exist. One mechanism thought to be important at all planets is an “ambipolar” electric field that helps ions overcome gravity. We report the discovery and first quantitative extraterrestrial measurements of such a field at the planet Venus. Unexpectedly, despite comparable gravity, we show the field to be five times stronger than in Earth's similar ionosphere. Contrary to our understanding, Venus would still lose heavy ions (including oxygen and all water-group species) to space, even if there were no stripping by the solar wind. We therefore find that it is possible for planets to lose heavy ions to space entirely through electric forces in their ionospheres and such an “electric wind” must be considered when studying the evolution and potential habitability of any planet in any star system

    PENGARUH KUANTITAS LAYANAN DAN KEPERCAYAAN TERHADAP KEPUASAN NASABAH KREDIT MIKRO PADA BANK PT. BTPN ARGAMAKMUR

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    The purpose of this research were the impact of service quality toward :ustomer satisfaction at BTPN Bank of Argamalcnur Branch, 2J Analyze the impact of irust toward customer satisfaction at BTPN Bank of Argamakmur Branch, 3) Analyze rhe impact of service quality and trust toward customer satisfaction at BTPN Bank of Argamakmur Branch, 4) Identified the variable that had dominance impact toward customer satisfaction at BTPN Bank of Argamakmur Branch. Purpose sampling method ',vas used on this research. The numbers of sampling were 155 respondents. Multiple regression analysis was used as research method on this study. The result of study can be summaries: 1) There was significant impact of service quality toward customer satisfaction at BTPN Bank of Argamakmur Branch with the value of coefficient was 0,467; 2J There was significant impact of tn-rst toward customer satisfaction at BTPN Bank of Argamakmur Branch with the value of coefficient was 0,382,3) There was significant impact of service quality and trust toward customer satisfaction at BTPN Bank of Argamalnnur Branch with the value of inpact was 67 ,2o/o and 32,8o/a of the rest was influence by other factors, 4) Based on the study found that the service quality had more strong impact to customer satisfaction rather than of trust at BTPN Bank of Argamakmur Branch
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