1,585 research outputs found
A field programmable gate array based Langmuir probe system for measurement of plasma parameters at 500Â kHz in a high-power impulse magnetron sputtering plasma.
By utilizing Field Programmable Gate Arrays in a configuration similar to that of the Mirror Langmuir Probe, it is possible to bias a single probe at three precise voltages in sequence. These voltages can be dynamically adjusted in real-time based on the measured plasma electron temperature to ensure the transition region is always sampled. The first results have been obtained by employing this method and have generated real-time outputs of electron temperature, ion saturation current, and floating potential on a low temperature pulsed-DC magnetron at 500 kHz. These results are in good agreement with the analysis of a conventionally swept Langmuir probe. This probe is designed with the intention of being implemented on MAST-U to aid in the study of exhaust physics and enable further investigation into filamentary behavior. [Abstract copyright: © 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Asian Longhorned Tick
The Asian longhorned tick (Haemophysalis longicorns Neumann; alternative names include Asian longhorned tick, Asian tick, bush tick, New Zealand cattle tick) is a species of hard tick in the family Ixodidae. It is native to eastern China, Japan, the Russian Far East and Korea. It has also established in Australia, New Zealand and several Pacific islands, where it is considered a severe exotic pest of livestock. In late 2017, the United States Department of Agriculture’s National Veterinary Services Laboratories (NVSL) confirmed the presence of the Asian longhorned tick in the United States. These ticks were first identified in New Jersey, but have since been found in archival samples from West Virginia as far back as 2010. The origin of the tick in the US remains unknown. Some possible routes of entry include entering on domestic pets, horses, livestock or humans. The real impact of the introduction of this tick into the US is not clear at this time, but animal health officials are concerned about potential detrimental impacts on livestock and wildlife
Thermal Physiology and Developmental Plasticity of Pigmentation in the Harlequin Bug (Hemiptera: Pentatomidae)
Traits that promote the maintenance of body temperatures within an optimal range provide advantages to ectothermic species. Pigmentation plasticity is found in many insects and enhances thermoregulatory potential as increased melanization can result in greater heat retention. The thermal melanism hypothesis predicts that species with developmental plasticity will have darker pigmentation in colder environments, which can be an important adaptation for temperate species experiencing seasonal variation in climate. The harlequin bug (Murgantia histrionica, Hemiptera: Pentatomidae, Hahn 1834) is a widespread invasive crop pest with variable patterning where developmental plasticity in melanization could affect performance. To investigate the impact of temperature and photoperiod on melanization and size, nymphs were reared under two temperatures and two photoperiods simulating summer and fall seasons. The size and degree of melanization of adults were quantified using digital imagery. To assess the effect of coloration on the amount of heat absorption, we monitored the temperature of adults in a heating experiment. Overall, our results supported the thermal melanism hypothesis and temperature had a comparatively larger effect on coloration and size than photoperiod. When heated, the body temperature of individuals with darker pigmentation increased more relative to the ambient air temperature than individuals with lighter pigmentation. These results suggest that colder temperatures experienced late in the season can induce developmental plasticity for a phenotype that improves thermoregulation in this species. Our work highlights environmental signals and consequences for individual performance due to thermal melanism in a common invasive species, where capacity to respond to changing environments is likely contributing to its spread
Gender equality and girls education: Investigating frameworks, disjunctures and meanings of quality education
The article draws on qualitative educational research across a diversity of low-income countries to examine the gendered inequalities in education as complex, multi-faceted and situated rather than a series of barriers to be overcome through linear input–output processes focused on isolated dimensions of quality. It argues that frameworks for thinking about educational quality often result in analyses of gender inequalities that are fragmented and incomplete. However, by considering education quality more broadly as a terrain of quality it investigates questions of educational transitions, teacher supply and community participation, and develops understandings of how education is experienced by learners and teachers in their gendered lives and their teaching practices. By taking an approach based on theories of human development the article identifies dynamics of power underpinning gender inequalities in the literature and played out in diverse contexts and influenced by social, cultural and historical contexts. The review and discussion indicate that attaining gender equitable quality education requires recognition and understanding of the ways in which inequalities intersect and interrelate in order to seek out multi-faceted strategies that address not only different dimensions of girls’ and women’s lives, but understand gendered relationships and structurally entrenched inequalities between women and men, girls and boys
Ultra-Fast Langmuir Probe in Magnetised Plasma
Conventional Langmuir probes are powerful diagnostics for measuring plasma temperature, ion saturation current, and floating potential and are widely used to diagnose the Scrape-Off Layer (SOL) and divertor of magnetic confinement fusion devices. Plasma in these regions is known to contain fast moving filamentary structures that require highly resolved measurements to fully characterise which are beyond what single and triple probes can provide
High speed synchrotron X-ray imaging studies of the ultrasound shockwave and enhanced flow during metal solidification processes
The highly dynamic behaviour of ultrasonic bubble implosion in liquid metal, the multiphase liquid metal flow containing bubbles and particles, and the interaction between ultrasonic waves and semisolid phases during solidification of metal were studied in situ using the complementary ultrafast and high speed synchrotron X-ray imaging facilities housed respectively at the Advanced Photon Source, Argonne National Laboratory, US, and Diamond Light Source, UK. Real-time ultrafast X-ray imaging of 135,780 frames per second (fps) revealed that ultrasonic bubble implosion in a liquid Bi-8 wt. %Zn alloy can occur in a single wave period (30 kHz), and the effective region affected by the shockwave at implosion was 3.5 times the original bubble diameter. Furthermore, ultrasound bubbles in liquid metal move faster than the primary particles, and the velocity of bubbles is 70 ~ 100% higher than that of the primary particles present in the same locations close to the sonotrode. Ultrasound waves can very effectively create a strong swirling flow in a semisolid melt in less than one second. The energetic flow can detach solid particles from the liquid-solid interface and redistribute them back into the bulk liquid very effectively
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