837 research outputs found

    Voltage driven, local, and efficient excitation of nitrogen-vacancy centers in diamond

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    Magnetic sensing technology has found widespread application in industries as diverse as transportation, medicine, and resource exploration. Such use cases often require highly sensitive instruments to measure the extremely small magnetic fields involved, relying on difficult to integrate Superconducting Quantum Interference Device (SQUID) and Spin-Exchange Relaxation Free (SERF) magnetometers. A potential alternative, nitrogen vacancy (NV) centers in diamond, has shown great potential as a high sensitivity and high resolution magnetic sensor capable of operating in an unshielded, room-temperature environment. Transitioning NV center based sensors into practical devices, however, is impeded by the need for high power RF excitation to manipulate them. Here we report an advance that combines two different physical phenomena to enable a highly efficient excitation of the NV centers: magnetoelastic drive of ferromagnetic resonance (FMR) and NV-magnon coupling. Our work demonstrates a new pathway to combine acoustics and magnonics that enables highly energy efficient and local excitation of NV centers without the need for any external RF excitation, and thus could lead to completely integrated, on-chip, atomic sensors.Comment: Fixed an issue with the display of figure

    Judging the morality of utilitarian actions: How poor utilitarian accessibility makes judges irrational.

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    Is it acceptable and moral to sacrifice a few people's lives to save many others? Research on moral dilemmas in psychology, experimental philosophy, and neuropsychology has shown that respondents judge utilitarian personal moral actions (footbridge dilemma) as less appropriate than equivalent utilitarian impersonal moral actions (trolley dilemma). Accordingly, theorists (e.g., Greene et al., 2001) have argued that judgments of appropriateness in personal moral dilemmas are more emotionally salient and cognitively demanding (taking more time to be rational) than impersonal moral dilemmas. Our novel findings show an effect of psychological accessibility (driven by partial contextual information; Kahneman, 2003) on utilitarian moral behavior and response time for rational choices. Enhanced accessibility of utilitarian outcomes through comprehensive information about moral actions and consequences boosted utility maximization in moral choices, with rational choices taking less time. Moreover, our result suggests that previous results indicating emotional interference, with rational choices taking more time to make, may have been artifacts of presenting partial information

    Impact of returning scientific cruises and prolonged on-site presence on litter abundance at the deep-sea nodule fields in the Peru Basin

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    Marine litter can be found along coasts, continental shelves and slopes, down into the abyss. The absence of light, low temperatures and low energy regimes characterising the deeper habitats ensure the persistence of litter over time. Therefore, manmade items within the deep sea will likely accumulate to increasing quantities. Here we report the litter abundance encountered at the Pacific abyssal nodule fields from the Peru Basin at 4150 m depth. An average density of 2.67 litter items/ha was observed. Litter composed of plastic was the most abundant followed by metal and glass. At least 58 % of the items observed could be linked to the research expeditions conducted in the area and appeared to be mostly accidental disposals from ships. The data gathered was used to address temporal trends in litter abundance as well as the impact of human on-site presence and return cruises in the context of future deep-sea mining efforts

    Residential building and occupant vulnerability to pyroclastic density currents in explosive eruptions

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    International audienceA major hazard during the eruption of explosive volcanoes is the formation of pyroclastic density currents (PDCs). Casualties and physical building damage from PDCs are caused by the temperature, pressure, and particle load of the flow. This paper examines the vulnerability of buildings and occupants to the forces imposed by PDCs along with associated infiltration of PDC particle and gas mixtures into an intact building. New studies are presented of building and occupant vulnerability with respect to temperature, pressure, and ash concentration. Initial mitigation recommendations are provided

    Archaeological Geophysical Prospection in Peatland Environments: case studies and suggestions for future practice

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    Peatland environments, in contrast to ‘dry-land’ sites, preserve organic material, including anthropogenic objects, because they are anaerobic, and are therefore of great importance to archaeology. Peat also preserves macro- and micro- paleoenvironmental evidence and is the primary resource for understanding past climates and ecology. Archaeological sites often lie within or at the base of wet, deep, homogenous peat rendering them invisible to surface observers. As a result, they most often c..

    Capoeira for beginners: self-benefit for, and community action by, new Capoeiristas

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    Capoeira could be defined as a Brazilian martial art and game to be played. This research explored how capoeira play might be considered to facilitate connectedness amongst newly-recruited persons, plus any other ramifications of capoeira involvement. A beginners’ course of capoeira was provided to participants, free of charge, in an English city in the West Midlands—new capoeiristas in a new venue for capoeira. Researchers attended classes to collect/construct overt non-participant observation data. In addition, semi-structured interviews were undertaken with the new capoeiristas post-course. This article explores researchers’ observation fieldnotes and interviewees’ narratives. These qualitative data-driven debates include the concepts: self, identity, escapism, multiparty endeavour, community, temporality, enjoyment, and transcending boundaries. Capoeira is theorised in a fresh manner that highlights social benefits of capoeira—for example as an enjoyable and supportive group endeavour which includes elements of social play and community-building—plus benefits for self that can transcend the boundaries of the class. Findings highlight how capoeira can be considered an inherently multiparty endeavour whereby social actors form, and experience, a community in order to embrace capoeira play. Data suggest capoeira can facilitate group playfulness, joviality, and laughter. Further, capoeiristas can enact and experience—some mode of—escapism via capoeira, whereby new place and pursuit can facilitate hedonistic diversion from the mundane. Capoeira appears to provide adventure and liberation into a relatively unburdened part of, or place in, social life. Corporeal and discursive boundary-empowerment can also be experienced by capoeiristas, fostering positive identity work in the wider world. Capoeira can be argued to facilitate mutuality (e.g. community experience and group work) and egoism (e.g. an individual's identity work) concurrently. This research suggests that modified capoeira for beginners can be beneficial for both the new capoeiristas themselves and for positive community action during and beyond class
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