7 research outputs found

    Lawson criterion for ignition exceeded in an inertial fusion experiment

    Get PDF
    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    Mapping a conservation research network to the Sustainable Development Goals

    Get PDF
    The United Nations Sustainable Development Goals (SDGs) provide a global blueprint to end extreme poverty, reduce inequality, and protect the planet. Progress toward these goals is falling short. Achieving the SDGs requires coordination among government, private industry, and nongovernmental organizations to align the actions of multiple sectors with SDG targets. Adapting an approach used by industry sectors, we mapped the Smithsonian Institution Working Land and Seascapes network to the SDGs. The network of programs aims to foster healthy and productive ecosystems through collaborations with diverse stakeholders. Across the network, we identified clear and measurable contributions to 16 of the 17 SDGs and specifically mapped past and current activities to 76 of the 169 targets, thereby demonstrating how conservation actions can contribute to achieving the SDGs, beyond SDGs 14 and 15. We also identified the need for clear results chain and greater capacity to achieve the SDGs and then provide examples of how different sectors can increase complementarity of their actions. By mapping activities to the SDGs, different sectors can increase alignment and strengthen collective contributions towards common global goals

    Pollinator effectiveness and fruit set in common ivy, Hedera helix (Araliaceae)

    No full text
    Flowers of common ivy (Hedera helix L.) provide late season pollen and nectar for several insect groups, and its fruits are a winter and spring food source for frugivorous birds. Ivy benefits from insect pollination in order to set fruit, but it is unknown which flower-visiting insects are the most effective pollinators. Our observations suggest that Vespula wasps are potentially the most effective pollinators since they were frequent visitors, had relatively fast foraging rates, carried large numbers of pollen grains on their bodies and had the highest ‘Pollination potential PP index’ score (a measure of pollinator effectiveness) of all the insect groups examined. There was also a positive linear relationship between the proportion of ivy flowers that set fruit and wasp foraging activity in 0.5 m2 quadrats. Visits by Vespula wasps may therefore be important for ensuring a supply of ivy fruits for birds

    Maligne Hodentumoren

    No full text
    corecore