The Experts below are selected from a list of 130116 Experts worldwide ranked by ideXlab platform

Rendong Nan - One of the best experts on this subject based on the ideXlab platform.

  • the five hundred meter aperture spherical radio telescope fast project
    International Journal of Modern Physics D, 2011
    Co-Authors: Rendong Nan, Chengjin Jin, Qiming Wang, Lichun Zhu, Wenbai Zhu, Haiyan Zhang, Youling Yue, Lei Qian
    Abstract:

    Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega-science project to build the largest single dish radio telescope in the world. Its innovative Engineering Concept and design pave a new road to realize a huge single dish in the most effective way. FAST also represents Chinese contribution in the international efforts to build the square kilometer array (SKA). Being the most sensitive single dish radio telescope, FAST will enable astronomers to jump-start many science goals, such as surveying the neutral hydrogen in the Milky Way and other galaxies, detecting faint pulsars, looking for the first shining stars, hearing the possible signals from other civilizations, etc. The idea of sitting a large spherical dish in a karst depression is rooted in Arecibo telescope. FAST is an Arecibo-type antenna with three outstanding aspects: the karst depression used as the site, which is large to host the 500-meter telescope and deep to allow a zenith angle of 40 degrees; the active main ref...

  • five hundred meter aperture spherical radio telescope fast
    Science China-physics Mechanics & Astronomy, 2006
    Co-Authors: Rendong Nan
    Abstract:

    Five hundred meter aperture spherical radio telescope (FAST) will be the largest radio telescope in the world. The innovative Engineering Concept and design pave a new road to realizing a huge single dish in the most effective way. Three outstanding features of the telescope are the unique karst depressions as the sites, the active main reflector which corrects spherical aberration on the ground to achieve full polarization and a wide band without involving a complex feed system, and the light focus cabin driven by cables and servomechanism plus a parallel robot as secondary adjustable system to carry the most precise parts of the receivers. Being the most sensitive radio telescope, FAST will enable astronomers to jumpstart many of the science goals, for example, the neutral hydrogen line surveying in distant galaxies out to very large redshifts, looking for the first shining star, detecting thousands of new pulsars, etc. Extremely interesting and exotic objects may yet await discovery by FAST. As a multi-science platform, the telescope will provide treasures to astronomers, as well as bring prosperity to other research, e.g. space weather study, deep space exploration and national security. The construction of FAST itself is expected to promote the development in high technology of relevant fields.

Jaap F. Hamming - One of the best experts on this subject based on the ideXlab platform.

  • Taking Morbidity and Mortality Conferences to a Next Level: The Resilience Engineering Concept.
    Annals of surgery, 2020
    Co-Authors: Merel J. Verhagen, Marit S. De Vos, Jaap F. Hamming
    Abstract:

    OBJECTIVE To explore possibilities to improve morbidity and mortality conferences using advancing insights in safety science. SUMMARY BACKGROUND DATA Mortality and Morbidity conferences (M&M) are the golden practice for case-based learning. While learning from complications is useful, M&M does not meet expectations for system-wide improvement. Resilience Engineering principles may be used to improve M&M. METHODS After a review of the shortcomings of traditional M&M, resilience Engineering principles are explored as a new way to evaluate performance. This led to the development of a new M&M format that also reviews successful outcomes, rather than only complications. This "quality assessment meeting" (QAM) is presented and the first experiences are evaluated using local observations and a survey. RESULTS During the QAM teams evaluate all discharged patients, addressing team resilience in terms of surgeons' ability to respond to irregularities and to monitor and learn from experiences. The meeting was feasible to implement and well received by the surgical team. Observations reveal that reflection on both complicated and uncomplicated cases strengthened team morale but also triggered reflection on the entire clinical course. The QAM serves as a tool to identify how adapting behavior led to success despite challenging conditions, so that this resilient performance can be supported. CONCLUSIONS The resilience Engineering Concept can be used to adjust M&M, in which learning is focused not only on complications but also on how successful outcomes were achieved despite ever-present challenges. This reveals the actual ratio between successful and unsuccessful outcomes, allowing to learn from both to reinforce safety-enhancing behavior.

William G. Wilson - One of the best experts on this subject based on the ideXlab platform.

  • Ecosystem Engineering in space and time.
    Ecology letters, 2007
    Co-Authors: Alan Hastings, Clive G. Jones, James E Byers, Jeffrey A Crooks, John G Lambrinos, Theresa Sinicrope Talley, Kim Cuddington, William G. Wilson
    Abstract:

    The ecosystem Engineering Concept focuses on how organisms physically change the abiotic environment and how this feeds back to the biota. While the Concept was formally introduced a little more than 10 years ago, the underpinning of the Concept can be traced back to more than a century to the early work of Darwin. The formal application of the idea is yielding new insights into the role of species in ecosystems and many other areas of basic and applied ecology. Here we focus on how temporal, spatial and organizational scales usefully inform the roles played by ecosystem engineers and their incorporation into broader ecological contexts. Two particular, distinguishing features of ecosystem engineers are that they affect the physical space in which other species live and their direct effects can last longer than the lifetime of the organism--Engineering can in essence outlive the engineer. Together, these factors identify critical considerations that need to be included in models, experimental and observational work. The ecosystem Engineering Concept holds particular promise in the area of ecological applications, where influence over abiotic variables and their consequent effects on biotic communities may facilitate ecological restoration and counterbalance anthropogenic influences.

X. Peng - One of the best experts on this subject based on the ideXlab platform.

  • Why is the influence of soil macrofauna on soil structure only considered by soil ecologists?
    Soil and Tillage Research, 2015
    Co-Authors: N. Bottinelli, Pascal Podwojewski, Pascal Jouquet, Yvan Capowiez, Michel Grimaldi, X. Peng
    Abstract:

    These last twenty years have seen the development of an abundant literature on the influence of soil macrofauna on soil structure. Amongst these organisms, earthworms, termites and ants are considered to play a key role in regulating the physical, chemical and microbiological properties of soils. Due to these influential impacts, soil ecologists consider these soil macro-invertebrates as 'soil engineers' and their diversity and abundance are nowadays considered as relevant bioindicators of soil quality by many scientists and policy makers. Despite this abundant literature, the soil Engineering Concept remains a 'preach to the choir' and bioturbation only perceived as important for soil ecologists. We discussed in this article the main mechanisms by which soil engineers impact soil structure and proposed to classify soil engineers with respect to their capacity to produce biostructures and modify them. We underlined the lack of studies considering biostructure dynamics and presented recent techniques in this purpose. We discussed why soil Engineering Concept is mainly considered by soil ecologists and call for a better collaboration between soil ecologists and soil physicists. Finally, we summarized main challenges and questions that need to be answered to integrate soil engineers activities in soil structure studies.

Han Olff - One of the best experts on this subject based on the ideXlab platform.

  • large scale ecosystem Engineering by flamingos and fiddler crabs on west african intertidal flats promote joint food availability
    Oikos, 2019
    Co-Authors: Elhacen Mohamed Elhacen, Tjeerd J Bouma, Puck Oomen, Theunis Piersma, Han Olff
    Abstract:

    Although the ecosystem Engineering Concept is well established in ecology, cases of joint Engineering by multiple species at large scales remain rare. Here, we combine observational studies and exclosure experiments to investigate how co-occurring greater flamingos Phoenicopterus roseus and fiddler crabs Uca tangeri promote their own and each other's food availability by creating a spatially complex mosaic of depressions (bowls, gullies) and hummocks (plateaus, mounds) in the intertidal zone. This results in a mosaic of microhabitats with different tidal inundation regimes. These microhabitats are spatially organized with labyrinth-like patterns in the high intertidal zone and spotted patterns in the lower intertidal, both of which likely arise from biophysical interactions between these organisms and hydrodynamic forces. We show that the resulting spatial complexity is vital for biofilm production. The depression microhabitats were wetter and richer in organic matter and biofilms compared with hummocks. Excluding flamingos and crabs resulted in an increase in biofilm biomass over the shorter term (six months), but a decrease over the longer term (after one year). Moreover, our results strongly suggest that these biogeomorphological microhabitats in the mosaics were maintained by the feeding activities of flamingos and to a lesser extent crabs. During a period of flamingo exclusion, all the spotted patterns filled up with sediment, while the exclusion of crabs led to gradual sediment accumulation in the labyrinth-like patterns. Collectively, these findings provide empirical evidence for large-scale joint promotion of food availability by multiple taxa in a marine ecosystem.