1,518 research outputs found

    Profit Limitation Controls Prior to the Present War

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    In March 2014, four organisations, the Global School (Den Globala Skolan), the Swedish International Centre of Education for Sustainable Development (SWEDESD) at Uppsala University, the Swedish National Commission for UNESCO (Svenska Unescorådet) and WWF-Sweden commissioned Anders Jidesjö, senior lecturer and researcher at Linköping University, to undertake a study of the Swedish experience in the domain of Education for Sustainable Development (ESD) over the last 10 years by analysing relevant background documentation and reports as well as information gathered through interviews with key informants. This report presents the result of this study. An earlier version served as background document for the "ESD – Call for Action" event on 3 June 2014 (see also below). The current version has benefited from incorporating factual information and insights presented during that event. The report was commissioned in view of the UNESCO World Conference on Education for Sustainable Development, scheduled for 11-12 November in Aichi-Nagoya, Japan. This conference will mark the end of the UN Decade on Education for Sustainable Development, 2005-2014. The four organisations considered that the official Swedish position at the Nagoya Conference would be strengthened if informed by the experiences and insights of Swedish pre-schools, schools, universities, municipalities and public, private and non-governmental organizations that over the last ten years and longer have engaged in education and learning for sustainable development. The official Swedish position would also be bolstered by having politicians, policy makers and experts reflect on these experiences and formulate recommendations for reinforced policy and accelerated and effective practice and research in the ESD domain. To this effect, the four organizations organized the event "ESD – Call for Action", on 3 June at Blåsenhus, Uppsala University. It brought together 120 representatives of Swedish ESD-related practitioners, researchers and policy makers who together formulated an extensive set of recommendations that are meant to support the Swedish delegation attending the Nagoya Conference. The report and the 3 June recommendations will be made available to the participants of a second event "Making ESD Action Possible", scheduled for 27 August, 2014 at Rosenbad Conference Centre, Stockholm. This event is expected to assemble 140 Swedish ESD-related politicians, policy makers, researchers and practitioners. The combined recommendations formulated by the participants during the two events will be submitted to the official Swedish delegation to the Nagoya Conference. August 2014 Den Globala Skolan (the Global School), Svenska Unescorådet (Swedish National Commission for UNESCO), Swedish International Centre of Education for Sustainable Development (SWEDESD) at Uppsala University, WWF-Swede

    Crisscross breeding of poultry

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    Clocked Atom Delivery to a Photonic Crystal Waveguide

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    Experiments and numerical simulations are described that develop quantitative understanding of atomic motion near the surfaces of nanoscopic photonic crystal waveguides (PCWs). Ultracold atoms are delivered from a moving optical lattice into the PCW. Synchronous with the moving lattice, transmission spectra for a guided-mode probe field are recorded as functions of lattice transport time and frequency detuning of the probe beam. By way of measurements such as these, we have been able to validate quantitatively our numerical simulations, which are based upon detailed understanding of atomic trajectories that pass around and through nanoscopic regions of the PCW under the influence of optical and surface forces. The resolution for mapping atomic motion is roughly 50 nm in space and 100 ns in time. By introducing auxiliary guided mode (GM) fields that provide spatially varying AC-Stark shifts, we have, to some degree, begun to control atomic trajectories, such as to enhance the flux into to the central vacuum gap of the PCW at predetermined times and with known AC-Stark shifts. Applications of these capabilities include enabling high fractional filling of optical trap sites within PCWs, calibration of optical fields within PCWs, and utilization of the time-dependent, optically dense atomic medium for novel nonlinear optical experiments

    A comparison of single-cycle versus multiple-cycle proof testing strategies

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    An evaluation of single-cycle and multiple-cycle proof testing (MCPT) strategies for SSME components is described. Data for initial sizes and shapes of actual SSME hardware defects are analyzed statistically. Closed-form estimates of the J-integral for surface flaws are derived with a modified reference stress method. The results of load- and displacement-controlled stable crack growth tests on thin IN-718 plates with deep surface flaws are summarized. A J-resistance curve for the surface-cracked configuration is developed and compared with data from thick compact tension specimens. The potential for further crack growth during large unload/reload cycles is discussed, highlighting conflicting data in the literature. A simple model for ductile crack growth during MCPT based on the J-resistance curve is used to study the potential effects of key variables. The projected changes in the crack size distribution during MCPT depend on the interactions between several key parameters, including the number of proof cycles, the nature of the resistance curve, the initial crack size distribution, the component boundary conditions (load vs. displacement control), and the magnitude of the applied load or displacement. The relative advantages of single-cycle and multiple-cycle proof testing appear to be specific, therefore, to individual component geometry, material, and loading

    Cellular-Automata model for dense-snow avalanches

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    This paper introduces a three-dimensional model for simulating dense-snow avalanches, based on the numerical method of cellular automata. This method allows one to study the complex behavior of the avalanche by dividing it into small elements, whose interaction is described by simple laws, obtaining a reduction of the computational power needed to perform a three-dimensional simulation. Similar models by several authors have been used to model rock avalanches, mud and lava flows, and debris avalanches. A peculiar aspect of avalanche dynamics, i.e., the mechanisms of erosion of the snowpack and deposition of material from the avalanche is taken into account in the model. The capability of the proposed approach has been illustrated by modeling three documented avalanches that occurred in Susa Valley (Western Italian Alps). Despite the qualitative observations used for calibration, the proposed method is able to reproduce the correct three-dimensional avalanche path, using a digital terrain model, and the order of magnitude of the avalanche deposit volume

    Closure and Growth of Fatigue Cracks at Notches

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    A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies

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    Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semielliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT versus SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application
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