7,099 research outputs found

    Major Problems of Catholic Hospitals in Medical Education

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    Global change of land use systems : IMAGE: a new land allocation module

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    The Integrated Model to Assess the Global Environment (IMAGE) aims at assessing the state of the environment taking into account the effects of human activities. Although human population often makes use of a land area to satisfy various needs, most of the current global land use datasets and models use a classification based on dominant land use/cover types disregarding the diversity and intensity of human activities. In this working document we investigate if the simulation of land use change and the IMAGE outcomes can be improved by using a classification based on land use systems. An expert based cluster analysis was used to identify and map land use systems. The analysis accounted for population density, accessibility, land use / cover types and livestock and provided a new insight on human interactions with the environment. Then, a conceptual framework was developed and implemented to simulate land use systems changes based on local conditions and demand for agricultural products and accounting for land management changes

    Hybrid Rocket Engine Ignition and Control

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    Control of a hybrid rocket engine is dependent upon a robust system capable of executing commands at precise times. In order to accomplish this, hardware systems must be in place to control the flow of a pressurized gas and provide feedback to launch site personnel. Through the use of solenoid valves and wireless transceivers, control over the thrust of a rocket can be accomplished. In order to understand this information and provide a user-friendly interface to complete this, a launch control module is used. Through the combined capabilities of the two system it becomes possible to test and launch a hybrid engine rocket in a safe and efficient manner

    Dust emission by powder handling: Influence of the hopper outlet on the dust plume

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    Dust generation in solids handling involving free fall of bulk materials and impacts on a stockpile can cause many problems in industry and be a great danger for operators health. This paper describes an experimental set up to characterize the dust plume formed in free fall of powders from a hopper and investigates the influence of various outlet geometries on the dust plume. For this purpose an image analysis technique was developed to quantify the characteristics of the dust plume

    Experimental study of high pressure phase equilibrium of (CO2 + NO2/N2O4) mixtures

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    Experimental bubble pressure, as well as liquid density of (CO2 + NO2/N2O4) mixtures are reported at temperatures ranging from (298 to 328.45) K. Experiments were carried out using a SITEC high-pressure variable volume cell. Transition pressures were obtained by the synthetic method and liquid density was deduced from measurement of the cell volume. Correlation of experimental results was carried out without considering chemical equilibrium of NO2/N2O4 system. (Liquid + vapour) equilibrium was found to be accurately modelled using the Peng–Robinson equation of state with classical quadratic mixing rules and with a binary interaction coefficient kij equal to zero. Nevertheless, modelling of liquid density values was unsatisfactory with this approach

    Delayed neutrons measurement at the MEGAPIE target

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    In the framework of the Neutronic and Nuclear Assessment Task Group of the MEGAPIE experiment we measured the delayed neutron (DN) flux at the top of the target. The measurement was proposed mainly for radioprotection purposes since the DN flux at the top of the target has been estimated to be of the same order of magnitude as the prompt neutron flux. Given the strong model-dependence of DN predictions, the measurement of DN contribution to the total neutron activity at the top of the target was thus desired. Moreover, this measurement is complementary to the DN experiments performed at PNPI (Gatchina) on solid lead and bismuth targets. The DN measurement at MEGAPIE was performed during the start-up phase of the target. In this paper we present a detailed description of the experimental setup and some preliminary results on decay spectra.Comment: 4 pages, 4 figures, Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2007), Nice, France, 22-27 Apr 200
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