297 research outputs found

    Modelling the Influence of Climate on the Performance of the Organic Rankine Cycle for Industrial Waste Heat Recovery

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    Paper is published using the open access gold route Dr Korolija is now working at UCL Energy Institute, University College London, 14 Upper Woburn Place, London WC1H 0NN [email protected] paper describes a study of the relative influences of different system design decisions upon the performance of an organic Rankine cycle (ORC) used to generate electricity from foundry waste heat. The design choices included concern the working fluid, whether to use a regenerator and the type of condenser. The novelty of the research lies in its inclusion of the influence of both the ORC location and the auxiliary electricity used by the pumps and fans in the ORC power system. Working fluids suitable for high temperature applications are compared, including three cyclic siloxanes, four linear siloxanes and three aromatic fluids. The ORC is modelled from first principles and simulation runs carried out using weather data for 106 European locations and a heat input profile that was derived from empirical data. The impact of design decisions upon ORC nominal efficiency is reported followed by the impact upon annual system efficiency in which variations in heat input and the condition of outdoor air over a year are considered. The main conclusion is that the location can have a significant impact upon the efficiency of ORC systems due to the influence of climate upon the condenser and auxiliary electricity requirements

    UCLA Intermediate Energy Nuclear and Particle Physics Research: Final Report

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    This project covers the following research: (a) Investigations into the structure of the proton and neutron. This is done by investigating the different resonance states of nucleons with beams of tagged, polarized photons, linearly as well as circularly, incident on polarized hydrogen/deuterium targets and measuring the production of {pi}{sup #25;0}, 2{pi}{sup #25;}0, 3{pi}{sup #25;0}, {eta}#17;, {eta}', {omega}, etc. The principal detector is the Crystal Ball multiphoton spectrometer which has an acceptance of nearly 4#25;. It has been moved to the MAMI accelerator facility of the University of Mainz, Germany. We investigate the conversion of electromagnetic energy into mesonic matter and conversely. (b) We investigate the consequences of applying the "standard" symmetries of isospin, GâÂÂparity, charge conjugation, C, P, T, and chirality using rare and forbidden decays of light mesons such as the {eta}#17;,{eta}' and {omega}. We also investigate the consequences of these symmetries being slightly broken symmetries. We do this by studying selected meson decays using the Crystal Ball detector. (c) We determine the mass, or more precisely the mass difference of the three light quarks (which are inputs to Quantum Chromodynamics) by measuring the decay rate of specially selected {eta}#17; and {eta}' decay modes, again we use the Crystal Ball. (d)We have started a new program to search for the 33 missing cascade baryons using the CLAS detector at the Thomas Jefferson Laboratory. Cascade resonances are very special: they have double strangeness and are quite narrow. This implies that they can be discovered by the missing mass technique in photoproduction reactions such as in {gamma}p{yields}{Xi}{sup #4;âÂÂ}K{sup +}K{sup +}. The cascade program is of particular importance for the upgrade to 12 GeV of the CLAS detector and for design of the Hall D at JLab. (e) Finally, we are getting more involved in a new program to measure the hadronic matter form factor of complex nuclei, in particular the "neutron skin" of {sup 208}Pb, which is of great interest to astroparticle physics for determining the properties of neutron stars. Processes of study are coherent and nonâÂÂcoherent #25;0 photoproduction. The Crystal Ball is uniquely suited for these studies because of the large acceptance, good direction and energy resolution and it is an inclusive detector for the #25;{pi}{sup 0} final state and exclusive for background such as 2#25;{pi}{sup 0}

    "It happened, what's the problem?" and "A guide through the problem" - A model for consideration of ecological issues in chemistry education

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    In order to improve the ability to apply knowledge of chemistry (acquired in the existing educational system) in real life, the model for consideration of ecological issues was developed and applied in high school. The model consists of a continuous text "It Happened, What's the Problem?" and a test with non-continuous text "A Guide Through the Problem", which were prepared for consideration of the problem of eutrophication. All results obtained (average achievement of 70.9 +/- 14.3 %) showed that the application of the model enabled: understanding of an ecological problem based on scientific representations of the term eutrophication given in the continuous text, realization that pollution of the environment may be directly related to modern life, application of acquired knowledge of chemistry to observe and understand the cause and effect of eutrophication in the environment, to draw a scientific conclusion, and understanding the importance of science and technology discoveries for solving ecological problems. In addition, the model contributed to the development of student's environmental literacy (ecological knowledge and cognitive skills), ability to think critically, and provided possibilities for classroom knowledge to become applicable in real life

    PEN: a low energy test of lepton universality

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    Allowed charged π\pi meson decays are characterized by simple dynamics, few available decay channels, mainly into leptons, and extremely well controlled radiative and loop corrections. In that sense, pion decays represent a veritable triumph of the standard model (SM) of elementary particles and interactions. This relative theoretical simplicity makes charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for studying pion structure and chiral dynamics. Even after considerable recent improvements, experimental precision is lagging far behind that of the theoretical description for pion decays. We review the current state of experimental study of the pion electronic decay π+e+νe(γ)\pi^+ \to e^+\nu_e(\gamma), or πe2(γ)\pi_{e2(\gamma)}, where the (γ)(\gamma) indicates inclusion and explicit treatment of radiative decay events. We briefly review the limits on non-SM processes arising from the present level of experimental precision in πe2(γ)\pi_{e2(\gamma)} decays. Focusing on the PEN experiment at the Paul Scherrer Institute (PSI), Switzerland, we examine the prospects for further improvement in the near term.Comment: 11 pages, 5 figures; paper presented at the XIII International Conference on Heavy Quarks and Leptons, 22-27 May 2016, Blacksburg, Virginia, US

    Reconstruction of 3D models of cast sculptures using close-range photogrammetry

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    This paper presents the possibilities of application of close-range photogrammetry, based on the Structure-from- Motion (SfM) approach, in 3D model’s reconstruction of bronze cast sculptures. Special attention was dedicated to the analysis of image processing strategy, and its impact on the 3D model reconstruction quality. For the purpose of analysis a bust of Nikola Tesla, placed in front of the Faculty of Technical Sciences University of Novi Sad was used. Experimental results indicate that the strategy employing multi-group photo processing provides substantial reductions in processing time while providing satisfactory results in 3D reconstruction
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