1,072 research outputs found
Assessment of unintentional islanding operations in distribution networks with large induction motors
This paper is aimed at assessing the impact of unintentional islanding operations (IOs) in the presence of large induction motors (IMs) within distribution networks (DNs). When a fault occurs,followingthecircuitbreaker(CB)faultclearing,theIMsacttransientlyasgenerators,duetoits inertia, until the CB reclosing takes place. The present work is the outcome of a project carried out in a small DN, where ¿eld measurements were recorded over two years. This paper provides a detailed description of the test system, a selected list of ¿eld measurements, and a discussion on modeling guidelinesusedtocreatethemodeloftheactualpowersystem. Themaingoalistovalidatethesystem model by comparing ¿eld measurements with simulation results. The comparison of simulations and ¿eld measurements prove the appropriateness of the modeling guidelines used in this work and highlight the high accuracy achieved in the implemented three-phase Matlab/Simulink modelPostprint (published version
Further information on the life of Charles Moore (1815-1881), Somerset geologist.
Copp et al. (1999) published an account of the life and work of Charles Moore, the Victorian amateur geologist whose fine collection is now held mainly by the Bath Royal Literary and Scientific Institution and the Somerset County Museum, Taunton. This note aims to amend and extend some information in that paper
An account of Mary Anning (1799-1847), fossil collector of Lyme Regis, Dorset, England, published by Henry Rowland Brown (1837-1921) in the second edition (1859) of Beauties of Lyme Regis
The publication of the now rare second edition of the guidebook The Beauties of Lyme Regis... by Lyme native Henry Rowland Brown (1837-1921) is dated to 1859. The known link of Brown’s family to Anning’s increases the significance of his book as a source for her, particularly the second edition which has a more extensive account of her than the first; relevant extracts are reproduced. His book has become a major source for writers on Anning, but only in corrupted form because of incompetent piracy by a later writer in a general magazine
An anonymous account of Mary Anning (1799-1847), fossil collector of Lyme Regis, Dorset, England, published in All the year round in 1865, and its attribution to Henry Stuart Fagan (1827-1890), schoolmaster, parson and author
An article on the fossil collector Mary Anning (1799-1847), published in All the Year Round in 1865, and much used in Anning literature, is usually ascribed to Charles Dickens. In fact it was by the Reverend Henry Stuart Fagan (1827-1890), grammar school headmaster, Church of England parson, and literary man. It is neither original nor reliable, and introduced errors into the Anning literature which are still problematic. The methodology of attribution of anonymous articles is discussed
Dynamic Kerr Effect and Spectral Weight Transfer in the Manganites
We perform pump-probe Kerr spectroscopy in the colossally magnetoresistive
manganite Pr0.67Ca0.33MnO3. Kerr effects uncover surface magnetic dynamics
undetected by established methods based on reflectivity and optical spectral
weight transfer. Our findings indicate the connection between spin and charge
dynamics in the manganites may be weaker than previously thought. Additionally,
important differences between this system and conventional ferromagnetic metals
manifest as long-lived, magneto-optical coupling transients, which may be
generic to all manganites.Comment: 12 text pages, 4 figure
LAGOVirtual: A Collaborative Environment for the Large Aperture GRB Observatory
We present the LAGOVirtual Project: an ongoing project to develop platform to
collaborate in the Large Aperture GRB Observatory (LAGO). This continental-wide
observatory is devised to detect high energy (around 100 GeV) component of
Gamma Ray Bursts, by using the single particle technique in arrays of Water
Cherenkov Detectors (WCD) at high mountain sites (Chacaltaya, Bolivia, 5300 m
a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m
a.s.l). This platform will allow LAGO collaboration to share data, and computer
resources through its different sites. This environment has the possibility to
generate synthetic data by simulating the showers through AIRES application and
to store/preserve distributed data files collected by the WCD at the LAGO
sites. The present article concerns the implementation of a prototype of
LAGO-DR adapting DSpace, with a hierarchical structure (i.e. country,
institution, followed by collections that contain the metadata and data files),
for the captured/simulated data. This structure was generated by using the
community, sub-community, collection, item model; available at the DSpace
software. Each member institution-country of the project has the appropriate
permissions on the system to publish information (descriptive metadata and
associated data files). The platform can also associate multiple files to each
item of data (data from the instruments, graphics, postprocessed-data, etc.).Comment: Second EELA-2 Conference Choroni, Venezuela, November 25th to 27th
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The tail of the Jurassic fish Leedsichthys problematicus (Osteichthyes: Actinopterygii) collected by Alfred Nicholson Leeds - an example of the importance of historical records in palaeontology
The specimen of the tail of <i>Leedsichthys problematicus</i>, now in The Natural History Museum, London, was one of the most spectacular fossil vertebrates from the Oxford Clay Formation of Peterborough, but as an isolated find it shares no bones in common with the holotype of the genus and species. However, a letter from Alfred Nicholson Leeds and related documents cast valuable new light on the excavation of the tail, indicating that it was discovered with cranial bones, gill-rakers, and two pectoral fins, thereby including elements that can potentially be compared with those of the holotype. The documents also clearly indicate that The Natural History Museum's specimen is not part of the same individual as any other numbered specimen of <i>Leedsichthys</i> as had been speculated on other occasions. The maximum size of the animal represented by The Natural History Museum's specimen was possibly around 9 metres, considerably less than previous estimates of up to 27.6 metres for <i>Leedsichthys</i>. Historical documentary evidence should therefore be rigorously checked both when studying historical specimens in science, and in preparing text for museum display labels
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