14,936 research outputs found

    A Regional Assessment of Florida Manatees (Trichechus manatus latirostris) and the Caloosahatchee River, Florida

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    (58pp.

    Restoring Trust Relationships within Collaborative Digital Preservation Federations

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    4th International Conference on Open RepositoriesThis presentation was part of the session : Conference PresentationsDate: 2009-05-19 01:00 PM – 02:30 PMThe authors extend their process for creating and establishing trust relationships to include steps for restoring trust relationships after catastrophic events. Part of this model will include best practices for business continuity relationships and will integrate trust models from Holland and Lockett (1998) and Ring and Van de Ven (1994) and how they can be applied to a process for trust restoration after periods of disaster or critical data loss. These models provide key frameworks for understanding how trust can be utilized for collaborative start points as well as for collaborative recovery points from physical natural disaster or critical data loss

    A low molecular weight hydrogel with unusual gel aging

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    We describe a dipeptide hydrogel with unusual aging characteristics. Over time, a transformation from a turbid gel to a transparent gel occurs which is initiated from the air–water interface. Here, we investigate this transition and discuss the implications of this aging on the bulk properties of the gel

    Derivation and evaluation of an approximate analysis for three-dimensional viscous subsonic flow with large secondary velocities

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    An approximate analysis is presented for calculating three-dimensional, low Mach number, laminar viscous flows in curved passages with large secondary flows and corner boundary layers. The analysis is based on the decomposition of the overall velocity field into inviscid and viscous components with the overall velocity being determined from superposition. An incompressible vorticity transport equation is used to estimate inviscid secondary flow velocities to be used as corrections to the potential flow velocity field. A parabolized streamwise momentum equation coupled to an adiabatic energy equation and global continuity equation is used to obtain an approximate viscous correction to the pressure and longitudinal velocity fields. A collateral flow assumption is invoked to estimate the viscous correction to the transverse velocity fields. The approximate analysis is solved numerically using an implicit ADI solution for the viscous pressure and velocity fields. An iterative ADI procedure is used to solve for the inviscid secondary vorticity and velocity fields. This method was applied to computing the flow within a turbine vane passage with inlet flow conditions of M = 0.1 and M = 0.25, Re = 1000 and adiabatic walls, and for a constant radius curved rectangular duct with R/D = 12 and 14 and with inlet flow conditions of M = 0.1, Re = 1000, and adiabatic walls

    Utilities and the Public Roadway - Just Whose Property is it, Anyway?

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    Comparison between flying capacitor and modular multilevel inverter

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    The paper describes the operational principle of flying capacitor and modular multilevel inverters. The detailed discussions of dc link capacitors voltage balancing methods for both inverters are given in order to enable fair comparison. The causes of dc link capacitors voltage imbalance in flying capacitor multilevel inverter with more than three levels are highlighted. Computer simulation is used to compare the performance of both inverters under several operating conditions

    Comparison between two VSC-HVDC transmission systems technologies : modular and neutral point clamped multilevel converter

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    The paper presents a detail comparison between two voltage source converter high voltage dc transmission systems, the first is based on neutral point-clamped (also known as HVDC-Light) and the second is based on innovative modular multilevel converter (known as HVDC-Plus). The comparison focuses on the reliability issues of both technologies such as fault ride-through capability and control flexibility. To address these issues, neutral point-clamped and three-level modular converters are considered in both stations of the dc transmission system, and several operating conditions are considered, including, symmetrical and asymmetrical faults. Computer simulation in Matlab-Simulink environment has been used to confirm the validity of the results

    Resonance assignments for latherin, a natural surfactant protein from horse sweat

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    Latherin is an intrinsically surfactant protein of ~23 kDa found in the sweat and saliva of horses. Its function is probably to enhance the translocation of sweat water from the skin to the surface of the pelt for evaporative cooling. Its role in saliva may be to enhance the wetting, softening and maceration of the dry, fibrous food for which equines are adapted. Latherin is unusual in its relatively high content of aliphatic amino acids (~25 % leucines) that might contribute to its surfactant properties. Latherin is related to the palate, lung, and nasal epithelium carcinoma-associated proteins (PLUNCs) of mammals, at least one of which is now known to exhibit similar surfactant activity to latherin. No structures of any PLUNC protein are currently available. 15N,13C-labelled recombinant latherin was produced in Escherichia coli, and essentially all of the resonances were assigned despite the signal overlap due to the preponderance of leucines. The most notable exceptions include a number of residues located in an apparently dynamic loop region between residues 145 and 154. The assignments have been deposited with BMRB accession number 19067

    Modelling the alumina abundance of oxygen-rich evolved stars in the Large Magellanic Cloud

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    In order to determine the composition of the dust in the circumstellar envelopes of oxygen-rich asymptotic giant branch (AGB) stars we have computed a grid of modust radiative-transfer models for a range of dust compositions, mass-loss rates, dust shell inner radii and stellar parameters. We compare the resulting colours with the observed oxygen-rich AGB stars from the SAGE-Spec Large Magellanic Cloud (LMC) sample, finding good overall agreement for stars with a mid-infrared excess. We use these models to fit a sample of 37 O-rich AGB stars in the LMC with optically thin circumstellar envelopes, for which 5-35-μ\mum Spitzer infrared spectrograph (IRS) spectra and broadband photometry from the optical to the mid-infrared are available. From the modelling, we find mass-loss rates in the range 8×108\sim 8\times10^{-8} to 5×1065\times10^{-6} M yr1_{\odot}\ \mathrm{yr}^{-1}, and we show that a grain mixture consisting primarily of amorphous silicates, with contributions from amorphous alumina and metallic iron provides a good fit to the observed spectra. Furthermore, we show from dust models that the AKARI [11]-[15] versus [3.2]-[7] colour-colour diagram, is able to determine the fractional abundance of alumina in O-rich AGB stars.Comment: 22 pages, 17 figures, accepted MNRA

    Angular dependent magnetothermopower of alpha-(ET)2KHg(SCN)4

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    The magnetic field and angular dependencies of the thermopower and Nernst effect of the quasi-two-dimensional organic conductor alpha-(ET)2KHg(SCN)4 are experimentally measured at temperatures below (4 K) and above (9 K) the transition temperature to fields of In addition, a theoretical model which involves a magnetic breakdown effect between the q1D and q2D bands is proposed in order to simulate the data. Analysis of the background components of the thermopower and Nernst effect imply that at low temperatures, in the CDW state, the properties of alpha-(ET)2KHg(SCN)4 are determined mostly by the orbits on the new open Fermi sheets. Quantum oscillations observed in the both thermoelectric effects, at fields above 8 T, originate only from the alpha orbit.Comment: 25 pages, 18 figure
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