An Application of the Coda Methodology for Moment-Rate Spectra Using Broadband Stations in Turkey (open access)

An Application of the Coda Methodology for Moment-Rate Spectra Using Broadband Stations in Turkey

A recently developed coda magnitude methodology was applied to selected broadband stations in Turkey for the purpose of testing the coda method in a large, laterally complex region. As found in other, albeit smaller regions, coda envelope amplitude measurements are significantly less variable than distance-corrected direct wave measurements (i.e., L{sub g} and surface waves) by roughly a factor 3-to-4. Despite strong lateral crustal heterogeneity in Turkey, they found that the region could be adequately modeled assuming a simple 1-D, radially symmetric path correction. After calibrating the stations ISP, ISKB and MALT for local and regional distances, single-station moment-magnitude estimates (M{sub W}) derived from the coda spectra were in excellent agreement with those determined from multistation waveform modeling inversions, exhibiting a data standard deviation of 0.17. Though the calibration was validated using large events, the results of the calibration will extend M{sub W} estimates to significantly smaller events which could not otherwise be waveform modeled. The successful application of the method is remarkable considering the significant lateral complexity in Turkey and the simple assumptions used in the coda method.
Date: July 11, 2004
Creator: Eken Tuna, Kevin Mayeda, Abraham Hofstetter, Rengin Gok, Gonca Orgulu, Niyazi Turkelli
System: The UNT Digital Library
Protein-folding via divide-and-conquer optimization (open access)

Protein-folding via divide-and-conquer optimization

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Date: July 11, 2004
Creator: Oliva, Ricardo; Crivelli, Silvia & Meza, Juan
System: The UNT Digital Library
Synthesis and Characterization of Network Single Ion Conductors(NSIC) Based On Comb-Branched Polyepoxide Ethers and LithiumBis(allylmalonato)borate (open access)

Synthesis and Characterization of Network Single Ion Conductors(NSIC) Based On Comb-Branched Polyepoxide Ethers and LithiumBis(allylmalonato)borate

Network single ion conductors (NSICs) based on comb-branch polyepoxide ethers and lithium bis(allylmalonato) borate have been synthesized and thoroughly characterized by means of ionic conductivity measurements, electrochemical impedance and by dynamic mechanical analysis (DMA). The materials have been tested as battery electrolytes by cycling in symmetrical Li/Li half cells and in Li/V{sub 6}O{sub 13} full cells in which the NSIC was used as both binder and electrolyte in the cathode electrode and as the electrolyte separator membrane,. The substitution of the trimethylene oxide (TMO) unit into the side chains in place of ethylene oxide (EO) units increased the polymerion mobility (lower glass transition temperature). However, the ionic conductivity was nearly one and half orders of magnitude lower than the corresponding pure EO based single ion conductor at the same salt concentration. This effect may be ascribed to the lower dielectric constant of the TMO side chains that result in a lower concentration of free conducting lithium cations. For a highly cross-linked system (EO/Li=20), only 47 wt% plasticizing solvent (ethylene carbonate (EC)/ethyl methyl carbonate (EMC), 1/1 by wt) could be taken up and the ionic conductivity was only increased by one order of magnitude over the dry polyelectrolyte while for a …
Date: July 11, 2004
Creator: Sun, Xiao-Guang & Kerr, John B.
System: The UNT Digital Library