The cosmic ray energy spectrum between 10 and 10 eV     

M. A. K. Glasmacher  M. A. Catanese  M. C. Chantell  C. E. Covault  J. W. Cronin  B. E. Fick  L. F. Fortson  J. W. Fowler  K. D Green  D. B. Kieda  J. Matthews  B. J. Newport  D. F. Nitz  R. A. Ong  S. Oser  D. Sinclair  J. C. van der Velde 《Astroparticle Physics》1999,10(4):183-302

The energy spectrum of cosmic rays with primary energies between 10¹⁴ eV and 10¹⁶ eV has been studied with the CASA-MIA air shower array. The measured differential energy spectrum is a power law (dj/dE ∝ E^−y) with spectral indices γ of 2.66±0.02 below approximately 10¹⁵ eV and 3.00±0.05 above. A new method is used for measuring primary energy derived from ground-based data in a compositionally insensitive way. In contrast with some previous reports, the “knee” of the energy spectrum does not appear sharp, but rather a smooth transition over energies from 10¹⁵ eV to 3.0 × 10¹⁵ eV.  相似文献   

Technical guidelines for the assessment of earthquake induced liquefaction hazard at urban scale     

Lai  C. G.  Bozzoni  F.  Conca  D.  Famà  A.  Özcebe  A. G.  Zuccolo  E.  Meisina  C.  Bonì  R.  Bordoni  M.  Cosentini  R. M.  Martelli  L.  Poggi  V.  Viana da Fonseca  A.  Ferreira  C.  Rios  S.  Cordeiro  D.  Ramos  C.  Molina-Gómez  F.  Coelho  C.  Logar  J.  Maček  M.  Oblak  A.  Ozcep  F.  Bozbey  I.  Oztoprak  S.  Sargin  S.  Aysal  N.  Oser  C.  Kelesoglu  M. K. 《Bulletin of Earthquake Engineering》2021,19(10):4013-4057

Bulletin of Earthquake Engineering - Microzonation for earthquake-induced liquefaction hazard is the subdivision of a territory at a municipal or submunicipal scale in areas characterized by the...  相似文献   

Site classification using equivalent soil profiles for building-liquefaction interaction     

Millen  Maxim  Viana da Fonseca  Antonio  Quintero  Julieth  Ferreira  Cristiana  Oztoprak  Sadik  Oser  Cihan  Bozbey  Ilknur  Aysal  Namik  Kosič  Mirko  Logar  Janko 《Bulletin of Earthquake Engineering》2021,19(10):3987-4012

The seismic behaviour of a building on a liquefiable deposit is a complex interaction which involves quantifying both shaking induced damage and permanent ground deformation-related damage. In this paper the key parameters that influence both surface shaking and foundation settlements have been identified as the depth, thickness and liquefaction resistance of an equivalent liquefiable layer. These parameters can be used to develop an ‘equivalent soil profile’ that is analogous to the equivalent single degree-of-freedom that reduces the complexity of the dynamic response of a building into comparable and easily understood quantities. The equivalent soil profile is quantified independent of the seismic hazard, making it compatible with performance based design and assessment frameworks such that the building and soil profile can be directly assessed at different levels of seismic hazard. Several numerical studies are presented that demonstrate the influence of these key parameters on the ground surface shaking and foundation settlement. A set of criteria are proposed for classifying soil profiles into 22 different soil classes for regional loss assessment. An algorithm was developed for automatically fitting the equivalent soil profile to a cone penetration test trace and issues with the fitting are discussed. Field reconnaissance was undertaken to collect additional data to support existing datasets on the performance of buildings in Adapazari, during the 1999 Kocaeli, Turkey, earthquake (Mw = 7.4). The field case history data was used to investigate the correlation between the depth, thickness and liquefaction resistance of an equivalent liquefiable layer, on the extent of foundation permanent deformation. The case history data showed that in general a shallow, thick and weak liquefiable layer near the surface results in significant settlement but a lack of data for buildings on non-liquefiable deposits and the additional complexities involved with real buildings and soil deposits, meant that the trends observed in the idealised numerical models could not identified in the field case history data set.

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Detection of atmospheric Cherenkov radiation using solar heliostat mirrors     

A. Ong R.  D. Bhattacharya  C. E. Covault  D. D. Dixon  D. T. Gregorich  D. S. Hanna  S. Oser  J. Qu  bert  D. A. Smith  O. T. Tü  mer  A. D. Zych 《Astroparticle Physics》1996,5(3-4):353-365

There is considerable interest world-wide in developing large area atmospheric Cherenkov detectors for ground-based gamma-ray astronomy. This interest stems, in large part, from the fact that the gamma-ray energy region between 20 and 250 GeV is unexplored by any experiment. Atmospheric Cherenkov detectors offer a possible way to explore this region, but large photon collection areas are needed to achieve low energy thresholds. We are developing an experiment using the heliostat mirrors of a solar power plant as the primary collecting element. As part of this development, we built a detector using four heliostat mirrors, a secondary Fresnel lens, and a fast photon detection system. In November 1994, we used this detector to record atmospheric Cherenkov radiation produced by cosmic ray particles showering in the atmosphere. The detected rate of cosmic ray events was consistent with an energy threshold near 1 TeV. The data presented here represent the first detection of atmospheric Cherenkov radiation using solar heliostats viewed from a central tower.  相似文献