ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Aircraft Design, Testing and Performance
  • Industrial Chemistry
  • Inorganic Chemistry
  • Seismology
  • Acoustical Society of America  (2)
  • Earthquake Engineering Research Institute  (1)
  • 2005-2009  (3)
  • 1950-1954
  • 1935-1939
  • 1
    facet.materialart.
    Unbekannt
    Acoustical Society of America
    Publikationsdatum: 2022-05-25
    Beschreibung: Author Posting. © Acoustical Society of America, 2007. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 122 (2007): 777-785, doi:10.1121/1.2751268.
    Beschreibung: A highly efficient frequency-controlled sound source based on a tunable high-Q underwater acoustic resonator is described. The required spectrum width was achieved by transmitting a linear frequency-modulated signal and simultaneously tuning the resonance frequency, keeping the sound source in resonance at the instantaneous frequency of the signal transmitted. Such sound sources have applications in ocean-acoustic tomography and deep-penetration seismic tomography. Mathematical analysis and numerical simulation show the Helmholtz resonator's ability for instant resonant frequency switching and quick adjustment of its resonant frequency to the instantaneous frequency signal. The concept of a quick frequency adjustment filter is considered. The discussion includes the simplest lumped resonant source as well as the complicated distributed system of a tunable organ pipe. A numerical model of the tunable organ pipe is shown to have a form similar to a transmission line segment. This provides a general form for the principal results, which can be applied to tunable resonators of a different physical nature. The numerical simulation shows that the “state-switched” concept also works in the high-Q tunable organ pipe, and the speed of frequency sweeping in a high-Q tunable organ pipe is analyzed. The simulation results were applied to a projector design for ocean-acoustic tomography.
    Beschreibung: The work was supported by ONR.
    Schlagwort(e): Acoustic generators ; Underwater sound ; Acoustic resonators ; Oceanographic equipment ; Seismology
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2022-05-26
    Beschreibung: Author Posting. © Acoustical Society of America, 2008. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 123 (2008): 667-678, doi:10.1121/1.2821975.
    Beschreibung: This paper introduces a perturbative inversion algorithm for determining sea floor acoustic properties, which uses modal amplitudes as input data. Perturbative inverse methods have been used in the past to estimate bottom acoustic properties in sediments, but up to this point these methods have used only the modal eigenvalues as input data. As with previous perturbative inversion methods, the one developed in this paper solves the nonlinear inverse problem using a series of approximate, linear steps. Examples of the method applied to synthetic and experimental data are provided to demonstrate the method's feasibility. Finally, it is shown that modal eigenvalue and amplitude perturbation can be combined into a single inversion algorithm that uses all of the potentially available modal data.
    Beschreibung: Funding for the research presented here was provided by the Office of Naval Research, and the WHOI Academic Programs Office.
    Schlagwort(e): Geophysical techniques ; Inverse problems ; Sediments ; Seismology
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    facet.materialart.
    Unbekannt
    Earthquake Engineering Research Institute
    Publikationsdatum: 2017-04-04
    Beschreibung: Two earthquakes (both having Mw 5.7) struck the eastern portion of Molise on October 31 and November 1, 2002. Both caused severe damage over a 2000 km2 region straddling Molise and Puglia. The two larger shocks and the rather unusual aftershock sequence surprised most Italian seismologists and tectonicists. Although Italy has a good record of historical and instrumental seismicity and its main seismogenic trends are quite established, the epicentral location, depth and kinematics of this earthquake sequence were largely unexpected. In fact, the 2002 Molise earthquakes shed light on a previously unsuspected style of seismogenic faulting in this region. From the seismotectonic perspective, much of the significance of the two quakes arises from the possibility that this style of faulting might be shared by several much larger quakes that took place on the Adriatic side of the southern Apennines. In the first part of this paper we briefly describe the main seismological characteristics of the sequence. These were largely derived from the analysis of data supplied by permanent networks and from a preliminary analysis of data recorded by a portable network deployed a few hours after the first shock. In the second part of the paper we discuss the seismotectonic characteristics of the sequence in the framework of Italian tectonics and the implications for future earthquakes in the same region.
    Beschreibung: Published
    Beschreibung: S23-S37
    Beschreibung: reserved
    Schlagwort(e): Earthquake ; Molise 2002 ; Seismology ; Tectonic ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Format: 1422638 bytes
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...