Download or read book Acoustical Properties of Laboratory and in Situ Sediments written by P. J. Vidmar and published by . This book was released on 1983 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes work done during the period 1 August 1975-30 June 1983. Major accomplishments include: Development and use of instrumentation to perform in situ measurements of acoustical parameters of marine sediments, measurement of shear and compressional wave parameters of laboratory sediments, development of theoretical descriptions of acoustic propagation in sediments, and laboratory experiments to test various theoretical models of propagation in sediments.
Download or read book Acoustical Properties of Sediments written by and published by . This book was released on 1982 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work consisted of (1) final development of the ARL:UT profilometer recorder and transducer to enable the in situ measurement of compressional wave, shear wave, acoustic impedance, and static shear strength of ocean bottom sediments during geophysical coring, and (2) laboratory acoustical measurements on artificial sediments to test predictions of the Hovem model when the pore fluid viscosity is varied. The new profilometer recorder and transducer are described in detail as well as the microcomputer band playback system. Data obtained from the laboratory measurements are displayed.
Download or read book Acoustical and Engineering Properties of Sediments written by Donald J. Shirley and published by . This book was released on 1975 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of a program of in situ acoustical measurements in ocean sediments, an experimental investigation was started in order to examine the feasibility of measuring shear wave speed, shear wave attenuation, and bulk density by using instruments similar to the compressional wave profilometer developed previously. Measurements were made of the shear wave speed and attenuation in high porosity koalinite clay as the clay consolidated over a period of time. Experimential and theoretical investigation of the measurement of bulk density by acoustical means indicates that the radiation impedance of a driven piezoelectric ceramic transducer can be determined by measuring the electrical input to the transducer. Preliminary measurements of these parameters are reported. As an adjunct to the other measurements, physical properties of the sediments used in the laboratory measurements were determined and are reported.
Download or read book Laboratory and in Situ Sediment Acoustics written by Donald J. Shirley and published by . This book was released on 1977 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: During this reporting period, research was directed towards measuring sediment acoustic parameters in situ. Four field trips were made to use the ARL profilometer to make in situ sound speed measurements. Laboratory work continued to add the capability of measuring shear wave speed and acoustic impedance to the existing profilometer. Shear wave and compressional wave data measured in laboratory sediments are reported.
Download or read book Sediment Characterization Using in Situ Measurements of Acoustic Properties written by Justin Thomas Dubin and published by . This book was released on 2018 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three related studies associated with the acoustics of marine sediments were performed and described here. The first study was a direct exploration of the microscopic properties of marine sediment collected in the field. High-resolution images, acquired through scanning electron microscopy, are presented alongside sediment analysis and in situ sound speed data in order to better understand the affect microscopic geometries have on acoustic propagation in naturally occurring marine sediment. This microscopy work is followed by a description of the apparatus, methodology, and results from a field experiment conducted in a shallow water seagrass-bearing environment in which the acoustic properties of both the seagrass canopy and underlying sediment were measured in situ. The results are compared to predictions from several effective medium models to help explain the observed propagation behavior. The final study in this thesis describes acoustic directivity characterization for the compressional wave transducer probes used to collect in situ data presented in the previous studies as well as for a re-designed pair of prototype probes. These laboratory measurements are compared to both analytical and finite element models.
Download or read book Arbeitsgruppe Gro m rkte im deutschen St dtetag Landeshauptstadt M nchen Internationale Gro markttagung M nchen 1955 written by and published by . This book was released on 1955 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods and advances in marine geology and hydrodynamics environment written by Nan Wu and published by Frontiers Media SA. This book was released on 2024-01-29 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustics of in Situ and Laboratory Sediments written by Donald J. Shirley and published by . This book was released on 1978 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the period 1 January to 31 December, 1977, work under Contract N00014-76-C-0117 consisted of three parts: (1) in situ determination of compressional wave speed in ocean sediments using the ARL:UT profilometer; (2) development of transducers to measure shear wave and acoustic impedance parameters of sediments both in situ and in the laboratory; and (3) laboratory measurement of shear wave and compressional wave parameters of real and artificial sediments. Data obtained for the three parts of the program are reported.
Download or read book Laboratory and in Situ Measurement of Sound Velocity and Mass Physical Properties of Some Unconsolidated Marine Sediment Cores written by John Howard Southworth and published by . This book was released on 1971 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laboratory Measurements of Sound Speed and Attenuation of Water saturated Granular Sediments written by Theodore F. Argo and published by . This book was released on 2012 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: The propagation of acoustic waves through water-saturated granular sediments has been widely studied, yet existing propagation models can not adequately predict the speed and attenuation of sound across the range of frequencies of interest in underwater acoustics, especially in loosely packed sediments that have been recently disturbed by storms or wave action. Advances in modeling are currently dependent on experimental validation of various components of existing models. To begin to address these deficiencies, three well-controlled laboratory experiments were performed in gravity-settled glass beads and reconstituted sand sediments. Sound speed and attenuation measurements in the 0.5 kHz to 10 kHz range are scarce in the literature, so a resonator method was used to investigate a reconstituted sand sediment in this range. The literature contains laboratory and in situ measurements of sound speed and attenuation at higher frequencies, but existing models can not predict both the speed of sound and attenuation simultaneously in some sediments. A time-of-flight technique was used to determine the speed of sound and attenuation in monodisperse water-saturated glass beads, binary glass bead mixtures, and reconstituted sediment samples in the frequency range 200 kHz to 900 kHz to investigate the effect of sediment inhomogeneity. The effect of porosity, independent of changes in other sediment physical properties, has not been demonstrated in the experimental literature. Therefore, a fluidized bed technique was used to independently vary the porosity of monodisperse glass bead samples from 0.37 to 0.43 and a Fourier phase technique was used to determine the speed and attenuation of sound. Collecting these results together, measured sound speeds showed positive dispersion below 50 kHz while negative dispersion was observed above 200 kHz for some samples. Attenuation measurements showed an approximately f0̇5 dependence in the low frequency regime and an approximately f3̇5 dependence for large-grained samples in the high frequency regime. The laboratory experiments presented in this work demonstrate that both sound speed and attenuation in idealized loosely packed water-saturated sediments can not be simultaneously predicted by existing models within the uncertainties of the model input parameters, but the independent effect of porosity on sound speed can be predicted.
Download or read book High Frequency Seafloor Acoustics written by Darrell Jackson and published by Springer Science & Business Media. This book was released on 2007-08-02 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a research monograph on high-Frequency Seafloor Acoustics. It is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. It provides a critical evaluation of the data and models pertaining to high-frequency acoustic interaction with the seafloor, which will be of interest to researchers in underwater acoustics and to developers of sonars. Models and data are presented so as to be readily usable, backed up by extensive explanation. Much of the data is new, and the discussion in on two levels: concise descriptions in the main text backed up by extensive technical appendices.
Download or read book Physics of Sound in Marine Sediments written by Lloyd Hampton and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of sound transmissions through marine sediments is of extreme interest to both the United States civilian and Navy research communities. Both communities have conducted research within the field of this phenomenon approaching it from different perspectives. The academic research community has approached it as a technique for studying sedimentary and crustal structures of the ocean basins. The Navy research community has approached it as an additional variable in the predictability of sound trans mission through oceanic waters. In order to join these diverse talents, with the principal aim of bringing into sharp focus the state-of-the-science in the problems relating to the behavior of sound in marine sediments, the Office of Naval Research organized and sponsored an invited symposium on this subject. The papers published in this volume are the results of this symposium and mark the frontiers in the state-of-the-art. The symposia series were based on five research areas identified by ONR as being particularly suitable for critical review and for the appraisal of future research trends. These areas include: 1. Physics of Sound in Marine Sediments, 2. Physical and Engineering Properties of Deep-Sea Sediments, 3. The Role of Bottom Currents in Sea Floor Geological Processes, 4. Nephelometry and the Optical Properties of the Ocean I'laters, S. Natural Gases in Marine Sediments and Their Mode of Distribution. These five areas also form some of the research priorities of the ONR program in Marine Geology and Geophysics.
Download or read book Sound Velocity Elasticity and Related Properties of Marine Sediments North Pacific written by Edwin Lee Hamilton and published by . This book was released on 1969 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Properties of Sediments written by Loyd Hampton and published by . This book was released on 1967 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deep Sea Sediments written by Anton Inderbitzen and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of its continuing program to stimulate superior basic research in the marine environment, the Office of Naval Research, Ocean Science and Technology Division, sponsored a series of closed seminar-workshops in 1972-1973. Each seminar focused upon one re search area of marine geology which is relatively new and in need of a critical evaluation and accelerated support. The subjects areas chosen for the seminars were: 1. natural gases in marine sediments and their mode of distribution, 2. nephelometry and the optical properties of ocean waters, 3. physical and engineering properties of deep-sea sediments, and 4. physics of sound in marine sediments. The objectives of each seminar-workshop were to bring into sharper focus the state-of-the-science within each subject area, to effect some degree of coordination among the investigators working within each of these areas and to provide the Ocean Science and Technology Division guidance for national program support. This volume.contains most of the papers presented at the semi nar on the physical and engineering properties of deep-sea sediments. The seminar was held at Airlie House, Airlie, Virginia on April 24- 27, 1973 and was organized and chaired by A. Inderbitzen. The at tendees were invited from among the leading investigators in this field from both the engineering and scientific disciplines. Each attendee was requested to prepare a paper within his area of spe ciality.
Download or read book Sound Velocity Elasticity and Related Properties of Marine Sediments North Pacific 3 Prediction of In Situ Properties written by E. L. Hamilton and published by . This book was released on 1969 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the acoustic and related properties of the sea floor in three major environments of the North Pacific: the continental terrace (shelf and slope), abyssal plain (turbidite), and abyssal hill (pelagic). Discussions cover the correction of laboratory to insitu values, and the prediction of in situ values. The methods developed are applicable to other areas and sediments.
Download or read book In Situ Sediment Attenuation and Sound Velocity Ratio Measured in Shallow Water at the Quinault Range written by R. L. Allman and published by . This book was released on 1984 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
