| Source and Path Calibration in Regions of Poor Crustal Propagation Using Temporary, Large-Aperture, High-Resolution Seismic Arrays (Postprint). Annual Report 3 |
04 Jun 2012 |
14 pages |
| Authors:
John L Nabelek; Jochen Braunmiller; Patrick W Monigle; N S Carpenter; W S Phillips; OREGON STATE UNIV CORVALLIS
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 | Broadband seismic data acquired during the Hi-CLIMB experiment were used to study seismic events and path propagation in the Nepal Himalaya and the south-central Tibetan Plateau. Automated hypocenter locations in south-central Tibet were finalized. Refinements included an update of the model used for location based on high-quality manual P- and S-arrival picks from several strong events well recorded at close distances as well as the additional removal of spurious events. ... |
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| Investigation of an Unusually Shallow Earthquake Sequence in Mogul, NV from a Discrimination Perspective (Postprint): Annual Report 1 |
09 May 2012 |
12 pages |
| Authors:
Ileana M Tibuleac; Glenn Biasi; David von Seggern; John G Anderson; Danielle Molisee; NEVADA UNIV RENO NV
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| Distinction between very shallow (1-4 km deep) earthquakes and underground nuclear explosions remains an important issue in discrimination research. This is because very shallow earthquakes are seldom well-recorded and documented. As a consequence, their source parameters, scaling and their local and regional propagation characteristics are not well understood. Thus, unlike for deeper events, the effectiveness of the discrimination algorithms when applied to unusually shallow earthquakes has been only rarely determined. ... |
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| Reduction in Susceptibility of MOS Devices to Radiation- and Electrically-Induced Defects |
01 May 2012 |
38 pages |
| Authors:
Len Trombetta; HOUSTON UNIV TX
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| The goal of this project was to identify fabrication techniques by which the susceptibility of Metal-Oxide-Semiconductor devices to theNegative-Bias-Temperature Instability (NBTI) and to radiation damage could be reduced. To that end, two techniques were attempted. In the first attempt, helium ions were implanted into the oxide layer of the devices in an attempt to frustrate the formation of defects via hydrogen depassivation. This attempt was not successful, perhaps because defects ... |
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| Heave and Pitch Dynamics of Shallow Draft Surface Vehicles |
10 Apr 2012 |
26 pages |
| Authors:
Roger S Cortesi; Owen Thorp; George Piper; NAVAL RESEARCH LAB WASHINGTON DC
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| This project's objective is to develop a model of the heave and pitch dynamics for a shallow draft surface vehicle. The model developed uses a novel approach of representing the ship dynamics in the frequency domain. The model is based on theoretical first-principles involving highly nonlinear equations that depend on the water wave frequency. Compared to time domain modeling and simulation approaches, the frequency domain model provides greater insight to ... |
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| Airborne Lidar Detection and Characterization of Internal Waves in a Shallow Fjord |
Jan 2012 |
16 pages |
| Authors:
James H Churnside; Richard D Marchbanks; Jennifer H Lee; Joseph A Shaw; Alan Weidemann; Percy L Donaghay; NAVAL RESEARCH LAB STENNIS DETACHMENT STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| A dual-polarization lidar and photography are used to sense internal waves in West Sound, Orcas Island, Washington, from a small aircraft. The airborne lidar detected a thin plankton layer at the bottom of the upper layer of the water, and this signal provides the depth of the upper layer, amplitude of the internal waves, and the propagation speed. The lidar is most effective when the polarization filter on the receiver ... |
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| Experimentally-Based Ocean Acoustic Propagation and Coherence Studies |
Jan 2012 |
15 pages |
| Authors:
Timothy F Duda; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
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| The long-term goal is to better understand fluctuating sound propagation in two distinct ocean acoustic regimes: Stratified shallow water, where sound is highly bottom interacting, and the temperate deep-ocean sound channel. Acoustic field fluctuations have time scales varying from less than a minute to hours, and horizontal spatial scales from tens of meters to kilometers, comparable to processing time scales and system spatial scales, and thus impact exploitation of underwater ... |
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| Tracking Bottom Waters in the Southern Adriatic Sea Applying Seismic Oceanography Techniques |
05 Oct 2011 |
10 pages |
| Authors:
Sandro Carniel; Andrea Bergamasco; Jeffrey W Book; Richard W Hobbs; Mauro Sclavo; Warren T Wood; NAVAL RESEARCH LAB STENNIS DETACHMENT STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| We present the first results from the seismic oceanography (SO) cruise ADRIASEISMIC where we successfully imaged thermohaline fine structures in the shallow water environment (50-150 m) of the southern Adriatic Sea during March 2009 using a compact two Gl-gun seismic source. The SO observations are complemented with traditional oceanographic and micro-structure measurements and show that SO can operate over almost the entire water column except (in our experimental layout) for ... |
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| Modeling Wind Wave Evolution from Deep to Shallow Water |
30 Sep 2011 |
10 pages |
| Authors:
Tim T Janssen; Thomas H Herbers; Gerbrant Ph van Vledder; SAN FRANCISCO STATE UNIV CA
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| Ocean waves are an important aspect of upper ocean dynamics, in particular on the shallow continental shelves and in coastal areas. The long-term objective of this work is to advance modeling capability in such coastal areas by improving model representations of effects associated with nonlinearity, inhomogeneity, and dissipation. The specific objectives of the present work are (1) to develop and implement an efficient and scalable approximation for the nonlinear quadruplet ... |
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| Arterial Gas Embolism Induced Ageusia (Case Report) |
Jul 2011 |
5 pages |
| Authors:
Blake D Lollis; ROBERT JOHNSON; Harlan M Walker; SCHOOL OF AEROSPACE MEDICINE WRIGHT PATTERSON AFB OH
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| This article details a previously unreported arterial gas embolism (AGE) clinical presentation. A military aircrew candidate water survival course trainee lost his sense of taste (ageusia) after only a few compressed air breaths and ascending from the shallow depth of 4 ft. Ageusia was his only AGE sign or symptom. Rapidly diagnosing and treating AGE and other decompression illnesses is essential for positive patient outcomes and requires understanding the anatomic ... |
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| Regional Seismic Wave Propagation in the Middle East |
MAY 2011 |
66 pages |
| Authors:
Keith F. Priestley; CAMBRIDGE UNIV (UNITED KINGDOM) DEPT OF EARTH SCIENCES
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| Two manuscripts were written, the first "Teleseismic evidence for a break-off slab beneath NE Iran Continental Collision Zone" discusses initial work with Iranian colleagues to examine the upper mantle structure beneath the NE Iran continental collision zone. The data for this study were recorded by 19 three component broad-band seismic stations operated from August 2006 to February 2008 along a profile from the center of the Iranian Plateau, near Yazd, ... |
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| LES Modeling of Lateral Dispersion in the Ocean on Scales of 10 m to 10 km |
30 MAR 2011 |
2 pages |
| Authors:
Marie-Pascale Lelong; NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA
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| The long-term goal of this effort is to develop scalable, physically based parameterizations for lateral mixing in the stratified ocean on scales of 0.1-10km that can be implemented in larger-scale ocean models. These parameterizations will incorporate the effects of local ambient conditions including latitude, mean stratification and mesoscale flows. Another ultimate goal is to develop a more comprehensive picture of horizontal and vertical mixing processes in the ocean. |
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| Development of Systematic Approaches for Calibration of Subsurface Transport Models Using Hard and Soft Data on System Characteristics and Behavior |
02 FEB 2011 |
10 pages |
| Authors:
Tissa H. Illangasekare; Toshihiro Sakaki; COLORADO SCHOOL OF MINES GOLDEN
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| This research seeks to extend and combine tools for parameter estimation and geostatistical simulation for use with groundwater flow and transport models used by the Army. Funds were added to include a research task to investigate the soil moisture distribution in the shallow subsurface affected by buried objects and heterogeneity in the soil under various surface conditions. The primary aims of the project are to: (1) develop an improved understanding ... |
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| Transfer of CVD-Grown Monolayer Graphene onto Arbitrary Substrates |
Jan 2011 |
10 pages |
| Authors:
Ji W Suk; Alexander Kitt; Carl W Magnuson; Yufeng Hao; Samir Ahmed; Jinho An; Anna K Swan; Bennett B Goldberg; Rodney S Ruoff; TEXAS UNIV AT AUSTIN DEPT OF MECHANICAL ENGINEERING
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| Reproducible dry and wet transfer techniques were developed to improve the transfer of large-area monolayer graphene grown on copper foils by chemical vapor deposition (CVD). The techniques reported here allow transfer onto three different classes of substrates substrates covered with shallow depressions, perforated substrates, and flat substrates. A novel dry transfer technique was used to make graphene-sealed microchambers without trapping liquid inside. The dry transfer technique utilizes a polydimethylsiloxane frame ... |
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| Hydrodynamics in Shallow Estuaries with Complex Bathymetry and Large Tidal Ranges |
30 SEP 2010 |
7 pages |
| Authors:
Stephen G. Monismith; STANFORD UNIV CA DEPT OF CIVIL AND ENVIRONMENTAL ENGINEERING
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| Out interest is in understanding how stratification, turbulence, and circulation interact in estuarine flows. It is our hypothesis that the role of stratification in suppressing turbulence is central to this interaction. Thus, a major focus of our work is in finding simple relationships (if possible) connecting local flow conditions to turbulence state and turbulent fluxes. We are also interested in using field data from complex estuarine flows to test circulation ... |
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| Acoustic Blind Deconvolution in Uncertain Shallow Ocean Environments |
30 SEP 2010 |
8 pages |
| Authors:
David R. Dowling; MICHIGAN UNIV ANN ARBOR DEPT OF MECHANICAL ENGINEERING
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| The overall long-term goal for this project is to develop engineering tools that are useful to the Navy as it operates in uncertain, partially-known, or unknown ocean environments. During the last year, this project has focused on further determining the utility of a time-reversal-based technique for blind deconvolution of recorded sounds broadcast by a remote source with emphasis on determining if and how the results might be used for tracking ... |
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| Assessment of Hydroacoustic Propagation Using Autonomous Hydrophones in the Scotia Sea |
Sep 2010 |
9 pages |
| Authors:
Haru Matsumoto; Del R Bohnenstiehl; Robert P Dziak; Robert W Embley; Minkyu Park; OREGON STATE UNIV NEWPORT OR COOPERATIVE INST FOR MARINE RESOURCES STUDIES
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| The remote area of the Atlantic Ocean near the Antarctic Peninsula and the South Scotia Sea is a region where acoustic surveillance by International Monitoring System hydrophones is at best limited. Sound originating in this area is either blocked or hindered by the South Georgia, South Sandwich Islands and the associated seafloor ridge system, making the region a potential hydroacoustic blind spot. To investigate the sound propagation and interferences affected ... |
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| An Ocean Sensor Array to Detect Small-Scale Variability |
Jul-2009 |
5 pages |
| Authors:
Janet Sprintall; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
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| The specific objectives of this DURIP project were to provide direct measurements of velocity and currents in narrow straits with shallow sill depths in order to: (1) Examine the relative roles of the tidal and longer timescale flows in the generation and evolution of the small-scale dynamical flow features in straits; (2) Determine how the small-scale features evolve with observed across- and along-strait variation in sea level and the corresponding ... |
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| Interface Conditions for Hybrid RANS/LES Simulations of Complex and Compressible Flows |
06-Mar-2009 |
31 pages |
| Authors:
Ugo Piomelli; Elias Balaras; MARYLAND UNIV COLLEGE PARK DEPT OF MECHANICAL ENGINEERING
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| We have demonstrated the applicability of synthetic turbulence coupled with the controlled-forcing method to generate eddies at the interface between RANS and LES in hybrid calculations. We obtained shorter transition regions and improved model accuracy. Realistic turbulence can be generated within 5 boundary-layer thicknesses of the RANS/LES interface even in cases in which the data supplied by the RANS is inaccurate, or the assumptions on which the forcing is based ... |
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| Demonstration Mobile Seismic Unit for Detecting Subterranean Passageways |
JAN 2009 |
165 pages |
| Authors:
Neil Anderson; Niaklas Putman; Steve Grant; A. Nasseri-Moghaddam; Peng Xie; Oleg Kovin; Preetam Modur; Colin Stagner; Evginey Torgashov; MISSOURI UNIV-ROLLA
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| A mobile seismic unit for detecting shallow subterranean passageways was designed and constructed. The unit was successfully field tested and/or demonstrated at six known tunnel sites (tunnel diameters ranged from 0.6 4.0 m; tunnel depths ranged from 0.3 1.5 m). The locations of the six tunnels were determined with an average accuracy of 0.5 m; on average, one false positive was identified on each of the six test site data ... |
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| Environmental Factors Affecting Aquatic Plant Growth Potential in Marinuka Lake, Wisconsin |
Dec-2008 |
14 pages |
| Authors:
William F James; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
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| Submersed aquatic macrophytes play an important role in stabilizing sediment from resuspension, sequestering nutrients, and reducing algal growth in shallow lakes. Loss of vegetation is usually accompanied by changes in stable state to one characterized by higher turbidity, low light penetration, and frequent noxious algal blooms. Aquatic vegetation once played an important role in stabilizing the sediment and providing important fish and water fowl habitat in Marinuka Lake, Wisconsin. However, ... |
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| Momentum Exchange Near Ice Keels in the Under Ice Ocean Boundary Layer |
01 MAR 2008 |
51 pages |
| Authors:
John C. Bleidorn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis describes momentum exchange in the under-ice ocean boundary layer near ice keels. Understanding ice-ocean momentum exchange is important for accurate predictive ice modeling. Due to climate change, increased naval presence in the Arctic region is anticipated and ice models will become necessary for tactical and safety reasons. Measurements took place in March 2007 in the Beaufort Sea at the Applied Physics Laboratory Ice Station sponsored by the U.S. ... |
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| Spectral Studies of Shallow Earthquakes and Explosions: Implications for P/S Energy Partitioning, Stress Drop, and Discrimination |
16-Jan-2008 |
35 pages |
| Authors:
Peter Shearer; Bettina Allmann; CALIFORNIA UNIV SAN DIEGO LA JOLLA INST OF GEOPHYSICS AND PLANETARY PHYSICS
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| We compute and analyze P-wave spectra from 18,101 earthquakes and 1770 explosions recorded by 196 broadband seismic stations in southern California at epicentral distances up to 100 km. We use an online waveform database stored on a RAID system at Caltech, which provides complete access to the Southern California Seismic Network (SCSN) seismogram archive. We compute spectra using 1.28s noise and signal windows, positioned immediately before and after the P ... |
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| Reflective Light Modulation by Cephalopods in Shallow Nearshore Habitats |
Jan-2008 |
|
| Authors:
Roger T Hanlon; MARINE BIOLOGICAL LAB WOODS HOLE MA
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 | The central question is: what are the optical principles upon which crypsis is achieved by opaque organisms in shallow, nearshore marine habitats? Camouflage mechanisms are not well known despite the general misconception that they are. Moreover, quantification of camouflage (especially of opaque organisms) is particularly wanting. We have three objectives: (1) Acquire imagery (camouflaged animals and their backgrounds) and corresponding irradiance data from coral reef and temperate rock reef environments. ... |
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| Electromagnetic Models and Inversion Techniques for Multiple UXO Discrimination |
31-Dec-2007 |
23 pages |
| Authors:
Jin A Kong; Bae-Ian Wu; Beijia Zhang; Hongsheng Chen; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
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| Recovery of buried unexploded ordnance (UXO) is very slow and expensive due to the high false alarm rate created by clutter. Electromagnetic induction (EMI) has been shown to be a promising technique for UXO detection and discrimination. We use the EMI response of buried targets to identify or classify them. Given that now a more complete model of the measurable response of a buried UXO is implemented, this study proceeds ... |
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| Pulmonary Effects of Eight-Hour MK 16 MOD 1 Dives |
OCT 2007 |
10 pages |
| Authors:
B. Shykoff; NAVY EXPERIMENTAL DIVING UNIT PANAMA CITY FL
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| Most conclusions that we have reached about pulmonary oxygen toxicity at an oxygen partial pressure of 1.3 atm have been obtained from shallow dives with 100% oxygen. To confirm that results are valid for the MK 18 MOD 1, we compared effects of 8-hour dives at a depth of 50 feet (50% oxygen) to those previously attained at 12 to 14 feet. Seventeen U.S. Navy divers dove underwater in the ... |
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| Sediment Transport by Internal Waves in EUROSTRATAFORM |
30 SEP 2007 |
6 pages |
| Authors:
David A. Cacchione; COASTAL AND MARINE ENVIRONMENTS RENO NV
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| This project investigates the role that internal waves might have in sediment transport in the EUROSTRATAFORM project. The overall long-term project goal is to determine the modes and mechanisms of transport of bottom and suspended sediment by internal waves. The specific goal of this work is to use available and newly acquired data on internal waves and density structure in the Adriatic Sea to investigate internal wave effects on sedimentation. ... |
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| Quantitative Estimation of Variability in the Underwater Radiance Distribution (RadCam) |
30 Sep 2007 |
10 pages |
| Authors:
Marlon R Lewis; Scott D McLean; SATLANTIC INC HALIFAX (CANADA)
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| A significant source of uncertainty in the prediction of the apparent optical properties of the ocean is the geometrical distribution of the radiance field and its variation with respect to time and space; this uncertainty directly affects attempts to use measurements of reflectance and attenuation for the diagnosis of ocean constituents. Uncertainties in the time and depth dependent variations in the radiance distribution, and their sources of variation, propagate as ... |
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| Laboratory Study of Wind Effect on Runup over Fringing Reefs. Report 1. Data Report |
JUL 2007 |
83 pages |
| Authors:
Zeki Demirbilek; Okey G. Nwogu; Donald L. Ward; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| The report describes experimental data obtained from a wind-wave flume study conducted August-September 2006 at the University of Michigan in Ann Arbor, MI. The study objectives were two-fold: to quantify wind effects on wave runup on fringing reefs of the Pacific Island of Guam and to obtain detailed wave data along a complex reef system consisting of steep slopes and shallow areas for validating wave breaking, dissipation, wave setup and ... |
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| Demonstration of Airborne Wide Area Assessment Technologies at the Toussaint River, Ohio |
17 APR 2007 |
65 pages |
| Authors:
Jack Foley; David Wright; SKY RESEARCH ASHLAND OR
|
| The former Erie Army Depot, Ottawa County, Ohio, is located along the western shore of Lake Erie. This site and the associated impact areas are classified by the United States Government as Formerly Used Defense Sites (FUDS) and was formerly used for artillery testing, resulting in impact areas on land and in Lake Erie. This demonstration utilized Helicopter Multi-Towed Array Detection System (MTADS) Magnetometry (HeliMag) technology, a wide area assessment ... |
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| Attenuation of Ocean Waves by Ripples on the Seafloor |
MAR 2007 |
3 pages |
| Authors:
Robert T. Guza; William O'Reilly; SCRIPPS INST OF OCEANOGRAPHY LA JOLLA CA INTEGRATIVE OCEANOGRAPHY DIV
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| Dissipation of hurricane waves over a broad, shallow shelf were observed during the SAX04/Ripples Experiment on the Florida Panhandle Gulf Coast. Nearly complete bottom dissipation of hurricane swell waves occurred in Apalachee Bay, where the shelf is approximately 200km wide. On the narrower 85km shelf off Fort Walton Beach, peak swell energy levels decreased by approximately a factor of 3, but were still energetic enough during Hurricane Ivan to destroy ... |
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| Analytical and Observational Studies of Internal Solitary Waves in the Yellow Sea |
NOV 2006 |
15 pages |
| Authors:
M. Teixeira; A. Warn-Varnas; J. Apel; J. Hawkins; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| This article presents findings regarding the origination & evolution of a large train of internal solitary waves as observed through Synthetic Aperture Radar (SAR). The internal wave train under study propagates into deeper waters away from the coast & most important appears to be generated at a well defined point along a steep topographic variation. The shallow bottom topography revealed itself in the SAR image & provided the opportunity to ... |
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| Remote Sensing of the Refractive Environment Above the Marine Stratocumulus-Topped Boundary Layer |
SEP 2006 |
85 pages |
| Authors:
Dennis T. Derley; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Electro-Magnetic propagation paths are subject to refraction as they travel through moisture and temperature gradients found within the inversion layer at the top of the stratocumulus-topped marine boundary layers (STBL). The NPS Meteorology Department is developing an automated program called SEMEO (Satellite Electro-Magnetic Electro-Optical) that will use remote sensors to estimate the cloud-top height, and characterize the ducting conditions over large regions. In addition to estimating the location and strength ... |
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| Ocean Prediction with the Hybrid Coordinate Ocean Model (HYCOM) |
2006 |
18 pages |
| Authors:
Eric P. Chassignet; Harley E. Hurlburt; Ole M. Smedstad; George R. Halliwell; Patrick J. Hogan; Alan J. Wallcraft; Rainer Bleck; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| This chapter provides an overview of the effort centered on the HYbrid Coordinate Ocean Model (HYCOM) to develop an eddy-resolving, real-time global and basin-scale ocean prediction system in the context of the Global Ocean Data Assimilation Experiment (GODAE). The long-term goal is an eddy-resolving, fully global ocean prediction system with data assimilation based on HYCOM to be transitioned to the Naval Oceanographic Office at 1/12 degree equatorial resolution in 2007 ... |
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| Dialogue Structure and Pronoun Resolution |
2006 |
7 pages |
| Authors:
Joel R. Tetreault; James F. Allen; ROCHESTER UNIV NY DEPT OF COMPUTER SCIENCE
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| This paper presents an empirical evaluation of a pronoun resolution algorithm augmented with discourse segmentation information. Past work has shown that segmenting discourse can aid in pronoun resolution by making potentially erroneous candidates inaccessible to a pronoun's search. However, implementing this in practice has been difficult given the complexities associated with deciding on a useful scheme and then generating the segmentation reliably. In our study, we investigate whether or not ... |
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| Prediction of Shallow Footing Settlements on Cohesionless Materials from Seismic Testing |
DEC 2005 |
271 pages |
| Authors:
Andrew J. Sheehan; TEXAS UNIV AT AUSTIN
|
| The practice of predicting settlements of shallow foundations has evolved in the past 50 years, but the basic principles and obstacles in making such predictions remain the same. First, the engineer must accurately characterize the soil beneath the proposed foundation. Second, the engineer must choose an analytical technique to model the behavior of that soil under the load. Since settlement, rather than bearing capacity, is most often the controlling design ... |
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| Parameterizing the High Frequency Evolution of Nearshore Waves in a Nonlinear Wave Model |
07 OCT 2005 |
100 pages |
| Authors:
Kacey Edwards; Jayaram Veeramony; James Kaihatu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Waves propagating through the shoaling and surf zones exhibit properties not characteristic of linear sinusoidal waves. Nonlinear wave-wave interactions act to transfer energy between the different harmonics of the peak frequency; this transfer is most apparent from the peak frequency of the spectrum to higher harmonics of the peak. As a result of these nonlinear interactions, the shape of a wave is altered making it asymmetrical vertically (skewness) and horizontally ... |
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| Nonlinear Internal Waves in The South China Sea |
28 SEP 2005 |
7 pages |
| Authors:
Ming-Kuang Hsu; Antony K. Liu; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GREENBELT MD GODDARD SPACE FLIGHT CENTER
|
| ENVISAT ASAR, RADARSAT-I and ERS/2 SAR images have been used to study the internal waves in the north part of South China Sea (SCS). Based on the internal wave distribution map compiled film SAR images collected in the last 5 years. almost all internal waves in the SCS are propagating westward and are generated from the shallow topography or sills in the Luzon Strait. However, from ENVISAT ASAR images collected ... |
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| Gopher Tortoise Nest Detection at Camp Shelby, Mississippi |
SEP 2005 |
56 pages |
| Authors:
Jr. Bennett Hollis H.; Janet E. Simms; Lewis B. Smithhart; Michael L. Hargrave; Tad Britt; Harold Balbach; Don Pitts; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
|
| ABSTRACT: Declining populations of the gopher tortoise (Gopherus polyphemus) have prompted management efforts including methods to increase egg clutch survival. Estimates are that as many as 88 percent of all clutches are being destroyed by predation. The most popular protection method has been to locate the clutch and protect it from predation with a metal cage or hardware screen. Locating the clutch without damaging or extensively disturbing the eggs requires ... |
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| Broadband Electromagnetic Detection and Discrimination of Underwater UXO |
31 AUG 2005 |
31 pages |
| Authors:
Bill San Filipo; I. J. Won; GEOPHEX LTD RALEIGH NC
|
| The two aspects of this research consisted of computer modeling and analysis, and experiments in shallow seawater. The methodology for the computer modeling was to develop analytic algorithms for special cases that would provide insight as to the fundamental physics related to the EMI response of a metal object when immersed in a conductive host medium as well as quantify the effects of seawater that would allow prediction of the ... |
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| High Resolution Modeling of the Gulf of Mexico |
JUL 2005 |
4 pages |
| Authors:
Patrick J. Hogan; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| An advanced, high-resolution numerical ocean model is employed to investigate the dynamics and physical characteristics of the deep and shallow circulation in the Gulf of Mexico. The resolution of the ocean model (approx. 4 kilometers) and revolutionary hybrid (quasi-isopycnic) vertical coordinate makes it an excellent candidate to form the ocean model core of an ocean acoustic tomography program that can provide near real-time subsurface ocean data to augment satellite data ... |
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| Ocean Circulation and Exchanges Through the Bering Sea: 1979-2001 Model Results |
JUN 2005 |
115 pages |
| Authors:
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| A model has been developed and run with sufficiently high resolution (^9 km and 45 levels) and a large enough spatial domain to allow for realistic representation of flow through the narrow and shallow straits in the Bering Sea region. This is potentially important for quantification of long-term mean and time-dependent ocean circulation, and water mass and property exchanges between the Pacific and Arctic oceans. The mean modeled circulation in ... |
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| Inversion for Subbottom Sound Velocity Profiles in the Deep and Shallow Ocean |
FEB 2005 |
|
| Authors:
Luiz L. Souza; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| We investigate the application of acoustic measurement sin the ocean to measurer the sound velocity profile (svp) in the subbottom. For the deep water ocean, an exact method based on the Gelfand-Levitan integral equation is evaluated. The input data is the complex plane-wave reflection coefficient. We apply the method to experimental acoustic data and estimate the reflection coefficient and the svp in the seabed. |
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| Detecting Near-UV and Near-IR Wavelengths With the FOVEON Image Sensor |
DEC 2004 |
79 pages |
| Authors:
Cheak S. Fai; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS
|
| Traditionally, digital imaging systems rely on the use of dedicated photodetectors to capture specific wavelengths in the visible spectrum. These photodetectors, which are commonly made of silicon, are arranged as arrays to capture the red, green and blue wavelengths. The signal captured by the individual photodetectors must then be interpolated and integrated to obtain the closest color match and the finest possible resolution with reference to the actual object. The ... |
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| A Simulation Model on the Competition for Light of Meadow-forming and Canopy-forming Aquatic Macrophytes at High and Low Nutrient Availability |
SEP 2004 |
79 pages |
| Authors:
Elly P. Best; Gregory A. Kiker; William A. Boyd; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
|
| A simulation model has been developed that focuses on the ability of two competing submersed macrophytes, meadow-forming and canopy-forming, to maintain their biomass under different environmental conditions. Vallisneria americana (American wildcelery) serves as the example for meadow-forming plants and Stuckenia pectinata (until recently known as Potamogeton pectinatus or sago pondweed) for canopy-forming plants. The model can be used to predict changes in species composition of submersed vegetation as a result ... |
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| The Use of Hydroacoustic Phases for the Detection of Oceanic Events: Observations and Numerical Modeling |
JUL 2004 |
63 pages |
| Authors:
Catherine DE Groot-Hedlin; Donna Blackman; John Orcutt; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
|
| Hydroacoustic monitoring of the Comprehensive Nuclear Test Ban Treaty (CTBT) requires the ability to detect and locate phenomena that give rise to acoustic signals. An improved understanding of the coupling of seismic energy to acoustic energy is necessary to improve location estimates of earthquakes and volcanic eruptions. Using known variations in near-source bathymetry, the authors demonstrated that scattering of seismic to acoustic energy at a rough seafloor yields the approximate ... |
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| Demonstration Project on Dredging and Marsh Development Using a Flexible-Discharge Dustpan Dredge at Head of Passes/Southwest Pass Mississippi River |
JUN 2004 |
82 pages |
| Authors:
Timothy L. Welp; James E. Clausner; Doug Thompson; Joaquin Mujica; George Boddie; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICSLAB
|
| The navigation channel of the Mississippi River in the vicinity of the Head of Passes (HOP) downstream of New Orleans is an area where significant dynamic shoaling occurs. During the traditional high-water period in the spring, the shoaling in this area occurs rapidly and can represent a hazard to deep- draft vessel traffic. The shoaling must be removed rapidly to maintain adequate channel depth. Currently, dredging of the channel at ... |
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| Petrologic and Microstructural Constraints on Focused Melt Transport in Dunites and Rheology of the Shallow Mantle |
JUN 2004 |
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| Authors:
Michael G. Braun; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Observations at mid-ocean ridges indicate that magmas are focused to the ridge axis by a network of porous dunites in near chemical isolation. This thesis investigates several of the outstanding questions regarding the mechanisms of melt transport and its effects on the shallow mantle. Chapter 1 details the current understanding of melt migration from observations at mid- ocean ridges and ophiolites. Chapter 2 uses the size distribution and abundance of ... |
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| A Photoelastic Study of Cracking in Motor Grain Models |
21 MAY 2004 |
11 pages |
| Authors:
C. W. Smith; J. D. Hansen; VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENGINEERING SCIENCE AND MECHANICS
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| By capitalizing on observed similarities between the cracked finned model and a cracked cylinder when placing the fin top at the inner edge of the cylinder, estimates were made by assuming a plane strain solution for the finned model in finite length models. Based upon the aforementioned limited results, use of a modified plane strain solution appears to yield a slightly conservative prediction for long shallow cracks to significantly conservative ... |
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| Environmental Mitigation Ranges around Australia |
FEB 2004 |
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| Authors:
Paul Clarke; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA) MARITIME OPERATIONS DIV
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| URS Australia is currently writing "Environmental Management Plan for Australian Maritime Exercise Areas" for the ADF. To help URS, the MOD within DSTO has modeled the expected received sound pressure levels for a number of different environments and sonar frequencies around Australia. The maximum ranges the sound pressure levels dropped below 182 and 160 dB were then calculated for a number of different sonars operating at levels indicative of or ... |
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| Continuous Treatment of Low Levels of TNT and RDX in Range Soils Using Surface Liming |
FEB 2004 |
24 pages |
| Authors:
Philip G. Thorne; Thomas F. Jenkins; Michael K. Brown; ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
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| Significant quantities of residual energetics are deposited on surface soils at live-fire ranges. Most of these residues come from bulk composition left over following low-order detonations. Of particular concern is RDX, which is environmentally persistent and mobile, and can therefore lead to groundwater pollution. Base hydrolysis can be used to rapidly decompose TNT and RDX in aqueous solutions. Hydrolysis of TNT produces soluble and insoluble polymers, while hydrolysis of RDX ... |
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