Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. William K. Dewar, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed Sept. 23, 2005). Document formatted into pages; contains xi, 61 pages. Includes bibliographical references.

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): D. Benjamin Reeder, Mary Batteen. Includes bibliographical references (p. 119-121). Also available online.

The phenomena of seabed bathymetric changes in Dundee harbour, eastern Scotland have been investigated, by use of archive bathymetric data. The bathymetric data were available from the Dundee Port Authority, from its past annual harbour maintenance programmes during the period of 1989 to 1993. Archive bathymetric data are seen as under-utilised, after being used for their intended purposes. A methodology was therefore developed to use sequential bathymetric data to estimate the deposition and erosion of sediment over a period of time. This is in the form of a systematic procedure of processing for comparison of data from different dates. The comparison or differencing of bathymetric data in their original form cannot be directly applied. This would require each data point to be located at spatially common positions (i.e. grid points) and could be achieved only through interpolation. A procedure known as 'gridding' is instead used to prepare depths at the spatially fixed points or nodes. Six different methods of interpolation have been examined and trial computations using a common data subset for each individual method conducted. The results of the interpolation were often substantially different from one method to another. A technique known as the Blending Interpolation Technique is proposed to overcome the uncertainty in depth interpolation. Computer programs were specifically written for this study and for the visualisation of the phenomena of deposition and erosion, use was made of the available UNIRAS software package. The methodology and procedures of this study are not only applicable for an estuarine harbour environment, but are also equally applicable to any areas such as large reservoirs, lakes or coastal ports and harbours, that are continuously affected by the phenomena of sedimentation and erosion, where their estimation and quantification are of critical importance. This study, however, has demonstrated the usefulness of the Blending Interpolation Technique which is seen as a future tool to detect, monitor and quantify seabed changes, in particular where bathymetric data of the same area are available from different dates. It also serves to prolong the usefulness of archive bathymetric data kept for an area.

This study is concerned with the fracture characteristics of RQT 701; a possible contender for the replacement of HY 100, the existing 690MNm-2 (100,000psi) strength level Naval quality steel. RQT 701 is a low nickel, boron containing quenched and tempered steel which is less expensive than HY 100 due to a lower nickel content. The hardenability is maintained by the boron addition. The preliminary testing of RQT 701 showed a variation in the impact transition temperature through the thickness of the plate. This study examines the possible causes of this variation in impact properties and makes a full assessment of the mechanical properties of RQT 701. A full metallographic investigation has been carried out using quantitative metallography, scanning electron microscopy and transmission electron microscopy. The effect of heat treatment on the steel's hardenability and mechanical properties has been studied so that suggestions to produce optimum properties of RQT 701 could be made. A full fractographic study has also been undertaken. The relationship between fracture characteristics, microstructure and hardenability has been discussed. A parallel investigation of HY 100 plate has been carried out. A comparison between the microstructures and fracture properties has been made and the relative merits of the two steels discussed.

An outline of the inshore submarine geology of the south western coast of southern Africa is presented. The study is derived from diamond prospecting operations carried out between 1964 and 1970 in the shallow waters between Walvis Bay in South West Africa and the Olifants River mouth in Namaqualand, Republic of South Africa - a distance of approximately 1 000 km (600 miles). The area can be conveniently subdivided into three regions from north to south: (i) Tidal Diamond's Concession (T.D.C.) from Sandwich Harbour to Hottentot Bay. (ii) Marine Diamond Corporation's Concession (M.D.C.) from Luderitz to the mouth of the Orange River. (iii) Southern Diamond's Concession (S.D.C.) from the Orange River mouth to the mouth of the Olifants River.

The Entente powers began World War I without any formal anti-submarine countermeasures. However, the Entente developed countermeasures through trial and error over time. Success was moderate until America joined the war. with America came the arrival of subchasers to the Mediterranean Theater of Operations. This highly specialized vessel helped turn the tide against U-boats. a true counter to the U-boat threat in the Mediterranean did not come until October 2, 1918 with the bombardment of Durazzo. This thesis discusses the development of Entente anti-submarine capabilities and illustrate how America's contribution led to success. a detailed analysis of the rarely discussed bombardment of Durazzo is included using archival documents.

As low-lying areas, deltas are sensitive to changes associated with advance taking place on the land and in the ocean. The pattern of change in shoreline positions over time can be used as an indicator of changes in land and/or ocean environments. Land development and rapid population and economic growth can cause subsidence due to excess groundwater extraction, reduction of river sediment supply by dams, and floodplain engineering. Global eustatic and local relative sea-level changes can also significantly affect the coastline of the lowland area. The main purpose of this study is to investigate the causes of shoreline change in the Chao Phraya (CPY) River delta in Thailand, which is a coastal region dominated by intertidal mudflats. This study focuses on river sediment supply, relative sea level change, and mangrove deforestation. Long-term historical data coupled with field observation were used to determine how these factors are related to shoreline retreat of the delta coastline. Shoreline change evaluation for the Upper Gulf of Thailand, including the Chao Phraya estuary between 1954 and 2013, are based on a series of aerial photographs and satellite imagery. This data set represents historical shoreline positions with time intervals ranging from 2 years to 24 years. The shoreline data were converted into vectorized ArcGIS shapefiles and analyzed using the USGS Digital Shoreline Analysis System ArcGIS extension. River survey data collected during the period 2011-2013 were used for studying the characteristics of river flow and sediment transport in the river system. During the period 2011-2013, the flow and sediment characteristics of rivers were measured 9 times at 8 stations in the Ping, Wang, Yom, Nan, and Chao Phraya rivers. The data cover wet season and dry season flow conditions, including the extreme flood event during 2011. Additionally, sediment deposition rates at the Chao Phraya River mouth were estimated from two sediment cores taken from the Chao Phraya River mouth using 210Pb radiometric dating. The results of this study indicate that relative sea-level rise due to the extremely high rate of land subsidence is the major cause of rapid shoreline change in the CPY Delta, and is responsible for 56 and 63 percent of shoreline retreat in the western and eastern portions of the Chao Phraya Delta, respectively. Unlike other major deltas in the southeast and east Asia, the severe shoreline recession during the period 1954-2013 is not strongly related to sediment supply reduction associated with large dam impoundments. Conversely, sediment deposition rates at the CPY Delta tended to increase after 1994 (30 and 22 years after construction of the Bhumibol and Sirikit Dams, respectively). However, the observed average rate of sediment deposition (8-10 mm/year) is less than the average rate of relative sea-level rise (17 mm/year), and the sediment supply from the CPY is not sufficient to balance land loss due to the rise of sea-level during the past six decades. For land-use changes, most of the vegetation areas, especially mangrove forest bounding along the edge of the shoreline, have been converted into aquacultural farmland by 1994. Results from mangrove area analysis over the period 1954-2013 reveal that the reduction of shoreline retreat rates in the eastern CPY was not directly associated with an increase in mangrove areas undergoing reforestation, and mangrove reforestation could not be cited as a shoreline builder or effective measure for coastal protection for coastlines that are rapidly retreating due to land subsidence. However, conversion of mangrove areas into aquaculture farmland can magnify shoreline retreat caused by relative sea-level rise. Results of this study may provide a useful analog for other coastal regimes of the Earth that may experience the effect of the predicted 1-2 meter rise over the next century associated with global warming. / A Dissertation submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2016. / June 7, 2016. / muddy coast, relative sea-level change, Sedimentation, sediment supply, sediment transport, shoreline change / Includes bibliographical references. / Stephen A. Kish, Professor Co-Directing Dissertation; Joseph F. Donoghue, Professor Co-Directing Dissertation; James B. Elsner, University Representative; William C. Burnett, Committee Member; William C. Parker, Committee Member.

The Silurian was a period characterized by rapidly fluctuating climate, multiple biotic turnover events, and eustatic sea-level variability. The Homerian Mulde biotic event (late Wenlock), ~428Ma, lies between the Sheinwoodian (early Wenlock) Ireviken and late Ludlow (mid- Ludfordian) Lau extinction events. It is characterized by a near complete extinction (95% loss) in graptolites, a severe drop (~80%) in diversity in conodonts, and a 50% loss in acritarchs (organic-walled phytoplankton groups), collectively known as the Wenlock ‘Big Crisis’. Previous studies have aligned the various Big Crisis extinctions to a double peaked carbon isotope excursion (CIE), known as the Mulde CIE, and inferred this to be a major change in the global carbon cycle. However, causal mechanisms that link the Mulde CIE to the ‘Big Crisis’ remain poorly constrained. In this thesis, two carbonate-bearing sequences connected to separate paleobasins, the shallow shelf carbonate sequence at McCrory Lane, TN and upper slope mixed siliclastic-marl sequence at Coal Canyon, Simpson Park Range, NV have been analyzed for multiproxy investigations. I present new δ13C, δ34S, I/(Ca+Mg), pyrite framboid, and carbonate microfacies data from these two successions spanning the Mulde CIE and Big Crisis interval. I document for the first time a positive ~10‰ shift in δ34SCAS during the Big Crisis extinction interval and first peak of the Mulde CIE. This suggests an expansion of reducing conditions globally; triggering enhanced organic matter and pyrite burial during a eustatic sea-level rise. At McCrory Lane, TN, local pyrite sulfur, I/(Ca+Mg), and microfacies fauna analysis support enhanced pyrite burial, and indicate the temporary contraction of reducing conditions during the Big Crisis survival and recovery intervals and protracted eustatic high stand. During the recovery interval of the Big Crisis the second Mulde CIE peak occurs and new δ34SCAS data suggest a second smaller expansion of reducing conditions in the late Wenlock oceans occurred. Interestingly, there is no documented no biotic turnover that occurs in concert with the second Mulde CIE peak suggesting a smaller and limited nature of this second expansion of marine reducing conditions. Statistical thin section analyses of fauna grain composition and niche replacement and near ubiquitous presence of pyrite framboids further support the notion that global oxygen content and bioavailability is still playing a major role in the evolution of biosphere and oceanic redox conditions through the mid-Paleozoic. / A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science. / 2019 / August 28, 2019. / Extinction, Late Wenlock, Mulde, Paleozoic, Redox, Silurian / Includes bibliographical references. / Seth A. Young, Professor Directing Thesis; Jeremy D. Owens, Committee Member; Yang Wang, Committee Member.

The goal of this thesis is to develop a dynamic stability and control module that can be used in the concept exploration phase of design. The purpose of the module is to determine the hydrodynamic coefficients/derivatives and stability characteristics of a given design. Two tools, GEORGE and CEBAXI and LA_57, were used to model a submarine, calculate its hydrodynamic coefficients, and determine its stability in the horizontal and vertical plane. GEORGE was developed and used heavily at Naval Coastal Systems Laboratory (NSWCPC) in Panama City, FL and the CEBAXI and LA_57 program was developed partially at University of California State at Long Beach and at the Carderock Division of the Naval Surface Warfare Center (NSWCCD) and is in use at NSWCCD in Bethesda, MD. Both programs require the hull offsets and geometry of the control surfaces as input. The hull offsets were determined by assuming an idealistic teardrop shape and a method for sizing control surfaces was developed by using previous designs to determine sizing trends. ModelCenter software was used to integrate the methods to determine the offsets and control surface geometry with the stability programs. A design of experiments was performed to determine the influence of various input variables on the stability indices and response surface models were created. The response surfaces were implemented into a Total Ship Systems Engineering optimization process used in the senior ship design course at Virginia Tech. / Master of Science

Thesis (M.S. in Modeling, Virtual Environments and Simulation (MOVES))--Naval Postgraduate School, March 2004. / Thesis advisor(s): Christian Darken, Curtis Blais. Includes bibliographical references (p. 103-104). Also available online.