scholarly journals Determination of acoustic waveguide invariant using ships as sources of opportunity in a shallow water marine environment

2017 ◽  
Vol 141 (2) ◽  
pp. EL102-EL107 ◽  
Author(s):  
Christopher M. A. Verlinden ◽  
J. Sarkar ◽  
B. D. Cornuelle ◽  
W. A. Kuperman
Keyword(s):  
Shallow Water ◽  
Marine Environment ◽  
Acoustic Waveguide ◽  
Waveguide Invariant

Determination of acoustic waveguide invariant using ships as sources of opportunity in a shallow water marine environment

2016 ◽  
Vol 140 (4) ◽  
pp. 3364-3364
Author(s):  
Christopher M. Verlinden ◽  
Jit Sarkar ◽  
Bruce Cornuelle ◽  
William A. Kuperman
Keyword(s):  
Shallow Water ◽  
Marine Environment ◽  
Acoustic Waveguide ◽  
Waveguide Invariant

scholarly journals Evaluation of the sedimentary environment of the block 102 of Song Hong basin by petrophysics

2015 ◽  
Vol 18 (4) ◽  
pp. 84-101
Author(s):  
Thanh Thi Ngoc Nguyen ◽  
Luan Thi Bui
Keyword(s):  
Spatial Distribution ◽  
Shallow Water ◽  
Marine Environment ◽  
Coastal Plain ◽  
Tidal Flat ◽  
Middle Miocene ◽  
Sedimentary Environment ◽  
Late Oligocene ◽  
Delta Plain

Interpretation of wireline logging data supported to recover the sedimentary environment of block 102 of Song Hong basin. It inchided in determination of the spatial distribution of source, reservoir and cap rocks and an indispensable part in oil exploration of this area. Resulted wireline logging data showed some sedimentary environment units as the following The late Oligocene was delta environment. It was identified as forming delta plain, swamp to lacustrine. The middle Miocene had changed to shallow water marine environment, which formed the shoreface, tidal flat, lagoon and channel. The lower Miocene was aluvial environment that changed into fluvial and coastal plain.

Spatial assemblage structure of shallow-water reef fish in Southwest Australia

2020 ◽  
Vol 649 ◽  
pp. 125-140
Author(s):  
DS Goldsworthy ◽  
BJ Saunders ◽  
JRC Parker ◽  
ES Harvey
Keyword(s):  
Shallow Water ◽  
Reef Fish ◽  
Marine Environment ◽  
Fish Assemblages ◽  
Canopy Cover ◽  
Reef Fishes ◽  
Reef Fish Assemblage ◽  
Reef Type ◽  
Present Distribution ◽  
Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

Determination of the added masses and damping coefficients during coupled motions of two ships in shallow water parallel to the vertical wall

2021 ◽  
pp. 16-25
Author(s):  
В.Ю. Семенова ◽  
К.И. Баканов
Keyword(s):  
Shallow Water ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Hydrodynamic Coefficients ◽  
Damping Coefficients ◽  
Added Masses ◽  
Joint Motions ◽  
National Practice ◽  
Simultaneous Influence

В статье рассматривается определение коэффициентов демпфирования и присоединенных масс, возникающих при совместной качке двух судов в условиях мелководья параллельно вертикальной стенке на основании решения трехмерной потенциальной задачи. Определение гидродинамических коэффициентов осуществляется на основании методов интегральных уравнений и зеркальных отображений. Представленное решение в отечественной практике является новым. В статье приводятся результаты расчетов коэффициентов присоединенных масс и демпфирования, возникающих при качке двух одинаковых судов, расположенных лагом к волнению и параллельно вертикальной стенке в зависимости от изменения расстояний как между судами, так и между судами и вертикальной стенкой. Проводится исследование влияния различных фарватеров на величины гидродинамических коэффициентов, а именно: мелководного фарватера, мелководного фарватера с вертикальной стенкой, мелководного фарватера со вторым параллельно качающимся судном и мелководного фарватера с вертикальной стенкой и вторым судном. Таким образом, в работе учитывается одновременное влияния мелководья, вертикальной стенки и второго судна. Показано увеличение значений коэффициентов присоединенных масс и демпфирования при уменьшении расстояний между судами и между судами и вертикальной стенкой. Также показано значительное совместное влияние вертикальной стенки и второго судна на коэффициенты присоединенных масс и демпфирования по сравнению с другими видами стесненных фарватеров. The article discusses the determination of damping coefficients and added masses arising from the joint motions of two ships in shallow water conditions parallel to the vertical wall based on the solution of a three-dimensional potential problem. Determination of hydrodynamic coefficients is carried out on the basis of the methods of integral equations and mirror images. The solution presented in the national practice is new The article presents the results of calculating the coefficients of added masses and damping arising from the motions of two identical ships located lagged to the sea and parallel to the vertical wall, depending on the change in the distances between the ships and between the ships and the vertical wall. A study is being made of the influence of various waterways on the values ​​of hydrodynamic coefficients, namely: a shallow waterway, a shallow waterway with a vertical wall, a shallow waterway with a second parallel oscillating ship and a shallow waterway with a vertical wall and a second ship. Thus, the work takes into account the simultaneous influence of shallow water, vertical wall and the second ship. An increase in the values of the coefficients of added masses and damping with a decrease in the distances between ships and between ships and the vertical wall is shown. It also shows a significant combined effect of the vertical wall and the second ship on the added mass and damping coefficients in comparison with other types of constrained waterways.

scholarly journals Corrosion Resistance of Fiber-reinforced Geopolymer Structural Concrete in a Simulated Marine Environment

2021 ◽  
Author(s):  
Khaled Sobhan ◽  
Francisco Martinez ◽  
D.V. Reddy
Keyword(s):  
Corrosion Resistance ◽  
Marine Environment ◽  
Electrochemical Method ◽  
Ordinary Portland Cement ◽  
Load Capacity ◽  
Fiber Reinforced ◽  
Structural Concrete ◽  
Accelerated Corrosion ◽  
Damaged Beams

The corrosion resistance of fly ash-based geopolymer structural concrete (GPC), with or without fibers, was investigated in a simulated marine environment, and compared with that of ordinary Portland cement structural concrete. The corrosion behavior is studied through an electrochemical method for inducing accelerated corrosion. The fiber-reinforced specimens contained polyolefin fibers in the amounts of 0.1%, 0.3%, and 0.5% by volume. Several artificial corrosion conduits were introduced into the specimens reaching up to the rebars. This process enhanced the rate of laboratory corrosion in GPC. The corrosion-damaged beams were then analyzed through a method of crack scoring, and determination of steel mass loss and residual flexural load capacity. The fiber-reinforced corroded GPC beams showed a 24% reduction in crack scores, and a 109% increase in residual flexural load capacity, compared to unreinforced corroded GPC beams. This shows promise of fiber-reinforced GPC as a sustainable structural material in the marine environment.

Metal pollution assessment of the marine environment by determination of metal-binding proteins in Mytilus sp.

1987 ◽  
Vol 22 (2-4) ◽  
pp. 235-248 ◽  
Author(s):  
J Pavičič ◽  
M Škreblin ◽  
B Raspor ◽  
M Branica ◽  
M Tušek-Ẑnidarič ◽  
...  
Keyword(s):  
Marine Environment ◽  
Metal Pollution ◽  
Metal Binding ◽  
Binding Proteins ◽  
Pollution Assessment

scholarly journals Measured depth-dependence of waveguide invariant in shallow water with a summer profile

2016 ◽  
Vol 139 (6) ◽  
pp. EL184-EL189 ◽  
Author(s):  
Altan Turgut ◽  
Laurie T. Fialkowski ◽  
Jeffrey A. Schindall
Keyword(s):  
Shallow Water ◽  
Depth Dependence ◽  
Waveguide Invariant
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