Non-linear Corrosion Model for Immersed Steel Plates Accounting for Environmental Factors

2005 ◽  
Author(s):  
Carlos Guedes Soares ◽  
Yordan Garbatov ◽  
Ahmed Zayed ◽  
Ge Wang
Keyword(s):  
Environmental Factors ◽  
Dissolved Oxygen ◽  
Linear Time ◽  
Salt Water ◽  
Steel Plates ◽  
Time Dependent ◽  
The Pacific ◽  
Non Linear ◽  
The Pacific Ocean ◽  
Marine Environmental

The effects of different marine environmental factors on the corrosion behavior of steel plates totally immersed in salt water are studied. A new corrosion wastage model is proposed, based on a non-linear time-dependent function. This model accounts for the effects of various environmental factors, including salinity, temperature, dissolved oxygen, pH and flow velocity. A numerical example is illustrated for ships trading in different routes in the Pacific Ocean.

scholarly journals Response of export production and dissolved oxygen concentrations in oxygen minimum zones to <i>p</i>CO<sub>2</sub> and temperature stabilization scenarios in the biogeochemical model HAMOCC 2.0

2017 ◽  
Vol 14 (4) ◽  
pp. 781-797 ◽  
Author(s):  
Teresa Beaty ◽  
Christoph Heinze ◽  
Taylor Hughlett ◽  
Arne M. E. Winguth
Keyword(s):  
Pacific Ocean ◽  
Organic Carbon ◽  
Dissolved Oxygen ◽  
Radiative Forcing ◽  
The Pacific ◽  
Poc Flux ◽  
Poc Export ◽  
The Pacific Ocean ◽  
Do Concentration ◽  
Oxygen Minimum

Abstract. Dissolved oxygen (DO) concentration in the ocean is an important component of marine biogeochemical cycles and will be greatly altered as climate change persists. In this study a global oceanic carbon cycle model (HAMOCC 2.0) is used to address how mechanisms of oxygen minimum zone (OMZ) expansion respond to changes in CO2 radiative forcing. Atmospheric pCO2 is increased at a rate of 1 % annually and the model is stabilized at 2 ×, 4 ×, 6  ×, and 8 × preindustrial pCO2 levels. With an increase in CO2 radiative forcing, the OMZ in the Pacific Ocean is controlled largely by changes in particulate organic carbon (POC) export, resulting in increased remineralization and thus expanding the OMZs within the tropical Pacific Ocean. A potential decline in primary producers in the future as a result of environmental stress due to ocean warming and acidification could lead to a substantial reduction in POC export production, vertical POC flux, and thus increased DO concentration particularly in the Pacific Ocean at a depth of 600–800 m. In contrast, the vertical expansion of the OMZs within the Atlantic is linked to increases POC flux as well as changes in oxygen solubility with increasing seawater temperature. Changes in total organic carbon and increase sea surface temperature (SST) also lead to the formation of a new OMZ in the western subtropical Pacific Ocean. The development of the new OMZ results in dissolved oxygen concentration of  ≤  50 µmol kg−1 throughout the equatorial Pacific Ocean at 4 times preindustrial pCO2. Total ocean volume with dissolved oxygen concentrations of  ≤  50 µmol kg−1 increases by 2.4, 5.0, and 10.5 % for the 2 ×, 4 ×, and 8 × CO2 simulations, respectively.

New features of non-linear time-dependent two-level atoms

2019 ◽  
Vol 105 ◽  
pp. 171-181
Author(s):  
Mehdi Akremi ◽  
S.T. Korashy ◽  
T.M. El-Shahat ◽  
R. Nekhili ◽  
Inamuddin ◽  
...  
Keyword(s):  
Linear Time ◽  
Time Dependent ◽  
Non Linear

scholarly journals DYNAMICS OF T=0 BCS CONDENSATES

1995 ◽  
Vol 09 (11) ◽  
pp. 1359-1373 ◽  
Author(s):  
MICHAEL STONE
Keyword(s):  
Fermi Surface ◽  
Order Parameter ◽  
Schrodinger Equation ◽  
Linear Time ◽  
Time Dependent ◽  
Pitaevskii Equation ◽  
Long Wavelength ◽  
Non Linear ◽  
Bose Superfluid ◽  
Galilean Invariant

Fermi-surface bosonization is used to show that the long-wavelength, T=0, dynamics of a BCS superfluid or superconductor is described by a galilean invariant non-linear time-dependent Schrödinger equation. This equation is of same form as the Gross-Pitaevskii equation for a Bose superfluid, but the “wavefunction” is not the superfluid order parameter.

scholarly journals Insights Into the Environmental Impact on Genetic Structure and Larval Dispersal of Crown-of-Thorns Starfish in the South China Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Biao Chen ◽  
Kefu Yu ◽  
Qiucui Yao ◽  
Zhiheng Liao ◽  
Zhenjun Qin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Environmental Factors ◽  
South China Sea ◽  
Larval Dispersal ◽  
Population Expansion ◽  
Convergence Region ◽  
Genetic Characteristics ◽  
The Pacific ◽  
The Pacific Ocean

The coral-eating crown-of-thorns starfish (COTS; Acanthaster spp.) play a major role in coral reef degradation in the Indo-Pacific region. However, the impacts of environmental factors on the phylogenetic and genetic characteristics of COTS in the northern Indo-Pacific convergence region remains unclear. We used mitochondrial DNA (mtDNA) and microsatellite markers to analyze the phylogenetic relationship, demographic history, genetic diversity and genetic structure of COTS in the South China Sea (SCS) and explored the impact of environmental factors on historical population expansion, genetic differentiation and larval dispersal. There was a clear signature of a population expansion in the SCS using the mtDNA marker. According to microsatellite loci analysis, COTS have high genetic diversity in the SCS. STRUCTURE analysis indicated that COTS in the Pacific Ocean can be divided into four subgroups: the SCS, Western Pacific, Pacific equatorial current affected zone, and Pacific insular atolls populations in the Pacific Ocean. Fst-statistical analysis revealed positive correlations between the Fst values and geographic isolation for all sampling sites. Additionally, there were no clear associations between the Fst values and chlorophyll a concentrations among coral reefs in the SCS; however, there were significant positive associations between the Fst values and particulate organic carbon (POC) concentrations within small geographic distances. These results suggest that COTS underwent historical population expansion after the Last Glacial Maximum, possibly followed by coral population expansion. The genetic structure of COTS populations may have been shaped by distinct nutrient concentrations, particularly those of POC, over small geographic distances. Moreover, ocean currents provide a potential dispersal mechanism for COTS larvae in the SCS. This study demonstrates that environmental and oceanographic factors play important roles in shaping the genetic characteristics and larval dispersal of COTS populations in the northern Indo-Pacific convergence region.

2D Modelling of rockslide displacements by non-linear time dependent relationships

2018 ◽  
pp. 765-770
Author(s):  
M. De Caro ◽  
G.B. Crosta ◽  
R. Castellanza ◽  
F. Agliardi ◽  
G. Volpi ◽  
...  
Keyword(s):  
Linear Time ◽  
Time Dependent ◽  
2D Modelling ◽  
Non Linear

Analysis of Numerical Oscillation Problems in a Non Linear Time Dependent Mild Slope Model and First Developments for the Implementation of Wave Breaking

2008 ◽  
Author(s):  
Ana Catarina Zo´zimo ◽  
Conceic¸a˜o Fortes
Keyword(s):  
Energy Dissipation ◽  
Wave Breaking ◽  
Linear Time ◽  
Momentum Equation ◽  
Time Dependent ◽  
Theoretical Formulation ◽  
Dissipative Term ◽  
Mild Slope Equation ◽  
Non Linear ◽  
Work Done

In this paper, a description of the numerical model NMLSE is presented. This model solves the time dependent non linear mild slope equation, without including energy dissipation due to wave breaking [1]. Some modifications are made in the boundary conditions of the original version of the model in order to overcome the numerical oscillation problems detected in the work done by [2]. To evaluate the effectiveness of the new versions of the model, they are applied to test cases of the bibliography and to a bar-trough profile beach for which there are data from physical model tests. The basic theoretical formulation of a new momentum equation that includes energy dissipation due to wave breaking is also presented. The energy dissipation due to wave breaking is included through the addition of a dissipative term based in the eddy viscosity concept.

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