Andres Peratta - Profile on Academia.edu (original) (raw)

Papers by Andres Peratta

Research paper thumbnail of Using Predicted Corrosion Damage to Determine Stress Concentration, Fracture and Crack Growth

Corrosion, 2016

Structures subject to corrosion damage are likely to develop stress concentrations on the damaged... more Structures subject to corrosion damage are likely to develop stress concentrations on the damaged surfaces, and these stress concentrations may lead to initiation of cracks and possible crack growth. If dissimilar materials are present, it is likely that areas will exist where anodic current flows from a structural surface into the electrolyte, so causing mass loss from the surface. The magnitude of the anodic current density is directly proportional to the rate of mass loss from the surface, and can be used to determine surface shape change. Such shape change generally results in indentations, which from a stress analysis point of view act as stress-raisers. Simulation to determine magnitude of the stress concentration can identify most likely sites for crack initiation. The possibility of crack growth, and the time taken for the growth, can be determined using fracture and crack growth simulation. This paper explores the combined use of galvanic simulation and fracture/crack growt...

Research paper thumbnail of Human Exposure to Low Frequency Fields

Human Exposure to Low Frequency Fields

The paper deals with the assessment of human exposure to extremely low frequency electric fields ... more The paper deals with the assessment of human exposure to extremely low frequency electric fields using sophisticated numerical tools.

Research paper thumbnail of Galvanic Corrosion Modelling for Aircraft Environments

Galvanic Corrosion Modelling for Aircraft Environments

The aim of this work is to develop and validate a computational model for simulating galvanic cor... more The aim of this work is to develop and validate a computational model for simulating galvanic corrosion in macroscopic samples for further application in typical case scenarios appearing in an aircraft environment. The case study involved in this paper consists of a co-planar bimetallic pair composed of Aluminium AA 2024 and carbon fibre reinforced polymer (CFRP) immersed in saline solution. The computational approach, based on the Boundary Element Method (BEM), aims at solving current density and electric potential in the electrolyte and active electrode surfaces. The obtained BEM based numerical simulation tool is validated with experimental measurements in a controlled environment. The modelling approach as well as the experimental methodology for characterising the material properties used as input in the simulation and for validating the results is described throughout this paper. The experimental measurements of potential at different points in the electrolyte and total curren...

Research paper thumbnail of A Computational Modeling Framework for Predicting Accumulated Galvanic Corrosion Damage Using a Service Life Model

The application of corrosion modeling to aircraft structural components can provide significant v... more The application of corrosion modeling to aircraft structural components can provide significant value with regard to reducing fleet maintenance and the life-cycle corrosion cost of an aircraft. A computational modeling framework (corrosion service life model) is being developed to support the prediction of corrosion damage in aircraft structures. This framework includes easy-to-use software tools to predict corrosion rates based on implementation of analytical curve crossing techniques, and more sophisticated approaches, based on the creation of computational models that represent the actual component geometry. The analytical curve crossing technique has been developed to support new requirements being considered in the revised MIL-STD-889. A key aspect of this revision is that galvanic current, created when joining materials, is an important consideration for galvanic compatibility decision making. The more involved computational modeling approach expands on this and provides capab...

Research paper thumbnail of A 3D BEM Modelling Of Human Exposure ToExtremely Low Frequency (ELF) Electric Fields

The boundary element analysis of the human body exposed to extremely low frequency (ELF) electric... more The boundary element analysis of the human body exposed to extremely low frequency (ELF) electric fields is presented in this work. The human being is represented by a multidomain inhomogeneous body of revolution. The formulation of the problem is based on the quasi-static approximation and the related Laplace equation form of the continuity equation. This Laplace equation has been solved by the boundary element method (BEM). Solving the resulting Laplace equation for the electric scalar potential, the induced current density inside the human body is obtained. This quantity is the fundamental parameter in further analysis of possible biological effects of ELF exposures. An illustrated computational example of the human body exposed to the electric field generated by an overhead power line is also presented.

Research paper thumbnail of Environmental Electromagnetic Compatibility

Journal of Communications Software and Systems, 2007

Guest Editorial Environmental Electromagnetic Compatibility n the last decades, there have been a... more Guest Editorial Environmental Electromagnetic Compatibility n the last decades, there have been a number of significant advances in many areas of Environmental Electromagnetic Compatibility (EEMC). Valuable contributions of the electromagnetic field analysis related to the antennas, lines and cables, bioelectromagnetics, broadband EMI, lightning, etc. have been presented in many conferences and also reported in many acclaimed international journals. These studies, which have been carried out by numerical simulation and experimental techniques, provide the scientific knowledge for the electromagnetic phenomena in general and also give scientific background and improvement in electromagnetic and thermal dosimetry, design and protection of electrical and electronic equipment. Therefore, the Guests Editors enthusiastically accepted the proposal of prof. N. Rozic, Editorial Chair of Journal of Communications, Software an Systems (JCOMSS), to edit a Special Issue on Environmental Electromagnetic Compatibility by collecting some important recent contributions achieved by prominent researchers in this area. Initial idea was to edit an issue on Mobile and Wireless Communications, but we finally extend aims and scopes of this particular issue to many other areas of EMC and decide to produce a special issue on Environmental Electromagnetic Compatibility (EEMC). This Special Issue on Environmental Electromagnetic Compatibility contains 8 papers selected through the international review process and grouped into the three topics:

Research paper thumbnail of Macroscale Galvanic Corrosion Modelling of an Aluminium Alloy

Macroscale Galvanic Corrosion Modelling of an Aluminium Alloy

Aluminium Alloy Corrosion of Aircraft Structures, 2012

Research paper thumbnail of Hierarchical matrices and adaptive cross approximation applied to the boundary element method with multi-domain governed by iterative coupling

Mesh Reduction Methods, 2009

The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied t... more The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied to the matrices coming from the Boundary Element Method (BEM) with multi-domain. The algorithm uses a hierarchical matrix (H-matrix) storage approach splitting the coefficient matrices representing the interactions inside the sub-domains into many blocks where rank of the off-diagonal blocks is reduced with the help of ACA approximation. The sub-domains are then coupled through the iterative process. These optimisations of the coefficient matrices in conjunction with highly effective algorithms for manipulation with H-matrices allow one to perform the operation of matrix-vector multiplication with almost linear complexity O(NlogN). The approach allows one to solve the linear systems of equations for BEM with multi-domain having nearly 100.000 DOFs using the usual PC. This paper formulates the approach and demonstrates its numerical properties by means of a theoretical example involving a cube with 27 sub-domains.

Research paper thumbnail of Adaptive cross approximation based solver for boundary element method with single domain in 3D

Boundary Elements and Other Mesh Reduction Methods XXX, 2008

The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied t... more The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied to BEM-derived matrices. The ACA method is purely algebraic and does not require information on the kernel. In this way, it offers an interesting alternative to the well established Fast Multipole Method. The algorithm uses a hierarchical approach for the matrix storage and manipulation. This paper describes the assembly approach for the usual H and G matrices coming from BEM equations into a hierarchical coefficient matrix A H. The efficiency of the developed scheme is tested for a potential problem involving a 3D unitary cube, and then the method is applied to an electrostatic problem involving an anatomic model of the human body. This 3D example consisting of 80 000 degrees of freedom could easily be solved in a low specification PC.

Research paper thumbnail of Boundary element modeling of complex grounding systems: Study on current distribution

WIT Transactions on Modelling and Simulation, 2010

The assessment of current distribution induced along complex grounding systems has been undertake... more The assessment of current distribution induced along complex grounding systems has been undertaken using the corresponding antenna model and the set of Pocklington integro-differential equations for curved wires. The set of Pocklington equations is numerically handled via the Galerkin-Bubnov scheme of the Indirect Boundary Element Method (GB-IBEM) featuring the isoparametric elements. Some illustrative numerical results for the current distribution are presented in the paper.

Research paper thumbnail of Recovering current density from data on electric potential

Simulation of Electrochemical Processes III, 2009

In this paper, an inverse problem for galvanic corrosion in two-dimensional Laplace's equation wa... more In this paper, an inverse problem for galvanic corrosion in two-dimensional Laplace's equation was studied. The considered problem deals with experimental measurements on electric potential, where due to lack of data, numerical integration is impossible. The problem is reduced to the determination of unknown complex coefficients of approximating functions, which are related to the known potential and unknown current density. By employing continuity of those functions along subdomain interfaces and using condition equations for known data leads to over-determined system of linear algebraic equations which are subjected to experimental errors. Reconstruction of current density is unique. The reconstruction contains one free additive parameter which does not affect current density. The method is useful in situations where limited data on electric potential are provided.

Research paper thumbnail of 3D FEM temperature distribution analysis of the human eye exposed to laser radiation

Advanced Computational Methods and Experiments in Heat Transfer XI, 2010

This paper is an extension of a previously published work on thermal modelling of the human eye e... more This paper is an extension of a previously published work on thermal modelling of the human eye exposed to radiation by various lasers. The 2D model is now extended to 3D in order to give a more realistic representation of the human eye model when irradiated by laser. The model is based on space-time dependent Pennes' bio-heat transfer equation solved by the finite elements method featuring Galerking-Bubnov procedure. The results for the temperature field inside the eye could prove to be useful in minimising the possible damage to intraocular tissues during the ophthalmological procedures and also later in analysis of laser-tissue interaction mechanisms. Also, analysis of various parameters on the calculated temperature distribution is carried out.

Research paper thumbnail of Safety Assessment For Disposal Of HazardousWaste In Abandoned Underground Mines

Disposal of hazardous chemical waste in abandoned underground mines is believed to be an achievab... more Disposal of hazardous chemical waste in abandoned underground mines is believed to be an achievable, low risk and relatively cheap way of disposal of hazardous waste. The objective of the FP5 EC project Low Risk Disposal Technology (LowRiskDT) was to investigate the prerequisites for using this alternative, to outline suitable design and construction technology and to make a performance assessment with special respect to environmental safety and cost. Calculations were made of the isolating capacity of reference repositories in terms of the concentration of hazardous ion species appearing in the far-field groundwater. Relevant flow and dispersion models were applied to the reference cases representing different rock structures and flow path patterns. The release and migration of dissolved hazardous chemical species with special respect to groundwater protection are determined for the worst-case scenario. A numerical tool has been developed that can be used for analysis of transport ...

Research paper thumbnail of Using a Computational Galvanic Model in a Fracture Mechanics Framework to Improve Material Degradation Prediction

Using a Computational Galvanic Model in a Fracture Mechanics Framework to Improve Material Degradation Prediction

Corrosion, 2020

Research paper thumbnail of Temperature rise in the human body exposed to radiation from base station antennas

Thermal analysis of human expoure to base station antennas radiation is presented in this work. T... more Thermal analysis of human expoure to base station antennas radiation is presented in this work. The formulation is based on a simplified cylindrical representation of the human body. Knowing the internal electric field and related total absorbed power in the human body, a resulting thermal response of the body due to the exposure to high frequency (HF) radiation can be determined. The temperature rise in the body exposed to base stations antenna radiation is determined by solving the bio-heat transfer equation via both the dual reciprocity boundary element method (DR-BEM) and finite element method (FEM). The temperature rise in the body is found to be rather negligible.

Research paper thumbnail of Electromagnetic Modeling of the Human Body Exposed to Extremely Low Frequency (ELF) Electromagnetic Field

Electromagnetic Modeling of the Human Body Exposed to Extremely Low Frequency (ELF) Electromagnetic Field

Analytical modeling of the human body exposed to extremely low frequency electromagnetic radiatio... more Analytical modeling of the human body exposed to extremely low frequency electromagnetic radiation is presented in this article, which contribution is based on the comparison between different approximations. Cylindrical approximation is based on a theory of receiving antenna and presentation of the human body as a parasitic antenna exposed to an incident electric field. Through cylindrical approximation, the induced current inside the human body is calculated. This current is used for evaluating adverse health effects that electric field has on the human body. Different cases of exposure are considered, taking into account insulation between human body and the earth. Ellipsoidal approximation is used as a comparison to cylindrical. Finally, the comparison with the numerical model is made. Numerical model is based on Boundary Element Method (BEM) and the results obtained are shown to be in very good agreement.

Research paper thumbnail of Modelling Impressed Current Cathodic Protection of Storage Tanks

Modelling Impressed Current Cathodic Protection of Storage Tanks

This work is focused on the simulation of the type of ICCP system in which a grid of anode ribbon... more This work is focused on the simulation of the type of ICCP system in which a grid of anode ribbons and distribution bars, buried below the base of a tank, is supplied with power from a transformer rectifier unit. Current flows from the anode ribbons through the wet sand in which they are embedded, to the base of the tank, and then back to the TRU. The ICCP system is represented mathematically as a circuit including the TRU, distribution cables connecting it to a number of distribution bars, an array of anode ribbons welded to the distribution bars, and the return cable connecting the tank base to the return of the TRU. The electrical circuit equations are solved to determine current flow and electrical potential throughout the grid of anode ribbons and distribution bars. Current flow from the surfaces of the anode ribbons into the surrounding electrolyte, and from the electrolyte into the surface of the tank base, is described using polarization curves, which encapsulate the non-lin...

Research paper thumbnail of Application Of Computational Modeling To Predict The Effectiveness Of Cp On A Pccp Transmission Pipeline

Application Of Computational Modeling To Predict The Effectiveness Of Cp On A Pccp Transmission Pipeline

Prestressed Concrete Cylinder Pipe (PCCP) is a rigid pipe designed to take optimum advantage of t... more Prestressed Concrete Cylinder Pipe (PCCP) is a rigid pipe designed to take optimum advantage of the tensile strength of steel and of the compressive strength and corrosion inhibiting properties of concrete and is frequently used for water transmission. PCCP consists of a steel cylinder embedded in a concrete core, which is helically wrapped with high-strength, hard-drawn wire after curing. The wire is embedded in thick cement slurry and coated with a dense cement mortar. While the cement mortar and additional coatings usually protect the prestressing wires from corrosion, in certain circumstances chlorides can diffuse into the mortar and reach the wires. Therefore PCCP transmission pipelines can also be protected by CP systems to mitigate the risk of corrosion damage when chlorides are high in the soil. This paper describes a computer modeling study which was designed to determine the protection provided by a CP system, to evaluate different design options, and to optimize the desig...

Research paper thumbnail of Case Study of an ICCP Design and Installation for Well Casings Using Boundary Elements Software, Evaluating Different Deep Anode Architectures and Interference to Nearby Casings

Case Study of an ICCP Design and Installation for Well Casings Using Boundary Elements Software, Evaluating Different Deep Anode Architectures and Interference to Nearby Casings

Corrosion, 2016

Research paper thumbnail of Rock structure control of groundwater flow and stability – disposal of hazardous waste in abandoned mines

Rock structure control of groundwater flow and stability – disposal of hazardous waste in abandoned mines

Multibarrier isolation of hazardous waste is proposed by organizations and companies responsible ... more Multibarrier isolation of hazardous waste is proposed by organizations and companies responsible for underground disposal of such waste. The host rock of repositories is of majorimportance and cons ...

Research paper thumbnail of Using Predicted Corrosion Damage to Determine Stress Concentration, Fracture and Crack Growth

Corrosion, 2016

Structures subject to corrosion damage are likely to develop stress concentrations on the damaged... more Structures subject to corrosion damage are likely to develop stress concentrations on the damaged surfaces, and these stress concentrations may lead to initiation of cracks and possible crack growth. If dissimilar materials are present, it is likely that areas will exist where anodic current flows from a structural surface into the electrolyte, so causing mass loss from the surface. The magnitude of the anodic current density is directly proportional to the rate of mass loss from the surface, and can be used to determine surface shape change. Such shape change generally results in indentations, which from a stress analysis point of view act as stress-raisers. Simulation to determine magnitude of the stress concentration can identify most likely sites for crack initiation. The possibility of crack growth, and the time taken for the growth, can be determined using fracture and crack growth simulation. This paper explores the combined use of galvanic simulation and fracture/crack growt...

Research paper thumbnail of Human Exposure to Low Frequency Fields

Human Exposure to Low Frequency Fields

The paper deals with the assessment of human exposure to extremely low frequency electric fields ... more The paper deals with the assessment of human exposure to extremely low frequency electric fields using sophisticated numerical tools.

Research paper thumbnail of Galvanic Corrosion Modelling for Aircraft Environments

Galvanic Corrosion Modelling for Aircraft Environments

The aim of this work is to develop and validate a computational model for simulating galvanic cor... more The aim of this work is to develop and validate a computational model for simulating galvanic corrosion in macroscopic samples for further application in typical case scenarios appearing in an aircraft environment. The case study involved in this paper consists of a co-planar bimetallic pair composed of Aluminium AA 2024 and carbon fibre reinforced polymer (CFRP) immersed in saline solution. The computational approach, based on the Boundary Element Method (BEM), aims at solving current density and electric potential in the electrolyte and active electrode surfaces. The obtained BEM based numerical simulation tool is validated with experimental measurements in a controlled environment. The modelling approach as well as the experimental methodology for characterising the material properties used as input in the simulation and for validating the results is described throughout this paper. The experimental measurements of potential at different points in the electrolyte and total curren...

Research paper thumbnail of A Computational Modeling Framework for Predicting Accumulated Galvanic Corrosion Damage Using a Service Life Model

The application of corrosion modeling to aircraft structural components can provide significant v... more The application of corrosion modeling to aircraft structural components can provide significant value with regard to reducing fleet maintenance and the life-cycle corrosion cost of an aircraft. A computational modeling framework (corrosion service life model) is being developed to support the prediction of corrosion damage in aircraft structures. This framework includes easy-to-use software tools to predict corrosion rates based on implementation of analytical curve crossing techniques, and more sophisticated approaches, based on the creation of computational models that represent the actual component geometry. The analytical curve crossing technique has been developed to support new requirements being considered in the revised MIL-STD-889. A key aspect of this revision is that galvanic current, created when joining materials, is an important consideration for galvanic compatibility decision making. The more involved computational modeling approach expands on this and provides capab...

Research paper thumbnail of A 3D BEM Modelling Of Human Exposure ToExtremely Low Frequency (ELF) Electric Fields

The boundary element analysis of the human body exposed to extremely low frequency (ELF) electric... more The boundary element analysis of the human body exposed to extremely low frequency (ELF) electric fields is presented in this work. The human being is represented by a multidomain inhomogeneous body of revolution. The formulation of the problem is based on the quasi-static approximation and the related Laplace equation form of the continuity equation. This Laplace equation has been solved by the boundary element method (BEM). Solving the resulting Laplace equation for the electric scalar potential, the induced current density inside the human body is obtained. This quantity is the fundamental parameter in further analysis of possible biological effects of ELF exposures. An illustrated computational example of the human body exposed to the electric field generated by an overhead power line is also presented.

Research paper thumbnail of Environmental Electromagnetic Compatibility

Journal of Communications Software and Systems, 2007

Guest Editorial Environmental Electromagnetic Compatibility n the last decades, there have been a... more Guest Editorial Environmental Electromagnetic Compatibility n the last decades, there have been a number of significant advances in many areas of Environmental Electromagnetic Compatibility (EEMC). Valuable contributions of the electromagnetic field analysis related to the antennas, lines and cables, bioelectromagnetics, broadband EMI, lightning, etc. have been presented in many conferences and also reported in many acclaimed international journals. These studies, which have been carried out by numerical simulation and experimental techniques, provide the scientific knowledge for the electromagnetic phenomena in general and also give scientific background and improvement in electromagnetic and thermal dosimetry, design and protection of electrical and electronic equipment. Therefore, the Guests Editors enthusiastically accepted the proposal of prof. N. Rozic, Editorial Chair of Journal of Communications, Software an Systems (JCOMSS), to edit a Special Issue on Environmental Electromagnetic Compatibility by collecting some important recent contributions achieved by prominent researchers in this area. Initial idea was to edit an issue on Mobile and Wireless Communications, but we finally extend aims and scopes of this particular issue to many other areas of EMC and decide to produce a special issue on Environmental Electromagnetic Compatibility (EEMC). This Special Issue on Environmental Electromagnetic Compatibility contains 8 papers selected through the international review process and grouped into the three topics:

Research paper thumbnail of Macroscale Galvanic Corrosion Modelling of an Aluminium Alloy

Macroscale Galvanic Corrosion Modelling of an Aluminium Alloy

Aluminium Alloy Corrosion of Aircraft Structures, 2012

Research paper thumbnail of Hierarchical matrices and adaptive cross approximation applied to the boundary element method with multi-domain governed by iterative coupling

Mesh Reduction Methods, 2009

The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied t... more The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied to the matrices coming from the Boundary Element Method (BEM) with multi-domain. The algorithm uses a hierarchical matrix (H-matrix) storage approach splitting the coefficient matrices representing the interactions inside the sub-domains into many blocks where rank of the off-diagonal blocks is reduced with the help of ACA approximation. The sub-domains are then coupled through the iterative process. These optimisations of the coefficient matrices in conjunction with highly effective algorithms for manipulation with H-matrices allow one to perform the operation of matrix-vector multiplication with almost linear complexity O(NlogN). The approach allows one to solve the linear systems of equations for BEM with multi-domain having nearly 100.000 DOFs using the usual PC. This paper formulates the approach and demonstrates its numerical properties by means of a theoretical example involving a cube with 27 sub-domains.

Research paper thumbnail of Adaptive cross approximation based solver for boundary element method with single domain in 3D

Boundary Elements and Other Mesh Reduction Methods XXX, 2008

The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied t... more The approach presented in this paper is based on the Adaptive Cross Approximation (ACA) applied to BEM-derived matrices. The ACA method is purely algebraic and does not require information on the kernel. In this way, it offers an interesting alternative to the well established Fast Multipole Method. The algorithm uses a hierarchical approach for the matrix storage and manipulation. This paper describes the assembly approach for the usual H and G matrices coming from BEM equations into a hierarchical coefficient matrix A H. The efficiency of the developed scheme is tested for a potential problem involving a 3D unitary cube, and then the method is applied to an electrostatic problem involving an anatomic model of the human body. This 3D example consisting of 80 000 degrees of freedom could easily be solved in a low specification PC.

Research paper thumbnail of Boundary element modeling of complex grounding systems: Study on current distribution

WIT Transactions on Modelling and Simulation, 2010

The assessment of current distribution induced along complex grounding systems has been undertake... more The assessment of current distribution induced along complex grounding systems has been undertaken using the corresponding antenna model and the set of Pocklington integro-differential equations for curved wires. The set of Pocklington equations is numerically handled via the Galerkin-Bubnov scheme of the Indirect Boundary Element Method (GB-IBEM) featuring the isoparametric elements. Some illustrative numerical results for the current distribution are presented in the paper.

Research paper thumbnail of Recovering current density from data on electric potential

Simulation of Electrochemical Processes III, 2009

In this paper, an inverse problem for galvanic corrosion in two-dimensional Laplace's equation wa... more In this paper, an inverse problem for galvanic corrosion in two-dimensional Laplace's equation was studied. The considered problem deals with experimental measurements on electric potential, where due to lack of data, numerical integration is impossible. The problem is reduced to the determination of unknown complex coefficients of approximating functions, which are related to the known potential and unknown current density. By employing continuity of those functions along subdomain interfaces and using condition equations for known data leads to over-determined system of linear algebraic equations which are subjected to experimental errors. Reconstruction of current density is unique. The reconstruction contains one free additive parameter which does not affect current density. The method is useful in situations where limited data on electric potential are provided.

Research paper thumbnail of 3D FEM temperature distribution analysis of the human eye exposed to laser radiation

Advanced Computational Methods and Experiments in Heat Transfer XI, 2010

This paper is an extension of a previously published work on thermal modelling of the human eye e... more This paper is an extension of a previously published work on thermal modelling of the human eye exposed to radiation by various lasers. The 2D model is now extended to 3D in order to give a more realistic representation of the human eye model when irradiated by laser. The model is based on space-time dependent Pennes' bio-heat transfer equation solved by the finite elements method featuring Galerking-Bubnov procedure. The results for the temperature field inside the eye could prove to be useful in minimising the possible damage to intraocular tissues during the ophthalmological procedures and also later in analysis of laser-tissue interaction mechanisms. Also, analysis of various parameters on the calculated temperature distribution is carried out.

Research paper thumbnail of Safety Assessment For Disposal Of HazardousWaste In Abandoned Underground Mines

Disposal of hazardous chemical waste in abandoned underground mines is believed to be an achievab... more Disposal of hazardous chemical waste in abandoned underground mines is believed to be an achievable, low risk and relatively cheap way of disposal of hazardous waste. The objective of the FP5 EC project Low Risk Disposal Technology (LowRiskDT) was to investigate the prerequisites for using this alternative, to outline suitable design and construction technology and to make a performance assessment with special respect to environmental safety and cost. Calculations were made of the isolating capacity of reference repositories in terms of the concentration of hazardous ion species appearing in the far-field groundwater. Relevant flow and dispersion models were applied to the reference cases representing different rock structures and flow path patterns. The release and migration of dissolved hazardous chemical species with special respect to groundwater protection are determined for the worst-case scenario. A numerical tool has been developed that can be used for analysis of transport ...

Research paper thumbnail of Using a Computational Galvanic Model in a Fracture Mechanics Framework to Improve Material Degradation Prediction

Using a Computational Galvanic Model in a Fracture Mechanics Framework to Improve Material Degradation Prediction

Corrosion, 2020

Research paper thumbnail of Temperature rise in the human body exposed to radiation from base station antennas

Thermal analysis of human expoure to base station antennas radiation is presented in this work. T... more Thermal analysis of human expoure to base station antennas radiation is presented in this work. The formulation is based on a simplified cylindrical representation of the human body. Knowing the internal electric field and related total absorbed power in the human body, a resulting thermal response of the body due to the exposure to high frequency (HF) radiation can be determined. The temperature rise in the body exposed to base stations antenna radiation is determined by solving the bio-heat transfer equation via both the dual reciprocity boundary element method (DR-BEM) and finite element method (FEM). The temperature rise in the body is found to be rather negligible.

Research paper thumbnail of Electromagnetic Modeling of the Human Body Exposed to Extremely Low Frequency (ELF) Electromagnetic Field

Electromagnetic Modeling of the Human Body Exposed to Extremely Low Frequency (ELF) Electromagnetic Field

Analytical modeling of the human body exposed to extremely low frequency electromagnetic radiatio... more Analytical modeling of the human body exposed to extremely low frequency electromagnetic radiation is presented in this article, which contribution is based on the comparison between different approximations. Cylindrical approximation is based on a theory of receiving antenna and presentation of the human body as a parasitic antenna exposed to an incident electric field. Through cylindrical approximation, the induced current inside the human body is calculated. This current is used for evaluating adverse health effects that electric field has on the human body. Different cases of exposure are considered, taking into account insulation between human body and the earth. Ellipsoidal approximation is used as a comparison to cylindrical. Finally, the comparison with the numerical model is made. Numerical model is based on Boundary Element Method (BEM) and the results obtained are shown to be in very good agreement.

Research paper thumbnail of Modelling Impressed Current Cathodic Protection of Storage Tanks

Modelling Impressed Current Cathodic Protection of Storage Tanks

This work is focused on the simulation of the type of ICCP system in which a grid of anode ribbon... more This work is focused on the simulation of the type of ICCP system in which a grid of anode ribbons and distribution bars, buried below the base of a tank, is supplied with power from a transformer rectifier unit. Current flows from the anode ribbons through the wet sand in which they are embedded, to the base of the tank, and then back to the TRU. The ICCP system is represented mathematically as a circuit including the TRU, distribution cables connecting it to a number of distribution bars, an array of anode ribbons welded to the distribution bars, and the return cable connecting the tank base to the return of the TRU. The electrical circuit equations are solved to determine current flow and electrical potential throughout the grid of anode ribbons and distribution bars. Current flow from the surfaces of the anode ribbons into the surrounding electrolyte, and from the electrolyte into the surface of the tank base, is described using polarization curves, which encapsulate the non-lin...

Research paper thumbnail of Application Of Computational Modeling To Predict The Effectiveness Of Cp On A Pccp Transmission Pipeline

Application Of Computational Modeling To Predict The Effectiveness Of Cp On A Pccp Transmission Pipeline

Prestressed Concrete Cylinder Pipe (PCCP) is a rigid pipe designed to take optimum advantage of t... more Prestressed Concrete Cylinder Pipe (PCCP) is a rigid pipe designed to take optimum advantage of the tensile strength of steel and of the compressive strength and corrosion inhibiting properties of concrete and is frequently used for water transmission. PCCP consists of a steel cylinder embedded in a concrete core, which is helically wrapped with high-strength, hard-drawn wire after curing. The wire is embedded in thick cement slurry and coated with a dense cement mortar. While the cement mortar and additional coatings usually protect the prestressing wires from corrosion, in certain circumstances chlorides can diffuse into the mortar and reach the wires. Therefore PCCP transmission pipelines can also be protected by CP systems to mitigate the risk of corrosion damage when chlorides are high in the soil. This paper describes a computer modeling study which was designed to determine the protection provided by a CP system, to evaluate different design options, and to optimize the desig...

Research paper thumbnail of Case Study of an ICCP Design and Installation for Well Casings Using Boundary Elements Software, Evaluating Different Deep Anode Architectures and Interference to Nearby Casings

Case Study of an ICCP Design and Installation for Well Casings Using Boundary Elements Software, Evaluating Different Deep Anode Architectures and Interference to Nearby Casings

Corrosion, 2016

Research paper thumbnail of Rock structure control of groundwater flow and stability – disposal of hazardous waste in abandoned mines

Rock structure control of groundwater flow and stability – disposal of hazardous waste in abandoned mines

Multibarrier isolation of hazardous waste is proposed by organizations and companies responsible ... more Multibarrier isolation of hazardous waste is proposed by organizations and companies responsible for underground disposal of such waste. The host rock of repositories is of majorimportance and cons ...