The 4D gravity or time lapse gravity has been used many reseracher to identify fluid injection in oil reservoir. The objective of this study is to find the better way in interpreting 4D gravity anomaly due to fluid injection around the reservoir. Radial Derivatives are derivative values of gravity anomalies against horizontal distances in the radial direction. Radial inversion is a two-dimensional inversion of lines with radial directions resulting in a 3-dimension model. Time lapse microgravity research have been performed in “X Oil Field” with amount of 604 data point covering area of 4000 m x 5000 m. This Radial derivative and Radial inversion have been aplied at an injection well of the X oil field. The yield show that 4D gravity anomaly value due to injection is 0.02 mGal to 0.36 mGal. Radial derivative value in the area is 0 micro Gal/cm to 0,012 mGal/meter. Radial inversion shows radius of fluid front movement is 304 meters to 1120 meters. Radial derivative and Radial inversion have been proven fairly good to identify injected fluid movement in the reservoir.
Gaddam et al-2017-journal_of_earth_system_science (1)Vinay G
1) The study develops seasonal sensitivity characteristics (SSCs) for four glaciers in Western Himalaya to quantify changes in specific mass balance from monthly temperature and precipitation variations.
2) Using the SSCs and climate reanalysis data, the study reconstructs the specific mass balance of the glaciers from 1900-2010, finding they experienced both positive and negative balances, except Naradu glacier which only lost mass.
3) A cumulative mass loss of -133 ± 21.5 meters water equivalent was estimated for the four glaciers over the observation period, making this the first record of Himalayan glacier mass balances over a century scale.
Unstable/Astatic Gravimeters and Marine Gravity SurveyRaianIslamEvan
This is a descriptive article on stable and unstable gravimeters. The article is mainly focused on LaCoste-Romberg and Worden gravimeters. Also, it includes marine gravity survey shortly.
- Abiotic controls, like precipitation and evaporation, dominate soil moisture spatiotemporal variability in wet climates, while biotic controls from vegetation become more important in Mediterranean climates.
- The relationship between the coefficient of variation (Cv) and mean soil moisture (Θ) was found to be unique and well described by an exponential or linear function for locations in Switzerland, but strong hysteretic cycles were observed for Mediterranean locations.
- Heterogeneity in soil properties increases Cv and tends to obscure any hysteresis, masking climatic and biotic controls on soil moisture variability. Heterogeneity can therefore hide the influences of climate and vegetation on soil moisture spatiotemporal patterns.
Geometric relaxation time of induced polarization fractal dimensionKhalid Al-Khidir
1) The document analyzes induced polarization relaxation times and fractal dimensions of sandstone samples from the Shajara Formation in Saudi Arabia to characterize the reservoirs.
2) Geometric and arithmetic relaxation times of induced polarization were calculated from pore distribution measurements and used to derive fractal dimensions.
3) The Shajara reservoirs were divided into three units - Lower, Middle, and Upper - based on the fractal dimension results and field observations. The fractal dimensions increased with increasing permeability.
Improving the Reliability of Synthetic S-Wave Extraction Using Biot-Gassman F...IJERA Editor
Usage of Castagna’s relation by mean the P-wave log directly in estimation of the S-wave log gives a large error
to the original S-wave log so that the result is not reliable for further analysis. This paper offers new method for
S-wave log estimation based Castagna’s relation which is combined with fluid replacement modeling method
based on Biot-Gassman substitution and the use of petro physical data as input. The S-wave log result of the
offered estimation method has a small error to the original S-wave log so that more reliable and accurate for
further analysis. The offered method could be used for S-wave log estimation in various litology such as sand,
limestone, dolomite and shale. The S-wave log result of the offered estimation method has successfully used for
cross plot analysis of Vp/Vs ratio as function of acoustic impedance and Gamma Ray for delineation of
sandstone bearing hydrocarbon from two different field.
Transients in Surface Tension Driven Flows in MicrogravityAatresh Karnam
It is well known fact that surface tension of a liquid plays a dominant role in microgravity conditions. A specific problem of interest is that of propellant acquisition in spacecraft where, in the absence of gravity the propellant mass has no preferential position unless special hardware are so devised as to keep the propellant at the tank outlet. For many such configurations, models are available to determine the equilibrium position of the liquid mass, but the transients involved in driving the liquid to this state from arbitrary initial state are rarely addressed. This becomes critical if one desires experimental verification of the models since microgravity times achievable in tests can be very limited. The present work addresses this issue by solving the flow inside the tank under the influence of surface tension. The numerical model with a generic approach is validated for a couple of known experimental configurations before making predictions for spacecraft propellant management in a specific configuration which aid propellant acquisition as well as gauging which becomes critical towards the end-of-life of the spacecraft.
Microgravity Flow Transients in the context of On-Board Propellant GaugingAatresh Karnam
It is well known that surface tension of a liquid has a decisive role in flow dynamics and the eventual equilibrium state, especially in confined flows under low gravity conditions and also in free surface flows. One such instance of a combination of these two cases where surface tension plays an important role is in the microgravity environment of a spacecraft propellant tank. In this specific case both propellant acquisition and residual propellant estimation are critical to the mission objectives particularly in the end-of-life phase. While there have been a few studies pertaining to the equilibrium state in given geometric configurations, the transient flow leading to final state from an initial arbitrary distribution of propellant is rarely described. The present study is aimed at analysing the dynamic behaviour of the liquids under reduced gravity through numerical simulation and also addresses the specific case of propellant flow transient in a cone-in-a-sphere type of tank configuration proposed by Lal and Raghunandan which is likely to result in both improved acquisition and life time estimation of spacecraft. While addressing this specific problem, the present work aims to study the transient nature of such surface tension driven flows in a general form as applicable to other similar problems also. Volume of Fluid (VOF) method for multiphase model in ANSYS FLUENT was adapted with suitable changes for generating numerical solutions to this problem.
Improving Distributed Hydrologocal Model Simulation Accuracy Using Polynomial...Putika Ashfar Khoiri
1) The document discusses applying the Polynomial Chaos Expansion (PCE) method to optimize parameters in distributed hydrological models and improve simulation accuracy.
2) PCE involves approximating a model output as a polynomial function of uncertain input parameters. It can efficiently estimate model outputs across the parameter space.
3) The author plans to use PCE to optimize soil-related parameters like layer thickness and hydraulic conductivity in a distributed hydrological model of the Ibo River catchment. Determining the optimal polynomial order for the model is a key future task.
Gaddam et al-2017-journal_of_earth_system_science (1)Vinay G
1) The study develops seasonal sensitivity characteristics (SSCs) for four glaciers in Western Himalaya to quantify changes in specific mass balance from monthly temperature and precipitation variations.
2) Using the SSCs and climate reanalysis data, the study reconstructs the specific mass balance of the glaciers from 1900-2010, finding they experienced both positive and negative balances, except Naradu glacier which only lost mass.
3) A cumulative mass loss of -133 ± 21.5 meters water equivalent was estimated for the four glaciers over the observation period, making this the first record of Himalayan glacier mass balances over a century scale.
Unstable/Astatic Gravimeters and Marine Gravity SurveyRaianIslamEvan
This is a descriptive article on stable and unstable gravimeters. The article is mainly focused on LaCoste-Romberg and Worden gravimeters. Also, it includes marine gravity survey shortly.
- Abiotic controls, like precipitation and evaporation, dominate soil moisture spatiotemporal variability in wet climates, while biotic controls from vegetation become more important in Mediterranean climates.
- The relationship between the coefficient of variation (Cv) and mean soil moisture (Θ) was found to be unique and well described by an exponential or linear function for locations in Switzerland, but strong hysteretic cycles were observed for Mediterranean locations.
- Heterogeneity in soil properties increases Cv and tends to obscure any hysteresis, masking climatic and biotic controls on soil moisture variability. Heterogeneity can therefore hide the influences of climate and vegetation on soil moisture spatiotemporal patterns.
Geometric relaxation time of induced polarization fractal dimensionKhalid Al-Khidir
1) The document analyzes induced polarization relaxation times and fractal dimensions of sandstone samples from the Shajara Formation in Saudi Arabia to characterize the reservoirs.
2) Geometric and arithmetic relaxation times of induced polarization were calculated from pore distribution measurements and used to derive fractal dimensions.
3) The Shajara reservoirs were divided into three units - Lower, Middle, and Upper - based on the fractal dimension results and field observations. The fractal dimensions increased with increasing permeability.
Improving the Reliability of Synthetic S-Wave Extraction Using Biot-Gassman F...IJERA Editor
Usage of Castagna’s relation by mean the P-wave log directly in estimation of the S-wave log gives a large error
to the original S-wave log so that the result is not reliable for further analysis. This paper offers new method for
S-wave log estimation based Castagna’s relation which is combined with fluid replacement modeling method
based on Biot-Gassman substitution and the use of petro physical data as input. The S-wave log result of the
offered estimation method has a small error to the original S-wave log so that more reliable and accurate for
further analysis. The offered method could be used for S-wave log estimation in various litology such as sand,
limestone, dolomite and shale. The S-wave log result of the offered estimation method has successfully used for
cross plot analysis of Vp/Vs ratio as function of acoustic impedance and Gamma Ray for delineation of
sandstone bearing hydrocarbon from two different field.
Transients in Surface Tension Driven Flows in MicrogravityAatresh Karnam
It is well known fact that surface tension of a liquid plays a dominant role in microgravity conditions. A specific problem of interest is that of propellant acquisition in spacecraft where, in the absence of gravity the propellant mass has no preferential position unless special hardware are so devised as to keep the propellant at the tank outlet. For many such configurations, models are available to determine the equilibrium position of the liquid mass, but the transients involved in driving the liquid to this state from arbitrary initial state are rarely addressed. This becomes critical if one desires experimental verification of the models since microgravity times achievable in tests can be very limited. The present work addresses this issue by solving the flow inside the tank under the influence of surface tension. The numerical model with a generic approach is validated for a couple of known experimental configurations before making predictions for spacecraft propellant management in a specific configuration which aid propellant acquisition as well as gauging which becomes critical towards the end-of-life of the spacecraft.
Microgravity Flow Transients in the context of On-Board Propellant GaugingAatresh Karnam
It is well known that surface tension of a liquid has a decisive role in flow dynamics and the eventual equilibrium state, especially in confined flows under low gravity conditions and also in free surface flows. One such instance of a combination of these two cases where surface tension plays an important role is in the microgravity environment of a spacecraft propellant tank. In this specific case both propellant acquisition and residual propellant estimation are critical to the mission objectives particularly in the end-of-life phase. While there have been a few studies pertaining to the equilibrium state in given geometric configurations, the transient flow leading to final state from an initial arbitrary distribution of propellant is rarely described. The present study is aimed at analysing the dynamic behaviour of the liquids under reduced gravity through numerical simulation and also addresses the specific case of propellant flow transient in a cone-in-a-sphere type of tank configuration proposed by Lal and Raghunandan which is likely to result in both improved acquisition and life time estimation of spacecraft. While addressing this specific problem, the present work aims to study the transient nature of such surface tension driven flows in a general form as applicable to other similar problems also. Volume of Fluid (VOF) method for multiphase model in ANSYS FLUENT was adapted with suitable changes for generating numerical solutions to this problem.
Improving Distributed Hydrologocal Model Simulation Accuracy Using Polynomial...Putika Ashfar Khoiri
1) The document discusses applying the Polynomial Chaos Expansion (PCE) method to optimize parameters in distributed hydrological models and improve simulation accuracy.
2) PCE involves approximating a model output as a polynomial function of uncertain input parameters. It can efficiently estimate model outputs across the parameter space.
3) The author plans to use PCE to optimize soil-related parameters like layer thickness and hydraulic conductivity in a distributed hydrological model of the Ibo River catchment. Determining the optimal polynomial order for the model is a key future task.
IRJET- Numerical Analysis for Nonlinear Consolidation of Saturated Soil using...IRJET Journal
This document presents a numerical method for analyzing one-dimensional nonlinear consolidation of saturated soil using the lattice Boltzmann method. The lattice Boltzmann-BGK model is used to simulate the nonlinear consolidation equation for saturated soil subjected to time-dependent loading under different boundary conditions. The multiscale Chapman-Enskog expansion is applied to derive the macroscopic nonlinear consolidation equation from the mesoscopic lattice Boltzmann equation. Numerical simulations are performed and found to agree well with available analytical solutions, demonstrating the validity of the proposed lattice Boltzmann method for analyzing nonlinear consolidation problems.
1. The document discusses applying cloud transformation technology to predict reservoir properties like porosity and permeability in thin reservoirs in the Songliao basin. Cloud transformation can minimize fitting errors between non-linear relationships of reservoir parameters better than conventional linear or quadratic functions.
2. The technique was applied to a study area in Mutou, Songliao basin to predict porosity distributions based on relationships defined through cloud transformation between lithology, wave impedance, and porosity. Results showed porosity simulations were consistent vertically and horizontally and matched over 80% of drilling data.
3. Cloud transformation provides a scientific method for reservoir property prediction that considers the range of possible values as a probability distribution rather than point values, improving on conventional
Statistical Tuning Chart for Mapping Porosity Thickness: a Case Study of Chan...TELKOMNIKA JOURNAL
Reservoir assessment is not only controlled by the structural framework but also stratigraphical
features. Stratigraphical interpretation, which is related to seismic amplitude interpretation, is used to
describe petrophysical aspects of channel sand reservoirs such as net porosity and thickness. This paper
aims to map the porosity thickness for a case study of channel sand bodies reservoir in the Kutei basin.
The study area is complex channel reservoir system that appears to occupy specific area within the
depositional system. The geometry of the sediment channel, which thins toward the channel margins,
makes this feature similar to be wedge model that could possibly be influenced by tuning effects. The
tuning effects introduce pitfall in interpreting high-quality reservoir that is affected by contrasts in acoustic
impedance. In order to distinguish high amplitude responses caused by tuning effects and acoustic
properties, the analysis of amplitude responses needs to be correlated to the reservoir thickness. The
statistical tuning chart is one of the techniques used to correlate amplitude responses and the reservoir
thickness. The application of this technique to real data sets shows net porosity thickness map over the
targeted reservoir. Thus, high-quality reservoir characterization can be performed to delineate geometric
framework of the reservoir.
This document discusses preparatory work for coupling reactive solute transport modeling with flow modeling in the Cathy model. The objectives are to develop a 3D coupled surface and subsurface flow and reactive solute transport model based on Cathy, validate it using field data from two hillslopes in France, and upscale the model from hillslope to catchment scale. An existing subsurface flow model (Cathy) and solute transport model (Tran3d) will be merged to allow modeling of non-steady state cases. The merged model will be validated using two test cases from literature and applied to a site in Beaujolais, France.
Characteristics of shock reflection in the dual solution domainSaif al-din ali
This document summarizes a numerical study that investigates the use of laser energy deposition to induce transitions between regular and Mach shock reflections in supersonic flow over dual wedge configurations. The study validated its numerical approach by comparing results to an experiment involving laser deposition in front of a sphere. Simulations then examined how varying the position and amount of laser energy deposition could influence transition characteristics in the dual solution domain over wedge configurations. Key findings included how transition time and occurrence depended on deposition parameters and position relative to the shock waves and wedges.
Advances in Rock Physics Modelling and Improved Estimation of CO2 Saturation, Giorgos Papageorgiou - Geophysical Modelling for CO2 Storage, Leeds, 3 November 2015
This study used elastic impedance inversion and pre-stack attribute analysis on 3D seismic data with limited well control to identify productive zones in an offshore Iranian reservoir. Poisson dampening factor and Lame parameters extracted from pre-stack simultaneous inversion effectively delineated hydrocarbon-bearing areas, validated by crossplots of elastic impedance volumes. The attribute analysis results at well locations were generalized to the full seismic volume since the reservoir was considered laterally homogeneous.
This document summarizes research on oblique shock waves that appear in supersonic carbon dioxide two-phase flow, as occurs in ejector refrigeration cycles. It presents:
1) Theoretical analyses showing that two types of oblique shock waves can occur - weak shocks where flow remains supersonic, and strong shocks with large pressure recovery and subsonic flow.
2) An experiment using a carbon dioxide two-phase flow channel to observe these shock waves.
3) Equations governing compressible two-phase flow and the conditions under which strong and weak oblique shock waves form, to compare with experimental results.
The document discusses various mechanisms of mass transfer including molecular diffusion in gases and liquids, mass transfer in turbulent and laminar flow, and interphase mass transfer. Molecular diffusion is the movement of molecules due to a concentration gradient. Fick's law describes the rate of diffusion. Mass transfer in fluids occurs across a boundary layer near the surface via molecular diffusion or eddies. Interphase transfer theories include the two film theory, penetration theory, and surface renewal theory which describe mass transfer across interfaces.
Biomass is considered as a potential source of energy production.Gasification can be employed to convert
dilute biomass energy source in to gaseous products holding concentrated form of energy. A steady state model for fluidized
bed biomass gasifier is developed based on reaction kinetics and hydrodynamic aspects of fluidization. The presence of
sorbent for absorption of carbon dioxide from the product gas is also incorporated in the model.The developed model
predicts the variation of syngas composition, temperature, pressure and velocity along the height of gasifier. Experiments
were carried out in a lab scale fluidized bed biomass gasifier and the results were used to validate the model.An increase of
50.35% in H2 mole fraction and a decrease of 50.88 % in CO2 mole fraction were observed when CaO was used as the
sorbent.
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 2.2 Molecular diffusion
This document discusses gas chromatography (GC), which separates compounds that can be vaporized without decomposing. It has two types depending on the stationary phase: gas-solid chromatography (GSC) and gas-liquid chromatography (GLC). The distribution of analytes between phases is expressed by the distribution constant K. Plate theory and rate theory, including the Van Deemter equation, are presented to describe column efficiency and factors influencing peak broadening such as eddy diffusion, longitudinal diffusion, and mass transfer under non-equilibrium conditions.
Analytical solution for Transient MHD flow through a Darcian porous regime in...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document discusses convective mass transfer and mass transfer coefficients. It defines convective mass transfer as the rapid transfer of mass that occurs when there is motion in the transfer medium compared to the slower process of molecular diffusion. Mass transfer coefficients are introduced to simplify calculations of mass transfer rates. Different types of mass transfer coefficients are presented based on whether they are used for gases or liquids, and whether they are expressed in terms of concentrations, mole fractions, or partial pressures. Approximations for typical values of mass transfer coefficients in gas and liquid phases are provided.
The use of Cellular Automata is extended in various disciplines for the modeling of complex system procedures. Their inherent simplicity and their natural parallelism make them a very efficient tool for the simulation of large scale physical phenomena. We explore the framework of Cellular Automata to develop a physically based model for the spatial and temporal prediction of shallow landslides. Particular weight is given to the modeling of hydrological processes in order to investigate the hydrological triggering mechanisms and the importance of continuous modeling of water balance to detect timing and location of soil slips occurrences. Specifically, the 3D flow of water and the resulting water balance in the unsaturated and saturated zone is modeled taking into account important phenomena such as hydraulic hysteresis and evapotranspiration. In this poster the hydrological component of the model will be presented and tested against well established benchmark experiments [Vauclin et al, 1975; Vauclin et al, 1979]. Furthermore, we investigate the applicability of incorporating it in a hydrological catchment model for the prediction (temporal and spatial) of rainfall-triggered shallow landslides.
Numerical Study Of Flue Gas Flow In A Multi Cyclone SeparatorIJERA Editor
The removal of harmful particulate matter from power plant flue gas is of critical importance to the environment and its inhabitants. The present work illustrates the use of multi-cyclone separators to remove the particulate matter from the bulk of the gas exhausted to the atmosphere. The method has potential to replace conventional systems like electrostatic precipitator due to inherent low power requirement and low maintenance. A parametric model may be employed to design the system based on the requirement of the power station. The present work describes the simulation of flue gas flow through a cyclonic separator. A Finite volume approach has been used and the pressure-velocity coupling is resolved using the SIMPLE algorithm. Discrete phase model is used to inject solid particles from inlet. In this numerical analysis a cluster of four cyclonic separators are considered. Comparisons are made between the available experimental results and the computational work for validation of the numerical models and schemes employed in the work. The separation efficiency and particle trajectories are shown and found comparable to similar cases from literature. The experimental results correlate well for the model under consideration.
The document discusses the Van-Deemter equation, which describes the relationship between column efficiency and linear velocity in chromatography. It explains the three main sources of band broadening: A) eddy diffusion, which increases with larger particle size; B) longitudinal diffusion, which increases at low flow rates; and C) resistance to mass transfer, which increases with thicker stationary or mobile phases or smaller particle size. The Van-Deemter equation can be used to optimize the mobile phase velocity and compare performance of different stationary phases by measuring peak broadening (HETP) at varying flow rates.
This paper presents a joint analysis of surface wave and microgravity surveys to estimate S-wave velocity and density models of the subsurface. Surface wave testing and microgravity surveys were conducted along a 205m survey line to map a buried channel filled with soft sediments. An S-wave velocity model was derived from surface wave data using cross-correlation analysis. Gravity data was then analyzed based on the S-wave model, converting it to a density model using soil properties. A least squares method was used to modify the density model to reduce residuals between calculated and observed gravity, resulting in a clear low-density area matching the low S-wave velocity channel.
This document summarizes a study that used a coupled wave and tidal flow model to assess marine energy resources in the Orkney Islands and Pentland Firth region of Scotland. The model was calibrated and validated against measurement data from buoys and acoustic Doppler current profilers. Model results for current velocity at different depths correlated well with measurement data from three sites. The coupled model provides a tool for assessing the combined wave and tidal energy resources in the region.
9 17 fujisawa et al -seags e journal 2013-06chakfarmer
The document discusses an experimental study that investigated the relationship between seepage force and the velocity of sand particles during sand boiling. The study used silica sand and measured the migration velocities of seepage water and sand particles by calculating discharge amounts. The results revealed that:
1) The equilibrium of forces (gravity, buoyancy, fluid-particle interaction) can be used to estimate velocities of sand particles subjected to upward seepage flow.
2) The seepage force needed for horizontal transport of sand tends to decrease as the velocity of sand particles increases.
3) Previous studies on seepage failure focused on critical hydraulic gradients or velocities, but this study provides insights into how sand transport develops during
IRJET- Numerical Analysis for Nonlinear Consolidation of Saturated Soil using...IRJET Journal
This document presents a numerical method for analyzing one-dimensional nonlinear consolidation of saturated soil using the lattice Boltzmann method. The lattice Boltzmann-BGK model is used to simulate the nonlinear consolidation equation for saturated soil subjected to time-dependent loading under different boundary conditions. The multiscale Chapman-Enskog expansion is applied to derive the macroscopic nonlinear consolidation equation from the mesoscopic lattice Boltzmann equation. Numerical simulations are performed and found to agree well with available analytical solutions, demonstrating the validity of the proposed lattice Boltzmann method for analyzing nonlinear consolidation problems.
1. The document discusses applying cloud transformation technology to predict reservoir properties like porosity and permeability in thin reservoirs in the Songliao basin. Cloud transformation can minimize fitting errors between non-linear relationships of reservoir parameters better than conventional linear or quadratic functions.
2. The technique was applied to a study area in Mutou, Songliao basin to predict porosity distributions based on relationships defined through cloud transformation between lithology, wave impedance, and porosity. Results showed porosity simulations were consistent vertically and horizontally and matched over 80% of drilling data.
3. Cloud transformation provides a scientific method for reservoir property prediction that considers the range of possible values as a probability distribution rather than point values, improving on conventional
Statistical Tuning Chart for Mapping Porosity Thickness: a Case Study of Chan...TELKOMNIKA JOURNAL
Reservoir assessment is not only controlled by the structural framework but also stratigraphical
features. Stratigraphical interpretation, which is related to seismic amplitude interpretation, is used to
describe petrophysical aspects of channel sand reservoirs such as net porosity and thickness. This paper
aims to map the porosity thickness for a case study of channel sand bodies reservoir in the Kutei basin.
The study area is complex channel reservoir system that appears to occupy specific area within the
depositional system. The geometry of the sediment channel, which thins toward the channel margins,
makes this feature similar to be wedge model that could possibly be influenced by tuning effects. The
tuning effects introduce pitfall in interpreting high-quality reservoir that is affected by contrasts in acoustic
impedance. In order to distinguish high amplitude responses caused by tuning effects and acoustic
properties, the analysis of amplitude responses needs to be correlated to the reservoir thickness. The
statistical tuning chart is one of the techniques used to correlate amplitude responses and the reservoir
thickness. The application of this technique to real data sets shows net porosity thickness map over the
targeted reservoir. Thus, high-quality reservoir characterization can be performed to delineate geometric
framework of the reservoir.
This document discusses preparatory work for coupling reactive solute transport modeling with flow modeling in the Cathy model. The objectives are to develop a 3D coupled surface and subsurface flow and reactive solute transport model based on Cathy, validate it using field data from two hillslopes in France, and upscale the model from hillslope to catchment scale. An existing subsurface flow model (Cathy) and solute transport model (Tran3d) will be merged to allow modeling of non-steady state cases. The merged model will be validated using two test cases from literature and applied to a site in Beaujolais, France.
Characteristics of shock reflection in the dual solution domainSaif al-din ali
This document summarizes a numerical study that investigates the use of laser energy deposition to induce transitions between regular and Mach shock reflections in supersonic flow over dual wedge configurations. The study validated its numerical approach by comparing results to an experiment involving laser deposition in front of a sphere. Simulations then examined how varying the position and amount of laser energy deposition could influence transition characteristics in the dual solution domain over wedge configurations. Key findings included how transition time and occurrence depended on deposition parameters and position relative to the shock waves and wedges.
Advances in Rock Physics Modelling and Improved Estimation of CO2 Saturation, Giorgos Papageorgiou - Geophysical Modelling for CO2 Storage, Leeds, 3 November 2015
This study used elastic impedance inversion and pre-stack attribute analysis on 3D seismic data with limited well control to identify productive zones in an offshore Iranian reservoir. Poisson dampening factor and Lame parameters extracted from pre-stack simultaneous inversion effectively delineated hydrocarbon-bearing areas, validated by crossplots of elastic impedance volumes. The attribute analysis results at well locations were generalized to the full seismic volume since the reservoir was considered laterally homogeneous.
This document summarizes research on oblique shock waves that appear in supersonic carbon dioxide two-phase flow, as occurs in ejector refrigeration cycles. It presents:
1) Theoretical analyses showing that two types of oblique shock waves can occur - weak shocks where flow remains supersonic, and strong shocks with large pressure recovery and subsonic flow.
2) An experiment using a carbon dioxide two-phase flow channel to observe these shock waves.
3) Equations governing compressible two-phase flow and the conditions under which strong and weak oblique shock waves form, to compare with experimental results.
The document discusses various mechanisms of mass transfer including molecular diffusion in gases and liquids, mass transfer in turbulent and laminar flow, and interphase mass transfer. Molecular diffusion is the movement of molecules due to a concentration gradient. Fick's law describes the rate of diffusion. Mass transfer in fluids occurs across a boundary layer near the surface via molecular diffusion or eddies. Interphase transfer theories include the two film theory, penetration theory, and surface renewal theory which describe mass transfer across interfaces.
Biomass is considered as a potential source of energy production.Gasification can be employed to convert
dilute biomass energy source in to gaseous products holding concentrated form of energy. A steady state model for fluidized
bed biomass gasifier is developed based on reaction kinetics and hydrodynamic aspects of fluidization. The presence of
sorbent for absorption of carbon dioxide from the product gas is also incorporated in the model.The developed model
predicts the variation of syngas composition, temperature, pressure and velocity along the height of gasifier. Experiments
were carried out in a lab scale fluidized bed biomass gasifier and the results were used to validate the model.An increase of
50.35% in H2 mole fraction and a decrease of 50.88 % in CO2 mole fraction were observed when CaO was used as the
sorbent.
Slides for the eLearning course Separation and purification processes in biorefineries (https://open-learn.xamk.fi) in IMPRESS project (https://www.spire2030.eu/impress).
Section: Mass transfer processes
Subject: 2.2 Molecular diffusion
This document discusses gas chromatography (GC), which separates compounds that can be vaporized without decomposing. It has two types depending on the stationary phase: gas-solid chromatography (GSC) and gas-liquid chromatography (GLC). The distribution of analytes between phases is expressed by the distribution constant K. Plate theory and rate theory, including the Van Deemter equation, are presented to describe column efficiency and factors influencing peak broadening such as eddy diffusion, longitudinal diffusion, and mass transfer under non-equilibrium conditions.
Analytical solution for Transient MHD flow through a Darcian porous regime in...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document discusses convective mass transfer and mass transfer coefficients. It defines convective mass transfer as the rapid transfer of mass that occurs when there is motion in the transfer medium compared to the slower process of molecular diffusion. Mass transfer coefficients are introduced to simplify calculations of mass transfer rates. Different types of mass transfer coefficients are presented based on whether they are used for gases or liquids, and whether they are expressed in terms of concentrations, mole fractions, or partial pressures. Approximations for typical values of mass transfer coefficients in gas and liquid phases are provided.
The use of Cellular Automata is extended in various disciplines for the modeling of complex system procedures. Their inherent simplicity and their natural parallelism make them a very efficient tool for the simulation of large scale physical phenomena. We explore the framework of Cellular Automata to develop a physically based model for the spatial and temporal prediction of shallow landslides. Particular weight is given to the modeling of hydrological processes in order to investigate the hydrological triggering mechanisms and the importance of continuous modeling of water balance to detect timing and location of soil slips occurrences. Specifically, the 3D flow of water and the resulting water balance in the unsaturated and saturated zone is modeled taking into account important phenomena such as hydraulic hysteresis and evapotranspiration. In this poster the hydrological component of the model will be presented and tested against well established benchmark experiments [Vauclin et al, 1975; Vauclin et al, 1979]. Furthermore, we investigate the applicability of incorporating it in a hydrological catchment model for the prediction (temporal and spatial) of rainfall-triggered shallow landslides.
Numerical Study Of Flue Gas Flow In A Multi Cyclone SeparatorIJERA Editor
The removal of harmful particulate matter from power plant flue gas is of critical importance to the environment and its inhabitants. The present work illustrates the use of multi-cyclone separators to remove the particulate matter from the bulk of the gas exhausted to the atmosphere. The method has potential to replace conventional systems like electrostatic precipitator due to inherent low power requirement and low maintenance. A parametric model may be employed to design the system based on the requirement of the power station. The present work describes the simulation of flue gas flow through a cyclonic separator. A Finite volume approach has been used and the pressure-velocity coupling is resolved using the SIMPLE algorithm. Discrete phase model is used to inject solid particles from inlet. In this numerical analysis a cluster of four cyclonic separators are considered. Comparisons are made between the available experimental results and the computational work for validation of the numerical models and schemes employed in the work. The separation efficiency and particle trajectories are shown and found comparable to similar cases from literature. The experimental results correlate well for the model under consideration.
The document discusses the Van-Deemter equation, which describes the relationship between column efficiency and linear velocity in chromatography. It explains the three main sources of band broadening: A) eddy diffusion, which increases with larger particle size; B) longitudinal diffusion, which increases at low flow rates; and C) resistance to mass transfer, which increases with thicker stationary or mobile phases or smaller particle size. The Van-Deemter equation can be used to optimize the mobile phase velocity and compare performance of different stationary phases by measuring peak broadening (HETP) at varying flow rates.
This paper presents a joint analysis of surface wave and microgravity surveys to estimate S-wave velocity and density models of the subsurface. Surface wave testing and microgravity surveys were conducted along a 205m survey line to map a buried channel filled with soft sediments. An S-wave velocity model was derived from surface wave data using cross-correlation analysis. Gravity data was then analyzed based on the S-wave model, converting it to a density model using soil properties. A least squares method was used to modify the density model to reduce residuals between calculated and observed gravity, resulting in a clear low-density area matching the low S-wave velocity channel.
This document summarizes a study that used a coupled wave and tidal flow model to assess marine energy resources in the Orkney Islands and Pentland Firth region of Scotland. The model was calibrated and validated against measurement data from buoys and acoustic Doppler current profilers. Model results for current velocity at different depths correlated well with measurement data from three sites. The coupled model provides a tool for assessing the combined wave and tidal energy resources in the region.
9 17 fujisawa et al -seags e journal 2013-06chakfarmer
The document discusses an experimental study that investigated the relationship between seepage force and the velocity of sand particles during sand boiling. The study used silica sand and measured the migration velocities of seepage water and sand particles by calculating discharge amounts. The results revealed that:
1) The equilibrium of forces (gravity, buoyancy, fluid-particle interaction) can be used to estimate velocities of sand particles subjected to upward seepage flow.
2) The seepage force needed for horizontal transport of sand tends to decrease as the velocity of sand particles increases.
3) Previous studies on seepage failure focused on critical hydraulic gradients or velocities, but this study provides insights into how sand transport develops during
Crustal Structure from Gravity and Magnetic Anomalies in the Southern Part of...Editor IJCATR
The gravity and magnetic data along the profile across the southern part of the Cauvery basin have been
collected and the data is interpreted for crustal structure depths.The first profile is taken from Karikudito
Embalecovering a distance of 50 km. The gravity lows and highs have clearly indicated various sub-basins and ridges.
The density logs from ONGC, Chennai, show that the density contrast decreases with depth in the sedimentary basin,
and hence, the gravity profiles are interpreted using variable density contrast with depth. From the Bouguer gravity
anomaly, the residual anomaly is constructed by graphical method correlating with well data and subsurface geology.
The residual anomaly profiles are interpreted using polygon and prismatic models. The maximum depths to the granitic
gneiss basement are obtained as 3.00 km. The regional anomaly is interpreted as Moho rise towards coast. The
aeromagnetic anomaly profiles are also interpreted for charnockite basement below the granitic gneiss group of rocks
using prismatic model.
Crustal Structure from Gravity and Magnetic Anomalies in the Southern Part of...Editor IJCATR
This document summarizes a study that used gravity and magnetic data to interpret crustal structure in the southern part of the Cauvery Basin in India. Gravity and magnetic data were collected along profiles perpendicular to tectonic features in the basin. The gravity data was used to interpret sediment thickness and basement depths, finding maximum sediment depths of 3 km. It was also used to interpret Moho depths, finding the Moho rises towards the coast. Magnetic data was interpreted to identify a charnockite basement below the granitic gneiss basement at depths of 0-8 km. The study provides new insights into crustal structure in this region based on integrated analysis of gravity and magnetic anomalies.
Effects of antifouling technology application on Marine ecological environment
Thermocline Model for Estimating Argo Sea Surface Temperature
Applications of Peridynamics in Marine Structures
Thermal and Structural Behaviour of Offshore Structures with Passive Fire Protection
Functionally graded material and its application to marine structures
Time Evolution of Density Parameters for Matter and Dark Energy and their Int...IJASRD Journal
In the framework of Brans-Dicke (BD) theory, the first part of the present study determines the time dependence of BD parameter, energy density and Equation of State (EoS) parameter of the cosmic fluid in a universe expanding with acceleration, preceded by a phase of deceleration. For this purpose, a scale factor has been so chosen that the deceleration parameter, obtained from it, shows a signature flip with time. Considering the dark energy to be responsible for the entire pressure, the time evolution of energy parameters for matter and dark energy and the EoS parameter for dark energy have been determined. A model for an effective interaction term, between matter and dark energy, has been proposed and calculated. Its negative value at the present time indicates conversion of matter into dark energy. Using this term, the time dependence of the rates of change of matter and dark energy has been determined. It is found that the nature of dependence of the scalar field upon the scale factor plays a very important role in governing the time evolution of the cosmological quantities studied here. The present study provides us with a simple way to determine the time evolution of dark energy for a homogeneous and isotropic universe of zero spatial curvature, without involving any self-interaction potential or cosmological constant in the formulation.
There are various factors which effect on spectrum of earthquake such as:
soil type, magnitude of earthquake, distance to earthquake center, type of fault,
duration and damping of earthquake. The research was aimed to investigate the
effects of soil on the spectrum of earthquake. Therefore, several accelerograms for
three different locations around the world have been selected from Berkeley
University website. Then the selected accelerograms were scaled up with number 1
for scaling the spectrums. The spectrums of accelerograms and the records of
earthquake were drawn by seismosignal software. Finally, the effect of different soil
were investigated on the spectrum of response earthquake. For increasing the
accuracy of results, similar effective parameter have been selected in choosing of
accelerograms. Results of the research were as follows; the domain of spectrum was
higher due to increasing the hardness of soil in harez um similar design factor in low
periods and the domain of spectrum was higher due to increasing the softness of soil
in higher periods. The diagrams are more gatherer and possess a greater amount in
harder soil and are is more extent and possess a lower amount in the softer soil.
Impact of gravity on fluid mechanics modelsDrAamirraza204
This document discusses the impact of gravity on fluid mechanics models. It begins by noting that while fluid mechanics formulas treat gravity as a constant, gravity actually varies depending on factors like the distribution of mass inside the Earth, altitude, and topography. The document then presents methodology for analyzing how errors in variables like empirical coefficients propagate through hydraulic models. It applies this methodology to models for bed shear stress and ogee spillways, finding that treating gravity as strictly constant can underestimate the real variation in gravity and thus the variation in model results. It concludes that gravity should not be treated as a true constant, and more accurate gravity data specific to a location is needed for hydraulic models intended to last for decades.
A New geotechnical method for natural slope exploration and analysisRasika Athapaththu
Geotechnical investigation of natural slopes is challengeable especially when
natural slopes having higher gradients and access is difficult. Also, it is even more prob-
lematic to find the shear strength parameters spatially to evaluate the stability of slopes as
most of the methods available to find the shear strength parameters in the literature are
uneconomical or such methods cannot be applied in vegetated slopes. Recently, authors
have conducted a series of in situ investigations based on the newly developed lightweight
dynamic cone penetrometer to examine its applicability in analyzing the slopes covered
with weathering remnants of decomposed granite. Six patterns were identified based on the
penetration resistance varies with the depth. Spatial variability analysis conducted on
different grid spaces showed that the coefficient of variation of cone resistance varies from
0 to 35 %. Semi-variogram analysis showed that the Spherical Models can be used to
evaluate the spatial variability of weathering remnants of decomposed granite. A series of
laboratory calibration tests based on the lightweight dynamic cone penetration tests and
direct shear tests with pore pressure measurements were conducted at different void ratios
and degrees of saturation. Based on the laboratory calibration test results, a method to
determine the void ratio, e, from the data of qd was presented. Based on this, two formulas
to evaluate the shear strength parameters, apparent cohesion and friction angle, were
established with the cone resistance and degree of saturation. Slight modification was
proposed in evaluating the apparent cohesion with respect to the different fine content in
the soils. As a whole, the proposed method can be successfully applied to individual slopes
to determine the profile thickness and to evaluate the shear strength parameters spatially.
Based on this, hazard assessment of individual slopes can be made.
This document describes an extension of the SRICOS method for predicting scour depth at bridge piers. The extended method, called E-SRICOS, accounts for variable flow velocities over time (velocity-time histories) and multilayer soil stratigraphy. It accumulates the effects of different velocities and sequences through soil layers to predict scour depth. The document outlines the E-SRICOS algorithms and procedures. It also presents a simplified version, S-SRICOS, and compares predictions of both methods to measurements at eight bridge sites in Texas.
1. The study area located in the Songliao Basin contains thin and laterally discontinuous reservoirs that are difficult to predict using conventional seismic inversion methods.
2. Coherent and frequency division attributes were used to qualitatively predict reservoir distribution, showing the sand bodies are concentrated in central bands with different orientations for different formations.
3. Geostatistical inversion was used to quantitatively predict reservoir distribution, generating multiple equally probable impedance models that match well logging data and seismic data, accurately depicting the reservoir distribution rules in the study area.
Yasir Bashir is proposing research on using wave theory to improve seismic imaging of fractured basement in the Malay Basin. The research will develop and apply depth migration algorithms to better define faults and fractures in the heterogeneous basement. Preliminary results show wave equation migration provides better illumination of dipping layers than Kirchhoff PSTM. The research aims to identify the best methods for imaging complex fractured basement and boundaries poorly resolved by current techniques.
FIELD AND THEORETICAL ANALYSIS OF ACCELERATED SETTLEMENT USING VERTICAL DRAINS ijiert bestjournal
This document discusses accelerated settlement of soft soils using vertical drains. It provides background on consolidation theories proposed by Terzaghi and Biot. It also reviews literature on three-dimensional consolidation analysis and the use of vertical drains to reduce drainage paths and accelerate settlement. Case studies evaluating methods to determine field-to-laboratory coefficients of consolidation are presented. The ratio of field to lab coefficients of consolidation has been found to range widely from 15 to 55 depending on site-specific soil properties and drainage conditions.
Enumeration and validation of hydrodynamic characteristics over plane and seIAEME Publication
This document summarizes a numerical study that simulated wave generation, propagation, and run-up over plane and serrated slopes with varying angles and wave heights. The study used the FUNWAVE model to simulate waves generated by a piston wavemaker and calculate dimensionless parameters like maximum run-up and reflection coefficient. Results found run-up was higher for a 30-degree slope and lower for a 45-degree slope. Slopes with serrations reduced run-up and reflection coefficient by around 30% and 20% respectively compared to plane slopes. The bed friction coefficient for serrated slopes was quantified using a Navier-Stokes solver.
On The Form Factor Prediction Of A Displacement Type Vessel: JBC CaseIsmail Topal
This document summarizes a study on predicting the form factor of a displacement type vessel (JBC hull) using computational fluid dynamics (CFD). Single-phase CFD simulations were performed for the JBC hull at various velocities within the Prohaska range. The form factor, which represents the ratio of viscous pressure force to frictional force, was calculated from the simulations and found to depend on Reynolds number, contrary to Prohaska's theory of independence. Frictional force results matched well with empirical ITTC formulas. The study aims to further investigate scale effects on form factor prediction.
This document summarizes a study on predicting the form factor of a ship hull through computational fluid dynamics simulations. Researchers conducted single-phase CFD simulations of flow around a Japanese Bulk Carrier hull model at various velocities within the Prohaska range. They evaluated mesh dependency, calculated friction coefficients compared to empirical data, and analyzed the effect of Reynolds number on predicted form factors. The study found that the form factor depends on ship velocity, contrary to Prohaska's theory, and suggests further investigation of scale effects on form factor predictions.
Field and Theoretical Analysis of Accelerated Consolidation Using Vertical Dr...inventionjournals
Mumbai is the region consisting of soft compressible marine clay deposits. There are several construction problems on such soils and thus ground improvement is need to be carried out. Vertical drains is generally preferred technique as accelerated settlement is achieved during the construction phase itself if planned accordingly. The concept of vertical drains is based on the theory of three dimensional consolidation as described by Terzaghi (1943). Based on this concept, a consolidation programme is developed and an attempt is made to determine the field to laboratory coefficient of vertical consolidation ratio by Taylor’s Square Root of Time Method and Casagrande’s Logarithm of Time Fitting Method for this region. Based on this, the rate of consolidation and time required for consolidation in the field can be determined knowing the consolidation parameters. Equations are developed by using output of the programme and it is explained.
This document discusses modeling groyne placement on river bends based on sedimentation analysis using numerical simulation with the finite difference method. The goal is to determine optimal groyne placement by considering sediment accumulation volumes in groyne fields.
The study plans to simulate 450 cases combining various groyne positions, lengths, flow velocities, bend radii, and suspended sediment concentrations. Conservation equations for mass and momentum will be used to develop the mathematical model. Validation and verification processes will evaluate the agreement between experimental data and model predictions.
Regression analysis of simulation results will determine suitability coefficients to obtain relationships between parameters like Froude number and groyne length, providing guidance on best distances between groynes. The numerical model aims
Similar to Radial Derivative and Radial Inversion for Interpreting 4D Gravity Anomaly Due to Fluids Injection Around Reservoir (20)
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
This document describes using a snake optimization algorithm to tune the gains of an enhanced proportional-integral controller for congestion avoidance in a TCP/AQM system. The controller aims to maintain a stable and desired queue size without noise or transmission problems. A linearized model of the TCP/AQM system is presented. An enhanced PI controller combining nonlinear gain and original PI gains is proposed. The snake optimization algorithm is then used to tune the parameters of the enhanced PI controller to achieve optimal system performance and response. Simulation results are discussed showing the proposed controller provides a stable and robust behavior for congestion control.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
Adaptive segmentation algorithm based on level set model in medical imagingTELKOMNIKA JOURNAL
For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
Automatic channel selection using shuffled frog leaping algorithm for EEG bas...TELKOMNIKA JOURNAL
Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
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in the Tuzgolu basin, Anatolia, Turkey [13]. Tatchtum, make geological tilt models in various
shapes, the anomaly respon and differentiated responses horizontally. This method was tested
in the Foumbon fault zone in Cameroon [14]. Chijun, measure vertical derivatives directly to get
a more accurate geoid value up to the order in centimeter level [15]. Aku, using vertical
derivative analysis to determine lithological vertical boundaries to sharpen the analysis of
gravitational interpretation in Gusau, Nigeria [16]. Askari, using the slope angle of the total
normalized derivative of the gravity anomaly to detect geological structural boundaries. This
method has been performed in the Sea of Oman, southeast of Iran [17]. Wahyudi, use vertical
derivatives from 3D gravity data for interpretation of geological structures. This method has
been tested in a very wide area, namely Central Java, East Java and Madura [18]. Pasteka
dkk., using derivative transformations from Bouguer anomalies for geological interpretation. This
method test was carried out in a very large area in Slovakia [19].
The world's oil demand is always increasing over time, while oil availability is running
low. Efforts to fulfill oil demand are performed by exploring new oil resources and optimizing on
producing oil reservoirs wich also well known as Enhancement Oil Recovery (EOR). One way to
increase production is injecting fluids into the reservoir. This fluid will move away from the
injection well and push the oil toward the production well. In the fluid injection process, the
density change of the pore fluid mass will result in a 4D gravity anomaly. Time lapse gravity
anomaly due to injection is the gravity value difference of post-injection with pre- injection. The
reservoir model and the 4D gravity response due to the fluids injection is shown in Figure 1. The
4D anomaly is positive because the density of injected fluid (water) is graeter than the oil filling
the pore.
Figure 1. Reservoir model and the 4D gravity response due to fluids injection in reservoir
The identification of fluid injection in reservoir using gravity method has been
conducted by many researchers. The use of this method is divided into two major parts of the
method of gravity on the surface and gravity of the well hole. Vasilevskiy et al used the gravity
data of the well-hole by interpretation through inversion [20]. Sarkowi made the interpretation of
surface gravity with the forward model [21], while Zuhdi et al made the same way by performing
radial derivative as shown in Figure 2 (a) [22]. The main problem of 4D gravity in identification of
fluid injection in reservoir is the difficulties to identify contact of injected fluid and pre-injection
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fluid. To solve this main problem authors propose radial derivatives and radial inversion. The
objective of this research is to construct computer program of radial derivative and radial
inversion of 4D gravity anomaly and show the abilty to show boundary of density contrast in
injected reservoir. The data was taken with Lacoste Romberg type 504 and Scintrex C 63,
consist of 604 measurement point covering area of 4000 mx5000 m, in 3 periods ie. January,
May and September in 2003. Radial derivative and radial inversion have been performed in the
part of the area covering 1000m x 1000m with an injection well as the center.
2. Research Method
2.1. Time Lapse Micro Gravity Method
According to Kadir, a 3-dimensional object with a mass density distribution (α,β,γ),
gives the effect of gravity at point P(x,y,z) on the surface within a given time interval (t) given
by [23]:
(1)
In (1) if the change of gravity anomaly only depens on density change (no geometrical
change), then it can be approximated by:
g(x,y,z,t) κ.(x,y,z,t) (2)
where κ is a constant corresponding to the geometry and volume of anomaly source objects,
whereas:
g(x,y,z,t)=g(x,y,z,t’)-g(x,y,z,t) (3)
g(x,y,z,t) is a gravity change related to density changes due to fluid injection in reservoir. If
pore volume is filled with oil at time t, and there is a replacement of oil with injected fluid at time
t, then the density change is given by the (4) [24]:
Δ = ’ - = Φ (f - o) (So-1) (4)
where f is density of injected fluid and o is density of oil. Oil saturation So is defined as the
ratio of volume Vm to the overall pore volume of Vp, and Φ is the total porosity.
Δg = k Φ (f - o) (So-1) (5)
by replacing So with Vo / Vp, (5) becomes:
Δg = Φ (f - o) {(Vo/Vp) - 1} (6)
the anomaly g will be positive because the oil (low density) is replaced with water (higher
density). If the injected fluid has bigger density, its time lapse anomaly will be positive.
2.2. Radial Derivative
Radial derivative is a derivative of the gravity anomaly value to the horizontal distance
with the radial direction of a particular point. The horizontal derivative of a gravitational anomaly
is the derivative of the gravity value in the direction of a particular straight line. If the straightline
cuts perpendicular to a contrast density boundary, the derivative value will be of great value. For
these purposes radial derivatives are made. The radial derivative center point is chosen based
on the center of anomaly.
Radial derivatives will be easier to perform in vertical cylindrical coordinates. The gravity
anomaly value Δgz (x, y, z) caused by the density anomaly Δρ (α, β, γ) is written as:
3
2 2 2 20
, , ,
, , ,
t z
g x y z t K d d d
x y z
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(7)
can be converted into vertical cylindrical coordinates, so that Δgz (x, y, z) becomes Δgz (R, z, λ)
and Δρ (R ', z', λ '), with relation [25]: x = R cos λ, y = R sin λ, z = z, α = R cos λ’, β = R sin λ’
and γ = z’.The mass element is Δρ dr dz rdλ , so that the gravity value of the axis z can be
written as:
(8)
The radial derivative of the gravity anomaly in vertical cylindrical coordinates Δgz (R, z,
λ) can simply be written as:
(9)
Figure 2 shows the field diagram used to calculate the radial derivative. ABCD, EFGH is
a cube with length of ribs along AB which is also the same as AJ. Points A, B, C and D are point
2 of measurement gravitation. A to B is the line towards the x-axis while A to D is towards the
y-axis. If the difference in gravity at point B with A is dx whose vector length is proportional to
BR, whereas the difference in the value of gravity of point A with D is the length of its vector
along the DS, then the APNQ is a plane with the same gravity value. If dT is the directional
value of the derivative then:
(a) (b)
Figure 2. (a) Plane diagram of radial derivative approach
(b) Radial inversion lines consist of 8 lines to make a radial inversion model
dT = JN= IP +KQ; (10)
with dT having a vector length equal to JN whose value is equal to the value of IP and KQ.It was
easy to understand, the total derivatif become:
dT = dx cos θ + dy sin θ (11)
0 2
3
222
,,
),,(
ddd
zyx
z
Kzyxgz
0
2
0 2
3
222
'',','
),,(
rdrdzd
zyx
zzzR
KzRgz
0
2
0 2
3
222
'',','
rdrdzd
zyx
zzzR
K
R
FRD
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2.3. Radial Inversion
The 4D gravity anomaly of the reservoir contaminated with shallow effect anomaly is
then separated by filtering. The residual (local effect) of the filtering is an undesirable shallow
anomaly, while the regional one is the anomaly part of the reservoir which is then be inverted by
inversion program. Figure 2 (b) shows some 2D inversion lines that produce a radial inversion.
The radial inversion performed in this case is assumed to be an anomaly derived only from the
reservoir. This inversion is based on the inversion of a cylindrical-like reservoir shape with
thickness corresponding to the reservoir thickness. The inversion result is expected to illustrate
the actual reservoir geometry shape, which includes density contrast and the fluid movement
radius in the reservoir.
Inversion theory can be regarded as an art to obtain various physical parameters with
sufficient knowledge about forward modeling [26]. Relation of observed data and model can be
written as:
d = g (m) (12)
where d is the observed data, m is the model parameter and g is forward function which is the
prediction function of the model known as Kernel function. If the observed data are N and the
model parameter of M can be related to the Kernel’s matrix by the (13):
d = G m (13)
where d is a Nx1 matrix, G is a NxM Kernel matrix and m is a model parameter of Mx1 size. The
inversion relationship of model parameters with observed data can be written as:
m = [G
T
G]
-l
G
T
d (14)
The measured gravity value actually has a non-linear relationship to the parameters of
the model in search of density contrast, radii and position, but this relationship can be solved by
linear approximation. The principle of this method is the LSQR with special development. The
formulation of non-linear inversion method with approach linear principle using the first Taylor
series and ignoring the higher rates of the Taylor series around x + Δx as follows:
f(x+∆x) = f(x)+f’(x) ∆x (15)
where f(x+∆x) is the measurement data written with d, f(x) is the result of the model response ie.
g(m0) and f’(x) is first derivative of the model parameter forming the Jacobi matrix J0, so:
d = g(m0) + J0Δm0 (16)
The Jacob's matrix consists of:
𝐽 𝐴 = [
𝜕𝑔 𝑖
𝜕𝑚 𝐴
] , 𝐽 𝑑 = [
𝜕𝑔 𝑖
𝜕𝑚 𝑑
] and 𝐽𝑟 = [
𝜕𝑔 𝑖
𝜕𝑚 𝑟
]
where A is the Amplitude factor d is the depth and r is the radius of the fluid injection front, so
the Jacobi matrix of the cylinder model can be written as:
J0 = [ JA Jd Jr ]
The Kernel model of this radial derivative function is based on Finite horizontal slab
wich can be written as:
𝑔 = 2𝐺𝜌𝑡 {𝜋 + 𝑡𝑎𝑛−1
(
𝑥+0.5𝐿
𝑧
) + 𝑡𝑎𝑛−1
(
0.5𝐿−𝑥
𝑧
)} (17)
from (16), we can obtain:
d - g(m0) = J0Δm (18)
so,
Δm = [J0
T
J0]
-1
J0
T
(d - g(m0)) (19)
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with Jo
T
is the transpose of matrix J0, since
d - g(m0) = Δd (20)
then Δd has a linear relationship with Δm so that it can be solved by LSQR method.
The principle of linear inversion solution is a recurring count that will yield the value
m=m0+Δm so that the minimum Δd value is obtained. With the RMS value of Δd small enough
to some extent, iteration is then stopped. With the very small value of Δd then the value of m
m0 so that the model parameters very close to the real value [26]. The flowchart of the process
is shown in Figure 3.
Figure 3. Flow chart in the radial inversion programming
3. Results and Analysis
3.1. Radial Derivatives for Injection Fluid Identification
An anomaly due to injection that has been removed from shallow effect is then treated
with radial derivative. This treatment is intended to find the front of fluid injection. The front of
fluid injection made a density contrast wich result measurable anomaly of gravity on the surface.
Figure 4 shows the radial derivative of 4D gravity anomaly due to injection from January to May.
The middle of the blue zone on the image can be interpreted as the contact boundary between
the injection fluid and the previous pore fluid. The yield show maximum radial derivative in the
area is 0,012 mGal/meter and the minimum value of 0 micro Gal/m.
(a) (b)
Figure 4. Radial derivative of 4D gravity anomaly due to injection:
(a) January to May period, (b) January to September period
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3.2. Radial Inversion For identification of Injection Fluid
The input of this Radial Inversion program is a file of 4D gravity anomaly containing
position (x, y) and gravity values in regular grid. The data is then extracted by the number of
specific lines to get the inversion lines. Each inversion line is then performed inversion process
with kernel function as finite horizontal slab (17). The yields of the inversion parameter are the
amplitude factor and the radius of fluid injection front. The result of this inversion data is then
unified and re-gridded to obtain 3-dimensional model of reservoir injection fluid.
Figure 5 shows the fluid injection volume model in the reservoir based on the radial
inversion method. The flat blue zone is interpreted as uncontaminated reservoir and the red
zone is volume of the injection fluid infiltrated the reservoir. The volume of the injection fluid has
a shape tends to be straight to the radii because the kernel matrix of the program only allows us
to obtain a uniform volumes thickness value toward the radius. Reservoir model due to fluid
injection as a result of radial inversion has maximum value of 1120 meter and minimum value of
304 meter.
(a)
(b)
Figure 5. Injection fluid volume model on the reservoir based on radial inversion results:
(a) January to May period, (b) January to September period
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4. Conclusion
Radial derivatives and Radial Inversion has been proven fairly good for identification of
fluid injection in the reservoir. This method is useful to help more accurate analysis of 4D gravity
around the reservoir. Radial derivatives are not only applicable to 4D anomalies due to fluid
injection in the reservoir, but also effective for the analysis of ordinary gravity anomalies with
horizontal slab shape. Radial Derivative Methods can also be applied to ordinary gravity
anomalies and become tools for further interpretation of existing gravity data.
Radial inversions can be applied to time lapse gravity data around injection wells for
identification of additional mass (positive density contrast) or mass reduction (negative density
contrast). Radial inversion can also be used in an ordinary gravity anomaly (3D) to detect
boundary of horizontal slab. Radial Inversion is fairly good to provide a physical reservoir
parameters. This program is useful for general interpretation of gravity and can be a reliable
additional software as a new way of interpretation.
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