The present paper is aimed at to study the reflection and transmission characteristics of plane waves at liquid-solid interface. The liquid is chosen to be inviscid and the solid
half-space is homogeneous isotropic, thermally conducting viscoelastic. Both classical (coupled) and non-classical (generalized) theories of linear thermo-viscoelasticity have been employed to investigate the characteristics of reflected and transmitted waves. Reflection and transmission coefficients are obtained for quasi-longitudinal ( qP ) wave. The numerical computations of reflection and transmission coefficients are carried out for water-copper structure with the help of Gauss-elimination by using MATLAB software and the results have been presented graphically.
Conformal Field Theory and the Holographic S-Matrixliam613
This document discusses how conformal field theories (CFTs) can describe gravitational scattering and provide an effective field theory (EFT) description of gravity in anti-de Sitter space (AdS). It introduces CFTs and issues with describing gravity at high energies. It then explains how the holographic duality between CFTs and gravity theories can be used to calculate scattering matrices and understand gravitational dynamics. In particular, it outlines how calculations in Mellin space allow CFT correlation functions to describe scattering in AdS space. The document also discusses when and why CFTs exhibit an EFT structure in AdS based on the structure of EFTs with a mass gap between light and heavy states.
Feedback of zonal flows on Rossby-wave turbulence driven by small scale inst...Colm Connaughton
The document summarizes research on the interaction between large-scale zonal flows and small-scale Rossby wave turbulence. It describes how modulational instability can generate large-scale zonal jets from small-scale Rossby waves through an inverse cascade. The generated jets then provide negative feedback on the small-scale waves by distorting them and inducing spectral diffusion through a nonlocal turbulence theory. Numerical simulations demonstrate this generation of jets and spectral transport between scales.
Large scale coherent structures and turbulence in quasi-2D hydrodynamic modelsColm Connaughton
This document discusses turbulence in two-dimensional systems and the inverse energy cascade phenomenon. It begins with an overview of turbulence in 3D and 2D, describing the inverse energy cascade in 2D systems whereby energy is transferred to larger scales rather than smaller scales. It then discusses how finite size effects can generate large-scale coherent structures by blocking the inverse cascade. The document concludes by noting that extracting coherent flow from turbulent fluctuations is challenging and that diagnostics like the third-order structure function may not be reliable indicators of the energy cascade direction due to the presence of coherent structures.
Nonequilibrium statistical mechanics of cluster-cluster aggregation, School o...Colm Connaughton
Colm Connaughton presented on nonequilibrium statistical mechanics models of cluster-cluster aggregation. He discussed simple models where particles move randomly and merge upon contact. More sophisticated models track the size distribution of clusters as they aggregate. The Smoluchowski equation describes this process. For certain collision kernels, clusters of arbitrarily large size can form in finite time, known as gelation. While some kernels mathematically describe instantaneous gelation, physical models avoid this with a cluster size cutoff. Stationary states can be reached with a particle source.
This document provides an introduction to the concept of wave turbulence. It discusses how waves interact nonlinearly at finite amplitudes to produce a statistical, non-equilibrium dynamics. Key points:
- Wave turbulence involves dispersive waves that are excited and damped by external processes, leading to interactions between many degrees of freedom.
- The nonlinear interactions can be modeled using a Hamiltonian approach by including higher-order terms that couple different Fourier modes.
- A central goal is developing a statistical description of the system using correlation functions and obtaining a closed kinetic equation for the wave spectrum.
- In the weak turbulence regime, this kinetic equation can be solved perturbatively to obtain scaling laws for the wave spectrum in both physical and
The document discusses phase transitions and the renormalization group transformation. It introduces the Ising model and defines the partition function and critical exponents to characterize phase transitions. It then provides a brief introduction to renormalization group transformations, defining the coarse graining, rescaling, and renormalizing steps. The renormalization group transformation maps the Hamiltonian at cutoff scale Λ to an effective Hamiltonian at a lower cutoff scale bΛ.
Conformal Field Theory and the Holographic S-Matrixliam613
This document discusses how conformal field theories (CFTs) can describe gravitational scattering and provide an effective field theory (EFT) description of gravity in anti-de Sitter space (AdS). It introduces CFTs and issues with describing gravity at high energies. It then explains how the holographic duality between CFTs and gravity theories can be used to calculate scattering matrices and understand gravitational dynamics. In particular, it outlines how calculations in Mellin space allow CFT correlation functions to describe scattering in AdS space. The document also discusses when and why CFTs exhibit an EFT structure in AdS based on the structure of EFTs with a mass gap between light and heavy states.
Feedback of zonal flows on Rossby-wave turbulence driven by small scale inst...Colm Connaughton
The document summarizes research on the interaction between large-scale zonal flows and small-scale Rossby wave turbulence. It describes how modulational instability can generate large-scale zonal jets from small-scale Rossby waves through an inverse cascade. The generated jets then provide negative feedback on the small-scale waves by distorting them and inducing spectral diffusion through a nonlocal turbulence theory. Numerical simulations demonstrate this generation of jets and spectral transport between scales.
Large scale coherent structures and turbulence in quasi-2D hydrodynamic modelsColm Connaughton
This document discusses turbulence in two-dimensional systems and the inverse energy cascade phenomenon. It begins with an overview of turbulence in 3D and 2D, describing the inverse energy cascade in 2D systems whereby energy is transferred to larger scales rather than smaller scales. It then discusses how finite size effects can generate large-scale coherent structures by blocking the inverse cascade. The document concludes by noting that extracting coherent flow from turbulent fluctuations is challenging and that diagnostics like the third-order structure function may not be reliable indicators of the energy cascade direction due to the presence of coherent structures.
Nonequilibrium statistical mechanics of cluster-cluster aggregation, School o...Colm Connaughton
Colm Connaughton presented on nonequilibrium statistical mechanics models of cluster-cluster aggregation. He discussed simple models where particles move randomly and merge upon contact. More sophisticated models track the size distribution of clusters as they aggregate. The Smoluchowski equation describes this process. For certain collision kernels, clusters of arbitrarily large size can form in finite time, known as gelation. While some kernels mathematically describe instantaneous gelation, physical models avoid this with a cluster size cutoff. Stationary states can be reached with a particle source.
This document provides an introduction to the concept of wave turbulence. It discusses how waves interact nonlinearly at finite amplitudes to produce a statistical, non-equilibrium dynamics. Key points:
- Wave turbulence involves dispersive waves that are excited and damped by external processes, leading to interactions between many degrees of freedom.
- The nonlinear interactions can be modeled using a Hamiltonian approach by including higher-order terms that couple different Fourier modes.
- A central goal is developing a statistical description of the system using correlation functions and obtaining a closed kinetic equation for the wave spectrum.
- In the weak turbulence regime, this kinetic equation can be solved perturbatively to obtain scaling laws for the wave spectrum in both physical and
The document discusses phase transitions and the renormalization group transformation. It introduces the Ising model and defines the partition function and critical exponents to characterize phase transitions. It then provides a brief introduction to renormalization group transformations, defining the coarse graining, rescaling, and renormalizing steps. The renormalization group transformation maps the Hamiltonian at cutoff scale Λ to an effective Hamiltonian at a lower cutoff scale bΛ.
1. The document discusses nonadiabatic transitions in chemical systems using path integral representations.
2. It introduces a nonadiabatic path integral approach based on overlap integrals between nuclear configurations on different electronic surfaces, as an alternative to the traditional derivative coupling approach.
3. A nonadiabatic beads model is presented for calculating nonadiabatic partition functions using a quantum-classical mapping, where the Boltzmann operator is divided among discrete nuclear coordinates on different surfaces connected by overlap integrals.
Resolving the dissociation catastrophe in fluctuating-charge modelsJiahao Chen
The document discusses issues that arise when using fluctuating charge models to describe chemical systems. It summarizes the concept of fluctuating charges based on electronegativity equalization. However, this leads to an unphysical "dissociation catastrophe" where charges do not decay to zero at infinite separation. The document proposes fixing this by introducing distance-dependent electronegativity or charge transfer variables between atoms to attenuate long-range charge transfer. It also discusses the topological relationship between charge transfer variables and atomic charges to convert between representations.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses partial differential equations (PDEs) governing fluid flow. It presents the Navier-Stokes equations and Euler equations which describe the conservation of mass, momentum, and energy in fluid flow. It also discusses the mathematical behavior of PDEs in terms of elliptic, parabolic and hyperbolic equations. Shock capturing and shock fitting methods for solving PDEs with shock waves are introduced. Boundary conditions such as Dirichlet, Neumann and initial conditions are also covered.
The document discusses developing a wireless sensor network system for structural health monitoring using non-destructive evaluation techniques like acoustic emission testing and ultrasound testing. It outlines objectives like sensor node development, network control, and damage detection algorithms. The project status updates sensor node development and a finite element model for lamb wave propagation. Future plans include more signal processing algorithms and investigating additional non-destructive methods.
Instantaneous Gelation in Smoluchwski's Coagulation Equation Revisited, Confe...Colm Connaughton
Invited talk given at "Boltzmann equation:
mathematics, modeling and simulations
In memory of Carlo Cercignani", Institut Henri Poincare, Paris, February 11, 2011.
Talk given at the workshop "Multiphase turbulent flows in the atmosphere and ocean", National Centre for Atmospheric REsearch, Boulder CO, August 15 2012
This document is the front cover of a physics exam from the University of Cambridge International Examinations. It provides instructions for a multiple choice exam with 40 questions on physics. The exam covers topics such as mechanics, materials, waves, electricity, quantum and nuclear physics, thermodynamics, and astronomy. Candidates are instructed to choose the correct answer for each question and record their choice on an answer sheet provided. They are given 1 hour to complete the exam.
The document discusses electronic excited states and challenges in simulating their dynamics. It describes how excited states are described using different representations like adiabatic and diabatic. It highlights how conical intersections are better described than avoided crossings and how nonadiabatic transitions occur. It also summarizes challenges with excited state electronic structure methods like TDDFT in accurately describing conical intersections.
Conformal Anisotropic Mechanics And The HořAva Dispersion Relationvcuesta
This document summarizes a paper that implements scale anisotropic transformations between space and time in classical mechanics. This results in a system consistent with the dispersion relation proposed in Horava gravity. The paper constructs an action principle for a particle that is invariant under anisotropic scaling transformations between space and time. This action reduces to known systems like conformal mechanics in certain limits of the dynamical exponent z. The paper also analyzes the canonical formalism, equations of motion, symmetries and thermodynamic properties of this anisotropic mechanical system.
Okay, let's break this down step-by-step:
* River flows southeast at 10 km/hr
* Let's define southeast as 45° from the east
* So the river's velocity is 10 cos(45°)ax + 10 sin(45°)ay = 7.07ax + 7.07ay
* Boat moves in the direction of the river at vB
* Man walks on deck at 2 km/hr perpendicular to the boat
* So the man's velocity is 2ay
* To find the total velocity, we add the velocities:
Total velocity = River velocity + Boat velocity + Man's velocity
= 7.07ax + 7.07ay + vB + 2
This document discusses the challenges of describing the structure of the proton using quantum chromodynamics (QCD). While QCD was developed in the 1970s, scientists are still unable to fully describe the fundamental state of the proton using non-perturbative QCD at large distances. At small distances, perturbative QCD is calculable due to asymptotic freedom. Parton distribution functions provide information about how quarks and gluons are distributed within the proton, but only describe one-dimensional motion and do not account for all of the proton's spin. New experiments aim to better understand proton structure through measurements of transverse momentum-dependent parton distributions.
(1) Biot-Savart's law states that the magnetic field intensity produced at a point P by a differential current element is proportional to the product of the current and the sine of the angle between the element and the line joining P to the element, and inversely proportional to the square of the distance between P and the element.
(2) The magnetic field intensity due to different current distributions such as line, surface, and volume currents can be determined using Biot-Savart's law.
(3) Example problems demonstrate applying Biot-Savart's law to calculate the magnetic field intensity at a point due to straight and semi-infinite current filaments.
The Inverse Smoluchowski Problem, Particles In Turbulence 2011, Potsdam, Marc...Colm Connaughton
This document summarizes Colm Connaughton's presentation on solving the inverse Smoluchowski problem to determine particle collision kernels from observed cluster size distributions. It describes how the forward problem maps kernels to distributions but the inverse problem is ill-posed. Tikhonov regularization is used to obtain approximate kernel reconstructions from numerical solutions with known test kernels, demonstrating partial success in reconstructing kernel features despite ill-posedness. Future work aims to address limitations and applicability to real problems.
This document reviews research on the convergence of perturbation series in quantum field theory. It discusses Dyson's argument that perturbation series in quantum electrodynamics (QED) have zero radius of convergence due to vacuum instability when the coupling constant is negative. Large-order estimates show that perturbation series coefficients grow factorially fast in quantum mechanics and field theories. Finally, it describes the method of Borel summation, which may allow extracting the exact physical quantity from a divergent perturbation series through a unique mapping.
This document summarizes a talk on the variation of fundamental constants over time. It discusses several methods for measuring potential variations, including analyses of the cosmic microwave background, quasar absorption spectra, radioactive decay rates from the natural nuclear reactor at Oklo, and comparisons of atomic clock rates. Measurements from big bang nucleosynthesis and quasar data suggest the fine structure constant may have been smaller in the early universe, varying on the order of 10^-15 per year. However, results are not conclusive and depend on theoretical models. Ongoing work using improved atomic clocks aims to more precisely measure any drift of fundamental constants like the fine structure constant and quark-mass ratios over time.
Circular Waves in Thermoelastic Plates Bordered with Viscous Liquid IDES Editor
The paper concentrates on the study of propagation of thermoelastic waves in a homogeneous, transversely isotropic, thermally conducting elastic plate bordered with layers (or half-spaces) of viscous liquid on both sides in the
context of non classical theories of thermoelasticity. Complex secular equations for symmetric and antisymmetric wave motion of the circular plate, in completely separate terms, are derived. Finally, in order to illustrate the analytical results, the numerical solution is carried out for transversely isotropic plate of cobalt material bordered with water by using the functional iteration method.
Thermoelastic Damping of Vibrations in a Transversely Isotropic Hollow Cylinder IDES Editor
The purpose of the paper is to analyze the damping of three-dimensional free vibrations in a transversely isotropic, thermoelastic hollow cylinder, which is initially undeformed
and kept at uniform temperature. The surfaces of the cylinder are subjected to stress free and thermally insulated boundary conditions. The displacement potential functions have been introduced for decoupling the purely shear and longitudinal motions in the equations of motion and heat equation. The purely transverse wave gets decoupled from rest of the motion and is not affected by thermal field. By using the method of separation of variables, the system of governing partial differential equations is reduced to four second order coupled ordinary differential equation in radial coordinate. The matrix Frobenius method of extended power series is employed to obtain the solution of coupled ordinary differential equations along the radial coordinate. In order to illustrate the analytic results, the numerical solution of various relations and equations are carried out to compute lowest frequency and thermoelastic damping factor with M ATLAB software programming for zinc material. The computer simulated results have been presented graphically.
1. The document discusses nonadiabatic transitions in chemical systems using path integral representations.
2. It introduces a nonadiabatic path integral approach based on overlap integrals between nuclear configurations on different electronic surfaces, as an alternative to the traditional derivative coupling approach.
3. A nonadiabatic beads model is presented for calculating nonadiabatic partition functions using a quantum-classical mapping, where the Boltzmann operator is divided among discrete nuclear coordinates on different surfaces connected by overlap integrals.
Resolving the dissociation catastrophe in fluctuating-charge modelsJiahao Chen
The document discusses issues that arise when using fluctuating charge models to describe chemical systems. It summarizes the concept of fluctuating charges based on electronegativity equalization. However, this leads to an unphysical "dissociation catastrophe" where charges do not decay to zero at infinite separation. The document proposes fixing this by introducing distance-dependent electronegativity or charge transfer variables between atoms to attenuate long-range charge transfer. It also discusses the topological relationship between charge transfer variables and atomic charges to convert between representations.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses partial differential equations (PDEs) governing fluid flow. It presents the Navier-Stokes equations and Euler equations which describe the conservation of mass, momentum, and energy in fluid flow. It also discusses the mathematical behavior of PDEs in terms of elliptic, parabolic and hyperbolic equations. Shock capturing and shock fitting methods for solving PDEs with shock waves are introduced. Boundary conditions such as Dirichlet, Neumann and initial conditions are also covered.
The document discusses developing a wireless sensor network system for structural health monitoring using non-destructive evaluation techniques like acoustic emission testing and ultrasound testing. It outlines objectives like sensor node development, network control, and damage detection algorithms. The project status updates sensor node development and a finite element model for lamb wave propagation. Future plans include more signal processing algorithms and investigating additional non-destructive methods.
Instantaneous Gelation in Smoluchwski's Coagulation Equation Revisited, Confe...Colm Connaughton
Invited talk given at "Boltzmann equation:
mathematics, modeling and simulations
In memory of Carlo Cercignani", Institut Henri Poincare, Paris, February 11, 2011.
Talk given at the workshop "Multiphase turbulent flows in the atmosphere and ocean", National Centre for Atmospheric REsearch, Boulder CO, August 15 2012
This document is the front cover of a physics exam from the University of Cambridge International Examinations. It provides instructions for a multiple choice exam with 40 questions on physics. The exam covers topics such as mechanics, materials, waves, electricity, quantum and nuclear physics, thermodynamics, and astronomy. Candidates are instructed to choose the correct answer for each question and record their choice on an answer sheet provided. They are given 1 hour to complete the exam.
The document discusses electronic excited states and challenges in simulating their dynamics. It describes how excited states are described using different representations like adiabatic and diabatic. It highlights how conical intersections are better described than avoided crossings and how nonadiabatic transitions occur. It also summarizes challenges with excited state electronic structure methods like TDDFT in accurately describing conical intersections.
Conformal Anisotropic Mechanics And The HořAva Dispersion Relationvcuesta
This document summarizes a paper that implements scale anisotropic transformations between space and time in classical mechanics. This results in a system consistent with the dispersion relation proposed in Horava gravity. The paper constructs an action principle for a particle that is invariant under anisotropic scaling transformations between space and time. This action reduces to known systems like conformal mechanics in certain limits of the dynamical exponent z. The paper also analyzes the canonical formalism, equations of motion, symmetries and thermodynamic properties of this anisotropic mechanical system.
Okay, let's break this down step-by-step:
* River flows southeast at 10 km/hr
* Let's define southeast as 45° from the east
* So the river's velocity is 10 cos(45°)ax + 10 sin(45°)ay = 7.07ax + 7.07ay
* Boat moves in the direction of the river at vB
* Man walks on deck at 2 km/hr perpendicular to the boat
* So the man's velocity is 2ay
* To find the total velocity, we add the velocities:
Total velocity = River velocity + Boat velocity + Man's velocity
= 7.07ax + 7.07ay + vB + 2
This document discusses the challenges of describing the structure of the proton using quantum chromodynamics (QCD). While QCD was developed in the 1970s, scientists are still unable to fully describe the fundamental state of the proton using non-perturbative QCD at large distances. At small distances, perturbative QCD is calculable due to asymptotic freedom. Parton distribution functions provide information about how quarks and gluons are distributed within the proton, but only describe one-dimensional motion and do not account for all of the proton's spin. New experiments aim to better understand proton structure through measurements of transverse momentum-dependent parton distributions.
(1) Biot-Savart's law states that the magnetic field intensity produced at a point P by a differential current element is proportional to the product of the current and the sine of the angle between the element and the line joining P to the element, and inversely proportional to the square of the distance between P and the element.
(2) The magnetic field intensity due to different current distributions such as line, surface, and volume currents can be determined using Biot-Savart's law.
(3) Example problems demonstrate applying Biot-Savart's law to calculate the magnetic field intensity at a point due to straight and semi-infinite current filaments.
The Inverse Smoluchowski Problem, Particles In Turbulence 2011, Potsdam, Marc...Colm Connaughton
This document summarizes Colm Connaughton's presentation on solving the inverse Smoluchowski problem to determine particle collision kernels from observed cluster size distributions. It describes how the forward problem maps kernels to distributions but the inverse problem is ill-posed. Tikhonov regularization is used to obtain approximate kernel reconstructions from numerical solutions with known test kernels, demonstrating partial success in reconstructing kernel features despite ill-posedness. Future work aims to address limitations and applicability to real problems.
This document reviews research on the convergence of perturbation series in quantum field theory. It discusses Dyson's argument that perturbation series in quantum electrodynamics (QED) have zero radius of convergence due to vacuum instability when the coupling constant is negative. Large-order estimates show that perturbation series coefficients grow factorially fast in quantum mechanics and field theories. Finally, it describes the method of Borel summation, which may allow extracting the exact physical quantity from a divergent perturbation series through a unique mapping.
This document summarizes a talk on the variation of fundamental constants over time. It discusses several methods for measuring potential variations, including analyses of the cosmic microwave background, quasar absorption spectra, radioactive decay rates from the natural nuclear reactor at Oklo, and comparisons of atomic clock rates. Measurements from big bang nucleosynthesis and quasar data suggest the fine structure constant may have been smaller in the early universe, varying on the order of 10^-15 per year. However, results are not conclusive and depend on theoretical models. Ongoing work using improved atomic clocks aims to more precisely measure any drift of fundamental constants like the fine structure constant and quark-mass ratios over time.
Circular Waves in Thermoelastic Plates Bordered with Viscous Liquid IDES Editor
The paper concentrates on the study of propagation of thermoelastic waves in a homogeneous, transversely isotropic, thermally conducting elastic plate bordered with layers (or half-spaces) of viscous liquid on both sides in the
context of non classical theories of thermoelasticity. Complex secular equations for symmetric and antisymmetric wave motion of the circular plate, in completely separate terms, are derived. Finally, in order to illustrate the analytical results, the numerical solution is carried out for transversely isotropic plate of cobalt material bordered with water by using the functional iteration method.
Thermoelastic Damping of Vibrations in a Transversely Isotropic Hollow Cylinder IDES Editor
The purpose of the paper is to analyze the damping of three-dimensional free vibrations in a transversely isotropic, thermoelastic hollow cylinder, which is initially undeformed
and kept at uniform temperature. The surfaces of the cylinder are subjected to stress free and thermally insulated boundary conditions. The displacement potential functions have been introduced for decoupling the purely shear and longitudinal motions in the equations of motion and heat equation. The purely transverse wave gets decoupled from rest of the motion and is not affected by thermal field. By using the method of separation of variables, the system of governing partial differential equations is reduced to four second order coupled ordinary differential equation in radial coordinate. The matrix Frobenius method of extended power series is employed to obtain the solution of coupled ordinary differential equations along the radial coordinate. In order to illustrate the analytic results, the numerical solution of various relations and equations are carried out to compute lowest frequency and thermoelastic damping factor with M ATLAB software programming for zinc material. The computer simulated results have been presented graphically.
This document presents a mathematical analysis of the unsteady free convection and mass transfer flow through a porous medium with variable viscosity and thermal conductivity. The governing equations for momentum, temperature, and concentration are non-dimensionalized and solved using an explicit finite difference method. Key aspects include:
1) The flow is induced by an exponentially accelerated vertical plate with variable temperature and concentration.
2) Viscosity and thermal conductivity are assumed to vary linearly with temperature.
3) The resulting non-dimensional equations are nonlinear partial differential equations solved numerically.
4) Skin friction and Nusselt numbers are defined and analyzed graphically.
Boundary Layer Flow in the Vicinity of the Forward Stagnation Point of the Sp...iosrjce
Exact solutions are important not only in its own right as solution of particular flows, but also serve as accuracy check for numerical solution. Exact solution of the Navier-Strokes equation are, for example, those
of steady and unsteady flows near a stagnation point, Stagnation point flows can either be viscous or inviscid,
steady or unsteady, two dimensional or three dimensional, normal or oblique and forward or reverse. The classic problems of two dimensional and three dimensional stagnation point flow are associated with the names of Hiemenz and Homan A novel radial stagnation point flow impinging axi symmetrically on a circular cylinder was reported by Wang. The present paper deals with the laminar boundary layer flow and heat transfer in the
stagnation region of a rotating and translating sphere with uniform magnetic fields. The governing equations of
flow are derived for ξ = 0 (t*=0) and ξ=1 (t*→∞) and solutions in the closed form are obtained. The
temperature and velocity fields for ξ = 0 are numerically computed. This shows that the thermal boundary layer
thickness decreases as Prandtl number Princreases.The surface heat transfer (28) increases with the Prandtl
number Pr. The surface heat transfer (28) at the starting of motion is found to be strangely dependent on the
Prandtl number Pr. But it is dependent of magnetic field, buoyancy force Bp and Rotation Parameter Ro.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Nonlinear Asymmetric Kelvin-Helmholtz Instability Of Cylindrical Flow With Ma...ijtsrd
The nonlinear asymmetric Kelvin-Helmholtz stability of the cylindrical interface between the vapor and liquid phases of a °uid is studied when the phases are enclosed between two cylindri- cal surfaces coaxial with the interface, and when there is mass and heat transfer across the inter- face. The method of multiple time expansion is used for the investigation. The evolution of am- plitude is shown to be governed by a nonlinear ¯rst order di®erential equation. The stability cri- terion is discussed, and the region of stability is displayed graphically. Also investigated in this paper is the viscous linear potential °ow. DOO-SUNG LEE"Nonlinear Asymmetric Kelvin-Helmholtz Instability Of Cylindrical Flow With Mass And Heat Transfer And The Viscous Linear Analysis" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd17030.pdf http://www.ijtsrd.com/mathemetics/applied-mathematics/17030/nonlinear-asymmetric-kelvin-helmholtz-instability-of-cylindrical-flow-with-mass-and-heat-transfer-and-the-viscous-linear-analysis/doo-sung-lee
1) This study numerically simulates the electro-deposition process using the Nernst-Planck equation to model ion transport due to diffusion, convection, and migration under an applied electric field.
2) The model is validated by comparing results for diffusion layer thickness and transient current density to existing analytical and experimental models.
3) Parameter studies show that convection increases deposition rate by decreasing the effective diffusion layer thickness, and that migration effects must be considered for accurate modeling of applied voltage, current density, and diffusion layer thickness relationships.
International Journal of Computational Engineering Research(IJCER)ijceronline
The document summarizes a study on the effect of thermal radiation on boundary layer flow of a second-grade fluid over a stretching sheet through a porous medium, where the fluid's viscosity and thermal conductivity are temperature dependent. The governing equations are non-dimensionalized using similarity transformations and then solved numerically. Results show the effects of various parameters like radiation, viscosity, thermal conductivity, and porosity on the fluid's velocity and temperature profiles, as well as the skin friction coefficient and Nusselt number.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
This document discusses a numerical study of the effect of thermal radiation on free convection boundary layer flow over a vertical wavy cone. The governing equations for steady, laminar, two-dimensional flow are presented and non-dimensionalized. These equations are then solved using the Mathematica technique. Graphs of the dimensionless temperature, velocity, skin friction coefficient, and Nusselt number are generated for various values of the Prandtl number, radiation parameter, surface wave amplitude, and cone half-angle. The results are discussed to analyze the impact of thermal radiation on the flow and heat transfer characteristics.
Effects of some thermo physical properties on forceAlexander Decker
This document presents research on force convective stagnation point flow over a stretching sheet with convective boundary conditions in the presence of thermal radiation and a magnetic field. Governing equations for the flow are derived and non-dimensionalized. The equations are then solved numerically using a shooting method. Results show that increasing the magnetic field parameter decreases velocity, while increasing the Biot number increases temperature. Temperature is also found to decrease with increasing Eckert number, Prandtl number, and radiation parameter. Skin friction coefficient and local Nusselt number are presented for various parameter values.
This document presents a numerical study examining heat and mass transfer in a porous medium past an infinite inclined vertical plate with consideration of Soret and Dufour effects and chemical reaction. The governing equations for momentum, energy, and concentration are non-dimensionalized and solved using an implicit finite difference method. Results show the velocity, temperature, and concentration profiles are influenced by parameters like inclination angle, permeability, Dufour number, Prandtl number, Grashof number, and chemical reaction parameter. Graphs illustrate the impact of varying these parameters on the fluid flow, thermal, and concentration fields.
Chemical Reaction on Heat and Mass TransferFlow through an Infinite Inclined ...iosrjce
The numerical studies are performed to examine the mass transfer flow with thermal diffusion and
diffusion thermo effect past an infinite, inclined vertical plate in a porous medium in the presence of chemical
reaction. First of all, the governing equations are transformed to a system of dimensionless coupled partial
equations. Explicit finite difference method has been used to solve these dimensionless equations for momentum,
concentration and energy equations. During the course of discussion, it is found that various parameters related
to the problem influence the calculated result. Finally, the profiles of velocity, concentration and temperature
are analyzed and illustrated with graphs.
This document discusses a numerical study examining heat and mass transfer in a porous medium past an infinite inclined vertical plate with consideration of Soret and Dufour effects and chemical reaction. The governing equations for momentum, energy, and concentration are transformed into dimensionless form and solved using an implicit finite difference method. The results show the velocity, temperature, and concentration profiles are influenced by parameters like inclination angle, permeability, Dufour number, Prandtl number, Grashof number, and chemical reaction parameter. Graphs illustrate the impact of varying these parameters on the fluid flow, thermal, and concentration fields.
This document summarizes a study that examines heat and mass transfer over a vertical plate in a porous medium with Soret and Dufour effects, a convective surface boundary condition, chemical reaction, and magnetic field. The governing equations for the fluid flow, heat transfer, and mass transfer are presented. Similarity solutions are used to transform the governing partial differential equations into ordinary differential equations, which are then solved numerically. The results are presented graphically to show the influence of various parameters on velocity, temperature, concentration, skin friction, Nusselt number, and Sherwood number.
This document presents a numerical solution for unsteady heat and mass transfer flow past an infinite vertical plate with variable thermal conductivity, taking into account Dufour number and heat source effects. The governing equations are non-linear and coupled, and were solved numerically using an implicit finite difference scheme. Various parameters, including Dufour number and heat source, were found to influence the velocity, temperature, and concentration profiles. Skin friction, Nusselt number, and Sherwood number were also calculated.
Ultracold atoms in superlattices as quantum simulators for a spin ordering mo...Alexander Decker
This document discusses using ultracold fermionic atoms in optical lattices to simulate spin ordering models. It begins by describing how atoms can be trapped in optical lattices using laser light. It then proposes how a spin ordering Hamiltonian could be used to achieve superexchange interaction in a double well system. Finally, it suggests going beyond double wells to study resonating valence bond states in a kagome lattice, which could provide insights into phenomena like high-temperature superconductivity.
Nanofluid Flow past an Unsteady Permeable Shrinking Sheet with Heat Source or...IJERA Editor
The consideration of nanofluids has been paid a good attention on the forced convection; the analysis focusing
nanofluids in porous media are limited in literature. Thus, the use of nanofluids in porous media would be very
much helpful in heat and mass transfer enhancement. In this paper, the influence of variable suction, Newtonian
heating and heat source or sink heat and mass transfer over a permeable shrinking sheet embedded in a porous
medium filled with a nanofluid is discussed in detail. The solutions of the nonlinear equations governing the
velocɨty, temperature and concentration profiles are solved numerically using Runge-Kutta Gill procedure
together with shooting method and graphical results for the resulting parameters are displayed and discussed.
The influence of the physical parameters on skin-friction coefficient, local Nusselt number and local Sherwood
number are shown in a tabulated form.
Nanofluid Flow past an Unsteady Permeable Shrinking Sheet with Heat Source or...IJERA Editor
The consideration of nanofluids has been paid a good attention on the forced convection; the analysis focusing
nanofluids in porous media are limited in literature. Thus, the use of nanofluids in porous media would be very
much helpful in heat and mass transfer enhancement. In this paper, the influence of variable suction, Newtonian
heating and heat source or sink heat and mass transfer over a permeable shrinking sheet embedded in a porous
medium filled with a nanofluid is discussed in detail. The solutions of the nonlinear equations governing the
velocɨty, temperature and concentration profiles are solved numerically using Runge-Kutta Gill procedure
together with shooting method and graphical results for the resulting parameters are displayed and discussed.
The influence of the physical parameters on skin-friction coefficient, local Nusselt number and local Sherwood
number are shown in a tabulated form.
Nanofluid Flow past an Unsteady Permeable Shrinking Sheet with Heat Source or...IJERA Editor
The consideration of nanofluids has been paid a good attention on the forced convection; the analysis focusing
nanofluids in porous media are limited in literature. Thus, the use of nanofluids in porous media would be very
much helpful in heat and mass transfer enhancement. In this paper, the influence of variable suction, Newtonian
heating and heat source or sink heat and mass transfer over a permeable shrinking sheet embedded in a porous
medium filled with a nanofluid is discussed in detail. The solutions of the nonlinear equations governing the
velocɨty, temperature and concentration profiles are solved numerically using Runge-Kutta Gill procedure
together with shooting method and graphical results for the resulting parameters are displayed and discussed.
The influence of the physical parameters on skin-friction coefficient, local Nusselt number and local Sherwood
number are shown in a tabulated form.
Similar to Reflection and Transmission of Thermo-Viscoelastic Plane Waves at Liquid-Solid Interface (20)
Power System State Estimation - A ReviewIDES Editor
This document provides a review of power system state estimation techniques. It discusses both static and dynamic state estimation algorithms. For static state estimation, it covers weighted least squares, decoupled, and robust estimation methods. Weighted least squares is commonly used but can have numerical instability issues. Decoupled state estimation approximates the gain matrix for faster computation. Robust estimation uses M-estimators and other techniques to handle outliers and bad data. Dynamic state estimation applies Kalman filtering, leapfrog algorithms, and other methods to continuously monitor system states over time.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Study of Structural Behaviour of Gravity Dam with Various Features of Gallery...IDES Editor
The size and shape of opening in dam causes the
stress concentration, it also causes the stress variation in the
rest of the dam cross section. The gravity method of the analysis
does not consider the size of opening and the elastic property
of dam material. Thus the objective of study is comprises of
the Finite Element Method which considers the size of
opening, elastic property of material, and stress distribution
because of geometric discontinuity in cross section of dam.
Stress concentration inside the dam increases with the opening
in dam which results in the failure of dam. Hence it is
necessary to analyses large opening inside the dam. By making
the percentage area of opening constant and varying size and
shape of opening the analysis is carried out. For this purpose
a section of Koyna Dam is considered. Dam is defined as a
plane strain element in FEM, based on geometry and loading
condition. Thus this available information specified our path
of approach to carry out 2D plane strain analysis. The results
obtained are then compared mutually to get most efficient
way of providing large opening in the gravity dam.
Assessing Uncertainty of Pushover Analysis to Geometric ModelingIDES Editor
Pushover Analysis a popular tool for seismic
performance evaluation of existing and new structures and is
nonlinear Static procedure where in monotonically increasing
loads are applied to the structure till the structure is unable
to resist the further load .During the analysis, whatever the
strength of concrete and steel is adopted for analysis of
structure may not be the same when real structure is
constructed and the pushover analysis results are very sensitive
to material model adopted, geometric model adopted, location
of plastic hinges and in general to procedure followed by the
analyzer. In this paper attempt has been made to assess
uncertainty in pushover analysis results by considering user
defined hinges and frame modeled as bare frame and frame
with slab modeled as rigid diaphragm and results compared
with experimental observations. Uncertain parameters
considered includes the strength of concrete, strength of steel
and cover to the reinforcement which are randomly generated
and incorporated into the analysis. The results are then
compared with experimental observations.
Secure Multi-Party Negotiation: An Analysis for Electronic Payments in Mobile...IDES Editor
This document summarizes and analyzes secure multi-party negotiation protocols for electronic payments in mobile computing. It presents a framework for secure multi-party decision protocols using lightweight implementations. The main focus is on synchronizing security features to avoid agreement manipulation and reduce user traffic. The paper describes negotiation between an auctioneer and bidders, showing multiparty security is better than existing systems. It analyzes the performance of encryption algorithms like ECC, XTR, and RSA for use in the multiparty negotiation protocols.
Selfish Node Isolation & Incentivation using Progressive ThresholdsIDES Editor
The problems associated with selfish nodes in
MANET are addressed by a collaborative watchdog approach
which reduces the detection time for selfish nodes thereby
improves the performance and accuracy of watchdogs[1]. In
the related works they make use of credit based systems, reputation
based mechanisms, pathrater and watchdog mechanism
to detect such selfish nodes. In this paper we follow an approach
of collaborative watchdog which reduces the detection
time for selfish nodes and also involves the removal of such
selfish nodes based on some progressively assessed thresholds.
The threshold gives the nodes a chance to stop misbehaving
before it is permanently deleted from the network.
The node passes through several isolation processes before it
is permanently removed. Another version of AODV protocol
is used here which allows the simulation of selfish nodes in
NS2 by adding or modifying log files in the protocol.
Various OSI Layer Attacks and Countermeasure to Enhance the Performance of WS...IDES Editor
Wireless sensor networks are networks having non
wired infrastructure and dynamic topology. In OSI model each
layer is prone to various attacks, which halts the performance
of a network .In this paper several attacks on four layers of
OSI model are discussed and security mechanism is described
to prevent attack in network layer i.e wormhole attack. In
Wormhole attack two or more malicious nodes makes a covert
channel which attracts the traffic towards itself by depicting a
low latency link and then start dropping and replaying packets
in the multi-path route. This paper proposes promiscuous mode
method to detect and isolate the malicious node during
wormhole attack by using Ad-hoc on demand distance vector
routing protocol (AODV) with omnidirectional antenna. The
methodology implemented notifies that the nodes which are
not participating in multi-path routing generates an alarm
message during delay and then detects and isolate the
malicious node from network. We also notice that not only
the same kind of attacks but also the same kind of
countermeasures can appear in multiple layer. For example,
misbehavior detection techniques can be applied to almost all
the layers we discussed.
Responsive Parameter based an AntiWorm Approach to Prevent Wormhole Attack in...IDES Editor
The recent advancements in the wireless technology
and their wide-spread deployment have made remarkable
enhancements in efficiency in the corporate and industrial
and Military sectors The increasing popularity and usage of
wireless technology is creating a need for more secure wireless
Ad hoc networks. This paper aims researched and developed
a new protocol that prevents wormhole attacks on a ad hoc
network. A few existing protocols detect wormhole attacks but
they require highly specialized equipment not found on most
wireless devices. This paper aims to develop a defense against
wormhole attacks as an Anti-worm protocol which is based on
responsive parameters, that does not require as a significant
amount of specialized equipment, trick clock synchronization,
no GPS dependencies.
Cloud Security and Data Integrity with Client Accountability FrameworkIDES Editor
This document summarizes a proposed cloud security and data integrity framework that provides client accountability. The framework aims to address issues like lack of user control over cloud data, need for data transparency and tracking, and ensuring data integrity. It proposes using JAR (Java Archive) files for data sharing due to benefits like portability. The framework incorporates client-side verification using MD5 hashing, digital signature-based authentication of JAR files, and use of HMAC to ensure data integrity. It also uses password-based encryption of log files to keep them tamper-proof. The framework is intended to provide both accountability and security for data sharing in cloud environments.
Genetic Algorithm based Layered Detection and Defense of HTTP BotnetIDES Editor
A System state in HTTP botnet uses HTTP protocol
for the creation of chain of Botnets thereby compromising
other systems. By using HTTP protocol and port number 80,
attacks can not only be hidden but also pass through the
firewall without being detected. The DPR based detection
leads to better analysis of botnet attacks [3]. However, it
provides only probabilistic detection of the attacker and also
time consuming and error prone. This paper proposes a Genetic
algorithm based layered approach for detecting as well as
preventing botnet attacks. The paper reviews p2p firewall
implementation which forms the basis of filtering.
Performance evaluation is done based on precision, F-value
and probability. Layered approach reduces the computation
and overall time requirement [7]. Genetic algorithm promises
a low false positive rate.
Enhancing Data Storage Security in Cloud Computing Through SteganographyIDES Editor
This document summarizes a research paper that proposes a method for enhancing data security in cloud computing through steganography. The method hides user data in digital images stored on cloud servers. When data needs to be accessed, it is extracted from the images. The document outlines the cloud architecture and security issues addressed. It then describes the proposed system architecture, security model, and data storage and retrieval process. Data is partitioned and hidden in multiple images to improve security. The goal is to prevent unauthorized access to user data stored on cloud servers.
The main tasks of a Wireless Sensor Network
(WSN) are data collection from its nodes and communication
of this data to the base station (BS). The protocols used for
communication among the WSN nodes and between the WSN
and the BS, must consider the resource constraints of nodes,
battery energy, computational capabilities and memory. The
WSN applications involve unattended operation of the network
over an extended period of time. In order to extend the lifetime
of a WSN, efficient routing protocols need to be adopted. The
proposed low power routing protocol based on tree-based
network structure reliably forwards the measured data towards
the BS using TDMA. An energy consumption analysis of the
WSN making use of this protocol is also carried out. It is
found that the network is energy efficient with an average
duty cycle of 0:7% for the WSN nodes. The OmNET++
simulation platform along with MiXiM framework is made
use of.
Permutation of Pixels within the Shares of Visual Cryptography using KBRP for...IDES Editor
The security of authentication of internet based
co-banking services should not be susceptible to high risks.
The passwords are highly vulnerable to virus attacks due to
the lack of high end embedding of security methods. In order
for the passwords to be more secure, people are generally
compelled to select jumbled up character based passwords
which are not only less memorable but are also equally prone
to insecurity. Multiple use of distributed shares has been
studied to solve the problem of authentication by algorithms
based on thresholding of pixels in image processing and visual
cryptography concepts where the subset of shares is considered
for the recovery of the original image for authentication using
correlation function[1][2].The main disadvantage in the above
study is the plain storage of shares and also one of the shares
is being supplied to the customer, which will lead to the
possibility of misuse by a third party. This paper proposes a
technique for scrambling of pixels by key based random
permutation (KBRP) within the shares before the
authentication has been attempted. Total number of shares to
be created is dependent on the multiplicity of ownership of
the account. By this method the problem of uncertainty among
the customers with regard to security, storage, retrieval of
holding of half of the shares is minimized.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Band Clustering for the Lossless Compression of AVIRIS Hyperspectral ImagesIDES Editor
Hyperspectral images can be efficiently compressed
through a linear predictive model, as for example the one
used in the SLSQ algorithm. In this paper we exploit this
predictive model on the AVIRIS images by individuating,
through an off-line approach, a common subset of bands, which
are not spectrally related with any other bands. These bands
are not useful as prediction reference for the SLSQ 3-D
predictive model and we need to encode them via other
prediction strategies which consider only spatial correlation.
We have obtained this subset by clustering the AVIRIS bands
via the clustering by compression approach. The main result
of this paper is the list of the bands, not related with the
others, for AVIRIS images. The clustering trees obtained for
AVIRIS and the relationship among bands they depict is also
an interesting starting point for future research.
Microelectronic Circuit Analogous to Hydrogen Bonding Network in Active Site ...IDES Editor
A microelectronic circuit of block-elements
functionally analogous to two hydrogen bonding networks is
investigated. The hydrogen bonding networks are extracted
from â-lactamase protein and are formed in its active site.
Each hydrogen bond of the network is described in equivalent
electrical circuit by three or four-terminal block-element.
Each block-element is coded in Matlab. Static and dynamic
analyses are performed. The resultant microelectronic circuit
analogous to the hydrogen bonding network operates as
current mirror, sine pulse source, triangular pulse source as
well as signal modulator.
Texture Unit based Monocular Real-world Scene Classification using SOM and KN...IDES Editor
In this paper a method is proposed to discriminate
real world scenes in to natural and manmade scenes of similar
depth. Global-roughness of a scene image varies as a function
of image-depth. Increase in image depth leads to increase in
roughness in manmade scenes; on the contrary natural scenes
exhibit smooth behavior at higher image depth. This particular
arrangement of pixels in scene structure can be well explained
by local texture information in a pixel and its neighborhood.
Our proposed method analyses local texture information of a
scene image using texture unit matrix. For final classification
we have used both supervised and unsupervised learning using
K-Nearest Neighbor classifier (KNN) and Self Organizing
Map (SOM) respectively. This technique is useful for online
classification due to very less computational complexity.