Introduction to perturbation theory, part-1Kiran Padhy
Perturbation theory provides an approximate method for solving quantum mechanical problems where the Hamiltonian cannot be solved exactly. It involves splitting the Hamiltonian into an exactly solvable unperturbed part (H0) and a perturbed part (H1) treated as a small disturbance. The eigenvalues and eigenstates of the full Hamiltonian are expressed as power series expansions in terms of the perturbation strength parameter λ, allowing the effects of the perturbation to be calculated order by order. There are two types of perturbation theory: time-independent, where the unperturbed eigenstates are stationary; and time-dependent, where they vary with time under the perturbation.
Computational chemistry uses numerical simulations based on the laws of physics to model chemical structures and reactions. There are different types of computational models of varying accuracy and computational cost, including molecular mechanics, semi-empirical, ab initio, and density functional theory methods. The accuracy of calculations also depends on the basis set used to describe molecular orbitals. Computational chemistry has become an important tool for characterizing nanomaterials.
The document discusses Lagrange's equations for describing the motion of particles and systems with constraints. It provides an example of using generalized coordinates to derive the equation of motion for a simple pendulum in terms of the angular coordinate φ. The Lagrangian approach eliminates constraint forces and allows problems to be solved in any coordinate system using Lagrange's equations.
Density functional theory (DFT) is a computational quantum mechanics modeling method used in physics and chemistry to investigate the electronic structure of molecules and condensed phases. DFT was awarded the 1998 Nobel Prize in Chemistry. DFT approximates the complex quantum many-body problem by considering electron density as a basic variable instead of wave functions. Common approximations include the local density approximation (LDA) and generalized gradient approximation (GGA), which include additional information about the density gradient. DFT is widely used today due to its good accuracy and scaling better than other computational methods.
Central problem in mechanics is describing a system's mechanical state and how it evolves over time. Three formulations include Galileo/Newton using coordinates and velocities, Lagrange using generalized coordinates and velocities, and Hamilton using positions and momenta in phase space.
Time homogeneity leads to conservation of energy from the Lagrangian not explicitly depending on time. Space homogeneity leads to conservation of momentum from the Lagrangian being independent of position coordinates. Noether's theorem links symmetries like time and space homogeneity to conserved quantities like energy and momentum.
1. Hartree-Fock theory describes molecules using a linear combination of atomic orbitals to approximate molecular orbitals. It treats electrons as independent particles moving in the average field of other electrons.
2. The Hartree-Fock method involves iteratively solving the Fock equations until self-consistency is reached between the input and output orbitals. This approximates electron correlation by including an average electron-electron repulsion term.
3. The Hartree-Fock method satisfies the Pauli exclusion principle through the use of Slater determinants, which are antisymmetric wavefunctions that go to zero when the spatial or spin coordinates of any two electrons are identical.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
This document discusses fractional calculus and its history. Fractional calculus generalizes differentiation and integration to non-integer orders, starting in the 17th century with ideas from Leibniz. It provides definitions for fractional integration using the Riemann-Liouville approach and fractional differentiation as the inverse of fractional integration. The document serves as an introduction to fractional kinetics and optimal control problems.
Introduction to perturbation theory, part-1Kiran Padhy
Perturbation theory provides an approximate method for solving quantum mechanical problems where the Hamiltonian cannot be solved exactly. It involves splitting the Hamiltonian into an exactly solvable unperturbed part (H0) and a perturbed part (H1) treated as a small disturbance. The eigenvalues and eigenstates of the full Hamiltonian are expressed as power series expansions in terms of the perturbation strength parameter λ, allowing the effects of the perturbation to be calculated order by order. There are two types of perturbation theory: time-independent, where the unperturbed eigenstates are stationary; and time-dependent, where they vary with time under the perturbation.
Computational chemistry uses numerical simulations based on the laws of physics to model chemical structures and reactions. There are different types of computational models of varying accuracy and computational cost, including molecular mechanics, semi-empirical, ab initio, and density functional theory methods. The accuracy of calculations also depends on the basis set used to describe molecular orbitals. Computational chemistry has become an important tool for characterizing nanomaterials.
The document discusses Lagrange's equations for describing the motion of particles and systems with constraints. It provides an example of using generalized coordinates to derive the equation of motion for a simple pendulum in terms of the angular coordinate φ. The Lagrangian approach eliminates constraint forces and allows problems to be solved in any coordinate system using Lagrange's equations.
Density functional theory (DFT) is a computational quantum mechanics modeling method used in physics and chemistry to investigate the electronic structure of molecules and condensed phases. DFT was awarded the 1998 Nobel Prize in Chemistry. DFT approximates the complex quantum many-body problem by considering electron density as a basic variable instead of wave functions. Common approximations include the local density approximation (LDA) and generalized gradient approximation (GGA), which include additional information about the density gradient. DFT is widely used today due to its good accuracy and scaling better than other computational methods.
Central problem in mechanics is describing a system's mechanical state and how it evolves over time. Three formulations include Galileo/Newton using coordinates and velocities, Lagrange using generalized coordinates and velocities, and Hamilton using positions and momenta in phase space.
Time homogeneity leads to conservation of energy from the Lagrangian not explicitly depending on time. Space homogeneity leads to conservation of momentum from the Lagrangian being independent of position coordinates. Noether's theorem links symmetries like time and space homogeneity to conserved quantities like energy and momentum.
1. Hartree-Fock theory describes molecules using a linear combination of atomic orbitals to approximate molecular orbitals. It treats electrons as independent particles moving in the average field of other electrons.
2. The Hartree-Fock method involves iteratively solving the Fock equations until self-consistency is reached between the input and output orbitals. This approximates electron correlation by including an average electron-electron repulsion term.
3. The Hartree-Fock method satisfies the Pauli exclusion principle through the use of Slater determinants, which are antisymmetric wavefunctions that go to zero when the spatial or spin coordinates of any two electrons are identical.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
This document discusses fractional calculus and its history. Fractional calculus generalizes differentiation and integration to non-integer orders, starting in the 17th century with ideas from Leibniz. It provides definitions for fractional integration using the Riemann-Liouville approach and fractional differentiation as the inverse of fractional integration. The document serves as an introduction to fractional kinetics and optimal control problems.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
1) El documento proporciona advertencias de seguridad e instrucciones para el uso correcto de un refrigerador. 2) Incluye una descripción de las partes del refrigerador y los accesorios disponibles. 3) Explica los pasos para el primer uso, como encender el refrigerador y programar las temperaturas, y proporciona consejos para el uso y limpieza adecuados.
La historia-de-las-ecuaciones-diferenciales-ordinarias oscar garcía,marianni ...LcdoOscarGarcia
Las ecuaciones diferenciales ordinarias se originaron en el estudio de problemas dinámicos por Newton y Leibniz a finales del siglo XVII. Durante el siglo XVIII, los matemáticos resolvían ecuaciones particulares específicas, mientras que en el siglo XIX buscaban métodos de resolución aplicables a todo tipo de ecuaciones diferenciales y soluciones en serie. Los primeros métodos numéricos datan de finales del siglo XIX, pero el análisis numérico sólo fue posible a partir de 1950 con las primeras
Topological indices (t is) of the graphs to seek qsar models of proteins com...Jitendra Kumar Gupta
Currently, there is an increasing necessity for quick computational chemistry methods to predict proteins properties very accurately. This is facilitated by the improvements in various bioinformatics techniques as well as high computational power available these days. Hence quick and fast running techniques are being developed for analysing many macromolecules computationally.
In this sense, quantitative structure activity relationship (QSAR) is a widely covered field, with more than 1600 molecular descriptors introduced up to now Most of the molecular descriptors have been applied to small molecules.
Nevertheless, the QSAR studies for DNA and protein sequences may be classified as an emerging field. One of the most promising applications of QSAR to proteins relates to the prediction of thermal stability, which is an essential issue in protein science.
Connectivity indices, also called topological indices (TIs) serve fast calculations. TIs are graph invariants of different kinds of proteins.
The interest in TIs has exploded because we can use them to describe also macromolecular and macroscopic systems represented by complex networks of interactions (links) between the different parts of a system (nodes) such as: drug-target, protein-protein, metabolic, host-parasite, brain cortex, parasite disease spreading, internet, or social networks. Here, we use TI’s to analyze protein-protein complexes.
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
This document discusses nonlinear dynamical systems and modeling techniques. Nonlinear dynamical systems have multiple inputs, feedback loops, and sensitivity to initial conditions. They can be modeled using techniques like state space models, principal component analysis, neural networks, and chaos theory. Modeling nonlinear dynamical systems involves accounting for their emergent behavior from component interactions, distributed nature, and potential to evolve into chaotic states.
The document discusses first order perturbation theory. It begins by introducing perturbation theory as an approximate method to solve the Schrodinger equation for complex quantum systems where the Hamiltonian cannot be solved exactly. It then presents the key equations of first order perturbation theory. The first order correction to the energy is given by the expectation value of the perturbation operator over the unperturbed ground state wavefunction. The first order correction to the wavefunction is expressed as a linear combination of unperturbed eigenstates.
The document discusses key concepts in quantum mechanics including wave functions, probability, operators, expectation values, and normalization. Some main points:
- The wave function Ψ is a complex function that represents the quantum state of a system and |Ψ|2 gives the probability of finding a particle in a particular location.
- Operators connect the wave function to observable physical quantities. Expectation values provide the average value that would be obtained from many measurements.
- For a wave function to represent a physical state, it must be normalized such that the total probability across all possible values equals 1.
I made this presentation for my own college assignment and i had referred contents from websites and other presentations and made it presentable and reasonable hope you will like it!!!
Numerical solution of eigenvalues and applications 2SamsonAjibola
This document provides an overview of eigenvalues and their applications. It discusses:
1) Eigenvalues arise in applications across science and engineering, including mechanics, control theory, and quantum mechanics. Numerical methods are used to solve increasingly large eigenvalue problems.
2) Common methods for small problems include the QR and power methods. For large, sparse problems, techniques like the Krylov subspace and Arnoldi methods are used to compute a few desired eigenvalues/eigenvectors.
3) The document outlines the structure of the thesis, which will investigate methods for finding eigenvalues like Krylov subspace, power, and QR. It will also explore applications in areas like biology, statistics, and engineering.
This document discusses key concepts in functional analysis including function spaces, metric spaces, dense subsets, linear spaces, and linear functionals. It provides examples of different types of function spaces like C[a,b] and L1[a,b]. Metric spaces are defined as pairs consisting of a space X and a distance function satisfying properties like non-negativity and triangle inequality. Examples of metric spaces include R and Rn. Dense subsets are defined as sets whose closure is equal to the entire space. Linear spaces satisfy properties like vector addition and scalar multiplication. Linear functionals are functions that map elements of a linear space to real numbers and satisfy properties like additivity and homogeneity.
In computational physics and Quantum chemistry, the Hartree–Fock (HF) method also known as self consistent method is a method of approximation for the determination of the wave function and the energy of a quantum many-body system or many electron system in a stationary state
Chaotic system and its Application in CryptographyMuhammad Hamid
A seminar on Chaotic System and Its application in cryptography specially in image encryption. Slide covers
Introduction
Bifurcation Diagram
Lyapnove Exponent
(This presentation is in .pptx format, and will display well when embedded improperly, such as on the SlideShare site. Please download at your discretion, and be sure to cite your source)
Review of the Hartree-Fock algorithm for the Self-Consistent Field solution of the electronic Schroedinger equation. This talk also serves to highlight some basic points in Quantum Mechanics and Computational Chemistry.
March 21st, 2012
Philosophical Issues in Quantum ThermodynamicsSean Carroll
1) The document discusses several philosophical issues that arise at the foundations of quantum thermodynamics, including what constitutes measurement, the nature of probability and entropy, and how the classical world emerges from the quantum world.
2) It examines different conceptions of entropy, such as Boltzmann entropy based on macrostates and Gibbs/Shannon entropy based on probability distributions. A key question is whether entropy is objective or depends on what is known.
3) The arrow of time and why entropy increases over time is explored, as well as challenges like the reversibility objection and the role of initial conditions like the past hypothesis. The relationship between thermodynamics and cosmology is also discussed.
This document provides an overview of quantum mechanics (QM) calculation methods. It discusses molecular mechanics, wavefunction methods, electron density methods, including correlation, Hartree-Fock theory, semi-empirical methods, density functional theory, and their relative speed and accuracy. Key aspects that can be calculated using these methods are also listed, such as molecular orbitals, electron density, geometry, energies, spectroscopic properties, and more. Basis sets and handling open-shell systems in calculations are also covered.
The document summarizes the Kronig-Penny model, which models an electron in a one-dimensional periodic potential. It describes how the potential is a periodic square wave, allowing the Schrodinger equation to be solved analytically. It then shows the solution of the Schrodinger equation, expressing the eigenfunctions as a linear combination of periodic functions with a periodicity of the potential width. By applying boundary conditions and the translation operator over multiple periods, it derives an expression for the allowed wavevectors and thus the dispersion relation of the model.
Perturbation theory allows approximations of quantum systems where exact solutions cannot be easily determined. It involves splitting the Hamiltonian into known and perturbative terms. For the helium atom, the zero-order approximation treats it as two independent hydrogen atoms, yielding the wrong energy. The first-order approximation includes repulsion between electrons, giving a better but still incorrect energy. Variational theory provides an energy always greater than or equal to the actual energy.
In this talk I will discuss different approximations in DFT: pseduo-potentials, exchange correlation functions.
The presentation can be downloaded here:
http://www.attaccalite.com/wp-content/uploads/2022/03/dft_approximations.odp
Chaos theory deals with nonlinear and complex systems that are highly sensitive to initial conditions. These systems, while deterministic, are largely unpredictable due to this sensitivity. Lorenz discovered this "butterfly effect" through modeling atmospheric convection. Chaotic systems evolve toward attractors, which can be fixed points, limit cycles, or strange attractors exhibiting fractal geometry. This geometry is seen throughout nature. While chaotic systems cannot be precisely predicted, control methods like Ott-Grebogi-Yorke can influence their behavior. Chaos theory has applications across many domains.
Chaos theory is a mathematical field of study which states that non-linear dynamical systems
that are seemingly random are actually deterministic from much simpler equations. The
phenomenon of Chaos theory was introduced to the modern world by Edward Lorenz in 1972
with conceptualization of ‘Butterfly Effect’. As chaos theory was developed by inputs of
various mathematicians and scientists, it found applications in a large number of scientific
fields.
The purpose of the project is the interpretation of chaos theory which is not as familiar as
other theories. Everything in the universe is in some way or the other under control of Chaos
or product of Chaos. Every motion, behavior or tendency can be explained by Chaos Theory.
The prime objective of it is the illustration of Chaos Theory and Chaotic behavior.
This project includes origin, history, fields of application, real life application and limitations
of Chaos Theory. It explores understanding complexity and dynamics of Chaos.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
1) El documento proporciona advertencias de seguridad e instrucciones para el uso correcto de un refrigerador. 2) Incluye una descripción de las partes del refrigerador y los accesorios disponibles. 3) Explica los pasos para el primer uso, como encender el refrigerador y programar las temperaturas, y proporciona consejos para el uso y limpieza adecuados.
La historia-de-las-ecuaciones-diferenciales-ordinarias oscar garcía,marianni ...LcdoOscarGarcia
Las ecuaciones diferenciales ordinarias se originaron en el estudio de problemas dinámicos por Newton y Leibniz a finales del siglo XVII. Durante el siglo XVIII, los matemáticos resolvían ecuaciones particulares específicas, mientras que en el siglo XIX buscaban métodos de resolución aplicables a todo tipo de ecuaciones diferenciales y soluciones en serie. Los primeros métodos numéricos datan de finales del siglo XIX, pero el análisis numérico sólo fue posible a partir de 1950 con las primeras
Topological indices (t is) of the graphs to seek qsar models of proteins com...Jitendra Kumar Gupta
Currently, there is an increasing necessity for quick computational chemistry methods to predict proteins properties very accurately. This is facilitated by the improvements in various bioinformatics techniques as well as high computational power available these days. Hence quick and fast running techniques are being developed for analysing many macromolecules computationally.
In this sense, quantitative structure activity relationship (QSAR) is a widely covered field, with more than 1600 molecular descriptors introduced up to now Most of the molecular descriptors have been applied to small molecules.
Nevertheless, the QSAR studies for DNA and protein sequences may be classified as an emerging field. One of the most promising applications of QSAR to proteins relates to the prediction of thermal stability, which is an essential issue in protein science.
Connectivity indices, also called topological indices (TIs) serve fast calculations. TIs are graph invariants of different kinds of proteins.
The interest in TIs has exploded because we can use them to describe also macromolecular and macroscopic systems represented by complex networks of interactions (links) between the different parts of a system (nodes) such as: drug-target, protein-protein, metabolic, host-parasite, brain cortex, parasite disease spreading, internet, or social networks. Here, we use TI’s to analyze protein-protein complexes.
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
This document discusses nonlinear dynamical systems and modeling techniques. Nonlinear dynamical systems have multiple inputs, feedback loops, and sensitivity to initial conditions. They can be modeled using techniques like state space models, principal component analysis, neural networks, and chaos theory. Modeling nonlinear dynamical systems involves accounting for their emergent behavior from component interactions, distributed nature, and potential to evolve into chaotic states.
The document discusses first order perturbation theory. It begins by introducing perturbation theory as an approximate method to solve the Schrodinger equation for complex quantum systems where the Hamiltonian cannot be solved exactly. It then presents the key equations of first order perturbation theory. The first order correction to the energy is given by the expectation value of the perturbation operator over the unperturbed ground state wavefunction. The first order correction to the wavefunction is expressed as a linear combination of unperturbed eigenstates.
The document discusses key concepts in quantum mechanics including wave functions, probability, operators, expectation values, and normalization. Some main points:
- The wave function Ψ is a complex function that represents the quantum state of a system and |Ψ|2 gives the probability of finding a particle in a particular location.
- Operators connect the wave function to observable physical quantities. Expectation values provide the average value that would be obtained from many measurements.
- For a wave function to represent a physical state, it must be normalized such that the total probability across all possible values equals 1.
I made this presentation for my own college assignment and i had referred contents from websites and other presentations and made it presentable and reasonable hope you will like it!!!
Numerical solution of eigenvalues and applications 2SamsonAjibola
This document provides an overview of eigenvalues and their applications. It discusses:
1) Eigenvalues arise in applications across science and engineering, including mechanics, control theory, and quantum mechanics. Numerical methods are used to solve increasingly large eigenvalue problems.
2) Common methods for small problems include the QR and power methods. For large, sparse problems, techniques like the Krylov subspace and Arnoldi methods are used to compute a few desired eigenvalues/eigenvectors.
3) The document outlines the structure of the thesis, which will investigate methods for finding eigenvalues like Krylov subspace, power, and QR. It will also explore applications in areas like biology, statistics, and engineering.
This document discusses key concepts in functional analysis including function spaces, metric spaces, dense subsets, linear spaces, and linear functionals. It provides examples of different types of function spaces like C[a,b] and L1[a,b]. Metric spaces are defined as pairs consisting of a space X and a distance function satisfying properties like non-negativity and triangle inequality. Examples of metric spaces include R and Rn. Dense subsets are defined as sets whose closure is equal to the entire space. Linear spaces satisfy properties like vector addition and scalar multiplication. Linear functionals are functions that map elements of a linear space to real numbers and satisfy properties like additivity and homogeneity.
In computational physics and Quantum chemistry, the Hartree–Fock (HF) method also known as self consistent method is a method of approximation for the determination of the wave function and the energy of a quantum many-body system or many electron system in a stationary state
Chaotic system and its Application in CryptographyMuhammad Hamid
A seminar on Chaotic System and Its application in cryptography specially in image encryption. Slide covers
Introduction
Bifurcation Diagram
Lyapnove Exponent
(This presentation is in .pptx format, and will display well when embedded improperly, such as on the SlideShare site. Please download at your discretion, and be sure to cite your source)
Review of the Hartree-Fock algorithm for the Self-Consistent Field solution of the electronic Schroedinger equation. This talk also serves to highlight some basic points in Quantum Mechanics and Computational Chemistry.
March 21st, 2012
Philosophical Issues in Quantum ThermodynamicsSean Carroll
1) The document discusses several philosophical issues that arise at the foundations of quantum thermodynamics, including what constitutes measurement, the nature of probability and entropy, and how the classical world emerges from the quantum world.
2) It examines different conceptions of entropy, such as Boltzmann entropy based on macrostates and Gibbs/Shannon entropy based on probability distributions. A key question is whether entropy is objective or depends on what is known.
3) The arrow of time and why entropy increases over time is explored, as well as challenges like the reversibility objection and the role of initial conditions like the past hypothesis. The relationship between thermodynamics and cosmology is also discussed.
This document provides an overview of quantum mechanics (QM) calculation methods. It discusses molecular mechanics, wavefunction methods, electron density methods, including correlation, Hartree-Fock theory, semi-empirical methods, density functional theory, and their relative speed and accuracy. Key aspects that can be calculated using these methods are also listed, such as molecular orbitals, electron density, geometry, energies, spectroscopic properties, and more. Basis sets and handling open-shell systems in calculations are also covered.
The document summarizes the Kronig-Penny model, which models an electron in a one-dimensional periodic potential. It describes how the potential is a periodic square wave, allowing the Schrodinger equation to be solved analytically. It then shows the solution of the Schrodinger equation, expressing the eigenfunctions as a linear combination of periodic functions with a periodicity of the potential width. By applying boundary conditions and the translation operator over multiple periods, it derives an expression for the allowed wavevectors and thus the dispersion relation of the model.
Perturbation theory allows approximations of quantum systems where exact solutions cannot be easily determined. It involves splitting the Hamiltonian into known and perturbative terms. For the helium atom, the zero-order approximation treats it as two independent hydrogen atoms, yielding the wrong energy. The first-order approximation includes repulsion between electrons, giving a better but still incorrect energy. Variational theory provides an energy always greater than or equal to the actual energy.
In this talk I will discuss different approximations in DFT: pseduo-potentials, exchange correlation functions.
The presentation can be downloaded here:
http://www.attaccalite.com/wp-content/uploads/2022/03/dft_approximations.odp
Chaos theory deals with nonlinear and complex systems that are highly sensitive to initial conditions. These systems, while deterministic, are largely unpredictable due to this sensitivity. Lorenz discovered this "butterfly effect" through modeling atmospheric convection. Chaotic systems evolve toward attractors, which can be fixed points, limit cycles, or strange attractors exhibiting fractal geometry. This geometry is seen throughout nature. While chaotic systems cannot be precisely predicted, control methods like Ott-Grebogi-Yorke can influence their behavior. Chaos theory has applications across many domains.
Chaos theory is a mathematical field of study which states that non-linear dynamical systems
that are seemingly random are actually deterministic from much simpler equations. The
phenomenon of Chaos theory was introduced to the modern world by Edward Lorenz in 1972
with conceptualization of ‘Butterfly Effect’. As chaos theory was developed by inputs of
various mathematicians and scientists, it found applications in a large number of scientific
fields.
The purpose of the project is the interpretation of chaos theory which is not as familiar as
other theories. Everything in the universe is in some way or the other under control of Chaos
or product of Chaos. Every motion, behavior or tendency can be explained by Chaos Theory.
The prime objective of it is the illustration of Chaos Theory and Chaotic behavior.
This project includes origin, history, fields of application, real life application and limitations
of Chaos Theory. It explores understanding complexity and dynamics of Chaos.
This presentation discusses chaos theory and the butterfly effect. It begins with an introduction that defines the butterfly effect as how small variations can dramatically change the outcome of a system over time. There are three types of systems: linear, random, and chaotic, which are deterministic yet unpredictable long-term.
The history section describes how meteorologist Edward Lorenz discovered the butterfly effect in 1961 when a small variation in input data led to vastly different weather model outputs. The term "butterfly effect" comes from a 1972 quote about whether a butterfly could cause a tornado.
Applications of chaos theory discussed include weather prediction, stock markets, biology, physics, evolution, fractals, aviation safety, traffic patterns, psychology, and time travel
Introducing Undergraduate Electrical Engineering Students to Chaotic Dynamics...Sajid Iqbal
In current undergraduate electrical engineering, the emphasis on linear systems develops a way of thinking that dismisses nonlinear dynamics as spurious oscillations. The linear systems approach oversimplifies the dynamics of nonlinear systems. This talk helps students understand chaotic behavior using simulations of a continuous-time circuit and a discrete-time system. The undergraduate students and teachers can recognize the educational value of chaotic phenomena from them.
The 6-week online course aims to teach participants about vulnerability assessment, accessing mitigation resources, and planning/implementing CDRM programs. It will use discussion forums, assignments, quizzes and a final project. The facilitator will provide structure and support to help participants learn and ensure the course runs smoothly. Challenges may include technical issues and discussion conflicts, but the facilitator has strategies to overcome difficulties.
Creative Chaos: Banking & Finance Portfolio 2011Ahmar Hasan
Creative Chaos is a software development company established in 2000 that provides custom applications to both local and international clients. It has over 50 active customers and has provided services to over 400 clients total. The company focuses on web development, software development, and quality assurance, and has experience working with companies across many industries. It is ISO 9001:2008 certified and has a team of over 130 full-time employees and consultants.
This project investigated whether the Feigenbaum number and Lyapunov exponent, which characterize chaos, are universal across different chaotic systems. Computational programs were developed to plot bifurcation diagrams and Lyapunov exponent plots for various maps, including the logistic, sine, and Gaussian maps. The results showed that the logistic and sine maps exhibited similar bifurcation structures and Lyapunov exponent behavior, indicating these characteristics are universal for unimodal maps. In contrast, the Gaussian map displayed distinct bifurcation and exponent patterns, only becoming briefly chaotic before returning to periodic behavior.
This document discusses thermodynamic properties and relationships for homogeneous phases. It defines key concepts like internal energy, enthalpy, entropy, and Gibbs free energy. Equations are derived relating these properties to temperature and pressure. The relationships show that entropy decreases with increasing pressure as particles are confined to a smaller space, reducing disorder. Gibbs free energy can be used to predict spontaneity of reactions according to the second law of thermodynamics.
Dynamics, control and synchronization of some models of neuronal oscillatorsUniversité de Dschang
1. The paper studies the effect of dynamic chemical and electrical synapses on phase synchronization in coupled bursting neurons. It considers a model where neurons are coupled through both delayed electrical (linear) and delayed chemical (nonlinear) interactions.
2. Chemical synapses are modeled using a sigmoid function representing steady-state synaptic activation. Electrical synapses provide instantaneous coupling between neurons.
3. The study finds that both the delay in chemical synapses and the relative strength of electrical and chemical coupling can induce phase transitions between synchronized and desynchronized states in the neuronal network. Understanding these effects provides insights into information processing in neuronal circuits involving multiple synaptic interactions.
The document discusses chaos theory, fractals, and their application in art. It explains that chaos theory studies bringing order to disorder in mathematics and physics. The butterfly effect demonstrates how small changes can lead to large unpredictable consequences. Fractals are never-ending patterns that repeat at increasingly smaller scales found in nature. Benoit Mandelbrot coined the term fractal and drove interest in fractal geometry. The document provides examples of the author's art applying fractal patterns and chaos theory concepts.
On the Dynamics and Synchronization of a Class of Nonlinear High Frequency Ch...Université de Dschang
M. Kamdoum Tamba Victor a effectué cette présentation dans le cadre de la soutenance publique de sa thèse de Doctorat en Physique, option électronique le 30 mars 2016 dans la salle des conférences de l'Université de Dschang. A l'issue de la défense, le jury présidé par le professeur Paul Woafo lui a décerné la mention Très honorable à l'unanimité de ses membres. Ce jury lui a par ailleurs adressé ses félicitations verbales.
This document provides an overview of chaos theory, including:
1) It defines chaos as the apparently noisy, aperiodic behavior in deterministic systems that is sensitive to initial conditions.
2) Important milestones in chaos theory research are discussed, from Poincare in 1890 to fractal geometry work in the 1970s.
3) Attractors, strange attractors, and fractal geometry are introduced as important concepts.
4) Methods for measuring chaos like Lyapunov exponents and entropy are described.
Project managers face increasing pressures that often result in chaos. They are expected to manage more projects with tighter deadlines and budgets while constantly being accessible. This leads to inefficient collaboration practices and wasted time. While technology aims to help, it also introduces new challenges around communication methods, data security, and version control. Project managers feel overworked and out of their comfort zone as work pressures mount. They report that projects regularly run over budget and timelines slip when they have too many projects. New tools are needed to help project managers work smarter and foster better collaboration.
Maths scert text book model, chapter 7,statisticsVinya P
This document provides instructions for making frequency tables and histograms from raw data. It discusses how to group raw data into appropriate class intervals for a frequency table. The key steps are counting the frequency of each class, recording the results in a table, and then representing the frequency table graphically as a histogram by drawing rectangles for each class with height proportional to frequency. Examples are given of making frequency tables and histograms from various data sets, including student test scores, temperatures, wages, and heights.
This document discusses systems and chaos theory. It explains that complex adaptive systems like ant colonies, organizations, and markets are made up of interacting agents that self-organize through evolving rules and a dynamic environment. While such systems can exist in states of stasis or chaos with shifting patterns, order can still emerge from their complex and unpredictable behaviors. The document provides sources on chaos theory and systems theory and how they apply to understanding cities, ecosystems, and other complex systems.
Although, chaos/complexity theory and SLA have commonplaces, they seem to be different in that chaos/complexity theory offers the wider perspective that has served SLA in the past. As opposed to SLA, chaos/complexity theory encourages linguists to think in relational terms. It refers to the fact that by accepting participation metaphor/language use/emergent grammar position, chaos/complexity theory does not reject psychological perspective. As it is stated , chaos complexity theory like socialists focus on the following issues: 1. all languages are static 2. there are mechanisms for language change 3.language and learning are seen as an open systems.
Nevertheless, C/CT never rejects the following characteristics which psychological perspective focuses on: 1. languages are sensitive to initial conditions 2. there are systemic patterns with dynamic paths.
The document discusses using a symbolic mechanics software called Mechanical Expressions to model chaotic dynamical systems. It defines key terms like dynamical systems and chaos theory. Three main tests are described to identify chaos: the sensitivity test, mixing test, and Fourier transform test. These are applied to a model of a flywheel system to test for chaotic behavior. While useful, the tests each have limitations and no single test can definitively prove a system is chaotic.
1) The document outlines J.C. Sprott's presentation about modeling chaotic data and strange attractors from an artistic and scientific perspective. 2) Examples of properties of strange attractors are discussed, including fractal structure, non-integer dimension, and sensitivity to initial conditions. Scaling laws for attractor dimension and Lyapunov exponents are also covered. 3) New simple chaotic flows and electrical circuits discovered by Sprott and others are presented as having aesthetic appeal worthy of consideration beyond pure science.
This document summarizes a physics colloquium presentation about strange attractors in chaotic systems. Strange attractors are fractal patterns that arise in some dynamical systems and are characterized by sensitivity to initial conditions and having a non-integer fractal dimension. The presentation outlines examples of strange attractors like the Lorenz and Hénon attractors. It discusses properties of strange attractors like attractor dimension and Lyapunov exponents. It also shows that chaos is more common at higher dimensions and in neural networks, and evaluates the aesthetic appeal of strange attractors.
This document provides an outline for a lecture on complex dynamics in Hamiltonian systems. Some key points:
1) Simple periodic orbits called nonlinear normal modes exist and can destabilize, leading to weak or strong chaos depending on their properties.
2) Dynamical indicators like Lyapunov exponents and the Generalized Alignment Index (GALI) can identify regions of order and chaos. The Lyapunov spectrum indicates when orbits explore the same chaotic region.
3) GALI rapidly detects chaos as deviation vectors become aligned, and identifies quasiperiodic motion by vectors remaining independent. It distinguishes weak and strong chaos based on exponential decay rates.
Euler lagrange equations of motion mit-holonomic constraints_lecture7JOHN OBIDI
Lagrange's equations provide an alternative method to Newton's laws for deriving the equations of motion for mechanical systems. Lagrange's method uses generalized coordinates and the kinetic and potential energies of the system to derive scalar differential equations, avoiding the need to solve for constraint forces or accelerations directly. The number of degrees of freedom for a system, which determines the number of differential equations needed, depends only on the number of coordinates and constraints and is independent of the particular coordinate system used.
This document describes OpenLCDFDM, an open-source finite-difference LCD simulator. It summarizes the key components of LCD display structure and models used in the simulator, including the birefringence of liquid crystals, calculation of liquid crystal orientation under electric fields using the Oseen-Frank model, solving the Laplace equation in anisotropic media, and using the extended Jones matrix method for optical calculations. The document also outlines the program structure and demonstrates simulation results for different LCD modes. Future work is proposed to improve the modeling capabilities.
This document summarizes research on quantum chaos, including the principle of uniform semiclassical condensation of Wigner functions, spectral statistics in mixed systems, and dynamical localization of chaotic eigenstates. It discusses how in the semiclassical limit, Wigner functions condense uniformly on classical invariant components. For mixed systems, the spectrum can be seen as a superposition of regular and chaotic level sequences. Localization effects can be observed if the Heisenberg time is shorter than the classical diffusion time. The document presents an analytical formula called BRB that describes the transition between Poisson and random matrix statistics. An example is given of applying this to analyze the level spacing distribution for a billiard system.
Wang-Landau Monte Carlo simulation is a method for calculating the density of states function which can then be used to calculate thermodynamic properties like the mean value of variables. It improves on traditional Monte Carlo methods which struggle at low temperatures due to complicated energy landscapes with many local minima separated by large barriers. The Wang-Landau algorithm calculates the density of states function directly rather than relying on sampling configurations, allowing it to overcome barriers and fully explore the configuration space even at low temperatures.
This document provides an introduction to quantum Monte Carlo methods. It discusses using Monte Carlo integration to evaluate multi-dimensional integrals that arise in quantum mechanical problems. Variational Monte Carlo is introduced as using a trial wavefunction to sample configuration space and estimate observables, like the energy. The Metropolis algorithm is described as a way to generate Markov chains that sample a given probability distribution. This allows using Monte Carlo methods to solve the electronic structure problem by approximating many-body wavefunctions and integrals over configuration space.
1. Hartree-Fock theory describes molecules using a linear combination of atomic orbitals to approximate molecular orbitals. It treats electrons as independent particles moving in the average field of other electrons.
2. The Hartree-Fock method involves iteratively solving the Fock equations until self-consistency is reached between the input and output orbitals. This approximates electron correlation by including an average electron-electron repulsion term.
3. The Hartree-Fock approach satisfies the Pauli exclusion principle through the use of Slater determinants, which are antisymmetric wavefunctions that go to zero when the spatial or spin coordinates of any two electrons are identical.
Characterization of Subsurface Heterogeneity: Integration of Soft and Hard In...Amro Elfeki
Park, E., Elfeki, A. M. M., Dekking, F.M. (2003). Characterization of subsurface heterogeneity: Integration of soft and hard information using multi-dimensional Coupled Markov chain approach. Underground Injection Science and Technology Symposium, Lawrence Berkeley National Lab., October 22-25, 2003. p.49. Eds. Tsang, Chin.-Fu and Apps, John A.
http://www.lbl.gov/Conferences/UIST/index.html#topics
Computational Motor Control: Kinematics & Dynamics (JAIST summer course)hirokazutanaka
Computational Motor Control: Kinematics & Dynamics (JAIST summer course)
This is lecture 1 note for JAIST summer school on computational motor control (Hirokazu Tanaka & Hiroyuki Kambara). Lecture video: https://www.youtube.com/watch?v=8nk4DlpAaS8
- The atom consists of a small, dense nucleus surrounded by an electron cloud.
- Electrons can only exist in certain discrete energy levels around the nucleus. Their wavelengths are determined by the principal quantum number.
- The Bohr model improved on earlier models by introducing energy levels and quantization, but had limitations. The quantum mechanical model treats electrons as waves and uses Schrodinger's equation.
This document discusses nonlinear optics and summarizes key topics covered:
- It describes the difference between linear and nonlinear optics, where linear optics involves weak light that is unchanged and nonlinear optics involves intense light that can induce effects and be manipulated.
- Nonlinear optics allows changing light properties like color and shape, and has applications in telecommunications and creating ultrashort events.
- Phenomena like sum and difference frequency generation are examples of second-order nonlinear optical effects. Phase matching is important for efficient nonlinear optical processes.
- Applications of nonlinear optics include optical phase conjugation, optical parametric oscillators, optical computing, optical switching, and optical data storage.
The document provides an outline for a course on quantum mechanics. It discusses key topics like the time-dependent Schrodinger equation, eigenvalues and eigenfunctions, boundary conditions for wave functions, and applications like the particle in a box model. Specific solutions to the Schrodinger equation are explored for stationary states with definite energy, including the wave function for a free particle and the quantization of energy for a particle confined to a one-dimensional box.
This document provides an overview of Cedric Weber's background and research interests, which include dynamical mean field theory (DMFT) and its application to oxide materials. Some key points:
- Cedric Weber received his PhD in quantum magnetism and superconductivity from EPFL and has worked on DMFT at Rutgers and the University of Cambridge. He is currently a researcher at King's College London.
- His research focuses on developing DMFT software and studying phase diagrams of high-temperature superconductors and other oxide materials using techniques like DMFT, GW+DMFT, and the Bethe-Salpeter equation.
- He collaborates with theorists and experimentalists on topics like laser
This document provides an overview of fundamentals of electromagnetics. It introduces key concepts such as coordinate systems, vector analysis, Maxwell's equations, and electromagnetic waves. Coordinate systems discussed include Cartesian, cylindrical, and spherical. Vector analysis tools like del operator, gradient, and divergence are explained. Maxwell's equations govern electromagnetics and electromagnetic waves. Understanding these fundamental concepts is important for studying communication systems where signals are transmitted as electromagnetic waves using devices like antennas.
The document outlines the syllabus for a course on digital signal processing. It includes 5 units: 1) Introduction to signals and systems, 2) Discrete time system analysis using z-transforms, 3) Discrete Fourier transforms and computation including fast Fourier transforms, 4) Design of digital filters including FIR and IIR filters, and 5) Digital signal processors and their architecture. It allocates a total of 45 periods to cover these topics. Textbooks recommended for the course provide further information on digital signal processing principles, algorithms, and applications.
This document provides an introduction to nuclear magnetic resonance (NMR) spectroscopy. It begins with an overview of NMR and spectroscopy. It then reviews common units used in NMR such as time, temperature, magnetic field strength, energy, and frequency. The document consists of introductory chapters that cover topics like the basics of NMR, mathematics relevant to NMR, spin physics, and energy levels. It provides explanations of fundamental NMR concepts such as spin, magnetic moments, energy states, resonance frequency, and relaxation times T1 and T2. The overall document serves as a comprehensive primer on basic NMR principles.
The document summarizes quantum numbers and selection rules for quantum mechanical systems. It discusses the three quantum numbers - principal (n), orbital angular momentum (l), and magnetic (ml) quantum numbers. Selection rules for transitions between energy levels are determined by calculating oscillating expectation values. Only transitions where the quantum numbers change by specific values (e.g. l changes by ±1) are allowed. The document also discusses how angular momentum is quantized in quantum mechanics and relates to the quantum numbers l and ml.
Knowledge of cause-effect relationships is central to the field of climate science, supporting mechanistic understanding, observational sampling strategies, experimental design, model development and model prediction. While the major causal connections in our planet's climate system are already known, there is still potential for new discoveries in some areas. The purpose of this talk is to make this community familiar with a variety of available tools to discover potential cause-effect relationships from observed or simulation data. Some of these tools are already in use in climate science, others are just emerging in recent years. None of them are miracle solutions, but many can provide important pieces of information to climate scientists. An important way to use such methods is to generate cause-effect hypotheses that climate experts can then study further. In this talk we will (1) introduce key concepts important for causal analysis; (2) discuss some methods based on the concepts of Granger causality and Pearl causality; (3) point out some strengths and limitations of these approaches; and (4) illustrate such methods using a few real-world examples from climate science.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
BREEDING METHODS FOR DISEASE RESISTANCE.pptxRASHMI M G
Plant breeding for disease resistance is a strategy to reduce crop losses caused by disease. Plants have an innate immune system that allows them to recognize pathogens and provide resistance. However, breeding for long-lasting resistance often involves combining multiple resistance genes
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptx
Logistic map
1. Chaos theory and Logistic maps
Summer Project Report
Narendra Kumar
Supervisor: Prof. Srikanth Sastry
2. Future Plan:
Topological Entropy : Quantify chaos
➢ Calculation of Topological entropy for higher dimensional map
➢ Calculation of topological entropy in spin-glass
3. Q.Why and how we study non-linear dynamics?
Ans. Most of the systems are non-linear in nature. A theoretical study of such a
system leads to the solution of nonlinear differential equation. we can extract
a lot of informations about solution from the equation themselves. If the
dynamical systems be autonomous systems then it can be decomposed Into
coupled first order differential equations and then can be solved computationally.
Chaos:
Its main features are :
➢ extreme sensitivity to initial conditions
➢ Non-linearity
➢ strangeness
“Edward Lorenz” described chaos as “when the present determines the future, but
the approximate present doesn't approximately determines the future”.
4. Lyapunov Exponent: Sensitivity to initial conditions and parameters of a
non-linear system is determined by the value of Lyapunov exponent.
n
λ = lim (1/n) ∑ |df(xi
)/dx|
n→∞ i=0
If λ (<>0) then orbit is stable, unstable(show chaos).
Arnold Transform: a n×n pixel size 2D image and transform each point
(x,y) by transformation equation Γ : (x,y) → (x+y,x+2y) mod n after a
finite no. of iteration(say k) same image is restored. But there is no any
specific relation between k & n.
11. Applications:
(1)weather prediction
(2)population growth
(3)cardiotocography
(4) signal analysis
(5) random number generator
(6) Information theory
(7) optics
References:
(1)Periodic entrainment of chaotic logistic map dynamics:E. Atlee Jackson, Alfred Hübler
(2)Lyapunov graph for two-parameters map: Application to the circle map by Figueiredo
(3)Deterministic Non-periodic flow: Edward N. Lorenz
(4)Nonlinear dynamics and chaos (Book) : Strogatz
(5) Arnold cat map : Gabriel Peterson