The document discusses direct torque control (DTC) of induction motors using conventional and space vector pulse width modulation (SVPWM) methods. It aims to simulate DTC of induction motors using these two methods, with SVPWM proposed to reduce torque ripple compared to the conventional method. The direct torque control method estimates motor flux and torque from measured voltage and current to control torque and thereby speed without requiring complex reference frame transformations. Space vector PWM is expected to provide smoother torque control through finer voltage vector selection compared to the basic hysteresis control of conventional DTC.
Transformers operate by exploiting the principle of mutual inductance between two coils. They are used to convert alternating current (AC) voltages from one level to another. An ideal transformer consists of two coils wound on a common magnetic core, with no direct electrical connection between them. Current flowing through the primary coil produces a changing magnetic flux that induces a voltage in the secondary coil. Transformers are widely used in power distribution systems to increase or decrease voltages as needed.
The document describes a magnetic levitation system that uses an electromagnet to levitate a small magnet. A Hall effect sensor measures the vertical position of the levitating magnet and a digital signal controller controls the current in the electromagnet coil through pulse-width modulation to maintain the magnet's level of levitation. The system provides feedback to stabilize the levitating material's position and compensate for disturbances through varying the current in the electromagnet coil.
The document describes a magnetic levitation system that uses an electromagnet to levitate a small magnet. A Hall effect sensor measures the vertical position of the levitating magnet and a digital signal controller controls the current in the electromagnet coil through pulse-width modulation to maintain the magnet's level of levitation. The system provides feedback to stabilize the levitating material's position and compensate for disturbances through varying the current in the electromagnet coil.
- Induction heating uses an alternating magnetic field generated by an induction coil to heat conductive materials through the induction of eddy currents. There are two heating mechanisms: eddy current heating which occurs in all conductive materials, and hysteresis heating which only occurs in magnetic materials.
- The key principles are that the alternating magnetic field from the coil induces voltages in the workpiece which create eddy currents, and these eddy currents generate heat. Three closed loop systems are involved: the coil current loop, the magnetic flux loop, and the eddy current loop in the workpiece.
- The reference depth is an important parameter that depends on material properties and frequency, and determines how deeply the magnetic field and heating penetrate into the
An analysis of the Lattice Boltzmann Method (LBM) has been developed as an alternating Computational Fluid Dynamic (CFD) method based on the collective behavior of microscopic particles. This numerical method contrasts
with the traditional approaches which usually consider macroscopic descriptions by using Navier-Stokes (NS) equations.The specific purpose of the present thesis is to supply a comprehensive description of the field providing a source code for practical applications under GNU copyright.
In the first part the review of the fundamental macroscopic variables is emphasized to outline the NS equations with advantages and drawbacks.
Numerical methods are investigated in the second part, evolving from Cellular Automata, the most recent Lattice Gas Cellular Automata and specially its extension, the LBM.
The last part of this thesis shows the results of the method comparing to a traditional Navier-Stokes solver. It is also pointed out the advantages adopted with LBM approach in nano-scale multiphase fluid flow under complex boundary conditions.
1) The document describes a method for avoiding Lenz's Law by using an asymmetrical arrangement of coils and permanent magnets. This allows power to be extracted from the output coil without affecting the input coil.
2) The key principle is that orthogonal coils do not normally interact, but adding permanent magnets between the coils breaks the symmetry and allows the magnetic field from one coil to induce current in the other coil.
3) The output power depends on factors like the intensity of the magnetic field from the magnets and the speed and distance of movement of this magnetic field caused by the current in the input coil. Replacing the permanent magnets with electromagnets is also proposed.
The document provides an overview of magnetics and magnetic circuits. It discusses key topics including:
- The basic principles of electromagnetism and how magnetic fields are produced by current-carrying conductors.
- Properties of magnetic fields such as magnetic lines of force and their behavior.
- Magnetic materials and their properties including ferromagnetic, paramagnetic, and diamagnetic materials.
- Key concepts in magnetic circuits such as magnetic flux, flux density, reluctance, permeability, and their analogies to electric circuits using concepts like voltage, current, resistance.
Chapter 1a: Fluxtrol Basics of Induction Techniques Part 1Fluxtrol Inc.
http://fluxtrol.com
Chapter 1a Fluxtrol Basics of Induction Techniques Part 1
Includes:
Principles of Induction Heating,
Process Control and Layout, Theory, and more.
Transformers operate by exploiting the principle of mutual inductance between two coils. They are used to convert alternating current (AC) voltages from one level to another. An ideal transformer consists of two coils wound on a common magnetic core, with no direct electrical connection between them. Current flowing through the primary coil produces a changing magnetic flux that induces a voltage in the secondary coil. Transformers are widely used in power distribution systems to increase or decrease voltages as needed.
The document describes a magnetic levitation system that uses an electromagnet to levitate a small magnet. A Hall effect sensor measures the vertical position of the levitating magnet and a digital signal controller controls the current in the electromagnet coil through pulse-width modulation to maintain the magnet's level of levitation. The system provides feedback to stabilize the levitating material's position and compensate for disturbances through varying the current in the electromagnet coil.
The document describes a magnetic levitation system that uses an electromagnet to levitate a small magnet. A Hall effect sensor measures the vertical position of the levitating magnet and a digital signal controller controls the current in the electromagnet coil through pulse-width modulation to maintain the magnet's level of levitation. The system provides feedback to stabilize the levitating material's position and compensate for disturbances through varying the current in the electromagnet coil.
- Induction heating uses an alternating magnetic field generated by an induction coil to heat conductive materials through the induction of eddy currents. There are two heating mechanisms: eddy current heating which occurs in all conductive materials, and hysteresis heating which only occurs in magnetic materials.
- The key principles are that the alternating magnetic field from the coil induces voltages in the workpiece which create eddy currents, and these eddy currents generate heat. Three closed loop systems are involved: the coil current loop, the magnetic flux loop, and the eddy current loop in the workpiece.
- The reference depth is an important parameter that depends on material properties and frequency, and determines how deeply the magnetic field and heating penetrate into the
An analysis of the Lattice Boltzmann Method (LBM) has been developed as an alternating Computational Fluid Dynamic (CFD) method based on the collective behavior of microscopic particles. This numerical method contrasts
with the traditional approaches which usually consider macroscopic descriptions by using Navier-Stokes (NS) equations.The specific purpose of the present thesis is to supply a comprehensive description of the field providing a source code for practical applications under GNU copyright.
In the first part the review of the fundamental macroscopic variables is emphasized to outline the NS equations with advantages and drawbacks.
Numerical methods are investigated in the second part, evolving from Cellular Automata, the most recent Lattice Gas Cellular Automata and specially its extension, the LBM.
The last part of this thesis shows the results of the method comparing to a traditional Navier-Stokes solver. It is also pointed out the advantages adopted with LBM approach in nano-scale multiphase fluid flow under complex boundary conditions.
1) The document describes a method for avoiding Lenz's Law by using an asymmetrical arrangement of coils and permanent magnets. This allows power to be extracted from the output coil without affecting the input coil.
2) The key principle is that orthogonal coils do not normally interact, but adding permanent magnets between the coils breaks the symmetry and allows the magnetic field from one coil to induce current in the other coil.
3) The output power depends on factors like the intensity of the magnetic field from the magnets and the speed and distance of movement of this magnetic field caused by the current in the input coil. Replacing the permanent magnets with electromagnets is also proposed.
The document provides an overview of magnetics and magnetic circuits. It discusses key topics including:
- The basic principles of electromagnetism and how magnetic fields are produced by current-carrying conductors.
- Properties of magnetic fields such as magnetic lines of force and their behavior.
- Magnetic materials and their properties including ferromagnetic, paramagnetic, and diamagnetic materials.
- Key concepts in magnetic circuits such as magnetic flux, flux density, reluctance, permeability, and their analogies to electric circuits using concepts like voltage, current, resistance.
Chapter 1a: Fluxtrol Basics of Induction Techniques Part 1Fluxtrol Inc.
http://fluxtrol.com
Chapter 1a Fluxtrol Basics of Induction Techniques Part 1
Includes:
Principles of Induction Heating,
Process Control and Layout, Theory, and more.
1. DC motors operate by converting electrical energy from a power source into mechanical energy. They consist of a stationary stator and a rotating rotor made of coils that interact with magnetic fields.
2. DC motors are classified as either separately excited, shunt, or series motors depending on how their field and armature windings are electrically connected. Separately excited motors have independent field and armature circuits while shunt and series motors have their field windings connected in parallel or series to the armature winding, respectively.
3. In a DC motor, torque is produced by the interaction between current in the rotor coils and the magnetic field from the stator. As the rotor rotates, a counter-voltage or
This document provides information about a scanning tunneling microscope (STM) including its basic operating principles, design, modes of operation, applications, and related imaging techniques. The STM works by using the quantum tunneling effect to measure electric currents between a sharp tip and conductive sample surface. This allows it to image surfaces at the atomic level with high resolution. The document outlines the key components of an STM including the sample, scanning tip, piezoelectric scanner, and control electronics. It also describes the two main imaging modes of constant current and constant height. Common applications and examples of STM images showing atomic structures are also presented. Finally, related microscopy techniques developed from STM principles are briefly discussed.
This document discusses several topics related to steady electric currents:
- It defines different types of electric currents including conduction, electrolytic, convection, and displacement currents.
- It introduces current density and derives Ohm's law, relating current density to electric field and conductivity.
- It describes electromotive force (EMF) as the driving force provided by sources like batteries to maintain steady current in closed circuits, as stated by Kirchhoff's voltage law.
- It introduces the continuity equation relating divergence of current density to charge density changes, and derives Kirchhoff's current law equating the sum of currents at junctions to zero.
1) Charles Flynn developed a magnetic frame device that uses coils wound around an iron frame containing a powerful permanent magnet. Applying pulses to the coils can produce linear or circular motion without moving parts.
2) Lawrence Tseung created a similar magnetic frame device that inserts a permanent magnet into one arm. Applying sharp DC pulses to a coil on one side can produce over-unity output power from a coil on the other side if the pulses reinforce the magnet's field.
3) Thane Heins developed a figure-eight double toroid transformer that can produce over 30 times the input power. The unique magnetic flow paths allow most reverse magnetic flux to cancel out, greatly improving efficiency over standard transformers.
This document provides a summary of key developments in the foundations of quantum mechanics. It discusses Planck's discovery that led to defining Planck's constant h, which established that energy is quantized. Einstein's work on the photoelectric effect supported this and introduced the photon concept. Bohr used classical mechanics and energy quantization to develop his model of the hydrogen atom. The document outlines the revolutionary changes brought by quantum theory and its greater scope and applicability compared to classical physics. It provides context for understanding quantum mechanics from first principles.
Assignment 3 (CH. 7-9)
Chapter 7
Questions (use complete sentences)
1) What is an electric field? Sketch the shape of the electric field around a single proton.
2) If a uniform electric field is pointing east, what is the direction of the force on an electron? What is the direction of force on a positive particle?
3) If electrons are flowing counter clock wise in a circuit, which way is the conventional current flowing?
4) Explain what current, voltage, and resistance are?
5) Describe the differences between circuits with resistors connected in series vs. parallel.
Problems (show your work)
1) Two charged particles exert an electrical force of 16 N on each other. What will the magnitude of the force be if the distance between them is reduced by half? What if the distance is doubled?
2) What would the separation between two particles each with a charge of 1 C have to be so that they each feel a force of 1 N.
3) A particle with a charge of 2.0 x 10-6 C experiences an upward force of 8N. What is the magnitude and direction of the electric field at that point? What if the charge was negative?
4) During 30 second of use, 250 C of charge flow through a microwave over. What is the current?
5) A current of 12 A flows through an electric heater operating on 120 V. What is the heater’s resistance?
6) The resistance of each brake light on an automobile is 6.6 Ω. Use the fact that cars have 12 V electrical systems to calculate the current that flows through each bulb.
7) An electric eel can generate a 400 V, 0.5 A shock for stunning its prey. What is the eel’s power output?
8) A clock consumes 2 W of electrical power. How much energy does it use each day?
Challenge (show work)
1) Three particles each with a charge of 2.5 x 10-6 C are located on the x-axis. There coordinates are (0,0), (2,0), and (6,0). What is the magnitude and direction of the electrical force on the particle located at (2,0)?
Chapter 8
Questions (use complete sentences)
1) Sketch the shape of the magnetic field around a bar magnet.
2) List the main type of electromagnetic waves in order of increasing frequency.
3) How does the radiation emitted by a black body change as its temperature increases?
4) What does a transformer do?
5) What are the three observations of magnetism talked about in class?
Problems (show work)
1) A cell phone charger is a transformer that reduces 120 V to 5V. For each 1,000 turns in the input coil, how many turns are there in the output coil?
2) What is the wavelength of a 60,000 Hz radio wave?
3) A transformer has an input coil of 2,000 turns, and an output coil of 500 turns. If 120 V is connected to the input coil how much voltage will it output?
4) Compute the frequency of an EM wave with a wavelength of 0.0542 m.
5) How much more energy would a black body radiate at 900 K vs 300 K?
6) What wavelength of light do humans mostly radiate if the human body temperature is 310 K?
Chapter 9
Questions (use complete sentences)
1) .
The document summarizes research on generating and observing stable vortex lattices in polariton condensates in semiconductor microcavities. Researchers pumped three spots in a triangular geometry and observed the formation of a honeycomb lattice containing up to 100 vortices and antivortices extending over tens of microns. Numerical simulations matched the experimental observations and showed the lattice forms due to ferromagnetic coupling between the condensates at each pumped spot, with the phase locked by the imposed triangular geometry. The vortex lattice was stable for many minutes and highly sensitive to the optically imposed geometry.
This document describes the course EEE 2207: Electrical Machines 1. The course covers various electrical machines including DC generators and motors, transformers, induction motors, synchronous generators and motors. It provides details on the operating principles, construction, characteristics and testing of these machines. The document also outlines the syllabus, evaluation criteria, textbooks and reference books for the course. Key topics to be covered include armature reactions, speed control methods, transformer circuits and performance, induction motor equivalent circuits, and synchronous generator and motor operation.
The document discusses the concept of electromagnetic induction. It begins by defining key terms like magnetic flux and explaining Faraday's experiments which demonstrated that a changing magnetic field can induce an electromotive force (emf) in a circuit. It then states Faraday's Law of electromagnetic induction, which says that a changing magnetic flux induces an emf. It also explains Lenz's Law, which describes the direction of the induced current. The document provides expressions for calculating the induced emf and current. It discusses different methods of inducing emf, like changing the magnetic field or area of a coil. It also covers related topics like eddy currents, self-induction, and mutual induction.
This document provides an overview of synchronous machines, covering their structure, operation principles, and performance characteristics. Key points include:
1) Synchronous machines have rotors that rotate at a speed proportional to the excitation frequency, allowing them to operate as generators or motors for constant speed applications.
2) They have distributed stator windings that generate a rotating magnetic field when powered by balanced three-phase currents. The rotor rotates in sync with this field at the synchronous speed.
3) Rotor structures include round and salient pole designs. Generators use rotating magnetic fields to induce three-phase voltages, while motors use supplied voltages to drive the rotor via magnetic drag.
1) An inductor opposes changes in current through self-induction, generating a counter-EMF when current increases or decreases. This causes the current in an AC inductive circuit to lag 90 degrees behind the voltage.
2) Inductive reactance represents an inductor's opposition to AC current, and increases with frequency and inductance. It can be calculated using XL=2πfL.
3) A purely inductive AC circuit does not consume any power on average, as energy stored in the magnetic field during one half of the cycle is returned during the other half.
Algorithm to Generate Wavelet Transform from an Orthogonal TransformCSCJournals
This paper proposes algorithm to generate discrete wavelet transform from any orthogonal transform. The wavelet analysis procedure is to adopt a wavelet prototype function, called an analyzing wave or mother wave. Other wavelets are produced by translation and contraction of the mother wave. By contraction and translation infinite set of functions can be generated. This set of functions must be orthogonal and this condition qualifies a transform to be a wavelet transform. Thus there are only few functions which satisfy this condition of orthogonality. To simplify this situation, this paper proposes a generalized algorithm to generate discrete wavelet transform from any orthogonal transform. For an NxN orthogonal transform matrix T, element of each row of T is repeated N times to generate N Mother waves. Thus rows of original transform matrix become wavelets. As an example we have illustrated the procedure of generating Walsh wavelet called ‘Walshlet’ from Walsh transform. Since data compression is one of the best applications of wavelets, we have implemented image compression using Walsh as well as Walshlet. Our experimental results show that performance of image compression technique using Walshlet is much better than that of standard Walsh transform. More over image reconstructed from Walsh transform has some blocking artifact, which is not present in the image reconstructed from Walshlet. Similarly image compression using DCT and DCT Wavelet has been implemented. Again the results of DCT Wavelet have been proved to perform better than normal DCT
Transformers transfer electrical energy between two circuits through electromagnetic induction. A varying current in the primary winding produces a varying magnetic field that induces a voltage in the secondary winding. Transformers are used to increase or decrease alternating voltages for power transmission and utilization. They work on Faraday's law of induction and have no moving parts. A transformer consists of primary and secondary coils wound around a laminated iron core to maximize flux linkage between the coils.
This paper was published by my former Supervisor and involves partly my calculations and the concepts used during my MSci Thesis at University College London.
Research on Transformer Core Vibration under DC Bias Based on Multi-field Cou...inventionjournals
The Mathematical models for DC bias vibration analysis of the transformer core are developed in this paper. The model is combined into multi-physical field coupling modeling for vibration analysis of the transformer. By applying the primary voltage as excitation and under different DC bias, vibrations of the transformer core is simulated and analyzed.
Faraday's laws of electromagnetic induction describe how a changing magnetic field can induce an electromotive force (EMF) in a conductor. This is the operating principle behind electric generators and transformers. The document discusses Faraday's experiments demonstrating electromagnetic induction, his laws, self and mutual inductance, generation of sinusoidal voltages, phasor representation, and introduction to three-phase systems and electric grids. Key points covered include Faraday's law of induction, the relationship between induced EMF and rate of change of magnetic flux, how inductance opposes changes in current, and generation of sinusoidal AC voltages through rotating coils in magnetic fields.
Literature survey modeling of microfluidics devicesAweshkumarsingh
This presentation discusses modeling of microfluidics devices. It begins with definitions of electrokinetics phenomena like electroosmosis, electrophoresis, and dielectrophoresis that are important in microfluidics. It then discusses various modeling approaches like continuum models using Navier-Stokes equations, molecular dynamics simulations, DSMC, and lattice Boltzmann methods. Examples of applying these methods to study phenomena like mixing and particle separation in microchannels are provided.
Electromagnetic induction is the process of using magnetic fields to produce voltage and current in a conductor. Michael Faraday discovered that a changing magnetic flux induces a voltage in any nearby conductor. This effect is known as electromagnetic induction. Lenz's law describes how the direction of induced current is always such that it creates a magnetic field opposing the original change in magnetic flux that caused it. Motional emf is a type of electromagnetic induction that occurs when a conductor moves through a magnetic field, such as in electric generators, transformers, electric motors, and railguns.
The document presents a technique called Resonance Mode Analysis for investigating harmonic resonance in power systems. It finds that harmonic resonance is related to the singularity of the network admittance matrix, which occurs when one of the matrix's eigenvalues approaches zero. This zero eigenvalue defines the critical resonance mode. The analysis of harmonic resonance can thus be transformed into studying these critical modes through modal analysis. The technique provides useful information on the nature and extent of resonance by analyzing the characteristics of the critical eigenvalues and eigenvectors.
What Is The Importance Of Research Paper Writing Service - UK CustLaura Benitez
The document provides instructions for using a research paper writing service called HelpWriting.net. It outlines a 5-step process: 1) Create an account with an email and password. 2) Complete an order form with instructions, sources, and deadline. 3) Review bids from writers and choose one. 4) Review the paper and authorize payment or request revisions. 5) Request multiple revisions to ensure satisfaction, with a full refund option for plagiarism. The service aims to provide original, high-quality content meeting customers' needs.
Apple Writing Template Writing Templates, TeacheLaura Benitez
The document discusses lipid-based drug delivery systems. It notes that lipid carriers like oils, emulsions, and liposomes are commonly used to incorporate poorly water-soluble drugs to improve their bioavailability. The key mechanism is avoiding a slow dissolution process. Both the lipid composition and any surfactants used can impact how the formulation interacts with the gastrointestinal tract and affects drug absorption. While lipid formulations show promise, more data is still needed on the complex physics of lipids and issues like drug stability. The interaction of the formulation with the GI tract and its effect on absorption is also important to understand.
1. DC motors operate by converting electrical energy from a power source into mechanical energy. They consist of a stationary stator and a rotating rotor made of coils that interact with magnetic fields.
2. DC motors are classified as either separately excited, shunt, or series motors depending on how their field and armature windings are electrically connected. Separately excited motors have independent field and armature circuits while shunt and series motors have their field windings connected in parallel or series to the armature winding, respectively.
3. In a DC motor, torque is produced by the interaction between current in the rotor coils and the magnetic field from the stator. As the rotor rotates, a counter-voltage or
This document provides information about a scanning tunneling microscope (STM) including its basic operating principles, design, modes of operation, applications, and related imaging techniques. The STM works by using the quantum tunneling effect to measure electric currents between a sharp tip and conductive sample surface. This allows it to image surfaces at the atomic level with high resolution. The document outlines the key components of an STM including the sample, scanning tip, piezoelectric scanner, and control electronics. It also describes the two main imaging modes of constant current and constant height. Common applications and examples of STM images showing atomic structures are also presented. Finally, related microscopy techniques developed from STM principles are briefly discussed.
This document discusses several topics related to steady electric currents:
- It defines different types of electric currents including conduction, electrolytic, convection, and displacement currents.
- It introduces current density and derives Ohm's law, relating current density to electric field and conductivity.
- It describes electromotive force (EMF) as the driving force provided by sources like batteries to maintain steady current in closed circuits, as stated by Kirchhoff's voltage law.
- It introduces the continuity equation relating divergence of current density to charge density changes, and derives Kirchhoff's current law equating the sum of currents at junctions to zero.
1) Charles Flynn developed a magnetic frame device that uses coils wound around an iron frame containing a powerful permanent magnet. Applying pulses to the coils can produce linear or circular motion without moving parts.
2) Lawrence Tseung created a similar magnetic frame device that inserts a permanent magnet into one arm. Applying sharp DC pulses to a coil on one side can produce over-unity output power from a coil on the other side if the pulses reinforce the magnet's field.
3) Thane Heins developed a figure-eight double toroid transformer that can produce over 30 times the input power. The unique magnetic flow paths allow most reverse magnetic flux to cancel out, greatly improving efficiency over standard transformers.
This document provides a summary of key developments in the foundations of quantum mechanics. It discusses Planck's discovery that led to defining Planck's constant h, which established that energy is quantized. Einstein's work on the photoelectric effect supported this and introduced the photon concept. Bohr used classical mechanics and energy quantization to develop his model of the hydrogen atom. The document outlines the revolutionary changes brought by quantum theory and its greater scope and applicability compared to classical physics. It provides context for understanding quantum mechanics from first principles.
Assignment 3 (CH. 7-9)
Chapter 7
Questions (use complete sentences)
1) What is an electric field? Sketch the shape of the electric field around a single proton.
2) If a uniform electric field is pointing east, what is the direction of the force on an electron? What is the direction of force on a positive particle?
3) If electrons are flowing counter clock wise in a circuit, which way is the conventional current flowing?
4) Explain what current, voltage, and resistance are?
5) Describe the differences between circuits with resistors connected in series vs. parallel.
Problems (show your work)
1) Two charged particles exert an electrical force of 16 N on each other. What will the magnitude of the force be if the distance between them is reduced by half? What if the distance is doubled?
2) What would the separation between two particles each with a charge of 1 C have to be so that they each feel a force of 1 N.
3) A particle with a charge of 2.0 x 10-6 C experiences an upward force of 8N. What is the magnitude and direction of the electric field at that point? What if the charge was negative?
4) During 30 second of use, 250 C of charge flow through a microwave over. What is the current?
5) A current of 12 A flows through an electric heater operating on 120 V. What is the heater’s resistance?
6) The resistance of each brake light on an automobile is 6.6 Ω. Use the fact that cars have 12 V electrical systems to calculate the current that flows through each bulb.
7) An electric eel can generate a 400 V, 0.5 A shock for stunning its prey. What is the eel’s power output?
8) A clock consumes 2 W of electrical power. How much energy does it use each day?
Challenge (show work)
1) Three particles each with a charge of 2.5 x 10-6 C are located on the x-axis. There coordinates are (0,0), (2,0), and (6,0). What is the magnitude and direction of the electrical force on the particle located at (2,0)?
Chapter 8
Questions (use complete sentences)
1) Sketch the shape of the magnetic field around a bar magnet.
2) List the main type of electromagnetic waves in order of increasing frequency.
3) How does the radiation emitted by a black body change as its temperature increases?
4) What does a transformer do?
5) What are the three observations of magnetism talked about in class?
Problems (show work)
1) A cell phone charger is a transformer that reduces 120 V to 5V. For each 1,000 turns in the input coil, how many turns are there in the output coil?
2) What is the wavelength of a 60,000 Hz radio wave?
3) A transformer has an input coil of 2,000 turns, and an output coil of 500 turns. If 120 V is connected to the input coil how much voltage will it output?
4) Compute the frequency of an EM wave with a wavelength of 0.0542 m.
5) How much more energy would a black body radiate at 900 K vs 300 K?
6) What wavelength of light do humans mostly radiate if the human body temperature is 310 K?
Chapter 9
Questions (use complete sentences)
1) .
The document summarizes research on generating and observing stable vortex lattices in polariton condensates in semiconductor microcavities. Researchers pumped three spots in a triangular geometry and observed the formation of a honeycomb lattice containing up to 100 vortices and antivortices extending over tens of microns. Numerical simulations matched the experimental observations and showed the lattice forms due to ferromagnetic coupling between the condensates at each pumped spot, with the phase locked by the imposed triangular geometry. The vortex lattice was stable for many minutes and highly sensitive to the optically imposed geometry.
This document describes the course EEE 2207: Electrical Machines 1. The course covers various electrical machines including DC generators and motors, transformers, induction motors, synchronous generators and motors. It provides details on the operating principles, construction, characteristics and testing of these machines. The document also outlines the syllabus, evaluation criteria, textbooks and reference books for the course. Key topics to be covered include armature reactions, speed control methods, transformer circuits and performance, induction motor equivalent circuits, and synchronous generator and motor operation.
The document discusses the concept of electromagnetic induction. It begins by defining key terms like magnetic flux and explaining Faraday's experiments which demonstrated that a changing magnetic field can induce an electromotive force (emf) in a circuit. It then states Faraday's Law of electromagnetic induction, which says that a changing magnetic flux induces an emf. It also explains Lenz's Law, which describes the direction of the induced current. The document provides expressions for calculating the induced emf and current. It discusses different methods of inducing emf, like changing the magnetic field or area of a coil. It also covers related topics like eddy currents, self-induction, and mutual induction.
This document provides an overview of synchronous machines, covering their structure, operation principles, and performance characteristics. Key points include:
1) Synchronous machines have rotors that rotate at a speed proportional to the excitation frequency, allowing them to operate as generators or motors for constant speed applications.
2) They have distributed stator windings that generate a rotating magnetic field when powered by balanced three-phase currents. The rotor rotates in sync with this field at the synchronous speed.
3) Rotor structures include round and salient pole designs. Generators use rotating magnetic fields to induce three-phase voltages, while motors use supplied voltages to drive the rotor via magnetic drag.
1) An inductor opposes changes in current through self-induction, generating a counter-EMF when current increases or decreases. This causes the current in an AC inductive circuit to lag 90 degrees behind the voltage.
2) Inductive reactance represents an inductor's opposition to AC current, and increases with frequency and inductance. It can be calculated using XL=2πfL.
3) A purely inductive AC circuit does not consume any power on average, as energy stored in the magnetic field during one half of the cycle is returned during the other half.
Algorithm to Generate Wavelet Transform from an Orthogonal TransformCSCJournals
This paper proposes algorithm to generate discrete wavelet transform from any orthogonal transform. The wavelet analysis procedure is to adopt a wavelet prototype function, called an analyzing wave or mother wave. Other wavelets are produced by translation and contraction of the mother wave. By contraction and translation infinite set of functions can be generated. This set of functions must be orthogonal and this condition qualifies a transform to be a wavelet transform. Thus there are only few functions which satisfy this condition of orthogonality. To simplify this situation, this paper proposes a generalized algorithm to generate discrete wavelet transform from any orthogonal transform. For an NxN orthogonal transform matrix T, element of each row of T is repeated N times to generate N Mother waves. Thus rows of original transform matrix become wavelets. As an example we have illustrated the procedure of generating Walsh wavelet called ‘Walshlet’ from Walsh transform. Since data compression is one of the best applications of wavelets, we have implemented image compression using Walsh as well as Walshlet. Our experimental results show that performance of image compression technique using Walshlet is much better than that of standard Walsh transform. More over image reconstructed from Walsh transform has some blocking artifact, which is not present in the image reconstructed from Walshlet. Similarly image compression using DCT and DCT Wavelet has been implemented. Again the results of DCT Wavelet have been proved to perform better than normal DCT
Transformers transfer electrical energy between two circuits through electromagnetic induction. A varying current in the primary winding produces a varying magnetic field that induces a voltage in the secondary winding. Transformers are used to increase or decrease alternating voltages for power transmission and utilization. They work on Faraday's law of induction and have no moving parts. A transformer consists of primary and secondary coils wound around a laminated iron core to maximize flux linkage between the coils.
This paper was published by my former Supervisor and involves partly my calculations and the concepts used during my MSci Thesis at University College London.
Research on Transformer Core Vibration under DC Bias Based on Multi-field Cou...inventionjournals
The Mathematical models for DC bias vibration analysis of the transformer core are developed in this paper. The model is combined into multi-physical field coupling modeling for vibration analysis of the transformer. By applying the primary voltage as excitation and under different DC bias, vibrations of the transformer core is simulated and analyzed.
Faraday's laws of electromagnetic induction describe how a changing magnetic field can induce an electromotive force (EMF) in a conductor. This is the operating principle behind electric generators and transformers. The document discusses Faraday's experiments demonstrating electromagnetic induction, his laws, self and mutual inductance, generation of sinusoidal voltages, phasor representation, and introduction to three-phase systems and electric grids. Key points covered include Faraday's law of induction, the relationship between induced EMF and rate of change of magnetic flux, how inductance opposes changes in current, and generation of sinusoidal AC voltages through rotating coils in magnetic fields.
Literature survey modeling of microfluidics devicesAweshkumarsingh
This presentation discusses modeling of microfluidics devices. It begins with definitions of electrokinetics phenomena like electroosmosis, electrophoresis, and dielectrophoresis that are important in microfluidics. It then discusses various modeling approaches like continuum models using Navier-Stokes equations, molecular dynamics simulations, DSMC, and lattice Boltzmann methods. Examples of applying these methods to study phenomena like mixing and particle separation in microchannels are provided.
Electromagnetic induction is the process of using magnetic fields to produce voltage and current in a conductor. Michael Faraday discovered that a changing magnetic flux induces a voltage in any nearby conductor. This effect is known as electromagnetic induction. Lenz's law describes how the direction of induced current is always such that it creates a magnetic field opposing the original change in magnetic flux that caused it. Motional emf is a type of electromagnetic induction that occurs when a conductor moves through a magnetic field, such as in electric generators, transformers, electric motors, and railguns.
The document presents a technique called Resonance Mode Analysis for investigating harmonic resonance in power systems. It finds that harmonic resonance is related to the singularity of the network admittance matrix, which occurs when one of the matrix's eigenvalues approaches zero. This zero eigenvalue defines the critical resonance mode. The analysis of harmonic resonance can thus be transformed into studying these critical modes through modal analysis. The technique provides useful information on the nature and extent of resonance by analyzing the characteristics of the critical eigenvalues and eigenvectors.
What Is The Importance Of Research Paper Writing Service - UK CustLaura Benitez
The document provides instructions for using a research paper writing service called HelpWriting.net. It outlines a 5-step process: 1) Create an account with an email and password. 2) Complete an order form with instructions, sources, and deadline. 3) Review bids from writers and choose one. 4) Review the paper and authorize payment or request revisions. 5) Request multiple revisions to ensure satisfaction, with a full refund option for plagiarism. The service aims to provide original, high-quality content meeting customers' needs.
Apple Writing Template Writing Templates, TeacheLaura Benitez
The document discusses lipid-based drug delivery systems. It notes that lipid carriers like oils, emulsions, and liposomes are commonly used to incorporate poorly water-soluble drugs to improve their bioavailability. The key mechanism is avoiding a slow dissolution process. Both the lipid composition and any surfactants used can impact how the formulation interacts with the gastrointestinal tract and affects drug absorption. While lipid formulations show promise, more data is still needed on the complex physics of lipids and issues like drug stability. The interaction of the formulation with the GI tract and its effect on absorption is also important to understand.
The passage discusses the obstacles to economic development in Pakistan. Some of the key economic obstacles mentioned include inadequacy of natural resources, low savings rates which hinders capital formation, and unfavorable economic institutions like banks and the stock market. Social obstacles include high population growth which increases dependency. Cultural obstacles involve traditional social values and practices that hamper development. Administrative obstacles pertain to ineffective government policies and bureaucracy. Political instability is also cited as an obstacle.
Here are the key points about Jefferson Davis' life:
- He was born in 1808 in Kentucky but raised in Mississippi. He was the youngest of 10 children.
- He attended Transylvania University and West Point, graduating from West Point in 1828.
- He served as the Secretary of War from 1853-1857 under President Franklin Pierce.
- He was a U.S. Senator from Mississippi from 1847-1861.
- In 1861, he became the President of the Confederate States of America, leading the South during the Civil War.
- After the Civil War ended in 1865, he was imprisoned for two years but was never tried for treason.
- He later
School Essay How To Write An Essay IntroLaura Benitez
The document provides instructions for creating an account and submitting assignment requests on the HelpWriting.net website. It outlines a 5-step process: 1) Create an account with a password and email; 2) Complete an order form with instructions, sources, and deadline; 3) Review writer bids and choose one based on qualifications; 4) Review the completed paper and authorize payment; 5) Request revisions until satisfied. The document promotes HelpWriting.net's writing services and guarantees of original, high-quality work or a full refund.
How Do You Write A Book Review. How To Write A BooLaura Benitez
The document provides instructions for requesting writing assistance from HelpWriting.net. It outlines a 5-step process: 1) Create an account with a password and email. 2) Complete a 10-minute order form with instructions, sources, and deadline. 3) Review bids from writers and choose one. 4) Receive the paper and authorize payment if pleased. 5) Request revisions until fully satisfied, with a refund option for plagiarism. The process aims to match clients with qualified writers to meet their needs through various writing services.
Common App Transfer Essay Help Best Common App TrLaura Benitez
The document discusses steps to get writing assistance from HelpWriting.net, including creating an account, completing an order form with instructions and deadline, and reviewing writer bids before selecting one and placing a deposit to start the assignment. It also notes that customers can request revisions until satisfied with the final paper and will receive a full refund if the paper is plagiarized.
The document provides instructions for requesting a paper writing service from HelpWriting.net. It outlines 5 steps: 1) Create an account with valid email and password. 2) Complete a 10-minute order form providing instructions, sources, and deadline. 3) Review bids from writers and choose one based on qualifications. 4) Review the completed paper and authorize payment if satisfied. 5) Request revisions to ensure satisfaction, with a refund option for plagiarized work. The service aims to provide original, high-quality content through a bidding system and revision process.
1. The essay analyzes two poems, Natalie Meyers' "Hidden Heart" and Astophil's "Astohpil and Stella", that both deal with the difficulty of expressing emotions through words and the realization that writing from the heart is needed.
2. Both poets struggle to find the right words to convey their feelings and are inhibited by overanalyzing their writing.
3. However, they eventually break through this frustration by tapping into their emotions and allowing their true voice to shine through.
Custom Personalized Writing Paper Set Letter WritingLaura Benitez
The document provides instructions for identifying an unknown bacteria sample using various tests and techniques. It begins by describing streaking the bacteria onto an agar plate for potential future use and performing a Gram stain test. The Gram stain results indicated the bacteria was gram-positive and formed small, round clusters, pointing to it being a coccus. No issues arose during the Gram stain test, which produced a clearly dark purple result. Further tests described on HelpWriting.net were to be used to fully identify the unknown bacteria.
Persuasive Writing Anchor Chart - Google Search TeLaura Benitez
The document summarizes the key steps to request and receive help with an assignment from the website HelpWriting.net. It outlines registering for an account, completing an order form with instructions and deadlines, reviewing bids from writers and selecting one, placing a deposit to start the work, and reviewing and authorizing payment for the completed assignment. It notes that free revisions are provided and plagiarized work will result in a full refund.
The document discusses the Enlightenment and its relationship to the earlier Scientific Revolution. It notes that the Scientific Revolution led to new scientific discoveries that challenged existing beliefs and made people question political and social orders. This led to the Enlightenment, which challenged traditional hierarchical ideals and emphasized reason, science, and individualism over tradition and religion. Key thinkers of the Enlightenment promoted ideas like natural rights, tolerance, and separation of church and state.
Neil Armstrong was an American astronaut and the first person to walk on the moon. He demonstrated humility as a military pilot in the Korean War and as the first man on the moon. Armstrong showed great courage and strength in his 78 combat missions in Korea and as commander of the Apollo 11 mission to land on the moon. As the first person to step foot on the moon, Armstrong achieved national hero status for his role in America's victory in the Space Race against the Soviet Union.
The document discusses argumentative writing skills and the process for getting writing help from the HelpWriting.net website. It involves 5 steps: 1) Creating an account, 2) Completing an order form with instructions and deadline, 3) Reviewing bids from writers and choosing one, 4) Reviewing the completed paper and authorizing payment, 5) Requesting revisions if needed and being ensured of original, high-quality content.
Essay Review Popular Music Cambridge CoreLaura Benitez
This document provides instructions for requesting essay writing help from HelpWriting.net. It outlines a 5-step process: 1) Create an account with a password and email. 2) Complete a 10-minute order form providing instructions, sources, and deadline. 3) Review bids from writers and choose one based on qualifications. 4) Review the completed paper and authorize payment if satisfied. 5) Request revisions to ensure satisfaction, with a full refund option for plagiarized work. The process aims to match requests with qualified writers and provide original, high-quality content through revisions.
The document provides instructions for creating an essay outline on the website HelpWriting.net in 5 steps: 1) Create an account; 2) Complete a 10-minute order form providing instructions, sources, and deadline; 3) Review writer bids and choose one to complete the assignment; 4) Review the completed paper and authorize payment; 5) Request revisions to ensure satisfaction and receive a refund if plagiarized.
Critique Paper Example Short Story How To WriteLaura Benitez
Emile Durkheim analyzed different types of suicide in his book On Suicide. He distinguished between egoistic suicide, which occurs when individuals are insufficiently integrated into society, and altruistic suicide, which happens among tightly-knit groups when members are willing to die defending the group. Durkheim believed sociology should be a distinct science that studies social facts existing independently of individuals. His methodology focused on how social forces influence individuals and behavior.
Pay Someone To Write My College Essay AssignmentstoreLaura Benitez
The document provides instructions for requesting an essay writing service from Assignmentstore. It outlines a 5-step process: 1) Create an account, 2) Complete an order form providing instructions, sources, and deadline, 3) Review bids from writers and select one, 4) Review the completed paper and authorize payment, 5) Request revisions if needed, with the service offering refunds for plagiarized work. The service aims to match customers with qualified writers to complete assignments through an online bidding system.
The document provides instructions for writing a college narrative essay in 5 steps:
1. Create an account on the website to request a paper be written.
2. Complete an order form providing instructions, sources, and deadline for the paper.
3. Writers will bid on the request and the customer can select a writer.
4. The customer will receive the paper and can request revisions if needed.
5. Customers can request multiple revisions to ensure satisfaction with the completed paper.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
1. Essay On Induced Emf
Contents Introduction 2 Aims and Objectives 2 Generator design 3 1) Explain briefly how the
circular motion of a rotor with permanent magnets generates an induced EMF in a stator winding
and how it generates voltage during rotation 4 2) Use a time–dependent 2D study by COMSOL
Multiphysics in order to model a generator. 5 3) Sketch the distribution of magnetic flux density at t
= 0.0, 0.05, 0.1, 0.15, 0.20 and 0.25 7 4) Sketch the contours of magnetic vector potential on the
same graph at t = 0.0, 0.05, 0.1, 0.15, 0.2 and 0.25 11 4) Sketch the distribution of energy density at
t = 0.0, 0.05, 0.1, 0.15, 0.20 and 0.25. Which part contains higher concentration of energy? 15 15 5)
Sketch the graph of induced EMF for rotor speed of 1rpm 20 6) What is the peak and RMS value of
the induced EMF 21 7) Induced EMF at 2rpm 22 Results: 23 References: 24 Appendix 25 A)
Contours at t= 0.0, 0.05, 0.1, 0.15, 0.20, and 0.25: 25 B) contour magnetic potential at 0.2s 28
Introduction The main aim if this report is the investigation of a permanent magnet AC generator. It
is required to construct the generator in COMSOL Multiphysics and understand the generator's
working. The report will also give an understanding of the working of a permanent magnet rotor that
generates an induced EMF in stator winding and how it generates voltage during rotation. The data
concluded in this report is all collected by using a time dependent 2D study by COMSOL
Multiphysics and is to be used to understand
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2.
3. Advantages And Disadvantages Of Pervaporation
Observed first in 1919 by P.A. Kober, pervaporation, as the name delineates, incorporates
permeation of a component into the involved membrane matrix and the successive evaporation of
the permeated component into the vapour phase inside the membrane matrix. The vapour–liquid
interface is extant inside the membrane. The component from the liquid feed that permeates into the
membrane vaporizes into its corresponding vapour state in situ and gets selectively permeated to the
other side which depends on the difference between the transport rates of the components in the
liquid feed. Generally, the feed or the upstream side is at atmospheric pressure, while the permeate
or the downstream side is kept under vacuum so as to allow the selective evaporation of the target
component after permeation through the membrane (der Bruggen et al., 2015). The driving force is
the differences in partial pressures of the components on either side of the membrane. A thing of
note: the volatility difference between the feed components does not play any role whatsoever in
determining the selectivity of the components (Huang et al., 2008). The mechanism involved in
pervaporation is the solution–diffusion model.
Pervaporation membranes can be classified depending on the material used for their construction i.e
organic, inorganic and ... Show more content on Helpwriting.net ...
The PDMS, PTMSP, zeolite and composite membranes have been reported to have separation
factors of 4.4–10.8, 9–26, 7–59, 12–106, respectively. However, in some cases, the separation factor
gets way higher than expected, such as a separation factor of 218 during the separation of ethanol
(98.2% permeate) over water–ethanol solution (20% by weight ethanol), using a silicate zeolite
membrane (Nomura et al., 2002). In general, separation factors are ranked in the following order:
PDMS < PTMSP < composite membranes < zeolite
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4.
5. Flux And Fascism
Pirandellan Flux and Fascism In 1935 – the year before he died – the great Italian playwright Luigi
Pirandello donated all of the gold in his possession to the fascist government in support of the
Ethiopian campaign. Included in this collection was his 1934 Noble Prize medal (cite). He had been
a member of the fascist party since 1924. He had joined shortly after the murder by fascist agents of
a socialist deputy named Giacomo Matteotti (Argenteri, 129). Many intellectuals had left the party
thereafter, disgusted with the violent tactics of the budding fascist regime. Attempts have been made
– starting with Gaspare Guidice's 1963 biography – to separate Pirandello's work from his politics.
But is it possible that an author's work can be completely ... Show more content on Helpwriting.net
...
Zeev Sternhell, have proposed the origins of fascism as a cultural or intellectual movement
beginning in early 20th century France and Italy (cite). Does Pirandello's claim of partial intellectual
ownership give creed to this theory? Certainly his flirtation with and later marriage (a metaphor
used by Letizia Argenteri in her paper Pirandello and Fascism) to fascism seems to be more of an
ideological than political affair. His early identification of Mussolini with his central philosophy of
life and form justified his dedication to the strong leader, though he'd later disparage the distinctly
fascist cult of personality. "Around him," Pirandello complains to Marta Abba, "there must be a
level of heads that can barely reach his knee, not one inch more" (Argenteri 134). We also see
Pirandello speak – through a drunken character in one of his earlier novels – on his distrust in
democracy in relation to the dictator. Democracy, after all, had failed to prevent the Great War
which had so affected the Italian consciousness. Perhaps the Italians would do better under a united
regime. "When you have one boss, he knows that it's his job to satisfy many people; but when
everybody has a say in running things, everybody thinks of satisfying himself" (Late Mattia Pascal).
Another interpretation of Six Characters presents the
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6.
7. Maxwell's Equation Essay
INTRODUCTION
Maxwell's Equations are a set of four mathematical equations that provides the foundation to the
largely abstract concepts of electricity and magnetism. They are a mathematical condensation of all
the basic rules, by which electricity and magnetism function. Refer to Figure 1 for the equations.
Although James Clerk Maxwell himself only contributed to the last equation, his contribution led to
one of the most important discoveries in the history of science. However, it wasn't until 25 years
later that these equations were interpreted and used rightly by the rest of the world. On the right is
an image of Maxwell.
Maxwell's work as quoted by Einstein:
'The formulation of Maxwell's equations is the most important event in physics since Newton's time,
not only because of their wealth of content, but also because they form a pattern for a new type of
law ... ... Show more content on Helpwriting.net ...
The equation is actually incomplete, and valid only for a long straight wire. An example to prove
that it's incomplete is given below.
Suppose a pot is taken and the exterior surface is considered the enclosed surface mentioned in the
law, and the circumference of the bottom is considered to be the closed curve. When the equation
uses the term 'i', it actually means the current enclosed within the path, piercing through the surface.
If the pot were shaped in such a way that the wire carrying current ended inside the pot after
piercing through and coming out, current enclosed would be 0. This either means that dl and the
magnetic field are always perpendicular (cosine 90 = 0), or that the magnetic field itself is 0. Both
are impossible and there lies the contradiction.
MAXWELL'S CORRECTION
Maxwell corrected the equation by adding another term to it. Considering the above example, there
is a change in electric field as the current pierces through one surface of the pot and goes out
through the other. This field can be expresses
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8.
9. Conventional Method And Space Vector Pulse Width...
Direct Torque Control of Induction Motor Simulation using Conventional Method And Space Vector
Pulse Width Modulation Naveen Chander PG Student Electrical Engineering NITTTR Chandigarh,
India snl.naveen@gmail.com Dr. S. Chatterji Professor & Head Electrical Engineering NITTTR
Chandigarh, India Dr. Lini Mathew Associate Professor Electrical Engineering NITTTR
Chandigarh, India Abstract–This paper proposes direct torque control of induction motor simulation
using conventional method and space vector pulse width modulation technique for ripple reduction.
Direct Torque Control (DTC) is a control technique used in AC drive systems to obtain high
performance torque control and thereby controlling the speed of induction motor. The ... Show more
content on Helpwriting.net ...
Hence the scheme proves itself superior to the DC machine. The problem faced by FOC scheme is
complexity in its implementation due to dependence of machine parameters, reference frame
transformation. Later DTC was introduced. Direct torque control (DTC) method is used to control
the torque (finally speed) in variable frequency drives of three–phase AC electric motors. From the
measured voltage and current of the motor an estimate of the motor 's magnetic flux and torque is
calculated. Integrating the stator voltages, stator flux linkage is estimated. Cross product of
measured motor current vector and estimated stator flux linkage vector results in estimated torque.
The estimated flux magnitude and torque are then compared with their reference values. If either the
estimated flux or torque deviates from the reference more than allowed limits, the transistors of the
variable frequency drive are turned OFF and ON in such a way that the flux and torque errors will
return in their tolerant bands as fast as possible. Thus direct torque control is one form of the
hysteresis control. The method requires only the stator resistance to estimate the stator flux and
torque. The basic DTC scheme [1] consists of two comparators with specified bandwidth, switching
table, voltage source inverter, flux and torque estimation block. Like every control method has some
advantages and disadvantages, DTC method has too. Some of the advantages are lower parameters
dependency, making
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10.
11. The Strength Of An Induced Magnetic Field
Magnet Drop
Introduction
Throughout this report the strength of an induced magnetic field will be explored, this will be
achieved through dropping a rare earth magnet through an aluminum tube and testing whether the
velocity of the magnet will move at a constant rate and whether the velocity of the magnet will
continue to move at a constant rate once more and more weight is added to the magnet, and
discovering why the magnet moves at a constant rate even when weight is added or whether the
magnet moves at a continuously accelerating rate as more and more weight is added. This will be
done by looking at various physics concepts these concepts include; Lenz's law, Faradays law of
electromagnetism, Newton's first law of motion, induced ... Show more content on Helpwriting.net
...
Lenz's law can be seen to state that when a the north or south pole of a magnet is approaching the
nonconductive tube, the induced current flows in such a way as to make the side of the tube that is
nearest to the pole of the magnet to oppose the approaching magnet. Upon withdrawing the magnet
from the tube, the induced current can be seen to reverse itself, and the near side of the coil switches
poles to produce an attracting force on the receding bar magnet. This effect can be seen in the
diagram below: From analyzing the above diagram it can be seen that the above statements can be
perceived in a far clearer manor as the effect of the induced emf can be understood far more easily.
Furthermore Lenz's law also states that an induced current will only be formed if a magnetic object
is passed through the nonconductive tube or coil, which then creates a magnetic field that is equal
and opposite to the direction of the magnetic field as stated above. However if the magnetic object is
increased in velocity then the magnetic field strength will also be increased, which can be seen to
not only support Lenz's law but also faradays law of electromagnetism
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12.
13. The Effects Of Dioxide On Carbon Dioxide Flux Rate
The presence or absence of light in cyanobacterial species in Inland Sea, Qatar: effects on carbon
dioxide flux rate
Maryam Own
BIOG
14th of March 2013
Abstract
The Inland Sea in Qatar contains colonies of microorganisms living in both vertical and horizontal
zonation. Cyanobacteria live on the horizontal upper–intertidal layer of the soil.
Cyanobacteria is known for existing for more than 3.5 billion years, and has therefore adapted to
live in many conditions (in the cold Arctic or in the desert of Qatar). Since it is known for it is many
adaptive characteristics, it is usually a subject for research.
The purpose of this study was to measure the rate of influx of carbon dioxide in the presence of
light, and the rate of ... Show more content on Helpwriting.net ...
It can be concluded from the results that respiration took place in both the light and dark reaction
because of the physiological of cyanobacteria, where the carbon dioxide uptake mainly takes place
at night to reduce the loss of water
INTRODUCTION
The Inland Sea contains multiple microorganisms, where they are present in three horizontal zones,
and one vertical zone containing chemotrophic species. First, the horizontal lower–intertidal zone
contains distinct sulfur bacteria. Second, the horizontal middle–intertidal zone contains the
halophilic bacteria characterized by their reddish color. Last, the upper–intertidal zone contains
various species of cyanobacteria that include Nitrogen fixers and filamentous non–nitrogen fixers,
which will be the focus of this study. (Mahasneh, Al–Thani, & Brown, 2006) Cyanobacteria are
aquatic and photosynthetic bacteria that are known for existing for more than 3.5 billion years
(Introduction to the Cyanobacteria) absorbing a wide range of wavelength, as they also contain
chlorophyll f, a newly discovered type of chlorophyll that absorbs wavelengths in the red color
region ( Chen M, Li Y, Birch D, & Willows RD, 2012). Cyanobacteria can also form heterocyst,
which are responsible for fixing nitrogen for plants (Campbell Biology, 2011); this is important
when it comes to the evolution of plants. Plants carry photosynthesis and respiration in multiple
steps including: Light Reaction (Photosystem II),
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14.
15. Homework Assignment
Madison McCormack
Homework assignment # 5
Due date: May 8th 2018 11:59 PM
For each of the following terms, provide: (1) a definition relevant to plant ecophysiology; and (2)
source(s) from where the information was obtained (e.g. class notes, URL for website, citation for
book or article, etc.).
Leaf light Absorptivity: 1. The range of color that the leaf can absorb. 2. Class notes
Apoplastic ice formation: 1. Ice formation that begins in the apoplast. It freezes here first to avoid
damage to the plant. 2. Livingston, David P., et al. "Thermal Effect of CO2 on Apoplastic Ice in Rye
and Oat during Freezing." Plant Physiology, American Society of Plant Biologists, 1 Mar. 2000,
www.plantphysiol.org/content/122/3/861.
Convective heat flux: ... Show more content on Helpwriting.net ...
The flux of water vapor multiplied by the latent heat of vaporization. 2. Roland, Stull. "Latent Heat
Flux." Egyptian Journal of Medical Human Genetics, Elsevier, 2006,
www.sciencedirect.com/topics/earth–and–planetary–sciences/latent–heat–flux.
Reactive oxygen species: 1. Chemically reactive forms of oxygen. Can be a natural end product of
the metabolism of oxygen. Can help in homeostasis and cell signaling. 2. "Reactive Oxygen
Species." Wikipedia, Wikimedia Foundation, 14 Apr. 2018,
en.wikipedia.org/wiki/Reactive_oxygen_species.
Membrane integrity: 1. Keeps things getting in and from getting out of the cell. If integrity is lost
than things leak out and important things cannot get in. 2. "What Does Plasma Membrane Integrity
Mean?" Yahoo! Answers, Yahoo!, answers.yahoo.com/question/index?
qid=20080427224456AAmTY9S&guccounter=1.
Metabolic heat flux: 1. Rate of molecules moving throughout a metabolic pathway. 2. "Flux
(Metabolism)." Wikipedia, Wikimedia Foundation, 3 Apr. 2018,
en.wikipedia.org/wiki/Flux_(metabolism).
Plant pathogens: 1. Plant pathogens are organisms that cause diseases in plants. 2. McMahon, Mary,
and O. Wallace. "What Is a Plant Pathogen?" WiseGEEK, Conjecture Corporation, 7 May 2018,
www.wisegeek.com/what–is–a–plant–pathogen.htm.
Leaf light Reflectivity: 1. How well a leaf can reflect harmful UV rays. 2. Class
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16.
17. Essay On Three Phase Induction Motor
Analysis of Dynamic Performance of Three Phase Induction Motor Using Matlab Simulation
Brahmananda Das Department of electrical engineering Koustuv group of institutions Bhubaneswar
dasbrahmananda1972@gmail.com Abstract: This paper investigates the dynamic performance of
three phase induction motor by vector control method. The vector control algorithm is calculated on
Motorola DSP56F80X. The block diagram is shown in figure which describes the structure of
implement vector control algorithm. The result obtained is verified using matlab simulation. Initially
speed reference is set at120 radian/s and torque taken as 0 nm. Then motor is run, speed, torque and
current wave form is taken. Now speed reference changes to 160 radian/s and torque changes to
200nm and correspondence wave form is shown. I observed that it run smoothly over the full speed
range, generate full torque at zero speed, and have high dynamic performance including fast
acceleration and deceleration. It was originally developed for high–performance motor application
for industrial drives. However, it is becoming increasingly attractive for lower performance
applications as well due to FOC 's motor size, cost and power consumption reduction superiority. ..
In vector control method machine is control in a synchronously rotating frame where as in
sinusoidal machine variables appears as D.C. quantities. In steady state current resolved in to two
control inputs I. e. direct axis and quadrature axis component
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18.
19. The Vector Control Of The Pm Synchronous Motor
currents) from stationary reference frame to torque and flux producing currents components in
rotating reference frame. The vector control of the PM synchronous motor is derived from its dq
dynamic model. Considering the currents as inputs, the three currents are: ia = Is sin (ωrt + α) (4.12)
ib = Is sin (ωrt + α – ) (4.13) ic = Is sin (ωrt + α + ) (4.14)
Where ωr is the electrical rotor speed and α is the angle between the rotor field and the stator current
phasor, known as the torque angle.
The d and q axes stator currents in the rotor reference frame for a balanced three phase operations
are given by
irq ird Substituting the equations (4.12) in (4.14) into (4.15) which gives the stator currents in the
rotor reference frames: irq sin α ird cos α
The d and q axes currents are constant in the rotor reference frames, since the α is constant for a
given load torque. For this behaviors they are very similar to armature and field currents in self–
excited dc machine. Substitute the above equation into the electromagnetic torque shown in below:
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20.
21. Critical Heat Flux : An Overview
CRITICAL HEAT FLUX Abhishek Kumar Sunkavalli
University of Houston, Cullen College of Engineering
Email: abhishek.ky370@gmail.com
Abstract: This paper presents an overview of major issues, recent achievements, and future needs for
critical heat flux (CHF) research focusing on nuclear reactor applications. Covered areas are: (a)
understanding of physical mechanisms, (b) prediction methods for simple and complex geometries,
and (c) enhancement of CHF. Significant advances have been made during the last 15 years, in
particular, in the areas of theoretical modeling. However, considering the significance of the
phenomena and insufficient modeling capability, extensive R&D activities are still required in
several areas, including clear identification of physical mechanisms for low–quality and pool–
boiling CHF, extension of CHF data bases for new applicable ranges and transient conditions,
improvement of prediction methods focusing on theoretical models, development and application of
CHF enhancement techniques, etc.
Introduction:
The critical heat flux (CHF) condition is characterized by a sharp reduction of the local heat transfer
coefficient that results from the replacement of liquid by vapor adjacent to the heat transfer surface
.The occurrence of CHF is accompanied by an inordinate increase in the surface temperature for
heat–flux–controlled systems, and an inordinate decrease in the heat transfer rate for temperature–
controlled systems. The CHF condition is
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22.
23. The Theory Of Philip And De Vries
(Saito, Simunek, & Mohanty, 2006)
Early pioneering studies on interactions between liquid water, water vapour, and heat movement
were reported by Philip and de Vries (1957), who provided a mathematical description of liquid
water and water vapour fluxes in soils driven by both pressure head (isothermal) and soil
temperature (thermal) gradients.
They derived the governing flow equation for non–isothermal flow as an extension of the Richards
equation, which originally considered only the pressure head gradient. The theory of Philip and de
Vries (1957) was later extended by Nassar and Horton (1989), who additionally considered the
effect of an osmotic potential gradient on the simultaneous movement of water, solute, and heat in
soils.
Heat transport and water flow are coupled by the movement of water vapour, which can account for
significant transfer of latent energy of vaporization. Soil temperatures may be significantly
underestimated when the movement of energy associated with vapour transport is not considered.
For example, Cahill and Parlange (1998) reported that 40 to 60% of the heat flux in the top 2 cm of
a bare field soil of Yolo silt loam was due to water vapour flow. Fourier?s law describing heat
transport due to conduction (e.g., Campbell, 1985) thus needs to be extended to include heat
transport by liquid water and water vapour flow. The general heat transport model then considers
movement of soil heat by (i) conduction, (ii) convection of sensible heat by liquid
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24.
25. Western Art Music : A Constant State Of Flux Since Its...
Western art music has been in a constant state of flux since its creation. Evolving due to generations
constantly contributing and evolving music in order to express what they believe music is and
express how they feel. This love and dedication towards music has been unparalleled and
unwavering for hundreds of years from sacred medieval music to modern day pop hits. Western Art
music began taking the shape that we know today after the fall of Rome with Medieval music.
Almost all music from that time was commissioned by the church (Secular music) and were
required to be written down in order to share with other members of the congregation. All music at
this time was monophonic (containing only one melody line) in droning style which is ... Show
more content on Helpwriting.net ...
The modern orchestra was born, the harpsichord was invented and all of the instrumental groups
received upgrades, including the strings creating the violin, viola, and cello. This is also when a lot
of common modern music terms were coined; such as overture, prelude, aria, chorus, concerto, and
sonata. The essence of music changed at this point in time. Music was finally regarded as something
to be treasured, something that should be enjoyed by everyone, something that should be able to
hear everywhere not just at church. Music was played at formal gatherings, garden parties and for
the wealthy it was even played at home during meals. Almost every 'woman of the house' in Europe
had some sort of instrument that they practised as a way to pass time and demonstrate their skills.
The style of music in the Baroque era was often considered chaotic, there seemed to be no structure
to the pieces however, they flowed beautifully. The next musical period is the most well known, the
classical period. It continued the aforementioned modernisations of the baroque era however added
its own uniform quality to it. The baroque period was known for being wild, untamed, and chaotic,
than came the classical period which practically reversed this. The classical period was very uniform
everything was structured, everything was their for a reason, and everything had to be played in
perfect timing. Despite its
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26.
27. How Does Heraclitus View Of Change
Heraclitus' fragment on Flux gives profound insight into the relationship of our perception of
consistency, change and destruction in nature. Although much of what is written about Heraclitus
suggests everything is constantly changing, some fragments like his claim that the world is an ever–
living fire suggest there is some consistency in a law–like exchanging of elements, embodied by
fire. The fragment regarding flux and change has ambivalent interpretation due to the controversial
readings of his riddles and wordplay and the need to use secondary sources as a formal quotation,
making the argument concerning to what extent Heraclitus held a view of constant change
practically impossible. Plato's interpretation of the flux fragment is generally ... Show more content
on Helpwriting.net ...
Cyclical change is the cause of the transformation of one thing into another, the change is not a
physical, material thing but it is a symbolic process of change according to a constant law of
transformation that can be identified in relation to the Logos. Heraclitus did not view any single
thing as the root of all change, differentiating himself from the Milesian philosophers of the time.
Previously, it was common belief that one thing caused all things to change; Heraclitus disagreed
and claimed that no inference could be made from observing change that it was any single thing
orchestrating change. Heraclitus maintained the view that fire changes to water and water to earth,
followed by earth changing into water and then fire. Concerned either at the level of cosmic bodies
like the sea, turning into a fiery storm, or integral domestic doings by which water boils out of a pot,
flux is constant and observable in opposites. For every change there must be an opposite reaction in
order to maintain the natural equilibrium of the world.
It was believed by Plato that by following the doctrine of flux of all sensible things, knowledge is
made impossible. Heraclitus however does nothing to reject knowledge or wisdom from correct
intellect of the cosmos. He did however believe that most people are merely sleepwalking in life,
incapable of having wisdom. Knowledge
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28.
29. A Reflection On The Current Psyche Of The Modern World
The world succeeds by surviving through living in flux. Constant motion is what demonstrates our
humanness. It shows our strength, our fragility, and our imagination for greater things, "...things are
constantly undergoing processes of transformation, deformation, and restoration and that the essence
of life and being is movement" . Consideration of flux in our current society is imperative in
understanding the current psyche of the modern persona. First Nations have taken this idea of flux
throughout our life, and we have embraced the idea and moved with it. However, this is not to say
that we can not be successful in our contemporary linear worldview. In the modern world today we
must be able to tune in to both the linear and the flux.
To ... Show more content on Helpwriting.net ...
"The Navaho are the most studied of all Native American groups. For well over a century now,
scholars have been attracted to the Navajo culture; it has flourished in the face of the same pressures
that have all but erased many other Native American cultures, largely because it has managed to
change with the times while remaining strongly rooted in tradition" .
This is an answer to the question how First Nations can survive and thrive in the western culture.
The Navaho seeks to eliminate all the friction in their lives and move forward toward the restoration
of harmony in their lives. The Navaho's "basic quest is for harmony" and their quest coincide with
the Blackfoot's survival through flux. Harmony moves through flux, a constant fluctuation that all
First Nations recognize. Yet Navaho are successful living in the western culture, which is not to say
that they are not most comfortable living in the Navaho lifestyle.
In the beginning the Westerners and Indigenous led a separate life and had no interaction in any way.
As time went by First Nations land was discovered and Westerners began to trade with First
Nations. In time children were born from this trade and our two nations coalesced and were
considered "engaged". "With a signing of treaties, an agreement to interact now existed that... would
engage Indigenous peoples and the Canadians"
In my lifestyle I was brought up both in the Western frame of mind and the First
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30.
31. The Energy Supply And Usage Of Renewable Energy
Chapter 1: Introduction to Thesis
Introduction to Thesis
1.1 Statement of the problem
The world's energy supply and usage harnessed by humans are predominantly occupied by fossil
fuel combustion a non–renewable resource. On the other hand small fractions of the energy
harnessed by humans are renewable resources at only about 13% of the total energy sourced. With
fossil fuels emitting high amounts of greenhouse gasses that affect our climate negatively in the long
term in addition to its non–renewability, alternative sources of energy supply particularly in the
category of renewable energy can help alleviate the impact of the shortage of resources and the
harmful impact of our energy usage on the environment. Salinity–gradient energy can potentially be
a part of this alternate source of renewable energy as well as gas emission–free as it is based on the
mixing of solutions with different salt concentrations through the uses of Osmotic pressure and a
membrane.
Salinity–gradient energy is applied through the application of pressure retarded osmosis (PRO) and
its use for power generation has made it a viable pairing for desalination plants that use reverse
osmosis/forward osmosis (FO/RO) in its processes.
Salinity–gradient energy has only gained substantial attention in the last 10 years due to increasing
cost of fossil fuels and because of its relatively new upbringing there is still a lot of research and
understanding to be achieved. One of the major reasons for this belief
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32.
33. Design And Analysis Of Control System Structures For...
This thesis deals with the design and analysis of control system structures for electric drives
equipped with permanent magnet synchronous machines (PMSM) in automotive application.With
the increasing popularity of multi–level inverters, the room for improvement of the performance of
voltage source inverters has continuously been tested for various applications. The rapid
development of high switching frequency power electronics in the past decade leads towards wider
application of voltage source inverters in AC power generation. Therefore, this prompts the need for
a modulation technique with less total harmonic distortion, fewer switching losses, and wider linear
modulation range.The present thesis highlights the comparison of the conventional two–level
inverter and the three–level diode clamped inverters for the application in automotive industry. The
thesis highlights the DC–link balancing control which is the most commonly faced problem in case
of a three–level diode clamped inverter, with no additional circuit. Modifications of the modulation
techniques for the realization of the DC–link balancing control have been proposed. Comparison of
the total harmonic distortion of the line–to–line voltages at the outputs of the two and three–level
inverters has been presented for PWM, SVPWM &CB–SVPWM techniques. The thesis also deals
with the control of the Permanent Magnet Synchronous Motor drive using Field–Oriented Control
technique. A PMSM drive system based on Field
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34.
35. Overview of Ecology Topics: Energy Flux, Food Webs and...
Energy Flux in Ecological Systems The concept of ecology considers interactions between
organisms and their environment across several scales of analysis. Population ecology includes
investigations of the physiological principles that modulate how individuals interact with their
environment, and resource competition theory that explores the dynamics of both individual and
interacting species. Community ecology focuses on large assemblages of species and considers how
in fluxes of matter and energy can define collections of species within an ecosystem. Consequently,
the concept of an ecosystem must consider how nutrient cycles shape the rate and efficiency of
energy transfer among and between species and communities. This essay will ... Show more content
on Helpwriting.net ...
Intra– and interspecific competition Negative feedback processes can occur when different
individuals within a population compete for a limiting resource. This is termed intraspecific
competition. These effects can be extended to include pairwise interactions between species (e.g.
competition, mutualism, predator–prey), which is termed interspecific competition. To illustrate this
concept and how it relates to resource limitations, the concept of predator–prey interactions will be
discussed briefly. Gause conducted early experiments on simple species such as yeast and paramecia
to examine simple species assemblages and determine theoretical conditions of resource abundance
that might allow species to stably coexist (Gause 1934). His experiments were coupled with the
mathematical framework of Lotka–Volterra equations (Lotka 1925, Volterra 1926), and led to the
discovery that for two species with identical nutrient requirements, competition for limited resources
in a stable environment would ultimately lead to the competitive exclusion of one species against
the other. Though overly simplistic, the trends observed in these studies were confirmed in other
systems (e.g., rotifer–algae chemostats experiments: Yoshida et al. 2005, lynx–hare cycles: Hewitt
1921). This was formulated as the R* rule in exploitative competition by Tilman (1982), which
states that when two or more species are limited by the same resource, the species that can
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36.
37. Using Conventional Method And Space Vector Pulse Width...
Direct torque control of induction motor simulation using conventional method and space vector
pulse width modulation Naveen chander PG Student Electrical Engineering NITTTR Chandigarh,
India snl.naveen@gmail.com Dr. Lini Mathew Associate Professor Electrical Engineering NITTTR
Chandigarh, India Dr. S. Chatterji Professor & Head Electrical Engineering NITTTR Chandigarh,
India Abstract–This paper proposes direct torque control of induction motor simulation using
conventional method and space vector pulse width modulation technique for ripple reduction. Direct
Torque Control is a control technique used in AC drive systems to obtain high performance torque
control and thereby controlling the speed of induction motor. The principle is based on simultaneous
decoupling of stator flux and electromagnetic torque of AC drive system. DTC drives use hysteresis
comparators and they suffer from high torque ripple and variable switching frequency problem. The
proposed SVM based DTC reduces torque ripples. The basis of the SVM–DTC methodology is the
calculation of the required voltage space vector to compensate the flux and torque errors and its
generation using the SVM at each sample period. The performance of this method is demonstrated
by simulation using MATLAB/Simulink software. Simulation results presented in this paper show
the torque, flux linkage and stator current ripple decreases with the proposed SVM–DTC algorithm.
Keywords: Direct Torque Control, Space vector pulse
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38.
39. Modern Potentials And Applications Of Ferrofluids
Ferrofluids are nanoscopic shards of magnetic particles suspended in organic fluids or water. What
are the modern potentials and applications of ferrofluids? Ferrofluids have current applications in a
variety of fields and continue to have potentials for further advancements in others. With research of
the first ferrofluid in 1963 by Steven Papell with N.A.S.A., ferrofluids have been used to provide
advancements in the field of technology. In modern times, ferrofluids are used in speakers for their
relationship with magnetism and heat; as well ferrofluids are used in computer hard drives for their
unique magnetic fluidic properties. Additionally, ferrofluids have potentials in the field of bio–
medical engineering, including: advancements ... Show more content on Helpwriting.net ...
Within the bio–medical industry, ferrofluids could improve M.R.I. image rendering and assist in the
treatment of cancer patients. M.R.I's use the intermediate magnetic relaxation periods of organs,
which is the amount of time it takes a tissue to react and equalize to a magnetic force, to construct
an image. These periods vary only slightly, thus creating dim and low resolution images; but if one
was to saturate an organ with an easily manipulated magnetic fluid, such as a ferrofluid, one could
see with great contrast the difference between native and foreign tissues. This usage would allow
examiners to better identify tumors or unhealthy organs. In like ideas, the "localizability of a portion
of ferrofluid by a magnetic field, associated with the fact that any liquid may be turned into a
magnetic fluid," (Scherer & Figueiredo Neto 725) can be used to manipulate medication in a way to
reduce side effects and increase the effectivity of the treatments. Researchers believe this may be a
way to reduce the enervating effects of chemotherapy, thus improving the overall treatment.
Ferrofluids would present in the medication, and doctors could use magnetic influences to
manipulate the location and longevity of the medication; along with this manipulation, doctors could
lower the dosage because they no longer have to take in to consideration the dispersal of the
medication throughout the body, simply the centralized
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40.
41. Advantages And Disadvantage Of Electric Vehicle
1.1 Introduction Global warming by carbon dioxide and air pollution is getting serious these days, as
a result that led to increased attention for the idea of Electric Vehicle (EV). The idea of an EV has
been around for almost 200 years. Thomas Davenport built the first EV in 1834. Until a few decades
ago, batteries seemed to be the only device capable of storing the energy in a safe manner.
Unfortunately, batteries are still not able to store the amount of energy needed to fulfill the needs of
an electric vehicle completely. They also have a low energy to weight ratio and problems with the
recharging of the battery are not completely solved [1]. Recent developments in microprocessors,
magnetic materials and semiconductors technologies have offered an excellent opportunity to use ac
motor in high performance ... Show more content on Helpwriting.net ...
Some of these are summarized as follows [12]: The only parameter that is required is stator
resistance; The switching commands of the inverter are derived from a look–up table; Simple
hysteresis controllers are used for torque and stator flux linkage control; Vector transformation is not
applied because stator quantities are enough to calculate the torque and stator flux linkage as
feedback quantities to be compared with the reference values. Although there are several advantages
of the DTC scheme over vector control, still has a few drawbacks or problems, DTC disadvantage
can be explained as following [11]: Variable switching frequency; High sampling time is required;
Inverter switching frequency depending on: flux and torque hysteresis bands, machine parameters,
sampling frequency; Current and torque distortion caused by sector changes; Start and low speed
operation problems; High noisy level; High current and torque
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42.
43. Transformer Is A Static Machine Used For Transforming Power
Definition of Transformer
A transformer is a static machine used for transforming power from one circuit to another without
altering frequency. This is a very clear definition of transformer.
History of Transformer
The history of transformer was commenced in the year 1880. In the year 1950, 400KV electrical
power transformer was introduced in high voltage electrical power system. In the early 1970s, unit
rating as large as 1100MVA was produced and 800KV and even higher KV class transformers were
manufactured in year of 1980. Use of Power Transformer
Generation of electrical power in low voltage level is very much cost effective. Hence electrical
power is generated in low voltage level. Theoretically, this low voltage level power can be
transmitted to the receiving end. But if the voltage level of a power is increased, the current of the
power is reduced which causes reduction in ohmic or I2R losses in the system, reduction in cross
sectional area of the conductor i.e. reduction in capital cost of the system and it also improves the
voltage regulation of the system. Because of these, low level power must be stepped up for efficient
electrical power transmission. This is done by step up transformer at the sending side of the power
system network. As this high voltage power may not be distributed to the consumers directly, this
must be stepped down to the desired level at the receiving end with the help of step down
transformer. These are the uses of electrical power
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44.
45. Spectral Line Fitting Using Ptf And Pessto
Spectral Line Fitting The discussion so far has mentioned that each SNe has its own spectrum, with
some having more than one if taken on different days. These spectra provide details about the
composition of the system for example the strong silicon feature for Type Ia SNe, and can also be
used to determine properties such as ejecta velocities and equivalent widths. The data obtained from
PTF and PESSTO is a combination of flux and wavelength values, with wavelength range typically
between 3000 and 9000Å. The flux values had to be de–reddened to account for absorption and
scattering of the electromagnetic radiation from the SNe, due to dust and gas present in the
interstellar medium and the Earth's atmosphere. To do this a reddening ... Show more content on
Helpwriting.net ...
Initially the silicon feature fluxes were normalised, and then the velocity and equivalent width
values were obtained. The same procedure was then performed for the calcium feature. They were
normalised due to the peaks surrounding the features having a large variation in flux. This process
involved selecting two points on the silicon feature, the peaks either side of the trough. From these
points, a simple line fitting procedure created a straight line joining the two. The gradient, intercept
of the line and wavelength values combined with the original flux calculated the new flux (equation
2 for details of normalisation). f_new=f/(λ(m+c)) (2) Where m is the gradient and c is the intercept.
Figure 2. Left Panel: Graph displaying flux in ergs–1cm–2Ang–1 against wavelength in Å for the Si
II 6355Å feature of SNe Ia PTF09akt. Wavelength range restricted between 5000 and 7000Å clearly
displaying this feature located at approximately 6100Å. Right Panel: Graph display normalised flux
values in arbitrary units against wavelength in Å. The feature remains at same wavelength location
but is now more symmetrical. A Gaussian is a symmetrical bell curve shape and is a continuous
function that approximates the binomial distribution of events. The flux normalisation performed
allows for a more accurate Gaussian fit due to increased symmetry in the spectral features. The
silicon feature required the use of
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46.
47. 3D-Ic Essay
Increasing demand for the high–performance processors, increase in the number and length of the
global wires have been required even with the higher clock speed. It brings about the higher power
consumption to reduce the signal delay [1]. The 3–D structure has been developed to overcome the
challenges [2]. Several active layers are vertically stacked and each component that is located in the
different layers can be connected by through–silicon–vias (TSVs) to communicate each other. The
new structure not only provides the geometrical flexibility, but also the shorter length of the global
wires allowing a higher clock and a lower power consumption [3]. The thermal issue should be
considered to ensure the reliable operation of the processors. ... Show more content on
Helpwriting.net ...
Zhang, Y et al. fabricated the micro pin fin structures having 200 µm height. TSVs were located on
the inside of the pin fins [14] [15] [16]. They optimized the dimensions of pin fins by considering
the cooling performance and TSVs performance. The results showed that the junction temperature is
53.5 ˚C at 105 W/cm2 heat flux and 45 mL/min flow rate, and 47.9 ˚C at 103.4 W/cm2 heat flux and
70 mL/min flow rate in single–phase cooling [14]. They embedded two microfluidic layers that are
independently controlled by different pumps to reduce the temperature difference between layers
[16]. Single–phase cooling with a various kind of microchannel structures and geometry sizes were
studied to find the most effective channel structure [17]. In the results, in–line pin fin structure
showed the best cooling performance and it could handle 681 W/cm2 uniform heat flux with 60 kPa
pressure drop. Abas Abdoli et al. reported that single–phase cooling could dissipate 1000 W/cm2 of
the background heat flux and 2000 W/cm2 of the hotspot heat flux [18]. The mentioned experiments
show a high potential of water cooling to dissipate a high heat flux in 3D–IC with the interlayer
channel. Two–phase cooling with the embedded microchannel structures is one of the promising
cooling technique. Issam Mudawar revealed that using phase change process is very efficient
method having the high cooling capability with a small temperature increase meaning a high heat
transfer
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48.
49. Essay On Hml
The collisionless reconnection of two parallel flux ropes driven by both the coalescence and kink
instabilities is examined using fully kinetic simulations in periodic and line–tied geometries. The
three–dimensional (3D) reconnection rate is computed from the maximum of the quasi–potential,
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50.
51. Essay on Photography in Flux
Photography in Flux
It is no secret that digital photography is very rapidly finding a niche in modem society, in both the
professional realm as well as in the home. The advent of newer, faster, and more embellished
technologies have placed the power of photographic production in the hands of the common person.
An art form that formerly was left to the charge of few skilled professionals has been forever
changed by these technologies. Certainly, this evolution of sorts has its strengths as well as its
drawbacks. What advantages does a photographer have with digital technology that he or she might
not have with a traditional camera? What are the disadvantages? And what does this technology
mean for the future of the photography ... Show more content on Helpwriting.net ...
As Keith Davis puts it in An American Century of Photography: From Dry–Plate to Digital, it is on
the computer screen where "the components of these original photographs become completely fluid,
open to endless alteration, deletion, and recombination" (318). The power of image manipulation
and control afforded by the digital media has opened the door on a "dynamic visual universe that
offers, those eager to meet the challenge, the potential and vitality of infinite design capabilities"
(Ziegler and Greco, 5).
Furthermore, another noted advantage of digital photography is "the instant on–screen viewing of
images" which are "available instantaneously" (Grahame). Bad shots, muffs, and outtakes can be
deleted immediately, as opposed to wasting one or two exposures on a roll of film. The good images
can be saved and catalogued for later editing, or they can be viewed on the camera itself. This
capability allows the photographer to find what images he or she wants to use and store them, to
make better expediency of the camera's memory storage. Most if not all digital cameras allow the
user to scroll through entire directories of images in–camera, as well as zoom in or out on any
picture. Indeed, some of the more expensive cameras even have limited editing capabilities built in.
Other professional photographers cite additional advantages to using digital equipment for their
work. Jim Brandenburg, in an interview
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52.
53. The Motor Effect
2.1 Motors use the effect of forces on current–carrying conductors in magnetic fields
2.1.1 The motor effect
The motor effect is where a force acts on a current–carrying conductor in a magnetic field.
The right hand palm rule is used to find certain properties: fingers point to magnetic field, thumb
points in DC direction and palm points to direction of the force.
2.1.2 Factors affecting the force acting on the current–carrying conductor Forces are experienced by
the electrons in the conductor and are affected by: * Length of conductor (longer conductor means
more electrons hence more electrons experiencing the force) * Strength of magnetic field (more
force on electrons) * Amount of current in conductor (more current ... Show more content on
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ie there is a change of magnetic flux through a circuit. Faraday's experiment: Connect a coil of many
turns to a zero centered galvanometer. Move a small magnet in and out of the coil and we can
observe a small current is produced when the magnet is moved but no current when there was no
movement. By varying the speed (relative motion) of the movement and strength of magnet, the
galvanometer flickered more therefore more current produced. Distance also affects this.
2.2.2 Magnetic field strength and magnetic flux density Magnetic flux density (B) is a measure of
the number of lines of force per unit area. It is also equivalent to the strength of the magnetic field
and is measured in Weber (Wb)
2.2.3 Magnetic flux Magnetic flux (φ) is a measure of the number of lines of force emerging through
an area. It is the product of magnetic flux density and area : φ=BA measured in Webers (Wb)
2.2.4 Size of the induced emf The induced emf is proportional to the rate of change of magnetic flux
through the circuit.
2.2.5 Len's Law Len's law: the direction of the induced emf is such that it opposes the change that
produced it. Len's law is a consequence of the law of conservation of energy because if the induced
emf aided the motion, then the conductor would accelerate causing a greater emf, which would
cause further acceleration, etc ... an infinite amount of energy would be created.
2.2.6 Len's Law and back emf
2.2.7 Back emf in electric motors
2.2.8 Eddy
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54.
55. The Magnetic Field Of A Permanent Magnet
Assignment.
Task 3.1
a) The magnetic field of a permanent magnet causes the atoms to move around uniformly in the
same direction. This may vary depending on the electrons of the atoms causing a variety of atoms to
be able to do this and few which can hold a permanent magnetic field. It is an invisible field and it is
also called a vector because of the forces specified direction and magnitude. The arrow displays the
direction of the force and also how the forces are. The closer the lines are together it shows how
much stronger it is also the further away they are it shows how much weaker they are.
Magnetic flux; the units for magnetic flux is Weber(Wb) and for magnetic flux density is used as
Telsa(B) as a unit.
b) B= Flux ... Show more content on Helpwriting.net ...
If the magnet is withdrawn, the direction of the current is reversed. Such currents are called induced
currents. The current flows in the conductor as a result of an electromotive force that is induced the
so called induced EMF
The effect of conductor moving through a magnetic field is that it would cause a electromagnetic
field which is used in transformers to change current and voltage.
Mutual inductance is the magnetic field generated by a coil of wire which induces a voltage in the
other coil of wire. A transformer is an object constructed of multiple numbers of coils in close
proximity to each other, with the express purpose of creating a condition of mutual inductance
between the coils.
Transformers Having a different number of coils between two coils of wire can cause a decreas of
voltage of AC currents in applications. Transformers are based on Faraday's Law of electromagnetic
induction and mutual induction; the transformer has the first wire coil that emits a magnetic flux that
has a EMF in a secondary wire coil with aid of a high magnetic permeable core.
Task 3.4
Series wound DC motor The characteristic of a series wound DC motor is that its speed is
proportional to the load and as there is a lower load it has an increase in speed. Also the torque
allows for moving of large loads allowing it to be
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56.
57. Interview Questions On How Are You Qualified For This...
Interview Questions
1. How are you qualified for this position?
I saw from your job posting that you are looking for 1st and 2nd year apprentices who can work
with FCAW. I'm currently a 1st year registered apprentice and I gained a lot of experience working
with Flux core welding at school. I improved my skill with this type of welding at my work term
with RM&S. I worked mostly with stainless steel wire which is a difficult metal to work with but
this improved my skill using regular flux core wire greatly. I also got the chance to complete some
fabrication work on my work term where I built custom orders such as tables and truss's from
blueprints provided by the customer. I currently have all position FCAW CWB ticket as well as the
flat and horizontal SMAW tickets. I also have the required safety certifications required for your
company which allows me to start as soon as you need me. As you can see from my resume, most of
my experience has come from customer service in a call center, however, I feel that this experience
taught me to work with little supervision but also be part of team when required. I developed a good
understanding of what customer satisfaction really is. I am confident that these skills and
experiences will translate well with this position and your company.
2. Describe a time you had to adjust to change. Did you cope or adjust to this change?
I have almost 10 years of experience working in a call center. I don't know if you aware of this
industry, but
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58.
59. Disadvantages Of Membrane Distillation
As time goes by, the fresh water supplement for living on the earth planet will become a serious
problem [1–3]. In addition, the Middle East is mentioned as one of the poorest regions in all over the
world in terms of water resources with less than 1% of the total available global freshwater per
capita [4, 5]. Therefore, one of the strategic options to satisfy the current and future request for fresh
water in countries established around Gulf is to build up desalination units. So, immediate need has
arisen to construct economic units for water desalination. Nowadays, it has been proved that
membrane separation processes have several advantages for desalination and water reuse of
contaminated resources in comparison to the conventional separation methods [1, 6–8]. ... Show
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MD is a thermally driven separation process that utilizes a hydrophobic, membrane as a contactor
media between two fluids kept at different temperatures where the separation is obtained by the
mass transfer of the vapor phase. The driving force of the process is given by a partial vapor
pressure difference that caused from the temperature difference [13–17]. Two advantages of MD are,
the process performance is not highly affected by high feed salinity as see water, and has the
theoretical ability to reach 100% salt rejection [13, 18, 19]. There are commonly four types of
membranes arrangements for MD process: Direct Contact Membrane Distillation (DCMD), Vacuum
Membrane Distillation (VMD), Air Gap Membrane Distillation (AGMD), and the Sweeping Gas
Membrane Distillation (SGMD) [18, 20–22]. AGMD configuration is appropriated for water
desalination [23, 24], on the other hand water gap showed higher thermal efficiency and less internal
heat loss in comparison to AGMD [18, 25]. Therefore, these two arrangements are commonly used
for the see water
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60.
61. Montaigne 's Skepticism Argument Of Constant Flux
Montaigne's Skepticism Argument of Constant Flux This skeptical argument is based around the
premise that there is no constant existence. This means that there is no unchanging being nor
nonbeing object. Everything is changing, growing, learning, multiplying, and moving. With constant
movement comes constant change of both the known and the knower, and since there is no being
nor object that does not change, both the person and their judgement continue flowing, which then
allows nothing to be established for certain (MP, 13). Human nature is constantly in the middle of
being born and dying, and are subject to passing from one change to another as humans grow, learn
and change. Everything is either coming into being and growing, making it a current incomplete
substance, or it is beginning to die. An example that helps one to understand this argument is the
concept of a woman birthing a baby boy (MP, 14). This baby is always changing, every moment of
every hour of each day. At first the infant leaves the mother's womb as an unformed infant, then
becomes a suckling infant completely dependent on its mother. He is continuously learning that
when he is hungry or needs to be changed, he simply needs to cry. He learns to laugh and make
noises, sit up and crawl. Eventually he learns to walk and talk and then one day the baby boy is not a
baby anymore. He is a boy, and then a youth, next a mature man, then a man, and finally a decrepit
aged man (MP, 14). This change seemingly
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62.
63. Autophagosomal Pool Flow
Due to the advances in time–lapse fluorescence microscopy and the development of
photoswitchable fluorescent proteins, autophagic flux can also be monitored by assessing the half–
life of the LC3 protein240 Tsvetkov AS, Arrasate M, Barmada S, Ando DM, Sharma P, Shaby BA,
Finkbeiner S. Proteostasis of polyglutamine varies among neurons and predicts neurodegeneration.
Nat Chem Biol 2013; 9:586–92; http://dx.doi.org/10.1038/nchembio.1308.
[CrossRef], [PubMed], [Web of Science ®] [Google Scholar] post–photoactivation or by
quantitatively measuring the autophagosomal pool size and its transition time.241 Loos B, du Toit
A, Hofmeyr JH. Defining and measuring autophagosome flux–concept and reality. Autophagy
2014:0.
[PubMed], [Web of Science ®] ... Show more content on Helpwriting.net ...
In its simplest form, the Rluc–LC3–assay can be used to estimate autophagic flux at a single time
point by defining the luciferase activities in cell extracts. Moreover, the use of a live cell luciferase
substrate makes it possible to monitor changes in autophagic activity in live cells in real time. This
method has been successfully used to identify positive and negative regulators of autophagy from
cells treated with microRNA, siRNA and small molecule libraries.242– Farkas T, Hoyer–Hansen M,
Jaattela M. Identification of novel autophagy regulators by a luciferase–based assay for the kinetics
of autophagic flux. Autophagy 2009; 5:1018–25; http://dx.doi.org/10.4161/auto.5.7.9443.
Frankel LB, Wen J, Lees M, H(o)yer–Hansen M, Farkas T, Krogh A, Jaattela M, Lund AH.
microRNA–101 is a potent inhibitor of autophagy. EMBO J 2011:4628–41;
http://dx.doi.org/10.1038/emboj.2011.331.
Farkas T, Daugaard M, Jaattela M. Identification of small molecule inhibitors of
phosphatidylinositol 3–kinase and autophagy. J Biol Chem 2011; 286:38904–12;
http://dx.doi.org/10.1074/jbc.M111.269134.
Szyniarowski P, Corcelle–Termeau E, Farkas T, Hoyer–Hansen M, Nylandsted J, Kallunki T,
Jaattela M. A comprehensive siRNA screen for kinases that suppress macroautophagy in optimal
growth conditions. Autophagy 2011; 7:892–903; http://dx.doi.org/10.4161/auto.7.8.15770. 248
Nguyen HT, Dalmasso G, Muller S, Carriere J, Seibold F, Darfeuille–Michaud A. Crohn's disease–
associated
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64.
65. Design Of Reliable And Effective Damage Detection Techniques
Problem Definition
Composite materials and structures are particularly attractive for aerospace applications due to their
high stiffness, high strength and low weight properties. The use of such structures allows for an
overall aircraft mass reduction, reduced fuel consumption and increased service life resulting in a
reduction in aircraft operating costs.
Early detection of damage within composite structures is of prime importance to safety and
reliability. When a void is present, internal stresses in the material are not distributed evenly,
resulting in high stress concentrations around the area where the damage has occurred. In general
the presence of defects results in poor structural performance, decreased load carrying ... Show more
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Shape memory alloys, optical fibres, piezoelectric and magnetostrictive materials currently represent
the most suitable options for smart structural applications. Piezoelectric and magnetostrictive
materials have both sensing and actuation capabilities.
With the recent development of magnetostrictive material (Terfenol–D) in particle form it is possible
to embed or surface bond a smart layer in composites structures without sacrificing their mechanical
properties while exploiting the larger strain as compared to the use of piezoelectric materials. [3][[4]
demonstrated the feasibility of sensing delaminations in composite laminates using embedded
magnetostrictive particle layers, [5] use a magnetostrictive patch to sense for multiple
delaminations. Configurations employed so far make use of external sensors and offline inspections.
This paper proposes a magnetostrictive sensor configuration for an online, structural integrity
monitoring system.
Background
Magnetostriction
Magnetostriction is a property of ferromagnetic materials that exhibit a mechanical strain in
response to an applied external magnetic field. This effect is a reversible exchange of energy
between the mechanical and the magnetic form. Magnetostriction was first described in 1842 by
James Joule after he observed that a sample of
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66.
67. Arc Welding
ARC WELDING
ME 353 Presentation 11–3–2000 Presented by Damon Ogden
OUTLINE
What is Arc Welding The four most common types Non destructive testing Design considerations
Strength Safety Feel free to ask questions at any questions at any time.
Arc Welding
Welcome to the world of WELDING
What is Arc Welding?
An electric arc between the and electrode and the work piece generates heat. Sufficient heat is
generated to melt the work pieces together.
ELECTRODE ARC WORK PIECES
Electricity
The range of welding current used can be from 5 to 500 amps. The voltage ranges from 20 to 30
volts, AC or DC. Both are determined by the material thickness. A 60 watt light bulb draws .5 amps.
Four Common Types of Welding ... Show more content on Helpwriting.net ...
Discuss some of factors that could affect the decision.
ANSWER TO PROBLEM 2
Answers included on page 5 of the handouts Material to be welded: –Some materials require special
processes that take more time and skill than others. Number of welds, or length of weld: –Some
welding processes are faster than others. –MIG/Flux core are fastest, then Stick, then TIG Weld bead
size: –Tig welding produces a smaller weld than mig or stick. If space is critical, then a small weld
bead is desirable.
PROBLEM 2 CONTINUED
Weld bead size: –Tig welding produces a smaller weld than mig or stick. If space is critical, then a
small weld bead is desirable. Location where welding is to occur: –See question one. Operator skill
level: –The four welding processes require different skill levels. TIG highest, MIG/Flux core lowest.
68. Albert Einstein once said: "Education is what remains when one has forgotten everything he
learned in school"
This concludes the
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69.
70. Implementation Of A New Fast Direct Torque Control...
Implementation of a new fast direct torque control algorithm for induction motor drive. Neha D.Bais
Mtech IPS in Electrical Engineering G.H.Raisoni college of Engineering ,Nagpur Email–
nehabais84@gmail.com J.G.Chaudhari Asst Prof Electrical Engineering G.H Raisoni college of
Engineering, Nagpur. Email– jagdish.choudhari@raisoni.net Abstract– The abstract DTC system
used for controlling of Induction motor gives robust as well as gives a high dynamic
performance.However it has two major drawbacks .The first one is the variation of switching
frequency in accordance with the amplitude of the hysteresis bands and the motor operating speed
,also the selection of voltage vectors is not optimized inside the flux hysteresis band to ... Show
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It is the simplest technique ,with good dynamic performance , robust and gives large benefits. It is
recognized as an alternative method to field oriented control (FOC). Industrial drives with DTC are
present in the market today.DTC is proposed to control electromagnetic torque and stator flux by
directly modifying the stator voltage in accordance with the torque and flux errors DTC has added
advantages over FOC absence of mechanical transducer, no requirement of co–ordinate
transformation ,and a very simple control scheme with less computational time Though DTC is
simple and have fast transient response, it generates high level common mode voltage variations. To
avoid the problems of common mode voltage variations a new DTC algorithm was developed, in
which, only odd or only even voltage vectors will be applied in each sector in which stator flux lies
without using any zero voltage vectors. However, this method gave torque ambiguity. To overcome
the torque ambiguity, modified DTC algorithm has been proposed The variable switching technique
is a part of the conventional DTC technique . It was firstly introduced by Takahashi and Noguchi
around 1980's this method is the wide band of the switching frequency of the inverter even when the
flux and torque references are kept constant. The conventional DTC scheme has some inherent
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71.
72. Onformational Dynamics Of Multi-Body Systems Essay
onformational dynamics of multi–body systems play critical roles in numerous chemical and
biological processes.1–9 For example, self–assembly provides a powerful tool to fabricate advanced
materials via a bottom–up approach in nanotechnology;1–7 precise recognition between drug
molecules and protein receptors is a key factor in drug discovery;8 and understanding protein
aggregation may pave the way for the development of therapeutics to treat neurodegenerative
diseases.9 Therefore, insights into the kinetics of these multi–body processes would greatly help to
advance our understanding in these important fields.However, dissecting the kinetic mechanisms of
multi–body processes is very challenging because they are rather complex and often ... Show more
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With a proper selection of the time interval, the continuous dynamics of a system can be simplified
as Markovian transitions among different conformational states to form an MSM. The TPT can then
be applied to identify transition pathways between a pair of states and further characterize their
properties such as the dominant pathways and the flux of individual ones. Recently, this approach
has been widely applied to study conformational dynamics of biomolecules by us52–57 and
others.28,32,51,58–62The direct application of TPT to multi–body systems may result in an
overwhelming number of pathways with comparable flux that hinders the understanding of multi–
body conformational dynamics. For example, one might need to consider more than 3000 parallel
pathways to account for 80% of total flux for the aggregation of two hydrophobic molecules in
water (see Fig. 1). In such case, even the most dominant pathway contributes only to 0.16% of the
total flux. This is in clear contrast to one–body systems, such as protein folding in
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73.
74. Modèles de Free Cash Flow
Modèles du Free Cash Flow Thèmes choisis en gestion – États financiers et placements (ADMI
3500) Les exemples sont tirés du livre : Stowe, J. D., Robinson, T.R., Pinto, J. E. et Henry , Equity
asset valuation, Second Edition, 2010, CFA Institute Investment Series 2 1. Introduction Les
modèles d'évaluation basés sur les flux monétaires actualisées (DCF model) considèrent la valeur
intrinsèque d'une action comme étant la valeur actualisée des flux monétaires espérés. Dans ce
chapitre les flux monétaires utilisés par les modèles d'évaluation sont : le free cash flow to the firm
(FCFF) et le free cash flow to equity (FCFE). Les dividendes représentent les flux monétaires
distribués aux actionnaires tandis que les free cash flow ... Show more content on Helpwriting.net ...
19 Préparé par François Boudreau 29/09/2010 22 Préparé par François Boudreau 29/09/2010
23 Préparé par François Boudreau 29/09/2010 7.2 Calculer le FCFF à partir de l'état des flux de
trésorerie. Les analystes utilisent souvent le flux monétaire opérationnel (CFO), tiré de l'état des flux
de trésorerie, comme point de départ pour calculer le free cash flow puisque le CFO incorpore les
ajustements pour les dépenses non–liquide et pour les investissements dans le fonds de roulement.
Faits à remarquer : les dépenses d'intérêt sont classés dans la section des flux monétaires provenant
des activités opérationnelles. Les dividendes payés aux actionnaires sont classés comme des
activités de financement. 24 Préparé par François Boudreau 29/09/2010 Pour estimer le FCFF à
partir du CFO, nous devons faire un ajustement avec les intérêts payés: FCFF =Flux monétaires
opérationnel (CFO) Plus : Intérêts x (1– taux d'imposition) Moins : Investissement en
immobilisations 25 Préparé par François Boudreau 29/09/2010 7.3 Calculer le FCFE à partir du
FCFF Le FCFE est le flux monétaire disponible aux actionnaires ordinaires – le flux monétaire qui
reste une fois les dépenses opérationnelles
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75.
76. Radiation Exposure Of Women And Children Essay
Three different independent studies involve ultraviolet exposure to cohorts of women and children.
The paper will use the following studies to determine if exposure to ultraviolet radiation is causal of
skin cancer. The first cohort study, Cumulative ultraviolet radiation flux in adulthood and risk of
incident skin cancers in women (Wu S, Han J, Vleugels RA, et al., 2014), is a prospective study
established in 1976 which follows a cohort of 121,700 registered nurses all of which filled out a
questionnaire with risks of chronic diseases. The cohort which was named NHS included
participants aged 30–55 years of age who resided within 11 different US states and by the
conclusion participants resided in every state with a follow–up rate of 96%. Disease was defined as
skin cancer and reported as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and
melanoma (Medical records only collected from those with BCC or melanoma). The exposure of
UV Flux (estimation of UVB radiation and UVA radiation) was estimated based on location of
participants and the annual UV flux data for a participant 's respective location.
The second cohort study, Sun damage in ultraviolet photographs correlates with phenotypic
melanoma risk factors in 12–year–old children (Gamble RG, Asdigian NL, Aalborg J, et al., 2011),
is a prospective study from 2011 which follows a cohort of 1,145 children ages 11–12 born from
January 1988 to September 1988. The children wore no sun protection, had their faces
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77.
78. Enlistment Engine Essay
There is wide range utilization of enlistment engine from railroad footing to modern application.
Adjustable speed drives (ASD) have discovered field orientated control (FOC) system as a perfect
contender for elite applications to supplant DC drives with AC drives attributable to their cost,
weight, unwavering quality and roughness. Different sensorless calculations for an enlistment
engine drive have been proposed for example, utilizing state conditions, Model Reference Adaptive
Systems(MRAS), Luenberger or Kalman–channel spectators, sliding mode control, saliency
impacts, reactive power, coordinate control of torque and flux, Artificial Intelligence(AI), thus on.
Among the procedures for speed sensorless control of IM proposed, the MRAS ... Show more
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Similarly R_s,L_s,R_r & L_r are the stator résistance, stator self inductance, rotor resistance and the
rotor self inductance. The rotor time constant is given as T_r=L_r/(R_r ) and leakage inductance as
σL_s where σ=1–〖L_m〗^2/(L_r L_s ). The convergence of estimated value in Eq. 2.1 and Eq. 2.2
to the actual value E can be assured with a suitable dynamic characteristic. It gives the following
objective function :– e=ψ_qr ψ_dr^e–ψ_qr^e
ψ_dr.................................................................................[2.5] Now the error in Eq. 2.5 is fed to an
adaptation mechanism in Eq. 2.3 and Eq. 2.4 that may be designed on the basis of PI controller,
neural network or fuzzy logic. Sensitivity towards parameter variation Sensitivity towards parameter
variation for different estimation techniques are given below:–
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