The document summarizes magnetohydrodynamic (MHD) simulations of the formation and ejection of magnetic flux ropes from the sun. It uses two models: a global non-linear force-free field model to simulate the slow formation of a flux rope over 19 days, and an MHD model to simulate the rapid ejection. The simulation shows the flux rope rising and ejecting plasma at speeds up to 100 km/s, consistent with observed coronal mass ejection speeds. Additional factors like gravity and fully simulating the flux rope evolution are discussed.
Synchrotron radiation is electromagnetic radiation emitted when charged particles travel along a curved path at relativistic speeds. The document discusses the historical background, design, components, and detection of synchrotron radiation. It also outlines the properties, advantages, and applications of synchrotron radiation, which include life sciences research, materials science, medical imaging, and cancer treatment. Synchrotron facilities around the world provide intense beams of synchrotron light for scientific experiments.
Introduction to elasticity part 1 of 2 is a presentation at undergraduate in science (physics, mathematics, engineering) level. For comments or improvement suggestions please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects please visit my website at http://www.solohermelin.com.
This presentation is in the Elasticity folder.
The document summarizes an upcoming race between 4 teams from different countries to race molecule-sized "nanocars" on a gold racetrack using a unique microscope with 4 independent scanning tunneling microscope tips at the CNRS's Centre d'élaboration de matériaux et d'études structurales in Toulouse, France. Each team will control their nanocar in an attempt to be the first to cross the finish line. Viewers can watch the 36-hour race live online.
1. The document outlines the key topics covered in a physics curriculum, including mechanics, waves and oscillations, optics, thermal physics, electricity and magnetism, modern physics, and electronics.
2. Key concepts in mechanics include motion, forces, energy, momentum, rotation, gravity, fluids, and relativity. Waves and oscillations covers simple harmonic motion, wave properties, sound, and ultrasound.
3. Optics discusses light propagation, interference, diffraction, polarization, lasers, and optical instruments. Thermal physics covers thermodynamics, heat engines, phase transitions, and kinetic theory of gases.
Aerodynamics Part II of 3 describes aerodynamics of bodies in supersonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
This document provides a table of contents for a document on optics. It outlines topics like Maxwell's equations, electromagnetic wave equations, geometrical optics, diffraction, and more. Key figures in the development of these topics are also mentioned, such as Maxwell, Helmholtz, Kirchhoff, and Fresnel. The document derives equations like the scalar Helmholtz differential equation and provides an overview of Fresnel-Kirchhoff diffraction theory.
Free space optical communication using orbital angular momentum multiplexing ...Emma Zhang
This document summarizes the history and applications of orbital angular momentum (OAM) in optical communication. It discusses key discoveries such as the identification of OAM in photons in 1932, the generation of helical beams using cylindrical lenses in 1992, and the first demonstration of free-space optical communication using OAM-multiplexed beams in 2004. More recent work has achieved terabit data transmission rates using OAM multiplexing combined with polarization multiplexing. OAM enables high-capacity communication by using the unlimited angular momentum states of each photon to encode information.
Synchrotron radiation is electromagnetic radiation emitted when charged particles travel along a curved path at relativistic speeds. The document discusses the historical background, design, components, and detection of synchrotron radiation. It also outlines the properties, advantages, and applications of synchrotron radiation, which include life sciences research, materials science, medical imaging, and cancer treatment. Synchrotron facilities around the world provide intense beams of synchrotron light for scientific experiments.
Introduction to elasticity part 1 of 2 is a presentation at undergraduate in science (physics, mathematics, engineering) level. For comments or improvement suggestions please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects please visit my website at http://www.solohermelin.com.
This presentation is in the Elasticity folder.
The document summarizes an upcoming race between 4 teams from different countries to race molecule-sized "nanocars" on a gold racetrack using a unique microscope with 4 independent scanning tunneling microscope tips at the CNRS's Centre d'élaboration de matériaux et d'études structurales in Toulouse, France. Each team will control their nanocar in an attempt to be the first to cross the finish line. Viewers can watch the 36-hour race live online.
1. The document outlines the key topics covered in a physics curriculum, including mechanics, waves and oscillations, optics, thermal physics, electricity and magnetism, modern physics, and electronics.
2. Key concepts in mechanics include motion, forces, energy, momentum, rotation, gravity, fluids, and relativity. Waves and oscillations covers simple harmonic motion, wave properties, sound, and ultrasound.
3. Optics discusses light propagation, interference, diffraction, polarization, lasers, and optical instruments. Thermal physics covers thermodynamics, heat engines, phase transitions, and kinetic theory of gases.
Aerodynamics Part II of 3 describes aerodynamics of bodies in supersonic flight.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
This document provides a table of contents for a document on optics. It outlines topics like Maxwell's equations, electromagnetic wave equations, geometrical optics, diffraction, and more. Key figures in the development of these topics are also mentioned, such as Maxwell, Helmholtz, Kirchhoff, and Fresnel. The document derives equations like the scalar Helmholtz differential equation and provides an overview of Fresnel-Kirchhoff diffraction theory.
Free space optical communication using orbital angular momentum multiplexing ...Emma Zhang
This document summarizes the history and applications of orbital angular momentum (OAM) in optical communication. It discusses key discoveries such as the identification of OAM in photons in 1932, the generation of helical beams using cylindrical lenses in 1992, and the first demonstration of free-space optical communication using OAM-multiplexed beams in 2004. More recent work has achieved terabit data transmission rates using OAM multiplexing combined with polarization multiplexing. OAM enables high-capacity communication by using the unlimited angular momentum states of each photon to encode information.
The letter encourages Alicia not to be scared and to keep going, while also asking her not to criticize how bad the writing is. The author, who signs as "your little Kangaroo", says they discovered the place they wanted to go and believes it is their destiny to be with Alicia, expressing their love for her.
1) A hydro-geophysical investigation was conducted at a closed landfill site in southwestern Ontario, Canada to map the distribution of landfill leachate and subsurface geology.
2) Electromagnetic and resistivity surveys revealed an anomalous high-conductivity zone in the western half of the site, indicating the presence of landfill leachate in the upper aquifer and partially in the underlying silt/sand aquitard. No contamination was detected in the lower sand aquifer.
3) Hydrological modeling predicted that the landfill leachate plume will occupy the entire upper aquifer and most of the silt/sand aquitard within 1000 years, but the lower sand aquifer will remain
The entrepreneurial spirit is an attribute for the development of individual and society. More importantly, entrepreneurship development becomes a vehicle for transforming lives in underdeveloped regions. Community-centered entrepreneurship models have got much more relevance in positively contributing to community development. In this context, Bala Vikasa through Vikasa International Center is deploying its experiences and expertise among youth and women in promoting entrepreneurship in rural areas.
William McKinley was the 25th President of the United States, serving from 1897 until his assassination in 1901. As president, he led the country to victory in the Spanish-American War, raised protective tariffs to promote industry, and maintained the gold standard. McKinley previously served as a congressman from Ohio where he specialized in tariff policy and championed a controversial tariff bill.
A draft Environmental Impact Statement issued by the Federal Energy Regulatory Commission (FERC) for the 255-mile NEXUS natural gas pipeline, set to run across the state of Ohio to Michigan. The project's main sponsor is Spectra Energy.
This document discusses whether the [Mg/Fe] ratio is a good proxy for galaxy formation timescales. It finds that while [Mg/Fe] has traditionally been used as such a proxy, taking into account the non-universal initial mass function (IMF) observed in massive galaxies leads to unrealistic short formation timescales calculated from their [Mg/Fe] ratios. The document considers scenarios where the IMF varies with stellar population or evolves over time to potentially resolve this issue, but notes more observation of galaxies forming at high redshift is needed to better understand their chemical evolution. It concludes one must be careful interpreting [Mg/Fe] alone as a tracer of galaxy formation timescales.
High-affinity interactions between antigenic peptides and heat shock protein 70 (HSP70) can enhance CD8+ T cell immune responses. A novel higher-affinity HSP70-binding sequence called J1 was introduced, which significantly improved binding of peptides to HSP70. The OVA peptide SIINFEKL modified with J1 showed a 15-fold higher affinity for HSP70 compared to the original J0 sequence. Additionally, changing the orientation and adding a cleavable linker between the binding sequence and epitope further increased immunogenicity, demonstrating enhanced immune responses with multiple mouse and human epitopes. These modified epitopes complexed with HSP70 have potential for creating successful multivalent vaccines against infectious diseases and
La Web 2.0 permite a los usuarios participar activamente en la creación y distribución de contenido en lugar de ser solo consumidores pasivos. Esto ha llevado al auge de blogs, redes sociales y otras herramientas que facilitan la interacción y colaboración entre usuarios. Las redes sociales ahora se utilizan ampliamente en educación, ya que permiten a estudiantes y profesores compartir información y recursos educativos de manera más interactiva.
Mayores logros de manuel elkin patarroyosarmientoe
El documento resume los mayores logros de Manuel Elkin Patarroyo, incluyendo el desarrollo en 1984 de una vacuna sintética contra la malaria llamada SPf 66, la donación de esta vacuna a la OMS en 1993, y sus investigaciones sobre marcadores genéticos para enfermedades como la lepra y tuberculosis en el Instituto de Inmunología que fundó en la Universidad Nacional.
The document profiles three successful community banks in South Florida - Apollo Bank, Banesco USA, and Stonegate Bank. It discusses their histories, growth strategies, financial performance, and goals for future expansion. Apollo Bank focuses on entrepreneurs and small businesses in Miami-Dade. Banesco USA is growing through acquisitions and loans while expanding in Miami-Dade, Broward, and Puerto Rico. Stonegate Bank aims to be the primary bank for businesses and has expanded its branch network across South Florida through acquisitions and organic growth. All three banks have achieved strong financial results and high ratings.
Steven A. Ballmer certified MUNESHWAR P DUTT as a Microsoft Certified Technology Specialist in Microsoft Dynamics NAV 2009 Trade and Inventory. Dutt completed the requirements for this certification on March 06, 2013 and was assigned certification number E192-7535.
Este documento presenta información sobre la gonorrea y la sífilis, dos enfermedades de transmisión sexual. Explica las causas, síntomas y métodos de prevención de ambas enfermedades. También destaca los riesgos de no tratar estas infecciones y la necesidad de concientizar a la población sobre la prevención de enfermedades de transmisión sexual.
1) Flux ropes play an important role in space weather as they are embedded within coronal mass ejections (CMEs) and drive geomagnetic storms when impacting Earth's magnetosphere.
2) CMEs have a multipart structure that includes an embedded flux rope, which appears as a dark cavity in white light observations and is measured in situ as a magnetic cloud.
3) Flux ropes evolve as they propagate through the solar system, experiencing deflections towards the solar equatorial plane and rotations to align with the heliospheric current sheet.
1. The document discusses magnetic circuits, including definitions of magnetic flux, magneto motive force, and reluctance.
2. An analogy is drawn between electric circuits and magnetic circuits, with magneto motive force, flux, and reluctance corresponding to current, voltage, and resistance.
3. Various magnetic circuit elements are analyzed including series, parallel, and coupled circuits.
Comisso - Plasmoid Instability in Time-Evolving Current SheetsLuca Comisso
We formulate a principle of least time [1] that enables us to determine the properties of the reconnecting current sheet (aspect ratio and elapsed time) and the plasmoid instability (growth rate, wavenumber, inner layer width) at the end of the linear phase. After this phase the reconnecting current sheet is disrupted and fast magnetic reconnection can occur.
[1] L. Comisso, M. Lingam, Y.-M. Huang, A. Bhattacharjee, Phys. Plasmas 23, 100702 (2016).
This document summarizes research on plasma disruptions in tokamak machines. It discusses three key topics:
1) The impact of runaway electrons during plasma disruptions, finding that they can damage internal components and convert significant magnetic field energy into kinetic energy.
2) Methods for detecting instabilities like MARFEs in real-time using video systems and the relationship between MARFEs and gas puffing.
3) Measurements of the electron temperature evolution during current quenches using diagnostic systems, finding an initial m/n=1/1 erosion pattern and that runaway electrons are generated.
The document summarizes research on a proposed plasma magnet propulsion concept. Key points:
1) Experiments at the University of Washington generated and sustained up to 10kA of plasma current using a rotating magnetic field, enough to inflate a plasma bubble similar to a mini-magnetosphere.
2) Measurements found electron temperatures of 18eV and densities sufficient to sustain particle confinement for over a year within an inflated 100km plasma bubble.
3) Numerical simulations modeled self-consistent electron motion within experimental rotating dipole fields and plasma inflation dynamics, supporting the feasibility of the plasma magnet concept for deep space exploration propulsion.
The letter encourages Alicia not to be scared and to keep going, while also asking her not to criticize how bad the writing is. The author, who signs as "your little Kangaroo", says they discovered the place they wanted to go and believes it is their destiny to be with Alicia, expressing their love for her.
1) A hydro-geophysical investigation was conducted at a closed landfill site in southwestern Ontario, Canada to map the distribution of landfill leachate and subsurface geology.
2) Electromagnetic and resistivity surveys revealed an anomalous high-conductivity zone in the western half of the site, indicating the presence of landfill leachate in the upper aquifer and partially in the underlying silt/sand aquitard. No contamination was detected in the lower sand aquifer.
3) Hydrological modeling predicted that the landfill leachate plume will occupy the entire upper aquifer and most of the silt/sand aquitard within 1000 years, but the lower sand aquifer will remain
The entrepreneurial spirit is an attribute for the development of individual and society. More importantly, entrepreneurship development becomes a vehicle for transforming lives in underdeveloped regions. Community-centered entrepreneurship models have got much more relevance in positively contributing to community development. In this context, Bala Vikasa through Vikasa International Center is deploying its experiences and expertise among youth and women in promoting entrepreneurship in rural areas.
William McKinley was the 25th President of the United States, serving from 1897 until his assassination in 1901. As president, he led the country to victory in the Spanish-American War, raised protective tariffs to promote industry, and maintained the gold standard. McKinley previously served as a congressman from Ohio where he specialized in tariff policy and championed a controversial tariff bill.
A draft Environmental Impact Statement issued by the Federal Energy Regulatory Commission (FERC) for the 255-mile NEXUS natural gas pipeline, set to run across the state of Ohio to Michigan. The project's main sponsor is Spectra Energy.
This document discusses whether the [Mg/Fe] ratio is a good proxy for galaxy formation timescales. It finds that while [Mg/Fe] has traditionally been used as such a proxy, taking into account the non-universal initial mass function (IMF) observed in massive galaxies leads to unrealistic short formation timescales calculated from their [Mg/Fe] ratios. The document considers scenarios where the IMF varies with stellar population or evolves over time to potentially resolve this issue, but notes more observation of galaxies forming at high redshift is needed to better understand their chemical evolution. It concludes one must be careful interpreting [Mg/Fe] alone as a tracer of galaxy formation timescales.
High-affinity interactions between antigenic peptides and heat shock protein 70 (HSP70) can enhance CD8+ T cell immune responses. A novel higher-affinity HSP70-binding sequence called J1 was introduced, which significantly improved binding of peptides to HSP70. The OVA peptide SIINFEKL modified with J1 showed a 15-fold higher affinity for HSP70 compared to the original J0 sequence. Additionally, changing the orientation and adding a cleavable linker between the binding sequence and epitope further increased immunogenicity, demonstrating enhanced immune responses with multiple mouse and human epitopes. These modified epitopes complexed with HSP70 have potential for creating successful multivalent vaccines against infectious diseases and
La Web 2.0 permite a los usuarios participar activamente en la creación y distribución de contenido en lugar de ser solo consumidores pasivos. Esto ha llevado al auge de blogs, redes sociales y otras herramientas que facilitan la interacción y colaboración entre usuarios. Las redes sociales ahora se utilizan ampliamente en educación, ya que permiten a estudiantes y profesores compartir información y recursos educativos de manera más interactiva.
Mayores logros de manuel elkin patarroyosarmientoe
El documento resume los mayores logros de Manuel Elkin Patarroyo, incluyendo el desarrollo en 1984 de una vacuna sintética contra la malaria llamada SPf 66, la donación de esta vacuna a la OMS en 1993, y sus investigaciones sobre marcadores genéticos para enfermedades como la lepra y tuberculosis en el Instituto de Inmunología que fundó en la Universidad Nacional.
The document profiles three successful community banks in South Florida - Apollo Bank, Banesco USA, and Stonegate Bank. It discusses their histories, growth strategies, financial performance, and goals for future expansion. Apollo Bank focuses on entrepreneurs and small businesses in Miami-Dade. Banesco USA is growing through acquisitions and loans while expanding in Miami-Dade, Broward, and Puerto Rico. Stonegate Bank aims to be the primary bank for businesses and has expanded its branch network across South Florida through acquisitions and organic growth. All three banks have achieved strong financial results and high ratings.
Steven A. Ballmer certified MUNESHWAR P DUTT as a Microsoft Certified Technology Specialist in Microsoft Dynamics NAV 2009 Trade and Inventory. Dutt completed the requirements for this certification on March 06, 2013 and was assigned certification number E192-7535.
Este documento presenta información sobre la gonorrea y la sífilis, dos enfermedades de transmisión sexual. Explica las causas, síntomas y métodos de prevención de ambas enfermedades. También destaca los riesgos de no tratar estas infecciones y la necesidad de concientizar a la población sobre la prevención de enfermedades de transmisión sexual.
1) Flux ropes play an important role in space weather as they are embedded within coronal mass ejections (CMEs) and drive geomagnetic storms when impacting Earth's magnetosphere.
2) CMEs have a multipart structure that includes an embedded flux rope, which appears as a dark cavity in white light observations and is measured in situ as a magnetic cloud.
3) Flux ropes evolve as they propagate through the solar system, experiencing deflections towards the solar equatorial plane and rotations to align with the heliospheric current sheet.
1. The document discusses magnetic circuits, including definitions of magnetic flux, magneto motive force, and reluctance.
2. An analogy is drawn between electric circuits and magnetic circuits, with magneto motive force, flux, and reluctance corresponding to current, voltage, and resistance.
3. Various magnetic circuit elements are analyzed including series, parallel, and coupled circuits.
Comisso - Plasmoid Instability in Time-Evolving Current SheetsLuca Comisso
We formulate a principle of least time [1] that enables us to determine the properties of the reconnecting current sheet (aspect ratio and elapsed time) and the plasmoid instability (growth rate, wavenumber, inner layer width) at the end of the linear phase. After this phase the reconnecting current sheet is disrupted and fast magnetic reconnection can occur.
[1] L. Comisso, M. Lingam, Y.-M. Huang, A. Bhattacharjee, Phys. Plasmas 23, 100702 (2016).
This document summarizes research on plasma disruptions in tokamak machines. It discusses three key topics:
1) The impact of runaway electrons during plasma disruptions, finding that they can damage internal components and convert significant magnetic field energy into kinetic energy.
2) Methods for detecting instabilities like MARFEs in real-time using video systems and the relationship between MARFEs and gas puffing.
3) Measurements of the electron temperature evolution during current quenches using diagnostic systems, finding an initial m/n=1/1 erosion pattern and that runaway electrons are generated.
The document summarizes research on a proposed plasma magnet propulsion concept. Key points:
1) Experiments at the University of Washington generated and sustained up to 10kA of plasma current using a rotating magnetic field, enough to inflate a plasma bubble similar to a mini-magnetosphere.
2) Measurements found electron temperatures of 18eV and densities sufficient to sustain particle confinement for over a year within an inflated 100km plasma bubble.
3) Numerical simulations modeled self-consistent electron motion within experimental rotating dipole fields and plasma inflation dynamics, supporting the feasibility of the plasma magnet concept for deep space exploration propulsion.
Future Devices: Update on the Plasma wireEuro CTO Club
1) Plasma mediated ablation (PMA) uses plasma created by applying energy to electrodes to break down intramolecular bonds in soft tissue without high temperatures.
2) PMA shows potential for recanalizing chronic total occlusions (CTOs) in an antegrade approach using streamers to penetrate distal caps.
3) A representative case demonstrated successful penetration of a distal CTO cap using an antegrade PMA approach with dual wires to create streamers and ablate tissue.
Michael Faraday discovered electromagnetic induction in 1831, demonstrating that a changing magnetic field generates an electric current. This discovery led to modern electric technologies like motors, generators, and transformers. Faraday's law was later incorporated into Maxwell's equations, which unified electricity and magnetism. According to Faraday's law of induction, a changing magnetic field induces an electric current in a nearby conductor. Moving a magnet in and out of a wire loop or rotating a loop in a magnetic field can generate an alternating current. This effect is exploited in electric generators and motors.
Continuum emission from within the plunging region of black hole discsSérgio Sacani
The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a
powerful probe of the mass and spin of the central black hole. The vast majority of existing ‘continuum fitting’ models neglect
emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however,
find non-zero emission sourced from these regions. In this work, we extend existing techniques by including the emission
sourced from within the plunging region, utilizing new analytical models that reproduce the properties of numerical accretion
simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component,
but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component
has been added in by hand in an ad hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum
of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional
models that neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of
intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820 + 070 black hole spin
which must be low a• < 0.5 to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission
component in the MAXI J1820 + 070 spectrum between 6 and 10 keV, highlighting the necessity of including this region. Our
continuum fitting model is made publicly available.
Lectio Praecursoria from PhD defence (2014)Alexey Isavnin
This document discusses flux ropes in space plasmas. It summarizes that coronal mass ejections are multipart structures that often contain embedded flux ropes. It describes how solar flux ropes evolve as they travel through space, undergoing deflections and rotations. It also discusses how flux ropes form and evolve in the Earth's magnetosphere, including their role in substorm dynamics and plasmoid formation between reconnection sites.
Analysis of LENR and Recommendations for Cold Fusion Energy Using the BSM-SG ...Stoyan Sarg Sargoytchev
The fast growing branches of nanotechnology permitted advancements in different fields. Among them is the recent success in LENR. This requires a new theoretical understanding for processes in atomic sub-nanometric scale. The atomic models derived in the Basic Structures of Matter Supergravitation Unified Theory (BSM-SG), denoted as the BSM-SG models, fit quite well to this need. The BSM-SG theory reveals the existence of a space microcurvature surrounding the elementary particles and the superdense atomic nuclei. This explains why quantum mechanical models work only with energy levels and not with the dimension of length. The re-examination of scattering experiments from the BSM-SG point of view reveals a complex three-dimensional nuclear structure different from the quantum mechanical models of atoms based on the Bohr atomic model. Protons and neutrons are not point-like; the atomic nuclei have a much larger overall size, so the Coulomb barrier is not so strong. Therefore, some nuclear transmutations are possible at accessible temperatures. The pattern of the Periodic Table carries a strong signature of the spatial arrangement of protons and neutrons in the atomic nuclei. Nuclear stability depends on the symmetrical arrangement of protons and neutrons. Nuclear spin and nuclear magnetic resonance are also identifiable features of the nuclear configuration. The BSM-SG atomic models provide a new opportunity for analysis and prediction of many nuclear transmutations in the field of LENR. This issue is presented in the author’s book “Structural Physics of Nuclear Fusion”. The book describes a new method for theoretical estimation of the binding nuclear energy based on the derived nuclear dimensions of hadrons and derived strong force parameters. This provides new considerations for the proper selection of isotopes suitable for realization of cold fusion energy with minimal or no radioactive waste.
This document provides an overview of magnetism and magnetic fields. It begins with an introductory activity on magnetism facts. The document then outlines topics to be covered, including magnetic fields, forces on moving charges and currents, and properties of electromagnets and ferromagnets. Examples are provided to demonstrate how to calculate magnetic field strength and forces. The key points are that magnets produce magnetic fields with north and south poles; magnetic fields exert forces on moving charges; and currents generate magnetic fields according to Ampere's law.
2014 NJP - Oscillatory solitons and time-resolved phase locking of two polari...Guilherme Tosi
This document summarizes time-resolved measurements of two polariton condensates formed in a semiconductor microcavity under nonresonant excitation. The measurements directly observe oscillatory behavior as dark or bright soliton-like waves form between the excitation spots. They also observe phase locking of the two initially independent condensates over time. These phenomena provide insights into the underlying dynamics of polariton-polariton interactions and propagation of polariton condensates.
This document provides an introduction to magnetic levitation and its applications. It discusses the basic principles of magnetism and how magnetic fields are created. It then explains the different types of magnetic levitation, including using permanent magnets, electromagnets, and superconductive magnets. Applications of magnetic levitation that are discussed include novelty toys like levitating globes, fast food toys, and high-speed train transportation systems. Magnetic levitation for trains uses electromagnetic forces from superconducting magnets on the train and coils on the track to both levitate and provide lateral guidance for the train as it moves.
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.
The document summarizes the first observations of the magnetic Kelvin-Helmholtz instability in the solar corona using high-resolution imaging from NASA's Solar Dynamics Observatory. The instability was detected on the northern flank of a fast coronal mass ejection, appearing as substructures or waves against the darker coronal background. Analysis found the observed phase speed of the waves to be about half the speed of the ejecta front, validating theories of the non-linear dynamics of this instability in magnetized plasma environments. The findings provide new insights into fundamental plasma processes in the solar atmosphere and solar-terrestrial system.
PERFORMANCE OF HYBRID ELECTROMAGNETIC DAMPER FOR VEHICLE SUSPENSIONijiert bestjournal
Suspension systems, in the automotive application context, have been designed to maintain
contact between a vehicle’s tires and the road, and to isolate the frame of the vehicle from road
disturbances. Dampers, or so-called shock absorbers, as the undeniable heart of suspension
systems, reduce the effect of a sudden bump by smoothing out the shock. In most shock
absorbers, the energy is converted into heat via viscous fluid. In hydraulic cylinders, the
hydraulic fluid is heated up. In air cylinders, the hot air is emitted into the atmosphere. There are
several common approaches for shock absorption, including material hysteresis, dry friction,
fluid friction, compression of gas, and eddy currents.
1. Electromagnetic induction is the phenomenon by which a changing magnetic field induces an electromotive force (emf) in a conductor. Experiments by Michael Faraday and Joseph Henry in the 1830s demonstrated this effect and established its laws.
2. Faraday's experiments showed that a changing magnetic flux induces a current in a coil. He placed coils inside changing magnetic fields from moving magnets and observed induced currents.
3. Lenz's law defines the direction of induced current: the current flows such that its magnetic field opposes the change that caused it. This ensures the conservation of energy.
Umklapp Scattering and the Hall Effect are discussed. Umklapp Scattering is the inelastic scattering of photons that results in phonon emission or absorption. The Hall Effect is the production of a voltage difference across a conductor when a magnetic field is applied perpendicular to the current. Conservation of wave vector, momentum, and energy must be satisfied in Umklapp Scattering. The Hall voltage is proportional to the magnetic field and current, and is used in applications like sensors and displacement transducers.
Similar to magnetohydrodynamic_simulation_of_the_ejection_of_magnetic_flux_rope (20)
1. Magnetohydrodynamic simulations of the ejection of a
magnetic flux rope
Akinsanmi A. Babatunde
Department of Astronomy
University of Porto
Paper by Pagano et al (2013)
AST 4005, January 2016
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 1 / 27
2. Outline
1 INTRODUCTION
2 MOTIVATION
3 BACKGROUND
4 MODEL
5 DISCUSSION AND SUMMARY
6 CONCLUSION
7 REFERENCES
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 2 / 27
3. INTRODUCTION
Introduction
Coronal mass ejections (CMEs) are one of the most violent
phenomena found on the Sun. One model to explain their occurrence
is the flux rope ejection model.
CMEs are huge clouds of plasma and magnetic fileds occasionally
thrown off from the sun which pose threats to earth and space based
technology.
Within each CME is a kernel of tightly wound group of magnetic field
lines called flux ropes that can contain and transport solar materials.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 3 / 27
4. INTRODUCTION
Flux Rope Formation
Credit: NASA / GSFC
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 4 / 27
5. MOTIVATION
Motivation
Flux rope ejections are believed to be one of the main progenitors of
CMEs.
Investigate whether magnetic flux ropes during its evolution, can
erupt to produce a CME.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 5 / 27
6. BACKGROUND
Categories
The flux rope ejection model may itself be split into two categories:
Flux ropes formed quasi-statically from perturbations of already
existing coronal arcades.
Flux ropes formed dynamically during the emergence of magnetic flux.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 6 / 27
7. BACKGROUND
Quasi-statically formed Flux ropes
Undergoes three separate stages of evolution: the formation, equilibrium
and eruption phases.
FORMATION: flux rope forms over time periods of days to weeks as
a coronal arcade is perturbed by photospheric motions and flux
cancellation at a Polarity Inversion Line (PIL).
EQUILIBRIUM: period during which the flux rope lies in near
equilibrium with its surroundings.
ERUPTION: where the flux rope loses equilibrium and is ejected out
of the solar corona over a few hours due to magnetic forces.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 7 / 27
8. MODEL
Model
The wide variety of time scales involved, in the formation of the flux
rope and then its eruption, poses a considerable challenge to
theoretical models.
The Model is to simulate the whole life span of a flux rope from slow
formation to rapid ejection and investigate if it leads to fast ejection
of plasma.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 8 / 27
9. MODEL
Models Employed
Global Non-Linear Force-Free Field (GNLFFF) model ( Mackay & van
Ballegooijen, 2006a)
Full MHD approach using ARMVAC code (KU Leuven)
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 9 / 27
10. MODEL
GNLFFF
GNLFFF model produces flux ropes by means of the relative motion
and interaction of two magnetic bipoles (one more tilted than the
other with respect to the equator).
As a result of flux cancellation, a flux rope forms above the PIL of the
more tilted bipole after 19 days of evolution as shown in fig 1
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 10 / 27
11. MODEL
flux rope formed from GNLFFF
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 11 / 27
12. MODEL
ARMVAC CODE
We adopt the stressed non-potential magnetic field that exists on this
day as the initial magnetic field condition for numerical MHD
simulations using ARMVAC that follows the dynamics of the eruption.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 12 / 27
13. MODEL
Coupling the Models
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 13 / 27
14. MODEL
Equations
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 14 / 27
15. MODEL
Initial configuration for MHD Simulation
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 15 / 27
16. MODEL
Simulating erupting flux rope
Alfven time τAlf = 120s
At t = 0τAlf , the positive Lorentz force present underneath the flux rope
pushes the flux rope and the plasma contained within it upwards and it
immediately starts to rise.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 16 / 27
17. MODEL
Simulating erupting flux rope
As the flux rope moves up, a horizontal Lorentz force acts below the flux
rope to push oppositely oriented magnetic field lines on either side of the
PIL towards the PIL
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 17 / 27
18. MODEL
Simulating erupting flux rope
Shows plasma being ejected outwards with velocity greater than 8x106 due
to radial Lorentz force and reconnection of MF lines below the flux rope
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 18 / 27
19. MODEL
Between t = 0 & t = 17.40τAlf
Arcades above bipole remain largely unchanged
Dense plasma is ejected outwards by motion of flux rope and tied to
magnetic configuration
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 19 / 27
20. MODEL
After t = 17.40τAlf to end of simulation t = 70τAlf
The ejected flux rope starts to interact/reconnect with the overlying
magnetic field
Magnetic field configuration becomes significantly more complex and
coherence of plasma decreases
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 20 / 27
21. MODEL
flux rope ejection
At t = 70τAlf , the ejection reaches the upper boundary and the dynamics
of the simulation are no longer followed.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 21 / 27
22. MODEL
ejection of plasma
As flux rope moves up, plasma is displaced.
The front starts from a height of 1.3R and is accelerated by the ejecting
magnetic flux rope. The average speed of the front is about 100 kms1
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 22 / 27
23. DISCUSSION AND SUMMARY
Discussion and Summary
We have modeled the slow formation of flux rope through quasi-static
approximation and its rapid ejection through a full MHD simulation
no additional shearing or stress of the magnetic field is carried out in
the MHD simulation, where the resulting dynamics are solely a result
of the stress built up between the two bipoles during the slow
evolution
Flux rope rises and coronal plasma follow magnetic field evolution and
is expelled out at 2.5R
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 23 / 27
24. DISCUSSION AND SUMMARY
Additional Considerations
Effect of gravity
Implementing only the MHD model for the entire flux rope evolution
Feasibility of a post-eruption MHD state
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 24 / 27
25. CONCLUSION
conclusion
The simulation of evolution of the flux rope shows that plasma
expelled during the flux rope ejection travels outward at a speed of
100 kms-1, which is consistent with the observed speed of CMEs in
the low corona.
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 25 / 27
26. REFERENCES
Reference
Mackay, D. H., & van Ballegooijen, A. A. 2006a, ApJ, 641, 577
Keppens, R., Meliani, Z., van Marle, A. J., et al. 2012, J. Comput.
Phys., 231, 718
Liu, R., Liu, C., Wang, S., Deng, N., Wang, H. 2010, ApJ, 725, L84
Akinsanmi A. Babatunde (University of Porto)Magnetohydrodynamic simulations of the ejection of a magnetic flux ropeAST 4005, January 2016 26 / 27