In electromagnetism and electronics, electromotive force (emf, denoted and measured in volts)[1] is the electrical action produced by a non-electrical source.[2]Devices (known as transducers) provide an emf[3] by converting other forms of energy into electrical energy,[3] such as batteries (which convert chemical energy) or generators (which convert mechanical energy).[2] Sometimes an analogy to water pressure is used to describe electromotive force.[4] (The word "force" in this case is not used to mean forces of interaction between bodies).
In electromagnetic induction, emf can be defined around a closed loop of conductor as the electromagnetic work that would be done on an electric charge (an electron in this instance) if it travels once around the loop.[5] For a time-varying magnetic flux linking a loop, the electric potential's scalar field is not defined due to a circulating electric vector field, but an emf nevertheless does work that can be measured as a virtual electric potential around the loop.[6]
In the case of a two-terminal device (such as an electrochemical cell) which is modeled as a Thévenin's equivalent circuit, the equivalent emf can be measured as the open-circuit potential difference, or voltage, between the two terminals. This potential difference can drive an electric current if an external circuit is attached to the terminals, in which case the device becomes the voltage source of that circuit.
https://en.wikipedia.org/wiki/Electromotive_force
https://en.wikipedia.org/wiki/Electrical_energy
https://en.wikipedia.org/wiki/Transducer
https://en.wikipedia.org/wiki/Electromotive_force
https://en.wikipedia.org/wiki/Chemical_energy
https://en.wikipedia.org/wiki/Mechanical_energy
https://en.wikipedia.org/wiki/Van_de_Graaff_generator
https://en.wikipedia.org/wiki/Volt#Water-flow_analogy
https://en.wikipedia.org/wiki/Geomagnetic_storm
https://en.wikipedia.org/wiki/Voltage_source
https://en.wikipedia.org/wiki/Chemical_bond
https://en.wikipedia.org/wiki/Electrolyte
https://en.wikipedia.org/wiki/Electrode
https://en.wikipedia.org/wiki/Electric_current
https://en.wikipedia.org/wiki/Galvanic_cell
https://en.wikipedia.org/wiki/Electric_potential
https://en.wikipedia.org/wiki/Scalar_field
https://en.wikipedia.org/wiki/Conjugate_variables_(thermodynamics)
https://en.wikipedia.org/wiki/Electromagnetic_induction
https://en.wikipedia.org/wiki/loop
https://en.wikipedia.org/wiki/Launch_loop
https://en.wikipedia.org/wiki/Maglev
https://en.wikipedia.org/wiki/Linear_induction_motor
https://en.wikipedia.org/wiki/Maglev
https://en.wikipedia.org/wiki/Alternating_current
https://en.wikipedia.org/wiki/Perturbed_angular_correlation
https://en.wikipedia.org/wiki/Degrees_of_freedom_(physics_and_chemistry)
https://en.wikipedia.org/wiki/Astrophysical_jet
https://en.wikipedia.org/wiki/Christian_Friedrich_Schönbei
https://en.wikipedia.org/wiki/Robert_Bunsen
https://en.wikipedia.org/wiki/Accumulator_(energy)
https://en.wikipedia.org/wiki/Escape_velocity
https://en.wikipedia.org/wiki/Aircraft_catapult#Steam_catapult
https://en.wikipedia.org/wiki/Linear_stage
https://en.wikipedia.org/wiki/Category:Magnetic_propulsion_devices
https://en.wikipedia.org/wiki/Magnetostatics
https://en.wikipedia.org/wiki/Compressible_flow
https://en.wikipedia.org/wiki/Cryptand
https://en.wikipedia.org/wiki/Pnictogen_hydride
https://en.wikipedia.org/wiki/Synchronous_motor
https://en.wikipedia.org/wiki/Electrodynamic_suspension#Levitation_melting
https://en.wikipedia.org/wiki/Linear_stage
https://en.wikipedia.org/wiki/Accumulator_(energy)
https://en.wikipedia.org/wiki/Conformational_isomerism
https://en.wikipedia.org/wiki/Stereoisomerism
https://en.wikipedia.org/wiki/Isomer
https://en.wikipedia.org/wiki/Structural_isomer
https://en.wikipedia.org/wiki/Mirror_image
https://en.wikipedia.org/wiki/chirality
https://en.wikipedia.org/wiki/Enantiomer
https://en.wikipedia.org/wiki/Mirror_image
https://en.wikipedia.org/wiki/Infinity
https://en.wikipedia.org/wiki/infinite_divisibility
https://en.wikipedia.org/wiki/Zero
https://en.wikipedia.org/wiki/Stereocenter
https://en.wikipedia.org/wiki/Methoxypropane
https://en.wikipedia.org/wiki/Microwave_spectroscopy
https://en.wikipedia.org/wiki/Pressure
https://en.wikipedia.org/wiki/Chemical_bond
https://en.wikipedia.org/wiki/Chemical_structure
https://en.wikipedia.org/wiki/Molecular_geometry
https://en.wikipedia.org/wiki/Dihedral_angle#In_stereochemistry
https://en.wikipedia.org/wiki/Molecular_geometry
https://en.wikipedia.org/wiki/Torsion_of_a_curve
https://en.wikipedia.org/wiki/Torsion_(mechanics)
https://en.wikipedia.org/wiki/Torque
https://en.wikipedia.org/wiki/Lever
https://en.wikipedia.org/wiki/Pendulum
https://en.wikipedia.org/wiki/Spring_(mathematics)
https://en.wikipedia.org/wiki/Tractrix
https://en.wikipedia.org/wiki/Spiral
https://en.wikipedia.org/wiki/Matrix
https://en.wikipedia.org/wiki/Junction
https://en.wikipedia.org/wiki/Point_particle
https://en.wikipedia.org/wiki/Line
https://en.wikipedia.org/wiki/Bond
https://en.wikipedia.org/wiki/Rate
https://en.wikipedia.org/wiki/Measure
https://en.wikipedia.org/wiki/Calibration
https://en.wikipedia.org/wiki/Pressure
https://en.wikipedia.org/wiki/Quantity
https://en.wikipedia.org/wiki/Volume
https://en.wikipedia.org/wiki/Space
https://en.wikipedia.org/wiki/Time
https://en.wikipedia.org/wiki/Warp
https://en.wikipedia.org/wiki/Variable
https://en.wikipedia.org/wiki/Temperature
https://en.wikipedia.org/wiki/Charge
https://en.wikipedia.org/wiki/Voltage
https://en.wikipedia.org/wiki/Tension
https://en.wikipedia.org/wiki/Force
https://en.wikipedia.org/wiki/Torque
https://en.wikipedia.org/wiki/acceleration
https://en.wikipedia.org/wiki/angular_acceleration
https://en.wikipedia.org/wiki/circular_motion
https://en.wikipedia.org/wiki/threshold
https://en.wikipedia.org/wiki/just_noticeable_difference
https://en.wikipedia.org/wiki/excission
https://en.wikipedia.org/wiki/cascade
https://en.wikipedia.org/wiki/probability
https://en.wikipedia.org/wiki/chain_reaction
https://en.wikipedia.org/wiki/nuclear
https://en.wikipedia.org/wiki/nuclear_transmutation
https://en.wikipedia.org/wiki/gas
https://en.wikipedia.org/wiki/hydroelectric
https://en.wikipedia.org/wiki/hydrogen
https://en.wikipedia.org/wiki/particle
https://en.wikipedia.org/wiki/electron
https://en.wikipedia.org/wiki/electron_density_function
https://en.wikipedia.org/wiki/Atomic_orbital
https://en.wikipedia.org/wiki/Escape_velocity
In stereochemistry, a torsion angle is defined as a particular example of a dihedral angle, describing the geometric relation of two parts of a molecule joined by a chemical bond.[5][6] Every set of three not-colinear atoms of a molecule defines a half-plane. As explained above, when two such half-planes intersect (i.e., a set of four consecutively-bonded atoms), the angle between them is a dihedral angle. Dihedral angles are used to specify the molecular conformation.[7] Stereochemical arrangements corresponding to angles between 0° and ±90° are called syn (s), those corresponding to angles between ±90° and 180° anti (a). Similarly, arrangements corresponding to angles between 30° and 150° or between −30° and −150° are called clinal (c) and those between 0° and ±30° or ±150° and 180° are called periplanar (p).
The two types of terms can be combined so as to define four ranges of angle; 0° to ±30° synperiplanar (sp); 30° to 90° and −30° to −90° synclinal (sc); 90° to 150° and −90° to −150° anticlinal (ac); ±150° to 180° antiperiplanar (ap). The synperiplanar conformation is also known as the syn- or cis-conformation; antiperiplanar as anti or trans; and synclinal as gauche or skew.
For example, with n-butane two planes can be specified in terms of the two central carbon atoms and either of the methyl carbon atoms. The syn-conformation shown above, with a dihedral angle of 60° is less stable than the anti-conformation with a dihedral angle of 180°.
For macromolecular usage the symbols T, C, G+, G−, A+ and A− are recommended (ap, sp, +sc, −sc, +ac and −ac respectively).
https://en.wikipedia.org/wiki/Dihedral_angle#In_stereochemistry
Saturday, September 18, 2021
09-18-2021-1248 - Rotation as possible energy source
Rotation as possible energy source [edit]
Because of the enormous amount of energy needed to launch a relativistic jet, some jets are possibly powered by spinning black holes. However, the frequency of high-energy astrophysical sources with jets suggest combinations of different mechanisms indirectly identified with the energy within the associated accretion disk and X-ray emissions from the generating source. Two early theories have been used to explain how energy can be transferred from a black hole into an astrophysical jet:
Blandford–Znajek process.[14] This theory explains the extraction of energy from magnetic fields around an accretion disk, which are dragged and twisted by the spin of the black hole. Relativistic material is then feasibly launched by the tightening of the field lines.
Penrose mechanism.[15] Here energy is extracted from a rotating black hole by frame dragging, which was later theoretically proven to be able to extract relativistic particle energy and momentum,[16] and subsequently shown to be a possible mechanism for jet formation.[17] This effect may also be explained in terms of gravitoelectromagnetism.
https://en.wikipedia.org/wiki/Astrophysical_jet#Relativistic_jet
Saturday, September 18, 2021
09-18-2021-0909 - In a single-sided version, the magnetic field can create repulsion forces that push the conductor away from the stator, levitating it and carrying it along the direction of the moving magnetic field.
The history of linear electric motors can be traced back at least as far as the 1840s to the work of Charles Wheatstone at King's College in London,[3] but Wheatstone's model was too inefficient to be practical. A feasible linear induction motor is described in US patent 782312 (1905; inventor Alfred Zehden of Frankfurt-am-Main), and is for driving trains or lifts. German engineer Hermann Kemper built a working model in 1935.[4] In the late 1940s, professor Eric Laithwaite of Imperial College in London developed the first full-size working model.
In a single-sided version, the magnetic field can create repulsion forces that push the conductor away from the stator, levitating it and carrying it along the direction of the moving magnetic field. Laithwaite called the later versions a magnetic river. These versions of the linear induction motor use a principle called transverse flux where two opposite poles are placed side by side. This permits very long poles to be used, and thus permits high speed and efficiency.[5]
https://en.wikipedia.org/wiki/Linear_induction_motor
Qubit in ion-trap quantum computing[edit]
The hyperfine states of a trapped ion are commonly used for storing qubits in ion-trap quantum computing. They have the advantage of having very long lifetimes, experimentally exceeding ~10 minutes (compared to ~1 s for metastable electronic levels).
The frequency associated with the states' energy separation is in the microwave region, making it possible to drive hyperfine transitions using microwave radiation. However, at present no emitter is available that can be focused to address a particular ion from a sequence. Instead, a pair of laser pulses can be used to drive the transition, by having their frequency difference (detuning) equal to the required transition's frequency. This is essentially a stimulated Raman transition. In addition, near-field gradients have been exploited to individually address two ions separated by approximately 4.3 micrometers directly with microwave radiation.[16]
See also[edit]
https://en.wikipedia.org/wiki/Hyperfine_structure
Saturday, September 18, 2021
Saturday, September 18, 2021
Sunday, September 19, 2021
https://en.wikipedia.org/wiki/Henry_Grey,_1st_Duke_of_Kent 1702
https://en.wikipedia.org/wiki/Henry_Cavendish 1731
https://en.wikipedia.org/wiki/Torbern_Bergman 1735
https://en.wikipedia.org/wiki/Antoine_Lavoisier 1743
https://en.wikipedia.org/wiki/Thomas_Charles_Hope 1766
https://en.wikipedia.org/wiki/Hydrogen_fuel
https://en.wikipedia.org/wiki/Pierre-Simon_Laplace - French 1749
https://en.wikipedia.org/wiki/Alessandro_Volta - Italy 1745
https://en.wikipedia.org/wiki/William_Herschel - German 1738
https://en.wikipedia.org/wiki/Isaac_Newton 1643
https://en.wikipedia.org/wiki/Pendulum
https://en.wikipedia.org/wiki/Harmonic_oscillator
https://en.wikipedia.org/wiki/Christiaan_Huygens 1629
https://en.wikipedia.org/wiki/Hooke%27s_law
https://en.wikipedia.org/wiki/Robert_Hooke 1635
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