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  1. en.wikipedia.org › wiki › BrickworkBrickwork - Wikipedia

    Brickwork is masonry produced by a bricklayer, using bricks and mortar. Typically, rows of bricks called courses[1][2] are laid on top of one another to build up a structure such as a brick wall. Bricks may be differentiated from blocks by size. For example, in the UK a brick is defined as a unit having dimensions less than 337.5 mm × 225 mm ...

  2. Vitrified tile. Vitrified tile is a ceramic tile with very low porosity. [1] It is an alternative to marble and granite flooring. Vitrified tiles are often used outdoors due to their water and frost resistance. There are four types of Vitrified tiles - Soluble salt, Double charge, Full Body, and Glazed.

    • Textual Basis
    • Interpretation of The Doctrine
    • Theory

    The primary textual basis for ISL in the U.S. Constitution derives from Article I, Section 4, Clause 1(The Elections Clause): Proponents of ISL derive additional textual support from the Presidential Electors Clause's mention of state legislatures in Article II, Section 1, Clause 2: The phrase, "the Legislature thereof" in both the Electors Clause ...

    No majority ruling of the U.S. Supreme Court has explicitly relied on ISL to determine the outcome of a case, and the Court has expressly rejected the doctrine at least once in Arizona State Legislature v. Arizona Independent Redistricting Commission (2015). ISL has been advanced or adopted at various points in American legal history at both the st...

    Justifications

    While all ISL proponents rely on the text and history of the Elections Clause and the Presidential Electors Clause, Professor Michael Morley has offered additional normative arguments in favor of ISL's grant of authority to state legislatures.Morley argues: 1. ISL allows state legislatures greater flexibility in responding to local needs and exigencies where state constitutions would otherwise "shackle legislatures' discretion." 2. The ultimate responsibility for regulating elections should b...

    Criticism

    ISL has come under criticism on originalist grounds for too narrowly interpreting the phrase "the Legislature thereof" in both the Elections Clause and the Presidential Electors Clause. American legal scholar Vikram Amar argues that ISL construes the concept of the state legislature as implausibly isolated from other state institutions, including state constitutions: "[T]he meaning of state 'legislature' was well accepted and bore a clear public understanding at the Founding: A state 'legisla...

    • Mechanism
    • Types
    • Two-Phase Stepper Motors
    • Higher-Phase Count Stepper Motors
    • Driver Circuits
    • Phase Current Waveforms
    • Theory
    • Ratings and Specifications
    • Applications
    • Stepper Motor System

    Brushed DC motors rotate continuously when DC voltageis applied to their terminals. The stepper motor is known for its property of converting a train of input pulses (typically square waves) into a precisely defined increment in the shaft’s rotational position. Each pulse rotates the shaft through a fixed angle. Stepper motors effectively have mult...

    There are three main types of stepper motors: 1. Permanent magnet 2. Variable reluctance stepper 3. Hybrid synchronous stepper Permanent magnet motors use a permanent magnet (PM) in the rotor and operate on the attraction or repulsion between the rotor PM and the statorelectromagnets. Pulses move the rotor in discrete steps, CW or CCW. If left powe...

    There are two basic winding arrangements for the electromagnetic coilsin a two phase stepper motor: bipolar and unipolar.

    Multi-phase stepper motors with many phases tend to have much lower levels of vibration. While they are more expensive, they do have a higher power density and with the appropriate drive electronics are often better suited to the application[citation needed].

    Stepper motor performance is strongly dependent on the driver circuit. Torque curvesmay be extended to greater speeds if the stator poles can be reversed more quickly, the limiting factor being a combination of the winding inductance. To overcome the inductance and switch the windings quickly, one must increase the drive voltage. This leads further...

    A stepper motor is a polyphase AC synchronous motor(see Theory below), and it is ideally driven by sinusoidal current. A full-step waveform is a gross approximation of a sinusoid, and is the reason why the motor exhibits so much vibration. Various drive techniques have been developed to better approximate a sinusoidal drive waveform: these are half...

    A step motor can be viewed as a synchronous AC motor with the number of poles (on both rotor and stator) increased, taking care that they have no common denominator. Additionally, soft magnetic material with many teeth on the rotor and stator cheaply multiplies the number of poles (reluctance motor). Modern steppers are of hybrid design, having bot...

    Stepper motors' nameplates typically give only the winding current and occasionally the voltage and winding resistance. The rated voltagewill produce the rated winding current at DC: but this is mostly a meaningless rating, as all modern drivers are current limiting and the drive voltages greatly exceed the motor rated voltage. Datasheets from the ...

    Computer controlled stepper motors are a type of motion-control positioning system. They are typically digitally controlled as part of an open loopsystem for use in holding or positioning applications. In the field of lasers and optics they are frequently used in precision positioning equipment such as linear actuators, linear stages, rotation stag...

    A stepper motor system consists of three basic elements, often combined with some type of user interface (host computer, PLC or dumb terminal): Indexers 1. The indexer (or controller) is a microprocessorcapable of generating step pulses and direction signals for the driver. In addition, the indexer is typically required to perform many other sophis...

    • History and Distinction from Ferrimagnetism
    • Ferromagnetic Materials
    • Explanation
    • See Also
    • External Links

    Historically, the term ferromagnetism was used for any material that could exhibit spontaneous magnetization: a net magnetic moment in the absence of an external magnetic field; that is any material that could become a magnet. This general definition is still in common use. However, in a landmark paper in 1948, Louis Néel showed that there are two ...

    Ferromagnetism is an unusual property that occurs in only a few substances. The common ones are the transition metals iron, nickel, cobalt and their alloys, and alloys of rare-earth metals. It is a property not just of the chemical make-up of a material, but of its crystalline structure and microstructure. Their ferromagnetism results from having m...

    The Bohr–Van Leeuwen theorem, discovered in the 1910s, showed that classical physics theories are unable to account for any form of magnetism, including ferromagnetism. Magnetism is now regarded as a purely quantum mechanical effect. Ferromagnetism arises due to two effects from quantum mechanics: spin and the Pauli exclusion principle.

    Media related to Ferromagnetismat Wikimedia Commons
    Sandeman, Karl (January 2008). "Ferromagnetic Materials". DoITPoMS. Dept. of Materials Sci. and Metallurgy, Univ. of Cambridge. Retrieved 2019-06-22.Detailed nonmathematical description of ferromag...
    Magnetism: Models and Mechanisms in E. Pavarini, E. Koch, and U. Schollwöck: Emergent Phenomena in Correlated Matter, Jülich 2013, ISBN 978-3-89336-884-6
  3. en.wikipedia.org › wiki › HysteresisHysteresis - Wikipedia

    Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable ...

  4. In electromagnetism, the magnetic moment is the magnetic strength and orientation of a magnet or other object that produces a magnetic field.Examples of objects that have magnetic moments include loops of electric current (such as electromagnets), permanent magnets, elementary particles (such as electrons), various molecules, and many astronomical objects (such as many planets, some moons ...