scholarly journals Measurement of Mathematical Constant &#960 and Physical Quantity <i>Pi</i>

2016 ◽  
Vol 04 (10) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milan Perkovac
Keyword(s):  
Physical Quantity ◽  
Mathematical Constant

Penalty Method Involving Electric Sliding Contact Problem

2014 ◽  
Vol 701-702 ◽  
pp. 246-249
Author(s):  
Sai Tan ◽  
Jun Yong Lu ◽  
Xin Lin Long ◽  
Xiao Zhang
Keyword(s):  
Finite Element ◽  
Contact Problem ◽  
Physical Quantity ◽  
Penalty Method ◽  
Sliding Contact ◽  
Interface Condition ◽  
Calculation Results ◽  
Coupled Equation ◽  
Finite Element Formulations ◽  
Methods Numerical

Basing on governing Maxwell and energy equation of rail gun considering armature movement in two dimension, The total domain to be solved is divided into two subdomains: moving (armature) part and static (rail) part, finite element formulations of two subdomains are built independently, then using the interface condition of two subdomains, formulations are connected by coupled equation which is derived out by penalty method. Shifted physical quantity is used to simulate movement. The final magnetic-thermal coupled fields finite element formulations of rail gun are established by these methods. Numerical calculation results compared by theoretical and other numerical results verify that penalty method is an effective way to deal with electric sliding contact problem associating with Shifted physical quantity method.

The International System of Units (SI)

1976 ◽  
Vol 46 (9) ◽  
pp. 623-628 ◽  
Author(s):  
George G. Stoner
Keyword(s):  
Physical Quantity ◽  
International System ◽  
Numerical Factor ◽  
International System Of Units ◽  
System Of Units ◽  
Physical Quantities

Le Système International d'Unités (officially designated SI in all languages) provides a logical, interconnected framework for measurements in commerce, industry, and science, including the textile and allied fields. SI is based on only nine elemental units. Seventeen important derived units have special names. Any number of derived units is possible to meet particular needs. SI has only one unit for each type of physical quantity. Prefixes cover a range of 1036 to form multiples and submultiples. SI has explicitly distinct units for mass (the kilogram) and force (the newton). Numerous older units of pressure, energy, and power are superseded by the pascal, the joule, and the watt, respectively. Each equation defining a derived unit contains only the number 1 as the numerical factor. SI has salient advantages because it is a system of units coherent with respect to the system of physical quantities and the equations relating them.

A ousadia do π ser racional

2020 ◽  
Author(s):  
Sidney Silva
Keyword(s):  
Rational Number ◽  
Pythagorean Theorem ◽  
Regular Polygons ◽  
The Real ◽  
Mathematical Question ◽  
Lower Limits ◽  
Mathematical Constant ◽  
Real Area

Pi (π) is used to represent the most known mathematical constant. By definition, π is the ratio of the circumference of a circle to its diameter. In other words, π is equal to the circumference divided by the diameter (π = c / d). Conversely, the circumference is equal to π times the diameter (c = π . d). No matter how big or small a circle is, pi will always be the same number. The first calculation of π was made by Archimedes of Syracuse (287-212 BC) who approached the area of a circle using the Pythagorean Theorem to find the areas of two regular polygons: the polygon inscribed within the circle and the polygon within which circle was circumscribed. Since the real area of the circle is between the areas of the inscribed and circumscribed polygons, the polygon areas gave the upper and lower limits to the area of the circle. Archimedes knew he had not found the exact value of π, but only an approximation within these limits. In this way, Archimedes showed that π is between 3 1/7 (223/71) and 3 10/71 (22/7). This research demonstrates that the value of π is 3.15 and can be represented by a fraction of integers, a/b, being therefore a Rational Number. It also demonstrates by means of an exercise that π = 3.15 is exact in 100% in the mathematical question.

scholarly journals The design of electric drives with electronic protection devices

2018 ◽  
Vol 226 ◽  
pp. 04012
Author(s):  
Boris D. Khastsaev ◽  
Larisa M. Dedegkaeva ◽  
Maksim P. Maslakov
Keyword(s):  
Physical Quantity ◽  
Linear Dependence ◽  
Electronic Device ◽  
Measuring Circuit ◽  
Structural Scheme ◽  
Electric Drives ◽  
Intelligent Sensors ◽  
Protection Devices ◽  
Physical Quantities ◽  
Improved Characteristics

The possibility of designing an electronic device for protection and diagnostics of electric drives with improved characteristics is considered. The technique and algorithm of design of similar devices, the structural scheme of the device constructed on their basis are offered. To improve the characteristics of the device of protection and diagnostics of electric drives in the work it is proposed to provide for the use of measuring transducers with linear dependencies of the output values on the controlled ones. The latter is possible as a result of the use of measuring circuits in measuring transducers with linearized dependencies of the output values on the input and the use of intelligent sensors. As a measuring circuit for the construction of measuring transducers is considered the measuring circuit of Kenigsberg, which is characterized by a linear dependence of the output active value of the passive measured (controlled physical quantities). At the same time, the intelligent sensors are additionally assigned the function of linearization of the output dependence of a «simple» sensor on the controlled physical quantity.

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