Search results
Results From The WOW.Com Content Network
Fresnel zone: D is the distance between the transmitter and the receiver; r is the radius of the first Fresnel zone (n=1) at point P. P is d1 away from the transmitter, and d2 away from the receiver. The concept of Fresnel zone clearance may be used to analyze interference by obstacles near the path of a radio beam.
In fluid dynamics, Sauter mean diameter (SMD) is an average measure of particle size.It was originally developed by German scientist Josef Sauter in the late 1920s. [1] [2] It is defined as the diameter of a sphere that has the same volume/surface area ratio as a particle of interest.
The area of a circle of radius R is . Given the area of a non-circular object A, one can calculate its area-equivalent radius by setting = or, alternatively: = Often the area considered is that of a cross section.
For plates with many zones, you can calculate the distance to the focus if you only know the radius of the outermost zone, r N, and its width, Δr N: = In the long focal length limit, the area of each zone is equal, because the width of the zones must decrease farther from the center.
The mobility of non-spherical aerosol particles can be described by the hydrodynamic radius. In the continuum limit, where the mean free path of the particle is negligible compared to a characteristic length scale of the particle, the hydrodynamic radius is defined as the radius that gives the same magnitude of the frictional force, as that of a sphere with that radius, i.e.
The solid angle of an object that is very far away is roughly proportional to the ratio of area to squared distance. Here "area" means the area of the object when projected along the viewing direction. Any area on a sphere which is equal in area to the square of its radius, when observed from its center, subtends precisely one steradian.
The surface of the spherical segment (excluding the bases) is called spherical zone. Geometric parameters for spherical segment. If the radius of the sphere is called R , the radii of the spherical segment bases are a and b , and the height of the segment (the distance from one parallel plane to the other) called h , then the volume of the ...
The Wigner–Seitz radius, named after Eugene Wigner and Frederick Seitz, is the radius of a sphere whose volume is equal to the mean volume per atom in a solid (for first group metals). [1] In the more general case of metals having more valence electrons, r s {\displaystyle r_{\rm {s}}} is the radius of a sphere whose volume is equal to the ...