coefficient of roughness
21Dimensionless quantity — In dimensional analysis, a dimensionless quantity or quantity of dimension one is a quantity without an associated physical dimension. It is thus a pure number, and as such always has a dimension of 1.[1] Dimensionless quantities are widely used… …
22Clutter (radar) — Clutter is a term used for unwanted echoes in electronic systems, particularly in reference to radars. Such echoes are typically returned from ground, sea, rain, animals/insects, chaff and atmospheric turbulences, and can cause serious… …
23Traction (engineering) — Traction refers to the friction between a drive member and the surface it moves upon, where the friction is used to provide motion.For the purposes of driving a wheeled vehicle, high friction is generally desired, as it provides a more positive… …
24Hazen-Williams equation — The Hazen Williams formula can be used to calculate the pressure loss per one foot of pipe of a known diameter due to friction dependent on the flow. This equation is commonly used for pressure drop calculations in fire sprinkler systems, water… …
25Abeles matrix formalism — The Abeles matrix method is a computationally fast and easy way to calculate the specular reflectivity from a stratified interface, as a function of the perpendicular momentum transfer, Qz .Application Q z=frac{4pi}{lambda}sin heta=2k z Where θ… …
26Morison equation — Flow forces according to the Morison equation for a body placed in a harmonic flow, as a function of time. Blue line: drag force; red line: inertia force; black line: total force according to the Morison equation. Note that the inertia force is… …
27Wind profile power law — The wind profile power law is a relationship between the wind speeds at one height, and those at another. The power law is often used in wind power assessments [Elliott, D.L., C.G. Holladay, W.R. Barchet, H.P. Foote, and W.F. Sandusky, 1986,… …
28Speed of sound — Sound is a vibration that travels through an elastic medium as a wave. The speed of sound describes how much distance such a wave travels in a certain amount of time. In SI Units with dry air at 20 °C (68 °F), the speed of sound is 343 m/s. This… …
29Quartz crystal microbalance — A quartz crystal microbalance (QCM) measures a mass per unit area by measuring the change in frequency of a quartz crystal resonator. The resonance is disturbed by the addition or removal of a small mass due to oxide growth/decay or film… …
30Color histogram — Not to be confused with Image histogram. In image processing and photography, a color histogram is a representation of the distribution of colors in an image. For digital images, a color histogram represents the number of pixels that have colors… …
