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Reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is ... more

The cross section is an effective area that quantifies the intrinsic likelihood of a scattering event when an incident beam strikes a target object, made ... more

In physics, attenuation (in some contexts also called extinction) is the gradual loss in intensity of any kind of flux through a medium. For instance, dark ... more

Stokes’s law of sound attenuation is a formula for the attenuation of sound in a Newtonian fluid, such as water or air, due to the fluid’s ... more

In reflection seismology, the anelastic attenuation factor, often expressed as seismic quality factor or Q (which is inversely proportional to attenuation ... more

Damping is an influence within or upon an oscillatory system that has the effect of reducing, restricting or preventing its oscillations.( The neper ... more

When an electromagnetic wave travels through a medium in which it gets attenuated (this is called an “opaque” or “attenuating” ... more

In radiometry, radiant exitance is the radiant flux emitted by a surface per unit area, and spectral exitance is the radiant exitance of a surface per unit ... more

When an electromagnetic wave travels through a medium in which it gets attenuated (this is called an “opaque” or “attenuating” ... more

In physics, optical depth or optical thickness, is the natural logarithm of the ratio of incident to transmitted radiant power through a material, and ... more

A low-pass filter is a filter that passes signals with a frequency lower than a certain cutoff frequency and attenuates signals with frequencies higher ... more

The cross section is an effective area that quantifies the intrinsic likelihood of a scattering event when an incident beam strikes a target object, made ... more

The cross section is an effective area that quantifies the intrinsic likelihood of a scattering event when an incident beam strikes a target object, made ... more

In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film, as ... more

Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the ... more

Heat flux or thermal flux is the rate of heat energy transfer through a given surface, per unit surface. The heat transfer coefficient or film coefficient, ... more

is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars. It is defined in ... more

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In engineering, the damping ratio is a dimensionless measure describing how ... more

In fluid mechanics, the Rayleigh number (Ra) for a fluid is a dimensionless number associated with buoyancy-driven flow, also known as free convection or ... more

In chemistry, a closely related quantity called “absorbance” or “decadic absorbance” is used instead of optical depth: the common ... more

Timoshenko beam model takes into account shear deformation and rotational inertia effects, making it suitable for describing the behavior of short sandwich ... more

Timoshenko beam model takes into account shear deformation and rotational inertia effects, making it suitable for describing the behavior of short sandwich ... more

The resistance to the flow of heat by the material of pipe wall can be expressed as a “heat transfer coefficient of the pipe wall”. However, ... more

A link budget is accounting of all of the gains and losses from the transmitter, through the medium (free space, cable, waveguide, fiber, etc.) to the ... more

There exist simple fluid-specific correlations for heat transfer coefficient in boiling. The Thom correlation is for the flow of boiling water (subcooled ... more

Forward osmosis (FO) is an osmotic process that, like reverse osmosis (RO), uses a semi-permeable membrane to effect separation of water from dissolved ... more

For many applications involving terrestrial albedo, the albedo at a particular solar zenith angle θi can reasonably be approximated by the formula ... more

Diffusivity or diffusion coefficient is a proportionality constant between the molar flux due to molecular diffusion and the gradient in the concentration ... more

Auger electron spectroscopy is a common analytical technique used specifically in the study of surfaces and, more generally, in the area of materials ... more

A bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand ... more