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Blood: 0.2 Bone, cortical ... The primary causes of attenuation in matter are the ... Attenuation in a coaxial cable is a function of the materials and the ...
The dense MCA sign is caused by a fresh thrombus or embolus occluding the lumen of the middle cerebral artery. A thrombus with a high concentration of red blood cells and fibrin has increased density relative to normal flowing blood, leading to its hyperattenuating appearance on a non-contrast CT scan.
Sharp bends stress optic fibers and can cause losses. If a received signal is too strong a temporary fix is to wrap the cable around a pencil until the desired level of attenuation is achieved. [1] However, such arrangements are unreliable, since the stressed fiber tends to break over time.
The void fraction represents the ratio of the void volume within a thrombus, filled with a volume of blood (V blood) and the volume of thrombus material (V thrombus): = Void fraction can be estimated by measuring the attenuation increase (Δ) between NCCT and CTA in the thrombus (Δ thrombus) and in the contralateral artery, filling with ...
Attenuation over a cable run is significantly increased by the inclusion of connectors and splices. When computing the acceptable attenuation (loss budget) between a transmitter and a receiver one includes: dB loss due to the type and length of fiber optic cable, dB loss introduced by connectors, and; dB loss introduced by splices.
The optical power budget (also fiber-optic link budget and loss budget) in a fiber-optic communication link is the allocation of available optical power (launched into a given fiber by a given source) among various loss-producing mechanisms such as launch coupling loss, fiber attenuation, splice losses, and connector losses, in order to ensure that adequate signal strength (optical power) is ...
In the professional literature, the effect is often named Radiation Induced Attenuation (RIA), or Radiation-induced darkening. The loss of power or 'darkening' occurs because the chemical bonds forming the optical fiber core are disrupted by the impinging high energy resulting in the appearance of new electronic transition states giving rise to additional absorption in the wavelength regions ...
Furthermore, while G has virtually no effect at audio frequency, it can cause noticeable losses at high frequency with many of the dielectric materials used in cables due to a high loss tangent. Avoiding the losses caused by G is the reason many cables designed for use at UHF are air-insulated or foam-insulated (which makes them virtually air ...