Absorption loss

But metallic coatings have high absorption losses. But one can remedy them with dielectric coatings, which are necessary also to passivate the metal, avoiding oxidation. Aluminum is the best metal for the ultraviolet in addition it adheres on most substrates it needs passivation. Silver is easy to deposit it has the highest reflectance in the visible and the infrared since it tarnish rapidly, passivation is mandatory. Gold is the best material beyond 700 nm, and it is considered that it does not tarnish, which is not true actually because its surface is not that stable on the long term. 

The attenuation of an optical fibre results from physical phenomena either occurring within the fibre or coming from the environment. This is the sum of light lost by scattering in the fibre, absorption by the fibre materials, leakage of light out of the core due to environmental factors (e.g. microbends). Scattering and absorption losses dominate in every fibre. 

The third step (ANefj—>Ap) can be optimized by taking a large interaction length and a low wavelength, see (2), but there are trade offs with the desires of limited chip area and limited scattering and absorption losses respectively. 

The detection limit of the microresonator-based refractive index sensing device is directly related to the g-factor of the resonator and the sensitivity of the resonant mode discussed above. The g-factor of a microtube resonator is determined by the total loss of a resonant mode, including radiation loss, absorption loss, and surface roughness scattering loss. The overall g-factor can be expressed as... 

The disposition of insulin was shown to be susceptible to non-absorptive losses to metabolism and mucociliary clearance. Modification of the deposition profile of insulin in the lung showed that higher absorption rates were obtained for more peripheral deposition and co-administration of a metabolic inhibitor reduced losses to exopeptidase metabolism [101], It is acknowledged by the investigators that the IPL technique and the dosing technique of Byron and coworkers are not widely accessible and have therefore not been widely adopted [119], Active absorption has also been studied in this system as described in Sect. 6.2.43. 

Boriskina, S.V., Nosich, A.I., 1999, Radiation and absorption losses of the whispering-gallery-mode dielectric resonators excited by a dielectric waveguide, IEEE Trans. Microwave Theory Tech. 47 224-231. 

L.E. Busse, L. Goldberg, M.R. Surette, and G. Mizell, Absorption Losses in MgO-doped and undoped potassium niobate, JoMfno/ of Applied Physics 75(2), 1102-1110 (1994). 

Haug75 has reported that the concentration of TpC reaches a photostationary state at 280 nm and pH 7 at about half its initial value. Three photoproducts, separable by electrophoresis and stable to heat, are formed. The quantum yield for decay of TpC is independent of wavelength of light, and is 0.006 at pH 7 and 0.002 at pH 2. Heating the solution at 80°C restores about 40% of the absorption loss at 270 nm for the solution irradiated at pH 2 and about 70% of the loss for solutions irradiated at pH 7. Irradiation at 240 nm does not increase the absorption at 270 nm. One would expect dimers and hydrates to be formed in the photolysis, but the observations summarized here are difficult to reconcile with such products exclusively and suggest deep-seated irreversible changes. 

Loss of intensity Absorption Loss of intensity in region 1 in region 2 in region 3... 

Response times of undoped and Co-doped crystals for an incident intensity of 1 W/cm2 and a grating spacing of 0.7 pm are shown in Table 1. No systematic trend is apparent from these data, at least partially due to experimental uncertainties such as sample heating and variable reflection and absorption losses. Response times of as-grown and reduced Fe-, Mn-, and Cr-doped BaTi03 (18) range from 200 to 1200 ms under the same experimental conditions. Thus, it is clear that response times can vary considerably for crystals with different dopants and oxidation states. Additional experiments are needed to achieve better control over this key property. 

The sharp, relatively weak, absorption band in Yb(cp)3 causes a very low absorption loss even when the irradiating wavelength is less than 30nm from the absorption maxima. The broader absorption bands of the dithiolene cause larger linear absorption loss further from the absorption maxima. BDN, a similar Ni dithiolene, shows saturable absorption at 1064 nm (20), however this has not been observed in these materials. 

Modeling the early echoes using a sparse FIR filter results in an early response that can have an overly discrete sound quality, particularly with bright impulsive inputs. In practice it is necessary to associate some form of lowpass filtering with the early response to improve the sound quality. The simplest possible solution uses a single lowpass filter in series with the FIR filter [Gardner, 1992], where the filter response can be set empirically or by physical consideration of the absorptive losses. 

There are many possible reverberation algorithms that can be constructed by adding absorptive losses to allpass feedback loops, and these reverberators can sound very good. However, the design of these reverberators has to date been entirely empirical. There is no way to specify in advance a particular reverberation time function A(co), nor is there a deterministic method for choosing the filter parameters to eliminate tonal coloration. 

Reverberator formed by adding absorptive losses to an allpass feedback loop 115... 

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