Nonlinear propagation of incoherent photons in a radiation background

Abstract Source/filter models have frequently been used to model sound production of the vocal apparatus and musical instruments. Beginning in 1968, in an effort to measure the transfer function (i.e., transmission response or filter characteristic) of a trombone while being played by expert musicians, sound pressure signals from the mouthpiece and the trombone bell output were recorded in an anechoic room and then subjected to harmonic spectrum analysis. Output/input ratios of the signals’ harmonic amplitudes plotted vs. harmonic frequency then became points on the trombone’s transfer function. The first such recordings were made on analog 1/4 inch stereo magnetic tape. In 2000 digital recordings of trombone mouthpiece and anechoic output signals were made that provide a more accurate measurement of the trombone filter characteristic. Results show that the filter is a high-pass type with a cutoff frequency around 1000 Hz. Whereas the characteristic below cutoff is quite stable, above cutoff it is extremely variable, depending on level. In addition, measurements made using a swept-sine-wave system in 1972 verified the high-pass behavior, but they also showed a series of resonances whose minima correspond to the harmonic frequencies which occur under performance conditions. For frequencies below cutoff the two types of measurements corresponded well, but above cutoff there was a considerable difference. The general effect is that output harmonics above cutoff are greater than would be expected from linear filter theory, and this effect becomes stronger as input pressure increases. In the 1990s and early 2000s this nonlinear effect was verified by theory and measurements which showed that nonlinear propagation takes place in the trombone, causing a wave steepening effect at high amplitudes, thus increasing the relative strengths of the upper harmonics.

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Features of sanitary and hygienic characteristics of silvinite complexes

Sanitarnyj vrač (Sanitary Inspector) ◽

10.33920/med-08-2003-06 ◽

2020 ◽

pp. 57-62

Author(s):

E. Ryazanova ◽

V. Barannikov ◽

V. Khokhryakova ◽

L. Kirichenko ◽

S. Selivanova

Keyword(s):

Video Camera ◽

Treatment Center ◽

Internal Environment ◽

Radiation Background ◽

Medical Environment ◽

Light Levels ◽

Salt Complex ◽

Radio Equipment ◽

Environment Noise ◽

Medical University

Currently, medical technologies based on natural factors are widely used in practical health care, including the effect of the medicinal properties of the mineral silvinite (natural potassium salts of the Verkhnekamsk Deposit) on the patient’s body. However, there is no regulatory framework for sanitary control of such devices. The aim of the study was to develop methodological approaches to the hygienic assessment of silvinite complexes. The analysis of the current regulations used in carrying out hygienic supervision and preventive measures in the salt structures that are part of the silvinite complexes is carried out. Based on long-term hygienic studies of silvinite structures by the salt treatment Center of Perm medical University. academician E. A. Wagner together with LLC NPK «Medical climate» (Tchaikovsky) developed and implemented sanitary and hygienic requirements for the created salt complexes. It is a complex of structural divisions, including the place of stay and treatment of patients, as well as the salt device. All units must meet the requirements of current sanitary rules and regulations. It is necessary to conduct a thorough survey of the location of the future salt complex. Optimal conditions of the internal environment in silvinite structures are determined by a special air preparation system consisting of air conditioning and cleaning of the external air using a filter-saturator. The special hygienic requirements of the sylvinite furniture in the room, the decoration of walls, ceilings and floors. The room must be equipped with radio equipment and a video camera for monitoring patients. Full expanded hygienic control of the parameters of the medical environment of silvinite premises should be carried out at least once a year according to the following indicators: microclimate parameters, content of multicomponent fine salt aerosol, aeroionic composition of the air environment, radiation background, microbial contamination of the internal environment, noise and light levels. Thus, increasing the use of salt therapy requires further research to improve the sanitary and hygienic control of silvinite complexes.

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Nonlinear Propagation of Laser Light of Different Polarizations

Advances in Chemical Physics ◽

10.1002/9780470141434.ch6 ◽

2007 ◽

pp. 217-247

Author(s):

Genevieve Rivoire

Keyword(s):

Laser Light ◽

Nonlinear Propagation

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Second‐harmonic diffraction field in nonlinear propagation of transversely limited surface acoustic wave beams

Journal of Applied Physics ◽

10.1063/1.330486 ◽

1982 ◽

Vol 53 (12) ◽

pp. 8516-8524 ◽

Cited By ~ 4

Author(s):

A. Alippi ◽

A. Palma ◽

A. Palmieri ◽

G. Socino ◽

E. Verona

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Second Harmonic ◽

Nonlinear Propagation ◽

Diffraction Field ◽

Limited Surface

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The nonlinear effects on the characteristics of gravity wave packets: dispersion and polarization relations

Annales Geophysicae ◽

10.1007/s00585-000-1316-z ◽

2000 ◽

Vol 18 (10) ◽

pp. 1316-1324 ◽

Cited By ~ 13

Author(s):

S.-D. Zhang ◽

F. Yi ◽

J.-F. Wang

Keyword(s):

Gravity Wave ◽

Gravity Waves ◽

Middle Atmosphere ◽

Wave Packets ◽

Nonlinear Effects ◽

Wave Theory ◽

Nonlinear Propagation ◽

Waves And Tides ◽

Time Variations ◽

Isothermal Atmosphere

Abstract. By analyzing the results of the numerical simulations of nonlinear propagation of three Gaussian gravity-wave packets in isothermal atmosphere individually, the nonlinear effects on the characteristics of gravity waves are studied quantitatively. The analyses show that during the nonlinear propagation of gravity wave packets the mean flows are accelerated and the vertical wavelengths show clear reduction due to nonlinearity. On the other hand, though nonlinear effects exist, the time variations of the frequencies of gravity wave packets are close to those derived from the dispersion relation and the amplitude and phase relations of wave-associated disturbance components are consistent with the predictions of the polarization relation of gravity waves. This indicates that the dispersion and polarization relations based on the linear gravity wave theory can be applied extensively in the nonlinear region.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

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