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Frequency dependence of resonant sound transmission through glass with thickness h = 0.0052 m, with dimensions of 1.21×1.0.8 m
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The article deals with some acoustic properties of materials that have an impact on the sound insulation of building constructions, including sound absorption (abatement). These are namely, the capacity of materials to absorb, i.e. to reduce the sound energy passing through a building construction, the influence of an angle of sound wave incidence...
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Citations
... Tandon et al. (1998) observed that the sound pressure spectra of the sides of a kerosene engine driven portable generator set indicated high noise level mainly in the frequency range 265 to 555 Hz. The weight of the barrier, the frequency of the incident sound, the plate dimensions, its flexural rigidity, the loss factor and the angle of incidence of sound waves onto the plate determines sound insulation properties of real one-layered thin plates (Guzas et al. 2008). The best absorption capabilities can be found for the unconsolidated felt. ...
... Thus, the performance of an acoustic enclosure depends on the characteristics of the material construction and configuration. For a single-layered thin plate barriers, the noise insulation characteristics depend on its density, flexural modulus and dimensions, the sound wave incident angle to the plate and the loss factor (Gužas et al., 2008). As the barrier height increases or gets nearer to the source or the receiver, the efficiency of the noise attenuation capability also increases. ...
Environmental noise pollution from electric power generators has become seemingly intractable in most developing countries due to the epileptic power supply. Families as well as corporate organizations now rely on these standby generators for their daily electricity needs. The concern of this paper was the characterization of the developed vertical duct soundproof acoustic enclosure on mitigating the noise produced by portable mini generators. A total of six acoustic parallelepiped boxes were produced using chopped strand E-glass fiber mat reinforced composite panels with polyurethane foam inner lining. The generator noise spectra with and without the enclosure were obtained for comparative analysis. The sound pressure level of the generator noise at each enclosure height was also measured. It was found out that the noise level reduced by 12.8 dBA when the sound pressure levels at both conditions were taken and compared at optimal enclosure height (1600 mm). The result from exhaust ducting showed that exhaust duct projection, channeling out the fumes, did not significantly impact the enclosure insertion loss. The enclosure and the generator were also found to be in stable, acceptable thermal conditions while operating at rated load with a maximum temperature of 39 °C measured inside the enclosure. This eliminates the need for artificial cooling and its consequent power drain.
