Recent Advances in the Sound Insulation Properties of Bio-based Materials

Recent Advances in the Sound Insulation Properties of Bio-based Materials

Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulatio...

the effect of authentic listening materials on the listening proficiency of efl learners in the intermediate level

having conducted the experiment and analysed the data, the researcher computed the groups mean scores and variances for the test relating to the research question. as the final atep, a t-test was conodonted for the hypothesis. as noted earlier, the significance level was determined at .05 and .01 respectively. the observed t-value was higher than the critical t-value at. 5 and .01 levels. conse...

Using the eigenvalues of the sound equation to determine the properties of materials

In this article, the eigenvalues of the sound equation are used to determine the refractive index. This refractive index helps to extract the acoustic components of the material such as the speed of sound in the material. This will help in identifying targets, especially in the field of signal processing. For this purpose, a method has been extracted that can be used to establish a relation bet...

Recent advances in bio-based polymers and composites

a synchronic and diachronic approach to the change route of address terms in the two recent centuries of persian language

terms of address as an important linguistics items provide valuable information about the interlocutors, their relationship and their circumstances. this study was done to investigate the change route of persian address terms in the two recent centuries including three historical periods of qajar, pahlavi and after the islamic revolution. data were extracted from a corpus consisting 24 novels w...