Cargando…

Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk

The current study deals with the analysis of sound absorption characteristics of foxtail millet husk powder. Noise is one the most persistent pollutants which has to be dealt seriously. Foxtail millet is a small seeded cereal cultivated across the world and its husk is less explored for its utilizat...

Descripción completa

Detalles Bibliográficos
Autores principales: Balasubramanian, Dhayalini, Rajendran, Senthil, Srinivasan, Bhuvanesh, Angamuthu, Nirmalakumari
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696682/
https://www.ncbi.nlm.nih.gov/pubmed/33202920
http://dx.doi.org/10.3390/ma13225126
_version_ 1783615459555278848
author Balasubramanian, Dhayalini
Rajendran, Senthil
Srinivasan, Bhuvanesh
Angamuthu, Nirmalakumari
author_facet Balasubramanian, Dhayalini
Rajendran, Senthil
Srinivasan, Bhuvanesh
Angamuthu, Nirmalakumari
author_sort Balasubramanian, Dhayalini
collection PubMed
description The current study deals with the analysis of sound absorption characteristics of foxtail millet husk powder. Noise is one the most persistent pollutants which has to be dealt seriously. Foxtail millet is a small seeded cereal cultivated across the world and its husk is less explored for its utilization in polymer composites. The husk is the outer protective covering of the seed, rich in silica and lingo-cellulose content making it suitable for sound insulation. The acoustic characterization is done for treated foxtail millet husk powder and polypropylene composite panels. The physical parameters like fiber mass content, density, and thickness of the composite panel were varied and their influence over sound absorption was mapped. The influence of porosity, airflow resistance, and tortuosity was also studied. The experimental result shows that 30-mm thick foxtail millet husk powder composite panel with 40% fiber mass content, 320 kg/m(3) density showed promising sound absorption for sound frequency range above 1000 Hz. We achieved noise reduction coefficient (NRC) value of 0.54. In view to improve the performance of the panel in low-frequency range, we studied the efficiency of incorporating air gap and rigid backing material to the designed panel. We used foxtail millet husk powder panel of density 850 kg/m(3) as rigid backing material with varying air gap thickness. Thus the composite of 320 kg/m(3) density, 30-mm thick when provided with 35-mm air gap and backing material improved the composite’s performance in sound frequency range 250 Hz to 1000 Hz. The overall sound absorption performance was improved and the NRC value and average sound absorption coefficient (SAC) were increased to 0.7 and 0.63 respectively comparable with the commercial acoustic panels made out of the synthetic fibers. We have calculated the sound absorption coefficient values using Delany and Bezlay model (D&B model) and Johnson–Champoux–Allard model (JCA model) and compared them with the measured sound absorption values.
format Online
Article
Text
id pubmed-7696682
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-76966822020-11-29 Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk Balasubramanian, Dhayalini Rajendran, Senthil Srinivasan, Bhuvanesh Angamuthu, Nirmalakumari Materials (Basel) Article The current study deals with the analysis of sound absorption characteristics of foxtail millet husk powder. Noise is one the most persistent pollutants which has to be dealt seriously. Foxtail millet is a small seeded cereal cultivated across the world and its husk is less explored for its utilization in polymer composites. The husk is the outer protective covering of the seed, rich in silica and lingo-cellulose content making it suitable for sound insulation. The acoustic characterization is done for treated foxtail millet husk powder and polypropylene composite panels. The physical parameters like fiber mass content, density, and thickness of the composite panel were varied and their influence over sound absorption was mapped. The influence of porosity, airflow resistance, and tortuosity was also studied. The experimental result shows that 30-mm thick foxtail millet husk powder composite panel with 40% fiber mass content, 320 kg/m(3) density showed promising sound absorption for sound frequency range above 1000 Hz. We achieved noise reduction coefficient (NRC) value of 0.54. In view to improve the performance of the panel in low-frequency range, we studied the efficiency of incorporating air gap and rigid backing material to the designed panel. We used foxtail millet husk powder panel of density 850 kg/m(3) as rigid backing material with varying air gap thickness. Thus the composite of 320 kg/m(3) density, 30-mm thick when provided with 35-mm air gap and backing material improved the composite’s performance in sound frequency range 250 Hz to 1000 Hz. The overall sound absorption performance was improved and the NRC value and average sound absorption coefficient (SAC) were increased to 0.7 and 0.63 respectively comparable with the commercial acoustic panels made out of the synthetic fibers. We have calculated the sound absorption coefficient values using Delany and Bezlay model (D&B model) and Johnson–Champoux–Allard model (JCA model) and compared them with the measured sound absorption values. MDPI 2020-11-13 /pmc/articles/PMC7696682/ /pubmed/33202920 http://dx.doi.org/10.3390/ma13225126 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Balasubramanian, Dhayalini
Rajendran, Senthil
Srinivasan, Bhuvanesh
Angamuthu, Nirmalakumari
Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title_full Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title_fullStr Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title_full_unstemmed Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title_short Elucidating the Sound Absorption Characteristics of Foxtail Millet (Setariaitalica) Husk
title_sort elucidating the sound absorption characteristics of foxtail millet (setariaitalica) husk
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696682/
https://www.ncbi.nlm.nih.gov/pubmed/33202920
http://dx.doi.org/10.3390/ma13225126
work_keys_str_mv AT balasubramaniandhayalini elucidatingthesoundabsorptioncharacteristicsoffoxtailmilletsetariaitalicahusk
AT rajendransenthil elucidatingthesoundabsorptioncharacteristicsoffoxtailmilletsetariaitalicahusk
AT srinivasanbhuvanesh elucidatingthesoundabsorptioncharacteristicsoffoxtailmilletsetariaitalicahusk
AT angamuthunirmalakumari elucidatingthesoundabsorptioncharacteristicsoffoxtailmilletsetariaitalicahusk