The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste

In the past few decades, synthetic fibers are been used widely in the field of sound absorption due to their superior characteristics such as durable and chemical resistant. However, there are several disadvantages of synthetic fibers such as non-biodegradability and hazards to the health of human....

Full description

Saved in:

Bibliographic Details
Main Author:	Ahmad Nordin, Mohd Nor Azmi
Format:	Thesis
Language:	English English English
Published:	2019
Subjects:	TH1000-1725 Systems of building construction Including fireproof construction, concrete construction
Online Access:	http://eprints.uthm.edu.my/391/1/24p%20MOHD%20NOR%20AZMI%20AHMAD%20NORDIN.pdf http://eprints.uthm.edu.my/391/2/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/391/3/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20WATERMARK.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-uthm-ep.391
record_format	uketd_dc
spelling	my-uthm-ep.3912021-07-25T01:58:47Z The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste 2019-02 Ahmad Nordin, Mohd Nor Azmi TH1000-1725 Systems of building construction. Including fireproof construction, concrete construction In the past few decades, synthetic fibers are been used widely in the field of sound absorption due to their superior characteristics such as durable and chemical resistant. However, there are several disadvantages of synthetic fibers such as non-biodegradability and hazards to the health of human. In this research, the natural sound absorber from cogon grass was investigated. The objective of the research was to evaluate the performance of cogon grass physical characteristics on its acoustical behavior, to evaluate the effect of sodium hydroxide (NaOH) treatment times on physical and acoustical characteristics of cogon grass, to investigate the decay effects after it was left over for twelve months and lastly to compare and verify the acoustical results with theoretical models based on (Delany-Bazley and Miki Model). The measurement of acoustical characteristics which are sound absorption coefficient (SAC) and noise reduction coefficient (NRC) were done by using impedance tube method (ITM). The samples of cogon grass were tested in a way of the untreated and treated with NaOH in varied soaked hours which are one, two, three, four and five hours. Scanning electron microscope (SEM) and density kit were used to investigate physical characteristics. The research confirmed that physical characteristics of tortuosity and airflow resistivity values tend to increase with the increment of treatment times, but the density and porosity tend to decrease. Untreated samples were tested with varied thicknesses of 10, 20, 30, 40 and 50mm. The results show SAC value increases when the thickness of the sample was increased. Treated samples results show the least treated sample (1 hour) reached the maximum SAC value and indicated the highest value of NRC which is 0.50. The results also show a reduction in sound absorption value after the samples were left for twelve months. Verification parts demonstrated that Delany-Bazley and Miki Model can predict approximately pattern compared with ITM results because of the theoretical models are developed by a simple empirical model approach. Overall, cogon grass samples have the good characteristics to be an acoustic material component. 2019-02 Thesis http://eprints.uthm.edu.my/391/ http://eprints.uthm.edu.my/391/1/24p%20MOHD%20NOR%20AZMI%20AHMAD%20NORDIN.pdf text en public http://eprints.uthm.edu.my/391/2/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/391/3/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Mekanikal dan Pembuatan
institution	Universiti Tun Hussein Onn Malaysia
collection	UTHM Institutional Repository
language	English English English
topic	TH1000-1725 Systems of building construction Including fireproof construction, concrete construction
spellingShingle	TH1000-1725 Systems of building construction Including fireproof construction, concrete construction Ahmad Nordin, Mohd Nor Azmi The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
description	In the past few decades, synthetic fibers are been used widely in the field of sound absorption due to their superior characteristics such as durable and chemical resistant. However, there are several disadvantages of synthetic fibers such as non-biodegradability and hazards to the health of human. In this research, the natural sound absorber from cogon grass was investigated. The objective of the research was to evaluate the performance of cogon grass physical characteristics on its acoustical behavior, to evaluate the effect of sodium hydroxide (NaOH) treatment times on physical and acoustical characteristics of cogon grass, to investigate the decay effects after it was left over for twelve months and lastly to compare and verify the acoustical results with theoretical models based on (Delany-Bazley and Miki Model). The measurement of acoustical characteristics which are sound absorption coefficient (SAC) and noise reduction coefficient (NRC) were done by using impedance tube method (ITM). The samples of cogon grass were tested in a way of the untreated and treated with NaOH in varied soaked hours which are one, two, three, four and five hours. Scanning electron microscope (SEM) and density kit were used to investigate physical characteristics. The research confirmed that physical characteristics of tortuosity and airflow resistivity values tend to increase with the increment of treatment times, but the density and porosity tend to decrease. Untreated samples were tested with varied thicknesses of 10, 20, 30, 40 and 50mm. The results show SAC value increases when the thickness of the sample was increased. Treated samples results show the least treated sample (1 hour) reached the maximum SAC value and indicated the highest value of NRC which is 0.50. The results also show a reduction in sound absorption value after the samples were left for twelve months. Verification parts demonstrated that Delany-Bazley and Miki Model can predict approximately pattern compared with ITM results because of the theoretical models are developed by a simple empirical model approach. Overall, cogon grass samples have the good characteristics to be an acoustic material component.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Ahmad Nordin, Mohd Nor Azmi
author_facet	Ahmad Nordin, Mohd Nor Azmi
author_sort	Ahmad Nordin, Mohd Nor Azmi
title	The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
title_short	The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
title_full	The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
title_fullStr	The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
title_full_unstemmed	The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
title_sort	evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste
granting_institution	Universiti Tun Hussein Onn Malaysia
granting_department	Fakulti Kejuruteraan Mekanikal dan Pembuatan
publishDate	2019
url	http://eprints.uthm.edu.my/391/1/24p%20MOHD%20NOR%20AZMI%20AHMAD%20NORDIN.pdf http://eprints.uthm.edu.my/391/2/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/391/3/MOHD%20NOR%20AZMI%20AHMAD%20NORDIN%20WATERMARK.pdf
_version_	1747830599145488384

The evaluation of acoustic characteristic performance on natural sound absorbing materials from cogon grass waste

Similar Items