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Journal : Jurnal Natural

The Effect of Ge Content on the Optical and Electrical Properties of A-Sige: H Thin Films Mursal Mursal; Irhamni Irhamni; T Winata
Jurnal Natural Volume 14, Number 1, March 2014
Publisher : Universitas Syiah Kuala

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Abstract

The effect of Ge content on the optical and electrical properties of a-SiGe:H thin films deposited by HWC-PECVD had been investigated. The a-SiGe:H films ware grown on corning glass 7059 substrate using 10% diluted mixture of GeH4 and SiH4 gases, respectively. The GeH4 gas flow rate was varied from 2.5 – 12.5 sccm, while the flow rate of SiH4 was kept constant at 70 sccm. The results showed that the deposition rate of a-SiGe:H thin films increased by  increasing of GeH4 gas flow rate. In addition, the Ge content in the film increased and  the optical band gap decreased. The dark conductivity of a-SiGe:H films were relatively constant, whereas the photo conductivity decreased with increasing of Ge content.
DESAIN OF ACOUSTIC SANDWICH COMPOSITE FROM FOAM CONCRETE AND PALM FIBER Devya Kartika Devya; Mursal Mursal; Zulkarnain Djalil
Jurnal Natural Volume 18, Number 2, June 2018
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (601.399 KB) | DOI: 10.24815/jn.v18i2.9706

Abstract

The purpose of this research were to investigate the influence of palm fiber composition and the number of hole cavities was varied with design Acoustic Sandwich Composite on sound absorption of acoustic panel. Acoustic panel were made of palm fiber as core and foam concreate as skin upper layer and bottom layer where there is a hole cavity on skin upper layer. Composition and the number of hole cavities was varied from 1 to 3 kg and the number of hole cavities from 25 to 81 hole. Sound absorption measurement was conducted by using reverberation room method based on ISO-354 (2003) with pink and white noise as sound source.The results showed that sample thickness affect acoustic absorption value effectively shifted at low frequencies, as in this research the best sound absorption occurs in panel with composition palm fiber most widely 3 kg, but coeffesient absorpsi value effective is in the range 250 Hz and use the number of hole cavities at skin upper layer of each sample effectively cause sound absorption coeffisient value increased, for both pink and white noise from sound source.Keyword : acoustic panel, foam concrete, palm fiber, sandwich composite, and absorption coefficient
DESAIN OF ACOUSTIC SANDWICH COMPOSITE FROM FOAM CONCRETE AND PALM FIBER Devya Kartika Devya; Mursal Mursal; Zulkarnain Djalil
Jurnal Natural Volume 18, Number 2, June 2018
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v18i2.9706

Abstract

The purpose of this research were to investigate the influence of palm fiber composition and the number of hole cavities was varied with design Acoustic Sandwich Composite on sound absorption of acoustic panel. Acoustic panel were made of palm fiber as core and foam concreate as skin upper layer and bottom layer where there is a hole cavity on skin upper layer. Composition and the number of hole cavities was varied from 1 to 3 kg and the number of hole cavities from 25 to 81 hole. Sound absorption measurement was conducted by using reverberation room method based on ISO-354 (2003) with pink and white noise as sound source.The results showed that sample thickness affect acoustic absorption value effectively shifted at low frequencies, as in this research the best sound absorption occurs in panel with composition palm fiber most widely 3 kg, but coeffesient absorpsi value effective is in the range 250 Hz and use the number of hole cavities at skin upper layer of each sample effectively cause sound absorption coeffisient value increased, for both pink and white noise from sound source.Keyword : acoustic panel, foam concrete, palm fiber, sandwich composite, and absorption coefficient