scholarly journals Performance Characteristics of Unsaturated Polyester Reinforced with High Frequency Microwave Treated Natural Fibre

2021 ◽  
Vol 1107 (1) ◽  
pp. 012029
Author(s):  
Patrick Ehi Imoisili ◽  
Tien-Chien Jen
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jiangnan Xiao ◽  
Chuang Zhao ◽  
Xingxing Feng ◽  
Xu Dong ◽  
Jiangli Zuo ◽  
...  

With the development trend of wireless and broadband in the communication link and even the whole information industry, the demand of high-frequency microwave bandwidth has been increasing. The RoF network system solves the problem of spectrum congestion in low-frequency band by providing an effective technology for the distribution of high-frequency microwave signals over optical fiber links. However, the traditional mm-wave generation technique is limited by the bandwidth of electronic devices. It is difficult to generate high-frequency and low-phase noise mm-wave signals with pure electrical components. The mm-wave communication technology based on photon assisted can overcome the bandwidth bottleneck of electronic devices and provide the potential for developing the low-cost infrastructure demand of broadband mobile services. This paper will briefly explain the characteristics of the RoF network system and the advantages of high-frequency mm-wave. Then we, respectively, introduce the modulation schemes of RoF mm-wave generation based on photon assisted including directly modulated laser (DML), external modulation, and optical heterodyne. The review mainly focuses on a variety of different mm-wave generation technologies including multifrequency vector mm-wave. Furthermore, we list several approaches to realize the large capacity data transmission techniques and describe the digital signal processing (DSP) algorithm flow in the receiver. In the end, we summarize the RoF network system and look forward to the future.


Author(s):  
Agung Efriyo Hadi ◽  
Tezara Cionita ◽  
Deni Fajar Fitriyana ◽  
Januar Parlaungan Siregar ◽  
Ahmed Nurye Oumer ◽  
...  

Incorporating natural fibre as reinforcement in the polymer matrix has shown a negative effect since the natural fibre is hydrophilic. The natural fibre easily absorbs water which causes an effect on the mechanical properties of the composites. The objective of this paper is to investigate the water absorption behaviour of hybrid jute-roselle woven fibre reinforced unsaturated polyester composite and the effect of water absorption in terms of tensile strength and tensile modulus. The effect of hybrid composite on the thickness swelling will be tested. The fabrication method used in this study is the hand lay-up technique to fabricate 2-layer and 3-layer composites with layering sequences of woven jute (J)/roselle (Ro) fibre. The results of the study showed that pure roselle fibres for 2 and 3-layer composites have the highest water absorption behaviour 3.86% and 5.51%, respectively, in 28 days) as well as thickness swelling effect, whereas hybrid J-Ro and J-J-Ro composites showed the least water absorption (2.65% and 3.76%, respectively) in 28 days) in both the tests. The hybridisation between jute and roselle fibres reduced water absorption behaviour and improved the fibres dimensional stability. The entire composites showed a decreasing trend for both tensile strength and tensile modulus strength after five weeks of water immersion. Jute fibre composite hybridised with roselle fibre can be used to reduce the total reduction of both tensile strength and tensile modulus throughout the whole immersion period. Moreover, the tensile testing showed that jute fibre composite hybridised with roselle fibre have produced the strongest composite with the highest tensile and modulus strength compared to other types of composites. The hybridisation of diverse fibre reinforcements aids in minimising the composite water absorption and thickness swelling, hence reducing the effect of tensile characteristics.


2014 ◽  
Vol 695 ◽  
pp. 159-162 ◽  
Author(s):  
Januar Parlaungan Siregar ◽  
Tezara Cionita ◽  
Dandi Bachtiar ◽  
Mohd Ruzaimi Mat Rejab

In recent years natural fibres such as sisal, jute, kenaf, pineapple leaf and banana fibres appear to be the outstanding materials which come as the viable and abundant substitute for the expensive and non-renewable synthethic fibre. This paper investigate the effect of fibre length and fibre content on the tensile properties of pineapple leaf fibre (PALF) reinforced unsaturated polyester (UP) composites. PALF as reinforcement agent will be employed with UP to form composite material specimens. The various of fiber length (<0.5, 0.5–1, and 1-2 mm) and fibre content (0, 5, 10 and 15 % by volume) in UP composite have been studied. The fabrication of PALF/UP composites used hand lay-up process, and the specimens for tensile test prepared follow the ASTM D3039. The result obtained from this study show that the 1-2 mm fibre length has higher tensile strength (42 MPa) and tensile modulus (1344 MPa) values compared to fibre length of <0.5 mm (30 MPa and 981 MPa) and 0.5-1 mm (35.40 MPa and 1020 MPa) respectively. Meanwhile, for the effect of various fibre content in study has shown that the increase of fibre content has decreased in tensile strength dan tensile modulus of composites. The increase of fibre content due to poor interfacial bonding and poor wetting of the fibre by unsaturated polyster. The treatment of natural fibre are suggested in order to improve the interfacial adhesion between natural fibre and the unsaturated polyester.


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