Preparation and characterization of Styrene-Methyl Methacrylate in Deproteinized Natural Rubber Latex (SMMA-DPNR)

The graft polymerization of Styrene and Methyl Methacrylate (MMA) onto deproteinized natural rubber latex (SMMA-DPNR) was carried out using ammonium peroxy disulfate (N2H8O8S2) as an initiator. The suitable reaction conditions based on the higher monomer conversion was determined. The SMMA-DPNR at 6 hours reaction time was successfully prepared with degree of conversion more than 99 %. The copolymers composition of the resultant SMMA-DPNR was obtained using 1H-NMR Spectroscopy. As expected, composition of styrene in DPNR was higher than that of MMA due to the higher reactivity ratio of styrene monomer as compared to MMA monomer and the structure of the NR backbone

Pultruded Kenaf Fibre Reinforced Composites: Effect of Different Kenaf Fibre Yarn Tex

AbstractManufacturing high performance composites from natural fibres is one of an ambitious goal currently being pursued by researchers across the globe. The ecological benefits of this material among many others are environmentally friendly and do not cause health problems. In terms of sustainability, the natural fibre is an appropriate alternative candidate to replace the synthetic and other types of reinforcement since it is a renewable resource. In order for natural fibre reinforced composite to become competitive, it has to accommodate the processing avenues of which has long being associated with its synthetic counterpart. Among those proven technology in manufacturing advanced engineering component is pultrusion. In this paper, an attempt has been made to produce pultrudedkenaf fibre reinforced unsaturated polyester composites via pultrusion. The properties of the pultrudedkenaf fibre reinforced composites with different kenaf yarn sizes are reported and compared. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties

Damage Characterization of Polypropylene Honeycomb Sandwich Panels Subjected to Low-Velocity Impact

The post-test deformation and failures of sandwich composites may involve complex interactions between various failure mechanisms. In this study, the extent of impact damages and response of the thermoplastic honeycomb sandwich are analysed through energy profile diagrams and associated load history curves. The degree of the postimpact damages of the sandwich is further characterized using an optical surfaces metrology analysis. The thickness of the honeycomb was found to influence the extent of the damage which occurred following the low-velocity impact. Thicker core was able to sustain a higher load as well as the energy absorption before total failure occurred

DYNAMIC BEHAVIOUR OF PAPER HONEYCOMB SANDWICH PANELS

Low velocity impact tests have been conducted on paper honeycomb sandwich panels. Two panel thicknesses with span length of 100 mm are used; these are 35 mm and 41 mm, respectively. The dynamic behavior of each paper honeycomb thickness is investigated using two types of indentors: hemispherical and bar. The effect of indentor, and specimen length are studied. This includes the pattern of loaddisplacement curve collapse load and energy absorbed. It concludes that the dynamic collapse load on 41 mm thickness for hemispherical indentor increases by 5% compared with 35 mm. The impact energy absorbed for hemispherical indentor increases by 36%

Green Composites from Ionic Liquid-Assisted Processing of Sustainable Resources: A Brief Overview

The massive use of synthetic, petroleum-based polymeric composites has disturbed the fragile environmental equilibrium of our planet. Composites made solely from polysaccharides can offer unique intrinsic properties such as renewability, biodegradability, easy availability, eco-friendliness, facile processing, flexibility, and exciting physico-mechanical characteristics. The development of green processing of lignocellulosic materials and bio-based polymers such as cellulose, starch, chitin, and chitosan, the most abundant biorenewable materials on earth, is urgent from the perspectives of both environmental protection and sustainability in materials industries. Recently, the enormous potential of ionic liquids (ILs) as an alternative to ecologically harmful conventional organic solvents has been well recognized. Presently, a wide range of pronounced approaches have been explored to further improve the performance of ionic liquid-based processing of polysaccharides for green composite manufacturing. This review presents recent technological developments in which the advantages of ionic liquids as a dissolution medium for polysaccharides for production of plethora of green composites have been gradually realized

Pultruded Natural Fibre Reinforced Composites: Preparation, Properties And Applications

Environmentally friendly composites are today highly required by utilizing natural fibers as reinforcement combined with biodegradable polymer as matrices

Study On Dynamic Mechanical Properties Of Pultruded Kenaf Fiber Reinforced Composites.

This paper reports the dynamic mechanical properties of pultruded kenaf fiber reinforced composites

The tensile evaluation of the Epoxy/Keratin short fibre as new composites / Ahmad Zafir Romli, Mohd Hanafiah Abidin and Hazizan Md Akil

Production of bio-composites using biodegradable filler/fibre or matrix has been increasing steadily for the past decade. In the case of fibre reinforced polymer composites, natural fibres such as jute, hemp and kenaf have been widely reported. Apart from cellulosic based natural fibre, there are other potential fillers from animal based by-products such as keratin from chicken feathers. In this study, an epoxy/keratin composite has been produced using a pressure assisted hand lay-up technique to form flat homogenized board. The percentage feather content by weight was varied accordingly (i.e. 10, 20, 30, 40 and 50 %). The board underwent standard tensile strength testing at 5mm.min-1 and elucidated that the ultimate tensile strength and strain decreases as the feather composition percentage increases. The Young’s modulus indicated little effect with increasing feather composition percentage. A fractured piece of sample produced from the tensile testing was evaluated with respect to fracture behaviour using scanning electron microscopy (SEM). The tensile testing indicates that the composite with the maximum feather composition percentage (50 %) has the potential to be used in non-structural applications

Recent Advances in Deep Learning Techniques for Face Recognition

In recent years, researchers have proposed many deep learning (DL) methods for various tasks, and particularly face recognition (FR) made an enormous leap using these techniques. Deep FR systems benefit from the hierarchical architecture of the DL methods to learn discriminative face representation. Therefore, DL techniques significantly improve state-of-the-art performance on FR systems and encourage diverse and efficient real-world applications. In this paper, we present a comprehensive analysis of various FR systems that leverage the different types of DL techniques, and for the study, we summarize 168 recent contributions from this area. We discuss the papers related to different algorithms, architectures, loss functions, activation functions, datasets, challenges, improvement ideas, current and future trends of DL-based FR systems. We provide a detailed discussion of various DL methods to understand the current state-of-the-art, and then we discuss various activation and loss functions for the methods. Additionally, we summarize different datasets used widely for FR tasks and discuss challenges related to illumination, expression, pose variations, and occlusion. Finally, we discuss improvement ideas, current and future trends of FR tasks.Comment: 32 pages and citation: M. T. H. Fuad et al., "Recent Advances in Deep Learning Techniques for Face Recognition," in IEEE Access, vol. 9, pp. 99112-99142, 2021, doi: 10.1109/ACCESS.2021.309613

Medical Implant Production using Three-Dimensional Printing as a Potential Manufacturing Process in Medical Application / Siti Norsyahirah Abdul Razak ...[et al.]

Three-dimensional printing (3DP) is one of the rapid prototyping (RP) technologies that can be a potential manufacturing process in medical application such as implant manufacturing. 3D printing is a layer manufacturing technique and can act as direct production of medical implant. In this research, implant manufacturing process by using MakerBot Replicator 2X 3D printer is proposed as improved alternative of the previous conventional implant production method. This study attempted to investigate the production time and production cost of medical implant manufacturing as compared to the conventional methods. As compared to the conventional method of implant manufacturing, the production time is much shorter than expected and the production cost is more affordable. The results show that 3D printer which is MakerBot Replicator 2X is feasible for direct production of implant manufacturing