Background: Coronavirus disease 2019 (COVID-19), a novel pneumonia disease originating in Wuhan, was confirmed by the World Health Organization on January 12, 2020 before becoming an outbreak in all countries. Outbreak situation: A stringent screening process at all airports in Malaysia was enforced after the first case outside China was reported in Thailand. Up to April 14, 2020, Malaysia had reported two waves of COVID-19 cases, with the first wave ending successfully within less than 2 months. In early March 2020, the second wave occurred, with worrying situations. Actions taken: The Government of Malaysia enforced a Movement Control Order starting on March 18, 2020 to break the chain of COVID-19. The media actively spread the hashtag #stayhome. Nongovernmental organizations, as well as prison inmates, started to produce personal protective equipment for frontliners. Various organizations hosted fundraising events to provide essentials mainly to hospitals. A provisional hospital was set up and collaborations with healthcare service providers were granted, while additional laboratories were assigned to enhance the capabilities of the Ministry of Health. Economic downturn: An initial financial stimulus amounting to RM 20.0 billion was released in February 2020, before the highlighted PRIHATIN Package, amounting to RM 250 billion, was announced. The PRIHATIN Package has provided governmental support to society, covering people of various backgrounds from students and families to business owners.
Since ancient Egypt, orthosis was generally made from wood and then later replaced with metal and leather which are either heavy, bulky, or thick decreasing comfort among the wearers. After the age of revolution, the manufacturing of products using plastics and carbon composites started to spread due to its low cost and form-fitting feature whereas carbon composite were due to its high strength/stiffness to weight ratio. Both plastic and carbon composite has been widely applied into medical devices such as the orthosis and prosthesis. However, carbon composite is also quite expensive, making it the less likely material to be used as an Ankle-Foot Orthosis (AFO) material whereas plastics has low strength. Kenaf composite has a high potential in replacing all the current materials due to its flexibility in controlling the strength to weight ratio properties, cost-effectiveness, abundance of raw materials, and biocompatibility. The aim of this review paper is to discuss on the possibility of using kenaf composite as an alternative material to fabricate orthotics and prosthetics. The discussion will be on the development of orthosis since ancient Egypt until current era, the existing AFO materials, the problems caused by these materials, and the possibility of using a Kenaf fiber composite as a replacement of the current materials. The results show that Kenaf composite has the potential to be used for fabricating an AFO due to its tensile strength which is almost similar to polypropylene's (PP) tensile strength, and the cheap raw material compared to other type of materials.
Advanced materials were used and are being implemented in structural, mechanical, and high-end applications. Contemporary materials are used and being implemented in structural, mechanical, and high-end applications. Composites have several major capabilities, some of them being able to resist fatigue, corrosion-resistance, and production of lightweight components with almost no compromise to the reliability, etc. Nanocomposites are a branch of materials within composites, known for their greater mechanical properties than regular composite materials. The use of nanocomposites in the aerospace industry currently faces a research gap, mainly identifying the future scope for application. Most successes in the aerospace industry are because of the use of suitable nanocomposites. This review article highlights the various nanocomposite materials and their properties, manufacturing methods, and their application, with key emphasis on exploiting their advanced and immense mechanical properties in the aerospace industry. Aerospace structures have used around 120,000 materials; herein, nanocomposites such as MgB2, multi-walled carbon nanotubes, and acrylonitrile butadiene styrene/montmorillonite nanocomposites are discussed, and these highlight properties such as mechanical strength, durability, flame retardancy, chemical resistance, and thermal stability in the aerospace application for lightweight spacecraft structures, coatings against the harsh climate of the space environment, and development of microelectronic subsystems.
Aerospace structures are prone to impact which affected their residual strength. The aim of this paper to investigate the impact and after-impact behaviour of multi-walled carbon nanotube (MWCNTs) as nanofiller enhanced flax/carbon fibre composites (FLXC) and flax/glass fibre composites (FLXG) hybrid composites. Wet lay-up method was used to fabricate the hybrid composites. The hybrid composites were impacted with impact energies ranging from 5J to 20J, with different types of surface susceptible to the impactor to compare their response under loading. Compression after impact (CAI) testing were done to evaluate the after-impact properties of the hybrid composites. Obtained results found that FLXG composites impacted at glass surface (G-FLX) showed better impact properties compared to C-FLX composites. In another end, it was found that the compressive strength of FLXG composites is higher compared to FLXC composites due to severe damage occurred on FLXC composites surface compared to FLXG composites. Therefore, from the results, it can be concluded that FLXG hybrid composites shows good behaviour to be applied as the interior and functional surfaces inside an aircraft.
This study aims to explore the mechanical properties of hybrid glass fiber (GF)/sisal fiber (SF)/chitosan (CTS) composite material for orthopedic long bone plate applications. The GF/SF/CTS hybrid composite possesses a unique sandwich structure and comprises GF/CTS/epoxy as the external layers and SF/CTS/epoxy as the inner layers. The composite plate resembles the human bone structure (spongy internal cancellous matrix and rigid external cortical). The mechanical properties of the prepared hybrid sandwich composites samples were evaluated using tensile, flexural, micro hardness, and compression tests. The scanning electron microscopic (SEM) images were studied to analyze the failure mechanism of these composite samples. Besides, contact angle (CA) and water absorption tests were conducted using the sessile drop method to examine the wettability properties of the SF/CTS/epoxy and GF/SF/CTS/epoxy composites. Additionally, the porosity of the GF/SF/CTS composite scaffold samples were determined by using the ethanol infiltration method. The mechanical test results show that the GF/SF/CTS hybrid composites exhibit the bending strength of 343 MPa, ultimate tensile strength of 146 MPa, and compressive strength of 380 MPa with higher Young’s modulus in the bending tests (21.56 GPa) compared to the tensile (6646 MPa) and compressive modulus (2046 MPa). Wettability study results reveal that the GF/SF/CTS composite scaffolds were hydrophobic (CA = 92.41° ± 1.71°) with less water absorption of 3.436% compared to the SF/CTS composites (6.953%). The SF/CTS composites show a hydrophilic character (CA = 54.28° ± 3.06°). The experimental tests prove that the GF/SF/CTS hybrid composite can be used for orthopedic bone fracture plate applications in future.
The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.
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