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In recent years, serious reduction in petroleum resources and concerns about the usage of synthetic plastics have prompted global communities to accept the use of natural fibres and biopolymers in many products. Lignocellulosic fibre polymer biocomposites have attracted the attention of scientists and engineers because of their wide availability, low carbon emission and biodegradability. Currently, oil palm is one of the main crops cultivated in Malaysia and Indonesia and is regarded as a potential source of lignocellulosic fibres for biocomposites. The cellulosic content of oil palm fibres (OPFs) enhances the mechanical properties of composites. Ensuring the compatibility of OPFs as main constituents with other materials in composites for a specific applications is essential. Mechanical performance in terms of tensile, flexural and impact strength determines an OPF's compatibility. However, no comprehensive reviews focusing on the mechanical properties of OPF biocomposites have been published, and factors influencing mechanical performance, such as interfacial adhesion, stacking sequence, additive, type of polymer and fibre size have not been explored. Some studies have identified the research gaps and deduced that the potential applications of OPFs as reinforcement materials in composites have not been explored.

Cross arms in transmission tower are made up of Chengal wood, which degrade and collapse after a long period of service. This is due to creep deformation, and the rate of degradation is expedited due to exposure to extreme tropical climate. Hence, it is crucial to comprehend the early creep stage, which leads to structural failure. Apart from that, there are several research and industrial application gaps of these cross arms. For instance, creep life analysis of actual cross arms is still unexplored. In this study, the state-of-the-art is related to creep experiments and creep test rig designs, espacially on the creep test of a cantilever beam setup. The experimental methodologies implemented two vital approaches, conventional and accelerated techniques. The specific creep experiments on cantilever beam structure are emphasized and suggested in the manuscript as the building blocks for future design of cantilever creep test rig. This helps to guide future development design of cantilever beam creep test rig by fulfilling the specific criteria related to creep fundamentals, numerical modelling analysis, test operation for data evaluation, and development process. At the end, the challenges and improvements on the criteria existing design of test rigs are elaborated.

A simulated model was developed in order to design and simulate the mechanical properties of a cantilever beam creep testing rig for a full-scale size crossarm in transmission towers. Currently, the Malaysian power grid system is implementing several materials, such as Chengal wood, polymeric composite, and galvanised steel, as crossarm structures. However, there is a lack of study regarding the long-term mechanical behaviour of heavy structures in the literature. Hence, this article explains the design development of creep test rig for a full-scale crossarm structure using CATIA and mechanical simulation (deformation and safety factors) of the product via ANSYS. The test rig will be used to predict the creep life of the cantilever beam structure. In this study, a tall and large base area structure was designed and replicated from an actual tower to elevate the crossarm above the ground level. In order to select the best performance model, a baseline conceptual test rig was generated in CAD modelling, and the finite element analysis was carried out by using a static structural analysis in ANSYS. Four different bracing configurations were incorporated in the baseline model, and the modified structures were then analysed. The results show that the hybrid bracing configuration has enhanced the mechanical properties and safety factors in the baseline model.

Recently, advanced technologies exploit materials from nonrenewable resources such as petroleum, natural gas, metal ores, and minerals. Since the depletion of these resources and environmental issues, it has brought attention to researchers to progress in the development of biodegradable materials from green composites. Most biofibres and biopolymers are obtained from agricultural waste products either from stem, leaf, stalk, or fruit. Nowadays, green composites with well-regulated life span have been widely discussed in numerous fields and applications. Some studies have shown that biofibres and biopolymers have comparable mechanical, thermal, and physical properties with glass fibre and other synthetic polymers. Thus, researchers are progressively narrowing down the development of green composite materials in many high strength applications, such as house deck and automotive components. This review focuses on the background of green composites (natural fibres and biopolymers), the manufacturing processes, potential applications in cross arm structures, and testing evaluations. This article also focuses on the specific current cross arm configurations and the pultrusion process to form squared hollow section beams. Many open issues and ideas for potential applications of green composites are analysed, and further emphases are given on the development of environmentally friendly material structures. Hence, the article is expected to deliver a state-of-art review on manufacturability and perspectives of natural fibre reinforced biopolymer composite cross arms for transmission towers.

Introduction. Male-to-female transgender individuals are known as mak nyahs in Malaysia. Akin to many other countries, mak nyahs face discriminations in securing proper employment, thus many end up in sex trade, exposing them to HIV-related high risk behaviours. This paper aims to investigate the knowledge, attitude, and risk behaviours in HIV/AIDS among mak nyahs in Malaysia. Method. Validated questionnaires in local language were used. Knowledge, attitude, and HIV-related risk behaviours were measured. With respondent-driven sampling method, 54 subjects participated in the survey. IBM SPSS was used for data analysis. Results. Majority of the subjects reported to have HIV-related sexual risk, although only a quarter were sex workers. Misconceptions still remained among the subjects. Inconsistent condom use was common. Adequate knowledge did result in better attitude towards HIV/AIDS. However, multiple regression analysis showed that subjects with higher knowledge in HIV/AIDS tend to have higher sexual risks (ß = 0.320, p = 0.030). Conclusion. Educating the transgender community about HIV/AIDS does not seem to adequately reduce the HIV-related sexual risks. Other approaches, i.e. socio-cultural values and religious practices may be effective to instil higher levels of awareness and self-responsibility in this community to eliminate HIVrelated high risk behaviours. [ABSTRACT FROM AUTHOR]

Introduction: Essential hypertension is a multifactorial disease. Many experimental studies have elucidated the role of oxidative stress and atherosclerosis in the pathogenesis of essential hypertension. Apolipoprotein E is a plasma protein that is found to have antioxidant properties, and it also protects against atherosclerosis. Interestingly, the biological function of apolipoprotein E is strongly affected by polymorphisms in its gene. Based on this evidence, our aim was to investigate the association of apolipoprotein E gene polymorphisms with essential hypertension. Methods: This study was conducted on 70 hypertensive patients and 73 control participants recruited from the Balok governmental health clinic in Kuantan, Pahang. The polymerase chain reaction restriction fragment length polymorphism assay (PCR-RFLP) was used for determination of the apolipoprotein E genotype. Our results were also verified later by direct sequencing of the amplicons. Results: There was no significant association of apolipoprotein E allele or genotype frequencies with hypertensive disease or blood pressure levels, although the E4 allele was slightly more frequent in the hypertensive patients than in the control group (OR=1.055; 0.471-2.359, CI 95%). To improve the precision of the study and to settle the controversies among similar studies meta-analysis was performed; however it revealed a net nonsignificant association between the apolipoprotein E4 allele with essential hypertension in the combined population. Conclusion: Our data and the meta-analysis findings provide evidence that apolipoprotein E gene polymorphism has no direct significant association with hypertension. [ABSTRACT FROM AUTHOR]

Fibre-reinforced polymer (FRP) composites have been selected as an alternative to conventional wooden timber cross arms. The advantages of FRP composites include a high strength-to-weight ratio, lightweight, ease of production, as well as optimal mechanical performance. Since a non-conductive cross arm structure is exposed to constant loading for a very long time, creep is one of the main factors that cause structural failure. In this state, the structure experiences creep deformation, which can result in serviceability problems, stress redistribution, pre-stress loss, and the failure of structural elements. These issues can be resolved by assessing the creep trends and properties of the structure, which can forecast its serviceability and long-term mechanical performance. Hence, the principles, approaches, and characteristics of creep are used to comprehend and analyse the behaviour of wood and composite cantilever structures under long-term loads. The development of appropriate creep methods and approaches to non-conductive cross arm construction is given particular attention in this literature review, including suitable mitigation strategies such as sleeve installation, the addition of bracing systems, and the inclusion of cross arm beams in the core structure. Thus, this article delivers a state-of-the-art review of creep properties, as well as an analysis of non-conductive cross arm structures using experimental approaches. Additionally, this review highlights future developments and progress in cross arm studies.

There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. This review article uniquely highlights the use of green composites from natural fiber, particularly with regard to the development and characterization of chitosan, natural-fiber-reinforced chitosan biopolymer, chitosan blends, and chitosan nanocomposites. Natural fiber composites have a number of advantages such as durability, low cost, low weight, high specific strength, non-abrasiveness, equitably good mechanical properties, environmental friendliness, and biodegradability. Findings revealed that chitosan is a natural fiber that falls to the animal fiber category. As it has a biomaterial form, chitosan can be presented as hydrogels, sponges, film, and porous membrane. There are different processing methods in the preparation of chitosan composites such as solution and solvent casting, dipping and spray coating, freeze casting and drying, layer-by-layer preparation, and extrusion. It was also reported that the developed chitosan-based composites possess high thermal stability, as well as good chemical and physical properties. In these regards, chitosan-based "green" composites have wide applicability and potential in the industry of biomedicine, cosmetology, papermaking, wastewater treatment, agriculture, and pharmaceuticals.

Biocomposites are materials that are easy to manufacture and environmentally friendly. Sugar palm fibre (SPF) is considered to be an emerging reinforcement candidate that could provide improved mechanical stiffness and strength to the biocomposites. Numerous studies have been recently conducted on sugar palm biocomposites to evaluate their physical, mechanical and thermal properties in various conditions. Sugar palm biocomposites are currently limited to the applications of traditional household products despite their good thermal stability as a prospective substitute candidate for synthetic fibres. Thus, thermal analysis methods such as TGA and DTG are functioned to determine the thermal properties of single fibre sugar palm composites (SPCs) in thermoset and thermoplastic matrix as well as hybrid SPCs. The biocomposites showed a remarkable change considering thermal stability by varying the individual fibre compositions and surface treatments and adding fillers and coupling agents. However, literature that summarises the thermal properties of sugar palm biocomposites is unavailable. Particularly, this comprehensive review paper aims to guide all composite engineers, designers, manufacturers and users on the selection of suitable biopolymers for sugar palm biocomposites for thermal applications, such as heat shields and engine components., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Polymer composites filled with metal derivatives have been widely used in recent years, particularly as flame retardants, due to their superior characteristics, including high thermal behavior, low environmental degradation, and good fire resistance. The hybridization of metal and polymer composites produces various favorable properties, making them ideal materials for various advanced applications. The fire resistance performance of polymer composites can be enhanced by increasing the combustion capability of composite materials through the inclusion of metallic fireproof materials to protect the composites. The final properties of the metal-filled thermoplastic composites depend on several factors, including pore shape and distribution and morphology of metal particles. For example, fire safety equipment uses polyester thermoplastic and antimony sources with halogenated additives. The use of metals as additives in composites has captured the attention of researchers worldwide due to safety concern in consideration of people's life and public properties. This review establishes the state-of-art flame resistance properties of metals/polymer composites for numerous industrial applications.

Polymorphisms within the beta2-adrenergic receptor (ADRB2) gene have been repeatedly linked to hypertension. Among the ADRB2 polymorphisms detected, Arg16Gly and Gln27Glu codons are considered the two most important variations. The amino acid substitution at these codons may lead to abnormal regulation of ADRB2 activity. The aim of the present study was to assess the association between ADRB2 polymorphisms and hypertension. This case-control study consisted of 100 unrelated subjects (50 hypertensive and 50 matched normal controls). Arg16Gly and the Gln27Glu polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism assay. There were no significant evidence of association in allelic and genotypes distribution of Arg16Gly and Glu27Gln with blood pressure and hypertension. These findings suggest that the variation within codon 16 and 27 of ADRB2 gene were unlikely to confer genetic susceptibility for hypertension in our population samples.