Green composite material has become the most desired material to replace polymer composites made from fossil oil. Besides having advantages over its biodegradability and quality performances, the material sources are abundant and renewable. Therefore, this research focused on developing green composite which is derived from a combination of pineapple leaf fibers (PALF) and Polylactide (PLA). PALF is extracted from pineapple leaves which are easily found during harvesting pineapple plantation. In order to study the influences of different fibres characterization, the fibres were extracted from different types of pineapple available in Malaysia, namely Moris Gajah, Jasopine, Maspine, and N36. The main objective of this study was to investigate the physical and mechanical properties of this green composite. The physical testing was carried out to determine water absorption while the tensile and bending tests were conducted for mechanical testing. For the purpose of comparing the material properties, PALF reinforced polypropelene (PP) was developed too. Based on the result, Jasopine fibre shows the highest tensile and flexural strength for the combination of both polymers in comparison to the other types of PALF.

Wearableassistive devices such as passive exoskeletonhavebeen recognized as one of the effective solutions to assist people inindustrialwork, rehabilitation, elderly care, military and sports. Thedesign and development of a passive exoskeletonthat emphasizes on satisfying and fulfilling users’ requirements and users’ experience areessential to ensure the device remains competitive in the global market. Agood user experience of using an exoskeletonstimulates users’ satisfaction, as contemporary users are not only considering basic functional features but alsofascinated by perception values such as aesthetics and enjoyment. Themain purpose of this article is to review the critical factors that are influencing user experience before, during and after utilizing a passive exoskeleton. The authors had searched relevant articles from academic databases such as Google Scholar, Scopus and Web of Science as well as free Google search for the publicationperiod from 2001to 2021. Several search keywords were used such as ‘passive exoskeleton +user experience’, ‘passive exoskeleton + industry’, ‘passive exoskeleton + rehabilitation’, ‘passive exoskeleton + military’, ‘passive exoskeleton + sports’,‘passive exoskeleton + sit-stand’, and passive exoskeleton + walking’. This online search found that a total of 236 articles related to the application of passive exoskeleton in the area of industry, rehabilitation, military and sports. Out of this, 81 articles were identified as significant references and examined thoroughly to prepare the essence of this paper. Based on thesearticles, the authors revealed that the engineering design, usability, flexibility, safety and ergonomics, aesthetics, accessibility, purchase cost, after-sales service and sustainability are the critical factorsthatare influencing user experience whenemployingpassive exoskeleton.

Graphene nanoplatelets (GNPs), a newly discovered nanomaterial, promise a great potential in many technological applications. However, the direct usage of GNPs was limited due to several surface property factors that require innovative modifications and treatments. In this study, the GNPs surface treatment is carried out by using a covalent and non-covalent approach. The success of the treatment was determined and evaluated through the Raman and FTIR spectroscopy analysis, FESEM, TEM and XRD morphological observation. A strong vibration of Raman peak at 2081.11 cm-1 represent a possible covalent bonding of C=C due to the ATPS-silane treatment, while the characteristic peak at 1013.82 cm-1 indicates the aromatic ring nature of polyimide that non-covalently associated with C-H and C-C, as well as C-O-C linkage from the polyether. From the IR spectroscopy, the covalent treatment on GNPs was occurred through the dehydration mechanism while hydrogen bonding in the multiple structures of –OH that associated to the carboxylic acids was obviously involved for non-covalent treatment of GNPs. TEM observation of GNPs-PEI (polyetherimide) revealed a unique phenomenon of a polymeric adsorption as represented by a nanosize gray dot morphology in between of the GNPs platelets. In overall, the facile procedure of the surface treatment that was applied in this study is reliable to yield a different type of GNPs characteristic of covalent and non-covalent surface active, which may open up broad possibilities for various cutting edges applications.

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This paper presents the modelling of the mechanical properties of the bobbin friction stir welded of 6 mm thick AA1100 with control factors of spindle and welding speeds. Face-centered composite design (FCCD) was used to design the experimental work and the results of the responses and the combination of factors were analyzing through analysis of variance (ANOVA). From ANOVA, the result indicates that both spindle and welding speed influence significantly the tensile strength and average hardness at SZ of AA1100. The optimum factors for maximum tensile strength and average hardness of the AA1100 were 950 rpm and welding speed of 130 mm/min. Both models giving a relative small percentage error of 0.8 % and 1.64 % for tensile strength model and average hardness in stir zone (SZ) region, respectively, thus indicate the models were adequate.