M.J.M. Ridzuan

Mechanical, thermal and morphological characterisation of 3D porous Pennisetum purpureum/PLA biocomposites scaffold

The mechanical, thermal, and morphological properties of a 3D porous Pennisetum purpureum (PP)/polylactic acid (PLA) based scaffold were investigated. In this study, a scaffold containing P. purpureum and PLA was produced using the solvent casting and particulate leaching method. P. purpureum fibre, also locally known as Napier grass, is composed of 46% cellulose, 34% hemicellulose, and 20% lignin. PLA composites with various P. purpureum contents (10%, 20%, and 30%) were prepared and subsequently characterised. The morphologies, structures and thermal behaviours of the prepared composite scaffolds were characterised using field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The morphology was studied using FESEM; the scaffold possessed 70-200μm-sized pores with a high level of interconnectivity. The moisture content and mechanical properties of the developed porous scaffolds were further characterised. The P. purpureum/PLA scaffold had a greater porosity factor (99%) and compression modulus (5.25MPa) than those of the pure PLA scaffold (1.73MPa). From the results, it can be concluded that the properties of the highly porous P. purpureum/PLA scaffold developed in this study can be controlled and optimised. This can be used to facilitate the construction of implantable tissue-engineered cartilage.

Effects of Alkaline Concentrations on the Tensile Properties of Napier Grass Fibre

This paper presents an experimental investigation of the effects of alkaline treatment on the tensile properties of Napier grass fibres. The effect of different concentrations of NaOH aqueous solutions on the morphology and structure of the fibres were studied. The fibres were treated with 5%, 10%, and 15% of Sodium hydroxide (NaOH) concentration for 24 hours of soaking time. The single fibre tests were then performed in accordance with ASTM D3822-07 standard. The morphology of the fibres before and after alkali treatment was observed with a Metallurgical Microscope MT8100. The results show that the physical properties were varied after the treatments and 10% concentration of NaOH treatment yield the maximum tensile strength and elongation of the fibre at 172 MPa and 5.7% respectively. Morphology observation found that the fibre became thinner, and the surface roughness of the fibres increased with the increment of NaOH concentration.

Pyrolysis of Empty Fruit Bunch (EFB) in a vertical fixed bed reactor

Uncontrolled uses of fossil fuels lead to serious energy problems and since Malaysia is one of the largest producers of palm oil in the world, it has caused a lot of waste such as empty fruit bunches (EFB) which can actually be converted into renewable energy via pyrolysis. In this work, firstly the characterizations of the EFB were analyzed such as elemental, proximate and component analysis. The pyrolysis experiment of empty fruit bunch using vertical fixed-bed reactor was conducted at different pyrolysis temperature range from 300 - 600 °C and the particle size of EFB was also varied from 125-250 μm with constant nitrogen flow rate of 100 cm3/min, heating rate of 30 °C/min, and 30 minutes hold time. For the effect of temperature, the optimum pyrolysis temperature was 500 °C to produce maximum yield of bio-oil which is 39.2 wt. % while 46.13 wt. % is the highest bio-oil yield produced at size of 500-710 μm for the effect of particle size. The analysis on bio-oil was conducted by using Fourier Transform Infrared (FTIR) with the results shows for the presents of phenol/alcohol group, ketones and C-O bond. The bio-oil obtained is in the acidic condition with pH 3.5.

COP Improvement of Thermoelectric Cooler through the Optimization of Heat Dissipation System

This paper presents theoretical and experimental works on the effect of heat transfer for a thermoelectric (TE) cooling system. The study focuses on thermal performance of the system through the optimisation of heat dissipation system for two prototypes that have aluminium and copper heat sink design, respectively. The study revealed that heat sink base area and fin height influenced thermal performance.

Development of Pico-Hydro Turbine for Domestic Use

As many research and study were conducted worldwide in order to explore the different alternatives and renewable energy resources, this work come out with the descriptions of the initial testing conducted on the prototype of pico-hydro generation system for the purpose of investigating its performance. The kinetic energy hold by water flow in the domestic pipes was obtained to have potential in generating electricity power for energy storage purposes while conducting routine activities such as laundry, cook and bathe. The water pressure and water flow inside the pipe from utility’s main tank that used for those usual activities are used to rotate small scale hydro turbine to drive a generator for electrical power generation. Results from the test significantly show the convinced reading in recorded voltage as it is a count to propose the system is feasible for electrification of energy storage purpose and indicate the prospect for further improvement and future research.

The effects of alkali treatment on the mechanical and morphological properties of Pennisetum purpureum/glass-reinforced epoxy hybrid composites

ABSTRACT The effects of alkali treatment on the mechanical properties, void contents and morphological of Pennisetum purpureum/glass-reinforced epoxy hybrid composites were studied. The composites were produced using the vacuum infusion method. Pennisetum purpureum fibres were treated with 5 and 10% dilute sodium hydroxide (NaOH) solution for 6 h. The epoxy resin was mixed with either the treated or untreated Pennisetum purpureum/glass fibres to a ratio of 70:30 (by volume). Tensile and flexural tests were performed on the composites in accordance with ASTM D638 and ASTM D790, respectively. The hybrid composites that contained 5% NaOH-treated Pennisetum purpureum fibres exhibited the greatest tensile and flexural strengths with lower void contents. Field-emission scanning electron microscopy fractography supported the findings showing lesser voids and fibre pull-outs suggesting good interfacial bonding between the matrix and reinforcement. The reduced of the void contents is suspected due to the reduced hemicellulose content within the treated Pennisetum purpureum fibre.

Tensile properties of compressed moulded Napier/glass fibre reinforced epoxy composites

This paper describes the experimental investigation of the tensile properties of compressed moulded Napier grass fibres reinforced epoxy composites. The effect of treatment 5% sodium hydroxide (NaOH) concentrated solution and hybridization of Napier with CSM E-glass fibres on tensile properties was also studied. The untreated and treated Napier fibres with 25% fibre loading were fabricated with epoxy resin by a cold press process. 7% fibre loading of CSM glass fibre was hybrid as the skin layer for 18% fibre loading of untreated Napier grass fibre. The tensile tests were conducted using Universal Testing Machine in accordance with ASTM D638. The tensile properties of the untreated Napier/epoxy composites were compared with treated Napier/epoxy and untreated Napier/CSM/epoxy composites. The results demonstrated that the tensile performance of untreated Napier fibre composites was significantly improved by both of the modification; alkali treatment and glass fibre hybridization. Napier grass fibres showed promising potentials to be used as reinforcement in the polymer based composites.

Water absorption behaviour of hybrid interwoven cellulosic fibre composites

The present paper investigated the water absorption behaviour of hybrid interwoven cellulosic fibre composites. Hybrid composites consisting of interwoven kenaf/jute and kenaf/hemp yarns were prepared by an infusion manufacturing technique that used epoxy as the polymer matrix. Water absorption test was conducted as elucidated in ASTM D570 standard by immersing the composite samples in tap water at room temperature until reaching their water content saturation point. For each composite type, average from five samples was recorded and the percentage of water uptake against the square root of time was plotted. As the effect of hybridization, the water uptake, diffusion and permeability coefficient of the hybrid composites were lesser than the individual woven composites.

Effect of elevated temperatures on flexural strength of hybrid Napier/glass reinforced epoxy composites

The effects of elevated temperatures on the flexural strength of hybrid Napier/glass reinforced epoxy composites were investigated. Hybrid composites laminates were fabricated using untreated, 5%, or 10% alkali-treated Napier fibres with woven E-glass fibres and epoxy resin. The composites were manufactured using a vacuum infusion process; the volume fraction of the Napier, glass fibres and epoxy resin were 24%, 6% and 70% respectively. When tested at room temperature (RT), the maximum flexural strength was recorded for the hybrid composites with the 5% alkali-treated Napier fibres. When the test temperature greater than 60°C, the matrix cracking and delamination were occurred due to the temperature that approached the glass transition temperature (Tg) of the composites, which resulted in a reduction of the flexural strength. The fracture surface morphologies indicated that the 5% alkali-treated Napier fibres improved the fibre-matrix interfacial bonding of the hybrid Napier/glass reinforced epoxy composites.

Effect of stress ratio on the fatigue behaviour of glass/epoxy composite

The effect of stress ratio on the fatigue behaviour of the GFRE composite has been investigated. The glass fibre reinforced epoxy (GFRE) composite plates were fabricated using vacuum infusion method. Static tensile was performed in accordance with the ASTM D5766 standard, and the cyclic test was conducted according to ASTM D3479 with three different stress ratio, R = 0, 0.5, -1. Static tensile tests were carried out to determine the ultimate strength of this composite. Subsequently, fatigue tests loads ranging from 30% to 90% of the ultimate load were applied to each specimen. The S–N curve of different stress ratio loading of fibreglass/epoxy composites was then established. The results show that the number of cycles to failure increases as the loading is decreased. The specimens for fatigue tests loads 30% at R = 0 and -1 recorded the highest number of cycles at 2 million cycles. The results obtained from this test indicated a significant life reduction for R = -1 compared with the tension-tension loading, with the life reduction for R = -1 being greatest. The fatigue behaviour of the GFRE composite materials is not only influenced by the percentage of fatigue tests load but with different of stress ratio.