This paper presents a study on the effect of Arenga Pinnata fibre volume fraction on the tensile and compressive properties of Arenga Pinnata fibre reinforced epoxy composite (APREC). The composites were produced using four different Arenga Pinnata fibre volume contents, which were 10vol%, 15vol%, 20vol%, and 25vol%, in unidirectional (UD) fibre alignment. Tensile and compression tests were performed on all APREC specimens in order to investigate the effect of fibre volume fraction on modulus of elasticity, strength and strain to failure. The morphological structure of fractured specimens was observed using scanning electron microscopy (SEM) in order to evaluate the fracture mechanisms involved when the specimens were subjected to tensile or compressive loading. The results indicated that the higher the amount of Arenga Pinnata fibres, the higher the stiffness of the composites. This is shown by the increment of tensile and compressive modulus of the specimens when the fibre volume content was increased. Tensile modulus increased up to 180% when 25vol% Arenga Pinnata fibre was used in APREC compared to Pure Epoxy specimen. It can also be observed that the tensile strength of the specimens increased 28% from 53.820 MPa (for Pure Epoxy) to 68.692 MPa (for Epoxy with 25vol% APREC addition). Meanwhile, compressive modulus and strength increased up to 3.24% and 9.17%, respectively. These results suggest that the addition of Arenga Pinnata fibres significantly improved the tensile and compressive properties of APREC.
Kenaf fibre is one of the natural fibers that has received much attention of many researchers because of its good properties and flexible use. Kenaf fibre composites have been proposed as interior building materials. In this study, the recycling effect on the kenaf PVC wall panel is focused. The main objective of this study is to determine the mechanical properties of different types of kenaf PVC wall panels. The samples were formulated based on the first and third recycling process. The specimens were subjected to several types of tests, namely, tensile, izod impact, flexural and hardness based on ASTM D3039, ASTM D256, ASTM D7264 and ASTM D785, respectively. The results indicate that the mechanical properties of the third recycled kenaf PVC wall panel product is better than the virgin and first recycled specimen. This shows that the recycling process enhances the mechanical properties of the product. On the other hand, the hardness of the specimen decreases after first recycling due to the reheating effect.
This study presents an investigation about the effect of size variation on mechanical
performance of square core interlocking structures, by using finite element analysis
(FEA). The material used in this study is flax fibre reinforced polypropylene (PP)
composite. Abaqus software was used for modelling and visualizing number of six
interlocking honeycomb structures with different cell sizes and heights. In the first
analysis, Abaqus/standard was performed on the perfect models by applying quasistatic
loading to identify the imperfection shape and obtaining the buckling Eigenmodes
for the models, then the Eigen-modes from abaqus/standard were imported
to abaqus/explicit to run post-buckling analysis and simulate the overall imperfection
behaviour of models. The numerical results from the finite element analysis
simulation were used to plot load-displacement curve to each model. The area under
the load-displacement curve represents the total absorbed energy, energy absorption
per unit mass indicates the specific energy absorption, and the highest value of
specific energy absorption represents the optimum size. The findings demonstrated
that the square interlocking structure exhibits good energy absorption performance
in some geometrical cases, and also revealed that the natural fibre composites have
unique energy absorption capability under quasi-static loads.
There is an increasing demand for fibre rich food and food ingredients. In this study, pumpkin pulp, unripe banana pulp, unripe mango pulp and peel which are high in dietary fibre were processed into flour and substituted at 5% level for wheat flour in a composite flour crackers formulation. The control crackers comprised of 100% wheat flour. Sensory evaluation was conducted using a 9-point hedonic scale with 31 panelists evaluating the crackers based on colour, crrispiness, taste and overall acceptance. Different types of composite flour crackers were not significantly different (p≤0.05) in term of crispiness. For colour, taste and overall acceptance, the pumpkin, banana and control crackers differ significantly (p≤0.05) with the mango pulp and mango peel crackers.
The present study was conducted to investigate the effect of oyster mushroom (Pleurotus sajorcaju,
PSC) addition to partially replace coconut milk powder on nutritional composition and
sensory values of Herbal Seasoning (HS). This study evaluates the nutritional composition,
dietary fibre and sensory acceptance of HS that processed using six different formulations
with different levels of PSC powder, namely 0% (A), 20% (B), 40% (C), 60% (D), 80% (E)
and 100% (F). The use of PSC powder substantially brought down the fat content of HS.
The fat content of PSC-based HS was ranged from 13.82±0.84% to 8.16±0.74%. The protein
content showed an increasing trend in line with increasing of PSC powder ranging from 7%
to 12%.Substitution of coconut milk powder with PSC powder resulted in significantly higher
(p0.05).The panels preferred HS formulated with PSC powder since its
enhance colour and viscosity attributes of the products. In brief, HS formulated with more than
40% PSC powder is recommended since it has significant nutrients and palatably accepted by
sensorial panellists.
Palm kernel cake (PKC), a by-product of the palm oil industry is limited in its use as a feed ingredient for poultry due to its high fibre and lignin content. The presence of these antinutritive components is the result of shells contaminating the by-product. The nutritive value of PKC has to be improved in order to increase its inclusion rate in poultry diet. In this study, PKC was subjected to a separation method using static cling and electrostatic separation to removethe shells present in PKC. Response surface methodology based on Box-Behnken design was used to optimize the separation method with moisture content (8 to 18%), particle size distribution (0.5 to 2.5 mm) and feed rate (20 to 200 g/min) as the independent variables evaluated. According to the regression coefficients and significance of the quadratic polynomial model, the optimum separation parameters were as follows: 13% PKC moisture content;
The purpose of this study is to compare the tensile strength between additional polystyrene into coconut meat husk reinforced fiber composite. Composite were produced by using hand layup technique. It is seen that with the additional of polystyrene into the coconut meat husk reinforced polyester composites showed the increment tensile strength value compared to the non-added polystyrene which indicates that effective stress transfer between the fiber, matrix and polystyrene.
Fibre-rich manure derived from grass-fed cattle showed significantly higher intrinsic sorption efficiency on Cr(VI) solution as compared to corncob, sawdust and cogon grass. This observation could be attributed to the ligneous nature and rough surface morphology of the cattle manure. Four-factor, three-level, face-centred composite design (FCCD) suggested the process was greatly affected by initial pH of the solution, contact time and sorbent dosage (p50% adsorption efficiency. It is predicted that both physisorption and chemisorption are involved in the sorption process.
Cellulose acetate (CA) is an interesting material due to its wide spectrum of utilities across different domains ranging from absorbent to membrane filters. In this study, polystyrene (PS) nanofibres, and cellulose acetate/polystyrene (CA/PS) blend nanofibres with various ratios of CA: PS from 20: 80 to 80: 20 were fabricated by using electrospinning technique. The SEM images show that the nanofibres exhibited non-uniform and random orientation with the average fibre diameter in the range of 100 to 800 nm. It was found that the incorporation of PS had a great effect on the morphology of nanofibre. At high proportion of PS, no or less beaded CA/PS nanofibres were formed. Thermal properties of the composite nanofibres were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. The TGA results showed thermal stability of CA/PS nanofibres were higher than pristine CA.
This paper reports on the preparation of magnetic lumen loaded handsheets from bleached and unbleached mixed tropical hardwood kraft pulps. The lumen coating technique is a physical approach whereby fillers were deposited inside the fibre lumen. In order to produce magnetically responsive fibres, magnetic fillers were loaded into the fibre lumen. The magnetic filler chosen was magnetite which is usually used to make mylar as found in a diskette. Low and high molecular weights of polyacrylamide (PAM) were used as retention aids. The effect of different molecular weight of PAM on filler content in the bleached and unbleached handsheets were studied. The results showed that the amount of fillers deposited in the pulp fibres increased with increasing molecular weight of PAM using both pulps. However the bleached pulps gave better lumen loading than the unbleached when using high molecular weight of PAM.
Various types of natural fibre-rich ingredients are added into bakery-based products to improve their fibre content for health promotional purposes. However, most of these products are frequently added with imported dietary fibre ingredients. The aim of this study was to develop bakery products incorporated with young corn powder (YCP) and to evaluate the effects on physicochemical properties and sensory acceptabilities. Dried young corn was used to substitute wheat flour in biscuit and muffin formulations at different levels (0, 10, 20 and 30%). The effects of YCP incorporation on proximate compositions, physical characteristics, texture profile and sensory evaluation of both bakery products were investigated. The present results showed that YCP had significantly increased protein and total dietary fibre contents of both biscuit and muffin. Hardness attribute of both products increased in line with the level of YCP addition. Interestingly, biscuit and muffin containing 10% YCP received better score than the control and other formulations for most of the sensorial attributes judged. In conclusion, YCP can be potentially be used as an alternative functional ingredient for partial replacement of wheat flour in formulating biscuit and muffin because of its ability to improve the nutritional quality without jeopardizing sensorial palatability.
This paper presents the study of mechanical properties of short random oil palm fibre reinforced epoxy (OPF/epoxy) composites. Empty fruit bunch (EFB) was selected as the fibre and epoxy as the matrix. Composite plate with four different volume fractions of oil palm fibre was fabricated, (5 vol%, 10 vol%, 15 vol% and 20 vol%). The fabrication was made by hand-lay up techniques. The tensile and flexural properties showed a decreasing trend as the fibre loading was increased. The highest tensile properties was obtained for the composite with fibre loading of 5 vol% and there were no significant effect for addition of more than 5 vol% to the flexural properties. Interaction between fibre and matrix was observed from the scanning electron microscope (SEM) micrograph.
Effects of aluminium hydroxide (ATH) addition on the properties of palm-based polyurethane composites were investigated. The hybrid composites were prepared by mixing 10 wt% of oil palm empty fruit bunch fiber (EFB) with ATH at varying amount of 2, 4 and 6 wt% of the overall mass of the resin. The compression stress and modulus gave the highest values of 575 and 2301 kPa, respectively at 2 wt% loading of ATH. The compression stress and modulus decreased drastically at 4 wt% (431 kPa and 1659 kPa, respectively) and further decreased at 6 wt% ATH (339 and 1468 kPa, respectively). However, the burning rate is inversely proportional to the loading percentage where the highest burning rate was observed at 2 wt% ATH. Sound absorption analysis indicated a large absorption coefficient at high frequency (4000 Hz) for all samples. The highest absorption coefficient was obtained from PU-EFB/ATH with 4 wt% ATH.
Electrospinning is a promising approach to fabricate desirable electropsun nanofibrous scaffold that could be applied in the medical fields. In this study, bacterial copolymer poly(3-hydroxybutyrate-co-68 mol% 4-hydroxybutyrate) [P(3HB-co-68mol% 4HB)] copolymer produced was fabricated into electrospun nanofibers using various combination of electrospinning parameters including the polymer solution, applied voltage and injection speed. The morphology of the fabricated scaffolds were observed using scanning electron microscope (SEM). The SEM images were analysed for the fibre diameter distribution of the scaffolds using Image Analyser. The results revealed that the 8 wt% of polymer solution, 25 kV/cm of the applied voltage and 1.5 mL/h of the injection speed was the most suitable combination. This electrospinning parameters combination fabricated nanofibrous P(3HB-co-4HB) scaffold with smooth, beadles and uniform nanofibers with small fibre diameter distribution.
The mechanics of damage and fracture process in unidirectional carbon fiber reinforced polymer (CFRP) composites subjected to shear loading (Mode II) were examined using the experimental method of the three-point end-notch flexure (3ENF) test. The CFRP composite consists of [0o]16 with an insert film in the middle plane for a starter defect. A 3ENF test sample with a span of 50 mm and interface delamination crack length of 12.5 mm was tested to yield the load vs. deformation response. A sudden load drop observed at maximum force value indicates the onset of delamination crack propagation. The results are used to extract the energy release rate, GIIC, of the laminates with an insert film starter defect. The effect of the starter defect on the magnitude of GIIC was examined using the CFRP composite sample with a Mode II delamination pre-crack. The higher magnitude of GIIC for the sample with insert film starter defect was attributed to the initial straight geometry of the notch/interface crack and the toughness of the resin at the notch front of the fabricated film insert. The fractured sample was examined using a micro-computerized tomography scanner to establish the shape of the internal delamination crack front. Results revealed that the interface delamination propagated in a non-uniform manner, leaving a curved-shaped crack profile.
This study aims to investigate the void content, tensile, vibration and acoustic properties of kenaf/bamboo fiber reinforced epoxy hybrid composites. The composites were made using the hand lay-up method. The weight ratios of kenaf/bamboo were 30:70, 50:50 and 70:30. Further, kenaf and bamboo composites were fabricated for the purpose of comparison. The hybridization of woven kenaf/bamboo reduced the void content. The void contents of hybrid composites were almost similar. An enhancement in elongation at break, tensile strength and modulus of hybrid composites was observed until a kenaf/bamboo ratio of 50:50. Kenaf/bamboo (50:50) hybrid composite displays the highest elongation at break, tensile strength and modulus compared to the other hybrid composites which are 2.42 mm, 55.18 MPa and 5.15 GPa, respectively. On the other hand, the highest natural frequency and damping factors were observed for Bamboo/Kenaf (30:70) hybrid composites. The sound absorption coefficient of composites were measured in two conditions: without air gap and with air gap (10, 20, 30 mm). The sound absorption coefficient for testing without air gap was less than 0.5. Introducing an air gap improved the sound absorption coefficient of all composites. Hence, hybrid kenaf/bamboo composites exhibited less void content, as well as improved tensile, vibration and acoustic properties.
Oil is one of the major components of date seed alongside dietary fibre, carbohydrate, protein, moisture and ash. Therefore, the present work focused on the extraction of oil from five varieties of date seed using Soxhlet extraction method and subsequently characterised their physicochemical and antioxidant properties accordingly. Oil extracted from the seeds ranged between 8 to 9.8%, whereas the iodine values were between 48.7 to 55.5 g I2/100g. Furthermore, oleic and lauric acids were revealed as the main fatty acids present in the date seed oil, with LaOO (La: lauric acid; O: oleic acid) as the main triacylglycerol. The total phenolic content in the oil ranged from 7.96 to 17.72 mg GAE/g oil, while the antioxidant activity, expressed as EC50, ranged from 5.17 to 17.18 mg/mL. Additionally, the highest reducing activity was observed at 4mg/mL. Hence, oil characteristics are dependent on the type of date, thus indicating that different potential applications may be suggested.
Acetoin is used in the biochemical, chemical and pharmaceutical industries. Several effective methods for acetoin production from petroleum-based substrates have been developed, but they all have an environmental impact and do not meet sustainability criteria. Here we describe a simple and efficient method for acetoin production from oil palm mesocarp fiber hydrolysate using engineered Escherichia coli. An optimization of culture conditions for acetoin production was carried out using reagent-grade chemicals. The final concentration reached 29.9gL(-1) with a theoretical yield of 79%. The optimal pretreatment conditions for preparing hydrolysate with higher sugar yields were then determined. When acetoin was produced using hydrolysate fortified with yeast extract, the theoretical yield reached 97% with an acetoin concentration of 15.5gL(-1). The acetoin productivity was 10-fold higher than that obtained using reagent-grade sugars. This approach makes use of a compromise strategy for effective utilization of oil palm biomass towards industrial application.
The paper reveals the design of a unit cell of a metamaterial that shows more than 2 GHz wideband near zero refractive index (NZRI) property in the C-band region of microwave spectra. The two arms of the unit cell were splitted in such a way that forms a near-pi-shape structure on epoxy resin fiber (FR-4) substrate material. The reflection and transmission characteristics of the unit cell were achieved by utilizing finite integration technique based simulation software. Measured results were presented, which complied well with simulated results. The unit cell was then applied to build a single layer rectangular-shaped cloak that operates in the C-band region where a metal cylinder was perfectly hidden electromagnetically by reducing the scattering width below zero. Moreover, the unit cell shows NZRI property there. The experimental result for the cloak operation was presented in terms of S-parameters as well. In addition, the same metamaterial shell was also adopted for designing an eye-shaped and triangular-shaped cloak structure to cloak the same object, and cloaking operation is achieved in the C-band, as well with slightly better cloaking performance. The novel design, NZRI property, and single layer C-band cloaking operation has made the design a promising one in the electromagnetic paradigm.
The present study was conducted to investigate the effects of brown rice (BR) powder addition on the proximate composition, total dietary fibre content and acceptability of some selected Malaysian traditional rice-based local kuih. Two types of kuih samples, namely Kuih Lompang (KL) and Kuih Talam Pandan (KTP) were prepared at the levels of either 0%, 10%, 20% or 30%. The kuih samples were analyzed for nutritional composition and sensory acceptance. There was significant increase in total dietary fibre content (from 2.64 g/100 g to 3.15 g/100 g) and protein content (from 2.36% to 2.51%) with the incorporation of 90% BR powder in the KL formulation. The moisture (from 36.79% to 36.83%), ash (from 1.11% to 1.21%) and fat (from 8.51% to 8.73%) content were not significantly affected for all percentages of BR powder addition. For KTP, the addition of BR powder at the level of 90% significantly increased the total dietary fibre (from 2.77 g/100 g to 3.45 g/100 g), fat (from 5.73% to 6.95%) and moisture (from 64.10% to 64.12%) content as compared to the control (0%). However, the protein content was not significantly affected (from 3.41% to 3.59%). On the other hand, there was no significant difference for all sensory attributes of KL formulated with 30-90% of BR powder as compared to the control (0%). The sensory score of KTP added with 30-90% BR powder received significantly lower sensory score compared to the control sample (0%) for appearance, colour, firmness, adhesiveness, chewiness, taste and overall acceptance attributes. In summary, sensory evaluation showed that all BR-incorporated KL were acceptable, while only 30% addition of BR powder in KTP was acceptable. Thus, BR powder is potentially used in improving the nutritional composition of KL. However, further study is needed to improve palatability aspect of KTP formulated with BR powder.