Now showing 1 - 3 of 3
  • Publication
    Lumped-element circuit modeling for composite scaffold with nano-hydroxyapatite and wangi rice starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
  • Publication
    Lumped-element circuit modeling for composite scaffold with Nano-Hydroxyapatite and wangi rice starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
  • Publication
    Effect of pineapple leaf (PALF), napier, and hemp fibres as filler on the scratch resistance of epoxy composites
    This article presents the effects of pineapple leaf (PALF), napier, and hemp fibres as filler on the scratch resistance of epoxy composites. In particular, it explores the effect of these natural fillers on the horizontal load, coefficient of friction (COF), penetration depth, fracture toughness, scratch hardness, brittleness index and scratch observation. The mixing method using magnetic stirrer was used to produce the natural fibre-filled epoxy composites with different wt%, namely, 5, 7.5, and 10 wt%. The test was performed using a CSM Revetest Xpress, which consisted of a cone of the half-apex angle of 60° ending with a sphere having a tip radius of 200 μm. The indenter scratch distance and speed were 7 mm and 1.5 mm/min, respectively. The results show that the napier fibre-filled epoxy composites have the highest peak load and COF. It was also noted that the napier fibre-filled epoxy composites have the lowest penetration depth for each wt% of filler. Lastly, the fracture toughness (Kc) for the napier fibre-filled epoxy composites with 10 wt% of filler yielded the highest value of 4.33 MPa.m1/2. It can also be seen that using a scanning electron microscope (SEM), the amount of debris increased with higher of wt% of the natural fibre fillers in the composites. Hence it was demonstrated that the napier fibre-filled epoxy composites have higher scratch resistance compared to the PALF and hemp fibre-filled epoxy composites. Keywords: Surface analysis, Fracture toughness, Scratch resistance, PALF, Napier, Hemp fibres.
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