International Journal of Nanoelectronics and Materials (IJNeaM)
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IJNeaM aims to publish original work of importance in the fields of nanoscience and engineering. Topics covered including Theoretical, Simulation, Synthesis, Design and Fabrication of Nanomaterials and Nanodevices; Metals, Insulators, and Semiconductors with a focus on Electronic, Structural, Magnetic, Optical, Thermal, Transport, Mechanical and other properties for the specialists in Engineering, Chemistry, Physics and Materials Science. IJNeaM accepts submission in the form of Reviews, Research Articles, Short Communications, and selected conference papers.
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PublicationSynthesis of chicken eggshell based nanofluorapatite using sonochemical and microwave-assisted precipitation methods(Universiti Malaysia Perlis (UniMAP), 2020-07)Fluorapatite (Ca10(PO4)6F2) is a fluorinated calcium phosphate that has high chemical and structural stability. Therefore, it is suitable to cover the outer layer of teeth. A variety of methods and synthetic chemicals have been used to produce fluorapatite. This paper reports the synthesis of nanofluorapatite using sonochemical and precipitation methods with chicken eggshells were used as the natural sources of calcium. The synthesis was also assisted by microwave irradiation, after precipitation processes, to be more efficient and faster. The irradiation was applied at a microwave power of 200 W and 400 W for 30 minutes and 45 minutes, respectively. The effect of ultrasonication amplitude was also observed in this experiment. Two different amplitudes applied are 20% and 40% of the maximum. The results reveal that accurate composition of CaO, H3PO4, and NH4F are needed to obtain pure chicken eggshell based fluorapatite as presented by X-ray diffractometer. This result is supported by Fourier Transform Infrared Spectrophotometer (FTIR) showing the presence of fluorapatite functional groups. Scanning Electron Microscope (SEM) with Energy-dispersive X-ray (EDX) spectroscopy was used to evaluate the surface morphology of the samples and the elements present near the surface. The scanning spectroscopy shows that the samples contained the elements of fluorapatite which are C, Ca, O, P and F. It was also presented by the microscope that the average particle sizes at a point were in the range of 68-117 nm, polygonal in shape and agglomerates.
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PublicationWideband non-linear vibration piezoelectric energy harvesting using a piecewise-linear mechanism(Universiti Malaysia Perlis (UniMAP), 2020-07)In recent years, energy harvesting technology has been given a lot of attention due to its capability to produce clean and sustainable energy to power electronic devices. The applications of this technology involve the area of biomedical, automotive, industrial, and even military applications. Currently, the energy harvesting device is made for more than one purpose. Due to similar operating characteristics, apart from tapping the ambient energy, it is also used as the dynamic vibration absorber (DVA). However, the conventional linear mechanism adopted in the system is limited to only in a restricted bandwidth. This paper proposes a newly designed non-linear piezoelectric energy harvesting device which was also adopted as a non-linear DVA (NDVA) by using a piecewise-linear stiffness mechanism. The mechanism consists of a cantilever beam constrained by two limit stoppers, which are adjustable in both horizontal and vertical directions. The restoring force-deflection behaviour for different limit block configurations was characterised using quasi-static measurement. The dynamic study was conducted for different limit block configurations and input amplitudes. The study on the dynamic behaviour shows that the device can widen the harvesting frequency bandwidth compared to its equivalent linear DVA.
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PublicationComparative study of transverse vibration and mechanical properties of aluminium, Al 7020 alloy, and MWCNTs reinforced aluminium nanocomposites(Universiti Malaysia Perlis (UniMAP), 2020-07)Alloys that mostly composed of aluminium are widely used in structural engineering especially in the aircraft industry. However, cyclic vibration may generate microcracks which lead to failure. Mechanical vibration is one of the most popular issues in any working machine. Besides, the vibration energy may transfer to the other portion of the structure as any mechanical waves causing noises, loose parts, heat, and wear. Structure damping and vibration isolation are the main two solutions to solve this problem. Metals behave like viscoelastic materials that made them a candidate to serve as dampers. Therefore, this paper investigates the transverse vibration and mechanical properties of aluminium, Al7020 alloy (Al-Zn-Mg alloy) and aluminum-multi-walled carbon nanotubes (Al-MWCNTs) nanocomposites. The samples were prepared using an open mould casting approach with flex. Experimental comparative study of dynamic behaviour and mechanical characteristics for the prepared samples were investigated. Transverse vibration test at different frequencies (motor rotating speed 0-3000 rpm) with and without loading, tensile test, flexural bending, and Vickers hardness tests were determined. Surface morphology and chemical analysis of as a cast prepared samples were characterized utilizing scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and optical microscope. The obtained results revealed different dynamic behaviour and mechanical properties of prepared samples due to the different microstructure effect generating from the addition of materials (alloying element and reinforcing materials). Al7020 alloy showed the highest ultimate tensile strength, axial stiffness, flexural strength, bending modulus, fracture toughness, and hardness compared with the other samples. Al-MWCNTs nanocomposites revealed minimum ultimate tensile strength, axial stiffness, and elongation % at the break, bending modulus, fracture toughness and maximum deflection. Moreover, the dynamic behaviour of all samples is dissimilar under transverse vibration test when applied load and frequency were changed. The Al-MWCNTs nanocomposites exhibited the most stable structure under transverse vibration test at maximum applied load and higher frequencies
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PublicationAluminium doping for enhancing charge photoanode ZnO nanorod for DSSC(Universiti Malaysia Perlis (UniMAP), 2020-07)Renewable energy sources have been developed as alternatives to fossil energy by several sources, such as solar energy and wind power. The progress on solar power conversion to electricity via solar cell is impressively developed to obtain the best performance and low-cost production. This paper studied the dye-sensitized solar cell (DSSC) as it is cost-effective and environmentally friendly compared to the widely used silicon-based cells. However, the low current density and power conversion efficiency are the primary limitations of DSSCs, especially zinc oxide (ZnO)-based DSSCs. In this study, the ZnO nanorod properties are enhanced through aluminium (Al) doping. To find the optimum doping concentration, the concentration of Al was varied at 0%, 0.5%, 1.0%, 1.5%, and 2.0%. Al-doped ZnO nanorods were grown by a seed-mediated hydrothermal method at 90℃ for 8 hours. The morphological, structural, optical, and photovoltaic properties of these nanorods were analysed by field emission scanning electron microscopy, X-ray diffraction, UV-Vis spectroscopy, and J-V curve analysis. ZnO nanorods with 1.0% Al doping demonstrate photovoltaic performance improvement up to 241.8%.
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PublicationA comparative study of the electrical characteristics of generating argon plasma in different inter-electrode spacing discharges(Universiti Malaysia Perlis (UniMAP), 2020-07)This work aims to study the effect of different inter-electrode spacing of the DC system on the generated plasma and the electrical characteristics (I-V discharge voltage). The study uses Paschen gas pressure (I-P) curves for glass samples by niobium. The plasma is produced when the argon gas flows into the chamber at 0.08 mbar and the injected voltage of 700 V. The Paschen curve is considered for distances (2, 4, 6, 8 cm) by measuring the collapse voltage and current-voltage (I-V). From the curve flow, I-P increased due to the increment of discharge current. The best discharge current value is 40 mA while the distance is 4 cm. The results reveal that the inter-electrode spacing influences the values of the electrical characteristics of the generated plasma. The proportion of discharge voltage to discharge current is direct and nonlinear. In addition, the findings indicate that the best distance is 4 cm.