Mohd Hanafi Ani

Comparative Electrochemical Performance Characteristics of Aluminium-Air Cell Employing Seawater and NaCl Electrolytes

The electrochemical performance of Al-air cell employing seawater and NaCl electrolyte of various concentrations has been investigated. The open circuit voltage and discharge capacity of the cell correlate well with the electrolyte conductivity data. Using 4 M NaCl electrolyte which possesses the highest conductivity, the Al-air cell registers an open circuit potential (OCV) of 1.1 V and demonstrates discharge capacity of 250 mAh, rated at 1 mA. Upon employing seawater, the OCV reduced to 0.68 V and discharge capacity decreased to 150 mAh. However, utilizing an exposed cell configuration which mitigates the hydroxide gel water binding effect, the Al-air seawater cell performance is greatly enhanced until almost compatible to Al-air cell employing 4 M NaCl.

Synthesis and Characterization of ZnO Thin Film Memristor

ZnO films were deposited on Cu substrate using electrodeposition and thermal oxidation method. The effect of deposited thin film thickness varied with deposition time was discussed. Synthesized ZnO films were characterized using XRD, FE-SEM and electrical measurement. The results from electrical measurement showed the deposited ZnO exhibits pinched hysteresis IV curves. The synthesized ZnO shows a potential applications and options in production of a non-complex and low cost memristor.

Carbon doped iron ore using palm kernel shell

This paper pertains to the reduction process of local low grade iron ore using palm kernel shell (PKS). It is well known that low grade iron ores contain high amount of gangue minerals and combined water. Biomass waste (aka agro-residues) from the palm oil industry is an attractive alternative fuel to replace coal as the source of energy in mineral processing, including for the treatment and processing of low grade iron ores. Both iron ore and PKS were mixed with minute addition of distilled water and then fabricated with average spherical diameter of 10-12mm. The green composite pellets were subjected to reduction test using an electric tube furnace. The rate of reduction increased as temperature increases up to 900 °C. The Fe content in the original ore increased almost 12% when 40 mass% of PKS was used. The reduction of 60:40 mass ratios of iron ore to PKS composite pellet produced almost 11.97 mass% of solid carbon which was dispersed uniformly on the surface of iron oxide. The aim of this work is to study carbon deposition of PKS in iron ore through reduction process. Utilization of carbon deposited in low grade iron ore is an interesting method for iron making process as this solid carbon can act as energy source in the reduction process.

Fabrication of Flexible Au/ZnO/ITO/PET Memristor Using Dilute Electrodeposition Method

DRAM has been approaching its maximum physical limit due to the demand of smaller size and higher capacity memory resistor. The researchers have discovered the abilities of a memristor, a Non Volatile Memory (NVM) that could overcome the size and capacity obstacles. This paper discussed about the deposition of zinc oxide (ZnO) on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrate by electrodeposition. Metallic Zn film was deposited on substrates with varying deposition time from 15 to 120 seconds in very dilute zinc chloride (ZnCl2) aqueous and subsequently oxidized at 150 °C to form ZnO/ITO coated PET junction. The deposited thin film was characterized via x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results from I-V measurement show the deposited ZnO exhibits pinched hysteresis loop. The hysteresis loop becomes smaller with increasing deposition time. The 15 seconds electrodeposition gave the largest hysteresis loop and largest value of resistive switching ratio of 1.067. The result of the synthesized ZnO on the flexible substrate can be one of the alternatives to replace the current memory system as the flexible memory system.

A critical review on the contributions of chemical and physical factors toward the nucleation and growth of large-area graphene

Abstract Since the first isolation of graphene over a decade ago, research into graphene has exponentially increased due to its excellent electrical, optical, mechanical and chemical properties. Graphene has been shown to enhance the performance of various electronic devices. In addition, graphene can be simply produced through chemical vapor deposition (CVD). Although the synthesis of graphene has been widely researched, especially for CVD growth method, the lack of understanding on various synthetic parameters still limits the fabrication of large-area and defect-free graphene films. This report critically reviews various parameters affecting the quality of CVD-grown graphene to understand the relationship between these parameters and the choice of metal substrates and to provide a point of reference for future studies of large-area, CVD-grown graphene.

Gold-Catalyzed growth of aluminium-doped zinc oxide nanorods by sputtering method

Aluminium-doped zinc oxide (AZO) nanorods thin films were grown by RF magnetron sputtering on gold (Au) metal catalyst. The Au catalyst layers with 5, 10, and 15 nm thickness were deposited on glass substrates by sputtering method followed by annealing for 15 min at 500°C to form Au nanostructures on the glass substrate. The AZO thin films were then deposited on the Au catalyst at different deposition temperature varying from 200 to 500°C. Postdeposition annealing processes of the Au catalyst resulted in different morphologies of the Au catalyst layers depending on their thicknesses. This in turn gave different AZO morphologies which suggest that the Au catalyst layer thickness and the deposition temperature contribute to the growth mechanism of the AZO nanostructures. AZO nanorods thin films having hexagonal wurtzite structure with individual nanorods on the film surface were obtained from the samples deposited on 5 and 10 nm thick Au catalyst with the deposition temperature of 300°C.

Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873–1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

Fabrication of Hip and Pelvis Part for Designing Acetabular Implant by Using Fused Deposition Modeling (FDM) Machine

The purpose of this research is to fabricate the hip and pelvis part for designing the acetabular implant by using Fused Deposition Modeling (FDM) technique. The methodology of this research is begin by converting the 2D image of CT into 3D image through Invesalius 3.0 software. Then the 3D image is converted to .stl format and exported to FDM machine for fabrication purpose. The finish prototype of 3D biomodel replica is evaluated in order to define the problem face by the patient. Also, the dimensional accuracy is measured between 3D replica model and 3D virtual model. Based on the result of 3D biomodel, the ball joint of the femur on the right side is dislocating from its original position because of the fracture occur on acetabular socket. The implant for acetabular fracture is design by using CATIA software and the design must ensure to be fit with the fracture area. Therefore, this study has contributed to medical area especially in Malaysia in improving patient specific preoperative planning and giving better visualization information of the fracture.

Electrical Properties Dependence on Substrate Temperature of Sputtered ZnO Nanoparticles Thin Films on Teflon Substrates

Zinc oxide (ZnO) thin films were deposited on teflon substrates by RF magnetron sputtering at different substrate temperature. The effect of substrate temperature on ZnO thin films electrical and structural properties were examined using current-voltage (I-V) measurement, and x-ray diffraction (XRD) It was found that the electrical conductivity and resistivity of the ZnO thin film deposited at 40°C was the highest and lowest intensity accordingly. This was supported by the crystalline quality of the films from the x-ray diffraction (XRD) results. The XRD pattern showed that the ZnO thin film deposited at 40°C has the highest intensity with the narrowest full-width-at-half-maximum indicating that the film has the highest quality compared to other thin film.

Object distance and size measurement using stereo vision system

Object size identification is very useful in building systems or applications especially in autonomous system navigation. Many recent works have started to use multiple vision sensors or cameras for different type of application such as 3D image constructions, occlusion detection and etc. Multiple cameras system has becoming more popular since cameras are now very cheap and easy to deploy and utilize. The proposed measurement system consists of object detection on the stereo images and blob extraction and distance and size calculation and object identification. The system also employs a fast algorithm so that the measurement can be done in real-time. The object measurement using stereo camera is better than object detection using a single camera that was proposed in many previous research works. It is much easier to calibrate and can produce a more accurate results.