Hariati Taib

Effect of zeta potential of stanum oxide (SnO2) on electrophoretic deposition (EPD) on porous alumina

Zeta potential analysis of stanum oxide (SnO2) aqueous suspensions (pH7 to pH11) was performed prior to the electrophoretic deposition (EPD) of SnO2. Deposition of SnO2 on porous alumina was obtained by applying the EPD technique carried out by applying voltage of 18V for duration of four minutes. It was found that the depositions SnO2 suspended at pH 7 to pH 11 were successful. The relation between the SnO2 deposition with SnO2 pH and zeta potential values was established in which increased value of pH causes decreased value of zeta potential and decreased SnO2 deposition through EPD technique.

Short Review: Ceramic Foam Fabrication Techniques for Wastewater Treatment Application

Ceramic foam is a class of highly porous materials that are used for wide range of technological applications, specifically as absorbents and membrane for wastewater treatment process. Among the potential materials include silicon carbide (SiC), alumina (Al2O3), zirconia (ZrO2), titania (TiO2), and silica (SiO2). The review clarifies on the broad types of ceramic foam, and the common techniques of foam fabrication, such as polymeric sponge method, starch consolidation, direct foaming, and gel-casting of foam. The parameters of each fabrication techniques will be discussed crucial based on the new research findings in the field of ceramic foam.

Potassium Bromide as Space Holder for Titanium Foam Preparation

Titanium (Ti) alloy foam was prepared by using potassium bromide (KBr) as space holder with percentage between 20 to 40 wt.%. In this work, the potential of KBr as a new space holder was determined. The Ti alloy powder and space holder were first manually mixed before being compacted using hydraulic hand press. The green compacts were then sintered at temperature of 1160°C, 1200°C and 1240°C in a tube furnace. The microstructure of the Ti alloy foams were observed by Scanning Electron Microscope (SEM). It was revealed that the porosity content in the Ti foam was in the range of 16% to 31% and density in the range of 1.5 g/cm3 to 2.6 g/cm3. Moreover, the pore size of the titanium alloy foam is in the range of 187μm to 303μm. Although the sintering temperatures were found incapable of promoting overall densification to the Ti alloy foam, 1200°C was denoted to be the maximal temperature for promoting maximal porosity to the Ti alloy foam. Nonetheless, KBr was proven to be suitable as space holder for Ti foam preparation as referred to its stability and insolubility in the Ti alloy.

Assessment and Evaluation for Programme Learning Outcomes in Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia

Universiti Tun Hussein Onn Malaysia (UTHM) is the 15th of the 20 public universities established in Malaysia. UTHM consists of eight faculties. One of them is the Faculty of Mechanical and Manufacturing Engineering (FKMP). The programme offered – Bachelor of Mechanical Engineering with Honours (BDD), undergoes continuous auditing and accreditation by the Engineering Accreditation Council (EAC). To fulfill the requirement for accreditation, EAC requires the faculty to assess and evaluate the programme learning outcomes’ (PLOs) attainment of the graduates, such that all graduates are targeted to achieve the performance indicator (PI) upon graduation. This paper discusses the methods developed by the FKMP for PLOs’ measurement and evaluation. Two approaches are utilized in this regards, (i) the direct assessment based on students’ performance in courses, and (ii) the indirect assessment based the industrial and graduates’ perception. The PLOs’ attainment for graduates of cohort 2010-2012 are analysed in this study. Consolidation data shows that the PI for majority of the PLOs are achieved, indicating that the programme offered complies with the standard expected by different stakeholders.

Programme Learning Outcomes Assessment and Continuous Quality Improvement in Faculty of Mechanical and Manufacturing, UTHM

This paper describes the assessment and continuous quality improvement of Programme Learning Outcomes (PLOs) in the Faculty of Mechanical Engineering and Manufacturing. PLO is known as an elementary requirement in Outcome Based Education (OBE) system. All PLOs have been mapped with graduate attributes by EAC Manual 2012. Conceptual process for establishing and reviewing PLOs has been explained in the Plan-Check-Do-Act cycle. PLO assessment has been shown in different types which classified as direct and indirect methods. Continuous Quality Improvement has been extracted from a variety of assessment and has been discussed. Seven (7) CQIs are identified using different assessment methods of PLO during years 2013 to 2016 and subsequent improvement actions have been taken by the faculty within three years.

Characterisation of silica derived from rice husk (Muar, Johor, Malaysia) decomposition at different temperatures

Rice husk was thermally decomposed to yield powder composed of silica (SiO2). Temperatures of 700°C and 1000°C were chosen as the decomposition temperatures. X-Ray Diffraction (XRD), X-Ray Florescence (XRF), Fourier Transform Infrared (FTIR), and Field Emission Scanning Electron Microscope (FESEM) analyses were conducted on a synthetic silica powder (SS-SiO2) and the rice husk ash as for the comparative characterisation study. XRD analyses clearly indicated that the decomposed rice husk yielded silica of different nature which are Crystalline Rice Husk Silica (C-RHSiO2) and Amorphous Rice Husk Silica (A-RHSiO2). Moreover, it was found that SS-SiO2 was of Quartz phase, C-RHSiO2 was of Trydimite and Cristobalite. Through XRF detection, the highest SiO2 purity was detected in SS-SiO2 followed by C-RHSiO2 and A-RHSiO2 with purity percentages of 99.60%, 82.30% and 86.30% respectively. FTIR results clearly indicated silica (SiO2) bonding 1056, 1064, 1047, 777, 790 and 798 cm−1) increased as the crystallinity silica increased. The Cristobalite phase was detected in C-RH SiO2 at the wavelength of 620 cm−1. Morphological features as observed by FESEM analyses confirmed that, SS-SiO2 and C-RH SiO2 showed prominent coarse granular morphology.

The effects of composition and sintering temperature on the silica foam fabricated by slurry method

Reticulated ceramic or open pore ceramic foam is a well-known material which exhibits extremely high porosities, with a significant degree of interconnectivity that makes them desirable in a wide range of applications. There were broad types of ceramic foam fabrication method such as polymeric sponge method, direct foaming, and starch consolidation. In this study, the slurry method has been chosen to fabricate Silica (SiO2) foam. In this process, Polyurethane (PU) foam template was dipped into ceramic slurry and followed by drying and sintering to obtain foam which contains porosity in the range of 50% to 70%. The compositions of SiO2 were varied starting from 55 wt.%, 60 wt.%, 65 wt.% and 70 wt.%. The samples of SiO2 that have been dipped and dried were sintered at 900°C, 1000°C, 1100°C, and 1250°C. The sintered SiO2 ceramic foam samples were characterized to observe their morphology, and physical properties. Thus, the microstructure of the SiO2 ceramic foams samples was examined by Scanning Electron Microscopy (SEM), and Electron Dispersive Spectroscopy (EDS). Meanwhile, the physical properties of the SiO2 ceramic foam samples such as the total porosity (%) and bulk density were determined using Archimedes method. It was found that the density of ceramic foam produced was in the range of 0.25 g/cm3 up to 0.75 g/cm3, whereas the level of porosity percentage was in the range of 61.81% to 82.18% with the size of open pore or window cells were in between 141 µm up to 626 µm.

Effect of Silicon Oxide Size and Reducing Environment on the Photocatalytic Capability of Poly(Vinyl Alcohol)/Chitosan/Silicon Oxide Beads

The present work assess the capability of silicon oxide (SiO2) nanoparticle and microparticle incorporated in poly (vinyl alcohol)/chitosan/silicon oxide (PVA/CS/SiO2) beads to reduce chromium (Cr) ions of Cr (VI) to Cr (III). PVA/CS/(nanoand micro)-SiO2 beads were prepared through a simple drop wise method. The elemental analysis of prepared photocatalytic beads were confirmed by scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) and morphology of PVA/CS/SiO2 beads before and after Cr ions reduction were observed with SEM. The reduction of chromium (Cr (VI)) ions by both of PVA/CS/(nanoand micro)-SiO2) beads, as evaluated by the reduction duration taken were studied by photocatalytic process in which factors of SiO2 powders size and pH of reducing environment were varied. Photocatalytic studies revealed better performance of PVA/CS/nanoSiO2 beads in compared to PVA/CS/micro-SiO2 beads in Cr (VI) to Cr (III) ions reduction. Reduction Cr (VI) to Cr (III) ions by PVA/CS/nanoSiO2 beads occurred in 30 minutes and 50 minutes by PVA/CS/micro-SiO2. Moreover, both PVA/CS/(nanoand micro)-SiO2 showed excellent reduction of Cr (VI) ions at lower pH environment. It is thus concluded that both of PVA/CS/(nanoand micro)-SiO2 beads are capable for chromium reduction in highly acidic environment in which PVA/CS/nanoSiO2 beads showed better performance.

Vibration Exposure Analysis of the Polysiloxane Reinforced with Rice Husk Silica

One of approaches to protect devices from unpleasant vibrating disturbances is by employing a vibration absorber. This paper explores the viability of polysiloxane as raw material, added with rice husk silica fillers to produce a vibration absorbent sheet. The polysiloxane reinforced with rice husk sheets were made using hot compression moulding technique. The samples were tested for its density and tensile tests according to related standards. As for vibration test, a portable hand grinder was used to estimate the vibration exposure experienced by the users. The polysiloxane sheets were strapped on the tool’s handle and the vibration exposure was measured. The result shows that by applying the polysiloxane sheets on the tool grinder reduces the vibration magnitude by a maximum value of 38 percents. The longest vibration time exposure was recorded for 6.42 hours, improved by 150 percents from the original vibration time exposure of 2.52 hours. The results also demonstrated that polysiloxane with 4 wt. % rice husk silica was the optimum combination for vibration application since it produced highest vibration magnitude reduction and longest vibration exposure time of grinder applications.

Characterisation of Hand-Cast Polysiloxane-Silica Sheet Composite

The study investigates the effects of various contents of rice husk silica (RHS) on mechanical properties of polysiloxane (POS) sheet composite. The polysiloxane sheet composites filled with 5wt%, 10wt%, 15wt% and 20wt% of RHS were fabricated using casting technique at room temperature. The polysiloxane sheet reinforced RHS (POS-RHS) composites were characterised using thermogravimetry analysis (TGA), Fourier Transformation Infrared Spectroscopy (FTIR) and tensile test to determine the thermal and mechanical properties. It was found that the RHS as filler in polysiloxane is improvement in mechanical properties and the curve degradation of POS and POS-RHS are similarly. By using FTIR was shown the affect of Si and O bonding from RHS as filler.