M. Zaki

Optimization of time on CF4/O2 etchant for inductive couple plasma reactive ion etching of TiO2 thin film

In this work, we investigate the optimum etching of titanium dioxide (TiO2) using inductive couple plasma reactive ion etching (ICP-RIE) on our fabricated devices. By using a combination of CF4/O2 gases as plasma etchant with ratio of 3:1, three samples of TiO2 thin film were etched with different time duration of 10 s, 15 s and 20 s. The ion bombardment of CF4 gases with plasma enhancement by O2 gas able to break the oxide bond of TiO2 and allow anisotropic etch profile with maximum etch rate of 18.6 nm/s. The sample was characterized by using optical profilometer to determine the depth of etched area and scanning electron microscopy (SEM) for etch profile characterization.

Characterization of Difference Size of IDE Pattern for Formaldehyde Detection Sensor

This paper studies the effect of different gap sizes of IDE pattern on the surface morphology and electrical properties for the formaldehyde detection sensor. Two types of IDE chrome mask are designed to determine the ideal IDE pattern for formaldehyde gas detection by using conventional lithography. In the first method, IDE is transferred onto SiO2 layer. In order to ensure that the perfect pattern with minimum defect structure is obtained, the process parameters should be optimized and controlled. In the second method, the aluminium is deposited directly on SiO2/Si substrate by using IDE hard mask design plate. The fabricated IDE pattern is further validated through morphological and electrical characterization. The average gap size of IDE sensor is approximately 100 μm and 400 μm for IDE chrome and IDE hard mask respectively. The latter method is preferable since for formaldehyde gas sensing large size is needed and moreover the process is simple and requires low cost. Characterization of difference IDE pattern is demonstrated by various measurements.

Analysis of Soil Nailing under Earthquake Loading in Malaysia Using Finite Element Method

Soil nailing has become a widely accepted method and offers a practical solution towards construction of permanent retaining wall, slope stabilization and protection of existing cuts from failure. In Malaysia, soil nailing is typically performed on cut slope and installed with grouting as preventatives method due to erosion problem. However, although the effectiveness of soil nailing system may be well understood by practitioners, the slope failure and collapses of deep excavation are continuously occurs, especially for the construction in the earthquake zone. Malaysia has numerous experiences of earthquake even this country has been categorized as low seismicity group. Hence, it is become important in the scope of geotechnical engineering to analyze and study the effect of earthquake to soil nailing systems in Malaysia. Aims of this paper are to focus and study this technical issue using the application of finite element program. This research study selects PGA of 0.08g based on the location of major population in Malaysia. Safety factor was calculated in this finite element program using phi-c reduction. Soil nailing relatively give satisfactory response under seismic, so pseudo-static method is applied for seismic loading study. Based on the static analysis results, the FOS for the deep excavation stabilized with soil nailing is 1.54. However, by considering the earthquake or seismic loading, the FOS reduces to 1.16 and the percentage of reduction is about 25%. Total displacement was observed slightly difference in soil nailing analysis during an earthquake and static analysis

Success Factor for Site Management in Industrialized Building System (IBS) Construction

The Industrialized Building System (IBS) is the modern method construction which enables on-site prefabricated or precast building components manufactured at factories for building materials and housing products. Site management in IBS construction is crucial when dealing with the material and equipment at the workplace which can help the planning process of the project. The objectives of this research study are to discover the reason for using IBS construction in view of site management, to investigate the factors to improve towards site management in IBS construction (management, workplace, work team, safety, and material and equipment), and to produce a recommendation to improve the factors towards site management for IBS construction. The collected data has been analysed by using the Statistical Package Social Science (SPSS) version 21. This quantitative method research has analysed with frequency distribution method from SPSS v21 software. All three objectives have been achieved by finding the most important factor to improve site management which is the management factor with the highest mean 5.82 followed by the work team factor with 5.70 mean. The material and equipment factor is the lowest mean from the analysis data with 5.56 and safety factor with 5.67 higher than the workplace factor which is 5.64 mean. Thus, it clearly shows that the management factor is the most influenced factor that needs to improve in site management. In future, this research is suggested by doing a factor analysis in order to get the accurate result for the most influenced factor to improve site management.

Fabrication and characterization of titanium dioxide through different depositions method for detection of formaldehyde gas

This paper was studies about the effect of difference fabrication of TiO2 nanoparticle sensor on surface morphological structure and electrical properties for detection of formaldehyde. Two type of deposition method are used to deposit TiO2 nanoparticle layer on IDE/Si/SiO2 substrate. The fabrication of IDE was done by using conventional photolithography process. In the second method, the solution TiO2 was directly deposited by using e-beam evaporator. The fabricated of sensor was further validated through characterization on morphological surface inspection and electrical properties of the device. The roughness of TiO2 film was demonstrated that the latter method is preferable due surface uniformity approximately 70 nm in grain size to provide resistance barrier to allow current flow when interface with the formaldehyde. The result was demonstrated by various measurement.

Characterization of difference carbon nanotubes (CNTs) as a sensing mechanism for development of formaldehyde gas detection sensor

This paper are focused to characterize the difference CNTs deposit on Titanium Oxide (TiO2) as metal sensing for formaldehyde molecule detection. The sensor was fabricated by using two types of CNTs which is Single wall carbon nanotube (SWCNT) and Multi wall carbon nanotube (MWCNT) for measuring the most suitable device for detecting the formaldehyde gas. Characterization of difference IDE pattern is demonstrated by various measurements.

Carbon footprint hotspots of prefabricated sandwich panels for hostel construction in Perlis

Sustainable design and construction have gained increasing research interest, and reduction of carbon from building construction has become the main focus of environmental strategies in Malaysia. This study uses life cycle assessment and life cycle inventory analysis frameworks to estimate the amount of carbon footprint expressed in carbon dioxide equivalent tons (CO2e) produced by manufacturing prefabricated Industrialized Building System sandwich panels and its installation for a five-story hostel in Perlis, Malaysia. Results show that the carbon footprint hotspots were centered on boiler machine operation and cement with 4.52 and 369.04 tons CO2e, respectively. This finding is due to the extensive energy used for steam heating and high engine rating for the boiler. However, for cement, the carbon footprint hotspots are caused by the large quantity of cement applied in shotcrete mixture and its high extraction and production CO2 emission values. The overall onsite materials generated 96.36% of the total...

Potential of soil liquefaction at Perlis, northern region of Malalysia

Soil liquefaction is earthquake’s secondary effect which could cause fatal damages and structures instability. Despite Malaysia been located in stable zone of Pacific Ring of Fire, few significant surrounded quakes like Sumatra-Andaman earthquake had prompted Malaysian’s public concern, especially in Perlis area, on local seismic resistant. Hence, this research presents the analysis result of liquefaction potential of the soils, as the secondary effect of earthquake, within Perlis, northern region of Malaysia; the next strong and sustainable metropolis by using semi-empirical procedures introduced by Seed and Idriss. The study consists of two stages which were determination of the local geological and geotechnical site conditions within Perlis and analysis of soil liquefaction susceptibility by using various methods and liquefaction potential by using Simplified Procedure developed by Seed and Idriss on stress approach. There were consist of four phases implemented in order to achieve the objectives targe...

Development of gas sensing application for formaldehyde gas detection and characterization of tin dioxide

This paper presents the development of sensor in ultrasensitive detection of formaldehyde gas. The chemical compound, tin dioxide (SnO2) thin film is deposited onto glass insulator. Next, the resistance and voltage of the sensing layer on the interdigitated electrodes (IDE) sensor’s substrate is measured. The resistivity of sensor is changed by heat the sensing layer to 150 °C, 175 °C and 200 °C. When formaldehyde gas is supplied inside the test chamber, absorption process occurred at the surface of the heated SnO2 sensing layer. The experimental results show the sensor is capable of high sensitivity sensing of formaldehyde gas at 200 °C, repeatability, and capability detection as low as 11 ppm which produced 0.8 V on electronic reader. Characterization of surface morphological, temperature effect and electrical properties are demonstrated by various measurements.

Sensitivity and selectivity of metal oxides based sensor towards detection of formaldehyde

This paper presents the fabrication and characterization of metal oxides based sensor for detection of formaldehyde gas. Three different metal oxides are considered (i.e. TiO2, ZnO and SnO2) as transducer for the optimum sensitivity and selectivity detection. The metal oxides are deposited on the top on aluminum/glass substrate using sol-gel technique. Comparison performance has been made and found that SnO2 gives better sensitivity detection of formaldehyde molecule as compared with TiO2 and ZnO. At this stage, the test validation is done by dipping the electrode in 100 ppm formaldehyde liquid solution. Further, we show that SnO2 provides better selectivity toward the detection of formaldehyde and compared to acetone, ethanol, formaldehyde, isopropanol and methanol. Lastly, we demonstrate that, our sensor capable to detect down to 0.010 ppm of formaldehyde liquid. This excellent capability is achieved due to good uniformity and high surface-to-volume (approximately 70 nm) of SnO2 surface morphology characterized by using AFM.