Mohd Firdaus Omar
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Preferred name
Mohd Firdaus Omar
Official Name
Mohd Firdaus, Omar
Alternative Name
Omar, Mohd Firdaus
Mohd, Firdaus Omar
Omar, M. F.
Omar, Mohdfirdaus
Omar, Mohd F.
Main Affiliation
Scopus Author ID
36149536300
Researcher ID
U-8459-2019

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  • Publication
    Partially Replacement of Cement by Sawdust and Fly Ash in Lightweight Foam Concrete
    ( 2020-03-18)
    Mohd Firdaus Omar
    ;
    Muhd Afiq Hizami Abdullah
    ;
    Rashid N.A.
    ;
    Abdul Latif Abdul Rani
    The rapid growth of population has led to increased demand for fast, affordable and quality housing development. Today, the construction industry in Malaysia has shifted from conventional methods to Industrial Building Systems (IBS). The most commonly used IBS component is precasat concrete with lightweight foam concrete. This study focuses on the main component of foam lighweight concrete, which is a partially replacement of cement by sawdust and fly ash. Among the features of lightweight concrete is density below 1800 kg/m3. Therefore, the objectives of this study is to determine the effects of sawdust and fly ash as part of cement replacement in terms of mechanical properties (compressive strenght) and physical properties (water absorption). In addition, this study also determine the optimum percentage of cement replacement by sawdust and fly ash in building material. The percentage of saw dust and fly ash used in this study as a partial replacement cement are 5%, 10%, 15% and 20%. The results show that increasing the percentage of mix propotion will increase the water absorption rate as well as decrease the compressive strenght of strength. Also, the density and compressive strength of lightweight foam concrete will decrease as the percentage of partial replacement cement increases. According to JKR Standard Specification for Building Works that referred in Malaysia, the minimum compression strength of lightweight foam concrete allowed for hollow blocks is 2.8 N/mm2. The results obtained from this study show lightweight concrete blocks using saw dust and fly ash as part of the cement replacement meet the standards and can be commercialized in the industrial building system development.
  • Publication
    Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2020)
    Muhammad Razlan Zakaria
    ;
    Hazizan Md Akil
    ;
    Mohd Firdaus Omar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Aslina Anjang Ab Rahman
    ;
    Muhammad Bisyrul Hafi Othman
    The electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.
  • Publication
    Effect of Glass Reinforced Epoxy (GRE) pipe filled with geopolymer materials for piping application: compression properties
    ( 2016)
    Mohammad Firdaus Abu Hashim
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Che Mohd Ruzaidi Ghazali
    ;
    Kamarudin Hussin
    ;
    Mohammed Binhussain
    ;
    Mohd Firdaus Omar
    The aim of this paper is to achieve the highest compressive strength of glass reinforced epoxy pipe with the geopolymer filler content of weight percentage that were used in glass reinforced epoxy pipe. The samples were prepared by using the filament winding method. The effect of weight percentage of geopolymer materials in epoxy hardener was studied under mechanical testing, which is using the compression test. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 – 40 weight percentage geopolymer filler which is white clay were prepared. The compression strength of the glass reinforced epoxy pipe filled geopolymer materials is determined using Instron Universal Testing under compression mode. It was found that compressive strength for samples with white clay geopolymer filler are much higher compare to glass reinforced epoxy pipe without geopolymer filler. Moreover, the compressive strength of glass reinforced epoxy pipe filled with white clay geopolymer filler was increased from 10 wt% to 30 wt% of geopolymer content. However, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler suddenly decreased when added to 40 wt%. The results indicated that the blending of geopolymer materials in epoxy system can be obtained in this study.
  • Publication
    Enhancement of tensile properties of glass fibre epoxy laminated composites reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2021)
    Muhammad Razlan Zakaria
    ;
    Mohd Firdaus Omar
    ;
    Hazizan Md Akil
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Mohd. Mustafa Al Bakri Abdullah
    The introduction of carbon nanotubes (CNTs) onto glass fibre (GF) to create a hierarchical structure of epoxy laminated composites has attracted considerable interest due to their merits in improving performance and multifunctionality. Field emission scanning electron microscopy (FESEM) was used to analyze the woven hybrid GF-CNT. The results demonstrated that CNT was successfully deposited on the woven GF surface. Woven hybrid GF-CNT epoxy laminated composites were then prepared and compared with woven GF epoxy laminated composites in terms of their tensile properties. The results indicated that the tensile strength and tensile modulus of the woven hybrid GF-CNT epoxy laminated composites were improved by up to 9% and 8%, respectively compared to the woven hybrid GF epoxy laminated composites.
  • Publication
    Potential of soil stabilization using Ground Granulated Blast Furnace Slag (GGBFS) and fly ash via geopolymerization method: a review
    ( 2022)
    Syafiadi Rizki Abdila
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Romisuhani Ahmad
    ;
    Dumitru Doru Burduhos Nergis
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Firdaus Omar
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    Geopolymers, or also known as alkali-activated binders, have recently emerged as a viable alternative to conventional binders (cement) for soil stabilization. Geopolymers employ alkaline activation of industrial waste to create cementitious products inside treated soils, increasing the clayey soils’ mechanical and physical qualities. This paper aims to review the utilization of fly ash and ground granulated blast furnace slag (GGBFS)-based geopolymers for soil stabilization by enhancing strength. Previous research only used one type of precursor: fly ash or GGBFS, but the strength value obtained did not meet the ASTM D 4609 (<0.8 Mpa) standard required for soil-stabilizing criteria of road construction applications. This current research focused on the combination of two types of precursors, which are fly ash and GGBFS. The findings of an unconfined compressive strength (UCS) test on stabilized soil samples were discussed. Finally, the paper concludes that GGBFS and fly-ash-based geo-polymers for soil stabilization techniques can be successfully used as a binder for soil stabilization. However, additional research is required to meet the requirement of ASTM D 4609 standard in road construction applications, particularly in subgrade layers.
  • Publication
    The effect of twin screw compounding parameters on the tensile properties of pineapple leaf/sea shell hybrid polymer composite using DOE approach
    ( 2020-11-24)
    Ching N.T.
    ;
    Khairul Anwar Abdul Halim
    ;
    Mohd Firdaus Omar
    ;
    Azlin Fazlina Osman
    ;
    Muhammad Salihin Zakaria
    Pineapple leaf and sea shell were used as natural fillers in this research due to its biodegradable nature, wide availability, continuous resources and low cost. This research work was carried out to investigate the effect of compounding process using twin screw extruder on the tensile performance of pineapple leaf / sea shell polymer composite using Design of Experiment (DOE) approach. A total of nine runs of were formulated and the resulitng hybrid composites were compounded using twin screw extruder. The short term tensile test was carried out to determine the tensile properties and the data were sunsequently analyse using DOE software. Pareto chart of the standardized effect and the main effect plot were employed to investigate the relationship between processing parameters and the tensile performance of the hybrid composite systems. Based on the initial DOE analysis, it is shown that compounding parameters had influenced the final mechanical behavior of the hybrid composites.
  • Publication
    Nonisothermal kinetic degradation of Hybrid CNT/Alumina Epoxy Nanocomposites
    ( 2021)
    Muhammad Helmi Abdul Kudus
    ;
    Muhammad Razlan Zakaria
    ;
    Mohd Firdaus Omar
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Hazizan Md. Akil
    ;
    Marcin Nabiałek
    ;
    Bartłomiej Jeż
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Due to the synergistic effect that occurs between CNTs and alumina, CNT/alumina hybrid-filled epoxy nanocomposites show significant enhancements in tensile properties, flexural properties, and thermal conductivity. This study is an extension of previously reported investigations into CNT/alumina epoxy nanocomposites. A series of epoxy composites with different CNT/alumina loadings were investigated with regard to their thermal-degradation kinetics and lifetime prediction. The thermal-degradation parameters were acquired via thermogravimetric analysis (TGA) in a nitrogen atmosphere. The degradation activation energy was determined using the Flynn–Wall–Ozawa (F-W-O) method for the chosen apparent activation energy. The Ea showed significant differences at α > 0.6, which indicate the role played by the CNT/alumina hybrid filler loading in the degradation behavior. From the calculations, the lifetime prediction at 5% mass loss decreased with an increase in the temperature service of nitrogen. The increase in the CNT/alumina hybrid loading revealed its contribution towards thermal degradation and stability. On average, a higher Ea was attributed to greater loadings of the CNT/alumina hybrid in the composites.
      1  10
  • Publication
    Effect of Using Soap Nut as Natural Foaming Agent on Mechanical Properties and Pore Distribution of High Strength Aerated Concrete
    ( 2020-07-09)
    Muhd Afiq Hizami Abdullah
    ;
    Rashid N.A.
    ;
    Abdul Rani A.L.
    ;
    Mohd Firdaus Omar
    ;
    Tan Chan Sin
    Aerated concrete is a type of concrete that contains pore in its matrix structure. This pores could provide spaces for water absorption which makes aerated concrete more durable toward freeze-thaw cycle. Many methods have been studied in forming an aerated concrete and using soap nut as aerating agent is more sustainable than other chemically formulated agent. Forming of pore inside concrete not only improve freeze-thaw cycle durability but also as places to store healing agent in concrete. This is important in developing a self-healing concrete especially a microbial induced healing. This paper aims to study the effect of using soap nut in high strength concrete. Four types of high strength concrete samples were prepared which are Control sample, AE2 with 2% of aerated soap nut, AE4 with 4% of aerated soap nut and AE6 with 6% of aerated soap nut. Total of 3nos. of 100mm cubes and 3nos. of 50mm cubes from each type of samples were prepared. Cubes samples of 100mm dimension were tested for water absorption and compressive strength while cube samples of 50mm dimension were split and analysed for pore distribution. The results showed that increase in addition of soap nut in concrete mixture resulted in decrease of compressive strength but minimal effect on its water absorption rate. Pore formation and dispersion were optimum in concrete with 4% and 6% inclusion of soap nut. In conclusion, 4% of aerated soap nut in high strength concrete present the optimum characteristic in producing well-dispersed pores of high strength aerated concrete.
      2  20
  • Publication
    Gabor Filter and Moment Invariant via LDA Classifier for Skin Cancer Detection
    ( 2020-12-18)
    Mohd Firdaus Omar
    ;
    Muhammad Naufal Mansor
    ;
    Syahrul Affandi Saidi
    Skin cancer may be a serious tumor. This can be clearly seen through the mature, uncommon appearance of fur pathology, which has abnormal properties in complex situations, wrinkled or uncertain perimeters, and dual colors. A small number of tulle melanomas of uncertain diameter can imitate benign moles and cannot be perceived by optical inspection. The only assumption for analyzing them is through dermoscopy as an option. Original identification and medical surgery can alternative for the patients. Within this research a detection method through image processing with various feature extraction such as Gabor filter and Hu Moment were employed and substantially improves the diagnosis performance with 97% via LDA Classifier.
      3  4
  • Publication
    A Comparison Process Between Wet Lay-Up, Single Vacuum Bagging and Double Vacuum Bagging Toward Natural Fibre (Palm, Coconut and Kenaf) Reinforced Epoxy Composite Laminates
    ( 2023-06-01)
    Zakaria M.R.
    ;
    Ahmad Thirmizir M.Z.
    ;
    Zainol Abidin M.S.
    ;
    Md Akil H.
    ;
    Mohd Firdaus Omar
    ;
    Anjang Ab Rahman A.
    ;
    Nosbi N.
    ;
    Ab Ghafar N.
    The mechanical properties of palm, coconut, and kenaf fibre-reinforced epoxy composite laminates were evaluated using tensile (ASTM D3039) and flexural (ASTM D790) tests. The laminates were fabricated using different methods such as double vacuum bagging, single vacuum bagging, and wet lay-up. Results indicate that double vacuum bagging produced superior mechanical properties (up to 54.12% higher flexural modulus) compared to single vacuum bagging and wet lay-up methods. SEM images showed complete impregnation of fibres and a good interface between fibre and matrix in the composites produced via the double vacuum bagging method. This process creates a denser sample and allows the resin to penetrate the plies and core, eliminating voids in the laminate structure. Additionally, kenaf fibre-reinforced epoxy composite laminates exhibited higher mechanical properties (up to 104.82% higher tensile strength) compared to palm and coconut fibre-reinforced epoxy composite laminates.
      1  12