Syakirah Afiza Mohammed
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Preferred name
Syakirah Afiza Mohammed
Official Name
Syakirah Afiza, Mohammed
Alternative Name
Mohammed, S. A.
Mohammed, Syakirah Afiza
Main Affiliation
Scopus Author ID
56371130800
Researcher ID
FMO-2519-2022

Research Output

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Potential of pretreated palm kernel shell on pyrolysis

2023-01-01 , Razi Ahmad , Ragunathan Al Santiagoo , Abdul Ghapar Ahmad , Syakirah Afiza Mohammed , Wan Ahmad W.A.M. , Vikneswaran Vijean , Ibrahim N.R.

The impact of pretreatment on palm kernel shell (PKS) with torrefaction for the possibility of pyrolysis is discussed in this study. PKS samples were torrefied at different holding times of 30 and 60 minutes at temperatures of 200, 225, 250, 275, and 300 °C. In a fixed-bed reactor with a constant nitrogen flow rate of 500 ml/min, torrefaction pretreatment was carried out. The elemental composition, mass, and energy yield, as well as proximate analysis, were all performed on the pretreated PKS. The optimised pretreated PKS was pyrolyzed next at a temperature of 400 to 550 °C in a fixed-bed reactor. The outcomes demonstrated that the pretreated PKS had a significant mass and energy yield at a temperature of 250 °C and a holding time of 30 min. PKS's calorific value and carbon content both rose after pretreatment. However, the oxygen and moisture content decreased for pretreated PKS. The maximum bio-oil production of 58% was achieved during the pyrolysis of pretreated PKS at a temperature of 500 °C. At higher temperature of 550 ℃, the bio-oil decreased due to secondary cracking reaction. Consequently, the pretreated PKS has greater potential as effective feedstock for successive proses particularly pyrolysis for bio-oil production.

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Effect of bottom ash and limestone on the optimum binder content in Hot Mix Asphalt (HMA)

2022-01-01 , Nur Liza Rahim , Syakirah Afiza Mohammed , Noor Aina Misnon , Nurhidayah Hamzah , Roshazita Che Amat , Norlia Mohamad Ibrahim , Christina Remmy Entalai , Deák György

One of the most effective and simplest methods to minimize waste as well as reduce the environmental problems associated with waste disposal is by utilizing waste materials as a cement replacement in hot mix asphalt (HMA) mixtures which can provide the same or better stability as the conventional method. Fillers play an important role in the stability and strength of the pavement by filling voids between the aggregate particles in the performance of the HMA mixture. This research investigated the effect of the utilization of different types of filler (bottom ash and limestone) on the optimum binder content of HMA. Flow, stability, stiffness, air void in mix (VIM) and void filled with bitumen (VFB) were determined using the Marshal Method test in order to determine the optimum binder content of HMA for all mineral filler. The results of the Marshall test for each filler have been compared with the JKR standard specification. The optimum binder content for bottom ash, limestone and Ordinary Portland Cement (OPC) was 5.42%, 5.65% and 5.54%, respectively. All values of mineral filler used meet the JKR standard specification, where the range is between 4 and 6%. From the result achieved, the bottom ash has the lower optimum binder content value compared to the limestone and OPC. When the lower binder content is used in the bituminous mixture, the cost for pavement construction will be reduced.

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Publication

Effect of bottom Ash and limestone on the optimum binder content in Hot Mix Asphalt (HMA)

2022-01-01 , Nur Liza Rahim , Syakirah Afiza Mohammed , Misnon N.A. , Hamzah N. , Roshazita Che Amat , Norlia Mohamad Ibrahim , Entalai C.R. , Deák G.

One of the most effective and simplest methods to minimize waste as well as reduce the environmental problems associated with waste disposal is by utilizing waste materials as a cement replacement in hot mix asphalt (HMA) mixtures which can provide the same or better stability as the conventional method. Fillers play an important role in the stability and strength of the pavement by filling voids between the aggregate particles in the performance of the HMA mixture. This research investigated the effect of the utilization of different types of filler (bottom ash and limestone) on the optimum binder content of HMA. Flow, stability, stiffness, air void in mix (VIM) and void filled with bitumen (VFB) were determined using the Marshal Method test in order to determine the optimum binder content of HMA for all mineral filler. The results of the Marshall test for each filler have been compared with the JKR standard specification. The optimum binder content for bottom ash, limestone and Ordinary Portland Cement (OPC) was 5.42%, 5.65% and 5.54%, respectively. All values of mineral filler used meet the JKR standard specification, where the range is between 4 and 6%. From the result achieved, the bottom ash has the lower optimum binder content value compared to the limestone and OPC. When the lower binder content is used in the bituminous mixture, the cost for pavement construction will be reduced.

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Optimum Binder Content of Asphaltic Concrete (ACW14) Mixture Incorporating Limestone

2023-01-01 , Syakirah Afiza Mohammed , Abdul Ghapar Ahmad , Ragunathan Al Santiagoo , Vikneswaran Vijean , Wan Amiza Amneera Wan Ahmad , Razi Ahmad , Kai L.S.

Due to the high demand for natural aggregates in pavement construction, researchers have been looking for alternative materials to replace natural aggregate. In this research, the optimum binder content of asphalt mixture incorporate limestones was investigated. The optimum binder content of asphalt mixture was tested according to Marshall method. About 20 % of limestone was used as aggregate replacement in asphaltic concrete mixture. To determine the stability, volumetric properties, and bitumen binder content, three percentage of asphalt binder content, namely 4.0%, 5.0% and 6.0% was prepared. From analysis, it indicated that stability and volumetric properties of asphalt mixture incorporate limestone meet the requirement set by JKR. From the result obtained, the optimum binder content of the control sample is 5.0% and optimum binder content of limestone mixture is 5.2%. The slightly different in optimum binder content value indicate that the optimum binder content of limestone mixture was comparable with control mixture.

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Investigation on effect of gas concentration in distinguishing conventional plastic and bioplastic for plastic recycling

2022-12 , Ragunathan Al Santiagoo , Allan Melvin Andrew , Wan Amiza Amneera Wan Ahmad , Razi Ahmad , Syakirah Afiza Mohammed , Abdul Ghapar Ahmad , Vikneswaran Vijean , Mustaffa Zainal

Distinguishing type of plastic was important for the recycling process. In this project, the effect on gas concentration released from composite was studied to distinguish between conventional plastic and bioplastic. This project involved the fabrication of a composite from polypropylene (PP), empty fruit bunches (EFB), and recycle acrylonitrile butadiene rubber (NBRr), with PP used as a conventional plastic and PP/NBRr/EFB used as a bioplastic. Trans-polyctylene (TOR) was used as a compatibilizer to evaluate the effect on the PP/NBRr/EFB. Tensile testing and SEM were conducted to study the mechanical properties and morphological properties on the PP/NBRr/EFB and the PP/NBRr/EFB/TOR composite. The gas sensor (MQ135) was used in this study to detect the presence of NH3 and CO2 released from heating conventional plastic and bioplastic. From the overall result, composite with TOR as compatibilizer has shown better performance than composite without TOR in mechanical, morphological and gas sensor testing. By using MATLAB software, it shows that from gas sensor testing, it can be verified to distinguish between conventional plastic and bioplastics for plastic recycling. The average classification obtained from the Probabilistic Neural Network (PNN) was 99.29 % accurate.

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Investigation of bamboo as concrete reinforcement in the construction for low-cost housing industry

2020-06-10 , Rahim N.L. , Norlia Mohamad Ibrahim , Shamshinar Salehuddin , Syakirah Afiza Mohammed , Othman M.Z.

Concrete is the most consumed material, with three tonnes per year used for every person in the world. Twice as much concrete is used in construction as all other building materials combined. Concrete has excellent characteristic in compressive strength, but low in tensile strength. Steel commonly used in reinforcing material because of high tensile strength. The usage of steel as reinforcing material is limited because it is costly and also has an effect on air pollution during its manufacturing process. As an alternative to overcome this problem, bamboo material has been used as a replacement of reinforcement in concrete. Bamboo is a suitable material because it is a natural material, cheap and also available material. In this research, the performance of bamboos as an alternative material in reinforced concrete has been evaluated. Tensile strength test of bamboos has been performed to identify the yields stress of bamboos. From the test, result has shown that bamboo has a similar characteristic with steel and bamboo can be used as an alternative material for reinforcing concrete. However, the characteristic of bamboos showed high water absorption and low bonding strength between bamboo's surface and concrete. In this research, a waterproofing agent has been used to minimize water absorption and increase the bonding strength. Flexural strength test of the bamboo singly reinforced beam with the size of 150 mm x 150 mm x 750 mm has been undertaken to determine the performance of bamboo as reinforcement. From the test, it has resulted that bamboo give good potential as an alternative material in concrete reinforcement for low-cost housing industry.

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Preservation of natural resources by utilizing combustion ash in concrete and determination of its engineering properties

2023-01-01 , Norlia Mohamad Ibrahim , Nur Liza Rahim , Syakirah Afiza Mohammed , Roshazita Che Amat , Mustaqqim Abdul Rahim , Zailani W.W.A. , Laslo L. , Muhamad N.

Due to the large amount of combustion ash being thrown into landfills, which can lead to environmental pollution, new alternatives to construction materials can be developed by utilising this combustion ash as a part of the main raw materials, while at the same time helping to preserve natural resources in the concrete manufacturing industry. Generally, using new waste materials will eventually affect the engineering properties of concrete. Therefore, the main objective of this study is to analyse the engineering properties of concrete containing combustion ash as a partial replacement for ordinary Portland cement (OPC). CA can be classified as combustion bottom ash (CBA) and combustion fly ash (CFA). CA is tested for its chemical compositions using X-Ray Fluorescence (XRF), and its four main compositions, which are silica, alumina, iron, and calcium, are examined and discussed extensively. Other testing for the property of CA includes Scanning Electron Microscopic (SEM) and specific gravity testing for coarse aggregate. To produce sustainable concrete from waste, several tests have been conducted to determine the engineering properties of the concrete, such as compressive strength, flexural strength, and splitting tensile strength. Results show that CA, which consists mainly of silica dioxide, contributed to the strength of concrete. SEM images show that CBA has a porous structure with an angular and rough texture, whereas CFA has more rounded particles, which influence the overall compressive strength. Furthermore, it was discovered that as the proportion of CBA utilised increased, the compressive strength, flexural strength, and splitting tensile strength of the concrete improved. Based on the results of the testing, CBA is suggested for use as a supplementary cementitious material in concrete.

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Identification of habitual smokers through speech signal

2024-02-08 , Vikneswaran Vijean , Ragunathan Al Santiagoo , Abdul Ghapar Ahmad , Syakirah Afiza Mohammed , Razi Ahmad , Wan Amiza Amneera Wan Ahmad

Smoking is an addictive behavior and can result major health complications. Nowadays, many young adults tend to pick up this unhealthy habits which could potentially harm their health and affects the future workforce of the nation. Most of the habitual smokers have difficulties in ceasing this habit and require external assistance in the form of group therapy, medical interventions to quit smoking. Therefore, the main aim of this study is to investigate the speech signals of the subjects in an effort to identify the habitual smokers non-invasively. Through this detection, young smokers could be identified. Voice samples from VOice ICar fEDerico II from PhysioNet database were used for this study. Wavelet Packet Transform was used to extract non-linear features from the signals. Due to uneven data, ADASYN algorithm was used to produce a balanced dataset through synthetic data sampling. Subspace KNN and SVM classifiers were used for the investigations and classification accuracies up to 83.7% and 94% of AUC curve were observed from the analysis. The results suggests that the proposed method is effective in detecting habitual smokers, and can be considered as an early screening for smoking habits in young adults for targeted rehabilitation strategies.

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Investigation on Medicated Drugs in ECG of Healthy Subjects

2022-01-01 , Vikneswaran Vijean , Abdul Ghapar Ahmad , Syakirah Afiza Mohammed , Razi Ahmad , Wan Amiza Amneera Wan Ahmad , Ragunathan Al Santiagoo , Lim Chee Chin

Heart diseases are now the leading cause of death worldwide, it is estimated that around 7 million patients who are living in developed countries, lost their lives due to diseases related to their cardiovascular system. In Malaysia, cardiovascular diseases represents one fifth of total deaths in the country in the past three decades. Currently patients need some sort of drugs that help them to stabilize and restore the regular patterns of their heart beat because if the patients cannot manage to restore the normal heart beat pattern, the undesired heart condition could lead life threatening situations. Advancement of biotechnology has enabled the creation of new medicated drugs to provide better treatment options. However, when this treatment option fails and there is a need to provide emergency intervention to the patients in hospitals, the medical experts often need to know about the patients' intake of any medications prior to hospital admittance for providing suitable treatments. Sometimes, this would be a difficult task as the patient might be admitted in semi-conscious or unconscious state. Therefore, this study focusses on identification of different medicated drugs usage through analysis of ECG data of the users. The data for the experiment was obtained from physionet library, which provides ECG data of subjects administered with a combination of Dofetilide, Mexiletine, lidocaine, Moxifloxacin and Diltiazem medicated drugs. The use of morphological and non-linear features derived from the ECG signals were able to provide prediction accuracy of 77.26% using SVM classifier.

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Waste to concrete material: Potential Study of Chemical Characterization of Coal Fly Ash and Bottom Ash

2023-01-01 , Nur Liza Rahim , Syakirah Afiza Mohammed , Roshazita Che Amat , Norlia Mohamad Ibrahim , Hamzah N. , Samsudin S. , Shamshinar Salehuddin , Mustaqqim Abdul Rahim , Holban E.

This research focuses on the chemical properties of coal fly ash (CFA) and coal bottom ash (CBA) obtained from Sultan Azlan Shah Power Plant and compares them with the characteristics of ordinary Portland cement (OPC). Coal has been recognised as a significant fuel source in Malaysia, where it is extensively employed in the creation of steel, cement, and power. When coal is burned to create power, several different types of coal ash are created, including fly ash, bottom ash, boiler slag, and clinker. Fly and bottom ash, however, are the main coal ash waste products that have been created. In an effort to create sustainable concrete from waste, a number of studies have been carried out to ascertain the chemical characteristics of fly and bottom ash. These tests include Energy Disperse X-Ray (EDX), Mineralogy (XRD), and X-Ray Fluorescence (XRF). From the SEM result, fly ash has smaller particles and a spherical, uniform shape than bottom ash and cement. Fly and bottom ash from the Sultan Azlan Shah power plant contain a number of elements, including Silicon (Si), Aluminium (Al), Oxygen (O), Calcium (Ca), Titanium (Ti), Iron (Fe), Magnesium (Mg), Potassium (K), Carbon (C), and Sodium, according to Energy Dispersive X-Ray (EDX) test. The fly ash is primarily an amorphous material, with the presence of quartz crystalline phase (SiO2) at 24.3% and bottom ash at 31.1%, according to X-ray Diffraction (XRD) data. For the mullite phase (3AlO3.2SiO2), fly and bottom ash show results of 24.9% and 14.5%, respectively. According to an X-ray fluorescence (XRF) investigation, the main constituents of fly and bottom ash are silica, iron, and alumina. Fly ash is classified as Class F because it has a high concentration of SiO2, Al2O3, and Fe2O3 while OPC has a high CaO value. With the right composition and material preparation, CFA and CBA from the Sultan Azlan Shah Power Plant can be used as a cement replacement in concrete.

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