Razi Ahmad
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Preferred name
Razi Ahmad
Official Name
Razi, Ahmad
Alternative Name
Ahmad, Razi
Ahmad, R. B.
Ahmad, R.
Ahmad, R. Badlishah
Main Affiliation
Scopus Author ID
54419444500
Researcher ID
B-9254-2012

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  • Publication
    Bio-Char And Bio-Oil Production From Pyrolysis of Palm Kernel Shell And Polyethylene
    ( 2023-01-01)
    Ibrahim N.R.
    ;
    Razi Ahmad
    ;
    Wan Amiza Amneera Wan Ahmad
    ;
    Vikneswaran Vijean
    ;
    Ragunathan Al Santiagoo
    ;
    Syakirah Afiza Mohammed
    ;
    Khalid A.F.
    ;
    Ani A.Y.
    In recent years, palm kernel shell (PKS) has become a viable feedstock for making biofuels and value-added commodities using a variety of thermal conversion routes. Therefore, significant conservation is required for PKS as a resource for fuel production in biofuel facilities. Thus, this research was intended to elucidate the effects on PKS as a solid fuel through torrefaction and the production of bio-char and bio-oil by single and co-pyrolysis of PKS and polyethylene (PE). The PKS was treated through torrefaction at different temperatures and holding times. The optimum parameters for torrefaction were a temperature of 250 oC and a holding time of 60 min. Then the PKS and PE were pyrolyzed in a fixed-bed reactor at different temperatures and ratios. The product yield was analysed for single and co-pyrolysis of PKS and PE for pyrolysis. The properties of the product composition for single and co-pyrolysis of the PKS and PE were determined by proximate analysis, Fourier transform infrared (FTIR) analysis, and gas chromatography-mass spectrometry (GC-MS). The optimum parameter obtained for biochar and bio-oil production from co-pyrolysis of PKS and PE was at temperature of 500 oC at a ratio of 1:2 (PKS: PE). The ester and phenol compounds were increased around 19.02 to 23.18% and 32.51 to 34.80 %, respectively, while amide and amine decreased around 4.94 to 18.87% and 0.63 to 32.39 %, respectively, compared to the single pyrolysis of PKS. Therefore, the PKS and PE co-pyrolysis significantly increased the amount of phenol and ester compounds while slightly reducing the amount of amide and amine compounds in the bio-oil product. As a conclusion, biomass conservation enables the manufacturing of value-added chemicals.
  • Publication
    Compatibilizers Effect on Recycled Acrylonitrile Butadiene Rubber with Polypropylene and Sugarcane Bagasse Composite for Mechanical Properties
    ( 2023-10-16)
    Zainal M.
    ;
    Ragunathan Al Santiagoo
    ;
    Razi Ahmad
    ;
    Mohammed S.A.
    ;
    Abdul Ghapar Ahmad
    ;
    Vikneswaran Vijean
    ;
    Wan Amiza Amneera Wan Ahmad
    ;
    Allan Melvin Andrew
    Compatibilizers effect on recycled acrylonitrile butadiene rubber (NBRr) with polypropylene (PP) and sugarcane bagasse (SCB) composite for mechanical properties is evaluated. Trans-Polyoctylene Rubber (TOR) and Bisphenol a Diglycidyl Ether (DGEBA) are used as compatibilizers in this study. Three (3) different composites (80/20/15, 60/40/15, and 40/60/15), with fixed filler (15 phr) and compatibilizers (10 phr) content, were carried out. These composites were arranged via melt mixing technique utilizing a heated two-roll mill at a temperature of 180 C for 9 minutes employing a 15-rpm rotor speed. Tensile and morphological properties were evaluated. The result shown average tensile strength dropped by 48.50% as the recycle NBR content rises 20 phr. Nevertheless, subsequent compatibilization reveals that the compositesâ tensile properties were all greater than control composites. The morphology discovered validates the tensile properties, indicating a stronger interaction between the PP/SCB and recycle NBR composites with the addition of compatibilizer DGEBA.
  • Publication
    Influence of pretreated coconut shell on gasification product yield
    ( 2023-10-16)
    Muda S.Z.
    ;
    Razi Ahmad
    ;
    Syakirah Afiza Mohammed
    ;
    Wan Amiza Amneera Wan Ahmad
    ;
    Vikneswaran Vijean
    ;
    Ibrahim N.R.
    ;
    Ani A.Y.
    ;
    Ragunathan Al Santiagoo
    Gasification of untreated and pretreated coconut shell (CS) was carried out in a fixed-bed reactor to assess the effect of temperature (600, 650, 700, 750, and 800 C) and holding time (30 and 40 min) on gases composition. The untreated CS was first torrefied in a fixed-bed reactor at different temperatures (200 â 300 C) and holding times (30 min, 60 min and 90 min). Pretreated CS at the optimal torrefaction temperature (275 C and 60 min) was used for gasification. Under optimal conditions of 750 C and 30 min holding time, gasification contributed the most gas production. At this optimum condition, the gas composition of pretreated CS was 35.03 % of CH4, 24.43 % of CO2, and 40.54 % of H2 + CO. Untreated CS contains 37.63 % of CH4, 24.03 % of CO2, and 38.34 % of H2 + CO gases. The production of CH4 gas was higher when untreated CS was used for gasification rather than pretreated CS. Moreover, when untreated CS was used for gasification, the amount of CO2, H2, and CO produced was minimal. Therefore, for high H2 production, pretreatment prior to gasification is appropriate.
  • Publication
    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.
  • Publication
    Influence of Torrefaction on Sewage Sludge
    ( 2023-01-01)
    Razi Ahmad
    ;
    Abdul Ghapar Ahmad
    ;
    Mohammed S.A.
    ;
    Wan Ahmad W.A.M.
    ;
    Vikneswaran Vijean
    ;
    Ragunathan Al Santiagoo
    ;
    Ibrahim N.R.
    ;
    Udin N.
    Sewage sludge (SS) from sewage treatment plants has been seen as a waste for decades and little attention to investigate the potential and its beneficial product. SS contain a large amount of recoverable energy; however, it has high moisture, ash, heavy metals, and organic contents. Thus, the goal of this research is to use torrefaction to produce upgraded or torrefied SS. The proximate and ultimate analysis was used to determine the physical and chemical characteristic of raw SS. Torrefaction was performed through inert atmosphere in fixed bed reactor. According to the findings, at torrefaction temperature of 300 °C, torrefaction had improved the quality of raw SS, increasing its fixed carbon content by 47.8%, and its moisture content by 61.3%. The optimum temperature for torrefaction was at 300 ℃ with holding time of 60 minutes. This study improved the quality of sewage sludge to be utilised in subsequent thermochemical conversion.
      2  18
  • Publication
    Predictive Maintenance System Design for Infant Intensive Phototherapy Lamp
    ( 2022-01-01)
    Vikneswaran Vijean
    ;
    Razi Ahmad
    ;
    Wan Amiza Amneera Wan Ahmad
    ;
    Ragunathan Al Santiagoo
    ;
    Abdul Ghapar Ahmad
    ;
    Syakirah Afiza Mohammed
    Planned-Preventive maintenance (PPM) is an essential part of clinical engineering to ensure correct functionality of the medial equipment. PPM involves the extension of equipment's life and reducing failure by performing selective substitution of its components in contrast to the "fix it when it fails"concept. However, this strategy often leads to un-necessary downtime and increased costs, especially in hospital environment. Therefore, a maintenance system for predictive preventive maintenance that can monitor the usage of medical equipment is much preferred option. In this regards, a predictive maintenance system design is proposed that focuses on the LED Infant Intensive Phototherapy Lamp. In order to improve the weakness arise from the schedule Planned-Preventive Maintenance (PPM), the predictive maintenance system will be real time performance based in which the performance of the LED Infant Intensive Phototherapy Lamp will be monitored. The purpose of this monitoring system is to ensure that the light intensity, which is measured in irradiance level, can be delivered in sufficient amount for the baby with jaundice. In order to monitor the performances of LED infant intensive phototherapy lamp, a cloud based webpage has been implemented for real time monitoring of LED infant intensive phototherapy lamp which can be accessed by authorized personals.
      25  1
  • Publication
    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.
      24  1
  • Publication
    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.
      17  1
  • Publication
    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.
      17  1