Midhat Nabil Ahmad Salimi
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Midhat Nabil Ahmad Salimi
Official Name
Midhat Nabil, Ahmad Salimi
Alternative Name
Ahmad Salimi, Midhat Nabil
Salimi, Midhat Nabil
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Scopus Author ID
54788410200

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  • Publication
    Preliminary studies on antimicrobial activity of extracts from aloe vera leaf, citrus hystrix leaf, zingiber officinale and Sabah snake grass against bacillus subtilis
    ( 2018)
    Muhammad Nur Aiman Uda
    ;
    Subash Chandra Bose Gopinath
    ;
    Nur Hulwani Ibrahim
    ;
    Mohd Khairul Rabani Hashim
    ;
    Nuradibah Mohd Amer
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Tan Ewe Shen
    ;
    Ong Yee Fen
    ;
    Maisara Azad Mat Akhir
    ;
    Uda Hashim
    Herbal plants have several potential antimicrobial activities either as antifungal or antibacterial to fight against the disease and pathogen that attack the plants. The extractions of the Aloe vera leaf, Citrus hystrix leaf, Zingiber officinale rhizome and Sabah snake grass were selected in this study to fight against Bacillus subtilis. B. subtilis is a Gram-positive bacterium, rodshaped and catalase-positive that lives on decayed organic material. It is known as Gram-positive bacteria because of its thick peptidoglycan and would appear purple when subjected to Gram test. This species is commonly found in the upper layers of the soil, in meat or vegetables, in pastry, cooked meat, in bread or poultry products. The extracts of Sabah Snake Grass found to be most effective than A.vera leaf, Z. officinale, and C. hystrix against the B. subtilis.
  • Publication
    Glucose production from sugarcane bagasse by two stages chemical pretreatment & hydrolysis
    (IOP Publishing, 2020)
    Nurul Syiffa Husna Che Roslan
    ;
    Midhat Nabil Ahmad Salimi
    The aim of this work was to produce glucose from sugarcane waste. It consists of high cellulose, hemicellulose and lignin which enables to be converted into a glucose production. Three conditions of acid hydrolysis was measured by using One Factor at a Time (OFAT) which consist of sulphuric acid concentration, retention time and temperature. The highest yield and optimum conditions from OFAT parameters were further continue with the enzymatic hydrolysis by using Central Composite Design (CCD). The optimization of enzymatic hydrolysis for the conversion of cellulose to glucose was conducted by using three independent variables which were pH, temperature and enzyme dosage. Based on the data of Design of Expert (DOE) software from optimization of enzymatic hydrolysis, the optimum glucose production was determined by using Dinitrosalicylic Acid Reagent (DNS) method.
  • Publication
    Optimization of Pretreatment and Enzymatic Hydrolysis of Spent Coffee Ground for the Production of Fermentable Sugar
    ( 2020-03-18)
    Jin L.S.
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Syazni Zainul Kamal
    The aim of this work was to optimize the condition of pretreatment and enzymatic hydrolysis for high yield of sugar production of spent coffee ground (SCG). Acid and alkaline pretreatment method were compared and the method with more sugar produced was selected. Response surface methodology was use for the analysis of conditions such as concentration of alkali, temperature and weight of SCG. The optimized condition obtained was 0.5% (v/v) of alkali, temperature of 100°C and 5% (w/v) of SCG. Enzymatic hydrolysis was carried out after the optimized condition of alkaline pretreatment. The conditions were pH, temperature and enzyme dosage. The optimized condition obtained was at pH 4.8, 0.01 ml of enzyme and temperature of 55°C.
      1  16
  • Publication
    Thermoplastic starch hybrid biocomposite films with improved strength and flexibility produced through crosslinking via carboxylic acid
    ( 2023)
    Di Sheng Lai
    ;
    Azlin Fazlina Osman
    ;
    Sinar Arzuria Adnan
    ;
    Ismail Ibrahim
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Mariatti Jaafar @ Mustapha
    Thermoplastic starch (TPS) suffers from its intrinsic low mechanical strength and high brittleness due to its strong hydrogen bonding and low chain mobility. The conventional way to crosslink the TPS film can improve the strength and stiffness of the films, but usually reduces the flexibility of the film, and increases its brittleness. In this study, the incorporation of the hybrid nanofiller [1 wt% nanocellulose (C) and 4 wt% nano bentonite (B)] into the TPS proved to improve greatly the films’ strength and flexibility. The hybrid nanofillers with ratio 4B:1C was incorporated into the crosslinked thermoplastic corn starch (CR-TPCS) film to increase the its flexibility and toughness and produced a high mechanical strength fully biodegradable film. Two different aqueous carboxylic acids: citric acid (CA) and tartaric acid (TA) with different pH values (2,4,6) as the green crosslinker were employed. Substantial increase of tensile strength (3.98 to 9.17 MPa), Young’s modulus (9.10 to 46.30 MPa) and elongation at break (55.2 to 135.7%) was observed for the CA- 4B1C/pH2 films compared to the CR-TPCS films. The melting temperature (Tm) of the CA-4B1C/pH2 improved compared to the TPCS/4B1C (un-crosslinked) film due to its crosslinking effect. Meanwhile, the CA-4B1C films exhibited the highest degree of substitution and di-esterification with the lowest swelling and water solubility properties due to the formation of a special “bridge” structure between the CA, nanocellulose and plasticizer. The “bridge” structure developed between the TPCS chains serves as the toughener to motivate higher chain stress relaxation and load endurance. The crosslinked “bridge structure” also proved to effectively reduce the retrogradation phenomenal in the TPCS films. This combination method of hybridization and crosslinking is an efficient, low cost, and environmentally friendly technique to overcome the low flexibility and brittleness problem of the TPS based packaging film.
      2  32
  • Publication
    A review on additive manufacturing in bioresorbable stent manufacture
    ( 2021-07-21)
    Noorhafiza Muhammad
    ;
    Azli A.A.
    ;
    Mohd Shuhidan Saleh
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Mohd Fathullah Ghazli@Ghazali
    ;
    Shayfull Zamree Abd. Rahim
    Vascular injury and disease as well as cardiac and cardiovascular diseases have been a serious threat to human life and health today. Stents implantation have been the primary treatment for vascular diseases. Polymeric bioresorbable stents manufactured with 3D printer is newly emerged. This work review the bioresorbable stents and the utilization of additive manufacturing in bioresorbable stent manufacture.
      2  37
  • Publication
    Production of Iron Oxide nanoparticles by co-precipitation method with optimization studies of processing temperature, pH and stirring rate
    (IOP Publishing, 2020)
    Beh Hui Hui
    ;
    Midhat Nabil Ahmad Salimi
    Iron Oxide Nanoparticle, maghemite (γ-Fe2O3) has received great interest and extensively used in biomedical field. Optimization studies were carried out in the production of γ-Fe2O3 nanoparticles by using co-precipitation method. Iron (II) chloride and iron (III) chloride were used as precursors which are dissolved in distilled water followed by centrifugation, drying and grinding process in order to obtain dried dark brown precipitated γ-Fe2O3 powder. The effect of different processing temperature (30 to 70°C), pH (10 to 12) and stirring rate (300 to 700rpm) towards crystallite size of γ-Fe2O3 were investigated by using Response Surface Methodology (RSM) and Central Composite Design (CCD). Based on analysis of variance (ANOVA), the determination coefficient, R2 obtained was 0.9890 where stirring rate was the parameter that affected the most on the crystallite size. Optimization processing condition that produce smallest crystallite size of 7.3657 nm was 50 °C, pH 11.40 and 550 rpm by using Design of Expert software (DOE). Characterization of γ-Fe2O3 powder samples were evaluated by using different analytical tools such as Fourier Transform Infrared (FTIR), X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). Iron oxide group (Fe-O), hydroxyl (OH-) group and carbon dioxide (CO2) were identified in FTIR spectrum. The characteristic peak occurring at 2θ = 35.4° indicated presence of γ-Fe2O3 in the samples. The γ-Fe2O3 particles appeared generally in spherical shape in SEM analysis.
      6  13
  • Publication
    Experimental study on laser welding dissimilar materials
    ( 2021-07-21)
    Noorhafiza Muhammad
    ;
    Yap How Hean
    ;
    Mohd Shuhidan Saleh
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Mohd Fathullah Ghazli@Ghazali
    ;
    Muhamad Farizuan Rosli
    Laser welding on dissimilar materials is widely used and has significance application in industry. Laser welding is the one of the method which can offer high strength of joint especially for joining of dissimilar metals contrast to conventional method. Conventional welding more often had an insufficient penetration depth and a wider heat affected zone which prompts to reduce joint quality. This work exhibits a weld possibility on low carbon steel and high carbon steel surface utilizing low power fiber laser in pulse wave modes. The objective of this research work is to investigate the influence of laser welding parameters of welding speed and pulse width on weld geometry of the welded metal. The parameters used is the welding speed (1.67 mm/s to 8.33mm/s) and pulse width (3 ms to 5 ms). The optimum weld geometry was with the largest aspect ratio (1.42) with parameter of welding speed (1.67 mm/s) and pulse width (3.0 ms). As conclusion, appropriate utilization of parameters can improve the quality of weld joints and durability of products.
      2  32
  • Publication
    Influence of carbonization conditions and temperature variations on the characteristics of coconut shell carbon
    ( 2024-03)
    Yee Wen Yap
    ;
    Nurul Najiha Abu Bakar
    ;
    Norsuria Mahmed
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Siti Norsaffirah Zailan
    ;
    Azlin Fazlina Osman
    ;
    Kamrosni Abdul Razak
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Yusry Mohamad Yunus
    This research aims to study the impact of carbonization atmospheres (ambient and nitrogen) and temperature on the properties of the coconut shell carbon (CSC) formed. To characterize the properties of CSC, the char yield percentage was calculated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of CSC while X-ray Diffraction (XRD) analysis was done to identify the degree of graphitization. The carbon formed by carbonization under the nitrogen atmosphere yields lower char percentages compared to the ambient atmosphere. When the carbonization temperature elevated, both atmospheres produced a lower char yield percentage. This result is aligned with the SEM analysis where more and larger pores were observed from the carbon produced at higher temperatures and the result was further enhanced under a nitrogen atmosphere. It was found that the char yield of CSC decreased from 20.9% to 11.4% when the carbonization temperature increased from 400°C to 1000°C under the ambient atmosphere. More significant changes were formed through the carbonization process under the nitrogen atmosphere (from 18.3% to 6.03%). Pores formed when the volatile materials are released due to the elevated carbonization temperature, resulting in a reduction in total weight thus, the char yield percentage. From the XRD, all CSC produced from both atmospheres with varying temperatures poses an amorphous XRD pattern. However, the right shifted peak and the presence of an additional peak of ~40° suggest that under different temperatures and atmospheres, the crystallinity of the CSC produced was affected. This research provides insight for optimizing CSC production in the future to enhance the application of CSC.
      1  19
  • Publication
    Preliminary studies on antimicrobial activity of extracts from aloe vera leaf, citrus hystrix leaf, zingiber officinale and Sabah snake grass against bacillus subtilis
    ( 2018)
    M.N.A. Uda
    ;
    Subash Chandra Bose Gopinath
    ;
    Nur Hulwani Ibrahim
    ;
    Mohd Khairul Rabani Hashim
    ;
    Nuradibah Mohd Amer
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Tan Ewe Shen
    ;
    Ong Yee Fen
    ;
    Maisara A. M. Akhir
    ;
    Uda Hashim
    Herbal plants have several potential antimicrobial activities either as antifungal or antibacterial to fight against the disease and pathogen that attack the plants. The extractions of the Aloe vera leaf, Citrus hystrix leaf, Zingiber officinale rhizome and Sabah snake grass were selected in this study to fight against Bacillus subtilis. B. subtilis is a Gram-positive bacterium, rodshaped and catalase-positive that lives on decayed organic material. It is known as Gram-positive bacteria because of its thick peptidoglycan and would appear purple when subjected to Gram test. This species is commonly found in the upper layers of the soil, in meat or vegetables, in pastry, cooked meat, in bread or poultry products. The extracts of Sabah Snake Grass found to be most effective than A.vera leaf, Z. officinale, and C. hystrix against the B. subtilis.
      1  17
  • Publication
    Toughening mechanism of thermoplastic starch nano-biocomposite with the hybrid of nanocellulose/nanobentonite
    (Elsevier, 2023)
    Lai Di Sheng
    ;
    Azlin Fazlina Osman
    ;
    Sinar Arzuria Adnan
    ;
    Mariatti Jaafar@Mustapha
    ;
    Ismail Ibrahim
    ;
    Midhat Nabil Ahmad Salimi
    High flexibility and toughness are key criteria for an effective bioplastic packaging film. However, in most studies, the flexibility of thermoplastic starch (TPS) films is always neglected when targeting their tensile strength improvement. Low film flexibility has limited the development of TPS films in replacing the petrochemical-based plastic packaging films. In this communication, we report a method to produce thermoplastic corn starch (TPCS) films with excellent mechanical strength, high flexibility and high toughness through the hybridization of two natural nanofillers: nanobentonite and nanocellulose. The synergistic effect of the hybrid nanofillers can be observed through the arrangement of alternating nacre structures where the nanobentonite silicate layers are responsible for mechanical strength, while the nanocellulose promotes free volume in the TPCS matrix and triggers high film elongation at break. Structural, morphological, and thermomechanical analysis were conducted, and the detailed strengthening mechanism of the TPCS hybrid nano-biocomposite films was revealed.
      5  29