Journal Articles

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https://hdl.handle.net/20.500.14170/1585

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Browsing Journal Articles by Author "Abdullah Abdul Samad"
  • Publication
    Electrode reaction routes analyses of modified Ni-BCZY anode via distribution relaxation times: 1-D interpretation
    (Elsevier, 2025-03)
    Lidyayatty Abdul Malik
    ;
    Abdullah Abdul Samad
    ;
    Abdul Mutalib Md Jani
    ;
    Zadariana Jamil
    ;
    Nur Hidayati Othman
    ;
    Chung-Jen Tseng
    ;
    Nafisah Osman
    Proton ceramic fuel cells (PCFCs) represent a promising avenue for energy conversion, with their electrochemical performance heavily relying on the architecture of the cell particularly at the electrode counterparts. One of the measurements used to study their underlying chemical processes is via the electrochemical impedance spectroscopy (EIS) technique. This study aims to interpret 1-D electrode reaction routes of a single cell decorated with unmodified BCZY (p-BCZY) as an electrolyte, Ni-modified BaCe0.54Zr0.36Y0.1O2.95 (Ni-m-BCZY) as anode substrate, Ni-p-BCZY (10:90) as anode functional layer 1 (AFL1), Ni-p-BCZY (30:70) as anode functional layer 2 (AFL2), and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) as cathode side. Distribution relaxation times (DRT) corroborate with complex non-linear least squares (CNLS) analyses are being applied to illustrate 1-D electrode reaction routes within the fabricated cell. This approach allows for the precise elucidating of rate-limiting polarization processes and distinguishing between anodic and cathodic reactions. The extracted eight sub-processes represented by respective peaks are adopted to depict an illustration of the charge carrier's pathway for underlying understanding. At an operating temperature of 700 °C, the polarization resistance (Rp) obtained via DRT and CNLS is 1.02 Ω cm2 and 1.13 Ω cm2 respectively. To establish the CNLS and DRT analyses and 1-D interpretation of the cell; (a) impedance data at T = 600 °C and T = 500 °C and (b) cross-section FESEM images are also discussed.
  • Publication
    Numerical modelling and optimization of thermal performance of heat sink with uniform cross-sectional area using shape optimized Al₂O₃-SiC nanoparticles in base fluid
    (Semarak Ilmu Publishing, 2025-01)
    Ammembal Gopalkrishna Pai
    ;
    Rekha Gopalkrishna Pai
    ;
    Abdullah Abdul Samad
    ;
    Akshatha Bekal Laxmish
    This study explores the flow characteristics of proposed “Integrated hybrid nanofluid heat sink model (IHNFHSM)” with a novel mixture of Al₂O₃–SiC nanoparticles of various shape in base fluid. The primary objective is to evaluate the influence of various similarity parameters on the heat transfer performance of the fin structure subjected to convective and insulated tip boundary conditions. A novel combination of Al₂O₃–SiC hybrid nanoparticles offer a significant potential for improved dissipation of heat in engineering applications. The analysis is carried out using Darcy's model, incorporating temperature-dependent natural convection, and radiation effects. The governing energy equations are non - dimensionalized and solved using three stage Lobatto quadrature numerical technique with suitable boundary conditions. The results provide insight into the effect of similarity parameters on the thermal performance of the system under consideration. Quantitatively, the findings reveal an increase of 23% in the thermal conductivity of base fluid with hybrid nanoparticles. The heat transfer rate of convective fin tip was enhanced by an average of 17.13% at   = m2 = 1 compared to an insulated fin tip. An optimal thermal performance of the model in terms of heat transfer rate was observed by an enhancement of 100% in   and m2 values from 10 to 20. Additionally, dimensionless fin temperature at  = 1 enhanced by 12.16% for the lamina – lamina shape combination of nanoparticles over lamina – spherical, clearly showing its dominance in the thermal performance over the rest of the combinations.
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