WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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2025 - 20262

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Author: search.filters.author.Sotudeh-Gharebagh, RahmatPublisher: search.filters.publisher.Elsevier

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  • Article
    Vibration-Assisted Fluidization of Nanocellulose
    (Elsevier, 2026) Salimi, Sina; Hoorijani, Hamed; Zarghami, Reza; Sotudeh-Gharebagh, Rahmat; Van Geem, Kevin M.
    Nanocellulose, a renewable nanomaterial prized for its mechanical strength, biocompatibility, and tunable properties, faces challenges in gas-solid fluidization due to nanoparticle agglomeration, weak gas-solid interactions, and high elutriation caused by strong interparticle forces. This study uses pressure fluctuation analysis across frequency and time-frequency (wavelet transform) domains to investigate nanocellulose fluidization in a gas-solid bed. Mechanical vibration was introduced to optimize fluidization, with effects compared against nonvibrated conditions. Results show vibration significantly reduces agglomerate size and enhances bed expansion, improving fluidization efficiency. Notably, vibration lowers the minimum gas velocity requirement by approximately 4-fold. Pressure fluctuation analysis reveals that vibration amplifies low-frequency energy, fostering smaller bubbles and shifting energy contributions from large agglomerates to finer hydrodynamic structures. This shift correlates with intensified agglomerate interactions, leading to breakup and size reduction. Finally, the effect of introducing a powder additive to the nanocellulose bed on the hydrodynamics was examined, showing a moderate rise in macroscale energy at 1 % additive loading and a pronounced shift at 2 %, where macro structures accounted for nearly 45 % of the spectral energy. Overall, these findings underscore vibration-assisted fluidization as a promising method for scalable nanocellulose processing, offering actionable insights for advancing industrial applications.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 3
    Exploration of Electrostatics Effect on Dispersion and Coating Mechanisms in Dry Powder Inhalers by Discrete Element Method
    (Elsevier, 2025) Saeid, Pooya; Kazemi, Saman; Zarghami, Reza; Sotudeh-Gharebagh, Rahmat; Mostoufi, Navid
    Improving drug delivery in the respiratory system relies on the effective coating and dispersion of active pharmaceutical ingredients (APIs) in dry powder inhalers (DPIs) and the respiratory system's airways. This study aims to explore the impact of different factors on coating APIs on carrier particles, considering electrostatic and van der Waals forces using the discrete element method (DEM). This study focuses on the critical elements of API dispersion, specifically collisions between API-coated carrier particles with each other and DPI walls. The factors influencing the dispersion ratio in these collisions, such as impact velocity, contact angle, and particle charge, are examined. Additionally, a reduced-scale shaking DPI with three frequencies is used to investigate the API coating mechanism on carriers, which was not explored in previous studies. The difference in work function between carrier particles and APIs generates charge in the shaking DPI due to collisions. This causes electrostatic force to dominate over van der Waals force, breaking agglomerates and attaching APIs to carrier particles. This study shows that the amount of generated charge increases with particle collisions and that charge distribution becomes more balanced over time through charge exchange between particles. By elucidating the relationships among impact velocity, dispersion ratio, shaking frequency, and contact angles, this study paves the way for future research on more efficient DPI designs.