WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

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

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  • Article
    A Phenomenological Kinetic Flotation Model: Intrinsic Floatability Profiling for Batch and Continuous Flotation Systems
    (Springer Heidelberg, 2026) Polat, Mehmet; Guzel, Veli; Kobas, Muammer; Polat, Hurriyet
    This study presents a mechanistic flotation kinetics model that unifies the description of mineral particle floatability in both batch and continuous systems. Building on a physically explicit interpretation of bubble-particle interactions, the model introduces the concept of intrinsic floatability, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\upphi }_{\text{P},\text{ij}}<^>{\text{s}}$$\end{document}, defined as the size-and composition-dependent probability that a particle within a bubble's sweep volume reports to the froth. A central feature of the framework is that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\upphi }_{\text{P},\text{ij}}<^>{\text{s}}$$\end{document} is decoupled from system-level rate-determining factors, such as bubble-particle encounter frequency, transport limits, and bubble surface crowding-that otherwise confound attempts to extract floatability distributions from kinetic data. This separation is achieved through three explicit, time-dependent parameters: the encounter rate kappa(t), the limiting flotation rate mu(t), and the bubble saturation factor chi(t). Together, these parameters isolate intrinsic particle behavior from external constraints. The model naturally reduces to the classical first-order rate law in dilute pulps, while in concentrated suspensions it predicts systematic deviations, approaching zero-order kinetics as bubble surfaces saturate. Importantly, the same formulation applies seamlessly to batch tests and multi-stage continuous circuits, enabling a consistent theoretical framework across scales and ore types. Requiring only standard flotation data and known system parameters, the model is practical for both laboratory coal flotation studies and industrial non-coal applications. Validation using batch coal data and continuous plant-scale copper flotation results demonstrates its robustness and broad relevance.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 15
    Investigation of the Effect of Gel Properties on Supercritical Drying Kinetics of Ionotropic Alginate Gel Particles
    (Elsevier, 2019) Şahin, İbrahim; Uzunlar, Erdal; Erkey, Can
    A series of spherical ionotropic alginate gel particles with different diameters ranging from 2.8mm to 5.0mm and porosities ranging from 0.899 to 0.976 were prepared by dripping a Na-alginate solution into a solution of salts of divalent cations (Ca2+, Mn2+, Ni2+, Co2+, Cu2+ and Zn2+). After solvent exchange with ethanol, kinetics of supercritical drying of these ionotropic alginate gel particles in a packed bed was investigated at 308-338 K and 100-120 bar. Experimental data were compared with predictions of a model which considers diffusive transport inside the pores and convection in the flowing fluid stream. The model predicted drying profiles by taking into account only the changes in porosity and diameter of the gel particles. A convective mass transfer coefficient correlation that was originally developed for supercritical drying of Ca-alginate gel particles was found to be suitable for M-alginate gel particles. (C) 2019 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 23
    Citation - Scopus: 24
    Investigation of Kinetics of Supercritical Drying of Alginate Alcogel Particles
    (Elsevier Ltd., 2019) Şahin, İbrahim; Uzunlar, Erdal; Erkey, Can
    Spherical calcium alginate gel particles were synthesized by dripping method. The effects of temperature, pressure, particle size and CO2 flow rate on kinetics of supercritical drying of alginate gel particles in a packed bed were investigated. Increase in CO2 flow rate, increase in temperature and decrease in particle size increased the drying rate and decreased the drying time. A mathematical model based on (i) the diffusion of the solvent inside the pores of gel particles, (ii) external mass transfer of the solvent from the surface of the gel particles into the flowing fluid stream, and (iii) convection and axial dispersion of the solvent in the flowing fluid stream was developed. A correlation for predicting external mass transfer coefficients for supercritical drying of alcogel particles was developed by fitting the model to experimental data. A good agreement between the experimental data and model results was achieved using the developed correlation.
  • Article
    Citation - WoS: 38
    Citation - Scopus: 43
    Degradation Kinetics of Anthocyanins From Sour Cherry, Pomegranate, and Strawberry Juices by Hydrogen Peroxide
    (John Wiley and Sons Inc., 2002) Özkan, Mehmet; Yemenicioğlu, Ahmet; Asefi, N.; Cemeroglu, Bekir
    Degradations were studied at different hydrogen peroxide (H2O2] concentrations (9.31 to 27.92 mmol. L-1] over a range of 10 ° to 30 °C. Degradation of anthocyanins by H2O2 was described by first-order function. Comparison of t1/2 values revealed that sour cherry anthocyanins were the most resistant to H2O2, followed by pomegranate and strawberry anthocyanins. Thus, the removal of residual H2O2 from the juice contact surfaces of aseptically packaged strawberry juices should be controlled more carefully to prevent anthocyanin degradation. Respective Ea values were between 9.4 to 11.1, 9.5 to 11.4, and 11.4 to 12.2 kcal.mol-1; and Q10 values between 1.59 to 2.22, 1.62 to 2.05, and 1.76 to 2.36 for strawberry, sour cherry, and pomegranate anthocyanins.