Publications by authors named "Parvaneh Nakhostin Panahi"

Fe-Ca-SAPO-34/CS/PANI, a novel hybrid bio-composite scaffold with potential application in dental tissue engineering, was prepared by freeze drying technique. The scaffold was characterized using FT-IR and SEM methods. The effects of PANI on the physicochemical properties of the Fe-Ca-SAPO-34/CS scaffold were investigated, including changes in swelling ratio, mechanical behavior, density, porosity, biodegradation, and biomineralization.

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This research aimed to design innovative therapeutic bio-composites that enhance odontogenic and osteogenic differentiation of human dental pulp-derived mesenchymal stem cells (h-DPSCs) in-vitro regeneration. Herein, we report the fabrication of scaffolds containing chitosan, Ca-SAPO-34 monometallic and/or Fe-Ca-SAPO-34 bimetallic nanoparticles by freeze-drying technique. The scaffolds and nanoparticles were characterized using ICP-AES, FT-IR, XRD, TGA, TEM, BET, SEM, and EDS methods.

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The selective catalytic reduction of NO with ammonia (NH-SCR) was studied over Cu-ZSM-5 nanocatalysts which were prepared by several methods, including conventional ion-exchange (IE), conventional impregnation (IM), ultrasound-enhanced impregnation (UIM), and conventional deposition-precipitation (DP) using NaOH and homogeneous deposition-precipitation (HDP) using urea. The nanocatalysts were subsequently characterized by Fourier transform infrared spectroscopy, temperature-programmed reduction with hydrogen (H-TPR), ammonia temperature-programmed desorption (NH-TPD), X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller. The catalytic activity of the Cu-ZSM-5 nanocatalysts for NO removal decreased in the following order: Cu-ZSM-5 (HDP) > Cu-ZSM-5 (UIM) > Cu-ZSM-5 (IM) > Cu-ZSM-5 (IE) > Cu-ZSM-5 (DP).

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The influence of the various preparation methods of Cu-SAPO-34 nanocatalysts on the selective catalytic reduction of NO with NH3 under excess oxygen was studied. Cu-SAPO-34 nanocatalysts were prepared by using four techniques: conventional impregnation (IM), ultrasound-enhanced impregnation (UIM), conventional deposition precipitation (DP) using NaOH and homogeneous deposition precipitation (HDP) using urea. These catalysts were characterized in detail by various techniques such as N2-sorption, XRD, TEM, H2-TPR, NH3-TPD and XPS to understand the catalyst structure, the nature and the dispersed state of the copper species, and the acid sites for NH3 adsorption.

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In this study, the effects of operation variables on catalytic performance of CeO2-MnOx (0.25)-Ba mixed oxide in catalytic reduction of NO with ammonia are investigated by using design of experiments. A response surface methodology (RSM) combined with the central composite design (CCD) is used to model and optimize the process variables, including concentration of 02 (vol.

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Article Synopsis
  • A central composite design was used to optimize the preparation of Mn/active carbon nanocatalysts for the NH3-SCR of NO at 250°C, comparing results with predictions from an artificial neural network (ANN).
  • Key preparation parameters included metal loading, calcination temperature, and the degree of pre-oxidization, all of which significantly influenced catalyst efficiency, with optimal conditions identified for maximum NO conversion.
  • While both models showed good predictive accuracy, the ANN outperformed the response surface methodology, with lower mean square error and higher R2 values, demonstrating its effectiveness in capturing the system's nonlinear behavior.
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Preparation of Cu/Activated Carbon (Cu/AC) catalyst was optimized for low temperature selective catalytic reduction of NO by using response surface methodology. A central composite design (CCD) was used to investigate the effects of three independent variables, namely pre-oxidization degree (HNO3%), Cu loading (wt.%) and calcination temperature on NO conversion efficiency.

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