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Hydrodynamics in stirred vessels is vital for transport phenomena for various applications in chemical and environmental systems like aerobic and anaerobic systems, effluent treatment and biological applications like bioreactors. Design of efficient impellers reduces power consumption which contributes to reduction in greenhouse gases especially power obtained from thermal power plants thus decreasing the carbon footprint. In the present work, Computational Fluid Dynamics (CFD) simulations have been carried out for two different Rushton turbines (one axial and one radial flow) for two different height to diameter (H/T) ratio. The model is first validated for a Pitched Blade Turbine Downflow (PBTD) impeller with data available in the literature. A qualitative study of the flow patterns in stirred tanks shows good axial and radial flow profiles for the respective impellers. A decrease in H/T showed higher power consumption for both impellers. The power number (Np) for these impellers has also been calculated for two H/T ratio and Reynolds number (Re) in the range (2500 < Re < 1000. Np was found to be a strong function of liquid level for both impellers considered in the study. Interesting trends of variation of Np with Re have been observed which suggest there is a critical Re where the impellers have least power consum

The e-commerce business has grown significantly over the past few years, mainly due to providing a better customer experience through advance booking and order cancellation options with a full refund. In this paper, the inventory control problem of a firm that offers advance booking for the product and cancellation (with a full refund) before the due delivery date is addressed. A profit maximization model is formulated to find the optimum inventory cycle length, the selling price of the product, and advertisement expenditure. The discounted cash flow approach is used to take into account cash flows at different time points. Advance booking is made at the beginning of the inventory cycle at a discounted price until the time of stock arrival, followed by usual spot sales. The number of order cancellations during the advance booking period is dependent on the waiting time for receiving the order. The impact of revenue collected through advance sales is considered by including interest earned. Product demand is assumed to be the function of advertisement expenditure and the selling price of the product. A solution procedure is suggested, and the model is illustrated through numerical analysis, thereby providing valuable managerial insights based on the results obtained.

Flexible and stretchable supercapacitors developed on MXene‐enabled Titanium Carbide (TiC) impurities‐based electrodes with novel electrolytes are the point of focus in this work. Five different electrodes are prepared with different TiC content and symmetric supercapacitors are fabricated with three electrolytes named acrylamide, N,N′‐Dimethylacrylamide, and 2‐Hydroxyethyl methacrylate to achieve flexibility and improved energy storage. Before electrode fabrication, all the samples are tested with the X‐ray Diffraction technique. Cyclic voltammetry is performed at a potential window from −1 to 1 V to evaluate the specific capacitance of fabricated supercapacitors at multiple scan rates. Electrochemical impedance spectroscopy is performed to study the Randles circuit, and Rs values are calculated to examine the maximum physical area used for the evaluation of supercapacitors. Open‐circuit and short‐circuit tests are performed after charging the capacitor at 1 V for 2 min each time and compatibility of electrodes with different electrolytes is analyzed. The figures of merits for all the techniques used are discussed in detail. The highest values of the specific capacitances reported in our work are 50 and 79 F/g with novel electrolytes termed as N,N′‐Dimethylacrylamide and 2‐Hydroxyethyl methacrylate, respectively. [ABSTRACT FROM AUTHOR]

This study focuses on the large-scale production of a high-energy-density supercapacitor through the cost-effective polymerization of a PANI/Cr2O3/graphene nanocomposite, utilizing commercially available flexible substrate and cost-effective chemicals. To explore the synergistic effect, a PANI/Cr2O3/graphene nanocomposite is evaluated in a hybrid gel electrolyte with varying polyvinyl alcohol (PVA) concentrations. The investigation is aimed at enhancing the electrochemical performance of electrode material for supercapacitors. Two symmetric devices are fabricated to assess the specific capacitance and energy density of the prepared nanocomposite. In the PVA2g/Na2SO4 electrolyte, the energy density is increased to 61.71 Wh kg−1, accompanied by an enhanced potential window of 1.95 V. Furthermore, the prepared composite demonstrates good electrochemical stability, retaining 94% of its initial capacitance after 2000 cycles at 2 Ag−1 in 2 g PVA/Na2SO4 gel electrolyte. The remarkable electrochemical properties of the composite can be attributed to the effective contact and synergistic effect among PANI, Cr2O3, and graphene, making it a promising candidate for supercapacitor applications. Moreover, this facile process is easily scalable to meet commercial demands and can be utilized to enhance the energy density of various carbon-based materials with limited initial performance. [ABSTRACT FROM AUTHOR]