The Behavior of a Falling Particle in a Funnel

Recent theoretical work has suggested that a frictional, inelastic, spherical particle falling under gravity through a symmetric funnel will display interesting behavior as a function of the angle of the funnel walls. We have studied this system experimentally, using high-speed video to record the particle trajectories. By analyzing the video images, we have analyzed the time the ball spends in the funnel and its energy loss as functions of the angle of the walls with respect to the horizontal. The coefficient of restitution was also varied by using different balls and funnel materials. We found some similarities and differences between our results and the theoretical results

Microwave and Ultrasonic Assisted Synthesis of zeolites from Coal Fly Ash in Batch and Circulating Batch Operation

This research was focused on the production of zeolites from CFA throughutilizing ultrasound and microwave power. The initial conventional heating process of 6 h prior to microwave irradiation for samples with high solid-to-liquid (S/L) ratio (CFA mass/ NaOH solution volume) led to a higher yield of zeolite and decreased the synthesis time and consumption of energy,while keeping the high quality of the synthesized zeolite intact. The crystal growth of the nuclei generated over 6 h of conventional hydrothermal treatment was enhanced by the post-microwave heating. Ultrasound-assisted zeolitizationCFA was also applied in this research. When ultrasound energy was applied after hydrothermal treatment, crystal growth of zeolite nuclei was enhanced. However, when ultrasound irradiation was applied in the early stage; non-hydrothermal treated mixture, crystallization of zeolite was prevented. Ultrasound energy increased the pore diameter and surface area of the synthesized product. The ultrasound-assisted hydrothermal system enhanced the rate of nucleation and decreased the crystallization time during the synthesis process. The present technique could be considered an economic, eco-friendly, and fast conversion process. This study has shown that zeolites were successfully synthesized from CFA by utilizing microwave and ultrasound irradiation. These novel energy sources significantly decreased the zeolitizationprocess time. The single-mode microwave-assisted synthesis at high S/L ratio has been shown to be much more effective in producing the same results at a lower S/L ratio. On the other hand, utilization of an ultrasound probe produced a single-phase zeolite in a very short synthesis time compared to other conventional methods

Gaussian process regression with levy flight optimization: Advanced AR66 adsorption studies

International audienceThe coal fly ash (CFA), which is the residue generated by coal-fired power plants, was converted into a valuable zeolite material known as zeolite P (ZNa-P) through thermal and acid pretreatments followed by microwave radiation. Various analytical techniques were utilized to analyze the resulting zeolite, including X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, BET analysis, and zeta potential measurement. The efficiency of ZNa-P in eliminating anionic dyes from aqueous solutions was exhibited by successfully removing acid red dye 66 (AR66) from a solution composed of water. To optimize the removal process, Central Composite Design (CCD) was applied to investigate the impact of four main parameters: solution pH, initial dye concentration, adsorbent mass, and contact time. The generated CCD database was modeled using Gaussian process regression (GPR) with the Lévy flight distribution (LFD) optimization algorithm. The GPR model was then used to determine optimal conditions for maximum AR66 absorption (3405.3 mg/g), with a pH of 2, initial dye concentration of 1000 mg/L, adsorbent mass of 0.2 g/L, and contact time of 11 minutes. Furthermore, the GPR model exhibited significantly lower error (32.58 mg/g) in predicting the experimental values compared to the CCD model (204.92 mg/g), highlighting the efficiency and superiority of the GPR model in this study