Strong asymptotic stability for a coupled system of degenerate wave equations with only one fractional feedback

This research work is supported by the General Direction of Scientific Research and Technological Development (DGRSDT), Algeria.We prove the well-posedness and study the strong asymptotic stability of a coupled system of degenerate wave equations with a fractional feedback acting on one end only.Publisher's Versiio

Liquid Phase Hydrogenation of MIBK over M/CsPW (M = Ag, Ru, Pt, and Pd)

Four different metal nanoparticles (metal = Ag, Ru, Pt, or Rh) were impregnated on the acidic cesium salt of tungstophosphoric acid Cs2.5H0.5PW12O40 (CsPW) with a loading amount of 2 wt%. The prepared catalysts were characterized by using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), N2 sorption measurements, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Results confirmed the formation of highly distributed metallic nanoparticle centres over the acidic CsPW. The catalytic activity of the prepared catalysts were evaluated in the liquid phase hydrogenation of methyl isobutyl ketone (MIBK) to 2-methylpentane (2-MP) at 453 K. Pd-CsPW showed the highest activity compared to other catalysts, where 10% conversion was obtained with 91% selectivity after 4 h’s reaction time

Simulating two Algerian cities' desalination plants coupled with solar energy systems using TRNSYS

Our study aimed to design a prototype for a desalination unit coupled with a solar collector, utilizing TRNSYS 16, to address the needs of both Bouzaréah in northern Algeria and Ghardaïa in southern Algeria. The desalination unit is composed of vacuum membrane distillation (VMD) coupled with a solar collector, and the photovoltaic has been designed according to the climatic conditions of each region. In this work, the approach adopted is to integrate a model developed in the literature into a simulation environment (TRNSYS) coupled with the CODE-BLOCKS compiler and FORTRAN programming language to create a new component (i.e., VMD process). Simulation results showed that the optimum permeation flux obtained through the desalination unit is relatively higher in Ghardaïa than in Bouzaréah, with a flow exceeding 30 kg/h.m2. The permeation flux and the power to load reached their maximum values with the charge of solar irradiation 48 kg/h.m2 and 6300 kJ/h, respectively, for Ghardaïa at the sun irradiation value 800 W/m2 and temperature of 34 °C. Results showed that Ghardaïa had a higher GOR value than Bouzaréah over the year (10.947 vs. 8.3389). Moreover, both locations recorded thermal recovery ratio values exceeding 1, indicating the high efficiency of the desalination unit. HIGHLIGHTS A model that describes the evolution of feed temperature and permeation flux through the membrane was integrated into TRNSYS as a VMD module.; Empirical correlations were developed based on experimental results recorded at a meteorological station in two different cities.; The plant was designed to conduct annual simulations in two different cities under specific operating conditions.

Effect of Different Zeolite Supports on the Catalytic Behavior of Platinum Nanoparticles in Cyclohexene Hydrogenation Reaction

In this study, 1 wt% platinum (Pt) nanoparticles were incorporated into five types of zeolites (HY, Beta, mordenite, ZSM-5, and ferrierite) with an impregnation technique. The synthesis strategy included the use of water as a solvent for the applied Pt source. Moreover, the incorporation process was performed at ambient conditions followed by calcination at 450 °C. The five prepared materials were characterized by different physical and chemical characterization techniques and the obtained results confirmed the formation of Pt nanoparticles with an average size of 5–10 nm. The catalytic performance of the prepared materials was evaluated in the hydrogenation of cyclohexene under a solvent-free system at room temperature. Pt nanoparticles supported on ZSM-5 zeolite exhibited the best catalytic performance. Moreover, the optimization of operational conditions such as temperature, pressure, and catalyst amount was investigated and the obtained results showed the possibility to convert 100% of cyclohexene within 35 min over Pt-ZSM-5. Finally, the reusability of the Pt-ZSM-5 catalyst was investigated in four consecutive runs without treatment and the obtained results showed a negligible activity loss

Effect of Different Zeolite Supports on the Catalytic Behavior of Platinum Nanoparticles in Cyclohexene Hydrogenation Reaction

In this study, 1 wt% platinum (Pt) nanoparticles were incorporated into five types of zeolites (HY, Beta, mordenite, ZSM-5, and ferrierite) with an impregnation technique. The synthesis strategy included the use of water as a solvent for the applied Pt source. Moreover, the incorporation process was performed at ambient conditions followed by calcination at 450 °C. The five prepared materials were characterized by different physical and chemical characterization techniques and the obtained results confirmed the formation of Pt nanoparticles with an average size of 5–10 nm. The catalytic performance of the prepared materials was evaluated in the hydrogenation of cyclohexene under a solvent-free system at room temperature. Pt nanoparticles supported on ZSM-5 zeolite exhibited the best catalytic performance. Moreover, the optimization of operational conditions such as temperature, pressure, and catalyst amount was investigated and the obtained results showed the possibility to convert 100% of cyclohexene within 35 min over Pt-ZSM-5. Finally, the reusability of the Pt-ZSM-5 catalyst was investigated in four consecutive runs without treatment and the obtained results showed a negligible activity loss