Precision polishing is difficult for advanced materials like silicon carbide and boron carbide. Magnetic abrasive flow machining (MAFM) has become an effective method for cleaning, deburring, and polishing metal and high-tech engineering parts. By finishing hybrid Al/SiC/B4C-metal matrix composites (MMCs), this research uses MAFM for experimental readings. The present work is innovative due to the aluminum workpiece fixture, hybrid composites, and response surface methodology (RSM) modeling. The neural simulation of the MAFM process and nature-inspired error reduction make it unique. Using six input and two output parameters, a generic framework is created. Box-Behnken design (BBD) of response surface methodology plans and executes 54 runs of experimentation. The hybrid artificial neural network (ANN) technique is used to compare the MAFM process systematically. ANN is used to model parameter input-output relations. To anticipate the created surface accurately, regression models must be precise. These hybrid particle swarm optimization (PSO)-genetic algorithm (GA)-simulated annealing (SA) algorithms optimize the MAFM process. Additionally, trained ANN models outperform the BBD model in prediction. For optimal error reduction, the neural network uses Bayesian regularization with 112 iterations. The ANN model regression graph shows a correlation between inputs and outputs. A scanning electron microscope (SEM) with 300-magnification examines the workpiece surface. According to SEM, MAFM provides fine surface textures, thus reducing abnormalities.

This study investigates the crystallization and self-assembly phenomena of polyacrylamide (PAM) solutions during evaporation. While traditional thin-film fabrication methods such as spin coating and drop casting are commonly used, this study utilizes a simple evaporation approach to gain insights into the self-assembly processes of PAM solutions. We examined PAM solutions with varying concentrations (1%, 2%, and 5%) and observed the resulting crystalline structures and morphological changes during evaporation. Spectroscopic absorbance measurements were employed to analyze concentration gradients and crystallization patterns. The findings reveal that the concentration gradient during evaporation significantly impacts the crystallization behavior of PAM solutions. The 2% solution exhibited the clearest and most regular crystalline patterns, whereas the 1% and 5% solutions displayed more complex and irregular morphologies. These observations provide new insights into how solution concentration influences PAM crystallization, contributing to a better understanding of polymer thin-film self-assembly. The novelty of this study lies in exploring PAM self-assembly through controlled evaporation, offering valuable insights for the development of polymer films.

Sulfuric acid (H2SO4) has a wide range of applications, but its current synthesis route via the contact process negatively impacts the atmospheric environment with harmful gaseous pollutants. Thus, based on the non-random two-liquids (NRTL) thermodynamic method, this study presents a detailed Aspen Plus V8.8 simulation of the green synthesis route of H2SO4 based on Geber's method developed already in the 18th century. The research investigates the efficiency and energy dynamics of the process through the analysis of key process parameters such as reactor's heat duty, vapor fraction, and molar extent of reaction in the selected configuration, using green vitriol (FeSO4∙7H2O) as a natural raw material. This study presented a novel manufacturing route that resulted in H2SO4 of 85.76% purity (33.71 kg/h), considering the chosen parameter space. The results highlight the impact of reactant component molar yield and fractional conversion of iron (II) sulfate (FeSO4) on heat duty and the optimal molar extent for maximizing H2SO4 production in a series of equilibrium reactors. In addition, appropriate operational parameters for the synthesis process were carefully specified, offering a pathway towards sustainable and eco-friendly H2SO4 production, which should emit zero greenhouse gases. Further optimization of the reactor conditions, can help maximize the yield of H2SO4, while minimizing energy consumption and byproduct formation. Developing advanced wastewater treatment units to purify the wastewater stream containing trace amounts of H2SO4 and dissolved sulfur trioxide (SO3) can mitigate environmental impact and ensure compliance with regulatory standards.

Over the last fifteen years, immense progress has been made in the research of pressure-swing batch distillation. The challenge lies in the fact that certain pressure-sensitive azeotropic mixtures cannot be separated in a regular open batch mode with an acceptable outcome. Throughout most of this text, findings contradict previously established facts. The separation of acetone-methanol by pressure-swing batch distillation in a mixed double system, consisting of a regular and inverted column, is the process under investigation. In this work, a comprehensive global solution to the optimal control problem is derived in the form of a sequential synthesis of controlled trajectories. A thorough analysis of the control variables, with and without parametric sensitivity of manipulated variables, on the optimal control pattern with variable reflux is presented. Most authors did not achieve significant results by simultaneously optimizing reflux and liquid division ratios or by using a "variable pressure gap." This study challenges previous findings, emphasizing the importance of simultaneous optimization of all three factors mentioned. During this study, the optimal reflux strategy through cyclic operation was extended to optimize energy expenditure over a fixed time horizon. Moreover, the proposed scheme offers a high level of operational flexibility, allowing units to be operated independently or as a system. Additionally, the facility of connecting additional devices is highlighted by the significant difference in output temperatures and the potential for using evaporated fluids consecutively. Lastly, the research provides a solid basis for future investigations into internal and external heat integration, potentially leading to conclusions about expanding the network using well-known heat cycles.

Bagasse is the sugar cane residue obtained from the sugar industry. It is produced in large quantities and used to make paper because of its fibrous structure. In the present research, sugarcane bagasse (SCB) was chemically treated with HNO3, NaOH, and a bleaching agent to recover 58% of the chemically purified cellulose (CPC), which was subsequently hydrolyzed with H2SO4 to form cellulose nanocrystal (CNC). The capacity of a composite membrane made of cellulose nanocrystal (CNC) enhanced with silver nanoparticles (Ag NPs) to extract phenols from petrochemical effluent was examined. The prepared membrane was examined using a scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results showed that the white spot on the crystal surface suggested AgNP agglomeration on the CNC surface. The nanocellulose possessed crystallinity indices ranging from 21.9 to 33.1 nm, whereas the silver particles measured 23 and 62 nm. The high separation result of phenol obtained at casting composition of 14% Ag NPs reached 60% at an equilibrium time of 45 min and pH 9. The isothermal and kinetic analysis explained that the rate of adsorption process is the pseudo-second order and followed the Frendlich isotherm models. The CNCs generated using this approach were found to be less agglomerated and more crystalline, indicating a better potential as bio-nanocomposite materials for wastewater treatment.

Silver nanoparticles (AgNPs) have been the subject of researchers due to their unique properties such as optical, antimicrobial, and electrical properties depending on size and shape. This review focuses on their green synthesis of nanoparticles, metal nanoparticles and mainly AgNPs. Green chemistry synthesis method has attracted great attention as an alternative method in recent years because it is more energy efficient, safer and less toxic. At the same time, this study gives a general idea about the preparation of AgNPs by green synthesis method using lignocellulosic biomass. One of the main uses of lignocellulosic wastes in a circular economy is to introduce renewable resources into the market and on the other hand, to promote the valorization of waste. Moreover, lignocellulosic raw materials expand the sustainability possibilities of industrial processes as a result of their low cost and low environmental impact. On the other hand, dyes, which are wastes from different industries such as textile, plastic, food and paper, are the main cause of water pollution. This study provides a detailed investigation of the removal performance of AgNPs obtained using different lignocellulosic biomass for environmentally harmful cationic dyes.

Waste disposal sites contribute a great deal to environmental pollution. The degree of pollution brought on by heavy metal contamination of soil collected from the Oti-Dompoase dump site in Kumasi of Ashanti region, Ghana was investigated in this study. Twelve (12) composite samples of the surface soil were taken in total at 10 cm depth from the dumpsite to conduct metal analysis. The measurement of heavy metal concentration was done utilizing Atomic Absorption Spectrometer, which uses the absorbance at various wavelength of the electromagnetic spectrum to determine the chemical identity of constituents of the sample and their concentrations with the help of standard solutions and Beer-Lambert law. The mean metal concentrations of soil samples were reported and arranged in terms of magnitude as follows: Iron (2,582.21 mg/kg) > Copper (348.50 mg/kg) > Lead (324.85 mg/kg) > Manganese (192.27 mg/kg) > Zinc (146.24 mg/kg) > Cadmium (7.06 mg/kg). Physiochemical properties such as electrical conductivity (EC), pH and organic matter and water content (%) were also investigated using a PHYWE electrical conductivity meter, pH meter and an oven, respectively. Most of the parameters analysed indicated pollution when compared to baseline values, while human exposure levels were within World Health Organization (WHO) standards. Assessments using geo-statistics of different hazard indicators, including pollution load index, contamination factor (CF), and geo-accumulation, all point to heavy metal pollution of the soil samples. Cadmium contamination was very high based on the pollution indices (CF, geo-accumulation, and pollution load) and manganese has the lowest level of pollution. There is limited data on the extent of pollution caused by the Oti-Dompoase dumpsite and this study will serve to fill this knowledge gap and contribute to the Millenium Development Goal seven (7) by providing data on the extent of pollution of soil around the Oti-Dompoase dumpsite and highlight the need for regular monitoring and on-site remediation strategies to safeguard the site to ensure environmental sustainability.

We present a novel self-organized chemical "living" system that mimics natural photosynthesis by capturing CO2 and H2O from the atmosphere at ambient conditions. This system autonomously reduces CO2 with H2O protons to produce long-chain aliphatic oxygenated products. Starting with 2-phenyl indole (PI) complexes with TiCl4, the hydrolyzed complexes react with CO2 to form organotitanium carbonates. The 2:1 PI/TiCl4 complex was found to be the most effective. Key findings include: Photocatalytic Reduction: Visible light reduces TiIV to TiIII and TiII, forming peroxotitanium complexes and releasing OH radicals. CO2 Reduction: CO2 is reduced to CO, H2CO, and CH3OH, which couple to form HOCH2CH2OH. Organic Compound Synthesis: The system generates oxygenated organic compounds with carbon chains from C2 to C16. Ligand Exchange: The PI ligand exchanges with donor molecules, forming adducts involved in the photocatalytic process. PI Oligomerization: Contributes to the formation of PI oligomers. These processes were monitored using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) spectra, proton and Carbon-13 nuclear magnetic resonance (13C NMR), and infrared (IR) spectra, identifying over two dozen intermediates and products. This system offers a prototype for new applications with potential improvements using other metals and ligands.

Senegalia nigrescens has been used in traditional Swazi medicine. S. nigrescens is used in the treatment of wounds, toothache, diabetes, dysentery, snake bites, convulsions and skin diseases. In this study, we aimed to evaluate the antioxidant potential, determine the half-minimal inhibition concentration (IC50) values and analyze phytochemical constituents of various solvent extracts obtained from the leaves and stem-bark of S. nigrescens. The maceration technique together with the hot solvent extraction approach was used for the obtainment of various solvent extracts. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging potential, IC50 values and phytochemical analysis were performed as per established procedures. The radical scavenging potential of extracts from leaves and stem-bark of S. nigrescens and positive control (ascorbic acid) were found to be in the ranges of 7.55 ± 0.004 ~ 62.19 ± 0.004%, 9.04 ± 0.003 ~ 63.24 ± 0.006% and 50.98 ± 0.002 ~ 71.0 ± 0.007%, respectively at a concentration range of 200 ~ 3,000 μg/mL. The methanol extracts from the leaves, stem-bark and positive control exhibited IC50 values of 921.69, 735.74 and < 200 μg/mL, respectively. Several classes of phytochemicals were identified in these extracts which include alkaloids, steroids, terpenoids, flavonoids, phenolics and tannins. We concluded that S. nigrescens showed a weak to moderate DPPH radical scavenging potential and possessed various classes of phytochemicals.