Static mixers are devices equipped with a series of identical internal elements designed to promote or enhance mixing. They are widely used in pipes, channels, columns, and reactors, playing a key role in process intensification by offering advantages such as reduced space requirements, shorter residence times, and lower operatiing costs. Since the first patent was filed in 1874, numerous designs have been developed and commercialized. One of the most critical parameters in selecting a static mixer is its energy consumption, typically characterized by the pressure drop it induces. While engineering handbooks provide a broad range of empirical correlations for predicting the pressure drop across various mixer types under both laminar and turbulent flow conditions, studies specifically focusing on Komax static mixers (manufactured by Komax Systems Inc., Huntington Beach, California, USA) under a turbulent flow remain limited.

This study aims to address this gap through a dedicated experimental investigation conducted in a horizontal pipe (ID = 40 mm, length = 14 m), using water as the working fluid. The static mixers were positioned 5.8 m downstream from the pipe inlet. A key novelty of this work lies in the quantification of the effect of the number of Komax mixing elements (two, three, and four) on the resulting pressure drop. Analysis of the experimental data shows that increasing the number of elements leads to a reduction in the Darcy friction factor. A new correlation is proposed to predict this parameter as a function of the number of elements, showing good predictive capabilities, with an average relative error and an absolute relative error of less than ±10% and ±20%, respectively. The results obtained for the friction factor are also compared with available data from the literature for other types of static mixers. In addition, the power dissipated per unit mass of liquid is analyzed and discussed.

Despite the growing interest in phytoecdysteroids due to their valuable biological effects, there remains a notable gap in accessible methodologies for their reliable identification and quantification in plant-derived products. Among these compounds, ecdysterone has attracted substantial attention owing to its broad pharmacological activity and proposed performance-enhancing effects. Similarly, turkesterone has emerged as a promising candidate within the domain of sports supplementation, given its hypothesized anabolic potential. This study aimed to develop and validate a robust liquid chromatography–mass spectrometry (LC–MS) method for the qualitative and quantitative analysis of ecdysterone and turkesterone. Method optimization focused on ionization efficiency and chromatographic resolution using a mobile phase of 0.1% formic acid in water and acetonitrile. An analysis was conducted in both total ion chromatogram and selected ion monitoring modes for accurate detection and quantification. The method was systematically optimized to ensure high selectivity, sensitivity, and reproducibility while maintaining cost-effectiveness to support its implementation in routine phytochemical screening and quality control applications. The validation results confirmed the method’s analytical reliability, demonstrating excellent linearity, accuracy, precision, and detection limits. The practical applicability of the method was further established through the analysis of plant extracts. Among the evaluated plant extracts, kaniwa exhibited the highest concentration of ecdysterone, followed by spinach, quinoa, and asparagus. These findings emphasize the nutritional value of select plant-based foods as natural sources of phytoecdysteroids and demonstrate the utility of the developed LC–MS method for quality control in sports supplements and natural product research.

Biofabrication of ZnO and MgO Nanoparticles Using Dracaena trifasciata-Derived Reducing Agents and Their Antimicrobial Activity Against Pathogens

Sheetal Rajpoot¹, Shivani¹, Aparna Sharma¹, Akanksha Yadav¹, Swati Sharma², Shefali Singh² and Shashi Bala¹*

¹Department of Chemistry, University of Lucknow, India

²Department of Chemistry, Integral University, Lucknow, India

Email: shashichem15@gmail.com

Various plant-mediated nanoparticles have been used as drugs due to their antimicrobial activity because they are active against various pathogens like bacteria, fungi, etc. ZnO and MgO are emerging as promising antimicrobial agents. Biofabricated nanoparticles were synthesized with Dracaena trifasciata, characterized using a field emission scanning electron microscopic (FE-SEM) analysis depicting the spherical shape of the NPs, and an energy-dispersive X-ray (EDAX) analysis confirmed the presence of oxygen and zinc in the synthesized NPs. XRD (X-ray diffraction) patterns were recorded to measure the size and phase of the NPs. The MgO nanoparticles have particle size distributions lower than 11.5 nm. The agar well diffusion method was used to assess the antibacterial activity of samples SRNP-1, SRNP-2, and SRNP-3 against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial strains. Among the isolates, SRNP-1 showed the highest activity against Escherichia coli, with an inhibition zone of 30.33 ± 0.58 mm at 100 µg/mL, comparable to the standard antibiotic gentamycin (30.67 ± 0.58 mm). SRNP-2 and SRNP-3 also displayed activity, with inhibition zones of 26.67 ± 2.31 mm and 24.33 ± 0.58 mm, respectively, at 100 µg/mL. Nanoparticles of ZNO and MgO can significantly improve food packaging materials by enhancing their mechanical strength, barrier properties, and antimicrobial activity, ultimately extending shelf life and improving food safety.

Xanthene-1,8-dione derivatives are of significant interest in pharmacology and materials chemistry due to their biological and optical properties. However, their traditional synthesis often involves toxic catalysts or environmentally harmful solvents. We propose a novel eco-friendly approach for synthesizing these compounds using green reaction conditions, avoiding hazardous organic solvents and minimizing unwanted byproducts.

The synthesis is carried out via condensation between dimedone and various aldehydes in the presence of linear alkylbenzene sulfonic acid (LABSA) as a biodegradable and cost-effective phase-transfer catalyst and under alternative activation methods such as ultrasound irradiation. The reaction is optimized to maximize yield while reducing environmental impact. LABSA, functioning both as a Brønsted acid and surfactant, is proposed to facilitate a multicomponent cascade process involving Knoevenagel condensation, Michael addition, and intramolecular cyclization

Xanthene-1,8-dione derivatives are obtained in high yields (88%-90%) with excellent purity. The method offers significant advantages, including reduced reaction time, atom economy, and easy purification. The products are characterized by spectroscopy (NMR, IR, MS) and chromatographic analysis. In IR strong carbonyl stretching bands observed near ~1623–1634 cm⁻¹ are characteristic of two conjugated carbonyl groups at positions 1 and 8 of the xanthene core.

This green strategy provides a sustainable alternative to conventional protocols, aligning with the principles of green chemistry. It opens new possibilities for the eco-friendly synthesis of heterocycles valuable in pharmaceuticals and fine chemistry.

Environmental pollution poses a significant global challenge. This work details the synthesis and characterization of polyaniline (PANI) and titanium dioxide (TiO2) composite materials for their application in catalytic environmental remediation. The integration of PANI, a conductive polymer, with TiO2 was aimed at enhancing the efficiency and broadening the applicability of TiO2 in degrading various environmental pollutants. This work employed the approach of mechanochemical mixing of pre-synthesized PANI and TiO2. The choice of synthesis method was critical to determine the surface area, porosity, and the degree of PANI encapsulation of TiO2 particles. Composites are multifaceted, employing a range of analytical techniques. X-ray Diffraction (XRD) was used to confirm the crystalline phases of PANI/TiO2. Pure polyaniline (PANI) has a 2theta value of 21.1(3), and after TiO2 was incorporated into polyaniline, there was a shift from 21.1 degrees for PANI to 27.05 degrees for PANI-TiO2, indicating an interaction between TiO2 and polyaniline that alters their respective crystalline structures. Fourier Transform Infrared (FTIR) spectroscopy provided insights into the chemical interactions within the composite. The presence of N-H, O-H, and C=N peaks confirms that both materials retain their essential chemical identities. Scanning Electron Microscopy (SEM) image of pure PANI revealed a fibrous structure, characterized by elongated fibers. TiO2 particles were observed to be uniformly distributed within the PANI matrix. This distribution leads to a more compact structure compared to pure PANI, as TiO2 particles fill in gaps between PANI chains, reducing porosity while increasing overall surface area. The synergistic effect between PANI and TiO2 improved visible light absorption and efficient charge separation, overcoming the limitations of pure TiO2. This research highlights the potential of PANI/TiO2 composites as effective and sustainable photocatalysts for the degradation of organic pollutants in wastewater. Photocatalysis, utilizing semiconductor materials, offers a promising and sustainable approach for the degradation of pollutants into less harmful substances.

Septic tank sludge, rich in organic content, presents a valuable opportunity for renewable energy generation through anaerobic digestion. This study explores its potential for biomethane production by developing and optimizing a bioconversion system. Extensive experimental work began with the physicochemical characterization of the sludge, including proximate and ultimate analyses, which revealed a high heating value (HHV) of 14.324 MJ/kg and favorable elemental composition for energy recovery. Batch anaerobic digestion experiments were conducted under controlled conditions to assess system performance, with pH, volatile fatty acids (VFA), and total ammonia nitrogen (TAN) maintained within optimal ranges to ensure process stability. Simulation and process modeling were carried out using Aspen Plus, and the model was validated against experimental methane yield data, achieving an excellent fit (R² = 0.9917). Key operational parameters, including temperature, hydraulic retention time (HRT), and organic loading rate (OLR) were optimized using Response Surface Methodology (RSM). The analysis identified that a hydrolysis temperature of 35 °C, a digestion temperature of 60 °C, HRT of 35 days, and OLR of 37.907 L¹day¹ produced the highest biomethane output at 99.98%, with up to 96.67% degradation efficiency. These findings confirm that precise control and optimization of digestion conditions can significantly enhance biogas yield from septic tank sludge. The validated model and experimental insights contribute to the development of sustainable waste-to-energy solutions, offering a practical approach to mitigating environmental and public health challenges posed by improper sludge disposal.

Heap leaching is an economically viable hydrometallurgical technique extensively employed in the mining industry for extracting valuable metals such as copper from low-grade ore deposits. This method renders a cost-effective solution for processing ore that would otherwise be considered uneconomical for conventional extraction techniques. This study investigates the efficiency of copper recovery from different particle size fractions of low-grade oxide ores that have undergone crushing stage. Hydrochloric acid was used as a lixiviant in column heap leaching experiments to study the effect of particle size on copper extraction recovery. The experiments were conducted using column leach setups with dimensions of 150 mm in diameter and 2 meters in height. Crushed ore samples, ranging in particle size from 25 mm down to 1.8 mm, were divided into 5 kg aliquots and loaded into the columns, with a total mass of approximately 40 kg per test. Leaching was performed over a period of 16 days using an acid concentration of 200 g/L. The results demonstrated promising copper recoveries. One sample achieved a copper extraction rate of 75% within 16 days, with maximum acid consumption reaching 23 kg/ton over 15 days. Another sample yielded a comparable copper recovery of 74% under the same timeframe but required a higher acid consumption rate of 30 kg/ton. Moreover, the consistent linear increase in copper recovery throughout the leaching period suggests minimal interference from pregnant solution robbing impurities in the ore that consumes the lixiviant.

Today, hydrophobic eutectic solvents are promising extractants for metal ions. Their main advantage is the "adjustability" of their physicochemical and extraction properties due to a wide range of compounds suitable for preparation. In this study, eutectic solvents based on octanoic acid and aliphatic alcohols (1-decanol, 1,9-nonanediol, geraniol, linalool) will be investigated for the extraction of Fe(III) ions, which are often present in various mixtures, such as wastewater, leaching solutions of lithium iron phosphate batteries, etc. The octanoic acid/alcohol ratio in eutectic solvents was 1/1. The ratio of aqueous and organic phases during extraction was also 1/1. The Fe(III) distribution coefficient was calculated as the ratio of the equilibrium concentration of Fe(III) ions in the eutectic solvent phase to the equilibrium concentration of Fe(III) ions in the aqueous phase. It was found that with an increase in the pH of the initial solution from 1.4 to 2.4, the Fe(III) distribution coefficient increased. In addition, the extraction efficiency depends on the aliphatic alcohol and increases in the following series: linalool, 1,9-nonanediol, geraniol, 1-decanol. The distribution coefficients at pH 2 were 0.95, 1.36, 1.69, 2.07, respectively. The results indicate that the structure of the aliphatic alcohol affects the extraction capacity of octanoic acid. The reason for this may be multiple hydrogen bonds and Van der Waals interactions between the components, which may hinder the extraction of Fe(III) ions due to steric hindrance. For example, linalool is a tertiary alcohol, which may be the reason for the formation of multiple interactions between the components of the eutectic solvent and, as a result, the reason for the lowest extraction capacity.

Azeotropic mixtures such as acetone–chloroform present considerable challenges to conventional separation methods due to their constant boiling behavior, which limits the effectiveness of ordinary distillation techniques. Overcoming these limitations often requires the use of entrainers to break the azeotrope and enhance component separation. However, understanding the interplay between temperature, entrainer type, and the quantity introduced remains a key challenge in optimizing separation performance. This study investigates the flash distillation of an acetone–chloroform binary azeotrope using process modeling and simulation to evaluate how operating temperature and entrainer concentration (introduced via flow rate) affect the separation efficiency. Two entrainers were assessed—water and a secondary organic compound—with simulations conducted across varying temperatures and entrainer dosages. The results reveal that temperature changes have a greater impact on separation efficiency when an entrainer is present, with higher entrainer concentrations significantly enhancing phase separation and making the system less sensitive to temperature fluctuations. Among the entrainers examined, water consistently outperformed the alternative by improving the ease and extent of separation. These findings highlight the critical role of entrainer selection and dosing strategy in azeotropic separation via flash distillation. The insights gained offer a practical basis for improving process design, reducing energy demand, and enhancing product purity in both industrial and research applications. The modeling approach also provides a cost-effective tool for screening and optimizing separation strategies for similar complex mixtures.

This study presents a comprehensive investigation of the uniaxial tensile behavior of graphene-reinforced nickel nanocomposites (Gr/Ni) using molecular dynamics (MD) simulations. Two distinct reinforcement architectures were examined: (1) a monolayer graphene sheet embedded within the nickel matrix (denoted NiGr[−], ~0.66 vol%) and (2) a cross-shaped graphene network (denoted NiGr[×], ~1.0 vol%). The mechanical response was evaluated under uniaxial tensile loading along the z-axis, considering three crystallographic interface orientations between graphene and nickel: (100), (110), and (111).

The incorporation of graphene significantly enhances the mechanical performance of the nickel matrix, particularly in terms of stiffness, strength, and ductility. Specifically, the Young’s modulus increased by approximately 123% in the NiGr[−] configuration, while the NiGr[×] network further improved stiffness by 135%, 154%, and 143% for the (100), (110), and (111) orientations, respectively. Similarly, the ultimate tensile strength (UTS) increased by 0.47 GPa, 3.61 GPa, and 4.97 GPa in the NiGr[−] system and by 1.84 GPa, 6.24 GPa, and 10.62 GPa in the NiGr[×] system for the same orientations.

The analysis revealed that the NiGr[×] configuration, particularly in the (110) and (111) orientations, exhibits the most pronounced reinforcement effects. Dislocation density mapping during deformation demonstrated that graphene acts as an effective barrier to dislocation propagation. Remarkably, the NiGr[×] structure enabled the composite to sustain a strain level exceeding that of pure nickel by more than five times before failure.

These findings highlight the superior load-bearing capacity and enhanced structural integrity of Gr/Ni nanocomposites, with the cross-shaped graphene network offering exceptional mechanical advantages. The results suggest significant potential for such architectures in advanced engineering applications, particularly in industries requiring high-performance structural materials.