SAID SHEHATA

Nanozymes engineered to mimic natural enzyme catalysis have emerged as promising alternatives due to their enhanced stability, cost-effectiveness, and tunable catalytic properties compared to biological enzymes. Developing nanozymes with well-defined porous structures and heteroatom doping is key to improving catalytic efficiency and selectivity particularly for applications in biosensing. Nanotechnology has become a key enabler in advancing catalysis, biosensing, and environmental monitoring thanks to the exceptional properties of nanomaterials such as large surface area, customizable optical characteristics, and enhanced catalytic activity. In this study, a novel nanozyme platform based on creatinine–thiourea–FeCl3 nanoparticles (CTF-NPs) was developed via a one-step pyrolysis method using colloidal silica as a porosity template. The synthesized CTF-NPs were uniformly structured as confirmed by SEM, EDX, FT-IR, UV–Vis, and XRD and featured effective nitrogen, sulfur, and iron doping contributing to their catalytic efficiency. The CTF-NPs exhibited strong peroxidase-like activity catalyzing the colorimetric oxidation of o-phenylenediamine (OPD) in the presence of hydrogen peroxide (H2O2). Kinetic studies revealed a Km of 0.819 mM and a Vmax of 1.620 μM/min outperforming several previously reported nanozyme systems. The sensor displayed a linear detection range of 10–700 μM for H2O2 with an excellent correlation coefficient (r= 0.9975) optimal at pH 4, 40 °C, and 10-minute incubation. Upon coupling with glucose oxidase (GOx), the platform enabled indirect glucose detection via enzymatically generated H2O2 showing a linear range of 100–600 μM with a correlation coefficient of r= 0.9953. The system exhibited high selectivity against common interferents, reproducible fabrication, and reliable performance in spiked human serum samples. Integration of the nanozyme system with a portable RGB color sensor (TCS34725) enabled quantitative, user-friendly, and instrument-free detection supporting the development of accessible point-of-care diagnostics. This work introduces a scalable and robust platform for glucose monitoring with promising implications for diabetes management and decentralized healthcare.

Stream channels are dynamic systems that continuously adjust their morphology through lateral and vertical erosion, particularly during high-intensity, infrequent rainfall events. In arid regions, such changes can have significant implications for river management and infrastructure safety. This study investigates stream migration processes along the Red Sea coastal segment between Ain El-Sokhna and Ras Shukair, Egypt, by employing high-resolution satellite imagery, in situ field measurements, and discharge data to capture detailed hydrological and sediment characteristics. An integrated methodology combining hydrological modeling using HEC-RAS 2D, GIS-based spatial analysis, and sediment transport simulation was implemented to quantify channel movement and assess potential scour locations. Quantitative results reveal lateral stream shifts ranging from 50 to 250 m, with a statistically significant correlation between predicted scour areas and zones of elevated shear stress, underscoring the pivotal role of sediment transport. The novelty of this approach lies in the development of a simplified hazard assessment technique that integrates critical parameters such as ground slope, stream discharge, and soil type into a unified spatial framework, this method significantly reduces computational time and data requirements compared to traditional fully hydraulic models while still producing reliable and comparable results. Moreover, unlike most studies that focus on stream migration in wet valleys, this investigation examines the phenomenon in dry streams, addressing a critical gap in the literature. Consequently, the approach offers a practical tool for engineers and urban planners engaged in sustainable river management, flood risk assessment, and infrastructure protection under evolving climate conditions.

Heavy metal pollution poses risks to terrestrial food chains. We evaluated biochemical and cellular responses of fifth-instar Agrotis ipsilon (black cutworm) fed castor (Ricinus communis) leaves collected from two polluted sites and a reference site.

The present study evaluates the synthesis, geochemical and mineralogical characterization, as well as the industrial and environmental applications of zeolites synthesized from kaolin and bentonite resources in selected clay deposits of Northeast Africa, Egypt. Several methods were employed to synthesize zeolites from both kaolin and bentonite samples to obtain high purity zeolitic products at a competitive cost. The characterization of the synthesized zeolites, in terms of mineralogy and geochemistry, was conducted using various techniques, including X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and cation exchange capacity (CEC). Additionally, thermo-analytical methods such as thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used. Based on the characterization of zeolites synthesized from bentonite and kaolin, a comparison was made with ideal zeolites used in various industries to determine their potential applications. The synthesized zeolites were evaluated for their effectiveness as adsorbents for H2S in wastewater and fuel gas purification. Additionally, they were assessed for their ability to remove ions such as Co2+, Sr2+, and Cs+ from aqueous solutions containing organic and suspended solids. Furthermore, these zeolites were investigated for their potential use as commercial and sustainable catalysts for controlling nitrogen oxide (NOx) emissions from diesel engines in vehicles.

Diesel engines are essential in sectors such as transportation, agriculture, and power generation, offering benefits like fuel efficiency, high power output, and durability. However, their emissions (NOX, CO2, CO, HC, SO2, and PM) significantly contribute to air pollution, posing serious environmental and health risks. This study aimed to design and fabricate a unit that simulates diesel engine emissions and tests various purification materials. The unit consists of a combustion chamber, filtration media, and exhaust pipes, with materials such as activated carbon, activated carbon with magnesium oxide, and Ni-Carbon Nanotube (CNTs) nanocomposites tested under controlled combustion conditions to measure their pollutant removal efficiencies. Results showed that 100% activated carbon achieved pollutant removal efficiencies of 85.21% for CO2, 80.77% for CO, and 68.84% for HC. Combining activated carbon with magnesium oxide (AC: MgO) enhanced these efficiencies to 76.92% for CO2, 86.84% for CO, and 73.28% for HC. Ni-CNTs nanocomposites (at 0.2 concentration) demonstrated the highest performance, with removal efficiencies of 93.13% for CO2, 94.87% for CO, and 76.02% for HC. These results emphasize the potential of Ni-CNTs nanocomposites as highly efficient materials for reducing diesel exhaust emissions, contributing significantly to cleaner air, better public health, and more sustainable diesel technologies.

The rising usage of power electronic converters linked to renewable energy sources has become a major source of harmonics in power systems. Passive harmonic filters are an excellent solution for addressing this issue. However, these traditional filters have a problem linked to resonance frequency, which needs damping. This paper introduces a Harmonic Blocking Filter (HBF) that consists of a shunt-connected Damped Double-Tuned Passive Filter (DDTF) and a series component. Six different DDTF schemes are investigated: four single-resistor DDTFs (SR-DDTF) and two double-resistor DDTFs (DR-DDTF). This study intends to perform harmonic mitigation and increase PV penetration levels by obtaining parameters for each HBF system using the Autism-Based Optimizer (ABO). The Harmonic Pollution Factor (HPF) is a power quality indicator used to assess and reduce the system’s harmonic content. The findings show that the proposed HBF filter efficiently increases PV penetration in the system while lowering harmonic levels.

This study aims to valorize hazardous industrial marble machining and shaping waste powder as a precursor to prepare a heterogeneous nano-catalyst (CaO/K2CO3) employing the wet-impregnation method for producing biodiesel via the transesterification of waste cooking oil (WCO). Surface and morphological characterization of the thus-prepared nano-catalyst has been performed employing various analytical tools, e.g., XRD, BET, CO2-TPD, FT-IR, HR-TEM, and FE-SEM & mapping EDX. The impact of calcination treatment on the catalytic performance is investigated together with the weight percentage (wt%) of CaO compared to K2CO3. Response surface methodology (RSM) is used to optimize the parametric independent variables, e.g., catalyst loading level, reaction temperature, and time, as well as methanol to WCO molar ratio (M : WCO) via the central composite design (CCD). The experimentally attained optimal reaction parameters for effective biodiesel production (92%) are: 3.2 wt% catalyst loading, operating at 40 °C for 84 min, along with a 5.8 : 1 M : WCO. The proposed nano-catalyst has been recovered and reused effectively for 5 consecutive cycles, with a slight loss in catalytic activity beginning from the 3rd cycle. Additionally, the quality of the obtained biodiesel perfectly fits the American (ASTM D-6751) and the European (EN-14214) standard limits.

Cardamom seed (Elettaria cardamomum (L.)) is a well-appreciated spice in food and pharmaceutical industries owing to its unique rich flavor dominated by oxygenated monoterpenoids, α-terpinyl acetate and 1,8-cineole, to which most of the quality of cardamom essential oil (CEO) is attributed. CEO output is greatly influenced by different agronomic factors, processing, and EO extraction methods. In that context, the goal of this study is to provide an overarching review regarding emerged technologies along with their optimization parameters to achieve optimal oil yield with the best flavor quality. Furthermore, the recent approaches employed in CEO stabilization were highlighted alongside their pharmaceutical and food applications. Moreover, the different aspects of superlative CEO production including agricultural aspects, climatic requirements, and processing methods were also explained.

Laccases enzymes have garnered significant research interest owing to their extensive applications in pollutant degradation, the food industry, and biosensing technologies. These green biocatalysts are distinguished by the presence of four copper active sites which are integral to their enzymatic functions. Recent advancements have led to the development of copper-based organic–inorganic nanocomposites as laccase mimetics. Hence, this study focused on the synthesis and study of the catalytic properties of a copper–gallic acid metal–organic framework (Cu–GA MOF) heterostructure as a laccase mimic. Using o-phenylenediamine (OPD) and norepinephrine as model substrates it was observed that the synthesized Cu–GA MOF exhibited a laccase-like catalytic performance. Similar to natural enzymes and other nanozymes, Cu–GA MOF demonstrated pH-dependent catalytic activity demonstrating an optimal performance under physiological conditions. It exhibited a superior Michaelis constant (Km) of 0.06 mM, maximum reaction rate (Vmax) of 4.1 × 10−3 mM min−1 and superior recyclability compared with laccase at the same mass concentration. Remarkably, Cu–GA MOF displayed exceptional thermal tolerance maintaining substantial catalytic activity at temperatures up to 90 °C. In contrast to natural enzymes, Cu–GA MOF exhibited enhanced stability and recyclability underscoring its potential for diverse bio-applications. These findings highlight the promising role of Cu–GA MOF as a robust and versatile catalyst in biocatalytic and analytical applications.