Scanning Electron Microscopy Data Research Articles

Catalytic activity of Zr/CeO2-Al2O3 catalyst for diesel soot oxidation: synthesis, characterization, and performance evaluation.

Diesel soot is a significant contributor to air pollution. Soot particles present in diesel engine exhaust have a negative impact on the environment and human health. Diesel oxidation catalysts (DOCs) and diesel particulate filters (DPFs) currently use noble metal-based catalysts for soot oxidation. Due to the use of noble metals in the catalyst, the cost of diesel after-treatment systems is steadily rising. As a result, diesel vehicles have become commercially less viable than gasoline vehicles and electronic vehicles. The study focuses on an alternative diesel oxidation catalyst with efficiency similar to that of a noble metal catalyst but with a much lower cost. CeO2-Al2O3 catalysts are known for their oxygen storage capacity and high redox activity, making them suitable for soot oxidation. Adding Zr to these catalysts has been shown to influence their structural and chemical properties, significantly affecting their catalytic behavior. Therefore, the current study is focused on using Zr/CeO2-Al2O3 as a substitute for noble metal-based catalysts to enhance its performance for diesel soot oxidation in automotive exhaust. Evaporation-induced self-assembly (EISA) was used to prepare 1, 3, and 5 weight (wt) % Zr supported mesoporous CeO2-Al2O3 catalysts. Morphological, structural, and physicochemical properties of the synthesized catalysts were examined using Brunauer-Emmett-Teller (BET) absolute isotherm, Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Temperature programmed reduction (TPR), and Temperature-programmed desorption of ammonia (NH3-TPD). XRD, BET, and SEM data confirmed that the catalysts were mesoporous and low-crystalline with a high surface area. The soot oxidation activity of the catalysts was evaluated using a thermogravimetric analysis (TGA) technique. The loose contacts soot oxidation activity test suggested that 50% oxidation of soot occurred at 390°C in the absence of a catalyst. T50 of CeO2-Al2O3 catalyzed soot oxidation was 296°C. Adding Zr to the catalyst significantly improved catalytic activity for diesel soot oxidation. We observed a further drastic change in T50 of soot over 1, 3, and 5% Zr/CeO2-Al2O3, which were 220°C, 210°C, and 193°C, respectively. According to these results, incorporating Zr into the CeO2-Al2O3 catalyst significantly improved the oxidation process of soot.

Synthesis and application of fatty acid-modified chitosan for heavy metal remediation from waste water

A novel modified chitosan was synthesized using palmitic acid to selectively remove Cd(II), As(III), and Pb(II) from water samples. Chitosan was dissolved in acetic acid solution and N, N’-dicyclohexylcarbodiimide was used crosslinking agent, to further functionalize with palmitic acid to introduce O-donor sites in the chitosan chain. These sites entrap metal ions forming covalent bonds leading to removal of heavy metal ions. The product was characterized using Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental analysis, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, and proton nuclear magnetic resonance. The introduction of palmitic acid into the chitosan chain did not only alter its original structure and crystallinity, as evidenced by XRD and SEM data, but enhanced stability and increased the affinity toward heavy metal ions. The adsorption processes were extensively examined under optimized conditions, and results revealed the maximum absorptivity values of 40.98, 21.8, and 47.6 mg/g for Cd(II), As(III), and Pb(II), respectively, indicating high adsorption capacity. The kinetic study suggested a pseudo-second-order reaction, and the Langmuir isotherm model demonstrated the best fit. The limits of detection for Cd, As, and Pb were 2.9, 4.3, and 15.1 ppb, while the limits of quantification were 9.07, 13.23, and 45.77 ppb, respectively. The desorption studies showed the regeneration and reusability of the adsorbent up to four cycles.

A laboratory study on the durability of limestone wastes in harsh environments for their suitability as aggregate in concrete

One of the critical environmental issues in the Chegeni area (Lorestan Province, western Iran) is the production of a large volume of limestone wastes during the quarrying operations. Releasing limestone wastes in the areas neighboring the quarries has caused visual damage to the environment, and adverse effects on the quality of the soil, running water, and groundwater used for agricultural and drinking water purposes. One solution to this issue can be recycling limestone wastes to produce building materials. In the present study, a comprehensive laboratory program is planned for the durability evaluation of the limestone wastes under harsh environments for their suitability as aggregate in concrete. For this purpose, five aging tests, including freeze-thawing (F-T), salt crystallization (SC), acid attack (AA), wetting-drying (WD), and heating-cooling (HC), were conducted on the limestone sample up to 60 cycles. After every 10 cycles, the physico-mechanical characteristics of the sample, including porosity (n), Brazilian tensile strength (BTS), point load index (PLI), and P-wave velocity (Vp) were determined. Moreover, the pores structure modification of the sample subjected to aging tests was examined through scanning electron microscopy (SEM). Data analyses revealed that the sample is highly vulnerable to the AA and SC processes but is durable against FT, WD, and HC actions. These results were in good agreement with the SEM data such that the sample exposed to AA and SC underwent more changes in their pore structure compared to FT, WD, and HC. Among the physico-mechanical characteristics, the Vp and PLI had the highest and the lowest accuracy, respectively, in the durability evaluation of the sample exposed to aging tests. Based on the data analysis, limestone wastes can be used as aggregate in concrete in environments with the possibility of FT, WD, and HC. However, this type of concrete is not suitable for conditions with occurrences of the AA and SC. Finally, in addition to reducing the environmentally harmful impacts of the study area, using limestone wastes as aggregate in the construction of concrete can also be a practical solution for sustainable development from an economic viewpoint. The results of the present study can be used for assessing limestone wastes produced in other areas of Iran and the world.

Composition and state prediction of lithium-ion cathode via convolutional neural network trained on scanning electron microscopy images

High-throughput materials research is strongly required to accelerate the development of safe and high energy-density lithium-ion battery (LIB) applicable to electric vehicle and energy storage system. The artificial intelligence, including machine learning with neural networks such as Boltzmann neural networks and convolutional neural networks (CNN), is a powerful tool to explore next-generation electrode materials and functional additives. In this paper, we develop a prediction model that classifies the major composition (e.g., 333, 523, 622, and 811) and different states (e.g., pristine, pre-cycled, and 100 times cycled) of various Li(Ni, Co, Mn)O2 (NCM) cathodes via CNN trained on scanning electron microscopy (SEM) images. Based on those results, our trained CNN model shows a high accuracy of 99.6% where the number of test set is 3840. In addition, the model can be applied to the case of untrained SEM data of NCM cathodes with functional electrolyte additives.

Influence of Biogenic Material Content on the Biodegradability of Styrene-Butadiene Composites with Incorporated Chlorella vulgaris Biomass.

Bio-fillers are intensively studied for advanced polymer composite circular design and production. In this context, the algal biomass may be considered an important and relatively low-cost resource, when harvested as a by-product from wastewater treatment plants. The biomass of the algal species Chlorella vulgaris is frequently used in this type of environmental process, and its macro constituents' composition ranges from around 15-25% carbohydrates, 10-20% lipids, and 50-60% proteins. Poly (styrene-butadiene-styrene) (SBS) copolymers have a matrix composed of glassy polystyrene domains connected by flexible polybutadiene segments. Although the physical-mechanical properties of SBS copolymers recommend them for many industrial applications, they have the drawback of low biodegradability. This study aimed to assess the aerobic biodegradability of polymer composites by integrating biomass from Chlorella vulgaris at varying mass percentages of 5, 10, and 20% into SBS copolymer composites. Biodegradation tests were conducted under industrial composting conditions (58 °C and 50% relative humidity) for 180 days. The biodegradability of materials was evaluated by measuring the CO2 produced in each vessel during the study period. Potential correlations between the amount of carbon dioxide released and the percentage of biomass added to the polymer matrix were examined. Structural and morphological changes were assessed using Fourier Transform infrared spectroscopy (FTIR), thermal analysis (DSC), and scanning electron microscopy (SEM). Physical and chemical testing revealed a decrease in sample density after the industrial composting test, along with noticeable changes in melt flow index (MFI). The observed physical and chemical changes, coupled with FTIR, SEM, and DSC data, indicate increased cross-linking and higher porosity in biodegraded polymer structures with higher biomass content. This behavior is likely due to the formation of cross-linked connections between polymer chains and polypeptide chains resulting from protein degradation, enhancing connections between polystyrene units facilitated by peptide bonds with the benzene units of the styrene blocks within the polymer matrix.

Evaluation of electrochemical performance of antimony modified screen-printed carbon electrodes

This study compares the electrochemical performance of screen-printed carbon electrodes (SPCEs) modified with antimony (Sb/SPCEs) under different potentiostatic pre-plating conditions. Neutral Red (NR) was employed as a novel redox probe to evaluate the electrochemical performance of Sb/SPCEs. It was demonstrated that NR in the protonated form performs quasi-reversible redox transformations at bare SPCE and Sb/SPCEs in phosphate buffer solutions (pH 5.5±0.5) in the potential range of (−0.30)–(−0.75) V, where the antimony is not electroactive. Sb/SPCEs were studied electrochemically by cyclic voltammetry (CV) / electrochemical impedance spectroscopy (EIS), and morphologically by scanning electron microscopy (SEM). Cyclic voltammetry investigations revealed the dependence of the electrochemical performance of Sb/SPCEs on the degree of coverage of the substrate with the metal. The obtained CV, EIS, and SEM data are consistent. The lowest charge transfer resistance (Rct) value (6 Ω) was obtained at Sb/SPCE with the highest degree of antimony coverage. To investigate the electroanalytical performance of Sb/SPCEs, nickel (II) ions were utilized as a model analyte. A study of roughness factors and sensitivity towards nickel (II) ions for Sb/SPCEs using two-tailed Pearson's criterion revealed a high degree of correlation between their electrochemical and electroanalytical properties. The results show that using NR as a redox probe can help controlling modification processes during the development of innovative antimony-containing sensors.

Equivalent density of calcium deposits – a new diagnostic pattern for atherocalcinosis

Objective. To assess the density of the calcified substrate of atherosclerotic plaques of the carotid arteries using data from the computed tomography of patients with multifocal atherosclerosis. Material and methods. In 251 patients with verified atherosclerosis of the coronary and carotid arteries, with a high prevalence of angina pectoris, a history of myocardial infarction and modifiable cardiovascular risk factors, multislice computed tomography (MSCT) of the carotid arteries was performed to assess the calcium index and determine the equivalent density of calcium deposits (EDCD). A morphological sub-study of the material from the removed atherosclerotic plaques was carried out using scanning electron microscopy (SEM) in 12 patients. Results. According to the MSCT data, we identified 5 main types of calcium deposit location in the thickness of the atherosclerotic plaque. We noted that totally calcified plaques were associated with carotid artery stenosis by more than 30 %. According to the SEM data, we identified 2 leading patterns: diffuse and compact types of microcalcification. There was a statistically significant association of a low level of EDCD with a diffuse type of calcification both in vivo (p=0.010) and ex vivo (p=0.008). Patients, having carotid artery EDCD less than 0.21 mg/mm3, reported a significantly higher incidence of type 2 diabetes mellitus (p=0.0001) and a history of stroke (p=0.021). When comparing the MSCT data on the calcium deposit density and their localization in the atherosclerotic plaque, we noted a statistically significant predominance of low EDCD with superficial calcification of the plaque (p=0.002). Conclusion. The use of a calculated indicator of the equivalent density of calcium deposits of the atherosclerotic substrate allows us to non-invasively obtain new data on the structure of plaques. The observed association of the superficial distribution of calcification with low calcification density according to the MSCT data may indicate potential plaque instability.

Syzygium cumini-mediated Green Synthesis of Magnesium Oxide Nanoparticles and Evaluation of their Antibacterial, Antileishmanial, and Antioxidant Activities

Green protocols for the synthesis of nanoparticles have gained significant attention due to their environmental friendliness, ease, and cost-effectiveness. The present study focused on the synthesis of magnesium oxide nanoparticles (MgO-NPs) using an aqueous leaves extract of Syzygium cumini plant, and the antimicrobial potential of the synthesized NPs. Methods: The synthesis of MgO-NPs was achieved by mixing a solution of magnesium nitrate (Mg (NO3)2 with an aqueous extract obtained from S. cumini leaves to reduce the Mg+ ions. These NPs were characterized by X-ray diffraction (XRD), Fourier-Transform Infrared (FTIR) Spectroscopy analysis, Scanning electron microscopy (SEM), and Energy-dispersive X-ray (EDX) analysis. Results: The transformation in color of the solution from yellow to deep brown along with the UV absorption peak at 294 nm showed the effective synthesis of MgO-NPs. SEM and XRD data revealed cubic-shaped NPs with an average size of 23.73 nm. EDX analysis confirmed the presence of magnesium and oxygen in the sample at 31.85% and 35.11% weight percentages, respectively. The antibacterial evaluation demonstrated effectiveness against the gram-negative strains Citrobacter koseri and Pseudomonas aeruginosa, with inhibition zones of 28.1 ± 1.25 mm and 27.8 ± 1.25 mm, respectively. MgO-NPs also showed antileishmanial potential against Leishmania tropica promastigotes (68.41 ± 0.05% inhibition at 1000µg/ml). Furthermore, the NPs exhibited antioxidant properties (75.12 ± 4.29% at 1 mg/ml) as determined by the DPPH radical scavenging assay. Conclusions: MgO-NPs synthesized using S. cumini plant leaves extract hold promises as agents for antibacterial, antileishmanial, and antioxidant applications.

Eco-friendly methanolic Ajuga orientalis extract as corrosion inhibitor for aluminium in 1.0 M NaOH

The inhibitory impact of the methanolic Ajuga orientalis (MAO) extract on Al corrosion in 1.0 M NaOH solution was examined using weight loss with electrochemical polarisation and scanning electron microscopy (SEM) techniques. According to the findings, the extract was an effective inhibitor in basic condition, as well as inhibition effectiveness increased with concentration. Furthermore, temperature studies revealed a loss in efficiency followed by a rise when temperature rose, followed by an increase and a fall in the fundamental media when the temperature increased from 30 °C to 50 °C. Frumkin, Freundlich and El Awady isotherms were used to mimic the inhibitor's adsorption properties. For the inhibitory behaviour, physical and chemical adsorption mechanisms are proposed. The adsorption process's thermodynamic parameters (ΔH*, ΔS* and Ea) were determined and explained. The inhibitor was examined as a mixed-type (anodic and cathodic) inhibitor based on polarisation studies. The inhibitor, according to the SEM data, is partially coating the metal surface, providing it with a reasonable amount of protection. The findings from weight loss, electrochemical polarisation, SEM and quantum chemical calculations collectively demonstrate a strong consensus, indicating that the MAO extract exhibits high effectiveness as an inhibitor for aluminium in a basic solution.

Effects of Poly(Vinylidene Fluoride-co-Hexafluoropropylene) Nanocomposite Membrane on Reduction in Microbial Load and Heavy Metals in Surface Water Samples

In this work, nanocomposite membranes were prepared using silver nanoparticles (Ag) attached to poly(amidoamine) dendrimer (P)-functionalised multi-walled carbon nanotubes (CNTs) blended with poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP) polymeric membranes (i.e., AgP-CNT/PVDF-HFP) via the phase inversion method. The nanocomposites were characterised and analysed via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), thermal gravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) analysis. The TEM and EDX analyses confirmed the presence of Ag nanoparticles on the nanocomposites, while the SEM and BET data showed the spongy morphology of the nanocomposite membranes with improved surface areas. The sample analysis of surface water collected from the Sekhukhune district, Limpopo Province, South Africa indicated that the water could not be used for human consumption without being treated. The nanocomposite membranes significantly reduced the physicochemical parameters of the sampled water, such as turbidity, TSS, TDS and carbonate hardness, to 4 NTU, 7 mg/L, 7.69 mg/L and 5.9 mg/L, respectively. Significant improvements in microbial load (0 CFU/mL) and BOD (3.0 mg/L) reduction were noted after membrane treatment. Furthermore, toxic heavy metals such as chromium, cadmium and nickel were remarkably reduced to 0.0138, 0.0012 and 0.015 mg/L, respectively. The results clearly suggest that the AgP-CNT/PVDF-HFP nanocomposite membrane can be used for surface water treatment.

Fabrication of novel strontium-coated bioactive ceramic-glass (C2S(2P6)C2S) 3D-porous scaffold for the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells

This study fabricated novel multilayer 3D-scaffolds by coating bioactive Calcium silicate (Ca2SiO4)/glass phase (calcium ultraphosphate, Ca2P6O17)/Ca2SiO4 (C2S(2P6)C2S) 3D scaffolds with strontium (Sr) for osteogenic differentiation of bone marrow-derived mesenchymal stem cells (MSCs). Hence, for the first time, C2S(2P6)C2S/Sr 3D-scaffolds were fabricated by sol-gel method and their characterization (X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM) and Mercury Porosimetry), effect in MSCs proliferation (cytotoxicity and mRNA expression) and osteogenic differentiation (staining and mRNA expression) were evaluated. The porosity and SEM data showed that the porosity (31.66% for C2S(2P6)C2S and 32.14% for C2S(2P6)C2S/Sr), pore size (<300 μm) and microstructure were not altered between C2S(2P6)C2S and C2S(2P6)C2S/Sr 3D-scaffolds, respectively. MSCs proliferation rate was increased by C2S(2P6)C2S/Sr 3D-scaffold via upregulating c-Fos and TGF-β1 mRNA expression. Alizarin Red (calcium), von-kossa (calcium-phosphate) and alkaline phosphatase (ALP) staining were higher in differentiated MSCs cultured on C2S(2P6)C2S/Sr 3D scaffold than in control. The osteogenic stimulatory effect of C2S(2P6)C2S/Sr 3D scaffold could be justified by increasing osteogenic stimulatory genes such as collagen type-I, Runx2, osteocalcin and ALP expression in differentiated MSCs. Further, SEM images proved that the C2S(2P6)C2S/Sr 3D scaffold-cultured cells had unique morphology similar to biological tissues. Accordingly, this is the first report evidencing the MSC proliferative and osteogenic stimulatory ability of strontium-coated C2S(2P6)C2S 3D-scaffold, which greatly impacts future strategic therapies in dentistry and bone regeneration.

Neutral Red as a Redox Probe for Comparative Evaluation of Electrochemical Performance of Bismuth Modified Electrodes

For the first time, Neutral Red (NR) has been used as a redox probe for comparative evaluation of the electrochemical performance of screen-printed carbon electrodes (SPCEs) modified with bismuth under different potentiostatic pre-plating conditions (Bi/SPCEs). It was shown that protonated NR undergoes quasi-reversible redox transformations at bare-SPCE and Bi/SPCEs in the pH range 5–6 in phosphate buffer solutions (PBS) in the potential range of (−0.2)–(−0.8) V, where bismuth is not electroactive. Bi/SPCEs have been characterized morphologically by scanning electron microscopy (SEM) and electrochemically by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) employing NR as a redox probe. The obtained SEM, CV, and EIS data are in good agreement. The highest charge transfer resistance (Rct) values (3.9 and 3.3 kΩ) were obtained at bare-SPCE and Bi/SPCE having low degree of bismuth coverage. Contrarily, the lowest Rct value (8 Ω) was recorded at Bi/SPCE, with the highest degree of bismuth coverage. CV experiments showed a significant increase in the electrochemical performances of Bi/SPCEs, whose surface is half or more covered with bismuth, in comparison to the bare-SPCE. Nickel (II) ions and formaldehyde (FM), in the form of formaldehyde hydrazone (FAH), were used as model analytes to determine the electroanalytical performance of Bi/SPCEs. A comparison of roughness factor and sensitivity toward both analytes for Bi/SPCEs with two-tailed Pearson’s criterion showed a high degree of correlation between their electrochemical and electroanalytical characteristics. The data acquired indicates that the use of NR as a redox probe may be quite helpful to control modification processes when developing novel bismuth-containing sensors.

Synthesis, Photophysical Properties and Self-Assembly of a Tetraphenylethylene-Naphthalene Diimide Donor-Acceptor Molecule.

The development of new π-conjugated molecular structures with controlled self-assembly and distinct photophysical properties is crucial for advancing applications in optoelectronics and biomaterials. This study introduces the synthesis and detailed self-assembly analysis of tetraphenylethylene (TPE) functionalized naphthalene diimide (NDI), a novel donor-acceptor molecular structure referred to as TPE-NDI. The investigation specifically focuses on elucidating the self-assembly behavior of TPE-NDI in mixed solvents of varying polarities, namely chloroform: methylcyclohexane (CHCl3 : MCH) and chloroform: methanol (CHCl3 : MeOH). Employing a several analytical methodologies, including UV-Vis absorption and fluorescence emission spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS), these self-assembled systems have been comprehensively examined. The results reveal that TPE-NDI manifests as distinct particles in CHCl3 : MCH (fMCH =90 %), while transitioning to flower-like assemblies in CHCl3 : MeOH (fMeOH =90 %). This finding underscores the critical role of solvent polarity in dictating the morphological characteristics of TPE-NDI self-assembled aggregates. Furthermore, the study proposes a molecular packing mechanism, based on SEM data, offering significant insights into the design and development of functional supramolecular systems. Such advancements in understanding the molecular self-assembly new π-conjugated molecular structures are anticipated to pave the way for novel applications in material science and nanotechnology.

Синтез углеродных нанотрубок с помощью СВЧ излучения для модификации эластомера с улучшенной электро- и теплопроводностью

The paper presents a method of microwave influence on ferrocene C10H10Fe and graphite to obtain multilayer carbon nanotubes (MWCNTs) — designed to improve the electrical and thermophysical properties of silicon-graphite elastomer (Silagerm 8020). Diagnostics and characterisation of the synthesised MWCNTs were carried out by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. According to SEM data, it follows that the morphology of the synthesised MWCNTs has the form of filamentous formations intertwined in bundles with the diameter of individual MWCNTs from 40 to 60 nm and length up to several microns. At the same time, the surface of most of the MWCNTs is covered with a continuous layer of iron (Fe). The EDX method also confirmed the Fe and oxygen content on the surface of the MWCNTs. XRD method identified the presence of Fe in combination with carbon in the form of Fe3C iron carbide and pure Fe iron at 44.7°. The compound Fe3C, also referred to the active phase of Fe allowing the synthesis of MWCNTs. By increasing the concentration of MWCNTs in the elastomer, an increase in thermal conductivity with percolation transition was achieved at a concentration of 8 % MWCNTs. The maximum thermal conductivity of the nanomodified elastomer was 0.48 W/(m·°C), which corresponded to the mass concentration of MWCNTs equal to 8 wt.%. At the same time, the electrical conductivity of the composite, when the MWCNTs concentration was changed from 1 to 8 %, increased in the range from 4·10–5 to 2.4 cm·cm–1 and is also due to the percolation of MWCNTs in the elastomer matrix.

Feasibility study on superabsorbent polymer (SAP) as internal curing agent for cement-based grouting material

The closed working condition of grouting materials leads to insufficient curing water supply during their strength development. In this work, the superabsorbent polymer (SAP) was used as the internal curing agent for grouting material. The effects of SAP content on the rheological and mechanical properties of grouting material were studied under various water-cement ratios (w/c) and curing environments. The time-dependent variation of fresh slurry's viscosity was measured by Brinell viscometer. The pore structure and micromorphology characteristics were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscope (SEM). The results indicate that the addition of SAP increases the viscosity of fresh slurry and decreases its fluidity, thereby improving the slurry's internal uniformity at a higher w/c. And in its actual working condition, grouting material's strength can be boosted with less than 0.3% SAP dosage. Although SAP will introduce some irregular mesoscopic pores (0.2 − 0.3 mm), the MIP data analysis proves SAP refines the microscopic pore structure of grouting materials. SEM data analysis proves SAP optimizes the microstructure of grouting material, which cured in dry environment. In general, SAP improves the internal uniformity of grouting material by absorbing excess mixing water and gradually releasing it to promote cement hydration, which improves the strength of grouting material. Hence, SAP is a practicable internal curing agent for grouting material and 0.2% is the recommended dosage.

A novel solar disk chamber reactor for agricultural waste recycling and biochar production

The quality and properties of biochar are generally influenced by the nature of the raw materials and pyrolysis techniques. To assess the quality of sesame biochar production, a disc chamber reactor set on a solar parabolic dish concentrator was proposed as a modified slow pyrolysis technique. To evaluate the physicochemical characterizations of the produced biochar, two pyrolysis settings were used: 470 °C for 1 h (T1) and 440 °C for 2 h (T2) to produce biochar from sesame stalk feedstock (SS) using the proposed solar disk chamber reactor. Ash content, mass fraction of elements (C, H, and O%), pH, surface area, zeta potential, Fourier transform infrared (FTIR), and scanning electron microscope (SEM) were investigated. The results showed that the mass of T1 biochar decreased by 5% when compared to T2, while ash content, pH, fixed carbon, and volatile gases for both biochars were relatively close. The H/C and O/C molar ratios were below 1.00 and 0.4, respectively, indicating a loss of degradable polar contents and the formation of aromatic compounds. The surface area of T2 biochar was three times the surface area of T1, with the opposite trend in mean pore diameter. Two biochars showed the same FTIR peaks and SEM data, with small differences in their characteristics, demonstrating that pyrolysis time and temperature had a tight relationship. Both biochars showed approximately similar properties. The reactor’s efficiency is mainly affected by solar energy and atmospheric conditions during operation, which influence the average surface temperature. In Egypt, climatic conditions would be more favorable in the summer to improve the efficiency of parabolic solar dish concentrators for producing high-quality biochar.Graphical abstract

Enhancing Antioxidant Activity of Curcumin Using ZnO Nanoparticles Synthesized by Electrodeposition Method

The objective of this study was to fabricate zinc oxide (ZnO) nanoparticles through the utilization of the electrodeposition technique, to employ them as a supportive medium for enhancing the antioxidant properties of curcumin. The study involved the synthesis of ZnO nanoparticles, which were subsequently subjected to characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Additionally, the antioxidant activity of the synthesized nanoparticles was assessed through the use of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. In XRD analysis, a notable peak denoted by an asterisk (*) is observed at specific angles of 2θ: 25.84°, 31.63°, 34.21°, and 36.12°, with corresponding index values (h, k, l) of (220), (100), (002), and (101), respectively. This peak is indicative of the degree of crystallinity exhibited by ZnO nanoparticles. The SEM data indicates that the particles generated possess a rod-like morphology, exhibiting a range of sizes. The Nyquist plots exhibit a semicircular arc pattern at low frequencies, as indicated by the findings from the EIS test. The data obtained from antioxidant assays indicated that ZnO-curcumin achieved an inhibition level of 47.09%, while curcumin alone showed a significantly lower inhibition percentage of 4.93%.

Characterization of Nano-Structured Magnesium-Aluminum Ferrites Synthesized by Citrate-Gel Auto Combustion Method

An effort is made to find the solution to the new challenges of modification advancements in ferrite technologies. The hypothetical variation in the structural, magnetic, and electrical properties of cubic spinel magnesium aluminum ferrites introduced by the substitution of doping elements has been rationalized and proven. The outcome of aluminum substitution on the magnesium ferrites has been examined and investigated. Spinel ferrites having compositions of MgAlxFe2-xO4 (x = 0.1, 0.2, 0.3, 0.4) were prepared by the sol-gel auto-combustion method. The prepared sample’s characterization, such as scanning electron microscopy (SEM), DC electrical resistivity, AC electrical resistivity, and dielectric properties measurements, were tested using the respective instruments. The grain size and crystal size of all samples were measured from the micrographs of SEM and XRD Data. It is found that the average grain size is within the range of 300 nm - 550 nm for all different series that are formed, keeping the samples at 1100 °C sintering temperatures. A two-probe method experiment with a temperature range of 30 °C to 500 °C gives data on DC electrical resistivity. The Curie temperature depends on the sintering temperature, and it increases with increasing doping concentration. Also, doping influences grain size, which decreases with increasing concentration. Analyzing the SEM micrographs, it is found that the average grain size must decrease in tendency with increasing Al content. DC electrical resistivity exhibits excellent semiconducting behavior. Frequency dependence, dielectric constant, and dielectric loss factors were measured, keeping the frequency range of 75 Hz to 130 MHz at room temperature. The result shows that the dielectric constant (e) and dielectric loss tangent (tan™) decrease with the increase in frequency, while the AC resistivity and Q-factor increase. Comparing the electrical properties of four compositions, it can be suggested that the mixed ferrite, sample-4 (x = 0.3), shows the highest Q-factor of all at 1100 °C.

Modified alginate-based soft tissue adhesive: Synthesis, characterization, and application in the treatment of in vivo wound closure

The management of acute and chronic wounds is still a challenge around the world, despite the development of many wound dressing materials and techniques, such as cyanoacrylate-based glue, fibrin glue, suturing, and stapling. To get over this difficulty, a soft tissue adhesive (STA) has been developed by combining bioabsorbable chitosan (CS) and aldehyde sodium alginate (ASA) crosslinked by the Schiff base mechanism and are characterized via the FTIR spectroscopy analysis, Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic (SEM) analysis. Sodium alginate (SA) was converted into aldehyde sodium alginate (ASA) by oxidation, which made it biodegradable (79.2% weight loss at the 9th day) and greatly affected the swelling behavior (only 60% in CS + ASA), and gelation time (7–10 s) of the soft tissue adhesive. The hydrogel's surface has an adhesive characteristic and is quite smooth, according to the SEM data. The antimicrobial test of the STA confirmed that the adhesive material had good antibacterial efficacy. The bonding ability and biocompatibility of the STA were evaluated by measuring the adhesive strength after sealing the skin incisions on the back of mice. These findings imply that the generated adhesive may be a strong and reliable tissue adhesive with great potential for use in soft tissue adhesion.

Novel Meta-iodobenzylguanidine and Etoposide Complex: Physicochemical Characterization and Mathematical Modeling of Anticancer Activity.

It is hypothesized that meta-iodobenzylguanidine (MIBG) complexation with etoposide (VP-16) will improve drug solubility and specificity towards BE(2)C neuroblastoma (NB) cells, 90% of which are known to be MIBG avid. After MIBG and VP-16 interaction, the dry complex was analyzed for crystalline structure, surface morphology, solubility, and size distribution by X-ray powder diffraction (P-XRD), scanning electron microscopy (SEM), infrared (FTIR) and UV spectroscopy, and dynamic light scattering. After exposure to the complex, the cell viability and decay rates were assessed by the MTS assay and estimated using exponential decay models (EDM). Multi-factorial ANOVA and an independent t-test were used to assess for cell viability and solubility data, respectively. The resulting (1: 3 w/w) VP-16: MIBG complex had a mean diameter and zeta potential of 458.5nm and 0.951mV, respectively. It dramatically increased the drug apparent water solubility (~ 12-folds). This was ascribed to the formation of a VP-16/MIBG nanocrystalline state mainly governed by cation-π interactions, evidenced by FTIR, SEM, and P-XRD data following the complexation. The EDM relating percent cell viability to drug concentration yielded an excellent fit (r2 > 0.95) and enabled to estimate the IC50 values of both native drug and its complex: 6.2μM and 5.23μM, respectively (indicating a conservation of drug anticancer activity). The statistical results were consistent with those of the exponential decay models, indicating that MIBG does not inhibit the anticancer activity of VP-16. This study indicates that the VP-16/MIBG complexation improves VP-16 solubility without antagonizing its anticancer activity. Moreover, the efficiency of the EDM for drug IC50 estimation provides alternative mathematical method for such in vitro cytotoxicity studies.