Energy Dispersive Spectroscopy Analysis Research Articles

Genome-Wide Identification and Characterization of the Homeodomain Leucine Zipper Protein (HD-Zip) Gene Family in Sea Buckthorn (Hippophae rhamnoides) Under Lead Stress

This study investigates the role of sea buckthorn HD-Zip genes in response to lead stress, identifying 28 genes distributed across 10 chromosomes, which are classified into four subfamilies. Each subfamily exhibits a similar gene structure and conserved protein motifs. The HD-Zip gene family is notably enriched in stress-responsive elements. Transcriptomic analysis revealed differential expression among the 28 members of the HD-Zip gene family in sea buckthorn, varying with different Pb ion concentrations. Upregulated genes were predominantly observed at stress concentrations of 1 g/kg and 5 g/kg, while downregulated genes were more prevalent at the 0.5 g/kg stress concentration. Covariance analysis indicated that large-scale gene duplication was the primary mechanism driving the expansion of the sea buckthorn HD-Zip gene family. Additionally, analysis of three-dimensional protein structures demonstrated high conservation within the HD-Zip gene, suggesting that certain sea buckthorn HD-Zip proteins may play significant regulatory roles in physiological functions. Scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS) analysis revealed that the majority of lead ions accumulated in the roots of the seedlings, with the lead concentration affecting the number, density, and function of leaf slits. These findings enhance our understanding of the complex regulatory mechanisms governing HD-Zip genes and will contribute to the genetic improvement of sea buckthorn for breeding under lead stress conditions.

Time-resolved spectroscopy uncovers deprotonation-induced reconstruction in oxygen-evolution NiFe-based (oxy)hydroxides

Transition-metal layered double hydroxides are widely utilized as electrocatalysts for the oxygen evolution reaction (OER), undergoing dynamic transformation into active oxyhydroxides during electrochemical operation. Nonetheless, our understanding of the non-equilibrium structural changes that occur during this process remains limited. In this study, utilizing in situ energy-dispersive X-ray absorption spectroscopy and machine learning analysis, we reveal the occurrence of deprotonation and elucidate the role of incorporated iron in facilitating the transition from nickel-iron layered double hydroxide (NiFe LDH) into its active oxyhydroxide. Our findings demonstrate that iron substitution promotes deprotonation process within NiFe LDH, resulting in the preferential removal of protons from the specific bridged hydroxyl group (Ni2+-OH-Fe3+) linked to edge-sharing [NiO6] and [FeO6] octahedron. This deprotonation behavior drives the formation of high-valence Ni3+δ species (0 <δ < 1), which subsequently serve as the active sites, thereby ensuring efficient oxygen evolution activity. This approach offers high-resolution insights of dynamic structural evolution, overcoming the limitations of extended acquisition times and advancing our understanding of OER mechanisms.

A Facile Synthesis of Bimetallic Copper-Silver Nanocomposite and Their Application in Ascorbic Acid Detection

Background: An important antioxidant, ascorbic acid, must be detected in several industrial samples collected from food, pharmaceuticals, and water treatment plants. Herein, we reported a method to produce a bimetallic copper-silver (Cu-Ag) nanocomposite and used it in the development of very sensitive and selective electrochemical sensor for the detection of ascorbic acid. Methods: A simple chemistry concept was used during the synthesis process to reduce the cost while minimizing the use of dangerous chemicals and minimizing the environmental impact. The Strobilanthes kunthiana leaves extract effectively reduced the copper and silver ions, resulting in the creation of an extremely stable and evenly distributed Cu-Ag nanocomposite. Results: As-prepared bimetallic Cu-Ag nanocomposite exhibited outstanding electrochemical activity against ascorbic acid oxidation. The nanocomposite was examined using field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), elemental mapping (EMap) and X-ray diffraction analysis (XRD) to ascertain its composition, structure, and stability. Using cyclic voltammetry (CV), the electrochemical performance of the nanocomposite and also the detection of ascorbic acid were carried out. The bimetallic Cu-Ag nanocomposite also exhibited better long-term stability and fouling resistance, making it appropriate for use in real-world applications and complex sample matrices. Conclusion: The bimetallic Cu-Ag nanocomposite coated electrode was used to detect the concentration of ascorbic acid by amperometry. As a result, this study offered a simple chemical method for creating a bimetallic copper-silver nanocomposite with superior electrochemical qualities for the accurate detection of ascorbic acid.

A Study on Corrosion Inhibition Effects Based on CS-NR Application Results on Leakage Accidents of Sprinkler Copper Pipes

Copper has better corrosion resistance than iron and good physical and chemical properties, including high electrical and heat conductivities. Therefore, it is widely used in various industrial applications. However, pitting corrosion occurs in the copper pipe of the sprinkler due to the oxygen concentration of the cell by the deposition of foreign substances on the inner side of the copper pipe, and leakage often occurs in the copper pipe due to the formation of shot holes. In this study, when a copper plate was submerged in a 3% NaCl solution for 10 days and the effects of the addition of CS-NR (6, 8, and 10 g) on corrosion protection were investigated by observing the surface conditions of the test specimen using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis by map the SEM results. The surface of the test specimen immerged only in the 3% NaCl solution without the addition of CS-NR exhibited pitting corrosion due to chloride ions. However, with the addition of CS-NR, pitting corrosion was not observed at the surface, regardless of the amount of CS-NR added. Furthermore, the addition of 8 g (8 × 10&lt;sup&gt;3&lt;/sup&gt; ppm) of CS-NR resulted in the best corrosion resistance against pitting corrosion because the amount of oxygen and silicon that formed the protective film revealed an optimal mixed ratio as compared with 6 and 10 g of CS-NR.

Studies on the Effect of Laser Shock Peening Intensity on the Mechanical Properties of Wire Arc Additive Manufactured SS316L

This study examines the impact of laser shock peening (LSP) on the mechanical properties, microstructural features, and elemental distribution of stainless steel 316L (SS316L) produced using wire arc additive manufacturing (WAAM). The investigation focuses on significant changes in mechanical behavior, surface topography, and porosity following LSP treatment, comparing these results to the untreated condition. LSP treatment significantly enhanced the ultimate tensile strength (UTS) and yield strength (YS) of WAAM-fabricated SS316L samples. The UTS of the as-manufactured WAAM specimen was 548 MPa, which progressively increased with higher LSP intensities to 595 MPa for LSP-1, 613 MPa for LSP-2, and 634.5 MPa for LSP-3, representing a maximum improvement of 15.8%. The YS showed a similar trend, increasing from 289 MPa in the as-manufactured specimen to 311 MPa (LSP-1) and 332 MPa (LSP-2), but decreasing to 259 MPa for LSP-3, indicating over-peening effects. Microstructural analysis revealed that LSP induced severe plastic deformation and reduced porosity from 14.02% to 4.18%, contributing to the improved mechanical properties. Energy dispersive spectroscopy (EDS) analysis confirmed the formation of an oxide layer post-LSP, with an increase in carbon (C) and oxygen (O) elements and a decrease in chromium (Cr) and nickel (Ni) elements on the surface, attributed to localized pressure and heat impacts. LSP-treated samples exhibited enhanced mechanical performance, with higher tensile strengths and improved ductility at higher laser intensities. This is due to LSP effectively enhancing the mechanical properties and structural integrity of WAAM-fabricated SS316L, reducing porosity, and refining the microstructure. These improvements make the material suitable for critical applications in the aerospace, automotive, and biomedical fields.

Development of cordierite‐based low‐expansion porcelain tiles with application potential in an underfloor heating system

AbstractThe high coefficients of thermal expansion (CTEs; α) of common porcelain tiles result in deformation, cracking and even breakage after prolonged utilization in an underfloor heating system. Cordierite‐based porcelain tiles with low α values have good application potential in underfloor heating systems. Herein, environmentally friendly and low‐cost cordierite‐based porcelain tiles made with desert sand were presented. The bulk density, linear shrinkage, water absorption, CTE, and modulus of rupture were determined to investigate the sintering stage of this desert sand‐based low‐expansion porcelain tiles. Powder X‐ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses were used to characterize the phase changes and microstructures of the materials. The results revealed that mass ratio of SiO2 to Al2O3 (m[SiO2/Al2O3]), mass ratio of MgO to Al2O3 (m[MgO/Al2O3]), and sintering temperature jointly affected the CTEs of the porcelain tiles. Moreover, the sintering temperature significantly impacted the quantities and morphologies of the cordierite crystals. An increase in the number of columnar‐like cordierite crystals during production resulted in a decreased CTE. The results of this study present an effective technique for preparing low‐CTE porcelain tiles from natural waste materials. These desert sand‐based tiles could be widely applied in underfloor heating systems.

Seasonal and Spatial Discrimination of Sandy Beaches Using Energy-Dispersive X-Ray Fluorescence Spectroscopy Analysis: A Comparative Study of Maltese Bays

The general increase in awareness of environmental pollutants and typical sources reflects the application of sustainability and development goals. Energy-Dispersive X-Ray Fluorescence spectroscopy analysis has been used to analyse sand samples collected from five different beaches located on the east and north-eastern coasts of Malta and Gozo during two summers and two winters. Samples were collected along linear transects perpendicular to the shoreline at three different depths. Chemometrics were used to discriminate between four latent variables, including season, location, depth, and distance from shoreline. The highest concentrations were attributed to Fe2O3, Al2O3, SrO, and SnO2. Principal Components Analysis and Factor Analysis classified distributions of Fe2O3, CoO, As2O3, MnO, SrO, SeO2, and CaCO3 under Principal Component 1. However, since no loading value dominance was observed, such distributions most likely represent a combination of lithogenic and anthropogenic natures. Discrimination using Stepwise Linear Canonical Discriminant Analysis (SLC-DA) and Partial Least Squares Discriminant Analysis (PLS-DA) using Leave-One-Out-Cross-Validation with Variance Importance Plots proved highly effective in classifying data by location, followed by seasonal variability. It follows that concentrations are not affected by depth and distance from shoreline variability, proving that accumulation and anthropogenic effects from land are not concentrated in specific zones but are spatially spread out along the bays and do not increase with depth.

Mesoporous Silica-Carbon Composites with Enhanced Conductivity: Analysis of Powder and Thin Film Forms.

The resistivity of the silica SBA-15 type can be significantly improved by forming a thin layer of carbon on the pore surface. This is possible through the carbonization reaction of a surfactant used as a structure-directing agent in the synthesis of mesostructured silica materials. The synthesis of this type of silica-carbon composite (SBA-C) is based on the use of sulfuric acid to create a carbon layer from surfactant molecules encapsulated in silica mesopores. The action of sulfuric acid takes place through dehydration and sulfonation reactions, which promote the formation of aromatic structures and favor crosslinking processes. The same procedure was applied to prepare MTF-C composites based on mesostructured thin films (MTFs). Compared to pure silica materials, these silica-carbon composites exhibit reduced pore diameter and volume while maintaining morphology and structure. The pore structure characteristics were obtained by scanning and transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, thermogravimetry, and isothermal sorption analysis. The composite obtained after carbon layer formation exhibited enhanced conductivity in comparison to pure silica SBA-15. The resistivity of SBA-C composite material after annealing at 800 °C under a nitrogen atmosphere decreased to 1980 Ωcm in comparison with pure SBA-15.

Evaluating Cost-effectiveness and Mixing Efficacy for Elastomeric and Temporary Restorative Material Using Two Mixing Tips: A SEM-EDS Analysis.

This study aimed to compare the mixing efficacy and cost-effectiveness of new T-mixer tips against the standard double helical tips for a light-body elastomeric impression and a temporary/interim restorative material using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy. Automixed samples (n = 16) were divided into four groups of four samples each: Samples that were mixed with Helical tip for elastomer, T-mixer tip for elastomer, Helical tip for interim restorative material, and T-mixer tip for interim restorative material. These samples were then evaluated for SEM analysis. Energy dispersive spectroscopy (EDS) analysis was conducted on three random surface spots and two cross-section spots. Tests for detail reproduction using ADA Specification 19 die and surface roughness using a stylus were also performed. Data were recorded and statistically analyzed. (Kindly mention whether the details of reproduction and surface roughness for all the groups are considered. Also, explain what factors SEM and EDS evaluate that contribute to the evaluation of mixing efficiency). For elastomer surface sample EDS analysis, the p-values were 0.180 (carbon) and 0.065 (silicone). Cross-section samples showed p-values of 0.343 (carbon and silicone). For temporary restorative material EDS analysis, surface p-values were 0.180 (carbon) and 0.394 (silicone), and cross-section p-values were 0.886 (carbon) and 0.686 (silicone). The groups mixed using T-mixer tips showed no change in the mixing efficacy as compared to the group mixed using helical tips for both materials. The p-values for cost-effectiveness were 0.021 for both elastomeric and Protemp temporary restorative material. The groups mixed using T-mixer tips saved more material than groups mixed using the helical tip. There is no significant difference in the mixing efficacy between T-mixer and helical tips for both materials. However, T-mixer tips are more cost-effective than helical tips. The present study would help clinicians make a better choice of selecting the mixing tips when it comes to function as well as cost. The new T-mixer tips are proven to provide a better solution compared to helical tips, which not only would save the clinicians' cost of impression materials and interim restorative materials but also render the same homogeneity as that of the helical tips. The electron microscopic analysis provided a better insight into the homogeneity and hence the mixing efficacy of the samples. The detail reproduction and surface roughness were some additional parameters that weren't a part of the original study model. They were included for the addition of credibility to the conducted study and provided adjunctive results to those obtained by SEM and EDAX analysis. How to cite this article: Bhave RP, Sabane AV, Vijayaraghavan V, et al. Evaluating Cost-effectiveness and Mixing Efficacy for Elastomeric and Temporary Restorative Material Using Two Mixing Tips: A SEM-EDS Analysis. J Contemp Dent Pract 2024;25(9):885-890.

Energy Transfer Studies on Red Emitting CaGdSbWO8: Sm3+/Eu3+ Phosphor for w-LEDs and Indoor Plant Growth Lighting System.

In the present research work, a solid-state reaction method was employed to synthesize a series of CaGd(0.95-x)SbWO8:Sm0.05Eux (x = 1, 1.5, 2, 3 and 4mol%) phosphors. The phase purity, crystallinity, morphological and compositional studies were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM) imaging, and energy dispersive spectroscopy (EDS) analysis. The Fourier transform infrared (FT-IR) spectroscopy was utilized to measure OH content in the prepared phosphor material. The diffused reflectance spectroscopy (DRS) analysis was applied to measure the optical energy band gap. The photoluminescence (PL) spectroscopy at excitation wavelengths 275 and 405nm was carried out to analyze the luminescence properties of the prepared phosphors. The intensity of emission peaks of Sm3+ ions decreased as the concentration of Eu3+ ions increased showing the energy transfer mechanism from Sm3+ to Eu3+ ions. The dipole-dipole interaction mechanism is responsible for the energy transfer between Sm3+ to Eu3+ ions as assessed using the Reisfeld approximation. The CIE coordinates of the prepared samples lie in the warm red region represented by the relatively low (3200K) value of correlated color temperature. These results show the suitability of the prepared phosphor for white light emitting diode (w-LEDs) and also in indoor plant growth lighting systems.

Mechanical Characterization of Main Minerals in Carbonate Rock at the Micro Scale Based on Nanoindentation

The mechanical characterization of carbonate rock is crucial for the development of a hydrocarbon reservoir and underground gas storage. As a kind of natural composite material, the mechanical properties of carbonate rock exhibit multiscale characteristics. The macroscopic mechanical properties of carbonate rock are determined by the mineral composition and structure at the micro scale. To achieve a mechanical investigation at the micro scale, this study designed a scheme for micromechanical characterization of carbonate rock. First, scanning electron microscope observation and energy dispersive spectroscopy analysis were combined to select the appropriate micromechanical test areas and to identify the mineral types in each area. Second, the selected test area was positioned in the nanoindentation instrument through the comparison of different-type microscopic images. Finally, quasi-static nanoindentation was carried out on the surface of different minerals in the selected test area to obtain quantitative mechanical evaluation results. A typical carbonate rock sample from the Huangcaoxia gas storage was investigated in this study. The experimental results indicated apparent micromechanical heterogeneity in the carbonate rock. The Young’s modulus of pyrite was over 200 GPa, while that of clay minerals was only approximately 50 GPa. In addition, the proposed micromechanical characterization scheme was discussed based on experimental results. For minerals with an unknown Poisson’s ratio, the maximum error introduced by the 0.25 assumption was lower than 15%. To discuss the effectiveness of the nanoindentation results, the characterization abilities constituted by lateral spatial resolution and elastic response depth were analyzed. The analysis results revealed that the nanoindentation measurement of clay was more susceptible to influence by the surrounding environment as compared to other kinds of minerals with the experimental setup in this study. The micromechanical characterization scheme for clay minerals can be optimized in future research. The mechanical data obtained at the micro scale can be used for the interpretation of the macroscopic mechanical features of carbonate rock for the parameter input and validation of mineral-related simulation and for the construction of a mechanical upscaling model.

Commercial organomineral fertilizer produced through granulation of a blend of monoammonium phosphate and pulp and paper industry waste post-composting

This study investigates a commercial granular organomineral fertilizer (GOF) produced by physically mixing landfill paper and cellulose industry waste composted over a long period with monoammonium phosphate (MAP), focusing on its morphological properties, and phosphate release into the water. The organic base used in the GOF composition is rich in humic and fulvic acids due to its long-term composting, rebalances the soil's organic matter, and eliminates a critical environmental liability. No studies have involved long-term lignocellulosic waste composting as the organic base of organomineral fertilizers. Most GOF and MAP granules range from 2 to 4 mm in size, with rough and macroporous surfaces observed through scanning electron microscopy. The specific surface area values of fertilizers are low compared to other fertilizers with different organic matrices. However, 2–4 mm granules exhibit similar values, indicating uniformity of granules. Infrared spectroscopy reveals bands from mineral and organic bases, with possible clay additives confirmed by the silicon detected in Energy Dispersive Spectroscopy analysis. Thermogravimetric curves exhibit improved thermal stability for GOF over the composted organic base, with a 31 °C increase in the second decomposition stage and delayed completion of the subsequent stages. However, this did not significantly alter the Tonset of the ammonium phosphate decomposition, as GOF presented a similar thermal behavior to MAP. GOF and MAP exhibit similar kinetic profiles, with rapid phosphorus release in the first 4 hours, reaching about 77 % of the available phosphorus. GOF shows an increase in specific surface area 29 times after 240 hours of contact with water, facilitating phosphorus release from the commercial mixture. MAP and GOF exhibit a release rate exceeding 84 %, indicating rapid phosphate availability. These values are comparable to those of other organomineral fertilizers. The results demonstrate that the GOF performs similarly to MAP, with lower phosphorus dosages, rebalance of soil organic matter, and increased nutrient application efficiency.

Modification of a O-acetyl-glucomannan from Dendrobium officinale by selenylation modification and its anti-gastric cancer enhancing activity.

In this study, a homogeneous polysaccharide, named YDOP-1 was isolated form Dendrobium officinale using hot water extraction and ethanol precipitation method. YDOP-1 was characterized to be a typical O-acetyl-glucomannan with the molecular wight was 13,456 Da. Cell viability and colony forming assay showed that YDOP-1 possess moderate anti-gastric cancer effects. In order to further improve the anti-gastric cancer effects of YDOP-1, a selenium modification on YDOP-1 was performed. Energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the Se was successfully introduced into YDOP-1 by forming SeO bonds. Se modification significantly enhanced the anti-gastric cancer effects of YDOP-1, which could effectively inhibit the proliferation of MGC-803 cells via suppressing colony and inducing apoptosis by regulating the apoptosis proteins of Bax, Bcl-2, and Caspase-7. Our results indicated that the Se modified O-acetyl-glucomannan, YDOP-Se, was expected to be useful in the biomedicine field for the gastric cancer treatment.

Study of the High-Temperature Sintering Characteristics of Boron Oxide Composite Silicon-Based Ceramics

This paper explores the application of boron oxide (B2O3) as a sintering additive in silicon-based (SiO2) ceramics, focusing on its impact on the sintering process and resulting ceramic properties. Composite silicon-based ceramic shells with boron oxide content ranging from 0 to 4 Wt% were prepared using digital light processing (DLP) technology. This study examines the effects of boron oxide on sintering temperature, apparent porosity, shrinkage rates, and mechanical properties during high-temperature sintering. Experimental results indicate that, as boron oxide content increases, the shrinkage rate of the ceramic samples rises progressively, with shrinkage in the XY direction increasing from 4.57% to 16.40% and in the Z direction from 6.25% to 17.03%. Concurrently, the apparent porosity decreases with higher boron oxide content, ranging from a maximum of 36.17% to a minimum of 23.27%. Bulk density also improves from 1.49 g/cm3 to 1.78 g/cm3. The bending strength trend first rises and then declines, peaking at 15.39 MPa at a boron oxide content of 3 Wt%. X-ray Diffraction and Energy Dispersive Spectroscopy analyses confirm that the addition of boron oxide promotes the formation of beta-quartz and that its liquid-phase behavior at high temperatures aids in enhancing ceramic densification. This study demonstrates that an appropriate amount of boron oxide can effectively lower the sintering temperature of silicon-based ceramics while improving their mechanical properties, providing a theoretical foundation and practical basis for broader industrial applications.

Impact of biochar prepared at different pyrolysis temperatures on the methane production and microbial community structure of food waste anaerobic digestion

Biochars were prepared through the pyrolysis of sawdust at 300 °C, 500 °C, and 700 °C, respectively, under oxygen-limited conditions. The basic physicochemical properties of biochars were explored by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), surface area and porosity analyzer (BET), and Fourier-transform infrared spectrometer (FTIR). The effects of biochar addition on the methane yield and microbial community structure of anaerobic digestion of food waste were also investigated. SEM images showed that biochar had a honeycomb-like pore structure, EDS analysis showed that the C content in the biochar tended to increase, and the O contents tended to decrease with the increasing temperature. The specific surface area of biochars increased from 1.2014 m2/g (300 °C) to 326.8435 m2/g (700 °C). FTIR analysis showed that the number of different surface functional groups decreased with the increasing temperature. The addition of biochar could increase the cumulative methane volume by 11.63%–25.18%. High-throughput sequencing results showed that biochar addition could increase the relative abundance of Bacteroidetes, Chloroflexi, Firmicutes, Proteobacteria, and Spirochaetota, which were associated with the degradation of refractory organic matters. Meanwhile, biochar addition could enrich the relative abundance of methanogens participating in direct electron transfer (Methanosaeta and Methanosarcina), and methanogens producing methane through multiple pathways (Methanobacterium and Methanosarcina). The addition of biochar derived at 700 °C significantly increased the relative abundance of Methanobacterium and Methanosarcina from 1.96% and 0.70% (control group) to 32.68% and 64.69%, respectively and improved methane production by transforming acetoclastic/hydrogenotrophic methanogenic pathways to more metabolically diverse methanogenic pathways.

Rapid assessment of the osteogenic capacity of hydroxyapatite/aragonite using a murine tibial periosteal ossification model

Biomaterials are widely used as orthopaedic implants and bone graft substitutes. We aimed to develop a rapid osteogenic assessment method using a murine tibial periosteal ossification model to evaluate the bone formation/remodelling potential of a biomaterial within 2–4 weeks. A novel hydroxyapatite/aragonite (HAA) biomaterial was implanted into C57BL/6 mice juxtaskeletally between the tibia and tibialis anterior muscle. Rapid intramembranous bone formation was observed at 14 days, with 4- to 8-fold increases in bone thickness and callus volume in comparison with sham-operated animals (p < 0.0001), followed by bone remodelling and a new layer of cortical bone formation by 28 days after implantation. The addition of zoledronate, a clinically-utilised bisphosphonate, to HAA, promoted significantly more new bone formation than HAA alone over 28 days (p < 0.01). The osteogenic potential of HAA was further confirmed by implanting into a 3.5 mm diameter femoral cancellous bone defect in rats and a 5 mm diameter femoral cortical bone defect in minipigs. To understand the biodegradation and the cellular activity at the cell/biomaterial interfaces, non-decalcified specimens were resin embedded and sections subjected to combined scanning electron microscopy (SEM)/electron backscatter diffraction (EBSD)/energy dispersive X-ray spectrometry (EDS) analysis. We conclude that murine tibial periosteal ossification is a novel method for rapid assessment of the interaction of bioactive materials with osteogenic tissues. This study also highlights that combining calcium carbonate with hydroxyapatite enhances biodegradation and osteogenesis.

Enhancing microstructural properties of copper-based composite castings through microwave-assisted reinforcement with MWCNT

An emerging advancement in the field of metallic materials casting is the in-situ microwave casting of metallic materials. To achieve this, the microwave heating process is applied within the applicator cavity, working on the principles of hybrid microwave heating (MHH). This process involves melting the charge, pouring it into an in-situ container, and subsequently solidifying the melted charge. The electromagnetic and thermal properties of the charge influence the interactions between the microwave energy and the material, as well as the melting behavior induced by the microwaves. As for the solidification process, this is also controlled by a cooling condition within the applicator. The present study aims to outline an in-situ casting process for copper-based composite castings fabricated within a multimode cavity, utilizing 900 W at 2.45 GHz. The quality of the developed in-situ cast was assessed by analyzing its characteristics. A microstructural examination revealed that the composite castings exhibited a homogeneous and dense structure. Scanning electron microscopy (SEM) and Energy-dispersive spectroscopy (EDS) analysis was conducted across the casting. The XRD pattern confirmed the presence of major peaks of copper in the composite castings, along with the presence of oxide phases such as Cu64O. Also, the micro indentation hardness of the Cu + 1.5%MWCNT casts was found to be 1.23 times higher than that of microwave-processed pure copper.

Investigating the geomechanical behavior and mechanism of clay stabilization with natural zeolite and nano-magnetite under accelerated curing conditions (ACC)

Chemical stabilization is a commonly used technique for ground improvement. Traditional methods of chemical soil stabilization rely on additives such as cement and lime, which are relatively expensive and not environmentally friendly. Therefore, using accessible natural pozzolans, such as zeolite, in soil stabilization is an effective and economical option. This study investigated the effect of zeolite and nano-magnetite on the geomechanical behavior of fine-grained clayey soil. Unconfined compressive strength (UCS), ultrasonic pulse velocity (UPV), and electrical conductivity (EC) tests were performed on both stabilized and unstabilized samples. The samples were cured under standard curing conditions (SCC) and accelerated curing conditions (ACC). The UCS and UPV results for the clay sample containing 5% zeolite and 1% nano-magnetite showed significant increases of 85% and 48% under SCC and 174% and 59% under ACC, respectively, compared to untreated clayey soil. Additionally, the clay mixture containing 5% zeolite and 1% nano-magnetite, which achieved the highest UCS and UPV values under ACC, exhibited increases of 166 kPa and 100 m/s, respectively, compared to SCC. Moreover, the EC value decreased by approximately 51% and 60% for the samples with the highest strength in SCC and ACC, respectively. Based on Scanning Electron Microscope (SEM) imaging and Energy Dispersive Spectroscopy (EDS) analysis, the impact of zeolite and nano-magnetite on improving compaction and promoting hydrothermal reactions was evident, supporting the higher geomechanical results obtained. Overall, the findings suggest that using zeolite and nano-magnetite offers a cost-effective and eco-friendly solution for stabilizing clayey soil in civil engineering projects.

Oxidative Dissolution Behavior of Synthetic Chalcopyrite with Non-Stoichiometric Compositions

Chalcopyrite (CuFeS2) is the most important Cu mineral, accounting for 70% of copper reserves in the world. Cu metal is primarily produced from chalcopyrite-containing ores by an extraction process involving flotation, pyrometallurgy, and electrorefining. Owing to the ongoing depletion of high-grade ores, hydrometallurgical processes involving copper leaching from chalcopyrite-containing ores using acidic ferric sulfate solutions have been intensively studied. However, efficient copper leaching remains a challenge, and the details of the dissolution mechanism of chalcopyrite in natural resources remain unclear.Investigation using synthetic minerals with controlled compositions and morphologies is an effective approach for understanding the dissolution mechanism. In this study, we prepared dense pellets of synthetic chalcopyrite with stoichiometric and non-stoichiometric compositions and compared their oxidative dissolution behaviors in an acidic ferric sulfate solution.The nominal compositions of the prepared samples are Cu0.250Fe0.250S0.500 (stoichiometric composition), Cu0.240Fe0.260S0.500, Cu0.245Fe0.260S0.495, and Cu0.265Fe0.245S0.490. The powder samples were synthesized via a high-temperature reaction using Cu wire, Fe wire, and S powder as raw materials. The dense pellets (diameter 10 mm and thickness of approximately 3 mm) were obtained by pulse current pressure sintering and subsequent annealing at 500 ℃. Density measurements and scanning electron microscopy observations revealed that the morphologies such as grain size and density of the obtained pellets were almost constant, regardless of the nominal composition. In X-ray diffraction analyses, the diffraction peaks of the obtained pellets were consistent with the chalcopyrite phase (CuFeS2, PDF #00-037-0471). The scanning electron microscopy with energy dispersive spectrometry analysis confirmed that no other phase was detected in the Cu0.250Fe0.250S0.500, Cu0.240Fe0.260S0.500, and Cu0.265Fe0.245S0.490 pellets.To enable electrochemical measurements, dense pellets were cut and embedded in resin after connecting the copper leads. Obtained electrode samples were immersed in 0.1 M Fe(SO4)1.5 – 10−4 M FeSO4 – 0.18 M H2SO4 at 70 ℃ for 24 h. The concentration of Cu ions in the solution was determined by inductivity coupled plasma atomic emission spectrometry and the dissolution rates of the samples were evaluated. The corrosion potentials of the synthesized chalcopyrite samples were also measured. shows the measured dissolution rates and corrosion potentials. The Cu dissolution rates for the chalcopyrite samples with non-stoichiometric compositions (Cu0.240Fe0.260S0.500, Cu0.245Fe0.260S0.495, and Cu0.265Fe0.245S0.490) were over one order of magnitude than those for the samples with stoichiometric composition (Cu0.250Fe0.250S0.500). This result demonstrates that a small difference in composition significantly affects the dissolution rate in the ferric sulfate solution. The corrosion potentials of the electrodes with non-stoichiometric compositions were less noble than those of the stoichiometric composition sample. At the corrosion potential, the rate of anodic dissolution of the chalcopyrite phase was equal to that of the cathodic reaction of the oxidant in the solution (mainly the reduction rate of the Fe(III) species). Considering the shift in the corrosion potential, increasing the dissolution rate is attributed to the enhancement of the anodic dissolution reaction of the chalcopyrite phase by the change in its composition from stoichiometry. Figure 1

Preparation of Bouligand biomimetic ceramic composites and the effect of different fiber orientations on mechanical properties

The multilevel helical arrangement of the Bouligand structure endows it with excellent mechanical properties when subjected to external stresses. In this study, Al2O3 ceramic scaffolds with Bouligand structures incorporated with continuous carbon fibers were prepared using vat photopolymerization (VPP) 3D printing technology. A series of biomimetic Bouligand–ceramic matrix composites with different fiber orientations were prepared using the epoxy penetration method. The flexural strength, fracture toughness, and work of fracture of the composites were evaluated at different fiber initiation and rotation angles. The effects of different fiber arrangements on the crack extension mode of the composites were revealed using the finite element method and peridynamics dynamics simulations. Molecular dynamics simulations, scanning electron microscopy, and energy-dispersive spectroscopy analyses revealed the material microstructure and interfacial bonding properties. The experimental results indicated that a specific combination of initiation and rotation angles can effectively promote crack twisting during the fracture process, thereby increasing the dissipation of fracture energy in the part and improving its fracture toughness. In this study, additive manufacturing technology was used to overcome the challenges of fabricating complex bionic structures through a simple and flexible production process. This method provides a practical solution for the development of lightweight, high-strength, and high-toughness bionic materials.