Heat Treatment Research Articles

Enhancement of the Photoluminescent Intensity of YVO4: Er, Yb UCNPs Using a Simple Coprecipitation Synthesis Method.

Yttrium vanadate (YVO4) is a non-toxic ceramic matrix that, when doped with lanthanides, can be used as a photoluminescent biosensor. In this study, we meticulously synthesized upconversion nanoparticles (UCNPs) of YVO4 via chemical coprecipitation, using Er3+ and Yb3+ ions for codoping. The light emission achieved through upconversion mechanisms enables the excitation of nanoparticles with infrared light rather than ultraviolet light, enhancing the potential of current bioimaging techniques. The light emission intensity of our YVO4: Er, Yb UCNPs, a key factor in their effectiveness, depended on various easily adjustable factors during the synthesis, such as the dopant concentration, the heat treatment, and the cleaning process. The UCNPs were characterized using a range of advanced techniques, including X-ray diffraction (XRD) and Rietveld refinements, as well as Raman, photoluminescence (PL), and ultraviolet-visible (UV-vis) spectroscopies, and high-resolution transmission electron microscopy (HRTEM). We found the most convenient stoichiometry to obtain the YVO4: Er, Yb UCNPs and showed that a rigorous thermal treatment was necessary to achieve light emission through upconversion mechanisms. We also discovered that some porosity characteristics can be promoted in the YVO4: Er, Yb UCNPs during the cleaning process, depending on the solvent employed. The porosity and morphology of the nanoparticles could be predicted using the microstrain values obtained from the refinement of the crystalline structures. All these meticulous steps in our research have enabled us to develop an efficient synthesis pathway to produce YVO4: Er, Yb UCNPs with high photoluminescent intensity.

Residual Stress Homogenization of Hybrid Implants

Objectives: Hybrid implants commonly exhibit decreased corrosion resistance and fatigue due to differences in compressive residual stresses between the smooth and rough surfaces. The main objective of this study was to investigate the influence of an annealing heat treatment to reduce the residual stresses in hybrid implants. Methodology: Commercially pure titanium (CpTi) bars were heat-treated at 800 °C and different annealing times. Optical microscopy was used to analyze the resulting grain growth kinetics. Diffractometry was used to measure residual stress after heat treatment, corrosion resistance by open circuit potential (EOCP), corrosion potentials (ECORR), and corrosion currents (ICORR) of heat-treated samples, as well as fatigue behavior by creep testing. The von Mises distribution and the resulting microstrains in heat-treated hybrid implants and in cortical and trabecular bone were assessed by finite element analysis. The results of treated hybrid implants were compared to those of untreated hybrid implants and hybrid implants with a rough surface (shot-blasted). Results: The proposed heat treatment (800 °C for 30 min, followed by quenching in water at 20 °C) could successfully homogenize the residual stress difference between the two surfaces of the hybrid implant (−20.2 MPa). It provides better fatigue behavior and corrosion resistance (p ˂ 0.05, ANOVA). Stress distribution was significantly improved in the trabecular bone. Heat-treated hybrid implants performed worse than implants with a rough surface. Clinical significance: Annealing heat treatment can be used to improve the mechanical properties and corrosion resistance of hybrid surface implants by homogenizing residual stresses.

Enhanced Platinum-Based Thin-Film Catalysts for Electro-Oxidation of Methanol

Surface morphology is one of the critical factors affecting the performance of electrocatalysts. Thus, with careful manipulation of the surface structures at the atomic level, the effectiveness of the catalyst can be significantly improved. Heat treatment is an effective method for inducing surface atom rearrangement, hence modifying the catalyst’s characteristics. This study investigated the substrate’s influence and the effect of thermal annealing on the morphology and surface reconstruction of platinum (Pt) thin-film catalysts. Our findings indicate that heat treatment in a reductive atmosphere (95% Ar + 5% H2) at 300 °C can significantly impact the degree of rearrangement of surface atoms. This process induces long-range ordering, resulting in domains with a high proportion of (111) and (100) sites without an epitaxial template. Considering that the reactivity of low-index platinum single crystals for the methanol oxidation reaction follows the following sequence Pt(111) < Pt(110) < Pt(100), increasing the proportion of (100) planes leads to a notable enhancement (up to three times) in performance, compared to untreated catalysts. Furthermore, considering the amount of precious metal consumed, a mass-specific current density obtained on annealed Pt@Ni is larger by one order of magnitude and ~2 times that obtained on Pt@Cr and Pt@GCox catalysts, respectively. Our results demonstrate that an easy-to-implement way of controlling atomic orientations improves catalyst performance. With this contribution, we propose a method for designing improved electrocatalysts, as catalytic reactions occur only at the surface.

Effects of Al Substitution for Fe in Na₅FeSi₄O₁₂ (5.1.8) Glasses: Structure and Crystallization

In this study, the effects of substituting Al for Fe in 5Na2O∙(Al2O3)x∙(Fe2O3)1-x∙8SiO2 glass, x=0 to 1, and Na5AlxFe1-xSi4O12 (5.1.8) crystal, were investigated using thermal analysis, Fe K-edge X-ray absorption, X-ray diffraction, Raman spectroscopy, and Electron Probe Microanalysis. In both glass and crystallized glass, nearly all the Fe was tetrahedrally coordinated Fe3+, as expected from the high concentration of Na2O. The substitution of Al for Fe in the glasses caused the glass transition temperature to increase as polymerization increased, as evidenced by Raman, likely due to both field strength differences of Al vs Fe and a small amount of Fe2+ network modifier present with Fe. After heat treatment at 700 °C for 24 hours, the glasses had crystallized, forming Na2SiO3 and NaAlSiO4 in compositions with high Al concentrations and the 5.1.8 crystal in compositions with high Fe concentrations. Through electron microprobe, it was determined that <0.04 formula unit Al incorporated into the 5.1.8 crystal, i.e. Na5Fe0.96Al0.04Si4O12. The 5.1.8 crystal only formed when Fe concentration was higher than Al in the starting glass.

Technical note: Effects of chemical, radiational, and thermal treatment of bone tissue on material stiffness and anisotropy.

We evaluated the effects of four treatments for pathogen inactivation in bone tissue (ethanol storage, formalin fixation, gamma irradiation, and heat treatment via autoclave) on stiffness and anisotropy values in bone samples. Cortical bone samples from the humerus of 14 bovine specimens were subjected to Knoop microindentation analysis in longitudinal and transverse planes of section and four indenter orientations within each section. From each specimen, individual samples were assigned to one of five treatment conditions: 50% ethanol-saline solution, formalin immersion, gamma irradiation, autoclave, and buffered saline (controls). Each sample was microindented 100 times and the resultant stiffness data were analyzed by a resampled factorial analysis of variance. First- and second-order interactions as well as main effects of indenter orientation, treatment, and specimen were significant for both transverse and longitudinal sections, with the sole exception that indenter orientation-treatment interaction was nonsignificant for longitudinal sections. Interaction plots reveal that thermal (autoclave) and irradiation treatments depress stiffness values the most, while patterns of indentation stiffness at different orientations are relatively unaffected. Patterns of anisotropy are relatively unaffected by preservative treatments, but elastic modulus changes are consistent and unambiguous. Formalin and ethanol treatments are most comparable to controls and represent the best preservative media for mechanical testing. These options, however, are likely to be the least effective for ensuring the inactivation or sterilization of potentially contaminated samples.

The effect of post-bond heat treatment on microstructure and mechanical properties of a two-step heating transient liquid-phase bonding IN738LC

ABSTRACT This study evaluated the bonding of a Ni-based superalloy, Inconel 738LC, using two-step heating and conventional TLP bonding techniques using a foil of BNi-2 filler alloy with a thickness of 70 μm. The bonds were processed. The first step at 1160 °C for 1 min and the second step at 1120 °C for different isothermal solidification times (50, 65, 80, and 95 minutes), and the conventional TLP process at 1120 °C for 80 min. It was inferred from the results of microstructural examinations that the joints contained eutectic product constituents that formed an athermal solidified zone (ASZ) during the bonding time of 50 min. It was also found that 80 min was required to complete isothermal solidification in the two-step TLP bonding employed in this study, whereas isothermal solidification was incomplete in conventional TLP for 80 min. The time necessary to complete the isothermal solidification was lowered using two-step TLP bonding. The microstructure after being subjected to a two-stage postbond heat treatment, becomes close to the base metals. As a result, homogenizing microstructure forms throughout the joint. The heat-treated sample contained a much greater amount of the γ′ phase generated at the bond location, resulting in increased shear strength and hardness of the bond.

Influence of Solid Solution Treatment on Microstructure and Mechanical Properties of 20CrNiMo/Incoloy 825 Composite Materials

The utilization of 20CrNiMo/Incoloy 825 composite materials as high-pressure pipe manifold steel can not only improve the strength and hardness of the steel, but also improve its corrosion resistance. However, research on the heat treatment of 20CrNiMo/Incoloy 825 composite materials is still scarce. Thus, the aim of this study was to investigate the influence of solid solution treatment on the microstructure and properties of 20CrNiMo/Incoloy 825 composite materials. Firstly, the composite materials were subjected to solid solution treatment at temperatures ranging from 850 to 1100 °C with varied holding times of 1 h, 4 h, and 6 h. Microstructural analysis revealed that the solid solution treatment temperature had a more pronounced effect than the treatment time on the interface decarburization layer, carburization layer, and grain size. It was observed that the carburized layer thickness decreased while the decarburized layer thickness increased with an increase in the solid solution treatment temperature, oil cooling was found to enhance the hardness of the base layer of the composite materials, and the size of the original austenite grains of 20CrNiMo steel and Incoloy 825 increased with an increase in the solid solution treatment temperature. Secondly, the tensile properties, microhardness, and fracture morphology were evaluated after the composite materials underwent solid solution treatment at temperatures between 950 °C and 1100 °C for 1 h. The results indicated that increasing the solution temperature initially led to an increase in tensile strength and elongation after fracture, followed by a decrease; furthermore, the hardness of Incoloy 825 exhibited a declining trend, while the hardness of 20CrNiMo first decreased then increased. Thirdly, the shear properties and interfacial element diffusion of the composite materials were analyzed following solid solution treatment in a temperature range of 950 °C to 1100 °C for 1 h. The findings demonstrated that higher solid solution treatment temperatures induced full diffusion of Cr, Ni, and Fe atoms at the interface and softened the matrix, leading to an increase in the thickness of the diffusion layer and toughening of the composite interface. Therefore, the shear strength increased with an increase in the solid solution treatment temperature. Finally, the optimal solid solution treatment process for 20CrNiMo/Incoloy 825 composite materials was determined to be 1050 °C/1 h oil cooling, following which the composite materials had good comprehensive mechanical properties.

Impacts of Climate Change-Induced Temperature Rise on Phenology, Physiology, and Yield in Three Red Grape Cultivars: Malbec, Bonarda, and Syrah

Climate change has significant implications for agriculture, especially in viticulture, where temperature plays a crucial role in grapevine (Vitis vinifera) growth. Mendoza’s climate is ideal for producing high-quality wines, but 21st-century climate change is expected to have negative impacts. This study aimed to evaluate the effects of increased temperature on the phenology, physiology, and yield of Malbec, Bonarda, and Syrah. A field trial was conducted over two seasons (2019–2020 and 2020–2021) in an experimental vineyard with an active canopy heating system (+2–4 °C). Phenological stages (budburst, flowering, fruit set, veraison, harvest), shoot growth (SG), number of shoots (NS), stomatal conductance (gs), chlorophyll content (CC), chlorophyll fluorescence (CF), and water potential (ψa) were measured. Additionally, temperature, relative humidity, light intensity, and canopy temperature were recorded. Heat treatment advanced all phenological stages by approximately two weeks, increased SG and NS, and reduced gs and ψa during the hottest months. CC and CF remained unaffected. The treatment also resulted in lower yields, reduced acidity, and increased °Brix in both seasons. Overall, rising temperatures due to climate change advance the phenological phases of Malbec, Syrah, and Bonarda, leading to lower yields, higher °Brix, and lower acidity, although physiological variables remained largely unchanged.

Superelastic behavior of novel Ni-Ti-Co shape memory alloys for seismic applications

Abstract Ni-Ti-Co is a new shape memory alloy (SMA) that has higher strength and lower superelastic temperature range than traditional binary Ni-Ti SMA. In this paper, the superelastic properties of Ni-Ti-Co bars that are important for seismic applications were studied and compared with those of Ni-Ti bars. The superelastic behavior, strength, strain recovery, low-cycle fatigue characteristics, and fracture strains of Ni-Ti-Co and Ni-Ti SMA with different heat treatment strategies and testing temperatures from -40℃ to 50℃ were investigated with seismic applications in mind. The effect of low-cycle fatigue loading and temperature variation on the superelasticity degradation of Ni-Ti-Co SMA were evaluated. The results showed that the yield strength of Ni-Ti-Co SMA at room temperature was 1.41 ~ 1.74 times that of the Ni-Ti SMA. Ni-Ti-Co SMA exhibited 100% strain recovery when unloaded from 5% strain in a temperature range from -40℃ to room temperature; while at 50℃, a residual strain of 0.6% was observed when unloaded from 5% strain. For comparison, the Ni-Ti SMA lost superelasticity when the temperature was reduced to 0℃. When subjected to low-cycle fatigue loading, the stability of the superelasticity behavior (maintaining yield stress, energy dissipation and strain recovery) of Ni-Ti-Co SMA at -40℃ was better than that at room temperature and 50℃. In particular, the superelasticity of Ni-Ti-Co SMA at -40℃ was even superior to that of the Ni-Ti SMA at 0℃. At -40℃, the Ni-Ti-Co SMA showed no loss in yield stress, damping ratio and recovery strain during the first 100 cycles of fatigue loading. Moreover, from 100th to 471st cycle, at which fracture occurred, the strain recovery of Ni-Ti-Co SMA showed almost no degradation.

Influence of Process Conditions During Aqueous and Direct Recycling of NMC811 Cathodes.

This study investigated the impact of various process conditions on the aqueous, direct recycling of LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes. Three model systems were used. The first system assumes that the current collector delamination is performed in a dry environment without the use of water as a process medium. Consequently, the NMC811 is only exposed to water during classification, where no aluminum foil is present. The second model system assumes that the current collector delamination occurs in water. Therefore, the NMC811 is exposed to water in the presence of aluminum foil. Due to the pH increase caused by the Li+/H+ exchange reaction, the pH value surpasses the stability window of the aluminum-oxide passivation layer (pH 4.5-8.5), resulting in the deposition of aluminum-containing species on the NMC811 surface. The third model system is identical to the second, with the exception that H3PO4 is added. This causes the pH to decrease and prevents corrosion of the aluminum foil. The findings reveal that process conditions significantly affect the surface chemistry on NMC811, influencing electrochemical performance. Notably, aluminum-containing species increase polarization. Heat treatment simulating regeneration led to cation mixing as surface species diffused into the NMC811 bulk structure, highlighting the need to control recycling process conditions.

The Thermal Stability of Influenza Viruses in Milk

Highly pathogenic avian influenza viruses (HPAIVs) of the H5N1 subtype (clade 2.3.4.4b) have been detected in raw milk from infected cows. Several studies have examined the time and temperature parameters to ascertain whether influenza viruses in milk can be inactivated completely under commercial pasteurization conditions, yielding conflicting results. This study aimed to investigate whether milk could help protect influenza viruses from heat treatment. After heat treatment at 49 °C for one hour, the titer reduction of the influenza A/WSN/1933 (A/H1) virus in milk was approximately 1.6 log10TCID50/mL, which was significantly lower than that (3 log10TCID50/mL) observed in the Dulbecco’s Modified Eagle Medium (DMEM) control media. The influenza D/bovine/CHN/JY3002/2022 (D/Yama2019) virus in milk retained a high residual infectivity (4.68 × 103 log10TCID50/mL) after treatment at 53 °C; however, the virus in DMEM completely lost its infectivity under the same conditions. Moreover, the influenza A/chicken/CHN/Cangzhou03/2023 (A/H5) virus in DMEM could be inactivated completely using any of the three heat treatment methods: 63 °C for 30 min, 72 °C for 15 s, or 80 °C for 15 s. For the virus present in milk, only heat treatment at 80 °C for 15 s completely inactivated it. These results suggest that milk prevents influenza viruses from pasteurization inactivation.

Non‐Destructive and Mechanical Characterization of the Bond Quality of Co‐Extruded Titanium‐Aluminum Profiles

The transportation industry aims to improve energy efficiency and reduce CO2 emissions, with a focus on reducing vehicle mass. A key method involves advanced lightweight construction techniques using materials like aluminum alloys. Research is concentrated on developing processes to combine different materials into reinforced hybrid components, such as aluminum and titanium. This study focuses on the lateral angular co‐extrusion (LACE) process to produce hybrid hollow profiles of EN AW‐6082 and Ti6Al4V, investigating the impact of the thermomechanical processing during extrusion and heat treatment (HT) on the resulting bond quality and material properties. Various HT routes are tested to see their impact on intermetallic phase formation, longitudinal weld seams, and bonding strength. Mechanical testing evaluates the tensile strength of the joining zone, while nondestructive ultrasonic testing (UT) assesses joining zone integrity and poor bonding detection. Results indicate that HT parameters significantly influence the bond quality and mechanical properties of hybrid profiles. UT data shows a strong correlation with tensile strength and intermetallic phase growth, providing a nondestructive way to evaluate bond quality. This study highlights the potential of LACE processes and optimized HT strategies to improve the performance and reliability of aluminum–titanium hybrid components.

Effect of Precipitation Heat Treatment on a Mechanically Alloyed Al‐Based Composite Reinforced with Metallic Glassy Powder

An Al‐based composite reinforced with titanium‐based metallic glassy particles is synthesized by the powder metallurgy method through mechanical alloying followed by hot extrusion. The effect of precipitation heat treatment on the structure and properties of the composite is studied. During aging of the solution‐treated composite, crystallization of the metallic glassy reinforcement becomes more pronounced as the solutionizing temperature, solutionizing time, aging temperature, and aging time increase. A reaction layer has formed at the interface between the reinforcement and the matrix after the aging treatment. It is found that the addition of metallic glassy particles promotes precipitation of the nanophase in the matrix. With appropriate heat treatment, the compressive strength, yield strength, and fracture strain of the composite have increased to 942, 635 MPa, and 27%, respectively. Herein, it is demonstrated that the mechanical properties of these composites can be further enhanced through an appropriate heat treatment process, thereby having significant potential for a variety of industries, including aerospace, automotive, and defense, where high‐strength, lightweight materials are critical for performance and safety.

Laser Sintering of Metal Powders: Failure Analysis and Implementation of Solutions for Aluminium and Stainless Steel Parts

Abstract In this research, the failures and possible solutions of direct metal laser sintering (DMLS) have been investigated, with the aim of presenting an overview of the current state of science and possible technical solutions to the various challenges and potential solutions. DMLS technology allows to produce high density parts and has proven to be suitable for the cost-effective production of both mass-produced and individual parts in the automotive, aerospace, medical and hydrogen technology industries. This study reveals the fundamental principles, potential benefits, and limitations of metal 3D printing. The defects are categorized into those related to raw materials and those caused by the manufacturing process. The properties of the parts fabricated by this method are mainly depending on the quality of the raw material and the intensity of the laser beam. Clusters of raw materials have a negative impact on the whole manufacturing process, requiring their investigation and avoidance. Another critical defect identified is the significant internal stress generated during the manufacturing process. Various methods are developed to quantify and mitigate these internal stresses. This study provides a detailed analysis of these defects and their impacts, along with a review of literature-based solutions. Among the evaluated and implemented solutions, emphasis is placed on the effects of preheating the build plate and post-process heat treatment. Future objectives and research directions are proposed, presenting and assessing alternative solutions such as Vibratory Stress Relief (VSR) and Thermo-Vibratory Stress Relief (TVSR), which combine heat treatment with vibration. In the scope of the research, the process by which the most common failures occur, and their potential outcomes was reviewed. Special attention was given to deformation caused by internal stress and the possibilities for its mitigation. The feasibility of applying a new approach was investigated, and future research objectives were outlined. SEM imaging was employed to conduct and analyse the grain size of stainless-steel raw material, and agglomerates were observed in the post-print recycled powder.

Elaboration and characterization of Cu–Zn–Al shape memory alloys

AbstractThe study examines Cu–Zn–Al shape memory alloys, vital in aeronautics and automotive sectors. It aims to characterize their thermo-mechanical transformations induced by composition and heat treatments, focusing on how these impact mechanical properties, especially grain size refinement. Analysis covers transformation temperatures, micro-hardness, induced transformations, and mechanical tests. Results show thermoplastic martensitic transformations, with micro-hardness aiding in identifying characteristic points. The study's novelty lies in understanding how grain size refinement affects these transformations and the role of micro-hardness in precise characterization.

A Method of Efficiently Regenerating Waste LiFePO4 Cathode Material after Air Firing Treatment.

Waste LiFePO4 (LFP) batteries can be harmful to the environment and lead to waste of resources if not properly disposed of. In this study, an efficient and environmentally friendly method for solid-phase recycling waste LFP cathode material (W-LFP) is proposed. Most of the impurities in the W-LFP are removed by air firing. The regenerated LFP is then obtained by adding lithium carbonate and triethanolamine for repair during heat treatment. The addition of triethanolamine converts Fe3+ to Fe2+ and also allows the formation of an N-doped modified carbon layer on the surface of the LFP particles, which improves the electrochemical properties of the regenerated material. Physical characterization and electrochemical tests are used to investigate the attenuation and regeneration mechanism of LFP. The regenerated LFP possesses a high specific discharge capacity (152.87 mAh g-1 at 0.2 C), which is about 95.32% of the commercial LFP, and the capacity retention rate is 88.52% after 600 cycles at 1 C. It is worth noting that we do not use solvents such as acids and alkalis in the regeneration process, thus avoiding the generation of large quantities of acid and alkaline waste liquids, which is friendly to the environment. This solid-phase regeneration process offers a promising method for the future recycling of used LFP batteries because of its simplicity, environmental friendliness, and high efficiency.

Impact of Partitioning Temperature Parameters during the Quenching and Partitioning Process on Medium Carbon Steels with Two Different Alloying Strategies

Quenching and partitioning (Q&P) heat treatments have recently gained attention as promising methods for the third generation of advanced high‐strength steels, particularly in industrial applications like automotive. This study investigates the microstructural evolution during Q&P in two medium‐carbon high‐silicon and aluminum‐alloyed steels, exploring potential additional phase transformations controlling the final structure. The choice to focus on Si and Al‐ medium‐carbon steel is linked to the lower cost of these elements compared to commonly alloying elements like Ti, Cr, Mo, and V, while still achieving high mechanical properties through Q&P. The Q&P process is analyzed by varying the volume fraction of primary martensite (M1) at 0.25, 0.50, and 0.75, with partitioning temperatures ranging from 350 to 550 °C for 30 min. At 350 °C, a significant volume fraction of stabilized austenite (up to 0.3) is observed. However, concurrent reactions such as nanostructured bainite and martensite formation lead to deviations from the theoretical constrained carbon equilibrium (CCE). At higher temperatures (450–550 °C), tempering reactions, including cementite precipitation and pearlite formation, reduced the austenite final fraction. The study highlights that heat treatment design, particularly partitioning temperature, must be tailored to the specific steel composition due to the varying effects of Si and Al.

Genome-Wide Identification of Heat Shock Transcription Factor Family and Key Members Response Analysis to Heat Stress in Loquat

Eriobotrya japonica (loquat) is an evergreen fruit tree of the apple tribe in Rosaceae with high edible and medicinal value. The yield and quality of loquat fruits are significantly influenced by environmental stress, particularly heat stress during fruit ripening. In this study, thirty EjHSFs were identified in the loquat genome. Twenty-nine EjHSFs were unevenly distributed across sixteen chromosomes, except Chr-6. A synteny analysis revealed that twenty-six EjHSF genes had undergone duplication events. Twenty-nine EjHSF genes were found to be in sync with HSF in apples while also diverging with other Rosaceae species. A phylogenetic analysis revealed that EjHSFs could be divided into three categories, including eighteen EjHSF-A, ten EjHSF-B, and two EjHSF-C. Twenty-nine members of the EjHSF family showed high homology to those of Malus domestica and Gillenia trifoliate. A promoter analysis retrieved thirty-three CAREs that were functionally relevant and connected to the expression of HSFs. Among these, the promoters of twenty-three EjHSF genes possessed at least one STRE element that could be activated by heat shock. Eleven of these EjHSFs were highly expressed in loquat tissues, namely EjHSF-B4a, EjHSF-A4a, EjHSF-A4d, and EjHSF-C1a in roots; EjHSF-B4b in roots and inflorescence; EjHSF-C1b in stems and roots; EjHSF-A2a in three tissues; EjHSF-A8b in four tissues; and EjHSF-A4c, EjHSF-B1a, and EjHSF-B2b in six tissues. Moreover, fifteen EjHSFs were differentially expressed (eleven upregulated and four downregulated) in fruits under heat stress treatment in the color-changing period. Among them, EjHSF-A2a and EjHSF-A2b upregulated transcriptional abundance over 300 times after heat treatment; EjHSF-B2b consistently displayed an increasing trend over time; and EjHSF-B1a was significantly downregulated. Hence, these results suggest that EjHSFs take part in loquat tissue development and may be involved in the fruit’s heat stress response. These findings enhance the understanding of EjHSFs’ role within loquats and the heat stress response of its fruit and provide target genes for heat stress improvement.

Characterization of Nano Calcium Carbonate Extracted from Eggshells

Organic waste, especially eggshells, represents a valuable resource for the synthesis of calcium carbonate nanoparticles, which have significant industrial and medical applications. This study describes the methodology for converting eggshells into calcium carbonate nanoparticles through heat treatment and nano milling processes. Advanced characterization techniques, including TEM, SEM, and AFM, were used to analyze the morphology and structure of the synthesized nanoparticles. The particles were found to be of nanometer dimensions, with a size of around 150 nm and a distinctive spherical shape, as shown in the TEM images. SEM images showed that the surface of calcium carbonate nanoparticles synthesized from eggshells is smooth, crystalline, and spherical or nearly spherical. FTIR analysis revealed the presence of distinct functional groups for calcium carbonate, with peaks at 713–868 cm⁻¹, consistent with previous studies. The results show that nanoparticles manufactured from calcium carbonate possess unique properties that enhance their applicability in various fields, and promote sustainability and environmental preservation.

Friction stir welding of Haynes 282 Ni superalloy by using a novel hemispherical tool.

In the present investigation, friction stir welding (FSW) of a gamma prime (γ') strengthened Haynes 282 nickel-base superalloy by using a novel hemispherical tool is documented. A joint efficiency of ~ 96% was achieved in the as-welded condition, which further increased to ~ 100% after two-step post-weld aging heat treatment. An extremely fine (~ 2μm) grained microstructure was observed in the FSWed region compared with the coarse (~ 48μm) grain base metal region. The carbides (MC and M23C6) and γ' precipitates are identified as the important microstructural constituent phases observed in the welded region. The aging heat treatment resulted in the precipitation of the γ' strengthening phase and altered the morphology of the M23C6 carbide phase in the welded region from a continuous film to discrete particles at the grain boundaries. The preliminary results concerning tool life suggest that no significant tool wear occurs at least up to a welding distance of 200mm. Therefore, the novel hemispherical tool design allows the successful FSW of high-temperature application materials without any significant tool wear or high heat generation.