Heat Treatment Research Articles

Dry solidification of chloride salts and heavy metals in waste incineration fly ash by mayenite.

There are hazardous substances such as chloride salts and heavy metals in the municipal solid waste incineration fly ash (WIFA). During thermal treatment, the concentrated chlorides promote the volatilization of heavy metals, increasing the ecological risk. The water washing method is also employed as a pre-treatment for WIFA, but a substantial volume of wastewater with high chloride content is produced that poses challenges for effective treatment. This study integrates chemical stabilization with heat treatment method and suggests the utilization of a calcium aluminum oxide-mayenite (CA) for the solidification of chloride salts and heavy metals in WIFA. The experimental results indicate that adding CA for heat treatment has a significant solidification effect on chlorides. Under the conditions of WIFA: CA mass ratio of 1: 1 and temperature of 1200°C, the chloride ions were solidified by forming Ca12Al14O32Cl2, with a fixation efficiency of up to 85%, and most of the chlorides in WIFA became insoluble instead of soluble. Most of the heavy metals in WIFA were immobilized and doped into the crystal structure of CA, forming the catalytic metal-rich Ca12Al14O32Cl2 phase, which was subsequently applied to the degradation of chlorobenzene. Under an initial concentration of 512ppm, the degradation efficiency of chlorobenzene reached 50.4%. Through the introduction of CA, not only the solidification of chloride and heavy metals is achieved, but the high-value resource utilization of the final heat treatment product is also realized, providing a new method for the disposal of fly ash.

Enhancing Cyclability of Fe2O3-V2O5-P2O5 Ceramic Cathode for High-Performance Sodium-ion Batteries through Heat Treatment

Due to the ability to form more open structures, glass and glass-ceramic materials can accommodate larger Na+ ions and enable rapid solid-state diffusion of Na+ at room temperature (RT). Regardless of the larger ionic radius of Na, iron-based mixed-vanadium-phosphate ceramics show promising potential as cathode materials in sodium-ion batteries (SIBs). However, their practical applicability is significantly hindered by slow Na+ diffusion and low intrinsic electrical conductivity. In the present study, a ceramic sample with the composition of 5Na2O−45Fe2O3−10V2O5−40P2O5, denoted as (5NFVP), was synthesized before (BHT) and after heat treatment (HT) at 500, 600, and 700 °C for 2h to be used as a cathode material in SIBs. The outstanding electrochemical performance of the 5NFVP ceramic is attributed to improved electronic and ionic conductivity and enhanced structural stability during Na+ insertion/de-insertion. This is supported by various analyses, including X-ray diffraction (XRD), X-ray absorption near edge structure (XANES), 57Fe Mössbauer spectroscopy, and electrochemical impedance spectroscopy (EIS). All prepared samples show two doublets, with the first doublet associated with Fe3+(Td), confirming the XRD results that indicate the main crystalline phase of FePO4. The second doublet observed in the 5NFVP-HT500 and 600°C is related to Fe3+(Oh), while 5NFVP-BHT exhibits a large δ value of 1.19 mm s−1, indicating the presence of Fe2+(Oh) due to NaFePO4 crystalline phase. The Fe-K absorption edge analysis reveals that 5NFVP-HT600°C ceramics predominantly consist of Fe3+, whereas 5NFVP-BHT has the most abundant Fe2+ compared with HT samples. The largest DC conductivity is achieved by the 5NFVP-HT600°C ceramic, reaching 5.08×10−9S cm−1 at RT. The initial capacity of 5NFVP-HT ceramics is approximately doubled compared to 5NFVP-BHT. The 5NFVP-HT600°C ceramic as a cathode demonstrates excellent long-cycling stability, retaining 60 % of its capacity over 100 cycles under a current rate of 50 mA g−1. These findings underscore the significant potential of 5NFVP-HT600°C for advanced energy storage systems, given its affordability and robust cyclability.

Gum arabic-stabilized emulsion systems: Underlying mechanisms for enhancing storage and digestion stability of curcumin.

Although the benefits of gum arabic (GA) in developing emulsion systems are well known, the mechanism underlying its stability-enhancing effect of GA in emulsion systems stabilized with curcumin remains unclear. This study used GA-stabilized emulsion system, containing 10wt% medium-chain triglycerides and 0.1% curcumin. Results demonstrated that when the GA concentration exceeded 0.5wt%, the interface layer reached saturation, maintaining a consistent thickness of approximately 34.8nm. The curcumin-containing emulsion demonstrated good stability during storage at room temperature and heating treatment, effectively protecting the curcumin. However, during in vitro intestinal digestion, the formation of salt and protein bridges caused the aggregation of oil droplets, resulting in an increase in the droplet size to 975.2nm, while the curcumin content remained stable. Additionally, the in vitro release rate of encapsulated curcumin (44.0%) was significantly higher than that of free curcumin (19.5%). In conclusion, this study elucidated the stability-enhancing mechanism of GA-stabilized emulsions for curcumin and highlighted the potential of GA in developing emulsion systems for the encapsulation of these compounds.

Probiotic and postbiotic interference exhibit anti-adhesion effects against clinical methicillin-resistant Staphylococcus aureus (MRSA) and impede MRSA-induced intestinal epithelial hyper-permeability in HT-29cell line.

This study investigates the dynamics of MRSA de-colonization on HT-29cell line using effective strategies like probiotics and postbiotics. Exploring novel alternatives to combat infections caused by antibiotic-resistant pathogens is an urgent need. Harnessing the antagonistic properties of live probiotics and their heat-killed preparations (postbiotics) to curb the growth of AMR pathogens represents a promising and essential area of contemporary research. This study was designed to evaluate the anti-adhesion properties of indigenous probiotics (Limosilactobacillus fermentum Lf1 and Lactiplantibacillus plantarum A5), as well as standard reference strains (Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus NCFM), and their heat-killed postbiotic preparations against clinical MRSA isolates (MRSA12/206 and 5/255) on the HT-29cell line. ATR-FTIR-based functional group characterization of the postbiotic preparations revealed the heat-induced alterations in cell surface molecules and architecture. Both probiotic and postbiotic preparations were non-cytotoxic to HT-29cells. The probiotic intervention, via protective, competitive, and displacement modes, significantly (p<0.05) reduced the adhesion of MRSA isolates to HT-29cells, with the protective and competitive modes showing greater efficacy. In contrast, heat-killed probiotics demonstrated notable anti-MRSA adhesion effects across all three modes (protective, competitive, and displacement). In comparison, heat-killed cells exhibited a superior anti-adhesion capability compared to live cells, likely due to the enhanced accessibility of microbe-associated molecular patterns and adhesion sites following heat treatment. Furthermore, co-treatment of MRSA with probiotic strains substantially (p<0.05) reduced FITC-dextran transflux across the HT-29cell monolayer. In conclusion, this study highlights the superior anti-adhesion efficacy of heat-killed postbiotics over live probiotic cells against MRSA isolates. It underscores the further need for pre-clinical and in-vivo investigations to validate the anti-MRSA colonization and gut barrier prophylactic or therapeutic potential of the investigated probiotics and postbiotics. Thus, the present study documents and supports the alternative to antibiotics potential of probiotics and postbiotics.

Durable superhydrophobicity-memory coating with femtosecond laser-structured micro/nanostructures for anti-corrosion applications.

Superhydrophobic coatings have important application potential and value in the field of metal corrosion protection. However, the practical application of the superhydrophobic coating is significantly hindered by their poor durability. In this study, a durable superhydrophobic coating with repairable micro/nanostructures is prepared by femtosecond laser directly writing micropillar structures on the surface of thermal-responsive shape-memory materials. The resultant superhydrophobic coating has excellent structural recovery function against mechanical pressing or scratches due to the unique shape-memory ability of the coating. Apart from the healing property, the superhydrophobic coating also has remarkable durability against 400 cycles of tape peeling, 3kg water flow impact, 250cm sandpaper abrasion, and immersion in solutions with different pH values for 48h. This durable superhydrophobicity-memory coating can effectively protect metals from corrosion damage. Take the example of Mg alloy, the low-frequency impedance moduli of the coated sample can be increased by 10 orders of magnitude compared to bare Mg alloy. The coating is able to maintain superhydrophobicity even after being immersed in corrosive solution for 107days. Moreover, the anti-corrosion property of the coating after mechanical damage can also be recovered by heating treatment. It is anticipated that this durable superhydrophobicity-memory coating prepared in this study can provide important theoretical value and reference basis for promoting the application of superhydrophobic coatings in the field of corrosion protection.

The Biological Properties of Co-Doped Monetite Are Influenced by Thermal Treatment.

Calcium phosphates, notably monetite, are valued biomaterials for bone applications owing to their osteogenic properties and rapid uptake by bone cells. This study investigates the enhancement of these properties through Cobalt doping, which is known to induce hypoxia and promote bone cell differentiation. Heat treatments at 700°C, 900°C, and 1050°C are applied to both monetite and Cobalt-doped monetite, facilitating the development of purer, more crystalline phases with varied particle sizes and optimized cellular responses. Comprehensive physicochemical characterization through XRD, FTIR, Raman, SEM/EDS, and ASAP analyses shows significant phase transformations into pyrophosphate, influencing the materials' structural and functional attributes. When utilized to condition a culture medium for MC3T3-E1 cells, these materials demonstrate non-cytotoxic behavior and provoke specific gene responses associated with the osteoblastic phenotype, angiogenesis, adhesion, and extracellular matrix remodeling. Significantly, non-heat-treated Cobalt-doped Monetite retains properties advantageous for clinical applications such as dental and orthopedic implants, where lower processing temperatures are crucial. This attribute, combined with the material's straightforward production, highlights its practicality and potential cost-effectiveness. Further research is essential to assess the long-term safety and efficacy of these materials in clinical settings. Our findings underscore the promising role of Cobalt-doped Monetite in advancing bone repair and regeneration, setting the stage for future innovations in treating bone lesions, enhancing implant integration, and developing advanced prosthetic coatings within the field of tissue engineering.

Mechanism of microstructure and properties evolution of 2195 Al-Li alloy during radial-direction hot compression and heat treatment: Determined by shape, size and rotation of grains

Mechanism of microstructure and properties evolution of 2195 Al-Li alloy during radial-direction hot compression and heat treatment: Determined by shape, size and rotation of grains

Three-Dimensional Array of Holey Graphene as a High-Performance Anode Material for Supercapacitors

Herein, a novel method is employed for the facile, and low-cost preparation of three-dimensional holey graphene (3DHG) starting from pristine graphite for supercapacitor applications. 3D nanopatterning of the holey graphene (HG), prepared via a jaggery-assisted ball mill exfoliation of graphite, is achieved here via heat treatment with urea, where the decomposition of urea causes more nanoholes on the graphene sheets. The structural and morphological analyses reveal the edge functionalization, less-defective nature, and extensive nanopores on graphene. Use of 3DHG as a supercapacitor electrode material is investigated and a high specific capacitance of 423 F/g (@3 A/g) is observed. The symmetric coin cell supercapacitor fabricated using the 3DHG delivers high energy density (7.5 Wh/kg), power density (106 W/kg), and long durability (100% capacitance retention after 8000 cycles). Furthermore, the asymmetric assembly with 3DHG as the anode material with HG cathode exhibits a higher cell voltage of 1.6 V, which diminishes the voltage limitation of aqueous electrolyte-based supercapacitors. The present study demonstrates exceptional supercapacitor performance of 3DHG architecture adequate for commercial energy storage applications.

Achieving property differentiation and enhanced strength-plasticity in tailor rolled blank of aluminum alloy by variable gauge rolling and heat treatment

Achieving property differentiation and enhanced strength-plasticity in tailor rolled blank of aluminum alloy by variable gauge rolling and heat treatment

Separation of valuable materials from spent lithium-ion battery based on granulation regulation.

Recycling of spent lithium-ion batteries has attracted worldwide attention to ensure sustainability of electric vehicle industry. Pretreatment as an essential step for recycling of spent LIBs is critical to ensure the recovery efficiency and quality of black mass which is used for further materials regeneration. Usually, high temperature pyrolysis, at around 600°C is required during the pretreatment to achieve effective separation of the black mass that is binding on aluminium foils with polyvinylidene fluoride binder. In this research, a low temperature and energy effective method is demonstrated by introducing a controlled frictional granulation in the subsequent step. With heat treatment at below 300 ℃, the oxidation of aluminium foil and generation of fluorine-containing waste gas can be highly supressed. As a consequence, the recovery rate of black mass can be increased to 98.80% with only 0.05% Al loss. Compared with the high-temperature pyrolysis and shear crushing methods, the energy consumption was significantly reduced by 48.74%. Additionally, the proportion of aluminium particles below 75μm was reduced from 12.6% to 1.9% comparing with traditional high temperature pyrolysis, which eliminates the possibility of explosion of aluminium particles. This research provides a low-carbon footprint strategy for treatment of complex electronic waste.

Recent drying technologies used for drying poultry litter (principles, advantages and disadvantages): A comprehensive review.

Wet poultry litter creates an environment that accelerates the growth of bacteria and pathogens, leading to increased ammonia release. A practical way to reduce these adverse effects is heat treatment (drying). This work evaluated different methods for poultry litter drying and presented their principles, advantages, and disadvantages. Oven dryers are not recommended for continual drying due to their low energy efficiency, but decreasing water activity can prevent microbial growth. Rotary dryers provide homogeneous drying, but they are not suitable for drying fragile materials. Freeze drying preserves heat-sensitive ingredients, but the drying duration is high and classified as a high-cost drying technique. Microwave drying technology surpasses conventional methods in achieving both high product quality and energy efficiency. Solar drying emerges as the most economically viable, practical, and environmentally sound method for poultry litter desiccation. However, improperly controlled mass and heat transfer throughout the drying process can compromise product integrity. The use of combined dryers has not been thoroughly evaluated, although they may be more effective due to their synergistic results. This study is helpful for researchers who aim to reduce the adverse effects of poultry litter and manage it more effectively using heat treatment methods.

Effect of sample thickness and heat treatment on microstructure and mechanical properties of Ti-6Al-4V fabricated using laser powder bed fusion

Effect of sample thickness and heat treatment on microstructure and mechanical properties of Ti-6Al-4V fabricated using laser powder bed fusion

Synergistic effect of naringenin and mild heat for inactivation of E. coli O157:H7, S. Typhimurium, L. monocytogenes, and S. aureus in peptone water and cold brew coffee.

This study aimed to investigate the bactericidal effect of naringenin (NG), a plant-derived flavonoid, and its synergistic effect with mild heat (MH) treatment at 50°C in peptone water (PW) and ready-to-drink cold brew coffee (RDC). Among various NG concentrations (1-20mM), 10mM NG resulted in the greatest inactivation for Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus. In RDC, NG+MH treatment resulted in a 5-8-log reduction in all pathogens after 10min, except for S. aureus. In contrast, NG or MH treatment alone exhibited only marginal bactericidal effects. From inactivating mechanism analysis, lipid membrane destruction and intracellular enzyme inactivation were the key factors for pathogen inactivation. Cell membrane and enzyme dysfunctions were identified in propidium iodide (PI) uptake test, membrane potential assay, and membrane protein analysis. Furthermore, NG+MH exerted minimal influence on the quality attributes of RDC in pH, color, and total phenolic content. These results indicated that the NG+MH treatment system effectively ensured microbial safety in cold brew coffee while enhancing its nutritional value and preserving quality attributes.

Design and preparation of Ti-6Al-1.7Fe-0.1Si-7.3Cr alloy with excellent tensile properties

A novel Ti-6Al-1.7Fe-0.1Si-7.3Cr alloy was designed using high-throughput diffusion couple technique. The heat treatment effects on the microstructure and tensile properties of the designed alloy was investigated. The results indicated that the alloys after solution treatment at 800 °C/840 °C and aging at 400 °C/470 °C exhibited high strength ( > 1200 MPa ) and good ductility ( > 5% ) due to the synergy of spherical αp phase, coarse flake αp phase and acicular αs phase in the β matrix. The precipitation of TiCr2 Laves phase at aging temperatures above 540 °C led to a decline in ductility. The absence of the spherical αp phase for the alloy after solution treatmen at 920 °C also resulted in the deterioration of aging elongation. Good balances of strength and ductility were achieved for the alloys after solution treatment at 840 °C and aging at 400°C/470 °C, with the ultimate tensile strength and tensile elongation of 1237 MPa/23.3% and 1753 MPa/5.1%, respectively. Furthermore, the deformation mechanism of the alloys was analyzed, and dislocation slip in αp phase and β grain was demonstrated to be the main plastic deformation mode.

Effect of heat treatment on structural and magnetic features of nanostructured Ni-Co-Mn-Al Heusler alloy obtained by planetary ball mills

Effect of heat treatment on structural and magnetic features of nanostructured Ni-Co-Mn-Al Heusler alloy obtained by planetary ball mills

Investigation into magnetocaloric effects and critical behavior of La0.65Ca0.35-Ba MnO3(x = 0,0.1,0.2,0.3) prepared by high-pressure heat treatment

Investigation into magnetocaloric effects and critical behavior of La0.65Ca0.35-Ba MnO3(x = 0,0.1,0.2,0.3) prepared by high-pressure heat treatment

Multifunctional Bamboo-Derived Porous Carbon for Efficient Electrical-Thermal Energy Management and Electromagnetic Interference Shielding

Joule heating is an effective heating method but is often limited by the extra heat dissipation. To address this, we developed bamboo-derived porous carbon (CB) for use as Joule heaters, which exhibits remarkable electrothermal conversion efficiency, driven by its high electrical conductivity and porous structure. The natural porous structure of bamboo reduces electrothermal conversion losses, allowing for a steady-state saturation temperature of 164 °C at 2 V. The microcrystalline graphite structure, 3D microporous channels, and low thermal conductivity (0.03 W m-1 k-1) contribute to an electrothermal conversion efficiency of 99.14%. Moreover, CB heaters demonstrate remarkable surface heating and cooling rates of 114.36 °C/min and 113.78 °C/min, respectively. CB Joule heaters are suitable for de-icing and body-assisted heat treatment at various applied voltages. Its unique gradient porous structure also provides asymmetrical electromagnetic interference (EMI) shielding performance, with high absorption losses concentrated in the sparse inner layer. This sustainable CB material has significant potential for advanced Joule heating and EMI shielding applications.

Identification of characteristic flavor compounds in steamed and baked Hu sheep mutton.

The advancement in heat treatment technology has spurred the innovation of various smart cooking appliances, including the steam roaster. Consequently, the technique of synchronized steaming and baking has emerged as a novel form of thermal processing. Therefore, the effects of baking, steaming, steaming-baking heating modes on the flavor of Hu sheep mutton were evaluated. Main sensory descriptors were identified by descriptive sensory analysis. The results showed that SMM presented a relatively strong muttony profile, BKM presented a pronounced profile of burning, smokiness, and baking, while the flavor of SMM was situated intermediary between these two profiles. By SPME-GC-MS, 28 volatile chemicals with OAV > 1 were found. The correlation network analysis revealed relationships between the aroma compounds and sensory descriptors, namely "smoky and baked" (2,5-dimethylpyrazine, dimethyl trisulfide), "muttony" (hexanal, 2-heptenal), "fatty" ((E)-2-octenal), "meaty" (1-octen-3-ol), "burned" and "greasy" (3-methylthiopropionaldehyde, dimethyl disulfide). Meanwhile, analysis of 5'-nucleotides and FAAs revealed 8 characteristic taste compounds with TAV > 1. Moreover, multivariate analysis showed that 2-pentylfuran, E-2-octenal and 2-heptenal, 2,5-dimethylpyrazine might contribute more to the flavor of steamed-baked, steamed, baked Hu sheep mutton, respectively.

Development and post-process heat treatment of dissimilar steel structure via twin-wire arc additive manufacturing using heterogeneous functionally graded deposition strategy

Development and post-process heat treatment of dissimilar steel structure via twin-wire arc additive manufacturing using heterogeneous functionally graded deposition strategy

Determination of hepatitis E virus inactivation during manufacturing of spreadable pork liver sausage and salami-like raw pork sausage.

The zoonotic hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Meat from domestic pigs, which represent a major animal reservoir of HEV, plays a key role in HEV transmission. Although pork meat products can contain HEV-RNA, it is unknown whether infectious HEV is still present after their manufacturing process. Here, we used a newly developed method for virus extraction from sausages and a quantitative method for detecting HEV infectivity in artificially contaminated sausages to investigate the HEV inactivation during production of spreadable pork liver sausage and salami-like raw pork sausage. The cell culture-adapted HEV genotype 3c strain 47832c was used to contaminate meat preparations intended for production of sausages, which were manufactured based on recipes commonly used in Germany. According to these recipes, spreadable liver sausages of a certain diameter are to be held in a water bath at 70°C for 30min. Therefore, the HEV inoculated liver sausage preparations were filled into conical tubes and heated in a 70°C water bath. After 21min, the sausages reached a core temperature of 70°C and samples were taken after further incubation for up to 18min. For the raw sausages, the HEV inoculated meat preparation was filled into natural casings and sausages were cured at 18°C and 80% relative humidity. Samples were taken for up to 21days. HEV was extracted from all samples, which were quantitatively analyzed for infectious virus and viral RNA using cell culture and RT-qPCR, respectively. During liver sausage production, infectious HEV decreased by four log10 immediately after reaching the core temperature of 70°C and was completely inactivated (>4.3 log10 decrease) 2min later (23min heat treatment). In contrast, the HEV-RNA amount decreased only marginally (<0.6 log10) throughout the whole incubation time. During raw sausage manufacturing, infectious HEV decreased only slightly (<1.3 log10) over three weeks of curing, while the HEV-RNA amount remained unchanged. It can be concluded that the intended heating regime during production of spreadable liver sausages leads to an inactivation of HEV, indicating a low risk of HEV infection for consumers if these sausages are manufactured properly. In contrast, HEV was only slightly inactivated during production of salami-like raw pork sausage. Therefore, raw sausage can contain infectious HEV if starting material with a high HEV amount was used for production. Viral RNA testing cannot be used to predict infectivity of HEV in meat products.