Underwent Heat Treatment Research Articles

Electrospun LiCoPO4@C Composite Nanofibers As High-Voltage Cathode Materials for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have revolutionized modern technology with their high energy density allowing longer use in portable electronic devices. Their long cycle life and negligible memory effect further enhance their appeal [1]. However, there are challenges such as lower power density, safety risks including thermal runaway, and an aging effect requiring further development [2].Lithium cobalt phosphate (LCP) offers a possibility of high energy density, owing to its high working potential of 4.8 V vs. Li/Li+ and moderate theoretical capacity of 167 mAh g-1. Furthermore, good thermal stability of LCP can further contribute to the efficient use of LIBs [3]. Despite these advantages, the electrochemical performance of LCP is affected by low ionic and electrical conductivities which cause poor cycle life and rate capability [4]. These limitations could also be accompanied by electrolyte selection and its decomposition at high voltages during delithiation-lithiation of LCP [2] . Thus, this research aims to improve the overall characterizations of LCP@C cathode materials by synthesizing continuous, free-standing nanofibers using the environmentally friendly electrospinning method and implementing nanosize structure enhancing ionic diffusivity [4]. The effect of pre-oxidation temperatures on electrochemical performance of LCP@C cathode materials is studied as well.The electrospinning solution was prepared as previously reported [5] but with a difference of adding a stoichiometric amount of lithium nitrate and electrospun at specified electrospinning parameters. The fibers underwent heat treatment at 700 ℃ in a nitrogen environment after being dried at 150 ℃ and pre-oxidized at various temperatures, indicated in samples’ names. By using scanning electron microscopy (SEM, Crossbeam500, Zeiss) and X-ray diffraction (XRD, Miniflex, Rigaku), the crystal structure and morphology of nanofibers were investigated, respectively.Using CR2032 coin-type cells built in a glove box with 99.9995% pure Ar gas, the electrochemical performance was tested. The cells were equipped with Li chips as reference electrodes, polypropylene separators, ~50 μL of an electrolyte solution comprising 1 M LiPF6 in a mixture of ethylene carbonate and dimethyl carbonate (EC:DMC=1:1 vol.) solvents, and LCP@C composite nanofibers as free-standing cathodes with mass loading of ~2 mg cm-2. At a current density of 0.1 C, the cells were tested in the potential range of 3.5 – 5.3 V vs. Li/Li+. Formation of LCP in the samples have been verified via XRD analysis given in Fig. 1 a, showing a similar pattern for all six samples pre-oxidized at 280-380 ℃. The peak around 22-23 ℃ corresponds to the presence of lithium phosphate for the LCP@C-280 sample. The SEM image in Fig. 1 b shows the formation of nanofibers with beads on materials, the average diameter of fibers is 280-330 nm. Electrochemical performance of prepared LCP@C nanofibers will be presented at the conference. Acknowledgements This research was funded by the projects AP19675260 “Development of nanofibrous electrode materials for next-generation lithium-ion batteries”and AP13068219 “Development of multifunctional free-standing carbon composite nanofiber mats” from the Ministry of Education and Science of the Republic of Kazakhstan.

Effect of glass fiber on the mechanical and thermal insulation performances of kaolinite-based thermal insulator

The development of high-performance thermal insulators is essential for achieving building energy efficiency. The mechanical properties of traditional inorganic porous thermal insulators are not ideal enough. Among various inorganic fiber materials, glass fiber is widely recognized as the most cost-effective option and is expected to significantly enhance the mechanical performance of inorganic porous thermal insulators. The present study employed kaolinite and water glass as primary raw materials, with the addition of glass fiber as a reinforcing material. By means of the chemical foaming method, a kaolinite-based thermal insulator was prepared. The impact of glass fiber on the physicochemical properties of insulator was investigated. The results revealed that the samples containing 15 wt% glass fiber exhibited compressive strength of 1.06 MPa and thermal conductivity of 0.075 W/(m·K), while achieving a remarkable strength-to-density ratio of 4.36. After undergoing heat treatment, the samples exhibited enhanced thermal insulation performance with a reduction in thermal conductivity by approximately 34.2 %. However, the compressive strength showed a significant decline. The samples showcased exceptional thermal insulation capabilities in a simulated high-temperature outdoor environment.

Physical and anatomical characteristics of Bombax ceiba L. wood after undergoing heat treatment

Physical and anatomical characteristics of Bombax ceiba L. wood after undergoing heat treatment

The effect of 3D printing orientation on tensile behaviour and fracture mechanisms of Inconel 718

The manuscript aims to study the effect of 3D printing orientation on the tensile behaviour and fracture mechanisms of samples made of Inconel 718. Components of metals using additive manufacturing techniques are crucial in applications where safety, reliability, and trouble-free operation are essential. Therefore, it is vital to study and understand the behaviour of 3D-printed components under various loading types and predict potential failures. The EOS Nickel Alloy IN718 material sheet provides tensile properties of heat-treated samples (per AMS 5664 procedure) built exclusively in the Z direction. Consequently, the authors extended the investigation to include the tensile behaviour of 3D-printed samples in seven basic orientations within the 3D printing machine’s workspace. For this purpose, the mechanical properties of Inconel 718 alloy samples manufactured using Direct Metal Laser Sintering (DMLS) technology were subjected to uniaxial tensile stress. The samples underwent heat treatment according to the AMS 5664 procedure, with solution annealing and aging temperatures determined using a pseudo-binary phase diagram calculated with Thermo-Calc® software. Post-tensile tests and fracture surface observations were conducted to identify the main failure modes. Microstructural and morphological analyses of 3D-printed INCONEL 718 samples were carried out using light optical microscopy (LOM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) textural analysis. Phase diagrams indicate expected phases such as γ-phase (FCC_A1), δ-phase (NbNi3_D0A), γ’’-phase (Ni3Ti_D024), Laves phase (C14_Laves), and γ’-phase (FCC_L12). Solution annealing was performed above 940 °C while aging treatment was done at temperatures below 800 °C to allow precipitation of γ’ and γ’’ phases. The δ phase also forms during aging. Fractographic examination of the tensile fractures indicated a predominantly quasi-ductile failure mechanism, with fine-sized dimples observed. In the XZ-oriented samples, the measured yield strength was 11 % higher compared to the Z-oriented samples and the yield strength was more than 12 % higher. The difference in mechanical properties between the Z orientation (Rp0.2 = 1284 MPa and Rm = 1429 MPa) and the XZ orientation (Rp0.2 = 1436 MPa and Rm = 1613 MPa) can be mainly attributed to the < 101 > texture in the XZ sample and its more equiaxed grain structure compared to the Z sample.

The Effect of Heat Treatment on the Plasma Nitriding of Hot-rolled 17–7 PH Stainless Steel

17–7 PH stainless steel is a highly versatile material with a multitude of applications in a diverse range of fields, including aerospace, chemistry and petrochemistry, and medicine. The material’s exceptional mechanical properties and corrosion resistance render it the optimal selection for numerous components and instruments. Nevertheless, the surface properties of 17–7 PH stainless steel are inadequate for applications requiring high hardness and wear resistance in certain extreme environments. Due to its excellent mechanical properties and corrosion resistance, it can be utilized in the manufacturing of pharmaceutical equipment components. However, certain specialized environments still require surface nitriding treatment. Considering the complex heat treatment process required for this material, this paper reports a detailed study of the surface performance changes of 17–7 PH steel before and after ion nitriding following aging heat treatment. The study employs rolled 17–7 PH stainless steel as the subject material. The impact of heat treatment on plasma nitriding of stainless steel is investigated by comparing and analyzing the influence of martensite content and dislocation density within the martensite of the material prior to and following heat treatment on the hardness, thickness, and corrosion resistance of the nitrided layer on the surface of the steel after nitriding. The results demonstrate that 17–7 PH stainless steel, which does not undergo heat treatment, exhibits a high internal dislocation density, a high nitriding efficiency, and consequently, a high surface hardness. Following the application of a heat treatment, there is an increase in the martensite content of 17–7 PH stainless steel, a decrease in the dislocation content, and an increase in the matrix hardness.

DETERMINING THE PERFORMANCE OF A HEAT EXCHANGER USED IN THE FOOD INDUSTRY

The study of heat transfer in the food industry is as important as in any other industry. Food products are constantly subjected to heat treatments. For this reason, a sunflower food oil, which undergoes heat treatment in the manufacturing process, was chosen for this study. The study was carried out on a laboratory plant and aimed to determine the heat transfer coefficients for three sets of determinations: partial heat transfer coefficient inside - where the warm sunflower oil circulates, partial heat transfer coefficient in the annular space - where cold water circulates and overall heat transfer coefficient, in a tube-in-tube heat exchanger made of copper. The obtained values of heat transfer coefficients were compared with literature data for the same type of food oil. This type of heat exchanger, tube-in-tube, is specific to the food industry. Countercurrent circulation of flows through the appliance was established from the outset, as this type of circulation is preferred from the point of view of determining the performance of heat exchange appliances. Efficiency values were also established for the three sets of experimental determinations. For the calculations, the values for the temperatures of the fluids, both at the inlet and outlet of the apparatus and the values for the volume flow rates of the fluids were required.

Design of Experiment Is All You Need: Utilizing AI for High-Entropy Alloy Water Splitting Catalyst

High-entropy alloy (HEA) is a new group of material that have excited both fields of electrochemistry and computational chemistry, based on its intriguing concept and outstanding catalytic activity. Nevertheless, there exists a clear limitation to the 'trial-and-error' based research: its compositional space is too large. Therefore, AI-based high-throughput research is considered as an efficient way to optimize the composition of HEA electrocatalysts. To fully utilize AI's potential, the quality of data and rational Design of Experiment (DoE) is of importance. In this regard, we have 1) developed an automated one-step synthesis method of HEA with liquid handler and 2) made machine learning model with Gaussian process (GP) regression to minimize the overpotential (fig. 1a).DoE helps developing a new experiment by categorizing the variables and steps that are necessary. First step of DoE is to start with listing the variables. For the one-step synthesis of HEAs, independent variable was the composition of each elements, where the control variables were:A. Solvent (Amine/ethanol)B. Addition of CNT (O/X)C. Reaction temperature (high/low)D. Reaction time (long/short)E. Concentration of solution (5 mM / 10 mM)Each of control variables have two options and the selection is represented by writing an alphabet. For example, if amine (A) and high reaction temperature (C) condition was selected while the second option is used for the rest, it is written as AC. Based on confounding method theory, by conducting AC experiment, we also get information about BDE experiment by assuming a negative correlation to each other. It is written as: AC = -BDE. Similarly, an equivalent combinatorial list can be made for every possible combination (=25) , while the number of experiment is reduced from 32 to 16. Among these combinations, ABCE was found to be optimal synthesis condition (fig.1b).Afterward, we searched the optimal composition of HEAs, starting with grid searching the six-dimensional compositional field. MnFeCoNiCuMoPdPt - octonary alloy was the targeted alloy where the compositions of noble metal were fixed. Binomial distribution design was used to make the distance between neighboring points in 6-dimension compositional space equal (fig. 1c-d). 8C3 = 56 combinations were selected and consequently, the corresponding amounts of precursor solutions were transferred to 56 heat-inert vials and underwent heat treatment of 200 °C. Overpotential of 56 samples were measured and simple GP regression model was constructed based on these datasets.GP regression is composed of two parts: exploration and exploitation. During exploration, the optimal combination is recommended by searching the point that has the largest deviation. Interestingly, by comparing the Shapley Additive explanations (SHAP) value of each elements, it is clearly proved that Cu was harmful and Ni was beneficial to water splitting performance. Thus, Cu was screened out during the end of the exploration step. After finishing exploration, the next combination was recommended by searching near the point with least overpotential (exploitation step). By using GP regression, the optimal composition among HEAs was discovered in less than 200 experiments. It showed the overpotential less than 30mV for HER and less than 250mV for OER, making the overall water-splitting potential less than 1.5 V. In summary, a GP regression model showed synergistic effect with DoE, and HEA with the optimal composition showed an outstanding water splitting performance, reducing overall overpotential by 50% compared to the first step. Figure 1

Effects of spraying parameters and heat treatment temperature on microstructure and properties of single-pass and single-layer cold-sprayed Cu coatings on Al alloy substrate

Exploring the deposition of single-pass and single-layer pure Cu coatings on Al alloy substrate through high-pressure cold spray technology is a crucial endeavor with significant implications for advancing the utilization of such coatings. Regrettably, research in this specific area remains scarce, highlighting the need for further investigation and understanding. This study examined the characteristics of cold-sprayed Cu coatings deposited on a 6061 T6 aluminum alloy substrate under varying gas temperatures and pressures, and explored the effects of subsequent heat treatment on the microstructure and mechanical properties of the Cu coatings. The morphology, phase composition, surface roughness, thickness, porosity, microstructure, shear strength, and microhardness of the cold-sprayed Cu coatings were systematically analyzed. The findings indicated that the spraying parameters had a substantial impact on the properties of the Cu coatings. Specifically, increased gas pressure led to rougher surfaces and lower porosity, whereas higher gas temperature produced smoother surfaces and also reduced porosity. At 800 °C and 4.0 MPa, the Cu coatings exhibited the lowest surface roughness, measuring 8.03 μm. Conversely, at 800 °C and 5.5 MPa, the Cu coatings demonstrated the lowest porosity, at 0.26 %. Moreover, the microstructure analysis showed evidence of dynamic recrystallization in the deposited Cu particles, contributing to enhanced mechanical properties. Following this, the influence of heat treatment on the microstructure and properties of the cold-sprayed Cu coatings was examined. The results demonstrated that annealing at different temperatures induced changes in the interfacial microstructure, with the formation of intermetallic compounds between the Cu coating and Al alloy substrate. This interdiffusion phenomenon led to improved bonding strength and mechanical properties of the Cu coatings, as evidenced by increased shear strength. After undergoing heat treatment at 400 °C, the Cu coatings exhibited the highest shear strength, measuring 49.89 MPa. However, excessive heat treatment temperatures resulted in the formation of cracks and a decrease in mechanical properties.

Effect of Heat Treatment on Chemical Plating of Ni-Cr-P on 65Mn Alloy Steel

The chemical plating of Ni-Cr-P significantly affects the improvement of the structure and characteristics of the metal surface. This study aimed to investigate the impact of various plating solution components and process parameters on the deposition rate and surface hardness of Ni-Cr-P coatings on 65Mn alloy steel. Additionally, the study examined the changes in coating properties resulting from different heat treatment temperatures. The specimens coated with Ni-Cr-P underwent heat treatment at temperatures of 180°C, 200°C, 220°C, and 240°C, respectively. The testing results indicate that the plating layer achieves its highest level of performance when subjected to a heat treatment temperature of 200°C. The heat-treated coating exhibits superior wear and corrosion resistance compared to the 65Mn steel substrate. Additionally, the coefficient of friction decreases from 0.5 to 0.4. The self-corrosion potential shifts positively from -569 mV to -389 mV, and the corrosion current decreases from 61.4 μA to 14.48 μA. Furthermore, the impedance improves from 234 Ω·cm2 to 3512 Ω·cm2.

Effect of heat treatment of expanded polystyrene concrete on its compressive strength

The purpose of this research was to identify the effect of heat treatment of heat-insulating concrete on its compressive strength. For comparison, samples of normal hardening and samples that have undergone heat treatment were used. Lightweight heat-insulating concrete based on cement, polystyrene, and industrial waste was used as the subject of the research. A steaming chamber was used for steaming concrete; tests of the mechanical strength of concrete were carried out on a hydraulic press. All tests were carried out under laboratory conditions. Studies have shown that the density of polystyrene concrete after heat treatment is 7% lower than that of polystyrene concrete hardened under normal conditions. During heat treatment, the crystal structure of the material changes, which affects its final properties. This is proved by the fact that the strength of polystyrene concrete after heat treatment is 30% higher.

Blue pigment based on Ni-doped Zn2GeO4: Addressing structure and electronic properties by combining experiment and theory

Understanding the process of color development and creating practical and efficient blue pigments is crucial in ceramics. The current work describes the synthesis and characterization of Ni2+-doped Zn2GeO4 samples with varying concentrations (x = 0, 0.01, 0.02, 0.04, 0.08 and 0.16 mol%) as an effective strategy for tailoring their structure and electronic properties. These materials were synthesized using the coprecipitation method followed by microwave-assisted hydrothermal treatment at 140 °C for 10 min, and the as-synthesized samples underwent heat treatment at 1000 °C for 2 h to establish thermal-colorimetric stability. The synergistic effect of the Ni2+ 3d orbitals generating energy levels as new trapping sites in a broad energy range above the valence band was verified using DFT calculations. The substitution of Zn2+ by Ni2+ at x = 0.01 % changes the local electronic structure, resulting in a switchable electron transfer from the [NiO4] and the neighbor [ZnO4]and [GeO4] tetrahedral clusters to shared oxygen anions, which is responsible for the observed blue color, as confirmed by colorimetric and spectroscopic analysis. This study paves the way, shedding light on the strategic design of a new class of ceramic pigments characterized by low toxicity, a vibrant blue hue, and excellent chemical/thermal durability. Furthermore, it provides a robust platform for exploring its potential application in the color-tunable Zn2GeO4-based materials.

Hydroxyapatite-magnetite nanocomposites: Synthesis and superior adsorption properties for lead ion removal, with insights into intraparticle diffusion, kinetic modeling, and phase dependency

Multifunctional superparamagnetic magnetite/hydroxyapatite (Fe3O4/Ca10(PO4)6(OH)2 or MHAp) nano-composites were synthesized via a facile two-step co-precipitation method at room temperature. These magnetic nano-composites underwent heat treatment at various temperatures ranging (400°, 600°, and 900 °C), which were subsequently utilized as nanosorbents for removing Pb2+ ions. The XRD data revealed that both the magnetite and hydroxyapatite synthesized were in a pure phase. In the Fe3O4/HAp composites, there was an augmentation in the intensity peak of hydroxyapatite observed up to 600 °C. However, at 900 °C, a calcium iron phosphate phase emerged, and magnetite (Fe3O4) transitioned into the hematite (Fe2O3) phase. Elevating the heat treatment enhanced the crystallinity of the developed Fe3O4/HAp composites while diminishing the surface area. The prepared nanocomposites exhibited high adsorption efficiency across a wide pH range, with an optimal pH of 5.5. Notably, the adsorption rate of Pb2+ reached 94 % within the first 5 min, with complete metal adsorption progressively at 60 min. The kinetic and isotherm analysis of the adsorption process revealed that pseudo-second-order model and Langmuir model agreed well with the adsorption process. Also, FAH0 demonstrated the highest adsorption capacity (263.2 mg/g) for Pb2+ ions. Furthermore, the Fe3O4/HAp composite NPs exhibited remarkable recyclability even after five cycles of reuse; retaining an efficiency of over 96 %, and allowing for easy separation without a significant loss of adsorption efficiency. The results of the current desorption study underscore the promising practical applications of these nano-composites in decontaminating aqueous media.

Unveiling the self-annealing phenomena and its effect on microstructure and texture evolution in the room temperature rolled Cu-0.13Sn-0.04Mg alloy

ABSTRACT In this study, we investigated the microstructural evolution of a Cu-0.13Sn-0.04Mg alloy that underwent heat treatment followed by room temperature rolling (RTR). Initially heat-treated specimens were rolled at room temperature (RT) with reduction ratios (RR) of 40% and 75% to perform microstructural and crystallographic textural analyses. Electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) were utilise to examine both initial and deformed microstructures. Both exhibited heterogeneous microstructural distributions. Shear bands (SBs) existed in the initial specimen and became main sites for the nucleation of new grains during heat treatment. A denser presence of SBs was noted in the RTR specimens. Remarkably, an unusual self-annealing phenomenon was observed in these specimens, culminating in the emergence of recrystallized grains at RT. A plethora of such grains was observed in the severely deformed specimens, with numerous nucleating grains appearing proximal to the SBs or deformed grain boundaries (GBs). Time dependent microstructure evolution was observed via ex-situ EBSD technique in the compressed specimens. Formation of new grains, increase in high angle grain boundaries (HAGBs), and dislocation annihilations were observed with the progress of time. The crystallographic texture evolution in the initial specimen was predominantly influenced by the S component. At lower strains, the fractions of Copper component increased, whereas at higher strains, a greater fraction of Brass and S components were induced. Following a 40% RR, a saturation in hardness value was observed, which could be potentially attributable to an accelerated rate of RT recrystallization in the case of 75% RR.

Wear Resistance Behavior of Low-, Mid-, and High-Phosphorus Electroless Ni-P Coatings Heat-Treated in the Air Environment

The high-temperature heat treatment of electroless nickel–phosphorus (Ni-P) coatings in an air environment, and its consequences have scarcely been investigated. This work investigated tribological characteristics of the high-temperature, heat-treated, electroless Ni-P coatings on steel substrates with low-, mid-, and high-phosphorus content for which the average phosphorus content was 2.4 wt.%, 7.1 wt.%, and 10.3 wt.%, respectively. X-ray fluorescence and energy dispersive spectroscopy were implemented to determine the phosphorus content of the coatings. The oxidation of Ni and the formation of the NiO layer on the coating surface was confirmed by the X-ray diffraction technique. A reciprocating sliding method on a ball-on-flat system was utilized to evaluate the coating’s friction and wear behavior. Among the coatings with varying phosphorus content, a high hardness of 1086 HV was found for high-phosphorus coating when heat-treated at 400 °C in an air environment, and that was decreased to 691 HV when heat-treated at 650 °C. The oxidation of nickel in the electroless Ni-P coating occurred when heat-treated at 400 °C in an air environment, and this phenomenon was increased more when the temperature was increased to 650 °C. The characteristics of the NiO layer that formed on the surface of the heat-treated electroless Ni-P coating were influenced by the concentration of phosphorus, which caused different colors of NiO to be seen on the Ni-P coating surface. A greenish black NiO layer on the low-phosphorus and black NiO layer on the mid- and high-phosphorus Ni-P coating was developed during heat treatment at 650 °C in an air atmosphere. The adhesion and tribological characteristics of the Ni-P coatings were affected by the NiO layer developed on the heat-treated Ni-P coating surfaces. The Ni-P coatings with mid- and high-phosphorus content showed enhanced wear-resistance characteristics when they underwent heat treatment in an air atmosphere at the high temperature of 650 °C. The wear volume obtained for as-plated mid-phosphorus and high-phosphorus Ni-P coatings was 0.111 mm3 and 0.128 mm3, respectively, and that was reduced to 0.031 mm3 and 0.051 mm3, respectively, after the high-temperature heat treatment.

Tailoring room-temperature ferroelectric, magnetic and magnetoelectric properties in La and Se co-doped BiFeO3 embedded Ti3C2Tx MXene free-standing ceramics film

The ever-growing need for advancement in data storage technology demands materials that can be controlled by as many degrees as possible. In this regard, multiferroic materials that show response both in electric and magnetic dimensions are of great interest especially when being investigated in two-dimensional materials that have their potential applications. In this study, we have incorporated Lanthanum (La) doped Bismuth Ferrite (BLFO), and La and Selenium (Se) co-doped BFO (BLFSO) with two-dimensional layered titanium carbide (Ti3C2Tx) from the class of MXene as hybrid composites. The structural, optical and morphological investigation validated the successful etching of MXene from MAX, successful hybrid formation with conserved crystal structure and new phases of titanium dioxide (TiO2) detected when the samples underwent heat treatment. This heat treatment was performed in order to enhance the multiferroic properties owing to the presence of TiO2. Our results showed that the heated BLFSO-embedded Ti3C2Tx hybrid composite showed maximum remnant polarization and higher dielectric response when measured with respect to the varying electric field and at different frequencies. The prepared samples also exhibited tunable polarization response at an applied static magnetic field, unveiling their magnetoelectric properties.

Assessment of Production and Risks of Consumption of Artisanal Refreshing Drinks (Bissap, Gnamankoudji) in Haut Sassandra (Daloa-Côte d'Ivoire)

Introduction: The production and consumption of artisanal refreshing drinks (Bissap, Gnamankoudji) in the Haut Sassandra region are anchored in local culture. These artisanal drinks are experiencing considerable growth despite their artisanal and unstable production. Objective: The objective of this study is to diagnose the production of these artisanal drinks and to assess the potential risks associated with their consumption in the Haut Sassandra region. Methodology: A cross-sectional and retrospective survey was carried out with producers to make the diagnosis and with consumers to identify some main conditions linked to the consumption of these drinks. 52 producers were investigated, and 780 consumers were submitted to a questionnaire, for a total of 832 people audited. Results: Bissap and Gnamankoudji have many similar unit operations. In addition, Bissap undergoes heat treatment. The drinks are mostly packaged in used pots. The main conditions encountered were diarrhea (8.3% and 8.7%), belly bloating (2.4% and 2.8%), fever (1.80% and 2.30%), nausea (1.80% and 1.90%), vomiting (0.90% and 1%) respectively after consumption of Gnamankoudji and Bissap. Conclusion: The study collected data on the production of artisanal drinks and the risks incurred by consumers. The consumption of these drinks represents a major risk for public health.

Experimental investigation of the cooling performance of an additively manufactured prototype for nuclear fusion energy application

Metal Additive Manufacturing (MAM) is a non-traditional technology recently introduced to manufacture multifunctional mechanical components. In fact, recent developments in Laser Powder Bed Fusion (LPBF) process have enabled the production of materials characterized by high density and high thermal conductivity properties, such as copper alloys and pure copper, making the technology attractive for thermal science. In nuclear fusion energy applications, mechanical components often encounter extremely high heat fluxes. An innovative solution using unconventional integrated cooling channels is therefore required to safely manage the components. However, the high surface roughness in 3D-printed parts represents an intrinsic limitation of the LPBF technology: the cooling channels show high-pressure drops due to the high viscous dissipation generated by the rough surface. To address this challenge, a lab-scale prototype of an e-beam extraction grid for a fusion experiment with an original integrated cooling system was designed and manufactured. Additionally, a novel heating mask was designed and manufactured to reproduce the realistic heat load distribution on the grid during the experimental tests. The prototype was built using additive manufacturing with a CuCrZr copper alloy. The grid underwent heat treatment via solution annealing and age hardening, to increase thermal conductivity from about 100 W m−1 K−1 to almost 300 W m−1 K−1. The prototype was tested at three different constant heat fluxes by varying the water flow rate while measuring the pressure and the maximum temperatures of the grid. A CFD numerical model was also calibrated to estimate the thermo-hydraulic performance of the prototype under test conditions. The experimental and numerical results are presented in terms of overall thermal performance, maximum temperature, and pressure drop.

Influence of Q&amp;P-Parameters and Al-Content on the Microstructural Evolution of Lean-Medium-Mn-Steels

Abstract This report investigates the impact of different heat treatment parameters and varying Al-contents on the microstructure of Quenching &amp; Partitioning (Q&amp;P) steels. Therefore, three lean-medium-Mn-steels with Al-contents between 0.3 and 0.9 wt-% underwent heat treatments according to Quenching &amp; Partitioning regimes. For comparison, the steels were subjected to a transformation induced plasticity (TRIP) aided-bainitic-ferrite (TBF) process. In both cases, the samples were fully austenitized at 900 °C for 120 s, using dilatometry. For the Quenching &amp; Partitioning process, the quenching temperature (TQ) ranged from 210 °C to 330 °C, while the transformation induced plasticity (TRIP) aided-bainitic-ferrite samples were cooled to 360 °C. Afterwards, the specimen were re-heated to the partitioning temperature (TP) of 400 °C and isothermally held for partitioning times (tp) of 40, 120 and 200 s. Subsequently, these steels were analyzed with regard to their phase fractions and hardness. The results indicated that in the Quenching &amp; Partitioning process, the microstructure was primarily influenced by the partitioning temperature (TQ), while partitioning times (tp) played a minor role due to the time-independent martensitic transformation during quenching. In general, rising quenching temperature (TQ) led to an increase in retained austenite (RA) fraction. In the transformation induced plasticity (TRIP) aided-bainitic-ferrite (TBF) process, a substantial influence of partitioning times (tp) was found, which can be explained by the kinetics of the isothermal bainitic transformation. Regardless of the heat treatment concept, an increasing Al-content contributed to elevated retained austenite contents.

Benchmarking L-PBF Systems for Die Production: Powder, Dimensional, Surface, Microstructural and Mechanical Characterisation

While conventional die manufacturing techniques often lead to limitations in production speed and design intricacy due to labour-intensive procedures like machining and casting, Additive Manufacturing (AM) emerges as a key player offering substantial potential for cost reduction and process improvement in mass production. This study benchmarks four leading Laser Powder Bed Fusion (L-PBF) systems for producing maraging steel (EN 1.2709) dies. Despite the shared material and technology, variations in dimensional accuracy, surface finish, and microstructure were observed among the maraging steel parts. SEM/EDS, EBSD, hardness testing, and dimensional analysis revealed system-specific performance differences. Additionally, select parts underwent heat treatment and tensile testing, demonstrating the impact of post-processing on mechanical properties. These results offer valuable guidance for industrial stakeholders considering AM, highlighting the importance of supplier selection and process optimisation for achieving consistent part quality and unlocking the full potential of AM technologies.

Occurrence and level of Listeria monocytogenes and Salmonella in sushi at retails in Greater Jakarta area, Indonesia

Sushi is ready-to-eat food consisting of cooked vinegared rice and raw fish. Since sushi does not undergo heat treatment, inadequate control in the production may lead to microbial contamination. This study aimed to determine the prevalence and level of Listeria monocytogenes and Salmonella contamination in sushi sold in Greater Jakarta (Jakarta, Bogor, Depok, Tangerang, and Bekasi) area, Indonesia using the MPN-PCR method. Samples of sushi (n = 120), consisting of nigiri (rice with raw fish on top) (n = 57) and maki (rice with raw fish inside) (n = 63), were obtained from retail outlets in Jabodetabek. The results showed that both sushi products were more frequently contaminated with L. monocytogenes (14.2%) than Salmonella (2.5%). The contamination levels for L. monocytogenes and Salmonella were 3-1100 and 3.6-11 MPN/g, respectively. The highest prevalence of L. monocytogenes was found in maki sold in supermarkets (66.7%) and nigiri in kiosks (22.2%). In addition, maki and nigiri from restaurants have the highest prevalence of Salmonella at 2.2 and 3.8%, respectively. These findings indicate that contamination of L. monocytogenes and Salmonella in sushi sold at retail in Jabodetabek may pose a health risk to consumers and more study is needed to determine the source of contamination along the processing of sushi.